首页 | 官方网站   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   19589篇
  免费   1558篇
  国内免费   592篇
医药卫生   21739篇
  2024年   35篇
  2023年   229篇
  2022年   464篇
  2021年   692篇
  2020年   457篇
  2019年   493篇
  2018年   573篇
  2017年   509篇
  2016年   496篇
  2015年   665篇
  2014年   807篇
  2013年   930篇
  2012年   1391篇
  2011年   1499篇
  2010年   894篇
  2009年   726篇
  2008年   1101篇
  2007年   1106篇
  2006年   1152篇
  2005年   1132篇
  2004年   929篇
  2003年   789篇
  2002年   773篇
  2001年   543篇
  2000年   535篇
  1999年   486篇
  1998年   190篇
  1997年   192篇
  1996年   160篇
  1995年   115篇
  1994年   114篇
  1993年   80篇
  1992年   206篇
  1991年   189篇
  1990年   167篇
  1989年   146篇
  1988年   117篇
  1987年   114篇
  1986年   91篇
  1985年   64篇
  1984年   43篇
  1983年   31篇
  1982年   45篇
  1981年   39篇
  1980年   35篇
  1979年   36篇
  1978年   32篇
  1977年   19篇
  1975年   20篇
  1973年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
“搓滚舒筋”练功疗法,是一种以竹筒为简易器械的脚底搓滚练功治疗“筋挛缩”症的方法。最早文献见于马王堆汉墓出土的帛书《五十二病方》,起码有两干多年的渊源。骨伤科常用之,内、外诸科亦有用之。这一传统疗法,筒、便、廉、验,值得弘扬。  相似文献   
3.
4.
5.
6.
Epiphrenic diverticulum is rare, comprising of about 10% of all esophageal diverticula. Carcinoma arising within such a diverticulum is even less common. We report on two patients with squamous cell carcinoma arising from an epiphrenic diverticulum. Some features of malignant change related to the epiphrenic diverticula were misdiagnosed or missed in our cases and other reports due to lack of clinical experience. It is important to exclude the possibility of malignancy as this is vital for surgical planning. Although the prognosis for patients with malignancy arising from an epiphrenic diverticulum is generally poor, a high index of suspicion may increase the chance of cure.  相似文献   
7.
咬肌与颅面形态的关系   总被引:3,自引:0,他引:3  
目的探讨咬肌与颅面形态之间的关系,了解咬肌体积与邻近骨骼结构的大小及形态的相关性。方法对40例要求改变脸型者进行磁共振成像(MRI)测量,人体测量,头部正位、侧位和下颌骨曲面断层X线检查,测量并计算咬肌体积(MsV),测量头长(HL)、头宽(HB)、面长(FL)、面宽(FB)、下颌角间宽(IB)、下颌骨体长(CL)、下颌角切线长(MAL)、下颌角角度(JA),计算颜面形态指数FI(FL/FB)、头颅指数C(IHB/HL)。用SPSS11.5软件统计分析MsV与HI。HB、FL、FB、IB、CL、MAL、JA、FI、CI之间的相关性。结果MsV与JA呈明显负相关,与CL、MAL、IB、FB、HL呈明显正相关,与CL、FI、HB无明显相关性。结论咬肌肥大可能是方脸面型的成因之一,是影响面型的重要因素。  相似文献   
8.
After measurement of normal renal function, dog kidneys (n = 52) were subjected to 3, 15, or 30 min of normothermic warm ischemia (WI). After 24 hr of preservation by simple hypothermic storage (SHS) in a modified Collins solution, autotransplant was done and renal function was again measured beginning at 1 hr. Compared with preharvest values, kidneys with minimal (3 min) WI had significantly decreased clearances of creatinine (Cr) and para-aminohippuric acid (PAH), PAH extraction, absolute and fractional Na reabsorption, Na excretion, and urinary Na concentration; no change in urine flow rate or K excretion; and significantly increased fractional excretion of Na, K, and H2O. Compared with minimal WI, 30-min WI produced further significant decreases in clearances of Cr, PAH, and PAH extraction; and further increases in fractional excretion of Na, K, and H2O. Urine flow was also decreased by about half and urine Na concentration rose significantly. Several parameters were very significantly correlated with the length of WI, but the most reliable index was the fractional reabsorption of Na. When several functional parameters were used together, kidneys with significant (30 min) WI prior to preservation could be identified with a high degree of statistical reliability.  相似文献   
9.
Mingying  Lai  Ningli  Wang 《眼科学报》1997,13(3):116-119
Purpose : To compare the clinical application value of Ultrasound biomicrsocpic dark room provocative test with the traditional dark room test in screening primary angle closure glaucoma (PACG).Methods: 22 eyes with PACG in prodromal stage and 30 eyes with deep anterior chamber and wide angle of 15 normal persons were observed in this trail. All 52 eyes were performed traditional dark room provocative test and ultrasound biomicorosopic darkroom test respectively. With different positive diagnostic criteria, the sensitivity of the two methods were compared using chi-squared analysis.Results : After staying in the dark room for 2 hours, In case group, IOP in 10 of 22 eyes rose more than 1. 07kPa(1kPa = 7.5mmHg), in 12 eyes less than 1.07kPa or had no changes; appositional angle closure were found by Goldmann gonioscopy in 8 eyes : 3 eyes in two quadrants, 5 eyes in more than two quadrants; the appositional angle closure was found by UBM in 15 eyes; 3 eyes in one quadrants, 5 eyes in two quadrants, 7 eyes  相似文献   
10.
Objective: To examine the relationship between ambient lead levels and blood lead levels and to explore the modifiers of the relationship between ambient lead and blood lead. Method: A cross-sectional study was conducted in two lead battery factories. Blood lead level and ambient lead concentration were measured for each participant concurrently. A structured questionnaire was administered to collect sociodemographic characteristics and occupational history. Design: Biological and personal environmental measurements of 219 lead-exposed workers were analyzed by both simple and multiple linear regression. A regression model was selected for interpretation. Results: A high correlation (r=0.62) between ambient lead (PbA) and blood lead (PbB) was observed. In addition, numerous factors, including age, sex, alcohol consumption, personal hygiene practice and type of lead exposure, were also found to influence blood lead levels. Although PbB was highly correlated with PbA, blood lead level may not be effectively lowered by reducing ambient lead level. Based on the regression coefficients, improvement of hygienic practice was more effective at lowering PbB than reducing ambient lead level. Good hygienic practice may be the preferential way to reduce lead exposure in current conditions. Conclusion: Education of correct work practice may be more important than engineering control in the developing countries to lower blood lead levels in lead battery factories. Received: 28 May 1996/Accepted: 30 August 1996  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-23

京公网安备 11010802026262号