On a notion of simplicial depth.

abstract：:The mechanical properties of engineering structures continuously weaken during service life because of material fatigue or degradation. By contrast, living organisms are able to strengthen their mechanical properties by regenerating parts of their structures. For example, plants strengthen their cell structures by tra...

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

authors： Yu K,Feng Z,Du H,Xin A,Lee KH,Li K,Su Y,Wang Q,Fang NX,Daraio C

更新日期：2021-01-19 00:00:00

abstract：:Orai1 and stromal interaction molecule 1 (STIM1) mediate store-operated Ca(2+) entry (SOCE) in immune cells. STIM1, an endoplasmic reticulum (ER) Ca(2+) sensor, detects store depletion and interacts with plasma membrane (PM)-resident Orai1 channels at the ER-PM junctions. However, the molecular composition of these ju...

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

authors： Woo JS,Srikanth S,Nishi M,Ping P,Takeshima H,Gwack Y

更新日期：2016-03-08 00:00:00

abstract：:We have sequenced the mutant beta-actin gene of a tumorigenic human fibroblast cell line (HuT-14T) and found that it carries three mutations that alter the amino acids at positions 36, 83, and 244 as well as a 22-base-pair "insertion" sequence, in the 5' intron, not present in a wild-type gene. The less tumorigenic ce...

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

authors： Lin CS,Ng SY,Gunning P,Kedes L,Leavitt J

更新日期：1985-10-01 00:00:00

abstract：:A coarse-grained model for protein-folding dynamics is introduced based on a discretized representation of torsional modes. The model, based on the Ramachandran map of the local torsional potential surface and the class (hydrophobic/polar/neutral) of each residue, recognizes patterns of both torsional conformations an...

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

authors： Fernández A,Kostov K,Berry RS

更新日期：1999-11-09 00:00:00

abstract：:The RNA-directed DNA polymerase (deoxynucleosidetriphosphate:DNA deoxynucleotidyltransferase EC 2.7.7.7) of avian oncornavirus requires a tryptophan tRNA (tRNATrp) primer molecule located close to the 5' end of the viral RNA genome for the initiation of DNA synthesis in vitro. In this communication we demonstrate that...

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

authors： Collett MS,Faras AJ

更新日期：1976-04-01 00:00:00

abstract：:Global loss of DNA methylation has been known for decades as an epigenomic aberration associated with carcinogenesis and cancer progression. Loss of DNA methylation affects predominantly repetitive elements, which encompass >50% of the CpG dinucleotides present in the human genome. Because of the lack of an effective ...

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

authors： Xie H,Wang M,Bonaldo Mde F,Rajaram V,Stellpflug W,Smith C,Arndt K,Goldman S,Tomita T,Soares MB

更新日期：2010-04-13 00:00:00

abstract：:The requirement for protein synthesis in the mechanism of a circadian pacemaker was investigated by using inhibitors of protein synthesis. Continuous treatment of the ocular circadian pacemaker of the mollusc Bulla gouldiana with anisomycin or cycloheximide substantially lengthened (up to 39 and 52 hr, respectively) t...

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

authors： Khalsa SB,Whitmore D,Block GD

更新日期：1992-11-15 00:00:00

abstract：:The HIV envelope (Env) protein mediates entry into cells by binding CD4 and an appropriate coreceptor, which triggers structural changes in Env that lead to fusion between the viral and cellular membranes. The major HIV-1 coreceptors are the seven transmembrane domain chemokine receptors CCR5 and CXCR4. The type of co...

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

authors： Hoffman TL,Canziani G,Jia L,Rucker J,Doms RW

更新日期：2000-10-10 00:00:00

abstract：:The fluorescence of the supposedly buried tryptophan in ribonuclease T1 has been found to be collisionally quenched by acrylamide with a rate constant of 3 X 10(8) M--1 sec--1. Only a slight decrease in the quenching rate is observed upon a 5-fold increase in the viscosity of the solution. For this to be the case, the...

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

authors： Eftink MR,Ghiron CA

更新日期：1975-09-01 00:00:00

abstract：:Increases in cytoplasmic free calcium ([Ca2+]i) can be induced in resting B cells either by a low molecular weight (12-kDa) B-cell growth factor (LMW-BCGF) or by crosslinking the B-cell antigen CD19 with monoclonal antibody (mAb). LMW-BCGF causes a slow [Ca2+]i increase in peripheral blood and tonsillar B cells but ha...

