Anion modulation of taste responses in sodium-sensitive neurons of the hamster chorda tympani nerve

Beidler's work in the 1950s showed that anions can strongly influence gustatory responses to sodium salts. We have demonstrated "anion inhibition" in the hamster by showing that the chorda tympani nerve responds more strongly to NaCl than to Na acetate over a wide range of concentrations. Iontophoretic presentation of Cl- and acetate to the anterior tongue elicited no response in the chorda tympani, suggesting that these anions are not directly stimulatory. Drugs (0.01, 1.0, and 100 microM anthracene-9-carboxylate, diphenylamine-2-carboxylate, 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonate, and furosemide) that interfere with movements of Cl- across epithelial cells were ineffective in altering chorda tympani responses to 0.03 M of either NaCl or Na acetate. Anion inhibition related to movements of anions across epithelial membranes therefore seems unlikely. The chorda tympani contains a population of nerve fibers highly selective for Na+ (N fibers) and another population sensitive to Na+ as well as other salts and acids (H fibers). We found that N fibers respond similarly to NaCl and Na acetate, with spiking activity increasing with increasing stimulus concentration (0.01-1.0 M). H fibers, however, respond more strongly to NaCl than to Na acetate. Furthermore, H fibers increase spiking with increases in NaCl concentration, but generally decrease their responses to increasing concentrations of Na acetate. It appears that anion inhibition applies to taste cells innervated by H fibers but not by N fibers. Taste cells innervated by N fibers use an apical Na+ channel, whereas those innervated by H fibers may use a paracellularly mediated, basolateral site of excitation.     

Evaluation of two commercial kits for serum gastrin assay, and comparison with a conventional radioimmunoassay procedure

We compared two gastrin radioimmunoassay kits ("Immutope" kit, Squibb & Co.; "Gastrin R.I.A." kit, Schwarz/Mann) to the conventional gastrin radioimmunoassay of Yalow and Berson [Gastroenterology 58, 1 (1970)] as run by us and by a second reference laboratory. Although both kits were found to effectively discriminate above-normal and normal values for serum gastrin, they significantly underestimated very high values (greater than 1500 ng/liter). The Schwarz/Mann kit clearly had a superior quality label (lower nonspecific binding and higher specific activity) and a shorter incubation time. However, the 90-min incubation period cited for their kit caused overestimation of gastrin values in the lower range (5-300 ng/liter), which could be corrected by prolonging the incubation to 24 h. The Squibb antibody had fairly good cross reactivity to all gastrin species tested; the Schwarz/Mann antibody had poor affinity for natural human gastrin G34-II. Good correspondence was found for sera run by both reference laboratories (y = 0.96x + 10, r = 0.997), and values obtained with the Schwarz/Mann kit correlated best (+ 0.815) with those from the conventional radioimmunoassay procedure.     

~(123)I的制备及其快速标记

本文报道了在原子能研究所1.2米回旋加速器上用26MeV的α粒子流轰击天然丰度的锑靶,通过~(121)Sb(α,2n)~(123)I反应,以铜基铂吸附剂对碘选择性吸附法分离和浓集~(123)I,制得Na~(123)I溶液。Na~(123)I的放化纯度大于99％。在辐照结束时,其主要放射性杂质~(124)I占产品~(123)I的比率小于1.4％,整个分离过程不到4小时即可完成,总的化学收率在95％以上。所得产品用冠醚为溶剂,对肾上腺显影剂6-碘甲基-19-去甲胆固醇以及心脏显影剂ω-~(123)I-十七烷酸进行了快速标记。结果表明,与国内外现用的标记方法相比较,该法具有快速、简便、产额高等优点。     

基于有限障碍的全牛顿步内点算法

针对线性规划问题,文中引入了一种与传统障碍函数不同的新的障碍函数,其在可行域边界上的取值是有限的.沿此有限障碍函数所确定的新的搜索方向,给出了短步长全牛顿步内点算法,结果证明该算法具有目前求解线性规划问题最好的复杂性界.     

基于差分演化算法的软子空间聚类

软子空间聚类算法的性能主要取决于其目标函数和搜索策略.文中提出了一种基于差分演化算法的软子空间聚类算法DESC.首先,设计了一个结合模糊加权类内相似性和界约束权值矩阵的新目标函数.然后,提出了新的隶属度计算方法.最后,引入了一种有效的全局搜索算法——复合差分演化算法,并运用该算法优化新目标函数和搜索子空间中的聚类.实验表明,新目标函数和复合差分演化算法的引入有效地提高了软子空间聚类算法的性能,新算法较已有软子空间聚类算法有明显优势.     

一类有色噪声干扰下的随机时变系统学习辨识

讨论由一类时变ARMAX模型描述的动态系统学习辨识问题,提出用于估计有限区间上重复运行时变系统时变参数的学习算法.文中给出最小二乘学习算法的具体形式及实现步骤,并分析所提出学习算法的收敛性.分析结果表明,当重复持续激励条件成立且满足严格正实条件时,提出的学习算法具有重复一致性,即参数估值完全收敛于真值.文中还将结果推广到一类周期时变系统.通过数值仿真,进一步对所提学习算法的有效性进行了验证.     

不确定离散系统的神经网络自适应控制方法研究

本文研究了不确定离散系统的神经网络自适应控制器的设计。因为它不需要假设系统状态是可测的,一个观测器用来估计不可测状态。与现有离散系统的结果相比,该控制器具有较少的直接自适应参数。因此,可以很方便地实现工程算法。利用Lyapunov分析方法,所有的闭环系统的信号是保证最终有界（UUB）,并且能够实现系统输出跟踪参考信号到有界紧集。一个仿真例子,验证了该方法的有效性。     

The use of isoxsuprine in essential dysmenorrhea. A controlled clinical study

The "uterus-specific" beta-adrenoceptor stimulator isoxsuprine was used for the treatment of primary dysmenorrhea in a double-blind controlled clinical study. No significant beneficial effect of the drug was evident.     

Thermal explosion in a hot gas mixture with organic gel fuel droplets

Recent experimental evidence has uncovered the peculiar behavior of certain gel droplets which, under appropriate ambient thermal conditions, evaporate and burn in an oscillatory fashion. In this work a preliminary foray is made into the theoretical analysis of the nature of the evolution of a hot gas mixture containing organic gel fuel droplets with oscillatory evaporation within the context of thermal-explosion theory. The problem is modeled as a system of highly nonlinear singularly perturbed ordinary differential equations. Non-dimensionalization of the equations enables identification of the parameters that play a major role in determining the dynamical regimes of the system of equations. The method of integral manifolds is exploited for the analysis and it is found, that for certain parametric regions, the system exhibits new dynamical behavior that is quite different from that found for conventional liquid droplets.     

面向决策的一体化建模方法及其在兵力筹划中的应用

在对军事决策问题的主要特点进行分析的基础上，提出从军事概念模型到数学模型再到定性推理模型的一体化建模思想．以空军航空兵遂行直接航空火力支援任务为想定背景，根据EATI模板，利用基于UML的Rose工具依次对想定任务的实体、任务、交互等进行分析；对于兵力筹划中的结构化问题建立了机会约束多目标规划数学模型；对于非结构化问题则构造了推理机，推理机体现了定量与定性相结合的决策分析思想．最后，以一个实例验证文章思路的可行性．