汉江水体和沉积物中全氟化合物的风险评估

采集汉江旱季和雨季的水样和沉积物,应用超高效液相色谱–三重四级杆质谱,对其中的11种全氟化合物(PFCs)进行检测,研究该区域全氟化合物的污染状况。结果表明,11种全氟化合物都有不同程度的检出,旱季和雨季水样中∑PFCs浓度分别为0.3~23.04和0.16~19.68 ng/L,沉积物中∑PFCs浓度分别为0~55.1和0.99~85.07 ng/g。水样总浓度的最高值出现在汉江汇入长江处的武汉,且武汉采样点的全氟辛酸(PFOA)浓度最高,旱、雨季分别达到22.52和12.52 ng/L。沉积物中总浓度最高值出现在陶岔,且以全氟庚酸(PFHp A)和全氟己酸(PFHx A)为主,沉积物中组分组成的季节差异不大。采用实际检测到的水样中PFOA、全氟辛烷磺酸盐(PFOS)、全氟壬酸(PFNA)、PFHx A和全氟葵酸(PFDA)的浓度以及沉积物中PFOA和PFOS的浓度,运用熵值法,对汉江流域进行全氟化合物污染的风险评估,结果表明,水体和沉积物中的浓度均未达到对生态环境具有风险的水平。     

Perfluorooctane sulfonate （PFOS） and related fluorochemicals in chicken egg in China

The ubiquitous occurrence of perfluorinated compounds （PFCs） in environmental samples has drawn much attention. Recent human exposure studies found relatively high perfluorooctane sulfonate （PFOS） concentrations in blood samples from several cities in China when compared with other countries. The objectives of the present study were： （1） to measure PFC concentrations and compositions in chicken egg samples from local markets in China; and （2） to conduct a preliminary human health risk assessment of egg consumption. Eight pooled egg samples from eight locations were analyzed for 11 PFCs. The results showed that close to 100% of the PFOS in the egg was distributed in egg yolk and PFOS was not detected in egg white （〈0.08 ng/g wet weight, w/w）. Of the perfluoroalkylsulfonates, only PFOS was detected in all egg samples, while of the perfluoroalkylcarboxylates, perfluoroundecanoic acid （PFUnDA） was detected in all samples, followed by perfluorooctanoate （PFOA） （75% occurrence） and perfluorodecanoic acid （PFDA） （50% occurrence）. PFOS concentrations in egg ranged from 45.0 to 86.9 ng/g w/w. The results suggested that current concentrations of PFOS in domestic chicken eggs are unlikely to cause immediate harm to Chinese populations.     

Perfluorooctane sulfonate (PFOS) and other fluorochemicals in viscera and muscle of farmed pigs and chickens in Beijing,China

Eleven perfluorinated compounds (PFCs) were determined in tissue samples from farmed pigs and chickens (n=143) that were purchased in Beijing in March 2009. The total PFCs mean concentration was the highest in pig liver (3.438 ng g^–1 wet weight (ww)), followed by pig kidney (0.508 ng g^–1 (ww)), pig heart (0.167 ng g^–1 (ww)), chicken liver (0.098 ng g^–1 (ww)), chicken heart (0.050 ng g^–1 (ww)), pork loin (0.018 ng g^–1 (ww)), and chicken breast (0.012 ng g^–1 (ww)). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) was the predominant compound in viscera and muscle of farmed pigs and chickens. In addition, a strong linear correlation (r = 0.932) was observed between the concentrations of PFOS and perfluoroundecanoic acid (PFUnDA) in pig liver. Our preliminary conclusion is that there is little potential risk of exposure to PFCs via the consumption of these products in Beijing.     

Electrochemically enhanced adsorption of PFOA and PFOS on multiwalled carbon nanotubes in continuous flow mode

It is important to develop efficient technologies on removal of perfluorooctanoic acid （PFOA） and perfluorooctane sulfonate （PFOS） from water due to their wide distribution and potential threat to human health. In this work, a durable and convenient electrosorption device was designed in continuous flow mode to investigate the adsorption of PFOX （X = A and S） on multiwalled carbon nanotubes （MWNTs） from water under electrochemical assistance. The electrosorption experiments were conducted under different influent and electrolyte concentrations, hydraulic retention time （HRT） and electrode distance to optimize the operation. The results showed that the highest removal efficiencies toward both PFOA and PFOS could come up to 90 % at 1 V. Compared with open circuit （OC） adsorption under the same conditions, the removal efficiencies were improved by 4.9 times （PFOA） and 4.2 times （PFOS） respectively. In addition, the MWNTs electrode was found to be reusable. These findings provide an efficient method to remove PFOX from water by electrosorption in continuous flow mode.     

