An Efficiency Analysis of Takaful Insurance Industry: A Comparative Study

Ali COSKUN,Houshang HABIBNIYA,Yavuz KECELI 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.7

Takaful, which is an Islamic insurance instrument, manages risks in business, according to Shariah (Islamic law) principles and offers risk protection and savings assets. The study analyzes the comparative efficiency of takaful insurance companies by implementing empirical research. The study also provides a comprehensive literature review on the efficiency analysis of the takaful industry. The empirical part presents a wide range of efficiency comparisons of 41 takaful insurance companies in 16 countries between 2009 and 2014. The data enveloping analysis technique is utilized using the rDEA package in the R environment to compute the efficiency score. In the study, the technical efficiency, overall technical efficiency, and pure technical efficiency are calculated and compared per year and per country. The findings of the study suggest that the overall average efficiency scores of takaful companies are considerably high. The study results also indicate that the excess in the consumption of inputs decreases while the deficit in achieved outputs has been declining in the covered period. The study suggests the managers of the takaful companies can use the target efficiency scores, which are calculated by using the DEA analysis, as an ideal reference benchmark for planning their inputs and outputs.

High hopes: can molecular electronics realise its potential?

Coskun, Ali,Spruell, Jason M.,Barin, Gokhan,Dichtel, William R.,Flood, Amar H.,Botros, Youssry Y.,Stoddart, J. Fraser The Royal Society of Chemistry 2012 Chemical Society reviews Vol.41 No.14

<P>Manipulating and controlling the self-organisation of small collections of molecules, as an alternative to investigating individual molecules, has motivated researchers bent on processing and storing information in molecular electronic devices (MEDs). Although numerous ingenious examples of single-molecule devices have provided fundamental insights into their molecular electronic properties, MEDs incorporating hundreds to thousands of molecules trapped between wires in two-dimensional arrays within crossbar architectures offer a glimmer of hope for molecular memory applications. In this critical review, we focus attention on the collective behaviour of switchable mechanically interlocked molecules (MIMs)—specifically, bistable rotaxanes and catenanes—which exhibit reset lifetimes between their ON and OFF states ranging from seconds in solution to hours in crossbar devices. When these switchable MIMs are introduced into high viscosity polymer matrices, or self-assembled as monolayers onto metal surfaces, both in the form of nanoparticles and flat electrodes, or organised as tightly packed islands of hundreds and thousands of molecules sandwiched between two electrodes, the thermodynamics which characterise their switching remain approximately constant while the kinetics associated with their reset follow an intuitively predictable trend—that is, fast when they are free in solution and sluggish when they are constrained within closely packed monolayers. The importance of seamless interactions and constant feedback between the makers, the measurers and the modellers in establishing the structure-property relationships in these integrated functioning systems cannot be stressed enough as rationalising the many different factors that impact device performance becomes more and more demanding. The choice of electrodes, as well as the self-organised superstructures of the monolayers of switchable MIMs employed in the molecular switch tunnel junctions (MSTJs) associated with the crossbars of these MEDs, have a profound influence on device operation and performance. It is now clear, after much investigation, that a distinction should be drawn between two types of switching that can be elicited from MSTJs. One affords small ON/OFF ratios and is a direct consequence of the switching in bistable MIMs that leads to a relatively small remnant molecular signature—an activated chemical process. The other leads to a very much larger signature and ON/OFF ratios resulting from physical or chemical changes in the electrodes themselves. Control experiments with various compounds, including degenerate catenanes and free dumbbells, which cannot and do not switch, are crucial in establishing the authenticity of the small ON/OFF ratios and remnant molecular signatures produced by bistable MIMs. Moreover, experiments conducted on monolayers in MSTJs of molecules designed to switch and molecules designed not to switch have been probed directly by spectroscopic and other means in support of MEDs that store information through switching collections of bistable MIMs contained in arrays of MSTJs. In the quest for the next generation of MEDs, it is likely that monolayers of bistable MIMs will be replaced by robust crystalline extended structures wherein the switchable components, derived from bistable MIMs, are organised precisely in a periodic manner.</P> <P>Graphic Abstract</P><P>There is a world of difference between a molecular electronic device which switches at high (blue) rather than at low (red) bias. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cs35053j'> </P>

