全文获取类型
收费全文 | 1213篇 |
免费 | 111篇 |
专业分类
1324篇 |
出版年
2023年 | 10篇 |
2022年 | 16篇 |
2021年 | 30篇 |
2020年 | 24篇 |
2019年 | 15篇 |
2018年 | 28篇 |
2017年 | 24篇 |
2016年 | 34篇 |
2015年 | 59篇 |
2014年 | 58篇 |
2013年 | 72篇 |
2012年 | 79篇 |
2011年 | 64篇 |
2010年 | 55篇 |
2009年 | 53篇 |
2008年 | 64篇 |
2007年 | 50篇 |
2006年 | 59篇 |
2005年 | 50篇 |
2004年 | 53篇 |
2003年 | 49篇 |
2002年 | 36篇 |
2001年 | 19篇 |
2000年 | 33篇 |
1999年 | 27篇 |
1998年 | 20篇 |
1997年 | 19篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 14篇 |
1991年 | 17篇 |
1990年 | 18篇 |
1989年 | 20篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1977年 | 4篇 |
1975年 | 7篇 |
1973年 | 4篇 |
1971年 | 4篇 |
1969年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有1324条查询结果,搜索用时 0 毫秒
111.
de la Vega E Degnan BM Hall MR Cowley JA Wilson KJ 《Diseases of aquatic organisms》2004,59(3):195-203
Gill-associated virus (GAV) of the black tiger prawn Penaeus monodon has been implicated as a cause of periodic production losses in Australia since 1996. We report here the development of a real-time quantitative RT-PCR (qRT-PCR) for GAV. A dilution series of in vitro transcribed RNA was used to determine the sensitivity limit of the qRT-PCR and as a standard for GAV quantification. A linear relationship between cycle threshold (Ct) values and input RNA was obtained over a wide concentration range between 4.86 x 10(9) and 0.5 template copies per reaction, the latter being the test detection limit. The qRT-PCR was used to follow the progression of GAV levels in a group of 15 adult male P. monodon with chronic GAV infections that were super-infected by intramuscular injection of an inoculum containing high levels of GAV. By Day 9 post-injection, cumulative mortalities reached 100% (15/15) in the GAV-injected prawns and 40% (2/5) in placebo-injected prawns. Spermatophores were collected at the beginning, and together with other tissues, at the end of the trial. Prawns were also bled at regular intervals to collect circulating haemocytes. The qRT-PCR revealed that GAV loads increased significantly in haemocytes collected from both the control and super-infected prawns (p = 0.010). This increase was significantly higher in the super-infected prawns (p = 0.047). The rapid increase in GAV levels in super-infected P. monodon was expected. However, the increase in the control prawns was not, and indicates that repetitive bleeding and handling stress can stimulate GAV proliferation in chronically infected P. monodon. 相似文献
112.
Germanà A Levanti MB Monjil DF Ciriaco E Del Valle M Vega JA Germanà G 《European journal of histochemistry : EJH》2004,48(4):373-376
The presence and cell localization of TrkB, the main receptor for the neurotrophins (NTs), was investigated immunohistochemically in the small intestine of adult pigeons, with special reference to the enteric nervous system (ENS). Several neuronal (neurofilament proteins and PGP 9.5) and glial cell (S100 protein) markers were studied in parallel. TrkB immunoreactivity (TrkB-IR) was found to be restricted to immunohistochemically-identified glial cells present in the enteric plexuses, and to Schwann cells forming the perivascular plexus. Also, TrkB-IR was detected in enterochromaffin cells and in unidentified dendritic cells within the gut-associated lymphoid tissue. The present results demonstrate that as for mammals, TrkB in the ENS is restricted to the glial cells. The possible function of the TrkB ligands, however, remains to be established. 相似文献
113.
Prognostic value of cytokines in SIRS general medical patients 总被引:12,自引:0,他引:12
Rodríguez-Gaspar M Santolaria F Jarque-López A González-Reimers E Milena A de la Vega MJ Rodríguez-Rodríguez E Gómez-Sirvent JL 《Cytokine》2001,15(4):232-236
We studied 174 patients with SIRS criteria, 45 with sepsis, eight with severe sepsis and 13 with septic shock. Serum TNF-alpha, IL-6, IL-8 and IL-10 levels were raised in SIRS patients, even in those cases in which an infection could not be documented, and more intensely in severe sepsis and in patients who died (11%). The slope of the regression line between IL-10 and TNF-alpha was sharper in patients with severe sepsis and in those who died; an imbalance between pro- and anti-inflammatory cytokines may be related to poor prognosis. Increased IL-6 and IL-10, decreased muscle mass, raised BUN and low body temperature were all independently related to prognosis. 相似文献
114.
115.
116.
Biological potential of a functional human SNAIL retrogene 总被引:6,自引:0,他引:6
Locascio A Vega S de Frutos CA Manzanares M Nieto MA 《The Journal of biological chemistry》2002,277(41):38803-38809
117.
Stadler K Masignani V Eickmann M Becker S Abrignani S Klenk HD Rappuoli R 《Nature reviews. Microbiology》2003,1(3):209-218
The 114-day epidemic of the severe acute respiratory syndrome (SARS) swept 29 countries, affected a reported 8,098 people, left 774 patients dead and almost paralyzed the Asian economy. Aggressive quarantine measures, possibly aided by rising summer temperatures, successfully terminated the first eruption of SARS and provided at least a temporal break, which allows us to consolidate what we have learned so far and plan for the future. Here, we review the genomics of the SARS coronavirus (SARS-CoV), its phylogeny, antigenic structure, immune response and potential therapeutic interventions should the SARS epidemic flare up again. 相似文献
118.
119.
Oliva A Borriello A Zeppetelli S Di Feo A Cortellazzi P Ventriglia V Criscuolo M Zappia V Della Ragione F 《Molecular and cellular biochemistry》2003,247(1-2):55-60
The importance of bone marrow mesenchymal stem cells in hemopoiesis has been definitely demonstrated. Thus, their impairment might cause profound alteration on production and maturation of blood cells. In the present paper, we investigated, for the first time, the effect of retinoic acid, an important antileukemic molecule, on the proliferation of primary cultures of human bone marrow mesenchymal stem cells. We demonstrated that retinoic acid, at a pharmacological concentration, hampers strongly the growth of the cells, without inducing osteoblastic differentiation. The analysis of cell division cycle machinery showed that the antiproliferative effect is associated with (i) the up-regulation of two cyclin-dependent kinase inhibitors, namely p27Kip1 and p16INK4A, and (ii) the down-regulation of cyclin-dependent kinase 2 activity and pRB phosphorylation. The reported findings represent novel insights into the antileukemic effects of the drug and contribute in clarifying the molecular mechanism of its pharmacological activity. 相似文献
120.
Crespo MI Gràcia J Puig C Vega A Bou J Beleta J Doménech T Ryder H Segarra V Palacios JM 《Bioorganic & medicinal chemistry letters》2000,10(23):2661-2664
A novel series of 2,5-dihydropyrazolo[4,3-c]quinolin-3-ones has been prepared. These compounds showed good PDE 4 inhibitory activity and weak affinity for rolipram's binding site. They also exhibited a good anti-inflammatory profile without emetic side effects. 相似文献