Significant Increase In Ca2 Research Articles

Daily versus fortnightly oral vitamin D3 in treatment of symptomatic vitamin D deficiency in children aged 1-10 years: An open labelled randomized controlled trial.

Compare the efficacy and safety of daily versus fortnightly oral vitamin D3 in treating symptomatic vitamin D deficiency in children aged 1-10 years. Open labelled randomized controlled trial. Eighty children with symptomatic vitamin D deficiency were randomized into group daily (D) and group bolus (B) [40 in each group] to receive oral vitamin D3, 4000 IU daily or 60,000 IU fortnightly for 12 weeks respectively. Both groups received daily oral calcium of 500 mg/day. Serum calcium (Ca), phosphate (P), alkaline phosphatase (ALP), 25-hydroxy cholecalciferol (25(OH)D), parathyroid hormone (PTH) levels, urine calcium: creatinine ratio and radiological score were assessed at baseline, 4 weeks and 12 weeks. At the end of 12 weeks, 74 children were available for evaluation of the efficacy and safety of both regimens. Both regimens led to a significant increase in Ca and P levels and a fall in ALP and PTH levels from baseline to 4 and 12 weeks of therapy, with no intergroup difference. At 4- and 12-week assessments, all children in both treatment arms achieved 25(OH)D level in sufficiency range,with no significant difference in their geometric mean. Both regimens were associated with asymptomatic transient hypercalcemia [group D-51.4% vs. group B-34.3%; p-0.14] and hypercalciuria (5.7%) in group D that resolved spontaneously on follow-up. Daily and fortnightly oral vitamin D3 in similar cumulative doses are efficacious for treating symptomatic vitamin D deficiency in children (1-10 years). Treated children should be monitored for serum 25(OH)D, Ca and urinary calcium creatinine ratio.

Ion migration effects during hydro-fracturing of deep high salinity coal seam

Hydraulic fracturing enables effective exploitation of deep coalbed methane. During the hydraulic fracturing process, high salinity flowback fluid is generated, and this poses a significant challenge for water treatment. Therefore, we investigate the effect of hydraulic fracturing on ion migration in deep coal seams and its underlying mechanisms. In this study, nuclear magnetic resonance, inductively coupled plasma mass spectrometry, scanning electron microscopy, and energy dispersive x-ray spectroscopy were utilized to systematically study the diffusion behavior of ions and its correlation with water imbibition. Our results show that imbibition equilibrium was reached before ion diffusion finished. Ion diffusion displays three linear stages followed by a plateau part, and the second segment is the fastest one. The water–coal interactions result in the diffusion of ions into solution, with the most significant increases in Ca2+, Mg2+, Na+, K+, Li+, Cu2+, V5+, Hg2+, Pb2+, B3+, Mo6+, Cr3+, Sn4+, Cd2+, Cs+, Sr2+, and Ba2+. The dissolution of calcite, sodium feldspar, and kaolinite are the main contributions for ion migration. In addition, these reactions not only cause the release of ions into the solution but also lead to the formation of secondary pore-fractures and secondary precipitation. The results of this work help to understand better the ion migration induced by the water–coal interaction and to evaluate the fluid properties in deep coal formations.

Unraveling the Impact of Ethylenediaminetetraacetic Acid Chelating Agents on the Oil Recovery Processes: An Insight into Its Role in Fluid-Fluid and Rock-Fluid Interactions.

