水样品放射性核素γ能谱分析的比对与评价

目的 通过在重点实验室间开展γ能谱测量分析比对活动,改进水样品的γ能谱分析技术。方法 参加中国计量科学研究院组织的水样品中γ能谱测量分析比对。样品中²³⁸U、 ²²⁶Ra、²⁰⁸Tl、²²⁸Ac、⁴⁰K、²⁴¹Am、¹³⁷Cs、⁶⁰Co被检出。为分析比对结果,2015年又采用新制备的水标准源重新进行了效率刻度,并且采用了1台新购进的γ能谱仪（BE5030）重新测量了比对样品。结果 比对样品3次测量结果与主导实验室参考值的分析比较,发现采用γ能谱仪（BE5030）测量分析的结果较好,特别是天然核素结果,与参考值的最大E_n值仅为0.71。结论 宽能高纯锗γ能谱仪（BE5030）在天然放射性核素的测量分析方面优势明显,并且由于其探测器的结构特点,使得其在低能区本底干扰更少。此次比对改进了本实验室样品测量分析的准确性,取得了良好的效果。     

Correction to: Gyral-sulcal contrast in intrinsic functional brain networks across task performances

Brain Imaging and Behavior - A Correction to this paper has been published: https://doi.org/10.1007/s11682-020-00426-z     

氟西汀联合地西泮对ICU急性心肌梗死患者焦虑抑郁情绪及睡眠质量的影响

目的 探讨盐酸氟西汀联合地西泮对重症监护病房（ICU）急性心肌梗死患者焦虑抑郁情绪及睡眠质量的影响。方法 选取我院2018年2月～2020年2月期间105例ICU急性心肌梗死患者作为研究对象,采用抽签法分为地西泮组和氟西汀组。地西泮组52例给予地西泮口服治疗,氟西汀组53例在地西泮组基础上给予盐酸氟西汀口服治疗。治疗1个月,对比两组患者焦虑抑郁情绪、内皮功能、睡眠质量及不良反应。结果 两组治疗1月末汉密尔顿焦虑量表（HAMA）、汉密尔顿抑郁量表（HAMD）评分较治疗前均降低,且氟西汀组低于地西泮组（P<0.05）。两组治疗1月末内皮素-1(ET-1)水平较治疗前均降低,且氟西汀组低于地西泮组;一氧化氮（NO）水平较治疗前均升高,且氟西汀组高于地西泮组（P<0.05）。两组治疗1月末匹兹堡睡眠质量指数（PSQI）评分较治疗前均降低,且氟西汀组低于地西泮组;氟西汀组入睡时间、安眠药品使用频次水平低于地西泮组,睡眠时间水平高于地西泮组（P<0.05）。氟西汀组不良反应发生率7.55%(4/53)和地西泮组3.85%(2/52),无明显差异（P>0.05）。结论 盐酸氟...     

幼鼠癫痫模型海马神经元NMDA受体表达与MMP-3表达相关性

目的 探讨幼鼠癫痫模型海马神经元N-甲基-D-天冬氨酸受体（NMDAR）表达与基质金属蛋白酶-3（MMP-3）表达的相关性。方法 将60只2~4周龄SPF级C57/BL6小鼠随机分为正常组、癫痫组、MMP-3抑制剂组、NMDAR抑制剂组,每组15只。采用匹罗卡品建立幼鼠癫痫模型;采用RT-PCR检测海马神经元NMDAR2A、NMDAR2B、MMP-3 mRNA表达;采用尼氏染色观察海马区神经元形态;采用Western blot检测海马区P-糖蛋白（P-gp）、钙调蛋白激酶Ⅱ（CAMKⅡ）蛋白表达。结果 幼鼠癫痫模型海马区NMDAR2A/B、MMP-3 mRNA以及P-gp、CAMKⅡ蛋白较正常组显著增加（P<0.05）。注射NMDA受体抑制剂或MMP-3抑制剂可显著降低幼鼠癫痫模型NMDAR2A/B、MMP-3 mRNA及P-gp、CAMKⅡ蛋白表达,且明显改善海马区神经元结构。结论 幼鼠癫痫模型海马神经元MMP-3表达与MNDAR表达可能具有相关性。     

Predicting RNA secondary structure based on the class information and Hopfield network

One of the models for RNA secondary structure prediction is to view it as maximum independent set problem, which can be approximately solved by Hopfield network. However, when predicting native molecules, the model is not always accurate and the heuristic method of Hopfield network is not always stable. It is because that the class information is lost and the accuracy is not determined by the number of base pairs only. Secondary structures of non-coding RNAs are believed conservative on the same class. However, software and web servers nowadays for RNA secondary structure prediction do not consider the class information. In this paper, we involve class information in the initialization of Hopfield network. When the initialization is improved, the promising experimental result shows the efficacy and superiority of our proposed methods.     

Laminar-flow immediate-overlay hepatocyte sandwich perfusion system for drug hepatotoxicity testing

Drug hepatotoxicity testing requires in vitro hepatocyte culture to maintain the long-term and stable liver specific functions. We developed a drug testing platform based on laminar-flow immediate-overlay hepatocyte sandwich perfusion culture. The immediate-overlay sandwich (collagen-coated porous polymeric membrane as top overlay) protects the cells and integrity of the top collagen matrix from the impact of flow. A bioreactor was designed that allowed proper control of shear stress and mass transfer. The culture parameters such as the optimal perfusion initiation time and flow rate were systematically and mechanistically determined. The optimized system could re-establish hepatocyte polarity to support biliary excretion and to maintain other liver specific functions, such as the biotransformation enzyme activities, for two weeks that extended the usable in vitro hepatocyte-based drug testing window. When the perfusion cultured hepatocytes from days 7 or 14 were used for drug testing, the APAP-induced hepatotoxicity measurements were more sensitive and consistent over time than the static culture control, enabling further exploitations in large-scale drug testing applications.     

急性脑梗死后继发不安腿综合征20例分析及文献复习

目的 总结急性脑梗死后继发不安腿综合征(RLS)的临床、影像学特征.方法 回顾性分析2012年1月至2019年1月北京友谊医院诊治的20例急性脑梗死后继发RLS患者的临床表现、头颅磁共振(MRI)影像及治疗方案,总结其临床特征.结果 20例急性脑梗死后继发RLS患者的年龄为(62.65±9.40)岁;其中男性12例,女...     

Persephin在顺铂诱导的急性肾损伤小鼠中的作用初探*

目的：观察顺铂诱导急性肾损伤（acute kidney injury,AKI）模型中肾皮质Persephin（PSP）的变化。方法：雄性C57BL/6小鼠随机分为对照组及模型组,模型组应用顺铂单次腹腔注射（15mg/kg）制备AKI小鼠模型,对照组小鼠予以同等容积的0.9%的生理盐水单次腹腔注射,造模3天后观察各组小鼠肾功能变化、肾脏病理学改变、实时PCR法及Western印记法检测肾脏皮质PSP的表达。结果：与对照组相比,模型组小鼠出现精神萎靡不振,反应迟钝,活动减少,造模后第3天尿素氮明显上升（P＜0.05）,肾脏病理改变中模型组肾小管管型计数（0.63±0.62个/HPF）及坏死计数（3.71±1.14个/HPF）均高于正常对照组（P＜0.05）。PSP在模型组肾皮质的表达高于对照组（P＜0.05）。结论：AKI模型中肾脏皮质PSP表达升高,提示PSP可能参与了AKI的病程,但其相关作用机制尚需进一步研究。