Browsing by Author "Yildirim, S"

Now showing 1 - 13 of 13
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    Are Hormonal Agents Better Than Chemo in Metastatic Castration-resistant Prostate Cancer?
    Yildirim, S; Erdogan, AP
    OBJECTIVE In this study, we aim to determine which treatment is more appropriate in castration-resistant chemotherapy-naive patients. Therefore, docetaxel and agents active in the androgen pathway (abiraterone and enzalutamide) were compared retrospectively in patients progressing on androgen deprivation therapy. METHODS The study was designed as a retrospective and multicenter study. Patients from five centers in Turkey were included in the study. The primary endpoint of the study was overall survival (OS) and the secondary endpoint was progression-free survival. RESULTS Median OS of the docetaxel group was 18.66 months, it was 16.26 months in the hormonal treatment group. There was no statistically significant difference between the groups (p=0.311). Median progression free survival of the chemotherapy group was 5.6 months, while it was 9 months in the hormonal therapy group. There was statistically significant difference between the groups (p=0.024). CONCLUSION There was statistical difference in progression-free survival in favor of hormonal therapies in our study. The difference did not reflect on OS and there was no difference between hormonal therapies and docetaxel. Heterogeneity in the selection of patients is considered to lead to this result; however, larger randomized controlled studies are needed to determine the most appropriate treatment in these patients.
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    Dielectrical, optical, and structural characterization of TiO2/PVA nanocomposite films for dielectric applications
    Gultekin, S; Yildirim, S; Celik, E; Alicikus, LZA
    In this study, titanium dioxide/poly(vinyl) alcohol (TiO2/PVA) nanocomposite thin films were prepared by a simple spin-coating method for dielectric applications. Structural, morphological, optical, and dielectric properties of samples were analyzed by XRD, SEM, AFM, UV-VIS, and dielectric measurements. The effect of TiO2 nanoparticles on these properties was investigated. It was found that TiO2 nanoparticles lead to increase the crystallinity of nanocomposites. As TiO2 content in the composite structure increases, while average transmittance values decrease, reflectance values increase. The dielectric parameters such as real and imaginary part of complex permittivity which are related to the stored energy and the dissipation (or loss) of energy were significantly affected by the presence of TiO2 nanoparticles. In addition, alternating current (A.C.) conductivity increased with increasing applied frequency. The A.C. conductivity also confirmed that all the samples exhibited the insulator behavior and obeyed the universal power law.
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    Palliative Biliary Drainage Has No Effect on Survival in Pancreatic Cancer: Medical Oncology Perspective
    Erdogan, AP; Ekinci, F; Yildirim, S; Özveren, A; Göksel, G
    Purpose Removal of obstructive jaundice in metastatic pancreatic cancer is an important part of palliative therapy. However, it is not known whether invasive procedures reduce cancer-related mortality. In this study, the effect of palliative biliary drainage on survival outcomes in pancreatic cancer patients was evaluated. Methods Patients diagnosed with pancreatic cancer and undergoing biliary drainage in two different centers between 2010 and 2019 were evaluated retrospectively. Results Biliary drainage was applied to 73 patients, constituting 20.6% of 355 patients included in the study. The median progression-free survival (PFS) of patients with biliary stent was 5 months, while the median PFS of patients without stenting was 5.5 months and the median overall survival (OS) was 11.1 and 11.5 months, respectively (p: 0.424, p: 0.802). Conclusions A positive effect of palliative biliary drainage on median PFS and OS could not be demonstrated in our study group. In pancreatic cancer, predictive markers are needed to select patients who can derive a survival benefit from biliary drainage.
