Dynamics of self assembly of magnetized disks rotating at the liquid-air interface.

abstract：:Using a tissue culture system based on a nearly pure population of avian precartilage mesenchymal cells, we have found that ambient glucose levels as little as 50% lower, or 100% higher, than normally present in embryonic sera are deleterious to cartilage development, as measured by the accumulation of highly sulfated...

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

authors： Leonard CM,Bergman M,Frenz DA,Macreery LA,Newman SA

更新日期：1989-12-01 00:00:00

abstract：:Fermions need to satisfy the Pauli exclusion principle: no two can be in the same state. This restriction is most compactly expressed in a second quantization formalism by the requirement that the creation and annihilation operators of the electrons satisfy anticommutation relations. The usual classical limit of quant...

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

authors： Levine RD

更新日期：2000-02-29 00:00:00

abstract：:In the cell, proteins are synthesized from N to C terminus and begin to fold during translation. Cotranslational folding mechanisms are therefore linked to elongation rate, which varies as a function of synonymous codon usage. However, synonymous codon substitutions can affect many distinct cellular processes, which h...

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

authors： Walsh IM,Bowman MA,Soto Santarriaga IF,Rodriguez A,Clark PL

更新日期：2020-02-18 00:00:00

abstract：:An unusual system of genetic exchange exists in the purple nonsulfur bacterium Rhodobacter capsulatus. DNA transmission is mediated by a small bacteriophage-like particle called the gene transfer agent (GTA) that transfers random 4.5-kb segments of the producing cell's genome to recipient cells, where allelic replacem...

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

authors： Lang AS,Beatty JT

更新日期：2000-01-18 00:00:00

abstract：:Thresholds are frequently thought to be involved in the development of discrete structures in response to a shallow, monotonic gradient of morphogenetic information. We propose a mechanism for threshold setting that incorporates two essential components: (i) determinator genes that produce intracellular "determinators...

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

authors： McCarrey JR,Riggs AD

更新日期：1986-02-01 00:00:00

abstract：:Agrobacterium tumefaciens is the causal agent of crown gall disease. The bacterium is capable of transferring a segment of single-stranded DNA (ssDNA) into recipient cells during the transformation process, and it has been widely used as a genetic modification tool for plants and nonplant organisms. Transferred DNA (T...

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

authors： Li X,Yang Q,Peng L,Tu H,Lee LY,Gelvin SB,Pan SQ

更新日期：2020-10-20 00:00:00

abstract：:Scanning confocal fluorescence microscopy and multiphoton fluorescence microscopy were used to image the uptake of the protein lysozyme into individual ion exchange chromatography particles in a packed bed in real time. Self-sharpening concentration fronts penetrating into the particles were observed at low salt conce...

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

authors： Dziennik SR,Belcher EB,Barker GA,DeBergalis MJ,Fernandez SE,Lenhoff AM

更新日期：2003-01-21 00:00:00

abstract：:Purified RNA polymerase II (pol II) from the yeast Saccharomyces cerevisiae pauses without releasing at many locations during in vitro transcription. Pausing can be induced by intrinsic DNA sequence as well as by specific DNA bound proteins such as the RNA pol I termination factor, Reb1p, or lac repressor. Addition of...

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

authors： Lang WH,Platt T,Reeder RH

更新日期：1998-04-28 00:00:00

abstract：:A polar lipid containing about 20 per cent of the lipid soluble inositol has been purified from cells of Saccharomyces cerevisiae. This compound labeled with (3)H-inositol, (32)P(i), or (14)C glucose was isolated from aqueous pyridine extracts by means of paper chromatography. Unlabeled compound was obtained by a diff...

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

authors： Steiner S,Smith S,Waechter CJ,Lester RL

更新日期：1969-11-01 00:00:00

abstract：:Pyochelin, an endogenous growth promoter that solubilizes ferric iron, has been isolated from Pseudomonas aeruginosa, including clinical strains. The structure of pyochelin has been assigned as 2-(2-o-hydroxyphenyl-2-thiazolin-4-yl)-3-methylthiazolidine-4-carboxylic acid and is of a different type from those previousl...

