Search Results (1,754)

Silver diamine fluoride/potassium iodide (SDF/KI) Riva Star (SDI) is a tooth desensitizing and anti-caries agent that may be indicated for arresting caries before restoring the tooth in selective caries approach. The aim was to determine the effect of SDF/KI pretreatment on the bonding of SDR Plus Bulk-Fill Flowable (Dentsply) with Clearfil SE Bond 2 (Kuraray) and G-Premio Bond (GC) in self-etch mode on sound dentin. A total of 240 dentin samples were prepared and assigned to 12 groups based on SDF/KI pretreatment (with or without), adhesive type, and testing time (1, 3, and 6 months). The shear bond strength (SBS) was measured using an UltraTester. SBS data were analyzed using three-way factorial model (Adhesive × Pretreatment × Time) and Wald (F) tests, with α = 0.05. Fracture modes were analyzed using χ² and Fisher’s exact test, with α = 0.05. Clearfil performed significantly better than G-Premio at all time points (p < 0.001). Riva Star pretreatment significantly reduced SBS for both adhesives at all time points (p < 0.001). SBS reduction was significantly higher for Clearfil (p < 0.001). The effect of storage was not significant (p = 0.388). Fracture mode distribution differed significantly between adhesives (p < 0.001). Pretreatment × fracture interaction was significant for Clearfil (p = 0.0052). Mixed fractures in G-premio were rare. Full article

Superabsorbent polymers (SAPs) are materials that can absorb and retain water solutions with a mass of several hundred times greater than their own. This work aimed to synthesise and evaluate the effects of highly absorbent starch phosphate-g-poly(acrylic acid) copolymers on the microbiological activity of soils previously used for agriculture. The biopolymers studied were obtained by thermal and chemical oxidation of starch phosphates and copolymerized with potassium salts of acrylic acid. Basic physicochemical parameters were determined in the applied soil. Following SAP application, the basal respiration rate was measured at 22 °C with a constant soil moisture content of 60% WHC. The incubation time in constant temperature and moisture conditions was 78 days. After this period, their microbiological activity (microbial and organic phosphorus fractions) was assessed, thereby enabling the determination of the direction of change in the soil environment. The addition of SAP increases the soil’s water-holding capacity and respiration. The SP-g-PAA polymers serve as slow-release sources of potassium and phosphorus ions. These elements were bound to the polymer network by ionic and covalent bonds. Analysis of the results shows that within two weeks, 47–80% of the starch hydrogel undergoes microbial degradation. No differences were found in the content of labile forms of phosphorus in soils with SAP additions compared to soils without polymer additions. The use of modified starch reduces the consumption of vinyl monomers, while the resulting product is characterised by high absorbency and low water content, which reduces the amount of energy needed to obtain the finished product, thus contributing to sustainable development. Full article

Limonium irtaense is an endangered halophyte endemic to coastal Castellón (Spain). This study aimed to support its conservation by assessing the effects of salinity on seed germination and seedling performance, as well as plants’ physiological and biochemical responses to salt stress during early vegetative growth. Seed germination was tested in the presence of 0 to 300 mM NaCl, followed by recovery assays for non-germinated seeds. Seedlings were grown under three salinity levels, by irrigation with water (control), 300 mM NaCl or 600 mM NaCl. Growth parameters, photosynthetic pigments, osmolytes, ion contents, oxidative stress markers and antioxidant compounds were determined in plants derived from the initial germination tests and the recovery of germination assays and subjected to the different salt treatments. Germination was highest in distilled water and declined with increasing salinity; however, salt-inhibited seeds germinated rapidly and efficiently in the recovery assays. Seedlings from salt-primed seeds showed higher survival rates and biomass than those from control germination tests. Salt treatments significantly reduced growth, with plants derived from salt-treated seeds generally showing higher tolerance, probably because of enhanced proline accumulation, more efficient transport and sequestration of toxic ions in leaf vacuoles, and potassium retention. These findings provide insights into L. irtaense adaptation mechanisms and support using salt-priming to improve conservation and translocation efforts for this endangered species. Full article

