Digital Commons Network^™

Fubini Collocation Method For Numerical Solutions Of Differential Equations With Quadratic And Cubic Nonlinearities, Kübra Erdem Bi̇çer, Havva Türkhan

Turkish Journal of Mathematics

In this study, the Fubini collocation method is proposed for the approximate solution of nonlinear differential equations. The method utilizes fundamental relations involving Fubini polynomials and their derivatives, employing collocation points to enhance solution accuracy. Within this framework, the given differential equation is transformed into a system of nonlinear algebraic equations involving the unknown coefficients of the approximate solution. This resulting system is then solved using appropriate numerical techniques to obtain the approximate solution. The effectiveness of the proposed method is demonstrated through several test problems, with accuracy evaluated using absolute error functions. Furthermore, illustrative examples and residual-based error analysis …

The Derivative Of Spectral Function Of The Problem With The Boundary Condition Dependent On Spectral Parameter, Eli̇f Başkaya, Haskiz Coşkun

Turkish Journal of Mathematics

In this study, the computation of the derivative of the spectral function for Sturm-Liouville problem with eigenvalue dependent boundary condition at the finite left end is considered.

Representation Of Inverse Ordered Semigroups By Means Of Symmetric Inverse Semigroups On A Set, Michael Tsingelis

Turkish Journal of Mathematics

A partial one-to-one mapping on a set X is a mapping whose domain is a subset of X. The set of partial one-one mappings on a set X is an inverse semigroup (the symmetric inverse semigroup on X). An element x of an ordered semigroup (S, ·, ≤) is called an inverse element of α ∈ S if α ≤ xαx and x ≤ xαx. An inverse ordered semigroup is an ordered semigroup S for which every element of S possesses an inverse element and the inverse elements of any element of S are in …

Cover And Contents

Turkish Journal of Agriculture and Forestry

No abstract provided.

Jujubenet: A Dual-Stage Spectral Reconstruction Network For Rapid Jujube Moisture Content Estimation, Yalei Xu, Yang Li, Jing Nie, Jingbin Li

Turkish Journal of Agriculture and Forestry

Spectral analysis methods can nondestructively assess the quality of agricultural products but are limited by imaging speed and equipment costs. Therefore, they have not yet been fully integrated into engineering practices. This paper presents JujubeNet, a two-stage hyperspectral reconstruction model for detecting moisture content in jujubes. The first stage utilizes a generative pretrained Pix2Pix generative adversarial network (GAN) to generate RGB images of jujubes that mimic real camera styles and are pixel-to-pixel aligned with hyperspectral images. The second stage uses a transformer-based spectral reconstruction model to achieve hyperspectral reconstruction. Additionally, we developed a moisture content detection model based on hyperspectral …

Effect Of Nettle (Urtica Dioica L.) Seed Powder Supplementation On Some Important Quality Characteristics Of Cakes, Esra İrem Can, Kadi̇r Çebi̇

Turkish Journal of Agriculture and Forestry

The nutritional adjustment of food products has gained popularity in recent years as consumer interest in healthy eating has increased. Cake is a widely consumed cereal-based product containing such key nutrients as carbohydrate, fat, protein, fiber, vitamins, and minerals. In the present study, crust and crumb color, specific volume, microstructure, antimicrobial activity, total phenolic content, antioxidant activity, and sensory analyses were evaluated in four cake groups: a control cake (IT0) and cakes supplemented with 1% (IT1), 3% (IT2), and 5% (IT3) nettle seed powder. The addition of nettle seed powder to the cakes significantly reduced the crust (L*, a* and …

Mango Leaf Disease Detection And Classification Using A Federated Learning Based Lightweight Vision Transformer Model, Vinay Gautam, Prabhjot Kaur, Anand Muni̇ Mishra, Achyut Shankar, Laxman Singh

Turkish Journal of Agriculture and Forestry

The detection and management of horticultural crop diseases is crucial for enhancing productivity, reducing costs, and promoting environmentally sustainable practices. Recently, various techniques have been developed for managing crop-related issues, including leaf diseases and pest control. A centralized control approach has been implemented for disease detection. This centralized system faced significant challenges, including concerns over data privacy and the costs associated with data migration. This study addressed the problems with centralized solutions through a federated learning approach enhanced by the attention mechanism of the vision transformer (ViT). We investigated the key features of the federated learning method and propose a …

Effects Of Different Perfluoroalkyl Substances On Rice Morphology, Physiology, And Biochemistry, Maryam M. Alomran, Muhammad Aqeel, Noreen Khalid, Noreen Akhter, Muhammad Kashif Irshad, Suliman Mohammed Suliman Alghanem, Fahad Mohammed Alzuaibr, Saher Nawaz, Omar Mahmoud Alzoubi, Muhammad Usman Akbar, Ali Noman

