高等级公路水泥混凝土路面滑模摊铺施工技术探讨

高等级公路水泥混凝土路面采用滑模施工技术,具有施工机械化程度高、规模大、速度快的特点。本文结合工程实例,对水泥混凝土路面滑模摊铺施工过程中原材料控制和配合比设计进行详细阐述,在此基础上,对水泥混凝土路面滑模摊铺施工技术要点进行了深入探讨和总结。     

Effects of acetylcholine and glutamate on isolated neurons of locomotory network of Clione

In Clione limacina, locomotory rhythm is produced in the central pattern generator by reciprocal activity of two groups of interneurons. Dorsal (D) and ventral (V) phase interneurons activate neurons of the same phase and inhibit neurons of the opposite phase. Which neurotransmitters are used by these interneurons is not clear. In this study, identified follower neurons to V and D interneurons were isolated, and their responses to the local application of potential neurotransmitters were examined. Acetylcholine exerted inhibitory action on the isolated D-phase neurons and excitatory action on V-phase neurons. Glutamate produced excitation in D-phase neurons, and inhibition in V-phase neurons. These results suggest that acetylcholine is the neurotransmitter of D-phase interneurons, while glutamate might be the neurotransmitter of V-phase interneurons.     

Dynamics of clot growth induced by thrombin diffusing into nonstirred citrate human plasma

We have tested whether action potential-evoked Ca2+ influx is required to initiate clathrin-mediated synaptic vesicle endocytosis in the lamprey reticulospinal synapse. Exo- and endocytosis were temporally separated by a procedure involving tonic action potential stimulation and subsequent removal of extracellular Ca2+ (Ca2+e). A low concentration of Ca2+ ([Ca2+]e of 11 microM) was found to be required for the induction of early stages of endocytosis. However, the entire endocytic process, from the formation of clathrin-coated membrane invaginations to the generation of synaptic vesicles, proceeded in the absence of action potential-mediated Ca2+ entry. Our results indicate that the membrane of synaptic vesicles newly incorporated in the plasma membrane is a sufficient trigger of clathrin-mediated synaptic vesicle endocytosis.     

Screening for high-affinity ligands to the Src SH2 domain using capillary isoelectric focusing-electrospray ionization ion trap mass spectrometry

A solution-based microscale approach for determination of high-affinity noncovalent complexes from mixtures of compounds is presented, based on capillary isoelectric focusing coupled on-line with electrospray ionization ion trap mass spectrometry. The studies are performed using the src homology 2 domain and tyrosine-phosphorylated peptide ligands as a model system. Tight complexes are formed in solution, preconcentrated up to 2 orders of magnitude and separated on the basis of their isoelectric points. The complexes are then dissociated in the mass spectrometer and the freed ligands identified. Picomole or less amounts of protein reagent are consumed per experiment. Structural information for the ligands involved in tight complex formation may be obtained using the MSn capabilities of the ion trap. The methodology can potentially be used to screen rapidly combinatorial mixtures of compounds for high-affinity ligands.     

Synthesis of phosphoramide mustard analogues of daunomycin and carminomycin

New phosphoramide mustards (6-8) have been prepared from the antibiotics 2 and 3, and from 5. The mixture of cyclophosphamides could be separated by preparative layer and column chromatography. The assignments of configuration to the isomeric phosphoramidates was based on the magnetic anisotropy of the P = O bond. The synthesized compounds 6a,b-8a,b (mixture of isomers) were tested for inhibitory activity on the [3H]-thymidine incorporation into the DNA of tumor cells, using ovarian carcinoma cell line.     

Postresuscitation changes in brain free radical-mediated processes and nitric oxide synthase activity in rats: effects of individual behavior in "emotional resonance" test

Effects of 7-min cardiac arrest and individual behavior on free radical-mediated processes and nitric oxide synthase (NOS) activity was evaluated in brains of male Wistar rats one hour and one week after resuscitation. "Emotional resonance" test was used for the behavioral selection of rats. The test includes factors of significance for rats: the choice between large and lighted or small and dark space as well as signals of pain of another rat. Free radical generation (using chemiluminescence method), superoxide scavenging/generating activity, substances reacting with 2-thiobarbituric acid and NOS activity (by measuring mononitrosyl iron complex of NO with diethyl dithiocarbamate and endogenous brain Fe2+ by electron spin resonance spectroscopy) were determined in cerebral cortex, cerebellum and hippocampus. Cardiac arrest induced oxidative stress accompanied by the loss of NOS activity, as well as compensatory changes of free radical-mediated processes in cerebral cortex. Oxidative stress was also evident in cerebellum and, to a lesser extent, in hippocampus. Most of neurochemical differences between behavioral groups were induced by cardiac arrest. These differences were global, related to a specific brain region or became apparent in cerebral lateralization of biochemical indices.     

Impact of dynamic 3D transoesophageal echocardiography in the assessment of atrial septal defects and occlusion by the double-umbrella device (CardioSEAL)

Previous research has supported theoretical claims that dichotomous thinking may be a risk factor for suicide. However, the concept of dichotomous thinking is vague, and thus far, no measures of it have been developed. This study developed a coding scheme useful on Thematic Aperception Test (TAT; Murray, 1943) protocols and applicable to other verbal productions to refine the concept of dichotomous thinking and to assess its utility as a predictor of suicidality. Suicidal patients had a significantly elevated rate of a narrowly defined type of dichotomous thinking involving diametric or polarized possibilities. However, suicidal and nonsuicidal patients did not differ on weaker forms of dichotomous thinking involving nonexclusive or nonbinary alternatives. Suicidal patients produced shorter TAT stories than nonsuicidal patients, supporting other findings in the literature that suicidal patients tend to be cognitively and affectively "shut down." Traditionally designated "suicide cards" also yielded shorter stories but did not elicit higher rates of dichotomous thinking.     

聚亚苯基砜的合成与表征

以环丁砜为溶剂,用4,4'-二氯二苯砜和4,4'-联苯二酚为单体,无水碳酸钾为成盐剂,甲苯为脱水剂,采用"成盐"和"缩聚"两步反应合成出了我国长期依赖进口的特种工程塑料聚亚苯基砜(PPSU),并对产物进行了纯化。对比分析和测试了自制样品和美国Solvay公司产的PPSU样品的比浓对数黏度,C、H和K元素含量,核磁共振氢谱,傅里叶变换红外光谱,激光拉曼光谱,玻璃化转变温度和热分解温度。结果表明它们具有相同的化学结构、相近的分子量和纯度,自制PPSU的玻璃化转变温度比Solvay公司产的高约5℃,热稳定性相差不大。