Four-dimensional ultrafast electron microscopy.

abstract：:We have identified and isolated a presumptive leukemogenic provirus from myeloblasts of a chicken in which leukemia had been induced by avian myeloblastosis virus (AMV). Leukemic myeloblasts isolated from peripheral blood or from converted yolk sac cultures of various strains of chickens, regardless of the endogenous ...

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

authors： Souza LM,Komaromy MC,Baluda MA

更新日期：1980-05-01 00:00:00

abstract：:Previous studies have identified human breast tumor particles possessing many of the features characteristic of RNA tumor viruses. In addition to the expected size (600 S) and density (1.16 g/ml) these include possession of an outer membrane and an inner one surrounding a "core" containing a DNA polymerase and a large...

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

authors： Ohno T,Sweet RW,Dejak D,Spiegelman S

更新日期：1977-02-01 00:00:00

abstract：:Sleep is recognized as a physiological state associated with learning, with studies showing that knowledge acquisition improves with naps. Little work has examined sleep-dependent learning in people with developmental disorders, for whom sleep quality is often impaired. We examined the effect of natural, in-home naps ...

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

authors： Spanò G,Gómez RL,Demara BI,Alt M,Cowen SL,Edgin JO

更新日期：2018-11-13 00:00:00

abstract：:Tail-anchored (TA) membrane proteins are involved in a variety of important cellular functions, including membrane fusion, protein translocation, and apoptosis. The ATPase Get3 (Asna1, TRC40) was identified recently as the endoplasmic reticulum targeting factor of TA proteins. Get3 consists of an ATPase and alpha-heli...

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

authors： Bozkurt G,Stjepanovic G,Vilardi F,Amlacher S,Wild K,Bange G,Favaloro V,Rippe K,Hurt E,Dobberstein B,Sinning I

更新日期：2009-12-15 00:00:00

abstract：:We measured the dependence of the variance in the rotation rate of tethered cells of Escherichia coli on the mean rotation rate over a regime in which the motor generates constant torque. This dependence was compared with that of broken motors. In either case, motor torque was augmented with externally applied torque....

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

authors： Samuel AD,Berg HC

更新日期：1995-04-11 00:00:00

abstract：:Organ graft rejection is a T-cell-dependent process. The activation of alloreactive T cells requires stimulation of the T-cell receptor/CD3 complex by foreign major histocompatibility complex (MHC)-encoded gene products. However, accumulating evidence suggests that, in addition to T-cell receptor occupancy, other cost...

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

authors： Turka LA,Linsley PS,Lin H,Brady W,Leiden JM,Wei RQ,Gibson ML,Zheng XG,Myrdal S,Gordon D

更新日期：1992-11-15 00:00:00

abstract：:In an fMRI experiment, participants were exposed to narratives based on true stories designed to evoke admiration and compassion in 4 distinct categories: admiration for virtue (AV), admiration for skill (AS), compassion for social/psychological pain (CSP), and compassion for physical pain (CPP). The goal was to test ...

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

authors： Immordino-Yang MH,McColl A,Damasio H,Damasio A

更新日期：2009-05-12 00:00:00

abstract：:The improvement of motor behavior, based on experience, is a form of learning that is critically dependent on the cerebellum. A well studied example of cerebellar motor learning is short-term saccadic adaptation (STSA). In STSA, information on saccadic errors is used to improve future saccades. The information optimiz...

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

authors： Catz N,Dicke PW,Thier P

更新日期：2008-05-20 00:00:00

abstract：:Neuronal hyperexcitability in both injured and adjacent uninjured neurons is associated with states of chronic injury and pain and is likely subject to neuroinflammatory processes. Chronic inflammatory responses are largely orchestrated by chemokines. One chemokine, monocyte chemoattractant protein-1 (MCP-1), in the p...

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

authors： White FA,Sun J,Waters SM,Ma C,Ren D,Ripsch M,Steflik J,Cortright DN,Lamotte RH,Miller RJ

更新日期：2005-09-27 00:00:00

abstract：:As a structure involved in learning and memory, the hippocampus functions as a network. The functional differentiation along the longitudinal axis of the hippocampus is poorly demarcated in comparison with the transverse axis. Using patch clamp recordings in conjunction with post hoc anatomy, we have examined the patt...