Turkish Journal of Agriculture and Forestry

Perfluoroalkyl substances (PFASs) are synthetic organic compounds that have not been extensively studied in natural environments. The current study aimed to explore how PFASs, including perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonate (PFBS), perfluorohexanoate (PFHxA), perfluorotetradecanoate (PFTeDA), and perfluorobutanoate (PFBA), affect rice plants and influence their metabolism. These substances had a notable impact on root and shoot growth, reducing fresh and dry weights across various treatments compared to the control. These attributes were the least affected by PFOS treatment. PFBA treatment had significant adverse effects on chlorophyll a, b, and total chlorophyll levels, followed by the effects of PFHxA and PFTeDA. …

Effects Of Different Mixing Ratios Of Common Vetch And Oats On Forage Yield And Quality, Meli̇h Okcu, Sedat Severoğlu, İbrahi̇m Kavuncu

Turkish Journal of Agriculture and Forestry

This study investigates the optimal mixing ratios of common vetch (Vicia sativa L., CV) and oats (Avena sativa L., O) for enhanced forage yield and quality in the ecological conditions of Erzurum Province. The research was conducted over two growing seasons with three replications in a randomized complete block design (RCBD). Specifically, three common vetch cultivars (Gülhan, Albayrak, Kubilay) and one oat cultivar (Kupa) were evaluated by sowing as sole crops and in different ratios (25% vetch + 75% oat, 50% vetch + 50% oat, 75% vetch + 25% oat). The analyzed parameters included hay forage yield (HFY), dry matter …

Cover And Contents

Turkish Journal of Biology

No abstract provided.

Identification Of Epigenetic Monotherapy Candidates In Taxane-Resistant Crpc, Buse Cevatemre, İpek Bulut, Ezgi̇ Karyemez, Ceyda Açilan

Turkish Journal of Biology

Background/aim: Taxane resistance remains a significant challenge in the effective treatment of castration-resistant prostate cancer (CRPC). Given the association of epigenetic regulation with chemotherapy resistance and cancer progression, this study aims to identify epigenetic vulnerabilities in two CRPC cell lines (DU145 and 22Rv1) established as resistant to two different taxanes, docetaxel (Dtx) and cabazitaxel (Cbz), using a small-molecule screening approach. Materials and methods: A small-molecule library targeting epigenetic regulators, including histone deacetylases (HDAC), histone methyltransferases, histone demethylases, bromodomain proteins, deoxyribonucleic acid methyltransferases, protein arginine deiminase, and histone acetyltransferase was utilized. Drug screening was performed on parental and taxane-resistant CRPC cell …

Eucommia Ulmoides Extract Attenuates Oxidative Stress And Promotes Melanogenesis Via Wnt/Β-Catenin Signaling In B16 Cells And Mice, Xiaojin Liu, Yaqian Qiu, Xiaobing Lv, Lei Chang, Tiancheng Ji, Yefan Gu, Shuyue Chen

Turkish Journal of Biology

Background/aim: Oxidative stress is a major contributor to melanocyte dysfunction and hair graying by impairing key signaling pathways. Eucommia ulmoides bark extract (EUE), rich in antioxidant phytochemicals, has shown potential in combating oxidative damage. This study investigated the protective and promelanogenic effects of EUE under hydrogen peroxide (H₂O₂)-induced oxidative stress, with a focus on the Wnt/β-catenin signaling pathway. Materials and methods: An oxidative stress model was established using B16 cells and a C57BL/6 mouse hair follicle model. Results: EUE significantly improved melanocyte survival and reduced intracellular reactive oxygen species (ROS). Mechanistically, EUE activated the Wnt/β-catenin pathway, leading to upregulation of …

Cover And Content

Turkish Journal of Chemistry

No abstract provided.

