Rotor End Factors for 2-D FEA of Induction Motors with Smooth or Slitted Solid Rotor

Modifying the equivalent rotor resistivity with rotor end factor in 2-dimension(2-D)finite element analysis(FEA)is an effective way to analyze the 3-dimension(3-D)solid rotor problems.For the smooth solid rotor,five different rotor end factors are discussed and compared with each other.It is theoretically clarified that the resistivity of rotor in 2-D FEA should be multiplied by the square of rotor end factors to take the 3-D end effect of solid rotor into account.For the slitted solid rotor,an improved rotor end factor is proposed based on the equivalent area algorithm of eddy currents in rotor,since the end factors of smooth solid rotor are not applicable.Finally,the time-harmonic finite element method(FEM)combined with the rotor end factor is applied to analyze the performance of solid rotor induction motor.The tested and computed results are in good agreement,which proves the effectiveness of rotor end factor for the simplication of 3-D solid rotor problems.

Increased glycated basic fibroblast growth factor in diabetic skin reduces the cell viability and angiogenesis of human dermal microvascular endothelial cells

Objective To explore the glycation of basic fibroblast grow th factor( bFGF) in diabetic skin.Methods The abdom inal full-thickness skin tissues from 58 patients( 29 diabetic and 29 non-diabetic) aged 40 to69 years and granulation tissues from 15 patients( 8 diabetic and 7 non-diabetic) aged 50 to 59 were analyzed.The proportion of advanced glycation end products( AGEs)-b FG F intotal b FGF was measured with co-immunoprecipitation and the histological characteristics of wound skin were detected with hem atoxylin and eosin staining. The cell viability, apoptosis, and angiogenesis of human derm al m icrovascular endothelial cells( HDMECs) after exposure to AG Es-b FG For bFGF were measured with cell counting kit-8, flow cytom etry,and tube form ation assay, respectively. Results The proportion of AG Es-b FG F in total b FG F showed agedependent increaseboth in diabetic and non-diabetic skin. As com pared with non-diabetic skin, the constituent ratio in diabetic skin increased significantly in the equal age-group, and the same result could be obtained in granulation tissues from patients aged 50 to 59. The proportion of AG Es-b FG F in diabetic granulation was low er than that in diabetic skin from patients aged 50 to 59. H istological analysis show ed few er vessels in diabetic skin wound. In vitro, the viability and vascularization of H D M EC s were promoted by b FG F and inhibited after exposure to AGEs-bFGF for 7d. Conclusion The present study indicates that one cause for im paired wound healing in diabetic skin could be the glycated b FG F and its changed angiogenic function.

HEPATOCYTE GROWTH FACTOR PROTECTS AGAINST APOPTOSIS INDUCED BY ADVANCED GLYCATION END PRODUCTS IN ENDOTHELIAL CELLS

Objective To investigate the effects of hepatocyte growth factor(HGF)on vascular endothelial cells apoptosis induced by advanced glycation end products(AGEs)and its possible mechanism. Methods Human umbilical vein endothelial cells(HUVECs)were cultured in vitro and intervened by different concentrations of AGEs and HGF.The cell inhibitory rates of each group with different culture time(12, 24, 48, and 72 hours)were measured by methyl thiazolyl tetrazolium(MTT)assay. The early stage apoptosis was detected by flow cytometry with Annexin V-FITC/PI double staining, morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the expression of apoptosis-associated genes Bax and Bcl-2 were determined by Western blotting.The activity of caspase-3 was detected by enzyme-linked immunosorbent assay (ELISA).Results Morphological observation indicated that high concentration of AGEs induced characteristic apoptotic changes in HUVECs.Within a certain concentration range, HUVECs apoptosis inducing rates by AGEs were in both dose- and time-dependent manners.HGF significantly inhibited the apoptosis of HUVECs induced by AGEs (P< 0.05).AGEs significantly promoted expression of Bax protein, but not Bcl-2.Whereas HGF significantly promoted the expression of Bcl-2(P<0.01)and decreased the activity of caspase-3(P<0.05)without affecting Bax level.Conclusions AGEs can induce the apoptosis of endothelial cells in vitro.HGF may effectively attenuate AGEs-induced endothelial cells apoptosis through upregulating Bcl-2 gene expression and inhibiting caspase-3 activation.

