全文获取类型
收费全文 | 533篇 |
免费 | 40篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 26篇 |
妇产科学 | 18篇 |
基础医学 | 94篇 |
口腔科学 | 16篇 |
临床医学 | 75篇 |
内科学 | 109篇 |
皮肤病学 | 9篇 |
神经病学 | 12篇 |
特种医学 | 53篇 |
外科学 | 92篇 |
综合类 | 23篇 |
一般理论 | 1篇 |
预防医学 | 31篇 |
眼科学 | 3篇 |
药学 | 47篇 |
中国医学 | 1篇 |
肿瘤学 | 7篇 |
出版年
2023年 | 2篇 |
2021年 | 6篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 19篇 |
2017年 | 8篇 |
2016年 | 15篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 23篇 |
2012年 | 26篇 |
2011年 | 32篇 |
2010年 | 14篇 |
2009年 | 19篇 |
2008年 | 23篇 |
2007年 | 53篇 |
2006年 | 16篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 16篇 |
2000年 | 22篇 |
1999年 | 24篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 17篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 12篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1984年 | 2篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1974年 | 5篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 5篇 |
1965年 | 1篇 |
排序方式: 共有622条查询结果,搜索用时 15 毫秒
1.
2.
Over the past decade, the unfortunate reality is that the income gap has widened between Canadian families. Educational outcomes are one of the key areas influenced by family incomes. Children from low-income families often start school already behind their peers who come from more affluent families, as shown in measures of school readiness. The incidence, depth, duration and timing of poverty all influence a child’s educational attainment, along with community characteristics and social networks. However, both Canadian and international interventions have shown that the effects of poverty can be reduced using sustainable interventions. Paediatricians and family doctors have many opportunities to influence readiness for school and educational success in primary care settings. 相似文献
3.
4.
In 1999, mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2) were first reported in patients with Rett syndrome (RTT). The MECP2 gene is located at Xq28 and consists of 4 exons. About 80-90 % of the classic RTT patients harbor mutations in the coding region of MECP2, while the molecular cause is unknown in the remaining 10-20%. Several groups have searched for large rearrangements within the MECP2 and the results indicate that a fraction of MECP2-negative RTT cases has large deletions of the MECP2. In this study we have used the Multiplex Ligation-dependent Probe Amplification (MLPA) technique to screen 45 RTT patients, who have previously been tested negative for mutations in the coding region of MECP2. The MECP2-MLPA is a semi-quantitative multiplex PCR approach. It determines the relative number of copies of each MECP2 exon. With this approach we detected seven RTT patients with genomic deletions and further characterized the deletions using real time quantitative PCR (qPCR) and long-range PCR. The seven patients were given a severity score and their X chromosome inactivation profiles were determined in order to identify a possible genotype-phenotype correlation. The results from this study indicate that large deletions in MECP2 cause classic RTT. 相似文献
5.
Contraceptive potential of a mifepristone-nomegestrol acetate sequential regimen in women 总被引:1,自引:0,他引:1
Croxatto HB; Salvatierra AM; Fuentealba B; Massai R 《Human reproduction (Oxford, England)》1998,13(12):3297-3302
The effectiveness of a sequential regimen consisting of mifepristone, 10
mg/day for 15 days, followed by nomegestrol acetate (NOMA), 5 mg/day for
the next 13 days, for inhibiting ovulation and maintaining regular bleeding
cycles was assessed in 10 surgically sterilized volunteers who were
followed for one pretreatment and three treated cycles. Hormonal
determinations in blood and urine, ovarian ultrasonography, bleeding
records in all cycles and an endometrial biopsy taken on day 22-25 of the
third treatment cycle were used to monitor the effects of treatment. During
treatment, 24 monophasic (no sustained progesterone rise above 12 nmol/l)
and six biphasic cycles were recorded. Nine follicular ruptures were
detected echographically in these 30 treated cycles, five of which occurred
in monophasic cycles. All follicular ruptures occurred on days 1-7 of NOMA
treatment. Echographic and endocrine features of ovulatory cycles were both
present in only four treated cycles (13.3%). Development of a secretory
endometrium was achieved in all cases, but it was always irregular. Regular
withdrawal bleeding occurred in all subjects and no adverse reactions were
recorded. The ovarian and endometrial effects of this regimen justify
testing its contraceptive effectiveness in phase 2 clinical trials.