Enhancing Analytical Performance Of Tyrosinase-Based Sensors With Nanoparticles For Detection Of Isoproterenol, Aysel Oktay, Sevi̇nç Kurbanoğlu, Gülsüm Gündoğdu, Cem Bülent Üstündağ, Frieder W. Scheller, Aysu Yarman

Turkish Journal of Chemistry

In this work, electrochemical biosensors utilizing tyrosinase (Tyr) for the detection of the nonselective beta-adrenergic agonist isoproterenol (ISO) are presented. Three different configurations for immobilizing Tyr on a graphite electrode (GE) are compared: (1) GE modified with poly(diallyldimethylammonium chloride) (PDADMAC), PDADMAC/Tyr/GE; (2) PDADMAC combined with iridium nanoparticles (IrNPs) in a stepwise preparation, resulting in PDADMAC/IrNPs/Tyr/GE; and (3) a composite of PDADMAC and IrNPs mixed with Tyr at a 1:1 (v:v), forming PDADMAC/(IrNPs-Tyr)/GE. Surface morphology was characterized using scanning electron microscopy (SEM). Cyclic voltammetry (CV) and amperometry were applied to characterize the biosensor’s performance. Within the linear range of 5 μM …

Synthesis, Characterization, And Theoretical Study Of New Cocrystals And Charge-Transfer Compounds, Zari̇fe Si̇bel Şahi̇n, Zeki̇ Kartal

Turkish Journal of Chemistry

This study used single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, theoretical nuclear magnetic resonance (NMR), and theoretical ultraviolet spectroscopy to characterize 3 newly synthesized crystalline compounds. Additionally, the nonlinear optical, highest occupied molecular orbital energies, lowest occupied molecular orbital energies, band gap, molecular electrostatic potential, and thermodynamic parameters of the 3 crystalline compounds were examined. The strong correlation between experimental IR spectra and theoretical NMR chemical shifts confirmed the accuracy of computational predictions. The molecular formulas of the 3 newly synthesized crystalline compounds, each containing different ligand molecules, were: C8H14O4·2(C6H4N2), C5H7N2·NCS, and Ni(CN)4·2(C5H7N2)·2(H2O) for compounds 1, 2, and 3, …

New Bis-Piperazine Derivatives: Synthesis, Characterization (Ir, Nmr), Gamma-Ray Absorption, Antimicrobial Activity, Molecular Docking And Dynamics Study, Yasemi̇n Ünver, Arzu Coşkun, Fati̇h Çeli̇k, Hali̇l İbrahi̇m Güler, Kadri̇ye İnan Bektaş

Turkish Journal of Chemistry

A series of novel bis-piperazine derivatives (2a–2f) were synthesized and structurally characterized via Fourier transform-infrared and nuclear magnetic resonance spectroscopic techniques. Their gamma-ray shielding efficiencies were investigated through simulations on the Monte Carlo-based Geant4-GATE platform, and the results were benchmarked against data obtained from the XCOM and Phy-X software. A simulation model incorporating an NaI scintillation detector and a point gamma source was developed. Key shielding parameters, including mass attenuation coefficient, linear attenuation coefficient, half-value layer, and mean free path (MFP), were evaluated at gamma energies of 80, 120, 662, 1173, and 1332 keV. Additionally, the energy absorption buildup factor …

Synthesis Of Biogenic Silver Nanoparticles From Apricot Kernel Extracts For The Colorimetric Determination Of Gold, Ayça Gi̇rgi̇n, Hi̇lal Akbiyik, Buse Tuğba Zaman, Omid Nejati, Ayça Bal Öztürk, Gülten Çeti̇n, Sezgi̇n Bakirdere

Turkish Journal of Chemistry

Gold is abundant in nature, however, precise and reliable analytical methods for its detection are required stemming from its increasing prevalence in environmental, biological, and industrial systems, as well as the growing interest in understanding its function in living organisms and its effects on human health. This study investigates the use of biogenically synthesized silver nanoparticles (AgNPs) for the preconcentration and determination of gold ions prior to determination by UV-Vis spectrophotometry. AgNPs were synthesized by reducing silver nitrate through the use of an apricot kernel extract as both reducer and stabilizer agent. The colloidal yellowish AgNPs interacted with gold ions, …

Structural Categorization And Identification Of Electrostatic Interactions In Two Proposed Human Serum Albumin Dimerization Patterns And Dipyridamole Interaction, Haluk Çeti̇nok, Veyi̇s Karakoç, Erol Erçağ, Yusuf Meli̇h Şekerer, Hasan Demi̇rci̇

Turkish Journal of Chemistry

Human serum albumin (HSA) is a ubiquitous, multifunctional protein responsible for the systemic distribution of both endogenous metabolites and exogenous pharmaceuticals. Its inherent properties, particularly its ability to seep into tissues and its multiple ligand-binding sites, have rendered HSA an attractive vehicle for nanoparticle-based drug delivery systems, particularly for cancer targeting. In this study, we present high-resolution crystallographic data revealing two distinct dimerization patterns of HSA (Protein Data Bank [PDB] ID: 9V61) obtained under high-concentration crystallization conditions, along with results from dipyridamole docking. Both dimer types demonstrate extensive interface areas and a significant number of electrostatic interactions. Comparative analysis with …

