Poly(amidoamine) Functionalized Graphene Oxide Incorporated Carbon/Epoxy Prepreg Composites for Enhanced Electrical and Thermal Properties

Nuri Karakurt,Seckin Erden 한국섬유공학회 2022 Fibers and polymers Vol.23 No.12

Carbon fiber (CF) reinforced epoxy matrix composites were incorporated with 0.5, 1, 2, 4, 7, 10, and 15 wt%poly(amidoamine) (PAMAM) functionalized graphene oxide (GO) via matrix modification. GO was synthesized by chemicaloxidation and PAMAM dendrimer of generation 0.5 (G0.5) was used within the study. Surface chemistry of graphene wasanalyzed by X-ray photoelectron spectroscopy (XPS), which confirmed the oxidation and PAMAM functionalization(PAMAM-GO). After prepregging, laminated composites were manufactured by hot pressing. So produced CF/epoxy-PAMAM-GO composites were thermally analyzed by thermogravimetric analyses (TGA-DTG). The electrical conductivityof the composites was measured in three directions (fiber, transverse, and through-thickness). Mechanical properties wereexamined in means of interlaminar shear strength (ILSS) determined by short beam shear (SBS) tests. The neat graphene,GO, PAMAM-GO, and the fractured composite surfaces were imaged using scanning electron microscopy (SEM). As aresult, PAMAM-GO incorporation significantly enhanced the electrical properties of CF/epoxy composites. Thermal stabilityincreased while the ILSS values decreased.

The Neutrophil to Lymphocyte Ratio has a High Negative Predictive Value for Pathologic Complete Response in Locally Advanced Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

Eryilmaz, Melek Karakurt,Mutlu, Hasan,Salim, Derya Kivrak,Musri, Fatma Yalcin,Tural, Deniz,Coskun, Hasan Senol Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Background: The neutrophil-to-lymphocyte ratio (NLR) is a strong predictor of mortality in patients with pancreatic, colorectal, lung, gastric cancer and renal cell carcinoma. The aim of this study was to determine the relationship between pathological complete response (pCR) and pretreatment NLR values in locally advanced breast cancer (BC) patients receiving neoadjuvant chemotherapy (NACT). Materials and Methods: Datawere collected retrospectively from the Akdeniz University School of Medicine Database for locally advanced BC patients treated with NACT between January 2000-December 2013. Results: A total of 78 patients were analyzed. Sixteen (20%) patients achieved pCR. Estrogen receptor (ER) positivity was lower in pCR+ than pCR-cases (p=0.011). The median NLR values were similar in both arms. The optimum NLR cut-off point for BC patients with PCR+ was 2.33 (AUC:0.544, 95%CI [0.401-0.688], p=0.586) with sensitivity, specificity, positive predictive value and negative predictive value (NPV) of 50%, 51,6%, 21,1%, and 80%, respectively. Conclusions: This study showed no relationship between the pCR and pretreatment NLR values. Because of a considerable high NPV, in the patients with higher NLR who had luminal type BC in which pCR is lower after NACT, such treatment may not be recommended.

Mean Platelet Volume as an Independent Predictive Marker for Pathologic Complete Response after Neoadjuvant Chemotherapy in Patients with Locally Advanced Breast Cancer

Mutlu, Hasan,Eryilmaz, Melek Karakurt,Musri, Fatma Yalccn,Gunduz, Seyda,Salim, Derya Kivrak,Coskun, Hasan Senol Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Background: The impact of mean platelet volume (MPV) on prognosis, diagnosis and response to therapy in cancer patients has been widely investigated. In the present study, we evaluated whether MPV at diagnosis has predictive value for pathologic complete response (pCR) after neoadjuvant chemotherapy in patients with locally advanced breast cancer (LABC). Materials and Methods: A total of 109 patients with LABC from Akdeniz University and Antalya Research and Training Hospital were evaluated retrospectively. Results: ROC curve analysis suggested that the optimum MPV cut-off point for LABC patients with pCR (+) was 8.15 (AUC:0.378, 95%CI [0.256-0.499], p=0.077). The patients with MPV <8.15 had higher pCR rates (29.2% vs. 13.1%, p=0.038). After binary logistic regression analysis, MPV and estrogen receptor absence were independent predictors for pCR. Conclusions: MPV has an independent predictive value for pCR after neoadjuvant chemotherapy in patients with LABC.

