Displaying publications 181 - 200 of 238 in total

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  1. The nutritional value of indigenous fruits and vegetables in Sarawak
    Hoe VB, Siong KH
    Asia Pac J Clin Nutr, 1999 Mar;8(1):24-31.
    PMID: 24393732
    The proximate composition including mineral and vitamin contents of 16 fruits and 46 vegetables (leaves, fruits, palm hearts and shoots) of indigenous origin in Sarawak are provided. Fruits like dabai (Canarium odontophyllum), kembayau (Dacryodes rostrata f. cuspidata), durian nyekak (Durio kutejensis) and durian kuning (Durio graveolens) are very nutritious with high values for energy, protein and potassium. Among the vegetables, the protein content of letup (Passiflora foetida), kepayang (Pangium edule) and tubu (Pycnarrhena tumetacta) is high, ranging from 6 to 7%. The range of nutrients among foods of indigenous origin are generally comparable with those of many cultivated species except for vitamin C, which is lower. Teh Kampung (Leucosyke capitellata) leaves are particularly high in magnesium (626 mg/100 g). Some of the indigenous vegetables contain antinutritional factors. Kepayang has very high levels of hydrogen cyanide (1834 µg/g on dry basis) but this poison can be completely evaporated by boiling. Indigenous fruits and vegetables which are pesticide residue free are important food sources for rural populations. Nutritious indigenous fruits and vegetables have the potential to be promoted for wider use, domestication and commercialization.
    Matched MeSH terms: Minerals
  2. Chemical composition of the tiger's milk mushroom, Lignosus rhinocerotis (Cooke) Ryvarden, from different developmental stages
    Lau BF, Abdullah N, Aminudin N
    J Agric Food Chem, 2013 May 22;61(20):4890-7.
    PMID: 23597270 DOI: 10.1021/jf4002507
    The chemical composition of the tiger's milk mushroom (Lignosus rhinocerotis) from different developmental stages, i.e., the fruit body, sclerotium, and mycelium, was investigated for the first time. The fruit body and sclerotium of L. rhinocerotis were rich in carbohydrates and dietary fibers but low in fat. Protein levels in L. rhinocerotis were moderate, and all essential amino acids, except tryptophan, were present. The mycelium contained high levels of potassium, phosphorus, magnesium, riboflavin, and niacin and appreciable amounts of essential fatty acids. The results indicated that the sclerotium of L. rhinocerotis that was used in ethnomedicine was not superior to the fruit body and mycelium with regard to the nutritional content and bioactive constituents. Our findings provide some insights into the selection of appropriate mushroom part(s) of L. rhinocerotis and proper cultivation techniques for the development of new nutraceuticals or dietary supplements.
    Matched MeSH terms: Minerals/analysis
  3. Fulltext Nitrate, ascorbic acid, mineral and antioxidant activities of Cosmos caudatus in response to organic and mineral-based fertilizer rates
    Hassan SA, Mijin S, Yusoff UK, Ding P, Wahab PE
    Molecules, 2012 Jun 28;17(7):7843-53.
    PMID: 22743588 DOI: 10.3390/molecules17077843
    The source and quantity of nutrients available to plants can affect the quality of leafy herbs. A study was conducted to compare quality of Cosmos caudatus in response to rates of organic and mineral-based fertilizers. Organic based fertilizer GOBI (8% N:8% P₂O₅:8% K₂O) and inorganic fertilizer (15% N, 15% P₂O₅, 15% K₂O) were evaluated based on N element rates at 0, 30, 60, 90, 120 kg h⁻¹. Application of organic based fertilizer reduced nitrate, improved vitamin C, antioxidant activity as well as nitrogen and calcium nutrients content. Antioxidant activity and chlorophyll content were significantly higher with increased fertilizer application. Fertilization appeared to enhance vitamin C content, however for the maximum ascorbic acid content, regardless of fertilizer sources, plants did not require high amounts of fertilizer.
