基于高分辨率遥感影像和改进U-Net模型的滑坡提取——以汶川地区为例

滑坡快速识别检测可以满足滑坡灾害的高时效性要求,对灾害损失评估和灾后救援具有重要意义。研究提出一种基于深度学习的滑坡自动提取方法提高滑坡检测的精度。该方法使用目标区遥感影像、数字高程模型数据和面向对象多特征变化向量分析法(robust change vector analysis,RCVA)提取的变化特征作为模型输入,设计结合密集上采样和非对称卷积的U-Net模型提高滑坡识别精度。以四川省汶川地区作为研究区,设计试验测试了不同数据组合和不同方法得到的像素级滑坡分割精度,结果表明该研究提出的改进的U-Net模型可以取得更好的分割结果。

Effects of different doses of glucose and fructose on central metabolic pathways and intercellular wireless communication networks in humans

Fructose and glucose are often widely used in food processing and may contribute to many metabolic diseases.To observe the effects of different doses of glucose and fructose on human metabolism and cellular communication,volunteers were given low,medium,and high doses of glucose and fructose.Serum cytokines,glucose,lactate,nicotinamide adenine dinucleotide(NADH)and metabolic enzymes were assayed,and central carbon metabolic pathway networks and cytokine communication networks were constructed.The results showed that the glucose and fructose groups basically maintained the trend of decreasing catabolism and increasing anabolism with increasing dose.Compared with glucose,low-dose fructose decreased catabolism and increased anabolism,significantly enhanced the expression of the inflammatory cytokine interferon-γ(IFN-γ),macrophage-derived chemokine(MDC),induced protein-10(IP-10),and eotaxin,and significantly reduced the activity of isocitrate dehydrogenase(ICDH)and pyruvate dehydrogenase complexes(PDHC).Both medium and high doses of fructose increase catabolism and anabolism,and there are more cytokines and enzymes with significant changes.Furthermore,multiple cytokines and enzymes show strong relevance to metabolic regulation by altering the transcription and expression of enzymes in central carbon metabolic pathways.Therefore,excessive intake of fructose should be reduced to avoid excessive inflammatory responses,allergic reactions and autoimmune diseases.

结肠镜术前应用西甲硅油的效果分析

目的探讨结肠镜检查术前应用西甲硅油联合复方聚乙二醇电解质散的临床价值。方法选取2013年10月-2015年12月于该院行结肠镜检查术的患者106例,随机分为观察组与对照组,每组各53例。对照组患者术前单纯口服复方聚乙二醇电解质散,观察组患者则联合使用西甲硅油和复方聚乙二醇电解质散。分别记录两组患者的术前肠道准备评分、病变检出情况以及患者各项肝肾功能和电解质变化。结果观察组患者术前肠道准备满意率高于对照组患者(P<0.05),且病变检出率也高于对照组(P<0.05)。两组患者检查过程中均无明显不良反应。结论西甲硅油可以祛除肠道气泡,与复方聚乙二醇电解质散联合应用于结肠镜检查术前,可显著提升肠道清洁效果,改善结肠镜图像,提高病变检出率。

基于时间序列InSAR技术的川东红层滑坡识别及变形规律

针对川东红层滑坡典型易发区域,采用小基线集( SBAS)时间序列的 InSAR( interferometry synthetic aperture radar)方法进行了解译,并采用 Google Earth 可视化展示,有效圈定并复核了潜在隐患区域。提取了采矿引起斜坡失稳及牛马场滑坡的变形位移曲线,揭示了其变形规律。研究结果表明:解译区滑坡基本都发育在形变速率较大的黄色欠稳定和红色不稳定区域,区域形变位移值大小与滑坡发育比例成正比关系,35%的解译面积滑坡发育比率可以达到 70%以上。同时通过野外调查发现 4 个潜在不稳定隐患斜坡,极大地提高了红层滑坡的早期识别能力。InSAR解译显示研究区西北区由采矿引起的斜坡失稳,与干涉图上的条纹位置对应较为一致,形变位移最大能达到视线向 20 mm/a;牛马场滑坡范围均为垂直形变速率较大的黄色和红色解译点,变形位移曲线显示滑坡发生前已经处于蠕变变形阶段,累计变形量可以达到 500 mm 左右。

