279 research outputs found
Volatile organic compound analysis as advanced technology to detect seed quality in groundnut
An experiment was conducted to profiling the volatile organic compounds emitted from groundnut seeds during storage and also to assess the volatiles emission level during seed deterioration. Volatile organic compounds profiling of stored groundnut seeds was done through GC-MS at monthly intervals. The results showed that several volatile compounds were released from stored groundnut seeds and all the compounds are falling into eight major groups viz., alcohols, aldehydes, acids, esters, alkanes, alkenes, ketones and ethers. The study clearly demonstrated the influence of volatile organic compounds emission level on physiological and biochemical properties during storage. There was a significant decrease in physiological and biochemical quality attributes noted due to an increase in the strength of volatiles released during ageing. When the release of total volatile strength reached more than 50%, a significant reduction in physiological attributes such as germination, root and shoot length, dry matter production and vigour index were observed. With respect to biochemical properties, a significant increase in electrical conductivity of seed leachate, lipid peroxidation and lipoxygenase activity, and a decrease in dehydrogenase, catalase and peroxidase activities were observed. However, the highest reduction in all these properties was recorded when the total volatile strength reached 92.72%. The study concluded that the volatiles released during seed deterioration could be considered the signature components for detecting the seed quality during storage
Materials selection analysis for vibration isolator pads
Isolator pads which also called as vibration pads are used in many applications to isolate vibration, extend machine life, reduce maintenance costs and reduce excessive wear. It is the process of isolating objects such as equipment from harmful vibration sources. In this study, two types of isolator pad materials; neoprene and sorbothone were analyzed in order to be used for stackable washing and dryer machine. In this case, the stackable washing and dryer machine together with the isolator pads were simplified into two degree of freedom system, where the first and the second natural frequencies for each material of isolator pad were determined by using matrix iteration method, in which later were validated by a modern tool such as Matlab. For neoprene material, the first natural frequency obtained was 44.2 rad/s and the second natural frequency is 107.7 rad/s. By contrast, sorbothone material shows slightly higher for both first and second natural frequencies compared to neoprene, which were 57.9 rad/s and 141.0 rad/s respectively. From this result, it shows that neoprene is suitable to be used as the coupling (spring) material since it has lower natural frequency value compared to sorbothone, besides the second natural frequency of sorbothone material is near to the forcing frequency 140 rad/s, thus could amplified the vibration due to resonance
Assessment of rice (Co 51) seed ageing through volatile organic compound analysis using Headspace-Solid Phase Micro Extraction/ Gas Chromatography-Mass Spectrometry (HS-SPME/GCMS)
Seed ageing is an inevitable process that reduces seed quality during storage. When seeds deteriorate as a result of the lipid peroxidation process, it leads to produce toxic volatile organic compounds. These volatiles served as an indicator for the viability of stored seeds. With this background, the study was conducted to profile the volatile organic compounds emitted from rice seeds during storage. Volatile profiling of stored rice var. Co 51 seeds was done through Headspace-Solid phase microextraction/ Gas chromatography-mass spectrometry (HS-SPME/GCMS). The study clearly demonstrated that the significant decrease in physiological and biochemical quality attributes was noted due to an increase in the strength of volatiles released during ageing. When the release of total volatile strength reached more than 40%, a significant reduction in physiological attributes such as germination, root and shoot length, dry matter production and vigour index were observed. With respect to biochemical properties, a significant increase in electrical conductivity of seed leachate, lipid peroxidation and lipoxygenase activity, and decrease in dehydrogenase, catalase and peroxidase activities were observed. However, the highest reduction in all these properties were recorded when the total volatile strength reached to 54.90%. Finally, the study concluded that, among all the volatiles, 1-hexanol, 1-butanol, ethanol, hexanal, acetic acid, hexanoic acid and methyl ester were the most closely associated volatiles with seed deterioration. It indicates that these components could be considered the signature components for assessing the seed quality in rice during storage.
