全文获取类型
收费全文 | 354篇 |
免费 | 25篇 |
专业分类
379篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 13篇 |
2015年 | 22篇 |
2014年 | 19篇 |
2013年 | 42篇 |
2012年 | 25篇 |
2011年 | 23篇 |
2010年 | 17篇 |
2009年 | 11篇 |
2008年 | 22篇 |
2007年 | 23篇 |
2006年 | 21篇 |
2005年 | 26篇 |
2004年 | 15篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1975年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有379条查询结果,搜索用时 0 毫秒
371.
GLYCOPROTEIN CHANGES DURING THE DEVELOPMENT OF HUMAN BRAIN 总被引:4,自引:4,他引:0
Brain glycoprotein sugars were studied during human brain development. Marked changes were found in the sugar content of glycopeptides derived from soluble and insoluble glycoproteins, showing a general decrease in the soluble and an increase in the insoluble fraction. The data indicate that changes in glycan moiety and/or in glycoprotein population occur during development. The existence of a‘critical period’in glycoprotein development which coincides with the formation of axonal and synaptic membranes sprouting has been established (Dobbing , 1971). 相似文献
372.
Maria Benedetta Fadda Maria Rita Dessì Raffaele Maurici Augusto Rinaldi Giuseppe Satta 《Applied microbiology and biotechnology》1984,19(5):306-311
Summary A commercial preparation of cellulase was immobilized on CNBr-sepharose, ConA-sepharose, and CNBr-glass beads. When filter paper was used as the substrate, the specific activity of the enzyme immobilized on ConA-sepharose was more than twice that of the soluble enzyme, while the activity of the enzymes immobilized on the other two substrates was either very slightly (CNBr-sepharose) or slightly (CNBr-glass beads) reduced. The immobilized enzymes showed alterations both in the Km and V max values: these were generally either slightly increased (Km) or reduced (V max). In addition, the immobilized enzymes were more resistant to inhibition both by glucose and cellobiose, they were all more stable than the soluble enzyme and solubilized three different natural lignocellulosic materials (alfa-alfa, wheat straw, and pine needles) to a much greater or significantly greater extext than the soluble enzyme: the ConA-sepharose cellulase was the most efficient. The possibility of reusing the immobilized enzyme was also tested. It was found that the ConA-sepharose cellulase could be reused five times with a final loss of activity that ranged between 30% and 50%. 相似文献
373.
374.
Manuela Cabiati Benedetta Svezia Marco Matteucci Luca Panchetti Silvia Burchielli Maria-Aurora Morales 《Journal of receptor and signal transduction research》2017,37(4):379-385
Purpose: Eight A2AR variants are reported in humans while no A2AR isoforms in pigs. The aim of this study was to evaluate potential isoforms presence in cardiac pig tissue to better define possible involvement of A2AR in the cardiovascular pathophysiology.Materials and methods: In adult male minipigs (n?=?4) left ventricular dysfunction (LVD) was induced by pacing at 200 bpm in the right ventricular (RV) apex. In these animals and in sham operated pigs (C-SHAM, n?=?4) cardiac tissue was collected from LV-septal wall (LV-SW)-close to pacing site-and from lateral (opposite) site (LV-OSW). A2AR specific primers, derived from Sus scrofa AY772412 sequence, were used for Real-Time PCR. The DNA was sequenced using the Sanger method. Histological analysis was also performed.Results: In LV-SW of LVD minipigs the A2AR melting curves were characterized by a sharp peak between 87 and 91?°C (short isoform, 1–94?bp) on the right of the principal peak corresponding to a long A2AR isoform (GenBank: JQ229674.1) 1–213?bp. As for C-SHAM only one peak was observed in LV-OSW region of LVD animals. The short isoform had an alternative promoter region and a specific translated protein. Histology showed in LVD-LV-SW prominent Purkinje cells compared to LV-OSW and C-SHAM. No difference in A2AR expression was observed between LVD animals and C-SHAM although a slight decrease was observed in LVD-LV-OSW.Conclusions: The presence of two different isoforms in the myocardium close to the insertion of pacing is suggestive of a differential state-specific expression of A2AR in cardiac tissue. 相似文献
375.
Different approaches for the isolation of stem/progenitor cells have been reported, including stem cell selection in stringent culture conditions. We evaluated the possibility of isolating human progenitor cells from surgical specimens preserved by under vacuum sealing and cooling, a clinical practice approached by several hospitals as alternative to formalin. Renal tissue samples (n = 20) maintained under vacuum from 6 to 48 h at 4°C were used to isolate human renal CD133+ progenitor cells. We obtained CD133+ progenitors from unsorted cells derived from disaggregated tissues from each sample. Phenotypic characterization as well as in vitro and in vivo differentiation of the obtained CD133+ lines showed results comparable with sorted CD133+ cells obtained from fresh tissue. These results indicate that the process of sealing under vacuum and cooling appears as a suitable tissue treatment to isolate hypoxia resistant cells, such as human stem/progenitor cells, and that this procedure can be exploited to render the extraction of stem cells from human samples more practical and feasible. 相似文献
376.
377.
378.
379.
Laura Curatolo Maria Grazia Alessio Bruno Casali Anna Falanga Maria Benedetta Donati Nicola Semeraro 《In vitro cellular & developmental biology. Plant》1989,25(4):388-388
The online version of the original article can be found at 相似文献