超高温(200-250 ℃)聚合物电解质膜燃料电池的机遇与挑战

低温质子交换膜燃料电池的商业化受到高纯度氢气制取、储存、运输及加注的制约。将燃料电池工作温度提高到200-250 ℃可显著提高电极动力学,提高对一氧化碳等杂质气体的耐受性,降低氢气制取成本,简化水和热管理,为燃料电池提供更多燃料选择,使得高温质子交换膜燃料电池有望实现原位甲醇重整制氢系统与燃料电池系统的无温差耦合,同时较高的运行温度为直接甲醇燃料电池和非贵金属催化剂替代铂基催化剂提供了有利条件。但超高温（200-250 ℃）聚合物电解质膜燃料电池的发展依然面临着艰巨的挑战,为促进超高温聚合物电解质膜燃料电池的发展,本文将系统总结近年的相关进展,探讨超高温聚合物电解质膜燃料电池面临的机遇与挑战。     

宁波市医院内细菌流行分布的耐药性监测调查

目的：了解医院临床分离菌流行分布及抗生素耐药性。方法：采用20种抗菌药物纸片，琼脂扩散法监测医院临床分离菌的耐药性。结果：2732株细菌中1754株(64．2％)为革兰氏阴性菌，928株(35．8％)为革兰氏阳性菌，大肠埃希菌和克雷伯氏菌产ESBL，阳性率分别为43．2％、35．4％和46．8％葡萄球菌为甲氧西林耐药株，但对万古霉素均敏感，7．8％肠球菌对万古霉素耐药。大多数革兰阴性菌对氨苄西林耐药率60％，多数革兰阴性菌对头孢哌酮、头孢曲松、头孢噻肟耐药性明显，亚胺培南对大多数细菌有较大的抗菌作用。结果：近年医院临床分离菌耐药现象严重，需合理使用和控制滥用抗生素。     

医院感染的相关因素

１９９９年６月～２０００年６月全部住院患者共计８１１５例,按照中华医院管理学会制订的医院感染诊断标准统计．发生医院感染病例３７３例．医院感染发生率为４．６％．１．感染部位的分布 医院泌尿道感染占２６．９６％上呼吸道占２０．６５％,下呼吸道感染占１６．８８％,其它部位感染占１３．３５％,胃肠道感染占７、８１％,皮肤与软组织感染占６．８０％,手术切口感染占６．０５％,血液感染占１．５ｌ％．２．易感人群 脑血管疾病１６．３３％,肾炎肾病１０．５３％,糖尿病８．４２％,恶性肿瘤８．２８％,肝病及肝硬化４．…     

Crystal Structures and Physicochemical Properties of Solvated Estradiol

Polymorph screening is currently one of the most important tasks for innovators and for generic companies from both pharmaceutical and intellectual property rights aspects. The hemihydrate form(Form Ⅰ) and formamide solvate(Form Ⅱ) of estradiol are isolated and prepared via systemic crystallization screening in this paper, and the formamide solvate form is reported for the first time. Both polymorphic forms were characterized by single-crystal X-ray structure analysis(SXRD), powder X-ray diffraction(PXRD), and thermal analysis(TGA and DSC). The PXRD experiments indicate that the samples in this study are the pure polymorphic forms via comparing the patterns with the simulated ones. The stability and equilibrium solubility data of the solid-state phase were also examined in order to check the impact of the differences observed in their crystalline structures. It has been found that Forms I and II are of conformational polymorph and Form II is the more thermodynamically stable solid form, while Form I possesses higher solubility, indicating its possibility as an alternate solid form for its further solid formulation development if necessary.