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.     

Perfluorooctane sulfonate and perfluorooctanoic acid in the fingernails of urban and rural children

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are two typical perfluorinated compounds (PFCs), found in a wide range of environmental media and organisms, including humans. Human biomonitoring studies of body fluids have revealed that in many areas of the world the general population has been exposed to background levels of PFOS and PFOA. Fingernail has been suggested as a promising biopsy material for assessment of PFCs environmental exposure. In the present study, PFOS and PFOA were quantified using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in fingernails of urban and rural children (N=93) aged 6–12 years. A questionnaire was conducted to determine factors that could influence the PFOS and PFOA levels in the children. The levels of PFOS in urban children were significantly higher (geometric mean (GM)=328 ng/g) than those in rural children (GM=27 ng/g). In contrast, PFOA levels were significantly lower in the urban children compared with the rural children. Significant positive correlation (R=0.53, P<0.05 for urban areas; R=0.71; P<0.001 for rural areas) between the PFOS and PFOA concentrations indicated they had similar sources. The PFOS and PFOA levels were higher in fingernail samples from children aged <9 years than in children aged ⩾9 years. In addition, females had higher PFOA levels than males, in both regions. Other factors that significantly influenced PFOS and PFOA levels were dietary habits and socio-economic background. The results of this study indicate fingernails are a suitable material for biomonitoring of PFCs environmental exposure. However, the levels determined in the fingernail samples need to be first evaluated with regard to the levels determined in other samples, such as human serum.     

黄河下游水体中全氟及多氟烷基化合物的分布特征

系统地研究黄河下游春秋两季水样和沉积物中50种PFASs的分布特征和生态风险。结果表明, PFASs在春秋两季水样中检出的总浓度范围分别为29.83~54.44和16.18~57.81 ng/L, 春秋两季沉积物中PFASs的含量范围分别为18.12~36.16和13.01~36.78 ng/g。在春秋两季占比最高的3类物质在水相和沉积物中均为全氟烷基羧酸(PFCAs)、全氟烷基磺酸(PFSAs)和n:2氟调聚磺酸(n:2 FTSs)。作为新型PFASs, n:2 FTSs在水相和沉积物中均有较高的检出水平。全氟辛酸(PFOA)在水相和沉积物中的主要替代物为短链PFCAs, 六氟环氧丙烷二聚酸(HFPO-DA)则在沉积物中对PFOA有更高的替代趋势; 全氟辛烷磺酸(PFOS)在水相和沉积物中的主要替代物为6:2 FTS。风险熵值法分析结果表明, 水体中各PFASs目标物均未达到环境生态风险水平。     

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.     

Biological correlates of psychological states among young children: a cross-sectional examination of roles of aspartate transaminase/alanine aminotransferase,insulin, and cytokines

Compared to data on adolescents and adults, limited research has been conducted on biological corre- lates among young children with possible psychological difficulties, especially in Asian countries. By focusing on various peripheral biochemical indicators, we investigated potential biological correlates of psychological states in a community sample of Taiwanese school children aged 6-10 years. In total, 307 students （159 obese children and 148 normal-weight children） were selected from first- and fourth-grade school children in eight elementary schools in the Taipei metropolitan area in 2009. These children underwent a comprehensive health examination, including a physical examination, blood sample analysis, and questionnaire administration in a hospital. Differences in anthropometric and serum biochemical readings were compared between children with average and worse levels on each of the five psychological domains. We found that interleukin （IL）-1β [β = 1.29, 95 % confidence interval （CI） 0.50-2.09], IL-10 （β = 1.61, 95 % CI 〈0.01-3.24）, fasting blood glucose （β = 0.08, 95 % CI 0.01-0.15）, homocysteine （β = 0.63, 95 % CI 0.09-1.18）, and aspar- tate transaminase （AST） （β = 0.15, 95 % CI 〈0.01-0.31） were significantly positively associated with anxiety. In addition, IL-113, insulin, AST, and alanine aminotransam- inase （ALT） were significantly positively associated with depression. Anger and disruptive behaviors were also related to specific biological correlates. Specific biological correlates, including AST/ALT, cardiovascular disease- related variables, and specific cytokines, were linked to particular psychological states among young children in this Asian population. These might provide a route for better understanding the biological aspects of children＇s mental health and might contribute to research on diag- nostic or predictive biomarkers for psychiatric diseases in young children.     

