Changes of photosynthesis and carbon metabolism in Typha angustifolia L grown in conditions of nitrate nitrogen overload

Nitrates may induce alterations in NO-signaling system and change photosynthesisin plants. Significant reduction of 14CO2 fixation was noted at concentration of 3.96mM NaNO3 in an aquatic macrophyte (Typha angustifolia L.). Assimilation of 14CO2 seven days after the introduction of nitrates did not differ between control and experimental samples. There were changes in distribution of 14C among products of 4CO2 fixation 4 h after NaNO3 addition, resulting in increased sugar radioactivity in experimental plants. It was suggested that the observed changes may have regulatory importance

Physicomechanical properties of the extracellular matrix of a demineralized bone

The article describes the results of a study of physicomechanical properties of a demineralized bone matrix of human cancellous and compact bones. A demineralized cancellous bone was shown to have the best characteristics of a porous system for colonization of matrices by cells. The ultimate stress and elasticity modulus of samples of demineralized femoral heads isolated in primary hip replacement was demonstrated to vary in wide ranges. The elasticity modulus ranged from 50 to 250 MPa, and the tensile strength varied from 1.1 to 5.5 MPa. Microhardness measurements by the recovered indentation method were not possible because of the viscoelastic properties of a bone material. To study the piezoelectric properties of samples, a measuring system was developed that comprised a measuring chamber with contact electrodes, a system for controlled sample loading, an amplifier-converter unit, and signal recording and processing software. The measurement results were used to determine the dependence of the signal amplitude on the dynamic deformation characteristics. The findings are discussed in terms of the relationship between the mechanical and electrical properties and the structure of the organic bone component

Physicomechanical properties of the extracellular matrix of a demineralized bone

The article describes the results of a study of physicomechanical properties of a demineralized bone matrix of human cancellous and compact bones. A demineralized cancellous bone was shown to have the best characteristics of a porous system for colonization of matrices by cells. The ultimate stress and elasticity modulus of samples of demineralized femoral heads isolated in primary hip replacement was demonstrated to vary in wide ranges. The elasticity modulus ranged from 50 to 250 MPa, and the tensile strength varied from 1.1 to 5.5 MPa. Microhardness measurements by the recovered indentation method were not possible because of the viscoelastic properties of a bone material. To study the piezoelectric properties of samples, a measuring system was developed that comprised a measuring chamber with contact electrodes, a system for controlled sample loading, an amplifier-converter unit, and signal recording and processing software. The measurement results were used to determine the dependence of the signal amplitude on the dynamic deformation characteristics. The findings are discussed in terms of the relationship between the mechanical and electrical properties and the structure of the organic bone component

Effect of physical activity on structural asymmetry of mouse hippocampus

The relevance of studies of adult neurogenesis is evident in connection with the potential use of these new neurons to replace neurons lost in the process of life. Despite considerable efforts, little is known about the fnal fate of these cells, the functional signifcance of their connections and the regulation of their development. It is known that physical activity signifcantly increases the number of fssile progenitors, the precursors of new neurons in the dentate gyrus of the hippocampus. The existing immunohistochemical methods for labeling new neurons do not allow tracing the temporal dynamics of changes in the volume of brain structures in the same animal, induced by external impacts, such as voluntary exercise. This makes it an urgent task to develop and improve methods for long­term control of changes that occur in the adult hippocampus due to the induction of neurogenesis. The main purpose of this work was to non­invasively track, by using magnetic resonance imaging (MRI), the temporal dynamics of changes in the volume of the hippocampus in the same animals that had voluntary physical activity. It was found that voluntary exercise did not change the total volume of the mouse hippocampus. However, the difference in the volume ratio between the right and left parts of the hippocampus was signifcantly lower compared with the control group. The reconstruction and analysis of protein­protein interactions that ensure the survival of a large number of new neurons and their integration into existing neural networks in the hippocampus have been carried out. The proposed approach allows the non­invasive registration of changes in the ratio of the volumes of these paired brain structures

The effect of nitrate nitrogen and salicylic acid on aerenchyma formation in typha angustifolia grown in mesocosms

Macrophytes play a significant role in the functioning of hydroecosystems. Their activities include changes at the physiological and anatomical levels toward the action of various pollutants. This study was intended to reveal some features in aerenchyma formation in roots of Typha angustifolia exposed to various concentrations of nitrate nitrogen and salicylic acid. It was found that the resistance of T. angustifolia to nitrate nitrogen is mediated by redistribution of aerenchyma formation in the root system. The action of salicylic acids results in decreasing influence of nitrate nitrogen in two types of adventitious roots. Features of aeren-chyma formation in the soilborne roots and aquatic ones were different. © 2011

