全文获取类型
收费全文 | 3020篇 |
免费 | 170篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 192篇 |
妇产科学 | 73篇 |
基础医学 | 415篇 |
口腔科学 | 134篇 |
临床医学 | 329篇 |
内科学 | 674篇 |
皮肤病学 | 98篇 |
神经病学 | 127篇 |
特种医学 | 444篇 |
外科学 | 195篇 |
综合类 | 47篇 |
预防医学 | 191篇 |
眼科学 | 38篇 |
药学 | 145篇 |
2篇 | |
中国医学 | 10篇 |
肿瘤学 | 137篇 |
出版年
2023年 | 13篇 |
2022年 | 46篇 |
2021年 | 54篇 |
2020年 | 52篇 |
2019年 | 60篇 |
2018年 | 78篇 |
2017年 | 56篇 |
2016年 | 55篇 |
2015年 | 80篇 |
2014年 | 98篇 |
2013年 | 110篇 |
2012年 | 135篇 |
2011年 | 143篇 |
2010年 | 141篇 |
2009年 | 121篇 |
2008年 | 111篇 |
2007年 | 141篇 |
2006年 | 98篇 |
2005年 | 91篇 |
2004年 | 47篇 |
2003年 | 40篇 |
2002年 | 60篇 |
2001年 | 55篇 |
2000年 | 40篇 |
1999年 | 41篇 |
1998年 | 129篇 |
1997年 | 163篇 |
1996年 | 133篇 |
1995年 | 111篇 |
1994年 | 116篇 |
1993年 | 98篇 |
1992年 | 34篇 |
1991年 | 37篇 |
1990年 | 38篇 |
1989年 | 54篇 |
1988年 | 47篇 |
1987年 | 42篇 |
1986年 | 53篇 |
1985年 | 46篇 |
1984年 | 27篇 |
1983年 | 15篇 |
1982年 | 25篇 |
1981年 | 29篇 |
1980年 | 25篇 |
1979年 | 4篇 |
1978年 | 10篇 |
1977年 | 18篇 |
1976年 | 25篇 |
1975年 | 14篇 |
1966年 | 3篇 |
排序方式: 共有3271条查询结果,搜索用时 15 毫秒
51.
Martins-Filho ED Câmara-Neto JB Ferraz AA Amorim M Ferraz EM 《Arquivos de gastroenterologia》2008,45(1):3-10
BACKGROUND: Obesity is one of the worlds greatest health problems. The Roux-en-Y gastric bypass is the gold standard treatment for severe obesity. Surgery in obese patients has an acceptable level of morbidity and mortality. The superobese patient, a subcategory of severe obese patients with a high surgical risk has not yet been analyzed as a group. METHODS: A retrospective and prospective cohort study was conducted enrolling 135 patients submitted to Roux-en-Y gastric bypass for treatment of severe obesity at the " Hospital das Clínicas" , Federal University of Pernambuco, Recife, PE, Brazil, between November 1997 and September 2003. The independent variables were possible risk factors of adverse outcomes: age, gender, weight, body mass index, diabetes, hypertension, hypercholesterolemia, sleep apnea, cardiopathy/coronariopathy, pneumopathy or any other co-morbidity. The dependent variables were major complications, minor complications and death. RESULTS: Diabetes (RR = 1.6 and CI = 1.02-2.40) and sleep apnea (RR = 1.8 and CI = 1.18-2.64) were associated to minor complications. Cardiopathy/coronariopathy were associated with major complications (RR = 5.42 and CI = 1.22-2.40) and death (RR = 16.25 and CI = 3.00-87.95). BMI >or=55 kg/m2 was associated with minor complications (RR = 1.58 and CI = 1.04-2.40), major complications (RR = 3.17 and CI = 1.03-9.80) and death (P = 0.007). After logistic regression, the body mass index >55 kg/m2 remained as a strong risk factor of death (OR = 3.6 and CI = 1.05-12.32). CONCLUSIONS: The body mass index >or=55 kg/m2 was the main risk factor for severe complications and death. Other risk factors affecting the outcome were diabetes, obstructive sleep apnea and cardiopathy/coronariopathy. 相似文献
52.
