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Liquorilactobacillus hordei SK6 and Liquorilactobacillus mali SK26 from Traditional Water Kefir Produce Dextrans with Technological Roles
No full textThe significance of exopolysaccharides (EPS) in various applications has garnered increasing attention. In this study, two bacteria, Liquorilactobacillus hordei SK6 and Liquorilactobacillus mali SK26, isolated from traditional water kefir grains, produced 8.89 g/L and 7.2 g/L of homopolymeric glucan, respectively. NMR analysis revealed that both glucans were dextrans composed of (1 → 6)-linked α-d-glucose units, with (1 → 3)-linked α-d-glucose units serving as branching points, accounting for 5.3 ± 0.2% in dextran SK6 and 2.7 ± 0.15% in SK26. FTIR and XRD analyses further confirmed the amorphous nature of the dextrans, although dextran SK6 exhibited micro-arranged structures. Thermal characterization using TGA and DSC showed degradation temperatures of 298.5 °C for dextran SK6 and 282.1 °C for dextran SK26. Clear differences in morphological properties were observed using AFM and SEM. These findings provide valuable insights into dextran-producing strains and their potential applications in various industries. Graphical abstract: (Figure presented.
Determination of copper at trace levels in fennel tea samples by flame atomic absorption spectrometry after the implementation of simultaneous complexation and supramolecular solvent based spraying assisted liquid phase microextraction
No full textA simple and efficient preconcentration method named as supramolecular solvent based spraying assisted liquid phase microextraction (SUPRAS-SA-LPME) was combined with a flame atomic absorption spectrometry (FAAS) for the determination of copper in fennel tea samples at trace levels. An alkanol (1-decanol)/THF based SUPRAS (containing complexation agent) was used as extraction solvent instead of traditional organic solvents for the first time in an SA-LPME process. Under the optimum conditions, system analytical performance of the developed method was evaluated, and limit of detection (LOD)/limit of quantitation (LOQ) values were recorded as 1.91/6.37 µg kg–1. After the evaluation of system analytical performances, the enhancement in detection power/calibration sensitivity was found to be 21.3/21.8 folds when the comparison of LOD values/calibration plot slopes of the FAAS and SUPRAS-SA-LPME-FAAS systems. The method applicability was tested for the fennel tea samples by spiking experiments, and acceptable recovery results (80.2 % – 111.8 %) were obtained for low, mid and high spiked concentration levels
BiFeO3-BaTiO3 sisteminde Zr katkılamanın elektriksel özelliklere etkisinin incelenmesi
No full textSon yıllarda çevresel düzenlemeler nedeniyle kurşun bazlı piezoelektrikmalzemelerin yerine alternatifler geliştirilmesi önem kazanmıştır. Bu kapsamda,bizmut bazlı perovskit yapılı malzemeler dikkat çekmektedir. BiFeO3-BaTiO3 (BF-BT) sisteminin özellikle morfotropik faz sınırında iyi piezoelektrik özelliklergösterdiği tespit edilmiştir.Çalışmada, BF-BT seramikleri katı hal tepkime yöntemiyle sentezlenmiş ve farklıoranlarda Zr katkısının kristal yapı, ferroelektrik ve dielektrik özellikler üzerindekietkileri incelenmiştir. XRD analizleri, Zr katkısının kristal yapıyı bozmadığını ve fazsaflığını koruduğunu göstermiştir. %0,4 Zr katkılı seramikler, daha yüksek kalıntıpolarizasyon ve kristallenme derecesi sergilemiştir. Ayrıca, gerinim-elektrik alanölçümleri, Zr katkısının elektromekanik performansı artırdığını ortaya koymuştur.Dielektrik analizlerde, 300°C civarında faz geçişi gözlemlenmiş ve frekansa bağlıdeğişimler belirlenmiştir.In recent years, due to environmental regulations, the development of alternatives tolead-based piezoelectric materials has gained importance. In this context, bismuth-based perovskite materials have attracted attention. The BiFeO3-BaTiO3 (BF-BT)system has been found to exhibit good piezoelectric properties, especially at themorphotropic phase boundary.In this study, BF-BT ceramics were synthesized using the solid-state method, andthe effects of different Zr doping ratios on the crystal structure, ferroelectric, anddielectric properties were investigated. XRD analyses showed that Zr doping did notdisrupt the crystal structure and maintained phase purity. Ceramics with 0.4% Zrdoping exhibited higher remnant polarization and crystallization degree.Additionally, strain-electric field measurements revealed that Zr doping enhancedelectromechanical performance. Dielectric analyses showed a phase transitionaround 300°C, with frequency-dependent variations observed.</p
