19 results on '"Bayram, Engin"'
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2. Various extracts of the brown seaweed Cystoseira barbata with different compositions exert biostimulant effects on seedling growth of wheat.
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Mutlu‐Durak, Hande, Arikan‐Algul, Yagmur, Bayram, Engin, Haznedaroglu, Berat Z., Kutman, Umit Baris, and Kutman, Bahar Yildiz
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DURUM wheat ,SUSTAINABILITY ,SUSTAINABLE agriculture ,MARINE algae ,SEED treatment - Abstract
Worldwide, where the demand for novel and greener solutions for sustainable agricultural production is increasing, the use of eco‐friendly products such as seaweed‐derived biostimulants as pre‐sowing treatment represent a promising and important approach for the future. Cystoseira barbata, a brown seaweed species abundant in the Mediterranean Region, was collected from the Marmara Sea and subjected to water, alkali, and acidic extractions, and the biostimulant activity of these extracts was tested on wheat (Triticum durum cv. Saricanak‐98) using different rates through application to the seeds or germination medium (substrate) applications. The different extracts were characterized by mineral, total phenolic, free amino acid, mannitol, polysaccharide, antioxidant concentrations and hormone‐like activity. The effects of the extracts on growth parameters, root morphology, esterase activity, and mineral nutrient concentrations of wheat seedlings were investigated. Our results suggest that the substrate application was more effective in enhancing the seedling performance compared to the seed treatment. High rates of seaweed extracts applied to substrates increased the shoot length and fresh weight of wheat seedlings by up to 20 and 25%, respectively. The substrate applications enhanced the root fresh weights of wheat seedlings by up to 25% when compared to control plants. Among the biostimulant extract applications, the water extract at the highest rate yielded the most promising results in terms of the measured parameters. Cystoseira barbata extracts with different compositions can be used as effective biostimulants to boost seedling growth. The local seaweed biomass affected by mucilage problems, has great potential as a bioeconomy resource and can contribute to sustainable practices for agriculture. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Purification of Fab and Fc using papain immobilized cryogel bioreactor separator system
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Armutcu, Canan, Çorman, Mehmet Emin, Bayram, Engin, and Uzun, Lokman
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- 2020
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4. Cholesterol biogenesis is a PTEN‐dependent actionable node for the treatment of endocrine therapy‐refractory cancers
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Kaysudu, Irmak, primary, Gungul, Taha Bugra, additional, Atici, Sena, additional, Yilmaz, Sevval, additional, Bayram, Engin, additional, Guven, Gozde, additional, Cizmecioglu, Nihal Terzi, additional, Sahin, Ozgur, additional, Yesiloz, Gurkan, additional, Haznedaroglu, Berat Zeki, additional, and Cizmecioglu, Onur, additional
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- 2023
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5. Multiclonal plastic antibodies for selective aflatoxin extraction from food samples
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Bayram, Engin, Yılmaz, Erkut, Uzun, Lokman, Say, Rıdvan, and Denizli, Adil
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- 2017
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6. Advanced Methods for Natural Products Discovery: Bioactivity Screening, Dereplication, Metabolomics Profiling, Genomic Sequencing, Databases and Informatic Tools, and Structure Elucidation
