Radar Absorbing Capability and Fatigue Properties of Unidirectional Carbon Fabric-Reinforced Composites

Gulsah Pamuk,Ugur Kemiklioglu 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

Radar absorbing materials can be exposed to very different loading conditions during their use. A fracture that may occur within the composite can affect its electrical behavior as well as its strength. For this reason, they must show mechanical strength besides their radar absorbing capability. In this study, two-layer, four-layer, six-layer and eight-layer composite plates in different stacking sequences were compared in terms of attenuation, fatigue behavior and tensile strength. Free space measurements for radar absorption were conducted in a frequency range of 6–14 GHz. Maximum reflection loss was seen in the eight layered 0°/90° composite with 66.89 dB. Cyclic loading was applied to carbon fiber composites in a sinusoidal waveform at a frequency of 3 Hz and the fatigue limit strength was evaluated as the maximum cyclic stress at 105 cycles. It is found that the maximum fatigue strength occurred in six-layered composites. SEM analysis showed that more fringing in 0°/90° oriented composites.

Determination of an Optimal Frailty Cutoff Score of Tilburg Frailty Indicator and Frailty Associated Factors in Community-Dwelling Turkish Older Adults

Gulsah Ozsoy,Esra Ates Bulut,Baris Gurpinar,Nursen Ilcin,Ahmet Turan Isik 대한노인병학회 2021 Annals of geriatric medicine and research Vol.25 No.4

Background: Frailty is a multidimensional and dynamic state that has adverse physical, psychological, and social outcomes. The Tilburg Frailty Indicator (TFI) has the most robust evidence of reliability and validity for assessing frailty. However, the characteristics of TFI have not been investigated in detail. This study aimed to set a cutoff score for frailty and evaluate frailty-associated factors in community-dwelling older adults. Methods: This cross-sectional study assessed frailty according to both the TFI and Fried criteria. The Geriatric Depression Scale, basic and instrumental activities of daily living, and Hospital Anxiety and Depression Scale-Anxiety subscale were also implemented. Results: This study included 166 older adults. The area under the receiver operating characteristic curve was 0.735 (95% confidence interval, 0.648–0.823). A TFI cutoff point of 8, showed a sensitivity of 60% and specificity of 72.5% for the prediction of frailty (p<0.05). Frailty according to the TFI was more associated with the physical and psychological parameters, while frailty according to the Fried score was more closely related to the physical parameters (p<0.05). Conclusion: The results of this study suggested an optimal TFI cutoff score of 8 as a frailty instrument in community-dwelling older adults. Additionally, the TFI included physical, psychological, and social aspects, thereby providing a multidimensional evaluation of frailty.

Role of Soluble Adiponectin Receptor 2 in Non-Alcoholic Fatty Liver Disease in Children

Gulsah Kaya Aksoy,Reha Artan,Cihat Aksoy,Sebahat Özdem,Atike Atalay,Aygen Yılmaz 대한소아소화기영양학회 2019 Pediatric gastroenterology, hepatology & nutrition Vol.22 No.5

Purpose: The incidence of non-alcoholic fatty liver disease (NAFLD) in children is gradually increasing. The aim of this study was to investigate the use of serum adiponectin and soluble adiponectin receptor 2 (soluble Adipo R2) levels for the diagnosis of fatty liver disease in obese and overweight children. Methods: The study included 51 obese and overweight children between the ages of 6 and 18 years diagnosed with NAFLD using ultrasonography and 20 children without fatty liver disease. Patients whose alanine transaminase level was two times higher than normal (≥80 U/L) were included in the non-alcoholic steatohepatitis (NASH) group. Results: NASH was observed in 11 (21.6%) of the patients with NAFLD. The incidence of obesity was higher in patients with NASH (80% and 45%, p=0.021). While the adiponectin levels were similar in patients with NAFLD and those without, they were below the normal level in the whole study group. Adiponectin and soluble Adipo R2 levels of patients with NASH were lower than those in patients without NASH; however, this difference was not statistically significant (p=0.064 and p=0.463). Soluble Adipo R2 levels in obese patients with NAFLD were higher than those in obese children without NAFLD (p<0.001). Conclusion: Soluble adiponectin receptor 2 level is a noninvasive marker that can be used for the diagnosis of NAFLD in obese children.

Role of Soluble Adiponectin Receptor 2 in Non-Alcoholic Fatty Liver Disease in Children

Aksoy, Gulsah Kaya,Artan, Reha,Aksoy, Cihat,Ozdem, Sebahat,Atalay, Atike,Yilmaz, Aygen The Korean Society of Pediatric Gastroenterology 2019 Pediatric gastroenterology, hepatology & nutrition Vol.22 No.5

