This commentary is based on a series of recent lectures on aerosol-monsoon interactions I gave at the Beijing Normal University in August 2015. A main theme of the lectures is on a new paradigm of "An Aerosol-Monsoon...This commentary is based on a series of recent lectures on aerosol-monsoon interactions I gave at the Beijing Normal University in August 2015. A main theme of the lectures is on a new paradigm of "An Aerosol-Monsoon-Climate-System", which posits that aerosol, like rainfall, cloud, and wind, is an integral component of the monsoon climate system, influencing monsoon weather and climate on M1 timescales. Here, salient issues discussed in my lectures and my personal perspective regarding interactions between atmospheric dynamics and aerosols from both natural and anthropogenic sources are summarized. My hope is that under this new paradigm, we can break down traditional disciplinary barriers, advance a deeper understanding of weather and climate in monsoon regions, as well as entrain a new generation of geoscientists to strive for a sustainable future for one of the most complex and challenging human-natural climate sub-system of the earth.展开更多
The use of Ni-rich TiNiHf alloys as high temperature shape memory alloys (SMAs) through aging has been presented. For Ni-rich Ti80-xNixHf20 alloys, their phase transformation temperatures are averagely increased mor...The use of Ni-rich TiNiHf alloys as high temperature shape memory alloys (SMAs) through aging has been presented. For Ni-rich Ti80-xNixHf20 alloys, their phase transformation temperatures are averagely increased more than 100 K by aging at 823 K for 2 h. Especially for the alloys with Ni-content of 50.4 at. pct and 50.6 at. pct, their martensitic transformation start temperatures (Ms) are more than 473 K after aging. TEM observation confirmed that some fine particles precipitate from the matrix during aging. The aged Ni-rich TiNiHf SMAs show the better thermal stability of phase transformation temperatures than the solutiontreated TiNiHf alloys. The fine particles precipitated during aging should be responsible for the increase of phase transformation temperatures and its high stability.展开更多
The Effect of the thermal cycling training under constant strain on the two-way shape memory effect (TWSME) in a Ti36l\li49Hf15 high temperature shape memory alloy (SMA) has been investigated by bending tests. The res...The Effect of the thermal cycling training under constant strain on the two-way shape memory effect (TWSME) in a Ti36l\li49Hf15 high temperature shape memory alloy (SMA) has been investigated by bending tests. The results indicated that the training procedure is beneficial to get the better TWSME. The two-way shape memory strain increases with increasing the training strain. And it decreases with increasing the training temperature. The TWSME obtained in the present alloy shows poorer stability compared with that obtained in the TiNi alloys.展开更多
The structural property of GaSb epilayers grown on semi-insulator GaAs (001) substrate by metalorganic chemical vapor deposition (MOCVD) using Triethylgallium (TEGa) and trimethylantimony (TMSb), was investiga...The structural property of GaSb epilayers grown on semi-insulator GaAs (001) substrate by metalorganic chemical vapor deposition (MOCVD) using Triethylgallium (TEGa) and trimethylantimony (TMSb), was investigated by variation of the Sb:Ga (V/Ill) ratio. An optimum V/Ill ratio of 1.4 was determined in our growth conditions. Using transmission electron microscopy (TEM), we found that there was an interracial misfit dislocations (IMF) growth mode in our experiment, in which the large misfit strain between epilayer and substrate is relaxed by periodic 90 deg. IMF array at the hetero-epitaxial interface. The rms roughness of a 300 nm-thick GaSb layer is only 2.7 nm in a 10μm×10μm scan from atomic force microscopy (AFM) result. The best hole density and mobility of 300 nm GaSb epilayer are 5.27xi06 cm-3(1.20×106) and 553 cm2-V-l.s-1 (2340) at RT (77 K) from Hall measurement, respectively. These results indicate that the IMF growth mode can be used in MOCVD epitaxial technology similar to molecular beam epitaxy (MBE) technology to produce the thinner GaSb layer with low density of dislocations and other defects on GaAs substrate for the application of devices.展开更多
Analysis is performed of the May-September mean circulation,referred to as the background circulation hereinafter,in the IAP(Institute of Atmospheric Physics,Academia Sinica)GCM model atmosphere,It is found that in an...Analysis is performed of the May-September mean circulation,referred to as the background circulation hereinafter,in the IAP(Institute of Atmospheric Physics,Academia Sinica)GCM model atmosphere,It is found that in an El Nino year there occur anomalies in a set of major systems,e.g.,Southetm Oscillation,Walker and Hadley circulations,the western Pacific subtropical high and ITCZ,2nd in large-scale precipitation,with their happening dominantly in the Northern Hemisphere tropical and subtropical latitudes in the western Pacific. These results that are in rough agreement with the analyzd actual observations demonstrate the applicabilities of the model to the study of low-latitude circulations.展开更多
