全文获取类型
收费全文 | 15848篇 |
免费 | 1073篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 168篇 |
儿科学 | 368篇 |
妇产科学 | 344篇 |
基础医学 | 2576篇 |
口腔科学 | 977篇 |
临床医学 | 1330篇 |
内科学 | 3283篇 |
皮肤病学 | 431篇 |
神经病学 | 1269篇 |
特种医学 | 406篇 |
外国民族医学 | 2篇 |
外科学 | 1681篇 |
综合类 | 93篇 |
一般理论 | 6篇 |
预防医学 | 1468篇 |
眼科学 | 403篇 |
药学 | 1167篇 |
中国医学 | 102篇 |
肿瘤学 | 896篇 |
出版年
2023年 | 123篇 |
2022年 | 264篇 |
2021年 | 454篇 |
2020年 | 321篇 |
2019年 | 394篇 |
2018年 | 505篇 |
2017年 | 330篇 |
2016年 | 415篇 |
2015年 | 462篇 |
2014年 | 627篇 |
2013年 | 729篇 |
2012年 | 1070篇 |
2011年 | 1168篇 |
2010年 | 581篇 |
2009年 | 482篇 |
2008年 | 792篇 |
2007年 | 868篇 |
2006年 | 754篇 |
2005年 | 765篇 |
2004年 | 632篇 |
2003年 | 540篇 |
2002年 | 520篇 |
2001年 | 424篇 |
2000年 | 436篇 |
1999年 | 347篇 |
1998年 | 146篇 |
1997年 | 106篇 |
1996年 | 130篇 |
1995年 | 86篇 |
1994年 | 68篇 |
1993年 | 71篇 |
1992年 | 224篇 |
1991年 | 232篇 |
1990年 | 198篇 |
1989年 | 177篇 |
1988年 | 155篇 |
1987年 | 134篇 |
1986年 | 130篇 |
1985年 | 147篇 |
1984年 | 130篇 |
1983年 | 71篇 |
1982年 | 52篇 |
1981年 | 41篇 |
1980年 | 44篇 |
1979年 | 60篇 |
1978年 | 52篇 |
1977年 | 52篇 |
1974年 | 45篇 |
1973年 | 41篇 |
1967年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
A 27-year-old man was admitted with high fever and shivers eleven days after returning from vacation in Indonesia. Physical examination, laboratory values, abdominal ultrasound, and chest x-ray were not conclusive. All blood cultures yielded growth of Salmonella enterica serovar Typhi, and typhoid fever was diagnosed. Subsequently, the patient developed septic shock and pulmonary edema.In this case report epidemiological, clinical, and therapeutic aspects of typhoid fever are discussed with special emphasis on criteria for severe typhoid fever, which is treated with additional glucocorticoids. 相似文献
2.
Philippe Nickers Luc Coppens Jean de Leval Nicolas Jansen Jean-Marie Deneufbourg 《Radiotherapy and oncology》2006,79(3):329-334
BACKGROUND AND PURPOSE: To evaluate on 201 locally advanced prostatic cancers prospectively treated in a phase II trial, the efficacy of a combination of external beam radiotherapy (39.6 Gy) and (192)Ir low dose rate brachytherapy (Bt) (40-45 Gy). PATIENTS AND METHODS: Sixty-four patients were included in the intermediate prognosis group with only one of the following adverse factors (PSA > 10 ng/ml, Gleason score > or = 7 or clinical stage > or =T2b) and 137 in the unfavourable group when at least two of these factors were present. RESULTS: The actuarial 4 years biochemical no evidence of disease is 82.8% for the entire population. It is, respectively, 97 and 76% in the intermediate and unfavourable prognosis groups (P < 0.0001). Grade > or =3 late urinary complications occurred in 13 patients (6.5%). Eight patients (4%) presented late grade 2 rectal complications but no grades 3-5 was observed. CONCLUSIONS: Even if an alpha/beta of 1.5-3 Gy theoretically favours the use of a high dose rate mode of irradiation, the early results presented here are as good as those reported for similar groups of patients with high dose rate treatments. Late toxicity is identical but our urinary toxicity is within the less favourable and rectal toxicity within the most favourable results. We can postulate that while inducing very high hyperdosage regions (V150) mainly focused on the peripheral zone, most of the Bt techniques consist of a more ablative treatment. Many of the radiobiological studies on Bt did not in fact take into account the heterogeneity of irradiation inside the CTV. This study highlights the need to explore pulsed dose rate therapies, permanent implant and new available radioisotopes such as (169)Ytterbium that will offer the safety of low and lower dose rates. The actual late toxicity of the different Bt techniques is not yet inexistent indeed. 相似文献
3.
