On-line attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and focused-beam reflectance measurement (FBRM) were used to monitor and control anti-solvent crystallization of paracetamol from an acetone-water mixture, which was conducted isothermally in a 1-L crystallizer with a flat bottom. After analyzing the particle size distribution (PSD) and transient relative supersaturation data from constant anti-solvent addition rate experiments, a simple calculation method for the set point of anti-solvent addition rate, to maintain constant supersaturation via ATR-FTIR, was developed and implemented for feedback control of unseeded and seeded crystallization. The results of the controlled feeding rate experiments show that the particle size and PSD, as well as the total batch time, can be favorably manipulated simultaneously. © 2006 American Chemical Society ...
The amino-terminal extremity of the human immunodeficiency virus type 1 transmembrane protein (gp41) is thought to play a pivotal role in the fusion of virus membranes with the plasma membrane of the target cell and in syncytium formation. Peptides with sequences taken from the human immunodeficiency virus type 1 gp41 fusogenic (synthetic peptides SPwt and SP-2) and nonfusogenic (SP-3 and SP-4) glycoproteins adopt mainly a beta-sheet conformation in the absence of lipid, as determined by attenuated total reflection Fourier transform infrared spectroscopy, and after interaction with large unilamellar liposomes, the beta-sheet is partly converted into an alpha-helical conformation. Peptides SPwt and SP-2 but not SP-3 or SP-4 were able to promote lipid mixing as assessed by fluorescence energy transfer assay and dye leakage in a vesicle leakage assay. By using polarized attenuated total reflection Fourier transform infrared spectroscopy, SPwt and SP-2 were found to adopt an oblique orientation in ...
Superabsorbent composites based on chitosan-g-poly(acrylamide) and montorillonite (CTS-g-PAAm/MMT) were synthesized through in situ radical polymerization by grafting of crosslinked acrylamide onto chitosan backbone in presence of MMT at different contents. The formation of the grafted network was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetery (DSC). The obtained porous structure was observed by scanning electron microscope (SEM). The presence of clay and its interaction with chitosan-g-poly(acrylamide) (CTS-g-PAAm) matrix was evidenced by ATR-FTIR analysis. The morphology was investigated by both X-ray diffraction (XRD) and SEM analyses. It was suggested the formation of mostly exfoliated structures with more porous structures. Besides, the thermal stability of these composites, observed by TGA analysis, was slightly affected by the clay loading as compared to the matrix. ...
In this study, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to classify blends produced from diesel S500 and different kinds of biodiesel produced by the TDSP methodology. The different kinds of biodiesel studied in this work were produced from three raw materials: soybean oil, waste cooking oil and hydrogenated vegetable oil. Methylic and ethylic routes were employed for the production of biodiesel. HCA and PCA were performed on the data from attenuated total reflectance Fourier transform infrared spectroscopy, showing the separation of the blends into groups according to biodiesel content present in the blends and to the kind of biodiesel used to form the mixtures ...
We have used three dimensional (3D) extrusion printing to manufacture a multi-active solid dosage form or so called polypill. This contains five compartmentalised drugs with two independently controlled and well-defined release profiles. This polypill demonstrates that complex medication regimes can be combined in a single personalised tablet. This could potentially improve adherence for those patients currently taking many separate tablets and also allow ready tailoring of a particular drug combination/drug release for the needs of an individual. The polypill here represents a cardiovascular treatment regime with the incorporation of an immediate release compartment with aspirin and hydrochlorothiazide and three sustained release compartments containing pravastatin, atenolol, and ramipril. X-ray powder diffraction (XRPD) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) were used to assess drug-excipient interaction. The printed polypills were evaluated for ...
TY - JOUR. T1 - Influence of hydrolytic degradation on the surface properties of poly-5d/95l-lactide resorbable bone plates. AU - Hu, Hsin Tai. AU - Shin, Tsai Chin. AU - Lee, Sheng Yang. AU - Chen, Chien Chung. AU - Yang, Jen Chang. PY - 2011/8. Y1 - 2011/8. N2 - This study explores in vitro aging effects on the surface properties of resorbable PLA95 (poly-5d/95l-lactide) bone plates. The in vitro degradation of injection molded PLA95 bone plates was undertaken by soaking them in a PBS solution. Specimens were harvested at 0, 4, 6, 8, 12, 20, and 26 weeks. After each in vitro aging period, the surface morphology, viscosity, chemical structure, wettability, and thermal properties of the PLA95 bone plates were examined by scanning electron microscopy (SEM), capillary viscometers, attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), contact angle, and modulated differential scanning calorimetry (MDSC), respectively. The surface morphology of aged PLA95 bone plates ...
in Journal of Protein Chemistry (1994), 13(1), 77-88. Peptides corresponding to lipid binding domains of Apo B-100 were synthesized, purified, and incubated with dimyristoylphosphatidylcholine (DMPC) liposomes. The secondary structure of the apo B-100 ... [more ▼]. Peptides corresponding to lipid binding domains of Apo B-100 were synthesized, purified, and incubated with dimyristoylphosphatidylcholine (DMPC) liposomes. The secondary structure of the apo B-100 peptide-lipid complexes was evaluated by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Those peptides belonging to the hydrophobic core domain of apo B-100 when associated with phospholipids were rich in beta sheet structure; a predominant alpha helical conformation was shown to be associated with one peptide located in a surface region of apo B-100. IR dichroic spectra revealed, in the case of the core peptides, that the beta sheet component is the only oriented structure with respect to the ...
Previous studies revealed that pesticides interact with α-synuclein and accelerate the rate of fibrillation. These results are consistent with the prevailing hypothesis that the direct interaction of α-synuclein with pesticides is one of many suspected factors leading to α-synuclein fibrillation and ultimately to Parkinsons disease. In this study, the biophysical properties and fibrillation kinetics of α-synuclein in the presence of rotenone were investigated and, more specifically, the effects of rotenone on the early-stage misfolded forms of α-synuclein were considered. The thioflavine T (ThT) fluorescence assay studies provide evidence that early-phase misfolded α-synuclein forms are affected by rotenone and that the fibrillation process is accelerated. Further characterization by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) shows that rotenone increases the amount of ordered secondary structure in this intrinsically disordered protein. Morphological
TY - JOUR. T1 - Salivary molecular spectroscopy. T2 - a sustainable, rapid and non-invasive monitoring tool for diabetes mellitus during insulin treatment. AU - Caixeta, Douglas C.. AU - Aguiar, Emília M. G.. AU - Cardoso-Sousa, Léia. AU - Coelho, Líris M. D.. AU - Oliveira, Stephanie W.. AU - Espindola, Foued S.. AU - Raniero, Leandro. AU - Crosara, Karla T. B.. AU - Baker, Matthew J.. AU - Siqueira, Walter L.. AU - Sabino-Silva, Robinson. PY - 2020/3/17. Y1 - 2020/3/17. N2 - Monitoring of blood glucose is an invasive, painful and costly practice in diabetes. Consequently, the search for a more cost-effective (reagent-free), non-invasive and specific diabetes monitoring method is of great interest. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been used in diagnosis of several diseases, however, applications in the monitoring of diabetic treatment are just beginning to emerge. Here, we used ATR-FTIR spectroscopy to evaluate saliva of non-diabetic (ND), ...
Cellulose nanocrystals (CNC) were successfully obtained and modified with 1,6-hexamethylene diisocyanate (HE)!) by means of in situ polymerization varying the CNC/HDI molar ratio to evaluate the number of anchored chains to the CNC. The modification was examined by elemental analysis, nuclear magnetic resonance ((13)C NMR) and attenuated total reflection Fourier transform infrared spectroscopy (IR-ATR). Nanocomposites containing 1.5 wt% CNC, modified and unmodified, were prepared by solvent casting. Thermal and mechanical properties of the resulting films were evaluated from the viewpoint of polyurethane microphase separated structure, soft and hard domains. CNC were effectively dispersed in the polyurethane matrix and depending on surface chemistry, the nanoreinforcement interacts selectively with matrix nanodomains. This interpretation is supported by differences in thermal and mechanical properties of the nanocomposites and also confirmed by AFM images. Isocyanate rich cellulose nanocrystals ...