Light absorbing particles(LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric...Light absorbing particles(LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance(a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice(LAPSI) has been identified as one of major forcings affecting climate change, e.g.in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, and climatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.展开更多
The direct correlation between NASA MODIS aerosol optical depth (AOD) products and the air pollution index (API) in Beijing was found relatively low based on the long-term comparison analysis. The correlation improved...The direct correlation between NASA MODIS aerosol optical depth (AOD) products and the air pollution index (API) in Beijing was found relatively low based on the long-term comparison analysis. The correlation improved to some extent after taking account of the seasonal variation of scale height and the vertical distribution of aerosols. The correlation coefficient further improved significantly after considering the influencing factor of Relative Humidity (RH). This study concluded that satellite remote-sensing could serve as an efficient tool for monitoring the spatial distribution of particulate pollutants on the ground-level, as long as corrections have been made in the two aforementioned processes. Taking advantage of the MODIS information, we analyzed a pollution episode occurring in October 2004 in Beijing. It indicated that satellite remote-sensing could describe the formation process of the ground-level pollution episode in detail, and showed that regional transport and the topography were crucial factors to air quality in Beijing. The annual averaged distribution in the urban area of Beijing and its surroundings could be also obtained from the high-resolution retrieval results, implicating that high-resolution satellite remote-sensing might be potential in monitoring the source distribution of particulate pollutants.展开更多
We conducted a six-year epidemiological study on human coronaviruses(HCoVs) circulating in Hong Kong, using 8275 nasopharyngeal samples from patients with acute respiratory tract infections. HCoVs were detected in 7...We conducted a six-year epidemiological study on human coronaviruses(HCoVs) circulating in Hong Kong, using 8275 nasopharyngeal samples from patients with acute respiratory tract infections. HCoVs were detected in 77(0.93%) of the samples by a pan-HCoV RT-PCR assay. The most frequently detected HCoV species was HCoV-OC43(0.58%), followed by HCoV-229E(0.15%),HCoV-HKU1(0.13%) and HCoV-NL63(0.07%). HCoVs were detected throughout the study period(September 2008–August 2014), with the highest detection rate from September 2010 to August2011(22/1500, 1.47%). Different seasonal patterns of each HCoV species in Hong Kong were noted.HCoV-OC43 was predominant in the fall and winter, whereas HCoV-HKU1 showed peak activity in winter, with a few cases occurred in spring and summer. HCoV-229 E mainly occurred in winter and spring, while HCoV-NL63 was predominant in summer and autumn. HCoVs most commonly infect the elderly and young children, with median age of 79.5 years(range, 22 days to 95 years).Intriguingly, the detection rate of HCoV-OC43 in the age group of > 80 years(26/2380, 1.09%) was significantly higher than that in the age group of 0–10 years(12/2529, 0.47%)(P 〈 0.05). These data provides new insight into the epidemiology of coronaviruses.展开更多
Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) concentration.Given the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollu...Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) concentration.Given the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollution controls can be ambiguous when the assessments focus on the changes in pollutant concentrations.In this study,a risk-based method was used to gauge the net effect of air pollution controls on mortality risk in the Beijing–Tianjin–Hebei(BTH)region during the 2022 Winter Olympics and Paralympics(WOP).This mega-event presents a unique opportunity to investigate the efficacy of deep cuts in pollutant emissions.Results show that O_(3) concentrations greatly increased as nitrogen dioxide(NO_(2))concentrations decreased in the BTH.Due to the active photochemical formations,O_(3) became the dominant pollutant that affected human health during the WOP.Despite the substantial O_(3) increases,the health benefits of NO_(2) reductions overwhelmed the adverse health effects of O_(3) increases in most regions of the BTH(at 81 out of 112 stations).After considering the impacts of particulate matter,the integrated health risk of air pollution mixtures declined almost everywhere in the BTH.Our results underscore the great necessity of changing the assessment paradigm of pollution control from using concentration-based methods to using risk-based methods.Together with the carbon neutrality policy,stringent control of NO_(x)emission from combustion sources is a promising way to achieve synergistic control solutions for air pollution and climate change.展开更多
