Calcium Concentration Research Articles

Prediction and investigation of water repeated absorption and release properties of superabsorbent polymers during the dry-wet cycles in different solutions

Superabsorbent polymers (SAP) with a three-dimensional cross-linked network structure are used in the concrete field due to their good water absorption and water retention properties. The changes of its repeated water absorption and release properties have an important impact on crack healing, but there is still a lack of relevant research. This study mainly uses the tea-bag method to explore the repeated water absorption and release behavior of sodium polyacrylate and polyacrylic acid-acrylamide copolymers in deionized water, cement filtrate, and saturated calcium hydroxide solution. The quantitative analysis of the change in the peak area of the water-absorbing functional group was performed by fourier transform infrared spectroscopy. The morphology and elements of SAP under different dry-wet cycles were analyzed by scanning electron microscope-energy spectrum analysis. The repeated swelling behavior of SAP was predicted using the classical models. The results showed that the repeated water absorption performance of SAP gradually decreased with the increase of the number of wet-dry cycles. The slope of the curve for the second-order equation gradually increases, and the peak area corresponding to the carboxyl functional group also gradually increases. And the rate and amount of water release gradually increase. For sodium polyacrylate, with the increase in the number of wet-dry- cycles, the increase in the content of calcium, magnesium, and aluminum elements is accompanied by a significant decrease in the content of sodium elements. In contrast, the calcium content on the surface of polyacrylic acid-acrylamide copolymer increased, but the sodium content only slightly decreased.

359 Optimization of calcium inclusion levels in diets fed to growing and finishing beef cattle

Abstract Calcium (Ca) is a mineral that has an essential role in many biochemical pathways and functions of beef cattle. Limestone is the primary supplemental source of Ca in diets fed to growing and finishing cattle in the United States. Preliminary data indicated that inclusion of dietary Ca above the NASEM (2016) requirements as well as mean and modal concentrations reported by the most recent survey of consulting nutritionists may improve average daily gain (ADG) and feed efficiency (gain to feed ration; G:F) of finishing beef cattle. Thus, the objective of this experiment was to determine the optimal concentration of Ca in growing and finishing diets when limestone was the supplemental source of added Ca. A database was constructed containing 89 treatment means from 23 experiments published from 1963 to 2024 where dietary Ca inclusion via limestone represented treatments. Search parameters to construct the database included a combination of Ca, limestone, performance, efficiency, ADG, G:F, feedlot cattle, finishing cattle, growing cattle, and backgrounding cattle. Data were analyzed in JMP Pro 17 using a mixed model to determine linear and quadratic relationships between dietary Ca and ADG, DMI, or G:F with citation as a random effect. An economic sensitivity analysis was conducted to determine variables most influential to the dietary Ca concentration projected to minimize cost of gain using the above models. Concentration of dietary calcium was selected as the explanatory variable for the models rather than limestone because a greater proportion of variation was accounted for in the response variables prior to the citation adjustment (Ca R2 0.05 to 0.25; limestone R2 0.06 to 0.21). Diet Ca concentration and DMI were unrelated (P ≥ 0.75), but diet Ca was related to both ADG (R2 = 0.84; RMSE = 0.36; P ≤ 0.03) and G:F (R2 = 0.74; RMSE = 0.01; P < 0.01) in a quadratic fashion. Maximum ADG occurred when Ca was included at 1.20% of diet DM; approximately 2.6-fold greater than Ca requirements estimated by NASEM (2016). Cost of gain was minimized when Ca was 1.35% of diet DM. Sensitivity analysis revealed Ca concentration to minimize cost of gain was sensitive to changes in DMI, ADG, days on feed, ration cost and cost of yardage. These results provide further evidence that it may be beneficial to feed a greater amount of Ca than currently recommended by the NASEM (2016) for growing and finishing cattle. Future pen-scale feeding trials are warranted to validate the results of this meta-analysis and to determine the dose response of cattle fed graded levels of Ca. Future research should also be conducted to determine the mechanism of action responsible for the observed improvements in animal performance and efficiency resulting from feeding an increased amount of dietary Ca.

