Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14517/19

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Citation Count: 5
Academic domains as political battlegrounds: A global enquiry by 99 academics in the fields of education and technology
(Sage Publications Ltd, 2017) Al Lily, Abdulrahman E.; Foland, Jed; Stoloff, David; Gogus, Aytac; Erguvan, Inan Deniz; Awshar, Mapotse Tome; Schrader, P. G.; Eğitim Bilimleri / Educational Sciences
This article theorizes the functional relationship between the human components (i.e., scholars) and non-human components (i.e., structural configurations) of academic domains. It is organized around the following question: in what ways have scholars formed and been formed by the structural configurations of their academic domain? The article uses as a case study the academic domain of education and technology to examine this question. Its authorship approach is innovative, with a worldwide collection of academics (99 authors) collaborating to address the proposed question based on their reflections on daily social and academic practices. This collaboration followed a three-round process of contributions via email. Analysis of these scholars' reflective accounts was carried out, and a theoretical proposition was established from this analysis. The proposition is of a mutual (yet not necessarily balanced) power (and therefore political) relationship between the human and non-human constituents of an academic realm, with the two shaping one another. One implication of this proposition is that these non-human elements exist as political actors', just like their human counterparts, having agency' - which they exercise over humans. This turns academic domains into political (functional or dysfunctional) battlefields' wherein both humans and non-humans engage in political activities and actions that form the identity of the academic domain. For more information about the authorship approach, please see Al Lily AEA (2015) A crowd-authoring project on the scholarship of educational technology. Information Development. doi: 10.1177/0266666915622044.
Citation Count: 11
Accuracy of Digital Impressions Obtained Using Six Intraoral Scanners in Partially Edentulous Dentitions and the Effect of Scanning Sequence
(Quintessence Publishing Co inc, 2021) Diker, Burcu; Tak, Onjen
Purpose: To compare the accuracy of six intraoral scanners in two different partially edentulous maxillary models and to evaluate the effect of scanning sequence on accuracy. Materials and Methods: Maxillary Kennedy Class I and Class IV situations were used as reference models. The reference datasets were obtained by scanning the models using a highly accurate industrial scanner (ATOS Core 80, GOM). The following six intraoral scanners were evaluated: Trios 3 (3Shape), iTero Element 2 (Align Technology), Emerald (Planmeca), CEREC Omnicam (Dentsply Sirona), CEREC Primescan (Dentsply Sirona), and Virtuo Vivo (Dental Wings). A total of 120 scans from both models were obtained using the six intraoral scanners and divided into two groups based on scanning sequence. Accuracy was evaluated by deviation analysis using 3D image processing software (Geomagic Studio 12, 3D Systems). Kruskal Wallis and Mann-Whitney U tests were performed (P <= .05) for statistical analysis. Results: There were significant differences in the accuracy of digital impressions among intraoral scanners and scanning sequences. The trueness of the Trios scanner and the precision of the Trios, Primescan, and iTero scanners were significantly higher than for the other scanners. The Emerald had the lowest accuracy among the six intraoral scanners tested. Accuracy was affected by scanning sequence when using the Virtuo Vivo, Emerald, Primescan, and iTero. Conclusion: In Kennedy Class I and Class IV partially edentulous cases, it is useful to consider that the intraoral scanner used may affect the accuracy of the digital impression.
