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1.
Congenital cystic adenomatoid malformations (CCAMs) are benign masses of non-functional lung tissue developing from an overgrowth of the terminal bronchioles with subsequent suppressing of alveolar growth. For the first time CCAMs are studied by Raman mapping and Fourier transform infrared (FTIR) imaging. Both vibrational spectroscopic methods are able to analyze the biochemical composition of tissues and their pathological changes at the molecular level. Cryosections were prepared on calcium fluoride substrates from CCAMs and from normal lung tissue of two infant patients who underwent surgery. Raman maps were collected at a step size of 100 microm in order to assess the whole tissue section and at a smaller step size of 10 microm in order to resolve details in selected areas. FTIR images were collected in the macroscopic and microscopic modes. Data sets were segmented by cluster analysis and the mean spectra of each cluster were compared. At low lateral resolution a lower red blood cell content and higher lipid content were found in CCAMs than in normal lung tissue. At higher lateral resolution, accumulations of lipids and glycogen were identified in CCAMs. The lipid aggregates contain a high concentration of phosphatidylcholine. It is discussed how the combined application of Raman mapping and FTIR imaging might improve the differential diagnosis of lung malformations and how both modalities might be applied to other bioanalytical and biomedical problems in the future. 相似文献
2.
Elucidation of functional groups on gram-positive and gram-negative bacterial surfaces using infrared spectroscopy 总被引:1,自引:0,他引:1
Jiang W Saxena A Song B Ward BB Beveridge TJ Myneni SC 《Langmuir : the ACS journal of surfaces and colloids》2004,20(26):11433-11442
Surface functional group chemistry of intact Gram-positive and Gram-negative bacterial cells and their isolated cell walls was examined as a function of pH, growth phase, and growth media (for intact cells only) using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Infrared spectra of aqueous model organic molecules, representatives of the common functional groups found in bacterial cell walls (i.e., hydroxyl, carboxyl, phosphoryl, and amide groups), were also examined in order to assist the interpretation of the infrared spectra of bacterial samples. The surface sensitivity of the ATR-FTIR spectroscopic technique was evaluated using diatom cells, which possess a several-nanometers-thick layer of glycoprotein on their silica shells. The ATR-FTIR spectra of bacterial surfaces exhibit carboxyl, amide, phosphate, and carbohydrate related features, and these are identical for both Gram-positive and Gram-negative cells. These results provide direct evidence to the previously held conviction that the negative charge of bacterial surfaces is derived from the deprotonation of both carboxylates and phosphates. Variation in solution pH has only a minor effect on the secondary structure of the cell wall proteins. The cell surface functional group chemistry is altered neither by the growth phase nor by the growth medium of bacteria. This study reveals the universality of the functional group chemistry of bacterial cell surfaces. 相似文献
3.
Miller LM Wang Q Smith RJ Zhong H Elliott D Warren J 《Analytical and bioanalytical chemistry》2007,387(5):1705-1715
Many disease processes involve alterations in the chemical makeup of tissue. Synchrotron-based infrared (IR) and X-ray fluorescence
(XRF) microscopes are becoming increasingly popular tools for imaging the organic and trace metal compositions of biological
materials, respectively, without the need for extrinsic labels or stains. Fourier transform infrared microspectroscopy (FTIRM)
provides chemical information on the organic components of a material at a diffraction-limited spatial resolution of 2–10 μm
in the mid-infrared region. The synchrotron X-ray fluorescence (SXRF) microprobe is a complementary technique used to probe
trace element content in the same systems with a similar spatial resolution. However to be most beneficial, it is important
to combine the results from both imaging techniques on a single sample, which requires precise overlap of the IR and X-ray
images. In this work, we have developed a sample substrate containing a gold grid pattern on its surface, which can be imaged
with both the IR and X-ray microscopes. The substrate consists of a low trace element glass slide that has a gold grid patterned
on its surface, where the major and minor parts of the grid contain 25 and 12 nm gold, respectively. This grid pattern can
be imaged with the IR microscope because the reflectivity of gold differs as a function of thickness. The pattern can also
be imaged with the SXRF microprobe because the Au fluorescence intensity changes with gold thickness. The tissue sample is
placed on top of the patterned substrate. The grid pattern’s IR reflectivity image and the gold SXRF image are used as fiducial
markers for spatially overlapping the IR and SXRF images from the tissue. Results show that IR and X-ray images can be correlated
precisely, with a spatial resolution of less than one pixel (i.e., 2–3 microns). The development of this new tool will be
presented along with applications to paraffin-embedded metalloprotein crystals, Alzheimer’s disease, and hair composition. 相似文献
4.
