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.
Batu Reput’ is primary sediment mineral and abundantly found in Perlis. Perlis is one of the major producers of ‘Batu Reput’ in Malaysia that content large deposit of high-purity dolomite [CaMg (CO3)2]. Pure samples of ‘Batu Reput’ recently explored in the Koperasi Rimba Mas Padang Besar Quarry were investigated for their physical, chemical and mineralogical composition. SEM and XRD analysis methods were applied. The potential of ‘Batu Reput’ as a raw material in fertilizer production was investigated in this paper.
Many attempts have been focused in the past on preparing of synthetic E-tricalcium (E-TCP), which being employed as bone substitute due to its biocompatibility and resorbability. Low temperature synthesize such as sol-gel method become popular due to the high product purity and homogenous composition. Sol-gel method is less economical towards commercialization because the cost of raw materials and the yield of the product that can be achieved. This paper describes the synthesis of ETCP via mixing of CaCO3 and H3PO4 followed by calcinations process at 750qC – 1050qC. X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), fourier transformation infra-red (FTIR) were used for characterization and evaluation of the phase composition, morphology, particle size and thermal behavior of the product. E-TCP phase start to occur after calcinations at 750qC.
Some cortical bone specimens from the femurs of adult cows and sea coral of Porites species were studied by using Fourier Transform Infrared Spectroscopy, FTIR. Carbonate were shown to be present by indication of C-O stretch found between 1510-1410 cm -1 in both cortical bone and Porites. Based on the comparison of the relative intensity of CO3 2- bands with respect to the PO4 3- bands, peak intensity of Porites was found to be higher than peak intensity of cortical bone at carbonate band. This explains that Porites skeleton is made up of CaCO3 while bone consists of a mineral, hydroxyapatite Ca5(PO4)3OH with the present of carbonate ions, typically from 3 to 7 wt%.
OBJECTIVE: To assess bone mineral density (BMD) changes in patients with systemic lupus erythematosus (SLE) undergoing longterm therapy with corticosteroids (CS) while taking calcium, calcitriol, or alendronate. The primary endpoint was BMD changes at 2 years.
METHODS: Premenopausal SLE patients were randomized into 3 groups according to medication: calcium carbonate 500 mg bd (calcium alone), calcitriol 0.25 microg bd plus calcium carbonate 500 mg bd (calcitriol + calcium), and alendronate 70 mg/week plus calcium carbonate 500 mg bd (alendronate + calcium). BMD was measured at baseline and at the end of the first and second years.
RESULTS: Ninety-eight patients were recruited. There were 33 patients taking calcium alone, 33 calcitriol + calcium, and 32 alendronate + calcium. On randomization, median duration of CS use was 2.5 years (range 0-20 yrs). Seventy-seven patients (78.6%) completed the study (23 taking calcium alone, 27 calcitriol + calcium, 27 alendronate + calcium). There were no significant differences in mean CS dosages among the 3 groups at the time of BMD measurements. After 2 years, there were no significant changes in BMD in the calcium-alone and calcitriol + calcium groups, apart from a 0.93% (p < 0.001) reduction in total hip BMD in the calcium-alone group. In contrast, the alendronate + calcium group showed significant increases in BMD of 2.69% (p < 0.001) in the lumbar spine and 1.41% (p < 0.001) in total hip.
CONCLUSION: Both calcium alone and calcitriol + calcium preserved lumbar spine BMD in premenopausal patients with SLE taking longterm CS at 2 years, whereas alendronate + calcium led to increases in BMD in lumbar spine and total hip. Premenopausal women taking CS should be considered for osteoporosis prophylaxis.
Study site: Outpatient clinics in 2 teaching hospitals in Kuala Lumpur, Malaysia
β-tricalcium phosphate (β-TCP) powders were synthesized by using various particles sizes (40 nm – 780 μm) calcium carbonate (CaCO3) and phosphoric acid (H3PO4) at room temperature (25 ˚C). The synthesized powders were characterized by using X-Ray Diffraction (XRD) method. The purity of β-TCP powders were determined from XRD pattern while the crystallite size of β-TCP powders were calculated by using Scherrer equation. Results shows that the purity of β-TCP powders were ranged from 20.33 % to 81.94 % while the crystallite size of β- TCP powders were ranged from 0.04391 μm to 0.06751 μm. From this work, particle size of CaCO3 will influenced the purity but not the mean crystallite size of synthesized β-TCP.
