首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19887篇
  免费   1007篇
  国内免费   390篇
耳鼻咽喉   875篇
儿科学   555篇
妇产科学   343篇
基础医学   2639篇
口腔科学   1779篇
临床医学   1684篇
内科学   1666篇
皮肤病学   365篇
神经病学   1077篇
特种医学   1180篇
外国民族医学   4篇
外科学   3221篇
综合类   2389篇
现状与发展   1篇
预防医学   438篇
眼科学   847篇
药学   890篇
  12篇
中国医学   340篇
肿瘤学   979篇
  2024年   36篇
  2023年   221篇
  2022年   526篇
  2021年   634篇
  2020年   557篇
  2019年   494篇
  2018年   485篇
  2017年   514篇
  2016年   525篇
  2015年   570篇
  2014年   1023篇
  2013年   1079篇
  2012年   940篇
  2011年   976篇
  2010年   959篇
  2009年   966篇
  2008年   978篇
  2007年   920篇
  2006年   904篇
  2005年   835篇
  2004年   701篇
  2003年   631篇
  2002年   486篇
  2001年   483篇
  2000年   399篇
  1999年   411篇
  1998年   362篇
  1997年   371篇
  1996年   356篇
  1995年   287篇
  1994年   257篇
  1993年   255篇
  1992年   214篇
  1991年   217篇
  1990年   200篇
  1989年   187篇
  1988年   152篇
  1987年   130篇
  1986年   126篇
  1985年   152篇
  1984年   141篇
  1983年   64篇
  1982年   102篇
  1981年   106篇
  1980年   92篇
  1979年   64篇
  1978年   50篇
  1977年   40篇
  1976年   33篇
  1975年   25篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
腹腔镜肾上腺肿瘤切除术75例报告   总被引:2,自引:0,他引:2  
目的探讨腹腔镜下肾上腺肿瘤切除的方法和临床应用价值.方法1999年1月~2004年6月75例患者行腹腔镜肾上腺肿瘤切除术,其中采用经腹腔途径51例和经腹膜后途径24例.结果手术时间平均为(170.16±33.81)min,术中的出血量平均为(70.82±37.15)ml.术后平均住院时间为(5.87±1.01)d.中转开放手术2例(2.67%).发生并发症4例(5.33%),分别为膈肌损伤、胰腺损伤、肠道损伤、皮下血肿各1例.结论腹腔镜下行肾上腺肿瘤切除术具有创伤小,术中出血少,术后恢复快等优点,已经成为现代治疗肾上腺肿瘤的金标准.  相似文献   
62.
We have studied 20 pineal parenchymal tumors (PPT) and 4 normal or cystic pineal glands both by light and electron microscopy and immunohistochemistry with antibodies against glial markers [glial fibrillary acidic protein (GFAP) and protein S-100] or neural/neuroendocrine markers [neurofilaments (NF), synaptophysin and chromogranin A]. Light microscopy revealed the cellular organization of pinealocytes in the normal gland and in different morphological types of pineal tumors (typical pineocytomas, PPT with intermediate differentiation, mixed PPT exhibiting elements of both pineocytoma and pineoblastoma and pineoblastomas). Immunohistochemistry showed the presence of GFAP and protein S-100 in interstitial cells in nonneoplastic pineal gland. Cell processes were labeled with anti-synaptophysin and anti-NF antibodies. No immunoreactivity was found for chromogranin A in non-neoplastic pineal gland. In pineocytomas, GFAP and protein S-100 were observed in interstitial cells. Synaptophysin and NF were present in the large rosettes of pineocytomas. Synaptophysin, NF and chromogranin A were present in pineocytomas with a lobular arrangement of cells. Anti-chromogranin A immuno-reactivity was also seen in lobular areas of some PPT with intermediate differentiation. Analysis of normal human pineal gland by electron microscopy showed the presence of vesicle-crowned rodlets (VCR or synaptic ribbons), fibrous filaments (F), paired twisted filaments but few dense-core vesicles (DCV) in normal pinealocytes. Tumoral pineal cells appeared to differentiate either towards a neurosensory pathway characterized by the presence of sensory cells elements (VCR and F), or towards a neuroendocrine pathway, with the occurrence of many DCV. Immunogold labeling demonstrated the presence of chromogranin A in neurosecretory granules.Supported by grants from the Région Rhône Alpes and from INSERM (CJF 90-10)  相似文献   
63.
A unique example of a gingival salivary gland choristoma together with a gingival cyst is described in a human autopsy specimen of periodontal tissues. A choristoma is a tumor-like growth which is derived from primordial cells which have been displaced from their original tissue or organ. Only 6 other examples of the gingival salivary gland choristoma have been described in the world literature.  相似文献   
64.
