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Koleksiyondaki öğeler
- BildiriAçık Erişim2015Seismic Motion Control of a Column Using a Gyroscope
Ünker, F.; Çuvalci, O.
Taking advantage of the angular momentum of the rotating gyroscope, gyrostabilizer systems are expected to become more widely actualized as they provide an effective means of motion control with several significant advantages for various structures. In this paper, a symmetric gyro with coupling to the tip mass of a column mounted on a vibrating base is considered. The non-linear motions of the gyro-column system and the equations of motion for the system are derived following energy (Lagrange) based approaches and examples provided. On the other hand, the effect of the angular velocity of the gyroscope is studied, and it is shown that the angular velocity (spin velocity) Omega of gyroscope has a significant effect on the behavior of the dynamic motion. It is also shown how the damper and spring due to the motion between the suporting gimbal and tip mass influence the dynamic behavior of the gyroscope. It was concluded that the numerical investigations of this combined system has not been investigated up to the present time. (C) 2015 The Authors. Published by Elsevier Ltd.
AtıfWoS3OpenAlex9
İncele - EditoryalYalnız künye2024Scopus SJRQ2A rare case of intraosseous calcaneal lipoma with calcific and cystic components
Tonkaz, Gokhan; Akdeniz, Cemre; Tonkaz, Mehmet; Tonkaz, Duygu Erkal; Bekci, Tumay
AtıfWoS1OpenAlex1
İncele - EditoryalAçık Erişim2024Scopus SJRQ3A rare case: cerebral air embolism causing stroke after lung cancer ablation
Tonkaz, Mehmet; Tonkaz, Duygu Erkal; Tonkaz, Gokhan
- MakaleAçık Erişim2026An ergogenic approach to enhancing performance in archery: the acute effects of caffeine
Türker, Ustun; Ates, Zeynep Hazal; Görgülü, Mumine; Kiyici, Fatih; Bayrakdaroglu, Serdar
Background and Study Aim Ergogenic aids are widely used to enhance exercise performance and training adaptations. Among these, caffeine is recognized for its stimulatory effects on the central nervous system and neuromuscular function. Despite their widespread use, the relative effectiveness of such aids in improving performance in precision-based target sports such as archery remains a matter of practical interest. This study aimed to examine the effects of acute caffeine supplementation on shooting performance in university-level archers. Material and Methods A total of 12 licensed university archers (mean age: 22.92 +/- 2.11 years) participated in this study. A single-group pretest-posttest experimental design was employed. Participants completed two laboratory sessions separated by 72 hours under standardized conditions. In each session, anthropometric and hearing assessments were conducted. This was followed by the ingestion of 200 mg of caffeine. After a 60-minute absorption period, archers performed shooting tests at 18 meters. The protocol included practice trials and 10 sets of scoring shots. Data were analyzed using paired-samples t-tests and repeated-measures ANOVA. These methods accounted for within-subject variability across sets. Statistical significance was set at p < .05. Results Posttest scores were consistently higher than pretest scores across most sets. Statistically significant improvements were observed in Sets 2, 3, 4, 6, 8, 9, and 10 (p < .05). Sets 1, 5, and 7 showed nonsignificant differences. Overall performance increased significantly from 6.61 +/- 1.20 to 8.33 +/- 0.39 (p < .001), with a large effect size (Cohen's d = 1.90; eta 2 = .50). Repeated-measures ANOVA revealed a significant main effect of condition (p < .001). No significant set or interaction effects were found. This indicates that performance improvements were consistent across shooting sets. Conclusions Acute caffeine supplementation was associated with improved shooting performance in university-level archers. The findings suggest that caffeine may have potential as an ergogenic aid in precision-oriented sports requiring sustained attention and performance consistency. However, the results should be interpreted with caution due to methodological limitations. These include the absence of a control condition and the small sample size. Further randomized placebo-controlled studies are needed to confirm and extend these findings.
