全文获取类型
收费全文 | 280007篇 |
免费 | 23437篇 |
国内免费 | 6617篇 |
专业分类
耳鼻咽喉 | 3782篇 |
儿科学 | 7022篇 |
妇产科学 | 5908篇 |
基础医学 | 25054篇 |
口腔科学 | 8420篇 |
临床医学 | 25333篇 |
内科学 | 28739篇 |
皮肤病学 | 3275篇 |
神经病学 | 15518篇 |
特种医学 | 7383篇 |
外国民族医学 | 19篇 |
外科学 | 25241篇 |
综合类 | 43320篇 |
现状与发展 | 18篇 |
一般理论 | 30篇 |
预防医学 | 35052篇 |
眼科学 | 3891篇 |
药学 | 27634篇 |
417篇 | |
中国医学 | 32067篇 |
肿瘤学 | 11938篇 |
出版年
2024年 | 1181篇 |
2023年 | 5281篇 |
2022年 | 9896篇 |
2021年 | 13149篇 |
2020年 | 12668篇 |
2019年 | 13841篇 |
2018年 | 12298篇 |
2017年 | 10946篇 |
2016年 | 10053篇 |
2015年 | 9415篇 |
2014年 | 18114篇 |
2013年 | 19406篇 |
2012年 | 16469篇 |
2011年 | 17757篇 |
2010年 | 14266篇 |
2009年 | 12496篇 |
2008年 | 11787篇 |
2007年 | 11907篇 |
2006年 | 10317篇 |
2005年 | 8809篇 |
2004年 | 7380篇 |
2003年 | 6632篇 |
2002年 | 5201篇 |
2001年 | 4533篇 |
2000年 | 3951篇 |
1999年 | 3364篇 |
1998年 | 2825篇 |
1997年 | 2597篇 |
1996年 | 2226篇 |
1995年 | 2157篇 |
1994年 | 1882篇 |
1993年 | 1682篇 |
1992年 | 1522篇 |
1991年 | 1421篇 |
1990年 | 1293篇 |
1989年 | 1209篇 |
1988年 | 1051篇 |
1987年 | 931篇 |
1986年 | 937篇 |
1985年 | 2308篇 |
1984年 | 2536篇 |
1983年 | 1581篇 |
1982年 | 2093篇 |
1981年 | 1511篇 |
1980年 | 1337篇 |
1979年 | 1167篇 |
1978年 | 937篇 |
1977年 | 735篇 |
1976年 | 859篇 |
1975年 | 597篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
101.
目的:观察盐酸托烷思琼对预防脑动脉瘤栓塞术患者术后恶心呕吐(PONV)的有效性和安全性。方法:选择行颅内动脉瘤栓塞术患者45例,随机分为3组,每组15例,于手术结束前30分钟A组患者缓慢静注盐酸托烷思琼5mg,B组患者缓慢静注盐酸托烷思琼3mg,C组患者给予生理盐水。术后观察并记录以下指标:(1)术后24h内恶心呕吐发生率及强度;(2)术后2、8h镇静评分(OAA/S);(3)术后2、8h平均动脉压(MAP),心率(HR);(4)各组不良反应的发生情况。结果:术后24h内两治疗组恶心呕吐发生率显著低于对照组,差异有统计学意义(P<0.05或P<0.01)。托烷思琼5mg组恶心呕吐发生率略低于3mg组,但差异无统计学意义(P>0.05)。结论:托烷思琼可降低脑动脉瘤栓塞术患者术后恶心呕吐的发生率。托烷思琼3mg不仅可以减少药物用量,而且能减少副作用的发生,是一种经济、有效、安全的止吐方法。 相似文献
102.
Fujihiko Iwata M.D. Yoshio Hanawa M.D. Hirotada Takashima M.D. Keichou Shimoura M.D. Youhei Nishibayashi M.D. 《Pediatrics international》1992,34(1):84-86
The pathogenesis and etiology of Kawasaki disease are unknown, but some studies suggest increased genetic susceptibility. The case is presented of an infant with Kawasaki disease whose father suffered from the same illness 21 years previously. The A, B and C loci of the HLA antigens were examined. 相似文献
103.
104.
Two topical corticosteroids, budesonide (BUD) and beclomethasone dipropionate (BDP), both administered as suspensions in water, were investigated in healthy volunteers regarding influence on cortisol in plasma and urine (U-cortisol) after nasal application. In the first study, single doses of 200, 400, and 800 μg of BDP and BUD were given at 10:00 pm. In the second study, 100, 200, and 400 μg were given mornings and evenings for 4 days. In the single-dose study, none of the drugs or doses showed any significant influence on cortisol in plasma. However, U-cortisol decreased significantly after BUD 400 and 800 μg. In the multidose study, U-cortisol values were significantly reduced after all doses of BUD and the highest dose of BDP. The compounds tested showed different ability to cause measurable systemic effects after nasal application. The clinical implication is that the prescriber, when choosing a compound, should take the application site into consideration and should also be encouraged to find the lowest effective dose. 相似文献
105.
