Br-doping of g-C3N4 towards enhanced photocatalytic performance in Cr(Ⅵ)reduction

Semiconductor photocatalytic technology is widely recognized as one of the most promising technologies to solve current energy and environmental crisis, due to its ability to make effective use of solar energy. In recent years, graphite carbon nitride(g-C3N4), a new type of non-metallic polymer semiconductor photocatalyst, has rapidly become the focus of intense research in the field of photocatalysis because of its suitable bandgap energy, unique structure, and excellent chemical stability. In order to improve its intrinsic shortages of small specific surface area, narrow visible light response range, high electron-hole pair recombination rate, and low photon quantum efficiency, a simple method was utilized to synthesize Br-doped g-C3N4(CN–Br X, X = 5, 10, 20, 30), where X is a percentage mole ratio of NH4 Br to melamine. Experimental results showed that Br atoms were doped into the g-C3N4 lattice by replacing the bonded N atoms in the form of C–N=C, while the derived material retained the original framework of g-C3N4. The interaction of Br element with the g-C3N4 skeleton not only broadened the visible-light response of g-C3N4 to 800 nm with an adjustable band gap, but also greatly promoted the separation efficiency of the photogenerated charge carrier and the surface area. The photocurrent intensity of bare CN and CN–Br X(X = 5, 10, 20, 30) catalysts is calculated to be 1.5, 2.0, 3.1, 6.5, and 1.9 μA, respectively. And their specific surface area is measured to be 9.086, 9.326, 15.137, 13.397, and 6.932 m2/g. As a result, this Br-doped g-C3N4 gives significantly enhanced photocatalytic reduction of Cr(VI), achieving a twice enhancement over g-C3N4, with high stability during prolonged photocatalytic operation compared to bare g-C3N4 under visible light irradiation. Furthermore, an underlying photocatalytic reduction mechanism was proposed based on control experiments using radical scavengers.

水质采样专用多旋翼无人机及其控制系统

针对环境保护部门等用户对水质采样专用无人机的需求和具体要求,本文设计了水质采样专用四旋翼无人机,分别从无人机的部件、采水装置、电路模块等硬件设备,以及控制算法、采样流程等软件方面进行介绍.本文在四旋翼无人机动力学模型基础上,加入对水流冲击力的分析,设计四旋翼无人机的飞行采样模式,并对其有效性与实用性进行仿真测试与实践验证,完成了水质采样专用四旋翼无人机的手动采样与自动采样过程.

Development of Optimal Maintenance Policies for Offshore Wind Turbine Gearboxes Based on the Non-homogeneous Continuous-Time Markov Process

Gearbox in offshore wind turbines is a component with the highest failure rates during operation. Analysis of gearbox repair policy that includes economic considerations is important for the effective operation of offshore wind farms. From their initial perfect working states, gearboxes degrade with time, which leads to decreased working efficiency. Thus, offshore wind turbine gearboxes can be considered to be multi-state systems with the various levels of productivity for different working states. To efficiently compute the time-dependent distribution of this multi-state system and analyze its reliability, application of the nonhomogeneous continuous-time Markov process(NHCTMP) is appropriate for this type of object. To determine the relationship between operation time and maintenance cost, many factors must be taken into account, including maintenance processes and vessel requirements. Finally, an optimal repair policy can be formulated based on this relationship.

Toxic Effects of Nano-CuO, Micro-CuO and Cu²⁺on <i>Chlorella</i>sp.

The 96 h acute toxic effects of nano-CuO (N-CuO), micro-CuO (M-CuO) and 2+ on Chlorella sp. were investigated in this paper. The results showed that toxicities decreased in an order of Cu2+>N-CuO>M-CuO. The 96 h EC50 of Cu2+ on Chlorella sp. was 1.06 mg /L, and of N-CuO it was 74.61 mg /L, while no pronounced toxicity was observed when the concentration of M-CuO was lower than 160 mg/L. Further experiments were carried out in order to study the toxicity mechanism of nano-CuO on Chlorella sp.. The results of Cu2+ release from N-CuO showed less than 0.2 mg/L Cu2+ were released, so the release of Cu2+ was not responsible for the toxicity. Further experiments showed N-CuO inhibited formation of Chlorophyll A. Content of Chlorophyll A in the control group was 4.75 mg/108 cells, while it declined to 2.89 mg/108 cells for 160 mg/L N-CuO after 96 h, which indicated that N-CuO could inhibit photosynthesis of Chlorella sp.. Moreover, N-CuO condensed with algal cells. It affected the activity of SOD and POD, indicating that N-CuO could cause oxidant stress to Chlorella sp.. These may be the toxicity mechanism.