A comparative assessment of bagging ensemble models for modeling concrete slump flow

Hacer Yumurtacı Aydogmus,Halil Ibrahim Erdal,Onur Karakurt,Yusuf S. Turkan,Hamit Erdal 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.16 No.5

In the last decade, several modeling approaches have been proposed and applied to estimate the high-performance concrete (HPC) slump flow. While HPC is a highly complex material, modeling its behavior is a very difficult issue. Thus, the selection and application of proper modeling methods remain therefore a crucial task. Like many other applications, HPC slump flow prediction suffers from noise which negatively affects the prediction accuracy and increases the variance. In the recent years, ensemble learning methods have introduced to optimize the prediction accuracy and reduce the prediction error. This study investigates the potential usage of bagging (Bag), which is among the most popular ensemble learning methods, in building ensemble models. Four well-known artificial intelligence models (i.e., classification and regression trees CART, support vector machines SVM, multilayer perceptron MLP and radial basis function neural networks RBF) are deployed as base learner. As a result of this study, bagging ensemble models (i.e., Bag-SVM, Bag-RT, Bag-MLP and Bag-RBF) are found superior to their base learners (i.e., SVM, CART, MLP and RBF) and bagging could noticeable optimize prediction accuracy and reduce the prediction error of proposed predictive models.

Molecular Types and Neoadjuvant Chemotherapy in Patients with Breast Cancer- While Molecular Shifting is More Common in Luminal a Tumors, The Pathologic Complete Response is Most Frequently Observed in Her-2 Like Tumors

Salim, Derya Kivrak,Mutlu, Hasan,Eryilmaz, Melek Karakurt,Musri, Fatma Yalcin,Tural, Deniz,Gunduz, Seyda,Coskun, Hasan Senol Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

Background: Pathologic complete response (pCR) is one of the most important target end-points of neoadjuvant chemotherapy (NACT) in patients with breast cancer (BC). In present study, we aimed to investigate the relationship between molecular subtypes and NACT in patients with BC. Materials and Methods: Using the Akdeniz University database, 106 patients who received NACT for operable breast cancer were retrospectively identified. Prognostic factors before and after NACT were assessed. According to the molecular subtypes, molecular shifting after NACT and tumoral and nodal response to NACT were analyzed. Results: The distribution of subtypes was: Luminal A, 28.3% (n=30); Luminal B, 31.1% (n=33); HER2-like, 24.5% (n=26); and basal like/triple negative (BL/TN), 16.0% (n=17). According to molecular subtypes, pCR rates in both breast and axillary were 0%, 21.4%, 36.4% and 27.3% for luminal A, luminal B, HER2-like and BL/TN, respectively (p=0.018). Molecular subtype shifting was mostly seen in luminal A type (28.6%) after the NACT. The pCR rate in breast and axillary was significantly higher in patients with HER2-like type BC. Conclusions: In patients with HER-2 like type BC, NACT may be offered in early stages. Additionally, due to molecular shifting, adjuvant treatment schedule should be reviewed again, especially in the luminal A group.

The Neutrophil to Lymphocyte Ratio is an Independent Prognostic Factor in Patients with Metastatic Gastric Cancer

Musri, Fatma Yalcin,Mutlu, Hasan,Eryilmaz, Melek Karakurt,Salim, Derya Kivrak,Gunduz, Seyda,Coskun, Hasan Senol Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.3

Inflammation can play an important role in cancer progression and the prognostic importance of neutrophil to lymphocyte ratio (NLR), a marker of inflammation, in cancer is a current investigation topic. In the present study, we aimed to determine whether there is a prognostic link between NLR and metastatic gastric cancer (mGC). A total of 143 patients from the Akdeniz University and Antalya Training and Research Hospital database were retrospectively analyzed. The median NLR value was 3.34. The median overall survival (OS) and median progression-free survival (PFS) were 11.6 and 7.9 months, respectively, in patients with NLR<3.34 while these values were 8.3 and 6.2 months respectively in patients with NLR>3.34 (p<0.001 and p=0.011, respectively). Our study showed that increased NLR is an independent prognostic factor associated with short survival in patients with mGC.

Primary Tumor Resection and Survival in Patients with Stage IV Gastric Cancer

Fatma Yalcin Musri,Hasan Mutlu,Mustafa Karaagac,Melek Karakurt Eryilmaz,Seyda Gunduz,Mehmet Artac 대한위암학회 2016 Journal of gastric cancer Vol.16 No.2

Purpose: The aim of this study was to determine whether surgical resection of the primary tumor contributes to survival in patients with metastatic gastric cancer. Materials and Methods: A total of 288 patients with metastatic gastric cancer from the Akdeniz University, Antalya Training and Research Hospital, and the Meram University of Konya database were retrospectively analyzed. The effect of primary tumor resection on survival of patients with metastatic gastric cancer was investigated using the log-rank test. Kaplan-Meier survival estimates were calculated. Multivariate analysis was performed using Cox proportional hazards regression modeling. Results: The median overall survival was 12.0 months (95% confidence intewrval [CI], 10.4~13.6 months) and 7.8 months (95% CI, 5.5~10.0 months) for patients with and without primary tumor resection, respectively (P<0.001). The median progression-free survival was 8.3 months (95% CI, 7.1~9.5 months) and 6.2 months (95% CI, 5.8~6.7 months) for patients with and without primary tumor resection, respectively (P=0.002). Conclusions: Non-curative gastrectomy in patients with metastatic gastric cancer might increase their survival rate regardless of the occurrence of life-threatening tumor-related complications.

