Displaying publications 1 - 20 of 240 in total

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  1. Abubakari F, Mesjasz-Przybyłowicz J, Przybyłowicz WJ, van der Ent A
    AoB Plants, 2020 Dec;12(6):plaa058.
    PMID: 33408845 DOI: 10.1093/aobpla/plaa058
    The Malaysian state of Sabah on the Island of Borneo has recently emerged as a global hotspot of nickel hyperaccumulator plants. This study focuses on the tissue-level distribution of nickel and other physiologically relevant elements in hyperaccumulator plants with distinct phylogenetical affinities. The roots, old stems, young stems and leaves of Flacourtia kinabaluensis (Salicaceae), Actephila alanbakeri (Phyllanthaceae), Psychotria sarmentosa (Rubiaceae) and young stems and leaves of Glochidion brunneum (Phyllanthaceae) were studied using nuclear microprobe (micro-PIXE and micro-BS) analysis. The tissue-level distribution of nickel found in these species has the same overall pattern as in most other hyperaccumulator plants studied previously, with substantial enrichment in the epidermal cells and in the phloem. This study also revealed enrichment of potassium in the spongy and palisade mesophyll of the studied species. Calcium, chlorine, manganese and cobalt were found to be enriched in the phloem and also concentrated in the epidermis and cortex of the studied species. Although hyperaccumulation ostensibly evolved numerous times independently, the basic mechanisms inferred from tissue elemental localization are convergent in these tropical woody species from Borneo Island.
    Matched MeSH terms: Minerals
  2. Bhat R, binti Yahya N
    Food Chem, 2014 Aug 1;156:42-9.
    PMID: 24629936 DOI: 10.1016/j.foodchem.2014.01.063
    Belinjau (Gnetum gnemon L.) seed flour was evaluated for nutritional composition, antioxidant activity and functional properties. Seed flour was found to be rich in protein (19.0g/100g), crude fibre (8.66g/100g), carbohydrates (64.1%), total dietary fibre (14.5%) and encompassed adequate amounts of essential amino acids, fatty acids and minerals. Antioxidant compounds such as total phenols (15.1 and 12.6mgGAE/100g), tannins (35.6 and 16.1mgCE/100g) and flavonoids (709 and 81.6mgCEQ/100g) were higher in ethanolic extracts over aqueous extracts, respectively. Inhibition of DPPH was high in ethanol extracts (48.9%) compared to aqueous extracts (19.7%), whereas aqueous extracts showed a higher FRAP value compared to ethanol extracts (0.98 and 0.61mmolFe(II)/100g, respectively). Results on functional properties revealed acceptable water and oil absorption capacities (5.51 and 1.98g/g, respectively), emulsion capacity and stability (15.3% and 6.90%, respectively), and foaming capacity (5.78%). FTIR spectral analysis showed seed flour to encompass major functional groups such as: amines, amides, amino acids, polysaccharides, carboxylic acids, esters and lipids. As belinjau seed flour possesses a rich nutraceutical value, it has high potential to be used as a basic raw material to develop new low cost nutritious functional foods.
    Matched MeSH terms: Minerals/analysis
  3. Jaswir I, Shahidan N, Othman R, Has-Yun Hashim YZ, Octavianti F, bin Salleh MN
    J Oleo Sci, 2014;63(8):761-7.
    PMID: 25007748
    Carotenoids are antioxidants with pharmaceutical potential. The major carotenoids important to humans are α-carotene, β-carotene, lycopene, lutein, zeaxanthin, and β-cryptoxanthin. Some of the biological functions and actions of these individual carotenoids are quite similar to each other, whereas others are specific. Besides genotype and location, other environmental effects such as temperature, light, mineral uptake, and pH have been found affect carotenoid development in plant tissues and organs. Therefore, this research investigated the effects of the season and storage periods during postharvest handling on the accumulation of carotenoid in pumpkin. This study shows that long-term storage of pumpkins resulted in the accumulation of lutein and β-carotene with a slight decrease in zeaxanthin. The amounts of β-carotene ranged from 174.583±2.105 mg/100g to 692.871±22.019 mg/100g, lutein from 19.841±9.693 mg/100g to 59.481±1.645 mg/100g, and zeaxanthin from not detected to 2.709±0.118 mg/100g. The pumpkins were collected three times in a year; they differed in that zeaxanthin was present only in the first season, while the amounts of β-carotene and lutein were the highest in the second and third seasons, respectively. By identifying the key factors among the postharvest handling conditions that control specific carotenoid accumulations, a greater understanding of how to enhance the nutritional values of pumpkin and other crops will be gained. Postharvest storage conditions can markedly enhance and influence the levels of zeaxanthin, lutein, and β-carotene in pumpkin. This study describes how the magnitudes of these effects depend on the storage period and season.
