Sulfur radical species form gold deposits on Earth.

abstract：:Controlling topological defects in 3D liquid crystal phases is a crucial element in the development of novel devices, from blue-phase displays to passive biochemical sensors. However, it remains challenging to realize the 3D topological conditions necessary to robustly and arbitrarily direct the formation of defects. ...

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

authors： Honglawan A,Beller DA,Cavallaro M Jr,Kamien RD,Stebe KJ,Yang S

更新日期：2013-01-02 00:00:00

abstract：:The rewards of promiscuity for males are undisputed. But why should a female mate promiscuously, particularly when her partners offer no resources other than sperm and increase her chances of succumbing to predation or disease? This question has been hotly debated but at present remains largely unresolved [Jennions, M...

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

authors： Evans JP,Magurran AE

更新日期：2000-08-29 00:00:00

abstract：:Endoproteolytic processing of the human protein C (HPC) precursor to its mature form involves cleavage of the propeptide after amino acids Lys-2-Arg-1 and removal of a Lys156-Arg157 dipeptide connecting the light and heavy chains. This processing was inefficient in the mammary gland of transgenic mice and pigs. We hyp...

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

authors： Drews R,Paleyanda RK,Lee TK,Chang RR,Rehemtulla A,Kaufman RJ,Drohan WN,Luboń H

更新日期：1995-11-07 00:00:00

abstract：:Heterosis is widely applied in agriculture; however, the underlying molecular mechanisms for superior performance are not well understood. Ethylene biosynthesis and signaling genes are shown to be down-regulated in Arabidopsis interspecific hybrids. Ethylene is a plant hormone that promotes fruit ripening and maturati...

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

authors： Song Q,Ando A,Xu D,Fang L,Zhang T,Huq E,Qiao H,Deng XW,Chen ZJ

更新日期：2018-05-22 00:00:00

abstract：:The counterintuitive features of quantum physics challenge many common-sense assumptions. In an interferometric quantum eraser experiment, one can actively choose whether or not to erase which-path information (a particle feature) of one quantum system and thus observe its wave feature via interference or not by perfo...

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

authors： Ma XS,Kofler J,Qarry A,Tetik N,Scheidl T,Ursin R,Ramelow S,Herbst T,Ratschbacher L,Fedrizzi A,Jennewein T,Zeilinger A

更新日期：2013-01-22 00:00:00

abstract：:A temperature-sensitive (ts) mutant, GA 907/7, was isolated after mutagen treatment of avian myeloblastosis virus. When bone marrow cells or secondary yolk sac macrophages were infected with GA 907/7, the expression of transformation was greatly reduced at 41 degrees C. The results of temperature-shift experiments sug...

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

authors： Moscovici MG,Moscovici C

更新日期：1983-03-01 00:00:00

abstract：:Three major oxidation products of 2'-deoxycytidine (dC)--5-hydroxy-2'-deoxycytidine (oh5dC), 5-hydroxy-2'-deoxyuridine (oh5dU), and 5,6-dihydroxy-5,6-dihydro-2'-deoxyuridine (dUg)--were analyzed from enzymatically hydrolyzed DNA with reversed-phase high-performance liquid chromatography coupled to electrochemical dete...

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

authors： Wagner JR,Hu CC,Ames BN

更新日期：1992-04-15 00:00:00

abstract：:We report here that during a permanent cardiac arrest, rodent brain tissue is "physiologically" preserved in situ in a particular quiescent state. This state is characterized by the absence of electrical activity and by a critical period of 5-6 hr during which brain tissue can be reactivated upon restoration of a simp...

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

authors： Charpak S,Audinat E

更新日期：1998-04-14 00:00:00

abstract：:HIV type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry into target cells. Here we show that the HIV-1 envelope gp120 (Env) activates multiple ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. Env from both CCR5-dependent JRFL (R5) an...

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

authors： Liu QH,Williams DA,McManus C,Baribaud F,Doms RW,Schols D,De Clercq E,Kotlikoff MI,Collman RG,Freedman BD

更新日期：2000-04-25 00:00:00

abstract：:DNA topoisomerase I (top1) is the target of potent anticancer agents, including camptothecins and DNA intercalators, which reversibly stabilize (trap) top1 catalytic intermediates (cleavage complexes). The aim of the present study was to define the structural relationship between the site(s) of covalently bound interc...

