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 ...
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
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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....
Fourier Transform Infrared Spectroscopy (FTIR spectroscopy) covers a wide range of chemical applications, especially for polymers and organic compounds.
The EPA and the State of California are phasing in tighter emissions requirements for hydrocarbons. Designing emissions control systems to meet these standards requires detailed information of the composition of the exhaust stream. Of particular interest is the ability to determine non-methane organic gases (NMOG) to meet reactivity index (RI) specifications.Fourier transform infrared (FT-IR) spectroscopy is a technique widely used to measure organic compounds. Many NMOG compounds have unique infrared signatures that can be speciated by FT-IR. Because FT-IR can analyze samples in real time, the effects of driving cycle events such as the cold start and acceleration modes may be studied.This paper gives a brief overview of the new regulations being phased in for hydrocarbons, as well as the techniques currently used for these measurements. FT-IR instrumentation and sampling techniques for exhaust gas analysis are explained. A discussion of the different gases which may be analyzed by FT-IR is ...
The SFB members Dr. Victor A. Lórenz-Fonfría and Prof. Joachim Heberle from project B3 have published an article and video demonstrating "Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy" (1). The video is openly accessible on the website of JoVE, the Journal of Visualized Experiments, which is is the worlds first peer reviewed scientific video journal.. In their video, Lórenz-Fonfría and Heberle demonstrate "key steps of protein function, in particular backbone conformational changes and proton transfer reactions, [which] often take place in the microsecond to millisecond time scale. These dynamical processes can be studied by time-resolved step-scan Fourier-transform infrared spectroscopy, in particular for proteins whose function is triggered by light." (1). Reference:. ...
There is no doubt that the contribution of microbially mediated bioprocesses toward maintenance of life on earth is vital. However, understanding these microbes in situ is currently a bottleneck, as most methods require culturing these microorganisms to suitable biomass levels so that their phenotype can be measured. The development of new culture-independent strategies such as stable isotope probing (SIP) coupled with molecular biology has been a breakthrough toward linking gene to function, while circumventing in vitro culturing. In this study, for the first time we have combined Raman spectroscopy and Fourier transform infrared (FT-IR) spectroscopy, as metabolic fingerprinting approaches, with SIP to demonstrate the quantitative labeling and differentiation of Escherichia coli cells. E. coli cells were grown in minimal medium with fixed final concentrations of carbon and nitrogen supply, but with different ratios and combinations of 13C/12C glucose and 15N/14N ammonium chloride, as the sole ...
In this paper, the measurement of the energy difference between the rotational conformers of 1-2-diiodotetrafluoroethane by GC/FT-IR spectroscopy is demonstrated for the first time. The Δ,i,H,/i,° obtained is lower than the value reported from the use of the neat vapor-phase method. The difference between the values may be attributed to solvent and adsorption effects.. PDF Article ...
Principal component analysis (PCA) was used to identify the main sources of variation in the Fourier transform infrared (FT-IR) spectra of 329 wines of various styles. The FT-IR spectra were gathered using a specialized WineScan instrument. The main sources of variation included the reducing sugar and alcohol content of the samples, as well as the stage of fermentation and the maturation period of the wines. The implications of the variation between the different wine styles for the design of calibration models with accurate predictive abilities were investigated using glycerol calibration in wine as a model system. PCA enabled the identification and interpretation of samples that were poorly predicted by the calibration models, as well as the detection of individual samples in the sample set that had atypical spectra (i.e., outlier samples). The Soft Independent Modeling of Class Analogy (SIMCA) approach was used to establish a model for the classification of the outlier samples. A glycerol ...
Use of Fourier-transform infrared spectroscopy to quantify immunoglobulin G concentration and an analysis of the effect of signalment on levels in canine serum
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Exploration of attenuated total reflectance mid-infrared spectroscopy and multivariate calibration to measure immunoglobulin G in human sera
A detailed study of the mechanism by which a dizinc catalyst copolymerizes cyclohexene oxide and carbon dioxide is presented. The catalyst, previously published by Williams et al. ( Angew. Chem. Int. Ed. 2009, 48, 931), shows high activity under just 1 bar pressure of CO2. This work applies in situ attenuated total reflectance infrared spectroscopy (ATR-FTIR) to study changes to the catalyst structure on reaction with cyclohexene oxide and, subsequently, with carbon dioxide. A computational investigation, using DFT with solvation corrections, is used to calculate the relative free energies for various transition states and intermediates in the cycle for alternating copolymerization catalyzed by this dinuclear complex. Two potentially competing side reactions, sequential epoxide enchainment and sequential carbon dioxide enchainment are also investigated. The two side-reactions are shown to be thermodynamically disfavored, rationalizing the high selectivity exhibited in experimental studies using ...
