Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(46)
- Kulakaç, Nurşen(21)
- Aydin, Aydanur(16)
- Demir, Selim(16)
- Tuncer, Metin(16)
- Topal, Fevzi(15)
- Turan, Ibrahim(15)
- Yilmaz, Coskun(14)
- Bayrakdaroglu, Serdar(12)
- Koçak, Tevfik(11)
- Aliyazicioglu, Yuksel(10)
- Gulcin, Ilhami(10)
- Ozturk, Samet(10)
- Topal, Meryem(10)
- Ceylan, Halil Ibrahim(9)
- Ceylan, Levent(9)
- Kilinc, Kagan(9)
- Mentese, Ahmet(9)
- Ozdes, Duygu(9)
- Tuncer, Gülsüm Zekiye(9)
- Duran, Celal(8)
- Emirza, Elif Güzide(8)
- Yaman, Serap Ozer(8)
- Yılmaz, Coşkun(8)
- Baltacı, Cemalettin(7)
- Demirağ, Hatice(7)
- Hintistan, Sevilay(7)
- Kaya, Feridun(7)
- Küçük, Murat(7)
- Ürkek, Bayram(7)
- Şengül, Mustafa(7)
- Bayrakdaroğlu, Serdar(6)
- Deger, Orhan(6)
- Genc, Berna(6)
- Gül, Abdulkadir(6)
- Gülçin, Ilhami(6)
- Günen, Mehmet Akif(6)
- Gürsoy, Ayla(6)
- Kurnaz, Muammer(6)
- Supuran, Claudiu T.(6)
Yayınlar
- MakaleYalnız künye2017Effectiveness of Black Mulberry Molasses in Prevention of Radiotherapy-Induced Oral Mucositis: A Randomized Controlled Study in Head and Neck Cancer Patients
Doǧan, Melike Demir; Can, Gulbeyaz; Meral, Rasim
Objectives: Radiation-induced oral mucositis is one of the problems experienced by 70%-80% of patients receiving radiation therapy (RT). This randomized controlled trial assessed the effectiveness of black mulberry molasses in the prevention of oral mucositis in head and neck cancer patients receiving RT. Interventions and Outcome measures: Eighty head and neck cancer patients scheduled to undergo RT to the oropharyngeal mucosa were randomly assigned to receive RT (42) or RT plus mulberry molasses (38). The research data were collected with a Patient Description Form, Common Terminology Criteria for Adverse Events, version 4.0, an Oral Assessment Guide, and the University of Washington Quality of Life Assessment Questionnaire. Results: The incidence and severity of oral mucositis were lower in the black mulberry molasses group. However, black mulberry molasses usage was an only independent and significant factor in prevention of mucositis [HR 0.63 (%95 GI 0.40-0.98)]. There were no differences between the quality of life scores of experimental and control groups. Conclusions: This randomized controlled study showed that black mulberry molasses usage is an effective intervention in the prevention of the radiation-induced mucositis of head and neck cancer patients. However, to confirm these results, further studies are needed.
- MakaleYalnız künye2017Lasting hepatotoxic effects of prenatal mobile phone exposure
Yilmaz, A.; Tumkaya, L.; Akyildiz, K.; Kalkan, Y.; Bodur, A.F.; Sargin, F.; Efe, H.; Uydu, H.A.; Yazici, Z.A.
Objective: In this study, the livers of rats born to mothers exposed to electromagnetic field (EMF) were examined 60 days postpartum for biochemical and histopathological changes. Methods: Pregnant rats were exposed to radiation (900 MHz EMF, 24 h/day for 20 days) using a digital signal generator by placing the device centrally under the cage, which formed the study (EMF) group, while untreated matching rats served as controls. Livers and blood were obtained from litters (seven males and seven females) of both groups 60 days after birth, which were used for biochemical and histopathological analyses. Results: There was a significant increase in the levels of malondialdehyde (MDA) (p <0.05) that was accompanied by a significant fall in glutathione (GSH) (p <0.01) in the liver. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased (p <0.05). Histopathologically, the liver sections of the EMF group showed intense degeneration in hepatocytes with cytoplasmic eosinophilic structures, pyknotic nuclei and fibrosis. Conclusion: We demonstrate that the intrauterin harmful effects of EMF on the livers of rats persist into adulthood.
