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Adrenal hypoandrogenism in adolescents with premature ovarian insufficiency
No full textAbstract Objectives Premature ovarian insufficiency (POI) affects 1 in 10,000 children, with its molecular causes largely unknown. Adult studies suggest that low androgen levels induce ovarian insufficiency, but data on about this in children is limited. This study aims to assess the prevalence of low androgen levels in childhood POI and its relationship with adrenal insufficiency. Methods Idiopathic POI adolescents were categorized into two groups based on DHEAS and total testosterone (TT) measured by chemiluminescence. Low androgen group (LAG) was defined using cut-offs according to Tanner pubarche staging. Demographic, clinical, and laboratory data were compared. Morning cortisol <7 μg/dL and/or ACTH >96 or <5 pg/mL were planned to undergo ACTH stimulation testing, with a peak cortisol response <18 μg/dL considered insufficient. Results Forty-three adolescents, mean age 15.5 ± 1.3 years with a 46, XX karyotype, normal FMR1 mutation, FSH levels >40 mIU/mL, and low AMH levels were included. In 14 cases (37.8 %), DHEAS and TT were low. In the LAG, pubarche was absent in seven patients, and initial height SDS was significantly lower. Morning cortisol ranged from 7.9 to 23.5 μg/dL, with an ACTH of 29.4 ± 9.7 pg/mL. No differences in adrenal steroids or correlations between DHEAS and ACTH were observed. Conclusions Diminished androgen levels are prevalent in children with idiopathic POI. The potential for this condition to increase the risk of adrenal insufficiency and its impact on secondary ovarian insufficiency remains unclear. This study, the first of its kind in children, underscores the potential role of genetic factors in zona reticularis and ovarian development. </jats:sec
Generalised Leonardo numbers
No full textAbstract This note covers some of the history of Leonardo numbers. We retrieve some of the most recent results on this sequence, as well as some relevant historical interconnections. In the end, we also provide some conjectures and open problems for some of its extensions involving the modular periodicity.</jats:p
Effects of Autapse and Channel Blockage on Firing Regularity in a Biological Neuronal Network
No full textOrtaokul Matematik Öğretmenlerinin İlköğretim Matematik Öğretmenliği Lisans Programı Hakkındaki Görüşleri
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THE CHANGING STAGE OF (DIGITAL) SELF-PRESENTATION: INTERNET MEMES AND THE BARBENHEIMER
No full textThe expanding influence of the internet and social media networks increasingly digitizes individual representations. This new structure, where the boundaries between the virtual and non-virtual (real) worlds blur, also eliminates the distinction between producer and consumer in the context of content creation. This digital universe, characterized by the features of a productive network, fosters creativity while enabling a digitized communication environment through accessible, fluid, easily transferable, and adaptable content as a system. One of the most significant elements of this digitalized shared space is internet memes, which generally consist of a combination of textual and visual elements and function through repetition and adaptation. Memes, which are studied within the framework of political-social movements or advertising and marketing in the relevant academic literature, have not been sufficiently addressed in terms of (digital) self-presentation, including users’ cultural preferences, desires, and expectations. Instead, the focus has largely been limited to studies on selfies and representations of the body. The simultaneous release of the films Barbie and Oppenheimer on July 21, 2023, not only broke box office records but also sparked numerous debates, giving rise to a new concept that originated among cinema audiences and gradually influenced broader audiences. The term Barbenheimer, created by combining the names of these two films, became a medium for digital self-presentation, particularly on social media platforms such as Twitter (now X). This new concept and framework, which has persisted since July 2023, constitutes the focus of our study, specifically in the context of the use of internet memes. Our research focuses on the fluid and evolving nature of the relationship between internet memes, visual communication, and digital self-presentation, based on a content analysis of 250 tweets containing the keyword Barbenheimer and drawing on the emerging literature.</jats:p
Structural, quantum chemical, spectroscopic (UV, FT-IR, and NMR), and molecular docking studies of novel azo compounds
