Displaying publications 41 - 60 of 190 in total

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  1. Cortisol emphasizes the metabolic strategies employed by common carp, Cyprinus carpio at different feeding and swimming regimes
    Liew HJ, Chiarella D, Pelle A, Faggio C, Blust R, De Boeck G
    Comp Biochem Physiol A Mol Integr Physiol, 2013 Nov;166(3):449-64.
    PMID: 23921225 DOI: 10.1016/j.cbpa.2013.07.029
    The objective of this study was to investigate the interaction between feeding, exercise and cortisol on metabolic strategies of common carp over a 168h post-implant period. Feeding provided readily available energy and clearly increased muscle and liver protein and glycogen stores. Swimming, feeding and cortisol all induced aerobic metabolism by increasing oxygen consumption, and stimulated protein metabolism as demonstrated by the increased ammonia and urea excretion and ammonia quotient. Hypercortisol stimulated ammonia self-detoxifying mechanisms by enhancing ammonia and urea excretion, especially during severe exercise. At high swimming level, higher branchial clearance rates in cortisol treated fish succeeded in eliminating the elevation of endogenous ammonia, resulting in reduced plasma Tamm levels compared to control and sham implanted fish. Carp easily induced anaerobic metabolism, both during routine and active swimming, with elevated lactate levels as a consequence. Both feeding and cortisol treatment increased this dependence on anaerobic metabolism. Hypercortisol induced both glycogenesis and gluconeogenesis resulting in hyperglycemia and muscle and liver glycogen deposition, most likely as a protective mechanism for prolonged stress situations and primarily fuelled by protein mobilization.
    Matched MeSH terms: Urea/blood; Urea/urine
  2. Graphene oxide as a structure-directing agent for the two-dimensional interface engineering of sandwich-like graphene-g-C3N4 hybrid nanostructures with enhanced visible-light photoreduction of CO2 to methane
    Ong WJ, Tan LL, Chai SP, Yong ST
    Chem Commun (Camb), 2015 Jan 18;51(5):858-61.
    PMID: 25429376 DOI: 10.1039/c4cc08996k
    A facile one-pot impregnation-thermal reduction strategy was employed to fabricate sandwich-like graphene-g-C3N4 (GCN) nanocomposites using urea and graphene oxide as precursors. The GCN sample exhibited a slight red shift of the absorption band edge attributed to the formation of a C-O-C bond as a covalent cross linker between graphene and g-C3N4. The GCN sample demonstrated high visible-light photoactivity towards CO2 reduction under ambient conditions, exhibiting a 2.3-fold enhancement over pure g-C3N4. This was ascribed to the inhibition of electron-hole pair recombination by graphene, which increased the charge transfer.
    Matched MeSH terms: Urea
  3. N-doped TiO2 synthesised via microwave induced photocatalytic on RR4 dye removal under LED light irradiation
    Azami MS, Nawawi WI, Ali H. Jawad, Ishak MAM, Azami MS, K. Ismail
    Sains Malaysiana, 2017;46:1390-1316.
    Nitrogen doped titanium dioxide (N-doped TiO2
    ) was synthesized by microwave using urea as nitrogen sources with
    commercially available TiO2
    -P25. The N-doped TiO2
    was compared with unmodified TiO2
    by carrying out the investigation
    on its properties using x-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET), Fourier transformed infrared
    spectroscopy (FTIR) and diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activities of N-doped TiO2
    and unmodified TiO2 were studied for photodegradation of reactive red 4 (RR4) under light emitting diode (LED) light
    irradiation. An active photoresponse under LED light irradiation was observed from N-doped TiO2
    with 60 min of time
    irradiation to complete RR4 color removal while no photocatalytic degradation was observed from unmodified.
    Matched MeSH terms: Urea
  4. Fulltext Effect of Biodegradable Binder Properties and Operating Conditions on Growth of Urea Particles in a Fluidized Bed Granulator
    Zhalehrajabi E, Lau KK, Ku Shaari KZ, Zahraee SM, Seyedin SH, Azeem B, et al.
