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Biomineralization, mechanical, antibacterial and biological investigation of larnite and rankinite bioceramics

Venkatraman SK, Choudhary R, Krishnamurithy G, Raghavendran HRB, Murali MR, Kamarul T, et al.

Mater Sci Eng C Mater Biol Appl, 2021 Jan;118:111466.
PMID: 33255048 DOI: 10.1016/j.msec.2020.111466

This work is aimed to develop a biocompatible, bactericidal and mechanically stable biomaterial to overcome the challenges associated with calcium phosphate bioceramics. The influence of chemical composition on synthesis temperature, bioactivity, antibacterial activity and mechanical stability of least explored calcium silicate bioceramics was studied. The current study also investigates the biomedical applications of rankinite (Ca3Si2O7) for the first time. Sol-gel combustion method was employed for their preparation using citric acid as a fuel. Differential thermal analysis indicated that the crystallization of larnite and rankinite occurred at 795 °C and 1000 °C respectively. The transformation of secondary phases into the desired product was confirmed by XRD and FT-IR. TEM micrographs showed the particle size of larnite in the range of 100-200 nm. The surface of the samples was entirely covered by the dominant apatite phase within one week of immersion. Moreover, the compressive strength of larnite and rankinite was found to be 143 MPa and 233 MPa even after 28 days of soaking in SBF. Both samples prevented the growth of clinical pathogens at a concentration of 2 mg/mL. Larnite and rankinite supported the adhesion, proliferation and osteogenic differentiation of hBMSCs. The variation in chemical composition was found to influence the properties of larnite and rankinite. The results observed in this work signify that these materials not only exhibit faster biomineralization ability, excellent cytocompatibility but also enhanced mechanical stability and antibacterial properties.

Matched MeSH terms: Calcium Compounds
Fulltext Endophytic Bacteria Isolated from Citrus Plants for Biological Control of Citrus Canker in Lime Plants

Daungfu O, Youpensuk S, Lumyong S

Trop Life Sci Res, 2019 Jan;30(1):73-88.
PMID: 30847034 DOI: 10.21315/tlsr2019.30.1.5

Citrus canker caused by Xanthomonas citri subsp. citri is a disease affecting the yield and fruit quality of lime (Citrus aurantiifolia). This research investigated endophytic bacteria obtained from six healthy Citrus spp. to inhibit the pathogen and to control citrus canker on lime plants. Numbers of the endophytic bacteria isolated from C. aurantifolia, C. hystrix, C. maxima, C. nobilis, C. reticulata and C. sinensis were 28, 25, 29, 42, 12 and 34 isolates, respectively. The selected endophytic bacteria that were effective against X. citri subsp. citri were Bacillus amyloliquefaciens LE109, B. subtilis LE24 and B. tequilensis PO80. The optimum culture medium for an antagonistic effect on the pathogen in B. amyloliquefaciens LE109 and B. tequilensis PO80 was yeast extract peptone dextrose broth, and in B. subtilis LE24 was modified soluble starch broth. To control citrus canker in lime, young expanded leaves of lime plants were aseptically punctured and inoculated with 30 μl of bacterial suspension of the pathogen (108 CFU/ml in 0.85% NaCl) per punctured location. After the pathogenic inoculation for 24 h, the leaves were then inoculated with 30 μl of the selected endophytic bacteria (108 CFU/ml in 0.85% NaCl), and treated with 30 μl of the culture media containing bioactive compounds produced by the selected endophytic bacteria. The leaves inoculated with cell suspensions of B. amyloliquefaciens LE109 or B. subtilis LE24 could completely control citrus canker. However, the leaves inoculated with B. tequilensis PO80 displayed 10% disease incidence. Additionally, the leaves treated with the crude bioactive compounds of B. amyloliquefaciens LE109 or B. subtilis LE24 could completely control citrus canker. Notably, the leaves treated with the crude bioactive compounds of B. tequilensis PO80 displayed 5% disease incidence. The results of this study showed that the Bacillus strains play important roles in the biocontrol of citrus canker in lime.

