Лесные типологии в Российской Федерации

Цель работы – сравнительный анализ основных российских лесных типологий: лесоэкологической Е.В. Алексеева – П.С. Погребняка, фитоценотической В.Н. Сукачева, генетической Б.А. Ивашкевича – Б.П. Колесникова, динамической И.С. Мелехова. Сравнение выполнено по следующим позициям: содержание понятия классификационной единицы (тип условий местопроизрастания, тип леса); особенности выделения границы классификационных единиц; классификационные признаки для определения типа условий местопроизрастания; отличительные черты классификации фитоценозов для установления типа леса; степень учета сукцессионной динамики лесных насаждений и влияния антропогенных факторов; уровень внедрения в практику лесного хозяйства и регионы внедрения. Установлено, что в процессе развития лесных типологий понятие о типе леса изменялось от участка леса, однородного по составу, строению и внешнему облику (однородность в пространстве), в естественных классификациях до представлений о типе леса, с приоритетом однородности по происхождению (генезису), процессам развития и динамике (однородность во времени) в сравнении с однородностью состава и структуры в генетических и динамической типологиях. Приведено географическое распространение лесоэкологических, фитоценотических и генетических классификаций типов леса в Российской Федерации на настоящий момент. Лесоэкологические классификации используются в основном в южных регионах европейской части России и на Северном Кавказе. Лесные типологии, созданные на основе генетического подхода, нашли применение в Западной Сибири, на юге Дальнего Востока и в Восточной Сибири, в некоторых регионах Урала. В остальных субъектах Российской Федерации используются фитоценотические классификации типов леса. Объединение существующих типологий в единую классификацию возможно на основе генетического подхода, т. к. естественные типологии в рамках данного подхода могут являться составной частью генетических классификаций. Решение проблемы объединенного использования в одном регионе разных типологий обеспечит уровень лесоустройства, позволяющий оптимизировать лесопользование и сравнивать полученные данные как для субъектов Российской Федерации, так и для страны в целом. Для цитирования: Фомин В.В., Иванова Н.С., Залесов С.В., Попов А.С., Михайлович А.П. Лесные типологии в Российской Федерации // Изв. вузов. Лесн. журн. 2023. № 6. С. 9–30. https://doi.org/10.37482/0536-1036-2023-6-9-3

Planarians as an In Vivo Experimental Model for the Study of New Radioprotective Substances

Ionising radiation causes the death of the most actively dividing cells, thus leading to depletion of the stem cell pool. Planarians are invertebrate flatworms that are unique in that their stem cells, called neoblasts, constantly replace old, damaged, or dying cells. Amenability to efficient RNAi treatments, the rapid development of clear phenotypes, and sensitivity to ionising radiation, combined with new genomic technologies, make planarians an outstanding tool for the discovery of potential radioprotective agents. In this work, using the well-known antioxidant N-acetylcysteine, planarians are, for the first time, shown to be an excellent model system for the fast and effective screening of novel radioprotective and radio-sensitising substances. In addition, a panel of measurable parameters that can be used for the study of radioprotective effects on this model is suggested

p62-Nrf2-p62 Mitophagy Regulatory Loop as a Target for Preventive Therapy of Neurodegenerative Diseases

Turnover of the mitochondrial pool due to coordinated processes of mitochondrial biogenesis and mitophagy is an important process in maintaining mitochondrial stability. An important role in this process is played by the Nrf2/ARE signaling pathway, which is involved in the regulation of the expression of genes responsible for oxidative stress protection, regulation of mitochondrial biogenesis, and mitophagy. The p62 protein is a multifunctional cytoplasmic protein that functions as a selective mitophagy receptor for the degradation of ubiquitinated substrates. There is evidence that p62 can positively regulate Nrf2 by binding to its negative regulator, Keap1. However, there is also strong evidence that Nrf2 up-regulates p62 expression. Thereby, a regulatory loop is formed between two important signaling pathways, which may be an important target for drugs aimed at treating neurodegeneration. Constitutive activation of p62 in parallel with Nrf2 would most likely result in the activation of mTORC1-mediated signaling pathways that are associated with the development of malignant neoplasms. The purpose of this review is to describe the p62-Nrf2-p62 regulatory loop and to evaluate its role in the regulation of mitophagy under various physiological conditions

Mitogen-like Cerium-Based Nanoparticles Protect <i>Schmidtea mediterranea</i> against Severe Doses of X-rays