Autophagy plays a protective role in advanced glycation end products-induced apoptosis of chondrocytes via regulation of tumor necrosis factor-α,nuclear factor-κ B and reactive oxygen species

Objective: To study the adverse effects of advanced glycation end products(AGEs) on chondrocytes and the role of autophagy in this process. Methods: Chondrocytes were harvested from the human articular cartilage tissues in surgery. AGEs were administered during chondrocytes culture. The rapamycin was used to induce autophagy. The cell viability was determined by 3-[4,5-dimethylthiazol2-yl]-2,5-diphenyl tetrazolium bromide(MTT) assay.The expression of tumor necrosis factor-α(TNF-α) and nuclear factor-κ B(NF-κ B) was detected by quantitative real-time polymerase chain reaction. The reactive oxygen species(ROS) production and apoptosis of the chondrocytes were determined by fluorescent probe and flow cytometer, respectively. Results: The chondrocytes viability was significantly reduced after 12 h incubation with AGEs(P<0.01)). In contrast, rapamycin pretreatment increased the chondrocytes viability through autophagy. AGEs increased TNF-α and NF-κ B mRNA expression of chondrocytes and autophagy receded or proceeded the change. AGEs increased intracellular ROS accumulation and autophagy reversed the change. AGEs accelerated chondrocytes apoptosis and autophagy suspended apoptosis. Conclusions: Accumulation of AGEs may have an adverse role for chondrocytes by increasing TNF-α and NF-κB expression, ROS accumulation and apoptosis; meanwhile, autophagy ameliorates the AGEsinduced adverse effects.

Association of vascular endothelial growth factor-634G/C and receptor for advanced glycation end products G82S gene polymorphisms with diabetic retinopathy

AIMTo investigate the association of receptor for advanced glycation end products (RAGE) G82S and vascular endothelial growth factor (VEGF) -634 G/C gene polymorphisms with diabetic retinopathy (DR).METHODSOur cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy (PDR), 15 had non proliferative diabetic retinopathy (NPDR), 34 had no diabetic retinopathy (NDR) and 61 healthy controls. Participants were tested for RAGE G82S and VEGF -634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTSWe found a significant association between VEGF -634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF -634 CC genotype compared to NDR patients [odds ratio for CC vs (GC+GG)=6.5, 95% CI=1.5-27.8, P=0.021]. Also VEGF -634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study (P=0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype (P=0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSIONPatients carrying VEGF -634 C polymorphism have a higher risk of PDR development, so VEGF -634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.

Factors Relating to Nurses’ End-of-Life Care

This integrative review aimed to investigate factors relating to end-of-life care of nurses. The review was conducted according to PICo (Participant, area of Interest, and Context). Keywords identified were: “nurse” AND “end-of-life care” (“dyingcare” OR “‘deathcare”, OR “near end stage of life care” OR “palliative care” OR “hospice care” OR “comfortable care in near death” OR “quality of dying patients care”), AND “nurses”. The database searched through PubMed, ProQuest, Google Scholar, Web of Science and SCOPUS. The searching inclusion criteria were limited to English and Chinese language studies about nurses’ end-of-life care from 2010 to 2019, yielding 258 English language articles and 2Chinese language articles. Results: A total of fifteen articles were selected based on inclusion criteria. Two subjects were obtained from the results that related to nurses’ care during the process of end of life: 1) Nurses’ demographic factors;and 2) Modifiable factors. Nurses’ demographic factors were age, years of work experience, level of education and experience of the death of a family member/friend. Modifiable factors included knowledge, attitude, confidence, relationship, environment and resources, communication, nursing activities, philosophy and culture of care, skills and training. These factors were explored in various areas and majority of the studies had been conducted in public government hospitals. Conclusion: The major power ability of care was observed in nurses who acted the significant part in caring for the terminally ill during the dying process. Caring for dying patients was related to many factors which could affect the fabric of nursing care at the end stage of life. The elements found in this review could lead to recommendations with implications for nursing practice so as to improve and enhance end-of-life care. Some factors could be considered like predictors affecting nursing practice for chronical ill patients in further research. In addition, nurses’ tranquility care in community hospitals should be more focused.