Epidemiology of multiple sclerosis in the county of Vestfold, eastern Norway: incidence and prevalence calculations 总被引:2,自引:0,他引:2
The county of Vestfold in the South-eastern part of Norway has undergone two incidence and prevalence surveys on multiple sclerosis. The prevalence of definite/probable MS on January 1.1963 was 61.6/100000. Based on the same diagnostic criteria, the present study reports a slight increase in prevalence to 86.4/100000 on January 1st 1983. The average annual incidence was calculated for 5 years periods from 1953 to 1983. The time periods 1953–1962 and 1973–1977 showed age-adjusted incidence rates between 4.50 and 5.49/100000 while the 10–year period 1963–1972 showed significantly lower rates. The fluctuating pattern of MS incidence and prevalence over time supports the view that MS is not a stable disease, and that exogenous factors are influencing the disease pattern. 相似文献
106.
LYNDA E ALBERTYN 《Journal of Medical Imaging and Radiation Oncology》1992,36(1):17-22
Both systemic and local therapy, for conditions of the breast and unrelated to it, may produce manuno-graphic changes. Some of these are characteristic, such as the pattern of scarring seen in reduction mammo-plasty. In many other instances, however, the changes produced overlap features commonly seen in malignancy. A knowledge of the timing, natural history and spectrum of these changes will aid mammographic interpretation. 相似文献
107.
Andreas Jovanovic Engelbert A.J.M. Schulten Isaäc van der Waal 《Community dentistry and oral epidemiology》1992,20(2):94-96
The referral pattern of 140 Dutch patients with oral mucosal lesions, who had been referred to a Department of Oral & Maxillofacial Surgery and Oral Pathology, shows that patients with oral mucosal lesions consult the dentist as often as the family doctor as the first source of help or information. Furthermore, family doctors were much more used to refer patients with oral mucosal disease to medical specialists rather than to the dentist or the oral and maxillofacial surgeon. 相似文献
108.
小包装全氟丙烷气体动力学实验研究 总被引:1,自引:0,他引:1
为检验塑料小包装全氟丙烷气体(C3F8)在不同包装和储存方法时浓度变化,将装有5~7mlC3F8的聚氯乙烯小袋,根据不同储藏温度和外包装方法随机分成四组:(1)22℃聚乙烯外包装,(2)36℃聚乙烯外包装,(3)22℃铝箔真空外包装,(4)-29℃聚乙烯外包装;每一组C3F8小袋气体存放一定时间后,应用气相色谱分析方法进行浓度测量。结果:第3组C3F8浓度最高和稳定,第2组浓度随放置时间降低最明显,第4组是临床应用气体的储藏和包装方法,其30天样本浓度和第3组相等,但放置一年时浓度降低。结果显示:塑料小包装C3F8予以铝箔真空外包装是一种可行的方法,利于C3F8运输和普及;聚乙烯外包装的C3F8,应放在-29℃保存,时间不超过一年。 相似文献
109.
H. Isoniemi J. Ahonen B. Eklund K. Höckerstedt K. Salmela E. von Willebrand P. Häyry 《Transplant international》1990,3(1):121-127
Abstract. A prospective randomized study was conducted to evaluate the impact of four different conversion protocols on graft outcome in long-term follow-up. Between January 1986 and May 1987, 128 patients with first cadaveric kidney allografts were randomized at the time of transplantation to four treatment groups of 32 patients each, to be assigned 10 weeks post-transplantation. During the first 10 weeks, all patients received triple therapy with low-dose azathioprine (Aza), cyclosporin (CyA), and methylprednisolone (MP). After 10 weeks, one group continued with triple therapy (group A) while the three other groups received different combinations of two drugs, namely, Aza and CyA (group B), Aza and MP (group C), or CyA and MP (group D). Withdrawal of MP (group B) or especially of CyA (group C) was associated with 4/29 (14%) and 10/28 (36%) acute rejection episodes, respectively, for 60 days after conversion. All rejections were mild and reversible. There were no rejections after Aza withdrawal or in the group that continued on triple therapy during the corresponding time period. The most common reason for dropping out after withdrawal, for those patients who could not continue on the originally randomized medication, was azathioprine intolerance (n= 12). Five patients were switched back to triple therapy after CyA withdrawal due to rejection. Steroid intolerance was rare and CyA in low doses was very well tolerated. At 1 year there were no statistically significant differences in graft survival between groups A, B, C, and D-81 %, 88%, 88%, and 88%, respectively-or in patient survival-88%, 88%, 88%, and 97%, respectively. For those patients continuing with the originally randomized treatment protocol, there were no differences in patient or graft survival either, the means being 91% and 89%, respectively. The most common cause of death after withdrawal was cardiovascular in nature, and there were no more fatal infections under triple drug treatment than with double drug regimens. There were no statistically significant differences in mean serum creatinine values at 1 year. The median serum creatinine values for groups A, B, C, and D were 112, 132, 133, and 133 μmol/l, respectively. At 1 year the mean CyA dose in the groups that continued with CyA was 3. 5–4. 2 mg/kg per day and CyA concentrations were equal. 相似文献
110.
Systolic and diastolic blood pressures were measured on 254 monozygotic (MZ) and 260 dizygotic (DZ) male twin pairs, during middle age (average age 48 years) and at two later age points. Genetic and environmental components of covariation were modeled by time series. For both measures, shared environmental influences were absent and specific environmental influences were largely time-specific. Although heritability was about 0.5 at each time point, genetic variation present at middle age contributed only about 60% to that present 9 years later, the remaining 40% being new. Fifteen years later, at the third time point, no new genetic variation was evident, variation in individual differences being entirely attributable to genetic differences laid down at the two earlier ages. © 1993 Wiley-Liss, Inc. 相似文献