Browse publications by year: 2021

  1. Mohd Hanafiah K, Ng C, Wan AM
    Viruses, 2021 Jun 03;13(6).
    PMID: 34204909 DOI: 10.3390/v13061058
    In an age of globalisation and hyperconnectivity, the COVID-19 pandemic has caused unprecedented and sustained impact worldwide. This article discusses issues related to (science) communication at different phases of the COVID-19 epidemic timeline. We consider the role of communication for prevention from the ecological perspective, taking into consideration that many emerging pathogens, including COVID-19, likely arise in part due to anthropogenic changes to natural environments. Communication forms part of the early response setting the scene for public buy-in of public health interventions at the start of an outbreak, as well as to maintain precautions over time. Finally, communication is a key element in increasing acceptance for new tools that require mass uptake to be effective, as seen with roll-out challenges for the COVID-19 vaccines, which faced heightened concerns of efficacy and safety while mired with rampant misinformation. Ultimately, strategies for prevention of viral epidemics such as COVID-19 must include communication strategies at the forefront to reduce the risk of the emergence of new diseases and enhance efforts to control their spread and burden. Despite key themes emerging, what constitutes effective communication strategies for different people and contexts needs to be investigated further.
    MeSH terms: Communication*; Disease Outbreaks/prevention & control*; Humans; Public Health/education; Public Health/methods*; Social Media
  2. Chukwuma OB, Rafatullah M, Tajarudin HA, Ismail N
    Int J Environ Res Public Health, 2021 Jun 03;18(11).
    PMID: 34204975 DOI: 10.3390/ijerph18116001
    Discovering novel bacterial strains might be the link to unlocking the value in lignocellulosic bio-refinery as we strive to find alternative and cleaner sources of energy. Bacteria display promise in lignocellulolytic breakdown because of their innate ability to adapt and grow under both optimum and extreme conditions. This versatility of bacterial strains is being harnessed, with qualities like adapting to various temperature, aero tolerance, and nutrient availability driving the use of bacteria in bio-refinery studies. Their flexible nature holds exciting promise in biotechnology, but despite recent pointers to a greener edge in the pretreatment of lignocellulose biomass and lignocellulose-driven bioconversion to value-added products, the cost of adoption and subsequent scaling up industrially still pose challenges to their adoption. However, recent studies have seen the use of co-culture, co-digestion, and bioengineering to overcome identified setbacks to using bacterial strains to breakdown lignocellulose into its major polymers and then to useful products ranging from ethanol, enzymes, biodiesel, bioflocculants, and many others. In this review, research on bacteria involved in lignocellulose breakdown is reviewed and summarized to provide background for further research. Future perspectives are explored as bacteria have a role to play in the adoption of greener energy alternatives using lignocellulosic biomass.
    MeSH terms: Bacteria; Lignin*; Biomass; Biofuels*
  3. Kamaruzzaman WMIWM, Fekeri MFM, Nasir NAM, Hamidi NASM, Baharom MZ, Adnan A, et al.
    Molecules, 2021 Jun 03;26(11).
    PMID: 34205014 DOI: 10.3390/molecules26113379
    With the trend for green technology, the study focused on utilizing a forgotten herb to produce an eco-friendly coating. Andrographis paniculata or the kalmegh leaves extract (KLE) has been investigated for its abilities in retarding the corrosion process due to its excellent anti-oxidative and antimicrobial properties. Here, KLE was employed as a novel additive in coatings and formulations were made by varying its wt%: 0, 3, 6, 9, and 12. These were applied to stainless steel 316L immersed in seawater for up to 50 days. The samples were characterized and analyzed to measure effectiveness of inhibition of corrosion and microbial growth. The best concentration was revealed to be 6 wt% KLE; it exhibited the highest performance in improving the ionic resistance of the coating and reducing the growth of bacteria.
