全文获取类型
收费全文 | 1142篇 |
免费 | 74篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 87篇 |
妇产科学 | 36篇 |
基础医学 | 113篇 |
口腔科学 | 25篇 |
临床医学 | 142篇 |
内科学 | 229篇 |
皮肤病学 | 20篇 |
神经病学 | 24篇 |
特种医学 | 308篇 |
外科学 | 66篇 |
综合类 | 19篇 |
预防医学 | 49篇 |
眼科学 | 16篇 |
药学 | 30篇 |
中国医学 | 1篇 |
肿瘤学 | 60篇 |
出版年
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 14篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 23篇 |
2012年 | 12篇 |
2011年 | 14篇 |
2010年 | 29篇 |
2009年 | 26篇 |
2008年 | 16篇 |
2007年 | 33篇 |
2006年 | 22篇 |
2005年 | 32篇 |
2004年 | 29篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 26篇 |
1998年 | 97篇 |
1997年 | 69篇 |
1996年 | 76篇 |
1995年 | 52篇 |
1994年 | 54篇 |
1993年 | 61篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 14篇 |
1989年 | 44篇 |
1988年 | 25篇 |
1987年 | 43篇 |
1986年 | 27篇 |
1985年 | 30篇 |
1984年 | 27篇 |
1983年 | 21篇 |
1982年 | 23篇 |
1981年 | 23篇 |
1980年 | 28篇 |
1979年 | 12篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 21篇 |
1975年 | 13篇 |
1974年 | 4篇 |
1970年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有1227条查询结果,搜索用时 15 毫秒
111.
112.
Benzie AA Bansi LK Sabin CA Portsmouth S Hill T Johnson M Gilson R Easterbrook P Gazzard B Fisher M Orkin C Dunn D Delpech V Taylor GP Walsh JC Phillips AN;United Kingdom Collaborative HIV Cohort 《AIDS (London, England)》2007,21(11):1423-1430
OBJECTIVE: We investigated whether the rate of viral rebound decreases with increasing duration of viral suppression and, if so, whether rebound rates in patients previously failing antiretroviral regimens ultimately decline to levels as low as those seen in patients who have never experienced virological failure. METHODS: All patients from the UK CHIC Study (n = 21 256) who achieved a viral load (VL) of < or = 50 copies/ml while receiving HAART were followed until viral rebound (two consecutive VL > 400 copies/ml). Patients could re-enter the analysis if they experienced a subsequent VL < or = 50 copies/ml. Rebound rates were calculated according to the number of regimens previously failed and duration of viral suppression. RESULTS: Of 12 648 patients on HAART 10 237 (80.9%) achieved a VL < or = 50 copies/ml. During 26 494 person-years (PY) of follow-up, 1853 (18.1%) patients experienced at least one viral rebound 'event', with 2460 events in total [rebound rate, 9.3 (range, 8.9-9.7)/100 PY). Within the first year of viral suppression, the rate of viral rebound was 8.3 (7.5-9.1)/100 PY in patients who had not previously failed treatment, increasing to 32.7 (27.6-37.8)/100 PY in patients who had failed more than four regimens. Irrespective of previous treatment failure, rebound rates in those who remained suppressed for > 4 years were similar to those in patients who had at no time experienced treatment failure. CONCLUSION: After around 4 years of viral suppression rebound rates in individuals with multiple prior treatment failures approach those of individuals with no prior treatment failure. 相似文献
113.
We measured red blood cell iron incorporation (RBC-inc) in 13 human milk-fed premature infants (birthweight 1037 +/- 289 g, gestational age 27 +/- 2 wk, weight at start of study 1571 +/- 426 g) who were receiving full tube-feedings of human milk fortified with a commercial human milk fortifier (FortHM). The relative RBC-inc of supplemental iron (2 mg/kg/d of ferrous sulfate) was assessed using 57Fe sulfate mixed directly into a 24-h volume of FortHM, and 54Fe sulfate given as a bolus between two FortHM feedings the next day. RBC-inc was similar between the two methods of supplemental iron administration (4.7 +/- 2.5% vs 4.6 +/- 1.5%, respectively). Although these values are lower than RBC-inc expected from iron native to human milk, the relatively large amount of iron in the supplements contributed most of the iron incorporated into RBC by the infants. There was a significant positive correlation between the reticulocyte count and RBC-inc. As the high nutrient (especially calcium) content of the FortHM did not interfere with iron utilization, adding iron directly to FortHM, or incorporating it into commercial fortifiers, may be a practical method to provide iron to premature infants. 相似文献
114.
W Oh DK Stevenson JE Tyson BH Morris CE Ahlfors G Jesse Bender RJ Wong R Perritt BR Vohr KP Van Meurs HJ Vreman A Das DL Phelps T Michael O’Shea RD Higgins 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(5):673-678
Objectives: To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18–22 months corrected age in extremely low birth weight infants. Method: Total plasma bilirubin and unbound bilirubin were measured in 1101 extremely low birth weight infants at 5 ± 1 days of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18–22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow‐up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors. Results: Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow‐up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow‐up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants. Conclusions: In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma bilirubin and death or adverse neurodevelopmental outcomes at 18–22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants. 相似文献
115.
