Abstract:
:Viral hepatitis is a disease of antiquity, but evidence for more than one etiologic agent has been recognized only since the 1940s, when two viruses (hepatitis A virus and hepatitis B virus) were thought to account for all disease. In the past 20 years, three additional hepatitis agents (hepatitis C virus, hepatitis D virus, and hepatitis E virus) have been discovered, and there is evidence for at least one additional virus. Each of the five recognized hepatitis viruses belongs to a different virus family, and each has a unique epidemiology. The medical impact of these viruses on society has been strongly influenced by changes in human ecology. This has resulted in some cases in diminished disease and in others in increases in the incidence of disease.
journal_name
Proc Natl Acad Sci U S Aauthors
Purcell RHdoi
10.1073/pnas.91.7.2401subject
Has Abstractpub_date
1994-03-29 00:00:00pages
2401-6issue
7eissn
0027-8424issn
1091-6490journal_volume
91pub_type
杂志文章,评审abstract::Electrophysiological and activity-dependent gene expression studies of birdsong have contributed to the understanding of the neural representation of natural sounds. However, we have limited knowledge about the overall spatial topography of song representation in the avian brain. Here, we adapt the noninvasive functio...
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.0611515104
更新日期:2007-06-19 00:00:00
abstract::Heat shock protein 90-alpha (Hsp90alpha) is an intracellular molecular chaperone. However, it can also be secreted with the underlying regulatory mechanism remaining far from clear. Here we show that the secreted Hsp90alpha is a C-terminal truncated form and its secretion is regulated by the C-terminal EEVD motif via ...
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.0908151106
更新日期:2009-12-15 00:00:00
abstract::In skeletal muscle, dihydropyridine receptors are functionally coupled to ryanodine receptors of the sarcoplasmic reticulum in triadic or diadic junctional complexes. In cardiac muscle direct physical or functional couplings have not been demonstrated. We have tested the hypothesis of functional coupling of L-type Ca2...
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.92.1.121
更新日期:1995-01-03 00:00:00
abstract::Bifidobacteria comprise a significant proportion of the human gut microbiota. Several bifidobacterial strains are currently used as therapeutic interventions, claiming various health benefits by acting as probiotics. However, the precise mechanisms by which they maintain habitation within their host and consequently p...
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.1115621109
更新日期:2012-02-07 00:00:00
abstract::The phosphorylation state of the Na,K-ATPase alpha subunit has been examined in 32P-labeled sciatic nerves of control and streptozotocin-treated diabetic rats. Intact nerves were challenged with protein kinase (PK) modulators and alpha-subunit 32P labeling was analyzed after immunoprecipitation. In control nerves, the...
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.91.13.6211
更新日期:1994-06-21 00:00:00
abstract::Clear-cut inherited Mendelian traits, such as familial adenomatous polyposis or hereditary nonpolyposis colorectal cancer, account for <4% of colorectal cancers. Another 20% of all colorectal cancers are thought to occur in individuals with a significant inherited multifactorial susceptibility to colorectal cancer tha...
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.0407187101
更新日期:2004-11-09 00:00:00
abstract::Gut microbial composition depends on different dietary habits just as health depends on microbial metabolism, but the association of microbiota with different diets in human populations has not yet been shown. In this work, we compared the fecal microbiota of European children (EU) and that of children from a rural Af...
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.1005963107
更新日期:2010-08-17 00:00:00
abstract::A7r5 smooth muscle (aorta) cells have a spontaneous electrical activity. Application of vasopressin produces a hyperpolarization accompanied by an interruption of the spontaneous activity, which is followed by a depolarization associated with a recovery of the spiking activity. Vasopressin action is produced by an act...
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.85.23.9365
更新日期:1988-12-01 00:00:00
abstract::Although common in birds, social monogamy, or pair-living, is rare among mammals because internal gestation and lactation in mammals makes it advantageous for males to seek additional mating opportunities. A number of hypotheses have been proposed to explain the evolution of social monogamy among mammals: as a male ma...
