Seed cryopreservation of Fraxinus angustifolia Vahl

Fraxinus angustifolia is used for afforestation and for production of both valuable timber and manna, a substance with pharmacological applications. The aim of this research was to establish the optimized condition for cryopreservation of F. angustifolia seeds, in order to protect the germplasm of this species. Germination percentage and mean time of germination of non-treated seeds (control) and liquid nitrogen-treated seeds were established in water or in 10-6 M gibberellic acid (GA3). The seeds could be cryopreserved with 3% of moisture content (MC) and germinated easily in water (70.0 ± 5.0%), while seeds cryopreserved with 6% MC showed a physiological dormancy. This state could be efficiently removed by addition of GA3, which increased germination to 76.0 ± 2.4%. Liquid nitrogen did not impair embryo viability, allowing a successful cryopreservation of seeds. The results are particularly useful for both germplasm conservation programs and in narrow leaved ash nurseries.Keywords: Fraxinus angustifolia, germination, germplasm conservation, seed cryopreservationAfrican Journal of Biotechnology Vol. 12(16), pp. 1930-193

Orthodontic Emergencies and Perspectives During and After the COVID-19 Pandemic: The Italian Experience

Objective: To investigate the types of dental emergencies that occurred during the lockdown period in Italy (12th March—4th May) and to investigate future therapeutic preferences related to the use of different types of appliances. Material and Methods: A questionnaire dedicated to assessing dental emergencies during the lockdown period and surveying the resumption of orthodontic practice was submitted to clinicians in digital form. The first part of the questionnaire, focused on the orthodontic emergencies that were encountered in relation to the different types of orthodontic appliances and how these were resolved. The second part of the questionnaire was devoted to the resumption of clinical practice; in particular, it was designed to assess whether and what percentage of clinicians are willing to change the duration of appointments in relation to the different types of appliance used, asking them whether their approach to orthodontic treatment would change in the coming months as compared to the pre-COVID-19 era. Results: Results show that in most cases (82%), the percentage of patients who experienced a dental emergency was less than 5% and that far fewer emergencies were attributable to removable (5.7%) than to fixed appliances (94.3%). Looking ahead, clinicians expressed a greater preference for using removable (60.8%) rather than fixed appliances (39.2%). Conclusion: During the lockdown, there relatively few orthodontic emergencies, many of which were handled by telephone consultation. However, a far lower percentage of emergencies were generated by removable (e.g., clear aligners) as opposed to fixed appliances (e.g., multibracket equipment), likely influencing the decision of the majority of clinicians to opt for removable appliances in the wake of the COVID-19 pandemic

Orthodontic Emergencies and Perspectives During and After the COVID-19 Pandemic: The Italian Experience

Objective: To investigate the types of dental emergencies that occurred during the lockdown period in Italy (12th March—4th May) and to investigate future therapeutic preferences related to the use of different types of appliances. Material and Methods: A questionnaire dedicated to assessing dental emergencies during the lockdown period and surveying the resumption of orthodontic practice was submitted to clinicians in digital form. The first part of the questionnaire, focused on the orthodontic emergencies that were encountered in relation to the different types of orthodontic appliances and how these were resolved. The second part of the questionnaire was devoted to the resumption of clinical practice; in particular, it was designed to assess whether and what percentage of clinicians are willing to change the duration of appointments in relation to the different types of appliance used, asking them whether their approach to orthodontic treatment would change in the coming months as compared to the pre-COVID-19 era. Results: Results show that in most cases (82%), the percentage of patients who experienced a dental emergency was less than 5% and that far fewer emergencies were attributable to removable (5.7%) than to fixed appliances (94.3%). Looking ahead, clinicians expressed a greater preference for using removable (60.8%) rather than fixed appliances (39.2%). Conclusion: During the lockdown, there relatively few orthodontic emergencies, many of which were handled by telephone consultation. However, a far lower percentage of emergencies were generated by removable (e.g., clear aligners) as opposed to fixed appliances (e.g., multibracket equipment), likely influencing the decision of the majority of clinicians to opt for removable appliances in the wake of the COVID-19 pandemic

