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https://www.readbyqxmd.com/read/28230536/p-channel-thin-film-transistors-using-reduced-graphene-oxide
#1
Somnath Chakraborty, A N Resmi, Renuka Pothuraju, K B Jinesh
Chemically reduced graphene oxide (rGO) samples with various degree of reduction were prepared using hydrazine hydrate as the reducing agent. Scanning tunnelling microscope (STM) imaging shows that rGO contains rows of randomly distributed patches of epoxy groups. The local density of states (LDOS) of the rGO samples were mapped with scanning tunnelling spectroscopy (STS), which shows that the bandgap in rGO originates from the epoxide regions itself. The Fermi level of the epoxide regions is shifted towards the valence band, making rGO locally p-type and a ranges of bandgaps from 0-2...
February 23, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28230348/nmr-structures-of-gcn4p-are-largely-conserved-when-ion-pairs-are-disrupted-at-acidic-ph-but-show-a-relaxation-of-the-coiled-coil-superhelix
#2
Anne R Kaplan, Megan R Brady, Mark W Maciejewski, Richard A Kammerer, Andrei T Alexandrescu
To understand the roles ion pairs play in stabilizing coiled coils we determined NMR structures of GCN4p at three pH values. At pH 6.6 all acidic residues are fully charged, at pH 4.4 they are half-charged, and at pH 1.5 they are protonated and uncharged. The α-helix monomer and coiled coil structures of GCN4p are largely conserved, except for a loosening of the coiled coil quaternary structure with decreasing pH. Differences going from neutral to acidic pH include (i) an unwinding of the coiled coil superhelix due to the loss of inter-chain ion pair contacts, (ii) a small increase in the separation of the monomers in the dimer, (iii) a loosening of knobs-into-holes packing motifs, and (iv) an increased separation between oppositely charged residues that participate in ion pairs at neutral pH...
February 23, 2017: Biochemistry
https://www.readbyqxmd.com/read/28225653/update-on-ct-and-mri-of-adrenal-nodules
#3
Nicola Schieda, Evan S Siegelman
OBJECTIVE: The objective of this article is to review the current role of CT and MRI for the characterization of adrenal nodules. CONCLUSION: Unenhanced CT and chemical-shift MRI have high specificity for lipid-rich adenomas. Dual-energy CT provides comparable to slightly lower sensitivity for the diagnosis of lipid-rich adenomas but may improve characterization of lipid-poor adenomas. Nonadenomas containing intracellular lipid pose an imaging challenge; however, nonadenomas that contain lipid may be potentially diagnosed using other imaging features...
February 22, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28224616/critical-cholangiocarcinogenesis-control-by-cryptochrome-clock-genes
#4
Ali Mteyrek, Elisabeth Filipski, Catherine Guettier, Malgorzata Oklejewicz, Gijsbertus T J van der Horst, Alper Okyar, Francis Lévi
A coordinated network of molecular circadian clocks in individual cells generates 24-hour rhythms in liver metabolism and proliferation. Circadian disruption through chronic jet lag or Per2 clock gene mutation was shown to accelerate hepatocarcinoma development in mice. Since divergent effects were reported for clock genes Per and Cry regarding xenobiotic toxicity, we questioned the role of Cry1 and Cry2 in liver carcinogenesis. Male WT and Cry1(-/-) Cry2(-/-) mice (C57Bl/6 background) were chronically exposed to diethylnitrosamine (DEN) at ZT11...
February 22, 2017: International Journal of Cancer. Journal International du Cancer
https://www.readbyqxmd.com/read/28224130/-1-h-nmr-spectra-dataset-and-solid-state-nmr-data-of-cowpea-vigna-unguiculata
#5
Elenilson G Alves Filho, Lorena M A Silva, Elizita M Teofilo, Flemming H Larsen, Edy S de Brito
In this article the NMR data from chemical shifts, coupling constants, and structures of all the characterized compounds were provided, beyond a complementary PCA evaluation for the corresponding manuscript (E.G. Alves Filho, L.M.A. Silva, E.M. Teofilo, F.H. Larsen, E.S. de Brito, 2017) [3]. In addition, a complementary assessment from solid-state NMR data was provided. For further chemometric analysis, numerical matrices from the raw (1)H NMR data were made available in Microsoft Excel workbook format (.xls)...
