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Raman spectroscopy

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https://www.readbyqxmd.com/read/28646704/location-and-characterization-of-lignin-in-tracheid-cell-walls-of-radiata-pine-pinus-radiata-d-don-compression-woods
#1
Miao Zhang, Catherine Lapierre, Noor Liyana Nouxman, Michel K Nieuwoudt, Bronwen G Smith, Ramesh R Chavan, Brian H McArdle, Philip J Harris
Tilted stems of softwoods form compression wood (CW) and opposite wood (OW) on their lower and upper sides, respectively. More is known about the most severe form of CW, severe CW (SCW), but mild CWs (MCWs) also occur widely. Two grades of MCWs, MCW1 and MCW2, as well as SCW and OW were identified in the stems of radiata pine (Pinus radiata) that had been slightly tilted. The four wood types were identified by the distribution of lignin in the tracheid walls determined by fluorescence microscopy. A solution of the fluorescent dye acridine orange (AO) (0...
June 15, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28646583/sebum-lipids-influence-macrophage-polarization-and-activation
#2
M Lovászi, M Mattii, K Eyerich, Attila Gácsi, Erzsébet Csányi, D Kovács, R Rühl, A Szegedi, L Kemény, M Ståhle, C C Zouboulis, S Eyerich, D Törőcsik
BACKGROUND: As lipids are known to regulate macrophage functions it is reasonable to suppose that a sebocyte - macrophage axis mediated by sebum lipids may exist. OBJECTIVE: To investigate if sebocytes could contribute to the differentiation, polarization and function of macrophages with their secreted lipids. METHODS: Oil-red-O lipid staining and Raman spectroscopy were used to assess the dermal lipid content and penetration. Immunohistochemistry was used to analyse the macrophage subsets...
June 24, 2017: British Journal of Dermatology
https://www.readbyqxmd.com/read/28646246/identification-of-particles-in-raw-materials
#3
Kathryn Lee, Markus Lankers, Oliver Valet
Raw materials need to be of a certain quality with respect to physical and chemical composition. They also need to have no contaminants in the form of particles because these could get into the product or indicate the raw materials are not pure enough to make a good quality product. When particles are found, it is important to identify their chemical and elemental composition to correct any process errors that can cause them and to have acceptable quality of the final product. Sources of materials can be the environment, process equipment and processing, and packaging...
June 23, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28646193/fabrication-of-nitrogen-doped-nano-onions-and-their-electrocatalytic-activity-toward-the-oxygen-reduction-reaction
#4
E Y Choi, C K Kim
Nitrogen-doped nano-onions (NNO) were prepared as electrocatalytic materials for the oxygen reduction reaction (ORR). The nano-onions (NO), spherical graphitic material particles, were prepared by pyrolysis of nanodiamonds (ND). Oxidized NO (ONO) was prepared from NO by a modified Hummers' method, and this was mixed with urea, followed by pyrolysis, resulting in the formation of NNO. The nitrogen content and molar ratio of nitrogen-containing groups in the NNOs were varied by controlling the oxygen content of ONO to explore the effect of nitrogen content on the ORR activity...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28645764/electrochemical-behavior-of-pb-ii-on-a-heparin-modified-chitosan-graphene-nanocomposite-film-coated-glassy-carbon-electrode-and-its-sensitive-detection
#5
Priya T, Dhanalakshmi N, Thinakaran N
In this study, we developed a novel composite material containing biological macromolecules like heparin and chitosan coated on reduced graphene oxide (rGO) for the modification of glassy carbon electrode (hep/CS-rGO/GC). It can be applied for the sensitive electrochemical detection of Pb(2+) by square wave anodic stripping voltammetry (SWASV). The physicochemical analysis such as XRD, FTIR, FESEM and Raman spectroscopy techniques revealed that an effective functionalization occurred at the rGO surface. The consequence of deposition and stripping of metal ions by various electrochemical parameters such as supporting electrolytes, pH value, deposition potential, and deposition time were carefully studied and optimized...
