全文获取类型
收费全文 | 6333篇 |
免费 | 359篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 89篇 |
妇产科学 | 52篇 |
基础医学 | 758篇 |
口腔科学 | 89篇 |
临床医学 | 420篇 |
内科学 | 1999篇 |
皮肤病学 | 121篇 |
神经病学 | 545篇 |
特种医学 | 197篇 |
外科学 | 1107篇 |
综合类 | 34篇 |
一般理论 | 2篇 |
预防医学 | 171篇 |
眼科学 | 76篇 |
药学 | 339篇 |
中国医学 | 10篇 |
肿瘤学 | 659篇 |
出版年
2023年 | 45篇 |
2022年 | 45篇 |
2021年 | 184篇 |
2020年 | 94篇 |
2019年 | 132篇 |
2018年 | 162篇 |
2017年 | 126篇 |
2016年 | 156篇 |
2015年 | 187篇 |
2014年 | 233篇 |
2013年 | 263篇 |
2012年 | 387篇 |
2011年 | 413篇 |
2010年 | 205篇 |
2009年 | 187篇 |
2008年 | 335篇 |
2007年 | 362篇 |
2006年 | 303篇 |
2005年 | 329篇 |
2004年 | 300篇 |
2003年 | 274篇 |
2002年 | 274篇 |
2001年 | 193篇 |
2000年 | 175篇 |
1999年 | 169篇 |
1998年 | 82篇 |
1997年 | 59篇 |
1996年 | 70篇 |
1995年 | 38篇 |
1994年 | 35篇 |
1993年 | 38篇 |
1992年 | 101篇 |
1991年 | 70篇 |
1990年 | 59篇 |
1989年 | 70篇 |
1988年 | 67篇 |
1987年 | 66篇 |
1986年 | 47篇 |
1985年 | 52篇 |
1984年 | 44篇 |
1983年 | 36篇 |
1982年 | 17篇 |
1979年 | 29篇 |
1978年 | 16篇 |
1977年 | 27篇 |
1976年 | 14篇 |
1969年 | 13篇 |
1968年 | 17篇 |
1967年 | 15篇 |
1966年 | 13篇 |
排序方式: 共有6727条查询结果,搜索用时 18 毫秒
1.
2.
3.
4.
Salvage of a failed valgus osteotomy for nonunion
of an unstable pertrochanteric fracture is reported.
A valgus intertrochanteric osteotomy was performed for a
failed sliding hip screw fixation of an unstable
pertrochanteric fracture at another institution. Four months
following osteotomy, the fracture was still un-united with
two distal screws of the hip plate broken and a coxa vara
deformity. Reconstruction was performed with a nine-hole
95° angle blade plate and cancellous bone graft, because the
insufficient fixation of the distal fragment was considered to
be the main reason for failure. The osteotomy was healed at
six months post-surgery and the patient reported complete
resolution of symptoms. Intertrochanteric valgus osteotomy
is an effective procedure for mal-union and non-union of
pertrochanteric fracture but stable fixation is required for a
good result. The blade of the angle plate offers good purchase
of the proximal fragment and secures it under rotational
and bending stresses. We recommend that distal fragments
should be fixed with at least seven cortices for this
type of osteotomy. 相似文献
5.
Studies on the mechanisms underlying beta-adrenoceptor-mediated relaxation of rat abdominal aorta. 总被引:1,自引:0,他引:1
Mechanisms underlying beta-adrenoceptor (beta-AR)-mediated vascular relaxation were studied in the isolated rat abdominal aorta. In the endothelium-denuded helical preparations, a non-selective beta-AR agonist isoprenaline elicited a concentration-dependent relaxation. In the absence of beta-AR antagonists, isoprenaline-induced relaxation was not practically affected by an adenylyl cyclase inhibitor SQ 22,536 (300 microM), but was strongly diminished by high-KCl (80 mM). Isoprenaline-induced relaxation in the presence of SQ 22,536 was significantly diminished by iberiotoxin (IbTx, 0.1 microM), but was not affected by 4-aminopyridine (4-AP, 3 mM). Isoprenaline-induced relaxation was not also affected by SQ 22,536 (300 microM) even in the presence of CGP20712A (a beta(1)-selective antagonist) and ICI-118,551 (a beta(2)-selective antagonist) (0.1 microM for each), but was strongly diminished by high-KCl. By contrast, SQ 22,536-resistant, isoprenaline-induced relaxation in the presence of CGP20712A plus ICI-118,551 was not affected by IbTx (0.1 microM), but was inhibited significantly by 4-AP (3 mM). These results suggest that in rat abdominal aortic smooth muscle: 1) both beta(1)-/beta(2)-AR- and beta(3)-AR-mediated relaxations substantially involve cAMP-independent mechanisms; 2) beta(1)-/beta(2)-AR-mediated, cAMP-independent relaxant mechanisms are partly attributed to the large-conductance, Ca (2+)-sensitive K(+) (MaxiK, BK) channel whereas beta(3)-AR-mediated relaxant mechanisms are attributed to K(v) channel. 相似文献
6.