相似文献
6.
7.
JE Robb LA Rymaszewski HB Bentley PT Donnan 《Surgical and radiologic anatomy : SRA》1991,13(3):181-185
Summary This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.
La valeur du sourcil cotyloidien comme repère d'analyse radiologique
Résumé Cette étude, conduite sur 7 bassins secs, apprécie l'effet de l'inclinaison du bassin sur la qualité de l'analyse radiographique de la position d'une cupule prothétique de hanche en utilisant le sourcil cotyloïdien comme repère. Une inclinaison du bassin dans les plans coronal et sagittal est aisément détectable et il n'existe pas de variation d'analyse entre les différents observateurs en dessous de 5° d'inclinaison. De plus, sur 100 radiographies antéro-postérieures de bassin choisies au hasard dans les dossiers de consultation, 90 avaient été réalisées sans incidence particulièrement adaptée et l'on pouvait repérer facilement le sourcil sur 93% d'entre elles. Les mesures faites sur des radios de routine sont donc suffisamment précises pour permettre l'évaluation de la position d'une prothèse à partir du sourcil cotyloïdien.相似文献
8.
I Ravn 《The International journal of the addictions》1987,22(9):813-823
The single-distribution theory of alcohol consumption and the derived prevention strategy, the control-of-consumption approach, are conceptualized as three probabilistic relationships between four variables, collectively called "the Ledermann string": availability, average consumption, proportion of heavy drinkers, and prevalence of damage. This conceptualization suggests four different intervention strategies, only one of which is seriously considered by advocates of the single-distribution theory: restrictions on availability. A companion article reviews the scientific literature on the relationships of the Ledermann string. 相似文献
9.
G. Erdoes A. Koster E. Ortmann M. I. Meesters D. Bolliger E. Baryshnikova B. Martinez Lopez De Arroyabe A. Ahmed M. D. Lance M. Ranucci C. von Heymann S. Agarwal H. B. Ravn 《Anaesthesia》2021,76(3):381-392
Modern four-factor prothrombin complex concentrate was designed originally for rapid targeted replacement of the coagulation factors II, VII, IX and X. Dosing strategies for the approved indication of vitamin K antagonist-related bleeding vary greatly. They include INR and bodyweight-related protocols as well as fixed dose regimens. Particularly in the massively bleeding trauma and cardiac surgery patient, four-factor prothrombin complex concentrate is used increasingly for haemostatic resuscitation. Members of the Transfusion and Haemostasis Subcommittee of the European Association of Cardiothoracic Anaesthesiology performed a systematic literature review on four-factor prothrombin complex concentrate. The available evidence has been summarised for dosing, efficacy, drug safety and monitoring strategies in different scenarios. Whereas there is evidence for the efficacy of four-factor prothrombin concentrate for a variety of bleeding scenarios, convincing safety data are clearly missing. In the massively bleeding patient with coagulopathy, our group recommends the administration of an initial bolus of 25 IU.kg-1. This applies for: the acute reversal of vitamin K antagonist therapy; haemostatic resuscitation, particularly in trauma; and the reversal of direct oral anticoagulants when no specific antidote is available. In patients with a high risk for thromboembolic complications, e.g. cardiac surgery, the administration of an initial half-dose bolus (12.5 IU.kg-1) should be considered. A second bolus may be indicated if coagulopathy and microvascular bleeding persists and other reasons for bleeding are largely ruled out. Tissue-factor-activated, factor VII-dependent and heparin insensitive point-of-care tests may be used for peri-operative monitoring and guiding of prothrombin complex concentrate therapy. 相似文献