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003.01. National Laboratory Astana

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Open Access
A simple approach to synthesize novel sulfur/graphene oxide/multiwalled carbon nanotube composite cathode for high performance lithium/sulfur batteries
(Ionics. Springer-Verlag Berlin Heidelberg 2016, 2016-04-30) Yuan, Guanghui; Zhao, Yan; Jin, Huafeng; Bakenov, Zhumabay
A sulfur/graphene oxide/multiwalled carbon nanotube (S/GO/MWNT) composite was synthesized via a simple ultrasonic mixing method followed by heat treatment. By taking advantage of this solution-based self-assembly synthesis route, poisonous and noxious reagents and complicated fabrication processes are rendered unnecessary, thereby simplifying its manufacturing and decreasing the cost of the final product. Transmission and scanning electronic microscopy observations indicated the formation of the threedimensional interconnected S/GO/MWNTcomposite through the environmentally friendly process...
Open Access
Aberrant DNA glycosylase-initiated repair pathway of free radicals induced DNA damage: implications for age-related diseases and natural aging
(Biopolymers and Cell. doi: http://dx.doi.org/10.7124/bc.000943, 2017) Matkarimov, B.; Saparbaev, M.
Aerobic cellular respiration generates reactive oxygen species (ROS), which can damage macro-molecules including lipids, proteins and DNA. It was proposed that aging is a consequence of accumulation of naturally occurring unrepaired oxidative DNA damage. In human cells, approximately 2000 to 8000 DNA lesions occur per hour in each cell, i.e. 40000 to 200000 per cell per day. DNA repair systems are able to discriminate between regular and modified bases. For example, DNA glycosylases specifically recognize and excise damaged bases among vast majority of regular bases in the base excision repair (BER) pathway. However, mismatched pairs between two regular bases occur due to spontaneous conversion of 5-methylcytosine to thymine and DNA polymerase errors during replication. To counteract these mutagenic threats to genome stability, cells evolved special DNA repair systems that target the non-damaged DNA strand in a duplex to remove mismatched regular DNA bases. Base excision repair (BER) and mismatch repair (MMR) pathways initiated by mismatch-specific adenine- and thymine-DNA glycosylases (MutY/MUTYH and TDG/MBD4, respectively) can recognize and remove normal DNA bases in mismatched DNA duplexes. Under certain circumstances in DNA repair deficient cells bacterial MutY and human TDG can act in an aberrant manner: MutY and TDG remove Adenine and Thymine opposite to misincorporated 8-oxoguanine and damaged Adenine, respectively. These unusual activities lead either to mutations or futile DNA repair, thus indicating that the DNA repair pathways which target non-damaged DNA strand can act in an aberrant manner and introduce genome instability in the presence of unrepaired DNA lesions. Both accumulation of oxidative DNA damage in cells and the aberrant DNA repair can contribute to cancer, brain disorders and premature senescence.
Open Access
Aberrant repair initiated by mismatch-specific thymine-DNA glycosylases provides a mechanism for the mutational bias observed in CpG islands
(Nucleic Acids Research, 2014-04-01) Talhaoui, Ibtissam; Couve, Sophie; Gros, Laurent; Ishchenko, Alexander A.; Matkarimov, Bakhyt; Saparbaev, Murat K.
The human thymine-DNA glycosylase (TDG) initiates the base excision repair (BER) pathway to remove spontaneous and induced DNA base damage. It was first biochemically characterized for its ability to remove T mispaired with G in CpG context. TDG is involved in the epigenetic regulation of gene expressions by protecting CpG-rich promoters from de novo DNA methylation. Here we demonstrate that TDG initiates aberrant repair by excising T when it is paired with a damaged adenine residue in DNA duplex. TDG targets the non-damaged DNA strand and efficiently excises T opposite of hypoxanthine (Hx), 1,N6-ethenoadenine, 7,8-dihydro-8-oxoadenine and abasic site in TpG/CpX context, where X is a modified residue. In vitro reconstitution of BER with duplex DNA containing Hx•T pair and TDG results in incorporation of cytosine across Hx. Furthermore, analysis of the mutation spectra inferred from single nucleotide polymorphisms in human population revealed a highly biased mutation pattern within CpG islands (CGIs), with enhanced mutation rate at CpA and TpG sites. These findings demonstrate that under experimental conditions used TDG catalyzes sequence context-dependent aberrant removal of thymine, which results in TpG, CpA→CpGmutations, thus providing a plausible mechanism for the putative evolutionary origin of the CGIs in mammalian genomes.
