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  1. Fulltext The Effect of Welding Current and Electrode Force on the Heat Input, Weld Diameter, and Physical and Mechanical Properties of SS316L/Ti6Al4V Dissimilar Resistance Spot Welding with Aluminum Interlayer
    Taufiqurrahman I, Ahmad A, Mustapha M, Lenggo Ginta T, Ady Farizan Haryoko L, Ahmed Shozib I
    Materials (Basel), 2021 Feb 27;14(5).
    PMID: 33673716 DOI: 10.3390/ma14051129
    Welding parameters obviously determine the joint quality during the resistance spot welding process. This study aimed to investigate the effect of welding current and electrode force on the heat input and the physical and mechanical properties of a SS316L and Ti6Al4V joint with an aluminum interlayer. The weld current values used in this study were 11, 12, and 13 kA, while the electrode force values were 3, 4, and 5 kN. Welding time and holding time remained constant at 30 cycles. The study revealed that, as the welding current and electrode force increased, the generated heat input increased significantly. The highest tensile-shear load was recorded at 8.71 kN using 11 kA of weld current and 3 kN of electrode force. The physical properties examined the formation of a brittle fracture and several weld defects on the high current welded joint. The increase in weld current also increased the weld diameter. The microstructure analysis revealed no phase transformation on the SS316L interface; instead, the significant grain growth occurred. The phase transformation has occurred on the Ti6Al4V interface. The intermetallic compound layer was also investigated in detail using the EDX (Energy Dispersive X-Ray) and XRD (X-Ray Diffraction) analyses. It was also found that both stainless steel and titanium alloy have their own fusion zone, which is indicated by the highest microhardness value.
    Matched MeSH terms: Hot Temperature
  2. Modeling and optimization of lipase-catalyzed production of succinic acid ester using central composite design analysis
    Abdul Rahman MB, Jarmi NI, Chaibakhsh N, Basri M
    J Ind Microbiol Biotechnol, 2011 Jan;38(1):229-34.
    PMID: 20803246 DOI: 10.1007/s10295-010-0817-3
    Esterification of succinic acid with oleyl alcohol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was investigated in this study. Response surface methodology (RSM) based on a five-level, four-variable central composite design (CCD) was used to model and analyze the reaction. A total of 21 experiments representing different combinations of the four parameters including temperature (35-65°C), time (30-450 min), enzyme amount (20-400 mg), and alcohol:acid molar ratio (1:1-8:1) were generated. A partial cubic equation could accurately model the response surface with a R(2) of 0.9853. The effect and interactions of the variables on the ester synthesis were also studied. Temperature was found to be the most significant parameter that influenced the succinate ester synthesis. At the optimal conditions of 41.1°C, 272.8 min, 20 mg enzyme amount and 7.8:1 alcohol:acid molar ratio, the esterification percentage was 85.0%. The model can present a rapid means for estimating the conversion yield of succinate ester within the selected ranges.
    Matched MeSH terms: Temperature
  3. Fulltext Isolation and Characterization of Six Vibrio parahaemolyticus Lytic Bacteriophages From Seafood Samples
    Tan CW, Rukayadi Y, Hasan H, Abdul-Mutalib NA, Jambari NN, Hara H, et al.
    Front Microbiol, 2021;12:616548.
    PMID: 33776954 DOI: 10.3389/fmicb.2021.616548
    Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of seafood. To control this pathogenic Vibrio spp., the implementation of bacteriophages in aquaculture and food industries have shown a promising alternative to antibiotics. In this study, six bacteriophages isolated from the seafood samples demonstrated a narrow host range specificity that infecting only the V. parahaemolyticus strains. Morphological analysis revealed that bacteriophages Vp33, Vp22, Vp21, and Vp02 belong to the Podoviridae family, while bacteriophages Vp08 and Vp11 were categorized into the Siphoviridae family. All bacteriophages were composed of DNA genome and showed distinctive restriction fragment length polymorphism. The optimal MOI for bacteriophage propagation was determined to be 0.001 to 1. One-step growth curve revealed that the latent period ranged from 10 to 20 min, and the burst size of bacteriophage was approximately 17 to 51 PFU/cell. The influence of temperature and pH levels on the stability of bacteriophages showed that all bacteriophages were optimally stable over a wide range of temperatures and pH levels. In vitro lytic activity of all bacteriophages demonstrated to have a significant effect against V. parahaemolyticus. Besides, the application of a bacteriophage cocktail instead of a single bacteriophage suspension was observed to have a better efficiency to control the growth of V. parahaemolyticus. Results from this study provided a basic understanding of the physiological and biological properties of the isolated bacteriophages before it can be readily used as a biocontrol agent against the growth of V. parahaemolyticus.