Α-Glycosidase Activity Of Novel Coumarin–Triazole–Coumarin Dyads, Ersi̇n Şi̇ri̇n, Esra Sevi̇mli̇, Gökçe Seyhan, Burak Barut, Yunus Kaya, Baybars Köksoy

Turkish Journal of Chemistry

Novel coumarin–triazole–coumarin dyads were synthesized and characterized, and their α-glycosidase inhibitory activities were evaluated spectrophotometrically. Compound 4e exhibited the most pronounced inhibitory effect, with an IC50 value of 38.98 ± 0.77 μM. The IC50 values for 4d and 4a were 93.55 ± 1.70 μM and 95.04 ± 3.55 μM, respectively. The Lineweaver–Burk plot showed that 4e inhibited α-glycosidase in a mixed type. In addition, the Ki value obtained from the Dixon plot was 19.95 ± 0.15 μM for α-glycosidase.

Utilization Of Dual Catalysts For High-Yield Boron Nitride Nanotube Synthesis Via Chemical Vapor Deposition, Şaban Kalay

Turkish Journal of Chemistry

The direct synthesis of boron nitride nanotubes (BNNTs) via chemical vapor deposition (CVD) in high-temperature furnaces remains highly challenging due to difficulties in optimizing key experimental parameters such as synthesis temperature and catalyst composition. These challenges often result in uncontrolled growth behavior, adversely affecting the quality and yield of the BNNTs. In this study, colemanite was effectively utilized as a boron source for the high-yield synthesis of directionally aligned BNNTs. The synthesis was carried out using a CVD method that used a dual-catalyst system comprising Fe2O3 and MgO in conjunction with a silicon carbide template under high-temperature conditions. The resulting …

First-Principles And Deep Learning Frameworks To Predict The Electronic, Magnetic And Electrical Properties Of V-Doped Sic Nanotube, Debarati Dey Roy, Sevda Rzayeva, Sevinj Guluzade, Vusala Nabi Jafarova

Turkish Journal of Physics

Nowadays, with the miniaturization of nanoindustry, we are increasingly interested in doping effects for nanotube systems. In this study, based on density functional theory (DFT) and local spin density approximation (LDA) methods within Hubbard U corrections, the electronic, magnetic and electrical properties of single-wall silicon carbide nanotubes doped with vanadium were theoretically studied. Although the undoped SiC system is nonmagnetic, the V-doped SiC nanotube induces magnetism and the total magnetic moment of this magnetic material is equal to ~1 µB. Density of states calculations indicated that the magnetization of SiC:V single-wall nanotubes mainly comes from the 2p orbitals of carbon …

Cover And Contents

Turkish Journal of Medical Sciences

No abstract provided.

Endocrine Disruptors, Insulin Resistance, And Diabetes, Meri̇ç Coşkun, Ethem Turgay Ceri̇t, Tuğba Barlas, Alev Eroğlu Altinova

Turkish Journal of Medical Sciences

Endocrine-disrupting chemicals (EDCs) are compounds that interfere with hormone synthesis, secretion, metabolism, or excretion. Evidence indicates that increased exposure to EDCs is associated with insulin resistance and, most notably, type 2 diabetes worldwide. This suggests a diabetogenic effect that is independent of obesity, underscoring the complex mechanisms and broad impact of EDCs on metabolic health. Key pathways include hormone mimicry and antagonism, altered hormone metabolism, inflammatory responses, and mitochondrial dysfunction. This review summarises the mechanisms through which EDCs contribute to these conditions and evaluates the epidemiological and experimental evidence supporting these associations.

Cover And Contents

Turkish Journal of Medical Sciences

No abstract provided.

Relcovaptan: A Promising Therapeutic Agent In Traumatic Spinal Cord Injury That Acts By Modulating Newly Identified Transcriptional Regulators Of Aquaporins Compared To Tolvaptan, Şeyma İş, Duygu Ceman, Meri̇h İş, Neşe Keser, Şaban Teki̇n

Turkish Journal of Medical Sciences

Background/aim: Every year, hundreds of thousands of people worldwide suffer from traumatic spinal cord injury (tSCI), which causes irreversible damage, edema, and inflammation. Despite its devastating impact, no safe and effective medication is available. Edema formation is one of the earliest pathological events in tSCI, beginning within minutes after injury. Cytotoxic edema progresses to vasogenic edema, exacerbating irreversible damage. Our study aimed to investigate a therapeutic approach targeting cytotoxic edema in the acute phase of tSCI to improve treatment outcomes. Aquaporins (AQPs) are crucial in edema formation and tSCI pathogenesis. Vasopressin, also known as the antidiuretic hormone, modulates Aqp expression …

Subjective Memory Complaints Among Older Adults In Türkiye: Prevalence And Contributing Factors, Mustafa Çeti̇n, Zehra Sarikaya Demi̇rbaş, Mehmet İlki̇n Naharci

Turkish Journal of Medical Sciences

Background/aim: Subjective memory complaints (SMCs), defined as self-perceived declines in memory performance, are common among older adults and may serve as early indicators of neurocognitive impairment. Despite their clinical relevance, no previous studies have examined the prevalence and associated factors of SMCs in Türkiye.

