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https://www.readbyqxmd.com/read/28102938/low-energy-catalytic-electrolysis-for-simultaneously-hydrogen-evolution-and-lignin-depolymerization
#1
Xu Du, Wei Liu, Zhe Zhang, Arie Mulyadi, Alex Brittain, Jian Gong, Yulin Deng
Hereby we present a novel proton exchange membrane (PEM) electrolysis process in which lignin was used as the hydrogen source at anode for hydrogen production. Either polyoxometalate (POM) or FeCl3 was used as the catalysts and charge transfer agents in anode. Over 90% Faraday efficiency was achieved. In a thermal insulation reactor, the heat energy can be maintained at a very low stage for continuous operation. Compared to the best alkaline water electrolysis reported in literature, the electrical energy consumption could be 40% lower with novel lignin electrolysis method...
January 19, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28102858/luminescent-immunoprecipitation-system-lips-for-detection-of-autoantibodies-against-atp4a-and-atp4b-subunits-of-gastric-proton-pump-h-k-atpase-in-atrophic-body-gastritis-patients
#2
Edith Lahner, Cristina Brigatti, Ilaria Marzinotto, Marilia Carabotti, Giulia Scalese, Howard W Davidson, Janet M Wenzlau, Emanuele Bosi, Lorenzo Piemonti, Bruno Annibale, Vito Lampasona
OBJECTIVES: Circulating autoantibodies targeting the H+/K+-ATPase proton pump of gastric parietal cells are considered markers of autoimmune gastritis, whose diagnostic accuracy in atrophic body gastritis, the pathological lesion of autoimmune gastritis, remains unknown. This study aimed to assess autoantibodies against ATP4A and ATP4B subunits of parietal cells H+, K+-ATPase in atrophic body gastritis patients and controls. METHODS: One-hundred and four cases with atrophic body gastritis and 205 controls were assessed for serological autoantibodies specific for ATP4A or ATP4B subunits using luminescent immunoprecipitation system (LIPS)...
January 19, 2017: Clinical and Translational Gastroenterology
https://www.readbyqxmd.com/read/28102675/mechanistic-elucidation-of-zirconium-catalyzed-direct-amidation
#3
Helena Lundberg, Fredrik Tinnis, Jiji Zhang, Andrés G Algarra, Fahmi Himo, Hans Adolfsson
The mechanism of the zirconium-catalyzed condensation of carboxylic acids and amines for direct formation of amides was studied using kinetics, NMR-spectroscopy and DFT-calculations. The reaction is found to be first order with respect to catalyst and has a positive rate dependence on amine concentration and a negative rate dependence on carboxylic acid concentration. Kinetic experiments using Reaction Progress Kinetic Analysis (RPKA) protocols demonstrate that inhibition of the catalyst by the amide product can be avoided using a high amine concentration...
January 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28102412/organobase-catalyzed-1-2-brook-rearrangement-of-silyl-glyoxylates
#4
Man-Yi Han, Fei-Yan Yang, Di Zhou, Zhigang Xu
A highly efficient [1,2]-Brook rearrangement of silyl glyoxylates has been developed using DBU as the organobase-catalyst. This [1,2]-Brook rearrangement is applicable to a number of thiols and secondary phosphine oxides containing acidic protons. These nucleophiles afford the corresponding Brook products in high yields. Using this methodology, a formal synthesis of anti-HIV drug compound lamivudine was realized.
January 19, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28102392/dynamics-of-the-o-h2-%C3%A2-oh-h-oh-h-proton-and-hydrogen-atom-transfer-reactions-on-the-two-lowest-potential-energy-surfaces
#5
Rodrigo Martínez, Miguel Paniagua, Jordi Mayneris-Perxachs, Pablo Gamallo, Miguel González
The dynamics of the title reaction was studied using mainly the quasiclassical trajectory (QCT) method on the ground 1(2)A'' (OH(+) channel) and first excited 1(2)A' (OH channel) potential energy surfaces (PESs) employing ab initio analytical representations of the PESs developed by us. Both PESs correspond to exoergic reactions, are barrierless and present a deep minimum along the minimum energy path (MEP). Some extra calculations (cross sections) were also performed with the time dependent quantum real wave packet method at the centrifugal sudden level (RWP-CS method)...