基于因子图优化的激光惯性SLAM方法研究

融合激光雷达和惯性测量单元的SLAM方法是拒止环境下自动驾驶定位建图的重要技术手段。该技术包含前端和后端2个数据处理模块,在后端数据处理方面,现有方法存在长时间运行时累积误差较高、回环检测计算负载较大以及复杂拒止环境下鲁棒性不理想等问题。针对上述需求,提出一种适配前端激光惯性里程计的新型后端数据处理方法。该方法采用因子图优化算法架构,建立激光连续关键帧间的惯性单元预积分模型,将该模型作为因子图架构中表征惯性单元数据的算法因子,降低数据处理的计算负载。构建基于Scan-Context描述符的高效回环检测方法,将点云数据三维空间结构特征转化为二维特征图,在保证回环检测精度的前提下进一步提高计算效率。结合前端里程计信息,构建包含里程计因子、惯性单元预积分因子和回环检测因子误差项的目标函数,通过非线性优化算法求解最优位姿状态,形成完整的SLAM算法结构。对所述方法及FAST-LIO2、LIO-SAM和SC-LeGO-LOAM等现有主流激光惯性SLAM方法基于开源数据集进行对比验证,并开展实车试验。结果表明:相较于现有方法,所述DSC-Algo方法在公开数据集测试中的计算性能和全局定位精度实现了显著提升,在现实拒止环境实车测试中的定位精度和算法鲁棒性也具有明显优势。

谷胱甘肽联合西地那非治疗勃起功能障碍患者临床疗效及对血管内皮功能的影响

目的探究谷胱甘肽联合西地那非治疗勃起功能障碍(ED)患者临床疗效及对血管内皮功能、炎性因子、勃起功能的影响。方法选取2022年10月—2023年10月新疆维吾尔自治区人民医院泌尿中心诊治ED患者89例作为研究对象,随机数字表法分为单药组44例和联合组45例。单药组给予西地那非口服治疗,联合组在单药组基础上给予还原型谷胱甘肽片口服治疗,2组患者均连续治疗1个月。观察2组患者治疗前、治疗结束时及治疗后1个月的血管内皮功能(NO、ET、VEGF、ES)、炎性因子(hs-CRP、IL-6、IL-8、IL-10)、勃起功能(IIEF-5、QEQ、EHS、PSV)变化,比较2组临床疗效、不良事件发生率。结果治疗结束后1个月,联合组临床治疗总有效率为91.11%,高于单药组的75.00%(χ^(2)/P=4.121/0.042);治疗结束时及治疗结束后1个月,联合组患者血清NO、VEGF水平显著高于单药组,ET水平显著低于单药组(治疗结束时:t/P=5.323/<0.001,3.808/<0.001,3.683/<0.001;治疗结束后1个月:t/P=2.615/0.011,3.197/0.002,3.089/0.003);血清hs-CRP、IL-6水平显著低于单药组(治疗结束时:t/P=8.323/<0.001,2.364/0.020;治疗结束后1个月:t/P=6.787/<0.001,2.662/0.009);IIEF-5、QEQ、EHS及PSV均显著高于治疗前,其中EHS及PSV也显著高于单药组(治疗结束时:t/P=6.410/<0.001,4.066/<0.001;治疗结束后1个月:t/P=8.928/<0.001,4.532/<0.001);2组患者不良事件发生率比较差异无统计学意义(P>0.05)。结论谷胱甘肽联合西地那非能够有效改善ED患者血管内皮功能及勃起功能,同时显著降低患者炎性因子水平,且对于ED患者具有显著临床疗效及安全性。