A hydrogen-bonded complex between an aromatic acid and an enantiopure chiral amine has been dissolved in a nematic solvent, giving rise to a cholesteric medium. Fourier transform infrared (FT-IR) experiments have been performed at various temperatures on both sides of the cholesteric-isotropic transition. Liquid crystalline order provides significant enhancement to the strength of interaction, inducing a discontinuous jump in concentration of the complex at the cholesteric-isotropic transition.
This monograph will be included in a future ACGIH® Signature Publication that will be entitled: Air Sampling Technologies: Principles and Applications. It provides general guidance for the use of direct-reading Fourier Transform Infrared (FTIR) Spectroscopy for occupational and environmental air monitoring.. Member - $ ...
in Biochimica et Biophysica Acta-Biomembranes (2008), 1778(11), 2535-43. The interactions between a drug and lipids may be critical for the pharmacological activity. We previously showed that the ability of a fluoroquinolone antibiotic, ciprofloxacin, to induce disorder and ... [more ▼]. The interactions between a drug and lipids may be critical for the pharmacological activity. We previously showed that the ability of a fluoroquinolone antibiotic, ciprofloxacin, to induce disorder and modify the orientation of the acyl chains is related to its propensity to be expelled from a monolayer upon compression [1]. Here, we compared the binding of ciprofloxacin on DPPC and DPPG liposomes (or mixtures of phospholipids [DOPC:DPPC], and [DOPC:DPPG]) using quasi-elastic light scattering and steady-state fluorescence anisotropy. We also investigated ciprofloxacin effects on the transition temperature (T(m)) of lipids and on the mobility of phosphate head groups using Attenuated Total Reflection Fourier ...
TY - JOUR. T1 - Hydrogen bonding and liquid crystallinity of low molar mass and polymeric mesogens containing benzoic acids. T2 - a variable temperature Fourier transform infrared spectroscopic study. AU - Martinez-Felipe, A.. AU - Cook, A. G.. AU - Wallage, M. J.. AU - Imrie, C. T.. N1 - The work is supported by the Spanish Ministry of Science and Innovation through the Research Project, ENE2011-28735-C02-01, the Generalitat Valenciana through the schemes GRISOLIAP/ 2010/057 and APOSTD/2013/054, and UPV through the Research Project PAID-06-11.. PY - 2014/12/2. Y1 - 2014/12/2. N2 - The phase behaviour and mesomorphism of poly(4-(6-propenoyloxyhexyloxy)benzoic acid) (PPOHBA) and 4-pentyloxybenzoic acid (POBA) is studied using variable-temperature Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction. PPHOBA exhibits a smectic C phase and POBA, a nematic phase. The temperature dependence of the Fermi resonance bands associated with the hydroxyl groups and of the carbonyl stretching ...
Autori: I. Bratu, M. T. Cotisel, G. Damian, A. Mocanu. Editorial: INOE&INFM, Journal of Optoelectronics and Advanced Materials, 9(3), p.675-677, 2007.. Rezumat:. Structural information of barley aleurone at various temperatures is obtained by analysis of the conformationally-sensitive amide I band using FT-IR spectroscopy. The second derivative spectrum was performed in order to overcome the bands overlapping due to the different C=O stretching vibrations of each type of secondary structure (i.e. alpha-helix, beta-sheet, turns and unordered). The results of quantitative analysis by curve fitting to the inverted second derivative spectra indicate perturbations of both alpha-helix and beta-sheet structures in thermal unfolding process, depending on the temperature values.. Cuvinte cheie: FT IR spectroscopy, Secondary structure, Proteins, Barley aleurone, Deconvolution. ...
In the study presented here, the performance of FTIR and MALDI-TOF MS for typing clinical Klebsiella isolates was evaluated with regard to the discriminatory power of these rapid analysis methods. WGS was employed as a reference to analyze a set of Klebsiella strains recovered from clinical specimens. The adjusted Rand index was used to determine the congruency of the respective spectrum-based typing method in comparison to the reference (31).. High agreement between FTIR- and WGS-based clustering was obtained in our study. This is in line with reports that found good discrimination of other clinically or environmentally relevant Gram-negative organisms, such as Y. enterocolitica (11, 36), E. coli (10), and Klebsiella oxytoca (37). These findings might reflect the fact that FTIR spectra are prominently shaped by components of the Gram-negative cell wall or capsule molecules and that high diversity among these structures (e.g., O antigens or capsule types) underlies successful discrimination by ...
FT-IR and 2D correlation spectroscopy were employed to study the microstructural changes ocurring during phase transitions of a liquid crystal poly(amidoamine) codendrimer (PAMAM (L1)16(L2)16) generation 3, functionalized on the terminal groups by one-chain promesogenic calamitic units (4-(4-decyloxybenzoyloxy)salicylaldehyde (L1)) and two-chain promesogenic calamitic units (4-(3,4-didecyloxybenzoyloxy)salicylaldehyde (L2)). Spectral modifications associated with molecular conformation rearangements allowing for molecular shape change on going from a liquid−crystalline organization to another were found. The transition temperatures were calculated, and they are in good agreement with the DSC data. Spectral analysis gives evidence of the LC phase transitions and to an additional transition associated with the existence of conformers. Various types of hydrogen bonding have been established ...
