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  • MakaleAçık Erişim2025Scopus SJRQ2
    Relation between monocyte to high-density lipoprotein cholesterol ratio and prognosis in recipients after liver transplantation

    Okutan, Serafettin; Saritas, Hasan; Saritas, Serdar; Bulbuloglu, Semra; Guneş, Hüseyin

    Background: The end-stage liver diseases require liver transplantation as the life-saving solution. It is known that monocytes/macrophages and high-density lipoprotein cholesterol (HDLC) have important contributions to the development of hepatic inflammation and oxidative stress before liver transplantation. However, the effect of monocyte/HDL-C ratio (MHR) on clinical progression and outcome in the post-transplant period are not fully understood. Our hypothesis is that the MHR value may be associated with poor vs. good outcomes after liver transplantation. Methods: In our retrospective study, we included 464 liver transplant recipients. Patients' data were extracted from electronic and other paper records in our teaching/research hospital. The MHR values and other blood parameters (creatinine, total protein, albumin, etc.) were expressed as a mean and standard deviation, which were analyzed by the Pearson correlation test. The relationship between graft dysfunction and MHR was determined by ROC curve analysis. Results: The mean age of liver transplant recipients was 45.8 ± 13.7 years. Nineteen percent of patients had liver failure due to Alcoholic Fatty Liver Disease (AFLD) and 34.5 % had liver failure due to hepatitis B virus. At the end of 3 months after liver transplantation, 84.5 % of liver transplant recipients were alive, 5.8 % experienced graft rejection and 5.17 % had an infection. There was a statistically significant improvement in total protein, albumin, liver function tests, and serum creatinine values of the survivors (all p < 0.05). The MHR levels were significantly higher in patients who died after transplantation in comparison to those who survived before and after liver transplantation and these differences were statistically significant (p < 0.01). Conclusion: The increased MHR values of recipients after liver transplantation correlated with their risk of survival. Furthermore, the MHR value increased with increased MELD score and the number of days of hospitalization and was not affected by gender and age. MHR was higher in patients with chronic diseases. Patients with high MHR before and after transplantation should be monitored more closely in the perioperative period.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    ScopusWeb of SciencePubMedİncele
  • MakaleYalnız künye2025Scopus SJRQ1
    Optimization of surface modification parameters of fly ash with high calcium oxide (CaO) content to use as a filling material

    Uçurum, Metin; Özdemir, Akın; Teke, Çağatay

    Fly ash (FA) is the fine-grained waste product obtained by burning coal after being ground to specific sizes in thermal power plants, carried with flue gases, and kept in cyclones or electro-filters. Like every industrial waste, the possibilities of utilizing FA have been investigated, and it can be utilized as an additive in cement and concrete. Despite this, industrial waste, which increases daily in the world, brings many problems, especially environmental problems. For this reason, alternative usage areas of the waste in question are constantly being investigated. In this paper, FA containing approximately 50 % CaO from Afşin-Elbistan, Turkiye was processed with stearic acid in a planetary mill to be used as a filling material in industrial products, and it has a grain size of 68.10 μm on a d50 basis, a specific surface area (SSA) of 176.40 m2/g and a contact angle of 13.89. An optimization and characterization study was conducted to make the hydrophilic surface structure hydrophobic by mechanochemical surface modification. Also, surface modification parameters, such as operational speed (rpm), ball filling ratio (%), FA filling ratio (%), pulp density, stearic acid dosage (% of FA), and modification time (min.) were optimized with the D-optimal experimental design. Based on the optimum surface modification parameters, a coated fly ash (CFA) product was obtained with an active ratio of 99.70 %, a contact angle of 95.06o, a medium size (d50) size of 10.60 μm, and an SSA of 926.90 m2/g.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus8WoS8OpenAlex9
    ScopusWeb of Scienceİncele
  • MakaleYayıncıda açık erişim2024Scopus SJRQ1
    Wet mechanochemical surface modification of calcite employing an integration of conventional design and analytical hierarchy process

    Uçurum, Metin; Özdemir, Akın

    The demand for ultra-fine mineral powders from various industries requires the applications of wet grinding and surface modification. In this study, wet mechanochemical surface modification of micronized calcite (d50 = 4.92 μm) with stearic acid [CH3(CH2)16COOH] was carried out in a planetary ball mill. The seven parameters were specified: ball filling ratio (%), ball size distribution ratio (10 and 15 mm, %), micronized calcite filling ratio (%), pulp solid ratio (wt%), mill speed (rpm), stearic acid dosage (% of micronized calcite) and modification time (min). Then, these parameters were optimized using a conventional experimental design when maximizing the active ratio (%) as a significant value for coated calcite. Besides, the analytical hierarchy process was applied to observe the importance of each parameter. Stearic acid dosage, mill speed, and micronized calcite filling ratio are the top three parameters affecting the active ratio. Next, size distribution, XRF, XRD, SEM, FTIR, TGA-DTA, contact angle, and whiteness measurements were performed on the micronized calcite (MC) and coated micronized calcite (CMC) samples. The final CMC product had a 99.90% active ratio, 2.49 μm mean (d50) particle size, and 101.66o contact angle. Finally, CMC obtained by the surface modification can be used as a filler mineral.

