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   2786篇
  免费   128篇
  国内免费   16篇
耳鼻咽喉   12篇
儿科学   64篇
妇产科学   11篇
基础医学   380篇
口腔科学   60篇
临床医学   163篇
内科学   586篇
皮肤病学   136篇
神经病学   160篇
特种医学   60篇
外科学   572篇
综合类   20篇
预防医学   54篇
眼科学   145篇
药学   133篇
中国医学   3篇
肿瘤学   371篇
  2024年   1篇
  2023年   26篇
  2022年   55篇
  2021年   79篇
  2020年   32篇
  2019年   55篇
  2018年   57篇
  2017年   50篇
  2016年   60篇
  2015年   61篇
  2014年   108篇
  2013年   146篇
  2012年   188篇
  2011年   188篇
  2010年   109篇
  2009年   92篇
  2008年   146篇
  2007年   154篇
  2006年   180篇
  2005年   176篇
  2004年   219篇
  2003年   168篇
  2002年   192篇
  2001年   26篇
  2000年   30篇
  1999年   37篇
  1998年   43篇
  1997年   32篇
  1996年   28篇
  1995年   37篇
  1994年   33篇
  1993年   20篇
  1992年   20篇
  1991年   16篇
  1990年   8篇
  1989年   8篇
  1988年   6篇
  1987年   8篇
  1986年   7篇
  1985年   1篇
  1984年   5篇
  1983年   6篇
  1982年   4篇
  1981年   5篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1975年   2篇
  1967年   1篇
排序方式: 共有2930条查询结果,搜索用时 31 毫秒
71.
72.
A 20-year-old man with Duchenne muscular dystrophy (DMD) with recurrent gastric volvulus underwent percutaneous endoscopic gastrostomy (PEG). Four months later, he developed vomiting and consciousness disturbance. CT revealed gastric volvulus recurrence along the gastrostomy axis. Endoscopic repositioning failed and fistula perforation necessitated emergency surgery. The upper position of the stomach was twisted counter-clockwise and revolved on the gastrostomy axis sliding between the lower stomach and abdominal wall. The fistula showed necrotic perforation and was thus resected. The anterior stomach wall was fixed to the abdominal wall at 3 triangular points. Thereafter, gastric volvulus did not recur. PEG is reportedly effective for preventing gastric volvulus, but there are rare cases of postgastrostomy recurrence. This successfully managed case provides valuable clinical insights.  相似文献   
73.
Computed tomography colonography (CTC) was performed in 5 patients with pneumatosis cystoides intestinalis (PCI). The virtual colonoscopy view of CTC as well as total colonoscopy (TCS) findings showed polypoid lesions in the colon, and multiplanar reconstruction images of the colon revealed in the polypoid lesions of the colon. We confirmed the diagnosis of PCI in all cases. CTC also detected the PCI lesions in the subserosa of the colonic wall which were not detected by TCS. Accurate evaluation of the extent of PCI involvement was obtained by CT air-contrast enema images. CTC is useful for detection of PCI lesions, assessment of the exact site and final diagnosis for PCI.  相似文献   
74.
75.
Xanthomatous meningioma is an extremely rare variant of meningioma that is characterized histopathologically by the presence of tumor cells with lipid-filled vacuolated cytoplasm. In this report, we describe the fifth documented case of xanthomatous meningioma and review its clinicopathological features. A 76-year-old Japanese male presented with dizziness. Magnetic resonance imaging demonstrated a well-circumscribed tumor in the left parasagittal to frontal region with attachment of the dura mater. Histopathological examination of the resected specimen revealed proliferation of polygonal to spindle cells with eosinophilic cytoplasm and bland round to oval nuclei. Whorl formation and psammomas were scattered, and mitotic figures were rarely seen. A peculiar finding was the presence of extensive xanthomatous change continuing to the above-mentioned typical meningothelial meningioma. These tumor cells had clear vacuolated cytoplasm and bland round to oval nuclei. Immunohistochemically, xanthomatous cells were positive for epithelial membrane antigen. Accordingly, an ultimate diagnosis of xanthomatous meningioma was made. Our clinicopathological analysis revealed that xanthomatous meningioma affects children to young persons or the elderly, and four of five cases were located in the supratentorial region. Although the detailed mechanism underlying the xanthomatous change has not been clarified, this change is thought to result from a metabolic abnormality of the neoplastic meningothelial cells. Further, xanthomatous change has also been reported in atypical and anaplastic meningiomas. Therefore, it is important to recognize that xanthomatous change can occur in meningiomas, and to avoid misidentifying these cells as macrophages.  相似文献   
76.
Follicular mucinosis is recognized as one of the histopathological reaction patterns characterized by the accumulation of mucin within follicular epithelium. It is induced by various causes including inflammatory diseases, and more than half of the cases are associated with malignant lymphoma, mainly mycosis fungoides. Herein, we describe the third documented case of adult T-cell leukemia/lymphoma (ATLL) accompanying follicular mucinosis. A 72-year-old Japanese male presented with persistent erythema in his arm and neck. Laboratory tests demonstrated positivity for human T-cell leukemia virus (HTLV)-1 antibodies. Histopathological study of the biopsy specimen from the neck revealed superficial perivascular, nodular, and intrafollicular lymphocytic infiltrations. These lymphocytes were small- to medium-sized and had convoluted nuclei. Mucoid material deposition was observed within the hair follicles, and it was digested by hyaluronidase. Immunohistochemically, these lymphocytes were positive for CD3, CD4, CD25, and Foxp3. Accordingly, an ultimate diagnosis of ATLL accompanying follicular mucinosis was made. The skin is the most common extralymphatic site of involvement of ATLL. The present case clearly demonstrated that albeit extremely rare, ATLL can cause follicular mucinosis. Therefore, ATLL should be included in the differential diagnostic consideration of follicular mucinosis.  相似文献   
77.
78.
79.

