42 research outputs found

    Heat balance of the Earth

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    Results of improved calculations of the heat balance components of Earth's surface are reported for yearly average conditions. The technique used to determine the heat-balance components from land- and sea-based actinometric observations as well as from satellite data on the radiation balance of the Earth-atmosphere system is described, with special attention given to short-wavelength solar radiation on the continents, effective radiation from the land surface, the radiation balance of the ocean surface, heat expended by both evaporation from the ocean surface, and turbulent heat transfer between the ocean surface and the atmosphere. World maps of heat-balance components show yearly average values of total radiation, radiation balance, heat expended by evaporation, the turbulent heat flow between Earth's surface and atmosphere, and heat transfer between the ocean surface and underlying waters. The global surface heat balance is estimated along with global values of the various components and the heat-balance components for different latitude zones

    Стан метаболічних показників крові білих щурів за субхронічного перорального надходження наночастинок ортованадату гадолінію на фоні кормового стресу

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    The prohibition of using antibiotics with growth-stimulating properties in the European Union led to the search for new, safer, more effective, and cheaper feed additives. One of these substances was rare earth elements (REE, atomic numbers 57–71) due to their low toxicity and protective and antioxidant properties. At the same time, higher efficiency of organic forms of REE was noted. Thanks to this, it is possible to assume their even more pronounced effect in nano-sized form as feed additives and the need to conduct research in this direction. Therefore, this work aims to study the metabolic parameters of the blood in rats under long-term oral administration of nanoparticles of one of the representatives of rare earth elements – gadolinium orthovanadate (NP GdVO4:Eu3+) under food stress. Experimental samples of gadolinium orthovanadate nanoparticles activated by Europium (spindle-shaped geometry; size 8×25 nm; initial concentration 1.0 g/dm3) were used in work. Experimental studies on rats were carried out based on the vivarium of the NSC “IEKVM”. The object of research was 140 mature male Wistar rats with an initial weight of 180–200 g. Four groups of animals, 35 rats each, were formed according to the principle of analogs. During the experiment, animals of the control group received drinking water without additives; rats of the І experimental group were given a solution of NP GdVO4:Eu3+ at a dose of 0.2 mg/dm3 (≈ 0.03 mg/kg of body weight); II research group – at a dose of 1.0 mg/dm3 (≈ 0.15 mg/kg of body weight) and rats of III research group – at a dose of 2.0 mg/dm3 (≈ 0.30 mg/kg of body weight). Drinking was carried out for 56 days, then it was completed, and the rats were observed for another 14 days. A nutritionally unbalanced diet was used as a stress factor. Taking into account the results of biochemical studies, the adaptogenic effect of NP GdVO4:Eu3+ in the range of doses of 0.2–1.0 mg/dm3 of drinking water (≈ 0.03–0.15 mg/kg of body weight) on the body of white rats was established under conditions of food stress with optimal duration of action – 28–42 days. Under the conditions of administration at a dose of 2.0 mg/dm3 of drinking water (≈ 0.30 mg/kg of body weight), a hepatic(cyto-)toxic effect of nanoparticles was detected, which was accompanied by an irreversible decrease in the structural indicators of lipid metabolism, the consumption of antioxidant resources and the induction of intensity processes of lipid peroxidation against the background of alanine aminotransferase hyperenzymemia.Заборона у Європейському Союзі застосування антибіотиків з ростостимулювальними властивостями спровокувала потребу пошуку нових більш безпечних, ефективних та дешевих кормових добавок. Одними з таких речовин виявилися рідкісноземельні елементи (РЗЕ, атомні номери 57–71), завдяки низькій токсичності, протекторним та антиоксидантним властивостям. При цьому виявлено вищу ефективність органічних форм РЗЕ, що дозволяє зробити припущення про ще більш виражену їх дію у нанорозмірній формі як кормових добавок і необхідність проводити дослідження в цьому напрямі. Тому метою даної роботи стало дослідження метаболічних показників крові щурів за субхронічного переорального надходження наночастинок одного з представників рідкісноземельних елементів – ортованадату гадолінію (NP GdVO4:Eu3+) на фоні кормового стресу. У роботі використовували дослідні зразки наночастинок ортованадату гадолінію, активованих Європієм (веретеноподібна геометрія; розмір 8×25 нм; вихідна концентрація 1,0 г/дм3). Експериментальні дослідження на щурах були проведені на базі віварію ННЦ “ІЕКВМ”. Як об’єкт досліджень було використано 140 статевозрілих щурів-самців лінії Wistar з початковою масою (180–200) г. За принципом аналогів було сформовано 4 групи тварин по 35 щурів у кожній. Упродовж експерименту тварини контрольної групи отримували питну воду без добавок; щурам І дослідної групи випоювали розчин NP GdVO4:Eu3+ у дозі 0,2 мг/дм3 (≈ 0,03 мг/кг маси тіла); ІІ дослідної групи – у дозі 1,0 мг/дм3 (≈ 0,15 мг/кг маси тіла) і щурам ІІІ дослідної групи – у дозі 2,0 мг/дм3 (≈ 0,30 мг/кг маси тіла). Випоювання здійснювали протягом 56 діб, потім його завершували і спостерігали за щурами ще 14 діб. Як стресовий фактор використовували незбалансований за поживними речовинами раціон. Враховуючи результати біохімічних досліджень, за умов кормового стресу установлено адаптогенну дію NP GdVO4:Eu3+ у діапазоні доз 0,2–1,0 мг/дм3 питної води (≈ 0,03 – 0,15 мг/кг маси тіла) на організм білих щурів із оптимальним терміном дії – 28–42 доби, тимчасом як за введення у дозі 2,0 мг/дм3 питної води (≈ 0,30 мг/кг маси тіла) виявлено гепато(цито-)токсичну дію наночастинок, що супроводжується незворотним зниженням структурних показників ліпідного обміну, витрачанням антиоксидантних ресурсів та індукцією інтенсивності процесів пероксидного окиснення ліпідів на фоні гіперензимемії аланінамінотрансферази

