Influence of dust storms on atmospheric particulate pollution and acid rain in northern China

Northern China is the area with the highest incidence of dust storms in the world, which are the main sources of its soil dust emissions. In addition, the region consumes huge amounts of fossil fuels and has serious atmospheric particulate pollution. Existing observation results show that a single dust storm has significant influence on atmospheric particulate pollutant concentrations and precipitation acidity. Proving the influence of dust storms on atmospheric particulate pollution, acid rain, and the acid rain ratio and determining whether there is a causal relationship among them on a longer time scale will help us recognize the impact of dust storms on the atmospheric environment. This paper proves that dust storms are the direct cause of the variations in the number of acid rain days and acid rain ratio, as well as the changes in atmospheric particulate pollution, in spring by using the Granger Causality Test and correlation analysis methods based on 1993 to 2007 data, including the number of days of dust storms, atmospheric particulate pollution, and acid rain. Atmospheric particulate pollution is the direct cause of variations in the number of acid rain days and the acid rain ratio in spring; for the other seasons, additional data combined with atmospheric particulate pollution are needed to explain the causes of the acid rain day and ratio changes.     

Organic acids contribute to rainwater acidity at a rural site in eastern China

We collected 43 valid rainwater samples at Lin’an, a rural site in eastern China, between March 2014 and February 2015. We measured the concentrations of seven low molecular weight water-soluble organic acids using ion chromatography with the elution gradient method. We detected formic, acetic, oxalic, succinic, glutaric, malonic, and methanesulfonic acid in at least 70% of all samples, reflecting the ubiquity of these acids in the precipitation of Lin’an. The total concentration of these organic acids in individual samples was between 2.63 and 114.77 μeq L^?1 (mean 16.64 μeq L^?1). Formic, acetic, and oxalic acid were the most abundant organic acids in the rainwater samples, with volume-weighted mean concentrations of 9.58, 3.89, and 2.01 μeq L^?1, respectively; these three acids accounted for 93% of the total mean organic acid concentration. The average contribution of organic acids to precipitation total free acidity was 13.71% in Lin’an, which was lower than has been recorded in other rural and mountainous areas of southwestern China, but much higher than has been recorded in some urban and semi-urban areas. The mean ratio of formic to acetic acid in rainwater was 2.40, and the mean ratio of malonic and succinic acid in rainwater was 0.62. These ratios indicated that, in Lin’an, formic and acetic acid mainly originated from primary biogenic sources, but malonic and glutaric acid mainly originated from motor vehicle emissions. With the exception of oxalic acid, the volume-weighted mean concentrations of other organic acids and total organic acids in the growing season (summer and spring) were higher than those in non-growing season (autumn and winter), suggesting that vegetation around the Lin’an sampling site was an important source of atmospheric organic acids. As the volume-weighted mean concentration of oxalic acid was higher during the non-growing season, this may indicate that aerosolized oxalic acid was less well diluted due to less rainfall during the drier non-growing season.     

Temporal variations,acidity, and transport patterns of PM2.5 ionic components at a background site in the Yellow River Delta,China

To better understand the pollution characteristics and potential sources of PM_2.5 ionic components at the Yellow River Delta (YRD), a semicontinuous measurement was conducted to observe water-soluble ions in PM_2.5 at a nature reserve in Dongying of Shandong province, China, in 2011. The results showed that SO₄ ^2?, NO₃ ^?, and NH₄ ⁺ were the dominant ionic species (constituting 93 % of the total ionic mass) with their annual average concentrations of 22.48, 12.77, and 11.21 μg/m³, respectively. These three ion concentrations were generally lower than those observed in major cities in China but higher than those in other rural and nature reserve sites. Ion concentrations exhibited large seasonal variations, and maximum values were observed in summer. SO₄ ^2? concentration presented a daytime peak in summer, autumn, and winter, while in spring, a relative flat diurnal cycle was observed. NO₃ ^? concentration changed with that of SO₄ ^2? during most of measurement period. Transport from surrounding areas contributed to the diurnal cycle of secondary ions. In addition, photochemical reaction and thermodynamic equilibrium played important roles on the diurnal variation of SO₄ ^2? and NO₃ ^?, respectively. The aerosol at the YRD was weakly acidic, and it was most acidic in winter. A cluster analysis showed that fine particle pollution at the YRD was mainly affected by southwest local emissions and northern middle- to long-distance transport.     

