共查询到20条相似文献,搜索用时 15 毫秒
1.
Bing Chen Ludwig V. Lamberts Geert J. Behets Tingting Zhao Mingxiang Zhou Gang Liu Xianghua Hou Guangju Guan Patrick C. D’Haese 《Biological trace element research》2009,131(1):1-12
Whole blood and serum samples of Chinese stable chronic renal failure (CRF) patients (n = 81), hemodialysis patients (n = 135), posttransplant patients (n = 60), and subjects with normal renal function (NRF; N = 42) were collected, as well as water and dialysate samples from five dialysis centers. The concentration of selenium (Se),
lead (Pb), and cadmium (Cd) was measured by atomic absorption spectrometry. The mean serum Se levels in patients with different
degrees of renal failure were significantly lower than those of subjects with NRF (p < 0.01). Pb levels were not increased in renal failure patients, while the Cd levels in patients with various degrees of
renal failure were higher than in subjects with NRF (p < 0.05). After correcting the results of Pb and Cd for hematocrit (Hct) however, Pb levels of dialysis patients were also
increased. In the dialysis population under study, blood Pb and Cd levels were closely related to the time on dialysis, while
contamination of the final dialysate may also contribute to the increased blood Cd and to a less extent Pb levels. Correction
for Hct may be recommended to accurately compare blood Pb and Cd levels in dialysis patients and CRF patients with varying
degrees of anemia to those of subjects with NRF. 相似文献
2.
Gürbay A Charehsaz M Eken A Sayal A Girgin G Yurdakök M Yiğit S Erol DD Sahin G Aydın A 《Biological trace element research》2012,149(1):117-122
Toxic metals are one of the significant groups of chemical contaminants that humans are exposed to by oral, inhalation, and dermal routes. Exposure to these chemicals begins with intrauterine life and continues during lactation period at the first years of life. Breastfeeding has a much more special place than other nutrition options for infants. However, when possibility of contaminant transfer by breast milk is considered, its safety and quality is essential. Regarding infant and mother health and limited number of information on this field in Turkey, measuring contamination levels in breast milk is important. Therefore, in the present study, lead (Pb), cadmium (Cd), nickel (Ni), and arsenic (As) levels were measured by atomic absorption spectrometry in 64 breast milk samples obtained from mothers from Ankara, Turkey. Pb and Ni levels in breast milk samples were found to be 391.45?±?269.01?μg/l and 43.94?±?33.82?μg/l (mean ± SD), respectively. Cd was found only in one of 64 samples, and the level was 4.62?μg/l. As level was below the limit of quantification (LOQ, 7.6?μg/l) in all samples. These findings will accurately direct strategies and solutions of protection against contaminants in order to reduce their levels in biological fluids. 相似文献
3.
Four Novel Resistance Integron Gene-Cassette Occurrences in Bacterial Isolates from Zhenjiang, China 总被引:1,自引:0,他引:1
Huaxi Xu Zhaoliang Su Shengjun Wang Xiaoli Dai Jianguo Chen Fanzhi Kong Yazhen Li Sufang Peng Qixiang Shao Liwei Lu T. Ezaki 《Current microbiology》2009,59(2):113-117
Integrons, which are widely distributed among bacteria and are strongly associated with resistance, are specialized genetic
elements that are capable of capturing, integrating, and mobilizing gene cassette. In this work, we investigated classes 1,
2, and 3 integrons associated integrases genes in 365 bacteria isolates, amplified and analyzed the structure of class 1 integron,
detected 8 resistant gene cassettes [dfr17, aadA5, aadA1, aadA2, dhfrI, aadB, aac(6′)-II, and pse-I], and found four novel gene-cassette arrays. We also found that commensal bacteria in the common microenvironment had the
same integron gene cassette, which provided direct evidence that integron was an important horizontal transmission element. 相似文献
4.
Two kinds of “group A saponin,” Aa and Ab, are present as the main constituent in soybean seed. The saponin composition and content in F1 and F2 seeds derived from the cross parents of Aa and Ab types were analyzed. The “group A saponin” was of Aa–Ab type in all the F1 seeds, and the ratio of Aa type : Aa–Ab type : Ab type was 1:2:1 in the F2 seeds. From these results, it appears that Aa and Ab were controlled by codominant allelic alternatives at a single locus. An investigation of the saponin composition of the seed hypocotyls of 18 wild lines revealed some lines in which “group A saponin” was absent. 相似文献
5.
We have determined the trace element composition of three mushrooms of Basidiomycetes, used in traditional Chinese medicine
using atomic absorption spectrophotometer (AAS). Metal concentrations in mushrooms were 203–401 mg/kg for iron, 22–51 mg/kg
for manganese, 84–116 mg/kg for zinc, 24.1–41.3 mg/kg for copper, 1.6–5.6 mg/kg for lead, 3.3–4.4 mg/kg for chromium, 9.3–11.5 mg/kg
for nickel, 0 mg/kg for vanadium, and 55.3–71 mg/kg for magnesium. The trace metal concentrations in mushrooms are hardly
affected by the ecosystem and soil where they grew, as well as by the mushroom species and trace metal species. The results
can be used to set new standards to control the quality of the three mushrooms of Basidiomycetes—Ganoderma lucidum, Coprinus comatus, and Grifola frondosa. 相似文献
6.
AbstractIn Stockholm, methods for measuring exposure to lead and cadmium from air, food and beverages were studied in 1988 in a group of 15 non-smoking women, as part of the WHO/UNEP HEAL programme. Airborne particles in the breathing zone air (24-hour samples), duplicate diets (24-hour samples), and faeces (all the stools produced) were collected during 7 consecutive days. Blood was sampled before and immediately after the study period. The results confirmed the need for personal monitoring in the assessment of human exposure to lead and cadmium via air and food. There is need for suitable equipment for 24-hour personal air monitoring. On average, dietary lead (26 μg day?1, SD 7.9) contributed more than 80% of the total lead uptake, while dietary cadmium (8.5 μg day?1 SD 2.1) contributed about 99% of the total cadmium uptake. Occasionally consumed foodstuffs with high levels of lead or cadmium seemed to be responsible for a large part of the total weekly intake of lead and cadmium. Fecal lead and cadmium were found to be useful indicators of the total amounts of these metals ingested. Due to the large day-to-day variation observed in the dietary intake of lead and cadmium, the sampling period for duplicate diets and faeces should be at least 5–6 days. 相似文献
7.
Bioaccessibility and Risk Assessment of Cadmium from Uncooked Rice Using an In Vitro Digestion Model
Cadmium (Cd)-contaminated rice is one of the most important sources of cadmium exposure in the general population from some
Asian countries. This study was conducted to assess cadmium exposure from uncooked rice in rural mining areas based on the
bioaccessible fraction of cadmium using an in vitro digestion model. The biotoxic effects of cadmium in uncooked rice from
mining areas were much higher than those in the control area, based not only on their higher total concentration (52.49 vs.
7.93 μg kg−1), but also on their higher bioaccessibility (16.94% vs. 2.38%). In the mining areas, the bioaccessible fraction of cadmium
in uncooked rice has a significant positive correlation with the total concentration of cadmium in rice and there was quarterly
unsafe rice to the public in the mining areas. The results indicated that the in vitro digestion model could be a useful and
economical tool for providing the solubilization or bioaccessibility of uncooked rice in the mining area. The results could
be helpful in conducting future experiments of cooked rice in the vitro model. 相似文献
8.
Identification and management the ''critical risk areas'' where hotspot lead exposures are a potential risk to human health, become a major focus of public health efforts in China. But the knowledge of health risk assessment of lead pollution at regional and national scales is still limited in China. In this paper, under the guidance of ''sources-pathways-receptors'' framework, regional human health risk assessment model for lead contamination was developed to calculate the population health risk in Yunnan province. And the cluster and AHP (analytic hierarchy process) analysis was taken to classify and calculate regional health risk and the decomposition of the regional health risk in the greatest health risk region, respectively. The results showed that Yunnan province can be divided into three areas. The highest health risk levels, located in northeastern Yunnan, including Kunming, Qujing, Zhaotong region. In those regions, lead is present at high levels in air, food, water and soil, and high population density which pose a high potential population risk to the public. The current study also reveals that most regional health risk was derived from the child receptors (age above 3 years) 4.3 times than the child receptors (age under 3years), and ingestion of lead-contaminated rice was found to be the most significant contributor to the health risk (accounting for more than 49 % health risk of total). This study can provide a framework for regional risk assessment in China and highlighted some indicators and uncertainties. 相似文献
9.
与Pi-ta^+等位基因相比,含有Pi-ta^+等位基因的栽培稻具有抗稻瘟病特性。本研究用基因序列分析的方法检测了来自云南的不同栽培稻品种以及不同类型和来源的普通野生稻种和非洲长雄蕊野生稻种中的Pi-ta^+基因,发现Pi-ta地基因在稻属植物中高度保守,但Pi-ta^+等位基因的存在极其稀有。在所检测的栽培稻和野生稻中仅有来源于云南景洪的直立型普通野生稻中含有Pi-ta^+等位基因。而与Pi-ta基因相比,另一个水稻抗稻瘟病基因Pib,经部分同源序列克隆及测序发现该基因在不同野生稻中的变异较大。在所克隆的不同野生稻Pib基因同源序列中,也只有来源于直立型普通野生稻的序列能按该基因的开放阅读框进行正常翻译。对不同类型普通野生稻的抗稻瘟病能力的初步鉴定结果表明,直立型普通野生稻对供试的本地稻瘟病生理小种具有较强抗性,其抗性可能源于所含的Pi=ta^+等位基因及可能有功能的Pib基因。由于普通野生稻与栽培稻同属AA基因组型,因此,云南直立型普通野生稻可通过杂交育种或基因工程途径用于栽培稻的抗稻瘟病性能改良。 相似文献
10.
This paper aims to compare the Cd, Cu, and Pb concentration in the bone, gills, and muscle of the seven fish species sampled during normal and dry seasons. Cadmium, Cu, and Pb concentrations varied significantly depending on the type of the tissue and season. Bone samples of the Osteochilus hasseltii showed the highest concentrations of Pb (6.08 μg/g dw) during September (the dry season), whereas bone samples of the Puntioplites bulu showed the lowest concentrations of Cd (0.08 μg/g dw) during September. Muscle samples of the P. bulu indicated the highest concentrations of Cu (2.58 μg/g dw) during March (the normal season). On the other hand, muscle samples of Channa straitus sowed the lowest concentrations of Cd (0.04 μg/g dw) during July (the dry season). Gills samples of the O. hasseltii showed the highest concentration of Pb (6.56 μg/g dw) during March (the normal season), while gills samples of C. straitus indicated the lowest concentration of Cd (0.06 μg/g dw) during July (the dry season). 相似文献
11.
《四川动物》2017,(2)
运用形态学比较和12S mt DNA序列比对,对华东4省原记载的花臭蛙Odorrana schmackeri地理种群与天目臭蛙O.tianmuii、黄岗臭蛙O.huanggangensis及花臭蛙模式产地湖北宜昌种群进行比较研究。浙江、安徽、江苏、江西(三清山)花臭蛙形态学特征与天目臭蛙相吻合。基于Kimura 2-parameter模型计算花臭蛙各地理种群与天目臭蛙、黄岗臭蛙及花臭蛙湖北宜昌种群的遗传距离,结果显示,浙江、安徽、江苏、江西(三清山、彭泽)花臭蛙与湖北宜昌种群的遗传距离为0.067~0.069,与黄岗臭蛙的遗传距离为0.027~0.029,与天目臭蛙的遗传距离仅为0~0.001。因此,长江中下游以南、江南丘陵东段安徽南部、江苏、浙江、江西东北部信江以北、鄱阳湖以东的低山丘陵地带,原记录的花臭蛙应修订为天目臭蛙;江西省东北部信江以南的武夷山区为黄岗臭蛙分布范围,花臭蛙则分布于赣江鄱阳湖以西的赣西山地。赣江以东、抚河以西以及闽东丘陵地区花臭蛙的分类归属尚待确定,华东地区花臭蛙复合体的物种分化是否与水系造成的地理阻隔相关,有待深入研究。 相似文献
12.