Matched MeSH terms: Calcium Compounds
Histological evaluation of a novel phosphorylated pullulan-based pulp capping material: An in vivo study on rat molars

Islam R, Toida Y, Chen F, Tanaka T, Inoue S, Kitamura T, et al.

Int Endod J, 2021 Oct;54(10):1902-1914.
PMID: 34096634 DOI: 10.1111/iej.13587

AIM: To evaluate the dental pulp response to a novel mineral trioxide aggregate containing phosphorylated pullulan (MTAPPL) in rats after direct pulp capping.
METHODS: Ninety-six cavities were prepared in the maxillary first molars of 56 male Wistar rats. The dental pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials: MTAPPL; phosphorylated pullulan (PPL); a conventional MTA (Nex-Cem MTA, NCMTA; positive control); and Super-Bond (SB; negative control). All cavities were restored with SB and observed for pulpal responses at 1-, 3-, 7- and 28-day intervals using a histological scoring system. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-test with Bonferroni's correction, and the level of significance was set at 0.05. DMP1 and CD34 antigen were used to evaluate odontoblast differentiation and pulpal vascularization, respectively.
RESULTS: On day 1, mild inflammatory cells were present in MTAPPL and NCMTA groups; fewer inflammatory cells were present in the PPL, whereas SB was associated with a mild-to-moderate inflammatory response. A significant difference was observed between PPL and SB (p .05). SB exhibited incomplete mineralized tissue barriers, significantly different from NCMTA, MTAPPL and PPL (p

Matched MeSH terms: Calcium Compounds
Fulltext Synthesis and characterization of β-tricalcium phosphate ceramic via sol-gel method

Mohd Al Amin Muhamad Nor, Maryam Mohd Ridzuan, Zainal Arifin Ahmad

Journal of Nuclear and Related Technologies, 2009;2009(1):199-205.
MyJurnal

Ceramic materials play key role in several biomedical applications. One of them is bone graft which is use in treating bone defect which caused by injury or osteoporosis. Calcium phosphates based ceramic are preferred as bone grafts in hard tissue engineering because of their chemical compositions are similar to the composition of human bone, superior bioresorbable and bioactivity. In this study, β-tricalcium phosphate (β-TCP) ceramic was synthesized by using sol-gel method. Phosphorous pentoxide (P2O5) and calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) were used as calcium and phosphate precursors. The effects of calcination temperature on the synthesis powder were studied using the XRD, SEM-EDS and FTIR techniques. It was found that calcination temperature greatly influence the purity of the synthesized powders. The β-TCP was the dominant phase with the formation of α-TCP at calcination temperature from 600 to 800°C. Pure β-TCP was obtained at calcination of 900°C. As the temperature increased to 1000°C, the β-TCP was decomposed to for calcium phosphate oxide (CPO). The sol-gel method has some advantages over other methods, mainly its simplicity and ability to produce pure β-TCP at lower calcination temperature.

Matched MeSH terms: Calcium Compounds
Fulltext In vitro antimicrobial activity of musk lime, key lime and lemon extracts against food related pathogenic and spoilage bacteria

Velu, S., Abu Bakar, F., Saari, N., Zaman, M.Z., Mahyudin, N.A.

International Food Research Journal, 2014;21(1):379-386.
MyJurnal

The demand for novel antimicrobial agents from natural resources has been increased worldwide for food conservation purpose. In this study antimicrobial activity of musk lime, key lime and lemon were evaluated against various food borne pathogens and spoilage bacteria using disc diffusion test. Type of extraction solvent and concentration level significantly influenced the antibacterial activity of all the extracts. Ethanol extracts of musk lime, key lime and lemon exhibited significant broadest inhibitory activity at 100% concentration level (pure extract) compared to water and juice extracts. 100% ethanol extracts of musk lime (39.7 mm), key lime (26.7 mm) and lemon (32.0 mm) exhibited the largest diameter of inhibition zone (DIZ) against Aeromonas veronii. 100% water extracts of musk lime (25.3 mm), key lime juice extract (23.3 mm) and water extracts of lemon (23.7 mm) was most effective against food spoilage bacteria, A. veronii. The prominent results of the antimicrobial activity from lime, key lime and lemon extracts may attribute them as potential natural food preservatives and could be used in pharmaceuticals field.

