1,360,679 results match your criteria Chemical Peels


Evidence that a catalytic glutamate and an 'Arginine Toggle' act in concert to mediate ATP hydrolysis and mechanochemical coupling in a viral DNA packaging motor.

Nucleic Acids Res 2018 Dec 12. Epub 2018 Dec 12.

Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA.

ASCE ATPases include ring-translocases such as cellular helicases and viral DNA packaging motors (terminases). These motors have conserved Walker A and B motifs that bind Mg2+-ATP and a catalytic carboxylate that activates water for hydrolysis. Here we demonstrate that Glu179 serves as the catalytic carboxylate in bacteriophage λ terminase and probe its mechanistic role. Read More

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December 2018

RNAi of Sterol Methyl Transferase1 Reveals its Direct Role in Diverting Intermediates Towards Withanolide/ Phytosterol Biosynthesis in Withania somnifera.

Plant Cell Physiol 2018 Dec 12. Epub 2018 Dec 12.

Laboratory of Aromatic Plants and Chiral Separation, Chemical Sciences Division, CSIR-Central Institute of Medicinal and Aromatic Plants (CIMAP), India.

The medicinal properties of Ashwagandha (Withania somnifera) are accredited to a group of compounds called as withanolides. 24-methylene cholesterol is the intermediate for sterol biosynthesis and a proposed precursor of withanolides biogenesis. But, conversion of 24-methylene cholesterol to withaferin A and other withanolides has not yet been biochemically dissected. Read More

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December 2018

DNA damage and repair in the female germline: contributions to ART.

Hum Reprod Update 2018 Dec 12. Epub 2018 Dec 12.

Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, University of Newcastle, Callaghan, NSW, Australia.

Background: DNA integrity and stability are critical determinants of cell viability. This is especially true in the female germline, wherein DNA integrity underpins successful conception, embryonic development, pregnancy and the production of healthy offspring. However, DNA is not inert; rather, it is subject to assault from various environment factors resulting in chemical modification and/or strand breakage. Read More

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December 2018

Nanocomposite of polypyrrol and silica rods-gold nanoparticles core-shell as an ammonia sensor.

Nanotechnology 2018 Dec 12. Epub 2018 Dec 12.

Nanomaterials Laboratory, Centre for Materials for Electronics Technology, Panchwati, Off Pashan Road, Pune-411008, Pune, Maharashtra, 411008, INDIA.

Ammonia is widely needed in chemical industry as well as in fertilizers for agriculture. However, in small as well as large quantities it is not only hazardous for human health but also for our ecosystem. Therefore, ammonia sensing at low concentration with high sensitivity, selectivity and low response time as well as recovery time is important. Read More

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December 2018

Self-assembled CpG oligodeoxynucleotides conjugated hollow gold nanospheres to enhance cancer-associated immunostimulation.

Colloids Surf B Biointerfaces 2018 Dec 3;175:248-255. Epub 2018 Dec 3.

Key Laboratory of Coal Conversion & New Carbon Materials of Hubei Province, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China. Electronic address:

To realize efficiently cellular uptake and enhance the immunostimulation, thiolated cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs) were self-assembled on hollow gold nanospheres (HGNs) to form CpG-HGNs. The cellular uptake of CpG-HGNs in immune cells was studied in RAW 264.7 cells. Read More

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December 2018

Development of a Human iPSC Cardiomyocyte-Based Scoring System for Cardiac Hazard Identification in Early Drug Safety De-risking.

Stem Cell Reports 2018 Dec;11(6):1365-1377

Global Safety Pharmacology, Non-Clinical Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340 Beerse, Belgium.

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as a promising cardiac safety platform, demonstrated by numerous validation studies using drugs with known cardiac adverse effects in humans. However, the challenge remains to implement hiPSC-CMs into cardiac de-risking of new chemical entities (NCEs) during preclinical drug development. Here, we used the calcium transient screening assay in hiPSC-CMs to develop a hazard score system for cardiac electrical liabilities. Read More

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December 2018

Screening-Based Chemical Approaches to Unravel Stem Cell Biology.

Authors:
Shuibing Chen

Stem Cell Reports 2018 Dec;11(6):1312-1323

Department of Surgery and Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA. Electronic address:

Cell-permeable compounds provide a convenient and efficient approach to manipulate biological processes. A number of compounds controlling stem cell self-renewal, survival, differentiation, and reprogramming have been identified through high-throughput/content screens. Using these powerful chemical tools, strategies have been developed to direct human pluripotent stem cell (hPSC) differentiation to functional cells. Read More

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December 2018

An RpaA-Dependent Sigma Factor Cascade Sets the Timing of Circadian Transcriptional Rhythms in Synechococcus elongatus.

