Production and investigation of 3D printer ABS filaments filled with some rare-earth elements for gamma-ray shielding

Gultekin Batuhan,Bulut Fatih,Yildiz Hatice,Us Hakan,Ogul Hasan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.12

Radiation is the main safety issue for almost all nuclear applications, which must be controlled to protect living organisms and the surrounding materials. In this context, radiation shielding materials have been investigated and used in nuclear technologies. The choice of materials depends on the radiation usage area, type, and energy. Polymer materials are preferred in radiation shielding applications due to their superior characteristics such as chemical inertness, resistivity, low weight, flexibility, strength, and low cost. In the presented work, ABS polymer material, which is possibly the most commonly used material in 3D printers, is mixed with Gd2O3 and Er2O3 nanoparticles. ABS filaments containing these rare-earth elements are then produced using a filament extruder. These produced filaments are used in a 3D printer to create shielding samples. Following the production of shielding samples, SEM, EDS, and gamma-ray shielding analyses (including experiments, WinXCOM, GEANT4, and FLUKA) are performed. The results show that 3D printing technology offers significant enhancements in creating homogeneous and well-structured materials that can be effectively used in gamma-ray shielding applications.

Association Between High Platelet Indices and Proteinuria in Patients With Hypertension

Ihsan Ates,Mesudiye Bulut,Nihal Ozkayar,Fatih Dede 대한진단검사의학회 2015 Annals of Laboratory Medicine Vol.35 No.6

Background: We aimed to determine the association between platelet indices including plateletcrit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), and proteinuria associated with hypertension (HT) as well as the relative power of each to predict proteinuria. Methods: The study included 223 patients (68 men and 155 women) with primary HT. PCT, MPV, PDW, and proteinuria levels were measured. The patients were divided into two groups according to proteinuria status based on 24-hr urinary protein excretion: proteinuria (+) group (15 men and 40 women) and proteinuria (-) group (53 men and 115 women). Results: The mean and SD of platelet count, PDW, PCT, and MPV were 278.8±49.6 ×109/L, 13.5±1.8%, 0.31±0.07%, and 11.3±2.6 fL, respectively. The mean platelet count, PCT, MPV, and PDW were significantly higher in the proteinuria (+) group than in the proteinuria (-) group (P<0.05); there were no significant differences in the other blood parameters between the two groups. The platelet count, PCT, MPV, and PDW were independent risk factors predictive of proteinuria according to a stepwise regression analysis of PDW, PCT, and MPV. PCT was the strongest independent predictor of proteinuria. Conclusions: The platelet indices PCT, PDW, and MPV were significantly higher in patients with proteinuria than in those without it. Among these three indices, PCT was the strongest predictor of proteinuria.

A comparative study of 3D printing and sol-gel polymer production techniques: A case study on usage of ABS polymer for radiation shielding

Ogul Hasan,Gultekin Batuhan,Bulut Fatih,Us Hakan 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

This study focuses on the comparative analysis of ABS polymer samples produced using two distinct manufacturing techniques: 3D printing and the sol-gel methods. In the first approach, ABS polymer was augmented with rare earth oxides, Er2O3 and Gd2O3, in nano powder form and fabricated into test specimens using 3D printing technology. In the second approach, identical samples were prepared via the sol-gel technique involving mold-based fabrication. Elemental content analysis revealed no significant differences between the samples produced by the two methods. The study proceeds to evaluate the gamma-ray shielding, neutron shielding, temperature resistance, and SEM/EDS pictures of ABS samples generated through both techniques. 3D printing method exhibited more favorable results in terms of structure morphology and thermal stability while there is no significant difference for radiation shielding. The results provide insights into the performance and suitability of each production method for radiation shielding applications. This research not only contributes to enhancing radiation shielding technology but also informs the selection of the most appropriate fabrication method for specific applications in nuclear technologies and diagnostic energy range in medical purposes.

Decreased Serum Sulphydryl Levels as a Sign of Increased Oxidative Stress in Generalized Anxiety Disorder

Mehmet Cemal Kaya,Yasin Bez,Ibrahim Fatih Karababa,Ali Emhan,Nurten Aksoy,Mahmut Bulut,Mehmet Gunes,Abdullah Atli,Salih Selek 대한신경정신의학회 2013 PSYCHIATRY INVESTIGATION Vol.10 No.3

Objective In recent years, many published studies have focused on the relationship between oxidative stress and psychiatric disorders. However, studies in generalized anxiety disorder (GAD) are few despite relatively high prevalence rates. In an attempt to fill this gap in the literature we aimed to measure serum levels of free sulphydryl, an important member of antioxidant defense mechanisms, of the patients with GAD. Methods A total of 35 (23 female, 12 male) GAD patients without any other co-morbid medical or psychiatric disorder and 35 (23 female, 12 male) healthy controls have been included in the study. Disease severity of the patients were quantified by using the Hamilton Anxiety Rating Scale (HAM-A). Serum free sulphydryl group levels of patients and healthy controls were measured in an appropriate way. Results Mean level of serum sulphydryl groups was significantly lower in the patient group. There was a negative correlation between their level and the disease duration. However, they did not show any significant correlation with the disease severity. Conclusion Decreased serum sulphydryl level observed in pure GAD patients suggests an increased oxidative stress in these patients. Well designed future researches are needed to replicate our findings and to test the implications of the present study.

