Hongliang Zhang | Louisiana State University (original) (raw)
Papers by Hongliang Zhang
In this study, we characterized the structure and function of topoi- somerase I (top1) protein in... more In this study, we characterized the structure and function of topoi- somerase I (top1) protein in the camptothecin (CPT)-resistant prostate cancer cell lines, DU-145/RC0.1 and DU-145/RC1 (RC0.1 and RC1, re- spectively). Both of the cell lines were previously selected by continuous exposure to 9-nitro-CPT. The RC0.1 and RC1 cells have high cross- resistance to CPT derivatives including SN-38 and topotecan,
Atmospheric Environment, 2014
ABSTRACT Average PM2.5 concentrations of ∼250 μg m−3 and peak concentrations of ∼500 μg m−3 were ... more ABSTRACT Average PM2.5 concentrations of ∼250 μg m−3 and peak concentrations of ∼500 μg m−3 were observed in Xi'an, the largest city in Northwest China during an extreme event in January 2013. The source-oriented versions of the Community Multi-scale Air Quality (CMAQ) model with anthropogenic emissions from Emissions Database for Global Atmospheric Research (EDGAR) were used to study the source contributions of six different source categories including energy production, industries, transportation, residential activities, “other” (agriculture, biomass, waste burning, and biogenic sources), and windblown dust to primary and secondary inorganic PM2.5 (nitrate and sulfate) during this episode. The model generally captured the variation and magnitude of PM2.5 concentrations at monitoring sites. The monthly average concentration of the predicted PM2.5 in Xi'an was >200 μg m−3, comparing favorably with the measurement of ∼250 μg m−3. Predicted concentrations of elemental carbon (EC), organic aerosol (OA), sulfate, nitrate, and ammonium were 6, 35, 18, 22, and 12 μg m−3, respectively. Chemically unresolved PM2.5 components (PM2.5 Other) were ∼80 μg m−3. Industries and residential activities dominated EC, organic carbon (OC) and PM2.5 Other, contributing 85%, 95%, and 83%, respectively. Energy production (mainly coal combustion) was the dominating source for secondary nitrate, contributing 46%. Other local and upwind sources were also important, contributing 43% and 11% of total nitrate, respectively. Primary sulfate was ∼10 μg m−3 in vicinity surrounding point sources. Secondary sulfate from upwind sources was also important with concentrations of ∼4–5 μg m−3. Secondary sulfate formed by SO2 emitted from local sources was dominated by energy production. Based on the contributions of different sources to primary components and secondary nitrate and sulfate, the contributions of different sources to PM2.5 total mass in Xi'an during the extremely polluted months are: energy 5%, industries 58%, transportation 2%, residential activities 16%, dust 4%, and other (including other components, inexplicit sources, and upwind sources) 15%.
Atmospheric Environment, 2014
ABSTRACT
The Science of the total environment, Jan 3, 2015
A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fiel... more A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fields generated by the Weather Research and Forecasting (WRF) model was used to study the dry and wet deposition of nitrate (NO3(-)), sulfate (SO4(2-)), and ammonium (NH4(+)) ions in the Jiuzhaigou National Nature Reserve (JNNR), China from June to August 2010 and to identify the contributions of different emission sectors and source regions that were responsible for the deposition fluxes. Contributions from power plants, industry, transportation, domestic, biogenic, windblown dust, open burning, fertilizer, and manure management sources to deposition fluxes in JNNR watershed and four EANET sites are determined. In JNNR, 96%, 82%, and 87% of the SO4(2-), NO3(-) and NH4(+) deposition fluxes are in the form of wet deposition of the corresponding aerosol species. Industry and power plants are the two major sources of SO4(2-) deposition flux, accounting for 86% of the total wet deposition of SO...
TOP1MT -/-/ WT 0 0.5 1 1.5 ND2 COX1 myocard skeletal muscle Suppl. Fig.2. mtDNA transcript abunda... more TOP1MT -/-/ WT 0 0.5 1 1.5 ND2 COX1 myocard skeletal muscle Suppl. Fig.2. mtDNA transcript abundance in skeletal muscle and myocard of TOP1MT -/mice.
