Müller cells are activated in response to retinal outer nuclear layer degeneration in rats subjected to simulated weightlessness conditions

A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.

Erratum to:Vibration analysis of a gear-rotor-bearing system with outer-ring spalling and misalignment

Because of an unfortunate mistake during the production of this article,Figure 13 was wrongly inserted.The corrected Figure 13 is shown as follows.

Analysis and optimization of stamping and forming process of bearing outer ring

To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators such asforming limits,thickness distribution,and principal strains in the forming process in detail.Three-dimensionalmodels of the concave and convex dies were constructed.The effects of different process parameters,includingstamping speed,edge pressure,sheet metal thickness,and friction coefficient,on the quality of the forming partswere investigated by varying these parameters.Subsequently,the orthogonal experimental method was used todetermine an optimal experimental group from multiple sets of experiments.It was found that under the processparameters of a stamping speed of 3000 mm/s,edge pressure of 2000 N,sheet metal thickness of 0.9 mm,andfriction coefficient of 0.125,the forming quality of the outer ring of the bearing is ideal.

Cooling and Optimization in the Groove of the Outer Rotor HubMotor

The external rotor hub motor adopts direct drive mode,no deceleration drive device,and has a compact structure.Its axial size is smaller than that of a deceleration-driven hub motor,which greatly reduces the weight of the vehicle and increases the cruising range of the vehicle.Because of the limited special working environment and performance requirements,the hub motor has a small internal space and a large heat generation,so it puts forward higher requirements for heat dissipation capacity.For the external rotor hub motor,a new type of in-tank watercooled structure of hub motor was proposed to improve its cooling effect and performance.Firstly,the threedimensional finite element model of the motor is established to analyze the characteristics of motor loss and temperature field distribution.Secondly,the cooling performance of different cooling structures in the tank was studied.Finally,the thermal network model and three-dimensional finite element analysis were used to optimize the water-cooled structure in the tank,and the power density of themotor was improved by improving the cooling performance under the condition of volume limitation of the hub motor.The results show that the cooling effect of the proposed water-cooled structure in the tank is significant under the condition of constant power density.Compared to natural ventilation,the maximum temperature was reduced by 33.13°C and the cooling effect was increased by about 27.7%.

内置CFRP圆管的方钢管再生混凝土偏压短柱力学性能研究

研究外截面形式、受压类型和偏心率等变化参数对内置CFRP圆管的方钢管再生混凝土短柱力学性能的影响。利用ABAQUS有限元分析软件建立组合柱力学模型,在有限元模拟和轴压试验结果吻合的基础上,进一步研究试件的偏压力学性能。增加CFRP层数,对轴压试件的极限承载力和位移延性系数提高幅度可分别达到30.44%、41.11%,对偏压试件的极限承载力和位移延性系数提高幅度分别为5.97%、37.49%;增加偏心率,对方截面试件的极限承载力和位移延性系数降低幅度分别达到41.22%、20.16%,对圆截面试件的极限承载力和位移延性系数降低幅度分别为45.79%、33.02%。内置CFRP圆管能够改善方钢管再生混凝土短柱的力学性能,但对偏压柱的影响小于轴压柱;在模拟参数范围内,随着偏心率的增加,试件力学性能降低;但同等截面面积下,方截面试件的偏压力学性能比圆截面试件的偏压力学性能更稳定。

双向赋能:区域国别学视角下的外层空间国际战略研究

我国外层空间国际战略研究面临客观需求迫切、有效供给匮乏的“研究赤字”。交叉学科门类下区域国别学一级学科的设立为加强外层空间国际战略研究带来了有益思路。区域国别学为外层空间国际战略研究的系统集成提供了新的条件,使后者主体性得以彰显、交叉性得以实现、应用性得以提高、价值使命得以明确。外层空间国际战略研究亦可以促进区域国别学研究对象的扩展、研究方法的交叉、学科价值的实现,从而赋能区域国别学学科发展。外层空间国际战略研究作为一个研究领域,与区域国别学学科存在着显著的“双向赋能”关系。未来,建议在区域国别学框架下建立系统集成的外层空间国际战略研究议程。

RELEASE KINETICS OF MONOLITHIC MATRIX COATED WITH OUTER MEMBRANE SYSTEM

The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.

