全文获取类型
收费全文 | 55349篇 |
免费 | 5783篇 |
国内免费 | 4066篇 |
专业分类
耳鼻咽喉 | 510篇 |
儿科学 | 810篇 |
妇产科学 | 863篇 |
基础医学 | 6278篇 |
口腔科学 | 905篇 |
临床医学 | 7017篇 |
内科学 | 8035篇 |
皮肤病学 | 561篇 |
神经病学 | 2754篇 |
特种医学 | 1969篇 |
外国民族医学 | 31篇 |
外科学 | 6216篇 |
综合类 | 9720篇 |
现状与发展 | 15篇 |
一般理论 | 6篇 |
预防医学 | 3963篇 |
眼科学 | 1189篇 |
药学 | 5802篇 |
62篇 | |
中国医学 | 3444篇 |
肿瘤学 | 5048篇 |
出版年
2024年 | 190篇 |
2023年 | 928篇 |
2022年 | 2196篇 |
2021年 | 3296篇 |
2020年 | 2463篇 |
2019年 | 1974篇 |
2018年 | 2097篇 |
2017年 | 1976篇 |
2016年 | 1806篇 |
2015年 | 2833篇 |
2014年 | 3410篇 |
2013年 | 3214篇 |
2012年 | 4467篇 |
2011年 | 4745篇 |
2010年 | 3148篇 |
2009年 | 2478篇 |
2008年 | 2977篇 |
2007年 | 2899篇 |
2006年 | 2680篇 |
2005年 | 2647篇 |
2004年 | 1673篇 |
2003年 | 1562篇 |
2002年 | 1411篇 |
2001年 | 1135篇 |
2000年 | 1029篇 |
1999年 | 1003篇 |
1998年 | 652篇 |
1997年 | 634篇 |
1996年 | 511篇 |
1995年 | 466篇 |
1994年 | 390篇 |
1993年 | 218篇 |
1992年 | 335篇 |
1991年 | 273篇 |
1990年 | 237篇 |
1989年 | 210篇 |
1988年 | 233篇 |
1987年 | 164篇 |
1986年 | 149篇 |
1985年 | 108篇 |
1984年 | 66篇 |
1983年 | 54篇 |
1982年 | 39篇 |
1981年 | 31篇 |
1980年 | 28篇 |
1979年 | 34篇 |
1978年 | 18篇 |
1977年 | 12篇 |
1971年 | 13篇 |
1970年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Ecotoxicology - Soil heavy metal pollution evaluations are a necessary measure for mine ecological control projects. In this study, the heavy metals Pb, Zn and Cd were studied in mining areas,... 相似文献
2.
Background: Breast cancer (BC) is the most common malignant tumor in women, and its morbidity and mortality are
increasing each year, due to the lack of specific clinical symptoms in the early stage of BC, and the lack of diagnostic
methods for early breast cancer. Therefore, identifying an effective diagnostic method for early BC has become urgent.
Materials and Methods: Breast lesions with a histological diagnosis that were examined by ultrasonic elastography
(UE) in our department from June 2020 to December 2021 were reviewed. qRT-PCR was performed to measure
the expression levels of miR-144-5p and miR-26b-5p in the plasma of patients with BC. The receiver operating characteristics (ROC) curve and area under the curve (AUC) were used to investigate the potential diagnostic value of miR-
144-5p, miR-26b-5p and the elastographic score in BC. Results: The ultrasonic elastography score(UES) was found to
be significantly upregulated in BC compared with that in benign breast lesions, and the AUC, sensitivity and specificity
were 0.809, 0.717 and 0.806 for distinguishing BC from benign breast lesions, respectively. miR-144-5p and miR-26b-
5p were found to be upregulated in the plasma of BC patients, and miR-144-5p+miR-26b-5p had 0.781 sensitivity and
0.780 specificity for the diagnosis of BC. Furthermore, we found that the diagnostic performance of miR-144-5p and
miR-26b-5p combined with UES for BC had 0.913 sensitivity and 0.890 specificity. Conclusions: The combination of
plasma miR-144-5p, miR-26b-5p and UES has a very high clinical application value for the early detection of BC. 相似文献
3.
痛情绪是指因疼痛引发的情绪和情感体验,是疾病过程中最常见的一种情绪。痛情绪相关神经机制非常复杂,但主要与单胺类神经递质、神经肽和某些神经环路有关,笔者将结合目前研究现状分别从以上两方面展开,就痛情绪相关单胺类神经递质和神经肽在受体分类、脑区通路、共疾病以及各神经递质之间的联系和痛情绪相关神经环路中各个蛋白的作用机制等方面进行探讨。 相似文献
4.
Wuteng Cao Huabin Hu Jiao Li Qianyu Wu Lishuo Shi Biao Li Jie Zhou Xinhua Wang Junhong Chen Chao Wang Huaiming Wang Weihao Deng Yan Huang Yanhong Deng 《International journal of cancer. Journal international du cancer》2023,153(11):1894-1903
Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy. 相似文献
5.
