The epithelial-cell layer lining the two morphologically and functionally distinct segments of the mammalian intestinal tract, small intestine, and colon is constantly being renewed. This renewal is necessitated by a harsh lumen environment and is hypothesized to be driven by a small population of stem cells (SCs) that are believed to reside at the base of intestinal crypts. A lack of specific markers has hampered previous attempts to identify their exact location. We obtained tissue sections containing small intestine and colon crypts derived from normal (benign) or adenocarcinoma (AC) human intestine. The samples were floated onto BaF2 windows and analyzed using synchrotron radiation-based Fourier transform infrared microspectroscopy via an aperture size of 10 × 10 μm. Derived infrared (IR) spectral data was then analyzed using principal component analysis and/or linear discriminant analysis. Hypothesized cell types (as a function of aperture location along the length of individual crypts) ...

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. ...

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 ...

Microspectrophotometric Measurements of Deoxyribonucleic Acid in Feulgen-Stained Nuclei of the Anterior Pituitary Cells of the White ...

E2808 - 11 Standard Guide for Microspectrophotometry and Color Measurement in Forensic Paint Analysis , color, color measurement, forensic paint analysis, microspectrophotometry, MSP,

ABSTRACT-UV-visible reflectance spectroscopy and Raman microspectroscopy provide a rapid way to unequivocally identify the pre-Columbian pigment Maya blue. Spectra of modern synthetic materials are compared with data from a contextualized archaeological sample and from an object in the collection of the Los Angeles County Museum of Art. UV-visible spectroscopy and Raman microspectroscopy, together with complementary techniques such as Fourier transform infrared microspectroscopy, reveal significant differences between spectra of indigo as pure crystalline solid or as complexed by palygorskite. These techniques are thus extremely specific, being able to identify Maya blue as a prepared pigment rather than detecting only its ingredients, indigo and palygorskite. Fiber optics UV-visible reflectance spectroscopy and Raman microspectroscopy present the additional advantage of being completely noninvasive and therefore suitable for the study of works of art. Lightweight portable fiber optics ...

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 microspectrophotometer from CRAIC Technologies is used for microspectrophotometry and imaging of microscopic areas or samples in the UV-visible-NIR.

Apparatus and methods are described for the determination of infrared spectral absorption of solutions containing about 1 gamma (10−6 g) of solute. The absorption cell used is a piece of capillary tubing made of silver chloride with a central hole about 0.075 mm in diameter. The cells have lengths of 1 to 1.5 mm and are filled by means of a micropipette. A magnified image of the cell is then projected on the entrance slit of a spectrometer, and the spectral data are recorded. Results with typical organic compounds indicate that satisfactory spectral resolution may be obtained with this capillary cell.. © 1952 Optical Society of America. Full Article , PDF Article ...

Microspectrophotometer definition, a spectrophotometer for examining light emitted, transmitted, or reflected by minute objects. See more.

CRAIC designs advanced ultraviolet-visible-near-infrared microspectrophotometer, UV microscope, NIR microscope, SWIR microscope, Raman microspectrometer, Raman microscope, microscope spectrophotometer and microscope spectrometer solutions for non-destructive analysis of microscopic samples by transmission and fluorescence and reflectance and polarization microspectroscopy.

This ground-breaking book investigates spatially resolved spectroscopic techniques for the characterization and improvement of engineering polymers. It is the first book to develop micro-spatial spectroscopic techniques for polymers. It also discusses the theory, instrumentation, and sampling techniques of optical, infrared, Raman, and NMR microspectroscopic imaging techniques for polymers, and includes numerous practical applications.

This ground-breaking book investigates spatially resolved spectroscopic techniques for the characterization and improvement of engineering polymers. It is the first book to develop micro-spatial spectroscopic techniques for polymers. It also discusses the theory, instrumentation, and sampling techniques of optical, infrared, Raman, and NMR microspectroscopic imaging techniques for polymers, and includes numerous practical applications.

TY - CONF. T1 - FT-IR microspectroscopic analysis of lymphocytes stimulated with phythohaemagglutinin. AU - Wood, Bayden R. AU - Tait, Brian. AU - McNaughton, Donald. PY - 1998. Y1 - 1998. M3 - Other. SP - 45. EP - 46. ER - ...

