Increase In Calcium Concentration Research Articles

Determination of phytochemical quality of leaves Vaccinium vitis-idaea L. and Vaccinium myrtillus L. from the polluted and non-polluted areas

Elemental composition of Vaccinium myrtillus L. and Vaccinium vitis-idaea L. has not been determined yet in detail. In our study, a scanning electron microscope coupled with an energy dispersive X-ray analyser (SEM–EDX) ensured the determination of 15 elements in the leaves of Vaccinium sp. growing in the control and the mine polluted locality. The soil elemental analyses showed a higher content of 11 elements from all determined in the mine-influenced samples. Elemental analyses of the control leaves showed the highest contents of all determined elements for V. vitis-idaea, except for carbon. The impact of pollution on V. myrtillus leaves caused significant increase in oxygen, natrium, magnesium, sulphur, chlorine, potassium and calcium content. The contents of carbon, nitrogen and silicon decreased substantially. In the case of the V. vitis-idaea leaves, the content of most of elements reduced, and in the case of six elements, even significantly. A significant increase was recorded for carbon, iron and copper. The effect of the environment has influenced the production of phytochemicals, assessed by HPLC–DAD. The production of flavonoids (hyperoside, isoquercetin) increased significantly in V. myrtillus and decreased to a detectable minimum in V. vitis-idaea. In the case of chlorogenic acid, arbutin and hydroquinone, their levels changed minimally in V. myrtillus, but significantly more in the V. vitis-idaea leaves. The importance of elemental analyses lies in detecting the presence of toxic elements or their harmful concentrations in plants that are the source of food or dietary supplements.

HuR-dependent expression of RyR2 contributes to calcium-mediated thermogenesis in brown adipocytes.

Several uncoupling protein 1 (UCP1)-independent thermogenic pathways have been described in thermogenic adipose tissue, including calcium-mediated thermogenesis in beige adipocytes via sarco/endoplasmic reticulum ATPase (SERCA). We have previously shown that adipocyte-specific deletion of the RNA binding protein human antigen R (HuR) results in thermogenic dysfunction independent of UCP1 expression. RNA sequencing revealed the downregulation of several genes involved in calcium ion transport upon HuR deletion. The goal of this work was to define the HuR-dependent mechanisms of calcium driven thermogenesis in brown adipocytes. We generated (BAT)-specific HuR-deletion (BAT-HuR -/- ) mice and show that their body weight, glucose tolerance, brown and white adipose tissue weights, and total lipid droplet size were not significantly different compared to wild-type. Similar to our initial findings in Adipo-HuR -/- mice, mice with BAT-specific HuR deletion are cold intolerant following acute thermal challenge at 4°C, demonstrating specificity of acute HuR-dependent thermogenesis to BAT. We also found decreased expression of ryanodine receptor 2 (RyR2), but no changes in RyR2, SERCA1, SERCA2, or UCP1 expression, in BAT from BAT-HuR -/- mice. Next, we used Fluo-4 calcium indicator dye to show that genetic deletion or pharmacological inhibition of HuR blunts the increase in cytosolic calcium concentration in SVF-derived primary brown adipocytes. Moreover, we saw a similar blunting in β-adrenergic-mediated heat generation, as assessed by ERtherm AC fluorescence, in SVF-derived brown adipocytes following HuR inhibition or deletion. Mechanistically, we show that HuR directly binds and reduces the decay rate of RyR2 mRNA in brown adipocytes, and stabilization of RyR2 via S107 rescues β-adrenergic-mediated cytosolic calcium increase and heat generation in HuR deficient brown adipocytes. In conclusion, our results suggest that HuR-dependent control of RyR2 expression plays a significant role in the thermogenic function of brown adipose tissue through modulation of SR calcium cycling.

The Influence of Particle Size and Calcium Content on Performance Characteristics of Metakaolin- and Fly-Ash-Based Geopolymer Gels.

