全文获取类型
收费全文 | 1857960篇 |
免费 | 130880篇 |
国内免费 | 4247篇 |
专业分类
耳鼻咽喉 | 24262篇 |
儿科学 | 60503篇 |
妇产科学 | 50341篇 |
基础医学 | 263307篇 |
口腔科学 | 54354篇 |
临床医学 | 162292篇 |
内科学 | 372156篇 |
皮肤病学 | 43956篇 |
神经病学 | 144753篇 |
特种医学 | 67653篇 |
外国民族医学 | 272篇 |
外科学 | 277055篇 |
综合类 | 39840篇 |
现状与发展 | 4篇 |
一般理论 | 576篇 |
预防医学 | 140093篇 |
眼科学 | 43476篇 |
药学 | 134870篇 |
7篇 | |
中国医学 | 5140篇 |
肿瘤学 | 108177篇 |
出版年
2021年 | 16599篇 |
2019年 | 17287篇 |
2018年 | 25209篇 |
2017年 | 18481篇 |
2016年 | 19872篇 |
2015年 | 22460篇 |
2014年 | 30901篇 |
2013年 | 44778篇 |
2012年 | 63535篇 |
2011年 | 66746篇 |
2010年 | 38864篇 |
2009年 | 35720篇 |
2008年 | 60692篇 |
2007年 | 64438篇 |
2006年 | 64441篇 |
2005年 | 61696篇 |
2004年 | 58891篇 |
2003年 | 55894篇 |
2002年 | 53693篇 |
2001年 | 96208篇 |
2000年 | 98497篇 |
1999年 | 80884篇 |
1998年 | 20802篇 |
1997年 | 18066篇 |
1996年 | 18119篇 |
1995年 | 17358篇 |
1994年 | 15791篇 |
1993年 | 14540篇 |
1992年 | 59127篇 |
1991年 | 56907篇 |
1990年 | 54386篇 |
1989年 | 51985篇 |
1988年 | 47261篇 |
1987年 | 46033篇 |
1986年 | 43286篇 |
1985年 | 40917篇 |
1984年 | 30053篇 |
1983年 | 25523篇 |
1982年 | 14257篇 |
1979年 | 26169篇 |
1978年 | 18017篇 |
1977年 | 15296篇 |
1976年 | 14271篇 |
1975年 | 15081篇 |
1974年 | 18220篇 |
1973年 | 17562篇 |
1972年 | 16193篇 |
1971年 | 14993篇 |
1970年 | 13940篇 |
1969年 | 13002篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Effect of impact exercise on bone mineral density in elderly women with low BMD: a population-based randomized controlled 30-month intervention 总被引:4,自引:3,他引:1
Raija Korpelainen Sirkka Keinänen-Kiukaanniemi Jorma Heikkinen Kalervo Väänänen Juha Korpelainen 《Osteoporosis international》2006,17(1):109-118
Evidence of the effect of exercise on bone loss comes mainly from studies in voluntary postmenopausal women, and no population-based, long-term interventions have been performed. The purpose of this population-based, randomized, controlled trial was to determine the effect of long-term impact exercise on bone mass at various skeletal sites in elderly women with low bone mineral density (BMD) at the radius and hip. Participants ( n =160) were randomly assigned to 30 months either of supervised and home-based impact exercise training or of no intervention. The primary outcome measures were femoral neck, trochanter and total hip BMD, and the secondary outcomes were bone density measures at the radius and calcaneum. Outcomes were assessed at baseline, 12 months and 30 months using blinded operators. The analyses were performed on an intention-to-treat analysis. Mean femoral neck and trochanter BMD decreased in the control group [–1.1%, 95% confidence interval (CI) –0.1% to –2.1% and –1.6%, 95% CI –0.4% to –2.7%], while no change occurred in the exercise group. Mean trochanter BMC decreased more in the control group (–7.7%, 95% CI –9.7% to –5.6% vs. –2.9%, 95% CI –5.3 to –0.9). There were six falls that resulted in fractures in the exercise group and 16 in the control group during the 30-month intervention ( P =0.019). A significant bone loss occurred in both groups at the radius and calcaneum. In multivariate analysis, weight gain was associated with increased BMD and BMC at all femur sites both in the exercise group and in the pooled groups. In conclusion, impact exercise had no effect on BMD, while there was a positive effect on BMC at the trochanter. Exercise may prevent fall-related fractures in elderly women with low bone mass.There was no conflict of interest. 相似文献
992.
G K Zherlov S V Kozlov N S Rudaia T G Zherlova 《Experimental & clinical gastroenterology》2006,(3):44-50, 71
The article presents an original method of laparoscopic anti-reflux surgery, immediate and long-term results of the treatment of 132 patients with esophageal opening hernia. It also describes the analysis of the life quality of patients with the gastroesophageal reflux disease before and after the surgery. 相似文献
993.