On the molecular level, injectable fillers are designed to last different lengths of time, and can be categorized as short (0-3 months), medium (3-12 months), or long-term (12 months to indefinitely) [3]. Collagen, hyaluronic acid, and silicone are examples of commonly used short, medium, and long-term fillers, respectively. Generally speaking, shorter-term products have greater biocompatibility [4]. Depending on the type of filler used, complication rates range from 3 % to 52 % [5]. In the short term, adverse events can include bleeding, infections, edema, and migration. In the long term, there is a risk of lump formation, granulomas, abscesses, more diffuse edema, and skin discoloration [2]. In these cases, having a reliable way to identify unknown substances prior to surgical treatment would be of great value both medically and legally [6]. Attenuated total reflectance/Fourier transform infrared spectroscopy can accurately identify unknown injectable fillers [6]. However, this method requires ...
Long-term occupational exposure to low level of fluoride can induce oxidative stress and apoptosis in many cells, including lymphocyte. However, the underlying mechanism remains unclear. Hence, this study was designed to explore the potential oxidative stress and apoptosis of long-term occupational exposure to low level of fluoride in aluminum smelter workers. A total of 120 aluminum smelter workers were recruited in control, low-, middle-, and high-fluoride exposure groups with 30 workers for each group. The peripheral blood samples were collected, centrifuged, and isolated to obtain serum and lymphocyte suspensions. The air and serum fluoride concentrations were detected by fluoride ion-selective electrode method. The lymphocytic apoptosis rate, DNA damage, oxidative stress, and mRNA levels of p53, Bcl-2, and Bax were assessed by Annexin V/PI staining, comet assay, attenuated total reflectance Fourier transform infrared spectroscopy and real-time polymerase chain reaction, respectively. ...
The relationship between cellular adhesion and surface roughness for polyurethane modified by microwave plasma radiation Saeed Heidari Keshel1, S Neda Kh Azhdadi2, Azadeh Asefnezhad2, Mohammad Sadraeian3, Mohamad Montazeri4, Esmaeil Biazar51Stem Cell Preparation Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch - Islamic Azad University; 3Young Researchers Club, Islamic Azad University, North Tehran Branch, Tehran; 4Faculty of Medical Sciences, Babol University of Medical Sciences, Babol; 5Department of Chemistry, Islamic Azad University, Tonekabon, IranAbstract: Surface modification of medical polymers is carried out to improve biocompatibility. In this study, conventional polyurethane was exposed to microwave plasma treatment with oxygen and argon gases for 30 seconds and 60 seconds. Attenuated total reflection Fourier transform infrared spectra investigations of
LmrP is an electrogenic H(+)/drug antiporter that extrudes a broad spectrum of antibiotics. Five carboxylic residues are implicated in drug binding (Asp142 and Glu327) and proton motive force-mediated restructuring (Asp68, Asp128 and Asp235). ATR-FTIR (Attenuated Total Reflection - Fourier Transform Infrared) and tryptophan quenching experiments revealed that phosphatidylethanolamine (PE) is required to generate the structural intermediates induced by ionization of carboxylic residues. Surprisingly, no ionization-induced conformational changes were detectable in the absence of PE, suggesting either that carboxylic acid residues do not ionize or that ionization does not lead to any conformational change. The mean pKa of carboxylic residues evaluated by ATR-FTIR spectroscopy was 6.5 for LmrP reconstituted in PE liposomes, whereas the pKa calculated in the absence of PE was 4.6. Considering that 16 of the 19 carboxylic residues are located in the extramembrane loops, the pKa values obtained in the ...
Abstract This paper proposes a direct and efficient method to discriminate between counterfeit and authentic Cialis and Viagra samples by combining attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy with multivariate techniques. The chemical profile of 53 commercial samples (Viagra®, Cialis®) and 104 counterfeit samples (Viagra and Cialis) from distinct seizures were obtained from ATR-FTIR…. [...] ...
The competitive adsorption at the water-goethite interface between phosphate and a carboxylic acid, either oxalate, citrate, 1,2,3,4-butanetetracarboxylic acid (BTCA), mellitate or Suwannee River Standard Fulvic Acid 1S101F (FA), was investigated over a wide pH range (3-9) by means of batch experiments and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The quantitative results from the competitive adsorption measurements show that the efficiency of the organic acids in competing with phosphate was in the order oxalate , citrate , BTCA FA , mellitate. Oxalate showed no detectable effect, whereas the effect in the mellitate system was strong, and the aggregative results indicate that an increasing number of carboxylic groups favours competitive ability towards phosphate. The infrared spectroscopic results show conclusively that competition for goethite surface sites between carboxylic acids and phosphate is not a ligand-exchange reaction between inner-sphere ...
TY - JOUR. T1 - The rapid diagnosis of gliomas via serum spectroscopy. AU - Baker, Matthew. PY - 2014/3. Y1 - 2014/3. N2 - Gliomas are the most frequent primary brain tumours in adults, with these intracranial neoplasms accounting for 70% of adult malignant brain tumours (1). Confirmatory diagnosis occurs by staining tumour sections and identifying microscopic features characteristic of a disease state. The current methodology is subjective, and may require the patient to undergo unnecessary surgery. Spectroscopy is the study of the absorption and emission of light. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy is rapid, cost-effective and analytical techniques and require little or no sample preparation or use of chemicals.. AB - Gliomas are the most frequent primary brain tumours in adults, with these intracranial neoplasms accounting for 70% of adult malignant brain tumours (1). Confirmatory diagnosis occurs by staining tumour sections and identifying ...
Iron, an essential nutrient, is primarily present in soils in the form of iron-bearing minerals characterized with low solubilities. Under iron deficient conditions, some plants and microorganisms exude a mixture of iron-complexing agents, including carboxylates and siderophores, that can cause minerals to dissolve and increase iron solubility. Siderophores are chelating agents with functional groups such as hydroxamate, catecholate, or α-hydroxycarboxylate, that have high selectivity and specificity for Fe(III). This thesis is focused on adsorption/dissolution processes at the surface of a common soil mineral, goethite(α-FeOOH), in the presence of oxalate and a trihydroxamate siderophore, desferrioxamine-B (DFOB) at pH 4 and/or 6 in the absence of visible light. In order to characterize these processes at a molecular level and to understand the reaction mechanisms, a combination of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, extended X-ray absorption fine ...
Alexandra Aloia, Peter Rampson, and Rosemarie C. Chinni, Elemental Analysis of Oil Paints Using Laser Induced Breakdown Spectroscopy (LIBS), Middle Atlantic Regional Meeting of the American Chemical Society (MARM), Forensic Chemistry Session, Hershey, PA, June 2017.*. Rosemarie C. Chinni, Incorporation of Laser Induced Breakdown Spectroscopy (LIBS) Into Analytical Chemistry/Instrumental Analysis and an Innovative Lab Experience For Students, Middle Atlantic Regional Meeting of the American Chemical Society (MARM), Innovations in Analytical Chemistry Education Session, Hershey, PA, June 2017.. Ian Evans and Rosemarie C. Chinni, Determination of Impurities in Over-the-Counter Pain Relievers with Common Illicit Drug Cutting Compounds Using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectroscopy, HECBC, Penn State Berks University, Reading, PA, April 2017.*. Daniel Martin and Rosemarie C. Chinni, Using High Pressure Liquid Chromatography (HPLC) For the Analysis of ...
Primary Syrian hamster embryo (SHE) cells might be used to assess morphological transformation following treatment with chemical carcinogens. We employed attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy to interrogate SHE colonies, as complex biomolecules absorb in the mid-infrared (IR; λ = 2-20 μm) giving vibrational spectra associated with structure and function. Early-passage SHE cells were cultured (pH 6.7) in the presence or absence of benzo[a]pyrene (B[a]P; 5.0 μg/ml). Unstained colonies were applied to an ATR crystal, and vibrational spectra were obtained in the ATR mode using a Bruker Vector 22 FTIR spectrometer with Helios ATR attachment. These were individually baseline-corrected and normalised. Spectra were then analysed using principal component analysis (PCA) plus linear discriminant analysis (LDA). PCA was used to reduce the dataset dimensions before LDA was employed to reveal clustering. This determined whether wavenumber-absorbance relationships ...
