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    4-vinylpyridine and 2-hydroxyethylmethacrylate monomer mixture graft copolymerization onto poly(ethylene terephthalate) fibers using benzoyl peroxide
    (Springer, 2007) Yigitoglu, Mustafa; Arslan, Metin
    Poly(ethylene terephthalate) (PET) fibers were grafted with 4-vinyl pyridine (4-VP) and 2-hydroxyethylmethacrylate (HEMA) using benzoyl peroxide (Bz(2)O(2)) as initiator in aqueous media. PET fibers were swelled in dichloroethane (DCE) for 2 h at 90 degrees C to promote the incorporation and the subsequent polymerization of 4-VP/HEMA onto PET fibers. Variations of graft yield with time, temperature, initiator concentration and monomer mixture ratio were investigated. The optimum initiator concentration was found to be 8x10(-3) mol/L. The maximum graft yield was obtained 280%. The optimum temperature and polymerization time was found to be 85 degrees C and 100 min. respectively. The rate of grafting was found to be proportional of the 1.5 and 0.3 powers of 4-VP/HEMA and Bz(2)O(2) concentrations, respectively. The grafted PET fibers were characterized by thermo gravimetric analysis and scanning electron microscopy (SEM). Further changes in properties of grafted PET fibers such as water absorption capacity, intrinsic viscosity and diameter were determined. The dye ability of the PET fibers increased with an increase in grafting with diazo and basic dyes.
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    Adsorption behavior of congo red from an aqueous solution on 4-vinyl pyridine grafted poly(ethylene terephthalate) fibers
    (John Wiley & Sons Inc, 2008) Arslan, Metin; Yigitoglu, Mustafa
    In this study, a reactive fibrous adsorbent was prepared through the grafting of 4-vinyl pyridine monomer onto poly(ethylene terephthalate) (PET) fibers for the removal of Congo red (CR) dye from an aqueous solution with the batch adsorption method. Effects of various parameters such as the grafting yield, pH, treatment time, and initial dye concentration on the amount of adsorption of the dye onto the reactive fibers were investigated. The effective pH was 4.0 for adsorption on grafted PET fibers. The sufficient time to attain equilibrium was 150 min. The maximum adsorption capacity of the reactive fibers for CR was 17.3 mg/g of fiber. The rates of adsorption conformed to pseudo-second-order kinetics with good correlation. The adsorption isotherm of CR fit a Langmuir-type isotherm. The reactive fibers were stable and regenerable by acid and base without loss of activity. (c) 2007 Wiley Periodicals, Inc.
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    Adsorption behaviour of copper (II) ion from aqueous solution on poly(4-vinyl pyridine)
    (2002) Yiğitoğlu, Mustafa; Arslan, Metin; Temoçin, Zülfikar
    The adsorption behaviour of poly(4 - vinyl pyridine) towards copper (II) ion in aqueous solutions was studied by a batch equilibriation technique. Influence of treatment lime, pH of the solution and metal ion concentration on the adsorption were investigated. 45 minutes of adsorption time was found sufficient to reach adsorption equilibrum for the copper (II) ion. The optimum pH was found to be 4,5. The adsorption saturation value was reached at 1,27 mmol ions per gram poly(4 - vinyl pyridine) against 3.15 mM copper (II) ions. It was observed that the adsorption isotherm of Cu (II) fits Freundlich - type isotherms.
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    Adsorption behaviour of copper(II) ion from aqueous solution on 4-vinyl pyridine grafted poly(ethylene terephthalate) fibers
    (2002) Yiğitoğlu, Mustafa; Arslan, Metin; Şanlı, Oya; Ünal, Halil İbrahim
    The adsorption behaviour of 4 vinyl pyridin grafted poly (ethylene terephthalate) fibers was studied towards the copper (II) ions in aqueous solutions by a batch equilibriation technique. The influence of treatment time, temperature, pH of solution, metal ion concentration and percent graft yield on adsorbed amount were investigated. One and half an hour of adsorption time was found sufficient to reach adsorption equilibrium for copper(ll) ions. It was found that the adsorption isotherm of Cu(II) ions fits to Langmuir type isotherms. The highest adsorption capacity was found to be 0.973 m m o I copper(ll) ion per gram adsorbant. The heat of adsorption value was calculated as -9.57 kj mol1. It was found that the reactive fibers are stable and regenerable by acid treatment without losing its activity.