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

authors： Gloveli T,Dugladze T,Rotstein HG,Traub RD,Monyer H,Heinemann U,Whittington MA,Kopell NJ

更新日期：2005-09-13 00:00:00

abstract：:Despite the importance of aggression in the behavioral repertoire of most animals, relatively little is known of its proximate causation and control. To take advantage of modern methods of genetic analysis for studying this complex behavior, we have developed a quantitative framework for studying aggression in common ...

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

authors： Chen S,Lee AY,Bowens NM,Huber R,Kravitz EA

更新日期：2002-04-16 00:00:00

abstract：:We have used X-ray diffraction on the rhombohedral phospholipid phase to reconstruct stalk structures in different pure lipids and lipid mixtures with unprecedented resolution, enabling a quantitative analysis of geometry, as well as curvature and hydration energies. Electron density isosurfaces are used to study shap...

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

authors： Aeffner S,Reusch T,Weinhausen B,Salditt T

更新日期：2012-06-19 00:00:00

abstract：:A fundamental property of ecosystems is a tradeoff between the number and size of habitats: as the number of habitats within a fixed area increases, the average area per habitat must decrease. This tradeoff is termed the "area-heterogeneity tradeoff." Theoretical models suggest that the reduction in habitat sizes unde...

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

authors： Ben-Hur E,Kadmon R

更新日期：2020-03-03 00:00:00

abstract：:Heparinase I from Flavobacterium heparinum has important uses for elucidating the complex sequence heterogeneity of heparin-like glycosaminoglycans (HLGAGs). Understanding the biological function of HLGAGs has been impaired by the limited methods for analysis of pure or mixed oligosaccharide fragments. Here, we use me...

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

authors： Ernst S,Rhomberg AJ,Biemann K,Sasisekharan R

更新日期：1998-04-14 00:00:00

abstract：:We have characterized seven murine retinoic acid receptor gamma cDNA isoforms (mRAR-gamma 1 to -gamma 7) generated by alternative splicing of at least seven exons. These isoforms differ from one another in their 5' untranslated region and in two cases (mRAR-gamma 1 and -gamma 2) differ in their N-terminal A region, wh...

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

authors： Kastner P,Krust A,Mendelsohn C,Garnier JM,Zelent A,Leroy P,Staub A,Chambon P

更新日期：1990-04-01 00:00:00

abstract：:The succession from aerobic and facultative anaerobic bacteria to obligate anaerobes in the infant gut along with the differences between the compositions of the mucosally adherent vs. luminal microbiota suggests that the gut microbes consume oxygen, which diffuses into the lumen from the intestinal tissue, maintainin...

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

authors： Friedman ES,Bittinger K,Esipova TV,Hou L,Chau L,Jiang J,Mesaros C,Lund PJ,Liang X,FitzGerald GA,Goulian M,Lee D,Garcia BA,Blair IA,Vinogradov SA,Wu GD

更新日期：2018-04-17 00:00:00

abstract：:Neuroglobin (Ngb), a vertebrate globin expressed primarily in neurons, is induced by and protects against neuronal hypoxia and cerebral ischemia. To investigate the spectrum and mechanism of Ngb's neuroprotective action, we studied the effect of transgenic overexpression of Ngb on NMDA and beta-amyloid (Abeta) toxicit...

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

authors： Khan AA,Mao XO,Banwait S,Jin K,Greenberg DA

更新日期：2007-11-27 00:00:00

abstract：:The thesis is developed that a low oxygen level Precambrian atmosphere presented early-evolving metazoan organisms with physiological connective tissue priorities resulting from the important molecular oxygen requirements in the biosynthesis of collagen hydroxyproline. Shells, cuticles, and carapaces which are not man...

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

authors： Towe KM

更新日期：1970-04-01 00:00:00

abstract：:Ethionamide (ETA) is an important component of second-line therapy for the treatment of multidrug-resistant tuberculosis. Synthesis of radiolabeled ETA and an examination of drug metabolites formed by whole cells of Mycobacterium tuberculosis (MTb) have allowed us to demonstrate that ETA is activated by S-oxidation be...

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

authors： DeBarber AE,Mdluli K,Bosman M,Bekker LG,Barry CE 3rd

更新日期：2000-08-15 00:00:00

abstract：:Although they lie at the conceptual core of a wide range of scientific questions, the notions of irregular or "random" arrangement and the process of randomization itself have never been unambiguously defined. Algorithmic implementation of these concepts requires a combinatorial, rather than a probability-theoretic, f...

