近远场地震下RC大跨轻柔拱桥减隔震支座方案优化

为探明不同地震动输入对某大跨轻柔拱桥减隔震的影响,通过非线性有限元模型分析近远场地震下桥梁结构的响应规律,得到大桥支座的优化布置方案.首先,基于模态分析,对比该桥与传统钢筋混凝土(RC)拱桥动力特性差异;其次,选取不同脉冲周期的近场地震动、近场无脉冲及远场长周期地震动记录;最后,研究近远场地震下拱桥的响应行为和损伤演化路径,得到优化桥梁的减隔震支座设计方案.研究结果表明:近场脉冲及远场长周期地震下的桥梁结构响应大于无脉冲地震响应;纵竖向地震下高墩柱剪力及弯矩包络曲线呈“S”形,墩身中部易形成塑性铰,高阶振型影响显著;桥梁纵桥向先于横向震损,损伤路径依次为矮柱、高墩柱及拱肋实心-空心截面段;摩擦摆支座减震效果最佳但位移较大,高阻尼支座方案在近场中长脉冲周期及远场长周期地震下仍会发生损伤,板式橡胶支座方案因无法保证支座同步滑移而不能形成准隔震体系;“高阻尼+摩擦摆”混合方案的支座位移小,拱肋及墩柱均处于弹性,是近断层大跨轻柔RC拱桥的优选减隔震方案.

The Value of γδ T Cells in Lung Infections and Advances in Diagnosis and Treatment

Lung infections are usually caused by pathogenic microorganisms and are a disease with high morbidity and mortality. In clinical practice, the use of broad-spectrum antibiotics has become increasingly common, but this has also led to the problem of antibiotic abuse and irrational use, which in turn has spawned the emergence of multidrug-resistant bacteria, making the treatment of lung infections more complex and difficult. In the human immune system, γδ T cells play a crucial role in defense against foreign pathogens and regulation of autoimmune responses. These cells act as a bridge between innate and adaptive immunity and can be rapidly activated in the early stages of infection to produce inflammatory factors and chemokines that attract other immune cells to the site of infection. Recent advances have shown that γδ T cells not only play a direct role in the innate immunity of pathogen infection, but are also involved in regulating the subsequent adaptive immune response. The aim of this review is to explore the mechanism of γδ T cells in lung infections and to summarize the current progress of clinical research, with the aim of providing new scientific basis and therapeutic strategies for the treatment of lung infections.

Bioinformatics Analysis of the Biological Properties of Ewing Sarcoma

Purpose: Bioinformatics-based approach to screen and analyze differentially expressed genes associated with the biological characteristics of Ewing sarcoma. Means: The GSE17674 dataset was selected for analysis, obtained by data retrieval based on the GEO public database. The R language limma toolkit was used to screen DEmRNAs. After the data were normalized, the Metascape online analysis software and the R language clusterProfiler package were used to analyze the GO function and KEGG pathway enrichment of DEmRNAs lines, respectively. The string database was selected for PPI analysis, and the results were imported into Cytoscape software to derive the core modules and predicted core genes. The genes selected above were analyzed for tissue localization specificity. Results: Through the analysis of GSE17674, differentially expressed genes were screened out, and GO and KEGG analyses were performed on the differentially expressed genes. The GO functional enrichment analysis was mainly enriched in the process of muscle system, muscle contraction, myocyte development, contractile fibers, myogenic fibers, myofibers, myofibrillar segments, actin binding, structural composition of muscle, and actin filament binding. KEGG pathway analysis showed that the core pathways associated with the development of ES were the core genes for myocardial contraction, congestive cardiomyopathy, and hypertrophic cardiomyopathy. Five Hub genes were obtained based on Cytoscape prediction. Tissue localization specificity analysis of Hub genes was performed, and a total of 2 Hub genes with tissue specificity were screened;MYH6 was specifically expressed in cardiac cells and MYL1 was specifically expressed in skeletal muscle cells. Conclusions: The differential genes screened will help to understand the molecular mechanisms underlying the highly invasive and metastasis-prone biological characteristics of ES, as well as provide new ideas for clinical drug-targeted treatment of ES.