Materials and methods: A total of 500 community-dwelling older adults were included in this retrospective, cross-sectional, observational study; all underwent a comprehensive geriatric assessment at a tertiary-level outpatient clinic. Participants with an mini-mental state examination score ≥27, independence in instrumental activities of daily living, and no diagnosis of mild cognitive impairment were assessed for SMCs. Sociodemographic …

Impact Of Patient Education Meetings On Disease Knowledge In Chronic Urticaria Patients, Nazan Beyhan, Hati̇ce Eylül Bozkurt Yilmaz, Asli Çi̇ftci̇, Ömür Aydin, Di̇lşad Mungan, Betül Ayşe Si̇n, Gülfem Eli̇f Çeli̇k, Murat Türk, İnsu Yilmaz, Sevi̇m Bavbek

Turkish Journal of Medical Sciences

Background/aim: Chronic urticaria (CU) is a manageable disease with symptoms of itching and visible lesions that can disrupt daily life and reduce quality of life. The severity of symptoms can vary, and the cause is often unknown. Concerns among patients as regards to treatment and prognosis highlight the need for disease education to enhance self-management and reduce anxiety. The present study examines the effect of disease education on the knowledge level of CU patients.

Materials and methods: Patients with CU who presented to the allergy clinics of two tertiary university hospitals were invited to inperson education sessions including slide presentations …

Assessing The Efficiency Of Methods To Teach Adolescents About Testicular Cancer And Testicular Self-Examination, Ayşe Gül Güven, Laden Jafari̇, Murat Doğuş Günel, Özlem Akbulut

Turkish Journal of Medical Sciences

Background/aim: Due to the increasing incidence of testicular cancer (TC), early testicular self-examination (TSE) in adolescent males is crucial for early detection and treatment. However, it is uncertain which method is best for teaching about TC and TSE in this age group. This study aimed to assess the effectiveness of formal (face to face with model) and informal (video presentation) approaches in male adolescents about TC and TSE.Material and methods: This intervention study was conducted in 2 high schools, and included a study group (n = 142) and a control group (n = 102). In the study group, a video …

Biochar Derived From Different Sources Ameliorates The Phytochemical And Physiological Characteristics Of Foxtail Millet (Setaria Italica) Under Water Stress, Mohammad Keshavarz, Ehsan Bijanzadeh, Hamid Reza Boostani

Turkish Journal of Botany

Organic material, such as biochar, can improve soil fertility and crop yield under water stress. A pot experiment was conducted to consider the effects of biochar on the pigment content, enzyme activity, physiological characteristics, and nutrient uptake of foxtail millet under water stress. Plants were tested under normal, mild, and severe irrigation regimes (100%, 75%, and 50% field capacity, respectively) using different biochar sources (licorice root biochar (LRB), cow manure biochar (CMB), cotton residue biochar (CRB), and municipal waste biochar (MWB)) and a control without fertilizer. Under severe water stress, the chlorophyll a content and total chlorophyll increased by 137.3% …

Protective Role Of Salicylic Acid Against Abiotic Stresses In Horticultural Crops: A Review, Faisal Hayat, Xiaoyun Zhang, Mohammed Alyafei, Fareeha Shireen, Ummara Khan, Sumeera Asghar, Sezai̇ Erci̇şli̇, Karthishwaran Kandhan, Mohamed S. Sheteiwy, Yali Zhang, Xiaoyan Lu

Turkish Journal of Botany

Environmental stressors such as drought, floods, salinity, extreme temperatures, and heavy metal toxicity are major threats to horticultural plants because they disrupt plant physiological mechanisms, leading to reduced yield and quality. Salicylic acid (SA) is a plant hormone that regulates various physiological and biochemical functions in plants. Moreover, it regulates hormonal balance, enhances the absorption of essential nutrients, promotes photosynthesis and the production of antistress compounds, and improves stress resistance. This comprehensive review explains several physiological and biochemical activities that are affected by SA under stressful conditions, such as stomatal regulation, antioxidant defense systems, osmotic adjustment and gene expression regulation. …