杨凌示范区城市生活垃圾处理对策研究

杨凌示范区是全国惟一的国家级的农业高新技术产业示范区,其环境卫生的维护尤其重要。在对城市生活垃圾调查1a的基础上,利用层次分析法进行垃圾处理方案的优选,结果显示,堆肥＋填埋的处理方式符合杨凌的实际情况,是最优的处理方案。     

基于AHP方法研究广州地区15所三甲医院的规模评价模型

运用AHP方法对广州地区的15所三甲医院进行了分析,建立了医院综合指标规模评价的数学模型,给出了确定规模评价排序的方法。对15所医院构成的集合P与12个医院技术衡量指标构成的集合R组成的三甲医院组成规模评价模型进行了实证分析,结合2004年广东省卫生统计年鉴的数据给出医院集合P中所有医院规模评价的排序。     

区域基层卫生信息化评价指标体系的构建

目的：构建以卫生健康行政部门为评价主体的区域基层卫生信息化评价指标体系。方法：采用文献调研法、德尔菲专家咨询法和层次分析法等方法确定评价指标内容以及各项指标的权重。结果：建立区域基层卫生信息化评价指标体系,包含信息化的组织管理和规划、信息化保障体系、信息化基础设施建设、信息系统功能与应用、信息系统互联互通、信息系统的智能化情况、信息化建设成效7个一级指标、19个二级指标和51个三级指标的三阶层次结构模型以及指标权重。结论：指标体系构建过程科学,可以用于区域基层卫生信息发展水平的评价,为进一步开展信息化的评价奠定了良好的基础。     

基于离散Hopfield神经网络的本科毕业论文质量评价研究

针对当前高校本科毕业论文质量评价易受诸多人为因素影响而产生的不合理现象,本研究从论文选题、专业知识水平、资料收集能力、知识运用能力、指导教师水平和论文书写质量六个维度,构建了较为科学、客观的质量递阶层次评价模型。采用专家打分法,结合Matlab编程,应用层次分析法获得了毕业论文质量评价要素的权重,确定了影响毕业论文质量水平的关键要素;建立了毕业论文质量水平的离散Hopfield神经网络模型;抽取120份毕业论文进行质量水平仿真评价,并与理想的等级评价结果比较。研究表明,基于离散Hopfield神经网络的方法,可以有效对本科毕业论文质量提供客观、科学和规范的评价,具有广泛的应用价值。     

基于AHP-熵权TOPSIS法优选磁石炮制工艺及所含重金属元素的风险评估

目的 通过AHP优化的熵权TOPSIS模型对磁石的煅淬工艺进行优选,并对煅磁石饮片的重金属元素残留量进行健康风险评估。方法 通过正交试验,分别以Fe和Pb、As、Cd、Hg、Cu元素的含量为综合评价指标,采用《中国药典》2020年版规定的Fe含量测定法（重铬酸钾滴定法）和电感耦合等离子体质谱法（inductively coupled plasma-mass spectrometry,ICP-MS）进行含量测定,基于AHP-熵权TOPSIS法优选最佳炮制工艺参数。采用风险评估方法对煅磁石的重金属元素安全性进行评估,以磁石原粉入药为例,计算靶标危害系数（target hazard quotients,THQ）,并推算煅磁石中各重金属的最大残留限量理论值。结果 优化后的磁石煅淬工艺为煅烧时间90 min,煅烧温度650 ℃,煅淬2次。炮制后的煅磁石Fe含量变化不大,重金属元素含量降低,13批煅磁石饮片较原药材的健康风险显著降低（P＜0.05）。结论 初步制定煅磁石饮片中Pb、As、Cd、Hg、Cu的残留限量理论值依次为40、90、25、17、1 500 mg/kg;为磁石及同类矿物药的临床安全用药提供参考。     

Reduced after-hyperpolarization in rat piriform cortex pyramidal neurons is associated with increased learning capability during operant conditioning

Learning-related cellular modifications were studied in the rat piriform cortex. Water-deprived rats were divided to three groups: ‘trained’ rats were trained in a four-arm maze to discriminate positive cues in pairs of odours, ‘control’ rats were ‘pseudo-trained’ by random water rewarding, and ‘naive’ rats were water-deprived only. In one experimental paradigm, the trained group was exposed to extensive training with rats learning to discriminate between 35 and 50 pairs of odours. Piriform cortex pyramidal neurons from ‘trained’, ‘control’ and ‘naive’ rats did not differ in their passive membrane properties and single spike characteristics. However, the after-hyperpolarizations (AHPs) that follow six-spike trains were reduced after ‘extensive training’ by 43% and 36% compared with ‘control’ and ‘naive’, respectively. This effect was not observed in the piriform cortex of another group of rats, in which hyperexcitability was induced by chemical kindling. In another experimental paradigm rats were trained only until they demonstrated ‘rule learning’, usually after discriminating between one and two pairs of odours (‘mild training’). In this experiment, a smaller, yet significant, reduction (20%) in AHPs was observed. AHP reduction was apparent in most of the sampled neurons. AHP remained reduced up to 3 days after the last training session. 5 days or more after the last training session, AHP amplitude recovered to pre-training value and did not differ between ‘trained’ rats and the others. Accordingly, training suspension for 5 days or more resulted in slower learning of novel odours. We suggest that increased neuronal excitability, manifested as reduced AHP, is related to the ability of the cortical network to enter a ‘learning mode’ which creates favourable conditions for enhanced learning capability.     

