Yayınlar
Koleksiyondaki öğeler
- Kitap BölümüAçık Erişim2024Phenolic Acids in Pollen
Kostić, Aleksandar Ž.; Gercek, Yusuf Can; Bayram, Nesrin Ecem
Determination of phenolic composition of pollen has been one of the most popular topics over the past decade. Although most research studies focused on bee-collected pollen samples, it was also observed that phenolics, in particular, phenolic acids, are very important as protecting compounds in floral pollen grain, attached to sporopollenin. Based on the collected data a pronounced diversity of phenolic acids and derivatives was observed in pollen samples with different botanical/geographical origin. In total, 23 phenolic acids were identified/quantified in the samples with great predominance of the following ones: caffeic acid (0.04–450 μg/g), ferulic acid (0.27–450 μg/g) and p-coumaric acid (0.14–410 μg/g). However, the highest content was observed for vanillic acid (4985.5 μg/g) in the rape bee-collected pollen (China). In addition, several different derivatives, such as ethers, esters or amides, were also identified in pollen.
AtıfScopus9OpenAlex5
İncele - MakaleAçık Erişim2024Scopus SJRQ1Analysis of cascade vapor compression refrigeration system using nanorefrigerants: Energy, exergy, and environmental (3E)
Yilmaz, Metin; Cimsit, Canan; Keven, Arzu; Karaali, Rabi
Nanorefrigerants are considered the most efficient heat transfer fluids for improving heat transfer properties in the refrigeration and air conditioning equipment. For the first time in this study, energy, exergy, and environmental evaluation (3E) analyses were performed by the addition of different nanoparticles to a low GWP refrigerant pair such as R290/R1233ZDE in a cascade refrigeration system. CNT, CuO, and, TiO2 nanoparticles were added to the refrigerant. The effect of nanoparticles on the cascade refrigeration system was analyzed using a model based on density changes. A detailed thermodynamic analysis was performed of the cascade refrigeration system at different evaporator temperatures and mass ratios. The power consumption of the compressor decreases as the evaporator temperature increases for all types of nanoparticles, resulting in an increase in COP values. The analyses showed that CuO nanoparticles had the highest performance. It has been observed that the energy and exergy efficiency increase as compressor work decreases with increasing mass ratios in all nanorefrigerants. In addition, the results indicated that all nanorefrigerants emit lower monthly CO2 emissions compared to the pure refrigerants. The nanorefrigerants play a crucial role in reducing energy consumption and promoting environmental protection compared to traditional refrigerants.
AtıfScopus16WoS16OpenAlex17
İncele - MakaleAçık Erişim2023Scopus SJRQ2Utilization of Response Surface Methodology in Optimization of Proline Extraction from Castanea sativa Honey
Ecem Bayram, Nesrin; Kutlu, Naciye; Can Gercek, Yusuf
Proline constitutes approximately 85 % of the amino acid composition of honey. Therefore, the quantitative determination of this amino acid in honey samples is used by many national/international authorities to evaluate the quality of honey types. In this study, it was aimed to achieve maximum proline amino acid extraction from honey samples whose botanical origins were confirmed by melissopalynological analysis. For this reason, based on three different spectrophotometric methods used in the literature for proline analysis, proline extraction was optimized with the Response Surface Method (RSM) and Box-Behnken experimental design. Three independent variables were determined as treatment time (2, 6, and 10 min), treatment temperature (22, 46, and 70 °C), and cooling time (5, 25, and 45 min). As a result of the optimization, it was seen that only significantly effective independent variable on the proline content of honey was the processing temperature. The optimum conditions obtained as a result of the RSM were found to be 2 min for the treatment time, 70 °C for the treatment temperature and 45 min for the cooling time. The composite desirability of the optimum conditions (R2) was found to be 1.00. It was determined that the method proposed by International Honey Commission (IHC) is efficient for proline analysis, but it provides more proline extraction by reducing of time from 10 min to 2 min in hold time in boiling water bath only during the extraction step. As a result, the conditions to be used in order to achieve maximum proline extraction with different spectrophotometric methods were determined and optimum values were determined. In addition, since the botanical origin of honey samples significantly affects the proline content of honey, it can be suggested that this study be optimized for different monofloral honey samples as well.
