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https://www.readbyqxmd.com/read/28103517/a-noninvasive-cancer-detection-strategy-based-on-gold-nanoparticle-surface-enhanced-raman-spectroscopy-of-urinary-modified-nucleosides-isolated-by-affinity-chromatography
#1
Shangyuan Feng, Zuci Zheng, Yuanji Xu, Jinyong Lin, Guannan Chen, Cuncheng Weng, Duo Lin, Sufang Qiu, Min Cheng, Zufang Huang, Lan Wang, Rong Chen, Shusen Xie, Haishan Zeng
The search for tumor biomarkers in the urine for cancer diagnosis is currently a hot topic in clinical oncology, with potential for cancer screening and diagnosis. Modified nucleosides excreted through the urine are considered to be a general tumor marker for various cancer types. Herein, we explore a new method that utilizes surface-enhanced Raman scattering (SERS) spectroscopy to obtain a complete biochemical profile of urinary modified nucleosides. In our method, modified nucleosides are first isolated from urine sample utilizing the excellent separation ability of affinity chromatography; then supplemented with gold (Au) nanoparticles as substrate for SERS spectroscopy analysis...
January 5, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28102565/development-of-novel-sers-probe-for-selective-screening-of-healthy-prostate-from-malignant-prostate-cancer-cells-using-zn-ii
#2
Paresh Chandra Ray, Avijit Pramanik, Suhash Reddy Chavva, Bhanu Priya Viraka Nellore, Kelli May, Tejus Matthew, Stacy Jones, Aruna Vangara
Even in 21st century, prostate cancer remains the second leading cause of cancer death for men. Since normal prostate gland contains the most Zn(II) and there are huge differences in Zn(II) content between the healthy and malignant prostate cancer cells, mobile zinc can be used as a biomarker for prostate cancer prediction. Current article reports the design of novel and highly efficient surface enhanced Raman spectroscopy (SERS) probe using p-(imidazole)azo) benzenethiol attached gold nanoparticle as a Raman reporter, which has the capability to identify prostate cancer cells based on Zn(II) sensing...
January 19, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28102368/novel-electron-phonon-relaxation-pathway-in-graphite-revealed-by-time-resolved-raman-scattering-and-angle-resolved-photoemission-spectroscopy
#3
Jhih-An Yang, Stephen Parham, Daniel Dessau, Dmitry Reznik
Time dynamics of photoexcited electron-hole pairs is important for a number of technologies, in particular solar cells. We combined ultrafast pump-probe Raman scattering and photoemission to directly follow electron-hole excitations as well as the G-phonon in graphite after an excitation by an intense laser pulse. This phonon is known to couple relatively strongly to electrons. Cross-correlating effective electronic and phonon temperatures places new constraints on model-based fits. The accepted two-temperature model predicts that G-phonon population should start to increase as soon as excited electron-hole pairs are created and that the rate of increase should not depend strongly on the pump fluence...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101853/investigation-on-the-effects-of-the-formation-of-a-silver-flower-like-structure-on-graphene
#4
Rozalina Zakaria, Siti Fatimah Az Zahra Yusoff, Kok Chung Law, Chin Seong Lim, Harith Ahmad
In this report, we experimentally investigate the formation of "flower-like silver structures" on graphene. Using an electrochemical deposition technique with deposition times of 2.5 and 5 min, agglomerations of silver nanoparticles (AgNPs) were deposited on the graphene surfaces, causing the formation of "flower-like structures" on the graphene substrate. Localized surface plasmon resonance (LSPR) was observed in the interaction between the structures and the graphene substrate. The morphology of the samples was observed using a field-emission scanning electron microscope (FESEM) and Raman spectroscopy...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28101415/endoscopic-sensing-of-alveolar-ph
#5
D Choudhury, M G Tanner, S McAughtrie, F Yu, B Mills, T R Choudhary, S Seth, T H Craven, J M Stone, I K Mati, C J Campbell, M Bradley, C K I Williams, K Dhaliwal, T A Birks, R R Thomson
Previously unobtainable measurements of alveolar pH were obtained using an endoscope-deployable optrode. The pH sensing was achieved using functionalized gold nanoshell sensors and surface enhanced Raman spectroscopy (SERS). The optrode consisted of an asymmetric dual-core optical fiber designed for spatially separating the optical pump delivery and signal collection, in order to circumvent the unwanted Raman signal generated within the fiber. Using this approach, we demonstrate a ~100-fold increase in SERS signal-to-fiber background ratio, and demonstrate multiple site pH sensing with a measurement accuracy of ± 0...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28099894/handheld-new-technology-raman-and-portable-ft-ir-spectrometers-as-complementary-tools-for-the-in-situ-identification-of-organic-materials-in-modern-art
#6
M Vagnini, F Gabrieli, A Daveri, D Sali
A non-invasive approach has been carried out to characterize painting materials used in modern artworks conserved in the art collection of Carandente's museum at Palazzo Collicola in Spoleto (Italy). This work is focused on the cross-validation of the handheld BRAVO Raman spectrometer, that uses a sequentially Shifted Excitation (SSE) to mitigate fluorescence, for the characterization specifically of organic materials. The analytical procedure, combining XRF, Raman and reflection infrared spectroscopy, allowed a complete characterization of the artists' palettes; particularly eight different synthetic dyes belonging to the class of pigment red (PR) and pigment yellow (PY...