This research systematically investigates the influence of raw material particle size and calcium content on the geopolymerization process to gain insight into the physical and mechanical properties of geopolymer gels, including setting time, fluidity, pore structure, compressive strength, and leaching characteristics of encapsulated Cr3+ heavy metal ions. Utilizing a diverse range of particle sizes of metakaolin (MK; 3.75, 7.5, and 12 µm) and fly ash (FA; 18, 45, and 75 µm), along with varied calcium levels, this study assesses the dual impact of these factors on the final properties of both metakaolin- and fly-ash-based geopolymers. Employing sophisticated analytical techniques such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR), the research meticulously documents alterations in chemical bonding, micro-morphology, and pore structures. Key findings reveal that reducing the size of MK and FA particles to 3.75 and 18 µm, respectively, enhances the compressive strength of their matrices by 128.37 and 297.58%, respectively, compared to their original values (63.59 and 33.87 MPa, respectively) at larger particle sizes. While smaller particle sizes significantly bolster compressive strength, they adversely affect slurry flow and reduce the leaching rates of Cr3+ from MK- and FA-based matrices, reaching 0.42 and 0.75 mg/L at 3.75 and 18 µm, respectively. Conversely, increased calcium content markedly enhances setting times and contributes to the formation of dense microstructures through the production of calcium aluminate silicate hydrate (C-A-S-H) gels, thus improving the overall curing performance and durability of the materials. These insights underline the importance of fine-tuning particle size and calcium content to optimize geopolymer formulations, offering substantial benefits for varied engineering applications and promoting more sustainable construction practices.

Comparative Study on Calcium-enriched Finger Millet Tisane: Optimizing Soaking and Roasting Methods

This study focuses on the development of a calcium-rich herbal tisane using finger millet, a grain known for its high calcium content, aimed at enhancing dietary calcium intake. Two distinct processing methods were employed to optimize the calcium content of the tisane. In Treatment 1, Finger millet was roasted and combined with spice powder, while in Treatment 2, Finger millet underwent soaking, cabinet drying, roasting, and then blending with spice powder. The calcium content and overall quality of both treatments were evaluated, revealing a marginal increase in calcium concentration in Treatment 2, attributed to the additional processing steps. Specifically, Treatment 2 yielded a maximum calcium content of 396 mg compared to 380 mg in Treatment 1, demonstrating the effectiveness of the additional soaking and drying steps in enhancing calcium bioavailability. The final product was further enriched with a blend of spices, including dry ginger, cinnamon, cardamom, Arjuna bark, fennel seeds, and Tulsi leaves, contributing to its healthful properties. Organoleptic evaluations, conducted to assess sensory attributes such as flavor, aroma, and overall acceptability, indicated that both treatments were well-received by consumers. This suggests the product's potential for consumer acceptance and market viability. The findings suggest that calcium-enriched Finger millet tisane could serve as a valuable functional beverage, particularly for populations at risk of calcium deficiency. Its nutrient profile, combined with favorable sensory attributes, positions it as a promising option for improving dietary calcium intake and promoting overall health. Further research on larger sample sizes and bioavailability studies could reinforce its potential as a functional health beverage.

Long-term rice-crayfish farming alters soil dissolved organic carbon quality and biodegradability by regulating microbial metabolism and iron oxidation

The biodegradability of dissolved organic carbon (DOC) is a crucial process in the migration and transformation of soil organic carbon (SOC), and play a vital role in the global soil carbon (C) cycle. Although the significance of DOC in SOC transportation and microbial utilization is widely acknowledged, the impact of long-term rice-crayfish (RC) farming on the content, quality, and biodegradability of DOC in paddy soils, as well as regulatory mechanisms involved, remains unclear. To address this gap, a space-for-time method was employed to investigate the effects of different RC farming durations (1-, 5-, 10-, 15-, and 20- years) on the quality and biodegradability of DOC, as well as their relationship with soil microbial metabolism and minerals in this study. The results revealed that continuous RC farming increased the soil DOC content, but reduced DOC biodegradability. Specifically, after 20 years of continuous RC farming, the DOC content increased by 52.7% compared to the initial year, whereas the DOC biodegradability decreased by 63.4%. Analysis using three-dimensional fluorescence and ultraviolet spectroscopy demonstrated that continuous RC farming resulted in a decrease in the relative abundance of humus-like fractions, humification, and aromaticity indexes in DOC, but increased the relative abundance of protein-like fractions, biological, and fluorescence index, indicating that long-term RC farming promoted the simple depolymerization of the molecular structure of DOC. Continuous RC farming increased the activity of hydrolase involved in soil nitrogen (N) and phosphorus (P) cycles and oxidase, but decreasing the hydrolase C/N and C/P acquisition ratios; moreover, it also stimulated an increase in soil iron oxides and exchangeable calcium content. Structural equation modeling suggests that soil hydrolases and iron oxides are the primary drivers of DOC quality change, with DOC biodegradability being driven solely by soil iron oxides and not regulated by DOC quality. In conclusion, long-term RC farming promotes the catalytic decomposition of DOC aromatic substances and the production of DOC protein-like components by increasing soil oxidase activity and decreasing the hydrolase C/N acquisition ratio; these processes collectively contribute to the simple depolymerization of DOC molecular structure. Additionally, long-term RC farming induced legacy effects of soil iron oxides and enhanced chemical protection role leading to reduced DOC biodegradability. These findings suggested that long-term RC farming may reduce the rapid turnover and loss of DOC, providing a negative feedback on climate warming.

