Abstract:
:DNA sequences in Neurospora crassa that code for ribosomal RNA have been isolated in a highly purified state by DNA-RNA hybridization. About 100 separate ribosomal RNA genes exist in each nucleus. These genes are composed of repeated sequences that are present about 100 times per nucleus. The individual members of this group of DNA sequences are essentially identical.
journal_name
Proc Natl Acad Sci U S Aauthors
Chattopadhyay SK,Kohne DE,Dutta SKdoi
10.1073/pnas.69.11.3256subject
Has Abstractpub_date
1972-11-01 00:00:00pages
3256-9issue
11eissn
0027-8424issn
1091-6490journal_volume
69pub_type
杂志文章abstract::The spread of bacteria resistant to antimicrobial agents calls for population-wide treatment strategies to delay or reverse the trend toward antibiotic resistance. Here we propose new criteria for the evaluation of the population-wide effects of treatment protocols for directly transmitted bacterial infections and dis...
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.94.22.12106
更新日期:1997-10-28 00:00:00
abstract::Degradable polymers are beginning to play an increasing role as materials for environmental and medical applications. Understanding factors that control erosion, such as bond cleavage and the dissolution and diffusion of degradation products, will be critical to the future development of these materials. Erosion kinet...
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.90.2.552
更新日期:1993-01-15 00:00:00
abstract::Molecular dynamics (MD) simulations provide essential information about the thermodynamics and dynamics of proteins. To construct the free-energy surface from equilibrium trajectories, it is necessary to group the individual snapshots in a meaningful way. The inherent structures (IS) are shown to provide an appropriat...
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.0915087107
更新日期:2010-05-18 00:00:00
abstract::Nociceptive information is modulated by a large number of endogenous signaling agents that change over the course of recovery from injury. This plasticity makes understanding regulatory mechanisms involved in descending inhibition of pain scientifically and clinically important. Neurons that synthesize the neuropeptid...
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.1306342110
更新日期:2013-08-06 00:00:00
abstract::Serological expression cloning of antigens eliciting a humoral immune response to a syngeneic mouse sarcoma identified pem (mouse placenta and embryonic expression gene) as a new member of the cancer/testis family. To identify the human homologue of pem, mouse pem sequences and pem-related expressed sequence tags from...
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.041625098
更新日期:2001-03-13 00:00:00
abstract::The subventricular zone remains mitotically active throughout life in rodents. Studies with tritiated thymidine, which is incorporated into the DNA of mitotic cells, have revealed that the rodent subventricular zone produces neuroblasts that migrate toward the olfactory bulb along the rostral migratory stream. A simil...
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.172403999
更新日期:2002-08-20 00:00:00
abstract::During neurogenesis of the mammalian neocortex, neural progenitor cells divide to generate daughter cells that either become neurons or remain as progenitor cells. The mouse numb (m-numb) gene encodes a membrane-associated protein that is asymmetrically localized to the apical cell membrane of dividing cortical progen...
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.97.12.6844
更新日期:2000-06-06 00:00:00
abstract::The tau and gamma subunits of DNA polymerase III holoenzyme are both products of the dnaX gene. Since tau and gamma are required as stoichiometric components of the replicative complex, a mechanism must exist for the cell to coordinate their synthesis and ensure that both subunits are present in an adequate quantity a...
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.87.10.3713
更新日期:1990-05-01 00:00:00
abstract::The feasibility of long-term information storage by brain type II Ca2+/calmodulin-dependent protein kinase molecules is explored. Recent evidence indicates that this protein has switch-like properties. Equations are derived showing that a single kinase holoenzyme could form a bistable switch having the stability neces...
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.85.14.5320
更新日期:1988-07-01 00:00:00
abstract::Various enzymatic derivatives of the murine myeloma protein IgA(MOPC-315) were subjected to hapten-binding quantitation and circular dichroic analysis in an attempt to ascertain the structural localization and functional definition of the immunoglobulin active site. The extrinsic Cotton effects observed with near satu...
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.71.5.1940
更新日期:1974-05-01 00:00:00
abstract::The envelope spike of HIV is one of the most highly N-glycosylated structures found in nature. However, despite extensive research revealing essential functional roles in infection and immune evasion, the chemical structures of the glycans on the native viral envelope glycoprotein gp120--as opposed to recombinantly ge...
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.1006498107
更新日期:2010-08-03 00:00:00
abstract::Interleukin 2 (IL-2) is a potent growth factor for T lymphocytes, playing a crucial role in the immune response. In view of the considerable evidence that the immunoregulatory cytokines (or lymphokines) also play a role in the growth and differentiation of cells in the central nervous system (CNS), we examined the ope...
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.87.17.6584
更新日期:1990-09-01 00:00:00
abstract::The localized maternal RNA Vg1 resides in the cortical region of the vegetal pole of fully grown Xenopus oocytes and is inherited by only a subset of blastomeres in the early embryo [Weeks, D. L. & Melton, D. A. (1987) Cell 51, 861-867]. Because RNA-cytoskeletal interactions may play a role in RNA localization, we hav...
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.85.20.7612
更新日期:1988-10-01 00:00:00
abstract::Whereas 234(92)U142 and other actinon nuclei have ground-state bands that indicate that each nucleus consists of a sphere and a single revolving cluster with constant composition and with only a steady increase in the moment of inertia with increase in J, the angular-momentum quantum number, many of the lanthanon grou...
