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Atmospheric particle-bound polycyclic aromatic compounds over two distinct sites in Pakistan:Characteristics,sources and health risk assessment

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Journal of Environmental Sciences 2022年第2期34卷 1-15页

作者： Linda Maharjan Shichang Kang Lekhendra Tripathee Chaman Gul Huijun Zheng Quanlian Li Pengfei Chen mukesh rai Ewerton Santos State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Chinese Academy of Sciences(CAS)Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100085China Himalayan Environment Research Institute Kathmandu 44600Nepal Reading Academy Nanjing University of Information Science&TechnologyNanjingJiangsu 210044China Departamento de Quimica Universidade Federal de SergipeSao CristovaoSergipe SE 49100-000Brazil

Much attention is drawn to polycyclic aromatic hydrocarbons(PAHs)as an air pollutant due to their toxic,mutagenic and carcinogenic ***,to understand the levels,seasonality,sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan,total suspended particle(TSP)samples were collected for over one year *** average total PAH concentrations were 31.5±24.4 and 199±229 ng/m^(3) in Karachi and Mardan,*** significantly lower concentration in Karachi was attributed to diffusion and dilution of the PAHs by the influence of clean air mass from the Arabian sea and high temperature,enhancing the volatilization of the particle phase PAHs to the gas ***,the higher concentration(^(-)6 times)in Mardan was due to large influence from local and regional emission sources.A clear seasonality was observed at both the sites,with the higher values in winter and post-monsoon due to higher emissions and less scavenging,and lower values during monsoon season due to the dilution *** ratios and principal component analysis indicated that PAHs in both sites originated from traffic and mixed combustion sources(fossil fuels and biomass).The average total Ba P equivalent concentrations(Ba P eq)in Karachi and Mardan were 3.26 and 34 ng/m^(3),respectively,which were much higher than the WHO guideline of 1 ng/m^(3).The average estimates of incremental lifetime cancer risk from exposure to airborne Ba P eq via inhalation indicated a risk to human health from atmospheric PAHs at both sites.

关键词： Total suspended particle Polycyclic aromatic hydrocarbons Sources Human health risk

Carbonaceous aerosol transport from the Indo-Gangetic Plain to the Himalayas:Carbon isotope evidence and light absorption characteristics

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Geoscience Frontiers 2023年第2期14卷 105-115页

作者： Pengfei Chen Shichang Kang Chaoliu Li Zhaofu Hu Lekhendra Tripathee mukesh rai Tao Pu Xiufeng Yin Örjan Gustafsson State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)Lanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Department of Environmental Science The Bolin Centre for Climate ResearchStockholm UniversityStockholm 10691Sweden The Bolin Centre for Climate Research Stockholm UniversityStockholm 10691Sweden

The Indo-Gangetic Plain(IGP)is a major regional and global emitter of atmospheric pollutants,which adversely affect surrounding areas such as the *** present a comprehensive dataset on carbonaceous aerosol(CA)composition,radiocarbon(D14C)-based source apportionment,and light absorption of total suspended particle(TSP)samples collected over a 3-year period from high-altitude Jomsom in the central *** 3-year mean TSP,organic carbon(OC),and elemental carbon(EC)concentrations were 92.0±28.6,9.74±6.31,and 2.02±1.35 lg m^(3),respectively,with the highest concentrations observed during the pre-monsoon season,followed by the post-monsoon,winter,and monsoon *** △^(14)C analysis revealed that the contribution of fossil fuel combustion(ffossil)to EC was 47.9%±11.5%,which is consistent with observations in urban and remote regions in South Asia and attests that EC likely arrives in Jomsom from upwind IGP sources via long-range *** addition,the lowest f_(fossil)(38.7%±13.3%)was observed in winter,indicating large contributions in this season from local biomass *** mass absorption cross-section of EC(MACEC:8.27±1.76 m^(2)/g)and watersoluble organic carbon(MACWSOC:0.98±0.45 m^(2)/g)were slightly higher and lower than those reported in urban regions,respectively,indicating that CA undergo an aging *** aerosol coating during transport and variation of biomass burning probably led to the seasonal variation in MAC of two ***,WSOC contributed considerably to the light absorption(11.1%±4.23%)of *** findings suggest that to protect glaciers of the Himalayas from pollution-related melting,it is essential to mitigate emissions from the IGP.