Perfluoroalkyl substances in the blood samples from a male population of Sweden

Temporal trends of perfluoroalkyl substances （PFASs） have been determined in the blood samples from several countries globally including a female population in Sweden recently, yet little is known about the time trends in the blood levels of these compounds in Swedish male populations over recent years. In this study, the fourteen target PFASs consisted of four perfluorosulfonates （PFSAs） and ten perfluorocarboxylates （PFCAs） in the whole blood samples, collected from 153 Swedish elderly men during the period between 2008 and 2010, were analyzed via ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. As the dominant PFASs contaminants in the blood samples, perfluorooctane sulfo- nate （PFOS） showed the highest geometric mean （GM） at 8.5 ng/mL, ranging from 1.7 to 29 ng/mL, while blood perfluorooctanoic acid （PFOA） contained the GM of 1.8 ng/mL, ranging from 0.35 to 6.4 ng/mL. Both the levels of these two compounds were lower than those determined in the blood samples of Swedish elderly pop- ulations derived from the late 1990s. According to the temporal trend analysis, over the three years, the blood levels of PFOS in Swedish male populations declined 16 % per annum, while those of perfluoroundecanoic acid （PFUnDA） increased 6.1% per annum, which were con- sistent with those reported previously for the populations from other countries.     

Occurrence of perfluoroalkyl acids in precipitation from Shenyang, China

Perfluorosulfonates （PFSAs） and perfluorocarboxylates （PFCAs） in precipitation collected from Shenyang, China were determined. Snow samples were collected in the snow event on March 4, 2007 from 34 sites involving both the urban and suburban areas in Shenyang. The snowmelt was preconcentrated by solid phase extraction and analyzed using LC-MS method. Measurable amounts of perfluoroalkyl acids （PFAS） were found in precipitation samples from Shenyang, demonstrating that wet deposition is one possible pathway for the removing of the selected PFAS chemicals from atmosphere. Major PFAS detected were PFOS （〈0.38-51 ng/L）, PFOA （0.82-13 ng/L） and PFHpA （0.76-11 ng/L）, with their mean concentration of 5.4, 3.3 and 2.9 ng/L, respectively. Other PFSAs and PFCAs were detected at much lower frequency or below the limit of detection in all the samples. The work presented here offers some basis for the investigation on the environmental behavior and the evaluation of human exposure to PFAS.     

快速城市化流域全氟化合物的污染特征及生态风险

为探究快速城市化地区城市河流中全氟化合物(PFCs)的污染特征, 于枯水期和丰水期分别采集深圳市观澜河干流的表层水样, 通过固相萃取法处理水样, 并利用超高效液相色谱–三重四级杆串联质谱(UPLCESI-MS/MS)技术分析 11 种PFCs的含量。结果表明, 丰水期和枯水期观澜河干流水体中PFCs的含量分别为179.15~613.68和37.04~103.70 ng/L。其中, 全氟己烷磺酸(PFHxS)、全氟丁烷磺酸(PFBS)、全氟己酸(PFHxA)和全氟辛酸(PFOA)是主要污染物。所采集的样品中, 丰水期PFCs的浓度高于枯水期, 下游采样点PFCs的浓度高于上中游河段。与已报道的其他水体相比, 由于流域的快速城市化, 观澜河水体的PFCs含量水平较高。生态风险评估表明, 水体中检出的PFCs均不会对水体造成生态风险。     

Distribution and risk factors of hand,foot, and mouth disease in Changchun,northeastern China

Hand, foot, and mouth disease (HFMD) is a public health problem, and there have been increasing numbers of outbreaks in mainland China since 2008. Over 17,000 HFMD cases have been reported in Changchun between 2008 and 2011. This study characterized the temporal and spatial distribution of the disease and identified the risk factors for HFMD. The main findings were as follows: (i) there were significant differences in HFMD incidence among age groups, with 86.8 % of reported cases in children younger than 5 years old, and boys showed a higher incidence than girls (<6 years); (ii) The disease affected the whole region and spanned a large geographic area, but there was a higher incidence in urban areas (median = 242 per 10,000 persons) and urban–rural border areas (median = 135 per 10,000 persons), compared with rural areas (median = 75 per 10,000 persons); and (iii) the incidence of HFMD in Changchun was significantly associated with the distance to the nearest freeway, GDP per capita, and the type of township.     

