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First application of plutonium in soil erosion research on terraces

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Nuclear Science and Techniques 2023年第4期34卷 41-53页

作者： Yong-Jing Guan Wu Chen Shen-Zhen Wang Yu-Xin Hua Qiao-Yan Jing Zhi-Yong Liu Chun-Ping Huang De-Yu Wang Hui-Juan Wang Xian-Wen He Mario De Cesare Liang-Jia Cui Hua He Kai-Di Fan Zi-Chen Guo Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Centre of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou 215123China Radiation-Environment Management and Monitoring Station of Guangxi Zhuang Autonomous Region Nanning 530222China Department of Large Ground Testing Facilities CIRA-Italian Aerospace Research Centre81043 CapuaItaly Department of Mathematics and Physics University of Campania“Luigi Vanvitelli”81100 CasertaItaly INFN-National Institute for Nuclear Physics Naples Section80126 NaplesItaly

The spatial distributions of ^(239+240)Pu and ^(137)Cs in soils from Longji Rice Terraces were investigated to evaluate soil erosion.The activity concentrations of ^(239+240)Pu and ^(137)Cs in the surface soils of the paddy fields were in the range of 0.089–0.734 and1.80–7.88 mBq/g,respectively.The activities of ^(239+240)Pu and ^(137)Cs showed very similar distribution trends,first increasing and then decreasing with increasing elevation.The 240Pu/239Pu atom ratios in the surface soils ranged from 0.162 to 0.232.The activities of ^(239+240)Pu and ^(137)Cs in the soil cores tended to be uniformly distributed within the plowed layer and declined exponentially below this depth.The mean soil erosion rates of Longji Rice Terraces estimated by ^(239+240)Pu and ^(137)Cs tracer methods were 5.44 t/(ha·a)and 5.16 t/(ha·a),respectively,which demonstrated that plutonium can replace ^(137)Cs as an ideal tracer for soil erosion research in the future.Landform features are the main factors affecting the distribution of plutonium and ^(137)Cs as well as soil erosion in the Longji Rice Terraces.

关键词： Soil erosion Plutonium ^(137)Cs Tracer method Terraces

A comparison between Smoothed-Particle Hydrodynamics and RANS Volume of Fluid method in modelling slamming

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Journal of Ocean Engineering and Science 2016年第2期1卷 119-128页

作者： Marcus Sasson Shuhong Chai Genevieve Beck Yuting Jin Jalal Rafieshahraki National centre for Maritime Engineering and Hydrodynamics Australian Maritime CollegeUniversity of TasmaniaLauncestonTasmaniaAustralia

The oil and gas industry requires complex subsea infrastructure in order to develop offshore oil and gas fields.Upon installation,these components may encounter high slamming loads,stemming from impact with the water surface.This paper utilises two different numerical methods,the mesh-free Smoothed Particle Hydrodynamics(SPH)approach and Reynolds Averaged Navier-Stokes(RANS)Volume of Fluid(VOF)method to quantify these loads on a free-falling object.The investigation is also interested in conducting a parameter study and determining the effect of varying simulation parameters on the prediction of slamming event kinematics and forces.The surface impact of a freefalling wedge was introduced as a case study and has been simulated using SPH and RANS,with the results being compared to an experimental investigation.It was found from the SPH simulations that particle resolution and the size of the SPH particle kernel are very important,whilst the diffusion term does not play an important role.The latter is due to the very transient nature of slamming events,which do not allow sufficient time for diffusion in the fluid domain.For the RANS simulations,motion of the wedge was achieved using the overset grid technique,whereby varying the discretising time step was found to have a pronounced impact on the accuracy of the captured slamming event.Through analysing the numerical data,one can observe that the RANS results correlate slightly better with the experimental data as opposed to that obtained from the SPH modelling.However,considering the robustness and quick set up of the SPH simulations,both of these two numerical approaches are considered to be promising tools for modelling more complicated slamming problems,including those potentially involving more intricate structures.