Open Access
AGE REPROGRAMMING AND EPIGENETIC REJUVENATION
(International conference "MODERN PERSPECTIVES FOR BIOMEDICAL SCIENCES: FROM BENCH TO BEDSIDE”; National Laboratory Astana, 2020) Kulaissova, A.; Singh, Prim B.
Introduction: Age reprogramming represents a novel method for generating patient-specific tissues for transplantation. It bypasses the de-differentiation/re-differentiation cycle that is characteristic of the induced pluripotent stem (iPS) and nuclear transfer-embryonic stem (NT-ES) cell technologies that drive current interest in regenerative medicine. Despite the obvious potential of iPS and NT-ES cell-based therapies, there are several problems that must be overcome before these therapies are safe and routine. Methods: As an alternative, age reprogramming aims to rejuvenate the specialized functions of an old cell without de-differentiation; age reprogramming does not require developmental reprogramming through an embryonic stage, unlike the iPS and NT-ES cell-based therapies. Tests of age reprogramming have largely focused on one aspect, the epigenome. Results: We have shown that epigenetic rejuvenation can be achieved in vitro in the absence of dedifferentiation using iPS cell reprogramming factors. Recent Studies on the dynamics of epigenetic age (eAge) reprogramming have demonstrated that the separation of eAge from developmental reprogramming can be explained largely by their different kinetics. Age reprogramming has also been achieved in vivo and shown to increase lifespan in a premature ageing mouse model. Conclusion: We conclude that age and developmental reprogramming can be disentangled and regulated independently in vitro and in vivo. The stage is now set to develop technologies that will rejuvenate cells without the need to go through an embryonic stage – that is to simply make old cells young.
Open Access
Air Pollution in Kazakhstan and Its Health Risk Assessment
(Ubiquity Press, 2019-11-08) Saliev, Timur; Kenessary, D; Kenessary, A; Adilgereiuly, Z; Akzholova, N; Erzhanova, A; Dosmukhametov, A; Syzdykov, D; Masoud, Abdul-Razak
ir pollution in Kazakhstan is caused by many factors and poses serious threats to public health. Ambient air in the cities of Kazakhstan is polluted due to mining and processing of mineral resources, oil and gas production, gasoline and diesel fuel motor vehicles, industrial enterprises.
Open Access
Amyloid-b peptide on sialyl-LewisX-selectin-mediated membrane tether mechanics at the cerebral endothelial cell surface
(PLOS ONE:Open Access journal, 2013-04-12) Askarova, Sholpan; Sun, Zhe; Sun, Grace Y.; Meininger, Gerald A.; Lee, James C-M.