Partial discharges(PDs) due to artificial void in samples of LDPE nanocomposite sheet have been investigated in this work.PDs may cause the degradation of insulating materials and may affect the lifetime of high-volta...Partial discharges(PDs) due to artificial void in samples of LDPE nanocomposite sheet have been investigated in this work.PDs may cause the degradation of insulating materials and may affect the lifetime of high-voltage apparatus. An experimental work using sphere ball-plane electrode system(CIGRE MethodⅡ) and a 1.0 mm LDPE composite sheet was carried out.Different weight percentages of nanosilica(0%,2%,4%,6%and 8%) were used. PD experimental results,such as PD magnitude and PD number(both PD pulse polarities),as functions of the applied stress duration at a specified applied voltage were compared.The surface morphology of specimens was also presented and this conforms to the PD findings.The experimental results show that the PD characteristics of the LDPE generally improve with the introduction of nanosilica,the composite with the highest content of filler,namely the 8%(wt) nanosilica sample has the least partial discharge activities.展开更多
Two-dimensional gel electrophoresis(2-DE)is a gel-based technique widely used for analyzing the pro-tein composition of biological samples.It is capable of resolving complex mixtures containing more than a thousand pr...Two-dimensional gel electrophoresis(2-DE)is a gel-based technique widely used for analyzing the pro-tein composition of biological samples.It is capable of resolving complex mixtures containing more than a thousand protein components into individual protein spots through the coupling of two orthogonal bio-physical separation techniques:isoelectric focusing(first dimension)and polyacrylamide gel electrophore-sis(second dimension).2-DE is ideally suited for ana-lyzing the entire expressed protein complement of a bacterial cell:its proteome.Its relative simplicity and good reproducibility have led to 2-DE being widely used for exploring proteomics within a wide range of envi-ronmental and medically-relevant bacteria.Here we give a broad overview of the basic principles and his-torical development of gel-based proteomics,and how this powerful approach can be applied for studying bacterial biology and physiology.We highlight specific 2-DE applications that can be used to analyze when,where and how much proteins are expressed.The links between proteomics,genomics and mass spectrometry are discussed.We explore how proteomics involving tandem mass spectrometry can be used to analyze(post-translational)protein modifications or to identify proteins of unknown origin by de novo peptide se-quencing.The use of proteome fractionation tech-niques and non-gel-based proteomic approaches are also discussed.We highlight how the analysis of pro-teins secreted by bacterial cells(secretomes or exo-proteomes)can be used to study infection processes or the immune response.This review is aimed at non-specialists who wish to gain a concise,compre-hensive and contemporary overview of the nature and applications of bacterial proteomics.展开更多
Although various opportunistic infections have been described in patients with anti-interferon gamma autoantibodies,so far there is no Listeria monocytogenes infection reported to be associated with this primary immun...Although various opportunistic infections have been described in patients with anti-interferon gamma autoantibodies,so far there is no Listeria monocytogenes infection reported to be associated with this primary immunodeficiency.Here,we describe the first case of bacteremic L.monocytogenes meningitis in a 59-year-old Chinese man with anti-interferon gamma autoantibodies,who presented with acute onset of fever and severe headache.Blood culture was positive but culture of the cerebrospinal fluid was negative,although it showed features suggestive of partially treated bacterial meningitis.The presence of L.monocytogenes in the cerebrospinal fluid was confirmed by next-generation sequencing.Avoidance of high-risk food items in these patients is important for the prevention of listeriosis.The use of antibiotic regimens that cover Listeria is crucial for empirical treatment,particularly if such patients develop acute or subacute meningitis.Next-generation sequencing is becoming an important diagnostic modality for culture-negative infections.展开更多