羊源肺炎克雷伯菌分离鉴定及其外膜囊泡提取方法的建立

旨在探究羊源肺炎克雷伯菌的致病性及其外膜囊泡的提取方法。本研究对伴有咳嗽、腹泻症状死亡的绵羊剖检并采集肺,肝,空肠等病变器官,采用形态观察、生化特性鉴定,分子生物学鉴定及测序方法对病原菌进行分离鉴定;通过药敏试验、拉丝试验、毒力基因检测、致病性试验及病理组织学观察分析其致病性和耐药性;使用改良沉淀法提取其外膜囊泡,通过透射电镜,纳米粒径测定及SDS-PAGE进行鉴定。结果显示病原菌经分离纯化后镜下呈现卵圆形革兰阴性杆菌,结合生化试验及16S rRNA鉴定结果表明该病原菌为肺炎克雷伯菌;药敏试验结果显示病原菌对阿米卡星,头孢他啶,亚胺培南,哌拉西林四种药物敏感;拉丝试验结果符合阳性特征及毒力基因扩增显示荚膜多糖基因wzy-K1及代谢基因peg-344为阳性,确定该病原菌为高毒力肺炎克雷伯菌;小鼠致病性试验结果表明病原菌对小鼠半数致死量(LD_(50))浓度为1.8×10^(5 )CFU,经病理组织学观察肝脏、脾脏淤血且有大量炎性细胞浸润;透射电镜,纳米粒径测定显示沉淀物形态结构、粒径大小均符合细菌外膜囊泡特征,SDS-PAGE显示存在特征性条带。本试验成功从病死绵羊体内分离出高毒力肺炎克雷伯菌并通过沉淀法提取其外膜囊泡,为预防和治疗羊源肺炎克雷伯菌病提供参考及肺炎克雷伯菌外膜囊泡的基础研究提供帮助。

Study on Outer Membrane Protein Patterns of Escherichia coli O38,O53 and O75 Isolated from Chickens

[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes were used as experimental materials to extract OMP by using supersonic schizolysis method and Sarcosyl. After SDS-PAGE electrophoresis, OMP patterns of the extracted products were determined based on the OMP model diagram. [Result] OMP of eight E. coil isolates with three serotypes were divided into three patterns, to be specific, 2 075 isolates respectively belonged to OMP-I and OMP-II pattern, 1 053 isolate belonged to OMP-II pattern, and 5 038 isolates belonged to OMP-I and OMP-III pattern. [Conclusion] Experimental results showed that E. coli isolates with the same serotype may belong to completely different OMP patterns, while serologically unrelated isolates may belong to the same OMP pattern. OMP of E. coil isolates with the same serotype may generate genetic differentiation; in addition, OMP of E. coli isolates with different serotypes may have different genetic correlation.

环形复合内衬头盔冲击波防护性能研究

冲击波防护能力是单兵头盔的主要性能指标,对提高单兵战场生存能力具有重要意义。为了提高单兵头盔的冲击波防护性能,针对先进战斗头盔内衬的结构以及布置方式展开探索,提出环形聚脲-聚氨酯泡沫-海绵复合材料外沿内衬设计,并进行防护性能评估。通过激波管和实爆,针对有/无头盔以及装配不同结构及尺寸外沿内衬头盔的冲击波防护性能展开测试,对前额、颅顶及后脑3个重点区域位置表面的冲击波波形以及压力峰值进行对比分析。实验结果表明:佩戴头盔后冲击波主要通过头-头盔间隙以绕射的形式进入并作用于头部表面,间隙内冲击波聚集叠加反而可能会使压力增强,且由于叠加汇聚效应往往导致距离爆源较远的位点,容易形成局部高压区;环形聚脲-聚氨酯泡沫-海绵复合材料外沿内衬可以有效阻挡绕射波进入头盔内部、减弱绕射波叠加效应,各测点冲击波超压衰减率均可达40%以上;在所采用的入射冲击波(弱冲击波)条件下,冲击波作用过程中形成的间隙越小,防护效果越好;当聚脲-聚氨酯泡沫材料宽度为15 mm时外沿内衬与头模贴合程度最好且防护效果最优,外场爆炸实验结果显示,前额、颅顶和后脑位置超压衰减率分别可高达92.26%、88.82%和87.19%。

Prokaryotic Expression and Identification of Outer Membrane Protein 2 of Chlamydia trachomatis

Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.

