A relative ability of four industrial samples of phosphorus-free polymers (polyaspartate, PASP; polyepoxysuccinate, PESA; polyacrylic acid sodium salt, PAAS; copolymer of maleic and acrylic acid, MA-AA) and of two phosphonates (aminotris(methylenephosphonic acid), ATMP; 1-hydroxyethane-1,1-bis(phosphonic acid), HEDP) to inhibit calcium carbonate precipitation at a dosage 10 mg•dm -3 is tested in static experiments following the NACE Standard TM0374-2007 and in a dynamic modeоfevaporation plant for Caspian Sea water imitate. The reagent efficiency ranking following NACE Standard gives evidently a preference to phosphonates over polymers: ATMP~HEDP>PESA (400-1,500 Da) ~PASP (1,000-5,000 Da)>PAAS (3,000-5,000 Da) ~MA-AA. At the same time the kinetic tests exhibit the better efficiency of PESA and MA-AA: PESA>MA-AA>PAAS~HEDP>ATMP~PASP. Therefore, a lot of work is still needed to elaborate a system of laboratory tests for antiscalants in order to provide reliable assessment and selection on their way from laboratory to industry.
Funding Acknowledgements Type of funding sources: None. Background. Many patients with COVID-19 suffer from arterial hypertension and have marked variations in blood pressure (BP) during the acute period of infection. The reasons for such changes are poorly understood. Purpose. To assess the relationship between the level of BP and the severity of changes in the main clinical and laboratory parameters in patients with arterial hypertension and with a moderate course of COVID-19 at the stage of the height of the disease. Materials and methods. The study included 86 hospitalized patients with verified coronavirus disease of moderate severity: 46 of them were male, the median age was 65 years. Patients received adequate hypertension therapy for a long time. After hospitalization, treatment was adjusted if necessary. The level of laboratory parameters in the acute period of the disease was determined, including the electrolytes, C-reactive protein (CRP), albumin, ferritin, general blood test, etc. BP measured daily. The relationship between laboratory parameters and BP level was evaluated by nonparametric correlation using the Spearman coefficient and multivariate analysis based on the "generalized nonlinear model". Results. In 67.44% of patients with hypertension, an elevated BP level (>140/90) was observed against the background of moderate COVID-19. There was a significant negative correlation between the levels of CRP and BP throughout the stay in the hospital, the most significant is the 5th day of hospitalization. At the same time, a slightly stronger relationship is observed with diastolic BP (r = -0.4425) than with systolic BP (r = -0.3525). A similar trend is observed in all BP measurements. Besides, a negative correlation was found between potassium levels and BP values. The strongest association of potassium levels is with systolic BP on the day of hospitalization (r = -0.4850) and diastolic pressure on the 1st day of hospitalization (r = -0.3561). Multivariate analysis confirmed independent and reliable "influence" of CRP (p = 0.00018) and potassium (p = 0.03921) as independent predictors of diastolic pressure. Conclusions. Most patients with hypertension and moderate COVID-19 have elevated BP levels. There is a statistically significant negative relationship between the values of BP and levels of CRP and potassium. The obtained data may correspond to the existing hypothesis about the significant role of the kinin–kallikrein system in the pathogenesis of COVID-19.
The search for new sources of regional development is important due to the slowdown in economic growth and the need to shift the emphasis of industrial policy from the macro level to the level of regions and individual companies. In this regard, we consider the participation of companies in reputation ratings as a new source for increasing the investment attractiveness of regions. Additionally, we examine the relationship between corporate and regional ratings: corporate ratings demonstrate a company’s compliance with the sustainable development goals, which, in turn, improves the socio-economic performance of regions. We revealed the positive influence of high corporate ratings on the socio-economic development of regions, opening a new area for interdisciplinary research combining corporate finance and regional economics. On the example of 130 biggest Russian public non-financial companies, we obtained several significant results that allow determining the impact of corporate ratings on the socio-economic situation of regions and corporate financial performance. The ratings include Sustainable development Index of the Russian Union of Industrialists and Entrepreneurs (RUIE), Environmental responsibility rating of the World Wildlife Fund (WWF) Russia, and Corporate social responsibility rating of the Association of Managers of Russia (AMR). The calculations showed that the participation of companies in the ratings of WWF Russia and RUIE positively affects the indicators sustainable development of regions where these companies are located. Simultaneously, the influence of companies’ participation in the rating of WWF Russia is higher than the influence of participation in the RUIE rating. In addition, reputation ratings have a positive impact on the return on assets and market capitalisation of Russian companies. Thus, we proved that participation in corporate ratings leads to an increase in performance. However, the effects of participation in various ratings differ. For example, to increase its conditions and performance, a company should be a leader of the rating of RUIE and just participate in the rating of WWF Russia. The rating of AMR influences the market capitalisation the most. The obtained findings indicate the need for expanding the participation of Russian companies in corporate ratings and enable research in the field of sustainable development of companies.
The work aims to carry out a comparative analysis of the spectral indices of the photoplethysmogram signals and RR-intervals of healthy volunteers, patients with COVID-19, as well as patients with COVID-19 and chronic arterial hypertension of 1-2 degrees. The study included 45 records of pairs of electrocardiogram and photoplethysmogram signals. Each sample included 15 pairs of 20-minute experimental signals. The study revealed an increase in the integrated power of the low-frequency (LF) band over the integrated power of the high-frequency (HF) band in the photoplethysmogram signals in patients with COVID-19, burdened with hypertension. In the signals of the RR-intervals, the largest values of the ratio of the LF to HF indices are associated with patients without cardiovascular diseases. In turn, this may be an indicator of the different effects of viral infection and arterial hypertension on the loops of autonomic control of heart rate and vascular tone.
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