Farzin L Amiri M Shams H Ahmadi Faghih MA Moassesi ME 《Biological trace element research》2008,123(1-3):14-26
Monitoring of toxic trace elements for human blood has been of interest to researchers in the fields of environmental chemistry and medical science. The amount of blood toxic elements can reflect the disease state of the person or the environment where that person resides or works. Chronic, low-level exposure to toxic metals such as lead (Pb), cadmium (Cd), and mercury (Hg) is an increasing global problem. This study focuses on obtaining the usual value of Pb, Cd, and Hg in normal human blood. These elements were determined in 61 male and 40 female volunteers resident in Tehran (Iran). The subjects were non-drug abusers and aged 6-62 years old. Procedures were developed for the collection, storage, and preanalytical treatment of samples. The lead and cadmium were determined by graphite furnace atomic absorption spectrometry, and mercury was measured by cold vapor atomic absorption spectrometry technique. The blood levels of Pb, Cd, and Hg in normal volunteers living in Tehran were 123.75 +/- 56.42, 1.82 +/- 0.67, and 8.48 +/- 4.42 microg/L. There was no significant gender-related difference in blood Cd and Hg concentrations (p < 0.06 and p < 0.41). However, the results indicated significantly higher content of Pb in blood of males compared to females (138.11 +/- 65.43 and 101.84 +/- 51.38 microg/L, respectively, p < 0.05). 相似文献
13.
Seed germination is tolerant to heavy metals apparently because the seed coat is impermeable to metal ions. However, it is not clear whether the seed coat is a universal barrier for all metals. In addition, depending on their physical and chemical properties, a distribution of various metals may differ within an imbibing caryopsis, and therefore they produce dissimilar effects on seed germination. The toxic effects of Cd(NO3)2, Pb(NO3)2, Ni(NO3)2, and Sr(NO3)2 were estimated from the germination rates of maize (Zea mays L.) caryopses following two-day incubation with these salts. The distribution of heavy metals and Sr was studied by histochemical methods based on the formation of colored complexes with dithizone (Cd and Pb), dimethylglyoxyme (Ni), and sodium rhodizonate (Sr). Although the metals under study did not affect maize radicle protrusion, they inhibited seed germination in the following order: Cd > Ni ≈ Pb > Sr. Cd and Pb accumulated mainly in the seed coat cells, but Sr and Ni in the embryo cells and in the cells of endosperm (Sr) and scutellum (Ni). Although Cd was found only in the seed coat, it was the strongest inhibitor of seed germination. Apparently, due to high toxicity, Cd exerted its inhibitory effect at the concentrations too low for histochemical assay. In spite of easy translocation across the seed coat of imbibing caryopses, Sr did not considerably inhibit radicle protrusion and seed germination, apparently because of its low toxicity and predominant localization in the apoplast of embryo and endosperm cells.__________Translated from Fiziologiya Rastenii, Vol. 52, No. 4, 2005, pp. 635–640.Original Russian Text Copyright © 2005 by Seregin, Kozhevnikova. 相似文献
14.
15.
稻水象甲在浙江和福建省扩散的空间格局分析 总被引:2,自引:1,他引:2
应用地统计学方法和GIS技术分析了稻水象甲在浙江和福建省早稻上的空间分布和动态(1993-2001)。结果表明:稻水象甲主要分布于沿海一带,其空间分布格局在所有年份均表现为聚集分布,并且这种分布格局随时间发生变化。在1993年该虫入侵面积大约为392100公顷,在以后的几年中其面积随时间而持续增加,至2001年达最大,为2533900公顷。稻水象甲起初沿海岸线向南扩散,接着向北,现在该虫已入侵约26个县和190个乡镇。通常,该虫在南部的为害重于北部,玉环、乐清、温岭等地发生最重。稻水象甲主要沿公路和水路扩散,这表明该虫的传播为人类活动所致,因此其扩散速率可以通过对国家和地区间的交通货运进行严格的检疫而得到控制。 相似文献
16.
Aneta Unkiewicz-Winiarczyk Kazimiera Gromysz-Kałkowska Ewa Szubartowska 《Biological trace element research》2009,132(1-3):41-50
In the research, the contents of heavy metals, Al, Cd and Pb, in the hair of individuals who reside in similar environmental conditions were spectrometrically determined with the use of atomic emission spectrometry–inductively coupled plasma spectrophotometer. The relation to their tobacco smoking habit, age and sex was established. It was observed that the level of all three determined elements was generally higher in the hair of smokers in comparison to hair of non-smokers in both younger and older age groups. In addition, it has been observed that, in the group of elderly people over 50 years old, there was an increase in the content of aluminium, cadmium and lead both in smokers and non-smokers, irrespective of their sex. The sex-related differences in the content of the investigated elements were not unidirectional, and only in few cases did they reveal statistical significance. 相似文献
17.