Increased deposition of amyloid-b peptide (Ab) at the cerebral endothelial cell (CEC) surface has been implicated in enhancement of transmigration of monocytes across the brain blood barrier (BBB) in Alzheimer’s disease (AD). In this study, quantitative immunofluorescence microscopy (QIM) and atomic force microscopy (AFM) with cantilevers biofunctionalized by sialyl-Lewisx (sLex) were employed to investigate Ab-altered mechanics of membrane tethers formed by bonding between sLex and p-selectin at the CEC surface, the initial mechanical step governing the transmigration of monocytes. QIM results indicated the ability for Ab to increase p-selectin expression at the cell surface and promote actin polymerization in both bEND3 cells (immortalized mouse CECs) and human primary CECs. AFM data also showed the ability for Ab to increase cell stiffness and adhesion probability in bEND3 cells. On the contrary, Ab lowered the overall force of membrane tether formation (Fmtf), and produced a bimodal population of Fmtf, suggesting subcellular mechanical alterations in membrane tethering. The lower Fmtf population was similar to the results obtained from cells treated with an F-actin-disrupting drug, latrunculin A. Indeed, AFM results also showed that both Ab and latrunculin A decreased membrane stiffness, suggesting a lower membrane-cytoskeleton adhesion, a factor resulting in lower Fmtf. In addition, these cerebral endothelial alterations induced by Ab were abrogated by lovastatin, consistent with its anti-inflammatory effects. In sum, these results demonstrated the ability for Ab to enhance p-selectin expression at the CEC surface and induce cytoskeleton reorganization, which in turn, resulted in changes in membrane-cytoskeleton adhesion and membrane tethering, mechanical factors important in transmigration of monocytes through the BBB.
Open Access
ANALYSIS OF BACTEROIDES FRAGILIS CLINICAL STRAINS ISOLATED IN KAZAKHSTAN
(Microbiology Resource Announcements, 2021-02-04) Zholdybayeva, Elena V.; Kozhahmetova, Saniya; Tarlykov, Pavel; Atavliyeva, Sabina; Mukhtarova, Kymbat; Syzdykov, Tleuli; Khasenov, Ruslan; Shevtsov, Alexsandr; Amirgazin, Asylulan; Daniyarov, Asset; Ramankulov, Yerlan
Our aim was to study the nucleotide sequences of 9 previously undescribed strains of B. fragilis collected from patients with intra-abdominal diseases at city hospitals in Nur-Sultan, Kazakhstan.
Open Access
APOPTOTIC EFFECT OF ELECTROMAGNETIC FIELD ON ASTROCYTES
(International conference "MODERN PERSPECTIVES FOR BIOMEDICAL SCIENCES: FROM BENCH TO BEDSIDE”; National Laboratory Astana, 2020) Begimbetova, Dinara; Baiskhanova, Dinara
Introduction: Over the past decade, the use of mobile phones in many countries of the world has increased by almost 100%, and this increase has raised concerns about possible risks to human health. In addition to the emission of mobile phones and, effects of base stations of mobile communication are also possible. Compared to other organs, the brain is subject to relatively high specific absorption rates due to the close proximity of the cell phone device to the user’s head. The data show that even ultra-low EMF is powerful enough to disrupt biological processes at the cellular level, but more research is needed in this direction to understand the basic mechanisms. Methods: The experiments used primary cortical astrocytes obtained using the standard procedure for stratification of cells from abortion material of laboratory rats Rattus Norvegicus. Portable Faraday cage with electromagnetic signals up to 6 GHz. EMFaraCage® (Standard EMFaraCage® RF Shielding Test Enclosure) was used with the EMF emitted by the antenna. Cells were exposed to EMFs with a power of 900 and 1800 MHz at time intervals of 10, 30, 60, minutes, and 24 and 48 hours. Early apoptosis levels using CellEvent ™ Caspase-3/7 Green Detection Reagent (Invitrogen) fluorescence reagents and Propidium Iodid Blue (Invitrogen) late apoptosis on a Cytation 5 multifunction cell imaging reader. Results: The experimental results showed a statistically insignificant increase in the frequency of early and late apoptosis when exposed to EMF with a power of 900 MHz at all time intervals. When exposed to an EMF with a frequency of 1800 MHz, the activation of Annexin Caspase 3/7 and propidium iodide was statistically insignificant in temporary exposures of 10, 30, 60, minutes, and 24 hours. An increase in the level of early apoptosis when exposed to EMF with a frequency of 1800 MHz for 48 hours was statistically significant (p ≤ 0.01). The level of late apoptosis (propidium iodide) of this exposure remained at the level of intact exposure. Thus, a significant negative effect of apoptosis was noted at its early stage with maximum exposure to EMF. To further study the mechanism of induction of apoptosis of EMF, the genotoxic effect of EMF will be investigated. Acknowledgements: This work was supported by grant to Dinara Begimbetova from MES RK grant AP05133910, “Bio-effects of Electromagnetic Radiation from Mobile Phones and Wi-Fi on DNA of brain cells”.