框架结构梁柱抗震内力调整研究

框架梁端剪力调整之前,应先计算控制截面内力,后进行梁端弯矩调幅,使结构更加安全。框架结构梁柱抗震内力调整在手算一榀框架计算中是一个难点,且容易出错。为解决这一问题,可根据具体计算实例,归纳出框架梁柱抗震内力调整计算的基本步骤和方法,计算出在框架梁端弯矩正负号判别、弯矩最不利组合、最大剪力设计值确定等位置容易出现错误,并结合实例予以纠正。框架柱的抗震内力调整顺序是先进行“强柱弱梁”的调整,再进行“强剪弱弯”的调整,中柱在进行“强柱弱梁”的内力调整时,因其需要同时考虑节点左右梁端的弯矩,节点上下柱的线刚度,计算量大,采用柱端弯矩增大系数的简化计算方法,简单明了,误差很小,对边柱同样适用。

医护人员的临终关怀态度和安宁疗护行为调查

目的 了解临床医护人员临终关怀态度与安宁疗护行为现况,探讨安宁疗护行为的影响因素。方法 采用临终关怀态度调查量表和安宁疗护行为测量量表对425名临床医护人员进行调查。结果 临床医护人员安宁疗护行为得分为(48.00±10.14)分,显著低于安宁疗护机构医护人员(P<0.05);临终关怀态度得分为(103.72±10.70)分。临终关怀态度与安宁疗护行为呈正相关(P<0.05)。分层回归分析结果显示,男性、已婚以及接受过临终关怀教育的医护人员安宁疗护行为水平较高;临终关怀态度中以患者及其家属为中心的照顾意识维度能独立解释安宁疗护行为总变异的11.6%。结论 临床医护人员临终关怀态度总体偏正向,安宁疗护行为有待进一步提升,临终关怀态度对安宁疗护行为具有重要的促进作用。医院应通过开展专业培训,提升医护人员安宁疗护行为能力。

单中心维持性血液透析与腹膜透析患者生存率比较及影响因素

目的 探讨终末期肾脏病(ESRD)患者血液透析(HD)或腹膜透析(PD)治疗的生存差异及影响因素。方法 纳入2016年3月1日—2022年3月1日在我院行HD或PD治疗并长期随访的ESRD患者156例,其中HD 87例(HD组),PD 69例(PD组)。记录患者性别、年龄、体重、血压、尿量、原发病、血红蛋白、白蛋白、N端脑钠肽前体(NT-proBNP)、甲状旁腺激素(PTH)、残余肾功能、血肌酐、血尿素氮,观察终点事件为全因死亡。生存分析采用Kaplan-Meier分析,生存率比较采用log-rank检验。各因素对生存的影响采用多因素Cox回归风险分析。结果 两组患者性别、年龄、体重、尿量、原发病、血压、血红蛋白、白蛋白、NT-proBNP、PTH、残余肾功能、血肌酐、血尿素氮比较差异均无统计学意义(P>0.05)。HD组和PD组中位生存时间分别为36.0月、42.0月;HD组和PD组1、2、3、4、5年生存率分别为87.3%、80.5%、54%、39.1%、34.5%和86.9%、69.6%、55.1%、29%、24.6%。Log-rank检验显示两组患者生存率比较差异无统计学意义(χ^(2)=0.049,P=0.826)。多因素COX回归分析提示年龄、体重、高血压、NT-proBNP及PTH是终末期肾病患者生存率的影响因素(P=0.010、0.004、0.012、0.003、0.006)。年龄、体重、高血压及血红蛋白是HD组患者生存率的影响因素(P=0.002、0.027、0.023、0.011)。年龄、体重、尿量、血红蛋白及PTH是PD组患者生存率的影响因素(P=0.005、0.067、0.009、0.046、0.018)。结论 终末期肾病患者HD和PD治疗5年生存率比较无明显差异,年龄、体重、高血压、NT-proBNP及PTH是维持性透析患者生存率主要影响因素;HD患者年龄、体重、高血压及血红蛋白含量是生存率主要影响因素;而PD患者年龄、体重、尿量、血红蛋白含量及PTH是生存率主要影响因素。