Groundwater is the prime source of freshwater in most small islands. A detailed groundwater and seawater chemistry study was undertaken from March 2006 to January 2007 to examine the evolution of groundwater in the shallow aquifer of Manukan Island, Sabah, Malaysia. Coastal groundwater aquifers especially for small islands are often exposed to heavy pumping and consequently to risks of seawater intrusion. Major ion chemistry analysis showed that the groundwater quality of the island experienced changes attributed to seawater intrusion. The groundwater has undergone a compositional change from Ca-rich to Na-rich which can be explained mostly by simple mixing process and cation exchange process. From the PHREEQC simulation model, calcite, dolomite and aragonite solubility showed positive mean values (0.65; 1.11; 0.51, respectively) of the saturation indices (SI) indicating supersaturation which attributed from the simple mixing and eventually cation exchange process. This information is important in protecting and remediating the disturbed aquifer situation.
In this study, dynamic vulcanization process was used to improve the thermal properties of calcium carbonate filled composites. The composites were prepared using a Z-blade mixer at 180oC and rotor speed 50rpm. Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) techniques were used to analyze the thermal properties of the composites. The vulcanized and unvulcanized PP/EPDM composites were filled by CaCO3 at 0, 10, 20, 30, and 40 %wt. Meanwhile, thermogravimetric analysis indicates that the total weight loss of PP/EPDM/CaCO3 composites decreased with increasing filler loading. Dynamic vulcanized composites have higher thermal stability, while the crystallinity of PP/EPDM/CaCO3 composites were increased as compared to unvulcanized composites. Therefore, the thermal properties were improved by the presence of
dynamic vulcanization process.
Introducing CO2 flux as the carbonate source had an effect on the carbonate content of carbonate apatite (CAp) synthesized by solid state reaction. The reactants were CaCO3 and beta-tricalcium phosphate (β-TCP) and the heat treatment in air was performed at 1250ºC followed by instant cooling in CO2 flux for temperatures ranging from 800ºC room temperature (RT) . The influence of CO2 flux at various temperature drop differences in the cooling process (1250ºC RT, 1250ºC–500ºC, 1250ºC–600ºC, 1250ºC–700ºC, and 1250ºC–800ºC) was tested to optimize the carbonation degree and subsequent effects on the physical and mechanical properties of CAp. Thermally treated samples revealed an increasing degree of carbonation, achieving a maximum of 5.2 wt% at the highest (1250ºC RT) and a minimum of 2.7 wt% at the lowest (1250ºC–800ºC) temperature drop differences, respectively. This showed that the carbonate content was correlated with the increase in exposure to CO2 flux. However, consistent compressive strength, tensile strength, density and porosity were observed against increasing temperature drop differences which indicated that the degree of carbonation exerted no influence on the physical and mechanical properties of CAp. This method enabled the synthesis of solid state CAp simply by exposing calcium phosphate mixtures to CO2 flux. It also allowed the control of carbonate content for desired medical applications.
Precipitated calcium carbonate fillers were loaded into the lumen of bleached mixed tropical hardwood pulp using polyethylenimine (PEI) and alum. Our results indicated that the addition of (PEI) increased the degree of loading of precipitated calcium carbonate (PCC) into the lumen of fibers. The degree of loading also increased with the addition of alum together with PEI. The mechanical strengths of the produced lumen loaded paper increased with the addition of PEI and alum. Meanwhile the mechanical strength without alum had slightly increased the mechanical strengths of the paper. Electron micrographs revealed that the PCC fillers were successfully loaded into the lumen of the fibers.
To evaluate the correlation of the intragranular textures on the physical properties of coarse aggregates, four aggregates samples consisting of three granitoid sources and one limestone have been studied. The role played by intragranular textures (mineral assembladge, grain size and grain boundaries) in influencing the physical properties are potentially significant to the fact that such textural variation may complicate the aggregate strength. This study indicates that the aggregates exhibited variation in textural habits. The granitoid aggregates, which is rich with silicate composition has typical heterogranular textures of porphyritic and equigranular grain structures. Whereas the limestone aggregate comprises of bioclast and peloid allochems cemented by micrite and spar. The granitoid aggregates showed better dispersed characters and had extremely interlocking crystal boundaries which have more physical strength compared to a carbonate aggregate.
