Displaying publications 81 - 100 of 314 in total

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  1. Postpartum thromboprophylaxis in a multireligious cohort: a retrospective review of indications and uptake
    Voon HY, Chai MC, Hii LY, Amin R, Suharjono HN
    J Obstet Gynaecol, 2018 May;38(4):493-497.
    PMID: 29433369 DOI: 10.1080/01443615.2017.1389867
    Strategies to prevent mortality from obstetric venous thromboembolism begin with identification, risk stratification and subsequently, implementation of prophylactic measures. We sought to identify the burden of pharmacologic thromboprophylaxis in postpartum women, including the main clinical indications and its uptake in a multireligious population, with Islam as the official religion. A total of 2514 deliveries between 1st January to 31st December 2016, across three centres in Malaysia were reviewed retrospectively from hospital-based registries. 770 (30.62%) patients fulfilled the criteria for thromboprophylaxis based on the revised 2015 criteria proposed by the Royal College of Obstetricians and Gynaecologists. A combination of age, parity, BMI, caesarean section and preterm births were the main indications. One out of the five patients who delivered vaginally required thromboprophylaxis. In our setting with a sizable Muslim population, low molecular weight heparin was the thromboprophylaxis of choice in more than two-third of the patients. The information obtained from this study allows better local resource planning. Impact statement What is already known on this subject: Risk factors for venous thromboembolism in pregnancy and puerperium are largely drawn from registries due to the rarity of the index event. Up to 7% of women require antenatal thromboprophylaxis based on the criteria proposed by the Royal College of Obstetrician and Gynaecologists in 2009. What do the results of this study add: Using the RCOG guideline revised in 2015, a significant proportion of women delivering vaginally would require postnatal thromboprophylaxis based on age, parity and BMI. When either age or parity, both with relatively low odds ratio for thrombosis were omitted, a substantial proportion of women would not achieve the threshold for prophylaxis. Despite a sizable Muslim population in the country, the uptake of low molecular weight heparin was relatively high. What are the implications of these findings for clinical practice and/or future research: Cost-benefit studies should consider the adjusted odds ratio of individual indications on a VTE event. While uptake and acceptability is high, prospective studies on medication adherence is equally pertinent.
    Matched MeSH terms: Heparin, Low-Molecular-Weight/therapeutic use*
  2. Pore size prediction of polyethersulfone ultrafiltration membranes using artificial neural networks
    Ibrahim MZ, Norashikin MZ
    J Nanosci Nanotechnol, 2010 Sep;10(9):6211-5.
    PMID: 21133176
    This paper reports the performance of two different artificial neural networks (ANN), Multi Layer Perceptron (MLP) and Radial Basis Function (RBF) compared to conventional software for prediction of the pore size of the asymmetric polyethersulfone (PES) ultrafiltration membranes. ANN has advantages such as incredible approximation, generalization and good learning ability. The MLP are well suited for multiple inputs and multiple outputs while RBF are powerful techniques for interpolation in multidimensional space. Three experimental data sets were used to train the ANN using polyethylene glycol (PEG) of different molecular weights as additives namely as PEG 200, PEG 400 and PEG 600. The values of the pore size can be determined manually from the graph and solve it using mathematical equation. However, the mathematical solution used to determine the pore size and pore size distribution involve complicated equations and tedious. Thus, in this study, MLP and RBF are applied as an alternative method to estimate the pore size of polyethersulfone (PES) ultrafiltration membranes. The raw data needed for the training are solute separation and solute diameter. Values of solute separation were obtained from the ultrafiltration experiments and solute diameters ware calculated using mathematical equation. With the development of this ANN model, the process to estimate membrane pore size could be made easier and faster compared to mathematical solutions.
    Matched MeSH terms: Molecular Weight
  3. Polysaccharide with antioxidant, α-amylase inhibitory and ACE inhibitory activities from Momordica charantia
    Tan HF, Gan CY
    Int J Biol Macromol, 2016 Apr;85:487-96.
