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Functionality modulation of starch from lotus rhizome using single and dual physical modification
(Elsevier, 2024) Dhull, Sanju Bala; Antika, Chandak; Gökşen, Gülden; Chawla, Prince; Al Obaid, Sami; Ansari, Mohammad Javed
The effects of ultrasonication (US) assisted by pre- and post-treatment of heat-moisture treatment (HMT) on physicochemical, rheological, pasting, digestive, and thermal properties of lotus rhizome (LR) starch were investigated in this study. All treatments decreased the swelling power, amylose content, and peak viscosity except for the ultrasonicated sample when compared with native LR starch. All treatments showed similar diffraction patterns with different intensities. FTIR spectra characteristic peaks did not emerge or disappear after single and dual modifications. Storage modulus (G′) is greater than loss modulus (G″) for all LR starch gel samples demonstrating their elastic character. Moreover, ΔHgel (253.1–303.7 J/g) increased in all treatments. Dual modification (HMT & US) significantly enhanced resistant starch and reduced SDS in LR starches. These results could be beneficial for promoting ultrasound processing for potential uses in the food industry and starch production.
Evaluating the simultaneous electrochemical determination of antineoplastic drugs using LaNiO3/g-C3N4@RGH nanocomposite material
(Elsevier, 2024) Bouali, Wiem; Erk, Nevin; Sert, Buse; Harputlu, Ersan
A novel electrochemical sensor based on LaNiO3/g-C3N4@RGH nanocomposite material was developed to simultaneously determine Ribociclib (RIBO) and Alpelisib (ALPE). Ribociclib and Alpelisib are vital anticancer medications used in the treatment of advanced breast cancer. The sensor exhibited excellent electrocatalytic activity towards the oxidation of RIBO and ALPE, enabling their simultaneous detection. The fabricated sensor was characterized using various techniques, including energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), which confirmed the successful synthesis of the LaNiO3/g-C3N4@RGH composite material. Electrochemical characterization revealed enhanced conductivity and lower resistance of the modified electrode compared to the bare electrode. The developed sensor exhibited high repeatability, reproducibility, stability, and selectivity toward RIBO detection. Furthermore, the sensor displayed high sensitivity with low detection limits of 0.88 nM for RIBO and 6.1 nM for ALPE, and linear ranges of 0.05–6.2 μM and 0.5–6.5 μM, respectively. The proposed electrochemical sensor offers a promising approach for simultaneously determining RIBO and ALPE in pharmaceutical formulations and biological samples with recovery data of 98.7–102.0 %, providing a valuable tool for anticancer drug analysis and clinical research.
Energy poverty and health in Turkey: Evidence from Longitudinal data
(Elsevier, 2024) İpek, Egemen; İpek, Özlem
This study critically examines the effect of energy poverty on health in Turkey between 2018 and 2021 using the Income and Living Conditions Survey Longitudinal Micro Data Set. It considers the multidimensional structure of household energy poverty and its individual effects on health, resulting in several significant findings. Firstly, the multidimensional energy poverty index at the household level is obtained as a continuous variable using principal component analysis, considering subjective and objective indicators of energy poverty. Secondly, the impact of energy poverty on health at the individual level and the effect of several socioeconomic variables, including unobserved heterogeneity, are estimated with the random effects ordered logit model. Finally, commonly used measures of energy poverty in the literature and their health impacts are compared. The robustness analysis results show that the model's goodness of fit is highest when the multidimensional energy poverty index is constructed using principal component analysis. In addition, the analysis results show that unobserved heterogeneity across individuals significantly impacts health. These results indicate that decentralized policies should be implemented to increase policy effectiveness in combating energy poverty.
Dualities over the cross product of the cyclic groups of order 2
(American Institute of Mathematical Sciences, 2024) Dougherty, S.T.; Şahinkaya, Serap
We determine the number of symmetric dualities on the s-fold cross product of the cyclic group of order 2, which is the additive group of the finite field F2s. We show that the ratio of symmetric dualities over all dualities goes to 0 as s goes to infinity.We also prove a surprising result that given any two binary codes C and D of the same length n with |C||D| = 2n, then viewing them as groups there is a symmetric duality M with CM = D, which also relates their weight enumerators as additive codes in a group via the MacWilliams relations. Using this theorem we show that any additive code in this setting can be viewed as an additive complementary dual code of length 1 with respect to some duality.
