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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.
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, Alexander
This 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.
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, Salimgerey
The 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.
Open Access
Doped Carbon Dots for Sensing and Bioimaging Applications: A Minireview
(Nazarbayev University School of Sciences and Humanities, 2018-05-18) Atabaev, Timur
In 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.
Open Access
Gold-catalyzed post-Ugi alkyne hydroarylation for the synthesis of 2-quinolones
(Beilstein J. Org. Chem., 2018-10-04) Du, Xiaochen; Huang, Jianjun; Nechaev, Anton A.; Yao, Ruwei; Gong, Jing; Van der Eycken, Erik V.; Pereshivko, Olga P.; Peshkov, Vsevolod A.
A series of propargylamides containing an electron-rich benzene ring was prepared through the Ugi reaction of 3,5-dimethoxyaniline with various propiolic acids, aldehydes and isocyanides. Subjecting these adducts to a gold-catalyzed intramolecular alkyne hydroarylation process allowed to efficiently construct the 2-quinolone core bearing a branched substituent on the nitrogen atom...
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, Kydyr
The 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 .
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, Mannix
The 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.
Open Access
Quick synthesis of fluorescent nitrogen-doped carbon nanoparticles for selective and sensitive Fe(III) detection in water
(Nazarbayev University School of Sciences and Humanities, 2019-03-06) Molkenova, Anara; Amangeldinova, Yerkezhan; Aben, Dauren; Sayatova, Saya; Atabaev, Timur
Recently, fluorescent carbon nanostructures have attracted enormous attention thanks to their excellent optical properties, low-cost, chemical inertness and stability. In this study, we demonstrated a quick, facile, environment-friendly and low-cost synthesis method for the preparation of fluorescent nitrogen-doped carbon nanoparticles (N-CNPs). Prepared N-CNPs have excitation-dependent fluorescent properties and demonstrate high selectivity towards Fe(III) ions in water. We found that prepared N-CNPs can be used for sensitive detection of Fe(III) ions in the range of 1–30 ppm. Thus, fluorescent N-CNPs can be a promising material for fast and low-cost analysis of Fe(III) ions in water.
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, Davit
The 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 transformations
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.
Open Access
Sn-Doped Hematite Nanoparticles for Potential Photocatalytic Dye Degradation
(IOP Publishing, 2020-01-01) Em, Svetlana; Yedigenov, Mussa; Molkenova, Anara; Khamkhash, Laura; Atabaev, Timur
Recently, low-cost hematite (α-Fe2O3) metal oxide semiconductor has attracted enormous attention for the photoelectrochemical water splitting and photocatalytic applications. The main purpose of this work is to study the effects of Sn-doping on the photocatalytic properties of hematite nanoparticles (NPs). Morphology and physicochemical properties of prepared samples were analyzed using X-ray diffraction analysis (XRD), transmission electron microscope (TEM), and UV-vis spectroscopy. Rhodamine B (RB) dye was used as a model organic pollutant to test the photocatalytic activity of prepared samples. It was found that the photocatalytic activity of Sn-doped hematite NPs was higher than that of the undoped hematite NPs. The recyclability tests suggested that 3 mol% Sn-doped hematite NPs can be used as a promising reusable photocatalyst for dyes degradation.
Open Access
Stable Colloidal Silica Particles Doped with a Fluorescent Dye
(IOP Publishing, 2020-01-01) Mulikova, Tomiris; Khamkhash, Laura; Dukenbayev, Kanat; Molkenova, Anara; Atabaev, Timur
In this study, we described the quick synthesis strategy of stable colloidal silica particles encapsulated with a fluorescent dye. Atomic Force Microscopy AFM, Fourier-Transform Infrared Spectroscopy FTIR, and Fluorescence Spectroscopy FS were utilized to characterize the obtained silica particles. AFM analysis revealed that obtained silica particles have a spherical shape with a mean size of 210 ± 13 nm. FS analysis showed that fluorescent dye was successfully incorporated into a silica matrix. In particular, eye-visible green fluorescence emission with a peak maximum at 526 nm was detected. The emission stability of prepared particles was tested in a biologically-relevant pH range, under constant UV irradiation and at different storage time intervals.