Ayad Al Darrab Jerome Fan Christopher M B Fernandes Rosanne Zimmerman Rhonda Smith Andrew Worster Teresa Smith Kelly O'Connor 《European journal of emergency medicine》2006,13(1):32-35
STUDY OBJECTIVES: Use of fast track has been shown to improve the emergency department flow of less urgent patients. It has been speculated, however, that this could negatively affect the care of urgent patients. The objective of this study was to determine whether a dedicated fast track for less urgent patients [Canadian Triage and Acuity scale category 4/5 (CTAS 4/5)] affected (1) the time to assessment for urgent patients (CTAS 3), (2) the length of stay for less urgent patients (CTAS 4 and 5), and (3) the left-without-being-seen rate. METHODS: In June 2003, fast track was opened in our emergency department from 13:00 to 19:00 h. A before-after intervention comparison analysis was completed for 1 week in Aug 2002 and the same week in Aug 2003. Data collected included (1) time to assessment of CTAS 3 patients, (2) the length of stay for CTAS 4/5 patients, and (3) percentage of patients who left without being seen. RESULTS: A total of 368 patients were reviewed for 2002 and 380 patients were reviewed for 2003. Median time to assessment of CTAS 3 patients presenting from 13:00 to 19:00 h was reduced from 66 min (Interquartile range: 40, 94 min) in 2002 to 60 min (IQR: 38, 108 min) after fast track was open in 2003 (P = 0.95). Median length of stay of CTAS 4 and 5 patients was reduced from 170 min (IQR: 111, 256 min) to 110 min (IQR: 69, 185 min) (P < 0.001). The overall left-without-being-seen rate decreased from 5% (20/368) to 2% (9/380). CONCLUSION: A dedicated fast track for CTAS 4/5 patients can reduce the length of stay and the left-without-being-seen rate with no impact on CTAS 3 patients seen in the main emergency department. 相似文献
4.
Frank A Middleton Marco G Trauzzi Antony E Shrimpton Karen L Gentile Christopher P Morley Helena Medeiros Michele T Pato Carlos N Pato 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(1):28-32
Uniparental isodisomy (iUPD) is a rare genetic condition caused by non-disjunction during meiosis that ultimately leads to a duplication of either the maternal or paternal chromosome in the affected individual. Two types of disorders can result, those due to imprinted genes and those due to homozygosity of recessive disease-causing mutations. Here, we describe the third known case of complete chromosome 4 iUPD of maternal origin. This condition became apparent during whole genome linkage studies of psychiatric disorders in the Portuguese population. The proband is an adult female with normal fertility and no major medical complaints, but a history of major depressive disorder and multiple suicide attempts. The proband's siblings and parents had normal chromosome 4 genotypes and no history of mood disturbance. A brief review of other studies lends support for the possibility that genes on chromosome 4 might confer risk for mood disorders. We conclude that chromosome 4 maternal uniparental disomy (UPD) is a rare disorder that may present with a major depressive phenotype. The lack of a common disease phenotype between this and two other cases of chromosome 4 iUPD [Lindenbaum et al. [1991] Am J Med Genet 49(Suppl 285):1582; Spena et al. [2004] Eur J Hum Genet 12:891-898) would suggest that there is no vital maternal gene imprinting on chromosome 4. However, since there is no reported case of paternal chromosome 4 UPD, paternal gene imprinting on chromosome 4 cannot be excluded. 相似文献
5.
6.
Is colonic electrical activity a similar phenomena to small-bowel electrical activity? 总被引:4,自引:0,他引:4
Dr. José A. S. Medeiros M.D. Ph.D. Fausto A. Pontes M.D. Ph.D. Octávio A. R. O. Mesquita 《Diseases of the colon and rectum》1997,40(1):93-99
PURPOSE: This study was designed to investigate colonic spike bursts regarding 1) their migration behavior, 2) their pressure correlates, and 3) comparing colonic short spike bursts with spike bursts from migrating myoelectric complex from the small bowel. METHODS: Rectosigmoid electromyography and manometry were recorded simultaneously in seven normal volunteers and electromyography alone in five others during two hours of fasting and for two hours after one 2,100-kJ meal. One patient with an ileostomy was also studied by the same method to record the migrating myoelectric complex from the terminal ileum during fasting. RESULTS: Three kinds of spike bursts were observed in the pelvic colon: rhythmic short spike bursts, migrating long spike bursts, and nonmigrating long spike bursts. The meal significantly increased the number of migrating and nonmigrating long spike bursts (from 25 to 38.7 percent of the recording time;
P
<0.01). These bursts of potentials showed a peak 15 minutes after the meal, which may be caused by the gastrocolic reflex. Migrating long spike bursts started anywhere along the rectosigmoid and migrated from there aborad 82 percent of the time and orad or in both directions in 10 or 7 percent of the time, respectively. They originated pressure waves 99 percent of the time. Short spike bursts were more frequent before the meal (15.1 percent before and 9.6 percent after the meal), but the difference was not significant; they neither propagated nor initiated pressure waves detected by the miniballoon. CONCLUSIONS: Migrating long spike bursts were the only potentials that migrated, sometimes for short distances. Short spike bursts are a different phenomenon from the small-bowel migrating myoelectric complex because they do not migrate; they can occur during the postprandial period and never originated intraluminal pressure waves.Supported by a grant from the Instituto Nacional de Investigação Científica, Proc. DBI-22086.Presented at the meeting of the Portuguese Congress of Gastrenterology, Vila Moura, Portugal, June 2 to 5, 1993. 相似文献
7.
