The Potential Application of Starch and Walnut Shells as Biofillers for Natural Rubber (NR) Composites.

The goal of this study was application of corn starch and ground walnut shells in various amounts by weight as biofillers of natural rubber (NR) biocomposites. Additionally, ionic liquid 1-butyl-3-methylimidazolium chloride (BmiCl) and (3-aminopropyl)-triethoxysilane (APTES) were used to increase the activity of biofillers and to improve the curing characteristics of NR composites. The effect of biofillers used and their modification with aminosilane or ionic liquid on the curing characteristics of NR composites and their functional properties, including crosslink density, mechanical properties in static and dynamic conditions, hardness, thermal stability and resistance to thermo-oxidative aging were investigated. Starch and ground walnut shells were classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk. BmiCl and APTES were successfully used to support the vulcanization and to improve the dispersion of biofillers in NR elastomer matrix. Vulcanizates with starch, especially those containing APTES and BmiCl, exhibited improved tensile properties due to the higher crosslink density and homogenous dispersion of starch, which resulted from BmiCl addition. NR filled with ground walnut shells demonstrated improved resistance to thermo-oxidative aging. It resulted from lignin present in walnut shells, the components of which belong to polyphenols, that have an antioxidant activity.

[Depression in children and adolescents -symptoms, etiology, therapy]. / Depresja u dzieci i mlodziezy-obraz kliniczny, etiologia, terapia.

Early onset depression, regarding its high prevalence and debilitating effects on development, is considered to be one of the major mental illness in children and adolescents. Most commonly is recurrent and continues in adulthood. Factors determining vulnerability to depression can be grouped into following categories: genetics, familial environment, personal characteristics and severe stress. Main risk factors include: being a female, family history of depression, subclinical symptoms, negative cognitive style, negative life events. Common symptoms of depression can be different in children and teens than they are in adults. Often occur with atypical features. The diagnosis might be problematic as it often relays on the observation of children's dysfunctions. Therefore treatment of major depression in children and adolescents is considered difficult. It is important to estimate all the features that underlie the symptoms, their persistence, and then implement proper therapy.