İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
Not a member yet
1249 research outputs found
Sort by
İnsan Falx Cerebelli'sinin morfolojik ve morfometrik özellikleri ve muhtemel klinik önemi
No full textDura mater; beyin ve omuriliği saran, onları destekleyen ve koruyan fibröz, opak ve sert bir zardır (Moore vd., 2016: 865) (Standring, 2021: 398). Bulunduğu yere göre adlandırılır: dura mater cranialis (kraniumda bulunan bölümü) ve dura mater spinalis (columna vertebralis’te bulunan bölümü) (Standring, 2021: 398) (FIPAT, 15)
Prevalence of metabolic dysfunction-associated fatty liver disease in kidney transplant recipients: A cross-sectional study using FibroScan
No full textBackground & Aim: Metabolic dysfunction-associated fatty liver disease (MAFLD) is expected to be prevalent among kidney transplant recipients (KTR). In this study, we evaluated the prevalence of MAFLD among KTRs, a data that has not been investigated by any clinical study to date. Matherials and Methods: We included a total of 52 KTRs and 53 age-, sex-, and BMI-matched individuals as control group through a prospective consecutive recruitment. We detected the presence of hepatic steatosis and liver fibrosis using controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) defined by FibroScan. Results: Among the KTRs, 18 (34.6%) had metabolic syndrome. The prevalence of MAFLD among the KTRs and controls was 42.3% and 51.9%, (p=0.375). The CAP and LSM values did not differ significantly between the KTRs and controls (p=0.222 and p=0.119). Among the KTRs, patients with MAFLD had significantly higher age, BMI, waist circumference, LDL, and total cholesterol levels (p<0.001, p=0.011, p=0.033, p=0.022, and p=0.029, respectively). In multivariable analysis, age was the only independent factor for MAFLD among the KTRs (OR: 1.120, CI 95%: 1.039-1.208). Conclusion: MAFLD among KTRs did not show a significantly higher prevalence compared to the normal population. Further clinical studies with larger populations are needed
Size-based adaptive instance pruning for refined segmentation of cell nuclei in histology images
No full textBu bildiride, histoloji görüntülerinde yer alan hücre çekirdek örneklerinin daha başarılı bir biçimde bölütlenebilmesi amacıyla kullanılabilecek ve hücre tiplerine göre uyarlanabilir bir boyut-bazlı örnek budama yaklaşımı sunulmuştur. Gerçekleştirilen çalışmada, kolon histoloji görüntülerinde yer alan farklı hücre çekirdek tipleri öncelikle U-Net medikal görüntü bölütleme yöntemi ile anlamsal olarak bölütlenmiş ve her bir çekirdek tipi için bölüt haritaları oluşturulmuştur. Devamında, bölüt haritaları üzerinde Havza algoritması koşulmuş ve hücre çekirdek örnekleri elde edilmiştir. Son aşamada ise, uyarlanabilir boyut-bazlı örnek budama yaklaşımı ile, her bir çekirdek tipi için kabul edilebilir çekirdek boyutlarının altında kalan ve çekirdek örneği olarak tasnif edilmeyen örnek bölütler elenmiştir. CoNIC 2022 veri seti üzerinde gerçekleştirilen testlerde, uyarlanabilir boyut-bazlı örnek budama yaklaşımının, bu yaklaşımın kullanılmadığı normal bölütleme metodolojisine göre daha üstün başarı sağladığı gözlemlenmiş ve ortalama 0.5090 mPQ değeri ölçülmüştür.In this paper, a size-based instance pruning approach, which can be used for more accurate segmentation of cell nuclei in histology images and can be adapted to cell types, is presented. In the proposed study, different cell nuclei types in colon histology images were initially segmented semantically using the U-Net medical image segmentation method and the output segmentation maps were produced for each nuclei type. Then, the Watershed algorithm was employed on the segmentation maps and cell nuclei instances were obtained. Finally, instance segments that were below the acceptable nuclei sizes for each nuclei type and were not classified as nuclei instances were eliminated with the adaptive size-based instance pruning approach. In the tests performed on the CoNIC 2022 dataset, it was observed that the adaptive size-based instance pruning approach outperformed the normal segmentation methodology without this approach, and an average value of 0.5090 mPQ was measured
Comparison of fiber reinforcing methods of composite resin: Aflexural strength and stereo microscopy study
