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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 properties.Therefore,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 period.The average total PAH concentrations were 31.5±24.4 and 199±229 ng/m^(3) in Karachi and Mardan,respectively.The 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 phase.Conversely,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 effect.Diagnostic 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 Himalayas.We 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 Himalayas.The 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 seasons.The △^(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 transport.In addition,the lowest f_(fossil)(38.7%±13.3%)was observed in winter,indicating large contributions in this season from local biomass burning.The 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 process.Organic aerosol coating during transport and variation of biomass burning probably led to the seasonal variation in MAC of two components.Overall,WSOC contributed considerably to the light absorption(11.1%±4.23%)of EC.The 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 events.The 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,Tajikistan.Aerosol episodes were classified as strong anthropogenic,strong dust and extreme dust.The 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 2010–2018.The 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 events.This was corroborated by the relationships among various aerosol parameters (AOD vs.AE,and EAE vs.AAE,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 events.Increase 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 identified.Our study contributes to the understanding of dust and anthropogenic aerosols,in particular the extreme events and their disproportionally high radiativ

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 sample.Emission 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 detectable.For(i),we adopt a model for switching in the plasma charge density,and emission persists if the charge density is non-zero.For(ii),we assume that detectable emission originates from source points where it is emitted tangentially to the magnetic field-line and parallel to the line-of-sight.We 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 0.2.Furthermore,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 well-being.Both 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 parameters.The L16 Orthogonal Array is obtained through Taguchi's experimental design approach using Minitab 16 software.The experimental design incorporated three control variables,namely engine speed,fuel type,and engine load,each with four levels.The 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 examined.The 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 emissions.The 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,respectively.At 25% engine load,1000 r/min,and OPB20CNT100 fuel(A1-B1-C4) CO,smoke,NO,and HC emissions were the lowest.Engine load affects emissions the most.Engine 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 fuel.This study shows that Taguchi-Grey's experimental design optimizes diesel engine operational and pollutant attributes.The outcomes revealed that orange peel biodiesel infused with CNT can replace diesel fuel in an environmentally friendly way.This alternative

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

Spectrum of COVID-19 induced liver injury:A review report

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World Journal of Hepatology 2024年第4期16卷 517-536页

作者： Lokjan Singh Anil Kumar Maya rai Bibek Basnet Nishant rai Pukar Khanal Kok-Song Lai Wan-Hee Cheng Ahmed Morad Asaad Shamshul Ansari Department of Microbiology Karnali Academy of Health ScienceTeaching HospitalJumla 21200KarnaliNepal Health Sciences Asian College of Advance StudiesPurbanchal UniversitySatdobato 24122LalitpurNepal Department of Biotechnology Graphic Era(Deemed to be University)Dehradun 248002UttarakhandIndia Department of Pharmacology&Toxicology KLE College of PharmacyBelagaviKLE Academy of Higher Education and ResearchBelagavi 590010KarnatakaIndia Division of Health Sciences Abu Dhabi Women's CollegeHigher Colleges of TechnologyAbu Dhabi 41012United Arab Emirates Health and Life Sciences INTI International UniversityNilai 71800Malaysia Department of Microbiology College of MedicineZagazig UniversityZagazig 44519Egypt

The coronavirus disease 2019(COVID-19)pandemic has caused changes in the global health system,causing significant setbacks in healthcare systems worldwide.This pandemic has also shown resilience,flexibility,and creativity in reacting to the tragedy.The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection targets most of the respiratory tract,resulting in a severe sickness called acute respiratory distress syndrome that may be fatal in some individuals.Although the lung is the primary organ targeted by COVID-19 viruses,the clinical aspect of the disease is varied and ranges from asymptomatic to respiratory failure.However,due to an unorganized immune response and several affected mechanisms,the liver may also experience liver cell injury,ischemic liver dysfunction,and drug-induced liver injury,which can result in respiratory failure because of the immune system’s disordered response and other compromised processes that can end in multisystem organ failure.Patients with liver cirrhosis or those who have impaired immune systems may be more likely than other groups to experience worse results from the SARS-CoV-2 infection.We thus intend to examine the pathogenesis,current therapy,and consequences of liver damage concerning COVID-19.

