Amino acid metabolism is significantly altered at the time of admission in hospital for severe COVID-19 patients: findings from longitudinal targeted metabolomics analysis

The heterogeneity in severity and outcome of COVID-19 cases points out the urgent need for early molecular characterization of patients followed by risk-stratified care. The main objective of this study was to evaluate the fluctuations of serum metabolomic profiles of COVID-19 patients with severe illness during the different disease stages in a longitudinal manner. We demonstrate a distinct metabolomic signature in serum samples of 32 hospitalized patients at the acute phase compared to the recovery period, suggesting the tryptophan (tryptophan, kynurenine, and 3-hydroxy-DL-kynurenine) and arginine (citrulline and ornithine) metabolism as contributing pathways in the immune response to SARS-CoV-2 with a potential link to the clinical severity of the disease. In addition, we suggest that glutamine deprivation may further result in inhibited M2 macrophage polarization as a complementary process, and highlight the contribution of phenylalanine and tyrosine in the molecular mechanisms underlying the severe course of the infection. In conclusion, our results provide several functional metabolic markers for disease progression and severe outcome with potential clinical application. IMPORTANCE Although the host defense mechanisms against SARS-CoV-2 infection are still poorly described, they are of central importance in shaping the course of the disease and the possible outcome. Metabolomic profiling may complement the lacking knowledge of the molecular mechanisms underlying clinical manifestations and pathogenesis of COVID-19. Moreover, early identification of metabolomics-based biomarker signatures is proved to serve as an effective approach for the prediction of disease outcome. Here we provide the list of metabolites describing the severe, acute phase of the infection and bring the evidence of crucial metabolic pathways linked to aggressive immune responses. Finally, we suggest metabolomic phenotyping as a promising method for developing personalized care strategies in COVID-19 patients.publishersversionPeer reviewe

Investigating the Potential of Nuclear Energy in Achieving a Carbon-Free Energy Future

This scientific paper discusses the importance of reducing greenhouse gas emissions to mitigate the effects of climate change. The proposed strategy is to reach net-zero emissions by transitioning to electric systems powered by low-carbon sources such as wind, solar, hydroelectric power, and nuclear energy. However, the paper also highlights the challenges of this transition, including high costs and lack of infrastructure. The paper emphasizes the need for continued research and investment in renewable energy technology and infrastructure to overcome these challenges and achieve a sustainable energy system. Additionally, the use of nuclear energy raises concerns, such as nuclear waste and proliferation, and should be considered with its benefits and drawbacks. The study assesses the feasibility of nuclear energy development in Latvia, a country in Northern Europe, and finds that Latvia is a suitable location for nuclear power facilities due to potential energy independence, low-carbon energy production, reliability, and economic benefits. The study also discusses methods of calculating electricity generation and consumption, such as measuring MWh produced by power plants, and balancing supply and demand within the country. Furthermore, the study assesses the safety of nuclear reactors, generated waste, and options for nuclear waste recycling. The transition to a carbon-free energy system is ongoing and complex, requiring multiple strategies to accelerate the transition. While the paper proposes that nuclear energy could be a practical means of supporting and backing up electricity generated by renewables, it should be noted that there are still challenges to be addressed. Some of the results presented in the paper are still based on studies, and the post-treatment of waste needs to be further clarified

The Baltic States’ Move toward a Sustainable Energy Future

In respect to CO2 emissions, the post-Soviet states are a scientifically interesting object of research, as each of the countries has developed via different paths since reclaiming independence from the Soviet Union. Given that each country has a different approach to the use of fossil resources, it is essential to assess their input to global carbon footprint individually. Such assessment then allows to find certain actions in the development of legislation and to apply focused techniques to reduce carbon emissions. The aim of this study was to evaluate the fossil CO2 emissions produced in the Baltic States from 1991 onward, describing challenges relating to sustainability and socio-economic, scientific, and integrated approaches to sustainable development, including clean and efficient use of energy, and thus addressing climate challenges. This paper reports on data on CO2 emissions in the Baltic States. The results show that the transition of the Baltic States from the specificities of the Soviet Union’s economy to an economy integrated into global markets has led to a significant reduction in CO2 emissions. However, the development and implementation of national policies for sustainable development are still crucial for mitigation of the climate crisis. Further actions must include the implementation and monitoring of policies for sustainable development, changing of the consumption and production patterns, education and awareness of sustainability, and adaptation to global climate change, while also addressing sustainability challenges

