Design of stereoselective Ziegler-Natta propene polymerization catalysts.

abstract：:To facilitate analysis of plant cell wall polysaccharide structure and composition, we cloned 74 genes encoding polysaccharide-degrading enzymes from Aspergillus nidulans, Aspergillus fumigatus, and Neurospora crassa and expressed the genes as secreted proteins with C-terminal Myc and 6x His tags. Most of the recombin...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bauer S,Vasu P,Persson S,Mort AJ,Somerville CR

更新日期：2006-07-25 00:00:00

abstract：:Like many other social phenomena, prostitution is increasingly coordinated over the Internet. The online behavior affects the offline activity; the reverse is also true. We investigated the reported sexual contacts between 6,624 anonymous escorts and 10,106 sex buyers extracted from an online community from its beginn...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rocha LE,Liljeros F,Holme P

更新日期：2010-03-30 00:00:00

abstract：:Maximum likelihood estimators and other direct optimization-based estimators dominated statistical estimation and prediction for decades. Yet, the principled foundations supporting their dominance do not apply to the discrete high-dimensional inference problems of the 21st century. As it is well known, statistical dec...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Carvalho LE,Lawrence CE

更新日期：2008-03-04 00:00:00

abstract：:The evolutionary process that occurs when a species colonizes a new environment provides an opportunity to explore the mechanisms underlying genetic adaptation, which is essential knowledge for understanding evolution and the maintenance of biodiversity. Atlantic herring has an estimated total breeding stock of about ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hill J,Enbody ED,Pettersson ME,Sprehn CG,Bekkevold D,Folkvord A,Laikre L,Kleinau G,Scheerer P,Andersson L

更新日期：2019-09-10 00:00:00

abstract：:Insect damage on fossil leaves from the Central Rocky Mountains, United States, documents the response of herbivores to changing regional climates and vegetation during the late Paleocene (humid, warm temperate to subtropical, predominantly deciduous), early Eocene (humid subtropical, mixed deciduous and evergreen), a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wilf P,Labandeira CC,Johnson KR,Coley PD,Cutter AD

更新日期：2001-05-22 00:00:00

abstract：:Highly purified globin mRNA from ducks was copied with RNA-directed DNA polymerase from avian myeloblastosis virus into anti-messenger DNA. With excess RNA, more than 90% of this DNA annealed back to its template with a C(o)t/2 value of 7.5 x 10(-4) mol.sec. liter(-1); the melting temperature of the hybrid was 86 degr...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Imaizumi T,Diggelmann H,Scherrer K

更新日期：1973-04-01 00:00:00

abstract：:We have found that the bacterial transposon Tn7 can recognize and preferentially insert adjacent to triple-helical nucleic acid structures. Both synthetic intermolecular triplexes, formed through the pairing of a short triplex-forming oligonucleotide on a plasmid DNA, and naturally occurring mirror repeat sequences kn...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rao JE,Miller PS,Craig NL

更新日期：2000-04-11 00:00:00

abstract：:Antagonists of growth hormone-releasing hormone (GH-RH) inhibit the growth of various tumors through mechanisms that involve the suppression of the insulin-like growth factor I and/or insulin-like growth factor II levels or secretion. In the present study, we tested the hypothesis that the tumor inhibition is associat...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kiaris H,Schally AV

更新日期：1999-01-05 00:00:00

abstract：:Upon stimulation with anti-CD3, suppressor T-cell (Ts) hybridomas and homologous transfectants of T-cell receptor a (TCRalpha) cDNA in the T-cell hybridoma formed a 55-kDa TCRalpha chain derivative that bound both the monoclonal anti-TCRalpha chain and polyclonal antibodies against glycosylation inhibiting factor (GIF...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ishii Y,Nakano T,Ishizaka K

更新日期：1996-07-09 00:00:00

abstract：:The mitochondrial genome of the S-type male-sterile cytoplasm of maize contains two linear episomes, S1 (6397 base pairs) and S2 (5453 base pairs). The S2 episome contains two large unidentified open reading frames, URF1 (3512 base pairs) and URF2 (1017 base pairs). We have demonstrated that a polypeptide with an appa...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Zabala G,O'brien-Vedder C,Walbot V

更新日期：1987-11-01 00:00:00

abstract：:Crises in science concern not only methods, statistics, and results but also, theory development. Beyond the indispensable refinement of tools and procedures, resolving crises would also benefit from a deeper understanding of the concepts and processes guiding research. Usually, theories compete, and some lose, incent...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ellemers N,Fiske ST,Abele AE,Koch A,Yzerbyt V

