Showing papers by "Mustafa Yilmaz published in 2017"

Effects of exposure to 2100MHz GSM-like radiofrequency electromagnetic field on auditory system of rats.

Abstract: Introduction The use of mobile phones has become widespread in recent years. Although beneficial from the communication viewpoint, the electromagnetic fields generated by mobile phones may cause unwanted biological changes in the human body. Objective In this study, we aimed to evaluate the effects of 2100 MHz Global System for Mobile communication (GSM-like) electromagnetic field, generated by an electromagnetic fields generator, on the auditory system of rats by using electrophysiological, histopathologic and immunohistochemical methods. Methods Fourteen adult Wistar albino rats were included in the study. The rats were divided randomly into two groups of seven rats each. The study group was exposed continuously for 30 days to a 2100 MHz electromagnetic fields with a signal level (power) of 5.4 dBm (3.47 mW) to simulate the talk mode on a mobile phone. The control group was not exposed to the aforementioned electromagnetic fields. After 30 days, the Auditory Brainstem Responses of both groups were recorded and the rats were sacrificed. The cochlear nuclei were evaluated by histopathologic and immunohistochemical methods. Results The Auditory Brainstem Responses records of the two groups did not differ significantly. The histopathologic analysis showed increased degeneration signs in the study group (p = 0.007). In addition, immunohistochemical analysis revealed increased apoptotic index in the study group compared to that in the control group (p = 0.002). Conclusion The results support that long-term exposure to a GSM-like 2100 MHz electromagnetic fields causes an increase in neuronal degeneration and apoptosis in the auditory system.

Ozone Prevents Cochlear Damage From Ischemia-Reperfusion Injury in Guinea Pigs.

Abstract: The cochlea is an end organ, which is metabolically dependent on a nutrient and oxygen supply to maintain its normal physiological function. Cochlear ischemia and reperfusion (IR) injury is considered one of the most important causes of human idiopathic sudden sensorineural hearing loss. The aim of the present study was to study the efficacy of ozone therapy against cochlear damage caused by IR injury and to investigate the potential clinical use of this treatment for sudden deafness. Twenty-eight guinea pigs were randomized into four groups. The sham group (S) (n = 7) was administered physiological saline intraperitoneally (i.p.) for 7 days. The ozone group (O) (n = 7) was administered 1 mg/kg of ozone i.p. for 7 days. In the IR + O group (n = 7), 1 mg/kg of ozone was administered i.p. for 7 days before IR injury. On the eighth day, the IR + O group was subjected to cochlear ischemia for 15 min by occluding the bilateral vertebral artery and vein with a nontraumatic clamp and then reperfusion for 2 h. The IR group was subjected to cochlear IR injury. After the IR procedure, the guinea pigs were sacrificed on the same day. In a general histological evaluation, cochlear and spiral ganglionic tissues were examined with a light microscope, and apoptotic cells were counted by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The apoptotic index (AI) was then calculated. Blood samples were sent for analyses of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase, malondialdehyde (MDA), the total oxidant score (TOS), and total antioxidant capacity (TAC). Data were evaluated statistically using the Kruskal-Wallis test. The AI was highest in the IR group. The AI of the IR + O group was lower than that of the IR group. The biochemical antioxidant parameters SOD and GSH-Px and the TAC values were highest in the O group and lowest in the IR group. The MDA level and TOS were highest in the IR group and lowest in the O group. Controlled ozone administration stimulated endogenous antioxidant defense systems, thereby helping the body to combat IR injury. Although this study revealed a statistically significant decrease in cochlear IR damage following ozone therapy, further studies will be necessary to explain the protective mechanisms of ozone therapy in cochlear IR injury.

Dual Fluorescence Response of Newly Synthesized Naphthalene Appended Calix[4]arene Derivative towards Cu 2+ and I.

