首页 | 官方网站   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   194篇
  免费   5篇
医药卫生   199篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   2篇
  2016年   4篇
  2015年   2篇
  2014年   6篇
  2013年   8篇
  2012年   5篇
  2011年   3篇
  2010年   6篇
  2009年   6篇
  2008年   6篇
  2007年   11篇
  2006年   13篇
  2005年   7篇
  2004年   14篇
  2003年   10篇
  2002年   7篇
  2001年   7篇
  2000年   6篇
  1999年   4篇
  1998年   1篇
  1994年   1篇
  1993年   2篇
  1992年   4篇
  1991年   12篇
  1990年   7篇
  1989年   2篇
  1988年   5篇
  1987年   8篇
  1986年   3篇
  1985年   2篇
  1984年   2篇
  1981年   1篇
  1979年   2篇
  1977年   4篇
  1973年   1篇
  1970年   2篇
  1969年   3篇
  1963年   1篇
  1940年   1篇
  1939年   1篇
  1926年   1篇
排序方式: 共有199条查询结果,搜索用时 15 毫秒
1.
Influenza A was cultured in 62 double rooms. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (CI95, 1.61-5.78) of acquiring influenza.  相似文献   
2.
The Assessment of Living Skills and Resources (ALSAR), an innovative instrumental activities of daily living tool, systematically evaluates the accomplishment of 11 tasks by separately rating patient skill and resource levels for each task and combining these levels to determine risk. The ALSAR was administered to 75 elderly veterans in a home care program. It predicted change to more supportive living arrangements and a more structured living environment, nursing home placement, hospitalization, and death during the 6-month study period. The ALSAR has proven useful for interdisciplinary problem solving and treatment planning.  相似文献   
3.
4.
Acute (50.0 mg/kg) and repeated (0.1–10.0 mg/kg) administration of dihydroergosine (DHESN) to rats over 5 days lowered the concentration of 5-HIAA in the brain. DHESN given acutely increased the brain 5-HT in p-CPA-treated animals and diminished the probenecid-induced increase in brain 5-HIAA. In pargyline-treated rats DHESN enhanced the 5-HT/5-HIAA ratio. DHESN administered to rats repeatedly over 5 days decreased the level of 5-HT in blood platelets, and in vitro at concentrations of 10-4 M and 10-3 M inhibited the uptake of [14C]-5-HT in platelets. DHESN (10.0–100.0 mg/kg) potentiated the 5-HT syndrome produced in rats by pargyline and 5-HTP. This potentiation was blocked with cyproheptadine but not with haloperidol. DHESN (1.0 and 10.0 mg/kg) lowered the locomotor activity of rats and 10.0 mg/kg DHESN also reduced the duration of immobility in rats forced to swim in a restricted space. The results indicate that DHESN, like antidepressants, decreases the turnover of serotonin in the brain and potentiates the 5-HT-mediated behaviour. This might suggest that the drug should be further investigated for its potential antidepressive properties.  相似文献   
5.
6.
Influenza remains a major cause of illness and death in elderly people despite current vaccination programs. One factor is an immunization failure rate in the elderly that may be as high as 50%. To test whether administration of thymosin alpha 1 would result in greater antibody production, we administered it (900 micrograms/m2 subcutaneously twice weekly for eight doses) in conjunction with the 1986 trivalent influenza vaccine. Ninety men (65-99 years old, mean age 77.3 years) were randomized double-blind to receive thymosin alpha 1 or placebo by the same schedule; the sera from 85 of these men were acceptable for analysis. The two groups were similar with respect to underlying disease, medications, and age. No toxicity was observed in either group. Antibody response rate was defined as a four-fold rise in antibody titer over 3-6 weeks following vaccination and was measured by an enzyme-linked immunosorbent assay (ELISA). Analysis was performed on treatment groups and subgroups divided by the mean age: the older group consisted of subjects aged 77 years and older, and the younger group those aged from 65-76 years. Baseline and change in absolute antibody levels were compared by t test and using age as a continuous variable by multiple regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
7.

Objective

To investigate genetic subtypes of inherited bone marrow failure syndrome Fanconi anemia (FA) in Sebia. FA-D2 subtype was found to be the most frequent genetic subtype among investigated FA patients; specific observations of FA-D2 phenotype are pointed out.

Methods

Several biological endpoints of FA cells in vitro such as radiation-induced level of lymphocyte micronuclei (radiosensitivity), base line and radiation induced level of the DNA double strand breaks (DSBs), leukocyte apoptosis, and telomere capping function were assessed.

Results

The results indicate that all FA-D2 patients display radioresistant in vitro response, which is seen as significantly reduced yield of radiation-induced micronuclei. On the contrary, FA-A patients display radiosensitive in vitro response seen as increased number of radiation-induced micronuclei (MN). A massive elimination of irradiated cells via apoptosis is found in both FA-A and FA-D2 subtypes. In FA-A subtype apoptosis positively relates with the yield of radiation-induced MN, whereas in FA-D2 subtype apoptosis relates with a high percentage of cells carrying dysfunctional telomeres. The present results unequivocally demonstrate that cytokinesis-block micronucleus (CBMN) assay and analyses of telomere capping function can be used to distinguish FA-D2 and FA-A complementation groups.

