690 research outputs found
First year infant motor asymmetry origins and prevention: parental awareness survey
Objective of the study was to survey the parental awareness of the origins of infant motor asymmetry and its prevention method
Automated system for diagnosing craniocerebral injury
A Russian national computing and communication system designed to assist non-specialized physicians in the diagnosis and treatment of craniocerebral injury is described
Synthesis and antifungal activity of monoterpenoids of the carane series
The antifUngal activity of terpenoids of the carane series was studied; an interaction was found between the structures of these compounds and their antifungal properties. The actions of several terpenoids on the adhesive activity and enzyme systems of the fungus Candida albicans were studied. © 2012 Springer Science+Business Media, Inc
Antioxidant defense system: regulation of metabolic processes, genetic determinants, methods of determination
An increase in peroxidation activity is considered as a nonspecific process characteristic of the pathogenesis of various diseases accompanied by antioxidant deficiency. As bioregulators that can increase defense, antioxidants are important links in a multi-stage system of regulation and coordination of various body functions. The structure and function of enzymes involved in the regulation of oxidative stress can be significantly affected by genetic polymorphism. To date, the role of genes encoding the activity of enzymes of the antioxidant system in the pathogenesis of many diseases remains unexplored, which is of great interest to researchers from various fields. The article presents a review and analysis of data from modern scientific literature on the role of antioxidant defense components in the regulation of metabolic processes, their genetic determinant, and summarizes data on modern methods for the determination of some antioxidants. When writing the review, the database of the scientific electronic library eLibrary was used, the keywords are oxidative stress, free radical oxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, antioxidant response element, research methods; filters – publication years 2012–2022, publications with full text, publications available for viewing; English-language database of medical and biological publications, created by the National Center for Biotechnology Information (NCBI), keywords – lipid peroxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, oxidative stress, metabolism, methods
Structure-Sensitive Mechanism of Nanographene Failure
The response of a nanographene sheet to external stresses is considered in
terms of a mechanochemical reaction. The quantum chemical realization of the
approach is based on a coordinate-of-reaction concept for the purpose of
introducing a mechanochemical internal coordinate (MIC) that specifies a
deformational mode. The related force of response is calculated as the energy
gradient along the MIC, while the atomic configuration is optimized over all of
the other coordinates under the MIC constant-pitch elongation. The approach is
applied to the benzene molecule and (5, 5) nanographene. A drastic anisotropy
in the microscopic behavior of both objects under elongation along a MIC has
been observed when the MIC is oriented either along or normally to the C-C
bonds chain. Both the anisotropy and high stiffness of the nanographene
originate at the response of the benzenoid unit to stress.Comment: 19 pages, 7 figures 1 tabl
Nothing will ever be as before. Reflections on the COVID-19 epidemics by nephrologists in eleven countries
Synthesis of S-containing derivatives of the sesquiterpene lactone Britanin
The optimal method for isolating the sesquiterpene lactone britanin from the aerial part of Inula britannica L. (Asteraceae) was developed. Britanin was functionalized by reacting it with methyl mercaptoacetate. ©2005 Springer Science+Business Media, Inc
Extraordinary behavior of β-hydroxy sulfoxides and sulfone of pinane series
© 2017 Taylor & Francis Group, LLC.The “racemic compound-like” behavior, low-temperature conformational rearrangement and “crystallization-induced diastereomerization” of β-hydroxysulfoxides and sulfone of pinane series have been studied. It was established, that the sample of sulfoxide crystallizes as an asymmetric dimer containing a supramolecularcentro-symmetric moiety formed through S=O···H‒O interactions between two independent molecules. Moreover, it was found that this dimer can crystallize in two so-called “packing polymorphs”—monoclinic and triclinic ones. By transition from the room temperature to 150 К for both polymorphic forms conformational restructuring of a stable hydrogen-bonded synthon from “unfolded” form to “folded” one has been observed. The sample of sulfoxide is interesting as the first example of the co-crystallization of chiral sulfur compounds. Surprisingly we have found a similar H-bonded dimer, formed by independent molecules, where all sulfone molecules are identical in stereochemical aspect. We suggested to use the new term “crystallization-induced diastereomerization” for the description of the stereochemical process leading to the formation of sulfone dimer. From a supramolecular chemistry point of view, we can speak of the finding of a new robust and reproducible synthon. From a stereochemical point of view, an “enantiophilic” fragment was discovered—a β-hydroxysulfoxide or sulfone group, capable of recognizing its mirror image
Functional state of the nigrostriatal system of Krushinsky – Molodkina rats during audiogenic seizure expression