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    Structural and optical properties of SrAl2O4: Eu2+/Dy3+ phosphors synthesized by flame spray pyrolysis technique
    Gültekin, S; Yildirim, S; Yilmaz, O; Keskin, IÇ; Kati, MI; Çelik, E
    In this study Sr0.985Al2O4:0.005Eu(2+)/0.01Dy(3+) luminescent materials with long afterglow and high intensity were synthesized by flame spray pyrolysis (FSP) method for the first time. Precursor solution was divided into two separate part. One of the parts was used FSP process, the other one was dried to simulate sol- gel process. Thermal properties and organic content of FSP derived particles and dried gel were compared using DTA-TG and FTIR devices. FSP derived particles were sintered in argon medium at 1200 degrees C. Phase and elemental analysis of the final phosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photo electron Spectroscopy (XPS) measurements. Scanning electron microscopy (SEM) images were obtained to observe particle morphology. Optical properties of phosphor were determined by Photoluminescence (PL), thermoluminescence (TL) and radioluminescence (RL) measurements. The emission spectra of Sr0.985Al2O4: 0.005Eu(2+)/0.01Dy(3+) were composed by a green band at 525 nm at room temperature when it was excited by 350 nm light, assigned to anomalous luminescence originated by Eu2+ and Dy3+ in the host lattice. There were estimated peaks at around 90, 130, 170 and 200 degrees C under the main glow curve in the sample irradiated by X- ray and He- Ne laser (lambda(exc) = 632 nm). RL spectrum of Sr0.985Al2O4 : 0.005Eu(2+)/0.01Dy(3+) powders have four distinct emission peaks at around 527 nm, 576 nm, 667 nm, 753; nm and a comparatively weak emission band at about 846 nm.
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    Fabrication and characterization of nanostructured anatase TiO2 films prepared by electrochemical anodization and their photocatalytic properties
    Yurddaskal, M; Dikici, T; Yildirim, S; Yurddaskal, M; Toparli, M; Celik, E
    In this study, nanostructured anatase titanium dioxide (TiO2) films were fabricated by electrochemical anodization of titanium first, and then annealed at 500 degrees C for 2 h. Effect of electrolyte concentration, anodization time and electrolyte temperature on the surface morphology of the resulting TiO2 thin films were investigated. The phase structures, surface morphology and chemical composition were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity tests of the samples were evaluated by the degradation of aqueous methylene blue (MB) solutions under UV light illumination for different periods of time. The results showed that the structure of nanostructured TiO2 films depended strongly on the anodization parameters. It was found that there were micro-scale pores (<10 mu m) and nano-scale pores (diameter in the range from 40 to 70 nm) on the anodized titanium surfaces. This study indicated that structures, surface morphology, and surface area of the nanostructured anatase TiO2 films played an important role on their photocatalytic performance. The results clearly proved that nanostructured anatase TiO2 film prepared with optimum process parameters resulted in enhancement of the photocatalytic activity. (C) 2015 Elsevier B.V. All rights reserved.
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    Luminescent properties of scintillator nanophosphors produced by flame spray pyrolysis
    Yildirim, S; Asal, ECK; Ertekin, K; Celik, E
    In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosphors; M'-YTaO4 and M'-Y(Ta0.85Nb0.15)O-4 have been studied for the first time. Phase and elemental analysis of the produced nanophosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) measurements, respectively. The surface morphology and particle size of the nano phosphors were identified using scanning electron microscopy (SEM). The XRD results reveal that the nanophosphors have monoclinic M'-YTaO4 and M'-Y(Ta0.85Nb0.15)O-4 phases belonging to the presence of M'-form of fergusonite structure. The particle sizes of the nanophosphors were found to be in the range of 50-100 nm. The spectroscopic characterization was performed by both radioluminescence (RL) and thermally stimulated luminescence (TSL) measurements after exposure to X-ray irradiation. Also, photoluminescence and decay times were investigated under UV excitation. The nanophosphors can be concluded as appropriate emissive materials for imaging, display and scintillator applications due to the efficient photoluminescence, moderate radioluminescence (RL) and thermally stimulated luminescence characteristics. (C) 2017 Elsevier B.V. All rights reserved.
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    The effect of group work on depression level and family functions of family members caring for stroke patients
    Er, F; Yildirim, S
    Family members are often the caregivers of stroke patients and have an important role in their care and treatment. In this study, it was aimed to support family functionality and reduce depressive symptoms of family members caring for stroke patients with group work method. Family members who care for 14 stroke patients participated in the study and the meetings, the main themes of which were predetermined, lasted for five weeks. The participants were administered the Family Assessment Device'' and Beck Depression Scale'' as pretest and posttest. It was understood that the online group work was effective in the regression of depression symptom level in the participants. Workshops and group workshops should be organized by social workers to reduce the difficulties of family members caring for stroke patients.
