Planar-to-tubular structural transition in boron clusters: B20 as the embryo of single-walled boron nanotubes.

abstract：:The proteolytic cleavage of sterol regulatory element-binding proteins (SREBPs) is regulated by SREBP cleavage-activating protein (SCAP), which forms complexes with SREBPs in membranes of the endoplasmic reticulum (ER). In sterol-depleted cells, SCAP facilitates cleavage of SREBPs by Site-1 protease, thereby initiatin...

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

authors： Nohturfft A,DeBose-Boyd RA,Scheek S,Goldstein JL,Brown MS

更新日期：1999-09-28 00:00:00

abstract：:Unfolded RNase A is known to contain an equilibrium mixture of two forms, a slow-folding form (U(1)) and a fast-folding form (U(2)). If U(1) is produced after unfolding by the slow cis-trans isomerization of proline residues about X-Pro imide bonds, then the formation of U(1) should be catalyzed by strong acids. There...

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

authors： Schmid FX,Baldwin RL

更新日期：1978-10-01 00:00:00

abstract：:We extend and apply theories of filled foam elasticity and failure to recently available data on foods. The predictions of elastic modulus and failure mode dependence on internal pressure and on wall integrity are borne out by photographic evidence of distortion and failure under compressive loading and under the loca...

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

authors： Warner M,Thiel BL,Donald AM

更新日期：2000-02-15 00:00:00

abstract：:Cytochrome c peroxidase reacts with peroxide to form compound I, which contains an oxyferryl heme and an indolyl radical at Trp-191. The indolyl free radical has a half-life of several hours at room temperature, and this remarkable stability is essential for the catalytic function of cytochrome c peroxidase. To probe ...

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

authors： Miller MA,Han GW,Kraut J

更新日期：1994-11-08 00:00:00

abstract：:The dominant theories of human placebo effects rely on a notion that consciously perceptible cues, such as verbal information or distinct stimuli in classical conditioning, provide signals that activate placebo effects. However, growing evidence suggest that behavior can be triggered by stimuli presented outside of co...

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

authors： Jensen KB,Kaptchuk TJ,Kirsch I,Raicek J,Lindstrom KM,Berna C,Gollub RL,Ingvar M,Kong J

更新日期：2012-09-25 00:00:00

abstract：:At the neuromuscular junction, two motor neuron-derived signals have been implicated in the regulation of synaptogenesis. Neuregulin-1 is thought to induce transcription of acetylcholine receptor (AChR) genes in subsynaptic muscle nuclei by activating ErbB receptors. Neural agrin aggregates AChRs by activating the rec...

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

authors： Moore C,Leu M,Müller U,Brenner HR

更新日期：2001-12-04 00:00:00

abstract：:This paper reviews food (especially cereal) production trends and prospects for the world and its main regions. Despite fears to the contrary, in recent years we have seen continued progress toward better methods of feeding humanity. Sub-Saharan Africa is the sole major exception. Looking to the future, this paper arg...

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

authors： Dyson T

更新日期：1999-05-25 00:00:00

abstract：:Activation of the androgen receptor (AR) may play a role in androgen-independent progression of prostate cancer. Multiple mechanisms of AR activation, including stimulation by tyrosine kinases, have been postulated. We and others have recently shown involvement of activated Cdc42-associated tyrosine kinase Ack1 in adv...

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

authors： Mahajan NP,Liu Y,Majumder S,Warren MR,Parker CE,Mohler JL,Earp HS,Whang YE

更新日期：2007-05-15 00:00:00

abstract：:We have isolated and characterized the complete human villin gene. The villin gene is located on chromosome 2q35-36 in humans and on chromosome 1 in mice. Villin belongs to a family of calcium-regulated actin-binding proteins that share structural and functional homologies. The villin gene is expressed mainly in cells...

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

authors： Pringault E,Robine S,Louvard D

更新日期：1991-12-01 00:00:00

abstract：:Pharmacological treatments designed to reactivate fetal γ-globin can lead to an effective and successful clinical outcome in patients with hemoglobinopathies. However, new approaches remain highly desired because such treatments are not equally effective for all patients, and toxicity issues remain. We have taken a sy...

