全文获取类型
收费全文 | 255224篇 |
免费 | 21904篇 |
国内免费 | 5945篇 |
专业分类
耳鼻咽喉 | 3630篇 |
儿科学 | 5112篇 |
妇产科学 | 5572篇 |
基础医学 | 22446篇 |
口腔科学 | 8214篇 |
临床医学 | 23101篇 |
内科学 | 24534篇 |
皮肤病学 | 3086篇 |
神经病学 | 13845篇 |
特种医学 | 7037篇 |
外国民族医学 | 18篇 |
外科学 | 23675篇 |
综合类 | 40485篇 |
现状与发展 | 12篇 |
一般理论 | 30篇 |
预防医学 | 31581篇 |
眼科学 | 3525篇 |
药学 | 26207篇 |
381篇 | |
中国医学 | 29365篇 |
肿瘤学 | 11217篇 |
出版年
2024年 | 659篇 |
2023年 | 4589篇 |
2022年 | 7281篇 |
2021年 | 11873篇 |
2020年 | 11424篇 |
2019年 | 12686篇 |
2018年 | 11421篇 |
2017年 | 10059篇 |
2016年 | 9168篇 |
2015年 | 8622篇 |
2014年 | 16813篇 |
2013年 | 17984篇 |
2012年 | 15390篇 |
2011年 | 16592篇 |
2010年 | 13338篇 |
2009年 | 11627篇 |
2008年 | 10954篇 |
2007年 | 11065篇 |
2006年 | 9523篇 |
2005年 | 8165篇 |
2004年 | 6796篇 |
2003年 | 6133篇 |
2002年 | 4776篇 |
2001年 | 4119篇 |
2000年 | 3581篇 |
1999年 | 3064篇 |
1998年 | 2515篇 |
1997年 | 2342篇 |
1996年 | 1994篇 |
1995年 | 1912篇 |
1994年 | 1680篇 |
1993年 | 1465篇 |
1992年 | 1345篇 |
1991年 | 1224篇 |
1990年 | 1129篇 |
1989年 | 1036篇 |
1988年 | 900篇 |
1987年 | 798篇 |
1986年 | 805篇 |
1985年 | 2147篇 |
1984年 | 2412篇 |
1983年 | 1503篇 |
1982年 | 1981篇 |
1981年 | 1412篇 |
1980年 | 1257篇 |
1979年 | 1079篇 |
1978年 | 887篇 |
1977年 | 692篇 |
1976年 | 811篇 |
1975年 | 568篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
71.
《Clinical neurophysiology》2020,131(4):859-865
ObjectiveWe examined selected peripheral and spinal nerves of children aged between two and seven years.MethodHigh resolution ultrasound was performed in 116 children (2–7 years of age) at 19 predefined landmarks of median, ulnar, tibial, fibular, sural and radial nerves, the vagus as well as cervical spinal nerve 5 and 6. Further, side-to-side measuring and grey-scale analysis was done at selected nerve sites.ResultsNerves of children were on average smaller than those of adults. Nerve growth correlates significantly with age in all nerves, the mean values were similar in the age of two to four years and five to seven years. Body mass index (BMI) and gender showed moderate effect at some nerve sites, however not uniformly in all. A side-to-side difference of up to 30% in median, and up to 20% in tibial nerve can occur in healthy individuals. Grey-scale analysis for echointensity has been performed in median, ulnar and tibial nerves.ConclusionNerve size increases with age, BMI and gender have moderate effect. A side-to-side-difference of up to 30% can exist.SignificanceReference values of nerve cross-sectional area, side-to-side-difference and echo intensity are necessary to detect nerve pathology in children as well as in adults. 相似文献
72.
73.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献74.
75.