    Matched MeSH terms: Minerals/pharmacology*
  4. Effects of freeze-dried Mitsuokella jalaludinii culture and Natuphos(®) phytase supplementation on the performance and nutrient utilisation of broiler chickens
    Lan G, Abdullah N, Jalaludin S, Ho YW
    J Sci Food Agric, 2012 Jan 30;92(2):266-73.
    PMID: 21796639 DOI: 10.1002/jsfa.4570
    Phytate-bound phosphorus (P) in poultry diets is poorly available to chickens. Hence exogenous phytase is often added to their diets. Mitsuokella jalaludinii is a rumen bacterial species that produces high phytase activity. In this study the effects of freeze-dried active M. jalaludinii culture (FD-AMJC) and Natuphos(®) phytase (phytase N) supplementations on the growth performance and nutrient utilisation of broiler chickens fed a low-available P (aP) diet were evaluated.
    Matched MeSH terms: Minerals/blood
  5. Prevalence of vitamin-mineral supplements use and associated factors among young Malaysians
    Al-Naggar RA, Chen R
    Asian Pac J Cancer Prev, 2011;12(4):1023-9.
    PMID: 21790245
    The objective of this study is to determine the prevalence and associated factors of vitamin-mineral supplements use among Management and Science University students. The cross-sectional study protocol was approved by the Ethics and Research Committee and questionnaires were distributed randomly using simple random sampling to students from all faculties and consent was obtained. The data were analyzed using the SPSS version 13. Total number of the participants in this study is 105. More than half of them were female, older than 20 years of age and Malay (58.1%, 61.9 and 61.9% respectively). The prevalence of vitamin-mineral supplement use was 43%, the main reasons being 'to maintain good health' 80%, followed by 'to ensure adequate nutrition' (10.5%). There was a significant positive association with monthly household income and BMI (P=0.039; P=0.048), with significant dependence on race and knowledge about vitamin-mineral supplements (P=0.002). There was a significant difference between medical and health sciences as compared to non-medical and health science faculties (p =0.05). The conclusion is that although the prevalence of vitamin-mineral supplement use among university students is relatively high, many of them do not have accurate information about supplements. Therefore, there is a need to provide them with education and access to scientific and unbiased information.
    Matched MeSH terms: Minerals/administration & dosage*
  6. Application of multivariate statistical techniques for differentiation of ripe banana flour based on the composition of elements
    Alkarkhi AF, Ramli SB, Easa AM
    Int J Food Sci Nutr, 2009;60 Suppl 4:116-25.
    PMID: 19115121 DOI: 10.1080/09637480802609368
    Major (sodium, potassium, calcium, magnesium) and minor elements (iron, copper, zinc, manganese) and one heavy metal (lead) of Cavendish banana flour and Dream banana flour were determined, and data were analyzed using multivariate statistical techniques of factor analysis and discriminant analysis. Factor analysis yielded four factors explaining more than 81% of the total variance: the first factor explained 28.73%, comprising magnesium, sodium, and iron; the second factor explained 21.47%, comprising only manganese and copper; the third factor explained 15.66%, comprising zinc and lead; while the fourth factor explained 15.50%, comprising potassium. Discriminant analysis showed that magnesium and sodium exhibited a strong contribution in discriminating the two types of banana flour, affording 100% correct assignation. This study presents the usefulness of multivariate statistical techniques for analysis and interpretation of complex mineral content data from banana flour of different varieties.
    Matched MeSH terms: Minerals/analysis*
  7. Fulltext Degradation and mineralization of phenol compounds with goethite catalyst and mineralization prediction using artificial intelligence
    Tisa F, Davoody M, Abdul Raman AA, Daud WM
    PLoS One, 2015;10(4):e0119933.
