全文获取类型
收费全文 | 1091篇 |
免费 | 149篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 72篇 |
妇产科学 | 17篇 |
基础医学 | 130篇 |
口腔科学 | 33篇 |
临床医学 | 164篇 |
内科学 | 221篇 |
皮肤病学 | 15篇 |
神经病学 | 157篇 |
特种医学 | 93篇 |
外科学 | 43篇 |
综合类 | 27篇 |
预防医学 | 89篇 |
眼科学 | 16篇 |
药学 | 109篇 |
肿瘤学 | 45篇 |
出版年
2023年 | 13篇 |
2022年 | 4篇 |
2021年 | 15篇 |
2020年 | 13篇 |
2019年 | 10篇 |
2018年 | 27篇 |
2017年 | 20篇 |
2016年 | 22篇 |
2015年 | 21篇 |
2014年 | 29篇 |
2013年 | 34篇 |
2012年 | 37篇 |
2011年 | 38篇 |
2010年 | 40篇 |
2009年 | 51篇 |
2008年 | 44篇 |
2007年 | 34篇 |
2006年 | 27篇 |
2005年 | 43篇 |
2004年 | 28篇 |
2003年 | 35篇 |
2002年 | 31篇 |
2001年 | 30篇 |
2000年 | 25篇 |
1999年 | 36篇 |
1998年 | 36篇 |
1997年 | 46篇 |
1996年 | 47篇 |
1995年 | 35篇 |
1994年 | 28篇 |
1993年 | 24篇 |
1992年 | 20篇 |
1991年 | 18篇 |
1990年 | 16篇 |
1989年 | 27篇 |
1988年 | 28篇 |
1987年 | 16篇 |
1986年 | 25篇 |
1985年 | 26篇 |
1984年 | 26篇 |
1983年 | 15篇 |
1982年 | 21篇 |
1981年 | 10篇 |
1980年 | 16篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1974年 | 4篇 |
1971年 | 4篇 |
排序方式: 共有1243条查询结果,搜索用时 15 毫秒
71.
A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters. 相似文献
72.
Twenty-six adolescents, aged 13–18 years, with severe congenital heart disease were matched for sex, age and living area with 26 adolescents with repaired atrial septal defect and regarded as physically fit. These two groups were compared according to somatic condition, psychopathology, psychosocial functioning and chronic family difficulties. A higher rate of psychiatric problems in the complex group, an association between psychosocial functioning and physical capacity, as well as an association between psychosocial functioning and chronic family difficulties were observed. These findings suggest that physical capacity is of crucial importance for mental health and functioning of adolescents with congenital heart disease. The association with chronic family difficulties also suggests that a comprehensive biopsychosocial approach is necessary in the treatment and rehabilitation of these patients. 相似文献
73.
PG Chatelain Kabi Pharmacia International Growth Study 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(S392):79-81
Using the database from the Kabi Pharmacia International Growth Study, 105 patients with intrauterine growth retardation (IUGR) (82 males, 23 females) and 45 with Silver-Russell syndrome (SRS) (32 males, 13 females) with persistent postnatal growth failure were studied. Patients with IUGR had a birth length and birth weight more than 2 SD below the mean for gestational age. Their height deficit at the start of GH treatment was -3.0 SDS at a median chronological age of 8.7 years and a median bone age of 7.0 years. Mean paternal and maternal heights were 166 and 153 cm, respectively. The median dose of GH was 0.5 IU/kg/week, given at a median frequency of five injections/week. The median height SDS for chronological age after 1, 2 and 3 years of GH treatment were -2.5, -2.1 and -1.9, respectively. In the 45 patients with SRS, median chronological age and median bone age at the start of treatment were 6.7 and 3.2 years, respectively, and mean paternal and maternal heights were 167.5 and 160 cm, respectively. The median dose of GH was 0.7 IU/kg/week, given at a median frequency of six injections/week. The median height SDS for chronological age at the start of treatment and after 1, 2 and 3 years were -3.5, -2.9, -2.8 and -2.2, respectively. Although the criteria used by physicians when diagnosing SRS were not controlled or verified in this study, it appears that patients with SRS can be differentiated from those with IUGR with persistent growth failure by their reduced bone age for chronological age at the start of treatment, and by the fact that patients with SRS tended to be born to parents of normal height. GH treatment in both groups induced catch-up growth, though long-term follow-up studies will be required to assess the effects of treatment on final height. 相似文献
74.
Pedersen LM Terslev L SŁrensen PG Stokholm KH 《Medical oncology (Northwood, London, England)》2000,17(2):117-122
Transcapillary escape rate of albumin was determined in 22 patients with different malignancies. In addition, urinary albumin
excretion rate was measured in 24-h urine samples using a sensitive immunoassay. Increased urinary albumin excretion was defined
as ≥20 μg/min according to conventional standards. Renal glomerular filtration and tubular function was estimated by51Cr-EDTA plasma clearance and urinary beta 2-microglobulin, respectively. Median urinary albumin excretion rate was 15.0 μg/min
(range 6–510 μg/min) and the frequency of increased urinary albumin excretion was 41%. This agrees with other studies showing
increased albuminuria in several types of malignant diseases. Patients with advanced disease (tumour, node, metastasis (TNM)
stage II–IV) had a significantly higher urinary albumin excretion rate than patients with localized disease (TNM stage I).
