全文获取类型
收费全文 | 132048篇 |
免费 | 18501篇 |
国内免费 | 13839篇 |
专业分类
电工技术 | 11625篇 |
技术理论 | 8篇 |
综合类 | 17310篇 |
化学工业 | 11096篇 |
金属工艺 | 4283篇 |
机械仪表 | 9577篇 |
建筑科学 | 12755篇 |
矿业工程 | 4475篇 |
能源动力 | 6066篇 |
轻工业 | 4328篇 |
水利工程 | 8522篇 |
石油天然气 | 7191篇 |
武器工业 | 1990篇 |
无线电 | 10833篇 |
一般工业技术 | 11769篇 |
冶金工业 | 4628篇 |
原子能技术 | 1308篇 |
自动化技术 | 36624篇 |
出版年
2024年 | 741篇 |
2023年 | 2095篇 |
2022年 | 4058篇 |
2021年 | 4643篇 |
2020年 | 4988篇 |
2019年 | 4339篇 |
2018年 | 4158篇 |
2017年 | 5136篇 |
2016年 | 5910篇 |
2015年 | 6148篇 |
2014年 | 8146篇 |
2013年 | 8695篇 |
2012年 | 9674篇 |
2011年 | 10433篇 |
2010年 | 8239篇 |
2009年 | 8540篇 |
2008年 | 8580篇 |
2007年 | 9671篇 |
2006年 | 8368篇 |
2005年 | 7340篇 |
2004年 | 5916篇 |
2003年 | 5178篇 |
2002年 | 4079篇 |
2001年 | 3378篇 |
2000年 | 2935篇 |
1999年 | 2247篇 |
1998年 | 1900篇 |
1997年 | 1562篇 |
1996年 | 1464篇 |
1995年 | 1278篇 |
1994年 | 1043篇 |
1993年 | 740篇 |
1992年 | 612篇 |
1991年 | 481篇 |
1990年 | 383篇 |
1989年 | 322篇 |
1988年 | 199篇 |
1987年 | 129篇 |
1986年 | 99篇 |
1985年 | 98篇 |
1984年 | 103篇 |
1983年 | 47篇 |
1982年 | 66篇 |
1981年 | 35篇 |
1980年 | 48篇 |
1979年 | 47篇 |
1978年 | 16篇 |
1974年 | 9篇 |
1959年 | 17篇 |
1951年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Sarah M. Kedziora Kristin Krker Lajos Mark Julia Binder Meryam Sugulle Martin Gauster Dominik N. Müller Ralf Dechend Nadine Haase Florian Herse 《International journal of molecular sciences》2021,22(7)
Preeclampsia (PE) is characterized by the onset of hypertension (≥140/90 mmHg) and presence of proteinuria (>300 mg/L/24 h urine) or other maternal organ dysfunctions. During human PE, renal injuries have been observed. Some studies suggest that women with PE diagnosis have an increased risk to develop renal diseases later in life. However, in human studies PE as a single cause of this development cannot be investigated. Here, we aimed to investigate the effect of PE on postpartum renal damage in an established transgenic PE rat model. Female rats harboring the human-angiotensinogen gene develop a preeclamptic phenotype after mating with male rats harboring the human-renin gene, but are normotensive before and after pregnancy. During pregnancy PE rats developed mild tubular and glomerular changes assessed by histologic analysis, increased gene expression of renal damage markers such as kidney injury marker 1 and connective-tissue growth factor, and albuminuria compared to female wild-type rats (WT). However, four weeks postpartum, most PE-related renal pathologies were absent, including albuminuria and elevated biomarker expression. Only mild enlargement of the glomerular tuft could be detected. Overall, the glomerular and tubular function were affected during pregnancy in the transgenic PE rat. However, almost all these pathologies observed during PE recovered postpartum. 相似文献
922.
Jin-Xian Liao Yu-Wei Chen Ming-Kuei Shih You-Lin Tain Yao-Tsung Yeh Min-Hsi Chiu Sam K. C. Chang Chih-Yao Hou 《International journal of molecular sciences》2021,22(10)
Resveratrol can affect the physiology or biochemistry of offspring in the maternal–fetal animal model. However, it exhibits low bioavailability in humans and animals. Fifteen-week SD pregnant female rats were orally administered bisphenol A (BPA) and/or resveratrol butyrate ester (RBE), and the male offspring rats (n = 4–8 per group) were evaluated. The results show that RBE treatment (BPA + R30) compared with the BPA group can reduce the damage caused by BPA (p < 0.05). RBE enhanced the expression of selected genes and induced extramedullary hematopoiesis and mononuclear cell infiltration. RBE increased the abundance of S24-7 and Adlercreutzia in the intestines of the male offspring rats, as well as the concentrations of short-chain fatty acids (SCFAs) in the feces. RBE also increased the antioxidant capacity of the liver by inducing Nrf2, promoting the expression of HO-1, SOD, and CAT. It also increased the concentration of intestinal SCFAs, enhancing the barrier formed by intestinal cells, thereby preventing BPA-induced metabolic disruption in the male offspring rats, and reduced liver inflammation. This study identified a potential mechanism underlying the protective effects of RBE against the liver damage caused by BPA exposure during the peri-pregnancy period, and the influence of the gut microbiota on the gut–liver axis in the offspring. 相似文献
923.
Alon M. Douek Mitra Amiri Khabooshan Jason Henry Sebastian-Alexander Stamatis Florian Kreuder Georg Ramm Minna-Liisa nk Donald Wlodkowic Jan Kaslin 《International journal of molecular sciences》2021,22(11)
Mucopolysaccharidosis IIIA (MPS IIIA, Sanfilippo syndrome type A), a paediatric neurological lysosomal storage disease, is caused by impaired function of the enzyme N-sulfoglucosamine sulfohydrolase (SGSH) resulting in impaired catabolism of heparan sulfate glycosaminoglycan (HS GAG) and its accumulation in tissues. MPS IIIA represents a significant proportion of childhood dementias. This condition generally leads to patient death in the teenage years, yet no effective therapy exists for MPS IIIA and a complete understanding of the mechanisms of MPS IIIA pathogenesis is lacking. Here, we employ targeted CRISPR/Cas9 mutagenesis to generate a model of MPS IIIA in the zebrafish, a model organism with strong genetic tractability and amenity for high-throughput screening. The sgshΔex5−6 zebrafish mutant exhibits a complete absence of Sgsh enzymatic activity, leading to progressive accumulation of HS degradation products with age. sgshΔex5−6 zebrafish faithfully recapitulate diverse CNS-specific features of MPS IIIA, including neuronal lysosomal overabundance, complex behavioural phenotypes, and profound, lifelong neuroinflammation. We further demonstrate that neuroinflammation in sgshΔex5−6 zebrafish is largely dependent on interleukin-1β and can be attenuated via the pharmacological inhibition of Caspase-1, which partially rescues behavioural abnormalities in sgshΔex5−6 mutant larvae in a context-dependent manner. We expect the sgshΔex5−6 zebrafish mutant to be a valuable resource in gaining a better understanding of MPS IIIA pathobiology towards the development of timely and effective therapeutic interventions. 相似文献
924.
Gianluca Selvaggio Claudine Chaouiya Florence Janody 《International journal of molecular sciences》2021,22(9)
The multistep development of cancer involves the cooperation between multiple molecular lesions, as well as complex interactions between cancer cells and the surrounding tumour microenvironment. The search for these synergistic interactions using experimental models made tremendous contributions to our understanding of oncogenesis. Yet, these approaches remain labour-intensive and challenging. To tackle such a hurdle, an integrative, multidisciplinary effort is required. In this article, we highlight the use of logical computational models, combined with experimental validations, as an effective approach to identify cooperative mechanisms and therapeutic strategies in the context of cancer biology. In silico models overcome limitations of reductionist approaches by capturing tumour complexity and by generating powerful testable hypotheses. We review representative examples of logical models reported in the literature and their validation. We then provide further analyses of our logical model of Epithelium to Mesenchymal Transition (EMT), searching for additional cooperative interactions involving inputs from the tumour microenvironment and gain of function mutations in NOTCH. 相似文献
925.