In this paper,we develop an orthogonal frequency-division multiplexing(OFDM)-based over-theair(OTA)aggregation solution for wireless federated learning(FL).In particular,the local gradients in massive Internet of thin...In this paper,we develop an orthogonal frequency-division multiplexing(OFDM)-based over-theair(OTA)aggregation solution for wireless federated learning(FL).In particular,the local gradients in massive Internet of things(IoT)devices are modulated by an analog waveform and are then transmitted using the same wireless resources.To this end,achieving perfect waveform superposition is the key challenge,which is difficult due to the existence of frame timing offset(TO)and carrier frequency offset(CFO).In order to address these issues,we propose a two-stage waveform pre-equalization technique with a customized multiple access protocol that can estimate and then mitigate the TO and CFO for the OTA aggregation.Based on the proposed solution,we develop a hardware transceiver and application software to train a real-world FL task,which learns a deep neural network to predict the received signal strength with the global positioning system information.Experiments verify that the proposed OTA aggregation solution can achieve comparable performance to offline learning procedures with high prediction accuracy.展开更多
Introduction Target therapies are widely used for treatment of various kinds of hematological malignancies.Since the cancer cells that are targeted,share the same markers with the non-cancerous cells of the immunologi...Introduction Target therapies are widely used for treatment of various kinds of hematological malignancies.Since the cancer cells that are targeted,share the same markers with the non-cancerous cells of the immunological system,these therapies are often associated with infectious diseases that require the particular type of immune response for control.In this article,we report a case of Listeria monocytogenes bacteraemia complicating carfilzomib and daratumumab treatment for multiple myeloma.To the best of our knowledge,this is the first case report of listeriosis as a complication of monoclonal antibodies against CD38 and/or proteosome inhibitor therapy.展开更多
基金Supported jointly by the US Department of Energy,Pacific Northwest National Laboratory(4331620),Earth System Science Interdisciplinary Center,University of Maryland,Department of Atmospheric SciencesTexas A&M University
文摘This commentary is based on a series of recent lectures on aerosol-monsoon interactions I gave at the Beijing Normal University in August 2015. A main theme of the lectures is on a new paradigm of "An Aerosol-Monsoon-Climate-System", which posits that aerosol, like rainfall, cloud, and wind, is an integral component of the monsoon climate system, influencing monsoon weather and climate on M1 timescales. Here, salient issues discussed in my lectures and my personal perspective regarding interactions between atmospheric dynamics and aerosols from both natural and anthropogenic sources are summarized. My hope is that under this new paradigm, we can break down traditional disciplinary barriers, advance a deeper understanding of weather and climate in monsoon regions, as well as entrain a new generation of geoscientists to strive for a sustainable future for one of the most complex and challenging human-natural climate sub-system of the earth.
文摘The use of Ni-rich TiNiHf alloys as high temperature shape memory alloys (SMAs) through aging has been presented. For Ni-rich Ti80-xNixHf20 alloys, their phase transformation temperatures are averagely increased more than 100 K by aging at 823 K for 2 h. Especially for the alloys with Ni-content of 50.4 at. pct and 50.6 at. pct, their martensitic transformation start temperatures (Ms) are more than 473 K after aging. TEM observation confirmed that some fine particles precipitate from the matrix during aging. The aged Ni-rich TiNiHf SMAs show the better thermal stability of phase transformation temperatures than the solutiontreated TiNiHf alloys. The fine particles precipitated during aging should be responsible for the increase of phase transformation temperatures and its high stability.
文摘The Effect of the thermal cycling training under constant strain on the two-way shape memory effect (TWSME) in a Ti36l\li49Hf15 high temperature shape memory alloy (SMA) has been investigated by bending tests. The results indicated that the training procedure is beneficial to get the better TWSME. The two-way shape memory strain increases with increasing the training strain. And it decreases with increasing the training temperature. The TWSME obtained in the present alloy shows poorer stability compared with that obtained in the TiNi alloys.