A study was carried out to optimize the deacidification process for noni (Morinda citrifolia L.) extract using packed column of calcium carbonate. The experiments were based on a 3-level factorial design to study the optimum process of deacidification for M. citrifolia extract. The M. citrifolia extract was treated with CaCO3 packed in different column diameter (20, 25 and 30 mm), height of calcium carbonate (0, 0.5 and 1 cm) and feed rate (10, 30 and 50 ml/min). Physico-chemical characteristics which include pH, titratable acidity, turbidity, total polyphenol content and total soluble solids were measured. Results showed that only pH, titratable acidity and turbidity could be well represented using statistical models. For pH, only the effect of height of CaCO3 was found to be significant. While for titratable acidity and turbidity, effects of diameter column and height of CaCO3 were significant. The optimum conditions for the deacidification of M. citrifolia extract was by using a column diameter of 30 mm, CaCO3 height of 1 cm, and a feed rate of 50 ml/min.
Conventional alginate pellets underwent rapid drug dissolution and loss of multiparticulate characteristics such as aggregation in acidic medium, thereby promoting oral dose dumping. This study aimed to design sustained-release dispersible alginate pellets through rapid in situ matrix dispersion and cross-linking by calcium salts during dissolution. Pellets made of alginate and calcium salts were prepared using a solvent-free melt pelletization technique that prevented reaction between processing materials during agglomeration and allowed such a reaction to occur only in dissolution phase. Drug release was remarkably retarded in acidic medium when pellets were formulated with water-soluble calcium acetate instead of acid-soluble calcium carbonate. Different from calcium salt-free and calcium carbonate-loaded matrices that aggregated or underwent gradual erosion, rapid in situ solvation of calcium acetate in pellets during dissolution resulted in burst of gas bubbles, fast pellet breakup, and dispersion. The dispersed fragments, though exhibiting a larger specific surface area for drug dissolution than intact matrix, were rapidly cross-linked by Ca(2+) from calcium acetate and had drug release retarded till a change in medium pH from 1.2 to 6.8. Being dispersible and pH-dependent in drug dissolution, these pellets are useful as multiparticulate intestinal-specific drug carrier without exhibiting dose dumping tendency of a "single-unit-like" system via pellet aggregation.
Bird surveys were conducted in the Padawan Limestone Area for seven days at each of two study sites, Giam and Danu, from August to December 2008. The purpose of the study was to compare the area's bird species richness and abundance of bird species in other limestone areas and in other forest types. The study also compared the species richness and relative abundance of birds in undisturbed and disturbed areas at both study sites. Twenty mist nets were deployed for 12 hours daily. During this study period, direct observations of birds were also made. In all, 80 species from 34 families were recorded at both sites. At Giam, 120 birds were mist-netted. These birds represented 31 species from 16 families. The direct observations at Giam recorded 13 species from 11 families. In the undisturbed area, 21 species from 13 families were mist-netted, whereas in the disturbed area, 21 species from 10 families were mist-netted. In Danu, a total of 48 birds, representing 25 species from 12 families, were mist-netted. The observations at Danu recorded 34 species from 19 families. Twelve species from 7 families were mist-netted in the undisturbed area, whereas 18 species from 11 families were mist-netted in the disturbed area. Statistical analysis showed that the species diversity index differed significantly between undisturbed and disturbed areas.
Background: Competence-based curriculum has become the need of medical education to meet the objectives of institutions aiming to produce skilled physicians. To achieve the optimal competence and performance of graduates a number of traditional evaluation exercises have been practiced. Some of these e.g. OSCE although meet the acceptable standard of reliability and validity is the assessment done in a controlled environment. This leaves the room for performance-based assessment in real clinical situation such as mini clinical evaluation exercise (Mini-CEX). To practice and meet the challenges of Mini-CEX it is vital to undertake faculty development program with a comprehensively chalked down Mini-CEX protocol and its objectives to achieve the intended outcome. Objective: To undertake faculty development on Mini-CEX for its feasibility and acceptability as a method of formative assessment to evaluate the clinical competence of trainees in postgraduate program of Otolaryngology and Head-Neck Surgery. Method: 25 trainees from the four classes of master of surgery program of 2009 in Otolaryngology and Head-Neck Surgery (ORL-HNS) undertook Mini-CEX encounters and assessed by 9 supervisors in a 12-week period of study. Faculty development program was carried out through prior lectures deliberating on background, concept and procedure of Mini-CEX followed by demonstrations using video clip of Mini-CEX encounter recorded in own clinical environment. Students were also exposed to similar settings to take up the Mini-CEX encounter without any hesitation. Trainees were assessed in outpatient clinical setting. Program was evaluated for its feasibility and acceptability with respect to patient’s factors, clinical attributes, supervisor and trainee’s performance and their reported level of satisfaction.
