全文获取类型
收费全文 | 5514篇 |
免费 | 280篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 213篇 |
妇产科学 | 40篇 |
基础医学 | 377篇 |
口腔科学 | 64篇 |
临床医学 | 450篇 |
内科学 | 1039篇 |
皮肤病学 | 46篇 |
神经病学 | 250篇 |
特种医学 | 79篇 |
外国民族医学 | 1篇 |
外科学 | 1017篇 |
综合类 | 523篇 |
预防医学 | 690篇 |
眼科学 | 303篇 |
药学 | 262篇 |
1篇 | |
中国医学 | 300篇 |
肿瘤学 | 148篇 |
出版年
2024年 | 9篇 |
2023年 | 138篇 |
2022年 | 228篇 |
2021年 | 271篇 |
2020年 | 219篇 |
2019年 | 558篇 |
2018年 | 593篇 |
2017年 | 242篇 |
2016年 | 108篇 |
2015年 | 120篇 |
2014年 | 363篇 |
2013年 | 337篇 |
2012年 | 237篇 |
2011年 | 351篇 |
2010年 | 237篇 |
2009年 | 209篇 |
2008年 | 234篇 |
2007年 | 214篇 |
2006年 | 186篇 |
2005年 | 152篇 |
2004年 | 107篇 |
2003年 | 101篇 |
2002年 | 84篇 |
2001年 | 94篇 |
2000年 | 59篇 |
1999年 | 64篇 |
1998年 | 31篇 |
1997年 | 24篇 |
1996年 | 22篇 |
1995年 | 22篇 |
1994年 | 24篇 |
1993年 | 13篇 |
1992年 | 18篇 |
1991年 | 13篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 12篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 21篇 |
1984年 | 14篇 |
1983年 | 18篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1974年 | 6篇 |
排序方式: 共有5833条查询结果,搜索用时 31 毫秒
91.
《Journal of Cardiovascular Computed Tomography》2022,16(5):397-403
BackgroundPretest probability (PTP) calculators utilize epidemiological-level findings to provide patient-level risk assessment of obstructive coronary artery disease (CAD). However, their limited accuracies question whether dissimilarities in risk factors necessarily result in differences in CAD. Using patient similarity network (PSN) analyses, we wished to assess the accuracy of risk factors and imaging markers to identify ≥50% luminal narrowing on coronary CT angiography (CCTA) in stable chest-pain patients.MethodsWe created four PSNs representing: patient characteristics, risk factors, non-coronary imaging markers and calcium score. We used spectral clustering to group individuals with similar risk profiles. We compared PSNs to a contemporary PTP score incorporating calcium score and risk factors to identify ≥50% luminal narrowing on CCTA in the CT-arm of the PROMISE trial. We also conducted subanalyses in different age and sex groups.ResultsIn 3556 individuals, the calcium score PSN significantly outperformed patient characteristic, risk factor, and non-coronary imaging marker PSNs (AUC: 0.81 vs. 0.57, 0.55, 0.54; respectively, p ?< ?0.001 for all). The calcium score PSN significantly outperformed the contemporary PTP score (AUC: 0.81 vs. 0.78, p ?< ?0.001), and using 0, 1–100 and ?> ?100 cut-offs provided comparable results (AUC: 0.81 vs. 0.81, p ?= ?0.06). Similar results were found in all subanalyses.ConclusionCalcium score on its own provides better individualized obstructive CAD prediction than contemporary PTP scores incorporating calcium score and risk factors. Risk factors may not be able to improve the diagnostic accuracy of calcium score to predict ≥50% luminal narrowing on CCTA. 相似文献
92.
93.
The mesopancreas does not have well-defined boundaries but is continuous and connected through its components with the paraaortic area. The mesopancreatic resection margin has been indicated as the primary site for R1 resection after PD in pancreatic head cancer and total mesopancreas excision has been proposed to achieve adequate retropancreatic margin clearance and to minimize the likelihood of R1 resection. However, the anatomy of the mesopancreas requires extended dissection of the paraaortic area to maximize posterior clearance. The artery-first surgical approach has been developed to increase local radicality at the mesopancreatic resection margin. During PD, the artery-first approach begins with dissection of the connective tissues around the SMA. However, the concept of the mesopancreas as a boundless structure that includes circumferential tissues around the SMA, SMV, and paraaortic tissue highlights the need to shift from artery-first PD to mesopancreas-first PD to reduce the risk of R1 resection. From this perspective the “artery-first” approach, which allows for the avoidance of R2 resection risk, should be integrated into the “mesopancreas-first” approach to improve the R0 resection rate.In total mesopancreas excision and mesopancreas-first pancreaticoduodenectomies, the inclusion of the paraaortic area and circumferential area around the SMA in the resection field is necessary to control the tumour spread along the mesopancreatic resection margin rather than to control or stage the spread in the nodal basin. 相似文献
94.
95.