    PMID: 25849556 DOI: 10.1371/journal.pone.0119933
    The efficiency of phenol degradation via Fenton reaction using mixture of heterogeneous goethite catalyst with homogeneous ferrous ion was analyzed as a function of three independent variables, initial concentration of phenol (60 to 100 mg /L), weight ratio of initial concentration of phenol to that of H2O2 (1: 6 to 1: 14) and, weight ratio of initial concentration of goethite catalyst to that of H2O2 (1: 0.3 to 1: 0.7). More than 90 % of phenol removal and more than 40% of TOC removal were achieved within 60 minutes of reaction. Two separate models were developed using artificial neural networks to predict degradation percentage by a combination of Fe3+ and Fe2+ catalyst. Five operational parameters were employed as inputs while phenol degradation and TOC removal were considered as outputs of the developed models. Satisfactory agreement was observed between testing data and the predicted values (R2Phenol = 0.9214 and R2TOC= 0.9082).
    Matched MeSH terms: Minerals/chemistry*
  8. Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands
    Osaki M, Watanabe T, Ishizawa T, Nilnond C, Nuyim T, Shinano T, et al.
    Plant Foods Hum Nutr, 2003;58(2):93-115.
    PMID: 12906350
    Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed in the lowlands of Thailand and Malaysia. The nutrient concentrations in the leaves of plants grown in these type of soils were studied with the aim of developing a nutritional strategy for adapting to such problem soils. In sago and oil palms that were well-adapted to peat soil, the N, P, and K concentrations were the same in the mature leaves, while the Ca, Mg, Na, and Fe concentrations were higher in the mature leaves of the oil palm than of the sago palm. Melastoma malabathricum and Melaleuca cajuputi plants that were well-adapted to low pH soils, peat. and acid sulfate soils were also studied. It was observed that a high amount of Al accumulated in the M. marabathricum leaves, while Al did not accumulate in M. cajuputi leaves. M. cajuputi plants accumulated large amounts of Na in their leaves or stems regardless of the exchangeable Na concentration in the soil, while M. malabathricum that was growing in saline-affected soils excluded Na. Positive relationships between macronutrients were recognized between P and N, between K and N, and between P and K. Al showed antagonistic relationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showed antagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weak antagonistic relationships with Zn, Mn, Cu, and Al.
    Matched MeSH terms: Minerals/analysis*
  9. Geochemical and mineralogical assessment of sedimentary limestone mine waste and potential for mineral carbonation
    Mohd Isha NS, Mohd Kusin F, Ahmad Kamal NM, Syed Hasan SNM, Molahid VLM
    Environ Geochem Health, 2021 May;43(5):2065-2080.
    PMID: 33392897 DOI: 10.1007/s10653-020-00784-z
    This paper attempts to evaluate the mineralogical and chemical composition of sedimentary limestone mine waste alongside its mineral carbonation potential. The limestone mine wastes were recovered as the waste materials after mining and crushing processes and were analyzed for mineral, major and trace metal elements. The major mineral composition discovered was calcite (CaCO3) and dolomite [CaMg(CO3)2], alongside other minerals such as bustamite [(Ca,Mn)SiO3] and akermanite (Ca2MgSi2O7). Calcium oxide constituted the greatest composition of major oxide components of between 72 and 82%. The presence of CaO facilitated the transformation of carbon dioxide into carbonate form, suggesting potential mineral carbonation of the mine waste material. Geochemical assessment indicated that mean metal(loid) concentrations were found in the order of Al > Fe > Sr > Pb > Mn > Zn > As > Cd > Cu > Ni > Cr > Co in which Cd, Pb and As exceeded some regulatory guideline values. Ecological risk assessment demonstrated that the mine wastes were majorly influenced by Cd as being classified having moderate risk. Geochemical indices depicted that Cd was moderately accumulated and highly enriched in some of the mine waste deposited areas. In conclusion, the limestone mine waste material has the potential for sequestering CO2; however, the presence of some trace metals could be another important aspect that needs to be considered. Therefore, it has been shown that limestone mine waste can be regarded as a valuable feedstock for mineral carbonation process. Despite this, the presence of metal(loid) elements should be of another concern to minimize potential ecological implication due to recovery of this waste material.
    Matched MeSH terms: Minerals/analysis
  10. Development of granular sludge for textile wastewater treatment
    Muda K, Aris A, Salim MR, Ibrahim Z, Yahya A, van Loosdrecht MC, et al.
    Water Res, 2010 Aug;44(15):4341-50.
