AXSIS (Yeditepe Üniversitesi)
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Approximation of the Role of Mineralized Collagen Fibril Orientation in the Mechanical Properties of Bone: A Computational Study on Dehydrated Osteonal Lamellar Bone
No full textBone is a natural composite of the hierarchical arrangement of mineralized collagen fibrils in various orientations. This study aims to understand how the orientation of the bone mineral, guiding the removal of water contained in the humidity-responsive layers during dehydration, affects its mechanical properties. A sublamellar pattern with mineralized collagen fibrils oriented between 0° to 150° at 5° angles was the model studied. Using basic transformational computational methods, dimensional change was calculated in the transverse and oblique planes of osteonal lamellar bone while considering bone components sensitive to dehydration in radial, tangential, and axial orientations. The anisotropy ratios of the change in the dimension of the variable mineralized collagen fibril orientations calculated using the computed model displayed values ranging between 0.847 to 2.092 for the transverse plane and 0.9856 to 1.0207 for the oblique plane. A comparison of the anisotropy results of the suggested model indicated that they approach the experimental results of both transversely and obliquely cut samples. As collagen fibril and mineral orientation take place both temporally and spatially in relationship with the static and dynamic loads placed on the different volumes of bone, the results may imply that the mechanical demands involved in bone resorption and deposition contribute to the formation of this multi-faceted and hierarchically structured natural composite. © 2024 by the authors.The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
On the local existence and blow-up solutions to a quasi-linear bi-hyperbolic equation with dynamic boundary conditions
No full textThis note aims to study the existence of the local solutions and derive a blow-up result for a quasi-linear bi-hyperbolic equation with dynamic boundary conditions. We use the maximal monotone operator theory to demonstrate the solution's local well-posedness, and a concavity method to establish the blow-up result. © 2024 The AuthorsThe Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
A New Educational Model Proposal: Competency-Based Modular Disaster Nursing Education
No full textDisasters are extremely serious incidents that have a biopsychosocial effect on the individual, family, and society, and the rate of them is increasing around the world and in our country. The aim of nurses, who represent the majority of health-care workers, is to maintain qualified nursing care by actively participating in every step before, during, and after the disaster. The fundamental needs for providing this quality care are defining nurses' duties and responsibilities in the disaster processes and providing a competency-based disaster nursing education to equip nurses with the necessary disaster knowledge and skills. For this reason, it is necessary to take action to reveal the duties and responsibilities of nurses who will take part in disasters and to undergo a specialized training in the field of disaster nursing. With a training program given at the undergraduate level and in which every nurse will graduate as a potential disaster nurse, nurses can effectively provide the care and service that society needs in all of the disaster prevention, preparation, response, and post-disaster rehabilitation processes. Although there is no standardized application of disaster nursing at the undergraduate level in our country, the number of competency-based models that will guide disaster nursing education is fairly limited in the literature. For this reason, this article was written to define the roles and responsibilities of nurses in the disaster process and to develop an education model based on competencies for providing disaster nursing education at the undergraduate level in our country. © 2024, Ankara University. All rights reserved.Yeditepe Üniversitesi Açık Erişim Sistemi, indekslenmiş yayınların bir derlemesidir. Telif ve kullanım hakları yayıncılara ve/veya yazarlara ait olabilir. Koleksiyon, Yeditepe Üniversitesi akademisyenleri tarafından hazırlanan ve kurumsal arşivde bulunabilecek bilimsel yayınlar için oluşturulmuştur
Decontamination of ochratoxin A from raisins by different processes: evaluation of efficiency and quality attributes
No full textIn this research, the effects of washing treatments (potassium carbonate (PC), potassium hydroxide (PH), peracetic acid (PA), alkaline hydrogen peroxide (AHP)), ultrasound (US) and high-intensity pulsed light (HIPL) technologies on the removal of ochratoxin A (OTA) residues in raisins were investigated. PC at 5 min (66.60), PH at 10 min (65.25), alkaline hydrogen peroxide at 5 min (63.30) and HIPL at 12 J cm−2 (62.50) were found to be the most successful applications in OTA degradation, respectively. Although the OTA degradation rate was high after chemical washing for 10 min, the raisins had a chemical odour. The results show that HIPL effectively reduces OTA levels in raisins without causing any quality loss. © 2024 The Author(s). International Journal of Food Science & Technology published by John Wiley & Sons Ltd on behalf of Institute of Food Science & Technology (IFST).The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
Hypoprolactinemia, a neglected endocrine disorder
