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Infrared Spectroscopy (infrared + spectroscopy)
Kinds of Infrared Spectroscopy Terms modified by Infrared Spectroscopy Selected AbstractsPREDICTION OF TEXTURE IN GREEN ASPARAGUS BY NEAR INFRARED SPECTROSCOPY (NIRS)JOURNAL OF FOOD QUALITY, Issue 4 2002D. PEREZ NIR spectroscopy was used to estimate three textural parameters of green asparagus: maximum cutting force, energy and toughness. An Instron 1140 Texturometer provided reference data. A total of 199 samples from two asparagus varieties (Taxara and UC-157) were used to obtain the calibration models between the reference data and the NIR spectral data. Standard errors of cross validation (SECV) and r2 were (5.73, 0.84) for maximum cutting force, (0.58, 0.66) for toughness, and (0.04, 0.85) for cutting energy. The mathematical models developed as calibration models were tested using independent validation samples (n =20); the resulting standard errors of prediction (SEP) and r2 for the same parameters were (6.73, 0.82), (0.61, 0.57) and (0.04, 0.89), respectively. For toughness, substantially improved r2 (0.85) and SEP (0.36) when four samples exhibiting large residual values were removed. The results indicated that NIRS could accurately predict texture parameters of green asparagus. [source] FOURIER TRANSFORM INFRARED SPECTROSCOPY: A MOLECULAR APPROACH TO AN ORGANISMAL QUESTIONJOURNAL OF PHYCOLOGY, Issue 2 2001Colette Sacksteder No abstract is available for this article. [source] FOURIER TRANSFORM INFRARED SPECTROSCOPY AS A NOVEL TOOL TO INVESTIGATE CHANGES IN INTRACELLULAR MACROMOLECULAR POOLS IN THE MARINE MICROALGA CHAETOCEROS MUELLERII (BACILLARIOPHYCEAE)JOURNAL OF PHYCOLOGY, Issue 2 2001Mario Giordano Fourier Transform Infrared (FT-IR) spectroscopy was used to study carbon allocation patterns in response to changes in nitrogen availability in the diatom Chaetoceros muellerii Lemmerman. The results of the FT-IR measurements were compared with those obtained with traditional chemical methods. The data obtained with both FT-IR and chemical methods showed that nitrogen starvation led to the disappearance of the differences in cell constituents and growth rates existing between cells cultured at either high [NO3,] or high [NH4+]. Irrespective of the nitrogen source supplied before nitrogen starvation, a diversion of carbon away from protein, chlorophyll, and carbohydrates into lipids was observed. Under these conditions, cells that had previously received nitrogen as nitrate appeared to allocate a larger amount of mobilized carbon into lipids than cells that had been cultured in the presence of ammonia. All these changes were reversed by resupplying the cultures with nitrogen. The rate of protein accumulation in the N-replete cells was slower than the rate of decrease under nitrogen starvation. This study demonstrates that the relative proportions of the major macromolecules contained in microalgal cells and their changes in response to external stimuli can be determined rapidly, simultaneously, and inexpensively using FT-IR. The technique proved to be equally reliable to and less labor intensive than more traditional chemical methods. [source] Synthesis, Solution Structure and Biological Activity of Val-Val-Pro-Gln,a Bioactive Elastin PeptideEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2005Caterina Spezzacatena Abstract Val-Val-Pro-Gln (valyl-valyl-prolyl-glutamine) is a small but highly conserved sequence present in all elastins. We describe its synthesis by mixed anhydride solution chemistry as an alternative to solid-phase peptide synthesis (SPPS). The molecular structure of the tetrapeptide in solution was investigated by classical spectroscopy, such as circular dichroism (CD), nuclear magnetic resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). The biological activity of Val-Val-Pro-Gln was evaluated by a bromodeoxyuridine (BrdU) incorporation assay with normal human dermal fibroblasts. This small peptide may play a critical role in control of matrix metabolism through its release from the elastin polypeptide chain during periods of tissue breakdown and remodelling. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Long-term effects of crop rotation and fertilization on soil organic matter compositionEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2007M. Kaiser Summary Long-term effects of crop rotation and fertilization are mostly observed with respect to the amount of soil organic matter (SOM) and measured in terms of soil organic carbon (SOC). In this paper, we analyze the SOM composition of samples from long-term agricultural field experiments at sandy and clayey sites that include complex crop rotations and farm-yard manure applications. The organic matter (OM) composition of the soil samples, OM(Soil), and that of sequentially extracted water, OM(W), and sodium pyrophosphate, OM(PY), soluble fractions was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). The fraction OM(PY) represented between 13 and 34% of SOC, about 10 times that of OM(W). Site specific differences in OM(Soil) composition were larger than those between crop rotations and fertilizer applications. The smaller C=O group content in FTIR spectra of OM(W) compared with OM(PY) suggests that analysis of the more stable OM(PY) fraction is preferable over OM(W) or OM(Soil) for identifying long-term effects, the OM(Soil) and OM(W) fractions and the content of CH groups being less indicative. Farm-yard manure application leads to a more similar content of C=O groups in OM(PY) between crop rotations and fertilizer plots at both sites. Short-term effects from soil tillage or potato harvesting on composition of OM require further studies. [source] Preparation and Characterization of Styrene Butadiene Rubber Based Nanocomposites and Study of their Mechanical PropertiesADVANCED ENGINEERING MATERIALS, Issue 9 2004S. Sadhu Nanocomposites were prepared from styrene butadiene rubber (SBR) having different styrene contents and octadecyl amine modified Na-montmorillonite clay (OC). The modified and the unmodified clays were characterized with the help of X-ray diffraction technique (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM). All these nanocomposites were then subjected to tensile testing. The modified clay-rubber nanocomposites showed improved tensile strength (55% increase) and elongation at break (76% increase) compared to those of the gum vulcanizates. [source] Desorption kinetics of model polar stratospheric cloud films measured using Fourier Transform Infrared Spectroscopy and Temperature-Programmed DesorptionINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 5 2001Birgit G. Koehler This study combines Fourier transform infrared (FTIR) spectroscopy and temperature-programmed desorption to examine the evaporation kinetics of thin films of crystalline nitric acid hydrates, solid amorphous H2O/HNO3 mixtures, H2O,ice, ice coated with HCl, and solid HNO3. IR spectroscopy measured the thickness of each film as it evaporated, either at constant temperature or during a linear temperature ramp (temperature-programmed infrared, TPIR). Simultaneously, a mass spectrometer measured the rate of evaporation directly by monitoring the evolution of the molecules into the gas phase (temperature-programmed desorption, TPD). Both TPIR and TPD data provide a measurement of the desorption rate and yield the activation energy and preexponential factor for desorption. TPD measurements have the advantage of producing many data points but are subject to interference from experimental difficulties such as uneven heating from the edge of a sample and sample-support as well as pumping-speed limitations. TPIR experiments give clean but fewer data points. Evaporation occurred between 170 and 215 K for the various films. Ice evaporates with an activation energy of 12.9 ± 1 kcal/mol and a preexponential factor of 1 × 1032±1.5 molec/cm2 s, in good agreement with the literature. The beta form of nitric acid trihydrate, ,,NAT, has an Edes of 15.6 ± 2 kcal/mol with log A = 34.3 ± 2.3; the alpha form of nitric acid trihydrate, ,,NAT, is around 17.7 ± 3 kcal/mol with log A = 37.2 ± 4. For nitric acid dihydrate, NAD, Edes is 17.3 ± 2 kcal/mol with log A = 35.9 ± 2.6; for nitric acid monohydrate, NAM, Edes is 13 ± 3 kcal/mol with log A = 31.4 ± 3. The ,,NAT converts to ,,NAT during evaporation, and the amorphous solid H2O/HNO3 mixtures crystallize during evaporation. The barrier to evaporation for pure nitric acid is 14.6 ± 3 kcal/mol with log A = 34.4 ± 3. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 295,309, 2001 [source] A new holistic exploratory approach to Systems Biology by Near Infrared Spectroscopy evaluated by chemometrics and data inspectionJOURNAL OF CHEMOMETRICS, Issue 10-11 2007Lars Munck Abstract There is a need for an improved biological and theoretical interpretation of Near Infra-Red Spectral (NIRS) fingerprints from tissues that could contribute with holistic overview to fine-grained detail modelled in Systems Biology. The concept of gene expression in self-organised networks was experimentally tested in a barley endosperm model with molecularly defined and undefined mutants. Surprisingly reproducible gene-specific NIRS fingerprints were observed directly in log1/R MSC pre-treated spectra that could not be accurately represented by destructive mathematical models. A mutant spectrum in an isogenic background represents the physiochemical expression of the gene in the whole network (tissue). The necessary holistic overview that is needed experimentally to introduce Ilya Prigogine's theory on self-organisation in Systems Biology was supplied by defining the spectral phenome. Interval spectral information on genotypes and environment was classified by interval Extended Canonical Variates Analysis (iECVA). Genetic changes in spectra were interpreted by interval Partial Least Squares Regression (iPLSR) correlations to chemical variables. A new pathway regulation was detected. The finely grained ,bottom up' modelling of molecular and chemical data from pathways requires a coarsely grained exploratory ,top down' overview by NIRS to account for the outcome of self-organisation. The amplification of expression from a gene to the phenome (pleiotropy) can now for the first time be quantified as a whole reproducible phenomenological pattern by NIRS and compared to other gene spectra. It explains published findings that transformed respectively mutated genes in genetically modified organisms (GMOs) and cancer patients can be detected unsupervised from tissues by spectroscopy, chemometrics and data inspection. Copyright © 2007 John Wiley & Sons, Ltd. [source] Rapid Analysis of Glucose, Fructose, Sucrose, and Maltose in Honeys from Different Geographic Regions using Fourier Transform Infrared Spectroscopy and Multivariate AnalysisJOURNAL OF FOOD SCIENCE, Issue 2 2010Jun Wang ABSTRACT:, Quantitative analysis of glucose, fructose, sucrose, and maltose in different geographic origin honey samples in the world using the Fourier transform infrared (FTIR) spectroscopy and chemometrics such as partial least squares (PLS) and principal component regression was studied. The calibration series consisted of 45 standard mixtures, which were made up of glucose, fructose, sucrose, and maltose. There were distinct peak variations of all sugar mixtures in the spectral "fingerprint" region between 1500 and 800 cm,1. The calibration model was successfully validated using 7 synthetic blend sets of sugars. The PLS 2nd-derivative model showed the highest degree of prediction accuracy with a highest,R2 value of 0.999. Along with the canonical variate analysis, the calibration model further validated by high-performance liquid chromatography measurements for commercial honey samples demonstrates that FTIR can qualitatively and quantitatively determine the presence of glucose, fructose, sucrose, and maltose in multiple regional honey samples. [source] Rapid Profiling of Swiss Cheese by Attenuated Total Reflectance (ATR) Infrared Spectroscopy and Descriptive Sensory AnalysisJOURNAL OF FOOD SCIENCE, Issue 6 2009N.A. Kocaoglu-Vurma ABSTRACT:, The acceptability of cheese depends largely on the flavor formed during ripening. The flavor profiles of cheeses are complex and region- or manufacturer-specific which have made it challenging to understand the chemistry of flavor development and its correlation with sensory properties. Infrared spectroscopy is an attractive technology for the rapid, sensitive, and high-throughput analysis of foods, providing information related to its composition and conformation of food components from the spectra. Our objectives were to establish infrared spectral profiles to discriminate Swiss cheeses produced by different manufacturers in the United States and to develop predictive models for determination of sensory attributes based on infrared spectra. Fifteen samples from 3 Swiss cheese manufacturers were received and analyzed using attenuated total reflectance infrared spectroscopy (ATR-IR). The spectra were analyzed using soft independent modeling of class analogy (SIMCA) to build a classification model. The cheeses were profiled by a trained sensory panel using descriptive sensory analysis. The relationship between the descriptive sensory scores and ATR-IR spectra was assessed using partial least square regression (PLSR) analysis. SIMCA discriminated the Swiss cheeses based on manufacturer and production region. PLSR analysis generated prediction models with correlation coefficients of validation (rVal) between 0.69 and 0.96 with standard