The thermodynamically stable Form II of the antidiabetic drug tolbutamide exhibits a thin fiber needle shape which renders it intractable for isolation and downstream processing. This work implements two in situ process analytical technology (PAT) methods, namely, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) with orthogonal partial least-squares- principal component analysis (OPLS-PCA) for monitoring solute concentration, and Raman spectroscopy with dynamic PCA based multivariate statistical process monitoring (MSPM) for detection of solid form purity, to derive the robust design space for cooling crystallization of the desired Form IL. © 2011 American Chemical Society ...
A simple concept is proposed to metallise polyamide 66 (PA66) spherulite structures with in situ synthesised gold nanoparticles (Au NPs) using a wet chemical method. This cost-effective approach, applied to produce a PA66/Au NP hybrid material, offers the advantages of controlling the nanoparticle size, the size distribution and the organic-inorganic interactions. These are the key factors that have to be controlled to construct consistent Au nanostructures which are essential for producing the catalytic activities of interest. The hybrid materials obtained are characterised by means of scanning electron microscopy, transmission electron microscopy, attenuated total reflection-Fourier transform infrared spectrometry and X-ray diffraction spectrometry. The results show that PA66 microspheres obtained via the crystallisation process are coated with Au NPs of 13 nm in size. It was found that controlling the metal coordination is the key parameter to template the Au NPs on the spherulite surfaces. The
High performance liquid chromatography (HPLC) coupled with a Fraction Collector was employed to isolate Maillard reaction products (MRPs) formed in model systems comprising of asparagine and monosaccharides in the 60-180°C range. The primary MRP which is detected at 60°C is important for Acrylamide content and color/aroma development in foods and also in the field of food biotechnology for controlling the extent of the Maillard reaction with temperature. The discrete fractions of the reaction products were reacted with Hemoglobin (Hb) and Myoglobin (Mb) at physiological conditions and the reaction adducts were monitored by UV-vis and Attenuated Total Reflection-Fourier transform infrared (FTIR) spectrophotometry ...
TY - JOUR. T1 - Application of infrared attenuated total reflection spectroscopy to in situ analysis of atheromatous plaques in aorta. AU - Nakamura, Atsushi. AU - Koga, Takehiro. AU - Fujimaki, Makoto. AU - Ohki, Yoshimichi. AU - Sota, Takayuki. AU - Lipinska-Kalita, Kristina. AU - Nagae, Tsuneyuki. AU - Ishimaru, Shin. AU - Aizawa, Katsuo. PY - 2000. Y1 - 2000. N2 - Ex vivo infrared attenuated total reflection (ATR) spectroscopic studies have been carried out to observe the accumulation of cholesterol ester in atheromatous plaques. It has been found that ATR spectra can be successfully obtained from the intima side of aorta and give the same information as the transmission spectra. This means, the ATR spectra include information about the chemical composition of atheromatous plaques together with the degree of eventual lesions. We have demonstrated that ATR microspectroscopic measurements can give images of atheromatous plaques distribution and enable in situ observation of the relative amount ...
The Danish sculptor Anne Marie Carl-Nielsen (1863-1945) often prepared three-dimensional models in wax before producing her works of art. The Carl Nielsen Museum in Odense keeps a unique collection of around 200 of the artists fragile wax models. In 2008 the entire collection was examined, documented, X-ray radiographed, photographed, and conserved. Analyses of five figurines by attenuated total reflectance-Fourier transform infrared spectroscopy, optical microscopy, and scanning electron microscopy-energy dispersive X-ray spectroscopy showed two different kinds of wax mixtures, one containing beeswax and potato or maize starch as filler, and the other consisting of gypsum, zinc stearate, and a greasy substance. During the examination a specific deterioration phenomenon was noticed in the areas where the wax models had been strengthened with internal metal armatures. A chemical reaction between the wax mixture and the copper containing armature has caused an intense greenish colouring of the ...
Time-resolved Fourier transform infrared (TRFTIR) emission spectroscopy has been used to study the 193 nm photolysis of vinyl bromide (C(2)H(3)Br) and vinyl chloride (C(2)H(3)Cl). Time-resolved IR emission was analysed to obtain nascent vibrational state populations of two primary photolysis
Despite numerous advances in omics research, early detection of ovarian cancer still remains a challenge. The aim of this study was to determine whether attenuated total reflection Fourier-transform infrared (ATR-FTIR) or Raman spectroscopy could characterise alterations in the biomolecular signatures of human blood plasma/serum obtained from ovarian cancer patients compared to non-cancer controls. Blood samples isolated from ovarian cancer patients (n = 30) and healthy controls (n = 30) were analysed using ATR-FTIR spectroscopy. For comparison, a smaller cohort of samples (n = 8) were analysed using an InVia Renishaw Raman spectrometer. Resultant spectra were pre-processed prior to being inputted into principal component analysis (PCA) and linear discriminant analysis (LDA). Statistically significant differences (P , 0.001) were observed between spectra of ovarian cancer versus control subjects for both biospectroscopy methods. Using a support vector machine classifier for Raman spectra of ...
Successful long term bone replacement and repair remain a challenge today. Nanotechnology has makes it possible to alter materials characteristics and therefore possibly improve on the material itself. In this study, biphasic (hydroxyapatite/β-tricalcium phosphate (HA/β-TCP)) nanobioceramic scaffolds were prepared by the electrospinning technique in order to mimic the extracellular matrix (ECM). Scaffolds were characterised by scanning electron microscopy (SEM) and Attentuated Total Reflectance Fourier Transform Infrared (ATRFTIR). Osteoblasts as well as monocytes that were differentiated into osteoclast-like cells, were cultured separately on the biphasic bioceramic scaffolds for up to 6 days and the proliferation, adhesion and cellular response were determined using lactate dehydrogenase (LDH) cytotoxicity assay, nucleus and cytoskeleton dynamics, analysis of the cell cycle progression, measurement of the mitochondrial membrane potential and the detection of phosphatidylserine expression. ...
Toxic responses to contaminants following exposure concentrations typically used in laboratory tests may not reflect how biological systems respond to lower environmental levels from which hormetic effect mechanisms have been suggested. We investigated the pattern of dose-response in mammalian cells to various environmental contaminants using a range of concentrations that span those that are environmentally relevant (10(-12) M to 10(-3) M). MCF-7 cell cultures were treated for 24 h with benzo[a]pyrene (B[a]P), lindane (gamma-hexachlorocyclohexane), or polybrominated diphenyl ethers (PBDEs) congeners (47, 153, 183, and 209), then fixed in ethanol and interrogated using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. Mode of action was further studied by examining if test agents stimulated cell growth or altered CYP1A1 expression. Bimodal dose response curves were observed when MCF-7 cells were treated with PBDEs or lindane. The first peak distribution was ...
The Fourier Transform Infrared Spectroscopy facility at the CEA Paris-Saclay is located at the Laboratory of Fundamental Mechanisms in Bioenergetics (UMR 9198). It provides the users with advanced FTIR spectrometry and responds to most of the needs of FTIR analyses.. The FTIR platform includes 4 spectrometers with many accessories: Transmission cell, ATR accessories, thermostatable liquid cells, cryostat for low temperature studies … It enables the analysis of various samples under different physical forms (see below). The laboratory has a specialization in FTIR difference spectroscopy, time-resolved FTIR, low temperature FTIR, and an expertise in the investigation of biochemical reactions and photo-induced reactions.. Equipment:. - Bruker Vertex 80V (under vacuum - to reduce noise and water vapor contamination; cryostat option; detectors: Bolometer, DTGS, MCT; spectral range between 100 and 6000 cm-1). It is interfaced with a pulsed laser Continuum Surelite+OPO (tunable between 440 and 670 ...
