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The missing base molecules in atmospheric acid-base nucleation

national Science Review 2022年第10期9卷 196-208页

作者： Runlong Cai Rujing Yin Chao Yan Dongsen Yang Chenjuan Deng Lubna Dada Juha Kangasluoma Jenni Kontkanen Roope Halonen Yan Ma Xiuhui Zhang Pauli Paasonen Tuukka Pet?j? Veli-Matti Kerminen Yongchun Liu Federico Bianchi Jun Zheng Lin Wang Jiming Hao James n.smith neil M. Donahue Markku Kulmala Douglas R.Worsnop Jingkun Jiang State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Institute for Atmospheric and Earth System Research/Physics Faculty of Science University of Helsinki Aerosol and Haze Laboratory Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science and Technology Laboratory of Atmospheric Chemistry Paul Scherrer Institute Center for Joint Quantum Studies and Department of Physics School of Science Tianjin University Key Laboratory of Cluster Science Ministry of Education of China School of Chemistry and Chemical Engineering Beijing Institute of Technology Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3) Department of Environmental Science and Engineering Fudan University Chemistry Department University of California Center for Atmospheric Particle Studies Carnegie Mellon University Department of Chemistry Carnegie Mellon University Aerodyne Research Inc.

Transformation of low-volatility gaseous precursors to new particles affects aerosol number concentration,cloud formation and hence the *** clustering of acid and base molecules is a major mechanism driving fast nucleation and initial growth of new particles in the ***,the acid-base cluster composition,measured using state-of-the-art mass spectrometers,cannot explain the measured high formation rate of new *** we present strong evidence for the existence of base molecules such as amines in the smallest atmospheric sulfuric acid clusters prior to their detection by mass *** demonstrate that forming（H2SO4）1（amine）1is the rate-limiting step in atmospheric H2SO4-amine nucleation and the uptake of（H2SO4）1（amine）1is a major pathway for the initial growth of *** proposed mechanism is very consistent with measured new particle formation in urban Beijing,in which dimethylamine is the key base for H2SO4nucleation while other bases such as ammonia may contribute to the growth of larger *** findings further underline the fact that strong amines,even at low concentrations and when undetected in the smallest clusters,can be crucial to particle formation in the planetary boundary layer.

关键词： new particle formation acid-base nucleation aerosol polluted urban environment

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natural killer cell-triggered vascular transformation:maternal care before birth?

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Cellular & Molecular Immunology 2011年第1期8卷 1-11页

作者： Jianhong Zhang Zhilin Chen Graeme n.smith B.Anne Croy Department of Anatomy and Cell Biology Queen’s UniversityKingstonONCanada Department of Obstetrics and Gynecology Queen’s UniversityKingstonONCanada

natural killer(nK)cells are found in lymphoid and non-lymphoid *** addition to important roles in immune surveillance,some nK cells contribute to angiogenesis and circulatory *** uterus of early pregnancy is a non-lymphoid organ enriched in nK cells that are specifically recruited to placental attachment *** species with invasive hemochorial placentation,these uterine natural killer(unK)cells,via secretion of cytokines,chemokines,mucins,enzymes and angiogenic growth factors,contribute to the physiological change of mesometrial endometrium into the unique stromal environment called decidua *** humans,unK cells have the phenotype CD56^(bright) CD16^(dim) and they appear in great abundance in the late secretory phase of the menstrual cycle and early *** expression studies indicate that CD56^(bright) CD16^(dim) uterine and circulating cells are functionally *** humans but not mice or other species with post-implantation decidualization,unK cells may contribute to blastocyst implantation and are of interest as therapeutic targets in female *** and genetic studies in mice first identified triggering of the process of gestation spiral arterial modification as a major unK cell function,achieved via interferon(IFn)-c *** spiral arterial modification,branches from the uterine artery that traverse the endometrium/decidua transiently lose their muscular coat and ability to *** expression of vascular markers changes from arterial to venous as these vessels dilate and become low-resistance,high-volume *** understanding of the vascular interactions of human unK cells is difficult to obtain because endometrial time-course studies are not possible in pregnant *** we briefly review key information concerning unK cell functions from studies in rodents,summarize highlights concerning human unK cells and describe our preliminary studies on development of a humanized,pregnant