Alzheimer's disease (AD) represents a major health and societal issue; there is no treatment to date and the pathophysiological mechanisms underlying this disease are not well understood. Yet, there is hope that AD risk factors and thus the number of AD cases can be significantly reduced by prevention measures based on lifestyle modifications as targeted by non-pharmacological preventive interventions. So far, these interventions have rarely targeted the psycho-affective risk factors related to depression, stress, anxiety, and feeling of loneliness, which are all prevalent in ageing. This paper presents the hypothesis that the regular practice of mindfulness meditation (MM) and loving-kindness and compassion meditation (LKCM) in the ageing population constitutes a lifestyle that is protective against AD. In this model, these practices can promote cognition, mental health, and well-being by strengthening attention control, metacognitive monitoring, emotion regulation and pro-social capacities. Training these capacities could reduce the risk of AD by upregulating beneficial age-related factors such as cognitive reserve, and down-regulating detrimental age-related factors, such as stress, or depression. As an illustration, we present the Medit-Ageing study (public name Silver Santé Study), an on-going European project that assesses the impact and mechanisms of non-pharmacological interventions including meditation, in the ageing population. 相似文献
96.
Yun Chen Na Wang Xiaolian Dong Jianfu Zhu Yue Chen Qingwu Jiang Chaowei Fu 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2021,31(8):2416-2425
Background and aimsSome amino acids (AAs) may be associated with type 2 diabetes (T2DM). This study aimed to determine the associations of individual AAs with the development of T2DM in rural Chinese adults.Methods and resultsA cohort study of 1199 individuals aged 18 years or older was conducted from 2006 to 2008 in a rural community of Deqing, China, a repeated survey was done in 2015 and data linkage with the electronic health records system was performed each year for identifying new T2DM cases. A high-performance liquid chromatography approach was used to measure the baseline serum concentrations of 15 AAs. Cox proportional hazards models were used to examine the associations between AAs and the risk of incident T2DM. A total of 98 new T2DM cases were identified during the follow-up of 12 years on average. Among 15 AAs, proline was associated with an increased risk of incident T2DM after adjusted for age, sex, body mass index, fasting plasma glucose, family history of T2DM, smoking status, alcohol use, and history of hypertension, the adjusted hazard ratio for 1-standard deviation increment was 1.20 (95% confidence interval: 1.00, 1.43). The association tended to be more marked in subjects younger than 60 years and overweight/obese subjects. Among participants without hypertension, proline and phenylalanine were associated with an increased risk of incident T2DM, while aspartic acid was associated with a decreased risk.ConclusionSerum proline was associated with the risk of incident T2DM in rural Chinese adults and might be a potential predictor. 相似文献
97.
98.
99.
目的调查医科研究生对本校学习风气的评价,并具体调查了研究生对自己学习(科研)期望和态度的看法,为相关管理部门加强教育引导提供依据。方法应用自制问卷,比较某医科大学研究生总体、不同性别、不同年级、不同录取类别、不同培养层次、不同学位类型、不同专业对学风、学习期望、学习态度的看法。结果医科研究生总体对于本校学习风气的评价主要为"较好"(48.3%),其次是"一般"(25.7%)和"很好"(22.3%);不同专业、不同年级、不同录取类别(χ2=49.188,24.517,29.248;P<0.05)之间不同。研究生总体对自己学习(科研)的期望主要是优秀(43.7%)和良好(42.2%);不同年级、不同培养层次、不同录取类别之间有差异(χ2=37.788,35.836,61.120;P<0.05)。研究生总体对自己学习(科研)态度的评价主要为比较严谨(60.5%)和很严谨(19.7%);不同年级、不同培养层次、不同录取类别之间有差异(χ2=17.350,15.423,40.327;P<0.05)。结论医科研究生整体学风较好,尤其是公共卫生与预防医学专业和计划研究生;整体学习期望较高,学习态度较好。 相似文献
100.
Aleksandra Cieluch Aleksandra Uruska Marcin Nowicki Ewa Wysocka Agata Grzelka-Woźniak Justyna Flotyńska Paweł Niedźwiecki Dorota Zozulińska-Ziółkiewicz 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2021,31(4):1219-1226
Background and aimsCholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) are crucial proteins in reverse cholesterol transport. There are insufficient data on regulating these proteins by insulin therapy in type 1 diabetes mellitus (T1DM). We aimed to assess prospectively the impact of insulin therapy initiation on transfer proteins serum levels in adults with newly diagnosed T1DM.Methods and results57 adults with newly diagnosed T1DM were enrolled in the InLipoDiab1 Study. All participants were treated with subcutaneous insulin in the model of intensive insulin therapy since the diagnosis of diabetes. Serum PLTP and CETP concentrations were measured at diagnosis, after three weeks, six months, and after one year of insulin treatment, using the immunoenzymatic method ELISA.A significant decrease in PLTP and CETP concentrations were demonstrated during twelve months of insulin therapy in newly diagnosed T1DM. The dynamics of changes in the level of these proteins varied depending on the occurrence of remission after a year of the disease. In the group without remission, a significant decrease in PLTP and CETP levels appeared after six months of follow-up. The remission group was characterized by a decrease in proteins concentration only after one year of treatment. In the non-remission group, significant negative correlations were found between the daily dose of insulin and levels of PLTP and CETP.ConclusionExogenous insulin is an inhibitor of lipid transfer proteins involved in high-density lipoprotein cholesterol metabolism in the first year of treatment. 相似文献