Across two phylogeographic breaks: Quaternary evolutionary history of a mountain aspen (Populus rotundifolia) in the Hengduan Mountains

Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both.Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia,a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China.Demographic and migration hypotheses were tested using coalescent-based approaches.Limited historical gene flow was observed between the western and eastern groups of P.rotundifolia,but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line,manifesting in clear admixture and high genetic diversity in the central group.Wind-borne pollen and seeds may have facilitated the dispersal of P.rotundifolia following prevalent northwest winds in the spring.We also found that the Hengduan Mountains,where multiple genetic barriers were detected,acted on the whole as a barrier between the western and eastern groups of P.rotundifolia.Ecological niche modeling suggested that P.rotundifolia has undergone range expansion since the last glacial maximum,and demographic reconstruction indicated an earlier population expansion around 600 Ka.The phylogeographic pattern of P.rotundifolia reflects the interplay of biological traits,wind patterns,barriers,niche differentiation,and Quaternary climate history.This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.

Conservation genomic investigation of an endangered conifer,Thuja sutchuenensis,reveals low genetic diversity but also low genetic load

Endangered species generally have small populations with low genetic diversity and a high genetic load.Thuja sutchuenensis is an endangered conifer endemic to southwestern China.It was once considered extinct in the wild,but in 1999 was rediscovered.However,little is known about its genetic load.We collected 67 individuals from five wild,isolated T.sutchuenensis populations,and used 636,151 SNPs to analyze the level of genetic diversity and genetic load in T.sutchuenensis to delineate the conservation units of T.sutchuenensis,based on whole transcriptome sequencing data,as well as target capture sequencing data.We found that populations of T.sutchuenensis could be divided into three groups.These groups had low levels genetic diversity and were moderately genetically differentiated.Our findings also indicate that T.sutchuenensis suffered two severe bottlenecks around the Last Glaciation Period and Last Glacial Maximum.Among Thuja species,T.sutchuenensis presented the lowest genetic load and hence might have purged deleterious mutations efficiently through purifying selection.However,distribution of fitness effects analysis indicated a high extinction risk for T.sutchuenensis.Multiple lines of evidence identified three management units for T.sutchuenensis.Although T.sutchuenensis possesses a low genetic load,low genetic diversity,suboptimal fitness,and anthropogenic pressures all present an extinction risk for this rare conifer.This might also hold true for many endangered plant species in the mountains all over the world.

Lewis acid-doped transition metal dichalcogenides for ultraviolet–visible photodetectors

Ultraviolet photodetectors(UV PDs)are widely used in civilian,scientific,and military fields due to their high sensitivity and low false alarm rates.We present a temperature-dependent Lewis acid p-type doping method for transition metal dichalcogenides(TMDs),which can effectively be used to extend the optical response range.The p-type doping based on surface charge transfer involves the chemical adsorption of the Lewis acid SnCl_(4)as a light absorption layer on the surface of WS_(2),significantly enhancing its UV photodetection performance.Under 365 nm laser irradiation,WS_(2)PDs exhibit response speed of 24 ms/20 ms,responsivity of 660 mA/W,detectivity of 3.3×10^(11)Jones,and external quantum efficiency of 226%.Moreover,we successfully apply this doping method to other TMDs materials(such as MoS_(2),MoSe_(2),and WSe_(2))and fabricate WS_(2) lateral p–n heterojunction PDs.

