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Raman spectra

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https://www.readbyqxmd.com/read/28431313/raman-spectroscopy-for-the-characterization-of-different-fractions-of-hemp-essential-oil-extracted-at-130%C3%A2-c-using-steam-distillation-method
#1
Muhammad Asif Hanif, Haq Nawaz, Saima Naz, Rubina Mukhtar, Nosheen Rashid, Ijaz Ahmad Bhatti, Muhammad Saleem
In this study, Raman spectroscopy along with Principal Component Analysis (PCA) is used for the characterization of pure essential oil (pure EO) isolated from the leaves of the Hemp (Cannabis sativa L.,) as well as its different fractions obtained by fractional distillation process. Raman spectra of pure Hemp essential oil and its different fractions show characteristic key bands of main volatile terpenes and terpenoids, which significantly differentiate them from each other. These bands provide information about the chemical composition of sample under investigation and hence can be used as Raman spectral markers for the qualitative monitoring of the pure EO and different fractions containing different active compounds...
April 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28430428/full-potential-simulation-of-x-ray-raman-scattering-spectroscopy
#2
Yves Joly, Chiara Cavallari, Sergey A Guda, Christoph J Sahle
We present a new ab initio way to calculate x-ray Raman scattering spectra within the independent electron approximation. Our approach avoids any approximation about the shape of the used potential and leads to a good agreement between experiment and theory. We show that the momentum transfer dependence in two typical cases, the F K-edge in LiF and the B and N K-edges in hexagonal BN, are well reproduced. A more in-depth analysis of the electronic states and of the local atomic structure around the absorbing atoms is at hand...
April 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28430277/rapid-single-cell-detection-and-identification-of-pathogens-by-using-surface-enhanced-raman-spectroscopy
#3
N E Dina, H Zhou, A Colniţă, N Leopold, T Szoke-Nagy, C Coman, C Haisch
For the successful treatment of infections, real-time analysis and enhanced multiplex capacity, sensitivity and cost-effectiveness of the developed detection method are critical. In this work, surface-enhanced Raman scattering (SERS) was employed with the final aim of identification and discrimination of pathogenic bacteria, based on their detected SERS fingerprint at the single-cell level. Several genera of bacteria that are found in most of the isolated infections in bacteraemia were successfully identified in less than 5 minutes without the use of antibodies or other specific receptors...
April 21, 2017: Analyst
https://www.readbyqxmd.com/read/28424513/super-multiplex-vibrational-imaging
#4
Lu Wei, Zhixing Chen, Lixue Shi, Rong Long, Andrew V Anzalone, Luyuan Zhang, Fanghao Hu, Rafael Yuste, Virginia W Cornish, Wei Min
The ability to visualize directly a large number of distinct molecular species inside cells is increasingly essential for understanding complex systems and processes. Even though existing methods have successfully been used to explore structure-function relationships in nervous systems, to profile RNA in situ, to reveal the heterogeneity of tumour microenvironments and to study dynamic macromolecular assembly, it remains challenging to image many species with high selectivity and sensitivity under biological conditions...
April 19, 2017: Nature
https://www.readbyqxmd.com/read/28424509/evolution-of-crystal-structures-in-gete-during-phase-transition
#5
Kwangsik Jeong, Seungjong Park, Dambi Park, Min Ahn, Jeonghwa Han, Wonjun Yang, Hong-Sik Jeong, Mann-Ho Cho
We investigated changes in the crystal structure of GeTe during its phase transition. Using density functional theory (DFT) calculations, four possible crystal structures were identified: R3m, P1, Cm, and Fm3m. Among these, P1 and Cm were examined here for the first time. By calculating the internal energy of the crystal volume change, we verified that P1, R3m, and Cm can coexist in crystalline GeTe. The X-ray diffraction spectra of annealed and laser-irradiated GeTe films revealed coexisting P1 or R3m and Cm...
