Agricultural origins on the Anatolian plateau.

abstract：:Glycosyl phosphates are shown to be activated to stereospecific nucleophilic substitution reactions by precisely tailored bis-thiourea catalysts. Enhanced reactivity and scope is observed with phosphate relative to chloride leaving groups. Stronger binding (Km) to the H-bond donor and enhanced reactivity of the comple...

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

authors： Levi SM,Li Q,Rötheli AR,Jacobsen EN

更新日期：2019-01-02 00:00:00

abstract：:In the United States, the iconic groundfish fishery for Gulf of Maine cod has endured several dramatic reductions in annual catch limits and been federally declared an economic disaster. Using a repeated cross-sectional survey of fishing captains to assess potential social impacts of the fishery failure, we found that...

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

authors： Scyphers SB,Picou JS,Grabowski JH

更新日期：2019-11-12 00:00:00

abstract：:The role of cell surface immunoglobulin in helper T-cell-dependent B-cell activation was analyzed using a B-cell lymphoma, CH12, with known antigen specificity and activation properties similar to those of a resting B cell. Two sources of helper T cells were used, both selected such that they interact with H-2-encoded...

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

authors： LoCascio NJ,Haughton G,Arnold LW,Corley RB

更新日期：1984-04-01 00:00:00

abstract：:In the search for selective and long-acting analogs of somatostatin, nearly 200 compounds were synthesized by solid-phase methods, purified, and tested biologically. Among these octapeptides, some contained N-terminal (Formula: see text) were 177 times and 113 times more potent, respectively, than somatostatin in test...

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

authors： Cai RZ,Szoke B,Lu R,Fu D,Redding TW,Schally AV

更新日期：1986-03-01 00:00:00

abstract：:A method for assessing genomic similarity based on relative abundances of short oligonucleotides in large DNA samples is introduced. The method requires neither homologous sequences nor prior sequence alignments. The analysis centers on (i) dinucleotide (and tri- and tetra-) relative abundance extremes in genomic sequ...

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

authors： Karlin S,Ladunga I

更新日期：1994-12-20 00:00:00

abstract：:Cyclodextrins are cyclic oligosaccharides widely used in the pharmaceutical industry to improve drug delivery and to increase the solubility of hydrophobic compounds. Anabaenolysins are lipopeptides produced by cyanobacteria with potent lytic activity in cholesterol-containing membranes. Here, we identified the 23- to...

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

authors： Shishido TK,Jokela J,Kolehmainen CT,Fewer DP,Wahlsten M,Wang H,Rouhiainen L,Rizzi E,De Bellis G,Permi P,Sivonen K

更新日期：2015-11-03 00:00:00

abstract：:In classical knot theory and the theory of quantum invariants substantial effort was directed toward the search for unknotting moves on links. We solve, in this article, several classical problems concerning unknotting moves. Our approach uses a concept, Burnside groups of links, that establishes an unexpected relatio...

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

authors： Dabkowski MK,Przytycki JH

更新日期：2004-12-14 00:00:00

abstract：:Duplication of genomic segments provides a primary resource for the origin of evolutionary novelties. However, most previous studies have focused on duplications of complete protein-coding genes, whereas little is known about the significance of duplication segments that are entirely internal to genes. Our examination...

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

authors： Gao X,Lynch M

更新日期：2009-12-08 00:00:00

abstract：:Athymic mice grafted at birth with allogeneic thymic epithelium (TE) from day 10 embryos before hematopoietic cell colonization reconstitute normal numbers of T cells and exhibit full life-long tolerance to skin grafts of the TE haplotype. Intravenous transfers of splenic cells, from these animals to adult syngeneic a...

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

authors： Modigliani Y,Thomas-Vaslin V,Bandeira A,Coltey M,Le Douarin NM,Coutinho A,Salaün J

更新日期：1995-08-01 00:00:00

abstract：:Human embryonic stem cells have the potential to differentiate into various cell types and, thus, may be useful as a source of cells for transplantation or tissue engineering. We describe here the differentiation steps of human embryonic stem cells into endothelial cells forming vascular-like structures. The human emb...

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

authors： Levenberg S,Golub JS,Amit M,Itskovitz-Eldor J,Langer R

更新日期：2002-04-02 00:00:00

abstract：:Diphtheria toxin ( DTx ) is an extremely potent inhibitor of protein synthesis. It is secreted as a linear polypeptide, which is cleaved to produce disulfide-linked A and B fragments. Fragment A, the inhibitor of protein synthesis, requires fragment B, the recognition subunit, for entry into intact cells. Fragment B h...

