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Mutifactorial analysis of risk factors for reduced bone mineral density in patients with Crohn’s disease

World Journal of Gastroenterology 2006年第35期12卷 5680-5686页

作者： Sarah A Bartram Robert t Peaston david J Rawlings david Walshaw Roger M Francis Nick P thompson Musculoskeletal unit Freeman HospitalNewcastle-upon-Tyne United Kingdom Department of Biochemistry Freeman Hospital Newcastle-upon-Tyne United Kingdom Regional Medical Physics Department Newcastle General Hospital United Kingdom Dept of Statistics University of Newcastle upon Tyne United Kingdom Musculoskeletal unit Freeman Hospital Newcastle-upon-Tyne United Kingdom Department of Medicine Freeman Hospital Newcastle-upon-Tyne United Kingdom

AIM: to determine the prevalence of osteoporosis in a cohort of patients with Crohn’s disease (CD) and to identify the relative significance of risk factors for osteoporosis. MEtHODS: two hundred and fifty-eight unselected patients (92 M, 166 F) with CD were studied. Bone mineral density (BMD) was measured at the lumbar spine and hip by dual X-ray absorptiometry. Bone formation was assessed by measuring bone specific alkaline phosphatase (BSAP) and bone resorption by measuring urinary excretion of deoxypyridinoline (DPD) and N-telopeptide (NtX). RESULtS: Between 11.6%-13.6% patients were osteoporotic (t score t the lumbar spine and/or hip. NtX levels were significantly higher in the patients with osteoporosis (P t BSAP and DPD levels were not significantly different. Independent risk factors for osteoporosis at either the lumbar spine or hip were a low body mass index (P ticosteroid use (P these factors combined accounted for 23% and 37% of the reduction in BMD at the lumbar spine and hip respectively. CONCLUSION: Our results confirm that osteoporosis is common in patients with CD and suggest that increased bone resorption is the mechanism responsible for thebone loss. However, less than half of the reduction in BMD can be attributed to risk factors such as corticosteroid use and low BMI and therefore remains unexplained.

关键词： Crohn's disease Osteoporosis Osteopenia Bone mineral density

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Using a stand-level model to predict light absorption in stands with vertically and horizontally heterogeneous canopies

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Forestry Studies in China 2014年第3期16卷 158-176页

作者： david I Forrester Ruben Guisasola Xiaolu tang Axel t Albrecht tran Lam Dong Guerric le Maire Chair of Silviculture Faculty of Environment and Natural ResourcesFreiburg University Chair of Forest Inventory and Remote Sensing Georg-August-Universitt Gttingen Forest Research Institute of Baden-Wrttemberg tasmanian Institute of Agriculture(tIA) Vietnamese Academy of Forest Sciences Silviculture Research Institute CIRAD UMR Eco & Sols2 Place VialaMontpellier 34060France

Background： Forest ecosystem functioning is strongly influenced by the absorption of photosynthetically active radiation （APAR）, and therefore, accurate predictions of APAR are critical for many process-based forest growth models. the Lambert-Beer law can be applied to estimate APAR for simple homogeneous canopies composed of one layer, one species, and no canopy gaps. However, the vertical and horizontal structure of forest canopies is rarely homogeneous. Detailed tree-level models can account for this heterogeneity but these often have high input and computational demands and work on finer temporal and spatial resolutions than required by stand-level growth models. the aim of this study was to test a stand-level light absorption model that can estimate APAR by individual species in mixed-species and multi-layered stands with any degree of canopy openness including open-grown trees to closed canopies. Methods： the stand-level model was compared with a detailed tree-level model that has already been tested in mixed-species stands using empirical data. Both models were parameterised for five different forests, including a wide range of species compositions, species proportions, stand densities, crown architectures and canopy structures. Results： the stand-level model performed well in all stands except in the stand where extinction coefficients were unusually variable and it appears unlikely that APAR could be predicted in such stands using （tree- or stand-level） models that do not allow individuals of a given species to have different extinction coefficients, leaf-area density or analogous parameters. Conclusion： this model is parameterised with species-specific information about extinction coefficients and mean crown length, diameter, height and leaf area. It could be used to examine light dynamics in complex canopies and in stand-level growth models.

