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Item Open Access Aluminum foil as a substrate for metal enhanced fluorescence of bacteria labelled with quantum dots, shows very large enhancement and high contrast(Elsevier, 2020-02-21) Sultangaziyev, Alisher; Akhmetova, Aktilek; Kunushpayeva, Zhanar; Rapikov, Alisher; Olena, Filchakova; Bukasov, RostislavVery high surface/metal enhanced fluorescence was observed for E. coli single bacteria cells labeled with composite CdSeS/ZnS quantum dots (QDs) on three substrates: aluminum foil, aluminum film and gold film. The enhancement factors relative to maximum fluorescence intensity on glass for those substrates were in the range of several hundred (up to 500) for two-excitation wavelengths 532 and 633 nm. Contrast as a ratio of signals from QD labeled to signals of QD unlabeled (control) cells was also in the range of 100 s for those substrates and the highest contrast of 370 was observed on Al film. When CdTe QDs were used for labelling cells on all substrates or when fluorescence from cells with both QDs was measured on silver film, low or no enhancement was observed. Overall, untreated aluminum foil demonstrated great potential as low-cost substrate for surface/metal enhanced fluorescence, which delivers even more reproducible signal than gold film.Item Open Access ANTIMOULD ACTION OF ZIRAM AND IPBC LOADED IN FUNCTIONALISED NANOGELS AGAINST ASPERGILLUS NIGER AND PENICILLIUM CHRYSOGENUM(Materials Advances, 2022) Raimond, Laurine; Halbus, Ahmed F.; Athab, Zahraa H.; Paunov, Vesselin N.We explore the antimould action of zinc bis(dimethyldithiocarbamate) (Ziram) and 3-iodo-2-propynyl N-butylcarbamate (IPBC) encapsulated into nanogel particles with and without surface functionalization with a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDAC). The antimould nanocarriers were based on commercially available polyacrylic copolymeric nanogel. The antimould agents were loaded into the nanogel particles in their swollen state in alkaline media followed by collapsing of the nanogel particles at acidic pH. We treated Aspergillus niger and Penicillium chrysogenum cultures at different concentrations of the nanocarrier-loaded antimould agent. The effect of the surface charge of the antimould agent-loaded nanocarriers was examined in order to gain better understanding of how the electrostatic interaction of the nanocarrier with the cell walls of the mould hyphae and spores impacts its antimould action. Non-coated nanocarriers proved more efficient than PDAC-coated ones in their antimould action for both Ziram and IPBC formulations. Four different methods of application of the antimould nanocarriers were also explored. We found that the application method of the nanogel carrier is crucial for its efficiency and sustained antimould delivery. Pre-mixing the nanogel-formulated Ziram or IPBC with culture media generally produced much better antimould action. Such a strategy can potentially bypass this antimould resistance and lead to novel formulations with highly sustained antimould activity at similar concentrations of the antimould agent. These insights may lead to the development of more efficient antimould treatments at lower concentration of active agent for mould control with potentially substantial economic and environmental benefits.Item Open Access Base Metal Catalysts for Deoxygenative Reduction of Amides to Amines(Nazarbayev University School of Sciences and Humanities, 2019-06-01) Khalimon, Andrey; Gudun, Kristina; Hayrapetyan, DavitThe development of efficient methodologies for production of amines attracts significant attention from synthetic chemists, because amines serve as essential building blocks in the synthesis of many pharmaceuticals, natural products, and agrochemicals. In this regard, deoxygenative reduction of amides to amines by means of transition-metal-catalyzed hydrogenation, hydrosilylation, and hydroboration reactions represents an attractive alternative to conventional wasteful techniques based on stoichiometric reductions of the corresponding amides and imines, and reductive amination of aldehydes with metal hydride reagents. The relatively low electrophilicity of the amide carbonyl group makes