Atılım Academic Archive (Atılım University)
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Importance of Alkaline Phosphatase as a Predictor of Transient Hypoparathyroidism After Parathyroidectomy
No full textBackgroundThere are insufficient studies that have investigated the relationship between temporary hypoparathyroidism (hypoPTH) and the preoperative serum alkaline phosphatase (ALP) level in patients with no renal function disorder who have undergone isolated parathyroidectomy. The aim of this study was to determine whether or not the preoperative serum ALP level could be a marker which could predict the development of postoperative temporary hypoPTH. MethodsThis cross-sectional study included 158 patients aged > 18 years who were diagnosed with primary hyperparathyroidism (PHPT) between 2017 and 2022. The demographic data of the patients were retrieved from the hospital records. The patients were separated into two groups according to the serum calcium level after the parathyroidectomy, as the normal group and the temporary hypoPTH group. The determinants of temporary hypoPTH developing after parathyroidectomy in PHPT patients were investigated using multivariate logistic regression analysis. ResultsTemporary hypoPTH was determined in 25.3% of patients. The mean age and 25-O-HD level were determined to be lower in the patients who developed temporary hypoPTH compared to those who did not. The preoperative serum ALP, parathormone, and 24-h urine calcium levels were determined to be higher in the cases that developed temporary hypoPTH. As a result of the regression analysis, only the serum ALP level was determined to be an independent risk factor predicting the development of temporary hypoPTH (p: 0.005, OR: 1.021). In the ROC analysis, when a cutoff value of 119.5 pg/mL was taken for ALP, it was determined to have 73% sensitivity and 72% specificity for the prediction of the development of temporary hypoPTH. ConclusionsThe most appropriate treatment for symptomatic PHPT patients selected with positive imaging is minimally invasive parathyroidectomy. The most important postoperative complications are hypocalcemia and hypoPTH. The preoperative serum ALP level may be helpful in determining patients at risk of developing temporary hypoPTH following parathyroidectomy.Atilim UniversityThe authors would like to thank all the hospital staff who contributed to the publication of this article.Science Citation Index Expande
Üremik Kardiyomiyopati ile İlişkili Kalp Yetersizliğinde Böbrek Transplantasyonu Sonrası Miyokart İşlevlerinde İyileşme
No full textObjective: Although left ventricular hypertrophy frequently accompanies end-stage renal disease, heart failure (HF) with reduced ejection fraction (EF) is also observed in a subset of patients. In those patients kidney transplantation (KT) is generally avoided due to an increased risk of mortality in addition to the risks associated with HF. This prospective study was designed to follow patients with HF who were being prepared for KT. Methods: Twenty-five patients with HF due to uremic cardiomyopathy (UC) who had suitable donors (Group 1), 22 patients with HF who could not undergo KT due to a lack of kidney donors (Group 3), and 25 KT candidates with normal ventricular function (Group 2) were included in the study. Left ventricular ejection fraction (LVEF), left atrial diameter (LAD), mitral annular systolic velocity (Sm), left ventricular global longitudinal strain (GLS), and left ventricular mass index (LVMI) values were recorded across four sessions, from pre-transplant to six months post-transplantation. Endomyocardial biopsy was performed for detailed examination of the myocardium in patients in Group 1 and Group 3, and cardiac magnetic resonance imaging (MRI) was performed in all three groups before transplantation. Results: In Group 1, LVEF, Sm, and left ventricular global longitudinal strain (LV-GLS) increased significantly, while LAD and LVMI decreased, all reaching normal levels. In contrast, no changes were observed in Group 3 and Group 2 (P < 0.01 for LVEF, P < 0.01 for GLS, P < 0.01 for LAD, and P < 0.01 for LVMI measurements). No differences in cardiac MRI and biopsy findings were observed between Group 1 and Group 3. Conclusion: Since myocardial function improved significantly and normalized in all patients with it has been demonstrated that UC can be reversible when treated with KT.Emerging Sources Citation Inde
Determining the Hydrogen Production Potential of Conmo6se8 Chevrel Phases
No full textIn this study, the ConMo6Se8 (n = 1, 2, 3, and 4) Chevrel phases are investigated by using Density Functional Theory (DFT) to reveal their potential for photocatalytic hydrogen production. The stability conditions of these phases reveal that CoMo6Se8, Co2Mo6Se8, and Co3Mo6Se8 satisfy the thermodynamic and mechanic stability properties, while Co4Mo6Se8 does not satisfy any of these properties. Furthermore, the formation enthalpy of these phases shows that CoMo6Se8, Co2Mo6Se8, and Co3Mo6Se8 can be synthesized experimentally due to having negative formation enthalpy values. Furthermore, the thermal stabilities of the machine-learning (ML) force fields are investigated by ab-initio molecular dynamics (AIMD) calculations. The electronic properties of these phases are also investigated in detail, and it is found that Co3Mo6Se8 has a suitable band gap for photocatalytic water splitting. Concerning the investigation of the valence band and conduction band levels, it is shown that Co3Mo6Se8 has a conduction band minimum level suitable for producing hydrogen. This study is the first attempt to reveal the hydrogen production performance of the ConMo6Se8 (n = 1, 2, 3, and 4) Chevrel phases as far as the literature is concerned, paving the ground for future investigations in this field. © 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.Istanbul Teknik Üniversitesi, IT; Gazi Üniversitesi, (FGA-2023-8982); Gazi Üniversitesi; Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAK, (120F305); Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAKScience Citation Index Expande