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Gaudêncio, Susana P., primary, Bayram, Engin, additional, Lukić Bilela, Lada, additional, Cueto, Mercedes, additional, Díaz-Marrero, Ana R., additional, Haznedaroglu, Berat Z., additional, Jimenez, Carlos, additional, Mandalakis, Manolis, additional, Pereira, Florbela, additional, Reyes, Fernando, additional, and Tasdemir, Deniz, additional
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- 2023
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7. Advanced Methods for Natural Products Discovery: Bioactivity Screening, Dereplication, Metabolomics Profiling, Genomic Sequencing, Databases and Informatic Tools, and Structure Elucidation
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Gaudêncio, Susana P., Bayram, Engin, Lukić Bilela, Lada, Cueto, Mercedes, Díaz-Marrero, Ana R., Haznedaroglu, Berat Z., Jimenez, Carlos, Mandalakis, Manolis, Pereira, Florbela, Reyes, Fernando, Tasdemir, Deniz, Gaudêncio, Susana P., Bayram, Engin, Lukić Bilela, Lada, Cueto, Mercedes, Díaz-Marrero, Ana R., Haznedaroglu, Berat Z., Jimenez, Carlos, Mandalakis, Manolis, Pereira, Florbela, Reyes, Fernando, and Tasdemir, Deniz
- Abstract
Natural Products (NP) are essential for the discovery of novel drugs and products for numerous biotechnological applications. The NP discovery process is expensive and time-consuming, having as major hurdles dereplication (early identification of known compounds) and structure elucidation, particularly the determination of the absolute configuration of metabolites with stereogenic centers. This review comprehensively focuses on recent technological and instrumental advances, highlighting the development of methods that alleviate these obstacles, paving the way for accelerating NP discovery towards biotechnological applications. Herein, we emphasize the most innovative high-throughput tools and methods for advancing bioactivity screening, NP chemical analysis, dereplication, metabolite profiling, metabolomics, genome sequencing and/or genomics approaches, databases, bioinformatics, chemoinformatics, and three-dimensional NP structure elucidation.
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- 2023
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8. Advanced Methods for Natural Products Discovery: Bioactivity Screening, Dereplication, Metabolomics Profiling, Genomic Sequencing, Databases and Informatic Tools, and Structure Elucidation
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European Cooperation in Science and Technology, Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Consejo Superior de Investigaciones Científicas (España), Gaudêncio, Susana P., Bayram, Engin, Bilela, Lada Lukic, Cueto, Mercedes, Díaz Marrero, Ana Raquel, Haznedaroglu, Berat Z., Jimenez, Carlos, Mandalakis, Manolis, Pereira, Florbela, Reyes, Fernando, Tasdemir, Deniz, European Cooperation in Science and Technology, Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Consejo Superior de Investigaciones Científicas (España), Gaudêncio, Susana P., Bayram, Engin, Bilela, Lada Lukic, Cueto, Mercedes, Díaz Marrero, Ana Raquel, Haznedaroglu, Berat Z., Jimenez, Carlos, Mandalakis, Manolis, Pereira, Florbela, Reyes, Fernando, and Tasdemir, Deniz
- Abstract
Natural Products (NP) are essential for the discovery of novel drugs and products for numerous biotechnological applications. The NP discovery process is expensive and time-consuming, having as major hurdles dereplication (early identification of known compounds) and structure elucidation, particularly the determination of the absolute configuration of metabolites with stereogenic centers. This review comprehensively focuses on recent technological and instrumental advances, highlighting the development of methods that alleviate these obstacles, paving the way for accelerating NP discovery towards biotechnological applications. Herein, we emphasize the most innovative high-throughput tools and methods for advancing bioactivity screening, NP chemical analysis, dereplication, metabolite profiling, metabolomics, genome sequencing and/or genomics approaches, databases, bioinformatics, chemoinformatics, and three-dimensional NP structure elucidation.