this transformation more challenging compared to reduction of other carbonyl compounds, and the majority of the reported catalytic systems employ precious metals such as platinum, rhodium, iridium, and ruthenium. Despite the application of more abundant and environmentally benign base metal (Mn, Fe, Co, and Ni) complexes for deoxygenative reduction of amides have been developed to a lesser extent, such catalytic systems are of great importance. This review is focused on the current achievements in the base-metal-catalyzed deoxygenative hydrogenation, hydrosilylation, and hydroboration of amides to amines. Special attention is paid to the design of base metal catalysts and the mechanisms of such catalytic transformationsItem Open Access A CARBON DOT-BASED CO-NANOZYME WITH ALKALINE PHOSPHATASE – MECHANISM AND APPLICATION(RSC Advances, 2021-10-21) Fan, Haiyan; Dukenbayev, Kanat; Sun, Qinglei; Khamijan, Medina; Turdaliyev, Akhrorbek; Ysmaiyl, Alibek; Tassanbiyeva, Aigerim; Ma, Cuiping; Xie, YingqiuElevated levels of alkaline phosphatase (ALP) are associated with bone metastasis, liver cancer, prostate cancer, breast cancer, and many other diseases or stem cell marker. It is therefore of great significance to quantitatively detect the ALP levels by a rapid, highly sensitive, and easy-to-use strip paper test. In the present work, we discovered an enhancement of ALP activity upon the addition of cauliflower-derived carbon dots (CFCDs), which can be applied as a sensor for ALP. The mixed ALP and CFCDs exhibited a typical Michaelis Menten mechanism with increased Vmax and reduced Km compared to ALP alone. High-Resolution Atomic Force Microscopy (HR-AFM) reveals the dimensions of ALP, the CFCDs, and the phosphatase substrate para-nitrophenyl phosphate (pNPP), as well as the potential interactions among them. The role of the CFCDs was identified as the addition of reaction centers to ALP; in other words, a competitive activator. Besides the improved kinetics, the yield of dephosphorylated product was also increased by at least twice upon the addition of CFCDs. Taking advantage of this effect, a portable CFCD-based paper strip assay was developed to achieve sensitive detection of abnormally elevated ALP levels and visualization of cancer stem cells or proteins by phosphatase-conjugated antibodies. Our findings show great promise for disease diagnosis and bioassays related to ALP enhancement that may be used for protein or cell detection.Item Open Access CARBON DOTS-MEDIATED FLUORESCENT SCAFFOLDS: RECENT TRENDS IN IMAGE-GUIDED TISSUE ENGINEERING APPLICATIONS(MDPI AG, 2021-05-20) Vedhanayagam, Mohan; Raja, Iruthayapandi Selestin; Molkenova, Anara; Atabaev, Timur Sh.; Sreeram, Kalarical Janardhanan; Han, Dong-WookRegeneration of damaged tissues or organs is one of the significant challenges in tissue engineering and regenerative medicine. Many researchers have fabricated various scaffolds to accelerate the tissue regeneration process. However, most of the scaffolds are limited in clinical trials due to scaffold inconsistency, non-biodegradability, and lack of non-invasive techniques to monitor tissue regeneration after implantation. Recently, carbon dots (CDs) mediated fluorescent scaffolds are widely explored for the application of image-guided tissue engineering due to their controlled architecture, light-emitting ability, higher chemical and photostability, excellent biocompatibility, and biodegradability. In this review, we provide an overview of the recent advancement of CDs in terms of their different synthesis methods, tunable physicochemical, mechanical, and optical properties, and their application in tissue engineering. Finally, this review concludes the further research directions that can be explored to apply CDs in tissue engineering.Item Open Access Control of Porphyrin Dye Aggregation Using Bis(4-pyridyl)Alkanes in Dye Sensitized Solar Cells(The Institute of Combustion Problems, 2019-02-02) Baptayev, B.; Rysbekova, Altynay; Kalpakov, Dauren; Aukenova, Ainura; Mustazheb, Dias; Salkenova, Zarina; Kazaliyev, Miras; Balanay, MannixThe aggregation of sensitizer molecules on the surface of photoanode is a serious issue that can affect the photovoltaic performance of dye-sensitized solar cells. Prevention of dye agglomeration, therefore, is critical. Traditional methods of aggregation control are either synthetically challenging or technologically difficult and expensive. In this article, the use of bis(4-pyridyl)alkanes to control porphyrin dye aggregation is presented. Three bis(4-pyridyl)alkanes – bis(4-pyridyl)butane L4, bis(4-pyridyl)octane L8 and bis(4-pyridyl)decane L10 were synthesized. These bis(4-pyridyl)alkane ligands are axially attached to the metallic center of synthesized porphyrin dye P. The complexes was obtained by mixing the solutions of dye P and each ligand (L) in 2:1 ratio 1 h before the soaking step. As a result three cells were prepared: P-L4, P-L8 and P-L10. The performance of these cells were compared with a reference cell which was prepared from porphyrin dye P only. IPCE analysis demonstrated the highest dye load in P-L4 cell which was ascribed to lowered dye aggregation. Photovoltaic analysis showed improved short circuit current density due to suppressed dye aggregation caused by the complexation of the porphyrin dye P with the linker L4. As a result the overall cell efficiency increased to 42% demonstrating the successful utilization of the (4-pyridyl)alkane linker complexes with porphyrin dye.Item Open Access CRACK-FREE AND THICKNESS-CONTROLLABLE DEPOSITION OF TIO2–RGO THIN FILMS FOR SOLAR HARNESSING DEVICES(Coatings, 2022) Khamkhash, Laura; Em, Svetlana; Molkenova, Anara; Hwang, Yoon-Hwae; Atabaev, Timur Sh.The use of thin films consisting of TiO2 and reduced graphene oxide (TiO2–rGO) in solar harnessing devices is gaining momentum thanks to improved charge-transporting characteristics. In this report, we propose a facile spin-coating methodology for the deposition of crack-free and thickness-controllable TiO2–rGO thin films. A range of characterization techniques were utilized to confirm the formation of the TiO2–rGO thin film. Improved charge-transporting properties of TiO2–rGO composite thin films were confirmed by measuring their photoelectrochemical (PEC) activity under simulated solar light illumination. In particular, it was found that the TiO2–rGO composite thin film yielded a better photocurrent response (~151.3 µA/cm2 ) than the bare TiO2 thin film (~71.6 µA/cm2 ) at 1.23 eV vs. the reversible hydrogen electrode (RHE). The obtained results suggested that rGO addition remarkably improves the charge-transporting properties in TiO2 films.Item Open Access Crystal structure of 5,15-bis-(4-methyl-phen-yl)-10,20-bis-(4-nitro-phen-yl)porphyrin nitro-benzene disolvate(Nazarbayev University School of Sciences and Humanities, 2018-01-01) Baptayev, Bakhytzhan; Adilov, SalimgereyThe whole mol-ecule of the title porphyrin, C46H32N6O4·2C6H5NO2, which crystallized as a nitro-benzene disolvate, is generated by inversion symmetry. The porphyrin macrocycle is almost planar, the maximum deviation from the mean plane of the non-hydrogen atoms is 0.097 (2) Å. The aryl rings at the meso positions are inclined to this mean plane by 74.84 (6)° for the nitro-phenyl rings and 73.37 (7)° for the tolyl rings. In the crystal, the porphyrin mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains along [100]. The solvent mol-ecules are also linked by C-H⋯O hydrogen bonds, forming chains along [100]. Inter-digitation of the p-tolyl groups along the c axis creates rectangular channels in which the solvent mol-ecules are located.Item Open Access DETECTION OF RNA VIRUSES FROM INFLUENZA AND HIV TO EBOLA AND SARS-COV-2: A REVIEW(Analytical Methods, 2020-12-07) Bukasov, Rostislav; Dossym, Dina; Filchakova, OlenaRNA-based viruses likely make up the highest pandemic threat among all known pathogens in about the last 100 years, since the Spanish Flu of 1918 with 50 M deaths up to COVID-19. Nowadays, an efficient and affordable testing strategy for such viruses have become the paramount target for the fields of virology and bioanalytical chemistry. The detection of the viruses (influenza, hepatitis, HIV, Zika, SARS, Ebola, SARS-CoV-2, etc.) and human antibodies to these viruses is described and tabulated in terms of the reported methods of detection, time to results, accuracy and specificity, if they are reported. ...Item Open