Application of aspirin and low molecular weight heparin in major orthopedic surgery:Meta analysis of a randomized controlled trial

Objective:The perioperative period of major orthopedic surgery is associated with a high risk of thrombosis,but the best chemopreventive agent for thrombosis prophylaxis is still inconclusive.For this reason,this paper evaluated the efficacy and safety of aspirin versus low-molecular heparin using a Meta-analysis.Methods:Ten randomized controlled studies on the application of aspirin and low-molecular heparin for the prevention of deep vein thrombosis in orthopedic major surgery were retrieved by computer searches of PubMed,CochraneLibrary,WebofScience,China Knowledge Network,Wanfang,and Vipul databases according to inclusion and exclusion criteria,and the literature was managed using Endnote software,and the data were analyzed using Revman 5.3 software was used to perform Meta-analysis of the extracted data,focusing on the effects of these two drugs on pulmonary embolism,deep vein thrombosis,major bleeding events,minor bleeding events,wound complications,mortality and blood loss within 90 days after major orthopedic surgery.Results:(1)Ten randomized controlled trials of high quality were included,with a total of 12,974 patients,7,026 in the aspirin group and 5,948 in the low-molecular heparin group;(2)Meta-analysis showed that aspirin had a higher incidence of pulmonary embolism(OR=1.59,95%CI:1.02 to 2.49,P=0.04)and deep vein thrombosis(OR=1.60,95%CI:1.26 to 2.02,P=0.0001)than low molecular heparin;(3)The incidence of major bleeding events(OR=0.85,95%CI:0.47 to 1.55,P=0.60),minor bleeding events(OR=0.79,95%CI:0.55 to 1.12,P=0.18),adverse wound reactions(OR=0.79,95%CI:0.48 to 1.31,P=0.36),mortality within 90 days(OR=0.69,95%CI:0.20 to 2.31,P=0.55)and perioperative blood loss(MD=0.69,95%CI:0.20 to 2.31,P=0.55)in both drug groups,mortality within 90 days(OR=0.69,95%CI:0.20 to 2.31,P=0.55)and perioperative blood loss(MD=0.69,95%CI:0.20 to 2.31,P=0.55)were not statistically significant.Conclusion:Low-molecular heparin was superior to aspirin in the prevention of pulmonary embolism and lower extremity deep vein thrombosis after major orthopedic surgery,but the safety and adverse drug reactions of both groups were basically similar.Based on this,the authors recommend that low-molecular heparin should be preferred for the prevention of deep vein thrombosis in major orthopaedic surgery;however,the inclusion of randomized controlled trials remains limited,necessitating high-quality,large-sample,long-term follow-up clinical studies.

柴金解郁安神片调控CaMKII和Cofilin双信号通路改善抑郁症海马谷氨酸能神经元突触重塑

目的探讨柴金解郁安神片调控钙/钙调蛋白依赖性蛋白激酶Ⅱ(CaMKII)和Cofilin双信号通路,改善抑郁症海马谷氨酸能神经元突触重塑的分子机制。方法皮质酮联合脂多糖建立抑郁症体外细胞模型,实验设正常组、模型组、GR阻断剂组、GR激动剂组、CX3CR1阻断剂组、CX3CR1激动剂组、柴金解郁安神片组、柴金解郁安神片联合GR激动剂组、柴金解郁安神片联合CX3CR1激动剂组,观察星形胶质细胞、小胶质细胞、前扣带皮层(anterior cingulate cortex,ACC)和海马神经元形态结构变化;检测ACC和海马谷氨酸能神经元激活及突触重塑情况;免疫荧光、Western blot分别检测海马谷氨酸能神经元内突触重塑相关谷氨酸受体2A(GRIN2A)、GRIN2B、CaMKII、MK2、Cofilin蛋白表达水平。结果柴金解郁安神片能明显改善胶质细胞、ACC和海马神经元损伤,并抑制ACC和海马谷氨酸能神经元异常激活,同时下调GRIN2A、GRIN2B、MK2蛋白,上调CaMKII、Cofilin蛋白,继而改善海马谷氨酸能神经元突触可塑性损伤和突触重塑。结论柴金解郁安神片能有效改善抑郁症海马谷氨酸能神经元突触重塑,其分子机制与调节突触重塑相关NR/CaMKII、MK2/Cofilin信号通路有关。