关键词： decidua humanized mice pregnancy uterine natural killer cell

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Balanced and Unbalanced Components of Moist Atmospheric Flows with Phase Changes

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Chinese Annals of Mathematics,Series B 2019年第6期40卷 1005-1038页

作者： Alfredo n.WETZEL Leslie M.smith Samuel n.STECHMAnn Jonathan E.MARTIn Department of Mathematics University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics and Department of Engineering Physics University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics and Department of Atmospheric and Oceanic Sciences University of Wisconsin-MadisonMadisonWI 53706USA Department of Atmospheric and Oceanic Sciences University of Wisconsin-MadisonMadisonWI 53706USA

Atmospheric variables(temperature, velocity, etc.) are often decomposed into balanced and unbalanced components that represent low-frequency and high-frequency waves, respectively. Such decompositions can be defined, for instance, in terms of eigenmodes of a linear operator. Traditionally these decompositions ignore phase changes of water since phase changes create a piecewise-linear operator that differs in different phases(cloudy versus non-cloudy). Here we investigate the following question: How can a balanced–unbalanced decomposition be performed in the presence of phase changes? A method is described here motivated by the case of small Froude and Rossby numbers,in which case the asymptotic limit yields precipitating quasi-geostrophic equations with phase changes. Facilitated by its zero-frequency eigenvalue, the balanced component can be found by potential vorticity(PV) inversion, by solving an elliptic partial differential equation(PDE), which includes Heaviside discontinuities due to phase changes. The method is also compared with two simpler methods: one which neglects phase changes, and one which simply treats the raw pressure data as a streamfunction. Tests are shown for both synthetic, idealized data and data from Weather Research and Forecasting(WRF) model simulations. In comparisons, the phase-change method and no-phase-change method produce substantial differences within cloudy regions, of approximately 5K in potential temperature, due to the presence of clouds and phase changes in the data. A theoretical justification is also derived in the form of a elliptic PDE for the differences in the two streamfunctions.

关键词： Potential vorticity inversion Moist atmospheric dynamics Slow-fast systems Balanced-unbalanced decomposition Elliptic partial differential equations

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DEEP-UV COnFOCAL FLUORESCEnCE IMAGInG AnD SUPER-RESOLUTIOn OPTICAL MICROSCOPY OF BIOLOGICAL SAMPLES

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Journal of Innovative Optical Health Sciences 2012年第4期5卷 24-32页

作者： TREVOR A.smith LIISA M.HIRVOnEn CRAIG n.LInCOLn XIAOTAO HAO School of Chemistry and ARC Centre of Excellence for Coherent X-ray Science University of Melbourne Parkville 3010Australia

A wide range of techniques has been developed to image biological samples at high spatial and temporal *** this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent emission from fuorophores such as tryptophan,and structured ilumination microscopy(SIM)of biological *** motivation for developing deep-UV fhuorescence imaging and SIM is to provide methods to complement our measurements in the emerging field of X-ray coherent diffractive imaging.

关键词： Time resolved fuorescence imaging structured ilumnina tion microscopy

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Phosphorus Uptake and Utilisation Efficiencies of Different Wheat Cultivars Based on a Sand-Culture Screening System

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Pedosphere 2002年第4期12卷 329-337页

作者： n.K.HOWES S.E.smith ZHUYOnGGUAn DepartmentofSoilandWater TheUniversityofAdelaideGlenOsmondSA5064（Australia） ResearchCentreforEco－EnvironmentalSciences theChineseAcademyofSciencesBeijing100085（China） SouthAustraliaResearchandDevelopmentInstitute GlenOsmondSA5064（Australia）

A sand-based culture system using rock phosphate (P) was developed to simulate the situation in alkalinesoils, with respect to the dominant P form, and five wheat cultivars (Excalibur, Brookton, Krichauff, Westoniaand Sunco) were tested in this screening system to compare their P uptake and utilisation efficiencies. Resultsshowed that these cultivars differed significantly in their ability to acquire P from the sparingly available form(rock phosphate in this case). The accumulation of P by Brookton was three times that by Krichauff. Pconcentrations in plant tissues did not differ significantly, indicating that all cultivars were similar in Putilisation efficiency. A further experiment showed that the greater ability of a cultivar to take up P fromsparingly available form was related to the ability of a cultivar to acidify the rhizosphere. Seed P content wasa confounding factor in this system, and the use of relatively uniform seed with similar P content, preferablylow, was conducive to a successful outcome of the screening process.

