Piezoelectric poly(vinyliden fluoride) (PVDF) is attractive because of their low cost, lightweight, biocompatibility and superior mechanical flexibility. Electrophoretic deposition (EPD) technique has the capability of conformally deposit PVDF film on uneven surface target. Nevertheless, knowledge of the role of dispersion formulating process is crucial for achieving an even and uniform PVDF film. Sedimentation test showed PVDF polymer dispersions are more stable and well-dispersed in DMF than in MEK media. For MEK-based dispersion, higher stirring temperature produced less stable and more agglomerated PVDF dispersion, whereas longer stirring time reduced the degree of the PVDF polymer agglomeration. More stable DMF-based dispersions produced lower PVDF depositions than the less stable MEK-based dispersions. PVDF dispersions with higher degree of agglomeration produced films with higher surface roughness and porosity feature.
Accumulation of reactive oxygen species leads to oxidative stress condition that can accelerate ovarian aging. Ovarian aging caused a reduction in plasma estradiol levels, quality of embryo and eventually will lead to infertility. Tocotrienol has been proven to possess antioxidant properties by protecting the cellular membrane from free radicals damage. Therefore, the aim of this study was to determine the effect of tocotrienol supplementation on the plasma estradiol levels, quality and development of embryos in aging mice. Female mice (Mus musculus) used in this study were divided into six groups. Six weeks old mice (young group) were used as negative control while eight months old mice (aging group) were used as age-matched (positive control) group. Group 1 (6 months old mice) were given corn oil as control, group 2, 3 and 4 (6 months old mice) were supplemented orally for two months with tocotrienol (TCT) at the dose of 90, 120 and 150 mg/kg body weight (BW), respectively. Subsequently, after two months the mice were superovulated, euthanized and 2- cell stage embryos were harvested and cultured in vitro to monitor the embryonic development. Plasma was analysed using enzyme-like immunosorbent assay. The results of this study showed that there was no significant correlation between plasma estradiol levels and the quality of embryo between young and aging group. Similarly, no significant change on plasma estradiol levels were noted in all TCT supplemented groups as compared to its vehicle control. On the other hand, there was a significant reduction on the percentage of normal embryo in all aging groups including TCT supplemented groups as compared to young group. Conversely, TCT supplementation at the dose of 150 mg/kg BW was able to increase the percentage of embryos that developed to blastocyst stage as compared to control. This finding proposed that TCT supplementations for two months are not able to cause a significant change in plasma estradiol levels and quality of embryo but it can delay the consequence of aging in embryonic development.
The objective of the present study is to evaluate the effect of incorporation of 3- acetylcoumarin (3-AC), an antibacterial agent, on the mechanical and surface morphology of glass ionomer cement (GIC). A conventional GIC, Fuji II LC, was used as a control. 3-AC was incorporated into GIC during its manipulation at percentage of 2% and 5% (wt/wt). Flexural strength of the specimens were analysed using Shimadzu AGX-Plus while morphological evaluation of the specimens were observed using Scanning Electron Microscope (SEM). Oneway analysis (ANOVA) with post-hoc Bonferroni multiple-range test was used to determine the significant differences among the groups. Statistically, the incorporation of 2% (wt/wt) of 3-AC into GIC showed a significantly lower flexural strength (p
The objective of the study was to asses the adhesion of Streptococcus mutans on nanofilled and microfilled composite resin and glass ionomer cement restorative materials. Glass ionomer cements; KetacTM N100 (nanofilled) and Fuji IITM LC (microfilled) and composite resins; FiltekTM Z350 (nanofilled) and FiltekTM Z250 (microhybrid) were packed in acrylic mould of 2 mm thickness and 5 mm diameter. All samples were light-cured and polished with Sof-Lex discs. All materials were cultured with the exponential phase of S. mutans cultivation. Surface roughness values were assessed using Atomic Force Microscope (AFM, Ambios, USA) at time intervals (7hrs, 24 hrs, 7 days, 14 days and 21 days). The morphology of S. mutans on materials was observed after 24 hour incubation of S. mutan on materials under Scanning Electron Microscope (SEM, Quanta FEG 450). Within groups, results showed that both nanofilled materials had lower surface roughness and less adhesion of S. mutans compared to microfilled materials. This study would enhance the clinical knowledge especially in aesthetic area and improve the longevity of the dental restoration.
