全文获取类型
收费全文 | 11561篇 |
免费 | 1388篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 133篇 |
儿科学 | 437篇 |
妇产科学 | 377篇 |
基础医学 | 1743篇 |
口腔科学 | 164篇 |
临床医学 | 1586篇 |
内科学 | 2129篇 |
皮肤病学 | 200篇 |
神经病学 | 1379篇 |
特种医学 | 257篇 |
外科学 | 1359篇 |
综合类 | 257篇 |
一般理论 | 10篇 |
预防医学 | 1196篇 |
眼科学 | 283篇 |
药学 | 874篇 |
中国医学 | 8篇 |
肿瘤学 | 559篇 |
出版年
2021年 | 166篇 |
2020年 | 134篇 |
2019年 | 213篇 |
2018年 | 233篇 |
2017年 | 194篇 |
2016年 | 160篇 |
2015年 | 192篇 |
2014年 | 300篇 |
2013年 | 399篇 |
2012年 | 566篇 |
2011年 | 604篇 |
2010年 | 345篇 |
2009年 | 284篇 |
2008年 | 499篇 |
2007年 | 572篇 |
2006年 | 563篇 |
2005年 | 560篇 |
2004年 | 506篇 |
2003年 | 488篇 |
2002年 | 450篇 |
2001年 | 371篇 |
2000年 | 374篇 |
1999年 | 306篇 |
1998年 | 135篇 |
1997年 | 130篇 |
1996年 | 97篇 |
1995年 | 111篇 |
1994年 | 85篇 |
1993年 | 82篇 |
1992年 | 211篇 |
1991年 | 211篇 |
1990年 | 215篇 |
1989年 | 209篇 |
1988年 | 224篇 |
1987年 | 200篇 |
1986年 | 202篇 |
1985年 | 165篇 |
1984年 | 125篇 |
1983年 | 133篇 |
1982年 | 102篇 |
1981年 | 87篇 |
1980年 | 86篇 |
1979年 | 141篇 |
1978年 | 121篇 |
1977年 | 84篇 |
1976年 | 95篇 |
1975年 | 96篇 |
1974年 | 118篇 |
1973年 | 101篇 |
1971年 | 100篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Harinakshi Sanikini David C. Muller Marisa Sophiea Sabina Rinaldi Antonio Agudo Eric J. Duell Elisabete Weiderpass Kim Overvad Anne Tjønneland Jytte Halkjær Marie-Christine Boutron-Ruault Franck Carbonnel Iris Cervenka Heiner Boeing Rudolf Kaaks Tilman Kühn Antonia Trichopoulou Georgia Martimianaki Anna Karakatsani Valeria Pala Domenico Palli Amalia Mattiello Rosario Tumino Carlotta Sacerdote Guri Skeie Charlotta Rylander María-Dolores Chirlaque López Maria-Jose Sánchez Eva Ardanaz Sara Regnér Tanja Stocks Bas Bueno-de-Mesquita Roel C.H. Vermeulen Dagfinn Aune Tammy Y.N. Tong Nathalie Kliemann Neil Murphy Marc Chadeau-Hyam Marc J. Gunter Amanda J. Cross 《International journal of cancer. Journal international du cancer》2020,146(4):929-942
Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5–25 kg/m2: HR = 1.94, 95% CI: 1.25–3.03) and women (HR = 2.66, 95% CI: 1.15–6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99–6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52–4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35–14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76–18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14–0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32–0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04–3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers. 相似文献
3.
Recognizing and managing a deteriorating patient: a randomized controlled trial investigating the effectiveness of clinical simulation in improving clinical performance in undergraduate nursing students
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
4.
5.
6.
Three cases of enteritis necroticans seen at Port Moresby General Hospital are described. All three cases proved diagnostic problems and in all three the diagnosis was made only at laparotomy. While the condition is uncommon in Port Moresby, these cases indicate that it must now be considered earlier rather than later. 相似文献
7.
8.
Cough and paradoxical vocal fold motion 总被引:8,自引:0,他引:8
Kenneth W. Altman MD PhD C. Blake Simpson MD Milan R. Amin MD Mona Abaza MD Ron Balkissoon MD Roy R. Casiano MD 《Otolaryngology--head and neck surgery》2002,127(6):501-511
OBJECTIVES: The differential diagnosis and treatment of patients with chronic cough, paradoxical vocal fold motion, and disordered breathing can be a challenge to most practicing otolaryngologists. Tracheobronchial (ie, asthma, bronchitis, and tracheal stenosis), laryngeal (ie, vocal fold paralysis and neoplasms), and rhinologic (ie, allergies and rhinosinusitis) etiologies are commonly diagnosed and treated effectively. However, occasionally one is faced with patients who are refractory to medical treatment and have no obvious rhinologic, laryngeal or pulmonary cause. STUDY DESIGN AND SETTING: We conducted a review of the literature. METHODS: We present a thorough review of the current medical literature exploring the complex neurologic mechanisms involved in the production of cough and the relationship between gastroesophageal reflux disease, vagal neurapathy, and paradoxical vocal fold motion. RESULTS: The diagnosis and successful treatment of chronic cough can be complex. It requires a thorough understanding of the neurologic mechanisms behind cough excitation and suppression. Successful treatment strategies include aggressive management of the patient's reactive airway disease, gastroesophageal reflux disease, and, in select cases, paradoxical vocal fold motion. This may involve a well-coordinated effort among pulmonologists, otolaryngologists, gastroenterologists, and speech pathologists. CONCLUSION: Gastroesophageal reflux disease, vagal neuropathy, and paradoxical vocal fold motion are additional causes of chronic cough and disordered breathing that need to be considered, in the absence of obvious laryngotracheal and/or rhinologic pathology. A high index of suspicion is essential in making the diagnosis and formulating an effective multidisciplinary treatment plan for these patients. 相似文献
9.
Many important pharmaceutical agents, including vancomycin, bleomycin, cyclosporin, and several antibiotics, are produced by non‐ribosomal peptide synthetase (NRPS) enzymes in microorganisms. The NRPS pathway produces an extensive library of products using multienzyme complexes acting in an assembly‐line fashion. Engineering an NRPS system to produce an even greater variety of products, some of which may also have beneficial therapeutic value, would be an enormous advantage. Several approaches have been successful in generating novel NRPS products: mutational biosynthesis during which nonnatural substrates are fed to an organism; domain and module swapping between different species to generate hybrid enzymes; and rational site‐directed mutagenesis, based either on phylogeny or computational prediction, intended to switch substrate specificity and produce altered products. This review will highlight the progress in these areas and describe research in the future that will extend the capacity for re‐engineering NRPS systems. Drug Dev. Res. 66:9–18, 2006. © 2006 Wiley‐Liss, Inc. 相似文献
10.