Neurochemical mechanisms of initiation and expression of epileptic seizures are poorly explored, and there are no published data that could demonstrate the functional state of the neuromediator systems at the initial state of seizure in the animals genetically prone to seizure. In the current work, we studied the role of extracellular signal-regulated kinase (ERK1/2) in the regulation of the nigrostriatal glutamate, GABA and dopamine neurons of Krushinsky – Molodkina rats at clonus-tonus and ataxia stages of audiogenic seizure. We demonstrated upregulation of ERK1/2 activity upon audio stimulation which was accompanied by increased activation of Synapsin I in the striatum and substantia nigra in comparison to intact Krushinsky – Molodkina rats. The observed exocytosis activation led to secretion of glutamate in the striatum and, as a result, to stimulation of seizures. However, at clonus-tonus stage in the striatum we revealed the changes that could participate in further inhibition of seizure activity, such as increased phosphorylation of tyrosine hydroxylase upon increased ERK1/2 activity followed by activation of dopamine release in the pars compacta of the substantia nigra. At the same time, enhanced D2 and increased D1 dopamine receptor contents were observed. These data revealed attenuation of direct (pro-seizure) and indirect (anti-seizure) pathways of the regulation of the substantia nigra GABA neurons. We demonstrated activation of GABA in the substantia nigra pars reticulate, which probably results in the inhibition of glutamate neurons of the thalamus and could be one of the mechanisms inhibiting seizure activity during ataxia
Морфологічні особливості печінки статевозрілої собаки
The article describes the features of the macroscopic and microscopic structure of the liver of mature clinically healthy dogs for the use of anatomical, histological and morphometric methods of research. According to the results of organometallic and cytometric studies, the absolute and relative body mass, the volume of hepatocytes, their nuclei and the nuclear-cytoplasmic ratio were determined. Thus, the absolute weight of the liver in the mature dogs is variable and to a certain extent depends on the blood flow to the organ and is 427.4 ± 21.92 g, the relative weight – 2.69 ± 0.1%. Liver of mature dogs is a compact body of flattened form with sharp lower and lateral edges, with deep cuts, dark red color. The histoarhitectonics of the liver of dogs are constructed with connective tissue and parenchyma. The stroma of the organ is formed by a capsule, on top of which is serous membrane. In the area of the gates of the liver, the connective tissue of the capsule penetrates into the middle of the organ, branching and dividing it into lobules. Then it is formed by the hepatic plates by the intraosseous sinusoid capillaries. Liver plates are specific endpoint of the secretory unit of the liver. It has been found that in the microscopic structure of the liver of the dogs, the interstitial connective tissue is poorly developed, therefore the boundaries between the liver lobules are not sufficient. The liver plates behind the microscopic structure have a radial direction from the center to the periphery. The direction closer to the periphery of the particles is less noticeable, since hepatocytes are located in two rows, between which the sinusoidal space clearly appears. Hepatocytes had an irregular, multifaceted form. Their nuclei, which were mainly in the center of the cell, had little clarity of contours of carriel and well perceived color. During microscopic examination of the liver, it is swollen that hepatocytes of the central and intermediate zones are better perceived by color than the cytoplasm of the cells of the peripheral zone of the liver. According to the analysis of our cytomorphometric studies, hepatocytes of dogs have different sizes, which vary in wide range: from small to large. Whereas the average volume of hepatocytes in mature dogs is 964.72 ± 56.003 μm³; the average volume of their nuclei is 105.13 ± 2.02 microns. The nuclear-cytoplasmic ratio of hepatocytes in dogs of this group is 0.128 ± 0.122.У статті за використання анатомічних, гістологічних та морфометричних методів досліджень викладено особливості макро- та мікроскопічної будови печінки статевозрілих клінічно здорових собак. За результатами органо – гісто- та цитометричних досліджень з’ясовано абсолютну та відносну масу органу, об’єм гепатоцитів, їх ядер та ядерно-цитоплазматичне відношення. Так, абсолютна маса печінки у статевозрілих собак мінлива і в певній мірі залежить від кровонаповнення органа і становить 427,4 ± 21,92 г, відносна маса – 2,69 ± 0,1%. Печінка статевозрілих собак компактний орган сплющеної форми з гострими нижнім і бічними краями, з глибокими вирізками, темно-червоного кольору. Гістоархітектоніка печінки собак побудована зі сполучнотканинної строми і зі паренхіми. Строма органа сформована капсулою, поверх якої міститься серозна оболонка. У ділянці воріт печінки, сполучна тканина капсули проникає всередину органа, розгалужується і ділить його на часточки. Останні утворені печінковими пластинками внутрішньочасточковими синусоїдними капілярами. Печінкові пластинки являють собою специфічний кінцевий секреторний відділ печінки. З’ясовано, що у мікроскопічній будові печінки собак міжчасточкова сполучна тканина слабко розвинена, тому межі між печінковими часточками маловиражені. Печінкові пластинки за мікроскопічної будови мають радіальний напрямок, від центру до периферії. Ближче до периферії часточок їх напрямок менш помітний, оскільки гепатоцити розташовувались двома рядами, між якими чітко виявляється синусоїдальний простір. Гепатоцити мали неправильну, багатогранну форму. Їх ядра, які містилися в основному у центрі клітини, мали чітко контуровану каріолему і добре сприймали забарвлення. Під час мікроскопічного дослідження печінки відмічено, що гепатоцити центральної і проміжної зон краще сприймали забарвлення, ніж цитоплазма клітин периферичної зони печінкової частки. Згідно з аналізом проведених нами цитоморфометричних досліджень, гепатоцити собак мають різні розміри, які коливаються у широких межах: від малих до великих. При тім, що середній об’єм гепатоцитів у статевозрілих собак становить 964,72 ± 56,003 мкм³; середній об’єм їх ядер – 105,13 ± 2,02 мкм3. Ядерно-цитоплазматичне відношення гепатоцитів у собак цієї групи складає 0,128 ± 0,122
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