关键词： Complex forests Mixed-species Stand structure Extinction coefficient Lambert-Beer law Light absorption

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Erodibility study of sediment in a fast-flowing river

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International Journal of Sediment Research 2019年第2期34卷 144-154页

作者： Cheng He david Nguyen Watershed Hydrology and Ecology Research Division National Water Research InstituteEnvironment and Climate Change Canada Department of Environmental Engineering University of Guelph

Determination of sediment stability in the field is challenging because bed shear stress(BSS),a determining factor of sediment erosion,can’t easily be directly *** tackle this challenge and reliably assess sediment erodibility in a fast flowing river,a standalone underwater camera system and a new insitu flume(ISF)were developed and applied in this *** camera system was used to record sediment movement and the new ISF was used for measuring critical bottom shear stress(CBSS).the camera can be deployed alone in water to record videos or take pictures with light emitting diode(LED)lighting and flexible schedule *** ISF is based on the concept that the amount of force needed to erode the same particle under different flow conditions should be *** high resolution Acoustic Doppler Current Profilers(ADCP)also were deployed in the field to collect velocity-depth profiles which are used by conventional methods to calculate BSS with the law of the *** sediment erodibility was then assessed based on the comparison between the obtained CBSS and BSS and then further verified with the recorded observations from the deployed *** results reveal that the widely used conventional method can produce large uncertainties and is not adequate to provide meaningful conclusion under these conditions.

关键词： Sediment erodibility Bed shear stress Critical bed shear stress Underwater camera

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t lymphocyte apoptosis induced by CD8ε chimera

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Chinese Science Bulletin 1997年第3期42卷 222-227页

作者： david Perkins Cox terhorst Harvard Medical School BostonMAUSAHarvard Medical SchoolBostonMAUSA

tHE t cell repertoire is characterized by an extremely diverse population of different surface receptors (tCR) which participates in highly specific responses to a large number of different antigens and mediate antigen stimulation signals. Variable heterodimers of tCR α/β and γ/δ receptors are associated with invariable CD3γ, δ, ε and ζ proteins, thus forming the tCR/CD3 complex. CD3ε plays an important role in the initiation of tCR resembling and signfal transduction among the octopeptide chains. Stimulation by anti-CD3ε monoclonal

关键词： t lymphocyte apoptosis CD8ε chimera.

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Blast waveform tailoring using controlled venting in blast simulators and shock tubes

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Defence technology（防务技术） 2024年第7期37卷 14-26页

作者： Edward Chern Jinn Gan Alex Remennikov david Ritzel Faculty of Engineering and Information Sciences University of WollongongWollongongNSW2522Australia Dyn-FX Consulting Ltd 19 Laird Ave NorthAmherstburgONN9V 2T5Canada

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive *** tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance *** wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific *** paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube *** use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid *** venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast *** control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast *** paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

关键词： Advanced blast simulator Shock wave propagation Far-field explosion Blast loads Blast waves Computational fluid dynamics

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Macrophages and the maintenance of homeostasis

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Cellular & Molecular Immunology 2021年第3期18卷 579-587页

作者： david M.Mosser Kajal Hamidzadeh Ricardo Goncalves the Department of Cell Biology and Molecular Genetics The University of MarylandCollege ParkMD 20742USA the Department of General Pathology Federal University of Minas GeraisBelo HorizonteMGBrazil