基于PFC2D的缓倾顺层滑移-溃曲型岩质滑坡破坏机制分析

川东红层地区岩层倾角通常较缓,在缓倾顺向斜坡上出现了一种较为特殊的滑移-溃屈变形破坏形式。相对于缓倾岩层的顺层滑移,其破坏、受力和变形显得较为复杂。本文在分析兴浪坡滑坡变形模式的基础上,基于PFC2D软件对其进行破坏过程及微观力学分析。结果显示:受川东宽缓褶皱影响滑坡所处地形呈上陡下缓的特点,岩层变缓和老滑坡堆积造成的应力集中是斜坡发生滑移-溃曲的原因。变形破坏模式解析其分为滑移-弯曲鼓胀、强烈弯曲-隆起和滑移-溃屈破坏3个阶段。模型破坏云图位移显示滑坡中部监测点2位置存在应力集中导致的岩体错断和剪断特征,与实际调查相符合。滑坡中部溃曲处在滑动前主要表现为压应力集中,当应力集中到一定程度,岩体沿着层面或破碎带剪切贯通,形成滑移-弯曲-溃曲变形模式。研究结果对于其他类似边坡的稳定性评价和识别具有参考意义。

川东巴中市恩阳区近水平土质滑坡破坏模式及专业监测预警

巴中市恩阳区属于典型川东北红层区域,近几年大量的人类工程活动及强降雨极易诱发浅表层土质滑坡,对人民的生命财产造成威胁。本文通过对巴中市恩阳区近3年(2020—2022年)新增的25处近水平土质滑坡进行统计分析,建立了区域典型的土质滑坡地质模型:此类近水平土质滑坡的基本特征为岩层倾角和地形坡度均在10°以内(多为3°~5°),呈近水平状,滑体土层厚度前缘薄,后缘厚,且滑坡前缘存在高陡临空面,岩、土分界面明显。在此基础上定性分析了此类滑坡的变形破坏模式:前缘滑移-拉裂,次级剪切滑动,逐级牵引滑移,整体滑动变形。选择区内一处典型的近水平土质滑坡为研究对象,以滑坡前缘和中后部地表位移为主要监测对象,并监测降雨强度,通过GNSS地表位移监测站、裂缝位移计、雨量计等监测设备对滑坡开展专业监测,监测数据表明,近水平土质滑坡的实际变形破坏模式与理论分析结论基本一致。本文的研究结论可为区内同类型滑坡在设计专业监测方案,制定精准防灾避险措施时,提供一定的理论支撑。

利用CRISPR/Cas9 AAV系统构建纹状体Slc20a2基因敲除小鼠模型

原发性家族性脑钙化症(primary familial brain calcification,PFBC)是慢性进展性的神经系统遗传病,临床症状主要包括运动障碍、认知障碍及精神障碍等,其致病机制尚未完全明确。研究表明SLC20A2是该病最主要的致病基因。由于Slc20a2基因全身性敲除小鼠模型会导致胎儿生长受限,为更好地研究PFBC发病机制,本研究应用CRISPR/Cas9技术构建了纹状体Slc20a2基因条件性敲除小鼠模型。首先,针对Slc20a2基因编码区,设计3条靶向exon3的sgRNA(single guide RNA),通过构建质粒、转染细胞、Surveyor assay等实验验证sgRNA的活性。其次,选取活性较高的sgRNA重组包装AAV-Cre病毒,应用立体定位将AAV病毒定点注射于小鼠纹状体。体外实验结果表明设计的3条sgRNA均能够有效地介导Cas9切割靶DNA。细胞免疫荧光实验结果证实AAV-Cre病毒具有Cre重组酶活性。最后,通过小鼠脑部组织免疫组化、TA-克隆、高通量测序及Western blot方法检测Slc20a2基因敲除效率,发现实验组小鼠纹状体组织Slc20a2表达明显降低。本研究成功设计了3条能够敲除Slc20a2的功能sgRNA,并应用CRISPR/Cas9技术成功构建了纹状体Slc20a2基因条件性敲除小鼠,为研究PFBC的发病机制提供了有效的动物模型。

