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This work presents a novel process to form SiNx films and process for membranes with excellent mechanical properties for micro-electro-mechanical systems application as well as integration as IR waveguide for photonic application. The SiNx films were fabricated in SiNgen apparatus which is a single wafer chamber equipment compared to conventional low pressure chemical vapor deposition furnace process. The films showed low stress, good mechanical properties, but the synthesis also eradicates the issues of particle contamination. Through optimizing of the growth parameters and post annealing profile, low stress (40 Mpa) SiNx film could be finally deposited when annealing temperature rose up to 1150 °C. The stress relaxation is a result of more Si nano-crystalline which was formed during annealing, according to the FTIR results. The mechanical properties, Young's modulus and hardness, were 210 Gpa and 20 Gpa respectively. For the waveguide application, a stack of three layers, SiO2/SiNx/SiO2 was formed where the optimized layer thicknesses were used for minimum optical loss according to simulation feedback. After deposition of the first two layers in the stack, the samples were annealed in range of 900–1150 °C in order to release the stress. Chemical mechanical polish technique was applied to planarize the nitride layer prior to the oxide cladding layer. Such wafers can be used to bond to Si or Ge to manufacture advanced substrates. [ABSTRACT FROM AUTHOR]

Optical fiber pre-warning system (OFPS) is often used to monitor the occurrence of disasters such as the leakage of oil and natural gas pipeline. It analyzes the collected vibration signals to judge whether there is any harmful intrusion (HI) events. At present, the research in this field is mainly focused on the constant false alarm rate (CFAR) methods and derivative algorithms to detect intrusion signals. However, the performance of CFAR is often limited to the actual collected signals distribution. It is found that the background noise usually obeys non-independent and identically distribution (Non-IID) through the statistical analysis of acquisition signals. In view of the actual signal distribution characteristics, this paper presents a CFAR detection method based on the normalization processing for background noise. A high-pass filter is designed for the actual Non-IID background noise data to obtain the characterization characteristic. Then, the background noise is converted to independent and identically distribution (IID) by using the data characteristic. Next, the collected data after normalization is processed with efficient cell average constant false alarm rate (CA-CFAR) method for detection. Finally, the results of experiments both show that the intrusion signals can be effectively detected, and the effectiveness of the algorithm is verified. [ABSTRACT FROM AUTHOR]

This study probe the probable impacts of coal mining pollution and its impacts on human’s health and environment. A total of 144 samples including coal and coal wastes, soil, plants, foods, and water were collected from the Hancheng county and countryside of Shaanxi, China. All the samples were analyzed for trace elements using ICP-MS, OES, and AFS. Results showed that the concentration of Se, As, Cr, Cu, Pb, Cd, Co, Ni, Mo, U, Th (mgKg−1), Fe, Mn, Al, Ti (%) etc., in coal and coal wastes were 7.5, 12.1, 275, 55, 54.2, 0.8, 14.8, 94.5, 8.9, 4.9, 17.2, 3.5, 0.02, 19, 0.7, respectively. While in soil 0.6, 12, 194, 27.5, 7.4, 0.6, 11.3, 83.4, 0.7, 1.7, 9.9, 3.1, 0.04, 10.5, and 0.4 for the above elements, respectively. In Hancheng foods, the average concentration of Se-0.09, As-0.15, Cr-1.8, Cu-3.2, Pb-0.4, Cd-0.02, Co-0.09, Ni-0.4, Mo-0.64, U-0.01, Th-0.03, Fe-129, Mn-15.6, Al-234, and Ti-5.2 in mgKg−1, respectively, which are comparably higher than the countryside. The elemental concentration in groundwater of both areas was below the WHO-2004 standard. In Hancheng, the average daily intake (mgKg−1bw/d) of Se 0.004-0.0038, As 0.004-0.13, Cr 0.055-0.06, Cd 0.001-0.004, Ni 0.018-13.91, Pb 0.05-0.001 adult-children, respectively. The toxic trace elements such as Cr, Cu, Mn, Pb, Ti, Cd, Co, Th, Fe, Al, and Mo caused non-carcinogenic risk with high morbidity in children than adults. By assessing environmental risks, coal and coal wastes caused high risk, food and plants faced moderate to high risk, while mountain and agriculture soil are prone to low to considerable risk. The pollution in Hancheng County is extreme as compared to the countryside. The study concluded that the contamination is geogenic in both the areas but coal mining enhance the metals contamination and has extensive impacts on the living community and environment of Hancheng areas. [ABSTRACT FROM AUTHOR]