Novel radioprotectors are strongly demanded due to their numerous applications in radiobiology and biomedicine, e.g., for facilitating the remedy after cancer radiotherapy. Currently, cerium-containing nanomaterials are regarded as promising inorganic radioprotectors due to their unrivaled antioxidant activity based on their ability to mimic the action of natural redox enzymes like catalase and superoxide dismutase and to neutralize reactive oxygen species (ROS), which are by far the main damaging factors of ionizing radiation. The freshwater planarian flatworms are considered a promising system for testing new radioprotectors, due to the high regenerative potential of these species and an excessive amount of proliferating stem cells (neoblasts) in their bodies. Using planarian Schmidtea mediterranea, we tested CeO2 nanoparticles, well known for their antioxidant activity, along with much less studied CeF3 nanoparticles, for their radioprotective potential. In addition, both CeO2 and CeF3 nanoparticles improve planarian head blastema regeneration after ionizing irradiation by enhancing blastema growth, increasing the number of mitoses and neoblasts’ survival, and modulating the expression of genes responsible for the proliferation and differentiation of neoblasts. The CeO2 nanoparticles’ action stems directly from their redox activity as ROS scavengers, while the CeF3 nanoparticles’ action is mediated by overexpression of “wound-induced genes” and neoblast- and stem cell-regulating genes

Effect of <i>h</i>-BN Support on Photoluminescence of ZnO Nanoparticles: Experimental and Theoretical Insight

Herein we report a simple and easily scalable method for fabricating ZnO/h-BN composites with tunable photoluminescence (PL) characteristics. The h-BN support significantly enhances the ultraviolet (UV) emission of ZnO nanoparticles (NPs), which is explained by the ZnO/h-BN interaction and the change in the electronic structure of the ZnO surface. When h-BN NPs are replaced with h-BN microparticles, the PL in the UV region increases, which is accompanied by a decrease in visible light emission. The dependence of the PL properties of ZnO NPs on the thickness of h-BN carriers, observed for the first time, is explained by a change in the dielectric constant of the support. A quantum chemical analysis of the influence of the h-BN thickness on the electron density redistribution at the wZnO/h-BN interface and on the optical properties of the wZnO/h-BN composites was carried out. Density functional theory (DFT) calculations show the appearance of hybridization at the h-BN/wZnO interface and an increase in the intensity of absorption peaks with an increase in the number of h-BN layers. The obtained results open new possibilities for controlling the properties of ZnO/h-BN heterostructures for various optical applications

Development of a 0.15 μm GaAs pHEMT Process Design Kit for Low-Noise Applications

This work presents a process design kit (PDK) for a 0.15 μm GaAs pHEMT process for low-noise MMIC applications developed for AWR Microwave Office (MWO). A complete set of basic elements is proposed, such as TaN thin film resistors and mesa-resistors, capacitors, inductors, and transistors. The developed PDK can be used in technology transfer or education

Brain Protection by Methylene Blue and Its Derivative, Azur B, via Activation of the Nrf2/ARE Pathway in Cisplatin-Induced Cognitive Impairment

Cisplatin is a cytotoxic chemotherapeutic drug that leads to DNA damage and is used in the treatment of various types of tumors. However, cisplatin has several serious adverse effects, such as deterioration in cognitive ability. The aim of our work was to study neuroprotectors capable of preventing cisplatin-induced neurotoxicity. Methylene blue (MB) and AzurB (AzB) are able to neutralize the neurotoxicity caused by cisplatin by protecting nerve cells as a result of the activation of the Ntf2 signaling pathway. We have shown that cisplatin impairs learning in the Morris water maze. This is due to an increase in the amount of mtDNA damage, a decrease in the expression of most antioxidant genes, the main determinant of the induction of which is the Nrf2/ARE signaling pathway, and genes involved in mitophagy regulation in the cortex. The expression of genes involved in long-term potentiation was suppressed in the hippocampus of cisplatin-injected mice. MB in most cases prevented cisplatin-induced impairment of learning and decrease of gene expression in the cortex. AzB prevented the cisplatin-induced decrease of genes in the hippocampus. Also, cisplatin induced disbalance in the gut microbiome, decreased levels of Actinotalea and Prevotella, and increased levels of Streptococcus and Veillonella. MB and AzB also prevented cisplatin-induced changes in the bacterial composition of the gut microbiome

PVP-stabilized tungsten oxide nanoparticles: pH sensitive anti-cancer platform with high cytotoxicity

Photochromic tungsten oxide (WO3) nanoparticles stabilized by polyvinylpyrrolidone (PVP) were synthesized to evaluate their potential for biomedical applications. PVP-stabilized tungsten oxide nanoparticles demonstrated a highly selective cytotoxic effect on normal and cancer cells in vitro. WO3 nanoparticles were found to induce substantial cell death in osteosarcoma cells (MNNG/HOS cell line) with a half-maximal inhibitory concentration (IC50) of 5 mg/mL, while producing no, or only minor, toxicity in healthy human mesenchymal stem cells (hMSc). WO3 nanoparticles induced intracellular oxidative stress, which led to apoptosis type cell death. The selective anti-cancer effects of WO3 nanoparticles are due to the pH sensitivity of tungsten oxide and its capability of reactive oxygen species (ROS) generation, which is expressed in the modulation of genes involved in reactive oxygen species metabolism, mitochondrial dysfunction, and apoptosis