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   54629篇
  免费   4700篇
  国内免费   1230篇
耳鼻咽喉   825篇
儿科学   496篇
妇产科学   160篇
基础医学   1997篇
口腔科学   2234篇
临床医学   8611篇
内科学   6099篇
皮肤病学   191篇
神经病学   2895篇
特种医学   17632篇
外国民族医学   27篇
外科学   4851篇
综合类   6150篇
现状与发展   4篇
预防医学   842篇
眼科学   3084篇
药学   1390篇
  8篇
中国医学   155篇
肿瘤学   2908篇
  2024年   74篇
  2023年   1040篇
  2022年   1503篇
  2021年   2435篇
  2020年   2042篇
  2019年   1816篇
  2018年   1857篇
  2017年   1768篇
  2016年   1879篇
  2015年   1892篇
  2014年   3735篇
  2013年   2976篇
  2012年   3298篇
  2011年   3529篇
  2010年   3098篇
  2009年   3210篇
  2008年   3129篇
  2007年   3152篇
  2006年   2815篇
  2005年   2395篇
  2004年   1945篇
  2003年   1614篇
  2002年   1321篇
  2001年   1189篇
  2000年   934篇
  1999年   797篇
  1998年   607篇
  1997年   625篇
  1996年   491篇
  1995年   468篇
  1994年   417篇
  1993年   304篇
  1992年   245篇
  1991年   207篇
  1990年   195篇
  1989年   190篇
  1988年   164篇
  1987年   177篇
  1986年   125篇
  1985年   155篇
  1984年   161篇
  1983年   94篇
  1982年   140篇
  1981年   114篇
  1980年   78篇
  1979年   61篇
  1978年   34篇
  1977年   39篇
  1976年   23篇
  1974年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
IntroductionThe impact of the nasal septum morphology on the severity of obstruction symptoms has not been fully explored.ObjectiveThis study aimed to investigate whether the morphology of the deviated nasal septum assessed by computed tomography may explain nasal obstruction severity.MethodsThe study included 386 patients who were referred to the computed tomography examination of the paranasal sinuses. Patient selection criteria were the absence of facial anomalies, facial trauma, nasal surgery, and sinonasal tumors. Computed tomography images were used to estimate deviated nasal septum prevalence, the prevalence of Mladina's seven types of deviated nasal septum, and to measure the deviated nasal septum angle. Nasal obstruction severity was assessed by the nasal obstruction symptom evaluation, NOSE scale. The relationship between NOSE score, deviated nasal septum morphology, and deviated nasal septum angle was performed by a statistical regression model on the reduced sample of 225 patients.ResultsThe prevalence of deviated nasal septum was 92.7%. Type 7 deviated nasal septum was the most frequent (34.2%) followed by type 5 (26.2%) and type 3 (23.6%). The worst NOSE scores were recorded in the type 2 deviated nasal septum (45.00 ± 28.28). The mean deviated nasal septum angle in patients with nasal obstruction was 8.5° ± 3.24. NOSE scores were not significantly associated with deviated nasal septum types and angles.ConclusionPatients with different types of deviated nasal septum have different NOSE scores. Computed tomography morphology of the deviated nasal septum could not fully explain the severity of nasal obstruction.  相似文献   
52.
53.
BackgroundIn patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium99m (Tc99) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status.MethodsPatients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02–0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc99 and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed.ResultsFifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given.DiscussionIt is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer.  相似文献   
54.
ObjectiveTo assess the association between loss of lumbar skeletal muscle mass and density during neoadjuvant chemotherapy (NACT) and postoperative complications after interval cytoreductive surgery (CRS) in older patients with ovarian cancer.Materials and methodsThis multicenter, retrospective cohort study included patients aged 70 years and older with primary advanced stage ovarian cancer (International Federation of Gynecology and Obstetrics stage III-IV), treated with NACT and interval CRS. Skeletal muscle mass and density were retrospectively assessed using Skeletal Muscle Index (SMI) and Muscle Attenuation (MA) on routinely made Computed Tomography scans before and after NACT. Loss of skeletal muscle mass or density was defined as >2% decrease per 100 days in SMI or MA during NACT.ResultsIn total, 111 patients were included. Loss of skeletal muscle density during NACT was associated with developing any postoperative complication ≤30 days after interval CRS both in univariable (Odds Ratio (OR) 3.69; 95% Confidence Interval (CI) 1.57–8.68) and in multivariable analysis adjusted for functional impairment and WHO performance status (OR 3.62; 95%CI 1.27–10.25). Loss of skeletal muscle density was also associated with infectious complications (OR 3.67; 95%CI 1.42–9.52) and unintended discontinuation of adjuvant chemotherapy (OR 5.07; 95%CI 1.41–18.19). Unlike loss of skeletal muscle density, loss of skeletal muscle mass showed no association with postoperative outcomes.ConclusionIn older patients with ovarian cancer, loss of skeletal muscle density during NACT is associated with worse postoperative outcomes. These results could add to perioperative risk assessment, guiding the decision to undergo surgery or the need for perioperative interventions.  相似文献   
55.
