Screening of the antioxidant properties of olive (Olea europaea) leaf extract by titanium based reduced graphene oxide electrode

Sibel Yazar,Ebru Kurtulbaş,Sinem Ortaboy,Gülten Atun,Selin Şahin 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.7

Olive leaves were extracted with homogenizer-assisted extraction (HAE). Box-Behnken (BBN) design was employed through response surface approach (RSA) to achieve the optimum conditions. Bioactivity of the extract was assessed by its oleuropein, total biophenol (TBC) and total flavonoid (TFC) content along with its antioxidant activity determined by DPPH and CUPRAC assays. A new nanocomposite was developed using reduced graphene oxide (rGO) modified with TiOx (Ti-rGO) for trace amount determination of oleuropein in olive leaf extract. Structural characterization of the electrode was clarified using atomic force microscopy (AFM) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) techniques. Cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques were performed to investigate electrochemical behavior of oleuropein using three electrode configurations. Results of CV and SWV showed that quasi-reversible reaction occurred on electrode/electrolyte interface and a linear concentration range of 5-30 nM was obtained with a detection limit of 0.57 nM for oleuropein.

Dicationic poly(4-vinyl pyridinium) ionic liquid capsules as template for Co nanoparticle preparation and H2 production from hydrolysis of NaBH4

Nurettin Sahiner,Alper O. Yasar,Nahit Aktas 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.23 No.-

Poly(4-vinyl pyridine)-silica (p(4-VP)-silica) composites were synthesized via micro emulsion polymerization, and the capsule of p(4-vinyl pyridine), as cap-p(4-VP), was prepared by removing the core silica from p(4-VP)-silica composites by HF treatment. Dicationic particles in the form of cappoly( 4-vinyl pyridine)++-1,4-butane (cap-p(4-VP)++-C4), capsule-poly(4-vinyl pyridine)++-1,6-hexane (cap-p(4-VP)++-C6), and capsule-poly(4-vinyl pyridine)++-1,8-octane (cap-p(4-VP)++-C8) were prepared by modifying cap-p(4-VP) particles with corresponding dibromo alkanes. Then, polymer–metal composites were also prepared from cap-p(4-VP) and dicationic cap-p(4-VP) particles by loading CoCl2 from ethanol and the obtained composites were used in H2 generation from hydrolysis of NaBH4, and The Ea for the composite catalyst was calculated as 56.53 kJ/mol.

Nosocomial oral myiasis by Sarcophaga sp. In Turkey

Suleyman Yazar,Bilal Dik,Saban Yalcin,Funda Demirtas,Ozan Yaman,Mustafa Ozturk,Izzet Sahin 연세대학교의과대학 2005 Yonsei medical journal Vol.46 No.3

We present a case of oral myiasis in a 15-year-old boy with tuberculosis meningitis. The diagnosis was based on the visual presence of wriggling larvae about 1 cm in size and on the microscopic features of the maggots, especially those relating to stigmatic structures. The larvae were identified as thirdstage larvae of Sarcophaga sp.

Percutaneous Management of Ureteral Injuries that are Diagnosed Late After Cesarean Section

Bahri Ustunsoz,Sahin Ugurel,Namik Kemal Duru,Yasar Ozgok,Ayfer Ustunsoz 대한영상의학회 2008 Korean Journal of Radiology Vol.9 No.4