Citation Count: 5
The acute effects of different intensity whole-body vibration exposure on muscle tone and strength of the lower legs, and hamstring flexibility: A pilot study
(Human Kinetics Publishers Inc., 2021) Saldiran,T.; Atici,E.; Rezaei,D.A.; Öztürk,Ö.; Uslu,B.; Özcan,B.A.; Okudan,B.; Fizyoterapi ve Rehabilitasyon / Physiotherapy and Rehabilitation
Context: The research on the change in properties of the lower leg muscles by different intensity sinusoidal vertical whole-body vibration (SV-WBV) exposures has not yet been investigated. Objective: The purpose of this study was to determine effect of a 20-minute different intensity SV-WBV application to the ankle plantar flexor and dorsiflexor muscles properties and hamstring flexibility. Design: Prospective preintervention-postintervention design. Setting: Physiotherapy department. Participants: A total of 50 recreationally active college-aged individuals with no history of a lower leg injury volunteered. Interventions: The SV-WBV was applied throughout the session with an amplitude of 2 to 4 mm and a frequency of 25 Hz in moderate-intensity vibration group and 40 Hz in a vigorous-intensity vibration group. Main Outcome Measures: The gastrocnemius and tibialis anterior muscle tone was assessed with MyotonPRO, and the strength evaluation was made on the same lower leg muscles using hand-held dynamometer. The sit and reach test was used for the lower leg flexibility evaluation. Results: The gastrocnemius muscle tone decreased on the right side (d=0.643, P=.01) and increased on the left (d = 0.593, P=.04) when vigorous-intensity vibration was applied. Bilateral gastrocnemius muscle strength did not change in both groups (P > .05). Without differences between groups, bilateral tibialis anterior muscle strength increased in both groups (P < .01). Bilateral gastrocnemius and tibialis anterior muscle tone did not change in the moderate-intensity vibration group (P > .05). Flexibility increased in both groups (P < .01); however, there was no statistically significant difference between the groups (d = 0.169, P = .55). Conclusions: According to study results, if SV-WBV is to be used in hamstring flexibility or ankle dorsiflexor muscle strengthening, both vibration exposures should be preferred. Different vibration programs could be proposed to increase ankle plantar flexor muscle strength in the acute results. Vigorous-intensity vibration exposure is effective in altering ankle plantar flexor muscle tone, but it is important to be aware of the differences between the lower legs. © 2021 Human Kinetics, Inc.
Citation Count: 0
Addressing urinary incontinence by gender: a nationwide population-based study in Turkiye
(Bmc, 2023) Yavuz, Melike; Etiler, Nilay
BackgroundUrinary incontinence (UI), which usually occurs in women but affects both sexes, is a significant public health challenge. This study aims to comprehensively investigate the prevalence and determinants of UI in men and women, considering gender-specific factors.MethodsThe study performed a secondary analysis on data obtained from 13,383 individuals surveyed in the 2019 Turkish Health Survey, providing a representation of the Turkish population. The dataset included sociodemographic and health-related variables like UI, body mass index (BMI), physical activity, smoking, and chronic diseases-statistical analysis employed chi-square tests and gender-stratified logistic regression models to identify UI-associated factors.ResultsOur results showed that UI affected 8.8% of the population, with a striking gender disparity. Women had a notably higher prevalence at 11.2%, while men had a lower rate of 5.5%. Importantly, this gender gap narrowed with age. For example, in the 34-44 age group, the female/male ratio was 6.9, but it decreased to 1.4 in the 65-74 age group. Marital status and employment status played significant roles. Separated, divorced, or widowed individuals, particularly women, had the highest prevalence at 19.3%. Employment status influenced UI prevalence, with employed men having the lowest rate (2.1%), while retired women faced the highest rate (15.0%). Higher BMI, especially in obese individuals, significantly raised UI prevalence, reaching 7.9% for men and 15.8% for women. Physical inactivity, notably in women (17.0%), and prolonged sedentary hours (13.9%) were associated with higher UI rates. Former smokers, especially women (15.9%), had a notable impact on UI. Poor perceived health and chronic conditions like Chronic Obstructive Pulmonary Disease (COPD), hypertension, and diabetes were significantly associated with higher UI prevalence. Logistic regression analysis revealed that age, education, perceived health status, COPD, and diabetes were significant factors associated with UI in both sexes, while in women, BMI, physical activity, and smoking also played notable roles.ConclusionsThis extensive UI study has unveiled notable gender disparities and determinants. Notably, these disparities decrease with age, underlining UI's changing nature over time. Modifiable factors impact women more, while non-modifiable factors are linked to men. The study underscores the importance of tailoring healthcare strategies to address UI based on gender.
