全文获取类型
收费全文 | 596篇 |
免费 | 23篇 |
专业分类
电工技术 | 9篇 |
综合类 | 1篇 |
化学工业 | 251篇 |
金属工艺 | 5篇 |
机械仪表 | 3篇 |
建筑科学 | 18篇 |
矿业工程 | 2篇 |
能源动力 | 7篇 |
轻工业 | 71篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 40篇 |
一般工业技术 | 81篇 |
冶金工业 | 30篇 |
原子能技术 | 2篇 |
自动化技术 | 97篇 |
出版年
2023年 | 11篇 |
2022年 | 71篇 |
2021年 | 65篇 |
2020年 | 25篇 |
2019年 | 17篇 |
2018年 | 22篇 |
2017年 | 19篇 |
2016年 | 21篇 |
2015年 | 23篇 |
2014年 | 17篇 |
2013年 | 38篇 |
2012年 | 29篇 |
2011年 | 51篇 |
2010年 | 27篇 |
2009年 | 20篇 |
2008年 | 24篇 |
2007年 | 21篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 14篇 |
1997年 | 16篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1988年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有619条查询结果,搜索用时 15 毫秒
1.
Ilaria Fraudentali Renato A. Rodrigues-Pousada Riccardo Angelini Sandip A. Ghuge Alessandra Cona 《International journal of molecular sciences》2021,22(10)
Polyamines are ubiquitous, low-molecular-weight aliphatic compounds, present in living organisms and essential for cell growth and differentiation. Copper amine oxidases (CuAOs) oxidize polyamines to aminoaldehydes releasing ammonium and hydrogen peroxide, which participates in the complex network of reactive oxygen species acting as signaling molecules involved in responses to biotic and abiotic stresses. CuAOs have been identified and characterized in different plant species, but the most extensive study on a CuAO gene family has been carried out in Arabidopsis thaliana. Growing attention has been devoted in the last years to the investigation of the CuAO expression pattern during development and in response to an array of stress and stress-related hormones, events in which recent studies have highlighted CuAOs to play a key role by modulation of a multilevel phenotypic plasticity expression. In this review, the attention will be focused on the involvement of different AtCuAOs in the IAA/JA/ABA signal transduction pathways which mediate stress-induced phenotypic plasticity events. 相似文献
2.
Davide De Biase Giuseppe Piegari Francesco Prisco Ilaria Cimmino Ilaria dAquino Valeria Baldassarre Francesco Oriente Serenella Papparella Orlando Paciello 《International journal of molecular sciences》2021,22(7)
Sarcopenia is defined as the age-related loss of skeletal muscle mass, quality, and strength. The pathophysiological mechanisms underlying sarcopenia are still not completely understood. The aim of this work was to evaluate, for the first time, the expression of NLRP3 inflammasome in bovine skeletal muscle in order to investigate the hypothesis that inflammasome activation may trigger and sustain a pro-inflammatory environment leading to sarcopenia. Samples of skeletal muscle were collected from 60 cattle belonging to three age-based groups. Morphologic, immunohistochemical and molecular analysis were performed to assess the presence of age-related pathologic changes and chronic inflammation, the expression of NLRP3 inflammasome and to determine the levels of interleukin-1β, interleukin-18 and tumor necrosis factor alpha in muscle tissue. Our results revealed the presence of morphologic sarcopenia hallmark, chronic lymphocytic inflammation and a type II fibers-selective NLRP3 expression associated to a significant decreased number of immunolabeled-fibers in aged animals. Moreover, we found a statistically significant age-related increase of pro-inflammatory cytokines such as interleukin-1β and interleukin-18 suggesting the activation of NLRP3 inflammasome. Taken together, our data suggest that NLRP3 inflammasome components may be normally expressed in skeletal muscle, but its priming and activation during aging may contribute to enhance a pro-inflammatory environment altering normal muscular anabolism and metabolism. 相似文献
3.