Open Access
THE ARABIDOPSIS THALIANA POLY(ADP-RIBOSE) POLYMERASES 1 AND 2 MODIFY DNA BY ADP-RIBOSYLATING TERMINAL PHOSPHATE RESIDUES
(Frontiers Media, 2020-11-26) Taipakova, Sabira; Kuanbay, Aigerim; Saint-Pierre, Christine; Gasparutto, Didier; Baiken, Yeldar; Groisman, Regina; Ishchenko, Alexander A.; Saparbaev, Murat; Bissenbaev, Amangeldy K.
Proteins from the poly(ADP-ribose) polymerase (PARP) family, such as PARP1 and PARP2, use NAD+ as a substrate to catalyze the synthesis of polymeric chains consisting of ADP-ribose units covalently attached to an acceptor molecule. PARP1 and PARP2 are viewed as DNA damage sensors that, upon binding to strand breaks, poly(ADP-ribosyl)ate themselves and nuclear acceptor proteins. The flowering plant Arabidopsis thaliana contains three genes encoding homologs of mammalian PARPs: atPARP1, atPARP2, and atPARP3. Both atPARP1 and atPARP2 contain poly(ADP-ribosyl)ating activity; however, it is unknown whether they could covalently modify DNA by ADP-ribosylating the strand break termini. Here, we report that similar to their mammalian counterparts, the plant atPARP1 and atPARP2 proteins ADP-ribosylate 5′-terminal phosphate residues in duplex DNA oligonucleotides and plasmid containing at least two closely spaced DNA strand breaks. AtPARP1 preferentially catalyzes covalent attachment of ADP-ribose units to the ends of recessed DNA duplexes containing 5′-phosphate, whereas atPARP2 preferentially ADP-ribosylates the nicked and gapped DNA duplexes containing the terminal 5′-phosphate. Similar to their mammalian counterparts, the plant PARP-catalyzed DNA ADP-ribosylation is particularly sensitive to the distance that separates two strand breaks in the same DNA molecule, 1.5 and 1 or 2 turns of helix for atPARP1 and atPARP2, respectively. PAR glycohydrolase (PARG) restored native DNA structure by hydrolyzing the PAR–DNA adducts generated by atPARPs. Biochemical and mass spectrometry analyses of the PAR–DNA adducts showed that atPARPs utilize phosphorylated DNA termini as an alternative to protein acceptor residues to catalyze PAR chain synthesis via phosphodiester bond formation between C1′ of ADP-ribose and a phosphate residue of the terminal nucleotide in DNA fragment. Taken together, these data establish the presence of a new type of DNA-modifying activity in Arabidopsis PARPs, suggesting a possible role of DNA ADP-ribosylation in DNA damage signaling and repair of terrestrial plants.
Open Access
Around Semipalatinsk nuclear test site: progress of dose estimations relevant to the consequences of nuclear tests
(J. Radiat. Res. Vol. 47, Suppl. A (2006); http://jrr.jstage.jst.go.jp, 2005-03-09) Stepanenko, Valeriy F.
The paper is an analytical overview of the main results presented at the 3 rd Dosimetry Workshop in Hiroshima (9–11 of March 2005), where different aspects of the dose reconstruction around the Semipalatinsk nuclear test site (SNTS) were discussed and summarized.
