Abstract:
:Trial electron density functions have some conceptual and computational advantages over wave functions. The properties of some simple density functions for H(+) (2) and H(2) are examined. It appears that for a diatomic molecule a good density function would be given by rho = N(A(2) + B(2)), in which A and B are short sums of s, p, d, etc. orbitals centered on each nucleus. Some examples are also given for electron densities that are appropriate for excited states.
journal_name
Proc Natl Acad Sci U S Aauthors
Pearson RG,Palke WEdoi
10.1073/pnas.77.4.1725subject
Has Abstractpub_date
1980-04-01 00:00:00pages
1725-7issue
4eissn
0027-8424issn
1091-6490journal_volume
77pub_type
杂志文章abstract::Arteriovenous (AV) malformation (AVM) is a devastating condition characterized by focal lesions of enlarged, tangled vessels that shunt blood from arteries directly to veins. AVMs can form anywhere in the body and can cause debilitating ischemia and life-threatening hemorrhagic stroke. The mechanisms that underlie AVM...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1415316111
更新日期:2014-12-16 00:00:00
abstract::Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathogenesis of obesity-driven type 2 diabetes mellitus and associated cardiovascular complications. Here, we show that perturbation of caveolar microdomains leads to insulin resistance and concomitant up-regulation of PAI-1 in 3T3L1 adipocytes. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0405278101
更新日期:2004-12-07 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
pub_type: 杂志文章
doi:10.1073/pnas.94.25.13816
更新日期:1997-12-09 00:00:00
abstract::A major challenge of cancer immunotherapy is the persistence and outgrowth of subpopulations that lose expression of the target antigen. IL-15 is a potent cytokine that can promote organ-specific autoimmunity when up-regulated on tissue cells. Here we report that T cells eradicated 2-wk-old solid tumors that expressed...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1301022110
更新日期:2013-05-14 00:00:00
abstract::In contrast to observations in bacteria and fungi, frameshift mutations in bacteriophage T4 do not arise during genetic recombination. Nascent mutants, captured in the heterozygous condition, exhibit properties which indicate that the new lesions are located at the extreme tips of the chromosomes, and are segregated b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.65.3.617
更新日期:1970-03-01 00:00:00
abstract::Pancreatic ductal adenocarcinoma (PDAC) is characterized by the presence of abundant desmoplastic stroma primarily composed of cancer-associated fibroblasts (CAFs). It is generally accepted that CAFs stimulate tumor progression and might be implicated in drug resistance and immunosuppression. Here, we have compared th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1717802115
更新日期:2018-02-06 00:00:00
abstract::Poliovirus RNA polymerase requires a host factor to initiate RNA synthesis in vitro. The host factor was previously purified to near homogeneity from HeLa cells but was not assigned an enzymatic activity. This report describes the purification of a terminal uridylyltransferase that can act as host factor. By all crite...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.2.221
更新日期:1986-01-01 00:00:00
abstract::"Functional connectivity" techniques are commonplace tools for studying brain organization. A critical element of these analyses is to distinguish variance due to neurobiological signals from variance due to nonneurobiological signals. Multiecho fMRI techniques are a promising means for making such distinctions based ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1720985115
更新日期:2018-02-27 00:00:00
abstract::Rat liver nuclei pure by enzymatic and electron microscope criteria contain protein kinase C (PKC) that can be activated several hundredfold within 3 min of addition of prolactin or phorbol 12-tetradecanoate 13-acetate. Rat prolactin stimulated PKC maximally at 10(-12) M, whereas ovine prolactin was maximally stimulat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.22.8649
更新日期:1988-11-01 00:00:00
abstract::Iron-sulfur (Fe-S) proteins are key players in vital processes involving energy homeostasis and metabolism from the simplest to most complex organisms. We report a 1.5 A x-ray crystal structure of the first identified outer mitochondrial membrane Fe-S protein, mitoNEET. Two protomers intertwine to form a unique dimeri...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0707189104
更新日期:2007-09-04 00:00:00
abstract::The supernatant fluid (conditioned medium) of cultured human vascular endothelial cells inhibits activation of Hageman factor (factor XII), whether by ellagic acid, bovine brain sulfatides, or bismuth subgallate; inhibition appears to be a property of one or more proteins in the culture supernates. This phenomenon may...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.23.10740
更新日期:1991-12-01 00:00:00
abstract::The dramatic loss of Kilimanjaro's ice cover has attracted global attention. The three remaining ice fields on the plateau and the slopes are both shrinking laterally and rapidly thinning. Summit ice cover (areal extent) decreased approximately 1% per year from 1912 to 1953 and approximately 2.5% per year from 1989 to...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0906029106
更新日期:2009-11-24 00:00:00
abstract::The DNA binding activity of p53 is crucial for its tumor suppressor function and is subject to tight regulation. Previous studies revealed that the inhibitory function of the p53 C terminus is implicated in the latent, low affinity sequence-specific DNA binding activity of p53 in the uninduced state. Sequence-specific...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.11.6079
更新日期:1998-05-26 00:00:00
abstract::The nucleotide-binding domain and leucine-rich repeats containing proteins (NLRs) serve as immune receptors in both plants and animals. Overaccumulation of NLRs often leads to autoimmune responses, suggesting that the levels of these immune receptors must be tightly controlled. However, the mechanism by which NLR prot...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1105685108
更新日期:2011-08-30 00:00:00
abstract::Neuropathogenicity of poliovirus can be attenuated by mutations in the internal ribosomal entry site (IRES) within the 5' nontranslated region of its genome. The Sabin vaccine strains used in prevention of poliomyelitis carry such mutations in their IRES elements. In addition, mutations within the structural and nonst...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.6.2370