    Matched MeSH terms: Minerals/metabolism
  4. Rohana Abdul Jalil, Zulkifli Ahmad
    MyJurnal
    The aim of the study is to describe the usage of dietary supplemenu among doctors working in the hospitals in Kota Bharu, Kelantan. The method used was a postal questionaire survey of the doctors, both specialists and medical officers working in these hospitals. The results showed that
    only 28.7% of the doctors are taking dietary supplements. Significantly more female doctors and doctors on long term medication, were taking these supplements. The dietary supplements commonly used were multivitamins and minerals (92.3%), garlic (26.9%), vitamin C (26.9%) and
    lecithin (15.4%). The majority of the doctors who took dietary supplements (60%) felt their health status have improved. These supplements were mostly obtained from hospital pharmacies. Doctors who puchase their own supplements spend between RMIO to RMIZO per month. The main reasons given for taking these supplements were that the doctors jfelt healthier' and to ‘prevent or as a supplementary treatment’ for conditions like hypercholesterolaemia, hypertension, ischaemic heart disease and cancers. There were four doctors who regularly use traditional dietary supplements. Most doctors will generally advice their patients and children to take dietary supplements regularly, as they felt that it is important for health.
    Matched MeSH terms: Minerals
  5. Nazrun, A.S., Aqilah-Sn, S.M.Z, Sabarul, A.M., Isa, N.M., Zulfarina, S.M.
    Medicine & Health, 2014;9(1):1-10.
    MyJurnal
    Osteoporosis dikenali sebagai penyakit senyap kerana tidak mempunyai tanda-tanda awal. Ini disebabkan oleh kepadatan tulang yang berkurangan secara perlahanlahan seiring dengan peningkatan usia. Insiden penyakit ini semakin meningkat setiap tahun di seluruh dunia. Mengukur ketumpatan mineral tulang (BMD) menggunakan densitometry tulang konvensional (DXA) adalah praktikal dalam diagnosis osteoporosis tetapi kosnya adalah tinggi dan tidak dapat dilaksanakan dalam masyarakat. Untuk mengukur ketumpatan tulang, “quantitative ultrasound” (QUS) adalah teknik yang agak moden untuk diagnosis osteoporosis. Ianya agak mudah, konsisten, lebih murah dan kaedah yang selamat berbanding dengan teknik densitometry yang lain. Kedua-dua parameter QUS yang diukur pada masa kini adalah ultrasound jalur pengecilan (BUA) dan kelajuan bunyi (SOS). QUS juga dapat menjangka risiko patah. Ianya kini digunakan untuk memantau tindakbalas kepada rawatan anti-osteoporosis. Kajian in-vitro menunjukkan bahawa indeks QUS berhubungkait dengan BMD, bentuk tulang mikro dan parameter mekanikal. Oleh yang demikian, QUS berupaya untuk menjadi teknik baru untuk penilaian tulang.
    Matched MeSH terms: Minerals
  6. Nur Hasyimah Ramli, Zuhrah Aini Sulaiman
    MyJurnal
    Fertilizers are the most important and complex nutrients for crop plants in particular for grain yield and quality. The composition of the fertilizer as well as the essential elements that influence the growth of the crop need to be clearly identified. Due to that, this study was carried out to investigate the effect of different fertilizer formulation on the leaf mustard (Brassica juncea) growth. High nitrogen, phosphorus and potassium fertilizers were used to investigate their effects on the morphometric size of the leaves, plant height and the leaf area index of the leaf mustard. Results showed that the application of different formulation of fertilizer improves the growth of leaf mustard compared to control. Leaf mustard with the high phosphorus treatment recorded an increase in plant height and the leaf area index (LAI). Lamina length (LL) range is shown between phosphorus and control (1.11 cm), while the range of lamina width (LW), left width (WL) and right width (WR) are between potassium and control about
    0.57 cm, 0.28 cm and 0.28 cm, respectively. Overall, there is a significant difference between the leaf mustard leaves in different high element fertilizers compared with all of the variable, F(15,1024) = 29.26, p0.05, no significant difference). The highest mean in LAI was obtained when treated with a high phosphorus fertilizer (0.47 m2). The mean difference of LAI of high phosphorus compared to high potassium, high nitrogen and control is 0.02 m2, 0.08 m2 and 0.12 m2. There is no significant differences between the LAI in different high element fertilizers with F(3,176) = 0.15; p>0.05. Further study should be conducted to determine the effects of different fertilizers on the growth of other vegetables and fruit quality.
