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Characteristics of Elemental Composition of PM_(2.5) in the Spring Period at Tongyu in the Semi-arid Region of Northeast China 被引量:7
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作者 张仁健 符淙斌 +1 位作者 韩志伟 朱崇抒 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2008年第6期922-931,共10页
Continuous observations of mass concentration and elemental composition of aerosol particles (PM2.5) were conducted at Tongyu, a semi-arid site in Northeast China in the spring of 2006. The average mass concentratio... Continuous observations of mass concentration and elemental composition of aerosol particles (PM2.5) were conducted at Tongyu, a semi-arid site in Northeast China in the spring of 2006. The average mass concentration of PM2.5 at Tongyu station was 260.9±274.4 μg m^-3 during the observation period. Nine dust events were monitored with a mean concentration of 528.0±302.7 μgm^-3. The PM2.5 level during non- dust storm (NDS) period was 111.65±63.37 μg m^-3. High mass concentration shows that fine-size particles pollution was very serious in the semi-arid area in Northeast China. The enrichment factor values for crust elements during the dust storm (DS) period are close to those in the NDS period, while the enrichment factor values for pollution elements during the NDS period are much higher than those in the DS period, showing these elements were from anthropogenic sources. The ratios of dust elements to Fe were relative constant during the DS period. The Ca/Fe ratio in dust aerosols at Tongyu is remarkably different from that observed in other source regions and downwind regions. Meteorological analysis shows that dust events at Tongyu are usually associated with dry, low pressure and high wind speed weather conditions. Air mass back-trajectory analysis identified three kinds of general pathways were associated with the aerosol particle transport to Tongyu, and the northwest direction pathway was the main transport route. 展开更多
关键词 dust aerosol mass concentration elemental composition transport pathway
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Chemical characteristics of aerosol particles (PM_(2.5)) at a site of Horqin Sand-land in northeast China 被引量:4
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作者 SHEN Zhen-xing CAO Jun-ji +3 位作者 LI Xu-xiang WANG Ya-qiang JIE Dong-mei ZHANG Xiao-ye 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第4期701-707,共7页
The objective of this study was to characterize the mass concentration and chemical composition of aerosol particles(PM2.5) collected at Tongliao(Inner Mongolia Autonomous Region, China), a site in Horqin Sand-lan... The objective of this study was to characterize the mass concentration and chemical composition of aerosol particles(PM2.5) collected at Tongliao(Inner Mongolia Autonomous Region, China), a site in Horqin Sand-land in northeast China. During spring 2005, the mass concentration for PM2.5 was (126±71)μg/m^3 in average. Five dust storm events were monitored with higher concentration of (255 ± 77)μg/m^3 in average than the non dusty days of (106 ± 44)μg/m^3. Concentrations for 20 elements were obtained by the PIXE method. Mass concentrations of ALl, Mg, Si, K, Ca, Ti, Mn, and V, which increased with the PM2.5 concentration, were higher than the pollution elements (S, Cl, Zn, Ar, Se, Br, and Pb). Enrichment factor relative to crust material was also calculated, which showed dust trace elements were mainly from earth upper crust and pollution elements were dominated the anthropogenic aerosols. The Si/Al, Ca/Al, and Fe/Al ratios in PM2.5 samples at Tongliao were 4.07, 0.94, and 0.82, respectively, which were remarkably different with those on other source regions, such as "Western desert source region", "North desert source region" and central Asia source. Air mass back-trajectory analysis identified three kinds of general pathways were associated with the aerosol particle transport to Tongliao, but have the similar elemental ratios, implying that elemental signatures for dust aerosol from Horqin Sand-land were different with other regions. 展开更多
关键词 dust aerosol mass concentration elemental composition transport pathway
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Surface water exchanges in the Luzon Strait as inferred from Lagrangian coherent structures 被引量:1
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作者 Zhehao Zheng Wei Zhuang +2 位作者 Jianyu Hu Zelun Wu Changjian Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2020年第11期21-32,共12页
