The effects of ventilation with high density oxygen on the strength of gastrointestinal anastomosis

Tevfik Eker,Volkan Genc,Yusuf Sevim,Ozge Cumaogullari,Menekse Ozcelik,Akin Firat Kocaay,Cemal Ozben Ensari,Ozge Tugce Pasaoglu 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.89 No.1

Purpose: The aim of our study is to evaluate the effects of administration of perioperative supplemental oxygen on anastomoses. Methods: Forty male Wistar albino rats were used in the study and randomized into 4 groups. Ischemia-reperfusion models were built in groups 3 and 4. Jejunojejunostomy was performed in all rats and assigned to an oxygen/nitrous oxide mixture with a fraction of inspired oxygen of 30% in groups 1 and 3 and 80% in groups 2 and 4. The measurements of perianastomotic tissue oxygen pressure, bursting pressure, level of hydroxyproline were evaluated and compared in all groups. Results: The perianastomotic tissue oxygen pressures, bursting pressures and levels of hydroxyproline were identified as significantly high in groups 2 and 4, administered a fraction of inspired oxygen of 80%, compared to groups 1 and 3, administered a fraction of inspired oxygen of 30%. Conclusion: Perioperative supplemental oxygen contributes positively to the anastomotic healing.

Mid-length Pedicle Screws in Posterior Instrumentation of Scoliosis

Tevfik Balikci,Görkem Kıyak,Ahmed Majid Heydar,Motasim Khalid Bawaneh,Murat Bezer 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.5

Study Design: Prospective analysis of collected data. Purpose: We determine the need for the use of mid-length pedicle screws (screws with 2.5-mm long increments) during posterior spinal instrumentation. Overview of Literature: Many biomechanical studies have been performed showing that increasing the pedicle screw insertion depth provides an improved resistance to pullout, cyclic loading, and derotational forces, but no intermediate length screws were used. Methods: We prospectively evaluated 120 patients who received posterior segmental instrumentation for structural scoliosis. Preoperatively, 91.44-cm long cassette anteroposterior (AP), lateral, and AP bending radiographs and multiplanar computed tomography were performed in all patients routinely. We measured chord length to determine the maximum probable screw length of all vertebrae. All pedicle screws were attempted to be placed as long as possible. The main intention was at least to engage the subcortical bone of the anterior vertebral cortex. Especially in the apical region, the screws were attempted to be inserted bicortically. The length, level, region, and side of each screw were recorded. Screws with 5-mm increments were called standard length screws (SLS), and middle-sized screws with 2.5-mm increments were called mid-length screws (MLS). Results: Of 2,846 pedicle screws inserted, 1,575 (55.4%) were SLS and 1,271 (44.6%) were MLS, demonstrating a need for MLS in scoliosis surgery (p<0.05). The need for MLS increased significantly in the thoracic region, apical vertebrae, and convex side (p<0.05). Conclusions: If anterior cortex engagement or longer placement of pedicle screws is intended during scoliosis surgery, for safer placement, screws with 2.5-mm increments should be available in posterior instrumentation systems.

Comparision of Nd: YAG Capsulotomy Rate with Viscoimplantation and Hydroimplantation Intraocular Lens Techniqu

tevfik oğurel,Reyhan Oğurel,Nesrin Büyüktortop Gök,Zafer Onaran,Nurgül Örnek,Kemal Örnek 대한안과학회 2019 Korean Journal of Ophthalmology Vol.33 No.3

Purpose: To investigate the rate of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy inthe hydroimplantation intraocular lens (IOL) technique. Methods: This retrospective study was comprised of 6,192 eyes in 3,790 patients who underwent surgery fromJanuary 2013 to September 2017 and then were followed up for at least 1 year. The eyes of these patientswere divided into two groups: either viscoimplantation or hydroimplantation. The follow-up examinations werecarried out on the 1st day, 4th day, 1st month, and 3 months to 1 year postoperatively. The Nd:YAG capsulotomyrates were evaluated by the different IOL implantation techniques and IOL materials. Results: The mean follow-up duration of the patients was in the viscoimplantation group 14.85 ± 2.43 and 15.05± 1.93 months in the hydroimplantation group. The Nd:YAG capsulotomy rate was significantly lower in thehydroimplantation group compared with the viscoimplantation group for the entire hydrophilic IOL model (p <0.001). In addition, the Nd:YAG rate was lower in the hydroimplantation group that used a hydrophilic IOL thanit was in the viscoimplantation group, which used a hydrophobic IOL. Conclusions: The hydroimplantation technique reduced the Nd:YAG capsulotomy rate.