    AtıfScopus6WoS4OpenAlex7
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2024Scopus SJRQ2
    Optical, structural, morphological, and gas sensing properties of Mg-doped α-Fe2O3 thin films deposited by RF and DC magnetron Co-sputtering technique

    Sarıtaş, Sevda; Merhan Muğlu, Günay; Turgut, Erdal; Kundakçı, Mutlu; Yıldırım, Muhammet; Şenay, Volkan

    In this research, Mg-doped hematite (α-Fe2O3) thin films with different Mg-doping concentrations were synthesized on glass substrates using the direct current (DC) and radio frequency (RF) magnetron co-sputtering technique, and the changes of some physical properties due to the concentration of the dopant were investigated. The optical, structural, morphological, and elemental properties of the obtained Mg-doped α-Fe2O3 thin films were determined by X-ray diffraction (XRD) analysis, UV–Vis spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), dispersive X-ray spectroscopy and atomic force microscopy (AFM). XRD analysis revealed that the investigated thin films have a rhombohedral crystal structure. The deposition of films at different DC sputtering voltages caused significant variations in stoichiometry and nanostructure. The thin films' band gap energy values were estimated based on absorption measurements, and results ranged from 2.15 eV to 2.69 eV. Raman peaks were observed between 218 cm−1 and 1305 cm−1. The thin films exhibit uniform surface morphology throughout the substrate according to the SEM images. The low RMS roughness values obtained from AFM images showed that the surfaces of Mg:Fe2O3 thin films are smooth. The Mg-doped α-Fe2O3 thin film doped by 150 W DC voltage exhibited a good gas-sensing response at 300 °C. A remarkably quick response/recovery time was achieved.

    AtıfScopus19WoS13OpenAlex20
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  • MakaleAçık Erişim2024Scopus SJRQ1
    Efficient bioreduction of 4-phenyl-2-butanone to drug precursor (S)-4-phenyl-2-butanol by a whole-cell biocatalyst using a novel hybrid design technique

    Bayhan, Beyzanur; Özdemir, Akın; Dertli, Enes; Şahin, Engin

    Asymmetric synthesis is a critical tactic in pharmaceutical industries for creating chiral medications as it allows an enantiomer to be obtained in synthetic chemistry. The asymmetric bioreduction processes by biocatalysts have shown significant potential in producing chiral alcohols. The amount of substrate and the production method of the biocatalytic synthesis of (S)-4-phenyl-2-butanol ((S)-2) are not still desired levels. Furthermore, the biocatalytic asymmetric reduction of 4-phenyl-2-butanone (1) to (R)- or (S)-4-phenyl-2-butanol did not use any mathematical modeling techniques. In this study, the asymmetric bioreduction of 1 was carried out in this work employing Lactobacillus paracasei BD71 biocatalyst and a novel hybrid design-based optimization approach. By using the hybrid design technique, the optimal circumstances were discovered to be pH = 7, temperature = 29 °C, incubation period = 66 h, and agitation speed = 189 rpm. Also, the enantiomeric excess (ee) and conversion could be 99.15 % and 98.19 %, respectively. Next, (S)-2 was acquired to be ee: 99 %, conversion: >99 %, and yield: 97 % from the optimum bioreduction conditions. Furthermore, 14.08 g of 1 under optimal conditions was entirely transformed into (S)-2 (13.84 g, 97 % isolated yield). This study is the first research attempt to use a biocatalyst and an innovative and new hybrid design-based optimization approach to fabricate enantiopure (S)-2 at a high gram scale. This work has successfully demonstrated that the new hybrid design-based optimization technique is applicable to biocatalytic asymmetric reduction processes.

