Quantification of the Hardened Cement Paste Content in Fine Recycled Concrete Aggregates by Means of Salicylic Acid Dissolution

Adherent hardened cement paste attached to recycled concrete aggregates (RCA) generally presents a higher porosity than natural aggregates, which induces a lower porosity in the properties of RCA. The characterization of the adherent hardened cement paste content (HCPC) in the fine RCA would promote better applications of RCA in concrete, but the determination of HCPC in fine RCA is not well established. A simple method based on salicylic acid dissolution was specifically developed to quantify the HCPC in RCA, especially for RCA containing limestone aggregates. The results demonstrated that the soluble fraction in salicylic acid (SFSA) was equal to the HCPC for white cement and slightly lower for grey Portland cement, which was also confirmed by a theoretical approach using modelling the hydration of cement paste with the chemical equations and the stoichiometric ratios. The physical and mechanical properties of RCA (e.g., water absorption) were strongly correlated to the SFSA. For industrial RCA, SFSA did not give the exact value of HCPC, but it was sufficient to correlate HCPC with the other properties of RCA. The water absorption could be estimated with good accuracy for very fine RCA (laboratory-manufactured RCA or industrial RCA) by extrapolating the relationship between water absorption and HCPC, which is very important for concrete formulation.     

反复吸入2.3%七氟烷对幼年大鼠学习记忆与乙酰胆碱酯酶活性的影响

目的：观察幼年大鼠反复吸入2.3%七氟烷对学习记忆能力的影响.方法：将健康雄性SD大鼠60只随机均分为6组,Con1组、Con3组、Con5组：每天同一时间吸氧1 h,流量0.5 L/min,分别吸1、3、5 d;Sev1组、Sev3组、Sev5组：每天同一时间吸入2.3%七氟烷和流量0.5 L/min氧气的混合气体1 h,分别吸1、3、5 d.末次给药7 d后,进行水迷宫实验,观察大鼠达标所需训练次数、逃避潜伏期及进入盲端的次数,行为学实验后测定乙酰胆碱酯酶活性.结果：与Con1、Con3、Con5组比较,Sev1、Sev3、Sev5组大鼠达标所需训练次数、逃避潜伏期、进入盲端次数以及乙酰胆碱酯酶活性差异均无统计学意义（P〉0.05）.结论：持续5 d,每天吸入2.3%七氟烷1 h,末次给药7 d后对于幼年大鼠空间辨别学习记忆功能无明显影响.     

Protective effects of penehyclidine hydrochloride on acute lung injury caused by severe dichlorvos poisoning in swine

Background Organophosphate poisoning is an important health problem in developing countries which causes death mainly by inducing acute lung injury. In this study, we examined the effects of penehyclidine hydrochloride （PHC）, a selective M-receptor inhibitor, on dichlorvos-induced acute lung injury in swine. Methods Twenty-two female swines were randomly divided into control （n=5）, dichlorvos （n=6）, atropine （n=6）, and PHC （n=5） groups. Hemodynamic data, extravascular lung water index （EVLWI）, and pulmonary vascular permeability index （PVPI） were monitored; blood gas analysis and acetylcholinesterase （AchE） levels were measured. PaO2/FiO2, cardiac index （CI）, and pulmonary vascular resistance indices （PVRI） were calculated. At termination of the study, pulmonary tissue was collected for ATPase activity determination and wet to dry weight ratio （W/D） testing 6 hours post-poisoning. TUNEL assay, and Bax, Bcl-2, and caspase-3 expression were applied to pulmonary tissue, and histopathology was observed. Results After poisoning, PHC markedly decreased PVRI, increased CI more effectively than atropine. Anticholinergic treatment reduced W/D, apoptosis index （AI）, and mitigated injury to the structure of lung; however, PHC reduced AI and caspase-3 expression and improved Bcl-2/Bax more effectively than atropine. Atropine and PHC improved ATPase activities; a significant difference between groups was observed in Ca2＋-ATPase activity, but not Na＋-K＋-ATPase activity. Conclusions The PHC group showed mild impairment in pathology, less apoptotic cells, and little impact on cardiac function compared with the atropine group in dichlorvos-induced acute lung injury.     

中国农村饮用水与环境卫生现状调查

  目的  分析山东省不同农村地区的环境卫生与疾病的现状及区域变化特点,为制定相应的干预和控制措施提供依据。  方法  2015 — 2017年,结合山东省地理位置,按东部、中部、西部进行分层,共选取25个县（市）,采用抽签的方法在每县随机抽取20个自然村,每自然村随机抽取5户家庭,共500个村2 500户,采用统一调查表,通过查阅资料、现场调查、访谈、土壤样品采集、实验室检测等方式收集相关信息。  结果  调查县无害化卫生厕所普及率为53.34 %,东、中、西部的差异有统计学意义（P < 0.05）,无害化卫生厕所普及率与区域的人均年纯收入呈正相关（r = 0.997,P < 0.05）。500个村粗死亡率为563/10万,心脏病、恶性肿瘤、脑血管病是死亡的主要原因。垃圾、污水处理厂人口覆盖率平均为58.50 %和40.80 %,东、中、西部差异有统计学意义（P < 0.05）。农村土壤中蛔虫卵检出率为17.20 %,东、中、西部差异无统计学意义（P = 0.31）,活蛔虫卵检出率为5.20 %,东、中、西部差异有统计学意义（P < 0.05）;东、中、西部的蛔虫卵检出率与人均年纯收入呈显著负相关（r = – 0.998,P = 0.04）。土壤重金属合格率为87.40 %,东、中、西部差异有统计学意义（P < 0.05）,土壤中镉合格率为89.00 %,东、中、西部差异有统计学意义（P < 0.05）。  结论  山东省不同地域的农村环境因素和疾病间明显相关,西部地区土壤中活蛔虫卵检出率偏高;东部地区土壤污染的主要因素是镉;应针对不同地域特点采取相应的干预和控制措施。     

