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   124860篇
  免费   14648篇
  国内免费   6209篇
耳鼻咽喉   1724篇
儿科学   2136篇
妇产科学   2991篇
基础医学   12657篇
口腔科学   4575篇
临床医学   18078篇
内科学   21512篇
皮肤病学   1343篇
神经病学   7416篇
特种医学   4490篇
外国民族医学   42篇
外科学   14909篇
综合类   14847篇
现状与发展   35篇
一般理论   20篇
预防医学   8713篇
眼科学   3179篇
药学   10868篇
  56篇
中国医学   4822篇
肿瘤学   11304篇
  2024年   431篇
  2023年   2546篇
  2022年   4132篇
  2021年   5522篇
  2020年   4692篇
  2019年   3690篇
  2018年   4830篇
  2017年   4175篇
  2016年   4308篇
  2015年   5922篇
  2014年   7527篇
  2013年   7323篇
  2012年   8255篇
  2011年   8962篇
  2010年   6300篇
  2009年   5726篇
  2008年   5986篇
  2007年   5994篇
  2006年   6022篇
  2005年   6132篇
  2004年   4136篇
  2003年   3672篇
  2002年   3233篇
  2001年   2815篇
  2000年   2917篇
  1999年   3065篇
  1998年   2071篇
  1997年   1951篇
  1996年   1836篇
  1995年   1545篇
  1994年   1281篇
  1993年   894篇
  1992年   1170篇
  1991年   957篇
  1990年   819篇
  1989年   740篇
  1988年   715篇
  1987年   633篇
  1986年   516篇
  1985年   422篇
  1984年   283篇
  1983年   248篇
  1982年   167篇
  1981年   165篇
  1980年   128篇
  1979年   147篇
  1978年   86篇
  1977年   99篇
  1976年   75篇
  1975年   71篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
81.
实时三维超声对室间隔缺损的直视效果及影响因素分析   总被引:2,自引:0,他引:2  
目的探讨实时三维超声(RT3DE)对室间隔缺损(VSD)全貌的直视效果及其影响因素。 方法应用RT3DE对238例VSD患者进行检查,其中包括法洛四联症(TOF)36例、完全型心内膜垫缺损(TECD)2例和十字交叉心2例。获取并切割“全容积三维”图像,寻找最佳视角显示病变结构全貌。 结果RT3DE对中型和大型VSD(直径≥5mm)的直视效果优于小型VSD(〈5mm)。可显示缺损的形状、部位及毗邻结构。胸骨旁四腔位和心底短轴位RT3DE图像效果最佳,胸骨旁长轴位及心尖五腔位次之。 结论VSD的大小、部位及三维图像质量是决定RT3DE观察效果的主要因素。RT3DE可清晰直视中型及大型VSD的全貌。  相似文献   
82.
83.
84.
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience.  相似文献   
85.
Long-term daily use of gamma-hydroxybutyrate (GHB) and related compounds has recently been associated with a withdrawal syndrome. To the best of the authors' knowledge, there are currently no animal models of GHB withdrawal. OBJECTIVES: The authors studied and described the effect of chronic dosing of GHB (3-6 days) on tolerance and withdrawal in a rat model. METHODS: Rats were administered GHB every three hours via intraperitoneal catheter. Groups of rats (2 per group) were dosed with GHB for either 3 (24 doses), 4 (32 doses), 5 (40 doses), or 6 (48 doses) days. The GHB dose was 0.25 g/kg for doses 1-8, 0.75 g/kg for doses 9-12, 1 g/kg for doses 13-16, 1.25 g/kg for doses 17-24, 1.5 g/kg for doses 25-32, 1.75 g/kg for doses 33-40, and 2 g/kg for doses 41-48. Following the last dose of GHB, the rats were scored using a 16-point ethanol intoxication-withdrawal scale rating spontaneous behaviors, response to handling, grooming, and neurological signs. Lower scores indicate intoxication, while higher scores indicate withdrawal. Scores were recorded at hours 0, 1, 2, 3, 4, 5, 6, 9, 12, and 24. RESULTS: Tolerance: Rats dosed with GHB for more days were less intoxicated one hour after their last GHB dose despite receiving higher doses. WITHDRAWAL: The scores for all rats dosed with GHB increased at hours 4 (p = 0.028), 5 (p = 0.037), 6 (p = 0.007), and 9 (p = 0.024) after the last dose, indicating withdrawal. The scores demonstrated a linear increase dependent upon the number of days of GHB dosing at hours 3 (p < 0.000), 4 (p = 0.004), 5 (p = 0.002), and 12 (p = 0.039) as well as prior to the last dose at hour 0 (p = 0.000). No rats developed seizures. CONCLUSIONS: Tolerance and mild withdrawal in rats can be induced by administering intraperitoneal GHB every three hours for 3-6 days. More prolonged dosing and higher doses of GHB may be necessary to induce severe withdrawal.  相似文献   
86.
