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   2801篇
  免费   134篇
  国内免费   11篇
耳鼻咽喉   13篇
儿科学   52篇
妇产科学   17篇
基础医学   316篇
口腔科学   122篇
临床医学   160篇
内科学   617篇
皮肤病学   80篇
神经病学   182篇
特种医学   209篇
外科学   469篇
综合类   21篇
预防医学   175篇
眼科学   63篇
药学   197篇
中国医学   1篇
肿瘤学   252篇
  2022年   29篇
  2021年   52篇
  2020年   32篇
  2019年   38篇
  2018年   55篇
  2017年   42篇
  2016年   36篇
  2015年   46篇
  2014年   55篇
  2013年   67篇
  2012年   129篇
  2011年   131篇
  2010年   77篇
  2009年   52篇
  2008年   127篇
  2007年   127篇
  2006年   109篇
  2005年   127篇
  2004年   118篇
  2003年   106篇
  2002年   105篇
  2001年   82篇
  2000年   88篇
  1999年   88篇
  1998年   26篇
  1997年   23篇
  1996年   22篇
  1995年   24篇
  1994年   14篇
  1993年   15篇
  1992年   57篇
  1991年   54篇
  1990年   52篇
  1989年   81篇
  1988年   91篇
  1987年   55篇
  1986年   55篇
  1985年   66篇
  1984年   36篇
  1983年   43篇
  1982年   22篇
  1981年   15篇
  1980年   14篇
  1979年   38篇
  1974年   20篇
  1972年   22篇
  1971年   26篇
  1969年   22篇
  1968年   23篇
  1966年   15篇
排序方式: 共有2946条查询结果,搜索用时 15 毫秒
941.
A 62-year-old man was admitted to our hospital for dysphagia, leukocytosis, and pyrexia. The serum level of granulocyte colony-stimulating factor (G-CSF) was high and immunostaining of a biopsy specimen of esophageal tumor using anti-granulocyte-macrophage colony-stimulating factor (anti-GM-CSF) antibody demonstrated GM-CSF expression in the cytoplasm of the tumor cells. After esophagectomy, the leukocyte count and serum G-CSF level normalized. Histologically, this tumor was diagnosed as a carcinosarcoma with two components: squamous cell carcinoma and sarcoma. Tumor cells were also positive for G-CSF receptor, suggesting autocrine growth regulation by G-CSF. Moreover, tumor cells were positive for Ki-67, cyclin D1, p53, and epidermal growth factor receptor (EGFR), which were related to the acquisition of more aggressive tumor behavior. Although G-CSF-producing esophageal carcinosarcoma is very rare, we should consider such disease when a patient has symptoms of leukemia such as leukocytosis and high fever.  相似文献   
942.

Background

Use of an endocytoscopy system (ECS) makes it possible to omit biopsy histology for esophageal squamous cell carcinoma (ESCC). However, for differential diagnosis of ESCC, the endocytoscopic characteristics of esophagitis should be clarified.

Methods

We examined the morphology of surface cells in 20 cases of gastroesophageal reflux disease (GERD) (Grade M: 6 cases, A: 5 cases, B: 1 cases, C: 4 cases, D: 4 cases), five cases of candida esophagitis, and one case of eosinophilic esophagitis. One endoscopist classified the lesions using the modified type classification, and one pathologist judged the endocytoscopy images as “neoplastic”, “borderline”, or “non-neoplastic”.

Results

All cases of Grade M, A, and B GERD were classified as “type 1 or 2” by the endoscopist. However, 3/8 Grade C and D GERD lesions that had been diagnosed as regenerative squamous epithelium from biopsy histology were diagnosed as Type 3. All Grade M, A, and B cases were interpreted by the pathologist as “non-neoplastic”, whereas 4/8 Grade C and D GERD lesions, including three cases of regenerating epithelium, were diagnosed as “borderline” on the basis of ECS images. In 80 % of candida esophagitis cases, hyphae were visualized as white areas. Eosinophilic esophagitis showed a slight increase of cell density with marked infiltration of inflammatory cells.

Conclusion

Some cases of severe GERD cannot be clearly distinguished from esophageal squamous cell carcinoma (ESCC) using ECS, and therefore at present, cases of ESCC coexisting with severe GERD should not be diagnosed by ECS alone and probably require biopsy. (UMIN000007627).
  相似文献   
943.
Granulocyte colony-stimulating factor (G-CSF) induces the mobilization of leukocytes from the bone marrow (BM) to the circulation by a yet incompletely understood mechanism. Here, we describe that the membrane-bound receptor LR11 is highly expressed in human myeloid cells and that the shed soluble form of LR11 (sLR11) is a modifier of myeloid cell migration. In the process of leukocyte mobilization by G-CSF treatment, circulating sLR11 levels are transiently elevated in humans and mice. Moreover, following G-CSF treatment, the sLR11 levels in patients show significant positive correlation with the numbers of mobilized leukocytes. The changes of LR11 levels in BM cells and of sLR11 released into the BM fluid of mice correlate tightly with the changes in circulating sLR11 levels. G-CSF dose-dependently enhanced sLR11 release from HL-60 cells, which in turn accelerated cell migration. Finally, cooperatively with tumor necrosis factor-α (TNF-α) and G-CSF, sLR11 increased the attachment of floating cells (HL-60 and U937) to endothelial cells. We propose that sLR11 is a novel candidate modifier of G-CSF-mediated mobilization of hematologic cells. Identification of sLR11 as a regulatory component of G-CSF-mediated hematologic cell mobilization may facilitate further improvement of hematologic stem cell collection for clinical applications.  相似文献   
944.
A 78-year-old man with a history of neurofibromatosis was transferred to our hospital for treatment of an abdominal aortic aneurysm. T The patient was treated by stent graft implantation and was discharged from the hospital without complications. After discharge, the patient reported repeated episodes of abdominal pain. Computed tomography performed 3 months postoperatively showed localized lymphadenopathy along the graft with extravasation of contrast, suggesting the diagnosis of rupture of the aortic aneurysm. Emergent laparotomy was performed, which showed penetration of the graft through the aortic wall due to deformation of the aorta caused by lymphadenopathy. The lymphadenopathy resolved after removal of the graft. This is the first reported case of stent graft failure due to aortic deformation associated with neurofibromatosis.  相似文献   
945.