气-液界面有序介孔SiO2无机膜的仿生合成 总被引:2,自引:0,他引:2
早在几百万年以前,自然界就通过生物矿化过程形成了结构高度有序的有机/无机复合材料,如哺乳动物的牙床、骨骼以及贝壳珍珠层等[1]。随着对天然生物材料生物矿化过程研究的逐渐深入,材料研究者从中得到极为重要的启示:先形成有机物自组装体,无机先驱物在自组装聚集体与溶液相的界面处发生化学反应,在有机自组装体的模板作用下,形成有机/无机复合体,再将有机模板去除即可得到具有一定形状与组织结构的无机材料。这种模仿生物矿化中无机物在有机物调制下形成过程的材料合成,称为仿生合成(biomimetic synthesis)[2]。仿生合成过程中,通过选择有… 相似文献
5.
Edith Joseph Silvia Prati Giorgia Sciutto Marcella Ioele Paola Santopadre Rocco Mazzeo 《Analytical and bioanalytical chemistry》2010,396(2):899-910
Different Fourier transform infrared microspectroscopic techniques, using attenuated total reflection (ATR) mode and single-element
mercury–cadmium–telluride (MCT) detector (mapping) or multielement MCT detector (raster scanning), are compared with each
other for the characterisation of inorganic compounds and organic substances in paint cross sections. All measurements have
been performed on paint cross sections embedded in potassium bromide, a transparent salt in the mid-infrared region, in order
to better identify the organic materials without the interference of the usual embedding resin. The limitations and advantages
of the different techniques are presented in terms of spatial resolution, data quality and chemical information achieved.
For all techniques, the chemical information obtained is found to be nearly identical. However, ATR mapping performed with
a recently developed instrumentation shows the best results in terms of spectral quality and spatial resolution. In fact,
thin organic layers (∼10 μm) have been not only identified but also accurately located. This paper also highlights the recent
introduction of multielement detectors, which may represent a good compromise between mapping and imaging systems. 相似文献
6.
Cristiana Figus Masahide Takahashi Maria Casula Plinio Innocenzi 《Journal of Sol-Gel Science and Technology》2011,60(3):275-282
Hybrid organic–inorganic films containing layered organosilicate nanocrystals have been obtained through self-organization
from aqueous precursor sols containing 3-glycidoxypropyltrimethoxysilane. Diethoxydiphenylsilane has been added, in different
amounts, to the precursor sol containing 3-glycidoxypropyltrimethoxysilane to prepare hybrid films with the ordered nanostructures.
The effect of aging time of the precursor sol has been studied preparing different samples from sols aged up to 8 days; the
formation of crystalline layered films has been observed in the samples obtained from sols of higher aging time. The hybrid
films have been characterized by gracing incidence X-ray diffraction, Raman and Fourier transform infrared spectroscopy, transmission
electron microscopy and UV–Vis spectroscopy. The change of the surface contact angle as a function of sol aging time and composition
has been also measured. The capability of the films to be used in devices through lithographic techniques has been tested
by writing the films with direct exposition to deep X-ray lithography and soft lithography with micromolds; patterns of different
geometries with a thickness up to 100 μm have been obtained. 相似文献
7.
