Displaying publications 1 - 20 of 839 in total

Abstract:
Sort:
  1. Oliveiro CJ
    Matched MeSH terms: Calcium; Calcium, Dietary
  2. Morris JP, Oliveiro CJ
    Matched MeSH terms: Calcium, Dietary
  3. Águila-Almanza E, Hernández-Cocoletzi H, Rubio-Rosas E, Calleja-González M, Lim HR, Khoo KS, et al.
    Chemosphere, 2022 Feb;288(Pt 2):132550.
    PMID: 34656622 DOI: 10.1016/j.chemosphere.2021.132550
    The final disposal of waste generated by human activities has been turned into a great challenge; until now, little attention has been paid to organic waste, particularly from the restaurant sector. This work describes the process of obtaining calcium carbonate contained in oyster and clam shells re-collected in seafood restaurants. The IR absorption spectra of all the samples revealed the presence of characteristic bands of the carbonate group located at 872, 712 and 1414 cm-1; the peak at 1081 cm-1 of the clamshells confirms the presence of the aragonite phase. The SEM images allow observing a granular morphology whose agglomerates having a size within the range of 0.5-15 μm in brown shells, and a lower dispersion prevails in the grey species and oyster shells that go from 0.3 to 5.9 μm. All of the shells were found to be composed of carbon (C), oxygen (O2) and calcium (Ca) in different concentrations. The calcium carbonate obtained from clamshells has an orthorhombic crystalline structure, while the oyster carbonate has a rhombohedral structure as the calcium carbonate used in the construction industry; the morphology particles also coincide with each other. The material obtained combined with a mixture composed of resin, cellulose, and granules were used to prepare a paste, which was used as a residential finish.
    Matched MeSH terms: Calcium Carbonate*; Calcium, Dietary
  4. Lee TS
    The rates of rise of the plasma potassium concentrations are not affected by the nature ot the preservative solutions although the solutions influence in a marked degree the rates of haemolysis. The rise in the plasma potassium luvel exhibits two phases. It rises very rapidly for the first ten days of storage, increasing to 12 times the initial concentration in that brief period, after which the change is by comparison much slower. Variation in storage temperature has a greater effect relatively on the increase in the extra-cellular potassium concentration than daily shaking. The plasma calcium level falls by about 25 per cent of the original quantity and then begins to rise when the blood starts to haemolyse. It is suggested that it is the ionised calcium that is affected in this phenomenon. Storage at 38 degree Celcius hastens this fall and rise and so also does the effect of daily shaking.
    Matched MeSH terms: Calcium
  5. Chukwu SC, Ibeji CA, Ogbu C, Oselebe HO, Okporie EO, Rafii MY, et al.
    Sci Rep, 2022 Nov 09;12(1):19054.
    PMID: 36351926 DOI: 10.1038/s41598-022-16833-9
    Mushrooms are fleshy fungi valued globally for their nutritional and medical benefits. The study was conducted at Ebonyi State University Mushroom Center, Abakaliki, to determine an optimum level of limestone (CaCO3) on the genotypes for maximum growth and yield. The experiment was carried out as a split-plot experiment in a completely randomized design (CRD) with the use of Oyster mushroom variety. The two genotypes (GI and GII) were placed in the whole plot while limestone was placed in the sub-plot which consisted of five rates of CaCO3(Og,5 g, 10 g, 15 g and 20 g). Sawdust and rice husk substrates were used at the ratio of 60:40 and sterilized for six hours at 121 °C using the steam sterilization cylinder. The media bags were off-loaded after one day and allowed to further cool for another day before inoculation. The cultured spawn was used to inoculate the media upon cooling at room temperature. Data were collected on agro-morphological parameters such as primordial initiation, stalk height, stalk diameter, number of branches, number of fruits, number of productive bags, fresh and dry weights, and subjected to analysis of variance (ANOVA). The result obtained indicated that there was a significant difference (P  0.05) in all parameters evaluated except the stalk diameter. Genotype I initiated more primordial compared to primordial initiation in genotype II and they differed significantly (p 
    Matched MeSH terms: Calcium Carbonate
  6. 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
  7. Tuygunov N, Khairunnisa Z, Yahya NA, Aziz AA, Zakaria MN, Israilova NA, et al.
    Dent Mater J, 2024 Jan 30;43(1):1-10.