AtıfScopus7WoS4OpenAlex8
İncele - MakaleAçık Erişim2024Scopus SJRQ1The application of deep eutectic solvents for protein extraction from bee bread (Perga)
Ecem Bayram, Nesrin; Gerçek, Yusuf Can; Kutlu, Naciye; Çelik, Saffet; Bayram, Sinan; Baştürk, Fatma Nur; Yıldırım, Nazlıcan
Bee bread is one of the basic nutrients that bees use as a protein source and is formed as a result of the fermentation of bee pollen. In the last few years, this product has become increasingly recognized and consumed among bee products due to its functional properties. However, deep eutectic solvents (DES) have attracted great interest in recent years as promising green alternatives to replace traditional solvents due to their variable viscosity, low vapor pressure, application-specific adjustability, non-flammability and chemical stability. In this study, bee bread was extracted in 12 different DES with different hydrogen bond acceptor (HBA):hydrogen bond donor (HBD) combinations. The DES combination with the highest total protein content was determined to be choline chloride (ChCl)-urea. Then, ultrasonic extraction conditions were optimized for maximum bioactive extraction in extracts prepared with ChCl-urea. The optimum conditions were found as 31.3 %, 25 min, 35 °C for ultrasonic power, extraction time and temperature, respectively. The desirability value (d) of the model was 0.83. The extracts were analyzed for total phenolic content, total protein content, individual polyphenolics, individual amino acids and individual vitamins as well as antimicrobial and antioxidant activity tests. According to the results, total protein, total individual amino acids and total individual phenolics were higher in the extracts obtained with ChCl-urea compared to the extract prepared with conventional solvent (ethanol). In conclusion, all these findings showed that ChCl-urea combination can be an alternative to ethanol depending on the structural characteristics of the target compounds to be extracted from bee bread.
AtıfScopus15WoS12OpenAlex13İncele - MakaleAçık Erişim2022Scopus SJRQ3IoT-TDMA: A performance evaluation of TDMA scheme for wireless sensor networks with Internet of Things
Kosunalp, Selahattin; Kaya, Yunus
This article focuses on the design and implementation of an improved version of TDMA scheme for wireless sensor networks (WSNs) exploiting the Internet of Things (IoT) phenomena. The main motivation behind this work is to create an environment for WSNs to benefit from IoT opportunities. An extensive review of the state-of-the-art medium access control (MAC) approaches proposed for IoT is carried out underlying their basic principles and features. An adaptation of TDMA strategy, called IoT-TDMA, is proposed to enhance the channel performances particularly throughput and latency. To test the performance of IoT-TDMA practically, a low-cost node hardware with the capability of Internet connection is essentially designed. IoT-TDMA has been implemented on real-world highly scalable single-hop and multi-hop topologies. Performance results indicate significant improvements in terms of channel throughput and end-to-end delay in comparison to a recently proposed efficient MAC scheme.
AtıfScopus17OpenAlex18İncele - MakaleYalnız künye2024Scopus SJRQ3Microwave hydrodistillation of Pelargonium graveolens L’Her leaves: Essential oil profile, phytochemical composition of wastewater, histo-anatomical structure
Boztaş, Kadir; Gercek, Yusuf Can; Türer, Gizem; Canlı, Deniz; Bayram, Sinan; Çelik, Saffet; Kırkıncı, Seran; Basturk, Fatma Nur; Feizollahi, Sepideh; Cevahir Öz, Gül
By-products with remarkable bioactive properties are formed in extraction processes of essential oils from plant materials. In present study, it was aimed to determine the concentration of individual phenolic and organic acid compounds by LC-MS/MS of the by-product (wastewater) collected after the essential oil isolation from Pelargonium graveolens L. and to determine some bioactive properties of this by-product. In addition, the chemical analysis and antibacterial activity of the essential oil extracted from P. graveolens were determined and the histo-anatomical characterization of the glandular trichomes in the leaf sample was performed. As a result, quercetin (95862.22 μg/kg), myricetin (59834.32 μg/kg) and rutin (36522.90 μg/kg) were the phenolic compounds determined in the highest concentrations in the by-product extracted using two different extraction techniques (non-hydrolysis and hydrolysis methods). Moreover, the individual organic acids of the by-product screened in LC-MS/MS was found to be 4487.17 mg/kg in total. When the essential oil component profile of the plant sample was examined, the citronellol (38.78%) compound was found to be dominant, and it was also detected that the essential oil had remarkable bioactive properties. In conclusion, it can be stated that both the essential oil obtained from P. graveolens and the by-product obtained during essential oil isolation can be considered as a source of some bioactive components in many different industrial applications.
