Kinetics of fiber solidification.

abstract：:A convergent, highly stereoselective total synthesis of (-)-spinosyn A (1) is described. Key features of the synthesis include the transannular Diels-Alder reaction of macrocyclic pentaene 11 and the transannular Morita-Baylis-Hillman cyclization of 12 that generates tetracycle 26. The total synthesis of (-)-spinosyn ...

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

authors： Mergott DJ,Frank SA,Roush WR

更新日期：2004-08-17 00:00:00

abstract：:Bright, photostable, and nontoxic fluorescent contrast agents are critical for biological imaging. "Self-healing" dyes, in which triplet states are intramolecularly quenched, enable fluorescence imaging by increasing fluorophore brightness and longevity, while simultaneously reducing the generation of reactive oxygen ...

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

authors： Pati AK,El Bakouri O,Jockusch S,Zhou Z,Altman RB,Fitzgerald GA,Asher WB,Terry DS,Borgia A,Holsey MD,Batchelder JE,Abeywickrama C,Huddle B,Rufa D,Javitch JA,Ottosson H,Blanchard SC

更新日期：2020-09-29 00:00:00

abstract：:The complete primary structure of the purple membrane protein bacteriorhodopsin, which contains 248 amino acid residues, has been determined. Methods used for separation of the hydrophobic fragments included gel permeation and reverse-phase high-pressure liquid chromatography in organic solvents. The amino acid sequen...

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

authors： Khorana HG,Gerber GE,Herlihy WC,Gray CP,Anderegg RJ,Nihei K,Biemann K

更新日期：1979-10-01 00:00:00

abstract：:For taxonomic levels higher than species, the abundance distributions of the number of subtaxa per taxon tend to approximate power laws but often show strong deviations from such laws. Previously, these deviations were attributed to finite-time effects in a continuous-time branching process at the generic level. Inste...

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

authors： Chu J,Adami C

更新日期：1999-12-21 00:00:00

abstract：:Hereditary hemochromatosis (HH) is a common chronic human genetic disorder whose hallmark is systemic iron overload. Homozygosity for a mutation in the MHC class I heavy chain paralogue gene HFE has been found to be a primary cause of HH. However, many individuals homozygous for the defective allele of HFE do not deve...

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

authors： Sproule TJ,Jazwinska EC,Britton RS,Bacon BR,Fleming RE,Sly WS,Roopenian DC

更新日期：2001-04-24 00:00:00

abstract：:A definitive assay for microbiological and biochemical research on the biodegradation of lignin was developed using radioactive synthetic lignins specifically labeled in the side chains, aromatic rings or in the methoxyl groups. The [14C]lignins were prepared by oxidative polymerization with peroxidase and H2O2 Of spe...

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

authors： Kirk TK,Connors WJ,Bleam RD,Hackett WF,Zeikus JG

更新日期：1975-07-01 00:00:00

abstract：:The outer membrane (OM) of Gram-negative bacteria is a permeability barrier and an intrinsic antibiotic resistance factor. Lipoproteins are OM components that function in cell wall synthesis, diverse secretion systems, and antibiotic efflux pumps. Moreover, each of the essential OM machines that assemble the barrier r...

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

authors： Grabowicz M,Silhavy TJ

更新日期：2017-05-02 00:00:00

abstract：:Little is known about how genetic variation and epigenetic marks interact to shape differences in behavior. The foraging (for) gene regulates behavioral differences between the rover and sitter Drosophila melanogaster strains, but the molecular mechanisms through which it does so have remained elusive. We show that th...

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

authors： Anreiter I,Kramer JM,Sokolowski MB

更新日期：2017-11-21 00:00:00

abstract：:The mammalian form of the protozoan parasite Leishmania mexicana contains high activity of a cysteine proteinase (LmCPb) encoded on a tandem array of 19 genes (lmcpb). Homozygous null mutants for lmcpb have been produced by targeted gene disruption. All life-cycle stages of the mutant can be cultured in vitro, demonst...

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

authors： Mottram JC,Souza AE,Hutchison JE,Carter R,Frame MJ,Coombs GH

更新日期：1996-06-11 00:00:00

abstract：:The protein CopC from Pseudomonas syringae has been found capable of binding copper(I) and copper(II) at two different sites, occupied either one at a time or simultaneously. The protein, consisting of 102 amino acids, is known to bind copper(II) in a position that is now found consistent with a coordination arrangeme...