    PMID: 20580402 DOI: 10.1016/j.watres.2010.05.023
    Microbial granular sludge that is capable to treat textile wastewater in a single reactor under intermittent anaerobic and aerobic conditions was developed in this study. The granules were cultivated using mixed sewage and textile mill sludge in combination with anaerobic granules collected from an anaerobic sludge blanket reactor as seed. The granules were developed in a single sequential batch reactor (SBR) system under alternating anaerobic and aerobic condition fed with synthetic textile wastewater. The characteristics of the microbial granular sludge were monitored throughout the study period. During this period, the average size of the granules increased from 0.02 +/- 0.01 mm to 2.3 +/- 1.0 mm and the average settling velocity increased from 9.9 +/- 0.7 m h(-1) to 80 +/- 8 m h(-1). This resulted in an increased biomass concentration (from 2.9 +/- 0.8 g L(-1) to 7.3 +/- 0.9 g L(-1)) and mean cell residence time (from 1.4 days to 8.3 days). The strength of the granules, expressed as the integrity coefficient also improved. The sequential batch reactor system demonstrated good removal of COD and ammonia of 94% and 95%, respectively, at the end of the study. However, only 62% of color removal was observed. The findings of this study show that granular sludge could be developed in a single reactor with an intermittent anaerobic-aerobic reaction phase and is capable in treating the textile wastewater.
    Matched MeSH terms: Minerals/metabolism
  11. Retained Endoscope: An Unexpected but Serious Complication of Hemospray®
    Yii RSL, Chuah KH, Poh KS, Lau PC, Ng KL, Ho SH, et al.
    Dig Dis Sci, 2022 01;67(1):344-347.
    PMID: 33491164 DOI: 10.1007/s10620-021-06835-4
    Matched MeSH terms: Minerals/administration & dosage
  12. Environmental geochemistry of the abandoned Mamut Copper Mine (Sabah) Malaysia
    van der Ent A, Edraki M
    Environ Geochem Health, 2018 Feb;40(1):189-207.
    PMID: 27848090 DOI: 10.1007/s10653-016-9892-3
    The Mamut Copper Mine (MCM) located in Sabah (Malaysia) on Borneo Island was the only Cu-Au mine that operated in the country. During its operation (1975-1999), the mine produced 2.47 Mt of concentrate containing approximately 600,000 t of Cu, 45 t of Au and 294 t of Ag, and generated about 250 Mt of overburden and waste rocks and over 150 Mt of tailings, which were deposited at the 397 ha Lohan tailings storage facility, 15.8 km from the mine and 980 m lower in altitude. The MCM site presents challenges for environmental rehabilitation due to the presence of large volumes of sulphidic minerals wastes, the very high rainfall and the large volume of polluted mine pit water. This indicates that rehabilitation and treatment is costly, as for example, exceedingly large quantities of lime are needed for neutralisation of the acidic mine pit discharge. The MCM site has several unusual geochemical features on account of the concomitant occurrence of acid-forming sulphide porphyry rocks and alkaline serpentinite minerals, and unique biological features because of the very high plant diversity in its immediate surroundings. The site hence provides a valuable opportunity for researching natural acid neutralisation processes and mine rehabilitation in tropical areas. Today, the MCM site is surrounded by protected nature reserves (Kinabalu Park, a World Heritage Site, and Bukit Hampuan, a Class I Forest Reserve), and the environmental legacy prevents de-gazetting and inclusion in these protected area in the foreseeable future. This article presents a preliminary geochemical investigation of waste rocks, sediments, secondary precipitates, surface water chemistry and foliar elemental uptake in ferns, and discusses these results in light of their environmental significance for rehabilitation.
    Matched MeSH terms: Minerals/analysis*
  13. Fulltext Salinity-induced changes in the morphology and major mineral nutrient composition of purslane (Portulaca oleracea L.) accessions
    Alam MA, Juraimi AS, Rafii MY, Hamid AA, Aslani F, Hakim MA
    Biol Res, 2016 Apr 18;49:24.
