Yuzuncu Yil University
Recent publications
The aims of this study were to compare the incidence of occupational accidents during one-year periods of the COVID-19 Pandemic and before the COVID-19 Pandemic, and to determine in which sectors occupational accidents occurred and what types of injuries were sustained in the population of Tokat, Turkey. A retrospective review was made of the records of Tokat State Hospital of patients injured in occupational accidents between 12.03.2019 and 11.03.2021. The patients injured in occupational accidents were classified according to age, gender, sector, accident type, trauma localization and type, time of the accident, and outcome of the injuries. Of 608 patients injured in occupational accidents, 384 (63.2%) were injured in the period before the pandemic and 224 (36.8%) were injured in the period during the pandemic (p < 0.001). Most work-related injuries occurred in the industry sector (n = 287; 47.2%; p < 0.001). Occupational accidents increased in the service sector (p < 0.001), but decreased in other sectors. The increase in occupational accidents in the health sector (p < 0.001) and transportation sector (p < 0.05) within the service sector caused a general increase despite the decrease in other service sectors (p > 0.05). In current study, the increase in the number of injuries in the transportation sector due to the increase of motor courier accidents, in health sector, and in pandemic quarantines were remarkable. It was evaluated that this narrow-scoped study pioneered comprehensive studies on the measures that can be taken to prevent occupational accidents in such pandemics in the future.
In this paper, the stability in terms of Bielecki–Ulam–Hyers and stability in terms of Bielecki–Ulam–Hyers–Rassias of non–linear impulsive Hammerstein integro–dynamic system with delay and non–linear impulsive mixed integro–dynamic system on time scales are achieved by utilizing fixed point approach along with Lipschitz condition and Gronwall’s inequality. Examples are also provided for the verification of the results.
In the present, thymol based new organic compounds (4A, 4B and 4C) are designed and synthesized via Steglich Esterification Reactions and Pd-catalyst Sonogashira Coupling Reactions. After isolation and characterization, thymol based hybrid molecules are used for hydrazine (N2H4) electrooxidation reactions as anode catalysts. A variety of metal based anode catalyst have been reported in literature, but this study may be the first study for thymole based hybrid molecules as an anode catalyst in fuel cells. The performance of hybrid molecules was investigated via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in hydrazine solution. Hybrid 2-isopropyl-5-methylphenyl-4-oxo-4-(5-(p-tolylethynyl)thiophen-2-yl)butanoate (4C) gives the highest performance as 3.66 mAcm⁻² (17.24 mAmg⁻¹). Our results displayed that natural products like thymol derivatives may be new generation anode catalyst for fuel cells, and they may be alternative for expensive Pd and Pt based metal anode catalyst.
The 0.1 % CdTe/TiO2 photocatalysts with different atomic molar ratios (90–10, 70–30, 50–50, and 30–70) were synthesized by the wetness impregnation method and characterized by the XRD, SEM-EDX and mapping, N2 adsorption–desorption, ICP-MS, TEM-EDS and STEM mapping, UV–VIS spectroscopy, fluorescence spectroscopy, XPS, TPR, TPO, and TPD analyses. The photocatalytic activities were examined to investigate by CV, CA, and EIS electrochemical analyses for photocatalytic fuel cells (PFCs) in glucose solution in the dark and under UV illumination. The characterization analyses revealed that anatase TiO2 was formed for the catalyst and changed its electronic structure and surface properties when doped with metal. The photocatalytic glucose electrooxidation results indicated that the 0.1 % CdTe(50–50)/TiO2 catalyst exhibited much higher photocatalytic activity, stability, and resistance than other catalysts both in the dark (6.22 mA cm⁻²) and under UV illumination (16.88 mA cm⁻²). The study offered a promising new type of photocatalysts for PFC applications.
Among biological applications, plant-mediated Pd NPs for multi-drug resistance (MDR) developed in pathogenic bacteria were synthesized with the help of biomass of lemon peel, a biological material, with a non-toxic, environmentally friendly, human-nature green synthesis method. Characterization of synthesized Pd NPs was characterized by UV-Vis spectrometry, Transmissive Electron Microscopy (TEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) techniques. According to TEM analysis, Pd NPs were confirmed to be in a spherical shape and the mean particle size was determined to be 4.11 nm. The crystal structure of Pd NPs was checked using XRD analysis and the mean particle size was observed to be 6.72 nm. Besides, the antibacterial activity of Pd NPs was determined by Escherichia coli (E. coli) (ATCC 8739), Bacillus subtilis (B. subtilis ATCC 6633), Staphylococcus aureus (S. aureus ATCC 6538), Klebsiella pneumoniae (K. pneumoniae ATCC 11296) and Serratia marcescens (S. marcescens ATCC) bacteria. Antibacterial activity was determined to be high in Pd NPs which is in conformance with the results acquired. The Pd NPs showed good photocatalytic activity, after 90 min illumination, about 81.55% and 68.45% of MB and MO respectively were catalysed by the Pd NPs catalyst, and 74.50% of RhB dyes were removed at 120 min of illumination. Within the scope of this project, it is recommended to use Pd NPs obtained by the green synthesis in the future as an antibacterial agent in biomedical use and for the cleaning of polluted waters.