Sialolipoma is a new variant of salivary gland lipoma, which was first proposed by Nagao et al. (Histopathology 2001; 38: 30) in 2001. We report this rare case of sialolipoma in the hard palate. A 60-year-old Japanese woman was referred to our department complaining of a painless swelling on the right side of the hard palate. Intra-oral examination revealed a soft, elastic, dome-shaped mass with 1 cm in diameter located in the posterior part of the hard palate. Magnetic resonance imaging examination revealed high intensity on T(1)-weighted image and isointensity on T(2)-weighted image. Incisional biopsy revealed that the tumor was encapsulated by fibrous tissue, consisted of adipose tissue, and also contained normal salivary gland tissue peripherally. First diagnosed as an ordinary lipoma of the hard palate, the tumor was excised. According to the recent criteria of histologic findings of sialolipoma, we rediagnosed the tumor as sialolipoma of the hard palate.  相似文献   
65.
婴儿先天性胆总管囊肿16例诊治分析   总被引:6,自引:0,他引:6  
1985 ̄1994年作者单位共收治小儿先天性胆总管囊肿105例,其中年龄小于12个月者16例,占15.2%,本病临床表现不典型,易延误诊治,超声检查可在产前检出本病,作者认为对于待续性黄疸的婴儿,保守治疗不宜时间过长,应积极手术探查。  相似文献   
66.
A mesenteric cyst with milk of calcium in an adult patient is presented. Preoperative evaluation included plain film, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). To our knowledge, the presence of milk of calcium in a mesenteric cyst has not been previously described.  相似文献   
67.
The possible occurrence of benzodiazepine-like substances in human breast milk was investigated in 35 healthy, newly delivered women who were known not to be taking benzodiazepines. Maternal blood samples and a sample of breast milk were obtained on the fifth post partum day. A radioreceptor technique (lower limit of detection 1.5 ng/ml; difference between duplicates at various concentrations <7%) was used for measuring benzodiazepine-like substances in blood and breast milk (with and without prior extraction). No benzodiazepine-like substances could be demonstrated in any of the blood samples taken from the 35 women. Measurable concentrations of benzodiazepine-like substances were demonstrated in all but 1 of the 35 breast milk samples. The mean concentration of benzodiazepine-like substances for all 35 women was 4.3±2.3 ng/ml (range 0–9.3 ng/ml) expressed as lorazepam. The corresponding value for extracted breast milk was 2.6±1.5 ng/ml (range 0–7.0 ng/ml). There was no association between concentrations of benzodiazepine-like substances in breast milk and maternal age, weight, height and body mass or parity, or the sex of the infant and infant birth weight. We suggest that non-detectable amounts of benzodiazepine-like substances in serum are concentrated in the mammillary glands and excreted in a higher concentration in breast milk. It is less likely that the relevant benzodiazepines are produced in the mammillary glands.  相似文献   
68.
166例涎腺腺样囊性癌的临床病理分析   总被引:1,自引:0,他引:1  
金蓉 《海南医学》2003,14(10):17-18
目的 分析涎腺腺样囊性癌的临床病理特点。方法 对166例涎腺腺样囊性癌行临床资料总结和HE组织学观察。结果 本组腺样囊性癌占涎腺上皮性肿瘤的11.5%,占涎腺癌的27.0%;男性略多于女性;中年以上好发;发生于小涎腺者多于大涎腺,以腭部为最常见;腺样型103例,管状型42例,实性型2l例;Ⅰ级17例,Ⅱ级128例,Ⅲ级2l例。结论 需与基底细胞腺癌、涎腺导管癌、多形性低度恶性腺癌、上皮-肌上皮癌鉴别诊断;浸润性极强是其显著特点,手术治疗以局部大块切除为主要原则。  相似文献   
69.
Sequential salivary gland scintigraphy with 99mTc-technetium pertechnetate (Tc-99) is a safe, minimally invasive test for study of major salivary glands. However, its relationship to salivary function has not been investigated in detail. We have investigated the relationship between major salivary gland flow rates and Tc-99 scans and developed a new rating scale using scans of a control group with normal salivary function. Salivary flow rates and Tc-99 scans were obtained from healthy, non-medicated subjects (n = 33) and from xerostomic patients (n = 22). There were significant differences between the groups for salivary flow rates and Tc-99 ratings. Significant correlations were found between salivary flow rates and Tc-99 ratings in the control and xerostomic groups. The Tc-99 rating scale proved reliable in assessing salivary dysfunction, and showed a high inter-examiner correlation. These results demonstrate the usefulness of salivary gland scintigraphy in assessing major salivary gland flow rates and the utility of a new rating scale.  相似文献   
70.
动脉瘤样骨囊肿   总被引:1,自引:0,他引:1  
动脉瘤样骨囊肿属骨的瘤样病变。本文将16年来收检的16例、结合文献复习,阐明其定义,好发部位和年龄;阐述其富有特征性的临床病理表现。作者赞同Lichtenstein的观点,认为此病是由某种原因造成的局部循环障碍,导致病变骨内静压明显升高,形成扩张充血的血管床病变而造成。研究探讨这些血循环障碍引起的不同结果,可能对病因学有重要价值。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号