The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Spatiotemporal transformable nano-assembly for on-demand drug delivery to enhance anti-tumor immunotherapy

Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a cancer-associated fibroblasts(CAFs)triggered structure-transformable nano-assembly(HSD-P@V),which can directionally deliver valsartan(Val,CAFs regulator)and doxorubicin(DOX,senescence inducer)to the specific targets.In detail,DOX is conjugated with hyaluronic acid(HA)via diselenide bonds(Se-Se)to form HSD micelles,while CAFs-sensitive peptide is grafted onto the HSD to form a hydrophilic polymer,which is coated on Val nanocrystals(VNs)surface for improving the stability and achieving responsive release.Once arriving at tumor microenvironment and touching CAFs,HSD-P@V disintegrates into VNs and HSD micelles due to sensitive peptide detachment.VNs can degrade the extracellularmatrix,leading to the enhanced penetration of HSD.HSD targets tumor cells,releases DOX to induce senescence,and recruits effector immune cells.Furthermore,senescent cells are cleared by the recruited immune cells to finish the integrated anti-tumor therapy.In vitro and in vivo results show that the nanoassembly remarkably inhibits tumor growth as well as lungmetastasis,and extends tumorbearing mice survival.This work provides a promising paradigm of programmed delivering multi-site nanomedicine for cancer immunotherapy.

基于MicroBlaze与FPGA的高可靠性嵌入式系统设计

随着FPGA的快速发展,基于MicroBlaze与FPGA架构设计的嵌入式系统由于其空间尺寸优势得到广泛引用。为提高系统可靠性,通过FPGA设计看门狗电路监测MicroBlaze软核处理器运行情况。若处理器运行异常,则将处理器复位,此时程序从入口代码重新运行。在上述过程中,系统完成重启的前提是软核入口代码数据正确,若处理器运行异常且将入口代码数据篡改,此时系统将无法正常重启。为解决该问题,设计了基于MicroBlaze与FPGA的高可靠性嵌入式系统,通过加载保护设计方式,保证嵌入式系统在该故障下仍能够进行重启。

烟草漂浮秧盘自动移栽机的设计与试验

针对烟草钵苗手动或半自动移栽过程中存在的种植密度低,人力成本高,生产效益低等问题,设计了一种双向对称自动取苗装置和与之配套的送盘装置,以现有手动投苗自走式移栽机底盘为基础,组装样机进行了试验。试验结果证明,采用双向对称布置的自动取苗方案,左右两组对称交错取苗能有效提高取苗效率和移栽速度;采用级进式逐行抓取钵苗的方式,克服了烟草漂浮硬质秧盘自动取苗的空间受限问题;采用零位传感步进电机控制的自动取苗系统,可将单行取投苗误差控制在4 mm以内,单行平均误差为1.79 mm,当气动回路的压力达到0.38 Mpa时,夹持拔苗的成功率能达到100%,可满足作业需求。

Integrity and Failure Analysis of Cement Sheath Subjected to Coalbed Methane Fracturing

Perforation and fracturing are typically associated with the development of coalbed methane wells.As the cement sheath is prone to failure during this process,in this work,the effects of the casing pressure,elastic modulus of the cement,elastic modulus of the formation,and casing eccentricity on the resulting stresses are analyzed in the frame of a finite element method.Subsequently,sensitivity response curves of the cement sheath stress are plotted by normalizing all factors.The results show that the maximum circumferential stress and Mises stress of the cement sheath increase with the casing internal pressure,elastic modulus of the cement and casing eccentricity.As the elastic modulus of the formation increases,the maximum circumferential stress of the cement sheath decreases,and its maximum Mises stress increases slightly.The cement sheath undergoes tensile failure during coalbed methane fracturing.The stress sensitivity of the cement sheath to the influential parameters is in the following order:casing internal pressure>elastic modulus of cement sheath>casing eccentricity>elastic modulus of formation.