Homemade explosives (HMEs) are of increasing interest to security forces worldwide due to their widespread utilization by terrorists. Their synthesis is relatively straightforward, requiring only a few readily available chemical compounds. Among the most popular HMEs are organic peroxides, specifically triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD). This manuscript reports on a paper-based sensor developed for the detection of HMTD. The sensor facilitates fast, inexpensive, and simple detection of this peroxide. The developed sensor was compared with well-established commercial and in-house-developed iodometric tests typically used for peroxide determination. The colorimetric principle was based on the use of a potassium iodide and citric acid solution applied to a paper substrate. The HMTD and TATP samples were prepared in an acetone–water mixture (1:1, v/v). The sensor was able to detect HMTD down to a limit of 0.01 mg/mL. The developed sensor does not exhibit cross-reactivity with other explosives, including TATP. Furthermore, an HSV analysis of the photographs was performed using the Trigit application. Full article

Heparan sulfates (HS) are polysaccharides abundantly expressed in the extracellular matrix and the glycocalyx of endothelial cells, having a putative role in vascular function. The role of HS in vascular reactivity remains unclear. Herein, we sought to determine whether HS regulate the vascular tone in physiological conditions. Using male, 6–8-weeks-old, CD1, C57BL/6, syndecan 1 (Sdc1^−/−) and glypican 1 (Gpc1^−/−) knockout mice, we investigated if the degradation of HS with heparinase III altered vascular reactivity to norepinephrine (NE), acetylcholine (ACh) and potassium chloride (KCl). Our findings indicate that HS are crucial players in the vascular response to NE and ACh in CD1, C57BL/6, and Sdc1^−/− but not in Gpc1^−/− mice. Both Sdc1^−/− and Gpc1^−/− showed increased compensatory expression of syndecan 2 and syndecan 4. However, while Sdc1^−/− showed decreased expression of glypican 1, Gpc1^−/− showed increased expression of syndecan 1 in aortic homogenates. The lack of response to the vascular reactivity effects of heparinase III in Gpc1^−/− suggests a differential role of HS to proteoglycan function in the regulation of the vascular tone. Our data demonstrate a physiological role for HS in the regulation of the vascular tone in physiological conditions. Full article

We report on the study of the immobilization process of non-radioactive rhenium (Re), a chemical analogue of technetium-99 (⁹⁹Tc), in compounds based on magnesium potassium phosphate (MKP), as well as the possibility of enhancing their properties with iron-bearing additives/fillers. Powdered Re₂O₇ was used as the initial Re-containing source. Because of the solubility and high leachability of Tc (VII), which is also volatile at high temperatures, its immobilization for long-term storage and disposal poses a serious challenge to researchers. Taking this into account, low-temperature stabilization technology based on MKP, a cementitious material, is currently considered promising. We prepared experimental specimens based on Re-incorporated MKP matrices and analyzed their microstructure in detail using analytical methods of X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Considering that iron-bearing substances can reduce Tc (VII) to the lower-valence form Tc (IV), which is more stable, attention was also paid to evaluate the effect of fillers (Fe₂O₃, Fe₃O₄, Fe, FeS and blast furnace slag (BFS)) on strength, oxidation state, and water resistance (expressed as leaching cumulative concentration). The addition of fillers ensures the formation of denser compounds based on MKP after 28 days of curing under ambient conditions and increases their mechanical strength. The oxidation state of Re and the reduction from Re (VII) to Re (IV) was estimated using X-ray-absorption near-edge structure (XANES) analysis. Considering the Re leaching concentrations from tests using the ANS-16.1 standard in water, enhanced leachability indices (LI) for Re from MKP matrices were determined with the addition of iron-bearing fillers. Overall, the average LI values were greater than the minimum limit, indicating their acceptance for disposal recommended by the U.S. Nuclear Regulatory Commission. Full article