Graphene-based materials have been studied in a wide range of applications including catalysis due to the outstanding electronic, thermal, and mechanical properties. The unprecedented features of graphene-based catalysts, which are believed to be responsible for their superior performance, have been characterized by many techniques. In this article, we comprehensively summarized the characterization methods covering bulk and surface structure analysis, chemisorption ability determination, and reaction mechanism investigation. We reviewed the advantages/disadvantages of different techniques including Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS), X-Ray diffraction (XRD), X-ray absorption near edge structure (XANES) and X-ray absorption fine structure (XAFS), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high
Cervical cancer remains a major cause of morbidity and mortality among women, especially in the developing world. Increased synthesis of proteins, lipids and nucleic acids is a pre-condition for the rapid proliferation of cancer cells. We show that scanning near-field optical microscopy, in combination with an infrared free electron laser (SNOM-IR-FEL), is able to distinguish between normal and squamous low-grade and high-grade dyskaryosis, and between normal and mixed squamous/glandular pre-invasive and adenocarcinoma cervical lesions, at designated wavelengths associated with DNA, Amide I/II and lipids. These findings evidence the promise of the SNOM-IR-FEL technique in obtaining chemical information relevant to the detection of cervical cell abnormalities and cancer diagnosis at spatial resolutions below the diffraction limit (?0.2 \ensuremathμm). We compare these results with analyses following attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy; although this ...
Chemical contaminants, such as benzoapyrene (BaP), may modulate transcriptional responses in cells via the activation of aryl hydrocarbon receptor (AhR) or through responses to DNA damage following adduct formation. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy can be employed in a non-destructive fashion to interrogate the biochemical signature of cells via generation of infrared (IR) spectra. By applying to generated spectral datasets subsequent computational approaches such as principal component analysis plus linear discriminant analysis (PCA-LDA), derived data reduction is achieved to facilitate the visualization of wavenumber-related alterations in target cells. Discriminating spectral variables might be associated with lipid or glycogen content, conformational protein changes and phosphorylation, and structural alterations in DNA/RNA. Using this approach, we investigated the dose-related effects of BaP in MCF-7 cells concentrated in S- or ...
This article presents a novel route for crosslinking a polysaccharide and polysaccharide/protein shell coated on magnetic nanoparticles (MNPs) surface via condensation reaction with squaric acid (SqA). The syntheses of four new types of collagen-, chitosan-, and chitosan-collagen coated magnetic nanoparticles as supports for enzyme immobilization have been done. Structure and morphology of prepared new materials were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR), XRD, and TEM analysis. Next, the immobilization of lipase from Candida rugosa was performed on the nanoparticles surface via N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC)/N-hydroxy-succinimide (NHS) mechanism. The best results of lipase activity recovery and specific activities were observed for nanoparticles with polymer shell crosslinked via a novel procedure with squaric acid. The specific activity for lipase immobilized on materials crosslinked with SqA (52 U/mg lipase) was about
A Fourier transform infrared spectrometer equipped with a cylindrical internal reflection element was used to sample the solidâ€liquid interface of a metallic copper film submerged in an aqueous acidic polysaccharide solution. The presence of a polysaccharide absorption band at 1050 cmâˆ1 in a water-subtracted spectrum supported previous spectroscopic data indicating polymer accumulation at the surface of the film. Firm binding of the polysaccharide to the surface after a 17-day exposure period was demonstrated by the retention of the 1050-cmâˆ1 absorption band in spectra obtained after gentle rinsing of the film surface with polymer-free water. The sampling technique also provided evidence which suggests that acidic polysaccharides, including the firmly bound exopolymers produced by adherent cells of a freshwater sediment bacterium, promoted deterioration of the copper film. Internal reflection Fourier transform infrared spectroscopy appeared to be a useful, nondestructive method to ...
Oestrogen is essential for the normal functioning of the male and female reproductive systems. Increased oestrogenic activity, commonly due to obesity, is an important cause of pathology in oestrogen-sensitive tissues. Two approaches have been used, firstly, real-time polymerase chain reaction (RT-PCR) with immunohistochemistry and secondly, attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy ...
The intercalation of organic compounds and polymers into common minerals and the chemical analysis of the resulting composite can easily be performed by students in a variety of laboratory courses including materials chemistry, inorganic chemistry, physical chemistry, and instrumental analysis. This exercise introduces students to minerals and their structural framework as well as the utility of these materials to act as effective templates for chemistry. The intercalation of these compounds can serve as models for the preparation of nanocomposite materials where the mineral acts as host to the organic substrate. In this experiment, bentonite (BENT) and kaolinite (KAO) were intercalated with dimethylsulfoxide (DMSO) and poly(ethylene glycol) (PEG-5000). Analyses were performed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS). These analyses are used to verify intercalation and determine the ...
We report on the solar-light-mediated degradation of trimethyl phosphate (TMP) and triethyl phosphate (TEP) on hematite and goethite nanoparticles in synthetic air. Adsorption and photoreactions of TMP and TEP were studied by in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) on dry and water-precovered nanoparticles in dark and under simulated solar light irradiation. Two-dimensional correlation analysis of infrared spectra was used to identify surface products as a function of reaction time. The optical properties of the hematite and goethite nanoparticles were investigated with optical spectrophotometry. The optical band gap was determined by analysis of the Tauc relationship around the band gap energy, E-g, yielding band gap energies of 2.14 and 2.28 eV for hematite and goethite nanoparticles, respectively. It is found that both TMP and TEP are readily photodegraded upon solar light irradiation (employing AM1.5 filters with 1735 W m(-2)), yielding surface ...
Fourier transform infrared (FT-IR) spectra have been measured for defatted bovine serum albumin (BSA) in D,sub,2,/sub,O with a concentration of 2.0 wt % over a temperature range of 26-90 °C and the corresponding difference spectra have been calculated by subtracting the contribution of D,sub,2,/sub,O at the same temperature. Evolving factor analysis (EFA) by selecting two factors and three factors has been employed to analyze the temperature-dependent difference IR spectra in the 1700-1600 cm,sup,-1,/sup, spectral region of the defatted BSA in D,sub,2,/sub,O solution. Three-factor EFA has been employed to determine the distinction of the three protein species involved in the process of temperature elevation: native, transitional, and denatured protein. The temperature profiles obtained from three-factor EFA indicate that heat-induced conformational change in the secondary structures of defatted BSA in D,sub,2,/sub,O undergoes two two-state transitions, a drastic transition and a slight ...
Two types of inulins of different composition were investigated in the glassy and in the crystalline states, at relative humidities within 11 and 97%. The melting and glass transition temperatures (Tm, Tg), and their crystallinity indexes (CI) were determined by modulated differential-scanning calorimetry (MDSC) and wide-angle X-ray scattering (WAXS), respectively. In parallel assays, Fourier transform-infrared spectroscopy (FTIR) coupled to principal component analysis (PCA) enabled a physical-chemical and structural characterization of samples, explaining 90% of the total variance. Finally, partial least square (PLS) models were defined to determine Tg, Tm, and CI directly from the FTIR spectra, using the MDSC and WAXS results as reference methods. In all cases, the mean of predicted values fitted very well those of the reference methods (R2 > 0.961), thus supporting the use of the PLS models to investigate unknown samples. The robustness of the models underlines the usefulness of FTIR to ...
CLX (celecoxib), a selective COX-2 (cyclo-oxygenase-2) inhibitor, has numerous pleiotropic effects on the body that may be independent of its COX-2 inhibitory activity. The cancer chemopreventive ability of CLX, particularly in CRC (colorectal cancer), has been shown in epidemiological studies. Here we have, for the first time, examined the biophysical effects of CLX on the cellular membranes of COX-2 expressing (HT29) and COX-2 non-expressing (SW620) cell lines using ATR-FTIR (attenuated total reflectance-Fourier transform IR) spectroscopy and SL-ESR (spin label-ESR) spectroscopy. Our results show that CLX treatment decreased lipid fluidity in the cancer cell lines irrespective of COX-2 expression status. As metastatic cells have higher membrane fluidity, we examined the effect of CLX on the metastatic potential of these cells. The CLX treatment efficiently decreased the proliferation, anchorage-independent growth, ability to close a scratch wound and migration and invasion of the CRC cell ...
