Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(116)
- Şahin, Engin(48)
- Kaya, Yunus(46)
- Özen, Soner(46)
- İspirli, Hümeyra(45)
- Pat, Suat(44)
- Şenay, Volkan(42)
- Korkmaz, Şadan(36)
- Yilmaz, Mustafa Tahsin(33)
- Kutlu, Naciye(32)
- Cuce, Erdem(31)
- Öner, Erdal(31)
- Artar, Musa(30)
- Ertugrul, Mehmet(29)
- Hasar, Ugur Cem(29)
- Mercan, Emin(28)
- Bayraktar, Bülent(27)
- Bayram, Sinan(27)
- Can, Zehra(25)
- Ecem Bayram, Nesrin(25)
- Çolak, Murat(23)
- Özdemir, Akın(23)
- Cuce, Pinar Mert(22)
- Sert, Durmuş(22)
- Ayata, Ümit(21)
- Bayram, Ozkan(21)
- Dirican, Ebubekir(20)
- Abdioglu, Murat(19)
- Ayazoglu, Rabil(19)
- Birinci, Ahmet(19)
- Kamiloğlu, Aybike(19)
- Gerçek, Yusuf Can(18)
- Taylan, Osman(18)
- Tozlu, Alperen(18)
- Gul, Volkan(15)
- Hasar, Ugur C.(15)
- Kadakal, Mahir(15)
- Sagdic, Osman(15)
- Ergün, Mustafa(14)
- Kadakal, Huriye(14)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ2Relation of ATPase6 Mutations and Telomere Length in Schizophrenia Patients
Uzuncakmak, Sevgi Karabulut; Dirican, Ebubekir; Ozcan, Halil; Takim, Ugur
Objective: Schizophrenia is a serious mental disorder. Mutations in mitochondrial genes can change energy metabolism. Telomere is a tandem sequence at the end of chromosomes. Shorter telomere length has been shown in schizophrenia. The aim of this study was to determine the relationship between ATPase6 gene mutations and telomere length in schizophrenia patients. Methods: Blood samples of 34 patients and 34 healthy controls were used. In this study conventional PCR, Sanger sequencing technic and real-time PCR were utilized. Results: Five different mutations (A8860G, A8836, G8697A, C8676T, and A8701G) in the ATPase6 gene were identified in schizophrenia patients. The most seen mutation was A8860G (94%). Telomere length analysis indicated the relation of ATPase6 gene mutations and telomere length variations (p = 0.001). Patients carrying the A8860G mutation had shorter telomere lengths than patients carrying other mutations. Comparing telomere length between schizophrenia patients and healthy controls revealed that the mean telomere length of schizophrenia patients was shorter than healthy controls (p = 0.006). The demographic analysis demonstrated a significant relationship between marital status and telomere length (p = 0.011). Besides that, the duration of the illness is another factor that impacts telomere length (p = 0.044). There is no significant relation between telomere length and other clinical and demographic characteristics including education status, age, gender, etc. Conclusion: In conclusion, telomere length and ATPase6 gene mutations have a significant relation. Studies with larger patient populations and investigation of other mitochondrial gene mutations will make the clearer link between telomere length and mitochondrial mutations.
AtıfScopus4WoS3OpenAlex4
İncele - MakaleAçık Erişim2023Scopus SJRQ2Investigation of the effects of changes in formulation and cooking times on the quality parameters in the production of goji berry leather
Maraş, R. Talay; Erdoğan, U.
