全文获取类型
收费全文 | 45425篇 |
免费 | 2404篇 |
国内免费 | 152篇 |
专业分类
耳鼻咽喉 | 613篇 |
儿科学 | 2735篇 |
妇产科学 | 750篇 |
基础医学 | 5304篇 |
口腔科学 | 1182篇 |
临床医学 | 3355篇 |
内科学 | 8463篇 |
皮肤病学 | 1185篇 |
神经病学 | 2739篇 |
特种医学 | 1452篇 |
外科学 | 7002篇 |
综合类 | 1354篇 |
一般理论 | 21篇 |
预防医学 | 2245篇 |
眼科学 | 1662篇 |
药学 | 4403篇 |
1篇 | |
中国医学 | 366篇 |
肿瘤学 | 3149篇 |
出版年
2023年 | 368篇 |
2022年 | 1062篇 |
2021年 | 1817篇 |
2020年 | 979篇 |
2019年 | 1156篇 |
2018年 | 1574篇 |
2017年 | 1155篇 |
2016年 | 1499篇 |
2015年 | 1495篇 |
2014年 | 2232篇 |
2013年 | 2536篇 |
2012年 | 3598篇 |
2011年 | 3575篇 |
2010年 | 2104篇 |
2009年 | 1681篇 |
2008年 | 2396篇 |
2007年 | 2451篇 |
2006年 | 2218篇 |
2005年 | 1973篇 |
2004年 | 1825篇 |
2003年 | 1566篇 |
2002年 | 1331篇 |
2001年 | 831篇 |
2000年 | 743篇 |
1999年 | 632篇 |
1998年 | 305篇 |
1997年 | 242篇 |
1996年 | 237篇 |
1995年 | 206篇 |
1994年 | 174篇 |
1993年 | 146篇 |
1992年 | 370篇 |
1991年 | 354篇 |
1990年 | 377篇 |
1989年 | 347篇 |
1988年 | 288篇 |
1987年 | 253篇 |
1986年 | 242篇 |
1985年 | 231篇 |
1984年 | 179篇 |
1983年 | 123篇 |
1982年 | 69篇 |
1981年 | 78篇 |
1980年 | 71篇 |
1979年 | 112篇 |
1978年 | 74篇 |
1977年 | 92篇 |
1976年 | 69篇 |
1973年 | 63篇 |
1971年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
31.
We report a seven-year-old girl who presented with a sudden tumor apoplexy due to a parasagittal hemangiopericytoma. Following tumor excision, the child was noted to have bilateral optic nerve dysfunction and progressive papilledema, despite rapid overall neurological improvement. Based on the clinical features, we feel that this case represents an unusual form of visual deterioration related to impaired CSF absorption somehow precipitated by the acute tumour apoplexy. This unusual case of blindness responded significantly to CSF shunting. Several reports exist describing raised intracranial pressure with papilledema caused by nonthrombotic sinus occlusion due to tumors in proximity to the posterior superior sagittal sinus, torcular herophili and the jugular outlet. Communicating hydrocephalus, pseudotumor syndrome or intracranial venous sinus obstruction should be considered when otherwise inexplicable visual loss coexists with optic nerve dysfunction and papilledema. We emphasize the importance of a thorough search for the cause of visual loss. 相似文献
32.
33.
34.
35.
36.
Estimation of T and B lymphocytes was done in 50 patients of enteric fever, 50 duration matched non enteric fever patients and 50 normal healthy individuals. The difference in both early and late rosette forming T lymphocytes was found to be statistically significant in enteric versus non-enteric patients. Significant difference was also observed in enteric versus normal individuals in case of late rosette forming T lymphocytes. 相似文献
37.
38.
Even though a variety of adverse effects caused by sweeteners, flavorings, and dyes in susceptible individuals have been reported, there is no good single reference with information about these substances in pediatric antimicrobials. Data on sweeteners, flavorings, and dyes in 91 antimicrobial preparations were collected. Sucrose was present in 74 (85%) of 87 preparations, followed by saccharin in 30 (34%) preparations. Mannitol, lactose, and sorbitol were each present in 7 preparations. None of the preparations were free of sweeteners. Thirty-four (37%) of 91 preparations did not specify the flavoring content. While cherry was the most common flavoring used, there were 25 other flavorings. Thirteen different dyes and coloring agents were used in these antimicrobials. Red dye no. 40 was present in 45% of preparations. Tables detailing sweeteners, flavorings, and dyes in different groups of antimicrobials (amoxicillin, ampicillin, cephalosporins, erythromycin, penicillins, sulfonamides, and others) and adverse effects reported with these inert ingredients are presented. These tables should be helpful to physicians in selecting an antimicrobial containing a different sweetener and/or dye when an adverse reaction occurs. 相似文献
39.
The genotoxic effect of an extract of smoke-dried meat was assayed by employing in vivo sperm head shape abnormality. A significant dose responsive mutagenic effect was observed using the sperm head shape abnormality test. The result indicates that higher doses i.e., 100 and 200 mg/kg body wt. of smoke meat extract, significantly induced sperm head shape abnormality as compared to lower doses i.e., 20 mg/kg body wt. and control. 相似文献
40.
Mitogenic, chemotactic, and synthetic responses of rat periodontal ligament fibroblastic cells to polypeptide growth factors in vitro. 总被引:9,自引:0,他引:9
The mitogenic, chemotactic, and synthetic responses of rat periodontal ligament (PDL) fibroblastic cells to epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), recombinant human platelet-derived growth factor (rhPDGF)-AB, rhPDGF-BB, natural (n) PDGF-AB, and insulin-like growth factor-I (IGF-I) were examined in vitro using PDL cells obtained from the coagulum of healing tooth sockets. PDGFs and IGF-I have potent and comparable mitogenic effects on PDL fibroblastic cells. The maximum mitogenic effect of PDGFs was observed at the concentration of 10 ng/ml, whereas that of IGF-I was seen at concentrations higher than 100 ng/ml. In contrast, EGF induced moderate, and TGF-beta inhibitory mitogenic responses. The combination of rhPDGF-AB with either EGF or TGF-beta demonstrated comparable mitogenic potency, equivalent to the level of PDGF alone regardless of the mitogenic effect of other growth factors. The combination of rhPDGF-AB and IGF-I, however, showed a synergistic effect revealing the highest mitogenic effect among all individual growth factors as well as any combinations of the growth factors tested. Similarly, PDL fibroblastic cells demonstrated strong chemotactic responses to both IGF-I and PDGFs. The maximum effect was observed by IGF-I at concentrations higher than 10 ng/ml, followed by rhPDGF-BB at 0.1 ng/ml, rhPDGF-AB and nPDGF at concentrations ranging from 0.1 to 1 ng/ml. TGF-beta revealed no, and EGF slightly increased, chemotactic effects. IGF-I slightly enhanced the synthesis of total protein, whereas other factors had no significant effect. However, both rhPDGF-AB and TGF-beta stimulated collagen synthesis. On the other hand, IGF-I showed no effect on collagen synthesis, while EGF suppressed collagen synthesis. These findings suggest that rhPDGF-BB and IGF-I stimulate proliferation and chemotaxis of PDL fibroblastic cells. In addition, the combination of these growth factors further increases the mitogenic effect. rhPDGF-AB also stimulates collagen synthesis by PDL fibroblastic cells. Thus, rhPDGF-BB and IGF-I may have important roles in promotion of PDL healing, and consequently, may be useful for clinical application in periodontal regenerative procedures. 相似文献