    A chimerical phagocytosis model reveals the recruitment by Sertoli cells of autophagy for the degradation of ingested illegitimate substrates

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    Phagocytosis and autophagy are typically dedicated to degradation of substrates of extrinsic and intrinsic origins respectively. Although overlaps between phagocytosis and autophagy were reported, the use of autophagy for ingested substrate degradation by nonprofessional phagocytes has not been described. Blood-separated tissues use their tissue-specific nonprofessional phagocytes for homeostatic phagocytosis. In the testis, Sertoli cells phagocytose spermatid residual bodies produced during germ cell differentiation. In the retina, pigmented epithelium phagocytoses shed photoreceptor tips produced during photoreceptor renewal. Spermatid residual bodies and shed photoreceptor tips are phosphatidylserine-exposing substrates. Activation of the tyrosine kinase receptor MERTK, which is implicated in phagocytosis of phosphatidylserine-exposing substrates, is a common feature of Sertoli and retinal pigmented epithelial cell phagocytosis. The major aim of our study was to investigate to what extent phagocytosis by Sertoli cells may be tissue specific. We analyzed in Sertoli cell cultures that were exposed to either spermatid residual bodies (legitimate substrates) or retina photoreceptor outer segments (illegitimate substrates) the course of the main phagocytosis stages. We show that whereas substrate binding and ingestion stages occur similarly for legitimate or illegitimate substrates, the degradation of illegitimate but not of legitimate substrates triggers autophagy as evidenced by the formation of double-membrane wrapping, MAP1LC3A-II/LC3-II clustering, SQSTM1/p62 degradation, and by marked changes in ATG5, ATG9 and BECN1/Beclin 1 protein expression profiles. The recruitment by nonprofessional phagocytes of autophagy for the degradation of ingested cell-derived substrates is a novel feature that may be of major importance for fundamentals of both apoptotic substrate clearance and tissue homeostasis

