The Pearl River Delta(PRD)region has been identified as a significant hotspot of wet ammonium deposition.However,the absence of long-term monitoring data in the area hinders the comprehension of the historical trends ...The Pearl River Delta(PRD)region has been identified as a significant hotspot of wet ammonium deposition.However,the absence of long-term monitoring data in the area hinders the comprehension of the historical trends and changes in wet NH_(4)^(+)-N deposition in response to emissions,which interferes with the ability to make effective decisions.This study has analyzed the long-term trends of wet NH_(4)^(+)-N deposition flux and has quantified the effect of anthropogenic emissions and meteorological factors at a typical urban site and a typical forest site in the PRD region from 2009 to 2020.It revealed a significant decreasing trend in wet NH_(4)^(+)-N flux in both the typical urban and forest areas of the PRD region,at-6.2%/year(p<0.001)and-3.3%/year(p<0.001),respectively.Anthropogenic emissions are thought to have contributed 47%–57%of the wet NH_(4)^(+)-N deposition trend over the past 12 years compared to meteorological factors.Meteorological conditions dominated the interannual fluctuations in wet NH_(4)^(+)-N deposition with an absolute contribution of 46%–52%,while anthropogenic emissions change alone explained 10%–31%.NH_(3)emissions have the greatest impact on the urban area among anthropogenic emission factors,while SO_(2)emissions have the greatest impact on the forest area.Additionally,precipitation was identified as the primary meteorological driver for both sites.Our findings also imply that the benefits of NH_(3)emissions reductions might not immediately emerge due to interference from weather-related factors.展开更多
Dopamine （DA） exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid （RA,10 pmol/L,72 hours） followed by phorbol ester 12...Dopamine （DA） exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid （RA,10 pmol/L,72 hours） followed by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate （TPA,80 nmol/L,72 hours）. However,it remains unclear whether the alteration of phenotype observed in response to oxidative stress is associated with protein regulation in this cellular model for Parkinson＇s disease. The present study detected protein regulation affected by oxidative stress at a proteomic level：selection of differentially altered proteins using two dimensional difference in-gel electrophoresis and identification of these proteins using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The results demonstrated significant alterations in expression of six proteins in SH-SY5Y cells following the differentiation and fourteen proteins in the differentiated cells following the exposure,exemplified by an increase of tubulin alpha1 in the former but a decrease of tubulin alpha-ubiquitous chain in the latter. These results suggest that two potentially specific but relevant patterns of proteomic change may be produced in SH-SY5Y cells with the induction of differentiation by RA followed by TPA,and in the differentiated cells after DA exposure.展开更多
This study tracked the characteristics of atmospheric wet deposition of the toxic element arsenic(As)at both urban(Guangzhou(GZ))and forested(Dinghushan Natural Reserve(DHS))sites within the Pearl River Delta(PRD)regi...This study tracked the characteristics of atmospheric wet deposition of the toxic element arsenic(As)at both urban(Guangzhou(GZ))and forested(Dinghushan Natural Reserve(DHS))sites within the Pearl River Delta(PRD)region between 2016 and 2019,examining its correlation with rainfall patterns.Additionally,by employing backward trajectory analysis and the potential source contribution function(PSCF)in conjunction with pertinent emission inventories,we pinpointed the main pathways of atmospheric arsenic transport and evaluated the emission contributions from priority source areas.The study revealed that the atmospheric arsenic wet deposition fluxes at the GZ and DHS sites exhibited a trend of increase followed by a decrease over the four-year period.Wet season deposition fluxes were more than triple those of the dry season,with urban site showing a difference of over four times.Notably,wet season As deposition at both sites was predominantly affected by heavy rainfall from marine air masses,constituting 31%of the total deposition.The predominant trajectory directions contributing to arsenic deposition at GZ and DHS were northeast(55%)and south(53%),respectively.The primary source areas for both sites were largely outside the PRD region,with the GZ site having 80%to 95%of its source area in the non-PRD region,compared to 69%to 88%at the DHS site.Furthermore,non-PRD areas contributed approximately 65%to arsenic emissions for both sites,with the industrial sector being the dominant emission source,exceeding 97%of the total emissions.展开更多
The atmospheric deposition of heavy metals poses serious risks to the ecological system and human health. To advance our knowledge of atmospheric dry/wet heavy metal deposition in the PRD region, monthly fluxes were e...The atmospheric deposition of heavy metals poses serious risks to the ecological system and human health. To advance our knowledge of atmospheric dry/wet heavy metal deposition in the PRD region, monthly fluxes were examined based on soluble/insoluble fractions of five heavy metal elements（Cu, Pb, Cd, Cr and Zn） in samples collected from January 2014 to December 2015 at Guangzhou（urban） and Dinghushan（suburban） sites. The ratios of wet/dry deposition fluxes indicated that heavy metal deposition was governed by wet deposition rather than dry deposition in the PRD region. Affected by the shifting of the Asian monsoon, wet deposition fluxes exhibited significant seasonal variation between summer monsoon seasons（April to September） and winter monsoon seasons（October to February） in this region. Cd was classified as an extremely strong potential ecological risk based on solubility and the Hakanson ecological risk index. Source contributions to wet deposition were calculated by PMF, suggesting that dust, biomass burning, industries,vehicles, long-range transport and marine aerosol sources in Guangzhou, and Zn fertilizers,marine aerosol sources, agriculture, incense burning, biomass burning, vehicles and the ceramics industry in Dinghushan, were the potential sources of heavy metals.展开更多