Vericiguat treatment of heart failure: A systematic review and metaanalysis

BACKGROUND Heart failure(HF),an end-stage manifestation of various cardiac diseases,poses an enormous economic and health burden on society.Vericiguat may be an effective drug in the treatment of HF.AIM To explore by meta-analysis the efficacy and safety of Vericiguat in treating chronic heart failure.METHODS Databases,including PubMed,EMBASE,Web of Science,and Cochrane Library,were searched to collect all published randomized controlled trials(RCTs)on Vericiguat treatment of chronic heart failure from the earliest electronic records to those published in March 2023.Two investigators independently screened the literature according to inclusion and exclusion criteria,evaluated the quality of the studies,and extracted valid data before conducting a meta-analysis using RevMan5.4.RESULTS Four RCTs with 5919 patients were included,and the meta-analysis showed that treatment with 10 mg Vericiguat reduced the incidence of the primary endpoint(a composite of cardiovascular mortality and first heart-failure-related hospital-ization)in patients with chronic heart failure compared to placebo[relative risk(RR)=0.91,95%confidence interval(CI):0.85–0.98,P=0.01],and reduced the incidence of heart-failure-related hospitalization(RR=0.92,95%CI:0.84–1.00,P=0.05).However,for the incidence of cardiovascular and all-cause death,there were no significant differences between the Vericiguat and placebo groups.In addition,the two groups did not show significant differences in blood pressure,heart rate,and Kansas Cardiomyopathy Questionnaire physical limitation score.In terms of safety,10 mg Vericiguat did not increase the risk of adverse effects in patients with chronic heart failure.Vericiguat may increase the risk of symp-tomatic hypotension(RR=1.17,95%CI:0.98–1.39,P=0.08)and syncope(RR=1.18,95%CI:0.90–1.55,P=0.24),but not significantly.CONCLUSION Vericiguat(10 mg)was more effective than placebo in treating patients with chronic heart failure and had a better safety profile.

Progress of Geodesy Related Ionosphere from Chinese Scientists in the Period of 2019—2023

The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significantly,such as the Global Navigation Satellite System(GNSS).Meanwhile,the GNSS is also an essential technique for sensing the variation of ionosphere.During the years of 2019—2023,a large number of Chinese geodesy scientists devoted much efforts to the geodesy related ionosphere.Due to the very limited length,the achievements are carried out from the following six aspects,including:①The ionospheric correction models for BDS and BDSBAS;②Real-time global ionospheric monitoring and modeling;③The ionospheric 2D and 3D modeling based on GNSS and LEO satellites;④The ionospheric prediction based on artificial intelligence;⑤The monitoring and mitigation of ionospheric disturbances for GNSS users;⑥The ionospheric related data products and classical applications.

丙乳砂浆修复技术在水闸除险加固中的应用

水工建筑物经过多年的运行,混凝土表面都会存在不同程度的碳化情况,文章结合工程实际介绍了丙乳砂浆在某水闸闸墩除险加固的应用过程,从相关技术参数、施工工艺以及质量控制等方面对丙乳砂浆修复技术进行总结。水闸闸墩经丙乳砂浆修复处理后效果良好,该修复技术及相关处理措施可应用于水工建筑物混凝土表面的碳化处理。

脑室腹腔分流术后脑积水患者再次行神经内镜下三脑室底造瘘的疗效评价

目的评价脑室腹腔分流术后患者行神经内镜下三脑室底造瘘(ETV)治疗梗阻性脑积水的临床效果。方法回顾性分析2010年6月-2016年10月该科行三脑室底造瘘的102例梗阻性脑积水患者。其中,男63例,女39例,年龄11～54岁,平均32.6岁。依据既往是否行过脑室腹腔分流手术分为两组,首次ETV组75例,分流术后ETV组(脑室腹腔分流术后引流管堵塞或引流管外露的梗阻性脑积水患者)27例,首次ETV组直接行ETV,分流术后ETV组行神经内镜辅助下脑室腹腔分流管拔除及第三脑室底造瘘术治疗。术后门诊随访并评价手术治疗效果及并发症发生率。结果 102例患者均获随访,随访时间3～24个月,平均11.3个月,对于术前症状首次ETV组与分流术后ETV组均能得到改善,术后并发症(硬膜下积液、发热和颅内感染)发生率的比较,差异无统计学意义(P>0.05),近期疗效两组差异无统计学意义(P>0.05),远期疗效两组差异具有统计学意义(P <0.05),且首次ETV组疗效均优于分流术后ETV组,分流术后ETV治疗组比首次ETV组具有更高的症状复发率和再手术率(P <0.05)。结论对于梗阻性脑积水患者行ETV后症状改善明显,失败率相对较低。对于梗阻性脑积水若既往接受过分流手术,再次行ETV仍有部分患者能得到较好疗效,但术后症状复发风险更高,需再次手术可能性较大。