Major inorganic ion composition of atmospheric aerosols at the coastal site in Visakhapatnam City--India

Atmospheric aerosols were sampled at a coastal site and analyzed for H+, NH+4, Ca++, Mg++, Na+, SO4- -, HCO(-3), Cl- and No3-. The analysis demonstrated that these ions are the main constituents of the aerosols sampled. The correlation coefficients are calculated for each possible pair of anions and cations. Ionic balance in the ambient aerosols indicate that the main compounds existed are in the order of sodium chloride; bicarbonates of calcium and magnesium; sulphates of sodium, magnesium and calcium; and nitrates of sodium, magnesium and calcium. The existence of cations has exceeded the anions which indicate that ionic composition of the aerosols are not very much determined by background marine nature but may also be due to transport of polluted air masses from the surrounding areas.     

新型冠状病毒肺炎患者出院后核酸检测阳性临床特征及原因综述

从新型冠状病毒肺炎(coronavirus disease 2019, COVID-19)暴发以来,研究发现COVID-19康复患者在出院后在14 d隔离管理或健康监测期间有样本采集核酸检测再次出现新型冠状病毒阳性(复阳)的情况,国内外相关研究报道越来越多。本研究采用文献查阅综述的方法,旨在综合描述COVID-19复阳者临床人口学特征、可能影响因素以及传播风险,为COVID-19患者出院管理、医疗资源救治分配和传播风险控制提供综合科学的建议。     

国境口岸生物恐怖特征及医学现场关键应对要点的分析

目的探讨分析国境口岸生物恐怖特征及医学现场关键应对要点。方法结合《国际卫生条例（2005）》和卫生检疫工作实践,对国境口岸生物恐怖特征及医学现场关键应对要点进行分析和探讨。结果我国面对国际生物恐怖活动的威胁依然存在,国境卫生检疫机构作为第一道防线,应提高认识,从人员防护、技术能力建设、生物战剂样品采集与制备、现场监测、现场排查以及现场处置等方面制定应对措施。结论国境口岸卫生检疫机构应进一步加强生物恐怖医学应对能力建设,切实加强并提高针对生物恐怖活动的防备和应急能力。     

Toxicological characteristics of sebacic acid and the substantiation of its maximum permissible exposure level in atmospheric air]

Average daily MAC of the sebacic acid in the ambient air established at the level of 0.05 mg/m3 (3-d class of hazard). Data of acute and chronic experiments were noted.     

中国2010 — 2016年家庭食源性疾病暴发事件流行特征分析

  目的  了解宁夏地区感染性腹泻的细菌病原谱构成特征以及耐药情况,对预防感染性腹泻以及临床用药提供理论依据。  方法   采集2018 — 2020年宁夏地区感染性腹泻病监测点监测病例样本,采用分离培养的方法对细菌进行鉴定,并对优势菌株采用肉汤稀释法进行药敏实验。  结果   2018 — 2020年共计监测腹泻病例3486例,检出各类病原细菌287株,包括沙门氏菌、致泻性大肠埃希氏菌、小肠结肠炎耶尔森菌、志贺氏菌、肺炎克雷伯菌、金黄色葡萄球菌及奇异变形杆菌。83株沙门氏菌对氨苄西林的耐药率在各年度均为到最高,其次为四环素,头孢唑啉和萘啶酸;对亚胺培南的敏感率最高,在2019和2020年均达到100 %,其次为阿奇霉素。146株致泻性大肠埃希氏菌在各年度对氨苄西林的耐药率最高,敏感率最高的是亚胺培南,其次为头孢他啶、头孢西丁以及阿奇霉素。  结论   2018 — 2020年宁夏地区细菌性腹泻病原谱较为多样,以沙门氏菌和致泻性大肠埃希氏菌居多,是近年来导致宁夏地区感染性腹泻的优势细菌,这2种病原菌均对氨苄西林耐药率最高,对亚胺培南敏感率最高,但不同菌株对不同药物的耐药趋势不同,应继续加强监测并采取有效防控措施。     

Methionine synthase. a possible prime site of the ethanolic lesion in liver.

Among the most important pathways for liver integrity in the body are the two that synthesize methionine and S-adenosylmethionine (SAM) through methylation of homocysteine. Results of studies in this laboratory have demonstrated ethanolic inhibition of one of these pathways catalyzed by methionine synthetase. It has been shown elsewhere that alcohol per se does not inhibit the enzyme, but that the metabolite of ethanol, acetaldehyde, is responsible through the formation of an inhibiting covalent adduct. Because hepatic SAM has been shown to be essential in the transport of fat from the liver, avoiding steatosis and further liver damage, it is entirely feasible that this repression of methionine synthase is an important site of the injurious action of alcohol metabolism in the liver. This loss of activity is particularly important in human beings who cannot produce methionine and SAM by means of the alternate pathway mediated by betaine:homocysteine:transmethylase, because of the lack of production of the betaine substrate for this enzyme.     

