DSpace @ Recep Tayyip Erdoğan Üniversitesi Akademik Açık Arşiv
Not a member yet
12203 research outputs found
Sort by
Molecular insights into salt stress response in perennial ryegrass (Lolium perenne L.): gene expression and growth performance assessment
No full textPerennial ryegrass (Lolium perenne L.) is a key perennial species with significant agricultural and ecological importance. Salt stress adversely affects plant growth by inducing oxidative stress, reducing biomass accumulation, and impairing physiological functions. In this study, calcium chloride, magnesium chloride, magnesium sulfate, and sodium sulfate treatments were applied to evaluate their effects on salinity-induced molecular and physiological responses. The effects of these treatments on the expression of salt stress–responsive genes Ascobate Peroxidase (APX), Glutathione Reductase (GR), Heavy Metal ATPase (HMA), and Phytochelatin Synthase (PCS) were analyzed using quantitative real-time PCR (qRT-PCR). In addition, agronomic traits including seedling length, fresh and dry weight, plant water content, and dry matter ratio were evaluated. Higher salinity increased stress-related gene expression, but this was not enough to maintain growth or water retention. In contrast, mild to moderate salt stress resulted in more balanced gene expression, reduced physiological damage, and improved plant development. These findings provide insights into the molecular and physiological responses of perennial ryegrass to different salt sources and may support future research on improving salinity tolerance in forage species
Exploring the effect of ultrasonic vibrations on the thermohydraulic performance in a minichannel heat sink: Numerical analysis of experimental results
No full textUltrasonic ( US ) applications in thermal systems contribute to the disruption of the boundary layer and the increase of mixing in fluids, thus improving overall system performance. Utilizing this phenomenon, this study aimed to investigate the effect of US power and various heat inputs (Q̇) on the thermohydraulic performance and entropy generation in a rectangular minichannel heatsink. The effect of US on MCHSs has not been comprehensively investigated in the literature, both experimentally and numerically. This study aims to fill this gap and provide a scientific contribution to thermohydraulic performance and entropy generation. For this purpose, a test rig was designed and built. The heatsink was made of copper, and a 27.8 kHz US transducer with P us = 9.9 W input power was applied to the top wall of the heatsink. ANSYS Fluent 2024 R1 was used to solve the governing equations in numerical analysis. The analyses were performed under laminar flow conditions with a range of Reynolds numbers ( Re ). The results obtained from the experiments and numerical simulations demonstrated reasonable agreement, both with each other and with literature correlations. The results showed that the average Nusselt number ( Nu ) increased by 14% when Q̇ was increased from 50 W to 60 W, and by 13% when US was applied. The US application provides a more homogeneous temperature distribution in the channel and header, especially at low Re . It was determined that Q̇ did not affect the friction occurring in the system, but the friction effect of US was more dominant, especially at low Re . Increasing the Q̇ to the system worsened the performance by increasing thermal entropy generation (Ṡgen, thermal) up to 30%. In contrast, the use of US improved the performance by reducing Ṡgen, thermal by up to 4.5%. The situation was reversed for frictional entropy generation (Ṡgen, frictional), where increasing Q̇ yielded a decrease of up to 5%. However, when the US was applied, there was a 38% increase in Ṡgen, frictional at Re = 84 for each Q̇ and Ṡgen, thermal is more dominant than Ṡgen, frictional. In other words, compared with conventional MCHSs without US , the proposed US -assisted system increased the average Nu by 13% and reduced the Ṡgen, thermal by up to 4.5%, resulting in a significant improvement in performance
Oligosaccharides from Scorzonera yildirimlii and S. zorkunensis, and their potential antimicrobial, enzyme inhibition, cytotoxic effect, and in silico study
No full textIn this study, the phytochemical investigation of Scorzonera yildirimlii and S. zorkunensis led to the isolation and identification of eight new oligosaccharide constituents (1–8). Their structures were elucidated through comprehensive spectroscopic analysis (NMR, FT-IR, and mass spectrometry) and comparison with literature data. The structure of isolated compounds were O-α-D-Glcp-(1 → 2)-O-β-D-Fruf-(3 → 1)-O-myo-inositol (1), O-α-D-Glcp-(1 → 2)-O-β-D-Fruf-(3 → 1)-O-epi-inositol (2), O-β-D-Fruf-(2 → 6)-O-α-D-Glcp-(1 → 1)-O-β-D-Glcp (3), O-β-D-Fruf-(2 → 6)-O-α-D-Glcp-(1 → 1)-O-β-D-Galp (4), O-β-D-Fruf-(2 → 6)-O-β-D-Fruf-(2 → 6)-O-α-D-Glcp-(1 → 1)-O-β-D-Glcp (5), O-β-D-Fruf-(2 → 6)-[O-β-D-Glcp-(1 → 4)]-O-α-D-Glcp-(1 → 1)-O-β-D-Glcp (6), O-β-D-Fruf-(2 → 6)-[O-β-D-Glcp-(1 → 4)]-3-OCH3-O-α-D-Glcp-(1 → 1)-O-β-D-Glcp (7), and O-β-D-Fruf-(2 → 6)-[O-β-D-Glcp-(1 → 4)]-O-α-D-Glcp-(1 → 4)-O-α-D-Glcp-(1 → 2)-O-β-D-Fruf (8). The antimicrobial activities of all the isolated compounds (1–8) were investigated against six microorganisms. Compounds 2 and 3 were effective against Mycobacterium smegmatis at minimum inhibitory concentrations (MICs) of 3.13 μg/mL and 3.44 μg/mL, respectively, compared with streptomycin (MIC = 4.0 μg/mL). The enzyme-inhibitory properties of the isolated compounds (1–8) were evaluated against tyrosinase and α-glucosidase. Among the tested compounds, 4 (39.78 ± 10.29 %) exhibited inhibitory activity against tyrosinase, while compound 2 (68.04 ± 4.68 %) exhibited inhibitory activity against α-glucosidase. In silico studies of 1–8 showed the best predicted binding affinities for the Trehalose-LpqY complex in the range of −11.088 kcal/mol to −14.297 kcal/mol, compared to streptomycin (−6.638 kcal/mol). Compounds 1–8 exhibited almost no cytotoxic activity against L-929 cells, further supporting their potential for therapeutic use