In this work, pure and MIL-101 doped TiO2 films on fluorine doped tinoxide (FTO) were prepared by sol-gel method for dye sensitized solar cell (DSSC) fabrication. MIL-101 metal-organic framework (MOF) structure was synthesized by hydrothermal method and it was used as dopant in TiO2 to enhance an efficiency of DSSC device for the first time. The surface morphology of pure and MIL-101 doped TiO2 films were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), the crystallite size and structural properties of these films were studied by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) techniques, respectively. Ultraviolet–visible spectroscopy (UV–Vis) measurement presents the change in an optical characteristic and the band gap of the film with MIL-101 incorporation owing to its high surface area. The efficiency enhancement in DSSC device with MIL-101 doping was analyzed via current-voltage (I–V) measurement under various power of solar simulator. The results confirm that power conversion efficiency (PCE) can enhance with MIL-101 doping into TiO2. The power conversion efficiency of [email protected] is 8.687% under 100 mW/cm² illumination power, which is 1.85 times greater than PCE of undoped DSSC (4.689%). The enhancing efficiency of [email protected] can be associated with the energy band alignment, improvement in photoelectron trapping, and increase in dye adsorption owing to pore structure of MIL-101.
An efficient methods for the synthesis of 2-(2,5-dimethylphenyl)-3-iodobenzo[b]thiophene (4) is described, and investigated its anode catalyst performance by using electrochemical methods (CV, CA and EIS). When 2-(2,5-dimethylphenyl)-3-iodobenzo[b]thiophene (4) is applied, the specific activity is found as 25.811 mA/cm². Interestingly, when Palladium (Pd) is electrochemically deposited on the benzothiophene derivative, the catalytic activity increased the 80.930 mA/cm². This result is highest than the current metal based anode catalyst. Moreover, EIS and CA measurements display that Pd doped benzothiophene organic catalyst have high stability, and give the low charge transfer resistance. Energy dispersive X-ray (SEM-EDX), electron microscopy, TEM are used for the determination of its surface morphology. As a result, 2-(2,5-dimethylphenyl)-3-iodobenzo[b]thiophene (4) may be alternative electro-catalysts in fuel cell applications.
Understanding the relative contributions of different spawning habitats to adult fish populations is central to effective fisheries management and species conservation. The Tarek (Alburnus tarichi) is an adfluvial cyprinid that is endemic to the alkaline-saline waters of Lake Van, Turkey. Tarek are culturally and economically important to the region, and also threatened by anthropogenic impacts, including poaching, dams, water diversions, pollution, and habitat degradation. Here we analyzed otoliths from 120 adult fish caught in Lake Van in 2016–2017 to reconstruct the age structure and natal origins of this Tarek population. Ages ranged from 2 to 10 years, with most fish belonging to the 2011–2014 cohorts (age 3–5). We analyzed strontium isotope ratios from water samples collected in 2016 and 2018 to build a baseline map and then used linear discriminant function analysis to classify Tarek to their likely natal origins. We found that adult Tarek originated from at least 7 different major tributaries of Lake Van, with a majority of fish originating from the Gevas and Engil tributaries in the south. Furthermore, the relative contributions of fish from each tributary varied among years, suggesting that a mosaic of natal habitats may be important for population stability. These results suggest that protection of all Lake Van watersheds from anthropogenic disturbance could be valuable for maintaining the stability of the Lake Van Tarek population and fishery.