可降解Zn-Li合金吻合钉的自然时效与降解机制研究

作为力学性能良好,降解速率适中的可降解金属,Zn基合金的应用前景十分广阔。研究了自然时效对Zn-Li合金性能的影响以及Zn-Li合金吻合钉的体外降解机制。通过拉伸试验和电化学试验分析时效时间对Zn-Li合金丝力学性能和耐蚀性的影响。采用浸泡实验,根据吻合钉质量变化分析不同模拟液对Zn-Li吻合钉降解速率的影响,采用扫描电子显微镜分析Zn-Li吻合钉不同部位的降解模式。结果表明,时效2.0 a的Zn-Li合金丝比时效1.0 a的拉伸强度低43.86 MPa,伸长率下降24.17%,腐蚀电势由-1.07 V下降至-1.12 V,腐蚀电流密度增加13%。Zn-Li吻合钉在模拟体液中降解速率最大,钉脚的微电偶腐蚀为最严重的腐蚀形式。

靛玉红通过下调Cyclin A2阻滞细胞周期抑制小鼠Lewis肺癌的体内外及网络药理学研究

目的研究中药成分靛玉红在体内外对小鼠Lewis肺癌(LLC)的抑制效果及对细胞周期的调节作用。方法通过细胞毒性实验探究靛玉红在体外对小鼠LLC细胞的抑制作用。构建肺癌原位小鼠模型,随机分为模型组(磷酸盐缓冲液灌胃,每天1次)和靛玉红低、中、高剂量组(25 mg/kg、50 mg/kg、100 mg/kg灌胃,每天1次)、顺铂组(2 mg/kg腹腔注射,每3天1次),连续3周,记录生存期和体质量。通过活体成像法记录小鼠肺癌进展,取肺肿瘤组织,称重并计算抑瘤率。通过网络药理学预测靛玉红治疗肺癌的核心靶点和通路。Western blot法分别验证靛玉红在体外对LLC细胞及在体内对小鼠肺癌组织中细胞周期蛋白A2(Cyclin A2)表达的影响;免疫组织化学染色(IHC)法和实时荧光定量逆转录聚合酶链式反应(RT-qPCR)法分别检测靛玉红对小鼠肺癌组织中Cyclin A2蛋白及其编码基因CCNA2表达的影响。流式细胞术和IHC法分别检测靛玉红对小鼠肺癌肿瘤细胞的细胞周期和肺癌肿瘤增殖抗原Ki-67表达的影响。结果靛玉红在体外对小鼠LLC细胞的抑制作用呈剂量和时间依赖性,24 h、48 h、72 h的半抑制浓度(IC_(50))分别为188.7μmol/L、109.0μmol/L、58.3μmol/L。与模型组比较,靛玉红中剂量组小鼠肺部荧光表达降低(P<0.05),生存率提高(中位生存期延长7 d),肿瘤抑制率较高(37.76%),且对小鼠体质量没有明显影响(P>0.05)。网络药理学分析表明,靛玉红抑制肺癌可能通过调控细胞周期及Cyclin A2实现。进一步研究证明,靛玉红通过抑制Cyclin A2,导致细胞周期S期阻滞,抑制肿瘤细胞增殖。结论靛玉红体外抑制小鼠LLC细胞,体内通过下调肺癌肿瘤细胞Cyclin A2导致细胞周期阻滞,抑制肿瘤进展,延长肺癌小鼠生存期。

基于机载LiDAR点云的电力线提取和三维重建方法

从LiDAR点云数据中提取电力线进行三维重建已经成为安全巡检的重要技术手段。本文提出一种电力线提取与重建方法,对获取的LiDAR点云数据,通过高程阈值分割法和直线检测得到直线方程提取电力线,并通过电塔定位实现电力线分档;然后,通过直线模型和悬链线模型结合的方法对提取的分档电力线进行三维建模。实验结果表明,该算法能实现电力线的提取和分档,且重建模型能实现电力线的三维重建,对电力巡线具有实际的应用意义。

Robust Timing Constraints for Granitic Magmatism and Hydrothermal Mineralization in the Tieshanlong W-Sn Ore Field,Eastern Nanling Range,South China

