Two independent mol-ecules (A and B) comprise the asymmetric unit of the title compound, C21H18O4. There are significant conformational differences between the mol-ecules relating in particular to the relative orientation of the 3-oxo-2-(phenyl-methyl-idene)but-oxy substituent with respect to the superimposable chromen-2-one residues. To a first approximation, the substituents are mirror images; both are approximately perpendicular to the chromen-2-one fused ring system with dihedral angles of 88.50 (7) (A) and 81.96 (7)° (B). Another difference between the independent mol-ecules is noted in the dihedral angles between the adjacent phenyl and but-3-en-2-one groups of 8.72 (12) (A) and 27.70 (10)° (B). The conformation about the ethene bond in both mol-ecules is E. The crystal packing features C-H⋯O, C-H⋯π(ar-yl) and π-π [Cg⋯Cg = 3.6657 (8) and 3.7778 (8) Å] stacking inter-actions, which generate a three-dimensional network.
The present work covers the preparation of carbon-based nanosorbents by ethylene decomposition on stainless steel mesh without the use of external catalyst for the treatment of water containing nickel ions (Ni2+). The reaction temperature was varied from 650 to 850 degrees C, while reaction time and ethylene to nitrogen flow ratio were maintained at 30 min and 1:1 cm3/min, respectively. Results show that nanosorbents synthesised at a reaction temperature of 650 degrees C had the smallest average diameter (75 nm), largest BET surface area (68.95 m2/g) and least amount of impurity (0.98 wt.% Fe). A series of batch-sorption tests were performed to evaluate the effects of initial pH, initial metal concentration and contact time on Ni2+ removal by the nanosorbents. The equilibrium data fitted well to Freundlich isotherm. The kinetic data were best correlated to a pseudo second-order model indicating that the process was of chemisorption type. Further analysis by the Boyd kinetic model revealed that boundary layer diffusion was the controlling step. This primary study suggests that the prepared material with Freundlich constants compared well with those in the literature, is a promising sorbent for the sequestration of Ni2+ in aqueous solutions.
The environmental contamination by extremophile Aspergillus species, i.e., Aflatoxin B1, is hardly controllable in Southeast Asia and Sub-Saharan Africa, which lack handling resources and controlled storage facilities. Acute aflatoxicosis poisoning from aflatoxin-prone dietary staples could cause acute hepatic necrosis, acute liver failure, and death. Here, as the cheaper, more straightforward, and facile on-site diagnostic kit is needed, we report an ultraviolet-excitable optical aptasensor based on a fluorinated ethylene propylene film strip. Molecular dynamics on the aptamer.AFB1 complex revealed that the AFB1 to the aptamer increases the overall structural stability, suggesting that the aptamer design is suitable for the intended application. Under various influencing factors, the proposed label-free strategy offers a fast 20-min on-site fabrication simplicity and 19-day shelf-life. The one-pot incubation provides an alternative to catalytic detection and exhibited 4 times reusability. The recovery of crude brown sugar, processed peanuts, and long-grain rice were 102.74 ± 0.41 (n = 3), 86.90 ± 3.38 (n = 3), and 98.50 ± 0.42 (n = 3), comparable to High-Performance Liquid Chromatography-Photodiode Array Detector results. This study is novel owing to the peculiar UV-active spectrum fingerprint and the convenient use of hydrophobic film strips that could promote breakthrough innovations and new frontiers for on-site/forensic detection of environmental pollutants.
In many species floral senescence is coordinated by ethylene. Endogenous levels rise, and exogenous application accelerates senescence. Furthermore, floral senescence is often associated with increased reactive oxygen species, and is delayed by exogenously applied cytokinin. However, how these processes are linked remains largely unresolved. Erysimum linifolium (wallflower) provides an excellent model for understanding these interactions due to its easily staged flowers and close taxonomic relationship to Arabidopsis. This has facilitated microarray analysis of gene expression during petal senescence and provided gene markers for following the effects of treatments on different regulatory pathways.