Impact of mTOR gene polymorphisms and gene-tea interaction on susceptibility to tuberculosis

BACKGROUND mTOR gene is a key component of the PI3K/Akt/mTOR signaling pathway,and its dysregulation is associated with various diseases.Several studies have demonstrated that tea drinking is a protective factor against tuberculosis(TB).This study was designed to explore five single nucleotide polymorphisms(SNPs)of mTOR in the Han population of China to determine how their interactions with tea drinking affect susceptibility to TB.AIM To investigate if the polymorphisms of mTOR gene and the gene-tea interaction are associated with susceptibility to TB.METHODS In this case-control study,503 patients with TB and 494 healthy controls were enrolled by a stratified sampling method.The cases were newly registered TB patients from the county-level centers for disease control and prevention,and the healthy controls were permanent residents from Xin'ansi Community,Changsha city.Demographic data and environmental exposure information including tea drinking were obtained from the study participants.We genotyped five potentially functional SNP sites(rs2295080,rs2024627,rs1057079,rs12137958,and rs7525957)of mTOR gene and assessed their associations with the risk of TB using logistic regression analysis,and marginal structural linear odds models were used to estimate the gene-environment interactions.RESULTS The frequencies of four SNPs(rs2295080,rs2024627,rs1057079,and rs7525957)were found to be associated with susceptibility to TB(P<0.05).Genotypes GT(OR 1.334),GG(OR 2.224),and GT+GG(OR 1.403)at rs2295080;genotypes CT(OR 1.562)and CT+TT(OR 1.578)at rs2024627,genotypes CT(OR 1.597),CC(OR 2.858),and CT+CC(OR 1.682)at rs1057079;and genotypes CT(OR 1.559)and CT+CC(OR 1.568)at rs7525957 of mTOR gene were significantly more prevalent in TB patients than in healthy controls.The relative excess risk of interaction between the four SNPs(rs2295080,rs2024627,rs1057079,and rs7525957)of mTOR genes and tea drinking were found to be-1.5187(95%CI:-1.9826,-1.0547,P<0.05),-1.8270(95%CI:-2.3587,-1.2952,P<0.05),-2.3246(95%CI:-2.9417,-1.7076,P<0.05)and-0.4235(95%CI:-0.7756,-0.0714,P<0.05),respectively,which suggest negative interactions.CONCLUSION The polymorphisms of mTOR(rs2295080,rs2024627,rs1057079,and rs7525957)are associated with susceptibility to TB,and there is a negative interaction between each of the four SNPs and tea drinking.

Numerical investigations of fully nonlinear water waves generated by moving bottom topography

This paper is concerned with propagation of water waves induced by moving bodies with uniformvelocity on the bottom of a channel, a simple model for prescribed underwater landslides. Thefluid is assumed to be inviscid and incompressible, and the flow, irrotational. We apply this modelto a variety of test problems, and particular attention is paid to long-time dynamics of wavesinduced by two landslide bodies moving with the same speed. We focus on the transcritical regimewhere the linear theory fails to depict the wave phenomena even in the qualitative sense since itpredicts an infinite growth in amplitude. In order to resolve this problem, weakly nonlinear theoryor direct numerical simulations for the fully nonlinear equations is required. Comparing results ofthe linear full-dispersion theory, the linear shallow water equations, the forced Korteweg-de Vriesmodel, and the full Euler equations, we show that water waves generated by prescribedunderwater landslides are characterized by the Froude number, sizes of landslide bodies anddistance between them. Particularly, in the transcritical regime, the second body plays a key role incontrolling the criticality for equal landslide bodies, while for unequal body heights, the higher onecontrols the criticality. The results obtained in the current paper complement numerical studiesbased on the forced Korteweg-de Vries equation and the nonlinear shallow water equations byGrimshaw and Maleewong (J. Fluid Mech. 2015, 2016).

