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Investigation of the effects of shallow and deep cryogenic treatment on the mechanical and microstructural properties of AISI 431 martensitic stainless steel
Get PDFThis study aimed to determine the effects of cryogenic treatment to increase the hardness, wear resistance, and tensile strength of AISI 431 martensitic stainless steel. After austenitizing, quenching, and tempering, the steel samples were subjected to shallow cryogenic treatment at -80 degrees C and deep cryogenic treatment at -180 degrees C. Samples were cryopreserved for 12 and 24 h in each case. Following these processes, a tempering heat treatment was applied at 200 degrees C for 120 min. Experimental results revealed that cryogenic treatment positively affected the mechanical properties of AISI 431 steel. Samples that underwent a 24-h deep cryogenic treatment, however, yielded the best mechanical characteristics. Wear resistance was most significantly affected by cryogenic treatment. Compared to the sample with only conventional hardening, the wear rate of the sample with deep cryogenic treatment for 24 h was 82% lower. Between shallow and deep cryogenic treatment types, samples treated with deep cryogenic treatment exhibited superior properties. In both species, longer cryogenic treatment holding time resulted in greater improvement in mechanical properties. Deep cryogenic treatment for 24 h provided approximately 5.61%, 7.49% and 1.75% increase in hardness, yield strength and tensile strength, respectively. In addition, cryogenic treatment has been shown to effectively reduce residual austenite, providing more homogeneous carbide distribution and new carbide precipitation.Duezce Universitesi [BAP-2020.22.01.1114]The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Duezce Universitesi, (grant number BAP-2020.22.01.1114)
Examination of the stress level of parents with children aged 0-4 and the affecting factors
Get PDF0-4 yaş arası çocuğa sahip ebeveynlerin stres düzeyleri, çeşitli karmaşık faktörlerden etkilenmektedir. Bu dönem, ebeveynlerin çocuklarının gelişimini desteklemek amacıyla üstlendikleri yeni sorumluluklar nedeniyle doğal olarak stres seviyelerinde artışa yol açmaktadır. Aile dinamikleri ve geniş sosyal çevre de ruh sağlığı üzerinde önemli etkilere sahiptir; destekleyici bir aile yapısı ve arkadaş çevresi, stresi azaltmada faydalı olabilir. Bunun yanı sıra, çocukların sağlık sorunları veya davranışsal zorlukları, ebeveynlerde yoğun bir stres hissettirerek endişelerini artırabilir. Tüm bu unsurlar göz önüne alındığında, ebeveynlerin zihinsel sağlıklarını korumak ve stresle başa çıkmalarını kolaylaştırmak amacıyla destekleyici mekanizmaların geliştirilmesi son derece önemlidir. Bu çalışma 4 yaş altı çocuğu olan ebeveynlerin stres düzeyinin ve etkileyen faktörlerin incelenmesi amacı ile tanımlayıcı ve kesitsel türde yapılmıştır. Araştırma, Mayıs 2024- Kasım 2024 tarihleri arasında çevirim içi bir form üzerinden gerçekleştirilmiştir. Araştırma toplum tabanlı olarak 4 yaş altı çocuğu olan 260 ebeveyni kapsamıştır. Verilerin toplanmasında; literatür bilgileri doğrultusunda hazırlanan, aile ve çocuk ile ilgili tanıtıcı özellikleri içeren "Kişisel Bilgi Formu", "Ebeveyn Stres Ölçeği" kullanılmıştır. Bu çalışma, 4 yaş altı çocuğu olan ebeveynlerde stres düzeyinin sosyo-demografik ve sağlık durumu değişkenleriyle anlamlı farklılıklar gösterdiğini, çocuğun sağlık durumu ve aile içi iletişim algısının da ebeveyn stres düzeyleri üzerinde etkisi olduğunu ortaya koymaktadır. Bu doğrultuda stres düzeyi yüksek ebeveynlere yönelik programlar ebeveynin uyumunun ve konforunun artmasına, ebeveynin daha az stresli olmasına etki ederek çocuk bakımın kalitesinin artıracaktır.This research shows that the stress levels of parents with children between the ages of 0-4 are affected by various complex factors. This period naturally leads to an increase in stress levels due to the new responsibilities that parents take on in order to support the development of their children. Family dynamics and the wider social environment also have important effects on mental health; a supportive family structure and a circle