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Infra-Red Spectroscopy

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https://www.readbyqxmd.com/read/28895733/evidence-for-a-double-well-in-the-first-triplet-excited-state-of-2-thiouracil
#1
Daisuke Koyama, Matthew J Milner, Andrew J Orr-Ewing
The computationally predicted presence of two structurally distinct minima in the first triplet excited (T1) state of 2-thiouracil (2TU) is substantiated by sub-picosecond transient vibrational absorption spectroscopy (TVAS) in deuterated acetonitrile solution. Following 300-nm ultraviolet excitation to the second singlet excited state of 2TU, a transient infrared absorption band centered at 1643 cm(-1) is observed within our minimum time resolution of 0.3 ps. It is assigned either to 2TU molecules in the S1 state, or to vibrationally hot T1 state molecules...
September 12, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28878252/efficient-bioimaging-with-diaminodicyanoquinodimethanes-selective-imaging-of-epidermal-and-stomatal-cells-and-insight-into-the-molecular-level-interactions
#2
N Senthilnathan, Ch G Chandaluri, T P Radhakrishnan
The enhanced fluorescence emission of diaminodicyanoquinodimethanes (DADQs) in rigid and aggregated states holds great promise for bioimaging applications. This is demonstrated through their efficient application in epidermal and stomatal imaging with selective staining of cell walls and nuclei. Major advantages include the small quantities (a few nmols) of the fluorophore required, choice of DADQs soluble in water and organic solvents, and quick staining of the specimen in buffer-free state and in buffer medium...
September 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28873305/does-the-residues-chirality-modify-the-conformation-of-a-cyclo-dipeptide-vibrational-spectroscopy-of-protonated-cyclo-diphenylalanine-in-the-gas-phase
#3
Ivan Alata, Ariel Francis Pérez-Mellor, Feriel Ben Nasr, Debora Scuderi, Vincent Steinmetz, Fabrice Gobert, Nejmeddine Jaïdane, Anne Zehnacker-Rentien
The structure of a protonated diketopiperazine dipeptide, cyclo diphenylalanine, is studied by means of Infra-Red Multiple Photon Dissociation (IRMPD) spectroscopy combined with quantum chemical calculations. Protonation exclusively occurs on the oxygen site and, in the most stable conformer, results to an intramolecular OH…π interaction, accompanied by a CH…π interaction. Higher-energy conformers with free OH and NH…π interactions are observed as well, due to kinetic trapping. Optimization of the intramolecular interactions involving the aromatic ring dictates the geometry of the benzyl substituents...
September 5, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28869320/spin-changes-accompany-ultrafast-structural-interconversion-in-the-ground-state-of-a-cobalt-nitrosyl-complex
#4
Hugo Marroux, Basile Curchod, Charly Faradji, Timothy Shuttleworth, Hazel Sparkes, Paul Pringle, Andrew Orr-Ewing
Ultrafast, reversible intersystem crossing (ISC) is reported under ambient conditions for the ground electronic state of the pentacoordinate cobalt nitrosyl complexes, [CoX₂(NO)(PMePh₂)₂] (X = Cl, Br), in solution. ISCs on such short timescales are more typically observed in electronically excited states reached by absorption of ultraviolet or visible light. Singlet and triplet electron spin states of the complex, corresponding to two different isomers, are populated at room temperature, and the two isomers exchange on a timescale of a few picoseconds...
September 4, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28863675/note-modification-of-an-ftir-spectrometer-for-optoelectronic-characterizations
#5
N Puspitosari, C Longeaud
We propose a very simple system to be adapted to a Fourier Transform Infra-Red (FTIR) spectrometer with which three different types of characterizations can be done: the Fourier transform photocurrent spectroscopy, the recording of reflection-transmission spectra of thin film semiconductors, and the acquisition of spectral responses of solar cells. In addition to gather three techniques into a single apparatus, this FTIR-based system also significantly reduces the recording time and largely improves the resolution of the measured spectra compared to standard equipments...
