The mutagen and probable human carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) is metabolized in the colon to 9-hydroxyl-2,7-dimethyl-7,9,10,11-tetrahydropyrimido[2',1':2,3]imidazo[4,5-f]quinoxaline (MeIQx-M1) by conjugation with microbially generated acrolein. However, whether this microbiota-controlled process alters systemic exposure and hepatotoxicity of MeIQx remains unclear. The physiological relevance of this microbial transformation on the systemic exposure of MeIQx was investigated using an in vitro-in vivo extrapolation approach.
View Article and Find Full Text PDFDescribed herein is an unprecedented access to BN-polyaromatic compounds from 1,1'-biphenylamines by sequential borane-mediated C(sp )-H borylation and intramolecular N-demethylation. The conveniently in situ generated Piers' borane from a borinic acid reacts with a series of N,N-dimethyl-1,1'-biphenyl-2-amines in the presence of PhSiH to afford six-membered amine-borane adducts bearing a C(sp )-B bond at the C2'-position. These species undergo an intramolecular N-demethylation with a B(C F ) catalyst to provide BN-isosteres of polyaromatics.
View Article and Find Full Text PDFIrritable bowel syndrome (IBS) is at high risk of co-morbid depression and anxiety, which reduces patients' quality of life and increases the burden of health care costs. However, the pathophysiological mechanisms responsible for IBS still remain unknown. This study investigated the effects of resveratrol on stress-related depression, anxiety, intestinal and visceral dysfunction in rat model of IBS.
View Article and Find Full Text PDFThe source of trifluoroacetic acid (TFA) has long been a controversial issue. Fluoropolymer thermolysis is expected to be a potential anthropogenic source except for CFC alternatives. However, its TFA yield and contributions have rarely been reported more recently.
View Article and Find Full Text PDFThe objective of this study was to investigate the effects of different dietary energy levels on serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as gene expression of their associated binding proteins and receptors in yak. Fifteen adult male yaks with BW of 276.1 ± 3.
View Article and Find Full Text PDFStatins, known for their lipid-lowering effects, also have immunomodulatory properties. This study aims to examine whether systematic simvastatin administration could decrease polymorphonuclear neutrophils (PMNs) infiltration into brain tissue, as well as alleviate neuroinflammation in a rat model of intracerebral hemorrhage (ICH). The ICH model was induced in adult male Sprague-Dawley rats by an injection of autologous blood.
View Article and Find Full Text PDFJ Environ Sci (China)
March 2019
Peroxyacyl nitrates (PANs) are important secondary pollutants in ground-level atmosphere. Accurate prediction of atmospheric pollutant concentrations is crucial to guide effective precautions for before and during specific pollution events. In this study, four models based on the back-propagation (BP) artificial neural network (ANN) and multiple linear regression (MLR) methods were used to predict the hourly average PAN concentrations at Peking University, Beijing, in 2014.
View Article and Find Full Text PDFCyclic volatile methyl siloxanes (cVMS) used in personal care products are released to aquatic environments through wastewater effluent. cVMS are persistent, toxic, bioaccumulative, and have potential to cause ecological harm. In this study, the environmental behavior of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) were evaluated in the largest lake of southwest China, Dian Lake.
View Article and Find Full Text PDFNeovascularization and re-endothelialization rely on endothelial progenitor cells (EPCs). However, the recruitment and angiogenic roles of EPCs are subject to regulation through the vascular microenvironment, which remains largely unknown. Platelet‑derived growth factor D (PDGF‑D) is a new member of the PDGF family that binds the PDGFR‑β homodimer.
View Article and Find Full Text PDFBackground: Hepatic arterioportal shunt (A-P shunt) is defined as the direct blood flow established between hepatic artery and portal venous system; it is frequently observed in patients with hepatocellular carcinoma (HCC). Clinically, it is important to diagnose HCC associated A-P shunts, as it may impact the treatment strategy of the patients. In the present study, we described the imaging findings of the HCC associated A-P shunts and discussed the treatments strategy of such patients.
View Article and Find Full Text PDFPeroxyacetyl nitrate (PAN) are effective indicators of photochemical pollution, and also play an important role in regional oxidant balance. Surprisingly, in recent years, PAN have also been detected under conditions that do not favor the photochemical processes. To obtain a better understanding of the mechanisms of formation of atmospheric compound pollution, this study examined the relationships between concentrations of PAN and other pollutants (e.
View Article and Find Full Text PDFPurpose: To examine the clinical significance of an autoantibody (AAb) against a novel tumor-associated antigen (TAA) derived from human DNA-topoisomerase I, termed as TOPO48 AAb, and peripheral blood survivin-expressing circulating cells (CCC) in patients with early stage endometrial cancer (EC).
Methods: Blood samples were collected from 80 patients with early stage EC and 80 age-matched healthy subjects. Plasma levels of the TOPO48 AAb were measured with a specific antibody capture enzyme-linked immunosorbent assay (ELISA) and blood survivin-expressing CCC assessed with a reverse transcription-polymerase chain reaction products based on a hybridization-enzyme-linked immunosorbent assay (RT-PCR-ELISA).
