Displaying publications 21 - 40 of 843 in total

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  1. Cahyanto A, Rath P, Teo TX, Tong SS, Malhotra R, Cavalcanti BN, et al.
    J Dent Res, 2023 Dec;102(13):1425-1433.
    PMID: 37861249 DOI: 10.1177/00220345231198185
    Calcium silicate (C3S) cements are available in kits that do not account for patients' specific needs or clinicians' preferences regarding setting time, radiopacity, mechanical, and handling properties. Moreover, slight variations in powder components and liquid content affect cement's properties and bioactivity. Unfortunately, it is virtually impossible to optimize several cement properties simultaneously via the traditional "one variable at a time" strategy, as inputs often induce trade-offs in properties (e.g., a higher water-to-powder ratio [W/P] increases flowability but decreases mechanical properties). Herein, we used Taguchi's methods and genetic algorithms (GAs) to simultaneously analyze the effect of multiple inputs (e.g., powder composition, radiopacifier concentration, and W/P) on setting time, pH, flowability, diametral tensile strength, and radiopacity, as well as prescribe recipes to produce cements with predicted properties. The properties of cements designed with GAs were experimentally tested, and the results matched the predictions. Finally, we show that the cements increased the genetic expression of odonto/osteogenic genes, alkaline phosphatase activity, and mineralization potential of dental pulp stem cells. Hence, GAs can produce cements with tailor-made properties and differentiation potential for personalized endodontic treatment.
    Matched MeSH terms: Calcium
  2. Nguyen TH, Mat Daud ZA, Abd Talib R, Mohd R, Poh BK
    Transplant Proc, 2023 Nov;55(9):2176-2182.
    PMID: 37743189 DOI: 10.1016/j.transproceed.2023.08.008
    BACKGROUND: Although metabolic syndrome (MetS) is a significant risk factor, and dietary intake may affect the quality of life (QoL) of kidney transplant recipients (KTRs), the association between them are unclear. This study identified MetS and nutritional factors associated with the QoL of KTRs.

    METHODS: This study reports baseline data from a longitudinal study that was conducted at a hospital in Vietnam. KTRs aged ≥18 years and >3 months post-transplantation were recruited. Assessments included sociodemographic and blood biomarkers. Dietary intake was estimated from 24-hour recalls. A Short Form-36 Health Survey, comprising physical (PCS) and mental component summaries (MCS), was administered to assess QoL. Multivariate linear regression models were performed.

    RESULTS: The study included 106 patients (79 men) with a mean age of 43.2 years (± 11.9). Mean duration after kidney transplantation was 28.5 months (± 14.9). Patients with MetS had 6.43 lower PCS score (P < .05) and 3.20 lower MCS score (P < .05) than their counterparts without MetS. Calcium intake (β = -0.01; 95% CI, -0.03 to 0.00) and inadequate protein (β = -14.8; 95% CI, -23 to -6.65) were negatively associated with PCS score. MCS score was negatively associated with calcium intake (β = -0.02; 95% CI, -0.04 to -0.01) and inadequate protein intake (β = -15.1; 95% CI, -24.3 to -5.86), and positively associated with fat intake (β = 0.43, 95% CI, 0.02-0.85).

    CONCLUSIONS: MetS and poor dietary intake are independently associated with the QoL of KTRs. Nutritional intervention plans developed specifically for the recipients will improve dietary intake, reduce the incidence of MetS, and help enhance QoL.