    PMID: 38220163 DOI: 10.4012/dmj.2023-132
    This systematic review investigates the effectiveness of calcium and phosphate ions release on the bioactivity and remineralization potential of glass ionomer cement (GIC). Electronic databases, including PubMed-MEDLINE, Scopus, and Web of Science, were systematically searched according to PRISMA guidelines. This review was registered in the PROSPERO database. Five eligible studies on modifying GIC with calcium and phosphate ions were included. The risk of bias was assessed using the RoBDEMAT tool. The incorporation of these ions into GIC enhanced its bioactivity and remineralization properties. It promoted hydroxyapatite formation, which is crucial for remineralization, increased pH and inhibited cariogenic bacteria growth. This finding has implications for the development of more effective dental materials. This can contribute to improved oral health outcomes and the management of dental caries, addressing a prevalent and costly oral health issue. Nevertheless, comprehensive longitudinal investigations are needed to evaluate the clinical efficacy of this GIC's modification.
    Matched MeSH terms: Calcium
  8. Zyoud SH, Al-Jabi SW, Sweileh WM, Waring WS
    Hum Exp Toxicol, 2015 Nov;34(11):1162-70.
    PMID: 25673180 DOI: 10.1177/0960327115571768
    PURPOSE: Calcium channel blockers (CCBs) were the most common agents associated with a significant morbidity and mortality rate. The main objective of this study was to examine the publication pattern related to CCBs poisoning at the global level using bibliometric analysis of articles published in SciVerse Scopus online database.
    METHODS: Data were searched for documents that contained specific words regarding CCB poisoning as keywords in the title. No time period limitations were specified in the search regarding the starting year. The ending date of the search was 31 December 2012.
    RESULTS: The criteria were met by 713 publications from 53 countries. The largest number of articles associated with CCBs was from the United States (30%), followed by the United Kingdom (7.4%), Japan (6%), and Germany (5.6%). No data related to CCBs were published from 159 (75%) of 212 countries registered in World Bank online database. There was no correlation between the number of published articles in the country and its population size (r = 0.03, p > 0.926). United Kingdom and Australia were the leading countries in terms of number of CCBs publications per million inhabitants (0.83 and 0.82 articles per million inhabitants, respectively), followed by the United States (0.68). Countries with a large population, such as India, tended to rank relatively low (0.01 articles per million inhabitants). The total number of citations at the time of data analysis (23 October 2014) was 6462, with an average of 9.1 citations per document. The highest median (interquartile range) number of citations was 8 (8-18) for the United States, followed by 6 (1-21) for Australia, 5 (1-15) for the United Kingdom, and 5 (1-24) for Canada. The h-index of the retrieved documents was 37.
    CONCLUSIONS: Scientific production on CCBs poisoning is increasing; nonetheless, the international collaboration is still rare. The amount of CCBs-based research activity was low or not available in most countries. More regional epidemiological studies are required to bridge the gap in CCBs-based research and to promote better evaluation of CCBs poisoning worldwide.
    KEYWORDS: Bibliometric; Scopus; calcium channel blockers; citations; drug overdose; poisoning; toxicity
    Matched MeSH terms: Calcium Channel Blockers*
  9. Rosli NA, Aziz HA, Selamat MR, Lim LLP
    J Environ Manage, 2020 Jun 01;263:110420.
    PMID: 32883483 DOI: 10.1016/j.jenvman.2020.110420
    This study proposed the recycling of sewage sludge (SS) and red gypsum (RG) as potential temporary landfill cover materials. Mixtures with different SS and RG compositions were prepared and tested in determining the most suitable design mix based on the resulting physical, mechanical, and geotechnical properties, namely the hydraulic conductivity, compressive strength, and plasticity. A maximum compressive strength of 524 kPa was achieved for the optimum SS:RG composition of 1:1, corresponding to Ca:Si composition of 2.5:1, which was appropriate to form the calcium silicate hydrate (CSH) gel. The SS and RG compositions did not affect the hydraulic conductivity, which was in the order 10-5 cm/s for all mixtures. Mixtures with RG greater than SS in composition exhibited plastic behaviour due to the Fe content in the RG, which helped minimize the risk of cracking. The optimum mixture had compressive strength greater than the specified minimum of 345 kPa, medium hydraulic conductivity, and moderate plasticity, thus appropriate for application as an alternative material for the temporary landfill cover in the tropics.