Research Progress of Radical Treatment of Helicobacter Pylori Based on Drug Sensitivity Test as First-Line Treatment

Helicobacter pylori (HP) infection is a global problem that affects about half of the world’s population and requires sufficient attention in clinical and scientific work. Due to differences in economic and medical conditions among countries around the world, there is currently no unified treatment plan for anti-HP. In China, empirical quadruple therapy is mainly used. With the abuse of antibiotics, many patients face the problem of secondary eradication after failure, and the resistance rate of HP is gradually increasing. After eradication failure, drug sensitivity cultivation is carried out to choose sensitive antibiotics for treatment. A new strategy is currently needed to address how to improve the eradication rate of HP during the first eradication. This article aims to discuss the first-line treatment plans and research progress for eradicating HP based on drug sensitivity testing before eradication. Compared with traditional empirical therapies, treatment based on drug sensitivity results can effectively improve the eradication rate of HP, and reduce drug resistance rates, and adverse reactions, among other benefits. .

基于创新人才培养的国家级实验教学示范中心持续建设

化学国家级实验教学示范中心(兰州大学)作为兰州大学“双一流”建设化学学科的重要支撑平台,牢记为党育人初心使命,落实立德树人根本任务,以创新人才培养为目标,搭建出优质的实验教学资源共享平台,形成了“基础→综合→科研训练”三层次的实验教学体系。实验教学改革中强化科教融合、以赛促建,培养学生的创新能力,以高水平实验教学支撑了高质量创新型化学拔尖人才的培养,学生的实践和创新能力增强,综合素质优秀。在课程及教材建设、实验教学改革与研究、实验室建设等方面取得了良好进展,示范辐射作用显著。

“元素无机化学”研究生课程建设及混合式教学实践

为培养高素质研究型创新型人才,对研究生课程“元素无机化学”的课程资源建设和教学模式改革进行了探索与实践。主要举措包括重构分层知识体系、建设多维课程资源、推进线上线下混合式教学、实施全程多维评价、深度融入课程思政。多措并举,提高了学生自主学习、拓展学习、交互学习的能力,实现了“知识传授、能力培养和价值引领浑然一体”的人才培养目标,提升了学生的综合素养和科技创新能力。

基于深度学习的学生学习行为规制路径研究

由于自身和外部环境因素的影响,在线上线下混合式教学中,学生会出现一些问题学习行为,而问题学习行为必将弱化学习效果,无法实现深度学习。通过线上线下混合式教学中的学生学习行为,总结教学过程中普遍存在的三个问题:学习目标价值偏离,线上即时引导面临挑战;线下教学模式依赖固化,线上即时指导存在障碍;评价未适用混合式教学,评价结果效用缺位。在此基础上,以规制学生学习行为为目标,提出价值引导、任务驱动及立体评价三个机制。在三个规制机制的指导下,把课程的教学设计作为一种学术研究,在《隧道工程》教学中针对性地创设不同的规制措施,并观测学生的反馈效果。再通过发放问卷调查课程教学的效用,结果表明,该教学设计可以有效增强学生知识习得和优化学习行为,有效促进深度学习的实现。

Lightweight and highly robust memristor-based hybrid neural networks for electroencephalogram signal processing

Memristor-based neuromorphic computing shows great potential for high-speed and high-throughput signal processing applications,such as electroencephalogram(EEG)signal processing.Nonetheless,the size of one-transistor one-resistor(1T1R)memristor arrays is limited by the non-ideality of the devices,which prevents the hardware implementation of large and complex networks.In this work,we propose the depthwise separable convolution and bidirectional gate recurrent unit(DSC-BiGRU)network,a lightweight and highly robust hybrid neural network based on 1T1R arrays that enables efficient processing of EEG signals in the temporal,frequency and spatial domains by hybridizing DSC and BiGRU blocks.The network size is reduced and the network robustness is improved while ensuring the network classification accuracy.In the simulation,the measured non-idealities of the 1T1R array are brought into the network through statistical analysis.Compared with traditional convolutional networks,the network parameters are reduced by 95%and the network classification accuracy is improved by 21%at a 95%array yield rate and 5%tolerable error.This work demonstrates that lightweight and highly robust networks based on memristor arrays hold great promise for applications that rely on low consumption and high efficiency.

一款紧致化妆品的功效评价方法研究

通过对以棕榈酰五肽-4为主要功能成分化妆品的功效进行评价,研究建立人体紧致功效评价方法体系。筛选31名20~50岁女性受试者,分别在使用产品0周、4周和8周,通过客观测试数据、图像方法及受试者自我评估方法对皮肤各项指标进行评估,采集受试者脸颊、眼角部位的皮肤弹性、皮肤真皮密度等参数,以及TPEF图像及SHG图像,并进行比较分析。结果显示,8周后皮肤弹性、真皮密度(P<0.001)及真-表皮链接指数(DEJI)(P<0.01)有显著变化,与受试者自我评分结果一致,表明方法之间具有相关性。该研究方法可为建立化妆品紧致功效评价方法体系提供技术支持。

Epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China:a hospital-based retrospective study

Traumatic spinal cord injury is potentially catastrophic and can lead to permanent disability or even death.China has the largest population of patients with traumatic spinal cord injury.Previous studies of traumatic spinal cord injury in China have mostly been regional in scope;national-level studies have been rare.To the best of our knowledge,no national-level study of treatment status and economic burden has been performed.This retrospective study aimed to examine the epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China at the national level.We included 13,465 traumatic spinal cord injury patients who were injured between January 2013 and December 2018 and treated in 30 hospitals in 11 provinces/municipalities representing all geographical divisions of China.Patient epidemiological and clinical features,treatment status,and total and daily costs were recorded.Trends in the percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department and cost of care were assessed by annual percentage change using the Joinpoint Regression Program.The percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department did not significantly change overall(annual percentage change,-0.5%and 2.1%,respectively).A total of 10,053(74.7%)patients underwent surgery.Only 2.8%of patients who underwent surgery did so within 24 hours of injury.A total of 2005(14.9%)patients were treated with high-dose(≥500 mg)methylprednisolone sodium succinate/methylprednisolone(MPSS/MP);615(4.6%)received it within 8 hours.The total cost for acute traumatic spinal cord injury decreased over the study period(-4.7%),while daily cost did not significantly change(1.0%increase).Our findings indicate that public health initiatives should aim at improving hospitals’ability to complete early surgery within 24 hours,which is associated with improved sensorimotor recovery,increasing the awareness rate of clinical guidelines related to high-dose MPSS/MP to reduce the use of the treatment with insufficient evidence.

嗜酸氧化亚铁硫杆菌作用下含黄铁矿废石的生物溶解和动力学

使用生物淋洗处理黄铁矿废石,从源头上缓解其产生酸性矿山废水(AMD)的风险。生物淋洗结果显示,在嗜酸氧化亚铁硫杆菌(A.ferrooxidans)的作用下,40天内可以从黄铁矿废石中去除近82%的铁和硫。动力学研究结果表明,废石中黄铁矿的去除主要受化学反应和内扩散控制。X射线衍射(XRD)和X射线光电子能谱(XPS)的结果表明,在A.ferrooxidans细菌介导下,生物源黄钾铁矾能够钝化废石中残余的黄铁矿。对渣样进行二次生物浸出,试验发现溶液pH没有明显下降,且仅有8 mg/L和160mg/L的铁从两个黄铁矿废石渣样中溶出,表明渣样的酸和铁释放能力得到削弱。

人鼻粘膜类器官冠状病毒感染模型可用于抗病毒药物的筛选和评价

目的利用人鼻粘膜类器官建立冠状病毒(CoV)感染模型,并用于药物抗病毒作用体外评价,探讨人类鼻粘膜类器官病毒感染模型用于病毒研究和抗病毒药物开发的可行性。方法使用人源鼻粘膜类器官,测试其对SARS-CoV-2和HCoV-OC43假病毒的易感性。在P3实验室中,评估鼻粘膜类器官对SARS-CoV-2原始株及4种变异株的感染情况,优化感染条件。通过荧光定量PCR检测不同时间点培养基中病毒含量,并利用免疫荧光法定位新冠病毒衣壳蛋白,以确定病毒感染细胞的类型。在优化后的鼻粘膜病毒感染模型中,分析已知具有抑制新冠病毒作用的化合物,如卡莫司他和佛手柑素,单因素方差分析推断其在类器官中的抑制效果并预测其机制。结果通过培养体系和感染条件的优化,使用SARS-CoV-2不同亚型感染鼻粘膜类器官,结果显示,2~24 h受感染鼻粘膜类器官上清液中的病毒载量明显增加,鼻粘膜类器官可被SARS-CoV-2,HCoV-OC43假病毒感染(P<0.001)。真病毒感染实验证实,SARS-CoV-2原始株及4种变异株,均能稳定感染鼻粘膜类器官,证实病毒感染模型的建立。卡莫司他和佛手柑素,在鼻粘膜类器官中均剂量依赖性抗病毒作用(P<0.0001)。结论人鼻粘膜类器官能够作为新冠病毒感染模型,用于抗病毒药物筛选和评价,特别是经鼻腔给药方式的提供了理想的体外研究模型。

Association between physical activity and risk of gastroesophageal reflux disease:A systematic review and meta-analysis