    PMID: 27090643 DOI: 10.1186/s40659-016-0084-5
    This study was undertaken to determine the effects of varied salinity regimes on the morphological traits (plant height, number of leaves, number of flowers, fresh and dry weight) and major mineral composition of 13 selected purslane accessions. Most of the morphological traits measured were reduced at varied salinity levels (0.0, 8, 16, 24 and 32 dS m(-1)), but plant height was found to increase in Ac1 at 16 dS m(-1) salinity, and Ac13 was the most affected accession. The highest reductions in the number of leaves and number of flowers were recorded in Ac13 at 32 dS m(-1) salinity compared to the control. The highest fresh and dry weight reductions were noted in Ac8 and Ac6, respectively, at 32 dS m(-1) salinity, whereas the highest increase in both fresh and dry weight was recorded in Ac9 at 24 dS m(-1) salinity compared to the control. In contrast, at lower salinity levels, all of the measured mineral levels were found to increase and later decrease with increasing salinity, but the performance of different accessions was different depending on the salinity level. A dendrogram was also constructed by UPGMA based on the morphological traits and mineral compositions, in which the 13 accessions were grouped into 5 clusters, indicating greater diversity among them. A three-dimensional principal component analysis also confirmed the output of grouping from cluster analysis.
    Matched MeSH terms: Minerals/analysis*
  14. Chemical composition and physicochemical properties of green banana (Musa acuminata x balbisiana Colla cv. Awak) flour
    Haslinda WH, Cheng LH, Chong LC, Noor Aziah AA
    Int J Food Sci Nutr, 2009;60 Suppl 4:232-9.
    PMID: 19449278 DOI: 10.1080/09637480902915525
    Flour was prepared from peeled and unpeeled banana Awak ABB. Samples prepared were subjected to analysis for determination of chemical composition, mineral, dietary fibre, starch and total phenolics content, antioxidant activity and pasting properties. In general, flour prepared from unpeeled banana was found to show enhanced nutrition values with higher contents of mineral, dietary fibre and total phenolics. Hence, flour fortified with peel showed relatively higher antioxidant activity. On the other hand, better pasting properties were shown when banana flour was blended with peel. It was found that a relatively lower pasting temperature, peak viscosity, breakdown, final viscosity and setback were evident in a sample blended with peel.
    Matched MeSH terms: Minerals/analysis
  15. Protective effect of magnesium acetyltaurate against NMDA-induced retinal damage involves restoration of minerals and trace elements homeostasis
    Jafri AJA, Arfuzir NNN, Lambuk L, Iezhitsa I, Agarwal R, Agarwal P, et al.
    J Trace Elem Med Biol, 2017 Jan;39:147-154.
    PMID: 27908408 DOI: 10.1016/j.jtemb.2016.09.005
    Glutamate-mediated excitotoxicity involving N-methyl-d-aspartate (NMDA) receptors has been recognized as a final common outcome in pathological conditions involving death of retinal ganglion cells (RGCs). Overstimulation of NMDA receptors results in influx of calcium (Ca) and sodium (Na) ions and efflux of potassium (K). NMDA receptors are blocked by magnesium (Mg). Such changes due to NMDA overstimulation are also associated with not only the altered levels of minerals but also that of trace elements and redox status. Both the decreased and elevated levels of trace elements such as iron (Fe), zinc (Zn), copper (Cu) affect NMDA receptor excitability and redox status. Manganese (Mn), and selenium (Se) are also part of antioxidant defense mechanisms in retina. Additionally endogenous substances such as taurine also affect NMDA receptor activity and retinal redox status. Therefore, the aim of this study was to evaluate the effect of Mg acetyltaurate (MgAT) on the retinal mineral and trace element concentration, oxidative stress, retinal morphology and retinal cell apoptosis in rats after-NMDA exposure. One group of Sprague Dawley rats received intravitreal injection of vehicle while 4 other groups similarly received NMDA (160nmolL(-1)). Among the NMDA