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

authors： Arnesano F,Banci L,Bertini I,Mangani S,Thompsett AR

更新日期：2003-04-01 00:00:00

abstract：:Sparse 3T3 cells, in excess serum, become quiescent in the early G(1) (or G(0)) phase of the cell cycle if the cells are cultured in low concentrations of amino acids, glucose, or phosphate ion. These quiescent cells then initiate DNA synthesis if the concentration of the limiting nutrient is increased. In normal medi...

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

authors： Holley RW,Kiernan JA

更新日期：1974-08-01 00:00:00

abstract：:Recent genome-wide association studies have revealed some genetic loci associated with serum uric acid levels and susceptibility to gout/hyperuricemia which contain potential candidates of physiologically important urate transporters. One of these novel loci is located upstream of SGK1 and SLC2A12, suggesting that var...

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

authors： Toyoda Y,Takada T,Miyata H,Matsuo H,Kassai H,Nakao K,Nakatochi M,Kawamura Y,Shimizu S,Shinomiya N,Ichida K,Hosoyamada M,Aiba A,Suzuki H

更新日期：2020-08-04 00:00:00

abstract：:The medial preoptic area has been shown to be intricately involved in many behaviors, including locomotion, sexual behavior, maternal care, and aggression. The gene encoding estrogen receptor-α (ERα) protein is expressed in preoptic area neurons, and a very dense immunoreactive field of ERα is found in the preoptic re...

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

authors： Ribeiro AC,Musatov S,Shteyler A,Simanduyev S,Arrieta-Cruz I,Ogawa S,Pfaff DW

更新日期：2012-10-02 00:00:00

abstract：:Smad proteins are key intracellular signaling effectors for the transforming growth factor-beta superfamily of peptide growth factors. Following receptor-induced activation, Smads move into the nucleus to activate transcription of a select set of target genes. The activity of Smad proteins must be tightly regulated to...

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

authors： Zhang Y,Chang C,Gehling DJ,Hemmati-Brivanlou A,Derynck R

更新日期：2001-01-30 00:00:00

abstract：:Cells are dynamical systems of biomolecular interactions that process information from their environment to mount diverse yet specific responses. A key property of many self-organized systems is that of criticality: a state of a system in which, on average, perturbations are neither dampened nor amplified, but are pro...

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

authors： Nykter M,Price ND,Aldana M,Ramsey SA,Kauffman SA,Hood LE,Yli-Harja O,Shmulevich I

更新日期：2008-02-12 00:00:00

abstract：:Interleukin-12 (IL-12) is critical for induction of protective immunity against intracellular bacterial infection. However, the mechanisms for efficient induction of IL-12 in innate response remain poorly understood. Here we report that the B type of carbonic anhydrase 6 (Car6-b, which encoded CA-VI B) is essential fo...

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

authors： Xu J,Xu X,Wang B,Ma Y,Zhang L,Xu H,Hu Y,Wu J,Cao X

更新日期：2017-08-08 00:00:00

abstract：:Rev-Erbβ is a nuclear receptor that couples circadian rhythm, metabolism, and inflammation. Heme binding to the protein modulates its function as a repressor, its stability, its ability to bind other proteins, and its activity in gas sensing. Rev-Erbβ binds Fe3+-heme more tightly than Fe2+-heme, suggesting its activit...

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

authors： Sarkar A,Carter EL,Harland JB,Speelman AL,Lehnert N,Ragsdale SW

更新日期：2021-01-19 00:00:00

abstract：:Thermotaxis by individual amoebae of Dictyostelium discoideum on a temperature gradient is described. These amoebae show positive thermotaxis at temperatures between 14 degrees C and 28 degrees C shortly (3 hr) after food depletion. Increasing time on the gradient reduces the positive thermotactic response at the lowe...

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

authors： Hong CB,Fontana DR,Poff KL

更新日期：1983-09-01 00:00:00

abstract：:Epithelial tissues mechanically deform the surrounding extracellular matrix during embryonic development, wound repair, and tumor invasion. Ex vivo measurements of such multicellular tractions within three-dimensional (3D) biomaterials could elucidate collective dissemination during disease progression and enable prec...

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

authors： Leggett SE,Patel M,Valentin TM,Gamboa L,Khoo AS,Williams EK,Franck C,Wong IY

更新日期：2020-03-17 00:00:00

abstract：:Under a stretching force, the sugar ring of polysaccharide molecules switches from the chair to the boat-like or inverted chair conformation. This conformational change can be observed by stretching single polysaccharide molecules with an atomic force microscope. In those early experiments, the molecules were stretche...

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

authors： Marszalek PE,Li H,Oberhauser AF,Fernandez JM

更新日期：2002-04-02 00:00:00

abstract：:Heterogeneity of heart failure (HF) phenotypes indicates contributions from underlying common polymorphisms. We considered polymorphisms in the beta(1)-adrenergic receptor (beta(1)AR), a beta-blocker target, as candidate pharmacogenomic loci. Transfected cells, genotyped human nonfailing and failing ventricles, and a ...

