Displaying publications 81 - 100 of 301 in total

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  1. Linear low density polyethylene/poly (vinyl alcohol)/kenaf composites: effect of natural weathering on functional group, weight loss characteristics, tensile, morphological and thermal properties
    Pang AL, Azhar Abu Bakar, Hanafi Ismail
    Sains Malaysiana, 2018;47:571-580.
    The development of natural fiber polymer composites is increasing worldwide and in some applications, these composites
    are used at outdoor rendering them exposed to ultra-violet (UV) radiation. The paper investigates the degradation behavior
    of linear low density polyethylene/poly (vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites after exposure to different
    natural weathering durations. The composites with KNF loadings of 10, 20 and 40 parts per hundred resin (phr) were
    exposed to natural weathering for 3 months and 6 months, respectively. The weathered composites were characterized by
    Fourier transform infrared (FTIR) spectroscopy, universal testing machine, field emission scanning electron microscopy
    (FESEM) and differential scanning calorimetry (DSC). The FTIR analysis showed an obvious carbonyl peak in composites
    after weathering as an evidence of oxidation. The weight loss percentage of composites increased with respect to exposure
    duration due to higher absorption of UV irradiation. The tensile properties of weathered composites were lower than
    that of control composites and these properties also decreased with increasing exposure duration. FESEM micrographs
    illustrated that composites with longer exposure duration suffered more surface damaged. The crystallinity percentage
    was found to increase with increasing exposure duration.
    Matched MeSH terms: Dietary Fiber
  2. Fulltext Temperature-insensitive bend sensor using entirely centered Erbium doping in the fiber core
    Ahmad H, Zulkifli MZ, Muhammad FD, Samangun JM, Abdul-Rashid HA, Harun SW
    Sensors (Basel), 2013;13(7):9536-46.
    PMID: 23881146 DOI: 10.3390/s130709536
    A fiber based bend sensor using a uniquely designed Bend-Sensitive Erbium Doped Fiber (BSEDF) is proposed and demonstrated. The BSEDF has two core regions, namely an undoped outer region with a diameter of about 9.38 μm encompassing a doped, inner core region with a diameter of 4.00 μm. The doped core region has about 400 ppm of an Er2O3 dopant. Pumping the BSEDF with a conventional 980 nm laser diode gives an Amplified Spontaneous Emission (ASE) spectrum spanning from 1,510 nm to over 1,560 nm at the output power level of about -58 dBm. The ASE spectrum has a peak power of -52 dBm at a central wavelength of 1,533 nm when not spooled. Spooling the BSEDF with diameters of 10 cm to 2 cm yields decreasing peak powers from -57.0 dBm to -61.8 dBm, while the central wavelength remains unchanged. The output is highly stable over time, with a low temperature sensitivity of around ~0.005 dBm/°C, thus allowing for the development of a highly stable sensor system based in the change of the peak power alone.
    Matched MeSH terms: Dietary Fiber
  3. Characterization of Microcrystalline Cellulose Isolated from Conocarpus Fiber
    Fouad H, Kian LK, Jawaid M, Alotaibi MD, Alothman OY, Hashem M
    Polymers (Basel), 2020 Dec 07;12(12).
    PMID: 33297332 DOI: 10.3390/polym12122926
    Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.
    Matched MeSH terms: Dietary Fiber
  4. Functional properties and characterization of dietary fiber from Mangifera pajang Kort. fruit pulp
    Al-Sheraji SH, Ismail A, Manap MY, Mustafa S, Yusof RM, Hassan FA
    J Agric Food Chem, 2011 Apr 27;59(8):3980-5.