Open Access
Assessing reproducibility of matrix factorization methods in independent transcriptomes
(OXFORD UNIV PRESS, 2019) Cantini, Laura; Kairov, Ulykbek; de Reynies, Aurelien; Barillot, Emmanuel; Radvanyi, Francois; Zinovyev, Andrei
Motivation Matrix factorization (MF) methods are widely used in order to reduce dimensionality of transcriptomic datasets to the action of few hidden factors (metagenes). MF algorithms have never been compared based on the between-datasets reproducibility of their outputs in similar independent datasets. Lack of this knowledge might have a crucial impact when generalizing the predictions made in a study to others. Results We systematically test widely used MF methods on several transcriptomic datasets collected from the same cancer type (14 colorectal, 8 breast and 4 ovarian cancer transcriptomic datasets). Inspired by concepts of evolutionary bioinformatics, we design a novel framework based on Reciprocally Best Hit (RBH) graphs in order to benchmark the MF methods for their ability to produce generalizable components. We show that a particular protocol of application of independent component analysis (ICA), accompanied by a stabilization procedure, leads to a significant increase in the between-datasets reproducibility. Moreover, we show that the signals detected through this method are systematically more interpretable than those of other standard methods. We developed a user-friendly tool for performing the Stabilized ICA-based RBH meta-analysis. We apply this methodology to the study of colorectal cancer (CRC) for which 14 independent transcriptomic datasets can be collected. The resulting RBH graph maps the landscape of interconnected factors associated to biological processes or to technological artifacts. These factors can be used as clinical biomarkers or robust and tumor-type specific transcriptomic signatures of tumoral cells or tumoral microenvironment. Their intensities in different samples shed light on the mechanistic basis of CRC molecular subtyping. Availability and implementation The RBH construction tool is available from http://goo.gl/DzpwYp Supplementary information Supplementary data are available at Bioinformatics online.
Open Access
ASSESSMENT OF BIOCLIMATIC CHANGE IN KAZAKHSTAN, END 20TH-MIDDLE 21ST CENTURIES, ACCORDING TO THE PRECIS PREDICTION
(Public Library of Science, 2020-10-02) Lopez Fernandez, Maria Luisa; Zhumabayev, Dauren; Marco Garcia, Ricardo; Baigarin, Kanat; Lopez Fernandez, Maria Soledad; Baisholanov, Saken
We evaluate bioclimatic changes in Kazakhstan from the end of the 20th century until the middle of the 21st century to offer natural resource managers a tool that facilitates their decision-making on measures to adapt agriculture and environmental care to foreseeable climate change. We use climatic data from the “Providing REgional Climates for Impact Studies” (PRECIS) prediction and study them following the Worldwide Bioclimatic Classification System (WBCS) of Rivas-Martínez. For three 25-year intervals (1980–2004, 2010–2034 and 2035–2059), we identify the continentality, macrobioclimates, bioclimates, bioclimatic variants, thermotypes, ombrotypes and isobioclimates of the study area. The results of the work allow us to: locate the territories where bioclimatic conditions will change, quantify the magnitude of the predicted climate changes, and determine the trends of predictable climate change. We present the results in maps, tables and graphs. For the 80-year interval, we identify 3 macroclimates, 3 bioclimatic variants, 10 bioclimates, 11 thermotypes, 10 ombrotypes and 43 isobioclimates. Some of those found bioclimates, thermotypes, ombrotypes and isobioclimates are only located in the E, SE and S mountains, where they occupy very small areas, that decrease in a generalized way as the 20th century progresses. Comparing the three successive periods, the following trends are observed: 36.2% of the territory increases in thermicity; 7.3% of the territory increases in continentality; 9.7% of the territory increases in annual aridity; 9.5% of the territory increases in summer aridity or mediterraneity; and generalized losses occur in the areas of all mountain isobioclimates. The climate change foreseen by the PRECIS model for the middle of the 21st century leads to bioclimatic homogenization, with 20.8% losses in bioclimatic diversity. We indicate on maps the locations of all the predicted bioclimatic changes; these maps may provide decision makers with a scientific basis to take necessary adaptation measures.