error of cross-validation (SECV) ranging from 0.04 to 0.29. Implementation of rapid infrared analysis by the Swiss cheese industry would help to streamline quality assurance. [source] Stacking interaction study of trans -resveratrol (trans -3,5,4,-trihydroxystilbene) in solution by Nuclear Magnetic Resonance and Fourier Transform Infrared SpectroscopyMAGNETIC RESONANCE IN CHEMISTRY, Issue 7 2008Claudia Bonechi Abstract Interactions between aromatic rings or other unsaturated systems, including ,-stacking and face-to-edge complexes, are the origin of many phenomena in both organic and biological chemistry. It is well known that these interactions play an important role in the stabilization of the stereo-structure of DNA and the tertiary structure of many proteins. Trans -resveratrol (trans -3,5,4,-trihydroxystilbene, trans -RSV) is a phytoalexin found in Vitis sp. and in many other plants and food products and has received much attention because of its possible positive health benefits. In this work, the ,-stacking interaction of trans -RSV was studied by nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. In particular, the proton chemical shift dependence of the RSV concentration in the range 2 × 10,2 , 1 × 10,5M and temperature were analysed. Moreover, the dynamics of the supramolecular aggregates were studied by nuclear spin relaxation data. Copyright © 2008 John Wiley & Sons, Ltd. [source] Protein,Protein Interaction of a Pharaonis Halorhodopsin Mutant Forming a Complex with Pharaonis Halobacterial Transducer Protein II Detected by Fourier-Transform Infrared Spectroscopy,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008Yuji Furutani Pharaonis halorhodopsin (pHR) functions as a light-driven inward chloride ion pump in Natoronomonas pharaonis, while pharaonis phoborhodopsin (ppR; also called pharaonis sensory rhodopsin II, pSRII), is a light sensor for negative phototaxis. ppR forms a 2:2 complex with its cognate transducer protein (pHtrII) through intramembranous hydrogen bonds: Tyr199ppR,Asn74pHtrII and Thr189ppR,Glu43 pHtrII, Ser62pHtrII. It was reported that a pHR mutant (P240T/F250Y), which possesses the hydrogen-bonding sites, impairs its pumping activity upon complexation with pHtrII. In this study, effect of the complexation with pHtrII on the structural changes upon formation of the K, L1 and L2 intermediates of pHR was investigated by use of Fourier-transform infrared spectroscopy. The vibrational changes of Tyr250pHR and Asn74pHtrII were detected for the L1 and L2 intermediates, supporting that Tyr250pHR forms a hydrogen bond with Asn74pHtrII as similarly to Tyr199ppR. The conformational changes of the retinal chromophore were never affected by complexation with pHtrII, but amide-I vibrations were clearly different in the absence and presence of pHtrII. The molecular environment around Asp156pHR in helix D is also slightly affected. These additional structural changes are probably related to blocking of translocation of a chloride ion from the extracellular to the cytoplasmic side during the photocycle. [source] Mechanical and tribological characterization of CNx films deposited by d.c. magnetron sputteringPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2007L. Ipaz Abstract Carbon nitride (CNx) thin films were deposited onto silicon and steel substrates at 400 °C from a carbon target by d.c. magnetron sputtering system. The composition, structural, and mechanical properties of deposited films were investigated as a function of argon/nitrogen concentration and sputtering power, by means of Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy (RS), and nanoindentation. The EDS and Elastic Forward Analisys Analysis (EFA) showed that the nitrogen concentration in the CNx deposited films varied between 16% and 28% at depending on nitrogen concentrations in argon/nitrogen gas mixture, and deposition power. FTIR analysis indicated the presence of 2266 and 2278 cm,1 stretching peaks associated with CN triple bonds of nitriles and isocyanides, 1640 cm,1 and 1545 cm,1 associated with the C=C and C=N bonds. The thickness of the CNx deposited films varied between 0.4 and 0.8 µm at different sputtering powers. The hardness and Young's modulus were investigated by depth sensing nanoindentation method. The obtained hardness and Young's modulus increased from 4 to 17 GPa, and from 50 to 170 GPa, respectively; when the nitrogen content in the deposited films diminished between 28 and 12%. On the other hand, the friction and wear tests were done using a pin-on-disc tribometer. The friction tests showed values of 0.05 and 0.4 in dry air and humid atmosphere; respectively. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Near Infrared Spectroscopy as a Tool for the Determination of Eumelanin in Human HairPIGMENT CELL & MELANOMA RESEARCH, Issue 4 2004Marina Zoccola Eumelanins are brown-black pigments present in the hair and in the epidermis which are acknowledged as protection factors against cell damage caused by ultraviolet radiation. The quantity of eumelanin present in hair has recently been put forward as a means of identifying subjects with a higher risk of skin tumours. For epidemiological studies, chromatographic methods of determining pyrrole-2,3,5-tricarboxylic acid (PTCA; the principal marker of eumelanin) are long, laborious and unsuitable for screening large populations. We suggest near infrared (NIR) spectroscopy as an alternative method of analysing eumelanin in hair samples. PCTA was determined on 93 samples of hair by means of oxidizing with hydrogen peroxide in a basic environment followed by chromatographic separation. The same 93 samples were then subjected to NIR spectrophotometric analysis. The spectra were obtained in reflectance mode on hair samples which had not undergone any preliminary treatment, but had simply been pressed and placed on the measuring window of the spectrophotometer. The PTCA values obtained by means of HPLC were correlated with the near infrared spectrum of the respective samples. A correlation between the PTCA values obtained by means of HPLC and the PTCA values obtained from an analysis of the spectra was obtained using the principal component regression (PCR) algorithm. The correlation obtained has a coefficient of regression (R2) of 0.89 and a standard error of prediction (SEP) of 13.8 for a mean value of 108.6 ng PTCA/mg hair. Some considerations about the accuracy of the obtained correlation and the main sources of error are made and some validation results are shown. [source] Improvement of the interfacial compatibility between sugar cane bagasse fibers and polystyrene for compositesPOLYMER COMPOSITES, Issue 2 2004Edgar García-Hernández Sugar cane bagasse fibers were modified by surface treatments using either physical or chemical methods in order to improve their adhesion to polystyrene matrices. The surface treatment methods used were alkaline treatment, treatment with silane coupling agents, physical coating with polystyrene and grafting of polystyrene with and without crosslinker. Fiber modifications were monitored by Fourier Transform Infrared Spectroscopy (FTIR), Differential Thermal Analysis coupled with Thermogravimetric Analysis (DTA-TGA) and Scanning Electron Microscopy (SEM). On the other hand, the improvement of the adhesion between sugar cane modified fibers and polystyrene was assessed by micromechanical pull-out and by macromechanical Iosipescu tests. It was found, from Interfacial Shear Strength values (IFSS), that substantial improvements in fiber-matrix compatibility were achieved. According to micro- and macromechanical test results, the IFSS increased for all treated fibers as compared to non-treated fibers. Particularly, both the coating the fibers or grafting with polystyrene using crosslinker resulted in substantial adhesion improvement to the polystyrene matrix in comparison with the non-treated fibers and fibers treated by alkaline and silane methods only. Polym. Compos. 25:134,145, 2004. © 2004 Society of Plastics Engineers. [source] Comparative study of continuous-power and pulsed-power microwave curing of epoxy resinsPOLYMER ENGINEERING & SCIENCE, Issue 10 2000Bao Fu Three epoxy reaction systems, diglycidyl ether of bisphenol A (DGEBA) with curing agents meta phenylene diamine (mPDA), diaminodiphenyl methane (DDM), and diaminodiphenyl sulfone (DDS), were cured with both pulsed-power and continuous-power microwave curing systems. Isothermal curing was conducted at three different temperatures for each reaction system with both pulsed-power and continuous-power microwave curing systems. Extent of cure was measured with Fourier Transform Infrared Spectroscopy (FTIR). The temperature characteristics, incident and reflected power patterns, and the reaction rates were compared between the two curing approaches. The incident power and reflected power of both curing processes were observed to reveal reaction status. Continuous-power microwave curing produced noticeably higher reaction rates than pulsed-power microwave curing. [source] Synthesis and photopolymerization