The coking process produces great volumes of wastewater contaminated with pollutants such as cyanides, sulfides and phenolics. Chemical and physical remediation of this wastewater removes the majority of these pollutants; however, these processes do not remove phenol and thiocyanate. The removal of these compounds has been effected during bioremediation with activated sludge containing a complex microbial community. In this investigation we acquired activated sludge from an industrial bioreactor capable of degrading phenol. The sludge was incubated in our laboratory and monitored for its ability to degrade phenol over a 48 h period. Multiple samples were taken across the time-course and analysed by Fourier transform infrared (FT-IR) spectroscopy. FT-IR was used as a whole-organism fingerprinting approach to monitor biochemical changes in the bacterial cells during the degradation of phenol. We also investigated the ability of the activated sludge to degrade phenol following extended periods ...
Fourier transform infrared (FT-IR) spectroscopy is a rapid, reagent-less, non-destructive, analytical technique whose continuing development is resulting in manifold applications in the biosciences....
Dr Fawzi Abou-Chahine is a Spectroscopist at Specac, where he is involved in product testing. In this webinar, he explains the theory behind FT-IR (Fourier transform infrared spectroscopy) and gives examples of its application in a variety of industries. He also covers some of the new technological developments which are modernizing the technique.
TY - JOUR. T1 - Study by Fourier Transform Infrared Spectroscopy of the Adsorption of Carbon Monoxide on a Nickel Electrode at pH 3-14. AU - Cuesta, Angel. AU - Gutierrez, Claudio. PY - 1998. Y1 - 1998. M3 - Article. VL - 14. SP - 3397. EP - 3404. JO - Langmuir. JF - Langmuir. SN - 0743-7463. ER - ...
Diffuse-reflectance IR Fourier transform (DRIFT) spectroscopy was used to study in situ, the low-temp. (T |200 Deg) methanation of CO2 over Ru on TiO2 and on Al2O3 supports. For 3.8% Ru/TiO2, the reaction exhibits an activation energy (Ea) of 19 kcal/mol, is 0.43 +- 0.05 order in H2 concn., and essentially independent of CO2 concn. At 110 Deg, 40% of the available metal sites are occupied by CO (qCO = 0.4), a known methanation intermediate. In contrast to Ru/TiO2, Ru/Al2O3, despite having the same Ea and qCO = 0.2, is 15 times less active. Batch catalyst screening expts. showed no dependence of methanation activity on adsorbed CO(COa) formation rate (as modeled by HCOOH dehydration) or on qCO. In view of this, and the fact that CO dissocn. is structure-sensitive, heterogeneity in the active sites is invoked to reconcile the data. The high Ru dispersion on TiO2 is believed to contribute to the enhanced activity over this support. Adsorbed CO2 and H2 react, possibly at the metal-support interface, to form
Tea polysaccharides have attracted scientific interest due to their antidiabetic effects, and lower quality tea leaves have more polysaccharide in their content compared to higher grade tea leaves. The aim of this study was to optimise the ultrasound-assisted extraction (UE) conditions of polysaccharides from low-grade green tea (GTPS) by Box-Behnken response surface design on the desired response (yield). The optimal extraction parameters were determined as follows: extraction temperature (80 degrees C), extraction time (60 min), ultrasound power (400 W), and liquid to solid ratio (22 ml:g). The experimental yield of GTPS (4.65 +/- 0.29%) obtained under these conditions were well agreed with the value predicted by the model. Without applying ultrasound, while the other extraction conditions were the same (CE), the extraction yield was lower (1.83 +/- 0.04%). Fourier transform-infrared spectroscopy (FT-IR) was used for the identification of functional groups present in GTPS and gel permeation ...
TY - JOUR. T1 - Fourier transform infrared microspectroscopy identifies early lineage commitment in differentiating human embryonic stem cells. AU - Heraud, Philip Robert. AU - Ng, Elizabeth Siew Sun. AU - Caine, Sally. AU - Yu, Qing Cissy. AU - Hirst, Claire Elizabeth. AU - Mayberry, Robyn Anne. AU - Bruce, Amanda Jayne. AU - Wood, Bayden Robert. AU - McNaughton, Donald. AU - Stanley, Edouard. AU - Elefanty, Andrew George. PY - 2010. Y1 - 2010. N2 - Human ESCs (hESCs) are a valuable tool for the study of early human development and represent a source of normal differentiated cells for pharmaceutical and biotechnology applications and ultimately for cell replacement therapies. For all applications, it will be necessary to develop assays to validate the efficacy of hESC differentiation. We explored the capacity for FTIR spectroscopy, a technique that rapidly characterises cellular macromolecular composition, to discriminate mesendoderm or ectoderm committed cells from undifferentiated hESCs. ...
Predicting the contents of polysaccharides and its monosugars in Dendrobium huoshanense by partial least squares regression model using attenuated total reflectance Fourier transform infrared spectroscopy
Cao J, Ng ES, McNaughton D, Stanley EG, Elefanty AG, Tobin MJ, Heraud P. Fourier transform infrared microspectroscopy reveals that tissue culture conditions affect the macromolecular phenotype of human embryonic stem cells. The Analyst 138 (14) : 4147 - 60(2013) PubMed (PDF ...
Factors limiting hydrogen sulfide production were identified in a two-species biofilm containing sulfate-reducing bacteria (Desulfovibrio desulfuricans) and nonsulfate-reducing bacteria (Pseudomonas fluorescens). Profiles of hydrogen sulfide (H2S) concentration, pH, local mass-transport coefficient, local flow velocity, and local relative effective diffusivity in the biofilm were measured using microelectrodes. Biofilms had a heterogeneous structure consisting of cell clusters separated by voids. Typically, the H2S concentration was lower in the voids than in the adjacent cell clusters, demonstrating that the voids acted as transport channels for removing H2S from cell clusters. The extent of biofilm heterogeneity was directly correlated with the flux of H2S from cell clusters. At flow velocities below 2 cm/s, the flux of H2S from cell clusters depended on the flow velocity. We concluded that at these flow velocities the H2S production rate was limited by the delivery rate of sulfate ions to the ...
TY - JOUR. T1 - Active-Site Glu165 Activation in Triosephosphate Isomerase and Its Deprotonation Kinetics. AU - Deng, Hua. AU - Dyer, R. Brian. AU - Callender, Robert. PY - 2019/5/16. Y1 - 2019/5/16. N2 - Triosephosphate isomerase (TIM) catalyzes the interconversion between dihydroxyacetone phosphate (DHAP) and d-glyceraldehyde 3-phosphate (GAP) via an enediol(ate) intermediate. The active-site residue Glu165 serves as the catalytic base during catalysis. It abstracts a proton from C1 carbon of DHAP to form the reaction intermediate and donates a proton to C2 carbon of the intermediate to form product GAP. Our difference Fourier transform infrared spectroscopy studies on the yeast TIM (YeTIM)/phosphate complex revealed a C=O stretch band at 1706 cm-1 from the protonated Glu165 carboxyl group at pH 7.5, indicating that the pKa of the catalytic base is increased by ,3.0 pH units upon phosphate binding, and that the Glu165 carboxyl environment in the complex is still hydrophilic in spite of the ...
en] The structure, composition, and physico-chemical properties of lipid-protein complexes generated between dimyristoylphosphatidylcholine (DPMC) and the CNBr fragments of human apoA-I were studied. The fragments were separated by high performance liquid chromatography and purified on a reversed-phase column. The complexes with DMPC were isolated on a Superose column; their dimensions were obtained by gradient gel electrophoresis and by electron microscopy. The secondary structure of the protein in the complexes was studied both by circular dichroism and by attenuated total reflection infrared spectroscopy. The fragments 1 and 4 of apoA-I, containing, respectively, two and three amphipathic helices, recombined with the phospholipid to generate discoidal particles with sizes similar to that of apoA-I- and apoA-II-DMPC complexes. The infrared measurements indicated that in all complexes the apolipoprotein helical segments were oriented parallel to the phospholipid acyl chains and that the protein ...
