Chitosan-hydroxyapatite composite doped with strontium was synthesised via in situ co-precipitation method. Physicochemical properties of the composite obtained were analysed using X-ray diffraction (XRD), infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and Thermogravimetry with differential thermal analysis (DT-TGA). The synthesised composite was subjected to bioactivity studies in simulated body fluid (SBF). The calcium release from the sample in SBF was measured using atomic absorption spectroscopy (AAS). The physicochemical properties and bioactivity of the novel composite was compared with that of hydroxyapatite, strontium doped hydroxyapatite and chitosan hydroxyapatite. The in vitro bioactivity studies of the novel composite showed that it has a higher release of Ca2+ in the SBF compared to the other samples. The novel material was also found to induce more Ca2+ deposition after 28 days of immersion in.....

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A convenient and simple radical cation cyclisation of 3,5-dimethoxystilbene was developed using the commercially available FeCl3under mild condition. It enabled the construction of a new class of indolostilbenes (i.e., indole-stilbene hybrid). Various parameters were investigated to obtain better yields (more than 42%) compared with the previously reported. The synthesised indolostilbenes were characterised, and their mechanism of formation was discussed. The synthesised compounds were submitted for biological assay on NG108-15 cell viability and H2O2-induced cytotoxicity. The result showed that two indolostilbenes have promising protective activity against H2O2. ? Penerbit Universiti Sains Malaysia, 2021. This work is licensed under the terms of the Creative Commons Attribution (CC BY) (http://creativecommons.org/licenses/by/4.0/)...

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Green synthesis of gamma alumina (?-Al2O3) nanoparticles (NPs) with facetted and cubeoctahedral morphologies was undertaken from waste (beverage aluminium cans) via precipitation technique and calcination at the temperature of 1000oC. The structural properties of ?-Al2O3 were determined with a combination of techniques including BET surface area, field emission scanning electron microscopy (FESEM) with energy dispersive x-ray spectroscopy (EDX), transmission electron microscopy (TEM) and x-ray powder diffraction (XRD). XRD analysis confirmed the formation of ?-Al2O3 NPs by comparing with the standard of ?-Al2O3 structure. The BET surface area measured was 129 m2/g. High-resolution transmission electron microscopy (HRTEM) analysis provided evidence of surface-enhanced contrast in facetted ?-Al2O3 NPs structures similar to the commercial ?-Al2O3 NPs. ? Malaysian Journal of Microscopy (2021). All rights reserved...

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Background: Environmental contamination by microbes is a major public health concern. A damp environment is one of the potential sources for microbe proliferation. Smart synthesis nanocatalytic coatings on surfaces, food, and material from different pathogen bacteria can inhibit using the Fe3O4/CNTs as anti-microbial growth can effectively curb this growing threat. In this present work, the anti-microbial efficacy of synthesis of a compound nanoparticle-containing iron oxide-multi-walled carbon nanotube was combined by laser ablation PLAL and explored the anti-bacterial action of colloidal solution of Fe3O4/CNTs NPs that was evaluated against bacteria which is classified as gram-negative (Escherichia coli (E. coli), Klebsiella pneumonia (K. pneumonia), and also that is identified as gram-positive (Streptococcus pyogenes (S.pyogenes) and Staphylococcus aureus (S. aureus) under visible light irradiation. Results: Doping of a minute fraction of iron(III) salt (0.5 mol%) in a volatile solv.....

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The potentiality of Pt and MoO3 loading on HBEA zeolite in enhancing n-heptane isomerization was investigated. The multiple characterization techniques revealed the engagement of Pt and MoO3 on the lattice or defect structures of the HBEA framework. Furthermore, the occurrence of dealumination was confirmed by the existence of hydrated aluminium-molybdate, Al2-(MoO4)3. These findings proposed the presence of strong metal-support interactions. The n-heptane isomerization was comparatively investigated over Pt and MoO3 modified catalysts, and significantly higher rate of n-heptane conversion (0.059 ?mol/g-cat m2 s) and rate of iso-heptane formation (0.026 ?mol/g-cat m2 s) were achieved with Pt/MoO3-HBEA catalyst. The catalytic performance followed the order of Pt/MoO3-HBEA > MoO3-HBEA > Pt-HBEA > HBEA. It is anticipated that the results of in-situ FTIR studies of low-temperature hydrogen adsorption and n-heptane adsorption analyses help elucidate the isomerization mechanism and indicated.....

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Surface modification techniques have been proven to enhance resistance towards corrosion, to slow the process of wearing, to reduce metal ions release, as well as the process of biomaterial osseointegration. Not only that, these techniques could extend the longevity in materials related to implant, primarily because of its response towards the host of body. Generally, these techniques can be further broken down into physical, mechanical, and chemical approaches. As such, this paper presents further information pertaining to the numerous types of methods for modifying surfaces, along with their benefits and drawbacks. Additionally, several other significant aspects are detailed as well in this paper, for example, the materials and biomaterials used for implant, as well as a number of issues concerning the usage of alloy, biomaterial and titanium. ? 2018 Elsevier Inc. All rights reserved...

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Mobile devices have been utilized as an emerging learning tool in the 21st century to support the learning of chemistry. This study aimed to identify matriculation students? learning experience with regards to the use of mobile devices for learning chemistry. The study employed a qualitative case study approach, which was carried out in a matriculation college. Online diaries and interviews were utilized as the instruments of the study. A total of 84 students initially reflected their learning journey using an online diary, whereas 17 students who were active in mobile learning were purposely selected for the interview. The findings revealed that students have positive and negative experiences towards the use of mobile devices for learning chemistry. They positively perceived that using a mobile device for learning chemistry promotes knowledge construction, visualization of abstract concepts, self-control in learning and intellectual discourse. However, the issue of learning resources .....

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Intercalation of 4-amino benzoic acid (4-AB) into Zn/Al-nitrate layered double hydroxide (ZAL2) to form Zn/Al-4AB (ZALAB) compound was successfully synthesized from nitrate salt by using direct co-precipitation method. ZALAB compound was confirmed by Powder X-ray diffraction (PXRD) pattern with a basal spacing of 15.3 �. The presence of COO- and C6H5NH2 functional groups of 4-AB at 1,517 and 1,178 cm?1 in Fourier transform infrared (FTIR) spectrum reinforced 4-AB intercalated into the resulting compound. Based on the thermal analysis, 4-AB in ZALAB compound was more stable compared to pure 4-AB. Breuneur, Emmet and Teller/Barret-Joyner-Halenda (BET/BJH) analyses demonstrated that ZALAB compound is a mesopores-type IV compound with 4.25 m2/g surface area. This material is an irregular shape with different sizes of particles. ZALAB is a potential sunscreen formulation that minimizes the harmful effect on the skin, improving pharmaceutical technology in the skincare treatment. ? 2021, W.....

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[No abstract available]..

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This research develops instructional media in the form of steam-powered boats in STEM learning in elementary schools to support thematic learning in Indonesia. This development aims to help students acquire the skills that match the science and technology of the twenty-first century. The STEM approach is applied so that students can learn and explore various types of integrated interdisciplinary learning. This research aims to: (1) describe the urgency of using the steampowered boat instructional media in STEM learning, (2) develop and describe the final products of the instructional media, and (3) describe the results of the instructional media trials. The research design used was education-based research with the generic model of Educational Design Research (EDR), which involved students and teachers in the trial process. The data collection techniques used were interviews with teachers and students regarding the need for instructional media in STEM learning, observations of the lear.....

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