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   1493557篇
  免费   121862篇
  国内免费   3491篇
耳鼻咽喉   19116篇
儿科学   48975篇
妇产科学   42840篇
基础医学   213828篇
口腔科学   40169篇
临床医学   133462篇
内科学   301061篇
皮肤病学   34609篇
神经病学   125212篇
特种医学   57296篇
外国民族医学   473篇
外科学   221019篇
综合类   33113篇
现状与发展   4篇
一般理论   565篇
预防医学   120309篇
眼科学   32953篇
药学   103808篇
  1篇
中国医学   3541篇
肿瘤学   86556篇
  2021年   12225篇
  2019年   13048篇
  2018年   18299篇
  2017年   14129篇
  2016年   15883篇
  2015年   17819篇
  2014年   25054篇
  2013年   36624篇
  2012年   50546篇
  2011年   53098篇
  2010年   30877篇
  2009年   29847篇
  2008年   48931篇
  2007年   51533篇
  2006年   51902篇
  2005年   50141篇
  2004年   47406篇
  2003年   45139篇
  2002年   43319篇
  2001年   75694篇
  2000年   77240篇
  1999年   63998篇
  1998年   18101篇
  1997年   16339篇
  1996年   16490篇
  1995年   15535篇
  1994年   14117篇
  1993年   13204篇
  1992年   47551篇
  1991年   45046篇
  1990年   42993篇
  1989年   40999篇
  1988年   37516篇
  1987年   36505篇
  1986年   33948篇
  1985年   32332篇
  1984年   24609篇
  1983年   20703篇
  1982年   12589篇
  1981年   11116篇
  1979年   21336篇
  1978年   14959篇
  1977年   12398篇
  1976年   11622篇
  1975年   11888篇
  1974年   14322篇
  1973年   13873篇
  1972年   12920篇
  1971年   11760篇
  1970年   11136篇
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
991.
The role of body temperature in the morbidity and mortality resulting from acute severe carbon monoxide (CO) poisoning (2400 ppm CO, 90 min) was investigated using an unanesthetized animal model. Modified Levine prepared female rats (left common carotid artery and jugular cannulated) displayed a lower rate of recovery period (4 hr) re-warming, and an increased mortality rate and behaviorally-assessed neurologic index (NI) compared to normal rats. This indicated their greater susceptibility to CO hypoxia, although the degree of CO-induced hypothermia was the same in both groups. The whole-body cooling of Levine rats to a similar extent prior to CO exposure increased somewhat the post-CO re-warming rate, and marginally decreased NI and mortality during CO exposure (in-CO). In contrast, maintenance of constant body temperature by external heating during CO exposure resulted in a negative post-CO re-warming rate and sharply increased NI and in-CO mortality. Normal euthermic rats were much less severely affected by CO. The results suggest that hypothermia, whether CO-induced or produced by prior cooling, provides measurable protection of brain function during acute severe CO poisoning, and that maintenance of body temperature increases in-CO mortality and interferes with ability to thermoregulate and increases NI in survivors.  相似文献   
992.
The epidemiology of viral hepatitis in US Navy enlisted personnel was reviewed for the years 1975-1984. Hospital discharge summaries of all active duty enlisted personnel admitted to a US Navy treatment facility were used for the study. From 1975 to 1984, total first hospitalizations for viral hepatitis declined from 128 per 100,000 personnel (95% confidence interval (Cl) 118-139) to 56 per 100,000 personnel (95% Cl 50-63). The highest incidence of acute viral hepatitis (115 per 100,000 personnel) was found in the youngest age groups aged 24 years and less. Risk factors for acute hepatitis included a previous hospitalization with either drug abuse (relative risk = 363) or a sexually transmitted disease (relative risk = 25) listed among the discharge diagnoses. Having a medical job classification was also associated with an increased risk of acute hepatitis. The steep decline in the incidence of viral hepatitis during this 10-year period may have been due to decreasing drug abuse in the US Navy. Immunization of high-risk groups in the US Navy with hepatitis B vaccine could be an effective policy for the prevention of acute viral hepatitis.  相似文献   
993.
Knowledge of the health status of, and patterns of health care service utilization by rural Australian communities, is scant. This deficiency limits attempts to formulate policies designed to bring about efficient, effective and equitable delivery of health care services. This article reports the results of a health interview survey conducted in the Wimmera region of Victoria during spring 1984. The results demonstrate not only that patterns of morbidity in rural areas differ from the Australian average, but also that the health status of rural dwellers is worse than that of most Australians. Evidence suggests that while accessibility is not the most significant determinant of utilization of health care services, distance from services does affect propensity to use them.  相似文献   
994.
We describe an improved synthesis and properties of fluphenazine-mustard, a potent phenothiazine having an alkylating chlorethylamine chain in its structure. The drug possesses anticalmodulin activity equivalent to the parent compound, but unlike fluphenazine dihydrochloride, the mustard derivative irreversibly antagonizes the ability of calmodulin to activate cyclic nucleotide phosphodiesterase. This property is partially calcium-dependent and can be overcome by coincubation with excess fluphenazine dihydrochloride. The compound irreversibly inactivated calmodulin when incubated with intact cells and caused single-stranded breakage of DNA. Fluphenazine-mustard possesses potent antiproliferative and cytotoxic properties against malignant cell lines that are likely to be mediated through both of these actions.  相似文献   
995.
996.
997.
Long-term dialysis patients frequently develop acquired renal cystic disease (ARCD). The discovery of ARCD and renal cell carcinoma in one of our hemodialysis patients led us to review the literature. ARCD has been described mainly in the maintenance hemodialysis (MH) population. Therefore, we investigated 20 peritoneal dialysis (PD) patients for ARCD using ultrasonography. Seven patients (35%) had detectable cysts and two patients (10%) had multiple bilateral cysts. One patient had a large asymptomatic complex cyst that proved to be an adenocarcinoma. Our study suggests that ARCD is relatively common in the PD population, and we speculate that it may be related more to length of time in end-stage renal disease (ESRD) than to the mode of dialysis. The potential for malignant change appears to justify a routine screening examination with ultrasonography and/or computerized tomography (CT) to detect this recently described and probably underrecognized entity.  相似文献   
998.
999.
Modern medicine has made many advances in the capability to sustain life. The dental profession needs to keep up to date with these changes and be creative in caring for these individuals who are medically compromised and who require special care.11 This sometimes requires the purchase of new equipment; other times it means modifying that which exists. In all instances, the level of care for these individuals requires a team approach and mandates education of all team members. In the case presented, the medical problems necessitated such a team effort to achieve optimal care.  相似文献   
1000.
Renal magnesium wasting in two families with autosomal dominant inheritance   总被引:3,自引:0,他引:3  
Hypomagnesemia due to isolated renal magnesium loss was demonstrated in two unrelated families with autosomal dominant mode of inheritance. Magnesium infusions performed in two patients showed not only a reduced renal magnesium threshold but also a lowered renal tubular maximum for magnesium. All members of both families who presented with hypomagnesemia had also a lowered excretion of calcium in the urine, presumably as a consequence of increased reabsorption in Henle's loop.  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