全文获取类型
收费全文 | 24436篇 |
免费 | 2120篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 187篇 |
儿科学 | 879篇 |
妇产科学 | 640篇 |
基础医学 | 3335篇 |
口腔科学 | 376篇 |
临床医学 | 2767篇 |
内科学 | 4402篇 |
皮肤病学 | 778篇 |
神经病学 | 2494篇 |
特种医学 | 651篇 |
外国民族医学 | 5篇 |
外科学 | 2688篇 |
综合类 | 260篇 |
一般理论 | 67篇 |
预防医学 | 3340篇 |
眼科学 | 347篇 |
药学 | 1685篇 |
1篇 | |
中国医学 | 42篇 |
肿瘤学 | 1659篇 |
出版年
2023年 | 293篇 |
2022年 | 548篇 |
2021年 | 1001篇 |
2020年 | 633篇 |
2019年 | 866篇 |
2018年 | 984篇 |
2017年 | 720篇 |
2016年 | 727篇 |
2015年 | 800篇 |
2014年 | 1043篇 |
2013年 | 1331篇 |
2012年 | 1847篇 |
2011年 | 1890篇 |
2010年 | 979篇 |
2009年 | 832篇 |
2008年 | 1394篇 |
2007年 | 1481篇 |
2006年 | 1245篇 |
2005年 | 1198篇 |
2004年 | 1063篇 |
2003年 | 974篇 |
2002年 | 764篇 |
2001年 | 294篇 |
2000年 | 287篇 |
1999年 | 260篇 |
1998年 | 221篇 |
1997年 | 168篇 |
1996年 | 116篇 |
1995年 | 134篇 |
1994年 | 96篇 |
1993年 | 95篇 |
1992年 | 181篇 |
1991年 | 163篇 |
1990年 | 152篇 |
1989年 | 157篇 |
1988年 | 125篇 |
1987年 | 134篇 |
1986年 | 114篇 |
1985年 | 120篇 |
1984年 | 102篇 |
1983年 | 74篇 |
1982年 | 68篇 |
1981年 | 62篇 |
1979年 | 71篇 |
1978年 | 53篇 |
1977年 | 61篇 |
1975年 | 58篇 |
1974年 | 71篇 |
1973年 | 61篇 |
1972年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Rachel Hillier 《British medical journal》2003,326(7397):1022
82.
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83.
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
84.
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
85.
86.
87.
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
88.
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
89.
F M MacKenzie S V Smith K E Milne K Griffiths J Legge I M Gould 《Journal of cystic fibrosis》2004,3(3):151-157
BACKGROUND: Over a 19-month pilot phase, 93 multiply resistant Gram-negative isolates from Scottish cystic fibrosis patients were sent to a referral laboratory for further investigation. METHODS: In common with the referring diagnostic laboratories, disc diffusion testing was carried out. Antibiotic susceptibility testing was also established by MIC methodology. NCCLS methods were used throughout. Twenty antibiotics were tested. RESULTS: Comparing disc diffusion results against MIC results, there were 167 (14%) major errors. By MIC, Pseudomonas aeruginosa (n = 59), Stenotrophomonas maltophilia (n = 16), Burkholderia cepacia (n = 10) and Alcaligenes xylosoxidans (n = 7) were susceptible to 18%, 11%, 4% and 35% of the antibiotics tested, respectively. Colistin and tobramycin were the most active agents against P. aeruginosa with 60% and 49%, respectively, testing susceptible. Minocycline and gentamicin were most active against S. maltophilia with 58% and 18%, respectively, testing susceptible. B. cepacia were most susceptible to co-trimoxazole (10%) and ciprofloxacin (10%). Five and six of the seven A. xylosoxidans isolates were susceptible to piperacillin and imipenem, respectively. CONCLUSIONS: Improved methods for susceptibility testing of such clinical isolates need to be employed in routine diagnostic laboratories. Levels of resistance in referred isolates were very high and similar to those described in the USA. 相似文献
90.