kinetics of multifunctional aromatic urethane acrylates containing tertiary amine groupPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2009Jing Zhang Abstract Two multifunctional aromatic urethane acrylates, based on 2, 4-toluene diisocyanate (2, 4-TDI), , -hydroxyethyl arcylate (HEA), and synthetic multifunctional hydroxyl compounds, were synthesized by classical condensation reaction. FTIR was used to monitor the process of the reaction. The photopolymerization kinetics of the urethane acrylates with different photoinitiators was studied by Real-Time Infrared Spectroscopy. The results indicated that different from the commercial urethane acrylate CN 975, the synthetic multifunctional urethane acrylates could be efficiently initiated by BP without the addition of any co-initiators as they have tertiary amine structures. Copyright © 2008 John Wiley & Sons, Ltd. [source] Biocatalytic hydrogels by template polymerizationPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2008H. El-Sherif Abstract Novel ionizable hydrogels were prepared from poly(acrylic acid) and dimethylaminoethyl methacrylate monomer employing template polymerization technique as an alternative to traditional physical and chemical crosslinking. The mode of interaction, as proved by Fourier Transform Infrared Spectroscopy (FTIR), was multiple H-bonding between the tertiary amino group of the monomer and the carboxylic groups of the polymer. The hydrogels represented suitable matrices for enzyme immobilization. The effect of varying the polymer,monomer molar ratio on the swelling kinetics and parameters was investigated. The dynamic swelling isotherm exhibited a Fickian mode of penetrant sorption and a plateau that increases with the amino group content. A polymer complex of molar ratio (polymer:monomer) 0.5:0.8 had a weight swelling ratio of 10 and 7 at pHs 3 and 8, respectively. The proven pH sensitivity together with the amphoteric character of these hydrogels make them good candidates for another bioapplication such as oral delivery systems of therapeutic peptides and proteins. The structural integrity of the hydrogels was proved by their swelling reversibility. , -Galactosidase, as an acidic model enzyme, was immobilized covalently on the synthesized hydrogels. The maximum enzyme velocity (Vmax) was enhanced to 19,µmol/min/mg, for polycomplex of molar ratio 0.5:0.8, compared with 3.2,µmol/min/mg for the free enzyme. Copyright © 2008 John Wiley & Sons, Ltd. [source] Room-Temperature Infrared Spectroscopy Combined with Mass Spectrometry Distinguishes Gas-Phase Protein Isomers,ANGEWANDTE CHEMIE, Issue 44 2009Eva Fung Dr. IR-Differenzspektren von Proteinen in der Gasphase bei Raumtemperatur werden durch eine Kombination aus IR-Multiphotonendissoziation (IRMPD) und FT-Ionencyclotron-Resonanz-Massenspektrometrie erhalten. Dieser neue Ansatz liefert unverwechselbare Spektren für all- L - und mono- D -substituierte Isomere des Proteins Trp-cage (siehe Differenzspektrum) und vermeidet so eine Proteinentfaltung während der IR-Bestrahlung, die übliche IRMPD-Messungen stören kann. [source] Comparison of Spiculogenesis in in Vitro ADCP-primmorph and Explants Culture of Marine Sponge Hymeniacidon perleve with 3-TMOSPU SupplementationBIOTECHNOLOGY PROGRESS, Issue 3 2007Xupeng Cao This study aims to test the feasibility of introducing functional chemical groups into biogenic silica spicules by examining the effect of supplementing a silican coupler [3-(trimethoxysilyl)propyl]urea (3-TMOSPU) as silica source in the cultures of archaeocytes-dominant-cell-population (ADCP) primmorphs and explants of the marine sponge Hymeniacidon perleve. Analysis by Fourier Transform Infrared Spectroscopy (FT-IR) confirmed that the organic group in 3-TMOSPU was introduced into silica spicules. By comparing ADCP-primmorph cultures when supplemented with Na2SiO3, 3-TMOSPU supplementation showed no notable effect on the primmorphs development and cell locomotion behaviors. A decline in silicatein expression quantified by real-time RT-PCR was, however, observed during spiculogenesis. The decline was slower for the 3-TMOSPU group whereas significantly fewer spicules were formed. When sponge papillae explants were cultured, 3-TMOSPU supplementation had no negative effect on sponge growth but inhibited the growth biofouling of the diatom Nitzschia closterium. By monitoring the detectable Si concentration, it seemed that 3-TMOSPU was converted by the sponge and its conversion was related to spiculogenesis. Analysis of spicule dimensional changes