    Matched MeSH terms: Calcium Sulfate*
  10. Alhajj MN, Daud F, Al-Maweri SA, Johari Y, Ab-Ghani Z, Jaafar M, et al.
    J Esthet Restor Dent, 2022 Dec;34(8):1166-1178.
    PMID: 36239133 DOI: 10.1111/jerd.12974
    OBJECTIVE: To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

    METHODS: A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value <0.05.

    RESULTS: A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD = 0.03; 95% CI = -0.55, 0.60; p = 0.93), and calcium silicate-based group (SMD = 0.02; 95% CI = -0.31, 0.35; p = 0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias.

    CONCLUSION: The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers.

    CLINICAL SIGNIFICANCE: The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

    Matched MeSH terms: Calcium Hydroxide/chemistry
  11. Furusawa G, Iwamoto K
    PeerJ, 2022;10:e12867.
    PMID: 35223202 DOI: 10.7717/peerj.12867
    Inorganic and synthetic flocculants are widely investigated for removing harmful microalgae, such as Microcystis aeruginosa. However, their toxicity and non-biodegradability are shortcomings. Bioflocculants based on extracellular polysaccharides have attracted much attention as alternative flocculants. However, its high production cost is a limiting factor for applying bioflocculants. Here, we investigate the potential of the dead cells of a marine filamentous bacterium, Aureispira sp. CCB-QB1, as a novel flocculant on M. aeruginosa cells. The removal efficiency of M. aeruginosa cells by the dead cells was measured by mixing and shaking both components in a buffer with 5 mM CaCl2 in different incubation times and concentrations of the dead cells. After that, the minimum effective concentration of CaCl2 was determined. The combination effect of FeCl3 and the dead cells on the removal efficiency was tested. The structure of cell aggregates consisted of the dead cells and M. aeruginosa cells were also observed using a scanning electron microscope. The maximum removal efficiency (75.39%) was reached within 3 min in the presence of CaCl2 when 5 mg/ml of the dead cells (wet cells) were added. The optimal concentration of CaCl2 was 5 mM. The combination of the dead cells and a low concentration of FeCl3 (10 mg/L) with 5 mM of CaCl2 significantly improved the removal efficiency by about 1.2 times (P 
    Matched MeSH terms: Calcium Chloride/pharmacology
  12. 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*
  13. Acharya M, Singh N, Gupta G, Tambuwala MM, Aljabali AAA, Chellappan DK, et al.
    Cell Signal, 2024 Apr;116:111043.
    PMID: 38211841 DOI: 10.1016/j.cellsig.2024.111043
    Calcium is a ubiquitous second messenger that is indispensable in regulating neurotransmission and memory formation. A precise intracellular calcium level is achieved through the concerted action of calcium channels, and calcium exerts its effect by binding to an array of calcium-binding proteins, including calmodulin (CAM), calcium-calmodulin complex-dependent protein kinase-II (CAMK-II), calbindin (CAL), and calcineurin (CAN). Calbindin orchestrates a plethora of signaling events that regulate synaptic transmission and depolarizing signals. Vitamin D, an endogenous fat-soluble metabolite, is synthesized in the skin upon exposure to ultraviolet B radiation. It modulates calcium signaling by increasing the expression of the calcium-sensing receptor (CaSR), stimulating phospholipase C activity, and regulating the expression of calcium channels such as TRPV6. Vitamin D also modulates the activity of calcium-binding proteins, including CAM and calbindin, and increases their expression. Calbindin, a high-affinity calcium-binding protein, is involved in calcium buffering and transport in neurons. It has been shown to inhibit apoptosis and caspase-3 activity stimulated by presenilin 1 and 2 in AD. Whereas CAM, another calcium-binding protein, is implicated in regulating neurotransmitter release and memory formation by phosphorylating CAN, CAMK-II, and other calcium-regulated proteins. CAMK-II and CAN regulate actin-induced spine shape changes, which are further modulated by CAM. Low levels of both calbindin and vitamin D are attributed to the pathology of Alzheimer's disease. Further research on vitamin D via calbindin-CAMK-II signaling may provide newer insights, revealing novel therapeutic targets and strategies for treatment.