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- 2023
9. Advanced Methods for Natural Products Discovery
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Gaudêncio, Susana P., Bayram, Engin, Lukić Bilela, Lada, Cueto, Mercedes, Díaz-Marrero, Ana R., Haznedaroglu, Berat Z., Jimenez, Carlos, Mandalakis, Manolis, Pereira, Florbela, Reyes, Fernando, Tasdemir, Deniz, UCIBIO - Applied Molecular Biosciences Unit, DQ - Departamento de Química, and LAQV@REQUIMTE
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molecular networking ,natural products databases ,natural products ,computer assisted structure elucidation (CASE) ,Pharmaceutical Science ,dereplication ,blue biotechnology ,high-throughput screening (HTS) ,relative and absolute configuration determination in structure elucidation ,Drug Discovery ,Global Natural Product Social Molecular Networking (GNPS) ,high throughput next-generation sequencing (HT/NGS) ,informatic chemometrics ,mode of action (MoA) ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) - Abstract
Funding Information: This publication is based upon work from COST Action CA18238 (Ocean4Biotech), funded by the European Cooperation in Science and Technology (COST) Program in the period 2019–2023. SPG: This work is financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB. LLB: The publication is part of a project that has received funding from the Erasmus + Project No. ECOBIAS_609967-EPP-1-2019-1-RS-EPPKA2-CBHE-JP; GA.2019-1991/001-001. Development of master curricula in ecological monitoring and aquatic bioassessment for Western Balkans HEIs/ECOBIAS. CJ: This work was supported by grants PID2021-122732OB-C22 from MCIN/AEI/10.13039/501100011033/FEDER “A way to make Europe” (AEI, Spanish State Agency for Research and FEDER Programme from the European Union) and RTI2018-093634-B-C22 from the State Agency for Research (AEI) of Spain, co-funded by the FEDER Programme from the European Union, and BLUEBIOLAB (0474_BLUEBIOLAB_1_E), Programme INTERREG V A of Spain-Portugal (POCTEP). FP: This work is financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., for an Assistant Research Position (CEECIND/01649/2021). MC: INTERREG-MAC2/1.1b/279 (AHIDAGRO) and the Ministerio de Ciencia e Innovación (Spain) (grant PID2020-115979RR-C32). ARDM is supported with funds from Proyecto Intramural Especial CSIC [Ref. 202280I032]. Publisher Copyright: © 2023 by the authors. Natural Products (NP) are essential for the discovery of novel drugs and products for numerous biotechnological applications. The NP discovery process is expensive and time-consuming, having as major hurdles dereplication (early identification of known compounds) and structure elucidation, particularly the determination of the absolute configuration of metabolites with stereogenic centers. This review comprehensively focuses on recent technological and instrumental advances, highlighting the development of methods that alleviate these obstacles, paving the way for accelerating NP discovery towards biotechnological applications. Herein, we emphasize the most innovative high-throughput tools and methods for advancing bioactivity screening, NP chemical analysis, dereplication, metabolite profiling, metabolomics, genome sequencing and/or genomics approaches, databases, bioinformatics, chemoinformatics, and three-dimensional NP structure elucidation. publishersversion published
- Published
- 2023
10. Rapid Analysis of Polycyclic Aromatic Hydrocarbons in Water Samples Using an Automated On-line Two-Dimensional Liquid Chromatography
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Armutcu, Canan, Özgür, Erdoğan, Karasu, Tunca, Bayram, Engin, Uzun, Lokman, and Çorman, Mehmet Emin
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- 2019
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11. Aspartic acid incorporated monolithic columns for affinity glycoprotein purification
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Armutcu, Canan, Bereli, Nilay, Bayram, Engin, Uzun, Lokman, Say, Rıdvan, and Denizli, Adil
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- 2014
