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   350篇
  免费   7篇
  国内免费   11篇
儿科学   44篇
妇产科学   6篇
基础医学   16篇
口腔科学   5篇
临床医学   24篇
内科学   78篇
皮肤病学   3篇
神经病学   6篇
特种医学   75篇
外科学   19篇
综合类   5篇
预防医学   37篇
眼科学   3篇
药学   16篇
  2篇
中国医学   2篇
肿瘤学   27篇
  2021年   3篇
  2020年   2篇
  2019年   2篇
  2018年   4篇
  2017年   2篇
  2016年   3篇
  2015年   6篇
  2014年   8篇
  2013年   8篇
  2012年   5篇
  2011年   6篇
  2010年   11篇
  2009年   10篇
  2008年   4篇
  2007年   15篇
  2006年   9篇
  2005年   11篇
  2004年   12篇
  2003年   7篇
  2002年   10篇
  2001年   8篇
  2000年   3篇
  1999年   5篇
  1998年   20篇
  1997年   17篇
  1996年   15篇
  1995年   11篇
  1994年   14篇
  1993年   10篇
  1992年   4篇
  1991年   2篇
  1990年   2篇
  1989年   15篇
  1988年   13篇
  1987年   8篇
  1986年   8篇
  1985年   6篇
  1984年   7篇
  1983年   5篇
  1982年   7篇
  1981年   8篇
  1980年   6篇
  1979年   3篇
  1978年   2篇
  1977年   3篇
  1976年   8篇
  1975年   7篇
  1974年   3篇
  1973年   2篇
  1972年   6篇
排序方式: 共有368条查询结果,搜索用时 15 毫秒
361.
BACKGROUND: The collection of adequate numbers of neutrophils (polymorphonuclear leukocytes, PMNs) from normal donors has long hampered the development of neutrophil transfusion therapy. The stimulation of donors with granulocyte-colony-stimulating factor (G- CSF) plus dexamethasone is a promising way of improving PMN collections. STUDY DESIGN AND METHODS: Sixteen normal subjects received G-CSF (600 micrograms subcutaneously) and dexamethasone (8 mg by mouth) 12 hours before leukapheresis. Measurements included PMN morphology, immunophenotype analysis, chemiluminescence, bactericidal activity, in vivo kinetics, and adverse effects. RESULTS: A mean of 77.4 +/− 6.4 × 10(9) PMNs was collected with each leukapheresis; 14 percent were bands. PMNs had increased surface expression of CD11b, CD18, CD14, CD32, and CD64. Bactericidal capacity against Staphylococcus aureus was normal. Inducible respiratory burst was maintained, although the responses to some agonists were diminished. Returned leukapheresis cells labeled with 3H-diisopropylfluorophosphate had a modestly decreased percentage of recovery and circulated with a prolonged half- life. Migration of these cells to skin chambers was approximately equal to that of the subjects' own blood PMNs. Adverse effects included transient bone pain, headache, hunger, and insomnia. CONCLUSIONS: Precollection treatment of leukapheresis donors with G-CSF plus dexamethasone is an effective way to enhance the collection of PMNs with normal or near-normal functional properties for PMN transfusion therapy.  相似文献   
362.
PURPOSE: Commonly used behavioral and electrical testing methods for estimation of visual acuity and visual function in infants yield different estimates and may not accurately predict visual acuity and visual function in later life. Moreover, neither test-retest variability nor side-by-side comparisons of the various methods have been thoroughly evaluated in the same infant population. The purpose of this study was to provide such an evaluation. METHOD: The test-retest variability of visual acuity and visual function was evaluated for the Teller Acuity Card (TAC) procedure, sweep visual evoked potential (VEP), as well as latency and amplitude measured by transient pattern VEP. Groups of approximately 20 infants contributed test-retest data. Visual function estimated by the various methods in a larger group of infants (n = 118) was compared. Correlations between methods and the validity of the various methods to detect maturational changes between 4 and 8 months of age were also assessed. Administration of these tests was according to standard and usual procedures. RESULTS: The average percent difference between test and retest estimates of acuity as well as the SD was lowest for transient VEP latency (3%, 7% SD). The other methods were markedly more variable: sweep VEP (2%, 22% SD), TAC procedure (8%, 20% SD), and transient VEP amplitude (7.5%, 39% SD). Average coefficients of variation showed a similar trend: transient VEP latency, 8%; sweep VEP, 15%; TACs, 30%; and transient amplitude, 53%. Correlations among estimates by the methods were poor, but expected changes in visual maturation from 4 to 8 months of age were detected with all methods. CONCLUSIONS: All methods evaluated provide valid and reliable test-retest data for a group, but are less valid for estimating visual acuity and visual function of an individual subject. The poor correlations between any 2 of the testing methods suggest that each test assesses a different aspect of vision. Nonetheless, expected maturational changes between 4 and 8 months of age were readily detectable by all methods evaluated.  相似文献   
363.
Chan  WC; Check  I; Schick  C; Brynes  RK; Kateley  J; Winton  EF 《Blood》1984,63(5):1133-1140
We report four patients with expansion of a unique population of lymphocytes that is consistently associated with neutropenia. Two patients also had rheumatoid arthritis and autoantibodies. The lymphocytes contained many cytoplasmic azurophilic granules, which possessed strong acid phosphatase activity. Multiple cytoplasmic parallel tubular arrays were observed ultrastructurally. These granular lymphocytes showed the T suppressor/cytotoxic cell phenotype (E+, OKT3+, OKT8+, OKT4-, OKM1-, OKI1-) and exhibited antibody-dependent cell-mediated cytotoxic activity but little or no natural killer cytotoxicity. They did not respond to recall antigens, concanavalin A, or pokeweed mitogen, but the cells from one patient did respond to phytohemagglutinin. No in vitro suppressor cell activity on mitogenic responses of allogeneic cells and on mixed lymphocyte cultures could be demonstrated. There was no evidence of suppression of immunoglobulin synthesis in vivo. It is uncertain that the expansion of this subset of lymphocytes represents a leukemic process. Their constant association with neutropenia, however, raises the possibility that the increase in large granular lymphocytes and neutropenia might be pathogenetically related.  相似文献   
364.