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    Adsorption behaviour of methylene blue from aqueous solution on poly(ethylene terephthalate)-g-4-vinylpyridine/2-hydroxyethylmethacrylate fibers
    (Walter De Gruyter Gmbh, 2007) Yigitoğlu, Mustafa; Arslan, Metin
    In this study, a novel fibrous adsorbent obtained by grafting 4-vinyl pyridine (4-VP)/2-hydroxyethylmethacrylate ( HEMA) comonomers onto poly ( ethylene terephthalate) ( PET) fibers was used for removal of methylene blue (MB) from aqueous solutions through a batch equilibration technique. The Influence of treatment time, pH of the solution, dye concentration, reaction temperature and percent graft yield on adsorbed amount were investigated. 300 min. of adsorption time was found sufficient to reach adsorption equilibrium for MB. It was found that the adsorption isotherm of MB fitted to Langmuir type isotherm. The highest adsorption capacity was found to be 55.33 mg MB per gram adsorbent. The adsorbed amount of MB was much higher on the comonomers grafted PET fibers than on the ungrafted PET fibers. MB was removed by 98 % while the initial dye concentration was at 5 mg L-1 and by 88% at 300 mg L-1 by monomers mixture grafted PET fibers. It was found that the reactive fibers were stable and regenerable by acid without loosing their activity.
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    Anyonik Boyaların Giderilmesi için 4-VP-g-PET Lif ve N-Oksit Türevinin Sentezi
    (2017) Arslan, Metin; Günay, Kübra
    Bu çalışmada, 4--vinil piridin (4--VP) aşılanmış Poli(etilen tereftalat) (PET) lifler oksitlenerek asit viyolet (AV7) boyasının adsorpsiyonu için kullanılmıştır. Bu amaçla 4--VP aşılanmış PET lifler N--oksitlenme yapılarak boya adsorpsiyonu farklı deneysel koşullarda araştırılmıştır. AV7 adsropsiyonuna ortam pH's1, boyanm başlangıç derişimi ve sürenin etkileri incelenmiştir. Ayrıca boya adsorpsiyonu yapılmış PET liflerin desorpsiyonu ve tekrar kullanılabilirliği de incelenmiştir. Bu çalışma sonucunda aşağıdaki bulgular elde edilmiştir. 4--VP aşılanmış PET liflerin oksitlenenleri, 4--VP aşılanmış PET liflere göre önemli miktarda daha fazla boya adsorplamıştır. N--oksit--4--VP--g--PET lifinin maksimum adsorpsiyon kapasitesi 22 mg g--l olarak gözlenmiştir. N--oksit--4--VP-- g--PET lif üzerine adsorpsiyon için optimum pH bulunmuştur. Adsorplanan AV7 boyasmın tamamına yakını (%60) aşılanmış PET liflerden desorbe edilmiştir. Ard arda 10 kez tekrarlanan adsorpsiyon-desorpsiyon işlemi ile aşılanmış PET liflerin adsorpsiyon kapasitesinde önemli bir azalma olmadan tekrar kullanılabilirliği gözlenmiştir.
