003.01. National Laboratory Astana
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Item Open Access A design for large-area fast photo-detectors with transmission-line readout and waveform sampling(In Real Time Conference, 2009. RT'09. 16th IEEE-NPSS (pp. 49-61). IEEE., 2009) Adams, B.; Anderson, J. T.; Attenkofer, K.; Bogdan, M.; Byrum, K.; Drake, G.; Insepov, Z.We present a preliminary design and the results of simulation for a photo-detector module to be used in applications requiring the coverage of areas of many square meters with time resolutions less than 10 picoseconds and position resolutions of less than a millimeter for charged particles. The source of light is Cherenkov light in a radiator/window; the amplification is provided by panels of micro-pores functionalized to act as microchannel plates (MCPs). The good time and position resolution stems from the use of an array of parallel 50 Ω transmission lines (strips) as the collecting anodes. The anode strips feed multi-GS/sec sampling chips which digitize the pulse waveform at each end of the strip, allowing a measurement of the time from the average of the two ends, and a 2-dimensional position measurement from the difference of times on a strip, and, in the orthogonal direction, the strip number, or a centroid of the charges deposited on adjacent strips. The module design is constructed so that large areas can be `tiled' by an array of modules.Item Open Access A General Model of Vacuum Arcs in Linacs(Proceedings of NAPAC2016, Chicago, IL, USA, 2017-01) Norem, J.; Insepov, Z.We are developing a general model of breakdown and gradient limits that applies to accelerators, along with other high field applications such as power grids and laser ablation. We have considered connections with failure modes of integrated circuits, sheath properties of dense, non-Debye plasmas and applications of capillary wave theory to rf breakdown in linacs. In contrast to much of the rf breakdown effort that considers one physical mechanism or one experimental geometry, we find an enormous volume of relevant material in the literature that helps to constrain our model and suggest experimental tests.Item Open Access A Low-Cost Open-Source 3-D-Printed Three-Finger Gripper Platform for Research and Educational Purposes(IEEE Access, 2015-06-02) Telegenov, Kuat; Tlegenov, Yedige; Shintemirov, AlmasRobotics research and education have gained significant attention in recent years due to increased development and commercial deployment of industrial and service robots. A majority of researchers working on robot grasping and object manipulation tend to utilize commercially available robot-manipulators equipped with various end effectors for experimental studies. However, commercially available robotic grippers are often expensive and are not easy to modify for specific purposes. To extend the choice of robotic end effectors freely available to researchers and educators, we present an open-source lowcost three-finger robotic gripper platform for research and educational purposes. The 3-D design model of the gripper is presented and manufactured with a minimal number of 3-D-printed components and an off-the-shelf servo actuator. An underactuated finger and gear train mechanism, with an overall gripper assembly design, are described in detail, followed by illustrations and a discussion of the gripper grasping performance and possible gripper platform modifications. The presented open-source gripper platform computer-aided design model is released for downloading on the authors research lab website(www.alaris.kz) and can be utilized by robotics researchers and educators as a design platform to build their own robotic end effector solutions for research and educational purposes.Item Open Access A model of rf breakdown arcs(Fermilab, 2008) Insepov, Z.; Bross, A.; Qian, Z.; Norem, J.; Huang, D.; Veitzer, S.; Torun, Y.This paper presents a rst iteration of a model that attempts to describe all aspects of breakdown in rf cavities and provides some estimates of the parameters and parameter ranges involved, as an aid to producing more precise models and more useful experiments. The model describes how breakdown events can be triggered, how they grow, it identi es the power source for their rapid growth, mechanisms that