Browse publications by year: 2014

  1. Nga AD, Yap SL, Samsudin A, Abdul-Rahman PS, Hashim OH, Mimiwati Z
    BMC Ophthalmol, 2014;14:33.
    PMID: 24655889 DOI: 10.1186/1471-2415-14-33
    Altered levels of specific matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in the aqueous humour of primary open-angle glaucoma (POAG) eyes have been described. In this study, levels of specific MMPs and TIMPs in the aqueous humour of primary angle-closure glaucoma (PACG) eyes were measured and compared with those of POAG as well as non-glaucoma control eyes.
    MeSH terms: Aged; Aqueous Humor/metabolism*; Cross-Sectional Studies; Female; Humans; Intraoperative Period; Male; Middle Aged; Glaucoma, Angle-Closure/metabolism*; Case-Control Studies; Matrix Metalloproteinase 3/metabolism*; Tissue Inhibitor of Metalloproteinase-1/metabolism*; Tissue Inhibitor of Metalloproteinase-2/metabolism*; Matrix Metalloproteinase 2/metabolism*
  2. Bernardini-Zambrini DA
    Semergen, 2014 May-Jun;40(4):175-6.
    PMID: 24656551 DOI: 10.1016/j.semerg.2014.01.008
    MeSH terms: Humans; Mental Health*; Politics; Public Health/legislation & jurisprudence*; Public Policy/legislation & jurisprudence*; Violence/statistics & numerical data
  3. Ismail NA, Baines DL, Wilson SM
    Eur J Pharmacol, 2014 Jun 05;732:32-42.
    PMID: 24657276 DOI: 10.1016/j.ejphar.2014.03.005
    Neural precursor cell expressed, developmentally down-regulated protein 4-2 (Nedd4-2) mediates the internalisation / degradation of epithelial Na(+) channel subunits (α-, β- and γ-ENaC). Serum / glucocorticoid inducible kinase 1 (SGK1) and protein kinase A (PKA) both appear to inhibit this process by phosphorylating Nedd4-2-Ser(221), -Ser(327) and -Thr(246). This Nedd4-2 inactivation process is thought to be central to the hormonal control of Na(+) absorption. The present study of H441 human airway epithelial cells therefore explores the effects of SGK1 and / or PKA upon the phosphorylation / abundance of endogenous Nedd4-2; the surface expression of ENaC subunits, and electrogenic Na(+) transport. Effects on Nedd4-2 phosphorylation/abundance and the surface expression of ENaC were monitored by western analysis, whilst Na(+) absorption was quantified electrometrically. Acutely (20min) activating PKA in glucocorticoid-deprived (24h) cells increased the abundance of Ser(221)-phosphorylated, Ser(327)-phosphorylated and total Nedd4-2 without altering the abundance of Thr(246)-phosphorylated Nedd4-2. Activating PKA under these conditions did not cause a co-ordinated increase in the surface abundance of α-, β- and γ-ENaC and had only a very small effect upon electrogenic Na(+) absorption. Activating PKA (20min) in glucocorticoid-treated (0.2µM dexamethasone, 24h) cells, on the other hand, increased the abundance of Ser(221)-, Ser(327)- and Thr(246)-phosphorylated and total Nedd4-2; increased the surface abundance of α-, β- and γ-ENaC and evoked a clear stimulation of Na(+) transport. Chronic glucocorticoid stimulation therefore appears to allow cAMP-dependent control of Na(+) absorption by facilitating the effects of PKA upon the Nedd4-2 and ENaC subunits.
    MeSH terms: Cyclic AMP/agonists; Anti-Inflammatory Agents/pharmacology; Cell Line; Dexamethasone/pharmacology; Epithelial Cells/drug effects; Epithelial Cells/metabolism*; Humans; Phosphorylation; Sodium/metabolism; Protein-Serine-Threonine Kinases/metabolism; Cyclic AMP-Dependent Protein Kinases/metabolism; Immediate-Early Proteins/metabolism; Respiratory Mucosa/drug effects; Respiratory Mucosa/metabolism*; Ubiquitin-Protein Ligases/drug effects; Ubiquitin-Protein Ligases/metabolism*; Epithelial Sodium Channels/drug effects; Epithelial Sodium Channels/metabolism; Endosomal Sorting Complexes Required for Transport/drug effects; Endosomal Sorting Complexes Required for Transport/metabolism*
  4. Rajisha KR, Maria HJ, Pothan LA, Ahmad Z, Thomas S
    Int J Biol Macromol, 2014 Jun;67:147-53.
