基于eNSP、VirtualBox和Kali的DHCP多层次闯关实验设计

动态主机配置协议(DHCP)是管理和分配IP地址的协议,在企业网中广泛使用。针对学生在学习过程中缺乏动手实践能力的训练以及计算机网络设备硬件有限的问题,提出了一种综合使用eNSP、VirtualBox、Kali软件搭建DHCP多层次实验项目。实验项目的设计涵盖了常见DHCP服务器的配置、DHCP中继、DHCP攻击与防御方面的内容。通过本实验项目的设计能够提升学生的网络工程实践能力,方便教师开展线上教学,提升教学质量。

High formability Mg-Zn-Gd wire facilitates ACL reconstruction via its swift degradation to accelerate intra-tunnel endochondral ossification

After reconstructing the anterior cruciate ligament(ACL),unsatisfactory bone tendon interface healing may often induce tunnel enlargement at the early healing stage.With good biological features and high formability,Magnesium-Zinc-Gadolinium(ZG21)wires are developed to bunch the tendon graft for matching the bone tunnel during transplantation.Microstructure,tensile strength,degradation,and cytotoxicity of ZG21 wire are evaluated.The rabbit model is used for assessing the biological effects of ZG21 wire by Micro-CT,histology,and mechanical test.The SEM/EDS,immunochemistry,and in vitro assessments are performed to investigate the underlying mechanism.Material tests demonstrate the high formability of ZG21 wire as surgical suture.Micro-CT shows ZG21 wire degradation accelerates tunnel bone formation,and histologically with earlier and more fibrocartilage regeneration at the healing interface.The mechanical test shows higher ultimate load in the ZG21 group.The SEM/EDS presents ZG21 wire degradation triggered calcium phosphate(Ca-P)deposition.IHC results demonstrate upregulation of Wnt3a,BMP2,and VEGF at the early phase and TGFβ3 and Type II collagen at the late phase of healing.In vitro tests also confirmed the Ca-P in the metal extract could elevate the expression of Wnt3a,βcatenin,ocn and opn to stimulate osteogenesis.Ex vivo tests of clinical samples indicated suturing with ZG21 wire did not weaken the ultimate loading of human tendon tissue.In conclusion,the ZG21 wire is feasible for tendon graft bunching.Its degradation products accelerated intra-tunnel endochondral ossification at the early healing stage and therefore enhanced bone-tendon interface healing in ACL reconstruction.

A linkable signature scheme supporting batch verification for privacy protection in crowd-sensing

The maturity of 5G technology has enabled crowd-sensing services to collect multimedia data over wireless network,so it has promoted the applications of crowd-sensing services in different fields,but also brings more privacy security challenges,the most commom which is privacy leakage.As a privacy protection technology combining data integrity check and identity anonymity,ring signature is widely used in the field of privacy protection.However,introducing signature technology leads to additional signature verification overhead.In the scenario of crowd-sensing,the existing signature schemes have low efficiency in multi-signature verification.Therefore,it is necessary to design an efficient multi-signature verification scheme while ensuring security.In this paper,a batch-verifiable signature scheme is proposed based on the crowd-sensing background,which supports the sensing platform to verify the uploaded multiple signature data efficiently,so as to overcoming the defects of the traditional signature scheme in multi-signature verification.In our proposal,a method for linking homologous data was presented,which was valuable for incentive mechanism and data analysis.Simulation results showed that the proposed scheme has good performance in terms of security and efficiency in crowd-sensing applications with a large number of users and data.

Outstanding proton conductivity over wide temperature and humidity ranges and enhanced mechanical, thermal stabilities for surface-modified MIL-101-Cr-NH2/Nafion composite membranes

High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH2(PCP-MCN),a kind of hybrid metal-organic framework,which exhibits a superior proton conductivity.PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes.Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated.Significant enhancement in proton conduction for PCP-MCN around 55℃ is interestingly found due to the thermal motion of the PCP molecular chains.Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains,i.e.,the formation of substantial acid–base pairs(-SO_(3)^(-)…^(+)H–NH-),which further improves compatibility between additive and Nafion matrix.At the same humidity and temperature condition,the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion.Proton conductivity(σ)over wide ranges of humidities(30-100%RH at 25℃)and temperatures(30-98℃ at 100%RH)for prepared membranes is measured.The s in PCPMCN/Nafion composite membranes is remarkably enhanced,i.e.0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98℃ and 100%RH,because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation–deprotonation processes.The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN.In particular,when 3 wt.%PCP-MCN was added to Nafion,the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480,1.098 W/cm^(2) under 40%RH,100%RH at 60℃,respectively,guaranteeing it to be a promising proton exchange membrane.

