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   3798篇
  免费   215篇
  国内免费   19篇
耳鼻咽喉   21篇
儿科学   172篇
妇产科学   35篇
基础医学   482篇
口腔科学   105篇
临床医学   300篇
内科学   1014篇
皮肤病学   35篇
神经病学   176篇
特种医学   126篇
外科学   559篇
综合类   13篇
预防医学   100篇
眼科学   150篇
药学   353篇
中国医学   8篇
肿瘤学   383篇
  2023年   18篇
  2022年   29篇
  2021年   55篇
  2020年   26篇
  2019年   27篇
  2018年   69篇
  2017年   26篇
  2016年   60篇
  2015年   74篇
  2014年   75篇
  2013年   103篇
  2012年   128篇
  2011年   137篇
  2010年   100篇
  2009年   94篇
  2008年   133篇
  2007年   196篇
  2006年   178篇
  2005年   149篇
  2004年   170篇
  2003年   167篇
  2002年   143篇
  2001年   128篇
  2000年   125篇
  1999年   156篇
  1998年   117篇
  1997年   76篇
  1996年   88篇
  1995年   66篇
  1994年   57篇
  1993年   55篇
  1992年   103篇
  1991年   100篇
  1990年   93篇
  1989年   80篇
  1988年   57篇
  1987年   64篇
  1986年   68篇
  1985年   48篇
  1984年   35篇
  1983年   30篇
  1982年   20篇
  1981年   29篇
  1980年   20篇
  1979年   38篇
  1978年   23篇
  1976年   19篇
  1972年   18篇
  1971年   21篇
  1970年   18篇
排序方式: 共有4032条查询结果,搜索用时 15 毫秒
61.
Normal values of all IgG subclasses were determined using a sensitive ELISA in children aged from newborn to 14 years. The upper and lower limits of normal values of all IgG subclasses were obtained in all the age groups using 29 umbilical cord blood samples from full-term newborns and 308 venous blood samples from normal infants and children. The trends in the levels of IgG1, IgG2 and IgG3 with age were almost similar to previous reports. IgG4 levels decreased gradually until reaching the lowest level at 7 to 12 months and increased gradually with age, reaching a plateau at 12 to 14 years of age. Thus, the lower limit of serum IgG4 levels was determined using our method.  相似文献   
62.
In a case with chronic pancreatitis and pseudocysts related to muscular cytochrome—c oxidase deficiency, endoscopic ultrasonography (EUS) was performed to morphologically examine the pancreas for features that may have been missed by abdominal computed tomography and pancreatography. Conventional abdominal sonography had failed to show valuable diagnostic information of chronic pancreatitis in this case. EUS demonstrated several new findings. Parenchymal atrophy was remarkable, especially in the pancreatic tail, and a dilated pancreatic main or branch duct was clearly found in the region. Moreover, pancreatic stones in the main duct were also distinctly proved. EUS may become a useful new diagnostic method in pediatric gastroenterology, especially when sufficient findings are not obtained by conventional imaging techniques. However, an ultrasonographic endoscope with a shorter rigid portion and smaller caliber should be developed for pediatric patients.  相似文献   
63.
Two girls with acute lymphocytic leukemia (ALL) are reported. There were difficulties in removing their central venous catheters inserted from a peripheral vein. One girl required surgery under general anesthesia for the removal. The other patient received continuous infusion of low dose urokinase from a distal peripheral vein. The residual catheter was then removed successfully.  相似文献   
64.
Recent research has suggested that an association exists between moyamoya disease and fibromuscular dysplasia which involves systemic vessels, including renal arteries. We report a 3 year old girl with moyamoya disease associated with bilateral renal artery stenosis. This case may support the common etiology of these two clinical conditions. To our knowledge this is the youngest case of moyamoya disease associated with bilateral renal artery stenosis.  相似文献   
65.
Antibodies of Epstein-Barr virus (EBV), EBV-specific cytotoxic T lymphocyte (EBVCTL) activity and the lymphocyte subset of CTL were examined in 13 Japanese children with chronic active EBV infection (CAEBV) and their parents (eight fathers and 10 mothers). Anti-virus-capsid antigen (VCA)-IgG antibody titers ranged from 1: 640 to 1: 5120 in the patients with CAEBV and from 1: 40 to 1: 640 in the parents. While anti-VCA-IgM antibody was detected in three patients, anti-VCA-IgA antibody in five and anti-early-antigen (EA)-IgG antibody in 11, no antibody was detected in the parents except anti-EA antibody, which was positive in the mothers of cases 5 and 13 (1: 10 and 1: 40). Anti-EBV-associated nuclear antigen (EBNA) antibody was ≥ 1: 10 in six out of 13 patients with CAEBV and in 10 out of 18 parents tested. Epstein-Barr virus activity was significantly lower (P < 0.005) both in the children with CAEBV and in their parents than in seropositive age-matched controls. Proportions of a CTL subset (CD8+ CD11? lymphocytes) in the patients with CAEBV were significantly higher (P< 0.005) than in controls, while those in the parents were at the same level as in controls. Defective EBVCTL activity and anti-EBNA-antibody responses were frequently observed both in children with CAEBV and in their parents, which may suggest that the abnormal immune response to EBV may be based on a familial disorder, though no familial involvement has been reported in Japanese children with CAEBV.  相似文献   
66.