Effects of cadmium and simulated acid rain on ammonification and nitrification in soil

A perfusion technique was used to study the effects of 1) simulated acid rain on the mineralization and nitrification of glycine (NH₂-N) or ammonium sulfate (NH₄-N) by adjusting the pH of the perfusates to 3.0, 2.5, or 2.0 with H₂SO₄; and 2) 0, 50, 100, 500, and 1,000μg Cd/g dry weight of soil on the mineralization and nitrification of NH₂-N, both in soil adjusted with H₂SO₄ to pH 3.0 and in soil not exposed to acidity. Ammonification was relatively insensitive to both Cd and acidity, occurring even in soil exposed to pH 2.0 or 1,000 ppm Cd. Nitrification was more sensitive, being retarded in NH₂-N-supplemented soils exposed to pH 2.5 and inhibited in soil exposed to pH 2.O. In NH₄-N-supplemented soils, nitrification was retarded at pH 3.0 and inhibited at pH 2.5. This retardation and inhibition occurred despite the increase in the pH of the perfusates to a noninhibitory level. Nitrification was retarded at 500 ppm Cd and to a greater extent at 1,000 ppm Cd, where nitrite accumulated. The combined effect of exposure to Cd and H₂SO₄ at pH 3.0 was additive rather than synergistic, and even with 1,000 ppm Cd at pH 3.0 some nitrification eventually occurred.     

Chemical characteristics, fatty acid compositions, conjugated linoleic acid contents and cholesterol levels of some traditional Turkish cheeses

The chemical characteristics, fatty acid and conjugated linoleic acid (CLA) contents and cholesterol levels of some traditional Turkish cheeses that are consumed mostly in Turkey were determined in this study. The fatty acid and cholesterol contents and CLA amount of cheeses were analysed as methyl esters by gas chromatography. The aim of this study was to determine the nutritional profile of some Turkish cheeses produced by traditional methods. The major fatty acids of the cheeses were palmitic acid (C(16:0)) and oleic acid (C(18:1)). The saturated fatty acid content of samples changed between 60.80% and 76.57%, while the monounsaturated fatty acid content ranged from 21.42% to 34.05% and the polyunsaturated fatty acid content was between 1.47% and 3.59%. The CLA contents of the cheeses ranged from 0.44 to 1.04 g/100 g in fat. The cholesterol levels of the samples were determined as 44.6-147.69 mg/100 g in cheese.     

Chemical characteristics,fatty acid compositions,conjugated linoleic acid contents and cholesterol levels of some traditional Turkish cheeses

The chemical characteristics, fatty acid and conjugated linoleic acid (CLA) contents and cholesterol levels of some traditional Turkish cheeses that are consumed mostly in Turkey were determined in this study. The fatty acid and cholesterol contents and CLA amount of cheeses were analysed as methyl esters by gas chromatography. The aim of this study was to determine the nutritional profile of some Turkish cheeses produced by traditional methods. The major fatty acids of the cheeses were palmitic acid (C_16:0) and oleic acid (C_18:1). The saturated fatty acid content of samples changed between 60.80% and 76.57%, while the monounsaturated fatty acid content ranged from 21.42% to 34.05% and the polyunsaturated fatty acid content was between 1.47% and 3.59%. The CLA contents of the cheeses ranged from 0.44 to 1.04 g/100 g in fat. The cholesterol levels of the samples were determined as 44.6–147.69 mg/100 g in cheese.     

中国东部沿海地区艾滋病疫情发现策略研究

目的 分析评估浙江省台州市历年来艾滋病患者“晚发现”现状及其可能的影响因素.方法 利用全国艾滋病综合防治信息系统数据库,收集1996年1月～2014年6月报告地为“浙江省台州市”的艾滋病患者个案信息,包括社会人口学特征、感染途径、HIV检测类型等.运用x2检验和多因素Logistic回归进行单因素和多因素统计学分析晚发现艾滋病病例流行病学特征及相关影响因素.结果 1664例艾滋病病毒感染者或艾滋病病人(HIV/AIDS)纳入本次分析,其中550例(33.1％)属于“晚发现”病例.550例晚发现病例平均年龄为(41.7±14.2)岁;性别以男性为主,占74.4％;58.0％已婚;感染途径以异性传播为主,占73.8％,同性传播占18.0％.Logistic回归分析显示年龄越大,台州市户籍及临床就诊者检测是台州市艾滋病患者“晚发现”主要因素.结论 浙江省台州市艾滋病患者“晚发现”现象较为普遍,急需进一步扩大监测检测覆盖面,加大HIV检测服务宣传,提高HIV检测服务可及性和利用率,特别是医疗机构医务人员应进一步主动为患者提供HIV咨询检测服务.     