Synthesis of NO by rotating sliding arc discharge reactor with conical-spiral electrodes

The present work investigates the potential applications of nitrogen oxides(NO_(x)),particularly nitric oxide(NO)and nitrogen dioxide(NO_(2)),generated through discharge plasma in diverse sectors such as medicine,nitrogen fixation,energy,and environmental protection.In this study,a rotating sliding arc discharge reactor was initially employed to produce high concentrations of gaseous NO_(x),followed by the utilization of a molybdenum wire redox reactor for NO_(2)-to-NO conversion.The outcomes reveal that the discharge states and generations of NO_(x) are affected by varying parameters,including the applied energies,frequencies and airflow states(1.3-2.6 m/s are the laminar flow,2.6-5.2 m/s are the transition state,5.2-6.5 m/s are the turbulent flow),and the concentrations of NO_(x) within the arc discharge are higher than that in the spark discharge.Moreover,the concentrations of NO,NO_(2) and NO_(x) gradually increased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) decreased with increasing the applied energy for one cycle from 14.8 mJ to 24.3 mJ.Meanwhile,the concentrations of NO,NO_(2) and NO_(x) gradually decreased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) first decreased and then increased with increasing the applied frequencies from 5.0 kHz to 9.0 kHz.Further,the concentrations of NO,NO_(2) and NO_(x) gradually decreased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) first increased and then decreased with increasing the air flow speeds from 1.3 m/s to 6.5 m/s.Lastly,the concentrations of NO increased and NO_(2) decreased with increasing temperature from 25℃ to 400℃ using molybdenum converted.These findings provide experimental support for the application of plasma in the fields of medicine,nitrogen fixation,energy and environmental protection.

Effect of vinegar supplementation on patients with esophageal lesions lightly stained with Lugol’s iodine solution:Prospective single-centre trial

BACKGROUND Esophageal chromoendoscopy with iodine solution is important for detecting early esophageal cancer.The effect of routine treatment for lesions lightly stained with Lugol’s iodine solution is limited,and the addition of natural substances to a regular diet is becoming increasingly common.Vinegar has antitumor effects as reported in previous studies.AIM To evaluate whether vinegar supplementation could improve the prognosis of patients with lightly stained esophageal lesions.METHODSThis prospective single-centre trial included consecutive patients with lightly stained lesions between June 2020 and April 2022.Patients in the experimental group received increased amounts of vinegar for 6 months.The primary outcome of the study was the clinical therapeutic effect.Complications related to vinegar ingestion and adverse events were also recorded in detail.RESULTS A total of 166 patients were included in the final analysis.There was no significant difference in the baseline data between the two groups.Intention-to-treat(ITT)analysis demonstrated that the rates at which endoscopic characteristics improved were 33.72%in the experimental group and 20.00%in the conventional group(P=0.007);and the rates at which biopsy pathology improved were 19.77%and 8.75%,respectively(P=0.011).Additional vinegar consumption had a statistically protective effect on the rate at which endoscopic characteristics improved[hazard ratio(HR)_(ITT)=2.183,95%CI:1.183-4.028;HR_(per-protocol(PP))=2.307,95%CI:1.202-4.426]and biopsy pathology improved(HR_(ITT)=2.931,95%CI:1.212-7.089;HR_(PP)=3.320,95%CI:1.295-8.507).No statistically significant effect of increased vinegar consumption on preventing high-grade intraepithelial neoplasia or early cancer was observed(HR_(ITT)=0.382,95%CI:0.079-1.846;HRPP=0.382,95%CI:0.079-1.846).The subgroup analyses indicated that the overall therapeutic improvement of endoscopic characteristics and biopsy pathology seemed more obvious in older(age>60)male patients with small lesions(lesion size≤0.5 cm).Three patients in the experimental group reported acid regurgitation and heartburn.No adverse event during gastroscopy were recorded during follow-up.CONCLUSION A moderately increased ingestion of vinegar could not directly reduce the risk of esophageal cancer in the mucosa dysplasia population,but it improved the endoscopic characteristics and ameliorated the biopsy pathology to a certain extent.Further research is needed to verify the effect of nutritional intervention on precancerous esophageal lesions.

