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   2964篇
  免费   206篇
  国内免费   14篇
耳鼻咽喉   107篇
儿科学   144篇
妇产科学   36篇
基础医学   348篇
口腔科学   62篇
临床医学   270篇
内科学   643篇
皮肤病学   40篇
神经病学   287篇
特种医学   206篇
外科学   395篇
综合类   48篇
预防医学   243篇
眼科学   60篇
药学   144篇
中国医学   11篇
肿瘤学   140篇
  2023年   12篇
  2022年   37篇
  2021年   42篇
  2020年   30篇
  2019年   58篇
  2018年   87篇
  2017年   70篇
  2016年   57篇
  2015年   65篇
  2014年   96篇
  2013年   118篇
  2012年   139篇
  2011年   146篇
  2010年   91篇
  2009年   75篇
  2008年   135篇
  2007年   136篇
  2006年   137篇
  2005年   121篇
  2004年   96篇
  2003年   117篇
  2002年   99篇
  2001年   105篇
  2000年   101篇
  1999年   102篇
  1998年   56篇
  1997年   56篇
  1996年   63篇
  1995年   55篇
  1994年   45篇
  1993年   30篇
  1992年   41篇
  1991年   48篇
  1990年   33篇
  1989年   42篇
  1988年   43篇
  1987年   53篇
  1986年   53篇
  1985年   36篇
  1984年   26篇
  1983年   27篇
  1982年   15篇
  1981年   18篇
  1980年   12篇
  1979年   17篇
  1977年   14篇
  1976年   22篇
  1975年   11篇
  1974年   12篇
  1973年   11篇
排序方式: 共有3184条查询结果,搜索用时 15 毫秒
1.
2.
3.
Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.  相似文献   
4.
5.
Orthotopic liver transplantation was performed in 20 pigs. Serum total bile acids (STBA) were determined and their profile compared with standard early function parameters: total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactic acid. In phase I, the STBA level was 32.89 +/- 1.29 mumol/l. In phase II, STBA accumulated to 84.46 +/- 15.25 mumol/l (p less than 0.01), followed by hepatic clearance in phase III (63.61 +/- 9.71 mumol/1; NS). Between phase III and 6- and 12-hour samples, STBA decreased progressively, reaching values of 33.63 +/- 7.05 mumol/l at 24 h. AST was elevated in phases I, II, III, and at 6, 12 and 24 h (p less than 0.001), as was ALT (but with insignificant differences). Thus, STBA and their profile appear to be earlier and more specific indicators of early graft function than conventional parameters.  相似文献   
6.
7.
A 57 year old patient presented with unilateral diaphragmatic paralysis and severe hypoxaemia secondary to transient right-to-left interatrial shunting through a patent foramen ovale. The final diagnosis was made because of the initial detection of a shunt while the patient was breathing 100% oxygen.  相似文献   
8.
New markers have been used to monitor the changes of bone turnover occurring during growth. Data on bone turnover rate during the perinatal period are, however, very scarce. In the present study we evaluated bone turnover rate, assessed by the measurement of urinary N-terminal telopeptide of type I collagen (NTx) concentrations, at different gestational ages, and we documented the trend of bone turnover rate occurring in the first days after birth. Urine samples were obtained from 83 healthy full term newborn infants, 16 preterm, and 17 infants of diabetic mothers (IDMs). The first miction after birth was collected. Urine samples were also collected 24 and 48 h after birth. NTx was measured by an enzyme-linked immunosorbent assay (Osteomark®, Ostex International, Inc. Seattle, WA). The relationship between NTx at birth and all the other variables has been evaluated using multiple regression analysis. The changes of NTx excretion over time and the effect of the groups were studied by multivariate analysis of variance (MANOVA) for repeated measures. We found a remarkable association between gestational age and NTx concentrations at birth (R = 0.56; p < 0.00001). NTx concentrations showed a progressive decrement, reaching a nadir between the 38th and the 42nd week of gestation. The NTx concentrations changed significantly during the first 48 h of life in the three groups. Moreover, preterm infants had NTx excretion values at birth significantly higher than full term infants (p < 0.001), whereas NTx excretion rates of IDMs were not different from those of the other two groups of subjects. In conclusion, gestational age seems to be the major determinant of bone turnover in neonates; NTx excretion rate is higher before term, it slows in proximity of delivery, and it increases significantly during the first 48 h of life. Preterm infants have higher bone turnover rate than full term infants. NTx excretion rate of IDMs was comparable with those of the control subjects.  相似文献   
9.
目的:对临床确诊糖尿病患同时测定血清葡萄糖(Glu)及糖化血清蛋白(GSP)的含量,观察二的关系,以及糖化血清蛋白水平对于评价近期(2—3周)糖尿病患血糖在体内变化的临床意义进行了观察。方法:血清葡萄糖、糖化血清蛋白测定均采用酶法测定。结果:178例糖尿病患Glu、GSP均正常3l例占17.4%;Glu、GSP均增高107例占60.1%;Glu正常、GSP增高15例占8.43%;Glu增高、GSP正常25例占14%。结论:糖化血清蛋白的含量不受即时血糖的影响,二的变化不成比例性,对评价糖尿病患2~3周病情的控制是一项灵敏可靠的指标,尤其对于住院病人的治疗与监控有一定的意义。  相似文献   
10.
We studied seven examples of the solid variant of adenoid cystic carcinoma of the uterine cervix in postmenopausal women who presented with vaginal bleeding and a large ulcerated or polypoid cervical mass. The tumors lacked the characteristic cribriform pattern of conventional adenoid cystic carcinoma. The neoplastic cells were small, undifferentiated, or basaloid and grew in cords, nests, trabeculae, and nodules. Foci of squamous cell carcinoma were seen in three tumors and areas of necrosis in four. A characteristic feature was the production of abundant periodic acid-Schiff's procedure (PAS)-positive basement membrane material that was immunoreactive for collagen IV and that in some areas compressed tumor cells. Electron microscopy on three cases showed globules and cylinders of redundant basal lamina. The tumor cells were joined by desmosomes and contained bundles of tonofilaments. Material similar to basement membrane material appeared to be intracytoplasmic in two tumors. No neurosecretory granules or myoepithelial cells were found. Four deaths were tumor related. Two patients are currently alive, but with local recurrence or metastases; another is alive and well 19 months after surgery. We believe that the solid variant of adenoid cystic carcinoma of the cervix is a distinctive neoplasm that should be separated from small cell carcinomas with or without endocrine features, adenoid basal cell carcinoma, and squamous cell carcinoma.  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