基金supported by the National Natural Science Foundation of China(Grant Nos.51071038and60576007)Program for New Century Excellent Talents in University(NCET-09-0265)the Sichuan Province Science Foundation for Youths(No.2010JQ0002)
文摘The structural property of GaSb epilayers grown on semi-insulator GaAs (001) substrate by metalorganic chemical vapor deposition (MOCVD) using Triethylgallium (TEGa) and trimethylantimony (TMSb), was investigated by variation of the Sb:Ga (V/Ill) ratio. An optimum V/Ill ratio of 1.4 was determined in our growth conditions. Using transmission electron microscopy (TEM), we found that there was an interracial misfit dislocations (IMF) growth mode in our experiment, in which the large misfit strain between epilayer and substrate is relaxed by periodic 90 deg. IMF array at the hetero-epitaxial interface. The rms roughness of a 300 nm-thick GaSb layer is only 2.7 nm in a 10μm×10μm scan from atomic force microscopy (AFM) result. The best hole density and mobility of 300 nm GaSb epilayer are 5.27xi06 cm-3(1.20×106) and 553 cm2-V-l.s-1 (2340) at RT (77 K) from Hall measurement, respectively. These results indicate that the IMF growth mode can be used in MOCVD epitaxial technology similar to molecular beam epitaxy (MBE) technology to produce the thinner GaSb layer with low density of dislocations and other defects on GaAs substrate for the application of devices.
文摘Analysis is performed of the May-September mean circulation,referred to as the background circulation hereinafter,in the IAP(Institute of Atmospheric Physics,Academia Sinica)GCM model atmosphere,It is found that in an El Nino year there occur anomalies in a set of major systems,e.g.,Southetm Oscillation,Walker and Hadley circulations,the western Pacific subtropical high and ITCZ,2nd in large-scale precipitation,with their happening dominantly in the Northern Hemisphere tropical and subtropical latitudes in the western Pacific. These results that are in rough agreement with the analyzd actual observations demonstrate the applicabilities of the model to the study of low-latitude circulations.
基金supported by the U.S.Department of Energy, Office of Science, Biological and Environmental Research, as part of the Earth System Modeling ProgramThe NASA Modeling, Analysis, and Prediction (MAP) Program by the Science Mission Directorate at NASA Headquarters supported the work contributed by Teppei J.YASUNARI and William K.M.LAU+2 种基金The NASA GEOS-5 simulation was implemented in the system for NASA Center for Climate Simulation (NCCS).M.G.Flanner was partially supported by NSF 1253154support from the China Scholarship FundThe Pacific Northwest National Laboratory is operated for DOE by Battelle Memorial Institute under contract DE-AC06-76RLO1830
文摘Light absorbing particles(LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance(a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice(LAPSI) has been identified as one of major forcings affecting climate change, e.g.in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, and climatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.
基金The MODIS data used in this study were acquired as part of the NASA's Earth-Sun System Division,and archived and distributed by the Goddard Earth Sciences(GES)Data and Information Services Center(DISC)Distributed Active Archive Center(DAAC).This work was supported by the National Key Basic Research Program("973"Projects)of China(Grant No.TG1999045700)the National Natural Science Foundation of China(NSFC)+2 种基金Research Grant Council(RGC)of Hong Kong(Grant Nos.NSFC/HKUST 36 and N_HKUST630/04)the NSFC(Grant No.90211001)the Ministry of Science and Technology of China(Grant No.2004 DFA06100).
文摘The direct correlation between NASA MODIS aerosol optical depth (AOD) products and the air pollution index (API) in Beijing was found relatively low based on the long-term comparison analysis. The correlation improved to some extent after taking account of the seasonal variation of scale height and the vertical distribution of aerosols. The correlation coefficient further improved significantly after considering the influencing factor of Relative Humidity (RH). This study concluded that satellite remote-sensing could serve as an efficient tool for monitoring the spatial distribution of particulate pollutants on the ground-level, as long as corrections have been made in the two aforementioned processes. Taking advantage of the MODIS information, we analyzed a pollution episode occurring in October 2004 in Beijing. It indicated that satellite remote-sensing could describe the formation process of the ground-level pollution episode in detail, and showed that regional transport and the topography were crucial factors to air quality in Beijing. The annual averaged distribution in the urban area of Beijing and its surroundings could be also obtained from the high-resolution retrieval results, implicating that high-resolution satellite remote-sensing might be potential in monitoring the source distribution of particulate pollutants.
