爷爷的菜园

正爷爷的菜园不大,种的蔬菜可不少。有穿着紫袍的茄子,它们戴着绿帽子,像是参加晚会的贵妇人一样。玉米的长势最好,一株株像小士兵一样,昂首挺胸地站在田边,神气十足。要是有不认识的人靠近它,它会举起红缨枪,瞄准入侵者。西红柿挂满枝头,像一盏盏红灯笼,照亮了整个菜园。豇豆最文静,像亭亭玉立的少女,一阵风吹来,摆动纤细的身体,翩翩起舞,很是好看。辣椒最威风,它们有的穿着碧绿的外套,有的穿着大红袍,很是耀眼,生怕别人看不到它们美丽的衣裳。朝天椒虽然不太显眼,但可爱炫耀自己了,像骄傲的公主。     

草根的优雅——写在三月,写给这些年的成长

你路过了你的风景,也行使了你应该行使的里程,不要心有不甘,不要挂档倒退,把该记住的记住,该剔除的剔除。三月,注定是属于女人的,草长莺飞,季节变迁,城市里弥漫着对女人的关注和赞美。2010年1月,我获得了成都市2009年度第三届职业丽人提名奖,3月,又获得了2010年十大魅力女川商。同时,又因为工作的原因,获得了总公司记大功的奖励。     

解放思想 高移目标 推动学校事业科学发展

在学校事业发展的新阶段,必须解放思想,高移目标,不断提升人才培养工作水平,不断提升富民强校水平,努力实现办学层次的新提升和办学空间的新拓展。要以科学发展观为指导,坚持稳中求进,坚持好字优先,坚持改革创新,坚持以人为本,夯实基础,彰显特色,增创新的发展优势。要上下团结一心,协调一致,形成合力,共同担负起促进学校事业又好又快发展的重任。     

阿拉斯加——让人钟爱一生的风景地

走进阿拉斯加,仿佛走进了气势恢弘的天然画廊。不同的季节,不同的时辰,这里呈现着不同的景色,有的色彩斑斓,如同浓彩重墨的油画;有的古朴俊秀,犹如水墨丹青的国画;有的刚劲有力,形如对比强烈的版画;有的清新雅致,恰似灵动飘逸的水彩画。无论黄昏还是黎明,无论是晴空万里还是烟雨朦胧,阿拉斯加的每个角落都有一种美丽,让你怦然心动,让你流连忘返,让你想把它放进自己的梦里,千年不醒。     

基于蓝牙的手持GPS接收器的设计

GPS蓝牙接收器是一种便携式、电池供电的手持设备,采用蓝牙接口,通过无线技术将GPS信号提供给具有蓝牙接口的显示装置,能够为用户提供定位和导航信息.文章根据手持GPS蓝牙接收器的特点,进行系统设计,从硬件、软件两方面进行论述,提出了一种实现方案, 实验的结果说明设计方案是可行的,具有成本低,产品体积小,性能稳定,易生产和便于改进等主要特点,可满足用户的需要,有一定的发展空间.     

中国人物

一般来说,知道他,主要是通过两个故事以及这么一个成语——运筹帷幄之中,决胜千里之外。至于他是如何运筹又是如何决胜的,一般人就不会问了,无非权谋计算而已。他的第一个故事是,作为韩国的贵公子,为了替他的韩国报仇,他悉以家财,求得力士,制一百多斤的铁锥,埋伏在那博浪沙,冒险刺杀秦始皇,可惜那     

论教师在新课程背景下的角色定位

随着新一轮基础教育课程改革的全面实施,教师的角色发生了重大的转变.教师应提高认识,创造条件,认真履行好学习的促进者,言传身教的示范者,集体活动的组织者,心理健康的维护者,人际关系的协调者,课程的开发者,教育教学的研究者,终身学习者等多重角色职能.要实现角色转变,必须加强自我更新和培训.     