The MINERVA-64 software allows the user to control CRAIC microspectrophotometers and to acquire high quality ultraviolet, color and near infrared spectra of microscopic samples by absorbance, reflectance or fluorescence. The software is then used to analyze those microspectra . Designed for the production environment as well as the laboratory, it incorporates a number sophisticated tools for analyzing spectra. It also incorporates two modes of operation: a production level with recipe driven instrument control and data analysis in addition to a password protected engineering mode for creating those recipes and for advanced research ...

The role of water in the methanol-to-olefins (MTO) process over H-SAPO-34 has been elucidated by a combined theoretical and experimental approach, encompassing advanced molecular dynamics simulations and in situ microspectroscopy. First-principles calculations at the molecular level point out that water competes with methanol and propene for direct access to the Bronsted acid sites. This results in less efficient activation of these molecules, which are crucial for the formation of the hydrocarbon pool. Furthermore, lower intrinsic methanol reactivity toward methoxide formation has been observed. These observations are in line with a longer induction period observed from in situ UV-vis microspectroscopy experiments. These experiments revealed a slower and more homogeneous discoloration of H-SAPO-34, while in situ confocal fluorescence microscopy confirmed the more homogeneous distribution and larger amount of MTO intermediates when cofeeding water. As such, it is shown that water induces a more ...

CRAIC designs advanced ultraviolet-visible-near-infrared microspectrophotometer, ultraviolet-visible-near-infrared microscope and microscope spectrometer for non-destructive analysis of microscopic samples by transmission and fluorescence and reflectance and polarization microspectroscopy.

SELECTED RECENT PUBLICATIONS Yakubovskaya, E, Zaliznyak T, Martínez Martínez J. Taylor GT (2019). Tear down the fluorescent curtain: A new fluorescence suppression method for Raman microspectroscopic analyses. Scientific Reports, 9: 15785. doi:10.1038/s41598-019-52321-3. Louca S, Astor YM, Doebeli M, Taylor GT, Scranton MI. (2019) Microbial metabolite fluxes in a model marine anoxic ecosystem. Geobiology 17:628-642. doi: 10.1111/gbi.12357. Weber, F, Zaliznyak, T, Taylor GT (2019) Sample preparation for 3D-Raman microspectroscopic mapping of fully hydrated protist cells. https://www.protocols.io/view/sample-preparation-for-3d-raman-microspectroscopic-ztyf6pw. Louca S, Scranton MI, Taylor GT, Crowe SA, & Doebeli M. (2019). Circumventing kinetics in biogeochemical models. Proc. Natl. Acad. Sci. (USA) https://doi.org/10.1073/pnas.1819883116 Taylor GT. (2019). Windows into microbial seascapes: Advances in nanoscale imaging and application to marine science. Annual Review of Marine Sciences 11: ...

Working out daily with a set of home gym equipment is the best way to gain strength and keep yourself fit rather than hitting out to a nearby gym every day. The reason that it may take more time and money and also not getting enough opportunities to work out on personal fitness goals, designing your home gym can make a high impact on the shape of your life. At home, you might get wholly comfortable, which you may not get at the gym with all so-many performers. At the home gym, you have it personal, and you know how to start when to exercise and most importantly, how to work according to goals to stay in shape.. Building a great home gym has its benefits from letting you begin as an amateur to reaching the ultimate trained level, which may turn you into a freak or indeed a gym personality! From a jog on a treadmill to hefty barbell-lifting exercises, the journey is worth undergoing as you grow healthy both physically and mentally. At Fitness Equipments, our range of home gym equipment is designed ...

Figure 1. Response of Cys-TCF to Cys. (A) Time-dependent absorbance spectra of Cys-TCF towards Cys. The absorbance spectra were scanned every 1 min for 12 min. (B) Time-dependent emission spectra of Cys-TCF towards Cys. The inset shows the time-dependent changes of emission at 607 nm. (C) Dose-dependent emission spectra of Cys-TCF towards Cys. (D) Plotting the fold of fluorescence increase (F/F0) at 607 nm (λex = 530 nm) versus the concentrations of Cys. The inset shows F/F0 is linear to the concentrations of Cys in the range of 0.5-10 μmol/L. Data were expressed as mean ± standard deviation (SD) of three experiment ...

