全文获取类型
收费全文 | 93篇 |
免费 | 7篇 |
出版年
2021年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1965年 | 2篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有100条查询结果,搜索用时 377 毫秒
71.
72.
Feraud M Masclaux-Daubresse C Ferrario-Méry S Pageau K Lelandais M Ziegler C Leboeuf E Jouglet T Viret L Spampinato A Paganelli V Hammouda MB Suzuki A 《Planta》2005,222(4):667-677
GLU1 encodes the major ferredoxin-dependent glutamate synthase (Fd-GOGAT, EC 1.4.7.1) in Arabidopsis thaliana (ecotype Columbia). With the aim of providing clues on the role of Fd-GOGAT, we analyzed the expression of Fd-GOGAT in tobacco
(Nicotiana tabacum L. cv. Xanthi). The 5′ flanking element of GLU1 directed the expression of the uidA reporter gene in the palisade and spongy parenchyma of mesophyll, in the phloem cells of vascular tissue and in the roots
of tobacco. White light, red light or sucrose induced GUS expression in the dark-grown seedlings in a pattern similar to the GLU1 mRNA accumulation in Arabidopsis. The levels of GLU2 mRNA encoding the second Fd-GOGAT and NADH-glutamate synthase (NADH-GOGAT, EC 1.4.1.14) were not affected by light. Both
in the light and in darkness, 15NH4+ was incorporated into [5−15N]glutamine and [2−15N]glutamate by glutamine synthetase (GS, EC 6.3.1.2) and Fd-GOGAT in leaf disks of transgenic tobacco expressing antisense
Fd-GOGAT mRNA and in wild-type tobacco. In the light, low level of Fd-glutamate synthase limited the [2−15N]glutamate synthesis in transgenic leaf disks. The efficient dark labeling of [2−15N]glutamate in the antisense transgenic tobacco leaves indicates that the remaining Fd-GOGAT (15–20% of the wild-type activity)
was not the main limiting factor in the dark ammonium assimilation. The antisense tobacco under high CO2 contained glutamine, glutamate, asparagine and aspartate as the bulk of the nitrogen carriers in leaves (62.5%), roots (69.9%)
and phloem exudates (53.2%). The levels of glutamate, asparagine and aspartate in the transgenic phloem exudates were similar
to the wild-type levels while the glutamine level increased. The proportion of these amino acids remained unchanged in the
roots of the transgenic plants. Expression of GLU1 in mesophyll cells implies that Fd-GOGAT assimilates photorespiratory and primary ammonium. GLU1 expression in vascular cells indicates that Fd-GOGAT provides amino acids for nitrogen translocation.
The nucleotide sequence data of the GLU1 gene reported in the present study is available from GenBank with the following accession number: AY189525 相似文献
73.
By means of partition and preparative TLC, two pro-inflammatory diterpene esters were isolated from Euphorbia peplus. These compounds were identified as 20-deoxyingenol 3-O-angelate which exhibited an ID50 of O.18 μg on mice and the new ester ingenol 20-O-octanoate which exhibited an ID50 of 1.0 μg also on mice skin. 相似文献
74.
Summary The effect of pre-sowing -irradiation of cotton seeds from a point source of Cs137 on emergence, growth, flowering, and yield was studied. High radiation doses caused reduction of emergence, inhibition of growth retardation of flowering, and reduction in number of flowers and bolls produced by the plant. The yield was greatly reduced under high dosages and approached that of the control plants under low dosages. -rays caused a marked degree of sterility.No significant stimulating effect on growth and development was detected when the dry cotton seeds were subjected to -irradiation doses of 1.17 to 26.92 kr. 相似文献
75.
Capparis ovata var. palaestina Zoh., C. spinosa var. aegyptia Boiss. and C. spinosa var. deserti Zoh., were investigated for glucosinolates. Glucoiberin, glucocapparin, sinigrin, glucocleomin, glucocapangulin, glucobrassicin and neoglucobrassicin, in addition to two others, were isolated. Four of these viz. glucoiberin, sinigrin, glucobrassicin and neoglucobrassicin were detected for the first time in Capparis species. Comparative chromatographic analyses of the glucosinolates of the plants examined revealed qualitative differences. 相似文献
76.
77.
78.
MB Lazarova-Bakarova S Stancheva B Petkova M Genkova-Papasova L Alova E Boyanova D Staneva-Stoytcheva 《Journal of Physiology》1997,91(6):301-305
The effects of the β-adrenoceptor blocker pindolol and the calcium antagonist verapamil administered alone or in combination on retention in step-down- and shuttle-box-trained rats and on the biogenic monoamine levels in the frontal cortex and hippocampus were examined. The chronic oral treatment with pindolol impaired retention in step-down- and shuttle-box-trained rats, decreasing the dopamine (DA) and noradrenaline (NA) levels and increasing the serotonin (5-HT) levels in the cortex and hippocampus. Verapamil did not influence retention in step-down- and shuttle-box avoidance situation and the biogenic monoamine levels in the frontal cortex and hippocampus. It should, however, be noted that the chronic oral treatment with verapamil completely abolished the retention-impairing effect of pindolol, restoring to normal DA, NA and 5-HT levels. These findings might be of interest to clinical practice and suggest the necessity for using a combination of β-blockers with Ca2+ antagonists in case of prolonged treatment of cardiovascular diseases. 相似文献
79.
Solvent-induced free energy landscape and solute-solvent dynamic coupling in a multielement solute 下载免费PDF全文
San Biagio PL V Martorana V D Bulone MB Palma-Vittorelli MU Palma 《Biophysical journal》1999,77(5):2470-2478
Molecular dynamics simulations using a simple multielement model solute with internal degrees of freedom and accounting for solvent-induced interactions to all orders in explicit water are reported. The potential energy landscape of the solute is flat in vacuo. However, the sole untruncated solvent-induced interactions between apolar (hydrophobic) and charged elements generate a rich landscape of potential of mean force exhibiting typical features of protein landscapes. Despite the simplicity of our solute, the depth of minima in this landscape is not far in size from free energies that stabilize protein conformations. Dynamical coupling between configurational switching of the system and hydration reconfiguration is also elicited. Switching is seen to occur on a time scale two orders of magnitude longer than that of the reconfiguration time of the solute taken alone, or that of the unperturbed solvent. Qualitatively, these results are unaffected by a different choice of the water-water interaction potential. They show that already at an elementary level, solvent-induced interactions alone, when fully accounted for, can be responsible for configurational and dynamical features essential to protein folding and function. 相似文献
80.
M Kale R Ramsey-Goldman S Bernatsky MB Urowitz D Gladman PR Fortin M Petri E Yelin S Manzi S Edworthy O Nived S-C Bae D Isenberg A Rahman JG Hanly C Gordon S Jacobsen E Ginzler DJ Wallace GS Alarcón MA Dooley L Gottesman K Steinsson A Zoma J-L Senécal S Barr G Sturfelt L Dreyer L Criswell J Sibley JL Lee AE Clarke 《Arthritis research & therapy》2012,14(Z3):A15