全文获取类型
收费全文 | 221800篇 |
免费 | 69630篇 |
国内免费 | 2465篇 |
专业分类
耳鼻咽喉 | 5877篇 |
儿科学 | 9122篇 |
妇产科学 | 2937篇 |
基础医学 | 19624篇 |
口腔科学 | 6544篇 |
临床医学 | 37709篇 |
内科学 | 68168篇 |
皮肤病学 | 14086篇 |
神经病学 | 26315篇 |
特种医学 | 8356篇 |
外科学 | 53898篇 |
综合类 | 362篇 |
现状与发展 | 72篇 |
一般理论 | 26篇 |
预防医学 | 10855篇 |
眼科学 | 4668篇 |
药学 | 6920篇 |
中国医学 | 1035篇 |
肿瘤学 | 17321篇 |
出版年
2024年 | 516篇 |
2023年 | 4842篇 |
2022年 | 1374篇 |
2021年 | 4668篇 |
2020年 | 11179篇 |
2019年 | 13042篇 |
2018年 | 15849篇 |
2017年 | 17103篇 |
2016年 | 18643篇 |
2015年 | 18697篇 |
2014年 | 25657篇 |
2013年 | 26428篇 |
2012年 | 9394篇 |
2011年 | 9561篇 |
2010年 | 18222篇 |
2009年 | 18717篇 |
2008年 | 7894篇 |
2007年 | 5210篇 |
2006年 | 7726篇 |
2005年 | 4809篇 |
2004年 | 4016篇 |
2003年 | 2984篇 |
2002年 | 3134篇 |
2001年 | 4575篇 |
2000年 | 3701篇 |
1999年 | 3494篇 |
1998年 | 3732篇 |
1997年 | 3539篇 |
1996年 | 3417篇 |
1995年 | 3258篇 |
1994年 | 2003篇 |
1993年 | 1610篇 |
1992年 | 1412篇 |
1991年 | 1441篇 |
1990年 | 1083篇 |
1989年 | 1206篇 |
1988年 | 1041篇 |
1987年 | 872篇 |
1986年 | 906篇 |
1985年 | 742篇 |
1984年 | 578篇 |
1983年 | 554篇 |
1982年 | 559篇 |
1981年 | 444篇 |
1980年 | 411篇 |
1979年 | 345篇 |
1978年 | 362篇 |
1977年 | 427篇 |
1975年 | 306篇 |
1972年 | 319篇 |
排序方式: 共有10000条查询结果,搜索用时 734 毫秒
931.
BACKGROUND: The maximum number of hair grafts that can be safely implanted in 1 cm2 is still debatable. To our knowledge, no previous report has addressed this issue in three dimensions, taking into account the size, the angle of the graft, and the intergraft distance. OBJECTIVES: To study the effect of the size and angle of the graft and the intergraft distance on dense packing. METHODS: Using a mathematical formula (the maximum number of hair grafts in 1 cm2 = 33 * cosine), the volume of the recipient area and the volume of the hair graft are calculated, assuming that the surface area of the recipient area is 1 cm2, the diameter of the hair graft is 1 mm, and the intergraft distance is 1.5 mm laterally and 1 mm anteriorly and posteriorly. RESULTS: The maximum number of hair grafts that could be implanted in 1 cm2 at a 90 angle in relation to the skin surface is 33 grafts, at a 60 angle is 28 grafts, and at a 30 angle is 16 grafts. CONCLUSION: The maximum number of hair grafts that can be implanted in any given recipient area depends on the graft size, the angle or direction of these grafts, and the intergraft distance. Where more space is allowed between the grafts, and the more acute the angle, the fewer hair grafts that can be implanted. 相似文献
932.
Hatta Naohito MD PhD † Morita Reiji MD PhD Yamada Mizuki MD Takehara Kazuhiko MD PhD Ichiyanagi Kenji MD PhD ‡ Yokoyama Kunihiko MD PhD ‡ 《Dermatologic surgery》2005,31(3):327-330
BACKGROUND: Although there is lymphatic flow into the popliteal fossa from a skin tumor located in the lower leg, popliteal metastasis is extremely rare. Recently, sentinel lymph nodes outside traditional nodal basins have been identified. This study investigated the incidence of sentinel nodes in the popliteal region and the indication for biopsy. METHODS: Fourteen patients with various skin cancers involving the lower extremities (nine melanomas, four squamous cell carcinomas, and one sweat gland carcinoma) underwent lymphoscintigraphy and excision with sentinel lymph node biopsy. RESULTS: In all 14 patients, hot spots showed accumulation in the groin region. Five of 14 patients (36%) demonstrated popliteal sentinel nodes in addition to the inguinal nodes. Three of five popliteal sentinel nodes were histologically studied. A patient with acral melanoma demonstrated micrometastasis of melanoma cells in a popliteal node but not in the groin node. CONCLUSION: This study demonstrates that sentinel lymph nodes located in the popliteal fossa are frequently detected by lymphoscintigraphy and that biopsy should be performed if popliteal nodes are identified. 相似文献
933.
BACKGROUND: The efficacy of compression therapy depends mainly on the exerted pressure and on the stiffness of the material. OBJECTIVE: To propose a simple method by which pressure and stiffness can be assessed in the individual patient. MATERIAL AND METHODS: Using a pressure transducer (Kikuhime small probe, MediTrade, Soro, Denmark) the sub-bandage pressure is measured on the medial aspect of the lower leg at the transition of the gastrocnemius muscle into the Achilles' tendon. The pressure difference between active standing and lying is defined as the static stiffness index (SSI). Results: The accuracy and precision of the probe are good. Unna boot bandages (Lohmann-Rauscher, Vienna, Austria) and multilayer short-stretch bandages show a significantly higher SSI than long-stretch bandages and round-knitted class II stockings. The SSI values are lower than 10 mm Hg for elastic, long-stretch material and higher than 10 mm Hg for inelastic, short-stretch material. CONCLUSION: In future compression trials, pressure and stiffness measured in vivo should be declared. 相似文献
934.
935.
Q-Switched Alexandrite Laser Therapy for Pigmentation of the Lips Owing to Laugier-Hunziker Syndrome 总被引:2,自引:0,他引:2
Ozawa Toshiyuki MD Fujiwara Masao MD † Harada Teruichi MD Muraoka Michinari MD Ishii Masamitsu MD 《Dermatologic surgery》2005,31(6):709-712
BACKGROUND: Laugier-Hunziker (LH) syndrome is a rare benign condition in which hyperpigmentation of the lips and buccal mucosa occurs with no systemic associations. OBJECTIVE: We report the response to treatment with the Q-switched alexandrite laser (QSAL) because there are few reports on therapy for LH syndrome. METHODS: The QSAL was used for pigmentation of the lips in a 63-year-old woman with LH syndrome. Laser irradiation was done at 5.0 J/cm2 with a 3 mm spot size. RESULTS: There was 100% clearance of pigmentation of the lips with a single laser treatment, and recurrence was not observed after 6 months. CONCLUSION: The QSAL is very effective for pigmentation owing to LH syndrome. 相似文献
936.
937.
938.
939.
940.