Open Access
ASSESSMENT OF PERSONNEL DOSE BURDEN AND QUALITY OF OPERATIONAL PARAMETERS OF X-RAY RADIOLOGICAL EQUIPMENT OF MEDICAL ORGANIZATIONS OF THE NUR-SULTAN CITY
(International conference "MODERN PERSPECTIVES FOR BIOMEDICAL SCIENCES: FROM BENCH TO BEDSIDE”; National Laboratory Astana, 2020) Bakhtin, M.M.; Kashkinbaev, Ye.T.; Aumalikova, M.N.; Ibrayeva, D.S.; Sharipov, M.K.; Kazymbet, P.K.
Introduction: The results of the assessment of the radiation situation of the workplace, the dose burden of medical personnel, as well as the results of monitoring the operational parameters of X-ray radiological units of medical organizations in Nur-Sultan city are presented. Methods: Personnel dosimetric control measured with TLD, monitoring of operational parameters of X-ray diagnostic equipment at the Piranha dosimeter. Results: The average annual effective dose for X-ray diagnostic department workers is 0.72mSv, for intervention department workers it is 1.27mSv, which in permissible level. At workplaces of the Department of Radiology and Nuclear Medicine, the dose rate of X-ray radiation varies from 0.01μSv/h to 0.04μSv/h. At the workplaces of the personnel of the catheterization department, the X-ray dose rate varies from 0.01μSv/h to 0.91μSv/h, which does not exceed the standard value. According to the results of monitoring operational parameters in 2radiographic and 3 fluoroscopic devices, deviations from the image quality standard were revealed. The difference between the edges of the light and radiation fields exceeded 1.5 to 2times the permissible value. The divergence of the edges of the light and radiation fields leads to irradiation of the undiagnosed zones of the body and neighboring internal organs. The deviation of the perpendicularity of the beam exceeded the permissible value of 1.5°. Deviation of the perpendicularity of the beam affects the incorrect diagnosis, as the displacement of organs. In the mammography apparatus, the difference between the edges of the light and radiation fields exceeded the permissible value by 3 times. During the research, traces of scratching the compression spoon were found in the images in the mammography apparatus of a pure phantom. When monitoring the compression force of compression of the mammography apparatus, the parameter maximum force of automatic compression exceeded the permissible value. Values of the parameters of the anode voltage, radiation yield and dose linearity as dose repeatability in radiographic, fluoroscopic, angiographic and mammographic devices in permissible value. Conclusion. The revealed deviations in the operational parameters of medical X-ray equipment indicates the need for periodic monitoring to identify technical malfunctions, as reduce the high dose burden for patients and medical personnel.
Open Access
ASSOCIATIONS OF SMARTPHONE USE WITH NEUROPSYCHOLOGICAL FUNCTION AND REWARD SENSITIVITY IN UNIVERSITY STUDENTS: IMPLICATIONS FOR PSYCHOLOGICAL HEALTH
(International conference "MODERN PERSPECTIVES FOR BIOMEDICAL SCIENCES: FROM BENCH TO BEDSIDE”; National Laboratory Astana, 2020) Pluck, Graham; Schmidt, Nicole A.; Rodriguez, Wilmary; Hidalgo, Daniela Arcos; Falconi, Pablo Barrera
Introduction: Smartphone use provides unprecedented levels of interpersonal communication and access to information. Constant presence of the technology permits frequent and prolonged use, providing social reward signals and competing for attention with non-online life. University students typically spend over 6 hours per day directly interacting with smartphones, more than one-third of their entire time spent awake, and can potentially receive unsolicited alerts and feedback over the entire 24-hour cycle. This represents a significant increase in how people are exposed to attention demanding stimuli and social reinforcement signals, and potentially could be associated with changes to cognitive ability, and to dependence. Methods: We investigated reward processing and neuropsychological functioning in a sample of 121undergraduate students in Quito, Ecuador. Reward sensitivity was assessed with a laboratory psychomotor task performed with and without financial rewards. The neuropsychological assessment focused on reasoning, executive function, sustained attention and social cognition. Participants completed a psychometric questionnaire on problematic phone use and were observed to derive measures of frequency of phone checking behavior and of the number of messenger services used. Correlations between smartphone use variables and reward and neuropsychological function were examined. Nuisance variables were controlled for with partial correlations. Results: Keeping a smartphone close at hand and frequent checking was associated with worse performance on neuropsychological tests of reasoning and sustained attention. There were no associations with other cognitive or social-cognitive functions. Sensitivity to rewards, a known risk-factor for addiction, was positively correlated with the use of messenger services. There were no associations with the psychometric measure of smartphone use. Conclusion: Smartphone use, particularly compulsive use such as frequent checking, is associated with poor cognitive functioning. This finding contributes to a small body of research suggesting that a consequence of continuous presence of this technology may be reduced analytical reasoning and ability to sustain attention. The use of multiple messenger services is associated with high reward sensitivity, which is a known risk factor for substance dependence, and may thus constitute a risk factor for smartphone addiction.
