Calcium ionophore plus excision induce a large conductance chloride channel in membrane patches of human colon carcinoma cells HT-29cl.19A

In excised inside-out membrane patches of the human colon carcinoma HT-29cl.19A cells a large conductance (373±10 pS) chloride channel was found. Channel activity could only be observed after excision of patches from cells incubated with calcium ionophore. The channel was never observed in cell-attached patches. The channel was strongly voltage dependent, being open only between +30 and –30 mV clamp potentials. The selectivity sequence among anions, deduced from reversal potentials, was I>Br>Cl>F>gluconate. The P_Na/P_Cl was 0.09. Although a similar type of channel, has been described earlier, this is the first report stating its appearance in patches of intestinal epithelial cells requiring the combined action of Ca²⁺ ionophore and excision, suggesting its control by an intracellular compound.     

一种双码率90°旋转不变TCM－QAM方案

提出了一种适用于慢变信道的双码率ＴＣＭ－ＱＡＭ系统方案，该方案有较高的编码增益，同时满足９０°旋转不变要求．     

Interaction between bradykinin and voltage-sensitive sodium channels in myelinated nerve fibers

Summary The effects of externally and internally applied bradykinin on the excitability of single myelinated nerve fibers were studied. External bradykinin (10 M) slightly prolongs the action potential of a single myelinated nerve fiber; hence, when the fibers are stimulated by long-lasting pulses, this raises the frequency of repetitive firing in sensory fibers and evokes repetitive activity in motor fibers. Under voltage-clamp conditions, sodium channel inactivation is slowed, while sodium channel activation remains unaffected. Prolonged depolarization of th membrane leads to a maintained sodium current. The voltage dependence of the steady-state sodium current inactivation (h ) is shifted in the depolarized direction by 10 mV. Internally applied bradykinin produces a frequency-dependent block of the sodium current. The phenomena described here imply that more than one site on the sodium channel is modified by bradykinin.     

6.75kbit/s码激励线性预测编码器

提出用码激励线性预测（ＣＥＬＰ）实现ＧＳＭ半速率编码器的一种方案。该方案把中心削波和结构化码本相结合，并推导了加权滤波器响应的公式，使码本搜索的计算量大大降低，存储量显著减少，并获得高质量语音。计算机模拟结果表明，本方案编码速率为６７５ｋｂｉｔ／ｓ，合成语音ＭＯＳ得分为３５ｄＢ～４０ｄＢ。该方案可以在一块ＴＭＳ３２０Ｃ３０上实时实现。     

关于方块图演算方法的研究

本文给出了一种具有通用性的直接根据方块图结构，在不进行任何等效变换前提下列写系统（或环节）的传递函数的规则。     

表面声波在一维电子通道中诱导产生的声电电流

表面声波(SAW)在GaAS／AlxGa1-xAs异质结表面上沿由分裂门产生的准一维电子通道方向传播时，在通道中可诱导产生声电电流，根据准经典(WKB)近似，计算出一维电子通道钳断情况下的量子化声电电流，并详细讨论了源漏偏压和库仑相互作用对声电电流的影响。     

胰胆返流致胆道结石的实验研究

选用成年家犬通过手术建立胰胆返流致石模型。在人为胰胆返流七天后,伴有胆管完全梗阻的 A 组和部分梗阻的 B 组胆汁胆酸、卵磷脂、胆红素显著减少,胆固醇绝对值虽也减少,但相对比值却升高,胆汁沉淀压积增多,且肝外胆系有胆砂形成。单纯胰胆返流而无胆总管下端梗阻的 C 组,四种成分都减少,无胆砂,但有胆红素钙及胆固醇结晶沉淀。D 组(对照组)夹管仅造成胆管梗阻无姨胆返流,术后胆汁各成分按比例升高,胆管既无胆砂又无胆红素钙及胆固醇结晶。根据实验结果,作者认为胰胆返流特别是合并有胆总管下段完全性或不完全性梗阻是胆石症重要病因之一。据此建议采用手术方法中断胰胆返流,将有助于防止胆石形成和复发。     

柱镜板三维成像数学模型

根据三维像形成过程中人们视觉器官的生理特征、柱镜板的光学特性及双目标坐标建立起三维成像数学模型,并对这一模型进行了理论验证,为提高柱镜板三维成像质量提高了理论依据和途径。     

基于BCM降低OFDM系统PAPR的方法

简述了降低正交频分复用系统峰均功率比的研究进展,给出了基于分组编码调制降低峰均功率比的方法,提出了子载波数较大系统的搭建方法,分析了实现原理并进行了仿真研究,结果表明该方法不仅能有效降低正交频分复用系统的峰均功率比,而且具有前向纠错能力.