- MakaleAçık Erişim2017Deterministic stability and random behavior of a Hepatitis C model
Merdan, Mehmet; Bekiryazici, Zafer; Kesemen, Tulay; Khaniyev, Tahir
The deterministic stability of a model of Hepatitis C which includes a term defining the effect of immune system is studied on both local and global scales. Random effect is added to the model to investigate the random behavior of the model. The numerical characteristics such as the expectation, variance and confidence interval are calculated for random effects with two different distributions from the results of numerical simulations. In addition, the compliance of the random behavior of the model and the deterministic stability results is examined.
- MakaleAçık Erişim2017Novel eugenol derivatives: Potent acetylcholinesterase and carbonic anhydrase inhibitors
Topal, Fevzi; Gulcin, Ilhami; Dastan, Arif; Guney, Murat
Eugenol was used as starting material to obtain some phenolic compounds. The synthesis of these phenolic compounds was performed in a two-step procedure. The structures of the formed products (novel eugenol derivatives 1–6) have been determined on the basis of NMR spectroscopy and other spectroscopic methods. The compounds were tested in terms of carbonic anhydrase (CA) inhibition potency. Carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes, which catalyse the reaction between carbon dioxide (CO2) and water (H2O), to generate bicarbonate (HCO3−) and protons (H+). CO2, HCO3− and H+ are essential molecules and ions for many important physiologic processes occurring in all living organisms. Acetylcholinesterase (AChE, E.C.3.1.1.7) is found in high concentrations in the red blood cells and brain. Novel eugenol derivatives (1–6) were tested for the inhibition of two cytosolic CA isoforms I, and II (hCA I, and II) and AChE. These compounds demonstrated effective inhibitory profiles with Ki values in ranging of 113.48-738.69 nM against hCA I, 92.35-530.81 nM against hCA II, and 90.10-379.57 nM against AChE, respectively. On the other hand, acetazolamide clinically used as CA inhibitor, shoed Ki value of 594.11 nM against hCA I, and 120.68 nM against hCA II, respectively. Also, AChE was inhibited by tacrine as an AChE inhibitor at the 71.18 nM level.
- MakaleYalnız künye2017Radioactivity measurements and risk assessments of spa waters in some areas in Turkey
Duran, Selcen Uzun; Kucukomeroglu, Belgin; Damla, Nevzat; Taskin, Halim; Celik, Necati; Cevik, Uğur; Ersoy, Hakan
The current study presents the results of the activity of radionuclides in spa waters, and evaluates their radiological influences on the population consuming these waters in the Central and Eastern Black Sea regions of Turkey. Since these waters are used for therapy and consumption purposes unconsciously, their radiological impact on the people was computed by taking into consideration the annual intake through ingestion of 226Ra, 232Th, 40K, 137Cs and 222Rn. The mean activities were estimated to be 11.35 for gross alpha, 6.23 for gross beta, 2.96 for 226Ra, 0.42 for 232Th, 0.069 for 137Cs, 0.19 for 40K, and 267 Bq L–1 for 222Rn, respectively. The estimated effective doses from spa water were found to be 49.77 µSv a–1 (226Ra), 5.95 µSv a–1 (232Th), 0.07 µSv a–1 (137Cs), 0.83 µSv a–1 (40K) and 56.03 µSv a–1 (222Rn). These values were evaluated and compared with related verified values from literature. Also, physico-chemical characterizations of spa water samples considered in the current study were investigated. This study would be useful for consumers and official authorities for the assessment of radiation exposure risk due to usage of the considered spa waters.
