全文获取类型
收费全文 | 135432篇 |
免费 | 14166篇 |
国内免费 | 3693篇 |
专业分类
耳鼻咽喉 | 666篇 |
儿科学 | 2335篇 |
妇产科学 | 852篇 |
基础医学 | 9702篇 |
口腔科学 | 1300篇 |
临床医学 | 21220篇 |
内科学 | 16914篇 |
皮肤病学 | 686篇 |
神经病学 | 10333篇 |
特种医学 | 25213篇 |
外国民族医学 | 118篇 |
外科学 | 10189篇 |
综合类 | 18755篇 |
现状与发展 | 11篇 |
预防医学 | 4273篇 |
眼科学 | 1364篇 |
药学 | 7704篇 |
98篇 | |
中国医学 | 3482篇 |
肿瘤学 | 18076篇 |
出版年
2024年 | 519篇 |
2023年 | 2513篇 |
2022年 | 4880篇 |
2021年 | 6501篇 |
2020年 | 5952篇 |
2019年 | 5266篇 |
2018年 | 5019篇 |
2017年 | 5759篇 |
2016年 | 6209篇 |
2015年 | 6199篇 |
2014年 | 9662篇 |
2013年 | 8848篇 |
2012年 | 8416篇 |
2011年 | 9046篇 |
2010年 | 7284篇 |
2009年 | 7169篇 |
2008年 | 7082篇 |
2007年 | 7061篇 |
2006年 | 6185篇 |
2005年 | 5403篇 |
2004年 | 4472篇 |
2003年 | 3542篇 |
2002年 | 2852篇 |
2001年 | 2663篇 |
2000年 | 2183篇 |
1999年 | 1659篇 |
1998年 | 1573篇 |
1997年 | 1559篇 |
1996年 | 1286篇 |
1995年 | 1071篇 |
1994年 | 935篇 |
1993年 | 744篇 |
1992年 | 670篇 |
1991年 | 548篇 |
1990年 | 452篇 |
1989年 | 331篇 |
1988年 | 318篇 |
1987年 | 274篇 |
1986年 | 218篇 |
1985年 | 176篇 |
1984年 | 164篇 |
1983年 | 117篇 |
1982年 | 109篇 |
1981年 | 96篇 |
1980年 | 91篇 |
1979年 | 63篇 |
1978年 | 39篇 |
1977年 | 35篇 |
1976年 | 19篇 |
1975年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
1.
2.
目的 探讨不同年龄阿尔茨海默病(AD)患者ADC值与年龄的相关性。方法 选取30例AD患者(AD组)和年龄与之相匹配的30名志愿者(对照组),按年龄段各分为6个亚组[55~59岁(n=3)、60~64岁(n=4)、65~70岁(n=9)、71~74岁(n=5)、75~80岁(n=6)、>80岁(n=3)],测量双侧海马、红核、尾状核、杏仁体、壳核ADC值,并进行配对t检验、独立样本t检验、单因素方差分析及Pearson相关分析。结果 AD组红核左、右侧ADC值有统计学差异(P=0.022)。AD组不同年龄亚组右侧海马、双侧尾状核、右侧壳核ADC值差异有统计学意义(P均<0.05);2组不同年龄亚组双侧海马、壳核、尾状核ADC值差异有统计学意义(P均<0.05)。AD组右侧海马(r=0.615,P<0.001)、右侧壳核(r=0.653,P=0.001)及双侧尾状核(左侧:r=0.397,P=0.030;右侧:r=0.429,P=0.020)ADC值与年龄呈正相关。结论 AD患者右侧海马和壳核、双侧尾状核ADC值随年龄增加而增大。ADC值可为临床预测和早期诊断AD脑内右侧海马和壳核、双侧尾状核神经退行性病变提供参考。 相似文献
3.
4.
