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https://www.readbyqxmd.com/read/28545205/organic-composition-and-multiphase-stable-isotope-analysis-of-active-degrading-and-restored-blanket-bog
#1
Laura McAnallen, Rory Doherty, Neil Ogle
Here we used organic composition and stable isotopic analysis to evaluate the effects of drainage and restoration at an ombrotrophic peatland, to assess whether rewetting of blanket bogs will reverse degradation. The organic composition of the peat and the isotopic fractionation between the solid (peat), liquid (pore water) and gas (soil gas) phases on actively accumulating, degrading and restored locations are compared. Fourier Transform Infrared Spectroscopy (FTIR) analysis of the organic material has shown a high level of humification (low decomposition) in the active peat...
May 20, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28544970/quantitative-chemical-imaging-with-stimulated-raman-scattering-microscopy
#2
REVIEW
Dan Fu
Chemical imaging plays an increasingly important role in studying heterogeneous biological systems. It combines molecular spectroscopy with high-resolution spatial information to create quantitative images of molecular distributions. Here I summarize recent progress in technical developments and biological applications of a specific chemical imaging technique-stimulated Raman scattering (SRS) microscopy. SRS microscopy allows for a wide range of molecules - both endogenous and exogenous - to be imaged at high spatial and temporal resolution in living cells, tissues, and organisms...
May 22, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28544963/fibronectin-based-multilayer-thin-films
#3
Adeline Gand, Maud Tabuteau, Coline Chat, Guy Ladam, Hassan Atmani, Paul R Van Tassel, Emmanuel Pauthe
Thin films mimicking the structure and composition of the extra-cellular matrix (ECM) are potentially attractive as biomaterials for cell contacting applications. Layer-by-layer (LbL) assembly of a biological polycation, poly(l-lysine) (PLL), and a common ECM protein, fibronectin (Fn), was employed here to construct nanoscale, ECM mimicking films. Incremental film thickness and interfacial charge magnitude are observed to diminish with layer number, resulting in sub-linear film growth scaling and saturation after about 10 layers...
May 10, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28544947/measuring-cortical-motor-hemodynamics-during-assisted-stepping-an-fnirs-feasibility-study-of-using-a-walker
#4
Andrea Cristina de Lima-Pardini, Guilherme A Zimeo Morais, Joana Bisol Balardin, Daniel Boari Coelho, Nametala Maia Azzi, Luis Augusto Teixeira, João Ricardo Sato
Walkers are commonly prescribed worldwide to individuals unable to walk independently. Walker usage leads to improved postural control and voluntary movement during step. In the present study, we aimed to provide a concept-proof on the feasibility of an event-related protocol integrating the analyses of biomechanical variables of step initiation and functional near-infrared spectroscopy (fNIRS) to measure activation of the supplementary motor area (SMA) while using a walker. Healthy young participants were tested while stepping with versus without the use of the walker...
May 17, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28544895/vibrational-spectroscopy-of-the-mass-selected-tetrahydrofurfuryl-alcohol-monomers-and-its-dimers-in-gas-phase-using-ir-depletion-and-vuv-single-photon-ionization
#5
Pengchao Wang, Yongjun Hu, Huaqi Zhan, Jiaxin Chen, Shan Jin, Wentao Song, Yujian Li
Tetrahydrofurfuryl alcohol (THFA, C5H10O2) is a close chemical analog of the sugar rings present in the phosphate-deoxyribose backbone structure of the nucleic acids. In present report, the infrared (IR) spectra of the size-selected THFA monomer and its dimer have been investigated in a pulsed supersonic jet using infrared-vacuum ultraviolet (VUV) ionization. Herein, the laser light at 118nm wavelength served as the source of "soft" ionization in a time-of-flight mass spectrometer. The IR features for the monomers located at 3622cm(-1) can be assigned to the intramolecular hydrogen bonding stretch vibrations mainly referring to A and C conformers...