- MakaleAçık Erişim2017Prevalence and comparing of some microbiological properties, somatic cell count and antibiotic residue of organic and conventional raw milk produced in Turkey
Ürkek, Bayram; Şengül, Mustafa; Erkaya, Tuba; Aksakal, Vecihi
The aim of this study was to investigate the effects of production systems and milk collection periods on the somatic cell count (SCC), some microbiological properties, total aerobic mesophilic bacteria (TAMB), coliform, Staphylococcus aureus (S. aureus), yeast and mould) and antibiotic residue of milk; in Turkey. Milk samples were collected from 9 conventional farms and 9 organic farms during one year time, at six different months (December 2013 to October 2014), and all farms were selected from the same geographical locations. All organically managed farms had organic production certificates given by the Republic of Turkey Ministry of Food, Agriculture and Livestock. The count of TAMB, coliform, and coagulase positive S. aureus were affected by production systems at the level of p<0.01; yeast and mold, and somatic cell count (SCC) were affected at the level of p<0.05. But, differences according to months were statistically significant only on TAMB (p<0.01) and coliform (p<0.05) counts. The general means of TAMB, coliform and yeast and mould counts of the organic milk (OM) were significantly lower (p<0.05), while the general means of SCC and coagulase positive S. aureus count of the OM was significantly higher (p<0.05) compared to conventional milk (CM). Antibiotic residue was determined in one of the CM sample and in two of the OM samples. Our study is the first research that compared conventional and organic milk in Turkey. This study indicated that the microbiological quality of OM was the higher in terms of TAMB, coliform and yeast and mould, whereas was the lower in relation to SCC and coagulase positive S. aureus counts. But, the quality of both milk types should be improved.
- MakaleAçık Erişim2017Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction
Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin
In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L) Cl2]·2H2O (1), [Co(L)Cl2(H2O)2] (2) and [Ni(L)Cl2(H2O)2] (3), having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1. The esterification of butanol gave butyl acetate with 100% selectivity.
- MakaleAçık Erişim2017Antiproliferative and apoptotic effect of Morus nigra extract on human prostate cancer cells
Turan, Ibrahim; Demir, Selim; Kilinc, Kagan; Burnaz, Nesibe Arslan; Yaman, Serap Ozer; Akbulut, Kubra; Mentese, Ahmet; Aliyazicioglu, Yuksel; Deger, Orhan
Background: Morus nigra L. belongs to the family Moraceae and is frequently used in traditional medicine. Numerous studies have investigated the antiproliferative effects of various extracts of different Morus species, but studies involving the in vitro cytotoxic effect of M. nigra extract are very limited. The purpose of this study was to evaluate the phenolic composition and antioxidant activity of dimethyl sulfoxide extract of M. nigra (DEM) and to investigate, for the first time, the probable cytotoxic effect in human prostate adenocarcinoma (PC-3) cells together with the mechanism involved. Methods: Total polyphenolic contents (TPC), ferric reducing antioxidant power (FRAP) and phenolic compounds of DEM were evaluated using spectrophotometric procedures and HPLC. The cytotoxic effect of DEM on PC-3 cells was revealed using the MTT assay. Mechanisms involved in the cytotoxic effect of DEM on PC-3 cells were then investigated in terms of apoptosis, mitochondrial membrane potential and cell cycle using flow cytometry, while caspase activity was investigated using luminometric analysis. Results: TPC and FRAP values were 20.7 ± 0.3 mg gallic acid equivalents and 48.8 ± 1.6 mg trolox equivalents per g sample, respectively. Ascorbic acid and chlorogenic acid were the major phenolic compounds detected at HPLC analysis. DEM arrested the cell cycle of PC-3 cells at the G1 phase, induced apoptosis via increased caspase activity and reduced mitochondrial membrane potential. Conclusions: Our results indicate that M. nigra may be a novel candidate for the development of new natural product based therapeutic agents against prostate cancer.
