Ribonucleotide reduction is a cytosolic process in mammalian cells independently of DNA damage.

abstract：:The monoclonal antibodies (mAb) DA6.147, DA6.164, and HIG.48 against human Ia antigens, but not the W6/32 mAb against human class I major histocompatibility complex antigens or the anti-monocyte OKM1 and 63D3 mAb, stimulated monocytes to secrete interleukin 1 (IL-1). IL-1 was measured by its property of promoting the ...

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

authors： Palacios R

更新日期：1985-10-01 00:00:00

abstract：:Mitochondrial dysfunction is implicated in the pathophysiology of Parkinson's disease (PD), a common age-associated neurodegenerative disease characterized by intraneuronal inclusions (Lewy bodies) and progressive degeneration of the nigrostriatal dopamine (DA) system. It has recently been demonstrated that midbrain D...

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

authors： Ekstrand MI,Terzioglu M,Galter D,Zhu S,Hofstetter C,Lindqvist E,Thams S,Bergstrand A,Hansson FS,Trifunovic A,Hoffer B,Cullheim S,Mohammed AH,Olson L,Larsson NG

更新日期：2007-01-23 00:00:00

abstract：:Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation of ...

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

authors： Whiting JL,Ogier L,Forbush KA,Bucko P,Gopalan J,Seternes OM,Langeberg LK,Scott JD

更新日期：2016-07-26 00:00:00

abstract：:Energetics of resting and evoked fMRI signals were related to localized ensemble firing rates (nu) measured by electrophysiology in rats. Two different unstimulated, or baseline, states were established by anesthesia. Halothane and alpha-chloralose established baseline states of high and low energy, respectively, in w...

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

authors： Maandag NJ,Coman D,Sanganahalli BG,Herman P,Smith AJ,Blumenfeld H,Shulman RG,Hyder F

更新日期：2007-12-18 00:00:00

abstract：:A general theory of the structure of complexes of the transition metals is developed on the basis of the enneacovalence of the metals and the requirements of the electroneutrality principle. An extra orbital may be provided through the small but not negligible amount of f and g character of spd bond orbitals, and an e...

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

authors： Pauling L

更新日期：1977-12-01 00:00:00

abstract：:China has experienced rapid urbanization and dramatic economic growth since its reform process started in late 1978. In this article, we present evidence for a significant urbanization effect on climate based on analysis of impacts of land-use changes on surface temperature in southeast China, where rapid urbanization...

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

authors： Zhou L,Dickinson RE,Tian Y,Fang J,Li Q,Kaufmann RK,Tucker CJ,Myneni RB

更新日期：2004-06-29 00:00:00

abstract：:Induced pluripotent stem cells (iPS cells) represent a unique tool for the study of the pathophysiology of human disease, because these cells can be differentiated into multiple cell types in vitro and used to generate patient- and tissue-specific disease models. Given the critical role for skeletal muscle insulin res...

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

authors： Iovino S,Burkart AM,Warren L,Patti ME,Kahn CR

更新日期：2016-02-16 00:00:00

abstract：:Antischizophrenic neuroleptic drugs of the diphenylbutylpiperidine class, which includes pimozide, fluspirilene, penfluridol, and clopimozide, inhibit [3H]nitrendipine binding with IC50 values of 13-30 nM. This inhibition involves receptors for the verapamil/prenylamine class of calcium channel antagonists. These diph...

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

authors： Gould RJ,Murphy KM,Reynolds IJ,Snyder SH

更新日期：1983-08-01 00:00:00

abstract：:Physical and gene mapping studies reveal that chloroplast DNA from geranium (Pelargonium hortorum) has sustained a number of extensive duplications and inversions, resulting in a genome arrangement radically unlike that of other plants. At 217 kilobases in size, the circular chromosome is about 50% larger than the typ...

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

authors： Palmer JD,Nugent JM,Herbon LA

更新日期：1987-02-01 00:00:00

abstract：:Intact squid axons were injected with aequorin and bathed in 3 mM Ca seawater (a concentration close to that of squid blood). Sodium and potassium currents were pharmacologically blocked and repetitive voltage-clamp pulses of a duration of 1.5 ms were applied (to simulate the duration of an action potential) at amplit...

