ABSTRACT
The agricultural use of silica (SiO2) nanoparticles (NPs) has the potential to control insect pests while the safety and tritrophic effects on plants and beneficial natural enemies remains unknown. Here, we evaluate the effects of silica NPs on insect pests with different feeding niches, natural enemies, and a plant. Silica NPs were applied at different concentrations (75-425 mg/L) on field-cultivated faba bean and soybean for two growing seasons. The faba bean pests, the cowpea aphid Aphis craccivora and the American serpentine leafminer Liriomyza trifolii, and the soybean pest, the cotton leafworm Spodoptera littoralis, were monitored along with their associated predators. Additional laboratory experiments were performed to test the effects of silica NPs on the growth of faba bean seedlings and to determine whether the rove beetle Paederus fuscipes is attracted to cotton leafworm-infested soybean treated with silica NPs. In the field experiments, silica NPs reduced the populations of all three insect pests and their associated predators, including rove beetles, as the concentration of silica NPs increased. In soybean fields, however, the total number of predators initially increased after applying the lowest concentration. An olfactometer-based choice test found that rove beetles were more likely to move towards an herbivore-infested plant treated with silica NPs than to a water-treated control, suggesting that silica NPs enhance the attraction of natural enemies via herbivore-induced plant volatiles. In the laboratory, while silica NPs inhibited the development of faba bean roots at 400 mg/L, they did not affect germination percentage, germination time, shoot length, or vigor index compared to the control.
Subject(s)
Insecta/drug effects , Insecta/physiology , Insecticides/pharmacology , Nanoparticles , Animals , Aphids/drug effects , Aphids/physiology , Coleoptera/drug effects , Coleoptera/physiology , Dose-Response Relationship, Drug , Egypt , Germination/drug effects , Insecticides/chemistry , Nanoparticles/chemistry , Population Density , Predatory Behavior/drug effects , Silicon Dioxide , Glycine max , Spodoptera/drug effects , Spodoptera/physiology , Vicia faba/drug effects , Vicia faba/growth & developmentABSTRACT
BACKGROUND: Fractional CO2 laser and platelet-rich plasma (PRP) treatments have been used in the treatment of acne scars. However, an objective method of assessment has been lacking. OBJECTIVE: To evaluate the efficacy of CO2 laser versus the combination of PRP and fractional CO2 laser in treatment of acne scar. PATIENTS AND METHODS: Thirty patients with atrophic acne scar lesions were included in this study. Patients were randomized to receive fractional CO2 laser therapy to one side of the face while the other side of the face was treated with fractional CO2 laser followed by intradermal PRP injection. Follow-up using the skin analysis camera system and photography was done for three months. RESULTS: A dramatic improvement was observed in the scar depth on both sides of the face. However, the combined fractional CO2 laser and PRP showed more significant improvement. Improvements in the scar appearance and skin texture were reported by the patients. Although 70% of our patients were of a dark skin type, no hyperpigmentation was reported. CONCLUSION: The combined use of fractional CO2 laser and PRP achieved better results. It reduced the downtime of the fractional CO2 laser. The use of the skin analysis camera provided an objective assessment of the results.
Subject(s)
Acne Vulgaris/complications , Blood Transfusion, Autologous/methods , Cicatrix/therapy , Lasers, Gas/therapeutic use , Platelet-Rich Plasma , Adult , Cicatrix/diagnosis , Cicatrix/etiology , Combined Modality Therapy/instrumentation , Combined Modality Therapy/methods , Face , Female , Humans , Image Processing, Computer-Assisted , Injections, Intradermal , Male , Patient Satisfaction , Photography , Skin/diagnostic imaging , Skin/radiation effects , Treatment Outcome , Young AdultABSTRACT
With the high population growth rate, especially in developing countries, and the scarcity of land resources, buildings are becoming so close to each other, depriving the lower floors and the alleys from sunlight and consequently causing health problems. Therefore, there is an urgent need for cost-effective efficient light redirecting panels that guide sun rays into those dim places. In this paper, we address this problem. A novel sine wave based panel is presented to redirect/diverge light downward and enhance the illumination level in those dark places. Simulation results show that the proposed panel improves the illuminance values by more than 200% and 400% in autumn and winter respectively, operates over wide solar altitude ranges, and redirects light efficiently. Experimental and simulation results are in good agreement.
