Conformation of acetylcholine bound to the nicotinic acetylcholine receptor.

abstract：:Current evidence favors the theory that, when the globular motor domain of myosin attaches to actin, the light chain binding domain or "lever arm" rotates, and thereby generates movement of actin filaments. Myosin is uniquely designed for such a role in that a long alpha-helix (approximately 9 nm) extending from the C...

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

authors： Sherwood JJ,Waller GS,Warshaw DM,Lowey S

更新日期：2004-07-27 00:00:00

abstract：:Scientific and engineering innovation is vital for American competitiveness, quality of life, and national security. However, too few American students, especially women, pursue these fields. Although this problem has attracted enormous attention, rigorously tested interventions outside artificial laboratory settings ...

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

authors： Dennehy TC,Dasgupta N

更新日期：2017-06-06 00:00:00

abstract：:There is pronounced seasonal plasticity in the morphology of the neural circuits that regulate song behavior in adult songbirds, primarily in response to changes in plasma testosterone (T) levels. Most song nuclei have androgen receptors. Afferent input from the telencephalic nucleus HVc (also known as the "high vocal...

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

authors： Brenowitz EA,Lent K

更新日期：2002-09-17 00:00:00

abstract：:Aminoacyl-tRNAs are generally formed by direct attachment of an amino acid to tRNAs by aminoacyl-tRNA synthetases, but Gln-tRNA is an exception to this rule. Gln-tRNA(Gln) is formed by this direct pathway in the eukaryotic cytosol and in protists or fungi mitochondria but is formed by an indirect transamidation pathwa...

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

authors： Pujol C,Bailly M,Kern D,Maréchal-Drouard L,Becker H,Duchêne AM

更新日期：2008-04-29 00:00:00

abstract：:The matrix-2 (M2) protein from influenza A virus is a tetrameric, integral transmembrane (TM) protein that plays a vital role in viral replication by proton flux into the virus. The His37 tetrad is a pH sensor in the center of the M2 TM helix that activates the channel in response to the low endosomal pH. M2 consists ...

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

authors： Torabifard H,Panahi A,Brooks CL 3rd

更新日期：2020-02-18 00:00:00

abstract：:Release of formylmethionine from the reticulocyte ribosomal substrate, f[(3)H]Met-tRNA.ribosome, is promoted by reticulocyte release factor (RF). The initial rate of this reaction is stimulated by GTP but inhibited by GDPCP. Formation of an RF.UA[(3)H]A(2).ribosome complex is a measure of the binding of reticulocyte R...

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

authors： Tate WP,Beaudet AL,Caskey CT

更新日期：1973-08-01 00:00:00

abstract：:Discrete growing spiral modes are calculated, on the basis of principles of stellar dynamics, according to the recently developed asymptotic theory of density waves for spiral structure in galaxies. From the growth rates obtained, it appears likely that several spiral modes coexist in a given disk galaxy. General prop...

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

authors： Bertin G,Lau YY,Lin CC,Mark JW,Sugiyama L

更新日期：1977-11-01 00:00:00

abstract：:FtsEX is a bacterial ABC transporter that regulates the activity of periplasmic peptidoglycan amidases via its interaction with the murein hydrolase activator, EnvC. In Escherichia coli, FtsEX is required to separate daughter cells after cell division and for viability in low-osmolarity media. Both the ATPase activity...

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

authors： Cook J,Baverstock TC,McAndrew MBL,Stansfeld PJ,Roper DI,Crow A

更新日期：2020-11-10 00:00:00

abstract：:Human IL-10 (hIL-10) modulates critical immune and inflammatory responses by way of interactions with its high- (IL-10R1) and low-affinity (IL-10R2) cell surface receptors. Human cytomegalovirus exploits the IL-10 signaling pathway by expressing a functional viral IL-10 homolog (cmvIL-10), which shares only 27% sequen...

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

authors： Jones BC,Logsdon NJ,Josephson K,Cook J,Barry PA,Walter MR

更新日期：2002-07-09 00:00:00

abstract：:The orphan nuclear receptor Nur77/N10 has recently been demonstrated to be involved in apoptosis of T cell hybridomas. We report here that chronic expression of Nur77/N10 in thymocytes of transgenic mice results in a dramatic reduction of CD4+CD8+ double-positive as well as CD4+CD8- and CD4-CD8+ single-positive cell p...