关键词： phosphorus efficiency sand-culture uptake wheat genotypes

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美国标准局的激光计量务业

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中国检验检测 1984年第6期 61-62页

作者： Collier n.smith 王新菊于允平

激光计量,在美国是由美国标准局的波尔德电磁技术处的光电计量室承担的。该室进行研究的宗旨是发展激光器参数的国家标准和计量业务,以促进国际国内贸易及激光技术与应用的全面发展。该室正在研究的参数有连续功率、脉冲能量和脉冲宽度... 详细信息

激光计量,在美国是由美国标准局的波尔德电磁技术处的光电计量室承担的。该室进行研究的宗旨是发展激光器参数的国家标准和计量业务,以促进国际国内贸易及激光技术与应用的全面发展。该室正在研究的参数有连续功率、脉冲能量和脉冲宽度、峰值脉冲功率、衰减现象以及光束分布。(美国标准局其余的一些室正在进

关键词：美国标准局光束激光器分解器粒子束光激射器电子器件卡计量热计激光计量激光功率

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Oxidative stress and male reproductive health

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Asian Journal of Andrology 2014年第1期16卷 31-38页

作者： Robert J Aitken Tegan B smith Matthew S Jobling Mark A Baker Geoffry n De Iuliis Priority Research Centre in Reproductive Science Discipline of Biological Sciences Faculty of Science and IT University of Newcastle Callaghan NSW 2308 Australia

One of the major causes of defective sperm function is oxidative stress, which not only disrupts the integrity of sperm DnA but also limits the fertilizing potential of these cells as a result of collateral damage to proteins and lipids in the sperm plasma membrane. The origins of such oxidative stress appear to involve the sperm mitochondria, which have a tendency to generate high leve｜s of superoxide anion as a prelude to entering the intrinsic apoptotic cascade. Unfortunately, these cells have very little capacity to respond to such an attack because they only possess the first enzyme in the base excision repair （BER） pathway, 8-oxoguanine glycosylase 1 （OGG1）. The latter successfully creates an abasic site, but the spermatozoa cannot process the oxidative lesion further because they lack the downstream proteins （APE1, XRCC1） needed to complete the repair process. It is the responsibility of the oocyte to continue the BER pathway prior to initiation of S-phase of the first mitotic division. If a mistake is made by the oocyte at this stage of development, a mutation will be created that will be represented in every cell in the body. Such mechanisms may explain the increase in childhood cancers and other diseases observed in the offspring of males who have suffered oxidative stress in their germ line as a consequence of age, environmental or lifestyle factors. The high prevalence of oxidative DnA damage in the spermatozoa of male infertility patients may have implications for the health of children conceived in vitro and serves as a driver for current research into the origins of free radical generation in the germ line.

关键词： DnA damage oxidative stress oxoguanine glycosylase 1 oocyte spermatozoa

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novel Heat Transfer Issues Associated with the Design and Safe Operation of the MEGAPIE Spallation Source Target

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Journal of Thermal Science 2007年第1期16卷 63-78页

作者： Brian L.smith Thermal Hydraulics Laboratory Paul Scherrer InstituteSwitzerland

Critical heat transfer problems are discussed in the context of the operation of a spallation source target, which represents a first demonstration of the feasibility of an innovative concept for generating energy using a particle accelerator. Within the framework of the umbrella project MEGAPIE, an R＆D support group was organized to take responsibility for target cooling. This involved the use of advanced numerical methods - Computational Fluid Dynamics （CFD） and Finite Element Method （FEM） - validated against suitable experimental data, and by means of appropriate benchmarking exercises. The design studies using CFD resulted in an optimum flow configuration being defined for the coolant circulation. Flow visualization tests were undertaken using a glass/water test section, with the velocity field mapped using optical and ultrasonic measuring techniques. These were followed by heat transfer tests, using the actual target materials （lead-bismuth-eutectic coolant and steel confinement）. Further CFD/FEM work to analyze operational transients and accident sequences was also carded out, and is described in the paper.