The purpose of this study was to determine whether pulmonary hemodynamic abnormalities relate to manifestations of allergic asthma. In 448 patients with congenital heart disease the relationships between asthma and age or pulmonary arterial blood (PA) flow were studied. Asthma (allergic and non-allergic) was more common in 39 (19%) of 201 patients with high PA flow, compared with the incidence in those with normal PA flow (6/117, 5%; P < 0.001) and reduced PA flow (1/130, 1%; P < 0.05). In the high PA flow group, the frequency of asthma declined significantly (P < 0.01) with age, from 25–26% in the 6 month-5 year patient group to 5% in the 6–12 year old patients. The frequency of asthma, including allergic type, was significantly (P < 0.01) greater in patients with pulmonary hypertension (15/24, 63%) than in those without (10/77, 13%) at the age of 6 months to 1 year. Asthma in the high PA flow group was associated with other allergic diseases in 30 (77%) of 39 patients, including food allergy in nine (23%), atopic dermatitis in 14 (36%), allergic rhinitis in seven (18%) and abnormally high total IgE levels in 14 (36%). These findings suggest that high pulmonary flow or pulmonary hypertension enhances the manifestation of allergic disease, particularly asthma.  相似文献   
67.
Although percutaneous transluminal balloon aortic valvuloplasty (PTAV) has been performed for congenital aortic stenosis in infants and children for several years, its efficacy and the associated aortic regurgitation (AR) have not been widely discussed. Percutaneous transluminal balloon aortic valvuloplasty using an Inoue balloon catheter was performed for congenital aortic stenosis in 12 patients (4–16 years old) in this study. The systolic aortic valve pressure gradient ranged from 42 to 111 mmHg before PTAV and became < 50 mmHg immediately after PTAV in 10 cases (83%). Eight of these 10 patients had no increase in the gradient during subsequent observation for a period of 9–40 months. Aortic regurgitation increased immediately after PTAV in nine cases (75%). It increased from grade 1 to grade 2 in eight cases and from grade 1 to grade 3 in one patient; no significant enlargement of the left ventricular end-diastolic diameter and no significant change in the left ventricular end-diastolic pressure (LVEDP) or the cardiac index was observed during follow-up in these patients. There was a correlation between the diameter of the balloon and efficacy; an appropriate diameter was considered to be about 90% of the aortic annular diameter. Changes in the hemodynamic parameter after PTAV with an Inoue balloon were small in most patients and this procedure is considered to be a treatment that should be attempted prior to surgery for congenital aortic stenosis.  相似文献   
68.
To observe the secular trend of a proportion of Kawasaki disease patients with cardiac sequelae in Japan, we analyzed patients with Kawasaki disease reported to nationwide surveys of the disease during 10.5 years from July 1982 to December 1992. Of 69 382 patients reported to the surveys, 10 596 (15.3%) were reported to have cardiac sequelae such as dilatation or stenosis of coronary arteries, myocardial infarction or valvar lesions, 1 month or more after onset. The percentage of cardiac sequelae was particularly high in males, infants younger than 1 year and children older than 5 years of age. The overall prevalence declined steadily over the observed period. However, the percentage for children older than 5 years of age did not decrease, whether treated with intravenous gamma globulin or untreated. As a consequence of the increased number of patients treated with intravenous gamma globulin, the proportion of Kawasaki disease patients with cardiac sequelae decreased annually. However, the proportion of children older than 5 years of age did not decrease.  相似文献   
69.
An epidemiological survey was carried out to examine the present situation with respect to sudden infant death syndrome (SIDS) in Kanagawa Prefecture. Questionnaires on sudden unexpected death of infants aged < 1 year in 1990-91 were sent to the hospitals and clinics in Kanagawa Prefecture which may take care of such infants. By analysing information from 10 485 replies, 48 out of 73 reported sudden infant deaths were confirmed to be SIDS, although autopsy was not performed in 13 cases (27%). The incidence of SIDS per 1000 live births in Kanagawa Prefecture was 0.29 in 1990 and 0.31 in 1991; and if limited to autopsy cases 0.19 and 0.25, respectively. Sudden infant death syndrome cases in Japan were found to occur more frequently when infants were < 6 months old, at home and sleeping alone, but less in the winter and between midnight and early morning. There was little difference between the numbers in prone and supine sleeping positions at discovery. It was not clear whether SIDS occurred more often to babies sleeping prone than supine, because there were no controls matched with the SIDS cases. In future, continuous epidemiological surveys of SIDS in Japan should be carried out.  相似文献   
70.
A case report is presented of a 15-year-old girl with reflex sympathetic dystrophy (RSD). She was referred to hospital because of left upper limb pain. Her left upper limb was cold, edematous and blue with a limited active range of movement. The serum concentration of noradrenaline was lower on the painful side than on the healthy side, and neurotropin, which has an antinociceptive effect to hyperalgesia, was clearly effective. Early diagnosis and management is essential in the treatment of RSD and administration of neurotropin is a useful and non-invasive treatment without severe adverse effects.  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