Ultraviolet (UV) light especially UV-C has been used to sterilize fruits and vegetables. However, overdose of UV-C irradiation could cause brownish-red colouration to products such as banana fruit. Therefore, the objectives of this study were to: (1) examine the effect of UV-C irradiation at different doses on the surface colour of Berangan banana fruit during ripening; (2) determine polyphenol oxidase (PPO) activity after irradiated with different doses of UV-C, and (3) examine the effectiveness of three browning assessment methods (subjective score, browning index derived from Lab colour space and optical density of 420 nm) in response to PPO activity of UV-C irradiated Berangan banana fruit. Mature green Berangan banana fruit were irradiated with 0, 0.01, 0.02, 0.03 and 0.04 kJ/m2 UV-C. After irradiation, the fruit were initiated to ripening using 1 mL/L ethylene for 24 h. Then, the fruit were allowed to ripen in 27oC and fruit of day 0, 1, 3 and 5 were sampled for peel colour (L*, a*, b*, C* and ho), browning assessment (three methods) and PPO assay. The peel colour, browning assessment using subjective score and optical density, and PPO activity of Berangan banana fruit were affected significantly (P ≤ 0.05) by interaction of radiation dose x ripening day. The values of L*, b*, C* and ho decrease while a* values increase as fruit irradiated with 0.03 and 0.04 kJ/m2 UV-C indicating brownish-red has occurred. Fruit irradiated with 0.04 kJ/m2 UV-C discoloured by ripening day 3 while those irradiated with 0.03 kJ/m2 discolored by day 5. Similar result was obtained when fruit assessed for its browning using subjective score and optical density. A contrary result was obtained in PPO activity where UV-C irradiation has inhibited Berangan banana fruit PPO activity by ripening day 5. Correlation analysis showed that browning index that derived from colour space is highly related to PPO activity with coefficients of 0.93. As conclusion, the lethal dose causing browning for Berangan banana fruit is 0.03 kJ/m2 and browning index that derived from colour space is most effective to correlate browning with PPO activity.
Effects of organoclay concentration on the properties of radiation crosslinked natural rubber (NR)/ ethylene vinyl acetate (EVA)/clay nanocomposites were investigated. The NR/EVA blend with a ratio of 40/60 was melt blended with different concentration of either dodecyl ammonium montmorillonite (DDA-MMT) or dimethyl dihydrogenated tallow quarternary ammonium montmorillonite (C20A). Composite of NR/EVA blend with unmodified clay (Na-MMT) was also prepared for comparison purposes. The composites were irradiated with electron beam (EB) at an optimum irradiation dose. The formation of radiation-induced crosslinking depends on the type and concentration of the organoclay used in the preparation of nanocomposites as measured by gel content. Changes in the interlayer distance of the silicate layers with the increase of organoclay concentration were shown by the XRD results. Variation in the tensile properties of the nanocomposites with the increase of organoclay concentration depends on the formation of crosslinking as well as reinforcement effect of the organoclay. Improvement in thermal stability of the NR/EVA blend was also observed with the presence of organoclay.
A chemical modifier (acrylic acid) was used to improve the thermal properties of polypropylene/ ethylene propylene diene terpolymer/calcium carbonate (PP/EPDM/CaCO3) composites. Treated
and untreated PP/EPDM composites were filled by CaCO3 at 0, 20 and 40% wt. The composites
were prepared using Z-blade mixer machine at 180oC and 50 rpm of rotor speed. Thermogravimetric
analysis (TGA) and differential scanning calorimetry (DSC) methods were used to analyze the thermal properties of the composites. Thermogravimetric analysis indicated that the total weight loss of PP/EPDM/CaCO3 composites decreased with the increasing filler loading for the treated and untreated composites. Meanwhile, the presence of acrylic acid was found to have increased the thermal stability and crystallinity of PP/EPDM/CaCO3
.