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    Bazı ağır metal iyonlarının 4-vinil piridin ve 2-hidroksietilmetakrilat aşılanmış poli(etilen tereftalat) lifleri ile uzaklaştırılması
    (Kırıkkale Üniversitesi, 2008) Arslan, Metin; Yiğitoğlu, Mustafa
    Bu çalısmada ilk olarak, benzoil peroksit (Bz2O2) baslatıcısı kullanılarakpoli(etilen tereftalat) (PET) lifler üzerine 4-Vinil piridin/2-hidroksietilmetakrilatmonomer karısımı sulu ortamda asılanmıstır (4-VP/HEMA-g-PET). PET liflerpolimerizasyon ortamına alınmadan önce dikloretan (DCE) içerisinde90°C'de 2 saat süre ile sisirilmistir. Asılama yüzdesinin polimerizasyonsüresi, sıcaklık, baslatıcı derisimi ve monomer karısım oranıyla degisimiincelenmistir. Optimum baslatıcı derisimi 8x10-3 mol/L bulunmustur.Maksimum asılama yüzdesi %280 olarak belirlenmistir. Optimum sıcaklık veasılama süresi sırasıyla 85°C ve 100 dakika bulunmustur. Asılama hızının 4-VP/HEMA karısım derisimine 1,5, Bz2O2 derisimine ise 0,3'üncü derecedenbaglı oldugu bulunmustur. Asılanmıs PET lifler, diferansiyel taramalıkalorimetresi (DSC), taramalı elektron mikroskobu (SEM) ve FTIRspektroskopisi ile karakterize edilmistir. Asılanmıs liflerin bazı özelliklerindekidegismeler örnegin su absorplama kapasitesi, intrinsik viskozite degerleri veçapları belirlenmistir.Reaktif lifler kullanılarak sulu çözeltiden Cr(VI), Cu(II) ve Cd(II)iyonlarının uzaklastırılması kesikli (batch) yöntem kullanılarak yapılmıstır.Reaktif liflerin metal iyonlarını adsorplama kapasitesi üzerine pH, ası yüzdesi,adsorpsiyon süresi, iyon derisimi ve adsorpsiyon sıcaklıgı gibi degisikparametrelerin etkileri arastırılmıstır. Ayrıca reaktif liflerin iyon seçiciligi dearastırılmıstır. Adsorplanan iyon miktarlarının Cr(VI)>Cd(II)>Cu(II) seklindeoldugu görülmüstür. Cr(VI) iyon derisimi 5 ppm'den 400 ppm'eyükseltildiginde yüzde uzaklastırma 99'dan 94'e düstügü görülmüstür.Asılanmıs PET liflerin pH 3 de Cr(VI)-Cu(II), Cr(VI)-Cd(II) ve Cr(VI)-Cu(II)-Cd(II) çözelti karısımlarında Cr(VI) iyonlarına karsı seçiciligi daha fazlaoldugu saptanmıstır.
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    Cadmium Induced Changes on Growth Performance, Some Biochemical Parameters and Tissue in Broilers: Effects of Vitamin C and Vitamin E
    (Academic Journals Inc, 2011) Cinar, Miyase; Yigit, A. Arzu; Yalcinkaya, Ilkay; Oruc, Ertan; Duru, Ozkan; Arslan, Metin
    This study was performed to determine the effects of vitamin C (vit C) and vitamin E (vit E) on growth performance, some biochemical parameters and tissue changes in broiler chickens exposed to cadmium (Cd). One hundred twenty, 1-day-old, Ross broiler chicks were divided into 4 groups with 3 replicates and fed with a basal diet (control) or the basal diet supplemented with 60 mg kg(-1) Cd, 60 mg kg(-1) Cd+400 mg kg(-1) vit C, or 60 mg kg(-1) Cd+250 mg kg(-1) vit E for 42 days. Body weight (BW), Body Weight Gain (BWG) and Feed Consumption (FC) were recorded and feed conversion ratio (FCR) was calculated. Plasma were analysed for aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyltransferase (GGT) activities and total protein, total cholesterol and creatinine levels. Cadmium significantly decreased the BW (p<0.001), BWG (p<0.001), FC (p<0.001) and FCR (p<0.05) compared with the control group. Regarding the same groups plasma and kidney Cd (p<0.001) and AST (p<0.05) and GGT activities (p<0.01) were increased. While growth performance were not affected in vit C and vit E supplementated group compared with the Cd-only group, these treatments reduced plasma Cd and GGT activities. Furthermore vit C was more effective in reducing Cd accumulation in kidneys and liver.
