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1Relative Contributions of Boundary-Layer Meteorological Factors to the Explosive Growth of PM2.5 during the Red-Alert Heavy Pollution Episodes in Beijing in December 2016显示文摘Based on observations of urban mass concentration of fine particulate matter smaller than 2.5 μm in diameter(PM_(2.5)), ground meteorological data, vertical measurements of winds, temperature, and relative humidity(RH), and ECMWF reanalysis data, the major changes in the vertical structures of meteorological factors in the boundary layer(BL) during the heavy aerosol pollution episodes(HPEs) that occurred in winter 2016 in the urban Beijing area were analyzed. The HPEs are divided into two stages: the transport of pollutants under prevailing southerly winds, known as the transport stage(TS), and the PM_(2.5) explosive growth and pollution accumulation period characterized by a temperature inversion with low winds and high RH in the lower BL, known as the cumulative stage(CS). During the TS, a surface high lies south of Beijing, and pollutants are transported northwards. During the CS, a stable BL forms and is characterized by weak winds, temperature inversion, and moisture accumulation. Stable atmospheric stratification featured with light/calm winds and accumulated moisture(RH > 80%) below 250 m at the beginning of the CS is closely associated with the inversion, which is strengthened by the considerable decrease in near-surface air temperature due to the interaction between aerosols and radiation after the aerosol pollution occurs. A significant increase in the PLAM(Parameter Linking Aerosol Pollution and Meteorological Elements) index is found, which is linearly related to PM mass change. During the first 10 h of the CS, the more stable BL contributes approximately 84% of the explosive growth of PM_(2.5) mass. Additional accumulated near-surface moisture caused by the ground temperature decrease, weak turbulent diffusion, low BL height, and inhibited vertical mixing of water vapor is conducive to the secondary aerosol formation through chemical reactions, including liquid phase and heterogeneous reactions, which further increases the PM_(2.5) concentration levels. The contribution of these reaction mechanisms to the explosive growth of PM_(2.5) mass during the early CS and subsequent pollution accumulation requires further investigation.junting zhong xiaoye zhang yaqiang wang junying sun yangmei zhang jizhi wang kaiyan tan xiaojing shen haochi che lu zhang zhouxiang zhang xuefei qi huarong zhao sanxue ren yang li 2017Journal of Meteorological Research2017,31,5:25
2Seasonal characterization of components and size distributions for submicron aerosols in Beijing显示文摘Submicron aerosols(PM1)in Beijing were studied using an Aerodyne aerosol mass spectrometer(AMS)from January to October 2008.This paper presents seasonal variations of different chemical components(sulfate,nitrate,ammonium,chloride and organics)and size distributions of PM1.Results show that mass concentration of PM1 was highest in summer,and lowest in autumn.Organics represented the dominant species in all seasons,accounting for 36%-58%of PM1,and their concentrations were highest in winter.Concentrations of inorganic components,sulfate,nitrate,and ammonium were highest in summer. Based on principal component analysis,organics were deconvolved and quantified as hydrocarbon-like and oxygenated organic aerosol(HOA and OOA,respectively).HOA was highest in winter,accounting for about 70%of organics.However,OOA was highest in summer,and had lower values in autumn and winter.A similar diurnal pattern of various components was ob- served,which is higher at nighttime and lower during daytime.HOA increased more dramatically than other species between 17:00 and 21:00 and peaked at noon,which could be related to cooking emissions. OOA,sulfate,nitrate,ammonium and chloride varied with the same trend.Their concentrations increased with solar radiation from 9:00 to 13:00,and declined with weakening solar radiation.Size distributions of all species showed apparent peaks in the range 500-600 nm.Size distributions of organics were much broader than other species,particularly in autumn and winter.Distributions of sulfate,nitrate and ammonium had similar patterns,broadening in winter.Contributions of different species were size-dependent;the finer the particle,the greater the contribution of organics.Organics represented more than 60%of particles smaller than 200 nm,contributing 50%to PM1 in winter.In spring and summer,HOA was the dominant organic fraction for particles smaller than 200 nm, while OOA contributed more to particles larger than 300 nm.In winter,HOA contributed more than OOA to all PM1 particles.ZHANG YangMei SUN JunYing ZHANG XiaoYe SHEN XiaoJing WANG TingTing QIN MingKai 2013Science China Earth Sciences2013,56,5:14