Matched MeSH terms: Calcium Compounds
Fulltext In vitro antioxidant capacities and antidiabetic properties of phenolic extracts from selected citrus peels

Lim, S.M., Loh, S.P.

International Food Research Journal, 2016;23(1):211-219.
MyJurnal

This study aims to determine the antioxidant capacities (AC) and antidiabetic properties of
phenolic extracts (free and bound) from white Tambun pomelo peels, kaffir lime peels, lime
peels and calamansi peels. AC, total phenolic content (TPC) and antidiabetic properties of
selected citrus peels extracts were determined spectrophotometrically using 2,2-Diphenyl-1-
picrylhydrazyl free radical (DPPH) scavenging, ferric-reducing antioxidant power (FRAP),
Folin-Ciocalteu (FC) and α-amylase and α-glucosidase inhibition assay, respectively. This
study found that the methanolic extract of kaffir lime showed the best AC with the lowest
IC50 value of DPPH radical (7.51 ± 0.50 mg/ml) and highest FRAP value [369.48 ± 20.15
mM Fe (II) E/g DW]. TPC of free phenolic extracts of all citrus peels were significantly (p<
0.05) higher compared to the bound phenolic extracts with extract of calamansi showed the
highest TPC. Free- and bound phenolic extract of calamansi also had the highest α-amylase
inhibition activity (61.79 ± 4.13%; 45.30 ± 5.35%) respectively. The highest inhibitory effect in
α-glucosidase inhibition assay of free- and bound phenolic extracts were white Tambun pomelo
(41.06 ± 10.94%) and calamansi (43.99 ± 22.03%) respectively. Hence, the citrus peels could
be furthered study for their potential in management and/or prevention of diabetes.

Matched MeSH terms: Calcium Compounds
Fulltext Alkaline phosphatase activity assessment of two endodontic materials: a preliminary study

Rajan, S., Awang, H., Pooi, A.H., Hassan, H., Devi, S.

Ann Dent, 2008;15(1):5-10.
MyJurnal

Objective: An in vitro assessment of MG-63 human osteosarcoma cells' alkaline phosphatase (ALP) activity when in contact with calcium hydroxide powder (CH), paste (CHP) and grey mineral trioxide aggregate (MTA). Methods: MG-63 cells were seeded to the three selected materials for durations of 0.25, 0.5, 1, 24, 48 and 72 hours. BCIP-NBT assay was used and ALP activity quantified using ELISA reader at 410 nm. Results: The overall analysis for ALP activity indicated significant interaction between test materials and control (maintenance medium). Subsequently, the test materials were paired and analysed for initial (0.25, 0.5, 1 hour) and delayed response (24, 48 and 72 hours). During the initial response, CH exhibited an increased ALP activity compared to MTA. This interaction was not dependant on duration. The delayed response exhibited elevated ALP activity with CHP when compared to MTA and CH. The interaction of CHP was dependant on duration. Conclusion: All three materials exhibited increased ALP activity.

Matched MeSH terms: Calcium Compounds
Efficacy of Biodentine and Mineral Trioxide Aggregate in Primary Molar Pulpotomies-A Systematic Review and Meta-Analysis With Trial Sequential Analysis of Randomized Clinical Trials

Nagendrababu V, Pulikkotil SJ, Veettil SK, Jinatongthai P, Gutmann JL

J Evid Based Dent Pract, 2019 03;19(1):17-27.
PMID: 30926099 DOI: 10.1016/j.jebdp.2018.05.002