- MakaleYalnız künye2026Scopus SJRQ2Shared burdens: An Interpretative Phenomenological Analysis of couples facing infertility
Muslu, Ozge Nur; Uluç, Sait
This study explores the psychological and emotional impacts of infertility treatments on couples. Utilizing Interpretative Phenomenological Analysis, this qualitative research delves into the shared experiences of five couples undergoing fertility treatments, uncovering the deep-seated personal and relational dynamics of their journeys. Three key themes were identified: From Hope to Exhaustion: Navigating the Emotional Rollercoaster of Treatment, Redefining Togetherness: Making Sense of Infertility as a Couple, and Networks of Care: Negotiating Support Within and Beyond the Couple. Study explores how couples undergoing in vitro fertilization construct shared meaning around their experiences and how the process shapes their relational and psychological dynamics. This study adopts a couple-based interpretative phenomenological approach to reveal how partners co-construct meaning, manage shared distress, and experience relational growth during infertility treatment. It offers new insights into the dyadic processes that foster resilience amid infertility.
- MakaleYalnız künye2012Scopus SJRQ3Isolated Hemothorax Following Thoracic Trauma: Analysis of 57 Cases
Çobanoglu, Ufuk; Melek, Mehmet; Kara, Volkan; Mergan, Duygu
Aim: The aim of this study was to review cases with isolated hemothorax after thoracic trauma, to assess the diagnostic and treatment methods, and to discuss the determining factors of morbidity and mortality. Material and Method: A total of 57 patients were examined retrospectively. All patients underwent tube thoracostomy and underwater seal as the initial treatment approach. Emergency thoracotomy was performed on cases with continuing drainage from the chest tube, expanding hemothorax on the posteroanterior (PA) chest x-ray, and with hemodynamic instability. Result: Hemothorax occurred as a result of penetrating trauma in 31 (54.38%) and due to blunt trauma in 26 (45.61%) cases. Of the cases, 49 (85.96%) underwent tube thoracostomy drainage. All the 8 cases (14.03%) that underwent emergency thoracotomy had penetrating trauma. Mortality occurred in one patient (1.75%) who had penetrating trauma and who underwent emergency thoracotomy. The morbidity rate in patients with blunt trauma was significantly higher than those with penetrating trauma (p<0.0001). Discussion: Accurate diagnosis and appropriate surgical intervention in cases with traumatic hemothorax is essential for reducing the morbidity and mortality. Chest tube insertion and underwater seal application should be the initial treatment modality and successful in most cases. Emergency thoracotomy is life-saving in indicated patients. The need for thoracotomy is higher in isolated hemothorax due to penetrating chest trauma.
AtıfWoS3OpenAlex2İncele - MakaleYalnız künye2016The Relationship Between Female Labor Force Participation and Labor Productivity: Panel Data Analysis
Koyuncu, Julide Yalcinkaya; Yilmaz, Rasim; Ünver, Mustafa
We examine the relationship between various indicators of female labor force participation and labor productivity. We test the hypothesis that labor productivity boosts as the female employment increases by exploiting a panel data set including the period 1985 to 2010 and 111 countries and using three labor productivity indicators and three female labor force participation indicators. We identified a positive correlation between female labor force participation indicators and labor productivity. This finding is statistically significant and valid for three different productivity indicators and three different female labor force participation indicators. Thus, the results suggest that female labor force participation increases labor productivity, controlling for other factors that may contribute to labor productivity.
AtıfWoS1TR Dizin1
İncele - MakaleAçık Erişim2017Scopus SJRQ4SCREENING FOR ABDOMINAL AORTIC ANEURYSM IN GERIATRIC POPULATION
Karakus, Ali; Tasin, Veyis; Kartal, Ismail; Kuvandik, Guven
Aim: An abdominal aortic aneurysm (AAA) is uncommon in people. Male gender and smoking are the most important risk factors. AAA is a condition that may be fatal when diagnosis is delayed This study aimed to emphasize the necessity for screening due to four fatal cases with abdominal aortic aneurysm in a genatric population. Material and Method The study included 320 patients from a nursing home and an emergency department The diameters of abdominal aortas were measured and assessed far risk factors. Results: Of the patients, 232 (72.5% were male and the mean age was 75.65 +/- 7.76 (range: 62-95 years). Hypertension was the most frequent risk factor determined. Mean aortic diameter was found as 18.87 +/- 2.74 mm (range 15-26 mm) No significant associations were detected among risk factors, age groups, and aortic diameter Four cases with abdominal aortic aneurysm died. Discussion AM is the most frequently seen aneurysm among true aneurysms. Major risk factors for AAA include male gender. smoking history. and age >65 years. In advanced ages, particularly in men, screening for AAA reduced deaths caused by rupture. The patients should be assessed for surgical intervention by Taking risk factors into consideration. Large-scale screening studies can reduce risk for mortality.
