全文获取类型
收费全文 | 1355050篇 |
免费 | 116066篇 |
国内免费 | 6415篇 |
专业分类
耳鼻咽喉 | 17041篇 |
儿科学 | 43653篇 |
妇产科学 | 36851篇 |
基础医学 | 185497篇 |
口腔科学 | 36723篇 |
临床医学 | 122454篇 |
内科学 | 282462篇 |
皮肤病学 | 32331篇 |
神经病学 | 111516篇 |
特种医学 | 56357篇 |
外国民族医学 | 275篇 |
外科学 | 213926篇 |
综合类 | 31799篇 |
现状与发展 | 2篇 |
一般理论 | 428篇 |
预防医学 | 107570篇 |
眼科学 | 28777篇 |
药学 | 95383篇 |
5篇 | |
中国医学 | 2261篇 |
肿瘤学 | 72220篇 |
出版年
2018年 | 14159篇 |
2017年 | 11125篇 |
2016年 | 13306篇 |
2015年 | 14857篇 |
2014年 | 20769篇 |
2013年 | 30713篇 |
2012年 | 37664篇 |
2011年 | 40316篇 |
2010年 | 25089篇 |
2009年 | 24573篇 |
2008年 | 37381篇 |
2007年 | 39770篇 |
2006年 | 40812篇 |
2005年 | 39270篇 |
2004年 | 37423篇 |
2003年 | 36403篇 |
2002年 | 34359篇 |
2001年 | 66441篇 |
2000年 | 68263篇 |
1999年 | 56909篇 |
1998年 | 16840篇 |
1997年 | 15120篇 |
1996年 | 16110篇 |
1995年 | 16339篇 |
1994年 | 15182篇 |
1993年 | 14222篇 |
1992年 | 47290篇 |
1991年 | 45949篇 |
1990年 | 44136篇 |
1989年 | 41967篇 |
1988年 | 38905篇 |
1987年 | 38242篇 |
1986年 | 36000篇 |
1985年 | 34752篇 |
1984年 | 26436篇 |
1983年 | 22200篇 |
1982年 | 13917篇 |
1981年 | 12498篇 |
1980年 | 11761篇 |
1979年 | 23630篇 |
1978年 | 17121篇 |
1977年 | 14436篇 |
1976年 | 13210篇 |
1975年 | 13771篇 |
1974年 | 16139篇 |
1973年 | 15451篇 |
1972年 | 14211篇 |
1971年 | 13073篇 |
1970年 | 11919篇 |
1969年 | 11127篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Usha Patel Manish Pandey Sadhana Kannan Tanuja A. Samant Poonam Gera Neha Mittal Swapnil Rane Asawari Patil Vanita Noronha Amit Joshi Vijay M. Patil Kumar Prabhash Manoj B. Mahimkar 《British journal of cancer》2020,123(12):1757
Background Anti-EGFR-based therapies have limited success in HNSCC patients. Predictive biomarkers are greatly needed to identify the patients likely to be benefited from these targeted therapies. Here, we present the prognostic and predictive association of biomarkers in HPV-negative locally advanced (LA) HNSCC patients.Methods Treatment-naive tumour tissue samples of 404 patients, a subset of randomised Phase 3 trial comparing cisplatin radiation (CRT) versus nimotuzumab plus cisplatin radiation (NCRT) were analysed to evaluate the expression of HIF1α, EGFR and pEGFR by immunohistochemistry and EGFR gene copy change by FISH. Progression-free survival (PFS), locoregional control (LRC) and overall survival (OS) were estimated by Kaplan–Meier method. Hazard ratios were estimated by Cox proportional hazard models.Results Baseline characteristics of the patients were balanced between two treatment groups (CRT vs NCRT) and were representative of the trial cohort. The median follow-up was of 39.13 months. Low HIF1α was associated with better PFS [HR (95% CI) = 0.62 (0.42–0.93)], LRC [HR (95% CI) = 0.56 (0.37–0.86)] and OS [HR (95% CI) = 0.63 (0.43–0.93)] in the CRT group. Multivariable analysis revealed HIF1α as an independent negative prognostic biomarker. For patients with high HIF1α, NCRT significantly improved the outcomes [PFS:HR (95% CI) = 0.55 (0.37–0.82), LRC:HR (95% CI) = 0.55 (0.36–0.85) and OS:HR (95% CI) = 0.54 (0.36–0.81)] compared to CRT. While in patients with low HIF1α, no difference in the clinical outcomes was observed between treatments. Interaction test suggested a predictive value of HIF1α for OS (P = 0.008).Conclusions High HIF1α expression is a predictor of poor clinical response to CRT in HPV-negative LA-HNSCC patients. These patients with high HIF1α significantly benefited with the addition of nimotuzumab to CRT.Clinical trial registration Registered with the Clinical Trial Registry of India (Trial registration identifier—CTRI/2014/09/004980).Subject terms: Tumour biomarkers, Head and neck cancer, Tumour biomarkers, Head and neck cancer, Predictive markers 相似文献
52.