No full textThis special issue of Reviews in Endocrine and Metabolic Disorders is dedicated to hypoprolactinemia. Prolactin is known for its actions on the mammary gland including development, preparation for postpartum lactation, as well as synthesis and maintenance of milk secretion. However, prolactin has many other physiological effects on reproduction, embryonic and fetal development, homeostasis, neuroprotection, behavior, and immunoregulation. In clinical practice, physiopathology and clinical consequences of increased prolactin secretion are generally well understood, and medical treatment to decrease prolactin levels is available and effective in most cases. Unlike prolactin excess, hypoprolactinemia has been a neglected endocrine disorder and nospecific replacement therapy is commercially available. Prolactin is the only anterior pituitary hormone not addressed by clinical hypopituitarism guidelines. In recent years, human studies have revealed that hypoprolactinemia is associated with metabolic, sexual and neuropsychologic alterations. Therefore, this special issue of Reviews in Endocrine and Metabolic Disorders is aimed to enhance our incomplete understanding of hypoprolactinemia. A total of 17 articles were authored by respected scientists and clinicians from a variety of disciplines including adult and pediatric endocrinology, pathology, gynecology, reproductive medicine, oncology, and neurosurgery. © The Author(s), under exclusive licence to Springer ScienceBusiness Media, LLC, part of Springer Nature 2024.The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
Evaluation of cardiac autonomic dysfunctions in children with type 1 diabetes mellitus
No full textBackground: Cardiovascular autonomic neuropathy (CAN) is a serious complication of diabetes, impacting the autonomic nerves that regulate the heart and blood vessels. Timely recognition and treatment of CAN are crucial in averting the onset of cardiovascular complications. Both clinically apparent autonomic neuropathy and subclinical autonomic neuropathy, particularly CAN pose a significant risk of morbidity and mortality in children with type 1 diabetes mellitus (T1DM). Notably, CAN can progress silently before manifesting clinically. In our study, we assessed patients with poor metabolic control, without symptoms, following the ISPAD 2022 guideline. The objective is is to determine which parameters we can use to diagnose CAN in the subclinicalperiod.The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive.Methods: Our study is a cross-sectional case-control study that includes 30 children diagnosed with T1DM exhibiting poor metabolic control (average HbA1c > 8.5 for at least 1 year) according to the ISPAD 2022 Consensus Guide. These patients, who are under the care of the pediatric diabetes clinic, underwent evaluation through four noninvasive autonomic tests: echocardiography, 24-h Holter ECG for heart rate variability (HRV), cardiopulmonary exercise test, and tilt table test
Safety and efficacy of viltolarsen in ambulatory and nonambulatory males with Duchenne muscular dystrophy
No full textDuchenne muscular dystrophy (DMD) is an X-linked recessive disease characterized by mutations in the dystrophin gene, causing motor and pulmonary function decline. Viltolarsen is indicated for patients with dystrophin gene mutations amenable to exon 53 skipping. Here, we report safety, motor function, and the first pulmonary function results from the open-label, phase II Galactic53 trial of viltolarsen (NCT04956289). Male participants aged ≥ 8years with DMD received 80mg/kg intravenous viltolarsen once weekly for 48weeks. Results from participants receiving viltolarsen were compared with an external control cohort group-matched for multiple variables. All treatment-emergent adverse events were mild or moderate, 4 were considered treatment-related, and no participants discontinued. Participants receiving viltolarsen experienced clinically meaningful benefits in pulmonary function with higher percent predicted forced vital capacity and higher peak cough flow at Week 49 compared with the control cohort for both ambulatory and nonambulatory participants. Viltolarsen also stabilized upper limb motor function over the Treatment Period. These results support viltolarsen as an important part of the treatment armamentarium for both ambulatory as well as nonambulatory patients with DMD. © The Author(s) 2024.The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
Endoplasmic reticulum stress of endometrial mesenchymal stem cells in endometriosis
No full textObjective: The human endometrium has significant regenerative abilities due to stem cells, which are vital in immunomodulation, immune tolerance, steroid hormone response, and inflammation. Endometriosis, an inflammatory gynecological disorder where endometrium-like tissue grows outside uterus, affects millions of women and often causes infertility. Recent research indicates that stem cells contribute to pathology of endometriosis. ER stress is implicated in various diseases, including endometriosis. This study aims to examine ER stress in eMSCs within endometriosis pathogenesis and uncover underlying disease mechanisms. Methods: Samples were collected from healthy subjects and women with endometriosis in both proliferative and secretory phases. eMSCs were isolated and characterized via flow cytometry. ER stress protein levels were assessed using proteomic analysis, with validation through Western Blot and immunofluorescence staining. Gene expression was analyzed by RT-qPCR, and ultrastructural examination of eMSCs was conducted using TEM. ER stress markers in tissue samples were detected in SUSD2 eMSCs through immunofluorescence staining and visualized using a confocal microscope. Statistical analysis was performed using SPSS program. Results: The proteomics analysis uncovered ER stress-related proteins (DDRGK1, RTN3, ERp44, TMED2, TMEM33, TMX3) whose levels were significantly distinct from control group. Western Blot analysis and immunofluorescence staining results at protein level; RT-qPCR results at gene level supported these findings. TEM analysis also showed ultrastructural presence of ER stress in endometriosis groups. Conclusion: Presence of ER stress in eMSCs in pathogenesis of endometriosis has been demonstrated using various methods. Our research has potential to shed light on pathology of endometriosis and offer promising avenues for non-invasive diagnosis and potential treatment. © 2024The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