In situ Fourier transform infrared studies have shown that the electrochemical hydrodehalogenation (HDH) of a wide range of halogenated phenols to give the phenolate anion was observed through a common adsorbed intermediate at a palladium catalysed titanium electrode. The mechanism of the reduction may be represented as a sequence of electron additions and halide expulsions leading, via the intermediate radical, to product. The electrochemical HDH of halogenated phenols in aqueous solution was studied at ambient temperature and atmospheric pressure in a two-compartment H-cell reactor and a solid polymer electrolyte reactor, as well as with in situ Fourier transform infrared (FTIR) spectroscopy. Complete dehalogenation of 10mM halogenated phenol solutions was observed with current efficiencies up to 90% in the H-cell, whilst current efficiencies up to 50% were observed using the solid polymer electrolyte reactor. © 2004 Elsevier B.V. All rights reserved.. ...
Fourier transform infrared spectroscopy (FTIR spectroscopy) covers a wide range of chemical applications, especially for polymers and organic compounds. Learn more about the basics of this chemical analysis technique.
TY - JOUR. T1 - Relation between thermal stabilizing effect of sucrose on LDH and sucrose-LDH hydrogen bond. AU - Suzuki, T.. AU - Imamura, Koreyoshi. AU - Fujimoto, H.. AU - Okazaki, M.. PY - 1998/8. Y1 - 1998/8. N2 - The thermal stabilizing effect of sugar on freeze-dried protein is studied, in particular on the relationship between the thermal stabilizing effect and the degree of sugar-protein hydrogen bond formation. Sucrose and lactate dehydrogenase (LDH) are used as models for sugar and protein. Several freeze-dried samples of LDH involved in sucrose were prepared; they differed in the degree of crystallinity of sucrose. By X-ray diffractometry (XRD) and Fourier transform infrared (FT-IR) spectroscopy, it is found that when sucrose is amorphous in the samples, the degree of hydrogen bond formation is high and LDH is stabilized remarkably. In contast, when sucrose is crystalline, the degree of hydrogen bond formation is low and LDH is inactivated. These results indicate that the stabilizing ...
Thermochromic VO{sub 2} was directly synthesized using hydrothermal techniques. The effects of formation conditions on the structure and morphology of the final product were studied through X-ray diffraction (XRD), and scanning electron microscopy (SEM). Unique hollow sphere morphology was observed for the synthesized VO{sub 2} powders. Ex-situ XRD studies after heat treatment confirmed the thermal stability of the VO{sub 2} structure. Thermochromic properties, as a consequence of the reversible structural transformation between monoclinic VO{sub 2} and tetragonal phases, were observed by Fourier transform infrared spectroscopy (FTIR). - Graphical abstract: Thermochromic VO{sub 2} crystals with hollow spherical and asterisk shape were directly synthesized using hydrothermal techniques. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies confirmed the thermal stability and the reversible thermochromic properties of the VO{sub 2} structure. - Highlights: • One-step ...
Fourier Transform Infrared (FT-IR) spectra in the amide I region of different GTFB preparations. Soluble GTFB, refolded GTFB, and ncIB GTFB proteins isolated fr
Applications and Uncertainties Associated with Measurements Using Fourier Transform Infrared Spectrometry, Gas Chromatography-Mass Spectrometry and Selective Ion Electrode Method in Fire Suppression Tests
Biological calcium phosphates are, with few exceptions, poorly or partly crystalline and impure, and sometimes comprise a mixture of phases. Each component of a complex calcified deposit may be...
Najbjerg, Heidi; Afseth, Nils Kristian; Young, Jette F.; Bertram, Hanne; Pedersen, Mona Elisabeth; Grimmer, Stine J Staavi; Vogt, Kjell gjermund; Kohler, Achim ...
Variations in biochemical features are extensive among cells. Identification of marker that is specific for each cell is essential for following the differentiation of stem cell and metastatic growing. Fourier transform infrared spectroscopy (FTIR) as a biochemical analysis more focused on diagnosis of cancerous cells. In this study, commercially obtained cell lines such as Human ovarian carcinoma (A2780), Human lung adenocarcinoma (A549) and Human hepatocarcinoma (Hepg2) cell lines in 20 individual samples for each cell lines were used for FTIR spectral measurements. Data dimension were reduced through principal component analysis (PCA) and then subjected to neural network and linear discrimination analysis to classify FTIR pattern in different cell lines. The results showed dramatic changes of FTIR spectra among different cell types. These appeared to be associated with changes in lipid bands from CH2 symmetric and asymmetric bands, as well as amide I and amid II bands of proteins. The PCA-ANN
Fourier transform infrared spectroscopy has been applied to study the thermal stability of multilayer Langmuir- Schaefer (LS) films of lysozyme deposited on silicon substrates. The study has confirmed previous structural findings that the LS protein films have a high thermal stability that is extended in a lysozyme multilayer up to 200 °C. 2D infrared analysis has been used here to identify the correlated molecular species during thermal denaturation. Asynchronous 2D spectra have shown that the two components of water, fully and not fully hydrogen bonded, in the high-wavenumber range (2800-3600 cm-1) are negatively correlated with the amine stretching band at 3300 cm-1. On the grounds of the 2D spectra the FTIR spectra have been deconvoluted using three main components, two for water and one for the amine. This analysis has shown that, at the first drying stage, up to 100 °C, only the water that is not fully hydrogen bonded is removed. Moreover, the amine intensity band does not change up to ...