April 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28422511/semiclathrate-hydrates-in-tri-n-butylphosphine-oxide-tbpo-%C3%A2-water-and-tbpo-%C3%A2-water-%C3%A2-methane-systems
#6
Tatyana V Rodionova, Artem A Sizikov, Vladislav Yu Komarov, Galina V Villevald, Tamara D Karpova, Andrey Yu Manakov
In the present work we studied semiclathrate hydrates in the TBPO ‒ H2O and TBPO ‒ H2O ‒ CH4 systems. The stoichiometry, temperature and enthalpy of dissociation of TBPO semiclathrate hydrate crystals formed in TBPO - H2O binary system were found to be TBPO·33.6±0.9Н2О, 280.0 K, and 253.1±4.7 Jg(-1), respectively. The crystal structure determined by single crystal XRD analysis (150 K) was orthorhombic with space group Pbam and unit cell parameters a =19.9313(8) Å, b =23.4660(7) Å, c =12.1127(5) Å...
April 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28422206/cage-like-b39-clusters-with-the-bonding-pattern-of-%C3%AF-%C3%AF-double-delocalization-new-members-of-the-borospherene-family
#7
Xiao-Yun Zhao, Qiang Chen, Hai-Ru Li, Yue-Wen Mu, Hai-Gang Lu, Si-Dian Li
The recently observed cage-like borospherenes D2d B40(-/0) and C3/C2 B39(-) have attracted considerable attention in chemistry and materials science. Based on extensive global minimum searches and first-principles theory calculations, we present herein the possibility of cage-like Cs B39(+) (1) and Cs B39(+) (2) which possess five hexagonal and heptagonal faces and one filled hexagon and follow the bonding pattern of σ + π double delocalization with 12 delocalized π bonds over a σ-skeleton, adding two new members to the borospherene family...
April 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28421760/transient-resonance-raman-spectroscopy-of-a-light-driven-sodium-ion-pump-rhodopsin-from-indibacter-alkaliphilus
#8
Kousuke Kajimoto, Takashi Kikukawa, Hiroki Nakashima, Haruki Yamaryo, Yuta Saito, Tomotsumi Fujisawa, Makoto Demura, Masashi Unno
Sodium-ion-pump rhodopsin (NaR) is a microbial rhodopsin that transports Na(+) during its photocycle. Here we explore the photocycle mechanism of NaR from Indibacter alkaliphilus with transient absorption and transient resonance Raman spectroscopy. The transient absorption data indicate that the photocycle of NaR is K (545 nm) → L (490 nm)/M (420 nm) → O1 (590 nm) → O2 (560 nm) → NaR, where the L and M are formed as equilibrium states. The presence of K, L, M, and O intermediates was confirmed by the resonance Raman spectra with 442 and 532 nm excitation...
April 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28420283/design-and-characteristics-of-gellan-gum-beads-for-modified-release-of-meloxicam
#9
Tomasz Osmałek, Bartłomiej Milanowski, Anna Froelich, Mirosław Szybowicz, Wojciech Białowąs, Marcin Kapela, Piotr Gadziński, Katarzyna Ancukiewicz
The aim of the presented work was to design, formulate and evaluate the properties of low-acyl gellan macro beads with the potential application as carriers for oral delivery of meloxicam (MLX) in the prophylaxis of colorectal cancer. The beads were obtained by means of ionotropic gelation technique. Calcium chloride (1.0%, 9.0 × 10(-2) M) was used as the cross-linking agent. Nine different polymer, drug and surfactant (Tween®80) mixtures were used for production of the beads. The quantitative compositions of the mixtures were generated with the application of the Design of Experiments (DoE) modulus from the STATISTICA Software...
April 19, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/28420234/raman-spectroscopy-of-fish-oil-capsules-pufa-quantitation-plus-detection-of-ethyl-esters-and-oxidation
#10
Daniel P Killeen, Susan N Marshall, Elaine J Burgess, Keith C Gordon, Nigel B Perry
Fish oils are the primary dietary source of ω-3 polyunsaturated fatty acids (PUFA), but these compounds are prone to oxidation, and commercial fish oil supplements sometimes contain less PUFA than claimed. These supplements are predominantly sold in softgel capsules. In this work we show that Fourier-Transform (FT)-Raman spectra of fish oils (n=5) and ω-3 PUFA concentrates (n=6) can be acquired directly through intact softgel (gelatin) capsules. These spectra could be used to rapidly distinguish supplements containing ethyl esters from those triacylglyceride oils...