OBJECTIVES: Pulpotomy is the favored treatment for pulp exposure in carious primary teeth. This review aimed to compare the success rates of biodentine (BD) and mineral trioxide aggregate (MTA) pulpotomies in primary molars using meta-analysis (MA) and trial sequential analysis (TSA) and also to assess the quality of the results by Grading of Recommendations, Assessment, Development and Evaluation (GRADE).
METHODS: PubMed, EBSCOhost, and Scopus databases were searched. Additional searching was performed in clinical trial registry, reference lists of systematic reviews, and textbooks. Randomized clinical trials (RCTs) published in the English language through October 2017 comparing the success of pulpotomies in vital primary molars with a follow-up of at least 6 months were selected. Study selection, data extraction, and risk of bias assessment were performed. MA by random effects model, TSA, and GRADE were performed.
RESULTS: Eight RCTs (n = 474) were included. Two RCTs had low risk of bias. No significant difference was observed between MTA and BD in clinical success at 6 months (risk ratio [RR], 1.00; 95% confidence interval [95% CI], 0.97-1.02; I2 = 0%), 12 months (RR, 1.00; 95% CI, 0.96-1.05; I2 = 0%), and 18 months (RR, 1.00; 95% CI, 0.93-1.08; I2 = 0%). No difference was observed in radiographic success at follow-up of 6 months (RR, 0.99; 95% CI, 0.96-1.02; I2 = 0%), 12 months (RR, 1.02; 95% CI, 0.47-2.21; I2 = 0%), and 18 months (RR, 1.02; 95% CI, 0.91-1.15; I2 = 0%). TSA indicated lack of firm evidence for the results of the meta-analytic outcomes on clinical and radiographic success. GRADE assessed the evidence from the MA comparing the effect of MTA and BD in pulpotomy to be of low quality.
CONCLUSION: BD and MTA have similar clinical and radiographic success rates based on limited and low-quality evidence. Future high-quality RCTs between MTA and BD is required to confirm the evidence.

Matched MeSH terms: Calcium Compounds
Exposure to Pb-halide perovskite nanoparticles can deliver bioavailable Pb but does not alter endogenous gut microbiota in zebrafish

Patsiou D, Del Rio-Cubilledo C, Catarino AI, Summers S, Mohd Fahmi A, Boyle D, et al.

Sci Total Environ, 2020 May 01;715:136941.
PMID: 32041050 DOI: 10.1016/j.scitotenv.2020.136941

Lead-halide perovskite nanoparticles (NPs) are a new technology, and investigation of toxicity is of considerable importance due to the potential lead (Pb) release into the environment. The aim of the study was to investigate aqueous and dietary toxicity of Pb-halide perovskite NP and Pb in zebrafish Danio rerio. Perovskite NP toxicity was evaluated in zebrafish by mortality, gene expression, histopathology, and phylogenetic analysis of gut microbiota. Zebrafish larvae were exposed to five Pb-halide perovskite NPs in parallel with Pb(NO3)2 exposures, and zebrafish adults were exposed to the three perovskite NPs that caused the strongest effect and Pb(NO3)2. No median lethal concentration (LC50) was observed for zebrafish larvae exposed to up to 200 mg/L of perovskite NPs for 96 h. Mortality, metallothionein 2 (mt2) and δ-aminolevulinic acid dehydratase (ala-d) gene expression (24-h exposure) in zebrafish larvae after aqueous perovskite NPs exposures did not differ from total Pb concentration - response curves. The lack of differences in mortality and gene expression between perovskite NPs and soluble Pb after aqueous exposure suggest that toxicity from perovskite NPs can be attributed to bioavailable Pb rather than nano-specific effects. Induction of mt2 and reduction of ala-d expression levels in liver tissues showed Pb bioavailability after 2-d and 4-d dietary exposure to perovskite-spiked feeds. Changes in gut microbiota of adult zebrafish were detected after 14-d exposure to Pb-spiked food, but no changes were detected from perovskite-NP spiked food. The phylogenetic analysis identified different microbiome profiles of Pb-fed fish compared to perovskite-fed fish suggesting a different mechanism of toxicity. Exposure to Pb-halide perovskite NPs led to absorption of Pb likely from release of Pb ions rather than absorption of NPs. Pb-halide perovskite NPs can release bioavailable Pb and this needs to be considered during the development of this technology.