    AtıfScopus9WoS8OpenAlex5
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  • MakaleAçık Erişim2024Scopus SJRQ1
    Physicochemical and structural characterisation of a branched dextran type exopolysaccharide (EPS) from Weissella confusa S6 isolated from fermented sausage (Sucuk)

    Özpınar, Fatma Beyza; İspirli, Hümeyra; Kayacan, Selma; Korkmaz, Kader; Dere, Sevda; Sagdic, Osman; Alkay, Zuhal; Tunçil, Yunus Emre; Ayyash, Mutamed; Dertli, Enes

    Exopolysaccharide (EPS) producing Lactic Acid Bacteria (LAB) species can be presented in distinct environments. In this study, Turkish fermented sausage (sucuk) was tested for the presence of EPS producer LAB strains and slimy-mucoid colonies were selected for further tests. Among the isolates, Weissella confusa strain S6 was identified and tested for the physicochemical characterisation of its EPS. This strain was found to produce 0.74 g L−1 of EPS in modified BHI medium conditions. Structural characterisation of EPS S6 by 1H and 13C NMR demonstrated that EPS S6 was a highly branched dextran type glucan formed by mainly (1 → 2)-linked α-D-glucose units together with low levels of (1 → 3)-linked α-D-glucose units as branching points. This structure was further confirmed by methylation analysis detected by GC–MS. An average molecular weight of 8 × 106 Da was detected for dextran S6. The FTIR analysis supported the dextran structure and revealed the presence of distinct functional groups within dextran S6 structure. A strong thermal profile was observed for dextran S6 detected by DSC and TGA analysis and dextran S6 revealed a degradation temperature of 289 °C. In terms of physical status, dextran S6 showed amorphous nature detected by XRD analysis. SEM analysis of dextran S6 demonstrated its rough, compact and porous morphology whereas AFM analysis of dextran S6 detected in its water solution showed the irregularity with no clear cross-link within the dextran chains. These technological features of dextran S6 suggests its potential to be used for in situ or ex situ application during meat fermentations.

    AtıfScopus25WoS24OpenAlex29
    ScopusWeb of SciencePubMedİncele
  • MakaleAçık Erişim2024Scopus SJRQ2
    Eugenol alleviates the negative effects of experimental periodontitis and regulates adipokine hormones in rats

    Sevinç Gül, Sema Nur; Özkal Eminoğlu, Didem; Tekçe, Emre; Bayraktar, Bülent; Güven, Leyla; Dilsiz, Alparslan; Yıldırım, Serkan; Sait, Ahmet

    A chronic microbial infection that is mediated by the host's immune system is the cause of periodontal disease. As the world's population grows, phytotherapy is a therapeutic strategy that makes use of a renewable resource that can provide less costly medicines. This study aimed to investigate the therapeutic effects of eugenol administration on periodontitis by examining the effects of eugenol at different doses biochemically, histopathologically, and radiologically in rats with experimental periodontitis. Thirty-two Sprague Dawley male rats were divided into four groups: 1. the healthy control group (CG), 2. The experimental periodontitis group (PG), 3. The experimental periodontitis+10 mg/kg eugenol group (EG10), and 4. the experimental periodontitis+20 mg/kg eugenol group (EG20). Alveolar bone loss was measured using micro-CT imaging. The TNF-α, IL-6, leptin, asprosin, and apelin levels were analyzed in the serum samples of rats. Histological and immunohistochemical analyses were performed. The data were analyzed statistically. The serum TNF-α, IL-6, leptin, asprosin, and apelin levels were found to be statistically significantly lower in the eugenol-applied groups (EG10 and EG20) than in the PG (p < 0.05). There was a statistically significant difference in the TNF-α, IL-6, leptin, asprosin, and apelin levels between the EG10 and EG20 (p < 0.05). In the measurements made using micro-CT imaging, alveolar bone loss was found to be at the lowest FR1 level, and in histopathological analysis, the least inflammation was observed in the EG20. It was concluded that the application of 20 mg/kg eugenol in rats with experimental periodontitis was a safe dose, was beneficial in alleviating bone loss, and had a positive effect on the healing process.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus2WoS2OpenAlex2
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2024Scopus SJRQ1
    Synthesis of flaxseed gum/melanin-based scaffold: A novel approach for nano-encapsulation of doxorubicin with enhanced anticancer activity

    Kumar, Deepak; Pal, Ravi Raj; Das, Neeladri; Roy, Partha; Saraf, Shubhini A.; Bayram, Sinan; Kundu, Patit P.

