全文获取类型
收费全文 | 228085篇 |
免费 | 18682篇 |
国内免费 | 8124篇 |
专业分类
耳鼻咽喉 | 1727篇 |
儿科学 | 3152篇 |
妇产科学 | 2512篇 |
基础医学 | 35552篇 |
口腔科学 | 3678篇 |
临床医学 | 15837篇 |
内科学 | 39945篇 |
皮肤病学 | 3293篇 |
神经病学 | 16409篇 |
特种医学 | 4928篇 |
外国民族医学 | 55篇 |
外科学 | 16066篇 |
综合类 | 30023篇 |
现状与发展 | 20篇 |
一般理论 | 6篇 |
预防医学 | 11384篇 |
眼科学 | 2256篇 |
药学 | 36124篇 |
48篇 | |
中国医学 | 11635篇 |
肿瘤学 | 20241篇 |
出版年
2024年 | 607篇 |
2023年 | 4298篇 |
2022年 | 9469篇 |
2021年 | 11262篇 |
2020年 | 8569篇 |
2019年 | 7955篇 |
2018年 | 7592篇 |
2017年 | 7312篇 |
2016年 | 7217篇 |
2015年 | 8489篇 |
2014年 | 13124篇 |
2013年 | 14538篇 |
2012年 | 12908篇 |
2011年 | 14853篇 |
2010年 | 12150篇 |
2009年 | 12414篇 |
2008年 | 12036篇 |
2007年 | 11102篇 |
2006年 | 9909篇 |
2005年 | 8730篇 |
2004年 | 7359篇 |
2003年 | 6567篇 |
2002年 | 5190篇 |
2001年 | 4405篇 |
2000年 | 3651篇 |
1999年 | 3264篇 |
1998年 | 2978篇 |
1997年 | 2780篇 |
1996年 | 2435篇 |
1995年 | 2195篇 |
1994年 | 1963篇 |
1993年 | 1693篇 |
1992年 | 1401篇 |
1991年 | 1331篇 |
1990年 | 1102篇 |
1989年 | 933篇 |
1988年 | 878篇 |
1987年 | 756篇 |
1986年 | 670篇 |
1985年 | 1307篇 |
1984年 | 1405篇 |
1983年 | 958篇 |
1982年 | 989篇 |
1981年 | 854篇 |
1980年 | 696篇 |
1979年 | 625篇 |
1978年 | 443篇 |
1977年 | 334篇 |
1976年 | 385篇 |
1975年 | 279篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
P. Kiviskk W. Tian S. Fredrikson H. Link M. Sderstrm 《European journal of neurology》1997,4(5):460-467
Beta-interferon (IFN-β) is a promising treatment in multiple sclerosis (MS), reducing the exacerbation rate and MRI lesion burden, as well as the disease progression in relapsing-remitting MS. IFN-β was originally defined by its antiviral effects, but the interest has recently been focused on its immunomodulatory properties. Myelin basic protein (MBP) is one of several autoantigens considered to be the target for autoaggressive immune responses, which eventually might lead to the development of MS. To study in-vitro effects of IFN-β1b on MBP induced cytokine expression, mRNA for the Th1 cytokines IFN-γ and TNF-α, the Th2 related IL-4 and IL-6, the cytolytic perforin and the immune response downregulating TGF-β was measured with in situ hybridization after culture of blood mononuclear cells (MNC) in the presence and absence of MBP. Numbers of cells expressing IFN-γ, TNF-α, perforin and IL-4 mRNA were significantly suppressed after culture with 10 U/ml IFN-β1b. No such effect was seen on MBP induced IL-6 or TGF-β mRNA expression. These observations suggest that one of the major effects of IFN-β1b is the induction of a shift in the cytokine mRNA profile towards a more immunosuppressive pattern. In parallel in vitro tests, the control substance dexametasone (40 μg/ml) reduced the numbers of cells expressing mRNA for all cytokines under study with the exception of TGF-β, to an extent equal to or even more pronounced than IFN-β1b. 相似文献
92.
