Abstract: Objectives: In recent years, the Faculty of Dentistry of the University of Hong Kong have extended the implementation of 3D electronic models (e-models) into problem-based learning (PBL) of the Bachelor of Dental Surgery (BDS) curriculum, aiming at mutual enhancement of PBL teaching quality and the students’ skills in using e-models. This study focuses on the effectiveness of e-models serving as a tool to enhance the students’ skills and competences in PBL. Methods: The questionnaire surveys are conducted to measure 50 fourth-year BDS students’ attitude change between beginning and end of blended PBL tutorials. The response rate of this survey is 100%. Results: The results of this study show the students’ agreement on enhancement of their learning experience after e-model implementation and their expectation to have more blended PBL courses in the future. The potential of e-models in cultivating students’ self-learning skills reduces their dependence on others, while improving their communication skills to argue about pros and cons of different treatment options. The students’ independent thinking ability and problem solving skills are promoted by e-model implementation, resulting in better decision making in treatment planning. Conclusion: It is important for future dental education curriculum planning to cope with the students’ needs, and offer support in the form of software, hardware and facilitators’ assistance for better e-model implementation.
Abstract: A field study was conducted to evaluate the efficacy
of lavender for phytoremediation of contaminated soils. The
experiment was performed on an agricultural fields contaminated by
the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. The
concentrations of Pb, Zn and Cd in lavender (roots, stems, leaves and
inflorescences) and in the essential oils of lavender were determined.
Lavender is a plant which is tolerant to heavy metals and can be
grown on contaminated soils, and which can be referred to the
hyperaccumulators of lead and the accumulators of cadmium and
zinc, and can be successfully used in the phytoremediation of heavy
metal contaminated soils. Favorable is also the fact that heavy metals
do not influence the development of the lavender, as well as on the
quality and quantity of the essential oil. The possibility of further
industrial processing will make lavender economically interesting
crops for farmers of phytoextraction technology.
Abstract: The alternative technique for sterilization of culture
medium to replace autoclaving was carried out. For sterilization of
culture medium without autoclaving, some commercial pure essential
oils, bergamot oil, betel oil, cinnamon oil, lavender oil and turmeric
oil, were tested alone or in combinations with some disinfectants,
10% povidone-iodine and 2% iodine + 2.4% potassium iodide. Each
essential oil or combination was added to 25-mL Murashige and
Skoog (MS) medium before medium was solidified in a 120-mL
container, kept for 2 weeks before evaluating sterile conditions.
Treated media, supplemented with essential oils, were compared to
control medium, autoclaved at 121 degree Celsius for 15 min. In
vitro sterile conditions were found 20 – 100% from these treated
media compared to 100% sterile condition from autoclaved medium.
Treated media obtained 100% sterile conditions were chosen for
culturing chrysanthemum shoots. It was found that 10% povidoneiodine
in combination with cinnamon oil (3:1) and 2% iodine + 2.4%
potassium iodide in combination with lavender oil (1:3) at the
concentration of 36 3L/25 mL medium provided the promising
growth of shoot explants.
Abstract: Plant tissue culture is an important in vitro technology applied for agricultural and industrial production. A sterile condition of culture medium is one of the main aspects. The alternative technique for medium sterilization to replace autoclaving was carried out. For sterilization of plant tissue culture medium without autoclaving, ten commercial pure essential oils and 5 disinfectants were tested. Each essential oil or disinfectant was added to a 20-mL Murashige and Skoog (MS) medium before medium was solidified in a 120-mL container, kept for 2 weeks before evaluating sterile conditions. Treated media, supplemented with essential oils or disinfectants, were compared to control medium, autoclaved at 121 degree Celsius for 15 min. Sterile conditions of MS medium were found 100% from betel oil or clove oil (18 mL/20 mL medium), cinnamon oil (36 mL/20 mL medium), lavender oil or holy basil oil (108 mL/20 mL medium), and lemon oil or tea tree oil or turmeric oil (252 mL/20 mL medium), compared to 100% sterile condition from autoclaved medium. For disinfectants, 2% iodine + 2.4% potassium iodide, 2% merbromine solution, 10% povidone-iodine, 6% sodium hypochlorite or 0.1% thimerosal at 36 mL/20 mL medium provided 100% sterile conditions. Furthermore, growth of new shoots from chrysanthemum node explants on treated media (fresh weight, shoot length, root length and number of node) were also reported and discussed in the comparison of those on autoclaved medium.