    Doxorubicin is a powerful chemotherapy medicine that is frequently used to treat cancer, but because of its extremely destructive side effects on other healthy cells, its applications have been severely constrained. With the aim of using lower therapeutic doses of doxorubicin while maintaining the same anti-cancerous activity as those of higher doses, the present study designs nano-encapsulation of doxorubicin by acrylamide grafted melanin as core and acrylic acid grafted flax seed gum as shell (DOX@AAM-g-ML/AA-g-FSG-NPs) for studies in-vivo and in-vitro anticancer activity. For biological studies, the cytotoxicity of DOX@AAM-g-ML/AA-g-FSG-NPs was examined on a cancerous human cell line (HCT-15) and it was observed that DOX@AAM-g-ML/AA-g-FSG-NPs exhibited very high toxicity towards HCT-15. In-vivo investigation in colon cancer-inflicted rat model also showed that DOX@AAM-g-ML/AA-g-FSG-NPs showed better anticancer activity against cancerous cells as compared to free doxorubicin. The drug release behavior of DOX@GML-GFS-NPs was studied at several pH and maximum drug release (95 %) was recorded at pH -7.2, and kinetic data of drug release was follows the Higuchi (R2 = 0.9706) kinetic model. Our study is focussed on reducing the side effects of doxorubicin by its nano-encapsulation in acrylamide grafted melanin as core and acrylic acid grafted flax seed gum that will also enhance its efficiency.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus14WoS14OpenAlex15
    ScopusWeb of SciencePubMedİncele
  • MakaleAçık Erişim2024Scopus SJRQ2
    Interleukin-27 as a novel player in alleviating hepatic steatosis: Mechanistic insights from an in vitro analysis

    Cho, Wonjun; Oh, Heeseung; Abd El-Aty, A.M.; Özten, Ömer; Jeong, Ji Hoon; Jung, Tae Woo

    Interleukin-27 (IL-27) is a recently discovered cytokine that has been implicated in inflammatory and metabolic conditions, such as atherosclerosis and insulin resistance. However, the mechanisms by which IL-27 attenuates hepatic lipid accumulation in hyperlipidemic conditions and counteracts endoplasmic reticulum (ER) stress, a known risk factor for impaired hepatic lipid metabolism, have not been elucidated. This in vitro study was designed to examine the effect of IL-27 on hepatic lipid metabolism. The study included the evaluation of lipogenesis-associated proteins and ER stress markers by Western blotting, the determination of hepatic lipid accumulation by Oil Red O staining, and the examination of autophagosome formation by MDC staining. The results showed that IL-27 treatment reduced lipogenic lipid deposition and the expression of ER stress markers in cultured hepatocytes exposed to palmitate. Moreover, treatment with IL-27 suppressed CD36 expression and enhanced fatty acid oxidation in palmitate-treated hepatocytes. The effects of IL-27 on hyperlipidemic hepatocytes were attenuated when adenosine monophosphate-activated protein kinase (AMPK) or 3-methyladenine (3 MA) were inhibited by small interfering RNA (siRNA). These results suggest that IL-27 attenuates hepatic ER stress and fatty acid uptake and stimulates fatty acid oxidation via AMPK/autophagy signaling, thereby alleviating hepatic steatosis. In conclusion, this study identified IL-27 as a promising therapeutic target for nonalcoholic fatty liver disease (NAFLD).

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus6WoS6OpenAlex6
    ScopusWeb of SciencePubMedİncele
  • MakaleAçık Erişim2024Scopus SJRQ1
    Optimization of mechanochemical surface modification parameters on planetary mill using an I-optimal experimental design

    Özdemir, Akın; Uçurum, Metin

    Several micro-particle-size additives and filler minerals are added to many industrial products, especially plastic, in order to reduce cost and improve mechanical properties and appearance. Also, grinding and surface modification are two fundamental properties of the filler minerals used in plastic products. Notably, Bayburt stone (BS) used as a natural raw material from Bayburt, Türkiye contains 76% SiO2 and 15% Al2O3. In this paper, the hydrophilic surface structure of micronized Bayburt stone (MBS) was made hydrophobe by mechanochemical surface modification using calcium stearate [Ca(C17H35COO)2] in a laboratory-type planetary mill. Next, the optimum conditions of the surface modification design factors, which are (1) ball filling ratio = 30.53%, (2) powder filling ratio = 10.43%, (3) mill speed = 475.91 rpm, (4) chemical dosage = 1.99% of powder, and (5) modification time = 4.83 min., were obtained using the proposed I-optimal design-focused optimization model when predicting the model parameters. In addition, a coated micronized Bayburt stone (CMBS) product with an active ratio (AR) of 99.90% and d10, d50, and d90 values of 1.32 μm, 3.48 μm and 9.55 μm were achieved. Finally, particle size distribution (PSD), thermo-gravimetric and differential thermal analyzer (TG-DTA), Fourier transform infrared (FTIR), scanning electron microscope (SEM), electron dispersive spectrum (EDS), and contact angle analyses were performed on the CMBS product.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus5WoS6OpenAlex6
    ScopusWeb of Scienceİncele
  • MakaleYayıncıda açık erişim2024Scopus SJRQ1
    Multi-method examination of contact mechanics in orthotropic layers under gravity