    PMID: 26778156 DOI: 10.1016/j.ijbiomac.2016.01.023
    Functional polysaccharide was isolated from Momordica charantia, with a yield of 36% (w/w). M. charantia bioactive polysaccharide (MCBP) was an acidic and branched heteropolysaccharide with a molecular weight of 92 kDa. Fourier transform infrared spectroscopic analysis indicated that MCBP was a pectin-like polysaccharide with an esterification degree of 53% and it contains numerous monosaccharides, predominantly glucose, galactose, and galaturonic acid. The results also showed that MCBP exhibited free radical scavenging activity (31.9%), ferric reducing antioxidant power (0.95 mM), α-amylase inhibition (89.1%), and angiotensin-converting enzyme inhibition (94.1%). In the terms of functionality, MCBP showed a lower water-holding capacity but higher in oil-holding capacity, emulsifying activity and foaming capacity compared to citrus pectin. Scanning electron microscopy images demonstrated that MCBP formed gels with a porous structure, and flow analysis showed that the gel solution exhibited pseudoplastic shear-thinning behavior. These findings indicated that MCBP is a promising functional macromolecular carbohydrate for the food and nutraceutical industries.
    Matched MeSH terms: Molecular Weight
  4. Fulltext Polymerization degrees, molecular weights and protein-binding affinities of condensed tannin fractions from a Leucaena leucocephala hybrid
    Saminathan M, Tan HY, Sieo CC, Abdullah N, Wong CM, Abdulmalek E, et al.
    Molecules, 2014 Jun 12;19(6):7990-8010.
    PMID: 24927368 DOI: 10.3390/molecules19067990
    Condensed tannins (CTs) form insoluble complexes with proteins and are able to protect them from degradation, which could lead to rumen bypass proteins. Depending on their degrees of polymerization (DP) and molecular weights, CT fractions vary in their capability to bind proteins. In this study, purified condensed tannins (CTs) from a Leucaena leucocephala hybrid were fractionated into five different molecular weight fractions. The structures of the CT fractions were investigated using 13C-NMR. The DP of the CT fractions were determined using a modified vanillin assay and their molecular weights were determined using Q-TOF LC-MS. The protein-binding affinities of the respective CT fractions were determined using a protein precipitation assay. The DP of the five CT fractions (fractions F1-F5) measured by the vanillin assay in acetic acid ranged from 4.86 to 1.56. The 13C-NMR results showed that the CT fractions possessed monomer unit structural heterogeneity. The number-average molecular weights (Mn) of the different fractions were 1265.8, 1028.6, 652.2, 562.2, and 469.6 for fractions F1, F2, F3, F4, and F5, respectively. The b values representing the CT quantities needed to bind half of the maximum precipitable bovine serum albumin increased with decreasing molecular weight--from fraction F1 to fraction F5 with values of 0.216, 0.295, 0.359, 0.425, and 0.460, respectively. This indicated that higher molecular weight fractions of CTs from L. leucocephala have higher protein-binding affinities than those with lower molecular weights.
    Matched MeSH terms: Molecular Weight
  5. Polymer-albumin conjugate for the facilitated delivery of macromolecular platinum drugs
    Dag A, Jiang Y, Karim KJ, Hart-Smith G, Scarano W, Stenzel MH
    Macromol Rapid Commun, 2015 May;36(10):890-7.
    PMID: 25790077 DOI: 10.1002/marc.201400576
    The delivery of macromolecular platinum drugs into cancerous cells is enhanced by conjugating the polymer to albumin. The monomers N-(2-hydroxypropyl)methacrylamide (HPMA) and Boc protected 1,3-diaminopropan-2-yl acrylate (Ac-DAP-Boc) are copolymerized in the presence of a furan protected maleimide functionalized reversible addition-fragmentation chain transfer (RAFT) agent. The resulting polymer with a composition of P(HPMA14 -co-(Ac-DAP-Boc)9 ) and a molecular weight of Mn = 7600 g mol(-1) (Đ = 1.24) is used as a macromolecular ligand for the conjugation to the platinum drug. Thermogravimetric analysis reveals full conjugation. After deprotection of the maleimide functionality of the polymer, the reactive polymer is conjugated to albumin using the Cys34 functionality. The conjugation is monitored using size exclusion chromatography, MALDI-TOF (matrix assisted laser desorption ionization time-of-flight), and SDS Page (sodium dodecyl sulphate polyacrylamide gel electrophoresis). The polymer-albumin conjugates self-assemble in water into nanoparticles of sizes of around 80 nm thanks to the hydrophobic nature of the platinum drugs. The albumin coated nanoparticles are readily taken up by ovarian cancer cell lines and they show superior toxicity compared to a control sample without protein coating.