of friends can be useful in reducing stress. In addition, children's health problems or behavioral difficulties can increase their anxiety by making parents feel intense stress. Given all these elements, it is extremely important to develop supportive mechanisms in order to protect parents' mental health and make it easier for them to cope with stress. This descriptive and cross-sectional study was conducted to examine the stress level of parents with children under 4 years of age and the factors affecting them. The study was conducted between May 2024 and November 2024 using an online form. The study included 260 community-based parents with children under 4 years of age. In the collection of data; 'Personal Information Form' and 'Parental Stress Scale', which were prepared in line with the literature information, including descriptive characteristics about the family and child, were used. This study reveals that the stress level of parents with children under 4 years of age shows significant differences with socio-demographic and health status variables, and that the health status of the child and the perception of communication within the family also have an effect on parental stress levels. In this direction, programmes for parents with high stress levels will increase the quality of child care by increasing the harmony and comfort of the parents and making the parents less stressed
Developing colleagues through recognition: The role of international award-winning teachers in professional growth in Türkiye
Get PDFThis qualitative study examines how internationally award-winning teachers in Türkiye facilitate colleagues' professional development. Through interviews with 20 teachers, the research investigates mentorship, collaboration, and innovative pedagogical practices in peer development contexts. Findings reveal that award-winning teachers employ student-centered approaches and demonstrate teacher leadership, particularly through platforms like eTwinning. Global recognition enhances professional visibility and strengthens teachers' leadership roles within educational communities. However, tensions emerge from neoliberal education policies and competitive award systems that simultaneously foster collaboration and generate competition among teachers. The study demonstrates that international awards significantly impact professional learning cultures by creating dual dynamics of support and rivalry. These findings contribute to understanding how recognition mechanisms shape teacher development within Türkiye's educational landscape, revealing the complex interplay between global acknowledgment and local pedagogical practices in professional growth. © 2025 Elsevier B.V., All rights reserved
Dynamic serum biomarkers in infantile hemangioma: the role of VEGF-B, AKT, and eNOS in lesion regression
Get PDFInfantile hemangioma (IH) is the most common vascular tumor in infancy. This study aimed to investigate serum levels of VEGF-B, AKT, and eNOS in complicated versus uncomplicated cases of infantile hemangioma and evaluate their correlation with clinical regression scores over time. In this prospective study, we followed 64 patients with intrahospital hemorrhage (IH). Patients were grouped into two categories: complicated (n = 44) and uncomplicated (n = 20). Serum/plasma samples were collected on day 0 from all patients and on days 30 and 60 from complicated cases. ELISA techniques were used to quantify serum VEGF-B, AKT, and eNOS levels. A novel four-domain clinical regression scoring system (size, color, surface, and vascular activity; total 0-12 points) was developed and applied for the first 3 months of follow-up at each visit. VEGF-B, AKT, and eNOS serum levels were significantly higher at baseline in complicated IH and decreased over time with regression. However, AKT serum levels showed a significant decline only in the days of 60 (p = 0.043). Clinical regression scores increased in parallel, with substantial differences between healed and non-healed cases. ROC analysis revealed that day 30 and day 60 clinical scores strongly predicted complete healing (AUC = 0.739 and 0.850, respectively).Conclusion: The