Higher-order syzygies for the bracket algebra and for the ring of coordinates of the Grassmanian.

abstract：:The IgG2a monoclonal antibody TH-1, which reacts specifically with blood group A1 but with neither A2 nor O erythrocytes, has been established. The antibody reacted only with A1 erythrocytes in hemagglutination and antibody absorption assays; it did not react with A2 erythrocytes, even after trypsin or sialidase treat...

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

authors： Clausen H,Levery SB,Nudelman E,Tsuchiya S,Hakomori S

更新日期：1985-02-01 00:00:00

abstract：:The robustness of eight common food web properties is examined with respect to web size. We show that the current controversy concerning the scale dependence or scale invariance of these properties can be resolved by accounting for scaling constraints introduced by webs of very small size. We demonstrate statistically...

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

authors： Bersier LF,Sugihara G

更新日期：1997-02-18 00:00:00

abstract：:Fetal cells, potentially usable for prenatal diagnosis, were sorted from maternal blood samples taken as early as 15 weeks of gestation. Immunogenetic and cytogenic criteria established the fetal origin of the observed cells: Y-chromatin-containing (male) cells were detected in the sorted sample if and only if the new...

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

authors： Herzenberg LA,Bianchi DW,Schröder J,Cann HM,Iverson GM

更新日期：1979-03-01 00:00:00

abstract：:AIDS remains incurable due to the permanent integration of HIV-1 into the host genome, imparting risk of viral reactivation even after antiretroviral therapy. New strategies are needed to ablate the viral genome from latently infected cells, because current methods are too inefficient and prone to adverse off-target e...

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

authors： Hu W,Kaminski R,Yang F,Zhang Y,Cosentino L,Li F,Luo B,Alvarez-Carbonell D,Garcia-Mesa Y,Karn J,Mo X,Khalili K

更新日期：2014-08-05 00:00:00

abstract：:Guanosine tetraphosphate, recently discovered to mediate the regulatory relationship between protein synthesis and RNA accumulation in various bacteria, has been synthesized in vitro in large quantities and analyzed by natural-abundance (13)C nuclear magnetic resonance spectroscopy in order to confirm its structure an...

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

authors： Que L Jr,Willie GR,Cashel M,Bodley JW,Gray GR

更新日期：1973-09-01 00:00:00

abstract：:Synchrotron far-IR spectroscopy and density-functional calculations are used to characterize the low-frequency dynamics of model heme FeCO compounds. The "doming" vibrational mode in which the iron atom moves out of the porphyrin plane while the periphery of this ring moves in the opposite direction determines the rea...

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

authors： Klug DD,Zgierski MZ,Tse JS,Liu Z,Kincaid JR,Czarnecki K,Hemley RJ

更新日期：2002-10-01 00:00:00

abstract：:Global activation of the embryonic genome is the most critical event in early mammalian development. After fertilization, a rich supply of maternal proteins and RNAs support development whereas a number of zygotic and embryonic genes are expressed in a stage-specific manner leading to embryonic genome activation (EGA)...

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

authors： Misirlioglu M,Page GP,Sagirkaya H,Kaya A,Parrish JJ,First NL,Memili E

更新日期：2006-12-12 00:00:00

abstract：:Carbon nanotube (CNT) membranes were employed as the active element of a switchable transdermal drug delivery device that can facilitate more effective treatments of drug abuse and addiction. Due to the dramatically fast flow through CNT cores, high charge density, and small pore dimensions, highly efficient electroph...

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

authors： Wu J,Paudel KS,Strasinger C,Hammell D,Stinchcomb AL,Hinds BJ

更新日期：2010-06-29 00:00:00

abstract：:Ascorbate (vitamin C) recycling occurs when extracellular ascorbate is oxidized, transported as dehydroascorbic acid, and reduced intracellularly to ascorbate. We investigated microorganism induction of ascorbate recycling in human neutrophils and in microorganisms themselves. Ascorbate recycling was determined by mea...

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

authors： Wang Y,Russo TA,Kwon O,Chanock S,Rumsey SC,Levine M

更新日期：1997-12-09 00:00:00

abstract：:Exposure of Chinese hamster cells to reduced oxygen partial pressure results in a marked enhancement in the frequency of methotrexate resistance and dihydrofolate reductase gene amplification. The frequency of enhanced resistance is a function of the length of exposure to hypoxic conditions and the time after recovery...

