Wroclaw University of Environmental and Life Sciences

About: Wroclaw University of Environmental and Life Sciences is a education organization based out in Wrocław, Poland. It is known for research contribution in the topics: Population & GNSS applications. The organization has 3108 authors who have published 6672 publications receiving 57774 citations.

Curvature properties of some class of warped product manifolds

Abstract: Warped product manifolds with p-dimensional base, p=1,2, satisfy some curvature conditions of pseudosymmetry type. These conditions are formed from the metric tensor g, the Riemann-Christoffel curvature tensor R, the Ricci tensor S and the Weyl conformal curvature C of the considered manifolds. The main result of the paper states that if p=2 and the fibre is a semi-Riemannian space of constant curvature, if n is greater or equal to 4, then the (0,6)-tensors R.R - Q(S,R) and C.C of such warped products are proportional to the (0,6)-tensor Q(g,C) and the tensor C is expressed by a linear combination of some Kulkarni-Nomizu products formed from the tensors g and S. Thus these curvature conditions satisfy non-conformally flat non-Einstein warped product spacetimes (p=2, n=4). We also investigate curvature properties of pseudosymmetry type of quasi-Einstein manifolds. In particular, we obtain some curvature property of the Goedel spacetime.

Volatile Composition and Sensory Properties as Quality Attributes of Fresh and Dried Hemp Flowers (Cannabis sativa L.)

Abstract: Flowers of hemp (Cannabis sativa L.) are widely used in cosmetics, food, and in the pharmaceutical industry. The drying process plays a key role in retention of aroma and also in the quality of products. Seven variants of hemp flower drying, including convection drying (CD), vacuum-microwave drying (VMD), and combined drying consisting of convective pre-drying followed by vacuum-microwave finishing drying (CPD-VMFD) were checked in this study. For each process, we applied the two-term model. Dried material was submitted to color and chromatographical assessments. Analyses of obtained essential oil showed the presence of 93 volatile compounds, predominantly β-myrcene, limonene, and β-(E)-caryophyllene, as well as α-humulene. Application of 240 W during VMD and 50 °C during CD gave the highest retention of aroma compounds, amounting to 85 and 76%, respectively, but with huge color changes. Additionally, sensory analysis proved that drying with a microwave power of 240 W provides a product most similar to fresh material.

Can supernatant from immortalized adipose tissue MSC replace cell therapy? An in vitro study in chronic wounds model

Abstract: Mesenchymal stem cells (MSCs) secrete a cocktail of growth factors and cytokines, which could promote tissue regeneration and wound healing. Therefore, in clinical practice, post-culture MSC supernatant treatment could be a more attractive alternative to autologous stem cell transplantation. In this study, we compared the regenerative properties of supernatants harvested from four newly established human adipose tissue mesenchymal stem cell lines (HATMSCs) derived from chronic wound patients or healthy donors. HATMSC supernatants were produced in a serum-free medium under hypoxia and their content was analyzed by a human angiogenesis antibody array. The regenerative effect of HATMSCs supernatants was investigated in an in vitro model of chronic wound, where cells originating from human skin, such as microvascular endothelial cells (HSkMEC.2), keratinocytes (HaCaT), and fibroblasts (MSU-1.1), were cultured in serum-free and oxygen-reduced conditions. The effect of supernatant treatment was evaluated using an MTT assay and light microscopy. In addition, fibroblasts and HATMSCs were labeled with PKH67 and PKH26 dye, respectively, and the effect of supernatant treatment was compared to that obtained when fibroblasts and HATMSCs were co-cultured, using flow cytometry and fluorescent microscopy. A wide panel of angiogenesis-associated cytokines such as angiogenin, growth-regulated oncogene (GRO), interleukin-6 and 8 (IL-6, IL-8), vascular endothelial growth factor (VEGF), insulin growth factor 1 (IGF-1), and matrix metalloproteinase (MMP) were found in all tested HATMSCs supernatants. Moreover, supernatant treatment significantly enhanced the survival of fibroblasts, endothelial cells, and keratinocytes in our chronic wound model in vitro. Importantly, we have shown that in in vitro settings, HATMSC supernatant treatment results in superior fibroblast proliferation than in the case of co-culture with HATMSCs. Our results suggest that therapy based on bioactive factors released by the immortalized atMSC into supernatant has important effect on skin-derived cell proliferation and might preclude the need for a more expensive and difficult cell therapy approach to improve chronic wound healing.

Odour reducing microbial-mineral additive for poultry manure treatment

Abstract: Poultry production systems are associated with emissions of odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), greenhouse gases, and particulate matter. Development of mitigation technologies for these emissions is important. Previous laboratory-scale research on microbial-mineral treatment has shown to be effective for mitigation of NH3, H2S and amines emissions from poultry manure. The aim of this research was to assess the effectiveness of surface application of a microbial-mineral treatment for other important odorants, i.e., phenolics and sulfur-containing VOCs. Microbial-mineral litter additive consisting of 20% (w/w) of bacteria powder (six strains of heterotrophic bacteria) and 80% of mineral carrier (perlite-bentonite) was used at a dose of 500 g∙m-2 (per ~31 kg of manure). Samples of air were collected in two series, 4 and 7 days after application of additives. An odor profile of the poultry manure was determined using simultaneous chemical and sensory analysis. Reduction levels of VOCs determined on Day 4 was between 31% and 83% for mineral adsorbent treatment and in the range of 9% and 96% for microbial-mineral additive, depending on the analyzed compound. Reduction levels on Day 7 were considerably lower than on Day 4, suggesting that the odorous VOCs treatment efficacy is relatively short. There was no significant difference between treatments consisting of microbial-mineral additive and mineral carrier alone.