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

authors： Zalman LS,Wisnieski BJ

更新日期：1984-06-01 00:00:00

abstract：:The possibility that glycolate oxidation in unicellular green algae is linked to mitochondrial electron transport, rather than to peroxisomal metabolism as in higher plants and animals, was studied in a mutant of Chlamydomonas reinhardtii (dk97) deficient in cytochrome oxidase. This mutant had normal rates of dark res...

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

authors： Husic DW,Tolbert NE

更新日期：1987-03-01 00:00:00

abstract：:Dual-color fluorescence cross-correlation spectroscopy (dual-color FCS) has previously been shown to be a suitable tool not only for binding but also for catalytic rate studies. In this work, its application as a rapid method for high-throughput screening (HTS) and evolutionary biotechnology is described. This applica...

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

authors： Koltermann A,Kettling U,Bieschke J,Winkler T,Eigen M

更新日期：1998-02-17 00:00:00

abstract：:Sonic hedgehog (Shh) plays an integral role in both the anterior-posterior (A-P) patterning and expansion of developing vertebrate limbs through a feedback loop involving Fgfs, Bmps, and Gremlin. In bat limbs A-P patterning and the size of the digital field are unique. The posterior digits of the forelimb are elongate...

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

authors： Hockman D,Cretekos CJ,Mason MK,Behringer RR,Jacobs DS,Illing N

更新日期：2008-11-04 00:00:00

abstract：:The role of anti-peripheral nerve myelin antibody (anti-PNM Ab) in the pathogenesis of acquired demyelination of peripheral nerve is unclear, in part, due to the poor correlation between antibody and disease activity. Previous studies show that only 27-50% of patients with acute demyelinating neuropathy or Guillain-Ba...

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

authors： Koski CL,Humphrey R,Shin ML

更新日期：1985-02-01 00:00:00

abstract：:Tryptophan biosynthesis is subject to exquisite control in species of Bacillus and has become one of the best-studied model systems in gene regulation. The protein TRAP (trp RNA-binding attenuation protein) predominantly forms a ring-shaped 11-mer, which binds cognate RNA in the presence of tryptophan to suppress expr...

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

authors： Watanabe M,Heddle JG,Kikuchi K,Unzai S,Akashi S,Park SY,Tame JR

更新日期：2009-02-17 00:00:00

abstract：:The effect of alpha-latrotoxin from black widow spider venom upon guinea pig cerebral cortical synaptosomes is described. Plasma membrane potential (delta psi p), in situ mitochondrial membrane potential (delta psi m), Ca2+ transport, gamma-amino[3H]butyrate release, [3H]noradrenaline release, and synaptosomal ATP wer...

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

authors： Nicholls DG,Rugolo M,Scott IG,Meldolesi J

更新日期：1982-12-01 00:00:00

abstract：:Recent advances in high-field MRI have dramatically improved the visualization of human brain anatomy in vivo. Most notably, in cortical gray matter, strong contrast variations have been observed that appear to reflect the local laminar architecture. This contrast has been attributed to subtle variations in the magnet...

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

authors： Fukunaga M,Li TQ,van Gelderen P,de Zwart JA,Shmueli K,Yao B,Lee J,Maric D,Aronova MA,Zhang G,Leapman RD,Schenck JF,Merkle H,Duyn JH

更新日期：2010-02-23 00:00:00

abstract：:Alzheimer's disease is characterized by two primary pathological features: amyloid plaques and neurofibrillary tangles. The interconnection between amyloid and tau aggregates is of intense interest, but mouse models have yet to reveal a direct interrelationship. We now show that NO may be a key factor that connects am...

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

authors： Colton CA,Vitek MP,Wink DA,Xu Q,Cantillana V,Previti ML,Van Nostrand WE,Weinberg JB,Dawson H

更新日期：2006-08-22 00:00:00

abstract：:Vibrio cholerae is both an inhabitant of estuarine environments and the etiologic agent of the diarrheal disease cholera. Previous work has demonstrated that V. cholerae forms both an exopolysaccharide-dependent biofilm and a Ca2+-dependent biofilm. In this work, we demonstrate a role for the O-antigen polysaccharide ...