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12. Selective removal of 17β-estradiol with molecularly imprinted particle-embedded cryogel systems
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Koç, İlker, Baydemir, Gözde, Bayram, Engin, Yavuz, Handan, and Denizli, Adil
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- 2011
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13. Covid-19 Pandemi Sürecinde Ortaokul Öğrencilerinin Uzaktan Eğitimle Gerçekleştirilen Türkçe Dersine Yönelik Algıları
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BAYRAM, Engin, primary, BIYIK, Zeynep, additional, and GÖLBAŞI, Mehmet, additional
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- 2021
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14. Covid-19 pandemi sürecinde ortaokul öğrencilerinin uzaktan eğitimle gerçekleştirilen türkçe dersine yönelik algıları
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Bayram, Engin, Bıyık, Zeynep, and Gölbaşı, Mehmet
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Motivation ,Dil Becerileri ,Türkçe Eğitimi ,Uzaktan Eğitim ,Language Skills ,Covid-19 ,Turkish Education ,Motivasyon ,Distance Education - Abstract
Hazırlıksız yakalanılan Covid-19 salgını bütün dünyayı hem sosyal hem de akademik anlamda etkilemiştir. İçinde bulunulan süreçte öğrenme kaybı yaşanmaması için dersler uzaktan eğitim şeklinde yürütülmüştür. Bu doğrultuda çalışma, Covid-19 pandemi sürecinde öğrencilerin uzaktan eğitimle gerçekleştirilen Türkçe dersine yönelik algılarını belirlemeyi amaçlamaktadır. Çalışmanın hedef kitlesini ortaokul öğrencileri oluşturmaktadır. Çalışmada veri toplama aracı olarak görüşmeden yararlanılmış, yarı yapılandırılmış görüşme formu kullanılmıştır. Araştırmanın verileri olgubilime uygun olarak toplanmış, verilerin analizi sürecinde içerik analizinden yararlanılmıştır. Sonuç bölümünde katılımcıların görüşlerinden hareketle uzaktan eğitimle gerçekleştirilen Türkçe dersine yönelik algılar farklı değişkenler bakımından değerlendirilmiş; sürecin daha verimli geçmesi için çeşitli önerilerde bulunulmuştur. The Covid-19 epidemic, which caught us unprepared, has affected the whole world both socially and academically. In order not to experience loss of learning in the current process, the courses are delivered via distance education. In this direction, the study aims to determine the students’ perceptions towards the Turkish course conducted with distance education during the Covid-19 pandemic. The target population of the study is secondary school students. Interview was conducted as a data collection tool, and a semi-structured interview form was used. The data of the research were collected in accordance with the phenomenology, and content analysis was employed for data analysis. In the conclusion part, based on the participants’ opinions, the perceptions of the Turkish course delivered via distance education were evaluated in terms of different variables; various suggestions have been made to manage the process more efficiently.
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- 2021
15. Molecularly imprinted cryogel for l-glutamic acid separation
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Aydoğan, Cemil, Andaç, Muge, Bayram, Engin, Say, Rdvan, and Denizli, Adil
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- 2012
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16. Molecular imprinted solid phase extraction columns and their application to pre-concentration of aflatoxins
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Bayram, Engin, Denizli, Adil, and Biyokimya Anabilim Dalı
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Chemistry ,HPLC method ,Aflatoxins ,Affinity chromatography ,Kimya - Abstract