VEGF-B/VEGFR-1, AKT/mTOR, and eNOS pathways appear central to IH pathogenesis. Serum levels of these molecules may serve as dynamic biomarkers of disease phase and response to therapy. This study contributes novel data supporting potential targets for future personalized treatment strategies with a novel 3-month follow-up regression score predicting resolution.What is Known:center dot Angiogenic mediators such as VEGF-A, bFGF, Akt, and eNOS are elevated during the proliferative phase of infantile hemangioma and decline with propranolol treatment.center dot Previous studies have primarily investigated tissue-level expression, and there is limited clinical data on serum VEGF-B, Akt, and eNOS levels in IH patients.What is New:center dot This is the first clinical study to longitudinally measure serum VEGF-B, AKT, and eNOS levels in infantile hemangioma patients and track their changes during treatment-induced involution.center dot A novel, four-domain clinical regression scoring system (size, color, surface, vascular activity) was introduced and shown to predict treatment response within the first 60 days of follow-up.Dzce niversitesi [2024.04.03.1453]Duzce University Scientific Research Projects (DUBAP)This study was supported by Duzce University Scientific Research Projects (DUBAP; Project number: 2024.04.03.1453)
A Meta-Analytic Review for Determining the Antecedents and Outcomes of Firm-Level Innovation Capability
Get PDFBu çalışma firma seviyesi inovasyon yeteneğinin öncülleri ve çıktılarını ele alan bilimsel çalışmaların meta analizini uygulamayı amaçlamaktadır. Araştırmada Web of Science, Scopus ve ProQuest veri tabanları taranmış, 56 çalışma analize tabi tutulmuştur. Bu doğrultuda beşeri sermaye, sosyal sermaye, müşteri yönelimi, pazar yönelimi, rakip yönelimi, öğrenme yönelimi, öğrenmeye bağlılık, örgütsel öğrenme, özümseme kapasitesi, örgüt içi bilgi paylaşma, dönüşümcü liderlik ve örgüt içi güven olmak üzere on iki öncül ve firma performansı, finansal performans, iş performansı, inovasyon performansı ve rekabet avantajı olmak üzere beş çıktı tespit edilmiştir. Son olarak çalışmaların yapıldığı ülke ve sektöre göre alt grup analizine dayanan moderatör analizi yapılmıştır.This study conducts a meta-analysis on the antecedents and outcomes of firm-level innovation capability, based on 56 studies from Web of Science, Scopus, and ProQuest databases. Key antecedents include human capital, social capital, customer, competitor, market and learning orientations, commitment to learning, organizational learning, absorptive capacity, intra-organizational knowledge sharing, transformational leadership, and intra-organizational trust. Outcomes identified are firm performance, financial performance, innovation performance, job performance, and competitive advantage. A moderator analysis by country and sector was also performed
The position of technical competence in establishing digital data security awareness
Get PDFThis research aimed to investigate the explanatory and predictive relationships between digital literacy components and digital data security. The study was carried out with 322 students enrolled in the education faculties of eight randomly selected universities. In the research, the attitudes, cognitive and social variables of digital literacy were exogenous. A mediation model has been established in which the technical variable is the mediator, and the digital data security awareness is endogenous. According to the analysis results of the mediation model, the technical variable fully mediates between the attitude, cognitive and social variables, and the awareness of digital data security. These results show that developing digital literacy skills and if these skills are supported with technical knowledge can contribute to developing digital data security awareness. As a result, digital literacy skills will only have the expected effect on creating digital data security awareness with the technical information tool variable. According to our mediation model, the technical competence to be developed with the support of digital literacy skills and the creation of digital data security awareness can guide researchers and instructors working in the field