Efficacy and Toxicity of Gemcitabine Plus Docetaxel Combination as a Second Line Therapy for Patients with Advanced Stage Soft Tissue Sarcoma

Ali Osman, Kaya,Suleyman, Buyukberber,Metin, Ozkan,Necati, Alkis,Alper, Sevinc,Nuriye Yildirim, Ozdemir,Suleyman, Alici,Onur, Esbah,Veli, Berk,Celalettin, Camci,Arife, Ulas,Ugur, Coskun,Mustafa, Benek Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Purpose: To assess the safety and efficacy of a gemcitabine plus docetaxel regimen as a second line therapy for patients with advanced soft tissue sarcoma (STS) resistant to doxorubicin and ifosfamide-based therapy. Patients and Methods: Medical records of 64 patients with advanced STS who received gemcitabine plus docetaxel regimen as a second line treatment between May 2006 and June 2011 were examined. All patients had been previously treated with doxorubicin plus ifosfamide-based regimen at first line setting. Patients received gemcitabine 900 $mg/m^2$ on days one and eight intravenously over 90 minutes, followed by docetaxel 75 $mg/m^2$ on day eight intravenously over one hour. Cycles were repeated every 3 weeks. Results: The male-to-female ratio was 37/27 and the median age was 44 years (range; 19-67 years). Objective responses were observed in 13 (20.3 %) patients (2 CR, 11 PR) and stable disease in 21 (32.8 %). Total clinical benefit (CR+PR+SD) was observed in 34 (53.1 %). Median overall survival (OS) was 18 months (95% confidence interval (CI):12.1-23.9) and Median time to progression (TTP) was 4.8 months (95% CI: 3.6-6). A total of 243 cycles of chemotherapy were administered. The median number of cycle was 3 (range;1-11). The most common grade 3-4 hematologic toxicity was neutropenia (35.9 %). The most common nonhematologic toxicities consisted of nausea/vomiting (37.5 %), mucositis (32.8 %), peripheral neuropathy (29.7%), and fatigue (26 %). There was no toxicity-related death. Conclusion: The combination of gemcitabine plus docetaxel is an active and tolerable regimen as a second line therapy for patients with advanced soft tissue sarcoma who have failed doxorubicin and ifosfamide-based therapy.

Gynecomastia: A Rare Adverse Effect of Methylphenidate in an Adolescent Boy

Ali Karayagmurlu,Ayse Tugce Varli,Murat Coskun 대한정신약물학회 2020 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.18 No.2

Gynecomastia is a benign condition developing in association with localized fat deposition and glandular tissue proliferation in the breast in males, and characterized by breast growth. Drug is one of the most important factors in the etiology of gynecomastia. Methylphenidate is a commonly preferred and well-tolerated drug in the treatment of attention deficit hyperactivity disorder in children and adolescents. Gynecomastia is an uncommon side-effect of methylphenidate use. We report a case of bilateral gynecomastia developing in a dose-dependent manner during methylphenidate monotherapy and resolving with discontinuation of medication in a 15-year-old patient with a history of a similar side-effect during previous use of the drug. To the best of our knowledge this is one of the few case reports of gynecomastia developing in association with methylphenidate.