January 5, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28099549/warming-up-for-mechanosynthesis-temperature-development-in-ball-mills-during-synthesis
#7
Hannes Kulla, Manuel Wilke, Franziska Fischer, Mathias Röllig, Christiane Maierhofer, Franziska Emmerling
We present a first direct measurement of the temperature during milling combined with in situ Raman spectroscopy monitoring. The data reveal a low temperature increase due to the mechanical impact and clear temperature increases as a consequence of the reaction heat. Based on the data, temperature rises as postulated in the magma plasma and hot spot theory can be excluded for soft matter milling syntheses.
January 18, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28099157/high-quality-epitaxial-graphene-by-hydrogen-etching-of-3c-sic-111-thin-film-on-si-111
#8
Bharati Gupta, Carlo Mariani, Josh Lipton-Duffin, Nunzio Motta, Pierluigi Mondelli, Maria Betti
Etching with atomic hydrogen as a preparation step before the high-temperature growth process of graphene onto a thin 3C-SiC film grown on Si(111) greatly improves the structural quality of topmost graphene layers. Pit formation and island coalescence, which are typical of graphene growth by SiC graphitization, are quenched and accompanied by widening of the graphene domain sizes to hundreds of nm, and by a significant reduction in surface roughness down to a single substrate bilayer. The surface reconstructions expected for graphene and the underlying layer are shown with atomic resolution by scanning tunnelling microscopy (STM)...
January 18, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28098966/surface-optical-rectification-from-layered-mos2-crystal-by-thz-time-domain-surface-emission-spectroscopy
#9
Yuanyuan Huang, Lipeng Zhu, Qiyi Zhao, Yaohui Guo, Zhaoyu Ren, Jin Tao Bai, Xin Long Xu
Surface optical rectification was observed from the layered semiconductor molybdenum disulfide (MoS2) crystal via terahertz (THz) time-domain surface emission spectroscopy under linearly polarized femtosecond laser excitation. The radiated THz amplitude of MoS2 has a linear dependence on ever-increasing pump fluence and thus quadratic with the pump electric field, which discriminates from the surface Dember field induced THz radiation in InAs and the transient photocurrent induced THz generation in graphite...
