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https://www.readbyqxmd.com/read/28437119/synthesis-of-naphthoquinolizinones-through-rh-iii-catalyzed-double-c-sp-2-h-bond-carbenoid-insertion-and-annulation-of-2-aryl-3-cyanopyridines-with-%C3%AE-diazo-carbonyl-compounds
#1
Beibei Zhang, Bin Li, Xinying Zhang, Xuesen Fan
An unprecedented Rh(III)-catalyzed double C(sp(2))-H bond carbenoid insertion and annulation of 2-aryl-3-cyanopyridines with α-diazo carbonyl compounds is presented. Through this cascade reaction, a series of naphthoquinolizinone derivatives with a large π-system were efficiently prepared. The reactions could selectively afford naphthoquinolizinones with either an amine or an amide unit attached on the 11-position depending on the nature of the solvent and the additive used. Compared with literature methods, this is a more efficient, convenient, and atom-economic way to provide polycyclic heteroaromatic compounds through direct π-extension of simple aromatics via inert C-H bond activation and functionalization...
April 24, 2017: Organic Letters
https://www.readbyqxmd.com/read/28436523/mechanistic-insights-into-the-selective-cyclization-of-indolines-with-alkynes-and-alkenes-to-produce-six-and-seven-membered-1-7-fused-indolines-via-rh-iii-catalysis-a-theoretical-study
#2
Lingli Han, Xinyu Zhang, Xingdong Wang, Fengyue Zhao, Shaojing Liu, Tao Liu
The coupling reaction mechanisms of the Rh(iii)-catalyzed redox-neutral C7-selective aryl C-H functionalization of indolines with alkynes and alkenes have been theoretically investigated with the aid of the density functional theory (DFT) calculations. Our calculation results indicate that the active catalyst in this system is the cationic species [Cp*Rh(OAc)](+) (2cat) instead of the neutral species Cp*Rh(OAc)2 (1cat). The origin of forming different products associated with using different coupling partners was also rationalized in detail...
April 24, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28429455/base-controlled-completely-selective-linear-or-branched-rhodium-i-catalyzed-c-h-ortho-alkylation-of-azines-without-preactivation
#3
Gaël Tran, Kevin D Hesp, Vincent Mascitti, Jonathan A Ellman
A [Rh(I) ]/bisphosphine/base catalytic system for the ortho-selective C-H alkylation of azines by acrylates and acrylamides is reported. This catalytic system features an unprecedented complete linear or branched selectivity that is solely dependent on the catalytic base that is used. Complete branched selectivity is even achieved for ethyl methacrylate, which enables the introduction of a quaternary carbon center. Excellent functional group compatibility is demonstrated for both linear and branched alkylations...
April 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28422264/rhodium-catalyzed-addition-of-sulfonyl-hydrazides-to-allenes-regioselective-synthesis-of-branched-allylic-sulfones
#4
Vahid Khakyzadeh, Yu-Hsuan Wang, Bernhard Breit
A rhodium-catalyzed regioselective addition of sulfonyl hydrazides to allenes is reported. With Rh(i)/DPEphos/benzoic acid as the catalyst system, branched allylic sulfones can be obtained, in good to excellent yields and regioselectivities.
April 19, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28414337/development-of-an-incoherent-broad-band-cavity-enhanced-aerosol-extinction-spectrometer-and-its-application-to-measurement-of-aerosol-optical-hygroscopicity
#5
Weixiong Zhao, Xuezhe Xu, Bo Fang, Qilei Zhang, Xiaodong Qian, Shuo Wang, Pan Liu, Weijun Zhang, Zhenzhu Wang, Dong Liu, Yinbo Huang, Dean S Venables, Weidong Chen
We report on the development of a blue light-emitting-diode-based incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for the measurement of the aerosol extinction coefficient at λ=461  nm. With an effective absorption path length of 2.8 km, an optimum detection limit of 0.05  Mm<sup>-1</sup> (5×10<sup>-10</sup>  cm<sup>-1</sup>) was achieved with an averaging time of 84 s. The baseline drift of the developed spectrometer was about ±0...
