全文获取类型
收费全文 | 19752篇 |
免费 | 1308篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 516篇 |
妇产科学 | 399篇 |
基础医学 | 2292篇 |
口腔科学 | 396篇 |
临床医学 | 1598篇 |
内科学 | 4135篇 |
皮肤病学 | 237篇 |
神经病学 | 1089篇 |
特种医学 | 574篇 |
外科学 | 3562篇 |
综合类 | 664篇 |
一般理论 | 19篇 |
预防医学 | 1507篇 |
眼科学 | 549篇 |
药学 | 1941篇 |
中国医学 | 221篇 |
肿瘤学 | 1278篇 |
出版年
2023年 | 161篇 |
2022年 | 439篇 |
2021年 | 713篇 |
2020年 | 465篇 |
2019年 | 575篇 |
2018年 | 686篇 |
2017年 | 486篇 |
2016年 | 402篇 |
2015年 | 565篇 |
2014年 | 748篇 |
2013年 | 930篇 |
2012年 | 1383篇 |
2011年 | 1392篇 |
2010年 | 787篇 |
2009年 | 604篇 |
2008年 | 1074篇 |
2007年 | 1090篇 |
2006年 | 1001篇 |
2005年 | 920篇 |
2004年 | 832篇 |
2003年 | 753篇 |
2002年 | 632篇 |
2001年 | 549篇 |
2000年 | 496篇 |
1999年 | 400篇 |
1998年 | 145篇 |
1997年 | 113篇 |
1996年 | 113篇 |
1995年 | 118篇 |
1994年 | 67篇 |
1993年 | 76篇 |
1992年 | 205篇 |
1991年 | 193篇 |
1990年 | 170篇 |
1989年 | 174篇 |
1988年 | 136篇 |
1987年 | 155篇 |
1986年 | 127篇 |
1985年 | 140篇 |
1984年 | 112篇 |
1983年 | 86篇 |
1982年 | 59篇 |
1981年 | 61篇 |
1979年 | 102篇 |
1978年 | 65篇 |
1977年 | 67篇 |
1975年 | 60篇 |
1974年 | 52篇 |
1973年 | 56篇 |
1972年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 828 毫秒
71.
Species-dependent differences in the properties of particulate cyclic nucleotide phosphodiesterase from rat and rabbit ventricular myocardium 总被引:3,自引:0,他引:3
M Shahid M Wilson C D Nicholson R J Marshall 《The Journal of pharmacy and pharmacology》1990,42(4):283-284
The ability of cyclic nucleotide phosphodiesterases (PDEs) to hydrolyse cyclic (c)AMP in rat and rabbit ventricular myocardium has been compared. The PDE activity of rabbit, but not rat, cardiac homogenate and supernatant fraction was potentiated by Ca2+/calmodulin and attenuated by cGMP. Both rabbit and rat ventricular myocardium were shown to have a membrane bound PDE. However, rabbit membrane-bound PDE was inhibited by cGMP and low concentrations of milrinone (IC50 2.7 microM). In contrast, rat membrane-bound PDE was not inhibited by either cGMP or low concentrations of milrinone (IC50 19 microM), but it was potently inhibited by rolipram (IC50 2.2 microM). Thus, in rabbit the particulate PDE is milrinone sensitive (PDE III) whilst in rat it is the rolipram sensitive (PDE IV) isoenzyme. There are clearly species differences in the intracellular localization and relative activities of PDE isoenzymes in cardiac tissue. This may explain the species differences already found in the activity of selective PDE isoenzyme inhibitors as inotropic agents. 相似文献
72.
73.
74.
Shahid Hussain Darren E Dreyfus Richard J Marcus Robert W W Biederman Rita L McGill 《Nephrology, dialysis, transplantation》2003,18(11):2364-2368
BACKGROUND: Spironolactone is useful in heart failure, but is not given to dialysis patients for fear of hyperkalaemia. This study evaluated the safety of spironolactone administration in haemodialysis patients. METHODS: Fifteen haemodialysis outpatients with mean serum potassium <5.6 mEq/l over the preceding 4 months were treated with spironolactone 25 mg daily for 28 days. Serum potassium was measured before every haemodialysis during the study. Aldosterone and renin were measured at the beginning and end of the study. Patients were monitored for side effects. Data were examined with a paired t-test, with patients serving as their own controls and P < 0.05 considered significant. A sample size of 14 was required to achieve a power of 0.8 and a P = 0.05 to detect a potassium difference of 0.5 +/- 0.6 mEq/l. All patients were analysed as intention-to-treat. RESULTS: The mean potassium level was 4.6 +/- 0.6 mEq/l at baseline and 4.9 +/- 0.9 mEq/l at study completion (P = 0.14). Thirteen patients completed the trial with no potassium levels >6.0 mEq/l. Four patients had potassium levels between 5.5 and 6.0 mEq/l. One patient was withdrawn at day 20 after developing hyperkalaemia (7.6 mEq/l). Another patient was withdrawn at day 25 after missing a dialysis treatment. There were no differences in either baseline or 28 day aldosterone or renin levels (16.8 +/- 28.8 vs 11.7 +/- 6.1 ng/dl and 3.5 +/- 3.9 vs 3.5 +/- 3.5 ng/ml/h, respectively). Infrequent side effects included dry mouth, nosebleed, pruritis, gynecomastia and diarrhoea. No significant leukopenia or anaemia was noted. CONCLUSIONS: Spironolactone may be considered as a treatment option for selected chronic haemodialysis patients with heart disease. 相似文献
75.