Enhancing vehicle detection in intelligent transportation systems via autonomous UAV platform and YOLOv8 integration
(Elsevier, 2024) Bakırcı, Murat
This study highlights the evolving landscape of object detection methodologies, emphasizing the superiority of deep learning-based approaches over traditional methods. Particularly in intelligent transportation systems-related applications requiring robust image processing techniques, such as vehicle identification, localization, tracking, and counting within traffic scenarios, deep learning has gained substantial traction. The YOLO algorithm, in its various iterations, has emerged as a popular choice for such tasks, with YOLOv5 garnering significant attention. However, a more recent iteration, YOLOv8, was introduced in early 2023, ushering in a new phase of exploration and potential innovation in the field of object detection. Consequently, due to its recent emergence, the number of studies on YOLOv8 is extremely limited, and an application in the field of Intelligent Transportation Systems (ITS) has not yet found its place in the existing literature. In light of this gap, this study makes a noteworthy contribution by delving into vehicle detection using the YOLOv8 algorithm. Specifically, the focus is on targeting aerial images acquired through a modified autonomous UAV, representing a unique avenue for the application of this cutting-edge algorithm in a practical context. The dataset employed for training and testing the algorithm was curated from a diverse collection of traffic images captured during UAV missions. In a strategic effort to enhance the variability of vehicle images, the study systematically manipulated flight patterns, altitudes, orientations, and camera angles through a custom-designed and programmed drone. This deliberate approach aimed to bolster the algorithm's adaptability across a wide spectrum of scenarios, ultimately enhancing its generalization capabilities. To evaluate the performance of the algorithm, a comprehensive comparative analysis was conducted, focusing on the YOLOv8n and YOLOv8x submodels within the YOLOv8 series. These submodels were subjected to rigorous testing across diverse lighting and environmental conditions using the dataset. Through tests, it was observed that YOLOv8n achieved an average precision of 0.83 and a recall of 0.79, whereas YOLOv8x attained an average precision of 0.96 and a recall of 0.89. Furthermore, YOLOv8x also outperformed YOLOv8n in terms of F1 score and mAP, achieving values of 0.87 and 0.83 respectively, compared to YOLOv8n's 0.81 and 0.79. These outcomes of the evaluation illuminated the relative strengths and weaknesses of YOLOv8n and YOLOv8x, leading to the conclusion that YOLOv8n is well-suited for real-time ITS applications, while YOLOv8x exhibits superior detection capabilities.
Exploring smart drug delivery platforms through the adsorption of chlormethine anticancer by an iron-enhanced metallofullerene
(Elsevier, 2024) Saadh, M.J.; Dhiaa, S.M.; Hussein, A.H.A.; Karim, M.M.; Idan, A.H.; Mirzaei, M.; Mosaddad, S.A.; Salem-Bekhit, M.M.
Representative iron-enhanced metallofullerenes including FeC24, FeC23, and FeC22 models were assessed for the adsorption of chlormethine (CMT) anticancer towards the development of smart drug delivery platforms. To this aim, density functional theory (DFT) calculations were performed to examine the structural and electronic features of models in the singular and conjugated states. Formations of CMT@FeC24, CMT@FeC23, and CMT@FeC22 conjugated complex systems were achieved by a major role of iron-enhanced region for making successful communications with the CMT substance. Two configurations were found for each conjugated complex system by the CMT relaxation at the metallofullerenes with meaningful results for adsorbing, retaining, and releasing processes of the adsorbed drug. The results of electronic features showed possibility of conducting a sensing function for the metallofullerenes during the adsorption of CMT substance. Consequently, the investigated conjugated complex systems were proposed towards the development of smart drug delivery platforms especially by the formation of CMT@FeC22 system.