Patient Safety in Healthcare: A Proposal for Ensuring the Use of Regulation-Compliant Safety Devices
No full textBayrak, Tuncay/0000-0001-6826-4350;Medical devices used in health care should fulfill the requirements of the technical regulations to protect patient health. Difficulties in enforcing stricter rules in the new medical device regulations may negatively affect the continuity of care. This study examines the status of manufacturers' compliance with medical device regulations, based on predefined criteria, and proposes a collaborative action plan and an approach to verify regulatory compliance. We conducted a nationwide survey comprising questions grouped by criteria to understand the status of the manufacturers in terms of compliance with the Medical Device Regulation. Four hundred sixty-seven manufacturers participated in the survey. We achieved a Cronbach's alpha of 0.77, which indicates that the survey is statistically reliable. We applied the independent samples t-test to the responses to determine significant features per question and employed factor analysis to investigate the relationships of the questions. The results of independent samples t-tests showed statistically significant differences across groups in replies to several survey items (p < 0.05), indicating that participants' opinions varied based on their demographic characteristics. We applied Exploratory Factor Analysis to introduce the relationships between the questions. The analysis revealed that manufacturers continue to face substantial challenges in acquiring sufficient knowledge and operational capability to meet MDR requirements. In light of these findings, we focused on the person responsible for regulatory compliance, who plays a central role in maintaining regulatory compliance within manufacturing organizations. We proposed an action plan at the macro level to introduce more effective action plans in cooperation with other stakeholders, including healthcare providers, and a verification approach for regulatory compliance to enhance the Person Responsible for Regulatory Compliance's competence. Manufacturers should implement effective postmarketing clinical follow-up plans involving device-oriented parameters for monitoring in the healthcare system, especially in collaboration with health professionals
Influence of the Heat Treatment on the Microstructure, Mechanical and High-Temperature Oxidation Behavior of Hastelloy X Alloy Fabricated Via Laser Powder Bed Fusion
No full textThe effect of building direction and heat treatment on the microstructure, mechanical properties, and high- temperature oxidation behavior of Hastelloy X (HX) alloy fabricated by the laser powder bed fusion (L-PBF) method was studied. Electron backscatter diffraction analyses revealed that the development of textured columnar grains with varying average grain sizes, boundary fractions, and dislocation densities induced the mechanical anisotropy observed in both horizontally and vertically fabricated samples. The yield strength (YS) values of the horizontally and vertically as-fabricated samples were determined as 605.7 +/- 15.9 MPa and 552.3 +/- 8.5 MPa, respectively. The post-processing heat treatment increased the ductility remarkably and reduced YS value down to similar to 445 MPa for all samples by the elimination of microstructural anisotropy and increased grain size subsequent to recrystallization. Oxidation tests conducted at 900 degrees C up to 100 h on as- fabricated samples exhibited severe intergranular oxidation, which was accompanied by the formation of large voids and microcracks as well as spallation of the oxide layer. In contrast, the heat-treatment improved the oxidation resistance of the alloy possibly due to the formation of uniform and dense Cr2O3 layer on the substrate surface.Science Citation Index Expande
On Quasi-Weibull Distribution
No full textExponential distribution together with a variety of its transformations is permanently used both in probability theory and related fields. The most popular one is the power transformation yielding the Weibull distribution. In this paper, the power distribution of exponential random variable is supplemented by a logarithmic factor leading to a new distribution called quasi-Weibull. This is a three-parameter distribution, where one parameter is inherited from the underlying exponential distribution, and the others originate from the transformation. The properties of the quasi-Weibull distribution are studied. Specifically, the impact of the parameters on the analyticity of characteristic function, the existence of the moment generating function, the moment-determinacy/indeterminacy and the behaviour of the hazard function are investigated.Science Citation Index Expande
Microstructure-Based Prediction of Mechanical Properties of Austempered Ductile Iron Using Multiple Linear Regression Analysis