최근, 지구온난화 문제로 이산화탄소를 흡착할 수 있는 물질에 관심이 커지고 있다. 아미노산과 MgAl-LDH는 이산화탄소 제거를 위한 흡착 물질로 알려져 있다. 그러므로 아미노산이 층간 삽입된 LDH는 이산화탄소를 제거하기 위한 적절한 흡착제로 이용될 수 있다고 판단된다. 이 연구에서 우리는 아미노산-MgAl-LDH 나노하이브리드를 만들고 이 물질에 이산화탄소를 화학적으로 흡착시켜 카바메이트 형성을 통해 이산화탄소를 흡착시켰다. 종류가 다른 두가지 아미노산인 페닐알라닌(Phe)과 글루타믹에씨드(Glu)를 LDH안에 성공적으로 붙였다. X-ray diffraction 분석을 통하여 Phe 과 Glu 분자가 성공적으로 LDH안에 층간 삽입 되었고, MgAl-NO3-LDH (0.88 nm) 와 비교해 보았을 때 Phe-LDH와 Glu-LDH의 basal spacing이 각각 1.8 nm, 1.22 nm임을 증명할 수 있다. Fourier transform infrared spectra 를 이용해 ...
This application note describes the monitoring of the peptide product of the chymotrypsin-catalysed hydrolysis of N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (Suc-AAPF-pNA) by FT-IR spectroscopy. This reaction can be followed by FT-IR due to the formation of a new C-terminal carboxylate group. The VERTEX 80 FT-IR spectrometer was shown to collect more than 100 spectra at resolution 16 cm-1 per second at the fastest mirror velocity (320 kHz).
The FTIR spectra in this library are stored as bitmap picture files in .PNG format.. To save a file, right-click and select "Save Picture As…". These figures are distributed under the terms of the Creative Commons Attribution License which permits unrestricted use, distribution and reproduction in any medium, provided the original source (this website) is properly cited. To view a spectrum, select a sample from the dropdown list below. Except where stated, the spectral range plotted is the mid-infrared "fingerprint" region (600 ~ 1900 wavenumbers).. ...
Video articles in JoVE about near infrared spectroscopy include Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies, Construction of Models for Nondestructive Prediction of Ingredient Contents in Blueberries by Near-infrared Spectroscopy Based on HPLC Measurements, Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase, Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with one Stop Shop Near-infrared Spectroscopy, Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy, High-definition Fourier Transform Infrared (FT-IR) Spectroscopic Imaging of Human Tissue Sections towards Improving Pathology, Diffuse Reflectance Infrared Spectroscopic Identification of Dispersant/Particle Bonding Mechanisms in Functional Inks, In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by
The model six-residue linear peptide AAGDYY-NH2 from TEM-1 beta -lactamase inhibitor protein and BLIP was predicted to adopt a beta -turn conformation and synthesized in order to elucidate the mechanism of beta -turn formation and stability. Its structural preferences in solution were comprehensively characterized using CD (circular dichroism), FT-IR and H-1-NMR spectroscopy. The set of observed short- and medium-range NOEs, the restrained molecular dynamics simulation, CD and FT-IR spectroscopy were consistent with the formation of beta -turn in solution by the model peptide. The results implicate beta -turn playing an important role in the process of protein folding. ...
Authors: FATİH SEMERCİ Abstract: New coordination polymers, formulated as {[Zn($\mu $-sipH)($\mu $-apim)]$\cdot $3H$_{2}$O} $_{n}$ (1) and {[Cd($\mu $-sip)(H$_{2}$O)$_{2}$ (apimH)]$\cdot $3H$_{2}$O}$_{n}$ (2) were synthesized based on the 1-(3-aminopropyl)imidazole (apim) along with 5-sulfoisophthalate (sip) ligands. The complexes were synthesized under mild hydrothermal conditions. All the complexes were characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction studies. The X-ray crystallographic studies of 1 and 2 reveal Zn(II) and Cd(II) ions are $\mu $-bridged by dianionic sipH and trianionic sip ligands in bis(monodentate) and bis(bidentate) coordination mode, respectively, to generate 1D polymer chains. In complex 1, the adjacent chains are linked by two apim ligands to form a 1D nanotubular structure. Complex 2 is the first example of a protonated apimH ligand. In the complexes the adjacent 1D chains extend into a 3D supramolecular network by hydrogen ...