January 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28102391/enhancement-in-catalytic-proton-reduction-by-an-internal-base-in-a-diiron-pentacarbonyl-complex-its-synthesis-characterisation-inter-conversion-and-electrochemical-investigation
#6
Zhimei Li, Zhiyin Xiao, Fenfen Xu, Xianghua Zeng, Xiaoming Liu
The reaction of a tripodal ligand (H2L) with a {S2N} donor-set with tri-iron dodecacarbonyl in toluene leads to the isolation of a diiron pentacarbonyl complex 1 as a model for the sub-site of the [FeFe]-hydrogenase. Protonation of this complex under CO (1 atm.) forms quantitatively the hexacarbonyl complex 2H+ with a pendant pyridinium group. Infrared spectroscopic investigations indicate that its pendant pyridinium group dissociates to give hexacarbonyl complex 2 which forms subsequently the pentacarbonyl complex 1...
January 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28102390/reactions-in-silicon-nitrogen-plasma
#7
Goran Kovačević, Branko Pivac
Reaction mechanisms that lead to creation of silicon-nitrogen bonds are studied in detail. These reactions are of fundamental importance for silicon nitride synthesis by plasma enhanced chemical vapour deposition from the gas mixture of silane (SiH4) and ammonia (NH3). All reactions in SiH4-NH3 plasma can be categorised as some of the basic types of reactions: bond dissociation, neutral nucleophilic substitution, radical neutralisation, neutral-radical addition, silylene addition, silylene rearrangement, radical nucleophilic addition or hydrogen abstraction reaction...
January 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28102361/effectiveness-and-tolerability-of-different-recommended-doses-of-ppis-and-h2ras-in-gerd-network-meta-analysis-and-grade-system
#8
Chao Zhang, Joey S W Kwong, Rui-Xia Yuan, Hao Chen, Chang Xu, Yi-Pin Wang, Gong-Li Yang, Jin-Zhu Yan, Le Peng, Xian-Tao Zeng, Hong Weng, Jie Luo, Yu-Ming Niu
Proton pump inhibitors (PPIs) and histamine-2-receptor antagonists (H2RAs) are used for gastro-esophageal reflux disease (GERD); however, the clinical evidence for treatment is poor. We evaluated the effectiveness and tolerability of different doses of PPIs, H2RAs and placebo in adults with GERD. Six online databases were searched through September 1, 2016. All related articles were included and combined with a Bayesian network meta-analysis from randomized controlled trials (RCTs). The GRADE systems were employed to assess the main outcome...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101705/tyrosine-kinase-inhibitors-and-proton-pump-inhibitors-an-evaluation-of-treatment-options
#9
Roelof W F van Leeuwen, Frank G A Jansman, Nicole G Hunfeld, Robert Peric, Anna K L Reyners, Alex L T Imholz, Jacobus R B J Brouwers, Joachim G Aerts, Teun van Gelder, Ron H J Mathijssen
Tyrosine kinase inhibitors (TKIs) have rapidly become an established factor in oncology, and have been shown to be effective in a wide variety of solid and hematologic malignancies. Use of the oral administration route of TKIs offers flexibility and is convenient for the patient; however, despite these advantages, the oral route of administration also causes a highly relevant new problem. Acid-inhibitory drugs, such as proton pump inhibitors (PPIs), increase the intragastric pH, which may subsequently decrease TKI solubility, bioavailability, and treatment efficacy...
January 18, 2017: Clinical Pharmacokinetics
https://www.readbyqxmd.com/read/28101574/nek2-serves-as-a-prognostic-biomarker-for-hepatocellular-carcinoma
#10
Gang Li, Yanping Zhong, Qingrong Shen, Yi Zhou, Xiaofang Deng, Cuiping Li, Jiagui Chen, Ying Zhou, Min He
Never in mitosis gene A (NIMA)-related kinase 2 (NEK2) is a microtubule-associated protein that regulates spindle assembly in human cells and is overexpressed in various malignancies. However, the role of NEK2 in hepatocellular carcinoma (HCC) remains undetermined. We performed RNA-seq of the HCC cell line SMMC-7721 and the normal liver cell line HL-7702 using the Ion Proton System. NEK2 expression was detected using quantitative reverse transcription polymerase chain reaction in two cell lines and 5 matched HCC and adjacent non-tumorous liver tissues...