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    Cerrahi sütür uygulamaları için poli(hegzametilen biguanid) immobilize edilmiş emilmeyen ve antimikrobiyal PET fiber: sentez, karakterizasyon ve in vitro sitouyumluluk değerlendirmesi
    (Kırıkkale Üniversitesi, 2024) Bozkaya, Ogün; Günay, Kübra; Bozkaya, Esra; Arslan, Metin
    Cerrahi sütürler, cerrahi müdahalelerden sonra yaraları kapatmak amacıyla yaygın olarak kullanılan tıbbi cihazlardır. Cerrahi prosedürler sırasında, sütürler çevredeki mikroorganizmalarla temas ederek bakteriyel biyofilmlerin gelişmesine ve ardından cerrahi alan enfeksiyonlarına (CAE) yol açabilir. Bu nedenle bakteri tutunmasını ve kolonizasyonunu engelleyen sütürlerin kullanılması yara iyileşmesinde oldukça önemlidir. CAE oluşumunu en aza indirmek için triklosan ve klorheksidin gibi antiseptiklerle kaplı antimikrobiyal sütürler kullanılmıştır. Ancak çeşitli antiseptiklere ve antibiyotiklere dirençli bakteri suşlarının ortaya çıkması nedeniyle alternatif antimikrobiyal sütürlerin geliştirilmesine yönelik yeni yaklaşımlar gereklidir. Antimikrobiyal ajanlar arasında, poliheksanid (poliheksametilen biguanid, PHMB) geniş spektrumlu antibakteriyel ve antifungal aktiviteye sahip, düşük toksisiteli ve biyouyumlu katyonik bir antiseptiktir. Bu çalışmada cerrahi dikiş ipliği olarak kullanılmak üzere PHMB immobilize edilmiş polietilen tereftalat (PET) liflerin sentezlenmesi amaçlanmıştır. Sentezlenen modifiye PET lifler SEM, FTIR, DSC ve TGA ile karakterize edilmiştir. Bunlara ek olarak modifier PET liflerin ıslanabirliği ve in vitro degradasyon profili araştırılmıştır. Antimikrobiyal etkinlik testleri için S. aureus ve E. coli bakteri suşları kullanılmıştır. Materyallerin in vitro hücre-uyumluluğu (sitotoksisitesi) TS EN ISO 10993-5 standardına göre MTT testi ile değerlendirilmiştir.
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    Coating of modified poly(ethylene terephthalate) fibers with sericin-capped silver nanoparticles for antimicrobial application
    (Springer, 2020) Gok, Zehra Gun; Gunay, Kubra; Arslan, Metin; Yigitoglu, Mustafa; Vargel, Ibrahim
    In this work, a kind of amine-type PET fibers was synthesized by reacting hexamethylenediamine (HMDA) with methacrylic acid-g-poly(ethylene terephthalate) (PET-g-MAA) fibers for the adsorption of silk sericin-capped silver nanoparticles (S-AgNPs) to produce antimicrobial fibers. Firstly, PET fibers were grafted MAA by using free radical polymerization technique and HMDA was covalently connected to the grafted PET fibers. Then, for S-AgNPs synthesis, 10 mL of AgNO3 solution (1 mM, 5 mM and 10 mM) was mixed with 10 mL of 1% sericin solution at pH 11. The obtained solution was stirred at room temperature for 24 h. The color change from transparent to yellow-brown indicated the formation of S-AgNPs. AgNPs formation was also determined by measuring the absorbance spectra of S-AgNPs between 300 and 600 nm using UV-Vis spectrophotometer. To determine the antimicrobial properties of S-AgNPs, agar-well diffusion tests were performed. 5 mM and 10 mM S-AgNPs groups showed antimicrobial activity on Escherichia coli and Staphylococcus aureus. After characterization of the synthesized S-AgNPs with UV-Vis spectrophotometer, Zetasizer, FTIR and TEM, the modified PET fibers were coated with S-AgNPs (5 mM and 10 mM). The S-AgNPs coated PET fibers were characterized by FTIR, SEM and X-ray fluorescence spectroscopy. The antimicrobial activities of the obtained PET fibers were investigated on S. aureus and E. coli bacteria by using disk diffusion test. It was found that the S-AgNPs coated modified PET fibers exhibited antimicrobial activities toward both gram-positive and gram-negative bacteria. The resulting polymeric PET fibers containing nano-silver can be used as an antimicrobial surface for many applications such as wound dressing.