In vitro 3D malignant melanoma model for the evaluation of hypericin-loaded oil-in-water microemulsion in photodynamic therapy

Advances in biomimetic three-dimensional(3D) melanoma models have brought new prospects of drug screening and disease modeling, since their physiological relevancy for recapitulating in vivo tumor architectures is more accurate than traditional two-dimensional(2D) cell culture. Gelatin methacryloyl(GelMA) is widely used as a tissue-engineered scaffold hydrogel for 3D cell culture. In the present study, an in vitro 3D malignant melanoma model based on Gel MA was fabricated to evaluate the efficiency of hypericin(Hy)-loaded microemulsion(ME) in photodynamic therapy against melanoma. The ME was produced by the spontaneous emulsification method to enhance the bioavailability of Hy at tumor sites. Hy-loaded MEs were applied to a 3D malignant melanoma model made using 6% Gel MA and the co-culture of B16F10 and Balb/c 3T3 cells,followed by crosslinking using violet light(403 nm). The observation revealed excellent cell viability and the presence of F-actin cytoskeleton network. Hy-loaded MEs exhibited higher phototoxicity and cell accumulation(about threefold) than free Hy, and the cells cultured in the 3D system displayed lower susceptibility(about 2.5-fold) than those in 2D culture.These findings indicate that the developed MEs are potential delivery carriers for Hy;furthermore, Gel MA hydrogel-based modeling in polydimethylsiloxane(PDMS) molds is a user-friendly and cost-effective in vitro platform to investigate drug penetration and provide a basis for evaluating nanocarrier efficiency for skin cancer and other skin-related diseases.

Fungal community structure analysis of peanut pod rot in soil in Hebei Province,China

In recent years,peanut yield and quality are more seriously affected by pod rot disease in China.However,managing this disease has proven challenging due to the wide host range of its pathogens.In this study,four soil samples were collected from fields with pod rot disease in Hebei Province,and 454 pyrosequencing was used to analyze the fungal communities structure within them.All 38490 ITS high-quality sequences were grouped into 1203 operational taxonomic units,the fungal community diversity of four soil samples was evaluated and compared using Shannon index and Simpson index.The results showed that members of Ascomycota were dominant,followed by Basidiomycota.According to the BLAST results at the species level,Guehomyces had the highest abundance,accounting for about 7.27%,followed by Alternaria,Fusarium,and Davidiella.The relative abundance of Fusarium oxysporum isolated from rotting peanuts in soil with peanut rot was higher than that in the control,indicating that Fusarium oxysporum might be one of the main pathogenic fungus of peanut rot in this area.This study delved into the broader fungal community associated with peanut pod rot,providing a theoretical foundation for preventing and treating this disease in agriculture.

Evaluation of SRAP markers efficiency in genetic diversity of Aspergillus flavus from peanut-cropped soils in China

In order to evaluation the efficiency of SRAP markers on genetic diversity of Aspergillus flavus,we screened out 17sets of primer pairs which could produce clear and reproducible SRAP bands from 150 SRAP primer pairs.The size of SRAP fragments ranged from 120 to 2100 bp.Primer pair Me10/Em9 produced the maximum number of polymorphic bands(12 bands),while Me8/Em13 produced the fewest number of polymorphic bands(only 1).Through analysis genetic diversity ability of different sets of primer pairs,the set of 12 primer pairs was selected for SRAP genetic marker of A.flavus.Cluster analysis was performed based on the genetic similarity coefficients,which ranged from 0.53 to 0.89.A dendrogram assembled using the unweighted pair-group method with arithmetic averages grouped A.flavus samples into 5 main clusters.The results suggested that SRAP marker is a useful molecular technology for the diversity of A.flavus from peanut soils in China.