BACKGROUND： To date, no drugs are able to halt the progression of Alzheimer＇s disease （AD）. Neural stem cells （NSCs） transplantation has been widely used to treat AD, but the mechanism of AD treatment remains un...BACKGROUND： To date, no drugs are able to halt the progression of Alzheimer＇s disease （AD）. Neural stem cells （NSCs） transplantation has been widely used to treat AD, but the mechanism of AD treatment remains unclear. OBJECTIVE： To observe changes in protein and factors in the hippocampus and frontal lobe of AD rats following NSCs transplantation, and to understand mechanism of action of NSCs transplantation in AD treatment. DESIGN, TIME AND SETTING： A randomized, controlled animal study was conducted at the First Clinical Hospital, Jilin University, China from July 2007 to March 2009. MATERIALS： NSCs were harvested from the hippocampus of 10 E16 Wistar rats. METHODS： A total of 57 male adult Wistar rats were equally and randomly divided into normal control, AD model and NSCs groups. AD models were established in the AD model and NSCs groups by bilateral removal of hippocampus. At 2 weeks postsurgery, NSCs were transplanted into the hippocampus of rats from the NSCs group. MAIN OUTCOME MEASURES： Protein levels were measured in the hippocampus of rats from normal control, NSCs and AD model groups using proteomics. Expression of choline acetyl transferase mRNA, glial fibrillary acidic protein and S100β was measured in the hippocampus and frontal lobe of rats using in situ hybridization and immunohistochemistry. RESULTS： Expression of choline acetyl transferase mRNA, heat shock protein 70, heat shock protein 90, F-actin and actin was significantly higher in the NSCs group compared with AD model group. Glial fibrillary acidic protein and S100β expression was less in the NSCs group compared with AD model group. CONCLUSlOIN： NSCs implanted into the brain may generate new neural cells, which can relieve damage to the cholinergic system and resist apoptosis. NSCs transplantation plays a protective role in the cholinergic system in the AD rats to some extent.展开更多
A dilatometer was used to study the kinetics of bainite-to-austenite transformation in low carbon microalloyed steel with the initial microstructure of bainite during the continuous reheating process. The bainite-to-a...A dilatometer was used to study the kinetics of bainite-to-austenite transformation in low carbon microalloyed steel with the initial microstructure of bainite during the continuous reheating process. The bainite-to-austenite trans- formation was observed to take place in two steps at low heating rate. The first step is the dissolution of bainite, and the second one is the remaining bainite-to-austenite transformation controlled by a dissolution process. The calculation result of the kinetics of austenite formation shows that the two steps occur by diffusion at low heating rate. However, at high heating rate the bainite-to-austenite transformation occurs in a single step, and the process is mainly dominated by shear. The growth rate of austenite reaches the maximum at about 835℃ at different heating rates and the growth rate of austenite as a function of temperature increases with the increase in heating rate.展开更多
The current electromagnetic environment brings a growing demand for efficient microwave absorption(MA)materials.Ti_(3)C_(2)T_(x)MXene,one of the 2D transition-metal carbides,is considered to be a promising MA material...The current electromagnetic environment brings a growing demand for efficient microwave absorption(MA)materials.Ti_(3)C_(2)T_(x)MXene,one of the 2D transition-metal carbides,is considered to be a promising MA material owing to its superior dielectric properties and structural processability.In order to further improve the MA performance and environmental adaptability of Ti_(3)C_(2)T_(x)MXene,Ti_(3)C_(2)T_(x)MXene-based MA materials enhanced by composition and structure design have been extensively studied and the regu-lation ideas for its MA properties can be outlined as component optimization and structure manipulation strategies based on the microwave absorption mechanism.Herein,we briefly introduced the microwave absorption mechanism and focused on the design strategies of Ti_(3)C_(2)T_(x)MXene-based MA materials based on recent advances.In addition,the prospects of Ti_(3)C_(2)T_(x)MXene-based MA materials were also discussed.展开更多
China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classifi...China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classified into two aspects,(1) Photochemical Reaction Condition(PRC = T_(2)× SW) and(2) Physical Dispersion Capacity(PDC = WS). In this way, a Meteorology Synthetic Index(MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O_(2)pollution. The positive linear relationship between the 90 th percentile of MDA8(maximum daily 8-h average) O_(2)concentration and MSI determined that the contribution of meteorological changes to ground-level O-3 varied on a latitudinal gradient, decreasing from ~40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O_(2)pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O_(2)variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies.展开更多