Environmental research, Jan 10, 2015
Meteorological conditions play a crucial role in ambient air pollution by affecting both directly... more Meteorological conditions play a crucial role in ambient air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. In this study, the relationships between meteorological parameters and ambient air pollutants concentrations in three megacities in China, Beijing, Shanghai, and Guangzhou were investigated. A systematic analysis of air pollutants including PM2.5, PM10, CO, SO2, NO2, and O3 and meteorological parameters including temperature, wind speed (WS), wind direction (WD) and relative humanity (RH) was conducted for a continuous period of 12 months from March 2013 to February 2014. The results show that all three cities experienced severe air quality problems. Clear seasonal trends were observed for PM2.5, PM10, CO, SO2 and NO2 with the maximum concentrations in the winter and the minimum in the summer, while O3 exhibited an opposite trend. Substantially different correlations between air pollutants and meteorol...
JAMA neurology, 2013
The classification and pathological mechanisms of many central nervous system inflammatory diseas... more The classification and pathological mechanisms of many central nervous system inflammatory diseases remain uncertain. In this article we report eight patients with a clinically and radiologically distinct pontine-predominant encephalomyelitis we have named 'chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids' (CLIPPERS). The patients were assessed clinically, radiologically and pathologically at Mayo Clinic, USA and Ghent University Hospital, Belgium from 1999 to 2009. Median follow-up duration from clinical onset was 22 months (range 7-144 months). Patients underwent extensive laboratory (serum and cerebrospinal fluid), radiological and pathological testing (conjunctival, transbronchial and brain biopsies) to search for causes of an inflammatory central nervous system disorder. All eight patients (five female, three male) presented with episodic diplopia or facial paresthesias with subsequent brainstem and occasionally myelopathic symptoms and had a favourable initial response to high dose glucocorticosteroids. All patients had symmetric curvilinear gadolinium enhancement peppering the pons and extending variably into the medulla, brachium pontis, cerebellum, midbrain and occasionally spinal cord. Radiological improvement accompanied clinical response to glucocorticosteroids. Patients routinely worsened following glucocorticosteroid taper and required chronic glucocorticosteroid or other immunosuppressive therapy. Neuropathology of biopsy material from four patients demonstrated white matter perivascular, predominantly T lymphocytic, infiltrate without granulomas, infection, lymphoma or vasculitis. Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids is a definable, chronic inflammatory central nervous system disorder amenable to immunosuppressive treatment. The T cell predominant inflammatory pathology in affected central nervous system lesions and the clinical and radiological response to immunosuppressive therapies is consistent with an immune-mediated process.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban, 2002
It is necessary to study the relationship between grasshopper and ecological factors for forecast... more It is necessary to study the relationship between grasshopper and ecological factors for forecasting grasshopper outbreak effectively. Temperature is one of main factors influencing grasshopper outbreak in the region around Qinghai Lake. With the support of Arc/Info and ArcView, monthly average temperatures were simulated under the scale of 150 m by data from sixteen meteorological stations adjacent to Qinghai Lake for adapting the comprehensive method and establishing spatial temperature database. Then, the relationship between grasshopper outbreak and monthly average temperature were analyzed by combining the spatial data of grasshopper density and the spatial data of monthly average temperature. The result showed that effects of monthly average temperature on Grasshopper outbreak were closely related to the life cycle of the dominant grasshopper species in the region, namely, monthly average temperatures of May, June, and July influenced grasshopper outbreak in the current year, ...
ABSTRACT The latest SAPRC photochemical mechanism SAPRC07 (S07), an update from SAPRC99 (S99), is... more ABSTRACT The latest SAPRC photochemical mechanism SAPRC07 (S07), an update from SAPRC99 (S99), is implemented into the Community Multi-scale Air Quality (CMAQ) model and applied to simulate a high ozone episode during the Texas Air Quality Study 2000 (TexAQS 2000). The results from the S07 mechanism are compared with those from the S99 mechanism. In general, the predicted O3 concentrations by S07 are lower than those of S99 with maximum difference as high as 20%. The two mechanisms also show significant differences in the predicted OH, HNO3, PAN and HCHO concentrations. S99 predicts higher OH concentration by 7–20%, higher PAN by approximately 20–25% and higher HCHO by approximately 15% than S07. OH budget analysis suggests that OH propagation factor (POH) is higher in urban and industrial areas but lower in rural areas. Although S07 generally predicts similar or higher POH, S99 predicts higher new OH formation rate from H2O + O(1D) and leads to higher OH and thus higher O3 in most part of the domain. OH reactions with VOCs and CO accounts for a majority part of reacted OH. Secondary VOCs photolysis is not a main path of regenerated OH. New OH mainly comes from H2O + O(1D) reaction. Although the two mechanisms predict different ozone concentrations, the relative response factor (RRF) of ozone at rural, urban and industrial sites under emission controls of anthropogenic NOx and VOC controls by factors 0.6–1.4 predicted by the two mechanisms are very similar. This suggests that although the absolute predictions are different, both models will provide nearly identical attainment assessment in regulatory applications.