there have been many chapters written about macrophage *** chapters generally focus on the role of macrophages in orchestrating immune responses by highlighting the t-cell-derived cytokines that shape these polarizing *** bias toward immunity is understandable,given the importance of macrophages to host ***,macrophages are ubiquitous and are involved in many different cellular processes,and describing them as immune cells is undoubtedly an *** disregards their important roles in development,tissue remodeling,wound healing,angiogenesis,and metabolism,to name just a few *** this chapter,we propose that macrophages function as transducers in the *** to Wikipedia,WA transducer is a device that converts energy from one form to another.^the word transducer is a term used to describe both the"sensor,which can interpret a wide range of energy forms,and the"actuator,which can switch voltages or currents to affect the *** are able to sense a seemingly endless variety of inputs from their environment and transduce these inputs into a variety of different response ***,rather than functioning as immune cells,they should be considered more broadly as cellular transducers that interpret microenvironmental changes and actuate vital tissue *** this chapter,we will describe some of the sensory stimuli that macrophages perceive and the responses they make to these stimuli to achieve their prime directive,which is the maintenance of homeostasis.

关键词： Macrophages polarization cytokines development inflammation

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topological circuit of a versatile non-Hermitian quantum system

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Science China(Physics,Mechanics & Astronomy) 2022年第1期65卷 53-60页

作者： david-Andres Galeano Xiao-Xiao Zhang Jorge Mahecha Instituto de F´ısica Facultad de Ciencias Exactas y NaturalesUniversidad de AntioquiaMedell´ın 050010Colombia Unidad transacciones t&D Energ´ıa Gerencia Comercial T&D Energ´ıaV.P.T&D Energ´ıaEPMMedell´ın 050015Colombia Department of Physics and Astronomy&Stewart Blusson Quantum Matter Institute University of British ColumbiaVancouver V6T 1Z4Canada RIKEN Center for Emergent Matter Science(CEMS) Saitama 351-0198Japan Department of Chemistry University of British ColumbiaVancouver V6T 1Z4Canada

We propose a resistors,inductors and capacitors(RLC)electrical circuit to theoretically analyze and fully simulate a new type of non-Hermitian Su-Schrieffer-Heeger(SSH)model with complex *** formulate its construction and investigate its properties by taking advantage of the circuit’s *** physical properties can be identified in this system from the normal modes of oscillation of the RLC circuit,including the highly tunable bulk-edge correspondence between topological winding numbers and edge states and the non-Hermitian skin phenomenon originating from a novel complex energy plane *** present study is able to show the wide and appealing topological physics inherent to electric circuits,which is readily generalizable to a plenty of both Hermitian and non-Hermitian nontrivial systems.

关键词： topolectric circuit SSH model non-Hermitian topology skin effect

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Interaction of a Myrothecium verrucariaMycelial Preparation and a Glyphosate Product for Controlling Redvine (Brunnichia ovata) and trumpet Creeper (Campsis radicans)

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American Journal of Plant Sciences 2020年第2期11卷 201-213页

作者： Clyde Douglas Boyette Robert E.Hoagland Charles t.Bryson Mark A.weaver Kenneth C.Stetina USDA-ARS Biological Control of Pests Research UnitStonevilleMSUSA USDA-ARS Crop Production and Systems Research UnitStonevilleMSUSA

A mycelial formulation of the bioherbicidal fungus Myrothecium verrucaria (Alb. & Schwein.) Ditmar: Fr. (MV) was tested alone and in combination with a commercially available glyphosate [N-(phosphonomethyl)glycine] (GLY) product for controlling the invasive vines, redvine [Brunnichia ovata (Walt.) Shinners], and trumpet creeper [Campsis radicans (L.) Seem. ex Bureau] in field experiments conducted near Stoneville, MS. Several application timing regimens were evaluated (Fall, Spring, Fall + Spring, and Spring + Fall). We found that a Fall + Spring application of MV + GLY controlled redvine and trumpet creeper by 95%, 12 days after the second treatment, through a synergistic interaction of the fungus and glyphosate. Disease symptomatology was characterized by rapid necrosis of leaf and stem tissues, with mortality occurring within 72 h. Neither glyphosate alone, nor MV alone, effectively controlled either weed species under any application timing regimen. No visual disease or herbicide damage occurred on glyphosate-resistant soybean plants in the treated test plots. these results suggest that some formulations of glyphosate, mixed with the bioherbicide MV, can effectively control redvine and trumpet creeper, two of the most troublesome weeds in the row crops of the Mississippi Delta region in the mid-southern U.S.

