miR-137, a new target for post-stroke depression?

Expression of miR-137 is downregulated in brain tissue from patients with depression and suicidal behavior, and is also downregulated in peripheral blood from stroke patients. However, it is not yet known if miR-137 acts as a bridge between stroke and depression. To test this, we used middle cerebral artery occlusion and chronic mild stress to establish a post-stroke depression model in rats. Compared with controls, we found significantly lower miR-137 levels in the brain and peripheral blood from post-stroke depression rats. Injection of a miR-137 antagonist into the brain ventricles upregulated miR-137 levels, and improved behavioral changes in post-stroke depression rats. Luciferase assays showed miR-137 bound to the 3＇UTR of Grin2A, regulating Grin2A expression in a neuronal cell line. Grin2A gene overexpression in the brain of post-stroke depression rats, no- ticeably suppressed the inhibitory effect of miR-137 on post-stroke depression. Overall, our results show that miR-137 suppresses Grin2A protein expression through binding to Grin2A mRNA, thereby exerting an inhibitory effect on post-stroke depression. Our results offer a new therapeutic direction for post-stroke depression.

Large Room-Temperature Magnetoresistance in van der Waals Ferromagnet/Semiconductor Junctions

A magnetic tunnel junction(MTJ)is the core component in memory technologies,such as the magnetic random-access memory,magnetic sensors and programmable logic devices.In particular,MTJs based on twodimensional van der Waals(vd W)heterostructures offer unprecedented opportunities for low power consumption and miniaturization of spintronic devices.However,their operation at room temperature remains a challenge.Here,we report a large tunnel magnetoresistance(TMR)of up to 85%at room temperature(T=300 K)in vdW MTJs based on a thin(<10 nm)semiconductor spacer WSe_(2)layer embedded between two Fe_(3)GaTe_(2e)lectrodes with intrinsic above-room-temperature ferromagnetism.The TMR in the MTJ increases with decreasing temperature up to 164%at T=10 K.The demonstration of TMR in ultra-thin MTJs at room temperature opens a realistic and promising route for next-generation spintronic applications beyond the current state of the art.

Surface defects in 4H-SiC homoepitaxial layers

Although a high-quality homoepitaxial layer of 4H‑silicon carbide(4H-SiC)can be obtained on a 4°off-axis substrate using chemical vapor deposition,the reduction of defects is still a focus of research.In this study,several kinds of surface defects in the 4H-SiC homoepitaxial layer are systemically investigated,including triangles,carrots,surface pits,basal plane dislocations,and step bunching.Themorphologies and structures of surface defects are further discussed via optical microscopy and potassium hydroxide-based defect selective etching analysis.Through research and analysis,we found that the origin of surface defects in the 4H-SiC homoepitaxial layer can be attributed to two aspects:the propagation of substrate defects,such as scratches,dislocation,and inclusion,and improper process parameters during epitaxial growth,such as in-situ etch,C/Si ratio,and growth temperature.It is believed that the surface defects in the 4H-SiC homoepitaxial layer can be significantly decreased by precisely controlling the chemistry on the deposition surface during the growth process.

Enhancing Interest Forwarding for Fast Recovery from Unanticipated Data Access Failure in NDN

We show that an aggregated Interest in Named Data Networking (NDN) may fail to retrieve desired data since the Interest previously sent upstream for the same content is judged as a duplicate one and then dropped by an upstream node due to its multipath forwarding. Furthermore, we propose NDRUDAF, a NACK based mechanism that enhances the Interest forwarding and enables Detection and fast Recovery from such Unanticipated Data Access Failure. In the NDN enhanced with NDRUDAF, the router that aggregates the Interest detects such unanticipated data access failure based on a negative acknowledgement from the upstream node that judges the Interest as a duplicate one. Then the router retransmits the Interest as soon as possible on behalf of the requester whose Interest is aggregated to fast recover from the data access failure. We qualitatively and quantitatively analyze the performance of the NDN enhanced with our proposed NDRUDAF and compare it with that of the present NDN. Our experimental results validate that NDRUDAF improves the system performance in case of such unanticipated data access failure in terms of data access delay and network resource utilization efficiency at routers.

