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chemical forms and extractability of iron in sediments of three contrasting lakes of china and UK

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Journal of Environmental Sciences 2003年第06期15卷 728-733页

作者： Gibson c.E.,stewart B.M. Key laboratory of Terrestrial Ecological Process Institute of Applied Ecology chinese Academy of Sciences Department of Agricultural and Environmental Science Queen's University Belfast Shenyang 110016 china Newforge lane Belfast BT9 5PX UK

Iron is a limiting factor for the eutrophication of lakes, especially those lakes that are enriched with phosphorus. Extractability of iron in sediments of West lake and Taihu lake in china and lower lough Erne in Northern Ireland of UK was comparatively investigated on the basis of analysing chemical forms of iron using different extractants. It was shown that extractable iron in sediments of the lakes was greatly different using various extractants. Reactive iron or easily released iron such as “active" iron oxides, total free iron oxide and water-soluble iron was not high, only accounting for 0.01%—0.15% of total iron. The efficiency of the extractants for exchangeable iron was decreased in the sequence 0.1 mol/l Hcl DTPA+TEA mixed solution > 1 mol/l NH 4OAc > 0.5 mol/l Mgcl 2 = 0.5 mol/l cacl 2. It seems that the complexion of iron by organic matter was not strong because the concentration of organically bound iron was significantly lower than the concentration it was forecasted. Extractable iron is not entirely consistent with or dependent on total iron in lake sediments. To a certain extent, phosphate can inhibit the release of iron in sediments of the lakes. The selection of extractants is thus the first key step to evaluate bioavailability of iron in lake sediments.

关键词： iron chemical form extractability lake sediment eutrophication

Evaluation of the Oxidation Reactivity and Behavior of Exhaust Soot Particles from Diesel Engines with Different Emission levels

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china Petroleum Processing & Petrochemical Technology 2024年第2期26卷 72-80页

作者： Wang Yajun lin lei Xing Jianqiang lüXu Yang He Song Haiqing SINOPEc Research Institute of Petroleum Processing co. Ltd.Beijing 100083China State Key laboratory of Engines Tianjin UniversityTianjin 300072China

The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel *** samples from two diesel engines(1K,cy4102)with different emission levels were collected by a thermophoretic system and a quartz *** oxidation reactivity,oxidation behaviors,and physicochemical properties of the PM samples were analyzed using thermogravimetric analysis(TGA),high-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectrometry(FTIR),and Raman *** results showed that there was a great difference in the oxidation reactivity of soot particles emitted by the two different diesel engines.A qualitative analysis of the factors influencing oxidation reactivity showed that the nanostructure,degree of graphitization,and relative concentration of aliphatic c—H functional groups were the most important factors,whereas no significant correlation was found between the primary particle size and activation energy of the diesel *** on the oxidation behavior analysis,the diesel soot particles exhibited both internal and surface oxidation modes during the oxidation *** oxidation was dominant during the initial stage,and as oxidation progressed,the mode gradually changed to internal *** oxidation mode of soot particles from the 1K engine was significantly higher than that of cy4102.

关键词： diesel engine soot particles oxidation reactivity oxidation behavior

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Estrogen enhances the functions of cD4^(+)cD25^(+)Foxp3^(+) regulatory T cells that suppress osteoclast differentiation and bone resorption in vitro

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cellular & Molecular Immunology 2011年第1期8卷 50-58页

作者： cy luo l Wang c Sun DJ li laboratory for Reproductive Immunology Hospital and Institute of Obstetrics and GynecologyFudan University Shanghai Medical CollegeShanghaiChina Jiangsu Province Hospital the First Affiliated Hospital with Nanjing Medical UniversityNanjingChina Department of Obstetrics and Gynecology Affiliated HospitalHainan Medical CollegeHaikouChina

cross-talk has been shown to occur between the immune system and bone metabolism *** the present study,we investigated the impact of cD4^(+)cD25^(+)Foxp3^(+) regulatory T(Treg)cells on osteoclastogenesis and bone *** cells that were isolated and purified from peripheral blood mononuclear cells(PBMcs)of healthy adults inhibited both the differentiation of osteoclasts(Ocs)from human embryo bone marrow cells(BMcs)and the pit formation in a dose-dependent *** cell cocultures,the production levels of both interleukin-10(Il-10)and transforming growth factor-beta 1(TGF-β1)were proportionally upregulated as the ratio of Treg cells to BMcs was increased,and the inhibition of Oc differentiation and bone resorption by Treg cells was completely reversed by anti-Il-10 and anti-TGF-β1 *** of BMc and Treg cell cocultures with 17β-estradiol(E2)at concentrations between 10^(-7) and 10^(-9) mol/l suppressed Oc differentiation and bone resorption more efficiently than it did in cultures of BMcs alone;this enhanced suppression occurred via the stimulation of Treg cell Il-10 and TGF-b1 *** data suggest that Treg cells suppress Oc differentiation and bone resorption by secreting Il-10 and TGF-β1.E2 enhances the suppressive effects of Treg cells on Oc differentiation and bone resorption by stimulating Il-10 and TGF-β1 secretion from these ***,Treg cell-derived Il-10 and TGF-b1 are likely involved in the regulation of E2 on bone metabolism and represent potential therapeutic targets for the treatment of postmenopausal osteoporosis(PMO).