May 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28544849/co-catalytic-effects-of-cos2-on-activity-of-mos2-catalyst-for-electrochemical-hydrogen-evolution
#6
Ranjith Bose, Zhenyu Jin, Seokhee Shin, Sungjoon Kim, Sun Young Lee, Yo-Sep Min
MoS2 is a promising material to replace Pt catalyst for electrochemical hydrogen evolution reaction (HER). It is well known that the activity of the MoS2 catalyst in the HER is significantly promoted by doping cobalt atoms. Recently, the Co-Mo-S phase, in which cobalt atoms decorate the edge positions of the MoS2 slabs, has been identified as a co-catalytic phase in the Co-doped MoS2 (Co-MoSx) with a low Co content. Here, we report the effect of the incorporation of cobalt atoms on the chemical state of Co-MoSx catalyst which gives rise to the co-catalytic effect...
May 25, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28544846/genomic-dna-interactions-mechanize-peptidotoxin-mediated-anti-cancer-nanotherapy
#7
Santosh K Misra, Aaron S Schwartz-Duval, Dipanjan Pan
Host defense peptides (HDPs) are a class of evolutionarily conserved substances of the innate immune response that has been identified as major players in the defense system in many living organisms. Some of the HDPs are also referred as peptidotoxins which offer immense potential for anti-cancer therapy. However, their therapeutic potential is yet to be fully translated mainly due to their off-target toxicity. Here we show that their nano-enabled delivery may become beneficial in controlling their delivery in intra-cellular space...
May 25, 2017: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/28544745/fs-laser-ablation-of-teeth-is-temperature-limited-and-provides-information-about-the-ablated-components
#8
Rebeca Ferraz de Menezes, Catherine Malinda Harvey, Marleny Elizabeth Márquez de Martínez Gerbi, Zachary J Smith, Dan Smith, Juan C Ivaldi, Alton Phillips, James W Chan, Sebastian Wachsmann-Hogiu
The goal of this work is to investigate the thermal effects of femtosecond laser (fs-laser) ablation for the removal of carious dental tissue. Additional studies identify different tooth tissues through femtosecond laser induced breakdown spectroscopy (fsLIBS) for the development of a feedback loop that could be utilized during ablation in a clinical setting. Scanning Election Microscope (SEM) images reveal that minimal morphological damages are incurred at repetition rates below the carbonization threshold of each tooth tissue...
May 24, 2017: Journal of Biophotonics
https://www.readbyqxmd.com/read/28544651/genetic-determination-of-body-fat-distribution-and-the-attributive-influence-on-metabolism
#9
Ellen Fehlert, Róbert Wagner, Caroline Ketterer, Anja Böhm, Jürgen Machann, Louise Fritsche, Fausto Machicao, Fritz Schick, Harald Staiger, Norbert Stefan, Hans-Ulrich Häring, Andreas Fritsche, Martin Heni
OBJECTIVE: Genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) associated with estimates of body fat distribution. Using predefined risk allele scores, the correlation of these scores with precisely quantified body fat distribution assessed by magnetic resonance (MR) imaging techniques and with metabolic traits was investigated. METHODS: Data from 4,944 MR scans from 915 subjects of European ancestry were analyzed. Body fat distribution was determined by MR imaging and liver fat content by (1) H-MR spectroscopy...
May 25, 2017: Obesity
https://www.readbyqxmd.com/read/28544641/reflectance-spectroscopy-to-shed-new-light-on-the-capillary-refill-test
#10
Rani Toll John, Joakim Henricson, Gert E Nilsson, Daniel Wilhelms, Chris D Anderson
To use Bioengineering methodology is used to achieve, at five anatomical sites, a detailed, quantitative assessment of the return of blood content to the blanched area, during the Capillary Refill (CR) test. An observational, non-randomized, experimental study on 23 healthy subjects (14 females) was performed in our climate controlled skin physiology laboratory. Our main outcome measures were based on the chronological assessment and quantification of red blood cell concentration (RBC) after the release of blanching pressure in the CR test, using Tissue Viability Imaging (TiVi), a digital photographic technique based on polarisation spectroscopy...