Abstract: In the present work new naphthalene appended calix[4]arene (NAC4) ie 5,11,17,23-tetra-tert-butyl-25,27-di((2-amido(1-naphthlene)ethyl)-26,28-dihydroxy calix[4]arene (6) was designed and successfully synthesized NAC4 was characterized by 1HNMR and FTIR To explore the complexation behavior and fluorescence response of NAC4, UV-visible and fluorescence studies were carried out with series of metal ions and anions that include solvatochromic effect, ion-ligand response and interference on absorption and fluorescence spectra Results show that the NAC4 is highly Cu2+ and I−selective The ligand ion interaction follow photoinduced electron transfer (PET) mechanism The stiochiomatric ratio of ion-ligand was calculated as 1:1 by using Job’s plot method and binding constant Ka values were calculated by using Benesi-Hildebrand equation as 1×103 and 8×102 M−1 with detection limit of 105×10−5 and 40×10−5 M for Cu2+ and I− respectively

A New Piperidine Derivatized-Schiff Base Based “Turn-on” Cu 2+ Chemo-Sensor

Abstract: In this study, we report the synthesis of new Schiff base E-1-(((1-benzylpiperidin-4-yl)imino)methyl)naphthalenee-2-ol (L) and evaluation of its fluorescence response toward Cu2+ ion. Preliminary, solvent effect, metal selectivity and metal ligand ratio were analyzed through UV-Visible study. Fluorescence response toward Cu2+ was carried to assess the fluorescent property of synthesized Schiff base. The probe exhibited a higher fluorescence enhancement in the presence of Cu2+ over other metal ions (Ni2+, Zn2+, Hg2+, Co2+, Cd2+, Al3+, Fe2+, and Pb2+). The binding stoichiometry between L and Cu2+ has been investigated using Job’s plot and Benesi-Hildebrand equation and it was found that ligand L can form 1:1 L-Cu2+ complex with binding constant (K a) of 4 × 104 LM−1.

Enantioselective resolution of racemic flurbiprofen methyl ester by lipase encapsulated mercapto calix[4]arenes capped Fe3O4 nanoparticles.

Abstract: This work presents the synthesis of new mercapto calix[4]arenes derivatives (4 and 5). These derivatives were capped on Fe3O4 magnetic nanoparticles and subsequently encapsulated with Candida rugosa through sol–gel method to furnish enc-4 and enc-5, respectively, to enhance catalytic activity and enantioselectivity of lipase for hydrolysis reaction of racemic flurbiprofen methyl ester. Catalytic activity and enantioselectivity of enc-4 and enc-5 were assayed at different pH and temperature conditions and it was found that the resultant encapsulated enzyme exhibited higher thermal and operational stabilities compared to the free lipase in which enc-5 showed the excellent rate of enantioselectivity (E = 176) for S-flurbiprofen better than free lipase (E = 137) at pH 7 and 35 °C for 48 h. The time study shows that enantioselectivity reached the maximum value of E = 244 after 72 h. Catalytic activity of these materials was hardly affected by 20 and 23% after five usages of enc-4 and enc-5, respectively.

Chemical Profile of Malva Neglecta and Malvella Sherardiana by Lc- MS/MS, GC/MS and Their Anticholinesterase, Antimicrobial and Antioxidant Properties With Aflatoxin-Contents

Abstract: Bu calismanin amaci Malva neglecta ve Malvella sherardiana turlerinin antioksidan, antikolinesteraz ve antimikrobiyal aktiviterini, aflatoksin icerigi ile fenolik bilesik ve yag asidi profillerini LC-MS/MS ve GC/MS ile belirlemektir. Incelenen yirmi yedi bilesikten, M. neglecta ve M. sherardiana turlerinde en bol bulunan bilesiklerin sirasiyla malik (13108.97 μg/g) ve 4-OH benzoik asit (2200.57 μg/g) oldugu saptanmistir. M. neglecta turunun metanol ekstresindeki toplam flavonoid icerigin (15.58 μg QEs/mg ekstre) toplam fenolik icerikten (68.29 μg PEs/ mg ekstre) daha az oldugu belirlenmistir. Bitkilerin metanol ekstresi calisilan antioksidan aktivite belirleme yontemlerinin tumunde en yuksek aktiviteyi gostermistir. En iyi kolinesteraz enzim inhibisyonu ise M. neglecta turunun metanol ekstresi tarafindan kaydedilmistir (%53.68 AChE enzim inhibisyonu ve %63.95 BChE enzim inhibisyonu). Bitkilerin aseton ekstreleri ise C. albicans turune karsi orta duzeyde antimikrobiyal aktivite gostermistir. Bu calismadan elde edilen sonuclar, M. neglecta ve M. sherardiana turlerinin yuksek fenolik asit icerigi ve antioksidan aktivitesinden dolayi besin kaynagi olarak kullanilabilecegini gostermektedir. Ayrica ekstreler aflatoxin icermemektedir.