IDPs in their unbound state can transiently acquire secondary and tertiary structure. Describing such intrinsic structure is important to understand the transition between free and bound state, leading to supramolecular complexes with physiological interactors. IDP structure is highly dynamic and, therefore, difficult to study by conventional techniques. This work focuses on conformational analysis of the KID fragment of the Sic1 protein, an IDP with a key regulatory role in the cell-cycle of Saccharomyces cerevisiae. FT-IR spectroscopy, ESI-MS, and IM measurements are used to capture dynamic and short-lived conformational states, probing both secondary and tertiary protein structure. The results indicate that the isolated Sic1 KID retains dynamic helical structure and populates collapsed states of different compactness. A metastable, highly compact species is detected. Comparison between the fragment and the full-length protein suggests that chain length is crucial to the stabilization of ...
In an effort to understand chemical substances and document the potential impact on human health and the environment, the European Union (EU) developed the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) initiative. The REACH regulation applies to all chemicals that are imported to or produced in the EU. As part of the registration of a chemical substance, complete chemical characterization is required. Using spectroscopic techniques, such as NMR and FT-IR spectroscopy, molecular characterization techniques such as mass spectrometry, and separations techniques such as gas or liquid chromatography, the chemical structure and impurities can be identified and purity can be determined. Impact Analytical has extensive experience in performing these types of characterizations for REACH submission, providing a complete report that complies with REACH documentation and regulatory requirements. ...
Heyes CD, Wang J, Sanii LS, EL-Sayed MA. Fourier transform infrared study of the effect of different cations on bacteriorhodopsin protein thermal stability. Biophysical journal [Internet]. 2002 ;82(3):1598-1606. Available from: http://dx.doi.org/10.1016/S0006-3495(02)75511-2 ...
FT-IR spectroscopy - IRPrestige-21 spectrophotometer with wavenumber range 7,800 - 350 cm-1 . DLATGS detector with Temperature Control for Middle/Far IR, MCT(Hg-Cd-Te) detector with Liquid Nitrogen Cooling for Middle IR, VeeMaxTM II with ATR (variable angle of incidence - 30 to 75 degrees).. ...
This study explores the use of FT-IR spectroscopy and PLS regression for the authentication of essential oils-wintergreen oil, tea tree oil, rosemary oil, and lemon eucalyptus oil-adulterated with either lemongrass oil or peppermint oil ...
This study explores the use of FT-IR spectroscopy and PLS regression for the authentication of essential oils-wintergreen oil, tea tree oil, rosemary oil, and lemon eucalyptus oil-adulterated with either lemongrass oil or peppermint oil ...
The aim of this work was to obtain the physicochemical properties by SEM, XRD, FTIR analyses and the surface characteristics from carbonate outcrops cores such as pore diameter, surface area, porosity and permeability. The methods used to characterize them were Scanning Electron Microscopy, SEM; X Ray Diffraction, DRX; Fourier Transform Infrared Spectroscopy, FTIR. The porosity and permeability of natural vuggy fractured porous medium from core samples was determined obtained in the laboratory with conventional procedures. The cores have smooth and rough surfaces with porous with several sizes. Some crystals appear in preferential zones mainly composed by calcium, carbon and oxygen. Apparently into free spaces were found the organic materials, organic residues of crude oil. The cores have smooth and rough surfaces with porous with several sizes. Some crystals appear in preferential zones composed by calcium, carbon and oxygen. Apparently into free spaces were found the organic materials, organic
Innovative techniques and improvements in instrumentation are expanding the potential of Fourier transform infrared spectroscopy in bio applications a
A multi-component Fourier Transform InfraRed (FTIR) gas analyzer with a low spectral resolution (8cm-1) is described in this paper. The hardware of this analyzer is consisting of a rugged Fourier Transform Spectrometer (FTS), an uncooled pyroelectric Deuterated L-Alanine TriGlycine Sulfate (DLATGS) detector, a glass body long-path gas cell and relevant sampling devices. The transplantable software and algorithms include the building of spectral library from the free sources such as EPA, NIST, HITRAN etc, identification of spectrum components and a modified classical least square regression with automatic baseline compensation. In order to validate this system, we implemented a continuous on-line experiment using the 55 μmol·mol-1 methane and 28 μmol·mol-1 nitrous oxide standard mixtures. The experimental results show this low resolution analyzer has accuracy and robust analysis abilities. The description in this paper is helpful to facilitate the development of a FTIR multi-component gas ...
