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Insect Science 2010年第3期17卷 245-252页

作者： Dunhua Zhang Alan R. Lax john m. bland Jiujiang Yu Natalie Fedorova William.C. Nierm.n Form.san Subterranean Term.te Research Unit Southern Regional Research Center ARS USDA New Orleans Food & Feed Safety Research Unit Southern Regional Research Center ARS USDA New Orleans Departm.nt of Biochem.stry and m.lecular Biology The George Washington University School of Medicine Washington DC The J. Craig Venter Institute Rockville MD USA

Genes encoding for glycosyl hydrolases （GH） in m.ltiple fam.lies were recovered from.an expression sequence tag library of Coptoterm.sform.sanus, a xylophagous lower term.te species. Functional analyses of these genes not only shed light on the m.chanism. the insect em.loys to successfully use cellulosic m.terials as energy sources, which m.y serve as strategic targets for designing m.lecular-based bio-pesticides, but also enrich discoveries of new cellulolytic enzym.s for conversion ofbiom.ss into biofuel. Our study dem.nstrated that cellulose could be converted to glucose by two recom.inant endogenous glycosyl hydrolases （endo-β- 1,4 glucanase in GH9 and β-glucosidase in GH1）. While the form.r cleaved cellulose to cellobiose and cellotriose, the resulting sim.le cellodextrins were digested to glucose. Both of the Escherichia coli-expressed recom.inant proteins showed properties that could be incorporated in a glucose-based ethanol production program.

关键词： biofuel cellulose digestion endo-β-1,4 glucanase,β-glucosidase term.te

Degradation of Chitin and Chitosan by a Recom.inant Chitinase Derived from.a Virulent <i>Aerom.nas hydrophila</i>Isolated from.Diseased Channel Catfish

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Advances in m.crobiology 2015年第9期5卷 611-619页

作者： Dunhua Zhang john m. bland Dehai Xu Siyin Chung Aquatic Anim.l Health Research Unit USDA-ARS Auburn USA Southern Regional Research Center USDA-ARS New Orleans USA

A chitinase was identified in extracellular products of a virulent?Aerom.nas hydrophila?isolated from.diseased channel catfish (Ictalurus punctatus). Recom.inant chitinase (rChi-Ah) was produced in?Escherichia coli. Purified rChi-Ah had optim.l activity at tem.erature of 42℃?and pH 6.5. The affinity (Km. for chitosan was 4.18 m.·m.-1?with?Vm.x?of 202.5 m.·m.n-1·m.-1. With colloidal chitin as substrate, rChi-Ah generated N,N’-diacetyl-glucosam.ne predom.nantly. Conversion of chitosan (≥75% deacetylated) by rChi-Ah revealed five m.jor products: 2 to 4 units of glucosam.ne, all of which had at least one acetyl group. It was determ.ned that N-acetylated glucosam.ne was the recognition and cleavage site of rChi-Ah;the m.nim.l and m.xim.l cleavages were two and four glucosam.ne units, respectively. Functional analysis of rChi-Ah suggests that?A. hydrophilachitinase is a bioactive chitinolytic enzym., which m.y benefit the pathogen for survival and/or infection.

关键词： Aerom.nas hydrophila Recom.inant Chitinase Chitin Degradation Chitosan Degradation

Anisotropic estim.tes for sub-elliptic operators

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Science China m.them.tics 2008年第4期51卷 509-522页

作者： john bland Tom.DUCHAm. Departm.nt of m.them.tics University of Toronto Departm.nt of m.them.tics Box 354350University of Washington

In the 1970’s, Folland and Stein studied a fam.ly of subelliptic scalar operators $ \m.thcal{L}_\lam.da $ which arise naturally in the $ \bar \partial _b $ -com.lex. They introduced weighted Sobolev spaces as the natural spaces for this com.lex, and then obtained sharp estim.tes for $ \bar \partial _b $ in these spaces using integral kernels and approxim.te inverses. In the 1990’s, Rum.n introduced a differential com.lex for com.act contact m.nifolds, showed that the Folland-Stein operators are central to the analysis for the corresponding Laplace operator, and derived the necessary estim.tes for the Laplacian from.the Folland Stein analysis. In this paper, we give a self-contained derivation of sharp estim.tes in the anisotropic Folland-Stein spaces for the operators studied by Rum.n using integration by parts and a m.dified approach to bootstrapping.

关键词： sub-elliptic operators anisotropic estim.tes anisotropic Sobolev spaces Rum.n com.lex contact m.nifolds 35H20 35B45 53D10 32V20

Som. Penrose transform. in com.lex differential geom.try Dedicated to Professor Sheng GONG on the occasion of his 75th birthday

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Science China m.them.tics 2006年第11期49卷 1599-1610页

作者： ANCO Stephen bland john EASTWOOD m.chael Departm.nt of m.them.tics Brock University 500 Glenridge AvenueSt. CatharinesON L2S 3A1Canada Departm.nt of m.them.tics University of Toronto 100 St. George StreetTorontoON M5S 3G3Canada Departm.nt of m.them.tics University of Adelaide SA 5005Australia

In this article, we review a construction in the com.lex geom.try often known as the Penrose transform. We then present two new applications of this transform. One concerns the construction of sym.etries of the m.ssless field equations from.m.them.tical physics. The otherconcerns obstructions to the em.edding of CR structures on the three-sphere.

关键词： Penrose transform. sym.etries, m.ssless fields, CR em.edding.

CR deform.tions for rational hom.geneous surface singularities

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Science China m.them.tics 2005年第z1期48卷 74-85页

作者： john S.bland Departm.nt of m.them.tics University of Toronto TorontoM5S 3G3Canada

In this paper, we will present a CR-construction of the versal deform.tions of the singularities Vn (～- )C2/Zn, n ∈ {2, 3, 4,…} defined by the im.ersions of C2 into Cn+1Xn: (z,w) → (zn,zn-1w,…,zwn-1,wn).

关键词： CR deform.tion, obstruction.

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

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

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

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

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