关键词： Carbonaceous aerosol Long-range transport Carbon isotope Source apportionment Light absorption The Himalayas

Modifications in aerosol physical, optical and radiative properties during heavy aerosol events over Dushanbe, Central Asia

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Geoscience Frontiers 2021年第6期12卷 299-312页

作者： Dipesh Rupakheti Maheswar Rupakheti Xiufeng Yin Julian Hofer mukesh rai Yuling Hu Sabur F.Abdullaev Shichang Kang State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Institute for Advanced Sustainability Studies PotsdamGermany Leibniz Institute for Tropospheric Research LeipzigGermany Physical Technical Institute of the Academy of Sciences of Tajikistan DushanbeTajikistan Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China

The location of Central Asia,almost at the center of the global dust belt region,makes it susceptible for dust *** studies on atmospheric impact of dust over the region are very limited despite the large area occupied by the region and its proximity to the mountain regions (Tianshan,Hindu Kush-KarakoramHimalayas,and Tibetan Plateau).In this study,we analyse and explain the modification in aerosols’physical,optical and radiative properties during various levels of aerosol loading observed over Central Asia utilizing the data collected during 2010–2018 at the AERONET station in Dushanbe,*** episodes were classified as strong anthropogenic,strong dust and extreme *** mean aerosol optical depth (AOD) during these three types of events was observed a factor of ~3,3.5 and 6.6,respectively,higher than the mean AOD for the period 2010–*** corresponding mean fine-mode fraction was 0.94,0.20 and 0.16,respectively,clearly indicating the dominance of fine-mode anthropogenic aerosol during the first type of events,whereas coarse-mode dust aerosol dominated during the other two types of *** was corroborated by the relationships among various aerosol parameters (AOD ***,and EAE ***,SSA and RRI).The mean aerosol radiative forcing (ARF) at the top of the atmosphere (ARF_(TOA)),the bottom of the atmosphere (ARF_(BOA)),and in the atmosphere (ARFATM) were -35±7,-73±16,and38±17 Wm^(-2)during strong anthropogenic events,-48±12,-85±24,and 37±15 Wm^(-2)during strong dust event,and -68±19,-117±38,and 49±21 Wm-2during extreme dust *** in aerosol loading enhanced the aerosol-induced atmospheric heating rate to 0.5–1.6 K day^(-1)(strong anthropogenic events),0.4–1.9 K day^(-1)(strong dust events) and 0.8–2.7 K day^(-1)(extreme dust events).The source regions of air masses to Dushanbe during the onset of such events are also *** study contributes to the understanding of dust and anthropogenic aerosols,in particular the extreme

关键词： Dust events Aerosol optical properties AERONET Dushanbe Central Asia

Characteristics of Emission Non-nulling Pulsars Through Simulation

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Research in Astronomy and Astrophysics 2024年第4期24卷 91-102页

作者： rai Yuen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China SIfA School of PhysicsUniversity of SydneySydneyNSW2006Australia

We investigate the population and several properties of radio pulsars whose emission does not null(non-nulling)through simulation of a large pulsar *** from a pulsar is identified as non-nulling if(i)the emission does not cease across the whole pulse profile,and(ii)the emission is ***(i),we adopt a model for switching in the plasma charge density,and emission persists if the charge density is ***(ii),we assume that detectable emission originates from source points where it is emitted tangentially to the magnetic field-line and parallel to the *** find that pulsars exhibiting non-nulling emission possess obliquity angles with an average of 42°.5,and almost half the samples maintain a duty cycle between 0.05 and ***,the pulsar population is not fixed but dependent on the obliquity angle,with the population peaking at 20°.In addition,three evolutionary phases are identified in the pulsar population as the obliquity angle evolves,with the majority of samples having an obliquity angle between 20°and 65°.Our results also suggest that emission from a pulsar may evolve between nulling and non-nulling during its lifetime.