母爱

春天,母爱犹如和煦的微风,拂过稚嫩的花瓣;夏天,母爱犹如冰冻的冷饮,凉爽炽热的身体;秋天,母爱犹如金黄的落叶,点亮前进的道路;冬天,母爱犹如顽强的种子,等待生     

2009年度中国直销6大庆典

5周年,15周年,50周年……每一次直销企业的周年庆典,都向我们展示着直销企业的一次质变,象征着直销行业的一次成长。走过嗷嗷待哺的年月,走过激情燃烧的岁月,周年庆典的这些数字,都预示着直销企业已步入成熟稳重的中青年时代,开始在中国市场中散发出独特的魅力。周年庆典是实力的展示,是自我的激励,是成长的荣耀,同时也是一个平台:借着一幕幕的精彩表演,甚至是员工自己编排的节目,     

玉树的民风

玉澍偶地名,使人发生一样美感,为什么呢?我国的文人描写女人的漂亮,多喜欢用个玉字,所谓「亭亭玉立,所谓「燕度佳人,美者颜如玉」,都说不了「玉字,所以玉树纵里面的一个玉字,已很容易使人以为它是一个风景美丽的地方,虽不敢奢望如杭州的西湖,至少也如山东的青岛吧,其实单一个玉字,不能尽其妙处,它是玉树呀,玉的树是多么实真的东西呵,所以玉树二字不特     

Transient expression of IL-2 receptor precedes the differentiation of immature thymocytes

The growth of mature T lymphocytes after activation by antigen is regulated by the binding and endocytosis of interleukin-2 (IL-2). In the thymus, approximately 50% of adult thymocytes that carry neither the CD4 nor the CD8 antigen and day 14-15 fetal CD4-8- thymocytes express receptors for IL-2(IL-2R). The CD4-8- (double-negative) subpopulation of thymocytes contains the precursors of cells that can differentiate along an unknown pathway into thymocytes bearing either CD8 or CD4, with the characteristics of mature T lymphocytes. The basis for IL-2R expression by double-negative thymocytes is unclear as they appear to lack a functional T-cell receptor/CD3 complex through which activation of peripheral T cells is mediated. The argument for a role for IL-2 in thymocyte differentiation has also been complicated by conflicting reports on the inability or capability of double-negative thymocytes to respond to IL-2 in vitro. At present, both the nature of the stimuli within the thymic micro-environment which induce IL-2R expression and its relevance to thymocyte differentiation are not known. We show here that the IL-2R-bearing subset has a greater potential to differentiate into phenotypically mature T lymphocytes than do IL-2R-negative thymocytes. In addition, progeny of IL-2R-negative donor cells transiently express IL-2R in the thymuses of adoptive hosts before generating CD8 and/or CD4-positive thymocytes. These results identify the IL-2R-positive cells as a more differentiated double-negative thymocyte subset on the pathway to mature T lymphocytes.     

Interconversion of CD45R subsets of CD4 T cells in vivo

T lymphocytes express multiple forms of the leukocyte common antigen CD45, transcribed by alternative usage of leukocyte-common antigen exons 4-6. Species-specific monoclonal antibodies against restricted epitopes (CD45R) of the antigen subdivide CD4 T cells into reciprocal subsets expressing either the high molecular weight isoforms CD45RA or RB or a molecule in which exons 4-6 have been spliced out (CD45R0). CD45R+ or RB+ CD4 T cells are potent in graft-versus-host reactions, and interleukin-2 related activities, whereas the CD45R0+ subset responds in vitro to recall antigens and provides help for antibody synthesis. It is unclear whether CD45R subsets derive from separate lineages, or are products of unidirectional or reversible differentiation. We show by transferring CD45R+ or CD45R- allotype-marked CD4 T cells into athymic nude rats that both subsets routinely generate cells of the opposite phenotype with a function that follows phenotype, not parentage. The recent equation of CD45R subsets as maturation stages representing 'naive' and 'memory' T cells is difficult to reconcile with this finding.     