宫腔积液指宫腔内液体积存(积水、积血或积脓),是绝经后女性常见体征之一,常于超声检查时发现。持续宫腔积液患者,需宫腔镜检查寻找病因。本文报道1例以宫腔积液为首发症状,经宫腔镜检查确诊为胃型宫颈腺癌的患者。通过病例回顾并文献复习,以期为更多绝经后宫腔积液及宫颈病变的诊断提供参考,避免漏诊及误诊。1病例资料患者67岁,女,主因"绝经18年,不规则阴道出血2月"于2020年5月就诊于首都医科大学附属北京妇产医院妇科微创中心。 相似文献
6.
Zeyu Li Erwei Hao Rui Cao Si Lin Linghui Zou Tianyan Huang Zhengcai Du Xiaotao Hou Jiagang Deng 《中草药(英文版)》2022,14(4):479-493
Zedoary tumeric (Curcumae Rhizoma, Ezhu in Chinese) has a long history of application and has great potential in the treatment of liver cancer. The anti liver cancer effect of zedoary tumeric depends on the combined action of multiple pharmacodynamic substances. In order to clarify the specific mechanism of zedoary tumeric against liver cancer, this paper first analyzes the mechanism of its single pharmacodynamic substance against liver cancer, and then verifies the joint anti liver cancer mechanism of its "pharmacodynamic group". By searching the research on the anti hepatoma effect of active components of zedoary tumeric in recent years, we found that pharmacodynamic substances, including curcumol, zedoarondiol, curcumenol, curzerenone, curdione, curcumin, germacrone, β-elemene, can act on multi-target and multi-channel to play an anti hepatoma role. For example, curcumin can regulate miR, GLO1, CD133, VEGF, YAP, LIN28B, GPR81, HCAR-1, P53 and PI3K/Akt/mTOR, HSP70/TLR4 and NF-κB. Wnt/TGF/EMT, Nrf2/Keap1, JAK/STAT and other pathways play an anti hepatoma role. Network pharmacological analysis showed that the core targets of the "pharmacodynamic group" for anti-life cancer are AKT1, EGFR, MAPK8, etc, and the core pathways are neuroactive live receiver interaction, nitrogen metabolism, HIF-1 signaling pathway, etc. At the same time, by comparing and analyzing the relationship between the specific mechanisms of pharmacodynamic substance and "pharmacodynamic group", it is found that they have great reference significance in target, pathway, biological function, determination of core pharmacodynamic components, formation of core target protein interaction, in-depth research of single pharmacodynamic substance, increasing curative effect and so on. By analyzing the internal mechanism of zedoary tumeric pharmacodynamic substance and "pharmacodynamic group" in the treatment of liver cancer, this paper intends to provide some ideas and references for the deeper pharmacological research of zedoary tumeric and the relationship between pharmacodynamic substance and "pharmacodynamic group". 相似文献
7.
ObjectiveEach pulmonary segment is an anatomical and functional unit. However, it is fundamentally difficult to precisely distinguish every pulmonary segment using the conventional pulmonary intersegmental planes from computed tomography images. Building arteriopulmonary segments is likely to be an effective way to identify pulmonary segments.MethodsThe thoracic computed tomography images of 40 patients were collected. The anatomic structures of interest were extracted in the transverse, sagittal, and coronal planes using the semi-automated segmentation tools provided by Amira software. The intrapulmonary vessels were subsequently segmented and reconstructed. The distributions of the pulmonary arteries, veins, and bronchi were observed. In patients with pulmonary masses, the mass was also reconstructed.ResultsThe three-dimensional reconstructed images showed the branches of the pulmonary artery ramified up to their eighth order covering the entire lung as well as evident intersegmental gaps without pulmonary arteries. The segmental artery was closely accompanied by the segmental bronchi in 486 pulmonary segments (90% of total number of segments). The size and spatial location of the pulmonary mass within a pulmonary segment were also clearly visible.ConclusionsDemarcation of arteriopulmonary segments can be used to precisely distinguish every pulmonary segment and provide its detailed anatomical structure before pulmonary segmentectomy. 相似文献
8.
9.
Janitz Amanda E. Schraw Jeremy M. Xu Chao Lupo Philip J. 《Cancer causes & control : CCC》2022,33(3):483-488
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among... 相似文献
10.
宫腔积液指宫腔内液体积存(积水、积血或积脓),是绝经后女性常见体征之一,常于超声检查时发现。持续宫腔积液患者,需宫腔镜检查寻找病因。本文报道1例以宫腔积液为首发症状,经宫腔镜检查确诊为胃型宫颈腺癌的患者。通过病例回顾并文献复习,以期为更多绝经后宫腔积液及宫颈病变的诊断提供参考,避免漏诊及误诊。1病例资料患者67岁,女,主因"绝经18年,不规则阴道出血2月"于2020年5月就诊于首都医科大学附属北京妇产医院妇科微创中心。 相似文献