ABSTRACT Protein energy malnutrition (PEM), a condition influenced by a complex interplay of biological and environmental factors, gut microbiota and low consumption of calories or protein, remains a serious global public health concern, especially in developing nations. Technologies based on cold atmospheric plasma (CAP), a mildly ionized gas rich in biochemically reactive species, have already demonstrated their strong potential as a simple, flexible and sustainable solution to many global challenges, from disease management to environmental remediation and food sustainability. This article explores the innovative strategies by which CAP technologies can address and mitigate PEM. Controlled preclinical studies indicate that CAP technologies can positively contribute to food security by enhancing protein availability and quality. By affecting oral and gut microbiota, CAP enhanced protein absorption. It can also modify the chemical structure of various food proteins to maximize their nutrient content and reduce allergenicity. This review addresses possible solutions using CAP in the mitigation of PEM and outlines key challenges and opportunities in translating CAP technologies into real‐life solutions, particularly in regions where the burden of PEM is most significant.

The effect on the photovoltaic properties of the TiO2-based cadmium sulfide (CdS) quantum dot sensitized solar cells (QDSSCs) was investigated by incorporating carbon quantum dots (CQDs) synthesized via a cold atmospheric plasma method. CQD incorporated photoanodes were characterized by SEM, TEM, XRD, Raman spectroscopy, FTIR spectroscopy, PL spectroscopy, UV-visible spectroscopy, and Mott-Schottky techniques. TEM measurements revealed that the CQDs were mostly spherical with an average diameter of similar to 3 nm. The presence of CQDs in the TiO2 photoanode was confirmed by both Raman spectroscopy and FTIR measurements. The findings from the PL and IPCE analyses showed that CQDs functioned as an energy down-converting material, broadening the responsive range of the CdS QDSSC to encompass higher energy photons. QDSSCs fabricated with CQDs-incorporated photoanode, a sulfide redox couple, and a Pt counter electrode exhibited a 31.3 % enhancement in power conversion efficiency, leading to a 1.68 % efficiency compared to the 1.28 % efficiency of the pristine TiO2 photoanode.

Atomic oxygen in low Earth orbit erodes polyimide, increasing surface roughness and degrading performance. The reactive species scission polymer chains and remove surface material, exposing fresh sites that accelerate further attack and disrupt thermal, electrical, and mechanical functions. In this paper, we evaluate nanoscale reinforcements of polyimide with graphene and metal oxides under controlled atomic oxygen exposure equivalent to 145 days at a 550 km orbit. Graphene with a thickness of few nanometers and particle size less than 2 µm, and metal oxides zirconia, zinc oxide, and titania with particle size less than 100 nm were investigated. Hybrids containing graphene plus metal oxide at a 1:1 ratio and a total loading of 0.75 wt% increased roughness relative to neat polyimide, with graphene-zirconia showing a rise of +121 percent, graphene-zinc oxide +10 percent, and graphene-titania +20 percent. The behavior is consistent with agglomeration, incomplete dispersion, and interfacial mismatch that hinder uniform blocking of atomic oxygen and limit formation of protective oxygenated groups. In contrast, single-filler composites at 0.75 wt% reduced average roughness, with graphene lowering Sa by about 59 percent, zirconia by about 51%, titania by about 47%, and zinc oxide by about 47%. Varying graphene loading from 0.25 to 0.75 wt% diminished erosive features at the higher end, but atomic force microscopy revealed isolated tall peaks at 0.75 wt%, indicating localized restacking or agglomeration. Mechanical testing of graphene-reinforced coatings on fiberglass showed a similar trade-off, with tensile strength around 23 MPa and peak load greater than 50 N at 0.5 wt% compared to about 21 MPa and 40 N at 0.75 wt%, while strain at break remained comparable. These results define practical limits for nanoparticle reinforcement in polyimide, linking filler identity, loading, and dispersion quality to atomic oxygen response and sustained function in LEO.