RJ Livingston JW Butterworth P Belt 《Annals of the Royal College of Surgeons of England》2013,95(1):e20-e21
Chloramphenicol is a topical treatment that is used widely, especially in wounds around the eyes. In our practice there have been a number of cases of delayed hypersensitivity to chloramphenicol that has been mismanaged initially as an infective cellulitis. We hope to share some of our experience of this uncommon reaction to highlight the delayed reaction that can occur with topical application of this drug. 相似文献
116.
117.
MA Ben-Gashir† PT Seed‡ RJ Hay† 《Journal of the European Academy of Dermatology and Venereology》2002,16(5):455-462
BACKGROUND: Atopic dermatitis (AD) can be traumatizing to family life. Little is known about the relationship between quality of life in AD and disease severity. OBJECTIVE: To document family quality of life and relate this to severity of AD in children, for a 6-month period from a given point in time. STUDY DESIGN: These data are part of a longitudinal study conducted in two parts of the UK to investigate risk factors for AD severity and its impact on quality of life. SUBJECTS: and methods Thetargetedpopulation comprised children with AD aged 5-10 years in a primary-care setting. The general practitioners identified potential subjects and the UK diagnostic criteria for AD were used to verify the diagnosis. Both the children and their parents were interviewed. Eczema severity was assessed using a modified form of the SCORAD (SCORe Atopic Dermatitis) Index (SCORAD-D) from which parents' score of itching and sleep loss were excluded. The quality of family life was quantified by the Dermatitis Family Impact (DFI) questionnaire. These two parameters were evaluated on two occasions 6 months apart. ANALYSIS: Multiple regression analysis was used to investigate the relationship between the quality of family life and the severity of the AD in the children, at a specific point in time and over the following 6-month period. RESULTS: Of the 116 children attending the first visit, mean age 8 years, 106 attended the second visit (91%) and were included in the analysis. Quality of family life was shown to be significantly affected in 48 (45%) cases at the first visit and 38 (36%) cases at the second visit. The initial means of the DFI and SCORAD-D were 2.4 and 8.2, respectively. Six months later the mean final DFI and SCORAD-D were 1.9 and 7.7, respectively. Using multiple regression on the first and second visits, each unit increase in SCORAD-D was associated with 0.21 [95% confidence interval (CI) 0.06-0.37 P = 0.008] and 0.37 (95% CI 0.15-0.59, P = 0.001) units increase in quality of family life, respectively. This relationship remained significant even after adjustment for potential confounders (black skin, social class, sex, child's age, family size and location) each unit increase in SCORAD-D led to a 0.25 unit (95% CI 0.11-0.4, P = 0.001) and 0.23 unit (95% CI 0.05-0.42, P = 0.014) increase in DFI on the first and second visits, respectively. Changes in the DFI scores were significantly related to changes in the SCORAD-D scores (regression coefficient; 0.17 (95% CI 0.06-0.29, P = 0.002). CONCLUSIONS: We show that quality of family life is related to the severity of AD in children. This confirms the importance of parental assessment of the impact of the disease in the management of AD, because the disease affects the entire family. Also, these results show the response of DFI to change predictably with disease severity. This may imply that the DFI questionnaire could be used as an extra measure of outcome in everyday clinical practice as well as in research studies. 相似文献
118.
119.
120.
Modulation of implantation-associated integrin expression but not uteroglobin by steroid hormones in an endometrial cell line 总被引:2,自引:0,他引:2
Widra EA; Weeraratna A; Stepp MA; Stillman RJ; Patierno SR 《Molecular human reproduction》1997,3(7):563-568
In order to test the hypothesis that integrin and uteroglobin (UG)
expression in cultured endometrial cells are affected by hormone treatment,
Ishikawa-CH endometrial cancer cells were cultured and exposed to
oestradiol or oestradiol and progesterone regimens and assayed using
immunohistochemistry. We evaluated the intensity of immunohistochemical
staining for the integrin monomers alpha(v) and beta1, the dimers
alpha(v)beta3 and alpha(v)beta6, and for the secretory protein uteroglobin
under various experimental conditions. Cells grown in control media stained
positively for the integrin monomers alpha(v) and beta1, the dimer
alpha(v)beta3, and for UG. Oestradiol and sequential
oestradiol/progesterone reversibly suppressed staining for the dimer
alpha(v)beta3. Hormone treatment had no effect on the staining of the beta1
and alpha(v) monomers or UG. The alpha(v)beta6 dimer antibody did not stain
under any experimental treatment conditions. These data indicate that
expression of the integrin complex alpha(v)beta3 is reversibly suppressed
by oestradiol in Ishikawa cells and that these cells may be a good model
for studying hormone-driven molecular changes in endometrium.
相似文献