Education and cooking methods in the management of calcium and PTH serum levels in patients on hemodialysis: a randomized controlled study.

Chronic kidney disease associated mineral bone disorder (CKD-MBD) is one of the major causes of excess morbidity and mortality in hemodialysis patients. The purpose of this study was to investigate whether education about dietary intakes and specific food processing methods affect serum calcium and PTH concentrations in hemodialysis patients. Forty-seven hemodialysis patients were randomly divided into a control and an intervention group. All participants were on individualized phosphate binder therapy. Both groups received education on dietary intake by a trained dietitian. The intervention group received additional education on specific preparation methods of different foodstuffs and consumed two hospital meals prepared according to these methods during hemodialysis. Serum calcium and PTH levels, and vitamin D analog therapy dosage were periodicallymonitored during the 1-year study period. At the baseline of the study, there were no differences between control and intervention groups in serum calcium (p = 0.078), serum PTH (p = 0.670), and vitamin D analog therapy dosage (p = 0.184). At the end of the study, serum calcium was better regulated in the intervention group, resulting in a significant differencebetween thestudy groups (p = 0.013). This was also confirmed by serum PTH levels in the intervention group, which remained stable until the end of the study (p = 0.110). Additional education on specific food processing techniques mayresult in improved management of serum calcium and PTH levels, which could ultimately provide better control of secondary hyperparathyroidism in hemodialysis patients.

Crop rotation diversity and tillage effects on soil and wheat grain nutrient concentration in an organically-managed system

Consumer demand for high quality organic produce in Canada has in recent years contributed to the development of a more sustainable organic agriculture system that increased productivity without decreasing soil fertility. The objective of this 4-yr field study was to determine if an organic system with diversified crop rotations under reduced tillage would produce high quality spring wheat (Triticum aestivum L.) grain and improve soil fertility. A simplified rotation (SR) consisting of a forage pea (Pisum sativum L.) green manure (GM)-spring wheat sequence and a diversified rotation (DR, forage pea GM-oilseed-pulse crop-spring wheat sequence) were compared under two tillage intensities (high tillage [HT] and low tillage [LT]). The oilseed alternated between mustard (Sinapis alba L.) and flax (Linum usitatissimum L.), and the pulse alternated between field pea and lentil (Lens culinaris L.). Generally, nutrient concentrations in wheat grain were mostly significantly higher under LT than HT and in the DR compared with the SR. In addition, tillage-rotation system influenced soil zinc, calcium, magnesium, and sodium concentrations. However, grain Cd concentration was higher in the LT treatment under the DR sequence relative to other treatments. Our results indicate that organically managed diversified crop rotations under reduced tillage can produce wheat grains with high nutritional value for humans and livestock but may not increase soil micronutrient concentrations.

Mechanical investigation of a Tandem embolization-visualization system for minimally invasive procedures

Transcatheter arterial embolization is a minimally invasive intervention process in which the blood supply to a tumor or an abnormal area of tissue is blocked. One of the most commonly used embolic agents in clinics is microsphere (MS). In order to understand the flow behavior of microspheres in arteries, it is essential to study their mechanical properties systematically. In this work, calcium-alginate MSs with varying calcium concentrations were synthesized using a coaxial airflow method. Indocyanine green (ICG) was added as a fluorescent dye. The effect of ICG concentration change on microspheres was investigated by studying morphology, imageability, rheology, and swelling behavior. Then the effect of calcium chloride concentration change on microspheres was studied by conducting rheological tests, atomic force microscopy tests, hemolysis assay, and thrombogenicity assay. Results showed that microspheres with higher ICG concentrations have longer lasting fluorescence and lower storage modulus (G′). Higher concentrations of calcium chloride led to higher G′, while the local Young's modulus obtained by AFM test was not significantly affected. The MSs with and without ICG showed good hemocompatibility and thrombogenicity.