Ciparu elektronika un datoru arhitektūra: laboratorijas darbi un metodiskie norādījumi

Grāmata paredzēta studentiem, kas apgūst bakalauru un profesionālo bakalauru studiju programmas: “Transporta datorvadības, informācijas un elektroniskās sistēmas” un “Transporta elektronika un telemātika”. Metodiskajos norādījumos iekļauti septiņi laboratorijas darbi

Testing of Energy-Efficient Building Envelope Materials in Natural Conditions

The publication presents an ongoing project which aims, by using multi-physical modelling method, to forecast the influence of different building envelope materials on the energy efficiency and the indoor air quality (IAQ). In this project, five identical experimental constructions with different composite building materials of external walls will be created (the indoor area 9 m2, the height of ceiling 3 m). All external wall constructions (U=0.16 W/(m2K)) will have ventilated façades. Five different insulated materials will be used: aerated concrete, ceramic, lightweight construction, wooden constructions, and an innovative composite building material developed in the course of the project. In all the experimental constructions it is planned to ensure air exchange of 0.6 h-1 and indoor air temperature corresponding to category A (CR 1752:2002). The collected energy efficiency and IAQ parameters will be used to verify corresponding multi-physical models. The monitoring will continue for a whole year, to evaluate and analyze the influence of different outdoor parameters in the natural meteorological conditions for Riga, Latvia, that correspond to a cold maritime climate

Charcoal Production in a Continuous Operation Retort. Experimental Data Processing

Charcoal industry has recently regained its spotlight, along with other renewable resources, as one of the tools for Climate Change mitigation, rather than the ill repute as a cause of deforestation. In this paper a study with an experimental evaluation of a charcoal production technology is carried out in an industrial facility. The investigated technology is a state-of-the-art continuous operation automated retort which comprises a monitoring system continuously registering process characteristic temperatures. The raw material, biomass, passes through three different stages in the retort - biomass heating and drying, biomass carbonization, and charcoal cooling. These process sections are described and analyzed according to the relevant temperatures. The obtained data is processed using Statgraphics Centurion Statistical data analysis too. This study draws attention to the importance of scientific approach to charcoal production with optimized process parameters directing the charcoal industry towards an increasingly sustainable production

The Prospects of Clay Minerals from the Baltic States for Industrial-Scale Carbon Capture: A Review

Carbon capture is among the most sustainable strategies to limit carbon dioxide emissions, which account for a large share of human impact on climate change and ecosystem destruction. This growing threat calls for novel solutions to reduce emissions on an industrial level. Carbon capture by amorphous solids is among the most reasonable options as it requires less energy when compared to other techniques and has comparatively lower development and maintenance costs. In this respect, the method of carbon dioxide adsorption by solids can be used in the long-term and on an industrial scale. Furthermore, certain sorbents are reusable, which makes their use for carbon capture economically justified and acquisition of natural resources full and sustainable. Clay minerals, which are a universally available and versatile material, are amidst such sorbents. These materials are capable of interlayer and surface adsorption of carbon dioxide. In addition, their modification allows to improve carbon dioxide adsorption capabilities even more. The aim of the review is to discuss the prospective of the most widely available clay minerals in the Baltic States for large-scale carbon dioxide emission reduction and to suggest suitable approaches for clay modification to improve carbon dioxide adsorption capacity

The Prospects of Clay Minerals from the Baltic States for Industrial-Scale Carbon Capture: A Review

Carbon capture is among the most sustainable strategies to limit carbon dioxide emissions, which account for a large share of human impact on climate change and ecosystem destruction. This growing threat calls for novel solutions to reduce emissions on an industrial level. Carbon capture by amorphous solids is among the most reasonable options as it requires less energy when compared to other techniques and has comparatively lower development and maintenance costs. In this respect, the method of carbon dioxide adsorption by solids can be used in the long-term and on an industrial scale. Furthermore, certain sorbents are reusable, which makes their use for carbon capture economically justified and acquisition of natural resources full and sustainable. Clay minerals, which are a universally available and versatile material, are amidst such sorbents. These materials are capable of interlayer and surface adsorption of carbon dioxide. In addition, their modification allows to improve carbon dioxide adsorption capabilities even more. The aim of the review is to discuss the prospective of the most widely available clay minerals in the Baltic States for large-scale carbon dioxide emission reduction and to suggest suitable approaches for clay modification to improve carbon dioxide adsorption capacity