2013 — 2014年昆明市游泳池水的致病菌污染研究

  目的  了解辽宁省游泳场所池水卫生状况,特别是微生物指标情况,为加强游泳场所卫生管理和水质监测提供参考。  方法  2014 — 2018年连续5年对全省游泳场所水质按照国家标准检验方法进行检测,分别检测其细菌总数、大肠菌群、尿素、浊度、余氯、pH,根据国家标准判定其合格情况并加以分析。  结果  2014 — 2018年分别检测207、249、287、306、326户游泳场所水质,5年水质总合格率分别为72.95 %、75.50 %、87.80 %、80.72 %、84.97 %,均值为81.09 %。细菌总数、大肠菌群、尿素、浊度、余氯、pH合格率均值分别为93.09 %、97.09 %、96.22 %、99.85 %、89.81 %、98.69 %。全省14个市泳池水质总体合格率为68.87 %～94.55 %,不同地区游泳池水细菌总数、大肠菌群、尿素、浊度、余氯和pH合格率差异无统计学意义。细菌总数合格率分别与余氯、pH合格率显著相关,大肠菌群合格率与尿素、浊度、余氯、pH合格率显著相关。  结论  全省游泳场所水质单项指标合格率较高,微生物致病风险较低。水质总合格率在正常可控水平且逐年上升。不同地区间各指标合格率差异不显著,微生物指标与理化指标之间存在关联。     

Beverage and water intake of healthy adults in some European countries

Abstract

Introduction: Nutritional surveys frequently collect some data of consumption of beverages; however, information from different sources and different methodologies raises issues of comparability. The main objective of this review was to examine the available techniques used for assessing beverage intake in European epidemiological studies and to describe the most frequent method applied to assess it. Materials and methods: Information of beverage intake available from European surveys and nutritional epidemiological investigations was obtained from gray literature. Results: Twelve articles were included and relevant data were extracted. The studies were carried out on healthy adults by different types of assessments. The most frequent tool used was a 7-d dietary record. Only Germany used a specific beverage assessment tool (Beverage Dietary History). Conclusion: From the limited data available and the diversity of the methodology used, the results show that consumption of beverages is different between countries. Current epidemiological studies in Europe focusing on beverage intake are scarce. Further research is needed to clarify the amount of beverage intake in European population.     

Evaluation of the Colilert® Test for Detection of Verotoxin-Producing Escherichia coli in Water

ABSTRACT

The objective of this study was to estimate the sensitivity of the Colilert® test for detection of different isolates of Escherichia coli (E. coli) O157:H7 and other verotoxin-producing E. coli (VTEC) serotypes from water for potential on-farm food safety application. E. coli isolates evaluated were of human, bovine, porcine, or food origin. The sensitivity of the Colilert® test was 92% overall for the verotoxin-producing serotypes of E. coli. However, none of the E. coli O157:H7 isolates were identified as E. coli. No false-positive results for E. coli were detected. The Colilert® test could be used to screen water supplies for E. coli on the farm, however, an important pathogenic E. coli sero-type is not detected by the Colilert® test.     

Influence of Humans on Evolution and Mobilization of Environmental Antibiotic Resistome

The clinical failure of antimicrobial drugs that were previously effective in controlling infectious disease is a tragedy of increasing magnitude that gravely affects human health. This resistance by pathogens is often the endpoint of an evolutionary process that began billions of years ago in non–disease-causing microorganisms. This environmental resistome, its mobilization, and the conditions that facilitate its entry into human pathogens are at the heart of the current public health crisis in antibiotic resistance. Understanding the origins, evolution, and mechanisms of transfer of resistance elements is vital to our ability to adequately address this public health issue.     

富氧水对高原移居半年青年运动后肾功的影响

目的探讨在高原口服富氧水对移居半年青年运动后肾功的影响。方法在海拔3700 m选择10名已习服半年的健康男性青年,采用口服富氧水前(对照组)后(实验组)的自身对比运动负荷双盲实验。实验组口服富氧水,对照组口服5%葡萄糖注射液,每次500 ml,2次/d,连续服用3 d。运动结束后检测血中肌酐(CRE)、尿素氮(BUN)及尿酸(UA)在口服富氧水前后的变化。结果实验组较对照组CRE、BUN和UA均降低,有显著性差异(P<0.01)。结论富氧水可改善低氧环境下肾组织的损害,对高原低氧环境下的肾脏有保护作用。