Acanthaster planci, a marine starfish is a major management issue on geochemical signatures coral reefs. Attempts to tap into the vast potential of these marine invertebrates as exploitable innovative sources of bioactive metabolites that may or can be directly utilized as drugs or serve as lead structures for drug development and neutraceuticals have been intensified. Such probing effort are based on purported reports and folk medicine that indicate most of these exploitable marine based natural products are believed to be mainly accumulated in most local iconic geochemical signatures marine invertebrates’ biomass such as within the echinoderm, sponges, tunicates, bryozoans, and molluscs. However, little is known on local Malaysia Acanthaster planci or crown of thorns (COTS) biomass actual inert biocompounds profile and its related tangibilities, for a sustainable commercial optimization and exploitation in health related agendas or therapeutic application. This manuscript will thus highlights present research efforts of pertinent to local Malaysia geochemical signature invertebrates Acanthaster planci‘s potential from a once wasted predator biomass to as this said millennium, wealth generated medical and pharmaceutical-therapeutics’ development targeted agenda.
Silicon dioxide (SiO2) has been extensively studied due to their unique properties that make it desirable for many applications ranging from electronic, catalysis, pigment as well as sensors. Multitude of methods and processes are established with the ability to manipulate and control the key properties that can cater for specific applications. Stober method is a very simple and easy for up-scale production of SiO2. This paper presents the experimental study on the effect of synthesis parameter on the morphology of SiO2 synthesized via Stober method. Three parameters were investigated such as concentration of catalyst, concentration of precursor and percentage of water content. The obtained samples were characterized using scanning electron microscopy (SEM) analysis. The findings showed that the size of particles produced is dependent on the synthesis parameter. In this study, particles size ranging from 50 nm to >100 nm are easily produced. The sphere size of SiO2 can be increased by increasing the concentration of ammonia hydroxide catalyst, the concentration of TEOS, as well as the percentage of water content.
The chemical composition and anatomical characteristics on lignin distribution of rattan waste were analyzed to determine its suitability to be used in binderless board fabrication. The chemical composition was analyzed by using TAPPI methods. Observation and determination of lignin distribution and board structure were executed by using optical microscopy (OM) and scanning electron microscope (SEM). High amount of hemicellulose, cellulose and lignin content found in rattan waste chemical composition is seen to help in binderless board fabrication. The micrographs revealed that the rattan has fine structural construction that helps in producing good qualities of binderless boards with particular manufacturing parameters.
WO3 particles were synthesized using sol-gel method. The WO3 particles was prepared using 0.4 M of sodium tungstate dehydrate for 21 h at 90 °C. The photocatalytic activity of WO3 particles in removal of RhB dye followed first order kinetics in both visible light and UV light irradiation. The investigation showed that WO3 particles degraded RhB dye more effectively under UV irradiation (43.2 %) than visible irradiation (2.6 %) in 75 min. The poor photodegradation efficiency was attributed to the narrow excitation band of visible light source. Besides, the scavenger tests indicated that the holes and hydroxyl radicals were the dominant reactive species in photocatalytic degradation of RhB dye. Based on these findings, the photodegradation mechanism of RhB dye by WO3 particles is proposed.
Angiogenicity is one of the essential components to enable tissue function. It is important to develop a construct that would help in catering oxygen and nutrient to the engineered tissue area. Thus, this study aims to investigate the attachment, spreading and growth of stem cells from human exfoliated deciduous teeth (SHED) on human AM (HAM) with or without vascular endothelial growth factor (VEGF) using scanning electron microscope (SEM), and indirectly see the potential of the HAM as a scaffold to promote angiogenic micro-environment. Since day 1, there were continuous changes of the cell morphology until day 28, SHED treated with VEGF seemed to change its shape from fibroblast-like into a round-shape cell, similar structure as an endotheliallike cell. The structures of filopodia-like were also observed on the treated SHED. SHED without VEGF treatment showed only normal morphological growth on HAM. VEGF is a protein produced to stimulate angiogenesis, and is believed to contribute to the morphological changes of SHED seeded on HAM. This indicates that HAM could be used as a scaffold to allow SHED differentiation into endothelial-like cells with the induction of VEGF.
Carbon fiber reinforced epoxy (CFRE) is commonly been used in automotive and aviation industries. However, CFRE composite exhibits the problem of adherence between fiber and matrix. The interface between carbon fiber (CF) and epoxy becomes a weak zone and leads to the debonding defect of fiber and low mechanical properties of composites. The main focus of this study is to fabricate CFRE using carbon nanotubes (CNTs), as the hybrid reinforcement with CF. Ultrasonic method is used to disperse CNTs in distilled water for 20 minutes, followed by deposition of CNTs on CF using electrophoretic deposition (EPD) technique. Hand lay-up assisted vacuum bagging is employed to fabricate CNTs/CF/Epoxy composite. From morphologies, surface topography and peel off testing, it can be confirmed that 30 minutes deposition allowed more CNTs to deposit on CF. The flexural properties shows that 30 minutes deposition inherited high flexural strength, 67.4 MPa and modulus, 8490 MPa.