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.1307903110
更新日期:2013-08-13 00:00:00
abstract::Cubic cage compounds composed of Co-CN-Ru linkages have been prepared which illustrate the following features: (i) new motifs for alkali metal ion complexation (i.e., cationic receptors for cations), (ii) a new family of triaza-metalloligands, and (iii) a double box-like cage. The cages are synthesized by the condensa...
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.062647799
更新日期:2002-04-16 00:00:00
abstract::Rapamycin is an immunosuppressive immunophilin ligand reported as having neurotrophic activity. We show that modification of rapamycin at the mammalian target of rapamycin (mTOR) binding region yields immunophilin ligands, WYE-592 and ILS-920, with potent neurotrophic activities in cortical neuronal cultures, efficacy...
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.0710424105
更新日期:2008-01-08 00:00:00
abstract::It was reported that the rate of elongation of partially reconstituted RNA, if prepared without centrifugation, showed dependency upon the state of protein aggregation like that found when free RNA was used as the nucleic acid source [Butler, P. J. G. (1974) J. Mol. Biol. 82, 333-341]. Butler concluded from this resul...
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.74.2.552
更新日期:1977-02-01 00:00:00
abstract::The synthesis of the proteins laminin and collagen IV is stimulated approximately equal to 20-fold in F9 mouse teratocarcinoma stem cells after treatment of the cells with retinoic acid and N6, O2'-dibutyryl-cAMP (Bt2cAMP). A cDNA library from F9 cells treated with retinoic acid, Bt2cAMP, and theophylline (F9-R + DBC ...
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.80.19.5880
更新日期:1983-10-01 00:00:00
abstract::Vibrational modes in mechanical resonators provide a promising candidate to interface and manipulate classical and quantum information. The observation of coherent dynamics between distant mechanical resonators can be a key step toward scalable phonon-based applications. Here we report tunable coherent phonon dynamics...
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.1916978117
更新日期:2020-03-17 00:00:00
abstract::Colonization of land by plants was a major transition on Earth, but the developmental and genetic innovations required for this transition remain unknown. Physiological studies and the fossil record strongly suggest that the ability of the first land plants to form symbiotic associations with beneficial fungi was one ...
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.1515426112
更新日期:2015-10-27 00:00:00
abstract::The phosphorylation and dephosphorylation of the dihydropyridine-sensitive Ca2+ channel was studied in transverse-tubule membranes isolated from rabbit skeletal muscle. Exposure of these membranes to either the cAMP-dependent protein kinase or a Ca2+/calmodulin-dependent protein kinase resulted in a rapid phosphorylat...
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.83.11.3733
更新日期:1986-06-01 00:00:00
abstract::This paper describes a variety of statistical methods for obtaining precise quantitative estimates of the similarities and differences in the structures of semantic domains in different languages. The methods include comparing mean correlations within and between groups, principal components analysis of interspeaker c...
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.97.1.518
更新日期:2000-01-04 00:00:00
abstract::Since their discovery as key regulators of early animal development, microRNAs now are recognized as widespread regulators of gene expression. Despite their abundance, little is known regarding the regulation of microRNA biogenesis. We show that three highly conserved muscle-specific microRNAs, miR-1, miR-133 and miR-...
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.0602831103
更新日期:2006-06-06 00:00:00
abstract::The mouse skeletal muscle acetylcholine receptor is regulated, at least in part, by transcriptional mechanisms. As a first step toward defining the cis- and trans-acting factors involved in acetylcholine receptor transcriptional regulation, we examined mouse muscle and fibroblast cells for the presence of DNase I-hype...
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.83.21.8405
更新日期:1986-11-01 00:00:00
abstract::Bacteriorhodopsin from Halobacterium halobium has been solubilized in the nonionic detergent Triton X-100. The circular dichroic spectrum and hydrodynamic properties indicate that the structure of this protein in the detergent is not significantly altered from that of the native membrane-bound form. Bacteriorhodopsin ...