    Matched MeSH terms: Molecular Weight
  6. Polyhydroxyalkanoate recovery and effect of in situ extracellular polymeric substances removal from aerobic granules
    Gobi K, Vadivelu VM
    Bioresour Technol, 2015;189:169-176.
    PMID: 25889804 DOI: 10.1016/j.biortech.2015.04.023
    Polyhydroxyalkanoate (PHA) recovery from aerobic granules was investigated using four cell digestion agents, namely, sodium hypochlorite, sodium hydroxide, acetone and sodium chloride. Simultaneously, the removal of extracellular polymeric substances (EPS) and its effect on PHA yield were investigated. The highest PHA recovery yield was obtained using sodium hypochlorite, accounting for 89% cell dry weight (CDW). The highest PHA was recovered after the sodium hypochlorite completely removed the EPS from the aerobic granules. The average molecular weight (Mw) of the PHA recovered using sodium hypochlorite was 5.31 × 10(5)g/mol with only 1.8% molecular weight degradation. The energy and duration analysis for PHA recovery revealed that the sodium hypochlorite method required the least amount of energy and time at 0.0561 MJ/g PHA and 26 h, respectively. The PHA that was recovered was a P3(HB-co-HV) co-polymer.
    Matched MeSH terms: Molecular Weight
  7. Fulltext Polyhydroxyalkanoate biosynthesis and simplified polymer recovery by a novel moderately halophilic bacterium isolated from hypersaline microbial mats
    Rathi DN, Amir HG, Abed RM, Kosugi A, Arai T, Sulaiman O, et al.
    J Appl Microbiol, 2013 Feb;114(2):384-95.
    PMID: 23176757 DOI: 10.1111/jam.12083
    Halophilic micro-organisms have received much interest because of their potential biotechnological applications, among which is the capability of some strains to synthesize polyhydroxyalkanoates (PHA). Halomonas sp. SK5, which was isolated from hypersaline microbial mats, accumulated intracellular granules of poly(3-hydroxybutyrate) [P(3HB)] in modified accumulation medium supplemented with 10% (w/v) salinity and 3% (w/v) glucose.
    Matched MeSH terms: Molecular Weight
  8. Pilot scale production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) biopolymers with high molecular weight and elastomeric properties
    Huong KH, Azuraini MJ, Aziz NA, Amirul AA
    J Biosci Bioeng, 2017 Jul;124(1):76-83.
    PMID: 28457658 DOI: 10.1016/j.jbiosc.2017.02.003
    Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [(P(3HB-co-4HB)] copolymer receives attention as next generation biomaterial in medical application. However, the exploitation of the copolymer is still constrained since such copolymer has not yet successfully been performed in industrial scale production. In this work, we intended to establish pilot production system of the copolymer retaining the copolymer quality which has recently discovered to have novel characteristic from lab scale fermentation. An increase of agitation speed has significantly improved the copolymer accumulation efficiency by minimizing the utilization of substrates towards cell growth components. This is evidenced by a drastic increase of PHA content from 28 wt% to 63 wt% and PHA concentration from 3.1 g/L to 6.5 g/L but accompanied by the reduction of residual biomass from 8.0 g/L to 3.8 g/L. Besides, fermentations at lower agitation and aeration have resulted in reduced molecular weight and mechanical strength of the copolymer, suggesting the role of sufficient oxygen supply efficiency in improving the properties of the resulting copolymers. The KLa-based scale-up fermentation was performed successfully in maintaining the yield and the quality of the copolymers produced without a drastic fluctuation. This suggests that the scale-up based on the KLa values supported the fermentation system of P(3HB-co-4HB) copolymer production in single-stage using mixed-substrate cultivation strategy.
