As the economy and technology keep growing,the mode of shared bikes gains popularity under these circumstances.At the current period,university students become fond of using shared bikes,which changes body health and ...As the economy and technology keep growing,the mode of shared bikes gains popularity under these circumstances.At the current period,university students become fond of using shared bikes,which changes body health and life style of university students.When this mode combines the characteristics and functions of shared bikes,it has a great impact on the awareness and motivation of work-out of university students.Supported by Internet technology,shared bikes meet the need of people that they can use them at any time,which is new and innovative to the university students.This article provides university students with shared bike service in campus by analyzing the influence of“Internet+shared bike”on health and sports of university students.It will promote the effective application of shared bikes.展开更多
Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research...Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.展开更多
We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the...We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.展开更多
In early 2019, Mozambique was struck by two cyclones, Cyclone Idai in Sofala Province and Cyclone Kenneth in Cabo Delgado Province. Outbreaks of cholera were declared soon after both cyclones in Beira and Pemba cities...In early 2019, Mozambique was struck by two cyclones, Cyclone Idai in Sofala Province and Cyclone Kenneth in Cabo Delgado Province. Outbreaks of cholera were declared soon after both cyclones in Beira and Pemba cities. In response to the emergencies and outbreaks, government and humanitarian partners collaborated to create a mobile phone based water quality monitoring program to monitor daily free residual chlorine (FRC) levels in the piped network in both locations and at accommodation centers created for internally displaced persons in Beira. Overall, 87% of the 1080 samples from the piped network in Beira had detectable FRC and at accommodation centers, 73% of the 179 samples collected had detectable FRC. In Pemba, 64% of the 114 total samples collected had detectable FRC. Data from the water quality monitoring programs allowed for the identification of trends that helped increase the effectiveness of the response, including identifying areas where chlorination could be strengthened with the installation of booster chlorinators, issues with the consistency of daily chlorine treatment, and sites where water availability was limited. The water quality monitoring activities were a result of productive collaboration and could be replicated after similar emergencies in cholera endemic areas to prevent and control outbreaks.展开更多
文摘近年来,抑郁症(major depressive disorder,MDD)与注意缺陷多动障碍(attention deficit hyperactivity disorder,ADHD)共病的现象愈发受到关注。在成人患者中,MDD共病ADHD通常意味着治疗费用高昂、药物反应欠佳以及疾病预后不良,且现有药物治疗存在一定局限性。考虑到执行功能障碍作为MDD和ADHD的关键共同特征,从执行功能层面出发,探讨共病在脑影像学方面的潜在机制,并寻求更为有效的治疗方法,显得尤为重要。近年来的研究表明,经颅直流电刺激(transcranial direct current stimulation,tDCS)作为一种能够调节特定脑区活动的非侵入性物理治疗方法,可有效改善MDD及成人ADHD的相关症状。该文回顾成人MDD共病ADHD所面临的治疗困境,从与执行功能相关的脑结构、脑功能网络等多个维度,综述成人MDD共病ADHD的可能机制,同时探讨了tDCS在治疗成人MDD共病ADHD的应用前景。
文摘As the economy and technology keep growing,the mode of shared bikes gains popularity under these circumstances.At the current period,university students become fond of using shared bikes,which changes body health and life style of university students.When this mode combines the characteristics and functions of shared bikes,it has a great impact on the awareness and motivation of work-out of university students.Supported by Internet technology,shared bikes meet the need of people that they can use them at any time,which is new and innovative to the university students.This article provides university students with shared bike service in campus by analyzing the influence of“Internet+shared bike”on health and sports of university students.It will promote the effective application of shared bikes.
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs Program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada。
文摘Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada.
文摘We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.
文摘In early 2019, Mozambique was struck by two cyclones, Cyclone Idai in Sofala Province and Cyclone Kenneth in Cabo Delgado Province. Outbreaks of cholera were declared soon after both cyclones in Beira and Pemba cities. In response to the emergencies and outbreaks, government and humanitarian partners collaborated to create a mobile phone based water quality monitoring program to monitor daily free residual chlorine (FRC) levels in the piped network in both locations and at accommodation centers created for internally displaced persons in Beira. Overall, 87% of the 1080 samples from the piped network in Beira had detectable FRC and at accommodation centers, 73% of the 179 samples collected had detectable FRC. In Pemba, 64% of the 114 total samples collected had detectable FRC. Data from the water quality monitoring programs allowed for the identification of trends that helped increase the effectiveness of the response, including identifying areas where chlorination could be strengthened with the installation of booster chlorinators, issues with the consistency of daily chlorine treatment, and sites where water availability was limited. The water quality monitoring activities were a result of productive collaboration and could be replicated after similar emergencies in cholera endemic areas to prevent and control outbreaks.