Design and Production of Biofunctional PVA/PLA Double-Layered Fiber Wound Dressing by Electrospinning Method
No full textIn this study, a double-layered wound dressing combined with biofunctional components was produced, and characterization studies were conducted. To produce fiber wound dressing, polylactic acid (PLA) and polyvinyl alcohol (PVA) were used in the layers, and the electrospinning method was preferred. Propolis extract and aloe vera gel were preferred as biofunctional components and combined according to the degradability of the polymers and the intended use. The obtained wound dressing samples were subjected to antibacterial analyses, scanning electron microscopy (SEM), Fourier Transform-Infrared Spectroscopy (FT-IR) to analyze bond structures and detect the presence of added components, X-ray diffraction (XRD) to analyze the crystallinity of the components, swelling tests, tensile tests to evaluate the mechanical strength of each layer of the wound Dressing, and finally differential scanning calorimetry (DSC) characterization studies to observe the thermal changes with temperature. In this study, the bilayer fiber was found to be effective against S. aureus. The average fiber diameter was measured as 0.36 ± 0.32 μm, with strong peaks observed at 19.52, 19.90, and 37.83 nm. The bilayer fiber reached 198% saturation at the 5th hour, and its tensile strain was determined as 98.85% ± 22.45%. As a result of the results obtained, this study not only demonstrates the suitability of using the double-layered fiber structure as a wound dressing but also sets an example for future studies on how different polymers and various biofunctional compounds and extracts found in nature can be combined into composite structures, thus producing structures with more desired properties
Advances in Drug Targeting, Drug Delivery, and Nanotechnology Applications: Therapeutic Significance in Cancer Treatment
No full textIn the 21st century, thanks to advances in biotechnology and developing pharmaceutical technology, significant progress is being made in effective drug design. Drug targeting aims to ensure that the drug acts only in the pathological area; it is defined as the ability to accumulate selectively and quantitatively in the target tissue or organ, regardless of the chemical structure of the active drug substance and the method of administration. With drug targeting, conventional, biotechnological and gene-derived drugs target the body’s organs, tissues, and cells that can be selectively transported to specific regions. These systems serve as drug carriers and regulate the timing of release. Despite having many advantageous features, these systems have limitations in thoroughly treating complex diseases such as cancer. Therefore, combining these systems with nanoparticle technologies is imperative to treat cancer at both local and systemic levels effectively. The nanocarrier-based drug delivery method involves encapsulating target-specific drug molecules into polymeric or vesicular systems. Various drug delivery systems (DDS) were investigated and discussed in this review article. The first part discussed active and passive delivery systems, hydrogels, thermoplastics, microdevices and transdermal-based drug delivery systems. The second part discussed drug carrier systems in nanobiotechnology (carbon nanotubes, nanoparticles, coated, pegylated, solid lipid nanoparticles and smart polymeric nanogels). In the third part, drug targeting advantages were discussed, and finally, market research of commercial drugs used in cancer nanotechnological approaches was included
A New Monohydrogen Phosphate-Selective Carbon Composite Membrane Electrode for Soil Water Samples
No full textThis study focused on developing a novel composite phosphate-selective electrode for on-site and real-time applications using a silver polyglutaraldehyde phosphate and carbon nanotube (CNT) matrix. CNT-silver polyglutaraldehyde phosphate compound was synthesized and characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The potentiometric performance of the composite phosphate-selective electrode was then investigated. The results demonstrated that the composite phosphate-selective electrode exhibited good sensitivity, with a linear response in the concentration range of 1.0 × 10−4 to 1.0 × 10−2 M for phosphate ions. The electrode also showed high selectivity towards phosphate ions compared to other anions, such as chloride and nitrate. Additionally, the electrode displayed a quick response time of less than 15 s, making it suitable for real-time measurements. The electrode was applied to surface and soil water samples. The results obtained from the water samples showed a strong correlation with those obtained from the preferred spectrophotometry method, highlighting the potential of the developed electrode for on-site and continuous monitoring of phosphate and offering an efficient and practical solution for various fields that require phosphate detection