In recent years, chelating agents have garnered increasing attention due to their unique capabilities in addressing challenges associated with chemically enhanced oil recovery materials. Most previous studies have primarily focused on examining the influence of chelating agents on rock-fluid interactions. However, their effects on fluid-fluid interactions, specifically on interfacial tension (IFT) characteristics under various conditions, remain relatively unknown. This study investigates the effect of crucial reservoir parameters on the performance of ethylenediaminetetraacetic acid (EDTA) chelating agents in the IFT between crude oil and brine. Furthermore, the study evaluated the impact of varying concentrations of this agent on rock wettability alteration, zeta potential, and spontaneous imbibition. The results illustrated that introducing EDTA at high concentration into seawater (SW) solution reduced the IFT by 85%. Additionally, while higher pH levels contributed to IFT reduction due to increased hydroxyl ions, excessive salinity levels resulted in elevated IFT. Raising the temperature from 30 to 75 °C further decreased the IFT, changing the IFT for optimal EDTA concentration from 20.43 to 2.56 mN/m (∼88% reduction). The changes in zeta potential and contact angle measurements indicated that solutions of 5 and 7 wt % EDTA shifted rock wettability from oil-wet to strongly water-wet, resulting in the wettability alteration index of 1.01 and 1.02, respectively. Inductively coupled plasma analysis, on the other hand, revealed substantial chelation of metal ions from both the solution and rock when EDTA was added to the rock/SW system. This resulted in a significant increase in Ca2+ ions and a decrease in Mg2+ ions, attributed to the multi-ion exchange phenomenon.

PINK1 restrains periodontitis-induced bone loss by preventing osteoclast mitophagy impairment

The oral colonization of periodontal pathogens onto gingival tissues establishes hypoxic microenvironment, often disrupting periodontal homeostasis in conjunction with oxidative stress. The association between reactive oxygen species (ROS) and osteolytic periodontitis have been suggested by recent studies. PTEN-induced kinase 1 (PINK1), a mitochondrial serine/threonine kinase, is an essential protein for mitochondrial quality control as it protects cells from oxidative stress by promoting degradation of damaged mitochondria through mitophagy. However, the pathophysiological roles of PINK1 in osteoclast-mediated bone loss have not been explored. Here we aimed to determine whether PINK1 plays a role in the regulation of osteoclastogenesis and alveolar bone resorption associated with periodontitis. C57BL/6 wild type (WT) and Pink1 knockout (KO) mice were subjected to ligature-induced periodontitis (LIP), and alveolar bones were evaluated by μCT-analysis and tartrate-resistant acid phosphatase (TRAP) staining. The μCT-analysis showed that bone volume fraction and travecular thickness were lower in Pink1 KO compared to WT mice. The number of TRAP-positive osteoclasts was markedly increased in the periodontal tissues of Pink1 KO mice with LIP. The genetic silencing or deletion of Pink1 promoted excessive osteoclast differentiation and bone resorption in vitro, as respectively indicated by TRAP staining and resorption pits on dentin slices. PINK1 deficiency led to mitochondrial instabilities as indicated by confocal microscopy of mitochondrial ROS, mitochondrial oxygen consumption rate (OCR) analysis, and transmission electron microscopy (TEM). Consequently, a significant increase in Ca2+-nuclear factor of activated T cells 1 (NFATc1) signaling was also found. On the other hand, restoration of mitophagy and autophagy by spermidine (SPD) treatment and the resolution of oxidative stress by N-acetyl-l-cysteine (NAC) treatment protected PINK1 deficiency-induced excessive generation of osteoclasts. Taken together, our findings demonstrate that PINK1 is essential for maintaining mitochondrial homeostasis during osteoclast differentiation. Therefore, targeting PINK1 may provide a novel therapeutic strategy for severe periodontitis with fulminant osteolysis.

Enhanced Release of Calcium Ions from Hydroxyapatite Nanoparticles with an Increase in Their Specific Surface Area.

Synthetic calcium phosphates, e.g., hydroxyapatite (HAP) and tricalcium phosphate (TCP), are the most commonly used bone-graft materials due to their high chemical similarity to the natural hydroxyapatite-the inorganic component of bones. Calcium in the form of a free ion or bound complexes plays a key role in many biological functions, including bone regeneration. This paper explores the possibility of increasing the Ca2+-ion release from HAP nanoparticles (NPs) by reducing their size. Hydroxyapatite nanoparticles were obtained through microwave hydrothermal synthesis. Particles with a specific surface area ranging from 51 m2/g to 240 m2/g and with sizes of 39, 29, 19, 11, 10, and 9 nm were used in the experiment. The structure of the nanomaterial was also studied by means of helium pycnometry, X-ray diffraction (XRD), and transmission-electron microscopy (TEM). The calcium-ion release into phosphate-buffered saline (PBS) was studied. The highest release of Ca2+ ions, i.e., 18 mg/L, was observed in HAP with a specific surface area 240 m2/g and an average nanoparticle size of 9 nm. A significant increase in Ca2+-ion release was also observed with specific surface areas of 183 m2/g and above, and with nanoparticle sizes of 11 nm and below. No substantial size dependence was observed for the larger particle sizes.