    Matched MeSH terms: Temperature
  4. Comparative modelling studies of fruit bromelain using molecular dynamics simulation
    Pang WC, Ramli ANM, Hamid AAA
    J Mol Model, 2020 May 16;26(6):142.
    PMID: 32417971 DOI: 10.1007/s00894-020-04398-1
    Fruit bromelain is a cysteine protease accumulated in pineapple fruits. This proteolytic enzyme has received high demand for industrial and therapeutic applications. In this study, fruit bromelain sequences QIM61759, QIM61760 and QIM61761 were retrieved from the National Center for Biotechnology Information (NCBI) Genbank Database. The tertiary structure of fruit bromelain QIM61759, QIM61760 and QIM61761 was generated by using MODELLER. The result revealed that the local stereochemical quality of the generated models was improved by using multiple templates during modelling process. Moreover, by comparing with the available papain model, structural analysis provides an insight on how pro-peptide functions as a scaffold in fruit bromelain folding and contributing to inactivation of mature protein. The structural analysis also disclosed the similarities and differences between these models. Lastly, thermal stability of fruit bromelain was studied. Molecular dynamics simulation of fruit bromelain structures at several selected temperatures demonstrated how fruit bromelain responds to elevation of temperature.
    Matched MeSH terms: Hot Temperature
  5. Fulltext Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature
    Gupta M, Hawari HF, Kumar P, Burhanudin ZA, Tansu N
    Nanomaterials (Basel), 2021 Mar 03;11(3).
    PMID: 33802318 DOI: 10.3390/nano11030623
    The demand for carbon dioxide (CO2) gas detection is increasing nowadays. However, its fast detection at room temperature (RT) is a major challenge. Graphene is found to be the most promising sensing material for RT detection, owing to its high surface area and electrical conductivity. In this work, we report a highly edge functionalized chemically synthesized reduced graphene oxide (rGO) thin films to achieve fast sensing response for CO2 gas at room temperature. The high amount of edge functional groups is prominent for the sorption of CO2 molecules. Initially, rGO is synthesized by reduction of GO using ascorbic acid (AA) as a reducing agent. Three different concentrations of rGO are prepared using three AA concentrations (25, 50, and 100 mg) to optimize the material properties such as functional groups and conductivity. Thin films of three different AA reduced rGO suspensions (AArGO25, AArGO50, AArGO100) are developed and later analyzed using standard FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurement techniques. We find that the highest edge functionality is achieved by the AArGO25 sample with a conductivity of ~1389 S/cm. The functionalized AArGO25 gas sensor shows recordable high sensing properties (response and recovery time) with good repeatability for CO2 at room temperature at 500 ppm and 50 ppm. Short response and recovery time of ~26 s and ~10 s, respectively, are achieved for 500 ppm CO2 gas with the sensitivity of ~50 Hz/µg. We believe that a highly functionalized AArGO CO2 gas sensor could be applicable for enhanced oil recovery, industrial and domestic safety applications.
    Matched MeSH terms: Temperature
  6. Enhanced crystallinity and thermal properties of cellulose from rice husk using acid hydrolysis treatment
    Hafid HS, Omar FN, Zhu J, Wakisaka M
    Carbohydr Polym, 2021 May 15;260:117789.
    PMID: 33712137 DOI: 10.1016/j.carbpol.2021.117789
    Cellulose was extracted from rice husk (RH) using an integrated delignification process using alkaline treatment and acid hydrolysis (concentrated HNO3) for lignocellulosic biomass dissolution. Cellulose yield and quality were assessed through analysis of lignocellulosic content, thermogravimetric, functional group, X-ray diffraction, and surface morphology. HNO3 treatment showed an increment (2.01-fold) in the cellulose content and some enhancement in the crystallinity of cellulose (up to 40.8%). A slight increase was observed in thermal properties from 334.6 °C to 339.3 °C. Economic analysis showed chlorine extraction produce higher cellulose recovery (58%) as compared to HNO3 (26.7%) with the total cost of operation using HNO3 was double compared to chlorine extraction. The economic feasibility of HNO3 can be improved using various progress in the pre-treatment process, chemical recycling and cellulose recovery process since adopting it is crucial for environmental sustainability.
