Effect of Cold and Fluctuating Storage Conditions on Quality of Dried Apricot

Fatih Sen,Ismail Karacali,Fulya Turantas 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.3

The study was conducted with apricots (Prunus armeniaca ‘Hacı Halilo?lu’) treated with SO₂ and sun-dried traditionally for 2 years. Fruit were put in closed wooden crates (40 × 40 × 90 ㎝) at a depth of 70 ㎝ and then stored either under cold conditions (4℃, 65% RH) or at fluctuating temperatures. Samples were taken out from the top, middle, and bottom sections of the crates after 90, 180, and 270 days of storage. Changes in fruit quality were assessed through analyses of moisture content, water activity, tissue hardness, SO₂ content, fruit color (CIE L<SUP>*</SUP>, a<SUP>*</SUP>, and b<SUP>*</SUP>). Total viable yeast, mould, osmophilic yeast, and total coliform counts were determined. Quality changes under cold storage were restricted. The decreases in SO₂ and color values during storage were particularly noticeable at the end of the storage period and in fruits stored under fluctuating storage compared to those in cold storage. Fruit with high SO₂ content could be stored for 270 days under fluctuating storage, although high levels of SO₂ applications must be avoided because of the SO₂ maximum residue limits. On the other hand, cold storage conditions provided 270 days of successful storage in sun-dried apricots possessing low SO₂ levels (<1500 ppm).

The Presence of Fragmented QRS on 12-Lead Electrocardiography in Patients with Coronary Artery Ectasia

Fatih Sen,Samet Yılmaz,Mevlüt Serdar Kuyumcu,Özcan Özeke,Mustafa Mücahit Balcı,Sinan Aydog˘du 대한심장학회 2014 Korean Circulation Journal Vol.44 No.5

Background and Objectives: Coronary artery ectasia (CAE) is an angiographic finding characterized by dilation of an arterial segment with a diameter at least 1.5 times that of its adjacent normal coronary artery. Fragmented QRS (fQRS) complexes are electrocardiographic signals which reflect altered ventricular conduction around regions of a myocardial scar and/or ischaemia. In the present study, we aimed to evaluate the presence of fQRS in patients with CAE. Subjects and Methods: The study population included 100 patients with isolated CAE without coronary artery disease (CAD) and 80 angiographically normal controls. fQRS was defined as the presence of an additional R wave or notching of R or S wave or the presence of fragmentation in two contiguous leads corresponding to a major coronary artery territory. Results: The two groups were similar in terms of age, sex, hypertension, dyslipidemia, and family history of CAD. The presence of fQRS was significantly (p<0.05) higher in the CAE group than that in the normal coronary artery group (29% vs. 6.2%, p=0.008). Isolated CAE were detected most commonly in the right coronary artery (61%), followed by left anterior descending artery (52%), left circumflex artery (36%), and left main artery (9%). Multivariate stepwise logistic regression analysis showed that CAE {odds ratio (OR) 1.412; 95% confidence interval (CI) 1.085–1.541; p=0.003} and diabetes (OR 1.310; 95% CI 1.025–1.482; p=0.041) were independently associated with fQRS. Conclusion: The presence of fragmented QRS associated with increased risk for arrhythmias and cardiovascular mortality was significantly higher in patients with CAE than in patient with normal coronary artery. Further studies are needed to determine whether the presence of fragmented QRS is a possible new risk factor for patients with CAE.

Quality and Nutritional Property Changes in Stored Dried Apricots Fumigated by Sulfur Dioxide

Fatih Sen,Mustafa Ozgen,Bayram Murat Asma,Uygun Aksoy 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.2

Apricots are grown in many countries and are marketed as dried or fresh. Sulfur fumigation is preferred as a low-cost pre-treatment to maintain apricot color. This study aims to determine the effect of sulfur dioxide (SO2) concentration on quality and nutritional properties of dried apricot fruits during storage. Apricot fruits were treated with different concentrations of SO2 (1,250, 2,000, and 3,500 mg・kg-1) and then stored at 20°C under 50-65% relative humidity conditions for 18 months. Fruit SO2 concentration decreased rapidly during the initial stage and then decreased at a slower rate. Fruit color darkening became more pronounced after 12 months, especially in the fruit treated with 1,250 and 2,000 mg・kg-1 SO2. After 18 months of storage, total phenolic content (839-890 mg GAE 100 g-1dry weight), antioxidant activity (9.4-11.6 μmol TE g-1 dry weight), and β-carotene levels (42.7-47.6 mg・kg-1) of all treatments varied only slightly, despite lower values overall. Therefore, SO2 levels must be chosen based on the expected storage conditions and length of the storage period.