    Matched MeSH terms: Minerals
  7. Nashriyah Mat, Mazleha Maskin, Abdul Khalik Wood, Zaini Hamzah
    MyJurnal
    Mineral elemental uptake by Colocasia esculenta growing in swamp agroecosystem was studied following 14, 18 or 28 months of field spraying (MAT, months after treatment) with herbicide Gramoxone ® (paraquat). In overall, Al (68226.67 + 24066.56 μg/g dw) was the major element in riverine alluvial swamp soil, followed by micronutrient Fe (22280.00 + 6328.87 μg/g dw).
    Concentration of macronutrient K (20733.33 + 7371.82 μg/g dw) was the highest in swamp taro leaf followed by macronutrient Ca (7050.00 + 3767.26 μg/g dw). In overall, the order of importance of the average mineral concentration in swamp taro leaf was K > Ca > Mn > Al > Na > Fe > Zn > Br > Co. However at 14 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Al > Na > Mn > Fe > Zn > Br > Co. At 18 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Al > Fe > Na > Zn > Br > Co. At 28 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Fe > Al > Zn > Na > Br > Co. In overall, the average order of importance of mineral elemental uptake or the soil plant transfer coefficient was Mn > K > Na > Zn > Co > Fe > Al; similar with the order at 28 MAT. However, at 14 MAT the order of importance of the soil plant transfer coefficient was different at Mn > K > Na > Co > Zn > Al > Fe.
    Matched MeSH terms: Minerals
  8. Ahmad Saat, Zaini Hamzah
    MyJurnal
    Clay has been regarded as very important natural industrial materials. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. A study was carried out on clay samples from eight sites in the north-eastern part of Peninsular Malaysia. The study was accomplished by using X-ray diffraction (XRD) technique. The x-ray diffraction spectra obtained enable the determination of the lattice spacing associated with the types of clay and nonclay minerals present in the samples. Results of the study shows that the major components of clay minerals present in all samples studied are kaolinite and illite. The presence of kaolinite is confirmed by firing test in which the kaolinite diffraction peaks disappeared upon heating the samples at 600 o C. The presence of non-clay minerals such as quartz, mica, feldspar and chlorite are also observed.
    Matched MeSH terms: Minerals
  9. Ahmad Saat, Zaini Hamzah, Zaharidah Abu Bakar
    MyJurnal
    Being an imperative material for man either used as building materials, pottery or as components in material industry and technology, knowledge of clays elemental contents is important. In the present study ten clay samples obtained from various locations in North-West Peninsular Malaysia were used. Majority of the clays were economically manufactured to be used as building materials or pottery. The objective of study was to determine the main elemental contents of the samples, and relate the results to the types of minerals, as well as to compare them with clays from other studies. In the study X-ray Fluorescence (XRF) coupled to samples dilution method and standard calibration samples was used. The elements detected in the study were Si, Al, Fe, Ti, K and Ca. Depending on locations, the percentage concentration ranged between 24.8 – 32.4 for Si, 10.8 – 19.0 for Al, 0.09 – 2.12 for Fe, 0.08 – 1.13 for Ti, 0.45 – 3.39 for K and trace amount of Ca and P. However, Mg that normally found in typical clay was not found in the studied samples. Comparing the oxide of the major elements with other studies, it was found that the clay samples contained mixtures of kaolinite (two-layered structure) and illite (three-layered structure).
    Matched MeSH terms: Minerals
  10. Ahmad M, Masood S, Sultana S, Hadda TB, Bader A, Zafar M
    Pak J Pharm Sci, 2015 Jan;28(1):241-7.