Applications of Metal–Organic Frameworks and Their Derivatives in Electrochemical CO_(2)Reduction

Electrochemically reducing CO_(2)to more reduced chemical species is a promising way that not only enables the conversion of intermittent energy resources to stable fuels,but also helps to build a closed-loop anthropogenic carbon cycle.Among various electrocatalysts for electrochemical CO_(2)reduction,multifunctional metal–organic frameworks(MOFs)have been employed as highly efficient and selective heterogeneous electrocatalysts due to their ultrahigh porosity and topologically diverse structures.Up to now,great progress has been achieved in the design and synthesis of highly active and selective MOF-related catalysts for electrochemical CO_(2)reduction reaction(CO_(2)RR),and their corresponding reaction mechanisms have been thoroughly studied.In this review,we summarize the recent progress of applying MOFs and their derivatives in CO_(2)RR,with a focus on the design strategies for electrocatalysts and electrolyzers.We first discussed the reaction mechanisms for different CO_(2)RR products and introduced the commonly applied electrolyzer configurations in the current CO_(2)RR system.Then,an overview of several categories of products(CO,HCOOH,CH_(4),CH_(3)OH,and multi-carbon chemicals)generated from MOFs or their derivatives via CO_(2)RR was discussed.Finally,we offer some insights and perspectives for the future development of MOFs and their derivatives in electrochemical CO_(2)reduction.We aim to provide new insights into this field and further guide future research for large-scale applications.

急性心肌梗死患者心脏运动康复依从动机的质性研究

目的探究急性心肌梗死(acute myocardial infarction,AMI)行经皮冠状动脉介入(percutaneous coronary intervention,PCI)治疗患者心脏运动康复的依从动机,为提升患者运动康复参与及行为改变提供建议和依据。方法采用描述性质性研究,通过目的抽样法选取2021年7月至2022年1月在上海某三级甲等医院复诊的29例AMI患者进行半结构式深度访谈,其中18例来源于心脏康复中心、11例来源于随访门诊。采用内容分析法整理访谈资料。结果共提炼3个主题和9个亚主题:患者的运动体验(康复获益感、风险感知),患者的心理状态(悲观、恐惧、积极心态)和社会支持(家庭依恋及支持、专业指导及支持、同伴交流及支持、物理资源及支持)。结论护理人员应重视AMI行PCI治疗患者的运动体验、心理状态及社会支持情况,以提高患者心脏运动康复依从动机。

TATA-box-binding protein-associated factor 15 is a novel biomarker that promotes cell proliferation and migration in gastrointestinal stromal tumor

BACKGROUND Gastrointestinal stromal tumor(GIST)is a common neoplasm with high rates of recurrence and metastasis,and its therapeutic efficacy is still not ideal.There is an unmet need to find new molecular therapeutic targets for GIST.TATA-boxbinding protein-associated factor 15(TAF15)contributes to the progress of various tumors,while the role and molecular mechanism of TAF15 in GIST progression are still unknown.AIM To explore new molecular therapeutic targets for GIST and understand the biological role and underlying mechanisms of TAF15 in GIST progression.METHODS Proteomic analysis was performed to explore the differentially expressed proteins in GIST.Western blotting and immunohistochemical analysis were used to verify the expression level of TAF15 in GIST tissues and cell lines.Cell counting kit-8,colony formation,wound-healing and transwell assay were executed to detect the ability of TAF15 on cell proliferation,migration and invasion.A xenograft mouse model was applied to explore the role of TAF15 in the progression of GIST.Western blotting was used to detect the phosphorylation level and total level of RAF1,MEK and ERK1/2.RESULTS A total of 1669 proteins were identified as differentially expressed proteins with 762 upregulated and 907 downregulated in GIST.TAF15 was selected for the further study because of its important role in cell proliferation and migration.TAF15 was significantly over expressed in GIST tissues and cell lines.Overexpression of TAF15 was associated with larger tumor size and higher risk stage of GIST.TAF15 knockdown significantly inhibited the cell proliferation and migration of GIST in vitro and suppressed tumor growth in vivo.Moreover,the inhibition of TAF15 expression significantly decreased the phosphorylation level of RAF1,MEK and ERK1/2 in GIST cells and xenograft tissues,while the total RAF1,MEK and ERK1/2 had no significant change.CONCLUSION TAF15 is over expressed in GIST tissues and cell lines.Overexpression of TAF15 was associated with a poor prognosis of GIST patients.TAF15 promotes cell proliferation and migration in GIST via the activation of the RAF1/MEK/ERK signaling pathway.Thus,TAF15 is expected to be a novel latent molecular biomarker or therapeutic target of GIST.