The rhizosphere, a confined area of soil plant roots, is an intersection of microbial activity and root exudates. Known as the rhizosphere effect, it enhances crop yield and sustainability by improving nutrient availability, beneficial compounds, and pathogen control. This study combines a field-based rhizosphere–bulk soil comparison for peanut with a geostatistical approach to quantify the spatial variability of rhizosphere-driven changes in soil quality indicators in the Ghardaïa region (southern Algeria), which is known for its sandy–clay and sandy–loam soils. Samples of rhizosphere and bulk soils were prospected using a systematic plan. Subsequently, the pH, electrical conductivity, calcium carbonate, organic matter, total nitrogen, available phosphorus, total potassium, and soluble sodium were determined for each soil (rhizosphere and bulk soil). To assess the spatial variability of rhizosphere soil parameters, semi-variograms of the fitted models were generated using auto-kriging. The results showed that both types of soils were moderately alkaline, with a reduction of 5.52% in the pH of the rhizosphere compared to the bulk soils. Soils were relatively low in organic matter, with only 3.3% of soils having organic matter levels above 20 g kg⁻¹. However, organic matter contents were consistently higher in the rhizosphere (8.51 ± 4.59 g kg⁻¹) than in the bulk soil (6.78 ± 3.52 g kg⁻¹). In the rhizosphere, an increase of 10% in labile phosphorus was noted. Total nitrogen was increased by 52.57%. T-tests suggested no significant difference in potassium and sodium levels, and they were moderately present in both soils. Significantly positive relationships were noted between available phosphorus and total nitrogen (R = 0.59, p < 0.001). However, negative correlations were revealed between pH and organic matter available phosphorus (R = −0.77, p < 0.001) and pH and total nitrogen (R = −0.56, p < 0.01). These results indicate the effects of rhizosphere interactions on soil property improvements and their implications for sustainable agricultural practices, including crop rotation, intercropping, and green manure applications. Full article

Straw returning has been evidenced to be an effective strategy for straw utilization. Nevertheless, numerous adverse effects on straw direct returning have been widely reported. It is safer to fully degrade the straw and then return it to the soil. This strategy has been shown to significantly improve soil nutrients. However, the effect on rice growth is unclear. In this study, a pot experiment was conducted by using different types of mushroom residues with chemical fertilizer for field return, compared to the conventional method of applying chemical fertilizer alone, and straw return with or without fertilizer. It was found that the return of mushroom residues to the field could increases the soil organic matter content by 16.9–23.5%, the alkaline nitrogen by 39.1–47.4%, and the available potassium by 6.8–10.8%. Furthermore, mushroom residues were found to reduce the population of fungi and bacteria in the soil to a certain extent and increase the number of actinomycetes. Moreover, it was determined that mushroom residues elevated the nutrient content in plants, accelerated the tillering rate, and increased the number of tillers. This ultimately led to an increase in rice yield components, such as thousand-grain weight and the effective number of spikes. Mushroom residues can mimic the benefits of straw return while minimizing potential harm to rice yields. This study provides an effective strategy for the resource utilization of straw. Full article

This study introduces an innovative sensor architecture predicated on surface plasmon polaritons (SPPs), comprising a metal–insulator–metal (MIM) waveguide in conjunction with a cat-faced circular split resonator (TCRSW). The efficacy of the proposed nanosensor was meticulously evaluated utilizing the finite element method (FEM). It was determined that the TCRSW configuration significantly impacts the sensor’s performance. By means of a comprehensive optimization of the structural parameters, the sensor attained an apex sensitivity of 3380 nm/RIU and a figure of merit (FOM) of 56.33 in its optimal configuration. Furthermore, the study comprehensively evaluated the sensor’s applicability for temperature sensing, demonstrating a measured temperature sensitivity of 1.673 nm/°C. Meanwhile, the application of the proposed structure in biosensing was comprehensively evaluated. When employed as a concentration sensor for detecting sodium and potassium ion solutions, the maximum achievable sensitivities reached 0.49 mg·d/L and 0.6375 mg·d/L, respectively, which highlights its significant potential not only for high-precision temperature monitoring but also for sensitive and reliable biosensing applications. Additionally, the proposed nanosensor holds considerable promise for applications in other nanophotonic fields. Full article

