酸化污泥中重金属在电动力作用下的去除率研究

分析了长沙市某污水处理厂污泥中重金属分布.对污泥样品用HNO3进行酸化处理,酸化后pH值为3.2、1.9.分析了酸化处理后Cd、Zn、Cu在污泥中的形态分布.重点研究了酸化污泥中的Cd、Zn、Cu在电动力作用下的去除率.酸化污泥在电动力的作用下,经过5 d后,Cd、Zn的去除率明显提高,Cu的去除率提高相对较少.针对我国污泥中Zn含量较高的特点,提出在污泥厌氧消化处理时,同时用电动力处理污泥中的重金属,可大大提高重金属的去除率.     

施用城市污泥对土壤中重金属积累和迁移的影响

目的 了解城市污泥农用后土壤重金属的积累和迁移。方法 于1998年分不同季节，从苏州、无锡、常州3个城市污水处理厂采集污泥样本，用原子吸收光谱仪分析样本中重金属(Pb、Zn、Cu、Cd、Hg、As)含量和不同形态含量，分析污泥农用后土壤重金属积累及迁移特性。结果 城市污泥重金属含量远高于土壤背景值，3城市污泥中Zn含量均超标，分别达到1199，00、784．00、1216．00mg／kg。长期施用能导致土壤重金属积累。污泥中重金属具有一定的活性和潜在迁移性。结论 城市污泥农用可能会导致土壤和生物体重金属积累，存在着一定的环境重金属积累风险。     

猪粪、底泥和土壤中6种重金属测定与污染情况分析

目的 了解猪粪、底泥和土壤中的重金属污染情况。方法 采集某县2个不同规模生猪养殖场的猪粪、附近水源水底淤泥和农田土壤样品，参照GB/T 17141—1997,采用酸消化法对样品进行消化处理，通过测定标准物质确定和优化测定方法后，采用石墨炉原子吸收光谱法(GF-AAS)测定重金属Cd,电感耦合等离子体发射光谱法测定重金属元素Pb、Cu、Zn、Cr、Ni等，绘制标准曲线，计算方法的检出限和定量限，测定30份样品含量后对其重金属含量进行评估。结果 Pb在0～500μg/L,Cd在0～10μg/L,Cu、Ni、Cr、Zn在0～1 000μg/L质量浓度范围内线性良好，相关系数均>0.999;相对标准偏差(RSD):Cd为1.50%～5.12%,Pb、Cr、Cu、Zn、Ni为1.25%～3.52%;方法检出限：Cd为0.042 mg/kg, Pb、Cr、Cu、Zn、Ni分别为0.038、0.048、0.162、0.044、0.384 mg/kg。与底泥和土壤样品相比，猪粪样品中Cu、Zn、Cd的含量较高，Pb、Cr、Ni含量较低，差异均有统计学意义(t值分别为6.78～36.12,P值均&...     

潮白河顺义段及汉石桥湿地水体中重金属污染现状分析

目的 了解潮白河顺义段及汉石桥湿地水体中重金属的污染水平，为该地区再生水补水湿地的管理提供参考数据。方法 在潮白河顺义段及汉石桥湿地分别选取采样点，于2021年4月（枯水期）和10月（丰水期）采集水样，对Zn、Cu、As、Pb、Cd、Cr这6种重金属元素进行定量分析，了解两处湿地水体中6种重金属元素的污染水平。结果 两处湿地水体中6种重金属元素的浓度为0.06～9.72μg/L，均低于国家地表水Ⅲ类水质标准。枯水期各采样点水体中Zn、Cu和As浓度均高于丰水期（均P<0.05）。结论 潮白河顺义段与汉石桥湿地水体中Zn、Cu、As、Pb、Cd、Cr这6种重金属元素的污染水平较低。     

边疆牧区中小学生头发中锌,铜元素的测定

为了解边疆牧区中小学生头发中Zn、Cu的含量，对内蒙古自治区阿盟左旗蒙、回及吉兰泰苏木乡汉族中小学校7－18岁中小学生共321人的发Zn、Cu进行了测定，结果显示，牧区中小学生发Zn平均含量为167．02μg／g，女为162．34μg／g；发Cu平均含量为15．55μg／g，女为14．00μg／g。对不同年龄组及不同民族的学生发Zn、Cu含量也进行了比较。     

