ON TIMELIKE BERTRAND CURVES IN MINKOWSKI 3-SPACE

( Ali Ucum ),( Kazim Ilarslan ) 호남수학회 2016 호남수학학술지 Vol.38 No.3

In this paper, we study the timelike Bertrand curves in Minkowski 3-space. Since the principal normal vector of a timelike curve is spacelike, the Bertrand mate curve of this curve can be a timelike curve, a spacelike curve with spacelike principal normal or a Cartan null curve, respectively. Thus, by considering these three cases, we get the necessary and sufficient conditions for a timelike curve to be a Bertrand curve. Also we give the related examples.

NOTE ON BERTRAND B-PAIRS OF CURVES IN MINKOWSKI 3-SPACE

( Kazim Ilarslan ),( Ali Ucum ),( Nihal Kilic Aslan ),( Emilija Nesovic ) 호남수학회 2018 호남수학학술지 Vol.40 No.3

In this paper, we define null Cartan and pseudo null Bertrand curves in Minkowski space E according to their Bishop frames. We obtain the necessary and sufficient conditions for pseudo null curves to be Bertand B-curves in terms of their Bishop curva-tures. We prove that there are no null Cartan curves in Minkowski 3-space which are Bertrand B-curves, by considering the cases when their Bertrand B-mate curves are spacelike, timelike, null Cartan and pseudo null curves. Finally, we give some examples of pseudo null Bertrand B-curve pairs.

Predictors of Intra-Aortic Balloon Pump Insertion in Coronary Surgery and Mid-Term Results

Kazim Ergüneş,Ismail Yurekli,Ersin Celik,Ufuk Yetkin,Levent Yilik,Ali Gurbuz 대한흉부외과학회 2013 Journal of Chest Surgery (J Chest Surg) Vol.46 No.6

Background: We aimed to investigate the preoperative, operative, and postoperative factors affecting intra-aortic balloon pump (IABP) insertion in patients undergoing isolated on-pump coronary artery bypass grafting (CABG). We also investigated factors affecting morbidity, mortality, and survival in patients with IABP support. Methods: Between January 2002 and December 2009, 1,657 patients underwent isolated CABG in İzmir Katip Celebi University Atatürk Training and Research Hospital. The number of patients requiring support with IABP was 134 (8.1%). Results: In a multivariate logistic regression analysis, prolonged cardiopulmonary bypass time and prolonged operation time were independent predictive factors of IABP insertion. The postoperative mortality rate was 35.8% and 1% in patients with and without IABP support, respectively (p=0.000). Postoperative renal insufficiency, prolonged ventilatory support, and postoperative atrial fibrillation were independent predictive factors of postoperative mortality in patients with IABP support. The mean follow-up time was 38.55±22.70 months and 48.78±25.20 months in patients with and without IABP support, respectively. The follow-up mortality rate was 3% (n=4) and 5.3% (n=78) in patients with and without IABP support, respectively. Conclusion: The patients with IABP support had a higher postoperative mortality rate and a longer length of intensive care unit and hospital stay. The mid-term survival was good for patients surviving the early postoperative period.

Curve Couples and Spacelike Frenet Planes in Minkowski 3-Space

( Ali Ucum ),( Kazim Ilarsilan ),( Siddika Ozkaldi Karakus ) 호남수학회 2014 호남수학학술지 Vol.36 No.3

In this study, we have investigated the possibility of whether any spacelike Frenet plane of a given space curve in Minkowski 3-space E13 also is any spacelike Frenet plane of another space curve in the same space. We have obtained some characterizations of a given space curve by considering nine possible case.

Eugenol-rich Fraction of Syzygium aromaticum (Clove) Reverses Biochemical and Histopathological Changes in Liver Cirrhosis and Inhibits Hepatic Cell Proliferation

Shakir Ali,Amena Mahmood,Indusmita Routray,Tijjani Salihu Shinkafi,Kazim Sahin,Omer Kucuk 대한암예방학회 2014 Journal of cancer prevention Vol.19 No.4

Background:Dried flower bud of Syzygium aromaticum (clove) is rich in eugenol, an antioxidant and antiinflammatory compound thatcan protect liver against injury. Clove, besides eugenol, also contains other pharmacologically active phytochemicals such as β-sitosteroland ascorbic acid. This study reports the effect of eugenol-rich fraction (ERF) of clove on liver cirrhosis induced by thioacetamide. Methods:Cirrhosis of the liver, which predisposes to hepatocellular carcinoma, was induced by administering thioacetamide (0.03%)in drinking water for 16 weeks. Cirrhotic animals were divided into two groups; the treated group was administered ERF for 9 weeks,one week after discontinuation of thioacetamide, while the other group received normal saline for a similar duration of time. Results:The treatment with ERF, as determined by histopathology and through a battery of biochemical markers of hepatic injury, oxidativestress and drug metabolizing enzymes, significantly ameliorated the signs of liver cirrhosis. It lowered the elevated levels ofalkalinephosphatase, γ-glutamyl transferase and other biochemical changes in liver cirrhosis. Histopathology of the liver corroborated the effectof ERF with biochemical findings. ERF treatment further inhibited cell proliferation, as demonstrated by reduced [3H]-thymidine uptake. Conclusions:Data provide evidence supporting the protective action of ERF on liver cirrhosis. The study assumes significance becausecirrhosis predisposes the liver to cancer, which is characterized by abnormal cell proliferation. ERF in this study is reportedto inhibithepatic cell proliferation and at the same time decrease oxidative stress, which might be the mechanism of protection against liver cirrhosis.

