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951.
952.
Central-place foragers organize their feeding trips both to feed themselves and to provide their offspring with food. In seabirds, several long-range foragers have been shown to alternate long and short trips to balance these dual needs. However, the strategies of short-range foragers remain poorly understood. We used a precise, miniaturized motion sensor to examine the time budget of 20 breeding Cape gannets, Morus capensis, foraging off the coast of South Africa. Birds stayed at sea for 5.5-25.3 h, occasionally spending the night at sea. The large number of isolated dives and extended flight time observed during these overnight trips suggested that birds either experienced poor foraging conditions or exploited more distant, yet more profitable prey patches. Conversely, birds that stayed at sea for less than 1 day had relatively consistent activity patterns. Most of these birds (88%) foraged actively at the beginning and at the end of the foraging trip. These feeding bouts were separated by protracted periods of sitting on the sea surface. Such resting periods probably allow birds to digest the food ingested during the first part of the foraging trip, so they initially feed themselves, and then obtain food for their chick on the way back to the breeding site. 相似文献
953.
L-Glutamate and Insulin Enhance Glycogen Synthesis in Cultured Astrocytes from the Rat Brain Through Different Intracellular Mechanisms 总被引:1,自引:0,他引:1
The effects of L-glutamate and insulin on glycogen synthesis in astrocytes were examined. L-Glutamate and insulin both stimulated glycogen synthesis in primary cultures of rat astrocytes in a dose-dependent manner, as measured by the incorporation of 14C from [14C]glucose into glycogen. D-Aspartate also increased the incorporation of 14C into glycogen. When insulin and L-glutamate were added together, the glycogen synthesis as well as glycogen content of the cells was additively increased. Wortmannin, an inhibitor of phosphatidylinositol 3-kinase, had little effect on glycogen synthesis induced by L-glutamate, whereas it suppressed the insulin-induced glycogen synthesis. These results suggest that the insulin- and L-glutamate-induced glycogen syntheses are mediated by different intracellular mechanisms. In fact, insulin stimulated the conversion of glycogen synthase b to glycogen synthase a, which was suppressed by wortmannin. L-Glutamate and D-aspartate, however, did not increase the level of glycogen synthase a activity. By contrast, L-glutamate increased 2-deoxy-D-[3H]glucose uptake by the astrocytes, whereas insulin did not affect the uptake. These results suggest that insulin stimulates glycogen synthesis in astrocytes by activating glycogen synthase, which is dependent on a wortmannin-sensitive signaling pathway. L-Glutamate, however, enhances the glucose uptake, which contributes to the increase in glycogen synthesis in the cells. 相似文献
954.
Glutathione S-transferases (GSTs; EC 2.5.1.18
[EC]
) in sarcocarptissue of pumpkin (Cucurbita maxima Duch.) fruit and in callusinduced from the tissue were examined. The specific activityof GST in the callus was 6.9-fold higher than that in the tissue.The specific activity in the callus remained constant duringcultivation. Column chromatography on DEAE-cellulose, hydroxylapatite,and S-hexylglutathione-agarose was used to fractionate solubleproteins that were precipitated by ammonium sulfate at 30% to70% saturation from homogenates of the sarcocarp tissue of pumpkinfruit and the callus and GST activity was monitored. Two andseven isozymes of GST were identified in the tissue and in thecallus, respectively. Furthermore, column chromatography onSephadex G-200 and SDS-polyacrylamide gel electrophoresis, indicatedthat these GST isozymes were homo- and heterodimers of subunitsof Mr 22,000 (Puga), and 23,000 (Pugb), 24,000 (Pugc) or 24,500(Pugd). Puga and Pugb were predominant in the sarcocarp tissueand in the callus, respectively. Puga, Pugb, Pugc and Pugd hadacidic pI values of 5.45, 5.00, 5.35 and 5.75, respectively.Rabbit antiserum against Pugb did not cross-react with the threeother subunits of GST during immunoblotting. (Received July 15, 1993; Accepted December 14, 1993) 相似文献
955.
956.
Aya Fukui-Miyazaki Shigeki Kamitani Masami Miyake Yasuhiko Horiguchi 《BMC microbiology》2010,10(1):247
Background
Bordetella dermonecrotic toxin (DNT) causes the turbinate atrophy in swine atrophic rhinitis, caused by a Bordetella bronchiseptica infection of pigs, by inhibiting osteoblastic differentiation. The toxin is not actively secreted from the bacteria, and is presumed to be present in only small amounts in infected areas. How such small amounts can affect target tissues is unknown. 相似文献957.
Intratumoral heterogeneity and inverse correlation between expression of E-cadherin and collagenase type IV in human gastric carcinomas 总被引:2,自引:0,他引:2
958.
Motohiko Hikuma Hiroshi Matsuoka Minoru Takeda Yasuhiko Tonooka 《Biotechnology Techniques》1993,7(3):231-236
Summary The microbial electrode consisted of immobilizedPseudomonas aeruginosa (ATCC 10145) and a carbon dioxide gas-sensing probe. The calibration curve was linear from 20 to 200 mg/l of nitrate with
a slope of 30 mv/decade. A measurement was made within 10 min and the cycle time was 30 min. The effects of various experimental
conditions on the electrode response were discussed. The electrode was applied to samples from a wastewater treatment plant. 相似文献
959.
Wataru Motomura Takayuki Yoshizaki Katsuki Ohtani Toshikatsu Okumura Mituko Fukuda Jun Fukuzawa Kenichiro Mori Seong-Jae Jang Naoki Nomura Itsuro Yoshida Yasuhiko Suzuki Yutaka Kohgo Nobutaka Wakamiya 《The journal of histochemistry and cytochemistry》2008,56(3):243-252
We have recently identified a novel collectin, CL-K1, that may play a role in innate immunity as a member of the collectin family. In this study using mice, we investigated the tissue distribution of CL-K1 for better understanding of its pathophysiological relevance. Real-time PCR analyses demonstrated that CL-K1 mRNA was expressed in all tissues tested. Immunohistochemical analyses demonstrated that CL-K1 was expressed in proximal tubules of kidney, in mucosa of the gastrointestinal tract, and in bronchial glands of bronchioles similar to the localization of SP-A and SP-D in these pulmonary structures. Immunohistochemistry also showed that CL-K1 was highly expressed in hepatocytes around the central veins in liver, which suggests that murine CL-K1 may be mainly produced in the liver and secreted into the blood stream as is human CL-K1. CL-K1 was especially detected in vascular smooth muscle in several types of tissues. In addition, it was also expressed in intestinal Paneth cells, in mesangial cells of kidney, in pancreatic islet D cells, and in neurons of the brain. It is of interest that this profile of CL-K1 expression is unique among the collectins. Together these histological findings may be useful for understanding the biological function of this novel collectin. 相似文献
960.