Goji berry (Lycium barbarum L.) is described as a food with several health benefits. This valuable fruit has been processed into fruit leather, which is one of the important traditional products. This study allowed us to determine the effect of changing formulations (starch and flour) and cooking times (10, 15, and 20 min) on quality criteria during goji berry leather production. The goji berry leather samples exhibited the following characteristics: pH values ranging from 4.96 to 4.99, titration acidity values spanning from 2.97% to 3.23%, dry matter content within the range of 84.78% to 87.69%, ash content between 3.12%, and 4.27%, water activity (aw) values ranging from 0.37 to 0.38, protein content between 14.71%, and 15.66%, HMF content varying from 17.33 mg/kg to 34.51 mg/kg, total phenolic content ranging from 7.14 µg GAE/g to 7.89 µg GAE/g, total sugar content falling between 61.18%, and 63.89%, reducing sugar content within the range of 60.13% to 61.89%, sucrose content ranging from 0.91% to 2.25%, thickness values ranging from 0.74 mm to 0.89 mm, hardness values varying between 17.09, and 33.27, stickiness values within the range of 4.10 to 23.34, cohesiveness values from 0.85 to 1.00, elasticity values ranging from 0.88 to 0.97, chewability values spanning from 12.85 to 30.85, L* values ranging from 27.27 to 32.66, a* values between 8.62, and 10.32, b*values varying from 7.06 to 8.59, C* values within the range of 11.15 to 12.81, and H° values falling between 39.31, and 41.13. Following the sensory evaluation of leather samples, it was determined that the color score ranged from 3.80 to 4.27, the smell score fell between 3.53 and 4.00, the taste score varied from 2.93 to 4.00, the mouthfeel score ranged from 2.93 to 3.93, and the general acceptability score was found to be within the range of 3.27 to 4.20. It was determined that cooking time and additional additives affect some quality values of the goji berry leather.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2023Scopus SJRQ2Evaluation of IGFBP5 expression and plasma osteopontin level in COVID-19 patients
Karabulut Uzunçakmak, Sevgi; Aksakal, Alperen; Kerget, Ferhan; Aydın, Pelin; Halıcı, Zekai
Purpose: The aim of this study is to investigate insulin-like growth factor binding protein 5 (IGFBP5) expression in coronavirus disease 2019 (COVID-19) patients and its relationships with COVID-19 laboratory findings and plasma osteopontin (OPN) levels. Materials and methods: We enrolled 60 patients with COVID-19 and 30 healthy individuals in this study. mRNA expression of IGFBP5 was measured by RT-PCR. Plasma OPN levels were measured via the ELISA method. Results: Plasma OPN levels were higher and IGFBP5 expression levels were lower in COVID-19 patients than in the healthy individuals (p = 0.0057 and p = 0.0142, respectively). Critically ill patients had higher OPN and lower IGFBP5 than non-critically ill patients. Patients with affected lungs demonstrated increased OPN and decreased IGFBP5 (p = 0.00032 and p = 0.044, respectively). Receiver operating characteristic (ROC) analysis indicated that IGFBP5 expression and OPN levels can be used discriminate non-critically from critically ill patients (p = 0.049; p = 0.0016, respectively). Conclusion: This study demonstrated that patients with a poor prognosis had increased OPN and decreased IGFBP5. High values of OPN and low values of IGFBP5 may be considered as signs of disease severity. Tissue-specific IGFBP5 expression may contribute to understanding the role of IGFBP5 in the lungs in COVID-19 cases.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2023Scopus SJRQ1Nectar honey from Turkey: crystallization and physicochemical profile
Ecem Bayram, Nesrin
Honey is a traditional food used by humans due to many therapeutic properties. Turkey is in a good position for the production of bee products, and honey is the most popular bee product in the country. In this study, the aim was to evaluate the quality parameters of 40 honey samples based on physicochemical parameters and to gain information about speed of crystallization. For this purpose, moisture (%), fructose (%), glucose (%), fructose + glucose (F + G, %), fructose/glucose (F/G), glucose/moisture (G/M), and proline (mg/kg) contents were determined in honey samples and cluster analysis was performed. When the sugar profile of honey samples is examined, F + G was 61.63–78.03%, F/G was 0.99–1.25, moisture content was 14.9–19.1%, and proline content was 384.41–1271.56 mg/kg. These results comply with national standards. Honey samples tend to crystallize quickly when their crystallization properties are evaluated based on F/G and G/M ratios. Consequently, the quality of honey differs according to the region from which it is produced and it is natural for honey to crystallize.