A-039 Parathyroid Hormone and Vitamin D Follow an Inversely Correlated Serum Level

Abstract Background Parathyroid hormone (PTH) is a polypeptide responsible for regulating the physiological level of serum calcium through a complex homeostatic process closely associated with bone metabolism. In response to a decreased serum concentration of calcium, PTH level is increased leading to the elevation of calcium via bone resorption. Furthermore, Vitamin D (Vit-D) is a critical component of the endocrine system that also contributes to calcium homeostasis. Vit-D increases the level of serum calcium by stimulating intestinal absorption and renal reabsorption. Vit-D impacts the serum level of PTH by two distinct mechanisms. First indirectly, an increase in serum concentration of calcium, caused by Vit-D-mediated intestinal absorption and renal reabsorption disengages the process of PTH release through interaction with calcium-sensing receptors on parathyroid cells. Secondly, Vit-D directly interacts with parathyroid cells resulting in a reduced expression of PTH. Taken together, Vit-D is assumed to negatively impact the serum level of PTH. This study examined the homeostatic correlation between the circulating concentrations of Vit-D and PTH. Methods Retrospective serum concentrations of PTH and Vit-D were retrieved from the biochemical profiles of hospitalized and ambulatory patients who presented to or admitted at the tertiary care level hospital of University of Texas Southwestern Medical Center during the period between July-to-September of 2021. Correlation analysis between Vit-D and PTH was performed using GraphPad-PRISM-version-8. Results A total of 163 corresponding serum Vit-D and PTH values were obtained. Vit-D and PTH values displayed an inverse correlation (Figure 1). Pearson r values for linear and logarithmic trendlines (-0.6745 and -0.785, respectively) demonstrated a negative correlation between Vit-D and PTH. Conclusions Measuring Vit-D and PTH levels are critically important for assessing the homeostatic status of calcium. PTH level maintains an inverse relationship with Vit-D. Therefore, therapeutic targeting of Vit-D or PTH would mutually affect their concentration eventually reflected in calcium homeostasis.

Evaluating Groundwater Quality for Drinking and Irrigation Purposes and Health Risk Assessment in West Midnapore District of West Bengal, India

Groundwater quality in the West Midnapore district of West Bengal, India is affected by anthropogenic activities as well as by water quality of Subarnarekha and Kangsabati rivers. This study aims to assess quality of groundwater and river water for drinking and irrigation usage, and assess the health risks of the people consuming the water across the rivers. The study also explores the groundwater-river water interaction. The river water and groundwater samples were collected three times during monsoon season from 14 sites across the rivers. The samples were analyzed for 11 water quality parameters, i.e., pH, total dissolved solids (TDS), total hardness (TH), major anions and cations, and iron (Fe). The groundwater was found slightly acidic (mean pH ~ 6.71) and correlated with nitrate concentrations. Most of the water quality parameters were found within their permissible limits of drinking water. However, elevated concentrations of potassium (K), ammonium (NH4), magnesium (Mg), phosphate (PO4), sodium (Na), and Fe were detected at some places, which were likely due to use of fertilizers. Water quality index (WQI), sodium absorption ratio (SAR), and percentage Na values were computed to evaluate the groundwater quality. The mean WQI value of 37.07 showed that the majority of groundwater samples met drinking water standards. Groundwater was also found suitable for irrigation (SAR ~ 0.26 to 1.62 meq L-1 and percentage Na ~ 13.10% to 78.12%). Health risk assessments suggested minimal immediate risks, though high Na levels in certain areas raised concerns. Piper plot showed that increased calcium concentrations in groundwater were mainly due to interactions between river water and groundwater. Overall, groundwater quality did not present any harmful health hazards to the community. The findings of this study can be instrumental for groundwater managers in identifying potential areas for treating groundwater quality.

