Analysis and discussion of different methods of artificial ice-high specimen preparation

Because ice-high foundation soil is widely distributed in permafrost regions,the correct preparation of ice-high specimens is of critical interest in engineering design for foundation stability.Past research has shown that the uniaxial compression strength of ice-high frozen soils changes as the ice or total water content increases; the differences of different methods of specimen preparation are analyzed here and the advantages and disadvantages of them are presented.It is confirmed that the role of crushed ice is significantly different from that of naturally frozen ice in frozen soils,and the size and amount of crushed ice will influence the strength and deformation mechanism of frozen soils.Therefore,it is strongly recommended that when a ice-high specimen is artificially prepared,the ice should be frozen through natural means and not be replaced with crushed ice.

Bird specimen number linked with species trait and climate niche breadth

Biological specimens are fundamental for taxonomy and flora/fauna research.More importantly,they also play crucial roles in recording environmental impacts on morphology and behavior,which is vital for biodiversity research and conservation.However,there are few systematic studies on the patterns and drivers of bird specimen number at regional scales.This study is the first attempt to examine the relationships between bird specimen number and species traits as well as climate niche breadth in China,aiming to answer two questions:1)how do species’temperature niche breadth and precipitation niche breadth influence specimen number?2)which trait is most associated with bird specimen number?The associations between bird specimen number and explanatory variables were examined using ordinary least squares,generalized linear models,phylogenetic generalized linear mixed models,and multiple comparisons.The results showed that Muscicapidae was the family with the highest specimen number,and Passeriformes was the order with the highest specimen number.Bird specimen number significantly increased with larger temperature niche breadth and precipitation niche breadth.Specimen number was also positively associated with geographic range size,habitat specificity,hunting vulnerability and clutch size,but negatively associated with body size.These findings suggest that future bird specimen collection should pay more attention to birds with limited ecological niches,large body sizes,and small clutch sizes.This research enhances the use of bird specimen data to study and preserve biodiversity.

Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China

Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.

Direct Pointwise Comparison of FE Predictions to StereoDIC Measurements:Developments and Validation Using Double Edge-Notched Tensile Specimen

To compare finite element analysis(FEA)predictions and stereovision digital image correlation(StereoDIC)strain measurements at the same spatial positions throughout a region of interest,a field comparison procedure is developed.The procedure includes(a)conversion of the finite element data into a triangular mesh,(b)selection of a common coordinate system,(c)determination of the rigid body transformation to place both measurements and FEA data in the same system and(d)interpolation of the FEA nodal information to the same spatial locations as the StereoDIC measurements using barycentric coordinates.For an aluminum Al-6061 double edge notched tensile specimen,FEA results are obtained using both the von Mises isotropic yield criterion and Hill’s quadratic anisotropic yield criterion,with the unknown Hill model parameters determined using full-field specimen strain measurements for the nominally plane stress specimen.Using Hill’s quadratic anisotropic yield criterion,the point-by-point comparison of experimentally based full-field strains and stresses to finite element predictions are shown to be in excellent agreement,confirming the effectiveness of the field comparison process.

Robotic natural orifice specimen extraction surgery I-type F method vs conventional robotic resection for lower rectal cancer

BACKGROUND Robotic resection using the natural orifice specimen extraction surgery I-type F method(R-NOSES I-F)is a novel minimally invasive surgical strategy for the treatment of lower rectal cancer.However,the current literature on this method is limited to case reports,and further investigation into its safety and feasibility is warranted.AIM To evaluate the safety and feasibility of R-NOSES I-F for the treatment of low rectal cancer.METHODS From September 2018 to February 2022,206 patients diagnosed with low rectal cancer at First Affiliated Hospital of Nanchang University were included in this retrospective analysis.Of these patients,22 underwent R-NOSES I-F surgery(RNOSES I-F group)and 76 underwent conventional robotic-assisted low rectal cancer resection(RLRC group).Clinicopathological data of all patients were collected and analyzed.Postoperative outcomes and prognoses were compared between the two groups.Statistical analysis was performed using SPSS software.RESULTS Patients in the R-NOSES I-F group had a significantly lower visual analog score for pain on postoperative day 1(1.7±0.7 vs 2.2±0.6,P=0.003)and shorter postoperative anal venting time(2.7±0.6 vs 3.5±0.7,P<0.001)than those in the RLRC group.There were no significant differences between the two groups in terms of sex,age,body mass index,tumor size,TNM stage,operative time,intrao-perative bleeding,postoperative complications,or inflammatory response(P>0.05).Postoperative anal and urinary functions,as assessed by Wexner,low anterior resection syndrome,and International Prostate Symptom Scale scores,were similar in both groups(P>0.05).Long-term follow-up revealed no significant differences in the rates of local recurrence and distant metastasis between the two groups(P>0.05).CONCLUSION R-NOSES I-F is a safe and effective minimally invasive procedure for the treatment of lower rectal cancer.It improves pain relief,promotes gastrointestinal function recovery,and helps avoid incision-related complications.