AtıfScopus6WoS4OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1The Effect of Augmented Reality Technology on Primary School Students’ Achievement, Attitudes Towards the Course, Attitudes Towards Technology, and Participation in Classroom Activities
Sökmen, Yavuz; Sarikaya, İsmail; Nalçacı, Ahmet
The research aims to investigate the impact of augmented reality (AR) technologies developed within the framework of primary school students’ on student achievement, attitudes towards the course, attitudes towards technology, and participation in classroom activities. The contents of AR-based learning materials have been developed by 4th-grade teachers and writers within the context of the existing curriculum. The study process was carried out based on the instructional design model. The research was performed in conjunction with the quasi-experimental design among the experimental designs of quantitative research methods. Using the cluster random sampling method, students in the experimental and control groups were selected among 11 primary schools. The findings indicate that contrary to the students in the control group, the students in the experimental group had higher academic achievement and participation in classroom activities, and also their attitudes to the course and applied technology were more positive. Moreover, concerning the experimental group students, a positive and significant correlation between their academic achievements, attitudes towards the course, attitudes towards technology, and their participation and participation in classroom activities have been observed.
AtıfScopus24WoS16OpenAlex21İncele - MakaleAçık Erişim2024Scopus SJRQ2Biochemical 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.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2023Validity and Reliability Study of Listening Attitude Scale for Prospective Teachers
Kaplan, Kadir
The aim of this study is to develop a measurement tool to measure the listening/watching attitudes of pre-service teachers. 387 pre-service teachers were administered the scale, and its validity and reliability studies were conducted by exploratory factor analysis, internal consistency measurement, and confirmatory factor analysis. EFA revealed that the scale has four dimensions. To determine the reliability of the scale, the Cronbach Alpha internal consistency coefficient was calculated at 0.928. In the principal component analysis, Kaiser-Meyer-Olkin (KMO) coefficient was found to be 0.937. In addition, the Barlett Sphericity test was significant (χ2 = 4607.552; p<0.05). Varimax rotation resulted in factor loadings ranging between 0.37 and 0.91. In CFA, the standardized regression coefficients averaged around 0.700 and the items in each dimension had a significant predictive power. As a result of the analysis, a valid and reliable scale was obtained.
AtıfScopus1İncele - MakaleYalnız künye2024Scopus SJRQ3Exploring the Potential of Isoindole-1,3-Dione Derivatives as Novel Inhibitors of Aldose Reductase: An In Silico and In Vitro Insight into Therapeutic Strategies for Diabetic Complications
Şengül, Bülent; Gündoğdu, Özlem; Kilinç, Namık; Kishali, Nurhan
This study explores the potential of isoindole-1,3-dione derivatives as novel inhibitors of aldose reductase (AR), focusing on their in silico and in vitro effects for therapeutic strategies against diabetic complications. Aldose reductase, a critical enzyme in the polyol pathway, plays a significant role in glucose metabolism and has been linked to diabetic complications. In this comprehensive study, isoindole-1,3-dione derivatives were synthesized and evaluated for their inhibitory effects on the recombinant human AR enzyme. The compounds’ inhibitory activities were measured both in vitro and through in silico techniques, employing molecular docking and free binding energy calculations and ADME studies. The newly synthesized compounds demonstrated varied inhibitory effects, with ethyl and phenyl substituents at specific positions enhancing inhibitory activity. Notably, compounds with carboxylic acid derivatives exhibited potent inhibitory effects, especially compound 6 with an IC50 value of 1.649 μM. In conclusion, this study provides valuable insights into the inhibitory potential of isoindole-1,3-dione derivatives against AR, suggesting their potential therapeutic application in mitigating diabetic complications. The combination of experimental and computational approaches offers a comprehensive understanding of the compounds’ interaction mechanisms and pharmacokinetic profiles, supporting their further exploration as antidiabetic agents.