April 19, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28419826/melting-process-of-the-peritectic-mixture-of-lidocaine-and-ibuprofen-interpreted-by-site-percolation-theory-model
#11
Hikaru Kataoka, Yoshinori Sakaki, Kazushi Komatsu, Yohsuke Shimada, Satoru Goto
Eutectic mixtures are often used in the design and delivery of drugs. In this study, we examined the peritectic mixture of lidocaine (LDC) and ibuprofen (IBP) using differential scanning calorimetry, Raman spectroscopy, and microscopy. The obtained phase diagram shows that as the mixture is heated, first LDC melts at 293 K, then IBP dissolves in the liquefied LDC at 310 K, and finally all remaining crystals melt. In the (1)H NMR spectra, the signals of the carboxyl group in IBP and amide or amine group in LDC shift to the low magnetic field in the IBP/LDC mixtures, because of the intermolecular interaction between these moieties...
April 15, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28419719/spectroscopic-evidences-of-toxic-trans-crotonaldehyde-trapped-and-transformed-by-resveratrol-to-prevent-the-damage-of-mitochondrial-dna
#12
Yanwen Su, Lei Chen, Yanbin Su, Zhengqiang Li, Chuang Zhang, Tongxing Mu
The purpose of this study is to probe the spectroscopic evidences of toxic trans-crotonaldehyde (TCA) trapped and transformed by resveratrol (Res) to prevent the damage of mitochondrial DNA. In aldehyde dehydrogenase (ALDH) at the different pH or mitochondria, the spectroscopic characteristics of TCA trapped and transformed by Res were observed by means of both UV-vis and Raman spectra. When Res interacted with TCA, TCA peak at 316 nm immediately disappeared while Res main peak at 305 nm and shoulder peak at 320 nm were dramatically changed, Raman peaks of TCA at 1,688 cm(-1) assigned to CHO and 1,641 cm(-1) affiliated to CC were strikingly shifted, Raman peaks of Res itself were significantly displaced or disappeared, especially in mitochondria and ALDH at different pH...
April 16, 2017: IUBMB Life
https://www.readbyqxmd.com/read/28419111/time-resolved-and-label-free-monitoring-of-extracellular-metabolites-by-surface-enhanced-raman-spectroscopy
#13
Victoria Shalabaeva, Laura Lovato, Rosanna La Rocca, Gabriele C Messina, Michele Dipalo, Ermanno Miele, Michela Perrone, Francesco Gentile, Francesco De Angelis
Metabolomics is an emerging field of cell biology that aims at the comprehensive identification of metabolite levels in biological fluids or cells in a specific functional state. Currently, the major tools for determining metabolite concentrations are mass spectrometry coupled with chromatographic techniques and nuclear magnetic resonance, which are expensive, time consuming and destructive for the samples. Here, we report a time resolved approach to monitor metabolite dynamics in cell cultures, based on Surface Enhanced Raman Scattering (SERS)...
2017: PloS One
https://www.readbyqxmd.com/read/28418677/ph-dependence-of-ferricytochrome-c-conformational-transitions-during-binding-to-cardiolipin-membranes-evidence-for-histidine-as-the-distal-ligand-at-neutral-ph
#14
Bridget Milorey, Dmitry Malyshka, Reinhard Schweitzer-Stenner
The conformational changes of ferricytochrome c upon binding to cardiolipin-containing small unilamellar vesicles were studied at slightly acidic pH using fluorescence, visible circular dichroism, UV-visible absorption, and resonance Raman spectroscopy. The obtained spectroscopic response data suggest a mode of interaction, which is clearly distinct from the binding process observed at neutral pH. Evidence of a reversible and electrostatic binding mechanism under these conditions is provided through binding inhibition in the presence of 150 mM NaCl...
April 24, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28418636/defining-molecular-details-of-the-chemistry-of-biofilm-formation-by-raman-microspectroscopy
#15
Paul R Carey, Blake R Gibson, Jordan F Gibson, Michael E Greenberg, Hossein Heidari-Torkabadi, Marianne Pusztai-Carey, Sean T Weaver, Grant R Whitmer
Two protocols that allow for the comparison of Raman spectra of planktonic cells and biofilm formed from these cells in their growth phase have been developed. Planktonic cells are washed and flash-frozen in <1 min to reduce the time for metabolic changes during processing, prior to freeze-drying. Biofilm is formed by standing cells in 50 μL indentations in aluminum foil in an atmosphere of saturated water vapor for 24-48 h. The results for Escherichia coli type K12 cells, which do not readily form biofilm, are compared to those for Staphylococcus epidermidis cells, which prolifically synthesize biofilm...