Purpose: The incidence of non-alcoholic fatty liver disease (NAFLD) in children is gradually increasing. The aim of this study was to investigate the use of serum adiponectin and soluble adiponectin receptor 2 (soluble Adipo R2) levels for the diagnosis of fatty liver disease in obese and overweight children. Methods: The study included 51 obese and overweight children between the ages of 6 and 18 years diagnosed with NAFLD using ultrasonography and 20 children without fatty liver disease. Patients whose alanine transaminase level was two times higher than normal (${\geq}80U/L$) were included in the non-alcoholic steatohepatitis (NASH) group. Results: NASH was observed in 11 (21.6%) of the patients with NAFLD. The incidence of obesity was higher in patients with NASH (80% and 45%, p=0.021). While the adiponectin levels were similar in patients with NAFLD and those without, they were below the normal level in the whole study group. Adiponectin and soluble Adipo R2 levels of patients with NASH were lower than those in patients without NASH; however, this difference was not statistically significant (p=0.064 and p=0.463). Soluble Adipo R2 levels in obese patients with NAFLD were higher than those in obese children without NAFLD (p<0.001). Conclusion: Soluble adiponectin receptor 2 level is a noninvasive marker that can be used for the diagnosis of NAFLD in obese children.

Effect of glide path preparation with PathFile and ProGlider on the cyclic fatigue resistance of WaveOne nickel-titanium files

Uslu, Gulsah,Inan, Ugur The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.2

Objectives: The aim of this study was to investigate the effect of glide path preparation with PathFile and ProGlider nickel-titanium (NiTi) files on the cyclic fatigue resistance of WaveOne NiTi files. Materials and Methods: Forty-four WaveOne Primary files were used and divided into four groups (n = 11). In the first group (0 WaveOne), the WaveOne Primary files served as a control group and were not used on acrylic blocks. In the 1 WaveOne Group, acrylic blocks were prepared using only WaveOne Primary files, and in the PF+WaveOne group and PG+WaveOne groups, acrylic blocks were first prepared with PathFile or ProGlider NiTi files, respectively, followed by the use of WaveOne Primary files. All the WaveOne Primary files were then subjected to cyclic fatigue testing. The number of cycles to failure was calculated and the data were statistically analyzed using one-way analysis of variance (ANOVA) and the Tukey honest significant difference multiple-comparison test at a 5% significance level. Results: The highest number of cycles to failure was found in the control group, and the lowest numbers were found in the 1 WaveOne group and the PF+WaveOne group. Significant differences were found among the 1 WaveOne, PF+WaveOne, and control groups (p < 0.05). No statistically significant differences were found between the PG+WaveOne group and the other three groups (p > 0.05). Conclusion: Glide path preparation with NiTi rotary files did not affect the cyclic fatigue resistance of WaveOne Primary files used on acrylic blocks.

Which Endometrial Pathologies Need Intraoperative Frozen Sections?

Balik, Gulsah,Kagitci, Mehmet,Ustuner, Isik,Akpinar, Funda,Guven, Emine Seda Guvendag Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: Endometrial cancers are the most common gynecologic cancers. Endometrial sampling is a preferred procedure for diagnosis of the endometrial pathology. It is performed routinely in many clinics prior to surgery in order to exclude an endometrial malignancy. We aimed to investigate the accuracy of endometrial sampling in the diagnosis of endometrial pathologies and which findings need intra-operative frozen sections. Materials and Methods: Three hundred nine women applying to a university hospital and undergoing endometrial sampling and hysterectomy between 2010 and 2012 were included to this retrospective study. Data were retrieved from patient files and pathology archives. Results: There was 17 patients with malignancy but endometrial sampling could detect this in only 10 of them. The endometrial sampling sensitivity and specificity of detecting cancer were 58.8% and 100%, with negative and positive predictive values of 97.6%, and 100%, respectively. In 7 patients, the endometrial sampling failed to detect malignancy; 4 of these patients had a preoperative diagnosis of complex atypical endometrial hyperplasia and 2 patients had a post-menopausal endometrial polyps and 1 with simple endometrial hyperplasia. Conclusions: There is an increased risk of malignancy in post-menopausal women especially with endometrial polyps and complex atypia hyperplasia. Endometrial sampling is a good choice for the diagnosis of endometrial pathologies. However, the diagnosis should be confirmed by frozen section in patients with post-menopausal endometrial polyps and complex atypia hyperplasia.

Circulating miR-195 as a Therapeutic Biomarker in Turkish Breast Cancer Patients

Cecener, Gulsah,Ak, Secil,Eskiler, Gamze Guney,Demirdogen, Elif,Erturk, Elif,Gokgoz, Sehsuvar,Polatkan, Volkan,Egeli, Unal,Tunca, Berrin,Tezcan, Gulcin,Topal, Ugur,Tolunay, Sahsine,Tasdelen, Ismet Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.9