    MeSH terms: Anti-Infective Agents/pharmacology; Anti-Infective Agents/chemistry; Antioxidants/pharmacology; Antioxidants/chemistry; Corrosion; Materials Testing; Plant Extracts/chemistry*; Seawater/microbiology; Seawater/chemistry*; Stainless Steel/pharmacology*; Stainless Steel/chemistry; Plant Leaves/chemistry; Coated Materials, Biocompatible/pharmacology*; Coated Materials, Biocompatible/chemistry; Andrographis/chemistry*; Green Chemistry Technology
  4. Al-Sodani KAA, Adewumi AA, Mohd Ariffin MA, Maslehuddin M, Ismail M, Salami HO, et al.
    Materials (Basel), 2021 Jun 03;14(11).
    PMID: 34205101 DOI: 10.3390/ma14113049
    This paper presents the outcome of work conducted to develop models for the prediction of compressive strength (CS) of alkali-activated limestone powder and natural pozzolan mortar (AALNM) using hybrid genetic algorithm (GA) and support vector regression (SVR) algorithm, for the first time. The developed hybrid GA-SVR-CS1, GA-SVR-CS3, and GA-SVR-CS14 models are capable of estimating the one-day, three-day, and 14-day compressive strength, respectively, of AALNM up to 96.64%, 90.84%, and 93.40% degree of accuracy as measured on the basis of correlation coefficient between the measured and estimated values for a set of data that is excluded from training and testing phase of the model development. The developed hybrid GA-SVR-CS28E model estimates the 28-days compressive strength of AALNM using the 14-days strength, it performs better than hybrid GA-SVR-CS28C model, hybrid GA-SVR-CS28B model, hybrid GA-SVR-CS28A model, and hybrid GA-SVR-CS28D model that respectively estimates the 28-day compressive strength using three-day strength, one day-strength, all the descriptors and seven day-strength with performance improvement of 103.51%, 124.47%, 149.94%, and 262.08% on the basis of root mean square error. The outcome of this work will promote the use of environment-friendly concrete with excellent strength and provide effective as well as efficient ways of modeling the compressive strength of concrete.
  5. Borzehandani MY, Abdulmalek E, Abdul Rahman MB, Latif MAM
    Polymers (Basel), 2021 Jun 03;13(11).
    PMID: 34205141 DOI: 10.3390/polym13111861
    Covalent organic frameworks (COFs) have a distinguished surface as they are mostly made by boron, carbon, nitrogen and oxygen. Many applications of COFs rely on polarity, size, charge, stability and hydrophobicity/hydrophilicity of their surface. In this study, two frequently used COFs sheets, COF-1 and covalent triazine-based frameworks (CTF-1), are studied. In addition, a theoretical porous graphene (TPG) was included for comparison purposes. The three solid sheets were investigated for aromaticity and stability using quantum mechanics calculations and their ability for water and ethanol adsorption using molecular dynamics simulations. COF-1 demonstrated the poorest aromatic character due to the highest energy delocalization interaction between B-O bonding orbital of sigma type and unfilled valence-shell nonbonding of boron. CTF-1 was identified as the least kinetically stable and the most chemically reactive. Both COF-1 and CTF-1 showed good surface properties for selective adsorption of water via hydrogen bonding and electrostatic interactions. Among the three sheets, TPG's surface was mostly affected by aromatic currents and localized π electrons on the phenyl rings which in turn made it the best platform for selective adsorption of ethanol via van der Waals interactions. These results can serve as guidelines for future studies on solvent adsorption for COFs materials.
  6. Zakaria NN, Gomez-Fuentes C, Abdul Khalil K, Convey P, Roslee AFA, Zulkharnain A, et al.
    Microorganisms, 2021 Jun 03;9(6).
    PMID: 34205164 DOI: 10.3390/microorganisms9061213
    Hydrocarbon pollution is widespread around the globe and, even in the remoteness of Antarctica, the impacts of hydrocarbons from anthropogenic sources are still apparent. Antarctica's chronically cold temperatures and other extreme environmental conditions reduce the rates of biological processes, including the biodegradation of pollutants. However, the native Antarctic microbial diversity provides a reservoir of cold-adapted microorganisms, some of which have the potential for biodegradation. This study evaluated the diesel hydrocarbon-degrading ability of a psychrotolerant marine bacterial consortium obtained from the coast of the north-west Antarctic Peninsula. The consortium's growth conditions were optimised using one-factor-at-a-time (OFAT) and statistical response surface methodology (RSM), which identified optimal growth conditions of pH 8.0, 10 °C, 25 ppt NaCl and 1.5 g/L NH4NO3. The predicted model was highly significant and confirmed that the parameters' salinity, temperature, nitrogen concentration and initial diesel concentration significantly influenced diesel biodegradation. Using the optimised values generated by RSM, a mass reduction of 12.23 mg/mL from the initial 30.518 mg/mL (4% (w/v)) concentration of diesel was achieved within a 6 d incubation period. This study provides further evidence for the presence of native hydrocarbon-degrading bacteria in non-contaminated Antarctic seawater.
