全文获取类型
收费全文 | 2276篇 |
免费 | 99篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 39篇 |
妇产科学 | 38篇 |
基础医学 | 254篇 |
口腔科学 | 38篇 |
临床医学 | 110篇 |
内科学 | 430篇 |
皮肤病学 | 12篇 |
神经病学 | 241篇 |
特种医学 | 164篇 |
外科学 | 490篇 |
综合类 | 1篇 |
预防医学 | 51篇 |
眼科学 | 34篇 |
药学 | 172篇 |
中国医学 | 1篇 |
肿瘤学 | 304篇 |
出版年
2022年 | 15篇 |
2021年 | 21篇 |
2019年 | 12篇 |
2018年 | 37篇 |
2017年 | 28篇 |
2016年 | 32篇 |
2015年 | 22篇 |
2014年 | 48篇 |
2013年 | 61篇 |
2012年 | 77篇 |
2011年 | 118篇 |
2010年 | 61篇 |
2009年 | 45篇 |
2008年 | 100篇 |
2007年 | 121篇 |
2006年 | 110篇 |
2005年 | 118篇 |
2004年 | 150篇 |
2003年 | 149篇 |
2002年 | 154篇 |
2001年 | 62篇 |
2000年 | 63篇 |
1999年 | 55篇 |
1998年 | 40篇 |
1997年 | 31篇 |
1996年 | 35篇 |
1995年 | 28篇 |
1994年 | 31篇 |
1993年 | 19篇 |
1992年 | 50篇 |
1991年 | 54篇 |
1990年 | 43篇 |
1989年 | 35篇 |
1988年 | 27篇 |
1987年 | 29篇 |
1986年 | 28篇 |
1985年 | 23篇 |
1984年 | 21篇 |
1983年 | 11篇 |
1980年 | 15篇 |
1979年 | 19篇 |
1978年 | 14篇 |
1976年 | 10篇 |
1974年 | 16篇 |
1973年 | 11篇 |
1972年 | 15篇 |
1971年 | 11篇 |
1970年 | 11篇 |
1969年 | 15篇 |
1966年 | 10篇 |
排序方式: 共有2386条查询结果,搜索用时 15 毫秒
1.
2.
Kimiaki Hashiguchi Takato Morioka Fumiaki Yoshida Yasushi Miyagi Shinji Nagata Ayumi Sakata Tomio Sasaki 《Seizure》2007,16(3):238-247
OBJECTIVE: To investigate the correlation between scalp-recorded electroencephalographic (EEG) and electrocorticographic (ECoG) activities during ictal periods. METHODS: Simultaneous EEG and ECoG recordings with chronic subdural electrodes were performed in eight patients with partial epilepsy. RESULTS: In two cases where the ictal ECoG discharges originated in deep brain structures such as the hippocampus and interhemispheric surface of the frontal lobe, ictal discharges could not be detected on EEG until they expanded to the cortex of convexity. In four cases, the ictal onset zones were located in the lateral convexity. When synchronous or near synchronous ictal ECoG discharges with amplitudes of 200-2000muV were recorded on more than 8-15cm(2) of cortex, corresponding discharges were recorded on EEG in these four cases. However, in a case of frontal lobe epilepsy, asynchronous ictal ECoG discharges were recorded on 10 electrodes of convexity but no ictal EEG activity was recorded. Furthermore, in two frontal lobe epilepsy cases, ictal EEG discharges did not always reflect the ictal ECoG spike, but occasionally reflected slow background ECoG activity around the ictal discharges. CONCLUSIONS: Multiple factors such as the width of the cortical area involved, amplitude of ictal discharges and degree of synchronization of electrical potentials play important roles in the appearance of ictal EEG recordings, and the relationship between ictal EEG and ECoG is not straightforward. 相似文献
3.
4.
5.
Hiroki Sato Atsushi Watanabe Tamotsu Yamaguchi Nobuhiro Harada Akihiko Yamauchi Satomi Inoue Tomio Abe 《Annals of thoracic and cardiovascular surgery》2005,11(1):41-43
Intralobar pulmonary sequestration associated with asymptomatic aspergillosis is a rare case. We describe the case of a 65-year-old woman with intrapulmonary sequestration, anomalous systemic arterial supply to the left lower lobe and aspergillosis who underwent left lower lobectomy and ligation of an anomalous artery by Video-Assisted Thoracoscopic surgery (VATS). Pathological examination showed the parenchymal distortion and chronic inflammation. Aspergillus were found in the cyst. VATS lobectomy for intralobar pulmonary sequestration is a safe and valid procedure. 相似文献
6.
Long-term lithium treatment causes serotonin receptor down-regulation via serotonergic presynapses in rat brain 总被引:2,自引:0,他引:2
The effects of lithium treatment on serotonin (5-HT) receptors in rat frontal cortex and hippocampus were investigated. Long-term lithium treatment strongly blocked 5-hydroxytryptophan-induced head twitches, while acute lithium administration by itself induced head twitches in rats, and ketanserin blocked this acute lithium action. Long-term administration of lithium decreased the number of not only 5-HT2 receptors in the frontal cortex but also 5-HT1 and 5-HT2 receptors in the hippocampus in rats. Decreases in 3H-5-HT binding to hippocampal 5-HT1 receptors and 3H-spiperone binding to frontal cortical 5-HT2 receptors, caused by chronic lithium treatment, were abolished by co-administration of p-chlorophenylalanine, and were enhanced by co-administration with methiothepin. The turnover of 5-HT in either frontal cortex or hippocampus was facilitated by lithium, and co-administered methiothepin enhanced this facilitation. These results suggest that long-term lithium treatment causes the down-regulation of postsynaptic 5-HT1 and 5-HT2 receptors, in part probably through its action on presynaptic nerve terminals. 相似文献
7.