Source apportionment is typically performed on chemical composition data derived from particulate... more Source apportionment is typically performed on chemical composition data derived from particulate matter (PM) samples. However, many common sources no longer emit significant amounts of characteristic trace elements requiring the use of more comprehensive chemical characterization in order to fully resolve the PM sources. Positive matrix factorization (EPA PMF, version 4.1) was used to analyze 24-hr integrated molecular marker (MM), secondary inorganic ions, trace elements, carbonaceous species and light absorption data to investigate sources of PM 2.5 in Rochester, New York between October 2009 and October 2010 to explore the role of specific MMs. An eight-factor solution was found for which the factors were identified as isoprene secondary organic aerosol (SOA), airborne soil, other SOA, diesel emissions, secondary sulfate, wood combustion, gasoline vehicle, and secondary nitrate contributing 6.9%, 12.8%, 3.7%, 7.8%, 45.5%, 9.1%, 7.9%, and 6.3% to the average PM 2.5 concentration, respectively Concentrations of pentacosane, hexacosane, heptacosane, and octacosane in the gasoline vehicles factor were larger compared to diesel emissions. Aethalometer Delta-C was strongly associated with wood combustion. The compounds, n-heptacosanoic acid and n-octacosanoic acid, occasionally used in the past as tracers for road dust, were found to largely associate with SOA in this study. In comparison with a standard PMF analyses without MM, inclusion of them was necessary to resolve SOA and wood combustion factors in urban areas.
The latest version of US EPA's Community Multi-scale Air Quality (CMAQ v4.7) model with the most ... more The latest version of US EPA's Community Multi-scale Air Quality (CMAQ v4.7) model with the most recent update on secondary organic aerosol (SOA) formation pathways was adapted into a sourceoriented modeling framework to determine the contributions of different emission sources to SOA concentrations from a carbon source perspective in Southeast Texas during the 2000 Texas Air Quality Study (TexAQS 2000) from August 25 to September 5, 2000. A comparison of the VOC and SOA predictions with observations shows that anthropogenic emissions of long chain alkanes and aromatics are likely underestimated in the EPA's Clean Air Interstate Rule (CAIR) inventory and the current SOA mechanism in CMAQ still under-predicts SOA. The peak SOA concentrations measured at La Porte are more accurately predicted by increasing the emissions of the anthropogenic SOA precursors by a factor of 5 although the overall precursor concentrations are better predicted by increasing the emissions by a factor of 2. A linear correlation between SOA and odd oxygen (DSOA/DO
Summertime PM 2.5 and PM 10 in the NCP and YRD regions of China were analyzed.
Long-term air pollution data with high temporal and spatial resolutions are needed to support the... more Long-term air pollution data with high temporal and spatial resolutions are needed to support the research of physical and chemical processes that affect the air quality, and the corresponding health risks. However, such datasets were not available in China until recently. For the first time, this study examines the spatial and temporal variations of PM 2.5 , PM 10 , CO, SO 2 , NO 2 , and 8 h O 3 in 31 capital cities in China between March 2013 and February 2014 using hourly data released by the Ministry of Environmental Protection (MEP) of China. The annual mean concentrations of PM 2.5 and PM 10 exceeded the Chinese Ambient Air Quality Standards (CAAQS), Grade I standards (15 and 40 μg/m 3 for PM 2.5 and PM 10 , respectively) for all cities, and only Haikou, Fuzhou and Lasa met the CAAQS Grade II standards (35 and 70 μg/m 3 for PM 2.5 and PM 10 , respectively). Observed PM 2.5 , PM 10 , CO and SO 2 concentrations were higher in cities located in the North region than those in the West and the South-East regions. The number of non-attainment days was highest in the winter, but high pollution days were also frequently observed in the South-East region during the fall and in the West region during the spring. PM 2.5 was the largest contributor to the air pollution in China based on the number of non-attainment days, followed by PM 10 , and O 3 . Strong correlation was found between different pollutants except for O 3 . These results suggest great impacts of coal combustion and biomass burning in the winter, long range transport of windblown dust in the spring, and secondary aerosol formation throughout the year. Current air pollution in China is caused by multiple pollutants, with great variations among different regions and different seasons. Future studies should focus on improving the understanding of the associations between air quality and meteorological conditions, variations of emissions in different regions, and transport and transformation of pollutants in both intra-and inter-regional contexts.