- MakaleYalnız künye2024Scopus SJRQ1Mindfulness-based cognitive therapy for adherence of immunosuppressive treatment in liver transplant recipients: A randomized controlled trial
Bulbuloglu, Semra; Gunes, Hüseyin
Objective: The aim of this study was to analyze the effects of mindfulness-based cognitive therapy on the adherence of liver transplant recipients to immunosuppressive therapy with a randomized controlled design. Method: This randomized controlled trial was performed with 120 liver transplant recipients hospitalized at the liver transplant department of a research and practice hospital (n = 120). While we administered no intervention to the patients in the control group (n = 60), we provided Mindfulness-Based Cognitive Therapy to those in the experimental group (n = 60). We used the Mindful Attention Awareness Scale and the Immunosuppressant Therapy Adherence Scale to collect data. We utilized descriptive statistics, paired-samples t-tests, independent-samples t-tests, one-way analysis of variance, and chi-squared tests to analyze the data. Results: After the intervention, the immunosuppressive therapy adherence levels of the experimental group increased significantly (p < 0.01). On the other hand, the control group had significantly higher adherence to immunosuppressive therapy and significantly higher levels of mindfulness in the pretest phase than it did in the posttest phase (p < 0.01). Conclusions: Complete adherence to immunosuppressive therapy is imperative for the prevention of graft rejection in liver transplant recipients. In our study, the experimental group equipped with enhanced mindfulness had higher adherence to immunosuppressive therapy. Therefore, the use of Mindfulness-Based Cognitive Therapy in the promotion of adherence to immunosuppressive therapy is recommended.
AtıfScopus6WoS5OpenAlex7İncele - MakaleAçık Erişim2023Scopus SJRQ3Optimization of asymmetric bioreduction conditions of 1-(thiophen-2-yl)ethanone by Weissella cibaria N9 using a desirability function-embedded face-centered optimization model
Bolubaid, Mohammed; Özdemir, Akın; Dertli, Enes; Alamoudi, Mohammed; Taylan, Osman; Karaboğa, Derviş; Yılmaz, Mustafa Tahsin; Şahin, Engin
Prochiral ketones can be effectively bio-reduced to chiral secondary alcohols by whole-cell biocatalysts, which are possible useful precursors to synthesize physiologically active chemicals and natural products. When whole-cell biocatalysts strains are used, bioreduction process can be influenced by various cultural factors, and it is vital to optimize these factors that affect selectivity, conversion rate, and yield. In this study, Weissella cibaria N9 was used as whole-cell biocatalyst for bioreduction of 1-(thiophen-2-yl)ethanone, and cultural design factors were optimized using a desirability function-embedded face-centered optimization model. For this, effects of pH (4.5–5.5–6.5, x 1), (2) temperature (25–30–35 °C, x 2), (3) incubation period (24–48–72 h, x 3), and (4) agitation speed (100–150–200 rpm, x 4) on two response variables; (1) ee (%) and (2) cr (%) were tested. Next, desirability function-embedded face-centered optimization model revealed that a pH of 6.43, a temperature of 26.04 °C, an incubation period of 52.41 h, and an agitation speed of 150 rpm were the optimum levels and the estimated ee and cr responses were 99.31% and 98.16%, respectively. Importantly, the actual experimental ee and cr responses were similar to the estimated values indicating the capability of the offered desirability function-embedded face-centered optimization model when using the optimum cultural conditions.