3Sedimentary Characteristics and Paleoenvironmental Records of Zabuye Salt Lake,Tibetan Plateau,since 128 ka BP显示文摘This paper for the first time reveals high-resolution core records of Zabuye Salt Lake in the interior of the Qinghai-Tibet Plateau.According to 1346 samples taken continuously,relatively accurate ^(14)C,U-series disequilibrium and ESR ages have been obtained,thus revealing that the lake core ages from 0 to 83.63m of hole SZK02 are~800 to over 128 ka.In the paper,the lake core sedimentary characteristics(including the lithologies and mineral assemblages)are analyzed in detail and correlated with ostracod assemblages I to XX and sporopollen zones A to I,and on the basis of an integrated analysis of theδ^(18)0 values of authigenic calcium-magnesium carbonate and environmental proxies of minerals,sporopollen and microfossils in the lake core,a correlation has been made of oxygen isotope change between this lake core and the Greenland GISP2 and GRIP and Guliya ice cores,and the climate of Zabuye Salt Lake since 128 ka BP is divided into the last interglacial stage (including substages e,d,c,b and a)of oxygen isotope stage(OIS)5,early glacial stadial of the last glacial stage of OIS 4,interglacial stadial of the last glacial stage of OIS 3,late glacial stadial of the last glacial stage or Last Glacial Maximum of OIS 2 and postglacial state of OIS 1;in addition,6 Heinrich (H_6-H_1)events,Younger Dryas event and 8.2 ka BP cold event have been recognized.ZHENG Mianping YUAN Heran LIU Junying LI Yanhe MA Zhibang SUN Qing 2007Acta Geologica Sinica(English Edition)2007,81,5:10
4Investigation on Uniaxial Tensile Instability of USIBOR1500 Steel Sheets at Elevated Temperature显示文摘In the sheet forming process with stretch, diffuse instability and localized instability usually occur in the process one after another. The necking rate has a great impact on the instability process and the forming limits of the rate sensitive material, such as USIBOR1500 steel sheets at elevated temperature. The available reports about this steel mainly focus on hot uniaxial tensile, martensitic transformation and forming process, but there are few investigations on instability behavior and forming limits. Based on Inoue Kachiro’s flow stress constitutive model at elevated temperature, combined with Swift’s diffuse instability rule and Hill’s localized instability rule, the relation is theoretically deduced between the diffuse necking rate along with the localized necking rate and the exponent of strain rate sensitivity together with the strain rate in the case of the USIBOR1500 steel sheets at elevated temperature. According to the time–temperature characteristics of the hot stamping process, tensile tests of the steel sheets were carried out on Gleeble3800, and the stress–strain curves were obtained at different temperatures and different strain rates. Then the values of the exponent of strain rate sensitivity and the hardening exponent were obtained through fitting the curves by least squares. The tests also helped to provide the distribution laws of the major strain of the specimens and the uniform strains as well as the necking width. The uniform strains obtained from the tests are matched well with the theoretical calculations.MIN Junying LIN Jianping TIAN Haobin SUN Guohua XU Zhou 2010Chinese Journal of Mechanical Engineering2010,23,1:9
5Biological Activity and Antibacterial Property of Nano-structured TiO_2 Coating Incorporated with Cu Prepared by Micro-arc Oxidation显示文摘Micro-arc oxidized Cu-incorporated TiO2 coatings(Cu—TiO2) were prepared in the Ca,P,Cu-containing electrolyte to obtain an implant material with superior biological activity and antibacterial property.The surface topography,phase,and element composition of the TiO2 and Cu—TiO2 coatings were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),and energy-dispersive X-ray spectrometry (EDS),respectively.Staphylococcus aureus(S.aureus) was selected to evaluate the antibacterial property of the Cu—TiO2 coatings,whereas osteoblastic MG63 cells were cultured on the coatings to investigate the biological activity.The obtained results demonstrated that Cu element was successfully incorporated into the porous nano-structured TiO2 coatings,which did not alter apparently the surface topography