- MakaleYalnız künye2017Nothing is more important than my partner's health: Turkish men's perspectives on partner's appearance after mastectomy and alopecia
Gürsoy, Ayla; Koçan, Sema; Aktuğ, Cemile
Purposes The aim of this study was to acquire a deeper understanding of male experiences on the emotional and social impact of their partners’ mastectomy and chemotherapy-induced alopecia. Methods A purposive sample of 16 males whose partners had undergone mastectomy and alopecia due to chemotherapy was chosen. The data were collected through a semi-structured interview method. Interpretative Phenomenological Analysis of tape-recorded interviews was employed. Results Two main themes emerged from the data: facing the changes and my wife and I at present. Male partners were affected differently by the change in the physical appearance of their female partners. Our study participants said it was a difficult experience to see their partners for the first time after the surgery, but they emphasized that it was more important that their partners were healthy than the fact that they did not have a breast and hair. They also said they did not know how to behave towards their partners after surgery and/or chemotherapy. Nevertheless, they felt that the disease process of their partners had strengthened their bond and had not negatively influenced their relationship with others. Conclusions The changes in the partners’ physical appearance after mastectomy and chemotherapy affected males differently in psychological, emotional and social terms. Since nurses working in this field are in contact with patients during all phases of treatment and care, it would be positive and beneficial to plan nursing interventions that give emotional support for male partners of patients with breast cancer.
- MakaleYalnız künye2017Morus Rubra Extract Induces Cell Cycle Arrest and Apoptosis in Human Colon Cancer Cells Through Endoplasmic Reticulum Stress and Telomerase
Demir, Selim; Turan, Ibrahim; Aliyazicioglu, Yuksel; Kilinc, Kagan; Yaman, Serap Ozer; Ayazoglu Demir, Elif; Arslan, Ayse; Mentese, Ahmet; Deger, Orhan
Many studies have reported cytotoxic effects of different Morus species, but there have been only limited studies on the cytotoxic effect of Morus rubra. The aims of this study were to evaluate the cytotoxic effect of dimethyl sulfoxide extract of M. rubra and to investigate, for the first time, its probable cytotoxic activity in human colon cancer (WiDr) cells, together with the mechanism involved. The cytotoxic activity of extract was determined using MTT assay. The mechanism involved in the cytotoxic effect of extract was then evaluated in terms of apoptosis, and the cell cycle using flow cytometry, mitochondrial membrane potential (MMP) was investigated using the fluorometric method, and expression levels of telomerase and C/EBP homologous protein (CHOP) were investigated using reverse-transcription PCR (RT-PCR). M. rubra extract exhibited moderate selective cytotoxicity on colon cancer cells compared with fibroblast cells. Extract induced cell cycle arrest at the G1 phase and apoptosis via reduced MMP in WiDr cells. Additionally, M. rubra extract significantly repressed telomerase and induced CHOP expressions in WiDr cells. Our results demonstrate that targeting telomerase and endoplasmic reticulum stress represents a promising strategy in colon cancer therapy, and M. rubra may have considerable potential for development as a novel natural product-based anticancer agent.
- MakaleAçık Erişim2017Analysis of transcriptional profiles of Saccharomyces cerevisiae exposed to bisphenol A
Bereketoglu, Ceyhun; Arga, Kazim Yalcin; Eraslan, Serpil; Mertoglu, Bulent
Bisphenol A (BPA), an endocrine disrupting chemical, is used as a monomer in the production of epoxy resins and polycarbonates, and as a plasticizer in polyvinyl chloride. As such, it is produced in large quantities worldwide and continuously leaches into the environment. To capture the genome reprogramming in eukaryotic cells under BPA exposure, here, we used Saccharomyces cerevisiae as model organism and analyzed the genome-wide transcriptional profiles of S. cerevisiae BY4742 in response to BPA, focusing on two exposure scenarios: (1) exposure to a low inhibition concentration (50 mg/L; resulting in <10 % inhibition in cell number) and (2) a high inhibition concentration (300 mg/L; resulting in >70 % inhibition in cell number). Based on the transcriptional profiling analyses, 81 genes were repressed and 104 genes were induced in response to 50 mg/L BPA. Meanwhile, 378 genes were downregulated and 606 genes were significantly upregulated upon exposure to 300 mg/L BPA. While similar processes were affected by exposure to distinct BPA concentrations, including mitochondrial processes, nucleobase-containing small molecule metabolic processes, transcription from the RNA polymerase II promoter, and mitosis and associated processes, the number and magnitude of differentially expressed genes differ between low and high inhibition concentration treatments. For example, exposure to 300 mg/L BPA resulted in severe changes in the expression levels of several genes involved in oxidative phosphorylation, the tricarboxylic acid cycle, ribosomal activity, replication, and chemical responses. Conversely, only slight changes were observed in the expression of genes involved in these processes in cells exposed to 50 mg/L BPA. These results demonstrate that yeast cells respond to BPA in a concentration-dependent manner at the transcriptional level via different genes and provide insight into the molecular mechanisms underlying the modes of action of BPA.