输卵管部分切除术联合端端吻合术影响患者输卵管通畅性和妊娠的相关因素分析

目的:探讨输卵管部分切除术联合端端吻合术后影响患者输卵管通畅性和妊娠的风险因素。方法:选取2020年1月至2023年4月郑州市妇幼保健院300例输卵管妊娠患者,所有患者均行输卵管部分切除术联合端端吻合术,并于术后行子宫输卵管造影检查。对患者术后输卵管的通畅性进行统计分析,并采用Lasso-Logistic回归分析术后输卵管通畅性的风险因素,Spearman相关性分析法分析各风险因素与术后妊娠的关系。结果:300例患者中输卵管通畅225例(通畅组),输卵管通而不畅54例及输卵管堵塞21例(不通畅组)。单因素分析结果显示,年龄、输卵管孕囊直径、输卵管妊娠部位、手术时机、盆腔粘连、吻合术方式、剩余输卵管长度、盆腔手术史、术中电凝输卵管部位的次数(以下简称术中电凝次数)、术中出血量、手术医生工作年限是术后输卵管通畅性的影响因素(均P<0.01);Lasso回归分析进一步筛选出7个影响因素:输卵管妊娠部位、盆腔粘连、吻合术方式、剩余输卵管长度、盆腔手术史、术中电凝次数、手术医生工作年限;Logistic回归分析结果显示,输卵管峡部妊娠、盆腔粘连、开腹吻合术、盆腔手术史、术中电凝次数是术后输卵管通畅性的独立危险因素,剩余输卵管长度、手术医生工作年限是术后输卵管通畅性的独立保护因素(均P<0.01)。研究随访1年,失访5例。295例患者中,术后1年妊娠192例(65.08%),其中宫内妊娠172例(89.58%),异位妊娠20例(10.42%)。Spearman相关性分析结果显示,输卵管峡部妊娠、盆腔粘连、开腹吻合术、盆腔手术史、术中电凝次数与术后妊娠呈负相关,剩余输卵管长度、手术医生工作年限与术后妊娠呈正相关(均P<0.01)。结论:输卵管峡部妊娠、盆腔粘连、开腹吻合术、盆腔手术史、术中电凝次数是影响输卵管部分切除术联合端端吻合术后患者输卵管通畅性的独立危险因素,且与术后妊娠呈负相关;剩余输卵管长度、手术医生工作年限是影响输卵管部分切除术联合端端吻合术后患者输卵管通畅性的独立保护因素,且与术后妊娠呈正相关。

锆合金管塞结构压力电阻焊接头的应力集中系数及影响因素

采用Abaqus有限元分析软件建立了锆合金管塞结构压力电阻焊接模型与应力集中系数计算模型,通过与热模拟试验得到的挤出金属高度进行对比,对焊接模型进行验证,模拟分析了内部挤出金属过渡角、端塞行进量和包壳管内壁倒角对接头应力集中系数的影响。结果表明:内部挤出金属高度模拟结果和试验结果的相对误差为9.58%,外部挤出金属高度的相对误差为6.65%,说明建立的焊接模型准确;随着内部挤出金属过渡角增加,接头应力集中系数先降低,当过渡角增大至60°后增加,增大至120°时又下降;随着端塞行进量的增加,内部挤出金属过渡角降低,应力集中系数增加,接头熔合线长度增大;与未倒角接头相比,包壳管内壁倒角深度不大于0.50 mm时应力集中系数降低,最大降低了16.00%,倒角深度大于0.50 mm时应力集中系数增大,最大提高了91.49%。