Energy-dispersive X-ray Spectroscopy for the Quantitative Analysis of Pyrite Thin Specimens

To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.

Statistical Analysis and Countermeasures for Specimen Rejection in the Emergency Department

The rejected specimens from the Emergency Department of the Center of Clinical Laboratory from January 1,2022 to January 1,2023 were analyzed to reduce the specimen rejection rates and to improve the quality of inspection.The results showed that there were 1488 samples of rejected specimens and the non-conforming rate was 0.58%.The departments involved were mainly the Emergency Department,the Hematology Department,the Cardiology Department,the Intensive Care Department,and the Brain Surgery Department.Among the reasons for rejection,blood hemolysis accounted for 43.15%,blood coagulation accounted for 26.61%,and the rate of insufficient specimens was 17.14%.Among them,the sample rejection rate for arterial blood gas analysis was the highest,which accounted for 1.74%;followed by specimens for coagulation test,which was 1.18%.These results indicate the main reason for producing rejected specimens is mainly due to not following the standard operating procedure.Specimen rejection can largely be avoided if the standards for specimen collection are strictly followed.

甲状腺结节大小对超声引导下细针穿刺活检标本质量影响的研究

本研究旨在评估甲状腺结节大小对超声引导下细针穿刺活检(US-FNAB)标本质量的影响。回顾性分析由同一名超声医生独立完成的614例共733个甲状腺结节US-FNAB患者资料,根据甲状腺结节直径分为A组(<5 mm)、B组(5~10 mm)和C组(>10 mm),比较各组间标本不满意率。A组189个结节,不满意率为11.6%(22/189);B组397个结节,不满意率为10.8%(43/397);C组147个结节,不满意率为9.5%(14/147)。三组间US-FNAB标本不满意率比较差异均无统计学意义(P>0.05)。对于一名具有丰富操作经验的医生,甲状腺结节大小不会影响US-FNAB的标本质量。

2015-2021年CHINET尿液分离菌分布和耐药性变迁

目的了解2015-2021年CHINET细菌耐药监测网中尿液分离菌的分布和耐药性。方法收集CHINET细菌耐药监测网51家医疗机构2015-2021年所有尿液标本临床分离菌的耐药监测数据资料,采用WHONET 5.6软件进行统计分析。结果2012-2021年尿液标本共分离细菌261893株,其中革兰阳性菌62219株,占23.8%,革兰阴性菌199674株占76.2%。常见的分离菌依次为大肠埃希菌(46.7%)、屎肠球菌(10.4%)、肺炎克雷伯菌(9.8%)、粪肠球菌(8.7%)、奇异变形杆菌(3.5%)、铜绿假单胞菌(3.4%)、无乳链球菌(2.6%)和阴沟肠杆菌(2.1%)。上述细菌主要分离自住院患者,女性多见于男性,成人多见于儿童。大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌中产超广谱β内酰胺酶(ESBL)菌株分别占53.2%、52.8%和37.0%。耐碳青霉烯类的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌中检出率分别为1.7%、18.5%、16.4%和40.3%。粪肠球菌对氨苄西林、呋喃妥因、利奈唑胺、万古霉素、替考拉宁和磷霉素的耐药率<10%,屎肠球菌对氨苄西林、左氧氟沙星、红霉素的耐药率>90%,对万古霉素、利奈唑胺和替考拉宁的耐药率<2%。ICU住院患者分离的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌对大部分抗菌药物的耐药率明显高于门诊患者和非ICU住院患者。结论尿液标本临床分离菌主要以大肠埃希菌、肠球菌和肺炎克雷伯菌为主,不同人群尿液标本中分离的细菌种类和耐药性不尽相同,应重视细菌耐药监测,减少抗菌药物的不合理使用。