Electrical, thermal and spectroscopic studies of Te doped polyaniline

Samrana Kazim,Vazid Ali,M. Zulfequar,M. Mazharul Haq,M. Husain 한국물리학회 2007 Current Applied Physics Vol.7 No.1

In the present paper, we have reported the chemical synthesis and characterization of polyaniline doped with tellurium. The anilinewas polymerized by chemical oxidation using ammonium persulphate as an oxidant and was doped with dierent concentrations of tel-lurium. Doped PANI was characterized by using FTIR, DSC and two-probe conductivity measurement. The dc conductivity has beenmeasured to see the eect of tellurium and its mechanism has been explained by the formation of polarons and bipolarons that movedue to the incorporation of Te into the PANI chain. Glass transition temperature (Tg) and enthalpy (DH) have been calculated fromDSC measurements. FTIR spectra suggest the structural changes after incorporation of Te in polymeric chain.

NOTE ON BERTRAND B-PAIRS OF CURVES IN MINKOWSKI 3-SPACE

Ilarslan, Kazim,Ucum, Ali,Aslan, Nihal Kilic,Nesovic, Emilija The Honam Mathematical Society 2018 호남수학학술지 Vol.40 No.3

In this paper, we define null Cartan and pseudo null Bertrand curves in Minkowski space ${\mathbb{E}}^3_1$ according to their Bishop frames. We obtain the necessary and sufficient conditions for pseudo null curves to be Bertand B-curves in terms of their Bishop curvatures. We prove that there are no null Cartan curves in Minkowski 3-space which are Bertrand B-curves, by considering the cases when their Bertrand B-mate curves are spacelike, timelike, null Cartan and pseudo null curves. Finally, we give some examples of pseudo null Bertrand B-curve pairs.

ON TIMELIKE BERTRAND CURVES IN MINKOWSKI 3-SPACE

Ucum, Ali,Ilarslan, Kazim The Honam Mathematical Society 2016 호남수학학술지 Vol.38 No.3

In this paper, we study the timelike Bertrand curves in Minkowski 3-space. Since the principal normal vector of a timelike curve is spacelike, the Bertrand mate curve of this curve can be a timelike curve, a spacelike curve with spacelike principal normal or a Cartan null curve, respectively. Thus, by considering these three cases, we get the necessary and sufficient conditions for a timelike curve to be a Bertrand curve. Also we give the related examples.

CURVE COUPLES AND SPACELIKE FRENET PLANES IN MINKOWSKI 3-SPACE

Ucum, Ali,Ilarslan, Kazim,Karakus, Siddika Ozkaldi The Honam Mathematical Society 2014 호남수학학술지 Vol.36 No.3

In this study, we have investigated the possibility of whether any spacelike Frenet plane of a given space curve in Minkowski 3-space $\mathbb{E}_1^3$ also is any spacelike Frenet plane of another space curve in the same space. We have obtained some characterizations of a given space curve by considering nine possible case.

Frailty Status Is a More Robust Predictor Than Age of Spinal Tumor Surgery Outcomes: A NSQIP Analysis of 4,662 Patients

Syed Faraz Kazim,Alis J. Dicpinigaitis,Christian A. Bowers,Smit Shah,William T. Couldwell,Rachel Thommen,Daniel J. Alvarez-Crespo,Matthew Conlon,Omar H. Tarawneh,John Vellek,Kyril L. Cole,Jose F. Domi 대한척추신경외과학회 2022 Neurospine Vol.19 No.1

Objective: The present study aimed to evaluate the effect of baseline frailty status (as measured by modified frailty index-5 [mFI-5]) versus age on postoperative outcomes of patients undergoing surgery for spinal tumors using data from a large national registry. Methods: The National Surgical Quality Improvement Program database was used to collect spinal tumor resection patients’ data from 2015 to 2019 (n = 4,662). Univariate and multivariate analyses for age and mFI-5 were performed for the following outcomes: 30-day mortality, major complications, unplanned reoperation, unplanned readmission, hospital length of stay (LOS), and discharge to a nonhome destination. Receiver operating characteristic (ROC) curve analysis was used to evaluate the discriminative performance of age versus mFI-5. Results: Both univariate and multivariate analyses demonstrated that mFI-5 was a more robust predictor of worse postoperative outcomes as compared to age. Furthermore, based on categorical analysis of frailty tiers, increasing frailty was significantly associated with increased risk of adverse outcomes. ‘Severely frail’ patients were found to have the highest risk, with odds ratio 16.4 (95% confidence interval [CI],11.21–35.44) for 30-day mortality, 3.02 (95% CI, 1.97–4.56) for major complications, and 2.94 (95% CI, 2.32–4.21) for LOS. In ROC curve analysis, mFI-5 score (area under the curve [AUC] = 0.743) achieved superior discrimination compared to age (AUC = 0.594) for mortality. Conclusion: Increasing frailty, as measured by mFI-5, is a more robust predictor as compared to age, for poor postoperative outcomes in spinal tumor surgery patients. The mFI-5 may be clinically used for preoperative risk stratification of spinal tumor patients.