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   1925篇
  免费   81篇
  国内免费   10篇
耳鼻咽喉   8篇
儿科学   64篇
妇产科学   55篇
基础医学   322篇
口腔科学   20篇
临床医学   225篇
内科学   446篇
皮肤病学   11篇
神经病学   211篇
特种医学   43篇
外国民族医学   1篇
外科学   237篇
综合类   6篇
一般理论   1篇
预防医学   87篇
眼科学   9篇
药学   142篇
中国医学   2篇
肿瘤学   126篇
  2024年   1篇
  2023年   16篇
  2022年   31篇
  2021年   74篇
  2020年   20篇
  2019年   32篇
  2018年   50篇
  2017年   31篇
  2016年   38篇
  2015年   48篇
  2014年   59篇
  2013年   90篇
  2012年   158篇
  2011年   171篇
  2010年   93篇
  2009年   82篇
  2008年   144篇
  2007年   129篇
  2006年   129篇
  2005年   99篇
  2004年   113篇
  2003年   87篇
  2002年   117篇
  2001年   20篇
  2000年   13篇
  1999年   19篇
  1998年   23篇
  1997年   15篇
  1996年   16篇
  1995年   8篇
  1994年   13篇
  1993年   9篇
  1992年   9篇
  1991年   8篇
  1990年   6篇
  1989年   10篇
  1988年   5篇
  1987年   3篇
  1986年   5篇
  1985年   5篇
  1984年   5篇
  1982年   1篇
  1979年   1篇
  1978年   3篇
  1977年   3篇
  1975年   1篇
  1974年   1篇
  1972年   1篇
  1968年   1篇
排序方式: 共有2016条查询结果,搜索用时 31 毫秒
61.

Background

The American Thyroid Association (ATA) published recommendations for the timing of prophylactic surgery for medullary thyroid carcinoma based on the specific mutation, patient age, family history, and serum calcitonin levels. The aim of this study was to assess the role of preoperative basal calcitonin (prebCt) levels in predicting the presence of medullary carcinoma of the thyroid in patients with RET mutations.

Methods

We conducted a retrospective study in two endocrine surgery departments. Between 1986 and 2012, a total of 32 patients with RET mutations underwent prophylactic thyroidectomy. The patients were stratified into four ATA risk levels: A, B, C, and D.

Results

All of the patients were biologically cured. Microcarcinoma was observed in the final pathology report for four of the 20 patients with normal prebCt (25 %) and for nine of the 12 patients with elevated prebCt (75 %). In the level A group, four patients with normal prebCt and one patient with elevated prebCt presented with microcarcinoma. In the level C group, one patient with normal prebCt and six of the seven patients with elevated prebCt (86 %) presented with microcarcinoma.