No full textA set of novel azo compounds were created, and their structures were identified using spectroscopic methods such as FT-IR, 13C NMR, 1H NMR, and HR-MS. The DFT/TD-DFT approach using the B3LYP/6–311++G(d,p) was employed to calculate the molecular structure and electronic properties of novel azo compounds. Comparative analysis has been conducted between theoretical spectral data and experimental data, revealing a significant degree of concordance. An analysis was performed on the vibrational frequencies (IR), UV–vis absorption wavelengths, and NMR chemical shifts of novel azo compounds. Furthermore, molecular docking analyses were conducted to examine the interactions between the 1M17 and 4ASD target proteins and newly synthesized azo compounds. The docking results suggest that the azo compounds have the potential to be formulated into a cancer therapeutic
Free Online Machine Translation in Second Language Learning: Bridging the Divide Between Reality and Thoughts
No full textThis paper presents a study focusing on EFL learners’ use of free online machine translation tools for their language studies. The study aims to explore how language learners perceive the use of the tools for this purpose, assess their comments on how frequently and extensively they think they use the tools, and examine how the tools are actually utilized. It also investigates whether proficiency level is a factor affecting the use of free online machine translation tools in second language learning. To this end, it was designed as convergent parallel mixed-methods research in which the data were collected through a questionnaire on the related issues and stimulated-recall interviews. The participants were 104 EFL learners with pre and upper-intermediate proficiency levels at tertiary level in Türkiye. The findings suggested that the participants used the tools principally for vocabulary to check the meanings of English words, and they were aware of the extent to which their use could be considered as ethical. As for the potential effect of language proficiency, it emerged that there was no significant difference in the use of the tools by the two different language proficiency groups.</jats:p
Ultrasound-assisted dispersive micro solid phase extraction of maneb in water and food samples with new hybrid block copolymer material prior to micro-spectrophotometric analysis
No full textA simple and effective ultrasound-assisted dispersive micro solid-phase extraction (UA-dμSPE) method was developed for the spectrophotometric determination of traces maneb in food and water. In this study, a new hybrid block copolymer poly (vinyl benzyl chloride-b-dimethyl aminoethyl methacrylate) (Pvb-DMA) was synthesized and characterized using techniques such as FTIR, SEM-EDX. The synthesized Pvb-DMA was used as an adsorbent for the extraction of maneb for first time in this study. The effects of different experimental variables such as pH, adsorbent amount, sample volume, eluent type were optimized. The statistical toll factorial design was applied to estimate the individual and combined impact of parameters on the extraction of maneb. The applicability of different solvents such as acetone, methanol, ethanol, tetrahydrofuran, acetonitrile for maneb recovery from adsorbent was tested. The detection and quantification limits were found to be 3.3 ng mL-1 and 10.0 ng mL-1, respectively. In addition, the preconcentration factor and linear range was obtained 300 and 10-500 ng mL-1. The extraction recovery and relative standard deviation were found to be 95 % and 2.8 %, respectively
Demiryolu Sistemlerinin Kritik Bileşenleri Olarak Organizasyonlar Arası Lojistik Bilgi Sistemleri: Bir Yazın Taraması
No full textAğ şeklinde yapılanan tedarik zincirleri, ürün ve malzeme akışlarının yanı sıra stok yönetim süreçleri için gerekli olan bilgi akışlarına destek veren kritik organizasyonel yapılardır. Tedarik zincirlerinde 2000’li yılların başından itibaren elektronik ticaretin etkisiyle şekillenen tedarik zinciri entegrasyon eğilimlerinin temel destekleyici unsurları olan organizasyonlar arası sistemler (OAS) 2010’lu yılların başına kadar büyük ölçüde ikili sistem entegrasyonlarına dayalı olarak yönetilirken, 2010’lu yılların başından 21. yüzyılın ilk çeyreğine kadar olan dönemde web teknolojilerinin gelişimiyle birlikte büyük bir dönüşüm geçirmiştir. Bu çalışmanın temel amacı OAS yazınına ilişkin sistematik bir yazın taraması yürüterek alana ilişkin dönüşümü teorik temelleriyle birlikte incelemektir. Sistematik yazın taraması kapsamında incelenen bilimsel araştırmalar bilimsel araştırma metodolojisinin temel özellikleri, kullanılan yöntemler, araştırmaların yoğunlaştığı alanlar, veri toplama yöntemleri ve bağımlı-bağımsız değişken ilişkileri açısından incelenmiştir. Bunların yanı sıra alan yazında ön plana çıkan çalışmalardan farklı olarak; OAS’ler üzerindeki etkileri, genellikle açıklayıcı araştırma metodolojisine dayanan çok değişkenli istatistiksel yöntemler ve matematiksel modellerle incelenen ve OAS’lerin etki alanlarını temsil eden kavramlar sistematik olarak sınıflandırılarak tematik yoğunlaşma alanları ortaya çıkarılmıştır.</jats:p