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, Rostislav
Very 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.
Open Access
Three-component reaction of azulene, aryl glyoxal and 1,3-dicarbonyl compound for the synthesis of various azulene derivatives
(Royal Society of Chemistry, 2020-03-10) Peshkov, Vsevolod A.; Peshkov, Anatoly A.; Amandykova, Sagadat; Gimnkhan, Aidana; Pereshivko, Olga P.; Gong, Jing; Yu, Jiafeng; Huang, Jianjun; Kashtanov, Stepan
A three-component reaction of an azulene, an aryl glyoxal and a 1,3-dicarbonyl compound has been elaborated to access a series of azulene derivatives. Some of these azulene-containing adducts were further subjected to post-MCR transformations to assemble azulene–heterocycle conjugates.
Open Access
SOLUTION-BASED DEPOSITION OF TRANSPARENT EU-DOPED TITANIUM OXIDE THIN FILMS FOR POTENTIAL SECURITY LABELING AND UV SCREENING
(MDPI, 2020-06-08) Molkenova, Anara; Khamkhash, Laura; Zhussupbekova, Ainur; Zhussupbekov, Kuanysh; Sarsenov, Sagyntay; Taniguchi, Izumi; Shvets, Igor V.; Atabaev, Timur Sh.
Transparent titanium oxide thin films attract enormous attention from the scientific community because of their prominent properties, such as low-cost, chemical stability, and optical transparency in the visible region. In this study, we developed an easy and scalable solution-based process for the deposition of transparent TiOx thin films on glass substrates. We showed that the proposed method is also suitable for the fabrication of metal-doped TiOx thin films. As proof-of-the-concept, europium Eu(III) ions were introduced into TiOx film. A photoluminescence (PL) study revealed that Eu-doped TiOx thin films showed strong red luminescence associated with 5D0→7Fj relaxation transitions in Eu (III). We found that prepared TiOx thin films significantly reduce the transmittance of destructive UV radiation; a feature that can be useful for the protection of photovoltaic devices. In addition, transparent and luminescent TiOx thin films can be utilized for potential security labeling.
Open Access
SURFACE INTERACTIONS AND MECHANISMS STUDY ON THE REMOVAL OF IODIDE FROM WATER BY USE OF NATURAL ZEOLITE-BASED SILVER NANOCOMPOSITES
(MDPI AG, 2020-06-12) Inglezakis, Vassilis J.; Satayeva, Aliya R.; Yagofarova, Almira; Tauanov, Zhandos; Meiramkulova, Kulyash; Farrando-Pérez, Judit; Bear, Joseph C.
In this work a natural zeolite was modified with silver following two different methods to derive Ag2O and Ag0 nanocomposites. The materials were fully characterized and the results showed that both materials were decorated with nanoparticles of size of 5–25 nm. The natural and modified zeolites were used for the removal of iodide from aqueous solutions of initial concentration of 30–1400 ppm. Natural zeolite showed no affinity for iodide while silver forms were very efficient reaching a capacity of up to 132 mg/g. Post-adsorption characterizations showed that AgI was formed on the surface of the modified zeolites and the amount of iodide removed was higher than expected based on the silver content. A combination of experimental data and characterizations indicate that the excess iodide is most probably related to negatively charged AgI colloids and Ag-I complexes forming in the solution as well as on the surface of the modified zeolites.