Identification of Prophages within the Mycobacterium avium 104 Genome and the Link of Their Function Regarding to Environment Survival

Mycobacterium avium is an opportunistic bacterium associated with pathogenic behavior in both humans and animals. M. avium has evolved as a pathogen by having an environmental component in its life style. Prophages are the integrated viral forms in bacterium genome. They constitute about 10% - 20% of genome of many bacteria and they contribute to pathogenicity of microbes. We investigated whether the M. avium 104 genome contained prophages and evaluated the genes/proteins for putative functions. Three prophage genes were identified in the M. avium 104 database, and sequences were analyzed for specific motifs. The prophage sequences were then cloned in Mycobacterium smegmatis and the bacterial phenotype was evaluated in gain of function assays for environmental stresses, such as tolerance to extreme temperatures, UV light, biofilm formation and resistance to acid as well as macrophage survival. The results indicate that two of the prophage genes, MAV_0696 and MAV_2265, confer M. smegmatis with enhanced ability to produce biofilm. Using a Real-Time PCR, it was determined that MAV_0696 and MAV_2265 transcripts were upregulated upon biofilm formation by M. avium. The expression of MAV_2265 gene was significantly higher at all selected time points. In addition, the expression of MAV_2265 in M. smegmatis also led to significantly greater survival rate at pH 5.0 compared to the wild-type control. None of the other physical abilities were altered by overexpressing the prophage genes in M. smegmatis. In summary, we identified three prophage sequences in M. avium 104, from which two of them were found to be associated with biofilm formation and one with resistance to the acidic environment. Future studies will identify the mechanisms involved in the prophages function.

Parkin基因甲基化对鼻咽癌早期诊断及预后判断的价值评价

目的分析Parkin基因甲基化对鼻咽癌早期诊断及预后判断的价值。方法选择2010年1月-2014年12月在我院及合作医院接受治疗的鼻咽癌患者52例、鼻咽良性病变组65例,选择同期在我院接受健康体检的正常人志愿者60例,对比三组病理结果;鼻咽癌组跟踪随访36个月,观察并分析复发及转移情况。结果鼻咽癌组52例表达Parkin基因甲基化者40例(76.92%);鼻咽良性病变组及健康对照组均未发现Parkin基因甲基化表达;检出Parkin基因甲基化者3年生存率47.50%(19/40),未检出Parkin基因甲基化者3年生存率66.67%(8/12),但二者间差异无统计学意义(P>0.05)。结论 Parkin基因甲基化对鼻咽癌早期诊断及预后判断价值均良好。

Comparison of intravitreal injection of conbercept and triamcinolone acetonide for macular edema secondary to branch retinal vein occlusion