This study attempts to identify the dominant transport pathways,potential source areas,and their seasonal variation at sites with high inorganic nitrogen(IN)wet deposition flux in southern China.This is a long-term st...This study attempts to identify the dominant transport pathways,potential source areas,and their seasonal variation at sites with high inorganic nitrogen(IN)wet deposition flux in southern China.This is a long-term study(2010-2017)based on continuous deposition measurements at the Guangzhou urban site(GZ)and the Dinghushan Natural Reserve site(DHS)located in the Pearl River Delta(PRD)region.A dataset on monthly IN concentration in precipitation and wet deposition flux were provided.The average annual fluxes measured at both sites(GZ:33.04±9.52,DHS:20.52±10.22 kg N/(ha·year))were higher,while the ratios of reduced to oxidized N(GZ:1.19±0.77,DHS:1.25±0.84)were lower compared with the national mean level and the previous reported level throughout the PRD region.The dominant pathways were not always consistent with the highest proportional trajectory clusters.The transport pathways contributing most of deposition were identified in the north and northnortheast in the dry season and in the east-southeast,east,and south-southwest in the wet season.A weighted potential source contribution function(WPSCF)value>0.3 was determined reasonably to define the potential source area.Emission within the PRD region contributed the majority(≥95%at both sites)of the IN deposition in the wet season,while the contribution outside the region increased significantly in the dry season(GZ:27.86%,DHS:95.26%).Our results could help create more effective policy to control precursor emissions for IN fluxes,enabling reduction of the ecological risks due to excessive nitrogen.展开更多
In this paper, we report a rapid synthesis of piezoelectric ZnO-nanostructures and fabrication of the nanostructures- based power-generators demonstrating an energy conversion from an environmental mechanical/ultrason...In this paper, we report a rapid synthesis of piezoelectric ZnO-nanostructures and fabrication of the nanostructures- based power-generators demonstrating an energy conversion from an environmental mechanical/ultrasonic energy to an electrical energy. The ZnO nanostructures are grown on a silicon wafer by a modified chemical solution method （CSD, chemical-solution-deposition） with a two-step thermal-oxidation approach. The synthesis process can be completed within 1 h. By varying the mixture-ratio of Zn micro-particles in an oxalic acid solution with 0.75 mol/l concentration in the CSD process, the growth mechanism is well-controlled to synthesize three different types of ZnO-nanostructures （i.e., dandelion-like nanostructures, columnar nanostructures, and nanowires）. Furthermore, through oxidizing at different temperatures in the thermal-oxidation process, the featured geometry of the nanostructures （e.g., the length and diameter of a nanowire） is modified. The geometry, size, morphology, crystallization, and material phase of the modified nanostructures are characterized by scanning electron microscopy and X-ray diffraction. Finally, the nanostructures are used to fabricate several micro power-generators. Through the piezoelectric effect, a maximum current density output of 0.28 μA cm-2 generated by a power-generator under an ultrasonic wave is observed.展开更多
The National Solar Observatory is currently developing the Accurate Infrared Magnetic Field Measurements of the Sun(AIMS). The primary mirror of the AIMS solar telescope is an off-axis parabolic with a diameter of 1 m...The National Solar Observatory is currently developing the Accurate Infrared Magnetic Field Measurements of the Sun(AIMS). The primary mirror of the AIMS solar telescope is an off-axis parabolic with a diameter of 1 m and with a large off-axis amount of 1 m. Due to the surface figure of the primary mirror under the used state is directly related to image quality of the whole system, a computer-generated hologram(CGH) is carried out to test the primary mirror, and the test results are used to polish the mirror to a higher surface accuracy. However, the fact that the distortion exists in the testing results leads to the failure of a further guide to deterministic optical processing. In this paper, a distortion correction method is proposed, which uses an orthogonal set of vector polynomials to mapping the coordinates of the mirror and the pixels of fringes, and then an interpolation method is adopted to obtain the corrected results. The testing accuracy by using CGH is also verified by an auto-collimate test experiment. According to the distorted corrected results, the root-mean-square of the surface figure is about 1/50λ(λ=632.8 nm) after polishing.展开更多
BACKGROUND： Rotenone-induced neurotoxicity in PC 12 cells has been widely used to study the pathogenesis of Parkinson＇s disease. However, the precise mechanisms underlying rotenone-induced dopaminergic neuronal dege...BACKGROUND： Rotenone-induced neurotoxicity in PC 12 cells has been widely used to study the pathogenesis of Parkinson＇s disease. However, the precise mechanisms underlying rotenone-induced dopaminergic neuronal degeneration in Parkinson＇s disease remains unclear. OBJECTIVE： To establish rotenone-induced neurotoxicity in PC 12 cells, and to investigate the possible action pathways to rotenone-induced neural cell injury at the protein level. DESIGN, TIME AND SETTING： A controlled proteomics study was performed at the Department of Neurology, First Hospital, Jilin University between March 2006 and March 2007. MATERIALS： PC 12 cells were obtained from Shanghai Cell Bank of Chinese Academy of Sciences, China. Rotenone was provided by Sigma, USA. METHODS： PC 12 cells in logarithmic growth phase were treated under experimental and control conditions, respectively. A total of 0.5 μmol/L rotenone, or the same amount of Dulbecco＇s modified eagle＇s medium （DMEM）, was added in the experimental and control conditions, respectively. MAIN OUTCOME MEASURES： Following 72 hours of rotenone treatment, cellular survival rate was determined by methyl thiazolyl tetrazolium assay, and apoptotic changes were detected by Hoechst 33342 staining. Total cellular protein was extracted to acquire differential protein expression data utilizing two-dimensional differential in-gel electrophoresis. To identify differential protein spots, matrix-assisted laser desorption/ionization-time of flight mass spectrometry （MALDI-TOF-MS） was used. RESULTS： In the MTT assay, the experimental condition induced significantly less cell survival compared to the control condition （P 〈 0.01）. Hoechst 33342 staining revealed a larger number of apoptotic cells under the experimental condition compared to the control condition （P 〈 0.01）, as determined by the presence of nuclear condensation, pyknosis, and nuclear fragmentation. Two-dimensional electrophoresis results showed that the differential expression of protein spots 1069 and 1538 was increased by 144% and 124%, respectively, while that of protein spot 1094 was decreased by 123% in the experimental condition compared to the control condition （P 〈 0.01）. By MALDI-TOF-MS analysis and database retrieval, γ-enolase, triosephosphate isomerase 1, and eukaryotic translation initiation factor 4A were confirmed to be involved in rotenone-induced neural cell injury. CONCLUSION： γ-enolase, triosephosphate isomerase 1, and eukaryotic translation initiation factor 4A might participate in rotenone-induced neurotoxicity in PC 12 cells.展开更多
