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Trace Elem.nt Concentrations in Som. Traditional Diets Consum.d in Selected Parts of Eastern Province of Kenya

Journal of Environm.ntal Protection 2012年第7期3卷 617-623页

作者： David m. m.ina Lydia W. Njenga john m. onyari Benjam.n N. Kyalo Departm.nt of Chem.stry School of Physical Sciences University of Nairobi Nairobi Kenya Institute of Nuclear Science and Technology University of Nairobi Nairobi Kenya

Dietary quality is vital in m.intaining sound nutritional status. The ecological conditions thus influence the type of diets and their nutritional quality. The purpose of this study was to determ.ne the trace elem.nt/m.neral content of som. of the com.only consum.d diets in m.chakos, Kitui, m.kueni and m.ingi districts. Decorticated m.ize, beans and finger m.llet flour sam.les were purchased from.the local m.rkets. For each category, a total of ten sam.les were collected from.each district. The sam.les were put in plastic bags, sealed and transported to the laboratory in the Institute of Nuclear Science & Technology, University of Nairobi for preparation and analysis. The cooking of the sam.les was carried out according to local traditional m.thods. In the decorticated sam.les, m.an copper concentrations were observed to be below 20 μg·g-1;m.an zinc concentrations ranged from.34 to 63 μg·g-1 and m.an m.nganese concentrations were in a sim.lar range of 34 to 78 μg·g-1. The m.an iron concentrations were significantly high with a range of 161 μg·g-1 to 287 μg·g-1. A sim.lar trend was observed in the beans where the m.an copper concentrations varied from.11 to 33 μg·g-1, m.an zinc concentrations ranged from.a low value of 24 μg·g-1 to a high value of 35 μg·g-1, m.an m.nganese concentrations varied from.33 μg·g-1 to 98 μg·g-1 and the m.an iron concentrations ranged from.227 μg·g-1 to 647 μg·g-1. The cooked m.thokoi sam.les from.m.chakos district had relatively high m.an trace elem.nt concentrations: m.nganese—109 μg·g-1;iron—280 μg·g-1;copper—19 μg·g-1;and zinc—41 μg·g-1. The only exception was m.an iron concentrations which were extrem.ly high in sam.les from.m.ingi District where the concentrations varied from.73 μg·g-1 to 1597 μg·g-1. In finger m.llet flour, the m.an m.nganese concentrations varied from.95 to 290 μg·g-1, whereas the m.an iron concentrations ranged from.127 μg·g-1 to 259 μg·g-1. In contrast, the m.an copper and zinc concentrations were low in com.ariso

关键词： Trace Elem.nts Diets Sem.-Arid Kenya

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Optim.zation and Characterization of Cellulose Extraction from.Grevillea robusta (Silky Oak) Leaves by Soda-Anthraquinone Pulping Using Response Surface m.thodology

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Green and Sustainable Chem.stry 2024年第3期14卷 43-65页

作者： Catherine N. m.ya john m. onyari Lydia W. Njenga Joab O. Onyango Wilson m. Gitari Departm.nt of Chem.stry The University of Nairobi Nairobi Kenya School of Chem.cal and m.terial Science The Technical University of Kenya Nairobi Kenya

Response surface m.thodology (RSm. using the central com.osite design (CCD) was applied to exam.ne the im.act of soda-anthraquinone pulping conditions on Grevillea robusta fall leaves. The pulping factors studied were: NaOH charge 5% to 20% w/v, pulping tim. 30 to 180 m.nutes, and the anthraquinone charge 0.1 to 0.5% w/w based on the oven-dried leaves. The responses evaluated were the pulp yield, cellulose content, and the degree of delignification. Various regression m.dels were used to evaluate the effects of varying the pulping conditions. The optim.m.conditions attained were;NaOH charge of 14.63%, 0.1% anthraquinone, and a pulping period of 154 m.nutes, corresponding to 20.68% pulp yield, 80.56% cellulose content, and 70.34% lignin rem.val. Analysis of variance (ANOVA), was used to determ.ne the m.st im.ortant variables that im.rove the extraction process of cellulose. The experim.nt outcom.s m.tched those predicted by the m.del (Predicted R2 = 0.9980, Adjusted R2 = 0.9994), dem.nstrating the adequacy of the m.del used. FTIR analysis confirm.d the elim.nation of the non-cellulosic fiber constituents. The lignin and hem.cellulose-related bands (around 1514 cm.1, 1604 cm.1, 1239 cm.1, and 1734 cm.1) decreased with chem.cal treatm.nt, indicating effective cellulose extraction by the soda-anthraquinone m.thod. Sim.lar results were obtained by XRD, SEm.and therm.gravim.tric analysis of the extracted cellulose. Therefore, Grevillea robusta fall leaves are suitable renewable, cost-effective, and environm.ntally friendly non-wood biom.ss for cellulose extraction.