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

authors： Mullins LJ,Requena J,Whittembury J

更新日期：1985-03-01 00:00:00

abstract：:EcoRI endonuclease-generated DNA fragments carrying replication regions of the F'lac and R6-5 plasmids have been cloned and isolated, using as a selection vehicle a nonreplicating ampicillin-resistance DNA fragment derived from a Staphylococcus aureus plasmid. Heteroduplex analysis of the constructed plasmid chimeras ...

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

authors： Timmis K,Cabello F,Cohen SN

更新日期：1975-06-01 00:00:00

abstract：:Injury to the peripheral processes produces a profound cell loss (40-50%) in the dorsal root ganglion of newborn rats. Although division of central processes produces little or no cellular change in sensory ganglion of adult animals, no information has been available on the effect of dorsal root section in developing ...

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

authors： Yip HK,Johnson EM Jr

更新日期：1984-10-01 00:00:00

abstract：:Solar emission produces copious nitrosonium ions (NO(+)) in the D layer of the ionosphere, 60 to 90 km above the Earth's surface. NO(+) is believed to transfer its charge to water clusters in that region, leading to the formation of gaseous nitrous acid (HONO) and protonated water cluster. The dynamics of this reactio...

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

authors： He R,Li L,Zhong J,Zhu C,Francisco JS,Zeng XC

更新日期：2016-04-26 00:00:00

abstract：:Ca2+ ions control the cGMP-gated channel of rod photoreceptor cells from the external and internal face. We studied ion selectivity and blockage by Ca2+ of wild-type and mutant channels in a heterologous expression system. External Ca2+ blocks the inward current at micromolar concentrations in a highly voltage-depende...

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

authors： Eismann E,Müller F,Heinemann SH,Kaupp UB

更新日期：1994-02-01 00:00:00

abstract：:The Arabidopsis thaliana SOS1 protein is a putative Na+/H+ antiporter that functions in Na+ extrusion and is essential for the NaCl tolerance of plants. sos1 mutant plants share phenotypic similarities with mutants lacking the protein kinase SOS2 and the Ca2+ sensor SOS3. To investigate whether the three SOS proteins ...

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

authors： Quintero FJ,Ohta M,Shi H,Zhu JK,Pardo JM

更新日期：2002-06-25 00:00:00

abstract：:In solid-state physics, "doping" is a pivotal concept that allows controlling and engineering of the macroscopic electronic and optical properties of materials such as semiconductors by judiciously introducing small concentrations of impurities. Recently, this concept has been translated to two-dimensional photonic sc...

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

authors： Coppolaro M,Moccia M,Castaldi G,Engheta N,Galdi V

更新日期：2020-06-23 00:00:00

abstract：:Allosteric regulation of oxygen delivery by RBCs may have significant effects on tumor growth. Indeed, angiogenesis, the formation of new blood vessels, is induced in growing tumors by low oxygen partial pressure. Hypoxia-inducible genes are switched on, among which are the VEGF gene and its receptors. Most important,...

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

authors： Kieda C,Greferath R,Crola da Silva C,Fylaktakidou KC,Lehn JM,Nicolau C

更新日期：2006-10-17 00:00:00

abstract：:Despite the importance of mitotic cell rounding in tissue development and cell proliferation, there remains a paucity of approaches to investigate the mechanical robustness of cell rounding. Here we introduce ion beam-sculpted microcantilevers that enable precise force-feedback-controlled confinement of single cells w...

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

authors： Cattin CJ,Düggelin M,Martinez-Martin D,Gerber C,Müller DJ,Stewart MP

更新日期：2015-09-08 00:00:00

abstract：:A diploid strain of yeast (Saccharomyces cerevisiae) was found to be heterozygous for two forms of the highly repetitious ribosomal DNA. These forms could be distinguished by the pattern of fragments produced after digestion with the site-specific restriction endonuclease EcoRI. The mode of inheritance of ribosomal DN...

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

authors： Petes TD,Botstein D

更新日期：1977-11-01 00:00:00

abstract：:The catalytic cycle of the ATP/Mg(2+)-dependent enzyme beta-lactam synthetase (beta-LS) from Streptomyces clavuligerus has been observed through a series of x-ray crystallographic snapshots. Chemistry is initiated by the ordered binding of ATP/Mg(2+) and N(2)-(carboxyethyl)-l-arginine (CEA) to the apoenzyme. The apo a...

