额叶肿瘤患者短时记忆障碍的研究

额叶在大脑半球中占有很大比重(1/3),组成大脑的前部,是大脑发育过程中最后发育的组织。至今,对额叶功能的研究,意见尚有分歧。认为额叶与人的高级整合功能有关,Jefferson 反对高级机能定位在额叶区。不少作者对额叶健忘症进行了研究,认为额叶肿瘤患者出现的记忆障碍,具有非特殊通道性质,影响整个记忆活动; Clark 等认为额叶病变造成患者缺乏意识指向性,不能按指导语进行回答,不能按计划组织安排动作顺序,以完成有目的的行为,并且改变朝

Screening Proteins that Interact with Rab39A via Yeast Two-hybrid System

目的:应用酵母双杂交方法,寻找可能与rAb39A相互作用的蛋白。方法:采用醋酸锂转化法将诱饵蛋白rAb39A转入AH109酵母菌,WESTErn blOTTIng检测蛋白表达情况,检测诱饵载体有无毒性和自激活能力,筛选出的蛋白通过免疫荧光法进一步验证。结果:获得12个与rAb39A相互作用的候选蛋白,免疫荧光法证明rAb39A与ATrn、TIfA、ITgb1蛋白确实存在互作关系。结论:筛选出的蛋白主要与细胞生长、肿瘤细胞形成有关,为rAb39A功能的研究提供了重要线索。Objective:Using Yeast-two-hybrid method to inquire proteins interacting with Rab39A.Method:The bait plasmid pGBKT7-Rab39A was transfected into AH109 yeast,checking proteins expression,checking the auto-activity and toxicity of recombined plasmid,the interactions were further confirmed with immunofluorescence experiment.Result:12 positive proteins possibly interacting with Rab39A were obtained.The interactions of Rab39A with ATRN,TIFA,ITGB1 were further confirmed by immunofluorescence.Conclusion:The screened proteins have relation with cell growth,cancer cell formation,providing important clues for further investigation of biological function of Rab39A.国家自然科学基金面上项目(“新Rab蛋白对甘露糖-6-磷酸受体及其介导的溶酶体蛋白质运输路径的调控作用及机制研究”;No.30971442、31071176); 福建省自然科学基金项目(“小GTP酶Rab蛋白在人类乳腺癌发生过程中的调控作用”;2010J01234)资

Discussion on the Factors Stimulating Curiosity Through the Analysis of Exhibit Types and Characteristics of Science and Technology Museums

作为开展科普教育、提升公民科学素质的重要场所,科技馆在激发观众好奇心方面具有独特优势。科技馆展品作为科普主要传播载体,其不同展示类型和特征差异,对激发观众注意力和好奇心的程度也有所不同。本文通过文献研究等方式,分析梳理科技馆展品类型及特征,以流动科普展品为研究对象,重点从学科领域、展示形式、感官体验、人际关系、交互方式等维度进行探讨,依据好奇心相关理论,找寻规律特点,进而提出影响展品激发好奇心的潜在因素,为更好地指导科技馆展品的设计与开发提供理论依据。</p

Drag reduction using riblets downstream of a high Reynolds number inclined forward step flow

Micro-riblet is an efficient passive method for controlling turbulent boundary layers, with the potential to reduce frictional drag. In various applications within the transportation industry, flow separation is a prevalent flow phenomenon. However, the precise drag reduction performance of riblets in the presence of flow separation remains unclear. To address this, an inclined forward step model is proposed to investigate the interaction between riblet and upstream flow separation. The large eddy simulation (LES) method is applied to simulate the flow over geometries with different step angles and riblet positions. The results show riblets still reduce wall frictional resistance when subjected to the upstream flow separation. Remarkably, as the angle of the step increases from 0 degrees to 30 degrees, the drag reduction experiences an increment from 9.5% to 12.6%. From a turbulence statistics standpoint, riblets act to suppress the Reynold stress in the near-wall region and dampen ejection motions, thus weakening momentum exchange. Quadrant analysis reveals that with the augmentation of flow separation, the Q2 motion within the flow field intensifies, subsequently enhancing the riblet-induced drag reduction. Moreover, the position of the rib lets has a significant impact on the pressure drag. Riblets close to the point of separation enhance flow separation, altering the surface pressure distribution and thus increasing the resistance. The results reveal that when the riblets are positioned approximately 160 riblet heights away from the step, their effect on the upstream flow separation becomes negligible. The precise performance of riblets under complex flow conditions is important for their practical engineering application

First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring

In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow