keyword
MENU ▼
Read by QxMD icon Read
search

Raman spectra

keyword
https://www.readbyqxmd.com/read/28821133/single-helix-in-v-type-starch-carrier-determines-the-encapsulation-capacity-of-ethylene
#1
Linfan Shi, Xiong Fu, Qiang Huang, Bin Zhang
V-type starch carriers with different single helix contents were prepared using alcoholic-alkaline treatment followed by ethanol precipitation. Ethylene gas was entrapped into V-type starch carriers using a solid encapsulation method. The morphological and structural properties of inclusion complexes (ICs) were characterized using scanning electron and light microscopy, X-ray diffractometry, (13)C solid-state nuclear magnetic resonance (NMR) and Raman spectroscopy. Aqueous ethanol treatment resulted in swelling and aggregation of starch granules, and B-type diffraction reflections were either reduced or completely lost with evolution of V-type pattern...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28820741/electromagnetic-and-optical-characteristics-of-nb5-doped-double-crossover-and-salmon-dna-thin-films
#2
Mitta Sekhar Babu, Sreekantha Reddy Dugasani, Soon-Gil Jung, Srivithya Vellampatti, Tuson Park, Sung Ha Park
We report the fabrication and physical characteristics of niobium ion (Nb5+)-doped double-crossover DNA (DX-DNA) and salmon DNA (SDNA) thin films. Different concentrations of Nb5+ ([Nb5+]) are coordinated into the DNA molecules, and the thin films are fabricated via substrate-assisted growth (DX-DNA) and drop-casting (SDNA) on oxygen plasma treated substrates. We conducted atomic force microscopy to estimate the optimum concentration of Nb5+ ([Nb5+]O = 0.08 mM) in Nb5+-doped DX-DNA thin films, up to which the DX-DNA lattices maintain their structures without deformation...
August 18, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28820602/intricate-resonant-raman-response-in-anisotropic-res2
#3
Amber McCreary, Jeffrey R Simpson, Yuanxi Wang, Daniel Rhodes, Kazunori Fujisawa, Luis Balicas, Madan Dubey, Vincent H Crespi, Mauricio Terrones, Angela R Hight Walker
The strong in-plane anisotropy of rhenium disulfide (ReS2) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS2 also presents advantages for optoelectronics, as it is both a direct-gap semiconductor for few-layer thicknesses (unlike MoS2 or WS2) and stable in air (unlike black phosphorus). Raman spectroscopy is one of the most powerful characterization techniques to non-destructively and sensitively probe the fundamental photo-physics of a 2D material...
August 18, 2017: Nano Letters
https://www.readbyqxmd.com/read/28820221/real-time-monitoring-of-plasmon-induced-proton-transfer-of-hypoxanthine-in-serum
#4
Binbin Zhou, Shaofei Li, Xianghu Tang, Pan Li, Xiaomin Cao, Borong Yu, Liangbao Yang, Jinhuai Liu
Intramolecular proton transfer of hypoxanthine, induced by application of a laser on the surface of a bare noble nanomaterial, was monitored in real time using surface-enhanced Raman spectroscopy (SERS). This monitoring demonstrated the dependence of the reaction on the identity of the nanomaterial and on the laser power density. The results pave the way for monitoring the proton transfer reaction in various relevant fields. In addition, we observed the presence of the proton transfer phenomenon of hypoxanthine in serum, providing a way to avoid the effect of proton transfer and hence achieve more reliable spectra of sera for clinical diagnosis...
August 18, 2017: Nanoscale
https://www.readbyqxmd.com/read/28819254/investigations-of-phase-transformation-in-monocrystalline-silicon-at-low-temperatures-via-nanoindentation
#5
Shunbo Wang, Hang Liu, Lixia Xu, Xiancheng Du, Dan Zhao, Bo Zhu, Miao Yu, Hongwei Zhao
Nanoindentations of monocrystalline silicon are conducted to investigate the phase transformation process at a temperature range from 292 K to 210 K. The load-displacement curves are obtained and the residual indents are detected by Raman spectra. MD simulations are also conducted to identify the phase state during nanoindentation. The results show that the low temperature has no influence on the generation of Si-II during loading process of indentation, but the phenomenon of pop-out is inhibited with the temperature decreasing...