This article compiles the actual knowledge of the biogenic volatile organic compound（BVOC） emissions estimated using model methods in the Pearl River Delta（PRD） region, one of the most developed regions in China. ...This article compiles the actual knowledge of the biogenic volatile organic compound（BVOC） emissions estimated using model methods in the Pearl River Delta（PRD） region, one of the most developed regions in China. The developed history of BVOC emission models is presented briefly and three typical emission models are introduced and compared. The results from local studies related to BVOC emissions have been summarized. Based on this analysis, it is recommended that local researchers conduct BVOC emission studies systematically, from the assessment of model inputs, to compiling regional emission inventories to quantifying the uncertainties and evaluating the model results. Beyond that,more basic researches should be conducted in the future to close the gaps in knowledge on BVOC emission mechanisms, to develop the emission models and to refine the inventory results. This paper can provide a perspective on these aspects in the broad field of research associated with BVOC emissions in the PRD region.展开更多
Parkinson＇s disease （PD） is the second most common neurodegenerative disorder and is characterized by its progressive course. The current therapies are aimed at alleviating symptoms by rescuing the unbalanced physi...Parkinson＇s disease （PD） is the second most common neurodegenerative disorder and is characterized by its progressive course. The current therapies are aimed at alleviating symptoms by rescuing the unbalanced physiological dopamine metabolism and recovery of damaged neuronal circuits. However, these strategies result in insufficient clinical benefits for many patients and fail to halt disease progression. Therefore, new therapeutic targets could serve as the gateway against PD degeneration. One pathological hallmark of PD is the formation of intracytoplasmic protein inclusions or Lewy bodies, in neurons. Recent studies have suggested that Lewy bodies are formed similarly to aggresomes, and results have supported the concept that the novel cellular organelle, the aggresome, is a cytoprotective response that sequesters and facilitates clearance of potentially toxic protein aggregates. In addition, a-tubulin deacetylase has been shown to regulate aggresome formation and rescue neural cell viability in response to misfolded protein. Therefore, the regulation of aggresome formation to trigger cellular self-protection system could arrest PD progression. The present study discusses research progress related to Lewy bodies, aggresomes, and histone deacetylases, with an emphasis on histone deacetylase 6 and sirtuin type 2.展开更多
Proteasome dysfunction during dopaminergic degeneration induces proteolytic stress, and is a contributing factor for the onset and formation of Lewy bodies. Results from our previous studies showed that synthetic prot...Proteasome dysfunction during dopaminergic degeneration induces proteolytic stress, and is a contributing factor for the onset and formation of Lewy bodies. Results from our previous studies showed that synthetic proteasome inhibitor-induced inclusions in PC12 cells contained six subunits in the 26S proteasome. In the present study, mass spectrometry analysis of single protein spots resolved by two-dimensional gel electrophoresis and identified by bioinformatic analysis of peptide mass fingerprint （PMF） data were performed to comprehensively characterize the proteomic profile of the proteasome subunits. Results showed that six subunits in the 26S proteasome were characterized through accurate assignment by PMF data-specific protein identification in protein databases. Additionally, identification of one of the proteasome subunits was further confirmed using a subunit-specific antibody against non-adenosine triphosphatase subunit 11 of the 19S regulatory particle. Results suggest that the potential proteomic profile of six subunits in the 26S proteasome could be established from proteasome inhibitor-induced inclusions in PC12 cells.展开更多
Previous studies have demonstrated that ubiquitin-proteasome system function is significantly decreased in the substantia nigra of Parkinson＇s disease patients. In the present study, proteasome inhibitor Z-Ile-Glu（O...Previous studies have demonstrated that ubiquitin-proteasome system function is significantly decreased in the substantia nigra of Parkinson＇s disease patients. In the present study, proteasome inhibitor Z-Ile-Glu（OtBu）-Ala-Leucinal （PSI） was used to inhibit the function of the ubiquitin-proteasome system in PC12 cells to simulate Parkinson＇s disease. Oxidatively modified proteins were identified to determine pathogenesis of Parkinson＇s disease. Results demonstrated that 24 hours of 10 IJmol/L PSI-treatment in PC12 cells simulated pathological characteristics of Parkinson＇s disease： neuronal degeneration and eosinophilic inclusion formation in neurons. In PSI-treated PC12 cells, three oxidative proteins and a molecular chaperone family member were detected： chaperonin containing t-complex polypeptide 1 subunit 3, glucose-regulated protein 58, and heat shock protein 70. This is the first study to demonstrate oxidative modification of a molecule family in a cell model of Parkinson＇s disease induced with PSI.展开更多
基金supported by the National Natural Science Foundation(Nos.42275107,42121004,and 42375109)the National Key Research and Development Plan(No.2023YFC3706202)+1 种基金the Foundational and Applied Basic Research in Guangzhou in 2023(No.2023A04J0251)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(No.2019B121205004).