January 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28098209/crystal-growth-of-dirac-semimetal-zrsis-with-high-magnetoresistance-and-mobility
#10
Raman Sankar, G Peramaiyan, I Panneer Muthuselvam, Christopher J Butler, Klauss Dimitri, Madhab Neupane, G Narsinga Rao, M-T Lin, F C Chou
High quality single crystal ZrSiS as a theoretically predicted Dirac semimetal has been grown successfully using a vapor phase transport method. The single crystals of tetragonal structure are easy to cleave into perfect square-shaped pieces due to the van der Waals bonding between the sulfur atoms of the quintuple layers. Physical property measurement results including resistivity, Hall coefficient (RH), and specific heat are reported. The transport and thermodynamic properties suggest a Fermi liquid behavior with two Fermi pockets at low temperatures...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28098185/hydrocarbons-in-phlogopite-from-kasenyi-kamafugitic-rocks-sw-uganda-cross-correlated-afm-confocal-microscopy-and-raman-imaging
#11
Daniele Moro, Giovanni Valdrè, Ernesto Mesto, Fernando Scordari, Maria Lacalamita, Giancarlo Della Ventura, Fabio Bellatreccia, Salvatore Scirè, Emanuela Schingaro
This study presents a cross-correlated surface and near surface investigation of two phlogopite polytypes from Kasenyi kamafugitic rocks (SW Uganda) by means of advanced Atomic Force Microscopy (AFM), confocal microscopy and Raman micro-spectroscopy. AFM revealed comparable nanomorphology and electrostatic surface potential for the two mica polytypes. A widespread presence of nano-protrusions located on the mica flake surface was also observed, with an aspect ratio (maximum height/maximum width) from 0.01 to 0...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28096353/high-coulombic-efficiency-aluminum-ion-battery-using-an-alcl3-urea-ionic-liquid-analog-electrolyte
#12
Michael Angell, Chun-Jern Pan, Youmin Rong, Chunze Yuan, Meng-Chang Lin, Bing-Joe Hwang, Hongjie Dai
In recent years, impressive advances in harvesting renewable energy have led to a pressing demand for the complimentary energy storage technology. Here, a high Coulombic efficiency (∼99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analog electrolyte made from a mixture of AlCl3 and urea in a 1.3:1 molar ratio. The battery displays discharge voltage plateaus around 1.9 and 1.5 V (average discharge = 1.73 V) and yielded a specific cathode capacity of ∼73 mAh g(-1) at a current density of 100 mA g(-1) (∼1...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28094503/controlled-doping-in-graphene-monolayers-by-trapping-organic-molecules-at-graphene-substrate-interface
#13
Pawan Kumar Srivastava, Premlata Yadav, Varsha Rani, Subhasis Ghosh
We report controlled doping in graphene monolayers through charge transfer interaction by trapping selected organic molecules between graphene and underneath substrates. Controllability has been demonstrated in terms of shift in Raman spectra and Dirac point in graphene monolayers. The shift in the Dirac point to positive (negative) gate bias in the transfer characteristics of graphene monolayer based field effect transistor is a clear indication of p(n) type doping in graphene as a consequence of charge transfer interaction between organic molecules and graphene...
January 17, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28090610/highly-dispersible-edge-selectively-oxidized-graphene-with-improved-electrical-performance
#14
Jisoo Park, Yern Seung Kim, Sae Jin Sung, Taehoon Kim, Chong Rae Park
We prepared liquid phase exfoliated edge-selectively oxidized graphene (LPEOG) with a high concentration in water (∼14.7 mg ml(-1)) and a high ratio of a single layer (70%). The edge of graphite was selectively oxidized by step II oxidation of the modified Hummers method, and we subsequently exfoliated the edge-selectively oxidized graphite (EOG) into LPEOG. The edge selective oxidation of the LPEOG was confirmed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), zeta-potentiometry, Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and transmission electron microscopy (TEM)...
January 16, 2017: Nanoscale
https://www.readbyqxmd.com/read/28088490/microwave-based-treatments-of-wheat-kernels-do-not-abolish-gluten-epitopes-implicated-in-celiac-disease
#15
Carmen Gianfrani, Gianfranco Mamone, Barbara la Gatta, Alessandra Camarca, Luigia Di Stasio, Francesco Maurano, Stefania Picascia, Vito Capozzi, Giuseppe Perna, Gianluca Picariello, Aldo Di Luccia
Microwave based treatment (MWT) of wet wheat kernels induced a striking reduction of gluten, up to <20 ppm as determined by R5-antibodybased ELISA, so that wheat could be labeled as gluten-free. In contrast, analysis of gluten peptides by G12 antibody-based ELISA, mass spectrometry-based proteomics and in vitro assay with T cells of celiac subjects, indicated no difference of antigenicity before and after MWT. SDS-PAGE analysis and Raman spectroscopy demonstrated that MWT simply induced conformational modifications, reducing alcohol solubility of gliadins and altering the access of R5-antibody to the gluten epitopes...