Background: Although many studies have been conducted using the foramen magnum for sex estimation, recent findings have indicated that the discriminant and regression models obtained from the foramen magnum may not be reliable. Artificial Neural Networks, was used as a classification technique in sex estimation studies on some other bones, did not used in sex estimation studies on the foramen magnum until now. The aim of this study was sex estimation on an Eastern Turkish population sample using foramen magnum measurements, discriminant analyses and Artificial Neural Networks. Methodology: The study was performed on the CT images of a total of 720 cases, comprising 360 males and 360 females. For sex estimation, discriminant analysis and Artificial Neural Networks were used. Results: The accuracy rate was 86.7% with discriminant analysis and when sex estimation accuracy was determined according to cases with posterior probabilities above 95%, the accuracy ranged from 0% to 33.3%. With the use of the discriminant formulas of 2 other studies, obtained from different Turkish samples, sex could be determined at a rate of 84.6%. Some formulas were found to be unsuccessful in sex estimation. Sex estimation accuracy of 88.2% was achieved with Artificial Neural Networks. Conclusion: In this study, it was found that sex could be determined to some extent with discriminant formulas from other samples from the same population, although some formulas were unsuccessful. With the use of image processing techniques and machine learning algorithms, better results can be obtained in sex estimation.
Taking into consideration of substantial role of energy system and sustainable development goals (SDGs) in modern society, it is critical to analyse current situation and forthcoming renewable energy development strategies under the impact of COVID-19. For this purpose, this paper provides significant new insights to assess effective approaches, opportunities, challenges and future potential capabilities for the development of energy systems and SDGs under on-going pandemic and in case of a future global crisis. The digital energy systems with Industry 4.0 (I4.0), which provide noteworthy solutions such as enhancing energy efficiency policy, providing clean, secure and efficient energy and achieving SDG targets, has been discussed and evaluated. Integration of the smart grid (SG) architecture with blockchain-Internet of Things (IoT)-based technologies is also offered. Alongside the various discussions, short-term, mid-term and long-term plans have been suggested in determining the well-defined renewable energy development and SDGs targets, struggling with climate change, transition to a more sustainable energy future and reaching global net-zero emissions. To achieve SDGs and provide more strong and sustainable energy systems under the continuing pandemic and in case of potential risk of forthcoming global crisis, this paper reveals significant perceptions that inform politicians and legislators in performing successful policy decisions.
Bioethanol production from algal biomass is a promising alternative for sustainable biofuel production. Algae possess a high photosynthetic capacity and an adaptive ability to thrive under harsh environmental conditions. The potential properties of Scenedesmus acuminatus CCALA 436 were assessed in this research for its bioethanol efficiency, and the effects of growing the algae in wastewater and at different concentrations of mepiquat chloride were studied. Also, pre-treatment efficiencies of different concentrations of calcium oxide were carried out on microalgae biomass. Superoxide dismutase, catalase activity, glutathione, and malondialdehyde contents of microalgae were examined, and the changes in chlorophyll, photoprotective carotenoid contents, and protein concentrations were determined. The results revealed that the maximum sugar and ethanol contents of Scenedesmus acuminatus CCALA 436 were 44.7 ± 1.5% and 20.32 g/L, respectively, for 50% wastewater and mepiquat chloride (2.5 mg/L) after pre-treatment with calcium oxide (0.08%). Additionally, the levels of oxidative enzymes varied depending on the wastewater concentrations. These findings indicate Scenedesmus acuminatus CCALA 436 grown in wastewater and mepiquat chloride can be used for the treatment of wastewater and the production of ethanol and high-value products such as carotenoid.
Aim: Nail involvement is common in psoriatic arthritis. This study assesses clinical characteristics, nail psoriasis prevalence, and impact of nail psoriasis on disease activity in patients with psoriatic arthritis (PsA). Method: This cross-sectional multicenter study was conducted by the Turkish League Against Rheumatism using PsA patients recruited from 25 centers. Demographic and clinical characteristics of PsA patients, such as disease activity measures, quality of life, and nail involvement findings were assessed during routine follow-up examinations. Patients were divided into two groups according to the presence or absence of nail psoriasis and compared using the χ2 test or Fisher exact test for categorical variables and the t-test or Mann-Whitney U test for continuous variables. Results: In 1122 individuals with PsA, 645 (57.5%) displayed nail psoriasis. The most frequent features of fingernails were ridges (38%), followed by pitting (21%) and onycholysis (19%). More females were present in both groups (with and without nail psoriasis; 64% vs 67%, P < 0.282). Patients with nail psoriasis were older, indicated more pain and fatigue, experienced greater swelling, tender joint counts, and skin disease severity, and had a higher disease activity score compared with those without nail psoriasis (all P < 0.05). Conclusion: We demonstrate an increased prevalence of nail psoriasis observed in patients with psoriatic arthritis. Patients with nail involvement experience increased disease activity, lower quality of life, and diminished mental and physical status compared with those without nail involvement.