Citation Count: 2
Adhesion of conventional and self-adhesive resin cements to indirect resin composite using different surface conditioning methods
(Taylor & Francis Ltd, 2017) Cilingir, Aylin; Bilhan, Hakan; Cilingir, Altug; Gomec, Yavuz; Ozcan, Mutlu
This study evaluated the adhesion of conventional and self-adhesive resin cements to indirect resin composite (IRC) using different surface conditioning methods. Cylindrical IRC specimens (N=192) were randomly assigned to four surface conditioning methods (n=8 per group): (a) Control group, (b) Hydrofluoric acid, (c) Tribochemical silica-coating, and (d) 50m Al2O3 air-abrasion. Specimen surfaces were finished using silicon carbide papers up to 600 grit under water irrigation, rinsed and dried. Direct composite blocks were bonded to IRC specimens using three conventional resin cements (Multilink, Panavia F2.0, and Resicem) and three self-adhesive resin cements (RelyX U100, Gcem, Speed Cem). Specimens were subjected to shear bond strength test in a Universal Testing Machine (0.5mm/min). Failure types were categorized as mixed, adhesive and cohesive. Data were analyzed using 2-way ANOVA and Tukey's tests. Two-parameter Weibull modulus, scale (m) and shape (0) were calculated. The bond strength results (MPa) were significantly affected by the surface conditioning method (p<0.0001) and cement type (p<0.001). For Panavia F2.0, Resicem, air-abrasion with 50m Al2O3 significantly increased the results (22.6 +/- 6.5, 26.2 +/- 6.5, respectively) compared to other conditioning methods (13.6 +/- 1.4-21.9 +/- 3.1) but for Multilink, hydrofluoric acid etching (20.5 +/- 3.5) showed significantly higher results (p<0.01). For the self-adhesive resin cements, air-abrasion with 50m Al2O3 significantly increased the results compared to other conditioning methods, except for RelyX U100 (p<0.05). After air-abrasion with Al2O3, Gcem, (11.64), RelyX U100 (9.05), and SpeedCem (8.29) presented higher Weilbul moduli. Exclusively cohesive failure in the IRC was observed with RelyX U100 and Speedcem after Al2O3 air-abrasion.
Citation Count: 1
Alterations in right ventricular mechanics in patients with Behcet's disease
(Springer, 2022) Dinc Asarcikli, Lale; Saritas, Fatih; Guvenc, Tolga Sinan; Can, Fatma; Sert, Sena; Cetin Guvenc, Rengin; Unal, Sennur
Manifest myocardial involvement is somewhat rare in patients with Behcet's disease (BD), although echocardiographic studies suggest that subclinical alterations in left ventricular (LV) contractility is rather common. Data on right ventricular (RV) involvement in BD is rather scarce. This study aims to determine whether RV systolic performance is affected in BD patients, and to understand the clinical and echocardiographic correlates of RV contractility in these patients. Forty-five patients who fulfilled criteria for BD and 45 age and gender matched controls were enrolled. All participants underwent a comprehensive echocardiographic examination, including deformation imaging, to characterize RV mechanics. Conventional morphologic and echocardiographic indicators of RV morphology and function were not different between groups, but RV apical strain and RV free wall strain (FWS) were significantly lower in BD patients as compared to the controls (P < 0.001 and P = 0.02, respectively). The only significant correlates of FWS were tricuspid regurgitation velocity and related indices in healthy controls, while FWS correlated with LV global longitudinal strain (GLS), morphologic measures of left and right atria and ventricles, and with conventional measures of right ventricular contractility. The relationship between FWS and GLS remained statistically significant after adjusting for other clinical and echocardiographic parameters (beta = 0.379, P = 0.01). In patients with BD, there is a subclinical alteration in RV contractility and the degree of alteration in the RV systolic performance paralleled that of LV. Thus, present results support the presence of RV involvement in these patients.
