全文获取类型
收费全文 | 53924篇 |
免费 | 3342篇 |
国内免费 | 249篇 |
专业分类
耳鼻咽喉 | 528篇 |
儿科学 | 1043篇 |
妇产科学 | 726篇 |
基础医学 | 7028篇 |
口腔科学 | 1114篇 |
临床医学 | 5762篇 |
内科学 | 11668篇 |
皮肤病学 | 1064篇 |
神经病学 | 6442篇 |
特种医学 | 2684篇 |
外科学 | 9014篇 |
综合类 | 352篇 |
一般理论 | 14篇 |
预防医学 | 2510篇 |
眼科学 | 735篇 |
药学 | 3261篇 |
中国医学 | 73篇 |
肿瘤学 | 3497篇 |
出版年
2023年 | 449篇 |
2022年 | 718篇 |
2021年 | 1459篇 |
2020年 | 873篇 |
2019年 | 1316篇 |
2018年 | 1499篇 |
2017年 | 1176篇 |
2016年 | 1417篇 |
2015年 | 1638篇 |
2014年 | 2055篇 |
2013年 | 2528篇 |
2012年 | 4081篇 |
2011年 | 4099篇 |
2010年 | 2447篇 |
2009年 | 2231篇 |
2008年 | 3557篇 |
2007年 | 3661篇 |
2006年 | 3376篇 |
2005年 | 3348篇 |
2004年 | 2944篇 |
2003年 | 2857篇 |
2002年 | 2581篇 |
2001年 | 647篇 |
2000年 | 517篇 |
1999年 | 549篇 |
1998年 | 520篇 |
1997年 | 401篇 |
1996年 | 336篇 |
1995年 | 275篇 |
1994年 | 258篇 |
1993年 | 210篇 |
1992年 | 239篇 |
1991年 | 233篇 |
1990年 | 204篇 |
1989年 | 192篇 |
1988年 | 183篇 |
1987年 | 147篇 |
1986年 | 156篇 |
1985年 | 185篇 |
1984年 | 180篇 |
1983年 | 147篇 |
1982年 | 118篇 |
1981年 | 97篇 |
1980年 | 89篇 |
1979年 | 122篇 |
1978年 | 92篇 |
1977年 | 101篇 |
1976年 | 89篇 |
1974年 | 104篇 |
1973年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Axel Stäbler M.D. Richard G. H. Baumeister M.D. Ulrike Szeimies Ulrich Fink M.D. Hermann Berger M.D. 《Skeletal radiology》1994,23(2):103-106
Post-traumatic ulnar carpal translocation is a rare, severe ligamentous injury to the wrist. Radiologic findings include widening of the radiocarpal joint space at the radial styloid process and ulnar displacement of the carpus. Less than 50% of the lunate articulates with the radius in the neutral position; the lunate is tilted dorsally with palmar subluxation due to a ruptured radioscapholunate (RSL) ligament. This malposition should be called rotatory palmar subluxation of the lunate (RPSL), by analogy to rotatory subluxation of the scaphoid (RSS). In contrast to dorsiflexed intercalated segment instability (DISI), in RPSL the RSL ligament is ruptured and, in the majority of cases, the scapholunate ligament remains intact. A prompt diagnosis should lead to successful treatment. 相似文献
92.
The effects of rigid contact lens base curve radius changes on tear pump efficiency were determined by measuring oxygen uptake on six with-the-rule corneas (with toricities between 0.37 and 1.00 D) under three conditions: (1) normal open eye, (2) after 5 min of static (without blinking) wear of polymethyl methacrylate (non-gas permeable) contact lenses, and (3) after 5 min of dynamic (with blinking once every 5 s) wear of the same lenses. The difference between the oxygen uptake rates measured under static and dynamic conditions provides an index of tear pump efficiency. Each subject wore a series of five lenses: fitted on K and 0.05 or 0.10 mm steeper and flatter than the flattest corneal meridian. The overall diameter of all lenses was 8.8 mm, the optic zone was 7.4 mm, the axial edge lift was 0.09 mm, and all other parameters were constant. The contact lens fitted on K was associated with the greatest central corneal oxygen debt under static conditions, whereas the same lens also provided for the best tear exchange with the blink. In addition, better tear exchange was found to be associated with larger palpebral aperture sizes. 相似文献
93.
94.
95.