    Öner, Erdal; Uzun Yaylacı, Ecren; Yaylacı, Murat

    Analyzing the behavior of intelligent unconventional materials under diverse contact scenarios, in comparison to conventional materials, is a critical step in the initial design of engineering systems. This paper presents the development of analytical and numerical approaches for analyzing contact mechanics in a system comprising an orthotropic layer resting on a rigid foundation. Parametric analyses include the consideration of cylindrical and flat punch profiles. Analytical formulation utilizes integral transform methods to convert planar elasticity equations into a Cauchy-type singular integral equation of the second kind. A detailed description of the solution technique for the integral equation is provided, encompassing both the analytical formulation and the required discretization for obtaining the solution. Subsequently, a finite element approach (FEA) is employed to approximate contact bodies using a collection of finite elements, while contact boundaries are approximated by utilizing a set of polygons. Alternatively, the problem is addressed using the Multilayer Perceptron approach, a form of artificial neural network frequently applied in diverse machine learning applications, including scenarios involving contact problems. Finally, the resolution to the problem is achieved by employing the multilayer perceptron (MLP) method. The study yields determinations of contact stresses under the punch, the critical separation load resulting in the detachment of the orthotropic layer from the rigid foundation, and the corresponding separation distance. This analysis considers a range of dimensionless parameters and explored the behavior of diverse orthotropic materials. Comparisons between the results of the analytical method and computations from FEA and MLP reveal the exceptional accuracy attained by all three approaches. As the pioneer study employing three distinct approaches to examine continuous contact mechanics within an orthotropic layer under the influence of gravity, this research constitutes a valuable point of reference for upcoming scholars in the field.

    AtıfScopus50WoS53OpenAlex44
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  • MakaleAçık Erişim2024Scopus SJRQ3
    Machine learning driven optimization and parameter selection of multi-surface HTS Maglev

    Ozkat, Erkan Caner; Abdioglu, Murat; Ozturk, U. Kemal

    This research aims to tackle the challenges posed by precise force measurement for high temperature superconducting (HTS) Maglev systems, including mechanical constraints, step motor limitations, and sensor resolutions. For this aim, six machine learning (ML) models namely Support Vector Machine (SVM), Gaussian Process Regression (GPR), Extreme Gradient Boosting (XGB), Long Short-Term Memory (LSTM), Extreme Machine Learning (EML), and Convolutional Neural Network (CNN) were developed to predict levitation force (Fz) and lateral force (Fx) based on process parameters including permanent magnet width (PMW), field cooling height (FCH), the movement in the z-axis (vertical distance), and the movement in the x-axis (lateral distance). Among six ML models, CNN emerged as the most accurate model, demonstrating smaller root mean square deviation (RMSD) without compromising correlation coefficients. Furthermore, an innovative process window approach was introduced to select process parameters that simultaneously meet the minimum value of Fz and maximum value of Fx, named β1 and β2, set at 90 N and 0 N, respectively. Within this window, PMW of 30 mm and z values less than 10 mm were found to be consistent for all FCH and x values. The novelty of this study is to formulate the optimisation problem in HTS Maglev using the developed ML model by addressing two specific objectives one of which focuses on maximizing Fz while ensuring Fx remains within a defined tolerance (β3), representing the minimum allowable ratio of the levitation force to the total force, and the second problem aims to maximize Fz while obtaining zero Fx. The optimum PMW, FCH, x, and z values were obtained at 30 mm, 30 mm, 4 mm and 5 mm, corresponding to Fz and Fx values of 224.2 N and -53.8 N for option 1. As for option 2, the process parameters were obtained as 28.6 mm, 25.9 mm, 0 mm, and 5 mm, corresponding to Fz and Fx values of 194.2 N and 0 N. It was obtained both experimentally and by the optimization that Fz reaches close its maximum as the Fx gains attractive character. Hence, it is expected that the outcomes of this study will significantly benefit the design of HTS Maglev systems and find valuable applications across various transportation engineering projects.

