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Abstract: The electronic structures and optical properties of heavily boron (B)-doped zinc blende silicon carbide (β-SiC) have been investigated using the plane-wave pseudo-potential method with the generalized gradient approximation (GGA) based on density functional theory. The doped models Si n BC n−1 (n=4, 32) have been constructed by β-SiC unit cell. The calculated results show that the band gap of β-SiC transforms from indirect band gap to direct band gap with band gap shrink after carbon atom is replaced by boron atom. The dielectric constant of heavily B-doped β-SiC in low frequency is found to be remarkably larger, so it may act as a new dielectric material. Furthermore, after B doping, absorption peaks appear in the ultra-violet band (5–20eV) and infrared band (0–2eV). The ultra-violet absorption is similar to the undoped β-SiC. The infrared absorption would intensify with the increase of doping concentration, and absorption edge emerges redshift. [Copyright &y& Elsevier]

Objectives: The objectives of this study were to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization in livestock and related workers in four Chinese provinces and the characteristics of these isolates. [ABSTRACT FROM PUBLISHER]

Agricultural products are frequently contaminated by mycotoxins; thus, the accurate detection of mycotoxins is important to food safety. Zearalenone (ZEN), a mycotoxin produced by certain Fusarium and Gibberella species, is a group III carcinogen. We developed a universal surface-enhanced Raman scattering (SERS) aptasensor for the detection of ZEN. The SERS biosensor consists of two functional nanomaterials: sulfhydryl (SH)-ZEN aptamer complementary DNA-modified Fe 3 O 4 @Au was used as a capture probe and SH-ZEN aptamer-modified Au@Ag core-shell nanoparticles served as reporter probes. In the absence of ZEN, the highest Raman signal was obtained owing to the SERS effects of Fe 3 O 4 @Au and Au@Ag core-shell nanoparticles. Conversely, the addition of ZEN triggered the release of Au@Ag core-shell nanoparticles from Fe 3 O 4 @Au, leading to a decrease in SERS intensity after magnetic separation. Hybridization of the ZEN aptamer and its complementary strand generated a strong SERS signal from the reporter probe. Moreover, preferential binding of the ZEN aptamer to ZEN was observed. The signal intensity in SERS decreased linearly when the capture probes released the reporter. For ZEN detection, a linear range from 0.005 to 500 ng mL−1, with an R2 of 0.9981, was obtained. The detection limit was 0.001 ng mL−1. The SERS aptasensor showed excellent performance for analytical applications with real-world samples (beer and wine). This study presents a new model for the detection of mycotoxins based on simple changes in aptamers. [Display omitted] • Detection of mycotoxins is important to overcome food contamination. • SERS aptasensor was developed to detect zearalenone, a group III carcinogen. • SH-cDNA-modified Fe 3 O 4 @Au as capture probe; SH-Apt-modified Au@Ag as reporter probe. • Wide linear range of 0.005–500 ng mL−1 for detecting zearalenone. • Novel model for the detection of mycotoxins to guarantee food safety. [ABSTRACT FROM AUTHOR]

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) is the main cause of arteriosclerosis obliterans (ASO). The present study aimed to investigate the role of microRNA (miR)-125b on the proliferation and migration of VSMCs. Platelet-derived growth factor-BB (PDGF-BB; 20 ng/ml) was used to treat VSMCs to establish an in vitro model of ASO. VSMCs were transfected with miR-125b mimic to overexpress miR-125. Cell Counting kit-8 (CCK-8) and BrdU assays were performed to assess the proliferative ability of VSMCs, while Transwell and wound healing assays were performed to assess the migratory ability of VSMCs. Western blot and immunofluorescence analyses were performed to detect the expression levels of angio-associated migratory cell protein (AAMP) and serum response factor (SRF) in VSMCs following transfection with miR-125b mimic or inhibitor. The results demonstrated that miR-125b expression decreased following treatment with PDGF-BB, the effects of which were reversed following transfection with miR-125b mimic. According to the CCK-8 assay, the cell proliferative ability decreased by ~50% compared with the negative control (NC) group, and ~40% at day 4 based on the BrdU assay. The results of the Transwell and wound healing assays indicated that the migratory ability of VSMCs significantly decreased in the miR-125b mimic group compared with the NC group. Furthermore, western blot and immunofluorescence analyses demonstrated that AAMP and SRF expression levels decreased following transfection with miR-125b mimic compared with the NC group, the effects of which were reversed following transfection with miR-125 inhibitor. Taken together, the results of the present study suggested that miR-125b inhibits the proliferative and migratory abilities of VSMCs by regulating the expression levels of AAMP and SRF. [ABSTRACT FROM AUTHOR]

