FeS2 nanoparticles on reduced graphene oxide: an efficient electrocatalyst for nitrate electroreduction to ammonia.

Electrocatalytic nitrate-to-ammonia conversion (NO3RR) represents a promising approach for achieving both sustainable NH3 synthesis and wastewater treatment. Herein, we first demonstrate the great feasibility of using pyrite FeS2 as an effective and durable NO3RR catalyst. The developed FeS2 nanoparticles supported on reduced graphene oxide (FeS2/RGO) deliver the maximum NH3-Faradaic efficiency of 83.7% with a corresponding NH3 yield of 2.32 mg h-1 cm-2 at -0.6 V (RHE). FeS2/RGO also exhibits excellent stability during the cycling and long-term electrolysis tests. DFT calculations reveal that NO3- can be efficiently activated on surface Fe sites, which can drive the NO3RR process through an NHO pathway with a low energy barrier.

Significant Association of the Catechol-O-Methyltransferase Gene Polymorphism (rs4680) and Opioid Use Disorder in Asian Populations, but not Caucasian Populations: A Meta-analysis.

Objective: Previous studies have reported on the association between the rs4680 polymorphism in the Catechol-O-methyltransferase (COMT) gene and opioid use disorder (OUD) with inconsistent outcomes. The goal of this study was to examine the correlation of the rs4680 polymorphism and OUD using a meta-analysis approach. Methods: Six electronic databases, including PubMed, Web of Science, Cochrane Library, EMBASE, Wanfang and CNKI, were searched thoroughly for relevant studies on the association of the rs4680 polymorphism and OUD up to September, 2021. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to test the association. Statistical analyses was performed using RevMan 5.3 software. Results: Eleven studies with 13 independent cohorts encompassing 2538 cases and 2519 controls were included in this study. In the overall analysis, the rs4680 polymorphism was not associated with OUD susceptibility. Subgroup analyses suggested that rs4680 was significantly correlated with OUD in Asian populations: VV vs. MM, OR = 1.46, 95% CI 1.05-2.02, p = 0.02; VM vs. MM, OR = 1.44, 95% CI 1.04-2.00, p = 0.03; VV+VM vs. MM, OR = 1.45, 95% CI 1.07-1.99, p = 0.02. However, the pooled data did not suggest any significant association in the Caucasian population. Conclusion: This meta-analysis supports a significant association between the rs4680 polymorphism and predisposition to OUD in Asians, carriers of VV and VM genotypes appear to have an increased susceptibility to OUD. However, the association does not exist in Caucasians.

Identification of Mouse Claustral Neuron Types Based on Their Intrinsic Electrical Properties.

Although its dense connections with other brain areas suggests that the claustrum is involved in higher-order brain functions, little is known about the properties of claustrum neurons. Using whole-cell patch clamp recordings in acute brain slices of mice, we characterized the intrinsic electrical properties of more than 300 claustral neurons and used unsupervised clustering of these properties to define distinct cell types. Differences in intrinsic properties permitted separation of interneurons (INs) from projection neurons (PNs). Five subtypes of PNs could be further identified by differences in their adaptation of action potential (AP) frequency and amplitude, as well as their AP firing variability. Injection of retrogradely transported fluorescent beads revealed that PN subtypes differed in their projection targets: one projected solely to subcortical areas while three out of the remaining four targeted cortical areas. INs expressing parvalbumin (PV), somatostatin (SST), or vasoactive intestinal peptide (VIP) formed a heterogenous group. PV-INs were readily distinguishable from VIP-INs and SST-INs, while the latter two were clustered together. To distinguish IN subtypes, an artificial neural network was trained to distinguish the properties of PV-INs, SST-INs, and VIP-INs, as independently identified through their expression of marker proteins. A user-friendly, machine-learning tool that uses intrinsic electrical properties to distinguish these eight different types of claustral cells was developed to facilitate implementation of our classification scheme. Systematic classification of claustrum neurons lays the foundation for future determinations of claustrum circuit function, which will advance our understanding of the role of the claustrum in brain function.