No full textThis study aimed to compare the effect of fiber reinforcing methods on the flexural strength and failure modes of indirect composite resins. Based on the reinforcement methods, the bar specimens (3 x 3 x 25 mm) were divided into five groups (n = 20). Glass or polyethylene fibers were used for reinforcement of indirect composite resins. Fibers were either light polymerized and mixed with indirect composite resin or mixed with indirect composite resin after resin application and polymerized together. Indirect composite resin without fiber reinforcement was used as control. All five types of specimens were stored in distilled water at 37 & DEG;C for 24 h. Half of the specimens were additionally thermocycled. Then the specimens were tested in a three-point bending test. Failure types were examined and categorized by using stereo microscope. The data were analyzed using two-way ANOVA and Tukey HSD test. Flexural strength was found to be significantly higher for fiber-reinforced indirect resin composites than control. However, the fiber-reinforced groups did not present any significant difference. Analysis revealed aging does not affect the flexure strength of fiber reinforcement of indirect composite resin. The study concluded that the flexure strength of indirect composite resins was improved with fiber reinforcement. Different fiber reinforcement methods demonstrated similar effects on the flexure strength of indirect composite resin. Reinforcement with glass or polyethylene fibers presented the potential to improve the mechanical properties of indirect composite resins. Research Highlights Flexural strength of indirect composite resins are affected by the reinforcement of composites with glass or polyethylene fibers. Aging with thermocycling has no effect on the flexural strength of the indirect composite resins, however can cause catastrophic failures in material.Bulent Ecevit University--2013-33822697-0
Orthodontics in the era of social media: An interview with orthodontic journal editors
No full textThe current paper presents a series of interviews conducted with editors of prominent orthodontic journals, with a specific focus on the influence of social media on orthodontics as a profession. The interviews revolve around the impact of social media on various aspects, including orthodontic patients, clinicians, education, academia and research. The aim is to explore the effective utilization of social media as a means to advance the profession and discuss its potentials and pitfalls
Determination of cobalt in chamomile tea samples at trace levels by flame atomic absorption spectrophotometry after poly(vinyl alcohol)-magnetic hydrogel based dispersive solid phase extraction
No full textIn this study, an analytical strategy was proposed for the determination of cobalt at trace levels by using a flame atomic absorption spectrophotometry (FAAS) system after magnetic hydrogel based dispersive solid phase extraction (MH-DSPE). Poly(vinyl alcohol) based magnetic hydrogels (PVA-MH) were synthesized easily, quickly, and cost effectively in the laboratory and used as an adsorbent material in the microextraction process. Under the optimum experimental conditions, the limit of detection (LOD) and limit of quantitation (LOQ) values were recorded as 4.2 and 14.1 mg L−1 , respectively. To investigate the matrix effects on the analyte signal, spike experiments were performed using chamomile tea extracts and good recovery results were obtained between 85.7 and 113.8%. A 57.8-fold improvement was achieved in the detection power compared to that of a conventional FAAS system. The results obtained throughout all experimental studies demonstrated the applicability in addition to the accuracy of the method for the quantification of trace levels of cobalt with high accuracy in a chamomile tea matrix
Preparation and characterization studies of dorzolamide loaded ophthalmic implants for the treatment of glaucoma