Matched MeSH terms: Calcium Compounds
Investigation of trace inorganic elements in street doses of heroin

Chan KW, Tan GH, Wong RC

Sci Justice, 2013 Mar;53(1):73-80.
PMID: 23380066 DOI: 10.1016/j.scijus.2012.08.004

Sixteen trace elements found in 309 street heroin samples, piped water and contaminated water were determined using inductively coupled plasma-mass spectrometry. All the street heroin samples were found to contain high levels of sodium, a reflection of the use of sodium bicarbonate during heroin synthesis. Additionally, this element was also found to be one of the potential contaminants acquired from the piped water. Calcium could be derived from lime while iron, aluminum and zinc could have come from the metallic container used in the processing/cutting stage. The levels of these elements remained low in the heroin and it could be due to the dilution effects from the addition of adulterants. Statistical validation was performed with six links of related heroin samples using principal component analysis to find the best pretreatment for sample classification. It was obtained that normalization followed by fourth root showed promising results with 8% errors in the sample clustering. The technique was then applied to the case samples. Finally, the result suggested that the case samples could have originated from at least two major groups respectively showing unique elemental profiles at the street level.

Matched MeSH terms: Calcium Compounds
Fulltext Management of Perforating Idiopathic Internal Root Resorption

Abdullah D, Eziana Hussein F, Abd Ghani H

Iran Endod J, 2017;12(2):257-260.
PMID: 28512497 DOI: 10.22037/iej.2017.50

This case report describes the endodontic treatment of an idiopathic perforated internal root resorption. A 24-year-old male Malay patient presented with internal root resorption of two of his anterior teeth. The medical history was non-contributory and he had no history of traumatic injury or orthodontic treatment. Cone-beam computed tomography (CBCT) determined the nature, location and severity of the resorptive lesion. Non-surgical root canal treatment of tooth #22 and combined non-surgical and surgical approach for tooth #11 were carried out using mineral trioxide aggregate (MTA) as the filling material. The clinical and radiographic examination three years after completion of treatment revealed evidences of periapical healing. The appropriate diagnosis and the treatment of internal root resorption allowed good healing of these lesions and maintained the tooth in function for as long as possible.

Matched MeSH terms: Calcium Compounds
Synthesis, mechanical properties, and in vitro biocompatibility with osteoblasts of calcium silicate-reduced graphene oxide composites

Mehrali M, Moghaddam E, Shirazi SF, Baradaran S, Mehrali M, Latibari ST, et al.

ACS Appl Mater Interfaces, 2014 Mar 26;6(6):3947-62.
PMID: 24588873 DOI: 10.1021/am500845x

Calcium silicate (CaSiO3, CS) ceramics are promising bioactive materials for bone tissue engineering, particularly for bone repair. However, the low toughness of CS limits its application in load-bearing conditions. Recent findings indicating the promising biocompatibility of graphene imply that graphene can be used as an additive to improve the mechanical properties of composites. Here, we report a simple method for the synthesis of calcium silicate/reduced graphene oxide (CS/rGO) composites using a hydrothermal approach followed by hot isostatic pressing (HIP). Adding rGO to pure CS increased the hardness of the material by ∼40%, the elastic modulus by ∼52%, and the fracture toughness by ∼123%. Different toughening mechanisms were observed including crack bridging, crack branching, crack deflection, and rGO pull-out, thus increasing the resistance to crack propagation and leading to a considerable improvement in the fracture toughness of the composites. The formation of bone-like apatite on a range of CS/rGO composites with rGO weight percentages ranging from 0 to 1.5 has been investigated in simulated body fluid (SBF). The presence of a bone-like apatite layer on the composite surface after soaking in SBF was demonstrated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The biocompatibility of the CS/rGO composites was characterized using methyl thiazole tetrazolium (MTT) assays in vitro. The cell adhesion results showed that human osteoblast cells (hFOB) can adhere to and develop on the CS/rGO composites. In addition, the proliferation rate and alkaline phosphatase (ALP) activity of cells on the CS/rGO composites were improved compared with the pure CS ceramics. These results suggest that calcium silicate/reduced graphene oxide composites are promising materials for biomedical applications.