and phase composition of the coatings as compared to the Cu-free TiO2 coatings.Moreover,the antibacterial studies suggested that the Cu-incorporated TiO2 coatings could significantly inhibit the adhesion of S.aureus.In addition,the in vitro biological evaluation displayed that the adhesion,proliferation and differentiation of MG63 cells on the Cu-incorporated coatings were enhanced as compared to those on the Cu-free coatings and Ti plates.In conclusion,the innovative Cu-incorporated nano-structured TiO2 coatings on Ti substrate with excellent antibacterial property and biological activity are promising candidates for orthopedic implant.Wei Zhu Zhenxiang Zhang Beibei Gu Junying Sun Lixian Zhu 2013Journal of Materials Science & Technology2013,29,3:8
6Background concentrations of reactive gases and the impacts of long-range transport at the Jinsha regional atmospheric background station显示文摘Lorentz curve fittings are applied to frequency distributions of the concentrations of O 3 , CO, NO x and SO 2 recorded at the Jinsha regional atmospheric background station (JSH) from June 2006 to July 2007, and the peak concentrations of these species for the different seasons are obtained. The peak concentrations are considered to be representative of different background levels for certain processes. The peak concentrations are compared with the corresponding mean (median) concentrations, and the suitability and limitations of the mean (median) values as the background levels are discussed. The mean (median) values might represent the background concentrations in the region under some circumstances, but in other cases these values often underestimate or overestimate the true background concentrations owing to the transport of pollutants and other factors. The effects of air masses transported from different regions on the pollutant background concentrations are obtained by analyzing the 72-hour backward trajectories of air masses 100 m above the ground at JSH. These trajectories are estimated using the HYSPLIT model and then clustered for the measurement period. The spatial distribution and seasonal variations of trajectories and the corresponding mean concentrations of O 3 , SO 2 , NO x and CO for different clusters are analyzed. After filtering the seasonal changes in pollutant concentrations, the relative influences of air masses from different regions are obtained. The results show that JSH can be used to obtain the atmospheric background information of different air masses originating from or passing over the Yangtze River Delta, Central South China and the Jianghan Plain. Air masses from Central China, South China, and the western Yangtze River Delta contribute significantly to O 3 at JSH. Air masses from the north and northeast of JSH (i.e., the Jianghan Plain, Huang-Huai Plain and North China Plain) and the south (Central South China) contribute significantly to SO 2 , CO and NO x concentrations. Air masses originating from the ocean often bring clean air. Air masses originating from high altitudes over northwestern regions often have lower CO and NO x concentrations, lower relative humidity, and higher concentrations of O 3 and SO 2 .LIN WeiLi XU XiaoBin SUN JunYing LIUXiWen WANG Ying 2011Science China Earth Sciences2011,54,10:8
7Carbonaceous particles in the atmosphere and precipitation of the Nam Co region, central Tibet显示文摘A continuous air and precipitation sampling for carbonaceous particles was conducted in a field observatory beside Nam Co, Central Tibetan Plateau during July of 2006 through January of 2007. Organic carbon (OC) was the dominant composition of the carbonaceous particles both in the atmosphere (1660 ng/m 3 ) and precipitation (476 ng/g) in this area, while the average elemental carbon (BC) concentrations in the atmosphere and precipitation were only 82 ng/m 3 and 8 ng/g, respectively. Very high OC/BC ratio suggested local secondary organic carbon could be a dominant contribution to OC over the Nam Co region, while BC could be mainly originated from Southern Asia, as indicated by trajectory analysis and aerosol optical depth. Comparison between the BC concentrations measured in Lhasa, those at 'Nepal Climate Observatory at Pyramid (NCO-P)' site on the southern slope of the Himalayas, and Nam Co suggested BC in the Nam Co region reflected a background with weak anthropogenic disturbances and the emissions from Lhasa might have little impact on the atmospheric environment here, while the pollutants from the Indo-Gangetic Basin of Southern Asia could be transported to the Nam Co region by both the summer monsoon and the westerly.Jing Ming Cunde Xiao Junying Sun Shichang Kang Paolo Bonasoni 2010Journal of Environmental Sciences2010,22,11:7