Tez kapsamında; aflatoksin baskılanmış kompozit kriyojellerin sentez, karakterizasyon ve seçici ön-deriştirme (özütleme) çalışmaları gerçekleştirilmiştir. Monomer olarak N-Metakriloil-L-triptofan metil ester (MATrp) seçilmiştir. Öncelikli olarak bu monomerin sentezi gerçekleştirilmiş ve elde edilen ürün, NMR ve FTIR yöntemleri ile karakterize edilmiştir. Sentezlenen monomer ve aflatoksinler kompleksleştirilmiş ve kompleksleşme, spektroflorimetrik yöntem ile karakterize edilmiştir. Bu işlemin ardından aflatoksin baskılanmış poli(2-Hidroksietilmetakrilat- N-Metakriloil-L-triptofan metil ester) monolitik polimerler, yığın polimerizasyonu yöntemi ile sentezlenmiştir. Elde edilen monolitik polimerler, öğütülerek eş boyutlu partiküller elde edilmiş ve partikül boyutları, zeta parçacık boyut ölçümü ile karakterize edilmiştir. Aflatoksin baskılanmış poli-[N-(2-Hidroksietil) metakrilamit] kompozit kriyojeli ise aflatoksin baskılanmış partiküllerin varlığında, 2-Hidroksietilmetakrilat (HEMA) ve Metilen bisakrilamidin (MBAAm), -12ºC?da 24 saatlik polimerizasyonu sonucu elde edilmiş, SEM ve FTIR yöntemleri ile karakterize edilmiştir. Hazırlanan kompozitler, sulu çözeltilerden aflatoksin ön-deriştirme işlemlerinde kullanılmış ve ön-deriştirme koşulları optimize edilmiştir. Optimizasyon çalışmaları kapsamında; aflatoksin derişimi, akış hızı, pH, sıcaklık ve partikül miktarının etkileri HPLC yöntemi kullanılarak incelenmiştir. Kompozitin aflatoksin türlerine göre adsorpsiyon kapasiteleri sırasıyla aflatoksin B1 için 194.8 ng/g; aflatoksin B2 için 164.1 ng/g; aflatoksin G1 için 169.4 ng/g ve aflatoksin G2 için 154.9 ng/g olarak bulunmuştur. Kompozitlerin adsorpsiyon kapasiteleri, akış hızı ile ters orantılı iken; pH ve sıcaklıkla doğru orantılı olarak değişmektedir. Kompozit kriyojellerin diğer mikotoksinlere karşı seçicilikleri, okratosin A (OTA) ve aflatoksin M1 (AFT M1) varlığında gerçekleştirilen özütleme çalışmaları ile belirlenmiştir. Adı geçen çalışmalarda, ölçüm tekniği olarak LC-MS/MS kullanılmıştır. Ön-deriştirme koşullarının optimizasyonunun ardından gerçek numunelerde (fındık, fıstık, kuru incir ve pulbiber) aflatoksin özütleme uygulamaları gerçekleştirilmiştir. Anahtar Kelimeler: Kompozit Kriyojeller, Moleküler Baskılama, Mikotoksinler, Aflatoksin Analizi. In this study, the synthesis and characterization of aflatoxin imprinted composite cryogels prepared, and selective aflatoxin pre-concentration studies were performed. N-Methacryloyl-(l)-tryptophanemethylester (MATrp) was chosen as the complexing monomer. In the first step, functional monomer MATrp was synthesized, and resulting compound was characterized by NMR and FTIR measurements. After that, aflatoxins was complexed with MATrp, and the complex was charcterized by fluorometric measurements. Then aflatoxin-imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-(l)-tryptophane methylester) [MIP] polymers were synthesized by bulk polymerization. The resulting polymers were grinded to obtain similar-sized particles and they characterized by zeta-particle size analyser. Aflatoxin imprinted poly[2-hydroxyethylmethacrylamide] composite cryogels were synthesized via polymerization of 2-Hydroxyethyl methacrylate (HEMA) and N,N'-Methylenebisacrylamide (MBAAm) in presence of aflatoxin imprinted micro particles, at -12°C. The completion of the polymerization reaction requires 24 hours. Resulting composites were characterized by Scanning Electron Microscopy (SEM) and FTIR measurements. Aflatoxin imprinted composite cryogels were used to extract aflatoxins from aqueous solutions in order to optimize the extraction conditions. In this context, the effective factors such as aflatoxin concentration, flow rate, pH, temperature and amount of the particle in composite cryogel structure were evaluated via HPLC. The adsorption capacities of the composite cryogels according to aflatoxin species were determined as 194.8 ng/g for aflatoxin B1, 164.1 ng/g for aflatoxin B2, 169.4 ng/g for aflatoxin G1 and 154.9 ng/g for aflatoxin G2, respectively. The adsorption capacities of the composite cryogels were directly proportional to the changes in pH and temperature while that were contrary to the changes in flow rate. Ochratoxin A (OTA) and aflatoxin M1 (AFT M1) used in the competative extrction studies for selectivity. LC-MS/MS used as an analytical tool for the measurement during the selectivity studies. When the adsorption conditions completed the composite cryogels applied to the real samples (nut, peanut, red pepper and dried fig).Keywords: Composite Cryogels, Molecular Imprinting, Mycotoxins, Aflatoxin Analysis 125