    Matched MeSH terms: Molecular Weight
  9. Physicomechanical properties of sintered scaffolds formed from porous and protein-loaded poly(DL-lactic-co-glycolic acid) microspheres for potential use in bone tissue engineering
    Boukari Y, Scurr DJ, Qutachi O, Morris AP, Doughty SW, Rahman CV, et al.
    J Biomater Sci Polym Ed, 2015;26(12):796-811.
    PMID: 26065672 DOI: 10.1080/09205063.2015.1058696
    An injectable poly(DL-lactic-co-glycolic acid) (PLGA) system comprising both porous and protein-loaded microspheres capable of forming porous scaffolds at body temperature was developed for tissue regeneration purposes. Porous and non-porous (lysozyme loaded) PLGA microspheres were formulated to represent 'low molecular weight' 22-34 kDa, 'intermediate molecular weight' (IMW) 53 kDa and 'high molecular weight' 84-109 kDa PLGA microspheres. The respective average size of the microspheres was directly related to the polymer molecular weight. An initial burst release of lysozyme was observed from both microspheres and scaffolds on day 1. In the case of the lysozyme-loaded microspheres, this burst release was inversely related to the polymer molecular weight. Similarly, scaffolds loaded with 1 mg lysozyme/g of scaffold exhibited an inverse release relationship with polymer molecular weight. The burst release was highest amongst IMW scaffolds loaded with 2 and 3 mg/g. Sustained lysozyme release was observed after day 1 over 50 days (microspheres) and 30 days (scaffolds). The compressive strengths of the scaffolds were found to be inversely proportional to PLGA molecular weight at each lysozyme loading. Surface analysis indicated that some of the loaded lysozyme was distributed on the surfaces of the microspheres and thus responsible for the burst release observed. Overall the data demonstrates the potential of the scaffolds for use in tissue regeneration.
    Matched MeSH terms: Molecular Weight
  10. Fulltext Physicochemical characterisation and substrate specificity of purified β-1,6-glucanase from Trichoderma Longibrachiatum
    Muskhazli Mustafa, Nor Azwady Abd. Aziz, Anida Kaimi, Nurul Shafiza Noor, Salifah Hasanah Ahmad Bedawi, Nalisha Ithnin
    Pertanika Journal of Science & Technology, 2009;17(1):-.
    MyJurnal
    The β-1,6-glucanases are ubiquitous enzymes which appear to be implicated in the morphogenesis and have the ability to become virulence factor in plant-fungal symbiotic interaction. To our knowledge, no report on ß-1,6-glucanases purification from Trichoderma longibrachiatum has been made, although it has been proven to have a significant effect as a biocontrol agent for several diseases. Therefore, the aim of this study was to purify β-1,6- glucanase from T. longibrachiatum T28, with an assessment on the physicochemical properties and substrate specificity. β-1,3-glucanase enzyme, from the culture filtrate of T. longibrachiatum T28, was successively purified through precipitation with 80% acetone, followed by anionexchange chromatography on Neobar AQ and chromatofocusing on a Mono P HR 5/20 column. (One β-1,6-glucanase) band at 42kDa in size was purified, as shown by the SDS-PAGE. The physicochemical evaluation showed an optimum pH of 5 and optimum temperature of 50°C for enzyme activity with an ability to maintain 100% enzyme stability. Enzyme activity was slightly reduced by 10-20% in the presence of 20 mM of Zn2+, Ca2+, Co2+, Mg2+, Cu2+, Mn2+ and Fe2+. The highest β-1,6-glucanase hydrolysis activity was obtained on pustulan due to the similarity of β-glucosidic bonds followed by laminarin, glucan and cellulose. Therefore, it can be concluded that the characterization of ß-1,6-glucanase secreted by T. longibrachiatum in term of molecular weight, responsed to selected physicochemical factors and the substrate specificity are approximately identical to other Trichoderma sp.
