The Crosstalk between SARS-CoV-2 Infection and the RAA System in Essential Hypertension—Analyses Using Systems Approach

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), responsible for the coronavirus disease of 2019 (COVID-19) pandemic, has affected and continues to affect millions of people across the world. Patients with essential arterial hypertension and renal complications are at particular risk of the fatal course of this infection. In our study, we have modeled the selected processes in a patient with essential hypertension and chronic kidney disease (CKD) suffering from COVID-19, emphasizing the function of the renin-angiotensin-aldosterone (RAA) system. The model has been built in the language of Petri nets theory. Using the systems approach, we have analyzed how COVID-19 may affect the studied organism, and we have checked whether the administration of selected anti-hypertensive drugs (angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs)) may impact the severity of the infection. Besides, we have assessed whether these drugs effectively lower blood pressure in the case of SARS-CoV-2 infection affecting essential hypertensive patients. Our research has shown that neither the ACEIs nor the ARBs worsens the course infection. However, when assessing the treatment of hypertension in the active SARS-CoV-2 infection, we have observed that ARBs might not effectively reduce blood pressure; they may even have the slightly opposite effect. On the other hand, we have confirmed the effectiveness of arterial hypertension treatment in patients receiving ACEIs. Moreover, we have found that the simultaneous use of ARBs and ACEIs averages the effects of taking both drugs, thus leading to only a slight decrease in blood pressure. We are a way from suggesting that ARBs in all hypertensive patients with COVID-19 are ineffective, but we have shown that research in this area should still be continued.     

Heterografted PEO-PnBA brush copolymers

A series of P[(HEMA-TMS)-co-PEOMA] graft copolymers with different amounts of incorporated macromonomer grafts were prepared by copolymerization of a PEO macromonomer (PEOMA, MW_av=1100 g/mol, DP_PEO=23) with 2-(trimethylsilyloxy)ethyl methacrylate (HEMA-TMS) using various initial ratios of the comonomers via atom transfer radical polymerization. After transformation of the HEMA-TMS units to 2-(2-bromopropionyloxy)ethyl methacrylate (BPEM), the resulting P(BPEM-co-PEOMA) copolymers were used as macroinitiators for the controlled polymerization of nBA in a ‘grafting from’ reaction. The resulting densely heterografted brush copolymers with a uniform length of PEO grafts (DP_PEO=23) and a range of lengths for the PnBA side chains (DP_PnBA=15-60) depending solely on the reaction time. Analysis of the bulk properties showed that the specific architecture of the copolymers suppresses crystallization of the PEO, and consequently leads to amorphous, homogeneous materials.     

Sintering of fat crystal networks in oil during post-crystallization processes

Several foods contain semi-solid fats that consist of solid crystals dispersed in a liquid oil. In oil-continuous margarine, butter, and chocolate, fat crystals determine properties such as consistency, stability against oiling-out, and emulsion stability. Trends toward foods with less fat and/or less saturated fat create a need for understanding and controlling the properties of fat crystal dispersions. Fat crystals form a network in oil due to mutual adhesion. One source of strong adhesion is formation of solid bridges (sintering), which has been studied in this work through sedimentation and rheological experiments. Results indicate that sintering may be created by crystallization of a fat phase with a melting point between that of the oil and the crystal. Generally speaking, β′ crystals were sintered by β′ fat bridges, favored by rapid cooling, and β crystals by β fat bridges, favored by slow cooling. The existence of the same polymorphic form of the crystal and bridge indicated that solid bridges, rather than bridges formed by small crystal nuclei, were formed. A maximum in sintering ability for an optimal sintering fat concentration occurred due to competition between bridge formation and other crystallization processes. Some emulsifiers influenced the sintering process. For example, monooolein made it more pronounced, while technical lecithin had the opposite effect.     

