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https://www.readbyqxmd.com/read/28749543/new-multi-responsive-chromic-soft-materials-dynamic-interconversion-of-short-2-7-dicyanomethylenecarbazole-based-biradicaloid-and-corresponding-cyclophane-tetramer
#1
Maria Carmen Ruiz Delgado, Deliang Wang, Cristina Capel Ferrón, Jie Li, Sergio Gámez-Valenzuela, Rocio Ponce Ortiz, Juan T López Navarrete, Víctor Hernández Jolin, Xiaodi Yang, Miriam Peña Álvarez, Valentín García Baonza, František Hartl, Hongxiang Li
Herein, we report a quinodimethane-type molecule, 2,7-dicyanomethylene-9-(2-ethylhexyl)carbazole (1), one of the shortest π-conjugated biradicaloids reported to be stable in solution at ambient. This carbazole-based quinoidal precursor is able to form a macrocyclic -bonded tetramer (2). The resolved single crystal X-ray structure of tetramer 2 shows that four molecules of 1 are linked together through four long (CN)2C-C(CN)2 bonds (1.631 Å) resulting from coupling of the unpaired electrons in biradicaloid 1...
July 27, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28749503/crab-shell-induced-synthesis-of-ordered-macroporous-carbon-nanofiber-arrays-coupled-with-mnco2o4-nanoparticles-as-bifunctional-oxygen-catalysts-for-rechargeable-zn-air-batteries
#2
Duan Bin, Ziyang Guo, Andebet Gedamu Tamirat, Yuanyuan Ma, Yonggang Wang, Yongyao Xia
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are traditionally carried out using noble metals (such as Pt) and metal oxides (such as RuO2 and IrO2) as catalysts, respectively. Nevertheless, several key issues such as high cost, poor stability, and detrimental environmental effects limit the catalytic activity of these noble metal- and metal oxide-based catalysts. Herein, we have designed and synthesized macroporous carbon nanofiber arrays by using a natural crab shell template. Subsequently, spinel MnCo2O4 nanoparticles were embedded into the nitrogen-doped macroporous carbon nanofiber arrays (NMCNAs) by a hydrothermal method...
July 27, 2017: Nanoscale
https://www.readbyqxmd.com/read/28749489/optimization-of-ultra-performance-liquid-chromatography-uplc-with-fluorescence-detector-fld-method-for-the-quantitative-determination-of-selected-neurotransmitters-in-rat-brain
#3
Joanna Stragierowicz, Adam Daragó, Sławomir Brzeźnicki, Anna Kilanowicz
BACKGROUND: Glutamate (Glu) and γ-aminobutyric acid (GABA) are the main neurotransmitters in the central nervous system for excitatory and inhibitory processes, respectively. Monitoring these neurotransmitters is an essential tool in establishing pathological functions, among others in terms of occupational exposure to toxic substances. MATERIAL AND METHODS: We present modification of the HPLC (high-performance liquid chromatography) to the UPLC (ultra-performance liquid chromatography) method for the simultaneous determination of glutamate and γ-aminobutyric acid in a single injection...
July 26, 2017: Medycyna Pracy
https://www.readbyqxmd.com/read/28749447/enhanced-uptake-of-fe%C3%A2-o%C3%A2-nanoparticles-by-intestinal-epithelial-cells-in-a-state-of-inflammation
#4
Gang Zhou, Jin Zhang, Chun Pan, Naicheng Liu, Zhenheng Wang, Junfeng Zhang
Fe₃O₄ nanoparticles (Fe₃O₄ NPs) have been used for medical and drug applications, although the mechanisms of cellular uptake and transport need to be further evaluated under inflammatory conditions. In the present study, we investigated the uptake of Fe₃O₄ NPs (20, 50, 100, and 200 nm) by intestinal epithelial cells under inflammatory conditions via the light scattering of flow cytometry and inductively coupled plasma mass spectrometry (ICP-MS) techniques. The results of the correlation analysis indicated that the uptake ratios of Fe₃O₄ NPs by intestinal epithelial cells under inflammatory conditions were higher than those under the control conditions...
July 27, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28749432/screening-hepatotoxic-components-in-euodia-rutaecarpa-by-uhplc-qtof-ms-based-on-the-spectrum-toxicity-relationship
#5
Jian Liang, Yang Chen, Gang Ren, Wei Dong, Min Shi, Li Xiong, Jiankang Li, Jiahao Dong, Fei Li, Jinbin Yuan
Euodia rutaecarpa is a common traditional Chinese medicine (TCM) in clinical practice, having the ability to suppress pain and cease coughing; however, with the increasing reports showing that it is toxic, particularly hepatotoxic, the concerns raised by what cause its toxicity is growing. In the current study, an analysis method based on the spectrum effect has been employed to screen the major hepatotoxic components in Euodia rutaecarpa so that the toxic material's basis would be elucidated. A fingerprinting method of the Euodia rutaecarpa extracts (which were petroleum ether, chloroform, ethyl acetate, n-butanol, and water) using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometer (UHPLC-QTOF/MS) has been developed...