- BildiriYalnız künye2018Scopus SJRQ3Comparison of Asphalt and Concrete Pavement Solar Reflectance
Akpinar, Muhammet Vefa; Sevin, Sedat
AtıfWoS5OpenAlex5İncele - MakaleAçık Erişim2017Scopus SJRQ2Regionalisation of discharges having certain exceedance probabilities and Eastern Black Sea Basin sample
Saka, Fatih; Yüksek, Omer
In many of water engineering studies, it is necessary to determine the amount of water or the probability of discharge at a certain value. However, current discharge measurements are limited and located in discharge gauging stations (DGS). Flow duration curves (FDC) belonging to each DGS can be obtained, but it is necessary to estimate discharge values of the areas having no or insufficient discharge data. For this purpose, studies based on the regionalization of discharge values can be applied. In this study, discharge values of 39 DGS located on Eastern Black Sea Basin in Turkey, and temperature and precipitation of weather stations in the region have been obtained. Drainage areas have been determined. Total annual precipitation and temperature values of DGS have been obtained by using Thiessen method. Values having 20%, 30%, 50%, and 90% exceedance probabilities of annual FDC, have also been correlated with basin characteristics using 10-year average daily discharges. Drainage area, drainage density and mean slope of tributary values were chosen as topographic; and mean annual precipitation height and annual temperature values chosen as climatic parameters. As a result, in the ungauged areas, 20%, 30%, 50%, and 90% exceedance probabilities of annual FDC have been estimated by some basin properties and the results were examined.
AtıfWoS4OpenAlex6İncele - MakaleAçık Erişim2021Effect of precautionary and normalization steps on course of COVID-19 pandemic in Turkey
Bostan, Sedat; Agac, Gokhan; Sahinöz, Saime
Aim: The COVID-19 pandemic began in China and has now spread across the whole world, and many countries such as Turkey are still fighting against this pandemic. The aim of this study was to investigate the impact of precautionary and normalization steps taken by the Turkish government on the number of confirmed cases, current cases, and deaths due to the COVID-19 in Turkey. Materials and Methods: The study used exponential regression models to estimate the number of confirmed cases, deaths, and current cases. The study data were collected from the Turkish Ministry of Health, Turkish Ministry of Internal Affairs, and the national public broadcaster of Turkey. Results: The precautions taken during the COVID-19 pandemic have caused the exponentially increasing number of cases to be brought under control and to decrease exponentially. The normalization steps taken paused the exponential decrease in the number of cases and caused the number of cases to remain flat during the summer months and then rise again. If the normalization steps were not implemented and the precautions taken continued in the same way, it was calculated that the numbers of COVID-19 current cases would be reset on June 26, 2020. The total number of deaths would remain at 4423 and the total number of confirmed cases would be 150586. Discussion: As a result, the impact of precautionary and normalization steps on the course of the COVID-19 pandemic was examined. It has been observed that the impact of these steps on the pandemic is exponential. The results provide guidelines for health authorities and administrators to take necessary precautions.
AtıfWoS1OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ3DIAGNOSTIC CHALLENGE OF PRIMARY COLONIC POORLY COHESIVE ADENOCARCINOMA EXHIBITING GASTRIC-TYPE IMMUNOHISTOCHEMISTRY PROFILE AND FOCAL SIGNET-RING DIFFERENTIATION
ISSiN, Gizem; Tok, Merve; ÇAgATAY, Diren Vuslat; Gökçe, Oruc Numan; Aytekin, Faruk Onder
Colorectal adenocarcinoma infrequently exhibits a diffuse, poorly cohesive architecture and a gastric-type immunophenotype, closely resembling diffuse-type gastric carcinoma and posing a formidable diagnostic challenge. This report describes a 65-year-old woman who presented with non-specific abdominal discomfort and was found by colonoscopy to have a 6.5 cm ulceroinfiltrative lesion in the hepatic flexure. Histologically, the tumor comprised discohesive cells with focal signet-ring morphology, accompanied by extensive lymphovascular and perineural invasion, necrosis, and a marked peritumoral lymphoid response. Immunohistochemical analysis demonstrated a gastric-type profile (CK7+, CK20-, SATB2-, CDX2 weak/focal, MUC5AC+, MUC2-), whereas panels excluding breast, urothelial, M & uuml;llerian, neuroendocrine, and hematolymphoid differentiation were uniformly negative. Comprehensive imaging and endoscopic evaluation excluded an extra-colonic primary malignancy/ carcinoma. Mismatch repair testing revealed loss of MLH1/PMS2 expression with preserved MSH2/MSH6. This case underscores that, in such uncommon colorectal variants, reliance on immunophenotype alone may mislead, and that definitive diagnosis necessitates integrated clinicopathologic correlation, exhaustive sampling, and exclusion of alternative primaries/primary malignancies/carcinomas to confirm a primary colonic poorly cohesive adenocarcinoma with focal signet-ring differentiation.