    Materials (Basel), 2019 Jul 20;12(14).
    PMID: 31330846 DOI: 10.3390/ma12142320
    Granulation is an important step during the production of urea granules. Most of the commercial binders used for granulation are toxic and non-biodegradable. In this study, a fully biodegradable and cost-effective starch-based binder is used for urea granulation in a fluidized bed granulator. The effect of binder properties such as viscosity, surface tension, contact angle, penetration time, and liquid bridge bonding force on granulation performance is studied. In addition, the effect of fluidized bed process parameters such as fluidizing air inlet velocity, air temperature, weight of primary urea particles, binder spray rate, and binder concentration is also evaluated using response surface methodology. Based on the results, binder with higher concentration demonstrates higher viscosity and higher penetration time that potentially enhance the granulation performance. The viscous Stokes number for binder with higher concentration is lower than critical Stokes number that increases coalescence rate. Higher viscosity and lower restitution coefficient of urea particles result in elastic losses and subsequent successful coalescence. Statistical analysis indicate that air velocity, air temperature, and weight of primary urea particles have major effects on granulation performance. Higher air velocity increases probability of collision, whereby lower temperature prevents binder to be dried up prior to collision. Findings of this study can be useful for process scale-up and industrial application.
    Matched MeSH terms: Urea
  5. A urea precursor to synthesize carbon nitride with mesoporosity for enhanced activity in the photocatalytic removal of phenol
    Lee SC, Lintang HO, Yuliati L
    Chem Asian J, 2012 Sep;7(9):2139-44.
    PMID: 22733646 DOI: 10.1002/asia.201200383
    A urea precursor was used for the first time to prepare mesoporous carbon nitride (MCN) by a thermal polymerization process with silica nanospheres as a hard template. Although the prepared MCN samples have similar structures and optical properties, it was revealed that the specific surface area, pore-size distribution, and morphology of the MCN samples depend on the initial mass ratio of urea to silica. Compared to the bulk carbon nitride (BCN) that only gave 20% phenol removal (6 h of irradiation), the activities can be enhanced up to 74% on MCN samples for photocatalytic removal of phenol under visible-light irradiation. The highest conversion was obtained on MCN with an initial mass ratio of urea to silica of 5, which has high surface area of 191 m(2) g(-1) and a nanoporous structure with uniform pore-size distribution of 7 nm. In addition to the high activity, the MCN sample also showed high photocatalytic stability.
    Matched MeSH terms: Urea
  6. Fulltext Crystal structure of 2'-hy-droxy-aceto-phenone 4-methyl-thio-semicarbazide
    Jamsari J, Abas NF, Ravoof TB, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Apr 1;71(Pt 4):o244-5.
    PMID: 26029436 DOI: 10.1107/S2056989015004958
    In the organic mol-ecule of the title hydrate, C11H15N3OS·H2O, {systematic name: 3-ethyl-1-{(E)-[1-(2-hy-droxy-phen-yl)ethyl-idene]amino}-thio-urea monohydrate}, a dihedral angle of 5.39 (2)° is formed between the hy-droxy-benzene ring and the non-H atoms comprising the side chain (r.m.s. deviation = 0.0625 Å), with the major deviation from planarity noted for the terminal ethyl group [the C-N-C-C torsion angle = -172.17 (13)°]. The N-H H atoms are syn and an intra-molecular hy-droxy-imine O-H⋯N hydrogen bond is noted. In the crystal, the N-bonded H atoms form hydrogen bonds to symmetry-related water mol-ecules, and the latter form donor inter-actions with the hy-droxy O atom and with a hy-droxy-benzene ring, forming a O-H⋯π inter-action. The hydrogen bonding leads to supra-molecular tubes aligned along the b axis. The tubes are connected into layers via C-H⋯O inter-actions, and these stack along the c axis with no directional inter-actions between them.