Synergistic effect of cerium chloride and calcium chloride alters calcium signaling in keratinocytes to promote epidermal differentiation.

Epidermal keratinocytes undergo morphological and functional changes during differentiation, eventually being enucleated to become corneocytes. Calcium has been shown to be involved in various cellular functions of epidermal cells, including proliferation, differentiation, and apoptosis. Cerium is a lanthanide-series element and rare earth metal. For skin, cerium oxide has been investigated for use in absorbing UV and promoting wound healing. However, the functions and physiological effects of inorganic cerium on the skin have rarely been investigated. Here, we focused on cerium's function in epidermal keratinocytes and its interaction with calcium by investigating their effects on cell differentiation and intracellular calcium concentration. This study showed that applying cerium chloride to epidermal keratinocytes altered calcium signaling. It also suggested that cerium and calcium induced an increase in intracellular calcium concentration and promoted keratinocyte differentiation.

Salinity Tolerance Mechanism of Crithmum maritimum L.: Implications for Sustainable Agriculture in Saline Soils

Edible halophytes are attracting attention due to their potential for agriculture in saline and marginal areas. The salt tolerance mechanism was analyzed in Crithmum maritimum L., based on ionic, osmotic, and redox homeostasis strategies under salt stress. The methodology involved growing C. maritimum seeds in pots under controlled greenhouse conditions and exposing them to different NaCl concentrations (0, 100, 200, and 300 mM) for five months. High salinity levels decreased plant length and biomass, but the shoot-to-root length and biomass ratio increased significantly. Photosynthetic pigments (chlorophyll and carotenoids) were quantified using spectrophotometric analysis, while macro- and micro-nutrient contents were determined via the Kjeldahl method, flame photometry, and atomic absorption spectrophotometry. Osmolyte accumulation, including proline and glycine betaine, was analyzed using specific biochemical assays, and antioxidant enzyme activities (SOD, CAT, and POX) were measured to assess redox homeostasis. Photosynthetic pigments in C. maritimum leaves slightly increased at 100 mM NaCl, but significantly declined at 200 and 300 mM NaCl. A high Na content in the shoots indicated no restriction in mineral uptake in the roots. Nitrogen and phosphorus slightly decreased under high salinity. The cation content in the shoots varied: potassium decreased, while calcium and magnesium increased with salinity, although the Mg+2/Na+ and K+/Na+ ratios showed similar declining patterns. The micro-nutrients iron and manganese increased in the shoots, while copper remained unchanged. The content of osmolytes proline and glycine betaine significantly increased under the 200 and 300 mM NaCl treatments. Antioxidant enzyme activities (SOD, CAT, and POX) decreased at 100 and 200 mM NaCl, but were strongly induced at 300 mM NaCl. The total antiradical activity of the leaves increased with higher salinity levels. Our results indicated that the facultative halophyte characteristics of C. maritimum emerged after exposure to 200 mM NaCl. Increased calcium content may be a key factor in salinity tolerance. We concluded that C. maritimum employs strong osmotic adjustment and redox homeostasis mechanisms, making it a promising candidate for cultivation in saline environments.

Designing calcium-fortified milk for improving stability and calcium bioaccessibility by solid dispersion emulsification

Approximately 70 % of the calcium intake in the adult diet worldwide is derived from dairy products. However, insoluble calcium salts, which are usually added directly during dairy production, have poor suspension stability and are prone to precipitation. The current study aimed to address the constraints of conventional production methods by utilizing solid dispersion emulsification technology to inhibit the aggregation of calcium salts. Calcium-fortified milk samples with different calcium content were prepared and compared with the commercial calcium-fortified milk, and their physicochemical, microstructural, and digestive properties were characterized. The results of this study demonstrated that all the prepared calcium-fortified milk samples exhibited a particle size of approximately 270 nm and a zeta-potential of approximately −40 mV. The calcium-fortified milk, which has been produced using solid dispersed emulsion technology, has been found to have 1.8 times more physical stability than commercial milk. Microstructural studies showed that aggregation of milk with more than 225 mg/100 mL calcium content occurred. During in-vitro digestion, it was found that the increasing calcium loading did not impact protein digestion without the creation of new fragments in the calcium-fortified milk. Calcium bioaccessibility was enhanced by approximately 50 % in comparison with the commercial product. While the release of free fatty acids was found to decrease with increasing calcium content. This study facilitates the development and utilization of calcium-fortified and low-fat foods and provides a new idea for the addition of milk minerals in dairy products.