8Aerosol Hygroscopicity during the Haze Red-Alert Period in December 2016 at a Rural Site of the North China Plain显示文摘A humidification system was deployed to measure aerosol hygroscopicity at a rural site of the North China Plain during the haze red-alert period 17–22 December 2016. The aerosol scattering coefficients under dry [relative humidity(RH) < 30%] and wet(RH in the range of 40%–85%) conditions were simultaneously measured at wavelengths of450, 550, and 700 nm. It is found that the aerosol scattering coefficient and backscattering coefficient increased by only 29% and 10%, respectively when RH went up from 40% to 80%, while the hemispheric backscatter fraction went down by 14%, implying that the aerosol hygroscopicity represented by the aerosol scattering enhancement factor f(RH) is relatively low and RH exerted little effects on the aerosol light scattering in this case. The scattering enhancement factors do not show significant differences at the three wavelengths, only with an approximate 2% variation, suggesting that the aerosol hygroscopicity is independent of the wavelength. Aerosol hygroscopicity is highly dependent on the aerosol chemical composition. When there is a large mass fraction of inorganics and a small mass fraction of organic matter, f(RH) reaches a high value. The fraction of NO_3^- was strongly correlated with the aerosol scattering coefficient at RH = 80%, which suggests that NO_3^- played an important role in aerosol hygroscopic growth during the heavy pollution period.Xuefei QI Junying SUN Lu ZHANG Xiaojing SHEN Xiaoye ZHANG Yangmei ZHANG Yaqiang WANG Haochi CHE Zhouxiang ZHANG Junting ZHONG Kaiyan TAN Huarong ZHAO Sanxue REN 2018Journal of Meteorological Research2018,32,1:7
9Enhanced Performance of Osteoblasts by Silicon Incorporated Porous TiO_2 Coating显示文摘Silicon (Si) incorporated porous TiO 2 coating (Si-TiO 2) prepared on titanium (Ti) by micro-arc oxidation (MAO) technique was demonstrated to be cytocompatible in previous studies.In view of the potential clinical applications,a detailed in vitro study of the biological activity of Si-TiO 2 coating,in terms of osteoblast (MC3T3-E1 cells) morphology,proliferation,differentiation and mineralization was performed.Immunofluorescent staining indicated that cells seeded on the Si-TiO 2 coating showed improved adhesion with developing mature cytoskeletons,which contained numerous distinct and well-defined actin stress fibers in the cell membranes compared with those on the TiO 2 coating and Ti plate.Results from proliferation assay showed that the proliferation rate of cells seeded on the Si-TiO 2 coating was significantly faster than that on the TiO 2 coating and Ti plate.Furthermore,the analysis of osteogenic gene expression demonstrated that the Si-TiO 2 coating stimulated the expression of osteoblast-related genes and promoted differentiation and mineralization of MC3T3-E1 cells.In addition,the Si-TiO 2 coating differentially regulated Wnt signaling pathway by up-regulating the expression of low-density lipoprotein (LDL) receptor-related protein 5 (Lrp5),and downregulating the expression of Dickkopf-1 (Dkk1).All together,these results indicate that the investigated titanium with Si-TiO 2 coating is biocompatible and a good candidate material used as implants.Quanming Wang Hongjie Hu Yuqing Qiao Zhengxiang Zheng Junying Sun 2012Journal of Materials Science & Technology2012,28,2:5
10Key features of new particle formation events at background sites in China and their influence on cloud condensation nuclei显示文摘Xiaojing SHEN Junying SUN Xiaoye ZHANG Yangmei ZHANG Lu ZHANG Ruxia FAN 2016Frontiers of Environmental Science & Engineering2016,10,5:5
11Highly efficient catalytic scavenging of oxygen free radicals with graphene-encapsulated metal nanoshields显示文摘Junying Wang Xiaoju Cui Haobo Li Jianping Xiao Jiang Yang Xiaoyu Mu Haixia Liu Yuan-Ming Sun Xuhui Xue Changlong Liu Xiao-Dong Zhang Dehui Deng Xinhe Bao 2018Nano Research2018,11,5:4
