全文获取类型
收费全文 | 13893篇 |
免费 | 936篇 |
国内免费 | 22篇 |
学科分类
医药卫生 | 14851篇 |
出版年
2021年 | 167篇 |
2020年 | 112篇 |
2019年 | 161篇 |
2018年 | 229篇 |
2017年 | 148篇 |
2016年 | 175篇 |
2015年 | 164篇 |
2014年 | 266篇 |
2013年 | 409篇 |
2012年 | 565篇 |
2011年 | 561篇 |
2010年 | 297篇 |
2009年 | 334篇 |
2008年 | 509篇 |
2007年 | 564篇 |
2006年 | 564篇 |
2005年 | 508篇 |
2004年 | 500篇 |
2003年 | 469篇 |
2002年 | 495篇 |
2001年 | 499篇 |
2000年 | 473篇 |
1999年 | 381篇 |
1998年 | 159篇 |
1997年 | 125篇 |
1996年 | 127篇 |
1995年 | 128篇 |
1994年 | 131篇 |
1992年 | 399篇 |
1991年 | 392篇 |
1990年 | 386篇 |
1989年 | 327篇 |
1988年 | 343篇 |
1987年 | 354篇 |
1986年 | 324篇 |
1985年 | 295篇 |
1984年 | 196篇 |
1983年 | 196篇 |
1982年 | 118篇 |
1981年 | 116篇 |
1980年 | 96篇 |
1979年 | 205篇 |
1978年 | 176篇 |
1977年 | 123篇 |
1976年 | 102篇 |
1975年 | 119篇 |
1974年 | 133篇 |
1973年 | 129篇 |
1972年 | 116篇 |
1971年 | 103篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
Computed tomography (CT) has become essential in the diagnostic evaluation of the female pelvic. CT allows accurate delineation of neoplastic and inflammatory processes and provides an effective means of guiding percutaneous needle biopsy of masses and aspiration/drainage of fluid collections. In the pregnant woman, pelvimetry and excretory urography can be performed using the CT scout view with a radiation dose significantly lower than with conventional x-ray techniques. This paper covers the clinically relevant technical considerations involved in performing CT on women and follows with an overview of normal female pelvic anatomy and frequently encountered pathologic conditions. 相似文献
54.
A Cattaneo A De Marco L Sonni G L Bracco P Carli G L Taddei 《Minerva ginecologica》1992,44(11):567-571
The paper describes a study carried out in 40 patients affected by lichen sclerosus (LS) of the vulva. The mean age of patients was 60.9 years (range 27-83) and 31 were in menopause. Patients were divided randomly into two groups of 20. The symptoms (itching, burning, pain, dyspareunia), clinical aspects (atrophy, hyperkeratosis, sclerosis) and histological alterations (atrophy of the epithelium, edema, inflammatory infiltrate, fibrosis) were quantified in each patient by a score. The mean scores relating to the three parameters examined were then calculated for each group. One group was treated with testosterone propionate 2% and the other with a strong synthetic corticosteroid, clobetasol dipropionate 0.05%. After 24 weeks of treatment patients were again evaluated in relation to clinical (symptoms and clinical aspects) and histological parameters, following the procedure used before the start of treatment. The mean scores obtained were then compared with those before the start of treatment. Statistical analyses were performed using Student's t-test. Testosterone was found to be effective in relation to symptoms but no significant change was observed in relation to clinical aspects and histological alterations. It also caused major secondary effects which led to the suspension of treatment in one patient. Clobetasol was shown to be highly effective both in relation to symptoms and in terms of clinical aspects and histological alterations, and did not cause any noteworthy collateral effects, especially contact dermatitis. In the context of the objective parameters examined in this study, sclerosis and hyperkeratosis were easily modified by corticosteroid treatment in comparison to atrophy, especially in those patients with a longer duration of disease.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
55.
56.
57.
G N Coston R B Sayetta H I Friedman M C Weinrich C A Macera K Meeks S K McAndrews K S Morales 《The Cleft palate-craniofacial journal》1992,29(1):87-91
The correct identification of syndromes and other congenital malformations at an early age is critical for the child, family and care providers. Most specialists who conduct large screenings of young children are not adequately trained to recognize signs and symptoms that should lead to appropriate referral to the clinical geneticist and/or diagnostic team. A systematic approach for recognizing important signs is presented here; a Craniofacial Screening Profile. Following a brief training program, the Profile was validated by 39 speech-language pathologists in screening 3,539 kindergarten and first grade children. The results were excellent (specificity was 99.6%), demonstrating that with limited training, specialists can effectively screen for important signs and symptoms of a major group of syndromes and other congenital malformations. 相似文献
58.
A. Ferretti E. Monaco L. Labianca F. D’Angelo A. De Carli F. Conteduca 《Journal of orthopaedics and traumatology》2006,7(3):136-141
Healing of a tendon graft to a bone tunnel is slower than the healing of a bone plug. Therefore, the device chosen for hamstring
fixation may need to maintain its strength and stiffness longer than the device chosen for bone-tendon-bone fixation. We evaluated,
in an extraarticular ovine model, how 4 and 12 weeks of implantation affect the strength of a tendon graft fixed to bone with
the Evolgate. The long digital extensor tendon was transplanted and fixed with the Evolgate into a 30-mm long, 8 mm diameter
bone tunnel drilled in the tibial metaphysis of both posterior limbs of 15 skeletally mature Suffolk sheep. Immediately after
implantation, and 4 and 12 weeks later, biomechanical cyclic load tests in 50 N increments were performed until failure to
evaluate the ultimate failure load (UFL). Histological analysis was also performed at 4 and 12 weeks. Biomechanical tests
revealed a UFL of 339±120 N at time 0, and increases to 635±19 N (4 weeks) and to 867±80 N (12 weeks). The differences between
all 3 groups were significant (p<0.001, paired t test). The histological evaluation showed a layer of cellular, fibrous tissue between the tendon and the bone, along the
length of the bone tunnel; this layer progressively matured and reorganized during the healing process. The collagen fibers
that attached the tendon to the bone resembled Sharpey’s fibers. The strength of the interface significantly and progressively
increased between weeks 4 and 12 after transplantation, and was associated with a degree of bone ingrowth noted histologically.
The use of the Evolgate seems not to interfere with the bone ingrowth after implantation, allowing an improvement in strength
of the bonetendon- device complex. 相似文献
59.
Alfred S. Friedman Shirley Bransfield Cheryl Kreisher 《The American journal on addictions / American Academy of Psychiatrists in Alcoholism and Addictions》1994,3(4):325-336
The authors report on the relationship of early adolescent substance use (up to the time of the 16th birthday) to educational-vocational performance in the early adulthood of 612 African-American urban subjects. Voluminous prospective data were available on the behavior, test performance, and families of 612 urban African-American subjects, from birth up to 7 years of age. Scarcer prospective data were available for school performance during later years of school. Control variables were derived from these data to determine the amount of variance in each dependent educational-vocational outcome variable that was accounted for, independently of the amount of variance accounted for by early substance use. (American Journal on Addictions 1994; 3:325–336) 相似文献
60.