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   67054篇
  免费   5712篇
  国内免费   2653篇
耳鼻咽喉   812篇
儿科学   1616篇
妇产科学   1211篇
基础医学   6617篇
口腔科学   1251篇
临床医学   6363篇
内科学   6231篇
皮肤病学   910篇
神经病学   2354篇
特种医学   3738篇
外国民族医学   52篇
外科学   8273篇
综合类   11334篇
现状与发展   19篇
预防医学   1934篇
眼科学   644篇
药学   4646篇
  48篇
中国医学   1989篇
肿瘤学   15377篇
  2024年   176篇
  2023年   994篇
  2022年   2191篇
  2021年   2837篇
  2020年   2285篇
  2019年   2030篇
  2018年   1902篇
  2017年   2182篇
  2016年   2445篇
  2015年   2618篇
  2014年   4054篇
  2013年   4074篇
  2012年   3713篇
  2011年   4123篇
  2010年   3336篇
  2009年   3380篇
  2008年   3401篇
  2007年   3644篇
  2006年   3249篇
  2005年   2887篇
  2004年   2496篇
  2003年   2108篇
  2002年   1956篇
  2001年   1763篇
  2000年   1447篇
  1999年   1317篇
  1998年   1147篇
  1997年   1056篇
  1996年   932篇
  1995年   849篇
  1994年   705篇
  1993年   567篇
  1992年   449篇
  1991年   392篇
  1990年   319篇
  1989年   304篇
  1988年   296篇
  1987年   244篇
  1986年   181篇
  1985年   240篇
  1984年   216篇
  1983年   126篇
  1982年   177篇
  1981年   157篇
  1980年   111篇
  1979年   105篇
  1978年   71篇
  1977年   47篇
  1976年   49篇
  1972年   30篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
In this study, we examine the prevalence of finding isolated tumor cells (ITCs) in negative lymph nodes of endometrial cancer patients using immunohistochemistry. Seventy-six endometrial cancer patients with lymph nodes histologically negative for metastatic disease were examined. Nodal tissue sections were stained with anticytokeratin antibodies AE-1 and CAM 5.2. Nodes with single or groups of cells (two to four cells) < or =0.2 mm and showing cytokeratin reactivity were positive for ITCs. Findings were compared to features of the primary tumor and patient outcome. ITCs were present in 31 of 1712 lymph nodes. Fifteen (19.7%) patients had ITC-positive nodes. ITCs involved only pelvic nodes in nine cases, only para-aortic nodes in five cases, and pelvic and para-aortic in one case. Tumor in adnexa was the only pathologic feature associated with nodal ITCs (P= 0.0485). All 15 patients with nodal ITCs were alive at follow-up. One (6.7%) patient suffered recurrent disease but was alive at last encounter. Disease recurred in 5 (8.8%) of 57 patients without nodal ITCs. Two are alive without disease, two alive with disease, and one died from her cancer. In summary, a significant proportion of endometrial cancer patients have ITCs detected by immunohistochemistry in histologically negative regional lymph nodes.  相似文献   
12.
This paper examines the effect of patient age, tumour grade and extent of surgery on the outcome of treatment of 278 patients with high grade malignant gliomas referred to the Queensland Radium Institute between 1980 and 1987. The aim was to determine whether the extent of surgical resection alters survival rates. The extent of surgery had no effect on survival except for those patients with grade 3 tumours in whom a total excision was possible. Those in whom only a biopsy was done did not have a worse prognosis. Grading was found to be of importance, as patients with grade 3 tumours had a better survival than those with grade 4 tumours. In grade 4 tumours, those under 30 years of age had a better survival than those over 30 years, whereas with grade 3 tumours there was a gradation of age effect (under 40 years best, then 40–49 years, and those 50 years and over doing worst).  相似文献   
13.
鼻部源性突眼的CT分析   总被引:1,自引:0,他引:1  
目的:为了提高对鼻部源性突眼的认识。材料和方法:本文19例鼻部源性突眼,其中鼻咽癌7例,鼻咽纤维血管瘤2例,鼻腔纤维血管瘤、恶性肉芽肿和嗅神经母细胞瘤各1例,上颌窦癌和软骨肉瘤各2例,上颌窦恶性肉芽肿、纤维肉瘤和恶性纤维组织细胞瘤各1例,全部病例均作轴位CT扫描,12例加作增强扫描,详细分析了它们CT表现。结果:源于鼻咽的放疗前鼻咽癌和纤维血管瘤,其病变主要位于鼻咽腔和咽旁,后者显著增强并有钙斑,与前者不同;源于上颌窦的肿瘤,病变占据上颌窦的全部或大部分,软骨肉瘤有钙斑且无强化,易与其它肿瘤区别,它们破坏上颌窦顶部进入眼眶;鼻腔嗅神经母细胞瘤在鼻腔和筛窦形成肿块,破坏筛骨眶板侵入眼眶。结论:根据CT所见,可判断突眼原因。  相似文献   
14.
