全文获取类型
收费全文 | 8511篇 |
免费 | 371篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 168篇 |
妇产科学 | 148篇 |
基础医学 | 1003篇 |
口腔科学 | 206篇 |
临床医学 | 518篇 |
内科学 | 2335篇 |
皮肤病学 | 215篇 |
神经病学 | 547篇 |
特种医学 | 351篇 |
外科学 | 1052篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 301篇 |
眼科学 | 147篇 |
药学 | 788篇 |
中国医学 | 11篇 |
肿瘤学 | 1059篇 |
出版年
2023年 | 77篇 |
2022年 | 150篇 |
2021年 | 218篇 |
2020年 | 114篇 |
2019年 | 126篇 |
2018年 | 169篇 |
2017年 | 145篇 |
2016年 | 145篇 |
2015年 | 151篇 |
2014年 | 180篇 |
2013年 | 254篇 |
2012年 | 461篇 |
2011年 | 468篇 |
2010年 | 267篇 |
2009年 | 215篇 |
2008年 | 397篇 |
2007年 | 432篇 |
2006年 | 420篇 |
2005年 | 463篇 |
2004年 | 394篇 |
2003年 | 365篇 |
2002年 | 434篇 |
2001年 | 218篇 |
2000年 | 256篇 |
1999年 | 247篇 |
1998年 | 126篇 |
1997年 | 112篇 |
1996年 | 81篇 |
1995年 | 75篇 |
1994年 | 56篇 |
1993年 | 61篇 |
1992年 | 160篇 |
1991年 | 141篇 |
1990年 | 148篇 |
1989年 | 146篇 |
1988年 | 138篇 |
1987年 | 126篇 |
1986年 | 120篇 |
1985年 | 123篇 |
1984年 | 84篇 |
1983年 | 55篇 |
1982年 | 32篇 |
1981年 | 29篇 |
1980年 | 28篇 |
1979年 | 47篇 |
1978年 | 26篇 |
1975年 | 23篇 |
1974年 | 20篇 |
1972年 | 20篇 |
1969年 | 34篇 |
排序方式: 共有8950条查询结果,搜索用时 15 毫秒
101.
Naoki Ishiguro Takashi Nozawa Akiko Tsujihata Asami Saito Wataru Kishimoto Kazutoshi Yokoyama Takafumi Yotsumoto Kenji Sakai Takashi Igarashi Ikumi Tamai 《Drug metabolism and disposition》2004,32(5):519-524
We investigated influx and efflux transporters involved in blood-brain barrier transport of the nonsedative H1-antagonist epinastine. The basal-to-apical transport of [14C]epinastine was markedly higher than that in the opposite direction in LLC-GA5-COL150 cells stably transfected with human multidrug resistance (MDR)1 gene. The brain-to-plasma concentration ratio of [14C]epinastine in mdr1a/b(-/-) mice was 3.2 times higher than that in wild-type mice. The uptake of both [3H]mepyramine and [14C]epinastine into immortalized rat brain capillary endothelial cells (RBEC)1 showed temperature and concentration dependence. The kinetic parameters, K(m), V(max), and uptake clearance (V(max)/K(m)), of the initial uptake of [3H]mepyramine and [14C]epinastine by RBEC1 were 150 microM, 41.8 nmol/min/mg protein, and 279 microl/min/mg protein for mepyramine and 10.0 mM, 339 nmol/min/mg protein, and 33.9 microl/min/mg protein for epinastine, respectively. The uptake of [3H]mepyramine and [14C]epinastine by RBEC1 was inhibited by organic cations such as quinidine, amantadine, and verapamil, but not by other organic cations, tetraethyl ammonium, guanidine, and carnitine. Organic anions such as benzoic acid, estrone-3-sulfate, taurocholate, and neutral digoxin were not inhibitory. Furthermore, some cationic H1 antagonists (chlorpheniramine, cyproheptadine, ketotifen, and desloratadine) inhibited the [3H]mepyramine and [14C]epinastine uptake into RBEC1. In conclusion, the present study demonstrated that the combination of efficient efflux transport by P-glycoprotein and poor uptake by the influx transporter, which is identical with that responsible for the uptake of mepyramine, account for the low brain distribution of epinastine. 相似文献
102.
103.