February 2017: International Journal of Oncology
https://www.readbyqxmd.com/read/28100493/large-14c-excursion-in-5480-bc-indicates-an-abnormal-sun-in-the-mid-holocene
#11
Fusa Miyake, A J Timothy Jull, Irina P Panyushkina, Lukas Wacker, Matthew Salzer, Christopher H Baisan, Todd Lange, Richard Cruz, Kimiaki Masuda, Toshio Nakamura
Radiocarbon content in tree rings can be an excellent proxy of the past incoming cosmic ray intensities to Earth. Although such past cosmic ray variations have been studied by measurements of (14)C contents in tree rings with ≥10-y time resolution for the Holocene, there are few annual (14)C data. There is a little understanding about annual (14)C variations in the past, with the exception of a few periods including the AD 774-775 (14)C excursion where annual measurements have been performed. Here, we report the result of (14)C measurements using the bristlecone pine tree rings for the period from 5490 BC to 5411 BC with 1- to 2-y resolution, and a finding of an extraordinarily large (14)C increase (20‰) from 5481 BC to 5471 BC (the 5480 BC event)...
January 18, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28100079/a-novel-proton-transfer-salt-of-2-amino-6-sulfamoylbenzothiazole-and-its-metal-complexes-the-evaluation-of-their-inhibition-effects-on-human-cytosolic-carbonic-anhydrases
#12
Zeynep Alkan Alkaya, Halil İlkimen, Cengiz Yenikaya, Yasemin Kaygısız, Metin Bülbül, Tuncay Tunç, Musa Sarı
A novel proton transfer compound (SMHABT)(+)(HDPC)(-) (1) obtained from 2-amino-6-sulfamoylbenzothiazole (SMABT) and 2,6-pyridinedicarboxylic acid (H2DPC) and its Fe(III), Co(II), Ni(II) complexes (2-4), and Fe(II) complex of SMABT (5) have been prepared and characterized by spectroscopic techniques. Additionally, single crystal X-ray diffraction techniques were applied to complexes (2-4). All complexes (2-4) have distorted octahedral conformations and the structure of 5 might be proposed as octahedral according to spectral and analytical results...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
https://www.readbyqxmd.com/read/28100053/the-grateful-infrared-sequential-protein-structural-changes-resolved-by-infrared-difference-spectroscopy
#13
Tilman Kottke, Víctor A Lórenz-Fonfría, Joachim Heberle
The catalytic activity of proteins is a function of structural changes. Very often these are as minute as protonation changes, hydrogen bonding changes, and amino acid side chain reorientations. To resolve these, a methodology is afforded that not only provides the molecular sensitivity but allows for tracing the sequence of these hierarchical reactions at the same time. This feature article showcases results from time-resolved IR spectroscopy on channelrhodopsin (ChR), light-oxygen-voltage (LOV) domain protein, and cryptochrome (CRY)...
January 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28099164/investigation-of-time-resolved-proton-radiography-using-x-ray-flat-panel-imaging-system
#14
Kyung-Wook Jee, Rongxiao Zhang, El Bentefour, Paul Doolan, Ethan Cascio, Gregory Sharp, Jacob Flanz, Hsiao-Ming Lu
Proton beam therapy benefits from the Bragg peak and delivers highly conformal dose distributions. However, the location of the end-of-range is subject to uncertainties related to the accuracy of the relative proton stopping power estimates and thereby the water-equivalent path length (WEPL) along the beam. To remedy the range uncertainty, an in vivo measurement of the WEPL through the patient, i.e. a proton-range radiograph, is highly desirable. Towards that goal, we have explored a novel method of proton radiography based on the time-resolved dose measured by a flat panel imager (FPI)...
January 18, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28099021/location-of-methanol-on-the-s2-state-mn-cluster-in-photosystem-ii-studied-by-proton-matrix-electron-nuclear-double-resonance
#15
Hiroki Nagashima, Hiroyuki Mino
Proton matrix electron nuclear double resonance (ENDOR) spectroscopy was performed in order to specify the location of the methanol molecule near the manganese cluster in photosystem II. Comparison of the ENDOR spectra in the presence of CH3OH and CD3OH revealed two pairs of hyperfine couplings, 1.15 MHz for A⊥ and 2.32 MHz for A∥, arising from the methyl group in methanol. Based on the crystal structure, the possible location of methanol close to the manganese cluster was discussed.
