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   696篇
  免费   16篇
耳鼻咽喉   5篇
儿科学   48篇
妇产科学   17篇
基础医学   76篇
口腔科学   10篇
临床医学   80篇
内科学   147篇
皮肤病学   23篇
神经病学   37篇
外科学   137篇
综合类   9篇
预防医学   16篇
眼科学   3篇
药学   48篇
中国医学   3篇
肿瘤学   53篇
  2022年   10篇
  2021年   9篇
  2017年   3篇
  2016年   3篇
  2015年   12篇
  2014年   12篇
  2013年   10篇
  2012年   10篇
  2011年   4篇
  2010年   14篇
  2009年   21篇
  2008年   9篇
  2007年   7篇
  2006年   36篇
  2005年   25篇
  2004年   20篇
  2003年   15篇
  2002年   11篇
  2001年   10篇
  2000年   5篇
  1999年   13篇
  1998年   36篇
  1997年   39篇
  1996年   29篇
  1995年   39篇
  1994年   29篇
  1993年   21篇
  1992年   16篇
  1991年   14篇
  1990年   3篇
  1989年   11篇
  1988年   7篇
  1987年   3篇
  1986年   9篇
  1985年   8篇
  1984年   9篇
  1982年   2篇
  1981年   5篇
  1980年   3篇
  1979年   3篇
  1978年   2篇
  1977年   4篇
  1976年   3篇
  1959年   7篇
  1958年   21篇
  1957年   30篇
  1956年   38篇
  1955年   30篇
  1954年   22篇
  1948年   4篇
排序方式: 共有712条查询结果,搜索用时 15 毫秒
11.
BACKGROUND: The present study was conducted to investigate how patients with clinically localized prostate cancer were treated in the Hokuriku District, Japan. METHODS: Medical records of 536 patients with stage B prostate cancer were retrospectively reviewed. The patients were diagnosed and treated at four university hospitals and 32 collaborating hospitals in the Hokuriku District. RESULTS: Because their medical records were incomplete and/or they not available for follow up, 79 cases were excluded from this study. Conservative treatment with hormone therapy was used for 248 cases. Radical prostatectomy was performed in 199 cases, only 27 of whom underwent surgical monotherapy. There was no significant difference in disease-specific survival rates between the hormone (69.0%) and surgery group (83.2%) after 110 months. Results of the analysis of disease-specific survival rates according to histologic grade showed that patients with poorly differentiated cancers treated with hormone therapy were the only subset with significant differences when compared against the other patients. CONCLUSION: The value of prostatectomy alone or added was marginal in terms of survival. Only patients with poorly differentiated cancer might benefit from prostatectomy.  相似文献   
12.
Malignant transformation of renal angiomyolipoma   总被引:8,自引:0,他引:8  
In the present paper, two cases of malignant transformation of renal angiomyolipoma without tuberous sclerosis are reported. Pathological examination revealed that, in both cases, in addition to the areas affected by typical angiomyolipoma, there were areas that contained elevated numbers of perivascular epithelioid cells with prominent nuclear pleomorphism. Immunohistochemical examination revealed that both cases were negative for keratin and epithelial membrane antigen, but were positive for the melanogenesis-related marker HMB-45. Metastatic diseases appeared 40 months after radical nephrectomy in the first case and 18 months in the second case.  相似文献   
13.
Efficacy and safety of laparoscopic surgery for pheochromocytoma   总被引:4,自引:0,他引:4  
OBJECTIVE: Laparoscopic surgery for primary aldosteronoma and Cushing's syndrome is well established. We report on our experiences with laparoscopic adrenalectomy for pheochromocytoma, and assess the efficacy and safety of the laparoscopic approach. METHODS: Between April 1998 and April 2003, a total of 23 patients underwent laparoscopic adrenalectomy for pheochromocytoma at Chiba University Hospital and Yokohama Rosai Hospital, Japan. We compared the surgical outcomes of these patients with those of 106 patients with adrenal tumors due to other pathologies who underwent laparoscopic adrenalectomy during the same period. RESULTS: The mean tumor size of pheochromocytoma was 4.96 cm. Mean operative time was 192.7 min, and mean estimated blood loss was 130 mL. Neither mean operative time nor mean estimated blood loss was greater for patients with pheochromocytoma. Intraoperative hypertension (systolic blood pressure > 180 mmHg) occurred in 39.1% (9/23) of patients with pheochromocytoma. During the follow-up period, there were no mortalities or recurrences of endocrinopathy. CONCLUSIONS: Laparoscopic adrenalectomy for pheochromocytoma is a safe and minimally invasive procedure.  相似文献   
14.
Summary In normal human skin, immtmoreactive thrombomodulin (TM) is expressed in a strict differentiation related pattern. solely in suprabasal spinous layer keratinocytes. To evaluate the polential application of TM as a differentiation marker for keratinocyte-derived skin tumours, we have studied immunohistopathological, biochemical and functional TM activities in various skin tumours. Immunoreactive, full sized and enzymatically active TM was expressed in keratinocyte-derived skin tumours (squamous cell carcinoma, seborrhoeic keratosis and partly Bowen's disease), as well as normal epidermal keratinoeytes and endothelial cells. However, no TM was detected in basal cell carcinotnas, senile keratosis or non-squanious epithelial tumours such as malignant melanoma, naevus pigmentosus and Paget's disease. Interestingly, decreased expression was observed in verruca vulgaris. These findings suggested that differentiation-dependent TM expression was restricted to epithelial skin tumours and undetectable on neural crest derived tumours. TM is a differentiation marker for spinous layer keratinocytes and is a useful tool in histopathological study of epithelial tumours.  相似文献   
15.