- MakaleYalnız künye2017The effect of TiO2 coating on biological NiTi alloys after micro-arc oxidation treatment for corrosion resistance
Sukuroglu, Ebru Emine; Sukuroglu, Suleyman; Akar, Kubra; Totik, Yasar; Efeoglu, Ihsan; Arslan, Ersin
NiTi alloys exhibit good properties, such as shape memory behavior, high corrosion resistant, having the closest elasticity modulus of a human bone and superior biocompatibility properties. However, the surface problems that arise during the use of this alloy limit the usage in the industry and health sector. In recent years, micro-arc oxidation method is used to improve the surface properties and increase the usage of these alloys. In this study, the TiO2 coatings were deposited on the NiTi substrates. The surface topography, morphology, crystallographic structure, and thickness of the coatings were determined using scanning electron microscopy and X-ray diffraction. The corrosion properties were investigated using potentiostat test unit in two different media such as NaCl solution and simulated body fluid. The results show that the coated samples have higher corrosion resistance than uncoated samples in the two different media.
- MakaleAçık Erişim2017Sexual health literacy as a predictor of reproductive health and family planning attitudes among university students: a cross-sectional study
Karaahmet, Aysu Yıldız; Bilgiç, Fatma Şule; Karakaş, Sevda
Introduction: This study was conducted to investigate the relationship between sexual health literacy (SHL) and reproductive health and family planning (RHFP) attitudes among university students and to identify the sociodemographic and informational predictors influencing these variables. Methods: A descriptive, cross-sectional design was employed with a sample of 867 university students aged 18-35 in Türkiye between May and September 2024. Data were collected using a Sociodemographic Questionnaire, the Sexual Health Literacy Scale (SHLS), and the Reproductive Health and Family Planning Attitude Scale (RHFPAS). Data analysis included Pearson correlation and multiple linear regression models to determine predictors and relationships. Results: The findings revealed a strong positive correlation between SHL and RHFP attitudes (r = 0.880, P < .05). Multiple linear regression analysis showed that total SHLS scores and students’ conceptual definitions of sexual health were significant predictors of RHFP attitudes. In particular, the knowledge and attitude subscales of the SHLS were identified as key determinants. Furthermore, residence type, sexual activity status, and information sources were found to significantly influence both SHL levels and RHFP attitudes. Discussion: SHL is a critical determinant in shaping the RHFP attitudes of young adults. Higher literacy levels directly correlate with more positive attitudes toward reproductive health services, suggesting that targeted educational interventions are necessary to improve health outcomes in this population.
- MakaleAçık Erişim2017Detection of autoantibodies against carbonic anhydrase I and II in the plasma of patients with gastric cancer
Mentese, Ahmet; Fidan, Evren; Alver, Ahmet; Demir, Selim; Yaman, Serap Ozer; Sumer, Aysegul; Fidan, Sami; Kavgaci, Halil; Turan, Ibrahim
Cancer is the second leading cause of death and gastric cancer is the fourth most common cancer type worldwide. Investigation of autoantibodies in cancer patients has been a popular research area in recent years. The aim of the current study was to investigate carbonic anhydrase I and II (CA I and II) autoantibodies in the plasma of subjects with gastric cancer based on the information and considerations of autoimmune relation of gastric cancer. Anti-CA I and II antibody levels were investigated by ELISA in plasma samples of fifty two patients with gastric cancer and thirty five healthy peers. Anti-CA I and II antibody titers of the gastric cancer group were significantly higher compared with the control group (p = 0.004, p = 0.0001, respectively). Plasma anti-CA I levels of the metastatic group were lower than the non-metastatic group and this difference was found statistically significant (p < 0.05), but there was no statistical difference between plasma anti-CA II levels of the groups. CA I and II autoantibody titers in patients with gastric cancer were found higher compared to healthy subjects and the results suggest that these autoantibodies may be involved in the pathogenesis of gastric cancer.