A good temperature management, such as precooling and cold storage, can delay deterioration of fresh produce. In this study, different forced-air precooling times were applied on Musa AAA Berangan to investigate the influence of forced-air precooling time on the changes of quality attributes and consumer acceptance. The banana was subjected to forced-air precooling treatment (5 ± 1°C) for 0, 14, 50, and 120 min and then stored in a cold room (13 ± 1°C) for 2 weeks. Then, all the fruits were transferred to a ripening room (25 ± 2°C) and initiated to ripen with ethylene gas. Quality attributes analyses and sensory evaluations were conducted when the fruits reached maturity index 5. Quality parameters, such as soluble solids concentration, titratable acidity, pulp firmness, and peel colour, showed no significant differences when fruits were precooled at different times. Blackening of peel as a result of chilling injury occurred in fruits treated with forced-air precooling for 50 and 120 min. This blackening significantly influenced consumer acceptance, although it did not affect the pulp colour and taste.
In this study, compatibilizing effects of caprolactam-maleic anhydride (CL-MAH) and
polyethylene-grafted-maleic anhydride (PE-g-MAH) with different blend compositions on polymer
blends of recycled high density polyethylene (RHDPE) and ethylene vinyl acetate (EVA) blends were
investigated by tensile properties and swelling behavior. The use of CL-MAH improved the
compatibility of RHDPE80/EVA20 blend composition, and tensile properties of the resultant blend
compared well with those of RHDPE/EVA blends. Addition of PE-g-MAH improved the tensile
properties of RHDPE/EVA/PE-g-MAH blends than RHDPE/EVA blends without compatibilizer. The
scanning electron microscopy (SEM) morphologies of fracture surface for RHDPE/EVA blends with
presence of compatibilizers showing better incorporation of two different phases of polymer matrix.
The novelty of this work is the conjugation of poly(ethylene) oxide (PEO) with the erbium oxide (Er2O3) nanoparticles using the electrospinning technique. In this work, synthesised PEO-coated Er2O3 nanofibres were characterised and evaluated for their cytotoxicity to assess their potential use as diagnostic nanofibres for magnetic resonance imaging (MRI). PEO has significantly impacted nanoparticle conductivity due to its lower ionic conductivity at room temperature. The findings showed that the surface roughness was improved over the nanofiller loading, implying an improvement in cell attachment. The release profile performed for drug-controlling purposes has demonstrated a stable release after 30 min. Cellular response in MCF-7 cells showed high biocompatibility of the synthesised nanofibres. The cytotoxicity assay results showed that the diagnostic nanofibres had excellent biocompatibility, indicating the feasibility for diagnosis purposes. With excellent contrast performance, the PEO-coated Er2O3 nanofibres developed novel T2 and T1-T2 dual-mode MRI diagnostic nanofibres leading to better cancer diagnosis. In conclusion, this work has demonstrated that the conjugation of PEO-coated Er2O3 nanofibres improved the surface modification of the Er2O3 nanoparticles as a potential diagnostic agent. Using PEO in this study as a carrier or polymer matrix significantly influenced the biocompatibility and internalisation efficiency of the Er2O3 nanoparticles without triggering any morphological changes after treatment. This work has suggested permissible concentrations of PEO-coated Er2O3 nanofibres for diagnostic uses.
Embolisation has long been used as an adjunct to surgical resection in the treatment of brain arteriovenous malformation (bAVM). The most commonly used embolic material, n-butylcyanoacrylate glue, requires experience and skill to handle its quick and unpredictable flow and polymerisation. A new liquid embolic agent, ethylene vinyl alcohol copolymer (Onyx), is less adhesive and polymerises slowly, which provides better control for radiologists performing embolisation.