类岩石试件三轴扰动破坏特性试验研究

为研究高应力围岩扰动破坏机制,开展了不同围压下类岩石试件的三轴常规压缩和三轴循环扰动试验,得到了试件的扰动应力–应变规律和变形破坏特征,并对试件开展了核磁共振(Nuclear Magnetic Resonance)成像试验,从微观角度进一步阐明了试件扰动破坏机理。研究结果表明:(1)试件在不同围压下均存在一个阈值强度,轴向荷载超过阈值强度后,轴向变形对扰动变得敏感,再次施加扰动会引起试件显著变形,当轴向荷载低于阈值强度时,变形对扰动不敏感。阈值强度与极限强度的比值可以反映试件的抗扰动能力,随着围压增大,该比值呈现逐步递减的规律,说明高围压下试件抗扰动能力下降,对扰动作用更敏感。(2)扰动作用下类岩石试件存在弱化效应,如常规三轴10MPa围压下试件表现出腰鼓破坏,而受扰动作用后,试件呈现斜切脆性破坏,与常规三轴5MPa围压下破坏形态相近。(3)岩石试件在高应力作用下进入塑性流动状态,内部颗粒重新排列,内部小孔隙与大孔隙的占比减少,而中孔隙的占比显著增多,试件内部孔隙率整体降低。

钢筋混凝土板柱节点冲切性能研究进展

为提高板柱节点冲切性能从而促进其工程应用,比较了各类抗冲切元件的不同布置形式、形状尺寸、几何参数以及组合形式对节点抗冲切承载力的影响,概括了受损板柱节点修复与加固的研究现状,梳理了不同开洞尺寸、距离、数量、形状及偏心荷载作用下开洞板柱试件抗冲切性能的研究成果,归纳了有无抗冲切钢筋和配置型钢剪力架板柱节点的抗冲切承载力计算方法以及基于机器学习的板柱节点冲切承载力预测方法。结果表明:各类抗冲切元件可通过改变布置形式、形状尺寸、几何参数以及元件组合从而改善板柱节点的冲切性能;板件开洞的尺寸越大、距离越远、数量越多,对节点的抗冲切性能越不利;基于数值模拟和规范改进得出的冲切承载力计算公式仅对特定试验有较高的预测精度,尚未形成较为统一的承载力计算公式,而基于机器学习的冲切承载力预测模型是未来研究的重点;需进一步开展关于受损板柱节点修复与加固方法的研究,对完善板柱节点抗冲切性能研究理论体系具有重要意义。

“双一流”背景下环境类专业课程思政教学路径探索

基于高校“双一流”建设的大背景,挖掘环境类专业课程中多种思政要素,提出以生态文明教育为载体,辅以思政教育特色的环境类专业教学内容框架,构建环境类专业核心及主干课程的课程思政融入点,并从“知识+能力+思政”三位一体的内容体系、线上线下混合教学模式、案例库建设等方面探索环境类专业课程思政教育教学的实践路径。

公安实践教学中数字化标本库的构建与应用

为推进信息化教学的发展,提出在公安实践教学中建设数字化标本库的构想。以虚拟仿真教学中的毒品数字化标本库构建与教学组织应用为例,探讨公安数字化标本库建设可持续发展的路径和内涵,提出适合公安特色数字化标本库内容和标准化建设的建议,采用资源利用、整合、共建等高效节约办法,注重数字化样本库和数据库同步开发使用的发展趋势。数字化标本库具有线上自学、线上线下教学、终身学习等优势,可启发公安教育智慧教学工作高质量发展。