injected groups, 3 groups also received MgAT (320nmolL(-1)) as pre-treatment, co-treatment or post-treatment. Seven days after intravitreal injection, rats were sacrificed, eyes were enucleated and retinae were isolated for estimation of mineral (Ca, Na, K, Mg) and trace element (Mn, Cu, Fe, Se, Zn) concentration using Inductively Coupled Plasma (DRC ICP-MS) techniques (NexION 300D), retinal oxidative stress using Elisa, retinal morphology using H&E staining and retinal cell apoptosis using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Intravitreal NMDA injection resulted in increased concentration of Ca (4.6 times, p<0.0001), Mg (1.5 times, p<0.01), Na (3 times, p<0.0001) and K (2.3 times, p<0.0001) compared to vehicle injected group. This was accompanied with significant increase of Ca/Mg and Na/K ratios, 3 and 1.27 times respectively, compared to control group. The trace elements such as Cu, Fe and Zn also showed a significant increase amounting to 3.3 (p<0.001), 2.3 (p<0.0001) and 3 (p<0.0001) times respectively compared to control group. Se was increased by 60% (p<0.005). Pre-treatment with MgAT abolished effect of NMDA on minerals and trace elements more effectively than co- and post-treatment. Similar observations were made for retinal oxidative stress, retinal morphology and retinal cell apoptosis. In conclusion, current study demonstrated the protective effect of MgAT against NMDA-induced oxidative stress and retinal cell apoptosis. This effect of MgAT was associated with restoration of retinal concentrations of minerals and trace elements. Further studies are warranted to explore the precise molecular targets of MgAT. Nevertheless, MgAT seems a potential candidate in the management of diseases involving NMDA-induced excitotoxicity.
    Matched MeSH terms: Minerals/metabolism*
  16. Fulltext Artificial weathering as a function of CO2 injection in Pahang Sandstone Malaysia: investigation of dissolution rate in surficial condition
    Jalilavi M, Zoveidavianpoor M, Attarhamed F, Junin R, Mohsin R
    Sci Rep, 2014;4:3645.
    PMID: 24413195 DOI: 10.1038/srep03645
    Formation of carbonate minerals by CO2 sequestration is a potential means to reduce atmospheric CO2 emissions. Vast amount of alkaline and alkali earth metals exist in silicate minerals that may be carbonated. Laboratory experiments carried out to study the dissolution rate in Pahang Sandstone, Malaysia, by CO2 injection at different flow rate in surficial condition. X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDX), Atomic Absorption Spectroscopy (AAS) and weight losses measurement were performed to analyze the solid and liquid phase before and after the reaction process. The weight changes and mineral dissolution caused by CO2 injection for two hours CO2 bubbling and one week' aging were 0.28% and 18.74%, respectively. The average variation of concentrations of alkaline earth metals in solution varied from 22.62% for Ca(2+) to 17.42% for Mg(2+), with in between 16.18% observed for the alkali earth metal, potassium. Analysis of variance (ANOVA) test is performed to determine significant differences of the element concentration, including Ca, Mg, and K, before and after the reaction experiment. Such changes show that the deposition of alkali and alkaline earth metals and the dissolution of required elements in sandstone samples are enhanced by CO2 injection.
    Matched MeSH terms: Minerals
  17. Medication storage and self-medication behaviour amongst female students in Malaysia
    Ali SE, Ibrahim MI, Palaian S
    Pharm Pract (Granada), 2010 Oct;8(4):226-32.
    PMID: 25126145
    OBJECTIVES:
    The aims of this study are to determine the prevalence, attitudes and behaviours of medication storage and self-medication amongst female students at Universiti Sains Malaysia (USM).

    METHODS:
    A cross-sectional survey was conducted and cluster random sampling technique was used for respondent selection. A pre-piloted questionnaire was administered to female respondents so as to collect the data. Data was analyzed using SPSS version 12 and analysis was conducted using descriptive analysis procedures.