The effect of electron beam radiation on ethylene-propylene diene terpolymer/polypropylene blends is studied as an attempt to develop radiation sterilizable polypropylene/ethylene-propylene diene terpolymer blends suitable for medical devices. The polypropylene/ethylene-propylene diene terpolymer blends with mixing ratios of 80/20, 50/50, 20/80 were prepared in an internal mixer at 165°C and a rotor speed of 50 rpm/min followed by compression molding. The blends and the individual components were radiated using 3.0 MeV electron beam accelerator at doses ranging from 0 to 100 kGy in air and room temperature. All the samples were tested for tensile strength, elongation at break, hardness, impact strength, and morphological properties. After exposing to 25 and 100 kGy radiation doses, 50% PP blend was selected for in vivo studies. Results revealed that radiation-induced crosslinking is dominating in EPDM dominant blends, while radiation-induced degradation is prevailing in PP dominant blends. The 20% PP blend was found to be most compatible for 20-60 kGy radiation sterilization. The retention in impact strength with enhanced tensile strength of 20% PP blend at 20-60 kGy believed to be associated with increased compatibility between PP and EPDM along with the radiation-induced crosslinking. The scanning electron micrographs of the fracture surfaces of the PP/EPDM blends showed evidences consistent with the above contentation. The in vivo studies provide an instinct that the radiated blends are safe to be used for healthcare devices.
Adhesion of the barley husk to the underlying caryopsis requires the development of a cuticular cementing layer on the caryopsis surface. Differences in adhesion quality among genotypes have previously been correlated with cementing layer composition, which is thought to influence caryopsis cuticle permeability, the hypothesised mechanism of adhesion mediation. It is not yet known whether differences in adhesion quality among genotypes are determined by changes in caryopsis cuticle permeability. We examined changes in candidate cementing layer biosynthetic and regulatory genes to investigate the genetic mechanisms behind husk adhesion quality. We used both commercially relevant UK malting cultivars and older European lines to ensure phenotypic diversity in adhesion quality. An ethylene responsive transcription factor (NUD) is required for the development of the cementing layer. To examine correlations between gene expression, cementing layer permeability and husk adhesion quality we also treated cultivars with ethephon (2-chloroethylphosphonic acid) which breaks down to ethylene, and silver thiosulphate which inhibits ethylene reception, and measured caryopsis cuticle permeability. Differential adhesion qualities among genotypes are not determined by NUD expression during development of the cementing material alone, but could result from differences in biosynthetic gene expression during cementing layer development in response to longer-term NUD expression patterns. Altered caryopsis cuticle permeability does result in altered adhesion quality, but the correlation is not consistently positive or negative. Cuticle permeability is therefore not the mechanism that determines husk adhesion quality, but is likely a consequence of the required cuticular compositional changes that determine adhesion.
Mango as a climacteric fruit is known to have increased auxins with concomitant increased ethylene and carbon dioxide production during ripening. Such hormonal properties alongside many other nutritional benefits prepared in the form of compost extract were tested for enhancing production of medicinal bitter gourd of Momordica charantia. This cucurbit was planted on field beds at 0.8 x 0.5 m followed by application of compost extract prepared with anaerobic decomposition of rotting mango fruits, fish wastes of gills and internal organs and brown sugar at different ratios in plastic containers. The results obtained showed that mango:fish wastes:sugar compost extract of 2:1:1 applied to soil around the root collar at 10 ml at fortnight intervals allowed the plants to gain the highest mean number of fruits per plant of 18.3, mean individual fruit weight of 25.95 g or mean yield of 11.80 tonnes per hectare. Mango compost extract is, hence, beneficial in organic production of this medicinal bitter gourd.
Carbonized natural filler can offer the production of low cost composites with an eco-friendliness value. The evolving field of electronics encourages the exploration of more functions and potential for carbonized natural filler, such as by modifying its surface chemistry. In this work, we have performed surface modification on carbonized wood fiber (CWF) prior to it being used as filler in the ethylene vinyl acetate (EVA) composite system. Zinc chloride (ZnCl2) with various contents (2 to 8 wt%) was used to surface modify the CWF and the effects of ZnCl2 composition on the surface morphology and chemistry of the CWF filler were investigated. Furthermore, the absorptive, mechanical, thermal, and electrical properties of the EVA composites containing CWF-ZnCl2 were also analyzed. SEM images indicated changes in the morphology of the CWF while FTIR analysis proved the presence of ZnCl2 functional groups in the CWF. EVA composites incorporating the CWF-ZnCl2 showed superior mechanical, thermal and electrical properties compared to the ones containing the CWF. The optimum content of ZnCl2 was found to be 6 wt%. Surface modification raised the electrical conductivity of the EVA/CWF composite through the development of conductive deposits in the porous structure of the CWF as a channel for ionic and electronic transfer between the CWF and EVA matrix.