Application of ion exchangers for the purification of galvanic wastewater from heavy metals

The aim of the present study was to investigate the sorption and physicochemical properties of the chelating ion exchangers with bis(2-pyridylmethyl)amine and aminophosphonic functional groups before and after the sorption of galvanic wastewaters. The study was carried out on the Dowex M4195, Lewatit^® MonoPlus TP 220, Purolite S 940 and Purolite S 950 ion exchangers. For the practical use of the studied ion exchangers in the process of wastewater purification, the sorption capacity of the above-mentioned ions was determined depending on the phase contact time and sorption process in the whole volume of the beads.     

Analysis of utilisation of renewable energies as heat sources for heat pumps in building sector in Poland

In this paper the emphasis is put on identification the problem how different renewable sources can be effectively used as heat sources for heat pumps in Poland. Main data of: ambient air, solar radiation, soil, ground and surface water are presented. Recommendations for heating systems with a heat pump are given.     

The influence of temperature on interactions and structures in semisolid fats

The strength of fat crystal networks in oil increases at elevated temperatures due to increased adhesion between partially melted crystal surfaces. This strong adhesion, in combination with low oil viscosity (weak hydrodynamic force), is the reason for extensive fat crystal flocculation at elevated temperatures. The crystal flocs likely sinter, dramatically increasing the thickness of semisolid fats. Crystal growth also occurs. The described temperature-induced crystal changes may be suppressed by a controlled sintering process at low temperature. Emulsifiers, such as sorbitan esters of tristearate, also suppress the temperature-induced changes. Fat crystals can be used as thickeners or gelling agents for triglyceride oils in various applications. It is possible to direct the thickening to a specific temperature, and to control the degree of thickening, by choice of fat phase composition, additives, tempering conditions, and crystallization technique.     

A necessary condition of viability for fractional differential equations with initialization

In this paper, viability results for nonlinear fractional differential equations with the Riemann-Liouville derivative are proved. We give a necessary condition for fractional viability of a locally closed set with respect to a nonlinear function.     

Validation of spoken language resources: an overview of basic aspects

Spoken language resources (SLRs) are essential for both research and application development. In this article we clarify the concept of SLR validation. We define validation and how it differs from evaluation. Further, relevant principles of SLR validation are outlined. We argue that the best way to validate SLRs is to implement validation throughout SLR production and have it carried out by an external and experienced institute. We address which tasks should be carried out by the validation institute, and which not. Further, we list the basic issues that validation criteria for SLR should address. A standard validation protocol is shown, illustrating how validation can prove its value throughout the production phase in terms of pre-validation, full validation and pre-release validation.

CoMFA methodology in structure-activity analysis of hexahydro- and octahydropyrido[1,2-c]pyrimidine derivatives based on affinity towards 5-HT1A, 5-HT2A and alpha1-adrenergic receptors

Structural features of the pyrido[1,2-c]pyrimidine derivatives with arylpiperazine moiety and their affinities towards 5-HT1A, 5-HT2A and alpha1-adrenergic receptors were analyzed using the CoMFA procedure. On the basis of 3D-QSAR models for the 5-HT2A and alpha1-adrenergic receptors, four compounds with expected better affinity/selectivity were proposed and synthesized. The affinities obtained confirm experimentally the usefulness of CoMFA models. Our results suggest that active conformations adopted by the studied molecules when interacting with the receptors are neutral instead of the protonated ones.     

Motivating developer performance to improve project outcomes in a high maturity organization

In this paper we discuss the impact software developer performance has on project outcomes. Project performance remains unreliable in the software industry with many compromised software systems reported in the press. We investigate the impact that developer performance has on aspects of project success and explore how developer performance is motivated. We present interview, focus group and questionnaire data collected from a team of developers working in a software organization that has been assessed at CMM level 5. Our main findings are that developers value technical skills in their colleagues, but appreciate these especially when supplemented with good human skills. Software developers with a proactive, flexible, adaptable approach who are prepared to share knowledge and follow good practice are said to be the best developers. Motivators for these developers are pay and benefits, recognition and opportunities for achievement in their work. Overall, we found that technical competence, interpersonal skills and adherence to good practices are thought to have the biggest impact on software project success.