    Matched MeSH terms: Urea
  7. Co-Electrolysis-Assisted Decomposition of Hydroxylammonium Nitrate-Fuel Mixtures Using Stainless Steel-Platinum Electrodes
    Chai WS, Sun D, Cheah KH, Li G, Meng H
    ACS Omega, 2020 Aug 11;5(31):19525-19532.
    PMID: 32803046 DOI: 10.1021/acsomega.0c01804
    Hydroxylammonium nitrate (HAN) is a promising green propellant because of its low toxicity, high volumetric specific impulse, and reduced development cost. Electrolytic decomposition of HAN is an efficient approach to prepare it for further ignition and combustion. This paper describes the investigation of a co-electrolysis effect on electrolytic decomposition of HAN-fuel mixtures using stainless steel-platinum (SS-Pt) electrodes. For the first time, different materials were utilized as electrodes to alter the cathodic reaction, which eliminated the inhibition effect and achieved a repeatable and consistent electrolytic decomposition of HAN solution. Urea and methanol were added as fuel components in the HAN-fuel mixtures. When the mass ratio of added urea ≥20%, the electrolytic decomposition of a HAN-urea ternary mixture achieved 67% increment in maximum gas temperature (Tgmax) and 185% increment in overall temperature increasing rate over the benchmark case of HAN solution. The co-electrolysis of urea released additional electrons into the mixtures and enhanced the overall electrolytic decomposition of HAN. In contrast, the addition of methanol did not improve the Tgmax but only increased the overall temperature increasing rate. This work has important implications in the development of an efficient and reliable electrolytic decomposition system of HAN and its mixtures for propulsion applications.
    Matched MeSH terms: Urea
  8. Fulltext Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation
    Choo MY, Oi LE, Daou TJ, Ling TC, Lin YC, Centi G, et al.
    Materials (Basel), 2020 Jul 11;13(14).
    PMID: 32664579 DOI: 10.3390/ma13143104
    Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition-precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h-1) was 1.5 times higher than that of the IM method (9.6 goil·h-1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Brönsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition.
    Matched MeSH terms: Urea
  9. Fulltext Release Mechanisms and Kinetic Models of Gypsum-Sulfur-Zeolite-Coated Urea Sealed with Microcrystalline Wax for Regulated Dissolution
    Eghbali Babadi F, Yunus R, Masoudi Soltani S, Shotipruk A
    ACS Omega, 2021 May 04;6(17):11144-11154.
    PMID: 34056270 DOI: 10.1021/acsomega.0c04353
    In this study, a mineral-based coated urea was fabricated in a rotary pan coater using a mixture of gypsum/sulfur/zeolite (G25S25Z50) as an effective and low-cost coating material. The effects of different coating compositions on the dissolution rate of urea and the crushing strength and morphology of the coated urea were investigated. A 25:25:50 (wt %) mixture of gypsum/sulfur/zeolite (G25S25Z50) increased the coating effectiveness to 34.1% with the highest crushing strength (31.06 N). The effectiveness of coated urea was further improved to 46.6% with the addition of a microcrystalline wax (3%) as a sealant. Furthermore, the release mechanisms of various urea fertilizers were determined by fitting the release profiles with six mathematical models, namely, the zeroth-order, first-order, second-order, Higuchi, Ritger & Peppas, and Kopcha models. The results showed that the release mechanism of the uncoated urea and all other coated urea followed the Ritger & Peppas model, suggesting the diffusional release from nonswellable delivery systems. In addition, due to the increased mass-transfer resistance, the kinetic constant was decreased from 0.2233 for uncoated urea to 0.1338 for G25S25Z50-coated urea and was further decreased to 0.0985 when 3% Witcovar 146 sealant was applied.