The effect of lead press on maize seeding was investigated by energy dispersive spectrometer(EDS) and Fourier transform infrared-attenuated total reflection(FTIR-ATR) spectrometry with the physiological traits changes.With the enhancement of Pb2+ concentration,the activities of antioxidative enzyme(such as SOD,CAT,POD) would increase at first and then decrease.The peak shape of plant component remained invariable basically by IR spectrum.Significant absorption peak shift of some function groups such as hydroxyl groups(3328-3361cm-1) and acidamide groups(1620-1645cm-1) can be obtained when they participated in the process of absorbing Pb2+.The increased concentration of Pb2+ affected on the absorption of other nutrients,that was obtained by EDS.
Read independent reviews on FTIR - Coupling for Fourier-Transform Infrared spectrometer from NETZSCH-Gerätebau GmbH on SelectScience
Processing of mesoporous films is a critical step that needs a careful control and comprehension of the chemical−physical phenomena that governs evaporation induced self-assembly. We have used time-resolved infrared spectroscopy to study two of the main stages of self-assembly in titania films: evaporation and postdeposition drying. Mesostructured titania cast films have been prepared by using a triblock copolymer (Pluronic F127) and TiCl4 as the titania precursor. A droplet of the precursor titania sol has been cast, and the unimer to micelle evolution has been observed. The drying stage, in the 25−165 °C temperature range, has been studied in situ by infrared spectroscopy. We have observed that upon drying, with complete removal of water, the block copolymer crystallizes; this process is reversible and can be reproduced several times. The infrared data have also given some additional information about the nature of hybrid surfactant−titania oxo-clusters interface, which appears formed ...
A tensor is said to be antisymmetic if T = -Tr. , and Any tensor T can always be decomposed into the sum of a symmetric tensor and an antisymmetric tensor. In fact, where and It is not difficult to prove that the decomposition is unique (see Prob. 1 Show that if T is symmetric and W is antisymmetric, then tr(TW)=0. Solution. 4] T T Since T is symmetric and W is antisymmetric, therefore, by definition, T=T , W= - W . 1) Consequently, 2tr(TW)=0. That is, 2B16 The Dual Vector of an Antisymmetric Tensor The diagonal elements of an antisymmetric tensor are always zero, and, of the six nondiagonal elements, only three are independent, because T^i ~ ~^12>^13= ~^3i and T23 = ~ r32. Solution. We note that this tensor is 21, so that Ta = 2Ia = 2a, for any vector a. Therefore, by the definition of eigenvector,(see Eq. 1)), any direction is a direction for an eigenvector. The eigenvalues for all the directions are the same, which is 2. However, we can also 40 Tensors use Eq. 3) to find the eigenvalues and ...
Smith, GD; Chen, PY; Chao, JL; Omberg, KM; Kavaliunas, DA; Treadway, JA; Meyer, TJ; Palmer, RA, Step-scan Fourier transform infrared absorption difference time-resolved spectroscopy studies of excited state decay kinetics and electronic structure of low-spin d(6) transition metal polypyridine complexes with 10 nanosecond time resolution, Laser Chemistry, vol. 19 no. 1-4 (1999), pp. 291-298, ISSN 0278-6273 ...
This article describes the application of multivariate statistical process control techniques to a series of mid-infrared spectra collected online from a styrene/ 2-ethylhexyl acrylate emulsion copolymerization process. Principal component analysis of the mid-infrared spectral data indicated that in situ monitoring of the complex copolymerization process was feasible in the spectral region of interest. It was also observed that projection to latent structures or partial least squares (PLS) could be used for the effective indirect online prediction of individual monomer conversions and copolymer compositions over a substantial range of process operating conditions. A combination of the developed PLS methodology with a mid-infrared attenuated total reflection probe proved to be an effective tool for the efficient online characterization of polymer quality, thereby overcoming the lack of robust online conversion and composition measuring devices. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci ...
The adsorption of CO2 and CO was investigated on a pure γ-Al2O3 support material that has been used in Pd and Ru catalysts for the reduction of CO2. The adsorption of CO2 resulted in the formation of carbonates, bicarbonates and linearly adsorbed CO2 species. The amount and the nature of the adsorbed species
Adsorption, Methods, PH, Water, 5-fluorouracil, 5-fu, Behavior, Calorimetry, Cancer, Differential Scanning Calorimetry, Electron, Electron Microscopy, Fluorouracil, Fourier Transform, Fourier Transform Infrared Spectroscopy, Gels, Hydrogels, Ionic Strength, Microscopy, Polymerization
2011 (engelsk)Inngår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, nr 6, s. 1433-1440Artikkel i tidsskrift (Fagfellevurdert) ...
The inclusion complexes of imazapyr (IMA) with cucurbit[n]uril, CB[n] (n=6-8), have been investigated. Fluorescence spectroscopy, MALDI-TOF, and 1HNMR were used to investigate and characterize the inclusion complexation of IMA and CB[n] in solutions. Whereas the solid state complexes have been characterized by Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (PXRD). IMA was found to form 1:1 complexes with CB[n] with association constants ranging from 5.80×102-2.65×103. The guest molecule IMA was found to encapsulate into the larger cavities of CB[7] and CB[8], whereas with CB[6] the molecule remains outside the cavity ...