腹膜透析与高通量血液透析治疗终末期肾病患者的效果比较

目的:比较腹膜透析与高通量血液透析治疗终末期肾病患者的效果。方法:回顾性分析2021年1月至2023年6月该院收治的70例终末期肾病患者的临床资料,按治疗方式不同将其分为对照组与观察组各35例。对照组采用高通量血液透析治疗,观察组采用腹膜透析治疗。比较两组治疗前后肾功能指标[血尿素氮(BUN)、血肌酐(Scr)、肾小球滤过率(GFR)、β_(2)-微球蛋白(β_(2)-MG)]水平、炎性因子[肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、超敏C反应蛋白(hs-CRP)]水平、T细胞亚群指标(CD4^(+)、CD3^(+)、CD8^(+)、CD4^(+)/CD8^(+))水平和并发症发生率。结果:治疗后,两组BUN、Scr、β_(2)-MG水平均低于治疗前,且观察组低于对照组,两组GFR水平均高于治疗前,且观察组高于对照组,差异有统计学意义(P<0.05);两组TNF-α、IL-6、hs-CRP水平均低于治疗前,且观察组低于对照组,差异有统计学意义(P<0.05);两组CD4^(+)、CD3^(+)、CD4^(+)/CD8^(+)+水平均高于治疗前,且观察组高于对照组,两组CD8水平均低于治疗前,且观察组低于对照组,差异有统计学意义(P<0.05);两组并发症发生率比较,差异无统计学意义(P>0.05)。结论:腹膜透析治疗终末期肾病患者可改善肾功能指标和T细胞亚群指标水平,降低炎性因子水平,其效果优于高通量血液透析治疗。

乳腺癌共发甲状腺癌的危险因素及预后分析

目的分析乳腺癌(BC)共发甲状腺癌(TC)的危险因素,探讨预后影响因素。方法在2020年监测、流行病学和结果(SEER)数据库搜集BC共发TC患者(共发组)以及单纯BC患者(单纯组)的信息,比较2组临床资料和生存信息。回顾性分析某医院住院的BC共发TC患者(共发组A)以及单纯BC患者(单纯组A)的临床资料,比较2组临床资料以及生存信息。结果①SEER数据库分析,共发组482例、单纯组500例,单因素分析显示首次确诊年龄和孕激素受体(PR)是BC共发TC的危险因素(P均<0.05),多因素分析显示首次确诊年龄(OR=1.800,95%CI:1.387~2.337,P<0.001)、PR(OR=1.364,95%CI:1.023~1.818,P=0.034)是BC共发TC的独立危险因素。剔除随访资料不完整者后的单因素分析显示肿瘤直径和PR是BC共发TC的预后因素(P<0.05),多因素分析显示肿瘤直径是BC共发TC的独立预后因素(OR=4.328,95%CI:1.410~13.288,P=0.010);单因素分析显示首次确诊年龄和肿瘤直径是单纯BC的预后因素(P均<0.05),多因素分析显示首次确诊年龄(OR=2.443,95%CI:1.014~5.889,P=0.047)、肿瘤直径(OR=2.030,95%CI:1.039~3.969,P=0.038)是单纯BC的独立预后因素。②某医院住院患者分析,共发组A 40例(50%),单纯组A 40例(50%)。单因素分析显示月经情况、PR、增殖指数Ki-67、TT_(3)是BC共发TC的危险因素(P<0.05);多因素分析显示月经情况(OR=0.175,95%CI:0.052~0.591,P=0.005)、PR(OR=5.686,95%CI:1.677~19.282,P=0.005)、Ki-67(OR=3.966,95%CI:1.133~13.875,P=0.031)是BC共发TC的独立危险因素。对80例患者进行随访,共发组A死亡6例,生存27例,失访7例;单纯组A死亡2例,生存29例,失访9例。2组患者Cox回归分析结果均无统计学意义(P均>0.05)。结论首次确诊年龄、月经情况、PR、Ki-67是BC共发TC的危险因素。肿瘤直径是BC共发TC的独立预后因素。首次确诊年龄和肿瘤直径是单纯BC的独立预后因素。

超深基坑吊脚桩局部稳定性分析

目前基坑设计中对于吊脚桩预留岩肩的宽度和支护桩的嵌固深度取值大多从对上部支护结构内力及变形的影响角度出发,往往忽略了支护结构底部附近的局部稳定性问题。依托珠江三角洲水资源配置工程超深竖井项目,提出了外倾结构面下或破碎岩体吊脚桩基坑可能存在的3种破坏模式,采用极限平衡法分别给出了不同破坏模式下稳定安全系数的计算方法。同时针对不同破坏模式下,影响稳定安全系数的参数如岩层的埋深、结构面的倾角和力学参数、岩肩宽度、岩肩深度等进行了分析,结果表明外倾结构面倾角、结构面或岩体的力学参数对稳定安全系数影响较大。研究成果可为类似工程提供参考。