Well technically Im whats called a biochemist. Our experiment has nothing to do with solar flux or anything environmental. We are testing a new set of drugs that become activated by direct irradiation by light after cell uptake in drug-resistant bacteria and we are optimizing the parameters of the light emission. It is theorized that peak activity is around 400-500 nm, and unfortunately with these compounds we cant just use UV-VIS spec to determine peak absorbance for activation as it changes once it binds to the cell components. We tried fluorescence microscopy but due to focal points in the cells we were unable to determine the peak absorbance wavelength from that. Essentially you have to think of these things as little spherical lenses which changes the game. There is a lot of theory that unfortunately cant be applied because when you factor in biological activity there is too much going on to stick to the simple methods ...

Our expert will contact you shortly to help you find the right system for your microspectroscopy needs.. For more information please visit our FTIR Spectroscopy Academy.. FTIR Academy. ...

Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; ...

in the centigrade-centimetre system the correction is .0001614 HT (H being the observed height and T the observed temperature). Devices have been invented which determine these corrections mechanically, and hence obviate the necessity of applying the above formula, or of referring to tables in which these corrections for any height of the column and any temperature are given.. The standard temperature of the English yard being 62° and not 32°, it will be found in working out the corrections from the above formula that the temperature of no correction is not 32° but 28.5°. If the scale be engraved on the glass tube, or if the instrument be furnished with a glass scale or with a wooden scale, different corrections are required. These may be worked out from the above formula by substituting for the coefficient of the expansion of brass that of glass, which is assumed to be 0.00000498, or that of wood, which is assumed to be 0. Wood, however, should not be used, its expansion with temperature ...

Animation of a double cone with a family of straight lines as generators in projection, sections of the cone with planes perpendicular to the projection table, the planes being rotated around an axis: hyperbola, parabola, ellipse, circle.

The rather thin outermost layer of the mammalian skin, stratum corneum (SC), is a complex biomembrane which separates the water rich inside of the body from the dry outside. The skin surface can be exposed to rather extreme variations in ambient conditions (e.g. water activity, temperature and pH), with potential effects on the barrier function. Increased understanding of how the barrier is affected by such changes is highly relevant for regulation of transdermal uptake of exogenous chemicals. In the present study we investigate the effect of hydration and the use of a well-known humectant, urea, on skin barrier ultrastructure by means of confocal Raman microspectroscopy. We also perform dynamic vapor sorption (DVS) microbalance measurements to examine the water uptake capacity of SC pretreated with urea. Based on novel Raman images, constructed from 20 spectral maps, we can distinguish large water inclusions within the skin membrane exceeding the size of fully hydrated corneocytes. We show that ...

Special Infrared and Raman Discussion Group meeting Advances in Synchrotron-IR and Raman Microspectroscopy: New Directions in Complementary Approaches Wednesday 28th March 2012 at Diamond Light Source Diamond House, Harwell Science and Innovation Campus - RAL, Chilton-Didcot OX11 0DE, UK Agenda: 09:30 - 10:00 Registration & Coffee 10:00 - 10:10 Welcome & Introduction Gianfelice Cinque & Pavel Matousek 10:10 - 10:50 Chemical Imaging with Synchrotron Infrared Microspectroscopy: From Bones to Brains to Biopolymers Lisa Miller, Photon Sciences Directorate, Brookhaven National Laboratory, USA 10:50 - 11:20 Ultrafast 2D-IR Spectroscopy - Method and Biomolecular Applications Neil Hunt, Department of Physics, University of Strathclyde, UK

Department of Chemistry, UBC Faculty of Science. Vancouver Campus. 2036 Main Mall. Vancouver, BC Canada V6T 1Z1. Tel: 604.822.3266. Fax: 604.822.2847. ...

Department of Chemistry, UBC Faculty of Science. Vancouver Campus. 2036 Main Mall. Vancouver, BC Canada V6T 1Z1. Tel: 604.822.3266. Fax: 604.822.2847. ...

Scanning electron microscopy with energy dispersive X-ray spectrometry (SEMEDS) and Fourier-transform infrared microspectrophotometry (micro-FT-IR) have been widely demonstrated as complementary analytical tools for the identification of complex mixtures and unknown materials. However, there is a gap between the information provided by these two techniques. ...

Identifying and comparing textile fibers is often important in establishing links between suspect and victim or suspect and scene of crime. Techniques used to examine and compare these fibers include microscopy, microspectrophotometry, thin layer chromatography and infrared spectroscopy. Application of these techniques is dependent on the nature of the sample, and therefore the forensic scientist needs to be knowledgeable about fiber production. The three main techniques of microfiber production are conventional spinning, conjugate spinning, and island-in-sea configuration. The article presents details of these processes and of the three main uses for microfibers: as artificial silks, artificial suedes, and high-density material in a variety of garments from underwear and hosiery to coats and all-weather gear. The article describes two cases in which microfibers were transferred and assesses the evidential value. Figures, references ...