Yamazaki T Sato Y Hanai M Mochimaru J Tsujino I Sawada U Horie T 《Cancer letters》2000,149(1-2):153-161
The non-ionic detergent Tween 80, which is used as a solvent for lipophilic drugs such as VP-16 and Taxotere, was found to reverse VP-16 resistance of the P-glycoprotein-associated multidrug resistance phenotype via increasing VP-16 influx. In adriamycin-resistant human chronic myelogenous leukemia K562 cells (K562/ADM), which overexpress mdr1 mRNA, the accumulation of VP-16 was only about 10% that in wild-type K562 cells. Tween 80 enhanced VP-16 accumulation in K562/ADM cells but did not influence VP-16 accumulation in parental K562 cells. VP-16 efflux was rapid and similar in both sensitive and resistant cell lines and was not blocked by Tween 80 or verapamil. Under glucose-free conditions, VP-16 accumulation in K562/ADM cells was only half of that in K562 cells. Tween 80 increased VP-16 accumulation in K562/ADM cells in glucose-free medium. In growth inhibition assay, Tween 80 reversed K562/ADM sensitivity to VP-16 without cell damage. Taken together, Tween 80 reverses VP-16 sensitivity in multidrug-resistant K562 cells by increasing influx, which is considered to be the primary mechanism of VP-16 resistance in K562/ADM cells. 相似文献
104.
Enhancement of radiation effects by acyclovir 总被引:1,自引:0,他引:1
M Sougawa K Akagi T Murata S Kawasaki S Sawada G Yoshii Y Tanaka 《International journal of radiation oncology, biology, physics》1986,12(8):1537-1540
Acyclovir (ACV), a new antiviral drug, was used to investigate its effect of radiosensitivity in tumors in vivo. In in vivo experiments with Sarcoma-180 transplanted into the ICR mouse and FM3A transplanted into the C3H mouse, ACV enhanced the radiosensitivity of both tumors. In S-180, radiation effects were enhanced by treatment with 100 mg/kg of ACV from 30 min before to 60 min after irradiation. In S-180 treated by 400 mg/kg of ACV, the enhancement ratio was approximately 2.0, as evaluated by the growth delay method. In the FM3A tumor treated by 20 mg/kg of ACV, the enhancement ratio was approximately 1.3, as evaluated by tumor cure (TCD50 assay). ACV is already clinically used as an antiviral drug. Its ability to radiosensitize tumors could therefore have clinical potential when combined with radiotherapy. 相似文献
105.
Y. Harima K. Nagata K. Harima V. V. Ostapenko Y. Tanaka S. Sawada 《International journal of hyperthermia》2013,29(5):338-343
To clarify the role of thermoradiotherapy for FIGO Stage IIIB cervical carcinomas, both the clinical response and survival of patients treated with radio- or thermoradiotherapy were investigated. Forty patients with Stage IIIB uterine cervix carcinoma were treated with external beam irradiation to the pelvis, combined with iridium 192 high-dose-rate intracavitary brachytherapy. All patients were divided randomly into the following two groups: the radiotherapy (RT) group of 20 patients, who underwent radiotherapy alone; and the thermoradiotherapy (TRT) group of 20 patients, who underwent three sessions of hyper-thermia in addition to radiotherapy. The primary endpoint of this study was local complete response and survival. A complete response was achieved in 50% (10 of 20) in the RT group versus 80% (16 of 20) in the TRT group (p = 0.048). The 3-year overall survival and disease-free survival of the patients who were treated with TRT (58.2 and 63.6%) were better than those of the patients treated with RT (48.1 and 45%), but these differences were not significant. The 3-year local relapse-free survival of the patients who were treated with TRT (79.7%) was significantly better than that of the patients treated with RT (48.5%) (p = 0.048). TRT, as delivered in this trial, was well tolerated and did not significantly add to either the relevant clinical acute or long-term toxicity over radiation alone. TRT resulted in a better treatment response and 3-year local relapse-free survival rate than RT for patients with FIGO Stage IIIB cervical carcinoma. 相似文献
106.