Serum creatinine, glomerular filtration rate and urinary beta 2-microglobulin were all within normal limits. Median transcapillary
escape rate of albumin was 5.5%/h (range 2–8%/h) and this level is comparable with values in healthy subjects. There was no
significant difference in transcapillary escape rate between patients with elevated urinary albumin excretion and the normoalbuminuric
group. Median value of the absolut outflux of albumin was 10.6 g/h with similar levels in patients with increased urinary
albumin excretion and patients with normoalbuminuria. Our results indicate a high prevalence of minor glomerular dysfunction
with a slightly elevated urinary albumin excretion in patients with malignancies. The normal endothelial function, as estimated
by the transcapillary escape rate of albumin, suggests an overal unaffected capillary permeability and increased urinary albumin
loss appears to be an isolated renal phenomenon in cancer patients. 相似文献
75.
M C Austin M Schultzberg L C Abbott P Montpied J R Evers S M Paul J N Crawley 《Brain research. Molecular brain research》1992,15(3-4):227-240
In situ hybridization histochemistry, Northern blot analysis and immunohistochemistry were used to examine tyrosine hydroxylase (TH) mRNA concentrations and immunoreactivity in the locus coeruleus and cerebellum of the tottering (tg/tg), leaner (tgla/tgla), compound heterozygous (tg/tgla) and wild type control (+/+) mice, bred on a C57BL/6J background. Cerebellar Purkinje neurons, long considered to be GABAergic, showed high levels of TH mRNA in the caudal vermis and the lateral hemispheres of the cerebellum of tg/tg, tg/tgla, and tgla/tgla mice. Analysis of grain density over individual Purkinje cells showed significantly greater concentrations of TH mRNA in tg/tg, tg/tgla, and tgla/tgla mice as compared to +/+ wild type control mice. Comparison of adult (greater than or equal to 2 months) and young, pre-seizure (less than or equal to 3 weeks) mutant mice showed Purkinje cells densely labelled for TH mRNA at both ages, suggesting that TH gene expression in Purkinje cells is independent of the onset of seizures. Northern blot analysis confirmed the findings from the in situ hybridization studies, demonstrating a single band identical to TH mRNA. Immunohistochemistry confirmed the presence of TH protein in Purkinje cells of the caudal vermis and the lateral hemispheres of the cerebellum in both control and mutant mice. Quantitation of mRNA for TH and the coexisting neuropeptide, galanin, in the locus coeruleus detected no significant differences between adult tg/tg, tg/tgla and +/+ control mice. The present findings demonstrate that the classically GABAergic Purkinje cells in the cerebellum express low levels of TH, and that the mutant tottering and leaner strains of mice express extremely high levels of mRNA and protein for TH. 相似文献
76.
Adrian P. Crawley Mark S. Cohen Ph.D. E. Kent Yucel Brigitte Poncelet Thomas J. Brady 《Cardiovascular and interventional radiology》1992,15(1):32-42
Recently developed technologies that allow the collection of magnetic resonance imaging (MRI) in as little as 26 msec have been explored in their application to angiography. Advantages are demonstrated in scan time reduction, insensitivity to patient motion (especially in abdominal applications), flow quantification, and temporal resolution. We demonstrate that because such single-shot techniques are inherently resistant to flow dephasing during acquisition that allow for sustained high signal intensities to be achieved when images must be combined through the cardiac cycle. Such high temporal resolution scans may be utilized for the collection of time-resolved angiograms. With these techniques we demonstrate the collection of complete MR angiograms in the course of reasonable 10–25 sec breath holds. The relative simplicity of the technique, coupled with its overall short acquisition time, allows us to incorporate angiography into other imaging protocols without adding significant time burdens. Results to date are promising for further improvements in spatial resolution, without extension of scan time. 相似文献
77.
78.
79.
The retention of 14C-DTPA in human volunteers after inhalation or intravenous injection 总被引:2,自引:0,他引:2
This study in human volunteers was designed to compare the retention of diethylenetriaminepentaacetic acid (DTPA) in the body after intravenous (i.v.) injection with that following inhalation by using a 14C labelled tracer. After i.v. injection retention in the blood could be described by three exponential components with half-times of about 1.4 min (approximately 60%) 14.3 min (approximately 20%) and 95 min (approximately 20%). By 24 hr more than 99% of the 14C-DTPA had been excreted in the urine and less than 0.5% remained in the plasma. After inhalation of 14C-DTPA retention in the lungs could be represented by a single component with a half time of about 75 min. As a consequence the length of time that a therapeutically useful amount of DTPA is retained in the body is approximately twice that following intravenous injection. 相似文献
80.
J N Crawley 《European journal of pharmacology》1985,112(1):129-133
A broad spectrum monoamine oxidase inhibitor, tranylcypromine sulfate (Parnate) was tested in a new hamster separation model of depression. In this paradigm, male dwarf hamsters show increases in body weight, decreases in exploratory behaviors, and decreases in social interactions, when separated from female mates. Tranylcypromine (10 mg/kg s.c. daily for 14 days) effectively reduced body weight, increased exploration, and increased social interaction, in the separated males. Subsequent treatment with saline restored the separation-induced changes in body weight, exploratory behaviors, and other social behaviors. The 'separation syndrome' in dwarf hamsters appears to be completely reversed by at least one antidepressant treatment. 相似文献