AtıfScopus4WoS3OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ2Efficient production of acetone butanol ethanol from sole fresh and rotten potatoes by various Clostridium strains
Avcı, Ayşe; Kamiloğlu, Aybike; Dönmez, Sedat
This study aimed to evaluate rotten potato in the fermentation of acetone butanol ethanol (ABE). For this purpose, three strains, Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422, were used and production experiments were performed in a simple media only composed of either fresh or rotten potato. Effects of potato concentration (100–400 g/L) and time (24–144 h) on the fermentation were determined using fresh potato. The highest ABE production was detected at 400 g/L potato concentration at the end of 96 h by all strains. Clostridium acetobutylicum DSMZ 6228 was the most efficient strain in producing ABE among the microorganisms tested. Total ABE productions by Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422 at 400 g/L in 96 h were 12.3, 17.6, and 12.0 g/L, respectively. The majority of the products was butanol that made up ca. 66–67% of total ABE. Significant amounts of ABE were also produced with rotten potato which was compatible with the results obtained with fresh potato. They were determined as 11.5, 17.1, and 9.6 g/L with Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422, respectively. The results showed that rotten potato could be a good candidate as substrate for ABE fermentation.
AtıfScopus18WoS16İncele - MakaleYalnız künye2023Scopus SJRQ2Optimization of microwave-assisted biosynthesis of silver nanoparticle with tarragon extract
Altuncu, Fatma Kübra; Kamiloğlu, Aybike
Response surface method was used to optimize microwave-assisted silver nanoparticle production with tarragon extract. As a result of the optimization study, tarragon silver nanoparticles (TAgNPs) were produced from 43 conditions with a degree of desirability of 1, with a processing time of 5.25 min, AgNO3 concentration of 9.89 mM, and tarragon extract concentration of 14.80%. Among the variable parameters, AgNO3 concentration affected TAgNP synthesis depending on processing time and tarragon extract concentration; tarragon extract concentration was found to significantly affect nanoparticle formation. TAgNP produced under optimum conditions was found to be crystalline, with a spherical surface morphology and an average particle size of 16.56 nm, with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction diffractometry (XRD) analyses. TAgNPs showed inhibitory effect for Escherichia coli BC 1402, Bacillus cereus BC 6830, Salmonella typhimurium RSSK 95091, Yersinia enterocolitica ATCC 27729, and Staphylococcus aureus ATCC 25923 microorganisms. The minimum inhibition concentrations were 10 µg/mL for B. cereus BC 6830, 50 µg/mL for E. coli BC 1402, S. typhimurium RSSK 95091, and Y. enterocolitica ATCC 27729, and 25 µg/mL for S. aureus ATCC 25923.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ2Effect 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.
AtıfScopus30WoS27İncele - MakaleAçık Erişim2023Scopus SJRQ3Comparison of Phenolic Profile and Antioxidant Properties of Pulp and Seeds of Two Different Grapes Types (Vitis vinifera L. and Vitis labrusca L.) Grown in Anatolia: The Amount of Resveratrol of Grape Samples
Kavgacı, Merve; Yukunc, Gulsah Okumus; Keskin, Merve; Can, Zehra; Kolaylı, Sevgi
Background: Grape is the most widely cultivated fruit all over the World and it is both food and a good source of antioxidants. The fruit is rich in phytochemicals and its seed is especially a source for resveratrol, a stilbene that shows health promoting effect. Objective: In this study, phenolic profile and antioxidant properties of eight grape cultivars with two species cultivated in Turkey were compared. Isabella, Razaki, Alphonse Lavalleé, Red Globe and Emir cultivars were used. Methods: Total phenolic substance (TPS), total flavonoid substance (TFS), total antioxidant capacity (FRAP) and phenolic compositions of the pulp and the seeds were determined. Phenolic composition of grapes were found by using HPLC-UV. Results: The results showed that total phenolic substances and total antioxidant capacities were richer in the seeds than in the pulps. Catechin and epicatechin are major phenolic compounds in the grape seeds, and chrysin, pinocembrin, resveratrol, luteolin and caffeic acid phenethyl ester (CAPE) were detected in the pulp as major. Resveratrol varied from 4.50 to 101.89 mg/100 g, while was equally in both the seed and pulp. It was found that all grape samples were rich in phenolic compounds and had antioxidant activity. Conclusion: It was clear that antioxidant capacity and phenolic profile of samples changes according to grape species and cultivars.
