基于40Cr高温动态力学性能的磨削表面动态再结晶行为

通过分离式霍普金森压杆(SHPB)实验得到了40Cr合金钢在高温高应变率下真应力-真应变曲线，据此确定了材料发生动态再结晶的临界条件.采用解析法和实验法分别求解了磨削强化层的温度场和塑性应变场分布.结果表明，磨削强化层在磨削深度方向具有较大的温度和塑性应变梯度;150μm强化层内会发生奥氏体转变;磨削表面最高温度可达1060℃.在磨削亚表面60μm内会产生剧烈的塑性变形，达到了再结晶的临界条件.较大的磨削深度使磨削强化层塑性应变增大，再结晶现象越充分，微观组织细化程度越高.     

基于"人"的机构知识库可持续发展策略研究

介绍了机构知识库的建设和研究情况,分析了影响机构知识库可持续发展的因素,从建设形式、激励政策、资金来源、与其他机构的协调、机构知识库的宣传、内容建设、人员配备和培训等方面论述了促进机构知识库可持续发展的对策.     

Blockage of the NLRP3 inflammasome by MCC950 improves anti-tumor immune responses in head and neck squamous cell carcinoma

The NLRP3 inflammasome is a critical innate immune pathway responsible for producing active interleukin (IL)-1β, which is associated with tumor development and immunity. However, the mechanisms regulating the inflammatory microenvironment, tumorigenesis and tumor immunity are unclear. Herein, we show that the NLRP3 inflammasome was over-expressed in human HNSCC tissues and that the IL-1β concentration was increased in the peripheral blood of HNSCC patients. Additionally, elevated NLRP3 inflammasome levels were detected in tumor tissues of Tgfbr1/Pten 2cKO HNSCC mice, and elevated IL-1β levels were detected in the peripheral blood serum, spleen, draining lymph nodes and tumor tissues. Blocking NLRP3 inflammasome activation using MCC950 remarkably reduced IL-1β production in an HNSCC mouse model and reduced the numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). Moreover, inhibiting NLRP3 inflammasome activation increased the numbers of CD4⁺ and CD8⁺ T cells in HNSCC mice. Notably, the numbers of exhausted PD-1⁺ and Tim3⁺ T cells were significantly reduced. A human HNSCC tissue microarray showed that NLRP3 inflammasome expression was correlated with the expression of CD8 and CD4, the Treg marker Foxp3, the MDSC markers CD11b and CD33, and the TAM markers CD68 and CD163, PD-1 and Tim3. Overall, our results demonstrate that the NLRP3 inflammasome/IL-1β pathway promotes tumorigenesis in HNSCC and inactivation of this pathway delays tumor growth, accompanied by decreased immunosuppressive cell accumulation and an increased number of effector T cells. Thus, inhibition of the tumor microenvironment through the NLRP3 inflammasome/IL-1β pathway may provide a novel approach for HNSCC therapy.     

Microsatellite instability in gastric cancer: molecular bases,clinical perspectives,and new treatment approaches

Gastric cancer is one of the most aggressive malignancies, with limited treatment options in both locally advanced and metastatic setting, resulting in poor prognosis. Based on genomic characterization, stomach tumour has recently been described as a heterogeneous disease composed by different subtypes, each of them with peculiar molecular aspects and specific clinical behaviour. With an incidence of 22% among all western gastric tumour cases, stomach cancer with microsatellite instability was identified as one of these subgroups. Retrospective studies and limited prospective trials reported differences between gastric cancers with microsatellite stability and those with instability, mainly concerning clinical and pathological features, but also in regard to immunological microenvironment, correlation with prognostic value, and responses to treatment. In particular, gastric cancer with microsatellite instability constitutes a small but relevant subgroup associated with older age, female sex, distal stomach location, and lower number of lymph-node metastases. Emerging data attribute to microsatellite instability status a favourable prognostic meaning, whereas the poor outcomes reported after perioperative chemotherapy administration suggest a detrimental role of cytotoxic drugs in this gastric cancer subgroup. The strong immunogenicity and the widespread expression of immune-checkpoint ligands make microsatellite instability subtype more vulnerable to immunotherapeutic approach, e.g., with anti-PD-L1 and anti-CTLA4 antibodies. Since gastric cancer with microsatellite instability shows specific features and clinical behaviour not overlapping with microsatellite stable disease, microsatellite instability test might be suitable for inclusion in a diagnostic setting for all tumour stages to guarantee the most targeted and effective treatment to every patient.     

