830 research outputs found
Graphene – material of the future
This article contains a literature review of research results which are conducted on newly discovered material graphene. Article presents most popular method of its production. Moreover, were presented and discussed so far known properties and areas of application (with practical examples of application). This article presents also the main directions of further research and its possible influence on the future of technology
Engineering Properties of Ternary Cementless Blended Materials
A new non-cement blended materials is developed as a full replacement of cement without alkali activator. This study was conducted to explore a suitable method for activating new ternary green materials with desulfurization gypsum, water-quenched blast-furnace slag and co-fired fly ash from circulating fluidized bed combustion as non-cement inorganic binder. Test subject was included flowability, compressive strength, absorption, total charge-passed from rapid chloride permeability test, chloride diffusion coefficient from accelerated chloride migration test and SEM observation. Test results indicate that a ternary mixture containing 1% desulfurization gypsum, 60% water-quenched blast-furnace slag and 39% co-fired fly ash was a suitable development in compressive strength. The new non-cement blended materials were performed a well compressive strength, lower absorption, and lower chloride diffusion coefficient. In addition, the compressive strength decreased as the inclusion of desulfurization gypsum increased. It was concluded that using desulfurization gypsum alone decreased the setting time and compressive strength. SEM micrographs were verified the development in compressive strength originated from the C-S-H and C-A-S-H gel produced by Ca(OH)2, SiO2, and Al2O3
Search for potential cholinesterase inhibitors from the zinc database by virtual screening method
A virtual screening of the ZINC database was applied for the identification of novel cholinesterase inhibitors. The first step allowed to select compounds with favorable physicochemical properties. Then, the compounds were screened with the pharmacophore models built using crystal structures of donepezil, tacrine, decamethonium and bis-7-tacrine with acetylcholinesterase and well characterized interactions of bis-nor meptazinol with butyrylcholinesterase. The selected compounds from the group of donepezil were docked to acetylcholinesterase giving 7 structures for further studies. These compounds were tested against cholinesterases and two of them, 1-[4-(1H-indol-3-ylmethyl)piperazin-1-yl]-2-phenoxyethanone 2 and 2-[(1-benzylpiperidine-4 yl)amino]-1-phenylethanol 4 displayed, respectively, 50.1% and 79.5% of inhibition against butyrylcholinesterase at the concentration of 100 μM
Application of intravoxel incoherent motion (IVIM) model for differentiation between metastatic and non-metastatic head and neck lymph nodes
Background: Application of intravoxel incoherent motion (IVIM) model parameters, including: true diffusion (D), pseudodiffusion (D*), and perfusion fraction (Fp), for differentiation between metastatic and non-metastatic head and neck lymph nodes. Material/Methods: Diffusion-weighted images/apparent diffusion coefficient (DWI/ADC) images of 86 lymph nodes from 31 cancer patients were analyzed. DWI images were obtained with a 1.5T MRI scanner (Magnetom Avanto); b=0,50, 150, 300, 500, 750, 1000, 1200 s/mm2. Results: In the study group, there were 32 (37%) and 54 (67%) metastatic and non-metastatic lymph nodes, respectively. The mean values of D, D*, and Fp did not differ significantly between metastatic and non-metastatic lymph nodes. Conclusions: IVIM parameters are not useful for differentiation between metastatic and non-metastatic head and neck lymph nodes
Article Improving the Dimensional Stability and Mechanical Properties of AISI 316L + B Sinters by Si3N4 Addition
The following paper describes a new and effective method to obtain high-density sinters with simultaneously decreased distortions, produced by one press and sinter operation. This effect was achieved through the induced disappearance of the eutectic liquid phase. The study was carried out on AISI 316L stainless steel powder that was mixed with elemental boron and silicon nitride. Boron was used as a sintering process activator. The scientific novelty of this publication consists of the use of a silicon nitride as a solid-state nitrogen carrier that was intended to change the borides’ morphology by binding boron. Based on the thermodynamic calculations, 20 blends of various compositions were tested for physical properties, porosity, microstructure, and mechanical properties. Moreover, phase compositions for selected samples were analyzed. It was shown that the addition of silicon nitride as a nitrogen carrier decreases the boron-based eutectic phase volume and both increases the mechanical properties and decreases after-sintering distortions. An explanation of the observed phenomena was also proposed
Synthesis, molecular modelling and biological evaluation of novel heterodimeric, multiple ligands targeting cholinesterases and amyloid beta
Cholinesterases and amyloid beta are one of the major biological targets in the search for a new and efficacious treatment of Alzheimer’s disease. The study describes synthesis and pharmacological evaluation of new compounds designed as dual binding site acetylcholinesterase inhibitors. Among the synthesized compounds, two deserve special attention—compounds 42 and 13. The former is a saccharin derivative and the most potent and selective acetylcholinesterase inhibitor (EeAChE IC50 = 70 nM). Isoindoline-1,3-dione derivative 13 displays balanced inhibitory potency against acetyl- and butyrylcholinesterase (BuChE) (EeAChE IC50 = 0.76 μM, EqBuChE IC50 = 0.618 μM), and it inhibits amyloid beta aggregation (35.8% at 10 μM). Kinetic studies show that the developed compounds act as mixed or non-competitive acetylcholinesterase inhibitors. According to molecular modelling studies, they are able to interact with both catalytic and peripheral active sites of the acetylcholinesterase. Their ability to cross the blood-brain barrier (BBB) was confirmed in vitro in the parallel artificial membrane permeability BBB assay. These compounds can be used as a solid starting point for further development of novel multifunctional ligands as potential anti-Alzheimer’s agents
Development of 3D Printing Technology for Geopolymers
The article presents the first results of the project under the title: ‘Development of 3D printing technology for construction and facade prefabricated elements made of concrete composites and geopolymers’, grant no. POIR.04.01.04-00-0096/18, funded by the National Centre for Research and Development in Poland, within the framework of programme: ‘Smart Growth Operational Programme 2014-2020, IV Increasing the research potential, 4.1.4: ‘Application projects’. The main aim of the project is design and development of the innovative large-format printer using geopolymers for 3D printing for residential houses. It allows the development of a technology for the production of a universal residential building, with a construction that is easy to transport and fast to assemble, as well as with the possibility of simple and quick expansion depending on the needs of users. The article shows the main idea of the advanced large format 3D printing for geopolymers with using an ergonomic printing method as well as materials research in modern filaments in the form of geopolymers
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