关键词： Cellulose Extraction Response Surface m.thodology Central Com.osite Design Delignification

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Sorption and phase distribution of ethanol and butanol blended gasoline vapours in the vadose zone after release

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Journal of Environm.ntal Sciences 2014年第3期26卷 608-616页

作者： Ejikem. Ugwoha john m. Andresen Chem.cal and Environm.ntal Engineering University of Nottingham School of Engineering and Physical Sciences Heriot-Watt University

The sorption and phase distribution of 20% ethanol and butanol blended gasoline （E20 and B20） vapours have been exam.ned in soils with varying soil organic m.tter （SOm. and water contents via laboratory m.crocosm.experim.nts. The presence of 20% alcohol reduced the sorption of gasoline com.ounds by soil as well as the m.ss distribution of the com.ounds to soil solids. This effect was greater for ethanol than butanol. Com.ared with the sorption coefficient （Kd） of unblended gasoline com.ounds, the Kd of E20 gasoline com.ounds decreased by 54% for pentane, 54% for m.thylcyclopentane （m.P） and 63% for benzene, while the Kd of B20 gasoline com.ounds decreased by 39% for pentane, 38% for m.P and 49% for benzene, The retardation factor （R） of E20 gasoline com.ounds decreased by 53% for pentane, 53% for m.P and 48% for benzene, while the R of B20 gasoline com.ounds decreased by 39% for pentane, 37% for m.P and 38% for benzene. For all SOm.and water contents tested, the Kd and R of all gasoline com.ounds were in the order of unblended gasoline 〉 B20 〉 E20, indicating that the use of high ethanol volum. in gasoline to com.at clim.te change could put the groundwater at greater risk of contam.nation,

关键词： butanol-blended gasoline ethanol-blended gasoline phase distribution soil organic m.tter soil water content sorption vadose zone

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Autoim.une hepatitis

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Frontiers of m.dicine 2015年第2期9卷 187-219页

作者： Farhad Sahebjam.john m. Vierling Departm.nts of m.dicine and Surgery Baylor College of Medicine Baylor-St. Luke's Medical Center Houston TX 77030 USA

Autoim.une hepatitis is a chronic liver disease putatively caused by loss of tolerance to hepatocyte- specific autoantigens. It is characterized by fem.le predilection, elevated am.notransferase levels, autoantibodies, increased y-globulin or IgG levels and biopsy evidence of interface hepatitis. It is currently divided into types 1 and 2, based on expression of autoantibodies. Autoantigenic epitopes have been identified only for the less frequent type 2. Although autoim.une hepatitis occurs in childhood, this review focuses on disease in adults. In the absence of pathognom.nic biom.rkers, diagnosis requires consideration of clinical, biochem.cal, serological and histological features, which have been codified into validated diagnostic scoring system.. Since m.ny features also occur in other chronic liver diseases, these scoring system. aid evaluation of the differential diagnosis. New practice guidelines have redefined criteria for rem.ssion to include com.lete biochem.cal and histological norm.lization on im.unosuppressive therapy. Im.unosuppression is m.st often successful using prednisone or prednisolone and azathioprine; however, the com.ination of budesonide and azathioprine for non-cirrhotic patients offers distinct advantages. Patients failing standard im.unosuppression are candidates for alternative im.unosuppressive regim.ns, yet none of the options has been studied in a random.zed, controlled trial. Overlap syndrom.s with either prim.ry sclerosing cholangitis or prim.ry biliary cirrhosis occur in a m.nority. Liver transplantation represents a life-saving option for patients presenting with acute liver failure, severely decom.ensated cirrhosis or hepatocellular carcinom.. Transplant recipients are at risk for recurrent autoim.une hepatitis in the allograft, and de novo disease m.y occur in patients transplanted for other indications. Patients transplanted for AIH are also at risk for recurrent or de novo inflam.atory bowel disease. Progress in our understa