Enhanced Transepithelial Riboflavin Delivery Across the Cornea Using Magnetic Nanocarriers
Get PDFPurpose: Keratoconus is a progressive corneal ectasia characterized by irregular astigmatism, leading to corneal scarring and decreased vision. Corneal cross-linking (CXL) is the standard treatment to halt disease progression, but its effectiveness in transepithelial (epithelium-on, epi-on) approaches is limited by the low permeability of the corneal epithelium to riboflavin (Rb). This study aimed to enhance transepithelial Rb penetration in ex vivo bovine corneas using Rb-modified tannic acid-coated superparamagnetic iron oxide nanoparticles (Rb-TA-SPIONs) under an external magnetic field.Methods: SPIONs were synthesized via co-precipitation, modified with TA and Rb, and characterized by physicochemical techniques. The average size of the Rb-TA-SPIONs was 46 +/- 5.3 nm, with a saturation magnetization of 55.9 emu/g. Ex vivo experiments involved the application of 0.1% Rb to bovine corneas, and penetration was evaluated under epi-on conditions with iontophoresis (1-5 mA, 5 min). In addition, a 0.1% Rb-containing nanocarrier solution was tested under magnetic fields of 1-300 Gauss.Results: Results showed increased Rb penetration with rising electric current density and Rb-TA-SPION penetration with stronger magnetic fields, compared with epi-on control groups. Specifically, Rb penetration increased from 0.036% (P <= 0.01) at 1 mA to 0.059% (P <= 0.001) at 5 mA in the iontophoresis group and from 0.035% (P <= 0.001) at 1 G to 0.054% (P <= 0.001) at 300 G in the magnetic group.Conclusion: These findings indicate that magnetic nanoparticle-assisted Rb delivery, guided by an external magnetic field, could improve potential CXL efficacy by enhancing Rb penetration and corneal permeability.Yozgat Bozok University Scientific Research Projects Coordination Unit [6602a-TF/19-296]This study was supported by Yozgat Bozok University Scientific Research Projects Coordination Unit (Grant No.6602a-TF/19-296)
Comparison of spinal anesthesia and erector spinae plane block in terms of pain management, perioperative hemodynamic changes, morbidity and mortality in critically adult patients undergoing surgery due to femur fracture
Get PDFGiriş ve Amaç: İleri yaş hastalarda sık görülen kalça kırıkları, tedavisi cerrahi olan, yüksek mortaliteyle seyreden, çoğunlukla postoperatif dönemde yoğun bakımlarda izlenen, sağlık sistemine önemli yük oluşturan bir sağlık sorunudur. Günümüzde rejyonel anestezi teknikleri kalça cerrahilerinde yaygın olarak kullanılmakta olup, spinal anestezi yöntemi uzun süredir güvenle uygulanmaktadır. Güncel çalışmalar ile erektör spina plan bloğu (ESPB) ise etkin rejyonel anestezi ve analjezi yöntemlerinden biri olarak ön plana çıkmıştır. Az sayıdaki hasta serilerinde, temel anestezik yöntem olarak ESPB uygulaması bildirilmiştir. Bu çalışmanın amacı; temel anestezi yöntemi olarak kullanılan spinal anestezi ve ESPB uygulamalarının, kalça kırığı nedeniyle cerrahi geçiren kritik yetişkin hasta grubunda, perioperatif hemodinami, ağrı ve mortalite üzerine etkilerini karşılaştırmaktır. Gereç ve Yöntem: Bu prospektif, randomize ve kör gözlemcili klinik çalışmada, kalça kırığı mevcut, 65 yaş ve üzeri, ASA skoru ≥ III, kırılganlık indeksi ≥ 5 olan toplam 40 hasta dahil edilmiştir. Katılımcılar, iki gruba (Grup 1: ESPB uygulananlar; Grup 2: spinal anestezi uygulananlar) randomize edilmiştir. Preoperatif dönemde demografik veriler, vital bulgular ve ağrı skorları kaydedilmiştir. İntraoperatif ve postoperatif takipte hemodinamik parametreler, sedasyon düzeyleri, komplikasyonlar, ağrı skorları ve analjezik gereksinimleri belirli zaman dilimlerinde sistematik olarak izlenmiştir. Hastalar taburculuk sonrası 30. ve 90. günlerde mortalite açısından değerlendirilmiştir. Elde edilen veriler SPSS 18.0 programında analiz edilmiş; uygun istatistiksel testlerle gruplar arası farklar %95 güven aralığında ve p<0.05 anlamlılık düzeyinde değerlendirilmiştir. Bulgular: Hastaların 20'si ESPB, 20'si ise spinal anestezi altında opere edildi. Demografik veriler açısından gruplar benzerdi. İntraoperatif