全文获取类型
收费全文 | 427170篇 |
免费 | 29800篇 |
国内免费 | 5739篇 |
专业分类
耳鼻咽喉 | 5988篇 |
儿科学 | 8842篇 |
妇产科学 | 10642篇 |
基础医学 | 59634篇 |
口腔科学 | 12759篇 |
临床医学 | 35958篇 |
内科学 | 86084篇 |
皮肤病学 | 9272篇 |
神经病学 | 30068篇 |
特种医学 | 16369篇 |
外国民族医学 | 103篇 |
外科学 | 65889篇 |
综合类 | 15974篇 |
现状与发展 | 14篇 |
一般理论 | 69篇 |
预防医学 | 20217篇 |
眼科学 | 10665篇 |
药学 | 36155篇 |
38篇 | |
中国医学 | 4540篇 |
肿瘤学 | 33429篇 |
出版年
2021年 | 4939篇 |
2020年 | 3780篇 |
2019年 | 4665篇 |
2018年 | 6452篇 |
2017年 | 5186篇 |
2016年 | 5261篇 |
2015年 | 6595篇 |
2014年 | 8665篇 |
2013年 | 10257篇 |
2012年 | 14152篇 |
2011年 | 14582篇 |
2010年 | 8902篇 |
2009年 | 7984篇 |
2008年 | 12271篇 |
2007年 | 13011篇 |
2006年 | 12767篇 |
2005年 | 11718篇 |
2004年 | 10553篇 |
2003年 | 10131篇 |
2002年 | 9535篇 |
2001年 | 29113篇 |
2000年 | 29620篇 |
1999年 | 24534篇 |
1998年 | 5579篇 |
1997年 | 4653篇 |
1996年 | 4125篇 |
1995年 | 3874篇 |
1994年 | 3465篇 |
1993年 | 3040篇 |
1992年 | 16339篇 |
1991年 | 15055篇 |
1990年 | 14387篇 |
1989年 | 14158篇 |
1988年 | 12759篇 |
1987年 | 12207篇 |
1986年 | 11216篇 |
1985年 | 10411篇 |
1984年 | 6975篇 |
1983年 | 5654篇 |
1982年 | 2734篇 |
1979年 | 5509篇 |
1978年 | 3362篇 |
1977年 | 2980篇 |
1975年 | 2652篇 |
1974年 | 3086篇 |
1973年 | 2880篇 |
1972年 | 2846篇 |
1971年 | 2783篇 |
1970年 | 2519篇 |
1969年 | 2554篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
目的 系统评价益气活血法联合西药治疗特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)的疗效及安全性。方法 系统检索中国知网、维普网、万方数据库、EMbase、PubMed、Cochrane Library图书馆等数据库,检索时限从数据库建库至2021年1月,纳入益气活血法联合西药治疗特发性肺纤维化的随机对照试验(randomized controlled trial,RCT),由2名研究人员独立筛选并交叉核对纳入结果,提取有效数据后,应用RevMan 5.3软件进行Meta分析。结果 纳入16项随机对照试验共计1160例IPF患者。分析结果显示益气活血法联合西药组可提高临床总有效率(OR= 3.71,95% CI [2.68,5.14],P<0.00001);改善患者肺功能:用力肺活量(MD=0.31,95% CI [0.23,0.38],P<0.00001)(MD=3.59,95% CI [1.51,5.66],P=0.0007),一氧化碳弥散量(MD=2.54,95% CI [1.83,3.25],P<0.00001);提高生活质量,降低圣乔治评分:呼吸困难(MD=-12.70,95% CI [-21.07,-4.32],P=0.003),活动能力(MD=-8.38,95% CI [-13.66,-3.10],P=0.002),疾病影响(MD=-13.87,95% CI [-22.53,-5.22],P=0.002);并可降低患者中医症状积分:喘息(MD=-0.66,95% CI [-0.84,-0.49],P<0.00001),咳嗽(MD=-0.71,95% CI [-1.04,-0.37],P<0.0001);有效提高动脉血氧分压(MD=5.92,95% CI [4.61,7.22],P<0.00001);且不增加不良事件发生率(OR=0.55,95% CI [0.27,1.14],P=0.11)。结论 益气活血法联合西药治疗IPF可提高临床治疗有效率,改善患者生活质量,且不增加临床不良事件(便秘、嗜睡、口干、恶心呕吐、皮肤瘙痒、腹泻等)发生率。但本研究纳入文献质量参差不齐,仍需更多大样本、高质量、多中心的RCT试验验证结论。 相似文献
22.
Muhammad I. Zafar Jiequn Han Xu-Hui Zhou & Heng Xiao 《Communications In Computational Physics》2022,32(2):336-363
Partial differential equations (PDEs) play a dominant role in the mathematical modeling of many complex dynamical processes. Solving these PDEs often requires
prohibitively high computational costs, especially when multiple evaluations must be
made for different parameters or conditions. After training, neural operators can provide PDEs solutions significantly faster than traditional PDE solvers. In this work,
invariance properties and computational complexity of two neural operators are examined for transport PDE of a scalar quantity. Neural operator based on graph kernel network (GKN) operates on graph-structured data to incorporate nonlocal dependencies.