关键词： Smoothed Particle Hydrodynamics Reynolds Averaged Navier-Stokes Slamming load Wedge

Critical Care(重症照顾):概念分析

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International Journal of Nursing Sciences 2023年第3期10卷 403-413页

作者： Martin Christensen Mining Liang School of Nursing The Hong Kong Polytechnic UniversityHong KongChina The Interdisciplinary centre for Qualitative Research The Hong Kong Polytechnic UniversityHong KongChina

目的"Critical Care"(重症照顾)和"Intensive Care Unit"(重症监护室)这两个术语在实际工作中描述一个医疗场所时经常被互换使用。对"Critical Care"的口语化使用使得其准确定义具有挑战性。本文旨在对"Critical Care"进行概念分析,制... 详细信息

目的"Critical Care"(重症照顾)和"Intensive Care Unit"(重症监护室)这两个术语在实际工作中描述一个医疗场所时经常被互换使用。对"Critical Care"的口语化使用使得其准确定义具有挑战性。本文旨在对"Critical Care"进行概念分析,制定其操作性定义(operational definition),明确其内涵。方法采用Walker和Avant八步法来指导本研究。检索数据库(CINAHL、Scopus、PubMed、ProQuest Dissertation Abstracts和Med line in EBSCO)中"Critical Care"相关文献,包括1990--2022年以英文撰写发表的质性和量性研究论文。结果.共检索到439篇论文,其中47篇符合纳人标准。"Critical Care"的概念属性包括:1)对疾病/损伤的不适应;2)收治标准;3)高精医疗技术;4)专业的医疗护理人员。前因是疾病/损伤进展到危急状况,患者身体和心理功能都明显下降,后续影响是死亡或存活(有或没有ICU治疗后综合症)。结论重症监护环境的高技术含量特性使关于“Critical Care"的描述更具挑战性。对此术语进行概念分析有助于明确其内涵和范围,为未来研究提供参考,促进相关评估工具的开发,深入了解重症监护环境中的医疗护理工作本质。

关键词：重症照顾概念分析重症监护重症监护病房重症治疗

Environmental chemical stressors as epigenome modifiers:a new horizon in assessment of toxicological effects

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Chinese Science Bulletin 2014年第4期59卷 349-355页

作者： Heqing Shen F.L.Martin Yanhua Su Key Laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences centre for Biophotonics Lancaster Environment CentreLancaster University Department of Preventive Medicine School of Public Health of Xiamen University

In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ‘‘accessibility hypothesis' '. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference(RNAi) and other func- tional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic- modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations.

关键词：环境化学基因修饰压力源表观毒理效应评估 DNA甲基化相互作用

Three-dimensional reconstructed magnetic resonance scans:Accuracy in identifying and defining knee meniscal tears

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World Journal of Orthopedics 2016年第11期7卷 731-737页

作者： Neil Kruger Eugene Mc Nally Sami Al-Ali Raj Rout Jonathan L Rees Andrew J Price Orthopaedic Research Unit University of Cape Town Nuffield Orthopaedic centre University of Oxford the Whittington Hospital

AIM To determine whether three-dimensional(3D) reconstruction from conventional magnetic resonance imaging(MRI) is able to accurately detect a meniscal tear, and define the configuration.METHODS Thirty-three patients' 3T MRI scan data were collected and sagittal uni-planar 3D reconstructions performed from the preoperative MRI. There were 24 meniscal tears in 24 patients, and nine controls. All patients had arthroscopic corroboration of MRI findings. Two independent observers prospectively reported on all 33 reconstructions. Meniscal tear presence or absence was noted, and tear configuration subsequently categorised as either radial, bucket-handle, parrot beak, horizontal or complex.RESULTS Identification of control menisci or meniscal tear presence was excellent(Accuracy: observer 1 = 90.9%; observer 2 = 81.8%). Of the tear configurations, bucket handle tears were accurately identified(Accuracy observer 1 and 2 = 80%). The remaining tear configurations were notaccurately discernable.CONCLUSION Uni-planar 3D reconstruction from 3T MRI knee scan sequences are useful in identifying normal menisci and menisci with bucket-handle tears. Advances in MRI sequencing and reconstruction software are awaited for accurate identification of the remaining meniscal tear configurations.