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    Cu(II) iyonlarının, 4-vinil piridin aşılanmış poli (etilen teraftalat) lifler üzerine adsorpsiyon özelliğinin incelenmesi
    (Kırıkkale Üniversitesi, 2000) Arslan, Metin; Yiğitoğlu, Mustafa
    Cu (D) İYONLARININ, 4-VINIL PIRIDIN AŞILANMIŞ POLI(ETELEN TERAFTALAT) LİFLER ÜZERİNE ADSORPSİYON ÖZELLİĞİNİN İNCELENMESİ ÖZET Bu çalışmanın birinci bölümünde 4 - vinil piridin (4 -VPy) monomeri, benzoil peroksit (Bz202) başlatıcısı kullanarak poli(etilen teraftalat) (PET) liflere aşılandı. Lifler polimerizasyon ortamma alınmadan önce dikloretan (DCE) içerisinde 90°C'de 2 saat süre ile şişirildi. Aşılama yüzdesinin polimerizasyon süresi, sıcaklık, başlatıcı ve monomer derişimiyle değişimi incelendi. Optimum sıcaklık ve aşılama süresi sırasıyla 50 °C ve 2 saat bulundu. Monomer derişimi 0,1 M' dan 0,6 M' a ve başlatıcı derişimi 0 M dan 2x1 0"3 M a kadar artırıldığında aşılama yüzdesinin arttığı gözlendi. Aşılama için aktivasyon enerjisi 20,33 kcal/mol olarak hesaplandı. Aşılama başlangıç hızının monomer derişimine 1,82 başlatıcı derişimine 0,76 dereceden bağlı olduğu bulundu. Aşılanmış liflerin su tutma kapasiteleri ile intrinsik viskozite değerleri hesaplandı. Çalışmamn ikinci bölümünde 4- VPy aşılanmış poli(etilen teraftalat) (PET) liflerin adsorpsiyon özellikleri incelendi. Aşılanmış PET lifler üzerine Cu2+ iyonlarının adsorpsiyonu batch (kesikli) metodu kullanılarak çalışıldı. Adsorpsiyona iyon başlangıç derişiminin, adsorpsiyon süresinin, pH, sıcaklık ve aşı yüzdesinin etkileri araştırıldı. Adsorpsiyon izotermlerinin Langmuir tipi adsorpsiyon izotermlerine uyduğu belirlenmiştir. Cu2+ iyonların maksimum adsorpsiyon kapasitesi 0.973 mmol/g polimer olarak bulundu, adsorpsiyon ısısı ise -9.6 kj/mol olarak hesaplandı. Anahtar kelimler: Aşı Kopolimerizasyon, Adsorpsiyon, Poli(Etilen Teraftalat), Lif, 4 - Vinil Piridin, Cu2+ İyonu
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    Effective adsorption of bovine serum albumin by polyethylene terephthalate (PET) fibers modified with glycidyl methacrylate grafting, hexamethylenediamine attachment and Cu2+ adsorption
    (Springer, 2023) Tastan, Samet; Gunay, Kubra; Arslan, Metin; Yigitoglu, Mustafa; Gok, Zehra Gun
    In this work, the glycidyl methacrylate-grafted (GMA) PET fibers were modified with hexamethylenediamine (HMDA) attachment and Cu2+ adsorption to synthesize an effective adsorbent for removal of bovine serum albumin (BSA) from the aqueous environment. The original PET fibers were grafted with GMA monomers (PET-g-GMA) at 30%, 50%, 100%, 150% and 200% grafting yields, and HMDA was covalently connected to the fibers through to the epoxy groups. The obtained fibers were characterized with the scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and nuclear magnetic resonance spectroscopy (C-13-NMR) techniques. Afterward, Cu2+ ions were adsorbed to graft copolymers modified with HMDA and it was observed that the protein adsorption ability of Cu2+ ions containing fibers increased. In the adsorption study performed with PET-g-GMA and PET-g-GMA fibers modified with HMDA, the highest Q value was found to be 1.7 and 1.98, respectively, while this value was found to be 16.4 for HMDA-modified PET fibers containing Cu2+ ions. In the adsorption experiments, it was observed that the fibers with the highest BSA adsorption capacity were those modified (with HMDA and Cu2+) PET-g-GMA fibers that have 200% grafting yield. The effects of various parameters on BSA adsorption with the fibers with the highest adsorption capacity were investigated. In the experiment carried out with the selected fibers, pH optimization was made in the range of pH 3-9 and the optimum pH value was found to be pH 5. The Q value of the fiber at this pH was found to be 24.85 mg/g. During the adsorption process carried out at pH 5, it was found that the amount of adsorbed BSA reached equilibrium after the 9 h. Temperature optimization was carried out between 25 and 55 & DEG;C at optimum pH and incubation time. Q values were found as 24.8 mg/g at 25 & DEG;C, 44 mg/g at 35 & DEG;C, 47 mg/g at 45 & DEG;C and 22 mg/g at 55 & DEG;C. According to these results, the temperature at which the maximum adsorption took place was determined as 45 & DEG;C. In the next step where the initial protein concentration upon adsorption was investigated, it was concluded that the fibers reached saturation after an initial concentration of 200 ppm BSA concentration. As a result of the desorption study carried out for 2 h in acetate buffer containing 1 M NaCl at 25 & DEG;C, it was observed that approximately 85% of the loaded protein desorbed from the fibers after 75 min. It has been seen that the modified PET-g-GMA fibers used as adsorbent in this study can be used in separation and purification processes of BSA by adsorption process, due to its advantages such as high production, low cost, high processability, and easy modification.
