keyword
MENU ▼
Read by QxMD icon Read
search

Metallic hydrogen

keyword
https://www.readbyqxmd.com/read/28551529/spectroscopic-investigation-of-the-reaction-of-metallo-protoporphyrins-with-hydrogen-sulfide
#1
Matthew D Hartle, McKinna R Tillotson, James S Prell, Michael D Pluth
Hydrogen sulfide (H2S) is the most recently discovered gasotransmitter molecule joining nitric oxide and carbon monoxide. In addition to being biologically important gases, these gasotransmitters also provide distinct modes of reactivity with biomimetic metal complexes. The majority of previous investigations on the reactivity of H2S with bioinorganic models have focused on Fe-based porphyrin systems, whereas investigations with other metals remains underinvestigated. To address this gap, we report here an examination of the reactions of H2S, HS(-), and S8 with Mg(II), Cu(II), Co(II), Zn(II), Cr(II), Sn(IV), and Mn(II/III) protoporphyrins...
April 25, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28549217/surface-enhanced-raman-scattering-active-gold-nanoparticles-with-enzyme-mimicking-activities-for-measuring-glucose-and-lactate-in-living-tissues
#2
Yihui Hu, Hanjun Cheng, Xiaozhi Zhao, Jiangjiexing Wu, Faheem Muhammad, Shichao Lin, Jian He, Liqi Zhou, Chengping Zhang, Yu Deng, Peng Wang, Zhengyang Zhou, Shuming Nie, Hui Wei
Gold nanoparticles (AuNPs) with simultaneous plasmonic and biocatalytic properties provide a promising approach to developing versatile bioassays. However, the combination of AuNPs' intrinsic enzyme mimicking properties with their surface-enhanced Ra-man scattering (SERS) activities has yet to be explored. Here we designed a peroxidase mimicking nanozyme by in situ growing AuNPs into a highly porous and thermally stable metal-organic framework (MOF) called MIL-101. The obtained AuNPs@MIL-101 nanozymes acted as the peroxidase mimics to oxidize Raman inactive reporter leucomalachite green (LMG) into the active malachite green (MG) with hydrogen peroxide, and simultaneously as the SERS substrates to enhance the Raman signals of the as-produced MG...
May 26, 2017: ACS Nano
https://www.readbyqxmd.com/read/28546425/the-first-crystal-structure-of-a-family-129-glycoside-hydrolase-from-a-probiotic-bacterium-reveals-critical-residues-and-metal-co-factors
#3
Mayo Sato, Dorothee Liebschner, Yusuke Yamada, Naohiro Matsugaki, Takatoshi Arakawa, Siobhan S Wills, Mitchell Hattie, Keith A Stubbs, Tasuku Ito, Toshiya Senda, Hisashi Ashida, Shinya Fushinobu
The α-N-acetylgalactosaminidase from the probiotic bacterium Bifidobacterium bifidum (NagBb) belongs to the glycoside hydrolase (GH) family 129 and hydrolyzes the glycosidic bond of Tn antigen (GalNAcα1-Ser/Thr). NagBb is involved in assimilation of O-glycans on mucin glycoproteins by B. bifidum in the human gastrointestinal tract, but its catalytic mechanism has remained elusive because of a lack of sequence homology around putative catalytic residues and of other structural information. Here we report the X-ray crystal structure of NagBb, representing the first GH129 family structure, solved by the single-wavelength anomalous dispersion method based on sulfur atoms of the native protein...
May 25, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28546116/heteroleptic-metal-ii-complexes-of-hydrotris-methimazolyl-borate-and-diimines-synthesis-theoretical-calculations-antimicrobial-antioxidant-in-vitro-cytotoxicity-and-molecular-docking-studies
#4
S Jayakumar, D Mahendiran, Dilaveez Rehana, A Kalilur Rahiman
A series of heteroleptic metal(II) complexes of formulation [M(Tm)(diimine)](ClO4) (1-8), [Tm = hydrotris(methimazolyl)borate, diimine = 2,2'-bipyridyl or 1,10-phenanthroline and M = Mn(II), Ni(II), Cu(II) or Zn(II)] have been synthesized and characterized by spectroscopic methods. The geometric parameters of the complexes were determined using UV-Vis spectroscopy and DFT calculations. The analyses of HOMO and LUMO have been used to explain the charge transfer within the molecule. Antimicrobial activity of the synthesized heteroleptic complexes were evaluated against two Gram (-ve) (Escherichia coli and Klebsiella pneumoniae) and two Gram (+ve) (Bacillus cereus and Staphylococcus aureus) bacterial, and three fungal (Candida albicans, Candida glabrata and Candida krusei) strains with respect to the standard drugs erythromycin and amphotericin-B...