    Matched MeSH terms: Molecular Weight
  11. Physicochemical and functional properties of Alcalase-extracted protein hydrolysate from oil palm leaves
    Hau EH, Teh SS, Yeo SK, Mah SH
    J Sci Food Agric, 2022 Jan 15;102(1):233-240.
    PMID: 34081335 DOI: 10.1002/jsfa.11350
    BACKGROUND: The oil palm tree produces 90% of wastes and the limited usage of these wastes causes a major disposal problem in the mills. Nevertheless, these by-products have a large amount of nutritional components. Thus, the present study aimed to determine the physicochemical and functional properties of protein hydrolysates (PH) from oil palm leaves (OPL) extracted using different concentrations of Alcalase (0-10%) at 2 h of hydrolysis time.

    RESULTS: Fourier transform infrared spectral analyses showed that the enzymatic hydrolysis altered functional groups of OPL where a secondary amine was present in the PH. Changes were also observed in the thermal stability where the enthalpy heat obtained for PH (933.93-1142.57 J g-1 ) was much lower than OPL (7854.11 J g-1 ). The results showed that the PH extracted by 8% Alcalase exhibited absolute zeta potential, as well as a high emulsifying activity index (70.64 m2  g-1 of protein) and emulsion stability index (60.58 min). Furthermore, this PH showed higher solubility (96.32%) and emulsifying properties compared to other PHs. It is also comparable with commercial plant proteins, indicating that 8% Alcalase is an optimum concentration for hydrolysis.

    CONCLUSION: In summary, the physicochemical and functional properties of PH extracted from OPL showed good functional properties, suggesting that it can be used as an alternative plant protein in food industries. © 2021 Society of Chemical Industry.

    Matched MeSH terms: Molecular Weight
  12. Fulltext Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers
    Yousif E, Al-Amiery AA, Kadihum A, Kadhum AA, Mohamad AB
    Molecules, 2015 Nov 04;20(11):19886-99.
    PMID: 26556323 DOI: 10.3390/molecules201119665
    The photostabilization of polyvinyl chloride (PVC) films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs) for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10(-8). According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV) absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.
    Matched MeSH terms: Molecular Weight
  13. Fulltext Pentocin MQ1: A Novel, Broad-Spectrum, Pore-Forming Bacteriocin From Lactobacillus pentosus CS2 With Quorum Sensing Regulatory Mechanism and Biopreservative Potential
    Wayah SB, Philip K
    Front Microbiol, 2018;9:564.
    PMID: 29636737 DOI: 10.3389/fmicb.2018.00564
    Micrococcus luteus, Listeria monocytogenes, and Bacillus cereus are major food-borne pathogenic and spoilage bacteria. Emergence of antibiotic resistance and consumer demand for foods containing less of chemical preservatives led to a search for natural antimicrobials. A study aimed at characterizing, investigating the mechanism of action and regulation of biosynthesis and evaluating the biopreservative potential of pentocin from Lactobacillus pentosus CS2 was conducted. Pentocin MQ1 is a novel bacteriocin isolated from L. pentosus CS2 of coconut shake origin. The purification strategy involved adsorption-desorption of bacteriocin followed by RP-HPLC. It has a molecular weight of 2110.672 Da as determined by MALDI-TOF mass spectrometry and a molar extinction value of 298.82 M-1 cm-1. Pentocin MQ1 is not plasmid-borne and its biosynthesis is regulated by a quorum sensing mechanism. It has a broad spectrum of antibacterial activity, exhibited high chemical, thermal and pH stability but proved sensitive to proteolytic enzymes. It is potent against M. luteus, B. cereus, and L. monocytogenes at micromolar concentrations. It is quick-acting and exhibited a bactericidal mode of action against its targets. Target killing was mediated by pore formation. We report for the first time membrane permeabilization as a mechanism of action of the pentocin from the study against Gram-positive bacteria. Pentocin MQ1 is a cell wall-associated bacteriocin. Application of pentocin MQ1 improved the microbiological quality and extended the shelf life of fresh banana. This is the first report on the biopreservation of banana using bacteriocin. These findings place pentocin MQ1 as a potential biopreservative for further evaluation in food and medical applications.