Sarcospan Deficiency Increases Oxidative Stress and Arrhythmias in Hearts after Acute Ischemia-Reperfusion Injury.

The protein sarcospan (SSPN) is an integral member of the dystrophin-glycoprotein complex (DGC) and has been shown to be important in the heart during the development and the response to acute stress. In this study, we investigated the role of SSPN in the cardiac response to acute ischemia-reperfusion (IR) injury in SSPN-deficient (SSPN-/-) mice. First, the hemodynamic response of SSPN-/- mice was tested and was similar to SSPN+/+ (wild-type) mice after isoproterenol injection. Using the in situ Langendorff perfusion method, SSPN-/- hearts were subjected to IR injury and found to have increased infarct size and arrhythmia susceptibility compared to SSPN+/+. Ca2+ handling was assessed in single cardiomyocytes and diastolic Ca2+ levels were increased after acute β-AR stimulation in SSPN+/+ but not SSPN-/-. It was also found that SSPN-/- cardiomyocytes had reduced Ca2+ SR content compared to SSPN+/+ but similar SR Ca2+ release. Next, we used qRT-PCR to examine gene expression of Ca2+ handling proteins after acute IR injury. SSPN-/- hearts showed a significant decrease in L-type Ca2+ channels and a significant increase in Ca2+ release channel (RyR2) expression. Interestingly, under oxidizing conditions reminiscent of IR, SSPN-/- cardiomyocytes, had increased H2O2-induced reactive oxygen species production compared to SSPN+/+. Examination of oxidative stress proteins indicated that NADPH oxidase 4 and oxidized CAMKII were increased in SSPN-/- hearts after acute IR injury. These results suggest that increased arrhythmia susceptibility in SSPN-/- hearts post-IR injury may arise from alterations in Ca2+ handling and a reduced capacity to regulate oxidative stress pathways.

Functional and developmental changes in the inner hair cell ribbon synapses caused by Myosin VI knockout and deafness-inducing point mutation

Hearing loss is one of the most common neurosensory disorders in humans, and above half of hearing loss is caused by gene mutations. Among more than 100 genes that cause non-syndromic hearing loss, myosin VI (MYO6) is typical in terms of the complexity of underlying mechanisms, which are not well understood. In this study, we used both knock-out (Myo6−/−) and point mutation (Myo6C442Y) mice as animal models, performed whole-cell patch-clamp recording and capacitance measurement in the inner hair cells (IHCs) in the cochlea, and sought to reveal potential functional and developmental changes in their ribbon synapses. In Myo6−/− cochleae of both before (P8-10) and after hearing onset (P18-20), exocytosis from IHCs, measured in whole-cell capacitance change (ΔCm), was significantly reduced, Ca2+ current amplitude (ICa) was unchanged, but Ca2+ voltage dependency was differently altered, causing significant increase in Ca2+ influx in mature IHCs but not in immature IHCs. In immature IHCs of Myo6C442Y/C442Y cochleae, neither ΔCm nor ICa was altered, but both were reduced in mature IHCs of the same animal model. Furthermore, while the reduction of exocytosis was caused by a combination of the slower rate of depleting readily releasable (RRP) pool of synaptic vesicles and slower sustained release rate (SRR) in Myo6−/− immature IHCs, it was likely due to smaller RRP and slower SRR in mature IHCs of both animal models. These results expand our understanding of the mechanisms of deafness caused by MYO6 mutations, and provide a solid theoretical and scientific basis for the diagnosis and treatment of deafness.

Daily vs. monthly oral vitamin D3 for treatment of symptomatic vitamin D deficiency in infants: a randomized controlled trial.

