Ambient benzene homologues were measured at a site in the northeastern urban area of Beijing, China, from August 24 to September 4, 2012 by SUMMA canister sampling followed by laboratory determination using cryogenic ...Ambient benzene homologues were measured at a site in the northeastern urban area of Beijing, China, from August 24 to September 4, 2012 by SUMMA canister sampling followed by laboratory determination using cryogenic cold trap pre-concentration-GC-MS/FID, and their health risks were also assessed. Daily total benzene homologues ranged from 0.99 to 49.71 μg/m3 with an average of 11.98 μg/m3. Benzene homologues showed higher concentrations in the morning and evening than that at noontime. Comparison with previous studies revealed a trend of decrease for ambient benzene homologues probably due to the effective emission control in Beijing in recent years. Vehicular exhaust was the main source while volatilization of paints and solvents also made substantial contributions. Health risk assessment showed that BTEX （benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene） and styrene had no appreciable adverse non-cancer health risks for the exposed population, while benzene has potential cancer risk of 1.34E-05. Available data from cities in China all implied that benzene imposes relatively higher cancer risk on the exposed populations and therefore strict control measures should be taken to further lower ambient benzene levels in China.展开更多
The control of polarization,an essential property of light,is of broad scientific and technological interest.Polarizers are indispensable optical elements for direct polarization generation.However,arbitrary polarizat...The control of polarization,an essential property of light,is of broad scientific and technological interest.Polarizers are indispensable optical elements for direct polarization generation.However,arbitrary polarization generation,except that of common linear and circular polarization,relies heavily on bulky optical components such as cascading linear polarizers and waveplates.Here,we present an effective strategy for designing all-in-one full Poincare sphere polarizers based on perfect arbitrary polarization conversion dichroism and implement it in a monolayer all-dielectric metasurface.This strategy allows preferential transmission and conversion of one polarization state located at an arbitrary position on the Poincare sphere to its handedness-flipped state while completely blocking its orthogonal state.In contrast to previous methods that were limited to only linear or circular polarization,our method manifests perfect dichroism of nearly 100%in theory and greater than 90%experimentally for arbitrary polarization states.By leveraging this attractive dichroism,our demonstration of the generation of polarization beams located at an arbitrary position on a Poincare sphere directly from unpolarized light can substantially extend the scope of meta-optics and dramatically promote state-of-the-art nanophotonic devices.展开更多
Peritoneal fibrosis together with increased capillaries is the primary cause of peritoneal dialysis failure.Mesothelial cell loss is an initiating event for peritoneal fibrosis.We find that the elevated glucose concen...Peritoneal fibrosis together with increased capillaries is the primary cause of peritoneal dialysis failure.Mesothelial cell loss is an initiating event for peritoneal fibrosis.We find that the elevated glucose concentrations in peritoneal dialysate drive mesothelial cell pyroptosis in a manner dependent on caspase-3 and Gasdermin E,driving downstream inflammatory responses,including the activation of macrophages.Moreover,pyroptosis is associated with elevated vascular endothelial growth factor A and C,two key factors in vascular angiogenesis and lymphatic vessel formation.GSDME deficiency mice are protected from high glucose induced peritoneal fibrosis and ultrafiltration failure.Application of melatonin abrogates mesothelial cell pyroptosis through a MT1R-mediated action,and successfully reduces peritoneal fibrosis and angiogenesis in an animal model while preserving dialysis efficacy.Mechanistically,melatonin treatment maintains mitochondrial integrity in mesothelial cells,meanwhile activating m TOR signaling through an increase in the glycolysis product dihydroxyacetone phosphate.These effects together with quenching free radicals by melatonin help mesothelial cells maintain a relatively stable internal environment in the face of high-glucose stress.Thus,Melatonin treatment holds some promise in preserving mesothelium integrity and in decreasing angiogenesis to protect peritoneum function in patients undergoing peritoneal dialysis.展开更多