AtıfOpenAlex1İncele - MakaleYalnız künye2011Scopus SJRQ1Determination of Lactic Microflora of Kefir Grains and Kefir Beverage by Using Culture-Dependent and Culture-Independent Methods
Kesmen, Zulal; Kacmaz, Nazife
In this study, we investigated the bacterial compositions of kefir grains and kefir beverages collected from different regions of Turkey by using culture-independent and culture-dependent methods. In the culture-independent detection, 10 different species of bacteria were detected in total by using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis of the 16S rRNA gene V3 region. Among these species, Lactobacillus kefiranofaciens was the most dominant one in the kefir grains, while Lactococcus lactis was found to be significantly prevalent in the kefir beverages. In the culture-dependent detection, the primary differentiation and grouping of the isolates from kefir beverages and kefir grains were performed using repetitive sequence-based PCR (rep-PCR) fingerprinting, and the results were validated by 16S rDNA full-length sequencing. According to the results of culture-dependent methods, the most frequently isolated species were L. lactis, Leuconostoc mesenteroides, and Lactobacillus kefiri, respectively. Only 3 species, which are L. lactis, Lactobacillus acidophilus, and Streptococcus thermophilus, were detected with both culture-dependent and culture-independent methods. This study showed that the combination of both methods is necessary for a detailed and reliable investigation of microbial communities in kefir grains and kefir beverages. Practical Application Due to their artisan- and region-dependent microflora, kefir products can be a source of interesting lactic acid bacteria, either new taxa or strains with specific functional properties, which might be used for the development of new starter cultures and innovative food products. Therefore, an increasing demand exists for new strains that show desirable effects on the product characteristics Artisan dairy products are a candidate source of such microorganisms. For this reason, in this study, the bacterial compositions of kefir grains and kefir beverages obtained from different regions of Turkey were studied using culture-dependent and culture-independent molecular methods.
AtıfWoS86OpenAlex104İncele - EditoryalYalnız künye2012Scopus SJRQ3An unusual clinical state: atrial fibrillation due to mad-honey intoxication
Kalkan, Asim; Gökçe, Mustafa; Memetoglu, Mehmet Erdem
AtıfWoS7OpenAlex8İncele - MakaleYalnız künye2018COMPARISON OF FEM SOLUTION WITH ANALYTICAL SOLUTION OF CONTINUOUS AND DISCONTINUOUS CONTACT PROBLEM
Kaya, Yusuf; Polat, Alper; Özsahin, Talat Sukru
The continuous and discontinuous contact problem of a homogeneous layer loaded with three rigid flat blocks and resting on the elastic semi-infinite plane was investigated in this study by using the finite element method (FEM). All surfaces are assumed to be frictionless. The homogenous layer was loaded by means of three rigid flat blocks whose external loads are Q and P (per unit thickness in z direction). Two dimensional finite element analysis of the problem was performed using ANSYS package program. Analyzes were performed for loading conditions which are Q=P, Q=2P, Q=4P, Q=8P and Q=10P, and different values of block widths, distances between blocks and shear modulus. The initial separation loads and initial separation distances (lambda(cr), chi(cr)) between the homogeneous layer and the elastic semi-infinite plane were determined for continuous contact condition. The length of the separation zone was obtained for discontinuous contact condition. In addition to these, normal stress distributions between the layer and the semi-infinite plane were determined for continuous and discontinuous contact conditions. As a result of the study, the analytical results, and the results of the finite element method were shown by comparing as graphs and tables.