AtıfScopus11WoS7OpenAlex10İncele - MakaleAçık Erişim2023Scopus SJRQ1Physicochemical Characterization of Dextran HE29 Produced by the Leuconostoc citreum HE29 Isolated from Traditional Fermented Pickle
İspirli, Hümeyra
In this study, lactic acid bacteria (LAB) strains were isolated from traditional fermented pickles, and among the identified strains, Leuconostoc citreum HE29 with a strong slimy colony profile was further selected to determine the physicochemical and techno-functional properties of its exopolysaccharide (EPS). Glucose was the only sugar monomer in the core unit of EPS HE29 detected by HPLC analysis, and glucan HE29 revealed 7.3 kDa of molecular weight. Structural characterization of glucan HE29 by 1H and 13C NMR spectroscopy analysis demonstrated that EPS HE29 was a dextran-type EPS containing 5.3% levels of (1 → 3)-linked α-D-glucose units. This structural configuration was also supported by FT-IR analysis, which also demonstrated the functional groups within the dextran HE29 structure. In terms of thermal properties detected by TGA and DSC analysis, dextran HE29 demonstrated a degradation temperature of around 280 °C, showing its strong thermal features. A semi-crystalline nature was observed for dextran HE29 detected by XRD analysis. Finally, AFM and SEM analysis revealed tangled network-like properties and web-like branched structures for dextran HE29, respectively. These findings suggest the importance of plant-based fermented products as LAB sources in obtaining novel EPS structures with potential techno-functional roles.
AtıfScopus10WoS9OpenAlex11İncele - MakaleAçık Erişim2023Scopus SJRQ1A 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.
AtıfScopus14WoS14İncele - MakaleAçık Erişim2023Scopus SJRQ3Fatḥ al-Raḥīm al-Raḥmān fī tafsīr Āyat "inna Allāha yaʼmuru bi al-ʻadl wa al-iḥsān" by Abū al-Ḥasan b. ʻAbd al-Raḥmān b. Muḥammad al-Khaṭīb al-Shirbīnī al-Shāfiʻī: Study and Critical Edition; [Ebü’l-Ḥasen b. ʻAbdirraḥmān İbn Muḥammed el-Ḥaṭīb eş-Şirbīnī eş-Şāfiʻī’nin Fetḥu’r-Raḥīmi’r-Raḥmān fī tefsīri Āyeti "innallāhe yeʼmuru bi’l-ʻadli ve’lİḥsān" adlı eseri: İnceleme ve Tahkik]
Aras, Zakir
This study seeks to investigate the treatise of Abū al-Hasan b. Abd al-Rahman b. Muhammad al-Khatīb al-Shirbīnī al- Shāfiʻī (d. after 1028/1619) entitled Fatḥ al-Raḥīm al-Raḥmān fī tafsīr Āyat "inna Allāha yaʼmuru bi al-ʻadl wa al-iḥsān" based on the manuscript of the author. Shedding light on the translation of this unknown scholar, as it is evident from the title of the treatise that it contains the interpretation of this verse, which is well known among scholars and commentators as the most comprehensive verse in the Qur’ān. In this tafsīr, Shirbīnī used many exegetical methods such as exegesis of the Qur'ān with the Qur'ān, exegesis of the Qur'ān with the Sunnah, exegesis of the Qur'ān with the sayings of the Companions, and al-tafsīr bi-al-raʼy, as well as tafsīr approaches such as linguistic tafsīr, the science of munāsabāt, and causality of nuzūl to analyze the meanings of the verse in depth. Another feature that increases the importance of this treatise is that al-Shirbīnī refers to the primary source tafsīr books together with their glosses, sometimes quoting from the commentators verbatim, and sometimes making meaning-based quotations from them, which is the most obvious indication of his exegetical ability and scholarly competence. In this work, he adopted a syncretic approach while emphasizing the meanings of the verse and followed an analytical-critical method while examining the subject. For this reason, he analyzed all the words in the verse one by one, dwelt on the meanings and interpretation of the words, and criticized their views after including the views of the commentators. Therefore, he applied the analytical exegesis method very successfully in this work. Accordingly, he analyzed the narrations related to tafsīr and mentioned the Companions' names during the narration. In particular, he analyzed the narrations from Ibn 'Abbas (d. 68/687-88) about the words al-ʻAdl and al-iḥsān, and stated that there was a dispute between the narrations about the phrase al-iḥsān. He took a scientific stance on the derivation of the word "Allah,” debated between those who accepted it and those who rejected it. He stated that the derivation of the word was not satisfactory and reliable. In the tafsīr of the words al-ʻAdl and al-iḥsān, he discussed the isnāds in Muqātil b. Sulayman’s (d.150/767) tafsīr emphasizing that he received the tafsīr of al-ʻAdl from Ibn 'Abbas and the tafsīr of al-iḥsān from 'Ali b. Abī Tālib. This approach is an important example for the isnād analyses of Muqātil b. Sulayman who was criticized for neglecting isnād chains in his tafsīr. He also criticized al-Baydāwī for being influenced by some of Zamakhsharī's sectarian and theological views. He classified the issue of kinship according to usūl, furū', and hawāshī, expanded the meaning of the verse, and insisted that the message of this verse encompasses all relatives, regardless of the degree of kinship. He was influenced by Latāʾif al-Ishārāt, al-Kashshāf, Mafātīhu al-ghayb, al-Baydawī, Hāshiya al-Jurjānī ala al-Kashshāf, and his grandfather al-Khatīb al-Shirbīnī’s (d.977/1570) al-Sirāj al-munīr.