    Matched MeSH terms: Calcium
  3. Rehman ZU, Rehman MA, Rehman B, Sikiru S, Qureshi S, Ali EM, et al.
    Environ Sci Pollut Res Int, 2023 Nov;30(53):113889-113902.
    PMID: 37858013 DOI: 10.1007/s11356-023-30279-0
    Renewable energy systems are vital for a sustainable future, where solid-state hydrogen storage can play a crucial role. Perovskite hydride materials have attracted the scientific community for hydrogen storage applications. The current work focuses on the theoretical study using density functional theory (DFT) to evaluate the characteristics of MgXH3 (X = Co, Cu, Ni) hydrides. The structural, vibrational, electronic, mechanical, thermodynamic, and hydrogen storage properties of these hydrides were investigated. The equilibrium lattice parameters were calculated using the Birch-Murnaghan equation of state-to-energy volume curves. The elastic constants (Cij) and relevant parameters, such as Born criteria, were calculated to confirm the mechanical stability of the hydrides. The Cauchy pressure (Cp) revealed brittle or ductile behavior. The outcomes of the Pugh ratio, Poisson ratio, and anisotropy were also calculated and discussed. The absence of negative lattice vibrational frequencies in phonon dispersion confirmed the lattice's dynamic stability. The heat capacity curves of thermodynamic properties revealed that hydrides can conduct thermal energy. The metallic character and ample interatomic distances of hydrides were confirmed by the band structure and population analysis, which confirmed that hydrides can conduct electrical energy and adsorb hydrogen. The density of state (DOS) and partial DOS unveiled the role of specific atoms in the DOS of the crystal. The calculated gravimetric hydrogen storage capacity of MgCoH3, MgCuH3, and MgNiH3 hydrides was 3.64, 3.32, and 3.49wt%, respectively. Our results provide a deeper understanding of its potential for hydrogen storage applications through a detailed analysis of MgXH3 (X = Co, Cu, Ni) perovskite hydride material.
    Matched MeSH terms: Calcium Compounds*
  4. Khor ZX, Pua QY, Tai YT
    BMJ Case Rep, 2023 Oct 04;16(10).
    PMID: 37793845 DOI: 10.1136/bcr-2023-257005
    Matched MeSH terms: Calcium
  5. Khoo CS, Shukor MF, Tan JK, Tan MM, Yong LL, Sahibulddin SZ, et al.
    Epilepsy Behav, 2023 Oct;147:109432.
    PMID: 37716324 DOI: 10.1016/j.yebeh.2023.109432
    BACKGROUND: Vitamin D deficiency among adult people with epilepsy (PWE) is scarcely studied, despite its essential role in bone health and maintaining homeostasis. Several studies have studied the relationship between factors related to epilepsy and vitamin D metabolism. We aim to investigate this in our multi-ethnic society.

    METHODS: This was a single-center cross-sectional study. We recruited 159 participants diagnosed with epilepsy on antiseizure medications (ASMs). We included those aged 18 years and above, excluding patients with long-term medical conditions that would affect vitamin D metabolism. Sociodemographic data and details of epilepsy were collated. Venous sampling was performed to analyze the levels of albumin-corrected calcium, phosphate, alkaline phosphatase, and 25-hydroxyvitamin D3 [25(OH)D]. Serum 25(OH)D level is defined as deficient (<20 ng/ml), insufficient (20-29 ng/ml), and sufficient (≥30 ng/ml).

    RESULTS: The study reported that 73 (45.9%) participants had vitamin D deficiency, 38 (23.9%) had vitamin D insufficiency, and 48 (30.2%) patients had sufficient vitamin D levels. The predictors identified were PWE aged 18 to 44 years old (p = 0.001), female gender (OR 3.396, p = 0.002), and ethnicity (p calcium, or the prevalence of vitamin D deficiency.

    CONCLUSION: Vitamin D deficiency among PWE is prevalent in our local population, suggesting that regular screening should be considered for those at risk. Early identification would allow intervention to reduce the risk of future complications.

    Matched MeSH terms: Calcium
  6. Sharaf Aldeen EM, Jalil AA, Mim RS, Hatta AH, Hazril NIH, Chowdhury A, et al.
    Environ Res, 2023 Oct 01;234:116576.
    PMID: 37423362 DOI: 10.1016/j.envres.2023.116576
    Photocatalysis utilizing semiconductors offer a cost-effective and promising solution for the removal of pollutants. MXene and perovskites, which possess desirable properties such as a suitable bandgap, stability, and affordability, have emerged as a highly promising material for photocatalytic activity. However, the efficiency of MXene and perovskites is limited by their fast recombination rates and inadequate light harvesting abilities. Nonetheless, several additional modifications have been shown to enhance their performance, thereby warranting further exploration. This study delves into the fundamental principles of reactive species for MXene-perovskites. Various methods of modification of MXene-perovskite-based photocatalysts, including Schottky junction, Z-scheme and S-scheme are analyzed with regard to their operation, differences, identification techniques and reusability. The assemblance of heterojunctions is demonstrated to enhance photocatalytic activity while also suppressing charge carrier recombination. Furthermore, the separation of photocatalysts through magnetic-based methods is also investigated. Consequently, MXene-perovskite-based photocatalysts are seen as an exciting emerging technology that necessitates further research and development.
    Matched MeSH terms: Calcium Compounds
  7. Smran A, Abdullah M, Ahmad NA, Alrahlah A, Al-Maflehi N, Samran A
    BMC Oral Health, 2023 Sep 18;23(1):673.
    PMID: 37723511 DOI: 10.1186/s12903-023-03377-1
    BACKGROUND: The aim of this study was to evaluate the effect of thermal and mechanical cyclic aging using a mastication simulator on push-out bond strength of mandibular premolars obturated with AH Plus and BioRoot RCS root canal sealers.