August 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28817278/unveiling-the-aggregation-of-lycopene-in-vitro-and-in-vivo-uv-vis-resonance-raman-and-raman-imaging-studies
#6
Mika Ishigaki, Phiranuphon Meksiarun, Yasutaka Kitahama, Leilei Zhang, Hideki Hashimoto, Takuma Genkawa, Yukihiro Ozaki
The present study investigates the structure of lycopene aggregates both in vitro and in vivo using ultraviolet-visible (UV-vis) and Raman spectroscopies. The electronic absorption bands of the J- and H-aggregates in vitro shift to lower and higher energies, respectively, compared to that of the lycopene monomer. Along with these results, the frequencies of the ν1 Raman bands were shifted to lower and higher frequencies, respectively. By plotting the frequencies of the ν1 Raman band against the S0 → S2 transition energy, a linear relationship between the data set with different aggregation conformations can be obtained...
August 17, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28817096/time-resolved-study-of-nanomorphology-and-nanomechanic-change-of-early-stage-mineralized-electrospun-poly-lactic-acid-fiber-by-scanning-electron-microscopy-raman-spectroscopy-and-atomic-force-microscopy
#7
Mengmeng Wang, Yin Cai, Bo Zhao, Peizhi Zhu
In this study, scanning electron microscopy (SEM), Raman spectroscopy and high-resolution atomic force microscopy (AFM) were used to reveal the early-stage change of nanomorphology and nanomechanical properties of poly(lactic acid) (PLA) fibers in a time-resolved manner during the mineralization process. Electrospun PLA nanofibers were soaked in simulated body fluid (SBF) for different periods of time (0, 1, 3, 5, 7 and 21 days) at 10 °C, much lower than the conventional 37 °C, to simulate the slow biomineralization process...
August 17, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28812067/nonlinear-imaging-microscopy-for-assessing-structural-and-photochemical-modifications-upon-laser-removal-of-dammar-varnish-on-photosensitive-substrates
#8
M Oujja, S Psilodimitrakopoulos, E Carrasco, M Sanz, A Philippidis, A Selimis, P Pouli, G Filippidis, M Castillejo
The nonlinear optical microscopy (NLM) modalities of Multi-Photon Excited Fluorescence (MPEF) and Third Harmonic Generation (THG) have been combined in this work to characterize as a function of depth with micrometric resolution the type and extent of morphological and photochemical modifications that take place upon ultraviolet (UV) pulsed laser removal of a dammar varnish layer applied on a photosensitive substrate. The latter consists on a layer of the synthetic polymer poly-methyl methacrylate doped with a photosensitizer, the aromatic compound 1,4-di[2-(5-phenyloxazolyl)] benzene, that strongly fluoresces upon UV light illumination...
August 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28809979/raman-and-infrared-spectroscopy-differentiate-senescent-from-proliferating-cells-in-a-human-dermal-fibroblast-3d-skin-model
#9
Katharina Eberhardt, Christian Matthäus, Doreen Winter, Cornelia Wiegand, Uta-Christina Hipler, Stephan Diekmann, Jürgen Popp
Senescent cells contribute to tissue aging and dysfunction. Therefore, detecting senescent cells in skin is of interest for skin tumor diagnostics and therapy. Here, we studied the transition into senescence of human dermal fibroblasts (HDFs) in a three-dimensional (3D) human fibroblast-derived matrix (FDM). Senescent and proliferating cells were imaged by Raman spectroscopy (RS) and Fourier transform infrared (FTIR) spectroscopy. The obtained averaged spectra were analyzed using PLS-LDA. For these 3D cultured cells, RS and FTIR could clearly distinguish senescent from proliferating cells...
August 15, 2017: Analyst
https://www.readbyqxmd.com/read/28809977/correlation-between-collective-and-molecular-dynamics-in-ph-responsive-cyclodextrin-based-hydrogels
#10
C Bottari, L Comez, S Corezzi, F D'Amico, A Gessini, A Mele, C Punta, L Melone, A Pugliese, C Masciovecchio, B Rossi
UV Raman and Brillouin light scattering (BLS) experiments have been used in this study to explore the complex phase change behavior occurring in pH-responsive polysaccharide hydrogels as a function of temperature. Due to the different physical quantities measured by the two techniques, the joint analysis of Raman and BLS spectra has provided an unprecedented large-scale characterization of the molecular rearrangements and of the different kinds of hydrophilic and hydrophobic interactions that cooperate to determine the phase transformation observed in these hydrogels during the heating of the gel...