Effect of fortified calcium compounds from oyster shell on the quality of tapioca pearls

This study aimed to determine the effect of calcium fortification from dried oyster shells (DOS) and calcined oyster shells (COS) at concentrations of 2, 4 and 6 %(w/w) on physical and chemical properties of tapioca pearls. The results showed that the optimal cooking time of TP-COS decreased compared to TP-DOS and TP (control). The TP-DOS and TP-COS exhibited a remaining calcium content ranging from 8.39 to 41.03 mg/g. During seven days of refrigerated storage, TP-COS showed delayed hardness along with decreases in both the enthalpy of gelatinization and retrogradation. The functional groups observed in TP-DOS and TP-COS showed varying intensities compared to TP. Morphology images depicted the distribution of DOS and COS within tapioca pearls, revealing that TP-DOS and TP-COS possessed a denser and more compact structure. The results suggest that COS fortification could improve the nutritional value and delay the change in the texture of tapioca pearls after storage.

Blood Coagulation Activities and Influence on DNA Condition of Alginate-Calcium Composites Prepared by Freeze-Drying Technique.

The aim of this research was to synthesize and characterize alginate-calcium composites using a freeze-drying method, with a focus on their potential applications in biomedicine. This study specifically explored the biochemical properties of these composites, emphasizing their role in blood coagulation and their capacity to interact with DNA. Additionally, the research aimed to assess how the cross-linking process influences the structural and chemical characteristics of the composites. Detailed analyses, including microscopic examination, surface area assessment, and atomic absorption spectrometry, yielded significant results. The objective of this study was to examine the impact of calcium chloride concentration on the calcium content in alginate composites. Specifically, the study assessed how varying concentrations of the cross-linking solution (ranging from 0.5% to 2%) influence the calcium ion saturation within the composites. This investigation is essential for understanding the physicochemical properties of the materials, including calcium content, porosity, and specific surface area. The results are intended to identify the optimal cross-linking conditions that maximize calcium enrichment efficiency while preserving the material's structural integrity. The study found that higher calcium chloride concentrations in alginate cross-linking improve the formation of a porous structure, enhanced by two-stage freeze-drying. Increased calcium levels led to a larger surface area and pore volume, and significantly higher calcium content. Furthermore, assays of activated partial thromboplastin time (aPTT) showed a reduction in clotting time for alginate composites containing calcium ions, indicating their potential as hemostatic agents. The aPTT test showed shorter clotting times with higher calcium ion concentrations, without enhanced activation of the extrinsic clotting pathway. The developed alginate material with calcium effectively supports hemostasis and reduces the risk of infection. The study also explored the capacity of these composites to interact with and modify the structure of plasmid DNA, underscoring their potential for future biomedical applications.

Ammonia exposure impairs bone mineralization in zebrafish (Danio rerio) larvae

Ammonia is a major pollutant of freshwater environments. Previous studies have indicated that ammonia exposure adversely affects the physiology of freshwater fish. However, its effect on bone mineralization in freshwater fish larvae remains unclear. In this study, zebrafish larvae were used as a model to investigate the effects of different ammonia levels (0, 2.5, 5, and 10 mM NH4Cl) on the survival rate, body length, and bone mineralization of fish. The survival rate of zebrafish embryos exposed to different NH4Cl concentrations for 8 days was not affected. In contrast, the body length and bone mineralization of zebrafish larvae at 8 days post fertilization (dpf) were significantly reduced at 5 and 10 mM NH4Cl exposure. Further investigations revealed that ammonia exposure decreased the mRNA expression of osteoblast-related genes and increased that of osteoclast-related genes. Additionally, exposure to 5 mM and 10 mM NH4Cl induced the production of reactive oxygen species (ROS). 10 mM—but not 5 mM—NH4Cl exposure reduced the calcium and phosphorus content in 8 dpf zebrafish larvae. In conclusion, ammonia exposure induces bone resorption, while decreasing the calcium and phosphorus content of the whole body and bone formation, resulting in impaired bone mineralization in fish larvae.

