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   6390篇
  免费   346篇
  国内免费   21篇
耳鼻咽喉   60篇
儿科学   222篇
妇产科学   61篇
基础医学   1115篇
口腔科学   281篇
临床医学   535篇
内科学   950篇
皮肤病学   237篇
神经病学   702篇
特种医学   264篇
外科学   804篇
综合类   35篇
一般理论   2篇
预防医学   247篇
眼科学   288篇
药学   465篇
中国医学   9篇
肿瘤学   480篇
  2023年   18篇
  2022年   50篇
  2021年   89篇
  2020年   83篇
  2019年   67篇
  2018年   105篇
  2017年   96篇
  2016年   131篇
  2015年   175篇
  2014年   188篇
  2013年   239篇
  2012年   366篇
  2011年   366篇
  2010年   253篇
  2009年   253篇
  2008年   463篇
  2007年   395篇
  2006年   410篇
  2005年   410篇
  2004年   458篇
  2003年   411篇
  2002年   377篇
  2001年   101篇
  2000年   86篇
  1999年   95篇
  1998年   97篇
  1997年   92篇
  1996年   70篇
  1995年   50篇
  1994年   41篇
  1993年   43篇
  1992年   35篇
  1991年   30篇
  1990年   30篇
  1989年   50篇
  1988年   34篇
  1987年   28篇
  1986年   23篇
  1985年   26篇
  1984年   17篇
  1983年   15篇
  1982年   23篇
  1981年   15篇
  1980年   16篇
  1979年   15篇
  1978年   15篇
  1977年   18篇
  1974年   13篇
  1973年   16篇
  1972年   18篇
排序方式: 共有6757条查询结果,搜索用时 15 毫秒
51.
52.
53.
Clinical and ecological evidence supporting an association between human papillomavirus (HPV)‐related tumors and dietary factors are presented. Abstinence from high intake of fried pork (600–1,000 g/day) was associated with regression of an urethral condyloma in a healthy 19‐year‐old man treated with interferon gamma. International correlations suggest that pork intake is positively associated with incidence of cervical cancer, a disease also related to HPV. Pork meat or dietary factors associated with pork meat consumption may be involved in the development of HPV‐related diseases.  相似文献   
54.
55.
BACKGROUND: Anti-CD3 immunotoxins are broad-spectrum immunosuppressive agents in a wide range of organ transplantation animal models with potential use in eliciting antigen-specific tolerance. However, the anti-CD3 immunotoxins used in animal studies do not cross-react with human T cells, limiting extrapolation to humans and hindering clinical development. METHODS: Three anti-human CD3-directed immunotoxins, DT389-scFv(UCHT1), scFv(UCHT1)-PE38, and UCHT1-CRM9, were compared in vitro and in transgenic mice, tg(epsilon)600+/-, that have T cells expressing both human and murine CD3epsilon antigens. RESULTS: These immunotoxins were extraordinarily potent in vitro against human or transgenic mouse T cells, with IC50 values in cellular assays ranging from pM to fM. Systemic administration of these immunotoxins dose-dependently depleted >99% of tg(epsilon)600+/- lymph node and spleen T cells in vivo. Depletion was specific for T cells. The loss of the concanavalin A-induced, but not the lipopolysaccharide-induced, splenic proliferative response from immunotoxin-treated animals further demonstrated specific loss of T-cell function. Immunotoxin treatment prolonged fully allogeneic skin graft survival in tg(epsilon)600+/- recipients to 25 days from 10 days in untreated animals. T-cells recovered to approximately 50% of normal levels after approximately 22 days in animals with or without skin grafts; T-cell recovery correlated with skin graft rejection. All three immunotoxins elicited >100 day median survival of fully allogeneic heterotopic heart grafts. By 100 days, T cells recovered to normal numbers in these animals, but the grafts showed chronic rejection. CONCLUSION: These immunotoxins profoundly deplete T cells in vivo and effectively prolong allogeneic graft survival.  相似文献   
56.
BACKGROUND AND PURPOSE: Unilateral total adrenalectomy is the standard treatment for benign unilateral adrenal tumors. Partial adrenalectomy has to be considered for bilateral adrenal tumors. Recently, our group has reported the feasibility of unilateral and bilateral partial adrenalectomy by means of laparoscopy. Now, we present a case of recurrent pheochromocytoma after open bilateral adrenalectomy and demonstrate that laparoscopic cortex-sparing surgery is feasible for a recurrence after open surgery. Case Report: At the age of 10 years, a boy was found to have bilateral adrenal pheochromocytoma and was treated by open bilateral partial adrenalectomy. Eight years later, the patient presented with palpitation, sweating, and severe hypertension. Investigations biochemically and radiologically demonstrated functional recurrent pheochromocytoma in the left adrenal gland. Genetic studies confirmed mutation of the von Hippel-Lindau (VHL) gene. The patient was prepared for surgery preoperatively by phenoxybenzamine and metropolol. The surgery was performed as planned, and the normal adrenal tissue was spared. The patient had an uneventful postoperative course. His blood pressure was normal on the day of discharge. CONCLUSIONS: In a specialized center with experienced laparoscopic surgeons, laparoscopic partial adrenalectomy for recurrent pheochromocytoma is feasible even after previous open surgery on the ipsilateral adrenal gland. Adrenal-sparing surgery is indicated in hereditary syndromes such as VHL and MEN II to avoid the problems of life-long steroid replacement. Recurrences have to be expected, but further surgery may be less difficult by the previous laparoscopic approach.  相似文献   
57.