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

authors： Weih F,Ryseck RP,Chen L,Bravo R

更新日期：1996-05-28 00:00:00

abstract：:Two strains that overproduce endonuclease III were found in a colony bank containing hybrid ColE1-Escherichia coli plasmids. The enzyme was identified in crude extracts by the degradation of partially depyrimidinated DNA in the presence of EDTA, by its sedimentation velocity, and by its associated thymine glycol-DNA g...

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

authors： Cunningham RP,Weiss B

更新日期：1985-01-01 00:00:00

abstract：:In light of the rapid recent retreat of Arctic sea ice, a number of studies have discussed the possibility of a critical threshold (or "tipping point") beyond which the ice-albedo feedback causes the ice cover to melt away in an irreversible process. The focus has typically been centered on the annual minimum (Septemb...

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

authors： Eisenman I,Wettlaufer JS

更新日期：2009-01-06 00:00:00

abstract：:The amount of information that can be stored in working memory is limited but may be improved with practice. The basis of improved efficiency at the level of neural activity is unknown. To investigate this question, we trained monkeys to perform a working memory task that required memory for multiple stimuli. Performa...

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

authors： Tang H,Qi XL,Riley MR,Constantinidis C

更新日期：2019-04-02 00:00:00

abstract：:The Alzheimer A beta amyloid peptide (A beta) is the principal proteinaceous component of amyloid associated with Alzheimer disease (AD). We have determined the relative abundance of A beta structural variants present in amyloid from brains of 10 individuals with sporadic AD, 2 individuals with familial AD carrying sp...

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

authors： Näslund J,Schierhorn A,Hellman U,Lannfelt L,Roses AD,Tjernberg LO,Silberring J,Gandy SE,Winblad B,Greengard P

更新日期：1994-08-30 00:00:00

abstract：:Numerous relatively short regions within intrinsically disordered proteins (IDPs) serve as molecular recognition elements (MoREs). They fold into ordered structures upon binding to their partner molecules. Currently, there is still a lack of in-depth understanding of how coupled binding and folding occurs in MoREs. He...

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

authors： Wang Y,Chu X,Longhi S,Roche P,Han W,Wang E,Wang J

更新日期：2013-10-01 00:00:00

abstract：:Soon after the initiation of sporulation, Bacillus subtilis divides asymmetrically to produce sister cells that have very different developmental fates. Recently, it has been proposed that the differential gene expression which begins soon after this division is due to cell-specific activation of the transcription fac...

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

authors： Lewis PJ,Partridge SR,Errington J

更新日期：1994-04-26 00:00:00

abstract：:Cold-water conditions have excluded durophagous (skeleton-breaking) predators from the Antarctic seafloor for millions of years. Rapidly warming seas off the western Antarctic Peninsula could now facilitate their return to the continental shelf, with profound consequences for the endemic fauna. Among the likely first ...

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

authors： Aronson RB,Smith KE,Vos SC,McClintock JB,Amsler MO,Moksnes PO,Ellis DS,Kaeli J,Singh H,Bailey JW,Schiferl JC,van Woesik R,Martin MA,Steffel BV,Deal ME,Lazarus SM,Havenhand JN,Swalethorp R,Kjellerup S,Thatje S

更新日期：2015-10-20 00:00:00

abstract：:Modern practice for training classification deepnets involves a terminal phase of training (TPT), which begins at the epoch where training error first vanishes. During TPT, the training error stays effectively zero, while training loss is pushed toward zero. Direct measurements of TPT, for three prototypical deepnet a...

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

authors： Papyan V,Han XY,Donoho DL

更新日期：2020-10-06 00:00:00

abstract：:T cell activation and tolerance are regulated by costimulatory molecules. Although PD-1 serves as a crucial negative regulator of T cells, the function of its ligands, PDL1 and PDL2, is still controversial. In this study, we created a PDL2-deficient mouse to characterize its function in T cell activation and tolerance...

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

authors： Zhang Y,Chung Y,Bishop C,Daugherty B,Chute H,Holst P,Kurahara C,Lott F,Sun N,Welcher AA,Dong C

更新日期：2006-08-01 00:00:00

abstract：:In the presence of N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-Ala as donor, and either D-[(14)C]alanine, [(14)C]-glycine, or meso-[(3)H]diaminopimelic acid as acceptor, the DD carboxypeptidases from Streptomyces R61 and R39 catalyze a transpeptidation reaction with the release of terminal D-alanine from the donor and ...

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

authors： Pollock JJ,Ghuysen JM,Linder R,Salton MR,Perkins HR,Nieto M,Leyh-Bouille M,Frere JM,Johnson K

更新日期：1972-03-01 00:00:00

abstract：:Normal rat kidney cells were nonproductively infected either with CP27, a mutant of Moloney sarcoma virus that is temperature-sensitive for maintenance of transformation, or with the parental wild-type virus. The nonproducer cells were inoculated into the tails of athymic nude mice that were subsequently incubated at ...