    PMID: 21388187 DOI: 10.1021/jf103956g
    A dried high fiber product from bambangan (Mangifera pajang Kort.) fruit pulp was prepared and evaluated for proximate composition, functional properties, and soluble and insoluble dietary fiber composition. Mangifera pajang fibrous (MPF) consisted of 4.7% moisture, 0.8% fat, 4% protein, and 30 mg total polyphenol per g of dry sample, and 9, 79 and 88% soluble, insoluble and total dietary fiber, respectively. Water holding capacity, oil holding capacity, swelling, and solubility were found to be 9 g/g dry sample, 4 g/g dry sample, 16 mL/g dry sample, and 11%, respectively. The glucose dialysis retardation index of MPF was approximately double that of cellulose fiber. Soluble dietary fiber contained mannose, arabinose, glucose, rhamnose, erythrose, galactose, xylose, and fucose at 1.51, 0.72, 0.39, 0.16, 0.14, 0.05, 0.04, and 0.01%, respectively, with 5.8% uronic acid, while insoluble dietary fiber was composed of arabinose (18.47%), glucose (4.46%), mannose (3.15%), rhamnose (1.65%), galactose (1.20%), xylose (0.99%), and fucose (0.26%) with 15.5% uronic acid and 33.1% klason lignin. These characteristics indicate that MPF is a rich source of dietary fiber and has physicochemical properties which make it suitable as an added ingredient in various food products and/or dietetic, low-calorie high-fiber foods to enhance their nutraceutical properties.
    Matched MeSH terms: Dietary Fiber/analysis; Dietary Fiber/pharmacology*
  5. Soluble inhibitors generated during hydrothermal pretreatment of oil palm mesocarp fiber suppressed the catalytic activity of Acremonium cellulase
    Zakaria MR, Hirata S, Fujimoto S, Ibrahim I, Hassan MA
    Bioresour Technol, 2016 Jan;200:541-7.
    PMID: 26524253 DOI: 10.1016/j.biortech.2015.10.075
    Oil palm mesocarp fiber was subjected to hydrothermal pretreatment under isothermal and non-isothermal conditions. The pretreated slurries were separated by filtration, pretreated liquids and solids were characterized. An enzymatic digestibility study was performed for both pretreated slurries and solids to understand the effect of soluble inhibitors generated during the pretreatment process. The highest glucose yield obtained from pretreated slurries was 70.1%, and gradually decreased with higher pretreatment severities. The highest glucose yield obtained in pretreated solids was 100%, after pretreatment at 210°C for 20min. In order to study the inhibitory effects of compounds generated during pretreatment with cellulase, technical grade solutions that mimic the pretreated liquid were prepared and their effect on Acremonium cellulase activity was monitored using Avicel. Xylo-oligomers and tannic acid were identified as powerful inhibitors of Acremonium cellulase, and the lowest hydrolysis rate of Avicel of 0.18g/g-glucose released/L/h was obtained from tannic acid.
    Matched MeSH terms: Dietary Fiber
  6. Fulltext Effect of mangosteen (Garcinia mangostana) on morphological changes in the liver and kidney of rats fed with high fat diet
    Noratirah Shazlin, M.A., Asmah, R., Nurul Shazini, R., Hawa, Z.E.J.
    Malaysian Journal of Microscopy, 2016;12(1):48-53.
    MyJurnal
    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.
    Matched MeSH terms: Dietary Fiber
  7. Fulltext Phytochemical Properties and Nutrigenomic Implications of Yacon as a Potential Source of Prebiotic: Current Evidence and Future Directions
    Cao Y, Ma ZF, Zhang H, Jin Y, Zhang Y, Hayford F
    Foods, 2018 Apr 12;7(4).
    PMID: 29649123 DOI: 10.3390/foods7040059
    The human gut is densely populated with diverse microbial communities that are essential to health. Prebiotics and fiber have been shown to possess the ability to modulate the gut microbiota. One of the plants being considered as a potential source of prebiotic is yacon. Yacon is an underutilized plant consumed as a traditional root-based fruit in South America. Yacon mainly contains fructooligosaccharides (FOS) and inulin. Therefore, it has bifidogenic benefits for gut health, because FOS are not easily broken down by digestive enzymes. Bioactive chemical compounds and extracts isolated from yacon have been studied for their various nutrigenomic properties, including as a prebiotic for intestinal health and their antimicrobial and antioxidant effects. This article reviewed scientific studies regarding the bioactive chemical compounds and nutrigenomic properties of extracts and isolated compounds from yacon. These findings may help in further research to investigate yacon-based nutritional products. Yacon can be considered a potential prebiotic source and a novel functional food. However, more detailed epidemiological, animal, and human clinical studies, particularly mechanism-based and phytopharmacological studies, are lacking for the development of evidence-based functional food products.
    Matched MeSH terms: Dietary Fiber
  8. Fulltext Synthesis and characterization of cis-5-norbornene-2, 3-dicarboxylic anhydride-chitosan
    Ku Marsilla Ku Ishak, Zulkifli Ahmad, Hazizan Md Akil
    Journal of Nuclear and Related Technologies, 2009;2009(1):111-120.
    MyJurnal
    Chitosan was chemically modified with bulky structure, cis-5-norbornene-2, 3-dicarboxylic anhydride and the characteristic of this modified chitosan was studied. The resulting material was analyzed by FTIR, TGA, DSC, XRD and SEM to study the effect of N-acylation to the polysaccharide structure. FTIR results show that the anhydride monomer was successfully bound to amine group of chitosan. Thermal analysis of the modified structure provides the chitosan fibers with thermal stability while XRD and SEM show the lost of crystallinity of modified chitosan. XRD of modified chitosan shows broader peak pattern and a considerable increase in a dimension while SEM of chitosan presented the single particle morphology while norbornene-chitosan shows aggromolarate behaviour due to the hydrophobic nature of norbornene pendant group which induced aggromolaration of the particles in modified structure.
    Matched MeSH terms: Dietary Fiber
  9. The Athlete and Gut Microbiome: Short-chain Fatty Acids as Potential Ergogenic Aids for Exercise and Training
    Bongiovanni T, Yin MOL, Heaney L
    Int J Sports Med, 2021 Dec;42(13):1143-1158.
    PMID: 34256388 DOI: 10.1055/a-1524-2095
    Short-chain fatty acids (SCFAs) are metabolites produced in the gut via microbial fermentation of dietary fibers referred to as microbiota-accessible carbohydrates (MACs). Acetate, propionate, and butyrate have been observed to regulate host dietary nutrient metabolism, energy balance, and local and systemic immune functions. In vitro and in vivo experiments have shown links between the presence of bacteria-derived SCFAs and host health through the blunting of inflammatory processes, as well as purported protection from the development of illness associated with respiratory infections. This bank of evidence suggests that SCFAs could be beneficial to enhance the athlete's immunity, as well as act to improve exercise recovery via anti-inflammatory activity and to provide additional energy substrates for exercise performance. However, the mechanistic basis and applied evidence for these relationships in humans have yet to be fully established. In this narrative review, we explore the existing knowledge of SCFA synthesis and the functional importance of the gut microbiome composition to induce SCFA production. Further, changes in gut microbiota associated with exercise and various dietary MACs are described. Finally, we provide suggestions for future research and practical applications, including how these metabolites could be manipulated through dietary fiber intake to optimize immunity and energy metabolism.
    Matched MeSH terms: Dietary Fiber
  10. Production of acetoin from hydrothermally pretreated oil mesocarp fiber using metabolically engineered Escherichia coli in a bioreactor system
    Mohd Yusoff MZ, Akita H, Hassan MA, Fujimoto S, Yoshida M, Nakashima N, et al.
    Bioresour Technol, 2017 Dec;245(Pt A):1040-1048.
    PMID: 28946206 DOI: 10.1016/j.biortech.2017.08.131
    Acetoin is used in the biochemical, chemical and pharmaceutical industries. Several effective methods for acetoin production from petroleum-based substrates have been developed, but they all have an environmental impact and do not meet sustainability criteria. Here we describe a simple and efficient method for acetoin production from oil palm mesocarp fiber hydrolysate using engineered Escherichia coli. An optimization of culture conditions for acetoin production was carried out using reagent-grade chemicals. The final concentration reached 29.9gL(-1) with a theoretical yield of 79%. The optimal pretreatment conditions for preparing hydrolysate with higher sugar yields were then determined. When acetoin was produced using hydrolysate fortified with yeast extract, the theoretical yield reached 97% with an acetoin concentration of 15.5gL(-1). The acetoin productivity was 10-fold higher than that obtained using reagent-grade sugars. This approach makes use of a compromise strategy for effective utilization of oil palm biomass towards industrial application.
    Matched MeSH terms: Dietary Fiber
  11. Thermoluminescence characteristics of Nd-doped SiO2 optical fibers irradiated with the (60)Co gamma rays
    Refaei A, Wagiran H, Saeed MA, Hosssain I
    Appl Radiat Isot, 2014 Dec;94:89-92.
    PMID: 25146569 DOI: 10.1016/j.apradiso.2014.07.012
    Thermoluminescence (TL) properties (radiation sensitivity, dose response, signal fading) of Nd-doped SiO2 optical fibers irradiated with 1.25MeV photons to 1-50Gy were studied. The peak of the glow curve is around 190°C regardless of the dose. The dose response is linear up to 50Gy. The radiation sensitivity is 219nCmg(-1)Gy(-1). The fiber can be a potential candidate for photon radiotherapy dosimetry due to its high radiation sensitivity, linear dose response in a wide range, slow fading, and high spatial resolution due to the small size of the fiber.
    Matched MeSH terms: Dietary Fiber
  12. Fulltext Nutritional composition of ready-to-eat cereals in the Malaysian market
    Suraiami, M., Mohd Fairulnizal, M.N., Norhayati, M.K., Zaiton, A., Norliza, A.H., Wan Syuriahti, W.Z., et al.
    Malays J Nutr, 2014;20(3):417-427.
    MyJurnal
    Introduction: This study aimed to determine the nutrient content of cornflakes and muesli, ready-to-eat cereal products available in the Malaysian market. Cornflakes and muesli were chosen due to their popularity as a breakfast meal especially in urban areas. Methods: A total of six brands each for cornflakes and muesli were purchased from supermarkets in the Klang Valley using stratified random sampling. All samples were analysed using AOAC official methods of analysis. The validity of the test data was monitored with the application of internal quality controls in line with the requirements of ISO 17025. Results: Proximate analysis revealed significantly higher mean levels of carbohydrate (86.94 ± 0.59 mg/lOOg), minerals such as iron (8.48±1.72 mg/lOOg) and sodium (674.83±102.99 g/lOOg), B3 as niacinamide (25.87 ± 6.14 g/lOOg) and sucrose (5.10 ± 0.90 mg/lOOg) in cornflakes than in muesli. However, muesli contained significantly more mean moisture (10.23 ± 0.72 mg/lOOg), protein (10.07 ± 0.79 mg/lOOg), total dietary fibre (12.49 ± 1.44 mg/lOOg), magnesium (113.22 ± 7.93 mg/lOOg), zinc (1.65 ± 0.16 mg/lOOg), copper (0.25 ± 0.02 mg/lOOg), total sugar (18.75 ± 2.05 mg/lOOg), glucose (7.70±1.77 mg/lOOg) and fructose (8.68±1.76 mg/lOOg) than cornflakes. Most of the fatty acids analysed were not detected or of low value in both the cereal products. Conclusion: The nutrient analysis of cornflakes and muesli suggests that both ready-to-eat cereals are nutritionally good choice as breakfast for consumers as it provides carbohydrate, minerals, fibre and vitamins. The data provides additional information to the Malaysian Food Composition Database.
    Matched MeSH terms: Dietary Fiber
  13. Dietary carbohydrate, fiber and sugar and risk of breast cancer according to menopausal status in Malaysia
    Sulaiman S, Shahril MR, Wafa SW, Shaharudin SH, Hussin SN
    Asian Pac J Cancer Prev, 2014;15(14):5959-64.
