疏血通抑制Bim依赖的小脑颗粒神经元凋亡

目的探究疏血通及其主要成分水蛭素对Sprague-Dawley（SD）大鼠小脑颗粒神经元（CGNs）凋亡的影响及机制。方法体外成熟7 d的CGNs分为存活对照组（用含K+浓度为25 mmol/L的培养基，即25 K组）、凋亡组（用含K+浓度为5 mmol/L的培养基，即5 K组）、以1/50、1/40、1/30、1/20、1/10浓度（稀释50、40、30、20、10倍）疏血通注射液处理组（25 K以及5 K合并疏血通处理组）以及对应不同浓度（2 U/mL、2.5 U/mL、3.34 U/mL、5 U/mL、10 U/mL）水蛭素处理组（25 K以及5 K合并水蛭素处理组），用Hoechst染色法观察并统计凋亡率。在蛋白印迹实验中，在25 K和5 K条件下用1/50、1/10浓度疏血通注射液以及对应2 U/mL、10 U/mL浓度水蛭素处理细胞，用Western blot法检测Cleaved Caspase-3、Bim、VEGF的表达水平。结果核染色结果显示，与25 K存活对照组比较，5 K凋亡组凋亡率增加；与25 K存活对照组比较，不同浓度疏血通注射液与水蛭素处理细胞后凋亡率无明显变化；与5 K凋亡组比较，不同浓度疏血通注射液与水蛭素处理细胞后凋亡率下降，且随着浓度的升高，凋亡率下降越明显。Western blot结果显示，与5 K凋亡组比较，不同浓度疏血通与水蛭素处理细胞后Cleaved Caspase-3、Bim蛋白表达水平均下降，VEGF蛋白表达水平升高。结论疏血通及其主要成分水蛭素通过抑制Bim表达，进而抑制线粒体依赖的小脑颗粒神经元凋亡

中国物理海洋学研究70年：发展历程、学术成就概览

本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

应用微生物与秸秆降低鸡粪氨气释放量(英文)

为减轻大量禽畜废弃物中氨气流失对环境的污染,研究和优化了微生物与秸秆等辅料对氨气释放量的影响。结果表明,F468、M1?M9等除臭微生物能显著降低氨气的释放量,其中F468是最优微生物,其它微生物与F468的配伍并没有显著增强F468降低氨气释放量的能力,有些微生物还降低了其能力,因此选择单一微生物法降低氨气释放量。单独添加辅料对降低氨气的释放影响较小,辅料与微生物的配伍可大量降低氨气的释放量。5%的F468与10%的秸秆配伍在1?5 d降低88%的释放量。应用微生物与秸秆不仅降低氨气挥发对环境的危害,也是秸秆资源化利用的有效途径之一

Study on the movement behavior of ping-pong ball on water surface under microgravity

In a microgravity environment, where gravity is almost absent, surface tension plays a dominant role in the behavior of fluid motion. The motion of fluids within storage tanks can lead to significant oscillations of the tank itself or even the entire vehicle, posing substantial safety risks. Solid foam particle anti-sloshing technology represents a novel research topic in addressing this issue. The anti-sloshing technology using solid foam particles is a novel research topic. In this experiment, ping-pong balls were used to simulate individual foam particles, and a transparent liquid tank was designed to observe their motion. Two different hydrophobic materials were applied to the surface of the balls to alter their surface tension in water. A drop tower was used to create a microgravity environment, and the motion of the balls in water under microgravity was recorded with a camera. Both static and dynamic analyses were conducted on the balls under normal gravity and microgravity conditions, considering water resistance, surface tension, and added mass forces. The control equations for the position and velocity of the ball's center of mass were derived. The experimental results showed that under microgravity, hydrophilic balls tend to submerge into the water, while hydrophobic balls move upwards, away from the water surface. The equilibrium adsorption position of the hydrophilic balls differed significantly between microgravity and normal gravity conditions, with noticeable oscillatory movement in the vertical direction. The experimental results showed good agreement with the dynamic model

Turbulence structure of the Rayleigh-Bénard convection using liquid CO₂ as working fluid

We studied the evolution of flow structures and large-scale circulations (LSC) in Rayleigh-B & eacute;nard convection (RBC) using liquid carbon dioxide as the working medium. In this experiment, a transparent sapphire pressure vessel with observable internal flow was designed, and different temperature differences were applied between the upper and the lower surfaces of the fluid to obtain different Rayleigh numbers (Ra). We employed proper orthogonal decomposition and reconstruction to extract internal flow structures from the shadowgraphy images. We used optical flow techniques to acquire the velocity field of the flow, and we reconstructed the temperature field inside the supercritical fluid using the relationship between shadowgraphy images and refractive index. It is clearly observed that the RBC begins to produce different flow structures under a small temperature difference of 0.4 degrees C. As the number of Ra increases, the number and the speed of plumes increase, and the morphology of plumes gradually becomes elongated. When Ra exceeds a certain critical value, an LSC structure appears in the flow field, and the plumes translate laterally with the large-scale circulation, and the disorder of the vortex structure in the central flow region increases significantly. Three typical flow structures were observed: (1) single plume, (2) thermal boundary layer traveling waves, and (3) Rayleigh-Taylor instability waves. We believe that the traveling wave structure is the precursor to the single plume. The temperature field analysis of the three structures was carried out, and the velocity of the typical plume was calculated by the optical flow method. It was found that LSC transitioned from oval to square shape with the increase in Ra, and the internal plume Reynolds number slowly increased with the increase in Ra. By the in-depth study of the thermal turbulence characteristics and the coherent structure evolution law of RBC, this paper provides experimental support for revealing the mechanism of enhanced heat transfer in energy system with a liquid CO2 working fluid

二氧化碳超临界相变过程中Rayleigh–Bénard对流的实验研究

超临界流体是一种极端条件下（温度与压力均处于临界点以上）的非常态流体。浮力驱动的超临界流体Rayleigh–Bénard(RB)对流则是一种新的非线性热对流体系，其浮力作用不符合Boussinesq近似，且在温差的作用下物性在临界点附近出现剧烈畸变并伴随着丰富的流动与相变耦合过程。本实验设计了可承载超临界二氧化碳（SCO_2）的透明蓝宝石压力容器，建立竖直温度梯度作用下的超临界流体RB对流，观测不同温差作用下的流动结构和超临界相变过程并通过图像互相关算法计算“雾化”液滴的速度场。实验采用铂电阻测温，并精确控制容器上下端的温差，研究SCO_2在线性降温过程中多种流态与速度场的演化。在线性降温过程中，SCO_2经历超临界流动、跨临界流动和气液两相流动3个典型过程。跨临界流动是相变与浮力热对流的强耦合过程，导致超临界二氧化碳RB对流具有多态的非稳态流动。实验结果表明：超临界RB对流对温差极为敏感，温差越大则超临界域内的对流越剧烈；随着温度的降低，雾化的液滴不断凝聚，形成丰富的多层流动结构，并最终向气液两相流动演化