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

authors： Liggett SB,Mialet-Perez J,Thaneemit-Chen S,Weber SA,Greene SM,Hodne D,Nelson B,Morrison J,Domanski MJ,Wagoner LE,Abraham WT,Anderson JL,Carlquist JF,Krause-Steinrauf HJ,Lazzeroni LC,Port JD,Lavori PW,Bristow MR

更新日期：2006-07-25 00:00:00

abstract：:Axonal degeneration is an initial key step in traumatic and neurodegenerative CNS disorders. We established a unique in vivo epifluorescence imaging paradigm to characterize very early events in axonal degeneration in the rat optic nerve. Single retinal ganglion cell axons were visualized by AAV-mediated expression of...

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

authors： Knöferle J,Koch JC,Ostendorf T,Michel U,Planchamp V,Vutova P,Tönges L,Stadelmann C,Brück W,Bähr M,Lingor P

更新日期：2010-03-30 00:00:00

abstract：:Hox genes are conserved transcription factor-encoding genes that specify the identity of body regions in bilaterally symmetrical animals. In the cricket Gryllus bimaculatus, a member of the hemimetabolous insect group Orthoptera, the induction of a subset of mesodermal cells to form the primordial germ cells (PGCs) is...

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

authors： Barnett AA,Nakamura T,Extavour CG

更新日期：2019-08-13 00:00:00

abstract：:A short, highly stereoselective (over 97%) synthesis of all-trans squalene is described. Starting with succinaldehyde, a tetraenedichlorodione having the complete squalene skeleton with the four internal trans olefinic bonds has been developed in four steps involving a sequence of two double Claisen rearrangements. Th...

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

authors： Werthemann L,Johnson WS

更新日期：1970-11-01 00:00:00

abstract：:Criegee intermediates are thought to play a role in atmospheric chemistry, in particular, the oxidation of SO2, which produces SO3 and subsequently H2SO4, an important constituent of aerosols and acid rain. However, the impact of such oxidation reactions is affected by the reactions of Criegee intermediates with water...

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

authors： Huang HL,Chao W,Lin JJ

更新日期：2015-09-01 00:00:00

abstract：:Cytochromes P450 play key roles in drug metabolism and disease by oxidizing a wide variety of natural and xenobiotic compounds. High-resolution crystal structures of P450cam bound to ruthenium sensitizer-linked substrates reveal an open conformation of the enzyme that allows substrates to access the active center via ...

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

authors： Dunn AR,Dmochowski IJ,Bilwes AM,Gray HB,Crane BR

更新日期：2001-10-23 00:00:00

abstract：:Secondary (i.e., heterotrophic or animal) production is a main pathway of energy flow through an ecosystem as it makes energy available to consumers, including humans. Its estimation can play a valuable role in the examination of linkages between ecosystem functions and services. We found that oil and gas platforms of...

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

authors： Claisse JT,Pondella DJ 2nd,Love M,Zahn LA,Williams CM,Williams JP,Bull AS

更新日期：2014-10-28 00:00:00

abstract：:Immunoprecipitation of proteins extracted from metabolically labeled human glioblastoma and fibrosarcoma cells with antiserum to platelet-derived growth factor (PDGF) showed that these cells express and secrete proteins that are recognized specifically by the antiserum. The molecular masses of immunoprecipitated prote...

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

authors： Pantazis P,Pelicci PG,Dalla-Favera R,Antoniades HN

更新日期：1985-04-01 00:00:00

abstract：:In characterizing mice with targeted disruption of the SerpinB2 gene, we observed animals that were small at birth with delayed growth and decreased life expectancy. Although this phenotype cosegregated with homozygosity for the inactive SerpinB2 allele, analysis of homozygous SerpinB2-deficient mice derived from two ...

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

authors： Westrick RJ,Mohlke KL,Korepta LM,Yang AY,Zhu G,Manning SL,Winn ME,Dougherty KM,Ginsburg D

更新日期：2010-09-28 00:00:00

abstract：:Aberrant promoter hypermethylation is frequently observed in cancer. The potential for this mechanism to contribute to tumor development depends on whether the genes affected are repressed because of their methylation. Many aberrantly methylated genes play important roles in development and are bivalently marked in ES...

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

authors： Sproul D,Nestor C,Culley J,Dickson JH,Dixon JM,Harrison DJ,Meehan RR,Sims AH,Ramsahoye BH

更新日期：2011-03-15 00:00:00