AtıfScopus1WoS1OpenAlex3İncele - MakaleAçık Erişim2024Scopus SJRQ2Cross-cultural adaptation and psychometric evaluation of the Turkish version of the Smombie Scale for Adolescents
Sönmez Sari, Ebru; Temel Mert, Zeynep; Semerci Çakmak, Vahide; Sevgil Atli, Pelin
Background: Smombie has become an important problem especially in terms of adolescent health. The aim of this study was to translate the Smombie Scale for Adolescents (SSA) into Turkish and to examine its psychometric properties. Methods: This study has a methodological design. The study was conducted between March and April 2024. The sample of the study consisted of 430 adolescents. The data were collected by using Personal Information Form and SSA. Content Validity Index, Confirmatory Factor Analysis (CFA), test−retest reliability, Cronbach's α coefficient, item-total score correlation, 27% upper−lower group item analysis and Hotelling T2 test were used in data analysis. Results: The four-factor structure of the scale showed a good fit in CFA (chi-square minimum discrepancy [CMIN] = 187.463, degrees of freedo (DF) = 83, CMIN/DF = 2.259, root mean square error of approximation = 0.054, root mean square residual = 0.033, goodness of fit index = 0.947, adjusted goodness of fit index = 0.923, normed fit index = 0.930, tucker-lewis index = 0.949 and comparative fit index = 0.959). Cronbach's α coefficient of the scale was found to be 0.86. The item-total score correlation of the scale was found between 0.212 and 0.721. The test-retest intraclass correlation coefficient of the scale was found to be 0.876. Conclusions: This study shows that the scale is a reliable tool for assessing adolescents' smombie tendencies. It is thought that the scale will contribute to the protection and development of adolescent health.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ1Examining the attitudes of sexually abused and non-abused individuals towards marriage in terms of ambivalent sexism
Çelik, Eyüp; Dombak, Kübra; Kaya, Mehmet; Sahranç, Ümit; Makas, Samet; Koçak, Lokman; Takunyacı, Mithat; Bekir, Seyhan
The research aims to examine the attitudes of individuals who are victims of abuse and those who are not towards marriage in terms of ambivalent sexism. The research study group consists of 718 individuals between the ages of 18–48. Research data were collected with the Inonu Marriage Attitude Scale and Ambivalent Sexism Inventory. As a result of the correlation analysis, it was concluded that the marriage attitude was positively and significantly correlated with hostile and protective sexism. However, since the relationship between hostile sexism and attitudes towards marriage is lower than that of protective sexism, hostile sexism was not included in the model as a control variable. In the covariance analysis, it is seen that protective sexism and sexual abuse predict the attitude towards marriage at a statistically significant level. In addition, when the effect of sexual abuse on the attitude towards marriage was examined by controlling the protective sexism variable, it was found that it was statistically significant without the effect of sexism. According to the findings, it was determined that individuals who were not victims of sexual abuse had higher attitudes towards marriage than those who were victims. Copyright:
AtıfScopus4WoS5OpenAlex4İncele - MakaleAçık Erişim2024Scopus SJRQ2Investigation of the effect of green walking and intelligence games on the cognitive skills of individuals between the ages of 50–70 survived COVID-19 disease: A randomized controlled study
Akeren, Zahide; Hintistan, Sevilay
Background: Mild cognitive impairment can be considered as the preclinical stage of Alzheimer's disease. With the addition of COVID-19 disease to the cognitive decline that occurs with aging, it may cause dementia with severe cognitive losses such as Alzheimer's disease in some people. Physical activity and brain-occupying practices can significantly improve the risk factors for cognitive disorders and Alzheimer's disease. Objective: The aim of study was to examine the effect of green walking and intelligence game on the cognitive skills of individuals aged 50–70 years with COVID-19. Methods: The randomized controlled study was completed with 40 individuals, 20 in the experimental and 20 in the control group. Individuals in the experimental group green walking for 30 min three days a week for one month in two groups of 10 people, accompanied by the researcher. In addition, these individuals played intelligence games (brain games-memory thinking and brain exercise) via their smartphones for 15 min every day for a month. Results: The cognitive skills and cognitive dimensions of “attention, concentration, memory, language and orientation” of the individuals in the experimental group were significantly increased compared to the control group individuals (p < 0.05). Conclusions: It was found that green walk and intelligence game practice increased the cognitive skills of individuals aged 50–70 years who had outpatient COVID-19. © The Author(s) 2024. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).
AtıfScopus1WoS2OpenAlex2İncele - MakaleYalnız künye2022Scopus SJRQ1Effect of using hybrid nanofluids as a coolant on the thermal performance of portable thermoelectric refrigerators
Mert Cuce, Pinar; Cuce, Erdem; Guclu, Tamer; Shaik, Saboor; Alshahrani, Saad; Ahamed Saleel, C.
