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   2140篇
  免费   82篇
  国内免费   13篇
耳鼻咽喉   54篇
儿科学   31篇
妇产科学   14篇
基础医学   272篇
口腔科学   67篇
临床医学   97篇
内科学   406篇
皮肤病学   96篇
神经病学   477篇
特种医学   46篇
外科学   322篇
综合类   8篇
预防医学   33篇
眼科学   43篇
药学   117篇
中国医学   15篇
肿瘤学   137篇
  2023年   10篇
  2022年   18篇
  2021年   33篇
  2020年   13篇
  2019年   17篇
  2018年   34篇
  2017年   27篇
  2016年   34篇
  2015年   29篇
  2014年   35篇
  2013年   48篇
  2012年   94篇
  2011年   87篇
  2010年   59篇
  2009年   48篇
  2008年   103篇
  2007年   88篇
  2006年   75篇
  2005年   95篇
  2004年   86篇
  2003年   83篇
  2002年   107篇
  2001年   94篇
  2000年   110篇
  1999年   80篇
  1998年   31篇
  1997年   22篇
  1996年   12篇
  1995年   23篇
  1994年   23篇
  1993年   19篇
  1992年   58篇
  1991年   63篇
  1990年   69篇
  1989年   59篇
  1988年   32篇
  1987年   50篇
  1986年   43篇
  1985年   49篇
  1984年   37篇
  1983年   28篇
  1982年   11篇
  1981年   13篇
  1980年   8篇
  1979年   9篇
  1978年   12篇
  1977年   13篇
  1973年   9篇
  1971年   4篇
  1967年   4篇
排序方式: 共有2235条查询结果,搜索用时 15 毫秒
111.
Novel magnetic resonance angiography stage grading for moyamoya disease   总被引:1,自引:0,他引:1  
BACKGROUND: Magnetic resonance angiography (MRA) has been acknowledged as a noninvasive diagnostic modality for moyamoya disease. However, in terms of staging of moyamoya disease, conventional angiography is still the gold standard. Therefore, the purpose of this study was to establish MRA grades for moyamoya disease as an alternative to conventional angiography. METHODS: Twenty-two patients (44 sides) with moyamoya disease diagnosed by conventional angiography were evaluated by MRA during the past 5 years. MRA scores were assigned based on the severity of occlusive changes of the internal carotid artery, the horizontal portion of the middle cerebral artery, the anterior and the posterior cerebral arteries and the signals of the distal branches of these arteries. Total points ranged from 0 (normal) to 10 (most severe). RESULTS: MRA scores (0-10) were significantly consistent with the conventional angiographic staging. Four grades based on this novel MRA scores correlated well with Suzuki's stages, with high sensitivity and specificity. CONCLUSIONS: These novel MRA grades can be a reliable alternative to conventional staging. By employing these novel MRA grades, the use of conventional angiography can be avoided for the purpose of evaluation of the stages of moyamoya disease.  相似文献   
112.
A 7-year-old boy, who was noted to be a slow runner at the age of 2 years, had progressive muscle weakness and atrophy, preferentially affecting distal muscles. At 3 years of age, he had scoliosis and difficulty in standing on tip-toe. Serum creatine kinase was 1074 IU/l. Muscle CT scan showed low-density areas in the lower legs and upper arms, but predominantly in the gastrocnemius and soleus muscles. Biopsy of the biceps brachii muscle showed moderate dystrophic changes with normal dysferlin expression on immunohistochemical and western blot analyses. Although muscle involvement mimicked that seen in Miyoshi myopathy (MM), the very early onset of the disease and scoliosis were quite unusual for MM. We, therefore, made the diagnosis of early onset dysferlin-positive distal muscular dystrophy, probably a new type of distal muscular dystrophy.  相似文献   
113.
We describe two cases of a malignant cutaneous neoplasm with combined phenotypical features of high-grade basal cell carcinoma and malignant melanoma. Some tumor cells showed a keratinocytic phenotype (cytokeratins, p63) and others a melanocytic phenotype (HMB-45, MART-1, Melan-A, S100-protein). We favor the hypothesis of a tumor with bidirectional keratinocytic and melanocytic differentiation, an exceptionally rare event.  相似文献   
114.
Leishmaniasis, a zoonotic protozoan disease, starts with the inoculation of the Leishmania promastigotes into the skin at the time of blood ingestion by a female sandfly. The infection of leishmaniasis is established when the Leishmania organisms start their own intracellular multiplication after having been phagocytized by the host's macrophages. In the earliest stage of the infection, therefore, the attachment of the promastigates to the macrophages is essential. We incubated a mixed culture of macrophages (JM774-1A) and Leishmania (Leishmania) major for 6 hours in vitro and observed the process of the attachment between the parasite and host cell by scanning electron microscope. We found for the first time that the attachment between the two occurred at the site of the parasite body, in addition to the previously reported sites of the flagellar tip, flagellar base, and aflagellar tip (posterior pole).  相似文献   
115.