基金partly supported by the Theme-Based Research Scheme, University Grant CouncilStrategic Research Theme Fund and University Development Fund, The University of Hong KongHealth and Medical Research Fund of the Food and Health Bureau of HKSAR
文摘We conducted a six-year epidemiological study on human coronaviruses(HCoVs) circulating in Hong Kong, using 8275 nasopharyngeal samples from patients with acute respiratory tract infections. HCoVs were detected in 77(0.93%) of the samples by a pan-HCoV RT-PCR assay. The most frequently detected HCoV species was HCoV-OC43(0.58%), followed by HCoV-229E(0.15%),HCoV-HKU1(0.13%) and HCoV-NL63(0.07%). HCoVs were detected throughout the study period(September 2008–August 2014), with the highest detection rate from September 2010 to August2011(22/1500, 1.47%). Different seasonal patterns of each HCoV species in Hong Kong were noted.HCoV-OC43 was predominant in the fall and winter, whereas HCoV-HKU1 showed peak activity in winter, with a few cases occurred in spring and summer. HCoV-229 E mainly occurred in winter and spring, while HCoV-NL63 was predominant in summer and autumn. HCoVs most commonly infect the elderly and young children, with median age of 79.5 years(range, 22 days to 95 years).Intriguingly, the detection rate of HCoV-OC43 in the age group of > 80 years(26/2380, 1.09%) was significantly higher than that in the age group of 0–10 years(12/2529, 0.47%)(P 〈 0.05). These data provides new insight into the epidemiology of coronaviruses.
基金supported by the NSFC/RGC Joint Research Project (Nos.42161160329 and N_HKUST609/21)the Research Grants Council of Hong Kong (Nos.GRF 16202120 and T24/504/17)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province (No.2019B121205004)。
文摘Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) concentration.Given the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollution controls can be ambiguous when the assessments focus on the changes in pollutant concentrations.In this study,a risk-based method was used to gauge the net effect of air pollution controls on mortality risk in the Beijing–Tianjin–Hebei(BTH)region during the 2022 Winter Olympics and Paralympics(WOP).This mega-event presents a unique opportunity to investigate the efficacy of deep cuts in pollutant emissions.Results show that O_(3) concentrations greatly increased as nitrogen dioxide(NO_(2))concentrations decreased in the BTH.Due to the active photochemical formations,O_(3) became the dominant pollutant that affected human health during the WOP.Despite the substantial O_(3) increases,the health benefits of NO_(2) reductions overwhelmed the adverse health effects of O_(3) increases in most regions of the BTH(at 81 out of 112 stations).After considering the impacts of particulate matter,the integrated health risk of air pollution mixtures declined almost everywhere in the BTH.Our results underscore the great necessity of changing the assessment paradigm of pollution control from using concentration-based methods to using risk-based methods.Together with the carbon neutrality policy,stringent control of NO_(x)emission from combustion sources is a promising way to achieve synergistic control solutions for air pollution and climate change.
文摘Partial discharges(PDs) due to artificial void in samples of LDPE nanocomposite sheet have been investigated in this work.PDs may cause the degradation of insulating materials and may affect the lifetime of high-voltage apparatus. An experimental work using sphere ball-plane electrode system(CIGRE MethodⅡ) and a 1.0 mm LDPE composite sheet was carried out.Different weight percentages of nanosilica(0%,2%,4%,6%and 8%) were used. PD experimental results,such as PD magnitude and PD number(both PD pulse polarities),as functions of the applied stress duration at a specified applied voltage were compared.The surface morphology of specimens was also presented and this conforms to the PD findings.The experimental results show that the PD characteristics of the LDPE generally improve with the introduction of nanosilica,the composite with the highest content of filler,namely the 8%(wt) nanosilica sample has the least partial discharge activities.
基金This work was partly supported by the Research Fund for the Control of Infectious Diseases(Commissioned study)of the Health,Welfare and Food Bureau of the Hong Kong SAR Government,Research Grant Council GrantUniversity Development Fund.