June 20, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28645097/raman-spectroscopy-differentiates-between-sensitive-and-resistant-multiple-myeloma-cell-lines
#6
Domenico Franco, Sebastiano Trusso, Enza Fazio, Alessandro Allegra, Caterina Musolino, Antonio Speciale, Francesco Cimino, Antonella Saija, Fortunato Neri, Marco S Nicolò, Salvatore P P Guglielmino
Current methods for identifying neoplastic cells and discerning them from their normal counterparts are often nonspecific and biologically perturbing. Here, we show that single-cell micro-Raman spectroscopy can be used to discriminate between resistant and sensitive multiple myeloma cell lines based on their highly reproducible biomolecular spectral signatures. In order to demonstrate robustness of the proposed approach, we used two different cell lines of multiple myeloma, namely MM.1S and U266B1, and their counterparts MM...
June 15, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28644491/mastering-high-resolution-tip-enhanced-raman-spectroscopy-towards-a-shift-of-perception
#7
REVIEW
Marie Richard-Lacroix, Yao Zhang, Zhenchao Dong, Volker Deckert
Recent years have seen tremendous improvement of our understanding of high resolution reachable in TERS experiments, forcing us to re-evaluate our understanding of the intrinsic limits of this field, but also exposing several inconsistencies. On the one hand, more and more recent experimental results have provided us with clear indications of spatial resolutions down to a few nanometres or even on the subnanometre scale. Moreover, lessons learned from recent theoretical investigations clearly support such high resolutions, and vice versa the obvious theoretical impossibility to evade high resolution from a purely plasmonic point of view...
June 23, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28644485/probing-the-early-stages-of-photoreception-in-photoactive-yellow-protein-with-ultrafast-time-domain-raman-spectroscopy
#8
Hikaru Kuramochi, Satoshi Takeuchi, Kento Yonezawa, Hironari Kamikubo, Mikio Kataoka, Tahei Tahara
Unveiling the nuclear motions of photoreceptor proteins in action is a crucial goal in protein science in order to understand their elaborate mechanisms and how they achieve optimal selectivity and efficiency. Previous studies have provided detailed information on the structures of intermediates that appear during the later stages (>ns) of such photoreception cycles, yet the initial events immediately after photoabsorption remain unclear because of experimental challenges in monitoring nuclear rearrangements on ultrafast timescales, including protein-specific low-frequency motions...
July 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28642619/understanding-the-unusual-response-to-high-pressure-in-kbe2bo3f2
#9
D H Yu, M Avdeev, D H Sun, L Q Huston, Thomas B Shiell, Q B Sun, T Lu, Q Gu, H Liu, J E Bradby, N Yie, Y Liu, J Y Wang, G J McIntyre
Strong anisotropic compression with pressure on the remarkable non-linear optical material KBe2BO3F2 has been observed with the linear compression coefficient along the c axis found to be about 40 times larger than that along the a axis. An unusual non-monotonic pressure response was observed for the a lattice parameter. The derived bulk modulus of 31 ± 1 GPa indicates that KBe2BO3F2 is a very soft oxide material yet with stable structure up to 45 GPa. A combination of high-pressure synchrotron powder X-ray diffraction, high-pressure Raman spectroscopy, and Density Functional Theory calculations points to the mechanism for the unusual pressure response being due to the competition between the K-F bond length and K-F-K bond angle and the coupling between the stretching and twisting vibration modes...
June 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28641745/long-term-stability-of-an-injection-molded-zirconia-bone-level-implant-a-testing-protocol-considering-aging-kinetics-and-dynamic-fatigue
#10
Benedikt C Spies, Madeleine E Maass, Erik Adolfsson, Valter Sergo, Tobias Kiemle, Christoph Berthold, Elisa Gurian, Stefano Fornasaro, Kirstin Vach, Ralf-Joachim Kohal
OBJECTIVE: Separately addressing the fatigue resistance (ISO 14801, evaluation of final product) and aging behavior (ISO 13356, standardized sample) of oral implants made from yttria-stabilized zirconia proved to be insufficient in verifying their long-term stability, since (1) implant processing is known to significantly influence transformation kinetics and (2) aging, up from a certain level, is liable to decrease fatigue resistance. Therefore, the aim of this investigation was to apply a new testing protocol considering environmental conditions adequately inducing aging during dynamic fatigue...
