keyword
MENU ▼
Read by QxMD icon Read
search

Raman

keyword
https://www.readbyqxmd.com/read/28346552/incorporation-of-vanadium-into-the-framework-of-hydroxyapatites-importance-of-the-vanadium-content-and-ph-conditions-during-the-precipitation-step
#1
Sarah Petit, Thrimurthulu Gode, Cyril Thomas, Stanislaw Dzwigaj, Yannick Millot, Dalil Brouri, Jean-Marc Krafft, Gwenaelle Rousse, Christel Laberty-Robert, Guylène Costentin
Even though vanadium-modified hydroxyapatite (V-HAp) samples are very promising systems for oxidative dehydrogenation of propane, the incorporation of vanadium into the hydroxyapatite framework was reported to be limited and to lead to over-stoichiometric compounds. Here, the synthesis of a Ca10(PO4)6-x(VO4)x(OH)2 stoichiometric solid solution using a co-precipitation method is monitored in the whole composition range (0 ≤ x ≤ 6) by controlling the pH of the precipitation medium, with continuous (the first series of samples) or periodic (the second series of samples) addition of NH4OH during the precipitation step or during the maturation step, respectively...
March 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28345879/vibrational-probes-from-small-molecule-solvatochromism-theory-and-experiments-to-applications-in-complex-systems
#2
Bartosz Błasiak, Casey H Londergan, Lauren J Webb, Minhaeng Cho
The vibrational frequency of a chosen normal mode is one of the most accurately measurable spectroscopic properties of molecules in condensed phases. Accordingly, infrared absorption and Raman scattering spectroscopy have provided valuable information on both distributions and ensemble-average values of molecular vibrational frequencies, and these frequencies are now routinely used to investigate structure, conformation, and even absolute configuration of chemical and biological molecules of interest. Recent advancements in coherent time-domain nonlinear vibrational spectroscopy have allowed the study of heterogeneous distributions of local structures and thermally driven ultrafast fluctuations of vibrational frequencies...
March 27, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28345878/multispectral-optical-tweezers-for-biochemical-fingerprinting-of-cd9-positive-exosome-subpopulations
#3
Randy P Carney, Sidhartha Hazari, Macalistair Colquhoun, Di Tran, Billanna Hwang, Michael S Mulligan, James D Bryers, Eugenia Girda, Gary S Leiserowitz, Zachary James Smith, Kit S Lam
Extracellular vesicles (EVs), including exosomes, are circulating nanoscale particles heavily implicated in cell signaling, and can be isolated in vast numbers from human biofluids. Study of their molecular profiling and materials properties is currently underway for purposes of describing a variety of biological functions and diseases. However, the large, and as yet unquantified, variety of EV subpopulations differing in composition, size, and likely function, necessitates characterization schemes capable of measuring single vesicles...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28345869/characterization-of-the-aerosol-based-synthesis-of-uranium-particles-as-a-potential-reference-material-for-micro-analytical-methods
#4
Ronald Middendorp, Martin Dürr, Alexander Knott, Fabien Pointurier, Dario Ferreira Sanchez, Valerie Ann Samson, Daniel Grolimund
A process for production of micrometer-sized particles composed of uranium oxide using aerosol spray pyrolysis is characterized with respect to the various production parameters. The aerosol is generated using a vibrating orifice aerosol generator providing monodisperse droplets, which are oxidized in a subsequent heat treatment. The final particles are characterized with micro analytical methods to determine size, shape, internal morphology, chemical and structural properties in order to assess the suitability of the produced particles as a reference material for micro analytical methods, in particular for mass-spectrometry...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28345862/quantification-of-lipid-metabolism-in-living-cells-through-the-dynamics-of-lipid-droplets-measured-by-stimulated-raman-scattering-imaging
#5
Chi Zhang, Junjie Li, Lu Lan, Ji-Xin Cheng
Dysregulation of lipid metabolism is associated with many diseases including cancer. Lipid droplet (LD), a ubiquitous organelle in mammalian cells, serves as a hub for lipid metabolism. Conventional assays on the measurement of lipid metabolism rely on the quantification of the lipid composition or amount. Such methods cannot distinguish LDs having different bio-functionalities in living cells, and thus could be inaccurate in measuring the instantaneous lipogenesis of the living cells. We applied label-free stimulated Raman scattering microscopy to quantify the LDs' spatial-temporal dynamics, which showed direct links to cellular lipid metabolisms and can separate LDs involving in different metabolic events...