LED Modulation Characteristics in a Visible-Light Communication System

This paper conducts a research on modulation characteristics of blue light-emitting diodes (LEDs) used in a visible-light communication (VLC) system. Through analysis of the modulation characteristics of LEDs with different emitting sizes, we find that there is a similar linear relationship between LED’s 3dB bandwidth and the operation current density. This experiment also shows that high series resistance is one major issue that limits our LED's modulation speed. To further improve the LED bandwidth, the resistance can be reduced by optimizing device layout as well as reducing material bulk resistance. Clearly, this study provides an approach to increase the modulation bandwidth of GaN-based LEDs for VLC systems.

Nonlinear oscillation characteristics of magnetic microbubbles under acoustic and magnetic fields

Microbubbles loaded with magnetic nanoparticles(MMBs) have attracted increasing interests in multimode imaging and drug/gene delivery and targeted therapy. However, the dynamic behaviors generated in diagnostic and therapeutic applications are not clear. In the present work, a novel theoretical model of a single MMB was developed, and the dynamic responses in an infinite viscous fluid were investigated under simultaneous exposure to magnetic and acoustic fields. The results showed that the amplitude reduces and the resonant frequency increases with the strength of the applied steady magnetic field and the susceptibility of the magnetic shell. However, the magnetic field has a limited influence on the oscillating. It is also noticed that the responses of MMB to a time-varying magnetic field is different from a steady magnetic field. The subharmonic components increase firstly and then decrease with the frequency of the magnetic field and the enhanced effect is related to the acoustic driving frequency. It is indicated that there may be a coupling interaction effect between the acoustic and magnetic fields.

Cloning,Sequencing and Analysis of DDX3Y Gene in Five Male Equus Animals

[ Objective] This study analyzed the differences in DDX3 Y gene sequences among male horse, male donkey, male mule, male hinny and male foal to investigate the relationship between DDX3Y gene structure and the mechanism of infertility in male Equus fetus × asirms. [ Method] Partial sequences of DDX3Y gene in male horse, male donkey, male mule, male hinny and male foal were obtained by genome comparison, sequencing and cloning, and compared by bioinformatics methods. [ Result] The CDS regions varied in 5 base pairs and two amino acids. DDX3Y protein was predicted to be an unstable protein. In addition, the results also showed that DDX3 Y gene in male horse displayed a closer phylogenetic relationship to male mule and male foal; DDX3Y gene in male donkey displayed a closer phylogenetic relationship to male hinny. [ Conclusion] This study provided scientific basis for further exploring the function of DDX3 Y gene and the mecha- nism of reproductive regulation in male Equus ferus × asinus.

A Comparison of the Effects of Pentoxifylline on Quality of Fresh and Frozen-thawed Bull Spermatozoa

[Object]This study aimed to examine the effects of 3,7-dimethyl-1-（5-oxo-hexyl）-xanthine（pentoxifylline,PF）on the motility,mitochondrial activity,acrosome integrity and fertilization rate of spermatozoa in both fresh and frozen-thawed bull semen.[Method]Fresh and frozen-thawed bull spermatozoa were exposed to 5 mmol/L PF with untreated samples as controls.[Result]Fresh spermatozoa showed reduced（P〈0.05）motility after 2 h incubation with PF whereas,surprisingly,frozen-thawed samples exhibited increased sperm motility（P〈0.05）after 2 h incubation with PF and they also showed enhanced longevity compared to controls.Mitochondrial activity in both fresh and frozen-thawed bull spermatozoa increased（P〈0.05）during 4 h incubation with PF whereas acrosome integrity remained unchanged in both types of semen.However,treatment with 5 mmol/L PF did not influence the in vitro fertilization efficiency of fresh spermatozoa but improved significantly（P〈0.05）that of frozen-thawed spermatozoa.[Conclusion]These results indicate that PF can improve sperm quality of frozenthawed bull semen,and may improve pregnancy rates in bovine artificial insemination programmes employing frozen semen.

