全文获取类型
收费全文 | 4427篇 |
免费 | 221篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 104篇 |
妇产科学 | 110篇 |
基础医学 | 424篇 |
口腔科学 | 102篇 |
临床医学 | 359篇 |
内科学 | 1108篇 |
皮肤病学 | 44篇 |
神经病学 | 159篇 |
特种医学 | 191篇 |
外国民族医学 | 1篇 |
外科学 | 788篇 |
综合类 | 120篇 |
一般理论 | 3篇 |
预防医学 | 301篇 |
眼科学 | 130篇 |
药学 | 340篇 |
中国医学 | 14篇 |
肿瘤学 | 345篇 |
出版年
2023年 | 46篇 |
2022年 | 141篇 |
2021年 | 240篇 |
2020年 | 97篇 |
2019年 | 136篇 |
2018年 | 181篇 |
2017年 | 93篇 |
2016年 | 90篇 |
2015年 | 127篇 |
2014年 | 169篇 |
2013年 | 204篇 |
2012年 | 315篇 |
2011年 | 306篇 |
2010年 | 203篇 |
2009年 | 155篇 |
2008年 | 252篇 |
2007年 | 266篇 |
2006年 | 245篇 |
2005年 | 237篇 |
2004年 | 164篇 |
2003年 | 162篇 |
2002年 | 156篇 |
2001年 | 63篇 |
2000年 | 77篇 |
1999年 | 49篇 |
1998年 | 27篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 11篇 |
1993年 | 19篇 |
1992年 | 46篇 |
1991年 | 43篇 |
1990年 | 41篇 |
1989年 | 25篇 |
1988年 | 25篇 |
1987年 | 21篇 |
1986年 | 30篇 |
1985年 | 13篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 13篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1970年 | 10篇 |
1969年 | 11篇 |
1968年 | 7篇 |
排序方式: 共有4668条查询结果,搜索用时 15 毫秒
1.
2.
3.
Farid Saad 《Asian journal of andrology》2015,17(1):58-60
It is no exaggeration to say that our conceptualization of the (patho-) physiological functions of testosterone has undergone a revolutionary development over the last three decades. The traditional thinking was that the biological functions of testosterone were restricted mainly to the area of reproduction and male sexuality. However, scientific research has clearly demonstrated that testosterone is a multi-system hormone serving a wide range of hitherto unsuspected biological functions.In line with this, it will be argued in this contribution that the physiological role of testosterone has been underestimated, while the risks of testosterone administration have been overstated. Space does not permit to elaborate extensively on all new insights of the role of testosterone in the biology of the male. Three areas will be addressed: (1) the role that testosterone can play in body weight management of hypogonadal men; (2) the role of testosterone in inflammatory processes; (3) the strategy required to let patients benefit from the recent insights that testosterone is a multi-system hormone whose use should not be limited to reproductive/sexual medicine. 相似文献
4.
5.
In addition to a working knowledge of general complications such as thromboembolism and infective endocarditis, optimal care of the patient with a prosthetic valve requires specific knowledge concerning the characteristics of a given patient's prosthesis. This may need to include the ability to identify the valve roentgenographically when history and records are unavailable. A 53-year-old woman with mitral stenosis secondary to rheumatic heart disease and status post a reported Bjork-Shiley mitral valve (MV) replacement 17 years prior to hospital admission was referred for evaluation of severe hemolytic anemia. Previous cinefluoroscopy in 1986 at the time of a cerebrovascular accident revealed a normally functioning caged disc prosthesis and not the tilting disc of a Bjork-Shiley prosthetic valve. The valve was not further characterized and she continued receiving warfarin therapy until May 1989 when she presented with laboratory findings showing a marked hemolytic anemia with a hemoglobin of 6.5 mg/dl and lactate dehydrogenase (LDH) value of 2100 IU. Echocardiography revealed normal valvular function without evidence of perivalvular leak. The patient was referred for further evaluation with chest roentgenogram at the time of hospital admission revealing a valve configuration characteristic of the Beall model 103/104 series that has been found to manifest progressive disc variance with a high degree of hemolytic anemia (despite normal noninvasive evaluation of MV function), disc tilting with intermittent regurgitation, and catastrophic disc embolization in extreme cases. The precise identification of valvular prosthesis in patients after valve replacement is crucial for optimal management. As in our case, the mere identification of a particular valve may necessitate certain management and therapy based on the natural history of that valve. In the absence of reliable history and/or records, the roentgenographic examination should lead to the precise identification. 相似文献
6.