    RESULTS:
    Of the 481 participants (mean age; SD was 22.1; 3.3), 93.1% (n=448) students stated that they stored medicine in their rooms, while 70.7% (n=340) stated that they stopped taking a prescribed medicine without consulting a doctor. The prevalence of self-medication was 80.9% (n=389). The most common reasons for self-medication were related to their knowledge of their ailment and its treatment (58.0%), 14.4% thought it saved time and 8.5% mentioned that medication given by provider was not effective. The most common symptoms were otorhinolaryngology problems (22.5%), followed by respiratory disease (19.6%), Gastro Intestinal Tract (GIT) disease (18.1%) and headache/fever (16.8%). Commonly used medicines were analgesics & antipyretics (30.2%), ear, nose & throat drugs (10.8%), vitamins & minerals (10.8%), GIT drugs (8.5%), anti-infections (7.3%) and herbal medicines (3.5%). Prevalence of medicine storage and self-medication practice is high among educated female students in USM.

    CONCLUSIONS:
    There is a need to educate the students to ensure safe practice by increasing their awareness. Strict policies need to be implemented on the unrestricted availability of medicines so as to prevent the wastage of medicines.
    Matched MeSH terms: Minerals
  18. Fulltext Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs
    Seyyedi M, Mahmud HKB, Verrall M, Giwelli A, Esteban L, Ghasemiziarani M, et al.
    Sci Rep, 2020 Feb 27;10(1):3624.
    PMID: 32107400 DOI: 10.1038/s41598-020-60247-4
    Observations and modeling studies have shown that during CO2 injection into underground carbonate reservoirs, the dissolution of CO2 into formation water forms acidic brine, leading to fluid-rock interactions that can significantly impact the hydraulic properties of the host formation. However, the impacts of these interactions on the pore structure and macroscopic flow properties of host rock are poorly characterized both for the near-wellbore region and deeper into the reservoir. Little attention has been given to the influence of pressure drop from the near-wellbore region to reservoir body on disturbing the ionic equilibrium in the CO2-saturated brine and consequent mineral precipitation. In this paper, we present the results of a novel experimental procedure designed to address these issues in carbonate reservoirs. We injected CO2-saturated brine into a composite core made of two matching grainstone carbonate core plugs with a tight disk placed between them to create a pressure profile of around 250 psi resembling that prevailing in reservoirs during CO2 injection. We investigated the impacts of fluid-rock interactions at pore and continuum scale using medical X-ray CT, nuclear magnetic resonance, and scanning electron microscopy. We found that strong calcite dissolution occurs near to the injection point, which leads to an increase in primary intergranular porosity and permeability of the near injection region, and ultimately to wormhole  formation. The strong heterogeneous dissolution of calcite grains leads to the formation of intra-granular micro-pores. At later stages of the dissolution, the internal regions of ooids become accessible to the carbonated brine, leading to the formation of moldic porosity. At distances far from the injection point, we observed minimal or no change in pore structure, pore roughness, pore populations, and rock hydraulic properties. The pressure drop of 250 psi slightly disturbed the chemical equilibrium of the system, which led to minor precipitation of sub-micron sized calcite crystals but due to the large pore throats of the rock, these deposits had no measurable impact on rock permeability. The trial illustrates that the new procedure is valuable for investigating fluid-rock interactions by reproducing the geochemical consequences of relatively steep pore pressure gradients during CO2 injection.
    Matched MeSH terms: Minerals
  19. Fucoidan Ameliorates Renal Injury-Related Calcium-Phosphorus Metabolic Disorder and Bone Abnormality in the CKD-MBD Model Rats by Targeting FGF23-Klotho Signaling Axis
    Liu BH, Chong FL, Yuan CC, Liu YL, Yang HM, Wang WW, et al.
    Front Pharmacol, 2020;11:586725.
