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   1755篇
  免费   105篇
  国内免费   12篇
耳鼻咽喉   12篇
儿科学   113篇
妇产科学   14篇
基础医学   165篇
口腔科学   102篇
临床医学   193篇
内科学   294篇
皮肤病学   39篇
神经病学   131篇
特种医学   334篇
外科学   151篇
综合类   13篇
预防医学   142篇
眼科学   38篇
药学   57篇
肿瘤学   74篇
  2023年   5篇
  2022年   5篇
  2021年   14篇
  2020年   11篇
  2019年   12篇
  2018年   21篇
  2017年   9篇
  2016年   15篇
  2015年   30篇
  2014年   31篇
  2013年   39篇
  2012年   51篇
  2011年   46篇
  2010年   55篇
  2009年   46篇
  2008年   51篇
  2007年   68篇
  2006年   47篇
  2005年   50篇
  2004年   62篇
  2003年   44篇
  2002年   34篇
  2001年   29篇
  2000年   33篇
  1999年   48篇
  1998年   111篇
  1997年   81篇
  1996年   81篇
  1995年   61篇
  1994年   65篇
  1993年   68篇
  1992年   28篇
  1991年   20篇
  1990年   25篇
  1989年   49篇
  1988年   40篇
  1987年   56篇
  1986年   32篇
  1985年   34篇
  1984年   25篇
  1983年   22篇
  1982年   26篇
  1981年   24篇
  1980年   34篇
  1979年   13篇
  1978年   26篇
  1977年   20篇
  1976年   21篇
  1975年   15篇
  1916年   4篇
排序方式: 共有1872条查询结果,搜索用时 15 毫秒
1.
Needle-localized breast biopsy: why do we fail?   总被引:10,自引:0,他引:10  
Jackman  RJ; Marzoni  FA  Jr 《Radiology》1997,204(3):677
  相似文献   
2.
Case-adjusted prospective reimbursement systems, such as resource utilization groups (RUGs), may promote nursing home cost containment, but they may do no better than existing systems at encouraging homes to admit the more dependent and thus costlier Medicaid patients, if the homes' reluctance to admit these patients is due to a shortage of nursing home beds. Using 1983 data on Wisconsin nursing homes, this paper presents evidence that suggests that the presence of excess demand, rather than low reimbursement rates, causes nursing homes to exclude the more costly Medicaid patients. Consequently, to benefit fully from RUGs, it is necessary either to eliminate excess demand (by increasing supply or decreasing demand) or to decide which patients have priority for admission and assign reimbursement payments to these patients that significantly favor these patients. Otherwise, access to nursing home care under RUGs is left to chance.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
3.
Calcifying epithelial odontogenic tumor (CEOT) is a benign, locally aggressive odontogenic neoplasm characterized by sheets and nests of epithelial cells with deeply eosinophilic or occasionally clear cytoplasm, calcifications, and eosinophilic amorphous material that stains positive for amyloid. Although many cases of CEOT are associated with impacted teeth and occasionally appear radiographically as dentigerous cysts, a true cystic variant has not been previously reported. We report a 15-year-old white male with a large cystic maxillary lesion that filled most of the left maxillary sinus. It deformed the medial wall, the inferior orbital floor, and caused narrowing of the left inferior meatus. Histologically, the cystic lining showed characteristics of CEOT. An intraluminal component that featured histologic characteristics of CEOT was identified during surgery. The lesion was enucleated and the postsurgical course of the patient was uneventful. Because follow-up has been for less than 1 year, a meaningful long-term prognosis cannot be determined at present. However, the patient has not reported any symptoms or signs of recurrence during the follow-up period.  相似文献   
4.
Monitoring the performance of the health care delivery system is a public health function that becomes more important as organized delivery systems begin to take control over larger portions of the medical care market. The study reported here illustrates how standard medical care epidemiology can be applied to analysis of health care system performance to aid governmental efforts to monitor new developments in the medical care market. In order to evaluate the efficiency of hospital care delivered in Iowa, age- and sex-adjusted population admission rates for five common procedures were generated for all 99 counties. The five common procedures were defined as follows: hernia, tonsillectomy, cesarean section, hysterectomy, and cholecystectomy. In addition, variations in 11 ambulatory care-sensitive condition rates were analyzed. Residents of at least 15 counties were at significantly greater than average risk of receiving each of the common procedures (chi 2 test, P < 0.05). Counties that had a high rate for one procedure tended to have a high rate for at least one other procedure. Several counties had more than twice the mean rate. Even a 10% reduction, when added across all five common procedures. amounts to well over 2,000 hospitalizations avoided. It is assumed that reductions would be concentrated in high-rate counties. If a 50% reduction could be achieved in only part of the ambulatory care-sensitive procedures, more than 10,000 hospital admissions could be avoided.  相似文献   
5.
6.
7.
荧光原位杂交技术分析人结肠菌群方法研究   总被引:2,自引:0,他引:2  
建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。  相似文献   
8.
9.
10.
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