经验与实验:近代英国对坏血病的认知和防治

坏血病是近代航海活动最为凶猛的敌人之一,曾夺去无数海员的生命。作为欧洲主要海洋国家之一,英国的海事力量也被坏血病大大折损,而不完善的军事体系和被削减的经费投入难辞其咎,使得坏血病可被部分理解为是一种"制度性"疾病。在技术上,尽管经历了一些歧路,以詹姆斯·林德为代表的18世纪英国医学界仍然在历史经验的基础上,通过实验的方式,最终确定了以食用柑橘属水果及果汁为防治坏血病的主要手段。虽然未能进一步揭示维生素C这一对抗坏血病的关键因子及其性质,但林德等人的努力和成就依然值得铭记。     

Enhanced urease inhibition activity of Ag nanomaterials capped with N-substituted methyl 5-acetamido-β-resorcylate

Medically, bacterial ureases are important virulent factors and are used for treatment of peptic ulcers and urinary tones. Reported urease inhibitors are associated with various side effects including antibiotic resistance as a major one. Still there is an urgent need to synthesize new urease inhibitors. In this context we have synthesized new urease inhibitor i.e. AgL that is composed of Ag nanomaterials capped with N-substituted methyl 5-acetamido-β-resorcylate(L). The conjugation of L to silver was confirmed through FTIR, UV–vis and TEM analysis.Bare silver nanomaterials(Ag) were also prepared. The stability of AgL nanostructures was determined against various parameters(temperature, high salt concentration, pH) and found to be stable. The in vitro antimicrobial(antibacterial, antifungal), enzyme inhibition(xanthine oxidase, urease, carbonic anhydrase, α-chymotrypsin,cholinesterase) and antioxidant activities of AgL were investigated and compared with Ag, L and standard drugs.In comparison to other bioactivities, AgL shows statistically enhanced selective enzyme inhibition activity against urease enzyme. Urease inhibition activity of AgL was significantly greater than standard drug(thiourea),L and Ag. On a per weight basis, AgL required about 11–18 times less amount of L for inhibition of urease enzyme.     

异丙苯裂解反应中Ti-ZSM-5分子筛的活性衰减与积炭

用异丙苯裂解反应考察了Ti-ZSM-5分子筛的催化活性,发现裂解活性与Ti-ZSM-5中Si/Ti有关,Ti进入分子筛骨架降低了积炭活性,但焦炭的生成并不影响稳态活性,表明炭主要沉积在催化剂的外表面上。     

钛铁矿制备的SO_4~（2－）／TiO_2型固体超强酸在酯化反应中的催化活性

以钛铁矿为原料制备了ＳＯ４２－／ＴｉＯ２固体超强酸型他化剂，结果表明其在乙酸和乙醇酯化反应中具有明显的催化活性。     

醌氢醌玻碳修饰电极的性能研究与应用

本文详细地研究了醌氢醌玻碳修饰电极的催化活性以及用该电极测定抗坏血酸的条件,测定结果非常理想。     

铬-铈氧化物的催化活性和掺碱(土)元素的影响

研究了Cr-Ce二元氧化物催化剂对甲苯完全氧化的性能,以及掺碱(±)金属元素对其活性的影响。实验表明Cr/Cr Ce(原子比)在0.5—0.7时,催化剂有最佳活性。碱(±)金属元素的掺加,改善了Cr-Ce体系对甲苯完全氧化反应的活性,并随掺入元素的碱性增大而提高。其中以钾的掺入效果最优,钾含量的增加,氧化活性随之提高,在K/Cr Ce(原子比)=0.05—0.10时最佳,再增大钾的含量,无益于催化剂活性的改善。     

The effects of temperature on ATPase activity and force generation in skinned muscle fibers from the Pacific blue marlin (Makaira nigricans)

Summary ATPase activity and force generation have been measured simultaneously in isolated, demembranated muscle fibers of the Pacific blue marlin (Makaira nigricans) between 0 and 30°C. Tension generation is relatively independent of temperature above 15°C and falls with a Q₁₀ of <1.5 on decreasing the temperature to 0°C. In contrast, the Q₁₀ for ATPase activity is 2.2 over the range 0–30°C. The results are interpreted in terms of the cross bridge theory of contraction.     

dr1127： A novel gene of Deinococcus radiodurans responsible for oxidative stress

The functional analysis of dr1127,a novel gene in Deinococcus radiodurans was performed in this pa-per. The dr1127 gene was found occasionally in our microarray and 2-DE gel experiments. Mutation of the dr1127 gene decreased the γ-radiation and H2O2 resistance of D. radiodurans,and weakened the scavenging abilities of cell extracts for free radicals (superoxide anion,hydrogen peroxide,and hy-droxyl radical). Further oxidative damage assays demonstrated that the purified DR1127 protein of D. radiodurans could bind to double stranded DNA in vitro and protect DNA from oxidative damage in this way. These results suggest that the dr1127 gene is an important gene that can maintain γ-radiation and oxidative resistance in D. radiodurans and may take part in the oxidative stress process.     

Both thermal and nociceptive afferents influence the unit activity of the neurons in the corpus striatum

Summary Both thermal and nociceptive stimulation in the periphery were shown to influence the neuronal activity recorded in the striatal area. Both the thermal and nociceptive sensitivity of the striatal neurons were closely related.The authors are grateful to the Alexander von Humboldt-Stiftung (Bad Godesberg, Bonn, Federal Republic of Germany) for donations of the necessary equipment for the present study. The research reported here was supported by grants from the National Science Council (Taipei, Taiwan, Republic of China)     

法莫替丁对鼠胃肠肌电活动的影响

观察１２只大鼠法莫替丁对体胃肠肌电活动的影响，结果发现：腹腔注射法莫替丁５ｍｉｎ左右胃窦肌电活动开始增强，４０ｍｉｎ慢皮和快波振幅明显增大；十二指肠电活动除快经有所提高外，漫波频率、慢波和快波振幅均未见明显改变。提示法莫替丁可兴奋胃窦肌电活动