Cantaloupes continue to ripen after harvesting which is caused by ethylene production due to climacteric behaviour during postharvest storage. In this study, the cantaloupe fruits harvested at commercial maturity were evaluated for quality attributes during three weeks of storage at 10°C and a relative humidity (RH) of 90±5%. In addition, fresh-cut samples were stored for a further 19 days at 2°C and 87% RH. The fresh-cut samples were prepared on a weekly basis by dipping into deionised water (control) at 2°C for 1 minute. The effect of postharvest storage of cantaloupe on the physico-chemical properties and microbial activity was observed prior to fresh-cut processing. It was found that firmness, luminosity (L*), and titratable acidity (TA) decreased, while total soluble solids (TSS), pH, TSS:TA ratio, microbial activity (total plate count (TPC) and yeast and mould (YM)) of the fresh-cut increased over the postharvest storage period of the fruit. Meanwhile, the orange colour and the intensity (hue angle, hab, and chromaticity) of the flesh did not differ significantly during storage. The cantaloupe stored for three weeks at a low temperature indicated a successful potential for fresh-cut processing due to good maintenance of the product quality.
In this research work, graphene nanoplatelets (GNP) were selected as alternative reinforcing nanofillers to enhance the properties of polypropylene (PP) using different compatibilizers called polypropylene grafted maleic anhydride (PP-g-MA) and ethylene-octene elastomer grafted maleic anhydride (POE-g-MA). A twin screw extruder was used to compound PP, GNP, and either the PP-g-MA or POE-g-MA compatibilizer. The effect of GNP loading on mechanical and thermal properties of neat PP was investigated. Furthermore, the influence and performance of different compatibilizers on the final properties, such as mechanical and thermal, were discussed and reported. Tensile, flexural, impact, melting temperature, crystallization temperature, and thermal stability were evaluated by using a universal testing system, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). For mechanical properties, it was found that increasing GNP content from 1 wt.% to 5 wt.% increased tensile strength of the neat PP up to 4 MPa. The influence of compatibilizers on the mechanical properties had been discussed and reported. For instance, the addition of PP-g-MA compatibilizer improved tensile strength of neat PP with GNP loading. However, the addition of compatibilizer POE-g-MA slightly decreased the tensile strength of neat PP. A similar trend of behavior was observed for flexural strength. For thermal properties, it was found that both GNP loading and compatibilizers have no significant influence on both crystallization and melting temperature of neat PP. For thermal stability, however, it was found that increasing the GNP loading had a significant influence on improving the thermal behavior of neat PP. Furthermore, the addition of compatibilizers into the PP/GNP nanocomposite had slightly improved the thermal stability of neat PP.
Polymeric materials such as polypropylene (PP), polyethylene (PE) and ethylene propylene diene monomer (EPDM) are widely used as insulators for cable applications. We investigated the effect of alumina trihydrate (ATH) loading on the mechanical properties of PP/EPDM blend. Preliminary study showed that PP/EPDM (60:40) was the optimum composition. ATH filled PP/EPDM composites was prepared by using twin screw extruder. In this study, the tensile properties and hardness of the composites were evaluated. The tensile modulus and hardness increased while elongation at break and tensile strength decreased with increasing ATH content. Scanning electron microscope was used to study the morphology of ATH in PP/EPDM blend.