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

authors： Rice GC,Hoy C,Schimke RT

更新日期：1986-08-01 00:00:00

abstract：:The study of photoinitiated electron transfer in donor-bridge-acceptor molecules has helped elucidate the distance dependence of electron transfer rates and behavior of various electron transfer mechanisms. In all reported cases, the energies of the bridge electronic states involved in the electron transfer change dra...

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

authors： Goldsmith RH,Sinks LE,Kelley RF,Betzen LJ,Liu W,Weiss EA,Ratner MA,Wasielewski MR

更新日期：2005-03-08 00:00:00

abstract：:Some of the most important impacts of global climate change will be felt among the populations, predominantly in developing countries, referred to as "subsistence" or "smallholder" farmers. Their vulnerability to climate change comes both from being predominantly located in the tropics, and from various socioeconomic,...

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

authors： Morton JF

更新日期：2007-12-11 00:00:00

abstract：:We present a theory, and its computer implementation, of how mental simulations underlie the abductions of informal algorithms and deductions from these algorithms. Three experiments tested the theory's predictions, using an environment of a single railway track and a siding. This environment is akin to a universal Tu...

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

authors： Khemlani SS,Mackiewicz R,Bucciarelli M,Johnson-Laird PN

更新日期：2013-10-15 00:00:00

abstract：:The size of an organism reflects its metabolic rate, growth rate, mortality, and other important characteristics; therefore, the distribution of body size is a major determinant of ecosystem structure and function. Body-size distributions often are multimodal, with several peaks of abundant sizes, and previous studies...

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

authors： Lampert A,Tlusty T

更新日期：2013-01-02 00:00:00

abstract：:The C terminus of transcription factor NusA from Escherichia coli comprises two repeat units, which bind during antitermination to protein N from phage lambda. To delineate the structural basis of the NusA-lambdaN interaction, we attempted to crystallize the NusA C-terminal repeats in complex with a lambdaN peptide (r...

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

authors： Bonin I,Mühlberger R,Bourenkov GP,Huber R,Bacher A,Richter G,Wahl MC

更新日期：2004-09-21 00:00:00

abstract：:Two regioisomers with C3 or D3 symmetry of water-soluble carboxylic acid C60 derivatives, containing three malonic acid groups per molecule, were synthesized and found to be equipotent free radical scavengers in solution as assessed by EPR analysis. Both compounds also inhibited the excitotoxic death of cultured corti...

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

authors： Dugan LL,Turetsky DM,Du C,Lobner D,Wheeler M,Almli CR,Shen CK,Luh TY,Choi DW,Lin TS

更新日期：1997-08-19 00:00:00

abstract：:The understanding of mechanisms controlling zinc absorption and metabolism at the molecular level has advanced recently. Kinetics of zinc transport have been investigated for many years, but only recently have genes coding for proteins thought to be involved in the transport process been cloned. Four putative zinc tra...

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

authors： McMahon RJ,Cousins RJ

更新日期：1998-04-28 00:00:00

abstract：:Intrinsically disordered proteins (IDPs) are characterized by a lack of defined structure. Instead, they populate ensembles of rapidly interconverting conformations with marginal structural stabilities. Changes in solution conditions such as temperature and crowding agents consequently affect IDPs more than their fold...

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

authors： Wicky BIM,Shammas SL,Clarke J

更新日期：2017-09-12 00:00:00

abstract：:Pronounced bright and dark bands are seen at the bright and dark edges of half-shadows and similar distributions of illumination. These are the so-called Mach bands. A pair of vertical Mach bands was generated with a ramp pattern in the central strip of a horizontal tripartite oscilloscope display. This pattern consis...

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

authors： Ratliff F,Milkman N,Rennert N

更新日期：1983-07-01 00:00:00

abstract：:The hypothesis that intracellular Ca2+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca2+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulat...