Abstract: The photochromic process of nanocomposite film containing nanometer-sized Keggin type phosphotungstic acid uniformly dispersed in polyacrylamide matrix was studied by in situ AFM and spectroscopy. Under UV irradiation, the film was reduced photochemically to yield blue species. With the increase of irradiation time, the photoreduction proceeded from one-electron to two-electron blue stage. During the photochromism, the size and morphology of composite particles changed due to the cross-linked reactions of polymeric radicals. The XPS studies indicated that the chemical environment of tungsten changed and the W5+/W ratio increased as irradiation time prolonged. FT-IR results showed that the Keggin geometry of phosphotungstic acid was still preserved inside the composite during photochromism, and the interactions between polyanions and polymer matrix increased with the irradiation time. It was suggested that the degree of the photoreduction process depended on the varying of interactions between phosphotungstic acid and polymer. [Copyright &y& Elsevier]

A kind of chiral azobenzene amphiphile, N-[4-(4-dodecyloxyphenylazo)benzoyl]-l-glutamic acid (C12-Azo-l-Glu; as shown in Fig. 1), was synthesized and the self-organization properties on solid substrates were investigated. C12-Azo-l-Glu underwent a reversible trans–cis photoisomerization in dilute solution. While the photoisomerization was suppressed on solid substrate because of the H-aggregation, indicating the formation of compact film. When C12-Azo-l-Glu was cast from ethanol solution onto the hydrophilic surface of mica, a stable flat-layered structure formed spontaneously in large scale. High-resolution images allowed the identification of the relative orientation of molecular rows in the ordered thin film and the crystal lattice of mica. A molecular packing model of the layered structure was proposed. There was a template effect of mica to the self-organization process. Hydrogen bonding, π–π interaction and the chiral center in the molecule played the important roles in the self-organization process. The cooperative competitive effect between them led to the highly ordered structure. [Copyright &y& Elsevier]

A series of photochromic hybrid films were prepared through entrapping tungsten heteropolyoxometallate (PW12O403−) and molybdenum heteropolyoxometallate (PMo12O403−) in polyacrylamide (PAM) matrix, the corresponding structure and photochromic behaviors of the films were investigated with Fourier transform infrared (FT-IR), UV–Vis–near-infrared (NIR) absorption spectra (UV–Vis–NIR) and electron spin resonance (ESR). FT-IR results showed that the Keggin geometry of heteropolyoxometallate was still preserved inside the composites and strong Coulombic interaction was built between heteropolyoxometallate and PAM via hydrogen bonding. Irradiated with ultraviolet light, the transparent films changed from colorless to blue and showed reversible photochromism. The bleaching process occurred when the films were in contact with air or O2 in the dark. The molybdenum heteropolyoxometallate hybrid film had higher photochromic efficiency and slower bleaching reaction than tungsten heteropolyoxometallate hybrid film. The characteristic signals of radical and W(V) or Mo(V) in ESR spectra indicated that PAM is a hydrogen donor and the photoreduced process is in accordance with the radical mechanism. [Copyright &y& Elsevier]

Novel photochromic nanocomposite thin film containing phosphotungstic acid entrapped in polyacrylamide was prepared using ultrasound technique. TEM image revealed that the polyoxometalates nanoparticles with narrow size distribution were finely dispersed in polymer matrix. IR spectra showed that the Keggin geometry of polyoxometalates was still preserved inside the composite film and strong Coulombic interaction was built between heteropolyoxometalates and polyacrylamide via hydrogen bond. It was found that the thermal stability of the hybrid film was lower than that of pure polymer but the film was stable enough for photochromic application from the TG–DTA curves. The transparent film changed from colorless to blue under UV irradiation and showed reversible photochromism. The bleaching process occurred when the film was in contact with air or O2 in the dark. The photoreduced process was in accordance with radical mechanism. [Copyright &y& Elsevier]

A new photochromic film was prepared based on the Keggin type H3PW12O40 (PW12) with polyacrylamide (PAM) matrix. The microstructure, photochromic behavior and mechanism were investigated with FT-Infrared spectroscopy (FT-IR), atomic force microscopy (AFM), transmission electron microscopy (TEM), ultraviolet–visible absorption spectroscopy (UV–VIS), and electron resonance spectroscopy (ESR). FT-IR results showed that the Keggin geometry of PW12 was still preserved inside the matrix, and a charge-transfer bridge was built between PW12 and PAM via hydrogen bond. AFM images indicated that the surface topography of the polymer matrix changed after adding PW12. In the hybrid films, the PW12 particles had regular microstucture in nanoscale shown in TEM image. Under UV irradiation, the film was reduced photochemically to yield a blue species. With the increase of irradiation time, the photoreduction proceeded from one-electron to two-electron blue stage. The characteristic signals of W (V) and radical in ESR spectra indicated that the photoreduced process was in accordance with the radical mechanism. [Copyright &y& Elsevier]