April 2017: Data in Brief
https://www.readbyqxmd.com/read/28223517/heart-failure-drug-changes-the-mechanoenzymology-of-the-cardiac-myosin-powerstroke
#6
John A Rohde, David D Thomas, Joseph M Muretta
Omecamtiv mecarbil (OM), a putative heart failure therapeutic, increases cardiac contractility. We hypothesize that it does this by changing the structural kinetics of the myosin powerstroke. We tested this directly by performing transient time-resolved FRET on a ventricular cardiac myosin biosensor. Our results demonstrate that OM stabilizes myosin's prepowerstroke structural state, supporting previous measurements showing that the drug shifts the equilibrium constant for myosin-catalyzed ATP hydrolysis toward the posthydrolysis biochemical state...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28220693/aroma-precursors-in-grapes-and-wine-flavor-release-during-wine-production-and-consumption
#7
Mango Parker, Dimitra L Capone, I Leigh Francis, Markus J Herderich
Pioneering investigations into precursors to fruity and floral flavors established the importance of terpenoid and C13-norisoprenoid glycosides to the flavor of aromatic wines. Nowadays flavor precursors in grapes and wine are known to be structurally diverse, encompassing glycosides; amino acid conjugates; odorless volatiles; hydroxycinnamic acids and many others. Flavor precursors mainly originate in the grape berry, but also from oak or other materials involved in winemaking. Flavors are released from precursors during crushing and subsequent production steps by enzymatic and non-enzymatic transformations, via microbial glycosidases; esterases; C-S lyases and decarboxylases; and through acid catalysed hydrolysis and chemical rearrangements...
February 21, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28218508/control-of-surface-and-edge-oxidation-on-phosphorene
#8
Kaci L Kuntz, Rebekah A Wells, Jun Hu, Teng Yang, Baojuan Dong, Huaihong Guo, Adam H Woomer, Daniel L Druffel, Anginelle Alabanza, David Tomanek, Scott C Warren
Phosphorene is emerging as an important two-dimensional semiconductor, but controlling the surface chemistry of phosphorene remains a significant challenge. Here we show that controlled oxidation of phosphorene determines the composition and spatial distribution of the resulting oxide. We used X-ray photoemission spectroscopy to measure the binding energy shifts that accompany oxidation. We interpreted these spectra by calculating the binding energy shift for 24 likely bonding configurations, including phosphorus oxides and hydroxides located on the basal surface or edges of flakes...
February 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28218294/correlated-electron-nuclear-dynamics-in-above-threshold-multiphoton-ionization-of-asymmetric-molecule
#9
Zhuo Wang, Min Li, Yueming Zhou, Pengfei Lan, Peixiang Lu
The partition of the photon energy into the subsystems of molecules determines many photon-induced chemical and physical dynamics in laser-molecule interactions. The electron-nuclear energy sharing from multiphoton ionization of molecules has been used to uncover the correlated dynamics of the electron and fragments. However, most previous studies focus on symmetric molecules. Here we study the electron-nuclear energy sharing in strong-field photoionization of HeH(2+) by solving the one-dimensional time-dependent Schrödinger equation (TDSE)...
February 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28216664/iron-isotopic-fractionation-between-silicate-mantle-and-metallic-core-at-high-pressure
#10
Jin Liu, Nicolas Dauphas, Mathieu Roskosz, Michael Y Hu, Hong Yang, Wenli Bi, Jiyong Zhao, Esen E Alp, Justin Y Hu, Jung-Fu Lin
The +0.1‰ elevated (56)Fe/(54)Fe ratio of terrestrial basalts relative to chondrites was proposed to be a fingerprint of core-mantle segregation. However, the extent of iron isotopic fractionation between molten metal and silicate under high pressure-temperature conditions is poorly known. Here we show that iron forms chemical bonds of similar strengths in basaltic glasses and iron-rich alloys, even at high pressure. From the measured mean force constants of iron bonds, we calculate an equilibrium iron isotope fractionation between silicate and iron under core formation conditions in Earth of ∼0-0...
