全文获取类型
收费全文 | 659415篇 |
免费 | 46203篇 |
国内免费 | 18797篇 |
专业分类
耳鼻咽喉 | 9011篇 |
儿科学 | 13346篇 |
妇产科学 | 11810篇 |
基础医学 | 53220篇 |
口腔科学 | 14505篇 |
临床医学 | 72164篇 |
内科学 | 89627篇 |
皮肤病学 | 7187篇 |
神经病学 | 27870篇 |
特种医学 | 35972篇 |
外国民族医学 | 208篇 |
外科学 | 80697篇 |
综合类 | 103979篇 |
现状与发展 | 44篇 |
一般理论 | 29篇 |
预防医学 | 46793篇 |
眼科学 | 10185篇 |
药学 | 47956篇 |
483篇 | |
中国医学 | 35223篇 |
肿瘤学 | 64106篇 |
出版年
2023年 | 9305篇 |
2022年 | 18278篇 |
2021年 | 24733篇 |
2020年 | 22314篇 |
2019年 | 26658篇 |
2018年 | 24335篇 |
2017年 | 22056篇 |
2016年 | 20858篇 |
2015年 | 20879篇 |
2014年 | 40574篇 |
2013年 | 39980篇 |
2012年 | 37554篇 |
2011年 | 40832篇 |
2010年 | 33168篇 |
2009年 | 31816篇 |
2008年 | 31483篇 |
2007年 | 32833篇 |
2006年 | 29594篇 |
2005年 | 26043篇 |
2004年 | 21047篇 |
2003年 | 18292篇 |
2002年 | 14896篇 |
2001年 | 13835篇 |
2000年 | 11501篇 |
1999年 | 9676篇 |
1998年 | 8285篇 |
1997年 | 7732篇 |
1996年 | 6268篇 |
1995年 | 5952篇 |
1994年 | 5430篇 |
1993年 | 4198篇 |
1992年 | 3988篇 |
1991年 | 3372篇 |
1990年 | 3020篇 |
1989年 | 2654篇 |
1988年 | 2568篇 |
1987年 | 2218篇 |
1986年 | 1938篇 |
1985年 | 4804篇 |
1984年 | 5671篇 |
1983年 | 3860篇 |
1982年 | 4520篇 |
1981年 | 4111篇 |
1980年 | 3672篇 |
1979年 | 3318篇 |
1978年 | 2847篇 |
1977年 | 2178篇 |
1976年 | 2364篇 |
1975年 | 1741篇 |
1974年 | 1509篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
目的 建立蒙药绿松石的质量标准。方法 收集不同产地绿松石,共10批。观察绿松石样品和粉末的性状并进行理化鉴别;按2020年版《中国药典》(四部)通则方法测定绿松石样品中水分、浸出物含量;采用原子吸收光谱法测定绿松石样品铜元素含量。结果 绿松石为不规则、周围带有黑石的块状物,表面蓝绿色,体重,质硬脆,难砸碎,断面呈贝壳状,蜡样光泽,粉末呈灰绿色,无臭,味淡;理化鉴别结果显示,呈铜盐反应;10批次样品中水分含量为0.41%-3.94%(SD=1.37%),浸出物含量为0.21%-0.81%(SD=0.21%),铜元素含量为3.03%-4.63%(SD=0.63%)。结论 初步拟定绿松石中水分含量不得超多5.0%、浸出物含量不得低于0.10%,铜元素含量应为2.60%-4.84%,制定的标准可用于蒙药材绿松石的质量控制。 相似文献
2.
3.
BackgroundTo investigate perioperative complication rates at radical nephrectomy (RN) according to inferior vena cava thrombectomy (IVC-T) status and stage (metastatic vs non-metastatic) within kidney cancer patients.Materials and methodsWe ascertained perioperative complication rates within the National Inpatient Sample database (2016–2019). First, log-link linear Generalized Estimating Equation function (GEE) regression models (adjusted for hospital clustering and weighted for discharge disposition) tested complication rates in IVC-T patients, according to metastatic stage. Subsequently, a subgroup analysis relied on RN patients with or without IVC-T. Here, multivariable logistic regression models tested complication rates in RN patients according to IVC-T status, after propensity score matching including metastatic stage.ResultsOf 26,299 RN patients, 461 (2%) patients underwent IVC-T. Of those, 252 (55%) were non-metastatic vs 209 (45%) were metastatic. Rates of acute kidney injury (AKI), transfusion, cardiac, thromboembolic and other medical complications in non-metastatic vs metastatic patients were 40 vs 40%, 25 vs 22%, 21 vs 23%, 19 vs 14% and 38 vs 40%, respectively (all p ≥ 0.2). Metastatic stage in IVC-T patients did not predict differences in complications in log-link linear GEE regression models (all p > 0.1). However, in logistic regression models with propensity score matching, relying on the overall cohort of RN patients, IVC-T status was associated with higher complication rates (all p < 0.001): AKI (Odds ratio [OR]:2.60; 95%-CI [95%-Confidence interval: 1.97–3.44), transfusions (OR:2.40; 95%-CI: 1.72–3.36), cardiac (OR:2.27; 95%-CI: 1.49–3.47), thromboembolic (OR:9.07; 95%-CI: 5.21–16.58) and other medical complications (OR:2.01; 95%-CI: 1.52–2.66).ConclusionsThe current analyses indicate that presence of concomitant IVC-T is associated with higher complication rate at RN. Conversely, metastatic stage has no effect on recorded complication rates. 相似文献
4.