In space agriculture, a soil-free cultivation method with low system complexity and mass, hydroponics offers passive aeration, automation, and a means to overcome inefficient distribution of water and limited convective mixing of substrate-based growth systems under micro- and low gravity conditions. Incorporation of local regolith into the hydroponics system has been considered as a step towards in situ resource utilisation, however previous studies demonstrated reduced growth and stress morphologies in plants grown in regolith. This study explores whether cold atmospheric plasma (CAP) treatment can be used to improve the quality of water enriched with regolith particles, and thus enhance the growth, yield and vitality of microgreens. CAP treatment of Simulated Martian Regolith (W-SMR) water for 10 or 30 min increased shoot length of Brassica oleracea by 114% and 89%, and Medicago sativa by 218% and 195%, respectively. For Simulated Lunar Regolith (W-SLR), CAP treatment increased shoot length of M. sativa by 113% and 88%, and B. oleracea by 108% and 129%. Root length also increased, notably for M. sativa in W-SLR and B. oleracea in W-SMR, with smaller effects for M. sativa in W-SMR. CAP treatment was found to alter the concentration of essential elements known to affect plant development, increasing the concentrations of 24Mg, 31P, 39K, 66Zn, and 44Ca known to promote plant growth, while reducing the concentrations of 51V and 27Al that may be responsible for a greater level of stress in plants grown in untreated solutions due to their influence on enzymatic processes. These results confirm the potential of CAP treatment to improve productivity of hydroponic systems that utilise local regolith as an alternative to closed loop systems.

Erosion detection in materials exposed to plasma-generated species, such as those used for space propulsion systems, is critical for ensuring their reliability and longevity. This study introduces an efficient image processing technique to monitor the evolution of the erosion depth in boron nitride (BN) subjected to multiple cycles of iodine plasma exposure. Utilising atomic force microscopy (AFM) images from both untreated and treated BN samples, the technique uses a modified semi-automated image registration method that accurately aligns surface profiles—even after substantial erosion—and overcomes challenges related to changes in the eroded surface features. The registered images are then processed through frequency-domain subtraction to visualise and quantify erosion depth. Our technique tracks changes across the BN surface at multiple spatial locations and generates erosion maps at exposure durations of 24, 48, 72 and 84 min using both one-stage and multi-stage registration methods. These maps not only reveal localised material loss (up to 5.5 μm after 84 min) and assess its uniformity but also indicate potential re-deposition of etched material and redistribution across the surface through mechanisms such as diffusion. By analysing areas with higher elevations and observing plasma-treated samples over time, we notice that these elevated regions—initially the most affected—gradually decrease in size and height, while overall erosion depth increases. Progressive surface smoothing is observed with increasing iodine plasma exposure, as quantified by AFM-based erosion mapping. Notably, up to 89.3% of surface heights were concentrated near the mean after 72–84 min of plasma treatment, indicating a more even distribution of surface features compared to the untreated surface. Iodine plasma was compared to argon plasma to distinguish material loss during degradation between these two mechanisms. Iodine plasma causes more aggressive and spatially selective erosion, strongly influenced by initial surface morphology, whereas argon plasma results in milder and more uniform surface changes. Additional scale-dependent slope and curvature analyses confirm that iodine rapidly smooths fine features, whereas argon better preserves surface sharpness over time. Tracking such sharpness is critical for maintaining the fine structures essential to the fabrication of modern semiconductor components. Overall, this image processing tool offers a powerful and adaptable method for accurately assessing surface degradation and morphological changes in materials used in plasma-facing and space propulsion environments.