- MakaleYalnız künye2017Genome reprogramming in Saccharomyces cerevisiae upon nonylphenol exposure
Bereketoglu, Ceyhun; Arga, Kazim Yalcin; Eraslan, Serpil; Mertoglu, Bulent
Bioaccumulative environmental estrogen, nonylphenol (NP; 4-nonylphenol), is widely used as a nonionic surfactant and can affect human health. Since genomes of Saccharomyces cerevisiae and higher eukaryotes share many structural and functional similarities, we investigated subcellular effects of NP on S. cerevisiae BY4742 cells by analyzing genome-wide transcriptional profiles. We examined effects of low (1 mg/l; <15% cell number reduction) and high (5 mg/l; >65% cell number reduction) inhibitory concentration exposures for 120 or 180 min. After 120 and 180 min of 1 mg/l NP exposure, 187 (63 downregulated, 124 upregulated) and 103 genes (56 downregulated, 47 upregulated), respectively, were differentially expressed. Similarly, 678 (168 repressed, 510 induced) and 688 genes (215 repressed, 473 induced) were differentially expressed in cells exposed to 5 mg/l NP for 120 and 180 min, respectively. Only 15 downregulated and 63 upregulated genes were common between low and high NP inhibitory concentration exposure for 120 min, whereas 16 downregulated and 31 upregulated genes were common after the 180-min exposure. Several processes/pathways were prominently affected by either low or high inhibitory concentration exposure, while certain processes were affected by both inhibitory concentrations, including ion transport, response to chemicals, transmembrane transport, cellular amino acids, and carbohydrate metabolism. While minimal expression changes were observed with low inhibitory concentration exposure, 5 mg/l NP treatment induced substantial expression changes in genes involved in oxidative phosphorylation, cell wall biogenesis, ribosomal biogenesis, and RNA processing, and encoding heat shock proteins and ubiquitin-conjugating enzymes. Collectively, these results provide considerable information on effects of NP at the molecular level.
- MakaleAçık Erişim2017Effect of brewing conditions on antioxidant properties of rosehip tea beverage: study by response surface methodology
İlyasoğlu, Huri; Arpa, Tuba Eda
The aim of this study was to investigate the effects of brewing conditions (infusion time and temperature) on the antioxidant properties of rosehip tea beverage. The ascorbic acid content, total phenolic content (TPC), and ferric reducing antioxidant power (FRAP) of rosehip tea beverage were analysed. A two-factor and three-level central composite design was applied to evaluate the effects of the variables on the responses. The best quadratic models were obtained for all responses. The generated models were validated under the optimal conditions. At the optimal conditions, the rosehip tea beverage had 3.15 mg 100 mL−1 of ascorbic acid, 61.44 mg 100 mL−1 of TPC, and 2591 µmol of FRAP. The best brewing conditions for the rosehip tea beverage were found to be an infusion time of 6–8 min at temperatures of 84–86 °C.
- MakaleAçık Erişim2017A new colorimetric DPPH• scavenging activity method with no need for a spectrophotometer applied on synthetic and natural antioxidants and medicinal herbs
Akar, Zeynep; Küçük, Murat; Doğan, Hacer
2,2-Diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging, the most commonly used antioxidant method with more than seventeen thousand articles cited, is very practical; however, as with most assays, it has the major disadvantage of dependence on a spectrophotometer. To overcome this drawback, the colorimetric determination of the antioxidant activity using a scanner and freely available Image J software was developed. In this new method, the mixtures of solutions of DPPH• and standard antioxidants or extracts of common medicinal herbs were dropped onto TLC plates, after an incubation period. The spot images were evaluated with Image J software to determine CSC50 values, the sample concentrations providing 50% colour reduction, which were very similar with the SC50 values obtained with spectrophotometric method. The advantages of the new method are the use of lower amounts of reagents and solvents, no need for costly spectrophotometers, and thus significantly lowered costs, and convenient implementation in any environment and situation.