Compare the efficacy and safety of daily vs. monthly oral vitamin D3 in treating symptomatic vitamin D deficiency in infants. 90 infants with symptomatic vitamin D deficiency were randomized into Daily (D) [46 infants] and Bolus (B) [44 infants] groups to receive oral vitamin D3, daily (2000 IU/day) and bolus (60,000 IU/month) for three months respectively. Both groups received daily oral calcium @50 mg/kg/day. Serum calcium (Ca), phosphate (P), alkaline phosphatase (ALP), 25-hydroxy cholecalciferol [25(OH)D], parathyroid hormone (PTH) levels, urine calcium: creatinine ratio and radiological score were assessed at baseline, 4 and 12weeks. At the end of 12weeks, 78 infants were available for evaluation of efficacy and safety of both regimens. Both regimens led to a statistically significant increase in Ca and P levels and fall in ALP and PTH levels from baseline to 4 and 12weeks of therapy, with no inter-group difference. Infants in group D had statistically significant higher mean 25(OH)D levels as compared to group B at 4weeks (group D 130.89 ± 43.43 nmol/L, group B- 108.25 ± 32.40 nmol/L; p- 0.012) and 12weeks (group D- 193.69±32.47 nmol/L, group B- 153.85 ± 33.60 nmol/L; p<0.001). Eight infants [group D- 6/41 (14.6 %); group B- 2/37 (5.4 %), p=0.268] developed mild asymptomatic hypercalcemia without hypercalciuria at 12weeks that corrected spontaneously within a week. Both daily and monthly oral vitamin D3 in equivalent doses are efficacious and safe for treating symptomatic vitamin D deficiency in infants.

Cadmium pollution leads to selectivity loss of glutamate receptor channels for permeation of Ca2+/Mn2+/Fe2+/Zn2+ over Cd2+ in rice plant

The selective permeation of glutamate receptor channels (GLRs) for essential and toxic elements in plant cells is poorly understood. The present study found that the ratios between cadmium (Cd) and 7 essential elements (i.e., K, Mg, Ca, Mn, Fe, Zn and Cu) in grains and vegetative organs increased significantly with the increase of soil Cd levels. Accumulation of Cd resulted in the significant increase of Ca, Mn, Fe and Zn content and the expression levels of Ca channel genes (OsCNGC1,2 and OsOSCA1.1,2.4), while remarkable reduction of glutamate content and expression levels of GLR3.1–3.4 in rice. When planted in the same Cd-polluted soil, mutant fc8 displayed significantly higher content of Ca, Fe, Zn and expression levels of GLR3.1–3.4 than its wild type NPB. On the contrary, the ratios between Cd and essential elements in fc8 were significantly lower than that in NPB. These results indicate that Cd pollution may damage the structural integrity of GLRs by inhibiting glutamate synthesis and expression levels of GLR3.1–3.4, which leads to the increase of ion influx but the decrease of preferential selectivity for Ca2+/ Mn2+/ Fe2+/ Zn2+ over Cd2+ through GLRs in rice cells.

Liming in soils with plinthic materials of the Brazilian Savanna: potentials and limitations

The expansion of agriculture has been taking place in marginal soils with low productive potential, such as Plinthosols. The liming can increase the economic and environmental sustainability of agriculture. However, there are no studies on the dissolution or recommendation of limestone for Plinthosols. The objective was to evaluate the effect of limestone doses on the chemical attributes of three soils with different gravel contents (ironstone concretions). The soils were collected (0-20 cm layer) in native areas of the central region of the Brazilian Savanna. They were classified as Red-Yellow Latosol (RYO) and two Concretionary Pétric Plinthosol (with 29% [CPP-29] and 72.8% [CPP-72] of soil volume with gravel). A factorial scheme (3x6) with the three soils (RYO, CPP-29, and CPP-72), six limestone doses, and four replications. The evolution of pH was verified at 10, 20, 30, and 40 days after the beginning of incubation (DAI), and determined the chemical attributes (Al, H+Al, Ca, Mg, BS, V%, P, and K) at 40 DAI. The doses to reach pH 6 were 1.4 t ha-1 for RYO, 3.9 t ha-1 for CPP-29, and 2.7 t ha-1 for CPP-72. Al3+ neutralization was 100% with doses above 3.5, 2.5 and 0.5 t ha-1 for CPP-29, CPP-72, RYO. There was a significant increase in Ca and Mg contents in all soils. However, the Soil CPP-72 did not reach a critical level for Ca (&gt;2.41 cmolc dm-3) and Mg (&gt;0.91 cmolc dm-3) for Plinthosols with higher plinthite content. Thus, we recommend using agricultural practices that increase the capacity of the soil to retain and recycle nutrients.