Oral epithelial tumour tissue, and cultured cervical epithelial carcinoma cells have been studied using synchrotron infrared microspectroscopy. Mid infrared absorption spectra collected at cellular spatial resolution from within oral tumours were found to be sufficiently distinct, when analysed by principal

This review updates the recent advances and applications of three prominent synchrotron radiation techniques, microprobe X-ray fluorescence spectroscopy/imaging, X-ray absorption spectroscopy, and infrared microspectroscopy, and highlights how these tools are useful to the medicinal chemist. A brief description of the principles of the techniques is given with emphasis on the advantages of using synchrotron radiation-based instrumentation rather than instruments using typical laboratory radiation sources. This review focuses on several recent applications of these techniques to solve inorganic medicinal chemistry problems, focusing on studies of cellular uptake, distribution, and biotransformation of established and potential therapeutic agents. The importance of using these synchrotron-based techniques to assist the development of, or validate the chemistry behind, drug design is discussed.

Color and motion information are thought to be channeled through separate neural pathways, but it remains unclear whether and how these pathways interact to improve motion perception. In insects, such as Drosophila, it has long been believed that motion information is fed exclusively by one spectral class of photoreceptor, so-called R1 to R6 cells; whereas R7 and R8 photoreceptors, which exist in multiple spectral classes, subserve color vision. Here, we report that R7 and R8 also contribute to the motion pathway. By using electrophysiological, optical, and behavioral assays, we found that R7/R8 information converge with and shape the motion pathway output, explaining flies broadly tuned optomotor behavior by its composite responses. Our results demonstrate that inputs from photoreceptors of different spectral sensitivities improve motion discrimination, increasing robustness of perception. ...

Preliminary results of evaluation of progress in chemotherapy for childhood leukemia patients employing Fourier-transform infrared microspectroscopy and cluster … Academic Article ...

The high accuracy, the large number of stars observed and the long period of observation make Kepler ideal for detecting superflares. Studies published in 2012 and 2013 involved 83,000 stars over a period of 500 days (much of the data analysis was carried out with the help of five first-year undergraduates).[2][3][4] The stars were selected from the Kepler Input Catalog to have Teff, the effective temperature, between 5100 and 6000K (the solar value is 5750K) to find stars of similar spectral class to the Sun, and the surface gravity log g , 4.0 to eliminate sub-giants and giants. The spectral classes range from F8 to G8. The integration time was 30 min in the original study. 1547 superflares were found on 279 solar-type stars.The most intense events increased the brightness of the stars by 30% and had an energy of 1036 ergs. White-light flares on the Sun change the brightness by about 0.01%, and the strongest flares have a visible-light energy of about 1032 ergs. (All energies quoted are in the ...

PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

A new model for thermal activation is proposed, with a consequent dependence of the activation rate on λmax. The crucial point is that the statistics of thermal activation is determined by the presence of internal energy in a large number of vibrational modes of the visual pigment molecule. The great discrepancy between photoactivation energies and thermal activation energies as estimated in earlier work then disappears as an analytical artifact. The main conclusion is that thermal and photic activation of visual pigments may follow the same molecular route from a very early stage (isomerization of the chromophore in the native conformation of rhodopsin). Furthermore, the model accurately predicts the correlation between the wavelength of maximum absorbance and the rate of thermal activation observed in the whole set of visual pigments studied ...

Calculations have been performed of the errors introduced in the measurement of peak absorbances by Fourier transform spectroscopy as a result of the finite resolution of the instrument. A Lorentzian line shape and either box-car or triangular apodization has been assumed, For comparison with conventional infrared spectrometers, similar calculations were made assuming a triangular instrument (slit) function. Except for the case of large peak absorbances, the results for triangular apodization are similar to those for the triangular instrument function. Errors become increasingly large as the spectral resolution becomes greater than one-tenth the width of the line at half height. For box-car apodization, the errors are considerably smaller and become large only when resolution becomes greater than line width. Spectra of the $223 1 cm^{-1}$ band of benzonitrile in $CC1_{4}$ solutions have been obtained and generally confirm the results of the calculations. Practical comparisons of box-car and ...

