ANALYSING THE INFLUENCE OF THE REINFORCED CONCRETE CHIMNEY GEOMETRY CHANGES ON THE STRESSES IN THE CHIMNEY SHAFT

Analysis of the reinforced concrete chimney geometry changes and their influence on the stresses in the chimney mantle was made. All the changes were introduced to a model chimney and compared. Relations between the stresses in the mantle of the chimney and the deformations determined by the change of the chimney's vertical axis geometry were investigated. The vertical axis of chimney was described by linear function (corresponding to the real rotation of the chimney together with the foundation), and by parabolic function (corresponding to the real dislocation of the chimney under the influence of the horizontal forces - wind). The positive stress pattern in the concrete as well as the negative stress pattern in the reinforcing steel have been presented. The two cases were compared. Analysis of the stress changes in the chimney mantle depending on the modification in the thickness of the mantle (the thickness of the chimney mantle was altered in the linear or the abrupt way) was carried out. The relation between the stresses and the chimney's diameter change from the bottom to the top of the chimney was investigated. All the analyses were conducted by means of a specially developed computer program created in Mathematica environment. The program makes it also possible to control calculations and to visualize the results of the calculations at every stage of the calculation process

Expression of adiponectin receptors 1 and 2 in the ovary and concentration of plasma adiponectin during the oestrous cycle of the pig

The aim of this study was to compare the expression levels of adiponectin receptor 1 and adiponectin receptor 2 mRNAs and proteins in porcine ovaries during four stages (days 2 to 3, 10 to 12, 14 to 16, 17 to 19) of the oestrous cycle and to measure adiponectin plasma concentrations during the same phases of the cycle. Higher mRNA expression of adiponectin receptor 1 was detected in porcine granulosa cells than in corpora lutea and theca cells (P < 0.01). In contrast, higher gene expression of adiponectin receptor 2 occurred in newly developed and mature corpora lutea (P < 0.01). The adiponectin receptor 1 protein content was the highest in corpora lutea isolated on days 2 to 3 of the cycle and was the lowest in theca interna cells (P < 0.01). The profile of adiponectin receptor 2 protein was similar to that of adiponectin receptor 1. Adiponectin plasma concentrations were significantly higher throughout the luteal phase than in the follicular phase (P < 0.01). In conclusion, the presence of adiponectin receptor 1 and adiponectin receptor 2 mRNAs and proteins in the porcine ovary suggests that adiponectin may directly affect ovarian functions through its own specific receptors. The expression of both receptors and adiponectin plasma concentration were dependent on hormonal status related to the stage of the cycle

High pressure induces superoxide production in isolated arteries viaprotein kinase C-dependent activation of NAD(P)H oxidase

Background - Oxidative stress seems to be present in all forms of hypertension. Thus, we tested the hypothesis that high intraluminal pressure (P-i) itself, by activating vascular oxidases, elicits increased superoxide (O-2(.-)) production interfering with flow-induced dilation. Methods and Results - Isolated, cannulated rat femoral arterial branches were exposed in vitro ( for 30 minutes) to normal P-i (80 mm Hg) or high P-i (160 mm Hg). High P-i significantly increased vascular O-2(.-) production ( as measured by lucigenin chemiluminescence and ethidium bromide fluorescence) and impaired endothelium-dependent dilations to flow; these effects could be reversed by superoxide dismutase. Administration of the NAD(P)H oxidase inhibitor diphenyleneiodonium, apocynin, the protein kinase C (PKC) inhibitor chelerythrine or staurosporin or the removal of extracellular Ca2+ during high P-i treatment prevented the increases in O-2(.-) production, whereas administration of losartan or captopril had no effect. High P-i resulted in significant increases in intracellular Ca2+ ([Ca2+](i)) in the vascular wall ( fura 2 fluorescence) and phosphorylation of PKCalpha ( Western blotting). The PKC activator phorbol myristate acetate significantly increased vascular O-2(.-) production, which was inhibited by superoxide dismutase, diphenyleneiodonium, chelerythrine, or removal of extracellular Ca2+. Both high P-i and phorbol myristate acetate increased the phosphorylation of the NAD( P) H oxidase subunit p47(phox). Conclusion - High P-i itself elicits arterial O-2(.-) production, most likely by PKC-dependent activation of NAD( P) H oxidase, thus providing a potential explanation for the presence of oxidative stress and endothelial dysfunction in various forms of hypertension and the vasculoprotective effect of antihypertensive agents of different mechanisms of action