Dynamics Analysis of an Aquatic Ecological Model with Temperature Effect

Under the control framework of algae bloom in eutrophic lakes and reservoirs based on biological manipulation, the temperature variable is introduced into ecological modeling to show that it is a necessary condition for the rapid occurrence of algal blooms, and an aquatic ecological model with temperature effect is proposed to describe dynamic relationship between algae and biological manipulation predator. The mathematical theory work mainly investigates the existence and stability of some equilibrium points and some critical conditions for the occurrence of transcritical bifurcation and Hopf bifurcation. The numerical simulation mainly shows the dynamic evolution process of bifurcation dynamics, which can not only verify the validity and feasibility of these theoretical works but also analyze the influence of some key parameters on dynamic behavior evolution. Furthermore, It is worth emphasizing that temperature plays an important role in the coexistence of algae and biological manipulation predators. Moreover, the coexistence mode of algae and biological manipulation predators is discovered by means of dynamic bifurcation evolution. Finally, it is hoped that these research results can provide some reference for the study of aquatic ecosystems.

公路边坡智慧养护系统构架设计研究

为长期科学跟踪边坡养护数据信息,支撑养护决策,本文搭建了公路边坡智慧养护系统构架,它主要包括边坡基本信息、排查信息、专项治理、养护评定与决策四部分,建立了一套从发现隐患—分析隐患—处治隐患的可追踪全过程化工业级管理流程,并通过权限设置考虑了不同业务部门的需求,有效地提高了系统的可操作性,通过在贵阳市环城高速公路沿线200余段边坡工点的应用情况来看,效果良好。

基于压缩感知的心脏磁共振快速成像的应用现状与发展趋势

为了改善心脏磁共振成像(Cardiac Magnetic Resonance,CMR)在实际应用中成像时间长且存在运动伪影等不足,将压缩感知理论(Compressed Sensing,CS)引入其中,充分利用K空间信息冗余的特性,实现由部分K空间数据重构心脏组织影像,在减少伪影、保证精度的同时加快成像速度。结合近3年的国内外文献,首先对CMR现状、常用序列和技术以及采样模式、压缩感知理论框架分别进行阐述;其次对CMR的最新成果及应用现状进行综述和概括;然后介绍压缩感知图像重构的相关定量评价指标,给出作者在CS-CMR图像重构方面的研究进展;最后总结当前研究中的不足,并展望未来的发展方向。

基于图像序列差分正则项的实时心脏磁共振重构

目的使用压缩感知(CS)加快心脏磁共振(CMR)图像的扫描速度的可行性和价值。材料与方法提出基于图像序列差分正则项的实时CMR图像重构算法,以第1帧图像作为参考图像,从K空间数据重构出第1帧图像后,利用图像序列差分正则化使得后续帧的重构均以第1帧图像为参考,从而同时利用时间域和空间域的稀疏性。采用改进的NESTA算法对模型进行求解,提高算法的实时性。以峰值信噪比(PSNR)、相对误差(RLNE)、均方根误差(RMSE)为定量评价指标,对比本研究算法与kt FOCUSS、基于运动补偿的kt FOCUSS、kt SLR、DTV等主流算法的性能差异。结果与上述其他主流算法相比,本研究算法可以获得最佳定量评价指标,表现在PSNR高0.46～4.86 dB,RLNE低0.002～0.080,RMSE低0.0004～0.0050;同时,本研究算法在人眼视觉感受、局部区域放大和沿时间轴展开等定性分析中也取得最佳效果。结论本研究算法在客观指标定量评价上明显优于其他对比算法,同时在人眼视觉感受等主观定性评价上也取得最佳效果。