March 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28345659/oral-chromium-picolinate-impedes-hyperglycemia-induced-atherosclerosis-and-inhibits-proatherogenic-protein-tsp-1-expression-in-stz-induced-type-1-diabetic-apoe-mice
#6
Rituparna Ganguly, Soumyadip Sahu, Vahagn Ohanyan, Rebecca Haney, Ronaldo J Chavez, Shivani Shah, Siri Yalamanchili, Priya Raman
Increasing evidence suggests thrombospondin-1 (TSP-1), a potent proatherogenic matricellular protein, as a putative link between hyperglycemia and atherosclerotic complications in diabetes. We previously reported that the micronutrient chromium picolinate (CrP), with long-standing cardiovascular benefits, inhibits TSP-1 expression in glucose-stimulated human aortic smooth muscle cells in vitro. Here, we investigated the atheroprotective action of orally administered CrP in type 1 diabetic apolipoprotein E-deficient (ApoE(-/-)) mice and elucidated the role of TSP-1 in this process...
March 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28345640/degree-of-functionalisation-dependence-of-individual-raman-intensities-in-covalent-graphene-derivatives
#7
Philipp Vecera, Siegfried Eigler, Maria Koleśnik-Gray, Vojislav Krstić, Asmus Vierck, Janina Maultzsch, Ricarda A Schäfer, Frank Hauke, Andreas Hirsch
Covalent functionalisation of graphene is a continuously progressing field of research. The optical properties of such derivatives attract particular attention. In virtually all optical responses, however, an enhancement in peak intensity with increase of sp(3) carbon content, and a vanishing of the peak position shift in monolayer compared to few-layer systems, is observed. The understanding of these seemingly connected phenomena is lacking. Here we demonstrate, using Raman spectroscopy and in situ electrostatic doping techniques, that the intensity is directly modulated by an additional contribution from photoluminescent π-conjugated domains surrounded by sp(3) carbon regions in graphene monolayers...
March 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28345533/fabrication-of-plasmonic-cavity-arrays-for-sers-analysis
#8
Ning Li, Lei Feng, Fei Teng, Nan Lu
The plasmonic cavity arrays are ideal substrates for surface enhanced Raman scattering (SERS) analysis because they can provide large hot area for analyte molecules. The large area increases the probability to make more analyte molecules on hot spots and leads to a high reproducibility. Therefore, to develop a simple method for creating cavity arrays is important. Herein, we demonstrate how to fabricate a V and W shape cavity arrays by a simple method based on self-assembly. Briefly, the V and W shape cavity arrays are respectively fabricated by taking KOH etching on a nanohole and a nanoring array patterned silicon (Si) slides, which are generated by taking a reactive ion etching on a monolayer of polystyrene spheres patterned blank Si slide and a Si slide covered with a monolayer of octadecyltrichlorosilane...
March 27, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28344383/spectroscopic-properties-of-poly-9-9-dioctylfluorene-thin-films-possessing-varied-fractions-of-%C3%AE-phase-chain-segments-enhanced-photoluminescence-efficiency-via-conformation-structuring
#9
Aleksandr Perevedentsev, Nathan Chander, Ji-Seon Kim, Donal D C Bradley
Poly(9,9-dioctylfluorene) (PFO) is a widely studied blue-emitting conjugated polymer, the optoelectronic properties of which are strongly affected by the presence of a well-defined chain-extended "β-phase" conformational isomer. In this study, optical and Raman spectroscopy are used to systematically investigate the properties of PFO thin films featuring a varied fraction of β-phase chain segments. Results show that the photoluminescence quantum efficiency (PLQE) of PFO films is highly sensitive to both the β-phase fraction and the method by which it was induced...
October 1, 2016: Journal of Polymer Science. Part B, Polymer Physics
https://www.readbyqxmd.com/read/28343348/process-analytical-techniques-for-hot-melt-extrusion-and-their-application-to-amorphous-solid-dispersions
#10
REVIEW
Patrick Hitzer, Tim Bäuerle, Tobias Drieschner, Edwin Ostertag, Katharina Paulsen, Holger van Lishaut, Günter Lorenz, Karsten Rebner
Newly developed active pharmaceutical ingredients (APIs) are often poorly soluble in water. As a result the bioavailability of the API in the human body is reduced. One approach to overcome this restriction is the formulation of amorphous solid dispersions (ASDs), e.g., by hot-melt extrusion (HME). Thus, the poorly soluble crystalline form of the API is transferred into a more soluble amorphous form. To reach this aim in HME, the APIs are embedded in a polymer matrix. The resulting amorphous solid dispersions may contain small amounts of residual crystallinity and have the tendency to recrystallize...