Cm(III) speciation in the presence of citrate from neutral to hyperalkaline conditions and the effect of calcium

We investigated the binary Cm-citrate system using time-resolved laser fluorescence spectroscopy (TRLFS), parallel factor analysis (PARAFAC), and quantum chemical calculations. Evidence collectively suggests the stepwise coordination and deprotonation of citrate alcohol groups in Cm-cit complexes with two bound citrate moieties upon increasing pH, which is supported by a bathochromic shift in emission spectra, an observed increase in lifetime measurements, and lower energy minima for citrate alcohol involvement versus hydrolysis of the Cm-citrate species. Our PARAFAC results agree with a 3-component model for the Cm-citrate system and offer pure component decompositions, yielding fraction species across the studied pH range that have a correlated slope = 1 as a function of pH. For the first time, evidence of ternary Ca-Cm-citrate complexes was revealed by TRLFS with increasing calcium concentration at fixed pHm. The formation of these ternary complexes was substantiated with density functional theory (DFT) calculations on simple model systems of the complexes. Shared citrate carboxylate groups between calcium and curium were proposed for all three ternary Ca-Cm-cit complexes based on DFT-determined Ca–O and Cm–O distances. Moreover, we found that the ternary complex with both alcohol groups deprotonated is most stable when it shares both two carboxylate and two alcohol groups between Ca and Cm. The presence of shared functional groups highlights the enhanced stability of these ternary complexes. Additional work is warranted to further constrain the stoichiometry, stability constants and dependence on ionic strength of these complexes for purposes of thermodynamic modeling of repository settings.

Feasibility of increasing calcium content of drinking tap water following quality regulations to improve calcium intake at population level.

Calcium intake is below recommendations in several parts of the world. Improving calcium intake has benefits not only for bone health but also helps to prevent pregnancy hypertension disorders. Calcium concentration of tap water is usually low The aim of the present study was to determine the maximum amount of calcium that can be added to tap water while complying with drinking water Argentine regulations. Tap water samples were collected from the Province of Buenos Aires (Argentina). Physicochemical properties and saturation index were measured. Different incremental concentrations of calcium chloride were added to the experimental aliquots. Baseline water had a mean calcium concentration of 22.00 ± 2.54 mg/L, water hardness of 89.9 ± 6.4 mg/L CaCO 3, and a saturation index of -1.50 ± 0.11. After the addition of 0.4554 ± 0.0071 g of salt, water hard-ness reached 355.0 ± 7.1 mg/L CaCO 3, a calcium concentration of 140.50 ± 2.12 mg/L, and a saturation index -0.53 ± 0.02. This study shows that at laboratory level it is feasible to increase calcium concentration of drinking water by adding calcium chloride while complying with national standards. Calcium concentration of drinking tap water could be evaluated and minimum calcium concentration of tap water regulated so as to improve calcium intake in populations with low calcium intake.

Au-modified ceria nanozyme prevents and treats hypoxia-induced pulmonary hypertension with greatly improved enzymatic activity and safety

BackgroundDespite recent advances the prognosis of pulmonary hypertension remains poor and warrants novel therapeutic options. Extensive studies, including ours, have revealed that hypoxia-induced pulmonary hypertension is associated with high oxidative stress. Cerium oxide nanozyme or nanoparticles (CeNPs) have displayed catalytic activity mimicking both catalase and superoxide dismutase functions and have been widely used as an anti-oxidative stress approach. However, whether CeNPs can attenuate hypoxia-induced pulmonary vascular oxidative stress and pulmonary hypertension is unknown.ResultsIn this study, we designed a new ceria nanozyme or nanoparticle (AuCeNPs) exhibiting enhanced enzyme activity. The AuCeNPs significantly blunted the increase of reactive oxygen species and intracellular calcium concentration while limiting proliferation of pulmonary artery smooth muscle cells and pulmonary vasoconstriction in a model of hypoxia-induced pulmonary hypertension. In addition, the inhalation of nebulized AuCeNPs, but not CeNPs, not only prevented but also blunted hypoxia-induced pulmonary hypertension in rats. The benefits of AuCeNPs were associated with limited increase of intracellular calcium concentration as well as enhancement of extracellular calcium-sensing receptor (CaSR) activity and expression in rat pulmonary artery smooth muscle cells. Nebulised AuCeNPs showed a favorable safety profile, systemic arterial pressure, liver and kidney function, plasma Ca2+ level, and blood biochemical parameters were not affected.ConclusionWe conclude that AuCeNPs is an improved reactive oxygen species scavenger that effectively prevents and treats hypoxia-induced pulmonary hypertension.Graphical