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    The effects of rosiglitazone and metformin on menstrual cyclicity and hirsutism in polycystic ovary syndrome
    (Taylor & Francis Ltd, 2005) Yılmaz, Murat; Karakoç, Ayhan; Toruner, Füsun B.; Çakır, Nuri; Tiras, Bülent; Ayvaz, Göksun; Arslan, Metin
    Objective. The aim of the present study was to assess the effects of metformin and rosiglitazone on menstrual cyclicity and hirsutism in patients with polycystic ovary syndrome (PCOS). Materials and methods. Ninety-six patients were included in the study. Serum sex steroids, serum fasting glucose and insulin levels, and insulin response to a 75-g oral glucose tolerance test were assessed in all patients. Menstrual cyclicity, with recording of menses in the 6-month periods before the study and during treatment, was evaluated in each patient. Patients were divided into two groups: one was treated with metformin (MET group, n = 48), while the other received rosiglitazone (ROSI group, n = 48). At baseline and after 24 weeks of treatment all patients underwent hormonal and clinical assessments, including body mass index (BMI), waist and hip measurements and Ferriman - Gallwey (FG) scores. Results. Of the 96 patients included in the study, 88 (91.7%) were able to complete it and yielded data for analyses. After the 24-week treatment period, fasting insulin levels and area under the curve for serum insulin decreased significantly, while the glucose/insulin ratio increased in both groups. The degree of reduction in serum free testosterone and androstenedione levels was similar in the two groups. The decreases in luteinizing hormone/follicle-stimulating hormone ratio and serum clehydroepiandrosterone sulfate levels were significantly greater in the ROSI group compared with the MET group. BMI increased in the ROSI group, while it decreased in the MET group. In patients with menstrual disturbance treated with rosiglitazone, menstrual cycles became regular in 87.8%, while improvement occurred in 79.3% of the patients treated with metformin. FG score decreased in both ROSI and MET groups, but the degree of decrease was significantly greater in the ROSI group than in the MET group. Conclusion. Our data show that both metformin and rosiglitazone improve ovarian function and hirsutism in patients with PCOS. Rosiglitazone appears better than metformin in the treatment of hirsutism and has better patient tolerance.
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    The effects of rosiglitazone and metformin on oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome
    (Oxford Univ Press, 2005) Yılmaz, Murat; Bukan, Neslihan; Ayvaz, Göksun; Karakoç, Ayhan; Törüner, Füsun; Çakır, Nuri; Arslan, Metin
    BACKGOUND: Oxidative stress and hyperhomocysteinaemia are risk factors for cardiovascular diseases. The aim of this study was to assess the effects of rosiglitazone and metformin on cardiovascular disease risk factors such as insulin resistance, oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome (PCOS). MEHODS: Fifty lean patients (BMI < 25 kg/m(2)) with PCOS and 35 healthy subjects were included this study. Serum homocysteine, sex steroids, fasting insulin, fasting glucose and lipid levels were measured. Total antioxidant status (TAS; combines concentrations of individual antioxidants) and malonyldialdehyde concentration (MDA) were determined. Insulin resistance was evaluated by using the homeostasis model insulin resistance index (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), Area under the curve insulin (AUCI) and the insulin sensitivity index (ISI). Patients were divided into two groups. One group was treated with metformin (n = 25) and the other received rosiglitazone (n = 25) for 12 weeks. All measurements were repeated at the end of 12 weeks. RESULTS: Compared with healthy women, those with PCOS had significantly elevated serum MDA, homocysteine, HOMA-IR, AUCI and lipoprotein a levels, and significantly decreased serum TAS, QUICKI and ISI. Serum free testosterone levels showed a significant positive correlation with MDA, AUCI and HOMA-IR, and a negative correlation with TAS, ISI and QUICKI in PCOS patients. HOMA-IR and AUCI significantly decreased, while QUICKI and ISI significantly increased after treatment in both groups. Serum TAS level increased and serum MDA level decreased after the rosiglitazone treatment, but these parameters did not change after the metformin treatment. Serum homocysteine and lipid levels did not change in either group, while serum androgen levels and LH/FSH ratio significantly decreased after the treatment period in only the rosiglitazone-treated group. CONCLUSION: Elevated insulin resistance, oxidative stress and plasma homocysteine levels and changes in serum lipid profile (risk factors for cardiovascular disease) were observed in lean PCOS patients. Rosiglitazone seemed to decrease elevated oxidative stress when compared with metformin treatment in lean PCOS patients.