《Journal of the American College of Radiology》2020,17(10):1207-1219
PurposeLobular neoplasia (LN) detected on breast core needle biopsy is frequently managed with surgical excision because of concern for undersampled malignancy. The authors performed a systematic review and meta-analysis to estimate the risk for upgrade to malignancy in the setting of imaging-concordant classic LN diagnosed on core biopsy.MethodsPubMed and Embase were searched for original articles published from 1998 to 2020 that reported rates of upgrade to malignancy for classic LN, including atypical lobular hyperplasia (ALH) and classic lobular carcinoma in situ (LCIS). Two reviewers extracted study data and assessed the following quality criteria: exclusion of variant LCIS, exclusion of imaging-discordant lesions, and outcome reporting for ≥70% of lesions. For studies meeting all criteria, pooled risks for upgrade to any malignancy (invasive carcinoma or ductal carcinoma in situ) and invasive malignancy for all LN, ALH, and LCIS were estimated using random-effects models.ResultsFor 65 full-text articles included in the review, the risk for upgrade to any malignancy ranged from 0% to 45%. Among the 16 studies that met all quality criteria for the meta-analysis, pooled risks for upgrade to any malignancy were 3.1% (95% confidence interval [CI], 1.8%-5.2%) for all LN, 2.5% (95% CI, 1.6%-3.9%) for ALH, and 5.8% (95% CI, 2.9%-11.3%) for LCIS. Risks for upgrade to invasive malignancy were 1.3% (95% CI, 0.7%-2.4%) for all LN, 0.4% (95% CI, 0.0%-4.2%) for ALH, and 3.5% (95% CI, 2.0%-5.9%) for LCIS.ConclusionsThe risk for upgrade to malignancy for LN found on breast biopsy is low. Imaging surveillance can likely be offered as an alternative to surgical management for LN, particularly for ALH. 相似文献
76.
77.
近10年来,甲状腺外科快速发展。随着甲状腺外科相关指南、专家共识的不断修订与完善,在专业团体的引导下,中国甲状腺外科在术前诊断、手术方式、治疗方法创新等方面实现了可喜发展,病人5年生存率明显提高。甲状腺疾病诊治技术快速革新、外科术式的发展与统一、多学科诊疗模式发展与应用、术后规范化管理助力疗效提高、重视特殊情况下的甲状腺癌及髓样癌诊治以及质量控制体系的建立与完善等综合发展提升了甲状腺癌诊疗的安全性、精准性,有效的改善了病人生活质量、延长生存时间,为建设健康中国贡献力量。 相似文献
78.
《Archives of Cardiovascular Diseases》2022,115(10):505-513
Central illustration: cumulative major adverse cardiac events (MACE) and bioresorbable vascular scaffold (BVS) thrombosis rates after 1, 2, 3, 4 and 5 years. 相似文献
79.
80.
Yesim Aydinok 《ISBT科学丛刊》2020,15(1):102-109
Lifetime red cell concentrate (RCC) transfusions still account for significant iron overload‐related morbidity and mortality despite chelation therapy in thalassaemia. The cumulative risk of transfusion‐transmitted infections is substantial for thalassaemia patients. Pathogen reduction technologies for RCC may imply a proactive approach against new/re‐emerging pathogens and may be an ultimate safeguard for transfusion safety in the developing countries. Red cell alloimmunization may become a significant clinical challenge in thalassaemia. The availability of high‐throughput molecular blood group antigen typing in the donors may allow perfect match transfusion, beyond ABO‐D and CEK antigen‐matched transfusions. Allogeneic stem cell transplantation (A‐SCT) is the only available curative therapy in thalassaemia, but carries a substantial risk of serious adverse events and mortality. Gene addition therapy for correction of the α‐globin chain imbalance overcomes the problems of donor availability and immunological complications of A‐SCT. Gene editing by either gene disruption or correction emerged as a potential alternative to gene addition therapy in beta‐thalassaemia. A new era of novel therapeutics targeting α/β imbalance, ineffective erythropoiesis or iron dysregulation is unfolding in thalassaemia management, and a number of those now have agents in preclinical and clinical development. Hydroxyurea (HU) may improve globin chain imbalance and be beneficial for reducing or omitting transfusion requirement. Ruxolitinib has allowed steady decrease in spleen volume that may serve for avoiding splenectomy in beta‐thalassaemia. Luspatercept may restore normal erythroid differentiation and improve anaemia. Hepcidin mimetics or TMPRSS6 inhibitors may modulate ineffective erythropoiesis by iron restriction and improve anaemia and organ iron loading. 相似文献