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   1264011篇
  免费   94641篇
  国内免费   1578篇
耳鼻咽喉   16313篇
儿科学   41003篇
妇产科学   34950篇
基础医学   189390篇
口腔科学   34735篇
临床医学   117753篇
内科学   247794篇
皮肤病学   27279篇
神经病学   101855篇
特种医学   46758篇
外国民族医学   265篇
外科学   178584篇
综合类   25749篇
现状与发展   3篇
一般理论   568篇
预防医学   104649篇
眼科学   28048篇
药学   92555篇
  6篇
中国医学   2022篇
肿瘤学   69951篇
  2018年   13530篇
  2017年   10392篇
  2016年   11325篇
  2015年   13080篇
  2014年   17999篇
  2013年   27479篇
  2012年   37581篇
  2011年   39970篇
  2010年   23055篇
  2009年   22250篇
  2008年   37755篇
  2007年   40385篇
  2006年   39964篇
  2005年   39096篇
  2004年   37543篇
  2003年   35953篇
  2002年   34864篇
  2001年   56029篇
  2000年   57042篇
  1999年   48095篇
  1998年   13396篇
  1997年   12222篇
  1996年   12644篇
  1995年   11914篇
  1994年   11107篇
  1993年   10399篇
  1992年   38199篇
  1991年   37671篇
  1990年   36445篇
  1989年   35258篇
  1988年   32692篇
  1987年   32027篇
  1986年   30524篇
  1985年   28786篇
  1984年   21941篇
  1983年   19192篇
  1982年   11364篇
  1981年   10321篇
  1979年   20944篇
  1978年   15393篇
  1977年   12790篇
  1976年   11845篇
  1975年   12810篇
  1974年   15588篇
  1973年   15362篇
  1972年   14512篇
  1971年   13552篇
  1970年   12786篇
  1969年   12065篇
  1968年   11229篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
891.
Priapism: a refined approach to diagnosis and treatment   总被引:4,自引:0,他引:4  
The recent introduction of intracorporeal injections of papaverine and phentolamine for the diagnosis and treatment of impotence has resulted in an increased incidence of iatrogenic priapism. Based on our research into penile hemodynamics we propose a refined approach to all types of priapism. Intracorporeal blood gas and pressure monitoring should be used to differentiate ischemic (low flow) from nonischemic (high flow) types. Most cases of papaverine-induced or phentolamine-induced priapism will respond to aspiration alone or in combination with intracorporeal instillation of a diluted alpha-adrenergic agent. In spontaneous priapism alpha-adrenergic agents can be tried first if patients have only mild or no ischemia. In patients with severe ischemia stagnant blood should be evacuated and a shunt procedure should be performed to allow metabolic replenishment of tissue. Intracorporeal pressure monitoring will help to determine the size and number of shunts needed to re-establish corporeal circulation.  相似文献   
892.
The administration to mice of 1-methyl-4-(2'-methylphenyl)-1,2,3, 6-tetrahydropyridine (2'-CH3-MPTP), a substituted analog of the dopaminergic neurotoxin MPTP caused even more dopaminergic toxicity than MPTP itself. Under conditions in which MPTP was relatively ineffective (i.e. two injections per day of 0.113 mmol/kg at an interval of 6 h for one or two days), 2'-CH3-MPTP caused a very large decrement in the neostriatal content of dopamine and its metabolites and a corresponding decrement in the capacity of a neostriatal synaptosomal preparation to take up [3H]dopamine. Moreover, 2'-CH3-MPTP administration (as few as four injections) caused a virtually complete loss of nerve cells in the zona compacta of the substantia nigra. This compound, like MPTP, may prove to be a valuable research tool.  相似文献   
893.
894.