The kinetics and Fenton-like mechanism are two challenging tasks for heterogeneous Fenton-like catalytic oxidation of organic pollutants. In this study, three kinetic models were used for the kinetic studies of Fe3O4/MWCNTs-H2O2 Fenton-like reaction for MO degradation. The results indicated that this reaction followed the firstorder kinetic model. The relationship of reaction rate constant and temperature followed the Arrhenius equation. The activation energy and frequency factor of this system were calculated as 8.2 kJ.mol-1 and 2.72 s-1, respectively. The quantifications of Fe ions dissolution and .OH radicals generation confirmed that the homogeneous and heterogeneous catalyses were involved in Fe3O4/MWCNTs-2O2 Fenton-like reaction. The reaction rate constant was closely related with Fe ions dissolution and .OH radicals generation. Fe3O4/MWCNTs nanocomposites had typical ferromagnetic property and could be easily separated from solution by an external magnet after being used. Furthermore, Fe3O4/MWCNTs nanocomposites exhibited good stability and recyclability. Finally, the Fenton-like mechanisms on homogeneous and heterogeneous catalyses were described. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotubes (MWCNTs) can act not only as a support for Fe3O4 nanoparticles (NPs) but also as a coworker with synergistic effect, accordingly improving the heterogeneous Fenton-like efficiency of Fe3O4 NPs. In this study, Fe3O4 NPs were in situ anchored onto MWCNTs by a moderate co-precipitation method and the as-prepared Fe3O4/MWCNTs nanocomposites were employed as the highly efficient Fenton-like catalysts. The analyses of XRD, FTIR, Raman, FESEM, TEM and HRTEM results indicated the formation of Fe3O4 crystals in Fe3O4/MWCNTs nanocomposites prepared at different conditions and the interaction between Fe3O4 NPs and MWCNTs. Over a wide pH range, the surface of modified MWCNTs possessed negative charges. Based on these results, the possible combination mechanism between Fe3O4 NPs and MWCNTs was discussed and proposed. Moreover, the effects of preparation and catalytic conditions on the Fenton-like catalytic efficiency were investigated in order to gain further insight into the heterogeneous Fenton-like reaction catalyzed by Fe3O4/MWCNTs nanocomposites. [ABSTRACT FROM AUTHOR]

Permanent damage to white matter tracts, comprising axons and myelinating oligodendrocytes, is an important component of brain injuries of the newborn that cause cerebral palsy and cognitive disabilities, as well as multiple sclerosis in adults. However, regulatory factors relevant in human developmental myelin disorders and in myelin regeneration are unclear. We found that AXIN2 was expressed in immature oligodendrocyte progenitor cells (OLPs) in white matter lesions of human newborns with neonatal hypoxic-ischemic and gliotic brain damage, as well as in active multiple sclerosis lesions in adults. Axin2 is a target of Wnt transcriptional activation that negatively feeds back on the pathway, promoting ?-catenin degradation. We found that Axin2 function was essential for normal kinetics of remyelination. The small molecule inhibitor XAV939, which targets the enzymatic activity of tankyrase, acted to stabilize Axin2 levels in OLPs from brain and spinal cord and accelerated their differentiation and myelination after hypoxic and demyelinating injury. Together, these findings indicate that Axin2 is an essential regulator of remyelination and that it might serve as a pharmacological checkpoint in this process. [ABSTRACT FROM AUTHOR]