Hypoxia Drives Centrosome Amplification in Cancer Cells via HIF1α-dependent Induction of Polo-Like Kinase 4.

Hypoxia drives CA in cancer cells by regulating expression of PLK4, uncovering a novel HIF1α/PLK4 axis.

What are the key mechanisms that alter the morphology of stigmatic papillae in Arabidopsis thaliana?

ABSTRACT Pollination is one of the critical processes that determines crop yield and quality. Thus, it is an urgent need to elucidate the mechanisms underlying pollination. Our previous research has revealed a novel phenomenon that pollen attachment to stigma caused stigma shrinkage, whereas failure of pollen attachment to stigma due to the environmental stress induced elongation of stigmatic papillae. However, little is known about the mechanisms of these morphological alterations in stigmatic papillae. Since the RLK-ROPGEF-ROP network is a common mechanism for the elongation of pollen tubes and root hairs, this network may be also involved in the elongation of papillae in the stigma. In this review, we will discuss the known mechanisms regulating pollen tube growth and root hair elongation and attempt to propose an elongation mechanism of stigmatic papillae. In addition, we will suggest that the degradation of F-actin by a significant increase in Ca2+ induced by the components of pollen coat might be a putative molecular mechanism of stigmatic papillae shrinkage during pollen adhesion.

In situ determination of guard cell ion flux underpins the mechanism of ABA-mediated stomatal closure in barley plants exposed to PEG-induced drought stress

ABA regulates stomatal movement by affecting ion transport in guard cells; yet in situ measurement of ABA-mediated dynamics of guard cell ion transport and the involvement of other phytohormones in regulating stomatal aperture under drought stress are still lacking. In this study, hydroponically grown plants of wild type barley Steptoe (WT) and its correspondent ABA-deficient barley mutant Az34 were treated with 10% polyethylene glycol (PEG) 6000 for 0, 2, 4, and 24 h or 9 d to mimic short- and long-term drought stress. The K+, H+ and Ca2+ fluxes in the guard cell were monitored in situ by noninvasive micro-test technology. Upon 10% PEG treatment, leaf ABA concentration ([ABA]leaf) of both barley genotypes increased dramatically after 2 h and reached the highest level after the 24 h. Compared to the control, a significant increase in Ca2+ influx in both genotypes was observed after 2 h exposure to PEG, and reached the largest value after 4 h in WT. The increase of [ABA]leaf coincided with the increase of K+ efflux and Ca2+ influx and the decrease of stomatal conductance in WT under short-term drought stress, though the concentrations of IAA, GA3 and ZR in WT were all increased at 4 h. K+ efflux of guard cells was significantly greater in WT than in Az34 at 24 h after PEG treatment. The results elucidate the role of ABA in mediating ion transports in guard cells, hereby regulating the stomatal movement in barley exposed to drought stress.

Functional and Quality Characteristics of Ginger, Pineapple, and Turmeric Juice Mix as Influenced by Blend Variations.

In this current work, the functional and quality characteristics of ginger, pineapple, and turmeric juice mix as influenced by blend variations were investigated. Specifically, the blends had constant ginger amounts, decreased pineapple, and increased turmeric proportionally. Additionally, the functional properties involved physicochemical (pH, soluble solids (SS), total titratable acidity (TA) and viscosity), proximate (moisture, protein, fat and ash), minerals (Ca, and Mg) and vitamin C and β-carotene analyses, whereas quality properties involved microbiological and sensory analyses. The results showed that as quantities of pineapple and turmeric respectively decreased and increased, there was significant increases in Ca, Mg, vitamin C, and β-carotene contents (p < 0.05). Across the blends, the degree of significant differences (p < 0.05) in the protein, fat, and ash seemed more compared to those of moisture contents. Despite the increases in pH and viscosity, and decreases in SS and TA, the increases in turmeric potentially reinforced by ginger most likely decreased the bacterial/fungi counts, as well as inhibition zones. Increasing and decreasing the respective amounts of turmeric and pineapple might not necessarily make the blends more acceptable, given the decreases in appearance, taste, aroma, and mouthfeel scores.