某农场土壤重金属污染特征及其健康风险评价

目的评价某农场土壤中重金属污染物对人体健康产生的潜在威胁。方法在对该农场8个采样点进行土壤中Cd、Ph、Zn、Cu4种重金属检测的基础上,建立土壤环境污染健康风险评价模型,并对土壤一人体所引起的健康风险作出初步评价。结果8个采样点土壤中Cd、Pb、Zn、Cu4种重金属的平均质量浓度分别为0．06～0．34、38．25—127、45．28～156．43和5．61～22．40mg／kg。致癌污染物cd对人体健康危害的个人年风险水平均集中在10-6／a,最大值为1．9×10-6／a。非致癌污染物（Pb、Zn、Cu）所引起的健康危害的个人年风险顺序为Pb〉Zn〉Cu。3种非致癌污染物对人体健康危害的个人年风险水平均集中在10-5～10-2／a。结论该农场土壤中Cd、Pb、Zn、Cu4种重金属低于国家土壤环境质量二级标准,所引起的健康风险比较小。     

医疗垃圾焚烧炉飞灰水泥固化体的浸出特性研究

为检验医疗垃圾焚烧飞灰的水泥固化处理效果,对不同养生龄期及不同飞灰／水泥配比下飞灰水泥固化体重金属渗沥特性进行了实验研究。结果表明：随养生龄期的延长,水泥固化体中的Zn、Pb、Cu等重金属渗沥浓度总体上是逐渐降低的;掺40％飞灰、60％飞灰养生28d的水泥固化体中Pb渗沥浓度分别为5．634、6．032mg／L,超过5mg／L的限值。若按照目前国内生活垃圾焚烧飞灰水泥固化工艺的配比（水泥掺量40％以下）,重金属渗沥指标不能达到填埋要求。     

吉林省居民发中重金属含量的测定

目的了解吉林省居民体内重金属的含量,研究人体中重金属是否受年龄、性别、城市环境及经济水平的影响。方法于2017年9—12月采集吉林省居民发样为研究样本,将其长久居住地分为9个城市,用等电感耦合离子发射光谱法(ICP-OES)对不同城市居民发样中所含的重金属含量进行测定。通过聚类分析法探求不同城市居民发样中重金属的可能来源,通过线性回归分析法分析不同城市居民发中重金属含量水平与年龄、性别及不同城市可吸入颗粒物(PM10)与国内生产总值(GDP)的相关性。结果吉林省居民发样中5种重金属Cr、Cu、Ni、Pb、Zn含量中位数(M)分别为53.62、77.00、71.99、808.08、317.75μg/g。居民发中重金属含量在20～29岁年龄段最低,5种重金属总浓度为1 068.70μg/g;在40～49岁年龄段最高,总浓度为1 764.76μg/g,重金属含量与年龄无线性关系。男性发样中重金属含量为3 173.69μg/g,女性为1 643.58μg/g,其中男性发样中Cr、Cu、Ni、Zn的含量高于女性,女性发样中Pb的含量高于男性。除Cr含量与PM10浓度有相关性外(r=0.351),其余重金属含量与PM10及GDP均不相关(均P0.05)。结论吉林省居民存在较高的重金属暴露风险,重金属含量与性别有关,与年龄、环境情况、经济状况尚未见相关关系,其相关性还需进一步探究。     

不同钝化剂对污泥堆肥过程中重金属形态的影响研究

利用污泥和秸秆进行高温堆肥,研究粉煤灰、磷矿粉、沸石和草炭4种钝化剂对污泥堆肥中重金属（Cu、Zn、Pb、Cr）形态的影响。结果表明：堆肥过程中添加钝化剂可有效降低污泥中重金属有效态的含量,其中以粉煤灰的钝化效果最为显著。粉煤灰用于污泥堆肥不仅实现污泥的资源化,而且解决了粉煤灰的利用问题。     

山东某大学116例学生头发中重金属含量调查

目的调查山东某大学学生头发中重金属的含量及可能的影响因素。方法采集山东某大学116位大学生的头发样本,测定其中Pb、Cd、Cu、Zn的含量,并用统计分析的方法从性别、生源地及是否染发等方面分析影响头发中重金属元素含量的可能因素。结果样本中Pb含量平均值为8.99μg/g,Cd为0.44μg/g,Cu为8.87μg/g,Zn为50.49μg/g,其中Zn含量低于建议值,染发同学头发中的Pb含量明显高于非染发同学头发中的含量;男女生4种重金属元素含量差异不显著;不同生源地学生头发中Cu、Zn含量差异不显著,但来自淄博地区的学生头发样本中Cd、Pb含量均显著高于其他地区;城市生源学生头发中重金属含量高于农村生源学生,Pb、Cu、Zn 3种重金属在组间存在显著差异性。结论样本中4种重金属元素含量与正常值相比均未超标,但大学生存在缺Zn问题;性别、生源地(除淄博外)不是影响头发中重金属元素含量的可能因素;城市源或农村源是影响头发中Pb、Cu、Zn含量的可能因素;是否染发是影响头发中重金属元素含量Pb的可能因素,这进一步证实染发对人体健康有潜在危害。     

Antimalarial activity from three ascidians: an exploration of different marine invertebrate phyla

