全文获取类型
收费全文 | 110篇 |
免费 | 16篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2015年 | 2篇 |
2014年 | 9篇 |
2013年 | 3篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 11篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有126条查询结果,搜索用时 15 毫秒
51.
Background
Despite recent achievements to reduce child mortality, neonatal deaths continue to remain high, accounting for 41% of all deaths in children under five years of age worldwide, of which over 90% occur in low- and middle-income countries (LMICs). Infections are a leading cause of death and limitations in care seeking for ill neonates contribute to high mortality rates. As estimates for care-seeking behaviors in LMICs have not been studied, this review describes care seeking for neonatal illnesses in LMICs, with particular attention to type of care sought.Methods and Findings
We conducted a systematic literature review of studies that reported the proportion of caregivers that sought care for ill or suspected ill neonates in LMICs. The initial search yielded 784 studies, of which 22 studies described relevant data from community household surveys, facility-based surveys, and intervention trials. The majority of studies were from South Asia (n = 17/22), set in rural areas (n = 17/22), and published within the last 4 years (n = 18/22). Of the 9,098 neonates who were ill or suspected to be ill, 4,320 caregivers sought some type of care, including care from a health facility (n = 370) or provider (n = 1,813). Care seeking ranged between 10% and 100% among caregivers with a median of 59%. Care seeking from a health care provider yielded a similar range and median, while care seeking at a health care facility ranged between 1% and 100%, with a median of 20%. Care-seeking estimates were limited by the few studies conducted in urban settings and regions other than South Asia. There was a lack of consistency regarding illness, care-seeking, and care provider definitions.Conclusions
There is a paucity of data regarding newborn care-seeking behaviors; in South Asia, care seeking is low for newborn illness, especially in terms of care sought from health care facilities and medically trained providers. There is a need for representative data to describe care-seeking patterns in different geographic regions and better understand mechanisms to enhance care seeking during this vulnerable time period. Please see later in the article for the Editors'' Summary 相似文献52.
Heparin and its derivatives bind to HIV-1 recombinant envelope glycoproteins, rather than to recombinant HIV-1 receptor, CD4 总被引:1,自引:0,他引:1
We have employed a direct radiolabel binding assay to investigate the
interaction between3H-heparin and recombinant envelope glycoproteins,
rgp120s, derived from several different isolates of HIV-1. Comparable
dose-dependent binding is exhibited by rgp120s from isolates IIIB, GB8, MN
and SF-2. Under identical experimental conditions the binding of3H- heparin
to a recombinant soluble form of the cellular receptor for gp120, CD4, is
negligible. The binding of3H-heparin to rgp120 is competed for by excess
unlabeled heparin and certain other, but not all, glycosaminoglycan and
chemically modified heparins. Of a range of such polysaccharides tested,
ability to compete with3H-heparin for binding was strictly correlated with
inhibition of HIV-1 replication in vitro. Those possessing potent
anti-HIV-1 activity were effective competitors, whereas those having no or
little anti-HIV-1 activity were poor competitors. Scatchard analysis
indicates that the K d of the interaction between heparin and rgp120 is 10
nM. Binding studies conducted in increasing salt concentrations confirm
that the interaction is ionic in nature. Synthetic 33-35 amino acid
peptides based on the sequence of the V3 loop of gp120 also bind to heparin
with high affinity. V3 loop peptides that are cyclized due to terminal
cysteine residues show more selective binding than their uncyclized
counterparts. Overall, these data demonstrate further that heparin exerts
its anti-HIV-1 activity by binding to the envelope glycoprotein of HIV-1,
rather than its cellular receptor, CD4. This study confirms that the V3
loop of gp120 is the site at which heparin exerts its anti- HIV-1 activity.
Moreover, it reveals that high affinity binding to heparin is shared by all
four rgp120s examined, despite amino acid substitutions within the V3 loop.
相似文献
53.
A mouse genomic clone containing a lactate dehydrogenase-A (LDH-A)
processed pseudogene and a B1 repetitive element was isolated, and a
nucleotide sequence of approximately 3 kb was determined. The pseudogene
and B1 element are flanked by perfect 13-bp repeats, and the B1 sequence
starts at 14 nucleotides 3' to the presumptive polyadenylation signal of
the pseudogene. The nucleotide sequences of the LDH-A genes and processed
pseudogenes from mouse, rat, and human were compared, and a phylogenetic
tree was constructed. The rate and pattern of nucleotide substitutions in
the LDH-A pseudogenes are similar to previously reported results (Li et al.
