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The Relationship of Methylated Arginines with Urine Cadmium Levels
No full textBackground: In this study, we aimed to show that methylated arginines are the predictors of non-clinical atherosclerotic cardiovascular complications in metal workers exposed to Cd. Methods: The 80 Cd-exposed metal workers and 80 non-exposed workers (control) included in the study were available for measuring arginine, ADMA, SDMA, and L-NMMA levels. Results: The average urine Cd levels (CdU) found were 1.03 +/- 0.8 mu g/g creatinine (0.84 +/- 0.65 mu g/L) ranging from 0.01 to 3.00 mu g/g creatinine in the control group and 5.41 +/- 5.2 mu g/g creatinine (4.29 +/- 3.81 mu g/L) ranged from 0.11 to 27.2 mu g/g creatinine in metal workers. On the other hand, the median ratios of the different groups (exposed and control) were found to be 449.35 and 483.88 for arginine/ADMA and 1.28 and 1.33 SDMA/ADMA, respectively. Conclusions: The present study was undertaken to investigate the relationship between cadmium exposure and methylated arginines such as ADMA/SDMA/L-NMMA parameters which is important for the early detection atherosclerotic cardiovascular diseases . (Clin. Lab. 2022;68:xx-xx. DOI: 10.7754/Clin.Lab.2021.210504)Yozgat Bozok Univer-sity Scientific Research Foundation [6602b-TF/18-228]Acknowledgment: This study was supported by the Yozgat Bozok Univer-sity Scientific Research Foundation (grant No. 6602b-TF/18-228)
Synthesis, characterization and cytotoxic activity studies on cancer cell lines of new paraben-decorated monospiro-cyclotriphosphazenes
No full textCancer is one of the Leading causes of death worldwide. Among the causes of cancer-related deaths in women, breast cancer, which is the most common type of cancer in women, is in second place. On the other hand, colon cancer has the highest mortality rate and the fourth highest incidence in the world. For this reason, it is invaluable to find anti-cancer agents for cancer treatment, with research rapidly ongoing. Studies of phosphazene compounds in this field have an important pLace. For this purpose, monospiro-cycLotriphosphazene compounds decorated with different parabens that likely show biological activity were designed and successfully synthesized for the first time. The structures of the purified compounds (1-6) were elucidated using different spectroscopic techniques, such as matrix-assisted Laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, Fourier-transform infrared (FT-IR) spectroscopy, and H-1, C-13 and P-31 nuclear magnetic resonance (NMR) spectroscopies. In addition, the solid-state structure and geometry of compound 2 was determined via single-crystal X-ray structural anaLysis. Then, different concentrations of aLL of the compounds were investigated to determine their in vitro cytotoxicity activities against human breast adenocarcinoma (MCF-7) and Dukes' Type C colorectal adenocarcinoma (DLD-1) ceLL Lines by MTT assay. The obtained data were evaluated using Anova anaLysis methods and are presented as IC50 values. ALL compounds studied in the 12.5-200 mu M concentration range on MCF-7 and DLD-1 ceLL Lines showed cytotoxic effects. The results show that in particular compounds 2 (methyl paraben decorated monospiro-2,2'-biphenoxy cycLotriphosphazene) and 6 (benzyL paraben decorated monospiro-2,2'-biphenoxy cycLotriphosphazene) were generally found to be the most active compounds compared to others in terms of the viability of cells.GTU [2017-A105-35]The authors would like to thank the GTU (project number 2017-A105-35) for financial support. The authors thank the Amasya University Central Research Laboratory (AUMAULAB) for their kind use of their facilities. The authors would like to thank Yunus Zorlu for collecting single-crystal data and Derya Davarc and Ceylan Mutlu for their support in the single-crystal structure analysis
Prediction of geoid undulation using approaches based on GMDH, M5 model tree, MARS, GPR, and IDP
No full textThis study provides a comprehensive comparison of four different machine learning models including the group method of data handling (GMDH), M5 model tree (M5MT), multivariate adaptive regression spline (MARS), and Gaussian process regression (GPR) for predicting geoid undulation. For the first time, GMDH and M5MT were applied for this purpose. The obtained results were also compared with the classic inverse distance to a power (IDP) interpolation method. In order to assess the consistency of our results, two test sites with different topographic features were used for the evaluation of the models. In constructing the models, the geographic coordinate values and the geoid undulation value were used as inputs and output, respectively. Several statistical indices and rank analysis were used for evaluation of the models. According to the comparative results of all models in both test sites, the GMDH yielded the best performance among the developed models. The M5MT also exhibited acceptable results. Thus, it may be concluded that the proposed GMDH and M5MT have the potential to be alternative models that could assist geoscientists working with the geoid
The relationship between perceived stress, uncertainty emotions and hopelessness regarding pandemics in pregnant women