Cell Rep 2018 Dec;25(11):2937-2945.e3

Howard Hughes Medical Institute, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, MA 02138, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA. Electronic address:

The circadian clock of the cyanobacterium Synechococcus elongatus PCC 7942 drives oscillations in global mRNA abundances with 24-hr periodicity under constant light conditions. The circadian clock-regulated transcription factor RpaA controls the timing of circadian gene expression, but the mechanisms underlying this control are not well understood. Here, we show that four RpaA-dependent sigma factors-RpoD2, RpoD6, RpoD5, and SigF2-are sequentially activated downstream of active RpaA and are required for proper expression of circadian mRNAs. Read More

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December 2018

Photo-induced tyrosine side chain fragmentation in IgG4-Fc: mechanisms and solvent isotope effects.

Mol Pharm 2018 Dec 12. Epub 2018 Dec 12.

Immunoglobulin gamma (IgG) monoclonal antibodies (mAbs) are glycoproteins that have emerged as powerful and promising protein therapeutics. During the process of production, storage and transportation, exposure to ambient light is inevitable, which can cause protein physical and chemical degradation. For mechanistic studies of photo-degradation, we have exposed IgG4-Fc to UV light. Read More

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December 2018
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Bacillus subtilis STU6 ameliorates iron deficiency in tomato by enhancement of polyamine-mediated iron remobilization.

J Agric Food Chem 2018 Dec 12. Epub 2018 Dec 12.

Iron (Fe) deficiency often triggers arginine overproduction in plants. However, it remains elusive whether Fe deficiency-induced increases of arginine levels are involved in beneficial rhizobacteria recruitment and that the mechanism underlying rhizobacteria induced plant Fe deficiency tolerance. Here, Bacillus subtilis STU6 increased soluble Fe content in tomato, thereby alleviating Fe deficiency-induced chlorosis. Read More

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December 2018

Orphan Receptor GPR88 as an Emerging Neurotherapeutic Target.

ACS Chem Neurosci 2018 Dec 12. Epub 2018 Dec 12.

While G protein-coupled receptors (GPCRs) are recognized as pivotal drug targets involved in multiple physiological and pathological processes, the majority of GPCRs including orphan GPCRs (oGPCRs) are unexploited. GPR88, a brain-specific oGPCR with particularly robust expression in the striatum, regulates diverse brain and behavioral functions including cognition, mood, movement control and reward-based learning, and is thus emerging as a novel drug target for CNS disorders including schizophrenia, Parkinson's disease, anxiety and addiction. Nevertheless, no effective GPR88 synthetic ligands have yet entered into clinical trials and GPR88 endogenous ligands remain unknown. Read More

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December 2018

Impacts and interactions of organic compounds with chlorine sanitizer in recirculated and reused produce processing water.

PLoS One 2018 12;13(12):e0208945. Epub 2018 Dec 12.

U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Environmental Microbiology and Food Safety Laboratory, Beltsville, Maryland, United States of America.

Water conservation and economics dictate that fresh produce processors reuse/recirculate the process water. However, the ensuing accumulation of organic matter in water depletes the chlorine sanitizer required for food safety. In this study, we comprehensively investigated chemical compounds that are responsible for water quality in relation to chemical oxygen demand (COD) and chlorine demand (CLD), the two most critical factors associated with water treatment and chlorine replenishment. Read More

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December 2018

Physicochemical and microbiological characterization of the sensory deviation responsible for the origin of the special sherry wines "palo cortado" type.

PLoS One 2018 12;13(12):e0208330. Epub 2018 Dec 12.

Department of Chemical Engineering and Food Technology, Faculty of Sciences, University of Cadiz, Cadiz, Spain.

The aim of this study was to characterize the biochemical changes and microbiological processes involved in the sensory deviation of "sobretablas" wines during biological aging, which leads to the origin of special or rare "palo cortado" wines. Industrial trials of biological aging of "sobretablas" wines with the potential for the development of lactic acid bacteria (LAB) were performed to study this phenomenon. The results showed that sensory deviation was due to the development of malolactic fermentation (MLF) together with an attenuated aerobic metabolism of "flor" yeast. Read More

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December 2018

Transgenerational effects of ungulates and pre-dispersal seed predators on offspring success and resistance to herbivory.