The role of altered brain structural connectivity in resilience, vulnerability, and disease expression to schizophrenia.

BACKGROUND: Schizophrenia (SCZ) is a highly heritable disorder associated with brain connectivity changes. Although the mechanism of disease expression and vulnerability of SCZ have been reported by previous studies, the mechanism of resilience to SCZ based on the brain structural connectivity is poorly understood. The goal of the present study was to identify the structural brain connectivity related with the resilience to SCZ, which is defined here as the capacity to avoid or delay the onset of SCZ in unaffected siblings of SCZ probands. METHOD: We collected diffusion tensor imaging (DTI) data of 49 medication-naive, first-episode SCZ (FE-SCZ) patients, 56 unaffected siblings of SCZ probands (SIB-SCZ), and 90 healthy controls. Then we used graph theoretical approach to calculate the topological properties of the brain structural network, including global, subnetwork, and regional parameters. Finally, we compared the parameters between the three groups, and identified the brain structural network related to the resilience, vulnerability and disease expression to SCZ. RESULTS: With respect to resilience, only the SIB-SCZ showed significantly increased connectivity in the subnetworks of the left cuneus-precuneus and left posterior cingulate gyrus-precuneus, and in brain areas of right supramarginal gyrus and right inferior temporal gyrus. With respect to vulnerability, both the FE-SCZ and SIB-SCZ had decreased cluster coefficients and local efficiency, and decreased nodal efficiency in the right medial superior frontal gyrus and right medial orbital superior frontal gyrus compared with the healthy controls. With respect to disease expression, only the FE-SCZ group showed decreased or increased global, subnetwork, and nodal connectivity in broader brain regions compared with the healthy controls. CONCLUSION: Difference in the topological properties of brain structural connectivity not only reflect the underlying mechanism of vulnerability but also that of resilience to schizophrenia. Alteration in the brain structural connectivity associating with resilience and disease expression may contribute to the onset of SCZ.

On-line coupling of hydrophilic ionic liquids-based polymer monolith microextraction to capillary liquid chromatography with amperometric detection: An ultrasensitive residue analysis method for glycopeptide antibiotics.

A hydrophilic ionic liquids based polymer monolith microextraction (PMME) column (poly(ionic liquid-co-hydroxyethyl methacrylate-co-ethylene dimethacrylate); poly(IL-co-HEMA-co-EDMA)) was prepared for the first time in a capillary and utilized in PMME for the enrichment of glycopeptide antibiotics (GAs), followed by the online coupling analysis of capillary liquid chromatography with amperometric detection (cLC-AD). The prepared monolith exhibited large through pores and good storage stability, as well as a selective extraction machanism for GAs that was attributed to the hydrogen bonding, hydrophilic, electrostatic and π-π interactions between GAs and the imidazolium cations or hydroxyl groups on the surface of absorbent. Several experimental parameters, such as sample flow rate, composition of eluent and solvent desorption conditions, were examined to improve the extraction efficiency of PMME. Under the optimal conditions, the proposed PMME-cLC-AD method provides detection limits (S/N = 3) of 1.0-8.0 µg L-1 for three GAs, which are 1000-fold lower than those obtained by cLC-AD, with a wide linear range of 10.0-12000.0 µg L-1. It was successfully applied for the analysis of GAs residues in feed samples with good recoveries (80.3-119.1%) and satisfied intra-day/inter-day precision (<10%). Compared with LC-3Q-MS method, the proposed online approach has the merits of simple, low cost, smaller matrix interference and environmental friendly, which is demonstrated to be a feasible tool for residue analysis of peptide antibiotics in food safety application.

Multivariate systems of nonexpansive operator equations and iterative algorithms for solving them in uniformly convex and uniformly smooth Banach spaces with applications.

