全文获取类型
收费全文 | 13469篇 |
免费 | 1725篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 191篇 |
儿科学 | 417篇 |
妇产科学 | 276篇 |
基础医学 | 1865篇 |
口腔科学 | 256篇 |
临床医学 | 1659篇 |
内科学 | 2716篇 |
皮肤病学 | 220篇 |
神经病学 | 1344篇 |
特种医学 | 399篇 |
外国民族医学 | 1篇 |
外科学 | 1822篇 |
综合类 | 309篇 |
一般理论 | 9篇 |
预防医学 | 1481篇 |
眼科学 | 222篇 |
药学 | 1288篇 |
中国医学 | 21篇 |
肿瘤学 | 719篇 |
出版年
2021年 | 227篇 |
2020年 | 141篇 |
2019年 | 222篇 |
2018年 | 285篇 |
2017年 | 173篇 |
2016年 | 206篇 |
2015年 | 210篇 |
2014年 | 305篇 |
2013年 | 381篇 |
2012年 | 617篇 |
2011年 | 633篇 |
2010年 | 339篇 |
2009年 | 343篇 |
2008年 | 605篇 |
2007年 | 606篇 |
2006年 | 577篇 |
2005年 | 561篇 |
2004年 | 533篇 |
2003年 | 501篇 |
2002年 | 508篇 |
2001年 | 492篇 |
2000年 | 436篇 |
1999年 | 394篇 |
1998年 | 164篇 |
1997年 | 167篇 |
1996年 | 154篇 |
1995年 | 157篇 |
1994年 | 139篇 |
1993年 | 133篇 |
1992年 | 393篇 |
1991年 | 331篇 |
1990年 | 297篇 |
1989年 | 287篇 |
1988年 | 323篇 |
1987年 | 282篇 |
1986年 | 254篇 |
1985年 | 209篇 |
1984年 | 241篇 |
1983年 | 185篇 |
1982年 | 134篇 |
1981年 | 106篇 |
1980年 | 106篇 |
1979年 | 188篇 |
1978年 | 119篇 |
1976年 | 125篇 |
1975年 | 122篇 |
1974年 | 119篇 |
1973年 | 109篇 |
1972年 | 113篇 |
1970年 | 108篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
R Dixon AM Hughes K Nairn M Sellers JV Kemp RA Yates 《Cephalalgia : an international journal of headache》1998,18(7):468-475
Zolmitriptan (ZomigTM ) is a 5HT1B/1D agonist which has the ability to cross the intact blood-brain barrier to access central as well as peripheral receptors. Because of the potential for central nervous system side effects, this randomized, double-blind, placebo-controlled, 6-period crossover study evaluated the effects of 2.5 and 5 mg doses of zolmitriptan on psychomotor performance and investigated any pharmacodynamic or pharmacokinetic interaction with diazepam. Twelve healthy volunteers received the following "treatments" as single doses: zolmitriptan 2.5 mg, zolmitriptan 5 mg, diazepam 10 mg, zolmitriptan 2.5 mg+diazepam 10 mg, zolmitriptan 5 mg+diazepam 10 mg and placebo. Pre-dose and at 1, 4, 8, and 24 h post-dose, the following validated battery of psychomotor tests was performed: Bond-Lader visual analogue scales (calmness, contentedness, and alertness factors), critical flicker fusion test, choice reaction time (recognition, motor, and total reaction times), finger-tapping test, number cancellation test and digit symbol substitution test. Plasma concentrations of zolmitriptan, its active metabolite, and diazepam and its active metabolites were measured at the same timepoints. Zolmitriptan 2.5 and 5 mg had no effect on psychomotor function when given alone. In contrast, diazepam 10 mg had profound effects, consistent with its sedative properties, but there was no synergism on concomitant administration of either dose of zolmitriptan. Plasma concentrations of zolmitriptan, diazepam, and their respective active metabolites were similar when the two drugs were given alone or in combination. 相似文献
104.
105.