Objective: We wanted to present the results of percutaneous management of ureteral injuries that were diagnosed late after cesarean sections (CS). Materials and Methods: Twenty-two cases with 24 ureteral injuries that were diagnosed late after CS underwent percutaneous nephrostomy (PN), antegrade double J (DJ) catheter placement and balloon dilatation or a combination of these. The time for making the diagnosis was 21 50.1 days. The injury site was the distal ureter in all cases (the left ureter: 13, the right ureter: 7 and bilateral: 2). Fifteen complete ureteral obstructions were detected in 13 cases. Ureteral leakage due to partial (n = 4) or complete (n = 3) rupture was noted in seven cases. Two cases had ureterovaginal fistula. All the cases were initially confirmed with antegrade pyelography and afterwards they underwent percutaneous nephrostomy. Balloon dilatation was needed in three cases. Antegrade DJ stents were placed in 10 cases, including the three cases with balloon dilatation. Repetititon of percutaneous nephrostomy with balloon dilatation and DJ stent placement was needed in one case with complete obstruction. All the cases were followed-up with US in their first week and then monthly thereafter for up to two years. Results: Eighteen ureters (75%) were managed by percutaneous procedures alone. A total of six ureter injuries had to undergo surgery (25%). Conclusion: Percutaneous management is a good alternative for the treatment of post-CS ureteral injuries that are diagnosed late after CS. Percutaneous management is at least preparatory for a quarter of the cases where surgery is unavoidable. Objective: We wanted to present the results of percutaneous management of ureteral injuries that were diagnosed late after cesarean sections (CS). Materials and Methods: Twenty-two cases with 24 ureteral injuries that were diagnosed late after CS underwent percutaneous nephrostomy (PN), antegrade double J (DJ) catheter placement and balloon dilatation or a combination of these. The time for making the diagnosis was 21 50.1 days. The injury site was the distal ureter in all cases (the left ureter: 13, the right ureter: 7 and bilateral: 2). Fifteen complete ureteral obstructions were detected in 13 cases. Ureteral leakage due to partial (n = 4) or complete (n = 3) rupture was noted in seven cases. Two cases had ureterovaginal fistula. All the cases were initially confirmed with antegrade pyelography and afterwards they underwent percutaneous nephrostomy. Balloon dilatation was needed in three cases. Antegrade DJ stents were placed in 10 cases, including the three cases with balloon dilatation. Repetititon of percutaneous nephrostomy with balloon dilatation and DJ stent placement was needed in one case with complete obstruction. All the cases were followed-up with US in their first week and then monthly thereafter for up to two years. Results: Eighteen ureters (75%) were managed by percutaneous procedures alone. A total of six ureter injuries had to undergo surgery (25%). Conclusion: Percutaneous management is a good alternative for the treatment of post-CS ureteral injuries that are diagnosed late after CS. Percutaneous management is at least preparatory for a quarter of the cases where surgery is unavoidable.

Effects of Dexmedetomidine Infusion During Sevoflurane Anesthesia on Otoacoustic Emissions

Mehmet İlhan Şahin,Alperen Vural,Aynur Akın,İbrahim Ketenci,Yaşar Ünlü 대한청각학회 2019 Journal of Audiology & Otology Vol.23 No.2

Background and Objectives: Knowing the ototoxic potential of the agents used in medical treatments is important for the protection of hearing. Although we have knowledge regarding some effects of dexmedetomidine, which is an anesthetic-sparing drug, its influence over the hearing system has never been studied and is obscure yet. The aim of this study is to determine the effects of intravenous dexmedetomidine application during sevoflurane anesthesia on otoacoustic emissions (OAEs). Subjects and Methods: This prospective randomized study was performed on 60 patients (34 male, 26 female, mean age: 30.6±9.2 years) who were scheduled for an elective surgery under general anesthesia and the patients were enrolled and randomly divided into 2 groups. They received dexmedetomidine (Group D) or Saline (Group S) infusion during a standardized Sevoflurane anesthesia. Transient and distortion product OAEs were measured preoperatively and postoperatively (24th hour). OAE results were compared within and between groups. Results: In group D postoperative OAEs were lower than preoperative OAEs and postoperative levels of group S, especially at low frequencies (p<0.05). Conclusions: Dexmedetomidine infusion affects the micromechanical function of cochlea especially in the low-frequency region. Dexmedetomidine should be carefully used during general anesthesia to avoid its probable harmful effects on cochlear micromechanics.

Premedication Methods in Nasal Endoscopy: A Prospective, Randomized, Double-Blind Study

Mehmet İlhan Şahin,Kerem Kökoğlu,Şafak Güleç,İbrahim Ketenci,Yaşar Ünlü 대한이비인후과학회 2017 Clinical and Experimental Otorhinolaryngology Vol.10 No.2