Understanding the COVID-19 crisis that arose in 2019 is a significant important case study to prepare scenarios and meet electrical energy consumption and high renewable energy production (REP), especially in the context of the power systems. Although many researchers have investigated the medical field and electric power sectors associated with the COVID-19 pandemic, critical factors affecting the development of the REP like electric demand, power system, electric markets, economy, and environment have are still not studied in great detail. In this perspective, this paper analyses the impact of the COVID-19 outbreak on the development of the REP, electrical energy consumption, power system maintenance, electric markets, energy demand, ongoing investment projects/investment plans, economy and renewable energy sectors. Estimation of energy demand based on cooling degree days (CDDs) and heating degree days (HDDs) methods has been examined and contrasted with the same period in prior years to observe electricity consumption Besides, climate change and energy efficiency or energy intensity related to the energy demand have been investigated and analysed before and following the pandemic. Some important energy statistical data is addressed and examined in detail. In addition to these, various critical factors such as driver and barrier forces affecting the REP has been discussed during lockdown restrictions of the COVID-19. These findings will help researchers and academicians to analyse the far-reaching implications of the COVID-19 outbreak on the energy demand and contribute to figuring out and plan higher renewables share scenarios and power system management issues.
Effect of new design of elongated jet hole on the thermal efficiency (ηth) of a solar air heater (SAH) has been numerically studied in this paper. Jet impingement technique, being one of the important active techniques, has been implemented on the absorber plate of the SAH surface to increase the convective heat transfer performance. Several designs of elongated jet hole (EJH) technique (gradually increasing, gradually decreasing along the crossflow direction, and equally extended), which is highly effective application to get rid of cross-flow, has been inserted to the jet plate. The main interest of this paper is to investigate the effect of different EJH configurations on convective heat transfer performance and ηth of the SAH. 15 x 7 array of jets have been mounted on the confinement plate. Results have been compared with the conventional SAH, which has the jet impingement Case1. Numerical computations have been conducted using RNG k-e turbulence model. Average Nusselt number (Nu) on the absorber plate surface, ηth of the SAH, and performance evaluation criteria (PEC) have been quantitatively investigated comprehensively. As a result of calculations, the Nu and ηth of SAH can be enhanced by 31.80% and 2.46%, respectively, using Case4 instead of Case1 at Re=25000. Besides, the pressure drop of SAH dramatically rises by 10.26%, when Case4 and Case1 compared with each other at Re=25000. Despite increment in pressure drop, the PEC value achieves to 1.28. Finally, it is concluded that the equally extended EJH presents well performance compared to gradually increasing and decreasing EJH.
This study aimed to examine the testicular functions with sperm analysis of patients with COVID‐19. The study was carried out with male patients aged between 18 and 50 years with positive RT‐PCR test and SARS‐CoV‐2 virus between December 2020 and April 2021. A total of 103 participants were included in the study. The mean age was 31.24 ± 5.67 (19–45) years and the mean body mass index of the participants was 28.41 ± 4.68 kg/m2. The patients were divided into two groups, group‐1 was patients who had COVID‐19, group‐2 was healthy men. A semen analysis of both groups was performed, and the serum total testosterone, FSH, LH, anti‐mullerian hormone and Inhibin‐B tests were analysed and recorded. The testicular dimensions and testicular densities were examined by ultrasound and elastography for both groups. Comparing the patient and control groups results, this study found that the sperm count per 1 cc (p = 0.01) and total motility (p = 0.01) in group‐1 was lower than in the control group, the testicular dimensions decreased (for right testis group‐2 was 15.39 ± 4.78 ml versus group‐1 was 12.11 ± 4.62 cm3 p < 0.01, for left testis group‐2 was 16.01 ± 5.12 versus group‐1 was 11.92 ± 4.78 cm3; p < 0.01), and the shear wave velocities were significantly higher in group‐1 patients. In conclusion, sperm parameters deteriorate in men who have symptomatic disease with SARS‐CoV‐2 infection. The fact that the cause of this deterioration is characterized by changes at the cellular level in the testis raises doubts about the persistence of this condition.