Synthesis of environmentally friendly, efficient and highly recyclable Lewis acid-type calix[4]arene catalysts containing flexible or bulky groups for the Mannich reaction

Abstract: Two new calix[4]arene-based Lewis acid-type catalysts containing flexible and bulky groups (2 and 3) were successfully synthesized. Their structures were characterized using FTIR, 1H-NMR, COSY-NMR, 13C-NMR, APT-NMR, and elemental analysis techniques. Moreover, to provide easily recyclable, environmentally benign, cost effective and reusable catalysts, these calix[4]arene-based Lewis acid-type catalysts were grafted onto epoxyl-functionalized silica-coated Fe3O4 magnetic nanoparticles (EPPTMS-MN) to afford their corresponding calixarene-grafted magnetic nanoparticles (TMAC[4]But-MNP and P(Ph)3C[4]But-MNP). FTIR, TGA, TEM, VSM and elemental analysis techniques were performed to confirm their structures. In addition, the catalytic capabilities of four Lewis acid-type calixarene catalysts were evaluated in a three component Mannich reaction of benzaldehyde with aniline and acetophenone in aqueous media without co-solvents. The association of the effects of functional groups (flexible and bulky), molar equivalents, amount of water used, and reaction durations on their catalytic efficacies were also evaluated.

Epicardial Adipose Tissue Thickness and Carotid Intima-Media Thickness in Hemodialysis Patients.

Abstract: BACKGROUND It is well-known that cardiovascular risk and all-cause mortality is increased in hemodialysis patients. Epicardial fat thickness (EFT), which reflects visceral adiposity, has been suggested as a new cardiometabolic risk factor. The purpose of this study was to investigate EFT in hemodialysis patients. METHODS A total of 144 consecutive patients (60 hemodialysis patients and 84 controls) were enrolled into the study, and patients with diabetes mellitus and cardiovascular diseases (CVD) were excluded. EFT was measured on the free wall of the right ventricle at end-diastole from the parasternal long-axis view by standard transthorasic 2D echocardiography. RESULTS The groups were similar in terms of sex distribution, age, blood pressure, heart rate and frequencies of CAD risk factors including smoking status, family history of CAD and hypertension. There were no significant differences between the hemodialysis patients and controls in 2D echocardiographic parameters, including ejection fraction and biochemical parameters except low-density lipoprotein, high-density lipoprotein and c- reactive protein. Despite having lower body mass index, EFT levels were significantly higher in hemodialysis patients compared to the controls (8.0 ± 2.2 mm vs. 5.8 ± 1.9 mm; p < 0.01). In multivariate linear regression analysis we determined that hemodialysis patient status was found to be an independent predictor for both EFT (β = 0. 700, p = 0.014) and carotid intima-media thickness (CIMT, β = 0. 614, p = 0.047). CONCLUSIONS Hemodialysis patients are independently associated with high EFT and CIMT.

The protective effect of prophylactic ozone administration against retinal ischemia-reperfusion injury.

Abstract: Introduction: Retinal ischemia-reperfusion (IR) injury is associated with many ocular diseases. Retinal IR injury leads to the death of retinal ganglion cells (RGCs), loss of retinal function and ultimately vision loss. The aim of this study was to show the protective effects of prophylactic ozone administration against retinal IR injury.Materials and methods: A sham group (S) (n = 7) was administered physiological saline (PS) intraperitoneally (i.p.) for 7 d. An ischemia reperfusion (IR) group (n = 7) was subjected to retinal ischemia followed by reperfusion for 2 h. An ozone group (O) (n = 7) was administered 1 mg/kg of ozone i.p. for 7 d. In the ozone + IR (O + IR) group (n = 7), 1 mg/kg of ozone was administered i.p. for 7 d before the IR procedure and at 8 d, the IR injury was created (as in IR group). The rats were anesthetized after second hour of reperfusion and their intracardiac blood was drawn completely and they were sacrificed. Blood samples were sent to a laboratory for analysis of s...