Noninvasive localized proton magnetic resonance spectroscopy (MRS) was used for differential diagnosis of a focal brain lesion in a 2.5-year-old girl. The clinical signs were a mild head tilt and neck pain. Magnetic resonance imaging (MRI) revealed a lesion in the right hemisphere of the cerebellum, but its nature remained obscure. In this lesion quantitative determinations of cerebral metabolites by fully relaxed, short-echo-time proton MRS revealed markedly lowered N-acetylaspartate (NAA) and pronounced elevations of choline-containing compounds (Cho) and myo-inositol (Ins), whereas metabolite concentrations in cortical gray matter and white matter were within normal ranges. The metabolite pattern of the lesion indicated loss of vital neuroaxonal tissue (low NAA) and enhanced glial proliferation (high Cho and Ins), which, together with the MRI morphology, suggested a brain tumor. The diagnosis was established by neurosurgical exploration and total extirpation of the tumor. Histology confirmed an astrocytoma (WHO II). After 2 weeks' recovery the child was discharged with no neurological signs.  相似文献   
15.
分析原发性腹膜后恶性肿瘤12例。83%以腹块和腹痛为主要症状,体征中腹块占91.5%,以恶性淋巴瘤居首位占61%。全组完全切除率为58%,行脏器联合切除占25%。完全切除加放疗、化疗3年存活率为28.5%,部分切除及活检未给其它治疗者5例预后差,均1年内死亡,差别显著。  相似文献   
16.
A case of papilliferous keratoameloblastoma is reported which is only the second ever documented. The patient was a 76-yr-old black woman with a large expansile multilocular radiolucency of the body, angle and ramus of the mandible. Histologically the lesion consisted of sheets of cystic follicles filled with necrotic debris and sometimes parakeratin. The vast majority of the follicles were lined by a papilliferous epithelium consisting of large rounded cells with centrally placed nuclei. True papillary projections with cores of connective tissue were also present. The remainder of the follicles were lined by a thin parakeratinising stratified squamous epithelium. Histological features characteristic of ameloblastoma were absent. Final classification of these lesions will have to await the reporting of further cases.  相似文献   
17.
HCC的早期诊断是其治疗的关键,HCC血清标志物的检测又为其诊断提供了有利的途径,并且操作简单,敏感性高和特异性强。目前常用的血清标志物为AFP、AFP变异体、AFP mRNA、AFU、GGT、DCP、AIF、GPC3等。这些标志物的联合使用有助于HCC的诊断及预后。  相似文献   
18.
骨外型牙源性钙化上皮瘤1例报告   总被引:2,自引:0,他引:2  
牙源性钙化上皮瘤是一种良性肿瘤,也称Pindborg瘤,可分为骨内型和骨外型2种,主要发生于颌骨内,偶见于颌骨外。本文报告1例发生于口底的牙源性钙化上皮瘤,其临床症状与口底皮样囊肿相似.术后经组织病理学确诊,主要组织病理学特征是嗜酸性环状钙化团块。因其具有局部侵袭性,为避免复发,提倡完整切除肿物。  相似文献   
19.
20.
目的 评价子宫动脉栓塞术治疗子宫肌瘤的近期疗效。方法 89例子宫肌瘤患者,采用Seldinger技术分别作左右子宫动脉主干插管检查和栓塞治疗,栓塞剂采用聚乙稀醇颗粒(PVA)或白芨混合颗粒。结果 72例(80.9%)完成随访,随访时间1~28个月。有94.1%(64/68)的患者月经复常;治疗后瘤体缩小25.2%~76.8%(M=41.3%)。除了术中术后疼痛(65例)和发热(16例)外,有2例因肌瘤坏死行子宫切除术,1例出现卵巢早衰。结论 子宫动脉栓塞术治疗子宫肌瘤的近期疗效满意,远期疗效尚待进一步观察。  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