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    Efficient removal of cationic dyes from aqueous solutions using a modified poly(ethylene terephthalate) fibers adsorbent
    (TAYLOR & FRANCIS INC, 2020) Unlu, Nuri; Gunay, Kubra; Arslan, Metin
    A novel adsorbent was synthesized through functionalization of glycidyl methacrylate-g-poly(ethylene terephthalate) (GMA-g-PET) fibers with iminodiacetic acid (IDA) to give IDA-GMA-g-PET fibers. This adsorbent was then exploited for the removal of Malachite Green (MG) and Rhodamine B (RB) dyes. MG has shown faster adsorption kinetics and equilibrium was attained in 15 mins. and 90 mins. for MG and RB, respectively. IDA-GMA-g-PET fibers showed 100% removal efficiency for MG and RB dyes from the solutions having initial concentrations of 300 mg L(-1)and 200 mg L-1, respectively. Desorption conditions of dyes and reusability of the fibers were also investigated.
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    Elimination of carcinogenic bromate ions from aqueous environment with 4-vinyl pyridine-g-poly(ethylene terephthalate) fibers
    (Springer Heidelberg, 2019) Gunay, Kubra; Arslan, Metin; Bozkaya, Ogun; Aluc, Yasar; Gok, Zehra Gun
    In this study, poly(ethylene terephthalate) fibers grafted with 4-vinyl pyridine (PET-g-4VP) was synthesized with using a radical polymerization method and its removal capacity for bromate ions in the aqueous solution was explored. The synthesized graft copolymer was structurally characterized by scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). The effect of some parameters such as pH, grafting rate, processing time, and ion concentration on bromate removal was examined with batch experiments. The sorptions of bromate onto the PET-g-4VP fibers were both verified with FTIR and X-ray fluorescence analysis (XRF) and the remaining amount of bromate after adsorption process was determined with an ion chromatography (Shimadzu). Moreover, kinetic and isotherm studies were also performed for adsorption of bromate with the grafted fibers. The point of zero charge (pH(pzc)) of the PET-g-4VP fibers was found to be 7.5 and the fibers removed maximum amount of bromate from aqueous solution at pH 3. Equilibrium time of adsorption was determined to be 75 min and the adsorption kinetic was found to be pseudo-second-order model. It was observed that the increase in the amount of grafted 4VP onto the PET fibers increased the bromate removal capacity of the fibers; however, when the grafting yield of 4VP was over 80%, the bromate removal ability of the fibers decreased. The maximum bromate removal capacity of the PET-g-4VP was determined to be 183 mg/g when the initial bromate amount was 800 mg/L, treatment time was 75 min, pH of the solution was 3, and 4VP grafting yield was 80%. When the initial bromate concentration was higher than 800 mg/L, the removal rate of the PET-g-4VP fibers was not changed. In addition, bromate ion adsorption data indicated compliance with the Freundlich isotherm. The adsorbent fibers obtained by this study may be promising candidates for the removal of bromate ions from the aqueous media.