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

authors： Singer BH,Pincus S

更新日期：1998-02-17 00:00:00

abstract：:The origin recognition complex (ORC) is an essential component of the prereplication complex (pre-RC) in mitotic cell cycles. The role of ORC as a foundation to assemble the pre-RC is conserved from yeast to human. Furthermore, in metazoans ORC plays a key role in determining the timing of replication initiation and o...

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

authors： Park SY,Asano M

更新日期：2008-08-26 00:00:00

abstract：:Adenosine 3':5'-cyclic monophosphate added to exponentially growing cells of Hemophilus influenzae strain Rd increases competence for transformation 100- to 10,000-fold. Cyclic AMP added to near-stationary or stationary cells does not increase competence over the high level normally found in the early stationary phase...

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

authors： Wise EM Jr,Alexander SP,Powers M

更新日期：1973-02-01 00:00:00

abstract：:In this report we provide evidence that neuronal nicotinic acetylcholine receptors (nAChRs) are present on hippocampal astrocytes and their activation produces rapid currents and calcium transients. Our data indicate that these responses obtained from astrocytes are primarily mediated by an AChR subtype that is functi...

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

authors： Sharma G,Vijayaraghavan S

更新日期：2001-03-27 00:00:00

abstract：:Limited trypsinization of the fatty acid synthetase multienzyme complex from rat mammary gland results in the release of a protein, molecular weight 32,000, with thioesterase activity. The other components of the multienzyme complex--the acyl carrier protein, acetyl and malonyl transferases, condensing enzyme, keto re...

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

authors： Smith S,Agradi E,Libertini L,Dileepan KN

更新日期：1976-04-01 00:00:00

abstract：:Polycomb-group (Pc-G) proteins ensure late maintenance of transcriptional repression outside the expression domain of target genes in flies and vertebrates. They act in complexes, presumably by modulating chromatin structure. In Drosophila, they have been found to be associated with transcriptionally inactive loci but...

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

authors： d Graaff W,Tomotsune D,Oosterveen T,Takihara Y,Koseki H,Deschamps J

更新日期：2003-11-11 00:00:00

abstract：:Cellular and molecular signals involved in axon elongation versus collateral and arbor formation may be intrinsic to developing neurons, or they may derive from targets. To identify signals regulating axon growth modes, we have developed a culture system in which trigeminal ganglion cells are challenged by various tar...

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

authors： Erzurumlu RS,Jhaveri S,Takahashi H,McKay RD

更新日期：1993-08-01 00:00:00

abstract：:Organic substances can adopt an amorphous solid or semisolid state, influencing the rate of heterogeneous reactions and multiphase processes in atmospheric aerosols. Here we demonstrate how molecular diffusion in the condensed phase affects the gas uptake and chemical transformation of semisolid organic particles. Flo...

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

authors： Shiraiwa M,Ammann M,Koop T,Pöschl U

更新日期：2011-07-05 00:00:00

abstract：:An inwardly rectifying, ATP-regulated K+ channel with a distinctive molecular architecture, ROMK1, was recently cloned from rat kidney. Using patch clamp techniques, we have investigated the regulation of ROMK1 with particular emphasis on phosphorylation/dephosphorylation processes. Spontaneous channel rundown occurre...

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

authors： McNicholas CM,Wang W,Ho K,Hebert SC,Giebisch G

更新日期：1994-08-16 00:00:00

abstract：:Acquired resistance to androgen receptor (AR)-targeted therapies compels the development of novel treatment strategies for castration-resistant prostate cancer (CRPC). Here, we report a profound effect of endostatin on prostate cancer cells by efficient intracellular trafficking, direct interaction with AR, reduction ...

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

authors： Lee JH,Isayeva T,Larson MR,Sawant A,Cha HR,Chanda D,Chesnokov IN,Ponnazhagan S

更新日期：2015-02-03 00:00:00

abstract：:Regulation of the sterol-synthesizing mevalonate pathway occurs in part through feedback-regulated endoplasmic reticulum degradation of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-R). In yeast, the Hmg2p isozyme of HMG-R is regulated in this manner. We have tested the involvement of ubiquitination in the regulated d...

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

authors： Hampton RY,Bhakta H

更新日期：1997-11-25 00:00:00