Phosphine as a Methy. Bromide Alternative in the Dried Fig Sector in Turkey

Uygun Aksoy,Fatih Sen,Kamer Betul Meyvaci 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

A novel design procedure for tractor clutch fingers by using optimization and response surface methods

Oguz Dogan,Fatih Karpat,Celalettin Yuce,Necmettin Kaya,Nurettin Yavuz,Hasan Sen 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

This paper presents a methodology for re-designing a failed tractor transmission component subjected to cyclic loading. Unlike other vehicles, tractors cope with tough working conditions. Thus, it is necessary to re-design components by using modern optimization techniques. To extend their service life, we present a design methodology for a failed tractor clutch power take-off finger. The finger was completely re-designed using topology and shape optimization approach. Stress-life based fatigue analyses were performed. Shape optimization and response surface methodology were conducted to obtain optimum dimensions of the finger. Two design parameters were selected for the design of experiment method and 15 cases were analyzed. By using design of the experiment method, three responses were obtained: Maximum stresses, mass, and displacement depending on the selected the design parameters. After solving the optimization problem, we achieved a maximum stress and mass reduction of 14% and 6%, respectively. The stiffness was improved up to 31.6% compared to the initial design.

Optimization of Magnesium Phosphide Treatment Used to Control Major Dried Fig Storage Pests

Kamer Betul Meyvaci,Fatih Sen,Uygun Aksoy 한국원예학회 2010 Horticulture, Environment, and Biotechnology Vol.51 No.1

Methyl bromide (MeBr), a fumigant widely used to control storage pests in dried fruit and nut industry, is banned for use because of ozone layer depletion according to the Montreal Protocol. Dried fig industry is the most affected from MeBr ban due to prevalence of storage pests namely fig moth (Ephestia cautella). Magnesium phosphide was tested for exposure times of 3 and 5 days at 0.70 g · m?³ phosphine (PH₃) and 1.33 g · m?³ PH₃ of dried fig in gas-tight storage units containing 15 ton of dried figs in boxes of 25-30 ㎏ to control two major pests of dried figs, fig moth and fig mite (Carpoglyphus lactis). The control fruits were fumigated with MeBr at 40 g · m?³ for 24 h. The results proved that the tested concentrations and exposure periods to PH₃ provided that 100% mortality of the test species. After exposure to PH₃ or MeBr, fruit quality was preserved under ambient storage conditions for 4 months. The lower dosage of PH₃ does not cause any adverse effect on fruit quality.

Modified screen‑printed electrochemical biosensor design compatible with mobile phones for detection of miR‑141 used to pancreatic cancer biomarker

Muhammed Bekmezci,Ramazan Bayat,Merve Akin,Zeynep Kazel Coguplugil,Fatih Sen 한국탄소학회 2023 Carbon Letters Vol.33 No.6

MicroRNAs (miRNAs) are emerging materials as ideal biomarkers for noninvasive cancer detection in the early phase. In this article, a simple and label-free electrochemical miRNA biosensor was developed. A single-stranded DNA (ss-DNA) probes were successfully mapped to f-MWCNT and hybridized with the target miR-141 sequence. The optimum peak points of the obtained hybridization were determined using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) methods. Significant peaks were observed in the results, depending on miR-141 at different concentrations. The linear relationship (ν) between redox peak currents (Ip) and scanning rate indicated that electron transfer (ET) between miR-141 and the electrode surface was accomplished successfully. In DPV measurements, miR-141 was measured with a low detection limit (LOD) in the 1.3–12 nM concentration range, and the LOD and limit of quantification (LOQ) results were found to be 3 and 9.1 pM, respectively. Besides, selectivity test was investigated for the biosensor using different target analytes and a significant difference in value was observed between the peak currents of miR-141, and other target molecules. This developed strategy has been found to detect miR-141 sensitively, selectively and without tags, and its integration into mobile devices has been successfully carried out.

The use of polymer/carbon based material as an efficient and low‑cost electrochemical sensor for rapid electrochemical detection of dopamine

Merve Akin,Ramazan Bayat,Muhammed Bekmezci,Zeynep Kazel Coguplugil,Fatih Sen,Mehdi Baghayeri,Afsaneh Kaffash,Fatemah Tehranejad‑Javazmi,Iran Sheikhshoaie 한국탄소학회 2023 Carbon Letters Vol.33 No.7

In this research, reduced graphene oxide/polypyrrole (rGO/PPy) particles were synthesized and used to measure the amount of dopamine (DA) electrochemically. The obtained rGO/PPy particle was characterized by Fourier Transform Infrared Spectrophotometer (FTIR), UV–Visible Spectrophotometer (UV–Vis), and X-Ray Diffraction Diffractometry (XRD). To investigate the DA sensor performance, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to acquire electrochemical measurements of the sensor. Current values of 1.65 and 5.9 mA were observed in the CV at 0.2 mM and 1.2 mM concentrations of target molecule, respectively. Under optimized conditions, the linear calibration plots were found to exhibit significant sensitivity in the linear range of 0.2 and 1.2 mM, with a corresponding detection limit of 0.061 μM for DA. The results obtained were similar to the sensor results of DA made using precious metals. This work was a demonstration of the feasibility of high-sensitivity electrochemical analysis with conductive carbon materials without the use of precious metals. It was also observed that the cost-effective rGO/PPy exhibited a very high potential for DA detection.