The increasing atmospheric concentration of carbon dioxide (CO₂) poses a critical threat to global climate stability, highlighting the need for efficient carbon capture technologies. While amine-based solvents such as monoethanolamine (MEA) are widely used for industrial CO₂ capture, they are subject to limitations such as high energy requirements for regeneration, solvent degradation, and environmental concerns. This study investigates potassium carbonate/bicarbonate system as an alternative solution for CO₂ absorption. The absorption mechanism and reaction kinetics of potassium carbonate in the presence of bicarbonates were reviewed. A rate-based model was developed in Aspen Plus, using literature kinetics, to simulate CO₂ absorption using 20 wt% potassium carbonate (K₂CO₃) solution with 10% carbonate-to-bicarbonate conversion under different industrial conditions. Three flue gas compositions were evaluated: cement industry, biomass combustion, and anaerobic digestion, each at 3000 m³/h flow rate. The simulation was conducted to determine minimum column height and solvent loading requirements with a target output of 90% CO₂ removal from the gas streams. Results demonstrated that potassium carbonate systems successfully achieved the target removal efficiency across all scenarios. Column heights ranged from 18 to 25 m, with molar K₂CO₃/CO₂ ratios between 1.41 and 4.00. The biomass combustion scenario proved most favorable due to lower CO₂ concentration and effective heat integration. While requiring higher column heights (18–25 m) compared to MEA systems (6–12 m) and greater solvent mass flow rates, potassium carbonate demonstrated technical feasibility for CO₂ capture. The findings of this study provide a foundation for technoeconomic evaluation of potassium carbonate systems versus amine-based technologies for industrial carbon capture applications. Full article

Potassium (K) fertilization plays a key role in regulating stem morphology, particularly stem diameter, yet the influence of different K fertilizer formulations on stem structure and tensile strength remains insufficiently understood. Cereal straw is a key lignocellulosic by-product with growing importance in the circular bioeconomy. Thus, the aim of this study was to determine the links between potassium nutrition, stem structure, and mechanical behavior for four cereal species: wheat, barley, rye, and oats. There were three potassium fertilization levels (0, 60, and 120 kg K ha⁻¹) conducted in a field experiment in eastern Croatia (2021/2022). At maturity, stem morphology, macroelements (Ca, K, P, C, N), acid detergent fiber (ADF), neutral detergent fiber (NDF), and uniaxial tensile properties (maximum force, tensile strength, Young’s modulus) were determined. Cereal species was the dominant source of variation (p < 0.0001) for all traits, whereas the main effect of K was generally weak and significant only for stem diameter at the midpoint and N concentration, although K × species interactions were frequent. Oats and rye showed the most vigorous biomass production, whereas wheat exhibited by far the highest tensile strength (about 120 MPa) and stiffness (6.23 GPa), together with the highest ADF, while barley had the greatest NDF. Oat stems had the lowest ADF and NDF, indicating less lignified, more digestible tissues but mechanically weaker straw. Mechanical traits were tightly and positively correlated with ADF, NDF, and CN ratio, whereas P showed weak or negative associations with plant size and strength. Therefore, for targeted straw valorization, cereal species selection is paramount, with potassium fertilization playing a secondary, species-dependent role. Full article

This study includes a comparative analysis of four graphene-based electrochemical sensors used for the detection of melatonin, an endogenous hormone involved in circadian rhythm regulation and associated with various neurological pathologies. The sensors were based on screen-printed electrodes (SPE) modified with graphene (G), graphene modified with gold nanoparticles (AuNPs/G), graphene oxide (GO), and reduced graphene oxide (rGO). Melatonin was extracted from commercially available pharmaceutical products, purified, and characterized using UV-Vis spectroscopy, FTIR spectrometry, and HPLC. The performance of the electrodes was evaluated via cyclic voltammetry, using potassium ferrocyanide and standard melatonin solutions to determine the kinetic characteristics, while square-wave voltammetry was employed to determine the detection and quantification limits. G/SPE showed the best performance, with a detection limit of 0.3424 μM, followed by AuNPs/G/SPE with an LOD of 1.2768 μM. GO/SPE had the poorest performance (LOD 23.1056 μM), and rGO/SPE had an LOD of 5.8503 μM. Testing of sensors on pharmaceuticals showed accurate quantification of melatonin in a complex environment. The results highlight the potential of G/SPE and AuNPs/G/SPE sensors for use in the rapid and accurate detection of melatonin in pharmaceutical and biomedical applications. Full article