Im having trouble detecting my drug dissolved in ethanol using UV-Vis spectroscopy. The peak absorbance of the drug is at 240 nm while the peak absorbance of the ethanol seems to be around 190 nm. Are these peaks too close to each other to get an accurate measurement? In the wavelength scan of the drug dissolved in solvent, the graph has a higher peak up to 3 AU for ethanol at 190 nm and a lower peak of 1.5 AU at 240 nm for the drug. The peaks, however, are not separated... from the higher ethanol peak at 190 nm, it drops to only around 1.25 AU at 217 nm before going up to the drug peak of 1.5 AU at 240 nm. Ive done a standard and that seems to work out fine. However, when I encapsulate the drug inside polymer and then dissolve that polymer to extract the drug again and detect the amount encapsulated inside, I get a number greater than 100%. So Im detecting more drug than what I put in... would this have to do with how close the peaks are in absorbance and the ethanol peak possibly ...

The present review covers mainly results obtained during the last twelve years.. In 1958 I published in the Handbuch der Physik a general exposition on the role played by molecules in stars and, of course, this included the free radicals. I refer to this general text for details on stellar work prior to 1958. The main topics included in this Handbuch article were the following :. (1) Presence of radicals (in the gaseous phase) in the atmosphres of the earth, sun, planets, comets, stars and interstellar space. Is there a local thermodynamic equilibrium (LTE) or not ?. (2) Information on vibrational and rotational temperatures, chemical compositions, densities, isotopes, physical processes.. (3) Di- and tri-atomic radicals in stars.. (4) The Sun a typical G2V-star; its photosphere, spots and chromosphere ; need for further laboratory measurements (s and probabilities) and high resolution scans.. (5) Importance of bands for spectral classification (spectral classes and absolute magnitudes) ; ...

Buy Givenchy Womens Gray Ruthenium Double Cone Magnetic Earring, starting at $305. Similar products also available. SALE now on!

Halide perovskites are an extremely promising material platform for solar cells and photonic devices. The role of surface carrier recombination-well known to detrimentally affect the performance of devices-is still not well understood for thin samples where the thickness is comparable to or less than the carrier diffusion length. Here, using time-resolved microspectroscopy along with modeling, we ...

Well-dispersed uniform SrMoO4 nanocrystals were synthesized by thermal decomposition of a metal-organic salt in the organic solvent under different temperatures (80, 100, 120, 140, and 160 °C). The smallest diameter of these SrMoO4 nanocrystals is only about 2 nm, which is regarded as the smallest values to date. The UV-vis absorbance spectra present that the larger absorption of our samples is mainly distributed in the visible light region and UV light region. The lowest energy gap is found to be 2.71 eV. Such a small gap is ascribed to the introduction of intermediate energy levels, which are due to the surface defects with decreasing the size of nanostrcutrues. The photoluminescence measurement suggests that all these samples exhibit a board and strong emission band in the range from 500 to 700 nm. Through the deconvolution of the photoluminescence spectra, the emission profiles are found to be associated with three various components (green, yellow, and red). Moreover, the photodegration of ...

Gold NanoUrchin Protein Conjugates. Gold nanourchin protein conjugates are a great alternative to traditional gold protein conjugates if peak absorbance is desired in the 570nm-680nm range. Cytodiagnostics unique gold nanou

The lignin distribution within the cell walls of Gigantochloa levis was studied topochemically by means of TEM and cellular UV microspectrophotometry. The distribution of lignin structural units in different anatomical regions is described and lignification of the tropical bamboo species Gigantochloa levis is compared with that of the temperate bamboo species Phyllostachys viridiglaucescens. Considerable differences were found in cell wall structure between fibres adjacent to the vascular tissue, fibres of free fibre strands and parenchyma cells. The S2 fibre wall in general has a lamellar structure with an increasing lignin content from the centre towards the compound middle lamella. P-coumaric and ferulic acids are more widely distributed in G. levis and their content depends on the anatomical location. The early maturing fibres adjacent to the vascular tissue and at the outer culm wall reveal a maximum absorbance at 280 nm (guaiacyl peak) whereas the late maturing fibres display a shoulder at 310-320

CRAIC Technologies has developed a new solution for the semiconductor industry: the 20/20 XL™ Film Thickness Measurement Tool. The 20/20 XL™ is a microspectrophotometer is designed to non-destructively analyze microscopic areas of very large samples. This system offers the ability to measure the thickness of thin films in both transmission and reflectance.