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

authors： Kierek K,Watnick PI

更新日期：2003-11-25 00:00:00

abstract：:During the development of a macronucleus from a micronucleus after cell mating in hypotrichs all the genes (approximately 20,000) are excised from micronuclear chromosomes as individual small DNA molecules. Telomeres are added to the ends of each gene-sized molecule and each is amplified, mostly by approximately 1000-...

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

authors： Greslin AF,Prescott DM,Oka Y,Loukin SH,Chappell JC

更新日期：1989-08-01 00:00:00

abstract：:Although it is well described in model membranes, little is known about phase separation in biological membranes. Here, we provide evidence for a coexistence of at least two different lipid bilayer phases in the apical plasma membrane of epithelial cells. Phase connectivity was assessed by measuring long-range diffusi...

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

authors： Meder D,Moreno MJ,Verkade P,Vaz WL,Simons K

更新日期：2006-01-10 00:00:00

abstract：:The subcellular localization of Ocrl, the inositol polyphosphate 5-phosphatase that is mutated in Lowe syndrome, was investigated by fluorescence microscopy. Ocrl was localized to endosomes and Golgi membranes along with clathrin, giantin, the mannose 6-phosphate receptor, transferrin, and the early endosomal antigen ...

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

authors： Ungewickell A,Ward ME,Ungewickell E,Majerus PW

更新日期：2004-09-14 00:00:00

abstract：:Early members of the dinosaur-pterosaur clade Ornithodira are very rare in the fossil record, obscuring our understanding of the origins of this important group. Here, we describe an early ornithodiran (Kongonaphon kely gen. et sp. nov.) from the Mid-to-Upper Triassic of Madagascar that represents one of the smallest ...

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

authors： Kammerer CF,Nesbitt SJ,Flynn JJ,Ranivoharimanana L,Wyss AR

更新日期：2020-07-28 00:00:00

abstract：:A polypeptide transforming growth factor (TGF) that induces anchorage-dependent rat kidney fibroblasts to grow in soft agar has been isolated from human placenta and purified to homogeneity. This polypeptide is classified as a type beta TGF because it does not compete with epidermal growth factor (EGF) for membrane re...

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

authors： Frolik CA,Dart LL,Meyers CA,Smith DM,Sporn MB

更新日期：1983-06-01 00:00:00

abstract：:The primary structure and phosphorylation pattern of the tandem Y(1)S(2)P(3)T(4)S(5)P(6)S(7) repeats of the RNA polymerase II carboxyl-terminal domain (CTD) convey information about the transcription apparatus--a CTD code--to a large ensemble of CTD-binding receptor proteins. Four of the seven coding "letters" of the ...

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

authors： Schwer B,Sanchez AM,Shuman S

更新日期：2012-10-30 00:00:00

abstract：:IL-7 and thymic stromal lymphopoietin (TSLP) are two major cytokines controlling murine B cell development. IL-7 has been studied extensively, but only recently has it become possible to unravel the role of TSLP in detail. We studied the biological activities of TSLP in B cell development at distinct ages in the mouse...

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

authors： Vosshenrich CA,Cumano A,Müller W,Di Santo JP,Vieira P

更新日期：2004-07-27 00:00:00

abstract：:A fundamental property of ecosystems is a tradeoff between the number and size of habitats: as the number of habitats within a fixed area increases, the average area per habitat must decrease. This tradeoff is termed the "area-heterogeneity tradeoff." Theoretical models suggest that the reduction in habitat sizes unde...

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

authors： Ben-Hur E,Kadmon R

更新日期：2020-03-03 00:00:00

abstract：:Whole-cell DNA preparations isolated from SC-1 cells chronically infected with N- or B-tropic murine leukemia viruses (MuLV) were tested for infectious activity in an Fv-1n (NIH-3T3) and two Fv-Ib (C57BL/6 and SV-A31) cell cultures. Efficiency of transfection for all DNAs was better in the NIH-3T3 cells than in C57BL/...

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

authors： Hsu IC,Yang WK,Tennant RW,Brown A

更新日期：1978-03-01 00:00:00

abstract：:Protein 4.1R (4.1R) is a multifunctional component of the red cell membrane. It forms a ternary complex with actin and spectrin, which defines the nodal junctions of the membrane-skeletal network, and its attachment to the transmembrane protein glycophorin C creates a bridge between the protein network and the membran...

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

authors： Salomao M,Zhang X,Yang Y,Lee S,Hartwig JH,Chasis JA,Mohandas N,An X

更新日期：2008-06-10 00:00:00