    Matched MeSH terms: Temperature
  7. Fulltext Comparison of Hook and Straight Steel Fibers Addition on Malaysian Fly Ash-Based Geopolymer Concrete on the Slump, Density, Water Absorption and Mechanical Properties
    Faris MA, Abdullah MMAB, Muniandy R, Abu Hashim MF, Błoch K, Jeż B, et al.
    Materials (Basel), 2021 Mar 09;14(5).
    PMID: 33803313 DOI: 10.3390/ma14051310
    Geopolymer concrete has the potential to replace ordinary Portland cement which can reduce carbon dioxide emission to the environment. The addition of different amounts of steel fibers, as well as different types of end-shape fibers, could alter the performance of geopolymer concrete. The source of aluminosilicate (fly ash) used in the production of geopolymer concrete may lead to a different result. This study focuses on the comparison between Malaysian fly ash geopolymer concrete with the addition of hooked steel fibers and geopolymer concrete with the addition of straight-end steel fibers to the physical and mechanical properties. Malaysian fly ash was first characterized by X-ray fluorescence (XRF) to identify the chemical composition. The sample of steel fiber reinforced geopolymer concrete was produced by mixing fly ash, alkali activators, aggregates, and specific amounts of hook or straight steel fibers. The steel fibers addition for both types of fibers are 0%, 0.5%, 1.0%, 1.5%, and 2.0% by volume percentage. The samples were cured at room temperature. The physical properties (slump, density, and water absorption) of reinforced geopolymer concrete were studied. Meanwhile, a mechanical performance which is compressive, as well as the flexural strength was studied. The results show that the pattern in physical properties of geopolymer concrete for both types of fibers addition is almost similar where the slump is decreased with density and water absorption is increased with the increasing amount of fibers addition. However, the addition of hook steel fiber to the geopolymer concrete produced a lower slump than the addition of straight steel fibers. Meanwhile, the addition of hook steel fiber to the geopolymer concrete shows a higher density and water absorption compared to the sample with the addition of straight steel fibers. However, the difference is not significant. Besides, samples with the addition of hook steel fibers give better performance for compressive and flexural strength compared to the samples with the addition of straight steel fibers where the highest is at 1.0% of fibers addition.
    Matched MeSH terms: Temperature
  8. Fulltext Prevalence and characteristics of fever in adult and paediatric patients with coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis of 17515 patients
    Islam MA, Kundu S, Alam SS, Hossan T, Kamal MA, Hassan R
    PLoS One, 2021;16(4):e0249788.
    PMID: 33822812 DOI: 10.1371/journal.pone.0249788
    BACKGROUND: Coronavirus disease 2019 (COVID-19), a pandemic disease caused by the severe acute respiratory syndrome coronavirus 2 started to spread globally since December 2019 from Wuhan, China. Fever has been observed as one of the most common clinical manifestations, although the prevalence and characteristics of fever in adult and paediatric COVID-19 patients is inconclusive. We aimed to conduct a systematic review and meta-analysis to estimate the overall pooled prevalence of fever and chills in addition to fever characteristics (low, medium, and high temperature) in both adult and paediatric COVID-19 patients.

    METHODS: The protocol of this systematic review and meta-analysis was registered with PROSPERO (CRD42020176327). PubMed, Scopus, ScienceDirect and Google Scholar databases were searched between 1st December 2019 and 3rd April 2020 without language restrictions. Both adult (≥18 years) and paediatric (<18 years) COVID-19 patients were considered eligible. We used random-effects model for the meta-analysis to obtain the pooled prevalence and risk ratio (RR) with 95% confidence intervals (CIs). Quality assessment of included studies was performed using the Joanna Briggs Institute critical appraisal tools. Heterogeneity was assessed using the I² statistic and Cochran's Q test. Robustness of the pooled estimates was checked by different subgroups and sensitivity analyses.