Anableps anableps remarkable eyes simultaneously sample photons from terrestrial and aquatic habitats. In situ hybridization with six riboprobes demonstrated that A. anableps and the closely related J. onca express at least five cone opsins (sws1, sws2b, rh2-1, rh2-2 and lws), possibly more given the redundancy of our lws probe.. The wavelength of maximal sensitivity for a visual pigment (and consequently the photoreceptor expressing it) can be determined by microspectrophotometry (MSP) or in vitro protein reconstitution [13,14]. By comparing maximal sensitivity data from A. anableps and its relatives obtained using these techniques, we have endeavoured to assign specific opsin genes to cone cell spectral sensitivities: sws1 (356-365 nm, UV), sws2b (405-425 nm, violet), rh2-2 (452-472 nm, blue), rh2-1 (492-539 nm, green) and lws (543-576 nm, yellow) (figure 2a and discussed in supplementary materials). While these represent the value for individual opsin proteins, multiple proteins may be found ...

Symbiotic rhizobia in legumes account for a large portion of nitrogen fixation in the biosphere. Nitrogen fixation is an energy-demanding process requiring tight control of metabolism and redox state. It is of great interest to understand the bacteroid differentiation process and the roles of energy storage molecules, such as glycogen and polyhydroxybutyrate (PHB), in maintaining the Rhizobium-legume symbioses. Traditional biochemical assays for checking phenotypic changes of mutants require a large volume of starting materials, which is difficult for unculturable, terminally differentiated bacteroids. Here we present a label-free technique that allows the identification and characterization of phenotypic changes of bacteria at the single-cell level. This work demonstrates the application of single-cell Raman spectra (SCRS) to differentiate Rhizobium leguminosarum bv. viciae wild-type and mutants under different conditions. We found symbiotically differentiated bacteroids and free-living bacteria

The turtle retina has been used extensively as a model for the study of the neural mechanisms of chromatic processing. Turtle photoreceptor pigments were among the first to be described by microspectrophotometry (Liebman, 1972; Liebman and Granda, 1971; Lipetz and MacNichol, 1982; Lipetz and MacNichol, 1983; Lipetz, 1985; Lipetz and MacNichol, 1990) as were their associated oil droplets (Liebman, 1972; Liebman and Granda, 1971; Fujimoto et al., 1957; Ohtsuka, 1984). Later, intracellular recordings of single cones were performed, and their dynamic properties have also been studied electrophysiologically (Baylor and Fuortes, 1970; Baylor et al., 1971; Fuortes et al., 1973; Granda and Dvorak, 1977; Ohtsuka, 1985a; Ohtsuka, 1985b).. Explorations of the outer retina have revealed four types of horizontal cells according to their response to different wavelengths: a monophasic type with hyperpolarizing responses to all wavelengths (Fuortes and Simon, 1974; Simon, 1973; Yazulla, 1976); two biphasic ...

The strategy used here to describe the spectral sensitivity of human melanopsin has several advantages over alternative methods for defining this feature of visual pigments. The highest resolution descriptions of photopigment spectral sensitivity have traditionally come from direct measures of light absorbance. However, these require high pigment concentrations. In the case of many conventional visual photoreceptors, specialized cellular compartments (e.g. rod outer segments) meet this criterion, allowing microspectrophotometric measures of pigment absorption in its native environment. In other cases, in vitro samples with sufficiently high pigment density for spectrophotometry have been produced by purifying opsin from retinal homogenates, or following heterologous expression in cell culture. Getting reconstituted pigment in vitro has however proved challenging for many opsins and, in the case of mammalian melanopsins has produced absorbance spectra which are inconsistent from study to study ...

Patients undergoing carotid endarterectomy were pretreated with low-dose, oral beta carotene to determine whether the carotenoid content of plaque could be increased in vivo. Beta carotene-treated patients had a 50-fold increase in their plaque beta carotene level from 0.066 to 3.3 micrograms beta carotene/g plaque. Microscopy and microspectrophotometry demonstrated that plaque from beta carotene-treated patients had higher carotenoid levels and higher absorption (450-500 nm) compared with control specimens, but normal media was unaffected. This demonstration of increased preferential absorption by plaque suggests that selective ablation of atherosclerotic plaque may be enhanced by pretreating patients with oral beta carotene. ...