《Archivos de la Sociedad Espa?ola de Oftalmología》2022,97(8):432-442
PurposeTo develop and evaluate an automated method to measure the foveal avascular zone (FAZ) area in healthy eyes on Heidelberg Spectralis Optical Coherence Tomography Angiography (HS-OCTA). This method is referred to as the modified Kanno-Saitama macro (mKSM) which is an evolution of the Kanno-Saitama macro (KSM) approach.MethodsThis cross-sectional study included 29 eyes of 25 healthy volunteers who underwent HS-OCTA at the macular area twice at the same time. Regardless of the quality of the images, all of them were included. Macular data on the superficial vascular plexus, intermediate capillary plexus (ICP) and deep capillary plexus were processed by mKSM. The FAZ area was measured twice automatically using the mKSM and KSM and twice manually by two independent examiners.ResultsFrom 174 images, KSM could not measure correctly 31% while mKSM could successfully measure all of them. Intrascan intraclass coefficient ranged from 0.948 to 0.993 for manual measurements and was 1 for mKSM method. Despite that the difference between human examiners is smaller than between human examiners and mKSM according to Bland-Altman plots, the scatterplots show a strong correlation between human and automatic measurements. The best results are obtained in ICP.ConclusionsWith mKSM, the automated determination of the FAZ area in HS-OCTA is feasible and less human-dependent. It solves the inability of KSM to measure the FAZ area in suboptimal quality images which are frequent in daily clinical practice. Therefore, the mKSM processing could contribute to our understanding of the three vascular plexuses. 相似文献
5.
6.
7.
《Morphologie : bulletin de l'Association des anatomistes》2022,106(353):136-140
8.
《European journal of surgical oncology》2022,48(3):621-631
ObjectivesThe aim of this meta-analysis was to conduct a contemporary systematic review of high quality non-randomised controlled trials to determine the effect of pre-liver transplantation (LT) transarterial chemoembolisation (TACE) on long-term survival and complications of hepatocellular carcinoma (HCC) patients.BackgroundTACE is used as a neoadjuvant therapy to mitigate waitlist drop-out for patients with HCC awaiting LT. Previous studies have conflicting conclusions on the effect of TACE on long-term survival and complications of HCC patients undergoing LT.MethodsCINAHL, Cochrane Controlled Register of Trials, Embase, PubMed, and Web of Science were systematically searched. Baseline characteristics included number of patients outside Milan criteria, tumour diameter, MELD score, and time on the waiting list. Primary outcomes included 3- and 5-year overall and disease-free survival. Secondary outcomes included tumour recurrence, 30-day postoperative mortality, and hepatic artery and biliary complications.ResultsTwenty-one high-quality NRCTs representing 8242 patients were included. Tumour diameter was significantly larger in TACE patients (3.49 cm vs 3.15 cm, P = 0.02) and time on the waiting list was significantly longer in TACE patients (4.87 months vs 3.46 months, P = 0.05), while MELD score was significantly higher in non-TACE patients (10.81 vs 12.35, P = 0.005). All primary and secondary outcomes displayed non-significant differences.ConclusionPatients treated with TACE had similar survival and postoperative outcomes to non-TACE patients, however, they had worse prognostic features compared to non-TACE patients. These findings strongly support the current US and European clinical practice guidelines that neoadjuvant TACE can be used for patients with longer expected waiting list times (specifically >6 months). Randomised controlled trials would be needed to increase the quality of evidence. 相似文献
9.
Xiao-Long Tang Yan-Dong Miao Deng-Hai Mi 《World journal of gastrointestinal oncology》2022,14(1):366-368
The present letter to the editor is in response to the research “Outcomes of curative liver resection for hepatocellular carcinoma in patients with cirrhosis” by Elshaarawy et al in World J Gastroenterol 2021; 13(5): 424–439. The preoperative assessment of the liver reserve function in hepatocellular carcinoma (HCC) patients with cirrhosis is crucial, and there is no universal consensus on how to assess it. Based on a retrospective study, Elshaarawy et al investigated the impact of various classical clinical indicators on liver failure and the prognosis after hepatectomy in HCC patients with cirrhosis. We recommend that we should strive to explore new appraisal indicators, such as the indocyanine green retention rate at 15 min. 相似文献
10.