The Tieshanlong ore field is an important part of the Nanling Range,which is famous worldwide for its W-Sn mineralization.Notably,the mineralization age of the Tieshanlong ore field is not well constrained,and our field investigation reveals that granitic emplacement occurred at different stages.However,previous studies have not distinguished these multiple stages of magmatism.The Tieshanlong granite complex is closely related to the Huangsha quartz vein-type W-Sn deposit and Tongling skarn-type Cu-W-Sn deposit in this field.Through field investigations and isotopic age analyses,this work studies the relationship between multistage magmatic activity and mineralization in the Tieshanlong ore field.LA-ICP-MS zircon U-Pb isotope analyses revealed that the first-and second-staged granites formed at 154.2±0.6 Ma(MSDW=1.4)and 151.2±0.4 Ma(MSDW=1.5),with zirconε_(Hf)(t)values ranging from-13.1 to-10.5 and from-14.7 to-11.1,respectively.These data suggest that the Tieshanlong granite complex was derived from the partial melting of ancient crustal material.LA-ICP-MS U-Pb dating of wolframite and cassiterite reveals that W-Sn mineralization occurred at 160-150 Ma,which agrees well with the U-Pb dating results of the second-staged granite within analytical errors.The magmatic activity in this ore field can be divided into three stages:175-154 Ma,154-150 Ma and 150-145 Ma.The quartz vein-and skarn-type W-Sn mineralization is closely related to second-staged fine-grained twomica granite,and formed earlier than skarn-type Cu-mineralization.This study establishes a metallogenic model for the Tieshanlong ore field,and this model has important practical significance for identifying concealed W-Sn(-Cu)deposits around other granitic complexes in the Nanling Range.

Nitrogen application regulates antioxidant capacity and flavonoid metabolism,especially quercetin,in grape seedlings under salt stress

Salt stress is a typical abiotic stress in plants that causes slow growth,stunting,and reduced yield and fruit quality.Fertilization is necessary to ensure proper crop growth.However,the effect of fertilization on salt tolerance in grapevine is unclear.In this study,we investigated the effect of nitrogen fertilizer(0.01 and 0.1 mol L^(-1)NH_(4)NO_(3))application on the salt(200 mmol L^(-1)NaCl)tolerance of grapevine based on physiological indices,and transcriptomic and metabolomic analyses.The results revealed that 0.01 mol L^(-1)NH_(4)NO_(3) supplementation significantly reduced the accumulation of superoxide anion(O_(2)^(-)·),enhanced the activities of superoxide dismutase(SOD)and peroxidase(POD),and improved the levels of ascorbic acid(AsA)and glutathione(GSH)in grape leaves compared to salt treatment alone.Specifically,joint transcriptome and metabolome analyses showed that the differentially expressed genes(DEGs)and differentially accumulated metabolites(DAMs)were significantly enriched in the flavonoid biosynthesis pathway(ko00941)and the flavone and flavonol biosynthesis pathway(ko00944).In particular,the relative content of quercetin(C00389)was markedly regulated by salt and nitrogen.Further analysis revealed that exogenous foliar application of quercetin improved the SOD and POD activities,increased the AsA and GSH contents,and reduced the H_(2)O_(2) and O_(2)^(-)·contents.Meanwhile,10 hub DEGs,which had high Pearson correlations(R^(2)>0.9)with quercetin,were repressed by nitrogen.In conclusion,all the results indicated that moderate nitrogen and quercetin application under salt stress enhanced the antioxidant system defense response,thus providing a new perspective for improving salt tolerance in grapes.

Battlefield target intelligence system architecture modeling and system optimization

To address the current problems of poor generality,low real-time,and imperfect information transmission of the battlefield target intelligence system,this paper studies the battlefield target intelligence system from the top-level perspective of multi-service joint warfare.First,an overall planning and analysis method of architecture modeling is proposed with the idea of a bionic analogy for battlefield target intelligence system architecture modeling,which reduces the difficulty of the planning and design process.The method introduces the Department of Defense architecture framework(DoDAF)modeling method,the multi-living agent(MLA)theory modeling method,and other combinations for planning and modeling.A set of rapid planning methods that can be applied to model the architecture of various types of complex systems is formed.Further,the liveness analysis of the battlefield target intelligence system is carried out,and the problems of the existing system are presented from several aspects.And the technical prediction of the development and construction is given,which provides directional ideas for the subsequent research and development of the battlefield target intelligence system.In the end,the proposed architecture model of the battlefield target intelligence system is simulated and verified by applying the colored Petri nets(CPN)simulation software.The analysis demonstrates the reasonable integrity of its logic.