May 22, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28545261/microbicidal-activity-of-n-chlorotaurine-in-combination-with-hydrogen-peroxide
#5
Jasmin Mustedanagic, Valdecir Farias Ximenes, Markus Nagl
N-chlorotaurine (NCT) and hydrogen peroxide are powerful endogenous antiseptics. In vivo, the reaction between hydrogen peroxide and metal ions leads to the formation of free hydroxyl radicals, which have an increased bactericidal activity. This study examined whether there is an additive antimicrobial effect of NCT combined with hydrogen peroxide. Additionally, it was tested if the additive effect is based on the formation of free radicals. We found by luminometry that, in the presence of H2O2, NCT caused a slow and long-lasting production of singlet oxygen in contrast to HOCl, where this burst occurred instantaneously...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28544652/brownmillerite-type-ca2fecoo5-as-a-practicable-oxygen-evolution-reaction-catalyst
#6
Etsushi Tsuji, Teruki Motohashi, Hiroyuki Noda, Damian Kowalski, Yoshitaka Aoki, Hajime Tanida, Junji Niikura, Yukinori Koyama, Masahiro Mori, Hajime Arai, Tsutomu Ioroi, Naoko Fujiwara, Yoshiharu Uchimoto, Zempachi Ogumi, Hiroki Habazaki
Here, we report remarkable oxygen evolution reaction (OER) catalytic activity of brownmillerite (BM)-type Ca2FeCoO5. The OER activity of this oxide is comparable to or beyond those of the state-of-the-art perovskite (PV)-catalyst Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) and a precious-metal catalyst RuO2, emphasizing the importance of the characteristic BM structure with multiple coordination environments of transition metal (TM) species. Also, Ca2FeCoO5 is obviously advantageous in terms of expense/laboriousness of the material synthesis...
May 25, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28544383/self-assembled-biomimetic-chloroplast-coupled-photoenzymatic-reaction-for-sustainable-synthesis-of-fuel
#7
Xuehai Yan, Kai Liu, Chengqian Yuan, Qianli Zou, Zengchun Xie
Prototypes of biosystems provide good blueprints for the design and creation of biomimetic systems. However, mimicking both the sophisticated natural structures and their complex biological functions still remains a great challenge. Herein, biomimetic chloroplasts have been fabricated by one-step bio-inspired amino acid mineralization and simultaneous integration of catalytically active units. Hierarchically structured crystals are obtained by metal ion-directed self-assembly of cystine (the oxidized dimer form of the amino acid cysteine), with porous structure and stacking nanorods, which show similar architectural principles to chloroplasts...
May 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544178/transition-metal-nitride-core-noble-metal-shell-nanoparticles-as-highly-co-tolerant-catalysts
#8
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/28544164/rapid-production-of-high-purity-hydrogen-fuel-through-microwave-promoted-deep-catalytic-dehydrogenation-of-liquid-alkanes-with-abundant-metals
#9
Xiangyu Jie, Sergio Gonzalez-Cortes, Tiancun Xiao, Jiale Wang, Benzhen Yao, Daniel R Slocombe, Hamid A Al-Megren, Jonathan R Dilworth, John M Thomas, Peter P Edwards
Hydrogen as an energy carrier promises a sustainable energy revolution. However, one of the greatest challenges for any future hydrogen economy is the necessity for large scale hydrogen production not involving concurrent CO2 production. The high intrinsic hydrogen content of liquid-range alkane hydrocarbons (including diesel) offers a potential route to CO2 -free hydrogen production through their catalytic deep dehydrogenation. We report here a means of rapidly liberating high-purity hydrogen by microwave-promoted catalytic dehydrogenation of liquid alkanes using Fe and Ni particles supported on silicon carbide...
May 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28543826/helically-chiral-peptides-containing-ferrocene-1-1-diamine-scaffold-as-a-turn-inducer
#10
Lidija Barisic, Monika Kovacevic, Ivan Kodrin, Suncica Roca, Kresimir Molcanov, Yuning Shen, Bimalendu Adhikari, Heinz-Bernhard Kraatz
A series of peptides containing homo- and heterochiral Ala-Pro sequences attached to the turn inducing ferrocene-1,1'-diamine scaffold was synthesized. The effects of the backbone chirality and N-terminal group (Boc/Ac) on the conformational properties of the novel peptidomimetics were thoroughly explored by IR, NMR and CD spectroscopies as well as corroborated by DFT studies in solution. The most stable conformers of the homochiral peptides adopt the interstrand hydrogen bonding patterns, realized through ten- and thirteen-membered rings...