Exploring the protective potential of NRF2 overexpressed neural extracellular vesicles against cisplatin-induced neurotoxicity via NRF2/ARE pathway
No full textNeurotoxicity is characterized by the accumulation of harmful chemicals such as heavy metals and drugs in neural tissue, resulting in subsequent neuronal death. Among chemicals platinum-based cancer drugs are frequently used due to their antineoplastic effects, but this drug is also known to cause a wide range of toxicities, such as neurotoxicity. The nuclear-factor-erythroid 2-related factor-2 (NRF2) is crucial in combating oxidative stress and maintaining cellular homeostasis. This study thoroughly explores the protective effects of extracellular vesicles derived from NRF2 gene overexpressed neural progenitor cells (NEVs) on cisplatin-induced neurotoxicity. Therefore, extracellular vesicles derived from neural progenitor cells were isolated and characterized. The Cisplatin neurotoxicity dose was 75 µM in mature, post-mitotic neurons. 1.25 µM of tert-butyl hydroquinone that induces NRF2/ARE pathway was used as the positive control. The effects of extracellular vesicles (EVs) were investigated using functional and molecular assays such as PCR and protein-based assays. Here, we observed that NEVs dose-dependently protected post-mitotic neuron cells in response to cisplatin. The study also examined whether the effect was EV-induced by limiting EV biogenesis. The molecular basis of preventive treatment was established. When pre-administered, 1×108 particles/ml of NEVs maintained antioxidant and detoxifying gene and protein expression levels similar to control cell levels. Furthermore, NEVs reduced both cellular and mitochondrial ROS levels and preserved mitochondrial membrane potential. In addition, Catalase and SOD levels were found higher in NEV-treated cells compared to cisplatin control. The findings in NRF2-based protection of cisplatin-induced neurotoxicity may provide further evidence for the relationship between EVs and inhibition of neuronal stress through the NRF2/ARE pathway, increasing the understanding of neuroprotective responses and the development of gene-engineered EV therapy options for peripheral neuropathy or other neurodegenerative diseases. This is the first study in the literature to investigate the neutralizing potency of NRF2 overexpressed neural EVs against cisplatin-induced neurotoxicity. © 2024 Elsevier B.V.The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive
Nutritional Risks of Heavy Metals in the Human Diet—Multi-Elemental Analysis of Energy Drinks
No full textBackground: In recent years, the consumption of energy drinks (EDs) by adolescents and young adults has increased significantly, so concerns have been raised about the potential health risks associated with excessive ED consumption. Most analyses on EDs focus on the caffeine content. Research on the content of minerals (essential and toxic) in energy drinks can be considered scarce. Therefore, there is a need for research stating the actual status of heavy metal content in commercially available energy drinks. Methods: This research presents the determination of the total concentrations of macro-elements and trace elements (TEs), such as Na, K, Mg, Ca, Al, Cr, Co, Cu, Fe, Mn, Ni, B, Zn, V, Sr, Ba, Pb, Cd, and As in nine samples of energy drinks using inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) techniques. Results: The order in the content of macro-minerals in the EDs was as follows: Na > K > Mg > Ca. The results showed that ED 1, ED 3, and ED 7 samples had the highest micro-mineral concentrations. All the samples had a hazard quotient and hazard index < 1, indicating no non-carcinogenic risk from exposure to single or multiple heavy metals in both the adolescent and adult age groups. Some samples exceeded the threshold limit of acceptable cancer risk for As, Ni, and Cr in both adolescents and adults. Conclusions: This assessment showed that in addition to health implications based on the caffeine content of EDs, there might be a carcinogenic risk associated with the toxic element content of these beverages. This research also highlights notable differences in the TE levels among various ED brands, which may have important implications for consumer well-being and health. © 2024 by the authors.The Yeditepe University Open Access System is a compendium of indexed publications. Copyright and usage rights may be held by publishers and/or authors. The collection was established for the scientific publications prepared by Yeditepe University academicians and is to be found in the institutional archive.This research presents the determination of the total concentrations of macro-elements and trace elements (TEs), such as Na, K, Mg, Ca, Al, Cr, Co, Cu, Fe, Mn, Ni, B, Zn, V, Sr, Ba, Pb, Cd, and As in nine samples of energy drinks using inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) technique