- Published
- 2013
17. Removal of phenols from waste waters via dye affinity sorption
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Bayram, Engin, Bektaş, F. Sema, and Kimya Anabilim Dalı
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Chemistry ,Dye affinity ,Kimya ,Environmental pollution ,Chlorophenols - Abstract
Poli(akrilamid-allil glisidil eter) [poli(AAm-AGE)] kriyojeli, monomerlerin bir cam kolon içerisinde donmuş sulu çözeltilerinde ilerleyen yığın polimerizasyon (kriyo-polimerizasyon) işlemi ile hazırlanmıştır. Eritme işleminin ardından 10-100 ?m boyutlarında birbirlerine polimerik matriks boyunca kesintisiz olarak bağlı gözeneklere sahip monolitik kriyojel elde edilmiştir. Poli(AAm-AGE) kriyojelne Cibacron Blue F3GA immobilizasyonu, epoksi grupları üzerinden kovalent bağlanma aracılığıyla gerçekleştirillmiştir. Poli(AAm-AGE) kriyojeli, şişme testleri, FTIR, taramalı elektron mikroskobu (SEM), elemental analiz yöntemleri ile karakterize edilmiştir. Poli(AAm-AGE) monolitik kriojelinin denge şişme oranı, 6.84 g H2O/g kriyojel olarak bulunmuştur. 68.9 ?mol Cibacron Blue F3GA/g içeren poli(AAm-AGE) kriyojeli, fenol ve klorofenollerin sulu çözeltilerden (fenol, m-klorofenol, p-klorofenol, 2,4,6-triklorofenol) adsorpsiyon/desorpsiyon çalışmaları için kullanılmıştır. Fenol ve Klorofenollerin Cibacron Blue F3GA içeren poli(AAm-AGE) kriyojeli üzerine maksimum adsorpsiyonu, fenol için 128.5 ?mol/g, 2,4,6-triklorofenol için 144.3 ?mol/g, p-klorofenol için 155.8 ?mol/g ve m-klorofenol için 164.7 ?mol/g olarak bulunmuştur. Bu değerler ışığında afinite sıralaması şu şekilde oluşturulmuştur: m-klorofenol > p-klorofenol > 2,4,6-triklorofenol > fenol. fenollerin adsorpsiyonu pH değerinin artması ile azalmaktadır. Fenollerin desorpsiyonu methanol çözeltisi (%30 v/v) kullanılarak sağlanmıştır. Sulu fazdaki fenollerin cosantrasyonu HPLC (High Performance Liquid Chromatography) yöntemi ile belirlenmiştir. Cibacron Blue F3GA immobilize edilmiş kriyojeller, adsorpsiyon kapasitelerinde dikkate değer bir düşüş olmadan ondan fazla adsorpsiyon/desorpsiyon çalışmasına uygundur.Anahtar kelimeler: Boya-afinite adsorpsiyonu, Kriyojeller, Klorofenoller, Çevre kirliliği Poly(acrylamide-allyl glycidyl ether) [poly(AAm-AGE)] cryogel was prepared by bulk polymerization which proceeds in an aqueous solution of monomers frozen inside a glass column (cryo-polymerization). After thawing, the monolithic cryogel contains a continuous polymeric matrix having interconnected pores of 10-100 ?m size. Cibacron Blue F3GA was immobilized by covalent binding onto poly(AAm-AGE) cryogel via epoxy groups. Poly(AAm-AGE) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy (SEM) and elemental analysis. The equilibrium swelling degree of the poly(AAm-AGE) monolithic cryogel was 6.84 g H2O/g cryogel. Poly(AAm-AGE) cryogel containing 68.9 ?mol Cibacron Blue F3GA/g were used in the adsorption/desorption of phenol and chlorophenols (i.e., phenol, m-chlorophenol, p-chlorophenol and 2,4,6-trichlorophenol) from aqueous solutions. The maximum adsorptions of phenols onto the Cibacron Blue carrying cryogels were 128.5 ?mol/g for phenol, 144.3 ?mol/g for 2,4,6-trichlorophenol, 155.8 ?mol/g for p-chlorophenol and 164.7 ?mol/g for m-chlorophenol. The affinity order was as follows: m-chlorophenol > p-chlorophenol > 2,4,6-trichlorophenol > phenol. The adsorption of chlorophenols decreased with increasing pH. Desorption of chlorophenols was achieved using methanol solution (30%, v/v). The concantration of phenols in the aqueous phase was determined by HPLC(High Performance Liquid Chromatography). The Cibacron Blue F3GA-carrying cryogels are suitable for repeated use for more than ten cycles without noticeable loss of adsorption capacity.Keywords: Dye-affinity adsorption, Cryogels, Chlorophenols, Environmental pollution 74
- Published
- 2007
18. Trametes versicolor laccase immobilized poly(glycidyl methacrylate) based cryogels for phenol degradation from aqueous media.
