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1.
H. Takeuchi T. Morimasa M. Matsumoto 《Cellular and molecular life sciences : CMLS》1977,33(7):938-939
Summary Several peptides were separated from-chymotrypsin-treated physalaemin by high voltage paper electrophoresis, and inhibition of the excitability of a molluscan giant neurone (tonically autoactive neurone) by the tripeptide, Lys-Phe-Tyr, was demonstrated.We thank Dr Sadaaki Iwanaga of Osaka University and Dr Atsuo Inoue of Daiichi Pharmaceutical CO for their helpful advice and the donation of the tripeptide (Lys-Phe-Tyr). 相似文献
2.
We examined effects of several vasoactive peptides (substance P, physalaemin, neurotensin, bradykinin, angiotensin etc.) on the excitability of molluscan giant neurones identified in the subesophageal ganglia of Achatina fulica Férussac. Of these peptides, only physalaemin showed a remarkable excitatory effect on a giant tonically autoactive neurone. 相似文献
3.
Tezuka H Abe Y Iwata M Takeuchi H Ishikawa H Matsushita M Shiohara T Akira S Ohteki T 《Nature》2007,448(7156):929-933
Immunoglobulin-A has an irreplaceable role in the mucosal defence against infectious microbes. In human and mouse, IgA-producing plasma cells comprise approximately 20% of total plasma cells of peripheral lymphoid tissues, whereas more than 80% of plasma cells produce IgA in mucosa-associated lymphoid tissues (MALT). One of the most biologically important and long-standing questions in immunology is why this 'biased' IgA synthesis takes place in the MALT but not other lymphoid organs. Here we show that IgA class-switch recombination (CSR) is impaired in inducible-nitric-oxide-synthase-deficient (iNOS-/-; gene also called Nos2) mice. iNOS regulates the T-cell-dependent IgA CSR through expression of transforming growth factor-beta receptor, and the T-cell-independent IgA CSR through production of a proliferation-inducing ligand (APRIL, also called Tnfsf13) and a B-cell-activating factor of the tumour necrosis factor (TNF) family (BAFF, also called Tnfsf13b). Notably, iNOS is preferentially expressed in MALT dendritic cells in response to the recognition of commensal bacteria by toll-like receptor. Furthermore, adoptive transfer of iNOS+ dendritic cells rescues IgA production in iNOS-/- mice. Further analysis revealed that the MALT dendritic cells are a TNF-alpha/iNOS-producing dendritic-cell subset, originally identified in mice infected with Listeria monocytogenes. The presence of a naturally occurring TNF-alpha/iNOS-producing dendritic-cell subset may explain the predominance of IgA production in the MALT, critical for gut homeostasis. 相似文献
4.
5.
T. Aoyagi T. Wada F. Kojima M. Nagai S. Harada T. Takeuchi K. Isse M. Ogura M. Hamamoto K. Tanaka T. Nagao 《Cellular and molecular life sciences : CMLS》1992,48(7):656-659
Previously we reported that there is a kallikrein deficiency in the cerebral tissue of patients with Alzheimer-type dementia. The present study was performed to investigate protease changes in the serum of these patients. The results showed that the kallikrein activity was normal, but that the activities of plasmin and urokinase were significantly low. The present findings indicate a derangement in the clotting and fibrinolytic systems in Alzheimer patients. 相似文献
6.
Summary L-Phe-L-Tyr and L-Lys-L-Phe-L-Tyr showed a marked inhibitory effect (not chloride-dependent) on the excitability of an identifiable giant neurone (the TAN) of Achatina fulica Férussac, while L-Tyr-L-phe, L-Tyr-L-Tyr, L-Phe-L-Phe, L-Lys-L-Phe and Z-L-Phe-L-Tyr (Z-: carbobenzoxy) had no effect.Authors wish to thank Dr Atsuo Inoue of Daiichi Pharmaceutical Co. for his helpful advice, and Miss Hiroko Tamura for her technical assistance. 相似文献
7.
Free fatty acids regulate insulin secretion from pancreatic beta cells through GPR40 总被引:32,自引:0,他引:32
Itoh Y Kawamata Y Harada M Kobayashi M Fujii R Fukusumi S Ogi K Hosoya M Tanaka Y Uejima H Tanaka H Maruyama M Satoh R Okubo S Kizawa H Komatsu H Matsumura F Noguchi Y Shinohara T Hinuma S Fujisawa Y Fujino M 《Nature》2003,422(6928):173-176
Diabetes, a disease in which carbohydrate and lipid metabolism are regulated improperly by insulin, is a serious worldwide health issue. Insulin is secreted from pancreatic beta cells in response to elevated plasma glucose, with various factors modifying its secretion. Free fatty acids (FFAs) provide an important energy source as nutrients, and they also act as signalling molecules in various cellular processes, including insulin secretion. Although FFAs are thought to promote insulin secretion in an acute phase, this mechanism is not clearly understood. Here we show that a G-protein-coupled receptor, GPR40, which is abundantly expressed in the pancreas, functions as a receptor for long-chain FFAs. Furthermore, we show that long-chain FFAs amplify glucose-stimulated insulin secretion from pancreatic beta cells by activating GPR40. Our results indicate that GPR40 agonists and/or antagonists show potential for the development of new anti-diabetic drugs. 相似文献
8.
Pigment granules in choroidal melanophores of the albino goldfish contained fine particulate materials which were in various degrees aggregated in clumps. Tyrosinase was considered to be present in an inhibited state in these pigment granules. 相似文献
9.
<正> This paper analyzes performance of optimal channel estimation and multiuser detection(MUD) in a block-fading code-division multiple-access (CDMA) channel on the assumptions of randomspreading and large-system limit,by using the replica method developed in statistical mechanics.The authors find that the asymptotic spectral efficiency of the linear minimum mean-squared error(LMMSE) MUD which was proposed and analyzed by Evans and Tse in 2000 is indistinguishable fromthat of the optimal MUD for small system loads.Our results imply that performance of MUD scarcelyimproves even if one spends more computational cost than that of the LMMSE MUD,i.e.,at most thecube of the number of users,on the above-described conditions. 相似文献
10.
A single whole-body X-irradiation of pregnant Wistar rats at a dose of 1.05 Gy at 10.30, 12.30 and 14.30 h respectively, of gestational day 10 resulted in significantly high incidences of hydrocephalic offspring. No hydrocephalic offspring resulted from X-irradiation of pregnant rats with 1.05 Gy at 16.30 h, whereas a dose of 1.22 Gy at 16.30 h resulted in a low but statistically significant incidence of hydrocephalus. Neither 1.05 Gy nor 1.22 Gy X-irradiation of pregnant rats at 18.30 h resulted in any hydrocephalic offspring. Dysplasia of the subcommissural organ was noticed in all the hydrocephalic brains histologically examined. 相似文献