更新日期：2020-04-07 00:00:00

abstract：:Pancreatic ductal adenocarcinoma (PDAC) cells (PCC) have an exceptional propensity to metastasize early into intratumoral, chemokine-secreting nerves. However, we hypothesized the opposite process, that precancerous pancreatic cells secrete chemokines that chemoattract Schwann cells (SC) of nerves and thus induce read...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Demir IE,Kujundzic K,Pfitzinger PL,Saricaoglu ÖC,Teller S,Kehl T,Reyes CM,Ertl LS,Miao Z,Schall TJ,Tieftrunk E,Haller B,Diakopoulos KN,Kurkowski MU,Lesina M,Krüger A,Algül H,Friess H,Ceyhan GO

更新日期：2017-01-03 00:00:00

abstract：:We describe a synthetic ligand, "DAKLI" (Dynorphin A-analogue Kappa LIgand), related to the opioid peptide dynorphin A. A single reactive amino group at the extended carboxyl terminus permits various reporter groups to be attached, such as 125I-labeled Bolton-Hunter reagent, fluorescein isothiocyanate, or biotin. Thes...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Goldstein A,Nestor JJ Jr,Naidu A,Newman SR

更新日期：1988-10-01 00:00:00

abstract：:Thioredoxins are small multifunctional redox active proteins widely if not universally distributed among living organisms. In chloroplasts, two types of thioredoxins (f and m) coexist and play central roles in regulating enzyme activity. Reduction of thioredoxins in chloroplasts is catalyzed by an iron-sulfur disulfid...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Balmer Y,Koller A,del Val G,Manieri W,Schürmann P,Buchanan BB

更新日期：2003-01-07 00:00:00

abstract：:GSTs catalyze the conjugation of glutathione with a wide variety of hydrophobic compounds, generally resulting in nontoxic products that can be readily eliminated. In contrast to many other organisms, the malarial parasite Plasmodium falciparum possesses only one GST isoenzyme (PfGST). This GST is highly abundant in t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fritz-Wolf K,Becker A,Rahlfs S,Harwaldt P,Schirmer RH,Kabsch W,Becker K

更新日期：2003-11-25 00:00:00

abstract：:Mammalian cells present a fingerprint of their proteome to the adaptive immune system through the display of endogenous peptides on MHC-I complexes. MHC-I-bound peptides originate from protein degradation by the proteasome, suggesting that stably folded, long-lived proteins could evade monitoring. Here, we investigate...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Trentini DB,Pecoraro M,Tiwary S,Cox J,Mann M,Hipp MS,Hartl FU

更新日期：2020-02-25 00:00:00

abstract：:Misfolding and aggregation of Cu, Zn superoxide dismutase (SOD1) is implicated in neuronal death in amyotrophic lateral sclerosis. Each SOD1 monomer binds to 1 copper and 1 zinc ion and maintains its disulfide bond (Cys-57-Cys-146) in the reducing cytoplasm of cell. Mounting experimental evidence suggests that metal l...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ding F,Dokholyan NV

更新日期：2008-12-16 00:00:00

abstract：:Alzheimer's disease (AD) is characterized by a progressive dysfunction of central neurons. Recent experimental evidence indicates that in the cortex, in addition to the silencing of a fraction of neurons, other neurons are hyperactive in amyloid-β (Aβ) plaque-enriched regions. However, it has remained unknown what com...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Busche MA,Chen X,Henning HA,Reichwald J,Staufenbiel M,Sakmann B,Konnerth A

更新日期：2012-05-29 00:00:00

abstract：:The multifunctional DNA-binding protein (DBP) encoded by human adenovirus binds RNA. The association of purified DBP with RNA in vitro was demonstrated by using either a gel filtration or a filter binding assay. This association is sensitive to ionic strength and exhibits no apparent sequence specificity. DBP also int...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cleghon VG,Klessig DF

更新日期：1986-12-01 00:00:00

abstract：:Complementation of the plasmin fragments of reduced-carbamoylmethylated (Cam) human somatotropin (hGH) with those of reduced-carbamoylmethylated human chorionic somatomammotropin (hCS) have been investigated. It was found that the recombinant obtained by noncovalent interaction of [Cys(Cam)53]hGH-(1-134) with [Cys(Cam...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Li CH

更新日期：1978-04-01 00:00:00

abstract：:We determined the frequency of integrated viral DNA in the livers of three woodchucks chronically infected with the woodchuck hepatitis virus before and during 30 weeks of therapy with the nucleoside analog L-FMAU [1-(2-fluoro-5-methyl-beta, L-arabinofuranosyl)uracil, clevudine]. We found that although viral covalentl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Summers J,Mason WS