  7. Ismail NF, Mohd Radzuan NA, Sulong AB, Muhamad N, Che Haron CH
    Polymers (Basel), 2021 Jun 19;13(12).
    PMID: 34205236 DOI: 10.3390/polym13122005
    The use of kenaf fiber as a reinforcement material for polymer composites is gaining popularity, especially in the production of automotive components. The main objective of this current work is to relate the effect of alkali treatment on the single fiber itself and the composite material simultaneously. The effect of temperature condition during mechanical testing is also investigated. Composite materials with discontinuous natural kenaf fibers and epoxy resin were fabricated using a compression moulding process. The epoxy composites were reinforced with 50 wt% untreated and treated kenaf fibers. The kenaf fiber was treated with NaOH solution (6% by weight) for 24 h at room temperature. Kenaf fiber treated with NaOH treatment had a clean surface and no impurities. For the first time we can see that alkali treatment had a damaging effect on the mechanical properties of kenaf fibers itself and the treated kenaf/epoxy composites. The composite reinforced with untreated kenaf fiber and treated kenaf fiber showed increased tensile strength (72.85% and 12.97%, respectively) compared to the neat epoxy. Reinforcement of the composite with treated kenaf fiber decreased the tensile strength due to the fiber pull out and the formation of voids which weakens the adhesion between the fibers and matrix. The temperature conditions also play an important role in composites with a significant impact on the deterioration of composite materials. Treated kenaf fiber has thermal stability and is not sensitive to temperature and as a result reinforcement with treated kenaf gives a lower loss value of 76%.
  8. Rahmati S, Doherty W, Amani Babadi A, Akmal Che Mansor MS, Julkapli NM, Hessel V, et al.
    Micromachines (Basel), 2021 Jun 19;12(6).
    PMID: 34205255 DOI: 10.3390/mi12060719
    The environmental crisis, due to the rapid growth of the world population and globalisation, is a serious concern of this century. Nanoscience and nanotechnology play an important role in addressing a wide range of environmental issues with innovative and successful solutions. Identification and control of emerging chemical contaminants have received substantial interest in recent years. As a result, there is a need for reliable and rapid analytical tools capable of performing sample analysis with high sensitivity, broad selectivity, desired stability, and minimal sample handling for the detection, degradation, and removal of hazardous contaminants. In this review, various gold-carbon nanocomposites-based sensors/biosensors that have been developed thus far are explored. The electrochemical platforms, synthesis, diverse applications, and effective monitoring of environmental pollutants are investigated comparatively.
  9. Kakihana Y, Hashim NA, Mizuno T, Anno M, Higa M
    Membranes (Basel), 2021 Jun 19;11(6).
    PMID: 34205395 DOI: 10.3390/membranes11060452
    Membrane resistance and permselectivity for counter-ions have important roles in determining the performance of cation-exchange membranes (CEMs). In this study, PVA-based polyanions-poly(vinyl alcohol-b-sodium styrene sulfonate)-were synthesized, changing the molar percentages CCEG of the cation-exchange groups with respect to the vinyl alcohol groups. From the block copolymer, poly(vinyl alcohol) (PVA)-based CEMs, hereafter called "B-CEMs", were prepared by crosslinking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations CGA. The ionic transport properties of the B-CEMs were compared with those previously reported for the CEMs prepared using a random copolymer-poly(vinyl alcohol-co-2-acrylamido-2-methylpropane sulfonic acid)-hereafter called "R-CEMs". The B-CEMs had lower water content than the R-CEMs at equal molar percentages of the cation-exchange groups. The charge density of the B-CEMs increased as CCEG increased, and reached a maximum value, which increased with increasing CGA. A maximum charge density of 1.47 mol/dm3 was obtained for a B-CEM with CCEG = 2.9 mol% and CGA = 0.10 vol.%, indicating that the B-CEM had almost two-thirds of the permselectivity of a commercial CEM (CMX: ASTOM Corp. Japan). The dynamic transport number and membrane resistance of a B-CEM with CCEG = 8.3 mol% and CGA = 0.10 vol.% were 0.99 and 1.6 Ωcm2, respectively. The B-CEM showed higher dynamic transport numbers than those of the R-CEMs with similar membrane resistances.