Access DETECTION OF RNA VIRUSES FROM INFLUENZA AND HIV TO EBOLA AND SARS-COV-2: A REVIEW(Royal Society of Chemistry, 2020-12-07) Bukasov, Rostislav; Dossym, Dina; Filchakova, OlenaRNA-based viruses likely make up the highest pandemic threat among all known pathogens in about the last 100 years, since the Spanish Flu of 1918 with 50 M deaths up to COVID-19. Nowadays, an efficient and affordable testing strategy for such viruses have become the paramount target for the fields of virology and bioanalytical chemistry. The detection of the viruses (influenza, hepatitis, HIV, Zika, SARS, Ebola, SARS-CoV-2, etc.) and human antibodies to these viruses is described and tabulated in terms of the reported methods of detection, time to results, accuracy and specificity, if they are reported. The review is focused, but not limited to publications in the last decade. Finally, the limits of detection for each representative publication are tabulated by detection methods and discussed. These methods include PCR, lateral flow immunoassays, LAMP-based methods, ELISA, electrochemical methods (e.g., amperometry, voltammetry), fluorescence spectroscopy, AFM, SPR and SERS spectroscopy, silver staining and CRISPR-Cas based methods, bio-barcode detection, and resonance light scattering. The review is likely to be interesting for various scientists, and particularly helpful with information for establishing interdisciplinary research.Item Open Access Doped Carbon Dots for Sensing and Bioimaging Applications: A Minireview(Nazarbayev University School of Sciences and Humanities, 2018-05-18) Atabaev, TimurIn the last decade, carbon dots (C-dots, CDs) or carbon quantum dots (CQDs) have attracted a considerable amount of attention from the scientific community as a low cost and biocompatible alternative to semiconductor quantum dots. In particular, doped C-dots have excellent fluorescent properties that have been successfully utilized for numerous applications. In this minireview, we overview the recent advances on the synthesis of doped C-dots derived from carbon-rich sources and their potential applications for biomedical and sensing applications. In addition, we will also discuss some challenges and outline some future perspectives of this exciting material.Item Open Access Dysregulation of YAP by ARF Stimulated with Tea-derived Carbon Nanodots(Nazarbayev University School of Sciences and Humanities, 2017-11-29) Xie, Yingqiu; Kauanova, Sholpan; Fan, Haiyan; Sun, Qinglei; Nurkesh, Ayan; Lu, Jiang; Tursynkhan, Darkhan; Yang, Qing; Kassymbek, Aishabibi; Karibayev, Mirat; Duisenova, Korlan; Wang, Xiao; Manarbek, Limara; Maipas, Aisulu; Chen, Zhenbang; Balanay, Mannix P.YAP is a downstream nuclear transcription factor of Hippo pathway which plays an essential role in development, cell growth, organ size and homeostasis. It was previously identified that elevation of YAP in genomics of genetic engineered mouse (GEM) model of prostate cancer is associated with Pten/Trp53 inactivation and ARF elevation hypothesizing the essential crosstalk of AKT/mTOR/YAP with ARF in prostate cancer. However, the detailed function and trafficking of YAP in cancer cells remains unclear. Using GEM microarray model, we found ARF dysregulates Hippo and Wnt pathways. In particular, ARF knockdown reduced non-nuclear localization of YAP which led to an increase in F-actin. Mechanistically, ARF knockdown suppressed protein turnover of β-catenin/YAP, and therefore enhanced the activity of AKT and phosphorylation of YAP. Moreover, we found tea-derived carbon dots can interact with ARF in nucleus that may further lead to the non-nuclear localization of YAP. Thus, we reported a novel crosstalk of ARF/β-catenin dysregulated YAP in Hippo pathway and a new approach to stimulate ARF-mediated signaling to inhibit nuclear YAP using nanomaterials implicating an innovative avenue for treatment of cancer.Item Open Access EDITORIAL: FLUORESCENT CARBON-BASED NANOSTRUCTURES FOR BIOIMAGING APPLICATIONS(Frontiers in Chemistry, 2020-09) Atabaev, Timur Sh.; Han, Dong-WookRecently discovered carbon quantum dots (CQDs) and graphene quantum dots (GQDs) with excellent optical properties sparked considerable interest in the scientific community. First