A review of valorization of agricultural waste for the synthesis of cellulose membranes: Separation of organic, inorganic, and microbial pollutants
(Elsevier, 2024) Sharma, Madhu; Bains, Aarti; Dhull, Sanju Bala; Ali, Nemat; Rashid, Summya; Elossaily, Gehan M.; Chawla, Prince; Gökşen, Gülden
Agricultural waste presents a significant environmental challenge due to improper disposal and management practices, contributing to soil degradation, biodiversity loss, and pollution of water and air resources. To address these issues, there is a growing emphasis on the valorization of agricultural waste. Cellulose, a major component of agricultural waste, offers promising opportunities for resource utilization due to its unique properties, including biodegradability, biocompatibility, and renewability. Thus, this review explored various types of agricultural waste, their chemical composition, and pretreatment methods for cellulose extraction. It also highlights the significance of rice straw, sugarcane bagasse, and other agricultural residues as cellulose-rich resources. Among the various membrane fabrication techniques, phase inversion is highly effective for creating porous membranes with controlled thickness and uniformity, while electrospinning produces nanofibrous membranes with high surface area and exceptional mechanical properties. The review further explores the separation of pollutants including using cellulose membranes, demonstrating their potential in environmental remediation. Hence, by valorizing agricultural residues into functional materials, this approach addresses the challenge of agricultural waste management and contributes to the development of innovative solutions for pollution control and water treatment.
Evaluating the impact of unmanned aerial vehicles (UAVs) on air quality management in smart cities: A comprehensive analysis of transportation-related pollution
(Elsevier, 2024) Bakırcı, Murat
Urban environments face significant air pollution challenges affecting health and sustainability. Using unmanned aerial vehicles for air quality monitoring offers a promising solution. This research aims to improve these vehicles' ability to identify pollution sources and develop strategies, with a focus on transportation-related pollution. Detailed air pollution tests revealed that pollutant concentrations surged during morning rush hours, especially in high-traffic coastal areas, while areas away from traffic had much lower levels. Evening tests showed that pollutants from daytime traffic had dispersed throughout the urban area. The consistent northward shift in pollutant concentrations underscored the link between traffic patterns and pollutant distribution. Quantitative analyses and the resulting air pollutant maps showed average increases in pollutant concentrations between morning and evening hours in high-traffic areas: 12.1% for NO2, 5.3% for CO, 9.8% for PM10, and 11.4% for PM2.5. In contrast, the increases in pollutant concentrations in less trafficked urban regions were 45.9%, 48.2%, 32.7%, and 29.5%, respectively. This demonstrates how air pollution originating from areas with heavy traffic impacts other regions through environmental and geographical factors. The findings underscore the need for comprehensive air quality management strategies at the city level, targeting emissions in high-traffic areas and adapting to temporal fluctuations in pollutant levels.
Impact of conjugation of whey protein concentrate with different carbohydrates: Monitoring structural and technofunctional variations
(Elsevier, 2024) Dıblan, Sevgin; Salum, Pelin; Ulusal, Fatma; Erbay, Zafer
This study utilized whey protein concentrate (WPC) as the primary protein source, employing the Maillard reaction to link it with three distinct carbohydrates: lactose, maltodextrin, and gum Arabic. Mixtures were prepared with a 1:4 protein-to-carbohydrate ratio, and conjugation was performed using dry heating at a temperature of 60 degrees C, 50% relative humidity for 8 h processing time. Under the same conditions, native WPC was heated as a control group. The formation of conjugates was tracked by monitoring absorbance changes, browning index (BI), and reduction in free amino groups (FAG). All conjugates exhibited significant loss of FAG, correlating with an increase in BI. Shifts in protein fingerprint bands observed via Fourier Transform Infrared Spectroscopy suggested potential protein-carbohydrate interactions, while X-ray diffraction showed increased sample crystallinity post-conjugation. Solubility assessments across pH levels (3.0-8.0) indicated a 10-13% rise in solubility for conjugated samples compared to mixtures, broadening their potential applications. Moreover, the emulsion stability index demonstrated improved stability after conjugation. Overall, the Maillard reaction-mediated conjugation enhanced the solubility and stability of emulsions.