Background

We aimed to identify a noninvasive predictor of portal venous pressure (PVP).

Methods

We directly measured the PVP in 40 consecutive patients who underwent direct percutaneous transhepatic portal vein puncture as part of the therapeutic management for liver diseases, and we evaluated the association of the PVP with noninvasive clinical parameters. The backgrounds of the liver were normal in 13 patients, chronic hepatitis in 17, and liver cirrhosis in ten.

Results

The mean PVP was 202 ± 114 mmH2O. In a multivariate linear regression analysis, the serum bile acid level and splenic volume showed independent positive correlations with the PVP (P < 0.001 and 0.002, respectively). The formula for estimating PVP was identified as follows: PVP (mmH2O) = serum bile acid (??mol/L) × 2.593 + splenic volume (cm3) × 0.416 + 65.929 (R 2 = 0.698). In a receiver operating characteristic (ROC) analysis, the AUC values of serum bile acid and splenic volume at a PVP of 200 mmH2O were 0.909 and 0.758, respectively. However, the AUC values of serum bile acid and splenic volume at a PVP of 250 mmH2O were 0.792 and 0.926, respectively, suggesting that the serum bile acid level and splenic volume are sensitive predictors of early and advanced portal hypertension, respectively.

Conclusions

Combined measurements of the serum bile acid level and splenic volume may be useful to noninvasively assess the PVP prior to further invasive procedures.  相似文献   
80.
Background and Aim: Type 1 autoimmune pancreatitis (AIP) is characterized by the increase of serum immunoglobulin (Ig)G4 and abundant IgG4 plasma cell infiltration in the pancreas and various extrapancreatic lesions (EPL), which are proposed as IgG4‐related disease. We assessed the correlation between serum IgG4 and the number of EPL, and the association between serum IgG4 and the distribution of EPL in type 1 AIP patients. Methods: Serum IgG4 was measured in 35 type 1 AIP patients and 71 non‐AIP patients. The clinical characteristics and distribution of eight EPL were determined in 35 type 1 AIP patients. Results: Serum IgG4 in type 1 AIP was significantly higher than in non‐AIP (P < 0.001). A total of 33 patients had EPL among 35 patients with type 1 AIP (94.3%). There was a significant correlation between serum IgG4 and the number of EPL (ρ = 0.75, P < 0.001). Further, to assess the association between serum IgG4 and the distribution of EPL, type 1 AIP patients were divided into two groups: as abdominal localized EPL and systemic EPL. Both serum IgG4 and total numbers of EPL in systemic EPL were remarkably higher than those in abdominal localized EPL. Serum IgG4 cut‐off value was 346 mg/dL to distinguish between abdominal localized EPL and systemic EPL according to the receiver–operator characteristic curve data. Conclusions: Our findings indicated that serum IgG4 was useful in both the diagnosis of type 1 AIP and the detection of systemic EPL. Our finding may help the concept and diagnostic criteria of IgG4‐related disease with type 1 AIP.  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