Here we propose a modified formulation of GKN to achieve frame invariance. Vector
cloud neural network (VCNN) is an alternate neural operator with embedded frame
invariance which operates on point cloud data. GKN-based neural operator demonstrates slightly better predictive performance compared to VCNN. However, GKN requires an excessively high computational cost that increases quadratically with the
increasing number of discretized objects as compared to a linear increase for VCNN. 相似文献
23.
Han Louis S. Oliver Genevieve F. 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2022,260(3):1033-1034
Graefe's Archive for Clinical and Experimental Ophthalmology - 相似文献
24.
Kim Sung Jin Park Min Uk Chae Han Kyu Nam Wook Kim So Won Yu Hoon Kim Han Gwun Kang Gil Hyun Park Jong Yeon 《International journal of clinical oncology / Japan Society of Clinical Oncology》2022,27(2):403-410
International Journal of Clinical Oncology - Previous studies have shown a relationship between the occurrence and recurrence of prostate cancer; however, this relationship remains controversial.... 相似文献
25.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
26.
27.
目的:探讨姑息性胃切除联合术后化疗评分在腹膜转移的胃癌患者预后评估中的临床意义。方法:回顾性分析2010年1月至2016年12月7年间收治的287例发生腹膜转移的胃癌患者的临床病理资料。通过χ2检验分析评分与患者临床病理因素间的关系。通过Kaplan-Meier法绘制生存曲线,Log-rank检验比较患者生存率的差异;采用Cox比例风险回归模型对患者进行预后分析。结果:与评分中得分为2分和1分的患者相比,得分为0分的患者肿瘤侵润至T4b 期的患者较少[31%(18/58)比50.8%(63/124)、56.2%(59/105),P=0.039]。全组患者的中位生存时间仅为8.7月。对患者进行单因素预后分析结果显示,血清白蛋白浓度(≤40 g/L),腹水,腹膜转移范围较大,肿瘤T分期较晚,评分得分较高的患者预后较差(均P<0.05)。将上述因素纳入Cox多因素分析结果显示:评分[HR(95%CI):1.384(1.165~1.644),P=0.000],血清白蛋白浓度[HR(95%CI):0.759(0.593~0.971),P=0.028],肿瘤T分期[HR(95%CI):1.493(1.216~1.832),P=0.000]是患者预后的独立危险因素。结论:评分对于胃癌伴腹膜转移患者的预后生存评估具有重要的临床意义。 相似文献
28.
目的 探讨路径式营养管理在食管癌围术期患者中的应用效果。方法 选取2018年1月至2018年7月在四川省肿瘤医院胸外科接受食管癌根治手术治疗的患者156例,随机分为干预组(n=78)和对照组(n=78),干预组采用路径式营养管理,对照组采用常规营养管理,比较两组患者在术后7d血红蛋白、前白蛋白、体质指数(BMI)、预后营养指数(PNI)等营养指标、术后并发症发生率及术后住院时间。结果 干预组患者术后7d血红蛋白(126.09±16.69)g/L、前白蛋白(208.74±38.51)mg/L、BMI(22.28±2.05)kg/m2、PNI(46.62±4.03)优于对照组,差异有统计学意义(P<0.05);干预组患者胸腔积液发生率低于对照组,差异有统计学意义(t=4.02,P=0.04);干预组患者住院时间短于对照组,差异有统计学意义(t=6.53,P=0.03)。结论 路径式营养管理能有效改善食管癌围术期患者营养状况、降低并发症发生率、缩短术后住院时间。 相似文献
29.
Yi Su Jean W. Woo Timothy C.Y. Kwok 《Journal of the American Medical Directors Association》2019,20(1):83-89
Objectives
To examine the potential added value of a simple 5-item questionnaire for sarcopenia screening (SARC-F) to the Fracture Risk Assessment Tool (FRAX) for hip fracture risk prediction, in order to identify at-risk older adults for screening with dual-energy x-ray absorptiometry (DXA).Design
A prospective cohort study.Setting and participants
Two thousand Chinese men and 2000 Chinese women aged 65 years or older were recruited from local communities and were prospectively followed up for about 10 years.Measures
Areal bone mineral density (BMD) of hip and lumbar spine were measured by DXA at baseline. Ten-year FRAX probability of hip fracture was calculated using the baseline risk factors. Information from the baseline questionnaire was extracted to calculate a modified SARC-F score. The independent predictive values of SARC-F and FRAX questionnaire were evaluated using multivariate survival analysis. The added predictive values of SARC-F to FRAX for pre-DXA screening were examined.Results
During the follow-up, 63 (3.2%) men and 69 (3.5%) women had at least 1 incident hip fracture. SARC-F had an independent value of FRAX for hip fracture risk prediction, with an adjusted hazard ratio [95% confidence interval (CI)] of 1.24 (1.02, 1.52) and 1.15 (0.99, 1.13) in men and women, respectively. Compared with using FRAX, using SARC-F in conjunction with FRAX made the sensitivity for prediction rise from 58.7% to 76.2% in men and from 69.6% to 78.3% in women, with a nondecreased area under receiver operating characteristic curve of 0.67. Prescreening using FRAX in conjunction with SARC-F could save more than half of the DXA assessment than with no prescreening.Conclusions/Implications
SARC-F is associated with a modest increase in hip fracture risk, especially in men. Conjoint evaluation for sarcopenia in addition to FRAX screening may help identify older adults at higher risk of hip fracture for more intensive screening and/or preventive interventions. 相似文献30.