AtıfWoS5İncele - MakaleYalnız künye2024Scopus SJRQ3Efficacy of fat quantification methods used in MRI to distinguish between normal, benign, and malignant bone marrow pathologies in children
Tonkaz, Duygu Erkal; Ozpar, Rifat; Tonkaz, Mehmet; Yazici, Zeynep
Background Fat quantification methods in magnetic resonance imaging (MRI) have been studied to differentiate bone marrow pathologies in adult patients; however, scarce literature is available in pediatric patients.Purpose To evaluate the efficacy of the T1 signal intensity value (T1-SIV), out-of-phase/in-phase signal ratio (OP/IP SR), and fat fraction (FF) to differentiate between normal, benign, and malignant pathological processes.Material and Methods A total of 48 pediatric patients with lumbar and pelvic MRI were classified into three groups according to bone marrow pathology (group 1, normal; group 2, benign pathology/reconversion; group 3, malignant). The efficacy of T1-SIV, OP/IP SR, and FF values in differentiating these pathologies was evaluated using Kruskal-Wallis or analysis of variance and followed by Bonferroni or Dunn-Bonferroni tests. Cutoff values for malignant infiltration were defined using ROC analysis.Results Although these values were significantly different in all three groups (P = 0.001-0.008), this difference was not sufficient to discriminate between all groups. Subgroup analyses showed significant differences in T1-SIV between groups 1-3, in OP/IP SR between groups 1-3, 2-3, and 1-2, in FF between groups 1-2 and 1-3 in various regions (P = 0.001-0.049). Cutoff values had a sensitivity and specificity of 90%-100% for OP/IP SR and FF.Conclusion T1-SIV, OP/IP SR, and FF may potentially distinguish normal from pathological bone marrow. OP/IP SR and FF values detected malignant infiltration with high sensitivity and specificity in this study. However, only OP/IP SR may significantly differentiate benign and malignant bone marrow pathologies which needs to be confirmed in the future study with a larger patient population.
AtıfWoS3OpenAlex4İncele - EditoryalYalnız künye2024Scopus SJRQ2A rare lesion of the clivus: Neuroenteric cyst
Tonkaz, Gokhankhan; Kaya, Abdulkadir; Tonkaz, Mehmet; Tonkaz, Duygu Erkal
- BildiriYalnız künye2018Scopus SJRQ3Urban Heat Island Effects of Concrete Road and Asphalt Pavement Roads
Akpinar, Muhammet Vefa; Sevin, Sedat
AtıfWoS5OpenAlex4İncele - MakaleAçık Erişim2019An Empirical Study on Alcohol Participation and Consumption Decision in Turkey
Ipek, Egemen
In this study, households' alcohol participation and consumption decision structures and the effect of socioeconomic factors influencing on these decisions are analyzed by using Tobit and double-hurdle models with Household Budget Survey data in Turkey. This study shows that alcohol participation and consumption decision are taken as independently from each other and sequentially based on the goodness of fit tests of the model. When the effects of household demographic variables on alcohol consumption decisions are examined, it is obtained that having a child has a negative effect on alcohol participation decision and consumption of cigarette has a positive effect on alcohol participation decision. Furthermore, household income level has a positive effect on both alcohol participation and consumption decision.
AtıfOpenAlex8TR Dizin6İncele - MakaleAçık Erişim2024Glass Ceiling Syndrome: A Perspective of Women Working In Health Institutions
Turan Kurtaran, Ayten; Aydin, Arzu; Yesildag, Ahmet Y.
Background and Purpose: Although women constitute the majority of the workforce in the healthcare sector, the number of representations in management positions needs to be increased. This study aimed to determine female health workers' glass ceiling syndrome perception levels and examine socio-demographic variables' effect on this level. Design/methodology/approach: The research sample consists of 708 female healthcare professionals who work in six public hospitals. Perceptions were measured using the 42-item Glass Ceiling Perception scale. Measurements were made on a 5-point Likert scale ranging from 0 to 4. Findings: It was found that the glass ceiling syndrome perception levels of female healthcare professionals were neutral (1.94). It has been determined that female healthcare professionals with a high level of education, doctors and nurses, those between the ages of 26-35, those who work in medical units, and those with a child have higher perception levels of glass ceiling syndrome.
AtıfWoS4OpenAlex5TR Dizin1İncele