August 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28809794/exploration-of-the-structural-electronic-and-tunable-magnetic-properties-of-cu%C3%A2-m-m-sc-ni-clusters
#11
Dong Die, Ben-Xia Zheng, Xiao-Yu Kuang, Zheng-Quan Zhao, Jian-Jun Guo, Quan Du
The structural, electronic and magnetic properties of Cu₄M (M = Sc-Ni) clusters have been studied by using density functional theory, together with an unbiased CALYPSO structure searching method. Geometry optimizations indicate that M atoms in the ground state Cu₄M clusters favor the most highly coordinated position. The geometry of Cu₄M clusters is similar to that of the Cu₅ cluster. The infrared spectra, Raman spectra and photoelectron spectra are predicted and can be used to identify the ground state in the future...
August 15, 2017: Materials
https://www.readbyqxmd.com/read/28809419/environmental-stability-of-2d-anisotropic-tellurium-containing-nanomaterials-anisotropic-to-isotropic-transition
#12
Sijie Yang, Hui Cai, Bin Chen, Changhyun Ko, V Ongun Özçelik, D Frank Ogletree, Claire E White, Yuxia Shen, Sefaattin Tongay
We report on the vibrational (Raman) spectrum and structural transformation of semiconducting pseudo-1D GaTe and ZrTe3 nanomaterials driven by ambient molecular interactions at the nanoscale by angle-resolved Raman spectroscopy, atomic force microscopy (AFM), and environmental X-ray photoelectron (XPS) measurements. The results show that tellurium containing pseudo-1D materials undergo drastic structural and physical changes within a week. During this process, new Raman peaks start to emerge and surface roughness increases substantially...
August 15, 2017: Nanoscale
https://www.readbyqxmd.com/read/28805870/an-enhanced-degree-of-charge-transfer-in-dye-sensitized-solar-cells-with-a-zno-tio2-n3-ag-structure-as-revealed-by-surface-enhanced-raman-scattering
#13
Xiaolei Wang, Peng Li, Xiao Xia Han, Yasutaka Kitahama, Bing Zhao, Yukihiro Ozaki
A number of recent studies have focused on improving the performance of dye-sensitized solar cells (DSSCs). Cells with a ZnO-TiO2/N3/Ag structure have attracted particular attention because of their excellent power conversion efficiencies. Using a dendritic crystal ZnO-TiO2 composite semiconductor and Ag in conjunction leads to different charge-transfer (CT) processes, and this is the main theoretical basis for the improvement of DSSC performances. Thus, in the present study, TiO2/N3, ZnO/N3, ZnO-TiO2/N3, TiO2/N3/Ag, ZnO/N3/Ag, and ZnO-TiO2/N3/Ag assemblies have been fabricated and their CT processes have been monitored by using surface-enhanced Raman scattering (SERS) spectra, with particular focus on the differences caused by the synergistic effect of the ZnO-TiO2 component...
August 14, 2017: Nanoscale
https://www.readbyqxmd.com/read/28805059/probing-membrane-receptor-ligand-specificity-with-surface-and-tip-enhanced-raman-scattering
#14
Lifu Xiao, Karen A Bailey, Hao Wang, Zachary D Schultz
The specific interaction between a ligand and a protein is a key component in minimizing off-target effects in drug discovery. Investigating these interactions with membrane protein receptors can be quite challenging. In this report, we show how spectral variance observed in surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS) can be correlated with ligand specificity in affinity-based assays. Variations in the enhanced Raman spectra of three peptide ligands (i.e., cyclic-RGDFC, cyclic-isoDGRFC, and CisoDGRC), which have different binding affinity to αvβ3 integrin, are reported from isolated proteins and from receptors in intact cancer cell membranes...
August 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28800550/protein-based-medicines-analysis-by-raman-spectroscopy-for-the-detection-of-counterfeits
#15
Klara Dégardin, Anne Desponds, Yves Roggo
Protein-based medicines, or large molecule medicines, are innovative products used to treat various diseases like hepatitis or cancer. This new generation of molecules are usually expensive, and thus represents an attractive target for the counterfeiters. Due to the complexity of their chemical structure, their analysis for counterfeit detection is more difficult than small molecule medicines. The aim of the article is to demonstrate that Raman spectroscopy and microscopy can be used for the fast analysis of counterfeits of protein-based medicines...