A hunter-gatherer-farmer population model: Lie symmetries, exact solutions and their interpretation

The Lie symmetry classification of the known three-component reaction-diffusion system modelling the spread of an initially localized population of farmers into a region occupied by hunter-gatherers is derived. The Lie symmetries obtained for reducing the system in question to systems of ODEs and constructing exact solutions are applied. Several exact solutions of traveling front type are found, their properties are identified and biological interpretation is discussed

HSV-1 glycoprotein endocytosis

Herpes simplex virus-1 (HSV-1) is a large enveloped DNA virus that belongs to the family of Herpesviridae. It has been recently shown that the cytoplasmic membranes that wrap the newly assembled capsids are endocytic compartments derived from the plasma membrane. Here, we show that dynamin-dependent endocytosis plays a major role in this process. Dominant-negative dynamin and clathrin adaptor AP180 significantly decrease virus production. Moreover, inhibitors targeting dynamin and clathrin lead to a decreased transport of glycoproteins to cytoplasmic capsids, confirming that glycoproteins are delivered to assembly sites via endocytosis. We also show that certain combinations of glycoproteins colocalize with each other and with the components of clathrin-dependent and -independent endocytosis pathways. Importantly, we demonstrate that the uptake of neutralizing antibodies that bind to glycoproteins when they become exposed on the cell surface during virus particle assembly leads to the production of non-infectious HSV-1. Our results demonstrate that transport of viral glycoproteins to the plasma membrane prior to endocytosis is the major route by which these proteins are localized to the cytoplasmic virus assembly compartments. This highlights the importance of endocytosis as a major protein-sorting event during HSV-1 envelopment.This work was supported by grants from the Leverhulme Trust (grant RPG‐2012‐793), the Royal Society (University Research Fellowship UF090010), the Engineering and Physical Sciences Research Council, UK (grant EP/H018301/1, EP/L015889/1) and by the Medical Research Council (grant MR/K015850/1)

During the COVID-19 Pandemic, Lung Specialists of the World Implore You: Inhale Only Clean Air

Recent social media and lay news report that nicotine may help protect from COVID-19. However, lung specialists of the American Thoracic Society and California Thoracic Society recommend that you inhale only clean air. Research shows that exposure to smoke, vapors, and air pollution all contribute to worse outcomes in COVID-19 infection. This fact sheet summarizes some of the common public questions addressed to lung healthcare professionals

Effect of accelerated electron beam on mechanical properties of human cortical bone: influence of different processing methods

Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks. Accelerated EB, in contrast to more often used gamma photons, is a form of ionizing radiation that is characterized by lower penetration, however it is more effective in producing ionisation and to reach the same level of sterility, the exposition time of irradiated product is shorter. There are several factors, including dose and temperature of irradiation, processing conditions, as well as source of irradiation that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect e-beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors, aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as e-beam irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress–strain curves examined by univariate analysis are described. Based on multivariate analysis, including all groups, it was found that temperature of e-beam irradiation and defatting had no consistent significant effect on evaluated mechanical parameters of compact bone rings. In contrast, irradiation with both doses significantly decreased the ultimate strain and its derivative toughness, while not affecting the ultimate stress (bone strength). As no deterioration of mechanical properties was observed in the elastic region, the reduction of the energy absorption capacity of irradiated bone rings apparently resulted from changes generated by irradiation within the plastic strain region