全文获取类型
收费全文 | 3087篇 |
免费 | 200篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 78篇 |
妇产科学 | 71篇 |
基础医学 | 423篇 |
口腔科学 | 34篇 |
临床医学 | 268篇 |
内科学 | 840篇 |
皮肤病学 | 35篇 |
神经病学 | 242篇 |
特种医学 | 107篇 |
外科学 | 553篇 |
综合类 | 18篇 |
预防医学 | 200篇 |
眼科学 | 48篇 |
药学 | 154篇 |
中国医学 | 6篇 |
肿瘤学 | 171篇 |
出版年
2023年 | 11篇 |
2022年 | 25篇 |
2021年 | 53篇 |
2020年 | 37篇 |
2019年 | 58篇 |
2018年 | 62篇 |
2017年 | 48篇 |
2016年 | 63篇 |
2015年 | 71篇 |
2014年 | 84篇 |
2013年 | 125篇 |
2012年 | 212篇 |
2011年 | 208篇 |
2010年 | 92篇 |
2009年 | 89篇 |
2008年 | 155篇 |
2007年 | 192篇 |
2006年 | 168篇 |
2005年 | 147篇 |
2004年 | 142篇 |
2003年 | 147篇 |
2002年 | 120篇 |
2001年 | 73篇 |
2000年 | 98篇 |
1999年 | 97篇 |
1998年 | 45篇 |
1997年 | 26篇 |
1996年 | 29篇 |
1995年 | 24篇 |
1994年 | 27篇 |
1993年 | 20篇 |
1992年 | 48篇 |
1991年 | 52篇 |
1990年 | 35篇 |
1989年 | 33篇 |
1988年 | 38篇 |
1987年 | 39篇 |
1986年 | 36篇 |
1985年 | 34篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1981年 | 11篇 |
1979年 | 23篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1975年 | 11篇 |
1971年 | 9篇 |
1969年 | 9篇 |
1933年 | 13篇 |
1932年 | 10篇 |
排序方式: 共有3294条查询结果,搜索用时 187 毫秒
71.
72.
Quality of life in chronic NSAID users: a comparison of the effect of omeprazole and misoprostol 总被引:1,自引:0,他引:1
Yeomans N Wilson I Långström G Hawkey C Naesdal J Walan A Wiklund I 《Scandinavian journal of rheumatology》2001,30(6):328-334
OBJECTIVE: To compare the impact on quality of life (QoL) of omeprazole and misoprostol during healing, and omeprazole, misoprostol, and placebo during maintenance treatment in chronic NSAID users with NSAID-associated gastroduodenal lesions. METHODS: Validated baseline and follow-up QoL questionnaires were completed by 610 patients (healing: after 4/8 weeks; maintenance: after 6 months). RESULTS: Patients with arthritis being treated with NSAIDs have a poor QoL. Rheumatoid arthritis causes more joint problems and physical mobility limitations than osteoarthritis. Chronic NSAID use causes heartburn and dyspepsia. QoL improved on both treatments (about equally on two general QOL scales), but omeprazole relieved gastrointestinal symptoms more than misoprostol, particularly reflux, abdominal pain and indigestion symptoms. During maintenance, both treatments maintained QoL, but misoprostol induced diarrhoea. CONCLUSION: QoL in arthritis patients on chronic NSAID treatment is destroyed. Omeprazole is superior to misoprostol for relief and prevention of NSAID-associated gastrointestinal symptoms allowing continued NSAID treatment without compromising the patients' QoL. 相似文献
73.