Four new D-π-A type N,O -chelated BF 2 complexes (TCBOB , TCBTB , TCQB and TCPB) were synthesized. It was found that TCPB bearing the ligand of N -(1-pyridinyl)benzoamide shows gelation ability in methylcyclohexane, DCM/peteroleum ether, etc. The time-dependent UV–vis absorption and fluorescent emission spectral changes during the gel formation revealed that π-π interactions play important roles in the self-assembling processes. Particularly, the emission of the xerogel-based film of TCPB can be quenched by TFA (trifluoroacetic acid) vapor, and it showed high performance in the detection of TFA compared with the spin-coating films of TCBOB , TCBTB and TCQB. In addition, the BF 2 complexes exhibited reversible mechanofluorochromic behavior under the treatment of grinding/fuming or heating, and TCPB gave high-contrast mechanofluorochromism compared with others. XRD patterns in different solid states demonstrated that the external mechanical forces can induce the transformation from the crystalline to the amorphous states. Powder of TCPB was also used to image latent fingerprints on surface of glasses, and distinct fluorescent images were obtained. [Display omitted] • New BF 2 complexes were synthesized. • Gelation abilities and MFC properties of them were studied. • They were first used to detect LFP. [ABSTRACT FROM AUTHOR]

"Smart" polymeric microcapsules with excellent permeability of membranes have drawn considerable attention in scientific and industrial research such as drug delivery carriers, microreactors, and artificial organelles. In this work, hybrid hollow polymeric microcapsules (HPs) containing redox-active gold-sulfide bond were prepared with bovine serum albumin, inorganic metal cluster (AuNCs), and poly(N-isopropylacrylamide) conjugates by using Pickering emulsion method. HPs were transferred from water-in-oil to water-in-water by adding PEGbis(N-succinimidylsuccinate). To achieve redox-responsive membrane, the Au-S bond units incorporated into the microcapsules' membranes, allowed us to explore the effects of a new stimuli, that is, the redox Au-S bond breaking on the microcapsules' membranes. The permeability of these hybrid hollow polymeric microcapsules could be sensitively tuned via adding environment-friendly hydrogen peroxide (H2O2), resulting from a fast fracture of Au-S bond. Meanwhile, AuNCs and conjugates could depart from the microcapsules, and enhance the permeability of the membrane. Based on the excellent permeability of the membrane, phosphatase was encapsuled into HPs and p-nitrophenyl phosphate as a substrate. After adding 1 × 10−2 and 1 × 10−4 M H2O2, the catalytic efficiency was nearly 4.06 and 2.22 times higher than that of HPs in the absence of H2O2, respectively. Hence, the unique redox-responsive HPs have potential applications in biocatalytic reaction, drug delivery, and materials as well as in bioscience. [ABSTRACT FROM AUTHOR]

To explore the possibility of predicting the clinical types of Corona-Virus-Disease-2019 (COVID-19) pneumonia by analyzing the non-focus area of the lung in the first chest CT image of patients with COVID-19 by using automatic machine learning (Auto-ML). 136 moderate and 83 severe patients were selected from the patients with COVID-19 pneumonia. The clinical and laboratory data were collected for statistical analysis. The texture features of the Non-focus area of the first chest CT of patients with COVID-19 pneumonia were extracted, and then the classification model of the first chest CT of COVID-19 pneumonia was constructed by using these texture features based on the Auto-ML method of radiomics, The area under curve(AUC), true positive rate(TPR), true negative rate (TNR), positive predictive value(PPV) and negative predictive value (NPV) of the operating characteristic curve (ROC) were used to evaluate the accuracy of the first chest CT image classification model in patients with COVID-19 pneumonia. The TPR, TNR, PPV, NPV and AUC of the training cohort and test cohort of the moderate group and the control group, the severe group and the control group, the moderate group and the severe group were all greater than 95% and 0.95 respectively. The non-focus area of the first CT image of COVID-19 pneumonia has obvious difference in different clinical types. The AUTO-ML classification model of Radiomics based on this difference can be used to predict the clinical types of COVID-19 pneumonia. [ABSTRACT FROM AUTHOR]

A hydrogen bonded complex could self-assemble into one-dimensional fibers in its gel phase. The fibrous film could be used as a sensor to detect and discriminate aromatic and aliphatic amines. [ABSTRACT FROM AUTHOR]