Coracoid process (CP) bone quality and quantity are two important variables in many successful shoulder surgeries. The goal of this study was to determine the Bone Mineral Density (BMD) and morphometry of CP in Malaysian population using a non-invasive imaging data. Sixty-six (66) shoulders’ computed tomographic (CT) examinations of 132 potential sites were selected. BMD and morphometry of CP was evaluated using e-film. The present study found that there are significant (P
Mangosteen is a native fruit from Southeast Asia. It is rich in phenolic compounds like xanthones, anthocyanins and phenolic acids and also a good source of fibre and minerals. The present study aim to investigate the effects of mangosteen aril supplementation on the histopathological changes of liver and kidney in rats fed with high fat diet. Forty male Sprague Dawley rats were divided into five groups (n=8), which consisted of normal control group (NC), obese control group (OC), obese supplemented with 200 mg/kg mangosteen group (M200), obese supplemented with 400 mg/kg mangosteen group (M400) and obese supplemented with 600 mg/kg mangosteen group (M600). At the end of seven weeks, obese groups supplemented with mangosteen aril were force feed to correspond mangosteen dosage while the control groups were force feed with distilled water as placebo. At the end of seven weeks of supplementation period, all rats were sacrificed and liver and kidney were collected. All data were analyzed using one way ANOVA and the differences between groups were considered significant at p < 0.05. Results showed that supplementation of mangosteen aril in obese rats able to ameliorate the abnormalities in their liver and kidney tissue caused by high fat diet.
Incineration and disposal of carbon fiber waste from the aircraft industry lead to serious energy consumption and environmental pollution. The use of this waste as reinforcement is a wise approach to appreciate the high performance of the carbon fiber. This study is part of our effort to develop new green rubber foam from recycled carbon fiber prepreg (rCFP) reinforced natural rubber via internal mixer. It is focusing on the effect of different rCFP loading at 1, 3, 5, and 7 parts per hundred rubbers (phr) as reinforcement. The samples were prepared by melt compounding using an internal mixer and expanded via two step heat transfer foaming process. The physical properties of the green rubber foam were characterized and the results were observed to systematically correlate with the impact properties of the foam. The absorbed energy of the foam increases up to 0.3 joules with increasing relative foam density of 0.81 which is associated with the formation of smaller foam cells ~0.68mm and more spherical shape pores.
Biofilm complicates osteomyelitis as there is antibiotic resistance and toxicity involved. In order to overcome the challenges of current treatment, gentamicin, the current antibiotic of choice for osteomyelitis, is fused with Nigella sativa oil to form an emulsion. Its efficacy as anti-biofilm agent is assessed using confocal laser scanning microscope (CLSM) against different strains of biofilm-producing Staphylococcus aureus. These strains of S.aureus were first allowed to express biofilm before being exposed for 24 hours to the emulsion with (0.1% (w/v) gentamicin; 40.2% (v/v) N.sativa. Later, the emulsion was removed and the biofilm was stained with fluorescence staining. The slides were viewed under CLSM at 100 times resolution. 3D images of biofilm were reconstructed, using Image J software, to measure the thickness of biofilm and viability of bacteria cells. Results revealed that the emulsion significantly reduced biofilm thickness compared to gentamicin and N.sativa alone in all strains of S.aureus (Tukey’s test p < 0.05). The emulsion was also able to produce more than 80% and 15% surface percentage (%) of non-viable (dead) bacteria in the sensitive and resistant strain, respectively, at a significant level when compared to gentamicin and N.sativa (Tukey’s test p < 0.05). As a conclusion, this new fusion of gentamicin-N.sativa may be effective towards the biofilm of S.aureus, and can be developed further as a new promising anti-biofilm agent in osteomyelitis.