PBL教学法联合思维导图在外科护士疼痛培训中的应用

目的探讨采用以问题为基础教学法(problembased learning,PBL)联合思维导图教学模式对外科护士疼痛培训的效果研究。方法2021年6月—2022年3月,对上海中医药大学附属市中医医院外科87名临床护士采用PBL教学法联合思维导图教学模式进行疼痛管理知识培训,并采用《护理人员的疼痛知识和态度评估问卷》(the nurses’knowledge and attitude survey,NKAS)于培训前后对参训护士进行疼痛知识和态度评估,以及培训后进行疼痛知识理论考核和教学满意度调查。结果87名外科护士NKAS培训前得分为(15.07±3.45)分,正确率为47.09%,培训后得分为(21.95±5.96)分,正确率为68.61%,差异有统计学意义(P<0.001)。NKAS疼痛一般知识维度分数培训后(5.90±1.81)分高于培训前(4.72±1.72)分,疼痛评估知识维度分数培训后(1.82±0.39)分高于培训前(1.68±0.52)分,药物镇痛知识维度分数培训后(11.95±3.33)分高于培训前(7.72±2.14)分,情景案例分析测试维度分数培训后[2.00(1.00,4.00)分]高于培训前[0(0,1.00)分],差异具有统计学意义(P<0.05)。结论PBL教学法联合思维导图教学模式能有效提高外科护士的疼痛知识水平及疼痛综合应用能力,且充分发挥二者的教学优势,值得在临床继续教育中运用。

Temporal electric field of a helium plasma jet by electric field induced second harmonic(E-FISH)method

Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is diagnosed by the electric field induced second harmonic(E-FISH)method,and the time-resolved electric field under different conditions is investigated.When positive pulse voltage is applied,the electric field has a peak of about 25 kV cm-1at the rising edge of the voltage pulse.A dark channel is left behind the plasma bullet and the electric field in the dark channel is about 5 kV cm-1.On the other hand,when negative pulse voltage is applied,the electric field has a peak of-16 kV cm-1when the negative voltage is increased to-8 kV.A relatively bright channel is left behind the plasma head and the electric field in this relatively bright channel is about-6 kV cm-1.When the pulse rising time increases from 60 to 200 ns,the peak electric field at both the rising edge and the falling edge of the voltage decreases significantly.When 0.5%of oxygen is added to the main working gas helium,the peak electric field at the rising edge is only about 15 kV cm-1.On the other hand,when 0.5%nitrogen is added,the peak electric field increases especially at the falling edge of the voltage pulse,where it increases reversely from-12 to-16 kV cm-1(the minus sign only represents the direction of electric field).