Goichi Yotsumoto Koki Tanaka Naoki Ishizaki Akira Ikoma Sumihiro Kawashima Akira Taira 《Surgery today》1997,27(7):657-660
We report herein a case of spontaneous subcapsular hepatic hemorrhage which occurred in a 33-year-old woman 1 day after she
had been delivered of her second child by cesarean section following an uneventful pregnancy. She complained of right upper
quadrant pain on the 1st postoperative day, and computed tomography (CT) showed subcapsular low-density masses in both liver
lobes, while extravasation was demonstrated by CO2 intraarterial digital subtraction angiography (IADSA). The hemorrhage was successfully controlled by transcatheter arterial
embolization (TAE). However, on the 3rd day after TAE, an exploratory laparotomy was performed to establish an exact diagnosis
to explain the persistent abdominal pain and abnormal liver function tests. Subcapsular hematomas in both lobes were confirmed
and no visible laceration was present. The patient recovered gradually by spontaneous absorption of the hematomas and was
discharged on the 22nd postoperative day. Spontaneous hepatic hemorrhage associated with pregnancy is a very rare complication,
and establishing a correct diagnosis and initiating appropriate therapy are essential for this life-threatening disease. 相似文献
93.
选择南方热区某特种部队战士52人,分两组分别口服5mgVitB1和VitB2,收集4h尿液,用荧光法进行负荷试验。结果:VitB1组,所测29人中,15人缺乏,9人不足,2人正常,3人充裕;VitB2组,所测23人中,11人缺乏,12人不足,反映该部队全年约5%的发病是由于VitB1、VitB2缺乏不足所致。其原因为膳食摄入不够 相似文献
94.
白细胞介素—2新的功能位点及其中枢镇痛作用 总被引:2,自引:0,他引:2
白细胞介素-2(IL-2)不仅是重要的免疫调节因子,而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标,发现侧脑室注射IL—2能显著提高动物痛阈,并能被纳洛酮所阻断,表示IL-2的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性IL-2实查体仍具有中枢镇痛作用,表明IL—2分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断IL—2的中枢镇痛作用,而不能影响IL—2增殖CTLL-2细胞的作用,提示IL-2发挥镇痛和免疫调节作用可能通过不同的受体途径。IL-2分子中第45位Tyr残基突变为Val后,虽仍保留了免疫活性,但丧失了镇痛功能,表示45位Tyr残基是IL—2发挥中枢镇痛功能的关键残基之一。我们推测IL—2的镇痛功能位点可能在IL—2分子中第45位Tyr残基附近区域。 相似文献
95.
α-L-岩藻糖苷酶测定的临床应用 总被引:1,自引:0,他引:1
研究结果表明AFU测定对肝癌的诊断具有较高的敏感性和特异性,其价值优于AFP,两项指标联合检测可提高阳性检出率。动态监测有利于肝癌的早期诊断、鉴别诊断,并可作为转移、复发的指标,也可用于白血病及卵巢癌的诊断。 相似文献
96.
97.
98.
. R. Kakigi H. Shibasaki T. Lkeda R. Neshige C. Endo Y. Kuroda 《Acta neurologica Scandinavica》1992,85(5):347-352
Pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation were examined in 30 patients with peripheral neuropathies, and the results were compared with clinical sensory findings. Pain SEP findings showed a significant correlation with the clinical impairment of pain sensation, but not with the impairment of deep sensations. In contrast, conventional electrically-stimulated SEPs (electric SEPs) showed a significant correlation with deep sensations, but not with the impairment of pain sensation. Examinations of both pain SEPs and electric SEPs, therefore, are considered to be very useful to evaluate physiological functions of sensory nerves in patients with peripheral neuropathies. 相似文献
99.
S Kimel L O Svaasand M Hammer-Wilson V Gottfried S Cheng E Svaasand M W Berns 《Lasers in surgery and medicine》1992,12(4):432-440
The chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real time. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin-type photosensitizer solution was applied to areas of the CAM, defined by teflon O-rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual-wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 microns (to bring about HPT). Damage to the CAM vasculature, due to combined PDT+HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed. 相似文献
100.