    AtıfScopus21WoS18
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  • MakaleYalnız künye2024Scopus SJRQ1
    Effective biocatalytic synthesis of enentiopure (R)-1,2-diphenylethanol as a pharmaceutical precursor using whole-cell biocatalyst

    Çakmak, Fadile; Özdemir, Akın; Dertli, Enes; Şahin, Engin

    Optically active alcohols are crucial precursors. 1,2-Diarylethanols and their analogues constitute a significant group of substances of biological significance. The biocatalytic synthesis of (R)-1,2-diphenylethanol ((R)-2), which can be utilized as a precursor to important drugs, is still not at the desired level in terms of substrate amount and production process. This study asymmetrically reduced 1,2-diphenylethanone (1) using the Lactobacillus paracasei BD87E6 biocatalyst and a novel orthogonal quadratic design-embedded optimization approach. The following reaction optimization conditions were determined using the suggested optimization technique: pH = 6, temperature = 31 °C, incubation period = 48 h, and agitation speed=134 rpm. In addition, the reaction conversion was estimated to be 99.38 %, and the product's enantiomeric excess (ee) was estimated to be 99.12 %. Further, (R)-2 was produced with >99 % ee, >99 % conversion, and 98 % yield in the experimental investigation under the established optimum conditions. This study is the first attempt to reduce substrate 1 to (R) or (S)-2 using a mathematical optimization method in the presence of a biocatalyst. Furthermore, on a high-gram scale, 1 (15.70 g) was entirely transformed into (R)-2 (15.54 g, 98 % isolated yield). Notably, this study is also the first to perform the gram-scale production of (R)-2 using a novel optimization approach and a biocatalyst. Finally, the innovative and novel orthogonal quadratic design-embedded optimization technique has been demonstrated as an efficient, cost-effective, and environmentally friendly biocatalytic procedure for synthesizing (R)-2.

    AtıfScopus7WoS7OpenAlex6
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  • MakaleAçık Erişim2024Scopus SJRQ2
    Biochemical and physicochemical characteristics and volatile profiles of Erzincan Tulum cheese coagulated by herb-fortified artisanal lamb rennet

    Arslaner, Ayla; Türkmen, Özgenur

    The characteristics of Erzincan Tulum cheese (ETC), an artisanal ewe-milk cheese and the first cheese with the designation of origin in Türkiye, are closely related to the geographical location of production and the human factors influencing every stage of the production process. This study aims to determine the influence of different coagulants (namely, herb-fortified artisanal lamb rennet (ALR), artisanal calf rennet (ACR), and commercial calf rennet (CCR)) on the biochemical, physicochemical characteristics, and volatile compounds of ETC, produced on the Heybeli plateau of the Erzincan province. Using artisanal rennet increased total solids, fat content, and acidity while decreasing pH and aw values. The highest PTA-SN (soluble nitrogen in 5 % phosphotungstic acid, w/v) and TCA-SN (soluble nitrogen in 12 % trichloroacetic acid w/w) values at the end of the ripening period (day 150 of storage) were observed in the ALR-Cheese (ALR-C). Furthermore, this cheese exhibited the highest rate of lipolysis (P < 0.01). Electrophoretograms revealed that αs-1 and β-casein degradation rates were the most significant in ALR-C. Following the 30th day of storage, the highest counts of lactic acid bacteria (LAB) were found in ALR-C. The most rapid reduction of coliforms, E. coli, and yeast-mold was observed in this sample throughout the storage. Eighty-nine volatile compounds were identified in the samples. Particularly noteworthy, ALR-C exhibited the highest ratios of hexanoic, octanoic, and decanoic acids after 90 days of storage. Additionally, steroid compounds were exclusively detected in this sample. The findings of this research make a substantial contribution to the existing literature concerning rennet types and the aromatic profile of ETC. These aspects are crucial for further investigations to enhance the cheese's quality and safety.

    • SDG 2 · Açlığa Son
    AtıfScopus3WoS3OpenAlex3
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2024Scopus SJRQ2
    Diltiazem and Verapamil: Combined experimental and computational approaches to structural and spectroscopic characterization