limit their growth, how they are extinguished and how they can be mitigated. We also discuss applications to superconducting rf and high pressure gas structures. The model relies heavily on previous experiments with 805 and 201 MHz warm copper cavities, and pre-liminary plasma modeling using the code OOPIC Pro. We compare estimates from the model with experimental data where this is possible. Because of the geometrical dependence of all parameters, the wide range of experiments being performed, the wide range of experimental parameters in a given breakdown event and the lack of extensive systematic parameter searches at this stage in our studies, it is diffcult to present precise results. We are constrained to showing what mechanisms are involved, the strength of these mechanisms and how they interact to produce the experimental data. We are primarily interested in the development and dynamics of the arc, magnetic and gas effects and insights on how to avoid arcing in all environments.Item Open Access A New Multiscale Approach to Nuclear Fuel Simulations: Atomistic Validation of Kinetic Method(Transactions of the American Nuclear Society, 2010) Insepov, Z.; Rest, J.; Hofman, G. L.; Yacout, A.; Norman, G. E.; Starikov, S. A.; Stegailov, V. V.A key issue for fuel behavior codes is their sensitivity to values of various materials properties, many of which have large uncertainties or have not been measured. Kinetic mesoscale models, such as those developed at Argonne National Laboratory within the past decade, are directly comparable to data obtained from in-reactor experiments. In the present paper, a new multiscale concept is proposed that consists of using atomistic simulation methods to verify the kinetic approach. The new concept includes kinetic rate-equations for radiation damage, energetics and kinetics of defects, and gas/defect-driven swelling of fuels as a function of temperature and burnup. The quantum and classical atomistic simulation methods are applied to increase our understanding of radiation damage and defect formation and growth processes and to calculate the probabilities of elemental processes and reactions that are applicable to irradiated nuclear materials.Item 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, ZhumabayA 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...Item Metadata only Aberrant base excision repair pathway of oxidatively damaged DNA: Implications for degenerative diseases(Free Radical Biology and Medicine, 2017-06-01) Talhaoui, Ibtissam; Matkarimov, Bakhyt T.; Tchenio, Thierry; Zharkov, Dmitry O.; Saparbaev, Murat K.; Ibtissam, TalhaouiAbstract In cellular organisms composition of DNA is constrained to only four nucleobases A, G, T and C, except for minor DNA base modifications such as methylation which serves for defence against foreign DNA or gene expression regulation. Interestingly, this severe evolutionary constraint among other things demands DNA repair systems to discriminate between regular and modified bases. DNA glycosylases specifically recognize and excise damaged bases among vast majority of regular bases in the base excision repair (BER) pathway. However, the mismatched base pairs in DNA can occur from a 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. Mismatch-specific adenine- and thymine-DNA glycosylases (MutY/MUTYH and TDG/MBD4, respectively) initiated BER and mismatch repair (MMR) pathways can recognize and remove normal DNA bases in mismatched DNA duplexes. Importantly, in DNA repair deficient cells bacterial MutY, human TDG and mammalian MMR can act in the aberrant manner: MutY and TDG removes adenine and thymine opposite misincorporated 8-oxoguanine and damaged adenine, respectively, whereas MMR removes thymine opposite to O6-methylguanine. 