This study presents a Lagrangian view of upper water exchanges across the Luzon Strait based on the finite-time Lyapunov exponents(FTLE)fields computed from the surface geostrophic current.The Lagrangian coherent stru... This study presents a Lagrangian view of upper water exchanges across the Luzon Strait based on the finite-time Lyapunov exponents(FTLE)fields computed from the surface geostrophic current.The Lagrangian coherent structures(LCSs)extracted from the FTLE fields well identify the typical flow patterns and eddy activities around the Luzon Strait.In addition,they reveal the intricate transport paths and fluid domains,which are validated by the tracks of satellite-tracked surface drifters and cannot be visually recognized in the velocity maps.The FTLE fields indicate that there are mainly four types of transport patterns near the Luzon Strait;among them,the Kuroshio northward-flowing"leaping"pattern and the clockwise rotating"looping"pattern occur more frequently than the"leaking"pattern of the direct Kuroshio branch into the SCS and the"outflowing"pattern from the SCS to the Pacific.The eddy shedding events of the Kuroshio at the Luzon Strait are further analyzed,and the importance of considering LCSs in estimating transport by eddies is highlighted.The anticyclonic eddy(ACE)shedding cases reveal that ACEs mainly originate from the looping paths of Kuroshio and thus could effectively trap the Kuroshio water before eddy detachments.LCSs provide useful information to predict the positions of the upstream waters that finally enter the ACEs.In contrast,LCS snapshots indicate that during the formation of cyclonic eddies(CEs),most CEs are not connected with the pathways of Kuroshio water.Hence,the contribution of CEs to the surface water exchanges from the Pacific into the SCS is tiny. 展开更多
关键词 Lagrangian coherent structures(LCSs) KUROSHIO Luzon Strait transport pathways particle tracking
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Baicalin protects neonatal rat brains against hypoxicischemic injury by upregulating glutamate transporter 1 via the phosphoinositide 3-kinase/protein kinase B signaling pathway 被引量:16
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作者 Zhi-qing Zhou Yong-liang Li +5 位作者 Zhen-bo Ao Zhi-li Wen Qi-wen Chen Zheng-gang Huang Bing Xiao Xiao-hua Yan 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第10期1625-1631,共7页
Baicalin is a flavonoid compound extracted from Scutellaria baicalensis root.Recent evidence indicates that baicalin is neuroprotective in models of ischemic stroke.Here,we investigate the neuroprotective effect of ba... Baicalin is a flavonoid compound extracted from Scutellaria baicalensis root.Recent evidence indicates that baicalin is neuroprotective in models of ischemic stroke.Here,we investigate the neuroprotective effect of baicalin in a neonatal rat model of hypoxic-ischemic encephalopathy.Seven-day-old pups underwent left common carotid artery ligation followed by hypoxia(8% oxygen at 37°C) for 2 hours,before being injected with baicalin(120 mg/kg intraperitoneally) and examined 24 hours later.Baicalin effectively reduced cerebral infarct volume and neuronal loss,inhibited apoptosis,and upregulated the expression of p-Akt and glutamate transporter 1.Intracerebroventricular injection of the phosphoinositide 3-kinase/protein kinase B(PI3 K/Akt) inhibitor LY294002 30 minutes before injury blocked the effect of baicalin on p-Akt and glutamate transporter 1,and weakened the associated neuroprotective effect.Our findings provide the first evidence,to our knowledge that baicalin can protect neonatal rat brains against hypoxic-ischemic injury by upregulating glutamate transporter 1 via the PI3 K/Akt signaling pathway. 展开更多
关键词 nerve regeneration baicalin hypoxia ischemia PI3K/Akt signaling pathway glutamate transporter 1 excitotoxicity neonatal rats apoptosis neural regeneration
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Influence of Iron Supplementation on DMT1(IRE)-induced Transport of Lead by Brain Barrier Systems in vivo 被引量:1
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作者 AN Dai Zhi AI Jun Tao +4 位作者 FANG Hong Juan SUN Ru Bao SHI Yun WANG Li Li WANG Qiang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第9期651-659,共9页
Objective To investigate the potential involvement of DMT1(IRE) protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water,... Objective To investigate the potential involvement of DMT1(IRE) protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the m RNA. Results Pb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1(IRE) protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1(IRE) m RNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1(IRE). Conclusion These results suggest that Pb is transported into the brain through DMT1(IRE), and the ERK MAPK pathway is involved in DMT1(IRE)-mediated transport regulation in brain vascular system in vivo. 展开更多
关键词 Lead Iron Blood-brain barrier Divalent metal transporter 1 MAPK pathway