12Chemical Components, Variation, and Source Identification of PM1 during the Heavy Air Pollution Episodes in Beijing in December 2016显示文摘Air pollution is a current global concern. The heavy air pollution episodes(HPEs) in Beijing in December 2016 severely influenced visibility and public health. This study aims to survey the chemical compositions, sources, and formation processes of the HPEs. An aerodyne quadruple aerosol mass spectrometer(Q-AMS) was utilized to measure the non-refractory PM1(NR-PM1) mass concentration and size distributions of the main chemical components including organics, sulfate, nitrate, ammonium, and chloride in situ during 15–23 December 2016. The NR-PM1 mass concentration was found to increase from 6 to 188 μg m–3 within 5 days. During the most serious polluted episode, the PM1 mass concentration was about 2.6 times that during the first pollution stage and even 40 times that of the clean days. The formation rates of PM2.5 in the five pollution stages were 26, 22, 22, 32, and 67 μg m^(–3) h–1, respectively. Organics and nitrate occupied the largest proportion in the polluted episodes, whereas organics and sulfate dominated the submicron aerosol during the clean days. The size distribution of organics is always broader than those of other species, especially in the clean episodes. The peak sizes of the interested species grew gradually during different HPEs. Aqueous reaction might be important in forming sulfate and chloride, and nitrate was formed via oxidization and condensation processes. PMF(positive matrix factorization) analysis on AMS mass spectra was employed to separate the organics into different subtypes. Two types of secondary organic aerosol with different degrees of oxidation consisted of 43% of total organics. By contrast, primary organics from cooking, coal combustion, and traffic emissions comprised 57% of the organic aerosols during the HPEs.Yangmei ZHANG Yaqiang WANG Xiaoye ZHANG Xiaojing SHEN Junying SUN Lingyan WU Zhouxiang ZHANG Haochi CHE 2018Journal of Meteorological Research2018,32,1:4
13The m6A methylation regulates gonadal sex differentiation in chicken embryo显示文摘Background:As a ubiquitous reversible epigenetic RNA modification,N6-methyladenosine(m6A)plays crucial regulatory roles in multiple biological pathways.However,its functional mechanisms in sex determination and differentiation during gonadal development of chicken embryos are not clear.Therefore,we established a transcriptome-wide m6A map in the female and male chicken left gonads of embryonic day 7(E7)by methylated RNA immunoprecipitation sequencing(MeRIP-seq)to offer insight into the landscape of m6A methylation and investigate the post-transcriptional modification underlying gonadal differentiation.Results:The chicken embryonic gonadal transcriptome was extensively methylated.We found 15,191 and 16,111 m6A peaks in the female and male left gonads,respectively,which were mainly enriched in the coding sequence(CDS)and stop codon.Among these m6A peaks,we identified that 1013 and 751 were hypermethylated in females and males,respectively.These differential peaks covered 281 and 327 genes,such as BMP2,SMAD2,SOX9 and CYP19A1,which were primarily associated with development,morphogenesis and sex differentiation by functional enrichment.Further analysis revealed that the m6A methylation level was positively correlated with gene expression abundance.Furthermore,we found that YTHDC2 could regulate the expression of sex-related genes,especially HEMGN and SOX9,in male mesonephros/gonad mingle cells,which was verified by in vitro experiments,suggesting a regulatory role of m6A methylation in chicken gonad differentiation.Conclusions:This work provided a comprehensive m6A methylation profile of chicken embryonic gonads and revealed YTHDC2 as a key regulator responsible for sex differentiation.Our results contribute to a better understanding of epigenetic factors involved in chicken sex determination and differentiation and to promoting the future development of sex manipulation in poultry industry.Jianbo Li Xiuan Zhang Xiqiong Wang Congjiao Sun Jiangxia Zheng Junying Li Guoqiang Yi Ning Yang 2022Journal of Animal Science and Biotechnology2022,13,6:4
14Normal mode acoustic intensity flux in Pekeris waveguide and its cross spectra signal processing显示文摘分层的媒介正常模式理论很好在最后世纪的中间被建立了,但是很少注意对粒子速度地被给予了。对压力地和粒子速度的联合描述在 Pekeris 回答波导,特别垂直声学的紧张流动在这份报纸被建议。学习的结果两个都显示出那水平并且垂直声学的紧张流动因为在正常模式之间的干扰,有活跃、反应的部件。当一个声学的向量传感器适当地被放时,在低频率的垂直声学的紧张流动的反应部件声学的地能被用来看出来源指定了深度,尽管它不能搬运 energy.Then,垂直声学的紧张流动的反应部件具有为向量信号处理的重要性。压力和粒子速度十字系列信号处理算法被建议区分目标。HUI Junying SUN Guocang ZHAO Anbang 2009Chinese Journal of Acoustics2009,28,1:3