GaN-based LEDs for light communication

Rapid improvement in the efficiency of GaN-based LEDs not only speed up its applications for general illumination, but offer the possibilities for data transmission. This review is to provide an overview of current progresses of GaN-based LEDs for light communications. The modulation bandwidth of GaN-based LEDs has been first improved by optimizing the LED epilayer structures and the modulation bandwidth of 73 MHz was achieved at the driving current density of 40 A/cm2 by changing the multi-quantum well structures. After that, in order to increase the current density tolerance, different parallel flip-chip micro-LED arrays were fabricated. With a high injected current density of ~7900 A/cm2, a maximum modulation bandwidth of ~227 MHz was obtained with optical power greater than 30 mW. Besides the increase of carrier concentrations, the radiative recombination coefficient B was also enhanced by modifying the photon surrounding environment based on some novel nanostructures such as resonant cavity, surface plasmon, and photonic crystals. The optical 3 dB modulation bandwidth of GaN-based nanostructure LEDs with Ag nanoparticles was enhanced by 2 times compared with GaN-based nanostructure LEDs without Ag nanoparticles.Our results demonstrate that using the QW-SP coupling can effectively help to enhance the carrier spontaneous emission rate and also increase the modulation bandwidth for LEDs, especially for LEDs with high intrinsic IQE. In addition, we discuss the progress of the faster color conversion stimulated by GaN-based LEDs.

H_2O_2调控TiO_2体系中活性氧物种的产生及其五氯酚的降解过程

五氯酚的二氧化钛光催化氧化技术由于降解效率高、毒性低等优点受到了广泛关注.如何合理调控五氯酚降解过程中高毒性中间产物的产生是目前研究的热点.而五氯酚的光催化降解过程与活性氧物种的产生息息相关.基于此,本文研究了H_2O_2的加入对3种不同类型Ti O_2光催化体系中所产生的ROS包括·OH、O_2^(·-)和H_2O_2浓度及其对五氯酚降解效率和降解过程的影响.结果显示,加入H_2O_2后,P25溶液所产生的3种ROS的量均增加,且五氯酚的降解速率k增大.锐钛矿Ti O_2溶液所产生的·OH减少,O_2^(·-)和H_2O_2含量增多,五氯酚的降解速率降低.金红石相Ti O_2溶液所产生的3种ROS的量均增加,且五氯酚的降解速率提高50倍.用高效液相色谱法和发光菌抑制法分别对3种Ti O_2/H_2O_2体系光催化降解五氯酚过程中所产生的中间产物及其急性毒性的影响进行了鉴定.结果显示,降解过程中均没有高毒性中间产物四氯苯醌产生,且降解过程中的急性毒性显著降低.这些结果表明,H_2O_2的加入可以调控Ti O_2光催化体系中ROS的产生及五氯酚的降解过程,显著降低了五氯酚降解过程中的急性毒性.

Size distribution of particulate polycyclic aromatic hydrocarbons in fresh combustion smoke and ambient air: A review

Polycyclic aromatic hydrocarbons(PAHs) are ubiquitous in the atmosphere and they mostly stem from the imperfect combustion of fossil fuels and biofuels.PAHs are inherently associated with homogenous fine particles or distributed to different-sized particles during the aging of air masses.PAHs carried by fine particles undergo a long-range transport to remote areas while those adsorbed on coarse particles have a shorter lifetime in ambient air.More importantly, PAHs with higher molecular weights tend to be bound with finer particles and can deeply enter the lungs, posing severe health risks to humans.Thus, the environmental fate and health effects of particulate PAHs are strongly size-dependent.This review summarizes the size distributions of particulate PAHs freshly emitted from combustion sources as well as the distribution patterns of PAHs in ambient particles.It was found that PAHs from stationary sources are primarily bound to fine particles, which are slightly larger than particles to which PAHs from mobile sources are bound.In ambient air, particulate PAHs are distributed in larger size modes than those in the combustion fume, and the particle size decreases with PAH molecular weight increasing.The relevant mechanisms and influencing factors of particle size distribution changes are illustrated in this article, which are essentially attributed to combustion and ambient temperature as well as the physical and chemical properties of PAHs.Overall, the study on the particle size distribution of PAHs will contribute for a full understanding of the origin, atmospheric behaviors and health effects of particulate PAHs.

Beclin 1 cleavage by caspase-3 inactivates autophagy and promotes apoptosis

Autophagy and apoptosis are both highly regulated biological processes that play essential roles in tissue homeostasis,development and diseases.Autophagy is also described as a mechanism of death pathways,however,the precise mechanism of how autophagy links to cell death remains to be fully understood.Beclin 1 is a dual regulator for both autophagy and apoptosis.In this study we found that Beclin 1 was a substrate of caspase-3 with two cleavage sites at positions 124 and 149,respectively.Furthermore,the autophagosome formation occurred,followed by the appearance of morphological hallmarks of apoptosis after staurosporine treatment.The cleavage products of Beclin 1 reduced autophagy and promoted apoptosis in HeLa cells and the cells in which Beclin 1 was stably knocked down by specific shRNA.In addition,the cleavage of Beclin 1 resulted in abrogating the interaction between Bcl-2 with Beclin 1,which could be blocked by z-VAD-fmk.Thus,our results suggest that the cleavage of Beclin 1 by caspase-3 may contribute to inactivate autophagy leading towards augmented apoptosis.