July 27, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28749415/association-between-toenail-magnesium-and-type-2-diabetes-in-chinese-adults
#6
Jiguo Zhang, Huijun Wang, Zhihong Wang, Ji Zhang, Bing Zhang
Previous studies have showed an inverse association between magnesium level and type 2 diabetes, but the results are inconsistent, and the evidence relates only to dietary and serum magnesium. Moreover, it is not certain how these findings are applicable to Asian people. This study was designed to examine the association between toenail magnesium and type 2 diabetes in Chinese adults. The sample was 5683 adults aged 18 years or older from the 2009 China Health and Nutrition Survey. We used hemoglobin A1c equal to or greater than 6...
July 27, 2017: Nutrients
https://www.readbyqxmd.com/read/28749345/noise-in-neuronal-and-electronic-circuits-a-general-modeling-framework-and-non-monte-carlo-simulation-techniques
#7
Deniz Kilinc, Alper Demir
The brain is extremely energy efficient and remarkably robust in what it does despite the considerable variability and noise caused by the stochastic mechanisms in neurons and synapses. Computational modeling is a powerful tool that can help us gain insight into this important aspect of brain mechanism. A deep understanding and computational design tools can help develop robust neuromorphic electronic circuits and hybrid neuroelectronic systems. In this paper, we present a general modeling framework for biological neuronal circuits that systematically captures the nonstationary stochastic behavior of ion channels and synaptic processes...
August 2017: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/28749342/broadband-vibration-detection-in-tissue-phantoms-using-a-fiber-fabry-perot-cavity
#8
Jack Barnes, Sijia Li, Apoorv Goyal, Purang Abolmaesumi, Parvin Mousavi, Hans-Peter Loock
A fiber optic vibration sensor is developed and characterized with an ultra-wide dynamic sensing range, from less than 1 Hz to clinical ultrasound frequencies near 6 MHz. The vibration sensor consists of a matched pair of fiber Bragg gratings coupled to a custom-built signal processing circuit. The wavelength of a laser diode is locked to one of the many cavity resonances using the Pound-Drever-Hall scheme. A calibrated piezoelectric vibration element was used to characterize the sensor's strain, temperature, and noise responses...
July 24, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28749340/super-resolution-imaging-of-synaptic-and-extra-synaptic-ampa-receptors-with-different-sized-fluorescent-probes
#9
Sang Hak Lee, Chaoyi Jin, En Cai, Pinghua Ge, Yuji Ishitsuka, Kai Wen Teng, Andre A de Thomaz, Duncan L Nall, Murat Baday, Okunola Jeyifous, Daniel Demonte, Christopher M Dundas, Sheldon Park, Jary Y Delgado, William N Green, Paul R Selvin
Previous studies tracking AMPA receptor (AMPAR) diffusion at synapses observed a large mobile extrasynaptic AMPAR pool. Using super-resolution microscopy, we examined how fluorophore size and photostability affected AMPAR trafficking outside of, and within, post-synaptic densities (PSDs) from rats. Organic fluorescent dyes (≈4 nm), quantum dots, either small (≈10 nm diameter; sQDs) or big (>20 nm; bQDs), were coupled to AMPARs via different-sized linkers. We find that >90% of AMPARs labeled with fluorescent dyes or sQDs were diffusing in confined nanodomains in PSDs, which were stable for 15 minutes or longer...
July 27, 2017: ELife
https://www.readbyqxmd.com/read/28749339/pten-controls-glandular-morphogenesis-through-a-juxtamembrane-%C3%AE-arrestin1-arhgap21-scaffolding-complex
#10
Arman Javadi, Ravi K Deevi, Emma Evergren, Elodie Blondel-Tepaz, George S Baillie, Mark Gh Scott, Frederick Charles Campbell
PTEN controls three-dimensional (3D) glandular morphogenesis by coupling juxtamembrane signalling to mitotic spindle machinery. While molecular mechanisms remain unclear, PTEN interacts through its C2 membrane-binding domain with the scaffold protein β-Arrestin1. Because β-Arrestin1 binds and suppresses the Cdc42 GTPase-activating protein ARHGAP21, we hypothesize that PTEN controls Cdc42-dependent morphogenic processes through a β-Arrestin1-ARHGAP21 complex. Here we show that PTEN knockdown (KD) impairs β-Arrestin1 membrane localization, β-Arrestin1-ARHGAP21 interactions, Cdc42 activation, mitotic spindle orientation and 3D glandular morphogenesis...
