全文获取类型
收费全文 | 23208篇 |
免费 | 1063篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 221篇 |
儿科学 | 488篇 |
妇产科学 | 234篇 |
基础医学 | 2947篇 |
口腔科学 | 409篇 |
临床医学 | 1507篇 |
内科学 | 6243篇 |
皮肤病学 | 551篇 |
神经病学 | 1791篇 |
特种医学 | 927篇 |
外科学 | 3724篇 |
综合类 | 64篇 |
一般理论 | 4篇 |
预防医学 | 600篇 |
眼科学 | 731篇 |
药学 | 1553篇 |
中国医学 | 36篇 |
肿瘤学 | 2398篇 |
出版年
2023年 | 137篇 |
2022年 | 319篇 |
2021年 | 550篇 |
2020年 | 272篇 |
2019年 | 345篇 |
2018年 | 452篇 |
2017年 | 351篇 |
2016年 | 461篇 |
2015年 | 518篇 |
2014年 | 644篇 |
2013年 | 783篇 |
2012年 | 1384篇 |
2011年 | 1446篇 |
2010年 | 825篇 |
2009年 | 749篇 |
2008年 | 1288篇 |
2007年 | 1437篇 |
2006年 | 1342篇 |
2005年 | 1495篇 |
2004年 | 1470篇 |
2003年 | 1291篇 |
2002年 | 1317篇 |
2001年 | 461篇 |
2000年 | 403篇 |
1999年 | 445篇 |
1998年 | 374篇 |
1997年 | 266篇 |
1996年 | 285篇 |
1995年 | 233篇 |
1994年 | 209篇 |
1993年 | 202篇 |
1992年 | 245篇 |
1991年 | 240篇 |
1990年 | 243篇 |
1989年 | 235篇 |
1988年 | 182篇 |
1987年 | 160篇 |
1986年 | 172篇 |
1985年 | 134篇 |
1984年 | 137篇 |
1983年 | 107篇 |
1982年 | 75篇 |
1981年 | 68篇 |
1980年 | 56篇 |
1979年 | 78篇 |
1978年 | 66篇 |
1977年 | 57篇 |
1974年 | 43篇 |
1971年 | 36篇 |
1970年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Acetylcholinesterase activity and pseudocholinesterase activity were examined in plasma and in striated muscles (whole heart and diaphragm muscles) of diabetic KK-CAy mice. Both activities of acetylcholinesterase in heart muscle and pseudocholinesterase in plasma were significantly increased in diabetic KK-CAy mice compared to pre-diabetic KK-CAy mice. Both acetylcholinesterase and pseudocholinesterase activities in skeletal muscle were not changed by the diabetic state. The increases in activity of plasma pseudocholinesterase was significantly correlated to the increase in blood glucose level in alloxan-, streptozotocin (STZ)-diabetic ddY mice and diabetic KK-CAy mice. The increase was not correlated to the body weight in non-diabetic female-KK-CAy mice. Furthermore, the activity of heart acetylcholinesterase was significantly correlated with the activity of plasma pseudocholinesterase (r = 0.79, P less than 0.01). The activities of acetylcholinesterases in heart muscles from STZ- and alloxan-diabetic ddY mice also tended to increase. The hypersensitivity of the pulse rate to a low dose (1 mg/kg) of acetylcholine was correlated to the activity of plasma pseudocholinesterase (r = -0.51, P less than 0.05). These results demonstrate that the activities of plasma pseudocholinesterase were increased by the diabetic state being associated with the increasing alteration of cardiac sensitivity to acetylcholine in the whole body. 相似文献
32.
Phenotype, donor-specific cytolytic activity, and helper activity to release cytokines of cells infiltrating within renal allografts of hosts rendered unresponsive by perioperative administration of donor lymphocytes via the portal vein (p.v.) were investigated in order to analyze the mechanism of prolongation of allograft survival. Graft-infiltrating cells (GIC) were obtained from Lewis (LEW, RT-1l) hosts inoculated perioperatively with 1 x 10(8) donor Brown-Norway (BN, RT-1n) lymphocytes p.v., a group that displays prolonged renal allograft survival (MST: 22.2 +/- 5.3 days, n = 10) compared with an uninoculated control group (MST: 7.8 +/- 0.6 days, n = 10, P less than 0.01). The percentages of cytotoxic/suppressor T cells (OX-8+) and Ia-positive cells (OX-6+) in GIC (23.1 +/- 4.4% and 9.0 +/- 2.0%, respectively) and in spleen cells (7.5 +/- 2.6% and 8.5 +/- 1.1%, respectively) from p.v.-inoculated LEW hosts on day 6 postgrafting were significantly lower than those of uninoculated control recipients (GIC: OX-8; 39.4 +/- 8.2%, OX-6; 23.0 +/- 1.9%. SP cell: OX-8; 21.6 +/- 9.9%, OX-6; 12.7 +/- 0.4%, P less than 0.05). Cytolytic activity of GIC from tolerant hosts on day 6 postgrafting toward donor blastoid lymphocytes was significantly decreased (19.0 +/- 1.2% at E/T = 50), compared with that from control allografts during ongoing rejection (51.5 +/- 5.3%, P less than 0.01). The amounts of in vitro cytokine production of GIC from tolerant hosts after mitogen stimulation were remarkably decreased (IL-2: 8.7 +/- 1.4 U/ml, IL-3: 15.4 +/- 0.6 U/ml, and BSF-2: 24.6 +/- 3.5 U/ml) than those of uninoculated control hosts during ongoing rejection (IL-2: 19.6 +/- 2.9 U/ml, IL-3: 22.2 +/- 2.7 U/ml, and BSF-2: 67.5 +/- 13.2 U/ml, P less than 0.05). These results demonstrated that activation of both Tc cells and Th cells was inhibited in the spleen and in situ in renal allografts following administration of donor lymphocytes through the portal vein. 相似文献
33.