固化海积淤泥土强度发展规律试验研究

浙东沿海地区广泛分布吹填淤泥土,为解决真空预压难以快速提高淤泥土地基承载力的问题,提出使用固化剂加固沿海地区海积淤泥地基的方法,对含水率不低于85%的吹填土进行固化试验,比较了固化剂的种类、掺量及费用,分析了固化土强度发展规律。结果表明,3%石灰-8%粉煤灰类固化土对高含水率海积淤泥的固化效果较为明显,且方案最优,强度费用比为4.2,并得到了固化淤泥土的无侧限抗压强度与龄期之间的对数关系,28d内强度增长较快,确定该类固化土后期外掺剂试验以28d强度为主要参考点。研究成果可为海积淤泥土地基的加固提供试验数据支撑。

跨尺度精密运动压电平台和快速驱动方法研究

该文提出了一种基于惯性粘滑驱动原理、可快速运动的跨尺度精密运动压电平台。该平台由滑动部分、摩擦调整部分、堆叠压电陶瓷、惯性部分和底座组成,总尺寸为60 mm×60 mm×58 mm。该文详细介绍了基于此结构的新型惯性粘滑驱动原理。为了研究所设计压电平台的驱动性能,制作了样机并建立了实验系统。实验中,驱动频率7 kHz时最大的单步步距为2.67μm,最大速度为22.7 mm/s,最大静态保持力为36 N。实验结果表明,该文设计的平台可快速运动,具有良好的运动性能。

Sequential multi-objective optimization of thin-walled aluminum alloy tube bending under various uncertainties

Combining the design of experiments(DOE)and three-dimensional finite element(3D-FE)method,a sequential multiobjectiveoptimization of larger diameter thin-walled(LDTW)Al-alloy tube bending under uncertainties was proposed andimplemented based on the deterministic design results.Via the fractional factorial design,the significant noise factors are obtained,viz,variations of tube properties,fluctuations of tube geometries and friction.Using the virtual Taguchi’s DOE of inner and outerarrays,considering three major defects,the robust optimization of LDTW Al-alloy tube bending is achieved and validated.For thebending tools,the robust design of mandrel diameter was conducted under the fluctuations of tube properties,friction and tubegeometry.For the processing parameters,considering the variations of friction,material properties and manufacture deviation ofmandrel,the robust design of mandrel extension length and boosting ratio is realized.

七鳃鳗胆道闭锁过程中胆汁酸耐受机制研究进展

胆道闭锁(biliaryatresia,BA)是一种罕见的婴幼儿肝胆疾病,其特征是纤维硬化性胆管病变,导致肝外胆管和肝内胆管阻塞或闭塞,胆汁不能向肠道排泄,胆汁酸对肝实质细胞造成严重损伤,最后导致肝硬化和肝衰竭危及生命。目前,胆道闭锁的发病机理尚不明确,临床上普遍采用"先葛西"、"后移植"的序贯性治疗方式。葛西手术(Kasai)通过建立胆汁引流通道从而延长患儿自体肝生存时间,但随着门静脉高压和原发性胆管炎等并发症的出现,最后患者仍需要肝移植来挽救生命。七鳃鳗(lamprey)是唯一在生长发育过程中胆管能够自发消失的脊椎动物,在幼体期七鳃鳗具有完整的胆道系统,但在变态过程中,七鳃鳗表现出发育性胆道闭锁,胆管及胆囊逐渐退化直至整个胆道系统完全丧失,同时肝细胞发生重排和精细结构改变。研究发现,七鳃鳗可以在变态发育过程中形成胆道闭锁症状时维持血浆正常的胆汁酸水平,从而不会发生肝硬化和肝衰竭,适应性地在胆道闭锁和胆汁淤积症中存活。为探究七鳃鳗胆汁酸耐受在胆道闭锁疾病中的应用,本文对近年来七鳃鳗发生胆道闭锁而产生对胆汁酸耐受机制的相关研究进展进行了总结,以期为人类胆道闭锁疾病的诊断和治疗提供参考。