February 20, 2017: Nature Communications
https://www.readbyqxmd.com/read/28216663/the-importance-of-pollen-chemistry-in-evolutionary-host-shifts-of-bees
#11
Maryse Vanderplanck, Nicolas J Vereecken, Laurent Grumiau, Fabiana Esposito, Georges Lognay, Ruddy Wattiez, Denis Michez
Although bee-plant associations are generally maintained through speciation processes, host shifts have occurred during evolution. Understanding shifts between both phylogenetically and morphologically unrelated plants (i.e., host-saltation) is especially important since they could have been key processes in the origin and radiation of bees. Probably far from being a random process, such host-saltation might be driven by hidden constraints associated with plant traits. We selected two clades of oligolectic bees (i...
February 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28216452/water-and-lipid-diffusion-mri-using-chemical-shift-displacement-based-separation-of-lipid-tissue-split
#12
Naoki Ohno, Hirohito Kan, Tosiaki Miyati, Toshitaka Aoki, Shota Ishida, Toshifumi Gabata
PURPOSE: To obtain water and lipid diffusion-weighted images (DWIs) simultaneously, we devised a novel method utilizing chemical shift displacement-based separation of lipid tissue (SPLIT) imaging. MATERIALS AND METHODS: Single-shot diffusion echo-planar imaging without fat suppression was used and the imaging parameters were optimized to separate water and lipid DWIs by chemical shift displacement of the lipid signals along the phase-encoding direction. Using the optimized conditions, transverse DWIs at the maximum diameter of the right calf were scanned with multiple b-values in five healthy subjects...
February 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28216036/-1-h-csa-parameters-by-ultrafast-mas-nmr-measurement-and-applications-to-structure-refinement
#13
Habeeba K Miah, Rosalie Cresswell, Dinu Iuga, Jeremy J Titman
A (1)H anisotropic-isotropic chemical shift correlation experiment which employs symmetry-based recoupling sequences to reintroduce the chemical shift anisotropy in ν1 and ultrafast MAS to resolve (1)H sites in ν2 is described. This experiment is used to measure (1)H shift parameters for L-ascorbic acid, a compound with a relatively complex hydrogen-bonding network in the solid. The (1)H CSAs of hydrogen-bonded sites with resolved isotropic shifts can be extracted directly from the recoupled lineshapes. In combination with DFT calculations, hydrogen positions in crystal structures obtained from X-ray and neutron diffraction are refined by comparison with simulations of the full two-dimensional NMR spectrum...
February 13, 2017: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/28215898/influence-of-lactobacillus-plantarum-on-yogurt-fermentation-properties-and-subsequent-changes-during-postfermentation-storage
#14
Changkun Li, Jihong Song, Lai-Yu Kwok, Jicheng Wang, Yan Dong, Haijing Yu, Qiangchuan Hou, Heping Zhang, Yongfu Chen
This study aimed to evaluate the influence of 9 Lactobacillus plantarum with broad-spectrum antibacterial activity on fermented milk, including changes to the fermentation characteristics (pH, titration acidity, and viable counts), texture profile, relative content of volatile compounds, and sensory evaluation during 28-d storage at 4°C. First, L. plantarum IMAU80106, IMAU10216, and IMAU70095 were selected as candidates for further study because of their excellent coagulation and proteolytic activities. Subsequently, these L...
February 16, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28215500/environmental-epigenomics-current-approaches-to-assess-epigenetic-effects-of-endocrine-disrupting-compounds-edc-s-on-human-health
#15
REVIEW
Natalia Tapia-Orozco, Gerardo Santiago-Toledo, Valeria Barrón, Ana María Espinosa-García, José Antonio García-García, Roeb García-Arrazola
Environmental Epigenomics is a developing field to study the epigenetic effect on human health from exposure to environmental factors. Endocrine disrupting chemicals have been detected primarily in pharmaceutical drugs, personal care products, food additives, and food containers. Exposure to endocrine-disrupting chemicals (EDCs) has been associated with a high incidence and prevalence of many endocrine-related disorders in humans. Nevertheless, further evidence is needed to establish a correlation between exposure to EDC and human disorders...