MSR1-dependent efferocytosis improved ischemia-reperfusion injury following aged-donor liver transplantation in mice by regulating the pro-resolving polarisation of macrophages

Compared with young liver donors, aged liver donors are more susceptible to ischemia-reperfusion injury (IRI) following transplantation, which may be related to excessive inflammatory response and macrophage dysfunction, but the specific mechanism is unclear. Macrophage scavenger receptor 1 (MSR1) is a member of the scavenger receptor family, and plays an important regulatory role in inflammation response and macrophage function regulation. But its role in IRI following aged-donor liver transplantation is still unclear. This study demonstrates that MSR1 expression is decreased in macrophages from aged donor livers, inhibiting their efferocytosis and pro-resolving polarisation. Decreased MSR1 is responsible for the more severe IRI suffered by aged donor livers. Overexpression of MSR1 using F4/80-labelled AAV9 improved intrahepatic macrophage efferocytosis and promoted pro-resolving polarisation, ultimately ameliorating IRI following aged-donor liver transplantation. In vitro co-culture experiments further showed that overexpression of MSR1 promoted an increase in calcium concentration, which further activated the PI3K-AKT-GSK3β pathway, and induced the upregulation of β-catenin. Overall, MSR1-dependent efferocytosis promoted the pro-resolving polarisation of macrophages through the PI3K-AKT-GSK3β pathway-induced up-regulating of β-catenin leading to improved IRI following aged-donor liver transplantation.

Chlamydia-containing spheres are a novel and predominant form of egress by the pathogen Chlamydia psittaci.

The egress of intracellular bacteria from host cells and cellular tissues is a critical process during the infection cycle. This process is essential for bacteria to spread inside the host and can influence the outcome of an infection. For the obligate intracellular Gram-negative zoonotic bacterium Chlamydia psittaci, little is known about the mechanisms resulting in bacterial egress from the infected epithelium. Here, we describe and characterize Chlamydia-containing spheres (CCSs), a novel and predominant type of non-lytic egress utilized by Chlamydia spp. CCSs are spherical, low-phase contrast structures surrounded by a phosphatidylserine-exposing membrane with specific barrier functions. They contain infectious progeny and morphologically impaired cellular organelles. CCS formation is a sequential process starting with the proteolytic cleavage of a DEVD tetrapeptide-containing substrate that can be detected inside the chlamydial inclusions, followed by an increase in the intracellular calcium concentration of the infected cell. Subsequently, blebbing of the plasma membrane begins, the inclusion membrane destabilizes, and the proteolytic cleavage of a DEVD-containing substrate increases rapidly within the whole infected cell. Finally, infected, blebbing cells detach and leave the monolayer, thereby forming CCS. This sequence of events is unique for chlamydial CCS formation and fundamentally different from previously described Chlamydia egress pathways. Thus, CCS formation represents a major, previously uncharacterized egress pathway for intracellular pathogens that could be linked to Chlamydia biology in general and might influence the infection outcome in vivo.IMPORTANCEHost cell egress is essential for intracellular pathogens to spread within an organism and for host-to-host transmission. Here, we characterize Chlamydia-containing sphere (CCS) formation as a novel and predominant non-lytic egress pathway of the intracellular pathogens Chlamydia psittaci and Chlamydia trachomatis. CCS formation is fundamentally different from extrusion formation, the previously described non-lytic egress pathway of C. trachomatis. CCS formation is a unique sequential process, including proteolytic activity, followed by an increase in intracellular calcium concentration, inclusion membrane destabilization, plasma membrane blebbing, and the final detachment of a whole phosphatidylserine-exposing former host cell. Thus, CCS formation represents an important and previously uncharacterized egress pathway for intracellular pathogens that could possibly be linked to Chlamydia biology, including host tropism, protection from host cell defense mechanisms, or bacterial pathogenicity.