March 25, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28342983/lipid-quantification-by-raman-microspectroscopy-as-a-potential-biomarker-in-prostate-cancer
#11
Jordan O'Malley, Rahul Kumar, Andrey Kuzmin, Artem Pliss, Neelu Yadav, Srimmitha Balachandar, Jianmin Wang, Kristopher Attwood, Paras N Prasad, Dhyan Chandra
Metastatic castration recurrent prostate cancer (mCRPC) remains incurable and is one of the leading causes of cancer-related death among American men. Therefore, detection of prostate cancer (PCa) at early stages may reduce PCa-related mortality in men. We show that lipid quantification by vibrational Raman Microspectroscopy and Biomolecular Component Analysis may serve as a potential biomarker in PCa. Transcript levels of lipogenic genes including sterol regulatory element-binding protein-1 (SREBP-1) and its downstream effector fatty acid synthase (FASN), and rate-limiting enzyme acetyl CoA carboxylase (ACACA) were upregulated corresponding to both Gleason score and pathologic T stage in the PRAD TCGA cohort...
March 23, 2017: Cancer Letters
https://www.readbyqxmd.com/read/28342752/chitosan-doped-hybrid-tio2-nanocomposite-based-sol-gel-coating-for-the-corrosion-resistance-of-aluminum-metal-in-3-5-nacl-medium
#12
Balaji J, Sethuraman M G
The study outlines the role of chitosan, a biopolymer on corrosion behavior of Hy/nano-TiO2 based sol-gel coating over aluminum metal. In this study organic-inorganic hybrid sols were synthesized through hydrolysis and condensation of 3-glycidoxypropyltrimethoxy silane (GPTMS), tetraethoxysilane (TEOS) and titanium (IV) isopropoxide (TIP) in acidic solution. Chitosan was doped into sol-gel matrix and self-assembled over aluminum substrate. The resultant chitosan-doped-Hy/nano-TiO2 sol-gel coating was characterized by Fourier Transform Infrared (FT-IR) spectra, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDX) analyses...
March 22, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28342724/a-hypergraph-and-arithmetic-residue-based-probabilistic-neural-network-for-classification-in-intrusion-detection-systems
#13
M R Gauthama Raman, Nivethitha Somu, Kannan Kirthivasan, V S Shankar Sriram
Over the past few decades, the design of an intelligent Intrusion Detection System (IDS) remains an open challenge to the research community. Continuous efforts by the researchers have resulted in the development of several learning models based on Artificial Neural Network (ANN) to improve the performance of the IDSs. However, there exists a tradeoff with respect to the stability of ANN architecture and the detection rate for less frequent attacks. This paper presents a novel approach based on Helly property of Hypergraph and Arithmetic Residue-based Probabilistic Neural Network (HG AR-PNN) to address the classification problem in IDS...
February 17, 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/28342630/statins-attenuate-but-do-not-eliminate-the-reverse-epidemiology-of-total-serum-cholesterol-in-patients-with-non-ischemic-chronic-heart-failure
#14
Hanna Fröhlich, Nandita Raman, Tobias Täger, Dieter Schellberg, Kevin M Goode, Syed Kazmi, Morten Grundtvig, Torstein Hole, John G F Cleland, Hugo A Katus, Stefan Agewall, Andrew L Clark, Dan Atar, Lutz Frankenstein
BACKGROUND: In patients with chronic heart failure (CHF) increasing levels of total serum cholesterol are associated with improved survival - while statin usage is not. The impact of statin treatment on the "reverse epidemiology" of cholesterol is unclear. METHODS: 2992 consecutive patients with non-ischemic CHF due to left ventricular systolic dysfunction from the Norwegian CHF Registry and the CHF Registries of the Universities of Hull, UK, and Heidelberg, Germany, were studied...
March 9, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28342541/continuous-gradient-temperature-raman-spectroscopy-and-differential-scanning-calorimetry-of-n-3dpa-and-dha-from-100-to-10%C3%A2-c
#15
C Leigh Broadhurst, Walter F Schmidt, Julie K Nguyen, Jianwei Qin, Kuanglin Chao, Steven R Aubuchon, Moon S Kim
Docosahexaenoic acid (DHA, 22:6n-3) is exclusively utilized in fast signal processing tissues such as retinal, neural and cardiac. N-3 docosapentaenoic acid (n-3DPA, 22:5n-3), with just one less double bond, is also found in the marine food chain yet cannot substitute for DHA. Gradient temperature Raman spectroscopy (GTRS) applies the temperature gradients utilized in differential scanning calorimetry (DSC) to Raman spectroscopy, providing a straightforward technique to identify molecular rearrangements that occur near and at phase transitions...