Objectives. To identify the optimal pharmacological method of preparing patients for nasal endoscopy. Methods. Twenty healthy volunteers were enrolled in this prospective, randomized, double-blind study. Four types of medications were applied in their nostrils with binary combinations of spray bottles on four different days in a random order: placebo (normal saline [NS]+NS), decongestant (NS+oxymetazoline), anesthetic (NS+lidocaine), and decongestant plus anesthetic (oxymetazoline+lidocaine). Rigid nasal endoscopy was performed 10 minutes after spray application. The volunteers evaluated the discomfort caused by each spray application, and nasal pain scores due to the passage of the endoscope. The physicians quantified nasal decongestion using a visual analogue scale. Endoscopy duration as well as pulse and mean blood pressure (MBP) before spray application, 10 minutes after the application, and immediately after endoscopic examination were also recorded. Results. The discomfort caused by lidocaine was significantly higher than that caused by the other sprays (P<0.001). The lowest pain score related to endoscopy was obtained for oxymetazoline+lidocaine (P<0.001). Nasal decongestion was best achieved with NS+oxymetazoline (P<0.001). Endoscopy duration was the shortest for oxymetazoline+lidocaine (P<0.05). Statistically significant MBP changes were only seen with the application of NS+oxymetazoline (P<0.05). However, neither MBP nor pulse rate change was significant clinically. Conclusion. Application of decongestant and anesthetic sprays together seems to be the best method of pharmacological preparation of patients for nasal endoscopy.

Investigation of Thiol/Disulfide Balance in Obese Rats with Non-Alcoholic Fatty Liver Disease

Tursun, Serkan,Gulerman, Hacer Fulya,Gazyagci, Serkal,Sahin, Yasar,Erel, Ozcan,Neselioglu, Salim The Korean Society of Pediatric Gastroenterology 2021 Pediatric gastroenterology, hepatology & nutrition Vol.24 No.5

Purpose: Due to the increasing prevalence of obesity worldwide, non-alcoholic fatty liver disease (NAFLD) has reached epidemic dimensions over time. NAFLD is the most common cause of childhood chronic liver disease. There is a relationship between NAFLD and oxidative stress. This study aims to investigate the changes in thiol/disulfide homeostasis parameters to determine the oxidant/antioxidant balance in obese rats with diet-induced NAFLD and healthy rats. Methods: Twelve Wistar albino rats were used in this study. Experimentally produced NAFLD obese rats (n=6) and healthy rats were compared. Experimental NAFLD model was created with a special fatty liver diet (Altromin^® C1063, Fatty Liver Diet, Exclusivet, Lage, Germany). The biochemical and histopathological features of the groups, as well as serum thiol/disulfide homeostasis parameters, were analyzed and compared. Results: In the experimentally induced NAFLD rat model, they gained more weight than the control group. Steatosis (at least grade 2) occurred in all rats fed with special fatty liver diet for 12 weeks. Histopathologically, no high-grade inflammation was observed in rats with experimental NAFLD after feeding a diet for 12 weeks. Results revealed that aspartate transaminase and alanine transaminase levels were high, albumin levels were low, oxidant stress parameters increased, and antioxidant thiol groups decreased. Conclusion: Experimental NAFLD is characterized by increased oxidant stress accompanying fatty tissue in the liver. Analysis of thiol/disulfide homeostasis parameters in NAFLD can be used in further studies to develop effective treatment options.

Biometrical Variation of Posidonia oceanica with Different Bottom Types Along the Entire Turkish Mediterranean Coast

Mutlu Erhan,Duman Güler Sıla,Karaca Doğukan,Özvarol Yaşar,Şahin Ahmet 한국해양과학기술원 2023 Ocean science journal Vol.58 No.1

The biometrical dynamics of Posidonia oceanica were studied with regard to variation and its depthwise extension with four major bottom types along the entire Turkish Mediterranean coasts in winter and summer during 2019. The bottom type which mainly consisted of rock, matte (hard bottom), sand, and mud (soft bottom) was a key determinant for biometrical (density and morphometric) changes which were more prominent in summer. The upper and lower limits of vertical depthwise extension of the meadows were restricted by the zonal distribution of the hard bottom. The limits were not restricted on the soft bottom. However, some large areas of the soft bottoms were devoid of the meadows depending on the existence of mobile substrate affected by the high dynamic of water movement. The density variables were higher on hard bottoms than on the soft bottoms; the inter-nodal distance was longer on matte than on rock, sand, and mud, in contrast to leaf biomass. Mud had the lowest number of leaves per shoot and shoot density, whereas rock had the highest number. The shortest rhizome was measured on the rock, while the longest rhizome was measured on matte, which also had the longest leaves. The soft bottoms had wider leaves than the hard bottoms had. Besides the seasonal and depthwise differences in the biometrics, the biometrics were separately assembled between rock and mud. Contrary to the morphometric variables, the density biometrics decreased linearly from the hard bottom to the soft bottom.