    METHODS: With REVO-S files up to SU/0.06 taper, 48 single-rooted premolar teeth were instrumented. The teeth were randomly divided into two main groups (n = 24) based on the two root canal sealers used (AH Plus and BioRoot RCS). All teeth were obturated with h matched-taper single-cone. Each main group was then subdivided into three subgroups (A, B, and C) (n = 8). Group A served as the negative control group (no-thermocycling aging). While groups B and C were subjected to thermal changes in a thermocycler machine (15,000 and 30,000 thermal cycles, respectively), followed by two different dynamic loading periods, 3 × 105 and 6 × 105 in a masticatory simulator with a nominal load of 5 kg at 1.2 Hz which represent roughly 1½ and 3 years of clinical function respectively. 2 mm slice at 3 levels, apical, middle, and coronal, to obtain 3 sections were prepared and subjected to push-out test using a universal testing machine. Statistical analysis was performed using analysis of variance (ANOVA) followed by a Tukey post hoc comparisons test and an independent T-test. A significance level of 5% was used.

    RESULTS: After thermal-mechanical cyclic aging, the two root canal sealers showed a significantly decreased in push-out bond strength (p 

    Matched MeSH terms: Calcium Compounds
  8. Al-Qaisi S, Mebed AM, Mushtaq M, Rai DP, Alrebdi TA, Sheikh RA, et al.
    J Comput Chem, 2023 Jul 15;44(19):1690-1703.
    PMID: 37093704 DOI: 10.1002/jcc.27119
    In this study, structural, electronic, optical, thermoelectric, and thermodynamics properties of vacancy-ordered double perovskites Rb2 XCl6 (X = Se, Ti) were explored theoretically. The results revealed that Rb2SeCl6 and Rb2 TiCl6 are indirect band gap (Eg ) semiconductors with Eg values of 2.95 eV, and 2.84 eV respectively. The calculated properties (phonons, elastic constant, Poisson's ratio, and Pugh's ratio) revealed that both materials are dynamically and chemically stable and can exhibit brittle (Rb2 SeCl6 ) and ductile (Rb2 TiCl6 ) nature. From the analysis of optical parameters, it was noticed that the refractive index of the materials has a value of 1.5-2.0 where light absorption was found from the visible to the ultraviolet region. The thermoelectric properties determined by using the BoltzTrap code demonstrated that at room temperature, the Figure of merit (ZT) was found to be 0.74 and 0.76 for Rb2 SeCl6 and Rb2 TiCl6 , respectively. Despite a moderate value of ZT in such materials, further studies might explore effective methods for tuning the electronic band gap and improving the thermoelectric response of the material for practical energy production applications.
    Matched MeSH terms: Calcium Compounds
  9. Molahid VLM, Kusin FM, Syed Hasan SNM
    Environ Geochem Health, 2023 Jul;45(7):4439-4460.
    PMID: 36811700 DOI: 10.1007/s10653-023-01513-y
    Mining activities have often been associated with the issues of waste generation, while mining is considered a carbon-intensive industry that contributes to the increasing carbon dioxide emission to the atmosphere. This study attempts to evaluate the potential of reusing mining waste as feedstock material for carbon dioxide sequestration through mineral carbonation. Characterization of mining waste was performed for limestone, gold and iron mine waste, which includes physical, mineralogical, chemical and morphological analyses that determine its potential for carbon sequestration. The samples were characterized as having alkaline pH (7.1-8.3) and contain fine particles, which are important to facilitate precipitation of divalent cations. High amount of cations (CaO, MgO and Fe2O3) was found in limestone and iron mine waste, i.e., total of 79.55% and 71.31%, respectively, that are essential for carbonation process. Potential Ca/Mg/Fe silicates, oxides and carbonates have been identified, which was confirmed by the microstructure analysis. The limestone waste composed majorly of CaO (75.83%), which was mainly originated from calcite and akermanite minerals. The iron mine waste consisted of Fe2O3 (56.60%), mainly