Recent research suggests that marine organisms may produce compounds with activity against malaria parasites. Of a total of 27 aqueous extracts from different marine species, collected on the northwest Cuban coast, 20 were considered as showing no significant activity against Plasmodium falciparum F32, with minimum inhibitory concentrations (MIC) >500 microg/ml, while seven extracts (MIC < or =500 microg/ml) were selected for further investigation by determining their selectivity indices and in vivo antimalarial activity. Three species of tunicates were chosen, as more than 50% reduction of P. berghei parasitaemia was produced after administration of 250 or 500 mg/kg of their crude extracts into infected mice. The aqueous extracts of Microcosmus goanus, Ascidia sydneiensis and Phallusia nigra were partitioned between water and n-butanol; the organic phases inhibited P. falciparum growth by 50% at concentrations of 17.5 microg/ml, 20.9 microg/ml and 29.4 microg/ml respectively. In general, these results are similar to those of most ethnobotanical surveys. Further chemical studies are being undertaken in order to isolate new antimalarial compounds from these Caribbean tunicates.     

Multigeneration acclimation of Daphnia magna Straus to different bioavailable copper concentrations

A large acclimation experiment was performed with Daphnia magna in which two different copper bioavailability (as Cu2+) groups (N and M) were used. In the N group the cupric ion activity increased with increasing dissolved copper-acclimation concentration, while in the M group the ion activity decreased with increasing dissolved copper concentration. The activity of copper carbonates and hydroxides was up to an order of magnitude lower than the cupric ion activity. After five generations of acclimation, the acute copper sensitivity (mean +/- SD) of the N group ranged from 193 /- 24 to 296 +/- 50 microg Cu L(-1) and for the M group from 198 +/- 27 to 315 +/- 38 microg Cu L(-1) for daphnids acclimated to 1 and 100 microg Cu L(-1), respectively. The internal copper concentration of the acclimated daphnids also resulted in similar results between the two groups. Acclimation of the two daphnid groups for five consecutive generations to the three dissolved copper concentrations resulted in a shift in the optimal concentration range toward 1 microg Cu L(-1), using energy reserves as an endpoint. Our results suggest that copper acclimation and accumulation are related to the dissolved copper concentration of the culture medium, but not to the copper activity.     

Comparison of different anthelminthic drug regimens against Mansonella perstans filariasis

Mansonella perstans filariasis is widely present in Africa and equatorial America and its pathogenicity has recently been reconsidered. Effective treatment is lacking and there is no consensus on the optimal therapeutic approach. The aim of this study was to compare the effects of different drug regimens on M. perstans infection. Six different anthelminthic therapeutic protocols were undertaken on 165 subjects with M. perstans infection and their effects on microfilariae burden were evaluated. Diethylcarbamazine (DEC) was able to reduce microfilariae density in the majority of cases, but it seldom eliminated infection after a single treatment. Mebendazole appeared to be more active than DEC in eliminating the infection, with a comparable rate of overall responses. Ivermectin and praziquantel showed no modification of microfilariae concentration. Thiabendazole showed a small but significant activity against the infection. Combination treatments (DEC plus mebendazole) resulted in a significantly higher activity than the single drugs.     

Effectiveness of the whole-cell pertussis vaccine produced in Poland against different Bordetella parapertussis isolates in the mouse intranasal challenge model

The aim of the study was to evaluate the effectiveness of the whole-cell pertussis vaccine produced locally and routinely used in Poland in the elimination of Bordetella parapertussis strains from the lungs and trachea of a mouse model. We found that the average protective effect against B. parapertussis in the lungs of mice immunized with the whole-cell pertussis vaccine (DTwP) was significantly higher than in animals immunized with the acellular pertussis vaccine (DTaP). The effectiveness of B. parapertussis elimination rates from the lungs of DTwP-immunized mice, depending on the strain used as a challenge, was found to be 1.2-3.0 times or 3.1-7.0 times lower than against Bordetella. pertussis Tohama I or vaccine B. pertussis 606/67 isolates, respectively. Our results show that the locally produced DTwP vaccine is able to protect against B. parapertussis isolates; however, the level of protection and course of B. parapertussis infection in the lungs and trachea seems to be strain specific.     