Purpose  

We investigated the usefulness of preoperative fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) as a tool for predicting recurrence patterns to select patients for liver resection as an initial surgical strategy for hepatocellular carcinoma.  相似文献   
946.
947.
AimThe purpose of this work is to investigate the effects of simvastatin on sciatic nerve regeneration in male Wistar Rats.Materials and methodsForty animals were allocated into four groups: (1) control (C); (2) control + simvastatin (CS); (3) lesioned animals + sterile PBS (LC) and (4) lesioned animals + simvastatin (LS). Lesioned animals were submitted to crushing lesion of right sciatic nerve. Simvastatin (20 mg/kg/day, i.p.) was administered for five days. Footprints were obtained weekly for evaluation of functional locomotor recovery by means of the Sciatic Function Index (SFI). Blood samples were obtained weekly for quantifying circulating leukocytes. Animals were sacrificed after 21 days for histological analyses of sciatic nerve and spleen.ResultsLS Animals presented increased SFI scores, decreased areas of oedema and mononuclear cell infiltration during Wallerian degeneration and nerve regeneration (7,14 and 21 days; P < 0.05). Spleen weight and white pulp areas was increased in LC animals after 21 days. Increased numbers of circulating neutrophils were observed in simvastatin treated animals (CS e LS) at seven, 14 and 21 days, compared to non-treated groups (C and LC).ConclusionThe study suggests that simvastatin accelerates the morphological and functional recovery process of the peripheral nervous system interfering with innate and acquired immunity.  相似文献   
948.
An 83-year-old man with a decreasing level of consciousness was carried to the emergency room. Computed tomography (CT) revealed a ruptured aortic arch aneurysm. He was deemed a high risk candidate for conventional surgical repair. The case was treated by a hybrid approach. Endo-exclusion of thoracic aortic aneurysm (TAA) was obtained by implanting stentgrafts from the ascending to descending aorta. The brain circulation was maintained by right to left carotid and to left subcravian artery bypasses combined with" chimney endo-debranching graft" of the innominate artery. This could be a method of choice for the acute patients under similar circumstances.  相似文献   
949.
Subarachnoid hemorrhage (SAH) with intraventricular hemorrhage (IVH) is associated with poor outcomes. The aim of this study was to evaluate the safety and feasibility of combined coiling and neuroendoscopy for treating severe SAH with massive IVH. Between April 2008 and June 2011, 49 patients with a severe SAH were treated at the Department of Neurosurgery, Fukuoka University, Japan; 10 of these patients had a massive IVH with a ruptured aneurysm. All 10 patients (three men and seven women; mean age, 63.1 ± 8.5 years) were treated with coiling and neuroendoscopic removal of the IVH within 2 days of onset. Coiling was successfully performed at a mean volume embolization ratio of 21.8 ± 5.5%. Neuroendoscopic removal of the IVH reduced the mean Graeb score from 10.5 ± 2.0 to 4.8 ± 2.5 (p = 0.005). All external drains were removed on day 3. No rebleeding or acute hydrocephalus was noted. The Glasgow Outcome Scale scores at discharge indicated two patients with good recovery, three with moderate disability, four in a vegetative state, and one dead. A good modified Rankin Scale (mRS) score (0–2) at least 6 months later (mean follow-up period, 15.4 ± 9.2 months) was observed for five patients (50%), and a poor mRS score (3–6) was observed for the remaining four patients. Neuroendoscopically removing the IVH from all of the ventricles between the lateral and the fourth ventricle and coiling the ruptured aneurysm is a safe, feasible approach for treating severe SAH with massive IVH.  相似文献   
950.
Since recent studies have demonstrated that penetration profiles of fluoride into plaque falls from the saliva plaque interface towards the enamel, it was hypothesized that charged components may restrict the inward diffusion of fluoride i.e., protonated fluoride and may penetrate more effectively than fluoride ion. Therefore, in this study, we investigated the effects of pH on fluoride uptake and distribution in natural undisturbed human plaque formed in vivo by means of the Leeds in situ device. At pH 3 significantly less fluoride was present throughout the plaque layer compared with pH 7. Similar profiles were seen in the plaque produced over 1 week and 3 weeks. These results may be due to binding to components of the plaque matrix via hydrogen bonding. Protonation of bacterial cell surfaces may also lead to binding of the ionized portion of fluoride. In conclusion, low pH affected the short-term fluoride uptake from a 1,000 ppm fluoride solution.  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