Polyimides have a long history of use in space missions, with Kapton® being the first polymer material to touch the surface of the Moon. Polyimides offer remarkable mechanical strength, superior thermal stability, and resistance to radiation, chemicals, and wear, and as such are often serve as a thermal barrier and a protective layer against extreme radiation and temperatures in multi-layer insulation systems. While the use of Kapton® in spacesuits dates back to the two aluminised Kapton® layers used in the spacesuits in the Apollo 11 mission, the potential uses of polyimides in the design of spacesuits remain underexplored, particularly considering the advancement made in the development of high-performance polyimide-based composites. This review explores the opportunities that emerge when the desirable properties of polyimides are combined with that of nanomaterials, specifically carbon nanomaterials, to produce strategic material combinations that promise to achieve enhanced thermal and mechanical properties, improved resistance to abrasion and puncture, and potentially reduced weight compared to traditional spacesuit materials. In turn, these advancements will contribute to the development of next-generation spacesuits that offer superior comfort, protection, and astronaut mobility during extravehicular activities.

Development of sustainable agriculture on Mars is a critical step towards its colonisation. However, Martian regolith is coarse-grained, and its mineral profile differs significantly from that of terrestrial arable soil, resulting in poor seed germination success and stunted plant development. This study investigates whether germination success and plant growth can be improved by exposing seeds and plants to water enriched with either i) biochemically active reactive oxygen and nitrogen species generated by atmospheric pressure plasma (PAW) or (ii) nano-/micro-bubbles and minerals such as potassium and calcium extracted from Aquapulse® feldspar (APW), a type of rock that is readily available on Mars, at different stages of the crop lifecycle. As a crop model, microgreen crops of B. oleracea and M. sativa are chosen for their short growth cycle, low resource requirements, and high nutritional value. For B. oleracea crops, soaking of seeds in PAW followed by irrigation with APW led to an increase in germination by ~566.7%, in biomass by 412.4%, and in chlorophyll content by 17.7% compared to crops grown using normal water for seed soaking and irrigation. For M. sativa crops, the use of APW for soaking and irrigation yielded an increase of 41.7% in seed germination and 45.2% in crop biomass, whereas the use of PAW for both soaking and irrigation resulted in the greatest improvement in seed germination, 41.7%, when compared to control. These results suggest that, with further optimisation, a regiment of treatment with PAW and APW in place of normal water can be used to address stage-specific challenges of the crop lifecycle in Martian regolith. As amending Martian regolith with a minimum of 1% organic matter is required to promote healthy plant development, further studies should investigate the use of plasma-mediated reforming of biowaste for in situ production of e.g., biochar.

The conversion efficiency of a thermoelectric power generator depends on the dimensionless figure-of-merit (ZT) of the constituent thermoelectric materials, which is mainly determined by their Seebeck coefficient as well as the electrical and thermal conductivity. ZnO holds promise for thermoelectric applications, yet its use is currently limited by low electrical conductivity and high thermal conductivity. Herein, we demonstrate how thermal conductivity of ZnO can be significantly reduced by intelligently combining it with a cellulose-based Ag fabric using a one-step hydrothermal method, and how different ratios of zinc nitrate hexahydrate (ZNH) to hexamethylenetetramine (HMT) can be used to fine-tune the thermoelectric performance of the resulting composite. We show that as-prepared samples have a composite structure of Ag, Zn and O without any other impurity phases. We propose that the facet dependent crystal growth orientation, from the c-axis in (101) planes to the a-axis in (100) plane, amplify phonon scattering within the material, impeding effective heat transfer and thereby lowering overall thermal conductivity to 0.046 W/mK at room temperature for composites with a 1:1 ZNH to HMT ratio.

Global environmental, social, and economic challenges call for innovative solutions to food production. Current food production systems require advances beyond traditional paradigms, acknowledging the complexity arising from sustainability and a present lack of awareness about technologies that may help limit, for example, loss of nutrients from soil. Aquaponics, a closed-loop system that combines aquaculture with hydroponics, is a step towards the more efficient management of scarce water, land, and nutrient resources. However, its large-scale use is currently limited by several significant challenges of maintaining desirable water chemistry and pH, managing infections in fish and plants, and increasing productivity efficiently, economically, and sustainably. This paper investigates the opportunities presented by plasma technologies in meeting these challenges, potentially opening new pathways for sustainability in food production.