PloS one, 2014
MYB-type transcription factors (TFs) play essential roles in plant growth, development and respon... more MYB-type transcription factors (TFs) play essential roles in plant growth, development and respond to environmental stresses. Role of MYB-related TFs of rice in drought stress tolerance is not well documented. Here, we report the isolation and characterization of a novel MYB-related TF, OsMYB48-1, of rice. Expression of OsMYB48-1 was strongly induced by polyethylene glycol (PEG), abscisic acid (ABA), H2O2, and dehydration, while being slightly induced by high salinity and cold treatment. The OsMYB48-1 protein was localized in the nucleus with transactivation activity at the C terminus. Overexpression of OsMYB48-1 in rice significantly improved tolerance to simulated drought and salinity stresses caused by mannitol, PEG, and NaCl, respectively, and drought stress was caused by drying the soil. In contrast to wild type plants, the overexpression lines exhibited reduced rate of water loss, lower malondialdehyde (MDA) content and higher proline content under stress conditions. Moreover,...
Neural Regeneration Research, 2014
Critical illness polyneuropathy and critical illness myopathy are frequent complications of sever... more Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitating neurological disease.
PLoS ONE, 2012
Background: Mitochondria contain their own DNA genome (mtDNA), as well as specific DNA replicatio... more Background: Mitochondria contain their own DNA genome (mtDNA), as well as specific DNA replication and protein synthesis machineries. Relaxation of the circular, double-stranded mtDNA relies on the presence of topoisomerase activity. Three different topoisomerases have been identified in mitochondria: Top1mt, Top3a and a truncated form of Top2b.
In this study, we characterized the structure and function of topoi- somerase I (top1) protein in... more In this study, we characterized the structure and function of topoi- somerase I (top1) protein in the camptothecin (CPT)-resistant prostate cancer cell lines, DU-145/RC0.1 and DU-145/RC1 (RC0.1 and RC1, re- spectively). Both of the cell lines were previously selected by continuous exposure to 9-nitro-CPT. The RC0.1 and RC1 cells have high cross- resistance to CPT derivatives including SN-38 and topotecan,
Atmospheric Environment, 2014
ABSTRACT Average PM2.5 concentrations of ∼250 μg m−3 and peak concentrations of ∼500 μg m−3 were ... more ABSTRACT Average PM2.5 concentrations of ∼250 μg m−3 and peak concentrations of ∼500 μg m−3 were observed in Xi'an, the largest city in Northwest China during an extreme event in January 2013. The source-oriented versions of the Community Multi-scale Air Quality (CMAQ) model with anthropogenic emissions from Emissions Database for Global Atmospheric Research (EDGAR) were used to study the source contributions of six different source categories including energy production, industries, transportation, residential activities, “other” (agriculture, biomass, waste burning, and biogenic sources), and windblown dust to primary and secondary inorganic PM2.5 (nitrate and sulfate) during this episode. The model generally captured the variation and magnitude of PM2.5 concentrations at monitoring sites. The monthly average concentration of the predicted PM2.5 in Xi'an was >200 μg m−3, comparing favorably with the measurement of ∼250 μg m−3. Predicted concentrations of elemental carbon (EC), organic aerosol (OA), sulfate, nitrate, and ammonium were 6, 35, 18, 22, and 12 μg m−3, respectively. Chemically unresolved PM2.5 components (PM2.5 Other) were ∼80 μg m−3. Industries and residential activities dominated EC, organic carbon (OC) and PM2.5 Other, contributing 85%, 95%, and 83%, respectively. Energy production (mainly coal combustion) was the dominating source for secondary nitrate, contributing 46%. Other local and upwind sources were also important, contributing 43% and 11% of total nitrate, respectively. Primary sulfate was ∼10 μg m−3 in vicinity surrounding point sources. Secondary sulfate from upwind sources was also important with concentrations of ∼4–5 μg m−3. Secondary sulfate formed by SO2 emitted from local sources was dominated by energy production. Based on the contributions of different sources to primary components and secondary nitrate and sulfate, the contributions of different sources to PM2.5 total mass in Xi'an during the extremely polluted months are: energy 5%, industries 58%, transportation 2%, residential activities 16%, dust 4%, and other (including other components, inexplicit sources, and upwind sources) 15%.