Levin M Björnheden T Evaldsson M Walenta S Wiklund O 《Arteriosclerosis, thrombosis, and vascular biology》1999,19(4):950-958
According to the anoxemia theory of atherosclerosis, an imbalance between the demand for and supply of oxygen and nutrients in the arterial wall is a key factor in atherogenesis. However, the energy metabolic state of the arterial tissue in vivo is largely unknown. We applied a bioluminescence method, metabolic imaging, to study local ATP concentrations in cryosections of normal pig and atherosclerotic and normal rabbit aorta. Some vessels were subjected to energy metabolic restrictions by incubation at different oxygen and glucose concentrations and others were rapidly frozen in liquid nitrogen to reflect the in vivo situation. Local ATP concentrations and the ATP distribution at a microscale was dependent on oxygen as well as glucose concentrations during incubation. ATP depletion was seen in the mid media of pig aorta in all incubations, but only at low oxygen concentration without glucose in the media of the thinner rabbit aorta. ATP-depleted zones were seen deep in pig media (>750 microm from the lumen) and in rabbit plaques (>300 micrometer+ from the lumen) even at high oxygen (pig 75% O2 and rabbit 21% O2) and glucose concentrations (5.6 mmol/L glucose). This observation probably illustrates an insufficient diffusion of glucose, which highlights the importance of studying the conditions for diffusion not only of oxygen but also of other metabolites in the arterial wall. In rapidly frozen vessels the medial ATP concentration was shown to be 0.6 to 0.8 micromol/g wet weight (both pig and rabbit aorta) and in pig aorta a gradient could be seen indicating higher ATP concentrations at the lumenal side. We propose that metabolic imaging, as applied to snap-frozen tissue, may be used to assess the energy metabolic situation in the arterial wall in vivo. The spatial resolution allows the detection of local variations within the arterial tree. However, steep concentration gradients (eg, near the border of the tissue) will be underestimated. The method may be extended to include determinations of glucose and lactate concentrations and will be used in parallel with an established method to assess hypoxia in the arterial wall in vivo. 相似文献
74.
Bellone S Rapa A Petri A Zavallone A Strigini L Chiorboli E Ciardi L Aguzzi A Bona G 《Journal of endocrinological investigation》2004,27(1):18-23
Leptin signals to the brain energy stores and balance while integrating neuroendocrine functions. Leptin levels in adults are higher in females than in males, while a gender-related difference in newborns is controversial. To clarify this point, in 202 healthy neonates we measured dynamic changes in leptin levels over the first month of life and looked for correlation between leptin levels and auxological and hormonal parameters. Cord leptin concentration in females was higher (p < 0.001) than in males. IGF-I, IGF-II, insulin, testosterone and 17beta-estradiol levels were similar in both sexes while insulin-like growth factor binding protein 3 (IGF-BP3) levels in females were slightly higher than in males. Leptin levels were positively associated to body weight, gestational age, IGF-BP3 levels, insulin levels and maternal body mass index (BMI) at time of delivery. In a subset of subjects (no. = 65), in comparison with cord levels, serum leptin levels were decreased on the 5th day of life (p < 0.0001) and then increased at 1 month (p < 0.0001). Positive association between leptin and weight was lost on the 5th day of life but present again at 1 month. In conclusion, our findings in a large population of neonates definitely show that leptin levels at birth are functions of gender, body weight and gestational age but not of length, cranial circumference, IGF-I and IGF-II levels. These findings, coupled with weight-independent prompt decrease after birth followed by weight-dependent increase at one month of life, suggest that leptin secretion in neonates as well as in adults mainly signals the nutritional state to the brain. 相似文献
75.
Haque R Ali IM Sack RB Farr BM Ramakrishnan G Petri WA 《The Journal of infectious diseases》2001,183(12):1787-1793
Amebiasis is the third leading parasitic cause of death worldwide, and it is not known whether immunity is acquired from a previous infection. An investigation was done to determine whether protection from intestinal infection correlated with mucosal or systemic antibody responses to the Entamoeba histolytica GalNAc adherence lectin. E. histolytica colonization was present in 0% (0/64) of children with and 13.4% (33/246) of children without stool IgA anti-GalNAc lectin antibodies (P= .001). Children with stool IgA lectin-specific antibodies at the beginning of the study had 64% fewer new E. histolytica infections by 5 months (3/42 IgA(+) vs. 47/227 IgA(-); P= .03). A stool antilectin IgA response was detected near the time of resolution of infection in 67% (12/18) of closely monitored new infections. It was concluded that a mucosal IgA antilectin antibody response is associated with immune protection against E. histolytica colonization. The demonstration of naturally acquired immunity offers hope for a vaccine to prevent amebiasis. 相似文献
76.