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

authors： Pommier Y,Laco GS,Kohlhagen G,Sayer JM,Kroth H,Jerina DM

更新日期：2000-09-26 00:00:00

abstract：:Two human B-cell differentiation antigens, Bp35 and Bp50, apparently play distinct roles as signal receptors in B-cell activation. Monoclonal antibodies (mAbs) to either Bp35 or Bp50 deliver positive signals to B cells that stimulate their transition through the cell cycle. mAb to Bp35, like anti-immunoglobulin antibo...

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

authors： Clark EA,Ledbetter JA

更新日期：1986-06-01 00:00:00

abstract：:Lon (or La) is a soluble, homooligomeric ATP-dependent protease. Mass determination and cryoelectron microscopy of pure mitochondrial Lon from Saccharomyces cerevisiae identify Lon as a flexible ring-shaped heptamer. In the presence of ATP or 5'-adenylylimidodiphosphate, most of the rings are symmetric and resemble ot...

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

authors： Stahlberg H,Kutejová E,Suda K,Wolpensinger B,Lustig A,Schatz G,Engel A,Suzuki CK

更新日期：1999-06-08 00:00:00

abstract：:Protein framework alterations in heritable Cu, Zn superoxide dismutase (SOD) mutants cause misassembly and aggregation in cells affected by the motor neuron disease ALS. However, the mechanistic relationship between superoxide dismutase 1 (SOD1) mutations and human disease is controversial, with many hypotheses postul...

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

authors： Pratt AJ,Shin DS,Merz GE,Rambo RP,Lancaster WA,Dyer KN,Borbat PP,Poole FL 2nd,Adams MW,Freed JH,Crane BR,Tainer JA,Getzoff ED

更新日期：2014-10-28 00:00:00

abstract：:We examined iron nitrosylation of non-heme protein and enzymatic activity of the Fe-S cluster protein, aconitase, in acute cardiac allograft rejection. Heterotopic transplantation of donor hearts was performed in histocompatibility matched (isografts: Lewis --> Lewis) and mismatched (allografts: Wistar-Furth --> Lewis...

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

authors： Pieper GM,Halligan NL,Hilton G,Konorev EA,Felix CC,Roza AM,Adams MB,Griffith OW

更新日期：2003-03-18 00:00:00

abstract：:Two operators, spatially separated from each other and from the promoters, repress the gal operon when bound to Gal repressor. Conversion of either gal operator to a lac operator results in derepression, although both Gal and Lac repressors are present, suggesting that mere occupation of operator sites is not sufficie...

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

authors： Haber R,Adhya S

更新日期：1988-12-01 00:00:00

abstract：:Complex II inhibitors 3-nitropropionic acid (3NP) and malonate cause striatal damage reminiscent of Huntington's disease and have been shown to involve oxidative stress in their pathogenesis. Because nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent transcriptional activation by means of the antioxidant res...

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

authors： Calkins MJ,Jakel RJ,Johnson DA,Chan K,Kan YW,Johnson JA

更新日期：2005-01-04 00:00:00

abstract：:Eosinophils have been associated with fibrosis. To investigate their direct role in fibrosis, human peripheral blood eosinophil sonicate was added to human lung or dermal fibroblasts, and proliferation ([(3)H]thymidine) and collagen synthesis ([(3)H]proline) were evaluated. Proliferation was enhanced significantly in ...

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

authors： Levi-Schaffer F,Garbuzenko E,Rubin A,Reich R,Pickholz D,Gillery P,Emonard H,Nagler A,Maquart FA

更新日期：1999-08-17 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：:Purified dihydropyridine-sensitive calcium channels from rabbit skeletal muscle were reconstituted into phosphatidylcholine vesicles to evaluate the effect of phosphorylation by cyclic AMP-dependent protein kinase (PK-A) on their function. Both the rate and extent of 45Ca2+ uptake into vesicles containing reconstitute...

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

authors： Nunoki K,Florio V,Catterall WA

更新日期：1989-09-01 00:00:00

abstract：:Antimicrobial peptides are postulated to disrupt microbial phospholipid membranes. The prevailing molecular model is based on the formation of stable or transient pores although the direct observation of the fundamental processes is lacking. By combining rational peptide design with topographical (atomic force microsc...