February 10, 2017: Environmental Toxicology and Pharmacology
https://www.readbyqxmd.com/read/28215085/peptide-functionalized-gold-nanoparticles-as-a-stimuli-responsive-contrast-medium-in-multi-photon-microscopy
#16
Johan Borglin, Robert Selegård, Daniel Aili, Marica B Ericson
There is a need for biochemical contrast mediators with high signal to noise ratios enabling non-invasive biomedical sensing, e.g., for neural sensing, protein-protein interactions, in addition to cancer diagnostics. The translational challenge is to develop a biocompatible approach ensuring high biochemical contrast while avoiding a raise of the background signal. We here present a concept where gold nanoparticles (AuNPs) can be utilized as a stimuli responsive contrast medium by chemically triggering their ability to exhibit multiphoton induced luminescence (MIL) when performing multi-photon laser scanning microscopy (MPM)...
February 20, 2017: Nano Letters
https://www.readbyqxmd.com/read/28214127/functionalized-superparamagnetic-iron-oxide-nanoparticles-provide-highly-efficient-iron-labeling-in-macrophages-for-magnetic-resonance-based-detection-in-vivo
#17
Jack Sharkey, Philip J Starkey Lewis, Michael Barrow, Salamah M Alwahsh, June Noble, Eilidh Livingstone, Ross J Lennen, Maurits A Jansen, Jaime Garcia Carrion, Neill Liptrott, Shareen Forbes, Dave J Adams, Amy E Chadwick, Stuart J Forbes, Patricia Murray, Matthew J Rosseinsky, Christopher E Goldring, B Kevin Park
BACKGROUND AIMS: Tracking cells during regenerative cytotherapy is crucial for monitoring their safety and efficacy. Macrophages are an emerging cell-based regenerative therapy for liver disease and can be readily labeled for medical imaging. A reliable, clinically applicable cell-tracking agent would be a powerful tool to study cell biodistribution. METHODS: Using a recently described chemical design, we set out to functionalize, optimize and characterize a new set of superparamagnetic iron oxide nanoparticles (SPIONs) to efficiently label macrophages for magnetic resonance imaging-based cell tracking in vivo...
February 15, 2017: Cytotherapy
https://www.readbyqxmd.com/read/28213793/automation-of-peak-tracking-analysis-of-stepwise-perturbed-nmr-spectra
#18
Tommaso Banelli, Marco Vuano, Federico Fogolari, Andrea Fusiello, Gennaro Esposito, Alessandra Corazza
We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track (TINT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered...
February 17, 2017: Journal of Biomolecular NMR
https://www.readbyqxmd.com/read/28211935/the-vertical-location-of-%C3%AE-tocopherol-in-phosphatidylcholine-membranes-is-not-altered-as-a-function-of-the-degree-of-unsaturation-of-the-fatty-acyl-chains
#19
Alessio Ausili, Ana M de Godos, Alejandro Torrecillas, Francisco J Aranda, Senena Corbalán-García, Juan C Gómez-Fernández
α-Tocopherol is a natural preservative that prevents free radical chain oxidations in biomembranes. We have studied the location of α-tocopherol in model membranes formed by different unsaturated phosphatidylcholines, namely 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine (PLPC), 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (PAPC) and 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (PDPC). Small angle X-ray diffraction revealed that α-tocopherol was well mixed with all the phospholipids...
February 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28209339/vitamin-e-stabilized-highly-crosslinked-polyethylenes-the-role-and-effectiveness-in-total-hip-arthroplasty
#20
Kengo Yamamoto, Toshiyuki Tateiwa, Yasuhito Takahashi
Morphology and design of ultra-high molecular weight polyethylene (UHMWPE or simply PE) acetabular components used in total hip arthroplasty (THA) have been evolving for more than half a century. Since the late-1990s, there were two major technological innovations in PE emerged from necessity to overcome the wear-induced periprosthetic osteolysis, i.e., the development of highly crosslinked PEs (HXLPEs). There are many literature reporting that radiation crosslinked and remelted/annealed (first-generation) HXLPEs markedly reduced the incidence of osteolysis and aseptic loosening...
February 10, 2017: Journal of Orthopaedic Science: Official Journal of the Japanese Orthopaedic Association
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