Four cases of solitary cylindroma of the breast of skin adnexal type are described. The tumors were morphologically and immunophenotypically identical to their dermal counterparts. They arose in close proximity to the nipple, such as the retroareolar area of the breast and in intimate association with the lactiferous ducts, suggesting an origin from the latter structures. One case occurred in a woman with hereditary multiple cylindromatosis (Brooke-Spiegler syndrome). This is the second reported case of this hereditary syndrome with extracutaneous manifestations and the first case in which the breast is involved.  相似文献   
116.
Sternal shape is one of the most important esthetic factors of the chest appearance after pediatric minimally invasive cardiac surgery (pMICS) as well as length of skin wound. We evaluated the grade of postoperative sternal deformity in 20 patients who underwent total repair of pediatric congenital heart disease [atrial septal defect (ASD): 17, ventricular septal defect (VSD): 2, partial anomalous pulmonary venous connection (PAPVC): 1] with minimal skin incision and lower partial median sternotomy. The sternum was closed with stainless wire in 3 patients, with absorbable polydioxanone (PDS) cord in 5 patients, with combined use of reabsorbable radiolucent poly (L-lactate) acid sternal pin and absorbable PDS cord in 12 patients. The evaluation of postoperative sternal deformity was made according to the vertebral index (VI) and frontosagittal index (FSI) in 3 groups with each sternal closure method. VI and FSI of the 3 groups showed no significant difference. Sternal deformity in the group with sternal closure with PDS cord group was more severe than that in other 2 groups. The combined use of sternal pin with PDS cord offered the most sufficient fixative strength for sternal closure.  相似文献   
117.
We analyzed 7 patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy. Six men and a woman had a mean age of 65 years old. The postoperative mortality rate was 14% (1 death) and morbidity, 43% (3 cases). According to staging of International Mesothelioma Interest Group, 2 patients had stage I disease, 1 did stage II, 3 did stage III and 1 did stage IV. Local recurrences were found in 3 patients and metastasis in 2. In patients with local recurrences, 2 had irradiation with chemotherapy and 1, irradiation. In patients with recurrences of metastasis, 1 had chemotherapy and 1, supportive care. Seven patients with extrapleural pneumonectomy and 10 without surgery had median survivals of 16 months and 10 months, 1-year survival rates of 71% and 40% and 2-year survival rates of 57% and 0% respectively (p=0.071). Extrapleural pneumonectomy with adjuvant therapy could be effective treatment for malignant pleural mesothelioma.  相似文献   
118.
119.
The role of radiotherapy for thymic carcinoma   总被引:3,自引:0,他引:3  
OBJECTIVE: The aim of this study is to evaluate retrospectively the role of radiotherapy for thymic carcinoma. METHODS: Between 1973 and 1998, 14 patients with thymic carcinoma were treated at Gunma Prefectural Cancer Center. Two patients who had hematogenous metastasis were excluded from this study, therefore 12 patients were analyzed. The Masaoka staging system was used; four patients were diagnosed with stage III disease and eight patients with stage IV disease. The pathological subtype according to the World Health Organization histological criteria for thymic tumors was squamous cell carcinoma (low-grade histology) in six cases and undifferentiated carcinoma (high-grade histology) in six. Ten patients underwent thoracotomy, and two patients underwent excisional biopsy without thoracotomy. Ten patients (83%) received radiotherapy as a curative intent, and the median dose was 60 Gy. Systemic chemotherapy was administered to four patients (33%), and the majority (75%) of the regimens contained cisplatin. RESULTS: The 3-year overall survival rate was 25%. Histological subtype (low-grade versus high-grade), surgical resection (complete versus incomplete), radiotherapy and chemotherapy were evaluated as prognostic factors in a univariate analysis. Low-grade histology and complete resection were good prognostic factors, although these were not statistically significant. Patients who received radiotherapy had a better outcome than those who did not. The major sites of recurrence were the pleura and pericardium. Recurrence within the radiation field was observed in one of seven patients in whom failure patterns could be evaluated. CONCLUSION: Complete resection is mandatory if possible. Radiotherapy plays an important role in treating thymic carcinoma in terms of reducing local recurrence and prolonging survival time. Establishment of an innovative treatment protocol that includes chemotherapy is necessary to control intrathoracic relapse and distant metastasis.  相似文献   
120.
In the present study, we attempted to explore cell transplantation therapy for intracerebral hemorrhage (ICH) using embryonic stem (ES) cells. Collagenase-induced ICH rats were used as model animals. Mouse ES cells were differentiated into nestin-positive neural stem cells in vitro by alltrans retinoic acid (ATRA). ATRA-treated ES cells (10(5)) were transplanted into the lateral ventricle in the hemisphere contralateral to the hemorrhage 7 days after collagenase infusion. Twenty-eight days after transplantation, ES-derived neurons and astrocytes were observed around the hematoma cavities of the brain in all of the ten rats receiving grafts. Graft-derived neurons were found in the subependymal area of the lateral ventricle as cellular nodules. Although one of the ten rats receiving grafts showed uncontrolled growth of astroglia derived from the ES cells, intraventricular transplantation of ATRA-treated ES cells is an effective delivery system of neuronal lineage-committed progenitor cells toward the site of ICH.  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