基于3D受限自组装构筑中空介孔氧化硅/碳复合微球

发展简单、高效、可控的方法来制备中空介孔微球是介孔材料领域的研究热点.本工作结合嵌段共聚物的三维受限自组装(3D-CSA)和自模板碳化策略,建立了一种构筑中空介孔微球的新方法.首先,采用乳液-溶剂挥发法实现嵌段共聚物与全氟辛烷(PFO)在3D受限空间的分级组装,获得了核-壳结构微球,其中壳层由微相分离的嵌段共聚物构成.然后,在壳层的连续相选择性地复合氧化硅,既实现了无机框架的负载,又实现了对连续相聚合物链选择性交联.对复合微球进行煅烧处理后,实现了壳层连续相聚合物的选择性碳化,获得了中空介孔氧化硅/碳复合微球.本研究系统地阐述了核-壳型分级结构微球的形成机理和必备条件,研究了氧化硅前驱体添加量和嵌段共聚物分子量对中空介孔氧化硅/碳复合微球形貌的影响,为制备中空介孔微球材料提供了一种简便、可控的方法.

Prognostic Analysis and an Appropriate Antiplatelet Strategy for Patients With Percutaneous Coronary Intervention and High Bleeding Risk:Rationale and Protocol for a MultiCenter Cohort Study

Percutaneous coronary intervention(PCI)is an important treatment strategy for patients with coronary artery disease.However,bleeding after PCI significantly increases the mortality risk.The search for prognostic predictors and optimal antiplatelet therapy for patients with high bleeding risk(HBR)after PCI has been a much researched upon topic in current cardiovascular research.However,there is no widely accepted prognostic model or recommended antiplatelet therapy for patients with PCI-HBR.In this trial,based on prospective multi-center database building,we will analyze the adverse prognostic predictors for patients with PCI-HBR,observe the types of antiplatelet drugs and duration of dual antiplatelet therapy in PCI-HBR patients,and compare the safety and feasibility of different antiplatelet regimens and treatment courses.The prognostic analysis and an appropriate antiplatelet strategy for patients with PCI and high bleeding risk(PPP-PCI)trial will help analyze bleeding risk factors in PCI-HBR patients and explore the appropriate antiplatelet treatment options.This study is registered with ClinicalTrials.gov(NCT05369442).The Research Ethics Committee of West China Hospital authorized this study(2022 Review#269).The trial results will be published in peer-reviewed journals and at conferences.

Review and Outlook of HVDC Grids as Backbone of Transmission System

HVDC technology has undergone many major developments in the past decades,resulting in higher power ratings,increased efficiency,and the availability of effective means for HVDC grid protection.These developments have made overlay HVDC grids a viable option to shift towards a carbon-free power system,by enabling optimal use of renewable resources.In particular,overlay HVDC grids greatly increase the prospect of building(trans-)continental supergrids to facilitate global economic development.However,overlay HVDC grids still encounter challenges due to the distance and amount of power involved.This paper focuses on analyzing the readiness of the current technologies and the challenges associated with overlay HVDC grids.An in-depth analysis is carried out to evaluate the applicability of current technologies for overlay HVDC grids.Based on the review of recent research and development efforts,the gaps and challenges towards the realization of a global HVDC grid are summarized.

Frequency domain based DC fault analysis for bipolar HVDC grids

This paper proposes a frequency domain based methodology to analyse the influence of High Voltage Direct Current(HVDC) configurations and system parameters on the travelling wave behaviour during a DC fault. The method allows us to gain deeper understanding of these influencing parameters. In the literature, the majority of DC protection algorithms essentially use thefirst travelling waves initiated by a DC fault for fault discrimination due to the stringent time constraint in DC grid protection. However, most protection algorithms up to now have been designed based on extensive time domain simulations using one specific test system. Therefore, general applicability or adaptability to different configurations and system changes is not by default ensured, and it is difficult to gain in-depth understanding of the influencing parameters through time domain simulations. In order to analyse the first travelling wave for meshed HVDC grids, voltage and current wave transfer functions with respect to the incident voltage wave are derived adopting Laplace domain based component models. The step responses obtained from the voltage transfer functions are validated by comparison against simulations using a detailed model implemented in PSCADTM. Then, the influences of system parameters such as the number of parallel branches, HVDC grid configurations and groundings on the first travelling wave are investigated by analysing the voltage and current transfer functions.