It was anticipated that the combination of two uncorrelated techniques, microcrystalline tests and infrared microspectroscopy, would yield a rapid, cost-effective, and sensitive analytical scheme in which each of the techniques is strengthened by the other. The project succeeded in developing previously unreported microcrystalline tests for several novel psychoactive substances. The combination method was applied against six street psychoactive drug samples, successfully identifying the primary psychoactive substance in each of the samples. The benefits of this analytical scheme are that it is easy to perform, requires microgram quantities of samples, is cost-effective, and is effective as a screening technique for unknown drug samples. For forensic laboratories using the microcrystalline tests for routine identification of traditional drugs such as cocaine and heroin, having a reference library of photomicrographs of other drugs is a useful tool when faced with mixtures. During the 2-year ...

Quantum catches of cones and the Euclidean distance between loci within color space were calculated as described elsewhere (Balkenius & Kelber, 2004). Contrasts in individual receptor types were calculated as Michelson contrast based upon quantum catches (Srinivasan & Lehrer, 1988). Our criteria for isoluminance are (i) that the contrast for double cones is below the minimum contrast threshold of the achromatic contrast sensitivity test (0.098 at 1.42 cycles/degree; Figure 2) and (ii) that this is true even if the absorbance spectrum of the double cones is shifted 10 nm toward shorter or longer wavelengths. The second criterion is important since the principal member of double cones contains a pigmented oil droplet while the accessory member lacks an oil droplet but contains a low concentration of carotenoids in the position where the oil droplet is found in the principal member (Bowmaker et al., 1997). This causes a slight difference in spectral sensitivity between the two double cone members ...

Each scaffold was placed aseptically into a well of a non-tissue culture treated 24-well (in the semiconfocal Raman study) or 48-well plate (in the confocal and fibre-optic Raman study; both Nunc, Thermo Fisher Scientific, Roskilde, Denmark).. In the semiconfocal Raman study, human fibronectin (300 µg ml−1, BD Biosciences), which is known to support cell adhesion [30], was applied to the chondrocyte suspension before seeding onto the scaffolds. The cell-fibronectin suspension, 3 × 106 cells in a final volume of 50 µl for each scaffold, was pipetted onto scaffolds and left to completely adsorb into the porous structure. Samples were left in an incubator at 37°C under a humidified atmosphere of 5% CO2 for 45 min. Subsequently, 2 ml of culture medium was carefully added drop wise. After 7 and 21 days of culture, the samples were studied using Raman microspectroscopy. Chondrocytes of C-28/I2 human immortalized chondrocyte cell line were also seeded on PEOT/PBT scaffolds. C-28/I2 cells were ...

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The formation of biofilms by diverse bacteria isolated from contaminated soil and groundwater on model substrata with different surface properties was assessed in a multifactorial screen. Diverse attachment phenotypes were observed as measured by crystal violet dye retention and confocal laser scanning microscopy (CLSM). Bulk measurements of cell hydrophobicity had little predictive ability in determining whether biofilms would develop on hydrophobic or hydrophilic substrata. Therefore selected pairs of bacteria from the genera Rhodococcus, Pseudomonas and Sphingomonas that exhibited different attachment phenotypes were examined in more detail using CLSM and the lipophilic dye, Nile Red. The association of Rhodococcus sp. cell membranes with lipids was shown to influence the attachment properties of these cells, but this approach was not informative for Pseudomonas and Sphingomonas sp. Confocal Raman Microspectroscopy of Rhodococcus biofilms confirmed the importance of lipids in their formation ...

Gerald McEwen, Yangzhe Wu, Mingjie Tang, Xiaojun Qi, Zhongmiao Xiao, Sherry Baker, Tian Yu, Timothy Gilbertson, Daryll DeWald, and Anhong Zhou, Subcellular Spectroscropic Markers, Topography and Nanomechanics of Human Lung Cancer and Breast Cancer Cells Examined by Combined Confocal Raman Microspectroscopy and Atomic Force Microscopy, Analyst, Vol. 138, No. 3, pp. 787-797, 2013. DOI: 10.1039/c2an36359c. Epub 2012 Nov 27. Work under VPR Research Catalyst (RC) Seed Grant. [PDF ...