of all, these CQDs and GQDs can be conveniently prepared using green protocols from virtually any carbon-rich media making them more attractive compared to other optical materials. Second, the emission spectrum of CQDs and GQDs can be tuned by controlling the reaction parameters or by incorporation of dopant ions. Finally, low-cost, non-toxic, inert, and photostable CQDs and GQDs already exhibited promising results in areas such as bioimaging, sensing and detection, photocatalysis, energy, and security printing.Item Open Access ENHANCED ANTIMICROBIAL ACTION OF CHLORHEXIDINE LOADED IN SHELLAC NANOPARTICLES WITH CATIONIC SURFACE FUNCTIONALITY(MDPI, 2021-09-02) Al-Obaidy, Saba S. M.; Greenway, Gillian M.; Paunov, Vesselin N.We report on an active nanocarrier for chlorhexidine (CHX) based on sterically stabilized shellac nanoparticles (NPs) with dual surface functionalization, which greatly enhances the antimicrobial action of CHX. The fabrication process for the CHX nanocarrier is based on pH-induced co-precipitation of CHX-DG from an aqueous solution of ammonium shellac and Poloxamer 407 (P407), which serves as a steric stabilizing agent. This is followed by further surface modification with octadecyl trimethyl ammonium bromide (ODTAB) through a solvent change to yield cationic surface functionality. In this study, we assessed the encapsulation efficiency and release kinetics of the novel nanocarrier for CHX. We further examined the antimicrobial effects of the CHX nanocarriers and their individual components in order to gain better insight into how they work, to improve their design and to explore the impacts of their dual functionalization. The antimicrobial actions of CHX loaded in shellac NPs were examined on three different proxy microorganisms: a Gram-negative bacterium (E. coli), a yeast (S. cerevisiae) and a microalgae (C. reinhardtii). The antimicrobial actions of free CHX and CHX-loaded shellac NPs were compared over the same CHX concentration range. We found that the non-coated shellac NPs loaded with CHX showed inferior action compared with free CHX due to their negative surface charge; however, the ODTAB-coated, CHX-loaded shellac NPs strongly amplified the antimicrobial action of the CHX for the tested microorganisms. The enhancement of the CHX antimicrobial action was thought to be due to the increased electrostatic adhesion between the cationic surface of the ODTAB-coated, CHX-loaded shellac NPs and the anionic surface of the cell walls of the microorganisms, ensuring direct delivery of CHX with a high concentration locally on the cell membrane. The novel CHX nanocarriers with enhanced antimicrobial action may potentially find applications in dentistry for the development of more efficient formulations against conditions such as gingivitis, periodontitis and other oral infections, as well as enabling formulations to have lower CHX concentrations. Keywords: antimicrobial nanocarriers; chlorhexidine; shellac; ODTAB; E. coli; yeast; microalgae; nanoparticles; Poloxamer 407Item Open Access ENHANCED ANTIMICROBIAL ACTION OF CHLORHEXIDINE LOADED IN SHELLAC NANOPARTICLES WITH CATIONIC SURFACE FUNCTIONALITY(MDPI, 2021-09-21) Al-Obaidy, Saba S. M.; Greenway, Gillian M.; Paunov, Vesselin N.We report on an active nanocarrier for chlorhexidine (CHX) based on sterically stabilized shellac nanoparticles (NPs) with dual surface functionalization, which greatly enhances the antimicrobial action of CHX. The fabrication process for the CHX nanocarrier is based on pH-induced co-precipitation of CHX-DG from an aqueous solution of ammonium shellac and Poloxamer 407 (P407), which serves as a steric stabilizing agent. This is followed by further surface modification with octadecyl trimethyl ammonium bromide (ODTAB) through a solvent change to yield cationic surface functionality. In this study, we assessed the encapsulation efficiency and release kinetics of the novel nanocarrier for CHX. We further examined the antimicrobial effects of the CHX nanocarriers and their individual components in order to gain better insight into how they work, to improve their design and to explore the impacts of their dual functionalization. The antimicrobial actions of CHX loaded in