Unravelling the role of indigenous PGPB in corm development and mineral acquisition of Freesia hybrida: A multivariate perspective
No full textThis study investigated the effects of indigenous plant growth-promoting rhizobacteria (PGPR) consortia on corm development, the physiological attributes and nutrient acquisition of Freesia hybrida grown under greenhouse conditions. Five PGPR consortia (A1-A5) were evaluated in comparison with chemical fertiliser and control treatments. The results revealed that A2 and A4 consortia significantly enhanced corm dry weight (by 22%-28%), diameter (by 18%) and chlorophyll content (by 15%) relative to the control, while A1 and A4 promoted cormlet formation. Both A2 and A4 also increased macronutrient uptake, particularly nitrogen (by 21%), potassium (by 24%) and calcium (by 19%), indicating improved root-soil interaction and nutrient use efficiency. Principal component analysis (PCA) and correlation matrices confirmed a distinct clustering of A2 and A4 treatments, demonstrating consistent broad-spectrum effects on the morphological and nutritional parameters. The findings highlight the potential of native PGPR formulations as sustainable biofertilizers capable of reducing chemical fertiliser dependency and improving soil health in ornamental bulb production systems
Therapeutic effect of arginine, glutamine and β-hydroxy β-methyl butyrate mixture as nutritional support on dss-induced ulcerative colitis in rats
No full textBackground: Ulcerative colitis (UC) is characterized by chronic mucosal inflammation, oxidative stress, and disruption of intestinal metabolic homeostasis. Immunomodulatory nutrients such as arginine, glutamine, and β-hydroxy β-methylbutyrate (HMB) have shown potential benefits; however, their combined molecular effects on UC remain insufficiently defined. Objective: To investigate the individual and combined effects of arginine, glutamine, and HMB on inflammatory and metabolic gene expression, oxidative stress markers, and histopathological outcomes in a dextran sulfate sodium (DSS)-induced colitis model. Methods: Female Sprague Dawley rats were assigned to six groups: control, DSS, DSS + arginine, DSS + glutamine, DSS + HMB, and DSS + mixture. Colitis was induced using 3% DSS. Colon tissues were examined histologically, serum MDA, MPO, and GSH levels were quantified, and mRNA expression of IL6, IL10, COX2, NOS2, ARG2, CCR1, and ALDH4A1 was measured by RT-qPCR. Pathway enrichment analyses were performed to interpret cytokine and metabolic network regulation. Results: DSS induced severe mucosal injury, elevated MDA and MPO, reduced GSH, and significantly increased IL6, COX2, NOS2, ARG2, and CCR1 expression. Glutamine demonstrated the strongest anti-inflammatory and antioxidant effects by decreasing IL6 and COX2 and restoring GSH. Arginine primarily modulated nitric oxide–related pathways, whereas HMB increased ALDH4A1 expression and metabolic adaptation. The combination treatment produced more balanced modulation across inflammatory, chemokine, and metabolic pathways, consistent with enrichment results highlighting cytokine signaling and amino acid metabolism. Histopathological improvement was greatest in the mixture group. Conclusions: Arginine, glutamine, and HMB ameliorate DSS-induced colitis through coordinated regulation of cytokine networks, oxidative stress responses, and metabolic pathways. Their combined use yields broader and more harmonized therapeutic effects than individual administration, supporting their potential as targeted immunonutritional strategies for UC. Rather than targeting a single inflammatory mediator, this study was designed to test whether combined immunonutrient supplementation could promote coordinated regulation of cytokine signaling, oxidative stress responses, and metabolic adaptation, thereby facilitating mucosal repair in experimental colitis
The effect of symptom severity on life satisfaction and happiness in patients receiving chronic hemodialysis treatment: descriptive and cross-sectional research
No full textIntroduction: It is known that patients receiving HD treatment experience many symptoms alone or in combination, negatively affecting their life satisfaction and happiness levels. This study was conducted to determine the effect of symptom severity on life satisfaction and happiness in patients receiving chronic hemodialysis treatment. Method: A descriptive and cross-sectional study was conducted between April and May 2023 with 239 patients receiving treatment in four hemodialysis centers in a province in northeastern Turkey. The data were collected by face-to-face interview technique using the “Descriptive Information Form,” “Dialysis Symptom Index (DSI),” “Satisfaction with Life Scale (SWLS),” and “Happiness Scale (HS).”. Results: A statistically significant difference was found between gender, exercise status, and the presence of secondary disease and HS and DSI (p < 0.05). At the same time, a significant difference was found between marital status and the SWLS and HS and between income level and smoking status and the SWLS (p < 0.05). There was a significant relationship between DSI and SWLS and HS, and DSI had a predictive effect on life satisfaction and happiness scale ((Formula presented.), (Formula presented.)). Conclusion: Symptom severity was below moderate, life satisfaction was reasonable, and happiness level was above average in patients receiving chronic hemodialysis treatment. A comprehensive assessment of multiple symptoms and effective symptom management is recommended in patients receiving hemodialysis
