全文获取类型
收费全文 | 44609篇 |
免费 | 4780篇 |
国内免费 | 1564篇 |
专业分类
耳鼻咽喉 | 626篇 |
儿科学 | 1209篇 |
妇产科学 | 744篇 |
基础医学 | 3119篇 |
口腔科学 | 1293篇 |
临床医学 | 3330篇 |
内科学 | 9320篇 |
皮肤病学 | 445篇 |
神经病学 | 2037篇 |
特种医学 | 1157篇 |
外国民族医学 | 18篇 |
外科学 | 6251篇 |
综合类 | 5411篇 |
现状与发展 | 5篇 |
一般理论 | 3篇 |
预防医学 | 4095篇 |
眼科学 | 549篇 |
药学 | 2581篇 |
15篇 | |
中国医学 | 1849篇 |
肿瘤学 | 6896篇 |
出版年
2024年 | 112篇 |
2023年 | 1032篇 |
2022年 | 1878篇 |
2021年 | 2482篇 |
2020年 | 2354篇 |
2019年 | 2165篇 |
2018年 | 2103篇 |
2017年 | 1871篇 |
2016年 | 1892篇 |
2015年 | 2037篇 |
2014年 | 3188篇 |
2013年 | 3425篇 |
2012年 | 2392篇 |
2011年 | 2517篇 |
2010年 | 1994篇 |
2009年 | 1916篇 |
2008年 | 2011篇 |
2007年 | 1789篇 |
2006年 | 1541篇 |
2005年 | 1384篇 |
2004年 | 1242篇 |
2003年 | 1272篇 |
2002年 | 1044篇 |
2001年 | 855篇 |
2000年 | 727篇 |
1999年 | 641篇 |
1998年 | 602篇 |
1997年 | 548篇 |
1996年 | 444篇 |
1995年 | 386篇 |
1994年 | 370篇 |
1993年 | 291篇 |
1992年 | 255篇 |
1991年 | 251篇 |
1990年 | 195篇 |
1989年 | 156篇 |
1988年 | 147篇 |
1987年 | 130篇 |
1986年 | 105篇 |
1985年 | 145篇 |
1984年 | 157篇 |
1983年 | 105篇 |
1982年 | 95篇 |
1981年 | 92篇 |
1980年 | 107篇 |
1979年 | 89篇 |
1978年 | 67篇 |
1977年 | 53篇 |
1976年 | 53篇 |
1973年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
本文就加热及同时增加细胞内氧自由基水平对恶性胶质瘤细胞存活、增殖和细胞间隙连结通讯的影响做初步观察。用M.T.T法测定胶质瘤细胞存活率;用Ki-67抗增殖细胞核抗原单克隆抗体,通过免疫组织化学ABC染色分析胶质瘤细胞的增殖活性;用划痕染料示踪技术观察胶质瘤细胞的细胞间隙连结通讯。结果表明,H2O2和3AT能增强加热对胶质瘤细胞存活与增殖的抑制作用,促进胶质瘤细胞间隙连结通讯的改善,存在着明显的剂量和时间效应。实验结果提示,通过内外源性增加胶质瘤细胞内的氧自由基水平,将有助于强化加热治疗胶质瘤效果,并可以减少加热的剂且,降低副作用。 相似文献
12.