Innovative approach against cancer: Thymoquinone-loaded PHEMA-based magnetic nanoparticles and their effects on MCF-7 breast cancer
(Elsevier, 2024) Yıldırım, Metin; Acet, Ömür; Önal Acet, Burcu; Karakoç, Veyis; Odabaşı, Mehmet
Breast cancer is most common cancer among women in the World. Thymoquinone (TQ) exhibits a wide range of biological activities such as anticancer, antidiabetic, antimicrobial, analgesic, antioxidant, and anti-inflammatory effects. However, its effectiveness in cancer treatment is hindered by its poor bioavailability, attributed to its limited solubility in water. Hence, novel strategies are required to enhance the bioavailability of TQ, which possesses remarkable anticancer characteristics. The aim of this study is to prepare pHEMA-based magnetic nanoparticles carrying TQ (TQ-MNPs) to improve bioavailability, and therapeutic efficacy against breast cancer. For this purpose, TQ-MNPs were synthesized and characterized with Fourier transform infrared spectrophotometer (FTIR), scanning electron microscopy (SEM), dynamic light scattering (DLS), magnetic field using a vibrating sample magnetometer (VSM). The loading capabilities of synthesized magentic nanostructures were evaluated, and release investigations were conducted under experimental conditions that mimic the cellular environment. The findings of the studies indicated that the TQ carrying capacity of MNPs was deemed satisfactory, and the release efficiency was adequate. MNPs and TQ-MNPs showed biocompatibility against HDFa cells. TQ-MNPs showed stronger anti-proliferative activity against MCF-7 breast cancer cells compared to free TQ (p < 0.05). TQ-MNPs induced apoptosis in MCF-7 breast cancer cells.
Cultivating writing skills: the role of ChatGPT as a learning assistant—a case study
(Springer Open, 2024) Punar Özçelik, Nermin; Yangın Ekşi, Gonca
Artificial intelligence (AI) has garnered considerable interest in the field of language education in recent times; however, limited research has focused on the role of AI in the specific context of register knowledge learning during English language writing. This study aims to address this research gap by examining the impact of ChatGPT, an AI-powered chatbot, on the acquisition of register knowledge across various writing tasks. The research design employed a one-case shot pre-experimental design, with 11 voluntary participants selected through convenience sampling. Preliminary results indicate that students found ChatGPT beneficial for acquiring formal register knowledge but perceived it as unnecessary for informal writing. Additionally, the effectiveness of ChatGPT in teaching neutral register was questioned by the participants. This research contributes to the existing literature by shedding new light on the effects of AI-generated chatbots in register learning during the writing process, offering insights into their potential as learning assistants. Further investigation is warranted to explore the broader implications and applications of AI in language learning contexts.
Electromyographic analysis of the traditional and spin throwing techniques for goalball games related to ball velocity for selected upper extremity muscles
(BMC Sports Science, Medicine and Rehabilitation, 2024) Gökçen, Ayşenur; İnce, Gonca; Alcan, Veysel
Goalball is a popular sport among visually impaired individuals, offering many physical and social benefits. Evaluating performance in Goalball, particularly understanding factors influencing ball velocity during throwing techniques, is essential for optimizing training programs and enhancing player performance. However, there is limited research on muscle activation patterns during Goalball throwing movements, needing further investigation to address this gap. Therefore, this study aims to examine muscle activity in sub-elite visually impaired Goalball players during different throwing techniques and visual conditions, focusing on its relationship with ball velocity. Methods: 15 sub-elite Goalball players (2 female, 13 males; mean age of 20.46 ± 2.23 years) participated in the study. Muscle activity was evaluated with the Myo armband, while ball velocity was measured using two cameras and analyzed with MATLAB software. Different visual conditions were simulated using an eye band, and the effects of these conditions on muscle activation and ball velocity were examined. Results: The flexor muscles were found to be more active during the spin throw techniques with the eyes open (p = 0.011). The extensor muscles were found to be more active in the eyes-closed spin throw techniques compared to the eyes-open position (p = 0.031). Ball velocity was found related to the flexor muscles. Interestingly, no significant differences in ball velocity were observed between different throwing techniques or visual conditions (p > 0.05). Conclusions: Ball velocity, one of the performance indicators of the athlete, is primarily related to upper extremity flexor muscle strength rather than visual acuity. It has less visual acuity, but an athlete with more upper-extremity flexor muscle strength will have an advantage in Goalball game. The spin throw technique, which is reported to provide a biomechanical advantage for professional players in the literature, did not provide an advantage in terms of ball velocity for the sub elite players evaluated in our study. This knowledge can inform the development of targeted training programs aimed at improving technique and enhancing ball velocity in Goalball players.