Preliminary results of evaluation of progress in chemotherapy for childhood leukemia patients employing Fourier-transform infrared microspectroscopy and cluster … Academic Article ...
The mesoporous ZrFe2O4 nanocauliflowers were synthesized via the solvothermal method. The core-shell [email protected] nanocomposite was successfully prepared by a simple wet route using tetraethylorthosilicate, then modified with (3-aminopropyl)triethoxisilan (APTES) as linker and tetrakis(4-carboxyphenyl)porphyrin (TCPP) as agent for light harvesting, to fabricate [email protected] nanocomposite. The characterizations of samples were done by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), nitrogen adsorption and desorption isotherms (BET), vibrating sample magnetometer (VSM), diffuse reflectance spectroscopy (DRS) and fluorescence spectroscopy. The prepared samples were applied as photocatalyst to remove of methyl orange (MO) under visible LED light irradiation. The obtained results showed that the presence of SiO2 and TCPP decreased the size of particles and improve the photocatalytic
Homan, J., Radel, J., Wallace, D., & Levine, S. (2000). Chemical changes in the photoreceptor outer segments due to iron induced oxidative stress: Analysis by Fourier transform infrared (FT-IR) microspectroscopy. Cellular and Molecular Biology, 46(3), 663 - 672 ...
ABSTRACT-Cracking, flaking, and separation of paint films containing lead white from the substrate on medieval parchment manuscripts and other works of art have been frequently reported by conservators. In this study, Fourier transform infrared spectroscopy (FTIR) was used to follow up the changes induced by the pigment on some properties of proteinaceous binding media commonly mentioned in medieval treatises. Evidence of the removal of water molecules from the vicinity of the peptide linkage groups C=O and CNH, with a small change in the proteins secondary structure due to aggregation, was obtained. The properties of the lead white-binder samples were compared to those of massicot-containing mixtures. Massicot was also found to promote aggregation of the binders, though it induces a smaller change than does lead white in the hydrogen-bonding characteristics of the peptide CNH group.. TITRE-Caract risation par FTIR de leffet du blanc de plomb sur certaines propri t s des liants prot iques. R ...
Enhancement of L-lactic acid polycondensates by involving of postpolycondensation reactions in solid state under vacuum and catalyzed by stannous 2-ethylhexanoate were studied in the presented work. The catalyst was used only in postpolycondensation step. An effect of the catalyst concentration and postpolycondensation reaction time on resulting properties of poly(lactic acid) was studied by gel permeation chromatography. Fourier transform infrared spectroscopy and differential scanning calorimetry. Results show significant enhancement of molecular weight in case of the systems containing 2 wt. % of the catalyst due to the postpolycondensation procedure (M-W similar to 91.0 kg/mol; i.e. 1655 % after 24 hours). However, further progress can be assumed with increasing reaction time. This enhancement of poly(lactic acid) molecular weight had a response corresponding to changes of both physico-chemical and thermal properties of the solid state postpolycondensation products ...
Tissue engineering is currently one the fastest growing engineering fields, requiring fabrication of advanced and multifunctional materials to be used as scaffolds or dressing for tissue regeneration. In this work, a bilayer matrix was fabricated by electrospinning of a hybrid cellulose acetate nanofibers (CA) containing bioactive latex or Ciprofloxacin over highly interconnected collagen (CSPG) 3D matrix previously obtained by a freeze-drying process. The bilayer matrix was fabricated with a nanofibrous part as the primary (top) layer and a spongy porous part as the secondary (bottom) layer by combining electrospinning and freeze-drying techniques to enhance the synergistic effect of both materials corresponding to physical and biological properties. The final material was physicochemically characterized using Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The bilayer matrix exhibited nanofibrous and 3D porous structure with properties such as high ...
|p|Abstract In this work, FeOOH arrays were obtained using two different magnetic cations. The nanoparticles were grouped into a package having different orientations through the van der Waals interaction with the magnetic cations. With Fe2+, the FeOOH nanoparticles have a rod shape with a 30-nm diameter and approximately 1-micron length, and are aligned in a star structure. With Co2+, a somatoidal shape was observed, with 20-nm diameter and 150-nm length and a pathway structure to the array. The chemical synthesis method was used to obtain the nanoarrays. The morphology and the average size of the nanorods and nanowires were determined using Field Emission Scanning Electron Microscopy (FESEM). Fourier Transform Infrared Spectroscopy (FTIR) was used to study the interaction between the nanorods and the cobalt ions. The phases of the material were identified using X-ray Diffraction. Graphical abstract |inline-formula||alternatives| [...] |/alternatives||/inline-formula||/p|
Abstract: Molecularly imprinted hydrogels for the capture of the peptide hormone hepcidin were prepared by water-in-oil (w/o) suspension polymerization under mild conditions. Spherical and relatively uniformly sized gel beads were routinely obtained after optimization of the synthetic methodology. The polymers were analyzed by Fourier transform infrared spectroscopy, optical microscopy, and scanning electron microscopy. Although the imprinted materials exhibited higher affinity towards the epitope template (hepcidin N-terminus) than their corresponding blank polymers, the full-length target peptide was found strongly bound to all the hydrogels tested. However, by using whole fluorescent hepcidin as the print species, the imprinting effect was more pronounced. Moreover, bovine serum albumin did not bind to the poly N-isopropylacrylamide (PNIPAm)-based polymers. Thus, polymeric ldquospongesrdquo for biomacromolecules with size-exclusion effect were developed, useful for peptide concentration, ...