Effect of the extrahepatic bile duct anatomy on choledocholithiasis and its clinical significance

BACKGROUND A comprehensive understanding of the extrahepatic bile duct anatomy is vital to guide surgical procedures and perform endoscopic retrograde cholangiography.Anatomical irregularities within the extrahepatic bile duct may increase susceptibility to bile duct stones.AIM To investigate the anatomical risk factors associated with extrahepatic bile ducts in patients diagnosed with choledocholithiasis,with a specific focus on preventing stone recurrence after surgical intervention and endoscopic lithotomy.METHODS We retrospectively analyzed the medical records of 124 patients without choledocholithiasis and 108 with confirmed choledocholithiasis who underwent magnetic resonance cholangiopancreatography examinations at our center between January 2022 and October 2022.Logistic regression analyses were conducted to identify the anatomical risk factors influencing the incidence of common bile duct stones.RESULTS Multivariate logistic regression analysis revealed that several factors independently contributed to choledocholithiasis risk.Significant independent risk factors for choledocholithiasis were diameter of the common hepatic[adjusted odds ratio(aOR)=1.43,95%confidence interval(CI):1.07-1.92,adjusted P value=0.016]and common bile(aOR=1.68,95%CI:1.27-2.23,adjusted P value<0.001)ducts,length of the common hepatic duct(aOR=0.92,95%CI:0.84-0.99,adjusted P value=0.034),and angle of the common bile duct(aOR=0.92,95%CI:0.89–0.95,adjusted P value<0.001).The anatomical features of the extrahepatic bile duct were directly associated with choledocholithiasis risk.Key risk factors include an enlarged diameter of the common hepatic and bile ducts,a shorter length of the common hepatic duct,and a reduced angle of the common bile duct.

基于DALI调光系统的某指挥调度大厅照明设计

指挥调度大厅作为重要的决策和控制中心,其照明设计对于保障工作效率、人员舒适度和信息准确传递至关重要。以某指挥调度大厅照明系统设计为例,重点围绕大厅软膜天花照明整体设计方案、照度计算、DALI调光系统等方面,对相关特点、要点、难点进行了论述和分析,旨在为类似指挥调度大厅等大面积场所的照明设计提供参考和借鉴。

GCNT3通过PI3K/Akt/mTOR和RhoA/ROCK/Cofilin途径促进肝癌细胞增殖、迁移和侵袭(英文)

β-1,3-半乳糖-O-糖基-糖蛋白β-1,6-N-乙酰氨基葡萄糖转移酶(β-1,3-galactosyl-O-glycosyl-glycoproteinβ-1,6-N-acetylglucosaminyltransferase,GCNT3)是黏液蛋白质生物合成中不可缺少的一类N-乙酰葡萄糖转移酶。越来越多的证据表明,GCNT3的异常表达与肿瘤的侵袭以及病人的生存率有关,然而相关的研究仍较少报道。本研究旨在揭示GCNT3在调控肝细胞癌进程中的潜在机制。本研究首先利用高通量基因表达数据库(Gene Expression Omnibus,GEO)和癌症基因组图谱(Cancer Genome Atlas databases,TCGA)数据库分析肝癌和正常组织中GCNT3的mRNA表达水平,结果表明,肝癌组织中GCNT3的mRNA表达水平高于正常组织(P≤0.001)。同时利用免疫组化、Western印迹进一步分析了肝癌组织、癌旁组织、正常组织中GCNT3蛋白的表达,发现有30%肝癌组织GCNT3表达水平高于癌旁组织和正常组织。随后,在肝癌细胞系HCCLM3和Huh7细胞中,采用CCK-8、平板克隆、划痕实验、Transwell实验分析GCNT3对肝癌细胞增殖、迁移和侵袭能力的影响,结果显示,敲低GCNT3可抑制肝癌细胞的增殖、迁移和侵袭,而过表达GCNT3发挥相反作用。细胞周期和Western印迹结果显示,GCNT3调控G_(0/)G_1期关键蛋白质的表达来促进肝癌细胞周期G_1/S的转换。进一步探究发现,GCNT3可能通过激活PI3K/AKT/mTOR信号通路促进细胞增殖;以及GCNT3上调RhoA/ROCK/Cofilin通路关键蛋白质的表达来促进F-肌动蛋白(F-actin)的形成,从而参与细胞的迁移和侵袭。总之,本研究通过对GCNT3在肝癌细胞中的功能分析,初步证明,GCNT3与肝癌细胞增殖、迁移和侵袭中的功能有关,证实了GCNT3在肝癌临床治疗中的潜在价值,为肝癌治疗和诊断提供了新思路。