Ovarian hormones reportedly have beneficial effects on affective behaviors. However, the functions of ovarian hormones in neurotransmitter signaling must be identified to understand their role in anxiety and depression. Several studies have provided evidence of the relationship between ovarian hormones and the dopaminergic system, but the interaction between ovarian hormones and dopamine D3 receptor (DRD3) is poorly understood.
View Article and Find Full Text PDFDescribed herein is the development of an unprecedented route to bridged sila- N-heterocycles via B(CF)-catalyzed cascade silylation of N-aryl piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) β-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp C-H silylation.
View Article and Find Full Text PDFJ Stroke Cerebrovasc Dis
December 2018
Our previous studies have demonstrated that hemorrhage-derived iron has a key role in causing brain injury after intraventricular hemorrhage (IVH). Based on this finding, we hypothesized that edaravone, a free-radical scavenger, has the potential to alleviate hydrocephalus and neurological deficits post-IVH by suppressing iron-induced oxidative stress. Thus, this study aimed to investigate the efficacy of edaravone for rats with FeCl injection, as well as to explore the related molecular mechanism.
View Article and Find Full Text PDFHepatobiliary Pancreat Dis Int
October 2018
Background: Interleukin-37b (IL-37b), a vital negative regulator of the innate immune system, has been reported to be a tumor inhibitor in different type of cancers. However, little is known about the relationship between IL-37b and hepatocellular carcinoma (HCC). The present study aimed to investigate the potential roles of IL-37b in HCC progression.
View Article and Find Full Text PDFThe ozone layer depletion and its recovery, as well as the climate influence of ozone-depleting substances (ODSs) and their substitutes that influence climate, are of interest to both the scientific community and the public. Here we report on the emissions of ODSs and their substitute from China, which is currently the largest consumer (and emitter) of these substances. We provide, for the first time, comprehensive information on ODSs and replacement hydrofluorocarbon (HFC) emissions in China starting from 1980 based on reported production and usage.
View Article and Find Full Text PDFThe fiber vector eigenmode based mode division multiplexing (VMDM) transmission over few-mode fiber (FMF) with the 1st-order cylinder vector beams (CVBs) has been demonstrated. The performances of generated CVB using q-plate (QP) have been characterized before and after transmission over the FMF respectively based on the high-order Poincaré sphere model and polarization grating (PG). The measured minimum mode isolations between the two CVBs (TM and TE modes) of the used 4-mode FMF are about 16.
View Article and Find Full Text PDFMono-dispersed polystyrene-based microspheres with diameters about 1 μm encapsulating rhodamine moieties as oxygen insensitive internal reference probes and platinum octaethylporphyrin units as oxygen sensitive probes were synthesized as new ratiometric oxygen sensors (Rhod-PtOEP-PS). The dual luminophors of rhodamines and platinum porphyrin moieties exhibited emissions maxima at 585 nm and 644 nm, respectively. The microspheres showed good oxygen sensing properties in different oxygen partial pressures (pO) and dissolved oxygen (DO) concentrations.
View Article and Find Full Text PDFFood Addit Contam Part A Chem Anal Control Expo Risk Assess
October 2018
Short-chain chlorinated paraffins (SCCPs) have drawn increasing interest worldwide since they were included in the list of controlled persistent organic pollutants in Annex A of the Stockholm Convention in 2017, and the potential health risk they pose to humans must be evaluated. In this study, 86 human milk samples were collected from 55 healthy Chinese mothers living in the Shijiazhuang region of Northern China in 2014-2015. Advanced online gel permeation chromatography-gas-chromatography-coupled mass spectrometry with negative-ion chemical ionisation was used to quantify the SCCPs in the samples.
View Article and Find Full Text PDFOne challenge in studying high-temperature superconductivity (HTSC) stems from a lack of direct experimental evidence linking lattice inhomogeneity and superconductivity. Here, we apply synchrotron hard X-ray nanoimaging and small-angle scattering to reveal a novel micron-scaled ribbon phase in optimally doped BiSrCaCuO (Bi-2212, with δ = 0.1).
View Article and Find Full Text PDFWe report the first diarylborane-catalysed hydrosilylation of epoxides and cyclic ethers. Mechanistic studies on the in situ generated Piers' borane (C6F5)2BH with hydrosilanes in the presence of an epoxide revealed that an alkyloxy(diaryl)borane (C6F5)2BOR is readily formed as a catalytically competent species for the outer-sphere hydrosilylation of epoxides and cyclic ethers.
View Article and Find Full Text PDFSeleno-short-chain chitosan (SSCC) was a synthesized chitosan derivative with the molecular weight of 4826.986 Da. The study is aimed to investigate cytotoxicity of SSCC on human breast cancer MCF-7 and BT-20 cells and explore apoptosis-related mechanism in vitro.
View Article and Find Full Text PDFFundamental questions concerning the reaction interface in Li-O batteries, including where reactions occur and discharge-charge asymmetries come from, have stimulated a flurry of investigations; nevertheless, heated debates still prevail. Dynamic electrochemical impedance spectroscopy (EIS) is employed here to probe the reaction interface in a Li-O battery under potentiostatic and galvanostatic modes. Two impedance semicircles are identified during discharge with the high- and the low-frequency ones related to the LiO film and the oxygen reduction reaction (ORR), respectively.
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