- MakaleYalnız künye2017An injectable alginate-based hydrogel for microfluidic applications
Akay, Seref; Heils, Rene; Trieu, Hoc Khiem; Smirnova, Irina; Yesil-Celiktas, Ozlem
The objective of this study was to develop an injectable alginate based formulation for immobilizing enzymes into microfluidic systems. The gelation was induced upon lowering the pH by addition of D-glucono-δ-lactone (GDL) and release of Ca+ ions from solid CaCO3. The effects of GDL concentration on enzymatic activity and gelation time were investigated. The results indicated that increasing the GDL concentration increased both surface area and enzymatic activity. Also, chitosan was added to the formulation at different ratios to enhance the stability of enzyme during immobilization. For microfluidic application, 100 μl spiral coil single channel microchip was fabricated and alginate GDL mixture containing β-glucosidase was injected to the microchannel prior to gelation. Enzymatic conversion was performed by pumping substrate (pNPG) through the microchannel. The results indicated that the entire substrate was converted continuously during 24 h without any leakage or deactivation of immobilized enzyme.
- MakaleYalnız künye2017An on-line HPLC system for detection of antioxidant compounds in some plant extracts by comparing three different methods
Arslan Burnaz, Nesibe; Küçük, Murat; Akar, Zeynep
Echinacea (Echinacea purpurea), green tea (Camellia sinensis) and yaylacayi (Thymus praecox OPIZ subsp. grossheimii (Ronniger) Jalas) are herbs used in traditional medicine because of their beneficial health effects. A high performance liquid chromatography (HPLC) post-column method was developed by coupling HPLC with on-line antioxidant assays using diode array (DAD) and ultraviolet (UV) detectors. Thus antioxidant compounds and fifteen phenolic standards were detected in echinacea, green tea and yaylacayi methanol extracts simultaneously. Later on, the developed on-line HPLC coupled system was used to compare three different antioxidant methods, ABTS [2,2′-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)], DPPH (2,2-diphenyl-1-picrylhydrazyl and FRAP (Ferric reducing antioxidant power). Eight compounds with antioxidant activity were identified as gallic acid, protocatechuic aldehyde, p-OH benzoic acid, chlorogenic acid, caffeic acid, vanillin, ferulic acid, and rosmarinic acid. For validation purposes, LOD (limit of detection) (0.36–14.68 μg/mL) and LOQ (limit of quantification) (1.35–48.92 μg/mL) values were calculated for six standards. The results showed that while the post-column ABTS and FRAP assays were repeatable, sensitive and supportive of each other, the post-column DPPH assay did not provide reliable results. Also due to the base-line noise and drifts in post-column DPPH assay, identification and quantitation of analytes could not be done accurately.
- MakaleYalnız künye2017Carbonic anhydrase I and II autoantibodies in Behcet's disease
Mentese, A.; Alver, A.; Demir, S.; Sumer, A.; Yaman S, Ozer; Karkucak, M.; Capkin A, Aydin; Us, Altay D.; Turan, I
Background: Behcet's disease ( BD) is a vasculitis, seen more frequently around the Mediterranean and the Far East, and evinces with oral and genital ulcerations, skin lesions and uveitis. Carbonic anhydrase ( CA) is a metalloenzyme which is widely distributed in the living world, and it is essential for the regulation of acid-base balance. Anti-CA antibodies have been reported in many disorders, such as systemic lupus erythematosus, Sjogren's syndrome, rheumatoid arthritis, endometriosis, idiopathic chronic pancreatitis, type 1 diabetes and Graves' disease. The goal of this study was to investigate CA I and II autoantibodies in BD. Methods: 35 patients with BD and 29 healthy controls were included in the study and CA I and II autoantibody levels were investigated by ELISA. Results: The CA I and II autoantibody levels of BD group were significantly higher than the healthy group (p= 0.013, p= 0.0001, respectively). A cut-off value of 0.250 absorbance unit (ABSU) for anti-CA I was associated with 34% sensitivity and 100% specificity and a cut-off value of 0.171 ABSU for anti-CA II was associated with 54% sensitivity and 100% specificity for predicting BD. Conclusion: The CA I and II autoantibody levels in pa-tients with BD were found higher compared to control group and the results suggest that CA I and II autoantibodies may be involved in the pathogenesis of BD