Mingjie Tang Gerald D. McEwen Yangzhe Wu Charles D. Miller Anhong Zhou 《Analytical and bioanalytical chemistry》2013,405(5):1577-1591
The molecular composition of mycobacteria and Gram-negative bacteria cell walls is structurally different. In this work, Raman microspectroscopy was applied to discriminate mycobacteria and Gram-negative bacteria by assessing specific characteristic spectral features. Analysis of Raman spectra indicated that mycobacteria and Gram-negative bacteria exhibit different spectral patterns under our experimental conditions due to their different biochemical components. Fourier transform infrared (FTIR) spectroscopy, as a supplementary vibrational spectroscopy, was also applied to analyze the biochemical composition of the representative bacterial strains. As for co-cultured bacterial mixtures, the distribution of individual cell types was obtained by quantitative analysis of Raman and FTIR spectral images and the spectral contribution from each cell type was distinguished by direct classical least squares analysis. Coupled atomic force microscopy (AFM) and Raman microspectroscopy realized simultaneous measurements of topography and spectral images for the same sampled surface. This work demonstrated the feasibility of utilizing a combined Raman microspectroscopy, FTIR, and AFM techniques to effectively characterize spectroscopic fingerprints from bacterial Gram types and mixtures. Figure
AFM deflection images, Raman spectra, SEM images, and FTIR of Mycobacterium sp. KMS 相似文献
8.
Gerald Steiner Valdas Sablinskas Wolfgang Seidel Reiner Salzer 《Analytical and bioanalytical chemistry》2009,395(6):1641-1650
Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) is a very sensitive technique to characterize
the degree of molecular ordering in thin films on metallic surfaces. This is the first report of the coupling of a PM-IRRAS
microscope to a free electron laser (FEL), a light source of highest brilliance. Some FELs emit in the infrared region and
permit the mapping of molecular properties at high lateral resolution. We studied the molecular orientation of octadecanephosphonic
acid (OPA) attached to a gold surface with microstructured aluminum oxide islands on the gold. The spatial resolution achieved
is 12 μm which corresponds to the diffraction limit of the infrared light used in this study. This is a substantial improvement
compared to previous studies using a PM-IRRA accessory together with a commercial Fourier transform infrared spectrometer,
where the lateral resolution is noise-limited rather than diffraction-limited. The spectral maps reveal that OPA is preferably
attached to the aluminum oxide islands via the bidentate binding mode whereas the tridentate mode is dominating in case of
OPA attached to the gold areas. 相似文献
9.
Jalal Poostforooshan Alireza Badiei Gholamali Farzi Hassan Goldooz Alfred P. Weber 《Chemical Papers》2017,71(10):1887-1894
In this work, for the first time, control over the position of maximum emission peak for fluorophore, using embedded tris(8-hydroxyquinoline) aluminum (AlQ3) complexes into different types of host materials, can be achieved. Moreover, the environmental and concentration effects on luminescent properties were studied. In this regard, different concentrations of AlQ3 were embedded into the poly(methyl methacrylate-co-butyl acrylate) (PMMA-co-PBuA) nanoparticles as organic host materials by emulsion polymerization. It is established that the dilution of AlQ3 in the polymer matrix leads to blue-shift of the luminescence maximum up to 0.32 eV compared to pure AlQ3. Moreover, AlQ3 was embedded in SBA-15 type mesoporous silica as an inorganic host material by physical adsorption. Finally, this functionalized mesoporous silica was incorporated into PMMA-co-PBuA transparent matrix by blending method to obtain Co-Poly-AlQ3-SBA-15 as organic–inorganic composite material. It was found that there is no significant wavelength shift on the maximum emission peak of the organic–inorganic composite at various concentrations of AlQ3-SBA-15. The prepared materials were characterized by powder X-ray diffraction (XRD), N2 adsorption–desorption, NMR, Fourier transform infrared (FT-IR), dynamic light scattering (DLS), scanning electron microscopy (SEM) and fluorescence spectra. 相似文献
10.
Changjie Chen Guicui Chen Xin Li Hongyun Guo Guohe Wang 《Cellulose (London, England)》2017,24(4):1611-1620
Bleached palm fiber without lignin, alkalized palm fiber without hemicelluloses and raw windmill palm fiber were prepared. Then, the chemical composition and the mechanical properties of the windmill palm fiber were investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy and Raman microscopy were employed to characterize the structure and chemical composition. A universal material tester, nanoindentation and dynamic mechanical analysis were used to study the mechanical property of these samples. According to the results, bleach treatment removed most of the silica bodies as well as the lignin, smoothed the fiber surfaces and increased the hollowness to 50%. Alkali treatment removed most of the hemicelluloses, increased the surface roughness, and reduced the hollowness to 28%. Alkalized fibers have the highest tensile strength, elongation at break and elastic modulus, with values of 119.37 ± 27.21 MPa, 30.58 ± 5.87% and 10.75 ± 4.30 GPa, respectively. The raw material without treatment has the highest stiffness, while the alkalized samples are the most flexible fibers and sensitive to temperature. 相似文献
11.
Chin‐Lung Chiang Chen‐Chi M. Ma Dai‐Lin Wu Hsu‐Chiang Kuan 《Journal of polymer science. Part A, Polymer chemistry》2003,41(7):905-913
This article describes the preparation of novolac‐type phenolic resin/silica hybrid organic–inorganic nanocomposite, with a sol–gel process. The coupling agent was used to improve the interface between the organic and inorganic phases. The effect of the structure of the nanocomposite on its physical and chemical properties is discussed. The coupling agent reacts with the resin to form covalent bonds. The structure of the modified hybrid nanocomposites was identified with a Fourier transform infrared spectroscope. The silica network was characterized by nuclear magnetic resonance imaging (29Si NMR). Results revealed that Q4 (tetrasubstituted) and T3 (trisubstituted) are the dominant microstructures. The size of the silica in the phenolic resin was characterized with a scanning electron microscope. The size of the particles of inorganic silica in the modified system was less than 100 nm. The nanocomposite exhibited good transparency. Moreover, the thermal and mechanical properties exhibited significant improvement. The modified hybrid composite exhibited favorable thermal properties. The temperature at which a weight loss of 5% occurred increased from 281 to 350 °C. The flexural strength increased by 6–30%. The limiting oxygen index of the nanocomposite reached 37, and the Underwriters Laboratory test was 94V‐0. Consequently, these materials possess excellent flame‐retardant properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 905–913, 2003 相似文献
12.
13.
TP Wrobel KM Marzec K Majzner K Kochan M Bartus S Chlopicki M Baranska 《The Analyst》2012,137(18):4135-4139
Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) with the use of a slide-on germanium accessory followed by chemometric analysis allowed for providing meaningful information about the biochemical composition of a single endothelial cell. In this work, the methodology of the ATR-FTIR measurements of dried cells and dried cells immersed in water solution is presented. The contact of the cell and Ge crystal was set up manually and monitored through the integration of the amide I band. Additionally, the cell imaging in transreflection mode was tested, but the spectral differences between sub-cellular structures were not prominent in the registered spectra. It has been shown that the ATR-FTIR method gives better results due to the increased spatial resolution and S/R ratio as well as small contribution of the optical artifacts. 相似文献
14.
K. D. Girase D. K. Sawant H. M. Patil D. S. Bhavsar 《Journal of Thermal Analysis and Calorimetry》2013,111(1):267-271
The 0.04 M copper-doped lead iodate crystals grown in silica gel were characterized by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and thermo analytical techniques (TG, DTA, DTG and DSC). Raman and FTIR spectrum clearly indicate that the functional groups of undoped lead iodate were not altered by the addition of the dopant. Thermal analysis suggests that the thermal stability of lead iodate crystals decreases due to copper doping. 相似文献
15.
Summary A novel procedure had been developed for the preparation of RP packings. A C18 alkyl-chain was bound onto spherical silica (particle size dp=5 μm, s=300 m2g−1) with glycidoxypropyltrimethoxysilane as coupling agent. Elemental analysis, X-ray photoelectron spectroscopy (XPS), Fourier
transform infrared (FT-IR) and chromatographic evaluation confirmed the bonding of the packings and their RP behavior. 相似文献
16.