    RESULTS: We identified 2055 studies, of which 197 studies (n = 24266) were included in the systematic review and 167 studies with 17142 adults and 373 paediatrics were included in the meta-analysis. Overall, the pooled prevalence of fever in adult and paediatric COVID-19 patients were 79.43% [95% CI: 77.05-81.80, I2 = 95%] and 45.86% [95% CI: 35.24-56.48, I2 = 78%], respectively. Besides, 14.45% [95% CI: 10.59-18.32, I2 = 88%] of the adult COVID-19 patients were accompanied with chills. In adult COVID-19 patients, the prevalence of medium-grade fever (44.33%) was higher compared to low- (38.16%) and high-grade fever (14.71%). In addition, the risk of both low (RR: 2.34, 95% CI: 1.69-3.22, p<0.00001, I2 = 84%) and medium grade fever (RR: 2.79, 95% CI: 2.21-3.51, p<0.00001, I2 = 75%) were significantly higher compared to high-grade fever, however, there was no significant difference between low- and medium-grade fever (RR: 1.17, 95% CI: 0.94-1.44, p = 0.16, I2 = 87%). 88.8% of the included studies were of high-quality. The sensitivity analyses indicated that our findings of fever prevalence for both adult and paediatric patients are reliable and robust.

    CONCLUSIONS: The prevalence of fever in adult COVID-19 patients was high, however, 54.14% of paediatric COVID-19 patients did not exhibit fever as an initial clinical feature. Prevalence and risk of low and medium-grade fevers were higher compared to high-grade fever.

    Matched MeSH terms: Temperature
  9. Citizen science frontiers horseshoe crab population regain at their spawning beach in East Peninsular Malaysia
    Mat Zauki NA, Satyanarayana B, Fairuz-Fozi N, Nelson BR, Martin MB, Akbar-John B, et al.
    J Environ Manage, 2019 Feb 15;232:1012-1020.
    PMID: 33395753 DOI: 10.1016/j.jenvman.2018.12.002
    Carcinoscorpius rotundicauda and Tachypleus gigas may co-exist and share common spawning grounds elsewhere but at Balok (East Coast of Peninsular Malaysia), C. rotundicauda is an understudied species. Neglected as research candidate because of inaccessible spawning grounds, smaller size and less commercial value than T. gigas and also, difficulty to attain from the wild has made C. rotundicauda population status remaining unidentified at Balok. This standpoint drove the present attempt because anthropic activities like structure placement and mining are point-source for runoffs that load sediments into Balok River. While erosion-accretion events have altered Balok River width, the shore sediments in Balok Beach were transitioned between medium-fine and fine sand between years 2012 and 2016. Eventually by year 2016, the C. rotundicauda were depositing 5117 eggs in 91 nests from 200 to 1000 m range along this corridor facing South China Sea. From this yield, C. rotundicauda released 2880 eggs in 56 nests during the Southwest monsoon, 1254 eggs in 19 nests during the Northeast monsoon and 983 eggs in 16 nests during the Inter-monsoon seasons. Though female C. rotundicauda opted to lay their eggs in shallow burrows at lower shorelines, the absence of erosion and substantial silt and clay (>20%) deposition facilitates C. rotundicauda embryogenesis with brief periods of temperature and salinity shocks during day-time falling tides. This encourages C. rotundicauda to emerge with increasing abundance and carry out bi-monthly spawning at Balok Beach. In short, shore restoration initiatives like systematic boat docking, proper disposal of nets and waste and, periodic fish-catching operations were effectively led by the Balok fisher citizen scientist. This successful community joint-cooperation proves that citizen-led caretaking of degraded beaches offers marine life protection and are practical for coastal area management especially at areas where other oviparous animals such as turtles and crocodiles are harboured.
    Matched MeSH terms: Temperature
  10. 3-Chloropropane-1,2-diol (3-MCPD) in Soy Sauce: A Review on the Formation, Reduction, and Detection of This Potential Carcinogen
    Lee BQ, Khor SM
    Compr Rev Food Sci Food Saf, 2015 Jan;14(1):48-66.
    PMID: 33401813 DOI: 10.1111/1541-4337.12120
    Soy sauce, a dark-colored seasoning, is added to enhance the sensory properties of foods. Soy sauce can be consumed as a condiment or added during the preparation of food. There are 3 types of soy sauce: fermented, acid-hydrolyzed vegetable protein (acid- HVP), and mixtures of these. 3-Chloropropane-1,2-diol (3-MCPD) is a heat-produced contaminants formed during the preparation of soy sauce and was found to be a by-product of acid-HVP-produced soy sauce in 1978. 3-MCPD has been reported to be carcinogenic, nephrotoxic, and reproductively toxic in laboratory animal testing and has been registered as a chemosterilant for rodent control. 3-MCPD is classified as a possible carcinogenic compound, and the maximum tolerated limit in food has been established at both national and international levels. The purpose of this review is to provide an overview on the detection of 3-MCPD in soy sauce, its toxic effects, and the potential methods to reduce its concentration, especially during the production of acid-HVP soy sauce. The methods of quantification are also critically reviewed with a focus on efficiency, suitability, and challenges encountered in analysis.
