Reproduction,blood and plasma parameters and gill histology of vendace (Coregonus albula L.) in long-term exposure to acidity and aluminum

Vendace were exposed to pHs 4.75 and 5.25 with or without added aluminum (200 microg=7.4 micromol AlL(-1)) from late endogenous vitellogenesis in July through the spawning period. At the normal time of spawning, when 48% of the control females had already released their eggs, 50% of females at pH 4.75+Al had completely unovulated oocytes. The final proportions of completely ovulated females were 14%, 36%, 25%, 61%, and 81% at pH 4.75+Al, pH 4.75, pH 5.25+Al, pH 5.25, and in the control group, respectively. Delayed testes regression was seen in males at pH 4.75+Al. A clear decrease in plasma Na(+) and Cl(-) and an increase in blood glucose concentration was detected only near spawning time, from October to November, coincident with Al accumulation inside the gill tissue. It is concluded that seasonal changes, probably related to reproductive physiology or to the decrease in water temperature, are associated with the increase in Al toxicity in vendace.     

论I~-和SeO_3~(2-)的共液共存——低钠盐的稳定性

本文以化学理论和试验证明微量Ⅰ~-和SeO_3~(2-)离子在pH=3～8的冷、热溶液中可稳定共存。为在保健食品如低钠盐中的存在提供理论依据。     

运用回归分析方法控制酸奶的最终酸度

酸奶的酸度是影响口感的重要质量指标,运用数理统计学上的回归分析方法控制杆菌使用的百分比,从而使得产品的酸度稳定在满意的水平上。     

酸碱平衡体系基于Excel的直观计算

基于Excel工作表与宏,建立包含公式的酸碱平衡体系模板,计算滴定过程中的酸度变化,绘制滴定曲线,判断滴定突跃,整个过程简便直观。该方法可修改参数,求解未知量(如酸度、物料浓度与体积、酸常数、缓冲容量等),同时由于没有计算公式的简化,计算结果更为准确。     

食品的酸度对菌落总数检验结果的影响研究

[目的]研究酸度对菌落总数检验结果的影响。[方法]将已灭菌的盐酸溶液，加入食品溶液中，调出不同的酸度，再测出其菌落总数。比较不同酸度下同一食品菌落总数的不同。[结果]随着pH值的减小，即酸度的增大，食品中菌落总数的检验结果越来越小，当pH值小于等于2．0左右时，可完全抑制菌落的生长。[结论]酸度的高低一定会影响食品中菌落总数的检验结果，只有将酸度调至中性，才能检测出食品中菌落总数的真正结果。     

Experimental observations and mathematical considerations on the mechanism of transport of uric acid across human gastric mucosa

Summary Under standardized experimental conditions it is shown that the uric acid concentration in human gastric juice is pH-dependent. The gastric uric acid concentration falls as a hyperbolic function with increasing acidity of gastric juice. Normally a concentration ratio of uric acid between gastric juice and plasma in the range of 0.2–0.4 will be found. These results are compatible with the conception of uric acid transport by means of non-ionic diffusion. In theoreticalmathematical considerations rate limiting factors on non-ionic diffusion of a weak acid from plasma into gastric juice are described.     

Burow's solution-induced acute sensorineural hearing loss: Report of two cases

This is the report of rare cases to show the potential ototoxicity of Burow's solution in clinical use. We encountered two cases of acute sensorineural hearing loss occurring after the administration of 8% Burow's solution (pH 2.93) into the tympanic cavities. Prior to treatment, both cases presented with tympanic membrane perforations in the posterior and inferior portions and a small amount of serous discharge. Fortunately, hearing loss recovered almost completely except for high tones within a few weeks. These two case reports demonstrate that the ototoxicity of Burow's solution should be considered when it is used to treat otitis media accompanied by tympanic membrane perforation.     

Interactive effects of ambient acidity and salinity on thyroid function during acidic and post-acidic acclimation of air-breathing fish (Anabas testudineus Bloch)

The interactive effects of ambient acidity and salinity on thyroid function are less understood in fish particularly in air-breathing fish. We, therefore, examined the thyroid function particularly the osmotic and metabolic competences of freshwater (FW) and salinity-adapted (SA; 20 ppt) air-breathing fish (Anabas testudineus) during acidic and post-acidic acclimation, i.e., during the exposure of fish to either acidified water (pH 4.2 and 5.2) for 48 h or clean water for 96 h after pre-exposure. A substantial rise in plasma T₄ occurred after acidic exposure of both FW and SA fish. Similarly, increased plasma T₃ and T₄ were found in FW fish kept for post-acidic acclimation and these suggest an involvement of THs in short-term acidic and post-acidic acclimation. Water acidification produced significant hyperglycaemia and hyperuremia in FW fish but not in SA fish. The SA fish when kept for post-acclimation, however, produced a significant hypouremia. In both FW and SA fish, gill Na⁺, K⁺-ATPase activity decreased but kidney Na⁺, K⁺-ATPase activity increased upon acidic acclimation. During post-acidic acclimation, gill Na⁺, K⁺-ATPase activity of the FW fish showed a rise while decreasing its activity in the SA fish. Similarly, post-acidic acclimation reduced the Na⁺, K⁺-ATPase activity of intestine but elevated its activity in the liver of SA fish. A higher tolerance of the SA fish to water acidification was evident in these fish as they showed tight plasma and tissue mineral status due to the ability of this fish to counteract the ion loss. In contrast, FW fish showed more sensitivity to water acidification as they loose more ions in that medium. The positive correlations of plasma THs with many tested metabolic and hydromineral indices of both FW and SA fish and also with water pH further confirm the involvement of THs in acidic and post-acidic acclimation in these fish. We conclude that thyroid function of this fish is more sensitive to environmental acidity than ambient salinity and salinity interference nullifies the toxic effect of water acidification.     

中海胃痛茶抗实验性胃溃疡作用

笔者采用中海胃痛茶灌胃实验,治疗小鼠应激型胃溃疡,大鼠幽门结扎型和醋酸损伤型胃溃疡结果表明其具有显著的抗溃疡作用,尚能明显减少小鼠扭体反应次数和对抗氯化钡所致豚鼠离体回肠收缩,降低大鼠胃液总酸度,但对胃液总量,胃蛋白酶活性,小鼠胃肠运动,出血和凝血时间的作用不明显,提示中海胃痛茶具有解痉,镇痛和抗溃疡作用,为临床应用中海胃痛茶治疗胃溃疡提供实验依据。     

酸性氧化电位水现场消毒效果试验研究

目的验证酸性氧化电位水的现场消毒效果。方法参照国家卫生部有关消毒规范方法对医务人员手、一般物体表面、医疗器械、消化内镜分消毒组与阳性对照组进行现场消毒试验。结果对30人次手消毒作用1 min,自然菌平均杀灭对数值为2.72;对物体表面作用5 min,自然菌平均杀灭对数值>1.00;对使用后一般医疗器械常规清洗后浸泡消毒10 min,器械表面细菌的总平均杀灭对数值>1.00;对使用后胃镜、肠镜常规清洗和酶洗处理后消毒3 min,各内镜细菌总数范围为0~2 CFU/件,且均未检出致病菌;试验各组均消毒合格。结论酸性氧化电位水的现场消毒效果良好。