July 27, 2017: ELife
https://www.readbyqxmd.com/read/28749146/rigid-dendritic-shaped-porphyrin-antennas-controlling-cas-cades-of-unidirectional-energy-funneling-and-charge-trans-fer
#11
Maximilian Wolf, Astrid Herrmann, Andreas Hirsch, Dirk M Guldi
Porphyrin arrays, which consist of three peripheral ZnPs and a central H2P - all rigidly linked to each other -serve as light harvesting antennas as well as electron donors and are flexibly coupled to an electron accepting C60 to realize the unidirectional flow of i) excited state energy from the ZnPs at the periphery to the H2P, ii) electrons to C60, and iii) holes to H2P and, subsequently, to ZnP. Dynamics following photoexcitation are elucidated by time resolved transient absorption measurements on the femto-, pico, nano-, and microsecond time scales and are examined by multiwavelength as well as target analyses...
July 27, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28749132/universal-ratiometric-photoelectrochemical-bioassay-with-target-nucleotide-transduction-amplification-and-electron-transfer-tunneling-distance-regulation-strategies-for-ultrasensitive-determination-of-microrna-in-cells
#12
Yingning Zheng, Wenbin Liang, Chengyi Xiong, Ying Zhuo, Yaqin Chai, Ruo Yuan
A universal ratiometric photoelectrochemical (PEC) bioassay, which could be readily expanded for untrasensitive determination of various targets in complex biological matrix, was established by coupling a target-nucleotide transduction-amplification with DNA nanomachine mediated electron-transfer tunneling distance regulation strategies. With the help of target-nucleotide transduction-amplification strategy, the one input target signal could be transducted to corresponding multiple output DNA signals by nucleotide specific recognition technology, simultaneously leading to an efficient signal amplification for target...
July 27, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28749130/fluorination-of-boron-doped-diamond-film-electrodes-for-minimization-of-perchlorate-formation
#13
Pralay Gayen, Brian P Chaplin
This research investigated the effects of surface fluorination on both rates of organic compound oxidation (phenol, terephthalic acid (TA)) and ClO4(-) formation at boron-doped diamond (BDD) film anodes at 22(o) C. Different fluorination methods (i.e., electrochemical oxidation with perfluorooctanoic acid (PFOA), radio frequency plasma, and silanization) were used to incorporate fluorinated moieties on the BDD surface, which was confirmed by X-ray photoelectron spectroscopy (XPS). The silanization method was found to be the most effective fluorination method using a 1H, 1H, 2H, 2H perfluorodecyltrichlorosilane (aliphatic silane) precursor to form a self assembled monolayer (SAM) on the oxygenated BDD surface...
July 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28749065/concise-review-the-high-cost-of-high-tech-medicine-planning-ahead-for-market-access
#14
REVIEW
Dawn Driscoll, Stephanie Farnia, Panos Kefalas, Richard T Maziarz
Cellular therapies and other regenerative medicines are emerging as potentially transformative additions to modern medicine, but likely at a staggering financial cost. Public health care systems' budgets are already strained by growing and aging populations, and many private insurer's budgets are equally stretched. The current systems that most payers employ to manage their cash flow are not structured to absorb a sudden onslaught of very expensive prescriptions for a large portion of their covered population...
August 2017: Stem Cells Translational Medicine
https://www.readbyqxmd.com/read/28749013/physiological-versus-pharmacological-signalling-to-myosin-phosphorylation-in-airway-smooth-muscle
#15
Ning Gao, Ming-Ho Tsai, Audrey N Chang, Weiqi He, Cai-Ping Chen, Minsheng Zhu, Kristine E Kamm, James T Stull
Ca(2+) /calmodulin activation of myosin light chain kinase (MLCK) initiates myosin regulatory light chain (RLC) phosphorylation for smooth muscle contraction with subsequent dephosphorylation for relaxation by myosin light chain phosphatase (MLCP) containing regulatory (MYPT1) and catalytic (PP1cδ) subunits. RLC phosphorylation-dependent force development is regulated by distinct signalling modules involving protein phosphorylations. We investigated responses to cholinergic agonist treatment versus neurostimulation by electric field stimulation (EFS) in bovine tracheal smooth muscle...