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

authors： Miller MT,Bachmann BO,Townsend CA,Rosenzweig AC

更新日期：2002-11-12 00:00:00

abstract：:Chronic stress is known to promote inflammatory bowel disease (IBD), but the underlying mechanism remains largely unresolved. Here, we found chronic stress to sensitize mice to dextran sulfate sodium (DSS)-induced colitis; to increase the infiltration of B cells, neutrophils, and proinflammatory ly6Chi macrophages in ...

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

authors： Gao X,Cao Q,Cheng Y,Zhao D,Wang Z,Yang H,Wu Q,You L,Wang Y,Lin Y,Li X,Wang Y,Bian JS,Sun D,Kong L,Birnbaumer L,Yang Y

更新日期：2018-03-27 00:00:00

abstract：:Human appropriation of net primary production (HANPP), the aggregate impact of land use on biomass available each year in ecosystems, is a prominent measure of the human domination of the biosphere. We present a comprehensive assessment of global HANPP based on vegetation modeling, agricultural and forestry statistics...

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

authors： Haberl H,Erb KH,Krausmann F,Gaube V,Bondeau A,Plutzar C,Gingrich S,Lucht W,Fischer-Kowalski M

更新日期：2007-07-31 00:00:00

abstract：:The three-dimensional structures of RNA enzymes form catalytic centers that include specific substrate binding sites. High-resolution determination of these and other RNA structures is essential for a detailed understanding of the function of RNA in biological systems. The crystal structures of only a few RNA molecule...

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

authors： Doudna JA,Grosshans C,Gooding A,Kundrot CE

更新日期：1993-08-15 00:00:00

abstract：:The functions of individual basal transcription factors during the formation of an initiation complex by RNA polymerase II remain largely unknown. Transcription factor IIE (TFIIE) has recently been shown to bind to multiple targets in the initiation complex. To assess the role of zinc binding in basal transcription, w...

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

authors： Maxon ME,Tjian R

更新日期：1994-09-27 00:00:00

abstract：:In a recent article, Hunter uses the late George Varley and George Gradwell's long-term data on the winter moth (Operophtera brumata) and green tortrix (Tortrix viridana) populations to propose a method of quantifying the relative importance of top-down effects (because of natural enemies) and bottom-up effects (becau...

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

authors： Hassell MP,Crawley MJ,Godfray HC,Lawton JH

更新日期：1998-09-01 00:00:00

abstract：:The hippocampus has a well-documented role for spatial navigation across species, but its role for spatial memory in nonnavigational tasks is uncertain. In particular, when monkeys are tested in tasks that do not require navigation, spatial memory seems unaffected by lesions of the hippocampus. However, the interpreta...

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

authors： Forcelli PA,Palchik G,Leath T,DesJardin JT,Gale K,Malkova L

更新日期：2014-03-18 00:00:00

abstract：:Epigenetics regulation plays a critical role in determining cell identity by controlling the accessibility of lineage-specific regulatory regions. In muscle stem cells, epigenetic mechanisms of how chromatin accessibility is modulated during cell fate determination are not fully understood. Here, we identified a long ...

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

authors： Dong A,Preusch CB,So WK,Lin K,Luan S,Yi R,Wong JW,Wu Z,Cheung TH

更新日期：2020-12-22 00:00:00

abstract：:The sparking of cut grape hemispheres in a household microwave oven has been a poorly explained Internet parlor trick for over two decades. By expanding this phenomenon to whole spherical dimers of various grape-sized fruit and hydrogel water beads, we demonstrate that the formation of plasma is due to electromagnetic...

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

authors： Khattak HK,Bianucci P,Slepkov AD

更新日期：2019-03-05 00:00:00

abstract：:The yeast auxiliary transcription factor GAL11, a candidate for the coactivator, was partially purified from yeast cells, and its function was characterized in a cell-free transcription system. The partially purified GAL11 protein stimulated basal transcription from the CYC1 core promoter by a factor of 4-5 at the ste...

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

authors： Sakurai H,Hiraoka Y,Fukasawa T

更新日期：1993-09-15 00:00:00

abstract：:The saturation values for ribosomal RNA hybridization have been determined for DNA from diploid and polytene tissues of Drosophila melanogaster. These values have been measured in XO and XX larvae which have, respectively, one and two nucleolus organizers in the diploid chromosome set. The results show that (1) in dip...

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

authors： Spear BB,Gall JG

更新日期：1973-05-01 00:00:00