Dispersion-less Kerr solitons in spectrally confined optical cavities

Solitons are self-reinforcing localized wave packets that manifest in the major areas of nonlinear science,from optics to biology and Bose-Einstein condensates.Recently,optically driven dissipative solitons have attracted great attention for the implementation of the chip-scale frequency combs that are decisive for communications,spectroscopy,neural computing,and quantum information processing.In the current understanding,the generation of temporal solitons involves the chromatic dispersion as a key enabling physical effect,acting either globally or locally on the cavity dynamics in a decisive way.Here,we report on a novel class of solitons,both theoretically and experimentally,which builds up in spectrally confined optical cavities when dispersion is practically absent,both globally and locally.Precisely,the interplay between the Kerr nonlinearity and spectral filtering results in an infiinite hierarchy of eigenfunctions which,combined with optical gain,allow for the generation of stable dispersion-less dissipative solitons in a previously unexplored regime.When the filter order tends to infinity,we find an unexpected link between dissipative and conservative solitons,in the form of Nyquist-pulse-like solitons endowed with an ultra-flat spectrum.In contrast to the conventional dispersion-enabled nonlinear Schr?dinger solitons,these dispersion-less Nyquist solitons build on a fully confined spectrum and their energy scaling is not constrained by the pulse duration.Dispersion-less soliton molecules and their deterministic transitioning to single solitons are also evidenced.These findings broaden the fundamental scope of the dissipative soliton paradigm and open new avenues for generating soliton pulses and frequency combs endowed with unprecedented temporal and spectral features.

Vascular reconstruction of segmental intestinal grafts using autologous internal iliac vessels

Background The aim of this study was to assess whether the autologous internal iliac artery and vein could be used as an interpositional graft for vascular reconstruction in segmental intestinal allografts and autografts.Methods Thirty-four intestinal transplants(19 living-related allografts and 15 autografts)were conducted in our programs between January 2011 and January 2019.Patient characteristics,type of vascular reconstruction,and post-operative complications were reviewed.Results There were 20 males and 14 females with a median age of 35 years.Of 34 grafts,22(64.7%)(11 allografts and 11 autografts)were revascularized using the autologous internal iliac artery and vein for reconstruction.Vascular reconstruction on the back table took 2166min to complete.Both total operative time and cold ischemia time tended to be longer in the vascular-reconstruction group than in the direct-anastomosis group(5306226 vs 4406116 and 159649 vs 125666 min,respectively),but these differences were not significant.The incidence of vascular thrombosis tended to be higher in the direct-anastomosis group than in the vascular-reconstruction group(16.7%vs 0%,P=0.118).At a median follow-up of 36.9 months,no stenosis or pseudoaneurysms developed.In 19 allografts,acute rejection occurred in 4(21.1%)and chronic rejection occurred in 1(5.2%).Conclusions Our results indicate that the use of an autologous internal iliac interposition graft greatly facilitates intestinal graft implantation and minimizes the risk of vascular complications.

Asymmetric Mesoporous Carbon Microparticles by 3D-Confined Self-Assembly of Block Copolymer/Homopolymer Blends and Selective Carbonization

Shape control of mesoporous carbon microparticles(MCMPs)is of critical importance;in particular,asymmetric shapes that can yield unique properties have attracted significant attention.However,the tailored synthesis of asymmetric MCMPs with ordered structures remains challenging.Herein,we report a facile route to prepare asymmetric MCMPs by dynamic neutral interface-guided 3D-confined self-assembly(3D-CSA)of block copolymer/homopolymer(BCP/hP)blends,followed by a self-templated selective direct carbonization strategy.BCP/h P Janus microparticles with ordered hierarchical mesostructures were prepared with emulsion solvent evaporation-induced 3D-CSA.The continuous phase of BCP domains was then crosslinked.Composite asymmetric MCMPs are successfully generated after selective carbonization of the crosslinked continuous phase.This method allows tuning the shape of MCMPs easily by varying the blending ratio of BCP/h P.The composite asymmetric MCMPs combine the advantages of asymmetric shape,ordered structure,high specific surface area,chemical inertness and thermal stability and could provide great possibilities for applications in catalysis,drug delivery,energy conversion and storage.