General mechanisms of drought response and their application in drought resistance improvement in plants

Plants often encounter unfavorable environmental conditions because of their sessile lifestyle. These adverse factors greatly affect the geographic distribution of plants, as well as their growth and productivity. Drought stress is one of the premier limitations to global agricultural production due to the complexity of the water-limiting environment and changing climate. Plants have evolved a series of mechanisms at the morphological, physiological, biochemical, cellular, and molecular levels to overcome water deficit or drought stress conditions. The drought resistance of plants can be divided into four basic types-drought avoidance, drought tolerance, drought escape, and drought recovery. Various drought-related traits, including root traits, leaf traits, osmotic adjustment capabilities, water potential, ABA content, and stability of the cell membrane, have been used as indicators to evaluate the drought resistance of plants. In the last decade, scientists have investigated the genetic and molecular mechanisms of drought resistance to enhance the drought resistance of various crops, and significant progress has been made with regard to drought avoidance and drought tolerance. With increasing knowledge to comprehensively decipher the complicated mechanisms of drought resistance in model plants, it still remains an enormous challenge to develop water-saving and drought-resistant crops to cope with the water shortage and increasing demand for food production in the future.     

基于成像算子优化的微震逆时定位方法

针对目前微震逆时定位成像存在的问题,提出一种优化后的成像算子,对模型数据进行抗噪性、误差速度以及检波器分布和数量进行测试,并提出采用峰度值作为定位成像结果的评价标准。结果表明,优化后的成像条件在定位能量聚焦程度和成像分辨率上都得到了提升,对含速度误差和含噪微震数据都有较好的成像结果,并且对检波器的分布和数量有较好的适应性,取得了较为理想的定位效果。     

数学专业师范生教学技能的调查研究--以四川文理学院为例

教学技能是教师最重要的专业素质，是师范生在大学期间需要掌握的基础职业技能。通过调查研究表明，数学专业大学生教学基本功发展不平衡，不同年级学生的教学技能水平存在显著差异。教学实践、课改认知、教学交流、自主练习是影响教学技能的四个主因子。男女生在表达技能、教学设计技能、几何作图技能等方面差异显著，而在教材分析、多媒体使用方面不存在显著性差异。要通过完善教学技能培养机制，夯实师范基础技能培养，改革教学技能培养方式等途径，合力提高师范生的教学技能，增强就业竞争力。     

Junctional adhesion molecule-A: functional diversity through molecular promiscuity

Cell adhesion molecules (CAMs) of the immunoglobulin superfamily (IgSF) regulate important processes such as cell proliferation, differentiation and morphogenesis. This activity is primarily due to their ability to initiate intracellular signaling cascades at cell–cell contact sites. Junctional adhesion molecule-A (JAM-A) is an IgSF-CAM with a short cytoplasmic tail that has no catalytic activity. Nevertheless, JAM-A is involved in a variety of biological processes. The functional diversity of JAM-A resides to a large part in a C-terminal PDZ domain binding motif which directly interacts with nine different PDZ domain-containing proteins. The molecular promiscuity of its PDZ domain motif allows JAM-A to recruit protein scaffolds to specific sites of cell–cell adhesion and to assemble signaling complexes at those sites. Here, we review the molecular characteristics of JAM-A, including its dimerization, its interaction with scaffolding proteins, and the phosphorylation of its cytoplasmic domain, and we describe how these characteristics translate into diverse biological activities.     

Current knowledge on exosome biogenesis and release

Exosomes are nanosized membrane vesicles released by fusion of an organelle of the endocytic pathway, the multivesicular body, with the plasma membrane. This process was discovered more than 30 years ago, and during these years, exosomes have gone from being considered as cellular waste disposal to mediate a novel mechanism of cell-to-cell communication. The exponential interest in exosomes experienced during recent years is due to their important roles in health and disease and to their potential clinical application in therapy and diagnosis. However, important aspects of the biology of exosomes remain unknown. To explore the use of exosomes in the clinic, it is essential that the basic molecular mechanisms behind the transport and function of these vesicles are better understood. We have here summarized what is presently known about how exosomes are formed and released by cells. Moreover, other cellular processes related to exosome biogenesis and release, such as autophagy and lysosomal exocytosis are presented. Finally, methodological aspects related to exosome release studies are discussed.