Scattered Rural Settlements and Development of Mountainous Regions in Western Sichuan, China

Making rural settlements of Mountainous Regions in Western Sichuan as the study objects and using symbolic statistical methods, then combining the case study of Daofu County, the paper analyzes the negative impact of the scattered rural settlements on infrastructure construction, farmers＇ income increase and mountain ecological reconstruction in mountainous regions of western Sichuan. The results indicate that economic density is positively related to both rural settlements density （R^2=0.73） and rural population density （R^2=0.77）, and it is the same for relationship between towns density and rural settlements density （R^2=0.88） and between towns density and economic density （R^2=0.71）, and the scattered distribution pattern of the rural settlements and shortage of economic centers is a major factor to the lagged socioeconomic development. On the eco-economic zoning to Daofu County, the paper indicates the spatial distribution model and the industrial development model of the rural settlements need to be changed, and rural population should be concentrated in larger rural settlements with development of off-farm industries while infrastructure construction is to reinforced.     

Calculation method of electronic structure and its application to (I h andI) fullerenes

A new calculation method was discussed to treat the Hückel Hamiltonian of any fullerene with a certain point group symmetry. This method was applied to calculating the electronic energy levels of icosahedral fullerenes C\-n(I\-h: n=60h 2, 0相似文献   

Methods and Effects of Hongshan Cock Spermatozoa Cryopreservation

0Introduction Afterthecarryingoutofopen doorpolicies,espe ciallyinthelatesttenyears,livestockandpoul try’sraisingbusinessdevelopedveryfastinChina,whichhelpeduscompletelyshrugofftheembarrassed situationofsevereshortagesofanimalproteininthepastlongperiodandgreatlyexcitedandencouraged us.Meanwhilewemustclearlyrealizethepotentialdangersbehindthepresentprosperities.Ourbreeds arebecominglessandless,manynativebreedswithlowperformancedisappearedcompletely,thetendency oftheirextinctionisincreasinginth…     

The fourier transformations of positive distributions on lorentz groupSO (3, 1)

With the aid of Plancherel-Godement Theorem, we prove that every positive distributionT onSO (3, 1) which is bi-invariant underSO(3) corresponds to a measure μ on ω=∝σC|s(2-s)>=0∝, and μ can be decomposed intoμ=μ ₁+μ ₂, whereμ ₁ is a bounded measure on 0<=s<=2 andμ ₂ is slowly increasing measure on (sχC|Re(s)=1)} Foundation item: Supported by the National Natural Science Foundation of China (19871065) and Hua Cheng Mathematics Science Foundation. Biography: Zhu Li (1976-), male, Graduate student, research interest: partial differential equation     

Seasonal variation and sources of low molecular weight organic acids in precipitation in the rural area of Anshun

Low molecular weight (LMW) organic acids are important and ubiquitous chemical constituents in the atmosphere. A comprehensive study of the chemical composition of precipitation was carried out from June 2007 to June 2008 at a rural site in Anshun, in the west of Guizhou Province, China. During this period, 118 rainwater samples were collected and the main LMW carboxylic acids were determined using ion chromatography. The average pH of rainwater was 4.89 which is a typical acidic value. The most abundant carboxylic acids were formic acid (volume weight mean concentration: 8.77 μmol L⁻¹) and acetic acid (6.90 μmol L⁻¹), followed by oxalic acid (2.05 μmol L⁻¹). The seasonal variation of concentrations and wet deposition fluxes of organic acids indicated that direct vegetation emissions were the main sources of the organic acids. Highest concentrations were observed in winter and were ascribed to the low winter rainfall and the contribution of other air pollution sources northeast of the study area. The ratio of formic and acetic acids in the precipitation ([F/A] _T ) was proposed as an indicator of pollution source. This suggested that the pollution resulted from direct emissions from natural or anthropogenic sources. Comparison with acid precipitation in other urban and rural areas in Guizhou showed that there was a decreasing contribution of LMW organic acids to free acidity and all anions in rainwater from urban to remote rural areas. Consequently, it is necessary to control emissions of organic acids to reduce the frequency of acid rain, especially in rural and remote areas.     