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

authors： Cox CD,Rinehart KL Jr,Moore ML,Cook JC Jr

更新日期：1981-07-01 00:00:00

abstract：:The triphenylmethane derivative aurintricarboxylic acid (ATA), but not aurin, selectively prevented the binding of OKT4A/Leu-3a monoclonal antibody (mAb) and, to a lesser extent, OKT4 mAb to the CD4 cell receptor for human immunodeficiency virus type 1 (HIV-1). The effect was seen within 1 min at an ATA concentration ...

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

authors： Schols D,Baba M,Pauwels R,Desmyter J,De Clercq E

更新日期：1989-05-01 00:00:00

abstract：:Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathogenesis of obesity-driven type 2 diabetes mellitus and associated cardiovascular complications. Here, we show that perturbation of caveolar microdomains leads to insulin resistance and concomitant up-regulation of PAI-1 in 3T3L1 adipocytes. ...

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

authors： Venugopal J,Hanashiro K,Yang ZZ,Nagamine Y

更新日期：2004-12-07 00:00:00

abstract：:The roles of glycosylation and protein synthesis in the maintenance of insulin receptor levels and turnover rates in 3T3-L1 adipocytes were investigated. The heavy isotope density-shift technique was employed to determine the effects of inhibitors of these processes on the rates of synthesis and degradation of cellula...

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

authors： Reed BC,Ronnett GV,Lane MD

更新日期：1981-05-01 00:00:00

abstract：:We provide evidence for an interaction between mouse class I major histocompatibility complex antigens and insulin receptors. Antibodies against class I but not class II major histocompatibility complex antigens immunoprecipitate photoaffinity-labeled hepatic insulin receptors. Haplotype specificity is demonstrated by...

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

authors： Phillips ML,Moule ML,Delovitch TL,Yip CC

更新日期：1986-05-01 00:00:00

abstract：:Under anesthesia with sodium pentobarbital, the sciatic nerves of rats were transected bilaterally, and a catheter was inserted into the central end of the left renal artery. After an initial flush, an Alzet pump was attached to the catheter, containing various concentrations of glycyl-L-glutamine (Gly-Gln), methylpre...

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

authors： Koelle GB,Han MS

更新日期：1990-12-01 00:00:00

abstract：:Biodistribution studies of a water-soluble radioactive metallofullerene compound have been conducted using BALB/c mice. To this end, a sample containing Hox@C82 (x = 1, 2) was purified and derivatized to prepare the water-soluble metallofullerol, Hox@C82(OH)y. This metallofullerol was then neutron-activated (165Ho[n,g...

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

authors： Cagle DW,Kennel SJ,Mirzadeh S,Alford JM,Wilson LJ

更新日期：1999-04-27 00:00:00

abstract：:n-Type Si electrodes in MeOH solvent with 0.2 M (1-hydroxyethyl)ferrocene, 0.5 mM (1-hydroxyethyl)ferricenium, and 1.0 M LiClO(4) exhibit air mass 2 conversion efficiencies of 10.1% for optical energy into electricity. We observe open-circuit voltages of 0.53 V and short-circuit quantum efficiencies for electron flow ...

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

authors： Gronet CM,Lewis NS,Cogan G,Gibbons J

更新日期：1983-02-01 00:00:00

abstract：:Although neurotrophins are primarily associated with long-term effects on neuronal survival and differentiation, recent studies have shown that acute changes in synaptic transmission can also be produced. In the hippocampus, an area critically involved in learning and memory, we have found that brain-derived neurotrop...

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

authors： Levine ES,Dreyfus CF,Black IB,Plummer MR

更新日期：1995-08-15 00:00:00

abstract：:We introduce a model of evolution in which competing organisms are represented by percolation lattice models. Fitness is based on the number of occupied sites remaining after removing a cluster connected to a randomly selected site. High-fitness individuals arising through mutation and selection must trade off density...

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

authors： Zhou T,Carlson JM,Doyle J

更新日期：2002-02-19 00:00:00

abstract：:B-1a cells reside in both the peritoneal cavity and the spleen. LPS stimulates splenic B-1a to differentiate to plasma cells producing natural IgM specific for microbial and self antigens. However, there are conflicting views as to whether the B-1a cells divide before this differentiation occurs, and hence how the res...