Yuko Takeyama Keiki Ogino Hiroyuki Segawa Haruo Kobayashi Taizo Uda Tatsuya Houbara 《Basic & clinical pharmacology & toxicology》1995,76(1):50-55
Abstract: The effects of zinc on the production of active oxygen species were investigated in rat neutrophils by chemilumi-nescence and spectrophotometric assays. The luminol-dependent chemiluminescence in unstimulated neutrophils showed a single peak. Zinc at concentrations lower than 0.1 mM augmented the intensity of chemiluminescence and showed a bimodal pattern, the first peak of which was inhibited by superoxide dismutase and catalase, while the second peak disappeared in the presence of catalase, but was unaffected by superoxide dismutase. At the same concentrations of zinc, O2? and H2O2 production increased, but secretion and activity of myeloperoxidase were not affected. Zinc at 0.1 mM enhanced the second peak of luminol-dependent chemiluminescence, and concomitantly O2? and H2O2 production of neutrophils stimulated with formyl-methionyl-leucyl-phenylalanine. Homogenized neutrophils showed a bimodal pattern on induction by zinc, the second peak of which was inhibited slightly by catalase and completely by sodium azide, but was not inhibited by superoxide dismutase. Zinc-induced O2? production was inhibited by pertussis toxin, but was not significantly inhibited by a protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), or a calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7). These results suggest that zinc can augment luminol-dependent chemiluminescence by increasing O2? production through the classical signal transduction pathway, and by increasing H2O2 not via O2?. 相似文献
8.
Yutaka Yonemura Masataka Segawa Hisashi Matsumoto Kouichirou Tsugawa Itasu Ninomiya Luis Fonseca Takashi Fujimura Kazuo Sugiyama Kouichi Miwa Itsuo Miyazaki 《Surgery today》1994,24(6):488-493
Because gastric cancers located in the upper third of the stomach are difficult to detect at an early stage, the surgical results remain poor. We performed R4 gastrectomy as a radical procedure for 25 patients, involving complete resection of the latero-aortic and interaorticovenous lymph modes above and below the left renal vein, in combination with the ordinary R2 or R3 gastrectomy (the R4 group). These patients were compared with 156 others who underwent R2 gastrectomy alone (the R2 group). There were no significant differences in operation time, blood loss, or the incidence of complications between the two groups; however, when the survival rates of the patients with tumors invading beyond the subserosa were compared, the 5-year survival rate was found to be significantly higher in the R4 group than in the R2 group. Furthermore, in patients with para-aortic nodal involvement, a significant survival advantage was observed in the R4 group, as compared with the R2 group. These results suggest that the R4 gastrectomy is a rational approach for patients with advanced gastric cancer located in the upper third of the stomach. 相似文献
9.
The effect of the experimental antiepileptic drug zonisamide (1,2-benzisoxazole-3-methanesulfonamide, ZNS) on the trigeminal complex of cats was compared with the effect of established antiepileptic drugs. Intravenous administration of 10-40 mg/kg ZNS significantly depresses descending excitatory mechanisms, as well as segmental and descending inhibitory mechanisms, but has only a minor effect on segmental excitatory mechanisms. This spectrum of activity is similar to that of valproate, and suggests that ZNS should also be a broad-spectrum antiepileptic drug. In agreement with our experimental observations, it has been found that ZNS is effective against complex partial, generalized tonic clonic, and myoclonic seizures. The antiepileptic profile of ZNS in conventional screening tests resembles that of carbamazepine (CBZ) and phenytoin. However, CBZ exacerbates rather than prevents myoclonic seizures. Our experimental model thus provides a more accurate prediction of ZNS's clinical spectrum of activity. The relationship of these findings to the mechanism of action of antiepileptic drugs is discussed. 相似文献
10.
The effects of chronic treatment with imipramine or lithium on serotonin (5-HT) receptor subtypes were analyzed in the frontal cortex, hippocampus and choroid plexus of rat brain by quantitative receptor autoradiographic procedures, using radioligands [3H]-5-HT, [3H]-8-hydroxy-2-(di-n-propylamino)tetralin ([3H]-8-OH-DPAT), [125I]-iodocyanopindolol ([125I]-CYP), [3H]-mesulergine and [125I]-7-amino-8-iodo-ketanserin ([125I]-ketanserin) or [3H]-spiperone. Chronic i.p. administration of imipramine (20 mg/kg/day for 21 days) decreased the densities of 5-HT1, 5-HT1A, 5-HT1C and 5-HT2 sites in the frontal cortex, hippocampus and choroid plexus. Lithium (2 mEq/kg/day for 21 days) also decreased the densities of 5-HT1, 5-HT1C and 5-HT2 sites in the frontal cortex, and the densities of those including 5-HT1A sites in the hippocampus and choroid plexus. Imipramine and lithium very markedly decreased the density of 5-HT1C sites in the choroid plexus. We propose that methods employing quantitative receptor autoradiographic analysis can be used to characterize and understand the local effects of these drugs on 5-HT receptor subtypes. 相似文献