外源性透明质酸减少R5-HIV对CD4~+T细胞感染的研究（英文）

目的探讨外源性透明质酸(HA)是否可以降低巨噬细胞嗜性(CCR5依赖,R5)人类免疫缺陷病毒(HIV)对CD4+T细胞的感染性。方法首先用TZM-bl细胞和未受刺激的CD4+T细胞检测,以评估外源性透明质酸(HA)能否降低R5-HIV的感染性。用透明质酸酶去处理未受刺激的CD4+T细胞,研究内源性HA对R5-HIV感染性的影响。最后,同时测量外源性和内源性透明质酸(HA)对R5-HIV对CD4+T细胞粘和力的影响。结果 (1)100μg外源性HA处理能够显著降低R5-HIV感染TZM-bl细胞和未受刺激的CD4+T细胞(P<0.001)。(2)透明质酸酶处理可增强HIV的感染性,但是如果加上100μg外源性HA可以逆转透明质酸酶的处理(P<0.001)。(3)100μg外源性HA可以减少R5-HIV对CD4+T细胞的粘和力,透明质酸酶处理可以提高R5-HIV对CD4+T细胞的粘和力(P<0.001)。结论外源性HA减少R5-HIV对未受刺激的CD4+T细胞的感染性,而透明质酸酶处理可以提高R5-HIV对CD4+T细胞的粘和力,能增强R5-HIV对CD4+T细胞的感染性。     

Lifespan of human lymphocyte subsets defined by CD45 isoforms.

The lifespan of thymic-derived or T lymphocytes is of particular interest because of their central role in immunological memory. Is the recall of a vaccination or early infection, which may be demonstrated clinically up to 50 years after antigen exposure, retained by a long-lived cell, or by its progeny? Using the observation that T lymphocyte expression of isoforms of CD45 corresponds with their ability to respond to recall antigens, we have investigated the lifespan of both CD45R0 (the subset containing responders, or 'memory' cells) and CD45RA (the unresponsive, or 'naive' subset) lymphocytes in a group of patients after radiotherapy. Here we report rapid loss of unstable chromosomes from the CD45R0 but not the CD45RA pool. Immunological memory therefore apparently resides in a population with a more rapid rate of division. Differing survival curves for the two subsets are best described by a model in which there is also reversion in vivo from the CD45R0 to the CD45RA phenotype. Expression of CD45R0 in T cells may therefore be reversible.     

Exploiting a natural conformational switch to engineer an interleukin-2 'superkine'

The immunostimulatory cytokine interleukin-2 (IL-2) is a growth factor for a wide range of leukocytes, including T cells and natural killer (NK) cells. Considerable effort has been invested in using IL-2 as a therapeutic agent for a variety of immune disorders ranging from AIDS to cancer. However, adverse effects have limited its use in the clinic. On activated T cells, IL-2 signals through a quaternary 'high affinity' receptor complex consisting of IL-2, IL-2Rα (termed CD25), IL-2Rβ and IL-2Rγ. Naive T cells express only a low density of IL-2Rβ and IL-2Rγ, and are therefore relatively insensitive to IL-2, but acquire sensitivity after CD25 expression, which captures the cytokine and presents it to IL-2Rβ and IL-2Rγ. Here, using in vitro evolution, we eliminated the functional requirement of IL-2 for CD25 expression by engineering an IL-2 'superkine' (also called super-2) with increased binding affinity for IL-2Rβ. Crystal structures of the IL-2 superkine in free and receptor-bound forms showed that the evolved mutations are principally in the core of the cytokine, and molecular dynamics simulations indicated that the evolved mutations stabilized IL-2, reducing the flexibility of a helix in the IL-2Rβ binding site, into an optimized receptor-binding conformation resembling that when bound to CD25. The evolved mutations in the IL-2 superkine recapitulated the functional role of CD25 by eliciting potent phosphorylation of STAT5 and vigorous proliferation of T cells irrespective of CD25 expression. Compared to IL-2, the IL-2 superkine induced superior expansion of cytotoxic T cells, leading to improved antitumour responses in vivo, and elicited proportionally less expansion of T regulatory cells and reduced pulmonary oedema. Collectively, we show that in vitro evolution has mimicked the functional role of CD25 in enhancing IL-2 potency and regulating target cell specificity, which has implications for immunotherapy.     