  10. Taha BA, Al Mashhadany Y, Bachok NN, Ashrif A Bakar A, Hafiz Mokhtar MH, Dzulkefly Bin Zan MS, et al.
    Diagnostics (Basel), 2021 Jun 19;11(6).
    PMID: 34205401 DOI: 10.3390/diagnostics11061119
    The propagation of viruses has become a global threat as proven through the coronavirus disease (COVID-19) pandemic. Therefore, the quick detection of viral diseases and infections could be necessary. This study aims to develop a framework for virus diagnoses based on integrating photonics technology with artificial intelligence to enhance healthcare in public areas, marketplaces, hospitals, and airfields due to the distinct spectral signatures from lasers' effectiveness in the classification and monitoring of viruses. However, providing insights into the technical aspect also helps researchers identify the possibilities and difficulties in this field. The contents of this study were collected from six authoritative databases: Web of Science, IEEE Xplore, Science Direct, Scopus, PubMed Central, and Google Scholar. This review includes an analysis and summary of laser techniques to diagnose COVID-19 such as fluorescence methods, surface-enhanced Raman scattering, surface plasmon resonance, and integration of Raman scattering with SPR techniques. Finally, we select the best strategies that could potentially be the most effective methods of reducing epidemic spreading and improving healthcare in the environment.
  11. Chua BL, Baek SH, Park K, Ahn DG
    Materials (Basel), 2021 Jun 19;14(12).
    PMID: 34205426 DOI: 10.3390/ma14123404
    Three-dimensional prototypes and final products are commonly fabricated using the material extrusion (ME) process in additive manufacturing applications. However, these prototypes and products are limited to a single material using the ME process due to technical challenges. Deposition of plastic on another dissimilar plastic substrate requires proper control of printing temperature during an ME process due to differences in melting temperatures of dissimilar plastics. In this paper, deposition of PLA filament on an ABS substrate during an ME process is investigated using finite element analysis. A heat transfer finite element (FE) model for the extrusion process is proposed to estimate the parameters of the ME machine for the formulation of a heat flux model. The effects of printing temperature and the stand-off distance on temperature distributions are investigated using the proposed FE model for the extrusion process. The heat flux model is implemented in a proposed heat transfer FE model of single bead deposition of PLA on an ABS plate. From this FE model of deposition, temperature histories during the ME deposition process are estimated. The results of temperature histories are compared with experiments. Using the calibrated FE model, a proper heating temperature of ABS for deposition of PLA is evaluated.
  12. Adnan NA, Halmi MIE, Abd Gani SS, Zaidan UH, Abd Shukor MY
    PMID: 34205553 DOI: 10.3390/ijerph18126644
    Predicting the crucial effect of single metal pollutants against the aquatic ecosystem has been highly debatable for decades. However, dealing with complex metal mixtures management in toxicological studies creates a challenge, as heavy metals may evoke greater toxicity on interactions with other constituents rather than individually low acting concentrations. Moreover, the toxicity mechanisms are different between short term and long term exposure of the metal toxicant. In this study, acute and chronic toxicity based on luminescence inhibition assay using newly isolated Photobacterium sp.NAA-MIE as the indicator are presented. Photobacterium sp.NAA-MIE was exposed to the mixture at a predetermined ratio of 1:1. TU (Toxicity Unit) and MTI (Mixture Toxic Index) approach presented the mixture toxicity of Hg2+ + Ag+, Hg2+ + Cu2+, Ag+ + Cu2+, Hg2+ + Ag+ + Cu2+, and Cd2+ + Cu2+ showed antagonistic effect over acute and chronic test. Binary mixture of Cu2+ + Zn2+ was observed to show additive effect at acute test and antagonistic effect at chronic test while mixture of Ni2+ + Zn2+ showing antagonistic effect during acute test and synergistic effect during chronic test. Thus, the strain is suitable and their use as bioassay to predict the risk assessment of heavy metal under acute toxicity without abandoning the advantage of chronic toxicity extrapolation.