关键词： radiation mechanisms:non thermal stars:neutron (stars:)pulsars:general

Analysis and Optimization of Operational and Pollutant Attributes of Diesel Engine with CNT-Infused Orange Peel Biodiesel-Diesel Blend Fuel

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Journal of Thermal Science 2024年第2期33卷 761-778页

作者： Ranjeet rai R.R.SAHOO Mechanical Engineering Department GLA UniversityMathura281406India Mechanical Engineering Department IIT(BHU)Varanasi221005India

The current study is performed to find sustainable solutions for the future of transportation and environmental *** conventional methods and experimental design table(L16 Orthogonal Array)techniques have been employed to examine and optimize a diesel-powered engine's operational and pollutant *** L16 Orthogonal Array is obtained through Taguchi's experimental design approach using Minitab 16 *** experimental design incorporated three control variables,namely engine speed,fuel type,and engine load,each with four *** operational parameters,namely brake thermal efficiency(BTE)and brake specific fuel consumption(BSFC),as well as the emission characteristics,including hydrocarbon(HC),carbon monoxide(CO),nitrogen oxide(NO),and smoke emissions,were acquired using the L16 orthogonal array(OA) and subsequently *** utilization of methodologies such as signal-to-noise(S/N) ratio and grey analysis was employed to determine the optimal operational state of the engine to achieve maximum performance while minimizing *** engine's ideal state of operation,in terms of BTE and BSFC,was determined to be at 75% engine load,1000 r/min engine speed,and using 10^(-4)(in vol) carbon nanotube incorporated 20% orange peel biodiesel(OPB20CNT100) blended fuel(A3-B1-C4).The study indicated that engine load significantly influenced BTE and BSFC,with 84.05% and 87.79% contribution factors,*** 25% engine load,1000 r/min,and OPB20CNT100 fuel(A1-B1-C4) CO,smoke,NO,and HC emissions were the *** load affects emissions the *** BSFC increased 3.10% and NO emissions 1.77%.BTE,CO,smoke,and HC emissions decreased by 1.9%,12.29%,47.05%,and 47.22%,respectively,at optimal operating conditions concerning diesel *** study shows that Taguchi-Grey's experimental design optimizes diesel engine operational and pollutant *** outcomes revealed that orange peel biodiesel infused with CNT can replace diesel fuel in a

关键词： Taguchi-Grey method OPB20CNT100 transesterification S/N ratio GRG HC CO and NO

Phytochemical analysis of Tinospora cordifolia and Withania somnifera and their therapeutic activities with special reference to COVID-19

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World Journal of Experimental Medicine 2024年第3期14卷 39-47页

作者： Prateek rai Tanya Garain Deepshikha Gupta Chemistry Amity Institute of Applied SciencesAmity UniversityNoida 201301Uttar PradeshIndia

Various important medicines make use of secondary metabolites that are produced by *** plants,such as Withania somnifera and Tinospora cordifolia,are rich sources of chemically active compounds and are reported to have numerous therapeutic *** therapeutic use of medicinal plants is widely mentioned in Ayurveda and has folkloric importance in different parts of the *** aim of this review is to summarize the phytochemical profiles,folkloric importance,and primary pharmacological activity of *** and *** with emphasis on their action against the novel coronavirus.

关键词： Phytochemical analysis Tinospora cordifolia Withania somnifera COVID-19 Immunomodulators Giloy Ashwagandha

Establishing the relationship between land use land cover,normalized difference vegetation index and land surface temperature:A case of Lower Son River Basin,India

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Geography and Sustainability 2024年第2期5卷 265-275页

作者： Shipra Singh Pankaj Kumar Rakhi Parijat Barbaros Gonengcil Abhinav rai Department of Geography Miranda HouseUniversity of DelhiDelhiIndia Department of Geography Delhi School of EconomicsUniversity of DelhiDelhiIndia Department of Geography Istanbul UniversityIstanbulTurkey