Background: Dysregulation of miRNA expression may be used as a biomarker for specific tumours because it may contribute to development of cancer. Circulating miRNA profiles have been highlighted for their potential as predictive markers in heterogeneous diseases such as breast cancer. In the literature, there is evidence that miR-195 levels are differentially expressed pre- and post-operative periods in breast cancer patients. At the same time, miRNA expression levels may vary because of ethnic origins. This study aimed to determine expression levels and potential roles of miR-195 in Turkish breast cancer patients. Materials and Methods: The expression patterns of miR-195 were initially examined in breast cancer tissues (luminal A and B type) (n=96). Subsequently, blood samples were prospectively collected from preoperative and postoperative Turkish breast cancer patients and disease free controls. Total RNA was isolated, and the expression level of miR-195 was quantified by real-time PCR. Results: We found that miR-195 level was altered in Turkish breast cancer patients, with down-regulation evident in breast cancer tissues compared to normal adjacent specimens. Furthermore, circulating levels of miR-195 was significantly decreased in post-operative blood samples compared with pre-operative levels (p=0.01 and <0.05). However, miR-195 was significantly increased in pre-operative blood samples of the luminal B type (p=0.04 and <0.05). Conclusions: This study represents the first report of a miR-195 expression profile in Turkish breast cancer patients. Our data suggests that miR-195 levels might be a clinically useful biomarker in the earliest stage of Turkish breast cancer patients.

Insertion/Deletion Polymorphism of the Angiotensin ConvertingEnzyme Gene in Coronary Artery Disease in Southern Turkey

Abdi Bozkurt,Gulsah Seydaoglu,Esmeray Acart?k,G?en Attila,Onur Akplnar,Sel?k Matyar 한국생화학분자생물학회 2005 BMB Reports Vol.38 No.4

Evaluation of Genetic Variations in miRNA-Binding Sites of BRCA1 and BRCA2 Genes as Risk Factors for the Development of Early-Onset and/or Familial Breast Cancer

Erturk, Elif,Cecener, Gulsah,Polatkan, Volkan,Gokgoz, Sehsuvar,Egeli, Unal,Tunca, Berrin,Tezcan, Gulcin,Demirdogen, Elif,Ak, Secil,Tasdelen, Ismet Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Although genetic markers identifying women at an increased risk of developing breast cancer exist, the majority of inherited risk factors remain elusive. Mutations in the BRCA1/BRCA2 gene confer a substantial increase in breast cancer risk, yet routine clinical genetic screening is limited to the coding regions and intronexon boundaries, precluding the identification of mutations in noncoding and untranslated regions. Because 3' untranslated region (3'UTR) polymorphisms disrupting microRNA (miRNA) binding can be functional and can act as genetic markers of cancer risk, we aimed to determine genetic variation in the 3'UTR of BRCA1/BRCA2 in familial and early-onset breast cancer patients with and without mutations in the coding regions of BRCA1/BRCA2 and to identify specific 3'UTR variants that may be risk factors for cancer development. The 3'UTRs of the BRCA1 and BRCA2 genes were screened by heteroduplex analysis and DNA sequencing in 100 patients from 46 BRCA1/2 families, 54 non-BRCA1/2 families, and 47 geographically matched controls. Two polymorphisms were identified. SNPs $c.^*1287C$ >T (rs12516) (BRCA1) and $c.^*105A$ >C (rs15869) (BRCA2) were identified in 27% and 24% of patients, respectively. These 2 variants were also identified in controls with no family history of cancer (23.4% and 23.4%, respectively). In comparison to variations in the 3'UTR region of the BRCA1/2 genes and the BRCA1/2 mutational status in patients, there was a statistically significant relationship between the BRCA1 gene polymorphism $c.^*1287C$ >T (rs12516) and BRCA1 mutations (p=0.035) by Fisher's Exact Test. SNP $c.^*1287C$ >T (rs12516) of the BRCA1 gene may have potential use as a genetic marker of an increased risk of developing breast cancer and likely represents a non-coding sequence variation in BRCA1 that impacts BRCA1 function and leads to increased early-onset and/or familial breast cancer risk in the Turkish population.

Molecular Markers for Patients with Thymic Malignancies: not Feasible at Present?

Avci, Nilufer,Cecener, Gulsah,Deligonul, Adem,Erturk, Elif,Tunca, Berrin,Egeli, Unal,Tezcan, Gulcin,Akyildiz, Elif Ulker,Bayram, Ahmet Sami,Gebitekin, Cengiz,Kurt, Ender,Evrensel, Turkkan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Background: Thymomas and thymic carcinomas are rare malignancies and devising clinically effective molecular targeted therapies is a major clinical challenge. The aim of the study was to analyze BLC2 and vascular endothelial growth factor receptor (VEGFR) expression and KRAS and EGFR mutational status and to correlate them with the clinical characteristics of patients with thymomas and thymic carcinomas. Materials and Methods: A total of 62 patients (mean age: $50.4{\pm}13.2$ years) with thymomas and thymic carcinomas were enrolled. The expression of BLC2 and VEGFR in tumor cells and normal tissues was evaluated by RT-PCR. The mutational status of the KRAS and EGFR genes was investigated by PCR with sequence specific primers. Results: The BLC2 and VEGFR expression levels did not differ significantly between tumor and normal tissues. Moreover, there were no clearly pathogenic mutations in KRAS or EGFR genes in any tumor. None of the molecular markers were significantly related to clinical outcomes. Conclusions: Changes in levels of expression of BLC2 and VEGFR do not appear to be involved in thymic tumorigenesis. Moreover, our data suggest that KRAS and EGFR mutations do not play a major role in the pathogenesis of thymomas and thymic carcinomas.