PLoS One 2018 12;13(12):e0207553. Epub 2018 Dec 12.

Departamento de Zoología, Universidad de Granada, Granada, Spain.

Herbivorous mammals and insect pre-dispersal seed predators are two types of herbivores that, despite their functional and morphological differences, tend to severely impact many plant species, highly decreasing their seed production and even imperiling the performance of their offspring through transgenerational effects. However, how they influence offspring resistance to herbivory remains largely unknown. In this study we experimentally examined the effects of ungulates and pre-dispersal seed predators on seed quality as well as on the emergence, survival and resistance to herbivory of the seedlings of a semiarid herb. Read More

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December 2018

Live nanoscopic to mesoscopic topography reconstruction with an optical microscope for chemical and biological samples.

PLoS One 2018 12;13(12):e0207881. Epub 2018 Dec 12.

LAI, Aix Marseille Univ, CNRS, INSERM, Marseille, France.

Macroscopic properties of physical and biological processes like friction, wetting, and adhesion or cell migration are controlled by interfacial properties at the nanoscopic scale. In an attempt to bridge simultaneously investigations at different scales, we demonstrate here how optical microscopy in Wet-Surface Ellipsometric Enhanced Contrast (Wet-SEEC) mode offers imaging and measurement of thin films at solid/liquid interfaces in the range 1-500 nm with lateral optical resolution. A live, label-free and noninvasive methodology integrated with microfluidic devices allowed here characterization of polymers and proteins patterns together with corresponding phenotypes of living cells. Read More

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December 2018

Social Stress Affects Colonic Inflammation, the Gut Microbiome, and Short Chain Fatty Acid Levels and Receptors.

J Pediatr Gastroenterol Nutr 2018 Dec 11. Epub 2018 Dec 11.

Center for Microbial Pathogenesis, The Research Institute, Nationwide Children's Hospital, Columbus, OH, United States.

Objectives: Gastrointestinal disorders, such as inflammatory bowel diseases (IBD) and functional gastrointestinal disorders (FGID), involve disrupted homeostatic interactions between the microbiota and the host. Both disorders are worsened during stress, and in laboratory mice, stress exposure has been shown to change the composition of the gut microbiome. Stress-induced changes to the microbiome exacerbate intestinal inflammation and alter intestinal motility in mice. Read More

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December 2018

LongShengZhi capsule reduces established atherosclerotic lesions in apoE deficient mice by ameliorating hepatic lipid metabolism and inhibiting inflammation.

J Cardiovasc Pharmacol 2018 Dec 10. Epub 2018 Dec 10.

College of Biomedical Engineering, Hefei University of Technology, Hefei, China.

Disorders of lipid metabolism and inflammation play an important role in atherosclerosis. LongShengZhi capsule (LSZ), a Chinese herbal medicine, has been used for treatment of patients with vascular diseases for many years. Herein, we determined the effect of LSZ on the progression of established atherosclerotic lesions in apoE deficient (apoE) mice. Read More

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December 2018

Combination of ST2 and B-type natriuretic peptide in diabetic patients with acute heart failure: relation with ventricular stiffness and outcome.

J Cardiovasc Med (Hagerstown) 2018 Dec 11. Epub 2018 Dec 11.

Cardiovascular Diseases Unit, Department of Internal Medicine, Le Scotte Hospital, University of Siena.

Background: Diabetes is a common disease in heart failure and its prevalence ranges from 10 to 30%. ST-2 is a novel biomarker of myocardial fibrosis and remodelling in heart failure and may be involved in the inflammatory process of diabetes mellitus. In this study, we sought: to evaluate levels of ST-2 and B-type natriuretic peptide (BNP) in groups with acute heart failure with and without diabetes; to analyse the prognostic impact of ST-2 over a 6-month follow-up period. Read More

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December 2018

In Vivo Analysis of Urinary Stones With Dual-Energy Computed Tomography.

J Comput Assist Tomogr 2018 Dec 12. Epub 2018 Dec 12.

Biochemistry, Faculty of Medicine, Selcuk University, Konya, Turkey.

Objective: Formation mechanisms and treatment of the urinary stones are different, depending on their chemical structure. Therefore, determining the stone type plays a key role in planning treatment and preventive measures. Computed tomography (CT), with the use of dual-energy technology in recent years, has made it possible to do in vivo analysis of urinary stones. Read More

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December 2018

Masseter Muscle Volume Changes Evaluated by 3-Dimensional Computed Tomography After Repeated Botulinum Toxin A Injections in Patients With Square Facial Morphology.