Single-trial decoding of imagined grip force parameters involving the right or left hand based on movement-related cortical potentials

Time–domain feature representation for imagined grip force movement-related cortical potentials(MRCP)of the right or left hand and the decoding of imagined grip force parameters based on electroencephalogram(EEG)activity recorded during a single trial were here investigated.EEG signals were acquired from eleven healthy subjects during four different imagined tasks performed with the right or left hand.Subjects were instructed to execute imagined grip movement at two different levels of force.Each task was executed 60 times in random order.The imagined grip force MRCP of the right or left hand was analyzed by superposition and averaging technology,a single-trial extraction method,analysis of variance(ANOVA),and multiple comparisons.Significantly different features were observed among different imagined grip force tasks.These differences were used to decode imagined grip force parameters using Fisher linear discrimination analysis based on kernel function(k-FLDA)and support vector machine(SVM).Under the proposed experimental paradigm,the study showed that MRCP may characterize the dynamic processing that takes place in the brain during the planning,execution,and precision of a given imagined grip force task.This means that features related to MRCP can be used to decode imagined grip force parameters based on EEG.ANOVA and multiple comparisons of time–domain features for MRCP showed that movement-monitoring potentials(MMP)and specific interval(0–150 ms)average potentials to be significantly different among 4 different imagined grip force tasks.The minimum peak negativity differed significantly between high and low amplitude grip force.Identification of the 4different imagined grip force tasks based on MMP was performed using k-FLDA and SVM,and the average misclassification rates of 27%±5%and 24%±4%across 11 subjects were achieved respectively.The minimum misclassification rate was 15%,and the average minimum misclassification rate across 11 subjects was24%±4.5%.This investigation indicates that imagined grip force MRCP may encode imagined grip force parameters.Single-trial decoding of imagined grip force parameters based on MRCP may be feasible.The study may provide some additional and fine control instructions for brain–computer interfaces.     

Meta-Analysis on the associations between Prenatal Perfluoroalkyl Substances Exposure and Adverse Birth Outcomes

The epidemiological associations between the prenatal perfluoroalkyl substances(PFASs) exposure and the reproductive outcomes remain controversial. A continuous evaluation is needed to combine the inconsistent results. In this study, we explored the associations between PFASs exposure and the low birth weight(LBW), preterm birth and small for gestational age(SGA). The quality of selected literature, quantitative estimates, publication bias and subgroup analysis were performed on the basis of 17 retrieved articles published before December 2020. The results showed a significant positive association between the perfluorooctane sulfonate(PFOS) exposure and the risk of LBW [Odds ratio(OR)=1.17; 95% confidence interval(CI): 1.01, 1.36; heterogeneity: P=0.30, I~2=17%]. The positive association was also observed between the PFOS and the risk of preterm birth(OR=1.19; 95% CI: 1.01, 1.39, P=0.007; I~2=62%). There was a paucity of evidence regarding the negative effects of perfluorooctanoic acid(PFOA), perfluorohexanesulfonic acid(PFHxS) and perfluorononanoic acid(PFNA) on the pregnancy outcomes. The findings from the subgroup analysis(the sampling period, the birth gender and biologic specimens) did not substantially altered the results of the overall pooled estimate ORs. The increased prevalence of negative birth outcomes with gestational PFASs exposure warrants further explorations from biological process perspective.     

Mirror image: newfangled cell-level layout technique for single-event transient mitigation

Recent years, the hardening of combinational circuits is becoming a common concern. Unlike the transistorlevel hardening technique, the celllevel hardening technique, a divide and conquer strategy, can substantially make use of some typical character in the cellcircuit module to mitigate single event transient （SET） sensitivity. The mirror image （MI） technique proposed in this paper can adequately enhance the charge sharing in those cell-circuits with stage-by-stage inverterlike structure. 3D TCAD mixed-mode simulation have been performed in 65 nm twinwell bulk CMOS process, the results indicate that the MI technique can almost reduce the SET pulse width from the anteriorstage PMOS over 25 %, and can mitigate the SET pulse width from the posteriorstage PMOS about 10 %. The MI technique, a represent of the cell-level technique, may be the future of the hardening of combinational circuits.     