Background:Lifestyle plays an important role in preventing and managing gastroesophageal reflux disease(GERD).In response to the conflicting results in previous studies,we performed a systematic review and meta-analysis to investigate this association.Methods:Relevant studies published until January 2023 were retrieved from 6 databases,and the prevalence of symptomatic gastroesophageal reflux(GER)or GERD was determined from the original studies.A random effects model was employed to meta-analyze the association by computing the pooled relative risk(RR)with 95%confidence intervals(95%CIs).Furthermore,subgroup and dose-response analyses were performed to explore subgroup differences and the association between cumulative physical activity(PA)time and GERD.Results:This meta-analysis included 33 studies comprising 242,850 participants.A significant negative association was observed between PA and the prevalence of symptomatic GER(RR=0.74,95%CI:0.66-0.83;p<0.01)or GERD(RR=0.80,95%CI:0.76-0.84;p<0.01),suggesting that engaging in PA might confer a protective benefit against GERD.Subgroup analyses consistently indicated the presence of this association across nearly all subgroups,particularly among the older individuals(RR_(<40 years):RR_(≥40 years)=0.85:0.69,p<0.01)and smokers(RR_(smoker):RR_(non-smoker)=0.67:0.82,p=0.03).Furthermore,a dose-response analysis revealed that individuals who engaged in 150 min of PA per week had a 72.09%lower risk of developing GERD.Conclusion:Maintaining high levels of PA decreased the risk of GERD,particularly among older adults and smokers.Meeting the recommended PA level of 150 min per week may significantly decrease the prevalence of GERD.

Using choroidal thickness to detect myopic macular degeneration

AIM:To explore the usage of choroidal thickness measured by swept-source optical coherence tomography(SS-OCT)to detect myopic macular degeneration(MMD)in high myopic participants.METHODS:Participants with bilateral high myopia(≤−6 diopters)were recruited from a subset of the Guangzhou Zhongshan Ophthalmic Center-Brien Holden Vision Institute High Myopia Cohort Study.SS-OCT was performed to determine the choroidal thickness,and myopic maculopathy was graded by the International Meta-Analysis for Pathologic Myopia(META-PM)Classification.Presence of MMD was defined as META-PM category 2 or above.RESULTS:A total of 568 right eyes were included for analysis.Eyes with MMD(n=106,18.7%)were found to have older age,longer axial lengths(AL),higher myopic spherical equivalents(SE),and reduced choroidal thickness in each Early Treatment Diabetic Retinopathy Study(ETDRS)grid sector(P<0.001).The area under the receiver operating characteristic(ROC)curves(AUC)for subfoveal choroidal thickness(0.907)was greater than that of the model,including age,AL,and SE at 0.6249,0.8208,and 0.8205,respectively.The choroidal thickness of the inner and outer nasal sectors was the most accurate indicator of MMD(AUC of 0.928 and 0.923,respectively).An outer nasal sector choroidal thickness of less than 74μm demonstrated the highest odds of predicting MMD(OR=33.8).CONCLUSION:Choroidal thickness detects the presence of MMD with high agreement,particularly of the inner and outer nasal sectors of the posterior pole,which appears to be a biometric parameter more precise than age,AL,or SE.

可自动校准距离的智能手机视力测试APP(WHOeyes)的真实世界应用

目的:开发一款可自动校准测试距离的智能手机视力检测APP(WHOeye的iOS版本),并评估其实用性。方法:WHOeyes在经过验证的视力检测APP“V@home”的基础上新增自动距离校准(automatic distance calibration,ADC)功能。研究招募了3组不同年龄(≤20岁、20~40岁、>40岁)的中国受试者,分别使用糖尿病视网膜病变早期治疗研究(Early Treatment Diabetic Retinopathy Study,ETDRS)视力表和WHOeyes进行远距离和近距离的视力检测。ADC功能用于确定WHOeyes的测试距离。红外测距仪用于确定ETDRS的测试距离以及WHOeyes的实际测试距离。通过问卷调查评估用户满意度。结果:WHOeyes ADC确定的实际测试距离在3个年龄组中均与预期测试距离总体上表现出良好的一致性(P>0.50)。在远距离和近距离视力检测方面,WHOeyes的准确性与ETDRS相当。WHOeyes与ETDRS之间的平均视力差异范围为–0.084~0.012 logMAR,各组的二次加权卡帕系数(quadratic weighted kappa,QWK)均大于0.75。WHOeyes在近距离和远距离视力检测中的重测信度高,平均差异范围为–0.040~0.004 logMAR,QWK均大于0.85。问卷调查显示WHOeyes具有较好的用户体验和接受度。结论:与金标准ETDRS视力表方法相比,WHOeyes测试距离较为准确,可以提供准确的远距离和近距离视力测量结果。

Preferentially selective extraction of lithium from spent LiCoO_(2)cathodes by medium-temperature carbon reduction roasting

Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.