Electrospun nanofiber mats caged the mammalian macrophages on their surfaces and prevented their inflammatory responses independent of the fiber diameter
(Nature Portfolio, 2024) Ayaz, Furkan; Demir, Didem; Bölgen, Nimet
Poly-ε-caprolactone (PCL) has been widely used as biocompatible materials in tissue engineering. They have been used in mammalian cell proliferation to polarization and differentiation. Their modified versions had regulatory activities on mammalian macrophages in vitro. There are also studies suggesting different nanofiber diameters might alter the biological activities of these materials. Based on these cues, we examined the inflammatory activities and adherence properties of mammalian macrophages on electrospun PCL nanofibrous scaffolds formed with PCL having different nanofiber diameters. Our results suggest that macrophages could easily attach and get dispersed on the scaffolds. Macrophages lost their inflammatory cytokine TNF and IL6 production capacity in the presence of LPS when they were incubated on nanofibers. These effects were independent of the mean fiber diameters. Overall, the scaffolds have potential to be used as biocompatible materials to suppress excessive inflammatory reactions during tissue and organ transplantation by caging and suppressing the inflammatory cells.
Exploration of Calocybe indica mushroom phenolic acid-kidney bean protein complex: Functional properties, amino acid profiles, in-vitro digestibility, and application in vegan product development
(Elsevier, 2024) Patil, Nikhil Dnyaneshwar; Thakur, Sweezee; Bains, Aarti; Kaur, Sawinder; Ali, Nemat; Arora, Rahul; Parvez, Mohammad Khalid; Gökşen, Gülden; Janghu, Sandeep; Chawla, Prince
The study evaluates the interaction between Calocybe indica mushroom polyphenols (phenolic acid) and kidney bean protein (KBPM), aiming to enhance vegan food quality. The mushrooms exhibited a carbohydrate content of 3.65%, an antioxidant activity of 55.04 ± 0.17%, and a phenolic content of 4.86 mg GAE/g. Caffeic and cinnamic acids were identified through high-pressure liquid chromatography. Various concentrations of KBPM were tested at phenolic acid concentrations of 0.025, 0.050, 0.1, 0.2, 0.4, 0.8, and 1%, among these, KBPM 0.2 demonstrated the highest binding efficiency of 99.40 ± 0.05%. Notably, this complex improved the protein's functional properties, such as solubility by 11.43%, water and oil holding capacities by 10.62% and 22.04%, and emulsion capacity and stability by 3.69% and 5.83%, respectively, compared to the native protein. The protein-phenolic acid complex also enhanced thermal stability, surface charge, amino acid content, and reduced particle size compared to native protein. These enhancements also improved protein digestibility and sensory attributes in a fruit-based smoothie.
Effect of process parameters on the rheological properties of banana (Musa acuminata) fiber and optimization using response surface methodology
(Elsevier, 2024) Pandey, Shubham; Naik R.K.; Pandey, Vinay Kumar; Srivastava, Shivangi; Pandey, Shivam; Rustagi, Sarvesh; Gökşen, Gülden
The labor-intensive, time-consuming, and uneconomical nature of manually extracting banana (Musa acuminata) fibers from pseudo-stem sheaths has prompted the exploration of automation as a solution. This study focuses on automating the feeding process of banana pseudostem sheaths using a quick return mechanism, which is more effective than other approaches. A comprehensive study was conducted to assess the impact of key process parameters, namely the decorticator (480–540 rpm), roller speed (50–80 rpm), and clearance between rollers (2–4 mm), on the mechanical properties of the extracted banana fiber. The Response Surface Methodology (RSM) was employed for the experimental design and analysis of data, and the mechanical properties under investigation included the tensile strength, Young's modulus, and strain percentage of the banana fiber. The results revealed that the decorticator speed, roller speed, and clearance between rollers are significantly influenced by their mechanical properties. Herein, the optimal process parameter values are identified as follows: a decorticator speed of 510 rpm, roller speed of 65 rpm, and clearance of 3 mm between rollers. The mechanical characterization of the optimized banana fiber exhibited impressive properties, with an ultimate tensile strength of 679.48 MPa, Young's modulus of 25.47 GPa, and strain of 3 %. This study demonstrates that automation coupled with systematic parameter optimization can enhance the mechanical attributes of banana fibers. This research not only addresses the challenges of manual extraction, but also advances the understanding of how process parameters affect banana fiber quality, thereby facilitating the utilization of this natural fiber in various industrial applications.