Excitatory amino acid-induced responses of frog motoneurones bathed in low Na+ media: an intracellular study

Motoneurones of the frog spinal cord slice preparation were impaled with microelectrodes and superfused at 7 degrees C with the excitatory amino acids glutamate, quisqualate or N-methyl-D-aspartate. The role of Na+ in the action of these amino acids was studied by comparing amplitude matched depolarizations obtained in control Ringer solution with the responses recorded from the same cells after replacing (86-100%) Na+ by choline or glucosamine. Effective replacement of extracellular Na+ proved to be a rather slow process requiring 30-60 min. In glucosamine solution depolarizations evoked by glutamate, N-methyl-D-aspartate or quisqualate were abolished or strongly reduced with recovery following return to control Ringer. In choline solution, glutamate and N-methyl-D-aspartate effects were blocked whereas the quisqualate response was surprisingly unaffected. Mn2+ (2 mM) added to choline solution strongly diminished the action of quisqualate. These results suggest that Na+ was important in mediating amino acid responses and that quisqualate activated an additional conductance mechanism (perhaps to Ca2+) unmasked only in choline-containing solution.     

用AHP法建立评价地区性孕产妇系统保健管理模式的探讨

根据妇幼保健管理的性质、特点,制定一套定性、定量的目标－指标体系,并辅以一套科学的评价方法,是使妇幼保健工作逐步由经验型向科学型过渡的必要手段。作者在文章中引进了运筹学中的ＡＨＰ法,并依该法建立了孕产妇系统保健质量评价模式,为各级妇幼保健及卫生行政机构提供了一个考核、评价本地区孕产妇保健工作质量的科学方法。     

Dopamine modulates CA1 hippocampal neurons by elevating the threshold for spike generation: an in vitro study

Intracellular recordings were obtained from CA1 neurons of rat hippocampal slices preparation. Dopamine applied by perfusion (10(-5)-10(-7) M), microdrop (10(-4) M) and iontophoresis (+80, +200 nA balanced current) inhibited "spontaneous" and evoked action potentials. An increase in current injection restored the evoked action potentials which appeared unmodified. Membrane potential was not modified in 60% of the neurons; in the remaining ones, a slow depolarization was observed. Membrane resistance, measured at rest, was not modified by dopamine. Calcium-mediated events such as bursting activity and afterhyperpolarization, mainly in the late component, were also attenuated by the catecholamine. These effects were antagonized by domperidone, a dopaminergic antagonist. Calcium spikes, evoked in tetrodotoxin- and tetraethylammonium-poisoned slices, were reversibly inhibited by dopamine. Since an increase in the amplitude of a depolarizing pulse of injected current was able to evoke both sodium and calcium action potentials suppressed by dopamine without change in shape or duration, it is concluded that this catecholamine depresses cellular excitability by altering the interaction between membrane voltage and sodium and calcium entry and the subsequent increase in potassium conductance.     

Ionic currents and firing patterns of mammalian vagal motoneurons in vitro

The electrophysiological properties of guinea-pig dorsal vagal motoneurons were studied in an in vitro slice preparation. Antidromic, orthodromic and direct stimulation of the neurons demonstrated that the action potential is comprised of several distinct components: a fast initial spike followed by afterdepolarization and an early and a late afterhyperpolarizations. The fast initial spike and the early afterhyperpolarization were blocked by tetrodotoxin and tetraethylammonium ions, respectively. The afterdepolarization (present on the falling phase of the spike) and the late afterhyperpolarization were blocked by the addition of ions known to block calcium conductance (CdCl2, CoCl2 or MnCl2), indicating close association between these two potentials. Prolonged outward current injection through the recording electrode produced two different firing patterns, depending on the initial level of the membrane potential. From resting potential (usually -60 mV) the firing pattern was characterized by a short train of action potentials appearing shortly after the onset of the depolarization step. By contrast, when the depolarization was delivered from a hyperpolarized membrane potential level, a short train of repetitive firing appeared after an initial delay of 300-400 ms. The membrane current responsible for this initial reduction in excitability was studied by means of a single-electrode voltage-clamp technique. The magnitude, direction and kinetics of such current flow are consistent with the presence of early potassium current (IA), partly inactive at the resting potential. Synaptic activation of vagal motoneurons could be obtained by electrical stimulation of the tissue surrounding the vagal nucleus or by direct activation of the vagal nerve. Perivagal stimulation generated excitatory and inhibitory synaptic potentials which could be reversed by shifting the membrane potential. Vagal nerve stimulation, in addition to the antidromic activation of the cells, generated depolarizing responses which were unitary in nature and did not show much sensitivity to shifts in membrane potential. Perivagal and vagal nerve-evoked depolarizations could generate action potentials as well as partial dendritic spikes. We conclude that spike electroresponsiveness in vagal motoneurons is generated by voltage-dependent Na+ and Ca2+ conductances. In addition, the Ca2+-dependent current triggers a K+ conductance which is responsible for modulating the firing frequency obtained from the normal resting level.(ABSTRACT TRUNCATED AT 400 WORDS)