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   6606篇
  免费   675篇
  国内免费   183篇
耳鼻咽喉   1174篇
儿科学   182篇
妇产科学   50篇
基础医学   1101篇
口腔科学   164篇
临床医学   701篇
内科学   763篇
皮肤病学   95篇
神经病学   90篇
特种医学   133篇
外国民族医学   1篇
外科学   570篇
综合类   963篇
预防医学   221篇
眼科学   150篇
药学   745篇
  6篇
中国医学   190篇
肿瘤学   165篇
  2024年   16篇
  2023年   126篇
  2022年   215篇
  2021年   300篇
  2020年   281篇
  2019年   300篇
  2018年   241篇
  2017年   243篇
  2016年   284篇
  2015年   230篇
  2014年   456篇
  2013年   533篇
  2012年   418篇
  2011年   401篇
  2010年   308篇
  2009年   311篇
  2008年   264篇
  2007年   284篇
  2006年   261篇
  2005年   238篇
  2004年   227篇
  2003年   175篇
  2002年   177篇
  2001年   140篇
  2000年   110篇
  1999年   120篇
  1998年   117篇
  1997年   101篇
  1996年   76篇
  1995年   74篇
  1994年   55篇
  1993年   71篇
  1992年   51篇
  1991年   28篇
  1990年   27篇
  1989年   28篇
  1988年   32篇
  1987年   15篇
  1986年   15篇
  1985年   22篇
  1984年   22篇
  1983年   16篇
  1982年   13篇
  1981年   9篇
  1980年   12篇
  1979年   8篇
  1978年   4篇
  1977年   2篇
  1976年   3篇
  1972年   2篇
排序方式: 共有7464条查询结果,搜索用时 12 毫秒
51.
应用因特网对SARS病毒M蛋白B细胞抗原表位的预测   总被引:7,自引:1,他引:6  
目的:预测SARS冠状病毒M蛋白的B细胞表位。方法:采用EMBOSS软件结合Hopp&woods亲水性参数、Janin可及性参数、极性参数、柔韧性参数及二级结构方案对SARS冠状病毒M蛋白的B细胞表位进行了预测,并用吴玉章等已建立的B细胞表位预测方法进行评述。结果:SARS冠状病毒M蛋白B细胞识别的表位可能位于第3~13和153~166位氮基酸等区域内或附近,这2个被预测的表位均含有β—转角和无规卷曲结构。结论:该研究对应用合成肽抗原进行SARS早期诊断研究及相关抗体的制备具有重要指导意义。  相似文献   
52.
When nasotracheal intubation with a fiberoptic bronchoscope is performed, the tube may be blocked in the nasal cavity or larynx, resulting in several complications including epistaxis and hoarseness. We review the causes and complications of tube blockage and discuss optimal techniques for minimizing it.  相似文献   
53.
A chromium electroplating worker, suffering from epistaxis during work, was found to have nasal septum perforation. To determine the etiology and prevalence of nasal septum lesions, we conducted a survey of seven chromium electroplating factories and examined 79 workers. Forty workers from three aluminum electroplating factories were also enrolled as the reference group. Subjects were thoroughly examined by an otolaryngologist and each of them provided a blood and urine sample. A questionnaire interview regarding symptoms of the upper respiratory tract, past medical history, life style, and work history was also conducted. Air chromium concentrations were measured by taking area samples for 4–6 hours. Based on field observation and chromium measurements, we divided chromium electroplating into three different exposure zones: workers directly dealing with electroplating tanks (n = 31), other process workers (n = 29), and office workers and drivers (n = 19). Among the 79 chromium electroplating workers, there were 16 cases of nasal septum perforation, and 42 with either scar formation or ulceration; 10 chromium electroplating workers developed skin ulcers after performing chrome plating. No workers from aluminum electroplating factories had any nasal septum or skin abnormalities. There was a consistent trend between the degree of chromium exposure and the signs and symptoms related to the nose, throat, and skin. Immediate improvement of occupational hygiene is warranted.  相似文献   
54.
目的观察耳廓复合游离组织瓣连续法修复鼻翼缺损的疗效,以探讨鼻翼缺损的有效修复手段。方法耳廓复合游离组织瓣2次连续法修复鼻翼缺损7例,移植物面积0.5cm×0.7cm~0.8cm×1.2cm。结果7例耳廓复合游离组织瓣移植后全部成活。术后随访6~18个月,移植物无明显回缩,鼻外形满意。结论耳廓复合游离组织瓣连续移植修复鼻翼缺损,适合较严重鼻翼缺损,手术成功率高,术后鼻外形满意,双侧分次取材,耳廓外形双侧对称无畸形。  相似文献   
55.
目的 探讨鼻窦CT扫描在内窥镜鼻窦手术中的应用价值。方法 回顾性对80例慢性鼻窦炎患者鼻窦CT扫描与手术中所见进行分析总结。结果 冠状位CT扫描鼻窦病变发现率高,辅以水平CT扫描,鼻窦精细结构、病变范围和程度能够清楚地显示,符合术中所见。结论 鼻窦CT扫描能精确显示鼻窦结构及病变,能正确指导鼻窦内窥镜手术。  相似文献   
56.