The role of hypertension and antihypertensive drugs in cardiovascular complications was evaluated in 380 elderly people living in the Tokyo Metropolitan Gerontology Center. The subjects were classified into four groups according to the presence or absence of hypertension and their antihypertensive treatment, and followed up prospectively for 5 years from 1979 to 1984. The average age of each group was 74 to 76 years. Cerebrovascular disease was observed in 19.3% of male hypertensives and 10.1% of male normotensives (p = 0.078). The drug treated group revealed no cerebral hemorrhage and less cerebral infarction. This tendency was not observed in females. Ischemic heart disease was prevalent in the drug treated group (10.9% vs 4.5%, p = 0.023) irrespective of blood pressure level. Risk factors such as body mass index, skinfold thickness, serum cholesterol, albumin, creatinine, blood urea nitrogen and uric acid at entry were elevated in the drug treated group. Diuretics were used in 92% of the drug treated group; in 53% as monotherapy and in 39% as combination therapy with other antihypertensive agents. The metabolic effect of diuretics may increase the incidence of ischemic heart disease in the elderly. We might conclude that hypertension in the aged accelerates cerebrovascular complications, and that antihypertensive treatment is effective even in this group. However, the wide use of diuretics could increase the incidence of ischemic heart disease. Careful selection of antihypertensive drugs as well as dose adjustment are needed in the treatment of elderly hypertensives. 相似文献
7.
Hirotaka Koizuml Mikita Morita Shinya Mikaml Eiichi Shibayama Toshiyuki Uchikoshi 《Pathology international》1998,48(2):93-101
The Trk family of tyrosine protein kinase receptors plays a significant role in the development and maintenance of neural tissues. It has been recently shown that Trk receptors are also expressed by a wide range of normal non-neuronal tissues in humans in a cell type-specific manner. In the present study, the expression patterns of TrkA in 337 non-neuronal invasive carcinomas of 15 different human tissues were investigated immunohistochemically. Overall, 133 (39%), 101 (30%) and 103 (31%) tumors exhibited strong, moderate and no TrkA Immunoreactivity, respectively. Esophageal and thyroid carcinomas expressed high levels of TrkA, whereas the levels in gastric and colon cancers were low. TrkA expression was detected not only in carcinomas originating from TrkA-positive normal counterpart tissues, Including the esophagus, breast, lung and uterus, but also in those from TrkA-negative tissues/cells of the thyroid, liver and ovary. Immunostaining for nerve growth factor-β, the specific ligand for TrkA, in esophageal and breast carcinomas demonstrated its immunoreactivity in stromal fibroblasts and some TrkA-expressing tumor cells. These results suggest that paracrine/autocrine regulation via stromal/tumoral NGF-tumoral TrkA interaction may be involved In the growth of certain non-neuronal carcinomas. 相似文献
8.
9.
N. Inotsume M. Nishimura M. Nakano S. Fujiyama K. Sagara T. Sato K. Matsushita Y. Imai H. Matsui 《European journal of clinical pharmacology》1990,38(3):313-314
Summary The effect of haemodialysis on the pharmacokinetics of oral famotidine has been studied in five elderly anuric patients. Famotidine 20 mg was administered in a cross-over design to patients on and not on haemodialysis.The elimination rate constant of haemodialysis (k) was 4.6-fold larger than the systemic elimination rate constant (ke). Although the mean maximum serum concentration of famotidine during haemodialysis (141.5 ng·ml–1) was not significantly lower than that without haemodialysis (195.6 ng·ml–1), the AUC up to 5 h during haemodialysis was significantly decreased to 58.1% of the value without it.The data suggest that famotidine is dialysable by haemodialysis. 相似文献
10.
Kohji Matsushita Kazuo Kitagawa Tomohiro Matsuyama Toshiho Ohtsuki Akihiko Taguchi Kenji Mandai Takuma Mabuchi Yoshiki Yagita Takehiko Yanagihara Masayasu Matsumoto 《Brain research》1996,743(1-2)
The divalent cation zinc has been reported to possess several physiological properties such as blocking apoptotic cell death through an inhibitory effect on Ca2+-Mg2+ endonuclease activity, or modulating the neurotoxicity via glutamate receptor subtypes. In the present study, we investigated the effect of peripherally injected zinc on delayed neuronal death seen in the hippocampus after transient global ischemia, in order to elucidate a possible beneficial role on zinc in ischemic neuronal cell death. Forty-five adult Mongolian gerbils of both sexes underwent transient bilateral clipping of the common carotid arteries for 3 min. In the pretreated animals, ZnCl2 (20 mg/kg) was injected subcutaneously once, 1 h before ischemia (superacute group; n=6) or twice at 24 and 48 h before ischemia (subacute group; n=14). Histological survey was carried out 3 days later by in situ DNA fragmentation method and 4 days later by hematoxylin-eosin staining by semiquantatively counting dead neurons in the CA1 sector. Subacute zinc pre-administration significantly reduced the nuclear damage and subsequent neuronal death; however, superacutely pre-administered zinc did not protect hippocampal neurons against ischemia but it did not aggravate the effect of ischemia, either. The present study suggested that transfer of exogenous zinc into the intracellular space is required for neuroprotection, presumably via the anti-endonuclease activity. 相似文献