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    Glucose intolerance, insulin resistance and cardiovascular risk factors in first degree relatives of women with polycystic ovary syndrome
    (Oxford Univ Press, 2005) Yılmaz, Murat; Bukan, Neslihan; Ersoy, Reyhan; Karakoç, Ayhan; Yetkin, İlhan; Ayvaz, Göksun; Arslan, Metin
    BACKGROUND: The aim of the present study was to evaluate insulin resistance (IR), glucose tolerance status and cardiovascular risk factors in first degree relatives of patients with polycystic ovary syndrome (PCOS). METHODS: A total of 120 family members [Mothers(PCOS) (n=40), Fathers(PCOS) (n=38), Sisters(PCOS) (n=25) and Brothers(PCOS) (n=17)] of 55 patients with PCOS and 75 unrelated healthy control subjects without a family history of diabetes or PCOS (four age- and weight-matched subgroups, i.e. Control(Mothers), Control(Fathers), Control(Sisters) and Control(Brothers)) were studied. IR was assessed by homeostatic model assessment (HOMA IR), log HOMA, insulin sensivity index (ISI), the quantitative insulin sensitivity check index (QUICKI) and area under the curve for insulin during the oral glucose tolerance test (AUCI, AUCG) in with normal glucose tolerance (NGT) subjects and controls. Serum adiponectin, resistin, homocysteine and lipid levels were measured. RESULTS: The prevalence of any degree of glucose intolerance was 40% in Mothers(PCOS) and 52% in Fathers(PCOS). In total, six (15%) glucose tolerance disorders were identified in the Control(Mothers) and Control(Fathers) in first degree relatives of control subjects. The first degree relatives of PCOS patients had significantly higher serum fasting insulin, HOMA-IR, Log HOMA and AUCI levels in all subgroups than the control subjects. The control subjects had significantly elevated QUCKI, ISI levels and serum adiponectin levels compared to the first degree relatives of PCOS subjects in all subgroups. The serum Hcy and resistin levels increased significantly in both Fathers(PCOS) and Mothers(PCOS) groups but not Brothers(PCOS) and Sister(PCOS). CONCLUSION: The results of the present study support the finding that the first degree relatives of PCOS patients carry an increased risk of cardiovascular disease, as do PCOS patients.
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    Heavy metal accumulations of Allium cepa L. as a bioindicator for air pollution in Eregli, Turkey
    (Academic Journals, 2011) Atabay, Meltem Maras; Kekillioglu, Aysel; Arslan, Metin
    Eregli, a province with iron-steel industrial activities, is situated on the coast of Black Sea in Northwestern Anatolia. Heavy metal pollution caused by industrial activities is a threat to environmental quality and human health. Allium cepa L. is a bioindicator due to its sensitivity to environmental pollution. Fe, Hg, Zn, Hg, Cr showed greater accumulation in its leaves in four different sampling points. A significant decrease at Hg and Pb concentrations was not seen in its leaves. This study showed that the leafy plants contaminated with toxic heavy metals during industrial activities and Eregli's air quality has been poor.
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    Insulin Like Growth Factor-I and IGF-Binding Protein-3 Levels in A Healthy Adult Turkish Population
    (Ortadogu Ad Pres & Publ Co, 2011) Karakoc, Mehmet Ayhan; Ozkan, Secil; Ayvaz, Goksun; Toruner, Fusun; Yilmaz, Murat; Kan, Erdal; Arslan, Metin
    Objective: Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) levels are important markers in diagnosis of growth hormone (GH) related disorders. The normal levels of IGF-I and IGFBP-3 vary among different ethnic groups, and using the references derived from different populations may sometimes be misleading during diagnosis, treatment and follow-up. We examined the levels of IGF-I and IGFBP-3 in healthy adult Turkish population. Material and Methods: Eight hundred and thirty-three subjects (512 females, 321 males) were enrolled in the study. Serum IGF-I and IGFBP-3 levels were measured by immunoradiometric assay in all participants. The study population was divided into age groups (18-20, 21-23, 24-25, 26-30, 31-40, 41-50, >50 years of age) and gender groups (females and males separately in the population <= 30 years of age, combined in age groups over 30 years of age) according to the references defined by the kit manufacturer and the results were compared to the reference values provided by the manufacturer that represents a reference population. Results: Serum IGF-I levels were statistically higher than the reference levels in all age groups of women s 30 years of age (p<0.05). In men, IGF-I levels were significantly higher (p<0.05) only in 26-30 years age group. In gender-combined groups over 30 years of age, IGF-I levels were statistically higher than the reference levels (p<0.05). Serum IGFBP-3 levels were significantly lower than the reference values in 24-25 years age group in both genders and in 18-20 years of age in males (p<0.05). Serum IGFBP-3 levels were significantly higher in 26-30 years age group in males and in all gender-combined groups >30 years of age (p<0.05). Conclusion: Serum IGF-I concentrations of our study population are generally higher than the reference values of the commercial kit. Centers dealing with GH disorders might benefit from defining their own population's normal values for IGF-I and IGFBP-3 to overcome possible diagnostic and follow-up pitfalls.