关键词： Autoimmune liver disease COVID-19 Clinical manifestation of liver Drug-induced liver injury SARS-CoV-2

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 diagnostics.Despite significant progress in the development of individual assays,multiparametric optical sensing of droplets and their encapsulated contents has been challenging.The current approaches,most commonly involving microscopy-based high-speed imaging of droplets,are technically complex and require expensive instrumentation,limiting their widespread adoption.To address these limitations,we developed the OptiDrop platform;this platform is a novel optofluidic setup that leverages the principles of flow cytometry.Our platform enables on-chip detection of the scatter and multiple fluorescence signals from the microfluidic droplets and their contents using optical fibers.The 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 droplet.To demonstrate the ability of the OptiDrop platform,we conducted a differential expression analysis of the major histocompatibility complex(MHC)protein in response to IFNγstimulation.Our results showed the platform’s ability to sensitively detect cell surface biomarkers using fluorescently labeled antibodies.Thus,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

GUARDIAN: A Multi-Tiered Defense Architecture for Thwarting Prompt Injection Attacks on LLMs

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Journal of Software Engineering and Applications 2024年第1期17卷 43-68页

作者： Parijat rai Saumil Sood Vijay K. Madisetti Arshdeep Bahga School of Computer Science Engineering & Technology Bennett University Greater Noida India School of Cybersecurity and Privacy Georgia Institute of Technology Atlanta USA Cloudemy Technology Labs Chandigarh India

This paper introduces a novel multi-tiered defense architecture to protect language models from adversarial prompt attacks. We construct adversarial prompts using strategies like role emulation and manipulative assistance to simulate real threats. We introduce a comprehensive, multi-tiered defense framework named GUARDIAN (Guardrails for Upholding Ethics in Language Models) comprising a system prompt filter, pre-processing filter leveraging a toxic classifier and ethical prompt generator, and pre-display filter using the model itself for output screening. Extensive testing on Meta’s Llama-2 model demonstrates the capability to block 100% of attack prompts. The approach also auto-suggests safer prompt alternatives, thereby bolstering language model security. Quantitatively evaluated defense layers and an ethical substitution mechanism represent key innovations to counter sophisticated attacks. The integrated methodology not only fortifies smaller LLMs against emerging cyber threats but also guides the broader application of LLMs in a secure and ethical manner.

关键词： Large Language Models (LLMs) Adversarial Attack Prompt Injection Filter Defense Artificial Intelligence Machine Learning Cybersecurity

The Bright Single Pulse Emission from PSR B1133+16

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Research in Astronomy and Astrophysics 2024年第4期24卷 253-261页

作者： Jun Tan Zhi-Gang Wen Zhen Wang Xue-Feng Duan Hong-Guang Wang Na Wang Vishal Gajjar Jian-Ping Yuan rai Yuen Wen-Ming Yan Jian-Ling Chen Wei Han Hui Wang Cheng-Bing Lyu Ai-Jun Dong Maths and Information Technology School Yuncheng UniversityYuncheng 044000China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China Space Science Laboratory University of CaliforniaBerkeley 94710USA Department of Physics and Electronic Engineering Yuncheng UniversityYuncheng 044000China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550025China

We have conducted a comprehensive investigation into the bright single pulse emission from PSR B1133+16using the Giant Metrewave Radio Telescope.High time resolution data(61μs)were obtained at a center frequency of 322 MHz with a bandwidth of 32 MHz over a continuous observation period of 7.45 hr.A total of 1082 bright pulses were sporadically detected with peak flux densities ranging from 10 to 23 times stronger than the average pulse profile.However,no giant pulse-like emission with a relative pulse energy larger than 10 and extremely short duration was detected,indicating that these bright pulses cannot be categorized as giant pulse emission.The majority of these bright pulses are concentrated in pulse phases at both the leading and trailing windows of the average pulse profile,with an occurrence ratio of approximately 2.74.The pulse energy distribution for all individual pulses can be described by a combination of two Gaussian components and a cutoff power-law with an index of α=-3.2.An updated nulling fraction of 15.35%±0.45% was determined from the energy distribution.The emission of individual pulses follows a log-normal distribution in peak flux density ratio.It is imperative that regular phase drifting in bright pulse sequence is identified in both the leading and trailing components for the first time.Possible physical mechanisms are discussed in detail to provide insights into these observations.

关键词： (stars:)pulsars:general (stars:)pulsars:individual(PSR B1133+16) methods:observational methods:data analysis