Cerebral white matter damage in patients with end stage kidney disease associates with cognitive impairment

Abstract Background and hypothesis Damages in brain white matter often occurs in individuals with chronic kidney disease, which might be related to their cognitive decline. This study aims to investigate tract specific white matter damage in patients with end stage renal disease by using fixel based analysis. Methods Images of 31 end stage renal disease patients and 16 normal controls (aged: 61.1 ± 10.4 years; 11 men) were acquired from a 1.5 T MR scanner. The patients were subsequently divided into with normal cognition (N = 17, aged: 66.9 ± 7.2 years; 10 men) and cognitive impairment (N = 14, aged: 72.4 ± 9.4 years; 7 men). Cognitive assessment, neurologic, hematologic and biochemical samples were collected. Fixel-based analysis was used to examine the tract-specific damage within white matter. Differences between groups were evaluated through connectivity-based fixel enhancement and non-parametric permutation testing. Correlation with biomarkers was conducted through general linear model. Significance was determined with familywise error-corrected p-value < 0.05. Results Reduced fixel-based metrics were observed in specific tract located the cerebral peduncle, internal capsule, corpus callosum, fornix, and superior corona radiata in patients when compared to normal controls, indicating a reduction in fiber content. The fibers crossing the corpus callosum and the fornix/stria terminalis are particularly vulnerable sites, which can be associated with the decrease in both Mini-Mental State Examination (R2 ranged between 0.420 and 0.556) and Montreal Cognitive Assessment (R2 ranged between 0.425 and 0.509), as well as the plasma concentration of calcium (R2 ranged between 0.207 and 0.322). The plasma concentration of indoxyl sulfate was associated with the descending tracts from right posterior limb of internal capsule to cerebral peduncle (R2 ranged between 0.262 and 0.335). Conclusions Tract specific white matter damage can be noticed in the patients with end stage renal disease, and can be associated with their cognitive decline.

EP406 - Exploring the Nexus: Serum Fluoride, Lipid Profiles, and Gallstone Formation in a Cross-Sectional Study

Abstract Objectives Assessing and comparing serum fluoride and lipid profiles in individuals with gallstones and in healthy controls. Investigating the correlation between serum fluoride levels and lipid profiles specifically in gallstone cases. Estimating concentrations of fluoride, cholesterol, triglycerides, bilirubin, calcium, and magnesium in gallstones. Methods This cross-sectional study recruited twenty-five gallstone patients seeking evaluation and treatment at the General Surgery department over a two-month period. Twenty-five age- and gender-matched controls were enrolled using purposive sampling. Results Our findings revealed that, regardless of age group (26-70), individuals with higher serum lipid levels and gallstones exhibited fluoride levels in the gallstones ranging from 0.5 to 1 PPM, suggesting a positive impact of fluoride on gallstones. Notably, calcium and uric acid levels were significantly elevated, measuring 19 and 14 mg per gram, respectively. These finding prompts clinicians to consider the independent role of fluoride in regions with higher exposure and chronicity. Conclusion Our study uncovered a positive correlation between elevated serum lipid levels and gallstones, highlighting fluoride concentrations in gallstones ranging from 0.5-1 PPM. Increased calcium and uric acid levels, particularly in regions of heightened exposure, point to fluoride's independent role in gallstone formation. Patients with gallstones showed heightened lipid levels, positioning fluoride as an influential factor. Notably, cations like calcium and magnesium, alongside non-protein substances such as uric acid, displayed stronger associations with gallstones, with negligible gender-based differences. These findings offer clinicians valuable insights, underscoring the potential significance of fluoride and related factors in understanding and addressing gallstone disease.

Synthesis and Characterization of Nano-Crystallite Triple Super Phosphate (TSP) from Marine Mollusk Waste: Babylonia japonica, Oliva sayana, and Conasprella bermudensis.