The molecular basis of CNS myelin regeneration (remyelination) is poorly understood. We generated a comprehensive transcriptional profile of the separate stages of spontaneous remyelination that follow focal demyelination in the rat CNS and found that transcripts that encode the retinoid acid receptor RXR-γ were differentially expressed during remyelination. Cells of the oligodendrocyte lineage expressed RXR-γ in rat tissues that were undergoing remyelination and in active and remyelinated multiple sclerosis lesions. Knockdown of RXR-γ by RNA interference or RXR-specific antagonists severely inhibited oligodendrocyte differentiation in culture. In mice that lacked RXR-γ, adult oligodendrocyte precursor cells efficiently repopulated lesions after demyelination, but showed delayed differentiation into mature oligodendrocytes. Administration of the RXR agonist 9-cis-retinoic acid to demyelinated cerebellar slice cultures and to aged rats after demyelination caused an increase in remyelinated axons. Our results indicate that RXR-γ is a positive regulator of endogenous oligodendrocyte precursor cell differentiation and remyelination and might be a pharmacological target for regenerative therapy in the CNS. [ABSTRACT FROM AUTHOR]

We conducted a genome-wide association study of generalized vitiligo in the Chinese Han population by genotyping 1,117 cases and 1,429 controls. The 34 most promising SNPs were carried forward for replication in samples from individuals of the Chinese Han (5,910 cases and 9,916 controls) and Chinese Uygur (713 cases and 824 controls) populations. We identified two independent association signals within the major histocompatibility complex (MHC) region (rs11966200, Pcombined = 1.48 × 10−48, OR = 1.90; rs9468925, Pcombined = 2.21 × 10−33, OR = 0.74). Further analyses suggested that the strong association at rs11966200 might reflect the reported association of the HLA-A*3001, HLA-B*1302, HLA-C*0602 and HLA-DRB1*0701 alleles and that the association at rs9468925 might represent a previously unknown HLA susceptibility allele. We also identified one previously undescribed risk locus at 6q27 (rs2236313, Pcombined = 9.72 × 10−17, OR = 1.20), which contains three genes: RNASET2, FGFR1OP and CCR6. Our study provides new insights into the genetic basis of vitiligo. [ABSTRACT FROM AUTHOR]

The fabrication of an electrode modified with cadmium selenide/methylene blue{CdSe/MB}n multilayer films is introduced via assembling layer-by-layer CdSe and methylene blue on the glassy carbon electrode surface. The multilayer films have been investigated by scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The electrode exhibited a good stability for the simultaneous determination of guanine and adenine in DNA. The experimental parameters were optimized and the limit of detection (S/N = 3) for guanine and adenine was 0.3 ng·mL−1 and 0.9 ng·mL−1, respectively, under the optimum conditions. A direct electrochemical method for simultaneous determination of guanine and adenine in DNA is presented. [ABSTRACT FROM AUTHOR]

The chemical compositions of volatile oils extracted from Zingiber corallinum Hance were obtained by steam distillation extraction (SDE) and supercritical fluid extraction (SFE) followed by gas chromatography-mass spectrometry analysis. The effects of pressure, temperature, modifier volume, and extraction time on the SFE of Z. corallinum oil were investigated, and optimization of the conditions were: extraction temperature, 30 °C; dynamic extraction time, 40 min; pressure, 10 Mpa; and modifier volume, 50 mL. 29 compounds from SFE extracts were identified. The main components were sabinene (16.19%), terpinen-4-ol (16.26%), β-sesquiphellandrene (3.26%), triquinacene 1, 4-bis (methoxy) (22.01%), triquinacene 1,4,7-tris (methoxy) (3.66%), 1-[4-(1-methyl-2-propenyl) phenyl] ethanone (9.87%) and ferulic acid methyl ester (16.88%) accounting for 88.13% of all compounds. SFE extracts were found to be markedly different from the corresponding SDE extracts. 22 compounds from SDE extracts were identified. The major components, accounting for 92.48% of SDE extracts, were sabinene (53.38%), α-terpinene (3.23%), γ-terpinen (2.16%), terpinen-4-ol (22.66%), β-sesquiphellandrene (1.41%) and triquinacene, 1, 4-bis (methoxy) (9.64%). [ABSTRACT FROM AUTHOR]