    Matched MeSH terms: Urea
  10. Fulltext Effect of Functionalised and Non-Functionalised Carbon Nanotubes-Urea Fertilizer on the Growth of Paddy
    Yatim NM, Shaaban A, Dimin MF, Yusof F, Razak JA
    Trop Life Sci Res, 2018 Mar;29(1):17-35.
    PMID: 29644013 MyJurnal DOI: 10.21315/tlsr2018.29.1.2
    The roles of multi-walled carbon nanotubes (MWNTs) and functionalised multiwalled carbon nanotubes (fMWNTs) in enhancing the efficacy of urea fertilizer (UF) as plant nutrition for local MR219 paddy variety was investigated. The MWNTs and fMWNTs were grafted onto UF to produce UF-MWNTs fertilizer with three different conditions, coded as FMU1 (0.6 wt. % fMWNTs), FMU2 (0.1 wt. % fMWNTs) and MU (0.6 wt. % MWNTs. The batches of MR219 paddy were systematically grown in accordance to the general practice performed by the Malaysian Agricultural Research and Development Institute (MARDI). The procedure was conducted using a pot under exposure to natural light at three different fertilization times; after a certain number of days of sowing (DAS) at 14, 35 and 55 days. Interestingly, it was found that the crop growth of plants treated with FMU1 and FMU2 significantly increased by 22.6% and 38.5% compared to plants with MU addition. Also, paddy treated with FMU1 produced 21.4% higher number of panicles and 35% more grain yield than MU while paddy treated with FMU2 gave 28.6% more number of panicles and 36% higher grain yield than MU, which implies the advantage of fMWNTs over MWNTs to be combined with UF as plant nutrition. The chemical composition and morphology of UF-MWNTs fertilizers which is further characterised by FTiR and FESEM confirmed the successful and homogeneous grafting of UF onto the fMWNTs.
    Matched MeSH terms: Urea
  11. Fulltext Development of seed treatments biofertilizer and nutrient uptake study using tracer technique for okra plants
    Hoe, Phua Choo Kwai, Khairuddin Abdul Rahim, Ahmad Nazrul Abd Wahid
    Jurnal Sains Nuklear Malaysia, 2013;25(1):16-23.
    MyJurnal
    Development of biofertilizer seed treatments for okra seeds were carried out by mixing phosphate
    solubilising bacteria (AP 3) and plant growth promoter (AP 2) with adhesives. The seeds were
    coated with inoculums and four types of adhesives namely, Gum Arabic; Polyethylene Glycol
    (PEG); Sodium Alginate and Methycellulose respectively. From eight seed treatments, all seed
    treatments significantly increased seed germinations except treatment T4 (Gum Arabic and AP3).
    In general, maximum germination rates and log of viable cells were observed when treated with
    polyethylene glycol 4000 (PEG) mixed with AP2 (T7) and AP3 (T8). These results show that using
    PEG as adhesive enhanced the germination rates and log of viable cells of AP2 and AP3. Thus,
    PEG could be a good adhesive for seed treatment. In greenhouse experiment, okra seeds treatment
    with AP2 and PEG (T1) showed the highest dry weight compared to other treatments. Seeds
    treatment with AP3 and PEG (T2) showed higher contribution of N compare to seeds treatment
    (T1). There were no significant different within seed treatments and urea treatment in okra yield.
    All treatments significantly increased yields compared with control
    Matched MeSH terms: Urea
  12. Fulltext Identification of mutations in Malaysian patients with argininosuccinate lyase (ASL) deficiency
    Ali EZ, Yakob Y, Ngu LH
    Mol Genet Metab Rep, 2019 Dec;21:100525.
