ATP-induced Ca<Superscript>2+</Superscript>-signalling mechanisms in the regulation of mesenchymal stem cell migration

The ability of cells to migrate to the destined tissues or lesions is crucial for physiological processes from tissue morphogenesis, homeostasis and immune responses, and also for stem cell-based regenerative medicines. Cytosolic Ca²⁺ is a primary second messenger in the control and regulation of a wide range of cell functions including cell migration. Extracellular ATP, together with the cognate receptors on the cell surface, ligand-gated ion channel P2X receptors and a subset of G-protein-coupled P2Y receptors, represents common autocrine and/or paracrine Ca²⁺ signalling mechanisms. The P2X receptor ion channels mediate extracellular Ca²⁺ influx, whereas stimulation of the P2Y receptors triggers intracellular Ca²⁺ release from the endoplasmic reticulum (ER), and activation of both type of receptors thus can elevate the cytosolic Ca²⁺ concentration ([Ca²⁺]_c), albeit with different kinetics and capacity. Reduction in the ER Ca²⁺ level following the P2Y receptor activation can further induce store-operated Ca²⁺ entry as a distinct Ca²⁺ influx pathway that contributes in ATP-induced increase in the [Ca²⁺]_c. Mesenchymal stem cells (MSC) are a group of multipotent stem cells that grow from adult tissues and hold promising applications in tissue engineering and cell-based therapies treating a great and diverse number of diseases. There is increasing evidence to show constitutive or evoked ATP release from stem cells themselves or mature cells in the close vicinity. In this review, we discuss the mechanisms for ATP release and clearance, the receptors and ion channels participating in ATP-induced Ca²⁺ signalling and the roles of such signalling mechanisms in mediating ATP-induced regulation of MSC migration.     

Intracellular localization of DR5 and related regulatory pathways as a mechanism of resistance to TRAIL in cancer

TNF-related apoptosis-inducing ligand (TRAIL) is a prominent cytokine capable of inducing apoptosis. It can bind to five different cognate receptors, through which diverse intracellular pathways can be activated. TRAIL’s ability to preferentially kill transformed cells makes it a promising potential weapon for targeted tumor therapy. However, recognition of several resistance mechanisms to TRAIL-induced apoptosis has indicated that a thorough understanding of the details of TRAIL biology is still essential before this weapon can be confidently unleashed. Critical to this aim is revealing the functions and regulation mechanisms of TRAIL’s potent death receptor DR5. Although expression and signaling mechanisms of DR5 have been extensively studied, other aspects, such as its subcellular localization, non-signaling functions, and regulation of its membrane transport, have only recently attracted attention. Here, we discuss different aspects of TRAIL/DR5 biology, with a particular emphasis on the factors that seem to influence the cell surface expression pattern of DR5, along with factors that lead to its nuclear localization. Disturbance of this balance apparently affects the sensitivity of cancer cells to TRAIL-mediated apoptosis, thus constituting an eligible target for potential new therapeutic agents.     

基于信息共享角度的团购策略研究

随着社交网络的崛起,信息共享成为消费者行为的一个重要特征. 本文基于信息共享角度,在考虑消费者特基础上对商家的团购策略进行设计. 研究表明,随着信息共享难度或低信息消费者比例的增大,团购折扣价格家利润逐渐减小,但混合团购个人购买价格却先增后减; 同时,反从众、不从众和从众消费者的比例以及从性导致的保留价值差直接影响最优的团购策略; 而较高比例的等待敏感型消费者也会导致团购折扣价格的减小. 另外,只有当高低信息消费者之间的信息差较大且信息共享难度不大时,团购策略才优于传统边际策略.     

Description of rotational properties of the superheavy nucleus ^256,258,260Rf by projected shell model

Band structure of the Z = 104 nucleus 256Rf has been a recent research focus in nuclear physics. We performed projected shell model calculations for this and some other neighboring Rf isotopes. Specifically, we studied rotational properties of these nuclei and showed that variations in dynamic moment of inertia were sensitive to single-particle structures, which may be useful information for locating the anticipated island of stability. Electromagnetic transition properties were also calculated, and measurable quantities were predicted for further experimental test.     

河北省高校区域创新体系服务调查研究

高校是区域创新体系的重要主体要素。近年来,高校凭借其雄厚的科研基础和集聚的科研人才,迅速成为推动区域经济和社会发展的主要生长点和辐射源。研究通过对河北省高校为区域创新体系发展提供人才培养培训服务、平台服务和资源保障的实际情况,总结高校服务取得的成绩和存在的问题,并提出相关发展对策和建议。     

Citizenship and Voluntarism: A Meaningful Combination or the Basis for Exploitative Relationships?

The author starts from the observation that citizenship and voluntarism are contested terms with diverse meanings. They have also been appropriated by politicians of various persuasions and imbued with meanings associated with ‘feel good’ factors that emphasize serving in a community. Therefore, voluntarism has the potential to continue the exclusion of minority groups, marginalized individuals and collective groupings at the expense of their citizenship rights, particularly those identified by Hannah Arendt as the ‘right to have rights’ that have been endorsed through public policy but today are being undermined by the ‘age of austerity’ in publicly funded welfare states. Against the background of the political context of UK, and the public rhetoric on the ‘Big Society’, the author examines whether citizenship discourses allied with voluntarism support a meaningful endorsement of altruistic solidarity or whether they endorse exploitative relationships under the guise of meeting the public needs.     

我国扫描电镜产业的发展与预测研究

长期以来,全球电镜研发一直是美国、日本和德国三足鼎立,其中以日本日立公司、日本电子公司、美国FEI公司以及德国蔡司公司表现最为突出。而我国扫描电镜主要依靠进口,本文对韩国、日本、美国、德国等国家的产业发展经验进行研究,结合我国实际情况,分析我国扫描电镜产业的发展趋势,并提出促进我国扫描电镜产业发展的对策建议。     

A Hyper-Erlang Jump-Diffusion Process and Applications in Finance

This paper studies the first passage time problem for a reflected two-sided jump-diffusion risk model with the jumps having a hyper-Erlang distribution. The authors give the explicit closed-form expression for the joint Laplace transform of the first passage time and the overshoot for the reflected process. Finally, the formula is applied to the ruin problem under the barrier dividend strategy and the pricing of the Russian option.     

一种基于不确定度的证据冲突识别方法

从高度冲突证据对D-S证据理论的应用约束出发,针对几种常用冲突度量方法存在的问题,定义了描述证据自身特征的不确定度,将证据冲突涵义从证据间不一致扩展到证据内外,给出基于不确定度的证据冲突多元度量,并为增强冲突的识别效果提出最大差异度的冲突处理方法.验证分析得出:本文给出的度量方法能够有效表征证据间的冲突程度,最大冲突差异度的处理实现了证据冲突识别的显著化,在证据冲突度量与识别中具有很好的普适性和有效性.