源自水稻壳的高比表面纳米二氧化硅负载12-磷钨酸:一种高效纳米催化剂用于几种有机反应(英文) 总被引:1,自引:0,他引:1
Nano silica was prepared from rice husk with high surface area.X-ray diffraction(XRD) pattern showed that the amorphous form of silica was produced.Chemical composition of the nano silica was estimated by X-ray fluorescence spectroscopy and CHN analysis.The nano silica was used as a support for H3PW12O40.The nano silica and nano silica supported H3PW12O40 were characterized by inductively coupled plasma,XRD,transmission electron microscopy(TEM),N2 adsorption-desorption,and Fourier transform infrared spectroscopy.TEM images of nano silica as well as the supported catalyst displayed average size of 6 and 7 nm,respectively.The catalyst showed excellent activity in some important organic reactions including Biginelli,Hantzsch,Mannich,and Claisen-Schmidt reactions with good reusability.Catalytic activity of this nano catalyst is an improvement over the commercially available silica that is used to support H3PW12O40. 相似文献
17.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1991,47(9-10):1251-1262
A sudy of a wide variety of coloured main group metal, transition metal coordination and transition metal organometallic complexes using Fourier transform Raman (FT-Raman) spectroscopy has demonstrated a high success rate (ca 50%) with good quality spectra obtained in short periods of time. It is suggested that FT-Raman spectroscopy should now be regarded as a routine spectroscopic tool for use in inorganic as well as organic research and teaching laboratories. 相似文献
18.
Daniela Saviello Emeline Pouyet Lucia Toniolo Marine Cotte Austin Nevin 《Analytica chimica acta》2014
Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile–butadiene–styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3 × 3 μm2) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time. 相似文献
19.
Cristiana Figus Masahide Takahashi Tongjit Kidchob Toshinobu Yoko Massimo Piccinini Maria Casula Plinio Innocenzi 《Journal of Sol-Gel Science and Technology》2009,52(3):408-414
Organic–inorganic films containing hybrid nanocrystals have been prepared by sol–gel processing in controlled conditions.
We have systematically changed the temperature and the aging time of a precursor sol containing an organically modified alkoxide
bearing an epoxy group, 3-glycidoxypropyltrimethoxysilane, to obtain a controlled crystallization of hybrid layered structures
in hybrid films. The precursor sol has been aged at different temperatures, from 5 to 60 °C, and for 1, 2 or 3 days; the films
have been deposited from the aged sol and immediately after characterized by X-ray diffraction, Fourier transform infrared
spectroscopy and Raman spectroscopy. We have observed that the formation of the hybrid crystals can be obtained only when
at least 50% of the epoxies are opened and a larger silica condensation is achieved. These conditions are reached after aging
at 60 °C for 1 day, or at longer aging times when the sol is aged at lower temperatures. Transmission electron microscopy
and optical polarized images have confirmed the formation of the hybrid crystals. 相似文献
20.
An expedient ‘click’ approach for the synthetic evaluation of ester‐triazole‐tethered organosilica conjugates 下载免费PDF全文
The present work articulates the synthesis of a new series of organo‐functionalized triethoxysilanes derived from versatile carboxylic acids and 3‐azidopropyltriethoxysilane in excellent yields. A proficient and convenient route implicating the Cu(I)‐catalysed 1,3‐cycloaddition of organic azide with terminal alkynes, labelled as click silylation, has been developed for the generation of ester‐triazole‐linked alkoxysilanyl scaffolds ( 4a – f ). All the synthesized compounds have been thoroughly characterized using elemental analysis and Fourier transform infrared, 1H NMR and 13C NMR spectroscopic techniques. Importantly, the fabricated alkoxysilanes are potentially amenable for an in situ sol–gel condensation reaction with silica nanospheres leading to the incorporation of organic functionality via covalent grafting onto the nanostructured particle system. As a proof of concept, a one‐pot preparation of organic–inorganic hybrid nanoparticles is presented using bis‐silane 4 f . The efficiency and selectivity of the prepared nanocomposite towards metal ions is highlighted using adsorption experiments, and the immobilized nanoparticles present a high sensing efficiency towards Cu2+ and Pb2+ ions while demonstrating better response than that of the bulk material. 相似文献