Among many conventional techniques, nuclear techniques have shown to be faster, more reliable, and more effective in detecting explosives. In the present work, neutrons from a 5 Ci Am-Be neutron source being in water tank are captured by elements of soil and landmine (TNT), namely (14)N, H, C, and O. The prompt capture gamma-ray spectrum taken by a NaI (Tl) scintillation detector indicates the characteristic photo peaks of the elements in soil and landmine. In the high-energy region of the gamma-ray spectrum, besides 10.829 MeV of (15)N, single escape (SE) and double escape (DE) peaks are unmistakable photo peaks, which make the detection of concealed explosive possible. The soil has the property of moderating neutrons as well as diffusing the thermal neutron flux. Among many elements in soil, silicon is more abundant and (29)Si emits 10.607 MeV prompt capture gamma-ray, which makes 10.829 MeV detection difficult. The Monte Carlo simulation was used to adjust source-target-detector distances and soil moisture content to yield the best result. Therefore, we applied MCNP4C for configuration very close to reality of a hidden landmine in soil. 相似文献
994.
995.
P B Schneider U Denk M Breitenbach K Richter P Schmid-Grendelmeier S Nobbe M Himly A Mari C Ebner B Simon-Nobbe 《Clinical and experimental allergy》2006,36(12):1513-1524
BACKGROUND: Alternaria alternata is one of the most important allergenic fungi worldwide. Mannitol dehydrogenase (MtDH) has previously been shown to be a major allergen of Cladosporium herbarum and cross-reactivity has been demonstrated for several fungal allergens. OBJECTIVE: The present study's objective was to clone the MtDH from an A. alternata cDNA library, express and purify the recombinant non-fusion protein and test its IgE-binding properties. Methods A cDNA library prepared from A. alternata hyphae and spores was screened for mannitol dehydrogenase by DNA hybridization with the radioactively labelled C. herbarum homologue as a probe. The resulting clone was sequenced and heterologously expressed in Escherichia coli as a recombinant non-fusion protein, which was purified to homogeneity and analysed for its IgE-binding capacity. RESULTS: The coding sequence of the full-length cDNA clone comprises 798 bp encoding a protein with a molecular mass of 28.6 kDa and a predicted pI of 5.88. Protein sequence analysis revealed an identity of 75% and a homology of 86% between the MtDHs of A. alternata and C. herbarum. The functional mannitol dehydrogenase was expressed in the E. coli strain BL21(DE3) transformed with the vector pMW172 and purified to homogeneity. The enzyme catalyses the NADPH-dependent conversion of d-fructose to d-mannitol. In IgE-ELISA and immunoblots, MtDH is recognized by 41% of A. alternata-allergic patients. In vivo immunoreactivity of the recombinant MtDH was verified by skin prick testing. Finally, inhibition-ELISA experiments confirmed cross-reactivity between the MtDHs of A. alternata and C. herbarum. CONCLUSION: Mannitol dehydrogenase (Alt a 8) represents an important new allergen of the ascomycete A. alternata that might be suitable for improving diagnostic and therapeutic procedures. 相似文献
996.
997.
Guntur E Luis Chee-Khuen Yong Deepak A Singh S Sengupta David SK Choon 《Journal of orthopaedic surgery and research》2007,2(1):22-10
Background
Acromioclavicular injuries are common in sports medicine. Surgical intervention is generally advocated for chronic instability of Rockwood grade III and more severe injuries. Various methods of coracoclavicular ligament reconstruction and augmentation have been described. The objective of this study is to compare the biomechanical properties of a novel palmaris-longus tendon reconstruction with those of the native AC+CC ligaments, the modified Weaver-Dunn reconstruction, the ACJ capsuloligamentous complex repair, screw and clavicle hook plate augmentation. 相似文献998.
M Nakanishi Y Demura S Mizuno S Ameshima Y Chiba I Miyamori H Itoh M Kitaichi T Ishizaki 《The European respiratory journal》2007,29(3):453-461
High-resolution computed tomography (HRCT) findings in patients with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) are varied and nonspecific. There is no known report of changes in HRCT findings and respiratory function test results for RB-ILD patients following the cessation of smoking. Five patients with RB-ILD, confirmed by surgical lung biopsy, were retrospectively studied. Each stopped cigarette smoking and did not receive corticosteroid therapy after diagnosis. The clinical symptoms, respiratory function test results and HRCT findings obtained at the final observation were compared with those from the time of diagnosis. Ground-glass opacity and centrilobular nodules corresponding to pathological respiratory bronchiolitis, as well as intralobular fine linear-reticular opacity corresponding to fibrosis involving the subpleural alveolar septa, showed computed tomography-pathological correlations. Both clinical symptoms and the diffusing capacity of the lungs for carbon monoxide improved significantly following smoking cessation, as did ground-glass opacity and centrilobular nodules seen during the initial HRCT examination. Centrilobular nodules and ground-glass opacity, which are the main features of high-resolution computed tomography of respiratory bronchiolitis-associated interstitial lung disease patients and represent pathological respiratory bronchiolitis, can be improved by smoking cessation. The diffusing capacity of the lung for carbon monoxide in respiratory function tests can be also improved. 相似文献
999.
César Roux was one of the few universal surgeons at the end of the 19th century who dominated all fields of surgery and influenced current surgery with his innovative spirit. Pioneering spirit and the story of the success of modern surgery are linked with his name. On the occasion of his 150th birthday, we recall the memory of this great surgeon. The personality and the history of Professor César Roux form a part of our medical and surgical heritage. 相似文献
1000.