Quality of life in patients with endoscopy-negative heartburn: reliability and sensitivity of disease-specific instruments 总被引:22,自引:0,他引:22
Talley NJ Fullerton S Junghard O Wiklund I 《The American journal of gastroenterology》2001,96(7):1998-2004
OBJECTIVES: Endoscopy-negative gastroesophageal reflux disease (GERD) lacks objective markers of disease severity. Evaluation of therapies for GERD must therefore rely on subjective measures, including patient self-report questionnaires, to measure the clinical effectiveness of therapeutic interventions. We aimed to evaluate the previously validated Gastrointestinal Symptoms Rating Scale (GSRS) and the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaires for reliability and responsiveness to change over time. METHODS: Patients (n = 1143) with heartburn, but no esophagitis included in a randomized clinical trial assessing the effectiveness of active treatment with proton pump inhibitors over 4 wk were evaluated. RESULTS: The test-retest reliability of both questionnaires over time was good to excellent (GSRS 0.53-0.69; QOLRAD 0.65-0.76), as was the responsiveness estimated by standardized response means (GSRS reflux dimension, -1.43; QOLRAD 0.81-1.43) and effect sizes (GRSR reflux dimension, -1.74; QOLRAD 0.82-1.56). The relationship between improvement in the GSRS reflux dimension score and the amount of clinical benefit as estimated by the patients themselves (based on the Overall Treatment Evaluation) suggested a minimally clinical relevant change is 0.5 on the seven graded scales applied. The importance rating indicated that an important change in the GSRS reflux dimension and the QOLRAD dimensions is equivalent to 1.0, and a very important change to 1.5. CONCLUSIONS: The GSRS and QOLRAD are valid questionnaires that are reliable and sensitive to change. Both questionnaires should be suitable for use in clinical trials of therapeutic interventions for patients with heartburn. 相似文献
77.
We identified 35 patients who had electrodiagnostic evidence of mononeuritis multiplex and did not have diabetes or multiple nerve compressions. Their charts were reviewed to determine the etiologies of the mononeuritis multiplex and to determine how often the laboratory examination revealed a rheumatic disease in patients whose initial history and physical examination did not suggest that a rheumatic disease was present. In 11/35 (31%; CI = 17-49) a disorder capable of causing mononeuritis multiplex was diagnosed before the symptoms of mononeuritis multiplex began. Ten had a rheumatic disease; 1 had lymphoma. Nine of the other patients were suspected, on the basis of the history and physical examination, of having new onset of a rheumatic disease. Subsequent laboratory evaluation showed that 5/9 (56%; CI = 21-86) had a rheumatic disease, and 4/9 (44%; CI = 14-79) were unknowns. In 15/35 (43%; CI = 26-61) patients with mononeuritis multiplex, no rheumatic disease was suspected on the basis of the initial history and physical examination. The subsequent laboratory examination revealed an underlying rheumatic disease in 0/15 (0%; CI = 0-18). Mean clinical follow-up of 16 +/- 16 months in the patients with mononeuritis multiplex of unknown cause also failed to identify a rheumatic disease. Overall 19/35 (54%; CI = 37-71) did not have a rheumatic disease or any other known cause. Of the 14 patients with mononeuritis multiplex associated with a rheumatic disease, 5/14 (36%; CI = 13-15) had systemic lupus erythematosus; an additional patient had both lupus and the CREST syndrome.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
78.