Shell炉煤气化飞灰对生物质流化床气化炉壁内/外层积灰的抑制机制

【目的】生物质流化床气化炉壁积灰的抑制机制研究可为设计热效率更高、稳定运行的气化炉提供基础数据。【方法】以自主设计的沉积探针对玉米秸秆和马尾藻气化的炉壁内/外层积灰进行收集,以Shell炉煤气化飞灰(Shell灰)作为添加剂结合IC、ICP-MS、SEM和XRD等分析方法对积灰抑制特性进行定量表征分析。【结果】结果表明玉米秸秆和马尾藻气化内层积灰形成过程中,碱金属/碱土金属硫酸盐和碱金属氯化物的冷凝分别发挥了重要作用。当Shell灰在两种物料中的添加比例(质量比)分别为<15%和<10%时,相对熔点更高的白榴石和正长石等物相的形成抑制了灰颗粒间的黏附,促使外层积灰结构疏松脱落。抑制机理表明外层积灰的碱酸比(R_(B/A))及n(SiO_(2)+Al_(2)O_(3))均能有效反映Shell灰对外层积灰趋势的影响。

Age-related driving mechanisms of retinal diseases and neuroprotection by transcription factor EB-targeted therapy

Retinal aging has been recognized as a significant risk factor for various retinal disorders,including diabetic retinopathy,age-related macular degeneration,and glaucoma,following a growing understanding of the molecular underpinnings of their development.This comprehensive review explores the mechanisms of retinal aging and investigates potential neuroprotective approaches,focusing on the activation of transcription factor EB.Recent meta-analyses have demonstrated promising outcomes of transcription factor EB-targeted strategies,such as exercise,calorie restriction,rapamycin,and metformin,in patients and animal models of these common retinal diseases.The review critically assesses the role of transcription factor EB in retinal biology during aging,its neuroprotective effects,and its therapeutic potential for retinal disorders.The impact of transcription factor EB on retinal aging is cell-specific,influencing metabolic reprogramming and energy homeostasis in retinal neurons through the regulation of mitochondrial quality control and nutrient-sensing pathways.In vascular endothelial cells,transcription factor EB controls important processes,including endothelial cell proliferation,endothelial tube formation,and nitric oxide levels,thereby influencing the inner blood-retinal barrier,angiogenesis,and retinal microvasculature.Additionally,transcription factor EB affects vascular smooth muscle cells,inhibiting vascular calcification and atherogenesis.In retinal pigment epithelial cells,transcription factor EB modulates functions such as autophagy,lysosomal dynamics,and clearance of the aging pigment lipofuscin,thereby promoting photoreceptor survival and regulating vascular endothelial growth factor A expression involved in neovascularization.These cell-specific functions of transcription factor EB significantly impact retinal aging mechanisms encompassing proteostasis,neuronal synapse plasticity,energy metabolism,microvasculature,and inflammation,ultimately offering protection against retinal aging and diseases.The review emphasizes transcription factor EB as a potential therapeutic target for retinal diseases.Therefore,it is imperative to obtain well-controlled direct experimental evidence to confirm the efficacy of transcription factor EB modulation in retinal diseases while minimizing its risk of adverse effects.

Face Painting

Have you ever seen a movie or TV show where an actor is transformed into something?Maybe the person became an animal or a creature from outer space.

某汽车发罩外板零件冲压开裂原因分析及治理研究

针对某汽车发罩外板冲压开裂问题,采用电子拉伸试验机、体视显微镜、金相显微镜、扫描电镜和能谱分析仪等设备对材料的力学性能、成分组织进行检测,采用AUTOFORM冲压成形仿真软件分析模具圆角半径、表面摩擦系数等因素对零件成形效果的影响。结果表明,材料性能优良,但零件成形开裂的主要原因是对应部位的模具上下棱线圆角半径偏小、模具表面摩擦系数较大。通过打磨光滑模具上下棱线圆角、对模具表面进行镀铬处理等措施,降低了材料流动阻力,材料变形更加均匀,使该汽车发罩外板零件冲压开裂问题得到了解决。

Effects of Semi-floating Ring Bearing Outer Clearance on the Subsynchronous Oscillation of Turbocharger Rotor

Semi-floating ring bearing（SFRB） is developed to control the vibration of turbocharger rotor. The outer clearance of SFRB affects the magnitude and frequency of nonlinear whirl motion, which is significant for the design of turbocharger. In order to explore the effects of outer clearance, a transient finite element analysis program for rotor and oil film bearing is built and validated by a published experimental case. The nonlinear dynamic behaviors ofrotor-SFRB system are simulated. According to the simulation results, two representative subsynchronous oscillations excited by the two hearings respectively are discovered. As the outer clearance of SFRB increases from 24 ~tm to 60 pro, the low-frequency subsynchronous oscillation experiences three steps, including a strong start, a gradual recession and a combination with the other one. At the same time, the high-frequency subsynchronous oscillation starts to appear gradually, then strengthens, and finally combines. If gravity and unbalance are neglected, the combination will start starts from high rotor speed and extents to low rotor speed, just like a ＂zipper＂. It is found from the quantitative analysis that when the outer clearance increases, the vibration amplitude experiences large value firstly, then reduction, and suddenly increasing after combination. A useful design principle of SFRB outer clearance for minimum vibration amplitude is proposed： the outer clearance value should be chosen to keep the frequency of two subsynchronous oscillations clearly separated and their amplitudes close.