August 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28859809/selenium-nanoparticle-enriched-biomass-of-yarrowia-lipolytica-enhances-growth-and-survival-of-artemia-salina
#6
Faseela Hamza, Amogh Vaidya, Mugdha Apte, Ameeta Ravi Kumar, Smita Zinjarde
Controlling disease outbreaks is a major challenge in aquaculture farms and conventional methods are often ineffective. Nutritional supplementation and probiotic preparations help in reducing severity of such infections. The generally regarded as safe yeast (Yarrowia lipolytica) was used in the current study. A marine strain of Y. lipolytica exhibited tolerance towards sodium selenite and formed cell associated selenium nanoparticles (SeNPs). The synthesized nanoparticles were characterized by UV-vis spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM) observations...
November 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28851642/cu-nanoparticles-synthesis-using-biological-molecule-of-p-granatum-seeds-extract-as-reducing-and-capping-agent-growth-mechanism-and-photo-catalytic-activity
#7
Nosheen Nazar, Ismat Bibi, Shagufta Kamal, Munawar Iqbal, Shazia Nouren, Kashif Jalani, Muhammad Umair, Sadia Atta
In view of extended applications of nanoparticles, the nanoparticles synthesis is an extensive research field and green synthesis is one of the co-friendly methodologies. Plant extract mediated synthesis of nanoparticles has gained much attention in current decade. In current investigation, copper nanoparticles (CuNPs) were prepared using P. granatum seeds extract (biological molecules) from copper(II) chloride salt. The synthesized CuNPs were characterized by UV-Visible spectroscopy, X-ray diffraction measurements (XRD), scanning electron microscopy (SEM), Energy Dispersive X- Ray Spectroscopy (EDX), Fourier transform infra-red spectroscopy (FTIR) and atomic force microscopy techniques...
August 26, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28850777/controlling-protein-surface-orientation-by-strategic-placement-of-oligo-histidine-tags
#8
Dorothee Wasserberg, Jordi Cabanas-Danés, Jord Prangsma, Shane O'Mahony, Pierre-Andre Cazade, Eldrich Tromp, Christian Blum, Damien Thompson, Jurriaan Huskens, Vinod Subramaniam, Pascal Jonkheijm
We report oriented immobilization of proteins using the standard hexahistidine (His6)-Ni(2+):NTA (nitrilotriacetic acid) methodology, which we systematically tuned to give control of surface coverage. Fluorescence microscopy and surface plasmon resonance measurements of self-assembled monolayers (SAMs) of red fluorescent proteins (TagRFP) showed that binding strength increased by 1 order of magnitude for each additional His6-tag on the TagRFP proteins. All TagRFP variants with His6-tags located on only one side of the barrel-shaped protein yielded a 1...
September 13, 2017: ACS Nano
https://www.readbyqxmd.com/read/28841428/a-new-polymorph-of-ciprofloxacin-saccharinate-structural-characterization-and-pharmaceutical-profile
#9
Pawanpreet Singh, Renu Chadha
In this study, a new polymorph of ciprofloxacin saccharinate has been thoroughly evaluated with respect to structural as well as biopharmaceutical properties. Preliminary characterization of the new polymorph was performed by differential scanning calorimetry and thermogravimetric analysis, later confirmed by Fourier transform infra-red spectroscopy. The crystal structure was determined from the powder X-ray diffraction pattern using the direct-space algorithm. It lies in the triclinic P-1 space group. It is having lattice parameters different from previously reported forms...
August 12, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28836727/organometallic-synthesis-of-cuo-nanoparticles-application-in-low-temperature-co-detection
#10
Myrtil L Kahn, Justyna Jońca, Andrey Ryzhikov, Ségolène Palussière, Jérome Esvan, Katia Fajerwerg, Philippe Menini, Pierre Fau
A metalorganic approach has been employed for the preparation of anisotropic CuO nanoparticles. These nanostructures have been characterized by transmission and high resolution transmission electron microscopy, field-emission scanning electron microscopy, X-ray powder diffraction, Fourier transform infra-red spectroscopy and X-ray photoelectron spectroscopy. The CuO nanoparticles have been deposited as gas sensitive layers on miniaturized silicon devices. At an operating temperature of 210°C, the sensors present an optimum response toward carbon monoxide correlated with a fast response (Rn) and short recovery time...