The study aims to synthesize nano-crystallite TSP using renewable, low-cost, waste marine mollusk from three different species such as Babylonia japonica, Oliva sayana, and Conasprella bermudensis. The molar ratio of phosphate to calcium in triple superphosphate [TSP, Ca(H2PO4)2.H2O] significantly impacts its properties and fertilizer performance, in this case, we kept the ratio to 2. Raw TSP has a high phosphate content and lower calcium content. The synthesized TSP was analyzed using various techniques including TGA, XRD, EDX, FT-IR, and SEM. The study utilized multiple XRD model equations to analyze crystallite size ( ), with all models except the Liner straight-line method providing higher estimates for synthesized TSP. Furthermore, the values for stress (2×107 to 4×107 N/m2), strain (4×10-4 to 9×10-4), as well as energy density (4.54×103 to 16.27×103 J/m3) were also calculated for the synthesized product. However, the preferential growth calculation indicates that (010), (021), and (020) planes are the most thermodynamically stable planes for the growth of the synthesized TSP. Apart from that, FTIR result confirms that CaO, -OH, as well as PO4 3- functional groups are present in the synthesized products. This research suggests that marine mollusks can be utilized as a calcium precursor for P-fertilizer and 60 % phosphoric acid, thereby reducing production costs by eliminating additional dehydrating. Additionally, waste marine mollusk shells could be utilized as an alternative to the production of phosphate-based fertilizer.

Spatial Distribution Characteristics of Plant Community and the Identification of Driving Factors in Riparian Zone of the Three-River Headwaters Region, China

The unique geographical and climatic conditions in the Three-River Headwaters Region gave birth to distinctive plant species and vegetation types. To reveal the spatial distribution of plant communities and soil habitats along the riparian zone of the Sanjiangyuan Region and their influencing mechanisms, 14 survey plots were set up （ten from the Yangtze River source, two from the Lancang River source, and two from the Yellow River source）, and the effects of soil nutrient characteristics （especially soil phosphorus morphology）, climate factors, and river topography on plant community characteristics were quantitatively analyzed. The results showed that the plant community composition in the riparian zone of the source of the three rivers was dominated by perennial herbs （72.2%）, followed by annual herbs （20.4%） and shrubs （7.4%）. The dominant plants were Stipa purpurea, Polygonum orbiculatum, Carex parvula, Potentilla anserina, and Gentiana straminea. The average plant coverage, Shannon-Wiener index, and Pielou index were （64.4% ±23.6%）, （1.31 ±0.42）, and （0.84 ±0.08）, respectively. The plant community diversity index was the highest in the Yangtze River source, followed by that in the Lancang River source, and the lowest in the Yellow River source. The soil pH of the riparian zone of the Yangtze River source was significantly higher than that of the Lancang River source, whereas the mean contents of organic matter, total nitrogen, and Fe-Al combined phosphorus were significantly lower than those of the Lancang River source. The calcium and magnesium-combined phosphorus was the main form of phosphorus in riparian soil （63.89%）. Temperature, soil organic phosphorus content, and pH had significant effects on plant composition in the riparian zone of the Three-River Headwaters Region, whereas soil calcium and magnesium-combined phosphorus content had significant effects on plant community diversities. These results may deepen the scientific understanding of the evolution trend and genetic mechanism of plant communities in the riparian zone of the Three-River Headwaters Region.

Advancing Human iPSC-Derived Cardiomyocyte Hypoxia Resistance for Cardiac Regenerative Therapies through a Systematic Assessment of In Vitro Conditioning.