The aim of this study was to develop a thermally and operationally stable trypsin through covalent immobilization onto chitosan magnetic nanoparticles (Fe3O4 @CTS). The successful preparation of the Fe3O4 @CTS nanoparticles was verified by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM), which indicated that the prepared Fe3O4 @CTS nanoparticles have superparamagnetic properties, with an average size of approximately 17 nm. Then, trypsin was covalently immobilized onto the Fe3O4 @CTS nanoparticles at a high loading capacity (149.25 mg/g). The FTIR data demonstrated that the trypsin had undergone a conformational change compared with free trypsin, and the Michaelis constant (Km) and the maximum hydrolysis reaction rate (Vmax) showed that the trypsin immobilized on the Fe3O4 @CTS had a lower affinity for BAEE and lower activity compared with free trypsin. However, the immobilized trypsin ...
Abstract : Resorcinol is widely used in manufacturing of several drugs and pharmaceutical products that are mainly usedfor topical ailments. The main objective of this study is to use an alternative strategy i.e., biofield treatment to alterthe physical, spectral and thermal properties of resorcinol. The resorcinol sample was divided in two groups, whichserved as control and treated group. The treated group was given biofield treatment and both groups i.e., control andtreated were analysed using X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, UV-Visible (UVVis)spectroscopy, Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). The results showeda significant decrease in crystallite size of treated sample i.e., 104.7 nm as compared to control (139.6 nm). The FTIRand UV-Vis spectra of treated sample did not show any change with respect to control. Besides, thermal analysisdata showed 42% decrease in latent heat of fusion. The onset temperature of ...
Fourier-transform infrared spectroscopy has shown alterations of spectral characteristics of cells and tissues as a result of carcinogenesis. The research reported here focuses on the diagnosis of cancer in formalin-fixed biopsied tissue for which immunochemistry is not possible and when PAP-smear results are to be confirmed. The data from two groups of patients (a control group and a group of patients diagnosed with cervical cancer) were analyzed. It was found that the glucose/phosphate ratio decreases (by 23-49%) and the RNA/DNA ratio increases (by 38-150%) in carcinogenic compared with normal tissue. Fourier-transform microspectroscopy was used to examine these tissues. This type of study in larger populations may help to set standards or classes with which to use treated biopsied tissue to predict the possibility of cancer. Probabilistic neural networks and statistical tests as parts of these biopsies predict the possibility of cancer with a high degree of accuracy (,95%).. © 2005 Optical ...
A Gram-negative bacterium isolated from the sub-surface water of Ikang River, Niger Delta region, Nigeria produced an unusual biosurfactant in waste frying oil-minimal medium. Cultural and biochemical characterizations as well as 16S rRNA sequencing identified the bacterium as a strain of Pseudomonas aeruginosa with 100% sequence homology with Pseudomonas aeruginosa strain HNYM41. Biochemical characterizations, thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and Fourier transform-infrared (FT-IR) spectrometry identified the active compound as a glycolipopeptide (peptidoglycolipid) composed of 40.36% carbohydrates, 20.16% proteins and 34.56% lipids. The biosurfactant reduced surface tension of water from 72.00 to 24.62 dynes/cm at a critical micelle concentration (CMC) of 20.80 mg/L indicating excellent effectiveness and efficiency properties. Commendable oil-washing property (79.92% oil recovery) with an elution rate of 0.68 mL/min at 70°C, foaming and foam ...
Article Fourier transform infrared spectroscopic investigation of humic substance samples of different origin and typology supported by chemometric tools. In this paper 198 FTIR spectra of humic substance (HS) extracted from lake, marine sediments, s...
Nanocrystalline CoyZn1-yHozFe2-zO4 (where y = 0.0, 0.25, 0.5, 0.75, 1.00 and z=0.0, 0.03, 0.06, 0.08, 0.1) ferrites were prepared by sol-gel auto combustion method at pH of 8. Samples were obtained by annealing at relatively low temperature 600 °C for 4 h and characterized by thermo gravimetric/differential thermal analysis (TG/DTA) all the samples were annealed at 600 °C for 4 h. The prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. Particle size measured from XRD and TEM are in good agreement with each other. The TEM study reveals the fine particle nature of the ferrites with little agglomerations. The cation distribution suggests that Zn2+ ion mainly on tetrahedral-A sites, Ho3+ ions shows strong preference towards octahedral-B site, Co2+ and Fe3+ ions are randomly distributed at the tetrahedral-A and octahedral-B site. FT-IR study confirmed two main
In this work we have used Fourier transform infrared (FTIR) / vibrational absorption (VA) spectroscopy to study two cancer cell lines: the Henrietta Lacks (HeLa) human cervix carcinoma and 5637 human bladder carcinoma cell lines. Our goal is to experimentally investigate biochemical changes and differences in these cells lines utilizing FTIR spectroscopy. We have used the chemometrical and statistical method principal component analysis (PCA) to investigate the spectral differences. We have been able to identify certain bands in the spectra which are so-called biomarkers for two types of cell lines, three groups for the 5637 human bladder carcinoma cell line (5637A, 5637B and 5637C), and another one for the HeLa human cervix carcinoma cell line. The vibrational modes can be assigned to specific bands involving characteristic motions of the protein backbone. This work shows that infrared vibrational absorption (VA) spectroscopy can be used as a useful tool in medical diagnostics that provides in ...
The differentiation of roots of agricultural species is desired for a deeper understanding of the belowground root interaction which helps to understand the complex interaction in intercropping and crop-weed systems. The roots can be reliably differentiated via Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). In two replicated greenhouse experiments, six pea cultivars, five oat cultivars as well as seven maize cultivars and five barnyard grass proveniences (n = 10 plants/cultivar or provenience) were grown under controlled conditions. One root of each plant was harvested and five different root segments of each root were separated, dried and measured with FTIR-ATR spectroscopy. The results showed that, firstly, the root spectra of single pea and single oat cultivars as well as single maize and single barnyard grass cultivars/proveniences separated species-specific in cluster analyses. In the majority of cases the species separation was correct, but in a few cases, the
Attenuated total reflection (ATR) infrared absorption spectroscopy is a well-known vibrational spectroscopy technique for many different applications. In recent years this technique has been used to detect thin layer(s) lying on a solid substrate. Su
In this report, a facile, efficient and low cost electrochemical sensor based on bimetallic Au-Cu nanoparticles supported on P nanozeolite modified carbon paste electrode (Au-Cu/NPZ/CPE) was constructed and its efficiency for determination of hydrazine in trace level was studied. For this purpose, agro waste material, stem sweep ash (SSA) was employed as the starting material (silica source) for the synthesis of nano P zeolite (NPZ). After characterization of the synthesized NPZ by analytical instruments (scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy), construction of Au-Cu/NPZ/CPE was performed by three steps procedure involving preparation of nano P zeolite modified carbon paste electrode (NPZ/CPE), introducing Cu +2 ions into nano zeolite structure by ion exchange and electrochemical reduction of Cu +2 ions upon applying constant potential ...
This study was intended to isolate and investigate endophytic fungi and its metabolite as an active biocontrol agent. Endophytic fungal secondary metabolites are considered as an effective and environmentally friendly alternative to synthetic chemicals for integrated pest management. In this study, different parts of medicinal plant Plectranthus amboinicus (Oregano) were selected to isolate twenty ...
The objective of this study was to improve the dissolution rate of a poor water soluble drug, piroxicam, by solid dispersion technique. Solid dispersions were prepared by three different methods depending on the type of carrier. The dissolution rate of piroxicam was markedly increased in solid dispersion of myrj 52, Eudragit® E100 and mannitol. Solubility studies revealed a marked increase in the solubility of piroxicam with an increase in myrj 52 and Eudragit® E100 concentrations. Data from the X-ray diffraction and FT-IR spectroscopy showed that piroxicam was amorphous in the solid dispersions prepared with dextrin and Eudragit® E100.. ...