Open Access
SANDWICH SERS IMMUNOASSAY OF HUMAN IMMUNOGLOBULIN ON SILICON WAFER COMPARED TO TRADITIONAL SERS SUBSTRATE, GOLD FILM
(Sensing and Bio-Sensing Research, 2020-08) Kunushpayeva, Zhanar; Rapikov, Alisher; Akhmetova, Aktilek; Sultangaziyev, Alisher; Dossym, Dina; Bukasov, Rostislav
Likely the first application of silicon wafer as a substrate for sandwich immunoassay with Surface Enhanced Raman Scattering (SERS) detection is reported hereafter. Human immunoglobulin (hIgG) was used as a model biomarker in the simultaneous comparative assay on gold film and on Si wafer, an alternative (less expensive and potentially more resistant to surface contamination and non-specific binding) substrate. The Limits of Detection calculated from the data obtained with two-laser wavelength (633 nm and 785 nm) were about 1 × 10−12 mol of antigen or less for both substrates, which is close to the minimal detectable concentration of 30 pM. An approximately logarithmic response was observed across at least a factor of 133 in the dynamic range 0.03–4 nM. However, if four parametric logistic curve is used for the calibration, LOD on silicon would become significantly lower than LOD on gold (3 pM vs 28 pM). A much smaller slope of calibration plot was compensated by a significantly smaller standard deviation in the signal of the blank for the assay on silicon, as compared to the assay on gold. This report may encourage researchers to try silicon or other non-noble metal materials as SERS substrates for the detection of biomarkers.
Open Access
EDITORIAL: FLUORESCENT CARBON-BASED NANOSTRUCTURES FOR BIOIMAGING APPLICATIONS
(Frontiers in Chemistry, 2020-09) Atabaev, Timur Sh.; Han, Dong-Wook
Recently 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.
Open Access
REVIEW: DETECTION AND QUANTIFICATION OF PROTEINS IN HUMAN URINE
(Talanta, 2020-10-14) Aitekenov, Sultan; Gaipov, Abduzhappar; Bukasov, Rostislav
Extensive medical research showed that patients, with high protein concentration in urine, have various kinds of kidney diseases, referred to as proteinuria. Urinary protein biomarkers are useful for diagnosis of many health conditions – kidney and cardio vascular diseases, cancers, diabetes, infections. This review focuses on the instrumental quantification (electrophoresis, chromatography, immunoassays, mass spectrometry, fluorescence spectroscopy, the infrared spectroscopy, and Raman spectroscopy) of proteins (the most of all albumin) in human urine matrix. Different techniques provide unique information on what constituents of the urine are. Due to complex nature of urine, a separation step by electrophoresis or chromatography are often used for proteomics study of urine. Mass spectrometry is a powerful tool for the discovery and the analysis of biomarkers in urine, however, costs of the analysis are high, especially for quantitative analysis. Immunoassays, which often come with fluorescence detection, are major qualitative and quantitative tools in clinical analysis. While Infrared and Raman spectroscopies do not give extensive information about urine, they could become important tools for the routine clinical diagnostics of kidney problems, due to rapidness and low-cost. Thus, it is important to review all the applicable techniques and methods related to urine analysis. In this review, a brief overview of each tech nique’s principle is introduced. Where applicable, research papers about protein determination in urine are summarized with the main figures of merits, such as the limit of detection, the detectable range, recovery and accuracy, when available.
Open Access
REVIEW: APPLICATIONS OF SURFACE-ENHANCED FLUORESCENCE (SEF) SPECTROSCOPY IN BIO-DETECTION AND BIOSENSING
(Elsevier, 2020-12) Sultangaziyev, Alisher; Bukasov, Rostislav
Surface-enhanced fluorescence (SEF) is rapidly becoming one of the main spectroscopic techniques for the detection of a variety of biomolecules and biomarkers. The main reasons for this trend are the high sensitivity and selectivity, robustness, and speed of this analytical method. Each year, the number of applications that utilize this phenomenon increases and with each such work, the complexity and novelty of the used substrates, pro-cedures, and analytes rises. To obtain a clearer view of this phenomenon and research area, we decided to combine 76 valuable research articles from a variety of different research groups into this mini-review. We present and describe these works concisely and clearly, with a particular interest in the quantitative parameters of the experiment. These sources are classified according to the nature of the analyte, on the contrary to most reviews, which sort them by substrate nature. This point of view gives us insight into the development of this research area and the consequent increase in the complexity of the analyte nature. Moreover, this type of sorting can show possible future routes for the expansion of this research area. Along with the analytes, we can also pay attention to the substrates used for each situation and how the development of substrates affects the direction of research and subsequently, the choice of an analyte. About 108 sources and several interesting trends in the SEF research area over the past 25 years are discussed in this mini-review.