    PMID: 25081729
    BACKGROUND: Dietary carbohydrate, fiber and sugar intake has been shown to play a role in the etiology of breast cancer, but the findings have been inconsistent and limited to developed countries with higher cancer incidence.

    OBJECTIVE: To examine the association of premenopausal and postmenopausal breast cancer risk with dietary carbohydrate, fiber and sugar intake.

    MATERIALS AND METHODS: This population based case-control study was conducted in Malaysia with 382 breast cancer patients and 382 controls. Food intake pattern was assessed via an interviewer-administered food frequency questionnaire. Logistic regression was used to compute odds ratios (OR) with 95% confidence intervals (CI) and a broad range of potential confounders were included in analysis.

    RESULTS: A significant two fold increased risk of breast cancer among premenopausal (OR Q4 to Q1=1.93, 95%CI: 1.53-2.61, p-trend=0.001) and postmenopausal (OR Q4 to Q1=1.87, 95%CI: 1.03-2.61, p-trend=0.045) women was observed in the highest quartile of sugar. A higher intake of dietary fiber was associated with a significantly lower breast cancer risk among both premenopausal (OR Q4 to Q1=0.31, 95%CI: 0.12-0.79, p-trend=0.009) and postmenopausal (OR Q4 to Q1=0.23, 95%CI: 0.07-0.76, p-trend=0.031) women.

    CONCLUSIONS: Sugar and dietary fiber intake were independently related to pre- and postmenopausal breast cancer risk. However, no association was observed for dietary carbohydrate intake.

    Matched MeSH terms: Dietary Fiber/adverse effects*
  14. Effect of rice husk surface modification by LENR the on mechanical properties of NR/HDPE reinforced rice husk composite
    Rahmadini Syafri, Ishak Ahmad, Ibrahim Abdullah
    Sains Malaysiana, 2011;40:1123-1127.
    Surface modification of rice husk (RH) with alkali pre-treatment (NaOH solution 5% w/v) was carried out at the initial state to investigate the effect of surface treatment of fibre on the surface interaction between fibre and rubber. Further modification of RH surfaces after alkali treatment was using Liquid Epoxidized Natural Rubber (LENR) coating at three concentrations, 5%, 10%, and 20% wt LENR solution in toluene. Interfacial morphology and chemical reactions between RH fibre and rubber were analyzed by FTIR and Scanning Electron Microscope (SEM). It was found that 10% wt LENR solution gave the optimum interaction between fibre and rubber. Matrix and composite blends derived from 60% natural rubber (NR), 40% high density polyethylene (HDPE) reinforced with RH fibre were prepared using an internal mixer (Brabender Plasticoder). Result showed that pre-treatment of RH treated with 5% NaOH followed by treatment with 10% LENR solution given the maximum interaction between fibre and matrix that gave rise to better mechanical properties of the composites.
    Matched MeSH terms: Dietary Fiber
  15. Effects of silane surface treatment of cellulose nanocrystals on the tensile properties of cellulose-polyvinyl chloride nanocomposite
    Rasha M. Sheltami, Hanieh Kargarzadeh, Ibrahim Abdullah
    Sains Malaysiana, 2015;44:801-810.
    Cellulose nanocrystals (CNC) from mengkuang leaves (Pandanus tectorius) were investigated as potential reinforcement
    in poly(vinyl chloride) (PVC) matrix. The surface of CNC was modified with silane coupling agent to improve fillermatrix
    adhesion. Solution casting method was used to prepare PVC nanocomposites with various amounts of modified
    (SCNC) and unmodified (CNC) nanocrystals. Both SCNC and CNC were examined by Fourier transform infrared (FTIR)
    spectroscopy and X-ray diffraction (XRD) which showed that surface chemical modification has occurred. An increase
    in tensile strength was observed with the addition of SCNC compared to the CNC. However, the elongation at break of the
    nanocomposites was found to decrease with the increase of both fillers loading. An increasing trend was observed in the
    tensile modulus with the addition of CNC to the PVC matrix, but decreasing with the addition of SCNC. The morphology
    of a fractured surface of nanocomposites showed silane modification reduced the number of voids in the structure of
    PVC. The observation indicated the adhesion between the fiber and the matrix had improved upon surface modification
    of the nanocrystals with silane.