    PMID: 31709144 DOI: 10.1016/j.ymgmr.2019.100525
    Argininosuccinate lyase (ASL) deficiency impairs the function of the urea cycle that detoxifies blood ammonia in the body. Mutation that occurs in the ASL gene is the cause of occurrence of ASL deficiency (ASLD). This deficiency causes hyperammonemia, hepatopathy and neurodevelopmental delay in patients. In this study, the clinical characteristics and molecular analysis of 10 ASLD patients were presented. 8 patients were associated with severe neonatal onset, while the other 2 were associated with late onset. Molecular analysis of ASL gene identified four new missense variants, which were c.778C>T, p.(Leu260Arg), c.1340G>C, p.(Ser447Thr), c.436C>G, p.(Arg146Gly) and c.595C>G, p.(Leu199Val) and four reported missense variants, which were c.638G>A, p.(Arg213Gln); c.556C>T, p.(Arg186Trp), c.578G>A, p.(Arg193Gln) and c.436C>G, p.(Arg146Trp). In silico servers predicted all new and reported variants as disease-causing. Structural examination exhibited that all pathogenic variants affected the stability of the tetrameric ASL structure by disturbing the bonding pattern with the neighboring residues.

    Conclusion: This study revealed the genetic heterogeneity among Malaysian ASL patients. This study has also expanded the mutational spectrum of the ASL.

    Matched MeSH terms: Urea
  13. Optimization of microencapsulation process for self-healing polymeric material
    Then S, Gan SN, Noor Hayaty Abu Kasim
    Sains Malaysiana, 2011;40:1179-1186.
    A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and 1H-NMR as well as the characterization of thermal properties by DSC. High yields of free flowing powder of spherical microcapsules were produced. The synthesized microcapsules can be incorporated into another polymeric host material. In the event the host material cracks due to excessive stress or strong impact, the microcapsules would rupture to release the DCPD, which could polymerize to repair the crack.
    Matched MeSH terms: Urea
  14. Valorization of Technical Lignin for the Production of Desirable Resins with High Substitution Rate and Controllable Viscosity
    Pang B, Lam SS, Shen XJ, Cao XF, Liu SJ, Yuan TQ, et al.
    ChemSusChem, 2020 Sep 07;13(17):4446-4454.
    PMID: 32118355 DOI: 10.1002/cssc.202000299
    The valorization of lignin to replace phenol is significant in the production of phenolic resins. However, a great challenge is to produce lignin-based resin (LR) with a suitable viscosity and high substitution rate of lignin to phenol. In this study, LRs were produced using hardwood technical lignin derived from the pulping industry. Structural analysis of the LRs indicated that the unsubstituted para and ortho carbon atoms of the aromatic ring influenced the curing temperature and activation energy of the resins. The curing kinetics and thermal decomposition study implied that urea and methylene groups in cured LRs were significant factors that affected the thermal stability negatively. The prepared LRs showed desirable features if used as adhesives to make plywood. This is the first approach in which a substitution rate of up to 65 % is achieved for low-reactive-site hardwood lignin, which provides a solution to the challenge of the simultaneous realization of the high addition of lignin and the adaptive viscosity of resins.
    Matched MeSH terms: Urea
  15. Fulltext Physico-mechanical properties and formaldehyde emission of rubberwood particleboard made with UF resin admixed with ammonium and aluminium-based hardeners
    Abd Ghani Aizat, Paiman, Bawon, Lee, Seng Hua, Ashaari Zaidon
    Pertanika Journal of Science & Technology, 2019;27(1):473-488.
    MyJurnal
    In this study, the effects of addition of ammonium and aluminium-based hardeners into
    urea formaldehyde resin (UF) on the physico-mechanical properties and formaldehyde
    emission of the rubberwood particleboard were investigated. Four types of hardeners,
    namely ammonium chloride (AC), ammonium sulphate (AS), aluminium chloride (AlC)
    and aluminium sulphate (AlS), were added into UF resin. The acidity, gelation time,
    viscosity and free formaldehyde content of the UF/hardener mixtures were determined.