from magnetite and hematite, and CaO (10.74%) which was derived from anorthite, wollastonite and diopside. The gold mine waste was attributed to a lower cation content (total of 7.71%), associated mainly with mineral illite and chlorite-serpentine. The average capacity for carbon sequestration was between 7.73 and79.55%, which corresponds to 383.41 g, 94.85 g and 4.72 g CO2 that were potentially sequestered per kg of limestone, iron and gold mine waste, respectively. Therefore, it has been learned that the mine waste might be utilized as feedstock for mineral carbonation due to the availability of reactive silicate/oxide/carbonate minerals. Utilization of mine waste would be beneficial in light of waste restoration in most mining sites while tackling the issues of CO2 emission in mitigating the global climate change.
    Matched MeSH terms: Calcium Carbonate/chemistry
  10. Tie HO, Che Man H, Koyama M, Syukri F, Md Yusoff F, Toda T, et al.
    Waste Manag, 2023 Jul 01;166:194-202.
    PMID: 37178588 DOI: 10.1016/j.wasman.2023.04.046
    A modified outdoor large-scale nutrient recycling system was developed to compost organic sludge and aimed to recover clean nitrogen for the cultivation of high-value-added microalgae. This study investigated the effect of calcium hydroxide addition on enhancing NH3 recovery in a pilot-scale reactor self-heated by metabolic heat of microorganisms during thermophilic composting of dewatered cow dung. 350 kg-ww of compost was prepared at the ratio of 5: 14: 1 (dewatered cowdung: rice husk: compost-seed) in a 4 m3 cylindrical rotary drum composting reactor for 14 days of aerated composting. High compost temperature up to 67 °C was observed from day 1 of composting, proving that thermophilic composting was achieved through the self-heating process. The temperature of compost increases as microbial activity increases and temperature decreases as organic matter decreases. The high CO2 evolution rate on day 0-2 (0.02-0.08 mol/min) indicated that microorganisms are most active in degrading organic matter. The increasing conversion of carbon demonstrated that organic carbon was degraded by microbial activity and emitted as CO2. The nitrogen mass balance revealed that adding calcium hydroxide to the compost and increasing the aeration rate on day 3 volatilized 9.83 % of the remaining ammonium ions in the compost, thereby improving the ammonia recovery. Moreover, Geobacillus was found to be the most dominant bacteria under elevated temperature that functions in the hydrolysis of non-dissolved nitrogen for better NH3 recovery. The presented results show that by thermophilic composting 1 ton-ds of dewatered cowdung for NH3 recovery, up to 11.54 kg-ds of microalgae can be produced.
    Matched MeSH terms: Calcium Hydroxide
  11. Moharir KN, Pande CB, Gautam VK, Singh SK, Rane NL
    Environ Res, 2023 Jul 01;228:115832.
    PMID: 37054834 DOI: 10.1016/j.envres.2023.115832
    The Damoh district, which is located in the central India and characterized by limestone, shales, and sandstone compact rock. The district has been facing groundwater development challenges and problems for several decades. To facilitate groundwater management, it is crucial to monitoring and planning based on geology, slope, relief, land use, geomorphology, and the types of the basaltic aquifer in the drought-groundwater deficit area. Moreover, the majority of farmers in the area are heavily dependent on groundwater for their crops. Therefore, delineation of groundwater potential zones (GPZ) is essential, which is defined based on various thematic layers, including geology, geomorphology, slope, aspect, drainage density, lineament density, topographic wetness index (TWI), topographic ruggedness index (TRI), and land use/land cover (LULC). The processing and analysis of this information were carried out using Geographic Information System (GIS) and Analytic Hierarchy Process (AHP) methods. The validity of the results was trained and tested using Receiver Operating Characteristic (ROC) curves, which showed training and testing accuracies