文摘The Pearl River Delta(PRD)region has been identified as a significant hotspot of wet ammonium deposition.However,the absence of long-term monitoring data in the area hinders the comprehension of the historical trends and changes in wet NH_(4)^(+)-N deposition in response to emissions,which interferes with the ability to make effective decisions.This study has analyzed the long-term trends of wet NH_(4)^(+)-N deposition flux and has quantified the effect of anthropogenic emissions and meteorological factors at a typical urban site and a typical forest site in the PRD region from 2009 to 2020.It revealed a significant decreasing trend in wet NH_(4)^(+)-N flux in both the typical urban and forest areas of the PRD region,at-6.2%/year(p<0.001)and-3.3%/year(p<0.001),respectively.Anthropogenic emissions are thought to have contributed 47%–57%of the wet NH_(4)^(+)-N deposition trend over the past 12 years compared to meteorological factors.Meteorological conditions dominated the interannual fluctuations in wet NH_(4)^(+)-N deposition with an absolute contribution of 46%–52%,while anthropogenic emissions change alone explained 10%–31%.NH_(3)emissions have the greatest impact on the urban area among anthropogenic emission factors,while SO_(2)emissions have the greatest impact on the forest area.Additionally,precipitation was identified as the primary meteorological driver for both sites.Our findings also imply that the benefits of NH_(3)emissions reductions might not immediately emerge due to interference from weather-related factors.
基金the Science and Technology Development Program of Jilin Province, No. 200505200the Distinguished Professor Foundation of Jilin University, No. 450011011204
文摘Dopamine （DA） exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid （RA,10 pmol/L,72 hours） followed by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate （TPA,80 nmol/L,72 hours）. However,it remains unclear whether the alteration of phenotype observed in response to oxidative stress is associated with protein regulation in this cellular model for Parkinson＇s disease. The present study detected protein regulation affected by oxidative stress at a proteomic level：selection of differentially altered proteins using two dimensional difference in-gel electrophoresis and identification of these proteins using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The results demonstrated significant alterations in expression of six proteins in SH-SY5Y cells following the differentiation and fourteen proteins in the differentiated cells following the exposure,exemplified by an increase of tubulin alpha1 in the former but a decrease of tubulin alpha-ubiquitous chain in the latter. These results suggest that two potentially specific but relevant patterns of proteomic change may be produced in SH-SY5Y cells with the induction of differentiation by RA followed by TPA,and in the differentiated cells after DA exposure.
基金supported by the National Natural Science Foundation of China(Nos.42121004,42275107,and 42077205)the National Key Research and Development Plan(No.2023YFC3706202)+1 种基金the Foundational and Applied Basic Research in Guangzhou in 2023(No.2023A04J0251)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(No.2019B121205004)。
文摘This study tracked the characteristics of atmospheric wet deposition of the toxic element arsenic(As)at both urban(Guangzhou(GZ))and forested(Dinghushan Natural Reserve(DHS))sites within the Pearl River Delta(PRD)region between 2016 and 2019,examining its correlation with rainfall patterns.Additionally,by employing backward trajectory analysis and the potential source contribution function(PSCF)in conjunction with pertinent emission inventories,we pinpointed the main pathways of atmospheric arsenic transport and evaluated the emission contributions from priority source areas.The study revealed that the atmospheric arsenic wet deposition fluxes at the GZ and DHS sites exhibited a trend of increase followed by a decrease over the four-year period.Wet season deposition fluxes were more than triple those of the dry season,with urban site showing a difference of over four times.Notably,wet season As deposition at both sites was predominantly affected by heavy rainfall from marine air masses,constituting 31%of the total deposition.The predominant trajectory directions contributing to arsenic deposition at GZ and DHS were northeast(55%)and south(53%),respectively.The primary source areas for both sites were largely outside the PRD region,with the GZ site having 80%to 95%of its source area in the non-PRD region,compared to 69%to 88%at the DHS site.Furthermore,non-PRD areas contributed approximately 65%to arsenic emissions for both sites,with the industrial sector being the dominant emission source,exceeding 97%of the total emissions.
基金supported by the National Key Research and Development Program of China(No.2017YFC0210100)the National Science Foundation for Distinguished Young Scholars(No.41425020)+1 种基金the National Natural Scientific Foundation of China(Nos.41705123,41401569)the Guangdong Provincial Scientific Planning Project(No.2016B050502005)
文摘The atmospheric deposition of heavy metals poses serious risks to the ecological system and human health. To advance our knowledge of atmospheric dry/wet heavy metal deposition in the PRD region, monthly fluxes were examined based on soluble/insoluble fractions of five heavy metal elements（Cu, Pb, Cd, Cr and Zn） in samples collected from January 2014 to December 2015 at Guangzhou（urban） and Dinghushan（suburban） sites. The ratios of wet/dry deposition fluxes indicated that heavy metal deposition was governed by wet deposition rather than dry deposition in the PRD region. Affected by the shifting of the Asian monsoon, wet deposition fluxes exhibited significant seasonal variation between summer monsoon seasons（April to September） and winter monsoon seasons（October to February） in this region. Cd was classified as an extremely strong potential ecological risk based on solubility and the Hakanson ecological risk index. Source contributions to wet deposition were calculated by PMF, suggesting that dust, biomass burning, industries,vehicles, long-range transport and marine aerosol sources in Guangzhou, and Zn fertilizers,marine aerosol sources, agriculture, incense burning, biomass burning, vehicles and the ceramics industry in Dinghushan, were the potential sources of heavy metals.