Antioxidant Properties of Urtica pilulifera Root, Seed, Flower, and Leaf Extract

Tevfik Özen,Zeynep Collu,Halil Korkmaz 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.5

This study was conducted to evaluate the antioxidative properties of hydroalcoholic (80%) extracts from different parts of Urtica pilulifera L. (Family Urticaceae), including leaf (UPL), flower (UPF), seed (UPS), and root (UPR). Antioxidative activity of the extracts was measured using the ferric thiocyanate method, thiobarbituric acid method, reductive potential, metal chelating, free radical, superoxide anion radical, and hydrogen peroxide scavenging activity. In addition, the results were compared with antioxidants such as tert-butylated hydroxyanisole (BHA), tert-butylated hydroxytoluene (BHT), and α-tocopherol. Total antioxidant activities of UPS, UPF, UPL, UPR, BHA, BHT, and α-tocopherol were 88.79%, 85.13%, 86.72%, 78.46%, 81.31%, 76.12%, and 46.28%, respectively. Like the antioxidant activity, the reducing power and the superoxide anion radical and free radical scavenging activities of UPL, UPF, UPS, and UPR are concentration dependent. A correlation between higher antioxidant activity and the amount of total phenolics was found in the extracts.

A characterization of the unit group in $\mathbb{Z}[T \times C_2]$

Tevfik Bilgin,Omer Kusmus,Richard M. Low 대한수학회 2016 대한수학회보 Vol.53 No.4

Describing the group of units $U(\mathbb{Z}G)$ of the integral group ring $\mathbb{Z}G$, for a finite group $G$, is a classical and open problem. In this note, we show that $U_1(\mathbb{Z}[T \times C_2]) \cong [F_{97} \rtimes F_5] \rtimes [T \times C_2]$, where $T = \langle a, b: a^6 = 1, a^3 = b^2, ba = a^5b \rangle$ and $F_{97}$, $F_5$ are free groups of ranks 97 and 5, respectively.

A Study of Oxidative Stress Parameters in Anti-Helicobacter Pylorus Immunoglobulin G Positive and Negative Gastric Cancer Patients

Tevfik Noyan,Hüseyin Guducuoglu,Mahmut Ilhan 연세대학교의과대학 2009 Yonsei medical journal Vol.50 No.5

Purpose: Helicobacter pylorus (HP) is a Gram-negative spiral-shaped microaerophilic bacterium, which colonizes in the gastric mucosa of humans. The gastric human pathogen HP causes chronic gastritis and ulcers, and has a strong relationship with gastric cancer. The aim of this study was to determine advanced oxidation protein products (AOPP) levels, activities of myeloperoxidase (MPO) and catalase (CAT) in two groups. Materials and Methods: For this aim, one group included 30 patients with gastric cancer (Group 1) and the other included 30 subjects with non-gastric cancer and Anti-HP immunoglobulin (Ig) G antibody positive (group 2). Anti-HP IgG antibody test values were found as positive in fifty percent of group 1 and all of the group 2 patients. Results: Significantly increased AOOP levels were found in group 1 (p < 0.05) compared to group 2. There were no significant differences between the groups in regard to activities of MPO and CAT. In addition, AOPP level, MPO and CAT activities were similar among the Anti-HP IgG positive and negative subgroups of group 1 patients. Conclusion: The result of this study indicated that gastric cancer patients were characterized by increased protein oxidation, whereas there was no significant difference in oxidative stress parameters and antioxidant enzyme activity between the Anti-HP IgG positive and negative gastric cancer patients. Purpose: Helicobacter pylorus (HP) is a Gram-negative spiral-shaped microaerophilic bacterium, which colonizes in the gastric mucosa of humans. The gastric human pathogen HP causes chronic gastritis and ulcers, and has a strong relationship with gastric cancer. The aim of this study was to determine advanced oxidation protein products (AOPP) levels, activities of myeloperoxidase (MPO) and catalase (CAT) in two groups. Materials and Methods: For this aim, one group included 30 patients with gastric cancer (Group 1) and the other included 30 subjects with non-gastric cancer and Anti-HP immunoglobulin (Ig) G antibody positive (group 2). Anti-HP IgG antibody test values were found as positive in fifty percent of group 1 and all of the group 2 patients. Results: Significantly increased AOOP levels were found in group 1 (p < 0.05) compared to group 2. There were no significant differences between the groups in regard to activities of MPO and CAT. In addition, AOPP level, MPO and CAT activities were similar among the Anti-HP IgG positive and negative subgroups of group 1 patients. Conclusion: The result of this study indicated that gastric cancer patients were characterized by increased protein oxidation, whereas there was no significant difference in oxidative stress parameters and antioxidant enzyme activity between the Anti-HP IgG positive and negative gastric cancer patients.