Ann Plast Surg 2019 Jan;82(1S Suppl 1):S29-S32

From the Graduate Institute of Chemical and Materials Engineering, College of Engineering, Chang Gung University, Taoyuan, Taiwan, and.

Introduction: Botulinum neurotoxin A (BoNT-A) is a minimally invasive and technically straightforward treatment of masseter muscle (MM) volume reduction and facial contouring, but the literature on its long-term effect on MM volume remains unclear.

Objective: This study aimed to assess quantitatively for progressive volume changes of lower facial contour after 3 BoNT-A injections in patients with bilateral MM hypertrophy causing square facial morphology using 3-dimensional computed tomographic scans.

Materials And Methods: Ten female patients with square facial morphology due to bilateral MM hypertrophy were recruited to, and 6 completed, this clinical study. Read More

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January 2019

Chemical activation of the ethylene signalling pathway promotes Fusarium graminearum resistance in detached wheat heads.

Phytopathology 2018 Dec 12. Epub 2018 Dec 12.

University of Lethbridge, Department of Biological Sciences, Lethbridge, Alberta, Canada ;

Plant signalling hormones, such as ethylene, have been shown to affect the host response to various pathogens. Often the resistance responses to necrotrophic fungi are mediated through synergistic interactions of ethylene (ET) with the jasmonate signalling pathway. On the other hand, ethylene is also an inducer of senescence and cell death, which could be beneficial for some invading necrotrophic pathogens. Read More

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December 2018

Occupational exposure to gaseous and particulate contaminants originating from additive manufacturing of liquid, powdered and filament plastic materials and related post-processes.

J Occup Environ Hyg 2018 Dec 12:1-36. Epub 2018 Dec 12.

a School of Engineering and Technology , Savonia University of Applied Sciences , Kuopio , Finland.

The aim of this study was to measure the concentrations of gaseous and particulate contaminants originated from additive manufacturing operations and post-processes in an occupational setting when plastics were used as feedstock materials. Secondary aims were to evaluate the concentration levels based on proposed exposure limits and target values and to propose means to reduce exposure to contaminants released in additive manufacturing processes. Volatile organic compounds were sampled with Tenax® TA adsorption tubes and analyzed with thermo desorption gas chromatography-mass spectrometry instrument. Read More

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December 2018

Advancements in Life Cycle Human Exposure and Toxicity Characterization.

Environ Health Perspect 2018 Dec;126(12):125001

16 School of Public Health, University of California , Berkeley, California, USA.

Background: The Life Cycle Initiative, hosted at the United Nations Environment Programme, selected human toxicity impacts from exposure to chemical substances as an impact category that requires global guidance to overcome current assessment challenges. The initiative leadership established the Human Toxicity Task Force to develop guidance on assessing human exposure and toxicity impacts. Based on input gathered at three workshops addressing the main current scientific challenges and questions, the task force built a roadmap for advancing human toxicity characterization, primarily for use in life cycle impact assessment (LCIA). Read More

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December 2018
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A Combined Automated Reaction Pathway Searches and Sparse Modeling Analysis for Catalytic Properties of Lowest Energy Twins of Cu.

J Phys Chem A 2018 Dec 12. Epub 2018 Dec 12.

In nanocatalysis a growing attention has recently been given to investigation of energetically low-lying structural isomers of atomic clusters, because some isomers can demonstrate better catalytic activity than the most stable structures. In this study, we present a comparative investigation of a catalytic activity for NO dissociation of a pair of the energetically degenerated isomers of Cu13 cluster having C2 and Cs symmetries. It is shown that although these isomers have similar structural, electronic, and optical properties, they can possess very different catalytic activity. Read More

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December 2018

Evaluating Density Functionals by Examining Molecular Structures, Chemical Bonding, and Relative Energies of Mononuclear Ru-Cl-H-PR Isomers.

J Phys Chem A 2018 Dec 12. Epub 2018 Dec 12.

In order to define a robust level of theory using density functionals for investigating the reactivity of ruthenium complexes, we used benchmark wave function theory, with saturated basis sets to validate GGA, meta-GGA, and hyper-GGA functionals in the presence and absence of empirical dispersion and range-separated corrections. We first selected potentially suitable functionals that gave accurate predictions of the relative energetics of coordination isomers. These functionals were further evaluated for the chemical accuracy of their predicted geometric and electronic structures. Read More

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December 2018

Iterative design and optimization of initially inactive Proteolysis Targeting Chimeras (PROTACs) identify VZ185 as a potent, fast and selective von Hippel-Lindau (VHL)-based dual degrader probe of BRD9 and BRD7.