    PMID: 25553701
    Nutritional quality and antioxidant capacity of three edible wild berries (Rubus ellipticus Smith, Rubus niveus Thunb, Rubus ulmifolius L.) from Lesser Himalayan Range (LHR) were evaluated. Their edible portion was assayed for moisture, fats, ash, carbohydrates, proteins, fibers, essential minerals (Ca, P, Mg, K, Na, Cl, S, Mn, Zn, Fe, Cu, Se, Co, Ni) and DPPH free radical scavenging activity was applied to determine the antioxidant potential. The fruit of Rubus ulmifolius L. (blackberry) possessed the highest values of energy (403.29 Kcal), total protein (6.56g/100 g), Nitrogen (N) content (1500mg/100g), K (860.17mg/100g), Ca (620.56mg/100g), Zn (17.509mg/100g) and the strongest antioxidant activity (98.89% inhibition). While the raspberries (Rubus ellipticus Smith, Rubus niveus Thunb.) exhibited more significant contents of dietary fiber (5.90g/100g), carbohydrates (86.4 g/100 g) and Fe (4.249mg/100g). Significant variation was observed among the tested samples in all the investigated features. The combination of bio elements and active antioxidants clearly showed the applicability of these berries as a nutraceutical supplement.
    Matched MeSH terms: Minerals/analysis
  11. Fanhui-Zeng, Jianchun-Guo, Yuxuan-Liu
    Sains Malaysiana, 2015;44:1377-1388.
    Hydraulic fracturing becomes more difficult when confronted with a formation of high fracturing pressure. In such formations, acidizing before the main fracturing treatment provide a method to reduce fracture pressure. The aim of this paper was to investigate the evolution of fracture pressure in a wellbore with acidizing. Five experiments were conducted to study the mechanisms of acid damage on reservoir minerals and cementing materials properties. Consequently, a mathematical model to predict fracture pressure with acidizing has been established and verified by field data. The analysis results showed that it is possible to reduce fracture pressure with decreased rock strength and fracture critical stress intensity factor by means of acid damage. Acid damage destroys the crystal structure of mineral particles, breaks the crystalline layers in cementing materials, increases rock porosity and reduces the rock strength. In addition, as the acid concentration, formation temperature and acid treatment time increased, it was useful to reduce fracture pressure in the wellbore. Using the proposed model, we were able to select the optimal acid damage construction parameters to reduce fracture pressure.
    Matched MeSH terms: Minerals
  12. Judge C, O'Donnell MJ, Hankey GJ, Rangarajan S, Chin SL, Rao-Melacini P, et al.
    Am J Hypertens, 2021 04 20;34(4):414-425.
    PMID: 33197265 DOI: 10.1093/ajh/hpaa176
    BACKGROUND: Although low sodium intake (<2 g/day) and high potassium intake (>3.5 g/day) are proposed as public health interventions to reduce stroke risk, there is uncertainty about the benefit and feasibility of this combined recommendation on prevention of stroke.

    METHODS: We obtained random urine samples from 9,275 cases of acute first stroke and 9,726 matched controls from 27 countries and estimated the 24-hour sodium and potassium excretion, a surrogate for intake, using the Tanaka formula. Using multivariable conditional logistic regression, we determined the associations of estimated 24-hour urinary sodium and potassium excretion with stroke and its subtypes.

    RESULTS: Compared with an estimated urinary sodium excretion of 2.8-3.5 g/day (reference), higher (>4.26 g/day) (odds ratio [OR] 1.81; 95% confidence interval [CI], 1.65-2.00) and lower (<2.8 g/day) sodium excretion (OR 1.39; 95% CI, 1.26-1.53) were significantly associated with increased risk of stroke. The stroke risk associated with the highest quartile of sodium intake (sodium excretion >4.26 g/day) was significantly greater (P < 0.001) for intracerebral hemorrhage (ICH) (OR 2.38; 95% CI, 1.93-2.92) than for ischemic stroke (OR 1.67; 95% CI, 1.50-1.87). Urinary potassium was inversely and linearly associated with risk of stroke, and stronger for ischemic stroke than ICH (P = 0.026). In an analysis of combined sodium and potassium excretion, the combination of high potassium intake (>1.58 g/day) and moderate sodium intake (2.8-3.5 g/day) was associated with the lowest risk of stroke.

    CONCLUSIONS: The association of sodium intake and stroke is J-shaped, with high sodium intake a stronger risk factor for ICH than ischemic stroke. Our data suggest that moderate sodium intake-rather than low sodium intake-combined with high potassium intake may be associated with the lowest risk of stroke and expected to be a more feasible combined dietary target.

