Size distributions of ambient aerosols at the Fresno Supersite were measured with four commercially available scanning mobility particle sizers (SMPS). TSI nano, TSI standard, Grimm, and MSP instruments were colloca...Size distributions of ambient aerosols at the Fresno Supersite were measured with four commercially available scanning mobility particle sizers (SMPS). TSI nano, TSI standard, Grimm, and MSP instruments were collocated at the Fresno Supersite and particle size distributions were measured continuously from August 18 through September 18, 2005. For particles with diameters between 10 and 200 nm, differences among hourly-average ambient particle concentrations ranged from 0% between the TSI nano and Grimm in the 30-50 nm size range to 39% between the Grimm and MSP in the 10-30 nm size range. MSP concentrations were 10-33% lower than those measured with the TSI standard for particles smaller than 200 nm. The TSI nano and TSI standard agreed to within 5% in their overlapping size range (10-84 nm). The TSI nano and Grimm agreed to within 40% for 5-10 nm particles.展开更多
In coordination with Global Cryosphere Watch (GCW) initiated by World Meteorology Administration (WMO), a regional ob- servation network is proposed based on existing stations/sites over High Asia and cryospberic ...In coordination with Global Cryosphere Watch (GCW) initiated by World Meteorology Administration (WMO), a regional ob- servation network is proposed based on existing stations/sites over High Asia and cryospberic elements required by GCW. Thus, High Asian Cryosphere (HAC) network is preliminary designed, composing of seven "supersites", each containing several refer- ence sites. The network covers major mountain ranges in High Asia, such as East Tianshan, Qilian, Tanggula, Nyainqentanglha, Himalayas as well as the central and eastern Qinghai-Xizang (Tibet) Plateau. Although multiple cryospberic elements were ob- served at the existing HAC network, many others, which are required by Integrated Global Observation System-Cryosphere Theme (IGOS-Cryosphere), are not yet included. More comprehensive observations are necessary to be included into "supersites" of HAC, so that the basic requirements for validation of satellite data, assimilation and coupled regional models can be met.展开更多
The COST Action FP0903 “Climate Change and Forest Mitigation and Adaptation in a Polluted Environment (MAFor)” involved 29 countries and created a platform for information exchange with experts from different fields...The COST Action FP0903 “Climate Change and Forest Mitigation and Adaptation in a Polluted Environment (MAFor)” involved 29 countries and created a platform for information exchange with experts from different fields, with the following main objectives: 1) to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment and 2) to reconcile process-oriented research, long-term monitoring and applied modelling at comprehensive forest research sites. In particular, MAFor translated the existing European knowledge on climate and air pollution dynamics into prospects for forest research and monitoring, with focus on the carbon, ozone, nitrogen and water budgets. The aim of this paper is to summarize scientific activities and achievements of MAFor: the creation of a meta-database for highlighting the available data and integrating the information from European forest research/monitoring networks;the development of a new concept of forest sites for research and monitoring (Supersites);the identification of the main knowledge gaps;and the definition of priorities for forest adaptation to climate change in a polluted environment. The action also increased European capacity building in this sector by organizing five conferences, granting 64 short-term scientific missions, organizing four training schools and publishing more than 100 papers.展开更多
Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(b...Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air quality.Emission factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies.Changes in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and discussed.Moreover,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant overestimation.Considering that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.展开更多
The constantly mutating severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)poses great risk of efficacy loss to the present neutralizing therapeutics.Thus,it is urgently needed to develop versatile strategies ...The constantly mutating severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)poses great risk of efficacy loss to the present neutralizing therapeutics.Thus,it is urgently needed to develop versatile strategies that enable rapid design and engineering of potent neutralizing therapeutics for newly emerging variants.Herein,we present an unprecedented DNA nanocrown that can topologically match and multivalently bind the S-trimer of SARS-CoV-2 and thereby inhibit its infection to host cells.A neutralizing aptamer binding the N-terminal domain(NTD)supersite of the S protein was first screened and identified.It was further elaborately engineered onto the best fitting tetrahedral DNA nanostructure to form a spike protein-capping nanocrown,which can effectively block not only wild-type(WT)SARS-CoV-2 pseudovirus,but also several important mutants including D614G,N501Y,andΔ69–70.Significantly,it can evidently diminish the RNA copies of authentic WT SARS-CoV-2 in host cells by 4.6 orders of magnitude.Therefore,utilizing the aptamer selection method and the dedicated engineering route,our topology-matching DNA framework provides a versatile platform for SARS-CoV-2 inhibition and has the potential to be facilely expanded to newly emerging variants and other fatal coronaviruses.展开更多
基金sponsored by the California Air Resources Board (ARB) under DRI project number 04-307U.S. EPA's Supersites Program at Fresno
文摘Size distributions of ambient aerosols at the Fresno Supersite were measured with four commercially available scanning mobility particle sizers (SMPS). TSI nano, TSI standard, Grimm, and MSP instruments were collocated at the Fresno Supersite and particle size distributions were measured continuously from August 18 through September 18, 2005. For particles with diameters between 10 and 200 nm, differences among hourly-average ambient particle concentrations ranged from 0% between the TSI nano and Grimm in the 30-50 nm size range to 39% between the Grimm and MSP in the 10-30 nm size range. MSP concentrations were 10-33% lower than those measured with the TSI standard for particles smaller than 200 nm. The TSI nano and TSI standard agreed to within 5% in their overlapping size range (10-84 nm). The TSI nano and Grimm agreed to within 40% for 5-10 nm particles.