1984). The average rate of nucleotide substitutions in the LDH-A
pseudogenes is 4.3 X 10(- 9)/site/year. The substitutions of C----T and
G----A are most frequent, and A----G substitutions are relatively high. The
rate of synonymous substitutions in the LDH-A genes is 5.3 X 10(-9), which
is not significantly higher than the average rate of 4.7 X 10(-9) for 35
mammalian genes. The rate of nonsynonymous substitutions in the LDH-A genes
is 0.20 X 10(-9), which is considerably lower than the average rate of 0.88
X 10(-9) for 35 mammalian genes. Thus, the mammalian LDH-A gene appears to
be highly conserved in evolution.
相似文献
54.
Marie-Louise Bouillant Jean-Louis Pittet Jacques Bernillon Jean Favre-Bonvin Noël Arpin 《Phytochemistry》1981,20(12):2705-2707
The chemical structure of the mycosporin isolated from Ascochyta pisi, Cladosporium herbarum and Septoria nodorum was established as mycosporin-2 glucoside. 相似文献
55.
Jacques Fayret Jacques Bernillon Marie-Louise Bouillant Jean Favre-Bonvin Noël Arpin 《Phytochemistry》1981,20(12):2709-2710
The three reproductive forms of Gnomonia leptostyla synthesize mycosporin-2 ring and open forms. The chemical structures were determined from NMR and MS data. 相似文献
56.
Ribosomal proteins from pure free and membrane-bound rat liver polysomes were analyzed with a highly resolutive two-dimensional gel electrophoresis technique, using sodium dodecyl sulfate in the second dimension. Three acidic proteins found in free polysomes were always absent from the membrane-bound polysomes. Their molecular weights were estimated to be 20 000, 19 500 and 18 500. When free ribosomes were dissociated into subunits, the three protein spots were still found in the 60S subunit pattern, but they were weaker than in polysomes. A possible involvement of these three proteins in the attachment of ribosomal structures to the membranes is proposed. 相似文献
57.
58.
59.
Co-operative effect of c-Src and ezrin in deregulation of cell-cell contacts and scattering of mammary carcinoma cells 总被引:3,自引:0,他引:3
The non-receptor tyrosine kinase c-Src is activated in many human cancer types, and induces deregulation of cadherin-based cell-cell contacts and actin cytoskeleton. Because ezrin, a protein which cross-links the plasma membrane with the actin cytoskeleton, is often over-expressed in human cancers, and participates in cell adhesion, motility, and cell scattering, we therefore investigated whether c-Src co-operates with ezrin in regulating cell-cell contacts in a murine mammary carcinoma cell line, SP1. SP1 cells over-expressing wild type ezrin, or an activated c-Src mutant, formed loose aggregates which scattered spontaneously when plated on plastic. When wild type ezrin and activated c-Src were co-expressed, scattering was increased, cell-cell contacts disrupted, and cell aggregation prevented. Pre-treatment with the c-Src family kinase inhibitor PP2 partially restored aggregation of cells expressing activated c-Src and wild type ezrin, indicating that c-Src family kinases act co-operatively with ezrin in regulating cell-cell contacts. Furthermore, expression of a truncated NH2-terminal domain of ezrin, which has dominant negative function, blocked the cell scattering effect of activated c-Src and promoted formation of cohesive cell-cell contacts. Together, these results suggest co-operativity between c-Src and ezrin in deregulation of cell-cell contacts and enhancing scattering of mammary carcinoma cells. 相似文献
60.
Jacques Bernillon Marie-Louise Bouillant Jean-Louis Pittet Jean Favre-Bonvin Noël Arpin 《Phytochemistry》1984,23(5):1083-1087
The structure of mycosporine glutamine, a new compound, has been established and its presence demonstrated in two fungi Pyronema omphalodes and Glomerella cingulata. Mycosporine glutamic acid has been isolated from Helvella leucomelaneae. Co-occurrence of normycosporine glutamine, mycosporine glutamine and glucosylmycosporine glutaminol has been demonstrated in the fungus P. omphalodes. A biosynthetic pathway is proposed. Mycosporines have been compared by HPLC. 相似文献