    Matched MeSH terms: Calcium; Calcium-Binding Proteins; Calcium Channels; Calcium Signaling; Calcium-Calmodulin-Dependent Protein Kinase Type 2
  14. Jahidin AH, Stewart TA, Thompson EW, Roberts-Thomson SJ, Monteith GR
    Biochem Biophys Res Commun, 2016 Sep 02;477(4):731-736.
    PMID: 27353380 DOI: 10.1016/j.bbrc.2016.06.127
    Two-pore channel proteins, TPC1 and TPC2, are calcium permeable ion channels found localized to the membranes of endolysosomal calcium stores. There is increasing interest in the role of TPC-mediated intracellular signaling in various pathologies; however their role in breast cancer has not been extensively evaluated. TPC1 and TPC2 mRNA was present in all non-tumorigenic and tumorigenic breast cell lines assessed. Silencing of TPC2 but not TPC1 attenuated epidermal growth factor-induced vimentin expression in MDA-MB-468 breast cancer cells. This effect was not due to a general inhibition of epithelial to mesenchymal transition (EMT) as TPC2 silencing had no effect on epidermal growth factor (EGF)-induced changes on E-cadherin expression. TPC1 and TPC2 were also shown to differentially regulate cyclopiazonic acid (CPA)-mediated changes in cytosolic free Ca(2+). These findings indicate potential differential regulation of signaling processes by TPC1 and TPC2 in breast cancer cells.
    Matched MeSH terms: Calcium/metabolism; Calcium Channels/genetics; Calcium Channels/metabolism*; Calcium Signaling*
  15. Vakili AH, Selamat MR, Moayedi H
    ScientificWorldJournal, 2013;2013:547615.
    PMID: 23864828 DOI: 10.1155/2013/547615
    Use of dispersive clay as construction material requires treatment such as by chemical addition. Treatments to dispersive clay using pozzolan and Portland cement, singly and simultaneously, were carried out in this study. When used alone, the optimum amount of pozzolan required to treat a fully dispersive clay sample was 5%, but the curing time to reduce dispersion potential, from 100% to 30% or less, was 3 month long. On the other hand, also when used alone, a 3% cement content was capable of reducing dispersion potential to almost zero percent in only 7 days; and a 2% cement content was capable of achieving similar result in 14 days. However, treatment by cement alone is costly and could jeopardize the long term performance. Thus, a combined 5% pozzolan and 1.5% cement content was found capable of reducing dispersion potential from 100% to zero percent in 14 days. The results indicate that although simultaneous treatment with pozzolan and cement would extend the required curing time in comparison to treatment by cement alone of a higher content, the task could still be carried out in a reasonable period of curing time while avoiding the drawbacks of using either pozzolan or cement alone.
    Matched MeSH terms: Calcium Carbonate/chemistry*; Calcium Hydroxide/chemistry*
  16. Rahman RA
    PhytoKeys, 2019;118:65-73.
    PMID: 30863195 DOI: 10.3897/phytokeys.118.32186
    A new species, Microchiritahairulii Rafidah (Gesneriaceae) from limestone hills in Perlis, Peninsular Malaysia, is described and illustrated. Diagnostic characters, description, detailed illustrations, geographical distribution, regional provisional conservation status assessment (Endangered) and ecological observations of the new taxon, as well as an updated key to Microchirita species in Peninsular Malaysia, are provided.
    Matched MeSH terms: Calcium Carbonate
  17. Alias N, Ali Umar A, Malek NAA, Liu K, Li X, Abdullah NA, et al.
    ACS Appl Mater Interfaces, 2021 Jan 20;13(2):3051-3061.