There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive.Herein,we design and fabricate a fluorinated phenolic polyuretha...There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive.Herein,we design and fabricate a fluorinated phenolic polyurethane(FPPU)elastomer based on octafluoro-4,4'-biphenol to overcome this challenge.This fluorine-based motif not only tunes interchain interactions throughπ-πstacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine atoms.The developed FPPU elastomer shows the highest recorded puncture energy(648.0 m J),high tensile strength(27.0 MPa),as well as excellent selfhealing efficiency(92.3%),along with low surface energy(50.9 MJ m^(-2)),notch-insensitivity,and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane(BPPU)elastomer.Taking advantage of the above-mentioned merits of FPPU elastomer,we prepare an anti-fouling triboelectric nanogenerator(TENG)with a self-healable,and reprocessable elastic substrate.Benefiting from stronger electron affinity of fluorine atoms than hydrogen atoms,this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU elastomer.Furthermore,a healable and stretchable conductive composite is prepared.This research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications.展开更多
基金supported by the Special Research Project for the National Environmental Protection Public Welfare Industry of China(No.201009032)the Strategic Pilot Science and Technology Project of Chinese Academy of Sciences(Class B)(No.XDB05010200)the Project of National Natural Science Foundation of China(No.41175111)
文摘Ambient benzene homologues were measured at a site in the northeastern urban area of Beijing, China, from August 24 to September 4, 2012 by SUMMA canister sampling followed by laboratory determination using cryogenic cold trap pre-concentration-GC-MS/FID, and their health risks were also assessed. Daily total benzene homologues ranged from 0.99 to 49.71 μg/m3 with an average of 11.98 μg/m3. Benzene homologues showed higher concentrations in the morning and evening than that at noontime. Comparison with previous studies revealed a trend of decrease for ambient benzene homologues probably due to the effective emission control in Beijing in recent years. Vehicular exhaust was the main source while volatilization of paints and solvents also made substantial contributions. Health risk assessment showed that BTEX （benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene） and styrene had no appreciable adverse non-cancer health risks for the exposed population, while benzene has potential cancer risk of 1.34E-05. Available data from cities in China all implied that benzene imposes relatively higher cancer risk on the exposed populations and therefore strict control measures should be taken to further lower ambient benzene levels in China.
基金supported by the National Key R&D Program of China(2018YFB1107200)the National Natural Science Foundation of China(NSFC)(Grants 62075084,61522504,61420106014,11734012,and 11574218)+3 种基金the Guangdong Provincial Innovation and Entrepreneurship Project(Grant 2016ZT06D081)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010615)the Fundamental Research Funds for the Central Universities(21620415)the China Scholarship Council(201906785011).
文摘The control of polarization,an essential property of light,is of broad scientific and technological interest.Polarizers are indispensable optical elements for direct polarization generation.However,arbitrary polarization generation,except that of common linear and circular polarization,relies heavily on bulky optical components such as cascading linear polarizers and waveplates.Here,we present an effective strategy for designing all-in-one full Poincare sphere polarizers based on perfect arbitrary polarization conversion dichroism and implement it in a monolayer all-dielectric metasurface.This strategy allows preferential transmission and conversion of one polarization state located at an arbitrary position on the Poincare sphere to its handedness-flipped state while completely blocking its orthogonal state.In contrast to previous methods that were limited to only linear or circular polarization,our method manifests perfect dichroism of nearly 100%in theory and greater than 90%experimentally for arbitrary polarization states.By leveraging this attractive dichroism,our demonstration of the generation of polarization beams located at an arbitrary position on a Poincare sphere directly from unpolarized light can substantially extend the scope of meta-optics and dramatically promote state-of-the-art nanophotonic devices.