Adele Boccuto Filippo Dragoni Francesca Picarazzi Alessia Lai Carla Della Ventura Carla Veo Federica Giammarino Francesco Saladini Gianguglielmo Zehender Maurizio Zazzi Mattia Mori Ilaria Vicenti 《International journal of molecular sciences》2021,22(5)
The nucleotide analog sofosbuvir, licensed for the treatment of hepatitis C, recently revealed activity against the Zika virus (ZIKV) in vitro and in animal models. However, the ZIKV genetic barrier to sofosbuvir has not yet been characterized. In this study, in vitro selection experiments were performed in infected human hepatoma cell lines. Increasing drug pressure significantly delayed viral breakthrough (p = 0.029). A double mutant in the NS5 gene (V360L/V607I) emerged in 3 independent experiments at 40–80 µM sofosbuvir resulting in a 3.9 ± 0.9-fold half- maximal inhibitory concentration (IC50) shift with respect to the wild type (WT) virus. A triple mutant (C269Y/V360L/V607I), detected in one experiment at 80 µM, conferred a 6.8-fold IC50 shift with respect to the WT. Molecular dynamics simulations confirmed that the double mutant V360L/V607I impacts the binding mode of sofosbuvir, supporting its role in sofosbuvir resistance. Due to the distance from the catalytic site and to the lack of reliable structural data, the contribution of C269Y was not investigated in silico. By a combination of sequence analysis, phenotypic susceptibility testing, and molecular modeling, we characterized a double ZIKV NS5 mutant with decreased sofosbuvir susceptibility. These data add important information to the profile of sofosbuvir as a possible lead for anti-ZIKV drug development. 相似文献
4.
G. Bartolini A. Ferrara 《International Journal of Adaptive Control and Signal Processing》1992,6(3):237-246
In this paper we pursue a twofold aim. First we want to simplify the complexity of the classical Monopoli's scheme, the so-called ‘Augmented error signal control scheme’. Then we also wish to cope with the realistic situation in which the presence of unmodelled dynamics has to be taken into account. This latter problem has been faced in the literature by suitably modifying the adaptation mechanism in order to avoid undesired phenomena as well as to obtain an attractive stability region for the state trajectories starting from any point in a predefined initial condition set. In our case the necessity of introducing any sort of modification in the adaptation mechanism is completely avoided, but we still obtain asymptotic stability of the output error signal. 相似文献
5.
On the Finite-Time Stabilization of Uncertain Nonlinear Systems With Relative Degree Three 总被引:1,自引:0,他引:1
This technical note discusses a finite-time stabilization problem in a nonlinear, uncertain, environment. The main result of the present note is presented making reference to a triple integrator affected by bounded uncertainties and subject to ldquohardrdquo measurement nonlinearities such that the sign of the state variables is the only reliable information available for feedback. We propose a discontinuous control scheme guaranteeing the practical finite-time annihilation of the three state variables. Constructive proof and computer simulations, as well as guidelines for practical implementations, are provided throughout this technical note. 相似文献
6.
New definitions of approximability are presented for nonlinear second-order sliding mode control systems. Such robustness properties are compared with those already known for first-order methods. Sufficient conditions are obtained for second-order regularization, a sliding error estimate is derived, and some relevant examples are discussed. 相似文献
7.
8.