indicated that the inhibition of spiculogenesis by 3-TMOSPU supplementation was less in ADCP-primmorphs culture due to lower 3-TMOSPU/detectable Si ratio in the media. [source] Character of the Si and Al Phases in Coal Gangue and Its AshACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 6 2009WANG Lihua Abstract: Analysis of the Si and Al phases in coal gangue fuel and its ash is important for use of coal gangue ashes. A comprehensive study by theoretical and experimental analyses with differential thermal analysis, X-ray diffraction and Infrared Spectroscopy has been made in the present article to explore the diagram of the Si and Al phases in coal gangue fuel and its ashes. It is found that kaolinite and quartz are the main phases in coal gangue fuel. The ratio of moles Al2O3to SiO2 (i.e., Al2O3 (mole)/ SiO2 (mole)) is usually no more than 0.5 in most coal gangue fuel and its ashes. The kaolinit at about 984°C releases a large quantity of SiO2, which makes calcine coal gangue more active than coal gangue itself. The relationship between the ratio Al2O3 (mole)/SiO2 (mole) and the components of coal gangue ash is analyzed, resulting in a formula to calculate the quantity of each phase. Applying the formula to the testing samples from an electric plant in north China supports the above conclusions. [source] ChemInform Abstract: Identification of Conical Structures in Small Aluminum Oxide Clusters: Infrared Spectroscopy of (Al2O3)1-4(AlO)+.CHEMINFORM, Issue 6 2009Gabriele Santambrogio Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: High-Resolution Infrared Spectroscopy of trans- and cis-H18ON18O: Equilibrium Structures of the Nitrous Acid Isomers.CHEMINFORM, Issue 5 2009V. Sironneau J. Orphal Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Infrared Spectroscopy of Water Cluster Anions, (H2O)n=3-24 - in the HOH Bending Region: Persistence of the Double H-Bond Acceptor (AA) Water Molecule in the Excess Electron Binding Site of the Class I Isomers.CHEMINFORM, Issue 35 2006Joseph R. Roscioli Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Thermal Stability of Dehydrophenylalanine-Containing Model Peptides as Probed by Infrared Spectroscopy: a Case Study of an , -Helical and a 310 -Helical PeptideCHEMISTRY & BIODIVERSITY, Issue 3 2006Alka Gupta Abstract The temperature-dependent secondary-structural changes in the two known helical model peptides Boc-Val-,Phe-Ala-Leu-Gly-OMe (1; , -helical) and Boc-Leu-Phe-Ala-,Phe-Leu-OMe (2; 310 -helical), which both comprise a single dehydrophenylalanine (,Phe) residue, were investigated by means of FT-IR spectroscopy (peptide film on KBr). Both the first-order and the better-resolved second-order derivative IR spectra of 1 and 2 were analyzed. The ,(NH) (3240,3340,cm,1), the Amide-I (1600,1700,cm,1), and the Amide-II (1510,1580,cm,1) regions of 1 and 2 showed significant differences in thermal-denaturation experiments (22°,144°), with the 310 -helical peptide (2) being considerably more stable. This observation was rationalized by different patterns and strengths of intramolecular H-bonds, and was qualitatively related to the different geometries of the peptides. Also, a fair degree of residual secondary-structural elements were found even in the ,denatured' states above 104° (1) or 134° (2). [source] Hydration of the Calcium Dication: Direct Evidence for Second Shell Formation from Infrared SpectroscopyCHEMPHYSCHEM, Issue 15 2007Matthew F. Bush Abstract Infrared laser action spectroscopy in a Fourier-transform ion cyclotron resonance mass spectrometer is used in conjunction with ab initio calculations to investigate doubly charged, hydrated clusters of calcium formed by electrospray ionization. Six water molecules coordinate directly to the calcium dication, whereas the seventh water molecule is incorporated into a second solvation shell. Spectral features indicate the presence of multiple structures of Ca(H2O)72+ in which outer-shell water molecules accept either one (single acceptor) or two (double acceptor) hydrogen bonds from inner-shell water molecules. Double-acceptor water molecules are predominately observed in the second solvent shells of clusters containing eight or nine water molecules. Increased hydration results in spectroscopic signatures consistent with additional second-shell water molecules, particularly the appearance of inner-shell water molecules that donate two hydrogen bonds (double donor) to the second solvent shell. This is the first reported use of infrared spectroscopy to investigate shell structure of