Respiratory gymnastics for students with cardiological diseases

Purpose: to give scientific justification to the technique of performing breathing exercises by students with cardiological diseases. It is confirmed the expediency of systematic application of the breathing exercises with a full breath and interval hypoxia. Conclusions: It is expedient to perform breathing exercises on the classes of the subject "Physical culture" with the students suffer from cardiological disease

Polypropylene-based Eco-composites Filled with Agricultural Rice Hulls Waste

In this workthe properties of rice-hull-filled polypropylene (PP) composites were investigated with the purpose of enhancing adhesion between the polymer and the filler through the addition of w = 5 % PP-grafted-MA (CA). Composites containing w = 20 and 30 % rice hulls (RH), as well as composites with a certain amount of PP matrix substituted with a coupling agent, were prepared by extrusion and compression moulding. The composites’ mechanical properties were investigated through tensile and fracture tests at low and high strain rate, using the concept of linear elastic fracture mechanics. Introduction of rice hulls in the PP matrix resulted in a decreased stress at peak, together with increase of composites tensile modulus (EPP = 1013 MPa, EPP/RH (ζ = 0.70:0.30) = 1690 MPa) and modulus in flexure. Introduction of w = 5 % PP-g-MA caused 6 % and 12 % improvement in the composite tensile strength, respectively for the PP composites with w = 20 and 30 % rice hulls. Modulus in flexure for the composite PP/RH/CA (ζ = 0.65:0.30:0.05) reached Ef = 1646 MPa, which was an improvement of 52 % when compared to pure polypropylene. Kc and Gc values were determined for PP and PP-based composites. Thermal stability of PP was slightly improved by adding rice hulls

Plant lectins: the ties that bind in root symbiosis and plant defense

Lectins are a diverse group of carbohydrate-binding proteins that are found within and associated with organisms from all kingdoms of life. Several different classes of plant lectins serve a diverse array of functions. The most prominent of these include participation in plant defense against predators and pathogens and involvement in symbiotic interactions between host plants and symbiotic microbes, including mycorrhizal fungi and nitrogen-fixing rhizobia. Extensive biological, biochemical, and molecular studies have shed light on the functions of plant lectins, and a plethora of uncharacterized lectin genes are being revealed at the genomic scale, suggesting unexplored and novel diversity in plant lectin structure and function. Integration of the results from these different types of research is beginning to yield a more detailed understanding of the function of lectins in symbiosis, defense, and plant biology in general

Rice straw as an alternative reinforcement in polypropylene composites

We studied the use of rice straw as reinforcement in maleated polypropylene (PPm). Composites containing 20 and 30% by weight rice straw were successfully prepared by extrusion and compression molding. The samples were characterized by tensile tests, differential scanning calorimetry (DSC), thermogravimetry (TGA), dynamo-mechanical analysis (DMTA) and scanning electron microscopy (SEM). The results of the mechanical properties showed that rice straw can be used as an alternative reinforcement for polypropylene. Higher tensile moduli (E) were obtained for composites containing higher rice straw content. Thermogravimetric curves of the composites exhibit two-stage decomposition process and slightly higher thermal stability. Higher crystallization (Tc) and melting peak temperatures for composites were detected by DSC analysis (Tcpp = 107.8 °C, TcRS/PP(20/80) = 114.5 °C). The renewability of rice straw and the recyclability of thermoplastic polypropylene provide an attractive eco-friendly quality to the resulting composites