    Matched MeSH terms: Minerals
  13. Mou Y, Yingfeng-Meng, Gao L, Lin H, Yufei-Li
    Sains Malaysiana, 2014;43:81-87.
    It is well-known that the characteristics of hardness and drillability are influenced by microstructure of rock. In this study, rock properties were analyzed on grain size and grain content. Coarse-grain and fine-grain sandstones were tested under successive indentation condition. Eighteen groups of sandstone and shale were employed for the drillability test. Indentation tests results showed that grain size influenced the low point of residual hardness, the crushing depth and volume and grain content influenced the peak point of hardness. The drillability values of shale increased with increasing contents of clay and quartz. Meanwhile, drillability values of sandstone increased with increasing content of quartz, but decreased with increasing content of clay. Therefore, these preliminary studies show great potential applications for selecting suitable bit type and formulating drilling program as a function of rock microstructure and crushing rock method for bit in the oil drilling.
    Matched MeSH terms: Minerals
  14. Lee HH, Loh SP, Bong CF, Sarbini SR, Yiu PH
    J Food Sci Technol, 2015 Dec;52(12):7806-16.
    PMID: 26604353 DOI: 10.1007/s13197-015-1918-9
    Whole grains consumption promotes health benefits, but demonstrates controversial impacts from phytic acid in meeting requirements of good health. Therefore, this study was aimed to determine the nutrient bioaccessibility and antioxidant properties of rice cultivars named "Adan" or "Bario" and deduce the nutritional impact of phytic acid. Majority of the dehusked rice in the collection showed an acceptable level of in-vitro starch digestibility and in-vitro protein digestibility, but were poor in antioxidant properties and bioaccessibility of minerals (Ca, Fe and Zn). The drawbacks identified in the rice cultivars were due to relatively high phytic acid content (2420.6 ± 94.6 mg/100 g) and low phenolic content (152.39 ± 18.84 μg GAE/g). The relationship between phytic acid content and mineral bioaccessibility was strongest in calcium (r = 0.60), followed by iron (r = 0.40) and zinc (r = 0.27). Phytic acid content did not significantly correlate with in-vitro starch digestibility and in-vitro protein digestibility but showed a weak relationship with antioxidant properties. These suggest that phytic acid could significantly impair the mineral bioaccessibility of dehusked rice, and also act as an important antioxidant in non-pigmented rice. Bario rice cultivars offered dehusked rice with wide range of in-vitro digestibility of starch and protein, and also pigmented rice as a good source of antioxidants. However, there is a need to reduce phytic acid content in dehusked rice for improved mineral bioaccessibility among Bario rice cultivars.
    Matched MeSH terms: Minerals
  15. Omale SO, Choong TSY, Abdullah LC, Siajam SI, Yip MW
    Heliyon, 2019 Oct;5(10):e02602.
    PMID: 31667417 DOI: 10.1016/j.heliyon.2019.e02602
    Iron and steel industries are among the contributors of CO2 emission in large volume into the atmosphere, causing detrimental effects to the environment and the ecosystem at large scale. These industries also generate solid wastes in the form of electric arc furnace (EAF) slag during operations which result in about 10-15% slag wastes per ton of steel produced. In this study, the EAF slags from an iron and steel-making factory in Klang, Malaysia was utilized for CO2 sequestration through direct aqueous mineral carbonation. According to the surface area analysis, the fresh EAF slag has a mesoporous structure, its elemental composition shows the presence of 20.91 wt.% of CaO that was used for the sequestration of CO2 through carbonation. The sequestration capacity was found to be 58.36 g CO2/kg of slag at ambient temperature in 3 h, with the liquid/solid (L/S) ratio of 5:1 and using <63μm particle size. Moreover, the shrinking core model (SCM) was used to analyze the solid-fluid reaction in a heterogeneous phase and the CO2 sequestration shows to be controlled by the product layer phase. The EAF slag is demonstrated to have the potential of CO2 sequestration at ambient temperature.
    Matched MeSH terms: Minerals
  16. Levin LA, Wei CL, Dunn DC, Amon DJ, Ashford OS, Cheung WWL, et al.
    Glob Chang Biol, 2020 09;26(9):4664-4678.