May 24, 2017: Journal of Biophotonics
https://www.readbyqxmd.com/read/28544634/hydrogen-bond-driven-self-assembly-between-amidinium-cations-and-carboxylate-anions-a-combined-molecular-dynamics-nmr-spectroscopy-and-single-crystal-x-ray-diffraction-study
#11
Michael Thomas, Thomas Anglim Lagones, Martyna Judd, Mahbod Morshedi, Megan L O'Mara, Nicholas G White
A combination of molecular dynamics (MD), NMR spectroscopy, and single crystal X-ray diffraction (SCXRD) techniques was used to probe the self-assembly of para- and meta-bis(amidinium) compounds with para-, meta-, and ortho-dicarboxylates. Good concordance was observed between the MD and experimental results. In DMSO solution, the systems form several rapidly exchanging assemblies, in part because a range of hydrogen bonding interactions is possible between the amidinium and carboxylate moieties. Upon crystallization, the majority of the systems form 1D supramolecular polymers, which are held together by short N-H⋅⋅⋅O hydrogen bonds...
May 23, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28544565/base-selective-five-versus-six-membered-ring-annulation-in-palladium-catalyzed-c-c-coupling-cascade-reactions-new-access-to-electron-poor-polycyclic-aromatic-dicarboximides
#12
Sabine Seifert, David Schmidt, Kazutaka Shoyama, Frank Würthner
Palladium-catalyzed base-selective annulation of dibromonaphthalimide to different aryl boronate esters by combined Suzuki-Miyaura cross-coupling and direct C-H arylation afforded a series of new five- and six-membered ring annulated electron-poor polycyclic aromatic hydrocarbons. Cesium carbonate (Cs2 CO3 ) as auxiliary base in these C-C coupling cascade reactions led exclusively to six-membered ring annulation, while the use of organic base diazabicycloundecene (DBU) afforded the corresponding five-membered ring annulated products...
May 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544514/dynamic-enhancer-function-in-the-chromatin-context
#13
REVIEW
Ido Goldstein, Gordon L Hager
Enhancers serve as critical regulatory elements in higher eukaryotic cells. The characterization of enhancer function has evolved primarily from genome-wide methodologies, including chromatin immunoprecipitation (ChIP-seq), DNase-I hypersensitivity (DNase-seq), digital genomic footprinting (DGF), and the chromosome conformation capture techniques (3C, 4C, and Hi-C). These population-based assays average signals across millions of cells and lead to enhancer models characterized by static and sequential binding...
May 22, 2017: Wiley Interdisciplinary Reviews. Systems Biology and Medicine
https://www.readbyqxmd.com/read/28544372/deprotonation-of-a-seemingly-hydridic-diborane-6-to-build-a-b-b-bond
#14
Thomas Kaese, Hendrik Budy, Michael Bolte, Hans-Wolfram Lerner, Matthias Wagner
Deprotonation of the doubly arylene-bridged diborane(6) derivative 1H2 with (Me3 Si)3 CLi or (Me3 Si)2 NK gives the B-B σ-bonded species M[1H] in essentially quantitative yields (THF, room temperature; M=Li, K, arylene=4,4'-di-tert-butyl-2,2'-biphenylylene). With nBuLi as the base, the yield of Li[1H] drops to 20 % and the 1,1-bis(9-borafluorenyl)butane Li[2H] is formed as a side product (30 %). In addition to the 1,1-butanediyl fragment, the two boron atoms of Li[2H] are linked by a μ-H bridge. In the closely related molecule Li[3H], the corresponding μ-H atom can be abstracted with (Me3 Si)3 CLi to afford the B-B-bonded conjugated base Li2 [3] (THF, 150 °C; 15 %)...
May 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544304/strong-improvement-of-long-term-chemical-and-thermal-stability-of-plasmonic-silver-nanoantennas-and-films
#15
Xiaolong Wang, Christian Santschi, Olivier J F Martin
Silver (Ag) nanostructures and thin films are advantageous plasmonic materials as they have significantly lower losses than gold (Au). Unfortunately, Ag nanostructures suffer from poor chemical and thermal stability, which limit their applications. Here, the mechanisms leading to the deterioration of Ag nanostructures are clarified. It is first shown that oxygen alone cannot oxidize Ag nanostructures. Then, experiments using X-ray photoelectron spectroscopy reveal that the amount of sulfur in ambient air is too low for efficient tarnishing of the Ag surface...