Acute myocardial infarction (MI) is a sudden, severe cardiac ischemic event that results in the death of up to one billion cardiomyocytes (CMs) and subsequent decrease in cardiac function. Engineered cardiac tissues (ECTs) are a promising approach to deliver the necessary mass of CMs to remuscularize the heart. However, the hypoxic environment of the heart post-MI presents a critical challenge for CM engraftment. Here, we present a high-throughput, systematic study targeting several physiological features of human induced pluripotent stem cell-derived CMs (hiPSC-CMs), including metabolism, Wnt signaling, substrate, heat shock, apoptosis, and mitochondrial stabilization, to assess their efficacy in promoting ischemia resistance in hiPSC-CMs. The results of 2D experiments identify hypoxia preconditioning (HPC) and metabolic conditioning as having a significant influence on hiPSC-CM function in normoxia and hypoxia. Within 3D engineered cardiac tissues (ECTs), metabolic conditioning with maturation media (MM), featuring high fatty acid and calcium concentration, results in a 1.5-fold increase in active stress generation as compared to RPMI/B27 control ECTs in normoxic conditions. Yet, this functional improvement is lost after hypoxia treatment. Interestingly, HPC can partially rescue the function of MM-treated ECTs after hypoxia. Our systematic and iterative approach provides a strong foundation for assessing and leveraging in vitro culture conditions to enhance the hypoxia resistance, and thus the successful clinical translation, of hiPSC-CMs in cardiac regenerative therapies.

Effect of low-heat cement Portland cement on alkali-silica reaction of aggregates with different alkali-reactivities

This study investigated the impact of cement clinker percentages on the alkali-silica reaction (ASR) mechanisms of aggregates with varying alkali-silica reactivity. Experimental findings indicated that the low-heat Portland cement (LHC) mitigated the development of the ASR process in soda-lime glass aggregate (SLGA) concrete. The ASR in ordinary Portland cement (OPC) mainly initiated within the SLGA, leading to crack propagation through the matrix. The in-situ X-ray micro-computed tomography test indicated that LHC altered the manifestation of ASR in concrete containing SLGA, leading to different destructive forms. Specifically, ASR between the LHC and SLGA primarily occurred at the periphery of the SLGA. The in-situ quantity analysis results illustrated that the LHC mitigated the ASR-induced cracks in the SLGA concrete. For the less alkali-reactive natural aggregate, the effect of LHC cement on ASR was diminished. ASR still only occurred within the natural aggregate concrete, distributing in highly alkali-reactive phases inside the aggregates. The chemical analysis results supposed that the differing ASR pathways could be attributed to the interaction between the calcium content in the LHC and the spatial distribution of alkali-reactive phases within the aggregates. These findings help interpret the mechanism of the slower ASR process in the belite-rich cement concrete.

Revolutionizing Bone Regeneration with Grinder-Based Dentin Biomaterial: A Systematic Review.

Bone tissue regeneration is a critical aspect of dental surgery, given the common occurrence of bone resorption leading to alveolar bone defects. The aim of this paper was to conduct a systematic review to provide a comprehensive summary of the evidence regarding the regenerative properties of dentin biomaterial. This systematic review was conducted through comprehensive searches in the PubMed, Scopus, and Web of Science databases, as well as an extensive exploration of the gray literature sources, including WorldCat, The New York Academy of Medicine Library, and Trip Database, following the established PRISMA protocol. Keywords such as tooth, dentin, grinder, and autograft guided the search, with a focus on a standardized procedure involving dentin grinders within laboratory, experimental, and clinical settings. Initially, a pool of 1942 articles was identified with 452 duplicates removed. An additional 1474 articles were excluded for not aligning with the predefined topics, and three more were excluded due to the unavailability of the full text. Ultimately, 13 articles met the strict inclusion criteria and were included in the review. The chemical composition of the dentin particles was similar to natural bone in terms of oxygen, carbon, calcium, phosphorus, sodium, and magnesium content, as well as in terms of the Ca/P ratio. In addition, the dentin also contained amide I and amide II structures, as well as aliphatic and hydroxyl functional groups. The chemically treated dentin was free of microorganisms. The dentin had characteristic tubules that opened after chemical treatment. At the cellular level, dentin released bone morphogenetic protein 2, induced significant cell growth, and stimulated the reorganization of the fibroblast cytoskeleton. Most clinical studies have focused on alveolar bone regeneration. After the transplantation of demineralized dentin particles, studies have observed new bone formation, a reduction in residual bone, and an increase in connective tissue. Clinical reports consistently indicate uncomplicated healing and recovery post-transplantation. However, there is a notable gap in the evidence concerning complication rates, patient-reported outcomes, and the presence of pro-inflammatory factors. In conclusion, dentin biomaterial emerges as a versatile bone substitute, demonstrating high biocompatibility and ease of acquisition. The preservation of its internal structure containing organic matter and growth factors enhances its potential for effective bone regeneration. Particularly, in dental surgery, dentin-derived materials present a promising alternative to traditional autologous bone autografts, offering the potential to reduce patient morbidity and treatment costs.