April 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/28403850/rationale-and-design-of-a-multicenter-placebo-controlled-double-blind-randomized-trial-to-evaluate-the-effect-of-empagliflozin-on-endothelial-function-the-emblem-trial
#6
RANDOMIZED CONTROLLED TRIAL
Atsushi Tanaka, Michio Shimabukuro, Yosuke Okada, Isao Taguchi, Minako Yamaoka-Tojo, Hirofumi Tomiyama, Hiroki Teragawa, Seigo Sugiyama, Hisako Yoshida, Yasunori Sato, Atsushi Kawaguchi, Yumi Ikehara, Noritaka Machii, Tatsuya Maruhashi, Kosuke R Shima, Toshinari Takamura, Yasushi Matsuzawa, Kazuo Kimura, Masashi Sakuma, Jun-Ichi Oyama, Teruo Inoue, Yukihito Higashi, Shinichiro Ueda, Koichi Node
BACKGROUND: Type 2 diabetes mellitus (T2DM) is characterized by systemic metabolic abnormalities and the development of micro- and macrovascular complications, resulting in a shortened life expectancy. A recent cardiovascular (CV) safety trial, the EMPA-REG OUTCOME trial, showed that empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, markedly reduced CV death and all-cause mortality and hospitalization for heart failure in patients with T2DM and established CV disease (CVD)...
April 12, 2017: Cardiovascular Diabetology
https://www.readbyqxmd.com/read/28399420/dietary-rose-hip-exerts-antiatherosclerotic-effects-and-increases-nitric-oxide-mediated-dilation-in-apoe-null-mice
#7
Michele Cavalera, Ulrika Axling, Catarina Rippe, Karl Swärd, Cecilia Holm
Atherosclerosis is a disease in which atheromatous plaques develop inside arteries, leading to reduced or obstructed blood flow that in turn may cause stroke and heart attack. Rose hip is the fruit of plants of the genus Rosa, belonging to the Rosaceae family, and it is rich in antioxidants with high amounts of ascorbic acid and phenolic compounds. Several studies have shown that fruits, seeds and roots of these plants exert antidiabetic, antiobesity and cholesterol-lowering effects in rodents as well as humans...
March 21, 2017: Journal of Nutritional Biochemistry
https://www.readbyqxmd.com/read/28395388/results-of-a-modular-femoral-revision-system-before-and-after-taper-roller-hardening-in-total-hip-arthroplasty
#8
Dean J Marshall, Keith R Berend, Michael J Morris, Joanne B Adams, Adolph V Lombardi
INTRODUCTION: Modular component options can aid in addressing complex femoral reconstructions in total hip arthroplasty (THA) by allowing for customization of version control and proximal to distal sizing. However, component breakage at the modular junction has occurred, particularly in the presence of poor bone stock. A taper roller hardening (RH) process was developed to strengthen the modular junction to reduce breakage. The purpose of this study is to review THA patients before and after taper roller hardening to compare stem survival and frequency of breakage...
April 11, 2017: Surgical Technology International
https://www.readbyqxmd.com/read/28394617/understanding-the-impact-of-water-on-the-miscibility-and-microstructure-of-amorphous-solid-dispersions-an-afm-lcr-and-tem-edx-study
#9
Na Li, Christopher J Gilpin, Lynne S Taylor
Miscibility is critical for amorphous solid dispersions (ASDs). Phase-separated ASDs are more prone to crystallization, and thus can lose their solubility advantage leading to product failure. Additionally, dissolution performance can be diminished as a result of phase separation in the ASD matrix. Water is known to induce phase separation during storage for some ASDs. However, the impact of water introduced during preparation has not been as thoroughly investigated to date. The purpose of this study was to develop a mechanistic understanding of the effect of water on the phase behavior and microstructure of ASDs...
April 19, 2017: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/28390289/lenvatinib-an-oral-multi-kinases-inhibitor-associated-hypertension-potential-role-of-vascular-endothelial-dysfunction
#10
Daisuke Sueta, Koichi Suyama, Aiko Sueta, Noriaki Tabata, Takayoshi Yamashita, Mai Tomiguchi, Takashi Takeshita, Mutsuko Yamamoto-Ibusuki, Eiichiro Yamamoto, Yasuhiro Izumiya, Koichi Kaikita, Yutaka Yamamoto, Seiji Hokimoto, Hirotaka Iwase, Kenichi Tsujita
BACKGROUND AND AIMS: Lenvatinib (Lenvima(®)), an oral multi-kinase inhibitor, is effective in the treatment of differentiated thyroid carcinomas (DTCs). A severe adverse effect of lenvatinib is hypertension, thus limiting its use as an anti-cancer treatment. Although the pathogenesis of hypertension is generally assumed to involve microvascular bed reduction and an increase in peripheral vascular resistance due to a decrease in nitrogen oxide (NOx) production after vascular endothelial growth factor (VEGF) inhibition, the effects of hypertension on vascular endothelial function in actual patients remain unclear...
