全文获取类型
收费全文 | 12279篇 |
免费 | 988篇 |
国内免费 | 227篇 |
专业分类
耳鼻咽喉 | 164篇 |
儿科学 | 540篇 |
妇产科学 | 344篇 |
基础医学 | 1019篇 |
口腔科学 | 227篇 |
临床医学 | 1768篇 |
内科学 | 2298篇 |
皮肤病学 | 58篇 |
神经病学 | 1380篇 |
特种医学 | 282篇 |
外国民族医学 | 1篇 |
外科学 | 2017篇 |
综合类 | 717篇 |
现状与发展 | 1篇 |
预防医学 | 965篇 |
眼科学 | 94篇 |
药学 | 711篇 |
1篇 | |
中国医学 | 137篇 |
肿瘤学 | 770篇 |
出版年
2024年 | 52篇 |
2023年 | 399篇 |
2022年 | 558篇 |
2021年 | 940篇 |
2020年 | 658篇 |
2019年 | 648篇 |
2018年 | 641篇 |
2017年 | 536篇 |
2016年 | 474篇 |
2015年 | 485篇 |
2014年 | 895篇 |
2013年 | 1031篇 |
2012年 | 544篇 |
2011年 | 658篇 |
2010年 | 533篇 |
2009年 | 610篇 |
2008年 | 606篇 |
2007年 | 532篇 |
2006年 | 460篇 |
2005年 | 347篇 |
2004年 | 251篇 |
2003年 | 193篇 |
2002年 | 165篇 |
2001年 | 145篇 |
2000年 | 150篇 |
1999年 | 125篇 |
1998年 | 103篇 |
1997年 | 97篇 |
1996年 | 83篇 |
1995年 | 74篇 |
1994年 | 56篇 |
1993年 | 60篇 |
1992年 | 50篇 |
1991年 | 55篇 |
1990年 | 38篇 |
1989年 | 34篇 |
1988年 | 39篇 |
1987年 | 25篇 |
1986年 | 24篇 |
1985年 | 27篇 |
1984年 | 33篇 |
1983年 | 8篇 |
1982年 | 19篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1971年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
1.
《American journal of surgery》2023,225(1):198-205
BackgroundLiver resection is commonly performed for hepatic tumors, however preoperative risk stratification remains challenging. We evaluated the performance of contemporary prediction models for short-term mortality after liver resection in patients with and without cirrhosis.MethodsThis retrospective cohort study examined National Surgical Quality Improvement Program data. We included patients who underwent liver resections from 2014 to 2019. VOCAL-Penn, MELD, MELD-Na, ALBI, and Mayo risk scores were evaluated in terms of model discrimination and calibration for 30-day post-operative mortality.ResultsA total 15,198 patients underwent liver resection, of whom 249 (1.6%) experienced 30-day post-operative mortality. The VOCAL-Penn score had the highest discrimination (area under the ROC curve [AUC] 0.74) compared to all other models. The VOCAL-Penn score similarly outperformed other models in patients with (AUC 0.70) and without (AUC 0.74) cirrhosis.ConclusionThe VOCAL-Penn score demonstrated superior predictive performance for 30-day post-operative mortality after liver resection as compared to existing clinical standards. 相似文献
2.
3.
4.
目的 建立苏州市肺结核发病的SARIMA模型并预测发病,为苏州市肺结核防控提供参考。方法 收集结核病信息管理系统(新)中苏州市2010年1月—2018年12月肺结核月发病数,通过时间序列分析建立SARIMA模型并预测苏州市2019年肺结核的发病情况。结果 苏州市肺结核发病数具有明显的季节周期性,每年的发病最高峰为5月,发病最低谷为2月。苏州市肺结核发病数的最佳拟合模型为SARIMA (0,1,1)×(0,1,1)12,AIC=9.590,SBC=9.644,模型参数均具有统计学意义,模型残差为白噪声序列,模型的预测值与实际值平均绝对百分比误差MAPE=7.943%,模型预测精度较高。预测苏州市2019年肺结核发病数为3 467例,月发病数平均值为289例,发病水平较2018年略有下降。结论 SARIMA(0,1,1)×(0,1,1)12模型能较好拟合出苏州市肺结核发病数的时间变化趋势,可应用于苏州市肺结核月发病数的短期预测。 相似文献
5.