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 aberrant manner and introduce genome instability in the presence of unrepaired DNA lesions. Evidences accumulated showing that in addition to the accumulation of oxidatively damaged DNA in cells, the aberrant DNA repair can also contribute to cancer, brain disorders and premature senescence. For example, the aberrant BER and MMR pathways for oxidized guanine residues can lead to trinucleotide expansion that underlies Huntington's disease, a severe hereditary neurodegenerative syndrome. This review summarises the present knowledge about the aberrant DNA repair pathways for oxidized base modifications and their possible role in age-related diseases.Item 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.Item 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.Item Open Access Aberrant repair initiated by the adenine-DNA glycosylase does not play a role in UV-induced mutagenesis in Escherichia coli(BIOCHEMISTRY, BIOPHYSICS AND MOLECULAR BIOLOGY, 2018-12-15) Zutterling, Caroline; Mursalimov, Aibek; alhaoui, Ibtissam; Koshenov, Zhanat; Akishev, Zhiger; Bissenbaev, Amangeldy K.; Mazon, Gerard; Geacintov, Nicolas E.; Gasparutto, Didier; Groisman, Regina; Zharkov, Dmitry O.; Matkarimov, Bakhyt T.; Saparbaev, MuratDNA repair is essential to counteract damage to DNA induced by endo- and exogenous factors, to maintain genome stability. However, challenges to the faithful discrimination between damaged and non-damaged DNA strands do exist, such as mismatched pairs between two regular bases resulting from spontaneous deamination of 5-methylcytosine or DNA polymerase errors during replication. To counteract these mutagenic threats to genome stability, cells evolved the mismatch-specific DNA glycosylases that can recognize and remove regular DNA bases in the mismatched DNA duplexes. The Escherichia coli adenine-DNA glycosylase (MutY/MicA) protects cells against oxidative stress-induced mutagenesis by removing adenine which is mispaired with 7,8-dihydro-8-oxoguanine (8oxoG) in the base excision repair pathway....Item Open Access Acoustoelectric properties of graphene under the influence of saw and external electric field(Nazarbayev University, NURIS, Institute of Microelectronics Technology and High Purity Materials, 2015) Insepov, Z.; Tynyshtykbayev, Kurbangali B.; Kononenko, Oleg V.; Roshchupkin, Dmitry V.The effect of SAW on the electrical properties of the few-layer (2-3 layers) graphene is studied. Under the influence of SAW the appearence of acoustoelectric current IAEC in graphene is observed. The sign and magnitude of the induced IAEC in graphene conditioned by magnitude and direction of the electromagnetic fields induced by SAW and an external electric field. When the direction of SAW and Vbias is the same IAEC amplified, when at the opposite direction - IAEC are reduced in result of the interaction of these fields with each other. As a result of the measurement of the induced acoustoelectric (IAEC) current in graphene under the influence of a surface acoustic wave (SAW) the fluctuation nature of acoustoelectric current in the area of electrical neutrality is established at low voltages of an external bias (Vbias) applied on a graphene. The fluctuation character of the IAEC is manifested in all cases of measurements depending on the action of SAW and Vbias near the point of electrical neutrality. Chaotic fluctuation potential of graphene in the area of electrical neutrality is enhanced by the action of SAW that allows observing it in real conditions of the experiment at room temperature in air. The magnitude of IAEC depends on the power of SAW, while there is a parabolic dependence of the induced IAEC on the amplification current of SAW power (ISAW). The parabolic dependence of IAEC on ISAW explained by specific relaxation of acoustic phonons of the piezocrystallical substrate, which is dominant in the process of electronphonon scattering in graphene and acoustoelectric current induction in it. For large magnitudes of Vbias strict linear dependence of the IAEC on Vbias is observed. Large Vbias effectively suppress the appearance of the fluctuation potential of electrons and holes. The ability to control the magnitude and direction of IAEC induced in graphene by SAW is of practical importance.Item Open Access ACTIVATED CARBON/PECTIN COMPOSITE ENTEROSORBENT FOR HUMAN PROTECTION FROM INTOXICATION WITH XENOBIOTICS PB(II) AND SODIUM DICLOFENAC(Molecules, 2022) Jandosov, Jakpar; Alavijeh, Mo; Sultakhan, Shynggyskhan; Baimenov, Alzhan; Bernardo, Maria; Sakipova, Zuriyadda; Azat, Seytkhan; Lyubchyk, Svitlana; Zhylybayeva, Nurzhamal; Naurzbayeva, Gulmira; Mansurov, Zulkhair; Mikhalovsky, Sergey; Berillo, DmitriyThe use of enterosorbents—materials which can be administered orally and eliminate toxic substances from the gastrointestinal