Background: There is a growing interest in the use of natural compounds for the treatment of gastric ulcers. The multifunctional roles of betaine in various diseases make this natural substance a favorable pre-drug for ulcer treatment. This study aims to determine the competence of betaine in gastroprotection against ethanol-induced damage and to explore underlying mechanisms considering its effects on liver and kidney activity and blood parameters. Methods: Wistar albino rats were orally treated with vehicle (distilled water) or betaine (250 mg/kg) for twenty-one days and then ulcer formation was induced by ingestion of 75% ethanol. Gastric mucosal damage was evaluated by gross examination and histopathological analysis. Homocysteine levels, lipid peroxidation, total antioxidant status (TAS), total oxidant status (TAS), antioxidant enzymes and pro-inflammatory and anti-inflammatory cytokines levels were assessed by enzyme-linked immunosorbent assay (ELISA) or immunohistochemistry. Furthermore, routine biochemical tests were performed and hematological parameters were analyzed. Results: Betaine ameliorated any gastric mucosal damage and reduced homocysteine levels significantly. The TOS and malondialdehyde (MDA) levels were decreased while the TAS, glutathione (GSH) levels and catalase (CAT) activity were increased upon the betaine treatment. Betaine reduced apoptosis by regulating Bax and Bcl-2 levels, however, it did not alter inflammatory mediators. Additionally, betaine improved serum potassium (K⁺) and blood urea nitrogen (BUN) levels, whereas it increased alanine aminotransferase (ALT) levels and impaired hematological parameters. Conclusions: Altogether, these data illustrated that betaine exhibits a gastroprotective effect against ulcers through the homocysteine pathway by modulating oxidative stress in the gastric tissue; however, its systemic effects should not be ignored.
Background This in vitro study evaluated the effect of amine-free initiator system and polymerization type on long-term color change of amine-free light-cure and dual-cure resin cements. Methods Sixty disk-shaped specimens (10 × 1 mm) were prepared from six different amine-free resin cements; NX3 Nexus light-cure (LC) and dual-cure (DC), Variolink Veneer (LC) and Variolink II (DC), Relyx Veneer (LC) and Rely X Ultimate (DC). A feldspathic porcelain specimen (12 × 14 × 0.8 mm) was obtained from a CAD/CAM block (Cerec Blocks; Sirona Dental Systems GmbH, Bensheim, Germany) for color testing. The feldspathic specimen was placed on the resin cement disk and all measurements were performed without cementation. A spectrophotometer was used for color measurements. Specimens were subjected to thermal aging (5 °C and 55 °C; 5000 and 20,000 cycles). Specific color coordinate differences (ΔL, Δa, and Δb) and the total color differences (ΔE00) were calculated after immersion in distilled water for different periods. Normality of data distribution was tested by using the Kolmogorov–Smirnov test. Data were statistically in a model of repeated measures, using multivariate tests and Tukey’s multiple comparison tests at a significance level of p < 0.05. Results ∆E00 values of resin cements were influenced by cycle periods, significantly (p < 0.05). The highest ΔE00 values for long term were obtained in the NX3 (DC) (3.49 ± 0.87) and the lowest in the NX3 (LC) (1.41 ± 0.81). NX3 (LC), Variolink (DC), RELY X (LC) resin cements showed clinically acceptable color change after long-term aging (∆E00 < 1.8). Conclusion Light-cure resin cements should be preferred for long-term color stability of full ceramic restorations.
In this article, we aimed to (1) synthesize novel 3-substitue 2-methyl indole analogs, and (2) evaluate their biological activities against Acetylcholinesterase enzyme (AChE) and Glutathione S-transferase enzyme (GST), (3) predict ADMET and pharmacokinetic properties of the 3-substitue 2-methyl indole analogs (4) reveal the possible interactions between 3-substitue 2-methyl indole analogs and selected enzymes. In vitro enzyme inhibition studies revealed the 3-substitue 2-methyl indole analogs exhibited moderate to good inhibitory activities against AChE and GST enzymes. 2-azido-1-(2-methyl-1H-indol-3-yl) ethanone synthesized was a good inhibitor with the lowest Ki value for both enzymes. Furthermore, a molecular docking study of 3-substitue 2-methyl indole analogs was carried out in the active site of AChE/GST to gain insight into the interaction modes of the synthesized analogs and rationalized structure-activity relationship. The binding energies of the AChE-3- substitue 2-methyl indole analogs’ complexes were found between −9.3 and −6.0 kcal/mol, and the binding energies of the GST-3-substitue 2-methyl indole analogs’ complexes were also found between −11.1 and −7.5 kcal/mol.
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Hanifi Yıldız
  • Department of Chest Disease
Hakan Yilmaz
  • Archaeology
Mustafa Usta
  • Department of Plant Protection
Nihat Mert
  • Department of Biochemistry
Murat Cancan
  • Department of Mathematics
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www.yyu.edu.tr