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.88.3.820
更新日期:1991-02-01 00:00:00
abstract::The nitrogen isotopic composition (15N/14N) of forested ecosystems varies systematically worldwide. In tropical forests, which are elevated in 15N relative to temperate biomes, a decrease in ecosystem 15N/14N with increasing rainfall has been reported. This trend is seen in a set of well characterized Hawaiian rainfor...
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.0510185103
更新日期:2006-06-06 00:00:00
abstract::Cardiomyopathy (CM) is a primary degenerative disease of myocardium and is traditionally categorized into hypertrophic and dilated CMs (HCM and DCM) according to its gross appearance. Cardiomyopathic hamster (CM hamster), a representative model of human hereditary CM, has HCM and DCM inbred sublines, both of which des...
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.94.25.13873
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
pub_type: 杂志文章
doi:10.1073/pnas.83.16.5978
更新日期:1986-08-01 00:00:00
abstract::Diverse forms of injury and stress evoke a hypertrophic growth response in adult cardiac myocytes, which is characterized by an increase in cell size, enhanced protein synthesis, assembly of sarcomeres, and reactivation of fetal genes, often culminating in heart failure and sudden death. Given the emerging roles of mi...
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.0608791103
更新日期:2006-11-28 00:00:00
abstract::Tissues from rhesus monkeys were screened by PCR for the presence of sequences homologous to known adeno-associated virus (AAV) serotypes 1-6. DNA spanning entire rep-cap ORFs from two novel AAVs, called AAV7 and AAV8, were isolated. Sequence comparisons among these and previously described AAVs revealed the greatest ...
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.182412299
更新日期:2002-09-03 00:00:00
abstract::Performance on the visual paired-comparison task depends on the integrity of the hippocampal formation in humans, monkeys, and, for an analogous task, in rats. The present study sought additional evidence in healthy volunteers concerning the nature of this task. We found that performance on the visual paired-compariso...
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.220398097
更新日期:2000-10-24 00:00:00
abstract::Affinity-fractionated porcine heparin was randomly scissioned by chemical techniques to give hexasaccharides, octasaccharides, decasaccharides, and mucopolysaccharide fragments of approximately 14 residues and approximately 16 residues that were able to complex with the protease inhibitor. Direct measurements of the 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.78.2.829
更新日期:1981-02-01 00:00:00
abstract::Staphylococcus aureus is a major cause of community-acquired and nosocomial infections including the life-threatening conditions endocarditis, necrotizing pneumonia, necrotizing fasciitis, and septicemia. Toll-like receptor (TLR)-2, a membrane-bound microbial sensor, detects staphylococcal components, but macrophages ...
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.0904958106
更新日期:2009-08-04 00:00:00
abstract::Most proteins are in equilibrium with partially and globally unfolded conformations. In contrast, kinetically stable proteins (KSPs) are trapped by an energy barrier in a specific state, unable to transiently sample other conformations. Among many potential roles, it appears that kinetic stability (KS) is a feature us...
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.0705417104
更新日期:2007-10-30 00:00:00
abstract::Many studies have reported age-related changes in immune responses that could be due to alterations in lymphoid cell numbers or functions. Here we report the results of studies using immunofluorescent staining and in vitro assays of cellular function to compare the expression of cell surface antigens on lymphocytes fr...
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.84.21.7624
更新日期:1987-11-01 00:00:00
abstract::The opportunistic pathogen Candida albicans can undergo phenotypic switching between a benign, unicellular phenotype and an invasive, multicellular form that causes candidiasis. Increasingly, strains of Candida are becoming resistant to antifungal drugs, making the treatment of candidiasis difficult, especially in imm...
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.0906145106
更新日期:2009-11-17 00:00:00
abstract::Suspended aqueous aerosol droplets (<50 µm) are microreactors for many important atmospheric reactions. In droplets and other aquatic environments, pH is arguably the key parameter dictating chemical and biological processes. The nature of the droplet air/water interface has the potential to significantly alter drople...
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.1720488115
更新日期:2018-07-10 00:00:00
abstract::Nitroxyl anion (HNONO(-)), the one-electron reduced form of nitric oxide (NO), induces positive cardiac inotropy and selective venodilation in the normal in vivo circulation. Here we tested whether HNO/NO(-) augments systolic and diastolic function of failing hearts, and whether contrary to NO/nitrates such modulation...
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.0937302100
更新日期:2003-04-29 00:00:00
abstract::The mitochondrial DNA polymerase from Drosophila embryos lacks dNTP turnover activity. However, a potent 3'----5' exonuclease activity can be detected by a specific assay in which the exonuclease excises mispaired nucleotides at the 3' termini of primed synthetic and natural DNA templates. The excision of a mispaired ...
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.86.17.6469
更新日期:1989-09-01 00:00:00
abstract::Regulatory T (Treg) cells expressing the transcription factor Foxp3 play an important role in maintaining immune homeostasis. Chronic inflammation is associated with reduced Foxp3 expression, function, and loss of phenotypic stability. Previous studies have established the importance of TNF receptor 2 (TNFR2) in the g...
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.1909687116
更新日期:2019-10-22 00:00:00
abstract::The all-cis hexose D-allose, fed to hamster fibroblast cultures over 14-20 hr, brings about a striking down-regulation of hexose transport. This down-regulation by allose is inhibited by 2,4-dinitrophenol. By using D-[14C]allose and thin-layer chromatography, two types of products accumulated that have been identified...
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.88.4.1504
更新日期:1991-02-15 00:00:00