The new QUAFIT method for determining the quaternary structure of biological macromolecular assemblies by analyzing x-ray or neutron small-angle scattering data is presented. The method is based on the idea that asymmetric monomers, formed by rigid domains of known atomic structure possibly connected by flexible linkers of known sequence, are assembled according to a point-group symmetry combined with a screw axis. Scattering amplitudes of domains and linkers are determined by means of a spherical harmonics expansion and combined to get the form factor of the assembly. To avoid any overlap among domains, the contact distance between two asymmetric domains is determined as a function of their orientation by a new algorithm, based on Stone's Invariants expansion. To account for continuity and compactness of the whole assembly, an anisotropic Lennard-Jones potential among domains, written in terms of the contact distances, is included in the merit function. QUAFIT allows for the simultaneous presence of oligomerization intermediates as well as of monomers distributed over multiple conformations. QUAFIT has been tested by studying the structure of a high molecular weight protein, the hemocyanin from Octopus vulgaris, under solution conditions that stabilize the decameric form or induce dissociation into monomers, respectively. Results are in very good agreement with the structural model derived from electron microscopy observations. 相似文献
18.
Cai Y 《Biological trace element research》2011,144(1-3):469-474
Select trace elements (Fe, Cu, Zn, Al, K, Na, Ba, Sb, Pb, As) were determined by ICP-AES after nitric acid-perchloric acid wet digestion in samples of scalp hair of University students. Some metal-to-metal intercorrelations were found. The more often the hair was dyed and marcelled, the higher were the contents of iron, copper, potassium, sodium, barium, lead, and arsenic. Copper levels increased with the degree of myopia, while zinc, lead, aluminum, iron, and potassium decreased with the myopic degree. Copper, zinc, iron, and arsenic levels were lower in white hair, while sodium and lead were higher. The levels of the elements were generally higher in the hair samples of students who drink and smoke. The hair metal contents were found to be influenced by alcohol use and smoking. Hair element analyses thus could be used as noninvasive means of detecting unhealthy lifestyles in college students. 相似文献
19.
Feng Li Xiang-yun Zeng Chang-hua Wu Zhi-peng Duan Yan-mao Wen Guo-ru Huang Xiao-lin Long Min-Jian Li Man-Jie Li Jiang-Yu Xu 《Biological trace element research》2013,155(2):301-313
Sediments from 14 stations in the Foshan Waterway, a river crossing the industrial district of Guangdong Province, South China, were sampled and subsequently analyzed. The 14 stations were selected for the pollution discharging features of the river, such as the hydrology, the distribution of pollution sources, and the locations of wastewater outlets. The ecological risks were assessed, and the pollution sources were identified to provide valuable information for environmental impact assessment and pollution control. The spatial variability was high and the range were (in milligrams per kilogram dry weight): Pb, 46.0~382.8; Cu, 33.7~ 482.3; Zn, 62.2~1,568.7; Ni, 28.5~130.7; Cr, 34.7~1,656.1; Cd, 0.50~8.53; Hg, 0.02~8.27; and As, 5.77~66.09. The evaluation results of enrichment factor and potential ecological risk index indicate that the metal pollution in the surface and bottom sediments were severely polluted and could pose serious threat to the ecosystem in most stations. Although the hazard levels of the trace element differed among the stations, Hg was the most serious pollutant in all stations. The results of principal component analysis (PCA) show that the discharge of industrial wastewater is the most important polluting factor whereas domestic sewage, which contains a large amount of organic substances, accelerates metal deposition. And potential pollution sources were identified by the way of integrating the analysis results of PCA and data gained from the local government. Therefore, the conclusion is drawn that Foshan Waterway is seriously polluted with trace elements, both in the surface sediment (0 to 20 cm) and the bottom sediments (21 to 50 cm) are contaminated. 相似文献