March 22, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/28342356/heterogeneous-oxidative-desulfurization-of-diesel-fuel-catalyzed-by-mesoporous-polyoxometallate-based-polymeric-hybrid
#16
Huawei Yang, Bin Jiang, Yongli Sun, Luhong Zhang, Zhaohe Huang, Zhaoning Sun, Na Yang
In this work, the simple preparation of novel polymer supported polyoxometallates (POMs) catalysts has been reported. Soluble task-specific cross-linked poly (ionic liquid) (PIL) was prepared with N,​N-​dimethyl-​dodecyl-​(4-​vinylbenzyl) ammonium chloride and divinylbenzene as co-monomers. The as-prepared cationic PILs were assembled with different commercial POMs to form the interlinked mesoporous catalysts, and the formation mechanism was provided. The catalytic oxidation activities of the catalysts were closely related to the formation pathway of their corresponding peroxide active species...
March 10, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28342308/shape-selective-catalysis-and-surface-enhanced-raman-scattering-studies-using-ag-nanocubes-nanospheres-and-aggregated-anisotropic-nanostructures
#17
Subrata Kundu, Wei Dai, Yunyun Chen, Lian Ma, Yuan Yue, Alexander M Sinyukov, Hong Liang
Three morphologies of silver nanoparticles (Ag NPs) such as nanocubes, aggregated anisotropic Ag NPs, and nanospheres were prepared using polystyrene sulfonate (PSS) and citrate as stabilizing agents utilizing a simple wet-chemical and microwave heating route respectively. Ag nanocubes were prepared within one min through microwave heating whereas anisotropic Ag NPs and spherical Ag NPs via 5 and 30min of normal stirring at room temperature (RT) respectively. The shape effect of three different morphologies of Ag NPs were examined in catalysis reaction and in surface enhanced Raman scattering (SERS) studies...
March 16, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28341018/using-skin-carotenoids-to-assess-dietary-changes-in-students-after-1-academic-year-of-participating-in-the-shaping-healthy-choices-program
#18
Lori M Beccarelli, Rachel E Scherr, Madan Dharmar, Igor V Ermakov, Werner Gellermann, Lisa Jahns, Jessica D Linnell, Carl L Keen, Francene M Steinberg, Heather M Young, Sheri Zidenberg-Cherr
OBJECTIVE: To determine whether fourth-grade students participating in the Shaping Healthy Choices Program (SHCP), a school-based nutrition intervention, would change vegetable and carotenoid intake measured by skin carotenoids and dietary intake. METHODS: Single-group pretest-posttest with a self-selected, convenience sample of students (n = 30) participating in the SHCP, which lasted 1 academic year (9 months). Dietary intake of vegetables and carotenoids as measured by Block food frequency questionnaire and skin carotenoids as measured by Raman spectroscopy were collected at the school preintervention and postintervention...
January 2017: Journal of Nutrition Education and Behavior
https://www.readbyqxmd.com/read/28340991/sers-based-ultrasensitive-detection-of-organophosphorus-nerve-agents-via-substrate-s-surface-modification
#19
Qian Zhao, Guangqiang Liu, Hongwen Zhang, Fei Zhou, Yue Li, Weiping Cai
Highly efficient detection of the organicphosphor nerve agents such as sarin and soman, based on surface enhanced Raman scattering (SERS) effect, has been in challenge due to their weak adsorption property on coin metals. In this paper, a new strategy is presented to achieve the SERS-based ultrasensitive detection of sarin-simulated agent methanephosphonic acid (MPA) via the surface modification of SERS-substrates. The Au-coated Si nanocone array is surface-modified with 2-aminoethanethiol and used as SERS-substrate for detection of MPA...
February 15, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28340940/axially-modified-paddlewheel-diruthenium-ii-iii-ibuprofenato-metallodrugs-and-the-influence-of-the-structural-modification-on-u87mg-and-a172-human-glioma-cell-proliferation-apoptosis-mitosis-and-migration
#20
Hanif-Ur-Rehman, Tatiana E Freitas, Renata N Gomes, Alison Colquhoun, Denise de Oliveira Silva
The metallodrug chloridotetrakis(ibuprofenato)diruthenium(II,III) ([Ru2(Ibp)4Cl] or RuIbpCl (1), Ibp=carboxylate anion derived from the non-steroidal anti-inflammatory drug ibuprofen) has shown promising results in vitro and in vivo, which point to its potential as an inhibitor of glioma tumour growth in vivo. In order to get insight into the influence of structural changes on the biological response of the metallodrug, the [Ru2(Ibp)4] metal-metal multiply bonded paddlewheel unit was modified for the axial ligand...
December 2016: Journal of Inorganic Biochemistry
keyword
keyword
10933
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"