Activity-dependent Decay of Early LTP Revealed by Dual EPSP Recording in Hippocampal Slices from Young Rats

The early maintenance of long-term potentiation (LTP) was studied in the CA1 region of hippocampal slices from 12- to 18-day-old rats in a low-magnesium solution (0.1 mM). The α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor-mediated components of the field excitatory postsynaptic potential were estimated in parallel using early and late measurements of the composite potential. At the normal test stimulus frequency of 0.1 Hz, LTP was seen initially as a predominant increase in the AMPA component, but converted, via a substantial decay of this component and a gradual growth of the NMDA component, into nearly equal changes of the two components. Interrupting the test stimulation for 10 min, changing the test stimulus frequency to 1/60 Hz after LTP induction, or using a test stimulus frequency of 1/60 Hz during the entire experiment significantly reduced the decay of the potentiation of the AMPA component while enhancing the potentiation of the NMDA one. The ratio between the magnitudes of the two excitatory postsynaptic potential (EPSP) components showed a decaying time course that was independent of the manipulations used. Application of the NMDA antagonist D(-)-2-amino-5-phosphonopentanoic acid (50μM) after LTP induction stabilized the LTP of the AMPA component until washout was started. On the other hand, the phosphatase inhibitor okadaic acid (1 μM) resulted in decay of the potentiation of both EPSP components back to around baseline and altered the time course of the ratio between the components. Our results show that the early maintenance of LTP is controlled in an activity-dependent and NMDA-dependent manner. This process accelerates the decay of LTP of both AMPA and NMDA components in parallel, suggesting that it is similar to homosynaptic long-term depression, although it operates at the normal test stimulus frequency. The data support a scenario in which LTP ensues as a selective AMPA receptor modification and subsequently converts to another modification, possibly a presynaptic one.     

系统性红斑狼疮的肺胸膜损害

分析了系统性红斑狼疮并肺、胸膜损害30例,胸膜改变占首位,共19例,(63.3％),其中胸膜积液16例,合并心包积液3例。其次为SLE肺炎5例(16.7％),尿毒症肺水肿3例(10％),弥漫性肺间质纤维化2例(6.7％),肺不张1例(3.35％)。对临床表现、诊断、治疗和预后进行了讨论。     

10例前置胎盘产后出血改良式宫腔纱布填塞临床分析

目的对改良式宫腔填塞治疗前置胎盘产后出血进行疗效分析。方法对我院手术室常规使用大尾纱行子宫下段胎盘附着面出血,填塞压迫止血进行回顾性分析。结果10例患者行子宫下段纱布填塞疗效明显,出血量400～600ml,均未输血,生命体征平稳,无产褥感染和晚期产后出血。结论子宫下段宫腔纱布填塞术治疗产后出血疗效显著。     

准分子激光屈光性角膜切削术治疗近视及近视散光临床分析

目的评价准分子激光屈光性角膜切削术治疗近视及近视散光的临床效果。方法应用准分子激光（NIDEKEC—5000型）治疗24D以下．伴或不件5D以内散光的近视眼。214只治疗眼随诊6个月以上。结果随诊1年以上的病例显示术后3个月屈光度及视力基本稳定。术后6个月时，在等值球镜度低于6D的治疗眼中，裸眼视力≥1．0者占92．04％，≥0．5为100％，80．53％的裸眼视力≥术前最佳矫正视力，99．12％的眼屈光度在预定矫正度数的±1．00D以内。低于10D的高度近视眼也有近似的疗效。214只治疗眼中操眼视力≥1．0者占78．97％，≥0．5为90．65％，72．43％的裸眼视力≥术前最佳矫正视力，88．32％的眼屈光度在预定矫正度数的±1．00D以内。6只眼（2．80％）最佳矫正视力减少2行以上，有Ⅱ级以上Haze的有7眼间（3．27％）。结论准分子激光屈光性角膜切削术治疗近视及近视散光具有很高程度的精确性和安全性，在＜10D的近视眼中更显示了良好的预测性和稳定性。     

多种底物在免疫金银染色检测抗核抗体试验中的联合应用

将多种底物联合应用于免疫金银染色检测ANA试验,与各底物单独应用比较,可明显改善检测的敏感性与核型显示。其中,两种鼠脏器印片联合应用的结果可与Hep-2细胞的结果相当,三种及四种鼠脏器印片联合应用的结果可与Hep-2细胞和一种鼠脏器印片联合应用的结果相当,且均不使正常人ANA阳性率明显升高。     

神经活素对Pc12细胞作用的初步观察

从胎脑、颌下腺、肌肉组织中制备神经活素。其性能同脑活素一样：可促进Ｐｃ１２细胞的突起生长，提高其胞浆内乳酸脱氢酶活性，电泳显示二者有相同的三条带。提示：神经活素有可能替代脑活素应用于临床。     

高血压病人药物治疗期间动态血压变化

目的评价高血压病人药物治疗期间２４ｈ动态血压变化。方法２６例住院的高血压病人经药物治疗４周连续３ｄ随测血压，血压正常后进入本研究。治疗前后进行２４ｈ动态血压监测。结果患者随测血压（８～９ＡＭ，３～４ＰＭ）血压恢复到正常水平，但动态血压显示在一段时间内（６～８ＡＭ，６～１１ＰＭ）平均收缩和舒张压仍明显高于正常人平均水平（Ｐ＜０．０１），而该时间段易被临床医生忽视。结论随测血压不能实际全面反映高血压病人药物治疗的疗效，２４ｈ动态血压的监测可以正确评价高血压病人药物治疗的效果并根据高血压分布的时间来调整降压药的种类和剂量。     

荧光分光光度法测定水产品中烷烃类、芳烃类污染物

目的：对使用荧光分光光度法测定水产品中烷烃类、芳烃类污染物的方法进行验证,并检测三类样品。方法：通过氢氧化钠-乙醇皂化处理,用正已烷萃取,用石油醚溶解,测量萃取物荧光强度值进行定量。结果：测得标准油在0.00～12.0μg/ml范围内线性关系良好,相关系数0.9999,检出限为0.2 mg/kg,平均回收率90.2%,RSD5.4%。结论：本法准确度、灵敏度高,检出限低,操作稳定性好。     

Global exponential stability of generalized recurrent neural networks with discrete and distributed delays.

This paper is concerned with analysis problem for the global exponential stability of a class of recurrent neural networks (RNNs) with mixed discrete and distributed delays. We first prove the existence and uniqueness of the equilibrium point under mild conditions, assuming neither differentiability nor strict monotonicity for the activation function. Then, by employing a new Lyapunov-Krasovskii functional, a linear matrix inequality (LMI) approach is developed to establish sufficient conditions for the RNNs to be globally exponentially stable. Therefore, the global exponential stability of the delayed RNNs can be easily checked by utilizing the numerically efficient Matlab LMI toolbox, and no tuning of parameters is required. A simulation example is exploited to show the usefulness of the derived LMI-based stability conditions.     

浅谈网络时代高校大学生思想政治教育工作

当前我们正经历着21世纪跨时空的信息革命，走进了网络信息的时代，网络比以往任何一次技术革命对社会的政治、经济、文化的冲击更强大，它塑造了一种全新的生活和工作状态。正是由于网络信息传播的影响而造成了人类的价值观和思维模式的变化，同时对当今大学生的思想也产生了较大的影响。那么，如何充分运用网络资源和信息技术传播社会主流价值形态和切实加强大学生思想政治教育成为社会关注的问题，也日益成为高校大学生思想政治教育工作者亟待研究和正在解决的重要课题。