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

authors： Pershadsingh HA,Shade DL,Delfert DM,McDonald JM

更新日期：1987-02-01 00:00:00

abstract：:Discrete growing spiral modes are calculated, on the basis of principles of stellar dynamics, according to the recently developed asymptotic theory of density waves for spiral structure in galaxies. From the growth rates obtained, it appears likely that several spiral modes coexist in a given disk galaxy. General prop...

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

authors： Bertin G,Lau YY,Lin CC,Mark JW,Sugiyama L

更新日期：1977-11-01 00:00:00

abstract：:CPEB, a cytoplasmic polyadenylation element-binding protein, plays an important role in translational control of maternal mRNAs in early animal development. During Xenopus oocyte maturation, CPEB undergoes a Cdc2-mediated phosphorylation- and ubiquitin-dependent degradation that is required for proper entry into meios...

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

authors： Setoyama D,Yamashita M,Sagata N

更新日期：2007-11-13 00:00:00

abstract：:Classical hypotheses regarding the evolutionary origin of paired appendages propose transformation of precursor structures (gill arches and lateral fin folds) into paired fins. During development, gnathostome paired appendages form as outgrowths of body wall somatopleure, a tissue composed of somatic lateral plate mes...

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

authors： Tulenko FJ,McCauley DW,Mackenzie EL,Mazan S,Kuratani S,Sugahara F,Kusakabe R,Burke AC

更新日期：2013-07-16 00:00:00

abstract：:Tauopathies are a class of neurodegenerative diseases associated with pathological tau. Despite many advances in our understanding of these diseases, the direct mechanism through which tau contributes to neurodegeneration remains poorly understood. Previously, our laboratory implicated the histone demethylase LSD1 in ...

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

authors： Engstrom AK,Walker AC,Moudgal RA,Myrick DA,Kyle SM,Bai Y,Rowley MJ,Katz DJ

更新日期：2020-11-17 00:00:00

abstract：:We analyzed variability in outer surface protein B (OspB) from Borrelia burgdorferi (Bb), the causative agent of Lyme disease, to determine how Bb escapes immune destruction. We have shown that vaccination with OspB from Bb strain B31 protected mice from infection with Bb B31 but not against Bb N40. The present study ...

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

authors： Fikrig E,Tao H,Kantor FS,Barthold SW,Flavell RA

更新日期：1993-05-01 00:00:00

abstract：:The atomic displacements associated with the freezing of metals and salts are calculated by treating crystal growth as an assignment problem through the use of an optimal transport algorithm. Converting these displacements into timescales based on the dynamics of the bulk liquid, we show that we can predict the activa...

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

authors： Sun G,Hawken A,Harrowell P

更新日期：2020-02-18 00:00:00

abstract：:Sulfolobus turreted icosahedral virus (STIV) was isolated in acidic hot springs where it infects the archeon Sulfolobus solfataricus. We determined the STIV structure using near-atomic resolution electron microscopy and X-ray crystallography allowing tracing of structural polypeptide chains and visualization of transm...

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

authors： Veesler D,Ng TS,Sendamarai AK,Eilers BJ,Lawrence CM,Lok SM,Young MJ,Johnson JE,Fu CY

更新日期：2013-04-02 00:00:00

abstract：:We determined the crystal structure of the Escherichia coli nucleoid-associated HUalphabeta protein by x-ray diffraction and observed that the heterodimers form multimers with octameric units in three potential arrangements, which may serve specialized roles in different DNA transaction reactions. It is of special imp...

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

authors： Guo F,Adhya S

更新日期：2007-03-13 00:00:00

abstract：:Neural crest stem cells can be isolated from differentiated cultures of human pluripotent stem cells, but the process is inefficient and requires cell sorting to obtain a highly enriched population. No specific method for directed differentiation of human pluripotent cells toward neural crest stem cells has yet been r...

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

authors： Menendez L,Yatskievych TA,Antin PB,Dalton S

更新日期：2011-11-29 00:00:00

abstract：:Classical feed-forward inhibition involves an excitation-inhibition sequence that enhances the temporal precision of neuronal responses by narrowing the window for synaptic integration. In the input layer of the cerebellum, feed-forward inhibition is thought to preserve the temporal fidelity of granule cell spikes dur...

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

authors： Duguid I,Branco T,Chadderton P,Arlt C,Powell K,Häusser M

更新日期：2015-10-20 00:00:00