Scientifica

Stevia rebaudiana Bert. is commonly known as candy leaf, sugar leaf, or sweet leaf. It is a natural sweetener that has low calories and is used as a substitute for sucrose. The objective of this research is to evaluate the effects of graphene oxide (GO) on the growth, biochemical activities, and stevioside and rebaudioside A production of Stevia in in vitro-raised plantlets. For this, green nanomaterials of GO (0, 2, 4, 6, 8, and 10 mgL⁻¹) were applied to the in vitro plants to enhance its sweetness by triggering the production of stevioside and rebaudioside A and other growth and biochemical parameters. It was observed that all the growth parameters of Stevia plants significantly increased with all GO treatments tested. Total chlorophyll and protein contents were increased (1.85- and 2.65-fold increase from the control) by applying 8 mgL⁻¹ of GO to the MS medium. The maximum value (4 mg·g⁻¹ of protein) of peroxidase activity (POD) was observed by applying 4 mgL⁻¹ of GO, 28.92-fold increase from the control. In comparison, superoxide dismutase activity (SOD) (0.4 mg·g⁻¹ protein) was observed with 10 mgL⁻¹ of GO (1.56-fold increase from the control). Stevioside (12.9 and 8.9 mg·g⁻¹ DW) and rebaudioside A (3.2 and 0.81 mg·g⁻¹ DW) were observed only at 6 and 8 mg·L⁻¹ treatment of graphene oxide. According to the findings, using graphene oxide (GO) had a significant impact on the growth, biochemical activities, and steviol glycoside production in Stevia. This shows that GO has the potential to be a valuable enhancer of sweetness and overall Stevia leaf quality, providing great prospects for the development of low-calorie natural sweeteners.

Finding new catalysts and pyrolysis technologies for efficiently recycling wasted plastics into fuels and structured solid materials of high selectivity is the need of time. Catalytic pyrolysis is a thermochemical process that cracks the feedstock in an inert gas environment into gaseous and liquid fuels and a residue. This study is conducted on microwave-assisted catalytic recycling of wasted plastics into nanostructured carbon and hydrogen fuel using composite magnetic ferrite catalysts. The composite ferrite catalysts, namely, NiZnFe₂O₄, NiMgFe₂O₄, and MgZnFe₂O₄ were produced through the coprecipitation method and characterized for onward use in the microwave-assisted valorization of wasted plastics. The ferrite nanoparticles worked as a catalyst and heat susceptor for uniformly distributed energy transfer from microwaves to the feedstock at a moderate temperature of 450°C. The type of catalyst and the working parameters significantly impacted the process efficiency, gas yield, and structural properties of the carbonaceous residue. The tested process took 2–8 minutes to pulverize feedstock into gas and carbon nanotubes (CNTs), depending on the catalyst type. The NiZnFe₂O₄-catalyzed process produced CNTs with good structural properties and fewer impurities compared to other catalysts. The NiMgFe₂O₄ catalyst performed better in terms of hydrogen evolution by showing 87.5% hydrogen (H₂) composition in the evolved gases. Almost 90% of extractable hydrogen from the feedstock evolved during the first 2 minutes of the reaction.

This study used a combination of leaves extracts from Ruellia tuberosa L. and Tithonia diversifolia plants encapsulated using gum Arabic. The selection of leaves in medicinal plants because they are rich in bioactive compounds that provide health benefits. The encapsulation technique was microencapsulation through freeze-drying, since the nanoencapsulation for the plant extracts is unlikely to be conducted due to their large particle sizes. The resulting microcapsules were then tested their biological activities in vitro. Several conditions affect microcapsules’ production, including pH, gum Arabic concentration, and stirring time were assessed. The optimum conditions were chosen based on the highest encapsulation efficiency. The results showed that the optimum microcapsules preparation was achived at pH 5, gum Arabic concentration of 4% (w/v), and stirring time of 60 min with an encapsulation efficiency of 84.29%. The in vitro assays include inhibition of alpha-amylase and antioxidant activities, resulted in the respective IC₅₀ values of 54.74 μg/mL and 152.74 μg/mL. Releases of bioactive compounds from the microcapsules were investigated under pH 2.2 and pH 7.4 from 30 to 120 min. Results indicated a release of 43.10% at pH 2.2 and 42.26% at pH 7.4 during 120 min, demonstrating the controlled release behavior of the encapsulated bioactive compounds; nonetheless, their release behavior was not pH-dependent. This study confirms that microencapsulation has an important role in the development of plant extracts with maintained biological functions as well as maintaining their stability.