Objective Ulnar shortening to unload the ulnocarpal ligamentous complex. Indications Clinically relevant ulnar impaction syndrome, be it congenital or posttraumatic. Contraindications Concomitant pronounced malunion of the radius.Osteoarthritis of the distal radioulnar joint. Surgical Technique Ulnopalmar approach. Oblique osteotomy of the ulna in its distal third. Removal of a bony wafer of predetermined thickness. Internal fixation with a 7-hole LD-DC plate or special plate and lag screw. Results 29 patients (14 men, 15 women, average age 42 years) underwent an ulnar shortening osteotomy for a therapy-resistant ulnar impaction syndrome.Follow-up after an average of 25 (7–37) months. Average amount of shortening 4.5 (1.5–13) mm. 72% reduction of pain as determined with a visual analog scale. The range of motion was improved by 7% in extension/flexion, by 8% in abduction/adduction and by 11% in pronation/supination. Grip strength measured with a vigorimeter (balloon size 5) increased by 12%.Complications: three malunions, effectively treated by revision of internal fixation.  相似文献   
58.
Introduction Postoperative treatment for colorectal cancer depends on tumor stage as defined by the International Union Against Cancer (UICC). Adjuvant chemotherapy is not recommended in patients without lymph node involvement (UICC stages I and II). As many as 20–30% of these patients, however, will develop recurrence. Aims and objectives We conducted this study to determine the presence of disseminated tumor cells in the lymph nodes by quantitative real-time polymerase chain reaction (QRT-PCR) for cytokeratin 20 (CK20) in an attempt to provide supplementary information compared to histopathological findings. Materials and methods Using a standard QRT-PCR assay, we examined primary tumors and 391 lymph nodes from 31 patients with completely resected colorectal cancer. Results Of the 31 primary tumors, 29 were positive for CK20 by QRT-PCR. Discussion An examination of the lymph nodes from the 29 patients with CK20-positive primary tumors revealed that 35 (92.1% sensitivity) of the 38 histopathologically positive lymph nodes and 54 (16.7%) of the 324 histopathologically negative lymph nodes were positive by molecular analysis. CK20 expression was detected in 10 (100%) of 10 patients with a histopathologically positive lymph node status (pN1). In 9 (47.4%) of 19 patients with negative histopathological results (pN0), we detected a CK20 mRNA signal in at least one lymph node. Whereas eight patients with histopathologically negative lymph nodes could be upstaged on the basis of the molecular findings, no patient would be downstaged. Conclusion Our results suggest that QRT-PCR for CK20 is a useful tool for the quantitative detection of micrometastases in the regional lymph nodes. We introduce a standardized procedure that integrates a molecular diagnostic technique in the clinical staging.  相似文献   
59.
Peptic ulcer in the excluded segment of a gastric bypass has been reported in the literature in only 17 cases.We report a 54-year-old woman with a perforated duodenal ulcer, who had undergone laparoscopic Roux-en-Y gastric bypass surgery for morbid obesity 15 months previously. She was successfully treated by a laparoscopic repair of the perforated duodenal ulcer.  相似文献   
60.
Metal-on-metal hip resurfacing has become a widespread procedure, especially in young, physically active patients. Pseudotumor is a new complication that can occur after hip resurfacing and metal-on-metal total hip arthroplasty (THA). This article presents a case of a 37-year-old woman who underwent metal-on-metal resurfacing of the left hip for symptomatic osteoarthritis. Twelve months following implantation, the patient reported painless swelling of the left lower leg. There was no clinical evidence of a deep venous thrombosis. Ultrasound and computed tomography showed a solid cystic lesion in the iliopsoas muscle, which communicated with the hip joint and compressed the external iliac vein. As a consequence, the cystic lesion was resected marginally. A few months later, the patient reported some discomfort in the groin and symptoms of instability, metallic clicking, and a restricted range of motion. Clinical and radiological examination revealed normal findings. Determining the serum concentration of cobalt and chromium revealed high increased levels of these metal ions. Ten months following excision of the pseudotumor, the patient reported recurrent swelling of the left lower leg. Computed tomography of the affected area showed a lobulated cystic formation; therefore, a relapse was suspected. At the second revision, the mass was excised and the implant was revised to a conventional ceramic-on-ceramic THA. At 30-month follow-up, the patient was doing well and there were no signs of local recurrence. Additionally, the metal ion levels of cobalt and chromium in the blood had significantly decreased.  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