Christian Linden Henrik G Ahlborg Jack Besjakov Per Gardsell Magnus K Karlsson 《Journal of bone and mineral research》2006,21(6):829-835
This 2-year prospective controlled exercise intervention trial in 99 girls at Tanner stage 1, evaluating a school curriculum-based training program on a population-based level, showed that the annual gain in BMC, aBMD, and bone size was greater in the intervention group than in the controls. INTRODUCTION: Most exercise intervention studies in children, evaluating the accrual of BMD, include volunteers and use specifically designed osteogenic exercise programs. The aim of this study was to evaluate a 2-year general school-based exercise intervention program in a population-based cohort of girls at Tanner stage 1. MATERIALS AND METHODS: Forty-nine girls 7-9 years of age in grades 1 and 2 in one school were included in a school curriculum-based exercise intervention program of general physical activity for 40 minutes per school day (200 minutes/week). Fifty healthy age-matched girls in three neighboring schools, assigned to the general Swedish school curriculum of physical activity (60 minutes/week), served as controls. All girls were premenarchal, remaining in Tanner stage 1 during the study. BMC (g) and areal BMD (aBMD; g/cm2) were measured with DXA of the total body (TB), the lumbar spine (L2-L4 vertebrae), the third lumbar vertebra (L3), the femoral neck (FN), and the leg. Volumetric BMD (vBMD; g/cm3) and bone size were calculated at L3 and FN. Total lean body mass and total fat mass were estimated from the total body scan. Height and weight were also registered. Baseline measurements were performed before the intervention was initiated. Follow-up was done after 2 years. RESULTS: No differences between the groups were found at baseline in age, anthropometrics, or bone parameters. The annual gain in BMC was greater in the intervention group than in the controls: L2-L4, mean 3.8 percentage points (p = 0.007); L3 vertebra, mean 7.2 percentage points (p < 0.001); legs, mean 3.0 percentage points (p = 0.07). The intervention group had a greater annual gain in aBMD: total body, mean 0.6 percentage points (p = 0.006), L2-L4, mean 1.2 percentage points (p = 0.02), L3 vertebra, mean 1.6 percentage points (p = 0.006); legs, mean 1.2 percentage points (p = 0.007). There was also a greater mean annual gain in bone size in the L3 vertebra (mean 1.8 percentage points; p < 0.001) and in the FN (mean 0.3 percentage points; p = 0.02). CONCLUSIONS: A general school-based exercise program for 2 years for 7- to 9-year-old girls (baseline) enhances the accrual of BMC and BMD and increases bone size. 相似文献
96.
97.
98.
The lipid-lowering agents, statins, are the most commonly prescribed class of drugs in the western world. Because of their
widespread use, many patients undergo surgical procedures while on statins. Statins, in addition to cholesterol-lowering effects,
also have anticoagulant, immunosuppressive, and antiproliferative properties that may affect the risk of local wound complications.
This study investigated the relationship between statins and postoperative wound complications in a large cohort of patients
undergoing inguinal or ventral hernia repair. Data mining was performed in the Veterans Integrated Service Network (VISN)16
Data Warehouse. This database contains clinical and demographic information about all veterans cared for at the ten VA Medical
Centers that comprise the South Central VA Healthcare Network in the mid-south region of the US. Aggregate data (age, body
mass index, smoking history, gender, race, history of diabetes, statin use, and postoperative wound complications) were obtained
for all patients who underwent inguinal or ventral hernia repair during the period October 1, 1996–November 30, 2004. During
the period of the query, 10,782 patients (10,676 male, 106 female), 1,242 (11.5%) of whom received statins, underwent herniorrhaphy.
Statin use did not affect the risk of wound infection or delayed wound healing. Statin use was, however, associated with an
increased rate of local postoperative bleeding complications (P=0.01). When the type of hernia, age, smoking, diabetes, and body mass index were included in a multivariate analysis, statins
remained borderline significant as an independent predictor of wound hematoma/postoperative bleeding (P=0.04), odds ratio 1.6 (95% CI 1.03–2.44). Patients who undergo inguinal herniorrhaphy while on statins have an increased
risk of postoperative wound hematoma/hemorrhage. Focus on additional factors that may affect the propensity to postoperative
bleeding and on meticulous intraoperative hemostasis are particularly important in such patients. 相似文献
99.
Regina Kirchweger Robert Zeillinger Christian Schneeberger Paul Speiser Genevive Louason Charles Theillet 《International journal of cancer. Journal international du cancer》1994,56(2):193-199
Chromosome 17 is a frequent target during breast-cancer formation and progression. It has been shown to be affected by allele losses at multiple sites, as well as by DNA amplification. Our aim was to delineate a map of the genetic alterations on chromosome 17 in a given set of breast tumors. To this end we analyzed 151 pairs of tumor and cognate lymphocyte DNAs by Southern blotting with 5 RFLP or VNTR probes and by PCR at 8 CA repeat polymorphic loci for LOHs. Moreover, we studied DNA amplification of the evi2, erbB2, thra1, gcsf and rara genes. Data presented here point strongly to the existence of 5 distinct regions of allele losses on chromosome 17:2 on 17p, 3 on 17q. Of the 2 regions on 17p, one involves tp53 while the second is located more distally toward the telomere. LOH was found in 45.9% and 58.8% respectively. The 3 regions on 17q are located: (i) on the proximal portion of the long arm band q21, corresponding to the brcal region; (ii) in a central region defined by the marker D17S74; (iii) on the distal part of 17q (band q25) characterized by losses of the marker D17S24. Each of these regions presented respectively allele losses in 47.5%, 33.3% and 40.8% of the informative tumors. Whereas some tumors presented patterns of LOH consistent with the loss of a complete chromosomal arm or of large portions of the chromosome, a high proportion of the analyzed tumors showed interstitial losses. Amplifications were found in 15% of the tumors and were centered around erbB2. An altered chromosome 17 (bearing an LOH or a DNA amplification) was found in more than 80% of the breast tumor set analyzed here and multiple anomalies affecting this chromosome were often detected in the same sample. 相似文献
100.