Citation Count: 0
Amelioration of propionic acid-induced autism spectrum disorder in rats through dapagliflozin: The role of IGF-1/IGFBP-3 and the Nrf2 antioxidant pathway
(Pergamon-elsevier Science Ltd, 2024) Erdogan, Mumin Alper; Nesil, Pemra; Altuntas, Ilknur; Sirin, Cansin; Uyanikgil, Yigit; Erbas, Oytun
The biological effects of dapagliflozin, a sodium-glucose cotransporter-2 (SGLT2) inhibitor, reveal its antioxidant and anti-inflammatory properties, suggesting therapeutic benefits beyond glycemic control. This study explores the neuroprotective effects of dapagliflozin in a rat model of autism spectrum disorder (ASD) induced by propionic acid (PPA), characterized by social interaction deficits, communication challenges, repetitive behaviors, cognitive impairments, and oxidative stress. Our research aims to find effective treatments for ASD, a condition with limited therapeutic options and significant impacts on individuals and families. PPA induces ASD-like symptoms in rodents, mimicking biochemical and behavioral features of human ASD. This study explores dapagliflozin's potential to mitigate these symptoms, providing insights into novel therapeutic avenues. The findings demonstrate that dapagliflozin enhances the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway and increases levels of neurotrophic and growth factors such as brainderived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and insulin-like growth factorbinding protein-3 (IGFBP-3). Additionally, dapagliflozin reduces pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha) and interleukin-17 (IL-17), and decreases the oxidative stress marker malondialdehyde (MDA). Dapagliflozin's antioxidant properties support cognitive functions by modulating apoptotic mechanisms and enhancing antioxidant capacity. These combined effects contribute to reducing learning and memory impairments in PPA-induced ASD, highlighting dapagliflozin's potential as an adjunctive therapy for oxidative stress and inflammation-related cognitive decline in ASD. This study underscores the importance of exploring new therapeutic strategies targeting molecular pathways involved in the pathophysiology of ASD, potentially improving the quality of life for individuals affected by this disorder.
Citation Count: 11
Analysis of cable structures through energy minimization
(Techno-press, 2017) Toklu, Yusuf Cengiz; Bekdas, Gebrail; Temur, Rasim
In structural mechanics, traditional analyses methods usually employ matrix operations for obtaining displacement and internal forces of the structure under the external effects, such as distributed loads, earthquake or wind excitations, and temperature changing inter alia. These matrices are derived from the well-known principle of mechanics called minimum potential energy. According to this principle, a system can be in the equilibrium state only in case when the total potential energy of system is minimum. A close examination of the expression of the well-known equilibrium condition for linear problems, P=K Delta, where P is the load vector, K is the stiffness matrix and A is the displacement vector, it is seen that, basically this principle searches the displacement set (or deformed shape) for a system that minimizes the total potential energy of it. Instead of using mathematical operations used in the conventional methods, with a different formulation, meta-heuristic algorithms can also be used for solving this minimization problem by defining total potential energy as objective function and displacements as design variables. Based on this idea the technique called Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is proposed. The method has been successfully applied for linear and non-linear analyses of trusses and truss-like structures, and the results have shown that the approach is much more successful than conventional methods, especially for analyses of nonlinear systems. In this study, the application of TPO/MA, with Harmony Search as the selected meta-heuristic algorithm, to cables net system is presented. The results have shown that the method is robust, powerful and accurate.
Citation Count: 2
An analysis of economic benefits of the Southern Gas Corridor
(Taylor & Francis inc, 2016) Hasanov, Mubariz
In this paper, we examine economic benefits and viability of the Southern Gas Corridor (SGC) for supplying natural gas to Europe from the Caspian Basin. In particular, we examine what will be the effects of natural gas supplies from the Caspian Basin on import prices and social welfare of the EU countries and Turkey. We also analyze profits of exporters and oil companies engaged in production and transportation of natural gas to Europe. We find that the SGC will reduce import prices and increase social welfare in the EU and Turkey. Our results also suggest that the SGC will generate noteworthy profits for exporters and oil companies engaged in the project and thus bring significant economic gains to all parties.
Citation Count: 4
Analyzing the effects of import liberalization in the Turkish natural gas market
(Taylor & Francis inc, 2017) Hasanov, Mubariz
In this paper, we analyze the economic consequences of full import liberalization of the Turkish natural gas market. For this purpose, we build a simple game-theoretic model where exporters of natural gas may face supply constraints. We first derive equilibrium quantity and market price analytically with and without capacity constraints of the exporters. Then, we compute estimates of equilibrium quantity and prices using calibrated demand functions. Our results suggest that full market liberalization will bring huge economic gains to the Turkish consumers.