AIM:To compare the safety and efficacy of the intravitreal injection of conbercept(IVC)and triamcinolone acetonide(IVTA)for macular edema(ME)secondary to branch retinal vein occlusion(BRVO).METHODS:A prospective,randomized clinical study.Patients with ME secondary to BRVO were randomly assigned to either IVC group or IVTA group at a ratio of 2:1 and a 12-month follow-up was performed.The efficacy outcome measures included the mean changes and differences in best corrected visual acuity(BCVA)and the central retinal thickness(CRT).The safety profiles and the mean retreatment intervals were also compared.RESULTS:There was no statistically significant difference of baseline between the two groups(IVC group,n=36;IVTA group,n=17).At 12mof the BCVA letters improved by 27.31±18.36 in the IVC group,and 13.53±11.37 in the IVTA group(P=0.0004).CRT reduction was 253.33±163.69 and 150.24±134.32 pm,respectively(P=0.0034).The mean BCVA in the IVC group was superior to that of the IVTA group for months 6-12(P<0.01).The mean CRT at 9 and 12mo were thinner in the IVC group compared to the IVTA group(P<0.01).The mean retreatment interval in the IVC group was longer than that in the IVTA group(97.40±36.27d vs 68.71±36.38d,P=0.0030).One eye in the IVC group and seven eyes in the IVTA group developed elevated intraocular pressure(IOP;P=0.0012).The proportion of eyes with cataract new-onset or progression were 19.44%in the IVC group and 64.71%in the IVTA group(P=0.0012).CONCLUSION:IVC could maintain or improve BCVA and reduce CRT for a longer time and have longer retreatment interval than IVTA.In addition,patients treated with IVTA are more susceptible to IOP elevation and cataract progression.

Microbial community composition and environmental response characteristics of typical brackish groundwater in the North China Plain

To reveal the microbial community composition of regional shallow porous brackish groundwater and its response characteristics to groundwater environment,the first and second aquifers in Taocheng District,Hengshui City were selected,and 10 groundwater source samples were collected for hydrochemical analysis and microbial 16S RNA gene V4-V5 regional sequencing.The results showed that the shallow brackish groundwater in the study area is weakly alkaline and has high ion content.The hydrochemical types are SO_(4)·Cl-Na·Mg type and HCO3·Cl-Na·Mg type as a whole.The spatial zonation of the abundance and diversity of groundwater microorganisms is obvious.The number of endemic bacteria in groundwater from upstream,midstream to downstream is 11,135 and 22 respectively,with a total of 22 bacteria.Proteobacteria is the most dominant in groundwater level(38.82%-86.88%),and there are obvious differences in different sections.At the genus level,the main dominant species in each group and sample are Pseudomonas and Hydrogenophaga.In terms of composition difference,Pseudohongiella,Pseudorhodobacter and Limnohabitans are the representatives of UR,MR and LR.On the whole,the composition of flora in groundwater in the study area is sensitive and closely related to hydrochemical processes.Species abundance is affected by alkaline and high salinity environmental indicators,while species diversity is related to depth and dissolved oxygen in weak reduction environment.

Enhanced energy-absorbing and sound-absorbing capability of functionally graded and helicoidal lattice structures with triply periodic minimal surfaces

Lattice structures have drawn much attention in engineering applications due to their lightweight and multi-functional properties.In this work,a mathematical design approach for functionally graded(FG)and helicoidal lattice structures with triply periodic minimal surfaces is proposed.Four types of lattice structures including uniform,helicoidal,FG,and combined FG and helicoidal are fabricated by the additive manufacturing technology.The deformation behaviors,mechanical properties,energy absorption,and acoustic properties of lattice samples are thoroughly investigated.The load-bearing capability of helicoidal lattice samples is gradually improved in the plateau stage,leading to the plateau stress and total energy absorption improved by over 26.9%and 21.2%compared to the uniform sample,respectively.This phenomenon was attributed to the helicoidal design reduces the gap in unit cells and enhances fracture resistance.For acoustic properties,the design of helicoidal reduces the resonance frequency and improves the peak of absorption coefficient,while the FG design mainly influences the peak of absorption coefficient.Across broad range of frequency from 1000 to 6300 Hz,the maximum value of absorption coefficient is improved by18.6%-30%,and the number of points higher than 0.6 increased by 55.2%-61.7%by combining the FG and helicoidal designs.This study provides a novel strategy to simultaneously improve energy absorption and sound absorption properties by controlling the internal architecture of lattice structures.