Silicon Quasi‐One‐Dimensional Nanostructures for Photovoltaic Applications

Thanks to the silicon abundance, stability, non-toxicity and well known electronic properties, Si based solar cells have represented the leading actors in the photovoltaic market and future projections confirm this predominance. However, half of the module cost is due to the material consumption and processing. In order to decrease the costs, a cut in the Si consumption must be operated, with consequent decrement in the optical absorption, generated current and device efficiency. To keep the performance level, a proper Si surface design with the objective to trap the light, has been developed. One of the most popular approaches is to use silicon nanowires embedded in the solar cell emitter where they play the role of optically and electrically active layer, thanks to their excellent optical absorption properties. However, also another material has been the terminus of the light-trapping materials, the silicon nanoholes. Their mechanical robustness is superior, making their integration inside the cell easier and cost-effective. The review will bring about all of the most common methods to fabricate these two types of nanostructures when used for solar cells applications, their optical properties and some critical aspects related to their high surface to volume ratio which modify the recombination processes

Isolation and characterization of SPOROMUSA ACIDOVORANS sp. nov., a methylogrophic homoacetogenic bacterium

SPOROMUSA ACIDOVORANS sp. nov. was isolated from a pilot fermenter inoculated with effluent sample from the alcohol distillation industry. The isolate was a Gram-negative, motile, curved, spore-forming rod. The DNA base composition was 42 % G+C. The temperature range for growth was 20 to 40°C, with an optimum at 35°C ; growth occurred within a pH range of 5.4 to 7.5, with an optimum at pH 6.5. Growth substrates included methanol, H2-CO2, formate, fructose, ribose, fumarate, succinate and glycerol. Yeast extract was required for growth. The organism performed the homoacetogenic reaction. (Résumé d'auteur

Identification of structural alerts for liver and kidney toxicity using repeated dose toxicity data

Background: The potential for a compound to cause hepatotoxicity and nephrotoxicity is a matter of extreme interest for human health risk assessment. To assess liver and kidney toxicity, repeated-dose toxicity (RDT) studies are conducted mainly on rodents. However, these tests are expensive, time-consuming and require large numbers of animals. For early toxicity screening, in silico models can be applied, reducing the costs, time and animals used. Among in silico approaches, structure-activity relationship (SAR) methods, based on the identification of chemical substructures (structural alerts, SAs) related to a particular activity (toxicity), are widely employed. Results: We identified and evaluated some SAs related to liver and kidney toxicity, using RDT data on rats taken from the hazard evaluation support system (HESS) database. We considered only SAs that gave the best percentages of true positives (TP). Conclusions: It was not possible to assign an unambiguous mode of action for all the SAs, but a mechanistic explanation is provided for some of them. Such achievements may help in the early identification of liver and renal toxicity of substances

Efficacy of swm appliance in the expression of first-, second- and third-order information in Class I and Class II

To assess the efficacy of a multibracket appliance?Straight-wire Mirabella (SWM) prescription?in terms of achieving the ideal first-, second- and third-order values proposed by Andrews. A total sample of 46 Caucasian subjects was divided into two groups: 23 with class I malocclusion (Group 1), and 23 with class II malocclusion (Group 2). The treatment protocol involved fixed multibracket appliances?SWM prescription?for both groups, with the addition of class II elastics for Group 2. Values for ?U1-PP, ?IMPA, in-out, tip and torque were measured on digital scans, and the results obtained were compared with the ideal values proposed by Andrews. Statistically significant differences were revealed between the entire sample and Andrews? values for: in-out on upper lateral incisors and upper canines; tip on the upper first premolars, upper second premolars, upper first molars and upper canines; and torque on the lower central incisors, lower lateral incisors, lower canines and lower first premolars. However, comparison of Groups 1 and 2 revealed statistically significant differences only at the lower lateral incisors. The use of class II elastics influenced ?IMPA values, but not ?U1-PP. The efficacy of the multibracket appliance?SWM prescription?in expressing first- second- and, to a lesser extent, third-order information was demonstrated in both class I and class II malocclusions. Class II elastics only influenced the third-order expression on the lower lateral incisors and the ?IMPA