Atmospheric Environment, 2014
ABSTRACT
The Science of the total environment, Jan 3, 2015
A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fiel... more A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fields generated by the Weather Research and Forecasting (WRF) model was used to study the dry and wet deposition of nitrate (NO3(-)), sulfate (SO4(2-)), and ammonium (NH4(+)) ions in the Jiuzhaigou National Nature Reserve (JNNR), China from June to August 2010 and to identify the contributions of different emission sectors and source regions that were responsible for the deposition fluxes. Contributions from power plants, industry, transportation, domestic, biogenic, windblown dust, open burning, fertilizer, and manure management sources to deposition fluxes in JNNR watershed and four EANET sites are determined. In JNNR, 96%, 82%, and 87% of the SO4(2-), NO3(-) and NH4(+) deposition fluxes are in the form of wet deposition of the corresponding aerosol species. Industry and power plants are the two major sources of SO4(2-) deposition flux, accounting for 86% of the total wet deposition of SO...
TOP1MT -/-/ WT 0 0.5 1 1.5 ND2 COX1 myocard skeletal muscle Suppl. Fig.2. mtDNA transcript abunda... more TOP1MT -/-/ WT 0 0.5 1 1.5 ND2 COX1 myocard skeletal muscle Suppl. Fig.2. mtDNA transcript abundance in skeletal muscle and myocard of TOP1MT -/mice.
Environmental research, Jan 10, 2015
Meteorological conditions play a crucial role in ambient air pollution by affecting both directly... more Meteorological conditions play a crucial role in ambient air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. In this study, the relationships between meteorological parameters and ambient air pollutants concentrations in three megacities in China, Beijing, Shanghai, and Guangzhou were investigated. A systematic analysis of air pollutants including PM2.5, PM10, CO, SO2, NO2, and O3 and meteorological parameters including temperature, wind speed (WS), wind direction (WD) and relative humanity (RH) was conducted for a continuous period of 12 months from March 2013 to February 2014. The results show that all three cities experienced severe air quality problems. Clear seasonal trends were observed for PM2.5, PM10, CO, SO2 and NO2 with the maximum concentrations in the winter and the minimum in the summer, while O3 exhibited an opposite trend. Substantially different correlations between air pollutants and meteorol...
JAMA neurology, 2013
The classification and pathological mechanisms of many central nervous system inflammatory diseas... more The classification and pathological mechanisms of many central nervous system inflammatory diseases remain uncertain. In this article we report eight patients with a clinically and radiologically distinct pontine-predominant encephalomyelitis we have named 'chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids' (CLIPPERS). The patients were assessed clinically, radiologically and pathologically at Mayo Clinic, USA and Ghent University Hospital, Belgium from 1999 to 2009. Median follow-up duration from clinical onset was 22 months (range 7-144 months). Patients underwent extensive laboratory (serum and cerebrospinal fluid), radiological and pathological testing (conjunctival, transbronchial and brain biopsies) to search for causes of an inflammatory central nervous system disorder. All eight patients (five female, three male) presented with episodic diplopia or facial paresthesias with subsequent brainstem and occasionally myelopathic symptoms and had a favourable initial response to high dose glucocorticosteroids. All patients had symmetric curvilinear gadolinium enhancement peppering the pons and extending variably into the medulla, brachium pontis, cerebellum, midbrain and occasionally spinal cord. Radiological improvement accompanied clinical response to glucocorticosteroids. Patients routinely worsened following glucocorticosteroid taper and required chronic glucocorticosteroid or other immunosuppressive therapy. Neuropathology of biopsy material from four patients demonstrated white matter perivascular, predominantly T lymphocytic, infiltrate without granulomas, infection, lymphoma or vasculitis. Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids is a definable, chronic inflammatory central nervous system disorder amenable to immunosuppressive treatment. The T cell predominant inflammatory pathology in affected central nervous system lesions and the clinical and radiological response to immunosuppressive therapies is consistent with an immune-mediated process.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban, 2002
It is necessary to study the relationship between grasshopper and ecological factors for forecast... more It is necessary to study the relationship between grasshopper and ecological factors for forecasting grasshopper outbreak effectively. Temperature is one of main factors influencing grasshopper outbreak in the region around Qinghai Lake. With the support of Arc/Info and ArcView, monthly average temperatures were simulated under the scale of 150 m by data from sixteen meteorological stations adjacent to Qinghai Lake for adapting the comprehensive method and establishing spatial temperature database. Then, the relationship between grasshopper outbreak and monthly average temperature were analyzed by combining the spatial data of grasshopper density and the spatial data of monthly average temperature. The result showed that effects of monthly average temperature on Grasshopper outbreak were closely related to the life cycle of the dominant grasshopper species in the region, namely, monthly average temperatures of May, June, and July influenced grasshopper outbreak in the current year, ...