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    Acute generalized exanthematous pustulosis due to amoxicilline-clavulanatet
    Sögüt, A; Yilmaz, Ö; Yildirim, S; Özen, S; Temiz, P; Yüksel, H
    Acute generalized exanthematous pustulosis is an uncommon clinical condition characterized by an acute onset of pustular eruptions. A case of acute generalized exanthematous pustulosis after the use of amoxicilline-clavulanate is presented. The patient presented with pustular and pruritic eruptions after use of drug. The diagnosis was confirmed with pathological data. This condition leading to various clinical manifestations should be thought in the differential diagnosis of pustular dermatosis. (Turk Arch Ped 2010; 45: 150-2)
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    Inflammatory Prognostic Index in Metastatic Renal Carcinoma Treated with Nivolumab
    Ekinci, F; Erdogan, AP; Yildirim, S; Bulut, G; Yilmaz, C; Barutca, S
    Objective: To evaluate the utility of inflammatory prognostic index (IPI), albumin, c-reactive protein (CRP), and lactate dehydrogenase (LDH) as predictive biomarkers of oncologic outcome in metastatic renal cell cancer (mRCC) patients treated with nivolumab. Methodology: Seventy-five mRCC patients treated with nivolumab between January 2017 and June 2020 were enrolled. Several factors were retrospectively investigated, including IPI, CRP, LDH, and albumin level, for their association with progression-free survival (PFS) and overall survival (OS). The IPI was calculated as CRP x NLR/albumin. Univariate and multivariate analyses were performed to assess the prognostic value of relevant factors.Results: When analysed according to the calculated IPI score, it is seen that the group with <2.153 has an OS duration of 96.3 months, while the group with >= 2.153 has a shorter time of 42.9 months (p=0.02). In the analysis performed according to albumin level, it was reported that those with low levels (22.8 months) had worse median OS than those with high levels (92.8 months) (p=0.004). According to the cox regression analysis results, it was determined that those with a high IPI score significantly increased the risk of death compared to those with a low score (HR:2.4, p=0.023). However, this significance could not be confirmed in the multivariate analysis. It was analysed that those with low albumin levels significantly increased the risk of death compared to both Conclusion: Those with high IPI scores and low albumin levels were associated with worse median OS. However, only the multivariate analysis analysed albumin level as an independent prognostic variable. Prospective and more extensive research is needed to consolidate the potential prognostic power of these markers.
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    Metastatic Pancreatic Cancer Second-Line Treatment Options: Is the Difference Only in Cost?
    Yildirim, S; Erdogan, AP; Karateke, M; Yilmaz, C; Özveren, A; Bulut, G; Ekinci, F; Almuradova, E
    Introduction Although pancreatic cancer ranks seventh in cancer-related deaths, it is an extremely fatal disease, and more than 330,000 people die from this disease worldwide. Although there are many first-line treatment studies in the literature, there are almost no prospective studies regarding second-line therapy. Therefore, there is no standard approach in the second-line treatment of pancreatic cancer. We decided to conduct this study to investigate second-line treatments with problems such as cost, treatment efficacy, and toxicity. Methods Patients older than 18 years old who applied to Ege University Hospital medical oncology department with a diagnosis of metastatic pancreatic cancer, who received first-line chemotherapy due to their illness, and who had progressed afterwards were included in the study. The files of the patients who applied between 2013 and 2017 were examined. Results Our study's primary endpoint was progression-free survival, and it was found that the median progression-free survival was 3.2 months in the Xelox patients, 3.7 months in the gemcitabine-nab paclitaxel patients, and 3.5 months in the other regimens. When the secondary endpoint was evaluated, overall survival, the median overall survival was 5.9 months in the Xelox patients, 5.3 months in the gemcitabine-nab paclitaxel patients, and 4.8 months in the other regimens. Conclusion As a result, second-line treatments were compared, and no statistically significant difference was found between them. For this reason, the side effects of previously used drugs and the side effects of new drugs to be used, as well as their costs, should be evaluated when choosing a treatment.