Matched MeSH terms: Calcium Compounds/chemistry*
Biodiesel production via transesterification of palm olein using waste mud crab (Scylla serrata) shell as a heterogeneous catalyst

Boey PL, Maniam GP, Hamid SA

Bioresour Technol, 2009 Dec;100(24):6362-8.
PMID: 19666218 DOI: 10.1016/j.biortech.2009.07.036

A recent rise in crab aquaculture activities has intensified the generation of waste shells. In the present study, the waste shells were utilized as a source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shell is calcium carbonate which transformed into calcium oxide when activated above 700 degrees C for 2 h. Parametric studies have been investigated and optimal conditions were found to be methanol/oil mass ratio, 0.5:1; catalyst amount, 5 wt.%; reaction temperature, 65 degrees C; and a stirring rate of 500 rpm. The waste catalyst performs equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to 11 times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity.

Matched MeSH terms: Calcium Compounds/chemistry
Selection of metal oxides in the preparation of rice husk ash (RHA)/CaO sorbent for simultaneous SO2 and NO removal

Dahlan I, Lee KT, Kamaruddin AH, Mohamed AR

J Hazard Mater, 2009 Jul 30;166(2-3):1556-9.
PMID: 19147280 DOI: 10.1016/j.jhazmat.2008.12.028

In this work, the removal of SO(2) and NO from simulated flue gas from combustion process was investigated in a fixed-bed reactor using rice husk ash (RHA)/CaO-based sorbent. Various metal precursors were used in order to select the best metal impregnated over RHA/CaO sorbents. The results showed that RHA/CaO sorbents impregnated with CeO(2) had the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO(2) and NO. Infrared spectroscopic results indicated the formation of both sulfate (SO(4)(2-)) and nitrate (NO(3)(-)) species due to the catalytic role played by CeO(2). Apart from that, the catalytic activity of the RHA/CaO/CeO(2) sorbent was found to be closely related to its physical properties (specific surface area, total pore volume and average pore diameter).

Matched MeSH terms: Calcium Compounds/chemistry*
The Malaysian Clinical Guidance on the management of postmenopausal osteoporosis, 2012: a summary

Yeap SS, Hew FL, Lee JK, Goh EM, Chee W, Mumtaz M, et al.

Int J Rheum Dis, 2013 Feb;16(1):30-40.
PMID: 23441770 DOI: 10.1111/1756-185x.12037

AIM: This Clinical Guidance is aimed to help practitioners assess, diagnose and manage their patients with osteoporosis (OP), using the best available evidence.
METHODS: A literature search using PubMed (MEDLINE) and The Cochrane Library identified all relevant articles on OP and its assessment, diagnosis and treatment, from 2005, to update from the previous edition published in 2006. The studies were assessed and the level of evidence assigned; for each statement, studies with the highest level of evidence were used to frame the recommendation.
RESULTS: This article summarizes the diagnostic and treatment pathways for OP, highlighting the new data that have changed the way we assess and treat OP. Instead of starting treatment based on bone mineral density alone, there has been a move to assessing 10-year fracture risk before treatment, using tools such as the Fracture Risk Assessment Tool (FRAX). There has been a re-evaluation on calcium supplementation and more emphasis on the importance of vitamin D. There has been concern about the potential adverse effects of the long-term usage of bisphosphonates, which we have discussed fully. New drugs that have been licensed since 2006 in Malaysia have been included.
CONCLUSIONS: Adequate intake of calcium (1000 mg from both diet and supplements) and vitamin D (800 IU) daily remain important in the treatment of OP. However, in confirmed OP, pharmacological therapy with anti-resorptives is the mainstay of treatment. Patients need to be regularly assessed while on medication and treatment adjusted as required.

Matched MeSH terms: Calcium Compounds/administration & dosage
Investigating the addition of SiO₂-CaO-ZnO-Na₂O-TiO₂ bioactive glass to hydroxyapatite: Characterization, mechanical properties and bioactivity

Yatongchai C, Placek LM, Curran DJ, Towler MR, Wren AW

J Biomater Appl, 2015 Nov;30(5):495-511.
PMID: 26116020 DOI: 10.1177/0885328215592866