Requirement of the Ca2+ channel β2 subunit for sympathetic PKA phosphorylation

Facilitation of cardiac function in response to signals from the sympathetic nervous system is initiated by the phosphorylation of L-type voltage-dependent Ca2+ channels (VDCCs) by protein kinase A (PKA), which in turn is activated by β-adrenoceptors. Among the five subunits (α1, β, α2/δ, and γ) of VDCCs, the α1 subunit and the family of β subunits are substrates for PKA-catalyzed phosphorylation; however, the subunit responsible for β-adrenergic augmentation of Ca2+ channel function has yet to be specifically identified. Here we show that the VDCC β2 subunit is required for PKA phosphorylation upon sympathetic acceleration. In mice with β2 subunit-null mutations, cardiac muscle contraction in response to isoproterenol was reduced and there was no significant increase in Ca2+ channel currents upon PKA-dependent phosphorylation. These findings indicate that within the sympathetic nervous system the β2 subunit of VDCCs is required for physiological PKA-dependent channel phosphorylation.

Abstract 16594: Disruption of Caveolae-Confined Phosphorylation of Ryanodine Receptors Promotes Ca 2+ Handling Abnormalities and Arrhythmogenesis in Mouse Atrial Myocytes

Rationale: Chronic atrial fibrillation has been linked to ectopic triggered activity driven by delayed afterdepolarizations in response to sarcoplasmic reticulum Ca 2+ leak from certain areas in atria. These activities were associated with hyperphosphorylated ryanodine receptors (RyRs), while the underlying mechanisms remain uncertain. Here, we hypothesized that mouse atria have areas with lower transversal-axial tubule system (TATS) organization, where phosphorylation of RyRs is mainly confines by caveolae nanodomains and might be firstly disturbed in disease conditions. Methods and results: In wild type (WT) mouse intact atria stained with RH-237, we found that myocytes located in the intercaval region (ICR, between the superior vena cava and atrioventricular junction and between the crista terminalis and interatrial septum) have a significantly less density of TATS than right atrial appendage (RAA) myocytes: 5.7±0.4% in ICR vs. 13.4±0.9% in RAA, P&lt;0.01. Also an elevated frequency of spontaneous Ca 2+ sparks was observed in myocytes isolated from ICR vs. RAA (12.5±2.6 vs. 1.5±0.3 sparks/μm/s, P&lt;0.01). ICR myocytes isolated from mice with a cardiac-specific knockout of the main structural protein of caveolae, caveolin-3, showed significant increase of Ca 2+ sparks frequency as compared to WT (27.3±4.1 sparks/μm/s, P&lt;0.01). Immunofluorescence staining of RyRs, phosphorylated at protein kinase A/ Ca 2+ /calmodulin-dependent protein kinase-II phosphorylation sites: Ser 2808 -RyR and Ser 2814 -RyR, showed predominant subsarcolemmal localization, with a high co-localization with caveolin-3, in ICR and RAA cells. Myocytes isolated from caveolin-3 knockout mice showed extension of both Ser 2808- RyR and Ser 2808- RyR to whole-cell wide striated pattern in ICR, but not RAA. This redistribution was associated with development of delayed afterdepolarizations in ICR but not RAA cells. Conclusions: Our findings demonstrate that in ICR in mouse atria, caveolae form functional, spatially-confined cAMP nanodomains and control localized RyR phosphorylation. Disruption of caveolae structures, seen in various pathologies, may lead to hyperphosphorylation of RyRs promoting Ca 2+ handling abnormalities and arrhythmogenic triggered activity.