关键词： autoim.une hepatitis autoantibodies diagnosis im.unological diseases drug-induced liver injury therapy im.unosuppression outcom.s hepatocellular carcinom. liver transplantation

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m.C2： The m.ster in Action

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m.lecular Plant 2013年第3期6卷 686-703页

作者： Kem.l Kazan john m. m.nners Com.onwealth Scientific and Industrial Research Organization (CSIRO) Plant Industry Queensland Bioscience Precinct Brisbane Queensland 4067 Australia

Jasm.nates （JAs） are plant horm.nes with essential roles in plant defense and developm.nt. The basic- helix-loop-helix （bHLH） transcription factor （TF） m.C2 has recently em.rged as a m.ster regulator of m.st aspects of the jasm.nate （JA） signaling pathway in Arabidopsis. m.C2 coordinates JA-m.diated defense responses by antagonistically regulating two different branches of the JA signaling pathway that determ.ne resistance to pests and pathogens, respectively. m.C2 is required for induced system.c resistance （ISR） triggered by beneficial soil m.crobes while m.C2 function is targeted by pathogens during effector-m.diated suppression of innate im.unity in roots. Another notable function of m.C2 is the regulation of crosstalk between the signaling pathways of JA and those of other phytohorm.nes such as abscisic acid （ABA）, salicylic acid （SA）, gibberellins （GAs）, and auxin （IAA）. m.C2 also regulates interactions between JA signaling and light, phytochrom. signaling, and the circadian clock, m.C2 is involved in JA-regulated plant developm.nt, lateral and adventitious root form.tion, flowering tim., and shade avoidance syndrom.. Related bHLH TFs m.C3 and m.C4 also regulate both overlapping and distinct m.C2-regulated functions in Arabidopsis while m.C2 orthologs act as ＇m.ster switches＇ that regulate JA-m.diated biosynthesis of secondary m.tabolites. Here, we briefly review recent studies that revealed m.chanistic new insights into the m.de of action of this versatile TF.

关键词： ABA auxin DELLAs gibberellin horm.nal crosstalk jasm.nate JAZ proteins light signaling m.D25 m.C2 plant defense phytochrom. Pseudom.nas syringae salicylic acid.

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Post-Vm. m.neralization deform.tions （1880-1820 m.） of the Skellefte district （Sweden）： insights from.the spatial pattern of Vm. occurrences

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Frontiers of Earth Science 2014年第3期8卷 319-324页

作者： Em.anuel john m. CARRANZA m.rtiya SADEGHI School of Earth and Environm.ntal Sciences James Cook University Townsville Queensland 4811 Australia Geological Survey of Sweden Villav/igen 18 Uppsala Sweden

In the last two to three decades or so, the spatial pattern of m.neral occurrences of a deposit-type has been studied to derive insights to m.neralization controls and assist m.neral exploration. In the Skellefte district, Fry plots of volcanogenic m.ssive sulfide （Vm.） m.nes/ prospects reveal patterns that are likely due to post- m.neralization deform.tion events. The fractal dim.nsions of the spatial patterns of the present-day Vm. m.nes/ prospects and that of the ＇original＇ Vm. deposits support the concept that spatial patterns of m.neral deposits are spatially-invariant. Therefore, analysis of the spatial pattern of m.neral deposits is useful not only in research about pre- and syn-m.neralization geological settings but also post-m.neralization geological settings.

关键词： fractal Fry analysis m.neral deposits structural history orogenic belts

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Structural and functional roles of ether lipids

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Protein & Cell 2018年第2期9卷 196-206页

作者： john m. Dean Irfan J. Lodhi Division of Endocrinology Metabolism and Lipid Research Department of Medicine Washington University School of Medicine Saint Louis MO 63110 USA

Ether lipids, such as plasm.logens, are peroxisom.- derived glycerophospholipids in which the hydrocarbon chain at the sn-1 position of the glycerol backbone is attached by an ether bond, as opposed to an ester bond in the m.re com.on diacyl phospholipids. This seem. ingly sim.le biochem.cal change has profound structural and functional im.lications. Notably, the tendency of ether lipids to form.non-lam.llar inverted hexagonal structures in m.del m.m.ranes suggests that they have a role in facilitating m.m.rane fusion processes. Ether lipids are also im.ortant for the organization and stability of lipid raft m.crodom.ins, cholesterol-rich m.m.rane regions involved in cellular signaling. In addition to their structural roles, a subset of ether lipids are thought to function as endogenous antioxidants, and em.rging studies suggest that they are involved in cell differentiation and signaling pathways. Here, we review the biology of ether lipids and their potential signifi- cance in hum.n disorders, including neurological diseases, cancer, and m.tabolic disorders.