全氟辛烷磺酸对大型蚤的慢性毒性研究

采用大型蚤21天暴露和子代21天恢复实验法,研究了PFOS对大型蚤的慢性毒性效应及其子代F1(1st)和F1(3rd)的恢复情况。结果显示:PFOS质量浓度高于20mg/L时,F0代总产卵量、终点体长和内禀增长率都受到显著抑制。3个指标在最高浓度组与空白组相比,依次降低了62.2%,40.6%,34.0%(p<0.01)。随PFOS暴露浓度增加,其对大型蚤毒性逐渐加重,PFOS暴露浓度与对大型蚤毒性之间具有明显的剂量-效应关系。当PFOS质量浓度高于30mg/L时,F1(lst)代总产卵量和终点体长受到显著抑制。F1(3rd)代比F1(1st)代大型蚤恢复程度更好,除暴露于50mg/L的总产卵量、终点体长和内禀增长率仍受显著抑制,其他指标都恢复到接近空白组水平。大型蚤总产卵量、终点体长和内禀增长率作为最敏感的指标,建议将其用于评价PFOS的慢性毒性。     

葎草抗炎镇痛有效部位筛选及机制

目的 筛选葎草镇痛抗炎的有效部位，初步探讨有效部位镇痛抗炎的作用机制。方法 采用溶剂萃取法将葎草水提液分离为不同部位；采用小鼠热板和醋酸扭体疼痛模型，筛选葎草镇痛作用的有效部位；采用二甲苯小鼠耳肿胀、大鼠蛋清足跖肿胀2种急性炎症模型以及大鼠棉球肉芽肿慢性炎症模型，筛选葎草抗炎作用的有效部位；检测有效部位对醋酸所致疼痛模型小鼠血清前列腺素E₂（PGE₂）、环磷酸腺苷（cAMP）含量以及蛋清所致大鼠足跖炎症组织NO和PGE₂含量的影响。结果 葎草石油醚萃取部位明显延长热板所致小鼠的痛阈值（P < 0.05），明显减少醋酸所致小鼠扭体反应次数（P < 0.05）；葎草石油醚萃取部位明显抑制二甲苯所致小鼠耳廓肿胀（P < 0.05），明显抑制蛋清所致大鼠足跖肿胀和大鼠棉球肉芽肿（P < 0.05）。葎草石油醚萃取部位明显降低醋酸所致疼痛小鼠血清PGE₂、cAMP的含量（P < 0.05），明显降低蛋清所致大鼠足跖组织NO和PGE₂含量（P < 0.05）。结论 葎草的水提液的石油醚萃取部位是镇痛抗炎的有效部位，其镇痛作用机制可能与降低PGE₂、cAMP的含量有关，其抗炎作用机制可能与减少炎症组织NO和PGE₂含量有关。     

三聚磷酸二氢铝二水物的合成和表征

用磷酸和氢氧化铝为原料制备三聚磷酸二氢铝二水物。用X-衍射、红外光谱、化学分析、DTA-TG结合X-ray分析,证明产品的化学结构式为AlH2P3O10*2H2O。其晶体结构属正交晶系,空间群为PZ1/bZ1/aZ/m,D92h,晶胞参数a=15.919×10-8 cm,b=8.884×10-8cm,c=9.936×10-8 cm,单位晶胞体积V=1 405×10-8 cm3,Z=6。防绣性能测试表明其防锈能力与红丹颜料相当。毒理学试验表明该颜料半致死量LD50=18.0 g/kg(小白鼠),属实际无毒级,符合食品容器及儿童玩具涂装的要求。     

Increasing prevalence of asthma and allergy in Beijing pre-school children: Is exclusive breastfeeding for more than 6 months protective?