The emergence of antibiotic resistant microorganisms possesses a great threat to human health and the environment. Considering the exponential increase in the spread of antibiotic resistant microorganisms, it would be prudent to consider the use of alternative antimicrobial agents or therapies. Only a sustainable, sustained, determined, and coordinated international effort will provide the solutions needed for the future. Plant secondary metabolites show bactericidal and bacteriostatic activity similar to that of conventional antibiotics. However, to effectively eliminate infection, secondary metabolites may need to be activated by heat treatment or combined with other therapies. Cold atmospheric plasma therapy is yet another novel approach that has proven antimicrobial effects. In this review, we explore the physiochemical mechanisms that may give rise to the improved antimicrobial activity of secondary metabolites when combined with cold atmospheric plasma therapy.

A highly complex and dynamic process, wound healing can be compromised or slowed down by infection or chronic illness. Phototherapy can be effectively used to inactivate a wide range of pathogenic bacterial in the wound bed, as well as promote tissue regeneration and angiogenesis. Photothermal hydrogel wound dressings provide an attractive avenue for the delivery of photothermal agents to the wound bed with a high degree of control over their distribution, while also providing a protective barrier and a moist environment for the wound. Their efficacy in promoting wound healing can be further extended through the intelligent incorporation of other active agents, including drugs and conductive nanoparticles, that enable controlled delivery of chemical, electrical and physical stimulation. This chapter reviews recent progress in the development of hydrogel dressings for wound healing, highlighting some of the challenges and opportunities for the development of these material platforms.

Recent advancements in space technology and reduced launching cost led companies, defence and government organisations to turn their attention to low Earth orbit (LEO) and very low Earth orbit (VLEO) satellites, for they offer significant advantages over other types of spacecraft and present an attractive solution for observation, communication and other tasks. However, keeping satellites in LEO and VLEO presents a unique set of challenges, in addition to those typically associated with exposure to space environment such as damage from space debris, thermal fluctuations, radiation and thermal management in vacuum. The structural and functional elements of LEO and especially VLEO satellites are significantly affected by residual atmosphere and, in particular, atomic oxygen (AO). At VLEO, the remaining atmosphere is dense enough to create significant drag and quicky de-orbit satellites; thus, thrusters are needed to keep them on a stable orbit. Atomic oxygen-induced material erosion is another key challenge to overcome during the design phase of LEO and VLEO spacecraft. This review covered the corrosion interactions between the satellites and the low orbit environment, and how it can be minimised through the use of carbon-based nanomaterials and their composites. The review also discussed key mechanisms and challenges underpinning material design and fabrication, and it outlined the current research in this area.

Graphene nanostructures exhibit a wide range of remarkable properties suitable for many applications, including those in the field of biomedical engineering. In this work, plasma-enhanced chemical vapor deposition was utilized at different applied RF power for the fabrication of vertical graphene nanowalls on silicon and quartz substrates from an inherently volatile carbon precursor without the use of any catalyst. AFM confirmed the presence of very sharp exposed graphene edges, with associated high surface roughness. The hydrophobicity of the material increased with the power of deposition, reaching the water contact angle of 123 ˚ for 500 W. Confocal scanning laser microscopy demonstrated that the viability of gram-negative Escherichia coli and gram-positive Staphylococcus aureus cells were 33% and 37% when incubated on graphene samples, respectively, compared to controls (quartz) that showed the viability of 82% and 84%, respectively. SEM verified significant morphological damage to bacterial cell walls by the sharp edges of graphene walls, with cells appearing abnormal and deformed. The presented data clearly contributed to the current understanding of the mechanical-bactericidal mechanism of vertically oriented graphene nanowalls upon direct contact with microorganisms.