    PMID: 32531093 DOI: 10.1111/gcb.15223
    Climate change manifestation in the ocean, through warming, oxygen loss, increasing acidification, and changing particulate organic carbon flux (one metric of altered food supply), is projected to affect most deep-ocean ecosystems concomitantly with increasing direct human disturbance. Climate drivers will alter deep-sea biodiversity and associated ecosystem services, and may interact with disturbance from resource extraction activities or even climate geoengineering. We suggest that to ensure the effective management of increasing use of the deep ocean (e.g., for bottom fishing, oil and gas extraction, and deep-seabed mining), environmental management and developing regulations must consider climate change. Strategic planning, impact assessment and monitoring, spatial management, application of the precautionary approach, and full-cost accounting of extraction activities should embrace climate consciousness. Coupled climate and biological modeling approaches applied in the water and on the seafloor can help accomplish this goal. For example, Earth-System Model projections of climate-change parameters at the seafloor reveal heterogeneity in projected climate hazard and time of emergence (beyond natural variability) in regions targeted for deep-seabed mining. Models that combine climate-induced changes in ocean circulation with particle tracking predict altered transport of early life stages (larvae) under climate change. Habitat suitability models can help assess the consequences of altered larval dispersal, predict climate refugia, and identify vulnerable regions for multiple species under climate change. Engaging the deep observing community can support the necessary data provisioning to mainstream climate into the development of environmental management plans. To illustrate this approach, we focus on deep-seabed mining and the International Seabed Authority, whose mandates include regulation of all mineral-related activities in international waters and protecting the marine environment from the harmful effects of mining. However, achieving deep-ocean sustainability under the UN Sustainable Development Goals will require integration of climate consideration across all policy sectors.
    Matched MeSH terms: Minerals
  17. Saba, Z.H., Suzana, M., Yasmin Anum, M.Y.
    Medicine & Health, 2013;8(1):3-18.
    MyJurnal
    Madu adalah bahan semulajadi yang dihasilkan oleh lebah madu, Apis mellifera, berpunca daripada madu yang diambil dari bunga yang berkembang atau cecair dari pokok dan tumbuhan yang dikenali sebagai madu nektar dan madu serangga masing-masing. Ia adalah larutan tepu gula, yang kaya dengan protein, mineral, vitamin, asid organik dan polifenol. Madu mempunyai pelbagai khasiat, sifat penyembuhan dan profilaktik disebabkan oleh komponen-komponen yang terkandung di dalamnya. Madu mempunyai beberapa khasiat kesihatan seperti penyembuhan luka, antimikrob, antioksidan dan potensi anti-radang. Ulasan ini adalah berkaitan komposisi nutrien, antioksidan dan kesan terapeutik madu dengan penekanan kepada madu di Malaysia.
    Matched MeSH terms: Minerals
  18. SH, Ku, YS, Tan, Yahya NA
    Ann Dent, 2014;21(1):25-32.
    MyJurnal
    The study aimed to evaluate the quality of the hybrid
    layer form by three different adhesive systems. Class V
    cavities were prepared on the buccal surface of fourty
    extracted human premolars. The prepared teeth were
    randomly assigned into four groups according to the
    adhesive system and application mode. The systems
    were: Optibond S (OS, total-etch); Optibond Versa (OV,
    two-bottles, self-etch); Single Bond Universal (SBU,
    one-bottle, self-etch) and Single Bond Universal with
    etchant (SBU + etchant). All cavities were restored with
    composite (Filtek Z350XT). The samples were sectioned,
    polished and pretreated to remove minerals, protein
    and water prior to SEM evaluation. From the images,
    thickness of the hybrid layers was measured. Present of
    resin tags and adaptation failure were also recorded. The
    data obtained were analyzed using ANOVA, Dunnett’s
    T3, Kruskal-Wallis and Mann-Whitney tests. OS group
    showed the highest average hybrid layer thickness (4.34
    µm), followed by SBU + etchant (3.06 µm), OV (1.91 µm)
    and SBU (0.95 µm). Both adhesive and cohesive failures
    were observed in SBU group. Present of prominent resin
    tags were seen in both OS and OV groups. In conclusion,
    all the investigated adhesive systems were able to perform
    distinguishable actions as shown in micro-morphological
    alteration and hybrid layer thickness. Two-bottles, selfetch
    adhesive (OV) was proven to produce negligible
    adaptation failure compared to other adhesive systems in
    the present study. Combined all-in-one adhesive (SBU)
    was found to render a superior bonding performance in
    total-etch mode comparing to self-etch mode.