January 11, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28088279/archaeometric-analysis-of-roman-bronze-coins-from-the-magna-mater-temple-using-solid-state-voltammetry-and-electrochemical-impedance-spectroscopy
#16
Francesca Di Turo, Noemí Montoya, Joan Piquero-Cilla, Caterina De Vito, Fulvio Coletti, Gabriele Favero, Antonio Doménech-Carbó
Voltammetry of microparticles (VMP) and electrochemical impedance spectroscopy (EIS) techniques, complemented by SEM-EDX and Raman spectroscopy, were applied to a set of 15 Roman bronze coins and one Tessera from the temple of Magna Mater (Rome, Italy). The archaeological site, dated back between the second half and the end of the 4th century A.D., presented a complicated stratigraphic context. Characteristic voltammetric patterns for cuprite and tenorite for sub-microsamples of the corrosion layers of the coins deposited onto graphite electrodes in contact with 0...
February 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28088121/synthesis-of-ctab-intercalated-graphene-and-its-application-for-the-adsorption-of-ar265-and-ao7-dyes-from-water
#17
Mohammed Yusuf, Moonis Ali Khan, Marta Otero, E C Abdullah, Masaaki Hosomi, Akihiko Terada, Shohei Riya
Environmental applications of graphene (GN) are limited by the occurrence of aggregation. Herein, graphene oxide (GO) was synthesized, reduced to GN by ascorbic acid, and intercalated with cetyltrimethylammonium bromide (CTAB). GN-CTAB was characterized by Boehm's titration, N2 adsorption/desorption, Fourier transform infrared spectroscopy, Raman spectroscopy, Fluorescence spectrophotometry, X-ray diffraction and Scanning electron microscopy. Then, GN-CTAB was used for the adsorptive removal of acid red 265 (AR265) and acid orange 7 (AO7) dyes from water both under batch and column operation...
January 5, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28088082/nature-of-phase-transitions-in-ammonium-oxofluorovanadates-a-vibrational-spectroscopy-study-of-nh4-3vo2f4-and-nh4-3vof5
#18
REVIEW
Yu V Gerasimova, A S Oreshonkov, N M Laptash, A N Vtyurin, A S Krylov, N P Shestakov, A A Ershov, A G Kocharova
Two ammonium oxofluorovanadates, (NH4)3VO2F4 and (NH4)3VOF5, have been investigated by temperature-dependent infrared and Raman spectroscopy methods to determine the nature of phase transitions (PT) in these compounds. Dynamics of quasioctahedral groups was simulated within the framework of semi-empirical approach, which justified the cis-conformation of VO2F4(3-) (C2v) and the C4v geometry of VOF5(3-). The observed infrared and Raman spectra of both compounds at room temperature (RT) revealed the presence at least of two crystallographically independent octahedral groups...
January 4, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28081502/quantitative-determinations-using-portable-raman-spectroscopy
#19
Chelliah V Navin, Chaitanya Tondepu, Roxana Toth, Latevi S Lawson, Jason D Rodriguez
A portable Raman spectrometer was used to develop chemometric models to determine percent (%) drug release and potency for 500mg ciprofloxacin HCl tablets. Parallel dissolution and chromatographic experiments were conducted alongside Raman experiments to assess and compare the performance and capabilities of portable Raman instruments in determining critical drug attributes. All batches tested passed the 30min dissolution specification and the Raman model for drug release was able to essentially reproduce the dissolution profiles obtained by ultraviolet spectroscopy at 276nm for all five batches of the 500mg ciprofloxacin tablets...
December 30, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28081493/optical-and-vibrational-properties-of-phosphorylcholine-based-contact-lenses-experimental-and-theoretical-investigations
#20
Katarzyna Filipecka, Rafał Miedziński, Maciej Sitarz, Jacek Filipecki, Małgorzata Makowska-Janusik
The Raman, MIR and UV-vis spectroscopy have been used to characterize Omafilcon A material constructing the one of the Proclear family contact lenses. The Omafilcon A is hydrogel material composed of 2-hydroxyethyl methacrylate (HEMA) and 2-methacryloyloxyethyl phosphorylcholine (PC) polymers crosslinked with ethyleneglycol dimethacrylate (EGDMA). Vibrational and electronic properties of the Omafilcon A material were also investigated by quantum chemical calculations. Experimentally obtained Raman, MIR and optical spectra were compared to the theoretical ones calculated applying RHF and DFT methodology...
January 5, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
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