    PMID: 33708111 DOI: 10.3389/fphar.2020.586725
    Background: Recently, chronic kidney disease (CKD)-mineral and bone disorder (MBD) has become one of common complications occurring in CKD patients. Therefore, development of a new treatment for CKD-MBD is very important in the clinic. In China, Fucoidan (FPS), a natural compound of Laminaria japonica has been frequently used to improve renal dysfunction in CKD. However, it remains elusive whether FPS can ameliorate CKD-MBD. FGF23-Klotho signaling axis is reported to be useful for regulating mineral and bone metabolic disorder in CKD-MBD. This study thereby aimed to clarify therapeutic effects of FPS in the CKD-MBD model rats and its underlying mechanisms in vivo and in vitro, compared to Calcitriol (CTR). Methods: All male rats were divided into four groups: Sham, CKD-MBD, FPS and CTR. The CKD-MBD rat models were induced by adenine administration and uninephrectomy, and received either FPS or CTR or vehicle after induction of renal injury for 21 days. The changes in parameters related to renal dysfunction and renal tubulointerstitial damage, calcium-phosphorus metabolic disorder and bone lesion were analyzed, respectively. Furthermore, at sacrifice, the kidneys and bone were isolated for histomorphometry, immunohistochemistry and Western blot. In vitro, the murine NRK-52E cells were used to investigate regulative actions of FPS or CTR on FGF23-Klotho signaling axis, ERK1/2-SGK1-NHERF-1-NaPi-2a pathway and Klotho deficiency. Results: Using the modified CKD-MBD rat model and the cultured NRK-52E cells, we indicated that FPS and CTR alleviated renal dysfunction and renal tubulointerstitial damage, improved calcium-phosphorus metabolic disorder and bone lesion, and regulated FGF23-Klotho signaling axis and ERK1/2-SGK1-NHERF-1-NaPi-2a pathway in the kidney. In addition, using the shRNA-Klotho plasmid-transfected cells, we also detected, FPS accurately activated ERK1/2-SGK1-NHERF-1-NaPi-2a pathway through Klotho loss reversal. Conclusion: In this study, we emphatically demonstrated that FPS, a natural anti-renal dysfunction drug, similar to CTR, improves renal injury-related calcium-phosphorus metabolic disorder and bone abnormality in the CKD-MBD model rats. More importantly, we firstly found that beneficial effects in vivo and in vitro of FPS on phosphorus reabsorption are closely associated with regulation of FGF23-Klotho signaling axis and ERK1/2-SGK1-NHERF-1-NaPi-2a pathway in the kidney. This study provided pharmacological evidences that FPS directly contributes to the treatment of CKD-MBD.
    Matched MeSH terms: Minerals
  20. Re-visiting pH-adjusted potassium to avoid hypokalemic crisis during management of diabetic ketoacidosis: A conceptual framework
    Usman A, Shaikh MF, Dujaili JA, Mustafa N, Gan SH
    Diabetes Metab Syndr, 2021 Mar 05;15(2):573-580.
    PMID: 33706189 DOI: 10.1016/j.dsx.2021.03.001
    BACKGROUND AND AIMS: Diabetic ketoacidosis (DKA) treatment guidelines recommend to initiate potassium-replacement when serum potassium (SK) drops within normal range, and to withhold insulin if SK is below normal. Despite strict recommendations, hypokalemia is frequently observed in DKA.

    METHODS: Scientific literature was thoroughly searched to find 1) DKA treatment guidelines, 2) studies reporting hypokalemia in DKA, 3) and literature elaborating mechanisms involved in hypokalemia.

    RESULTS: Acidosis affects SK and its regulators including insulin, catecholamines and aldosterone. Current conceptual framework is an argument to gauge the degree of hypokalemia before it strikes DKA patients utilizing SK level after adjusting it with pH. Suggested approach will reduce hypokalemia risk and its associated complications. The nomogram calculates pH-adjusted potassium and expected potassium loss. It also ranks hypokalemia associated risk, and proposes the potassium-replacement rate over given time period. The differences between current DKA treatment guidelines and proposed strategy are also discussed. Moreover, reasons and risk of hyperkalemia due to early initiation of potassium replacement and remedial actions are debated.

    CONCLUSION: In light of proposed strategy, utilizing the nomogram ensures reduced incidence of hypokalemia in DKA resulting in improved clinical and patient outcomes. Pharmacoeconomic benefits can also be expected when avoiding hypokalemia ensures early discharge.

    Matched MeSH terms: Minerals
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