全文获取类型
收费全文 | 8257篇 |
免费 | 497篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 160篇 |
妇产科学 | 125篇 |
基础医学 | 1197篇 |
口腔科学 | 204篇 |
临床医学 | 505篇 |
内科学 | 2214篇 |
皮肤病学 | 151篇 |
神经病学 | 670篇 |
特种医学 | 329篇 |
外科学 | 1177篇 |
综合类 | 43篇 |
一般理论 | 3篇 |
预防医学 | 368篇 |
眼科学 | 161篇 |
药学 | 627篇 |
中国医学 | 20篇 |
肿瘤学 | 793篇 |
出版年
2023年 | 68篇 |
2022年 | 167篇 |
2021年 | 237篇 |
2020年 | 150篇 |
2019年 | 169篇 |
2018年 | 212篇 |
2017年 | 151篇 |
2016年 | 174篇 |
2015年 | 241篇 |
2014年 | 276篇 |
2013年 | 299篇 |
2012年 | 510篇 |
2011年 | 493篇 |
2010年 | 285篇 |
2009年 | 259篇 |
2008年 | 443篇 |
2007年 | 392篇 |
2006年 | 415篇 |
2005年 | 410篇 |
2004年 | 389篇 |
2003年 | 346篇 |
2002年 | 358篇 |
2001年 | 226篇 |
2000年 | 221篇 |
1999年 | 208篇 |
1998年 | 93篇 |
1997年 | 88篇 |
1996年 | 65篇 |
1995年 | 46篇 |
1994年 | 41篇 |
1993年 | 38篇 |
1992年 | 137篇 |
1991年 | 127篇 |
1990年 | 106篇 |
1989年 | 124篇 |
1988年 | 80篇 |
1987年 | 75篇 |
1986年 | 80篇 |
1985年 | 76篇 |
1984年 | 68篇 |
1983年 | 52篇 |
1982年 | 24篇 |
1979年 | 51篇 |
1978年 | 25篇 |
1977年 | 31篇 |
1976年 | 24篇 |
1974年 | 26篇 |
1971年 | 25篇 |
1970年 | 25篇 |
1967年 | 23篇 |
排序方式: 共有8815条查询结果,搜索用时 15 毫秒
11.
Neoplastic angioendotheliosis has rarely been described as a respiratory disease. A patient is described with pulmonary vascular involvement induced by neoplastic angioendotheliosis in pulmonary vessels. 相似文献
12.
The cell body size (cross-sectional area) of S100-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG). About a half of neurons exhibited S100-immunoreactivity (-ir) in the DRG (44.0%) and TG (59.0%). DRG neurons with cell bodies >1200 μm2 mostly exhibited S100-ir (96.5%), whereas S100-ir DRG neurons <600 μm2 were rare (8.0%). 36.6% of DRG neurons in the cell size range 600–1200 μm2 showed the ir. TG neurons >800 μm2 mostly exhibited S100-ir (93.1%), whereas those <400 μm2 were devoid of it (positive cells 10.5%). 58.3% of TG cells in the range 400–800 μm2 contained S100-ir. Double-immunofluorescence method revealed the co-expression of S100 and other calcium-binding proteins. Parvalbumin-ir neurons mostly exhibited S100-ir in the DRG (97.4%) and TG (97.0%). The co-expression of S100 and calbindin D-28k was very rare in the DRG, because the DRG contained few calbindin D-28k-ir neurons. Unlike in the DRG, numerous neurons co-expressed S100- and calbindin D-28k-ir in the TG. Most calbindin D-28k-ir TG neurons were also immunoreactive for S100 (90.7%). Sub-populations of calretinin (CR)-ir neurons co-expressed S100-ir in both the DRG (68%) and TG (50.0%). Virtually all CR-ir neurons >1400 μm2 co-expressed S100-ir in the DRG (100%) and TG (95.9%). CR-ir neurons <800 μm2 were rarely exhibited S100-ir (DRG 18.0%, TG 21.9%). 71.3 and 60.5% of CR-ir neurons in the range 800–1400 μm2 co-expressed S100-ir in the DRG and TG, respectively. The present study indicates that S100 is closely correlated to the primary neuronal cell size in the DRG and TG. 相似文献
13.
14.
We report a case of extraadrenal pheochromocytoma of Zuckerkandl imaged by dynamic magnetic resonance imaging (dynamic MRI) with a 0.5 tesla (T) machine. The dynamic MRI proved useful in disclosing the tumor clearly because of strong enhancement in its early phase. This case has the advantages of dynamic computed tomography (dynamic CT) as well as of T2-weighted spin-echo (SE) MR images. 相似文献
15.