O S Giordano M J Pestchanker E Guerreiro J R Saad R D Enriz A M Rodríguez E A Jáuregui J Guzmán A O María G H Wendel 《Journal of medicinal chemistry》1992,35(13):2452-2458
The structural requirements for the gastric cytoprotective activity of several sesquiterpene lactones are reported. A theoretical-experimental study on the potentially active centers is carried out. The biological evaluation of reduced analogues and the simulation of the molecular interactions between these compounds and an endogenous cysteine residue suggest that the presence of a non sterically hindered Michael acceptor seems to be an essential structural requirement for the cytoprotective activity in this family of compounds. This observation suggests that cytoprotection is mediated through a Michael reaction between the sulfhydryl-containing peptides of the mucosa and Michael acceptors present in the molecules under study. This mechanism of action is in addition to and distinct from the one proposed in our previous paper, namely, that these sesquiterpenes stimulate endogenous synthesis of prostaglandins. 相似文献
7.
R A Price K Lunetta R Ness M A Charles M F Saad E Ravussin P H Bennett D J Pettitt W C Knowler 《International journal of obesity (2005)》1992,16(11):851-857
We examined distribution characteristics of the body mass index (BMI; weight/height; kg/m2) in a sample of 1128 male and 1372 female Pima Indians aged 15-65 years. We found that women had a higher mean and variance of BMI than men. From commingling analyses, we determined that the distribution of BMI could be accounted for either by a single skewed distribution or by a mixture of multiple normal components. These component distributions may be used to define provisional thresholds in selecting families for genetic studies. To ensure genetic segregation of obesity predisposing genes in Pima families will require that some members have BMIs > or = 40 kg/m2. 相似文献
8.
9.
Abdel Wahab M. Ibrahim Saad M. Al-Rajeh Upendra Mohan Chowdhary Ahmed Ammar 《Neurosurgical review》1990,13(2):103-107
There are significant variations among countries in the incidence of brain abscess. We report here 26 cases of brain abscess treated at the Neurosurgery Department of King Faisal University and Dammam Central Hospital Saudi Arabia over a six year period (1982–1988). This is 2.3% of total admissions to the two neurosurgery departments serving a population of approximately 1.2 million in the same period.Young males were most often affected (M/F ratio 3.3:1; 31% were less than 15 years old, 46% aged between 15–39 years, and 23% older than 40 years). Streptococcus was found to be the most common microorganism (38.4%). Mixed infection was seen in 15.3%, and sterile abscesses were found in 11.5% of the patients after aerobic and anaerobic cultures of the pus. Chronic otitis media and paranasal sinusitis predisposed the patients to abscess formation in 57.6% of the cases. The temporo-parietal area was the commonest site. Epilepsy was a complication in 30.7% of our patients, and the mortality rate was 15.3%. 相似文献
10.
S A Kandil I Spahn B Scholten Z A Saleh S M M Saad H H Coenen S M Qaim 《Applied radiation and isotopes》2007,65(5):561-568
Excitation functions were measured by the stacked-foil technique for (nat)Rb(alpha,xn)(87m,87m+g,88)Y and (nat)Sr(alpha,xn)(86,88,89)Zr reactions from their respective thresholds up to 26 MeV. The samples for irradiation were prepared by sedimentation and pellet pressing techniques. The measured data were compared with those available in the literature. From the excitation functions, integral yields of the products were calculated. The suitable energy ranges for the production of (87)Y and (88)Y via (nat)Rb(alpha,xn) processes and of (89)Zr via the (nat)Sr(alpha,xn) process are E(alpha)=26-->20 MeV, E(alpha)=26-->5 MeV and E(alpha)=20-->8.5 MeV, respectively. The respective yields amount to 8.2, 0.08 and 0.9 MBq/microA h. Production of (88)Y is feasible if a waiting time of about 2 months is allowed to let the impurities decay out. Also, (87)Y can be produced with a relatively low impurity of (88)Y. The yields of both (88)Y and (87)Y via the present routes are, however, appreciably lower than those via the (nat)Sr(p,xn) processes. There is a possibility to produce (89)Zr via the alpha-particle irradiation of (nat)Sr. The yield is rather low but would be considerably increased if enriched (86)Sr would be used as target material. The radionuclidic impurity levels in all the three products are discussed. 相似文献