基金the Jilin Pro-vincial Technology Devel-opment Foundation, No. 200505204, 200705129the Postdoctorate Founda-tion from Northeast Normal University, No. 111258000
文摘BACKGROUND： To date, no drugs are able to halt the progression of Alzheimer＇s disease （AD）. Neural stem cells （NSCs） transplantation has been widely used to treat AD, but the mechanism of AD treatment remains unclear. OBJECTIVE： To observe changes in protein and factors in the hippocampus and frontal lobe of AD rats following NSCs transplantation, and to understand mechanism of action of NSCs transplantation in AD treatment. DESIGN, TIME AND SETTING： A randomized, controlled animal study was conducted at the First Clinical Hospital, Jilin University, China from July 2007 to March 2009. MATERIALS： NSCs were harvested from the hippocampus of 10 E16 Wistar rats. METHODS： A total of 57 male adult Wistar rats were equally and randomly divided into normal control, AD model and NSCs groups. AD models were established in the AD model and NSCs groups by bilateral removal of hippocampus. At 2 weeks postsurgery, NSCs were transplanted into the hippocampus of rats from the NSCs group. MAIN OUTCOME MEASURES： Protein levels were measured in the hippocampus of rats from normal control, NSCs and AD model groups using proteomics. Expression of choline acetyl transferase mRNA, glial fibrillary acidic protein and S100β was measured in the hippocampus and frontal lobe of rats using in situ hybridization and immunohistochemistry. RESULTS： Expression of choline acetyl transferase mRNA, heat shock protein 70, heat shock protein 90, F-actin and actin was significantly higher in the NSCs group compared with AD model group. Glial fibrillary acidic protein and S100β expression was less in the NSCs group compared with AD model group. CONCLUSlOIN： NSCs implanted into the brain may generate new neural cells, which can relieve damage to the cholinergic system and resist apoptosis. NSCs transplantation plays a protective role in the cholinergic system in the AD rats to some extent.
文摘A dilatometer was used to study the kinetics of bainite-to-austenite transformation in low carbon microalloyed steel with the initial microstructure of bainite during the continuous reheating process. The bainite-to-austenite trans- formation was observed to take place in two steps at low heating rate. The first step is the dissolution of bainite, and the second one is the remaining bainite-to-austenite transformation controlled by a dissolution process. The calculation result of the kinetics of austenite formation shows that the two steps occur by diffusion at low heating rate. However, at high heating rate the bainite-to-austenite transformation occurs in a single step, and the process is mainly dominated by shear. The growth rate of austenite reaches the maximum at about 835℃ at different heating rates and the growth rate of austenite as a function of temperature increases with the increase in heating rate.
基金financially supported by the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Inno-vation Team of Structural-Functional Polymer Composites),and the Special Financial of Shandong Province(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Mate-rials and Construction of Shandong Provincial Talent Teams(No.37000022P990304116449)).
文摘The current electromagnetic environment brings a growing demand for efficient microwave absorption(MA)materials.Ti_(3)C_(2)T_(x)MXene,one of the 2D transition-metal carbides,is considered to be a promising MA material owing to its superior dielectric properties and structural processability.In order to further improve the MA performance and environmental adaptability of Ti_(3)C_(2)T_(x)MXene,Ti_(3)C_(2)T_(x)MXene-based MA materials enhanced by composition and structure design have been extensively studied and the regu-lation ideas for its MA properties can be outlined as component optimization and structure manipulation strategies based on the microwave absorption mechanism.Herein,we briefly introduced the microwave absorption mechanism and focused on the design strategies of Ti_(3)C_(2)T_(x)MXene-based MA materials based on recent advances.In addition,the prospects of Ti_(3)C_(2)T_(x)MXene-based MA materials were also discussed.
基金supported by the National Key Research and Development Plan(Grant No.2017YFC0210105)the second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0604)+7 种基金the National Natural Science Foundation of China(Grant Nos.41905086,41905107,42077205,and 41425020)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(Grant No.2019B121205004)the China Postdoctoral Science Foundation(Grant No.2020M683174)the Air Quip(High-resolution Air Quality Information for Policy)Project funded by the Research Council of Norwaythe Collaborative Innovation Center of Climate ChangeJiangsu ProvinceChinathe high-performance computing platform of Jinan University。
文摘China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classified into two aspects,(1) Photochemical Reaction Condition(PRC = T_(2)× SW) and(2) Physical Dispersion Capacity(PDC = WS). In this way, a Meteorology Synthetic Index(MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O_(2)pollution. The positive linear relationship between the 90 th percentile of MDA8(maximum daily 8-h average) O_(2)concentration and MSI determined that the contribution of meteorological changes to ground-level O-3 varied on a latitudinal gradient, decreasing from ~40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O_(2)pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O_(2)variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies.