随着电动汽车动态无线充电(EV-DWC)技术的发展,针对目前EV-DWC负荷建模理论工作不全面的现状,以交通流量作为影响充电负荷的主要因素,以天气、典型日期、季节等因素为次要影响因素,根据路况建立负荷模型,通过电动汽车型号和状态的聚类不同对汽车分配不同的功率,完成动态充电负荷的建立。采用小波神经网络(WNN)对时序信息进行处理预测,再同误差反向传播神经网络(BPNN)相结合预测充电道路上的车流,短期车流预测精度为85%,用模糊C聚类(FCM)算法对电动汽车的充电类型以及该类型所对应的充电功率进行划分,将进入充电道路的电动汽车分为7种类型。根据各种充电类型分配相应的充电功率,完成日负荷建模。 相似文献
926.
Iris Ribitsch Andrea Bileck Alexander D. Aldoshin Maciej M. Kadua Rupert L. Mayer Monika Egerbacher Simone Gabner Ulrike Auer Sinan Gültekin Johann Huber David P. Kreil Christopher Gerner Florien Jenner 《International journal of molecular sciences》2021,22(11)
Tendinopathies are painful, disabling conditions that afflict 25% of the adult human population. Filling an unmet need for realistic large-animal models, we here present an ovine model of tendon injury for the comparative study of adult scarring repair and fetal regeneration. Complete regeneration of the fetal tendon within 28 days is demonstrated, while adult tendon defects remained macroscopically and histologically evident five months post-injury. In addition to a comprehensive histological assessment, proteome analyses of secretomes were performed. Confirming histological data, a specific and pronounced inflammation accompanied by activation of neutrophils in adult tendon defects was observed, corroborated by the significant up-regulation of pro-inflammatory factors, neutrophil attracting chemokines, the release of potentially tissue-damaging antimicrobial and extracellular matrix-degrading enzymes, and a response to oxidative stress. In contrast, secreted proteins of injured fetal tendons included proteins initiating the resolution of inflammation or promoting functional extracellular matrix production. These results demonstrate the power and relevance of our novel ovine fetal tendon regeneration model, which thus promises to accelerate research in the field. First insights from the model already support our molecular understanding of successful fetal tendon healing processes and may guide improved therapeutic strategies. 相似文献
927.
Arun Pandian Chandrasekaran Sang Hyeon Woo Neha Sarodaya Byung Ho Rhie Apoorvi Tyagi Soumyadip Das Bharathi Suresh Na Re Ko Seung Jun Oh Kye-Seong Kim Suresh Ramakrishna 《International journal of molecular sciences》2021,22(11)
Cell division cycle 25A (Cdc25A) is a dual-specificity phosphatase that is overexpressed in several cancer cells and promotes tumorigenesis. In normal cells, Cdc25A expression is regulated tightly, but the changes in expression patterns in cancer cells that lead to tumorigenesis are unknown. In this study, we showed that ubiquitin-specific protease 29 (USP29) stabilized Cdc25A protein expression in cancer cell lines by protecting it from ubiquitin-mediated proteasomal degradation. The presence of USP29 effectively blocked polyubiquitination of Cdc25A and extended its half-life. CRISPR-Cas9-mediated knockdown of USP29 in HeLa cells resulted in cell cycle arrest at the G0/G1 phase. We also showed that USP29 knockdown hampered Cdc25A-mediated cell proliferation, migration, and invasion of cancer cells in vitro. Moreover, NSG nude mice transplanted with USP29-depleted cells significantly reduced the size of the tumors, whereas the reconstitution of Cdc25A in USP29-depleted cells significantly increased the tumor size. Altogether, our results implied that USP29 promoted cell cycle progression and oncogenic transformation by regulating protein turnover of Cdc25A. 相似文献
928.
