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X reactivation

Rui Liu, Huimin Chen, Liping Fang, Cuihong Xu, Zuoliang He, Yujian Lai, Huachao Zhao, Deribachew Bekana Hirpa, Jing-Fu Liu
AuPd bimetallic nanocatalysts exhibit superior catalytic performance in the cleavage of carbon-halogen bonds (C-X) in the hazardous halogenated pollutants. A better understanding of how Au atoms promote the reactivity of Pd sites rather than vaguely interpreting as bimetallic effect, and determining which type of Pd sites are necessary for these reactions are crucial factors for the design of atomically precise nanocatalysts that make full use of both the Pd and Au atoms. Herein, we systematically manipulated the coordination number of Pd-Pd, d-orbital occupation state and Au-Pd interface of the Pd reactive centers, and studied the structure-activity relationship of Au-Pd in the catalyzed cleavage of C-X bonds...
March 16, 2018: Environmental Science & Technology
Marlena Whinton, Timothy C Hughes, Shuhua Peng, Michael A Brook
Bicontinuous microemulsions exhibit domain structures on the nanoscale (<20 nm). Normally, such fine details are lost during the conversion from a fluid microemulsion to solid elastomeric materials, as a consequence of interfacial destabilization via polymerization of either the oil phase, or of monomers in the aqueous phase. Very little is known about the polymerization of silicone microemulsions and the morphological changes that occur upon transition from a nanostructured liquid to a solid ma-trix. Silicone microemulsions polymerized by free radical (aqueous phase) and condensation (silicone phase) processes, respective-ly, were characterized by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM)...
March 16, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Jan Paulo T Zaragoza, Maxime A Siegler, David P Goldberg
High-valent metal-hydroxide species are invoked as critical intermediates in both catalytic, metal-mediated O2 activation (e.g., by Fe porphyrin in Cytochrome P450) and O2 production (e.g., by the Mn cluster in Photosystem II). However, well-characterized mononuclear MIV (OH) complexes remain a rarity. Herein we describe the synthesis of MnIV (OH)(ttppc) (3) (ttppc = tris(2,4,6-triphenylphenyl) corrole), which has been characterized by X-ray diffraction (XRD). The large steric encumbrance of the ttppc ligand allowed for isolation of 3...
March 15, 2018: Journal of the American Chemical Society
Udo Bauer, Florian Späth, Fabian Düll, Philipp Bachmann, Johann Steinhauer, Hans-Peter Steinrück, Christian Papp
We have investigated the adsorption and thermal reactivity of CO and C2H4 on well-defined bimetallic PtxAg1-x/Pt(111) surface alloys (with x = 0.67, 0.50, 0.38 and 0.32) using in situ synchrotron-based high resolution X-ray photoelectron spectroscopy. During low temperature (140 K) adsorption of CO, we find population of the energetically more stable Pt on-top site followed by the Pt bridge site, as known from clean Pt(111); CO does not adsorb on Ag facets under the applied conditions. The total CO coverage linearly decreases with Ag surface content...
March 14, 2018: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Alain Manceau, Jianxu Wang, Mauro Rovezzi, Pieter Glatzel, Xinbin Feng
Plant leaves serve both as a sink for gaseous elemental mercury (Hg) from the atmosphere and a source of toxic mercury to terrestrial ecosystems. Litterfall is the primary deposition pathway of atmospheric Hg to vegetated soils, yet the chemical form of this major Hg input remains elusive. We report the first observation of in vivo formation of mercury sulfur nanoparticles in intact leaves of 22 native plants from six different species across two sampling areas from China. The plants grew naturally in soils from a mercury sulfide mining and retorting region at ambient-air gaseous-Hg concentrations ranging from 131 ± 19 to 636 ± 186 ng m-3 and had foliar Hg concentration between 1...
March 14, 2018: Environmental Science & Technology
Van Luan Pham, Do-Gun Kim, Seok-Oh Ko
A core-shell nanostructure composed of zero-valent Cu (core) and Fe3 O4 (shell) (Cu@Fe3 O4 ) was prepared by a simple reduction method and was evaluated for the degradation of oxytetracycline (OTC), an antibiotic. The Cu core and the Fe3 O4 shell were verified by X-ray diffractometry (XRD) and transmission electron microscopy. The optimal molar ratio of [Cu]/[Fe] (1/1) in Cu@Fe3 O4 created an outstanding synergic effect, leading to >99% OTC degradation as well as H2 O2 decomposition within 10min at the reaction conditions of 1g/L Cu@Fe3 O4 , 20mg/L OTC, 20mM H2 O2 , and pH3...