ABSTRACT The latest SAPRC photochemical mechanism SAPRC07 (S07), an update from SAPRC99 (S99), is... more ABSTRACT The latest SAPRC photochemical mechanism SAPRC07 (S07), an update from SAPRC99 (S99), is implemented into the Community Multi-scale Air Quality (CMAQ) model and applied to simulate a high ozone episode during the Texas Air Quality Study 2000 (TexAQS 2000). The results from the S07 mechanism are compared with those from the S99 mechanism. In general, the predicted O3 concentrations by S07 are lower than those of S99 with maximum difference as high as 20%. The two mechanisms also show significant differences in the predicted OH, HNO3, PAN and HCHO concentrations. S99 predicts higher OH concentration by 7–20%, higher PAN by approximately 20–25% and higher HCHO by approximately 15% than S07. OH budget analysis suggests that OH propagation factor (POH) is higher in urban and industrial areas but lower in rural areas. Although S07 generally predicts similar or higher POH, S99 predicts higher new OH formation rate from H2O + O(1D) and leads to higher OH and thus higher O3 in most part of the domain. OH reactions with VOCs and CO accounts for a majority part of reacted OH. Secondary VOCs photolysis is not a main path of regenerated OH. New OH mainly comes from H2O + O(1D) reaction. Although the two mechanisms predict different ozone concentrations, the relative response factor (RRF) of ozone at rural, urban and industrial sites under emission controls of anthropogenic NOx and VOC controls by factors 0.6–1.4 predicted by the two mechanisms are very similar. This suggests that although the absolute predictions are different, both models will provide nearly identical attainment assessment in regulatory applications.
Source apportionment is typically performed on chemical composition data derived from particulate... more Source apportionment is typically performed on chemical composition data derived from particulate matter (PM) samples. However, many common sources no longer emit significant amounts of characteristic trace elements requiring the use of more comprehensive chemical characterization in order to fully resolve the PM sources. Positive matrix factorization (EPA PMF, version 4.1) was used to analyze 24-hr integrated molecular marker (MM), secondary inorganic ions, trace elements, carbonaceous species and light absorption data to investigate sources of PM 2.5 in Rochester, New York between October 2009 and October 2010 to explore the role of specific MMs. An eight-factor solution was found for which the factors were identified as isoprene secondary organic aerosol (SOA), airborne soil, other SOA, diesel emissions, secondary sulfate, wood combustion, gasoline vehicle, and secondary nitrate contributing 6.9%, 12.8%, 3.7%, 7.8%, 45.5%, 9.1%, 7.9%, and 6.3% to the average PM 2.5 concentration, respectively Concentrations of pentacosane, hexacosane, heptacosane, and octacosane in the gasoline vehicles factor were larger compared to diesel emissions. Aethalometer Delta-C was strongly associated with wood combustion. The compounds, n-heptacosanoic acid and n-octacosanoic acid, occasionally used in the past as tracers for road dust, were found to largely associate with SOA in this study. In comparison with a standard PMF analyses without MM, inclusion of them was necessary to resolve SOA and wood combustion factors in urban areas.