Optimizing support performances of bolt reaming and anchoring in a coal drift

In current practice of bolt reaming and anchoring of roadways in soft coal and rock mass,resin cartridges bend easily under the strong pushing and stirring of bolts,and the resin accumulates in the bolt-reamed area and does not participate in the stirring.As a result,bolts encounter high drilling resistance and cannot reach the bottom of drillholes.The effective anchorage length is far less than the actual anchorage length.Bolts are not centered,and the shear is misaligned at the joint surface in the reaming area,which leads to cracking of the whole anchoring solid and large shear deformation of bolts.This study systematically analyzes the characteristics of roadway bolt reaming and anchoring.The influences of resin stirring force,bolt pull-out force,and reamingeanchoring solid strength on reamingeanchoring performance were analyzed theoretically.The main purpose is to develop a device that enhances reaming and anchoring.The mechanism through which the device strengthens the reamingeanchoring solid was analyzed theoretically.Numerical simulation and experiments were carried out to verify the improved performance of the small-pore reaming and anchoring using the proposed technology.The results showed that the stirring migration rate of the resin cartridge is greatly improved by adding the device to bolts.The reaction rate of the anchoring mixture,stirring pressure,pull-out force of the reaming and anchoring system,bolt concentricity,and shear and compressive strengths of the anchoring solid are also enhanced in the reaming area.This ensures that the resin cartridge in the reaming area is completely stirred,which greatly improves the shear resistance of the reamingeanchoring solid.Meanwhile,the drilling performance,torsional force,and stirring efficiency of bolts are maximized and prevail over those of conventional bolts.

Observer-based robust high-order fully actuated attitude autopilot design for spinning glide-guided projectiles

This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external disturbances.Based on fixed-time stable theory,a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects,irrespective of initial conditions.By introducing an error integral signal,the dynamics of the SGGP are transformed into two separate second-order fully actuated systems.Subsequently,employing the high-order fully actuated approach and a parametric approach,the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system,ensuring that the projectile's attitude asymptotically tracks the given goal with the desired eigenstructure.Under the proposed composite control framework,the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov method.Validation of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations.

11.2 W/mm power density AlGaN/GaN high electron-mobility transistors on a GaN substrate

In this letter,high power density AlGaN/GaN high electron-mobility transistors(HEMTs)on a freestanding GaN substrate are reported.An asymmetricΓ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance.The breakdown voltage(BV)is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92μm.A record continuous-wave power density of 11.2 W/mm@10 GHz is realized with a drain bias of 70 V.The maximum oscillation frequency(f_(max))and unity current gain cut-off frequency(f_(t))of the AlGaN/GaN HEMTs exceed 30 and 20 GHz,respectively.The results demonstrate the potential of AlGaN/GaN HEMTs on freestanding GaN substrates for microwave power applications.

高铁桥梁装配式双柱空心墩承插深度研究

高铁桥梁桥墩刚度大,结构及构造有别于公路及市政桥梁,大量既有公路、市政承插式桥墩的研究成果是否适用于承插式铁路墩,需进行深入系统的研究。建立现浇和承插式双柱原型空心墩的非线性有限元模型,并结合既有试验结果验证了建模方法的正确性。通过模拟桥墩在拟静力往复作用下的力学行为,得到双柱空心墩的力-位移曲线,对比承插式桥墩与现浇桥墩滞回性能的差异,结合应变渗透效应及纵筋发展长度确定了承插深度的合理取值范围,并提出最小承插深度计算公式。结果表明:承插式桥墩与现浇墩的承载力差别很小,墩高5 m和10 m时,相差最大为2.8%;承插式桥墩和现浇墩的刚度退化规律基本一致,刚度随着侧向位移的增加而降低,位移较小时刚度退化较快,位移较大时刚度退化减慢;纵筋在塑性铰区及承台顶以下应变渗透区内屈服,在此区域以下400 mm范围应变则迅速减小,应变渗透区段为承插式墩身易损部位;根据本文提出的最小承插深度计算公式得到的高铁空心墩的最小承插深度设计值为0.5D(D为墩柱外径)。为保证承插式桥墩的安全性,应采取合理构造措施确保桥墩应变渗透区段抗震性能,推荐高烈度区桥墩的承插深度大于0.5D。