July 20, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28800431/anharmonic-vibrational-analysis-of-s-trans-and-s-cis-conformers-of-acryloyl-fluoride-using-numerical-analytic-van-vleck-operator-perturbation-theory
#16
Sergey V Krasnoshchekov, Norman C Craig, Lidiya A Koroleva, Nikolay F Stepanov
A new gas-phase infrared (IR) spectrum of acryloyl fluoride (ACRF, CH2CHCFO) with a resolution of 0.1cm(-1) in the range 4000-450cm(-1) was measured. Theoretical ab initio molecular structures, full quartic potential energy surfaces (PES), and cubic surfaces of dipole moments and polarizability tensor components (electro-optical properties, EOP) of the s-trans and s-cis conformers of the ACRF were calculated by the second-order Møller-Plesset electronic perturbation theory with a correlation consistent Dunning triple-ζ basis set...
August 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28799753/theoretical-investigation-of-c-h-vibrational-spectroscopy-2-unified-assignment-method-of-ir-raman-and-sum-frequency-generation-spectra-of-ethanol
#17
Lin Wang, Tatsuya Ishiyama, Akihiro Morita
Using the flexible and polarizable model in the preceding paper, we performed comprehensive analysis of C-H stretching vibrations of ethanol and partially deuterated ones by molecular dynamics (MD) simulation. The overlapping band structures of the C-H stretching region including (i) methyl and methylene, (ii) the number of modes with Fermi resonances, and (iii) different trans/gauche conformers are disentangled by various analysis methods, such as isotope exchange, empirical potential parameter shift analysis, and separate calculations of conformers...
August 18, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28799588/the-vn3h-defect-in-diamond-a-quantum-mechanical-characterization
#18
Francesco Silvio Gentile, Simone Salustro, Mauro Causà, Alessandro Erba, Philippe Carbonniére, Roberto Dovesi
The VN3H defect in diamond (a vacancy surrounded by three nitrogen and one carbon atoms, the latter being saturated by a hydrogen atom) is investigated quantum-mechanically by use of a periodic supercell approach, an all-electron Gaussian-type basis set, "hybrid" functionals of density functional theory, and the Crystal program. Three fully optimized structural models (supercells containing 32, 64, and 128 atoms) are considered to investigate the effect of defect concentration. The electronic configuration of the defect is reported along with a description of its structural features...
August 11, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28794631/surface-enhanced-raman-spectroscopy-of-serum-accurately-detects-prostate-cancer-in-patients-with-prostate-specific-antigen-levels-of-4-10-ng-ml
#19
Na Chen, Ming Rong, Xiaoguang Shao, Heng Zhang, Shupeng Liu, Baijun Dong, Wei Xue, Tingyun Wang, Taihao Li, Jiahua Pan
The surface-enhanced Raman spectroscopy (SERS) of blood serum was investigated to differentiate between prostate cancer (PCa) and benign prostatic hyperplasia (BPH) in males with a prostate-specific antigen level of 4-10 ng/mL, so as to reduce unnecessary biopsies. A total of 240 SERS spectra from blood serum were acquired from 40 PCa subjects and 40 BPH subjects who had all received prostate biopsies and were given a pathological diagnosis. Multivariate statistical techniques, including principal component analysis (PCA) and linear discriminant analysis (LDA) diagnostic algorithms, were used to analyze the spectra data of serum from patients in control (CTR), PCa and BPH groups; results offered a sensitivity of 97...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28794508/proximity-effect-induced-superconducting-gap-in-topological-surface-states-a-point-contact-spectroscopy-study-of-nbse2-bi2se3-superconductor-topological-insulator-heterostructures
#20
Wenqing Dai, Anthony Richardella, Renzhong Du, Weiwei Zhao, Xin Liu, C X Liu, Song-Hsun Huang, Raman Sankar, Fangcheng Chou, Nitin Samarth, Qi Li
Proximity-effect-induced superconductivity was studied in epitaxial topological insulator Bi2Se3 thin films grown on superconducting NbSe2 single crystals. A point contact spectroscopy (PCS) method was used at low temperatures down to 40 mK. An induced superconducting gap in Bi2Se3 was observed in the spectra, which decreased with increasing Bi2Se3 layer thickness, consistent with the proximity effect in the bulk states of Bi2Se3 induced by NbSe2. At very low temperatures, an extra point contact feature which may correspond to a second energy gap appeared in the spectrum...
August 9, 2017: Scientific Reports
keyword
keyword
86995
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"