    Matched MeSH terms: Hot Temperature
  11. Fulltext Megalocytiviruses in ornamental fish: A review
    Johan CAC, Zainathan SC
    Vet World, 2020 Nov;13(11):2565-2577.
    PMID: 33363355 DOI: 10.14202/vetworld.2020.2565-2577
    Iridoviruses, especially megalocytiviruses, are related to severe disease resulting in high economic losses in the aquaculture industry worldwide. The ornamental fish industry has been affected severely due to Megalocytivirus infections. Megalocytivirus is a DNA virus that has three genera; including red sea bream iridovirus, infectious spleen and kidney necrosis virus, and turbot reddish body iridovirus. Megalocytivirus causes non-specific clinical signs in ornamental fish. Cell culture, histology, immunofluorescence test, polymerase chain reaction (PCR) assay, and loop-mediated isothermal amplification assay have been used to diagnose megalocytiviruses. Risk factors such as temperature, transportation (export and import), and life stages of ornamental fish have been reported for the previous cases due to Megalocytivirus infections. In addition, other prevention and control methods also have been practiced in farms to prevent Megalocytivirus outbreaks. This is the first review of megalocytiviruses in ornamental fish since its first detection in 1989. This review discusses the occurrences of Megalocytivirus in ornamental fish, including the history, clinical signs, detection method, risk factors, and prevention measures.
    Matched MeSH terms: Temperature
  12. Fulltext Antioxidant and anti-inflammatory properties of Erythroxylum cuneatum alkaloid leaf extract
    Li LS, Chiroma SM, Hashim T, Adam SK, Mohd Moklas MA, Yusuf Z, et al.
    Heliyon, 2020 Jun;6(6):e04141.
    PMID: 32637674 DOI: 10.1016/j.heliyon.2020.e04141
    Erythroxylum cuneatum (E. cuneatum) which belongs to Erythroxylaceae family is a tropical flowering plant from the genus of Erythroxylum. It is used in Malaysia and Thailand's traditional medicines, yet there is limited scientific reports on its medicinal value. This study aimed at exploring the antioxidative and anti-inflammatory properties of E. cuneatum alkaloid leaf extract. The alkaloid extract was obtained through Soxhlet heat extraction method, while the antioxidantive properties were assessed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, ferric reducing antioxidant power (FRAP) and xanthine oxidase inhibition (XOI) assays. Further, anti-inflammatory property of the extract was evaluated on rat's model of carrageenan induced paw model of edema via physical measurements and histology. The extract exhibited antioxidant activity with an EC50 value of 1482 μg/ml in the DPPH radical scavenging assay, an EC1 value of 2191 μg/ml in the FRAP assay and 10.15 ± 6.20% in the XOI assay. Rats pretreated with the extract have shown dose dependent decrease in paw edema when compared to non-treated group of rats. The highest dose (50 mg/kg) of extract exhibited similar effects to aspirin in terms of reducing paw thickness, leucocytes infiltration and disruption of collagen. In conclusion, the E. cuneatum alkaloid leaf extract possesses both antioxidative and anti-inflammatory properties suggesting its potentials for future development of antioxidant and anti-inflammatory drugs.
    Matched MeSH terms: Hot Temperature
  13. Fulltext Data set on trace metals in surface sediment and water from a sub-tropical estuarine system, Bay of Bengal, Bangladesh
    Hossain MB, Habib SB, Hossain MS, Jolly YN, Kamal AHM, Idris MH, et al.
    Data Brief, 2020 Aug;31:105911.