关键词： computational fluid dynamics finite element method liquid-metal coolant spallation source target

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Water balloon-induced orbital fracture in an aviator

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Military Medical Research 2020年第2期7卷 245-248页

作者： Timothy E.Holland David M.smith Guy n.Gibson Jared G.Brinkerhoff Flight and Operational Medical Clinic 78th Medical Group655 Seventh StreetRobins Air Force BaseRobinsGA 31098USA Department of Radiology Ehrling Bergquist Clinic2501 Capehart RdOffutt AFBNEOffutt 68113-2160USA Flight and Operational Medical Clinic 5th Medical Group194 Missilie AveMinot AFBNDMinot 58705USA

Background:Orbital fractures are common injuries found in facial *** etiologies of orbital fractures include motor vehicle collisions and *** report the case of a 32-year-old male who suffered an orbital fracture from a water ***,we describe the aeromedical complications that may result from this ***,we attempt to answer the question of when a patient may return to flying after sustaining such an injury through review of the *** presentation:A 32-year-old male pilot with the United States Air Force was at an outdoor event with his unit when he was struck with a water balloon launched from a sling shot into his left *** afterwards,he had an onset of subcutaneous emphysema and was escorted to a nearby Emergency *** tomography identified an orbital fracture with associated orbital and subcutaneous *** patient was evaluated by a plastic surgeon and was determined not to be a surgical *** weeks later,he returned to flying ***:Water balloons are thought to be safe and harmless ***,when coupled with sling shots,water balloons can become formidable projectiles capable of significant orbital injury including orbital *** injuries are concerning to aviators,as the most common sites for fractures of the orbit are the thin ethmoid and maxillary bones adjacent to the *** altitude,gases in the sinuses may expand and enter the orbit through these fractures,which may suddenly incapacitate the *** is important for flight surgeons to identify and assess these individuals to determine suitability for flying.

关键词： Boyle’s law Orbital emphysema Facial fracture

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Sex differences in the foraging behavior of a generalist hawkmoth

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Insect Science 2022年第1期29卷 304-314页

作者： Gordon P.smith Goggy Davidowitz Ruben Alarcón Daniel R.Papaj Judith L.Bronstein Department of Ecology and Evolutionary Biology University of ArizonaTucsonArizonaUSA Department of Entomology University of ArizonaTucsonArizonaUSA Department of Biology California State University Channel IslandsCamarilloCaliforniaUSA Current address:Department of neurobiology and Behavior Cornell UniversityIthacaNew YorkUSA

Within-species variation in pollinator behavior is widely observed, but its causes have been minimally investigated. Pollinator sex is associated with large differences in behavior that may lead to predictable differences in flower foraging, but this expectation has not been explicitly tested. We investigate sex-associated differences in nectar-foraging behavior of the hawkmoth Hyles lineata, using pollen on the proboscis as a proxy for flower visitation. We tested two predictions emerging from the literature: (1) the sexes differ in the flower species they visit, (2) females are more specialized in flower choice. We also examined potential drivers underlying these predictions by performing field and laboratory experiments to test whether males (3) switch among flower species more frequently, or (4) fly farther and therefore encounter more species than females. Consistent with prediction (1), pollen load composition differed between the sexes, indicative of visitation differences. Contrary to prediction (2), females consistently carried more species-rich pollen loads than males. (3) Both sexes switched between flower species at similar rates, suggesting that differences in floral fidelity are unlikely to explain why females are less specialized than males. (4) Males flew longer distances than females;coupled with larger between-site differences in pollen composition for females, this result suggests that sex differences in mobility influence foraging, and that females may forage more frequently and in smaller areas than males. Together, our results demonstrate that sex-associated foraging differences can be large and consistent over time, and highlight the importance of sex as a driver of variation in pollinator behavior.

关键词： hawkmoths intraspecific variation pollination sex differences

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