关键词： bone resorption osteoclast PMO regulatory T cells

Effects of tachyplesin on the morphology and ultrastructure of human gastric carcinoma cell line BGc-823

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World Journal of Gastroenterology 2000年第5期6卷 676-680页

作者： li QF Ou Yang Gl li cy Hong SG Xiamen Univ Coll Life Sci Cell Biol Lab Xiamen 361005 Fujian Province Peoples R China

AIM To investigate the morphological andultrastructural changes in the human gastriccarcinoma cell line BGc-823 after being treatedwith *** Tachyplesin was isolated from acidextracts of chinese horseshoe crab(Tachypleustridentatus)***-823 cells and thecells treated with 2.0mg/l tachyplesin wereexamined respectively under light microscope,scanning and transmission electron *** BGc-823 cells had undergone therestorational alteration in morphology andultrastructure after tachyplesin *** were as follows:the shape of cells wasunanimous,the volume enlarged and cellsturned to be flat and spread,the nucleo-cytoplasmic ratio lessened and nuclear shapebecame rather regular,the number of nucleolusreduced and its volume lessened,heter-chromatin decreased while euchromatinincreased in *** the cytoplasm,mitochondria grew in number with consistentstructure relatively,Golgi complex turned to betypical and well-developed,rough endoplasmicreticulum increased and *** microvilli at cellular surfacewere rare and the filopodia reduced whilelamellipodia increased at the cell *** Tachyplesin could alter themalignant morphological and ultrastructuralcharacteristics of human gastric carcinoma cellseffectively and have a certain inducing differen-tiation effect on human gastric carcinoma cells.

关键词： stomach neoplasms/ultrastructure horseshoe crabs stomach neoplasms tachyplesin microscopy electron cell morphology

Pyogenic liver abscess:An audit of 10 years’experience

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World Journal of Gastroenterology 2011年第12期17卷 1622-1630页

作者： Tony cy Pang Thomas Fung Jaswinder Samra Thomas J Hugh Ross c Smith Upper Gastrointestinal Surgical Unit Royal North Shore HospitalUniversity of SydneySt Leonards NSW 2065Australia

AIM:To describe our own experience with pyogenic liver abscesses over the past 10 years and investigate the risk factors associated with failure of initial percutaneous ***:A retrospective study of records of 63 PlA patients presenting between 1998 and 2008 to Australian tertiary referral centre,were *** and hydatid abscesses were ***,clinical,radiological,and microbiological characteristics,as well as surgical/radiological interventions,were ***:Sixty-three patients(42 males,21 females) aged 65(±14) years[mean±(SD) ]had prodromal symptoms for a median(interquartile range;IQR) of 7(5-14) *** 59%of patients were febrile at presentation;however,the serum c-reactive protein was elevated in all 47 in whom it was *** function tests were non-specifically abnormal.67%of patients had a solitary abscess,while 32%had>3 abscesses with a median(IQR) diameter of 6.3(4-9) *** organisms were:Streptococcus milleri 25%,Klebsiella pneumoniae 21%,and Escherichia coli 16%.A presumptive cryptogenic cause was most common (34%).Four patients died in this series:one from sepsis,two from advanced cancer,and one from acute myocardial *** initial procedure was radiological aspiration±drainage in 54 and surgery in two patients.17%underwent surgical management during their *** hypoalbuminaemia[mean (95%cI) :32(29-35) g/l vs 28(25-31) g/l,P=0.045] on presentation was found to be the only factor related to failure of initial percutaneous therapy on univariate ***:PlA is a diagnostic challenge,because the presentation of this condition is *** antibiotics and radiological drainage in the first instance allows resolution of most PlAs;However,a small proportion of patients still require surgical drainage.

关键词： Pyogenic liver abscess Image guided drainage Surgical drainage c-reactive protein Hypoalbuminaemia

Improving bermudagrass in the Southeastern United States with alfalfa as an alternative nitrogen source in grazing systems

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Grassland Research 2022年第4期1卷 280-289页

作者： Justin c.Burt lisa l.Baxter christopher G.Prevatt Mary Kimberly Mullenix R.lawton stewart Jr. Jennifer J.Tucker Department of Animal and Dairy Science University of GeorgiaTiftonGeorgiaUSA Department of crop and Soil Science University of GeorgiaTiftonGeorgiaUSA Regional Specialized Agent Range Cattle RECUniversity of FloridaGainesvilleFloridaUSA Department of Animal Science Auburn UniversityAuburnAuburnUSA Department of Animal and Dairy Science University of GeorgiaAthensGeorgiaUSA