We are looking for a highly motivated student to join the bioelectrochemistry and spectroscopy group in the UMR 7140, chimie de la matière complexe at the University of Strasbourg in France.. The project focuses on the study of the reaction mechanism of membrane proteins from the respiratory chain and the identification of inhibitors by means of electrochemical techniques and vibrational spectroscopies. The biosensor will be created by immobilizing the proteins on nanomaterials and the reaction followed by SEIRAS and SERS. We will focus on cytochrome bd oxidase as privileged enzyme target for future antibacterial drugs and a series of inhibitors tested. Similarly the NADH:ubiquinone reductase and the ATPase will be investigated. Further experiments will include the -SCN labeling of these proteins, in order to monitor redox induced conformational changes on the basis of an infrared probe. This international project will be part of the binational PhD college enzyme reactivities and their ...

Birds rely on eyes with high acuity and brilliant colour vision for most of their behaviours, including foraging, mate choice and flight control. Birds are tetrachromats, seeing the world in even more sparkling colours than humans. In addition, their eyes have a number of pecularities the functions och which are not fully understood, such as double cones, coloured oil droplets in all cones types, the pecten and multifocal lenses.

A model developed by Wilmott et al. (J. Fluid Mech., vol. 841, 2018, pp. 310-350) for the advance of a charged oil droplet along a charged capillary pore is considered. The oil droplet is surrounded by an aqueous phase filling the pore, and the model considers a uniformly curved capillary static droplet front plus an aqueous thin film separating the body of the oil droplet from the capillary wall, with these two regions being joined by a transition region. The methodology follows a classical asymptotic approach proposed by Bretherton (J. Fluid Mech., vol. 10, 1961, pp. 166-188) but incorporates additional electro-osmotic effects (specifically an electro-osmotic disjoining tension) due to the charged surfaces. A number of dimensionless parameters control the models behaviour, of which the most important is denoted and represents the ratio between the nominal thickness of the aqueous film (as determined neglecting any electrostatic effects) and the Debye length within the film, which is ...

What is an H-R diagram? Like people - stars grow up and age. But unlike humans, they are all very different in terms of size and weight at their beginnings. Massive stars live short lives and put out a lot of light. Low mass stars are very dim but continue to glow for billions of years. Our Sun is low mass star, but in the end it will do what most stars do - swell up to enormous size. It will turn red, expend its fuel, then expire. Whats left will be a very small white dwarf - glowing mostly by stored up heat. H-R diagrams pull all these factors together - young stars, old stars, bright stars, and dim stars. Lets look at Antares. Its a relatively old, massive star - very bright and destined to end brilliantly. Or Markab - an aging blue dwarf soon to become a red giant. Now look at Deneb. Its a supermassive blue giant shining as brightly as some globular clusters - yet fated to create another supernova remnant in Cygnus within 100 thousand years… Take a look at Enif - a spectral class K ...

The relative abundance and topographical distribution of retinal cone photoreceptors was measured in 19 bird species to identify possible correlations between photoreceptor complement and visual ecolo

What are the types of filtering/washing/drying multifunctional machine/rotary vacuum dryer/vacuum double cone dryer ? Chemical Material Microwave Drying Equipment Massalfa Microwave Manufacturing Service . Get Your Free, Instant price, design review.

Walker, Amanda M.; Yu, Peiqiang; Christensen, Colleen R.; Christensen, David A.; McKinnon, John J. et al. (2009). Fourier Transform Infrared Microspectroscopic Analysis of the Effects of Cereal Type and Variety within a Type of Grain on Structural Makeup in Relation to Rumen Degradation Kinetics. Journal of Agricultural and Food Chemistry 57(15) , 6871-6878. 10.1021/jf901461u. ...

Herein, we report assessments of the kinetics in directional drying of water that contains non-volatile oil droplets, based on direct observations using a confocal microscope. The water was found to evaporate at a constant rate during the initial stage of drying, after which the evaporation rate decreased. T

wst1 blank absorbance problem - posted in Tissue and Cell Culture: Hi everyone, Recently, Ive tried wst1 assay for the first time. After treating the cells with chemical, i added 100 ul fresh DMEM containing 10 ul wst1 and incubated for 3 hours. Ive measured the absorbance in 355-460 interval (this was the closest filter pair to 450 nm -that I could choose in our reader-). Unexpectedly, I got the maximum absorbance values in my blank samples (DMEM+wst1; without cells) and positive controls...

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Die Literatur bestätigt, dass Operationen bei degenerativen Lendenwirbelsäulen(LWS)-Erkrankungen besser sind als ihr Ruf. Getragen wurde diese …