75-Year dynamics of the Black Sea phytoplankton in association with eutrophication and climate change.

Based on a database containing species records obtained from 1948 to 2022 and a hydrochemical database, long-term changes in the biomass and taxonomic structure of phytoplankton in the deep-sea basin of the Black Sea were analysed in the stratified period from April to October. Over 75 years, a significant increase in concentration of nitrate, a weak increase in phosphate and a strong decrease in dissolved silicate were observed in the nutricline. The biomass of diatoms and total phytoplankton increased several times during the peak of eutrophication in 1991-1993, then decreased by the 2000s and has again shown an increasing trend in the last 15 years.

A Method for Treating Significant Conformational Changes in Alchemical Free Energy Simulations of Protein-Ligand Binding.

Relative binding free energy (RBFE) simulation is a rigorous approach to the calculation of quantitatively accurate binding free energy values for protein-ligand binding in which a reference binder is gradually converted to a target binder through alchemical transformation during the simulation. The success of such simulations relies on being able to accurately sample the correct conformational phase space for each alchemical state; however, this becomes a challenge when a significant conformation change occurs between the reference and target binder-receptor complexes. Increasing the simulation time and using enhanced sampling methods can be helpful, but effects can be limited, especially when the free energy barrier between conformations is high or when the correct target complex conformation is difficult to find and maintain.

[On the issue of optimizing protein and energy supply for patients with acute cerebrovascular accident].

Objective: To study the severity of systemic metabolic dysfunction in various types of stroke and determine the parameters of optimal energy and protein supply for this category of patients in the presence of severe neurological deficit (National Institutes of Health Stroke Scale - NIHSS score of 15 points or more) during different periods of the disease.

Material And Methods: The retrospective study included 512 patients with acute cerebrovascular accident (ACVA) who received nutritional support (NS) for 10 days or more: 367 (71.7%) people with ischemic stroke (IS) and 145 (28.

Aging and physiological barriers: mechanisms of barrier integrity changes and implications for age-related diseases.

The phenomenon of compartmentalization is one of the key traits of life. Biological membranes and histohematic barriers protect the internal environment of the cell and organism from endogenous and exogenous impacts. It is known that the integrity of these barriers decreases with age due to the loss of homeostasis, including age-related gene expression profile changes and the abnormal folding/assembly, crosslinking, and cleavage of barrier-forming macromolecules in addition to morphological changes in cells and tissues.

Where in the tissues of Danio rerio is more H2O2 produced during acute hypoxia?

The lack of oxygen (O2) causes changes in the cell functioning. Modeling hypoxic conditions in vitro is challenging given that different cell types exhibit different sensitivities to tissue O2 levels. We present an effective in vivo platform for assessing various tissue and organ parameters in Danio rerio larvae under acute hypoxic conditions.