Postconsumer polyethylene terephthalate (PET) has potential applications in many areas of manufacturing, but contamination by hazardous polyvinyl chloride (PVC) in common waste streams can reduce its recyclable value. Separating collected PET-PVC mixtures before recycling remains very challenging because of the similar physicochemical properties of PET and PVC. Herein, we describe a novel flotation process with corona modification pretreatment to facilitate the separation of PET-PVC mixtures. Through water contact angle, surface free energy, X-ray photoelectron and FT-IR characterization, we found that polar hydroxyl groups can be more easily introduced on the PVC surface than on the PET surface induced by corona modification. This selective wetting can suppress the floatability of PVC, leading to the separation of PET as floating product. A reliable mechanism including two different hydrogen-abstraction pathways was established. Response surface methodology consisting of Plackett-Burman and Box-Behnken designs was adopted for optimization of the combined process, and control parameters were solved based on high-quality prediction models, with fitting from significant variables and interactions. For physical or chemical circulation strategies with PET purity prioritization, the validated purity of the product reached 96.05% at a 626 W corona power, 5.42 m/min passing speed, 24.78 mg/L frother concentration and 286 L/h air flow rate. For the energy recuperation strategy with PET recovery prioritization, the factual recovery reached 98.08% under a 601 W corona power, 6.04 m/min passing speed, 27.55 mg/L frother concentration and 184 L/h air flow rate. The current work provides technological insights into the cleaner disposal of waste plastics.
Biocompatible polymers have received significant interest from researchers for their potential in diagnostic applications. This type of polymer can perform with an appropriate host response or carrier for a specific purpose. The current study aims to fabricate and characterise poly(ethylene) oxide (PEO) nanofibres with different concentrations for cytotoxicity evaluation in human breast cancer cell lines (MCF-7) and to get an optimal PEO nanofibre concentration (permissible limit) as a suitable polymer matrix or carrier with potential use in diagnostic applications. The fabrication of PEO nanofibres was done using electrospinning and was characterised by structure and morphology, surface roughness, chemical bonding and release profiles. The functional effects of PEO nanofibres were evaluated with MTS assay and colony formation assay in MCF-7 cells. The results showed that viscosity plays a vital role in synthesising a polymer solution in electrospinning for producing beadless nanofibrous mats ranging from 4.7 Pa·s to 77.7 Pa·s. As the PEO concentration increases, the nanofibre diameter and thickness will increase, but the surface roughness will be decreased. The average fibre diameter for 5 wt% PEO, 6 wt% PEO and 7 wt% PEO nanofibres were 129 ± 70 nm, 185 ± 55 nm and 192 ± 53 nm, respectively. In addition, the fibre thickness for 4 wt% PEO, 5 wt% PEO, 6 wt% PEO and 7 wt% PEO nanofibres were 269 ± 3 μm, 664 ± 4 μm, 758 ± 7 μm and 1329 ± 44 μm, respectively. Contrarily, the surface roughness for 4 wt% PEO, 5 wt% PEO, 6 wt% PEO and 7 wt% PEO nanofibres were 55.6 ± 9 nm, 42.8 ± 6 nm, 42.7 ± 7 nm and 36.6 ± 1 nm, respectively. PEO nanofibres showed the same burst release pattern and rate due to the same molecular weight of PEO with a stable release rate profile after 15 min. It also demonstrates that the percentage of PEO nanofibre release increased with the increasing PEO concentration due to the fibre diameter and thickness. The findings showed that all PEO nanofibres formulations were non-toxic to MCF-7 cells. It is suggested that 5 wt% PEO nanofibre exhibited non-cytotoxic characteristics by maintaining the cell viability from dose 0-1000 μg/ml and did not induce the number of colonies. Therefore, 5 wt% PEO nanofibre is the optimal nanofibre concentration and was suggested as a suitable base polymer matrix or carrier with potential use for diagnostic purposes. The findings in this study have demonstrated the influence of cell growth and viability, including the effects of PEO nanofibre formulations on cancer progress characteristics to achieve a permissible PEO nanofibre concentration limit that can be a benchmark in medical applications, particularly diagnostic applications.