Sustained Release Coprecipitates and Matrix Tablets of Ibuprofen with Polyacrylic Resin Ⅱ:Formulation and in vitro Evaluation
下载免费PDF全文
![点击此处可从《中国药科大学学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
将药物及高分子材料溶于乙醇后边搅拌边加入非溶剂制成布洛芬-聚丙烯酸树脂Ⅱ共沉淀物。通过A、B两种方法并以不同的药物-聚丙烯酸树脂Ⅱ比例制成了共沉淀物,再以这些共沉淀物直接压片制成骨架片。通过差热分析(DSC)、扫描电镜(DSC)及红外光谱(IR)研究了共沉淀物的性质。研究主要集中在处方中高分子材料所占的比例,溶出介质的pH及制备共沉淀物的方法对布洛芬从骨架中释放的影响。体外溶出实验分别在不同的pH条件下进行。处方研究表明随着聚丙烯酸树脂Ⅱ用量的增加,药物的释放过程显著延长。另外,增加溶出介质的pH会显著增加药物的累积释放百分数。此外实验还表明以方法B制成的共沉淀物的骨架片中药物的累积释放百分数要高于A法制成的骨架片,然而方法A中制得的骨架片中药物的释放却更接近于线性释放。 相似文献
76.
77.
Comorbidities in head and neck cancer: agreement between self-report and chart review. 总被引:1,自引:1,他引:0
Shraddha S Mukerji Sonia A Duffy Karen E Fowler Mumtaz Khan David L Ronis Jeffrey E Terrell 《Otolaryngology--head and neck surgery》2007,136(4):536-542
OBJECTIVES: To determine the accuracy of self-reported comorbidities compared with medical record review and the clinical and sociodemographic characteristics associated with accuracy of self-reported comorbidities. STUDY DESIGN: We conducted a prospective study of 458 newly diagnosed head and neck cancer patients using self-administered questionnaire and medical chart review data. Overall and itemwise consistency between self-report and chart review was evaluated. Social, clinical, and demographic characteristics of consistent versus inconsistent responders were analyzed. RESULTS: Seventy-four percent of patients had at least one comorbidity. There was good overall consistency between self-report and chart review (kappa = 0.50). Compared with consistent responders, inconsistent responders were found to be older (P < 0.05), have lower sleep (P < 0.05) and physical activity scores (P < 0.05), be more depressed (P < 0.05), and have more severe comorbidities (P < 0.05). CONCLUSIONS AND SIGNIFICANCE: Self-report may be considered as an alternative to chart review for comorbidity assessment in head and neck cancer patients. Younger patients, those with good general health, fewer depressive symptoms, and mild comorbidities, are more likely to give responses consistent with chart review. 相似文献
78.
Seema Khan Smita Singhal Tarun Mathur Dilip J Upadhyay Ashok Rattan 《Nippon Ishinkin Gakkai Zasshi》2007,48(3):109-113
Disulfiram, an alcohol antagonistic drug has been on the market since 1949 with 80% bioavailability and an established safety profile. Recently it has been reported as a P-glycoprotein efflux pump modulator. Herein we report its antifungal potential. The MIC50 and MIC90 of disulfiram for yeast isolates is 4 and 8 microg/ml, respectively, and the MIC range is 1-16 micro g/ml for both fluconazole sensitive and resistant strains. Interestingly, disulfiram also showed fungicidal activity on Aspergillus spp. with MIC50 and MIC90 of 2 and 8 microg/ml, respectively. 相似文献
79.
Tension development in response to direct and indirect electrical stimulation was studied in an isolated phrenic nerve hemidiaphragm preparation of the mouse. β-Endorphin (β-EP) caused an increase in the preparation of the mouse. β-Endorphin (β-EP) caused an increase in the response to low frequency stimulation of the nerve. Upon direct stimulation of the muscle the peptide had no effect. The actions of β-EP were abolished in the presence of the opioid antagonist naloxone and mimicked by β opioid agonists. Upon high frequency stimulation of the nerve, β-EP caused an increase in the initial, maximum, and mean tension. It also prevented the fall in the final tension seen in the control preparations with repeated periods of stimulation. The findings are consistent with β-EP having a role to improve neuromuscular function and deley fatigue, and indicate the possible therapeutic potential of opioid substances in conditions where muscle weakness is present. © John Wiley & Sons, Inc. 相似文献
80.