June 19, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
https://www.readbyqxmd.com/read/28641418/measuring-the-carrier-dynamics-of-photocatalyst-micrograins-using-the-christiansen-effect
#11
Gangbei Zhu, Wei Lu, Jiangrui Zhu, Yunliang Li, Liwei Guo, Yuxiang Weng
The optical measurement of photocatalyst materials is subject to Mie scattering when the particle size is comparable to the wavelength of the probe light. A novel approach was developed to deal with this scattering problem in the transient spectroscopy of photocatalyst micrograins using the Christiansen effect because the probe light in the vicinity of the Christiansen frequency can be transmitted. Scattering theory was used to analyze the transient spectra of micrograins and estimate the extinction coefficient at the Christiansen frequency...
June 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28641236/analytical-evidences-of-the-use-of-iron-gall-ink-as-a-pigment-on-miniature-paintings
#12
Maurizio Aceto, Elisa Calà
Iron-gall ink (IGI) has been used by scribes for writing since at least the 4th century CE. Another typical use of this ink was for drawing: many Old Masters created beautiful sketches in brown-black hues. Despite its widespread use to draw lines, it seems like IGI was hardly used for painting as well. In fact, the number of identification on manuscripts is very low at present. This could be partially due to a lack of reliable diagnostic information. In this work we tried to better define the possibility of identifying IGI as a pigment on illuminate manuscripts, evaluating the pros and cons of three different techniques: UV-visible diffuse reflectance spectrophotometry with optic fibres (FORS), Raman spectroscopy and XRF spectrometry...
June 15, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28640617/5-methylhydantoin-from-isolated-molecules-in-a-low-temperature-argon-matrix-to-solid-state-polymorphs-characterization
#13
Bernardo A Nogueira, Gulce O Ildiz, João Canotilho, M Ermelinda S Eusébio, Marta Sofia C Henriques, José A Paixão, Rui Fausto
The molecular structure, vibrational spectra and photochemistry of 5-methylhydantoin (C4H6N2O2; 5-MH) were studied by matrix isolation infrared spectroscopy and theoretical calculations at the DFT(B3LYP)/6-311++G(d,p) theory level. The Natural Bond Orbital (NBO) analysis approach was used to study in detail the electronic structure of the minimum energy structure of 5-MH, namely the specific characteristics of the σ and π electronic systems of the molecule, and the stabilizing orbital interactions. UV irradiation of 5-MH isolated in argon matrix resulted in its photofragmentation through a single photochemical pathway, yielding isocyanic acid, ethanimine and carbon monoxide, thus following a pattern already observed before for the parent hydantoin and 1-methylhydantoin molecules...
June 22, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28640537/changes-in-the-biomechanical-properties-of-a-single-cell-induced-by-nonthermal-atmospheric-pressure-micro-dielectric-barrier-discharge-plasma
#14
Hyeongwon Choi, Eun Ha Choi, Kyung Sook Kim
Mechanical properties of a single cell are closely related to the fate and functions of the cell. Changes in mechanical properties may cause diseases or cell apoptosis. Selective cytotoxic effects of nonthermal atmospheric pressure micro-dielectric barrier discharge (DBD) plasma have been demonstrated on cancer cells. In this work, changes in the mechanical properties of a single cell induced by nonthermal atmospheric pressure micro-DBD plasma were investigated using atomic force microscopy (AFM). Two cervical cancer cell lines (HeLa and SiHa) and normal human fibroblast cells (HFBs) were exposed to micro-DBD plasma for various exposure times...
June 22, 2017: Microscopy Research and Technique
https://www.readbyqxmd.com/read/28640313/expanding-applications-of-sers-through-versatile-nanomaterials-engineering
#15
M Fernanda Cardinal, Emma Vander Ende, Ryan A Hackler, Michael O McAnally, Peter C Stair, George C Schatz, Richard P Van Duyne
Surface-enhanced Raman scattering (SERS) spectroscopy has evolved into a cross-disciplinary analytical technique by unveiling relevant chemical, biological, material, and structural information. The focus of this review is on two critical properties for successfully expanding applications of SERS spectroscopy: quality of the plasmonic substrate and molecule localization to the substrate. In this review, we discuss recent work on quantifying SERS distance dependence, key factors for substrate characterization and performance evaluation, expansion of SERS applications through substrate development for UV plasmonics and short-distance capture strategies for optimizing analyte-surface structures...