August 24, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28816405/synthesis-density-functional-theory-calculations-and-luminescence-of-lanthanide-complexes-with-2-6-bis-3-methoxybenzylidene-hydrazinocarbonyl-pyridine-schiff-base-ligand
#11
Ziyad A Taha, Taher S Ababneh, Ahmed K Hijazi, Qutaiba Abu-Salem, Abdulaziz M Ajlouni, Shroq Ebwany
A pyridine-diacylhydrazone Schiff base ligand, L = 2,6-bis[(3-methoxy benzylidene)hydrazinocarbonyl]pyridine was prepared and characterized by single crystal X-ray diffraction. Lanthanide complexes, Ln-L, {[LnL(NO3 )2 ]NO3 .xH2 O (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Er)} were prepared and characterized by elemental analysis, molar conductance, thermal analysis (TGA/DTGA), mass spectrometry (MS), Fourier transform infra-red (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Ln-L complexes are isostructural with four binding sites provided by two nitro groups along with four coordination sites for L...
August 17, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/28806512/painkiller-isoxicam-and-its-copper-complex-can-form-inclusion-complexes-with-different-cyclodextrins-a-fluorescence-fourier-transform-infrared-spectroscopy-and-nuclear-magnetic-resonance-study
#12
Sathi Goswami, Anupa Majumdar, Munna Sarkar
The interaction of a painkiller Isoxicam, belonging to the oxicam group of nonsteroidal anti-inflammatory drugs (NSAIDs) and its copper complex with different cyclodextrins (β-CD, γ-CD, HPβCD, and HPγCD), has been investigated in both solution and the solid state. Steady state and time-resolved fluorescence spectroscopy, fluorescence anisotropy, (1)H NMR, and FTIR spectroscopy are used. Both the drug and its copper complex form a host-guest inclusion complex with all CDs. Fluorescence spectroscopy is used to determine binding constants and stoichiometries of the host-guest complex...
August 29, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28797808/influence-of-buffer-solutions-in-the-adsorption-of-human-serum-proteins-onto-layered-double-hydroxide
#13
Diego R Gondim, Juan A Cecilia, Santângela O Santos, Thainá N B Rodrigues, José E Aguiar, Enrique Vilarrasa-García, Enrique Rodríguez-Castellón, Diana C S Azevedo, Ivanildo J Silva
The adsorption of human immunoglobulin G (IgG) and human serum albumin (HSA) on a non-calcined Mg-Al layered double hydroxide (3:1 Mg-Al LDH) was studied in batch and fixed bed experiments, focusing on the effect of buffer solution and pH over sorbent uptake. Mg-Al LDH was synthesized and characterized by X-ray diffraction (XRD), N2 adsorption-desorption isotherms at -196°C, X-ray photoelectron spectroscopy (XPS), Zero point charge (pHzpc), particle size distribution and Fourier transform infra-red (FTIR)...
August 7, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28792903/hydrocalumite-thin-films-for-polyphenol-biosensor-elaboration
#14
A Soussou, I Gammoudi, A Kalboussi, C Grauby-Heywang, T Cohen-Bouhacina, Z M Baccar
Hybrid thin films based on Hydrocalumite (Ca2AlCl layered double hydroxide LDH) and tyrosinase enzyme have been used for the elaboration of a high sensitive amperometric biosensor detecting polyphenols extracted from green tea. Structural properties of LDH nanomaterials were characterized by X-ray powder diffraction and Infra-Red spectroscopy, confirming its crystalline phase and chemical composition. Ca2AlCl-LDHs-thin films were deposited by spin-coating, and studied by Atomic Force Microscopy (AFM) to obtain information about the surface morphology of this host matrix before and after enzyme's immobilization...
August 7, 2017: IEEE Transactions on Nanobioscience
https://www.readbyqxmd.com/read/28783192/differentiating-between-long-and-short-range-disorder-in-infra-red-spectra-on-the-meaning-of-crystallinity-in-silica
#15
Yotam Asscher, Gregorio Dal Sasso, Luca Nodari, Ivana Angelini, Tiziana Boffa Ballaran, Gilberto Artioli
Local atomic disorder and crystallinity are structural properties that influence greatly the resulting chemical and mechanical properties of inorganic solids, and are used as indicators for different pathways of material formation. Here, these structural properties are assessed in the crystals of quartz based on particle-size-related scattering processes in transmission infra-red spectroscopy. Independent determinations of particle size distributions in the range 2-100 μm of a single crystal of quartz and defective quartz with highly anisotropic micro-crystallites show that particle sizes below the employed wavelength (approx 10 μm) exhibit asymmetric narrowing of absorption peak widths, due to scattering processes that depend on the intra-particle structural defects and long range crystallinity...