BACKGROUND:

The seroprevalences of hepatitis B virus (HBV) and hepatitis C virus (HCV) are 0.4% and 0.8%, respectively, in Canada, but varying rates have been reported in different populations.

OBJECTIVES:

To determine the seroprevalences of HBV and HCV among attendees of an Asian health fair in the Lower Mainland, British Columbia, as well as to correlate questionnaire answers regarding vaccination status to serological profiles.

METHODS:

Attendees at an Asian health fair were invited to participate in the present study on a voluntary basis. They provided answers to a questionnaire including ethnicity and vaccination status. Blood was then drawn for HBV and HCV serology. Active HBV was defined as HBV surface antigen (HBsAg) positive while HCV seroprevalence was defined as HCV antibody reactive. Previous exposure to HBV was defined as HBV core antibody (anti-HBc) positive and HBsAg negative. Nonimmunity was defined as anti-HBc negative and HBV surface antibody negative. Only those with correct demographic information matched to serological results were included in the study.

RESULTS:

There were 192 consenting attendees of the fair, of whom 112 were included in the study. Of the participants, 91% were Chinese. Active HBV infection was found in three participants (2.7% [95% CI 0.6% to 7.6%]) and HCV infection was found in two participants (1.8% [95% CI 0.2% to 6.3%]). More than 40% of participants had been previously exposed to HBV (42% [95% CI 33% to 51%]). Almost 20% demonstrated nonimmunity to HBV (19% [95% CI 12% to 27%]). There was significant discordance when questionnaire answers regarding vaccination status were compared with serological profiles.

CONCLUSION:

The seroprevalences of HBV and HCV in this cohort were 2.7% and 1.8%, respectively – higher than nationally reported rates. Our results highlight that the lack of knowledge of HBV infection and vaccination status remains a significant clinical issue in the Asian community of British Columbia.  相似文献   
365.
366.
367.
Rosacea fulminans is a rare disease with female predominance characterized by abrupt onset of pustules, papules, and confluent nodules on the face. The conventional treatment consists of systemic glucocorticoids and isotretinoin. We present the case of a 56-year-old woman with a marked facial papulopustular eruption that had followed an initial period of severe seborrhoea. Conventional treatment produced no clear improvement. Dapsone treatment achieved complete healing in 5 weeks.  相似文献   
368.
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