Result: Faculty development and trainees orientation in Min-CEX was achieved as feasible and acceptable. Higher rating of satisfaction was reported by majority assessors and trainees as they found Mini-CEX acceptable for formative assessment. Among clinical skills highest rating was received in physical examination and lowest rating in therapeutic skills. Conclusion: A motivated faculty and organized approach towards a comprehensive knowledge on Mini-CEX for its background communication, demonstration of procedure and method to complete the rating forms is the useful guide to adopt Mini-CEX. The faculty and trainees in department of ORL-HNS found Mini-CEX as feasible and acceptable assessment tool to monitor educational activity of postgraduate program through performance-based evaluation in a real clinical situation.
A chemical modifier (acrylic acid) was used to improve the thermal properties of polypropylene/ ethylene propylene diene terpolymer/calcium carbonate (PP/EPDM/CaCO3) composites. Treated
and untreated PP/EPDM composites were filled by CaCO3 at 0, 20 and 40% wt. The composites
were prepared using Z-blade mixer machine at 180oC and 50 rpm of rotor speed. Thermogravimetric
analysis (TGA) and differential scanning calorimetry (DSC) methods were used to analyze the thermal properties of the composites. Thermogravimetric analysis indicated that the total weight loss of PP/EPDM/CaCO3 composites decreased with the increasing filler loading for the treated and untreated composites. Meanwhile, the presence of acrylic acid was found to have increased the thermal stability and crystallinity of PP/EPDM/CaCO3
.
To determine the medication prescribing patterns in hospitalized patients with chronic kidney disease (CKD) in a Malaysian hospital, we prospectively studied a cohort of 600 patients in two phases with 300 patients in each phase. The first phase was carried out from the beginning of February to the end of May 2007, and the second phase was from the beginning of March to the end of June 2008. Patients with CKD who had an estimated creatinine clearance ≤ 50 mL/min and were older than 18 years were included. A data collection form was used to collect data from the patients' medical records and chart review. All systemic medications prescribed during hospitalization were included. The patients were prescribed 5795 medications. During the first phase, the patients were prescribed 2814 medication orders of 176 different medications. The prescriptions were 2981 of 158 medications during the second phase. The mean number of medications in the first and second phases was 9.38 ± 3.63 and 9.94 ± 3.78 respectively (P-value = 0.066). The top five used medications were calcium carbonate, folic acid/vitamin B complex, metoprolol, lovastatin, and ferrous sulfate. The most commonly used medication classes were mineral supplements, vitamins, antianemic preparations, antibacterials, and beta-blocking agents. This study provides an overview of prescription practice in a cohort of hospitalized CKD patients and indicates possible areas of improvement in prescription practice.
Matched MeSH terms: Calcium Carbonate/therapeutic use
Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild.
This study investigates the effects of calcium carbonate (CaCO(3)) nanoparticles on the mechanical and thermal properties and surface morphology of polycaprolactone (PCL)/chitosan nanocomposites. The nanocomposites of PCL/chitosan/CaCO(3) were prepared using a melt blending technique. Transmission electron microscopy (TEM) results indicate the average size of nanoparticles to be approximately 62 nm. Tensile measurement results show an increase in the tensile modulus with CaCO(3) nanoparticle loading. Tensile strength and elongation at break show gradual improvement with the addition of up to 1 wt% of nano-sized CaCO(3). Decreasing performance of these properties is observed for loading of more than 1 wt% of nano-sized CaCO(3). The thermal stability was best enhanced at 1 wt% of CaCO(3) nanoparticle loading. The fractured surface morphology of the PCL/chitosan blend becomes more stretched and homogeneous in PCL/chitosan/CaCO(3) nanocomposite. TEM micrograph displays good dispersion of CaCO(3) at lower nanoparticle loading within the matrix.