lncRNA ENST00000452996.1通过ERK/GSK-3β/β-catenin信号通路调控肝癌细胞增殖、迁移及侵袭

目的研究一种新的长链非编码RNA ENST00000452996.1对肝癌细胞增殖、迁移及侵袭等的影响及其调控机制。方法TCGA数据集分析肝癌组织ENST00000452996.1表达;构建ENST00000452996.1的shRNA载体,包装病毒感染Huh-7细胞(shENST00000452996.1组),CCK-8法、克隆形成法、流式细胞术、划痕法和Transwell小室法分别检测细胞增殖、凋亡、迁移和侵袭能力;Western blot法检测shENST00000452996.1组、ERK激动剂EGF处理组和GSK-3β抑制剂TDZD-8处理组的ERK/GSK-3β/β-catenin信号分子的表达。结果TCGA分析发现,肝癌组织ENST00000452996.1表达水平明显高于癌旁组织,且与Edmondson-Steiner分级呈正相关,与总生存时间呈负相关;与对照组相比,shENST00000452996.1组细胞增殖、迁移及侵袭能力明显下降,凋亡能力明显增强,p-ERK1/2、p-GSK-3β^(Ser9)和β-catenin表达均下调,GSK-3β和p-β-catenin表达上调,核β-catenin表达下降;与shENST00000452996.1组相比,EGF处理组p-ERK1/2表达升高,EGF处理组和TDZD-8处理组p-GSK-3β^(Ser9)和β-catenin及核β-catenin表达均升高,GSK-3β和p-β-catenin表达均降低。结论干扰ENST00000452996.1表达抑制ERK1/2磷酸化,阻止GSK3β^(Ser9)磷酸化,导致β-catenin磷酸化,抑制β-catenin核转位,推断ENST00000452996.1通过ERK/GSK-3β/β-catenin信号通路增强肝癌细胞增殖、迁移及侵袭能力,抑制细胞凋亡,从而发挥促进肝细胞癌的作用。

基于改进方法的承德地表水环境质量评价

为客观反映地表水水质状况,采用层次分析法和熵权法组合赋权以及加权平均综合评价原则改进模糊综合评价法,并与单因子评价法、内梅罗指数法、传统模糊综合评价法进行比较,评价承德地区地表水环境质量。结果表明:2021年承德地区地表水水质有明显的时空差异性,除7—9月的部分断面水质为较差外,其余断面水质均在Ⅰ~Ⅲ类;影响承德地区地表水水质的主要因子为COD_(Mn)和TP;单因子评价法和内梅罗指数法无法反映整体水质状况,改进的模糊综合评价法相较于传统模糊综合评价法兼顾了各污染因子间相互作用,并弱化了个别水质指标对评价结果的影响,且能够对同一类别水质进行排序,更适用于承德地区地表水环境质量评价。

麻荆宣肺颗粒对人冠状病毒229E感染小鼠肺炎模型的治疗作用

目的 研究麻荆宣肺颗粒对人冠状病毒299E感染小鼠肺炎模型的治疗作用,为其临床应用提供参考。方法 建立人冠状病毒229E感染小鼠模型,感染当天连续给予麻荆宣肺颗粒共4 d。实验第5天动物称重后,眼眶取血,解剖取肺组织并称重,计算肺指数及肺抑制率,实时荧光定量PCR法(Real-time PCR)检测肺组织中病毒载量,流式细胞术检测免疫细胞百分比,酶联免疫法(ELISA)检测肺组织和血清中炎性因子表达量,免疫组化法检测肺组织血管紧张素转化酶2(ACE2)及线粒体组装受体1(MAS1)表达量,组织病理学检测肺组织病变。结果 麻荆宣肺颗粒能显著降低人冠状病毒229E感染小鼠的肺指数(P<0.01),高、中、低剂量的抑制率分别为66.80%、53.20%、45.20%;并显著降低模型动物肺组织中病毒载量(P<0.01);显著升高模型动物外周血淋巴细胞百分比(P<0.05,P<0.01);显著降低模型动物肺组织和血清中炎症因子的含量(P<0.01);显著提高模型动物肺组织ACE2及MAS1的表达(P<0.05,P<0.01);且对支气管及肺泡组织的炎性病变有一定的改善作用。结论 麻荆宣肺颗粒可通过抑制冠状病毒复制、抑制炎症因子释放、调节免疫平衡等途径对人冠状病毒229E肺炎小鼠发挥治疗作用。

甲型流感病毒H1N1型灭活病毒标准物质研究

以人工培养真实病毒为原料,研制了一种甲型流感病毒H1N1型灭活病毒标准物质。该标准物质经化学灭活及灭活效果验证后,联合多家实验室采用数字PCR定量检测方法对拷贝数浓度进行定值,对标准物质的均匀性、稳定性及不确定度进行了评估。结果显示该标准物质均匀性良好,在-80~-70℃保存条件下稳定保存5个月,标准物质最终定值结果为(1384.5±249.3)copies/μL(k=2)。该标准物质可为H1N1型甲型流感病毒检测的全过程提供计量溯源和质量控制支撑,有助于提升相关核酸检测结果的准确性和可靠性。