This study investigated the effect of using hybrid nanofluids as a refrigerant in portable thermoelectric refrigerator applications on thermal performance. For this purpose, a cooling cabinet with an internal volume of 36 L was designed and produced. Then, the Peltier assembly, with a water-cooled block attached to its hot surface, was placed in this cooling cabinet from the middle of its front cover. With the help of a refrigerant, the heat was removed from the Peltier's hot surface and transferred to the atmosphere via a water-to-air heat exchanger. Hybrid nanofluids prepared with Al2O3-TiO2-SiO2 and nanoparticles and water were used as the refrigerant in the system. To evaluate the thermal performances of these hybrid nanofluids, the tests were repeated using water without added nanoparticles as the reference case. According to the results obtained from the experimental study, it was observed that in all cases, tests using nanofluids gave better results than the reference cases. In addition, it was determined that the efficiency obtained from the system increased as the nanoparticle ratio in the mixture increased in all cases. Despite significant improvements in cooling cabinet and cooled product temperatures in hybrid nanofluids, the COP values of the systems are slightly lower than in the reference case due to the Peltier effect. Considering the difference between the first and last temperatures of the cooled cabinet, the greatest improvement compared to the reference situation was determined as 30.3 % in the case of loaded state conditions and in the case of using 2 % Al2O3-TiO2-SiO2-Water nanofluid. For the unloaded conditions, this value was obtained as 25.1 % in the case of using 2 % Al2O3-TiO2-SiO2-Water nanofluid. On the other hand, for the unloaded condition, the lowest COP value was calculated as 0.47 and 0.45 when Al2O3-TiO2-SiO2-Water nanofluid was used in 1 % and 2 % mass fraction, respectively. For the loaded condition, this value was found as 0.48 in the case where 1 % Al2O3-TiO2-SiO2-Water and 0.47 in the case where 2 % Al2O3-TiO2-SiO2-Water nanofluid was used.
AtıfScopus27WoS21İncele - MakaleAçık Erişim2023Scopus SJRQ1Structural characterization of potato starch modified by a 4,6-α-glucanotransferase B from Lactobacillus reuteri E81
Hassanein, Wael S.; İspirli, Hümeyra; Dertli, Enes; Yilmaz, Mustafa Tahsin
The recent reports have revealed that increase in amount of α-1,6 linkages by modification of potato starch with enzyme (glycosyltransferases) treatment gains slowly digestible properties to the starch; however, the formation of new α-1,6-glycosidic linkages diminish the thermal resistance of the starch granules. In this study, a putative GtfB-E81, (a 4,6-α-glucanotransferase-4,6-αGT) from L. reuteri E81 was firstly used to produce a short length of α-1,6 linkages. NMR results revealed that external short chains mostly comprised of 1–6 glucosyl units were newly produced in potato starch, and the α-1,6 linkage ratio was significantly increased from 2.9 % to 36.8 %, suggesting that this novel GtfB-E81 might have potentially an efficient transferase activity. In our study, native and GtfB-E81 modified starches showed fundamental similarities with respect to their molecular properties and treatment of native potato starch with GtfB-E81 did not remarkably change thermal stability of the potato starch, which seems to be very prominent for the food industry given the significantly decreased thermal stability results obtained for the enzyme modified starches reported in the literature. Therefore, the results of this study should open up emerging perspectives for regulating slowly digestible characteristics of potato starch in future studies without a significant change in the molecular, thermal, and crystallographic properties.