Stigma and depression among obese infertile women: a cross-sectional study
(Springer Link, 2024) Koç, Özlem; Karakoç, Hediye; Ersöğütçü, Filiz
Obesity causes infertility through various pathways, including disruption of ovarian follicular development, qualitative and quantitative development of the oocyte, fertilization, embryo development, and implantation. In traditional societies such as Türkiye, having children is a determinant of social status. Stigma is defined as a negative sense of social difference from others. Depression is a common health problem in infertile women due to the stressful nature of treatment procedures, fear of treatment failure, and the patient’s inability to become pregnant. In this cross-sectional study, the sample consisted of 161 infertile women from an infertility outpatient clinic of a university hospital in Eastern Turkey. Results: It was determined that depression scores had a strong positive correlation with stigma scores. In the multiple regression analysis performed to evaluate the effects of five independent variables determined to have an effect on depression scores, it was seen that the independent variables explained depression levels by 80%. Conclusion: The findings of this study suggest that stigma and depression are significant factors affecting the psychosocial and emotional well-being of obese women experiencing infertility. These results underscore the potential need for more comprehensive psychosocial support and assessment for women experiencing infertility related to obesity. Obese patients should be informed about the importance of pre-pregnancy weight reduction and should be encouraged to lose weight before the treatment to reduce the poor obstetrical outcomes due to obesity. Additionally, evidence-based guidelines should be prepared for assisted reproductive techniques for fertility treatment in obese infertile women.
Antimicrobial activity enhancement of PVA/chitosan films with the additive of CZTS quantum dots
(Springer Link, 2023) Ceylan, Seda; Küçükosman, Rıdvan; Yurt, Fatma; Özel, Derya; Öztürk, İsmail; Demir, Didem; Ocakoğlu, Kasım
The wound environment is a breeding ground for pathogens, and traditional wound dressing materials lack antibacterial properties. In this work, we aimed to develop PVA/chitosan (P/C)-based wound dressing scaffolds with anti-infective properties using Cu2ZnSnS4 quantum dots (CZTS QDs) to prevent infections in the wound. CZTS quantum dots were prepared by a simple hydrothermal process and characterized using appropriate techniques such as TEM, XRD, FTIR spectrum, and UV-Vis absorption spectroscopy. CZTS QDs were subsequently loaded at different concentrations onto PVA/chitosan membranes (0, 1.6, 2.5 and 3.3% w/w, based on the total polymer quantity). The chemical structure, contact angle and mechanical properties of the membranes were analyzed, and their antimicrobial activities and cell viability were also investigated. The cytocompatibility of the membranes and cell morphology was investigated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and SEM. Based on studies on the interactions between membranes and cells, it was determined that incorporation of CZTS QDs into the membrane did not cause toxicity. To the best of our knowledge, this is the first report on loading CZTS QDs into membranes for tissue engineering applications, and the overall findings suggest that CZTS QDs-integrated membranes might have potentially appealing uses as antimicrobial films for wound healing.
Immobilization of Alpha-Amylase onto Ni2+ Attached Carbon Felt: Investigation of Kinetic Parameters from Potato Wastewater
(Wiley, 2023) Acet, Ömür; İnanan, Tülden; Öndül Koç, Eda; Sert, Buse; Önal Acet, Burcu; Odabaşı, Mehmet; Ocakoğlu, Kasım; Dizge, Nadir
α-amylase is an important enzyme for textile, food, paper, and the pharmaceutical industrial areas. In this study, Ni2+ attached carbon felt structures with nitrogen active site (Ni2+-N-ACF) are produced. The surface morphologies of the N-ACF and Ni2+-N-ACF are investigated by means of scanning electron microscopy (SEM) analysis. Ni2+ ions binding on the N-ACFs are determined by energy dispersive X-ray (EDX) analysis and a graphite furnace atomic absorption spectrometer (AAS). The effect of pH, ionic strength, initial α-amylase concentration, and temperature parameters is investigated for α-amylase immobilization on Ni2+-N-ACF structures. In addition, pH and temperature effect on the activities of the free and the immobilized amylase, kinetic parameters, storage, and operational stabilities are made. Lastly, starch degradation in potato waste water is tested on Ni2+-N-ACF. The obtained results show that α-amylase immobilized Ni2+-N-ACF can be used for starch degradation on an industrial scale.