Gold Electrodes Modified with Calix[4]arene for Electrochemical Determination of Dopamine in the Presence of Selected Neurotransmitters

Abstract: Here, we present an electrochemical sensor based on gold electrodes modified with calix[4]arene functionalized with carboxypiperidino groups at the upper rim. It has been demonstrated that these groups are involved in a complex formation with dopamine (DA) on the surface of gold electrodes. The supramolecular complex calix[4]arene–DA created on the gold electrode surface has been characterized electrochemically and the measuring conditions have been optimized. The presented sensor displayed a detection limit in the pM range. The DA determination was performed successfully in the presence of ascorbic acid, uric acid and selected neurotransmitters.

A calix[4]arene derivative-doped perchlorate-selective membrane electrodes with/without multi-walled carbon nanotubes

Abstract: In this study, poly (vinyl chloride)(PVC) membrane electrodes with/without multi-walled carbon nanotubes (MWCNTs) based on a calix[4]arene derivative for perchlorate ion were described. The influence of membrane composition, pH, conditioning solution on the potentiometric response of the electrodes was investigated. Perchlorate-selective PVC membrane electrode exhibited a slope of 47.8 ± 0.6 mV/pClO4 in the range of 1.0 × 10−7–1.0 × 10−1 mol L−1at pH 4.0 while the coated Pt electrodes with MWCNT-OH, MWCNT-COOH and MWCNT displayed slopes of 46.1 ± 0.7 mV/pClO4 (5.0 × 10−6–1.0 × 10−1 mol L−1), 50.4 ± 1.9 mV/pClO4 (1.0 × 10−6–1.0 × 10−1 mol L−1) and 44.4 ± 0.3 mV/pClO4 (1.0 × 10−5–1.0 × 10−1 mol L−1), respectively. Other response characteristics of these electrodes such as response time, lifetime and detection limit were identified, and the selectivity coefficients towards various anions were calculated by separate solution method. Moreover, the perchlorate-selective electrodes described here were successfully used as an indicator electrode for the determination of perchlorate in real samples such as tap water, river water and human urine by direct calibration method.

Note to: a mathematical model and ant colony algorithm for multi-manned assembly line balancing problem

Abstract: Some feasible mathematical model solution results in a recent paper (Fattahi et al., Int J Adv Manuf Technol, 53:363–378, 2011) are incorrect. In this note, we show by counterexamples that the results are incorrect and mathematical formulation is corrected by additional constraints.

Synthesis of asymmetrical tridendate Schiff bases and metal complexes and investigation of anticarcinogen effects on human colon and cervical cancers

Abstract: The metal complexes of Zn(II), Ni(II), Cu(II) and Pb(II) with asymmetrical Schiff bases were synthesized. The asymmetrical Schiff base was obtained through the condensation of 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde and biphenyl-4-carbaldehyde. The new Schiff base ligands (L1' and L2') and their metal complexes were characterized by TG/DTG, FT-IR, 1H-NMR, UV–Vis, ESR, powder XRD, elemental analysis, magnetic moment and fluorescence studies. The powder XRD studies indicate that Co(II) and Cu(II) complexes are amorphous, while Ni(II) and Zn(II) complexes are crystalline. The anticarcinogenic effects of L1' and L2' were also investigated against colon (SW-620) and cervical cancer (HeLa) cell lines and compound L2' was found to possess the highest anticarcinogenic potential, with 16.7 µM and 27.5 µM of IC50 values for HeLa and SW620 cells, respectively.

Chinese postman problem approach for a large-scale conventional rail network in Turkey

Abstract: Original scientific paper Every year, railways are inspected periodically to examine the status of rail tracks and ensure the safety of train operations of the railroad networks in Turkey. These inspection projects must be performed by several specialized machines with large and expensive equipment. Finding the optimum route of inspection machines that control through travelling all lines is critically important in terms of cost and distance. In current practice, determining the route of these machines is largerly manual and primarily relies on the knowledge and judgment of experts. This paper proposes Chinese Postman Problem (CPP) to solve the inspection machine routing problem. The objective is to minimize the total travel distance on the railroads by finding the shortest route. The proposed model is applied to a large-scale real world problem. Compared to the current practice the proposed approach significantly outperforms the reduced objective value by 20,76%.