March 10, 2018: Science of the Total Environment
Valeri Petkov, Yazan Maswadeh, Aolin Lu, Shiyao Shan, Haval Kareem, Yinguang Zhao, Jin Luo, Chuan-Jian Zhong, Kevin Beyer, Karena W Chapman
We present results from combined in situ infrared spectroscopy and total x-ray scattering studies on the evolution of catalytically active sites in exemplary binary and ternary Pt-based nanoalloys during a sequence of CO oxidation-reactivation-CO oxidation reactions. We find that, when within a particular compositional range, the fresh nanoalloys may exhibit high catalytic activity for low-temperature CO oxidation. Using surface-specific atomic pair distribution functions (PDFs) extracted from the in situ total x-ray scattering data we find that, regardless their chemical composition and initial catalytic activity, the fresh nanoalloys suffer a significant surface structural disorder during CO oxidation...
March 13, 2018: ACS Applied Materials & Interfaces
Nan You, Jing Li, Xiaobing Huang, Ke Wu, Yichen Tang, Liang Wang, Hongyan Li, Na Mi, Lu Zheng
While >80% of the incidence occurs in sub‑Saharan Africa and East Asia, cases of hepatocellular carcinoma (HCC) have been rapidly increasing in Western countries. Despite its global importance, HCC is relatively under‑researched compared with other lethal cancer types, which is possibly due to the high complexity and heterogeneity of HCC. It has been reported previously that COMM domain‑containing protein 7 (COMMD7) is upregulated in HCC and promotes HCC cell proliferation by triggering C‑X‑C motif chemokine 10 (CXCL10) production...
March 8, 2018: Molecular Medicine Reports
Atena B Solea, Tobie Wohlhauser, Parisa Abbasi, Yvan Mongbanziama, Aurelien Crochet, Katharina M Fromm, Ghenadie Novitchi, Cyrille Train, Melanie Pilkington, Olimpia Mamula
A versatile synthetic methodology to access the first family of chiral verdazyl N,N'-chelate ligands is described and exemplified by N,N'-dimethyl-, N,N'-di-isopropyl- and N,N'-diphenyl oxoverdazyls bearing two isomers of the pinene-pyridine functional group. Their physical properties were probed by X-band EPR spectroscopy, cyclic voltammetry and DFT calculations. Preliminary reactivity studies show they can act as N,N'-chelate ligands affording a chiral 1 : 1 complex (3b) with CuCl2 , which was characterized by single-crystal X-ray diffraction...
March 13, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Renata Kaczmarek, Dariusz Korczyński, Karolina Królewska-Golińska, Kraig A Wheeler, Ferman A Chavez, Agnieszka Mikus, Roman Dembinski
Reactions of dicobalt octacarbonyl [Co2 (CO)8 ] with 2'-deoxy-5-oxopropynyluridines and related compounds gave dicobalt hexacarbonyl nucleoside complexes (83-31 %). The synthetic outcomes were confirmed by X-ray structure determination of dicobalt hexacarbonyl 2'-deoxy-5-(4-hydroxybut-1-yn-1-yl)uridine, which exhibits intermolecular hydrogen bonding between a modified base and ribose. The electronic structure of this compound was characterized by the DFT calculations. The growth inhibition of HeLa and K562 cancer cell lines by organometallic nucleosides was examined and compared to that by alkynyl nucleoside precursors...
March 2018: ChemistryOpen
Ismet H Bajraktari, Blerim Krasniqi, Sylejman Rexhepi, Sadi Bexheti, Elton Bahtiri, Halit Bajraktari, Besim Luri
BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterised by intra-articular and extra-articular manifestations but very rarely with coxitis. AIM: This study aimed to investigate the prevalence of coxitis, clinical changes, and its correlation with the parameters of inflammatory activity. METHODS: A cohort of 951 patients diagnosed with ACR/EULAR (American College of Rheumatology/European League against Rheumatism) 2010 criteria was enrolled in this prospective, observational and analytic research study...
February 15, 2018: Open Access Macedonian Journal of Medical Sciences
Bin Wu, Jingshan Huang, Keisuke Fukuo, Kazuhisa Suzuki, Gen Yoshino, Tsutomu Kazumi
The aim of this study was to assess whether the gender-specific pattern of fat mass (FM) distribution is related to gender differences in cardiometabolic risk factors. 207 healthy middle-aged Japanese were included in the study. We measured FM in the total body, trunk, and lower-body with dual-energy X-ray absorptiometry (DXA). The percentage of trunk FM (TFM) and lower-body FM (LFM) is noted as %TFM and %LFM, respectively. Other measurements included glucose and insulin during oral glucose tolerance test (OGTT), leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor- α (TNF- α ), C-reactive protein (CRP), and systemic oxidative stress marker...
2018: International Journal of Endocrinology
Ben J Glasgow, Tara A McCannel
PURPOSE: Prior studies have shown nuclear reactivity for BAP1 yields prognostic information for paraffin embedded uveal melanomas. Lacking are immunocytochemical studies of BAP1 on fine needle aspiration biopsies of uveal melanoma that correlate with prognosis or other markers of prognosis. Our purpose was to fill this gap. DESIGN: Experimental laboratory study METHODS: Fine needle aspiration biopsies were performed prospectively on 113 patients with uveal melanomas garnering limited subsets of cases for comparison...