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Doğan, Tuğba, Bayram, Engin, Uzun, Lokman, Şenel, Serap, and Denizli, Adil
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TRAMETES versicolor ,LACCASE ,PHENOL ,SEWAGE ,FOURIER transform infrared spectroscopy - Abstract
ABSTRACT This study aims removal of phenols in wastewater by enzymatic oxidation method. In this study, Trametes versicolor laccase was covalently immobilized onto a cryogel matrix by the nucleophilic attack of amino groups of laccase to epoxy groups of matrix. Glycidyl methacrylate was chosen as functional monomer to prepare poly(2-hydroxyethyl methacrylate- co-glycidyl methacrylate) [p(HEMA- co-GMA)] cryogels. The enzyme immobilized matrix was characterized by FTIR, SEM, and swelling tests. The effect of pH, reaction time, temperature, substrate concentration, enzyme concentration, and storage period on immobilized enzyme activity was determined and compared with those of free enzyme. The model substrate was 2,2′-azino- bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS). Lineweaver-Burk plots were used to calculate K
m and Vm values. Km values were 165.1 and 156.0 µ M while Vm values were 55.2 µ M min−1 and 1.57 µ M min−1 for free and immobilized laccase, respectively. Immobilized enzyme was determined to retain 82.5% and 72.0% of the original activity, respectively, after 6 consecutive use and storage period of 4 weeks. The free enzyme retained only 24.0% of its original activity following the same storage period. Lastly, decomposition products resulting from enzymatic oxidation of a model phenolic compound (3,5-dinitrosalicylic acid) in aqueous solution were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41981. [ABSTRACT FROM AUTHOR]- Published
- 2015
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19. Poly acrylamide-allyl glycidyl ether Cryogel as a Novel Stationary Phase for Chlorophenol Adsorption
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BAYRAM, Engin, UZUN, Lokman, TÜRKMEN, Deniz, YILMAZ, Erkut, GALAEV, Igor Yu, DENİZLİ, Adil, and BEKTAŞ, Sema
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Dye-affinity adsorption,cryogels,chlorophenols,environmental pollution - Abstract
Poly acrylamide-allyl glycidyl ether [poly AAm-AGE ] cryogel was prepared by bulk polymerization which proceedsin an aqueous solution of monomers frozen inside a glass column cryo-polymerization . After thawing, the monolithiccryogel contains a continuous polymeric matrix having interconnected pores of 10-100 µm size. Cibacron Blue F3GAwas immobilized by covalent binding onto poly AAm-AGE cryogel via epoxy groups. Poly AAm-AGE cryogel wascharacterized by swelling studies, FTIR, scanning electron microscopy SEM and elemental analysis. The equilibriumswelling degree of the poly AAm-AGE monolithic cryogel was 6.84 g HO/g cryogel. Poly AAm-AGE cryogelcontaining 68.9 µmol Cibacron Blue F3GA/g were used in the adsorption/desorption of chlorophenols i.e., phenol,m-chlorophenol, p-chlorophenol and 2,4,6-trichlorophenol from aqueous solutions. The maximum adsorptions ofchlorophenols onto the Cibacron Blue carrying cryogels were 128.5 µmol/g for phenol, 144.3 µmol/g for 2,4,6trichlorophenol, 155.8 µmol/g for p-chlorophenol and 164.7 µmol/g for m-chlorophenol. The affinity order was asfollows: m-chlorophenol > p-chlorophenol > 2,4,6-trichlorophenol > phenol. The adsorption of chlorophenols decreasedwith increasing pH. Desorption of chlorophenols was achieved using methanol solution 30%, v/v . The cibacron BlueF3GA-carrying cryogels are suitable for repeated use for more than ten cycles without noticeable loss of adsorptioncapacity
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