Learning-induced sensory plasticity of mouse olfactory epithelium

Traditionally, studies of the neurobiology of learning and memory focus on the circuitry that interfaces between sensory inputs and behavioral outputs, such as the amygdala and cerebellum. However, evidence is accumulating that some forms of learning can in fact drive stimulus­specifc changes very early in sensory systems, including not only primary sensory cortices but also precortical structures and even the peripheral sensory organs themselves. In this study, we investigated the effect of olfactory associative training on the functional activity of olfactory epithelium neurons in response to an indifferent stimulus (orange oil). It was found that such a peripheral structure of the olfactory system of adult mice as the olfactory epithelium (OE) demonstrates experience­dependent plasticity. In our experiment, associative learning led to changes in the patterns of OE cell activation in response to orange oil in comparison with the control group and animals that were given odor without reinforcement. To interpret the results obtained, we compared the distribution of MRI contrast across the zones of OE in response to a conditioned odor in trained animals and in control animals that were given orange oil at three concentrations: original (used for conditioning), 4­fold higher and 4­fold lower. Since the OE activation patterns obtained coincided in the group of trained animals and controls, which were stimulated with orange oil at the 4­fold higher concentration, it can be concluded that associative conditioning increased the sensitivity of the OE to the conditioned stimulus. The observed increase in OE response to orange oil may be the result of neurogenesis, i. e. the maturation of new olfactory neurons responsive to this stimulus, or the consequence of an increase in individual sensitivity of each OE neuron. Based on data of MRI contrast accumulation in mouse OE, the sensory plasticity way in learning­induced increase in sensitivity of OE to conditioned stimulus is more possible. Thus, the sensory plasticity of the OE plays a signifcant role in the formation of the neuronal response to the provision of an initially indifferent odor and is part of the adaptive responses to the environmental changing

Handbook on the Carpathian Convention

This volume describes, article by article, the Carpathian Convention: the principles of international environmental law beyond each article, giving uselful examples of best practices and a detailed overview of the international documents providing guidance to its implementation. It is targeted at policy makers and all stakeholders involved in the implementationof the Convention itself

СВОЙСТВА ДЕМИНЕРАЛИЗОВАННОГО КОСТНОГО МАТРИКСА ДЛЯ БИОИНЖЕНЕРИИ ТКАНЕЙ

The purpose. Determination of tissues of physico-mechanical properties of demineralized bone matrix of spongy and compact human bone important for bioengineering.Material and Methods.The methods for studying micromorphological, piezoelectric and transport properties, adapted for measuring the materials of potential scaffolds.Results. The results of studying the physico-mechanical properties of the demineralized bone matrix of spongy and compact human bones are presented. It is shown that the demineralized spongy bone possesses the best characteristics of the pore system for the colonization of matrix cells. The tensile strength and modulus of elasticity of samples from the demineralized heads of the femurs extracted during the initial hip arthroplasty vary widely. The modulus of elasticity varied from 50 to 250 MPa, and the ultimate strength was from 1.1 to 5.5 MPa.Conclusion. Methods for measuring micromorphological, piezoelectric and transport properties for materials of potential matrices were developed and / or adapted. It is shown that in the samples of materials from the human bone, these characteristics, as a rule, vary considerably. Proceeding from this, it becomes obvious that the development of protocols of measurement methods of the above listed properties is an important work for the creation of technology of bioengineering of tissue implants for reconstructive surgery. Цель. Определение значимых для биоинженерии тканей физико-механических свойств деминерализованного костного матрикса губчатой и компактной кости человека.Материалы и методы. Перечислены методы исследования микроморфологических, пьезоэлектрических и транспортных свойств, адаптированные для измерения у материалов потенциальных матриц.Результаты. Приведены результаты исследования физико-механических свойств деминерализованного костного матрикса губчатой и компактной кости человека. Показано, что деминерализованная губчатая кость обладает наилучшими характеристиками поровой системы для заселения матриксов клетками. Предел прочности и модуль упругости образцов из деминерализованных головок бедренных костей, извлеченных в ходе первичного эндопротезирования тазобедренного сустава, изменяются в широких пределах. Модуль упругости изменялся от 50 до 250 МПа, а предел прочности – от 1,1 до 5,5 МПа.Заключение. Были отработаны и/или адаптированы методы измерений микроморфологических, пьезоэлектрических и транспортных свойств у материалов потенциальных матриц. Показано, что у образцов материалов из кости человека данные характеристики, как правило, значительно варьируют. Исходя из этого, становится очевидным, что отработка протоколов методов измерения вышеперечисленных свойств является важной работой для создания технологии биоинженерии тканевых имплантатов для восстановительной хирургии.

The effect of nitrate nitrogen and salicylic acid on aerenchyma formation in typha angustifolia grown in mesocosms

Macrophytes play a significant role in the functioning of hydroecosystems. Their activities include changes at the physiological and anatomical levels toward the action of various pollutants. This study was intended to reveal some features in aerenchyma formation in roots of Typha angustifolia exposed to various concentrations of nitrate nitrogen and salicylic acid. It was found that the resistance of T. angustifolia to nitrate nitrogen is mediated by redistribution of aerenchyma formation in the root system. The action of salicylic acids results in decreasing influence of nitrate nitrogen in two types of adventitious roots. Features of aeren-chyma formation in the soilborne roots and aquatic ones were different. © 2011

The effect of nitrate nitrogen and salicylic acid on aerenchyma formation in typha angustifolia grown in mesocosms

Macrophytes play a significant role in the functioning of hydroecosystems. Their activities include changes at the physiological and anatomical levels toward the action of various pollutants. This study was intended to reveal some features in aerenchyma formation in roots of Typha angustifolia exposed to various concentrations of nitrate nitrogen and salicylic acid. It was found that the resistance of T. angustifolia to nitrate nitrogen is mediated by redistribution of aerenchyma formation in the root system. The action of salicylic acids results in decreasing influence of nitrate nitrogen in two types of adventitious roots. Features of aeren-chyma formation in the soilborne roots and aquatic ones were different. © 2011