tract (GIT) by sorption—offers an attractive complementary protection of humans against acute and chronic poisoning. In this study, we report the results of developing a microgranulated binary biomedical preparation for oral use. It was designed with a core-shell structure based on pectin with low degree of esterification as the core, and nanoporous activated carbon produced from rice husk, AC-RH, as the shell, designated as AC-RH@pectin. The adsorption properties of the synthesized materials were studied in aqueous solutions for the removal of lead (II) nitrate as a representative of toxic polyvalent metals and sodium diclofenac as an example of a medicinal drug. The composite enterosorbent demonstrated high adsorption capacity for both adsorbates studied. Adsorption kinetics of lead and diclofenac adsorption by AC-RH, pectin, and AC-RH@pectin, fitted well a pseudo-second-order model. According to the Langmuir adsorption isotherm model, the best fitted isotherm model, the maximum adsorption capacity, qmax, of AC RH@pectin for diclofenac and for lead (II) was 130.9 mg/g and 227.8 mg/g, respectively. Although qmax of AC-RH for diclofenac, 537.6 mg/g, and qmax of pectin for lead (II), 245.7 mg/g, were higher, the maximum adsorption capacity of AC-RH for lead (II), 52.7 mg/g, was much lower than that of the composite AC-RH@pectin and the adsorption capacity of pectin for diclofenac was negligible. Therefore, the composite material AC-RH@pectin demonstrated substantial efficiency of removing both species which potentially defines it as a more universal enterosorbent suitable for treating poisoning caused by substances of different chemical nature.Item Metadata only Adipose-derived perivascular stem cells promote sensorimotor recovery after ischemic stroke in rats(Journal of Biotechnology, 2017-08-30) Ogay, Vyacheslav; Kumasheva, Venera; Baidosova, Sholpan; Li, Yelena; Shpekov, Azat; Makhambetov, Yerbol; Kaliyev, Assylbek; Zhetpisbayev, Berik; Olzhayev, Farkhad; Ramankulov, Yerlan; Vyacheslav, OgayIn this study, we test a novel hypothesis that treatment of stroke with adipose-derived perivascular stem cells (PSCs) promote sensorimotor recovery after stroke in rats. Rat PSCs were isolated from subcutaneous adipose tissue by a FACS Aria cell sorter using antibodies against CD146, CD31, CD34 and CD45. Isolated and propagated PSCs exhibited fibroblast-like morphology and significantly expressed both mesenchymal stem cells and pericyte markers such as CD73, CD90, CD105, CD146, NG2 and PDGFR-β. Adult male Wistar rats were subjected to 2 h of middle cerebral artery occlusion (MCAo) followed by femoral vein injection of PSCs (3 × 106 cells) 24 h later. The rats were sacrificed at 28 days after stroke and immunohistochemistry were performed to identify angiogenesis. It was observed that intravenous injection of PSCs significantly promoted sensomotoric recovery in stroke rats compared with PBS-treated controls. Number of blood capillaries was significantly increased along the ischemic boundary zone of the cortex and striatum in MCAo rats treated with PSCs.Item Open Access Advanced Surface Polishing For Accelerator Technology Using Ion Beams(American Institute of Physics, 2009-03) Insepov, Z.; Norem, J.; Hassanein, A.; Wu, A. T.Surface erosion problems are common in the development of TeV accelerators, fusion and fission reactors, semiconductor, optical and magnetic storage devices, and Extreme Ultra-Violet (EUV) lithography devices. We have reviewed various erosion mechanisms of ion interactions with the surfaces studied by experiment and computer simulation. Nanoscale surface roughness in rf-linacs and contamination cause field emission of electrons, field evaporation of ions and fragments, plasma formation, and lead to high-gradient rf vacuum breakdown of electrodes which is a limiting factor in the development of high-gradient rf technology for future TeV accelerators. A few mechanisms of nanoscale surface fracture under a high-gradient electric field were developed and will be discussed. A Gas Cluster Ion Beam (GCIB) technology was successfully applied to surface treatment of Cu, Stainless steel, Ti and Nb samples and to Nb rf-cavities by using accelerated cluster ion beams of Ar, O2, N2, and NF3, and combinations of them, with accelerating voltages