shellac NPs were examined on three different proxy microorganisms: a Gram-negative bacterium (E. coli), a yeast (S. cerevisiae) and a microalgae (C. reinhardtii). The antimicrobial actions of free CHX and CHX-loaded shellac NPs were compared over the same CHX concentration range. We found that the non-coated shellac NPs loaded with CHX showed inferior action compared with free CHX due to their negative surface charge; however, the ODTAB-coated, CHX-loaded shellac NPs strongly amplified the antimicrobial action of the CHX for the tested microorganisms. The enhancement of the CHX antimicrobial action was thought to be due to the increased electrostatic adhesion between the cationic surface of the ODTAB-coated, CHX-loaded shellac NPs and the anionic surface of the cell walls of the microorganisms, ensuring direct delivery of CHX with a high concentration locally on the cell membrane. The novel CHX nanocarriers with enhanced antimicrobial action may potentially find applications in dentistry for the development of more efficient formulations against conditions such as gingivitis, periodontitis and other oral infections, as well as enabling formulations to have lower CHX concentrations.Item Open Access ENHANCED ANTIMOULD ACTION OF SURFACE MODIFIED COPPER OXIDE NANOPARTICLES WITH PHENYLBORONIC ACID SURFACE FUNCTIONALITY(Biomimetics, 2021-03-15) Henry, Patricia; Halbus, Ahmed F.; Athab, Zahraa H.; Paunov, Vesselin N.Antimould agents are widely used in different applications, such as specialty paints, building materials, wood preservation and crop protection. However, many antimould agents can be toxic to the environment. This work aims to evaluate the application of copper oxide nanoparticles (CuONPs) surface modified with boronic acid (BA) terminal groups as antimould agents. We developed CuONPs grafted with (3-glycidyloxypropyl) trimethoxysilane (GLYMO), coupled with 4-hydroxyphenylboronic acid (4-HPBA), which provided a strong boost of their action as antimould agents. We studied the antimould action of the 4-HPBA-functionalized CuONPs against two mould species: Aspergillus niger (A. niger) and Penicillium chrysogenum (P. chrysogenum). The cis-diol groups of polysaccharides expressed on the mould cell walls can form reversible covalent bonds with the BA groups attached on the CuONPs surface. This allowed them to bind strongly to the mould surface, resulting in a very substantial boost of their antimould activity, which is not based on electrostatic adhesion, as in the case of bare CuONPs. The impact of these BA-surface functionalized nanoparticles was studied by measuring the growth of the mould colonies versus time. The BA-functionalized CuONPs showed significant antimould action, compared to the untreated mould sample at the same conditions and period of time. These results can be applied for the development of more efficient antimould treatments at a lower concentration of active agent with potentially substantial economic and environmental benefitsItem Open Access ENSEMBLE VOTING-BASED MULTICHANNEL EEG CLASSIFICATION IN A SUBJECT-INDEPENDENT P300 SPELLER(MDPI, 2021-11-26) Mussabayeva, Ayana; Jamwal, Prashant Kumar; Akhtar, Muhammad TahirClassification of brain signal features is a crucial process for any brain–computer interface (BCI) device, including speller systems. The positive P300 component of visual event-related potentials (ERPs) used in BCI spellers has individual variations of amplitude and latency that further changse with brain abnormalities such as amyotrophic lateral sclerosis (ALS). This leads to the necessity for the users to train the speller themselves, which is a very time-consuming procedure. To achieve subject-independence in a P300 speller, ensemble classifiers are proposed based on classical machine learning models, such as the support vector machine (SVM), linear discriminant analysis (LDA), k-nearest neighbors (kNN), and the convolutional neural network (CNN). The proposed voters were trained on healthy subjects’ data using a generic training approach. Different combinations of electroencephalography (EEG) channels were used for the experiments presented, resulting in single-channel, four-channel, and eight-channel classification. ALS patients’ data represented robust results, achieving more than 90% accuracy when using an ensemble of LDA, kNN, and SVM on four active EEG channels data in the occipital area of the brain. The results provided by the proposed ensemble voting models were on average about 5% more accurate than the results provided by the standalone classifiers. The proposed ensemble models could also outperform boosting algorithms in terms of computational complexity or accuracy. The proposed methodology shows the ability to be subject-independent, which means that the system trained on healthy subjects can be efficiently used for ALS patients. Applying this methodology for online speller systems removes the necessity to retrain the P300 speller.Item Open Access Epidemiological Outbreaks of Measles Virus in Kazakhstan during 2015(Japanese Journal of Infectious Diseases, 2018) Abeev, Arman; Zhylkibayev, Assylbek; Kamalova, Dinara; Kusheva, Nadezhda; Nusupbaeva, Gauhar; Tleumbetova, Nazim; Smagul, Manar; Beissenova, Sarkit; Aubakirova, Saltanat; Kassenova, Zhuldiz; Demessinova, Balzira; Amanbayev, Altay; Ramankulov, Yerlan; Shevtsov, AlexanderThis study involved epidemiological surveillance of the measles virus (MV) in the territory of the Republic of Kazakhstan during 2015–2016. We detected MV genotype D8 in this season of measles outbreak. A total of 2,341 cases were registered and 19 were identified by genotyping. Sixteen of these samples were attributed to subgroup A of genotype D8, while 3 imported cases were represented by genotypes B3 and H1.Item Open Access Extraction of high-purity silica from rice husk via hydrochloric acid leaching treatment(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2019) Azat, Seitkhan; Sartova, Zhanar; Bekseitova, Kalampyr; Askaruly, KydyrThe present paper aimed at the investigation of the effect of preliminary acid treatment on the structure and purity of extracted silica. In this study, the acid leaching of rice husk (RH) in 2 M hydrochloric acid solution before the calcination process at 600 ◦ C was proposed to achieve completely white silica with high specific surface area and low content of impurities. RH, selected from the Almaty Region, Kyzylorda Region, and Turkestan Region was used as the main silica source. The results confirmed that the highest purity (98.2%–99.7%) amorphous silica with a specific surface area between 120 and 980 m2 g −1 could be extracted during acid treatment and controlled calcination. The structure is amorphous, porosity diameter decreased from 26.4 nm to 0.9 nm, and specific pore volume increased from 0.5 to 1.2 cm3 g −1 .Item Open Access Fine structure and dynamics of EB3 binding zones on microtubules in fibroblast cells(Nazarbayev University School of Sciences and Humanities, 2019-08-01) Vorobyev, Ivan; Mustyatsa, V. V.; Kostarev, A. V; Tvorogova, A. V.; Ataullakhanov, F. I.; Gudimchuk, N. B.; Vorobjev, I. A.; ; ; ;End-binding (EB) proteins associate with the growing tips of microtubules (MTs)and modulate their dynamics directly and indirectly, by recruiting essential factors to fine-tune MTs for their many essential roles in cells. Previously EB proteins have been shown to recognize a stabilizing GTP/GDP-Pi cap at the tip of growing MTs, but information about additional EB-binding zones on MTs has been limited. In this work, we studied fluorescence intensity profiles of one of the three mammalian EB-proteins, EB3, fused with red fluorescent protein (RFP). The distribution of EB3 on MTs in mouse fibroblasts frequently deviated from single exponential decay and exhibited secondary peaks. Those secondary peaks, which we refer to as EB3-islands, were detected on 56% comets of growing MTs and were encountered once per 44 s of EB3-RFP comet growth time with about 5 s half-lifetime. The majority of EB3-islands in the vicinity of MT tips was stationary and originated from EB3 comets moving with the growing MT tips. Computational modeling of the decoration of dynamic MT tips by EB3 suggested that the EB3-islands could not be explained simply by a stochastic first-order GTP hydrolysis/phosphate release. We speculate that additional protein factors contribute to EB3 residence time on MTs in cells, likely affecting MT dynamics.