The Local Lymph Node Assay (LLNA) is the most common in vivo regulatory toxicology test for skin sensitisation, quantifying potency as the EC3, the concentration of chemical giving a threefold increase in thymidine uptake in the local lymph node. Existing LLNA data can, along with clinical data, provide useful comparator information on the potency of sensitisers. Understanding of the biological variability of data from LLNA studies is important for those developing non-animal based risk assessment approaches for skin allergy. Here an existing set of 94 EC3 values for 12 chemicals, all tested at least three times in the same vehicle have been analysed by calculating standard deviations (SD) for logEC3 values. The SDs range from 0.08 to 0.22. The overall SD for the 94 logEC3 values is 0.147. Thus the 95% confidence limits (2xSD) for LLNA EC3 values are within a factor of 2, comparable to those for physico-chemical measurements such as partition coefficients and solubility. The residual SDs of Quantitative Mechanistic Models (QMMs) based on physical organic chemistry parameters are similar to the overall SD of the LLNA, indicating that QMMs of this type are unlikely to be bettered for predictive accuracy. 相似文献
6.
Gynecologic Malignancy-Associated Venous Thromboembolism and Predictive Tool at Thammasat University Hospital 下载免费PDF全文
Karit JayasakoonAwassada PunyashthiraBanthisa SomboonJunya PattaraarchachaiKomsun Suwannarurk 《Asian Pacific journal of cancer prevention》2022,23(6):2113-2118
Objectives: Aims were to investigate the prevalence and risk factors of venous thromboembolism (VTE) in gynecologic malignancy cases. Value of screening tool (Caprini) for prediction of VTE was also assessed. Study design: A retrospective study of gynecologic malignancy subjects who underwent major gynecological operation via exploratory laparotomy at Thammasat University Hospital, Pathum Thani, Thailand from January 2015 to December 2020. Participants were categorized into VTE and non-VTE groups. Caprini score, associated laboratory and clinical factors of both groups were evaluated. Results: A total of 392 subjects were recruited into the study. Prevalence of VTE was 7.4 (29/392) percent. VTE was diagnosed in subjects with endometrial, ovarian and cervical cancer at percentage of 7.8 (15/192), 7.9 (11/138) and 5.7 (3/53), respectively. Demographic characters of both groups were comparable. VTE group had significant more Caprini score, platelets count and platelet lymphocyte ratio (PLR) than non-VTE group. Modified Caprini score (2 multiply Caprini score plus 1 multiply PLR) was generated for better VTE prediction. Sensitivity and specificity of Caprini (≥5.5) and modified Caprini scores (≥22.8) were 72.4 vs 39.4, and 79.3 vs 52.1 percent, respectively. Conclusion: Prevalence of VTE among gynecologic malignancy cases was 7.4 percent. The modified Caprini score was an alternative VTE predictive tool. Cut-off point of modified Caprini score at equal or more than 22.8 was proposed. 相似文献
7.