of 0.713 and 0.701, respectively. The GPZ map was classified into five classes such as very high, high, moderate, low, and very low. The study revealed that approximately 45% of the area falls under the moderate GPZ, while only 30% of the region is classified as having a high GPZ. The area receives high rainfall but has very high surface runoff due to no proper developed soil and lack of water conservation structures. Every summer season show a declined groundwater level. In this context, results of study area are useful to maintain the groundwater under climate change and summer season. The GPZ map plays an important role in implementing artificial recharge structures (ARS), such as percolation ponds, tube wells, bore wells, cement nala bunds (CNBs), continuous contour trenching (CCTs), and others for development of ground level. This study is significant for developing sustainable groundwater management policies in semi-arid regions, that are experiencing climate change. Proper groundwater potential mapping and watershed development policies can help mitigate the effects of drought, climate change, and water scarcity, while preserving the ecosystem in the Limestone, Shales, and Sandstone compact rock region. The results of this study are essential for farmers, regional planners, policy-makers, climate change experts, and local governments, enabling them to understand the groundwater development possibilities in the study area.
    Matched MeSH terms: Calcium Carbonate/analysis
  12. Rathinasamy V, Mohamad ET, Komoo I, Legiman MKA, Romanah NA, Hanapi MNB
    Environ Monit Assess, 2023 Jun 16;195(7):850.
    PMID: 37326879 DOI: 10.1007/s10661-023-11453-w
    Jurong Formation underlies part of Southern Johor Bahru which comprises well cemented and consolidated volcanic-sedimentary rocks. The study aims to assess quality and hydrogeochemistry of rock aquifer in Jurong Formation at Southern Johor Bahru which is mainly overlain by rhyolitic tuff. It also evaluates the differences in quality and hydrogeochemistry of rhyolitic tuff aquifer found in source and floodplain zones of South-West Johor Rivers Basin. In this study, a total of nine samples from four wells, namely TW1-TW4, were collected at foothills of Gunung Pulai (TW1) and Iskandar Puteri (TW2-TW4) in Southern Johor Bahru. The samples were examined for physiochemical parameters. The groundwater in the study area is fresh and non-saline with hardness of soft to hard. The pH of groundwater in source zone is significantly higher than in floodplain zone. Meanwhile, the hardness of groundwater in source zone is significantly lower than in other deep wells in floodplain zone as more calcite mineral is present. The concentration of manganese, iron and zinc is lower at source zone than floodplain zone. Three facies of water types were encountered during the study such as CaNaHCO3 in TW2, CaHCO3 in TW1 and TW3 and CaCl2 in TW4. The deep wells in floodplain zone are susceptible to saline intrusion. Finally, the groundwater quality in the study area is found to control by rock weathering especially silicates and carbonates, rainfall and proximity to seawater. This suggests the major control on groundwater chemistry is due to leaching of volcanic rocks and dissolution on calcite infillings. In conclusion, the groundwater is clean and safe in general although pH value is slightly acidic closer to straits and magnesium's presence in higher concentration at TW2.
    Matched MeSH terms: Calcium Carbonate
  13. Hatipoğlu Ö, Hatipoğlu FP, Javed MQ, Nijakowski K, Taha N, El-Saaidi C, et al.
    J Endod, 2023 Jun;49(6):675-685.
    PMID: 37094712 DOI: 10.1016/j.joen.2023.04.005
    INTRODUCTION: Direct pulp capping (DPC) procedures require the placement of a bioactive material over an exposure site without selective pulp tissue removal. This web-based multicentered survey had 3 purposes: (1) to investigate the factors that affect clinicians' decisions in DPC cases, (2) to determine which method of caries removal is preferred, and (3) to evaluate the preferred capping material for DPC.

