全文获取类型
收费全文 | 589篇 |
免费 | 35篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 21篇 |
妇产科学 | 12篇 |
基础医学 | 68篇 |
口腔科学 | 8篇 |
临床医学 | 63篇 |
内科学 | 106篇 |
皮肤病学 | 9篇 |
神经病学 | 28篇 |
特种医学 | 84篇 |
外科学 | 84篇 |
综合类 | 42篇 |
预防医学 | 24篇 |
眼科学 | 6篇 |
药学 | 23篇 |
肿瘤学 | 50篇 |
出版年
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 31篇 |
2009年 | 31篇 |
2008年 | 11篇 |
2007年 | 21篇 |
2006年 | 36篇 |
2005年 | 15篇 |
2004年 | 46篇 |
2003年 | 21篇 |
2002年 | 21篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 27篇 |
1997年 | 25篇 |
1996年 | 22篇 |
1995年 | 29篇 |
1994年 | 19篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 4篇 |
1989年 | 15篇 |
1988年 | 12篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1936年 | 1篇 |
1931年 | 1篇 |
1929年 | 2篇 |
排序方式: 共有629条查询结果,搜索用时 15 毫秒
1.
2.
3.
The first 150 words of the full text of this article appear below. Key points Coronary artery disease accounts for >30% ofdeaths in Western society. The diagnosis of myocardial infarctionshould be qualified by size, causation and time from occurrence. Mortalityis reduced by immediate or primary percutaneouscoronary intervention or thrombolysis within the first 24 hof onset of ST-segment elevation myocardial infarction. Strategiesto reduce platelet activation (glycoprotein IIb/IIIa receptorantagonists, or clopidogrel) are now recommended in the treatmentof high-risk non-ST-segment myocardial infarction/unstable angina. Elevatedserum troponins may be the result of non-ischaemic myocardialdamage, especially in critical illness.
Pathophysiology
Changes in the definition of terms relating to the diagnosisof myocardial infarction (MI) have evolved by better understandingof the pathophysiology culminating in the new term of acutecoronary syndrome (ACS). Figure 1 illustrates the processesthat occur in the development of an acute coronary event. 相似文献
4.
5.
Cognitive learning during surgical residency. A model for curriculum evaluation. 总被引:1,自引:0,他引:1 下载免费PDF全文
The program summary of the American Board of Surgery In-Service Training Exam (ABSITE) can be used to quantitate cognitive learning during a surgical residency and to identify areas of curricular weakness in a residency program. Knowledge on each question is categorized as high (known) or low (unknown) depending on the percentage of residents who answered correctly. Knowledge of Level 1 (entry) residents is then compared with Level 5 (exit) residents. Each ABSITE question can thus be categorized on entry versus exit as known-known, unknown-unknown, unknown-known, and known-unknown. Only about half of unknown knowledge on entry appears to become known on exit. Very little knowledge known on entry becomes unknown on exit. Weaknesses in specific subject areas can be readily identified by ranking questions according to the number of exiting residents who answer incorrectly. Use of this technique to quantitate cognitive learning in a residency program may allow objective assessment of changes in curriculum. 相似文献
6.
Miranda Jeanne James J. Gross Jacqueline B. Persons Judy Hahn 《Cognitive therapy and research》1998,22(4):363-376
Cognitive theory holds that dysfunctionalattitudes are important risk factors for depression.Critics have questioned this view, noting that, althoughdysfunctional attitudes are elevated in depression, they are not evident in vulnerable individualswho are asymptomatic. To deal with this criticism,Miranda and Persons (1988) have advanced the mood-statedependent hypothesis, which suggests that cognitive vulnerability factors are indeed present invulnerable individuals, but remain dormant untilactivated by negative mood. To test this hypothesis, 33women with and 67 women without histories of depression reported dysfunctional attitudes before andafter a film negative mood induction. As predicted,vulnerable subjects who reported increased negative moodreported increased dysfunctional attitudes.Unexpectedly, nonvulnerable subjects who reported increasednegative mood reported decreased dysfunctionalattitudes. These findings support the mood-statedependent hypothesis, and suggest that a deficit in theability to regulate negative emotions may be animportant feature of vulnerability todepression. 相似文献
7.
8.
Berbaum KS; el-Khoury GY; Franken EA Jr; Kathol M; Montgomery WJ; Hesson W 《Radiology》1988,168(2):507-511
The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information. 相似文献
9.
I?Satish?RaoEmail author Anand?C?Loya KS?Ratnakar VR?Srinivasan 《BMC clinical pathology》2005,5(1):11
Background
Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature. 相似文献10.
Detection of reactive oxygen species (ROS) and apoptosis in human fragmented embryos 总被引:8,自引:2,他引:8
Yang HW; Hwang KJ; Kwon HC; Kim HS; Choi KW; Oh KS 《Human reproduction (Oxford, England)》1998,13(4):998-1002
In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture
environment differs from in-vivo conditions in that the oxygen
concentration is higher, and in such conditions the mouse embryos show a
higher concentration of reactive oxygen species (ROS) in simple culture
media. ROS are believed to cause damage to cell membranes and DNA
fragmentation in somatic cells. This study was conducted to ascertain the
level of H2O2 concentration within embryos and the morphological features
of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31
fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was
obtained from the IVF-embryo transfer programme. The relative intensity of
H2O2 concentrations within embryos was measured using
2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence
imaging and DNA fragmentation was observed with transmission electron
microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations
were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/-
SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and
unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed
only in fragmented embryos, and was absent in non-fragmented embryos.
Electron microscopic findings confirmed apoptotic bodies and cytoplasmic
condensation in the fragmented blastomeres. We conclude that there is a
direct relationship between increased H2O2 concentration and apoptosis, and
that further studies should be undertaken to confirm these findings.
相似文献