Mutation of the PTEN gene in advanced cervical cancer correlated with tumor progression and poor outcome after radiotherapy 总被引:11,自引:0,他引:11
Harima Y Sawada S Nagata K Sougawa M Ostapenko V Ohnishi T 《International journal of oncology》2001,18(3):493-497
Improvement in management of advanced cervical cancer after radiotherapy requires a better understanding of its biological behavior. PTEN/MMAC/TEP(PTEN), a candidate tumor suppressor gene located at chromosome 10q23.3, was recently identified and found to be frequently mutated in several different types of human tumors. In contrast, rare mutations of the PTEN gene have been reported in cervical cancer. The aim of this study was to determine whether mutation of PTEN leads to increased genomic alteration in advanced cervical carcinoma, and to identify the correlation between mutation of PTEN and patient outcome after radiotherapy. We examined 50 primary advanced cervical carcinomas (37 patients of Stage IIIB, 13 patients of Stage IVA) treated with definitive radiotherapy using a PCR-based assay followed by SSCP and direct sequencing. The PTEN gene was mutated in 8 of the 50 (16%) patients (2 of Stage III, and 6 of Stage IV). There was a significant difference in Stage III versus IV between the wild-type PTEN patients and mutant PTEN patients (P=0.002). The tumor size was 6+/-2.1 cm in the wild-type PTEN tumors versus 8.5+/-2 cm in the mutant PTEN tumors (P=0.009). In addition, there was a significant difference in survival between the wild-type PTEN patients and mutant PTEN patients (P=0.009). The results of this study suggest that the PTEN gene mutation rate increases with tumor progression, and that the PTEN gene may play a role in both progression of cervical carcinoma and treatment outcome. 相似文献
107.
Efficacy of Trabectedin in Patients with Advanced Translocation‐Related Sarcomas: Pooled Analysis of Two Phase II Studies 下载免费PDF全文
108.
Toru Aoyama Takaki Yoshikawa Takafumi Watanabe Tsutomu Hayashi Takashi Ogata Haruhiko Cho Akira Tsuburaya 《Gastric cancer》2012,15(1):76-82
Background
The safety and feasibility of administering S-1 adjuvant chemotherapy for gastric cancer has not been fully evaluated in elderly patients. 相似文献109.
Effects of crude drugs on experimental hypercholesterolemia. I. Tea and its active principles 总被引:4,自引:0,他引:4
H Matsuda T Chisaka Y Kubomura J Yamahara T Sawada H Fujimura H Kimura 《Journal of ethnopharmacology》1986,17(3):213-224
The effect of methanol extractives from tea leaves on hypercholesterolemia was examined in animal models. It was found that orally administered (-)-epicatechin gallate and (-)-epigallocatechin gallate from tea leaves lowered the serum cholesterol level in mice fed a high fat emulsion. Quantitation of tissue cholesterol and examination of liver tissues in mice fed a high cholesterol diet revealed that these constituents also significantly lowered the amount of cholesterol crystallization. These results support the reputed effectiveness of tea use in hypercholesterolemia. 相似文献
110.
Takafumi Mizuno Takao Hoshino Kentaro Ishizuka Sono Toi Ayako Nishimura Shuntaro Takahashi Sho Wako Kazuo Kitagawa 《Journal of atherosclerosis and thrombosis》2022,29(9):1393
Aims: We aimed to determine the characteristics and vascular outcomes of stroke in renal transplant (RT) recipients and compare them with those in patients on hemodialysis (HD) and those with no renal replacement therapy (RRT). Methods: In this prospective observational study, 717 patients (mean age, 70.8 years; male, 60.5%) with acute ischemic stroke within one week of onset were consecutively enrolled and followed for one year. The patients were classified into three groups: (1) living donor RT recipients (n=27); (2) patients on maintenance HD before the index stroke (n=39); and (3) those with no history of RRT (n=651). The primary outcome was a composite of major adverse cardiovascular events (MACE). Results: Diabetic nephropathy was the most common reason for RRT in both RT and HD patients. RT patients were more likely to have embolic stroke of undetermined source (33.3%) than others, whereas HD patients more often had cardioembolism (51.3%). No difference was observed in the MACE risk between the patients in RT and non-RRT groups (annual rate, 11.3% vs. 13.1%; log-rankP=0.82; hazard ratio [95% confidence interval], 0.92 [0.29-2.98]). In contrast, HD patients had a greater risk of MACE than those with no RRT (annual rate, 28.2% vs. 13.1%; log-rankP=0.019; hazard ratio [95% confidence interval], 2.24 [1.16-4.3]). Conclusions: The underlying etiologies of stroke differed in RT and HD patients. The one-year risk of MACE for stroke patients who had received an RT was lower than that for patients undergoing HD and comparable with that of patients with no RRT. 相似文献