Large extinctions in an evolutionary model: the role of innovation and keystone species.

abstract：:Morphine produces analgesia at opiate receptors expressed in nociceptive circuits. mu, delta, and kappa opiate receptor subtypes are expressed in circuits that can modulate nociception and receive inputs from endogenous opioid neuropeptide ligands. The roles played by each receptor subtype in nociceptive processing in...

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

authors： Sora I,Takahashi N,Funada M,Ujike H,Revay RS,Donovan DM,Miner LL,Uhl GR

更新日期：1997-02-18 00:00:00

abstract：:Identification of the underlying molecular mechanisms for a derived phenotype by adaptive evolution is difficult. Here, we performed a systems-level inquiry into the metabolic changes occurring in the yeast Saccharomyces cerevisiae as a result of its adaptive evolution to increase its specific growth rate on galactose...

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

authors： Hong KK,Vongsangnak W,Vemuri GN,Nielsen J

更新日期：2011-07-19 00:00:00

abstract：:Magnitudes of the larger Soviet underground nuclear weapons tests from the start of the Threshold Test Ban Treaty in 1976 through 1982 are determined for short- and long-period seismic waves. Yields are calculated from the surface wave magnitude for those explosions at the eastern Kazakh test site that triggered a sma...

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

authors： Sykes LR,Cifuentes IL

更新日期：1984-03-01 00:00:00

abstract：:Regulatory T cells (Tregs) are key modulators of immune tolerance, capable of suppressing inflammatory immune responses and promoting nonlymphoid tissue homeostasis. Helios, a transcription factor (TF) that is selectively expressed by Tregs, has been shown to be essential for the maintenance of Treg lineage stability ...

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

authors： Yates K,Bi K,Haining WN,Cantor H,Kim HJ

更新日期：2018-02-27 00:00:00

abstract：:By considering temperature effects on the mechanical unfolding rates of proteins and RNA, whose energy landscape is rugged, the question posed in the title is answered in the affirmative. Adopting a theory by Zwanzig [Zwanzig, R. (1988) Proc. Natl. Acad. Sci. USA 85, 2029-2030], we show that, because of roughness char...

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

authors： Hyeon C,Thirumalai D

更新日期：2003-09-02 00:00:00

abstract：:The dansyl-conjugated (Dns) peptides Dns-Pro-Gly-Gly-Gln-Gln-Ile-Val and Dns-Ala-Gln-Gln-Ile-Val, patterned on the N-terminal sequence of fibronectin, were synthesized and used for the transglutaminase (protein-glutamine:amine gamma-glutamyltransferase, EC 2.3.2.13)-directed selective blocking of lens proteins that ot...

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

authors： Lorand L,Parameswaran KN,Velasco PT

更新日期：1991-01-01 00:00:00

abstract：:We present a method for predicting protein folding class based on global protein chain description and a voting process. Selection of the best descriptors was achieved by a computer-simulated neural network trained on a data base consisting of 83 folding classes. Protein-chain descriptors include overall composition, ...

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

authors： Dubchak I,Muchnik I,Holbrook SR,Kim SH

更新日期：1995-09-12 00:00:00

abstract：:Among the "beyond Li-ion" battery chemistries, nonaqueous Li-O2 batteries have the highest theoretical specific energy and, as a result, have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O2 batteries is the electronically insulating nature of the p...

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

authors： Burke CM,Pande V,Khetan A,Viswanathan V,McCloskey BD

更新日期：2015-07-28 00:00:00

abstract：:Periodical cicadas are well known for their prime-numbered life cycles (17 and 13 years) and their mass periodical emergences. The origination and persistence of prime-numbered cycles are explained by the hybridization hypothesis on the basis of their lower likelihood of hybridization with other cycles. Recently, we s...

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

authors： Tanaka Y,Yoshimura J,Simon C,Cooley JR,Tainaka K

更新日期：2009-06-02 00:00:00

abstract：:Voltage-dependent anion channels (VDACs) are pore-forming proteins (porins) that form the major pathway for movement of adenine nucleotides through the outer mitochondrial membrane. Electrophysiological studies indicate that VDAC-like channel activity is also prevalent in the cell membranes of many mammalian cells. Ho...