Citation Count: 1
Any Instrument in a Surgeon's Hand can be Fatal: Unusual Iliac Artery Injury in Lumbar Spinal Deformity Surgery
(Elsevier Science inc, 2020) Koban, Orkun; Akar, Ezgi; Ogrenci, Ahmet; Yilmaz, Mesut; Dalbayrak, Sedat
BACKGROUND: Vascular complications, which we rarely encounter during lumbosacral stabilization surgeries, can be life-threatening if they are not treated quickly. These arterial injuries occur during screw insertion. Our presentation with the common iliac artery injury during the decortication process in transverse processes with the "pedicle awl" will be the first case in the literature to our knowledge. CASE DESCRIPTION: Lumbosacral decompression and stabilization surgery was performed in a 57-year-old patient with L1-S1 spinal stenosis and scoliosis. After the stabilization process was completed, while decorticating the transverse processes with the pedicle awl, the tool fell to the paravertebral region, and then active arterial hemorrhage was observed at the surgical site. Hemostasis was achieved in the surgical field, but a rapid progressive drop was observed in the patient's blood pressure. The surgery was quickly terminated, and the patient was turned to the supine position. Vascular surgeons opened the abdomen with a midline laparotomy, and approximately 2600 mL hematoma was evacuated from the retroperitoneum. The 5-mm defect in the left common iliac artery was repaired by primary suturing. The patient had no problem in postoperative follow-up and was discharged on the 10th postoperative day. CONCLUSIONS: In these complications that we rarely encounter in lumbosacral stabilization surgeries, perioperative findings should be well evaluated, and rapid intervention should be made in cases in which vascular injury is considered. One must remember that every tool used during surgery can be dangerous even in an experienced hand.
Citation Count: 8
Association between blood pressure, inflammation and spirometry parameters in chronic obstructive pulmonary disease
(Korean Assoc internal Medicine, 2019) Arslan, Sulhattin; Yildiz, Gursel; Ozdemir, Levent; Kaysoydu, Erdal; Ozdemir, Bulent
Background/Aims: Many systems including the cardiovascular system (ischemic heart diseases, heart failure, and hypertension) may act as comorbidities that can be seen during the course of chronic obstructive pulmonary disease (COPD). Comorbidities affect the severity and prognosis of COPD negatively. Nearly 25% of patients with COPD die due to cardiovascular diseases. In this study, we aimed to evaluate the relationship between the blood pressure, inflammation, hypoxia, hypercapnia, and the severity of airway obstruction. Methods: We included 75 COPD patients in the study with 45 control cases. We evaluated age, sex, body mass index, smoking history, C-reactive protein levels, 24-hour ambulatory blood pressure Holter monitoring, arterial blood gas, and respiratory function tests of the patient and the control groups. Results: In COPD patients, the night time systolic, diastolic blood pressures and pulse per minute and the mean blood pressures readings were significantly elevated compared to the control group (p < 0.05). In the correlation analysis, night time systolic pressure was associated with all the parameters except forced expiratory volume in 1 second (FEV1%). Diastolic blood pressure was associated with pH and HCO3 levels. The mean night time, day time pulse pressures and 24-hour pulse per minute values were also associated with all the parameters except FEV1%. Conclusions: In this study we found that parameters of systolic and diastolic blood pressures and pulse pressures were significantly elevated in COPD patients compared to the control groups. Blood pressure was associated blood gas parameters and inflammation parameters in COPD patients. This, in turn, may cause understanding of the pathophysiology of COPD and its complications.