更新日期:1996-03-19 00:00:00
abstract::Molecular oxygen (O(2)) began to accumulate in the atmosphere and surface ocean ca. 2,400 million years ago (Ma), but the persistent oxygenation of water masses throughout the oceans developed much later, perhaps beginning as recently as 580-550 Ma. For much of the intervening interval, moderately oxic surface waters ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0909248106
更新日期:2009-10-06 00:00:00
abstract::From 1980 to 1992, a series of influential papers reported on the discovery, genetics, and evolution of a periodic cycling of the interval between Drosophila male courtship song pulses. The molecular mechanisms underlying this periodicity were never described. To reinitiate investigation of this phenomenon, we previou...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1707471114
更新日期:2017-09-12 00:00:00
abstract::Photoreceptors of the Xenopus laevis retina are the site of a circadian clock. As part of a differential display screen for rhythmic gene products in this system, we have identified a photoreceptor-specific mRNA expressed in peak abundance at night. cDNA cloning revealed an open reading frame encoding a putative 388 a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 评论,杂志文章
doi:10.1073/pnas.93.25.14884
更新日期:1996-12-10 00:00:00
abstract::Expression of amino acid biosynthesis genes in bacteria is often repressed when abundant supplies of the cognate amino acid are available. Repression of the Bacillus subtilis lysC gene by lysine was previously shown to occur at the level of premature termination of transcription. In this study we show that lysine dire...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2133705100
更新日期:2003-10-14 00:00:00
abstract::EF-hand Ca(II) binding sites share a conserved architecture and are prevalent in Ca(II) signaling pathways. The ion binding kinetics of these sites are carefully tuned to provide the physiologically appropriate activation and inactivation time scales. Here we examine kinetic tuning by the side chain at the ninth posit...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.14.6493
更新日期:1993-07-15 00:00:00
abstract::The signal recognition particle (SRP) is a ribonucleoprotein composed of an Alu domain and an S domain. The S domain contains unique sequence SRP RNA and four SRP proteins: SRP19, SRP54, SRP68, and SRP72. SRP interacts with ribosomes to bring translating membrane and secreted proteins to the endoplasmic reticulum (ER)...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.97.1.55
更新日期:2000-01-04 00:00:00
abstract::Plant soil specialists contribute greatly to global diversity; however, the ecoevolutionary forces responsible for generating this diversity are poorly understood. We integrate molecular phylogenies with descriptive and experimental ecological data, creating a powerful framework with which to elucidate forces driving ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1409242111
更新日期:2014-10-21 00:00:00
abstract::Apolipoprotein L-1 (APOL1), the trypanolytic factor of human serum, can lyse several African trypanosome species including Trypanosoma brucei brucei, but not the human-infective pathogens T. brucei rhodesiense and T. brucei gambiense, which are resistant to lysis by human serum. Lysis follows the uptake of APOL1 into ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1421953112
更新日期:2015-03-03 00:00:00
abstract::Hypercholesterolemia, high serum cholesterol in the form of LDL, is a major risk factor for atherosclerosis. LDL is mostly degraded in the liver after its cellular internalization with the LDL receptor (LDLR). This clathrin-mediated endocytosis depends on the protein autosomal recessive hypercholesterolemia (ARH), whi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1114128109
更新日期:2012-05-01 00:00:00
abstract::The effect of human papillomavirus (HPV) and activated oncogenes on the growth and morphology of primary baby mouse kidney (BMK) cells has been studied. Early region DNA from HPV types 16, 18, 31, and 33, but not type 6, under the transcriptional control of a heterologous, retroviral promoter cooperated with EJ-ras to...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.23.8820
更新日期:1988-12-01 00:00:00
abstract::Activation of the MEK/ERK/Elk-signaling cascade is a mechanism for relaying mitogenic and stress stimuli for gene activation. MEK1 is the proximate kinase for activation of ERK1/2, and nuclear targeting of ERK1/2 is obligatory for Elk1 transcriptional activity. Human biliverdin reductase (hBVR) is a recently described...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0800750105
更新日期:2008-05-13 00:00:00
abstract::Estrogens control many physiological and behavioral processes, some of which are connected to reproduction. These include sexual and other social behaviors. Here we implicate four gene products in a micronet required for mammalian social recognition, through which an individual learns to recognize other individuals. F...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0631699100
更新日期:2003-05-13 00:00:00
abstract::The major cell surface glycoconjugate of Leishmania major, a putative parasite receptor for macrophages, is a lipophosphoglycan containing 81.6% (wt/wt) carbohydrate, 17.0% (wt/wt) phosphate, and 1.4% (wt/wt) lipid. It has been purified to homogeneity by hydrophobic chromatography and consists of a polydisperse family...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.24.8941
更新日期:1987-12-01 00:00:00
abstract::In pulmonary arterial hypertension (PAH), antiapoptotic, proliferative, and inflammatory diatheses converge to create an obstructive vasculopathy. A selective down-regulation of the Kv channel Kv1.5 has been described in human and animal PAH. The resultant increase in intracellular free Ca(2+) ([Ca(2+)](i)) and K(+) (...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0610467104
更新日期:2007-07-03 00:00:00
abstract::[3H]Puromycin and N-(ethyl-2-diazomalonyl)[3H]puromycin are incorporated into E. coli ribosomes on irradiation at 253.7 nm. Both compounds incorporate into both protein and nucleic acid. Two-dimensional gel electrophoresis of ribosomal protein shows that L23 is the major protein labeled by puromycin. Although incorpor...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.8.2974
更新日期:1975-08-01 00:00:00