基金supported by Chinese 973 Project (2007CB411503)Chinese COPES(GYHY200706005)Hundred Talent Project of Chinese Academy of Sciences
文摘In coordination with Global Cryosphere Watch (GCW) initiated by World Meteorology Administration (WMO), a regional ob- servation network is proposed based on existing stations/sites over High Asia and cryospberic elements required by GCW. Thus, High Asian Cryosphere (HAC) network is preliminary designed, composing of seven "supersites", each containing several refer- ence sites. The network covers major mountain ranges in High Asia, such as East Tianshan, Qilian, Tanggula, Nyainqentanglha, Himalayas as well as the central and eastern Qinghai-Xizang (Tibet) Plateau. Although multiple cryospberic elements were ob- served at the existing HAC network, many others, which are required by Integrated Global Observation System-Cryosphere Theme (IGOS-Cryosphere), are not yet included. More comprehensive observations are necessary to be included into "supersites" of HAC, so that the basic requirements for validation of satellite data, assimilation and coupled regional models can be met.
基金Support by the COST Action FP0903“Climate change and forest mitigation and adaptation in the polluted environment”
文摘The COST Action FP0903 “Climate Change and Forest Mitigation and Adaptation in a Polluted Environment (MAFor)” involved 29 countries and created a platform for information exchange with experts from different fields, with the following main objectives: 1) to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment and 2) to reconcile process-oriented research, long-term monitoring and applied modelling at comprehensive forest research sites. In particular, MAFor translated the existing European knowledge on climate and air pollution dynamics into prospects for forest research and monitoring, with focus on the carbon, ozone, nitrogen and water budgets. The aim of this paper is to summarize scientific activities and achievements of MAFor: the creation of a meta-database for highlighting the available data and integrating the information from European forest research/monitoring networks;the development of a new concept of forest sites for research and monitoring (Supersites);the identification of the main knowledge gaps;and the definition of priorities for forest adaptation to climate change in a polluted environment. The action also increased European capacity building in this sector by organizing five conferences, granting 64 short-term scientific missions, organizing four training schools and publishing more than 100 papers.
基金supported by the VOLTAIRE project (ANR-10-LABX-100-01)funded by the ANR and the PIVOTS project provided by the Region Centre−Val de Loire (ARD 2020 program and CPER 2015−2020).
文摘Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air quality.Emission factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies.Changes in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and discussed.Moreover,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant overestimation.Considering that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.
基金This work was supported by the Key Grant(grant no.21834003)from the National Natural Science Foundation of Chinathe National Key R&D Program of China(grant no.2018YFC0910301)from the Ministry of Science and Technology of Chinathe Excellent Research Program of Nanjing University(grant no.ZYJH004)to Z.L.
文摘The constantly mutating severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)poses great risk of efficacy loss to the present neutralizing therapeutics.Thus,it is urgently needed to develop versatile strategies that enable rapid design and engineering of potent neutralizing therapeutics for newly emerging variants.Herein,we present an unprecedented DNA nanocrown that can topologically match and multivalently bind the S-trimer of SARS-CoV-2 and thereby inhibit its infection to host cells.A neutralizing aptamer binding the N-terminal domain(NTD)supersite of the S protein was first screened and identified.It was further elaborately engineered onto the best fitting tetrahedral DNA nanostructure to form a spike protein-capping nanocrown,which can effectively block not only wild-type(WT)SARS-CoV-2 pseudovirus,but also several important mutants including D614G,N501Y,andΔ69–70.Significantly,it can evidently diminish the RNA copies of authentic WT SARS-CoV-2 in host cells by 4.6 orders of magnitude.Therefore,utilizing the aptamer selection method and the dedicated engineering route,our topology-matching DNA framework provides a versatile platform for SARS-CoV-2 inhibition and has the potential to be facilely expanded to newly emerging variants and other fatal coronaviruses.