The purpose of this review is to describe the current state of the art in clinical imaging for NICU patients, divided into major areas that correspond to likely phenotypes of neonatal respiratory disease: airway abnormalities, parenchymal disease, and pulmonary vascular disease. All common imaging modalities (ultrasound, X-ray, CT, and MRI) are discussed, with an emphasis on modalities that are most relevant to the individual underlying aspects of disease. Some promising aspects of dynamic and functional imaging are included, where there may be future clinical applicability.  相似文献   
56.
ObjectiveTo evaluate the long-term incidence and outcome of aortic interventions for medically managed uncomplicated thoracic aortic dissections.MethodsBetween January 2012 and December 2018, 91 patients were discharged home with an uncomplicated, medically treated aortic dissection (involving the descending aorta with or without aortic arch involvement, no ascending involvement). After a median period of 4 (first quartile: 2, third quartile: 11) months, 30 patients (33%) required an aortic intervention. Patient characteristics, radiographic, treatment, and follow-up data were compared for patients with and without aortic interventions. A competing risk regression model was analyzed to identify independent predictors of aortic intervention and to predict the risk for intervention.ResultsPatients who underwent aortic interventions had significantly larger thoracic (P = .041) and abdominal (P = .015) aortic diameters, the dissection was significantly longer (P = .035), there were more communications between both lumina (P = .040), and the first communication was significantly closer to the left subclavian artery (P = .049). A descending thoracic aortic diameter exceeding 45 mm was predictive for an aortic intervention (P = .001; subdistribution hazard ratio: 3.51). The risk for aortic intervention was 27% ± 10% and 36% ± 11% after 1 and 3 years, respectively. Fourteen patients (47%) underwent thoracic endovascular aortic repair, 11 patients (37%) thoracic endovascular aortic repair and left carotid to subclavian bypass, 3 patients (10%) total arch replacement with the frozen elephant trunk technique, and 2 patients (7%) thoracoabdominal aortic replacement. We observed no in-hospital mortality.ConclusionsThe need for secondary aortic interventions in patients with initially medically managed, uncomplicated descending aortic dissections is substantial. The full spectrum of aortic treatment options (endovascular, hybrid, conventional open surgical) is required in these patients.  相似文献   
57.
58.
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making.  相似文献   
59.
《Cirugía espa?ola》2023,101(2):116-122
IntroductionMetastasis is remaining one of the major problems in cancer treatment. Like many other malignancies, urogenital tumors originating from kidney, prostate, testes, and bladder tend to metastasize to the lungs.The aim of this retrospective study is to evaluate the operative results and prognosis of pulmonary metastasectomy in patients with primary urogenital tumors.MethodsThis study was approved by the local ethical committee. We retrospectively analyzed the surgical and oncological results of patients who underwent lung resections for urogenital cancer metastases in our department between 2002 and 2018. Demographic data and clinicopathological features were extracted from the medical records. Survival outcomes according to cancer subtypes and early postoperative results of VATS and thoracotomy were analyzed.Results22 out of 126 patients referred for pulmonary metastasectomy to our department had metastases from urogenital tumors. These patients consisted of 17 males and five females. Their metastasis originated from renal cell carcinoma (RCC; n = 9), bladder tumor (n = 7), testis tumors (n = 4), and prostate cancer (n = 2). There was no intraoperative complication. Postoperative complications were seen in 2 patients.ConclusionsAlthough pulmonary metastasectomy in various types of tumors is well known and documented, the data is limited for metastases of urogenital cancers in the literature. Despite the limitations of this study, we aim to document our promising results of pulmonary metastasectomy in patients with primary urogenital tumors and wanted to emphasize the role of minimally invasive approaches.  相似文献   
60.
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