August 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28759638/influence-of-the-microwave-technology-on-solid-dispersions-of-mefenamic-acid-and-flufenamic-acid
#16
Sultan Alshehri, Faiyaz Shakeel, Mohamed Ibrahim, Ehab Elzayat, Mohammad Altamimi, Gamal Shazly, Kazi Mohsin, Musaed Alkholief, Bader Alsulays, Abdullah Alshetaili, Abdulaziz Alshahrani, Bander Almalki, Fars Alanazi
The present studies were undertaken to develop solvent-free solid dispersions (SDs) for poorly soluble anti-inflammatory drugs mefenamic acid (MA) and flufenamic acid (FFA) in order to enhance their in vitro dissolution rate and in vivo anti-inflammatory effects. The SDs of MA and FFA were prepared using microwaves irradiation (MW) technique. Different carriers such as Pluronic F127® (PL), Eudragit EPO® (EPO), polyethylene glycol 4000 (PEG 4000) and Gelucire 50/13 (GLU) were used for the preparation of SDs...
2017: PloS One
https://www.readbyqxmd.com/read/28745292/biomimetic-synthesis-of-agnps-from-penicillium-chrysogenum-strain-fgcc-bls1-by-optimising-physico-cultural-conditions-and-assessment-of-their-antimicrobial-potential
#17
Juhi Saxena, Pankaj Sharma, Abhijeet Singh
Biomimetic synthesis of metal nanoparticles (NPs) is safe and eco-friendly; therefore, find diverse applications. Considering this, the soil fungi Penicillium chrysogenum strain Fungal germplasm collection centre/ BLS1 was isolated, characterized and explored to synthesize extracellular silver NPs (AgNPs) under optimised conditions. The synthesis of AgNPs was investigated using ultraviolet (UV)-visible spectroscopy, Fourier-transform infra-red spectroscopy (FTIR), transmission electron microscope (TEM) and dynamic light scattering (DLS) analysis...
August 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28745291/biogenic-fabrication-of-cunps-cu-bioconjugates-and-in-vitro-assessment-of-antimicrobial-and-antioxidant-activity
#18
Raksha Pandit, Swapnil Gaikwad, Mahendra Rai
In the present study, the authors synthesised copper nanoparticles (CuNPs) by using extract of Zingiber officinale (ginger) and later the NPs were bioconjugated with nisin, which shows antimicrobial activity against food spoilage microorganisms. CuNPs and its bioconjugate were characterised by ultraviolet-vis spectroscopy, NP tracking analysis, Zetasizer, transmission electron microscopy analysis, X-ray diffraction and Fourier transform infra-red (FTIR) spectroscopy. Zeta potential of CuNPs and its bioconjugate were found to be very stable...
August 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28740154/ab-initio-density-functional-calculations-and-infra-red-study-of-co-interaction-with-pd-atoms-on-%C3%AE-al2o3-010-surface
#19
Chaitanya K Narula, Lawrence F Allard, Zili Wu
The ab initio density functional theoretical studies show that energetics favor CO oxidation on single Pd atoms supported on θ-alumina. The diffuse reflectance infra-red spectroscopy (DRIFTS) results show that carbonates are formed as intermediates when single supported Pd atoms are exposed to a gaseous mixture of CO + O2. The rapid agglomeration of Pd atoms under CO oxidation conditions even at 6 °C leads to the presence of Pd particles along with single atoms during CO oxidation experiments. Thus, the observed CO oxidation has contributions from both single Pd atoms and Pd particles...
July 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28737894/dual-role-of-gold-nanorods-inhibition-and-dissolution-of-a%C3%AE-fibrils-induced-by-near-ir-laser
#20
Swathi Sudhakar, Poornima Budime Santhosh, Ethayaraja Mani
Extracellular plaques of amyloid beta (Aβ) fibrils and neurofibrillary tangles are known to be associated with neurological diseases such as Alzheimer's disease. Studies have shown that spherical nanoparticles inhibit the formation of Aβ fibrils by intercepting the nucleation and growth pathways of fibrillation. In this report, gold nanorods (AuNRs) are used to inhibit the formation of Aβ fibrils and the shape-dependent plasmonic properties of AuNRs are exploited to faciliate faster dissolution of mature Aβ fibrils...
August 8, 2017: ACS Chemical Neuroscience
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