    PMID: 32637507 DOI: 10.1016/j.dib.2020.105911
    Meghna River Estuary, the largest estuarine system (GBM, Ganges-Brahmaputra-Meghna) in Bangladesh, is a major spawning ground of national fish, Hilsha shad. In this study, we collected 24 surface sediment and 24 water samples from the entire lower estuary (4 sites, 3 sampling points from each site, 2 replicas from each sampling point) to detect trace/heavy metals. Sediment samples were collected from the top surface soil (0-5 cm) using Ekman grab sampler and water samples from 5 cm below the surface layer using plastic water bottles. After collection, sediment and water samples were preserved as necessary using HNO3 (for water). Immediately after reaching the laboratory, sediment samples were dried in an oven at 70°C until the constant weight gained. The metals were then analyzed using energy-dispersive X-ray fluorescence method (EDXRF) and calculated the metal concentrations. In total, 12 metals were detected and the average value (mg/Kg) of all metals for sediment samples followed the descending order of Fe > Ca > K >Ti >Sr >Zr >Rb> Cu > Zn >Pb >As > Ni, and for water the order (µg/mL) of Fe >Ti > Ca > Co >Mn > Ni > Zn >Sr > Cu > As > Se . Besides, several physicochemical parameters i.e. water pH, soil pH, temperature, salinity, dissolved oxygen, hardness, and alkalinity of the 12 sampling points were also measured in-situ using handheld instruments.
    Matched MeSH terms: Temperature
  14. Fulltext Numerical analysis of thermal conductive hybrid nanofluid flow over the surface of a wavy spinning disk
    Ahmadian A, Bilal M, Khan MA, Asjad MI
    Sci Rep, 2020 Nov 02;10(1):18776.
    PMID: 33139760 DOI: 10.1038/s41598-020-75905-w
    A three dimensional (3D) numerical solution of unsteady, Ag-MgO hybrid nanoliquid flow with heat and mass transmission caused by upward/downward moving of wavy spinning disk has been scrutinized. The magnetic field has been also considered. The hybrid nanoliquid has been synthesized in the presence of Ag-MgO nanoparticles. The purpose of the study is to improve the rate of thermal energy transmission for several industrial purposes. The wavy rotating surface increases the heat transmission rate up to 15%, comparatively to the flat surface. The subsequent arrangement of modeled equations is diminished into dimensionless differential equation. The obtained system of equations is further analytically expounded via Homotopy analysis method HAM and the numerical Parametric continuation method (PCM) method has been used for the comparison of the outcomes. The results are graphically presented and discussed. It has been presumed that the geometry of spinning disk positively affects the velocity and thermal energy transmission. The addition of hybrid nanoparticles (silver and magnesium-oxide) significantly improved thermal property of carrier fluid. It uses is more efficacious to overcome low energy transmission. Such as, it provides improvement in thermal performance of carrier fluid, which play important role in power generation, hyperthermia, micro fabrication, air conditioning and metallurgical field.
    Matched MeSH terms: Hot Temperature
  15. Fulltext Synthesis and characterization of rice husk biochar via hydrothermal carbonization for wastewater treatment and biofuel production
    Hossain N, Nizamuddin S, Griffin G, Selvakannan P, Mubarak NM, Mahlia TMI
    Sci Rep, 2020 Nov 02;10(1):18851.
    PMID: 33139793 DOI: 10.1038/s41598-020-75936-3
    The recent implication of circular economy in Australia spurred the demand for waste material utilization for value-added product generations on a commercial scale. Therefore, this experimental study emphasized on agricultural waste biomass, rice husk (RH) as potential feedstock to produce valuable products. Rice husk biochar (RB) was obtained at temperature: 180 °C, pressure: 70 bar, reaction time: 20 min with water via hydrothermal carbonization (HTC), and the obtained biochar yield was 57.9%. Enhancement of zeta potential value from - 30.1 to - 10.6 mV in RB presented the higher suspension stability, and improvement of surface area and porosity in RB demonstrated the wastewater adsorption capacity. Along with that, an increase of crystallinity in RB, 60.5%, also indicates the enhancement of the catalytic performance of the material significantly more favorable to improve the adsorption efficiency of transitional compounds. In contrast, an increase of the atomic O/C ratio in RB, 0.51 delineated high breakdown of the cellulosic component, which is favorable for biofuel purpose. 13.98% SiO2 reduction in RB confirmed ash content minimization and better quality of fuel properties. Therefore, the rice husk biochar through HTC can be considered a suitable material for further application to treat wastewater and generate bioenergy.
    Matched MeSH terms: Temperature
  16. Fulltext Fabrication of Bio-Based Gelatin Sponge for Potential Use as A Functional Acellular Skin Substitute
    Arif MMA, Fauzi MB, Nordin A, Hiraoka Y, Tabata Y, Yunus MHM
    Polymers (Basel), 2020 Nov 13;12(11).