严桂英 《中国卫生标准管理》2020,(8):95-98
目的探究益气养精法对老年肺癌患者肿瘤标志物、生存期影响。方法研究纳入60例老年肺癌患者,均由本院2016年1月-2017年1月收治,采取随机数字表法将患者分为两组,对照组患者(30例)常规化疗治疗,观察组患者(30例)在化疗基础上联合益气养精法治疗,比较两组患者治疗效果、治疗前后癌胚抗原(carcino-embryonic antigen,CEA)及血清癌抗原125(serum oncoantigen 125,CA 125)肿瘤标志物水平、不良反应情况及患者2年生存率。结果观察组患治疗有效率高于对照组,P<0.05;治疗前,两组患者CEA及CA 125水平相当,P>0.05,治疗后均改善,观察组优于对照组,P<0.05;观察组患者不良反应与对照组相当,均较低,P>0.05;观察组患者2年生存率高于对照组,P<0.05。结论益气养精法治疗老年肺癌患者效果患者,患者症状改善,不良反应少,安全可靠,且患者2年生存率较高。 相似文献
5.
6.
Hui-Ju Ch’ang 《World journal of hepatology》2015,7(16):2029-2040
The success of sorafenib in prolonging survival of patients with hepatocellular carcinoma (HCC) makes therapeutic inhibition of angiogenesis a component of treatment for HCC. To enhance therapeutic efficacy, overcome drug resistance and reduce toxicity, combination of antiangiogenic agents with chemotherapy, radiotherapy or other targeted agents were evaluated. Nevertheless, the use of antiangiogenic therapy remains suboptimal regarding dosage, schedule and duration of therapy. The issue is further complicated by combination antiangiogenesis to other cytotoxic or biologic agents. There is no way to determine which patients are most likely respond to a given form of antiangiogenic therapy. Activation of alternative pathways associated with disease progression in patients undergoing antiangiogenic therapy has also been recognized. There is increasing importance in identifying, validating and standardizing potential response biomarkers for antiangiogenesis therapy for HCC patients. In this review, biomarkers for antiangiogenesis therapy including systemic, circulating, tissue and imaging ones are summarized. The strength and deficit of circulating and imaging biomarkers were further demonstrated by a series of studies in HCC patients receiving radiotherapy with or without thalidomide. 相似文献
7.
This retrospective study aimed to evaluate radiation-induced pneumonitis (RIP) and a related condition that we define in this report—prolonged minimal RIP (pmRIP)—after stereotactic body radiotherapy (SBRT) for Stage I primary lung cancer in patients with chronic obstructive pulmonary disease (COPD). We assessed 136 Stage I lung cancer patients with COPD who underwent SBRT. Airflow limitation on spirometry was classified into four Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, with minor modifications: GOLD 1 (mild), GOLD 2 (moderate), GOLD 3 (severe) and GOLD 4 (very severe). On this basis, we defined two subgroups: COPD-free (COPD −) and COPD-positive (COPD +). There was no significant difference in overall survival or cause-specific–survival between these groups. Of the 136 patients, 44 (32%) had pmRIP. Multivariate analysis showed that COPD and the Brinkman index were statistically significant risk factors for the development of pmRIP. COPD and the Brinkman index were predictive factors for pmRIP, although our findings also indicate that SBRT can be tolerated in early lung cancer patients with COPD. 相似文献
8.
《Diagnostic and interventional imaging》2020,101(9):555-564
PurposeThe purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC).Materials and MethodsEighty-nine patients with AIP (65 men, 24 women; mean age, 59.7 ± 13.9 [SD] years; range: 21–83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1 ± 12.3 [SD] years; range: 36–86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5 mm thickness/increment) were compared with thick-slices images (3 or 5 mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing.ResultsThe pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8–100%), 83.9% (52:67; 95% CI: 74.7–93.0%) and 77.4% (48/62; 95% CI: 67.0–87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6–100%) and 100% specificity (33/33; 95% CI: 93–100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8–100%) and area under the curve of 0.975 (95% CI: 0.936–1.0).ConclusionsRadiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%. 相似文献
9.
10.