人体反应速度测试器的实验研究

对人体反应速度测试器实验教学设计与实践进行了探讨。提出了用中规模集成电路移位寄存器4015,或非门电路4001,施密特反相器40106和反相器4069构成的电路驱动8只发光二极管动态显示来实现一个实验电路的方法。实验电路包括了脉冲电路和数字逻辑电路,并要求学生在万用版上安装和焊接元器件,完成电路调试。通过对实验电路的搭接与实验结果的分析,强化了学生对数字电路应用的理解和动手能力的培养。     

一次写入式光盘用菁染料的研究

合成了一种ＣＤ－Ｒ用菁染料,测定了该染料溶液的吸收光谱,薄膜的吸收、透过和反射光谱。测定了用该染料制成的光盘在不同记录功率和记录频率下,不同记录速度的载噪比（ＣＮＲ）。结果表明,该染料能与相应ＣＤ－Ｒ刻录机的半导体激光器（７８０ｎｍ）很好地匹配,在合适的记录条件下,各种记录速度均有较好的载噪比。     

Differentiation potential of subsets of CD4-8- thymocytes

Precursor T cells in the thymus are contained within a subpopulation of thymocytes that lack the markers CD4 and CD8. We have examined the heterogeneity of these cells by flow cytometric analysis, and defined four subpopulations using the cell surface markers Thy-1, J11d and the IL-2 receptor (IL-2R). The J11d+ subset of CD4-8- cells all bear the antigen Thy-1, and some express the IL-2R. Staining and RNA analysis of J11d+ cells suggest that some express receptors of the CD3 gamma delta type, but none express CD3 alpha beta receptors. In fetal thymus organ culture, the J11d+ cells diversify to form 'cortical type' CD4+8+ cells and 'medullary type' cells expressing either CD4 or CD8; in vivo they repopulate the thymus of an irradiated host and seed the periphery with T cells. In contrast, the J11d- subset of CD4-8- thymocytes do not all bear Thy-1 and none express the IL-2R, but some express antigen receptors of the CD3 alpha beta type. They have more limited diversification potential in organ culture, and in vivo fail to recolonize the irradiated host in a homing-independent assay. We conclude that they are not precursor T cells, but rather a side-branch from the main line of T cell differentiation.     

丙肝患者PBMC mIL-2R及T细胞亚群检测

为了探讨丙型病毒性肝炎( 丙肝)患者膜白介素- 2 受体( mIL- 2R) 和 T 细胞亚群的表达水平及其在丙肝发病机理中的作用,用生物素- 链霉亲和素法对 203 例抗- HCV 阳性患者外周血单个核细胞进行 T 细胞亚群及植物血凝素( PHA) 诱导前后mIL- 2R 的检测. 总体结果显示丙肝患者外周血单个核细胞( PBMC) mIL- 2R 和 T 细胞亚群表达水平降低,与正常对照组相比,差异显著( P < 0. 01) .其中, 在静息状态和在 PHA 诱导状态,其 mIL- 2R 表达水平与正常对照组相比均低下( P < 0. 01) , 但急慢性丙肝患者中T 细胞亚群及 mIL- 2R 表达水平类似( P > 0. 05) . 急慢性丙肝患者与正常对照组相比,外周血 CD⁺₃ , CD⁺₄ 百分率降低, CD⁺₈ 百分率增高, CD⁺₄ / CD⁺₈ 比值下降( 从 P < 0. 05 降至 P< 0. 01) .说明丙肝患者体内存在明显的细胞免疫功能紊乱, T细胞活化障碍, 并与肝病的慢性化有关.