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   369022篇
  免费   9447篇
  国内免费   428篇
耳鼻咽喉   3644篇
儿科学   12675篇
妇产科学   7647篇
基础医学   44143篇
口腔科学   7342篇
临床医学   25844篇
内科学   72505篇
皮肤病学   5796篇
神经病学   32629篇
特种医学   13561篇
外国民族医学   1篇
外科学   50965篇
综合类   3272篇
一般理论   68篇
预防医学   41105篇
眼科学   7610篇
药学   24282篇
中国医学   1333篇
肿瘤学   24475篇
  2023年   1165篇
  2022年   1107篇
  2021年   3546篇
  2020年   2142篇
  2019年   3821篇
  2018年   27384篇
  2017年   20727篇
  2016年   22987篇
  2015年   5285篇
  2014年   5910篇
  2013年   8538篇
  2012年   19623篇
  2011年   33946篇
  2010年   25090篇
  2009年   16338篇
  2008年   29626篇
  2007年   32471篇
  2006年   11381篇
  2005年   12525篇
  2004年   12941篇
  2003年   13201篇
  2002年   10956篇
  2001年   5469篇
  2000年   6178篇
  1999年   4638篇
  1998年   1220篇
  1997年   900篇
  1992年   2405篇
  1991年   2208篇
  1990年   2220篇
  1989年   1876篇
  1988年   1748篇
  1987年   1635篇
  1986年   1681篇
  1985年   1586篇
  1984年   1161篇
  1983年   1007篇
  1979年   1290篇
  1978年   873篇
  1977年   839篇
  1975年   958篇
  1974年   1209篇
  1973年   1243篇
  1972年   1176篇
  1971年   1134篇
  1970年   1091篇
  1969年   1153篇
  1968年   1192篇
  1967年   1041篇
  1966年   930篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
81.
82.
BACKGROUND: The role of large colony streptococci groups C or G as pathogen agents in sore throat has been questioned. AIM: To analyse clinical features of patients with large colony streptococci groups C or G compared with patients with group A streptococci (GAS) and with negative cultures. DESIGN OF STUDY: Prospective study of patients with sore throat. SETTING: Two Norwegian general practices in Stokke and Kongsberg communities with 6500 patients.METHOD: Frequency of clinical features in the three patient categories including the four Centor criteria (fever, anterior cervical lymphadenopathy, tonsillar exudates, and lack of cough), degree of pain on swallowing, pharyngeal rubor, C-reactive protein (CRP) values, patient age between 3 and 14 years, and duration of symptoms before seeing the doctor. A logistic regression analysis to find independent predictors was performed. RESULTS: Out of 306 patients with a sore throat, 244 were adults and 62 were children under 10 years old; 40% were men. One hundred and twenty-seven had GAS, 33 had streptococci groups C or G, and 146 had negative throat cultures. Forty-eight per cent of the GAS patients and 45% of the C or G patients met three or four of the Centor criteria. The logistic regression revealed that in patients with GAS considerable pain on swallowing, an age of 3-14 years and a duration of symptoms of < or =3 days or less were significantly associated with GAS infection in addition to the Centor criteria. The same results were found when all streptococci were analysed together, in addition elevated CRP was significant. In patients with streptococci group C or G an elevated CRP-value was significantly associated. CONCLUSION: Patients with tonsillitis caused by streptococcus groups C or G have, to a large extent, the same clinical picture as patients with GAS. Large colony streptococci groups C and G should be considered as throat pathogens in line with GAS.  相似文献   
83.
M Balázs  G Vadász  I Koncz  E Simon 《Orvosi hetilap》1991,132(39):2143-2146
15 patients with congestive gastropathy were reported including clinical and pathological characteristics of the disease. Every patient had alcoholic liver cirrhosis and portal hypertension. 6 patient's stomach was resected while in 2 further cases the disease was found at autopsy. In additional 7 cases the characteristic microvascular changes were observed in endoscopic biopsy specimens from the gastric mucosa. The authors presume that this disease has an acute and a chronic stage. In the acute stage dilated capillaries are present under the surface, not related to the inflammation of gastric mucosa. This phenomenon was described in the literature. In the chronic stage there are dilated and tortuous vessels in the submucosal layer surrounded by collagenous connective tissue. The authors suppose that the thick and fibrotic submucosal layer causes microcirculatory disturbances in the gastric mucosa. The impaired microcirculation may cause extensive ulcers with profuse and sometimes lethal bleeding.  相似文献   
84.
85.
Stuttering and tetanic syndrome   总被引:1,自引:0,他引:1  
  相似文献   
86.
The hepatic circulation of patients with hilar carcinoma and icterus was studied by isotope technique. A marked alternation in blood flow was observed, that is that the ratio of the circulation of the hepatic artery and the portal vein became balanced. By elimination of the icterus, the hepatic circulation normalized. This allowed the conclusion that the change in blood flow must have rather been due to the mechanical icterus and the increased pressure of the bile duct than to the tumorous infiltration and therefore the earliest possible elimination of the icterus is urgently indicated.  相似文献   
87.
This paper studies all cases affected by 5 parotiditis from January to September 1986 (1767 cases) and 1987 (124 cases), as well as all patients with rubella reported in the same period in 1986 (584 cases) and 1987 (5 cases) in the province of Pinar del Río. The rise in the incidence of the two diseases with an annual basis per 100,000 population during 1986 in the different municipalities is emphasized. The overtly downward trend of these two diseases in 1987 after the administration of the triple viral vaccine--93% for mumps and 99.15% for rubella--is discussed. It was found that these two diseases affected more often school children (5-14 years). It was found that these two diseases are not frequent under the first year of life (76.4 and 120.1 cases per 100,000 population respectively). The percentage of vaccine effectiveness was documented--97.4% for parotiditis and 100% for rubella.  相似文献   
88.
The different types of instruments used for monitoring pharmaceutical dissolution testing are presented. Their features and the need for automation are critically discussed. The advantages of flow injection analysis in this respect are illustrated by a variety of examples clearly showing its adaptability to the different problems posed by other automatic and non-automatic alternatives.  相似文献   
89.
90.
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