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

authors： Chen J,Peterson KR,Iancu-Rubin C,Bieker JJ

更新日期：2010-09-28 00:00:00

abstract：:The difficulty of achieving robust functional expression of insect nicotinic acetylcholine receptors (nAChRs) has hampered our understanding of these important molecular targets of globally deployed neonicotinoid insecticides at a time when concerns have grown regarding the toxicity of this chemotype to insect pollina...

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

authors： Ihara M,Furutani S,Shigetou S,Shimada S,Niki K,Komori Y,Kamiya M,Koizumi W,Magara L,Hikida M,Noguchi A,Okuhara D,Yoshinari Y,Kondo S,Tanimoto H,Niwa R,Sattelle DB,Matsuda K

更新日期：2020-07-14 00:00:00

abstract：:Historically, the biodiversity and composition of species in a locality was thought to be influenced primarily by deterministic factors. In such cases, species' niches create differential responses to environmental conditions and interspecific interactions, which combine to determine that locality's biodiversity and s...

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

authors： Chase JM

更新日期：2007-10-30 00:00:00

abstract：:Fast neurotransmission requires that docked synaptic vesicles be located near the presynaptic N-type or P/Q-type calcium channels. Specific protein-protein interactions between a synaptic protein interaction (synprint) site on N-type and P/Q-type channels and the presynaptic SNARE proteins syntaxin, SNAP-25, and synap...

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

authors： Kim DK,Catterall WA

更新日期：1997-12-23 00:00:00

abstract：:Bones from a stratified sedimentary deposit in the Puu Naio Cave site on Maui, Hawaiian Islands, reveal the late Holocene extinction of 19 species of birds. The age of the sediment and associated fauna was determined by direct radiocarbon dating (tandem particle accelerator-mass spectrometer; TAMS) of amino acids extr...

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

authors： James HF,Stafford TW Jr,Steadman DW,Olson SL,Martin PS,Jull AJ,McCoy PC

更新日期：1987-04-01 00:00:00

abstract：:To study the similarity between a putative cloned mammalian release factor (RF) and tryptophanyl-tRNA synthetase (TRS), a recombinant rabbit RF fusion protein was expressed from prokaryotic expression vectors. Purified fractions of the fusion proteins were tested for TRS and RF activities. Addition of the fusion prote...

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

authors： Timchenko L,Caskey CT

更新日期：1994-03-29 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：:Cystic fibrosis (CF) is a recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. The most common symptoms include progressive lung disease and chronic digestive conditions. CF is the first human genetic disease to benefit from having five different species of animal models. De...

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

authors： Kim K,Lane EA,Saftien A,Wang H,Xu Y,Wirtz-Peitz F,Perrimon N

更新日期：2020-05-12 00:00:00

abstract：:Host cell binding is an essential step in colonization by many bacterial pathogens, and the Lyme disease agent, Borrelia burgdorferi, which colonizes multiple tissues, is capable of attachment to diverse cell types. Glycosaminoglycans (GAGs) are ubiquitously expressed on mammalian cells and are recognized by multiple ...

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

authors： Fischer JR,Parveen N,Magoun L,Leong JM

更新日期：2003-06-10 00:00:00

abstract：:Despite the prevalence of transposable elements in the genomes of higher eukaryotes, what is virtually unknown is how they amplify to very high copy numbers without killing their host. Here, we report the discovery of rice strains where a miniature inverted-repeat transposable element (mPing) has amplified from approx...

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

authors： Naito K,Cho E,Yang G,Campbell MA,Yano K,Okumoto Y,Tanisaka T,Wessler SR

更新日期：2006-11-21 00:00:00

abstract：:B-1 B cells have been proposed to be preferentially generated from fetal progenitors, but this view is challenged by studies concluding that B-1 production is sustained throughout adult life. To address this controversy, we compared the efficiency with which hematopoietic stem cells (HSCs) and common lymphoid progenit...