广义圆端形钢管混凝土短柱轴压承载力公式

为研究圆形、圆端形、变圆心角圆端形和矩形钢管混凝土短柱轴压承载力的统一计算公式,采用两种不同本构关系建立广义圆端形钢管混凝土轴压短柱的ABAQUS有限元模型,利用90个钢管混凝土短柱轴压试验数据与有限元计算结果进行对比,验证了有限元模型的可靠性。通过改变构件的截面形状和材料强度,设置了9组共90个广义圆端形钢管混凝土轴压短柱有限元模型。对有限元计算结果展开参数分析,研究截面平直段高宽比和截面圆心角对钢管混凝土约束效应的影响。基于统一理论和约束分区方法,以截面形状影响系数对套箍系数进行了修正,并在GB 50936—2014推荐的圆形钢管混凝土短柱轴压承载力公式的基础上,建立了广义圆端形钢管混凝土短柱的轴压承载力简化计算公式,最后采用452个广义圆端形钢管混凝土短柱轴压试验数据对公式的准确性进行了验证。结果表明:当材料强度和含钢率一定时,广义圆端形钢管混凝土柱的套箍约束效应随着截面平直段高宽比的增大而减小,随着截面圆心角的增大而增大;简化公式的计算结果与试验结果吻合良好,适用于圆形、圆端形、变圆心角圆端形及矩形钢管混凝土短柱的轴压承载力计算。

两端简支GFRP管-钢骨混凝土构件抗侧向冲击性能有限元分析

目的 研究两端简支GFRP管-钢骨混凝土构件的抗侧向冲击性能,为该类构件的工程应用提供参考。方法 建立并验证侧向冲击荷载作用下两端简支GFRP管-钢骨混凝土构件有限元模型,分析了典型构件在侧向冲击荷载作用下的全过程、破坏形态、应力发展、相互作用力时程曲线和弯矩时程曲线等动态响应;研究了冲击能量、冲击冲量、钢材强度、GFRP管厚度以及截面含钢率对构件抗冲击性能的影响。结果 随着冲击能量及冲量的增大,冲击持时和构件弯曲变形增大;提高钢材强度、GFRP管厚度可以改善构件的抗冲击性能。结论 GFRP管对混凝土有较好的约束作用,构件在侧向冲击荷载作用下整体发生弯曲破坏,内部钢骨塑性变形发展充分,构件抗侧向冲击性能优越。

体外膜肺氧合辅助肺移植术治疗对终末期肺病患者预后的影响及相关因素分析

目的探讨体外膜肺氧合(ECMO)辅助肺移植术治疗对终末期肺病患者预后的影响及相关因素。方法回顾性分析2020年4月至2022年6月我院开展的87例ECMO辅助肺移植术治疗的终末期肺病患者,其中44例行静脉-动脉(V-A)转流为VA-ECMO组,43例行静脉-静脉(V-V)转流为VV-ECMO组,比较两组患者临床资料、手术相关指标、术后并发症及预后,分析影响终末期肺病患者预后的危险因素。结果VA-ECMO组平均肺动脉压及重度动脉压占比显著高于VV-ECMO组(P<0.05);手术时间显著高于VV-ECMO组,ECMO流转时间显著低于VV-ECMO组(P<0.05);两组术后PGD率、术后72 h内休克率、再次气管插管或气管切开率、术后6个月生存率比较,差异无统计学意义(P>0.05);多因素Logistic回归分析显示,肺动脉压、ECMO转流时间、术后PGD、再次气管插管或气管切开是影响终末期肺病患者预后的危险因素(P<0.05)。结论ECMO辅助肺移植术治疗终末期肺病采用V-A转流和V-V转流患者短期预后比较无显著性差异,而肺动脉压、ECMO转流时间、术后PGD、再次气管插管或气管切开是影响终末期肺病患者预后的危险因素。

癌症终末期病人尊严研究现状

对国内外癌症终末期病人尊严的概念及内涵、测量工具、现状水平、影响因素及干预措施进行综述,旨在为我国癌症终末期病人尊严研究提供理论依据及实践基础。