Antibodies to the N-Terminal Domain of Angiotensin-Converting Enzyme (ACE2) That Block Its Interaction with SARS-CoV-2 S Protein

Doklady Biochemistry and Biophysics - SARS-CoV-2 is a new coronavirus that is the cause of COVID-19 pandemic. To enter the cell, the virus interacts via its surface S protein with...     

Prophylaxis of aging: Contours of a new science

The subjects of analysis are the fundamental scientific and applied aspects of a new sphre of biomedicine, i.e., prophylaxis of aging. It is shown that it presupposes a principally new class of medical technologies that enable physcians to set and accomplish the task of exceeding the limits of the average species life expectancy of the human.     

Rapid identification, virulence analysis and resistance profiling of Staphylococcus aureus by gene segment-based DNA microarrays: application to blood culture post-processing

Up to now, blood culturing systems are the method of choice to diagnose bacteremia. However, definitive pathogen identification from positive blood cultures is a time-consuming procedure, requiring subculture and biochemical analysis. We developed a microarray for the identification of Staphylococcus aureus comprising PCR generated gene-segments, which can reduce the blood culture post-processing time to a single day. Moreover, it allows concomitant identification of virulence factors and antibiotic resistance determinants directly from positive blood cultures without previous amplification by PCR. The assay unambiguously identifies most of the important virulence genes such as tsst-1, sea, seb, eta and antibiotic resistance genes such as mecA, aacA-aphD, blaZ and ermA. To obtain positive signals, 20 ng of purified genomic S. aureus DNA or 2 microg of total DNA extracted from blood culture was required. The microarray specifically distinguished S. aureus from gram-negative bacteria as well as from closely related coagulase negative staphylococci (CoNS). The microarray-based identification of S. aureus can be accomplished on the same day blood cultures become positive in the Bactec. The results of our study demonstrate the feasibility of microarray-based systems for the direct identification and characterization of bacteria from cultured clinical specimens.     

Some properties of particles of egg-yolk phosphatidylcholine and cholesterol

Some physicochemical properties of particles of phosphatidylcholine and cholesterol, produced by ultrasonication of their aqueous dispersions in varying proportions and concentrations were investigated. Cholesterol altered the micellar characteristics according to its proportion. S_{20, w} values increased incrementally from 2.53 for phosphatidylcholine alone to 15.65 for particles containing the highest proportion and concentration of solubilized cholesterol (0.28 g/100 ml of each lipid). Similarly, particle weight increased from 3 × 10⁶ to 7.12 × 10⁷, axial ratios from 3.9 (discs) and 3.3 (rods) to 28.0 (discs) and 13.0 (rods), the viscosity shape factor, ν, from 3.9 to 20.7, water of hydration decreased from 0.26 g H₂O/g lipid to 0.22 g H₂O/g lipid and the number of monomers within each particle ranged from 4000 to 84,000.     

A Decrease in the Rate of Human Aging in the 20th Century and its Potential Causes

Biophysics - Abstract—Since the middle of the 20th century, there has been a decrease in the rate of aging for developed countries with a maximum for ages 60–85 years. The calculation...     

Comparative Analysis of Methods for Estimating the Rate of Population Aging

Biophysics - The essence of aging is a decline in total vitality with age, being basic personal characteristics of human potential. Viability ( $${v}$$ ) is defined as the probability of surviving...