March 9, 2018: American Journal of Ophthalmology
Michael Lucas, Aaron M Thomas, Ralf I Kaiser, Eugene K Bashkirov, Valeriy N Azyazov, Alexander Moiseevich Mebel
We explored the elementary reaction of atomic carbon (C;3 Pj ) with pyridine (C5 H5 N; X1 A1 ) at a collision energy of 34 ± 4 kJ mol-1 utilizing the crossed molecular beams technique. Forward-convolution fitting of the data was combined with high-level electronic structure calculations and statistical (RRKM) calculations on the triplet C6 H5 N potential energy surface (PES). These investigations reveal that the reaction dynamics are indirect and dominated by large range reactive impact parameters leading via barrier-less addition to the nitrogen atom and to two chemically non-equivalent 'aromatic' carbon-carbon bonds forming three distinct collision complexes...
March 12, 2018: Journal of Physical Chemistry. A
Song-Lin Zhang, Chang Xiao, Hai-Xing Wan
Cu(iii) trifluoromethyl complexes are proposed as essential intermediates for many copper-promoted trifluoromethylation reactions, but remain elusive and scarcely explored. We report herein the isolation and spectroscopic and X-ray crystallographic characterization of diverse CuIII -CF3 complexes (6-10) with varied coordinating motifs (mono-, bi- or tridentate) and formal charges (neutral or monoanionic) for the ligand L (L is pyridine, 2,4,6-trimethylpyridine, quinol-8-yloxide or 2,6-bis(2'-pyridyl)pyridine)...
March 12, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Javier Iglesias-Sigüenza, Cristina Izquierdo, Elena Díez, Rosario Fernández, José M Lassaletta
The direct dialkylation of triazolo[4,3-b]isoquinolin-3-ylidene structures readily affords dicationic N-heterotricyclic azolium salts. These are suitable starting materials for the synthesis of transition metal complexes containing N-heterotricyclic, cationic ligands characterized by extended charge delocalization. Silver and gold complexes as well as mono- and dicationic rhodium(i) complexes have been prepared and characterized, and the electronic properties of the ligand have been evaluated by using the TEP parameter and by comparison with a non-cationic analogue...
March 12, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Takayuki Iida, Koji Ohara, Yuriy Román-Leshkov, Toru Wakihara
Zeolites containing framework heteroatoms (e.g., Ti, Sn, and Hf) with open coordination sites behave as solid-state Lewis acids and exhibit remarkable catalytic properties unachievable with bulk oxides. However, direct evidence confirming the incorporation of such heteroatom species into the zeolite framework is difficult to obtain because of the limited number of analytical methods capable of discerning framework incorporation from extraframework species. In this work, the structural environments of hafnium (Hf) framework and extraframework species added post-synthetically into *BEA zeolites were analyzed using coupled pair distribution function (PDF) and diffuse reflectance (DR) UV-vis measurements...
March 12, 2018: Physical Chemistry Chemical Physics: PCCP
Yang Zhou, Dongshuai Hou, Guoqing Geng, Pan Feng, Jiao Yu, Jinyang Jiang
The mechanical properties of organic/inorganic composites can be highly dependent on the interfacial interactions. In this work, with organic polymers intercalated into the interlayer of inorganic calcium silicate hydrate (C-S-H), the primary binding phase of Portland cement, great ductility improvement is obtained for the nanocomposites. Employing reactive molecular dynamics, the simulation results indicate that strong interfacial interactions between the polymers and the substrate contribute greatly to strengthening the materials, when C-S-H/poly ethylene glycol (PEG), C-S-H/poly acrylic acid (PAA), and C-S-H/poly vinyl alcohol (PVA) were subject to uniaxial tension along different lattice directions...
March 12, 2018: Physical Chemistry Chemical Physics: PCCP
Stefan Iglauer, Maxim Lebedev
Physical, chemical and mechanical pore-scale (i.e. micrometer-scale) mechanisms in rock are of key importance in many, if not all, subsurface processes. These processes are highly relevant in various applications, e.g. hydrocarbon recovery, CO2 geo-sequestration, geophysical exploration, water production, geothermal energy production, or the prediction of the location of valuable hydrothermal deposits. Typical examples are multi-phase flow (e.g. oil and water) displacements driven by buoyancy, viscous or capillary forces, mineral-fluid interactions (e...
December 28, 2017: Advances in Colloid and Interface Science
Dengjie Zhong, Xinrong Liao, Yaqi Liu, Nianbing Zhong, Yunlan Xu
A new electrode which embedded polyaniline (PANI) in petaline NiO (NiO@PANI-CF) was prepared through in-situ growth and in-situ polymerization. The NiO@PANI-CF integrated the high capacitive character of NiO and the high conductivity of PANI, which effectively increased electricity generation capacity of NiO@PANI-MFC. The maximum output power density and the charge transfer resistance of NiO@PANI-MFC were 1078.8 mW·m-2 and 10.4 Ω respectively, which were 6.6 times and 68% lower than that of CF-MFC respectively...
February 1, 2018: Bioresource Technology
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