    Cinar, Mehmet; Can, Sümeyra; Baris, Özlem; Demirci, Çiğdem Elif

    Diltiazem and Verapamil are two important drug molecules in a separate group of Calcium Channel Blockers. The purpose of this work is to determine and compare the structural and spectroscopic properties of these two molecules using a number of experimental techniques and quantum chemical calculations. Compounds were characterized spectroscopically using FT-IR, Raman, NMR (1H, 13C, and DEPT), and UV–vis methods. Furthermore, the Density Functional Theory (DFT) method, Becke's three-parameter hybrid functional (B3LYP), and the 6–311++G(d,p) basis set were used to determine the ground state geometric structures of molecules, and the spectroscopic properties of the obtained optimum structures were investigated computationally. The optimization studies performed under vacuum circumstances and for the isolated molecules were found to be very close to the experimental results. In fact, r.m.s. values were discovered for Diltiazem and Verapamil with bond lengths of 0.013 and 0.024, and bond angles of 1° and 2°, respectively. The vibration characteristics of the compounds were discovered using the collected FT-IR and Raman spectra, and significant vibrational modes were assigned. After scaling, it was revealed that the quantum chemical data was congruent with the experimental ones, and that the characteristic vibrational modes were appropriately predicted. DFT calculations effectively determine molecules' structures due to internal consistency, despite being slightly distant from experimental data. Theoretical values for carbon and hydrogen atoms are better in agreement with observed values when scaling with 0.92 and 0.90. From the UV–vis spectra, Diltiazem HCl absorbance peaks were found at 207 and 237 nm, whereas Verapamil HCl absorbance peaks were identified at 203, 229, and 278 nm. When the theoretical calculations and experimental findings were compared, the anticipated absorption peaks were found to have shifted nearer the visible area. Furthermore, Hirshfeld surfaces and Molecular Electrostatic Potential surfaces were obtained and analyzed in order to better understand the electronic characteristics. The TDOS and PDOS (total and partial density of state) spectra were also studied. Finally, using the HOMO and LUMO energy values, the critical chemical parameters were evaluated, and it was discovered that both molecules had positive electron affinity and electronegativity values, indicating that they will accept electrons when the electron-nucleus attraction exceeds the electron-electron repulsion.

    AtıfScopus9WoS9OpenAlex9
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  • MakaleYalnız künye2023Scopus SJRQ2
    Yttrium-substituted Co0.5Ni0.5YxFe2-xO4 ferrites as microwave absorbers by investigating structural, magnetic, dielectric, and absorption characteristics

    Teber, Ahmet; Sarac, Mehmet F.

    The effect of Yttrium Substitution on Co0.5Ni0.5YxFe2- xO4 (0.0 ≤ x ≤ 1.0) Ferrites as Microwave Absorbers was investigated to include structural, magnetic, dielectric and X-band absorption properties. The main objective of this work is to enhance microwave absorption properties of materials with interesting dielectric/magnetic behaviors by doping rare earth element of Yttrium based on transition metals. The hydrothermal method was used to create Yttrium (Y) substituted nanoparticles, and the effects of Y-ion substitution on the characteristics, structural, magnetic features were examined by XRD, FT-IR, SEM-EDS, TEM-SAED, and VSM, respectively. Electromagnetic properties were obtained from microwave scattering parameters measured via a metal-backed transmission line and Nicholson-Ross Weir techniques using a vector network analyzer (VNA) in conjunction with an X-band waveguide set. Return loss (RL) values of the samples were obtained from the electromagnetic constitutive parameters (permittivity and permeability). According to the XRD measurements, hexagonal crystal structure of ferrite and YFeO3 as secondary phase nanocrystal sizes are between 11 and 67 nm. Refined structural parameters using Rietveld analysis are carried out using the TOPAS refinement program. A good match was observed between the diffraction patterns obtained and calculated by Rietveld analysis. Moreover, the morphological analyses indicate that the relatively small spherical structures of Ni-Co ferrites particles can be seen to change from spherical to hexagonal-shaped with increasing yttrium concentration. The results of the FT-IR study show that the spinel structure has formed as predicted because the expected range of absorption bands is present. According to magnetic measurements, the coercivity (Hc) results show a modest increase in porosity as the Y-content rises. The results revealed that the minimum RL value and bandwidth vary significantly with the amount of Yttrium in the mixture, indicating that the obtained structures will be useful for broadband microwave applications.

    AtıfScopus10WoS11OpenAlex12
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  • MakaleYalnız künye2023Scopus SJRQ2
    Design, synthesis, antioxidant and anticholinesterase activities of novel isonicotinic hydrazide-hydrazone derivatives

    Aslanhan, Özlem; Kalay, Erbay; Tokalı, Feyzi Sinan; Can, Zehra; Şahin, Engin

    The design and synthesis of hydrazone derivatives are increasing in popularity day by day due to the significant biological activities of this scaffold. In the present study, twelve novel isonicotinic hydrazide-hydrazone analogues were synthesized by the condensation reaction of isonicotinic hydrazide with benzaldehyde possessing sulfonate moiety. The structures of the novel compounds have been characterized in detail using spectroscopic techniques. All compounds have shown inhibitory effects against the AChE enzyme at rates ranging from 21.00 to 59.48%. Among them, compound 5 has exhibited the best inhibitory effect of 59.48% against AChE at a concentration of 0.1 mM. Furthermore, to determine how effective the novel compounds are as antioxidants, FRAP and DPPH studies were also carried out. FRAP values in compounds 1–12 were found to range from 26.989–3415.556 µmol FeSO4.7H2O/mg. They also displayed moderate antioxidant potential in the range of SC50=0.03–87.32 mg/mL compared with the control Trolox (SC50 =0.004) in DPPH radical scavenging activities. It was seen that the AChE inhibition percentages of the compounds were in the range of 23.04–58.10% at 0.1 mM concentration. This is the first research on the synthesis, antioxidant and enzyme inhibition properties of these compounds.