izlemde, spinal anestezi uygulanan hastaların 0. ve 45. dakikada ölçülen diyastolik kan basınçları ile 45. dakikadaki ortalama kan basıncı ESPB grubuna göre istatistiksel olarak daha düşük bulundu (sırasıyla p=0,007, p=0,026, p<0,05). Spinal anestezi grubunda intraoperatif dönemde hipotansiyon görülme oranı (p=0,025), efedrin ihtiyacı (p=0,018) ESPB grubuna göre anlamlı düzeyde yüksekti. ESPB grubunda ise propofol gereksinimi, spinal anestezi grubuna göre anlamlı düzeyde yüksek olarak gözlendi (p<0,001). Postoperatif yoğun bakım izleminde spinal anestezi uygulanan hastaların 6. saatteki diyastolik ve ortalama, 12. saatteki sistolik ve 18. saatteki diyastolik ve ortalama kan basıncı ölçümleri ESPB grubuna kıyasla anlamlı şekilde daha düşüktü (sırasıyla p=0,032, p=0,032, p=0,028, p=0,027, p=0,020). Postoperatif ilk 30 gün içindeki ve 30-90 gün arasındaki mortalite oranları gruplar arasında benzerdi (sırasıyla p=0,605, p=0,999). Ortalama mortalite günü açısından da istatistiksel anlamlılık gözlenmedi (p=0,174). Sonuç: ESPB, intraoperatif dönemde sedasyon (propofol) ihtiyacını arttırmakta olsa da intraoperatif ve postoperatif süreçte hemodinamik bulgularda stabilite sağlaması, daha az hipotansiyon komplikasyonu göstermesi, postoperatif analjezi ve mortalite üzerinde etkisinin spinal anestezi ile benzer düzeyde olması nedenleriyle, kırılganlık indeksi 5 ve üzerinde olan yaşlı yetişkin hasta grubunda, femur fraktürü cerrahisinde spinal anesteziye iyi bir alternatif olarak tercih edilebilir.Introduction and Aim: Hip fractures are commonly encountered in the elderly population and require surgical treatment. They are associated with high mortality rates and often require postoperative intensive care follow-up, placing a significant burden on the healthcare system. Currently, regional anesthesia techniques are widely used in hip surgeries, with spinal anesthesia being a well-established and reliable method. Recently, erector spinae plane block (ESPB) has emerged as an effective regional anesthesia and analgesia technique. Some case series with fewer patient populations have reported the use of ESPB as the primary anesthetic method. This study aims to compare the effects of spinal anesthesia and ESPB, used as primary anesthesia methods, on perioperative hemodynamics, pain control, and mortality in critically ill adult patients undergoing surgery for hip fractures. Materials and Methods: This prospective, randomized clinical study included 40 patients aged ≥ 65 years with hip fractures, ASA score ≥ III, and frailty index ≥5. Participants were randomly assigned to two groups (Group 1: patients who received ESPB; Group 2: patients who received spinal anesthesia). The demographic data, vital signs, and pain scores were recorded preoperatively. Intraoperative and postoperative hemodynamic parameters, sedation levels, complications, pain scores, and analgesic requirements were recorded at specified intervals. Patients were followed-up for mortality on postoperative days 30 and 90. Data were analyzed using SPSS 18.0, and intergroup differences were evaluated using appropriate statistical tests with a 95% confidence interval and significance level of p<0.05. Results: Of the patients, 20 underwent surgery under ESPB and 20 under spinal anesthesia. The demographic variables were similar between the groups. Intraoperatively, diastolic blood pressure at minutes 0 and 45 and mean arterial pressure at minute 45 were significantly lower in the spinal anesthesia group than in the ESPB group (p=0.007, p=0.026, and p<0.05, respectively). The incidence of intraoperative hypotension (p=0.025) and ephedrine requirement (p=0.018) were significantly higher in the spinal anesthesia group, while the requirement for propofol was significantly higher in the ESPB group (p<0.001). In the postoperative intensive care follow-up, the spinal anesthesia group exhibited significantly lower diastolic and mean blood pressure at 6 h, systolic blood pressure at 12 h, and diastolic and mean blood pressure at 18 h than the ESPB group (p=0.032, p=0.032, p=0.028, p=0.027, p=0.020, respectively). The mortality rates within the first 30 days postoperatively and between days 