CHARACTERIZATION OF CENTRAL UNITS OF ZAn

Tevfik Bilgin,Necat Gorentas,I. Gokhan Kelebek 대한수학회 2010 대한수학회지 Vol.47 No.6

The structure of V (Z(ZAn)) is known when n ≤ 6. If n = 5or 6, then a complete set of generators of V (Z(ZAn)) has been deter-mined. In this study, it was shown that V (Z(ZAn)) is trivial when n = 7; 8 or 9 and it is generated by a single unit u when n = 10 or 11: This unit u is characterized explicitly for n = 10 or 11 by using irreducible characters of An.

The effect of silane applied to glass ceramics on surface structure and bonding strength at different temperatures

Tevfik Yavuz,Oguz Eraslan 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.2

PURPOSE To evaluate the effect of various surface treatments on the surface structure and shear bond strength (SBS) of different ceramics. MATERIALS AND METHODS 288 specimens (lithium-disilicate, leucite-reinforced, and glass infiltrated zirconia) were first divided into two groups according to the resin cement used, and were later divided into four groups according to the given surface treatments: G1 (hydrofluoric acid (HF)+silane), G2 (silane alone-no heat-treatment), G3 (silane alone-then dried with 60℃ heat-treatment), and G4 (silane alone-then dried with 100℃ heat-treatment). Two different adhesive luting systems were applied onto the ceramic discs in all groups. SBS (in MPa) was calculated from the failure load per bonded area (in N/mm2). Subsequently, one specimen from each group was prepared for SEM evaluation of the separated-resin–ceramic interface. RESULTS SBS values of G1 were significantly higher than those of the other groups in the lithium disilicate ceramic and leucite reinforced ceramic, and the SBS values of G4 and G1 were significantly higher than those of G2 and G3 in glass infiltrated zirconia. The three-way ANOVA revealed that the SBS values were significantly affected by the type of resin cement (P<.001). FIN ceramics had the highest rate of cohesive failure on the ceramic surfaces than other ceramic groups. AFM images showed that the surface treatment groups exhibited similar topographies, except the group treated with HF. CONCLUSION The heat treatment was not sufficient to achieve high SBS values as compared with HF acid etching. The surface topography of ceramics was affected by surface treatments.

Does Blood Flow Change according to Mood? Blood Rheology in Bipolar Disorder

Tevfik Kalelioglu,Murat Kocabiyik,Burcu Kok,Pelin Unalan,Sule Sozen,Ozge Yuksel,Nesrin Karamustafalioglu 대한정신약물학회 2018 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.16 No.3

Objective: Bipolar disorder (BD) is associated with increased rates of cardiovascular diseases. There is growing evidence that blood viscosity may have a common role, correlated with well-known major risk factors that promote cardiovascular disease. In this study we aimed to investigate the whole blood viscosity (WBV) in different stages of BD. Methods: A total of 121 bipolar patients and 41 age-gender matched healthy controls were included. Forty-four of bipolar patients were in manic, 35 were depressed and 42 were in euthymic state. WBV was calculated from hematocrit and total plasma protein according to Simone’s formula at low and high shear rates (LSR and HSR). Results: WBV at HSR of manic group was 16.91±1.01, depressive group was 17.23±0.80, euthymic group was 17.63± 0.95, and control group was 17.52±0.71 (p =0.001). WBV at LSR of manic depressive, euthymic and control group were 53.10±20.58, 60.30±17.02, 68.91±20.33, and 62.01±19.28, respectively (p =0.001). Both WBV at HSR and LSR of manic group was significantly lower than that of the euthymic and control groups (p =0.001 and 0.010 respectively for HSR, p =0.001 and 0.011 respectively for LSR). WBV was significantly positively correlated with lipid profile except high density lipoprotein (HDL). Conclusion: Our results demonstrate a decrement in blood viscosity in manic episode compared with euthymics and controls. Positive correlation of blood viscosity with lipid parameters (except HDL), and negative correlation with number of previous manic episodes suggest that manic episode has favorable effect on cardiovascular risk regarding to blood viscosity.

Conceptual and Procedural Learning in Mathematics

( Isleyen Tevfik ),( Isik Ahmet ) 한국수학교육학회 2003 수학교육연구 Vol.7 No.2