We prove some existence theorems for solutions of a certain system of multivariate nonexpansive operator equations and calculate the solutions by using the generalized Mann and Halpern iterative algorithms in uniformly convex and uniformly smooth Banach spaces. The results of this paper improve and extend the previously known ones in the literature.

A kind of system of multivariate variational inequalities and the existence theorem of solutions.

Let K be a nonempty closed convex and bounded subset of a reflexive Banach space X. Let [Formula: see text] be N-variables monotone demi-continuous mappings from [Formula: see text] into X. Then: (1) the system of multivariate variational inequalities [Formula: see text] has a solution [Formula: see text]; (2) the set of solutions of this system of multivariate variational inequalities is closed convex in [Formula: see text]; (3) if [Formula: see text] are also strictly monotone, this system of multivariate variational inequalities has a unique solution.

Remote Regulation of Membrane Channel Activity by Site-Specific Localization of Lanthanide-Doped Upconversion Nanocrystals.

The spatiotemporal regulation of light-gated ion channels is a powerful tool to study physiological pathways and develop personalized theranostic modalities. So far, most existing light-gated channels are limited by their action spectra in the ultraviolet (UV) or visible region. Simple and innovative strategies for the specific attachment of photoswitches on the cell surface without modifying or genetically encoding channel structures, and more importantly, that enable the remote activation of ion-channel functions within near-infrared (NIR) spectral window in living systems, remain a challenging concern. Herein, metabolic glycan biosynthesis is used to achieve site-specific covalent attachment of near-infrared-light-mediated lanthanide-doped upconversion nanocrystals (UCNs) to the cell surface through copper-free click cyclization. Upon irradiation with 808 nm light, the converted emission at 480 nm could activate a light-gated ion channel, channelrhodopsins-2 (ChR2), and thus remotely control the cation influx. This unique strategy provides valuable insights on the specific regulation membrane-associated activities in vivo.

ψ-Contraction and [Formula: see text]-contraction in Menger probabilistic metric space.

The purpose of this paper is to present the definition of [Formula: see text]-contractive mapping and to discuss the relation of [Formula: see text]-contractive mappings and [Formula: see text]-contractive mappings. Furthermore, the generalized [Formula: see text]-contraction mapping principle has been proved without the uniqueness condition. Meanwhile, the generalized [Formula: see text]-contraction mapping principle has been obtained by using an ingenious method.

The complete mitochondrial genome of Yunnan black goat (Capra hircus).

Yunnan black goat (Capra hircus) is one of the famous native goat breed in China. In this study, the complete nucleotide sequence of Yunnan black goat mitochondrial genome was determined for the first time. Sequence analysis showed that the genome structure was in typical with other vertebra animals. It contained 22 tRNA genes, 2 ribosomal RNA genes, 13 protein-coding genes and 1 control region (D-loop region). The base composition was A (33.6%), G (13.1%), C (26.0%) and T (27.3%), so the percentage of A and T (60.9%) was higher than that of G and C.

Field-amplified sample injection in capillary electrophoresis with amperometric detection for the ultratrace analysis of diastereomeric ephedrine alkaloids.

A coupling method of field-amplified sample injection (FASI) CE with amperometric detection is developed for ultratrace analysis of ephedrine alkaloids stereoisomers. FASI was introduced by injecting electrokinetically the sample solution for 10 s into the capillary filled with highly conductive background electrolyte (BGE). The diastereomeric selectivity and the detection sensitivity were improved by using borate buffer of high ionic strength as BGE. Parameters affecting FASI and CE separation were investigated to achieve the optimal conditions. Four analytes were separated within 15 min using 200 mmol/L borate buffer (pH 9.5) and separation voltage of +18 kV, with detection potential at +1.0 V (vs. Ag/AgCl) and carbon disc electrode as working electrode. Excellent linearity was observed between peak current and concentration of analytes in the range of 0.1-100 ng/mL. The LODs (S/N = 3) for (-)-ephedrine, (+)-pseudoephedrine, (-)-N-methylephedrine and (+)-N-methylpseudoephedrine were 39.3, 54.9, 30.8, and 44.1 pg/mL, respectively. The proposed method was successfully applied to the determination of alkaloids in Ephedra sinica, with results agreed well with HPLC method. Mean recoveries of 102.1-109.7% and RSDs less than 6% were found. And the merits of high sensitivity and selectivity, as well as a simple and stable operation, have been demonstrated.