基金supported by National Key Research and Development Plan(No.2017YFC0210100)the National Natural Science Foundation of China(Nos.41905086,41905107,42077205,41425020)+4 种基金the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(No.2019B121205004)the Natural Science Foundation of Guangdong Province(No.2019A1515011291)the China Postdoctoral Science Foundation(No.2020M683174)the Air Quip(High resolution Air Quality Information for Policy)Project funded by the Research Council of Norway,the Collaborative Innovation Center of Climate Change,Jiangsu province,China,the high-performance computing platform of Jinan University,the Mt.Dinghu Forest Ecosystem Research Station,Chinese Academy of Sciences(CAS)the Comprehensive Observation and Study Site of Urban Meteorology and Environment,Sun Yat-sen University,and the Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies(No.2020B1212060025)
文摘This study attempts to identify the dominant transport pathways,potential source areas,and their seasonal variation at sites with high inorganic nitrogen(IN)wet deposition flux in southern China.This is a long-term study(2010-2017)based on continuous deposition measurements at the Guangzhou urban site(GZ)and the Dinghushan Natural Reserve site(DHS)located in the Pearl River Delta(PRD)region.A dataset on monthly IN concentration in precipitation and wet deposition flux were provided.The average annual fluxes measured at both sites(GZ:33.04±9.52,DHS:20.52±10.22 kg N/(ha·year))were higher,while the ratios of reduced to oxidized N(GZ:1.19±0.77,DHS:1.25±0.84)were lower compared with the national mean level and the previous reported level throughout the PRD region.The dominant pathways were not always consistent with the highest proportional trajectory clusters.The transport pathways contributing most of deposition were identified in the north and northnortheast in the dry season and in the east-southeast,east,and south-southwest in the wet season.A weighted potential source contribution function(WPSCF)value>0.3 was determined reasonably to define the potential source area.Emission within the PRD region contributed the majority(≥95%at both sites)of the IN deposition in the wet season,while the contribution outside the region increased significantly in the dry season(GZ:27.86%,DHS:95.26%).Our results could help create more effective policy to control precursor emissions for IN fluxes,enabling reduction of the ecological risks due to excessive nitrogen.
基金the National Science Council of the Republic of China,Taiwan,for fnancially supporting this research under Contract No.NSC 101-2218-E-539001 and NSC 102-2623-E-539-001-ET
文摘In this paper, we report a rapid synthesis of piezoelectric ZnO-nanostructures and fabrication of the nanostructures- based power-generators demonstrating an energy conversion from an environmental mechanical/ultrasonic energy to an electrical energy. The ZnO nanostructures are grown on a silicon wafer by a modified chemical solution method （CSD, chemical-solution-deposition） with a two-step thermal-oxidation approach. The synthesis process can be completed within 1 h. By varying the mixture-ratio of Zn micro-particles in an oxalic acid solution with 0.75 mol/l concentration in the CSD process, the growth mechanism is well-controlled to synthesize three different types of ZnO-nanostructures （i.e., dandelion-like nanostructures, columnar nanostructures, and nanowires）. Furthermore, through oxidizing at different temperatures in the thermal-oxidation process, the featured geometry of the nanostructures （e.g., the length and diameter of a nanowire） is modified. The geometry, size, morphology, crystallization, and material phase of the modified nanostructures are characterized by scanning electron microscopy and X-ray diffraction. Finally, the nanostructures are used to fabricate several micro power-generators. Through the piezoelectric effect, a maximum current density output of 0.28 μA cm-2 generated by a power-generator under an ultrasonic wave is observed.
基金funded by the West Light Foundation of the Chinese Academy of Sciences(Grant No.XAB2017B13)the National Natural Science Foundation of China(Grant No.11703072)。
文摘The National Solar Observatory is currently developing the Accurate Infrared Magnetic Field Measurements of the Sun(AIMS). The primary mirror of the AIMS solar telescope is an off-axis parabolic with a diameter of 1 m and with a large off-axis amount of 1 m. Due to the surface figure of the primary mirror under the used state is directly related to image quality of the whole system, a computer-generated hologram(CGH) is carried out to test the primary mirror, and the test results are used to polish the mirror to a higher surface accuracy. However, the fact that the distortion exists in the testing results leads to the failure of a further guide to deterministic optical processing. In this paper, a distortion correction method is proposed, which uses an orthogonal set of vector polynomials to mapping the coordinates of the mirror and the pixels of fringes, and then an interpolation method is adopted to obtain the corrected results. The testing accuracy by using CGH is also verified by an auto-collimate test experiment. According to the distorted corrected results, the root-mean-square of the surface figure is about 1/50λ(λ=632.8 nm) after polishing.
文摘BACKGROUND： Rotenone-induced neurotoxicity in PC 12 cells has been widely used to study the pathogenesis of Parkinson＇s disease. However, the precise mechanisms underlying rotenone-induced dopaminergic neuronal degeneration in Parkinson＇s disease remains unclear. OBJECTIVE： To establish rotenone-induced neurotoxicity in PC 12 cells, and to investigate the possible action pathways to rotenone-induced neural cell injury at the protein level. DESIGN, TIME AND SETTING： A controlled proteomics study was performed at the Department of Neurology, First Hospital, Jilin University between March 2006 and March 2007. MATERIALS： PC 12 cells were obtained from Shanghai Cell Bank of Chinese Academy of Sciences, China. Rotenone was provided by Sigma, USA. METHODS： PC 12 cells in logarithmic growth phase were treated under experimental and control conditions, respectively. A total of 0.5 μmol/L rotenone, or the same amount of Dulbecco＇s modified eagle＇s medium （DMEM）, was added in the experimental and control conditions, respectively. MAIN OUTCOME MEASURES： Following 72 hours of rotenone treatment, cellular survival rate was determined by methyl thiazolyl tetrazolium assay, and apoptotic changes were detected by Hoechst 33342 staining. Total cellular protein was extracted to acquire differential protein expression data utilizing two-dimensional differential in-gel electrophoresis. To identify differential protein spots, matrix-assisted laser desorption/ionization-time of flight mass spectrometry （MALDI-TOF-MS） was used. RESULTS： In the MTT assay, the experimental condition induced significantly less cell survival compared to the control condition （P 〈 0.01）. Hoechst 33342 staining revealed a larger number of apoptotic cells under the experimental condition compared to the control condition （P 〈 0.01）, as determined by the presence of nuclear condensation, pyknosis, and nuclear fragmentation. Two-dimensional electrophoresis results showed that the differential expression of protein spots 1069 and 1538 was increased by 144% and 124%, respectively, while that of protein spot 1094 was decreased by 123% in the experimental condition compared to the control condition （P 〈 0.01）. By MALDI-TOF-MS analysis and database retrieval, γ-enolase, triosephosphate isomerase 1, and eukaryotic translation initiation factor 4A were confirmed to be involved in rotenone-induced neural cell injury. CONCLUSION： γ-enolase, triosephosphate isomerase 1, and eukaryotic translation initiation factor 4A might participate in rotenone-induced neurotoxicity in PC 12 cells.