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.74.7.2803
更新日期:1977-07-01 00:00:00
abstract::Global increases in population, consumption, and gross domestic product raise concerns about the sustainability of the current and future use of natural resources. The human appropriation of net primary production (HANPP) provides a useful measure of human intervention into the biosphere. The productive capacity of la...
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.1211349110
更新日期:2013-06-18 00:00:00
abstract::The O(2) reduction site of cytochrome c oxidase (CcO), comprising iron (Fe(a3)) and copper (Cu(B)) ions, is probed by x-ray structural analyses of CO, NO, and CN(-) derivatives to investigate the mechanism of the complete reduction of O(2). Formation of the derivative contributes to the trigonal planar coordination of...
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.0910410107
更新日期:2010-04-27 00:00:00
abstract::R. A. Fisher's 1930 "reproductive value" is defined as the contribution made by a population's initial age elements to its asymptotically dominating exponential growth mode. For the Leslie discrete-time model, it is the characteristic row vector of the Leslie matrix, and for the integral-equation model of Lotka the si...
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.74.11.5189
更新日期:1977-11-01 00:00:00
abstract::Protein tyrosine phosphorylation and dephosphorylation are key regulatory events in T-cell receptor (TCR) signaling. We investigated the role of the tyrosine phosphatase SHPTP1 in TCR signaling by analysis of TCR signal transduction in motheaten (me/me) mice, which lack SHPTP1 expression. As revealed by flow cytometri...
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.93.18.9624
更新日期:1996-09-03 00:00:00
abstract::Lymphocyte homeostasis is the result of a critical balance between cell proliferation and death. Disruption of this subtle equilibrium can lead to the onset of leukemia, an increase in the number of lymphocytes being potentially due to both of these parameters. The relative importance of cell proliferation vs. apoptos...
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.142100999
更新日期:2002-07-23 00:00:00
abstract::The cingulate gyri in 37 subjects with and without early dementia of the Alzheimer type (DAT) were studied by using MRI at 1.0 mm3 isotropic resolution. Groups were segregated into young controls (n = 10), age-matched normal controls (n = 10), very mild DAT (n = 8), and mild DAT (n = 9). By using automated Bayesian se...
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.2136624100
更新日期:2003-12-09 00:00:00
abstract::The inositol 1,4,5-trisphosphate receptor (IP3R) associated with plasma membranes of lymphocytes differs in terminal sugar content and binding specificity from the cerebellar receptor, which is localized to endoplasmic reticulum. Lectin column chromatography reveals that 30% of IP3R in the thymus contains sialic acid,...
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.89.7.2849
更新日期:1992-04-01 00:00:00
abstract::Loss of heterozygosity on chromosome 16 is a common genetic alteration in human hepatocellular carcinoma (HCC). To clarify the pathogenetic significance of allele loss on chromosome 16, we performed restriction fragment length polymorphism analysis of 70 surgically resected tumors by using 15 polymorphic DNA markers 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.87.17.6791
更新日期:1990-09-01 00:00:00
abstract::It is shown that initiation of translation involves several steps. (i) Binding of fMet-tRNA(fMet) to the bacterial 30S ribosomal subunit in the absence of messenger RNA, yielding a 34S complex. This binding is rapid and dependent on initiation factor 2 but not on initiation factor 3. (ii) Binding of messenger RNA to t...
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.71.8.3199
更新日期:1974-08-01 00:00:00
abstract::The medial preoptic area has been shown to be intricately involved in many behaviors, including locomotion, sexual behavior, maternal care, and aggression. The gene encoding estrogen receptor-α (ERα) protein is expressed in preoptic area neurons, and a very dense immunoreactive field of ERα is found in the preoptic re...
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.1214094109
更新日期:2012-10-02 00:00:00