J Med Chem 2018 Dec 12. Epub 2018 Dec 12.

Developing PROTACs to redirect the ubiquitination activity of E3 ligases and potently degrade a target protein within cells can be a lengthy and unpredictable process, and it remains unclear whether any combination of E3 and target might be productive for degradation. We describe a probe-quality degrader for a ligase-target pair deemed unsuitable: the von Hippel-Lindau (VHL) and BRD9, a bromodomain-containing subunit of the SWI/SNF chromatin remodeling complex BAF. VHL-based degraders could be optimized from suboptimal compounds in two rounds by systematically varying conjugation patterns and linkers, and monitoring cellular degradation activities, kinetic profiles, and ubiquitination, as well as ternary complex formation thermodynamics. Read More

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December 2018

Ab Initio Prediction of Proton Exchange Barriers for Alkanes at Brønsted Sites of Zeolite H-MFI.

J Am Chem Soc 2018 Dec 12. Epub 2018 Dec 12.

Institut für Chemie , Humboldt-Universität zu Berlin , Unter den Linden 6 , 10099 Berlin , Germany.

A hybrid of high level and low level quantum mechanics (QM) methods has been employed to predict intrinsic and apparent energy barriers for the direct proton exchange mechanism of methane, ethane, propane, n-butane, and i-butane on Brønsted sites of H-MFI. The specific hybrid MP2:PBE+D2 + ΔCC implementation used is known to yield the so-called "chemical accuracy" (±4 kJ/mol). Whereas the apparent enthalpy barriers decrease with increasing C number from 104 to 63 kJ/mol, in line with the decreasing heat of adsorption, the intrinsic enthalpy barriers are constant within 124-127 kJ/mol at 500 K. Read More

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December 2018

Single-Atom Alloys as a Reductionist Approach to the Rational Design of Heterogeneous Catalysts.

Acc Chem Res 2018 Dec 12. Epub 2018 Dec 12.

Department of Chemistry , Tufts University , 62 Talbot Avenue , Medford , Massachusetts 02155 United States.

Heterogeneous catalysts are workhorses in the industrial production of most commodity and specialty chemicals, and have widespread energy and environmental applications, with the annual market value of the catalysts themselves reaching almost $20 billion in 2018. These catalysts are complex, comprising multicomponent materials and multiple structures, making their rational design challenging, if not impossible. Furthermore, typical active metals like Pt, Pd, and Rh are expensive and can be susceptible to poisoning by CO, coking, and they are not always 100% selective. Read More

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December 2018

Energy-Degeneracy-Driven Covalency in Actinide Bonding.

J Am Chem Soc 2018 Dec 12. Epub 2018 Dec 12.

Los Alamos National Laboratory , P.O. Box 1663, Los Alamos , New Mexico 87545 , United States.

Evaluating the nature of chemical bonding for actinide elements represents one of the most important and long-standing problems in actinide science. We directly address this challenge and contribute a Cl K-edge X-ray absorption spectroscopy and relativistic density functional theory study that quantitatively evaluates An-Cl covalency in AnCl (An = Th, U, Np, Pu). The results showed significant mixing between Cl 3p- and An 5f- and 6d-orbitals (t*/t* and t*/e *), with the 6d-orbitals showing more pronounced covalent bonding than the 5f-orbitals. Read More

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December 2018

Elevated Manganese Concentrations in United States Groundwater, Role of Land Surface-Soil-Aquifer Connections.

Environ Sci Technol 2018 Dec 12. Epub 2018 Dec 12.

U.S. Geological Survey , 4165 Spruance Road , San Diego , California 92101 , United States.

Chemical data from 43 334 wells were used to examine the role of land surface-soil-aquifer connections in producing elevated manganese concentrations (>300 μg/L) in United States (U.S.) groundwater. Read More

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December 2018

A novel anaerobic electrochemical membrane bioreactor with CNTs hollow fiber membrane cathode to mitigate membrane fouling and enhance energy recovery.

Environ Sci Technol 2018 Dec 12. Epub 2018 Dec 12.