May 2017: Atherosclerosis
https://www.readbyqxmd.com/read/28383287/successful-synthesis-and-thermal-stability-of-immiscible-metal-au-rh-au-ir-and-au-ir-rh-nanoalloys
#11
Yury Shubin, Pavel Plusnin, Marat Sharafutdinov, Evgenia Makotchenko, Sergey Korenev
We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6]х[Rh(NO2)6]1-х and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals "mixed" at the molecular level, thus providing significant advantages for obtaining alloys. The observations using HR TEM show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5±3 nm...
April 6, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28380024/gelatin-device-for-the-delivery-of-growth-factors-involved-in-endochondral-ossification
#12
Lucas A J Ahrens, Daniel Vonwil, Jon Christensen, V Prasad Shastri
Controlled release drug delivery systems are well established as oral and implantable dosage forms. However, the controlled release paradigm can also be used to present complex soluble signals responsible for cellular organization during development. Endochondral ossification (EO), the developmental process of bone formation from a cartilage matrix is controlled by several soluble signals with distinct functions that vary in structure, molecular weight and stability. This makes delivering them from a single vehicle rather challenging...
2017: PloS One
https://www.readbyqxmd.com/read/28379248/one-pot-synthesis-of-%C3%AE-aminophosphonates-via-a-cascade-sequence-of-allylamine-isomerization-hydrophosphonylation
#13
Liu-Liang Mao, Chen-Chen Li, Qiang Yang, Ming-Xing Cheng, Shang-Dong Yang
A Rh/Ni-catalyzed cascade sequence of allylamine isomerization and hydrophosphonylation to synthesize α-aminophosphonates has been disclosed. The reaction, which not only allows the generation of widespread valuable α-aminophosphonates under simple systems and mild conditions, but also enriches the process of olefin isomerization-addition both in catalytic systems and various reaction types.
April 5, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28379165/performance-assessment-of-a-humidity-measurement-system-and-its-use-to-evaluate-moisture-characteristics-of-wheelchair-cushions-at-the-user-seat-interface
#14
Zhuofu Liu, Haifeng Cheng, Zhongming Luo, Vincenzo Cascioli, Andrew I Heusch, Nadia R Nair, Peter W McCarthy
Little is known about the changes in moisture that occur at the body-seat interface during sitting. However, as increased moisture can add to the risk of skin damage, we have developed an array of MEMS (Micro-Electro-Mechanical System) humidity sensors to measure at this interface. Sensors were first evaluated against traceable standards, followed by use in a cross-over field test (n = 11; 20 min duration) using different wheelchair cushions (foam and gel). Relative humidity (RH) was measured at the left mid-thigh, right mid-thigh and coccyx...
April 5, 2017: Sensors
https://www.readbyqxmd.com/read/28377560/recent-advances-in-the-pathophysiology-of-arterial-hypertension-potential-implications-for-clinical-practice
#15
Dagmara Hering, Andrzej Trzebski, Krzysztof Narkiewicz
Hypertension remains a major and growing public health problem associated with the greatest global rate of cardiovascular morbidity and mortality. Although numerous factors contribute to poor control of blood pressure (BP) and to pseudoresistance (eg, unawareness, lifestyle habits, nonadherence to medication, insufficient treatment, drug‑induced hypertension, undiagnosed secondary causes), true resistant hypertension (RH) is reported in 10.1% of patients treated for elevated BP. While the mechanisms underlying RH remain complex and not entirely understood, sympathetic activation involved in the pathophysiology of hypertension, disease progression, and adverse complications is further augmented in patients with drug‑resistant hypertension...