Colorectal cancer in metabolic dysfunction-associated steatotic liver disease: An international Delphi consensus statement
No full textBackground Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide. Epidemiological evidence indicates that MASLD is associated with an increased risk of developing colorectal cancer (CRC). MASLD and CRC share many common risk factors and pathophysiological mechanisms, but an optimal strategy for identifying and managing CRC risk in individuals with MASLD remains lacking. Objective This study aimed to achieve consensus on the risk of CRC in individuals with MASLD. Design A Delphi survey was conducted by a multidisciplinary panel of 35 international experts from diverse medical fields across Asia, Europe, North America, South America, Oceania and Africa. Experts evaluated 17 statements across three domains: epidemiology, pathogenesis and management. Results Consensus was achieved on all 17 statements. MASLD is associated with an increased risk of CRC, and metabolic burden further increases this risk. Furthermore, the severity of MASLD is associated with worse outcomes in patients with MASLD and CRC. The gut-liver axis and gut dysbiosis play key roles in the development of MASLD and CRC, while leptin and adiponectin may also be involved. Weight loss with lifestyle interventions, early CRC screening, bariatric surgery and use of GLP-1 receptor agonists are highlighted as potential risk-reduction strategies. Conclusion The expert panel emphasises the need for greater clinical vigilance for CRC among individuals with MASLD. This consensus supports a paradigm shift towards earlier, risk-adapted screening and integrated metabolic management to reduce the burden of CRC in the MASLD population
A comparative analysis of botanical extracts from rosmarinus officinalis, nigella sativa, lippia citriodora, and origanum vulgare for optimizing rotifer (brachionus plicatilis) culture
No full textDespite progress in artificial diets, live rotifers (Brachionus plicatilis) remain essential for larval fish in marine hatcheries due to their superior digestibility, requiring additives to ensure a healthy culture. This study investigated the effects of water-based extracts from Rosmarinus officinalis (rosemary), Nigella sativa (black cumin), Lippia citriodora (lemon grass), and Origanum vulgare (thyme) on rotifer culture performance. Rotifers were cultured for 29 days with extracts at 0.25, 0.50, and 1.00 ppm and compared to a control group. All variables (extract, concentration, and time) significantly affected performance (P<0.05). The 1.00 ppm concentrations of R. officinalis and N. sativa proved most effective, yielding the highest rotifer densities (2.4×105 individuals L-1). These groups also exhibited superior reproductive performance, measured by the proportion of egg-carrying females, and showed significant dose-dependent changes in swimming patterns. These findings demonstrate that 1.00 ppm extracts of rosemary and black cumin are viable, natural additives for optimizing rotifer productivity. This approach offers a sustainable method to enhance live feed quality, potentially providing significant advantages for the early larval feeding stages in marine aquaculture
Impact of environmental policies, oil market dynamics, and R&D on renewable energy generation, consumption, and transition
No full textThe transition to renewable energy is a global imperative for achieving sustainable development and mitigating climate change. However, the pace of this transition is often challenged by the complex interplay of environmental policies, volatile oil market dynamics, and research and development (R&D). Utilizing a panel dataset from 1990 to 2020, we employ a fully modified ordinary least squares (FMOLS) technique to examine how these factors affect renewable energy generation, consumption, and comprehensive energy transition in G10 countries. The study’s major findings reveal that global climate policy uncertainties increase renewable energy consumption and accelerate the energy transition but hinder renewable energy generation. Domestic stringent environmental policies promote renewable energy consumption and transition, and are associated with a decline in generation. Higher oil supply negatively impacts energy consumption, generation, and transition, while oil price fluctuations positively affect renewable energy consumption but negatively affect its generation. Rising aggregate demand is found to reduce both renewable energy consumption and the pace of energy transition. R&D supports energy consumption, generation, and transition. The study concludes that a balanced approach, combining stringent adaptable environmental policies, economic stability, and innovation-driven R&D, is critical for a successful energy transition. Policymakers should focus on creating a supportive framework that includes incentives for R&D, demand-side subsidies, and flexible environmental standards to strengthen the renewable energy transition