AtıfOpenAlex2
İncele - MakaleAçık Erişim2023Scopus SJRQ1Diversity of Clostridium spp. causing late blowing in Kaşar cheese and their behaviour against various antimicrobials
Kaya, Halıl Ibrahim; Simsek, Omer; Akgunoglu, Ozlem
One of the problems encountered during storage of Kaşar cheese is blowing. The diversity of Clostridium spp. having a role in blowing was screened and the sensitivity of Clostridium spp. strains against nisin, NaCl, CuSO4, and EDTA was determined and compared. According to 16S rDNA sequence similarity, 12 Clostridium spp. isolates were Clostridium sporogenes while 3 were Clostridium jeddahense. Gas formation by Clostridium spp. spores can be significantly inhibited by reducing the pH below 5.5 and adding 400 IU mL−1 nisin when the number of spores are below 300 spore mL−1. It was determined that the late-blowing problem in Kaşar cheese is caused by C. sporogenes and C. jeddahense strains, but the success of preventive agents is closely related to the amount of spores.
AtıfScopus7WoS4OpenAlex6İncele - MakaleYalnız künye2023Scopus SJRQ2Efficient 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.
AtıfScopus16WoS15OpenAlex14İncele - MakaleYalnız künye2023Scopus SJRQ1Investigation of vibration performance of pure active single and multi-feedback controls for a tall RC building
Uyar, Mehmet; Ergün, Mustafa
Structural control methods are applied to eliminate the structural damages caused by the vibrations in the buildings and to improve their dynamic behavior of them under dynamic lateral loads. In this paper, the pure active control performance of a tall building under the influence of earthquake records, in which the effective time duration is determined by considering the ARIAS energy distribution, is presented. The building's pure active control performance in the period when the earthquake records have the maximum effect on the structure is examined. Eleven earthquake records are selected to better evaluate the effect of vibration control performance. A genetic algorithm is used to determine the parameters of single and multi-feedback controllers, and its effect on the vibration eliminations at the top and all floors is studied. Also, the effect of displacement and velocity feedback on seismic vibration control is evaluated. To carry out the vibration control studies of the building, the mathematical model is extracted from the finite element model created in ANSYS and verified with finite element analysis. It is observed that the displacement value at a reference location on the building is reduced from 0.735 m to 0.019 m, 0.004 m, and 0.002 m, respectively, by the Proportional-Integral-Derivative, Direct Velocity Feedback, and Optimal controllers. The results show that the multi-feedback control is more effective than the single-feedback control application in reducing the vibration amplitudes at all floors in the pure active control system.