AtıfScopus14WoS14OpenAlex18İncele - MakaleYalnız künye2022Scopus SJRQ1Global boundedness of solutions to a quasilinear parabolic-parabolic Keller-Segel system with variable logistic source
Ayazoglu, Rabil
This paper deals with the higher dimension quasilinear parabolic-parabolic Keller-Segel system involving a source term of variable logistic type ut=∇⋅(ϕ(u)∇u)−∇⋅(ψ(u)∇υ)+g(x,u), −Δυ=−υ+u, in (x,t)∈Ω×(0,T), subject to nonnegative initial data and homogeneous Neumann boundary condition, where Ω is a smooth and bounded domain in RN (N≥1) and g∈C1(Ω‾×[0,∞)) function satisfies g(x,s)≤ηsk(x)−μsm(x),s>0 with g(x,0)≥0, x∈Ω and η≥0,μ>0 are constants, k,m are measurable functions with 1<k−:=ess infx∈Ωk(x)≤k(x)≤k+:=esssup k(x)x∈Ω<+∞, 2≤m−:=ess infx∈Ωm(x)≤m(x)≤m+:=esssup m(x)x∈Ω<+∞. Positive functions ψ,ϕ∈C2([0,∞)) satisfy νsq≤ψ≤χsq and ϕ≥σsp with p,q∈R, ν,χ,σ>0 when s≥0. It is proved that if q=m−−1 (critical case) and [Formula presented] then there exists a classical solution which is global in time and bounded. Moreover, if q∈(k+−1,m−−1), we obtain that there is a classical solution of the above system uniformly in time bounded without any restrictions on m− and μ.
AtıfScopus10WoS8OpenAlex10İncele - MakaleAçık Erişim2024Scopus SJRQ3The effect of injectable platelet-rich fibrin in combination with autogenous bone grafts on bone healing in an ovariectomized osteoporotic rat model with critical-sized defects
Durmuşlar, Mustafa C.; Gülşen, Elif A.; Bayburt, Kemal A.; Ballı, Umut; Ocak, Mert; Fırat, Ayşegül; Zırh, Elham B.; Çelik, Hakan H.
OBJECTIVES: To assess the impact of autogenous graft materials, including autogenous bone graft (ABG) and injectable platelet-rich fibrin (I-PRF) clots, on bone defect regeneration in ovariectomized osteoporotic rats. METHODS: Wistar rats (6-8 weeks old) were ovariectomized, and surgery began after 8 weeks. A 5-mm defect was created bilaterally in the parietal bones of 16 rats, which were divided into 4 groups. Group A (blank) had untreated defects; group B had defects filled with 0.1 ml of I-PRF, group C had defects filled with 0.1 ml of ABG, and group D had defects filled with a combination of 0.1 ml each of I-PRF and ABG. Four weeks post-surgery, the rats were euthanized. Bone regeneration was evaluated through histopathologic analysis and microcomputed tomography (micro-CT). RESULTS: In ovariectomized rats treated with ABG or I-PRF, bone regeneration was enhanced, with increased periosteal activity, osteoblast count, and new bone volume, as determined histologically. The ABG+I-PRF group had the highest periosteal vascularity, but the difference compared to the ABG group was not statistically significant (p>0.05). Osteoblast numbers were significantly higher in the ABG+I-PRF group than in the blank group (p<0.05). Micro-CT showed the highest mean new bone volume ratio in the ABG+I-PRF group, followed by the ABG group. CONCLUSION: The combined use of ABG and I-PRF enhances bone formation in osteoporotic rats following ovariectomy. Copyright:
AtıfScopus2OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Drought analysis using innovative trend analysis and machine learning models for Eastern Black Sea Basin
Niazkar, Majid; Piraei, Reza; Eryılmaz Türkkan, Gökçen; Hırca, Tuğçe; Gangi, Fabiola; Afzali, Seied Hosein
This study aims to assess the Eastern Black Sea Basin drought conditions. For this purpose, the trend changes in SPI values of 6, 9, 12, and 24 months using innovative trend analysis were examined. Additionally, four machine learning models, including Multiple Linear Regression, Artificial Neural Networks, K Nearest Neighbors, and XGBoost Regressor, are employed to forecast SPI with rainfall data between 1965 and 2020 from eight rainfall stations. The input data for each model was SPI values from lead times of 1 to 6, resulting into 768 unique scenarios. The ML models estimated SPI values better as the SPI duration increased, with the 24-month SPI showing the highest accuracy. The results of SPI forecast indicated that the optimal model and number of input variables varied for each SPI and station, indicating that further studies are required to improve SPI predictions.
AtıfScopus24WoS23OpenAlex25İncele
