全文获取类型
收费全文 | 563篇 |
免费 | 32篇 |
出版年
2019年 | 3篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 18篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 28篇 |
2011年 | 41篇 |
2010年 | 20篇 |
2009年 | 18篇 |
2008年 | 39篇 |
2007年 | 32篇 |
2006年 | 18篇 |
2005年 | 17篇 |
2004年 | 21篇 |
2003年 | 15篇 |
2002年 | 22篇 |
2001年 | 21篇 |
2000年 | 10篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 17篇 |
1988年 | 12篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1984年 | 5篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1979年 | 12篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 8篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1966年 | 5篇 |
1965年 | 3篇 |
1957年 | 5篇 |
排序方式: 共有595条查询结果,搜索用时 15 毫秒
551.
Summary The surface of the egg of the two sea urchin species,Strongylocentrotus droebachiensis andS. pallidus, was studied with SEM. Clear differences were observed between the two species, in both the number and form of the microvilli. The changes in the egg surface which follow insemination are described. 相似文献
552.
Characteristics of many tumor types are the reprogramming of metabolism and the occurrence of regional hypoxia. In this work, we investigated the hypothesis that metabolic reprogramming in combination with metabolic zonation of cellular energy metabolism are important factors in promotion of the growth capacity of solid tumors. A tissue-scale model of the two main ATP delivering pathways, glycolysis (GLY) and oxidative phosphorylation (OXP), was used to simulate the energy metabolism within solid tumors under various metabolic strategies. Remarkably, despite the high diversity in the usage of glucose, lactate and oxygen in various spatial regions, the tumor as a whole clearly displays the hallmark of the so-called Warburg effect, i.e. a high rate of glucose consumption and lactate production in the presence of sufficiently high levels of oxygen. Our simulations suggest that an increase in GLY capacity and concomitant decrease in OXP capacity from the periphery towards the center of the tumor improves the availability of oxygen to pericentral tumor cells. The found relationship between the regional oxygen level and the relative share of GLY and OXP capacities supports the view that metabolite availability functions as key regulator of tumor energy metabolism. 相似文献
553.
554.
Reinhard Berndt 《Mycological Progress》2002,1(2):179-186
Uromyces vankyorum (Basidiomycota, Uredinales) growing on Atriplex lampa in the cool Patagonian dwarf shrub semi-desert is described as a new species and a new member of the Argentinean rust mycota.
The fungus is morphologically similar to Uromyces atriplicis on Atriplex vesicaria from halophytic shrublands of South Australia. U. atriplicis seems to be derived from U. vankyorum as indicated by its shortened life cycle lacking the urediniospore stage.
The species are interpreted as trans-pacific vicariants and represent one of the rare examples for the austral South American-Australasian
element among rust fungi. The disjunct distribution of rust fungi between austral South America, Australia and New Zealand
is reviewed and discussed. Available data suggest migration of rust fungi along Gondwanan land bridges rather than long-distance
dispersal of spores by air currents.
Part 198 of the series “Studies in Heterobasidiomycetous Fungi” of the Botanical Institute, University of Tübingen 相似文献
555.
H Berndt 《Hoppe-Seyler's Zeitschrift für physiologische Chemie》1979,360(6):747-760
The synthesis of sequence 71-86 of human proinsulin (sequence 6-21 of human insulin A-chain) via its monomeric cyclic dicystine peptide derivative (XXII) and the corresponding tetra-S-trityl-peptide derivative (XVIII) is described. The good solubility of the derivatives (XXII, XVIII) in orgranic solvents makes it possible to purify both the derivatives in their protected form. The S-trityl derivative (XVIII) enables the synthesis of the fragment 71-86 in a scale needed for the planned synthesis of human proinsulin. 相似文献
556.
Gert Lange J. O. Hüsing Kurt Bauer Kurt Kräuter Rudolf Berndt Helmut Albrecht Dietland Müller Diether Eberhardt J. Peitzmeier und P. Westerfrölke 《Journal of Ornithology》1960,101(3):360-365
Ohne Zusammenfassung 相似文献
557.
558.
559.
R. Oertel K. Richter B. Trausch A. Berndt T. Gramatt W. Kirch 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1994,660(2):353-363
The objective of this study was to determine the structure of talinolol metabolites formed and the amounts excreted in urine. Talinolol metabolites in urine were identified by comparing their HPLC retention times and their GC—MS profile with those of previously characterized reference compounds. The metabolites were quantified by HPLC with a normal-phase silica column, a single chloroform extraction and UV detection. Less than 1% of an administered dose was found in urine as hydroxylated talinolol. Other metabolites could be excluded. A sensitive method to determine talinolol in serum and a simple method for analysis of talinolol in urine are described. These methods were found to be precise and accurate for the measurement of talinolol in samples obtained from patients during chronic talinolol treatment as well as from healthy volunteers after a single dose of talinolol. 相似文献
560.