53.
Michael Moore Beth Stuart Samuel Coenen Chris C Butler Herman Goossens Theo JM Verheij Paul Little 《The British journal of general practice》2014,64(619):e75-e80
Background
Antibiotics are of limited overall clinical benefit for uncomplicated lower respiratory tract infection (LRTI) but there is uncertainty about their effectiveness for patients with features associated with higher levels of antibiotic prescribing.Aim
To estimate the benefits and harms of antibiotics for acute LRTI among those producing coloured sputum, smokers, those with fever or prior comorbidities, and longer duration of prior illness.Design and setting
Secondary analysis of a randomised controlled trial of antibiotic placebo for acute LRTI in primary care.Method
Two thousand and sixty-one adults with acute LRTI, where pneumonia was not suspected clinically, were given amoxicillin or matching placebo. The duration of symptoms, rated moderately bad or worse (primary outcome), symptom severity on days 2–4 (0–6 scale), and the development of new or worsening symptoms were analysed in pre-specified subgroups of interest. Evidence of differential treatment effectiveness was assessed in prespecified subgroups by interaction terms.Results
No subgroups were identified that were significantly more likely to benefit from antibiotics in terms of symptom duration or the development of new or worsening symptoms. Those with a history of significant comorbidities experienced a significantly greater reduction in symptom severity between days 2 and 4 (interaction term −0.28, P = 0.003; estimated effect of antibiotics among those with a past history −0.28 [95% confidence interval = −0.44 to −0.11], P = 0.001), equivalent to three people in 10 rating symptoms as a slight rather than a moderately bad problem. For subgroups not specified in advance antibiotics provided a modest reduction in symptom severity for non-smokers and for those with short prior illness duration (<7 days), and a modest reduction in symptom duration for those with short prior illness duration.Conclusion
There is no clear evidence of clinically meaningful benefit from antibiotics in the studied high-risk groups of patients presenting in general practice with uncomplicated LRTIs where prescribing is highest. Any possible benefit must be balanced against the side-effects and longer-term effects on antibiotic resistance. 相似文献54.
55.
56.
57.
da Silveira Fd Lopes Bde A da Fonseca CO Quirico-Santos T de Palmer Paixão IC de Amorim LM 《Journal of cancer research and clinical oncology》2012,138(8):1347-1354
Purpose
Malignant gliomas are associated with alteration in EGF/EGFR signaling. Functional EGF+61A>G polymorphism is implicated with risk, recurrence, and progression of glioma. This study aimed to establish a putative association of EGF+61A>G with risk of glioma development, production of angiogenic growth factor EGF, and the response to perillyl alcohol administered by intranasal route.Methods
The study included 83 patients with recurrent glioma enrolled in Phase I/II trial for intranasal perillyl alcohol therapy and subjects without cancer (n?=?196) as control group. DNA was extracted from blood samples, EGF genotype performed with PCR–RFLP assay, and EGF circulating levels by enzyme immunoassay. Adequate statistical tests were performed to verify associations between polymorphism and glioma risk, and genotype correlation with EGF circulating levels. The log-rank test was also used to evaluate differences on patient survival.Results
Patients with primary glioblastoma had high frequency of AA genotype (p?=?0.037) and A allele (p?=?0.037). Increased EGF circulating levels were observed in glioma patients with AA (p?=?0.042), AG (p?=?0.006), and AA?+?AG (p?=?0.008) genotypes compared with GG. Patients with GG genotype showed increased but not significant (p?>?0.05) survival rate, and EGF levels lower than 250?pg/mL was consistently (p?=?0.0374) associated with increased survival.Conclusion
Presence of EGF+61A>G polymorphism in Brazilian subjects was associated with glioma risk and increased circulating EGF levels. Better response to perillyl alcohol-based therapy was observed in a group of adult Brazilian subjects with lower EGF levels. 相似文献58.
59.
60.