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   5194篇
  免费   261篇
  国内免费   37篇
耳鼻咽喉   44篇
儿科学   82篇
妇产科学   63篇
基础医学   649篇
口腔科学   80篇
临床医学   303篇
内科学   1508篇
皮肤病学   43篇
神经病学   429篇
特种医学   194篇
外科学   938篇
综合类   37篇
预防医学   147篇
眼科学   138篇
药学   335篇
中国医学   9篇
肿瘤学   493篇
  2023年   24篇
  2022年   44篇
  2021年   88篇
  2020年   41篇
  2019年   63篇
  2018年   85篇
  2017年   74篇
  2016年   73篇
  2015年   88篇
  2014年   121篇
  2013年   150篇
  2012年   276篇
  2011年   299篇
  2010年   168篇
  2009年   166篇
  2008年   265篇
  2007年   305篇
  2006年   288篇
  2005年   314篇
  2004年   307篇
  2003年   281篇
  2002年   289篇
  2001年   147篇
  2000年   138篇
  1999年   143篇
  1998年   73篇
  1997年   48篇
  1996年   48篇
  1995年   45篇
  1994年   49篇
  1993年   41篇
  1992年   101篇
  1991年   73篇
  1990年   75篇
  1989年   93篇
  1988年   83篇
  1987年   65篇
  1986年   51篇
  1985年   56篇
  1984年   41篇
  1983年   42篇
  1982年   21篇
  1981年   17篇
  1980年   23篇
  1979年   24篇
  1977年   19篇
  1976年   16篇
  1973年   17篇
  1969年   18篇
  1966年   15篇
排序方式: 共有5492条查询结果,搜索用时 15 毫秒
91.
92.
93.
Abstract Background: Yolk sac tumors (YST) exhibit several different histological subtypes and the mechanisms of cellular differentiation and prognosis of each subtype remain unknown.
Results: We report two infants with sacrococcygeal YST; one represented a typical histological subtype and the other showed a hepatoid subtype with uniform histology. The isoform of alpha-fetoprotein (AFP) in the patient with the hepatoid pattern was examined by lectin-affinity Immunoelectrophoresis and represented as a YST. but not hepatocellular, subtype. The patient with typical YST responded well to VAB-6 combination chemotherapy. However, this regimen was only partially effective to the patient with the pure hepatoid histological subtype, and an etoposide with ifosfamide and cisplatin (VIP) regimen as a salvage chemotherapy combined with complete tumor resection was useful to achieve complete remission (CR). Both of the patients have been in CR for more than four years.  相似文献   
94.
Urinary bladder cancers occurring after prolonged cyclophosphamide therapy are being increasingly reported. Cyclophosphamide-induced cancer in the upper urinary tract is not, however, generally recognized. We report a case of asynchronous development of transitional cell carcinoma in the bladder and renal pelvis, after prolonged cyclophosphamide therapy for non-Hodgkin's lymphoma. To date, at least 8 cyclophosphamide-related cancers have been reported in the upper tract. These cases are reviewed briefly.  相似文献   
95.
96.
Pulmonary amyloidosis is a rare pulmonary lesion. We report a 42-year-old male admitted for further evaluation of abnormal chest shadow. A chest CT demonstrated a nodular shadow in right S3. We tried transbronchial and percutaneous lung biopsy, but could not diagnose. We performed partial lung resection by video-assisted thoracoscopic surgery. Pathological diagnosis of the lesion was pulmonary amyloidosis. Immunohistochemical examination revealed this amyloid composed of AL kappa protein. No clinical evidence of amyloid deposits were found in other organs. We finally diagnosed this case as a localized nodular pulmonary amyloidosis.  相似文献   
97.
Buerger's disease is an inflammatory occlusive vascular disorder involving small- and medium-sized arteries in the distal extremities and is usually complicated with thrombophlebitis. Since Buerger's disease develops most frequently in men who smoke, pregnancy complicated with this disease is extremely rare. Only three pregnancies have been reported previously. All cases indicate that Buerger's disease worsens during pregnancy. However, anti-coagulant therapy appeared to be effective in this case. Accordingly, careful observation is mandatory in pregnancies complicated with Buerger's disease.  相似文献   
98.
PURPOSE: To evaluate the relationship between mutations of the epidermal growth factor receptor (EGFR) gene and the effectiveness of gefitinib treatment in patients with recurrent lung cancer after pulmonary resection. PATIENTS AND METHODS: We sequenced exons 18-21 of the EGFR gene using total RNA extracted from 59 patients with lung cancer who were treated with gefitinib for recurrent lung cancer. Gefitinib effectiveness was evaluated by both imaging studies and change in serum carcinoembryonic antigen (CEA) levels. RESULTS: EGFR mutations were found in 33 patients (56%). Of these mutations, 17 were deletions around codons 746-750 and 15 were point mutations (12 at codon 858, three at other codons), and one was an insertion. EGFR mutations were significantly more prevalent in females, adenocarcinoma, and never-smokers. Gefitinib treatment resulted in tumor shrinkage and/or CEA decrease to less than half of the baseline level in 26 patients, tumor growth and/or CEA elevation in 24 patients, and gefitinib effect was not assessable in nine patients. Female, never-smoking patients with adenocarcinoma tended to respond better to gefitinib treatment. Gefitinib was effective in 24 of 29 patients with EGFR mutations, compared with two of 21 patients without mutations (P < .0001). Of note, del746-750 might be superior to L858R mutations for prediction of gefitinib response. Patients with EGFR mutations survived for a longer period than those without the mutations after initiation of gefitinib treatment (P = .0053). CONCLUSION: EGFR mutations were a good predictor of clinical benefit of gefitinib in this setting.  相似文献   
99.
100.
Microtubule disassembling agents (MDAs) such as colchicine (COL) and vincristine sulfate (VCR) are known to be cardiotoxic. However, few attempts have been made to histopathologically examine cardiac lesions induced by MDAs. In this study, we endeavored to induce myocardial injury in rats by administering MDAs and to clarify the morphological features of these myocardial lesions. Male rats were intravenously administered COL (1.00 or 1.25 mg/kg for 2 days at single daily doses) or VCR (0.50 or 0.75 mg/kg for 2 days at single daily doses). The day after administration, hearts were excised and examined histopathologically, immunohistochemically and electron microscopically. Degeneration and necrosis of myocardial cells with vacuolation were observed in rats administered COL at 1.25 mg/kg or VCR at 0.75 mg/kg. Electron microscopic examination revealed vacuoles in swollen mitochondria. Moreover, there were cells showing pyknosis and karyorrhexis in the interstitium. TUNEL and immunohistochemical staining for endothelial cells and electron microscopic examination identified the apoptotic cells in the interstitium to be vascular endothelial cells. These vascular endothelial lesions were induced by lower doses of MDAs than were myocardial lesions. Furthermore, common sites of cardiac lesions induced by MDAs had almost the same distribution as areas positive for pimonidazole, a marker of hypoxia. These findings indicate that MDAs occasionally damage mitochondria in myocardial cells, and suggest that these changes involve microcirculatory dysfunction induced by endothelial cell injury.  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