    PMID: 33202700 DOI: 10.3390/polym12112678
    Gelatin possesses biological properties that resemble native skin and can potentially be fabricated as a skin substitute for full-thickness wound treatment. The native property of gelatin, whereby it is easily melted and degraded at body temperature, could prevent its biofunctionality for various applications. This study aimed to fabricate and characterise buffalo gelatin (Infanca halal certified) crosslinked with chemical type crosslinker (genipin and genipin fortified with EDC) and physicaly crosslink using the dihydrothermal (DHT) method. A porous gelatin sponge (GS) was fabricated by a freeze-drying process followed by a complete crosslinking via chemical-natural and synthetic-or physical intervention using genipin (GNP), 1-ethyl-3-(3-dimethylaminopropyl) (EDC) and dihydrothermal (DHT) methods, respectively. The physicochemical, biomechanical, cellular biocompatibility and cell-biomaterial interaction of GS towards human epidermal keratinocytes (HEK) and dermal fibroblasts (HDF) were evaluated. Results showed that GS had a uniform porous structure with pore size ranging between 60 and 200 µm with high porosity (>78.6 ± 4.1%), high wettability (<72.2 ± 7.0°), high tensile strain (>13.65 ± 1.10%) and 14 h of degradation rate. An increase in the concentration and double-crosslinking approach demonstrated an increment in the crosslinking degree, enzymatic hydrolysis resistance, thermal stability, porosity, wettability and mechanical strength. The GS can be tuned differently from the control by approaching the GS via a different crosslinking strategy. However, a decreasing trend was observed in the pore size, water retention and water absorption ability. Crosslinking with DHT resulted in large pore sizes (85-300 µm) and low water retention (236.9 ± 18.7 g/m2·day) and a comparable swelling ratio with the control (89.6 ± 7.1%). Moreover no changes in the chemical content and amorphous phase identification were observed. The HEK and HDF revealed slight toxicity with double crosslinking. HEK and HDF attachment and proliferation remain similar to each crosslinking approach. Immunogenicity was observed to be higher in the double-crosslinking compared to the single-crosslinking intervention. The fabricated GS demonstrated a dynamic potential to be tailored according to wound types by manipulating the crosslinking intervention.
    Matched MeSH terms: Body Temperature
  17. Fulltext Salmonella-innovative targeting carrier: Loading with doxorubicin for cancer treatment
    Rabea S, Alanazi FK, Ashour AE, Salem-Bekhit MM, Yassin AS, Moneib NA, et al.
    Saudi Pharm J, 2020 Oct;28(10):1253-1262.
    PMID: 33132719 DOI: 10.1016/j.jsps.2020.08.016
    Cell- based targeted delivery is recently gain attention as a promising platform for delivery of anticancer drug in selective and efficient manner. As a new biotechnology platform, bacterial ghosts (BGs) have novel biomedical application as targeted drug delivery system (TDDS). In the current work, Salmonellas' BGs was utilized for the first time as hepatocellular cancer (HCC) in-vitro targeted delivery system. Successful BGs loading and accurate analysis of doxorubicin (DOX) were necessary steps for testing the applicability of DOX loaded BGs in targeting the liver cancer cells. Loading capacity was maximized to reach 27.5 µg/mg (27.5% encapsulation efficiency), by incubation of 10 mg BGs with 1 mg DOX at pH 9 in constant temperature (25 °C) for 10 min. In-vitro release study of DOX loaded BGs showed a sustained release (182 h) obeying Higuchi sustained kinetic release model. The death rate (tested by MTT assay) of HepG2 reached to 64.5% by using of 4 μg/ml, while it was about 51% using the same concentration of the free DOX (P value 
    Matched MeSH terms: Temperature
  18. Fulltext Effect of Aging, Antioxidant, and Mono- and Divalent Ions at High Temperature on the Rheology of New Polyacrylamide-Based Co-Polymers
    Akbari S, Mahmood SM, Tan IM, Ling OL, Ghaedi H
    Polymers (Basel), 2017 Oct 04;9(10).