Sentinel-2 MSI和Landsat 8 OLI数据在玉米秸秆覆盖度遥感估算应用中的比较研究

秸秆覆盖度(Crop residue cover, CRC)的遥感估算可以在短时间内获取大范围耕地秸秆覆盖度数据,对于政府部门监测保护性耕作的实施情况有重要的现实意义。本研究基于Sentinel-2 MSI和Landsat 8 OLI数据,分别计算了多种光谱指数,并与野外实测的秸秆覆盖度数据进行相关性分析,挑选出极显著性相关的光谱指数。在此基础上,构建其与秸秆覆盖度之间的相关模型,并通过决定系数(R2)和均方根误差(RMSE)所表征模型的精度比较Sentinel-2 MSI和Landsat 8OLI数据由于光谱和空间尺度的差异对秸秆覆盖度反演模型的影响。结果表明:6种光谱指数与CRC的相关性系数均大于0.4,相关性较高的是Sentinel-2 MSI 20 m分辨率数据获取的NDTI和STI,相关系数分别为0.878、0.894,相关性最低的为Sentinel-2 MSI 10 m分辨率数据获取的NDSVI,相关系数为0.476;利用一元线性回归法构建模型时,Sentinel-2 MSI 20 m分辨率数据构建的光谱指数STI和NDTI,模型精度最高,R^(2)分别为0.810和0.800,RMSE分别为6.84%和7.01%,而30 m重采样数据的R^(2)分别为0.770和0.771,RMSE分别为7.52%和7.50%,随着空间分辨率的降低呈现出下降趋势;Sentinel-2MSI 30 m重采样数据获取的光谱指数构建的所有模型精度均略大于Landsat 8 OLI数据构建的模型。因此,Sentinel-2 MSI数据获取NDTI和STI这两个光谱指数更加适合本研究区域秸秆覆盖度的估算。

全球心血管疾病学术影响力评价(CAPE)体系的方法探索

目的:构建全球心血管疾病学术影响力评价(Cardiovascular Academic Performance Evaluation,CAPE)体系,并对全球医疗机构心血管疾病学术影响力进行排名。方法:由心血管疾病领域人员和图书情报人员提取医学主题词表(MeSH)、Embase同义词表、国际疾病分类(ICD)中心血管疾病相关术语,建立心血管术语词表(即阜外词表),设定缺血性心脏病、高血压、血管疾病、心律失常、肺血管疾病、心力衰竭、先天性心脏病、心肌病和瓣膜性心脏病等9个亚学科,实现亚学科分类、心血管术语词、入口词的映射。检索Web of Science、PubMed、Scopus数据库2016年1月1日至2022年12月31日的心血管领域论文,并对元数据进行去重融合;应用阜外词表对论文中主题词、题目、关键词、摘要等4个位置的内容进行检索匹配,生成论文“位置-心血管术语词-频次”的信息表,计算每一篇论文心血管学科相关度积分及亚学科积分。对论文的机构名、学者名进行规范化清洗,基于心血管强相关(相关度积分≥4分)原创性论文开展全球心血管疾病领域学术影响力的评价。针对全国医疗机构(心血管)的科技评价,还采集了国家自然科学基金项目、授权发明专利、获奖成果、科研平台、注册试验[国家药品监督管理局药品审评中心(CDE)药物临床试验登记数据]等数据。结果:检索到全球2016~2022年心血管领域论文1545103篇,剔除摘要、书籍、传记、新闻、视频、音频、撤稿、更正声明后为1178019篇,使用阜外词表标引“心血管强相关”论文518058篇。还采集到11143项心血管相关国家自然科学基金项目、19382项心血管相关有效授权发明专利、103项心血管相关国家级获奖成果、24个心血管相关国家科研平台、2084项CDE心血管相关药物临床试验登记等数据。经组织心血管疾病及其亚学科专家团队针对各自亚学科论文进行核对和验证,改进学科分类规则,最终锁定11项指标构建了心血管疾病和9个亚学科领域的综合评价指标体系。2016~2022年,中国发表心血管疾病研究论文数量增幅为123.5%,共发表约7.68万篇,平均每天约30篇,仅次于美国(约11.41万篇),居世界第二位。但中国期刊引证报告(JCR)分区和中国科学院分区论文占比仅居世界第八位。在2020~2022年全球医疗机构心血管原创研究论文影响力综合评估中,仅2家中国医疗机构进入前20名。结论:CAPE项目基于2016~2022年多源数据基础,首次探索建立了心血管领域机构学术影响力综合评价指标体系。