Peat Stabilization by Using Ordinary Portland Cement (OPC) Mixed with Rice Husk Ash (RHA)

Peat generally consists of high organic and water contentthatcauses the strength of peat soil to be very weak to bear any load. The strength of the soil can be increased by using binders like cement in peat soil stabilizationtechniques, but excessive cement use can pollute the ecosystem. This study aimed to determine the ideal proportion of rice husk ash (RHA) to be utilized in place of cement. A test of the basic characteristics of peat soil is carried out in order to identify the nature of peat soil. The strength of treated and untreated peat soil was determined through an unconfined compression test (UCS). By replacement at 15%, the result shows the replacement of 15% RHA in Ordinary Portland Cement (OPC) demonstrates the maximum strength with the value of 531 kN/m² and 580 kN/m² for 7 and 28 curing days respectively. The microstructure image shows the difference in total porosity between the untreated and treated samples through the Scanning Electron Microscopy (SEM) test. A chemical test via Energy Dispersive X-ray (EDX) shows that the strength of samples improveswhen the amount of carbon reduces and calcium content increases. The findings illustrate that the utilization of discarded agricultural waste can be used as an additive in reducing the consumption of cement to increase the strength of peat based on soil stabilization techniques.

A comparative study across mule, equine and equine clone pregnancies regarding the determination of the day of birth

Monitoring equine parturition effectively is essential for preemptive intervention in periparturient issues and ensuring the overall well-being of both mares and foals. However, its implementation in breeding farms is challenging due to variable gestational lengths and nocturnal births. Predictive techniques have the potential to streamline the monitoring process, reduce labor intensity, and minimize costs. Research on foaling prediction in mares carrying mule or equine clone fetuses is scarce. Therefore, this study aimed to comparatively analyze foaling prediction parameters in mares pregnant with mule, equine, or equine clone fetus. The study included vulvar relaxation, sacroiliac ligament tension, pH, BRIX index, and concentrations of calcium, phosphorus, magnesium, sodium, and potassium in prepartum mammary secretions. Sixty pregnant mares were used for this study and grouped as follows: 25 mares with mule fetuses (MF), 20 with equine clone fetuses (CF), and 15 with equine control fetuses (EF). Results showed significant differences in vulvar relaxation and sacroiliac ligament tension only in MF group (p < 0.05) on the day of parturition compared to the other days evaluated, different from the other groups. Levels of pH notably decreased on parturition day (mean 5.7 ± 0.04, p < 0.0001), with lower values in MF (6.05 ± 0.02) and CF (6.08 ± 0.04) compared to EF (6.26 ± 0.04) (p < 0.03). The BRIX index showed variation across mares and was not a good parameter for foaling prediction. Electrolytes correlated positively with impending parturition, showing no significant differences among groups. The MF and CF groups exhibited a substantial increase (102.13 % and 110.66 %, respectively) in mean calcium concentrations on the day before foaling, unlike EF (38.29 %). In conclusion, the pH values were different in mammary secretions between mares carrying mule and clone fetuses, in contrast to equine control fetuses. Nevertheless, there was a trend of decreasing pH values closer to parturition in all groups. Conversely, the BRIX index serves as a valuable indicator of colostrum quality yet does not offer insights into the proximity of parturition. While electrolyte concentrations did not reveal significant differences among groups, it is worth noting that the evaluation of phosphorus emerges as a new parameter to explore in mares nearing parturition, since it obtained a pattern similar to calcium.

Purinergic agonists increase [Ca2+]i in rat conjunctival goblet cells through ryanodine receptor type 3.