[目的]探讨负压进针在心血管内科病人的静脉输注中是否优于常规进针法.[方法]将2004年1月-2005年6月我科收治且静脉穿刺难度大的病人随机分为实验组和对照组,实验组150例应用负压进针法,对照组150例应用常规进针法,比较两组的穿刺成功率和回血率.[结果]负压进针法比常规进针法的穿刺成功率提高了12%,回血率提高了13%,两组间穿刺成功率和回血率的差异有统计学意义(P<0.01).[结论]负压进针大大提高了穿刺成功率和回血率,减少了病人的痛苦,提高护理人员的工作效率和住院病人满意度.  相似文献   
87.
目的:评价运动员动态心电图中特殊事件的意义。方法:为30名身体健康无自觉症状的运动员作动态心电图检查。然后对检查结果进行统计分析。结果:ST抬高18人,ST下移4人,室性早搏(VE)9人,室速(VT)1人,室上性早搏(SVE)12人,室上速(SVT)2人,I°房室传导阻滞(I°AVB)1人,Ⅱ°房室传导阻滞(Ⅱ°AVB)4人。结论:动态心电图中特殊事件的临床意义与事件出现的时间、频度有关。  相似文献   
88.
OBJECTIVES: Physicians commonly use etomidate for adult rapid-sequence intubation (RSI), but the manufacturer does not recommend its use for children under 10 years of age due to a lack of data. The authors present their experience with etomidate for pediatric RSI in order to further develop its risk-benefit profile in this age group. METHODS: Trained abstractors reviewed the medical records for all children under 10 years old who received etomidate for RSI between July 1996 and April 2001. RESULTS: 105 children, with an average age of 3 (+/-2.9) years, received a median dose of 0.32 (+/-0.12) mg/kg of etomidate. The systolic blood pressure increased an average of 4 mm Hg (95% CI = -3.3 to 9.2); the diastolic blood pressure increased 7 mm Hg (95% CI = -3.1 to 11) within 10 minutes of receiving etomidate. The heart rate increased an average of 10 beats/min (95% CI = 4.0 to 17.4). Complications included three patients who vomited within 10 minutes of etomidate administration. There were no cases of documented myoclonus, status epilepticus, or new-onset seizures. Thirty-eight patients received corticosteroids during the hospital course, none for suspected adrenal insufficiency. Three patients died, all from severe brain injury. CONCLUSIONS: In children less than 10 years old, etomidate seems to produce minimal hemodynamic changes, and appears to have a low risk of clinically important adrenal insufficiency, myoclonus, and status epilepticus. The association between etomidate and emesis (observed in less than 3% of enrolled patients) remains unclear. For clinical situations in which minimal blood pressure changes during RSI are critical, etomidate appears to have a favorable risk-benefit profile for children under 10 years old.  相似文献   
89.
Surfactant     
Surfactant, a complex substance containing specific proteins and phospholipids, is essential for gas exchange in the lungs. Research shows that surfactant not only lowers surface tension, but also plays a role in host defense. Surfactant replacement therapy is a cornerstone in the treatment of respiratory distress syndrome in premature infants. New information on endogenous surfactant composition including surfactant apoproteins has led to advances in the surfactant replacement products currently available. Because of the success of surfactant deficiency treatment in neonates, surfactant replacement therapy has been studied in both the pediatric and adult population for the treatment of other respiratory disorders. This article describes the composition, metabolism, and function of endogenous surfactant and other uses of surfactant replacement therapies in neonates.  相似文献   
90.
我们首次报道一例雷公藤多甙中毒导致急性重症胰腺炎的病例,其病理生理变化、临床表现和转归于以往的报道颇有不同。  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