Citation Count: 2
Association between root taper and root proximity of single-rooted teeth with periodontitis: a cone-beam computed tomography based study
(Springer, 2022) Aykol-Sahin, Gokce; Arsan, Belde; Altan-Koran, Serpil Melek; Huck, Olivier; Baser, Ulku; Periodontoloji / Periodontology
This study aimed to determine the association between the root taper and proximity of single-rooted teeth with periodontitis using cone-beam computed tomography (CBCT). CBCT images of 362 single-rooted teeth from 37 patients were evaluated. This case-control study analyzed 17 participants with stage II and III periodontitis, (n = 161 teeth, periodontitis group) and 20 participants with healthy periodontium (n = 201 teeth, control group). Multiplanar reconstructions were used for proximity measurements, and cross-sectional images for calculating the angle of the root tapers. Root proximity, root length, and root taper were measured. Multivariate binary logistic regression analysis was used to determine association with periodontitis. In the periodontitis group, the upper lateral root-taper was 18.33 degrees +/- 3.25 degrees and was significantly higher when compared to the control group (p = 0.001). The root taper of the lateral incisor was associated with the diagnosis of periodontitis (p = 0.01) with an odds ratio of 1.541 according to regression analysis. Root length was also identified as a potential protective parameter. The risk of being diagnosed with periodontitis decreases when root length increases by 0.785 times (p = 0.043). Upper canines in the periodontitis group presented shorter root lengths (p = 0.039) and higher root tapers (p = 0.01). Also, mandibular canines were closer form adjacent teeth in the periodontitis group (p = 0.042). This study indicated that short-root and increased root-taper at specific teeth could be considered as risk indicators for periodontitis.
Citation Count: 19
Association Patterns in Open Data to Explore Ciprofloxacin Adverse Events
(Georg Thieme verlag Kg, 2015) Yildirim, P.; Bilgisayar Mühendisliği / Computer Engineering
Background: Ciprofloxacin is one of the main drugs to treat bacterial infections. Bacterial infections can lead to high morbidity, mortality, and costs of treatment in the world. In this study, an analysis was conducted using the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) database on the adverse events of ciprofloxacin. Objectives: The aim of this study was to explore unknown associations among the adverse events of ciprofloxacin, patient demographics and adverse event outcomes. Methods: A search of FDA AERS reports was performed and some statistics was highlighted. The most frequent adverse events and event outcomes of ciprofloxacin were listed, age and gender specific distribution of adverse events are reported, then the apriori algorithm was applied to the dataset to obtain some association rules and objective measures were used to select interesting ones. Furthermore, the results were compared against classical data mining algorithms and discussed. Results: The search resulted in 6 531 reports. The reports included within the dataset consist of 3 585 (55.8%) female and 2 884 (44.1%) male patients. The mean age of patients is 54.59 years. Preschool child, middle aged and aged groups have most adverse events reports in all groups. Pyrexia has the highest frequency with ciprofloxacin, followed by pain, diarrhoea, and anxiety in this order and the most frequent adverse event outcome is hospitalization. Age and gender based differences in the events in patients were found. In addition, some of the interesting associations obtained from the Apriori algorithm include not only psychiatric disorders but specifically their manifestation in specific gender groups. Conclusions: The FDA AERS offers an important data resource to identify new or unknown adverse events of drugs in the biomedical domain. The results that were obtained in this study can provide valuable information for medical researchers and decision makers at the pharmaceutical research field.
Citation Count: 4
Bonding strategies of resin cement to Er,Cr:YSGG lased dentin: micro-CT evaluation and microshear bond strength testing
(Sage Publications Ltd, 2016) Meric, Gokce; Tasar, Simge; Orhan, Kaan
Aims: Pretreatment of the tooth surface is essential for establishing effective micromechanical retention between it and the restoration. The purpose of this study was to evaluate the bond strength between the resin and the Er,Cr:YSGG laser irradiated dentin and to examine morphologic characterization of the dentin-resin interface. In addition, the study evaluated the quantity of opened and closed dentinal tubules. Subjects and methods: Thirty extracted human molars were sectioned into samples of 1 mm thickness. The samples were randomly assigned to two groups containing 15 specimens each. Surface treatments were not applied to the samples in the control group and the samples in the experimental group were irradiated with an Er,Cr:YSGG laser. Two resin cement samples were polymerized on the surface of each sliced dentin. The microshear bond strength (mu SBS) between dentin and cement (n = 30 for each group) was measured with a universal testing machine. The topography and morphology of the resin-dentin interface were evaluated by micro-CT (n = 20 for each group). The areas of closed tubular space, closed porosity, area of open tubular space, open porosity, total area of tubular space and fractal dimension were investigated by micro-CT. Statistical analysis used: The data for each parameter were analyzed by Shapiro-Wilk and Student's t test (p<0.05). Results: mu SBS values for control group were higher than experimental group. Dentin surfaces in the control group revealed less closed and more opened dentin tubules compared to the experimental group. Total area of tubular space was found to have decreased due to the laser ablation. There was no significant difference between the fractal dimensions of the control and experimental groups. Conclusions: The lased dentin surface was not favorable for the bonding mechanism due to alterations in the dentinal structure.