Hepatocellular carcinoma; characteristics and possible etiologies in a group of Egyptian patients.

62 Hepatocellular carcinoma (HCC) were studied to define some possible high risk group. The males to females ratio was 3:1, and the age ranged from 24-77 years. A high percentage of history of schistosomal infection, Jaundice, blood transfusion, cirrhosis and also contraceptive pill users among the females were found. The duration of the presenting symptoms and the survival since diagnoses were analyzed.     

中国西部某市室内环境因素及PM2.5对肺功能影响

目的 了解中国西南部高频用煤地区酸雨城市室内环境危险因素对肺功能的影响。方法 于2011年11月-2012年3月采用简单随机抽样方法对贵州省遵义市城区215名成年人进行问卷调查,并检测用力肺活量（FVC）、1 s用力呼气量（FEV1）及FEV1/FVC;此外,检测室内、外PM_2.5浓度。结果 冬季暴露于燃煤、烹饪油烟、吸烟等危险因素与肺功能（FVC、FEV1）呈负相关。厨房与客厅或卧室隔开者FVC、FEV1、FEV1/FVC值（3.5、3.4、93.4）高于未隔开者（3.4、3.2、93.9）,室内无老鼠和蟑螂者（3.5、3.4、93.2）高于暴露者（3.0、2.8、92.1）,未吸烟者（3.6、3.5、93.4）高于吸烟者（3.4、3.2、93.2）和戒烟者（3.2、3、93.2）（除FVC、FEV1外,均P<0.05）,同卧室居住人数<3人者（3.5、3.4、93.4）高于≥3人者（2.7、2.5、91.8）（3项指标均P<0.05）;对21户厨房、卧室和室外PM_2.5浓度进行检测,其中位数（P₂₅~P₇₅）结果分别为517.0（483.5~616.0）、484.0（462.5~602.0）及398.0（378.5~411.5）CPM（P<0.05）;厨房、卧室PM_2.5与FEV₁/FVC呈负相关（P<0.05）。结论 冬季室内环境因素燃煤、吸烟、宠物过敏源等是成人肺功能降低的危险因素。     

35 498例伤害住院患者伤害发生类型和外部原因帕累托图分析

目的分析某院伤害住院患者伤害发生类型和伤害发生的外部原因按ICD-10分类汇总情况,为合理配置医疗资源,加强该地区的伤害性疾病防治工作提供可靠依据。方法运用帕累托图法,对该院10年间35498例伤害住院患者伤害发生类型和伤害发生的外部原因进行分析。结果10年间该院伤害住院患者人数逐年上升。利用帕累托图分析发现伤害住院患者伤害发生类型主要有头部损伤,下肢损伤,肩及上肢损伤,各类中毒;伤害发生的外部原因主要有交通事故,跌倒,砸伤、玻璃和刀刺割伤、机器事故。结论采用帕累托图对伤害住院患者伤害发生类型和伤害发生的外部原因构成情况进行分析,找出了该地区伤害患者疾病谱,为医院和相关部门进一步完善该地区急救体系,优化资源配置,进一步做好伤害预防和控制工作提供数据支持。     

Tick bite and Lyme borreliosis risk at a recreational site in England

The risk of tick bite and Lyme borreliosis in a forested area in England with public access was studied over a two-year period. Tick infestation levels were high with more than 1000 members of the public reporting for tick removal at a local clinic. Most of the attached ticks were nymphs (82%) and distinct differences in anatomical sites of attachment were observed in children and adults. Children sustained nymphal bites to the head, neck and axilla region much more frequently than adults (48 vs. 10%), whereas adults were bitten on the lower legs more frequently than children (46 vs. 9%). The vegetation was heavily infested with ticks and high numbers were particularly associated with areas used by deer. The average density of nymphs collected from the vegetation was 14.1 per 10 m²(range 5.1–43.6). Infection rates of these nymphs determined by PCR and indirect IFA ranged from 5.2–17.0%, and the genospeciesBorrelia valaisianaand B. gariniiwere detected, suggesting that birds may be important reservoir hosts in this area. It is estimated that, at the level of tick challenge observed here, at least 50 persons per year may be bitten by infected ticks at this site. However, no cases of Lyme borreliosis have been reported through the clinic follow-up procedure, and sera from 19 forest workers were negative for antibody to B. burgdorferisensu lato. Despite the high challenge from tick bites, this particular recreational forest site poses a low risk of infection to the general public, and prophylactic antibiotic treatment or serological testing following a bite is not justified.