Seizures elevate gliovascular unit Ca2+ and cause sustained vasoconstriction.

Seizures can result in a severe hypoperfusion/hypoxic attack that causes postictal memory and behavioral impairments. However, neither postictal changes to microvasculature nor Ca2+ changes in key cell types controlling blood perfusion have been visualized in vivo, leaving essential components of the underlying cellular mechanisms unclear. Here, we use 2-photon microvascular and Ca2+ imaging in awake mice to show that seizures result in a robust vasoconstriction of cortical penetrating arterioles, which temporally mirrors the prolonged postictal hypoxia. The vascular effect was dependent on cyclooxygenase 2, as pretreatment with ibuprofen prevented postictal vasoconstriction. Moreover, seizures caused a rapid elevation in astrocyte endfoot Ca2+ that was confined to the seizure period, and vascular smooth muscle cells displayed a significant increase in Ca2+ both during and following seizures, lasting up to 75 minutes. Our data show enduring postictal vasoconstriction and temporal activities of 2 cell types within the neurovascular unit that are associated with seizure-induced hypoperfusion/hypoxia. These findings support prevention of this event may be a novel and tractable treatment strategy in patients with epilepsy who experience extended postseizure impairments.

Concentrations of toxic metals and essential elements in raw cow milk from areas with potentially undisturbed and highly disturbed environment in Slovakia.

Dietary composition and husbandry practices largely determine the essential trace element status and the toxic metal exposure of livestock and consequently their concentrations in animal products. The main objective of this study was to determine the real contamination of selected areas of Slovakia compared with existing Environmental regionalization of the Slovak Republic (SR) created by the Ministry of the Environment SR. Another aim of this study was to determine the content of essential and toxic metals in feed and milk of dairy cows on selected farms in Slovakia referred to the suitability of the use of milk from these areas to other food processing. This article deals with the analysis of the content of selected elements in feed and milk of dairy cows in the area of Novoť (Northern Slovakia; area with undisturbed environment) and Čečejovce (Eastern Slovakia; highly disturbed environment). Eleven elements have been analyzed (essential elements: calcium, zinc, magnesium, selenium, iron, copper; toxic elements: arsenic, cadmium, mercury, lead, nickel). Samples of feed and milk were collected five times during the spring season and five times during the autumn season in 2016. Analysis of samples was performed in Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by atomic absorption spectroscopy and atomic emission spectrometry. The obtained values of the individual elements in the feed and milk were evaluated by Student's t test. Significantly higher contents of essential elements Ca, Zn, Fe, Mg, and Cu were found in the feed of dairy cows in Čečejovce (P < 0.001). Significantly higher (P < 0.001) As and Ni content in feed in Čečejovce in autumn season was also recorded. However, the content of these elements in feed did not affect their milk content. The content of Ca, Zn, and Mg in milk was significantly (P < 0.001) higher in Novoť in both investigated seasons. Some essential elements and toxic elements in feed and milk were below the LOQ (limit of quantification). Reduced content of Ca and Zn in milk in both farms compared with optimal limits, decreased Ca and Mg content in feed in Novoť, and a significant increase of Ca and Mg in feed in Čečejovce in autumn season were found. It can be concluded, due to the low content of toxic elements on these farms, that the use of milk of dairy cows from these areas for direct use or for dairy product processing is appropriate and poses no health risk to the consumers.

Microscopic Mechanism of Cement Improving the Strength of Lime‐Fly Ash‐Stabilized Yellow River Alluvial Silt

