全文获取类型
收费全文 | 6436篇 |
免费 | 708篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 191篇 |
妇产科学 | 118篇 |
基础医学 | 1038篇 |
口腔科学 | 148篇 |
临床医学 | 740篇 |
内科学 | 1014篇 |
皮肤病学 | 479篇 |
神经病学 | 535篇 |
特种医学 | 396篇 |
外科学 | 748篇 |
综合类 | 116篇 |
预防医学 | 612篇 |
眼科学 | 86篇 |
药学 | 551篇 |
中国医学 | 4篇 |
肿瘤学 | 319篇 |
出版年
2022年 | 57篇 |
2021年 | 94篇 |
2020年 | 86篇 |
2019年 | 112篇 |
2018年 | 127篇 |
2017年 | 108篇 |
2016年 | 100篇 |
2015年 | 113篇 |
2014年 | 145篇 |
2013年 | 188篇 |
2012年 | 260篇 |
2011年 | 282篇 |
2010年 | 163篇 |
2009年 | 180篇 |
2008年 | 266篇 |
2007年 | 289篇 |
2006年 | 290篇 |
2005年 | 311篇 |
2004年 | 260篇 |
2003年 | 253篇 |
2002年 | 230篇 |
2001年 | 224篇 |
2000年 | 235篇 |
1999年 | 204篇 |
1998年 | 117篇 |
1997年 | 105篇 |
1996年 | 88篇 |
1995年 | 92篇 |
1994年 | 60篇 |
1993年 | 63篇 |
1992年 | 155篇 |
1991年 | 146篇 |
1990年 | 139篇 |
1989年 | 140篇 |
1988年 | 127篇 |
1987年 | 131篇 |
1986年 | 104篇 |
1985年 | 105篇 |
1984年 | 87篇 |
1983年 | 69篇 |
1982年 | 58篇 |
1981年 | 50篇 |
1979年 | 68篇 |
1978年 | 49篇 |
1977年 | 52篇 |
1976年 | 50篇 |
1975年 | 51篇 |
1974年 | 63篇 |
1973年 | 59篇 |
1972年 | 49篇 |
排序方式: 共有7154条查询结果,搜索用时 46 毫秒
51.
Rosalyn A. Griffiths Dusan Hadzi-Pavlovic Lorna Channon-Little 《European eating disorders review》1994,2(4):202-220
The study reports the pre-post findings from a controlled comparative evaluation of treatments for bulimia nervosa. These pre-post results allow comparison of the hypnobehavioural and cognitive behavioural treatments with a waiting list control group and a comparison of the immediate effects of the two modalities. One hundred and thirty subjects were screened to enter the study. Seventy-eight subjects entered the investigation after being randomly allocated to either a waiting list control group, or to hypnobehavioural or cognitive behavioural groups. The treatments were delivered individually and matched in duration (8 weeks) and the number of sessions. Pre to posttreatment outcome indicated significant differences between the control group and the two treatments in reductions in bulimic behaviours and related eating pathology. The immediate effects of both treatments were equal. There were no differences at posttreatment between the treatments in abstinence from either bingeing or purging. The treatment effects were also similar to the immediate effects obtained by longer therapeutic approaches. 相似文献
52.
53.
54.
Energy expenditure and body composition in children with Crohn's
disease: effect of enteral nutrition and treatment with prednisolone 总被引:4,自引:0,他引:4
Background—Malnutrition and growth retardation arecommon complications of Crohn's disease in children. The contributionof resting energy expenditure (REE) to malnutrition is unclear.
Aims—To characterise the REE and body compositionin children with Crohn's disease and compare them with normal controlsand patients with anorexia nervosa; to compare the effects ofprednisolone and enteral nutrition on energy expenditure and body composition.
Subjects—Twenty four children with Crohn'sdisease, 19 malnourished females with anorexia nervosa, and 22 healthycontrol subjects were studied.
Methods—In children with Crohn's diseasemeasurements were done when the disease was acute and repeated at oneand three months after treatment with either prednisolone or enteralnutrition. Resting energy expenditure was measured by indirectcalorimetry and body composition by anthropometry, bioelectricalimpedance analysis, total body potassium,H218O, and bromide space studies.