Hydroxyapatite (Ca10(PO4)6(OH)2) is widely investigated as an implantable material for hard tissue restoration due to its osteoconductive properties. However, hydroxyapatite in bulk form is limited as its mechanical properties are insufficient for load-bearing orthopedic applications. Attempts have been made to improve the mechanical properties of hydroxyapatite, by incorporating ceramic fillers, but the resultant composite materials require high sintering temperatures to facilitate densification, leading to the decomposition of hydroxyapatite into tricalcium phosphate, tetra-calcium phosphate and CaO phases. One method of improving the properties of hydroxyapatite is to incorporate bioactive glass particles as a second phase. These typically have lower softening points which could possibly facilitate sintering at lower temperatures. In this work, a bioactive glass (SiO2-CaO-ZnO-Na2O-TiO2) is incorporated (10, 20 and 30 wt%) into hydroxyapatite as a reinforcing phase. X-ray diffraction confirmed that no additional phases (other than hydroxyapatite) were formed at a sintering temperature of 560 ℃ with up to 30 wt% glass addition. The addition of the glass phase increased the % crystallinity and the relative density of the composites. The biaxial flexural strength increased to 36 MPa with glass addition, and there was no significant change in hardness as a function of maturation. The pH of the incubation media increased to pH 10 or 11 through glass addition, and ion release profiles determined that Si, Na and P were released from the composites. Calcium phosphate precipitation was encouraged in simulated body fluid with the incorporation of the bioactive glass phase, and cell culture testing in MC-3T3 osteoblasts determined that the composite materials did not significantly reduce cell viability.

Matched MeSH terms: Calcium Compounds/chemistry*
Fulltext Postoperative assessment of diode laser zinc oxide eugenol and mineral trioxide aggregate pulpotomy procedures in children: A comparative clinical study

Pratima B, Chandan GD, Nidhi T, Nitish I, Sankriti M, Nagaveni S, et al.

J Indian Soc Pedod Prev Dent, 2018 9 25;36(3):308-314.
PMID: 30246755 DOI: 10.4103/JISPPD.JISPPD_1132_17

Aim: The present study is an attempt to compare and evaluate postoperative assessment of diode laser zinc oxide eugenol (ZOE) pulpotomy and diode laser mineral trioxide aggregate (MTA) pulpotomy procedures in children.
Materials and Methods: Forty carious primary molars indicated for pulpotomy within the age group of 4-9 years were selected and divided into two groups of 20 each using simple randomization, Group 1: Diode laser MTA and Group 2: Diode laser ZOE pulpotomy. The teeth were evaluated clinically for 1 year at 3, 6, and 12 months interval and radiologically for 6 and 12 months.
Results: Clinically and radiographically, 100% teeth treated with diode laser MTA and 94% treated with diode laser ZOE were considered successful after 12-month follow-up interval. No significant difference was seen between two groups.
Conclusion: Despite the success rate, the cost factor of diode laser and MTA could be the limiting factor in its judicious use in pulpotomy procedure.

Matched MeSH terms: Calcium Compounds/therapeutic use*
Current intervention strategies for the microbial safety of sprouts

Sikin AM, Zoellner C, Rizvi SS

J Food Prot, 2013 Dec;76(12):2099-123.
PMID: 24290689 DOI: 10.4315/0362-028X.JFP-12-437

Sprouts have gained popularity worldwide due to their nutritional values and health benefits. The fact that their consumption has been associated with numerous outbreaks of foodborne illness threatens the $250 million market that this industry has established in the United States. Therefore, sprout manufacturers have utilized the U.S. Food and Drug Administration recommended application of 20,000 ppm of calcium hypochlorite solution to seeds before germination as a preventative method. Concentrations of up to 200 ppm of chlorine wash are also commonly used on sprouts. However, chlorine-based treatment achieves on average only 1- to 3-log reductions in bacteria and is associated with negative health and environmental issues. The search for alternative strategies has been widespread, involving chemical, biological, physical, and hurdle processes that can achieve up to 7-log reductions in bacteria in some cases. The compilation here of the current scientific data related to these techniques is used to compare their efficacy for ensuring the microbial safety of sprouts and their practicality for commercial producers. Of specific importance for alternative seed and sprout treatments is maintaining the industry-accepted germination rate of 95% and the sensorial attributes of the final product. This review provides an evaluation of suggested decontamination technologies for seeds and sprouts before, during, and after germination and concludes that thermal inactivation of seeds and irradiation of sprouts are the most practical stand-alone microbial safety interventions for sprout production.