  13. Selvarajan RS, Gopinath SCB, Zin NM, Hamzah AA
    Sensors (Basel), 2021 Jun 01;21(11).
    PMID: 34205852 DOI: 10.3390/s21113829
    The race towards the development of user-friendly, portable, fast-detection, and low-cost devices for healthcare systems has become the focus of effective screening efforts since the pandemic attack in December 2019, which is known as the coronavirus disease 2019 (COVID-19) pandemic. Currently existing techniques such as RT-PCR, antigen-antibody-based detection, and CT scans are prompt solutions for diagnosing infected patients. However, the limitations of currently available indicators have enticed researchers to search for adjunct or additional solutions for COVID-19 diagnosis. Meanwhile, identifying biomarkers or indicators is necessary for understanding the severity of the disease and aids in developing efficient drugs and vaccines. Therefore, clinical studies on infected patients revealed that infection-mediated clinical biomarkers, especially pro-inflammatory cytokines and acute phase proteins, are highly associated with COVID-19. These biomarkers are undermined or overlooked in the context of diagnosis and prognosis evaluation of infected patients. Hence, this review discusses the potential implementation of these biomarkers for COVID-19 electrical biosensing platforms. The secretion range for each biomarker is reviewed based on clinical studies. Currently available electrical biosensors comprising electrochemical and electronic biosensors associated with these biomarkers are discussed, and insights into the use of infection-mediated clinical biomarkers as prognostic and adjunct diagnostic indicators in developing an electrical-based COVID-19 biosensor are provided.
    MeSH terms: Humans; Biosensing Techniques*; Biomarkers; Pandemics
  14. Rahman MS, Naima RL, Shetu KJ, Hossain MM, Kaiser MS, Hosen ASMS, et al.
    Biosensors (Basel), 2021 Jun 01;11(6).
    PMID: 34205927 DOI: 10.3390/bios11060178
    The use of deoxyribonucleic acid (DNA) hybridization to detect disease-related gene expression is a valuable diagnostic tool. An ion-sensitive field-effect transistor (ISFET) with a graphene layer has been utilized for detecting DNA hybridization. Silicene is a two-dimensional silicon allotrope with structural properties similar to graphene. Thus, it has recently experienced intensive scientific research interest due to its unique electrical, mechanical, and sensing characteristics. In this paper, we proposed an ISFET structure with silicene and electrolyte layers for the label-free detection of DNA hybridization. When DNA hybridization occurs, it changes the ion concentration in the surface layer of the silicene and the pH level of the electrolyte solution. The process also changes the quantum capacitance of the silicene layer and the electrical properties of the ISFET device. The quantum capacitance and the corresponding resonant frequency readout of the silicene and graphene are compared. The performance evaluation found that the changes in quantum capacitance, resonant frequency, and tuning ratio indicate that the sensitivity of silicene is much more effective than graphene.
    MeSH terms: Computer Simulation; DNA/chemistry; Graphite/chemistry; Silicon/chemistry; Transistors, Electronic; DNA Probes*; Biosensing Techniques; Electric Capacitance
  15. Mohamed Sa'dom SAF, Raikundalia S, Shamsuddin S, See Too WC, Few LL
    Genes (Basel), 2021 06 01;12(6).