    AtıfScopus43WoS37OpenAlex44
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  • MakaleAçık Erişim2023Scopus SJRQ2
    Effect of elevated temperature on radiation shielding properties of cement and geopolymer mortars including barite aggregate and colemanite powder

    Kök, S.; Türetken, M.S.; Öksüzer, N.; Gökçe, H.S.

    This study aims to investigate the radiation shielding efficiency of cement and geopolymer-based mortars after exposure to elevated temperatures which may happen during the activation process of nuclear reactors. To contribute to the shielding properties, these binders were modified with the substitution of colemanite powder (5 and 10%), and barite aggregate was used to be an alternative to silica sand, as well. The produced specimens were exposed to 300 and 500 °C. While the colemanite powder resulted in significant retardation of setting time up to 183% for cement-based series, a set accelerator effect reaching 67% was found in the geopolymer series. Unlike expectation, the losses in mechanical and shielding properties have become more pronounced in geopolymer mortars at the applied temperatures. In particular, a significant increase reaching 28% in compressive strength of cement series was found after 300 °C exposure. It was noted that cement series with reaching a linear attenuation coefficient of 0.162 cm−1 presented more effective shielding against gamma rays when compared to that (0.134 cm−1) of geopolymers. To moderate thermal neutrons, geopolymer series reaching a linear attenuation factor of 2.799 cm−1, were found to be a more promising alternative according to cement series reaching 2.140 cm−1.

    AtıfScopus30WoS27
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  • MakaleAçık Erişim2023Scopus SJRQ1
    A new approach for high-quality production of UHMWPE by applying powder vibration densification before sintering

    Yilmaz, Galip; Uslu, Emin

    Due to its extreme viscosity, UHMWPE powder requires elevated pressure and temperature settings to ensure a fully solid structure. But a gentle process is vital for reliability in certain applications, such as prosthetic liners. A unique type of large gap, not mentioned in the literature, has been observed to resist closing more than regular gaps due to the number of particles forming a shield against pressure. As a solution, a mechanical vibration treatment of the particles before heating was used to eliminate these particular large gaps. Optimum vibration parameters were found, and the samples' final solid density and mechanical properties increased. The particles' dimensions and coefficient of friction were measured, and their vibration-dependent characteristics were discussed. A custom-made microscope apparatus was used to observe the vibration-induced densification of the particles and the gaps resisting closing.

    AtıfScopus14WoS14
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  • MakaleYalnız künye2023Scopus SJRQ2
    Efficient bioreduction of 1-(furan-2-yl)ethanone into enantiomerically pure drug precursor by Lactobacillus paracasei BD101

    Şahin, Engin

    Asymmetric bioreduction catalyzed by biocatalyst have shown considerable potential in the preparation of chiral alcohols. (R)-1-(furan-2-yl)ethanol ((R)-2) can be used precursor in the synthesis of many naturally bioactive piperidine alkaloids such as (−)-Cassine, (−)-Spectaline, (−)-Carnavaline, Prosafrine and (−)- Prosafrinine. Moreover, (R)-2 a key chiral precursor in the production of α, β-unsaturated δ- lactones, which have antifungal, antibiotic, and cytotoxic effects on human tumor cells. However, the synthesis routes of (R)-2 still pose significant challenges in term of unsatisfactory enantiomeric excess (ee) and gram scale synthesis. In this study, Lactobacillus paracasei BD101 biocatalyst from boza, a cereal-based fermented beverage, for the asymmetric bioreduction of the 1-(furan-2-yl)ethanone (1). Following biocatalytic process optimization, (R)-2 was generated with >99% ee and 97% yield. In addition, 9.9 g of 1 was completely converted into (R)-2 on a gram scale (9.78 g, 97% isolated yield) in 48 h. This is the first report about the fabrication of enantiopure (R)-2 in high gram scale using biocatalyst. The optical purity of (R)-2 produced by asymmetric reduction with L paracasei BD101 was also noteworthy since it was the highest documented to date. This study provides an efficient green process for the biocatalytic synthesis of (R)-2.

    AtıfScopus16WoS15OpenAlex14
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