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

authors： Ledbetter JA,Rabinovitch PS,June CH,Song CW,Clark EA,Uckun FM

更新日期：1988-03-01 00:00:00

abstract：:We measured the superconducting transition temperature of (6)Li between 16 and 26 GPa, and report the lightest system to exhibit superconductivity to date. The superconducting phase diagram of (6)Li is compared with that of (7)Li through simultaneous measurement in a diamond anvil cell (DAC). Below 21 GPa, Li exhibits...

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

authors： Schaeffer AM,Temple SR,Bishop JK,Deemyad S

更新日期：2015-01-06 00:00:00

abstract：:Gene function is typically evaluated by sampling the continuum of gene expression at only a few discrete points corresponding to gene knockout or overexpression. We argue that this characterization is incomplete and present a library of engineered promoters of varying strengths obtained through mutagenesis of a consti...

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

authors： Alper H,Fischer C,Nevoigt E,Stephanopoulos G

更新日期：2005-09-06 00:00:00

abstract：:After exposure of segments of rabbit taenia coli to the nonionic detergent Triton X-100, tension could be induced by increasing the [Ca2+] in the micromolar range. In the presence of a saturating [Ca2+], this preparation developed nearly 100% of the control tetanus tension recorded from the intact muscle prior to the ...

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

authors： Gordon AR

更新日期：1978-07-01 00:00:00

abstract：:Laminin, an ∼800-kDa heterotrimeric protein, is a major functional component of the extracellular matrix, contributing to tissue development and maintenance. The unique architecture of laminin is not currently amenable to determination at high resolution, as its flexible and narrow segments complicate both crystalliza...

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

authors： Armony G,Jacob E,Moran T,Levin Y,Mehlman T,Levy Y,Fass D

更新日期：2016-11-22 00:00:00

abstract：:Using direct percussion, language-competent bonobo-chimpanzees Kanzi and Pan-Banisha produced a significantly wider variety of flint tool types than hitherto reported, and used them task-specifically to break wooden logs or to dig underground for food retrieval. For log breaking, small flakes were rotated drill-like o...

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

authors： Roffman I,Savage-Rumbaugh S,Rubert-Pugh E,Ronen A,Nevo E

更新日期：2012-09-04 00:00:00

abstract：:Nonsense-mediated mRNA decay (NMD), which degrades transcripts harboring a premature termination codon (PTC), depends on the helicase up-frameshift 1 (UPF1). However, mRNAs that are not NMD targets also bind UPF1. What governs the timing, position, and function of UPF1 binding to mRNAs remains unclear. We provide evid...

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

authors： Kurosaki T,Maquat LE

更新日期：2013-02-26 00:00:00

abstract：:Contact-dependent growth inhibition (CDI) is a mechanism by which bacteria exchange toxins via direct cell-to-cell contact. CDI systems are distributed widely among Gram-negative pathogens and are thought to mediate interstrain competition. Here, we describe tsf mutations that alter the coiled-coil domain of elongatio...

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

authors： Jones AM,Garza-Sánchez F,So J,Hayes CS,Low DA

更新日期：2017-03-07 00:00:00

abstract：:In vitro incubation of leukemic bone marrow with the lipophilic fluorescent dye merocyanine 540 and simultaneous exposure to light reduced the concentration of L1210 leukemia cells by about 5 orders of magnitude but spared enough normal pluripotent hematopoietic stem cells to allow hematopoietic reconstitution of leth...

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

authors： Sieber F,Spivak JL,Sutcliffe AM

更新日期：1984-12-01 00:00:00

abstract：:Debate over the influence of postwildfire management on future fire severity is occurring in the absence of empirical studies. We used satellite data, government agency records, and aerial photography to examine a forest landscape in southwest Oregon that burned in 1987 and then was subject, in part, to salvage-loggin...

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

authors： Thompson JR,Spies TA,Ganio LM

更新日期：2007-06-19 00:00:00

abstract：:Droplet manipulation is playing an important role in various fields, including scientific research, industrial production, and daily life. Here, inspired by the microstructures and functions of Namib desert beetles, Nepenthes pitcher plants, and emergent aquatic plants, we present a multibioinspired slippery surface f...