April 19, 2017: Biochemistry
https://www.readbyqxmd.com/read/28415660/accuracy-of-raman-spectroscopy-in-differentiating-brain-tumor-from-normal-brain-tissue
#16
REVIEW
Jing Zhang, Yimeng Fan, Min He, Xuelei Ma, Yanlin Song, Ming Liu, Jianguo Xu
Raman spectroscopy could be applied to distinguish tumor from normal tissues. This meta-analysis was conducted to assess the accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue. PubMed and Embase were searched to identify suitable studies prior to Jan 1st, 2016. We estimated the pooled sensitivity, specificity, positive and negative likelihood ratios (LR), diagnostic odds ratio (DOR), and constructed summary receiver operating characteristics (SROC) curves to identity the accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue...
March 7, 2017: Oncotarget
https://www.readbyqxmd.com/read/28415596/renal-mass-biopsy-using-raman-spectroscopy-identifies-malignant-and-benign-renal-tumors-potential-for-pre-operative-diagnosis
#17
Yufei Liu, Zhebin Du, Jin Zhang, Haowen Jiang
The accuracy of renal mass biopsy to diagnose malignancy can be affected by multiple factors. Here, we investigated the feasibility of Raman spectroscopy to distinguish malignant and benign renal tumors using biopsy specimens. Samples were collected from 63 patients who received radical or partial nephrectomy, mass suspicious of cancer and distal parenchyma were obtained from resected kidney using an 18-gauge biopsy needle. Four Raman spectra were obtained for each sample, and Discriminant Analysis was applied for data analysis...
March 21, 2017: Oncotarget
https://www.readbyqxmd.com/read/28415382/alkali-etching-growth-of-nest-like-ag-mtio2-hierarchical-nanostructures-and-their-potential-applications
#18
Zongnan Zhang, Haijiao Zhang
Porous nanomaterials have attracted extensive interests in adsorption, catalysis, biosensors, and biomedicine due to their high surface area, well-defined pore structure and tunable pore size. However, how to obtain porous nanomaterials of desirable component and unique structure with multifunctionalities and synergetic properties is still a great challenge. In this work, a novel nest-like Ag@mTiO2 hierarchical nanostructure with Ag nanoparticle as the core and a mesoporous crystalline TiO2 as the protective shell was successfully prepared by layer-by-layer assembly technique and alkali-etching hydrothermal route...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28415343/normal-vibrational-modes-of-phospholipid-bilayers-observed-by-low-frequency-raman-scattering
#19
N V Surovtsev, A A Dmitriev, S A Dzuba
Low-frequency Raman spectra of multilamellar vesicles made either of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) have been studied in a wide temperature range. Below 0^{∘}C two peaks are found at frequencies around 8-9 and 14-17cm^{-1} and attributed to the normal vibrational modes of the phospholipid bilayer, which are determined by the bilayer thickness and stiffness (elastic modulus). The spectral positions of the peaks depend on the temperature and the bilayer composition...
March 2017: Physical Review. E
https://www.readbyqxmd.com/read/28414908/an-experimental-computational-study-of-carbon-nanotubes-effects-on-mitochondrial-respiration-in-silico-nano-qspr-machine-learning-models-based-on-new-raman-spectra-transform-with-markov-shannon-entropy-invariants
#20
Michael González-Durruthy, Luciane Carla Alberici, Zeki Naal, David T Atique-Sawazaki, Carlos Curti, José Manuel Vázquez-Naya, Humbert Gonzalez-Diaz, Cristian Robert Munteanu
The study of selective toxicity of carbon nanotubes (CNT) on mitochondria (CNT-mitotoxicity) is of major interest for future biomedical applications. In the current work, the mitochondrial oxygen consumption (E3) is measured under three experimental conditions by exposure to pristine and oxidized CNTs (hydroxylated and carboxylated). Respiratory functional assays showed that the information of the CNT-Raman spectroscopy could be useful to predict structural parameters of mitotoxicity induced by CNTs. The in vitro functional assays show that the mitochondrial oxidative phosphorylation by ATP-synthase (or state V3 of respiration) was not perturbed in isolated rat-liver mitochondria...
April 17, 2017: Journal of Chemical Information and Modeling
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