关键词： Knee Meniscus Arthroscopy Magnetic resonance imaging Three-dimensional reconstruction Materialise Interactive Medical Control System Tear

Size-transformable nanoparticles with sequentially triggered drug release and enhanced penetration for anticancer therapy

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Nano Research 2023年第8期16卷 11186-11196页

作者： Yulin Li Liudi Wang Guoqiang Zhong Guoying Wang Yanzhao Zhu Jian Li Lan Xiao Yanhui Chu Yan Wu Kaichun Li Jie Gao Engineering Research centre for Biomedical Materials of Ministry of Education The Key Laboratory for Ultrafine Materials of Ministry of EducationFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Material Science and EngineeringEast China University of Science and TechnologyShanghai 200237China Department of Oncology Shanghai Fourth People’s Hospital School of MedicineTongji UniversityShanghai 200434China Changhai Clinical Research Unit Shanghai Changhai HospitalNaval Medical UniversityShanghai 200433China College of Life Sciences Mudanjiang Medical University Mudanjiang 157011China Wenzhou Institute of Shanghai University Wenzhou 325000China centre for Biomedical Technologies Queensland University of TechnologyBrisbaneQLD 4059Australia

There are several limitations to the application of nanoparticles in the treatment of cancer,including their low drug loading,poor colloidal stability,insufficient tumor penetration,and uncontrolled release of the drug.Herein,gelatin/laponite(LP)/doxorubicin(GLD)nanoparticles are developed by crosslinking LP with gelatin for doxorubicin delivery.GLD shows high doxorubicin encapsulation efficacy(99%)and strong colloidal stability,as seen from the unchanged size over the past 21 days and reduced protein absorption by 48-fold compared with unmodified laponite/doxorubicin nanoparticles.When gelatin from 115 nm GLD reaches the tumor site,matrix metallopeptidase-2(MMP-2)from the tumor environment breaks it down to release smaller 40 nm LP nanoparticles for effective tumor cell endocytosis.As demonstrated by superior penetration in both in vitro three-dimensional(3D)tumor spheroids(138-fold increase compared to the free drug)and in vivo tumor models.The intracellular low pH and MMP-2 further cause doxorubicin release after endocytosis by tumor cells,leading to a higher inhibitory potential against cancer cells.The improved anticancer effectiveness and strong in vivo biocompatibility of GLD have been confirmed using a mouse tumor-bearing model.MMP-2/pH sequentially triggered anticancer drug delivery is made possible by the logical design of tumor-penetrating GLD,offering a useful method for anticancer therapy.

关键词： sequentially triggered drug release size-transformable nanoparticles tumor penetration anticancer therapy drug delivery

Advances in the chemical leaching (inorgano-leaching), bioleaching and desulphurisation of coals

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International Journal of Coal Science & Technology 2019年第2期6卷 169-183页

作者： Heena Dhawan Durlubh Kumar Sharma centre for Energy Studies Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India

Coal still remains an important source of power generation world over. Along with its usage, comes unwanted generation of noxious gas emissions, toxic metal releases into wastewater and other pollutants which ultimately lead to environmental concerns. So cleaning of coal through physical or chemical processes becomes utmost important. There are several coals which cannot be cleaned by physical beneficiation techniques to produce low ash cleaner coals. Such coals can be cleaned only through chemical cleaning techniques. The present paper reviews the chemical demineralisation and desulphurisation of coals over the years using various inorganic and organic acids, alkalis, oxidants, leachants and various acids and alkali-acid combinations to reduce the ash and sulphur contents in coals. As high as 90% demineralisation and desulfurization could be achieved with the use of these cheap inorganic acids as compared to the expensive solvents used for solvent extraction processes, a parallel approach of cleaning and refining coals.