AtıfScopus6WoS5OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ3A STUDY ON THE CONTACT PROBLEM OF A LAYER CONSISTING OF FUNCTIONALLY GRADED MATERIAL (FGM) IN THE PRESENCE OF BODY FORCE
Adiyaman, Gökhan; Öner, Erdal; Yaylaci, Murat; Birinci, Ahmet
One of the most important components of the early design process for layered systems is gaining a knowledge of the behavior of materials under varied contact situations. Functionally graded materials (FGMs) have grown in popularity in layered systems as a result of their numerous benefits, such as permitting the reduction of local stress concentrations and thermal stresses often experienced in traditional composites. This paper suggests an analytical approach to solving the continuous and discontinuous contact problems of a functionally graded (FG) layer subjected to a distributed load. Elasticity theory and integral transform methods provide the basis of the aforementioned analytical approach. The FG layer rests on a half-plane that is homogeneous, and there is no adhesion or bonding at the contact surface. For this problem, we assume an exponentially varying shear modulus and mass density in the FG layer. In the solution, the body force of the FG layer is considered. The problem is solved analytically by applying boundary conditions for both continuous and discontinuous contact cases. The presented results show the effects of load factor, amplitude of distributed load, inhomogeneity parameters, and interface material property mismatch on contact stress distributions, initial separation load (critical load), initial separation distance, starting and end point of separation, and separation interval.
AtıfScopus39WoS40OpenAlex30İncele - MakaleAçık Erişim2023Scopus SJRQ2EFFECTS OF ARTIFICIAL WEATHERING ON THE SURFACE PROPERTIES OF COATED RADIATA PINE
Sahin, Sirri; Esteves, Bruno; Can, Ahmet; Sivrikaya, Hüseyin; Domingos, Idalina; Ferreira, José; Ayata, Ümit
Radiata pine boards were coated with two different methods A and B both beginning with a hydro primer and finishing with a mat oil but method A using an acrylic high gloss coating and method B three layers of an acrylic sealer in between. The samples were subjected to aging processes for 144 h, 288 h, and 432 h by using UV-A 340 nm lamps. The CIE L*a*b* and CIE L*C*H* coordinates were determined (L*, a*, b*, C*, ho*, ΔE*), gloss (perpendicular (⊥) and parallel (//) to the grain at 20°, 60°, and 85° angles) and surface adhesion strength via the pull-off method were tested before and after weathering. Results have shown that lightness (L*), decreases with weathering for both varnish applications with a higher decrease for the B coating system. Redness increased for both applications with no significant differences. At the same time there was a yellowing of the samples along the weathering period. Parallel and perpendicular gloss decreased for 20º and 60º angles while it increased for 85º angle. The adhesion strength of method A was higher and its decrease with weathering was smaller than for method B. Both varnish applications have proven to confer some protection against wood discoloration, but method A showed the best results and is therefore the best method to be used by radiata pine.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2023Scopus SJRQ3Seismic response of adjacent buildings interconnected by viscous dampers considering soil-structure interaction
Hatipoğlu, Yavuz S.; Düzgün, Oğuz A.
The effectiveness of fluid viscous dampers (FVDs) on dynamic response mitigation of coupled two adjacent structures was investigated, considering soil-structure interaction (SSI) effects under earthquake excitation. A numerical procedure was employed to evaluate system response. The finite elements were used for the numerical treatment of the adjacent buildings and soil region. Viscous boundary conditions were used as special non-reflecting boundaries on the edges of finite soil region. According to the results, the FVDs were found to be very effective for dynamic response mitigation of the adjacent buildings, even if considering the soil medium. The results showed that the most affecting parameter on the system response was found to be soil type. It was also concluded that when adjacent structures coupled by FVDs, the maximum values of the roof displacements, the base shear forces, and the base bending moments could decrease up to around 50%. Changing in lateral stiffness of the one building has minor effects on the effectiveness of viscous dampers
AtıfScopus5WoS5OpenAlex2İncele - MakaleYalnız künye2023Scopus SJRQ2The melatonin agonist ramelteon attenuates bleomycin-induced lung fibrosis by suppressing the NLRP3/TGF-Β1/HMGB1 signaling pathway
Aydin, Pelin; Aksakalli-Magden, Zeynep B.; Civelek, Maide S.; Karabulut-Uzuncakmak, Sevgi; Mokhtare, Behzad; Ozkaraca, Mustafa; Alper, Fatih; Halici, Zekai
Purpose: The possible effects of ramelteon, a melatonin receptor agonist on bleomycin-induced lung fibrosis were analyzed via transforming growth factor β1 (TGF-β1), the high mobility group box 1 (HMGB1) and Nod-like receptor pyrin domain-containing 3 (NLRP3) which are related to the fibrosis process. Materials and methods: Bleomycin (0.1 mL of 5 mg/kg) was administered by intratracheal instillation to induce pulmonary fibrosis (PF). Starting 24 h after bleomycin administration, a single dose of ramelteon was administered by oral gavage to the healthy groups, i.e. PF + RM2 (pulmonary fibrosis model with bleomycin + ramelteon at 2 mg/kg) and PF + RM4 (pulmonary fibrosis model with bleomycin + ramelteon at 4 mg/kg) at 2 and 4 mg/kg doses, respectively. Real-time polymerase chain reaction (real-time PCR) analyses, histopathological, and immunohistochemical staining were performed on lung tissues. Lung tomography images of the rats were also examined. Results: The levels of TGF-β1, HMGB1, NLRP3, and interleukin 1 beta (IL-1β) mRNA expressions increased as a result of PF and subsequently decreased with both ramelteon doses (p < 0.0001). Both doses of ramelteon partially ameliorated the reduction in the peribronchovascular thickening, ground-glass appearances, and reticulations, and the loss of lung volume. Conclusions: The severity of fibrosis decreased with ramelteon application. These effects of ramelteon may be associated with NLRP3 inflammation cascade.