Monoclonal antibodies against human Cu,Zn-superoxide dismutase (SOD) and Mn-SOD were used to stain frozen sections of normal and abnormal human skin. In normal human epidermis, the Cu,Zn-SOD antibody almost exclusively stained the basal cells. Mn-SOD antibody weakly stained the whole of the epidermis but more predominantly the basal cell layer. In psoriasis, Cu,Zn-SOD antibody mainly stained the basal cells of the lowest parts of the elongated rete ridges. Basal cells corresponding to the tip of the dermal papillae were weakly stained. Mn-SOD staining was considerably decreased in the psoriatic epidermis. In squamous cell carcinoma, staining with both Cu,Zn-SOD and Mn-SOD antibodies was decreased, and single cells positive for Cu,Zn-SOD were scattered throughout the tumour nests. In basal cell epithelioma, Cu,Zn-SOD staining was intense and diffusely distributed throughout the tumour nests, while Mn-SOD staining was absent.  相似文献   
16.
17.
Summary. Background: C4b‐binding protein (C4BP), a multimeric protein structurally composed of α chains (C4BPα) and a β chain (C4BPβ), regulates the anticoagulant activity of protein S (PS). Patients with sepsis have increased levels of plasma C4BP, which appears to be induced by interleukin (IL)‐6. However, it is not fully understood how lipopolysaccharide (LPS) and IL‐6 affect the plasma C4BP antigen level and C4BPα and C4BPβ expression in hepatocytes. Objectives: To assess the effect of LPS and IL‐6 on plasma C4BP, PS–C4BP complex levels, PS activity, and C4BP expression by rat liver in vivo and on C4BP expression by isolated rat hepatocytes in vitro. Results: Plasma C4BP antigen level transiently decreased from 2 to 12 h after LPS (2 mg kg?1) injection, and then it abruptly increased up to 24 h after LPS injection. Plasma C4BP antigen level increased until 8 h after IL‐6 (10 μg kg?1) injection, and then gradually decreased up to 24 h after IL‐6 injection. LPS significantly decreased the protein and mRNA expression of both C4BPα and C4BPβ in rat hepatocytes, and this effect was inhibited by NFκB and MEK/ERK inhibitors. IL‐6 mediated increase in C4BPβ expression in rat hepatocytes, which leads to increased plasma PS–C4BP complex level and to decreased plasma PS activity, was inhibited by inhibition of STAT‐3. Conclusion: LPS decreases both C4BPα and C4BPβ expression via the NFκB and MEK/ERK pathways, whereas IL‐6 specifically increases C4BPβ expression via the STAT‐3 pathway, causing an increase in plasma PS–C4BP complex, and thus decreasing the anticoagulant activity of PS.  相似文献   
18.
To clarify the validity of positron emission tomography using fluoro-2-deoxyglucose (FDG-PET) for the preoperative evaluation of endometrial cancer, we analyzed the preoperative FDG-PET images of both primary and metastatic lesions of 30 patients with endometrial cancer, and compared them with computed tomography (CT) and/or magnetic resonance imaging (MRI) images and the results of postoperative pathologic findings. As to the primary lesions, FDG-PET could easily identify the cancer, and the sensitivity was 96.7%, which tended to be higher than that of 83.3% by CT/MRI. As to the evaluation of retroperitoneal lymph node metastasis, FDG-PET could detect none of five cases of lymph node metastatic lesions of up to 0.6 cm in diameter but had higher specificity (100%) compared with CT/MRI (85.7%). The sensitivity of FDG-PET for detection of extrauterine lesions excluding retroperitoneal lymph nodes was 83.3% and was superior to that of CT/MRI (66.7%), although there was no difference in the specificity between the modalities (100%). The diagnostic ability of FDG-PET was limited if used alone, but FDG-PET gave additional information especially with regard to the extrauterine lesions whose significance could not be determined on CT/MRI. However, we also found that FDG-PET could not identify any lymph node metastasis less than 1 cm in diameter; therefore, a negative finding of lymph node metastasis on FDG-PET should not be interpreted as a reason for omitting retroperitoneal lymph node dissection for the precise surgical staging of endometrial cancer.  相似文献   
19.
20.
An ultrastructural study was undertaken on cartilage resorption at the site of initial endochondral bone formation in the mouse mandibular condyle on d 16 of pregnancy. After resorbing the bone collar, the osteoclasts extended their cell processes into the cartilage matrix and made contact with hypertrophic chondrocytes. By means of cell processes or vacuolar structures, these osteoclasts entrapped the calcified cartilage matrices, cell debris, and the degraded uncalcified cartilage matrices. In particular, since the calcified cartilage matrices were sometimes seen to be disrupted within the osteoclastic vacuolar structures, they were probably disposed of by the osteoclasts. Invading endothelial cells giving rise to capillaries also directly surrounded the degraded uncalcified cartilage matrices and small deposits of cell debris. In addition, hypertrophic chondrocytes that had attached to or were in the process of attaching to the invading osteoclasts often enclosed the small calcified cartilage matrices. Other cell types that have often been reported in other regions of cartilage resorption were not seen at the site of initial endochondral bone formation in this study. Our findings in relation to cartilage resorption may therefore represent unique features of the site of initial endochondral bone formation site. We consider that the manner of cartilage resorption is likely to vary by site, age, and species.  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