基金supported by the National Key Research and Development Program of China (2023YFB4004702 and 2022YFB3504103)the National Natural Science Foundation of China(22272198)the Shccig-Qinling Program(SMYJY20220296)。
文摘缺陷工程被认为是提高催化剂性能的有效方法,因为它能使催化剂具有丰富的活性位点和合适的结合能,从而提高催化性能.本文采用简单的电沉积和酸蚀刻方法制备了双缺陷工程RuO_(2)/D-Co_(3)O_(4)/CC(低Ru负载2.42 wt%)复合材料,用于增强酸性介质中的氧析出反应(OER).所制备的RuO_(2)/D-Co_(3)O_(4)/CC催化剂采用物理化学技术进行了深入表征,结果表明催化剂中存在明显的阴离子和阳离子缺陷.实验研究表明具有双重缺陷的优化RuO_(2)/D-Co_(3)O_(4)/CC催化剂暴露了更多的电化学活性位点,有效降低了催化反应对电解质中质子浓度的依赖性,从而触发了高性能的OER.只需要181 mV的过电位就能驱动10 mA cm^(-2)的电流密度,并能在此电流密度下保持连续电解120 h.RuO_(2)/D-Co_(3)O_(4)/CC是一种很有前途的酸性OER电催化剂.
基金supported by the National Key Research and Development Program of China(2020YFC2005002)the National Natural Science Foundation of China(81970642,81370460,81700580,81670668,22222409)+1 种基金Key research and development grant from The Department of Science and Technology,Liaoning ProvinceInnovative Leading Researcher grant from the Department of Science and Technology,Dalian,and Key Laboratory of Immune,Genetic and Metabolic Kidney Diseases,Dalian,and Youth Innovation Promotion Association of CAS(2018212)。
文摘Peritoneal fibrosis together with increased capillaries is the primary cause of peritoneal dialysis failure.Mesothelial cell loss is an initiating event for peritoneal fibrosis.We find that the elevated glucose concentrations in peritoneal dialysate drive mesothelial cell pyroptosis in a manner dependent on caspase-3 and Gasdermin E,driving downstream inflammatory responses,including the activation of macrophages.Moreover,pyroptosis is associated with elevated vascular endothelial growth factor A and C,two key factors in vascular angiogenesis and lymphatic vessel formation.GSDME deficiency mice are protected from high glucose induced peritoneal fibrosis and ultrafiltration failure.Application of melatonin abrogates mesothelial cell pyroptosis through a MT1R-mediated action,and successfully reduces peritoneal fibrosis and angiogenesis in an animal model while preserving dialysis efficacy.Mechanistically,melatonin treatment maintains mitochondrial integrity in mesothelial cells,meanwhile activating m TOR signaling through an increase in the glycolysis product dihydroxyacetone phosphate.These effects together with quenching free radicals by melatonin help mesothelial cells maintain a relatively stable internal environment in the face of high-glucose stress.Thus,Melatonin treatment holds some promise in preserving mesothelium integrity and in decreasing angiogenesis to protect peritoneum function in patients undergoing peritoneal dialysis.
基金supported by the National Natural Science Foundation of China(52173117,52073049,and 21991123)the National Key Research and Development Program of China(2021YFC2101800 and 2021YFC2400802)+3 种基金Ningbo 2025 Science and Technology Major Project(2019B10068)the Natural Science Foundation of Shanghai(22ZR1400700)Shanghai Rising-Star Program(21QA1400200)the Science and Technology Commission of Shanghai Municipality(20DZ2254900 and 20DZ2270800)。
文摘There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive.Herein,we design and fabricate a fluorinated phenolic polyurethane(FPPU)elastomer based on octafluoro-4,4'-biphenol to overcome this challenge.This fluorine-based motif not only tunes interchain interactions throughπ-πstacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine atoms.The developed FPPU elastomer shows the highest recorded puncture energy(648.0 m J),high tensile strength(27.0 MPa),as well as excellent selfhealing efficiency(92.3%),along with low surface energy(50.9 MJ m^(-2)),notch-insensitivity,and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane(BPPU)elastomer.Taking advantage of the above-mentioned merits of FPPU elastomer,we prepare an anti-fouling triboelectric nanogenerator(TENG)with a self-healable,and reprocessable elastic substrate.Benefiting from stronger electron affinity of fluorine atoms than hydrogen atoms,this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU elastomer.Furthermore,a healable and stretchable conductive composite is prepared.This research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications.