齿槽裂植骨整复畸形鼻   总被引:1,自引:1,他引:0  
目的:探讨齿槽裂及鼻底进行天然多孔骨(Bio-OssCollagen材料)移植整复畸形鼻的可行性和临床疗效。方法:对12例齿槽裂及鼻底行Bio-OssCollagen材料植入整复手术。结果:随访9 ̄12月外形恢复良好,唇部和鼻底丰满,鼻翼提升,X线片示齿槽裂及鼻底植入Bio-OssCollagen材料基本被自体骨取代。结论:用Bio-OssCollagen材料代替自体骨植入齿槽裂及鼻底整复畸形鼻,均效果良好。  相似文献   
57.
About 4-10% of children and adolescents suffer from migraine. In the last few years, several studies have been performed to assess the efficacy and safety of triptans for the acute treatment of migraine in children and adolescents. Only sumatriptan nasal spray has been approved for the treatment of acute migraine with or without aura in adolescents aged 12-17 years in Europe. This review describes the results of the studies with sumatriptan nasal spray that have been performed in children and adolescents, including a study performed in the Netherlands.  相似文献   
58.
Background Prosia gland in D2 (PGD2) is a very important mast cell product during the early-phase nasal allergic reaction. However, the quantification of PGD2 in nasal secretions has not yet been well established. Objective Quantitative determination of PGD2 in nasal secretions of atopic patients (n=17) after nasal allergen challenge (NAC) and in non-allergic healthy volunteers (n=10). Methods The nasal microsuction sampling technique was used to obtain the nasal secretions with an exactly known and minimally diluted volume. A sensitive and specific enzyme immunoassay was chosen to measure the more stable 11-methoxime derivative of PGD2. which was obtained after extraction in acelone/ethanol and conversion using methoxamine-HCl. The concentrations of PGD2 in nasal secretions obtained from 10 non-allergic healthy volunteers were used as reference values. Results There was no significant difference in the concentrations of PGD2 between men (median: 569pg/mL) and women (median: 407pg/mL), nor between the baseline concentrations from atopic patients (median: 410pg/mL) and non-allergic controls (median: 477 pg/mL). In the atopic patient group, PGD2 did not significantly increase during the entire sampling period after NAC. The absence of PGD2 response contrasted with the nasal symptoms manifested by sneezing, increased nasal airway resistance, and the significant increases of the concentrations of histamine, tryptase, and leukotriene C4 (LTC4) 5min after NAC. Conclusion This observation suggests that the measurement of PGD2 alone in the nasal secretions does not give reliable information on mast cell activation during a nasal allergic reaction.  相似文献   
59.
The local mean and the average difference of four pairs of test locations within the 26° visual field, situated above and below the horizontal nasal meridian, were used to predict the global field indices MD and CLV of the Gl glaucoma program. Out of 539 examinations (194 eyes suspected of having glaucoma), the local indices NDIFF (describing asymmetrical behavior around the nasal horizontal meridian), ND0 (the mean defect in the nasal region), and the global indices MD and CLV were calculated. Seven hundred fifty-five examinations (446 normal eyes) served as a control group. First and second examinations of 146 glaucoma suspect eyes were used to calculate the retest reliability scores for the indices in question. When analyzing the glaucoma suspects, the local index NDIFF, together with the local mean defect, ND0, yielded highly reliable estimates of the global indices MD and CLV, with a retest correlation r = 0.86 for NDIFF, and r = 0.96 for ND0. The covariance of NDIFF with CLV was r = 0.67, while the co-variance of MD with ND0 was r = 0.95.The ranges of the local indices ND0 and NDIFF were each classified into normal range and range of suspected pathology, in analogy to the normal and pathological ranges of the global field indices. Equivalence of the local indices with the corresponding ranges of MD and CLV was investigated and the results are shown. The establishment of local indices may prove to be a powerful tool in early detection of glaucomatous damage.  相似文献   
60.
Rhinosinusitis is diagnosed frequently in clinical practice, but the term may in fact encompass a wide spectrum of diseases. Inflammation of the nasal and sinus mucosa can arise from various causes and lead to different sequelae. Moreover, the term rhinosinusitis is more accurate than sinusitis. Causes range from a viral infection leading to the common cold to an invasive, fungal infection. An accurate diagnosis is important because effective therapy is available if recognized early and if specific therapy is used. Importantly, there is a close relationship between upper and lower airway disease and each have unique structural and functional differences that make an understanding of rhinosinusitis important not only for upper airway disease, but also for the management of asthma. All too often, rhinosinusitis becomes chronic and this becomes a challenge because medical therapy may not be sufficient to control disease. Finally, we should note that the differential diagnosis of rhinosinusitis is extensive and physicians should place heavy emphasis not only on the history, but also on appropriate imaging studies. A normal exam does not rule out the possibility or rhinosinusitis. Finally, we should emphasize that effective treatment is dependent on the etiology of the symptoms but also dependent on whether it is acute or chronic.  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