a hydrated multiply charged cation in the gas phase and illustrates the effectiveness of this method to probe the structures of hydrated ions. [source] Impact of surface thermodynamics on bacterial transportENVIRONMENTAL MICROBIOLOGY, Issue 4 2001Gang Chen Microbial surface thermodynamics correlated with bacterial transport in saturated porous media. The surface thermodynamics was characterized by contact-angle measurement and the wicking method, which was related to surface free energies of Lifshitz,van der Waals interaction, Lewis acid,base interaction, and electrostatic interaction between the bacteria and the medium matrix. Transport of three different strains of bacteria present at three physiological states was measured in columns of silica gel and sand from the Canadian River Alluvium (Norman, OK, USA). Microorganisms in stationary state had the highest deposit on solid matrix, compared with logarithmic and decay states. The deposition correlated with the total surface free energy (,G132TOT) and the differences in ,G132TOT were mainly controlled by the Lewis acid,base interaction. Infrared spectroscopy showed that the increased deposition correlated with an increase in the hydrogen-bonding functional groups on the cell surfaces. [source] Synthesis and characterization of diphenylmethyltin(IV) mono-, di-, and trichloroacetateHETEROATOM CHEMISTRY, Issue 1 2003Mostafa Mohammadpour Amini Diphenylmethyltin(IV) mono-, di-, and trichloroacetate have been synthesized and characterized by infrared, 1H, 13C, 119Sn NMR, and mass spectroscopy. Infrared spectroscopy indicates that the prepared organotin carboxylates possess chain polymer structures. NMR data show that the mono- and dichloro derivatives do not retain the solid state structure in solution. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:18,22, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10059 [source] Preparation and fluorescence properties of poly(o -methyl-acrylamideyl-benzoic acid)-ZnS compositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Qing-Feng Xu Abstract Poly(o -methyl-acrylamideyl-benzoic acid)-ZnS (P(o -MAABA)-ZnS) nanocomposites have been prepared and characterized. The resultant P(o -MAABA)-ZnS nanocomposites in solution show two emissions in the purple-light area (370 nm) and in the blue-light area (425 nm), which are assigned to the polymer and ZnS nanoparticles, respectively. The coordination between the polymer and Zn2+ and the surface chemical composition has been studied by Infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The particle size of ZnS nanoparticles was homogeneous and the average size was 3.8 nm, which were characterized by UV absorption spectrum and X-ray Diffraction. The P(o -MAABA)-ZnS composites displays good film formability and the films also show two emissions in 370 and 425 nm. After doped with Tb3+, there was effective energy transfer from ZnS nanoparticles to Tb3+. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Preparation and sorption studies of ,-cyclodextrin/epichlorohydrin copolymersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Dawn Y. Pratt Abstract ,-Cyclodextrin (,-CD) copolymer materials were synthesized by reacting different mole ratios (1 : 15, 1 : 25 and 1 : 35) of ,-CD with epichlorohydrin (EP). The products were characterized using N2 porosimetry, Fourier Transform Infrared spectroscopy, 13C CP-MAS NMR spectroscopy, thermogravimetry analysis, elemental (C and H) analysis, and scanning electron microscopy. The sorption properties in aqueous solution were studied using p-nitrophenol (PNP) with UV,Vis spectrophotometry. Sorption isotherms were obtained at pH 4.6 and three temperatures (22, 35, and 45°C) and at pH 10.3 at 22°C. The isotherms were analyzed using the BET isotherm model and the sorption parameters provided estimates of the surface area, sorption capacity, and isosteric heats of sorption for each polymeric material. The estimated surface areas are as follows: 58.2, 52.1, and 90.1 m2/g at pH 4.6. At pH 10.3, the estimated surface areas are 44.2, 40.5, and 58.5 m2/g, respectively. The removal efficiency of PNP by the polymeric materials ranged between 4.5 and 58% for the conditions investigated whereas the isosteric heats ranged between ,24.5 and ,13.6 kJ/mol. Removal efficiencies were concluded to strongly depend on the sorption conditions such as pH, temperature, and the relative amounts of sorbent and dye in aqueous solution. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] | ||||||||||||||||||||||||||||||||||||||||