May 24, 2017: Small
https://www.readbyqxmd.com/read/28544248/end-functionalized-palladium-scs-pincer-polymers-via-controlled-radical-polymerizations
#16
Diane S Lye, Aaron E Cohen, Madeleine Z Wong, Marcus Weck
A direct and facile route toward semitelechelic polymers, end-functionalized with palladated sulfur-carbon-sulfur pincer (Pd(II) -pincer) complexes is reported that avoids any post-polymerization step. Key to our methodology is the combination of reversible addition-fragmentation chain-transfer (RAFT) polymerization with functionalized chain-transfer agents. This strategy yields Pd end-group-functionalized materials with monomodal molar mass dispersities (Đ) of 1.18-1.44. The RAFT polymerization is investigated using a Pd(II) -pincer chain-transfer agent for three classes of monomers: styrene, tert-butyl acrylate, and N-isopropylacrylamide...
May 22, 2017: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/28544208/ultra-high-field-magnetic-resonance-spectroscopy-in-non-alcoholic-fatty-liver-disease-novel-mechanistic-and-diagnostic-insights-of-energy-metabolism-in-non-alcoholic-steatohepatitis-and-advanced-fibrosis
#17
Stefan Traussnigg, Christian Kienbacher, Martin Gajdošík, Ladislav Valkovič, Emina Halilbasic, Judith Stift, Christian Rechling, Harald Hofer, Petra Steindl-Munda, Peter Ferenci, Fritz Wrba, Siegfried Trattnig, Martin Krššák, Michael Trauner
BACKGROUND & AIMS: With the rising prevalence of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) non-invasive tools obtaining pathomechanistic insights to improve risk stratification are urgently needed. We therefore explored high- and ultra-high-field magnetic resonance spectroscopy (MRS) to obtain novel mechanistic and diagnostic insights into alterations of hepatic lipid, cell membrane and energy metabolism across the spectrum of NAFLD. METHODS: MRS and liver biopsy were performed in 30 NAFLD patients with NAFL (n=8) or NASH (n=22)...
April 24, 2017: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/28544203/observation-of-ch%C3%A2-%C3%A2-%C3%A2-%C3%AF-interactions-between-methyl-and-carbonyl-groups-in-proteins
#18
Frédéric A Perras, Dominique Marion, Jérôme Boisbouvier, David L Bryce, Michael J Plevin
Protein structure and function is dependent on myriad noncovalent interactions. Direct detection and characterization of these weak interactions in large biomolecules, such as proteins, is experimentally challenging. Herein, we report the first observation and measurement of long-range "through-space" scalar couplings between methyl and backbone carbonyl groups in proteins. These J couplings are indicative of the presence of noncovalent C-H⋅⋅⋅π hydrogen-bond-like interactions involving the amide π network...
May 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544178/transition-metal-nitride-core-noble-metal-shell-nanoparticles-as-highly-co-tolerant-catalysts
#19
Aaron Garg, Maria Milina, Madelyn Ball, Daniela Zanchet, Sean T Hunt, James A Dumesic, Yuriy Roman-Leshkov
Core-shell architectures offer an effective way to tune and enhance the properties of noble metal catalysts. Here, we demonstrate the synthesis of Pt shell on titanium tungsten nitride core nanoparticles (Pt/TiWN) by high temperature ammonia nitridation of a parent core-shell carbide material (Pt/TiWC). X-ray photoelectron spectroscopy revealed significant core-level shifts for Pt shells supported on TiWN cores, corresponding to increased stabilization of the Pt valence d-states. The modulation of the electronic structure of the Pt shell by the nitride core translated into enhanced CO tolerance during hydrogen electrooxidation in the presence of CO...
May 25, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544115/unprecedented-carbon-signal-enhancement-in-liquid-state-nmr-spectroscopy
#20
György Pintér, Harald Schwalbe
We shall overcome: As a result of efforts to overcome the sensitivity challenge of liquid-state NMR spectroscopy, a thousand-fold signal enhancement was achieved by dynamic nuclear polarization (DNP) for (13) C signals at high magnetic field (3.4 T) and room temperature, thereby exceeding the predicted limitations of high-field liquid-state in situ DNP.
May 23, 2017: Angewandte Chemie
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