Silt is a kind of soil with poor engineering performance. Lime‐fly ash‐ (LF‐) stabilized silt has the problem of low early strength. In this study, it is aimed to investigate the effect of cement on improving the strength of LF‐stabilized silt and reveal the microscopic mechanism. A fixed percentage of LF (18%) plus different percentages of cement (0%, 2%, 4%, and 6%) were mixed with Yellow River alluvial silt (YRAS). Soil samples for tests were artificially made by compaction in the laboratory. Unconfined compressive strength (UCS) tests were performed on soil samples cured for 7 d, 28 d, 60 d, and 90 d. Scanning electron microscope (SEM) tests, energy dispersive X‐ray spectroscopy (EDS) tests, and mercury intrusion porosimetry (MIP) tests were performed on soil samples cured for 7 d and 28 d. UCS results showed that the early strength of LF‐stabilized YRAS developed significantly after adding cement. UCS also increased with the increase in cement content and curing time. SEM results revealed the differences in microstructure of LF‐stabilized YRAS before and after adding cement. Before adding cement, the main microstructure characteristics included small soil particles, large number of pores, and loose particle arrangement. After adding cement, the main microstructure characteristics included large bonded particles, small number of pores, and dense particle arrangement. The EDS results showed that, after curing for 28 d, the elements of gels in stabilized YRAS had changed, mainly including appearance of C and a significant increase of Ca. MIP results showed that the pores with a size of 1 μm∼10 μm accounted for the largest proportion in stabilized YRAS. The product (mainly C‐S‐H) of cement hydration mainly filled the pores with a size larger than 10 μm at the early stage. Combining strength results and microresults, the micromechanism of cement improving the strength of LF‐stabilized YRAS was discussed.

Ca2+ Influx Channel Inhibitor SARAF Protects Mice From Acute Pancreatitis

Pancreatitis is characterized by increased influx of Ca2+ into acinar cells, by unknown mechanisms. Inhibitors of Ca2+ influx channels could be effective in treating acute pancreatitis, but these have deleterious side effects that can result in death. We investigated the expression patterns and functions of acinar cell Ca2+ channels and factors that regulate them during development of acute pancreatitis, along with changes in the channel inactivator store-operated calcium entry-associated regulatory factor (SARAF). We investigated whether SARAF is a target for treatment of acute pancreatitis and its status in human with pancreatitis. We generated mice that expressed SARAF tagged with hemagglutinin, using CRISPR/Cas9 gene editing, and isolated acinar cells. We also performed studies with Saraf-/- mice, Sarafzf/zf mice, mice without disruption of Saraf (control mice), and mice that overexpress fluorescently labeled SARAF in acinar cells. We analyzed interactions between stromal interaction molecule 1 (STIM1) and SARAF in HEK cells stimulated with carbachol using fluorescence resonance energy transfer microscopy and immunoprecipitation. Mice were given injections of caerulein or L-arginine to induce pancreatitis. Pancreatic tissues and blood samples were collected and levels of serum amylase, trypsin, tissue damage, inflammatory mediators, and inflammatory cells were measured. We performed quantitative polymerase chain reaction analyses of pancreatic tissues from 6 organ donors without pancreatic disease (controls) and 8 patients with alcohol-associated pancreatitis. Pancreatic levels of Ca2+ influx channels or STIM1 did not differ significantly between acinar cells from mice with vs. without pancreatitis. By contrast, pancreatic levels of Saraf messenger RNA and SARAF protein initially markedly increased but then decreased during cell stimulation or injection of mice with caerulein, resulting in excessive Ca2+ influx. STIM1 interacted stably with SARAF following stimulation of HEK or mouse acinar cells with physiologic levels of carbachol, but only transiently following stimulation with pathologic levels of carbachol, leading to excessive Ca2+ influx. We observed reduced levels of SARAF messenger RNA in pancreatic tissues from patients with pancreatitis, compared with controls. SARAF knockout mice developed more severe pancreatitis than control mice after administration of caerulein or L-arginine, and pancreatic acinar cells from these mice had significant increases in Ca2+ influx. Conversely, overexpression of SARAF in acini reduced Ca2+ influx, eliminated inflammation, and reduced severity of acute pancreatitis. In mice with pancreatitis, SARAF initially increases but is then degraded, resulting in excessive, pathological Ca2+ influx by acinar cells. SARAF knockout mice develop more severe pancreatitis than control mice, whereas mice that express SARAF from a transgene in acinar cells develop less-severe pancreatitis. SARAF therefore appears to prevent pancreatic damage during development of acute pancreatitis. Strategies to stabilize or restore SARAF to acinar cells might be developed for treatment of pancreatitis.