Shoji Sunada Masahiko Miyata Yasuhiro Tanaka Kenzo Okumura Makoto Nakamuro Toru Kitagawa Ryota Shirakura Yasunaru Kawashima 《Surgery today》1992,22(1):74-77
An aggressive pancreatectomy was performed on a 53 year old Japanese man with advanced cancer of the pancreas. The tumor originated from the body of the pancreas and invaded the stomach, duodenum, left kidney, transverse colon and common hepatic artery. An unexpected cancer was also found in the head of the pancreas during the operation. Therefore, total pancreatectomy, total gastrectomy, left adrenonephrectomy, resection of the left transverse colon and dissection of the regional lymph nodes were performed. Resection of the common hepatic artery was also performed, followed by an end-to-end anastomosis between the common hepatic artery and celiac trunk. The postoperative course was uneventful and the patient was doing well until nine months after the operation when multiple metastatic lesions were noted in the liver. He died 391 days after the operation from hepatic failure. 相似文献
34.
We have developed an implant heating system (IHS) for interstitial hyperthermia of brain tumors. IHS consists of three compartments: ferromagnetic implant with low Curie point, induction coil and generator to produce high frequency magnetic field. The device works as follows: It is heated up to a Curie temperature (Tc) by Eddy current under the magnetic field. Heat generated in the implant is conducted to the tumor tissue into which it has been implanted. To evaluate the effect of this hyperthermia, a brain tumor model was produced by innoculation of VX2 tumor cells and treated either by hyperthermia with IHS alone, chemotherapy with ACNU alone, or with a combination of both. The longest survival was obtained by the combined treatment, and significant prolongation of survival was found in the single treatment groups. In the Phase I clinical trial, one or several implants (1.8 mm X 15 mm, Tc = 68 degrees C) made of Fe-Pt alloy were placed in the tumor by CT guided stereotactic procedure, or manually during craniotomy. Hyperthermia of above 42 degrees C for 30 to 60 minutes twice a week was brought about in ten cases of malignant brain tumor. CT evaluation was made in nine cases treated for more than ten times in this way. Five out of the nine cases responded to this hyperthermia with irradiation. In conclusion, a safe, repeated and longterm treatment was possible without significant side effects. The hyperthermia with IHS may also be applicable to benign intracranial tumors and neoplasms in other part of body as well. 相似文献
35.
Yoshihiro Wakayama Masahiko Inoue Makoto Murahashi Seiji Shibuya Takahiro Jimi Hiroko Kojima Hiroaki Oniki 《Annals of neurology》1996,39(2):217-223
The ultrastructural localization of adhalin and its relations to dystrophin, β-dystroglycan, and β-spectrin were studied in normal murine skeletal myofibers. The C-terminal peptides of adhalin and β-dystroglycan were synthesized based on their cDNAs, and the affinity-purified antibodies against these peptides were produced. Single-immunolabeling electron microscopy showed that the adhalin was located just inside the muscle plasma membrane or inside the myofiber a short distance from the plasma membrane. The adhalin signal was also noted at the sarcoplasmic side of plasmalemmd invaginations or at vesicular structures in subsarcolemmal areas. Double-immunogold-labeling electron microscopy disclosed a similar localization of dystrophin, β-dystroglycan, and β-spectrin. The close association of adhalin with dystrophin or β-dystroglycan was demonstrated by formation of doublets by signals of antibodies of adhalin with those of dystrophin or β-dystroglycan and was confirmed by statistical analyses. This study demonstrated that the location of adhalin is close to that of dystrophin and β-dystroglycan at the muscle plasma membrane. 相似文献
36.
37.
38.
39.
40.
Bacterial components regulate the expression of Toll-like receptor 4 on human mast cells 总被引:3,自引:0,他引:3
Y. Kubo N. Fukuishi M. Yoshioka Y. Kawasoe S. Iriguchi N. Imajo Y. Yasui N. Matsui M. Akagi 《Inflammation research》2007,56(2):70-75
Objectives and design: The aim of this study was to investigate whether the exposure of mast cells (MCs) to bacterial components affects the expression
of Toll-like receptor (TLR) 4, and to elucidate the behavior of MCs during the early response to infection.
Materials: Two human MC lines, HMC-1 and LAD2, were employed. Messenger RNA expression was observed by RT and real-time PCR. TLR4 expression
was determined by Western blotting. TNF-α secretion was analyzed with ELISA. The degranulation ratio was measured with betahexosaminidase
assay.
Results: Although bacterial components increased TLR4 mRNA, only lipopolysaccharide (LPS) augmented the TLR4 protein expression. LAD2
pre-treated with LPS for 8 h resulted in 2-fold increased TNF-α secretion on LPS restimulation.
Conclusion: These results suggest that the exposure of MCs to LPS may reinforce the innate immune system due to up-regulation of MC TLR4,
followed by increased TNF-α release.
Received 20 April 2006; returned for revision 14 July 2006; accepted by G. Wallace 11 August 2006 相似文献