We characterized 44 Salmonella enterica serotype Typhimurium isolates from Tongji Hospital outpatients in Wuhan, China, May 2002-October 2005. All 31 ciprofloxacin-resistant isolates were also resistant to >8 other antimicrobial drugs and carried >2 mutations in GyrA and 1 mutation in ParC. Class 1 integrons were identified in 37 isolates. [ABSTRACT FROM AUTHOR]

The P2Y 14 receptor (P2Y 14 R) plays a key role in the modulation of inflammatory process, but very few classes of antagonists have been reported. A series of 3-amide benzoic acid derivatives were identified as novel and potent P2Y 14 R antagonists. The most potent antagonist, 16c , showed comparable activity (IC 50 = 1.77 nM) to PPTN, the most potent P2Y 14 R antagonist reported. Compound 16c demonstrated dramatically improved aqueous solubility and excellent metabolic stability in rat and human microsomes. Investigation of the anti-inflammatory effect of 16c was performed in MSU treated THP-1 cells by flow cytometry, Western Blot and immunofluorescence labeling technology, which exhibited that 16c might be a promising candidate for further research. Image 1 • A series of 3-amide benzoic acids was identified as novel P2Y 14 R antagonists. • Compound 16c showed potent anti-inflammatory effect. • Compound 16c demonstrated dramatically improved aqueous solubility and excellent metabolic stability. [ABSTRACT FROM AUTHOR]

Metformin or glucagon-like peptide-1 (GLP-1) analogue liraglutide has cardiovascular benefits. However, it is not clear whether their combined treatment have additive or synergistic effects on the vasculature. In this study, human umbilical vein endothelial cells (HUVECs), exposed to palmitic acid (PA) to induce endothelial dysfunction, were incubated with metformin, liraglutide or their combination. High fat diet (HFD)-fed ApoE−/− mice were randomized into control, metformin, liraglutide, and combination treatment groups. Results showed that in PA-treated HUVECs and HFD-fed ApoE−/− mice, combination of metformin and liraglutide at lower dose significantly improved endothelial dysfunction compared with the single treatment. Metformin upregulated GLP-1 receptor (GLP-1R) level and protein kinase A (PKA) phosphorylation. However, PKA inhibition but not GLP-1R blockade eliminated the protective effects of metformin on endothelial function. Furthermore, AMPK inhibitor compound C abolished the metformin-mediated upregulation of GLP-1R level and PKA phosphorylation. In conclusion, combination of metformin and liraglutide has synergistic protective effects on endothelial function. Moreover, metformin stimulates GLP-1R and PKA signalling via AMPK-dependent pathway, which may account for its synergistic protective effects with liraglutide. Our findings provide new insights on the interaction between metformin and GLP-1, and provide important information for designing new GLP-1-based therapy strategies in treating type 2 diabetes. [ABSTRACT FROM AUTHOR]

Neutrophils contribute to innate host immunity by functioning as professional phagocytes, whereas dendritic cells (DCs) are prototypic antigen presenting cells (APCs) responsible for the induction of adaptive immune responses. We have demonstrated recently that neutrophils trans-differentiate into a unique population, termed “neutrophil-DC hybrids,” expressing surface markers of both neutrophils and DCs and exhibiting dual functionality of both phagocytes and APCs. Although the hybrid cells emerged in significant numbers in murine bone marrow (BM) culture in the presence of GM-CSF, mechanisms regulating their development remained mostly unknown. In this study, we tested a total of 61 cytokines for their potentials to regulate neutrophil-DC hybrid formation using a newly developed BM micro-culture system combined with semi-automated FACS analysis. Several cytokines including GM-CSF were found to promote the generation of neutrophil-DC hybrids defined by the phenotype of CD11c+/MHC II+/Ly6G+. When tested in the presence of GM-CSF, hybrid cell development was enhanced by IL-4 and suppressed by interferon-γ (IFNγ) in dose-dependent fashions. We next determined in vivo impacts of IL-4 and IFNγ on the development of neutrophil-DC hybrids in thioglycollate-induced peritonitis lesions. Intraperitoneal administrations of IL-4/anti-IL-4 antibody complex (IL-4C) significantly increased the number of hybrids recovered from the lesions. By contract, recovery of hybrids was reduced by recombinant IFNγ. With regard to function, those hybrid cells recovered from IL-4C-treated mice and IFNγ-treated mice showed potent abilities to capture E.coli. These observations imply that emergence of neutrophil-DC hybrids in inflammatory sites is tightly regulated by local cytokine milieus. [ABSTRACT FROM AUTHOR]