No full textThe objective of this study was to determine the emotional reactions of pregnant women towards the pandemic and to increase awareness of healthcare professionals on this subject. In this descriptive, cross-sectional, and correlational study, an online questionnaire was applied to 375 pregnant women (n = 375). Data were collected with pregnant information form, Intolerance of Uncertainty Scale and Beck Hopelessness Scale. The mean age of the pregnant women was 29.495 +/- 4.301, and the mean gestational week was 27.469 +/- 7.971. Pregnant women's levels of perceived stress and intolerance to uncertainty were high. There was a moderate positive correlation between stress and uncertainty levels of the women who stated that they experienced mild hopelessness. It is recommended to identify risky groups and provide the necessary psychological support by health professionals during the pandemic
Covalently bonded nanosilver-hydroxyethyl cellulose/polyacrylic acid/sorbitol hybrid matrix: thermal, morphological and antibacterial properties
No full textIn this study, an antibacterial, biodegradable, biocompatible, and environmentally friendly coating was prepared with an easy technique. Accordingly, Ag nanoparticles were synthesized to provide antibacterial properties to the coating, and its surface was modified with (3-Glycidyloxypropyl)trimethoxysilane (GPTMS) in order not to clump in the coating, to ensure homogeneous distribution on the surface, and to covalently bond to the coating. While preparing the coating formulation, polyacrylic acid (PAA), which are natural polymers, and hydroxyethyl cellulose (HEC), a derivative of cellulose, were preferred to reduce the consumption of petroleum derivatives. Then, sorbitol was used as a plasticizer. Synthesized Ag nanoparticles were included in the coating formulation containing PAA/HEC and sorbitol and thermally crosslinked at a high temperature. The size of Ag nanoparticles was analyzed by DLS while chemical composition after modification was analyzed by FTIR. Then, the chemical structure, thermal properties, surface properties, and antibacterial properties of the environmentally-friendly film were examined. It was observed that Ag nanoparticles, the surface of which were modified with GPTMS containing silicon groups, increased the thermal stability of the film, and the presence of Si and Ag on the surface was detected in SEM-EDAX measurements, and this showed that the aimed coating was obtained. It was observed that silver nanoparticles, of which their surface was modified, incorporated into the coating obtained from PAA and HEC, which are known to have no antibacterial properties, showed antibacterial activity against E. coli and S. aureus. The zone of inhibition was measured as 11 mm for both E. coli and S. aureus. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature
Bilgi Yönetiminde Büyük Verinin Evrimi: Bibliyometrik Bir Analiz
No full textRecently, the close relationship between big data and knowledge management has become one of the important agendas of businesses. The aim of this study is to systematize the literature on big data and knowledge management from a bibliometric perspective and to create a general framework for the past, present and future of the field. The present study examined 622 papers acquired from the Clarivate Analytics Web of Science (WoS) Core Collection database between 2013 and 2020. The results showed that the annual growth rate of the relevant field was found to be 42.9% indicating a higher popularity among researchers. China and USA are home to the most productive authors and institutions in the field. Also, country collaboration network, institutional co-authorship network, co-word network and co-citation network are given to present the intellectual structure of the field. This study is useful to understand leading trends in the field in terms of the most influential authors, institutions and countries, the most productive journals, the most frequent keywords, the collaboration networks and the co-citation networks. To the best of researchers’ knowledge, this study is the first bibliometric examination attempt to understand the flow at the intersection of big data and knowledge management over time. © 2022 University and Research Librarians Association (UNAK). All rights reserved
Four-Winged Propeller-Shaped Indole-Modified and Indole- Substituted Tetraphenylethylenes: Greenish-Blue Emitters with Aggregation-Induced Emission Features for Conventional Organic Light-Emitting Diodes
No full textAggregation-induced emission (AIE) is an extra-ordinary photochemical phenomenon described by Tang's group in 2001, where the aggregation of some organic molecules enhances their light emission by limiting intramolecular activity in the aggregate state. This phenomenon offers new opportunities for researchers due to its potential applications in optoelectronics, energy, and biophysics. Tetraphenylethylenes (TPEs) are reliable AIE luminogens with a wide range of successful applications in material chemistry. To expand the library of AIE-active TPEs, both a series of TPE analogues, in which the phenyl rotor has been replaced by the indole ring, and indole-substituted TPE derivatives were designed and synthesized through vinyl-aryl and aryl-aryl bond formations using the Suzuki coupling reaction. Efficient synthetic routes that delivered indole-modified and indole-substituted TPEs have been developed, and almost all heterocyclic TPE analogues have demonstrated AIE behavior. Furthermore, to test whether the indole ring can be diversified, two title compounds were converted to a series of bis(indolyl)methane (BIM), and these BIM-TPE materials showed typical AIE properties. Interestingly, two compounds indicated a solvent vapor fuming reversible switch between bright blue emission and greenish-yellow emission. Upon fuming with dichloromethane, their fluorescence spectra showed 8 and 32 nm red-shift and could return to the original state after fuming with hexane. Furthermore, we have explored the effects of replacing the phenyl ring in TPE with indole together with the substitution of TPE with indole ring(s) on the performance of organic light-emitting diode (OLED) device applications. In addition, density functional theory calculations; the optical, electrochemical, light emission, electroluminescence characteristics; and admittance spectroscopic analysis of OLED devices of four representative TPEs have been investigated in detail. As a result, the indole-TPEs are potential blue emitters with AIE features for conventional OLEDs, which is a significant color in displays and lighting.Scientific and Technological Research Council of Turkey (TUBITAK); [116Z175]? ACKNOWLEDGMENTS We would like to thank the Scientific and Technological Research Council of Turkey (TUBITAK) for their support of this research (project no: 116Z175)