Citation Count: 1
Bound States of Light Hydrogen-Like Atoms and the Possibility of Cold Nuclear Transformations
(Walter de Gruyter Gmbh, 2018) Kholmetskii, A. L.; Yarman, T.; Enerji Sistemleri Mühendisliği / Energy Systems Engineering
We point out that numerous experimental facts dealing with the observation of nuclear transformations in a condensed matter at room temperature remain totally unexplained till date. In the present article we open up a principal way to understand such phenomena in the framework of pure bound field theory (PBFT) that we developed earlier (e.g. Kholmetskii AL. et al. Eur. Phys. J. Plus 2011;12633, Eur. Phys. J. Plus 2011;12635). In this theory, we explicitly take into account the non-radiating nature of the electromagnetic field of quantum bound particles in stationary states, which leads to the corresponding corrections of basic equations of atomic physics, with further elimination of the available subtle deviations between experimental and theoretical data in precise physics of light hydrogen-like atoms. In the present paper we have once more analysed the principal prediction of PBFT, which allows the existence of the second stationary energy state in the bound system "proton plus electron" (next to the usual hydrogen atoms). This new stationary state is characterised by the unusually small averaged radius of about 2 alpha(2)r(B) approximate to 5 fm (where r(B) is the Bohr radius, and a is the fine structure constant), and a huge (in the atomic scale) value of the binding energy about -255 keV. We named this bound system as the "neutronic hydrogen", because in many processes of its interaction with matter, it is practically indistinguishable from the neutron. The latter circumstance opens up the principal way to understand numerous puzzling facts of low-temperature nuclear synthesis.
Citation Count: 6
Calculation of gamma-ray buildup factors for some medical materials
(Emerald Group Publishing Ltd, 2022) Celen, Yonca Yahsi; Sarihan, Mucize; Almisned, Ghada; Tekin, Huseyin Ozan; Ekmekci, Ismail; Radyoterapi / Radiotherapy
In recent years, novel materials with protective qualities against ionizing radiation have been discovered. Important concepts include the continued use of X-rays for diagnosis and treatment, particularly in the radiological energy range, as well as the calculation of the radiation attenuation properties of such materials, the buildup factor and the attenuation coefficients. Radiation shielding is characterized by parameters such as the linear attenuation coefficient (cm(-1)), equivalent atomic number (Z(eq)), exposure buildup factor (EBF) and exposure absorption buildup factor (EABF). Radiation is often employed in the diagnosis and treatment of cancer and accurate calculation of the absorbed dosage during radiation treatment, which is one of the most popular cancer treatments. It relies on accurate modeling of the radiation beams administered to the patient and their interaction with the environment in which they are absorbed. In this research, the shielding characteristics of water, fat and bone related to human tissue are investigated. Using the Phy-X/PSD software, the equivalent atomic number (Z(eq)), EBF and EABF were determined.
Citation Count: 3
A Case Study to Assess the Sample Preparation Error in Pesticide Residue Analysis
(Springer, 2015) Omeroglu, Perihan Yolci; Ambrus, Arpad; Boyacioglu, Dilek; Majzik, Etelka Solymosne
In the scope of this study, pesticide residue distribution within a fruit and the possible error deriving from sample preparation step were demonstrated with the analysis of benomyl residues in peel, pulp, and seeds of papaya fruits treated post-harvest. Benomyl residue, measured as carbendazim, in corresponding sections of peel and pulp of papaya fruits ranged from 0.178 to 1.325 mg/kg and 0.025 to 0.087 mg/kg, respectively. Residue concentration decreased in a range between 41 and 83 % by peeling of papaya. All seeds contained residue value below limit of quantification. As the residues are unevenly distributed among the peel, pulp, and seed, pesticide residue analysis should be carried out accurately according to proper sample preparation protocol in peel, pulp, or in whole fruit and evaluated correctly taking into consideration the purpose of the analysis. The proportion of peel and pulp after their separation significantly affected the residues measured in the peel and pulp. It shows how peeling operation can affect the results and how important it is to remove the peel without significant portion of pulp attached to it. Thus, the selected test system could be well used to demonstrate the possible variability of measured residues depending on the uniformity of sample preparation.