    Matched MeSH terms: Molecular Weight
  14. Fulltext Partially Reversible Acute Renal Cortical Necrosis Secondary to Hyperhomocysteinemia - A Case Report and Literature Review
    Tan W, Abd Ghani F, Seong Lim CT
    Indian J Nephrol, 2019 8 20;29(4):288-290.
    PMID: 31423065 DOI: 10.4103/ijn.IJN_153_18
    Acute renal cortical necrosis (ACN) is a potentially fatal renal condition. Our objective is to report a case of ACN in a young man who had developed premature atherosclerotic vascular disease and required intermittent hemodialysis support. His renal biopsy showed diffuse cortical necrosis. Subsequently, 2 weeks after the renal insult, he developed a cardioembolic stroke and was anticoagulated with low-molecular-weight heparin. Thrombophilia screen revealed elevated serum homocystein and he was treated with folate supplement and vitamin B12 injection. With these treatments, he had partial renal recovery and became dialysis independent. In conclusion, this is a rare case of ACN, which may have occurred as a complication of hyperhomocysteinemia.
    Matched MeSH terms: Heparin, Low-Molecular-Weight
  15. Fulltext Partial purification of the molybdenum-reducing enzyme from Bacillus pumilus strain Lbna
    Abo-Shakeer, L.K.A., Yakasai, M.H., Rahman, M.F., Syed, M.A., Bakar, N.A., Othman, A.R.
    Bioremediation Science and Technology Research, 2016;4(1):14-17.
    MyJurnal
    Molybdenum is an emerging pollutant. Bioremediation of this heavy metal is possible by the
    mediation of Mo-reducing bacteria. These bacteria contain the Mo-reducing enzymes that can
    conver toxic soluble molybdenum into molybdenum blue; a less soluble and less toxic form of the
    metal. To date only the enzyme has been purified from only one bacterium. The aim of this study is
    to purify the Mo-reducing enzyme from a previously isolated Mo-reducing bacterium Bacillus
    pumilus strain Lbna using ammonium sulphate fractionation followed by ion exchange and then
    gel filtration. Two clear bands were obtained after the gel filtration step with molecular weights
    of 70 and 100 kDa. This indicates that further additional purification methods need to be used
    to get a purified fraction. Hence, additional steps of chromatography such as hydroxyapatite or
    chromatofocusing techniques can be applied in the future.
    Matched MeSH terms: Molecular Weight
  16. Fulltext Partial Purification and Characterisation of Pectinase Produced by Aspergillus niger LFP-1 Grown on Pomelo Peels as a Substrate
    Jalil MTM, Ibrahim D
    Trop Life Sci Res, 2021 Mar;32(1):1-22.
    PMID: 33936548 DOI: 10.21315/tlsr2021.32.1.1
    In the present study, pectinase was produced by local fungal isolate, Aspergillus niger LFP-1 grown on pomelo peels as a sole carbon source under solid-state fermentation (SSF). The purification process begins with the concentration of crude enzyme using ammonium sulfate precipitation and followed by purification using anion-exchange column chromatography (DEAE-Sephadex) and subsequently using gel filtration column chromatography (Sephadex G-100). On the other hand, the molecular weight of the purified enzyme was determined through SDS-PAGE. The findings revealed the crude enzyme was purified up to 75.89 folds with a specific activity of 61.54 U/mg and the final yield obtained was 0.01%. The molecular mass of the purified pectinase was 48 kDa. The optimum pH and temperature were 3.5 and 50°C, respectively. This enzyme was stable at a range of pH 3.5 to 4.5 and a relatively high temperature (40°C-50°C) for 100 min. The Km and Vmax were found to be 3.89 mg/mL and 1701 U/mg, respectively. Meanwhile, pectin from citrus fruit and the metal ion (Co2+) were the best substrate and inducer to enhance pectinase yield, respectively.
    Matched MeSH terms: Molecular Weight
  17. Parametric optimization of polycaprolactone synthesis catalysed by Candida antarctica lipase B using response surface methodology
    Pakalapati H, Arumugasamy SK, Jewaratnam J, Wong YJ, Khalid M
    Biopolymers, 2018 Dec;109(12):e23240.