    Transcriptional Activation of REST by Sp1 in Huntington's Disease Models

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    In Huntington's disease (HD), mutant huntingtin (mHtt) disrupts the normal transcriptional program of disease neurons by altering the function of several gene expression regulators such as Sp1. REST (Repressor Element-1 Silencing Transcription Factor), a key regulator of neuronal differentiation, is also aberrantly activated in HD by a mechanism that remains unclear. Here, we show that the level of REST mRNA is increased in HD mice and in NG108 cells differentiated into neuronal-like cells and expressing a toxic mHtt fragment. Using luciferase reporter gene assay, we delimited the REST promoter regions essential for mHtt-mediated REST upregulation and found that they contain Sp factor binding sites. We provide evidence that Sp1 and Sp3 bind REST promoter and interplay to fine-tune REST transcription. In undifferentiated NG108 cells, Sp1 and Sp3 have antagonistic effect, Sp1 acting as an activator and Sp3 as a repressor. Upon neuronal differentiation, we show that the amount and ratio of Sp1/Sp3 proteins decline, as does REST expression, and that the transcriptional role of Sp3 shifts toward a weak activator. Therefore, our results provide new molecular information to the transcriptional regulation of REST during neuronal differentiation. Importantly, specific knockdown of Sp1 abolishes REST upregulation in NG108 neuronal-like cells expressing mHtt. Our data together with earlier reports suggest that mHtt triggers a pathogenic cascade involving Sp1 activation, which leads to REST upregulation and repression of neuronal genes

    Structural Heterogeneity and Quantitative FRET Efficiency Distributions of Polyprolines through a Hybrid Atomistic Simulation and Monte Carlo Approach

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    Förster Resonance Energy Transfer (FRET) experiments probe molecular distances via distance dependent energy transfer from an excited donor dye to an acceptor dye. Single molecule experiments not only probe average distances, but also distance distributions or even fluctuations, and thus provide a powerful tool to study biomolecular structure and dynamics. However, the measured energy transfer efficiency depends not only on the distance between the dyes, but also on their mutual orientation, which is typically inaccessible to experiments. Thus, assumptions on the orientation distributions and averages are usually made, limiting the accuracy of the distance distributions extracted from FRET experiments. Here, we demonstrate that by combining single molecule FRET experiments with the mutual dye orientation statistics obtained from Molecular Dynamics (MD) simulations, improved estimates of distances and distributions are obtained. From the simulated time-dependent mutual orientations, FRET efficiencies are calculated and the full statistics of individual photon absorption, energy transfer, and photon emission events is obtained from subsequent Monte Carlo (MC) simulations of the FRET kinetics. All recorded emission events are collected to bursts from which efficiency distributions are calculated in close resemblance to the actual FRET experiment, taking shot noise fully into account. Using polyproline chains with attached Alexa 488 and Alexa 594 dyes as a test system, we demonstrate the feasibility of this approach by direct comparison to experimental data. We identified cis-isomers and different static local environments as sources of the experimentally observed heterogeneity. Reconstructions of distance distributions from experimental data at different levels of theory demonstrate how the respective underlying assumptions and approximations affect the obtained accuracy. Our results show that dye fluctuations obtained from MD simulations, combined with MC single photon kinetics, provide a versatile tool to improve the accuracy of distance distributions that can be extracted from measured single molecule FRET efficiencies

    Melanosomes in pigmented epithelia maintain eye lens transparency during zebrafish embryonic development

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    Altered levels of trace elements are associated with increased oxidative stress that is eventually responsible for pathologic conditions. Oxidative stress has been proposed to be involved in eye diseases, including cataract formation. We visualized the distribution of metals and other trace elements in the eye of zebrafish embryos by micro X-ray fluorescence (mu-XRF) imaging. Many elements showed highest accumulation in the retinal pigment epithelium (RPE) of the zebrafish embryo. Knockdown of the zebrafish brown locus homologues tyrp1a/b eliminated accumulation of these elements in the RPE, indicating that they are bound by mature melanosomes. Furthermore, albino (slc45a2) mutants, which completely lack melanosomes, developed abnormal lens reflections similar to the congenital cataract caused by mutation of the myosin chaperon Unc45b, and an in situ spin trapping assay revealed increased oxidative stress in the lens of albino mutants. Finally transplanting a wildtype lens into an albino mutant background resulted in cataract formation. These data suggest that melanosomes in pigment epithelial cells protect the lens from oxidative stress during embryonic development, likely by buffering trace elements.Peer reviewe