No full textObjectives: This study aimed to construct dorzolamide loaded ophthalmic implants for extended drug delivery and increased drug retention. Materials and Methods: Carboxymethyl cellulose and Chitosan were used to formulate the ophthalmic implants. The implants were prepared by solvent casting technique in existence of polyethylene glycol 6000 as plasticizer. Physiochemical characterization studies including mechanical characteristics (tensile strength, elongation at break, and Young’s modulus), bioadhesion studies, in vitro and ex vivo drug release studies were conducted. Results: Tensile strength of drug loaded ophthalmic implants were 10.70 and 11.68 MPa respectively. Elongation at break of Carboxymethyl cellulose and Chitosan implants were 62.00% and 59.05% respectively. The in vitro release profiles fit into the Higuchi type kinetic model. Ex vivo release study results for both implants were correlated with in vitro release investigations. Conclusion: Carboxymethyl cellulose and Chitosan based implants provide extended drug delivery. Implants were prepared by using carboxymethyl cellulose provide significantly slower in vitro release rate, and the drug retention on ocular surfaces has been increased. Thus, it has been concluded that, dorzolamide loaded carboxymethyl cellulose implants could provide effective treatment for glaucom
Assessment of the ovarian reserve in patients with Beta-thalassemia major; A prospective longitudinal study
No full textObjective: Repeated blood transfusions in women with Beta-thalassemia major (BTM) may lead to iron overload and increase oxidative stress and consequently resulting in ovarian damage. We aimed to evaluate the alterations in the ovarian reserve of transfusion-dependent BTM patients over a time period of one year and compared the anti-mullerian hormone (AMH) levels between women with BTM and healthy population. Material and methods: This longitudinal prospective study was conducted in 41 women with transfusion-dependent BTM at the tertiary hospital. The hospital database between 1996 to 2021 was screened for women diagnosed with BTM. Anti-mullerian hormone levels were assessed at baseline and one year later. Results: Twenty-five (60.9%) of the patients had amenorrhea while 16 (39.1%) were observed to have normal cycles. The mean AMH values of all women were 2.7±1.8 ng/mL at the initial measurement which was significantly lower compared to age related AMH (mean 4.0±0.4 ng/mL) nomogram of healthy population (P= 0.001). The baseline AMH values of the patients with amenorrhea were found to be lower than the patients with normal menstrual cycles (2.1±1.8 vs 3.6±1.5 ng/mL, P= 0.009). After a one-year follow-up, there was a trend towards to a decrease in AMH levels of the patients with normal menstrual cycles. Conclusion: Serum AMH values is decreased in patients with transfusion-dependent BTM. It would be beneficial to inform all patients about possible effects of repeated blood transfusions on fertility
Antibacterial mechanism with consequent cytotoxicity of different reinforcements in biodegradable magnesium and zinc alloys: A review
No full textUniversiti Teknologi PETRONAS (UTP) -- 015LC0-336Benefits achieved by the biodegradable magnesium (Mg) and zinc (Zn) implants could be suppressed due to the invasion of infectious microbial, common bacteria, and fungi. Postoperative medications and the antibacterial properties of pure Mg and Zn are insufficient against biofilm and antibiotic-resistant bacteria, bringing osteomyelitis, necrosis, and even death. This study evaluates the antibacterial performance of biodegradable Mg and Zn alloys of different reinforcements, including silver (Ag), copper (Cu), lithium (Li), and gallium (Ga). Copper ions (Cu2+) can eradicate biofilms and antibiotic-resistant bacteria by extracting electrons from the cellular structure. Silver ion (Ag+) kills bacteria by creating bonds with the thiol group. Gallium ion (Ga3+) inhibits ferric ion (Fe3+) absorption, leading to nutrient deficiency and bacterial death. Nanoparticles and reactive oxygen species (ROS) can penetrate bacteria cell walls directly, develop bonds with receptors, and damage nucleotides. Antibacterial action depends on the alkali nature of metal ions and their degradation rate, which often causes cytotoxicity in living cells. Therefore, this review emphasizes the insight into degradation rate, antibacterial mechanism, and their consequent cytotoxicity and observes the correlation between antibacterial performance and oxidation number of metal ions