K Ohtsuka K Tsuji Y Nakagawa H Ueda O Ozawa T Uchida T Ichikawa 《Journal of nutritional science and vitaminology》1990,36(3):265-276
O-beta-D-Galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl-(1----4)-D- glucopyranose (designated as 4'GL) is produced from lactose by Cryptococcus laurentii. The influence of chronic ingestion of 4'GL on body weight gain, organ weight, serum lipids, and liver lipids was investigated in rats. The body weight gains of the 5% and 10% 4'GL-diet groups were higher than that of the control group. Food intake and fecal dry weight were significantly increased (p less than 0.05) by 4'GL feeding. The 4'GL diet produced a significant increase (p less than 0.01) in the wet weight and contents of both the cecum and the colon. However, no significant increase was observed in the weight of the stomach, small intestine, liver, or other organs. The effects of 4'GL on serum and liver lipid levels were not observed in this experiment. The digestion of 4'GL was measured in vitro using the artificial gastric juice, alpha-amylase of human saliva, alpha-amylase of hog pancreas, and mucosa of rat intestine. 4'GL was not hydrolyzed by these enzymes. Long-term ingestion of 4'GL did not cause any induction of 4'GL hydrolyzing enzyme activity in the rat small intestine. 相似文献
16.
The rearrangement of terminations from the bed nucleus of stria terminalis (BST) was examined in the medial amygdaloid nucleus (MAN) at 2 months following the lesion of the accessory olfactory bulb (AOB) using an electron microscopy and degeneration study. At 2 days following a BST lesion, the number of degenerating synapses was 0.7 ± 0.1 (mean±S.E.M.) per unit area (2500 μm2 in the molecular layer, and 3/0 ± 0.3 in the cellular part. At 2 months after an AOB lesion, the degenerating synapses from the AOB had completely disappeared from the MAN. The BST was then lesioned at 2 months after the AOB lesion and, 2 days following this BST lesion, the degenerating synapses were counted in MAN. The numbers observed were 3.3 ± 0.6 per unit area in the molecular layer and 4.5 ± 0.4 in the cellular part. Therefore, the number of these degenerating synapses increased significantly within the molecular layer, though, in the cellular part the number of synapses was not significantly elevated over control. No differences in postsynaptic profiles (ratio of synapses on dendritic spine to dendritic shaft) were observed after the AOB lesion. These results indicate that the BST fibers formed new synapses in the molecular layer following the denervation of AOB fibers. The possibility of new synapse formation by other afferent fibers in addition to the AOB fibers is discussed as is the relationship between lesion induced synaptic reorganization and functional recovery after injury. 相似文献
17.
T Ichikawa J C Lamb P I Christensson B Hartley-Asp J T Isaacs 《Cancer research》1992,52(11):3022-3028
Linomide (N-phenylmethyl-1,2-dihydro-4-hydroxyl-1-methyl-2-oxo-quinoline-3- carboxamide) is a quinoline 3-carboxamide which previously has been demonstrated to produce immunomodulator and antitumor effects when given in vivo. To test the possible antitumor effects of linomide against prostatic cancers, rats bearing five distinct Dunning R-3327 rat prostatic cancer sublines were treated daily with i.p. injections of linomide. These studies demonstrated that linomide has a reproducible antitumor effect against all of the prostatic cancers tested regardless of their growth rate, degree of morphologic differentiation, metastatic ability, or androgen responsiveness. This antitumor effect is observed only in vivo, not in vitro, and involves a cytotoxic response of the prostatic cancer cells. This cytotoxic response results in the retardation of the growth rate (i.e., increased tumor volume doubling time) of primary prostatic cancers and in metastatic lesions. Linomide's growth retardation is reversible, and thus continuous daily treatment with linomide is required for maximal antitumor response. Pretreatment of rats with linomide before tumor inoculation has no effect in addition to that produced by initiating linomide treatment at the time of tumor inoculation. No enhancement of either natural killer cell number or natural killer cell cytotoxic activity is induced by linomide treatment in the tumor-bearing rats. In addition, depletion of natural killer cell activity via injections of asialo-GM1 antiserum does not prevent the antitumor effects of linomide in vivo. Likewise, the antitumor effects of linomide are also produced in prostatic cancer-bearing athymic nude rats. These results suggest that the requirement for host involvement in the antitumor effects of linomide against rat prostatic cancers may involve both immune and nonimmune host mechanism(s) (e.g., antiangiogenesis). 相似文献
18.
19.