    PMID: 34205960 DOI: 10.3390/genes12060853
    Choline kinase (CK) is the enzyme catalyzing the first reaction in CDP-choline pathway for the biosynthesis of phosphatidylcholine. Higher expression of the α isozyme of CK has been implicated in carcinogenesis, and inhibition or downregulation of CKα (CHKA) is a promising anticancer approach. This study aimed to investigate the regulation of CKα expression by DNA methylation of the CpG islands found on the promoter of this gene in MCF-7 cells. Four CpG islands have been predicted in the 2000 bp promoter region of ckα (chka) gene. Six CpG island deletion mutants were constructed using PCR site-directed mutagenesis method and cloned into pGL4.10 vectors for promoter activity assays. Deletion of CpG4C region located between -225 and -56 significantly increased the promoter activity by 4-fold, indicating the presence of important repressive transcription factor binding site. The promoter activity of methylated full-length promoter was significantly lower than the methylated CpG4C deletion mutant by 16-fold. The results show that DNA methylation of CpG4C promotes the binding of the transcription factor that suppresses the promoter activity. Electrophoretic mobility shift assay analysis showed that cytosine methylation at MZF1 binding site in CpG4C increased the binding of putative MZF1 in nuclear extract. In conclusion, the results suggest that DNA methylation decreased the promoter activity by promoting the binding of putative MZF1 transcription factor at CpG4C region of the ckα gene promoter.
    MeSH terms: Choline Kinase/genetics*; Humans; Mutation; Promoter Regions, Genetic; Gene Expression Regulation, Neoplastic; CpG Islands; DNA Methylation*; MCF-7 Cells
  16. Mok WKH, Hairi NN, Chan CMH, Mustapha FI, Saminathan TA, Low WY
    PMID: 34206056 DOI: 10.3390/ijerph18115950
    (1) Background: The prevalence of overweight and obesity among children has increased tremendously in the ASEAN region, including Malaysia. In Malaysia, the National Strategic Plan for Non-Communicable Diseases (2015-2025) provides the overall framework for its response to the non-communicable diseases (NCD) epidemic. Preventing childhood obesity is one of the key strategies for early intervention to prevent NCDs. The objective of this research is to examine the current status of policy interventions in addressing childhood obesity in Malaysia. (2) Methods: A panel of 22 stakeholders and experts from Malaysia, representing the government, industry, academia and non-governmental organizations, were sampled using a modified Delphi technique. Data were collected using a modified NCD scorecard under four domains (governance, risk factors, surveillance and research and health systems response). A heat map was used to measure the success of the four realms of the NCD scorecard. For each domain of the NCD scorecard, the final score was grouped in quintiles. (3) Results: A total of 22 participants responded, comprising of eight (36.4%) males and 14 (63.4%) females. All the domains measured in implementing policies related to childhood obesity were of low progress. Nine governance indicators were reported as 22.5% (low progress), four in the risk factors domain, and two in the surveillance. This shows that timely and accurate monitoring, participatory review and evaluation, and effective remedies are necessary for a country's surveillance system. (4) Conclusion: Although Malaysia has published several key strategic documents relating to childhood obesity and implemented numerous policy interventions, we have identified several gaps that must be addressed to leverage the whole-of-government and whole-of-society approach in addressing childhood obesity in the country.
    MeSH terms: Child; Female; Health Policy; Humans; Malaysia/epidemiology; Male; Policy Making
  17. Hashim UR, Jumahat A, Jawaid M
    Nanomaterials (Basel), 2021 Jun 01;11(6).
    PMID: 34206085 DOI: 10.3390/nano11061468
    Basalt fibre (BF) is one of the most promising reinforcing natural materials for polymer composites that could replace the usage of glass fibre due to its comparable properties. The aim of adding nanofiller in polymer composites is to enhance the mechanical properties of the composites. In theory, the incorporation of high strength and stiffness nanofiller, namely graphene nanoplatelet (GNP), could create superior composite properties. However, the main challenges of incorporating this nanofiller are its poor dispersion state and aggregation in epoxy due to its high surface area and strong Van der Waals forces in between graphene sheets. In this study, we used one of the effective methods of functionalization to improve graphene's dispersion and also introducing nanosilica filler to enhance platelets shear mechanism. The high dispersive silica nanospheres were introduced in the tactoids morphology of stacked graphene nanosheets in order to produce high shear forces during milling and exfoliate the GNP. The hybrid nanofiller modified epoxy polymers were impregnated into BF to evaluate the mechanical properties of the basalt fibre reinforced polymeric (BFRP) system under tensile, compression, flexural, and drop-weight impact tests. In response to the synergistic effect of zero-dimensional nanosilica and two-dimensional graphene nanoplatelets enhanced the mechanical properties of BFRP, especially in Basalt fibre + 0.2 wt% GNP/15 wt% NS (BF-H0.2) with the highest increment in modulus and strength to compare with unmodified BF. These findings also revealed that the incorporation of hybrid nanofiller contributed to the improvement in the mechanical properties of the composite. BF has huge potential as an alternative to the synthetic glass fibre for the fabrication of mechanical components and structures.