The current research describes the multiplication of Paulownia elongata S. Y. Hu, a timber plant, through the forcing of softwood shoots from epicormic buds under glasshouse conditions in spring and fall seasons. Different growth media were used to compare their effect on the forcing potential of epicormic buds. For this, 25–30-cm-long and 1.2–2-cm-diameter stem segments taken from the lower juvenile portion of a mother plant were placed horizontally in flat trays containing media, i.e., sterilized well-moistened sand, peat moss, perlite, and vermiculite individually. Furthermore, 4–6-cm-long forced softwood shoots were detached and treated with various concentrations of IBA (indole-3-butyric acid) and NAA (α-naphthyl acetic acid) either individually or in combinations for subsequent rooting. The response of shoot forcing was better in spring as compared to fall in terms of shoot length (cm), and number of shoots or leaves; however, an earlier bud break was observed during fall after 30 days of the initial experiment. The use of peat moss and vermiculite proved to be equally suitable for early bud break in both seasons, whereas in terms of shoot and leaf number as well as the shoot length (cm), the best outcome was observed in sand. Best rooting was observed at 3 gL⁻¹ IBA + 3 gL⁻¹ NAA in terms of root number per shoot, root length (cm), and days to root initiation while using sand as the growth medium after 50 days of the rooting experiment. The successfully established plantlets were further shifted to soil at Botanical Garden, University of the Punjab, Lahore, Pakistan, exhibiting an 87.5% survival rate. On the basis of the results obtained, it may be concluded that reasonable softwood shoot forcing in P. elongata may further be exploited for its mass scale nursery propagation as well as use in future in vitro studies.

Background. Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV) and major global health problem, affecting millions of people globally. Whilst college or university students could serve as a positive vehicle that may aid in the propagation of education in the communities, there is currently paucity of data on knowledge of HBV and vaccination awareness among university students in Ghana. This study therefore assessed knowledge on hepatitis B virus infection, testing, and vaccination awareness among science and non-science students in Ghana. Method. This cross-sectional study included 386 students from the Garden City University College, Kumasi, Ghana, from February to June 2022. A well-structured questionnaire was used to obtain data on knowledge, testing, HBV vaccination status, and sociodemographic characteristics of participants. All statistical analyses were done using SPSS Version 26.0 and GraphPad prism version 8.0. A Chi-square test statistic and logistics regression analyses were used to determine factors associated with study variables among study participants. value of <0.05 and 95% confidence interval were considered statistically significant. Results. About half (51.5%) of the participants had adequate knowledge on hepatitis B infection with 22.3% demonstrating poor knowledge on hepatitis B infection. A little more than average (51.6%) previously tested for hepatitis B (HBV) whilst 32.9% were highly aware of hepatitis B vaccination and 33.9% were not aware of hepatitis B vaccination. This study found that ethnicity of students (), family history of hepatitis B infection (), and academic cumulative weighted average (CWA) () were significantly associated with knowledge about hepatitis B infection. Also, students reading science-related programs had more than twice the odds (aOR = 2.56, 95% CI (1.03–5.08), ) of having tested for HBV infections before compared to students who read non-science programs. Furthermore, sex (), family history of HBV vaccination (), CWA (), and the program of students () were significantly associated with awareness of HBV vaccination. Conclusion. Knowledge of HBV infection among university students is satisfactory but awareness of HBV vaccination and testing is poor. There is a need to enhance educational interventions to improve the general knowledge of HBV infection, testing, and vaccination in Ghana especially among non-science students.

With growing environmental concerns and a growing world population, there is an interest in developing cheap, efficient, and environmentally friendly substances that benefit humanity. Microbial surfactants are nontoxic, biodegradable bioproducts that provide sustainable solutions in agricultural applications due to their many benefits over their synthetic counterparts. Hence the crucial importance of scientific research to understand the effect of microbial surfactants on plant development. The present study aimed to assess the effect of rhamnolipid produced by Pseudomonas aeruginosa on seed germination of wheat (Triticum aestivum), barley (Hordeum vulgare), okra (Abelmoschus esculentus), onion (Allium cepa), and lettuce (Lactuca sativa) under laboratory conditions. The results showed that P. aeruginosa was capable of producing 3.83 g/L of viscous, honey-colored rhamnolipid, which was capable of lowering the surface tension to 30 ± 0.33 mN/m. Different concentrations of rhamnolipid ranging from 0.25 to 1.00 g/L were assessed, with distilled water acting as a control. After treatment of seeds, results showed that applying 0.25 g/L of rhamnolipid can significantly increase seed germination to 100% on the fourth day of sowing okra and lettuce, and on the fifth day of sowing onion seeds, compared to control groups that recorded 60%, 50%, and 55%, respectively. In wheat and barley seeds, applying rhamnolipid can protect seeds from pathogenic fungi while delaying their germination to 60% and 70% on the third day of sowing, while 90% and 100% have been reported in the control groups. Thus, this biological molecule demonstrates promising results in enhancing seed germination of the studied species by protecting them from phytopathogens and then aiding plant growth.