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   418篇
  免费   32篇
  国内免费   2篇
儿科学   49篇
妇产科学   2篇
基础医学   43篇
口腔科学   27篇
临床医学   38篇
内科学   102篇
皮肤病学   5篇
神经病学   14篇
特种医学   36篇
外科学   34篇
综合类   8篇
预防医学   32篇
药学   16篇
中国医学   1篇
肿瘤学   45篇
  2023年   2篇
  2021年   5篇
  2020年   2篇
  2019年   2篇
  2018年   5篇
  2017年   12篇
  2016年   11篇
  2015年   7篇
  2014年   14篇
  2013年   27篇
  2012年   10篇
  2011年   23篇
  2010年   9篇
  2009年   12篇
  2008年   11篇
  2007年   21篇
  2006年   18篇
  2005年   15篇
  2004年   16篇
  2003年   13篇
  2002年   9篇
  2001年   22篇
  2000年   11篇
  1999年   11篇
  1998年   9篇
  1997年   9篇
  1996年   6篇
  1995年   5篇
  1994年   4篇
  1993年   4篇
  1992年   15篇
  1991年   8篇
  1990年   5篇
  1989年   10篇
  1988年   11篇
  1987年   10篇
  1986年   12篇
  1985年   6篇
  1984年   4篇
  1983年   6篇
  1982年   6篇
  1981年   4篇
  1980年   2篇
  1979年   6篇
  1978年   3篇
  1977年   2篇
  1976年   4篇
  1973年   3篇
  1971年   4篇
  1969年   2篇
排序方式: 共有452条查询结果,搜索用时 0 毫秒
421.
Pancreatic cancer is a disease with a very poor prognosis and its etiology is still largely elusive. The only consistent environmental risk factor is cigarette smoking. A previous history of pancreatitis or diabetes mellitus is also considered to be a risk factor. Epidemiological studies have confirmed that relatives of those with pancreatic cancer have an increased risk of this malignancy, and it has been evaluated that 3-5% of all pancreatic cancer cases are caused by genetic predisposition to the disease. Usually this occurs in the setting of a known inherited cancer syndrome caused by mutations in genes such as BRCA1/2 and CDKN2A. Whether or not a true site-specific pancreatic adenocarcinoma syndrome exists is not known. The real challenge for the management of high risk patients is to develop new screening methods than can identify pre-neoplastic or early neoplastic lesions in a timely manner.  相似文献   
422.
Aluminum bone disease is a frequent complication of dialysis patients. The deferoxamine (DFO) test has been advocated as a noninvasive procedure for the diagnosis of AI bone lesion. However most of these studies have been performed in symptomatic patients with significant AI bone disease. Whether this test may provide similar data at an earlier stage of AI toxicity is not known. The present study evaluates prospectively 28 patients with mild AI load. Patients studied ranged in age from 21 to 65 years; duration of dialysis was 5.6 +/- 3.2 years; deferoxamine, 40 mg/kg body weight, was infused at the end of dialysis. Serum AI was measured before DFO administration and before the next dialysis treatment. Bone biopsies were performed in all patients. Cortical bone AI was determined biochemically; trabecular and cortical bone AI were also determined histochemically. Mean basal serum AI (43.2 +/- 30.8 micrograms/L) and cortical bone AI (25.7 +/- 35.2 micrograms/g) were moderately increased. Basal serum AI correlated (r = 0.77) with the increment in serum AI after DFO infusion. After DFO, stainable trabecular and cortical bone AI correlated in a similar manner with both basal serum AI and increment in serum AI. Only biochemically determined cortical bone AI was not significantly related to basal serum AI. Nineteen of the 28 patients had evidence of osteitis fibrosa on bone biopsy. Stained AI surfaces but not trabecular AI were different in patients with low and patients with high bone formation rates. The bone findings, assessed as bone formation rates and resorption surfaces, did not correlate with biochemically or histochemically determined bone AI.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
423.
The authors describe the principle of inductively coupled argon plasma emission spectrometry (ICP) to determine inorganic compounds in biological samples. This method is compared with more classical electrothermal flame atomisation absorption spectrometry. The association of ICP with different instruments is reminded (HPLC, mass spectrometry, graphite furnace, hybride generation). Finally, the review ends with some applications in biological fluids.  相似文献   
424.
Newborn ferrets were inoculated with Mink Enteritis virus (parvovirus). They developed a cerebellar hypoplasia and presented severe ataxia. Electrophysiological study by intracellular recordings in the cerebellar cortex demonstrates that in these ferrets, like in other mammals, Purkinje cells deprived from granule cell input during development remain multiply innervated by climbing fibers in the adult.  相似文献   
425.
We describe a 21-year-old patient who experienced a relapse of cutaneous gnathostomiasis after receiving initial treatment with albendazole and who had a successful outcome after receiving a short course of ivermectin for the relapse. This is the first reported case of gnathostomiasis acquired by a human in Peru.  相似文献   
426.
427.
Twelve children were diagnosed as having a bleeding Meckel diverticulum upon laparotomy. Before surgery, barium small bowel examination was performed according to the Bret technique (J Radiol Paris [1980] 61, 753-758) in 8 cases; the Meckel diverticulum being apparent in all 8 cases. By contrast, a classical technique of barium small bowel examination used in 4 cases, and 99m TC pertechnate scan performed in 7 cases, yielded only negative results. We conclude that barium small bowel examination, when performed according to the Bret's technique, is a very effective method for the diagnosis of Meckel diverticulum.  相似文献   
428.
429.
All 107 infants weighing ≤1500 g at birth (VLBW) and born alive in the south-east region of Sweden during a 15-month period in 1987-88 were enrolled in a prospective study to determine the prevalence of handicap and to assess neurological function in comparison with controls. Eighty-six (80%) infants survived. Twenty (19%) had intracranial haemorrhages (ICH) assessed by ultrasound examinations in the neonatal period and 2 (2.3%) retinopathy of prematurity stage 3 or more. The VLBW infants who survived had fewer optimal neurological responses than the controls at 40 weeks post-conceptional age. Eighty-two VLBW children were followed to 4y of age. Three (4%) children had a neurological handicap and 9 (11%) had a moderate neurological deviation. Neither the size of ICH nor neonatal optimality score correlated to neurological outcome at 4 y of age. The VLBW children without neurological handicap or deviation (n = 70) had a delay in psychomotor development in comparison with the controls. Mental development and school performance, in particular language development, will be examined at school age.  相似文献   
430.
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