Heavy metals in sediments of Yellow Sea and East China Sea: Chemical speciation,distribution,influence factor,and contamination

Metal species and the degree of environmental pollution are related to the hydrogen sulfide(H_(2)S),an important product of early diagenesis that can react with metals to form stable compounds.To investigate the eff ects of H_(2)S to metals and evaluate metal environment eff ect in the sediments of the East China Sea(ECS)and Yellow Sea(YS),geochemical characteristic and spatial distribution of nine heavy metals and H_(2)S profile were studied.Higher H_(2)S content and lower metal content was observed in the sediments 10 cm in depth in the North Yellow Sea and the west coast of South Korea.The pollution load index(I_(pl))indicates that the southern coast of Shandong Peninsula underwent moderate pollution(I_(pl)=1)of heavy metals and no heavy metal pollution appeared in other areas(I_(pl)<1).To some extents,the ecological risk of Cd and As enrichment was moderately severe in all stations.The chance of heavy metal combination to be toxic in ECS and YS during summer was 21%.In addition,correlation between H_(2)S content and metals in both solid and porewater phases was obvious,corroborating important eff ect of H_(2)S on metal distribution.Moreover,H_(2)S could aff ect the spatial distributions of heavy metals in porewater directly and be indicative of potential biological eff ects of combined toxicant groups in the study region.

A study on carbon emission calculation in operation stage of residential buildings based on micro electricity usage behavior:Three case studies in China

Along with the improvement of social productivity and living standard,residential buildings generate a growing portion of carbon emissions,especially during the operation stage.However,energy use behaviors are usually ignored in carbon emission calculation.This study focuses on calculating carbon emissions during the operation stage for residential buildings based on the characteristics of energy use behaviors in different regions.Firstly,we investigated energy use behaviors in dwellings across three cities in China:Xi'an,Shanghai and Fuzhou.Then,we established calibrated carbon emission models and optimization models with different green building measures for residential buildings.The results of this research reveal a significant disparity between the energy usage habits of residents in different climate regions.The carbon emissions of residential electricity bills in Xi'an,Shanghai and Fuzhou are 13.6 kgCO_(2)/(m^(2)·a)(excluding central heating),29.3 kgCO_(2)/(m^(2)·a)and 17.2 kgCO_(2)/(m^(2)·a),respectively.Equipment carbon emissions account for 32.2%-64.1% of the total.In comparison to the model based on internal standard setting,the accuracy of the models using actual internal has improved by 25.9%-37.4%.The three-star green building methods have the highest carbon reduction rate among different star buildings,the emission reduction rates are around 30%.This study's findings are useful for carbon emission calculation and green building design of residential buildings in the future.

Gd_(3)Al_(3)Ga_(2)O_(12):Ce^(3+), Yb^(3+) fluorescent ceramic with highly increased trap density for optical information storage

Electron-trapping materials,due to their exceptional ability of energy storage and controllable photon release under external stimulation,have attracted considerable attention in the field of optical information storage(OIS).In this work,Gd_(3)Al_(3)Ga_(2)O_(12):Ce^(3+), Yb^(3+)fluorescent ceramics,were developed using air and vacuum sintering technology.By co-doping Ce^(3+)and Yb^(3+),the trap density was significantly increased by 7.5 times compared to samples containing only Ce^(3+).Vacuum annealing further enhanced trap density by 1.6 times compared to samples sintered solely in air,while generating deep traps(1.44 eV),making Gd_(3)Al_(3)Ga_(2)O_(12):Ce^(3+), Yb^(3+) an excellent OIS medium.This work is expected to facilitate the development of OIS materials.

Brainstem opioid peptidergic neurons regulate cough reflexes in mice

Cough is a vital defensive reflex for expelling harmful substances from the airway.The sensory afferents for the cough reflex have been intensively studied.However,the brain mechanisms underlying the cough reflex remain poorly understood.Here,we developed a paradigm to quantitatively measure cough-like reflexes in mice.Using this paradigm,we found that prodynorphin-expressing(Pdyn+)neurons in the nucleus of the solitary tract(NTS)are critical for capsaicin-induced cough-like reflexes.These neurons receive cough-related neural signals from Trpv1+vagal sensory neurons.The activation of Pdyn+NTS neurons triggered respiratory responses resembling cough-like reflexes.Among the divergent projections of Pdyn+NTS neurons,a glutamatergic pathway projecting to the caudal ventral respiratory group(cVRG),the canonical cough center,was necessary and sufficient for capsaicin-induced cough-like reflexes.These results reveal that Pdyn+NTS neurons,as a key neuronal population at the entry point of the vagus nerve to the brainstem,initiate cough-like reflexes in mice.