This study evaluated the prevalence and risk factors for asthma, allergy and related symptoms; and breastfeeding patterns and durations for 5479 Beijing children aged 3–6. Parents of children in randomly selected kindergartens wrote responses to a questionnaire used previously. The study aimed to evaluate trends in the prevalence of asthma and related illnesses, and to determine whether “more” breastfeeding, defined as exclusive, > 6 months, was associated with reduced prevalence. Asthma has increased in this age group between 1990 and 2011, with the steepest increase in the last 2–3 years. Of the total, 14.2% (779) children were breastfed exclusively for > 6 months. The efficacy of “more” breastfeeding was tested in a subset with two strong risk factors, positive family history (for asthma and/or allergy) and male gender. “More” breastfeeding was found to be significantly protective (aOR 0.42, P < 0.05) for this subset against Doctor-diagnosed asthma (D-asthma). Protection that did not reach statistical significance was also found for this subset against Wheeze ever, Cough at night, Rhinitis ever, Doctor-diagnosed rhinitis (D-rhinitis) and Eczema. The greatest protective effects were found for girls with no family history of asthma or allergy, reaching statistical significance for Wheeze ever (aOR 0.48, P < 0.01), Cough at night (aOR 0.47, P < 0.01), D-asthma (aOR 0.14, P < 0.01) and Rhinitis ever (aOR 0.67, P < 0.05). “More” breastfeeding was not consistently associated with either a protective or risk effect for Eczema.     

中国城乡恩格尔系数差异度的灰色建模与预测

为了提高预测精度,利用灰色GM （1,1）预测模型对中国城乡居民恩格尔系数差异度的变动趋势进行实证研究,并利用残差灰色预测模型对原始GM （1,1）模型进行修正。修正结果表明,残差修正后的GM （1,1）模型预测精度有显著提高。同时,中国在经历了二元经济结构后,目前整体上已经达到了城乡一体化,城乡居民生活质量基本一致的状态。     

铁苋菜抗炎镇痛有效部位的筛选

目的 筛选铁苋菜抗炎镇痛作用的有效部位,并初步探究其作用机制.方法 采用热板和醋酸扭体疼痛模型,考察铁苋菜镇痛作用的有效部位,采用二甲苯致小鼠耳肿胀、蛋清致大鼠足跖肿胀以及大鼠棉球肉芽肿炎症模型,考察铁苋菜抗炎作用的有效部位.结果 铁苋菜乙酸乙酯萃取部位明显延长热板所致小鼠痛阈值和明显减少醋酸所致小鼠扭体反应次数,与正...     

Cardiac protective role of a novel erythrocyte-derived depressing factor on rats and its Ca^2＋ mechanism

The cardiac protective role of a novel erythro-cyte-derived depressing factor (EDDF) on spontaneous hy-pertensive rats (SHR), calcium overload (CaO) rats and Wistar rats and its mechanism was evaluated. Mean artery pressure (MAP), heart rate (HR) and LVdp/dtmax were measured by physiological recorder. The effect of EDDF on the Ca2+-ATPase activity in myocardial sarcoplasmic reticu-lum (SR) of CaO rats was determined by inorganic phos-phate assay. Calcium transport in myocytes was measured by 45Ca2+ radioactive isotope measurement. The phosphoryla-tion levels of extracellular signal-regulated protein kinases (ERK1/2) in myocardial tissue of SHR and CaO rats were measured by Western blot method. And the ultrastructures of cardiac muscle cells were observed with the transmission electron microscope. The results indicated that EDDF could significantly decrease MAP, HR and LVdp/dtmax in a dose dependent manner (P < 0.05). It seems that the mechanism might relate with activating the Ca2+-APTase, enhancing the uptake and release of Ca2+ from SR (P < 0.05), decreasing the phosphorylation levels of ERK1/2 of myocytes (P < 0.01) and lightening the ultrastructural lesion of cardiac muscle cells. In CaO rats, the Ca2+-ATPase activity decreased clearly com-pared to control (64.99 7.16 vs 94.48 7.68 nmol·min-1 ·mg-1 protein, P < 0.01), while EDDF (100 mg/mL) could significantly increase the activity (87.93 ?9.54 vs 64.99 ?7.16, P < 0.05, n = 7). Both uptake and release rate of Ca2+ (祄ol 45Ca2+/g protein/min) from myocardial SR of CaO rats re-markably decreased compared to control (32.40 ?2.70 and 15.46 ?1.49 vs 61.09 ?10.89 and 25.47 ?4.29, P < 0.05); EDDF (100 mg/mL) could significantly stimulate their activi-ties (50.48 6.76 and 21.76 2.75 vs 32.40 2.70 and 15.46 1.49, P < 0.05). EDDF could evidently down-regulate the phosphorylation of ERK1/2 in myocardial tissue from SHR and CaO rats (P < 0.01), lighten the ultrastructural lesion of cardiac muscle cells of SHR as well. It is concluded that EDDF seems to play protective roles on both structure and function of heart, which closely related with amelioration of Ca2+ transport and inhibition of Ca2+-MAP kinase pathway.