Background Bermudagrass(cynodon spp.)is one of the most common perennial warm-season forages grown in the Southeastern United *** incorporation of alfalfa(Medicago sativa)into bermudagrass pastures could serve as an alternative source of nitrogen(N)while also improving the nutritive value of the forage *** A 2-year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018(Year 1)and May–August 2019(Year 2)in Tifton,GA,*** objective was to compare the production of alfalfa–bermudagrass mixed pastures(BGA)with bermudagrass monoculture pastures with(BGN)or without(BG)the application of synthetic nitrogen on forage production and stocker cattle *** Differences were observed for average daily gain(p=0.10),gain per hectare(p=0.02)and stocking rate(p=0.01),in that BGA was greatest compared to BGN and BG,which did not differ from each ***,BGA had increased forage crude protein(p=0.01)and total digestible nutrients(p=0.01)compared to BGN and ***,BGA provided the greatest economic return per hectare compared to BG or *** These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.

关键词： alfalfa-bermudagrass mixtures forage management grazing management

Accurate Ground State Electronic and Related Properties of Hexagonal Boron Nitride (h-BN)

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Journal of Modern Physics 2020年第6期11卷 928-943页

作者： Y. Malozovsky c. Bamba A. stewart l. Franklin D. Bagayoko Department of Physics Southern University and A&M College Baton Rouge LA USA

We present an ab-initio, self-consistent density functional theory (DFT) description of ground state electronic and related properties of hexagonal boron nitride (h-BN). We used a local density approximation (lDA) potential and the linear combination of atomic orbitals (lcAO) formalism. We rigorously implemented the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF). The method ensures a generalized minimization of the energy that is far beyond what can be obtained with self-consistency iterations using a single basis set. The method leads to the ground state of the material, in a verifiable manner, without employing over-complete basis sets. We report the ground state band structure, band gap, total and partial densities of states, and electron and hole effective masses of hexagonal boron nitride (h-BN). Our calculated, indirect band gap of 4.37 eV, obtained with room temperature experimental lattice constants of a = 2.504 Å and c = 6.661 Å, is in agreement with the measured value of 4.3 eV. The valence band maximum is slightly to the left of the K point, while the conduction band minimum is at the M point. Our calculated, total width of the valence and total and partial densities of states are in agreement with corresponding, experimental findings.

关键词： Density Functional Theory Band Gap Density and Partial Density of States Electron and Hole Effective Masses

A systems approach to small group interaction / 8th ed.

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Sugarcane bagasse amendment mitigates nutrient leaching from a mineral soil under tropical conditions

2004年

作者： stewart l. Tubbs.

来源：畅想之星图书光盘版（南... 评论

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Pedosphere 2022年第6期32卷 876-883页

作者： Nan XU Jehangir H.BHADHA Abul RABBANY stewart SWANSON James MMccRAY Yuncong lI Sarah lSTRAUSS Rao MYlAVARAPU Horticultural Sciences Department University of FloridaGainesville FL 32611(USA) Everglades Research and Education center University of FloridaBelle Glade FL 33430(USA) Department of Soil Waterand Ecosystem SciencesUniversity of FloridaGainesville FL 32611(USA) Institute of Food and Agricultural Sciences(IFAS)Extension University of FloridaLaBelle FL 33935(USA) Agronomy Department University of FloridaBelle Glade FL 33430(USA) Department of Soil Waterand Ecosystem SciencesUniversity of FloridaHomestead FL 33031(USA) Department of Soil Waterand Ecosystem SciencesUniversity of FloridaImmokalee FL 34142(USA)

large quantities of organic by-products are generated by the sugarcane industry during sugar extraction *** by-products may be used as soil amendments to improve soil quality,as nutrient leaching is common in mineral soils of Florida in USA due to their sandy texture and frequent rain events.A soil column study was designed to evaluate the effects of bagasse application at 85 t ha^(-1) of fresh bagasse,170 t ha^(-1) of fresh bagasse,and 170 t ha^(-1) of fresh bagasse+nitrogen(N)on the leaching potential of carbon(c),N,phosphorus(P),and potassium(K).Bagasse was incorporated within the topsoil(0-15 cm)in outdoor soil columns exposed to natural conditions,with periodical irrigation during the *** approximately 57 weeks,the distributions of c,N,P,and K were evaluated at three soil depths(i.e.,0-15,15-30,and 30-53 cm)within the soil *** organic c(TOc),N,and P in leachates decreased significantly from the soils amended with bagasse compared with the control with no bagasse and no *** on K content changes in the columns,bagasse could also be utilized as a potential source of K for ***,application of bagasse as a soil amendment might be an effective way to sustainably reutilize organic by-products while reducing concerns regarding major nutrients entering groundwater *** results of this study could assist in developing nutrient management plans of using sugarcane bagasse as a potential soil amendment in mineral soils.

关键词： nutrient leaching potential nutrient loss pore volume sandy soil soil amendment soil column sugarcane by-product

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