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

authors： Buettner R,Papoutsoglou G,Scemes E,Spray DC,Dermietzel R

更新日期：2000-03-28 00:00:00

abstract：:B-DNA becomes unstable under superhelical stress and is able to adopt a wide range of alternative conformations including strand-separated DNA and Z-DNA. Localized sequence-dependent structural transitions are important for the regulation of biological processes such as DNA replication and transcription. To directly p...

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

authors： Oberstrass FC,Fernandes LE,Bryant Z

更新日期：2012-04-17 00:00:00

abstract：:Mechanism of photo-induced electron transfer and the subsequent hole transfer in DNA has been studied extensively, but so far we are not aware of any reliable report of the observation of the long-distance hole-transfer process. In this article, we demonstrate the results of direct observation for the long-distance ho...

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

authors： Takada T,Kawai K,Fujitsuka M,Majima T

更新日期：2004-09-28 00:00:00

abstract：:Exposure of receptor-rich membrane fragments from Torpedo marmorata to carbamylcholine causes a slow (half-time of 5--10 min) and reversible change of properties of the cholinergic receptor protein manifested by a decrease of the initial rate of Naja nigricollis alpha-[3H]toxin binding in the presence of carbamylcholi...

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

authors： Weber M,David-Pfeuty T,Changeux JP

更新日期：1975-09-01 00:00:00

abstract：:Recent cryoEM density maps of Abeta(42) fibrils obtained at low pH revealed two protofilaments winding around a hollow core raising the question if such tubular structures also exist at physiological pH. Based on the cryoEM measurements and on NMR data, we probe amyloid fibril organizations corresponding to the observ...

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

authors： Miller Y,Ma B,Tsai CJ,Nussinov R

更新日期：2010-08-10 00:00:00

abstract：:Protein delivery to restricted plasma membrane domains is exquisitely regulated at different stages of the cell trafficking machinery. Traffic control involves the recognition of export/retention/retrieval signals in the endoplasmic reticulum (ER)/Golgi complex that will determine protein fate. A splice variant (SV), ...

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

authors： Zarei MM,Eghbali M,Alioua A,Song M,Knaus HG,Stefani E,Toro L

更新日期：2004-07-06 00:00:00

abstract：:The rate constants for CO binding to the five-coordinate ferrous iron complexes of 5,10,15,20-[pyromellitoyl(tetrakis-o-oxyoxyphenyl)]porphyrin and 5,10,15,20-[pyromellitoyl(tetrakis-o-oxypropoxyphenyl)]porphyrin have been measured and compared with the corresponding rate constants for other hemes and hemoproteins. Th...

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

authors： Rose EJ,Venkatasubramanian PN,Swartz JC,Jones RD,Basolo F,Hoffman BM

更新日期：1982-09-01 00:00:00

abstract：:Formation of neural circuits depends on stable contacts between neuronal processes, mediated by interaction of cell adhesion molecules, including N-cadherin. In the present study, we found that activity-dependent dendrite arborization specifically requires N-cadherin-mediated extracellular neuron-neuron interaction, b...

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

authors： Tan ZJ,Peng Y,Song HL,Zheng JJ,Yu X

更新日期：2010-05-25 00:00:00

abstract：:Reactive oxygen species (ROS) mediate apoptosis in many different cell types. We have previously shown that the antioxidant Mn(III) tetrakis(5,10,15,20-benzoic acid)porphyrin (MnTBAP) decreased intracellular ROS and prevented the apoptosis of activated T cells in vitro. To determine the mechanism(s) by which MnTBAP af...

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

authors： Hildeman DA,Mitchell T,Aronow B,Wojciechowski S,Kappler J,Marrack P

更新日期：2003-12-09 00:00:00

abstract：:The retrosplenial cortex (RSC) is part of a network of interconnected cortical, hippocampal, and thalamic structures harboring spatially modulated neurons. The RSC contains head direction cells and connects to the parahippocampal region and anterior thalamus. Manipulations of the RSC can affect spatial and contextual ...

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

authors： Czajkowski R,Jayaprakash B,Wiltgen B,Rogerson T,Guzman-Karlsson MC,Barth AL,Trachtenberg JT,Silva AJ

更新日期：2014-06-10 00:00:00

abstract：:The androgen receptor (AR) binds to androgen response elements and regulates target genes via a mechanism involving coregulators. Here we demonstrate that the AR can interact with the testicular orphan receptor-4 (TR4) and function as a repressor to down-regulate the TR4 target genes by preventing the TR4 binding to i...