负荷功率呈现时空多样的变化特性,其影响因素众多,构建负荷功率模型的关键之一是确定模型的输入特征量。文中着重研究短期负荷功率模型的特征选择,旨在从历史负荷、气象、日期等众多特征中选出最优特征集。首先,采用最大信息系数、基于支持向量机的递归特征消除法和随机森林3种不同特征选择方法分别对输入特征集进行选择;然后,根据对比分析结果提出基于遗传算法的最优特征集搜索策略,选定XGBoost预测模型的误差指标作为适应性函数进行迭代优化搜索;最终,确定负荷功率模型的最优特征输入集。采用某地区220 kV变电站母线负荷数据进行算例分析,对比各方法所选特征集作为功率模型输入得到的负荷预测效果,验证了文中方法的有效性和准确性。 相似文献
929.
Rosalinda Madonna Stefania Moscato Enza Polizzi Damiana Pieragostino Maria Concetta Cufaro Piero Del Boccio Francesco Bianchi Raffaele De Caterina Letizia Mattii 《International journal of molecular sciences》2021,22(11)
Cardiac connexins (Cxs) are proteins responsible for proper heart function. They form gap junctions that mediate electrical and chemical signalling throughout the cardiac system, and thus enable a synchronized contraction. Connexins can also individually participate in many signal transduction pathways, interacting with intracellular proteins at various cellular compartments. Altered connexin expression and localization have been described in diseased myocardium and the aim of this study is to assess the involvement of Cx43, Cx26, and some related molecules in ponatinib-induced cardiac toxicity. Ponatinib is a new multi-tyrosine kinase inhibitor that has been successfully used against human malignancies, but its cardiotoxicity remains worrisome. Therefore, understanding its signaling mechanism is important to adopt potential anti cardiac damage strategies. Our experiments were performed on hearts from male and female mice treated with ponatinib and with ponatinib plus siRNA-Notch1 by using immunofluorescence, Western blotting, and proteomic analyses. The altered cardiac function and the change in Cxs expression observed in mice after ponatinib treatment, were results dependent on the Notch1 pathway and sex. Females showed a lower susceptibility to ponatinib than males. The downmodulation of cardiac Cx43, Cx26 and miR-122, high pS368-Cx43 phosphorylation, cell viability and survival activation could represent some of the female adaptative/compensatory reactions to ponatinib cardiotoxicity. 相似文献
930.
To date, it has been reliably shown that the lipid bilayer/water interface can be thoroughly characterized by a sophisticated so-called “dynamic molecular portrait”. The latter reflects a combination of time-dependent surface distributions of various physicochemical properties, inherent in both model lipid bilayers and natural multi-component cell membranes. One of the most important features of biomembranes is their mosaicity, which is expressed in the constant presence of lateral inhomogeneities, the sizes and lifetimes of which vary in a wide range—from 1 to 103 nm and from 0.1 ns to milliseconds. In addition to the relatively well-studied macroscopic domains (so-called “rafts”), the analysis of micro- and nanoclusters (or domains) that form an instantaneous picture of the distribution of structural, dynamic, hydrophobic, electrical, etc., properties at the membrane-water interface is attracting increasing interest. This is because such nanodomains (NDs) have been proven to be crucial for the proper membrane functioning in cells. Therefore, an understanding with atomistic details the phenomena associated with NDs is required. The present mini-review describes the recent results of experimental and in silico studies of spontaneously formed NDs in lipid membranes. The main attention is paid to the methods of ND detection, characterization of their spatiotemporal parameters, the elucidation of the molecular mechanisms of their formation. Biological role of NDs in cell membranes is briefly discussed. Understanding such effects creates the basis for rational design of new prospective drugs, therapeutic approaches, and artificial membrane materials with specified properties. 相似文献