The study explores the intricate interplay between land use land cover(LULC),normalized difference vegetation index(NDVI),and land surface temperature(LST)within the Lower Son River Basin in India from 1991 to *** region’s ecological balance has been increasingly strained due to rapid urbanization and changing land use *** a combination of Landsat TM&OLI/TIRS satellite imageries and geospatial analysis techniques,this study unveils the intricate connection between land use and land cover changes,vegetation,and land surface temperature *** study area is classified into three altitudinal zones(Zone Ⅰ:39–300 m,Zone Ⅱ:301–600 m and Zone Ⅲ:601–1,247 m)to examine the changes in *** area has seen significant changes in LULC,vegetation and LST in all the three altitudinal *** findings hold significant implications for sustainable land management and environmental conservation strategies in the Lower Son River *** per the result,103,438 ha of vegetation was converted into agriculture land and 82,572 ha of agricultural land was transformed into settlements from 1991 to *** trend shows human pressure on the land resource in the study *** increase in water body is seen which is attributed to commissioning of Bansagar *** Ⅰ has seen highest settlement growth while Zone Ⅲ experienced severe deforestation of around 15%.Zone Ⅱ and Ⅲ needs attention for holistic *** of LST shows that it has increased by 0.82℃ from 1991 to 2020 which is a red *** study underscores the critical importance of balanced land use practices to preserve ecological integrity and mitigate the adverse effects of urbanization and climate change.

关键词： Lower Son River Basin LULC LST NDVI Correlation

Resmetirom: Breakthrough therapeutic approach for metabolic dysfunction-associated steatohepatitis

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Liver Research 2024年第3期8卷 193-194页

作者： Anzel Saeed Kuldeep Dalpat rai Department of Medicine Dow Medical CollegeDow University of Health SciencesKarachiPakistan

To the editor,Metabolic dysfunction-associated steatohepatitis(MASH)is the active and progressive stage of metabolic dysfunction-associated steatotic liver disease,characterized by the presence of lipid accumulation in hepatocytes with inflammation and hepatocyte injury(e.g.,ballooning),with or without fibrosis.1 Patients with advanced MASH fibrosis experience increased morbidity and mortality due to progression of liver disease,including progression to cirrhosis,liver failure,and hepatocellular carcinoma.2,3 Currently,there is no approved therapy for MASH,and its prevalence has increased with the increasing global prevalence of obesity.4,5 Similar to other metabolic diseases,lifestyle modifications are effective for managing MASH but are difficult to implement and maintain.

关键词： balloon prevalence mortality

Multiplexed fluorescence and scatter detection with single cell resolution using on-chip fiber optics for droplet microfluidic applications

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Microsystems & Nanoengineering 2024年第2期10卷 207-218页

作者： Preksha Gupta Ambili Mohan Apurv Mishra Atindra Nair Neeladri Chowdhury Dhanush Balekai Kavyashree rai Anil Prabhakar Taslimarif Saiyed Discovery Innovation Accelerator Centre for Cellular and Molecular PlatformsBellary RoadBengaluru560065KarnatakaIndia Department of Electrical Engineering Indian Institute of Technology MadrasChennai600036Tamil NaduIndia

Droplet microfluidics has emerged as a critical component of several high-throughput single-cell analysis techniques in biomedical research and *** significant progress in the development of individual assays,multiparametric optical sensing of droplets and their encapsulated contents has been *** current approaches,most commonly involving microscopy-based high-speed imaging of droplets,are technically complex and require expensive instrumentation,limiting their widespread *** address these limitations,we developed the OptiDrop platform;this platform is a novel optofluidic setup that leverages the principles of flow *** platform enables on-chip detection of the scatter and multiple fluorescence signals from the microfluidic droplets and their contents using optical *** highly customizable on-chip optical fiber-based signal detection system enables simplified,miniaturized,low-cost,multiparametric sensing of optical signals with high sensitivity and single-cell resolution within each *** demonstrate the ability of the OptiDrop platform,we conducted a differential expression analysis of the major histocompatibility complex(MHC)protein in response to IFNγ*** results showed the platform’s ability to sensitively detect cell surface biomarkers using fluorescently labeled ***,the OptiDrop platform combines the versatility of flow cytometry with the power of droplet microfluidics to provide wide-ranging,scalable optical sensing solutions for research and diagnostics.

关键词： scatter enable resolution