肥胖低通气综合征患者血清瘦素水平的变化及意义

为了研究血清瘦素在肥胖低通气综合征(OHS)患者体内的变化及其意义,通过酶联免疫吸附测定(ELISA)法测定了所有受试者的血清瘦素水平,选取OHS组23例、肥胖OSA组40例、非肥胖OSA组14例、单纯肥胖组6例和正常对照组10例。比较所有受试者的一般资料、血清瘦素水平和多导睡眠参数,分析肥胖各组的血气分析结果。对瘦素与其他参数进行相关性分析,并分析其对OHS的诊断预测。结果表明OHS组BMI、颈围明显高于其他组。OHS组血清瘦素水平高于其他各组,且各组之间均存在明显差异(P 0.05)。血清瘦素水平与BMI、颈围、腰围、臀围、Pa CO_2、动脉血HCO_3~-呈正相关,与Pa O_2呈负相关。BMI、颈围、腰围和血清瘦素水平对OHS具有诊断预测作用。可见OHS组血清瘦素水平较肥胖OSA组、单纯肥胖组明显升高,除了肥胖因素外,OHS本身也可成为血清瘦素水平升高的原因,血清瘦素水平的升高可以作为OHS的诊断预测指标之一。     

溢乳症患者血清PRL含量测定的临床意义

目的探讨溢乳症患者血清中垂体泌乳素（Prolactin,PRL）含量检测的临床价值。方法采用PRL免疫化学发光检测法,对47例溢乳症患者（溢乳组）血清进行测定,并与正常哺乳期妇女（哺乳组）及非哺乳期健康妇女（正常组）进行对照比较。结果溢乳组与哺乳组血清PRL含量比较无显著性差异（t=1.077 7,P〉0.05）,但溢乳组的PRL异常率明显高于哺乳组（χ2=6.305 9,P〈0.01）,溢乳组和哺乳组血清PRL值均明显升高,与正常组比较均有显著性差异（t=6.201 6,P〈0.01 t=5.287 8,P〈0.01） 溢乳组血清PRL异常率均明显高于哺乳组和正常组（χ2=6.305 9,P〈0.01 χ2=13.315 9,P〈0.01）,而哺乳组和正常组的血清PRL异常率比较无明显差异（χ2=0.934 8,P〉0.05）。结论溢乳症患者血清中PRL值均呈病理性升高,但PRL异常率的诊断价值明显优于PRL的含量检测。     

Rapid denudation of the Himalayan orogen in the Nyalam area,southern Tibet,since the Pliocene and implications for tectonics–climate coupling

The Himalayan orogen characterized by very high variability in tectonic and climatic processes,and is thus regarded as a natural laboratory for investigating the coupling of tectonics and climate,as well as the influence of this coupling on geomorphological processes.This study uses apatite fission track(AFT)dating of samples from a45-km-long section crossing the Great Himalaya Crystalline Complex(GHC)in the Nyalam area,southern Tibet,to constrain the timing and rate of late Cenozoic denudation.The AFT ages can be divided into two groups:(1)15–6 Ma,to the north of Nyalam town,for which the bestfit line of elevation-age has a gentle slope of 0.05,and for which a denudation rate of 0.27 mm/a is calculated;and(2)3–1 Ma,south of Nyalam town,for which the best-fit line has a steep slope of 0.64,and for which a denudation rate of 1.32 mm/a is calculated.The whole AFT ages has a positive correlation with sample elevation(i.e.,older ages are found at higher elevations),and the geographical location of the point of inflexion of the two fitted lines corresponds closely to the junction of Poqu River near Nyalam town.By integrating the AFT data with thermotectonic modeling,it can be inferred that the GHC has experienced two different periods of denudation:(1)slow denudation during middle to late Miocene(15–6 Ma)is recorded in the northern part of the GHC;and(2)rapid denudation from the Pliocene to the Pleistocene(3–1 Ma)is recorded in the southern part of the GHC.An abrupt change in denudation rate occurred between the two periods,with the Pliocene–Pleistocene denudation rate being five times higher than that during the Miocene.This abrupt change in denudation rate during Pliocene pervaded the Himalayan orogen,and was roughly synchronous with a marked change in global climate at 4–3 Ma,and intensification of the Asian monsoon.Importantly,the later period of rapid denudation in the study region closely coupled to the mean annual precipitation,while there is no clear evidence for large-scale faulting activity and associated uplift during this period.Therefore,climate(precipitation)is inferred to be the main cause of the rapid denudation of the Himalayan orogen since the Pliocene.     