昆虫实验教学标本数字化探索与实践

昆虫标本在昆虫学相关实验教学中发挥着重要作用,在实验教学中,昆虫实物标本在制作、保存以及管理等方面存在一定的不足。近年来,现代信息技术的快速发展为昆虫实验教学标本的建设提供了思路和方法,昆虫数字化标本顺应教育信息化的发展趋势,因具有诸多优势,受到教师和实验工作者的青睐。本文介绍了昆虫实物标本在实验教学中的重要性、昆虫实物标本存在的问题、昆虫数字化标本的优势以及在实验教学中的应用情况,为不断建设、完善和优化昆虫标本提供参考。

成组法疲劳试件个数选取方法研究

目的 在成组法疲劳试验过程中,确定最少疲劳试件个数判据,获取有效可靠的疲劳试验结果。方法基于疲劳可靠性的基本原理,在疲劳寿命对数正态分布的假设下,根据t分布理论,结合船舶及海洋工程一般构件具有95%置信度和可靠度p=97.72%下的P-S-N曲线的基本要求,推算出相应置信度和可靠度下5%误差限度内的疲劳试件个数与允许的最大变异系数数值的对应关系,以此作为成组法疲劳试验最少试件个数的判据,开展典型节点的疲劳试验。结果 得到了具有95%置信度的百位估计值Np,并通过线性相关系数r,判断对数疲劳应力Y=lg S与X=lg Np之间线性相关的程度,采用最小二乘法对对数疲劳寿命lg Np和对数疲劳应力lg S进行线性拟合,得到了具有95%置信度的P-S-N曲线,与IIW规范中相应的曲线一致。结论 文中给出的成组法疲劳试验个数确定方法是合理、可靠的,为船舶与海洋工程结构物典型焊接接头成组法疲劳试验个数的确定提供了依据。

一种新型转接半密闭式吸痰装置的设计与应用

吸痰是清除呼吸道分泌物和留取痰液标本的必要措施。传统吸痰装置包括开放式和密闭式两种。然而,开放式吸痰装置在操作过程中容易导致痰液喷溅,污染操作者及周围环境;密闭式吸痰装置的价格较开放式吸痰装置更高,虽可重复使用,但多次使用后其保护套与吸痰管壁之间的摩擦力增加,进而影响操作。上述两种吸痰方式在进行痰液标本留取时均需额外连接痰液收集器,这一过程容易造成标本泄露污染,同时增加患者感染风险。为了克服上述问题,大连医科大学附属第一医院重症医学科的医护人员设计了一种新型转接半密闭式吸痰装置,并获得了国家实用新型专利(专利号:ZL 202021564712.3)。该装置由吸引器连接口、滑动式负压开关、转接口、管身、透明薄膜保护套、夹片式连接头和痰液收集器组成。吸引器连接口处滑动式负压开关可实现单人单手操作;痰液收集器与吸痰装置转接口对接,做到标本留取无暴露;透明薄膜保护套覆盖吸痰管的管身,以确保吸痰操作全程无污染;夹片式连接头可与人工气道接口连接,避免吸痰过程中痰液喷溅,操作后即刻夹闭,减少环境污染。与现有吸痰装置相比,新型转接半密闭式吸痰装置设计更合理、成本更低廉,值得临床推广。

基于环境因素法和标准金属法的大气腐蚀性等级评价与分析

本文采用环境因素法和标准金属法对我国南海某地进行大气腐蚀性等级评价与分析,详细阐述了两种评价方法的分析过程,探讨了两种方法的特点,对比分析两种评价方法推测的结果。本文最后基于环境因素法和标准金属法测定结果定量评估了金属材料大气环境腐蚀性严酷程度,对评估某个地点的大气环境腐蚀性严酷程度,采取该地区使用产品采取相应防护措施具有重要意义。

钢管混凝土键连接框架梁和剪力墙的受剪性能

目的 研究钢管混凝土键连接框架梁和剪力墙的受剪性能,为工程应用提供设计依据。方法 应用有限元分析软件ABAQUS对比钢管混凝土键连接与现浇连接梁墙的结构受剪性能,分析前者受剪机理及不同因素对受剪性能的影响。结果 钢管混凝土键连接梁墙的结构承载力和延性系数较现浇结构分别提高约10%和34%;钢材强度从Q235到Q390,初始刚度增加8.44%;截面高度从100 mm到120 mm,延性系数提高17.73%;截面厚度每增加2 mm,承载力提高约15%;截面长度和混凝土强度等级对承载力、初始刚度和延性系数的影响均小于15%,纵向距离对其受剪性能几乎无影响。结论 采用钢管混凝土键连接梁墙的结构总体受剪性能优于现浇结构;钢材强度和截面厚度分别是影响初始刚度和承载力的主要因素。