拉萨河下游湿地土壤养分特征与肥力评价

[目的]为探索拉萨河下游湿地土壤的养分特征和肥力状况。[方法]选取甘曲湿地、巴嘎雪湿地、拉鲁湿地和茶巴朗湿地4个代表性区域的土壤为研究对象,共采集69份土壤样本,测定样品的pH、总氮(TN)、总磷(TP)、总钾(TK)、全盐、电导率、氧化还原电位(redox potential)、阳离子交换量(CEC)和有机质(OM)值,并利用改进内梅罗综合指数法对湿地土壤肥力进行全面的评价。[结果](1)研究区土壤的pH范围为5.77~7.78,均值为6.62,呈中性;有机质和总氮的相关性强,分布特征相似,含量分别为61.82,3.13 g/kg,均为很丰富的状态,属于一级水平;总磷和总钾含量分别为0.75,18.05 g/kg,为适中的状态,属于三级水平;全盐含量为0.92 g/kg,电导率为2.97 mS/m,整体来看,研究区土壤具有较强的保肥能力。(2)湿地土壤综合肥力系数(P)顺序为茶巴朗湿地(2.01)>巴嘎雪湿地(1.95)>拉鲁湿地(1.93)>甘曲湿地(1.86),均属于肥沃等级,影响湿地土壤综合肥力的指标是总钾,因各自然湿地形成条件相似,土壤综合肥力系数无显著差异。[结论]研究结果明晰了拉萨河下游湿地土壤养分现状,为实现研究区湿地资源的可持续利用提供科学依据。

黄芩苷对干酵母致热大鼠的解热作用及血清TNF-α、IL-1β、IL-6、PGE_(2)、cAMP和脑组织NF-κB表达的影响

目的:观察黄芩苷对干酵母致热大鼠的解热作用并探讨其作用机制。方法:采用背部皮下注射干酵母构建大鼠发热模型,SD雄性大鼠随机分为正常对照,模型组,阳性组(阿司匹林,0.1 g/kg),黄芩苷高、中、低剂量组(160、80、40 mg/kg),连续给药3 d,测定各组大鼠肛温的变化;酶联免疫法(ELISA)检测血清肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、白细胞介素-6(IL-6)、前列腺素E_(2)(PGE_(2))与环磷酸腺苷(cAMP)水平;Western Blot检测各组大鼠脑组织NF-κB p65(核转录因子-κB p65)蛋白表达。结果:黄芩苷高剂量组有显著解热效果(P<0.01),黄芩苷各剂量组均可不同程度降低大鼠血清TNF-α、IL-1β、IL-6、PGE 2和cAMP含量;与正常组比较,模型组脑组织NF-κB p65蛋白表达增多,黄芩苷高剂量组可明显降低大鼠脑组织NF-κB p65表达(P<0.05)。结论:黄芩苷可显著性降低干酵母引起的体温升高,解热机制可能与抑制TNF-α、IL-1β、IL-6、PGE_(2)与cAMP的分泌和减少脑组织NF-κB p65蛋白表达有关。

脑梗死患者颈动脉斑块超声造影特征与梗死特征的相关性

目的探究脑梗死患者颈动脉超声造影的特征及与不同梗死部位、面积等梗死特征的相关性。方法回顾性分析郑州大学第二附属医院2018-02—2021-03诊治的135例脑梗死患者,所有患者均接受超声造影检查,另选取同期因颈动脉斑块行超声造影检查的无症状中老年人112例为对照组,比较2组患者超声造影参数,包括峰值强度比值(P)、曲线下面积(AUC)、达峰时间(Tp)。将脑梗死患者按梗死部位、梗死面积分成不同亚组,分析不同亚组颈动脉斑块超声造影相关参数。结果脑梗死患者P和AUC值均明显高于对照组,Tp值明显低于对照组(P<0.05)。随着颈动脉狭窄程度的加重,P和AUC值明显升高,Tp值明显降低(P<0.05)。Spearman相关性分析显示,P、AUC值与颈动脉狭窄程度呈正相关,Tp值与狭窄程度呈负相关(P<0.05)。不同梗死部位间颈动脉狭窄程度比较有统计学差异(P<0.05),其中皮质梗死组患者颈动脉完全闭塞发生率最高;不同梗死面积患者颈动脉狭窄程度比较差异有统计学意义(P<0.05),其中大面积梗死组完全闭塞发生率最高。结论脑梗死患者颈动脉斑块超声造影参数水平明显异于无症状有斑块者,且皮质部位脑梗死患者颈动脉完全闭塞发生率最高,大面积脑梗死患者更易发生颈动脉完全闭塞。