Abstract  The hydrothermal synthesis of a heterocyclic quaternary nitrogen compound, namely, 6,7-dihydro-pyrido[2′,1′:3,4]pyrazino[1,2-a]imidazol-5-ium-bromide monohydrate (LBr · H2O) is reported. Various spectroscopic analyses were performed on the cationic heterocycle. CuII and ZnII halide complexes of this novel ligand were prepared. The heterocycle and its complexes were characterized by single crystal X-ray diffraction analysis. Both complexes contain neutral [MIILX3] molecules, where the cyclic ligand (L) is coordinated to the metal as a monodentate ligand. The Cu2 complex has a distorted tetrahedral geometry, indicating an obvious steric effect from L on the chloride co-ligand. [ABSTRACT FROM AUTHOR]

Silica gel-supported Fe(II) (SiOFe) was prepared and used for heterogeneous degradation of sulforhodamine B (SRB) and 2,4-dichlorophenol (DCP) under visible irradiation (′λ > 420 nm) as an effective catalyst. UV-visible spectra, and infrared Spectrophotometry (IR), fluorescence, total organic carbon (TOC) and electron spin resonance (ESR) measurements were employed to analyze the photoreaction products. The results showed that SRB could be efficiently degraded by SiOFe/H2O2 system under visible irradiation with 100% decolorization and 72.3% TOC removal after 180 min illumination. The results of ESR and fluorescence measurements indicated that the oxidative process was predominated mainly by the hydroxyl radical (·OH) generated in the system. [ABSTRACT FROM AUTHOR]

Abstract  Using 1-ethyl-2-methylimidazolium trifluoroacetate (EMImTfa) as the supporting electrolyte, a couple of well-defined and reversible redox peaks of Myb could be observed at the basal plane graphite (BPG) electrode through direct electron transfer between the protein and the BPG electrode, whose anodic and cathodic peak potentials were at −0.098 V and −0.144 V vs. Ag | AgCl, respectively. Both anodic and cathodic peak currents increased linearly with the potential scan rates. Compared with the supporting electrolyte of phosphate buffer solution, EMImTfa played an important role for the direct electron transfer between Myb and the BPG electrode. Further investigation suggested that Myb was adsorbed tightly on the surface of the BPG electrode in the presence of EMImTfa to form a stable, approximate monolayer Myb film. Myb adsorbed on the BPG electrode surface could retain its biological activity and showed a remarkable electrocatalytic activity for the reduction of H2O2 in an EMImTfa aqueous solution. Based on these, a third-generation biosensor could be constructed to directly detect the concentration of H2O2 in EMImTfa aqueous solution with a limit of detection of 3.24 × 10−8 M. [ABSTRACT FROM AUTHOR]

Abstract  Using 1-ethyl-2-methylimidazolium trifluoroacetate (EMImTfa) as the supporting electrolyte, a couple of well-defined and reversible redox peaks of Myb could be observed at the basal plane graphite (BPG) electrode through direct electron transfer between the protein and the BPG electrode, whose anodic and cathodic peak potentials were at −0.098 V and −0.144 V vs. Ag | AgCl, respectively. Both anodic and cathodic peak currents increased linearly with the potential scan rates. Compared with the supporting electrolyte of phosphate buffer solution, EMImTfa played an important role for the direct electron transfer between Myb and the BPG electrode. Further investigation suggested that Myb was adsorbed tightly on the surface of the BPG electrode in the presence of EMImTfa to form a stable, approximate monolayer Myb film. Myb adsorbed on the BPG electrode surface could retain its biological activity and showed a remarkable electrocatalytic activity for the reduction of H2O2 in an EMImTfa aqueous solution. Based on these, a third-generation biosensor could be constructed to directly detect the concentration of H2O2 in EMImTfa aqueous solution with a limit of detection of 3.24 × 10−8 M. [ABSTRACT FROM AUTHOR]