Bread packaging techniques and trends
Bread staling and microbial growth is a complex physiochemical change that occurs during bread storage mainly reducing the quality and consumer acceptance. It is significant to understand the causes of physical, chemical, and microbial spoilage of bakery products in the food industry, to prevent quality decay and economic loss for manufacturers and consumers. Traditional packaging has limitations in protecting and preserving the final products’ safety, hygiene, and quality. Effective novel strategies must be included in food packaging, especially to minimize the organoleptic losses of baked foods during their shelf life. Furthermore, owing to the spread of foodborne diseases, which directly affect the safety of the products, customer demand is increasing significantly to reduce the use of synthetic preservatives instead of natural ones. Innovative packaging is altering the way food items are packed in several ways to extend and monitor product shelf life. Traditional packaging includes packaging food in synthetic polymer film; however, modern technology allows them to interact with active/functional substances. This paper discusses innovative bread packaging strategies such as modified atmosphere packaging (MAP), active packaging (AP), intelligent packaging (IP), biosensor, and nano packaging. Furthermore, MAP and AP have received greater attention in this study due to their considerable effect in prolonging the shelf life of bread and naturally preventing fungal activity, and have gained a lot of interest among producers and consumers in recent years
Ultrasonic-assisted synthesis of graphene oxide – fungal hyphae: An efficient and reclaimable adsorbent for chromium(VI) removal from aqueous solution
In this study, a hybrid film bio-nanocomposite material was developed based on the graphene oxide/fungal hyphae (GO-FH) interaction. The developed GO-FH bio-nanocomposite material was used for the removal of hexavalent chromium from aqueous solution. The GO-FH bio-nanocomposite material was prepared by ultrasonic irradiation technique. The synthesized GO-FH bio-nanocomposite material was characterized by XRD, FT-IR, SEM, TEM and TGA. The adsorption experiments were carried out in batch mode to optimize parameters such as pH, adsorbent dosage, initial Cr(VI) ion concentration, contact time and shaking speed. The results indicated that the adsorption of Cr(VI) onto GO-FH bio-nanocomposite material was pH dependant, with the maximum adsorption capacity of 212.76 mg/g occurred at pH 2.0. The adsorption studies followed, Langmuir isotherm and pseudo second order kinetic model. Findings demonstrates that GO-FH bio-nanocomposite material exhibited excellent regeneration performance
Crush characteristics and energy absorption of thin-walled tubes with through-hole crush initiators
An experimental investigation was conducted to compare the crush characteristics and
energy absorption capacity of circular and square tubes with located through-hole crush initiator.
Circular through-holes were fabricated at three different configurations based on location into steel
tubes which had a length of 200 mm. Furthermore, two different side configurations along the tube
were considered for introducing the crush initiators. The results found that adding crush initiator
onto the tubes effectively reduced the initial peak force of a thin-walled circular and square tubes
under axial quasi-static loading. The peak crush force was reduced within a range 3-10% and 5-16%
for circular and square tubes, respectively when compared with corresponding tubes without crush
initiator. Moreover, the energy absorption capacity of the tubes was independent with the
incorporation of through-hole crush initiators. However, the energy absorption of circular and
square tubes slightly decreases when compared with the tubes fabricated four sided crush initiation
and tubes without crush initiator. Overall, the effect of location and number of crush initiation
significantly influenced the initial peak forces while maintain the energy absorbed
Energy absorption characteristics of polyurethane composite foam filled tubes subjected to quasi-static axial loading
Foam-filled enclosures are very common in structural crashworthiness to increase energy
absorption. However, very less research has been targeted on potential use of natural/recycled
material reinforced foam-filled tubes. Therefore, an experimental investigation was performed to
quantify energy absorption capacity of polyurethane (PU) composite foam-filled circular steel tubes
under quasi-static axial loading. The thickness of the tubes was varied from 1.9, 2.9 and 3.6 mm.