Carbon quantum dots (CQDs, C‐dots or CDs) are an emerging type of nanomaterial which has received immense attention due to their numerous applications. However, most of the reported CQDs in literature typically emit single emission peak under an excitation. Multipeak emissions without any complicated techniques will be ideal for various applications in the fields of ratiometric sensing, optoelectronics, and multifunctional bio‐imaging systems. Here, a fast, effective, and single‐step method is developed for the bulk synthesis of CQDs using atmospheric pressure air plasmas. Structural, morphological, and chemical properties are characterized by advanced analytical techniques. The CQDs have an average diameter of about 3 nm with a narrow size distribution. Emission wavelengths of 470 nm for blue emissive CQDs and 515 nm for green emissive CQDs are observed. Concentration dependency of the CQDs suggests that the switchable mechanism is due to the formation of PTSA excimers. Dual‐emissive CQDs have the potential to be used in bi‐channel ratiometric determination for metal ions, pH sensing, tumor diagnosis and detection, and solid‐state lighting materials. The proof‐of‐principle demonstration of the use of dual‐emissive CQDs (DCQDs) as a fluorescent sensor of Cu2+ ions is also presented to highlight the possible applications.

Fabrication of efficient CdS quantum dot sensitized solar cell with a novel stable counter electrode based on a thin film of SnO2 is revealed. The film was characterized by using Scanning Electron Microscopy (SEM), High -Resolution Tunneling Microscopy, X-ray diffraction (XRD) and UV-Visible spectroscopic techniques. Photovol-taic performances and Electrochemical Impedance Spectroscopic techniques (EIS) were performed on FTO/TiO2/ CdS/polysulfide/SnO2/FTO device under the light illumination of 100 mW cm(-2) and comparison was done with the conventional Pt counter electrode. Impressive 43 % efficiency enhancement in these solar cells was achieved compared with the Pt based devices. Porous thick nanostructure of SnO2 with crystal defects such as oxygen vacancies and Sn vacancies arising from lattice structures as confirmed by SEM, Raman and, XRD spectroscopy could be some of the reasons for this enhancement. Excellent photo enhanced electrocatalytic activity against the polysulfide electrolyte is confirmed by EIS and Cyclic Voltammetry studies.

Chalcones enable the biosynthesis of flavonoids which protect plants from infections and parasites and have emerged as valuable medicines against diverse human diseases. The common way to synthesize chalcones through the homogeneous catalytic Claisen-Schmidt condensation reaction is compromised from difficult catalyst recovery, waste generation, side reactions, and low yield. As a solution, solid base catalysts are developed as a green catalytic process. It is still a major challenge to synthesize highly active heterogeneous catalysts with a quick, simple, sustainable, and economical approach in the chalcone synthesis. To address these issues, a simple and sustainable synthesis of chalcones has been accomplished here by the solvent-free Claisen-Schmidt condensation reaction using magnesium oxide (MgO) nanosheets as the catalyst. The heterogeneous two-dimensional (2D) MgO catalyst was synthesized using salt recovered from inexhaustible seawater, using an atmospheric pressure plasma (APP)-assisted method making the whole method sustainable and potentially economically feasible. The catalytic activity of the 2D nanosheets was compared with irregular MgO nanoparticles. Irregular MgO showed 25% of benzaldehyde and 10% of acetophenone conversion, while 2D MgO showed >99% of conversion of both reactants with a product selectivity of 100%, while no products were formed in the absence of a catalyst. The effect of substituent groups on the benzaldehyde moiety on the catalytic activity was also analysed. The prepared 2D MgO catalyst showed reusability up to three cycles without any significant loss in the catalytic activity.

The Ceylon Journal of Science is a peer-reviewed journal published quarterly by the University of Peradeniya, Sri Lanka in March, June, September and December. It is aimed at publishing high quality research articles on topics related to different disciplines in Science. The journal accepts original research articles, book reviews, reviews and mini-reviews, short communications, opinions, research notes, and commentaries and notes. The Journal has its own website https://site.pdn.ac.lk/cjs/. The journal strictly adheres to publication ethics as emphasized by the Committee on Publication Ethics (COPE). It is indexed in Sri Lanka Journals Online (SLJOL), Directory of Open Access Journals (DOAJ), Google Scholar and Zoological Records. According to the Google Scholar;H5-Index: 12H5-Median: 15According to the Exaly (1970 – 2021);Impact Factor: 0.6 (top 19%)Extended IF: 0.6 (top 19%)H-Index: 8 (top 28%)Citations/paper: 1.42