15Investigating the interlayer electron transport and its in?uence on the whole electric properties of black phosphorus显示文摘Two-dimensional(2D) nanomaterials have attracted great attention in next generation electronic and optoelectronic technologies due to the unique layered structure and excellent physical and chemical properties. However, the mechanism of transmission along the vertical direction of 2D semiconductor materials has not been investigated. Here, we use first-principles calculations to explore the bandgap energies along different directions, and fabricate a vertical, a lateral and a mixture-structured black phosphorus field effect transistor(BPFET) to study the electrical characteristics along different directions under variable temperatures. The variable temperature test indicates that the mixture-structured device performs more like a lateral device, while the conductance along the vertical direction is hard to be tuned by temperature and electrical field. The unchanged conductance under electric field and variable temperatures allows the vertical device to act as a fixed resistor, promising possible application for the prospective electronic and optoelectronic devices.Bensong Wan Shaoqiang Guo Jiacheng Sun Yufei Zhang Yuyan Wang Caofeng Pan Junying Zhang 2019Science Bulletin2019,64,4:3
16HLS bunch current measurement system显示文摘Bunch current is an important parameter for studying the injection fill-pattern in the storage ring and the instability threshold of the bunch, and the bunch current monitor also is an indispensable tool for the top-up injection. A bunch current measurement (BCM) system has been developed to meet the needs of the upgrade project of Hefei Light Source (HLS). This paper presents the layout of the BCM system. The system based on a high-speed digital oscilloscope can be used to measure the bunch current and synchronous phase shift. To obtain the absolute value of bunch-by-bunch current, the calibration coefficient is measured and analyzed. Error analysis shows that the RMS of bunch current is less than 0.01 mA when bunch current is about 5 mA, which can meet project requirement.YANG YongLiang MA TianJi SUN BaoGen LU Ping WANG JiGang ZOU JunYing TANG LeiLei 2011Science China(Physics,Mechanics & Astronomy)2011,54,S2:3
17Efficacy and safety of Liangxue Jiedu decoction for the treatment of progressive psoriasis vulgaris: a multicenter, randomized, controlled study显示文摘OBJECTIVE: To determine the clinical efficacy and safety of Liangxue Jiedu decoction(LJD) for the treatment of progressive psoriasis vulgaris and to provide the basis for the development of a standardized treatment protocol for psoriasis vulgaris.METHODS: In this multicenter, randomized, controlled study, patients with blood-heat type psoriasis were randomly assigned to receive either Chinese herbal medicine(LJD;treatment group) or Western Medicine(cetirizine hydrochloride, vitamin C, and vitamin B complex;control group). Psoriasis Area and Severity Index(PASI) scores were calculated in addition to the number of patients who achieved ≥ 50% or ≥ 75% improvement in PASI score from baseline. The change in symptoms of Chinese medicine(color of rash, burning sensation,itchiness, severity of irritation, and anger) was evaluated and safety was assessed as adverse events and laboratory analysis. t test, independent sample non-parametric test and χ2 test were used to analyze the results.RESULTS: A total of 238 participants were included in the study [treatment group, n = 122(PP analysis117);control group, n = 116(PP analysis 104)]. LJD treatment was associated with a significant improvement in skin lesions and symptoms com-pared with Western Medicine treatment. At the end of the 8-week treatment period, 23.77%(PP analysis 24.79%) of patients in the treatment group had achieved PASI75 and 57.38%(PP analysis 58.97%)had achieved PASI50;the corresponding figures in the control group were 9.48%(9.62%) and 25.00%(25.00%), respectively. The between-group differences were statistically significant(P < 0.05).CONCLUSION: Treatment of psoriasis vulgaris of the blood-heat type using LJD was associated with significantly better outcomes compared with those achieved using standard Western Medicine.Sun Liyun Li Tiantian Zhou Dongmei Yang Xiumin Tian Jing Zhao Junying Xu Wei He Yanling Liu Fang Tong Chunguan Chu Xiaoling Dai Ling Zhu Wei Xu Xuying Wang Ping 2020Journal of Traditional Chinese Medicine2020,40,2:3