Dynamic temperature prediction of electronic equipment under high altitude long endurance conditions

Unmanned Aerial Vehicle（UAV） is developing towards the direction of High Altitude Long Endurance（HALE）. This will have an important influence on the stability of its airborne electronic equipment using passive thermal management. In this paper, a multi-node transient thermal model for airborne electronic equipment is set up based on the thermal network method to predict their dynamic temperature responses under high altitude and long flight time conditions. Some relevant factors are considered into this temperature prediction model including flight environment,radiation, convection, heat conduction, etc. An experimental chamber simulating a high altitude flight environment was set up to survey the dynamic thermal responses of airborne electronic equipment in a UAV. According to the experimental measurement results, the multi-node transient thermal model is verified without consideration of the effects of flight speed. Then, a modified way about outside flight speed is added into the model to improve the temperature prediction performance. Finally, the corresponding simulation code is developed based on the proposed model. It can realize the dynamic temperature prediction of airborne electronic equipment under HALE conditions.

Anti-Hypertensive Action of Fenofibrate via UCP2 Upregulation Mediated by PPAR Activation in Baroreflex Afferent Pathway

Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha(PPAR-a), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the distribution of PPAR-a and PPAR-c was assessed in the nodose ganglion(NG) and the nucleus of the solitary tract(NTS). Hypertension induced by drinking high fructose(HFD) was reduced, along with complete restoration of impaired baroreceptor sensitivity, by chronic treatment with fenofibrate. The molecular data also showed that both PPAR-a and PPAR-c were dramatically up-regulated in the NG and NTS of the HFD group. Expression of the downstream signaling molecule of PPAR-a, the mitochondrial uncoupling protein 2(UCP2), was up-regulated in the baroreflex afferent pathway under similar experimental conditions, along with amelioration of reduced superoxide dismutase activity and increased superoxide in HFD rats.These results suggest that chronic treatment with fenofibrate plays a crucial role in the neural control of blood pressure by improving baroreflex afferent function due at least partially to PPAR-mediated up-regulation of UCP2 expression and reduction of oxidative stress.

Neural circuit control of innate behaviors

All animals possess a plethora of innate behaviors that do not require extensive learning and are fundamental for their survival and propagation.With the advent of newly-developed techniques such as viral tracing and optogenetic and chemogenetic tools,recent studies are gradually unraveling neural circuits underlying different innate behaviors.Here,we summarize current development in our understanding of the neural circuits controlling predation,feeding,male-typical mating,and urination,highlighting the role of genetically defined neurons and their connections in sensory triggering,sensory to motor/motivation transformation,motor/motivation encoding during these different behaviors.Along the way,we discuss possible mechanisms underlying binge-eating disorder and the pro-social effects of the neuropeptide oxytocin,elucidating the clinical relevance of studying neural circuits underlying essential innate functions.Finally,we discuss some exciting brain structures recurrently appearing in the regulation of different behaviors,which suggests both divergence and convergence in the neural encoding of specific innate behaviors.Going forward,we emphasize the importance of multi-angle and cross-species dissections in delineating neural circuits that control innate behaviors.

Fluorescein-derived fluorescent probe for cellular hydrogen sulfide imaging

In this work, a fluorescein-derived fluorescent probe for H2S based on the thiolysis of dinitrophenyl ether is reported. This probe exhibits turn-on fluorescence imaging of H2S in living cells and bulk solutions with excellent selectivity. The reaction mechanism was explained by means of absorption, fluorescence and HPLC-MS.