The latest version of US EPA's Community Multi-scale Air Quality (CMAQ v4.7) model with the most ... more The latest version of US EPA's Community Multi-scale Air Quality (CMAQ v4.7) model with the most recent update on secondary organic aerosol (SOA) formation pathways was adapted into a sourceoriented modeling framework to determine the contributions of different emission sources to SOA concentrations from a carbon source perspective in Southeast Texas during the 2000 Texas Air Quality Study (TexAQS 2000) from August 25 to September 5, 2000. A comparison of the VOC and SOA predictions with observations shows that anthropogenic emissions of long chain alkanes and aromatics are likely underestimated in the EPA's Clean Air Interstate Rule (CAIR) inventory and the current SOA mechanism in CMAQ still under-predicts SOA. The peak SOA concentrations measured at La Porte are more accurately predicted by increasing the emissions of the anthropogenic SOA precursors by a factor of 5 although the overall precursor concentrations are better predicted by increasing the emissions by a factor of 2. A linear correlation between SOA and odd oxygen (DSOA/DO
Summertime PM 2.5 and PM 10 in the NCP and YRD regions of China were analyzed.
Long-term air pollution data with high temporal and spatial resolutions are needed to support the... more Long-term air pollution data with high temporal and spatial resolutions are needed to support the research of physical and chemical processes that affect the air quality, and the corresponding health risks. However, such datasets were not available in China until recently. For the first time, this study examines the spatial and temporal variations of PM 2.5 , PM 10 , CO, SO 2 , NO 2 , and 8 h O 3 in 31 capital cities in China between March 2013 and February 2014 using hourly data released by the Ministry of Environmental Protection (MEP) of China. The annual mean concentrations of PM 2.5 and PM 10 exceeded the Chinese Ambient Air Quality Standards (CAAQS), Grade I standards (15 and 40 μg/m 3 for PM 2.5 and PM 10 , respectively) for all cities, and only Haikou, Fuzhou and Lasa met the CAAQS Grade II standards (35 and 70 μg/m 3 for PM 2.5 and PM 10 , respectively). Observed PM 2.5 , PM 10 , CO and SO 2 concentrations were higher in cities located in the North region than those in the West and the South-East regions. The number of non-attainment days was highest in the winter, but high pollution days were also frequently observed in the South-East region during the fall and in the West region during the spring. PM 2.5 was the largest contributor to the air pollution in China based on the number of non-attainment days, followed by PM 10 , and O 3 . Strong correlation was found between different pollutants except for O 3 . These results suggest great impacts of coal combustion and biomass burning in the winter, long range transport of windblown dust in the spring, and secondary aerosol formation throughout the year. Current air pollution in China is caused by multiple pollutants, with great variations among different regions and different seasons. Future studies should focus on improving the understanding of the associations between air quality and meteorological conditions, variations of emissions in different regions, and transport and transformation of pollutants in both intra-and inter-regional contexts.
PloS one, 2014
MYB-type transcription factors (TFs) play essential roles in plant growth, development and respon... more MYB-type transcription factors (TFs) play essential roles in plant growth, development and respond to environmental stresses. Role of MYB-related TFs of rice in drought stress tolerance is not well documented. Here, we report the isolation and characterization of a novel MYB-related TF, OsMYB48-1, of rice. Expression of OsMYB48-1 was strongly induced by polyethylene glycol (PEG), abscisic acid (ABA), H2O2, and dehydration, while being slightly induced by high salinity and cold treatment. The OsMYB48-1 protein was localized in the nucleus with transactivation activity at the C terminus. Overexpression of OsMYB48-1 in rice significantly improved tolerance to simulated drought and salinity stresses caused by mannitol, PEG, and NaCl, respectively, and drought stress was caused by drying the soil. In contrast to wild type plants, the overexpression lines exhibited reduced rate of water loss, lower malondialdehyde (MDA) content and higher proline content under stress conditions. Moreover,...
Neural Regeneration Research, 2014
Critical illness polyneuropathy and critical illness myopathy are frequent complications of sever... more Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitating neurological disease.
PLoS ONE, 2012
Background: Mitochondria contain their own DNA genome (mtDNA), as well as specific DNA replicatio... more Background: Mitochondria contain their own DNA genome (mtDNA), as well as specific DNA replication and protein synthesis machineries. Relaxation of the circular, double-stranded mtDNA relies on the presence of topoisomerase activity. Three different topoisomerases have been identified in mitochondria: Top1mt, Top3a and a truncated form of Top2b.