术前新型冠状病毒感染患者慢性术后疼痛发生率及其危险因素分析:一项双向队列研究

目的探究术前新型冠状病毒感染(corona virus disease 2019,COVID⁃19)患者慢性术后疼痛(chronic postsurgical pain,CPSP)发生现况,并进一步分析CPSP的危险因素。方法本研究为一项双向队列研究,研究对象来源于一项已完成随访的前瞻性队列研究。回顾性纳入2022年12月1日—2023年2月28日北京协和医院术前合并COVID⁃19且接受手术治疗患者的临床资料,并前瞻性对入组患者随访至术后6个月,主要结局指标为CPSP。采用多因素Logistic回归模型分析COVID⁃19相关暴露指标与CPSP的相关性。结果共入选符合纳入与排除标准的手术患者4117例,术前均合并COVID⁃19。其中急性期轻症4002例,重症62例,危重症53例。术后6个月时伴有长新冠综合征1298例(31.53%),CPSP发生率为5.59%(95%CI:4.88%~6.28%)。多因素Logistic回归分析校正年龄、性别、合并症、麻醉方法、手术种类等混杂因素后发现,急性期危重症COVID⁃19(aOR=3.35,95%CI:1.48~7.62,P<0.001)、有术后长新冠综合征(aOR=2.50,95%CI:1.90~3.29,P<0.001)与CPSP相关。结论本研究首次明确急性期危重症及术后存在长新冠综合征与术前COVID⁃19患者CPSP具有相关性。

采用改进多目标粒子群算法的斜拉桥阻尼器参数优化

为克服大跨度斜拉桥黏滞阻尼器优化设计效率低、多个相互制约的减震控制目标的问题难以权衡,基于遗传算法的“变异”方法,提出了改进多目标粒子群算法来进行阻尼器参数优化设计。建立大跨度斜拉桥的有限元模型,开展了全桥地震响应分析,根据抗震需求在桥梁纵向设置黏滞阻尼器;分别建立了塔底弯矩、阻尼力和梁端位移的减震响应与阻尼器参数之间的响应面数学模型;以减震响应面模型为研究对象,通过该算法进行阻尼器参数全局自动寻优分析,确定了阻尼器的最优参数,并与采用参数敏感性分析方法确定的一组阻尼参数进行对比分析。研究结果表明:该优化方法具有计算精度好、优化效率高和更好地权衡多个相互制约的减震控制目标的优点;通过优化算法获得的阻尼器参数组合相比采用参数敏感性分析方法获得的阻尼参数组合的减震响应,塔底弯矩增大1.73%,阻尼力减小5.97%,梁端位移减小1.66%;在无需多次有限元试算的基础上确定了更高精度的阻尼器优化参数组合,在提高减震效果的同时大大提升了计算效率。

成年人中心性气道流体力学特征分析

目的运用计算流体力学(CFD)技术对健康成年人中心性气道进行流体力学特征分析,研究空气流场对中心性气道的影响。方法选择4例健康成年人胸部CT影像,其中男性2例,女性2例;年龄26~53岁,平均年龄37.5岁;体质量48.5~74.0 kg,平均体质量60.6 kg。使用Mimics 21医学图像软件将4例健康成年人的胸部CT图像以医学数字成像与通信(DICOM)格式导入,并构建中心性气道的三维模型。对三维模型进行修整,使用Geomagic Studio 12软件。使用Ansys fluent 19.2软件的网格划分模块将模型进行网格划分。划分好网格后,将其导入Ansys 19.2软件进行CFD模拟计算。在模拟计算中,设定相同的潮气量,并对中心性气道内部气流流场变化进行动态分析。结果在基于CT图像数据构建的中心性气道的三维模型基础上,使用了CFD进行数值模拟。结果显示,在施加相同潮气量的情况下,气流入口速度为2.15~4.44 m/s。气道流速在从入口到出口的过程中逐渐降低,并形成了高流速的区域。气道最大流速的变化为3.25~6.77 m/s,并且最大流速靠近气管壁面。气道壁面压力由气管到支气管逐渐降低。在流速越高的区域,气道壁面压力的绝对值越高。气道壁面最大切应力变化为0.888~2.240 Pa,其中气管壁、气管分叉处及二级、三级支气管的切应力相对较大,并随着气管和支气管的直径减小而增加。结论通过对健康成年人中心性气道模型进行CFD模拟,发现气道流速、壁面压力、壁面切应力与气道结构有着密切的关系,呈现出一定的整体空间分布和局部特征。

