The early phase of experimental acute renal failure

Experiments were conducted to establish whether diminished solute reabsorption in the loop of Henle during acute renal failure could explain the loss of urinary concentration and participate in generating a tubuloglomerular feedback-mediated reduction in filtration rate. The electrolyte content of the fluid in the ascending limb of the loop of Henle was determined in situ by monitoring its electrical conductivity after propulsion into the distal tubule with a sudden burst perfusion. The value of the minimum electrolyte concentration decreased exponentially with increasing equilibration time, reaching a steady-state value equivalent to 27±9 mM NaCl in normal kidneys, 34±15 mM in mercuric chloride kidneys and 53±22 mM following ischaemia. A mathematical model was derived to describe the process of sodium chloride dilution from which it was possible to calculate both the permeability and transport velocity of the cortical thick ascending limb. In the normal kidney, the transport velocity was calculated to be 4.65±0.92 ·10^–5 cm/s, a value not significantly different from that of the mercuric chloride or ischaemic kidneys, and the estimated permeability was 1.13±0.52·10^–5 cm/s, not different from that of the mercuric chloride kidneys but significantly lower than that calculated for the ischaemic kidneys. It is concluded that for the more severely damaged ischaemic model, the loss of urinary concentrating ability was accompanied by a reduction in diluting ability of the ascending limb of the short loop of Henle, which appears to be due, at least in part, to an elevation of the passive permeability to sodium chloride in this segment.     

人格特征与防御方式的相关研究

目的 :尝试用防御机制解释EPQ各维度的特征。方法 :采用EPQ人格问卷、DSQ防御方式问卷、16PF中的G量表对 2 2 0例成人进行测试。结果 :本样本中EPQ各维度与成熟防御方式均无显著相关 (P >0 .0 5 ) ,N维度和P维度均与不成熟防御方式、中间型防御方式有显著正相关 (P <0 .0 0 1)。结论 :本研究显示 ,可以用防御机制解释EPQ各维度的某些特征。     

齿龈内阿米巴的致病作用与致病机制的研究

在注射免疫抑制剂 1周后的大白鼠龈缘涂抹齿龈内阿米巴 (Emtamoebagingivalis ,E .g .) ,5天后 ,牙龈组织出现溃疡、牙周脓肿形成、脓液查见活E .g .、牙槽骨吸收等牙周炎病症。电镜术与生化分析发现 :E .g .伪足活跃、有丰富的溶酶体 ,所含水解酶与ACP显著较健康组高 (P <0 0 1) ,可使牙周组织溶解与受损。SOD较健康组显著性低 (P <0 0 1) ,MDA显著性增高 (P <0 0 1) ,说明E .g .感染产生较多氧自由基可使细胞膜受损 ,加上口腔共生菌的协同作用使免疫力低下的宿主发生牙周炎。     

Effects of ultrasound,the polyene antibiotic amphotericin B,and their combination on biomembranes of yeastlikeCandida fungi

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 10, pp. 391–393, October, 1993     

Improvement of cognitive function by blood flow restriction training: mechanisms and applications北大核心

BACKGROUND: Blood flow restriction training is a new resistance training. Blood flow restriction training can not only influence muscle strength, mass and physical ability, but also induce and activate related signaling pathways such as neural plasticity and cognitive function. However, current studies have not systematically evaluated the effects of blood flow restriction training on the cognitive ability of different populations, and the neurobiological mechanism by which blood flow restriction training improves cognitive function is not fully understood. Moreover, the application solutions of blood flow restriction training are still not fully understood. OBJECTIVE: To review the existing experimental studies on the influence of blood flow restriction training on cognitive function of different populations, deeply analyze the potential neurobiological mechanisms, and summarize the previous rational programs of blood flow restriction training that improve cognitive function, in order to provide theoretical support and practical guidance for the safe and effective application of this technology. METHODS: PubMed, Web of Science, and CNKI databases were retrieved using “blood flow restriction training, pressure training, blood flow restriction therapy, blood flow restriction, pressure blood block training, blood block, cognitive function, cognitive ability” as Chinese keywords and “blood flow restriction therapy, KAATSU training, KAATSU volume, resistance training, BFR therapy, BFRT, blood flow restriction exercise, cognition, cognitive function” as English keywords. The search deadline was October 2022. Relevant inclusion criteria were established according to the research needs and finally 84 articles were included for further review. RESULTS AND CONCLUSION: The experimental studies regarding the influence of blood flow restriction training on cognitive ability mainly select healthy people as subjects in an attempt to explore its application value in healthy elderly populations. However, in general, there are few studies on elderly people and patients with cognitive dysfunction. Blood flow restriction training can be used as a key factor to trigger positive neural adaptation to a certain extent by applying hypoxic stimulation to the extremity to induce transient brain oxygen deficiency. Blood flow restriction training can significantly improve the levels of bioactive molecules related to the improvement of cognitive function, mainly including insulin-like growth factor 1, growth hormone, vascular endothelial growth factor, brain-derived neurotrophic factor, lactic acid, hypoxia-inducible factor 1α, peroxisome proliferator-activated receptor-γ coactivation factor 1α and norepinephrine. The formulation of blood flow restriction training application programs involves the selection of training participants, the determination of exercise factors and the setting of cuff pressure and its width. Future studies should pay attention to the comparison of the application effects of different blood flow restriction training methods in different populations, so as to make the clinical application of blood flow restriction training more perfect and reasonable, providing more theoretical basis for blood flow restriction training to improve cognitive function in patients with cognitive dysfunction. © 2023, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Involvement of a Na−Ca exchange mechanism in contraction induced by low-Na solution in isolated guinea-pig aorta