Results—Body weight and ideal body weight weresignificantly lower in patients with Crohn's disease than in healthycontrols. Lean tissue was depleted and there was an increase inextracellular water. Per unit of lean body mass, there was nodifference between REE in patients with Crohn's disease and controls,whereas patients with anorexia nervosa had significantly reduced REE.With enteral nutrition all body compartments and REE increasedsignificantly (p<0.001). In a subgroup of age-matched men there was asignificant increase in height after three months of enteral nutritioncompared with prednisolone (p<0.01). Those treated with steroids didnot show a significant change in height but did show an increase in allbody compartments. However, intracellular water as well as lean bodymass accretion were significantly higher in the enteral nutrition groupthan in the prednisolone group.
Conclusions—Despite being malnourished, childrenwith Crohn's disease fail to adapt their REE per unit of lean bodymass. This might be a factor contributing to their malnutrition. Lean tissue accretion is higher in patients treated with enteral nutrition than in those treated with prednisolone.
Aims—To characterise the REE and body compositionin children with Crohn's disease and compare them with normal controlsand patients with anorexia nervosa; to compare the effects ofprednisolone and enteral nutrition on energy expenditure and body composition.
Subjects—Twenty four children with Crohn'sdisease, 19 malnourished females with anorexia nervosa, and 22 healthycontrol subjects were studied.
Methods—In children with Crohn's diseasemeasurements were done when the disease was acute and repeated at oneand three months after treatment with either prednisolone or enteralnutrition. Resting energy expenditure was measured by indirectcalorimetry and body composition by anthropometry, bioelectricalimpedance analysis, total body potassium,H218O, and bromide space studies.
Results—Body weight and ideal body weight weresignificantly lower in patients with Crohn's disease than in healthycontrols. Lean tissue was depleted and there was an increase inextracellular water. Per unit of lean body mass, there was nodifference between REE in patients with Crohn's disease and controls,whereas patients with anorexia nervosa had significantly reduced REE.With enteral nutrition all body compartments and REE increasedsignificantly (p<0.001). In a subgroup of age-matched men there was asignificant increase in height after three months of enteral nutritioncompared with prednisolone (p<0.01). Those treated with steroids didnot show a significant change in height but did show an increase in allbody compartments. However, intracellular water as well as lean bodymass accretion were significantly higher in the enteral nutrition groupthan in the prednisolone group.
Conclusions—Despite being malnourished, childrenwith Crohn's disease fail to adapt their REE per unit of lean bodymass. This might be a factor contributing to their malnutrition. Lean tissue accretion is higher in patients treated with enteral nutrition than in those treated with prednisolone.
Keywords:Crohn's disease; resting energy expenditure; bodycomposition; anorexia nervosa; prednisolone; enteral nutrition
相似文献55.
S. P. Robinson L. M. Rodrigues A. S. Ojugo P. M. McSheehy F. A. Howe J. R. Griffiths 《British journal of cancer》1997,75(7):1000-1006
Gradient-recalled echo magnetic resonance imaging (GRE MRI), which gives information on blood flow and oxygenation changes (Robinson SP, Howe FA, Griffiths JR 1995, Int J Radiat Oncol Biol Phys 33: 855), was used to observe the responses of six rodent tumour models to carbogen breathing. In one transplanted rat tumour, the Morris hepatoma 9618a, and a chemically induced rat tumour, the MNU-induced mammary adenocarcinoma, there were marked image intensity increases, similar to those previously observed in the rat GH3 prolactinoma. In contrast, the rat Walker carcinosarcoma showed no response. In two mouse tumours, the RIF-1 fibrosarcoma and the human xenograft HT29, carbogen breathing induced a transient fall in signal intensity that reversed spontaneously within a few minutes. The rat GH3 prolactinoma was xenografted into nude mice, and an increase in image intensity was found in response to carbogen, suggesting that any effects that carbogen may have had on the host were not significant determinants of the tumour response. The increases in GRE image intensity of the MNU, H9618a and GH3 tumours during carbogen breathing are consistent with increases in tumour oxygenation and blood flow, whereas the responses of the RIF-1 and HT29 tumours may be the result of a transient steal effect followed by homeostatic correction. 相似文献
56.
