Pharmacological determinants of the reinforcing effects of psychostimulants: Relation to agonist substitution treatment.

Illicit use of psychostimulants, such as cocaine and methamphetamine, continues to pose a significant public health concern. On the basis of the relative success at treating opiate and tobacco users with agonist substitution treatments, this strategy has been pursued in the search for a pharmacotherapy for psychostimulant addiction. The reinforcing effects of drugs are central to their abuse liability; therefore, gaining a better understanding of the factors that determine the reinforcing effects of psychostimulants should inform the development of an effective treatment. Although the reinforcing effects of drugs are known to be multiply determined, the author's dissertation research focused on pharmacological factors. This review presents results from that research as well as findings reported in the extant literature, suggesting that the reinforcing effects of psychostimulant drugs are determined both by their pharmacodynamic and pharmacokinetic profiles. There is evidence to support the conclusion that affinity for dopamine transporters appears to be of critical importance, whereas serotonin transporters seem to serve a modulatory function. A more rapid rate of onset may enhance a drug's reinforcing effects, but a drug with a slow onset can still maintain self-administration. A drug's duration of action may only influence the rate but not the strength of responding that is maintained. Slow-onset, long-acting monoamine transporter ligands can be expected to have reinforcing effects and therefore abuse liability, which has implications for the use of these drugs as pharmacotherapies. Nonetheless, on the basis of promising preclinical and clinical findings, this appears to represent a viable treatment strategy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

自行式振动压夯跳振压实的运动稳定性分析

通过对自行式振动滚压夯跳振压实的理论分析,推导出其系统运行的稳定性判断条件,为进一步完善设计,选取工作参数提供了理论依据。     

n-channel inversion-mode InP m.i.s.f.e.t.

Capacitance/voltage and m.i.s.f.e.t. inversion-mode f.e.t. data are reported for p-type InP. It is shown that the surface of this material appears to be inverted at zero gate bias and that good inversion-mode (normally-off) device behaviour is possible.     

Engineering Molybdenum-Assisted Tellurium Nanosonosensitizers for Enhanced Sonodynamic Tumor Nanotherapy

Materdicine-augmented sonodynamic therapy has emerged as an efficient noninvasive strategy for cancer treatment by generating reactive oxygen species associated with the cavitation effect and sonosensitizers. However, semiconductor-based inorganic nanosonosensitizers have undesirable nondegradability, which can cause unsatisfactory therapeutic efficacy and potential toxicity. With the aim of overcoming this obstacle, in this study, Mo-assisted Te (MT) nanosonosensitizers with high oxidative degradation abilities are engineered for photoacoustic imaging (PA)-guided sonodynamic tumor nanotherapy. Intriguingly, the engineered MT nanosonosensitizers can generate abundant singlet oxygen under ultrasound irradiation to eradicate tumor cells, thereby demonstrating its ability to achieve high tumor growth inhibition rates. In particular, MT nanosonosensitizers exhibit oxidative degradation properties that guarantee desirable biocompatibility and potentiate clinical translation. Therefore, this study validates a paradigm for theory-oriented design of sonodynamic tumor nanotherapy.     

The effect of surface states on the characteristics of MIS field effect transistors

A theoretical model, including the effect of surface trapping and velocity limiting, is developed for the MISFET and is compared with experimental data obtained on depletion mode GaAs anodic oxide devices. It is shown that the results are consistent with a model in which the surface states are inoperative at frequencies in excess of ～10² Hz while at lower frequencies the traps can follow the applied signal leading to a marked reduction in transconductance. The FET data are shown to be entirely consistent with the available C/V data on this semiconductor and suggest that at low frequencies near zero bias the surface potential varies by as little as 18 meV per volt of applied gate bias for the 100 nm of oxide typical of such structures.     

Novel 0D/1D ZnBi2O4/ZnO S-scheme photocatalyst for hydrogen production and BPA removal

Developing interfacial connections is one of the breakthrough strategies to improve the photocatalytic activity. Herein, ZnBi₂O₄ nanoparticles-ZnO nanorods heterojunction was successfully synthesized and used, as a dual-function photocatalyst, for photocatalytic degradation of Bisphenol A and hydrogen production with improved photocatalytic activity under simulated sunlight irradiation. The highest H₂ production (3.44 mmol g^?1 h^?1) was obtained for ZnO-20 wt% ZnBi₂O₄ sample, which is around 12.7 times higher than pure ZnO. According to the HRTEM result, the intimate interfacial connections are formed between ZnO and ZnBi₂O₄ which could act as trapping centers for charge carriers and results in the boosted photocatalytic activity. Further, a high aspect ratio of 1D ZnO nanorods and small size of 0D ZnBi₂O₄ nanoparticles (~10 nm) increases the number of interfacial contacts and thus the charge carriers’ recombination was suppressed more efficiently. Based on the trapping experiments, ESR and Mott-Schottky analysis, ZnBi₂O₄–ZnO hybrid photocatalyst followed the S-scheme charge transfer mechanism.     

乌井水库坝顶纵向裂缝变形监测与分析

设有混凝土防渗墙的土石坝出现坝顶纵向裂缝是常见的一种安全隐患,坝顶纵向裂缝的出现和扩展增加了大坝安全风险.本文在详细调查乌井水库纵向裂缝分布情况的基础上,经过一年运行周期的裂缝观测与变形观测,分析获得了纵向裂缝开度随库水位变化的扩展规律.进一步采用变形倾度法分析了大坝表面变形与坝顶纵向裂缝的相关性,结果表明:坝顶纵向裂...