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

authors： Yang Y,Tung JW,Ghosn EE,Herzenberg LA,Herzenberg LA

更新日期：2007-03-13 00:00:00

abstract：:The ATP-dependent enzyme dethiobiotin synthetase from Escherichia coli catalyses the formation of dethiobiotin from CO2 and 7, 8-diaminopelargonic acid. The reaction is initiated by the formation of a carbamate and proceeds through a phosphorylated intermediate, a mixed carbamic phosphoric anhydride. Here, we report t...

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

authors： Käck H,Gibson KJ,Lindqvist Y,Schneider G

更新日期：1998-05-12 00:00:00

abstract：:We have attempted to model human metastatic disease by implanting human target organs into the immunodeficient C.B-17 scid/scid (severe combined immunodeficiency; SCID) mouse, creating SCID-hu mice. Preferential metastasis to implants of human fetal lung and human fetal bone marrow occurred after i.v. injection of hum...

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

authors： Shtivelman E,Namikawa R

更新日期：1995-05-09 00:00:00

abstract：:A computer code to investigate the equilibrium and stability of a diffuse plasma in three dimensions is described that generalizes earlier work on a sharp free boundary model. Toroidal equilibria of a plasma are determined by considering paths of steepest descent associated with a new version of the variational princi...

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

authors： Betancourt O,Garabedian P

更新日期：1976-04-01 00:00:00

abstract：:ERK6, a mitogen-activated protein (MAP) kinase-related serine/threonine kinase, is highly expressed in human skeletal muscle and appears to function as a signal transducer during differentiation of myoblasts to myotubes. In transfected 293 cells, activation of the 45-kDa enzyme results in tyrosine-phosphorylated 46- a...

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

authors： Lechner C,Zahalka MA,Giot JF,Møller NP,Ullrich A

更新日期：1996-04-30 00:00:00

abstract：:Existing moral psychology research commonly explains certain phenomena in terms of a motivation to blame. However, this motivation is not measured directly, but rather is inferred from other measures, such as participants' judgments of an agent's blameworthiness. The present paper introduces new methods for assessing ...

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

authors： Ames DL,Fiske ST

更新日期：2015-03-24 00:00:00

abstract：:Photoreceptors of the Xenopus laevis retina are the site of a circadian clock. As part of a differential display screen for rhythmic gene products in this system, we have identified a photoreceptor-specific mRNA expressed in peak abundance at night. cDNA cloning revealed an open reading frame encoding a putative 388 a...

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

authors： Green CB,Besharse JC

更新日期：1996-12-10 00:00:00

abstract：:The understanding of mechanisms controlling zinc absorption and metabolism at the molecular level has advanced recently. Kinetics of zinc transport have been investigated for many years, but only recently have genes coding for proteins thought to be involved in the transport process been cloned. Four putative zinc tra...

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

authors： McMahon RJ,Cousins RJ

更新日期：1998-04-28 00:00:00

abstract：:DNA synthesized in vitro from a phage M13 template has been cleaved at either guanine, adenine, or cytosine residues by ribosubstitution techniques. Fingerprints of the fragments obtained suggest that DNA sequencing will be possible with this technique. ...

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

authors： Salser W,Fry K,Brunk C,Poon R

更新日期：1972-01-01 00:00:00

abstract：:For study of the basis of an X-linked form of gout in man, several clonal lines deficient in hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) were selected from the human lymphoblast line WI-L2 by spontaneous and mutagen-induced resistance to 10 muM 8-azaguanine. Three groups could be defined: (1) clones wi...

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

authors： Lever JE,Nuki G,Seegmiller JE

更新日期：1974-07-01 00:00:00

abstract：:Membrane-integrated type II phosphatidic acid phosphatases (PAP2s) are important for numerous bacterial to human biological processes, including glucose transport, lipid metabolism, and signaling. Escherichia coli phosphatidylglycerol-phosphate phosphatase B (ecPgpB) catalyzes removing the terminal phosphate group fro...

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

authors： Fan J,Jiang D,Zhao Y,Liu J,Zhang XC

更新日期：2014-05-27 00:00:00