    METHODS: The questionnaire comprised 3 sections. The first part comprised questions regarding demographic features. The second part comprised questions on how treatment plans change according to factors such as nature, location, number and size of the pulp exposure, and patients' age. The third part composed of questions on the common materials and techniques used in DPC. To estimate the effect size, the risk ratio (RR) and 95% confidence interval (CI) were calculated using a meta-analysis software.

    RESULTS: A tendency toward more invasive treatment was observed for the clinical scenario with carious-exposed pulp (RR = 2.86, 95% CI: 2.46, 2.32; P calcium silicate-based materials were preferred over calcium hydroxide-based materials (RR = 0.58, 95% CI: 0.44, 0.76; P calcium silicate-based materials appears to have replaced calcium hydroxide-based materials.

    Matched MeSH terms: Calcium Hydroxide/therapeutic use; Calcium Compounds/therapeutic use
  14. Yadav VK, Yadav KK, Alam J, Cabral-Pinto MM, Gnanamoorthy G, Alhoshan M, et al.
    Environ Sci Pollut Res Int, 2023 Jun;30(28):71766-71778.
    PMID: 34523099 DOI: 10.1007/s11356-021-15009-8
    Incense sticks ash is one of the most unexplored by-products generated at religious places and houses obtained after the combustion of incense sticks. Every year, tonnes of incense sticks ash is produced at religious places in India which are disposed of into the rivers and water bodies. The presence of heavy metals and high content of alkali metals challenges a potential threat to the living organism after the disposal in the river. The leaching of heavy metals and alkali metals may lead to water pollution. Besides this, incense sticks also have a high amount of calcium, silica, alumina, and ferrous along with traces of rutile and other oxides either in crystalline or amorphous phases. The incense sticks ash, heavy metals, and alkali metals can be extracted by water, mineral acids, and alkali. Ferrous can be extracted by magnetic separation, while calcium by HCl, alumina by sulfuric acid treatment, and silica by strong hydroxides like NaOH. The recovery of such elements by using acids and bases will eliminate their toxic heavy metals at the same time recovering major value-added minerals from it. Here, in the present research work, the effect on the elemental composition, morphology, crystallinity, and size of incense sticks ash particles was observed by extracting ferrous, followed by extraction of calcium by HCl and alumina by H2SO4 at 90-95 °C for 90 min. The final residue was treated with 4 M NaOH, in order to extract leachable silica at 90 °C for 90 min along with continuous stirring. The transformation of various minerals phases and microstructures of incense sticks ash (ISA) and other residues during ferrous, extraction, calcium, and alumina and silica extraction was studied using Fourier transform infrared (FTIR), dynamic light scattering (DLS), X-ray fluorescence (XRF), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and inductively coupled plasma-optical emission spectroscopy (ICP-OES). DLS was used for analyzing the size during the experiments while FTIR helped in the confirmation of the formation of new products during the treatments. From the various instrumental analyses, it was found that the toxic metals present in the initial incense sticks ash got eliminated. Besides this, the major alkali metals, i.e., Ca and Mg, got reduced during these successive treatments. Initially, there were mainly irregular shaped, micron-sized particles that were dominant in the incense sticks ash particles. Besides this, there were plenty of carbon particles left unburned during combustion. In the final residue, nanosized flowers shaped along with cuboidal micron-sized particles were dominant. present in If, such sequential techniques will be applied by the industries based on recycling of incense sticks ash, then not only the solid waste pollution will be reduced but also numerous value-added minerals like ferrous, silica, alumina calcium oxides and carbonates can be recovered from such waste. The value-added minerals could act as an economical and sustainable source of adsorbent for wastewater treatment in future.
    Matched MeSH terms: Calcium
  15. Mohammed AU, Aris AZ, Ramli MF, Isa NM, Arabi AS, Jabbo JN
    Environ Geochem Health, 2023 Jun;45(6):3891-3906.
    PMID: 36609946 DOI: 10.1007/s10653-022-01468-6
    Multiple interactions of geogenic and anthropogenic activities can trigger groundwater pollution in the tropical savanna watershed. These interactions and resultant contamination have been studied using applied geochemical modeling, conventional hydrochemical plots, and multivariate geochemometric methods, and the results are presented in this paper. The high alkalinity values recorded for the studied groundwater samples might emanate from the leaching of carbonate soil derived from limestone coupled with low rainfall and high temperature in the area. The principal component analysis (PCA) unveils three components with an eigenvalue > 1 and a total dataset variance of 67.37%; this implies that the temporary hardness of the groundwater and water-rock interaction with evaporite minerals (gypsum, halite, calcite, and trona) is the dominant factor affecting groundwater geochemistry. Likewise, the PCA revealed anthropogenic contamination by discharging [Formula: see text] [Formula: see text][Formula: see text] and [Formula: see text] from agricultural activities and probable sewage leakages. Hierarchical cluster analysis (HCA) also revealed three clusters; cluster I reflects the dissolution of gypsum and halite with a high elevated load of [Formula: see text] released by anthropogenic activities. However, cluster II exhibited high [Formula: see text] and [Formula: see text] loading in the groundwater from weathering of bicarbonate and sylvite minerals. Sulfate ([Formula: see text]) dominated cluster III mineralogy resulting from weathering of anhydrite. The three clusters in the Maiganga watershed indicated anhydrite, gypsum, and halite undersaturation. These results suggest that combined anthropogenic and natural processes in the study area are linked with saturation indexes that regulate the modification of groundwater quality.
    Matched MeSH terms: Calcium Carbonate/analysis; Calcium Sulfate/analysis
  16. Chen YZ, Yong MJ, Tan VY, Kong SLS, Elnawawy HMA, Yahya NA, et al.
    Eur Endod J, 2023 May;8(3):215-224.
    PMID: 37257037 DOI: 10.14744/eej.2023.36449
    OBJECTIVE: This study compared the effects of calcium chloride dihydrate (CaCl2.2H2O) on the physical properties and push-out bond strength of white Mineral Trioxide Aggregate (WMTA) and an experimental Malaysian Portland cement mixed with nano-zirconium oxide (nano-ZrO) [(radiopaque Malaysian Portland cement (RMPC). Mineral Trioxide Aggregate (MTA) was the first calcium silicate cement (CSC) introduced in dentistry, but up to date, it is an expensive cement with long setting time and causes tooth discolouration. Although Portland cement has been introduced as a potential substitute to MTA, it still faces some challenges such as long setting time and lack of sufficient radiopacity.