Evaluation of different methods to recover meticillin-resistant Staphylococcus aureus from hospital environmental surfaces

The environment is implicated as a source of healthcare-associated infections (HAIs) and there is a need for evidence-based approaches to environmental sampling to assess cleanliness and improve infection prevention and control. We assessed, in vitro, different approaches to sampling the environment for meticillin-resistant Staphylococcus aureus (MRSA). In a laboratory-based investigation, the recovery of MRSA from two common hospital environments using six different sampling methods was evaluated, with a wild-type strain of MRSA. A 100 cm² section of mattress and a laboratory bench surface were contaminated with known inocula of MRSA. Bacteria were recovered by sampling at 30 min after inoculation, using either saline-moistened cotton swabs, neutralising buffer swabs, eSwabs or macrofoam swabs, which were all enriched in tryptone soya broth, or by sampling with direct contact plates or chromogenic ‘sweep’ plates. The sensitivity (i.e. the minimum number of bacteria inoculated on to a surface which subsequently produced a positive result) of each method was determined for each surface. The most sensitive methods were eSwabs and macrofoam swabs, requiring 6.1 × 10⁻¹ and 3.9 × 10⁻¹ MRSA/cm², respectively, to produce a positive result from the bench surface. The least sensitive swabbing method was saline-moistened cotton swabs, requiring 1.1 × 10³ MRSA/cm² of mattress. The recovery of bacteria from environmental samples varies with the swabs and methodology used and negative culture results do not exclude a pathogen-free environment. Greater standardisation is required to facilitate the assessment of cleanliness of healthcare environments.     

A comparative study of different diets to optimize cultivation of Hyalella azteca in the laboratory

The aim of this study was to assess the influence of four diets on the laboratory cultivation of H. azteca, seeking to improve production of young specimens through reduced mortality and better growth and number of offspring per couple. The best diet was composed of a mixture of diluted commercial fish food, diluted yeast and primrose oil, associated with fish food flakes containing spirulina. With this diet the maximum mortality was 25 percent (at the end of 28 days), the average number of offspring/couple was 11.4±2.8 (at the end of twelve days) and the peak weight and length of the males (at the end of 40 days) were 0.930 μg and 5.26±1.1 mm, respectively.     

Appearance of Fim3 and ptxP3-Bordetella pertussis strains, in two regions of Sweden with different vaccination programs

After introduction of a mono-component vaccine, containing only pertussis toxoid (PT), the incidence of pertussis was significantly higher in the Gothenburg area among children during the period October 1, 1997 until end of 2006 compared to the Rest of Sweden where a vaccine containing PT and two other pertussis antigens was used. To investigate a possible cause of this difference, the Bordetella pertussis populations in both regions were compared by determining the fimbrial serotype (Fim), the PFGE-type and the pertussis toxin promoter allele type (ptxP). Strains with the ptxP1 allele were successively replaced by ptxP3 strains producing more pertussis toxin. In Gothenburg compared to the Rest of Sweden, Fim3 and ptxP3 strains were observed earlier and reached higher frequencies in the studied period. Since ptxP3 strains have been shown to be more virulent, their higher prevalence may have contributed to the higher incidence of pertussis in the Gothenburg area. In addition we found a high degree of linkage between PFGE-profile and ptxP3. Our results highlight the importance of strain typing to gain insight into the mechanisms of immunity-associated selection of microbial subtypes and the causes of changes in incidences of infectious diseases.     

Evaluation of serotype-specific pneumococcal IgG measurement using two different polysaccharides from ATCC and SSI Diagnostica

Streptococcus pneumoniae (pneumococcus) is a major cause of morbidity and mortality especially in infants and elderly people. Pneumococcus capsular polysaccharide has been characterised and more than 90 different serotypes have been identified. Serotype-specific antibodies against the capsular polysaccharide are produced during infection.At present, many countries follow the WHO pneumococcal ELISA IgG measurement protocol, in which polysaccharides from ATCC are used as antigens. In recent years, serotype specific polysaccharides from different producers have been tested in pneumococcal antibody assay's. In this project, purified serotype specific pneumococcal antigens from SSI Diagnostica and from ATCC were compared. In general, the data showed that both types of polysaccharide could be used as antigens. Furthermore, the effect of adsorption using different combinations of adsorption procedures was tested, showing similar results using CWPSmulti or CWPS + 22F.     

我国不同人群生殖支原体感染率的Meta分析

目的:生殖支原体（Mg）主要通过性接触传播,近年来国内外学者对生殖支原体感染和致病给予了较多的关注。本文旨在全面了解生殖支原体在我国不同人群泌尿生殖道中的感染情况,为进一步研究其致病特性提供依据。方法:检索中国期刊全文数据库（CNKI）、万方数据知识服务平台、中国生物医学文献服务系统（SinoMed）、PubMed、W...     

Variable protection after vaccination of broiler chickens against necrotic enteritis using supernatants of different Clostridium perfringens strains

Necrotic enteritis is an economically important disease of chickens caused by Clostridium perfringens. Immunity to necrotic enteritis is not fully characterized yet, but previous reports indicate that immunoprotective potential is present in the secreted component of C. perfringens. This study aimed to compare the vaccine potential of the supernatants of eight chicken strains of C. perfringens differing in origin, level of alpha toxin production and presence of netB gene. The supernatant of only one strain provided full protection, while one other strain provided partial protection against a severe infection challenge. Our results indicate that the protective characteristics of the supernatants are not solely based on the presence of NetB or alpha toxin.