Comparative sorption and desorption behaviors of PFHx S and PFOS on sequentially extracted humic substances

The sorption and desorption behaviors of two perfluoroalkane sulfonates（PFSAs）, including perfluorohexane sulfonate（PFHx S） and perfluorooctane sulfonate（PFOS） on two humic acids（HAs） and humin（HM）, which were extracted from a peat soil, were investigated. The sorption kinetics and isotherms showed that the sorption of PFOS on the humic substances（HSs） was much higher than PFHx S. For the same PFSA compound, the sorption on HSs followed the order of HM 〉 HA2 〉 HA1. These suggest that hydrophobic interaction plays a key role in the sorption of PFSAs on HSs. The sorption capacities of PFSAs on HSs were significantly related to their aliphaticity, but negatively correlated to aromatic carbons,indicating the importance of aliphatic groups in the sorption of PFSAs. Compared to PFOS,PFHx S displayed distinct desorption hysteresis, probably due to irreversible pore deformation after sorption of PFHx S. The sorption of the two PFSAs on HSs decreased with an increase in p H in the solution. This is ascribed to the electrostatic interaction and hydrogen bonding at lower p H. Hydrophobic interaction might also be stronger at lower p H due to the aggregation of HSs.

New insights into the structural basis of DNA recognition by HINa and HINb domains of IFI16

Interferon gamma-inducible protein 16(IFI16)senses DNA in the cytoplasm and the nucleus by using two tandem hematopoietic interferon-inducible nuclear(HIN)domains,HINa and HINb,through the cooperative assembly of IFI16 filaments on double-stranded DNA(dsDNA).The role of HINa in sensing DNA is not clearly understood.Here,we describe the crystal structure of the HINa domain in complex with DNA at 2.55A°resolution and provide the first insight into the mode of DNA binding by the HINa domain.The structure reveals the presence of two oligosaccharide/nucleotide-binding(OB)folds with a unique DNA-binding surface.HINa uses loop L45 of the canonical OB2 fold to bind to the DNA backbone.The dsDNA is recognized as two single strands of DNA.Interestingly,deletion of HINb compromises the ability of IFI16 to induce IFN-b,while HINa mutants impaired in DNAbinding enhance the production of IFN-b.These results shed light on the roles of IFI16 HIN domains in DNA recognition and innate immune responses.

Crystallinity engineering of Au nanoparticles on graphene for in situ SERS monitoring of Fenton-like reaction

Fabrication of multifunctional nanoplatform to in situ monitor Fenton reaction is of vital importance to probe the underlying reaction process and design high-performance catalyst. Herein, a hybrid catalyst comprising of single-crystalline Au nanoparticles (SC Au NPs) on reduced graphene oxide (RGO) sheet was prepared, which not only exhibited an excellent ^(1)O_(2) mediated Fenton-like catalytic activity in promoting rhodamine 6G (R6G) degradation by activating H_(2)O_(2), but also displayed a sensitive surface-enhanced Raman spectroscopy (SERS) detection performance to R6G with a linear response range from 1.0×10^(-8) mol/L to 1.0×10^(-5) mol/L thus providing a powerful and versatile nanoplatform for in situ SERS monitoring Fenton-like catalytic reaction. The integration of catalytic and SERS activities into a single nanostructure are expected to provide great potentials for practical applications in environmental catalysis.