A novel anaerobic treatment system that combines the impact of applied voltage with membrane filtration over carbon nanotubes hollow fiber membranes (CNTs-HFMs) was developed at low-temperature (15-20 °C) to mitigate membrane fouling, treat wastewater and recover energy (CH4). Herein, electro-assisted CNTs-HFMs served a dual function as the cathode and membrane filtration. In contrast with other two anaerobic membrane bioreactors (AnMBRs; polyvinylidene fluoride hollow fiber membranes and CNTs-HFMs without electro-assistance), the CNTs-HFMs with electro-assistance (-1. Read More

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December 2018
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Spectro-electrochemical Studies on [Ru(TAP)(dppz)]-Insights into the Mechanism of its Photosensitized Oxidation of Oligonucleotides.

Inorg Chem 2018 Dec 12. Epub 2018 Dec 12.

School of Chemical Sciences , Dublin City University , Dublin 9 , Ireland.

[Ru(TAP)(dppz)] (TAP = 1,4,5,8-tetraazaphenanthrene; dppz = dipyrido[3,2- a:2',3'- c]phenazine) is known to photo-oxidize guanine in DNA. Whether this oxidation proceeds by direct photoelectron transfer or by proton-coupled electron transfer is still unknown. To help distinguish between these mechanisms, spectro-electrochemical experiments have been carried out with [Ru(TAP)(dppz)] in acetonitrile. Read More

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December 2018

Proton-Conductive Cocrystals of Twin Isomers of Coordination Polymers in Situ Formed by Keggin Anions and Cu(II)-4,4'-Bis(hydroxymethyl)-2,2'-bipyridine Complex Moieties.

Inorg Chem 2018 Dec 12. Epub 2018 Dec 12.

School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , P. R. China.

Cocrystals and isomers, two well-known unique concepts in supramolecular chemistry, are rarely put together until now. For the first time, we report three unprecedented and interesting cocrystals of twin isomers of coordination polymers (CPs) in situ formed by typical Keggin anions and Cu(II)-4,4'-bis(hydroxymethyl)-2,2'-bipyridine (Cu(II)-HL) complex moieties. In cocrystals 1-3, the Cu(II)-HL complex moieties are quadrisupported on Keggin-type anions through W(Mo)-Ot-Cu-Ot-W(Mo) (Ot is the terminal O atom) links in the crystal to form two twin ionic/neutral CPs with a fixed chemical stoichiometry. Read More

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December 2018

Chemical Space and Biological Target Network of Anti-inflammatory Natural Products.

J Chem Inf Model 2018 Dec 12. Epub 2018 Dec 12.

Natural products (NPs) are a promising source of anti-inflammatory molecules for the development of drugs. Despite there being an abundance of reports of large numbers of NPs having bioactivity in preliminary cell-based assays of anti-inflammatory potential, their further optimization and exploration is limited by lack of a comprehensive understanding of their effective scaffold structure or biological targets. To facilitate target-based studies of anti-inflammatory NPs, the details of 665 NPs reported to have anti-inflammatory activity were extracted from the literature and compiled into a dataset we termed InflamNat. Read More

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December 2018

Lasing Supraparticles Self-Assembled from Nanocrystals.

ACS Nano 2018 Dec 12. Epub 2018 Dec 12.

One of the most attractive foreseen commercial applications of semiconductor nanocrystals (NCs) is their use in lasers. Thanks to their high quantum yield, tunable optical properties, photostability and wet-chemical processability, NCs have arisen as promising gain material. Most of these applications, however, rely on incorporation of NCs in lasing cavities separately produced using sophisticated fabrication methods and often difficult to manipulate. Read More

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December 2018

Singular dynamics in the failure of soft adhesive contacts.

Soft Matter 2018 Dec 12. Epub 2018 Dec 12.

Department of Physics, Williams College, Williamstown, MA, USA. and Department of Materials, ETH Zürich, Zürich, Switzerland.

We characterize the mechanical recovery of compliant silicone gels following adhesive contact failure. We establish broad, stable adhesive contacts between rigid microspheres and soft gels, then stretch the gels to large deformations by pulling quasi-statically on the contact. Eventually, the adhesive contact begins to fail, and ultimately slides to a final contact point on the bottom of the sphere. Read More

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December 2018

Spin-state dependence of the structural and vibrational properties of solvated iron(ii) polypyridyl complexes from AIMD simulations: II. aqueous [Fe(tpy)]Cl.

Phys Chem Chem Phys 2018 Dec 12. Epub 2018 Dec 12.