June 22, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28640306/tip-enhanced-raman-spectroscopy-from-early-developments-to-recent-advances
#16
REVIEW
Tanja Deckert-Gaudig, Atsushi Taguchi, Satoshi Kawata, Volker Deckert
An analytical technique operating at the nanoscale must be flexible regarding variable experimental conditions while ideally also being highly specific, extremely sensitive, and spatially confined. In this respect, tip-enhanced Raman scattering (TERS) has been demonstrated to be ideally suited to, e.g., elucidating chemical reaction mechanisms, determining the distribution of components and identifying and localizing specific molecular structures at the nanometre scale. TERS combines the specificity of Raman spectroscopy with the high spatial resolution of scanning probe microscopies by utilizing plasmonic nanostructures to confine the incident electromagnetic field and increase it by many orders of magnitude...
June 22, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28640186/analysis-of-serotonin-molecules-on-silver-nanocolloids-a-raman-computational-and-experimental-study
#17
Felicia S Manciu, John D Ciubuc, Emma M Sundin, Chao Qiu, Kevin E Bennet
Combined theoretical and experimental analysis of serotonin by quantum chemical density functional calculations and surface-enhanced Raman spectroscopy, respectively, is presented in this work to better understand phenomena related to this neurotransmitter's detection and monitoring at very low concentrations specific to physiological levels. In addition to the successful ultrasensitive analyte detection on silver nanoparticles for concentrations as low as 10(-11) molar, the relatively good agreement between the simulated and experimentally determined results indicates the presence of all serotonin molecular forms, such as neutral, ionic, and those oxidized through redox reactions...
June 22, 2017: Sensors
https://www.readbyqxmd.com/read/28639667/recent-progress-in-surface-enhanced-raman-spectroscopy-for-biological-and-biomedical-applications-from-cells-to-clinics
#18
REVIEW
D Cialla-May, X-S Zheng, K Weber, J Popp
The application of surface-enhanced Raman spectroscopy (SERS) in biological and biomedical detection schemes is feasible due to its excellent molecular specificity and high sensitivity as well as the capability of SERS to be performed in complex biological compositions. SERS-based investigation of cells, which are the basic structure and functional unit of organisms, represents the starting point of this review. It is demonstrated that SERS provides a deep understanding of living cells as well as their microenvironment which is needed to assess the development of diseases...
June 22, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28639560/mechanical-properties-of-decellularized-extracellular-matrix-coated-with-ticapcon-film
#19
I V Sukhorukova, A N Sheveyko, K L Firestein, Ph V Kiryukhantsev-Korneev, D Golberg, D V Shtansky
For the first time the surface of decellularized extracellular matrix (DECM) was modified via deposition of a multicomponent bioactive nanostructured film for improvement of the DECM's mechanical properties. TiCaPCON films were deposited onto the surface of intact and decellularized ulna, radius, and humerus bones by magnetron sputtering of TiC0.5 + 10%Ca3(PO4)2 and Ti targets in a gaseous mixture of Ar + N2. The film structure was studied using x-ray diffraction, scanning and transmission electron microscopy, and Raman spectroscopy...
June 22, 2017: Biomedical Materials
https://www.readbyqxmd.com/read/28639437/ultrasound-assisted-green-economic-synthesis-of-hydroxyapatite-nanoparticles-using-eggshell-bio-waste-and-study-of-mechanical-and-biological-properties-for-orthopaedic-applications
#20
Vijay H Ingole, Kamal Hany Hussein, Anil A Kashale, Kalyani Ghule, Tomaž Vuherer, Vanja Kokol, Jia-Yaw Chang, Yong-Chien Ling, Aruna Vinchurkar, Hom N Dhakal, Anil V Ghule
Nanostructured hydroxyapatite (HAp) is most favorable candidate biomaterial for bone tissue engineering because of its bioactive and osteoconductive properties. Herein, we report for the first time ultrasound assisted facile and economic approach for the synthesis of nanocrystalline hydroxyapatite (Ca10 (PO4 )6 (OH)2 ) using recycled eggshell bio-waste referred as EHAp. The process involves the reaction of eggshell bio-waste as a source of calcium and ammonium dihydrogen orthophosphate as a phosphate source...
June 22, 2017: Journal of Biomedical Materials Research. Part A
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