Neuroprotective Effects of Testosterone in the Hypothalamus of an Animal Model of Metabolic Syndrome
Erica Sarchielli Paolo Comeglio Sandra Filippi Ilaria Cellai Giulia Guarnieri Alessandra Marzoppi Sarah Cipriani Linda Vignozzi Annamaria Morelli Mario Maggi 《International journal of molecular sciences》2021,22(4)
Metabolic syndrome (MetS) is known to be associated to inflammation and alteration in the hypothalamus, a brain region implicated in the control of several physiological functions, including energy homeostasis and reproduction. Previous studies demonstrated the beneficial effects of testosterone treatment (TTh) in counteracting some MetS symptoms in both animal models and clinical studies. This study investigated the effect of TTh (30 mg/kg/week for 12 weeks) on the hypothalamus in a high-fat diet (HFD)-induced animal model of MetS, utilizing quantitative RT-PCR and immunohistochemical analyses. The animal model recapitulates the human MetS features, including low testosterone/gonadotropin plasma levels. TTh significantly improved MetS-induced hypertension, visceral adipose tissue accumulation, and glucose homeostasis derangements. Within hypothalamus, TTh significantly counteracted HFD-induced inflammation, as detected in terms of expression of inflammatory markers and microglial activation. Moreover, TTh remarkably reverted the HFD-associated alterations in the expression of important regulators of energy status and reproduction, such as the melanocortin and the GnRH-controlling network. Our results suggest that TTh may exert neuroprotective effects on the HFD-related hypothalamic alterations, with positive outcomes on the circuits implicated in the control of energy metabolism and reproductive tasks, thus supporting a possible role of TTh in the clinical management of MetS. 相似文献
9.
Prof. Alessia Carocci Dr. Mariagrazia Roselli Prof. Roberta Budriesi Dr. Matteo Micucci Prof. Jean-François Desaphy Dr. Concetta Altamura Dr. Maria Maddalena Cavalluzzi Dr. Maddalena Toma Dr. Giovanna Ilaria Passeri Dr. Gualtiero Milani Dr. Angelo Lovece Prof. Alessia Catalano Dr. Claudio Bruno Dr. Annalisa De Palma Prof. Filomena Corbo Prof. Carlo Franchini Prof. Solomon Habtemariam Prof. Giovanni Lentini 《ChemMedChem》2021,16(3):578-588
Under the hypothesis that cardioprotective agents might benefit from synergism between antiarrhythmic activity and antioxidant properties, a small series of mexiletine analogues were coupled with the 2,2,5,5-tetramethylpyrroline moiety, known for its antioxidant effect, in order to obtain dual-acting drugs potentially useful in the protection of the heart against post-ischemic reperfusion injury. The pyrroline derivatives reported herein were found to be more potent as antiarrhythmic agents than mexiletine and displayed antioxidant activity. The most interesting tetramethylpyrroline congener, a tert-butyl-substituted analogue, was at least 100 times more active as an antiarrhythmic than mexiletine. 相似文献
10.
Ilaria Zuliani Chiara Lanzillotta Antonella Tramutola Eugenio Barone Marzia Perluigi Serena Rinaldo Alessio Paone Francesca Cutruzzol Francesco Bellanti Matteo Spinelli Francesca Natale Salvatore Fusco Claudio Grassi Fabio Di Domenico 《International journal of molecular sciences》2021,22(7)
The disturbance of protein O-GlcNAcylation is emerging as a possible link between altered brain metabolism and the progression of neurodegeneration. As observed in brains with Alzheimer’s disease (AD), flaws of the cerebral glucose uptake translate into reduced protein O-GlcNAcylation, which promote the formation of pathological hallmarks. A high-fat diet (HFD) is known to foster metabolic dysregulation and insulin resistance in the brain and such effects have been associated with the reduction of cognitive performances. Remarkably, a significant role in HFD-related cognitive decline might be played by aberrant protein O-GlcNAcylation by triggering the development of AD signature and mitochondrial impairment. Our data support the impairment of total protein O-GlcNAcylation profile both in the brain of mice subjected to a 6-week high-fat-diet (HFD) and in our in vitro transposition on SH-SY5Y cells. The reduction of protein O-GlcNAcylation was associated with the development of insulin resistance, induced by overfeeding (i.e., defective insulin signaling and reduced mitochondrial activity), which promoted the dysregulation of the hexosamine biosynthetic pathway (HBP) flux, through the AMPK-driven reduction of GFAT1 activation. Further, we observed that a HFD induced the selective impairment of O-GlcNAcylated-tau and of O-GlcNAcylated-Complex I subunit NDUFB8, thus resulting in tau toxicity and reduced respiratory chain functionality respectively, highlighting the involvement of this posttranslational modification in the neurodegenerative process. 相似文献