    Particleboard made with the UF/hardener mixtures were tested for physico-mechanical
    properties and formaldehyde emission. The pH values of the resin after addition of
    aluminium-based hardeners were higher and resulted in higher viscosity and shorter
    gelation time. Consequently, despite lower formaldehyde emission was recorded, the
    physico-mechanical properties of the resulted particleboard were inferior compared to
    that of ammonium-based hardeners. The best quality particleboard in terms of mechanical,
    physical and formaldehyde emission were obtained from the particleboard made with AS,
    followed by AC.
    Matched MeSH terms: Urea
  16. Fulltext Improvement in the mechanical strength of compacted urea fertilizer tablets through die wall lubrication
    Intan Soraya Shamsudin, Mohd Shamsul Anuar, Ahmad Husni Mohd. Hanif, Yus Aniza Yusof, Suraya Mohd Tahir
    Pertanika Journal of Science & Technology, 2019;27(1):193-203.
    MyJurnal
    This research was conducted to investigate the compaction performance and mechanical
    strength of compacted urea fertilizer in unlubricated and lubricated die systems. The
    ground urea 46% N fertilizer was compacted in a 13 mm flat-face cylindrical die set in
    both unlubricated and lubricated die systems with vegetable fatty acids and magnesium
    stearate as lubricants at various compaction stresses to produce urea fertilizer tablets. In
    conclusion, a lubricated die system reduces the frictional effects during the production of
    urea fertilizer tablets and also produces a mechanically stronger urea fertilizer tablet than
    those produced in an unlubricated die system. In addition, the vegetable fatty acids and
    magnesium stearate lubricants are found to improve the compaction performance of urea
    fertilizer tablet as well as its mechanical strength.
    Matched MeSH terms: Urea
  17. Effects of medicated and non-medicated multi-nutrient block supplementation on gastrointestinal parasite infestation and blood hematological parameters of lactating saanen goats
    Mira Panadi, Nor Dini Rusli, Khairiyah Mat, Wan Zahari Mohamed
    Sains Malaysiana, 2018;47:1447-1453.
    In a 90-day feeding trial, twenty four (24) Saanen lactating does were assigned to four treatment group. The treatments
    were feeding: basal diet only as a control (T1), basal diet with urea molasses multi-nutrient block (UMMB) (T2), basal
    diet with medicated urea molasses multi-nutrient block (MUMB) (T3) and basal diet with commercial mineral block (CMB)
    (T4). There were significant differences (p<0.05) between T2, T3 and T4 on the fecal egg count (FEC). Animals in T2
    and T3 showed moderate level of parasite infestation i.e. at 750 epg and 950 epg, respectively, while animals in T1 and
    T4 showed severe parasite load at 4917 epg and 1850 epg, respectively. There were no significant differences (p>0.05)
    between treatments on WBC, LYM, MON, GRA, RBC, HCT, MCV, MCH, PLT, MPV and PCT. However, significant effects (p<0.05)
    on HBG, MCHC, RDW and PDW were observed in T2 and T3. This research showed that UMMB and MUMB were effective
    in controlling parasite infestation in Saanen lactating dairy goats apart from improving their blood hematological
    parameters. Comparison with CMB showed that it is practical to be used for parasite control.
    Matched MeSH terms: Urea
  18. Fulltext Utilization of an Ionic Liquid/Urea Mixture as a Physical Coupling Agent for Agarose/Talc Composite Films
    Shamsuri AA, Daik R
    Materials (Basel), 2013 Feb 22;6(2):682-698.