Open Access
Atomic Force Microscopy Study of Cross-Sections of Perovskite Layers
(EURASIAN CHEMICO-TECHNOLOGICAL JOURNAL, 2019) Migunov, D.; Eidelman, K.; Kozmin, A.; Saranin, D.; Ermanova, I.; Gudkov, D.; Alekseev, A.
Improvement of methods for imaging of the volume structure of photoactive layers is one of the important directions towards development of highly efficient solar cells. In particular, volume structure of photoactive layer has critical influence on perovskite solar cell performance and life time. In this study, a perovskite photoactive layer cross-section was prepared by using Focused Ion Beam (FIB) and imaged by Atomic Force Microscopy (AFM) methods. The proposed approach allows using advances of AFM for imaging structure of perovskites in volume. Two different types of perovskite layers was investigated: FAPbBr(3) and MAPbBr(3). The heterogeneous structure inside film, which consist of large crystals penetrating the film as well as small particles with sizes of several tens nanometers, is typical for FAPbBr(3). The ordered nanocrystalline structure with nanocrystals oriented at 45 degree to film surface is observed in MAPbBr(3). An optimized sample preparation route, which includes FIB surface polishing by low energy Ga ions at the angles around 10 degree to surface plane, is described and optimal parameters of surface treatment are discussed. Use of AFM phase contrast method provides high contrast imaging of perovskite structure due to strong dependence of phase shift of oscillating probe on materials properties. The described method of imaging can be used for controllable tuning of perovskite structure by changes of the sample preparation routes....
Open Access
Behavior and food consumption pattern of the population exposed in 1949–1962 to fallout from Semipalatinsk nuclear test site in Kazakhstan
(Radiation and Environmental Biophysics, 2011-03) Drozdovitch, Vladimir; Schonfeld, Sara; Akimzhanov, Kuat; Aldyngurov, Daulet; Land, Charles E.; Luckyanov, Nickolas; Mabuchi, Kiyohiko; Potischman, Nancy; J. Schwerin, Michael J.; Semenova, Yulia; Tokaeva, Alma; Zhumadilov, Zhaxybay; Bouville, André; Simon, Steven L.
The relationship between radiation exposure from nuclear weapons testing fallout and thyroid disease in a group of 2,994 subjects has been the subject of study by the US National Cancer Institute. In that study, radiation doses to the thyroid were estimated for residents of villages in Kazakhstan possibly exposed to deposition of radioactive fallout from nuclear testing conducted by the Soviet Union at the Semipalatinsk Nuclear Test Site in Kazakhstan between 1949 and 1962. The study subjects included individuals of both Kazakh and Russian origin who were exposed during childhood and adolescence. An initial dose reconstruction used for the risk analysis of Land et al. (Radiat Res 169:373-383, 2008) was based on individual information collected from basic questionnaires administered to the study population in 1998. However, because data on several key questions for accurately estimating doses were not obtained from the 1998 questionnaires, it was decided to conduct a second data collection campaign in 2007. Due to the many years elapsed since exposure, a well-developed strategy was necessary to encourage accurate memory recall.