Unveiling the Electrocatalytic Activity of Bifunctional Iron-Niobium Double Perovskites for Overall Water Splitting: A-Site Cation Influence
No full textCapitalizing on the electrochemical conversion of water into hydrogen stands as a pivotal strategy in the global transition toward sustainable energy sources. This study investigates the influence of the A-site cation type within A2FeNbO6 double perovskites (where A = Ca, Sr, or Ba) on their bifunctional electrocatalytic activities. The electrocatalytic performance is scrutinized in relation to charge transfer resistance, oxygen vacancy concentration, and metal-oxygen covalency. Among the variants, Sr2FeNbO6 is distinguished as the optimal catalyst, achieving a current density of 10 mA cm⁻2 at overpotentials of 260 mV for the oxygen evolution reaction (OER) and 176 mV for the hydrogen evolution reaction (HER), thus matching the performance of leading metal oxide electrocatalysts. The study reveals pH-dependent kinetics for Sr2FeNbO6, indicative of a lattice oxygen evolution mechanism for OER. An electrolyzer employing Sr2FeNbO6 electrodes for both the anode and cathode delivers a current density of 10 mA cm⁻2 at an efficient cell voltage of 1.76 V for complete alkaline water splitting, while also demonstrating exceptional stability. These insights advance the understanding of material optimization for electrocatalysis and position Sr2FeNbO6 as a viable catalyst for the sustainable production of hydrogen
Q-Wall, a Novel Quartz-Cherenkov Calorimeter Concept
No full textFuture collider experiments and the upgrade of the existing large-scale experiments impose unprecedented radiation conditions for the calorimeter systems, particularly in the forward region. The calorimeters envisaged for these operating conditions must be sufficiently radiation-hard and robust in order to perform as expected for the entire lifetime of the experiments. In this context, a novel calorimeter design utilizing quartz-Cherenkov calorimetry, termed Q-Wall has been developed. The Q-Wall concept is a sampling calorimeter that alternates between plates of absorber (Fe, Pb, W, etc.) and active planes. The active planes comprise compact arrays of PMTs with either very thick quartz windows or fused silica pads optically coupled to traditional PMT windows. In these active elements, charged particles with β > 0.685 produce Cherenkov radiation which impinges directly onto the photocathode of the PMT. The Q-Wall concept holds the promise of a very fast and highly granular tracking calorimeter suitable for high radiation environments. A prototype module of Q-Wall was constructed and tested at CERN test beam. The prototype consisted of three photodetector setups: multianode PMTs directly coupled to ultraviolet-transmitting (UVT) plexiglass in a 2 x 2 and 3 x 3 configuration, an 8 x 8 array of SiPMs coupled to a 5 x 5 array of borosilicate glass cubes, and a 3 x 3 array of SiPMs connected to a 3 x 3 array of borosilicate glass cubes. Here we report on the results of these tests and compare them with electromagnetic shower development simulations with Geant4
A quick and effective approach for removing Ni(II) from paper mill wastewater with magnesium ferrite nanoadsorbent: method development, reusability, isotherm models, and adsorption kinetics
No full textThe removal of Ni2+ ions from the effluent of the paper mill was accomplished by using magnesium ferrite nanoparticles. The nanoparticles were produced through a sol–gel process at low temperatures. Experimental factors were meticulously optimized to enhance the adsorption process. Optimal conditions were determined to be 1.0 mL of buffer solution with a pH of 8.0, 100 mg of nano-sorbent, and mixing for 30 min. When these conditions were put to test, the removal efficiency was enhanced to ≥ 98.4%. Additionally, it was discovered that the nanoparticles exhibit exceptional reusability upon regeneration after the first use. The investigation of adsorption equilibrium was conducted utilizing the Langmuir, Freundlich, and Sips models. The Sips isotherm demonstrated the strongest correlation with the experimental results, as indicated by the coefficient of determination (R2) of 0.9976 while the reaction order was estimated as 1.61 by the kinetic model