更新日期：2004-01-13 00:00:00

abstract：:In Saccharomyces cerevisiae, utilization of galactose requires four inducible enzyme activities. Three of these activities (galactose-1-phosphate uridyl transferase, EC 2.7.7.10; uridine diphosphogalactose 4-epimerase, EC 5.1.3.2; and galactokinase, EC 2.7.1.6) are specified by three tightly linked genes (GAL7, GAL10,...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hopper JE,Broach JR,Rowe LB

更新日期：1978-06-01 00:00:00

abstract：:CD31 is an Ig-like molecule expressed by leukocytes and endothelial cells with an established role in the regulation of leukocyte trafficking. Despite genetic deletion of CD31 being associated with exacerbation of T cell-mediated autoimmunity, the contribution of this molecule to T-cell responses is largely unknown. H...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ma L,Mauro C,Cornish GH,Chai JG,Coe D,Fu H,Patton D,Okkenhaug K,Franzoso G,Dyson J,Nourshargh S,Marelli-Berg FM

更新日期：2010-11-09 00:00:00

abstract：:The peroxidase-catalyzed aerobic oxidation of a linear aldehyde, leading to the next lower homologue in the triplet state, is accompanied by Norrish type II product ethylene when the substrate is pentanal. This system appears to provide an example of "photobiochemistry without light" because ethylene is a plant hormon...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Knudsen FD,Campa A,Stefani HA,Cilento G

更新日期：1994-01-04 00:00:00

abstract：:The mechanistic basis for chloroquine resistance (CQR) in Plasmodium falciparum recently has been linked to the polymorphic gene pfcrt. Alleles associated with CQR in natural parasite isolates harbor threonine (T), as opposed to lysine (K) at amino acid 76. P. falciparum CQR strains of African and Southeast Asian orig...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mehlotra RK,Fujioka H,Roepe PD,Janneh O,Ursos LM,Jacobs-Lorena V,McNamara DT,Bockarie MJ,Kazura JW,Kyle DE,Fidock DA,Zimmerman PA

更新日期：2001-10-23 00:00:00

abstract：:NKp46 is a cell surface receptor expressed on natural killer (NK) cells, on a minute subset of T cells, and on a population of innate lymphoid cells that produce IL-22 and express the transcription factor retinoid-related orphan receptor (ROR)-γt, referred to as NK cell receptor (NKR)(+)ROR-γt(+) cells. Here we descri...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Narni-Mancinelli E,Chaix J,Fenis A,Kerdiles YM,Yessaad N,Reynders A,Gregoire C,Luche H,Ugolini S,Tomasello E,Walzer T,Vivier E

更新日期：2011-11-08 00:00:00

abstract：:Development of spatial patterns in multicellular organisms depends on gradients in the concentration of signaling molecules that control gene expression. In the Drosophila embryo, Bicoid (Bcd) morphogen controls cell fate along 70% of the anteroposterior axis but is translated from mRNA localized at the anterior pole....

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gregor T,Bialek W,de Ruyter van Steveninck RR,Tank DW,Wieschaus EF

更新日期：2005-12-20 00:00:00

abstract：:Asian patients with chronic hepatitis C (CHC) are known to have better virological responses to pegylated (Peg) IFN-based therapy than Western patients. Although IL28B gene polymorphisms may contribute to this difference, whether favorable hepatitis C virus (HCV) kinetics during treatment plays a role remains unclear....

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hsu CS,Hsu SJ,Chen HC,Tseng TC,Liu CH,Niu WF,Jeng J,Liu CJ,Lai MY,Chen PJ,Kao JH,Chen DS

更新日期：2011-03-01 00:00:00

abstract：:There are many sources of genetic diversity, ranging from programmed mutagenesis in antibody genes to random mutagenesis during species evolution or development of cancer. We propose that mutations in DNA sequence-specific transcription factors that target response elements (REs) in many genes can also provide for rap...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Resnick MA,Inga A

更新日期：2003-08-19 00:00:00

abstract：:Neutron diffraction maps have been used to assign the rotor conformations of the hydroxyl hydrogens in trypsin. Knowledge of these conformations is used to assess the relative importance of steric and electrostatic effects in conferring the H-bonding geometries of these groups. A general finding was that most hydroxyl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kossiakoff AA,Shpungin J,Sintchak MD

更新日期：1990-06-01 00:00:00