    PMID: 28809334 DOI: 10.3390/ma6020682
    An ionic liquid, 1-n-butyl-3-methylimidazolium chloride (BmimCl) was blended with urea at 1:1 mole ratio to create a BmimCl/Urea mixture. The agarose/talc composite films containing the BmimCl/Urea mixture were then acquired through a gelation method. The weight ratio of agarose and talc was fixed at 4:1, while the content of BmimCl/Urea was varied from 0 to 10 wt % relative to the overall weight of the composite films. The tensile stress and modulus results showed the optimum BmimCl/Urea content in the composite film lies at 8 wt %. The talc particles are embedded in the agarose matrix and there are no pullouts for the composite films containing BmimCl/Urea as demonstrated by SEM micrographs. The addition of BmimCl/Urea increased the glass transition temperature of the composite films, however, the thermal decomposition temperature decreased drastically. FTIR and FT-Raman spectra indicated the existence of interaction between agarose and talc, which improves their interfacial adhesion. As a conclusion, a BmimCl/Urea mixture can be utilized as a coupling agent for agarose/talc composite films.
    Matched MeSH terms: Urea
  19. Development of semi-quantitative urinary sodium test strip
    Lai JS, Tan CK, Yusoff K, Cheah SC
    Biotechnol Appl Biochem, 2023 Apr;70(2):603-612.
    PMID: 35830743 DOI: 10.1002/bab.2383
    Excessive salt consumption has been associated with greater risk of hypertension. Therefore, monitoring of dietary sodium consumption should be prioritized. As sodium is mainly excreted through urine, 24-h urine sample can be used to estimate individual sodium intake. Thus, a simple and inexpensive semi-quantitative urinary sodium detection test strip was developed based on the enzymatic reaction between β-galactosidase and chlorophenol red-β-d-galactopyranoside. When tested, color formation was distinguished at 0 M (chartreuse yellow), 0.05 M (sunflower), 0.1-0.15 M (mango tango), and 0.2-0.25 M (persimmon) sodium. Analysis from ImageJ showed a linear result (r2  > 0.9), low SD, and significant increase in magenta difference (p 2 days in adverse storage conditions (laboratory conditions, ∼80% relative humidity, 40°C, and direct light exposure) when stored in test strip bottles, and even shorter when exposed to the environment. The presence of urinary potassium, urea, and glucose did not affect test strip performance. Test strip produced comparable results to flame photometry with <15% variation when tested on overnight, random spot, and 24-h urine samples. Overall, the developed test strip can be used to enzymatically semi-quantify 0.05-0.25 M sodium.
    Matched MeSH terms: Urea
  20. Synthesis of tapioca starch/palm oil encapsulated urea-impregnated biochar derived from peppercorn waste as a sustainable controlled-release fertilizer
    Sim DHH, Tan IAW, Lim LLP, Lau ET, Hameed BH
    Waste Manag, 2024 Jan 01;173:51-61.
    PMID: 37977096 DOI: 10.1016/j.wasman.2023.11.006
    Nutrient leaching and volatilization cause environmental pollution, thus the pursuit of developing controlled-release fertilizer formulation is necessary. Biochar-based fertilizer exhibits slow-release characteristic, however the nutrient release mechanism needs to be improved. To overcome this limitation, the approach of applying encapsulation technology with biochar-based fertilizer has been implemented in this study. Black peppercorn waste was used to synthesize urea-impregnated biochar (UIB). Central composite design was used to investigate the effects of pyrolysis temperature, residence time and urea:biochar ratio on nitrogen content of UIB. The optimum condition to synthesize UIB was at 400 °C pyrolysis temperature, 120 min residence time and 0.6:1 urea:biochar ratio, which resulted in 16.07% nitrogen content. The tapioca starch/palm oil (PO) biofilm formulated using 8 g of tapioca starch and 0.12 µL of PO was coated on the UIB to produce encapsulated urea-impregnated biochar (EUIB). The UIB and EUIB pellets achieved complete release of nitrogen in water after 90 min and 330 min, respectively. The nutrient release mechanism of UIB and EUIB was best described by the Higuchi model and Korsmeyer-Peppas model, respectively. The improvement of water retention ratio of UIB and EUIB pellets was more significant in sandy-textural soil as compared to clayey-textural soil. The EUIB derived from peppercorn waste has the potential to be utilized as a sustainable controlled-release fertilizer for agriculture.
    Matched MeSH terms: Urea
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