Peter Griffiths BA RGN & Jenifer Wilson-Barnett BA MSc PhD RGN FRCN FKCL 《Journal of advanced nursing》1998,27(6):1184-1192
A literature search was conducted to identify 'nursing led in-patient units' where the nurse is the designated leader of the clinical team. The review concentrates on studies which have attempted to measure the impact of nursing-led in-patient units and reviews both the methodology and outcomes. Three major bodies of work were identified. Lydia Hall's evaluation of the Loeb Center for Nursing and Rehabilitation (USA) is reviewed in some detail. This work was the model for 'nursing beds' at the two Oxfordshire Nursing Development Units (UK) in the 1980s. Studies evaluating these centres are reviewed and reports of similar UK units discussed. A third body of work evaluates a nurse-managed critical care environment. Common features include a case mix based on nursing need with nurses having authority to admit and discharge patients. While results are generally favourable, with improved patient independence, fewer readmissions, lower mortality and cost savings reported in some or all of the studies, all studies reviewed demonstrate the difficulties of applying an experimental model to real life clinical services. Methodological limitations render firm conclusions difficult. Techniques adopted from studies in field settings, the so-called 'quasi-experiment', are advocated as a remedy, as is further study of the process of care in investigating this model of care delivery. 相似文献
57.
58.
Immunoelectron microscopic studies reveal differences in distribution of sialo-oligosaccharide receptors for Mycoplasma pneumoniae on the epithelium of human and hamster bronchi.
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Long-chain sialo-oligosaccharides with poly-N-acetyllactosamine backbones (Ii antigen type) are major host cell receptors for the human pathogen Mycoplasma pneumoniae. Previous immunofluorescence studies of the human bronchial epithelium, using sequence-specific monoclonal antibodies to the branched I-type and linear i-type backbones, have indicated that sialylated and nonsialylated long-chain sequences of both types are richly expressed on the ciliated cells, where they are polarized at the apical aspects. These sequences are lacking in the goblet cells. In the present study, the display of these oligosaccharides has been investigated by electron microscopy (immunogold labelling) in the human bronchial epithelium and in that of the hamster, an animal model commonly used for M. pneumoniae infection. In the human bronchial epithelium, the long-chain branched sequences have been detected along the entire length of the cilia and on microvilli, whereas the linear sequences are confined to the microvilli and the basal aspects of the cilia. On the ciliated epithelial cells of the hamster, by contrast, the branched and linear sequences (sialo- and asialo-) have been detected exclusively on microvilli. A further striking difference is that in the hamster these structures are expressed in abundance on the goblet cells and in the intracellular globules. We suggest that the latter finding may partly explain the relatively large doses of M. pneumoniae required to establish experimental infection in the hamster, as the receptor-bearing secreted mucus may have a protective role in binding to the microorganisms, leading to their clearance by bronchociliary action. 相似文献
59.
New reference allelic ladders to improve allelic designation in a multiplex STR system 总被引:4,自引:0,他引:4
R. A. L. Griffiths M. D. Barber P. E. Johnson S. M. Gillbard M. D. Haywood C. D. Smith J. Arnold T. Burke A. J. Urquhart P. Gill 《International journal of legal medicine》1998,111(5):267-272
This paper reports the composition of a new reference allelic ladder mixture for use with a multiplex DNA profiling system
consisting of six short tandem repeat loci. The loci included in this mixture are HUMTH01, D21S11, D18S51, D8S1179, HUMVWAF31/A,
HUMFIBRA/FGA and an amelogenin sex test. Sequence analysis of individual ladder alleles was carried out and allelic designations
made in accordance with the recommendations of the International Society of Forensic Haemogenetics (1992; 1994). A series
of rare alleles which increase the range of alleles previously reported were identified. By including some of the rare alleles
into the ladder marker system, we have significantly improved the ability to identify new alleles in unknown samples.
Received: 12 August 1997 / Received in revised form: 7 November 1997 相似文献
60.
N. S. Doherty R. J. Griffiths J. P. Hakkinen D. N. Scampoli A. J. Milici 《Inflammation research》1995,44(4):169-177
Intraperitoneal injection of inflammatory agents in the mouse and rat causes plasma protein and leukocyte extravasation into the peritoneal cavity. Following an intraperitoneal injection of zymosan A, the milky spots of the omentum were the only abdominal sites detected where intravenously administered Monastral Blue labeled interendothelial cell gaps responsible for plasma extravasation. In addition, when colored microspheres were intraventricularly administered to quantify blood flow, the omentum was the only abdominal organ which showed an increase in blood flow during zymosan A peritonitis. A combination of light and electron microscopy, plus measurement of myeloperoxidase activity (a marker of neutrophil accumulation) demonstrated that the omental milky spots are the major route through which leukocytes migrate into the peritoneal cavity. Identical structures in the pleura likewise are the sites of protein leakage into the pleural cavity. In contrast, selective sites of protein and cellular extravasation could not be detected in the synovial lining of the inflamed knee joint. 相似文献