PURPOSE: Educational interventions to reduce the use of abbreviations and dosage designations that were deemed unsafe at a level 1 trauma center are described. SUMMARY: Strategies to reduce the use of unsafe abbreviations at Detroit Receiving Hospital were studied. Six abbreviations and dosage designations were deemed as unsafe by the site's medication-use and patient medical safety committees: (1) U for units, (2) microg for microgram, (3) TIW for three times a week, (4) the degree symbol for hour, (5) trailing zeros after a decimal point, and (6) the lack of leading zeros before a decimal point. Data on abbreviation use was collected starting in September 2003 by examining copies of patients' order sheets, which are sent from nursing units to the pharmacy for processing. Data were collected during three 24-hour periods each month, with 7-10 days between each period. A data collection sheet was developed to assist in documenting the number of opportunities for each unsafe abbreviation and the actual incidence of each. Educational strategies were developed and implemented starting in October 2003 to decrease the use of the unsafe abbreviations. These strategies included inservice education programs for the medical, pharmacy, and nursing staffs; laminated pocket cards; patient chart dividers; stickers; and interventions by pharmacists and nurses during medication prescribing. During the eight-month evaluation period, 20,160 orders were reviewed, representing 27,663 opportunities to use a designated unsafe abbreviation. Educational interventions successfully reduced the overall incidence of unsafe abbreviations from 19.69% to 3.31%. CONCLUSION: Educational interventions markedly reduced the use of unsafe abbreviations in medication orders over an eight-month evaluation period.  相似文献   
895.
896.
Immunity against the opportunistic fungal pathogen Pneumocystis.   总被引:2,自引:0,他引:2  
Species of the genus Pneumocystis exist as opportunistic fungal pathogens and are associated with severe pneumonia and pulmonary complications in immunocompromised individuals. Although prophylactic therapy for Pneumocystis has significantly decreased the overall incidence of infection, more than 80% of cases in current patient populations are considered breakthrough cases. In the HIV-infected population, in the years following the initiation of highly active antiretroviral therapy (HAART), significant reductions in the incidence of Pneumocystis infection were observed, although trends over the last several years suggest that the incidence of Pneumocystis has plateaued rather than decreased. Furthermore, with the more prominent usage of immunosuppressive therapies, the frequency of Pneumocystis infection in the HIV-negative population, such as those with hematologic malignancies and those who have undergone transplantation, has risen significantly. Investigating host defense mechanisms against P. carinii has historically been problematic due to the difficulty in achieving continuous in vitro propagation of proliferating Pneumocytis organisms. Nevertheless, clinical and experimental studies have documented that host defense against Pneumocystis involves a concerted effort between innate, cell-mediated (T lymphocyte) and humoral (B lymphocyte) responses. However, the pulmonary environment is a tissue site where heightened inflammatory responses can often lead to inflammation-mediated injury, thereby contributing to the pathogenesis of Pneumocystis infection. Accordingly, clearance of Pneumocystis from the pulmonary environment is dependent on a delicate equilibrium between the inflammatory response and immune-mediated clearance of the organism. Furthermore, innate and adaptive responses against Pneumocystis are strikingly similar to those against other medically-important fungi, thus providing additional evidence that Pneumocystis exists as a fungal organism.  相似文献   
897.
BACKGROUND: The impact of exercise programmes for heart failure on those close to the patient is largely unknown. We examined the effect of a hospital and home-based exercise intervention on burden, anxiety and depression of informal caregivers. DESIGN: The study was a randomized, controlled trial. Heart failure patients were randomized to a seated 12-week hospital-based exercise programme. Caregiver measures were gathered at baseline, 3 months later and 6 months following baseline. METHODS: Sixty caregivers (mean age 63.4 years, 65% female) of heart failure patients (n = 82, mean age 80.5 years, 44% female) participating in a trial of an exercise intervention were recruited. Caregiver burden, anxiety and depression were assessed. RESULTS: There were no differences in caregiver burden, depression or anxiety between the two groups of caregivers at baseline (caregiver burden, patient control 33.1 versus patient exercise 34.1; anxiety 4.1 versus 5.5; depression 2.8 versus 3.8). At 3 months there were no differences between caregivers in the two groups on outcomes. At 6-month follow-up caregivers of heart failure patients in the exercise group had burden scores that were significantly worse than the control group. There were no differences between the carers of exercise and control groups in anxiety and depression. Levels of anxiety and depression in the entire carer sample were marginally higher than reference values in a healthy non-clinical sample. CONCLUSION: The present exercise interventions for frail older patients did not benefit caregivers and was associated with an increase in caregiver burden. We suggest that future exercise interventions for heart failure patients should actively incorporate informal caregivers into research designs.  相似文献   
898.
899.
The drug addict     
  相似文献   
900.
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