    PMID: 24657376 DOI: 10.1016/j.ijbiomac.2014.03.013
    Potato starch nanocrystals were found to serve as an effective reinforcing agent for natural rubber (NR). Starch nanocrystals were obtained by the sulfuric acid hydrolysis of potato starch granules. After mixing the latex and the starch nanocrystals, the resulting aqueous suspension was cast into film by solvent evaporation method. The composite samples were successfully prepared by varying filler loadings, using a colloidal suspension of starch nanocrystals and NR latex. The morphology of the nanocomposite prepared was analyzed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). FESEM analysis revealed the size and shape of the crystal and their homogeneous dispersion in the composites. The crystallinity of the nanocomposites was studied using XRD analysis which indicated an overall increase in crystallinity with filler content. The mechanical properties of the nanocomposites such as stress-strain behavior, tensile strength, tensile modulus and elongation at break were measured according to ASTM standards. The tensile strength and modulus of the composites were found to improve tremendously with increasing nanocrystal content. This dramatic increase observed can be attributed to the formation of starch nanocrystal network. This network immobilizes the polymer chains leading to an increase in the modulus and other mechanical properties.
    MeSH terms: Latex/chemistry; Polymers/chemistry*; Solanum tuberosum/chemistry; Rubber/chemistry; Starch/chemistry*; Nanoparticles/chemistry*; Nanocomposites/chemistry*
  5. Dallai R, Gottardo M, Mercati D, Machida R, Mashimo Y, Matsumura Y, et al.
    Arthropod Struct Dev, 2014 Jul;43(4):371-83.
    PMID: 24657729 DOI: 10.1016/j.asd.2014.03.001
    The male and female reproductive apparatus of Zorotypus magnicaudelli (Malaysia), Zorotypus huxleyi (Ecuador) and Zorotypus weidneri (Brazil) were examined and documented in detail. The genital apparatus and sperm of the three species show only minor differences. The testes are larger in Z. magnicaudelli. Z. huxleyi lacks the helical appendage in the accessory glands. A long cuticular flagellum is present in Z. magnicaudelli and in the previously studied Zorotypus caudelli like in several other species, whereas it is absent in Z. weidneri, Z. huxleyi, Zorotypus hubbardi, Zorotypus impolitus and Zorotypus guineensis. Characteristic features of the very similar sperm are the presence of: a) two dense arches above the axoneme; b) a 9 + 9+2 axoneme with detached subtubules A and B of doublets 1 and 6; c) the axonemal end degenerating with enlarging accessory tubules; d) accessory tubules with 17 protofilaments; e) three accessory bodies beneath the axoneme; and f) two mitochondrial derivatives of equal shape. The first characteristic (a) is unknown outside of Zoraptera and possibly autapomorphic. The sperm structure differs distinctly in Z. impolitus and Z. hubbardi, which produce giant sperm and possess a huge spermatheca. The presence of the same sperm type in species either provided with a sclerotized coiled flagellum in males or lacking this structure indicates that a different organization of the genital apparatus does not necessarily affect the sperm structure. The flagellum and its pouch has probably evolved within Zoraptera, but it cannot be excluded that it is a groundplan feature and was reduced several times. The fossil evidence and our findings suggest that distinct modifications in the genital apparatus occurred before the fragmentation of the Gondwanan landmass in the middle Cretaceous.
    MeSH terms: Africa; Animals; Biological Evolution*; Female; Genitalia, Female/anatomy & histology; Genitalia, Female/cytology; Genitalia, Male/anatomy & histology; Genitalia, Male/cytology; Insects/anatomy & histology*; Insects/cytology; Insects/ultrastructure; Malaysia; Male; South America; Species Specificity; Spermatozoa/ultrastructure
  6. Tripathi BM, Lee-Cruz L, Kim M, Singh D, Go R, Shukor NA, et al.
    Microb Ecol, 2014 Aug;68(2):247-58.