Savaşın yıktığı bölgede işbirliği ve kar amacı gütmeyen kuruluş performansı: Dış bilginin ve yenilikçi iklimin rolü
No full textThe inconsistent findings on the association between non-profit coopetition and performance are complicated and contingent on essential factors. However, our current understanding of the circumstances under which non-profit coopetition matters to performance is limited. We take a novel context to address this question and build on the combined literature from the emerging non-profit coopetition literature. This study conceptualises and tests the impact of coopetition (simultaneous cooperation and competition) on the organisational performance of non-profit organisations in a war-torn region. Notably, it investigates the simultaneous cooperation and competition in non-profits’ social and financial performance via outside knowledge and innovative climate. An in-person survey with 158 executives and board members was conducted in Baghdad Governorate, Iraq. The survey adopted reliable and valid scales to measure the variables. Structural equation modelling was applied to test the mediation model. The proposed sequential mediating model has a good model fit with all four hypotheses statistically significant. Nonprofit engagement in coopetition positively affects organisation performance via mediators: use of outside knowledge and innovative climate. Cooperation with competitors helps non-profits to effectively use the outside knowledge that forms an innovative climate at the organisational level. Additionally, the use of outside knowledge has a direct effect on performance. Non-profits should integrate outside and internal knowledge to generate sustainable financial and social performance opportunities, especially in turbulent or war-torn regions. Moreover, context is imperative for non-profit leaders to identify themselves and seek inter-organisational relationships. The study also provides theoretical and practical implications that help non-profit leaders innovate and increase organisational performance.Kâr amacı gütmeyen kuruluşların iş birliği ile performans arasındaki ilişkiye dair tutarsız bulgular karmaşıktır ve temel faktörlere bağlıdır. Ancak, kâr amacı gütmeyen kuruluşların iş birliğinin performans açısından hangi koşullar altında önemli olduğuna dair mevcut anlayışımız sınırlıdır. Bu soruyu ele almak için yeni bir bağlamı ele alıyor ve gelişmekte olan kâr amacı gütmeyen iş birliği alan yazınından birleşik alan yazına dayanıyoruz. Bu çalışma, iş birliğinin (eşzamanlı iş birliği ve rekabet) savaştan zarar görmüş bir bölgedeki kâr amacı gütmeyen kuruluşların örgütsel performansı üzerindeki etkisini kavramsallaştırmakta ve test etmektedir. Özellikle, kâr amacı gütmeyen kuruluşların sosyal ve finansal performansı üzerindeki eş zamanlı iş birliği ve rekabeti, dışarıdan bilgi ve yenilikçi iklim kullanımı yoluyla araştırmaktadır. Irak’ın Bağdat ilinde 158 yönetici ve yönetim kurulu üyesi ile yüz yüze bir anket gerçekleştirilmiştir. Ankette değişkenleri ölçmek için güvenilir ve geçerli ölçekler kullanılmıştır. Aracılık modelini test etmek için yapısal eşitlik modellemesi uygulanmıştır. Önerilen sıralı aracılık modeli, dört hipotezin tümü istatistiksel olarak anlamlı olacak şekilde iyi bir model uyumuna sahiptir. Kâr amacı gütmeyen kuruluşların birlikte rekabete girmesi, aracılar vasıtasıyla kuruluş performansını olumlu yönde etkilemektedir: dış bilgi kullanımı ve yenilikçi iklim. Rakiplerle iş birliği, kar amacı gütmeyen kuruluşların kurumsal düzeyde yenilikçi bir iklim oluşturan dış bilgiyi etkin bir şekilde kullanmalarına yardımcı olmaktadır. Ayrıca, dış bilginin kullanımı performans üzerinde doğrudan bir etkiye sahiptir. Kâr amacı gütmeyen kuruluşlar, özellikle çalkantılı veya savaştan zarar görmüş bölgelerde sürdürülebilir finansal ve sosyal performans fırsatları yaratmak için dış ve iç bilgiyi entegre etmelidir. Ayrıca, kâr amacı gütmeyen liderlerin kendilerini tanımlamaları ve örgütler arası ilişkiler aramaları için bağlam zorunludur. Çalışma ayrıca kâr amacı gütmeyen liderlerin yenilik yapmalarına ve kurumsal performansı artırmalarına yardımcı olacak teorik ve pratik çıkarımlar da sunmaktadır