Cu–Ag bimetallic nanoparticles with atomic ratio of 2.1:1 and diameter in the range of 15–30 nm were decorated on acid-treated multi-walled carbon nanotubes by a chemical reduction method, which was characterized by transmission electron microscope (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). The Cu–Ag/MWNTs nanocomposites were used to construct a modified electrode toward biosensing of H2O2 with a high sensitivity. The catalytic ability of MWNTs/Cu–Ag toward H2O2 was much better than that of MWNTs/Cu and MWNTs/Ag, which indicated that there is a cooperation effect between Cu and Ag. [ABSTRACT FROM AUTHOR]

Acid-treated multi-walled carbon nanotubes (MWNTs) were immobilized on the surface of a glassy carbon electrode to form an MWNT-modified electrode. The electrocatalytic response of the modified electrode towards tryptophan (Trp) was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results demonstrated that the modified electrode exhibited a high degree of catalytic activity towards the oxidation of Trp. An oxidation peak was obtained in Trp solution at the MWNT-modified electrode. Compared with a bare electrode, the peak current had obviously increased, and the peak potential had shifted in a negative direction. However, under the same conditions, no response was observed for other amino acids. The oxidation peak currents were proportional linearly to the concentration of Trp, a property which could be utilized to detect Trp. The determination conditions, such as the concentration, the composition and the pH values of the supporting electrolyte, accumulation time, as well as scan rate etc. were optimized. Under the chosen conditions, the DPV peak current is linear to the concentration of Trp in the range of 2.5 × 10-7 to 1.0 × 10-4 mol L-1, and the detection limit is 2.7 × 10-8 mol L-1. Moreover, the detection is free of interference from other amino acids. The modified electrode has been successfully applied to determine the concentration of Trp in composite amino acid injections, and it displays excellent repeatability and higher sensitivity. [ABSTRACT FROM AUTHOR]

Cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated chloride channel expressed in a wide variety of epithelial cells, mutations of which are responsible for the hallmark defective chloride secretion observed in cystic fibrosis (CF). Although CFTR has been implicated in bicarbonate secretion, its ability to directly mediate bicarbonate secretion of any physiological significance has not been shown. We demonstrate here that endometrial epithelial cells possess a CFTR-mediated bicarbonate transport mechanism. Co-culture of sperm with endometrial cells treated with antisense oligonucleotide against CFTR, or with bicarbonate secretion-defective CF epithelial cells, resulted in lower sperm capacitation and egg-fertilizing ability. These results are consistent with a critical role of CFTR in controlling uterine bicarbonate secretion and the fertilizing capacity of sperm, providing a link between defective CFTR and lower female fertility in CF. [ABSTRACT FROM AUTHOR]

The article offers information on a study that focuses on the extraction of triterpenoids and flavonoids from chloroform fraction of Dracocephalum peregrinum of the Lamiaceae family. It is mentioned that the air-dried and powdered whole grasses of the plant were refluxed with ethanol and after removing the solvent, the residue was partitioned sequentially.

The article discusses a study that examines a contact-dependent mechanism by which Mycobacterium leprae induces peripheral nerve demyelination. The authors of the study used an in vitro coculture system to identify the Erk1/2 pathway as a key intracellular signaling pathway activated in Schwann cells by M. leprae. This process of breaking down myelin can be blocked by Herceptin and kinase inhibitors.