The complete mitochondrial genome of Sus cebifrons (Sus, Suidae).

In this work, we report the complete mitochondrial genome sequence of Sus cebifrons (Visayan warty pig). The total length of the mitogenome was 16,475 bp, and its overall base composition was estimated to be 35.0% for A, 25.8% for T, 26.2% for C and 13.0% for G, indicating an A-T (60.8%)-rich feature in Sus cebifrons mitogenome. It contained the typical structure of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a noncoding control region (D-loop region). The arrangement of these genes was the same as that found in other pigs. The complete mitochondrial genome sequence of the Sus cebifrons would provide new genetic resources for pig domestication study.

Next-generation transgenic mice for optogenetic analysis of neural circuits.

Here we characterize several new lines of transgenic mice useful for optogenetic analysis of brain circuit function. These mice express optogenetic probes, such as enhanced halorhodopsin or several different versions of channelrhodopsins, behind various neuron-specific promoters. These mice permit photoinhibition or photostimulation both in vitro and in vivo. Our results also reveal the important influence of fluorescent tags on optogenetic probe expression and function in transgenic mice.

[Chemical constituents from Usnea longgisima, a traditional mongolian medicine].

OBJECTIVE: To study the chemical constituents of the whole lichen of Usnea longissima. METHOD: The compounds were separated by silica gel, Sephadex LH-20 chromatography and high performance liquid chromatography (HPLC). The structures of the compounds isolated were identified by physico-chemical properties and spectral analysis. RESULT: Ten compounds were isolated and their structures were identified as (4aR,9bS)-2,6-diactyl-3,4a,7,9-tetrahydroxy-8,9b-dimethyl-1-oxo-1,4,4a, 9b-tetrahydrodibenzo [b,d]furan (1), (+)-usnic acid (2), orcinol (3), 18R-hydroxydihydroalloprotolichensterinic acid (4), 5, 8-epidioxy-5alpha, 8alpha-ergosta-6, 22E-dien-3beta-ol (5), ethyl everninate (6), arabitol(7), apigenin 7-O-beta-D-glucuronide (8), 3-hydroxy-5-methoxy-2-methylbenzoic acid(9), friedelin(10). CONCLUSION: Compound 1 was a new compound. Compound 8 was isolated from genu Usnea for the first time and compounds 3, 4 and 7 were isolated from U. longissima for the first time.

[Diffusion tensor imaging analyses of white matter in healthy siblings of schizophrenics].

OBJECTIVE: To explore the diffusion tensor imaging (DTI) features of white matter in healthy siblings of schizophrenics. METHODS: Twenty healthy siblings of schizophrenics and 45 healthy controls without a family history of mental disorder. They responded to advertised recruitment during December 2009 and March 2012. All participants underwent diffusion weighted magnetic resonance images with a single-shot echo planar imaging (EPI) sequence aligned to straight axial plane. The fractional anisotropy (FA) images of two groups underwent two-sample t-test with SPM5 software. RESULTS: The healthy siblings of schizophrenics demonstrated a significant decrease of regional white matter FA values in right anterior cingulated (MNI: x = 9, y = 43, z = 4; cluster = 106). CONCLUSION: Reduced white matter integrity in right anterior cingulated may be a risk actor of schizophrenia.

Chronic exposure to high fatty acids impedes receptor agonist-induced nitric oxide production and increments of cytosolic Ca2+ levels in endothelial cells.