Primary Tumor Resection and Survival in Patients with Stage IV Gastric Cancer

Musri, Fatma Yalcin,Mutlu, Hasan,Karaagac, Mustafa,Eryilmaz, Melek Karakurt,Gunduz, Seyda,Artac, Mehmet The Korean Gastric Cancer Association 2016 Journal of gastric cancer Vol.16 No.2

Purpose: The aim of this study was to determine whether surgical resection of the primary tumor contributes to survival in patients with metastatic gastric cancer. Materials and Methods: A total of 288 patients with metastatic gastric cancer from the Akdeniz University, Antalya Training and Research Hospital, and the Meram University of Konya database were retrospectively analyzed. The effect of primary tumor resection on survival of patients with metastatic gastric cancer was investigated using the log-rank test. Kaplan-Meier survival estimates were calculated. Multivariate analysis was performed using Cox proportional hazards regression modeling. Results: The median overall survival was 12.0 months (95% confidence intewrval [CI], 10.4~13.6 months) and 7.8 months (95% CI, 5.5~10.0 months) for patients with and without primary tumor resection, respectively (P<0.001). The median progression-free survival was 8.3 months (95% CI, 7.1~9.5 months) and 6.2 months (95% CI, 5.8~6.7 months) for patients with and without primary tumor resection, respectively (P=0.002). Conclusions: Non-curative gastrectomy in patients with metastatic gastric cancer might increase their survival rate regardless of the occurrence of life-threatening tumor-related complications.

Is Obesity a Potential Risk factor for Poor Prognosis of COVID-19?

Meltem Agca,Eylem Tuncay,Elif Yıldırım,Reyhan Yıldız,Tülin Sevim,Dilek Ernam,Nermin Ozer Yılmaz,Nazlı Huma Teke,Simge Yavuz,Zuhal Karakurt,COVID-19 Team,Ipek Ozmen 대한감염학회 2021 Infection and Chemotherapy Vol.53 No.2

Background: Coronavirus disease 2019 (COVID-19) continues to cause major mortality and morbidity worldwide even after a year of its emergence. In its early days, hypertension, diabetes, and cardiovascular diseases were noted as poor prognostic factors, while obesity gained attention at a later stage. In the present study, unfavorable clinical outcomes (transfer to the intensive care unit, invasive mechanical ventilation, and mortality) were investigated in obese patients with COVID-19. Materials and Methods: In this retrospective study we analyzed patients with positive polymerase chain reaction test in tertiary care hospital between March-May 2020. They were divided into 3 groups according to body mass index (BMI) as normal, overweight, and obese (BMI: 18.5 - 24.99 kg/m2 , 25 - 29.99 kg/m2 , and ≥ 30 kg/m2 , respectively). We compared clinical features and laboratory findings of these groups and recorded adverse clinical outcomes. Multivariate logistic analysis was performed for unfavorable outcomes. Results: There were 99 patients (35%), 116 (41%), and 69 patients (24%) in the normal-weight, overweight, and obese group, respectively. Among all patients, 52 (18%) patients were transferred to the intensive care unit (ICU), 30 (11%) patients received invasive mechanical ventilation (IMV), and 22 patients (8%) died. Obese patients had minimum 1 more comorbidity than normal BMI patients (73% vs. 50%, P = 0.002), and a longer median (interquartile range [IQR]) duration of hospitalization (8 [5 - 12] vs. 6 [5 - 9]) days, P = 0.006). Obese participants had higher concentrations of serum C-reactive protein, procalcitonin, ferritin than nonobese patients (P <0.05 in all). In a multivariate analysis, obesity was associated with ICU admission (adjusted odds ratio [aOR]: 2.99, 95% confidence interval [CI]: 1.26 - 7.04, P = 0.012). Moreover, IMV requirement was associated with obesity (aOR: 8.73, 95% CI: 2.44 - 31.20, P = 0.001). Mortality occurred in 16%, 9%, and 1% of the obese group, overweight group, and normal-weight group, respectively (Chi-square trend analysis, P = 0.002). Conclusion: Obesity is a risk factor for adverse outcomes and caused increased mortality, hence requiring close follow-up.