上钠腔设计对大型MOX燃料快堆冷却剂沸腾瞬态的影响研究

钠空泡反应性效应是钠冷快堆核设计和安全分析的重要内容。本文基于多群节块扩散法,采用微扰理论对1000 MWe钠冷快堆具有上钠腔结构的MOX燃料堆芯的总钠空泡反应性、空间分布、物理分项进行计算。基于钠空泡反应性的计算结果,利用中国原子能科学研究院自主开发的钠冷快堆堆芯瞬态分析程序对1000 MWe钠冷快堆进行了无保护失流事故的瞬态分析,分别对具有上钠腔设计的堆芯和无上钠腔结构的堆芯安全性进行了评价。分析结果表明,上钠腔设计大大缓解了钠冷快堆冷却剂沸腾瞬态的事故后果,为钠冷快堆堆芯的安全设计提供了重要参考。

远隔缺血后适应治疗对急性缺血性卒中超时间窗患者临床预后的影响:一项随机对照试验

背景急性缺血性卒中(AIS)高发,及时恢复脑血流是治疗的关键,超时间窗就诊患者无更多促进脑血流恢复的治疗手段。研究远隔缺血后适应(RIPostC)治疗对AIS超时间窗就诊患者的临床疗效、并发症和预后,具有重要的临床意义。目的探究RIPostC治疗对AIS超时间窗患者干预的影响,为超时间窗就诊的AIS患者寻求安全、有效的脑血流恢复治疗方式。方法本研究采用随机、分组、安慰剂对照法进行试验。选取2021-09-02—2022-08-31于北京航天总医院神经内科病房住院治疗的超溶栓时间窗(发病时间>6 h)的AIS患者为研究对象。依据随机数字表法将患者分为对照组和试验组。试验期+随访期共90 d,均使用同等的一般治疗、脑血管病常规治疗,试验组在此基础上给予RIPostC治疗14 d(28次),对照组给予模拟的RIPostC治疗14 d(28次)。在干预前和干预后30 d、干预后90 d,采用改良Rankin量表(mRS)、美国国立卫生研究院卒中量表(NIHSS)评估两组患者神经功能,简易精神状态检查量表(MMSE)、蒙特利尔认知评估量表(MoCA)评估患者认知功能,工具性日常生活能力量表(IADL)评估日常生活能力,焦虑自评量表(SAS)、抑郁自评量表(SDS)评估精神状态,经颅多普勒超声(TCD)评估脑血流速度,以白介素(IL)-6反映炎症情况。结果122例患者中,最终完成试验及随访99例,其中试验组49例,对照组50例。两组患者性别、年龄、基础疾病(高血压、糖尿病、冠心病)及基线NIHSS评分比较,差异无统计学意义(P>0.05)。重复测量方差分析结果示,时间与组别对MMSE、MoCA、mRS、NIHSS、脑血流速度、IL-6存在交互作用(P<0.05),时间和组别对MMSE、MoCA、NIHSS、脑血流速度、IL-6主效应显著(P<0.05),时间对mRS、SAS、SDS、IADL主效应显著(P<0.05)。试验组干预后30、90 d MMSE、MoCA评分及脑血流速度均高于对照组,mRS、NIHSS评分均低于对照组(P<0.05);试验组干预后30、90 d SDS、IADL评分低于对照组(P<0.05);试验组干预后30 d SAS评分高于对照组,IL-6低于对照组(P<0.05)。99例患者中共有23例患者发生不良反应,其中试验组17例,对照组6例,两组皮肤瘀点、头晕、心慌、胸闷发生率比较,差异无统计学意义(P>0.05);对照组患者皮肤瘀斑发生率[4.00%(2/50)与12.24%(6/49)]、总不良反应发生率[12.00%(6/50)与34.69%(17/49)]低于试验组(P<0.05)。结论RIPostC治疗可降低AIS患者的炎症反应,对神经功能、认知功能抑郁情绪及颅内血流速度可起到积极的改善效果。