Recurrent Oral and Genital Ulcers in an Infant: Neonatal Presentation of Pediatric Behçet Disease 下载免费PDF全文
Emma F. Johnson M.D. Danielle M. Hawkins M.D. Laura K. Gifford M.D. Aimee C. Smidt M.D. 《Pediatric dermatology》2015,32(5):714-717
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children. 相似文献
53.
54.
55.
56.
57.
B.B. Damian T.C.S. Bonetti D.D.G. Horovitz 《Brazilian journal of medical and biological research》2015,48(1):25-33
Preimplantation genetic diagnosis (PGD) was originally developed to diagnose
embryo-related genetic abnormalities for couples who present a high risk of a
specific inherited disorder. Because this technology involves embryo selection, the
medical, bioethical, and legal implications of the technique have been debated,
particularly when it is used to select features that are not related to serious
diseases. Although several initiatives have attempted to achieve regulatory
harmonization, the diversity of healthcare services available and the presence of
cultural differences have hampered attempts to achieve this goal. Thus, in different
countries, the provision of PGD and regulatory frameworks reflect the perceptions of
scientific groups, legislators, and society regarding this technology. In Brazil,
several texts have been analyzed by the National Congress to regulate the use of
assisted reproduction technologies. Legislative debates, however, are not conclusive,
and limited information has been published on how PGD is specifically regulated. The
country requires the development of new regulatory standards to ensure adequate
access to this technology and to guarantee its safe practice. This study examined
official documents published on PGD regulation in Brazil and demonstrated how little
direct oversight of PGD currently exists. It provides relevant information to
encourage reflection on a particular regulation model in a Brazilian context, and
should serve as part of the basis to enable further reform of the clinical practice
of PGD in the country. 相似文献
58.
Discordant Electrocardiogram Left Ventricular Wall Thickness and Strain Findings in Influenza Myocarditis 下载免费PDF全文
Nael Hawwa M.D. Zoran B. Popovic M.D. Ph.D. Hussain A. Isma'eel M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(12):1880-1884
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain. 相似文献
59.
BACKGROUND Metabolic disturbances including changes in serum calcium,magnesium or phosphate(P) influence the prevalence of type 2 diabetes mellitus(DM).We assessed the importance of serum P in elderly patients with type 2 DM vs nondiabetes mellitus(non-DM) in relation to renal function.AIM To determine the association between serum P and serum glucose or insulin resistance in diabetic and non-diabetic patients.METHODS One hundred-ten subjects with a mean age of 69.02±14.3 years were enrolled.Twenty-nine of the participants had type 2 DM(26.4%).The incidence of hypertension,smoking and receiving vitamin D(vitD) derivates were recorded.The participants were classified by both estimated glomerular filtration rate(eGFR) and albuminuria categories according to the Kidney Disease Improving Global Outcomes 2012 criteria.RESULTS We divided the patients in two groups according to the P cut-off point related to DM value.A comparison between high and low P showed that body mass index30.2±6.3 vs 28.1±4.6(P=0.04),mean glucose 63.6 vs 50.2(P=0.03),uric acid 6.7±1.6 vs 6.09±1.7(P=0.05),mean intact-parathyroid hormone 68.06 vs 47.4(P=0.001),systolic blood pressure 147.4±16.7 vs 140..2±16.1(P=0.02),mean albuminuria 63.2 vs 50.6(P=0.04) and eGFR 45.6±22.1 vs 55.4±21.5(P=0.02)were significantly different.χ~2 tests showed a significant association between high P and DM,hypertension,receiving vitD,smoking and eGFR stage(χ~2=6.3,P=0.01,χ~2=3.9,P=0.03,χ~2=6.9,P=0.009,χ~2=7.04,P=0.01 and χ~2=7.36,P=0.04,respectively).The adjusted model showed that older age,female gender and increased body mass index were significant predictors of type 2 DM when entering the covariates.CONCLUSION High serum P contributes to vascular and metabolic disturbances in elderly patients with type 2 DM and renal impairment. 相似文献
60.