Citation Count: 13
Changes in Aortic Pulse Wave Velocity and the Predictors of Improvement in Arterial Stiffness Following Aortic Valve Replacement
(Medical Tribune inc, 2017) Canturk, Emir; Cakal, Beytullah; Karaca, Oguz; Omaygenc, Onur; Salihi, Salih; Ozyuksel, Arda; Akcevin, Atif
Background: The interaction between valvular aortic stenosis (AS) and arterial stiffness, as well as the impact of aortic valve replacement (AVR) on arterial stiffness, remains unclear. In this study, we aimed to evaluate the degree of AS severity on non-invasive pulse wave velocity (PWV) measurements. We also searched whether the AVR procedure favorably affects PWV. Methods: In all, 38 patients undergoing AVR for chronic AS were included. The degree of aortic stiffness was measured with PWV at both baseline and 6 months after AVR. Improvement in aortic stiffness was defined as the absolute decrease in PWV at 6 months compared to the baseline value. Results: The study population had a mean age of 59 +/- 16 years, mean aortic gradient of 47.1 +/- 6.4 mmHg, and mean aortic valve area (AVA) index of 0.45 +/- 0.11 cm(2)/m(2). Baseline PWV values correlated positively with the mean aortic gradient (r = 0.350, p = 0.031) and negatively with the AVA index (r = -0.512, p = 0.001). The mean PWV improved in 20 patients (53%) and worsened in 18 patients (47%). The baseline New York Heart Association (NYHA) class (odds ratio [OR] = 1.023, 95% confidence interval [CI] = 1.005-1.041, p = 0.041) and AVA index (OR = 1.040, 96% CI = 1.023-1.057, p = 0.028) emerged as the independent predictors of improvement in PWV following AVR. Conclusion: The severity of AS was significantly associated with baseline PWV. In general, the mean PWV did not change with AVR. Baseline NYHA class and the AVA index independently predicted PWV improvement following AVR. Since the change in PWV after AVR was polarized based on the patients' characteristics, such as preoperative NYHA functional class or AVA index, further studies are needed to confirm clinical significance of PWV change following AVR in severe AS patients.
Citation Count: 2
Changes in Limbal Optical Coherence Tomography Angiography Outcomes in Patients With Overnight Contact Lens Wear
(Lippincott Williams & Wilkins, 2021) Ceran, Basak Bostanci; Ozates, Serdar; Arifoglu, Hasan Basri; Tasindi, Emrullah
Objectives: To evaluate the perilimbal vasculature of patients who wear contact lenses (CLs) overnight with optical coherence tomography angiography (OCTA) and compare the results with healthy population. Methods: Forty-two patients were included in this observational study. The OCTA imaging was performed in the temporal quadrant of the perilimbal region using a swept-source optical coherence tomography system (Triton DRI-OCT; Topcon Corporation, Tokyo, Japan). The assessments were made in two depths: starting from the conjunctival epithelium to 200 mu m scleral depth and the scleral depth between 200 and 1,000 mu m. The vessel density, vessel length density, vessel diameter index, and fractal dimension were the main outcomes and compared between overnight CL users and healthy population. Results: Twenty-two patients who have been using CLs overnight for at least 3 months and 20 healthy individuals were included in the study. The vessel density at the superficial layer was significantly higher in the CL group compared with the control group (P<0.001). Vessel diameter index, vessel length density, and fractal dimension at the superficial layer did not differ between the groups (P>0.05 for all). There was no difference in the vessel density, vessel diameter index, vessel length density, and fractal dimension in the deep layer between the groups (P>0.05 for all). Conclusions: Patients who use CL overnight exhibit increased vessel density in the superficial layers of the perilimbal region, which may suggest new vessel formation in the conjunctiva. Anterior segment OCTA may be useful to evaluate the initial changes in limbal vasculature in CL users.

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