Département de Chimie Physique, Université de Genève, Quai E. Ansermet 30, CH-1211 Genève 4, Switzerland.

We report a detailed ab initio molecular dynamics (AIMD) study of the structural and vibrational properties of aqueous [Fe(tpy)2]2+ (tpy = 2,2':6',2''-ter-pyridine) in the low-spin (LS) and high-spin (HS) states, which extends our previous work on aqueous [Fe(bpy)3]2+ (bpy = 2,2'-bipyridine) [L. M. Lawson Daku and A. Read More

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December 2018

Mesoscopic simulation study on the structural transition of comb-shaped block copolymer lamellae on chemically patterned substrates: from vertical to lateral.

Phys Chem Chem Phys 2018 Dec 12. Epub 2018 Dec 12.

School of Chemistry and Chemical Engineering, Sichuan University of Arts and Science, Dazhou, Sichuan 635000, P. R. China.

Directed self-assembly of polymers on chemically homogeneous and heterogeneous patterns is of considerable interest for nanolithography and nanofluidic devices. By employing dissipative particle dynamics (DPD) technology, we explore the nanoscale phase separation of comb-like block copolymers (CBCPs) confined at chemically homogeneous and heterogeneous substrates. Herein, the geometric and energetic influences of striped substrates on the microphases are firstly studied using various geometries of annular stripes for the heterogeneous substrates. Read More

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December 2018

Chiral iminophosphorane catalyzed asymmetric sulfenylation of 4-substituted pyrazolones.

Chem Commun (Camb) 2018 Dec 12. Epub 2018 Dec 12.

Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, The Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.

An excellent level of enantioselectivity in asymmetric sulfenylation of 4-substituted pyrazolones was achieved with chiral iminophosphorane as the organocatalyst under continuum solvation conditions (up to 99% ee). Importantly, this catalytic process features high efficiency with excellent enantioselectivities, easy separation of products, low catalytic loadings and scale-up to grams without loss of enantioselectivity. Read More

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December 2018

Induction of apoptosis in MDA-MB-231 breast cancer cells by a PARP1-targeting PROTAC small molecule.

Chem Commun (Camb) 2018 Dec 12. Epub 2018 Dec 12.

MOE Key Laboratory of Protein Sciences, School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, P. R. China.

Poly (ADP-ribose) polymerase-1 (PARP1) is a major member of the PARP superfamily that is involved in DNA damage signalling and other important cellular processes. Here we report the development of a small molecule targeting PARP1 based on the PROTAC strategy. In the MDA-MB-231 cell line, the representative compound 3 can induce significant PARP1 cleavage and programmed cell death. Read More

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December 2018

Enterococci as a key parameter for water quality index: Purires River, Costa Rica.

J Water Health 2018 Dec;16(6):1007-1017

Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, 2060, San José, Costa Rica E-mail:

This study used the Canadian Water Quality Index (CWI) to characterize water sampled at three points within the Purires River micro basin, Costa Rica. The first sampling point is located in a high zone with domestic agricultural activities, the second point around the mid-point of the flow of the river, and the third point at the lowest zone with extensive agricultural activities mainly centered on the production of fresh vegetables. Eleven physicochemical parameters (As, Cd, Cr, biochemical oxygen demand (BOD), chemical oxygen demand (COD), NH, NO, Pb, pH, percent saturation of dissolved oxygen (PSO), and total suspended solids (TSS)) and two microbiological parameters (fecal coliforms and enterococci) were evaluated. Read More

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December 2018

Learning to Air-Breathe: The First Steps.

Physiology (Bethesda) 2019 Jan;34(1):14-29

Section for Zoophysiology, Department of Bioscience, Aarhus University , Aarhus , Denmark.

Air-breathing in vertebrates has evolved many times among the bony fish while in water. Its appearance has had a fundamental impact on the regulation of ventilation and acid-base status. We review the physico-chemical constraints imposed by water and air, place the extant air-breathing fish into this framework, and show how that the advantages of combining control of ventilation and acid-base status are only available to the most obligate of air-breathing fish, thus highlighting promising avenues for research. Read More

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January 2019

Visible-Light-Promoted Transition-Metal-Free Phosphinylation of Heteroaryl Halides in the Presence of Potassium tert-Butoxide.

Org Lett 2018 Dec 12. Epub 2018 Dec 12.

State Key Laboratory of Synthetic Chemistry, and Department of Chemistry , The University of Hong Kong , Pokfulam Road, Hong Kong , China.