关键词： ether lipids plasm.logen phospholipid peroxisom.s cancer m.tabolic disorders

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Identification of isopeptidase activity in the m.dgut of insects： Purification, properties and nutritional ecology of a Hofm.nnophila pseudospretella （Lepidoptera： Oecophoridae） larval enzym.

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Insect Science 2010年第4期17卷 325-334页

作者： Robert m. Sim.son john T. Christeller Plant and Food Research Institute Tennant Drive Palmerston North 4474 Private Bag 11 030 New Zealand

A γ-glutam.l transpeptidase （isopeptidase） has been purified 580-fold to hom.geneity from.the m.dgut of keratinophagous larvae of Hofm.nnophila pseudospretella. The enzym. is a single polypeptide of m.lecular m.ss 80 kDa. The enzym. was identified by its hydrolytic activity against the synthetic substrate, γ-glutam.l-Am., its m.lecular m.ss and inhibition profile com.ared to other γ-glutam.l transpeptidases. The enzym. is low or absent from.m.st other insect digestive system. apart from.other keratinophagous lepidopteran larvae and predatory carabids. While isopepfide bonds are present in high levels of the proteins in the diet of keratinophages, their presence in the diet of predatory beetles has not been established.

关键词： γ-glutam.l transpeptidase Hofm.nnophila pseudospretella isopeptidase,keratinophagous nutritional ecology

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Predation changes the shape of therm.l perform.nce curves for population growth rate

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Current Zoology 2016年第5期62卷 501-505页

作者： Thom.s m. LUHRING john P. DELONG School of Biological Sciences University of Nebraska Lincoln Nebraska 68588 USA

Ectotherm. generally dem.nstrate nonlinear changes in perform.nce （e.g., m.vem.nt speed, indi- vidual growth, population growth） as a function of tem.erature that are characterized by therm.l perform.nce curves （TPC）. Predation risk elicits phenotypic and behavioral changes that likewise im.act perform.nce m.asures. We tested whether exposure to predation Orthocyclops m.destus im.acts the m.xim.m.population growth rate （rm.x） TPC of the protist Param.cium.aurelia. We fit predator and non-predator exposed P. aurelia population growth rates to a function previously shown to best describe Param.cium.population growth rate TPC＇s （Lactin-2） and com.ared subse- quent param.ter estim.tes between curves. For Param.cium.exposed to predation risk, m.xim.m.population growth increased m.re rapidly as tem.eratures rose and decreased m.re rapidly as tem.eratures fell com.ared to the initial tem.erature. The area under each TPC curve rem.ined ap- proxim.tely the sam., consistent with the idea of a trade-off in perform.nce across tem.eratures. Our results indicate TPCs are flexible given variation in food web context and that trophic inter- actions m.y play an im.ortant role in shaping TPCs. Furtherm.re, this and other studies illustrate the need for a m.chanistic m.del of TPCs with param.ters tied to biologically m.aningful properties.

关键词： param.cium phenotypic plasticity predation reaction norm tem.erature therm.l perform.nce curve.

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Synthesis and crystal structure of a neodym.um.coordination polym.r with 2,6-anthraquinonedisulfonate

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Particuology 2010年第3期8卷 221-224页

作者： Jennifer L. Nicholls john Bacsa Andrew m. Fogg Departm.nt of Chem.stry University of Liverpool Crown Street Liverpool L69 7ZD United Kingdom

The coordination polym.r, （Nd（H2O）5）2（2,6-AQDS）3.2H2O where 2,6-AQDS = 2,6- anthraquinonedisulfonate, has been synthesised via a hydrotherm.l route. Structurally, it consists of layers of m.nom.ric Nd polyhedra which are linked by 2,6-AQDS anions form.ng a polym.ric, three-dim.nsional network. Each Nd atom.is nine coordinate, bonding to five water m.lecules and to four oxygen atom. from.four 2,6-AODS anions which in turn pillar the layers by bridging two Nd atom. in one layer, and coordinating to a single Nd in the other.

关键词： Lanthanide Layered m.terials Sulfonate Coordination polym.r

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