Conclusions

PrebCt can predict the presence of microcarcinoma according to surgical pathological analysis. Patients with microcarcinoma can be biochemically and clinically cured using prophylactic thyroidectomy.  相似文献   
62.
63.
ObjectivesTo analyze to what extent partial nephrectomy (PN) is superior to radical nephrectomy (RN) in preserving renal function outcome in relation to tumor size indication.Methods and materialsClinical data from 973 patients operated at 9 academic institutions were retrospectively analyzed. Glomerular filtration rate (GFR) before and after surgery was calculated with the abbreviated Modification of the Diet in Renal Disease equation. For a fair comparison between the 2 techniques, all imperative indications for PN were excluded. A shift to a less favorable GFR group following surgery was considered clinically significant.ResultsMedian age at diagnosis was 60 years (19–91). Tumor size was smaller than 4 cm in 665 (68.3%) cases and larger than 4 cm in 308 (31.7%) cases. PN and RN were performed in 663 (68.1%) and 310 (31.9%) patients, respectively. In univariate analysis, patients undergoing PN had a smaller risk for developing significant GFR change following surgery than those undergoing RN did. This was true for tumors≤4 cm (P = 0.0001) and for tumors>4 cm (P = 0.0001). In multivariate analysis, the following criteria were independent predictive factors for developing significant postoperative GFR loss: the use of RN (P = 0.0001), preoperative GFR<60 ml/min (P = 0.0001), tumor size≥4 cm (P = 0.0001), and older age at diagnosis (P = 0.0001).ConclusionsThe renal function benefit carried out by elective PN over RN persists even when expanding nephron-sparing surgery indications beyond the traditional 4-cm cutoff.  相似文献   
64.
SARS-CoV-2 nasopharyngeal shedding contributes to the spread of the COVID-19 epidemic. Among 3271 COVID-19 patients treated at the Hospital University Institute Méditerranée Infection, Marseille, France from 3 March to 27 April 2020, tested at least twice by qRT-PCR, the median SARS-CoV-2 nasopharyngeal shedding duration was 6 days (range 2–54 days). Compared with short shedders (qRT-PCR positivity < 10 days), 34 (1.04%) persistent shedders (qRT-PCR positivity ≥ 17 days; mean ± SD: 23.3 ± 3.8 days) were significantly older, with associated comorbidities, exhibiting lymphopenia, eosinopenia, increased D-dimer and increased troponin (p < 0.05), and were hospitalized in intensive care unit in 17.7% vs. 1.1% of cases (p < 0.0001). Viral culture was positive in six persistent shedders after day 10, including in one patient after day 17, and no viral co-pathogen was detected in 33 tested patients. Persistent shedders received azithromycin plus hydroxychloroquine ≥ 3 days in 26/34 (76.5%) patients, a figure significantly lower than in short shedders (86.6%) (p = 0.042). Accordingly, mortality was 14.7% vs. 0.5% (p < 0.0001). Persistent shedding was significantly associated with persistent dyspnea and anosmia/ageusia (p < 0.05). In the context of COVID-19 treatment, including treatment with azithromycin plus hydroxychloroquine, the persistence of SARS-CoV-2 nasopharyngeal shedding was a rare event, most frequently encountered in elderly patients with comorbidities and lacking azithromycin plus hydroxychloroquine treatment.  相似文献   
65.
66.
BackgroundInformation on the characteristics of patients with nosocomial influenza and associated complications is scarce. This study compared epidemiological and clinical characteristics of patients admitted with hospital‐acquired influenza (HAI) to those with community‐acquired influenza (CAI) and analyzed risk factors associated with complications.MethodsThis retrospective, observational study included all adult patients with confirmed influenza virus infection admitted to Son Espases University Hospital during the influenza season in Spain (October to May) from 2012‐2013 to 2015‐2016. Symptom onset before admission was included as CAI, and 2 days after admission or within 48 hours after previous discharge were considered as HAI.ResultsOverall, 666 patients with laboratory‐confirmed influenza were included; 590 (88.6%) and 76 (11.4%) had CAI and HAI, respectively. Baseline characteristics and vaccination rates were similar in both groups. Patients with HAI had significantly fewer symptoms, less radiological alterations, and earlier microbiological diagnosis than those with CAI. Eighty‐five (14.4%) and 20 (27.6%) CAI and HAI patients, respectively, experienced at least one complication, including septic shock, admission to the intensive care unit, mechanical ventilation or evolution to death (any one, P = .003). Univariate and multivariate binary logistic regression was performed to assess independent risk factors associated with the occurrence of complications: nosocomial infection, diabetes, oseltamivir treatment, having received no vaccination, microbiological delay, dyspnea, and the state of confusion were the most important significant factors.ConclusionsOur study shows the need to implement microbiological diagnostic measures in the first 48 hours to reduce HAI frequency and associated complications.  相似文献   
67.
68.
AIM: The aim of the study was to determine whether simple routine parameters evaluating the first session of transarterial chemoembolization (variation in alfa-fetoprotein concentration, tumor lipiodol uptake, and post-embolization syndrome) can predict survival of patients treated for hepatocellular carcinoma. METHODS: Seventy-two patients treated with transarterial chemoembolization and evaluated one month after the first sessions with CT scan were included. Transarterial chemoembolization session included hepatic arteriography, lipiodol and doxorubicin (50 mg) emulsion injection, followed by gelatin sponge embolization. The following variables were studied in univariate and multivariate analysis: 6 recorded at the first session (age, cirrhosis etiology, Child-Pugh class, tumor number, largest lesion size, and alpha-fetoprotein concentration), and 5 recorded after the first session (variation in alfa-fetoprotein concentration, tumor lipiodol uptake, post-embolization syndrome, mean interval between each session, and associated treatment). RESULTS: Mean follow-up was 22.7 months (4-106). Mean survival was 30.4 months (95% CI: 23. 3-37.5). Actuarial survival at 1, 2, 3 and 5 years was respectively 65.5%, 44%, 29.5%, and 18%. The only independent prognostic factors in multivariate analysis were the Child Pugh class and the mean interval between sessions (P<0.001 and<0.01 respectively). None of our criteria evaluating the first TACE session significantly influenced survival. CONCLUSION: The 3 parameters (variation in alpha-fetoprotein concentration, tumor lipiodol uptake and post-embolization syndrome) after the first transarterial chemoembolization did not predict survival. They could not be used to determine which patient could benefit from repeated transarterial chemoembolization sessions.  相似文献   
69.
70.
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