    Matched MeSH terms: Dietary Fiber
  16. Fulltext Physical Properties of Thermoplastic Starch Derived from Natural Resources and Its Blends: A Review
    Diyana ZN, Jumaidin R, Selamat MZ, Ghazali I, Julmohammad N, Huda N, et al.
    Polymers (Basel), 2021 Apr 26;13(9).
    PMID: 33925897 DOI: 10.3390/polym13091396
    Thermoplastic starch composites have attracted significant attention due to the rise of environmental pollutions induced by the use of synthetic petroleum-based polymer materials. The degradation of traditional plastics requires an unusually long time, which may lead to high cost and secondary pollution. To solve these difficulties, more petroleum-based plastics should be substituted with sustainable bio-based plastics. Renewable and natural materials that are abundant in nature are potential candidates for a wide range of polymers, which can be used to replace their synthetic counterparts. This paper focuses on some aspects of biopolymers and their classes, providing a description of starch as a main component of biopolymers, composites, and potential applications of thermoplastics starch-based in packaging application. Currently, biopolymer composites blended with other components have exhibited several enhanced qualities. The same behavior is also observed when natural fibre is incorporated with biopolymers. However, it should be noted that the degree of compatibility between starch and other biopolymers extensively varies depending on the specific biopolymer. Although their efficacy is yet to reach the level of their fossil fuel counterparts, biopolymers have made a distinguishing mark, which will continue to inspire the creation of novel substances for many years to come.
    Matched MeSH terms: Dietary Fiber
  17. Fulltext Tapered Polymer Fiber Sensors for Reinforced Concrete Beam Vibration Detection
    Luo D, Ibrahim Z, Ma J, Ismail Z, Iseley DT
    Sensors (Basel), 2016 Dec 16;16(12).
    PMID: 27999245 DOI: 10.3390/s16122149
    In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well with Kistler accelerometers. The experimental results found that both the accelerometer and TPFS detected the natural frequency function of a vibrated RC beam well. The mode shapes of the RC beam were also found by using the TPFSs. The proposed vibration detection method provides a cost-comparable solution for a structural health monitoring (SHM) system in civil engineering.
    Matched MeSH terms: Dietary Fiber
  18. Fulltext A Near Zero Refractive Index Metamaterial for Electromagnetic Invisibility Cloaking Operation
    Islam SS, Faruque MRI, Islam MT
    Materials (Basel), 2015 Jul 29;8(8):4790-4804.
    PMID: 28793472 DOI: 10.3390/ma8084790
    The paper reveals the design of a unit cell of a metamaterial that shows more than 2 GHz wideband near zero refractive index (NZRI) property in the C-band region of microwave spectra. The two arms of the unit cell were splitted in such a way that forms a near-pi-shape structure on epoxy resin fiber (FR-4) substrate material. The reflection and transmission characteristics of the unit cell were achieved by utilizing finite integration technique based simulation software. Measured results were presented, which complied well with simulated results. The unit cell was then applied to build a single layer rectangular-shaped cloak that operates in the C-band region where a metal cylinder was perfectly hidden electromagnetically by reducing the scattering width below zero. Moreover, the unit cell shows NZRI property there. The experimental result for the cloak operation was presented in terms of S-parameters as well. In addition, the same metamaterial shell was also adopted for designing an eye-shaped and triangular-shaped cloak structure to cloak the same object, and cloaking operation is achieved in the C-band, as well with slightly better cloaking performance. The novel design, NZRI property, and single layer C-band cloaking operation has made the design a promising one in the electromagnetic paradigm.
    Matched MeSH terms: Dietary Fiber
  19. Fulltext Novel Activated Carbon Nanofibers Composited with Cost-Effective Graphene-Based Materials for Enhanced Adsorption Performance toward Methane
    Che Othman FE, Yusof N, Yub Harun N, Bilad MR, Jaafar J, Aziz F, et al.