Prognostic factors in adult granulosa cell tumors of the ovary: a retrospective analysis of 80 cases

Ali Ayhan,Mehmet Coskun Salman,Melih Velipasaoglu,Mehmet Sakinci,Kunter Yuce 대한부인종양학회 2009 Journal of Gynecologic Oncology Vol.20 No.3

Objective: Ovarian granulosa cell tumors are rare malignancies with a relatively favorable prognosis. However, patients still suffer from disease-related mortality. Therefore, the prognostic factors should be clarified. The purpose of this study was to investigate the clinical and pathologic characteristics related with disease recurrence and mortality in adult type ovarian granulosa cell tumors. Methods: Eighty surgically staged patients with granulosa cell ovarian tumor treated at the Hacettepe University Hospital between 1982 and 2006 were retrospectively reviewed. Clinical and pathological characteristics were analyzed. Results: Granulosa cell ovarian tumors accounted for 4.3% of malignant ovarian neoplasms. Mean age was 47.6 years. The most common presenting symptom was abnormal uterine bleeding (53.7%). Endometrial pathology was detected in 51.2% of patients preoperatively. Seventy percent of patients were diagnosed at stage I, and 53.8% of patients received adjuvant treatment. Mean follow-up was 67.5 months. Overall 5-year and 10-year survival was 91% and 86%, respectively. Mean survival was 147.1 months. Recurrence rate was 11.2%. In univariate analysis, advanced stage, advanced age, residual disease after surgery, and need for adjuvant treatment were associated with disease-related mortality and advanced stage disease and absence of initial staging surgery were associated with disease recurrence. However, in multivariate analysis, only initial stage was found to be a significant prognostic factor. Conclusion: Initial stage seems to be the single most important prognostic factor in ovarian granulosa cell tumors. Therefore, a comprehensive staging surgery should be attempted to document the real extent of disease and to estimate the oncologic outcome more accurately. Objective: Ovarian granulosa cell tumors are rare malignancies with a relatively favorable prognosis. However, patients still suffer from disease-related mortality. Therefore, the prognostic factors should be clarified. The purpose of this study was to investigate the clinical and pathologic characteristics related with disease recurrence and mortality in adult type ovarian granulosa cell tumors. Methods: Eighty surgically staged patients with granulosa cell ovarian tumor treated at the Hacettepe University Hospital between 1982 and 2006 were retrospectively reviewed. Clinical and pathological characteristics were analyzed. Results: Granulosa cell ovarian tumors accounted for 4.3% of malignant ovarian neoplasms. Mean age was 47.6 years. The most common presenting symptom was abnormal uterine bleeding (53.7%). Endometrial pathology was detected in 51.2% of patients preoperatively. Seventy percent of patients were diagnosed at stage I, and 53.8% of patients received adjuvant treatment. Mean follow-up was 67.5 months. Overall 5-year and 10-year survival was 91% and 86%, respectively. Mean survival was 147.1 months. Recurrence rate was 11.2%. In univariate analysis, advanced stage, advanced age, residual disease after surgery, and need for adjuvant treatment were associated with disease-related mortality and advanced stage disease and absence of initial staging surgery were associated with disease recurrence. However, in multivariate analysis, only initial stage was found to be a significant prognostic factor. Conclusion: Initial stage seems to be the single most important prognostic factor in ovarian granulosa cell tumors. Therefore, a comprehensive staging surgery should be attempted to document the real extent of disease and to estimate the oncologic outcome more accurately.

The Relationship between Daily Fructose Consumption and Oxidized Low-Density Lipoprotein and Low-Density Lipoprotein Particle Size in Children with Obesity

Gungor, Ali,Balamtekin, Necati,Ozkececi, Coskun Firat,Aydin, Halil Ibrahim The Korean Society of Pediatric Gastroenterology 2021 Pediatric gastroenterology, hepatology & nutrition Vol.24 No.5

Purpose: Obesity has become a very significant health problem in childhood. Fructose taken in an uncontrolled manner and consumed in excessive amounts is rapidly metabolized in the body and gets converted into fatty acids. This single center prospective case-control study aims to investigate the relationship between fructose consumption and obesity and the role of fructose consumption in development of atherosclerotic diseases. Methods: A total of 40 obese and 40 healthy children who were of similar ages (between 8 and 18 years) and sexes were included in the study. In the patient and control groups, the urine fructose levels, as well as the levels of oxidized low-density lipoprotein (LDL), small dense LDL, Apolipoprotein A and Apolipoprotein B values, which have been shown to play a role in development of atherosclerotic diseases, were measured. Results: The levels of oxidized LDL and small dense LDL and the ratio of Apolipoprotein A/Apolipoprotein B were found to be significantly higher in the patient group. Conclusion: We found that urinary fructose levels were higher in the obese children than the healthy children. Our results suggest that overconsumption of fructose in children triggers atherogenic diseases by increasing the levels of small dense LDL and oxidized LDL and the ratio of Apolipoprotein B/Apolipoprotein A.