Antibacterial and antioxidant activity of gold and silver nanoparticles in dextran–polyacrylamide copolymers
(Springer Link, 2024) Tkachenko, Anton; Özdemir, Sadin; Tollu, Gülşah; Dizge, Nadir; Ocakoglu, Kasım; Prokopiuk, Volodymyr; Onishchenko, Anatolii; Сhumachenko, Vasyl; Virych, Pavlo; Pavlenko, Vadym; Kutsevol, Nataliya
Search for new antimicrobial agents is of great significance due to the issue of antimicrobial resistance, which nowadays has become more important than many diseases. The aim of this study was to evaluate the toxicity and biological effects of a dextran-graft-polyacrylamide (D-PAA) polymer-nanocarrier with/without silver or gold nanoparticles (AgNPs/D-PAA and AuNPs/D-PAA, respectively) to analyze their potential to replace or supplement conventional antibiotic therapy. The toxicity of nanocomplexes against eukaryotic cells was assessed on primary dermal fibroblasts using scratch, micronucleus and proliferation assays. DPPH (2,2-diphenyl-1-picrylhydrazylradical) assay was used to evaluate the antioxidant capacity of D-PAA, AgNPs/D-PAA and AuNPs/D-PAA. DNA cleavage, antimicrobial and biofilm inhibition effects of nanocomplexes were investigated. Nanocomplexes were found to be of moderate toxicity against fibroblasts with no genotoxicity observed. AgNPs/D-PAA reduced motility and proliferation at lower concentrations compared with the other studied nanomaterials. AgNPs/D-PAA and AuNPs/D-PAA showed radical scavenging capacities in a dose-dependent manner. The antimicrobial activity of AgNPs/D-PAA against various bacteria was found to be much higher compared to D-PAA and AuNPs/D-PAA, especially against E. hirae, E. faecalis and S. aureus, respectively. D-PAA, AgNPs/D-PAA and AuNPs/D-PAA showed DNA-cleaving and biofilm inhibitory activity, while AgNPs/D-PAA displayed the highest anti-biofilm activity. AgNPs/D-PAA and AuNPs/D-PAA were characterized by good antimicrobial activity. According to the findings of the study, AgNPs/D-PAA and AuNPs/D-PAA can be evaluated as alternatives for the preparation of new antimicrobial agents, the fight against biofilms, sterilization and disinfection processes. Our findings confirm the versatility of nanosystems based on dextran-polyacrylamide polymers and indicate that AgNPs/D-PAA and AuNPs/D-PAA can be evaluated as alternatives for the preparation of novel antimicrobial agents.
A New Design to Enhance the Enzyme Activities: Investigation of L-Asparaginase Catalytic Performance by IMAC Effect on g-C3N4 Nanolayers
(Springer Link, 2024) Sert, Buse; Acet, Ömür; Noma, Samir Abbas Ali; Osman, Bilgen; Odabaşı, Mehmet; Ocakoğlu, Kasım
Recently, graphite carbon nitride (g-C3N4) has come to the fore as a new material with its carbon-based two-dimensional structure, simple preparation procedure, and excellent physicochemical stability properties. This study aims to investigate the activity and kinetic studies of the L-asparaginase enzyme via immobilized metal ion affinity chromatography (IMAC) process of g-C3N4 nanolayers. Firstly, g-C3N4 nanolayers were synthetized and Ni2+ ions were binded their surfaces. The synthesized samples were investigated by SEM, ICP-MS, XRD, and FTIR. The highest L-ASNase adsorption on Ni2+-g-C3N4 nanostructures was 444.1 mg/g, at 3 mg/mL L-ASNase concentration. Optimal medium conditions for L-ASNase adsorption occurred at pH 8.0 and 25 °C. The immobilized enzyme showed improved stability relating to the soluble enzyme in extreme situations. On the other hand, the storage stability and reusability of the immobilized enzyme were found to be approximately 64 and 53% of the original activity after 29 days at room temperature and 10 cycles, respectively. From the Michaelis–Menten constants Km and Vmax, both of them decreased after immobilization compare to the free one. The obtained outcomes showed that the g-C3N4 is a suitable matrix for L-asparaginase immobilization with ideal catalytic efficiency and improved stability.

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