Биология

Traumatic brain injury (TBI) is a major health problem that causes long term neurological deficit in the majority of patients and does not have any clinically proved effective treatment. Transcranial direct current stimulation (tDCS) is an emerging electroceutical therapy suggested for TBI rehabilitation. However, optimal parameters of stimulation and mechanisms of action are not determined due to lack of preclinical studies, impeding its clinical implementation.

This work is devoted to the comparative analysis of the functional state of systemic hemodynamics in Russian and foreign students depending on the localization of the transition zone in the chest leads of ECG during the active orthostatic test. Having assessed physical development, we measured the parameters of arterial pressure and ECG using the module «Electrocardiogram» APK «Valenta». The prevalence of asthenic type of physique in foreign students against the deficiency of physical development determines the vertical position of the heart.

The object of the study was sprouts of durum wheat Triticum durum L. Cultivation was carried out at a temperature of 15 ± 1°C and 20 ± 2°C. To study the influence of the temperature factor on the development of the photosynthetic apparatus, the quantitative content of chlorophyll a, chlorophyll b, and carotenoids was determined. Some varieties, when subjected to a change in the temperature of cultivation, respond with a change in the indices determining their stress tolerance, namely the ratio of chlorophyll a and chlorophyll b, carotenoids and chlorophylls.

The article provides information about the epiphytic lichen flora of the Natural Park “Kumysnaya Polyana” (NP), which is located in Saratov. It is a regional SPNA (Special Protected Natural Area). The researches were conducted in forest communities of NP in 2011–2016. Standard techniques were used in the collection and identification of lichens. An index of species specificity of lichens for forophytes was calculated. An annotated list consists of 37 species and includes the information about their preferential forophytes.

Photodynamic treatment (PDT) causes a significant increase in the permeability of the blood-brain barrier (BBB) in healthy mice. Using different doses of laser radiation (635 nm, 10–40 J/cm2 ) and photosensitizer (5-aminolevulinic acid – 5-ALA, i.v.), we found the optimal PDT for the reversible opening of the BBB, exhibiting brain tissue recovery 3 days after PDT. Further increases in the laser radiation or 5-ALA doses have no amplifying effect on the BBB permeability, but are associated with severe damage of brain tissues.

In this brief communication, the results of the research on the seasonal dynamics of orthopterous insects (Orthoptera) are discussed. The research was performed in the Volga-Kama State Nature Biosphere Reserve. Field sampling and observations were carried out for different biotopes of the nature reserve. The phenological characteristics of 26 background species of the families Tettigonioidea, Tetrigidae, and Acridoidea were revealed.

In the experiments on rats, Evans Blue dye and gold nanorods were injected into the brain parenchyma, followed by visualization with optical coherent tomography and a fluorescent microscopy. The results showed that meningeal lymphatics play an important role in the brain clearing, using markers introduced into the tissues. It has been shown that the deep cervical lymph node is the first anatomical “station” for the outflow of fluid from the brain. The data obtained shed light on the lymphatic mechanisms underlying the drainage and clearing of brain functions.

The anthropogenic pressure on ecosystems may contribute to the spread of antibiotic resistance among bacteria in natural conditions. Due to this, the aim of this work was to study the impact of specific biocides, antibiotics, pesticides and heavy metals on the emergence of rifampicin resistant mutants of Pseudomonas putida. To assess the impact of toxic substances on the emergence of rifampicin-resistant mutants the studied substances and rifampicin in the final concentration of 100 ?g/ml were added into nutrient medium before plating.

This study shows the role of adrenergic mechanisms in the development of fluorescent glioma in rats and the impairment of the blood-brain barrier (BBB) permeability. The results demonstrate that the progression of glioma was accompanied by a gradual increase in the BBB permeability and an increased expression of vascular beta2-adrenoreceptors (B2-AR). The pharmacological blockade of B2-AR reduced the degree of BBB disruption, the migration of cancer cells and increased the survival of animals.

It is known that bacterial alginates are widely used in biomedicine as carriers in the immobilization of cells, enzymes and drugs. Their functional properties depend on their monomeric composition and molecular weight and vary depending on the source and the cultivation conditions. It was established that molasses (waste of sugar beet production) can be used as an effective and cheap source of nutrition for the growth of the bacterium Azotobacter vinelandii strain D-05 and the production of alginate.