Genome-Wide Interaction Analyses of Serum Calcium on Ventricular Repolarization Time in 125 393 Participants.

Ventricular repolarization time (ECG QT and JT intervals) is associated with malignant arrhythmia. Genome-wide association studies have identified 230 independent loci for QT and JT; however, 50% of their heritability remains unexplained. Previous work supports a causal effect of lower serum calcium concentrations on longer ventricular repolarization time. We hypothesized calcium interactions with QT and JT variant associations could explain a proportion of the missing heritability. We performed genome-wide calcium interaction analyses for QT and JT intervals. Participants were stratified by their calcium level relative to the study distribution (top or bottom 20%). We performed a 2-stage analysis (genome-wide discovery [N=62 532] and replication [N=59 861] of lead variants) and a single-stage genome-wide meta-analysis (N=122 393, [European ancestry N=117 581, African ancestry N=4812]). We also calculated 2-degrees of freedom joint main and interaction and 1-degree of freedom interaction P values. In 2-stage and single-stage analyses, 50 and 98 independent loci, respectively, were associated with either QT or JT intervals (2-degrees of freedom joint main and interaction P value <5×10-8). No lead variant had a significant interaction result after correcting for multiple testing and sensitivity analyses provided similar findings. Two loci in the single-stage meta-analysis were not reported previously (SPPL2B and RFX6). We have found limited support for an interaction effect of serum calcium on QT and JT variant associations despite sample sizes with suitable power to detect relevant effects. Therefore, such effects are unlikely to explain a meaningful proportion of the heritability of QT and JT, and factorsincluding rare variation and other environmental interactions need to be considered.

Effect of calcium concentration on metastasis of hepatocellular carcinoma cells cultured in alginate gel beads

Changes in sodium alginate and calcium ion concentrations have a considerable impact on the structural properties of calcium alginate gel (ALG) beads, consequently influencing the biological characteristics of the cells encapsulated within them. This study aimed to examine the effects of calcium on the metastatic potential of hepatocellular carcinoma (HCC) cells encapsulated in ALG beads. The results showed that the invasion ability of HCC cells significantly increased when they were encapsulated in beads prepared with a calcium concentration of 200 mM compared to those prepared with a calcium concentration of 50 mM. Furthermore, the expression levels of genes related to metastasis were significantly elevated in ALG beads prepared with a calcium concentration of 200 mM. Specifically, the expression of activated matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and urokinase-type plasminogen activator system proteins was found to be high. Conversely, the expression of phosphatase and tensin homolog deleted on chromosome 10 was observed to be significantly reduced. These findings indicate that manipulating the calcium ion concentration during the fabrication of ALG beads enables the generation of three-dimensional HCC cells with varying metastatic capacities. This model offers a valuable tool for investigating the mechanisms underlying liver cancer metastasis and screening potential therapeutic drugs.