July 27, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28748976/syntheses-structures-and-magnetic-properties-of-the-lanthanide-complexes-of-the-pyrimidyl-substituted-nitronyl-nitroxide-radical
#16
Jian Wang, Hao Miao, Zhao-Xin Xiao, Yan Zhou, Lin-Dan Deng, Yi-Quan Zhang, Xin-Yi Wang
Four 2p-4f Ln(III)-radical complexes, [(NIT-2-Pm)Ln(hfac)3]·0.5C7H16 (NIT-2-Pm = 2-pyrimidyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide, hfac = hexafluoroacetylacetonato, Ln = Tb (1), Dy (2), Ho (3) and Er (4)), and four 4f-2p-4f Ln(III)-radical-Ln(III) complexes, [(μ-NIT-2-Pm)Ln2(hfac)6(H2O)2]·0.5C7H16 (Ln = Tb (5), Dy (6), Ho (7) and Er (8)) have been synthesized and characterized structurally and magnetically. These compounds can be selectively obtained by controlling the reaction ratio of Ln(hfac)3·2H2O to the radical ligand NIT-2-Pm...
July 27, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28748915/the-endoplasmic-reticulum-stress-autophagy-pathway-is-involved-in-apelin-13-induced-cardiomyocyte-hypertrophy-in-vitro
#17
Feng Xie, Di Wu, Shi-Fang Huang, Jian-Gang Cao, He-Ning Li, Lu He, Mei-Qing Liu, Lan-Fang Li, Lin-Xi Chen
Apelin is the endogenous ligand for the G protein-coupled receptor APJ, and plays important roles in the cardiovascular system. Our previous studies showed that apelin-13 promotes the hypertrophy of H9c2 rat cardiomyocytes through the PI3K-autophagy pathway. The aim of this study was to explore what roles ER stress and autophagy played in apelin-13-induced hypertrophy of cardiomyocytes in vitro. Treatment of H9c2 cells with apelin-13 (0.001-2 μmol/L) dose-dependently increased the production of ROS and the expression levels of NADPH oxidase 4 (NOX4)...
July 27, 2017: Acta Pharmacologica Sinica
https://www.readbyqxmd.com/read/28748760/visible-light-therapy-molecular-mechanisms-and-therapeutic-opportunities
#18
Zandra C Félix Garza, Matthias Born, Peter A J Hilbers, Natal A W van Riel, Joerg Liebmann
Visible light is absorbed by photoacceptors in pigmented and non-pigmented mammalian cells, activating signaling cascades and downstream mechanisms that lead to the modulation of cellular processes. Most studies have investigated the molecular mechanisms and therapeutic applications of UV and the red to near infrared regions of the visible spectrum. However, considerably less effort has been dedicated to the UV-free blue part of the spectrum. In this review we discuss the current advances in the understanding of the molecular photoacceptors, downstream signaling mechanisms and the corresponding therapeutic opportunities in the context of inflammatory skin conditions of blue light photoreception in mammalian cells...
July 27, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28748736/identification-of-bioactive-constituents-from-different-fractions-of-stems-of-cuscuta-reflexa-roxb-using-gc-ms
#19
Diptirani Rath, Sandeep Kumar Panigrahi, Durga Madhab Kar, Laxmidhar Maharana
The GC-MS analysis of fractions of methanol extract of stem of Cuscuta reflexa (Family Convolvulaceae) was carried out using a THERMO TRACE 1300 Gas Chromatograph equipped and coupled to a mass detector THERMO TSQ 8000 spectrometer with an TG 5MS (30 m × 0.25 mm, 0.25 μm) of capillary column. Database of National Institute of Standards and Technology (NIST) library was used to identify the components. GC-MS revealed two known compounds i.e. 2-Methoxy-4-vinyl phenol (6.80%) and Benzofuran-2,3-dihydro (20...
July 27, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28748700/wittig-cyclization-of-%C3%AF-hydroxy-hemiacetals-synthesis-of-aspicilin
#20
René Schmidt, Michael Ostermeier, Rainer Schobert
The polyhydroxylated 18-membered lichen macrolide (+)-aspicilin was synthesized in 12 steps and 17% yield (longest linear sequence) starting from D-mannose and (S)-propylene oxide as the source of the stereogenic centers. Key steps were a palladium-catalyzed Csp3X-Csp3ZnX Negishi cross-coupling affording an ω-hydroxy hemiacetal which was macrocyclized via a domino addition-Wittig olefination reaction with the cumulated ylide Ph3PCCO. This synthetic approach also allowed a regioselective glycosylation of 6-OH of aspicilin with D desosamine, a quick entry to chimeric macrolides with potential antibiotic activity...
July 27, 2017: Journal of Organic Chemistry
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