    Matched MeSH terms: Minerals
  19. Ismail M, Manickam E, Danial AM, Rahmat A, Yahaya A
    J Nutr Biochem, 2000 Nov;11(11-12):536-542.
    PMID: 11137889
    This study investigated the components present in and the total antioxidant activity of leaves of Strobilanthes crispus (L.) Bremek or Saricocalyx crispus (L.) Bremek (Acanthacea). Proximate analyses and total antioxidant activity using ferric thiocyanate and thiobarbituric acid methods were employed. Minerals content was determined using the atomic absorption spectrophotometer, whereas the water-soluble vitamins were determined by means of the UV-VIS spectrophotometer (vitamin C) and fluorimeter (vitamins B(1) and B(2)). Catechin, tannin, caffeine, and alkaloid contents were also studied. All data were compared to the previously reported results of Yerbamate, green tea, black tea, and Indian tea. The dried leaves contained a high amount of total ash (21.6%) as a result of a high amount of minerals including potassium (51%), calcium (24%), sodium (13%), iron (1%), and phosphorus (1%). High content of water-soluble vitamins (C, B(1), and B(2)) contributed to the high antioxidant activity of the leaves. The leaves also contained a moderate amount of other proximate composition as well as other compounds such as catechins, alkaloids, caffeine, and tannin, contributing further to the total antioxidant activity. Catechins of Strobilanthes crispus leaves showed highest antioxidant activity when compared to Yerbamate and vitamin E. Consumption of the leafy extract daily (5 g/day) as an herbal tea could contribute to the additional nutrients and antioxidants needed in the body to enhance the defense system, especially toward the incidence of degenerative diseases.
    Matched MeSH terms: Minerals
  20. Raof NA, Yunus R, Rashid U, Azis N, Yaakub Z
    Protein Pept Lett, 2018;25(2):171-179.
    PMID: 29359647 DOI: 10.2174/0929866525666180122095056
    BACKGROUND: The transesterification of high oleic palm oil methyl ester (HOPME) with neopentyl glycol (NPG) has been investigated. The present study revealed the application of low-pressure technology as a new synthesis method to produce NPG diesters. Single variable optimization and response surface methodology (RSM) were implemented to optimize the experimental conditions to achieve the maximum composition (wt%) of NPG diesters.

    OBJECTIVE: The main objective of this study was to optimize the production of NPG diesters and to characterize the optimized esters with typical chemical, physical and electrical properties to study its potential as insulating oil.

    METHODS: The transesterification reaction between HOPME and NPG was conducted in a 1L three-neck flask reactor at specified temperature, pressure, molar ratio and catalyst concentration. For the optimization, four factors have been studied and the diester product was characterized by using gas chromatography (GC) analysis. The synthesized esters were then characterized with typical properties of transformer oil such as flash point, pour point, viscosity and breakdown voltage and were compared with mineral insulating oil and commercial NPG dioleate. For formulation, different samples of NPG diesters with different concentration of pour point depressant were prepared and each sample was tested for its pour point measurement.

    RESULTS: The optimum conditions inferred from the analyses were: molar ratio of HOPME to NPG of 2:1.3, temperature = 182°C, pressure = 0.6 mbar and catalyst concentration of 1.2%. The synthesized NPG diesters showed very important improvement in fire safety compared to mineral oil with flash point of 300°C and 155°C, respectively. NPG diesters also exhibit a relatively good viscosity of 21 cSt. The most striking observation to emerge from the data comparison with NPG diester was the breakdown voltage, which was higher than mineral oil and definitely in conformance to the IEC 61099 limit at 67.5 kV. The formulation of synthesized NPD diesters with VISCOPLEX® pour point depressant has successfully increased the pour point of NPG diester from -14°C to -48°C.

    CONCLUSION: The reaction time for the transesterification of HOPME with NPG to produce NPG diester was successfully reduced to 1 hour from the 14 hours required in the earlier synthesis method. The main highlight of this study was the excess reactant which is no longer methyl ester but the alcohol (NPG). The optimum reaction conditions for the synthesis were molar ratio of 2:1.13 for NPG:HOPME, 182°C, 0.6 mbar and catalyst concentration of 1.2 wt%. The maximum NPG diester yield of 87 wt% was consistent with the predicted yield of 87.7 wt% obtained from RSM. The synthesized diester exhibited better insulating properties than the commercial products especially with regards to the breakdown voltage, flash point and moisture content.

    Matched MeSH terms: Minerals
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