Preparation of polyacrylamide/silica composite capsules by inverse Pickering emulsion polymerization

Polyacrylamide/silica （PAM/SiO2） composite capsules were synthesized by inverse Pickering emulsion polymerization. Silica nanoparticles modified with methacryloxypropyltrimethoxysilane （MPS） were used as a stabilizer. Transmission electron microscopy （TEM）, scanning electron microscopy （SEM）. Fourier transform infrared （FTIR） spectroscopy, and thermal gravimetric analysis （TGA） were used to characterize the morphology and composition of the composite capsules. SEM and TEM images showed that capsules consisted of a particle shell and a polymer inner layer. The capsule size depends on the nanoparticle concentration in the continuous phase. The composite rigidity largely depends on the acrylamide concentration. FTIR and TGA results indicated the existence of polyacrylamide and SiO2 in the composite particles. Aqueous Hg（ll） removal testing by the PAM/SiO2 composite capsules indicated promising potential for removing heavy metal ions from wastewater.

Advances in coastal ocean boundary layer detection technology and equipment in China

Accurate and comprehensive knowledge of the atmospheric environment and its evolution within the coastal ocean boundary layer are necessary for understanding the sources,chemical mechanisms,and transport processes of air pollution in land,sea,and atmosphere.We present an overview of coastal ocean boundary layer detection technology and equipment in China and summarize the progress and main achievements in recent years.China has developed a series of coastal ocean boundary layer detection technologies,including Light Detection and Ranging(LIDAR),turbulent exchange analyzer,air-sea flux analyzer,stereoscopic remote sensing of air pollutants,and oceanic aerosol detection equipment to address the technical bottleneck caused by harsh environmental conditions in coastal ocean regions.Advances in these technologies and equipment have provided scientific assistance for addressing air pollution issues and understanding land-sea-atmosphere interactions over coastal ocean regions in China.In the future,routine atmospheric observations should cover the coastal ocean boundary layer of China.

Impact of serum uric acid on left ventricular diastolic function in patients with autoimmune diseases

To the Editor:Left ventricular diastolic dysfunction(LVDD)is an unrecognized subclinical presentation of autoimmune diseases(AD)andcarries a worse prognosis.Elevated serum uric acid(SUA),as a_proinflammatory factor,is associatedwithchanges in cardiacfunction in the general population as,well as in those with cardiac diseases.

High-density lipoprotein regulates angiogenesis by long non-coding RNA HDRACA

Normal high-density lipoprotein(nHDL)can induce angiogenesis in healthy individuals.However,HDL from patients with coronary artery disease undergoes various modifications,becomes dysfunctional(dHDL),and loses its ability to promote angiogenesis.Here,we identified a long non-coding RNA,HDRACA,that is involved in the regulation of angiogenesis by HDL.In this study,we showed that nHDL downregulates the expression of HDRACA in endothelial cells by activating WW domain-containing E3 ubiquitin protein ligase 2,which catalyzes the ubiquitination and subsequent degradation of its transcription factor,Kruppel-like factor 5,via sphingosine 1-phosphate(S1P)receptor 1.In contrast,dHDL with lower levels of S1P than nHDL were much less effective in decreasing the expression of HDRACA.HDRACA was able to bind to Ras-interacting protein 1(RAIN)to hinder the interaction between RAIN and vigilin,which led to an increase in the binding between the vigilin protein and proliferating cell nuclear antigen(PCNA)mRNA,resulting in a decrease in the expression of PCNA and inhibition of angiogenesis.The expression of human HDRACA in a hindlimb ischemia mouse model inhibited the recovery of angiogenesis.Taken together,these findings suggest that HDRACA is involved in the HDL regulation of angiogenesis,which nHDL inhibits the expression of HDRACA to induce angiogenesis,and that dHDL is much less effective in inhibiting HDRACA expression,which provides an explanation for the decreased ability of dHDL to stimulate angiogenesis.