18Detrimental effects of excessive fatty acid secretion on female sperm storage in chickens显示文摘Background:Female sperm storage(FSS),the maintenance of sperm inside the female reproductive tract for an extended period of time,is pervasive among organisms with internal fertilization.Because FSS enables asynchronous mating and fertilization,it could be extremely important to reproduction.However,the physiological mechanisms underlying prolonged preservation and maintenance are poorly understood.Here,we used chicken,a typical oviparous animal,to determine the mechanisms ensuring sperm functionality in sperm storage tubules(SSTs).Results:We performed an insemination experiment on over two thousand hens at two periods,and found that the FSS capabilities varied widely among individuals.Except for the differences in the SST density between the two groups with distinct FSS abilities,we quantitatively profiled small-molecule metabolites derived from SST cells,and identified 28 metabolites with differential expression.In particular,high levels of lipids,fatty acids and lipid peroxidation product were observed in hens with low FSS capability.Pathway analysis showed that these differential metabolites were significantly enriched in the biosynthesis of unsaturated fatty acids.Moreover,we detected the total antioxidant capacity and lipid peroxidation level of SSTs,and found that chickens with a lower FSS ability had a significantly higher content of lipid peroxidation end-product,which was 2.4-fold greater than chickens with a higher FSS capability,and no significant difference was found in the total antioxidant capacity between these two groups.Conclusions:Our findings reveal that the long-term storage of sperm and the maintenance of their function in the female reproductive tract require an adequate microenvironment.The superabundance of fatty acids secreted by SST cells had detrimental effects on sperm storage in the female reproductive tract.Lipid peroxidation produces toxic biological substances that may cause irreversible damage to resident spermatozoa,resulting in short-term sperm retention and decreased fertility.Our findings provide new avenues for studying sperm storage and sustaining fertility.Chaoliang Wen Chunning Mai Bin Wang Junying Li Congjiao Sun Ning Yang 2020Journal of Animal Science and Biotechnology2020,11,3:2
19Enhanced catalysis of ultrasmall Au-MoS_2 clusters against reactive oxygen species for radiation protection显示文摘Ionizing radiation produces excessive reactive oxygen species(ROS) which impose detrimental effects on biological systems. Thus, it is important to explore clinically safe and efficacious radioprotection agents to scavenge ROS and reduce the risks of radiotherapy. Recently, emerging catalytic nanomaterials such as sulfide nanomaterials have shown capability of clearing ROS in vivo by unique electron transfers between atoms, but their catalytic activities are yet suboptimal. As such, there is an unmet need to improve catalytic properties for stronger antioxidant activities and radiation protection. Herein, we prepared ultrasmall Au-MoS_2 clusters(~2.5 nm) and they showed enhanced catalytic properties via gold intercalation facilitating increased active sites and synergistic effects. Electrocatalysis results revealed that the catalytic activity of Au-MoS_2 towards H2O_2 was superior to ultrasmall MoS_2 without Au. As a result, we found that improving the electrocatalytic property of Au-MoS_2 can effectively enhance corresponding antioxidant activities and radioprotection effects in vivo. In addition, Au-MoS_2 also showed significant radioprotection in vitro and dramatically reduced the excess of radiation-induced adverse ROS. It also rescued radiation-induced DNA damages and protected the bone marrow hematopoietic system from ionizing radiation.Peixian Bian Jinxuan Zhang Junying Wang Jiang Yang Jingya Wang Haile Liu Yuanming Sun Meixian Li Xiao-Dong Zhang 2018Science Bulletin2018,63,14:2
20Development and application of the new BPM system data processing program at Hefei light source显示文摘A data processing program has been applied for the new beam position monitor (BPM) system of the storage ring at Hefei Light Source (HLS). The new BPM system in the upgrade project will be equipped with Libera Brilliance BPM processors to replace the old Bergoz MX-BPM processors. The embedded Linux system on Libera has completed some important work, including instrument status check,data acquisition, position calculation, EPICS IOC data release,and so on. A new EPICS record type has been developed to recalculate the beam position with log-ratio method. The property of the new position data was analyzed in the time and frequency domain. The results show that the rms value of beam position measurement resolution can be up to submicron. Preliminary studies have been carried out on the measurement of the tune and the beam lifetime with this new BPM system.MA Tianji YANG Yongliang SUN Baogen ZOU Junying LU Ping ZHOU Zeran XU Hongliang 2012Nuclear Science and Techniques2012,23,5:2
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