Pollen distribution from the pollen loads of stingless bee foragers in KampungTempinis, Besut, Terengganu was observed and recorded using optical microscope. Heterotrigona itama, one of the most common IndoMalayan stingless bee species domesticated and widely distributed throughout Malaysia was selected for this observation.The objective of this study was to have an annual bee calendar for H. itama in Besut. Pollen collection was carried out twice a month from January to June 2015. Results showed, during the six months period of observation H. itama foraged 31 different flowering plants. Different months of the year showed different floral preference by the stingless bee. The most dominant flower visited by the stingless bee in January and February is Stevia rebaudiana while March to June is Antigonon leptopus (Honolulu creeper). This observation could be useful for conservation purposes and also in planning a good beescape in Malaysia meliponiculture industry.
Current study report the growth of Zinc Oxide (ZnO) nanorods (NRs) by a facile and low temperature method on Zinc (Zn) foil in deionized (DI) water. These ZnO NRs have a typical length of 500-700 nm and average diameter of 50-70 nm. By using different volume of DI water, the morphology of ZnO nanostructures are tunable from rod-like to flower-like structures. Under the presence of Zn nitrate precursor, mixture of rod/wall-like structures are formed. Both of ZnO NRs and combined nanorods/nanowalls render higher diffraction for the (002) peak reveals, which implies preferred orientation growth along c-axis take place. However, photoluminescence (PL) study indicates that ZnO NRs have strong emission located at ~380 nm if compared to that of combined ZnO nanorods/nanowalls. This shows that ZnO NRs have higher-densities of defects.
Glass-ceramics are a group of materials that takes advantage of the various glass-forming methods before they are subsequently heat-treated in a controlled manner to effect nucleation and crystallization to produce crystalline materials. The production of glassceramic materials is to overcome the low mechanical strength in pure glassy materials. In this work, a study on the crystallisation of a soda-lime-silica glass was undertaken to ascertain how the processing parameters affect the crystallization of such glasses, viz. either via a single or two-step heat-treatment procedure, as well as the effect of soaking duration at the heat-treatment temperature. A soda-lime-silica glass system was chosen because the raw materials for producing such glasses are readily available and can be considered to be the cheapest. The glass produced was examined by thermal analysis to determine the nucleation and crystallization temperatures before they were heat-treated using a single-step and a two-stage heat-treatment procedures. The resultant glassceramics produced were characterized using x-ray diffraction as well as by scanning electron microscopy. The results thus obtained showed that a two-stage heat-treatment procedure is more successful in producing a well-crystallized glass-ceramic product.
Sol-gel barium titanate (BaTiO3) and erbium doped barium titanate (Er-BaTiO3) were deposited on SiO2/Si substrates. The phase and crystallinity of the thin films were identified using x-ray diffractometer (XRD). The effect of Er dopant into BaTiO3 thin film on its grain size and surface roughness was studied using atomic force microscope (AFM) in tapping mode. XRD patterns revealed that the films were crystallized with perovskite structure. At the same time, it was shown that introducing Er dopant into BaTiO3 thin film caused the dominant peak to shift towards higher angle. AFM micrographs indicated that the films had well distributed grains, dense and crack-free surface. In general, substitution of Er dopant into Ba-site reduced the grain sizes and roughness parameter of the BaTiO3 which was attributed to the smaller ionic radius of Er.
Porous ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. In this study, porous hydroxyapatite (HA) was produced via polymer replication method. Polyurethane (PU) sponge was selected as the template and synthetic binder, polyvinyl alcohol (PVA) was used in this study. Fixed formulation of HA powder, distilled water and PVA (40:60:3) were prepared and stirred at a constant 4 hours time. PU sponges with 30 ppi and 60 ppi size were cut and impregnated in slurry using vacuum and roller infiltration methods. The microstructures were observed by using field emission scanning electron microscope (FESEM). The results obtained indicate that vacuum infiltration method and 60 ppi template pore size exhibited the highest compressive strength with moderate average strut thickness and lowest average pore size compared to samples produced by roller infiltration method at different template pore size.
The effect of alginate concentration on the mechanical properties of hydroxyapatite (HAp) scaffold was investigated in this study. Sodium alginate solution with concentration 1%, 3% and 5% was prepared through the neutral extraction of cultivated Sargassumpolycystum brown seaweed. HAp scaffold was prepared via polymer reticulate method and sintered at 1250 ̊C. HAp scaffolds were then immersed in sodium alginate solution at 1%, 3% and 5% concentration under vacuum. FTIR spectra show that the extracted sodium alginate has the same functional groups as in commercial sodium alginate. Compressive strength increased as the sodium alginate concentration increased. Morphology observation shows that the micro cracks on the struts were covered by alginate. The increase in the compressive strength is due to the coverage of the cracks on the struts by sodium alginate.