March 1, 2017: Polish Archives of Internal Medicine
https://www.readbyqxmd.com/read/28372759/on-road-emissions-of-co-co2-and-nox-from-four-wheeler-and-emission-estimates-for-delhi
#16
Jaiprakash, Gazala Habib, Anil Kumar, Akash Sharma, Minza Haider
This study presents the emission factor of gaseous pollutants (CO, CO2, and NOX) from on-road tailpipe measurement of 14 passenger cars of different types of fuel and vintage. The trolley equipped with stainless steel duct, vane probe velocity meter, flue gas analyzer, Nondispersive infra red (NDIR) CO2 analyzer, temperature, and relative humidity (RH) sensors was connected to the vehicle using a towing system. Lower CO and higher NOX emissions were observed from new diesel cars (post 2010) compared to old cars (post 2005), which implied that new technological advancement in diesel fueled passenger cars to reduce CO emission is a successful venture, however, the use of turbo charger in diesel cars to achieve high temperature combustion might have resulted in increased NOX emissions...
March 2017: Journal of Environmental Sciences (China)
https://www.readbyqxmd.com/read/28368339/fiber-bragg-grating-measuring-system-for-simultaneous-monitoring-of-temperature-and-humidity-in-mechanical-ventilation
#17
Carlo Massaroni, Michele A Caponero, Rosaria D'Amato, Daniela Lo Presti, Emiliano Schena
During mechanical ventilation, the humidification of the dry air delivered by the mechanical ventilator is recommended. Among several solutions, heated wire humidifiers (HWHs) have gained large acceptance to be used in this field. The aim of this work is to fabricate a measuring system based on fiber Bragg grating (FBG) for the simultaneous monitoring of gas relative humidity (RH) and temperature, intended to be used for providing feedback to the HWHs' control. This solution can be implemented using an array of two FBGs having a different center wavelength...
April 2, 2017: Sensors
https://www.readbyqxmd.com/read/28363156/f-actin-reorganization-upon-de-and-rehydration-in-the-aeroterrestrial-green-alga-klebsormidium-crenulatum
#18
Kathrin Blaas, Andreas Holzinger
Filamentous actin (F-actin) is a dynamic network involved in many cellular processes like cell division and cytoplasmic streaming. While many studies have addressed the involvement of F-actin in different cellular processes in cultured cells, little is known on the reactions to environmental stress scenarios, where this system might have essential regulatory functions. We investigated here the de- and rehydration kinetics of breakdown and reassembly of F-actin in the streptophyte green alga Klebsormidium crenulatum...
March 21, 2017: Micron: the International Research and Review Journal for Microscopy
https://www.readbyqxmd.com/read/28363021/a-spinning-umbrella-carbon-monoxide-and-dinitrogen-bound-mb12-clusters-m-co-rh-ir
#19
Ranajit Saha, Susmita Kar, Sudip Pan, Gerardo Martínez-Guajardo, Gabriel Merino, Pratim K Chattaraj
Strong binding of carbon monoxide (CO) and dinitrogen (N2) by MB12(-) (M = Co, Rh, Ir) clusters results in a spinning umbrella-like structure. For OCMB12(-) and NNMB12(-) complexes, the bond dissociation energy values range within 50.3-67.7 kcal/mol and 25.9-35.7 kcal/mol, respectively, with the maximum value obtained in Ir followed by that in Co and Rh analogues. COMB12(-) complex is significantly less stable than the corresponding C-side bonded isomer. The associated dissociation processes for OCMB12(-) and NNMB12(-) into CO or N2 and MB12(-) are highly endergonic in nature at 298 K, implying their high thermochemical stability with respect to dissociation...
April 20, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28362092/spiro-metallaaromatics-of-pd-pt-rh-synthesis-and-characterization
#20
Yongliang Zhang, Junnian Wei, Yue Chi, Xuan Zhang, Wen-Xiong Zhang, Zhenfeng Xi
Since the concept of aromaticity represents one of the most funda-mental principles in chemistry, the search for unprecedented and exciting aromatic systems, therefore, continues to drive research in this area. Herein we report the synthesis and characterization of spiro metallaaromatics, in which the transition metal (Pd, Pt, or Rh) is the spiro atom, that cross-conjugates two aromatic five-membered metallacycles. These spiro metallaaromatics tend to take square planar geometries, with the dihedral angle being influenced by the steric repulsion between the α-positioned substituents...
March 31, 2017: Journal of the American Chemical Society
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