The possibility of involvement of a Na–Ca exchange mechanism in the contractile responses induced by a reduction of external Na concentration ([Na]₀) has been studied in isolated guinea-pig aorta. Low-Na (11.9 mM) solution (Lisubstituted) produced a contraction in ouabain-treated muscles in the presence of phentolamine (10^–6 M). The magnitude of the contraction was dependent on the duration of the pretreatment with ouabain (2×10^–5 M). Ca-free solution, but not verapamil (10^–6 M), abolished the contraction induced by low-Na solution. The muscles were loaded with various amounts of Na by incubating the tissue with ouabain and varying [Na]₀ (11.9–148.7 mM) in the absence of Ca. The magnitude of the contractions induced in these muscles by low-Na solution containing Ca (2.5 mM) was dependent on the cellular Na content. Loss of cellular Na into low-Na solution followed a single exponential time course and the rate coefficient of Na-loss in the presence of external Ca was about twice as great as in the absence of Ca. Cellular⁴⁵Ca uptake in low-Na solution was significantly greater in Na-loaded tissues (pretreated with ouabain for 3 h) than in normal tissues. The⁴⁵Ca uptake in low-Na solution was not inhibited by verapamil. These results suggest that the contraction induced by low-Na solution is caused by a Ca influx which is dependent on internal Na (a Na–Ca exchange mechanism).     

TNF inhibits malaria hepatic stages in vitro via synthesis of IL-6

We examined the capacity of murine recombinant tumor necrosis factor (rmTNF) to induce an inhibitory effect at the hepatic stage on malaria induced by Plasmodium yoelii sporozoites. When injected three times, 1.0 micrograms of rmTNF was found to protect 78% of mice against a sporozoite challenge. In contrast, whatever the dose and the schedule of administration, no inhibition was observed when purified hepatocyte cultures were infected with P. yoelii. The addition of non-parenchymal hepatic cells to hepatocyte cultures restored the capacity of TNF to modulate hepatic stage development, leading to up to 44% inhibition. Antibodies to interleukin 6 reversed the anti-parasite activity in the co-culture system.     

公共卫生本科生实践能力培养长效机制的模型探索

目的 探索和构建公共卫生本科生实践能力培养长效机制的模型。方法 查阅文献、问卷调查和访谈以构建模型,通过对照组和干预组统计学分析和开展问卷满意度调查来分析模型的可行性,数据分析采用t检验、秩和检验,统计分析使用Stata 14软件。结果 干预组和对照组实践能力总计分数差异有统计学意义(t = 2.660,P = 0.002),综合实践能力分数差异有统计学意义（t = 6.656,P＜0.001）。学生满意度,就业机构或升学学校满意度分析均提示模型能够提升学生的实践能力。结论 模型具有可行性,为进一步提升公共卫生本科生实践能力提供了方法实践。     

国际典型综合类科技期刊公众传播特点及对我国综合类科技期刊公众传播能力建设的启示

【目的】 分析国际顶级综合类科技期刊公众传播模式及特点,为我国科技期刊公众传播能力建设提供建议。【方法】 以Altmetric Top 100入选论文数量最多的Nature、Science和PNAS三刊为研究对象,剖析其在公众传播产品、媒体传播体系和新闻媒体人才支撑等方面的模式和特征。对照分析我国最有影响力的综合类科技期刊《国家科学评论》和《科学通报》的公众传播特点。【结果】 以《国家科学评论》和《科学通报》为代表的我国综合类科技期刊的公众传播能力提升迅速,但仍存在新闻传媒人才短缺、期刊集约化程度不高、公众传播机制尚未建立等问题。【结论】 我国综合类科技期刊需要着力增强传媒人才培育、集约化品牌发展、公众传播机制建设,以促进我国科技期刊公众传播能力提升。     

我国科技学术期刊编委会运行机制优化指标体系构建

【目的】 提出期刊出版界、科技界和期刊评价方普遍认同的编委会运行机制优化指标体系,为期刊编委会创建、换届或优化提供参考。【方法】 采用德尔菲法和层次分析法,构建我国科技学术期刊编委会运行机制优化指标体系,并确定权重。【结果】 构建由 “编委会组织优化指标体系(宏观)”和 “编委办刊贡献考核指标体系(微观)”组成的“我国科技学术期刊编委会运行机制优化指标体系”。【结论】 本研究集期刊出版界、科技界和期刊评价方的智慧,构建了“我国科技学术期刊编委会运行机制优化指标体系”,将宏观层面优化和微观层面考核相结合,为我国科技学术期刊编委会创建、换届或优化提供指南或参考,以期真正实现我国科技学术期刊的“专家办刊”,进而推动我国科技学术期刊的高质量发展。