The CalMex campaign was conducted from May 15 to June 30 of 2010 to study the properties and sources of air pollution in Tijuana, Mexico. In this study, submicron organic aerosol mass (OM) composition measured by Fourier Transform Infrared Spectroscopy (FTIR), Aerosol Chemical Speciation Monitor (ACSM), and X-ray spectromicroscopy are combined with statistical analysis and measurements of other atmospheric constituents. The average (±one standard deviation) OM concentration was 3.3 ± 1.7 μg m−3. A large source of submicron aerosol mass at this location was determined to be vehicular sources, which contributed approximately 40% to the submicron OM; largely during weekday mornings. The O/C ratio estimated from ACSM measurements was 0.64 ± 0.19; diurnal variations in this value and the more oxygenated fraction of OM as determined from Positive Matrix Factorization and classification analyses suggest the high degree of oxygenation originates from aged OM, rather than locally-produced secondary ...
A Day Conference of Scientific Research on Modern Paper Sala Consiliare Comunale Municipio di Zero Branco (Tv), Italy 24 October 2009 The nineteenth century saw a revolution in the manufacture of paper (from rags-gelatine to woodpulp-rosin), which lasted until years 40-50 of 900. Since then the ever increasing demand for paper materials led to the development of additional media of various compositions, whose knowledge is essential for the conservation and restoration of modern document. The chemical and instrumental analysis of modern paper poses considerable diagnostic problems. The Fourier Transform Infrared Spectroscopy (FTIR) is a technique easy to use and completely non-destructive/intrusive which allows an initial screening of the composition of modern paper documents and their degradation. The degradation of paper documents occurs mostly through the processes of acid hydrolysis and oxidation of cellulose. A promising deacidification process is the treatment of paper using a colloidal ...
A novel wire mesh cell for studying lipid oxidative processes by fourier transform infrared spectroscopy.: A novel infrared (IR) sample handling accessory has
The use of such methods for solving evolutionary PDEs has become increasingly common due to the availability of the required built-in commands in major computational software such as Matlab and Fortran. The idea of the method is based on the following property of the Fourier transform of a function. If f(k) is the Fourier transform off (x) with respect to x, then (-ik)mf(k) is the Fourier transform of Smf(x). Here i = \J - 1 and k is the parameter of the Fourier transform, sometimes referred to as the wave number or frequency. For example, in Matlab, fft and ifft are the commands of the Fourier transform and the inverse Fourier transform. (The entire acronym stands for Fast Fourier transform; similar commands are available in Fortran and C.) Then if k is the transform parameter properly defined within the code, then S^u can be computed for all x at once by a short command: real ( ifft(-(k.~2) .*fft(u) ) ). (Here the command real discards a very small imaginary part of the answer which arises ...
Dammers, E., M. Palm, M. Van Dammel, C. Vigouroux, D. Smale, S. Conway, G.C. Toon, N. Jones, E. Nussbaumer, T. Warneke, C. Petri, L. Clarisse, C. Clerbaux, C. Hermans, E. Lutsch, K. Strong, J.W. Hannigan, H. Nakajima, I. Morino, B. Herrera, W. Stremme, M. Grutter, M. Schaap, R.J. Wichink Kruit, J. Notholt, P.F. Coheur and J.W. Erisman. 2016. An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements. Atmos. Chem. Phys. 16(16):10351-10368 ...
Adsorption-mediated CO2 separation can reduce the costs of carbon capture and storage. The reduction in cost requires adsorbents with high capacities for CO2 sorption and high CO2-over-N2 selectivity. Amine-modified sorbents are promising candidates for carbon capture. To investigate the details of CO2 adsorption in such materials, we studied mesocaged (cubic, Pm3n symmetry) silica adsorbents with tethered propylamines using Fourier transform infrared (FTIR) spectroscopy and volumetric uptake experiments. The degree of heterogeneity in these coatings was varied by either co-synthesizing or post-synthetically introducing the propylamine modification. In situ FTIR spectroscopy revealed the presence of both physisorbed and chemisorbed CO2 in the materials. We present the first direct molecular evidence for physisorption using FTIR spectroscopy in mesoporous silica sorbents modified with propylamines. Physisorption reduced the CO2-over-N2 selectivity in amine-rich sorbents. Samples with homogenous ...