On addressing the similarities between STDP concept and synaptic/memristive coupled neurons by realizing of the memristive synapse based HR neurons
No full textThe Spike-Time-Dependent-Plasticity (STDP) learning rule is frequently associated with the memristor structures in the neuromorphic studies, recently. In this study, after two HR neurons are coupled with a memristor based synapse structure as a unidirectional coupling; it is aimed to correlate the STDP learning rule and the memristor based synapse structure. In line of this motivation, two HR neurons (the transmitter and the receiver neurons) have been coupled with a memductance structure. After the current at the output of this memristor based synapse has been applied to the receiver neuron, a phase shift has been induced on the membrane potential of this receiver neuron. Additionally, this phase shift can be controlled by changing the 'Ron' resistance that is a parameter of the windowing function definition of the memristor device similar to the synaptic coupling weight parameter. Since the firing times of these coupled HR neurons can be controlled by changing this 'Ron' resistance, the STDP learning rule, which is based on the instantaneous firing time difference between the coupled neurons, has been validated as an alternative view point in here. The similarity between the pattern of the STDP learning rule and the pattern of two HR neurons coupled with the chemical and the memristor based synapses has been confirmed by comparing the numerical simulation results and it has been seen that the memristor device can be used as an alternative synapse definition in the neuromorphic studies. Finally, two HR neurons coupled with the memristor based synapse have been successfully realized by using the FPGA equipment, so an alternative neuromorphic study, which is associated with the STDP learning rule, memristor synapse and HR neurons, has been presented to the literature with this implementation. (c) 2021 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CCErciyes University Scientific Research Projects Coordination Unit (ERU/BAP); TUBiTAK 2210-C program; [FYL-2021- 10816]; [1649B022001684]We would like to thank Erciyes University Scientific Research Projects Coordination Unit (ERU/BAP) and TUBiTAK. This work is supported by the Erciyes University Scientific Research Projects Coordination Unit (ERU/BAP) under project codes FYL-2021- 10816 and TUBiTAK 2210-C program under project codes 1649B022001684
Low-velocity impact response of halloysite nanotube reinforced glass/epoxy multi-scale composite. Part 1: Dynamic loading performance
No full textOne of the biggest obstacles to fiber-reinforced composite laminates is out-of-plane dynamic loading. Specifically, low-velocity impact loading in an out-of-plane direction leads to matrix cracking, delamination, and fiber breakage damages due to weak fiber-matrix interactions. This paper aims to examine the dynamic loading behavior of nano reinforced glass/epoxy composite laminates under various impact energies. Moreover, to enhance fiber-matrix interaction, halloysite nanotubes (HNTs) with lower cost among the nanotube morphologies such as carbon and TiO2 were introduced to the epoxy matrix. The impact performance and the damage propagation were also investigated. As a result, the HNT-reinforced multiscale composite sample had 28% more impact load carrying capacity and absorbed 18% less energy than its unmodified counterpart. Image processing was utilized to determine the damage evaluation by analyzing both front and back surfaces. The improvement of the fiber-matrix interface with HNTs reinforcement resulted 59% and 46% less damage to the front and back damage surfaces, respectively. The acquired results were supported by macro-size examination and micro-size analyzing via scanning electron microscopy (SEM). These results pave the way towards designing fiber reinforced composites to be utilized for the transportation of dangerous liquids such as acids or solvents.Scientific Research Projects Coordinatorship of Amasya University [FMB-BAP 20-0441]The Scientific Research Projects Coordinatorship of Amasya University, Grant/Award Number: FMB-BAP 20-044
ON THE HYERS-ULAM STABILITY OF DELAY DIFFERENTIAL EQUATIONS
No full textIn this paper, we consider the stability problem of delay differential equations in the sense of Hyers-Ulam and Hyers-Ulam-Rassias. By using a well known fixed point alternative on generalized complete metric spaces, we obtain some new stability criteria. Our results extend and improve the results described in literature since their proofs are based on fewer and weaker assumptions than the recent results dealing with this problem. Some illustrative examples are also given to compare these results and visualize the improvement. © 2022, A. Razmadze Mathematical Institute of Iv. Javakhishvili Tbilisi State University. All rights reserved