A Comparison of Models for Predicting Discretionary Accruals: A Cross-Country Analysis

ACAR, Goksel,COSKUN, Ali Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.9

In this study, we examined various aspects of discretionary accruals. We compared the power of Jones Model (JM), Modified Jones Model (MJM) and Performance Matched Model (PMM). Furthermore, we tested whether accruals derived from cash flow approach or balance sheet approach provide better results and we investigated the significance of country and industry control variables in models. In order to perform these tests, we constructed thirty equations. The data consists of 319 non-financial companies over five years in the GCC region. We used panel data regression models, and testing suggests us to use random effect model as the most suitable one. The results show that PMM has the highest explanatory power among models and it is followed by JM and MJM, consecutively. Secondly, results reveal that accruals derived from cash flow approach provide more accurate results. Moreover, country dummies are significant in models with cash flow approach and they lose significance in balance sheet approach. We differentiated industries due to two different classifications: the first group with higher number of industries is more precise compared to the second group with a narrower scope and lower number of industries. The model including both industrial and country-wise dummies scores highest in significance.

Gemcitabine Plus Paclitaxel as Second-line Chemotherapy in Patients with Advanced Non-Small Cell Lung Cancer

Baykara, Meltem,Coskun, Ugur,Berk, Veli,Ozkan, Metin,Kaplan, Muhammet Ali,Benekli, Mustafa,Karaca, Halit,Inanc, Mevlude,Isikdogan, Abdurrahman,Sevinc, Alper,Elkiran, Emin Tamer,Demirci, Umut,Buyukberb Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Purpose: The aim of this retrospective study was to determine response rates, progression-free survival (PFS), overall survival (OS) and toxicity of gemcitabine and paclitaxel combinations with advanced or metastatic non-small cell lung cancer patients (NSCLC) who have progressive disease after platinum-based first-line chemotherapy. Methods: We retrospectively evaluated the file records of patients treated with gemcitabine plus paclitaxel in advanced or metastatic NSCLC cases in a second-line setting. The chemotherapy schedule was as follows: gemcitabine $1500mg/m^2$ and paclitaxel 150 mg/m2 administered every two weeks. Results: Forty-eight patients (45 male, 3 female) were evaluated; stage IIIB/IV 6/42; PS0, 8.3%, PS1, 72.9%, PS2, 18.8%; median age, 56 years old (range 38-76). Six (12.5%) patients showed a partial response (PR), 13 (27.1%) stable disease (SD), and 27 (56.3%) progressive disease (PD). The median OS was 6.63 months (95% CI 4.0-9.2); the median PFS was 2.7 months (95% CI 1.8-3.6). Grade 3 and 4 hematologic toxicities, including neutropenia (n=4, 8.4%), and anemia (n=3, 6.3%) were encountered, but no grade 3 or 4 thrombocytopenia. One patient developed febrile neutropenia. There were no interruption for reasons of toxicity and no exitus related to therapy. Conclusion: The combination of two-weekly gemcitabine plus paclitaxel was an effective and well-tolerated second-line chemotherapy regimen for advanced or metastatic NSCLC patients previously treated with platinum-containing chemotherapy. Although the most common and dose limiting toxicities were neutropenia and neuropathy, this regimen was tolerated well by the patients.

