全文获取类型
收费全文 | 1737篇 |
免费 | 140篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
综合类 | 1篇 |
化学工业 | 749篇 |
金属工艺 | 17篇 |
机械仪表 | 23篇 |
建筑科学 | 60篇 |
矿业工程 | 1篇 |
能源动力 | 40篇 |
轻工业 | 353篇 |
水利工程 | 13篇 |
石油天然气 | 5篇 |
无线电 | 95篇 |
一般工业技术 | 254篇 |
冶金工业 | 60篇 |
原子能技术 | 7篇 |
自动化技术 | 191篇 |
出版年
2024年 | 2篇 |
2023年 | 28篇 |
2022年 | 227篇 |
2021年 | 215篇 |
2020年 | 82篇 |
2019年 | 62篇 |
2018年 | 71篇 |
2017年 | 53篇 |
2016年 | 77篇 |
2015年 | 65篇 |
2014年 | 87篇 |
2013年 | 110篇 |
2012年 | 105篇 |
2011年 | 124篇 |
2010年 | 93篇 |
2009年 | 72篇 |
2008年 | 74篇 |
2007年 | 67篇 |
2006年 | 48篇 |
2005年 | 44篇 |
2004年 | 33篇 |
2003年 | 20篇 |
2002年 | 25篇 |
2001年 | 13篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 20篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 6篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有1878条查询结果,搜索用时 15 毫秒
81.
82.
Francesca Bugli Federica Massaro Francesco Buonocore Paolo Roberto Saraceni Stefano Borocci Francesca Ceccacci Cecilia Bombelli Maura Di Vito Rosalba Marchitiello Melinda Mariotti Riccardo Torelli Maurizio Sanguinetti Fernando Porcelli 《International journal of molecular sciences》2022,23(4)
The increasing resistance of fungi to antibiotics is a severe challenge in public health, and newly effective drugs are required. Promising potential medications are lipopeptides, linear antimicrobial peptides (AMPs) conjugated to a lipid tail, usually at the N-terminus. In this paper, we investigated the in vitro and in vivo antifungal activity of three short myristoylated and non-myristoylated peptides derived from a mutant of the AMP Chionodracine. We determined their interaction with anionic and zwitterionic membrane-mimicking vesicles and their structure during this interaction. We then investigated their cytotoxic and hemolytic activity against mammalian cells. Lipidated peptides showed a broad spectrum of activity against a relevant panel of pathogen fungi belonging to Candida spp., including the multidrug-resistant C. auris. The antifungal activity was also observed vs. biofilms of C. albicans, C. tropicalis, and C. auris. Finally, a pilot efficacy study was conducted on the in vivo model consisting of Galleria mellonella larvae. Treatment with the most-promising myristoylated peptide was effective in counteracting the infection from C. auris and C. albicans and the death of the larvae. Therefore, this myristoylated peptide is a potential candidate to develop antifungal agents against human fungal pathogens. 相似文献
83.
Electrochemical reduction of CO2 is a novel research field towards a CO2-neutral global economy and combating fast accelerating and disastrous climate changes while finding new solutions to store renewable energy in value-added chemicals and fuels. Ionic liquids (ILs), as medium and catalysts (or supporting part of catalysts) have been given wide attention in the electrochemical CO2 reduction reaction (CO2RR) due to their unique advantages in lowering overpotential and improving the product selectivity, as well as their designable and tunable properties. In this review, we have summarized the recent progress of CO2 electro-reduction in IL-based electrolytes to produce higher-value chemicals. We then have highlighted the unique enhancing effect of ILs on CO2RR as templates, precursors, and surface functional moieties of electrocatalytic materials. Finally, computational chemistry tools utilized to understand how the ILs facilitate the CO2RR or to propose the reaction mechanisms, generated intermediates and products have been discussed. 相似文献
84.
Giulia Sierri Roberta Dal Magro Barbara Vergani Biagio Eugenio Leone Beatrice Formicola Lorenzo Taiarol Stefano Fagioli Marcelo Kravicz Lucio Tremolizzo Laura Calabresi Francesca Re 《International journal of molecular sciences》2022,23(1)
The cerebral synthesis of cholesterol is mainly handled by astrocytes, which are also responsible for apoproteins’ synthesis and lipoproteins’ assembly required for the cholesterol transport in the brain parenchyma. In Alzheimer disease (AD), these processes are impaired, likely because of the astrogliosis, a process characterized by morphological and functional changes in astrocytes. Several ATP-binding cassette transporters expressed by brain cells are involved in the formation of nascent discoidal lipoproteins, but the effect of beta-amyloid (Aβ) assemblies on this process is not fully understood. In this study, we investigated how of Aβ1-42-induced astrogliosis affects the metabolism of cholesterol in vitro. We detected an impairment in the cholesterol efflux of reactive astrocytes attributable to reduced levels of ABCA1 transporters that could explain the decreased lipoproteins’ levels detected in AD patients. To approach this issue, we designed biomimetic HDLs and evaluated their performance as cholesterol acceptors. The results demonstrated the ability of apoA-I nanodiscs to cross the blood–brain barrier in vitro and to promote the cholesterol efflux from astrocytes, making them suitable as a potential supportive treatment for AD to compensate the depletion of cerebral HDLs. 相似文献
85.
Anna Martina Tedeschi Fabrizio Di Caprio Antonella Piozzi Francesca Pagnanelli Iolanda Francolini 《International journal of molecular sciences》2022,23(1)
This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC50 value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging. 相似文献
86.