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

authors： Zhang X,Sun L,Wang Y,Bian F,Wang Y,Zhao Y

更新日期：2019-10-15 00:00:00

abstract：:Nociceptive information is modulated by a large number of endogenous signaling agents that change over the course of recovery from injury. This plasticity makes understanding regulatory mechanisms involved in descending inhibition of pain scientifically and clinically important. Neurons that synthesize the neuropeptid...

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

authors： Dimitrov EL,Kuo J,Kohno K,Usdin TB

更新日期：2013-08-06 00:00:00

abstract：:Alveolar type II (AT2) cell dysfunction contributes to a number of significant human pathologies including respiratory distress syndrome, lung adenocarcinoma, and debilitating fibrotic diseases, but the critical transcription factors that maintain AT2 cell identity are unknown. Here we show that the E26 transformation...

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

authors： Zhang Z,Newton K,Kummerfeld SK,Webster J,Kirkpatrick DS,Phu L,Eastham-Anderson J,Liu J,Lee WP,Wu J,Li H,Junttila MR,Dixit VM

更新日期：2017-04-11 00:00:00

abstract：:Benthic foraminifers inhabit a wide range of aquatic environments including open marine, brackish, and freshwater environments. Here we show that several different and diverse foraminiferal groups (miliolids, rotaliids, textulariids) and Gromia, another taxon also belonging to Rhizaria, accumulate and respire nitrates...

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

authors： Piña-Ochoa E,Høgslund S,Geslin E,Cedhagen T,Revsbech NP,Nielsen LP,Schweizer M,Jorissen F,Rysgaard S,Risgaard-Petersen N

更新日期：2010-01-19 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 Chinese hamster ovary cell (CHO) mutant (strain 58), defective in CDP-choline synthetase (cholinephosphate cytidylyltransferase; CTP:cholinephosphate cytidylyltransferase, EC 2.7.7.15), is temperature sensitive for growth and contains less than half of the normal amount of phosphatidylcholine under nonpermissive con...

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

authors： Esko JD,Nishijima M,Raetz CR

更新日期：1982-03-01 00:00:00

abstract：:The ability to modulate the collective properties of correlated electron systems at their interfaces and surfaces underpins the burgeoning field of "designer" quantum materials. Here, we show how an electronic reconstruction driven by surface polarity mediates a Stoner-like magnetic instability to itinerant ferromagne...

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

authors： Mazzola F,Sunko V,Khim S,Rosner H,Kushwaha P,Clark OJ,Bawden L,Marković I,Kim TK,Hoesch M,Mackenzie AP,King PDC

更新日期：2018-12-18 00:00:00

abstract：:A careful review of the literature in political science and neighboring social science disciplines shows that prevailing assumptions in the international development policy community about improved governance as a principal mechanism to reduce poverty in Africa rests more on faith than science. Conventional policy mod...

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

authors： Hyden G

更新日期：2007-10-23 00:00:00

abstract：:Expression of alphavbeta3- or alphavbeta5-integrins and selectins is widespread on blood cells and endothelial cells. Here we report that human tumor cells injected s.c. into mice lacking beta3- or beta3/beta5-integrins or various selectins show enhanced tumor growth compared with growth in control mice. There was inc...

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

authors： Taverna D,Moher H,Crowley D,Borsig L,Varki A,Hynes RO

更新日期：2004-01-20 00:00:00

abstract：:Optical waveguides simultaneously transport light at different colors, forming the basis of fiber-optic telecommunication networks that shuttle data in dozens of spectrally separated channels. Here, we reimagine this wavelength division multiplexing (WDM) paradigm in a novel context--the differentiated detection and i...

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

authors： Ozcelik D,Parks JW,Wall TA,Stott MA,Cai H,Parks JW,Hawkins AR,Schmidt H

更新日期：2015-10-20 00:00:00

abstract：:Linear hierarchies, the classical pecking-order structures, are formed readily in both nature and the laboratory in a great range of species including humans. However, the probability of getting linear structures by chance alone is quite low. In this paper we investigate the two hypotheses that are proposed most often...

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

authors： Chase ID,Tovey C,Spangler-Martin D,Manfredonia M

更新日期：2002-04-16 00:00:00