全文获取类型
收费全文 | 451篇 |
免费 | 19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 | 11篇 |
基础医学 | 26篇 |
口腔科学 | 6篇 |
临床医学 | 30篇 |
内科学 | 73篇 |
皮肤病学 | 8篇 |
神经病学 | 16篇 |
特种医学 | 82篇 |
外科学 | 79篇 |
综合类 | 42篇 |
预防医学 | 17篇 |
眼科学 | 6篇 |
药学 | 23篇 |
肿瘤学 | 34篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 20篇 |
2012年 | 6篇 |
2011年 | 11篇 |
2010年 | 25篇 |
2009年 | 24篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 28篇 |
2005年 | 14篇 |
2004年 | 38篇 |
2003年 | 16篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 25篇 |
1997年 | 22篇 |
1996年 | 22篇 |
1995年 | 28篇 |
1994年 | 16篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1978年 | 4篇 |
1977年 | 4篇 |
排序方式: 共有475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.
6.
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
7.
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8.
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
9.
Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented. 相似文献
10.
Pappa KA Buaron K Payne JE Sirgo MA Giefer EE 《Alimentary pharmacology & therapeutics》1999,13(4):475-481
BACKGROUND: This was a randomized, double-blind, placebo-controlled, multicentre, parallel group, dose-ranging trial of ranitidine tablets for relief of episodic heartburn. Adult out-patients who reported heartburn relieved by antacids at least seven times per week were eligible. METHODS: Patients who successfully completed a 1-week single-blind placebo run-in phase and who did not achieve adequate relief in more than 50% of heartburn episodes were randomized to a 1-week, double-blind treatment phase during which they received ranitidine doses of 25, 75 or 125 mg, or placebo. RESULTS: Of 577 patients randomized, 566 had at least one evaluable heartburn episode and were included in the intention-to-treat analysis. All three ranitidine doses were statistically significantly superior to placebo in providing overall episodic heartburn relief for the first episode (P < 0.002), last episode (P=0.004), and all episodes combined (P < 0.001). The ranitidine 75 mg and 125 mg doses provided sustained relief (relief within 60 min of dosing that lasted throughout the 4-h evaluation period) to a greater proportion of patients for each individual episode (43-56% for 75 mg and 42-57% for 125 mg) than the ranitidine 25 mg dose (35-50%) or placebo (21-29%). The incidence of adverse events was similar in all treatment groups. CONCLUSIONS: All three ranitidine doses (125, 75 and 25 mg) are safe and superior to placebo in providing adequate relief for heartburn. Ranitidine's onset of relief was progressive and clearly present by 30 min as shown by statistically significant differences for the 75 mg dose when compared to placebo. Similarly, patients treated with ranitidine 75 mg and 125 mg consumed statistically fewer rescue antacids than placebo-treated patients for the first episode. All three doses were well tolerated, with adverse event profiles similar to those of placebo. 相似文献