临床生化检验标本溶血对肝肾功能、血脂和心肌标志物的影响及应对措施

目的探讨临床生化检验标本溶血对肝肾功能、血脂和心肌标志物的影响及应对措施。方法选择2021年3月至2022年9月接受生化检验的120例健康体检者,在晨起空腹状态下采集肘部静脉血10 mL作为检测标本,将每位体检者的血液标本均分为2份,分别设置为观察组与对照组。观察组血液样本经溶血处理后行临床生化检验,对照组血液样本未经溶血处理,直接行临床生化检验。比较两组健康体检者的肝功能、心肌标志物、肾功能及血脂指标。结果观察组的天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)及总蛋白(TP)水平明显高于对照组,差异具有统计学意义(P<0.05)。观察组的肌酸激酶同工酶MB(CK-MB)、肌酸激酶(CK)及N末端脑钠肽前体(NT-proBNP)水平明显高于对照组,差异具有统计学意义(P<0.05)。观察组的血尿素氮(BUN)、血清肌酐(Scr)及尿酸(UA)水平明显高于对照组,差异具有统计学意义(P<0.05)。观察组的甘油三酯(TG)、总胆固醇(TC)水平高于对照组,差异具有统计学意义(P<0.05);两组的高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平比较,差异无统计学意义(P>0.05)。结论临床生化检验血液标本发生溶血反应会影响肝肾功能、血脂、心肌标志物等检验项目的检测结果,易导致生化检验结果误差,临床诊疗工作中对此需充分重视,并制定一系列应对措施。

初始样本转移技术在老年骨折患者血培养采血中的应用效果分析

目的探讨没有指定设备或程序的情况下,初始样本转移技术降低老年骨折患者血培养污染率的效果。方法选取2019年1月至2023年3月在滕州市中心人民医院骨科住院的因疑似或确诊血流感染而需要采集血培养标本的400例老年骨折患者进行随机对照试验,采用随机数字表法将其分为对照组和观察组。对照组204例,男86例,女118例,年龄61~99(81.74±7.96)岁,上肢骨折72例,下肢骨折90例,脊柱骨折30例,骨盆髋臼骨折12例。观察组196例,男90例,女106例,年龄为60~94(80.36±8.23)岁,上肢骨折64例,下肢骨折88例,脊柱骨折34例,骨盆髋臼骨折10例。对照组采用标准方法采血,观察组采用初始样本转移技术采血。比较两组基线资料、血培养真阳性率和污染率,分析血培养物阳性的微生物学特征及各菌株的占比情况。统计学方法采用独立样本t检验、χ^(2)检验或Fisher确切概率法。结果两组患者血培养的真阳性率差异无统计学意义(χ^(2)=0.249,P>0.05)。观察组血培养污染率低于对照组[0.51%(1/196)比4.90%(10/204)],差异有统计学意义(χ^(2)=7.209,P<0.05)。两组污染血培养物中所分离的菌株中大部分为凝固酶阴性葡萄球菌,真正菌血症最常见的原因是肠杆菌科种属,其次是金黄色葡萄球菌。血培养污染患者比血培养阴性患者静脉注射万古霉素的比率高,差异有统计学意义(P<0.05)。血培养物污染患者额外抽取血培养物比率[63.64%(7/11)]比血培养阴性患者[23.77%(82/345)]高39.87%,差异统计学意义(χ^(2)=7.036,P<0.05)。血培养受污染患者的平均住院时间比血培养阴性患者长2.97 d(95%CI 1.5~3.0 d)。结论在不影响血培养真阳性的情况下,使用初始样本转移技术可以显著减少血培养污染,而且没有相关成本。这种新颖的方法作为一种简单、有效的措施,实用、安全,并且不会损害血培养的灵敏度,而无需使用昂贵的设备。