A novel visible-light-promoted C-P bond formation reaction in the absence of both transition metal and photoredox catalysts is disclosed. By employing easily available and inexpensive heteroaryl chlorides/bromides as substrates, a variety of heteroaryl phosphine oxides were obtained in moderate to good yields. This strategy provides a simple and efficient route to heteroaryl phosphine oxides. Read More

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December 2018

The London - van der Waals Force Field of a Chemically Patterned Surface to Enable Selective Adhesion.

Langmuir 2018 Dec 12. Epub 2018 Dec 12.

The London - van der Waals (L-vdW) force between a particle and a surface strongly depends on the topography and the chemical properties of the interacting surfaces. While a great deal of work has been done to understand the effect of topographical heterogeneity on the L-vdW adhesion, the role of chemical heterogeneity has been discussed only rarely. This study makes an attempt to quantify the magnitude and range of the L-vdW force acting on a spherical particle in the vicinity of a chemically patterned surface. Read More

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December 2018

Lanthanide-Based Coordination Polymers With 1,4-Carboxyphenylboronic Ligand: Multiemissive Compounds for Multisensitive Luminescent Thermometric Probes.

Inorg Chem 2018 Dec 12. Epub 2018 Dec 12.

Univ Rennes, INSA Rennes, CNRS, UMR 6226 "Institut des Sciences Chimiques de Rennes" , F-35000 Rennes , France.

Reactions in water of lanthanide chlorides with the sodium salt of 1,4-carboxyphenylboronic acid lead to two series of isostructural compounds with respective general chemical formulas [Ln(cpb)(HO)] for Ln = La or Ce and [Ln(cpbOH)(HO)·(cpb)] for Ln = Pr-Lu (except Pm) plus Y. Heterolanthanide coordination polymers that are isostructural to the second series have been synthesized, and their photophysical properties have been studied. This study evidences that it is possible to design multiemissive lanthanide-based coordination polymers that could find their application as multigauge luminescent thermometric probes. Read More

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December 2018

Ultra-Small Abundant Metal-Based Clusters as Oxygen-Evolving Catalysts.

J Am Chem Soc 2018 Dec 12. Epub 2018 Dec 12.

The oxygen evolution reaction is a crucial step in water electrolysis to develop clean and renewable energy. Although noble metal-based catalysts have demonstrated high activity for oxygen evolution reaction, their application have been limited by their high costs and low availability. Here we report the use of a molecule-to-cluster strategy to prepare ultra-small trimetallic clusters by using polyoxometalate molecule as precursors. Read More

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December 2018

Supramolecular Design of Donor-Acceptor Complexes via Heteroatom Replacement towards Structure and Electrical Transporting Property Tailoring.

ACS Appl Mater Interfaces 2018 Dec 12. Epub 2018 Dec 12.

A feasible strategy relies on using nitrogen atoms substitution which is namely chemical modification using standard modification to the original component. Here we present a design concept for donor-acceptor compounds, which involves introducing nitrogen atoms to the middle ring of donor molecules to promote short contacts and reduce steric effect of the supramolecular framework. These nitrogen atom doped complexes are able to cause shorter molecular distance besides the mixed stacking pathway, enlarged π-π interactions or even a scarce 1:2. Read More

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December 2018

A Novel Near-infrared Hyperspectral Absorption/Scattering Imaging Method using Multiple Ground Plates for Evaluating Polymer Composites.

Anal Chem 2018 Dec 12. Epub 2018 Dec 12.

This paper proposes a nondestructive method of evaluating polymer composites using near-infrared (NIR) diffuse reflection spectroscopy with multiple ground plates. Wavelength-dependent absorption and reduced scattering coefficients were acquired to evaluate the chemical structure and the concentration of the substances from absorption and to determine the size and the dispersity of filler in the polymer domain from scattering. NIR spectra of the sample were measured on multiple ground plates, namely, "ground-plate-dependent" diffuse reflection spectra. Read More

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December 2018

Development and evaluation of a combined bioenergetics and organic chemical mass-balance bioaccumulation model for fish.

Environ Sci Technol 2018 Dec 12. Epub 2018 Dec 12.

This study describes the development and evaluation of a new bioenergetically-balanced bioaccumulation (3B) model for organic chemicals in fish. The 3B model is developed from a large database of routine metabolic (oxygen consumption) rates comprising a range of species, body mass and temperature. The chemical uptake and elimination rates of the 3B model are compared against those from three existing bioaccumulation models. Read More

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December 2018
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