新生儿脐血瘦素水平的初步研究

目的:研究脐血瘦素水平与新生儿性别、孕周、出生体重、身高、体重指数及胎盘重量的关系。方法:应用酶联免疫法(ELISA)测定脐血瘦素水平,共测定了46份样本,运用统计学方法分析其与新生儿性别、孕周、出生体重、身高、体重指数BMI(即体重除以身高的平方,单位为kg·m~(-2)及与胎盘重量等的关系。结果:脐血瘦素水平与出生体重、身高、体重指数及胎盘的重量有着显著性相关,而男女性别间脐血瘦素水平无显著性差异。结论:脐血瘦素水平与新生儿孕周、出生体重、身高、体重指数及胎盘重量有密切关系,临床测定脐血瘦素水平对预测胎儿出生体重和生长发育有重要意义。     

河蚬(Corbicula fluminea)对氧化石墨烯和全氟辛烷磺酸类物质(PFOS)联合胁迫的生理生化响应

为了探索碳纳米材料氧化石墨烯(GO)和全氟辛烷磺酸类物质(PFOS)在淡水底栖贝类体内的联合毒性效应, 以河蚬为研究对象, 考察 1 mg/L GO和500 ng/L PFOS单独及联合暴露28天后对河蚬体长、体重、滤食率、活性氧水平、抗氧化系统酶活性和丙二醛含量的影响, 并采用优化的综合生物标志物响应指数(EIBR)进行整体评估。结果表明, 暴露结束后, 河蚬的体长和体重没有明显的变化。与空白对照组和溶剂对照组相比, GO和PFOS的单独暴露组及联合暴露组的滤食率均显著下降。在河蚬的鳃和内脏团中, GO和PFOS的胁迫都会引起抗氧化系统酶活性响应的显著变化, 且两器官中变化趋势一致。EIBR结果表明, 鳃和内脏团中联合暴露组的毒性比 PFOS或GO单独暴露组的毒性更强。     

基于PSS/PAH包被的AuNRs免疫传感器用于CEA的测定

通过聚苯乙烯磺酸钠(PSS)与聚丙烯氯化铵(PAH)以层层堆积(LBL)的形式包被到金纳米棒(AuNRs)的表面,从而替换AuNRs表面具有生物毒性的十六烷基三甲基溴化铵(CTAB).将癌胚抗原(CEA)的抗体(Ab)交联到AuNRs的表面,研制出一种新的癌胚抗原(CEA)的检测方法.随着CEA与AuNRs表面的Ab发生特异性反应,使AuNRs发生自组装,从而导致其紫外可见吸收光谱发生变化.通过测量吸收光谱的变化可以实现CEA的定量检测.采用电化学交流阻抗法和循环伏安法考察了不同修饰层结合到AuNRs表面后的变化情况;考察了溶液pH、Ab与CEA的结合时间对响应的影响.在最优条件下,该传感器的检测范围为10~100ng/mL,检测下限为3.3ng/mL.     

Rapid point-of-use water purification using nanoscale zero valent iron (nZVI) particles

Nanoscale zero-valent iron (nZVI) particles are increasingly being investigated in removing aqueous contaminants. Here, we have demonstrated its inactivation and magnetic removal of bacteria and endotoxins from environmental wastewater samples. Varying dosages (10–1,000 μL) of 0–6 days aged nZVI with a concentration of 5 mg/mL for 2 mL wastewater samples were tested, and relevant removal efficiencies were determined using culturing method for bacteria and limulus amebocyte lysate (LAL) for endotoxins. The supernatants of wastewater samples after reacting with nZVI and subsequent magnetic separations were subjected to spectroscopic, qPCR and DGGE analysis. Overall, high magnetic bacterial removal efficiencies were observed up to 3–4 logs for 1 mL nZVI, while the removal efficiencies decreased sharply down to 0.5 log for 10 μL nZVI. qPCR and DGGE results revealed that higher dosages of nZVI caused severe bacterial cell membrane ruptures, releasing significant amounts of DNA up to 10⁷–10⁸ gene copies/mL when 1 mL nZVI was used. Richer DGGE patterns were observed for higher nZVI dosages. In addition, regardless of the dosages (10–1,000 μL) we have observed more than 90 % removal of endotoxins from the wastewater samples. The described technology has great promise to be used as a point-of-use water purification solution for various purposes.     

