全文获取类型
收费全文 | 1405743篇 |
免费 | 102378篇 |
国内免费 | 1920篇 |
专业分类
耳鼻咽喉 | 18267篇 |
儿科学 | 44992篇 |
妇产科学 | 38446篇 |
基础医学 | 209880篇 |
口腔科学 | 39805篇 |
临床医学 | 126328篇 |
内科学 | 279254篇 |
皮肤病学 | 31165篇 |
神经病学 | 113549篇 |
特种医学 | 50244篇 |
外国民族医学 | 266篇 |
外科学 | 194747篇 |
综合类 | 26435篇 |
现状与发展 | 3篇 |
一般理论 | 592篇 |
预防医学 | 122057篇 |
眼科学 | 31743篇 |
药学 | 103883篇 |
6篇 | |
中国医学 | 2625篇 |
肿瘤学 | 75754篇 |
出版年
2021年 | 11932篇 |
2019年 | 12834篇 |
2018年 | 18018篇 |
2017年 | 13213篇 |
2016年 | 14121篇 |
2015年 | 16173篇 |
2014年 | 21598篇 |
2013年 | 32858篇 |
2012年 | 46793篇 |
2011年 | 49680篇 |
2010年 | 27957篇 |
2009年 | 25902篇 |
2008年 | 45668篇 |
2007年 | 48789篇 |
2006年 | 47946篇 |
2005年 | 46773篇 |
2004年 | 44598篇 |
2003年 | 42496篇 |
2002年 | 41035篇 |
2001年 | 59558篇 |
2000年 | 61034篇 |
1999年 | 51156篇 |
1998年 | 14032篇 |
1997年 | 12661篇 |
1996年 | 13025篇 |
1995年 | 12254篇 |
1994年 | 11402篇 |
1992年 | 39872篇 |
1991年 | 39198篇 |
1990年 | 37978篇 |
1989年 | 36573篇 |
1988年 | 33971篇 |
1987年 | 33205篇 |
1986年 | 31755篇 |
1985年 | 29924篇 |
1984年 | 22786篇 |
1983年 | 19894篇 |
1982年 | 11747篇 |
1979年 | 21904篇 |
1978年 | 16063篇 |
1977年 | 13431篇 |
1976年 | 12455篇 |
1975年 | 13539篇 |
1974年 | 16505篇 |
1973年 | 16311篇 |
1972年 | 15428篇 |
1971年 | 14441篇 |
1970年 | 13617篇 |
1969年 | 12976篇 |
1968年 | 12164篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Sodium MRI of the human kidney at 3 Tesla. 总被引:6,自引:0,他引:6
Nimrod Maril Yael Rosen Glenn H Reynolds Alex Ivanishev Long Ngo Robert E Lenkinski 《Magnetic resonance in medicine》2006,56(6):1229-1234
The sodium concentration gradient in the kidney (from the cortex to the medulla) serves to regulate fluid homeostasis and is tightly coupled to renal function. It was previously shown that renal function and pathophysiology can be characterized in rat kidneys by measuring the sodium gradient with (23)Na MRI. This study demonstrates for the first time the ability of (23)Na MRI to map the distribution of sodium in the human kidney and to quantify the corticomedullary sodium gradient. The study was performed on a 3T Signa LX scanner (GE) using an in-house-built quadrature surface coil. (23)Na images of volunteers were acquired using a 3D coronal gradient-echo sequence at a spatial resolution of 0.3 x 0.3 x 1.5 cm(3) in a 25-min scan time. The signal intensity (relative to the noise) increased linearly from the cortex to each of the medullae with a mean slope of 1.6 +/- 0.2 in relative arbitrary units per mm (Rel.u./mm, N = 6) and then decreased, as expected, toward the renal pelvis. Water deprivation (12 hr) induced a significant increase of 25% (P < 0.05) in this gradient. Based on these results, we suggest that sodium MRI can serve as a valuable noninvasive method for functional imaging of the human kidney. 相似文献
992.
993.
Adorján F Kovács 《Journal of cranio-maxillo-facial surgery》2006,34(2):74-84
BACKGROUND: In an attempt to raise the survival of an unselected and representative population of oral and oropharyngeal squamous cell cancer patients, a pilot study of an integrated four-modality treatment was conceived. Final endpoints were compliance, loco-regional control, survival (after complete 5-year follow-up), and a concept of trial assessment using the treatment-dependent prognostic index TPI. PATIENTS: Eighty-seven consecutive patients with histologically proven untreated stages I-IV disease presented in the period between 1997 and 1999 of whom 14 had to be considered uncurable and 73 were fit to be treated with the intention of achieving a cure. METHODS: All patients received one cycle of neoadjuvant intraarterial chemotherapy with 150 mg/m(2) cisplatin (systemically neutralized with sodium thiosulphate), and, if possible, by consecutive treatment applying both surgery of the primary tumour and the neck lymphatics, as well as by adjuvant radiation over 5 weeks (51.3 Gy) plus concurrent chemotherapy (weekly systemic docetaxel 25 mg/m(2)). RESULTS: Ninety per cent of all cases and 96% of the patients treated with curative intention received more than one modality due to study design. Patient non-compliance in the group treated with curative intention has been 18/73 (=25%), and protocol compliance has been 32/73 (=44%). The locoregional control rate for all cases was 71% (62/87 patients) and for the patients treated with curative intention 83.5% (61/73 patients). Thirteen/fourteen non-curable patients died after a mean period of 4 months. After a median observation time of 5 years, the final absolute survival of the unselected population was 53%, and of the patients treated with curative intention 62% (especially, 70% and 50% for patients with operable stages III and IV, respectively). CONCLUSION: The multimodality regimen as presented proved feasible and showed high objective and relative survival rates in comparison with known data from tumour registries of unselected populations. Intra-arterial chemotherapy should be considered a valuable addition to treatment. The potential of survival benefit from this multimodality regimen in comparison with the prognosis index TPI should be investigated in further studies. 相似文献
994.
995.
996.
997.
998.
999.