关键词： Coal Demineralisation Desulfurization Acids Alkalis

Evidence of the oldest extant vascular plant(horsetails)from the Indian Cenozoic

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植物多样性:英文版 2023年第5期45卷 569-589页

作者： Sampa Kundu Taposhi Hazra Tapan Chakraborty Subir Bera Mahasin Ali Khan Palaeobotany and Palynology Laboratory Department of BotanySidho-Kanho-Birsha UniversityRanchi RoadPurulia 723104India Geological Studies Unit Indian Statistical Institute203B.T.RoadKolkata 700108West BengalIndia centre of Advanced Study Department of BotanyUniversity of Calcutta35B.C.RoadKolkata 700019India

Equisetum(Equisetaceae)has long been a focus of attention for botanists and palaeontologists because,given its extensive and well-documented fossil record,it is considered the oldest extant vascular plant and a key element in understanding vascular plant evolution.However,to date,no authentic fossil evidence of Equisetum has been found from the Indian Cenozoic.Here,we describe a new fossil species,namely,E.siwalikum sp.nov.,recovered from the middle Siwalik(Late Miocene)sediments of Himachal Pradesh,western Himalaya.We identified fossil specimens based on morphological and epidermal characters.In addition,X-Ray diffraction(XRD)analysis was used to determine the mineral composition of compressed stems of Equisetum.The close affinity of our recovered Siwalik fossils to Equisetum is supported by the presence of both macromorphological and epidermal characters.Because Equisetum generally grows in wet conditions around water reservoirs,our findings indicate that the fossil locality was humid and surrounded by swamp and lowland regions during deposition.Ample fossil evidence indicates that this sphenopsid once existed in the western Himalaya during the Siwalik period.However,at present Equisetum is confined to a particular area of our fossil locality,probably a consequence of severe environmental changes coupled with competition from opportunistic angiosperms.Our discovery of Equisetum fossils in appreciable numbers from the Siwalik sediments of the Himachal Himalayas is unique and constitutes the first reliable recognition of Equisetum from the Indian Cenozoic.

关键词： Equisetum Fossil stem and leaf sheaths Late Miocene Paleoecology Siwalik Western India

Prediction of salinity intrusion in the sheltered estuary of Terengganu River in Malaysia using 1-D empirical intrusion model

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Acta Oceanologica Sinica 2017年第5期36卷 57-66页

作者： LEE Hin Lee TANGANG Fredolin GISEN Jacqueline Isabella SURATMAN Saim Research centre for Tropical Climate Change Faculty of Science and TechnologyThe National University of MalaysiaUKM Bangi 43600Malaysia Research centre for Water Quality and Environment National Hydraulic Research Institute of MalaysiaMinistry of Natural Resources and EnvironmentSeri Kembangan 43300Malaysia centre for Earth Resources Research and Management Faculty of Civil Engineering and Earth ResourcesThe Universiti Malaysia PahangPahang 26600Malaysia

Generally one dimensional （l-D） empirical salinity intrusion model is limited to natural alluvial estuary. However, this study attempts to investigate its ability to model a sheltered alluvial estuary of the Terengganu River in Malaysia. The constructed breakwater at the mouth of the river shelters the estuary from direct influence of the open sea. The salinity density along the estuary was collected during the wet and dry seasons for scenarios before and after the constructed breakwater. Moreover, the freshwater discharges, tidal elevations and bathymetry data were also measured as model inputs. A good fit was demonstrated between simulated and observed variables, namely salinity distribution and intrusion length for both scenarios. Thus, the results show that 1-D empirical salinity model can be utilized for sheltered estuarine condition at the Terengganu Estuary, but with an appropriate determination of an initial point. Furthermore, it was observed that the salinity intrusion in the study area is largely dependent on the freshwater discharge rather than tidal elevation fluctuations. The scale of the salinity intrusion length in the study area is proportional to the river discharge of the -1/2 power. It was appeared that the two lines of the 1-D empirical salinity model and discharge power based equation fitted well to each other, with the average predicted minimum freshwater discharge of 150 m^3/s is going to be required to maintain acceptable salinity levels during high water slack （HWS） near the water intake station, which is located at 10.63 km from river mouth.

关键词： salinity intrusion sheltered estuary freshwater discharge geometric characteristic empirical model