Anders Wahlin Lorentz Brinch Per Hrnsten Stein A. Evensen Gunnar
berg Bengt Simonsson Michael Hedenus 《European journal of haematology》1997,58(4):233-240
Abstract: The results of an intensive treatment program for patients 16–60 yr of age with de novo acute myeloid leukemia are presented. The patients were given conventional induction treatment with daunorubicin and cytarabine. Patients not entering complete remission (CR) after 1 course of daunorubicin/cytarabine were given 1 course of amsacrine/etoposide/cytarabine. Those entering complete remission received 3 consolidation courses using mitoxantrone, etoposide, amsacrine and cytarabine. One hundred and eighteen patients were enrolled. Complete remission was attained after 1–2 courses in 90 patients (76%). Another 6 patients reached CR after 3–4 induction courses for a total CR rate of 81%. If feasible, patients were offered either allogeneic or unpurged autologous bone marrow transplantation. Twenty-four patients underwent allogeneic bone marrow transplantation; 15 in first remission, 8 in second remission, 1 in early relapse. Thirty patients below 56 yr of age underwent autologous bone marrow transplantation in first remission. The overall probability of survival at 4 yr was 34%, and for patients below 40 yr of age 50%. Leukemia-free survival was 35% for the whole cohort of patients; 52% for patients below 40 yr of age. Patients undergoing allogeneic or autologous bone marrow transplantation in first remission had an overall survival of 86% and 47%, respectively, while the probability of leukemia-free survival in these groups was 87% vs. 40% at 4 yr. The CR rate and long-term results of this intensive treatment program compare favorably with other recent studies using intensive consolidation with allogeneic or autologous bone marrow transplantation or high dose cytarabine. 相似文献
13.
.OH生成液0.05ml.100g^-1经胶静脉注入心脏,可使麻醉大鼠的左心室收缩压力、左心室压力与心率乘积、左心室压力上升最大速率和左心室压力下降最大速率明显下降。 相似文献
14.
P. K. Lommatzsch I. H. Kirsch 《Documenta ophthalmologica. Advances in ophthalmology》1988,68(3-4):225-238
Therapeutic results are presented with follow-up examinations of at least 5 years (min. 5 years, max. 22 years) after 106Ru/106Rh plaque radiotherapy of posterior uveal melanomas. Out of 227 patients 146 (= 64.3%) could be treated successfully, 37 (= 16.3%) had to be enucleated and are alive, 44 (= 19.4%) died from metastases and 40 (17.6%) from other causes. 75.0% of all small melanomas (T1a) showed an excellent regression pattern to flat scars. Five years after treatment the survival rate was 83.7% (deaths from any causes) respectively 88.2% (deaths from metastases only) and 64.8% (deaths from any causes) respectively 79.7% (deaths from metastases only) ten years after irradiation. 106Ru/106Rh plaque radiotherapy can be recommended for small (Tla, b) and medium sized (T2) choroidal melanomas. 相似文献
15.
Japan Pancreatoduodenectomy Study Group Ryo Hosotani Masafumi Kogire Tadahiro Takada Hiroyuki Kato Takahiko Funabiki Masumasa Horisawa Takeshi Morimoto Takukazu Nagakawa Toshimichi Nakayama Itsuo Miyazaki Masayuki Imamura 《Journal of Hepato-Biliary-Pancreatic Surgery》1997,4(3):295-303
Endocrine tumor of the pancreas is potentially malignant. A multicenter analysis of these tumors was conducted to clarity
the present status of their surgical management and the subsequent long-term surgical results. The Japan pancreatoduodenectomy
(JPD) study group carried out the study; 368 patients were enrolled and variables related to tumor characteristics, surgery,
and survival were retrospectively analyzed. There were 222 patients with functioning tumor and 143 patients with nonfunctioning
tumor. Malignant tumor was found in 140 of 368 (38%) of the patients, and 63/140 (45%) of these patients had metastatic lesion;
the most common site of the metastasis was liver 34/136 (25%), followed by regional lymph nodes 26/136 (19%). Pancreatic resection
was performed in 91% of patients with nonfunctional tumor and in 83% of those with malignant tumor, and 73% of the pancreatic
resections were done with lymph node dissection. The overall 5-year actuarial survival rate was 76% in patients with malignant
tumor. The actuarial 5-year survival rate was 93% in the patients without metastasis and 83% in patients who received curative
resection. Multivariate analysis showed that the presence or absence of synchronous metastasis was the sole significant prognostic
factor. The results suggest that: (i) malignant endocrine tumor of the pancreas is a curable malignancy when pancreatic resection
with lymph node dissection is adopted and (ii) that synchronous metastasis is the dominant prognostic factor.