Öğretmen Adaylarının Öğrenme Öğretme Anlayışları Ve Fen Öğretimine Yönelik Özyeterlik İnançları

Abstract: Bu arastirmanin amaci, ogretmen adaylarinin ogrenme ogretme anlayislari ve fen ogretimine yonelik oz-yeterlik inanclari arasindaki iliskiyi incelemektir. Arastirmanin calisma grubunu 2013-2014 akademik yili bahar doneminde Bati Karadeniz Bolgesi’nde yer alan bir universitenin egitim fakultesi sinif ve fen bilgisi ogretmenligi anabilim dallari ucuncu ve dorduncu siniflarinda ogrenim goren toplam 423 (326 kiz, 97 erkek) ogretmen adayi olusturmaktadir. Veri toplama araci olarak ogretmen adaylarinin fen ogretimine yonelik oz-yeterlik inanclarini olcmek amaciyla Riggs ve Enochs (1990) tarafindan gelistirilen ve Hazir Bikmaz (2002) tarafindan Turkce uyarlamasi yapilan fen ogretiminde oz-yeterlik inanci olcegi kullanilmistir. Ogretmen adaylarinin ogrenme ogretme anlayislarini belirlemek amaciyla Chan ve Elliott * (2004) tarafindan gelistirilen ve Aypay (2011) tarafindan Turk kulturune uyarlanan ogrenme ogretme anlayisi olcegi kullanilmistir. Bu arastirmanin modelini iliskisel tarama modeli olusturmaktadir. Elde edilen bulgulara gore ogretmen adaylarinin geleneksel ogrenme ogretme anlayisi puanlarinin cinsiyete gore, yapilandirmaci ogrenme ogretme anlayisi ve fen ogretimine yonelik oz-yeterlik inanci puanlarinin anabilim dallarina gore anlamli farklilik gosterdigi sonucuna ulasilmistir. Ayrica geleneksel ogrenme ogretme anlayisi ile kisisel fen ogretimine yonelik oz-yeterlik inanci arasinda negatif ve anlamli, yapilandirmaci ogrenme ogretme anlayisi puanlari ile kisisel fen ogretimine yonelik oz-yeterlik inanci puanlari arasinda pozitif ve anlamli iliski bulunmustur.

Erratum to: Note to: a mathematical model and ant colony algorithm for multi-manned assembly line balancing problem

Abstract: The online version of the original article can be found at doi: 10.1007/s00170-016-9223-y .

Helal Otelleri Tercih Eden Turistlerin Yiyecek İçecek Hizmetlerinden Beklentileri ve Memnuniyet Düzeyleri

Abstract: Gunumuzde tum cagdas ve dinamik toplumlarin ayrilmaz bir parcasi ve zorunlu bir ihtiyaci haline gelmis olan turizm hareketleri, dini hassasiyeti yuksek bireyler acisindan da son derece degerlidir. Dini hassasiyeti seyahatlerinde ve tatillerinde yasamak isteyen bireylerin talepleri dogrultusunda ortaya cikan helal turizm kavrami ise son yillarda tum dunyada gelismektedir. Helal turizm kapsaminda mevcut potansiyelin taleplerine cevap verebilecek yapidaki pek cok isletme gunumuzde faaliyet gostermektedir. Soz konusu isletmelerde misafirlerin ibadetlerini yerine getirebilme imkanini saglayan alanlar, kadin-erkek turistlere ayri aktivite alanlari, Islami kurallara uygun kiyafetlerle aileler tarafindan kullanilabilen karma plajlar oldugu gibi yalnizca kadin ve erkeklerin kullanimina ayrilmis plaj alanlari gibi pek cok etkinlik alanlari bulunmaktadir. Diger yandan konaklama etkinliklerinin tamamlayicisi olan helal yiyecek-icecek servisi de son yillarda ozellikle agirlik verilen konulardan biri haline gelmeye baslamistir. Ozellikle, helal otelleri tercih eden turistlerin, otel bunyesinde faaliyet gosteren yiyecek icecek hizmetleri servisinden beklentilerinin neler oldugunun ortaya cikartilmasi ve bireylerin isletmelerden beklentilerinin analiz edilmesi son derece degerlidir. Bu calisma, helal otelleri tercih eden turistlerin yiyecek icecek hizmetleri servisinden beklentileri ve memnuniyet durumlarini ortaya cikarmak icin hazirlanmistir.