up to 35 kV. DC field emission (dark current) measurements and electron microscopy were used to investigate metal surfaces treated by GCIB. The experimental results showed that GCIB technique can significantly reduce the number of field emitters and also change the structure of the Nb oxide layer on the surface. The RF tests on the GCIB treated Nb rf-cavities showed improvement of the quality factor Q at 4.5 K. The superconducting gap was also enhanced by using the oxygen GCIB irradiation exposure. GCIB may become a standard technique to modify and control the oxygen content on the surface and a promising surface treatment technique for Nb SRF cavities in particle accelerators. Computer simulation of bombardment of Nb surfaces with Ar and O2 clusters by molecular dynamics and phenomenological surface dynamics equations confirms experimental results.Item 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.Item 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-Razakir 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.Item 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.Item 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, YerlanOur 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.Item Open Access ANCIENT COMPONENTS AND RECENT EXPANSION IN THE EURASIAN HEARTLAND: INSIGHTS INTO THE REVISED PHYLOGENY OF Y-CHROMOSOMES FROM CENTRAL ASIA(Genes, 2022) Zhabagin, Maxat; Wei, Lan-Hai; Sabitov, Zhaxylyk; Ma, Peng-Cheng; Sun, Jin; Dyussenova, Zhanargul; Balanovska, Elena; Li, Hui; Ramankulov, YerlanIn the past two decades, studies of Y chromosomal single nucleotide polymorphisms (YSNPs) and short tandem repeats (Y-STRs) have shed light on the demographic history of Central Asia, the heartland of Eurasia. However, complex patterns of migration and admixture have complicated population genetic studies in Central Asia. Here, we sequenced and analyzed the Y-chromosomes of 187 male individuals from Kazakh, Kyrgyz, Uzbek, Karakalpak, Hazara, Karluk, Tajik, Uyghur, Dungan, and Turkmen populations. High diversity and admixture from peripheral areas of Eurasia were observed among the paternal gene pool of these populations. This general pattern can be largely attributed to the activities of ancient people in four periods, including the Neolithic farmers, Indo-Europeans, Turks, and Mongols. Most importantly, we detected the consistent expansion of many minor lineages over the past thousand years, which may correspond directly to the formation of modern populations in these regions. The newly discovered sub-lineages and variants provide a basis for further studies of the contributions of minor lineages to the formation of modern populations in Central Asia.Item Open Access Anticancer Effects and uses of Melatonin A Review(Austin Journal of Cancer and Clinical Research, 2015-08) Mektepbayeva, Damel; Alibek, Kenneth; Atinbayeva, N.; Irving, S; Zhaisanbayeva, B; Mussurova, S; Mussakhan, SMelatonin (N-acetyl-5-methoxytryptamine, MLT) is a naturally occurring hormone secreted by the pineal gland. Clinical evidence suggests that MLT may have a possible role in the treatment of cancer, where MLT presents many oncostatic properties in a wide variety of tumors, utilizing multiple and converging mechanisms. It is a potent anti-oxidative agent; its circadian rhythm-regulating properties are crucial for orchestrating patterns of hormone secretion, the imbalance of which is implicated in a wide range of hormonedependent cancers of the reproductive organs. Recent advances in cancer treatment can offer therapeutic alternatives that could reduce the severity of unwanted side effects. Several observational studies have demonstrated a relationship between long-term disruption of circadian rhythm with decreased MLT secretion and increased cancer risk, whilst clinical evidence supports the possible benefits from MLT on the survival in patients with a range of cancers. This review will address some of the multiple anticancer properties of MLT, with a particular focus on the mechanisms counteracting tumor occurrence, growth, and development. Recent research into the oncostatic effects of MLT and the mechanisms of action explaining its efficiency for tumor regulation are summarized in this review and suggestions for the therapeutic use of MLT will be presented.