    Polymers (Basel), 2020 Sep 10;12(9).
    PMID: 32927881 DOI: 10.3390/polym12092064
    Various types of activated carbon nanofibers' (ACNFs) composites have been extensively studied and reported recently due to their extraordinary properties and applications. This study reports the fabrication and assessments of ACNFs incorporated with graphene-based materials, known as gACNFs, via simple electrospinning and subsequent physical activation process. TGA analysis proved graphene-derived rice husk ashes (GRHA)/ACNFs possess twice the carbon yield and thermally stable properties compared to other samples. Raman spectra, XRD, and FTIR analyses explained the chemical structures in all resultant gACNFs samples. The SEM and EDX results revealed the average fiber diameters of the gACNFs, ranging from 250 to 400 nm, and the successful incorporation of both GRHA and reduced graphene oxide (rGO) into the ACNFs' structures. The results revealed that ACNFs incorporated with GRHA possesses the highest specific surface area (SSA), of 384 m2/g, with high micropore volume, of 0.1580 cm3/g, which is up to 88% of the total pore volume. The GRHA/ACNF was found to be a better adsorbent for CH4 compared to pristine ACNFs and reduced graphene oxide (rGO/ACNF) as it showed sorption up to 66.40 mmol/g at 25 °C and 12 bar. The sorption capacity of the GRHA/ACNF was impressively higher than earlier reported studies on ACNFs and ACNF composites. Interestingly, the CH4 adsorption of all ACNF samples obeyed the pseudo-second-order kinetic model at low pressure (4 bar), indicating the chemisorption behaviors. However, it obeyed the pseudo-first order at higher pressures (8 and 12 bar), indicating the physisorption behaviors. These results correspond to the textural properties that describe that the high adsorption capacity of CH4 at high pressure is mainly dependent upon the specific surface area (SSA), pore size distribution, and the suitable range of pore size.
    Matched MeSH terms: Dietary Fiber
  20. Fulltext Effect of Defatted Dabai Pulp Extract in Urine Metabolomics of Hypercholesterolemic Rats
    Kadir NAAA, Azlan A, Abas F, Ismail IS
    Nutrients, 2020 Nov 14;12(11).
    PMID: 33202660 DOI: 10.3390/nu12113511
    A source of functional food can be utilized from a source that might otherwise be considered waste. This study investigates the hypocholesterolemic effect of defatted dabai pulp (DDP) from supercritical carbon dioxide extraction and the metabolic alterations associated with the therapeutic effects of DDP using 1H NMR urinary metabolomic analysis. Male-specific pathogen-free Sprague-Dawley rats were fed with a high cholesterol diet for 30 days to induce hypercholesterolemia. Later, the rats were administered with a 2% DDP treatment diet for another 30 days. Supplementation with the 2% DDP treatment diet significantly reduced the level of total cholesterol (TC), triglyceride, low-density lipoprotein (LDL), and inflammatory markers (C-reactive protein (CRP), interleukin 6 (IL6) and tumour necrosis factor-α (α-TNF)) and significantly increased the level of antioxidant profile (total antioxidant status (TAS), superoxide dismutase (SOD), glutathione peroxide (GPX), and catalase (CAT)) compared with the positive control group (PG) group (p < 0.05). The presence of high dietary fibre (28.73 ± 1.82 g/100 g) and phenolic compounds (syringic acid, 4-hydroxybenzoic acid and gallic acid) are potential factors contributing to the beneficial effect. Assessment of 1H NMR urinary metabolomics revealed that supplementation of 2% of DDP can partially recover the dysfunction in the metabolism induced by hypercholesterolemia via choline metabolism. 1H-NMR-based metabolomic analysis of urine from hypercholesterolemic rats in this study uncovered the therapeutic effect of DDP to combat hypercholesterolemia.
    Matched MeSH terms: Dietary Fiber/administration & dosage
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