No full textMultiple linear regression analysis (MLRA) was used to predict the mechanical properties of austempered ductile iron (ADI) including yield and tensile strength, uniform elongation, hardening exponent, as well as fracture energy by building a model that uses characteristic features of microstructural constituents as input parameters. The complex multi-scale microstructure of ADI, which is composed of spherical graphite particles over 10 mu m diameter; and an ausferritic matrix with sub-micron sized features, makes it ideal for prediction of mechanical properties. For that purpose, low alloyed ductile iron samples austempered between 300 and 400 degrees C for 45-180 min were tensile tested, and also multi-scale microstructural characterization were carried out using optical microscope, SEM, and EBSD technique. Moreover, a sensitivity analysis was performed to determine which microstructural parameter(s) each mechanical property is most sensitive to. The results show that tensile and yield strength are most sensitive to size and morphology of matrix phases. Moreover, the size and aspect ratio of acicular ferrite correlate well with those of high-carbon austenite; since both form during transformation of parent austenite into ausferrite during austempering treatment. Equiaxed parent austenite grains transform into ausferrite with acicular morphology during the austempering treatment; and presence of equiaxed austenite grains in the austempered samples indicates untransformed regions during austempering treatment. Ductility was found to be more sensitive to nodularity of graphite particles, and this sensitivity was attributed to the size difference between graphite particles and grain size of matrix phases
Feasibility Study of Chatter Suppression in Milling Through Internal Channels
No full textMilling chatter significantly affects machining productivity, and methods to eliminate chatter caused by milling cutter dynamics are limited due to space constraints and the rotation of the milling cutter. This study investigates the impact of fluid-induced damping effect on chatter stability in milling operations and proposes it as an easy to implement and effective method to improve chatter stability caused by a cutter's vibration mode. The approach utilises a viscous fluid, silicone oil, filled into internal coolant channel of the cutting tool to improve stability by increasing the damping. Both modal and milling tests were conducted for the tool with and without silicone oil. The results show that stability can be significantly increased by this method presenting it as a viable chatter suppression technique. The results show a significant improvement in stability by presenting the method as a practical and cost-effective chatter suppression solution. Its ease of implementation makes it attractive for industrial use.Hacettepe University Scientific Research Projects Coordination Unit [FKB-2024-21288]The authors thank MAL Manufacturing Automation Laboratories for providing CutPro's license. HD acknowledges support provided by Hacettepe University Scientific Research Projects Coordination Unit (FKB-2024-21288)
Savaş Tutsaklarının Kamuoyunda Dijital Gösterime Sunulmasından Doğan İnsancıl Hukuk Sorunları
No full textSosyal medya çağında savaş tutsaklarının dijital olarak gösterime sokulma uygulaması önemli bir tartışma konusu oluşturmaktadır. Savaş tutsaklarının dijital yayınlarla kişiselleştirilmeleri onların bedensel zarara uğramalarına yol açabileceği gibi onurlarına da zarar verme potansiyeline sahiptir. Bu durum savaş tutsaklarının sübjektif hakları ile enformasyona dayanan modern savaş yöntemlerinin örtüşmediğini göstermektedir. Savaş tutsaklarının tehlikeye maruz bırakılmasının ve onurlarının kırılmasının toplumun bilgilendirilmesi gerekçesi ile savunulması mümkün değildir. Savaş tutsaklarının teşhiri İnsancıl Hukukun ihlâli dışında insanlık dışı muamele olarak savaş suçu teşkil etmekte ve Uluslararası Ceza Hukuku sorumluluğuna da yol açabilmektedir. Uluslararası Ceza Mahkemesi Statüsü bedensel zarar vermemekle beraber nefret uyandıran sosyal değersizleştirmeye ve kişilik haklarını yok etmeye yol açan eylemlerin insanlık dışı muamele teşkil ettiğini, dolayısı ile savaş suçu oluşturabileceğini kabul etmektedir. Makale dijital yayınların İnsancıl Hukukta yol açtığı sorunlara ve bu bağlamda önerilen çözümlere ışık tutmaktadır
Physical and Mental Effects of Different Radical Prostatectomy Techniques on Urologic Surgeons
No full textObjective In this web-based international survey study, we aimed to show an association between physical exhaustion and patient, relatives, and employer-related mental stress for surgeons performing open radical prostatectomy (ORP), laparoscopic radical prostatectomy (LRP), and robot-assisted laparoscopic prostatectomy (RALP). Additionally, we also aimed to compare the outcomes of three approaches. Methods We sent a ten-question survey to the urologists performing ORP, LRP, and RALP via e-mail and social media. Only fully completed surveys were included in the study analysis. We asked questions about age, the preferred surgical approach for radical prostatectomy, frequency of weekly exercise, and their possible associations with physical exhaustion and musculoskeletal complaints. Results A total of 160 urologists completed the survey. The RALP group showed a lower physical exhaustion rate and increased eye strain (p 0.05). Conclusion Compared to ORP and LRP, physical exhaustion was lower in the RALP technique. Although the number of participants was limited, regular exercise weakly improved physical exhaustion and musculoskeletal complaints. We believe that regular sports activities by urologists dealing with LRP and RALP will help relieve physical discomfort.Turkish Association of Urology, Turkish Endourology SocietyAs authors, we would like to thank the Turkish Association of Urology, Turkish Endourology Society, and Turkurolap Education and Research Group for their support in reaching out to members of urologists