关键词： Bioherbicide Interaction Mycelial Formulation Myrothecium verrucaria Campsis radicans Brunnichia ovata

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定量古生物学软件PASt及其常用功能

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古生物学报 2013年第2期52卷 161-181页

作者：黄冰 david A t Harper φyvind Hammer 现代古生物学和地层学国家重点实验室中国科学院南京地质古生物研究所南京210008 Department of Earth Sciences Durham UniversityDurham DH1 3LEUK Natural History Museum University of OsloP.O.Box 1072 Blindern 0316 OsloNorway

近半个世纪以来,古生物学涉及越来越复杂的现象与过程,难以用传统的经验科学方法来解决。伴随着相关研究引入日益增多的定量分析,古生物学逐渐成为一门可定量分析的科学。作为最早的古生物学专用的免费统计软件包,PASt功能全面、易于使... 详细信息

近半个世纪以来,古生物学涉及越来越复杂的现象与过程,难以用传统的经验科学方法来解决。伴随着相关研究引入日益增多的定量分析,古生物学逐渐成为一门可定量分析的科学。作为最早的古生物学专用的免费统计软件包,PASt功能全面、易于使用,并在过去十几年中发展迅速,目前已在相关软件中占据重要地位。本文在简单介绍该软件基本操作方法的基础上,结合古生物学应用案例,解读最常用到的几类"常规统计分析"与"多元统计分析"的使用;同时,针对古生物学相关领域中的"多样性、丰度及居群结构","形态学"和"生物地层学"问题,给出具体分析实例。在相关案例的分析介绍中,详细梳理用PASt实现这些分析的具体步骤,因而具有较好的实用参考价值。受篇幅所限,文章对软件中其他不常用但相对重要的9个模块只进行简要介绍,以供读者在偶尔涉及该类分析时参考。PASt软件不仅功能强大,而且能够针对古生物学及地层学浮现出来的最新前沿问题不断进行调整、更新,值得在古生物学界推广使用。

关键词： PASt软件定量古生物学多元统计多样性丰度形态学生物地层学

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Recommendations for the use of the acetaminophen hepatotoxicity model for mechanistic studies and how to avoid common pitfalls

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Acta Pharmaceutica Sinica B 2021年第12期11卷 3740-3755页

作者： Hartmut Jaeschke Olamide B.Adelusi Jephte Y.Akakpo Nga t.Nguyen Giselle Sanchez-Guerrero david S.Umbaugh Wen-Xing Ding Anup Ramachandran Department of Pharmacology Toxicology&TherapeuticsUniversity of Kansas Medical CenterKansas CityKS 66160USA

Acetaminophen(APAP)is a widely used analgesic and antipyretic drug,which is safe at therapeutic doses but can cause severe liver injury and even liver failure after *** mouse model of APAP hepatotoxicity recapitulates closely the human *** a result,this clinically relevant model is frequently used to study mechanisms of drug-induced liver injury and even more so to test potential therapeutic ***,the complexity of the model requires a thorough understanding of the pathophysiology to obtain valid results and mechanistic information that is translatable to the ***,many studies using this model are flawed,which jeopardizes the scientific and clinical *** purpose of this review is to provide a framework of the model where mechanistically sound and clinically relevant data can be *** discussion provides insight into the injury mechanisms and how to study it including the critical roles of drug metabolism,mitochondrial dysfunction,necrotic cell death,autophagy and the sterile inflammatory *** addition,the most frequently made mistakes when using this model are ***,considering these recommendations when studying APAP hepatotoxicity will facilitate the discovery of more clinically relevant interventions.

关键词： Acetaminophen hepatotoxicity Drug metabolism Mitochondria Apoptosis Ferroptosis Autophagy NRF2 Innate immunity

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