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

authors： Rakowska PD,Jiang H,Ray S,Pyne A,Lamarre B,Carr M,Judge PJ,Ravi J,Gerling UI,Koksch B,Martyna GJ,Hoogenboom BW,Watts A,Crain J,Grovenor CR,Ryadnov MG

更新日期：2013-05-28 00:00:00

abstract：:The neighbor-exclusion principle is one of the most general and interesting rules describing intercalative DNA binding by small molecules. It suggests that such binding can only occur at every other base-pair site, reflecting a very large negative cooperativity in the binding process. We have carried out molecular mec...

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

authors： Rao SN,Kollman PA

更新日期：1987-08-01 00:00:00

abstract：:Herpesviruses require a nuclear egress complex (NEC) for efficient transit of nucleocapsids from the nucleus to the cytoplasm. The NEC orchestrates multiple steps during herpesvirus nuclear egress, including disruption of nuclear lamina and particle budding through the inner nuclear membrane. In the important human pa...

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

authors： Leigh KE,Sharma M,Mansueto MS,Boeszoermenyi A,Filman DJ,Hogle JM,Wagner G,Coen DM,Arthanari H

更新日期：2015-07-21 00:00:00

abstract：:Treatment of cultured Hodgkin disease (HD) cells with neuraminidase results in decreased reactivity of monoclonal antibody VIM-D5 with its antigen, the X hapten, a fucosyl-N-acetyllactosamine. The other feature characteristic of HD cells is the expression of high levels of ectosialyltransferase activity. We present ev...

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

authors： Paietta E,Stockert RJ,Morell AG,Diehl V,Wiernik PH

更新日期：1986-05-01 00:00:00

abstract：:The cellular models generally used in the in vitro evaluation of anti-human immunodeficiency virus compounds are dividing cells. A model constituted by resting lymphocytes may more accurately reflect a drug's future efficacy in humans, since viral DNA synthesis is known to take place in quiescent cells, creating a res...

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

authors： Malley SD,Grange JM,Hamedi-Sangsari F,Vila JR

更新日期：1994-11-08 00:00:00

abstract：:Gene expression networks are complicated by the assortment of regulatory factors that bind DNA and modulate transcription combinatorially. Single-cell measurements can reveal biological mechanisms hidden by population averages, but their value has not been fully explored in the context of mRNA regulation. Here, we ada...

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

authors： Wang L,Brugge JS,Janes KA

更新日期：2011-10-04 00:00:00

abstract：:Ras is a guanine nucleotide-binding protein that cycles between inactive GDP-bound and active GTP-bound states to regulate a diverse array of cellular processes, including cell growth, apoptosis, and differentiation. The guanine nucleotide-bound state of Ras is tightly maintained by regulatory factors to promote regul...

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

authors： Williams JG,Pappu K,Campbell SL

更新日期：2003-05-27 00:00:00

abstract：:Site-directed mutagenesis of selected residues of mammalian protein phosphatase 1 (PP-1) has been carried out to further define the mechanism of catalysis, activation by divalent cations, and inhibition by toxins and inhibitory proteins. Mutation of active site residues predicted to bind metals (N124D and H248N) resul...

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

authors： Huang HB,Horiuchi A,Goldberg J,Greengard P,Nairn AC

更新日期：1997-04-15 00:00:00

abstract：:Although biological cells are mostly transparent, they are phase objects that differ in shape and refractive index. Any image that is projected through layers of randomly oriented cells will normally be distorted by refraction, reflection, and scattering. Counterintuitively, the retina of the vertebrate eye is inverte...

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

authors： Franze K,Grosche J,Skatchkov SN,Schinkinger S,Foja C,Schild D,Uckermann O,Travis K,Reichenbach A,Guck J

更新日期：2007-05-15 00:00:00

abstract：:The rpoN gene encoding the transcription factor sigma54 in Myxococcus xanthus has been cloned using a heterologous rpoN probe. The sequence of the cross-hybridizing DNA confirmed the existence of an ORF 1518 bp long that encodes a well conserved member of the sigma54 family of sigma factors. Low- as well as high-strin...

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

authors： Keseler IM,Kaiser D

更新日期：1997-03-04 00:00:00

abstract：:We used electron cryotomography and subtomogram averaging to determine the in situ structures of mitochondrial ATP synthase dimers from two organisms belonging to the phylum euglenozoa: Trypanosoma brucei, a lethal human parasite, and Euglena gracilis, a photosynthetic protist. At a resolution of 32.5 Å and 27.5 Å, re...

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

authors： Mühleip AW,Dewar CE,Schnaufer A,Kühlbrandt W,Davies KM

更新日期：2017-01-31 00:00:00