C. J. English W. M. Maclaren C. Court-Brown S. P. F. Hughes R. W. Porter W. A. Wallace R. J. Graves A. J. Pethick C. A. Soutar 《American journal of industrial medicine》1995,27(1):75-90
To make a preliminary assessment of whether upper limb soft tissue disorders might be associated with activities at work, we have conducted a case-control study of subjects attending orthopedic clinics in three cities. All subjects between the ages of 16 and 65 years, in whom defined soft tissue conditions of the upper limb were diagnosed by the participating orthopedic surgeons, were invited to take part. Controls were subjects attending the same clinics within the same age range whose clinical diagnosis did not include disease of the upper limb, cervical or thoracic spine. Information concerning repetitive movements of the upper limbs at work was elicited by questionnaire. Five hundred eighty cases and 996 controls were studied, representing 96% and 93%, respectively, of those invited to participate. The diagnoses of the cases included soft tissue conditions affecting the shoulder, elbow, forearm, wrist, thumb, hand, and fingers. The diagnoses of the controls included traumatic, degenerative, and inflammatory conditions, mostly of the legs and lower back. Women predominated among the cases (70%) and men among the controls (56%). Of 221 female cases with injury to the wrist and forearm, 32 were cleaner/domestics (14.5%) compared to 35 of 439 controls (8%), a difference statistically significant at the 2 1/2% level. Other jobs significantly overrepresented (5% level) among female cases with injuries at various anatomical sites included hairdressers, secretary/temps, assembly line workers, and machine operators (type unspecified). Among male cases, electricians were significantly overrepresented (5% level). Jobs for which there was a suggestion (p < 0.1) of overrepresentation among cases included butchers and teacher/ lecturers (both males only) and the combined job groups (chosen a priori for analysis) of keyboard operators, machine operators, and music teachers (all three jobs, females only). 相似文献
106.
107.
108.
Brian M. Hughes 《Journal of Applied Biobehavioral Research》2004,9(1):23-44
Stress arising from academic performance affects many college students. Moreover, students account for the majority of participants in cardiovascular reactivity research. The current research comprised three brief experiments investigating different aspects of student samples. In Experiment 1, students' (n = 30) academic fear of failure was found to be negatively correlated with systolic blood pressure reactivity. In Experiment 2, students' (n= 13) blood pressure was found to be significantly elevated 2 weeks before college examinations, compared with postexamination levels. Finally, in Experiment 3, students' (n = 19) examination performance was positively correlated with preexamination cardiovascular reactivity. These findings suggest specific college‐related factors that influence the cardiovascular stress response in students and, therefore, should aid the interpretation of much research conducted in cardiovascular health psychology. 相似文献
109.
This paper reports the psychometric testing of the Worthing Chemotherapy Questionnaire(WCQ). The WCQ is a patient self-report instrument to document side-effects of chemotherapy. Literature review of relevant studies shows that psychometric testing of similar instruments is rarely rigorous. Content validity for the WCQ was established in five ways: literature review, Delphi review among oncology staff, pre-pilot unstructured interviews, pilot study and amendment of the instrument and items for spontaneous reporting of problems on the questionnaire. A three-stage approach to construct validity was used. The hypothesis adopted was that as certain cytotoxic agents cause stomatitis, incidence and severity of stomatitis will decrease following cessation of treatment. Stage 1: factor analysis confirmed the presence of a sole factor, with an eigenvalue of 5.3, for mouth problems which explained 65.5% of the variance. Stage 2: the hypothesis was confirmed using research findings. Stage 3: the Wilcoxon test showed highly significant results for during and post chemotherapy stomatitis scores. Reliability of the questionnaire was assessed using the test-retest method. Weighted Kappa was chosen as the test statistic. A median value of w K=0.87 was obtained. The results indicate that the WCQ is a reliable and valid instrument. 相似文献
110.
Dipyridamole alone or combined with low-dose acetylsalicylic acid inhibits platelet aggregation in human whole blood ex vivo. 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《British journal of clinical pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J R Hughes S G Bowes A L Leeman C J O''''Neill A A Deshmukh P W Nicholson S M Dobbs R J Dobbs 《British journal of clinical pharmacology》1990,29(2):179-186
1. In a randomized, double-blind trial we compared the inhibition of the platelet-vessel wall interactions in whole blood ex vivo. There were four groups of 24 healthy volunteers each of whom were treated orally for 3.5 days with either 200 mg dipyridamole (sustained release preparation), 25 mg acetylsalicylic acid, both drugs combined or placebo twice daily. 2. The mean area of all platelets/aggregates was reduced by 6.2% +/- 4.2% (+/- s.e. mean) by placebo (n = 23), 19.8% +/- 6.7% by dipyridamole (n = 22), 53.7% +/- 4.9% by acetylsalicylic acid (n = 23) and 71.4% +/- 3.7% by the combination of both drugs (n = 24), when compared with total inhibition of aggregation by EGTA. Thus, low-dose acetylsalicylic acid inhibited aggregation (P less than 0.001). 3. Dipyridamole reduced the size of platelet aggregates (P less than 0.01, two-fold analysis of variance). The reduction was correlated with the individual dipyridamole plasma levels (P less than 0.05, analysis of covariance). The subgroup of large and very large thrombi being formed was also reduced by dipyridamole (P less than 0.05). 4. This ex vivo study demonstrates that dipyridamole alone inhibits formation of thrombi on subendothelial matrix and enhances the inhibitory effect of low dose acetylsalicylic acid in this model of thrombosis. 相似文献