分簇式VLIW密码专用处理器的编译器后端优化研究

密码专用处理器常采用分簇式超长指令字(Very Long Instruction Word,VLIW)架构,其性能的发挥依赖于编译器的实现.当前对于通用VLIW架构的编译后端优化方案,在密码专用处理器上都有一定的不适应性.为此,本文提出了一种面向密码专用处理器的、同时进行簇指派、指令调度和寄存器分配的编译器后端优化方法.构造“定值-引用”链,求解变量的候选寄存器类型集合交集,确定其寄存器类型;实时评估可用资源,进行基于优先级的指令选择和基于平衡寄存器压力的簇指派;改进线性扫描算法,基于变量的“待引用次数”列表进行实时的寄存器分配.实验结果表明,本方法能够提升生成代码的性能,且算法是非启发式的,减小了编译所需的时间.

基于超音速膨胀凝结的油田伴生气脱二氧化碳研究

油田伴生气通常含有大量的二氧化碳等酸性气体,为了提升油田伴生气质量,必须对天然气进行脱二氧化碳处理;将超音速旋流分离技术用于伴生气脱除二氧化碳是一条全新路径,但二氧化碳在超音速流动条件下的冷凝特性有待进一步明晰。建立二氧化碳在喷管中的相变过程数学模型,讨论二氧化碳超音速凝结流动特性,分析入口温度和压力对二氧化碳超音速凝结特性的影响规律。结果表明:二氧化碳在喷管喉部之后的扩张段发生凝结,生成大量的二氧化碳液滴;随着喷管入口温度增加,尽管凝结的二氧化碳液滴数量增加,但喷管出口和中轴线上的液相质量分数减小,凝结位置越靠近喷管出口;随着喷管入口压力增加,混合气体在喷管出口的压力和温度升高、速度减小,二氧化碳在喷管内凝结产生的液滴数量减少,喷管出口和中心轴线上的液相质量分数越大。

找回传统与再塑组织:乡村治理中的“嵌入式协同”何以有效运转——基于国家与社会关系的分析视角

在乡村治理场域中,协同治理网络中的主体、组织和规则都存在着内生性与外生性、传统性与现代性的分殊。因此,乡村治理网络必然要在“嵌入”基础上实现协同。此文通过对华南地区B镇进行长期追踪,发现挖掘传统治理资源,并将现代化的组织形式与组织规则嵌入乡村内生治理系统,能够有效地为乡村治理共识凝聚、主体参与、资源动员提供组织化路径,构建极具韧性的制度化协同网络。基于此,乡村社会“嵌入式协同”的治理有效性逻辑在于,其能够使来自行政系统与社会系统中承担不同角色的治理主体在关系互嵌、组织互融、规则互补的基础上,建立起功能适配、运转和谐的协同网络。

燃用高碱煤锅炉受热面结焦及其防治研究概述

以准东煤为代表的高碱煤虽储量巨大,但火电机组掺烧高碱煤过程中造成锅炉受热面结焦问题突出,不仅降低锅炉热效率,而且严重威胁机组安全、稳定、经济运行。为解决结焦技术难题,促进高碱煤掺烧利用,对燃用高碱煤锅炉受热面结焦及其防治研究进行了综述。截至目前,国内外围绕燃煤锅炉受热面结焦特征、结焦机理、影响因素、防治措施等已经开展了广泛研究并取得了丰硕的研究成果。在控制燃煤质量、改善锅炉结构、优化锅炉运行等措施基础上,在锅炉受热面制备涂层成为防治结焦的重要技术途径。在未来研究过程中,涂层在具备突出抗结焦性能的同时,须兼具优良的耐高温、抗腐蚀、耐磨损、导热性、热疲劳等综合性能,且具有良好的制备经济性、制备效率,特别是现场适用性。