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Seasonal variation of transport pathways and potential source areas at high inorganic nitrogen wet deposition sites in southern China 被引量:1
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作者 Shuidi He Minjuan Huang +4 位作者 Lianming Zheng Ming Chang Weihua Chen Qianqian Xie Xuemei Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第4期444-453,共10页
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
关键词 Inorganic nitrogen(IN) Wet deposition Seasonal variation Transport pathways Potential source areas Emission sectors
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Metabolic engineering of Bacillus amyloliquefaciens for efficient production ofα-glucosidase inhibitor1-deoxynojirimycin 被引量:1
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作者 Xujie Li Meng Zhang +8 位作者 Yu Lu Ningyang Wu Jian’gang Chen Zhixia Ji Yangyang Zhan Xin Ma Junyong Chen Dongbo Cai Shouwen Chen 《Synthetic and Systems Biotechnology》 SCIE CSCD 2023年第3期378-385,共8页
Owing to the feature of strongα-glucosidase inhibitory activity,1-deoxynojirimycin(1-DNJ)has broad application prospects in areas of functional food,biomedicine,etc.,and this research wants to construct an efficient ... Owing to the feature of strongα-glucosidase inhibitory activity,1-deoxynojirimycin(1-DNJ)has broad application prospects in areas of functional food,biomedicine,etc.,and this research wants to construct an efficient strain for 1-DNJ production,basing on Bacillus amyloliquefaciens HZ-12.Firstly,using the temperature-sensitive shuttle plasmid T2(2)-Ori,gene ptsG in phosphotransferase system(PTS)was weakened by homologous recombination,and non-PTS pathway was strengthened by deleting its repressor gene iolR,and 1-DNJ yield of resultant strain HZ-S2 was increased by 4.27-fold,reached 110.72 mg/L.Then,to increase precursor fructose-6-phosphate(F-6-P)supply,phosphofructokinase was weaken,fructose phosphatase GlpX and 6-phosphate glucose isomerase Pgi were strengthened by promoter replacement,moreover,regulator gene nanR was deleted,1-DNJ yield was further increased to 267.37 mg/L by 2.41-fold.Subsequently,promoter of 1-DNJ synthetase cluster was optimized,as well as 5′-UTRs of downstream genes in synthetase cluster,and 1-DNJ produced by the final strain reached 478.62 mg/L.Last but not the least,1-DNJ yield of 1632.50 mg/L was attained in 3 L fermenter,which was the highest yield of 1-DNJ reported to date.Taken together,our results demonstrated that metabolic engineering was an effective strategy for 1-DNJ synthesis,this research laid a foundation for industrialization of functional food and drugs based on 1-DNJ. 展开更多
关键词 1-DEOXYNOJIRIMYCIN Bacillus amyloliquefaciens Metabolic engineering Glucose transport pathway Fructose 6-phosphate 1-DNJ synthetase Gene cluster
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The Rice RMR1 Associates with a Distinct Prevacuolar Compartment for the Protein Storage Vacuole Pathway 被引量:5
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作者 Yun Shen Junqi Wang +4 位作者 Yu Ding Sze Wan Lo Guillaume Gouzerh Jean-Marc Neuhau Liwen Jiang 《Molecular Plant》 SCIE CAS CSCD 2011年第5期854-868,共15页
Transport of vacuolar proteins from Golgi apparatus or trans-Golgi network (TGN) to vacuoles is a receptor-mediated process via an intermediate membrane-bound prevacuolar compartment (PVC) in plant cells. Both vac... Transport of vacuolar proteins from Golgi apparatus or trans-Golgi network (TGN) to vacuoles is a receptor-mediated process via an intermediate membrane-bound prevacuolar compartment (PVC) in plant cells. Both vacuolar sorting receptor (VSR) and receptor homology region-transmembrane domain-RING-H2 (RMR) proteins have been shown to function in transporting storage proteins to protein storage vacuole (PSV), but little is known about the nature of the PVC for the PSV pathway. Here, we use the rice RMR1 (OsRMR1) as a probe to study the PSV pathway in plants. Immunogold electron microscopy (EM) with specific OsRMR1 antibodies showed that OsRMR1 proteins were found in the Golgi apparatus, TGN, and a distinct organelle with characteristics of PVC in both rice culture cells and developing rice seeds, as well as the protein body type II (PBII) or PSV in developing rice seeds. This organelle, also found in both tobacco BY-2 and Arabidopsis suspension cultured cells, is morphologically distinct from the VSR-positive multivesicular lytic PVC or multivesicular body (MVB) and thus represent a PVC for the PSV pathway that we name storage PVC (sPVC). Further in vivo and in vitro interaction studies using truncated OsRMR1 proteins secreted into the culture media of transgenic BY-2 suspension cells demonstrated that OsRMR1 functions as a sorting receptor in transporting vicilin-like storage proteins. 展开更多
关键词 PSV RMR storage PVC sorting receptor transport pathway.
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