Dyslipidemia is a common metabolic disorder in diabetes. Nitric oxide (NO) production from endothelium plays the primary role in endothelium-mediated vascular relaxation and other endothelial functions. Therefore, we investigated the effects of elevated free fatty acids (FFA) on the stimulation of NO production by phospholipase C (PLC)-activating receptor agonists (potent physiological endothelium-dependent vasodilators) and defined the possible alterations of signaling pathways implicated in this scenario. Exposure of bovine aortic endothelial cells (BAECs) to high concentrations of a mixture of fatty acids (oleate and palmitate) for 5 or 10 days significantly reduced NO production evoked by receptor agonists (bradykinin or ATP) in a time- and dose-dependent manner. Such defects were not associated with alterations of either endothelial NO synthase mass or inositol phospholipid contents but were probably due to reduced elevations of intracellular free Ca(2)(+) levels ([Ca(2)(+)](i)) under these conditions. Exposure of BAECs to FFA significantly attenuated agonist-induced [Ca(2)(+)](i) increases by up to 54% in a dose- and time-dependent manner. Moreover, bradykinin receptor affinity on the cell surface was significantly decreased by high concentrations of FFA. The morphology of BAECs was altered after 10-day culture with high FFA. Co-culture with protein kinase C (PKC) inhibitors or antioxidants was able to reverse the impairments of receptor agonist-induced NO production and [Ca(2)(+)](i) rises as well as the alteration of receptor affinity in BAECs exposed to FFA. These data indicate that chronic exposure to high FFA reduces NO generation in endothelial cells probably by impairing PLC-mediated Ca(2)(+) signaling pathway through activation of PKC and excess generation of oxidants.

Determination of endpoint of procedure for radix rehmanniae steamed based on ultraviolet spectrophotometry combination with continuous wavelet transform and kernel independent component analysis.

A method for determination of the endpoint of the procedure for radix rehmanniae steamed was proposed based on UV spectrophotometry combination with continuous wavelet transform and kernel independent component analysis (UV-CWT-KICA). In the proposed method, the raw UV spectra of the rehmanniae samples during steamed procedure were measured. The raw UV spectral data were firstly pretreated by CWT for elimination of the noise signal and enrichment of the spectral resolution, then the independent components (ICs) were estimated from the mixed CWT coefficient matrix. The results show that the ICs are chemical significance with their relative concentrations gradually decreasing or increasing during the first steamed period, and the endpoint of the steamed procedure can be determined by inspection of the relative concentration profiles, at which the ICs should be approached maximum or minimum. Furthermore, the estimated ICs of rehmanniae samples from different areas or with different grades are similar, and the relative concentration of the similar ICs in different groups are increasing or decreasing before the first 14 h, and nearly steady or some decreasing after 16 h. Based on the variations of the relative concentration profiles of the ICs, the endpoint of the steamed procedure can be determined as 15 h, while that determined by sensory analysis is 14-20 h. The proposed UV-CWT-KICA method can avoid the higher deviations of the endpoints that were determined by sensory analysis. It provides an alternative approach for determination of the endpoint of the procedure for processing traditional Chinese medicine (TCM).

[Determination of trace arsenic and mercury in antimony concentrates by hydride generation atomic fluorescence spectrometry].

A method for the determination of trace arsenic and mercury in antimony concentrates by hydride generation atomic fluorescence spectrometry was investigated. The method of dissolving sample and the effect of concomitant ion were studied. It was found that aqua regia can be used to dissolve the sample completely, with maximum quantities of dissolved arsenic and mercury. The interference of chemical elements in antimony concentrates was avoided by adding thiourea-Vc. The matrix of antimony was vaporized with tartaric acid during sample pre-treatment. Trace arsenic and mercury were determined in real samples. The detection limits of 0.220 ng x mL(-1) and 0.002 ng x mL(-1) were obtained, the relative standard deviations(RSD% = 11) are 1.47% and 0.52%, and the recoveries are 94.0%-103.0% and 98.7%-102.8% for As and Hg respectively. This method has proved rapid, accurate and highly sensitive.