Association of coping responses with fibromyalgia tender points in patients with systemic lupus erythematosus 总被引:1,自引:0,他引:1
OBJECTIVE: To determine the association between fibromyalgia (FM) tender points (TP) and psychological constructs in patients with systemic lupus erythematosus (SLE). METHODS: One hundred seventy-three patients with SLE were examined for FM TP, and asked to complete 2 questionnaires at the same visit, the Health-Related Hardiness Scale (HRHS), and the Mishel Uncertainty in Illness Scale (MUIS). RESULTS: The examination of FM TP showed that 38.2% had no TP, 44.5% had 1-10 TP, and 17.3% had > or = 11 TP. The mean +/- SD score of the HRHS was 155.6 +/- 19.7 (range 105.0-198.0; higher scores indicate greater hardiness), and the MUIS was 85.3 +/- 18.7 (range 41.0-132.0; higher scores indicate uncertainty). There were significant associations between FM TP and HRHS (no TP 161.2 +/- 20.2, 1-10 TP 152.5 +/- 19.7, > or = 11 TP 151.0 +/- 15.8; p = 0.0108) and between FM TP and MUIS (no TP 78.2 +/- 20.2, 1-10 TP 86.9 +/- 17.6, > or = 11 TP 95.8 +/- 14.7; p = 0.0001). CONCLUSION: This study shows a strong association between FM TP and uncertainty or lack of "hardiness." We conclude that SLE patients with FM TP are less likely to be good "copers." Prospective studies to determine if "poor coping" predicts FM in SLE are recommended. If the association between coping and FM is causal, it will justify interventions to improve coping and similar constructs, such as self-efficacy. 相似文献
79.
Reidar Winter Petri Gudmundsson Ronnie Willenheimer 《European journal of echocardiography》2005,6(1):31-40
Myocardial contrast echocardiography using power modulation real-time perfusion (RTP) is an appealing method for bedside risk stratification of patients with acute coronary syndrome. In this study, we aimed to evaluate the accuracy in predicting significant coronary stenosis of a bedside RTP adenosine stress protocol in patients with acute coronary syndrome. METHODS: Prior to coronary angiography, 36 consecutive in-patients with acute coronary syndrome underwent a bedside adenosine stress echocardiography with RTP in the coronary care unit. Visual assessment of both perfusion and wall motion was made, comparing rest and hyperaemia images. Each segment was attributed to one of the three main coronary vessel areas. RESULTS: The sensitivity of predicting significant stenosis was 87, 83 and 81% for left anterior descending, circumflex and right posterior descending areas, respectively. Specificity was 69, 67 and 60%, respectively. The positive predictive values were 83, 79 and 74%, respectively. CONCLUSIONS: RTP using adenosine is a feasible bedside tool in predicting the area of significant coronary stenosis and could be helpful as a bedside decision-making tool in the clinical setting. More studies are required to assess the clinical value of RTP adenosine stress echocardiography. 相似文献
80.
Stolen CM Yegutkin GG Kurkijärvi R Bono P Alitalo K Jalkanen S 《Circulation research》2004,95(1):50-57
Semicarbazide-sensitive amine oxidases (SSAO) are enzymes that are capable of deaminating primary amines to produce aldehyde, ammonia, and hydrogen peroxide. This activity has been associated with vascular adhesion protein-1 (VAP-1) and is found in the serum, endothelium, adipose, and smooth muscle of mammals. Circulating SSAO activity is increased in congestive heart failure, diabetes, and inflammatory liver diseases. To investigate the origin of circulating SSAO activity, two transgenic mouse models were created with full-length human VAP-1 (hVAP-1) expressed on either endothelial (mTIEhVAP-1) or adipose tissues (aP2hVAP-1), with tie-1 and adipocyte P2 promoters, respectively. Under normal conditions a circulating form of hVAP-1 was found at high levels in the serum of mice with endothelium-specific expression and at low levels in the serum of mice with adipose specific expression. The level of circulating hVAP-1 in the transgenic mice varied with gender, transgene zygosity, diabetes, and fasting. Serum SSAO activity was absent from VAP-1 knockout mice and endothelial cell-specific expression of human VAP-1 restored SSAO activity to the serum of VAP-1 knockout mice. Together, these experiments show that in the mouse VAP-1 is the only source of serum SSAO, that under physiological conditions vascular endothelial cells can be a major source of circulating VAP-1 protein and SSAO, and that serum VAP-1 can originate from both endothelial cells and adipocytes during experimental diabetes. An increased endothelial cell capacity for lymphocyte binding and altered expression of redox-sensitive proteins was also associated with the mTIEhVAP-1 transgene. 相似文献