  18. Khan A, Jawaid M, Kian LK, Khan AAP, Asiri AM
    Polymers (Basel), 2021 Jun 01;13(11).
    PMID: 34206136 DOI: 10.3390/polym13111835
    Conocarpus fiber is a lignocellulosic biomass rich in cellulose potentially used for producing nanocrystalline cellulose (NCC), a biomaterial extensively employed in various application fields. In the present work, different hydrolysis times of 10, 20 and 30 min were applied to chemically pre-treated Conocarpus fiber to produce CPNC1, CPNC2, and CPNC3 particles. With acid hydrolysis treatment, the yield of NCC product was successfully retained at 17-19%. Individual, rod-like shapes of NCC particles could be clearly observed under microscopy examination. From chemical composition analysis, a relatively pure cellulose compartment was produced for all NCC samples with substantial removal of lignin and hemicellulose. The physicochemical analysis proved that each nanoparticle sample possessed strong cellulose crystalline structure. For thermal analyses, the heat resistance of NCCs was gradually enhanced with the increased hydrolysis times. Therefore, the extracted NCC product from Conocarpus fiber could be a green nano-filler for developing nanocomposite material in the future.
  19. Abdullah MN, Mustapha M, Sallih N, Ahmad A, Mustapha F, Dahliyanti A
    Materials (Basel), 2021 Jun 22;14(13).
    PMID: 34206150 DOI: 10.3390/ma14133440
    The utilisation of rice husk ash (RHA) as an aluminosilicate source in fire-resistant coating could reduce environmental pollution and can turn agricultural waste into industrial wealth. The overall objective of this research is to develop a rice-husk-ash-based geopolymer binder (GB) fire-retardant additive (FR) for alkyd paint. Response surface methodology (RSM) was used to design the experiments work, on the ratio of RHA-based GB to alkyd paint. The microstructure behaviour and material characterisation of the coating samples were studied through SEM analysis. The optimal RHA-based GB FR additive was formulated at 50% wt. FR and 82.628% wt. paint. This formulation showed the result of 270 s to reach 200 °C and 276 °C temperature at equilibrium for thermal properties. Furthermore, it was observed that the increased contents of RHA showed an increment in terms of the total and open porosities and rough surfaces, in which the number of pores on the coating surface plays an important role in the formation of the intumescent char layer. By developing the optimum RHA-based GB to paint formulation, the coating may potentially improve building fire safety through passive fire protection.
  20. Shahriar SA, Islam MN, Chun CNW, Rahim MA, Paul NC, Uddain J, et al.
    Plants (Basel), 2021 Jun 22;10(7).
    PMID: 34206201 DOI: 10.3390/plants10071264
    Protecting food crops from viral pathogens is a significant challenge for agriculture. An integral approach to genome-editing, known as CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats and CRISPR associated protein 9), is used to produce virus-resistant cultivars. The CRISPR/Cas9 tool is an essential part of modern plant breeding due to its attractive features. Advances in plant breeding programs due to the incorporation of Cas9 have enabled the development of cultivars with heritable resistance to plant viruses. The resistance to viral DNA and RNA is generally provided using the Cas9 endonuclease and sgRNAs (single-guide RNAs) complex, targeting particular virus and host plant genomes by interrupting the viral cleavage or altering the plant host genome, thus reducing the replication ability of the virus. In this review, the CRISPR/Cas9 system and its application to staple food crops resistance against several destructive plant viruses are briefly described. We outline the key findings of recent Cas9 applications, including enhanced virus resistance, genetic mechanisms, research strategies, and challenges in economically important and globally cultivated food crop species. The research outcome of this emerging molecular technology can extend the development of agriculture and food security. We also describe the information gaps and address the unanswered concerns relating to plant viral resistance mediated by CRISPR/Cas9.
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