This study was carried out as a group project. The authors' institutions are as follows 相似文献
16.
17.
18.
Gérald Vanzetto Marc Janier Daniel Fagret Luc Cinotti Xavier André-Fouet Michel Comet Jacques Machecourt 《European journal of nuclear medicine and molecular imaging》1997,24(2):170-178
The best test presently available to ascertain residual viability within an infarct-related area involves the use of fluorine-18
fluorodeoxyglucose (FDG) to detect the persistence of some cellular metabolism. Rest reinjection of thallium-201 is a less
accurate alternative but is easy to perform. Iodinated fatty acids, which are used with standard gamma cameras, are proposed
as markers of cellular metabolism. This study was performed to assess the value of 16-iodo-3-methyl-hexadecanoic acid (MIHA)
as a marker of the residual cellular metabolism by comparison with FDG in patients with a recent myocardial infarction, and
to evaluate its contribution compared with the201Tl stress-redistribution-reinjection technique. Stress-redistribution-reinjection201T1 imaging, rest MIHA imaging and glucoseloaded FDG imaging were performed in 22 patients with recent myocardial infarction.
Out of the 628 myocardial segments obtained from the left ventricular analysis, 400 were hypoperfused (relative uptake <0.75
of maximum uptake on stress201T1 imaging), 177 of which were severely hypoperfused (relative uptake <0.50). Receiver operating characteristic (ROC) curves
for predicting metabolic myocardial viability with FDG were derived from the results in respect of (a)201T1 activity during exercise, redistribution and reinjection and (b) MIHA up-take, using the two FDG thresholds most commonly
considered to define metabolic viability (0.50 and 0.60). Analysis of the 400 hypoperfused segments demonstrated that201T1 reinjection was the most accurate test in predicting the presence of myocardial viability (area under the ROI curves=0.85
and 0.86 at the 0.50 and 0.60 FDG thresholds, respectively;P<0.05 vs other tests). The global predictive values of MIHA and201T1 reinjection were, respectively, 0.87 and 0.89 at the 0.50 FDG threshold (NS), and 0.82 and 0.87 at the 0.60 FDG threshold
(NS). When only the 177 severely hypoperfused segments were considered,201T1 reinjection remained the most accurate test (accuracy 0.84 at the 0.50 FDG threshold and 0.82 at the 0.60 FDG threshold),
while the accuracy of MIHA decreased significantly (0.78 at the 0.50 FDG threshold and 0.73 at the 0.60 FDG threshold,P<0.05 vs201T1 reinjection). In all circumstances, MIHA was less specific than201T1 reinjection for the detection of metabolic viability. In conclusion, in patients with recent myocardial infarction, MIHA
accurately detects the persistence of metabolic viability, but is not superior to201T1. 相似文献
19.
20.
人精子穿卵改良试验对不同生育状态男子生育力测定的价值 总被引:2,自引:0,他引:2
目的 本研究用一种经改良的人精子穿卵试验 (SPA)处理人精子 ,以探讨一种更简便、快速、经济 ,适合一般实验室要求的方法。方法 将精子体外获能液用磷酸氢二钠把pH值调理至 8.2± 0 .2 ;用普通隔水式恒温培养箱进行培养 ;对 75例不同生育状态男子生育力进行测定 (其中 2 5例有生育力男子 ;2 5例“原因不明”不育男子 ;及 2 5例输精管吻合术后 )。结果 3种不同生育状态男子的SPA值分别是 (4 7.12± 9.92 ) % ;(2 1.73± 9.91) % ,及 (2 8.0 4± 9.91) %。前两者在统计学上有显著差异 ,(P<0 .0 1) ;后两者在统计学上无明显差异 (P >0 .0 5 )。结果表明经用改良的精子获能液并在普通恒温培养箱培养后精子的活率和活力都有较大的提高 ,这有利于精子的长期获能及提高精子的穿透能力。结论 本研究提示改良后的人精子穿卵试验处理精子确实更简便、快速、经济 ,适合一般实验室要求 ,便于推广。 相似文献