HPLC-MS/MS法快速测定鲜鱼肉中孔雀石绿及其代谢物含量

建立了鲜鱼肉中孔雀石绿及其代谢物隐色孔雀石绿残留量的高效液相色谱-串联质谱测定方法.采用电喷雾正离子模式离子化,选择反应扫描模式定量,孔雀石绿的定量监测离子对为m/z:329313,隐色孔雀石绿的定量监测离子对为m/z:331239,孔雀石绿的检出限为0.002 2ng/m L,定量限为0.007 3 ng/m L;隐色孔雀石绿的检出限为0.043 3 ng/m L,定量限为0.14 ng/m L,线性范围均为1~10 ng/m L,相对标准偏差均小于4%(n=6),方法的回收率均大于90%.     

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.     

Assessment of urinary concentration of cotinine in Chinese pregnant women exposed to environmental tobacco smoke

Environmental tobacco smoke （ETS） is a well- known reason of many adverse health consequences in pregnant women. Exposure of ETS during pregnancy may increase the risk of some fetal diseases in pregnant women and/or birth defects in neonates. Many countries have implemented laws to control smoking and free of second hand smoke in all enclosed workplaces. In China, anti- smoking law was enforced in March 2010. We aimed to assess the exposure of pregnant women to cotinine after anti-smoking law was implemented in China. The urine samples were collected from 2,100 volunteers from Zhejiang Province, China and urinary concentration of cotinine was measured using gas chromatography and mass spectrometry. Cotinine was detected in 87 % of the pregnant women. The GM and 95th percentile concentration in pregnant women were 4.28 and 44.00 μg/L, respectively. Similarly, the GM and 95th concentration of cotinine were significantly higher in smoking group than in non-smoking group （P 〈 0.0001）. Our results indicate that pregnant women in China are at the high risk of exposure ETS. Further attempts are required to make strategies to find out the sources of ETS exposure and prevent smoking at public places especially during pregnancy.     

Nanoscale structural and electronic evolution for increased efficiency in polymer solar cells monitored by electric scanning probe microscopy

Control of blend morphology at multi-scale is critical for optimizing the power conversion efficiency （PCE） of plastic solar cells. To better understand the physics of photoactive layer in the organic photovoltaic devices, it is necessary to gain understanding of morphol- ogy and the corresponding electronic property. Herein we report the correlation between nanoscale structural, electric properties of bulk heterojunction （BHJ） solar cells and the annealing-induced PCE change. We demonstrate that the PCE of BHJ solar cells are dramatically improved （from 1.3 % to 4.6 %） by thermal annealing, which results from P3HT crystalline stacking and the PCBM aggregation for interpenetrated network. The similar trend for annealing- induced photovoltage and PCE evolution present as an initial increase followed by a decrease with the annealing time and temperature. The surface roughness increase slowly and then abruptly after the same inflection points observed for photovoltage and PCE. The phase images in electric force microscopy indicate the optimized P3HT and PCBM crystallization for interpenetrating network formation considering the spectroscopic results as well. From the correlation between surface photovoltage, blend morphology, and PCE, we propose a model to illustrate the film structure and its evolution under different annealing conditions. This work would benefit the better design and optimization of the morphology and local electric proper- ties of solar cell active layers for improved PCE.     

环境污染物PFOS可引起大鼠海马干细胞的增殖

目的:观察全氟辛烷磺酰基化合物(PFOS)大鼠海马干细胞增殖情况.方法:利用大鼠腹腔内连续注射不同剂量的PFOS 14天,建立动物模型.以Brdu作标记物,利用免疫组织化学染色的方法检测不同剂量PFOS作用下大鼠海马干细胞增殖情况.结果:以Brdu作标记物,高剂量PFOS作用下大鼠海马内可检测到大量阳性细胞存在,对照组和低剂量PFOS作用下无此阳性结果产生.结论:推测PFOS可引起大鼠海马干细胞的增殖.