HopQ-CEACAM复合体在 H.pylori 阳性胃癌中的研究进展

胃癌严重影响人类健康,是全球最常见的恶性肿瘤之一。幽门螺杆菌(Helicobacterpylori,H.pylori)是人胃上皮细胞的特异性定植菌,是引起胃炎、消化性溃疡以及胃癌的重要原因之一。H.pylori凭借其外膜蛋白家族的成员H.pylori外膜蛋白Q(H.pylori outer membrane protein,HopQ)可以与人体宿主细胞表面的人癌胚抗原相关细胞黏附分子1(carcinoembryonic antigen-related cell adhesion molecule 1,CEACAM1)结合,形成Hop-CEACAM1复合体,将细胞毒素相关基因A(cytotoxin-associated gene A,CagA)注入到宿主细胞,发挥毒性作用,产生慢性炎症,若未进行治疗就会导致癌症的发生。本文就Hop-CEACAM1复合体的组成及相互作用以及在H.pylori阳性胃癌中的机制进行综述。

高速列车U型橡胶外风挡低温下收缩性能分析

基于橡胶的低温拉伸试验数据,利用Ansys软件拟合得到橡胶材料Mooney-Rivlin超弹性本构模型参数,并根据3种实际工况对U型橡胶外风挡进行热固耦合仿真分析,研究不同工况对U型橡胶形变的影响;并且对U型橡胶外风挡和3块不同厚度压条预紧的橡胶样件进行低温试验,研究温度及压条厚度对其形变的影响。结果表明,U型橡胶的形变主要因温度变化产生,U型橡胶高度明显减小,而侧壁厚度与橡胶长度的形变量较小;另外,压条的厚度对螺栓孔处橡胶的形变量影响较大,相对于5、6 mm厚度的压条,4 mm压条在螺栓预紧力作用下产生了较大的形变,导致螺栓孔处形变较大,进而增加压条的厚度可有效减小脱孔风险;将有限元仿真数据与低温试验的结果对比发现两者基本一致,表明有限元分析的可行性与低温试验的可靠性。研究结果对U型橡胶外风挡低温下应用的可靠性提供了一定的指导依据。

Characteristics of the Outer Rainband Stratiform Sector in Numerically Simulated Tropical Cyclones:Lower-Layer Shear versus Upper-Layer Shear

Idealized numerical simulations are conducted in this study to comparatively investigate the characteristics of the stratiform sector in the outer rainbands of tropical cyclones(TCs)in lower-and upper-layer vertical wind shear(VWS)with moderate magnitude.Consistent with the results in previous studies,the outer rainband stratiform sector of the TCs simulated in both experiments is generally located downshear left.Upper-layer VWS tends to produce stronger asymmetric outflow at upper levels in the downshear-left quadrant than lower-layer shear.This stronger asymmetric outflow transports more water vapor radially outward from the inner core to the outer core at upper levels in the downshear-left quadrant in the upper-layer shear experiment.More depositional growth of both graupel and cloud ice thus occurs downshear left in upper layers in the outer core,yielding more diabatic heating and stronger upward motions,particularly in the stratiformdominated part of the stratiform sector in the upper-layer shear experiment.Resultingly,a better-organized stratiform sector in the outer rainbands is found in the upper-layer VWS experiment than in the lower-layer VWS experiment.The diabatic heating associated with the stratiform sector produces strong midlevel outflow on the radially inward side of,and weak midlevel inflow on the radially outward side of,the heating core,with lower-level inflow beneath the midlevel outflow and upper-level inflow above.The upper-layer VWS tends to produce a deeper asymmetric inflow layer in the outer rainband stratiform sector,with more significant lower-level inflow and tangential jets in the upper-layer VWS experiment.

DS-CDMA system outer loop power control and improvement for multi-service

When a new user accesses the CDMA system, the load will change drastically, and therefore, the advanced outer loop power control （OLPC） technology has to be adopted to enrich the target signal interference ratio （Silt） and improve the system performance. The existing problems about DS-CDMA outer loop power control for multi-service are introduced and the power control theoretical model is analyzed. System simulation is adopted on how to obtain the theoretical performance and parameter optimization of the power control algorithm. The OLPC algorithm is improved and the performance comparisons between the old algorithm and the improved algorithm are given. The results show good performance of the improved OLPC algorithm and prove the validity of the improved method for multi-service.