| 1. |
- Ahmed, Naeem, et al.
(författare)
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A study to examine the ageing behaviour of cold plasma-treated agricultural seeds
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Cold plasma (low pressure) technology has been effectively used to boost the germination and growth of various crops in recent decades. The durability of these plasma-treated seeds is essential because of the need to store and distribute the seeds at different locations. However, these ageing effects are often not ascertained and reported because germination and related tests are carried out within a short time after the plasma-treatment. This research aims to fill that knowledge gap by subjecting three different types of seeds (and precursors): Bambara groundnuts (water), chilli (oxygen), and papaya (oxygen) to cold plasma-treatment. Common mechanisms found for these diverse seed types and treatment conditions were the physical and chemical changes induced by the physical etching and the cold plasma on the seeds and subsequent oxidation, which promoted germination and growth. The high glass transition temperature of the lignin-cellulose prevented any physical restructuring of the surfaces while maintaining the chemical changes to continue to promote the seeds germination and growth. These changes were monitored over 60 days of ageing using water contact angle (WCA), water uptake, electrical conductivity, field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The vacuum effect was also investigated to separate its effect from cold plasma (low pressure). This finding offers a framework for determining how long agricultural seeds that have received plasma treatment can be used. Additionally, there is a need to transfer this research from the lab to the field. Once the impact of plasma treatment on seeds has been estimated, it will be simple to do so.
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| 2. |
- Ahmed, Naeem, et al.
(författare)
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Effects of Oxygen (O2) Plasma Treatment in Promoting the Germination and Growth of Chili
- 2022
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Ingår i: Plasma chemistry and plasma processing. - : Springer. - 0272-4324 .- 1572-8986. ; 42:1, s. 91-108
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Tidskriftsartikel (refereegranskat)abstract
- In general, seed germination is improved by low-pressure plasma treatment using precursors such as air, nitrogen, O2, and argon, etc. For the first time, low-pressure O2 plasma was used to treat chili seeds in this study. When compared to untreated and vacuum-treated seeds, O2 plasma treatment using the discharge power of 80 W for 60 s significantly improves chili seed germination and growth. The effect of vacuum on the germination and growth of chili seeds was also studied and shown to be negligible. The physical and chemical changes induced by O2 plasma treatment were investigated to understand the plasma treatment to germination improvement. Combinatory etching and chemical modification aided imbibition and increased germination percentage in this O2 plasma treatment on chili seeds. The success of this method has the potential to be scaled up to solve food security issues with seeds that would otherwise struggle to germinate.
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| 3. |
- Ahmed, Naeem, et al.
(författare)
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Germination and growth improvement of papaya utilizing oxygen (O2) plasma treatment
- 2022
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Ingår i: Journal of Physics D. - : Institute of Physics (IOP). - 0022-3727 .- 1361-6463. ; 55:25
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Tidskriftsartikel (refereegranskat)abstract
- In general, cold plasma treatment improves crop germination and growth. The purpose of this research is to examine the impact of low-pressure O2 plasma treatment on the germination and growth kinetics of papaya seeds. Seeds were treated for 40 s at a discharge power of 80 W using O2 as a monomer. Physical and chemical changes were studied to understand the mechanism of germination and growth improvement. Furthermore, changes in phytohormones and antioxidant activity that were beneficial to germination were also examined. O2 plasma treatment improved wettability, surface etching, and oxidation, and affected other molecular-level changes leading to a 16% germination improvement in papaya.
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| 4. |
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| 5. |
- Masood, Asad, et al.
(författare)
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Atmospheric Pressure Plasma Polymerisation of D-Limonene and Its Antimicrobial Activity
- 2023
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Ingår i: Polymers. - : MDPI. - 2073-4360. ; 15:2
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Tidskriftsartikel (refereegranskat)abstract
- Antibacterial coating is necessary to prevent biofilm-forming bacteria from colonising medical tools causing infection and sepsis in patients. The recent coating strategies such as immobilisation of antimicrobial materials and low-pressure plasma polymerisation may require multiple processing steps involving a high-vacuum system and time-consuming process. Some of those have limited efficacy and durability. Here, we report a rapid and one-step atmospheric pressure plasma polymerisation (APPP) of D-limonene to produce nano-thin films with hydrophobic-like properties for antibacterial applications. The influence of plasma polymerisation time on the thickness, surface characteristic, and chemical composition of the plasma-polymerised films was systematically investigated. Results showed that the nano-thin films deposited at 1 min on glass substrate are optically transparent and homogenous, with a thickness of 44.3 ± 4.8 nm, a smooth surface with an average roughness of 0.23 ± 0.02 nm. For its antimicrobial activity, the biofilm assay evaluation revealed a significant 94% decrease in the number of Escherichia coli (E. coli) compared to the control sample. More importantly, the resultant nano-thin films exhibited a potent bactericidal effect that can distort and rupture the membrane of the treated bacteria. These findings provide important insights into the development of bacteria-resistant and biocompatible coatings on the arbitrary substrate in a straightforward and cost-effective route at atmospheric pressure.
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| 6. |
- Masood, Asad, et al.
(författare)
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Atmospheric Pressure Plasma Polymerization of Carvone: A Promising Approach for Antimicrobial Coatings
- 2023
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Ingår i: Coatings. - : Mdpi. - 2079-6412. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- Medical devices are often vulnerable to colonization by nosocomial pathogens (bacteria), leading to infections. Traditional sterilization methods may not always be effective, and as a result, alternative options are being explored to prevent microbial contamination. Recently, scientists are emphasizing using plant-derived essential oils that possess inherent antibacterial properties to produce antimicrobial coatings using plasma polymerization technology carried out at atmospheric pressure (AP). This approach shows promise compared to other coating strategies that need several processing steps, including a high-vacuum system, and are laborious, such as the immobilization of antimicrobial materials on precoated layers in the low-pressure plasma polymerization approach. The present study demonstrates the potential of AP plasma polymerization for producing thin films with excellent antibacterial properties and surface characteristics. The resulting coatings are stable, smooth, and have high wettability, making them ideal for repelling bacteria. The calculated zeta potential and deposition rate for the films are also favorable. These AP plasma-polymerized thin films created from carvone show a reduction rate of more than 90% for Escherichia coli and Staphylococcus aureus bacteria. Our computational docking studies also reveal strong binding interactions between the original carvone monomer and both bacteria. The study suggests that these AP plasma-produced coatings have great potential as antibacterial coatings for biomedical devices.
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