Parastoo Memarian Elham Pishavar Federica Zanotti Martina Trentini Francesca Camponogara Elisa Soliani Paolo Gargiulo Maurizio Isola Barbara Zavan 《International journal of molecular sciences》2022,23(3)
The successful clinical application of bone tissue engineering requires customized implants based on the receiver’s bone anatomy and defect characteristics. Three-dimensional (3D) printing in small animal orthopedics has recently emerged as a valuable approach in fabricating individualized implants for receiver-specific needs. In veterinary medicine, because of the wide range of dimensions and anatomical variances, receiver-specific diagnosis and therapy are even more critical. The ability to generate 3D anatomical models and customize orthopedic instruments, implants, and scaffolds are advantages of 3D printing in small animal orthopedics. Furthermore, this technology provides veterinary medicine with a powerful tool that improves performance, precision, and cost-effectiveness. Nonetheless, the individualized 3D-printed implants have benefited several complex orthopedic procedures in small animals, including joint replacement surgeries, critical size bone defects, tibial tuberosity advancement, patellar groove replacement, limb-sparing surgeries, and other complex orthopedic procedures. The main purpose of this review is to discuss the application of 3D printing in small animal orthopedics based on already published papers as well as the techniques and materials used to fabricate 3D-printed objects. Finally, the advantages, current limitations, and future directions of 3D printing in small animal orthopedics have been addressed. 相似文献
87.
Federico Bolognesi Nicola Fazio Filippo Boriani Viscardo Paolo Fabbri Davide Gravina Francesca Alice Pedrini Nicoletta Zini Michelina Greco Michela Paolucci Maria Carla Re Sofia Asioli Maria Pia Foschini Antonietta DErrico Nicola Baldini Claudio Marchetti 《International journal of molecular sciences》2022,23(3)
Defects of the peripheral nervous system are extremely frequent in trauma and surgeries and have high socioeconomic costs. If the direct suture of a lesion is not possible, i.e., nerve gap > 2 cm, it is necessary to use grafts. While the gold standard is the autograft, it has disadvantages related to its harvesting, with an inevitable functional deficit and further morbidity. An alternative to autografting is represented by the acellular nerve allograft (ANA), which avoids disadvantages of autograft harvesting and fresh allograft rejection. In this research, the authors intend to transfer to human nerves a novel technique, previously implemented in animal models, to decellularize nerves. The new method is based on soaking the nerve tissues in decellularizing solutions while associating ultrasounds and freeze–thaw cycles. It is performed without interrupting the sterility chain, so that the new graft may not require post-production γ-ray irradiation, which is suspected to affect the structural and functional quality of tissues. The new method is rapid, safe, and inexpensive if compared with available commercial ANAs. Histology and immunohistochemistry have been adopted to evaluate the new decellularized nerves. The study shows that the new method can be applied to human nerve samples, obtaining similar, and, sometimes better, results compared with the chosen control method, the Hudson technique. 相似文献
88.
Atom transfer radical polymerization (ATRP) is a staple technique for the preparation of polymers with well-defined architecture. In ATRP, the catalyst governs the equilibrium between propagating radicals and dormant species, thus affecting the polymerization control for a range of monomers and transferable atoms employed in the process. The design and the use of highly active catalysts could diminish the amount of transition metal complexes, extend ATRP to less active monomers and give access to new chain-end functionalities. At the same time, very active catalysts can be involved in formation of organometallic species. Herein, the role of the catalyst on the ATRP equilibrium is carefully elucidated, together with recent observations on the impact of the catalyst nature on formation of organometallic species and relevant side reactions. Based on this knowledge, a perspective on the benefits and challenges that derive from the use of highly active ATRP catalysts is presented. 相似文献
89.
Dr. Markella Konstantinidou Francesca Magari Fandi Sutanto Dr. Jörg Haupenthal Dr. Varsha R. Jumde Dr. M. Yagiz Ünver Prof. Dr. Andreas Heine Dr. Carlos Jamie Camacho Prof. Dr. Anna K. H. Hirsch Prof. Dr. Gerhard Klebe Prof. Dr. Alexander Dömling 《ChemMedChem》2020,15(8):680-684
Pharmacophore searches that include anchors, fragments contributing above average to receptor binding, combined with one-step syntheses are a powerful approach for the fast discovery of novel bioactive molecules. Here, we are presenting a pipeline for the rapid and efficient discovery of aspartyl protease inhibitors. First, we hypothesized that hydrazine could be a multi-valent warhead to interact with the active site Asp carboxylic acids. We incorporated the hydrazine anchor in a multicomponent reaction and created a large virtual library of hydrazine derivatives synthetically accessible in one-step. Next, we performed anchor-based pharmacophore screening of the libraries and resynthesized top-ranked compounds. The inhibitory potency of the molecules was finally assessed by an enzyme activity assay and the binding mode confirmed by several soaked crystal structures supporting the validity of the hypothesis and approach. The herein reported pipeline of tools will be of general value for the rapid generation of receptor binders beyond Asp proteases. 相似文献
90.
Potent,Metabolically Stable 2‐Alkyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐adenines as Adenosine A2A Receptor Ligands 下载免费PDF全文
Dr. Silvia Pace Dr. Giandomenico Brogin Dr. Maria Antonietta Stasi Dr. Teresa Riccioni Franco Borsini Dr. Francesca Capocasa Dr. Francesco Manera Carlo Tallarico Dr. Pietro Grossi Dr. Federica Vacondio Dr. Michele Bassi Dr. Francesca Bartoccini Dr. Simone Lucarini Dr. Giovanni Piersanti Prof. Giorgio Tarzia Walter Cabri Dr. Patrizia Minetti 《ChemMedChem》2015,10(7):1149-1152
Inhibition of adenosine A2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A2AR (Ki=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours). 相似文献