May 24, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28543748/universal-method-for-large-scale-synthesis-of-layered-transition-metal-dichalcogenides
#11
Zdenek Sofer, David Sedmidubsky, Jan Luxa, Daniel Bousa, Stepan Huber, Petr Lazar, Martin Vesely, Martin Pumera
The layered transition metal dichalcogenides currently belong to the most intensively investigated materials. These com-pounds constitute a broad family of materials with characteristic layered structures and covering both semiconductors and metallic materials. The great attention arises from the possibility to exfoliate these materials down to single layers with many unique properties like thickness dependent energy of band gap and the possibility of tuning transport properties by phase transitions. The research in the field of transition metal dichalcogenides is also motivated by their high electrocatalytic activity towards several industrially important reactions like hydrogen evolution reaction as well as many other applications in nano- and optoelectronics...
May 20, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28541715/biodegradation-and-kinetics-of-organic-compounds-and-heavy-metals-in-an-artificial-wetland-system-aws-by-using-water-hyacinths-as-a-biological-filter
#12
P F Rodríguez-Espinosa, J A Mendoza-Pérez, J Tabla-Hernandez, E Martínez-Tavera, M M Monroy-Mendieta
The objective of the present study was to investigate the ability of water hyacinth (Eichhornia crassipes) to absorb organic compounds (potassium hydrogen phthalate, sodium tartrate, malathion, 2,4-D and piroxicam). For the aforementioned purpose, an artificial wetland system (AWS) was constructed and filled with water hyacinth collected from Valsequillo Reservoir, Puebla, Mexico. Potassium hydrogen phthalate and sodium tartrate were measured in terms of Chemical Oxygen Demand (COD) and the Biological Oxygen Demand (BOD)...
May 25, 2017: International Journal of Phytoremediation
https://www.readbyqxmd.com/read/28540960/photochemical-reactions-of-metal-complexes-in-the-solid-state
#13
Jagadese J Vittal, Hong Sheng Quah
This perspective focusses on the solid-state reactivity and structural transformation driven by photochemical methods in discrete metal complexes, organometallic compounds, metallo-macrocycles and cages. Changes in the metal-metal bond distances, racemization of chiral centres, fusion of cages, formation of coordination polymers, expected [2 + 2] and [4 + 4] cycloaddition products, unusual phenyl-olefin dimerization, and linkage isomerization of -SO2, -NO & -NO2 ligands cause the structural transformations...
May 25, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28539605/coupling-mechanism-between-wear-and-oxidation-processes-of-304-stainless-steel-in-hydrogen-peroxide-environments
#14
Conglin Dong, Chengqing Yuan, Xiuqin Bai, Jian Li, Honglin Qin, Xinping Yan
Stainless steel is widely used in strongly oxidizing hydrogen peroxide (H2O2) environments. It is crucial to study its wear behaviour and failure mode. The tribological properties and oxidation of 304 stainless steel were investigated using a MMW-1 tribo-tester with a three-electrode setup in H2O2 solutions with different concentrations. Corrosion current densities (CCDs), coefficients of frictions (COFs), wear mass losses, wear surface topographies, and metal oxide films were analysed and compared. The results show that the wear process and oxidation process interacted significantly with each other...
May 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28539265/removal-of-toxic-heavy-metal-lead-ii-using-chitosan-oligosaccharide-graft-maleic-anhydride-polyvinyl-alcohol-silk-fibroin-composite
#15
Ajitha P, Vijayalakshmi K, Saranya M, Gomathi T, Rani K, Sudha P N, Anil Sukumaran
The present work was aimed to investigate the efficiency of novel chitosan oligosaccharide-graft-maleic anhydride(COS-g-MAH)/Polyvinyl alcohol (PVA)/silk fibroin (SF) composite for removing the toxic heavy metal lead (II) ion from aqueous solution by batch adsorption studies. Initially the chitosan oligosaccharide-graft-maleic anhydride copolymer has been prepared by utilizing ceric ammonium nitrate as an initiator and the optimised graft copolymer was then used for synthesizing COS-g-MAH/PVA/SF composite. The prepared samples were analyzed through FTIR and XRD studies...