A study was carried out in order to document any abnormalities in the electro-encephalogram (EEG) that might appear in young adolescents who have deliberately inhaled the range of volatile substances loosely referred to as 'glue'. The EEGs of a group of 'street children' being assisted in a Johannesburg shelter were examined. The records were analysed for any clinical abnormalities and also subjected to spectral analysis in order to examine the overall characteristics of frequency, power and spatial distribution. The EEGs clearly revealed that, although at the time of the examination the subjects were ostensibly abstinent, both clinical and normative evidence of continuing brain disturbance was present. It was concluded that glue sniffing is likely to have long term electrocerebral sequelae. 相似文献
8.
L. van den Bemt M. P. de Vries L. van Knapen M. Jansen M. Goossens J. W. M. Muris C. P. van Schayck 《Clinical and experimental allergy》2006,36(2):233-237
BACKGROUND: Exposure to a high level of house dust mite allergens (HDMAs) is considered as a risk factor for HDM sensitization and development of asthma in genetically disposed people. Mattresses are one of the most important sources of HDMA in people's living environment. OBJECTIVE: The aim of this study was to evaluate the association between mattress characteristics and HDMA concentrations on mattresses. METHODS: Dust samples of mattress surfaces were taken to evaluate the level of Der p 1 allergen. All participants filled in a questionnaire about the type of mattress, the type of covering (upper layer) of the mattress, dwelling characteristics and cleaning habits. Humidity and temperature of the bedroom were measured at the time of dust sampling. RESULTS: One hundred and sixty-eight questionnaires were filled in. Synthetic upper layer of the mattress was associated with a higher level of Der p 1 compared with cotton upper layer (2.6 vs. 0.8 microg/g Der p 1). Moreover, higher relative humidity (RH) was associated with significant higher concentrations and density of Der p 1. CONCLUSIONS: Two factors were associated with lower levels of Der p 1 found on mattresses, namely: a cotton upper layer of the mattress compared with a layer of synthetic material and lower RH at the time of sampling. As far as we know, the association between type of upper layer and concentration of Der p 1 has not been described before and could lead to the formulation of practical advices in order to reduce HDMA concentrations on mattresses. 相似文献
9.
Background
Pulmonary dysfunction following cardiac surgery is believed to be caused, at least in part, by a lung vascular injury and/or atelectasis following cardiopulmonary bypass (CPB) perfusion and collapse of non-ventilated lungs. 相似文献10.
Sylvia J T Jansen Wilma Otten Anne M Stiggelbout 《Journal of clinical oncology》2004,22(15):3181-3190
PURPOSE: Many studies have determined cancer patients' preferences for adjuvant therapy, for example, by asking patients the extent of benefit they would need in order to accept the therapy. However, little is known about the determinants that influence these preferences. Our research goal was to explore which determinants underlie patients' preferences by means of a literature review. METHODS: PubMed searches were conducted to identify studies in which cancer patients' preferences for adjuvant therapy had been elicited by means of a treatment preference instrument. Twenty-three papers were evaluated with regard to reported relationships between preferences and potential determinants. A total of 40 determinants were recorded and classified into one of seven categories: (1) treatment-related determinants, (2) sociodemographic characteristics and current quality of life, (3) clinical characteristics, (4) measurement instrument-related determinants, (5) time-related determinants, (6) cognitive/affective determinants, and (7) specialist-related determinants. Results: The benefit and toxicity of treatment, experience of the treatment, and having dependents (eg, children) living at home were important determinants of patients' preferences. Furthermore, qualitative data suggested that cognitive/affective and specialist-related determinants might have a large impact on patients' treatment preferences. CONCLUSION: Our results show that patients' preferences cannot fully be explained on the basis of treatment-related determinants and patient and clinical characteristics. More research is needed in the area of cognitive/affective and specialist-related determinants because of the lack of quantitative results. Furthermore, we recommend carrying out larger studies in which the (internal) relationships between determinants and preferences are assessed in the context of a cognitive cost-benefit model. 相似文献