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  • Author: Mehmet Öztürk x
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Open access

Mehmet Ali Öztürk

Abstract

We define and study the extended centroid of a prime Γ-semiring. We show that the extended centroid is a Γ-semifield and give some properties of the centroid of a prime Γ-semiring.

Open access

Saber Boutellaa, Amar Zellagui, Mehmet Öztürk, Chawki Bensouici, Özge Tokul Ölmez, Mouna Menakh and Mehmet Emin Duru

Abstract

In this study, phenolic compounds from Crithmum maritimum L. n-butanol soluble fraction were quantified and identified spectrophotometrically and by using HPLC-DAD technics. They equally investigated for their antioxidant potential utilizing six in vitro assays: DPPH, ABTS•+, O2 •−, Bleaching of β-carotene in linoleic acid, CUPRAC and Ferric reducing power. High amounts of total phenolics and flavonoids were recorded: 161.57± 0.479 μg GAeq.mg−1 and 31.56± 0.291 μg Qeq.mg−1 respectively. Nine compounds among them hydroxicinnamic acid and hydroxybenzoic acid derivatives, coumarins and flavonoids were identified. Chlorogenic acid known for their various pharmacological properties was detected as major compound of the extract. Rutin, vanillin, trans-2-hydroxycinnamic acid, ellagic acid, ferrulic acid, 6,7 dihydroxy coumarin, methyl 1,4 benzoquinone and trans-cinnamic acid were also detected. The extract was found to exhibit strong antioxidant capacities in all systems. Based on these results, it is right to conclude the n-butanol extract is promising source of natural antioxidants.

Open access

Goksel Erbas, Ugur Parin, Suheyla Turkyilmaz, Nese Ucan, Mehmet Ozturk and Osman Kaya

Abstract

In this study, determination of enterococcus species that were isolated from mastitic milk samples, investigation of their susceptibilities to antibiotics and identification of the existence of resistance genes in resistant strains were conducted. The specimens consist of 600 mastitic milk samples that were collected from 242 cows. Isolation of enterococcus was carried out in selective media and 94 (15.6%) Enterococcus spp. were isolated. A total of 94 species of Enterococci were identified using both sequencing and polymerase chain reaction (PCR). Enterococcus spp. isolates belong to 5 different species (E. faecalis, E. faecium, E. durans, E. hirae, E. mundtii) in sequence analysis and 4 different species (E. faecalis, E. faecium, E. durans, E. hirae) were identify by PCR method with specific primers. Analyzing 94 enterococcus strains by antibiotic sensitiveness test a high rate of resistance to tetracycline in 77 (81.9%) isolates was shown. The tet resistance genes were identified as follows: 54 were tetM positive, 23 were tetK positive and 17 were positive on tetM and tetK. Resistance to erythromycin was established in 27 (28.7%) isolates (25 ermB) while the chloramphenicol resistance gene was found in 10 (10.7%) of isolates and the cat gene was identified in nine samples and one isolate was resistant to vancomycin (1.06%) with the VanA gene confirmed. In conclusion, it was shown that E. faecalis has the biggest role in enterococcus originated mastitis and these strains were found to be mostly resistant to tetracycline. One vancomycine resistant isolate that had the VanA gene was also determined.

Open access

Yasin Ozdemir, Nesrin Aktepe Tangu, Aysun Ozturk, Mehmet Emin Akcay and Sezai Ercisli

Abstract

Some important physical, chemical and sensory characteristics of raw and processed olives (processed by the same scratched table olive process) were investigated. In the study, six candidate cultivars obtained by cross-breeding and one standard cultivar (‘Domat’) grown together in an olive breeding and observation plot in the Ataturk Central Horticultural Research Institute in Turkey were investigated. Fruit weight and flesh-to-seed ratio of fresh raw olives ranged from 5.18 to 7.65 g and 4.8 to 6.3, respectively. LT011 had the highest fruit weight, whereas LT001 and LE001 had the highest flesh-to-seed ratio. Total phenolic content and antioxidant activity of the produced table olives were estimated between 102 and 141 mg gallic acid equivalents per 100 g−1fresh weight, and 13.4 and 14.9 µmol Trolox 100 g−1, respectively. Fruits of LT001 had higher appearance, taste, bitterness and general appreciation scores than the others. LT001 showed a lesser loss of oleuropein absorbance and antioxidant activity than the others during processing. The results of this study revealed that LE001, LT001 and LT011 had superior characteristics for the production of scratched green table olives.

Open access

Durmuş Ayan, Mehmet Şeneş, Ayşe Banu Çaycı, Sibel Söylemez, Nezaket Eren, Yüksel Altuntaş and Feyza Yener Öztürk

Summary

Background

The aim of this study is to examine the relationship among the changes in activities of paraoxonase (PON), arylesterase (ARE) and homocysteine thiolactonase (HTLase) enzyme having antioxidant properties and the development of diabetic nephropathy (DN), one of the most common complications of diabetes.

Methods

Normoalbuminuric type-2 diabetic patients (Group II, n=100), microalbuminuric type 2 diabetic patients (Group III, n=100) and the control group (Group I, n=100) were included in the study. The age and gender of the patient groups matched with the age and gender of the control group. HTLase, PON and ARE enzyme activities were measured by the spectrophotometric method using a g-thiobutyrinolactone, paraoxon, and phenylacetate substrates respectively. In this study, an autoanalyzer application was developed in order to measure HTLase enzyme activity for the first time.

Results

Serum HTLase, ARE and PON activities of Group III and Group II were significantly low compared to HTLase, ARE and PON results of Group I (p<0.05).

Conclusions

Based on our results, PON, ARE and HTLase enzyme activities were found to be decreased due to the increase in the degree of DN.

Open access

Nil Baran Acarali, Emre Ozturk, Melek Bardakci, Mehmet Burcin Piskin and Nurcan Tugrul

Streszczenie

Celem tego artykułu jest synteza boranu cynku przy użyciu węglanu cynku, kwasu borowego, referencyjnego boranu cynku (ZB) jako substancji aktywnej oraz badanie efektywności tego procesu modyfikowanego odczynnikami i parametrami reakcji na hydrofobowość i wydajność syntezy boranu cynku. Dotyczy to działania różnych czynników modyfikujących hydrofobowość i parametry reakcji: glikol propylenowy (PG) (0−6%, kerozyna 1−6%, kwas oleinowy (OA) 1−6% oraz rozpuszczalniki: alkohol izopropylowy (IPA), etanol i metanol. Po pierwsze, badano jak wpływają następujące parametry reakcji na uzysk boranu cynku: czas reakcji (1−5 h), wskaźnik reaktywacji (H3BO3 : ZnO), (2−5), udział zarodków krystalizacji (0−1,5%) w odniesieniu do kwasu borowego, temperatura reakcji (50−120°C), temperatura chłodzenia (10−80 °C), szybkość mieszania (400−700 obr./min). Ponadto, reakcje były przeprowadzone w określonych warunkach mieszania mechanicznego i magnetycznego. Wytwarzany boran cynku ze względu na hydrofobowość badano metodami: dyfrakcji rentgenowskiej XRD, spektroskopii FT-IR oraz pomiarami kąta zwilżania. Reasumując, stwierdzono, że boran cynku można otrzymać z powodzeniem z różnymi rozpuszczalnikami wpływającymi na jego hydrofobowość.