Antibiotics have been extensively used as pharmaceuticals for diverse applications. However, their overuse and indiscriminate discharge to water systems have led to increased antibiotic levels in our aquatic environments, which poses risks to human and livestock health. Non-thermal plasma water. However, the issues of process scalability and the mechanisms towards understanding the plasma-induced degradation remain. This study ad-dresses these issues by coupling a non-thermal plasma jet with a continuous flow reactor to reveal the effective mechanisms of amoxicillin degradation. Four industry-relevant feeding gases (nitrogen, air, argon, and oxygen), discharge voltages, and frequencies were assessed. Amoxicillin degradation efficiencies achieved using nitrogen and air were much higher compared to argon and oxygen and further improved by increasing the applied voltage and frequency. The efficiency of plasma-induced degradation depended on the interplay of hydrogen peroxide (H2O2) and nitrite (NO2-), validated by mimicked chemical solutions tests. Insights into prevailing degradation pathways were elucidated through the detection of intermediate products by advanced liquid chromatography-mass spectrometry.

Rational: The mutating SARS-CoV-2 potentially impairs the efficacy of current vaccines or antibody-based treatments. Broad-spectrum and rapid anti-virus methods feasible for regular epidemic prevention against COVID-19 or alike are urgently called for. Methods: Using SARS-CoV-2 virus and bioengineered pseudoviruses carrying ACE2-binding spike protein domains, we examined the efficacy of cold atmospheric plasma (CAP) on virus entry prevention. Results: We found that CAP could effectively inhibit the entry of virus into cells. Direct CAP or CAP-activated medium (PAM) triggered rapid internalization and nuclear translocation of the virus receptor, ACE2, which began to return after 5 hours and was fully recovered by 12 hours. This was seen in vitro with both VERO-E6 cells and human mammary epithelial MCF10A cells, and in vivo. Hydroxyl radical (·OH) and species derived from its interactions with other species were found to be the most effective CAP components for triggering ACE2 nucleus translocation. The ERα/STAT3(Tyr705) and EGFR(Tyr1068/1086)/STAT3(Tyr705) axes were found to interact and collectively mediate the effects on ACE2 localization and expression. Conclusions: Our data support the use of PAM in helping control SARS-CoV-2 if developed into products for nose/mouth spray; an approach extendable to other viruses utilizing ACE2 for host entry.

SnO2 is an attractive semiconducting material which can be used in place of TiO2 in dye–sensitized solar cells (DSSCs) due to the wide energy band gap, good photostability and high charge carrier mobility. Here we report the use of plasmon resonance effect by gold nanoparticles of size 70–80 nm for efficiency enhancement in solar cells made with SnO2 photoanodes and sensitized with Indoline D149 dye. Devices were characterized by current density–voltage (J–V) curves, incident photon–to– electron conversion efficiency (IPCE) spectroscopy and electron impedance spectroscopy (EIS). DSSCs fabricated with pristine SnO2 photoanode showed efficiency of (η) 2.28%, under the illumination of 100 mW cm-2 (AM 1.5), whereas DSSCs fabricated with optimized Au nanoparticles in the SnO2 photoanode showed efficiency of 2.89% having more than 26% enhancement. This increase is mainly attributed to the 42% increase in the short circuit current density from 6.48 mA cm-2 to 9.19 mA cm-2 caused by the plasmonic effect by Au nanoparticles. The IPCE was also increased due to the use of Au@SnO2. According to the EIS analysis, the incorporation of plasmonic Au nanoparticles has led to a 35% decrease in the interfacial charge transfer resistance (RCT2) at the SnO2 photoanode/electrolyte interface which is associated with the increased rate of charge transfer at this interface and increased resulting the efficiency of the solar cells.