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

authors： Lee YF,Shyr CR,Thin TH,Lin WJ,Chang C

更新日期：1999-12-21 00:00:00

abstract：:Certain mutations at the glaB locus result in the failure to fully derepress glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] and to convert it to the active nonadenylylated form in response to nitrogen limitation. In these mutants the PII regulatory protein is altered such that it cannot be...

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

authors： Foor F,Reuveny Z,Magasanik B

更新日期：1980-05-01 00:00:00

abstract：:We describe a new computer program, trilogy, for the automated discovery of sequence-structure patterns in proteins. trilogy implements a pattern discovery algorithm that begins with an exhaustive analysis of flexible three-residue patterns; a subset of these patterns are selected as seeds for an extension process in ...

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

authors： Bradley P,Kim PS,Berger B

更新日期：2002-06-25 00:00:00

abstract：:Combined effects of two drugs present simultaneously are usually expressed as summation, synergism or potentiation, and antagonism. When the sum of the effects of each drug present separately equals the combined effect of the two drugs present simultaneously, the action is called additive or summation. However, the ex...

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

authors： Kamaya H,Ueda I,Eyring H

更新日期：1976-06-01 00:00:00

abstract：:Pancreatic beta cells respond to changes in blood glucose by secreting insulin and increasing insulin synthesis. To identify genes used in these responses, we have carried out expression profiling of beta cells exposed to high (25 mM) or low (5.5 mM) glucose by using oligonucleotide microarrays. Functional clustering ...

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

authors： Webb GC,Akbar MS,Zhao C,Steiner DF

更新日期：2000-05-23 00:00:00

abstract：:A nitrogenase-inspired biomimetic chalcogel system comprising double-cubane [Mo2Fe6S8(SPh)3] and single-cubane (Fe4S4) biomimetic clusters demonstrates photocatalytic N2 fixation and conversion to NH3 in ambient temperature and pressure conditions. Replacing the Fe4S4 clusters in this system with other inert ions such...

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

authors： Liu J,Kelley MS,Wu W,Banerjee A,Douvalis AP,Wu J,Zhang Y,Schatz GC,Kanatzidis MG

更新日期：2016-05-17 00:00:00

abstract：:Export of LDL-derived cholesterol from lysosomes requires the cooperation of the integral membrane protein Niemann-Pick C1 (NPC1) and a soluble protein, Niemann-Pick C2 (NPC2). Mutations in the genes encoding these proteins lead to Niemann-Pick disease type C (NPC). NPC2 binds to NPC1's second (middle), lumenally orie...

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

authors： Li X,Saha P,Li J,Blobel G,Pfeffer SR

更新日期：2016-09-06 00:00:00

abstract：:The three-dimensional structures of the inactive protein precursors (zymogens) of the serine, cysteine, aspartic, and metalloprotease classes of proteolytic enzymes are known. Comparisons of these structures with those of the mature, active proteases reveal that, in general, the preformed, active conformations of the ...

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

authors： Khan AR,Khazanovich-Bernstein N,Bergmann EM,James MN

更新日期：1999-09-28 00:00:00

abstract：:Let T(k) (epsilon)(lambda; t(1),..., t(k)) = rho(X(t) (1))q(epsilon)(X(t) (2) - X(t) (1))... q(epsilon)(X(t(k) ) - X(t(k) )-1), where X(t) is a Brownian motion in R(2), lambda(dx) = rho(x)dx, and q(epsilon) converges to Dirac's delta function as epsilon downward arrow 0. The self-intersection local times of order k ar...

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

authors： Dynkin EB

更新日期：1986-06-01 00:00:00

abstract：:Murine endothelial cells are readily transformed in a single step by the polyomavirus oncogene encoding middle-sized tumor antigen. These cells (bEND.3) form tumors (hemangiomas) in mice which are lethal in newborn animals. The bEND.3 cells rapidly proliferate in culture and express little or no thrombospondin 1 (TS1)...

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

authors： Sheibani N,Frazier WA

更新日期：1995-07-18 00:00:00

abstract：:Mechanisms leading to down-regulation of activated microglia and astrocytes are poorly understood, in spite of the potentially detrimental role of activated glia in neurodegeneration. Prostaglandins, produced both by neurons and glia, may serve as mediators of glial and neuronal functions. We examined the influence of...

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

authors： Petrova TV,Akama KT,Van Eldik LJ

更新日期：1999-04-13 00:00:00