Physicochemical analysis of trigona honey produced by Tetragonula biroi in Soppeng Regency, Indonesia

Indonesia is a country with a tropical climate that is rich in biodiversity. Various types of bees are discovered in the country, including the trigona bees, whose honey offers numerous health benefits. This study aimed to analyze the nutritional and phytochemical content of trigona honey produced by Tetragonula biroi in Soppeng Regency, South Sulawesi, Indonesia. The honey samples are extracted directly from the hives, filtered and examined through laboratory tests. The results of this study showed that trigona honey from Soppeng has a low pH (4.5) and a high vitamin C content compared to other vitamins. The calcium content is higher than magnesium and zinc, while its high polyphenols contain flavonoids and antioxidants. The water content of 26.67% is indicated in trigona honey, which is within the acceptable range of the Indonesian National Standard (SNI). The sugar content of trigone honey indicates 6.99% w/w glucose, 12.96% w/w fructose and a fructose/glucose ratio of 1.85.

Study of the Synchronization and Transmission of Intracellular Signaling Oscillations in Cells Using Bispectral Analysis.

The oscillation synchronization analysis in biological systems will expand our knowledge about the response of living systems to changes in environmental conditions. This knowledge can be used in medicine (diagnosis, therapy, monitoring) and agriculture (increasing productivity, resistance to adverse effects). Currently, the search is underway for an informative, accurate and sensitive method for analyzing the synchronization of oscillatory processes in cell biology. It is especially pronounced in analyzing the concentration oscillations of intracellular signaling molecules in electrically nonexcitable cells. The bispectral analysis method could be applied to assess the characteristics of synchronized oscillations of intracellular mediators. We chose endothelial cells from mouse microvessels as model cells. Concentrations of well-studied calcium and nitric oxide (NO) were selected for study in control conditions and well-described stress: heating to 40 °C and hyperglycemia. The bispectral analysis allows us to accurately evaluate the proportion of synchronized cells, their synchronization degree, and the amplitude and frequency of synchronized calcium and NO oscillations. Heating to 40 °C increased cell synchronization for calcium but decreased for NO oscillations. Hyperglycemia abolished this effect. Heating to 40 °C changed the frequencies and increased the amplitudes of synchronized oscillations of calcium concentration and the NO synthesis rate. The first part of this paper describes the principles of the bispectral analysis method and equations and modifications of the method we propose. In the second part of this paper, specific examples of the application of bispectral analysis to assess the synchronization of living cells in vitro are presented. The discussion compares the capabilities of bispectral analysis with other analytical methods in this field.

Assessment of Calcium Concentration and pH at the Periapical Environment on Placing Calcium Hydroxide with Different Natural Vehicles – An In vitro Study

Abstract Background: In root canal therapy, the number of microorganisms in canals can be controlled by giving proper intracanal medication dressing. Calcium concentration and changes in pH at the periapical region denote the effect of antibacterial action in the periapical region. Aim: The aim is to determine a suitable natural vehicle for calcium hydroxide (Ca(OH)2) as an intracanal medicament by assessing the calcium concentration and changes in pH at the periapical region. Materials and Methods: A total of 60 extracted single-rooted permanent teeth were equally allotted into four groups – Group I: Ca(OH)2 with distilled water, Group II: Ca(OH)2 with aloe vera, Group III: Ca(OH)2 with coconut water, and Group IV: Ca(OH)2 with neem extract. pH was determined by pH meter and calcium by chromatography. The values were taken on days 1, 2, 3, 7 and 14. Results: All the materials showed alkaline pH and release of calcium ion throughout the study. For day 1, the mean pH value was highest for distilled water (10.06) and lowest for aloe vera extract (9.42). The highest calcium release during day 1 was by coconut water (67.85) and the least calcium release was by aloe vera (42.01). On day 14, the highest calcium release was by distilled water (89.98) followed by coconut water (67.24) and least by neem extract (61.13). pH values and calcium release in four different natural vehicles were significant (P &lt; 0.05). Conclusion: All natural materials used in this study showed good Ca(OH)2 diffusion when used as a vehicle with Ca(OH)2 in root canals.