目的对比不同术式对肝内胆管结石再次手术效果,探讨肝段或肝叶切除术的优势。
方法回顾性分析2011年8月至2014年8月收治的79例肝内胆管结石再次手术患者资料,依据术式不同分为肝段(叶)切除术组(甲组,n=38)和非肝段(叶)切除术组(乙组,n=41)两组。应用SPSS 19.0软件对所有临床数据进行统计学分析,手术相关指标等以(
±s)的形式表示,组间比较采用独立t检验;术后并发症发生情况及预后情况等计数资料以例(%)的形式表示,采用χ2检验;P<0.05差异有统计学意义。
结果两组患者术中出血量、手术时间及术后住院时间相比,差异无统计学意义(P>0.05);甲组患者的术后并发症发生率5.3%(2/38)显著低于乙组22.0%(9/41)(P<0.05);甲组残留结石发生率、症状复发率2.6%(1/38)、 0(0/41)均显著低于乙组17.1%(7/41)、 12.2%(5/41)(P<0.05),差异有统计学意义(P<0.05);但两组患者的病死率2.6%(1/38)和0(0/41)相比,差异无统计学意义(P>0.05)。
结论肝段(叶)切除术能够有效改善肝内胆管结石再次手术效果,值得推广。 相似文献
8.
9.
Selcen Yuksel Selim Ayhan Vugar Nabiyev Montse Domingo-Sabat Alba Vila-Casademunt Ibrahim Obeid Francisco Sanchez Perez-Grueso Emre Acaroglu 《The spine journal》2019,19(1):71-78
BACKGROUND CONTEXT
Health-related quality of life (HRQOL) parameters have been shown to be reliable and valid in patients with adult spinal deformity (ASD). Minimum clinically important difference (MCID) has become increasingly important to clinicians in evaluating patients with a threshold of improvement that is clinically relevant.PURPOSE
To calculate MCID and minimum detectable change (MDC) values of total scores of the Core Outcome Measures Index (COMI), Oswestry Disability Index (ODI), Physical Component Summary (PCS), Mental Component Summary (MCS) of the Short Form 36 (SF-36), and Scoliosis Research Society 22R (SRS-22R) in surgically and nonsurgically treated ASD patients who have completed an anchor question at pretreatment and 1-year follow-up.STUDY DESIGN/SETTING
Prospective cohort.PATIENT SAMPLE
Surgical and nonsurgical patients from a multicenter ASD database.OUTCOME MEASURES
Self-reported HRQOL measures (COMI, ODI, SF-36, SRS-22R, and anchor question).METHODS
A total of 185 surgical and 86 nonsurgical patients from a multicenter ASD database who completed pretreatment and 1-year follow-up HRQOL scales and the anchor question at the first year follow-up were included. The anchor question was used to determine MCID for each HRQOL measure. MCIDs were calculated by an anchor-based method using latent class analysis (LCA) and MDCs by a distribution-based method.RESULTS
All differences between means of baseline and first year postoperative total score measures for all scales demonstrated statistically significant improvements in the overall population as well as the surgically treated patients but not in the nonsurgical group. The calculated MDC and MCID values of HRQOL parameters in the entire study population were 1.34 and 2.62 for COMI, 10.65 and 14.31 for ODI, 6.09 and 7.33 for SF-36 PCS, 6.14 and 4.37 for SF-36 MCS, and 0.42 and 0.71 for SRS-22R. The calculated MCID values for surgical and non-surgical treatment groups were 2.76 versus 1.20 for COMI, 14.96 versus 2.45 for ODI, 7.83 versus 2.15 for SF-36 PCS, 5.14 versus 2.03 for SF-36 MCS, and 0.94 versus 0.11 for SRS-22R; the MDC values for surgical and nonsurgical treatment groups were 1.22 versus 1.51 for COMI, 10.27 versus 9.45 for ODI, 5.16 versus 6.77 for SF-36 PCS, 6.05 versus 5.67 for SF-36 MCS, and 0.38 versus 0.43 for SRS-22R.CONCLUSIONS
This study has demonstrated that MCID calculations for the HRQOL scales in ASD using LCA yield values comparable to other studies that had used different methodologies. The most important finding was the significantly different MCIDs for COMI, ODI, SF-36 PCS and SRS-22 in the surgically and nonsurgically treated cohorts. This finding suggests that a universal MCID value, inherent to a specific HRQOL for an entire cohort of ASD may not exist. Use of different MCIDs for surgical and nonsurgical patients may be warranted. 相似文献10.