    PMID: 30489632 DOI: 10.1002/bip.23240
    A statistical approach with D-optimal design was used to optimize the process parameters for polycaprolactone (PCL) synthesis. The variables selected were temperature (50°C-110°C), time (1-7 h), mixing speed (50-500 rpm) and monomer/solvent ratio (1:1-1:6). Molecular weight was chosen as response and was determined using matrix-assisted laser desorption/ionization time of flight (MALDI TOF). Using the D-optimal method in design of experiments, the interactions between parameters and responses were analysed and validated. The results show a good agreement with a minimum error between the actual and predicted values.
    Matched MeSH terms: Molecular Weight
  18. Fulltext PRELIMINARY STUDY OF 4-ARMS POLY(CAPROLACTONE) STAR- SHAPED POLYMER: SYNTHESIS AND CHARACTERIZATION
    Siti Hajar Ahmad Shariff, Mohamad Wafiuddin Ismail
    Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):127-138.
    MyJurnal
    Star-shaped polymers have vast potential in bioapplication due to their architecture. In this study, the suitability of ring opening polymerization (ROP) technique to synthesis star-shaped poly(caprolactone) and the thermal properties of the synthesized star-shaped polymers were demonstrated. The 4 -arm star- shaped of poly(caprolactone) (4s PCL) with -OH terminal and average molecular weight (Mn) of 5000, 10000, and 15000 g/mol were synthesized via ROP of ԑ-caprolactone (ԑ-CL) using a symmetric pentaerythritol (PET) as the core. Different molecular weights were obtained by using different ratios of ԑ-CL and PET in the presence of catalyst, stannous octoate (Sn(Oct)2). The FTIR spectra showed the presence of bands of methylene group of polymer repeating chain which confirm ROP of the ԑ- caprolactone. The average molecular weight (Mn) determined from proton nuclear magnetic resonance (1H NMR) analysis showed that all 4s PCL have approximately the same molecular weight as the theoretical values. All polymers obtained had high yield with >85%. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis showed that there were no significance different in the thermal properties of the synthesized polymers. A single step degradation for all 4s PCL was observed and the crystallization melting point of the polymers was within the range of melting point of PCL.
    Matched MeSH terms: Molecular Weight
  19. Fulltext PH levels effect on functional properties of different molecular weight eel (Monopterus sp.) protein hydrolysate
    Samsudin NA, Halim NRA, Sarbon NM
    J Food Sci Technol, 2018 Nov;55(11):4608-4614.
    PMID: 30333657 DOI: 10.1007/s13197-018-3399-0
    The aim of this study is to investigate the effect of pH levels on functional properties of various molecular weights of eel (Monopterus sp.) protein hydrolysate (EPH). The eel was enzymatically hydrolyzed and fractionated through membranes filter (10 kDa, 5 kDa and 3 kDa). The foaming capacity and stability, emulsifying capacity and stability index, water holding capacity and fat binding capacity between pH 2 and 10 were determined. The 5 kDa EPH was found to have the highest foaming capacity at pH 2, pH 4 and pH 6, and foaming stability and emulsifying activity index at all pH levels, except pH 8 and fat binding capacity at pH 2, as compared to 10 kDa and 3 kDa EPH fractions. The 10 kDa EPH had the highest emulsifying stability index and water holding capacity at all pH levels. This study shows that the EPH fractions at low pH level had high foaming and oil binding capacity, while at neutral pH, the fractions had high foaming stability and water holding capacity. These properties are important in making whipped cream, mousse and meringue. In contrast, EPH fractions demonstrated strong emulsifying properties at high pH levels and show potential as an emulsifier for breads, biscuits and frozen desserts.
    Matched MeSH terms: Molecular Weight
  20. Fulltext Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production
    Tajabadi N, Baradaran A, Ebrahimpour A, Rahim RA, Bakar FA, Manap MY, et al.
    Microb Biotechnol, 2015 Jul;8(4):623-32.
    PMID: 25757029 DOI: 10.1111/1751-7915.12254
    Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products.
    Matched MeSH terms: Molecular Weight
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