基金supported by the National Science Fund for Outstanding Young Scholars(No.41425020)the China Special Fund for Meteorological Research in the Public Interest(No.GYHY201406031)and the Key Projects in the National Science&Technology Pillar Program(No.2014BAC21B02)
文摘This article compiles the actual knowledge of the biogenic volatile organic compound（BVOC） emissions estimated using model methods in the Pearl River Delta（PRD） region, one of the most developed regions in China. The developed history of BVOC emission models is presented briefly and three typical emission models are introduced and compared. The results from local studies related to BVOC emissions have been summarized. Based on this analysis, it is recommended that local researchers conduct BVOC emission studies systematically, from the assessment of model inputs, to compiling regional emission inventories to quantifying the uncertainties and evaluating the model results. Beyond that,more basic researches should be conducted in the future to close the gaps in knowledge on BVOC emission mechanisms, to develop the emission models and to refine the inventory results. This paper can provide a perspective on these aspects in the broad field of research associated with BVOC emissions in the PRD region.
文摘Parkinson＇s disease （PD） is the second most common neurodegenerative disorder and is characterized by its progressive course. The current therapies are aimed at alleviating symptoms by rescuing the unbalanced physiological dopamine metabolism and recovery of damaged neuronal circuits. However, these strategies result in insufficient clinical benefits for many patients and fail to halt disease progression. Therefore, new therapeutic targets could serve as the gateway against PD degeneration. One pathological hallmark of PD is the formation of intracytoplasmic protein inclusions or Lewy bodies, in neurons. Recent studies have suggested that Lewy bodies are formed similarly to aggresomes, and results have supported the concept that the novel cellular organelle, the aggresome, is a cytoprotective response that sequesters and facilitates clearance of potentially toxic protein aggregates. In addition, a-tubulin deacetylase has been shown to regulate aggresome formation and rescue neural cell viability in response to misfolded protein. Therefore, the regulation of aggresome formation to trigger cellular self-protection system could arrest PD progression. The present study discusses research progress related to Lewy bodies, aggresomes, and histone deacetylases, with an emphasis on histone deacetylase 6 and sirtuin type 2.
基金the Science and Technology Commission Foundation of Jilin Province,No.200505200the Distinguished Professor Foundation of Jilin University,No.450011011204
文摘Proteasome dysfunction during dopaminergic degeneration induces proteolytic stress, and is a contributing factor for the onset and formation of Lewy bodies. Results from our previous studies showed that synthetic proteasome inhibitor-induced inclusions in PC12 cells contained six subunits in the 26S proteasome. In the present study, mass spectrometry analysis of single protein spots resolved by two-dimensional gel electrophoresis and identified by bioinformatic analysis of peptide mass fingerprint （PMF） data were performed to comprehensively characterize the proteomic profile of the proteasome subunits. Results showed that six subunits in the 26S proteasome were characterized through accurate assignment by PMF data-specific protein identification in protein databases. Additionally, identification of one of the proteasome subunits was further confirmed using a subunit-specific antibody against non-adenosine triphosphatase subunit 11 of the 19S regulatory particle. Results suggest that the potential proteomic profile of six subunits in the 26S proteasome could be established from proteasome inhibitor-induced inclusions in PC12 cells.
基金the Scientific Research Foundation of Department of Science and Technology of Jilin Province,No. 200505200
文摘Previous studies have demonstrated that ubiquitin-proteasome system function is significantly decreased in the substantia nigra of Parkinson＇s disease patients. In the present study, proteasome inhibitor Z-Ile-Glu（OtBu）-Ala-Leucinal （PSI） was used to inhibit the function of the ubiquitin-proteasome system in PC12 cells to simulate Parkinson＇s disease. Oxidatively modified proteins were identified to determine pathogenesis of Parkinson＇s disease. Results demonstrated that 24 hours of 10 IJmol/L PSI-treatment in PC12 cells simulated pathological characteristics of Parkinson＇s disease： neuronal degeneration and eosinophilic inclusion formation in neurons. In PSI-treated PC12 cells, three oxidative proteins and a molecular chaperone family member were detected： chaperonin containing t-complex polypeptide 1 subunit 3, glucose-regulated protein 58, and heat shock protein 70. This is the first study to demonstrate oxidative modification of a molecule family in a cell model of Parkinson＇s disease induced with PSI.