Open Access
BIOMASS-DERIVED POROUS CARBON FROM AGAR AS AN ANODE MATERIAL FOR LITHIUM-ION BATTERIES
(MDPI, 2021-12-22) Issatayev, Nurbolat; Kalimuldina, Gulnur; Nurpeissova, Arailym; Bakenov, Zhumabay
New porous activated carbons with a high surface area as an anode material for lithium-ion batteries (LIBs) were synthesized by a one-step, sustainable, and environmentally friendly method. Four chemical activators—H2SO4, H3PO4, KOH, and ZnCl2—have been investigated as facilitators of the formation of the porous structure of activated carbon (AC) from an agar precursor. The study of the materials by Brunauer–Emmett–Teller (BET) and scanning electron microscopy (SEM) methods revealed its highly porous meso- and macro-structure. Among the used chemical activators, the AC prepared with the addition of KOH demonstrated the best electrochemical performance upon its reaction with lithium metal. The initial discharge capacity reached 931 mAh g−1 and a reversible capacity of 320 mAh g−1 was maintained over 100 cycles at 0.1 C. High rate cycling tests up to 10 C demonstrated stable cycling performance of the AC from agar.
Open Access
Bonghan Ducts as Possible Pathways for Cancer Metastasis
(Journal of Acupuncture and Meridian Studies, 2009-04-01) Yoo, Jung Sun; Kim, Hong Bae; Ogay, Vyacheslav; Lee, Byung-Cheon; Ahn, Saeyoung; Soh, Kwang-sup
Objective: The present study has been designed to find a possible new route for the metastasis of cancer cells on the fascia surrounding tumor tissue using a novel technique of trypan blue staining. Materials and Methods: Tumor tissues were grown in the skin of nude mice after subcutaneous inoculation with human lung cancer cells. Trypan blue was recently identified as a dye with specificity for Bonghan ducts (BHDs) and not other tissues, such as blood or lymph vessels or nerves. Results: We demonstrate that the trypan blue staining technique allows the first visualization of BHDs which are connected to tumor tissues.
Open Access
Calculation of Water Wheel Design Parameters for Micro Hydroelectric Power Station
(EDP Sciences, 2019-05-29) Kodirov, Dilshod; Tursunov, O
This paper is devoted to the issues such as modelling the design parameters and operating modes and improving the design of micro hydroelectric power plants operating in low-pressure water flow. Taking into consideration above-mentioned issues, it is possible to increase the efficiency of using low-pressure water energy systems. The main dimensions of the water wheel of a micro hydropower plant depend on the water flow velocity v, water volume Q, acting at a fixed point in time on the water wheel blade, and also on the depth of the water level H.
Open Access
Cancer-related genes in the transcription signature of facioscapulohumeral dystrophy myoblasts and myotubes
(Journal of Cellular and Molecular Medicine, 2013) Dmitriev, Petr; Kairov, Ulykbek; Robert, Thomas; Barat, Ana; Lazar, Vladimir; Carnac, Gilles; Laoudj-Chenivesse, Dalila; Vassetzky, Yegor S.
Muscular dystrophy is a condition potentially predisposing for cancer; however, currently, only Myotonic dystrophy patients are known to have a higher risk of cancer. Here, we have searched for a link between facioscapulohumeral dystrophy (FSHD) and cancer by comparing published transcriptome signatures of FSHD and various malignant tumours and have found a significant enrichment of cancer-related genes among the genes differentially expressed in FSHD. The analysis has shown that gene expression profiles of FSHD myoblasts and myotubes resemble that of Ewing’s sarcoma more than that of other cancer types tested. This is the first study demonstrating a similarity between FSHD and cancer cell expression profiles, a finding that might indicate the existence of a common step in the pathogenesis of these two diseases.