Unprecedented Two‑Step Chemiluminescence of Polyamine‑Functionalized Carbon Nanodots Induced by Fenton‑Like System

We reported an unprecedented chemiluminescence(CL)behavior of polyamine-functionalized carbon dots induced by Fe^(3+)–H_(2)O_(2) Fenton-like system.The firststep CL intensity increased with the increasing of the concentration of H_(2)O_(2) and Fe^(3+),when the Fe^(3+)concentration came to 10^(−3) M,the unprecedented two-step CL behavior appeared.The CL intensity of BPEI-CDs induced by Fenton-like system was about 10 times stronger than that of naked CDs.The possible two-step CL mechanism was speculated based on the photoluminescence spectra,CL emission spectra,and the effects of radical scavengers on the CL intensity.Radiative recombination of the injected holes by strong oxidant perferrate formed through Fe^(3+)–H_(2)O_(2) reaction and the;OH generated from successive Fenton reaction with the thermally excited electrons was proposed,which further facilitate full understanding about the optical properties of carbon dots.

Exposure to perfluorooctane sulfonate reduced cell viability and insulin release capacity of β cells

Per-and polyfluoroalkyl substances(PFAS)are found to have multiple adverse outcomes on human health.Recently,epidemiological and toxicological studies showed that exposure to PFAS had adverse impacts on pancreas and showed association with insulin abnormalities.To explore how PFAS may contribute to diabetes,we studied impacts of perfluorooctane sul-fonate(PFOS)on cell viability and insulin release capacity of pancreatic β cells by using in vivo and in vitro methods.We found that 28-day administration with PFOS(10 mg/(kg body weight·day))caused reductions of pancreas weight and islet size in male mice.PFOS admin-istration also led to lower serum insulin level both in fasting state and after glucose infusion among male mice.For cell-based in vitro bioassay,we used mouse β-TC-6 cancer cells and found 48-hr exposure to PFOS decreased the cell viability at 50 μmol/L.By measuring insulin content in supernatant,48-hr pretreatment of PFOS(100 μmol/L)decreased the insulin re-lease capacity of β-TC-6 cells after glucose stimulation.Although these concentrations were higher than the environmental concentration of PFOS,it might be reasonable for high con-centration of PFOS to exert observable toxic effects in mice considering mice had a faster removal efficiency of PFOS than human.PFOS exposure(50 μmol/L)to β-TC-6 cells induced intracellular accumulation of reactive oxidative specie(ROS).Excessive ROS induced the re-active toxicity of cells,which eventually invoke apoptosis and necrosis.Results in this study provide evidence for the possible causal link of exposure to PFOS and diabetes risk.

Dechloranes exhibit binding potency and activity to thyroid hormone receptors

Dechloranes are a group of halogenated flame retardants with a basic bicyclo[2.2.1]heptene,including Dechlorane Plus(DP),Dechlorane 602(Dec 602),Dechlorane 603(Dec 603)and Dechlorane 604(Dec 604).A few epidemiological investigations and animal experiments have shown that DP exhibited thyroid-interfering effects.In the present study,we investigated whether DP and three other dechloranes could interfere the thyroid function through thyroid hormone receptors(TRs,TRαand TRβ)signaling pathways.The binding affinities of the four dechloranes to the two TRs were determined by fluorescence competitive binding assay.It was found that all the four dechloranes could bind with the two TRs.The relative potency(RP)values ranged from nd(not detectable)to 0.0667.Between the two TRs,dechloranes were more inclined to bind with TRβ,which implies that the thyroid interference effect of dechloranes may have selectivity in different tissues and organs.TRs-mediated luciferase reporter gene assay and T-screen assay showed that all the four dechloranes exhibited antagonistic activity to TRs in the cells.Taken together,our results demonstrated that dechloranes might interfere with thyroid function by binding with TRs and acting as TR antagonists.The health risk of highly exposed human populations should be of serious concern because of the high hazard quotient calculated from our cell assay results.

In vitro expression and analysis of the 826 human G protein-coupled receptors

G protein-coupled receptors （GPCRs） are involved in all human physiological systems where they are responsible for transducing extracellular signals into cells. GPCRs signal in response to a diverse array of stimuli including light, hormones, and lipids, where these signals affect downstream cascades to impact both health and disease states. Yet, despite their importance as therapeutic tar- gets, detailed molecular structures of only 30 GPCRs have been determined to date. A key challenge to their structure determination is adequate protein expression. Here we report the quantification of protein expression in an insect cell expression system for all 826 human GPCRs using two different fusion constructs. Expression char- acteristics are analyzed in aggregate and among each of the five distinct subfamilies. These data can be used to identify trends related to GPCR expression between dif- ferent fusion constructs and between different GPCR families, and to prioritize lead candidates for future structure determination feasibility.