    PMID: 30965788 DOI: 10.3390/polym9100480
    The viscosity of four new polymers was investigated for the effect of aging at high temperature, with varying degrees of salinity and hardness. The four sulfonated based polyacrylamide co-polymers were FLOCOMB C7035; AN132 VHM; SUPERPUSHER SAV55; and THERMOASSOCIATIF copolymers. All polymer samples were aged at 80 °C for varying times (from zero to at least 90 days) with and without isobutyl alcohol (IBA) as an antioxidant. To see the effect of divalent ions on the polymer solution viscosity, parallel experiments were performed in a mixture of CaCl₂-NaCl of the same ionic strength as 5 wt % NaCl. The polymers without IBA showed severe viscosity reduction after aging for 90 days in both types of preparation (5 wt % NaCl or CaCl₂-NaCl). In the presence of IBA, viscosity was increased when aging time was increased for 5 wt % NaCl. In CaCl₂-NaCl, on the other hand, a viscosity reduction was observed as aging time was increased. This behavior was observed for all polymers except AN132 VHM.
    Matched MeSH terms: Temperature
  19. Fulltext Microwave Hydrothermal Carbonization of Rice Straw: Optimization of Process Parameters and Upgrading of Chemical, Fuel, Structural and Thermal Properties
    Nizamuddin S, Qureshi SS, Baloch HA, Siddiqui MTH, Takkalkar P, Mubarak NM, et al.
    Materials (Basel), 2019 Jan 28;12(3).
    PMID: 30696042 DOI: 10.3390/ma12030403
    The process parameters of microwave-induced hydrothermal carbonization (MIHTC) play an important role on the hydrothermal chars (hydrochar) yield. The effect of reaction temperature, reaction time, particle size and biomass to water ratio was optimized for hydrochar yield by modeling using the central composite design (CCD). Further, the rice straw and hydrochar at optimum conditions have been characterized for energy, chemical, structural and thermal properties. The optimum condition for hydrochar synthesis was found to be at a 180 °C reaction temperature, a 20 min reaction time, a 1:15 weight per volume (w/v) biomass to water ratio and a 3 mm particle size, yielding 57.9% of hydrochar. The higher heating value (HHV), carbon content and fixed carbon values increased from 12.3 MJ/kg, 37.19% and 14.37% for rice straw to 17.6 MJ/kg, 48.8% and 35.4% for hydrochar. The porosity, crystallinity and thermal stability of the hydrochar were improved remarkably compared to rice straw after MIHTC. Two characteristic peaks from XRD were observed at 2θ of 15° and 26°, whereas DTG peaks were observed at 50⁻150 °C and 300⁻350 °C for both the materials. Based on the results, it can be suggested that the hydrochar could be potentially used for adsorption, carbon sequestration, energy and agriculture applications.
    Matched MeSH terms: Temperature
  20. Fulltext Immobilization of Peroxidase on Functionalized MWCNTs-Buckypaper/Polyvinyl alcohol Nanocomposite Membrane
    Jun LY, Mubarak NM, Yon LS, Bing CH, Khalid M, Jagadish P, et al.
    Sci Rep, 2019 02 18;9(1):2215.
    PMID: 30778111 DOI: 10.1038/s41598-019-39621-4
    Surface modified Multi-walled carbon nanotubes (MWCNTs) Buckypaper/Polyvinyl Alcohol (BP/PVA) composite membrane was synthesized and utilized as support material for immobilization of Jicama peroxidase (JP). JP was successfully immobilized on the BP/PVA membrane via covalent bonding by using glutaraldehyde. The immobilization efficiency was optimized using response surface methodology (RSM) with the face-centered central composite design (FCCCD) model. The optimum enzyme immobilization efficiency was achieved at pH 6, with initial enzyme loading of 0.13 U/mL and immobilization time of 130 min. The results of BP/PVA membrane showed excellent performance in immobilization of JP with high enzyme loading of 217 mg/g and immobilization efficiency of 81.74%. The immobilized system exhibited significantly improved operational stability under various parameters, such as pH, temperature, thermal and storage stabilities when compared with free enzyme. The effective binding of peroxidase on the surface of the BP/PVA membrane was evaluated and confirmed by Field emission scanning electron microscopy (FESEM) coupled with Energy Dispersive X-Ray Spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). This work reports the characterization results and performances of the surface modified BP/PVA membrane for peroxidase immobilization. The superior properties of JP-immobilized BP/PVA membrane make it promising new-generation nanomaterials for industrial applications.
    Matched MeSH terms: Temperature
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