Variable selection with supervised classification is currently an important tool for discriminating biological samples. In this paper, 15 supervised classification algorithms based on a support vector machine (SVM) were applied to discriminate Cryptococcus neoformans and Cryptococcus gattii fungal species us
A lifetime of 20-30 years is generally regarded as necessary for photovoltaic modules to achieve economic break even. As a consequence, understanding how to improve the durability and reliability of the modules is becoming a necessity. Photovoltaic modules are exposed to extremely harsh conditions of heat, humidity, and ultraviolet (UV) radiation which affect the properties of the encapsulant material and cause yellowing, delamination and degradation of the material, which knock on effects on the performance and the long-term reliability of photovoltaic modules. This study addresses the impact of UV on the photochemical degradation of Ethylene-vinyl Acetate (EVA). Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance (FTIR-ATR) mode was performed on aged samples. The samples were exposed to UV light from a xenon lamp at 0.68 W/m2 at 340 nm with exposure up to 1000 hours. The FTIR-ATR measurement shows significant changes in the absorption at 1740 cm-1, 1720 cm-1 and 910 cm-1 ...
Hydroxyapatite (HA) having chemical formula Ca10(PO4)6(OH)2, is the main chemical component of human bone tissue (70%). This is the reason why it has been widely engaged in the dental and non-load bearing implantations, to cope up with the bone response as a bioactive material. In this study HA powder was synthesized by wet chemical method, using phosphoric acid (H3PO4) and eggshells. The synthesized HA powder was characterized by X-ray diffraction analysis, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform (FT-IR) spectroscopy. The Thermos gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HA powder at higher temperatures. The results of the study indicate that sintered (at 900°C) HA powder resembles the feature of pure and single apatite phase having favourable Ca/P ratio ranging from 1.7 to 2.4.
Infrared (IR) absorption spectroscopy directly probes the vibrational modes associate with the molecular bonds in a sample by measuring absorption in the mid-infrared spectral region, ~ 3 - 20 microns. IR spectroscopic measurements are thus intrinsically endowed with a level of chemical specificity and information content far exceeding that of most other optical measurement techniques.[1] Despite their potential, IR absorption measurements suffer not only from limited sensitivity, but are severely hindered by the strong, broad absorption of water that overlaps the bands of most organic compounds of interest. While recent surface enhanced infrared absorption (SEIRA) spectroscopy measurements have shown that IR resonant nanoantennas can be leveraged to dramatically increase sensitivity, [2-3] these have all been performed in dry environments and without time-resolution ...
TY - JOUR. T1 - Quantitative analysis of albumin adsorption onto uncoated and poly(ether)urethane-coated ZnSe surfaces using the attenuated total reflection FTIR technique. AU - Jeon, Joong S.. AU - Raghavan, Srini. AU - Sperline, R. P.. PY - 1994/11/17. Y1 - 1994/11/17. N2 - An attenuated total reflection (ATR) Fourier transform infrared radiation (FTIR) technique has been explored for the in situ quantitative analysis of bovine serum albumin (BSA) adsorption from aqueous solutions onto a segmented poly(ether)urethane film deposited on a ZnSe internal reflection element (IRE) and onto a bare ZnSe IRE surface. The IR spectral area of the amide II band was used for the quantitative analysis of adsorption. BSA adsorption reached equilibrium within 30 min and changed linearly with solution concentration in the range 0.5-6 wt.% and was found to be dependent on the solution pH and substrate type. At the physiological concentration, BSA adsorption densities of 2.4 mg cm-2 and 3.9 μg cm-2 were ...
Environmental protection is worldwide considered a primary issue of the sustainable development. In order to preserve our environment, a major challenge is to remedy the polluted environment by re-using wastes. In this work biowaste sourced soluble substances (CVT230) are used for the design of two types of heterogeneous photocatalysts for wastewater cleaning: an inorganic perovskite and a organic-inorganic hybrid. The materials were carefully characterized by XRD combined with Rietveld refinement, N2 adsorption, FT-IR spectroscopy, thermo gravimetric analysis, transmission electron microscopy and zeta potential analysis. Their photocatalytic activity was tested for the abatement of pollutants found in wastewaters, 4-methylphenol (4-MP), a representative phenolic compound and/or the Crystal Violet (CV), a cationic dye. The experiments were performed in aqueous solution irradiated by simulated solar light ...
The photo-oxidation of propane in dry and humid synthetic air was studied on anatase and rutile nanoparticles by operando diffuse reflectance Fourier-transform infrared (DRIFT) spectroscopy and mass spectrometry (MS). Analysis of the propane removal and CO2 production rate shows that the carbon mass balance (CMB) is CMB , 1 under all reaction conditions up to 1 h operation, and that it is significantly higher on rutile than anatase in humid reaction gas. Corresponding analysis of DRIFT spectra acquired simultaneously as the MS measurements shows that the CMB data scales with the concentration of surface species, i.e. the deviations from unity in the reactant-product mass balance (1-CMB) is quantitatively accounted for by a corresponding increase of surface species measured by DRIFT. The identity of surface species and rate determining reactions steps is deduced by fitting the mode-resolved vibrational IR bands to a kinetic model that accounts for observed temporal evolution of absorption bands. ...
Polymer thin films derived from the essential oil of Lavandula angustifolia (LA) are fabricated using plasma polymerization, and their surface and chemical characteristics investigated. The surface morphology of the polyLA films is examined using an atomic force microscope (AFM). The polymer is found to be uniform and pinhole free, and the average roughness of the films is found to be less than a nanometer and independent of the RF power employed during fabrication. Fourier transform infrared (FTIR) spectroscopy analysis of the polyLA film is performed. Comparison of the FTIR spectra for polyLA film with that of the starting monomer demonstrates that many of the original functional groups are retained during the polymerization process. Bands assigned to C==C stretching are lost due to their participation in the polymerization reactions. With increased RF power employed during fabrication, a decrease in intensity of most of the remaining bands in the FTIR spectra for the polyLA films is found. ...
The aim of the present study was to investigate the Ethanol extract leaf from Jasminum sambac Linn. Qualitative analysis of showed the presence of alkaloids, carbohydrates, flavonoids, tannins, phenol, steroids, terpenoids and glycosides. Absence of leaves extracts protein, mucilage, saponins, fats and fixed oils. This work deals with the phytochemical screening and GC-MS, FT-IR studies of the Ethanol extract. The highest peak area of (40.87%) was obtained by 7-Tetradecenal, (Z) - (C14H26O) at retention time of (18.959) and the lowest peak area of (0.16%) was obtained by Phenol, 3, 5-bis (1,1-dimethylethyl)- (C14H22O) at retention time of (12.294). The FT-IR spectroscope studies shows different characteristic peak values of many functional groups in the extract. FT-IR analysis of leaf extract confirmed the presence of amide, alcohol, phenol, alkane, carboxylic acid, aldehyde, ketone, alkene, primary amine, aromatic esters, alkyl halide, and aliphatic amine compounds. This study summarizing the ...
inproceedings{BUT97278, author=Lucie {Töröková} and František {Krčma}, title=FTIR Analysis of DC Glow Discharge in CH4-N2 Mixtures, annote=The exploration of planetary atmosphere is being advanced by the exciting results of the Cassini-Huygens mission to Saturn and Titan, its most famous moon. The complex chemistry revealed in such atmospheres leading to the synthesis of bigger molecules is providing new insights into our understanding of how life on Earth developed. In our experiments Titans atmosphere is simulated in a glow-discharge formed from a mixture of CH4-N2 gas. Samples of the discharge gas were analysed by Fourier Transform Infrared Spectroscopy. Measurements revealed HCN and NH3 to be the major products of the plasma with traces of C2H2. Carbon monoxide and water were detected as reaction products in methane-nitrogen gas mixture with 1% of carbon dioxide. These molecules could be precursors for other more complicated molecular structures, even some amino acids., ...
The effect of milling on the solid-state transitions of sulfathiazole polymorphs in the absence and presence of solvent and excipients was monitored by X-ray powder diffraction (XRPD), attenuated total reflectance infrared (ATR-IR) and near-infrared (NIR) spectroscopy. Sulfathiazole forms FII-FV undergo a transformation toward the metastable FI, which involves an intermediate amorphous stage upon milling at ambient temperature. Milling FIII with catalytic amounts of solvent converts FIII to FIV or to mixtures of FI and FIV depending on the solvent used. Pure FIV can be easily prepared from FIII by this method. The physical stability of pure sulfathiazole forms in the presence of different levels of relative humidity (RH) was also investigated. At low RH all sulfathiazole forms are stable but at RH levels above 70% FII, FIII and FIV remain stable while FI and FV transform to mixtures of FII and FIV without any apparent change in the external form of the crystals. Co-milling FIII with... ...