    QUALITATIVE AND QUANTITATIVE ANALYSIS OF BIOLOGICALY ACTIVE COMPONENTS IN MIXTURE OF MULTIVITAMIN RAW MATERIAL OF FOLIA URTICAE AND FRUCTUS SORBI (REVIEW)

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    The article presents the chemical composition of medicinal plants the mixture of the multivitamin raw material. The methods of identification biologically active compounds, depending on their nature, such as the qualitative of the reaction, thin layer chromatography, high performance liquid chromatography are considered. Methods of quantitative definition as separate components of a metabolom of folia Urticae and fructus Sorbi, and total content of biologically active connections are given

    The electronic register patients with hypertensia in Tomsk Region

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    Within the limits of the regional program «Prevention and treatment of an arterial hypertension for the period of 2004—2008» the electronic register of the patients with hypertensia inTomskRegion has been created.The electronic register is a two-level system where interaction of two kinds of databases is carried out: the first level is the databases of separate medical organization; the second level is the central integrated database.The basic information for the electronic register are documents confirmed by the Health service Ministry of the Russian Federation, that is the coupon of the out-patient patient and a card of dynamic supervision over the patient with hypertensia.All the data about the patients, included in the register are subdivided into unchangeable and changeable ones.The electronic register is an effective control system providing local leading of health service bodies with qualitative and high-grade information in processes of preparation of decision-making and measure taken for prevention and treatment of hypertensia.The electronic register is an effective monitoring system, providing medical authority of important information for taking decisions establishment measures for prevention and treatment of hypertensia

    Myelinosome-like vesicles in human seminal plasma A cryo-electron microscopy study

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    International audienceSeminal plasma is particularly rich in extracellular vesicles. Myelinosomes are membranous organelles described throughout the seminiferous epithelium of the testis but never reported in semen. Our aim was to determine the presence of myelinosomes in human seminal plasma. Transmission electron microscopy and cryo electron microscopy analysis of standard myelinosome preparation from TM4 Sertoli cells and human seminal plasma samples. We have specified by cryo-EM the morphological aspect of "standard" myelinosomes isolated from the culture media of TM4 Sertoli cells. Vesicles with the same morphological appearance were revealed in human seminal plasma samples. Human seminal plasma contains a population of large EV (average diameter 200 nm) whose morphological appearance resemble those of myelinosomes. Defining the specific biomarkers and functionalities of myelinosome in human seminal plasma are the concerns to be addressed in our further research

    Hereditary colorectal cancer: genetics and screening diagnostics

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    Aim of review. To present the data on main forms of hereditary colorectal cancer (CRC) and to discuss issues of its diagnostics, genetic testing and patient management. Summary. CRC is one of the most widespread oncologic diseases and takes the leading positions for morbidity and mortality in the pattern of neoplastic diseases in Russia. In 30% of cases disease development is associated to genetic predisposition, however only 5% of all CRC cases are linked to established hereditary syndromes, such as Lynch syndrome (hereditary non-polyposis colorectal cancer), family adenomatous polyposis, MUTYH-associated polyposis, juvenile polyposis, hereditary mixed polyposis syndrome, Peutz-Jeghers syndrome and serrated polyposis syndrome. The current review presents clinical and genetic features of two basic colorectal hereditary syndromes - Lynch syndrome and family adenomatous polyposis. Conclusion. Both clinical and molecular genetic investigations of hereditary CRC forms make possible individual comprehensive approach for diagnosis verification, evaluation of cancer risk, early diagnostics, treatment and prevention for decrease of morbidity and mortality
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