Chemopreventive Effects of Hydatid Disease on Experimental Breast Cancer

Altun, Ahmet,Saraydin, Serpil Unver,Soylu, Sinan,Inan, Deniz Sahin,Yasti, Cinar,Ozdenkaya, Yasar,Koksal, Binnur,Duger, Cevdet,Isbir, Cemil,Turan, Mustafa Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4

Breast cancer is one of the most common and letal cancers in all over the world. Since there have been significant improvements in treatment of breast cancer, there is still a big need for alternative approaches. In this study, we aimed to investigate protective role of hydatid disease against breast cancer. Twenty Wistar rats were divided into two groups of 10 rats each Group I (control) and Group II. In Group II intraperitoneal hydatidosis was performed. Then DMBA was applied to mammary tissues of all rats. Immunohistochemistry studies for Ki-67 and S-100 in the tumoral tissue sections of DMBA induced mammary tumor in rats were performed. TUNEL Assay was used to detect apoptotic cells of tumoral tissue. In vivo anticancer activity testing was carried out by preventing the tumorigenesis by DMBA in mammary tissue of rats. The expressions of the Ki-67 and S-100 protein decreased in rats who had Hydatid Disease (HD) (Group II), compared with the control rats (Group I). TUNEL positive cells were higher in rats with HD (Group II), compared with the control rats (Group I). In vivo studies showed that HD prevented the tumorigenesis by DMBA in mammary tissue of rats with 50 percent.In the light of the evidence the present study showed that HD may have chemopreventive effects on DMBA induced breast cancer.

Retrospective Analysis of 498 Primary Soft Tissue Sarcomas in a Single Turkish Centre

Duman, Berna Bozkurt,Gunaldi, Meral,Ercolak, Vehbi,Afsar, Cigdem Usul,Sahin, Berksoy,Erkisi, I. Melek Koksal,Kara, Oguz,Paydas, Semra,Gonlusen, Gulfiliz,Sertdemir, Yasar Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Background: Soft tissue sarcomas (STS) must be managed with a team involving pathologists, radiologists, surgeons, radiation therapists and medical oncologists. Treatment modalities and demographic charasteristics of Turkish STS were analysed in the current study. Material-Methods: Primary adult STS followed between 1999-2010 in Cukurova University Medical Faculty Department of Medical Oncology were analzied retrospectively Results: Of the total of 498 patients, 238 were male and 260 female. The most seen adult sarcomas were leomyosarcoma (23%). Localization of disease was upper extremity (8.8%), lower extremity (24.7%), head-neck 8.2%, thoracic 8%, retroperitoneal 5.6%, uterine 12.4%, abdominal 10%, pelvic region 3.6 and other regions 10%. Some 13.1% were early stage, 10.2% locally advanced, 8.2% metastatic and 12.2% recurrent disease. Patients were treated with neoadjuvant/adjuvant (12%) or palliative chemotherapy (7.2%) and 11.4% patients did not receive chemotherapy. Surgery was performed as radical or conservative. The most preferred regimen was MAID combination chemotherapy in the rate of 17.6%. The most common metastatic site was lung (18.1%). The overall survival was 45 months (95%CI 30-59), 36 months in men and 55 months in women, with no statistically significant difference (p=0.5). The survival rates were not different between the group of adjuvant and palliative chemotherapy (respectively 28 versus 18 months) (p=0.06), but radical surgery at 37 months was better than 22 months for conservative surgery (p=0.0001). No differences were evident for localization (p=0.152). Locally advanced group had higher overall survival rates (72 months) than other stages (p=0.0001). Conclusion: STS can be treated successfully with surgery, chemotherapy and radiotherapy. The survival rates of Turkish people were higher in locally advanced group; these results show the importance of multimodality treatment approach and radical surgery.