    METHODS: Four groups [WMTA, RMPC, fast-set WMTA (FS-WMTA) and fast-set RMPC (FS-RMPC)] were prepared. Initial setting time was evaluated using Vicat apparatus. The pH was measured at seven-day intervals. For discolouration potential, cements were packed in the pulp chamber of 46 extracted maxillary incisors. Spectrophotometric readings were obtained at seven-day intervals, and the rate of colour change (ΔE) was recorded. For the push-out bond strength testing, cements were applied in 48 sectioned root samples, and the test was performed using universal testing machine at crosshead speed of 0.5 mm/min until bond failure. Statistical analysis was done according to the nature of each group of data using SPSS 26.

    RESULTS: Addition of CaCl2.2H2O decreased the initial setting times of both RMPC and WMTA significantly (p<0.05). The pH values of FS-WMTA and FS-RMPC were comparable to their non-accelerated counterparts ranging from 10 to 12. Discolouration effect was more obviously observed with WMTA and FS-WMTA with time compared to RMPC formulations. Push-out bond strength of the two materials also showed an increase with the addition of the accelerator, however, only FS-WMTA showed statistically significant difference compared to WMTA (p<0.05).

    CONCLUSION: The addition of CaCl2.2H2O improves the physical and mechanical properties of the newly formulated RMPC and WMTA. The RMPC formulation overcomes the discolouration potential of WMTA. (EEJ-2022-12-155).

    Matched MeSH terms: Calcium Chloride
  17. Arasu K, Chang CY, Wong SY, Ong SH, Yang WY, Chong MHZ, et al.
    Osteoporos Int, 2023 Apr;34(4):783-792.
    PMID: 36808216 DOI: 10.1007/s00198-023-06702-0
    Soluble corn fibre (SCF) with calcium did not improve bone indices after 1 year in preadolescent children.

    INTRODUCTION: SCF has been reported to improve calcium absorption. We investigated the long-term effect of SCF and calcium on bone indices of healthy preadolescent children aged 9-11 years old.

    METHODS: In a double-blind, randomised, parallel arm study, 243 participants were randomised into four groups: placebo, 12-g SCF, 600-mg calcium lactate gluconate (Ca) and 12-g SCF + 600-mg calcium lactate gluconate (SCF + Ca). Total body bone mineral content (TBBMC) and total body bone mineral density (TBBMD) were measured using dual-energy X-ray absorptiometry at baseline, 6 and 12 months.

    RESULTS: At 6 months, SCF + Ca had a significant increase in TBBMC from baseline (27.14 ± 6.10 g, p = 0.001). At 12 months, there was a significant increase in TBBMC from baseline in the SCF + Ca (40.28 ± 9.03 g, p = 0.001) and SCF groups (27.34 ± 7.93 g, p = 0.037). At 6 months, the change in TBBMD in the SCF + Ca (0.019 ± 0.003 g/cm2) and Ca (0.014 ± 0.003 g/cm2) groups was significantly different (p calcium supplementation increased TBBMD at 6 months. Further work is needed to fully understand the mechanism and health benefits of prebiotics in this study population.

    CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03864172.

    Matched MeSH terms: Calcium Gluconate/pharmacology; Calcium, Dietary/pharmacology
  18. Awang MH, Hatta SFWM, Mohamad AF, Ghani RA
    J Med Case Rep, 2023 Mar 02;17(1):73.
    PMID: 36859300 DOI: 10.1186/s13256-023-03764-w
    BACKGROUND: Denosumab is known to cause abnormalities in calcium homeostasis. Most of such cases have been described in patients with underlying chronic kidney disease or severe vitamin D deficiency. Previous bariatric surgery could also contribute to hypocalcemia and deterioration in bone health.