Investigation of risk factors for community-acquired urinary tract infections caused by extended-spectrum beta-lactamase Escherichia coli and Klebsiella species

Eda Koksal,Necla Tulek,Meliha Cagla Sonmezer,Fatih Temocin,Cemal Bulut,Cigdem Hatipoglu,Fatma Sebnem Erdinc,Gunay Ertem 대한비뇨의학회 2019 Investigative and Clinical Urology Vol.60 No.1

Purpose: The aim of this study was to determine the prevalence and risk factors for community-acquired urinary tract infections (CA-UTIs) caused by extended-spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella species. Materials and Methods: The patients diagnosed with CA-UTIs caused by E. coli or Klebsiella spp. were included in the study. All of the patients were compared to demographic characteristics, underlying diseases, urinary tract pathology, history of hospitalization, use of antibiotics according to ESBL positivity. Results: A total of 322 urine isolates were studied. Sixty-six patients (37.1%) of a total of 178 patients were ESBL positive E. coli and Klebsiella spp. Being over the age of sixty (odds ratio [OR], 1.90; p=0.03), history of renal stone (OR, 3.00; p=0.03), urinary tract anatomical of physiological disorder (OR, 2.17; p=0.01), urologic intervention (OR, 3.43; p<0.001), history of urinary tract surgery (OR, 3.10; p=0.01), history of urinary catheterization (OR, 3.43; p<0.001), and hospitalization for last 1 year (OR, 3.70; p=0.01) and antibiotic usage in the last 3 months (OR, 1.90; p=0.04) were found as significant risk factors for the producing of ESBL. However, gender and underlying disease were not related for ESBL production. Conclusions: In present study, high rate of ESBL positivity was detected in CA-UTIs. The increasing of infections caused by ESBL positive E. coli and Klebsiella spp. are bringing together a lot of the problem, such as antibiotic resistance and reducing treatment options for outpatients. Identification of underlying risk factors would be important for the development of preventive strategies.

Patients with HER2-positive Early Breast Cancer Receiving Adjuvant Trastuzumab: Clinicopathological Features, Efficacy, and Factors Affecting Survival

Ulas, Arife,Kos, Tugba,Avci, Nilufer,Cubukcu, Erdem,Olmez, Omer Fatih,Bulut, Nilufer,Degirmenci, Mustafa Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4

Background: The aim of the present study was to evaluate clinicopathological characteristics of our early stage breast cancer patients who are epidermal growth factor receptor 2 (HER2) overexpressed/amplified (HER2+), the efficacy of trastuzumab treatment and survival results. Materials and Methods: Patients with HER2-positive early stage breast cancer receiving adjuvant trastuzumab were investigated retrospectively. Clinicopathological features of 210 patients and treatment outcome were analysed. To evaluate survival rates, the Kaplan-Meier method was used. Univariate and multivariate analyses were conducted with the Cox regression model. Results: Mean age of the patients was 51.8, 71.9% being postmenopausal. Some 37.6% of patients were node negative, and 31% had T1 tumor size and 52.4% were positive for estrogen receptor. Of 210 patients, 89.5% completed planned 52 weeks adjuvant trastuzumab treatment. The median follow up was 27.5 months (6.0-86.0). Relapse free survival (RFS) was 68.0 months (95% CI: 62.1-74.0) and overall survival (OS) was 74.8 months (95% CI: 69.5-80.1). The 3 year OS for all patients was 92.0% and RFS was 79.6%. During follow up, relapse was detected at the rate of 14.3%. Trastuzumab associated cardiotoxicity was found at the rate of 3.3%. In univariate analyses, larger tumor size and grade III were significantly associated (p<0.05) with RFS. Multivariate analyses of covariates displaying p<0.05 identified grade III as an independent prognostic factor. Conclusions: In the present study, it was established that trastuzumab had a satisfactory safety profile and treatment efficacy as in other clinical studies and that among clinicopathological factors evaluated, only being grade 3 had a significant effect on RFS. The occurrence of relapse with adjuvant trastuzumab makes it necessary to identify molecular predictors, which will define this group better and help explain resistance to anti HER2 based therapies.