Bottom-up Approach for the Synthesis of a Three-Dimensional Nanoporous Graphene Nanoribbon Framework and Its Gas Sorption Properties

Byun, Yearin,Coskun, Ali American Chemical Society 2015 Chemistry of materials Vol.27 No.7

<P>We present a new polymerization strategy, that is catalyst-free Diels–Alder cycloaddition polymerization and subsequent FeCl<SUB>3</SUB>-catalyzed intramolecular cyclodehydrogenation reaction, to introduce graphene nanoribbons up to 2 nm in length and 1.1 nm in width into a graphene nanoribbon framework (GNF). The first graphene nanoribbon framework showed high thermal stability up to 400 °C in air with relatively narrow pore size distribution and exhibited BET surface area of 679 m<SUP>2</SUP> g<SUP>–1</SUP>. GNF possesses high affinity for H<SUB>2</SUB> (<I>Q</I><SUB>st</SUB> 7.7 kJ mol<SUP>–1</SUP>, 1.03 wt % at 77 K, 1 bar), CO<SUB>2</SUB> (<I>Q</I><SUB>st</SUB> = 28.7 kJ mol<SUP>–1</SUP>, 94.6 mg g<SUP>–1</SUP> at 273 K, 1 bar), and CH<SUB>4</SUB> (<I>Q</I><SUB>st</SUB> = 24.1 kJ mol<SUP>–1</SUP>, 11.5 mg g<SUP>–1</SUP> at 273 K, 1 bar). The enhancement in gas affinities was attributed to the unique combination of large π-surface area arising from graphene nanoribbons and small pores (∼5.8 Å) in GNF. The application of GNF can also be extended to natural gas purification process with exceptional CO<SUB>2</SUB>/CH<SUB>4</SUB> (5:95) selectivity of 62.7, which is the highest value reported to date at 298 K. Unlike previous studies that focus mostly on increasing the affinity of CO<SUB>2</SUB> toward the sorbent in order to tune CO<SUB>2</SUB>/CH<SUB>4</SUB> selectivity, our approach takes advantage of the kinetic diameter difference between CO<SUB>2</SUB> (3.30 Å) and CH<SUB>4</SUB> (3.80 Å), thus offering a low-cost efficient alternative for the natural gas purification process.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2015/cmatex.2015.27.issue-7/acs.chemmater.5b00246/production/images/medium/cm-2015-00246x_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm5b00246'>ACS Electronic Supporting Info</A></P>

Prognostic Factors for Overall Survival in Patients With Metastatic Colorectal Carcinoma Treated With Vascular Endothelial Growth Factor-Targeting Agents

Cetin, Bulent,Kaplan, Mehmet Ali,Berk, Veli,Ozturk, Selcuk Cemil,Benekli, Mustafa,Isikdogan, Abdurrahman,Ozkan, Metin,Coskun, Ugur,Buyukberber, Suleyman Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Objective: Angiogenesis represents a key element in the pathogenesis of malignancy. There are no robust data on prognostic factors for overall survival (OS) in patients with metastatic colorectal cancer treated with vascular endothelial growth factor (VEGF)-targeted therapy. The present study was conducted to establish a prognostic model for patients using an oxaliplatin-based or irinotecan-based chemotherapy plus bevacizumab in metastatic colorectal cancer. Methods: Baseline characteristics and outcomes on 170 patients treated with FOLFIRI or XELOX plus anti-VEGF therapy-naive metastatic colorectal cancer were collected from three Turkey cancer centers. Cox proportional hazards regression was used to identify independent prognostic factors for OS. Results: The median OS for the whole cohort was 19 months (95% CI, 14.3 to 23.6 months). Three of the seven adverse prognostic factors according to the Anatolian Society of Medical Oncology (ASMO) were independent predictors of short survival: serum lactate dehydrogenase (LDH) greater than the upper limit of normal (ULN; p<0.001); neutrophils greater than the ULN (p<0.0014); and progression free survival (PFS) less than 6 months (p =0.001). Conclusion: Serum LDH and neutrophil levels were the main prognostic factors in predicting survival, followed by PFS. This model validates incorporation of components of the ASMO model into patient care and clinical trials that use VEGF-targeting agents.