30 and 90 were similar between the groups (p=0.605 and p=0.999, respectively), with no significant difference in the mean day of mortality (p=0.174). Conclusion: Although ESPB was associated with a higher need for sedation (propofol) during the intraoperative period, it provided better hemodynamic stability, demonstrated fewer hypotension-related complications, and showed similar outcomes in terms of postoperative analgesia and mortality compared with spinal anesthesia. Therefore, ESPB can be considered a viable alternative to spinal anesthesia in elderly adult patients with a frailty index of ≥5 undergoing femur fracture surgery
Exploring Moral Distress, Related Factors and Coping in Emergency Nurses: A Mixed Method Study
Get PDFAimTo determine emergency nurses with moral distress level, related factors and coping.DesignThis is a mixed-methods study which included quantitative and qualitative approaches.MethodsIn quantitative phase, surveys were completed to 252 emergency nurses, while in the qualitative phase, semi-structured interviews were conducted with 23 nurses. Descriptive analysis was used for quantitative data and thematic analysis for qualitative data.ResultsThe related factors of moral distress in nurses were as follows; educational status, work experience, satisfaction, and employment status. EN usually uses positive reinterpretation and development to cope with problems and tried to solve moral distress by getting own individual solutions and getting support from colleagues, friends and families due to lack of support from managers. In order to improve healthy working environment and conditions, it is important to create plans and strategies for EDs. It is recommended to develop practical and structural strategies and interventions that effective coping with moral distress by hospital managers.Patient or Public ContributionIt will increase the quality of care provided by nurses and patient satisfaction.Ondokuz Mayis niversitesiWe thank the emergency nurses who participated in this study
Okul Yöneticilerinin Görüşlerine Göre Taşımalı Eğitimde Yaşanan Sorunlar ve Yansımaları
Get PDFAmaç: Bu çalışma, taşımalı eğitimde yaşanan sorunları, yansımalarını ve buna yönelik çözüm önerilerini okul yöneticilerinin görüşleri doğrultusunda ortaya çıkarmayı amaçlamaktadır. Yöntem: Araştırmanın çalışma grubunu, 2021-2022 eğitim öğretim yılında Düzce ilinin Akçakoca ilçesinde bulunan taşımalı eğitim kapsamındaki 12 okul yöneticisi oluşturmaktadır. Çalışma grubunun seçimi için amaçlı örnekleme yöntemlerinden maksimum çeşitlilik örnekleme yöntemi tercih edilmiştir. Veriler, araştırmacı tarafından geliştirilen yarı yapılandırılmış görüşme formu aracılığı ile toplanmıştır. Toplanan veriler içerik analizi yöntemiyle analiz edilmiş, bulgular üç temada betimlenmiştir. Bulgular: Taşımalı eğitimde yaşanan sorunlar; öğrencilerin yaşadığı sorunlar, öğretmenlerin yaşadığı sorunlar, okul yönetiminin yaşadığı sorunlar, velilerle ilgili yaşanan sorunlar, servis şoförleri ve servis araçları ile ilgili yaşanan sorunlar ve üst yönetimle ilgili yaşanan sorunlar olmak üzere altı alt temada toplanmıştır. Taşımalı eğitimde yaşanan sorunların yansımaları; öğrencilere yansımaları, öğretmenlere yansımaları, okul yöneticilerine yansımaları ve velilere yansımaları olmak üzere dört alt temada toplanmıştır. Taşımalı eğitim sorunlarına ve yansımalarına yönelik çözüm önerileri; bakanlık eliyle uygulanabilecek çözümler, milli eğitim müdürlüklerince uygulanabilecek çözümler, okul yönetimince uygulanabilecek çözümler ve öğretmenlerce uygulanabilecek çözümler olmak üzere dört alt temada toplanmıştır. Sonuç: Taşımalı eğitim uygulaması temel eğitimin yaygınlaştırılması, eğitimde fırsat eşitliğinin sağlanması gibi önemli kazanımlar sunsa da araştırma sonuçları taşımalı öğrencilerin süreçte birçok sorun yaşadığını göstermektedir. Eğitimde fırsat eşitliğinin sağlaması için belirtilen sorun alanlarına çözümler geliştirilmesi eğitim sürecinin daha verimli yürümesini sağlayacaktır. Özgünlük: Nitel çalışmalar, doğası gereği her biri özgün sonuçlar içerir. Bu çalışmada, alanyazındaki çalışmalardan farklı olarak lise kademeleri de çalışma grubu olarak seçilmiştir