May 21, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28537615/constructing-three-dimensional-porous-ni-ni3s2-nano-interfaces-for-hydrogen-evolution-electrocatalysis-under-alkaline-conditions
#16
Yiming An, Bolong Huang, Zilong Wang, Xia Long, Yongcai Qiu, Jue Hu, Dan Zhou, He Lin, Shihe Yang
It is still a challenging issue to design earth-abundant electrocatalysts with low cost, high activity and long-term stability for the hydrogen evolution reaction (HER) based on water splitting in alkaline solutions. Here, we report a facile synthetic route for a three-dimensional, porous Ni/Ni3S2 nano-network on carbon cloth for the efficient catalysis of HER. This unique structure exposes a high proportion of Ni/Ni3S2 hetero-interfaces to the electrolyte, creating a synergetic effect between Ni and Ni3S2 that enhances HER...
May 24, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28537588/activation-and-discovery-of-earth-abundant-metal-catalysts-using-sodium-tert-butoxide
#17
Jamie H Docherty, Jingying Peng, Andrew P Dominey, Stephen P Thomas
First-row, earth-abundant metals offer an inexpensive and sustainable alternative to precious-metal catalysts. As such, iron and cobalt catalysts have garnered interest as replacements for alkene and alkyne hydrofunctionalization reactions. However, these have required the use of air- and moisture-sensitive catalysts and reagents, limiting both adoption by the non-expert as well as applicability, particularly in industrial settings. Here, we report a simple method for the use of earth-abundant metal catalysts by general activation with sodium tert-butoxide...
June 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28537379/molecular-rhodium-complexes-supported-on-the-metal-oxide-like-nodes-of-metal-organic-frameworks-and-on-zeolite-hy-catalysts-for-ethylene-hydrogenation-and-dimerization
#18
Varinia Bernales, Dong Yang, Jun Yu, Gamze Gümüşlü, Christopher J Cramer, Bruce C Gates, Laura Gagliardi
Metal-organic frameworks (MOFs) with nodes consisting of zirconium oxide clusters (Zr6) offer new opportunities as supports for catalysts with well-defined, essentially molecular, structures. We used the precursor Rh(C2H4)2(acac) (acac is acetylacetonate) to anchor Rh(I) complexes to the nodes of the MOF UiO-67 and, for comparison, to the zeolite dealuminated HY (DAY). These were characterized experimentally by measurement of catalytic activities and selectivities for ethylene hydrogenation and dimerization in a once-through flow reactor at 298 K and 1 bar...
May 24, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28535047/electronic-and-morphological-dual-modulation-of-cobalt-carbonate-hydroxides-by-mn-doping-towards-highly-efficient-and-stable-bifunctional-electrocatalysts-for-overall-water-splitting
#19
Tang Tang, Wen-Jie Jiang, Shuai Niu, Ning Liu, Hao Luo, Yu-Yun Chen, Shi-Feng Jin, Feng Gao, Li-Jun Wan, Jin-Song Hu
Developing bifunctional non-noble electrocatalysts for efficient and durable oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable and challenging for overall water splitting. Herein, Co-Mn carbonate hydroxide (CoMnCH) nanosheet arrays with controllable morphology and composition were developed on nickel foam (NF) as such bifunctional electrocatalysts. It was discovered that Mn doping in CoCH can simultaneously modulate the nanosheet morphology to significantly increase the electrochemical active surface area for exposing more accessible active sites and tune the electronic structure of Co center to effectively boost its intrinsic activity...
May 23, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28531970/ultrasensitive-cholesterol-biosensor-based-on-enzymatic-silver-deposition-on-gold-nanoparticles-modified-screen-printed-carbon-electrode
#20
Yong Huang, Lijie Cui, Yewei Xue, Songbai Zhang, Nixuan Zhu, Jintao Liang, Guiyin Li
Cholesterol is one of the essential structural constituents of cell membranes. Determination of cholesterol is of great importance in clinical analysis because the level of cholesterol in serum is an indicator in the diagnosis and prevention of heart diseases. In this work, a simple and ultrasensitive cholesterol biosensor based on enzymatic silver deposition was designed by immobilizing cholesterol oxidase (CHOD) and cholesterol esterase (CHER) onto the surface of gold nanoparticles (Au NPs) modified screen-printed carbon electrode (SPE)...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
keyword
keyword
64973
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"