    CASE PRESENTATION: We present a case of a 61-year-old Malay female with worsening bilateral limb weakness, paresthesia, and severe carpopedal spasm a week after receiving subcutaneous denosumab for osteoporosis. She had a history of gastric bypass surgery 20 years ago. Post gastric bypass surgery, she was advised and initiated on lifelong calcium, vitamin D, and iron supplementations that she unfortunately stopped taking 5 years after surgery. Her last serum blood tests, prior to initiation on denosumab, were conducted in a different center, and she was told that she had a low calcium level; hence, she was advised to restart her vitamin and mineral supplements. Laboratory workup revealed severe hypocalcemia (adjusted serum calcium of 1.33 mmol/L) and mild hypophosphatemia (0.65 mmol/L), with normal magnesium and renal function. Electrocardiogram showed a prolonged QTc interval. She required four bolus courses of intravenous calcium gluconate, and three courses of continuous infusions due to retractable severe hypocalcemia (total of 29 vials of 10 mL of 10% calcium gluconate intravenously). In view of her low vitamin D level of 33 nmol/L, she was initiated on a loading dose of cholecalciferol of 50,000 IU per week for 8 weeks. However, despite a loading dose of cholecalciferol, multiple bolus courses, and infusions of calcium gluconate, her serum calcium hovered around only 1.8 mmol/L. After 8 days of continuous intravenous infusions of calcium gluconate, high doses of calcitriol 1.5 μg twice daily, and 1 g calcium carbonate three times daily, her serum calcium stabilized at approximately 2.0 mmol/L. She remained on these high doses for over 2 months, before they were gradually titrated down to ensure sustainability of a safe calcium level.

    CONCLUSION: This case report highlights the importance of screening for risk factors for iatrogenic hypocalcemia and ensuring normal levels before initiating denosumab. The patient history of bariatric surgery could have worsened the hypocalcemia, resulting in a more severe presentation and protracted response to oral calcium and vitamin D supplementation.

    Matched MeSH terms: Calcium; Calcium Gluconate
  19. Kusin FM, Hasan SNMS, Molahid VLM, Yusuff FM, Jusop S
    Environ Sci Pollut Res Int, 2023 Feb;30(9):22188-22210.
    PMID: 36282383 DOI: 10.1007/s11356-022-23677-3
    Mining waste that is rich in iron-, calcium- and magnesium-bearing minerals can be a potential feedstock for sequestering CO2 by mineral carbonation. This study highlights the utilization of iron ore mining waste in sequestering CO2 under low-reaction condition of a mineral carbonation process. Alkaline iron mining waste was used as feedstock for aqueous mineral carbonation and was subjected to mineralogical, chemical, and thermal analyses. A carbonation experiment was performed at ambient CO2 pressure, temperature of 80 °C at 1-h exposure time under the influence of pH (8-12) and particle size (
    Matched MeSH terms: Calcium Carbonate/chemistry
  20. Hafsan H, Mahmood Saleh M, Baban J, Mohammed F, Ahmed Hamza T, Ibrahim I, et al.
    Arch Razi Inst, 2023 Feb;78(1):107-114.
    PMID: 37312704 DOI: 10.22092/ARI.2022.359524.2443
    Phytic acid is a stored form of phosphorus in cereals, 65 to 70% of phosphorus in plant sources is phytate, and broilers are only able to use part of the phosphorus in plant sources. To meet the needs of chickens, it is necessary to use other artificial resources, which not only impose part of the cost of the breeding period because of its presence in the manure but is one of the factors polluting the environment. This study aimed to use different levels of phytase enzyme to reduce dietary phosphorus levels. 600 Ross 308 broilers were used in this experiment with five treatments and six replications, and in each replication, 20 chickens were used in a completely randomized design (CRD). Experimental treatments include 1) basal diet (control) 2) basal diet with 15% less phosphorus 3) basal diet with 15% less phosphorus + 1250 (FTU) phytase enzyme 4) basal diet with 15% less phosphorus + 2500 (FTU) phytase enzyme 5) basal diet with 15% less phosphorus + 5000 (FTU) phytase enzyme. The evaluated traits included weekly feed intake, weekly weight gain, feed conversion ratio, carcass characteristics, ash, calcium, and bone phosphorus. The use of phytase enzyme in different diets had no significant effect on food intake, weight gain, and feed conversion ratio (P>0.05). However, the use of phytase in different diets significantly affected the percentage of Gizzard, Heart, Liver, Proventriculus, and Spleen (P<0.05). The most changes were the increase in the ratio of feed intake and weight gain in the fourth week compared to the third week so that the changes in the ratio of feed intake ranged from 1.85 to 1.91, and this ratio for weight gain also ranged from 3.12 to 3.86 was recorded, and the lowest feed conversion ratio was obtained at the same age. The percentage of raw ash in broiler chickens was significantly increased by adding dietary phytase. The lowest amount of ash, calcium, and phosphorus belonged to the second group (diets with low phosphorus and no enzyme). The difference between the other groups and the control was not significant. Feed intake, weight gain, and feed conversion ratio with the addition of phytase enzyme were not affected by phosphorus reduction and had no significant effect on carcass characteristics. Environmental pollution can be prevented by reducing the level of dietary phosphorus and reducing excreted phosphorus.
    Matched MeSH terms: Calcium
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