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    The correlation of communication skills and emotional expressions among nursing students in Turkey: A public university sample
    Yildirim, S; Durgu, N; Özdes, AB; Özdemir, N
    Background & Aim: Expressing emotions is very important both in interpersonal relationships and in the protection and maintenance of the individual's mental health. However, the individual must have certain skills to express his feelings healthily. The most important of these is communication skills. This research aimed to examine the correlation between communication skills and emotional expressions of nursing students. Methods & Materials: This correlational study was conducted among nursing students at a public university faculty of nursing in Turkey between 2016 and 2017. Of the total of 1423 students, 632 nursing students were selected using the convenience sampling method. The Introductory Information Form, the Berkeley Expressivity Questionnaire and the Communication Skills Scale were used to collect data. The Mann-Whitney U, Kruskal-Wallis H, and Pearson correlation tests were used for the analysis of the data. Results: The mean total Berkeley Expressivity Questionnaire score of the students was found to be 79.45 +/- 10.11, and the mean total score of the Communication Skills Scale was 97.67 +/- 11.20. Emotional expressions are affected by gender, marital status, class, income level, family structure, the residence where they have lived the longest, place of residence and working status (p <= 0.05, p<0.01). It was found that there was a positive-directed correlation between students' emotional expressions and communication skills (p<0.01). Conclusion: It was concluded that communication skills and some sociodemographic characteristics of nursing students are correlated with their emotional expressions.
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    A multicenter survey of childhood asthma in Turkey - II: Utilization of asthma drugs, control levels and their determinants
    Soyer, OU; Beyhun, NE; Demir, E; Yildirim, S; Boz, AB; Altinel, N; Cevit, O; Karakas, T; Anlar, Y; Sögüt, A; Altintas, D; Canitez, Y; Büyükdereli, Z; Sekerel, BE
    Many surveys worldwide have consistently demonstrated a low level of asthma control and under-utilization of preventive asthma drugs. However, these studies have been frequently criticized for using population-based samples, which include many patients with no or irregular follow-ups. Our aim, in this study, was to define the extent of asthma drug utilization, control levels, and their determinants among children with asthma attending to pediatric asthma centers in Turkey. Asthmatic children (age range: 6-18 yr) with at least 1-yr follow-up seen at 12 asthma outpatient clinics during a 1-month period with scheduled or unscheduled visits were included and were surveyed with a questionnaire-guided interview. Files from the previous year were evaluated retrospectively to document control levels and their determinants. From 618 children allocated, most were mild asthmatics (85.6%). Almost 30% and 15% of children reported current use of emergency service and hospitalization, respectively; and 51.4% and 53.1% of children with persistent and intermittent disease, respectively, were on daily preventive therapy, including inhaled corticosteroids. Disease severity [odds ratio: 12.6 (95% confidence intervals: 5.3-29.8)], hospitalization within the last year [3.4 (1.4-8.2)], no use of inhaled steroids [2.9 (1.1- 7.3)], and female gender [2.3 (1.1-5.4)] were major predictors of poor asthma control as defined by their physicians. In this national pediatric asthma study, we found a low level of disease control and discrepancies between preventive drug usage and disease severity, which shows that the expectations of guidelines have not been met even in facilitated centers, thus indicating the need to revise the severity-based approach of asthma guidelines. Efforts to implement the control-based approach of new guidelines (Global Initiative for Asthma 2006) would be worthwhile.
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    Use of electrochemical techniques for determining the effect of brewing techniques (espresso, Turkish and filter coffee) and roasting levels on total antioxidant capacity of coffee beverage
    Yildirim, S; Gok, I; Demir, E; Tokusoglu, O
    In this study, we determined how roasting levels (light, medium, and dark) of Arabica coffee seed and three brewing techniques-decoction methods (Turkish coffee), infusion method (filter coffee), and pressure methods (Espresso)-affect the total antioxidant capacity in a cup of coffee beverage by electrochemical methods such as square wave stripping voltammetry (SWSV), differential pulse stripping voltammetry (DPSV), and cyclic voltammetry (CV). The highest antioxidant capacity was found in espresso coffee prepared with light roasted coffee seeds, as equivalent of rutin and caffeic acid at 9.4 +/- 0.2 g/L and 19.7 +/- 0.7 g/L, respectively with SWSV on a carbon paste electrode (CPE). The antioxidant capacity of coffee beverages was influenced by the roasting degree, extraction time, and brewing methods, significantly. SWSV, DPSV, and CV voltammetric methods, fast, reliable, fully validated and without any pretreatment, are alternatives to conventional analytical methods for evaluation of antioxidant values in coffee brews. Practical applications This research will contribute to the literature considerably since we have established that the antioxidant capacity can be measured by electrochemical methods rapidly with high reliable results. According to the study, the brewing method and roasting temperature significantly affected the antioxidant capacity, and thus, it is important to know how brewing methods, roasting temperatures, and other conditions changes the coffee quality. The results can be used to prepare healthy coffee beverages.