Matched MeSH terms: Calcium Compounds/pharmacology
Rice husk ash sorbent doped with copper for simultaneous removal of SO2 and NO: optimization study

Lau LC, Lee KT, Mohamed AR

J Hazard Mater, 2010 Nov 15;183(1-3):738-45.
PMID: 20724075 DOI: 10.1016/j.jhazmat.2010.07.088

In order to reduce the negative impact of coal utilization for energy generation, the pollutants present in the flue gas of coal combustion such as sulfur dioxide (SO(2)) and nitrogen oxide (NO) must be effectively removed before releasing to the atmosphere. Thus in this study, sorbent prepared from rice husk ash that is impregnated with copper is tested for simultaneous removal of SO(2) and NO from simulated flue gas. The effect of various sorbent preparation parameters; copper loading, RHA/CaO ratio, hydration period and NaOH concentration on the sorbent desulfurization/denitrification capacity was studied using Design-Expert Version 6.0.6 software. Specifically, Central Composite Design (CCD) coupled with Response Surface Method (RSM) was used. Significant individual parameters that affect the sorbent capacity are copper loading and NaOH concentration. Apart from that, interaction between the following parameters was also found to have significant effect; copper loading, RHA/CaO ratio and NaOH concentration. The optimum sorbent preparation condition for this study was found to be 3.06% CuO loading, RHA/CaO ratio of 1.41, 8.05 h of hydration period and NaOH concentration of 0.80 M. Sorbent characterization using SEM, XRD and surface area analysis were used to describe the effect of sorbent preparation parameters on the desulfurization/denitrification activity.

Matched MeSH terms: Calcium Compounds
Feasibility study on the utilization of rubber latex effluent for producing bacterial biopolymers

Tang SN, Fakhru'l-Razi A, Hassan MA, Karim MI

Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):411-6.
PMID: 10595441

Rubber latex effluent is a polluting source that has a high biochemical oxygen demand (BOD). It is estimated that about 100 million liters of effluent are discharged daily from rubber processing factories. Utilization of this effluent such as the use of a coupled system not only can reduce the cost of treatment but also yield a fermentation feedstock for the production of bioplastic. This study initially was carried out to increase the production of organic acids by anaerobic treatment of rubber latex effluent. It was found that through anaerobic treatment the concentration of organic acids did not increase. Consequently, separation of organic acids from rubber latex effluent by anion exchange resin was examined as a preliminary study of recovering acetic and propionic acids. However, the suspended solids (SS) content in the raw effluent was rather high which partially blocked the ion-exchange columns. Lime was used to remove the SS in the rubber latex effluent. After the lime precipitation process, organic acids were found to adsorb strongly onto the anion exchange resin. Less adsorption of organic acids onto the resin was observed before the lime precipitation. This was probably due to more sites being occupied by colloidal particles on the resin thus inhibiting the adsorption of organic acids. The initial concentration of organic acids in the raw effluent was 3.9 g/L. After ion exchange, the concentration of the organic acids increased to 27 g/L, which could be utilized for production of polyhydroxyalkanoates (PHA). For PHA accumulation stage, concentrated rubber latex effluent obtained from ion exchange resins and synthetic acetic acid were used as the carbon source. Quantitative analyses from fed batch culture via HPLC showed that the accumulation of PHA in Alcaligenes eutrophus was maximum with a concentration of 1.182 g/L when cultivated on synthetic acetic acid, corresponding to a yield of 87% based on its cell dry weight. The dry cell weight increased from 0.71 to 1.67 g/L. On the other hand, using concentrated rubber latex effluent containing acetic and propionic acids resulted in reduced PHA content by dry weight (14%) but the dry cell weight increased from 0.49 to 1.30 g/L. The results clearly indicated that the cells grow well in rubber latex effluent but no PHA was accumulated. This could be due to the high concentration of propionic acid in culture broth or other factors such as heavy metals. Thus further work is required before rubber latex effluent can be utilized as a substrate for PHA production industrially.

Matched MeSH terms: Calcium Compounds

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