In order to characterize the molecular structure and organization of the lipids, we performed attenuated total reflectance infrared (ATR-IR) spectroscopy measurements. Fig. 3a shows the absorption bands characteristic for the stretching vibrations of the lipid acyl chains for the lipid monolayer (black line) and for the lipid-graphene assembly (red line).28 The presence of these peaks confirms that the lipids remain underneath the graphene. Depending on whether the lipids are in contact or not with graphene, a shift in the peaks maxima is observed, characteristic for changes in the lipid conformation.29 Additionally, a shift was observed in the asymmetric methylene vibration (CH2) from ∼2915 to 2912 cm−1 and in the symmetric methylene vibration (CH2) from ∼2848 to 2844 cm−1, respectively. Furthermore the intensity of the asymmetric and symmetric CH2 bands of the lipid-graphene assembly increased. The observed shift is attributed to a change of the physical properties of the lipids film, ...
In-office and at-home bleaching techniques are widely used methods for the whitening of teeth. However, the safety of these techniques has not been clarified yet. The aim of the current study is to investigate the in-office- and at-home-bleaching-induced structural and quantitative changes in human enamel and dentin at the molecular level, under in vitro conditions. The Fourier transform mid-infrared (mid-FT-IR) spectroscopic technique was used to monitor bleaching-induced structural changes. Band frequency and intensity values of major absorptions such as amide A, amide I, phosphate (PO(4)), and carbonate (CO(3)(-2)) bands, for treatment groups and control, were measured and compared. The results revealed that both procedures have negligible effects on dentin constituents. In office-bleached enamel, in addition to demineralization, a decrease in protein and polysaccharide concentrations, mineral-to-protein ratio, and the strength of hydrogen bonds around NH groups, as well as a change in ...
Abstract: Carbon aerogels were prepared, using a freeze-drying method, from graphene oxide (GO) and carbon nanotube (CNT) hybrid hydrogels. The resulting aerogels were characterized using scanning electron microscopy and Fourier-transformed infrared spectroscopy. The adsorption of U(VI) on the GO-CNT aerogels was studied as a function of solid dosage, pH value, initial concentration, and contact time. The results showed that GO-CNT aerogels have high uranium(VI) removal capacities, and are promising sorbents.. Key words: Graphene/carbon nanotube, Hydrogel, Aerogel, Adsorption, Uranium(VI) ...
We report the FTIR spectra of the Amide I and Amide A vibrational modes of N-methylacetamide (NMA, CH$_3$CONHCH$_3$) isolated in a solid parahydrogen (pH$_2$) matrix. NMA is one of the simplest molecules that contains the peptide bond and has therefore been the subject of numerous studies, especially those concerning peptide structure and dynamics. Solid pH$_2$ is a unique quantum solid matrix host that, among other features, allows for high-resolution IR studies of trapped dopant species. In our preliminary report, talk R008 (2006)} we showed that the Amide I lineshape was surprisingly broad and shifts were observed with small changes in temperature. That talk did not resolve the origin of these shifts with temperature that require many minutes to fully equilibrate. Further investigations have revealed that the frequency and breadth of the transition depends partially on the orthohydrogen concentration in the matrix. The Amide I lineshape displays both reversible and irreversible components ...
FTIR stands for Fourier-transform infrared spectroscopy. Fourier transform is the process of decomposing a signal into the frequencies that combine to make that signal. The process is similar to taking a musical chord and separating it into the individual notes that comprise it. In the case of FTIR, the signal that goes through the Fourier transform process is the sample being exposed to infrared light. Most molecules are infrared active, which means that they react in various ways when exposed to infrared light. FTIR systems can test samples that are in solid, gas, or liquid states.. In the case of cannabis, FTIR systems are used to find optimum ratios and schedules for lighting and watering in order to maximize potency (PDF). An FTIR system can also test strain samples in different physicals states. This allows growers to see the composition of cannabinoids and terpenes in solid and gas form. Many cannabinoids and terpenes have different decarboxylation points, which means that some methods ...
A TG/FTIR instrument that combines thermogravimetric analysis with evolved products analysis by Fourier transform infrared spectroscopy is a powerful thermo-analytical technique providing a quantitative time-resolved analysis of major pyrolysis products of any bio-originated material including tobacco. In this work, we demonstrate how the time-resolved spectra of TG/FTIR along with the target factor analysis (TFA) can be used to identify and then quantify the pyrolysis products.
The phase error caused by sampling the fringe patterns in practical Fourier transform profilometry is discussed. In the fTp method, a grating pattern is projected onto an object surface and the deformed fringe is Fourier-transformed and processed in its spatial frequency domain as well as in its space-signal domain. it has been stated that the fundamental spectrum must separate from zero and higher order spectra, because only the fundamental component is needed for phase retrieval. Here we discuss another kind of spectrum overlapping that is caused by the discrete Fourier transform (DFT). The DFT of a digitized fringe pattern results in periodically equi-spaced frequency islands in the spectrum domain. The higher order spectra from adjacent islands may overlap the fundamental spectrum that is filtered out for phase reconstruction. This kind of overlapping also introduces noise into the reconstructed phase. The conclusion is that to obtain a correct reconstruction of the measured object, the ...
A Fourier-transform infrared spectroscopic comparison of cultured human fibroblast and fibrosarcoma cells: a new method for detection of ...
Plasmonics is the modern field of physics aimed at the interaction between electromagnetic field and free electrons in a metal on metal-dielectric interfaces or in metallic nanoparticles with dielectric surrounding. Our group is oriented mainly on the fabrication of metal nanostructures and structured metal-dielectric interfaces by various methods such as electron beam lithography, focused ion beam, ion beam assisted deposition, selective deposition of metal nanoparticles etc. Moreover, we are able to measure optical properties of the fabricated structures by means of optical dark-field spectroscopy, spectroscopic ellipsometry, scanning near field optical microscopy techniques and fourier transform infrared spectroscopy. The main goal is to utilize the fabricated and characterized plasmonic structures in applications, i.e. plasmon-enhanced photoluminescence, plasmon-enhanced infrared absorption, surface enhanced infrared spectroscopy, enhanced biosensing and optical manipulation below the ...
The Spectrum Two FT-IR Analysis System offers trouble-free analysis of lubricant oil. Modern instrumentation makes it possible to obtain lab-quality results with a portable system making them well suited to on-site analysis.
A simple chemical precipitation technique is reported for the synthesis of a hybrid nanostructure of single-wall carbon nanotubes (SWCNT) and titania (TiO2) nanocrystals of average size 5 nm, which may be useful as a prominent photocatalytic material with improved functionality. The synthesized hybrid structure has been characterized by transmission electron microscopy (HRTEM), energy-dispersive X-ray analysis (EDAX), powder X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. It is clearly revealed that nearly monodispersed titania nanocrystals (anatase phase) of average size 5 nm decorate the surfaces of SWCNT bundles. The UV-vis absorption study shows a blue shift of 16 nm in the absorbance peak position of the composite material compared to the unmodified SWCNTs. The photoluminescence study shows a violet-blue emission in the range of 325-500 nm with a peak emission at 400 nm. The low temperature electrical transport property of the synthesized ...
|p> We have investigated the possibility of avoiding formation of Er-rich oxide clusters in ErAl3O6-TiO2-SiO2 glassy films. Samples containing 0.5, 1 and 3 mol% Er31 were prepared using a precursor with a single, isolated Er-ion, ErAl3(OPri)12, in the metal-organic sol-gel route. The thermal decomposition of the gel films to form amorphous oxide films was studied by thermogravimetry, Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction and by means of a transmission electron microscope, equipped with an energy dispersive spectrometer. The microscopy studies of the oxide films obtained after 2 h at 9008C showed that they were amorphous and free of Er-rich clusters. The optical and vibrational properties of the glasses were studied using FT-IR, Raman scattering and luminescence spectroscopy. The samples exhibit luminescence both in the visible and IR under excitation of the 514.5 and 488 nm Ar1 laser lines. The emission around 1.5 mm was maximum for the 1 mol% sample. The results show