Conclusions

Considering all biological endpoints were analyzed, it can be concluded that all FA patients are radiosensitive, regardless of their complementation group. Thus, using CBMN test and telomere capping function analysis can discriminate FA-A from FA-D2 complementation groups, which could be important for assessment the conditioning regimens prior to bone marrow transplantation.  相似文献   
8.

Objectives

Nonspecific signs and symptoms combined with positive urinalysis results frequently trigger antibiotic therapy in frail older adults. However, there is limited evidence about which signs and symptoms indicate urinary tract infection (UTI) in this population. We aimed to find consensus among an international expert panel on which signs and symptoms, commonly attributed to UTI, should and should not lead to antibiotic prescribing in frail older adults, and to integrate these findings into a decision tool for the empiric treatment of suspected UTI in this population.

Design

A Delphi consensus procedure.

Setting and Participants

An international panel of practitioners recognized as experts in the field of UTI in frail older patients.

Measures

In 4 questionnaire rounds, the panel (1) evaluated the likelihood that individual signs and symptoms are caused by UTI, (2) indicated whether they would prescribe antibiotics empirically for combinations of signs and symptoms, and (3) provided feedback on a draft decision tool.

Results

Experts agreed that the majority of nonspecific signs and symptoms should be evaluated for other causes instead of being attributed to UTI and that urinalysis should not influence treatment decisions unless both nitrite and leukocyte esterase are negative. These and other findings were incorporated into a decision tool for the empiric treatment for suspected UTI in frail older adults with and without an indwelling urinary catheter.

Conclusions

A decision tool for suspected UTI in frail older adults was developed based on consensus among an international expert panel. Studies are needed to evaluate whether this decision tool is effective in reaching its aim: the improvement of diagnostic evaluation and treatment for suspected UTI in frail older adults.  相似文献   
9.
In humans, usual aging, differently from successful aging, is associated with deregulation of proinflammatory/anti-inflammatory cytokine balance. The corresponding data from rat studies are limited. Therefore, we examined (i) cytokine messenger RNA (mRNA) profile of fresh peritoneal cells from 6- (adult), 24- (old), and 31-month-old (long-lived) AO rats and (ii) proinflammatory (IL-1β and IL-6) and anti-inflammatory (IL-10) cytokine, NO, and urea production in their LPS-stimulated cultures. Comparing with adult rats, cells from old ones expressed lower amount of TNF-α and IL-6 mRNAs, but greater amount of IL-1β mRNA. On the other hand, cells from long-lived rats exhibited a dramatic increase in IL-10 mRNA expression followed by diminished TNF-α and IL-6 mRNA expression, and comparable expression of IL-1β mRNA relative to adult rats. Consequently, IL-10/IL-1β mRNA ratio was greater in cells from long-lived rats than in adult and old rats. In LPS-stimulated peritoneal cell cultures (contained ≥95 % macrophages) from old rats, concentration of common proinflammatory cytokines was higher than in those from adult rats. Comparing with adult and old rats, in LPS-stimulated macrophage cultures from long-lived rats, TNF-α and IL-6 concentrations were lower; IL-1β concentration was comparable or greater (in respect to adult rats), whereas that of IL-10 was strikingly higher. Consistently, in macrophage cultures from long-lived rats, NO (iNOS activity marker)/urea (arginase activity marker) ratio was less and not different from that in old and adult rats, respectively. The study suggests that macrophages from long-lived rats, differently from those of old ones, have substantial ability to limit proinflammatory mediator production, which may contribute to their longevity.  相似文献   
10.
OBJECTIVE: To identify delayed prophylaxis from a pre-existing database and strategies to improve performance. SETTING: A skilled nursing facility with 14 floors (4 buildings). The "outbreak unit" was a 50- to 60-bed floor. METHODS: We performed surveillance during six seasons using one protocol. Prophylaxis was started when influenza was cultured in the building and 10% of residents on the floor had a new respiratory illness within 7 days. We defined delayed prophylaxis as four or more residents on a floor with positive cultures whose specimens had been collected within 5 days before the application of prophylaxis. RESULTS: We identified 14 examples of delayed prophylaxis. In three, delayed prophylaxis was related to the 3.9-day delay between culture collection and culture report There was a high degree of commonality among building attack rates within a season. During six seasons, the first case in the last building occurred 27 to 64 days after the first case in the facility. The two seasons with the greatest activity (68 and 154 cases, respectively) began with explosive, multi-floor outbreaks in a single building. The match between the circulating strain and the vaccine was good, except in 1997-1998 when there were seven examples of delayed prophylaxis. CONCLUSIONS: Influenza may involve buildings sequentially with a commonality of building attack rates. Explosive, multi-floor outbreaks early in the season could lead to a lower threshold for prophylaxis within a larger area when initial cases are encountered later in the season. This strategy could have prevented five examples of delayed prophylaxis. Rapid testing of multiple specimens while waiting for culture confirmation could have prevented three examples of delayed prophylaxis.  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-23

京公网安备 11010802026262号