Background/Objectives: Ash made from juniper trees and added to cornmeal-based dishes may have provided calcium (Ca) to traditional Indigenous diets. Few studies have quantified the mineral content of juniper ash, including its Ca content. The objective of this study was to determine whether juniper ash could serve as a safe source of non-dairy Ca in an intervention study. Methods: Branches from two varieties of Juniper (Rocky Mountain Juniper, or Juniperus scopulorum and Eastern Red Cedar, or Juniperus virginiana) were harvested and burned to ash in a laboratory setting. Juniper ash from the southwestern U.S. available for retail purchase was used for comparison. All samples were tested for content of 10 nutritive elements (Ca, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, selenium, and zinc) and 20 potentially toxic elements (silver, aluminum, arsenic, barium, beryllium, cadmium, cobalt, chromium, mercury, lithium, molybdenum, nickel, lead, antimony, tin, strontium, thallium, uranium, and vanadium) as well as n = 576 pesticide residues. Results: All samples contained both nutritive and potentially toxic elements. Each teaspoon of ash contained an average of 445 ± 141 mg Ca. However, the samples also contained lead in amounts ranging from 1.09 ppm to 15 ppm. Conclusions: Information on the nutritive and potentially toxic elemental content of juniper ash and how it may interact within a food matrix is insufficient to determine its safety as a Ca source. Further investigation is needed on the bioavailability of calcium oxide and its interaction with other dietary components to clarify the potential role of juniper ash in contemporary food patterns. Full article

Background/Objectives: Blood renin and electrolyte levels are associated with blood pressure and hypertension. While sex-specific effects of such factors have been investigated, exact comparisons of the factors between the sexes have been scarce. Methods: Using cohort data from the Korean Genome and Environmental Study (KoGES), the study population that did not receive any interventions for blood pressure was determined. Blood levels of renin and electrolytes, including sodium, potassium, chloride, and calcium, were used to test their relationship with hypertension and blood pressure. Confounding variables, including age, body mass index (BMI), waist-to-hip ratio, family history of hypertension, alcohol consumption, smoking, blood urea nitrogen, creatinine, protein, and albumin levels, were used for adjustment in the multiple regression analysis. Results: In the single-variable analysis, sodium levels were significantly higher in the female population, and showed strong associations in the multiple regression analysis. Blood potassium levels showed no significant sex-specific differences. Among these factors, renin showed the greatest significance in both the total population and sex-specific groups. Moreover, in the development of hypertension, the effect size of renin was significantly different between sexes. Additionally, BMI tended to show stronger associations in females. Conclusions: This study identified sex-specific differential effects of renin and other electrolytes that are important in the pathophysiology of blood pressure. These findings provide clues for the more precise management of hypertension. Full article

Rechargeable lithium-, sodium-, and potassium-ion batteries are utilized as essential energy storage devices for portable electronics, electric vehicles, and large-scale energy storage systems. In these systems, anode materials play a vital role in determining energy density, cycling stability, and safety of various batteries. However, the complex electrochemical reactions and dynamic changes that occur in anode materials during charge–discharge cycles generate major challenges for performance optimization and understanding failure mechanisms. In situ characterization techniques, capable of real-time tracking of microstructures, composition, and interface dynamics under operating conditions, provide critical insights that bridge macroscopic performance and microscopic mechanisms of anodes. This review systematically summarizes the applications of such techniques in studying anodes for lithium-, sodium-, and potassium-ion batteries, with a focus on their contributions across different anode types. It also indicates current challenges and future directions of these techniques, aiming to offer valuable references for relevant applications and the design of high-performance anodes. Full article