January 18, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28098833/role-of-electron-driven-proton-transfer-processes-in-the-ultrafast-deactivation-of-photoexcited-anionic-8-oxoguanine-adenine-and-8-oxoguanine-cytosine-base-pairs
#16
Xiuxiu Wu, Tolga N V Karsili, Wolfgang Domcke
It has been reported that 8-oxo-7,8-dihydro-guanosine (8-oxo-G), which is the main product of oxidative damage of DNA, can repair cyclobutane pyrimidine dimer (CPD) lesions when incorporated into DNA or RNA strands in proximity to such lesions. It has therefore been suggested that the 8-oxo-G nucleoside may have been a primordial precursor of present-day flavins in DNA or RNA repair. Because the electron transfer leading to the splitting of a thymine-thymine pair in a CPD lesion occurs in the photoexcited state, a reasonably long excited-state lifetime of 8-oxo-G is required...
January 14, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28098776/distinguishing-benign-from-malignant-pancreatic-and-periampullary-lesions-using-combined-use-of-%C3%A2-h-nmr-spectroscopy-and-gas-chromatography-mass-spectrometry
#17
Yarrow J McConnell, Farshad Farshidfar, Aalim M Weljie, Karen A Kopciuk, Elijah Dixon, Chad G Ball, Francis R Sutherland, Hans J Vogel, Oliver F Bathe
Previous work demonstrated that serum metabolomics can distinguish pancreatic cancer from benign disease. However, in the clinic, non-pancreatic periampullary cancers are difficult to distinguish from pancreatic cancer. Therefore, to test the clinical utility of this technology, we determined whether any pancreatic and periampullary adenocarcinoma could be distinguished from benign masses and biliary strictures. Sera from 157 patients with malignant and benign pancreatic and periampullary lesions were analyzed using proton nuclear magnetic resonance (¹H-NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS)...
January 13, 2017: Metabolites
https://www.readbyqxmd.com/read/28098444/a-heterogeneous-electrocatalyst-with-molecular-cobalt-ions-serving-as-the-center-of-active-sites
#18
Jiong Wang, Xiaoming Ge, Zhaolin Liu, Larissa Thia, Ya Yan, Wei Xiao, Xin Wang
Molecular Co2+ ions were grafted onto doped graphene in a coordination environment, resulting in the formation of molecularly well-defined, highly active electrocatalytic sites at a heterogeneous interface for the oxygen evolution reaction (OER). The S dopants of graphene are suggested to be one of the binding sites and to be responsible for improving the intrinsic activity of the Co sites. The turnover frequency of such Co sites is greater than that of many Co-based nanostructures and IrO2 catalysts. Through a series of carefully designed experiments, the pathway for the evolution of the Co cation-based molecular catalyst for the OER was further demonstrated on such a single Co-ion site for the first time...
January 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28098408/vonoprazan-improves-the-efficacy-of-helicobacter-pylori-eradication-therapy-with-a-regimen-consisting-of-clarithromycin-and-metronidazole-in-patients-allergic-to-penicillin
#19
Shoko Ono, Mototsugu Kato, Soichi Nakagawa, Katsuhiro Mabe, Naoya Sakamoto
BACKGROUND: Although all Helicobacter pylori (H. pylori)-positive patients should receive eradication therapy, the therapy is a challenge for patients allergic to penicillin. There have been a few reports on the efficacy of eradication therapy for such patients. OBJECTIVE: To analyze the efficacy of vonoprazan or proton pump inhibitor (PPI)-based 7-day triple therapy in patients allergic to penicillin. MATERIALS AND METHODS: A total of 88 consecutive patients allergic to penicillin who received H...
January 18, 2017: Helicobacter
https://www.readbyqxmd.com/read/28098283/high-precision-localized-proton-gradients-and-fluxes-generated-by-a-microelectrode-device-induce-differential-growth-behaviors-of-pollen-tubes
#20
Chengzhi Hu, Hannes Vogler, Marianne Aellen, Naveen Shamsudhin, Bumjin Jang, Jan T Burri, Nino Läubli, Ueli Grossniklaus, Salvador Pané, Bradley J Nelson
Pollen tubes are tip-growing plant cells that deliver the sperm cells to the ovules for double fertilization of the egg cell and the endosperm. Various directional cues can trigger the reorientation of pollen tube growth direction on their passage through the female tissues. Among the external stimuli, protons serve an important, regulatory role in the control of pollen tube growth. The generation of local guidance cues has been challenging when investigating the mechanisms of perception and processing of such directional triggers in pollen tubes...
January 18, 2017: Lab on a Chip
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