The tubes were filled with PU composite foam. The PU composite foam was processed with
addition of kenaf plant fiber and recycled rubber particles that were refined at 80 mesh particulates
into PU system. The density of PU resin was varied from 100, 200 and 300 kgm-3
. The PU
composite foam-filled tubes were crushed axially at constant speed in a universal testing machine
and their energy absorption was characterized from the resulting load-deflection data. Results
indicate that PU composite foam-filled tubes exhibited better energy absorption capacity than those
PU foam-filled tubes and its respective empty tubes. Interaction effect between the tube and the
foam and incorporation of filler into PU system led to an increase in mean crushing load compared
to that of the unfilled PU foam or tube itself. Relatively, progressively collapse modes were
observed for all tested tubes. Findings suggested that composite foam-filled tubes could be used as
crashworthy member
Phase Transitions and Their Interaction with Dislocations in Silicon
In this paper, phase transformations (PTs) in silicon were investigated through molecular dynamics (MD) using Tersoff potential. In the first step, simulations of PTs in single crystal silicon under various stress-controlled loading were carried out. Results shows that all instability points under various stress states are described by criteria, which are linear in the space of normal stresses. There is a region in the stress space in which conditions for direct and reverse PTs coincide and a unique homogeneous phase transition (without nucleation) can be realized. Finally, phase transition in bi-crystalline silicon with a dislocation pileup along the grain boundary (GB) was carried out. Results showed that the phase transition pressure first decreases linearly with the number of dislocation pileups and then reaches a plateau with the accumulation of dislocations in the pileup. The maximum reduction of phase transition pressure is 30% compared to that for perfect single crystalline silicon
The CXCR4-LASP1-eIF4F Axis Promotes Translation of Oncogenic Proteins in Triple-Negative Breast Cancer Cells
Triple-negative breast cancer (TNBC) remains clinically challenging as effective targeted therapies are lacking. In addition, patient mortality mainly results from the metastasized lesions. CXCR4 has been identified to be one of the major chemokine receptors involved in breast cancer metastasis. Previously, our lab had identified LIM and SH3 Protein 1 (LASP1) to be a key mediator in CXCR4-driven invasion. To further investigate the role of LASP1 in this process, a proteomic screen was employed and identified a novel protein-protein interaction between LASP1 and components of eukaryotic initiation 4F complex (eIF4F). We hypothesized that activation of the CXCR4-LASP1-eIF4F axis may contribute to the preferential translation of oncogenic mRNAs leading to breast cancer progression and metastasis. To test this hypothesis, we first confirmed that the gene expression of CXCR4, LASP1, and eIF4A are upregulated in invasive breast cancer. Moreover, we demonstrate that LASP1 associated with eIF4A in a CXCL12-dependent manner via a proximity ligation assay. We then confirmed this finding, and the association of LASP1 with eIF4B via co-immunoprecipitation assays. Furthermore, we show that LASP1 can interact with eIF4A and eIF4B through a GST-pulldown approach. Activation of CXCR4 signaling increased the translation of oncoproteins downstream of eIF4A. Interestingly, genetic silencing of LASP1 interrupted the ability of eIF4A to translate oncogenic mRNAs into oncoproteins. This impaired ability of eIF4A was confirmed by a previously established 5′UTR luciferase reporter assay. Finally, lack of LASP1 sensitizes 231S cells to pharmacological inhibition of eIF4A by Rocaglamide A as evident through BIRC5 expression. Overall, our work identified the CXCR4-LASP1 axis to be a novel mediator in oncogenic protein translation. Thus, our axis of study represents a potential target for future TNBC therapies
Purification and preliminary characterization of a xylanase from Thermomyces lanuginosus strain SS-8
Thermomyces lanuginosus SS-8 was isolated from soil samples that had been collected from near self-heating plant material and its extracellular cellulase-free xylanase purified approximately 160-fold using ion exchange chromatography and continuous elution electrophoresis. This xylanase was thermoactive (optimum temperature 60 °C) at pH 6.0 and had a molecular weight of 23.79 kDa as indicated by SDS-PAGE electrophoresis. The xylanase rapidly hydrolyzed xylan directly to xylose without the production of intermediary xylo-oligosaccharides within 15 min of incubation under optimum conditions. This trait of rapidly degrading xylan to xylose as a sole end-product could have biotechnological potential in degradation of agro-wastes for bioethanol manufacturing industry
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