    PMID: 33410652 DOI: 10.1021/acsami.0c20137
    A deficiency in the photoelectrical dynamics at the interface due to the surface traps of the TiO2 electron transport layer (ETL) has been the critical factor for the inferiority of the power conversion efficiency (PCE) in the perovskite solar cells. Despite its excellent energy level alignment with most perovskite materials, its large density of surface defect as a result of sub lattice vacancies has been the critical hurdle for an efficient photovoltaic process in the device. Here, we report that atoms thick 2D TiS2 layer grown on the surface of a (001) faceted and single-crystalline TiO2 nanograss (NG) ETL have effectively passivated the defects, boosting the charge extractability, carrier mobility, external quantum efficiency, and the device stability. These properties allow the perovskite solar cells (PSCs) to produce a PCE as high as 18.73% with short-circuit current density (Jsc), open-circuit voltage (Voc), and fill-factor (FF) values as high as 22.04 mA/cm2, 1.13 V, and 0.752, respectively, a 3.3% improvement from the pristine TiO2-NG-based PSCs. The present approach should find an extensive application for controlling the photoelectrical dynamic deficiency in perovskite solar cells.
    Matched MeSH terms: Calcium Compounds
  18. Irzaman, Jamal, Z., Idris, M.S., Kurnia, D., Barmawi, M.
    MyJurnal
    The specimens used were CaCO3 (Sigma Aldrich, purity 99.9 %). We have 23 parameters and 20 iterations, including two theta zero error, scale factor, thermal effect, coefficients for polynomial describing the background; U, V, W and mixing parameters of the profile peak function, lattice constants, positional parameters and overall isotropic temperature factors. Most the samples show that the crystal structure are rhombohedral with lattice constants a = b = 4.981 Å, c = 17.044 Å and space group is R3C. The microstrain (K) and the particle size (V) of CaCO3 ceramic were calculated using 10 the full width at half maximum (FWHM) of diffraction peaks from (0 1 2), (1 0 4), (0 0 6), (1 1 0), (1 1 3), (2 0 2), (0 1 8), (1 1 6), (2 2 1 ), (1 2 2) crystal planes are 2.1 x 10-2 and
    362 nm, respectively.
    Matched MeSH terms: Calcium Carbonate
  19. Ummul-Nazrah AR, Mohd Hairul MA, Kamin I, Kiew R, Ong PT
    PhytoKeys, 2018.
    PMID: 29780269 DOI: 10.3897/phytokeys.98.23903
    Vatica najibiana Ummul-Nazrah (Dipterocarpaceae), from the Relai Forest Reserve, Gua Musang, Kelantan and Gua Tanggang, Merapoh, Pahang, is described and illustrated. This species is Endangered and known from small populations restricted to two isolated karst limestone hills. The type locality, Relai Forest Reserve limestone, is currently under threat from encroaching oil palm plantations and ongoing logging, which, if it continues, will threaten the Kelantan population with extinction. The morphology of V. najibiana and the similar V. odorata subsp. odorata and V. harmandiana is compared.
    Matched MeSH terms: Calcium Carbonate
  20. WAN ZAWIAH WAN ABDULLAH, MD ZAIDI YAHAYA, MOHAMAD YUSOF MASKAT
    Sains Malaysiana, 2012;41:411-418.
    Kajian ini dijalankan bagi menentukan kesan penambahan kalsium karbonat (CaCO3) dan sukrosa ke atas ekstrak roselle dengan menggunakan Kaedah Respon Permukaan. Sebanyak 21 perlakuan digunakan berdasarkan reka bentuk eksperimen Central Composite Rotatable Design (CCRD). Penentuan nilai pH dan Briks telah dijalankan. Bagi nilai pH, model yang didapati adalah 4.03+0.39x1-8.20x2-0.05x1 2-4.16x2 2-0.02x1x2 dengan nilai x1 adalah kalsium karbonat dan nilai x2 adalah sukrosa. Nilai positif pada kepekatan kalsium menunjukkan penambahan kalsium meningkatkan nilai pH ekstrak roselle. Model untuk Briks adalah 8.91 + 0.23x1 + 2.20x2. Nilai positif pada kepekatan kalsium dan sukrosa menunjukkan penambahan kalsium dan sukrosa meningkatkan nilai Briks ekstrak roselle. Penilaian sensori dengan menggunakan panel terlatih (n=8) menunjukkan penambahan sukrosa meningkatkan penerimaan keseluruhan terhadap ekstrak Roselle. Manakala, kesan penambahan kalsium karbonat telah mengurangkan penerimaan keseluruhan kerana ia merendahkan rasa masam.
    Matched MeSH terms: Calcium Carbonate
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links