ATP and benzoylbenzoyl-ATP (BzATP) increase free cytosolic Ca2+ concentration ([Ca2+]i) in conjunctival goblet cells (CGCs) resulting in mucin secretion. The purpose of this study was to investigate the source of the Ca2+i mobilized by ATP and BzATP. First-passage cultured rat CGCs were incubated with Fura-2/AM, and [Ca2+]i was measured under several conditions with ATP and BzATP stimulation. The following conditions were used: 1) preincubation with the Ca2+ chelator EGTA, 2) preincubation with the SERCA inhibitor thapsigargin (10-6 M), which depletes ER Ca2+ stores, 3) preincubation with phospholipase C (PLC) or protein kinase A (PKA) inhibitor, or 4) preincubation with the voltage-gated calcium channel antagonist nifedipine (10-5 M) and the ryanodine receptor (RyR) antagonist dantrolene (10-5 M). Immunofluorescence microscopy (IF) and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to investigate RyR presence in rat and human CGCs. ATP-stimulated peak [Ca2+]i was significantly lower after chelating Ca2+i with 2 mM EGTA in Ca2+-free buffer. The peak [Ca2+]i increase in CGCs preincubated with thapsigargin, the PKA inhibitor H89, nifedipine, and dantrolene, but not the PLC inhibitor, was reduced for ATP at 10-5 M and BzATP at 10-4 M. Incubating CGCs with dantrolene alone decreased [Ca2+]i and induced CGC cell death at a high concentration. RyR3 was detected in rat and human CGCs with IF and RT-qPCR. We conclude that ATP- and BzATP-induced Ca2+i increases originate from the ER and that RyR3 may be an essential regulator of CGC [Ca2+]i. This study contributes to the understanding of diseases arising from defective Ca2+ signaling in nonexcitable cells.NEW & NOTEWORTHY ATP and benzoylbenzoyl-ATP (BzATP) induce mucin secretion through an increase in free cytosolic calcium concentration ([Ca2+]i) in conjunctival goblet cells (CGCs). The mechanisms through which ATP and BzATP increase [Ca2+]i in CGCs are unclear. Ryanodine receptors (RyRs) are fundamental in [Ca2+]i regulation in excitable cells. Herein, we find that ATP and BzATP increase [Ca2+]i through the activation of protein kinase A, voltage-gated calcium channels, and RyRs, and that RyRs are crucial for nonexcitable CGCs' Ca2+i homeostasis.

OsLdh7, a rice lactate dehydrogenase, confers stress resilience in rice under cadmium stress through NAD+/NADH regulation

Lactate dehydrogenase (Ldh, EC 1.1.1.27), an oxidoreductase enzyme catalyses the interconversion of pyruvate to L-lactate and vice-versa with concomitant oxidation and reduction of NADH and NAD+. The enzyme functions as a ROS sensor and mitigates stress response by maintaining NAD+/NADH homeostasis. In this study, we delineated the role of the Ldh enzyme in imparting cadmium stress tolerance in rice. Previously, we identified a putatively active Ldh in rice (OsLdh7) through insilico modelling. Biochemical characterization of the OsLdh7 enzyme revealed it to be optimally active at pH 6.6 in the forward direction and pH 9 in the reverse direction. Overexpression of OsLdh7 in rice cv. IR64, increased tolerance of the transgenic lines to cadmium stress compared to the wild type (WT) at both seedling and reproductive stages. The transgenic lines showed increased enzyme activity in the reverse direction under cadmium stress, attributed to elevated cytosolic pH resulting from increased calcium concentration. This increased NADH content is highly essential for functioning of the ROS scavenging enzymes, RbohD and MPK6. qPCR analysis revealed that the overexpression lines had increased transcript abundance of these genes indicating an effective ROS scavenging mechanism. Additionally, the overexpression lines showed an efficient cadmium sequestration mechanism compared to the WT by increasing the transcript levels of the vacuolar transporters of cadmium as well as total phytochelatin content. Thus, our findings indicated OsLdh7 imparts cadmium stress tolerance in rice through a two-pronged approach by mitigating ROS and sequestering cadmium ions, highlighting its potential for crop improvement programs.

Investigation of the surface charge behaviour of ettringite: Influence of pH, calcium, and sulphate ions

Ettringite is an important mineral that contributes to the overall performance of cementitious materials. Knowledge of the surface charge behaviour of a solid is necessary for a mechanistic description of surface processes such as adsorption or particle-particle interactions. The objective of this study was to develop a model capable of reproducing ettringite surface charge as a function of calcium, sulphate, and pH.Ettringite was synthesised and characterised using different analytical, microscopic, and spectroscopic techniques with the help of density functional theory. Electrophoretic mobility was measured using laser Doppler electrophoresis in alkaline waters representative of the cementitious environment.The behaviour of the ettringite surface charge was shown to be quite complex as sulphate and calcium acted in a competitive manner on the overall charge. The ζ-potential increases when the calcium content increases, whereas it decreases when sulphate increases. This is due to the possible adsorption of these ions at the surface, and the extent of the effect depends on the relative concentrations of Ca and SO42−.An electrostatic double layer model (DLM) was used to calculate the surface potential, considering the adsorption of both calcium and sulphate, as possible ions determining the potential (IDP), and formation of different complexes with ettringite surface functional groups (SOH). The variations of the ζ-potential could be satisfactorily predicted under the different chemical conditions of interest in a cementitious environment.