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

authors： Barber CL,Montecino-Rodriguez E,Dorshkind K

更新日期：2011-08-16 00:00:00

abstract：:DEAD-box RNA helicase proteins use the energy of ATP hydrolysis to drive the unwinding of duplex RNA. However, the mechanism that couples ATP utilization to duplex RNA unwinding is unknown. We measured ATP utilization and duplex RNA unwinding by DbpA, a non-processive bacterial DEAD-box RNA helicase specifically activ...

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

authors： Henn A,Cao W,Licciardello N,Heitkamp SE,Hackney DD,De La Cruz EM

更新日期：2010-03-02 00:00:00

abstract：:Embryogenesis requires the precise activation and repression of many transcriptional regulators. The Polycomb group proteins and the associated H3K27me3 histone mark are essential to maintain the inactive state of many of these genes. Mammalian Hox genes are targets of Polycomb proteins and form local 3D clusters cent...

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

authors： Vieux-Rochas M,Fabre PJ,Leleu M,Duboule D,Noordermeer D

更新日期：2015-04-14 00:00:00

abstract：:In this study, we compared the transport of newly synthesized cholesterol with that of influenza virus hemagglutinin (HA) from the endoplasmic reticulum to the plasma membrane. The arrival of cholesterol on the cell surface was monitored by cyclodextrin removal, and HA transport was monitored by surface trypsinization...

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

authors： Heino S,Lusa S,Somerharju P,Ehnholm C,Olkkonen VM,Ikonen E

更新日期：2000-07-18 00:00:00

abstract：:Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S(0)) as a quick-reacting fungi...

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

authors： Hinckley EL,Matson PA

更新日期：2011-08-23 00:00:00

abstract：:Interleukin 1 (IL-1) is a two-member family of proteins (IL-1 alpha and IL-1 beta) that mediates a diverse series of immune and inflammatory responses. These two proteins have only 26% amino acid homology yet bind to the same receptor. It is of importance to define the active sites of these molecules in order to under...

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

authors： Mosley B,Dower SK,Gillis S,Cosman D

更新日期：1987-07-01 00:00:00

abstract：:Studies of perception usually emphasize processes that are largely universal across observers and--except for short-term fluctuations--stationary over time. Here we test the universality and stationarity assumptions with two families of ambiguous visual stimuli. Each stimulus can be perceived in two different ways, pa...

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

authors： Wexler M,Duyck M,Mamassian P

更新日期：2015-12-01 00:00:00

abstract：:The recent demonstration of K+ channel dysfunction in fibroblasts from Alzheimer disease (AD) patients and past observations of Ca(2+)-mediated K+ channel modulation during memory storage suggested that AD, which is characterized by memory loss and other cognitive deficits, might also involve dysfunction of intracellu...

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

authors： Ito E,Oka K,Etcheberrigaray R,Nelson TJ,McPhie DL,Tofel-Grehl B,Gibson GE,Alkon DL

更新日期：1994-01-18 00:00:00

abstract：:I measured the strength of interaction between a marine herbivore and its growing resource over a realistic range of absolute and relative abundances. The herbivores (hermit crabs: Pagurus spp.) have slow and/or weak functional and numerical responses to epiphytic diatoms (Isthmia nervosa), which show logistic growth ...

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

authors： Ruesink JL

更新日期：1998-06-09 00:00:00

abstract：:A discrepancy of about 20% exists between the molecular weight of the alpha subunit of Torpedo californica electroplax acetylcholine receptor as determined by gel electrophoresis of the mature protein (Mr 40,000 +/- 2000) and by nucleotide sequence analysis of cDNA (Mr approximately equal to 50,000). We demonstrate by...

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

authors： Conti-Tronconi BM,Hunkapiller MW,Raftery MA

更新日期：1984-05-01 00:00:00

abstract：:Studies of the accelerated aging disorder Hutchinson-Gilford progeria syndrome (HGPS) can potentially reveal cellular defects associated with physiological aging. HGPS results from expression and abnormal nuclear envelope association of a farnesylated, truncated variant of prelamin A called "progerin." We surveyed the...

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

authors： Chang W,Wang Y,Luxton GWG,Östlund C,Worman HJ,Gundersen GG

更新日期：2019-02-26 00:00:00