AtıfScopus9WoS9OpenAlex8İncele - MakaleYalnız künye2023Scopus SJRQ1Parameter extraction method for reflection-asymmetric bianisotropic metamaterial slabs using one-port measurements
Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Hamdullah; Ertugrul, Mehmet; Ramahi, Omar Mustafa
An effective microwave method is developed for extracting electromagnetic properties of bianisotropic metamaterial (MM) slabs. As a non-iterative method, it utilizes only the one-port (air-backed and metal-backed MM slab) scattering (S-) parameter measurements. This is a useful feature especially for vector network analyzers, such as MS46131A, MS46121B, and R60, performing only one-port S-parameter measurements. Electromagnetic properties of a bianisotropic MM slab formed by C-shaped resonators are measured by an X-band (8.2–12.4 GHz) rectangular waveguide setup. The effect of any gap between the short-circuit termination for metal-backed measurements and the end of the MM slab on extracted electromagnetic properties is also examined for evaluating the possible error for proposed method.
AtıfScopus3WoS3OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ2Suberosin Alleviates Sepsis-Induced Lung Injury in A Rat Model of Cecal Ligation and Puncture
Karabulut Uzunçakmak, Sevgi; Halıcı, Zekai; Karakaya, Songül; Kutlu, Zerrin; Sağlam, Yavuz Selim; Bolat, İsmail; Aydın, Pelin; Kılıç, Ceyda Sibel
Background/aims: Sepsis is one of the major problems encountered in intensive care units, causing organ damage and increasing mortality. Suberosin (SBR) is a type of coumarin with antioxidant and anti-inflammatory activities. The goal of this study is to explore the protective effects of SBR on the lungs in a rat model of sepsis. Methods: Male Wistar rats were utilized in this study. A cecal ligation and puncture (CLP) model was applied to induce sepsis. Rats were separated into six groups with nine animals in each group, including healthy control, SBR, CLP, and CLP + SBR (5, 10, and 20 mg/kg) groups. Superoxide dismutase (SOD), glutathione (GSH) enzyme activities, and malondialdehyde (MDA) level were measured via enzyme-linked immunosorbent assay (ELISA). The messenger RNA (mRNA) expressions of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were evaluated by real-time polymerase chain reaction (RT-PCR). Histopathological changes in the lungs were investigated with hematoxylin and eosin (H&E). Results: MDA levels and GSH and SOD enzyme activities were negatively affected in the CLP group, but SBR treatment ameliorated these oxidative stress parameters in the SBR1-3 groups (p< 0.05). The mRNA expressions of TNF-α and IL-1β were increased in the CLP group, and SBR treatment decreased those expression levels in a dose-dependent manner (p < 0.05). Organ damage and necrosis were seen in the CLP group and were alleviated in the SBR3 group. Immunohistochemical (IHC) analysis of lung tissues demonstrated decreased TNF-α and IL-1β immunopositivity in the SBR1-3 groups (p< 0.05). Conclusions: SBR ameliorated sepsis-related lung injury in a dose-dependent manner. This compound has significant potential as a future agent in the treatment of sepsis.
AtıfScopus15WoS11OpenAlex15İncele