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

authors： Klarlund JK,Forchhammer J

更新日期：1980-03-01 00:00:00

abstract：:Protein misfolding and aggregation cause serious degenerative conditions such as Alzheimer's, Parkinson, and prion diseases. Damage to membranes is thought to be one of the mechanisms underlying cellular toxicity of a range of amyloid assemblies. Previous studies have indicated that amyloid fibrils can cause membrane ...

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

authors： Milanesi L,Sheynis T,Xue WF,Orlova EV,Hellewell AL,Jelinek R,Hewitt EW,Radford SE,Saibil HR

更新日期：2012-12-11 00:00:00

abstract：:Charcot-Marie-Tooth disease type 4C (CMT4C) is an early-onset, autosomal recessive form of demyelinating neuropathy. The clinical manifestations include progressive scoliosis, delayed age of walking, muscular atrophy, distal weakness, and reduced nerve conduction velocity. The gene mutated in CMT4C disease, SH3TC2/KIA...

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

authors： Arnaud E,Zenker J,de Preux Charles AS,Stendel C,Roos A,Médard JJ,Tricaud N,Kleine H,Luscher B,Weis J,Suter U,Senderek J,Chrast R

更新日期：2009-10-13 00:00:00

abstract：:In the presence of the S polypeptide, maize chloroplast DNA-dependent RNA polymerase preferentially transcribes sequences within the 2200-nucleotide-pair-long maize chloroplast chromosome fragment Eco [unk] from a supercoiled chimeric plasmid cloned in Escherichia coli [Jolly, S. O. & Bogorad, L. (1980) Proc. Natl. Ac...

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

authors： Schwarz Z,Jolly SO,Steinmetz AA,Bogorad L

更新日期：1981-06-01 00:00:00

abstract：:Photoperiodic control of testis growth in Passer domesticus (house sparrow) is mediated entirely by extraretinal photoreceptors in the brain. The eyes do not participate in photoperiodically significant photoreception. Removal of the pineal organ does not affect either the response to light or, to a first approximatio...

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

authors： Menaker M,Roberts R,Elliott J,Underwood H

更新日期：1970-09-01 00:00:00

abstract：:In all organisms, mild heat pretreatments induce tolerance to high temperatures. In the yeast Saccharomyces cerevisiae, such pretreatments strongly induce heat-shock protein (Hsp) 104, and hsp104 mutations greatly reduce high-temperature survival, indicating Hsp1O4 plays a critical role in induced thermotolerance. Sur...

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

authors： Lindquist S,Kim G

更新日期：1996-05-28 00:00:00

abstract：:The environmental impact of using recombinant bovine somatotropin (rbST) in dairy production was examined on an individual cow, industry-scale adoption, and overall production system basis. An average 2006 U.S. milk yield of 28.9 kg per day was used, with a daily response to rbST supplementation of 4.5 kg per cow. Rat...

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

authors： Capper JL,Castañeda-Gutiérrez E,Cady RA,Bauman DE

更新日期：2008-07-15 00:00:00

abstract：:Nanoparticle-based experimental therapeutics are currently being investigated in numerous human clinical trials. CALAA-01 is a targeted, polymer-based nanoparticle containing small interfering RNA (siRNA) and, to our knowledge, was the first RNA interference (RNAi)-based, experimental therapeutic to be administered to...

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

authors： Zuckerman JE,Gritli I,Tolcher A,Heidel JD,Lim D,Morgan R,Chmielowski B,Ribas A,Davis ME,Yen Y

更新日期：2014-08-05 00:00:00

abstract：:Elastin peptides prepared by alcoholic potassium hydroxide degradation of highly purified fibrous elastin from bovine ligamentum nuchae (kappa-elastin) were shown to act on the ion channels of human monocytes, aorta smooth muscle cells, and skin fibroblasts. In small amounts (between 0.1 and 1 microgram/ml), elastin p...

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

authors： Jacob MP,Fülöp T Jr,Foris G,Robert L

更新日期：1987-02-01 00:00:00

abstract：:A residual sphere is formed by projecting seismic ray travel-time anomalies, relative to a reference Earth model, onto an imaginary sphere around an earthquake. Any dominant slab-like fast band can be determined with spherical harmonic expansion. The technique is useful in detecting trends associated with high-velocit...

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

authors： Zhou HW,Anderson DL

更新日期：1989-11-01 00:00:00