文摘Two-dimensional gel electrophoresis(2-DE)is a gel-based technique widely used for analyzing the pro-tein composition of biological samples.It is capable of resolving complex mixtures containing more than a thousand protein components into individual protein spots through the coupling of two orthogonal bio-physical separation techniques:isoelectric focusing(first dimension)and polyacrylamide gel electrophore-sis(second dimension).2-DE is ideally suited for ana-lyzing the entire expressed protein complement of a bacterial cell:its proteome.Its relative simplicity and good reproducibility have led to 2-DE being widely used for exploring proteomics within a wide range of envi-ronmental and medically-relevant bacteria.Here we give a broad overview of the basic principles and his-torical development of gel-based proteomics,and how this powerful approach can be applied for studying bacterial biology and physiology.We highlight specific 2-DE applications that can be used to analyze when,where and how much proteins are expressed.The links between proteomics,genomics and mass spectrometry are discussed.We explore how proteomics involving tandem mass spectrometry can be used to analyze(post-translational)protein modifications or to identify proteins of unknown origin by de novo peptide se-quencing.The use of proteome fractionation tech-niques and non-gel-based proteomic approaches are also discussed.We highlight how the analysis of pro-teins secreted by bacterial cells(secretomes or exo-proteomes)can be used to study infection processes or the immune response.This review is aimed at non-specialists who wish to gain a concise,compre-hensive and contemporary overview of the nature and applications of bacterial proteomics.
基金This work was partly supported by funding from the seed fund of The University of Hong Kong-Shenzhen Hospital(HKUSZH201901036).
文摘Although various opportunistic infections have been described in patients with anti-interferon gamma autoantibodies,so far there is no Listeria monocytogenes infection reported to be associated with this primary immunodeficiency.Here,we describe the first case of bacteremic L.monocytogenes meningitis in a 59-year-old Chinese man with anti-interferon gamma autoantibodies,who presented with acute onset of fever and severe headache.Blood culture was positive but culture of the cerebrospinal fluid was negative,although it showed features suggestive of partially treated bacterial meningitis.The presence of L.monocytogenes in the cerebrospinal fluid was confirmed by next-generation sequencing.Avoidance of high-risk food items in these patients is important for the prevention of listeriosis.The use of antibiotic regimens that cover Listeria is crucial for empirical treatment,particularly if such patients develop acute or subacute meningitis.Next-generation sequencing is becoming an important diagnostic modality for culture-negative infections.
基金This work was supported by Innovation and Technology Fund under Grant GHP/016/18GD and Guangdong Special Fund for Science and Technology Development under Grant 2019A050503001.
文摘In this paper,we develop an orthogonal frequency-division multiplexing(OFDM)-based over-theair(OTA)aggregation solution for wireless federated learning(FL).In particular,the local gradients in massive Internet of things(IoT)devices are modulated by an analog waveform and are then transmitted using the same wireless resources.To this end,achieving perfect waveform superposition is the key challenge,which is difficult due to the existence of frame timing offset(TO)and carrier frequency offset(CFO).In order to address these issues,we propose a two-stage waveform pre-equalization technique with a customized multiple access protocol that can estimate and then mitigate the TO and CFO for the OTA aggregation.Based on the proposed solution,we develop a hardware transceiver and application software to train a real-world FL task,which learns a deep neural network to predict the received signal strength with the global positioning system information.Experiments verify that the proposed OTA aggregation solution can achieve comparable performance to offline learning procedures with high prediction accuracy.
基金supported by funding from the Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases,the Ministry of Education of China.
文摘Introduction Target therapies are widely used for treatment of various kinds of hematological malignancies.Since the cancer cells that are targeted,share the same markers with the non-cancerous cells of the immunological system,these therapies are often associated with infectious diseases that require the particular type of immune response for control.In this article,we report a case of Listeria monocytogenes bacteraemia complicating carfilzomib and daratumumab treatment for multiple myeloma.To the best of our knowledge,this is the first case report of listeriosis as a complication of monoclonal antibodies against CD38 and/or proteosome inhibitor therapy.