    PMID: 24658414
    Spatial scaling to some extent determines biodiversity patterns in larger organisms, but its role in microbial diversity patterns is much less understood. Some studies have shown that bacterial community similarity decreases with distance, whereas others do not support this. Here, we studied soil bacterial communities of tropical rainforest in Malaysia at two spatial scales: a local scale with samples spaced every 5 mover a 150-m transect, and a regional scale with samples 1 to 1,800 km apart. PCR-amplified soil DNA for the bacterial 16S rRNA gene targeting the V1–V3 region was pyrosequenced using Roche/454 GS FLX Titanium platform. A ranked partial Mantel test showed a weak correlation between spatial distance and whole bacterial community dissimilarity, but only at the local scale. In contrast, environmental distance was highly correlated with community dissimilarity at both spatial scales,stressing the greater role of environmental variables rather than spatial distance in determining bacterial community variation at different spatial scales. Soil pH was the only environmental parameter that significantly explained the variance in bacterial community at the local scale, whereas total nitrogen and elevation were additional important factors at the regional scale.We obtained similar results at both scales when only the most abundant OTUs were analyzed. A variance partitioning analysis showed that environmental variables contributed more to bacterial community variation than spatial distance at both scales. In total, our results support a strong influence of the environment in determining bacterial community composition in the rainforests of Malaysia. However, it is possible that the remaining spatial distance effect is due to some of the myriad of other environmental factors which were not considered here, rather than dispersal limitation.
    MeSH terms: Bacteria/classification; Bacteria/growth & development*; DNA, Bacterial/genetics; Malaysia; RNA, Ribosomal, 16S/genetics; Soil/chemistry; Soil Microbiology*; Biodiversity*; Spatial Analysis; Forests*
  7. Yea CS, Ebrahimpour A, Hamid AA, Bakar J, Muhammad K, Saari N
    Food Funct, 2014 May;5(5):1007-16.
    PMID: 24658538 DOI: 10.1039/c3fo60667h
    Hypertension is one of the major causes of cardiovascular-related diseases, which is highly associated with angiotensin-I-converting enzyme (ACE) activity and oxidative stress. In this study, winged bean seed (WBS), a potential source of protein, was utilised for the production of bifunctional proteolysate and biopeptides with ACE inhibitory and antioxidative properties. An enzymatic approach was applied, coupled with pretreatment of shaking and centrifuging techniques to remove endogenous ACE inhibitors prior to proteolysis. ACE inhibition reached its highest activity, 78.5%, after 12 h proteolysis while antioxidative activities, determined using assays involving DPPH˙ radical scavenging activity and metal ion-chelating activity, reached peaks of 65.0% and 65.7% at 8 h and 14 h, respectively. The said bioactivities were proposed to share some common structural requirements among peptides. A two-dimensional approach was employed for characterisation of effective peptides based on hydrophobicity, using RP-HPLC, and isoelectric property, using isoelectric focusing technique. Results revealed that acidic and basic peptides with partially higher hydrophobicity provided higher ACE inhibition activity than did neutral peptides. Finally, by using Q-TOF mass spectrometry, two peptide sequences (YPNQKV and FDIRA) with ACE inhibitory and antioxidative activities were successfully matched with a database. This study indicates that the WBS proteolysate can be a potential bifunctional food ingredient as the identified biopeptides demonstrated both ACE inhibitory and antioxidative activities in vitro.
    MeSH terms: Angiotensin-Converting Enzyme Inhibitors/isolation & purification; Angiotensin-Converting Enzyme Inhibitors/chemistry*; Antihypertensive Agents/isolation & purification; Antihypertensive Agents/chemistry*; Antioxidants/isolation & purification; Antioxidants/chemistry; Hydrolysis; Peptidyl-Dipeptidase A/metabolism; Peptidyl-Dipeptidase A/chemistry; Fabaceae/chemistry*; Plant Proteins/isolation & purification; Plant Proteins/chemistry*; Protein Hydrolysates/isolation & purification; Protein Hydrolysates/chemistry; Seeds/chemistry*
  8. Shakir RM, Ariffin A, Abdulla MA
    Molecules, 2014;19(3):3436-49.
    PMID: 24658568 DOI: 10.3390/molecules19033436
    Eleven new 2,6-di-tert-butyl-4-(5-aryl-1,3,4-oxadiazol-2-yl)phenols 5a-k were synthesized by reacting aryl hydrazides with 3,5-di-tert butyl 4-hydroxybenzoic acid in the presence of phosphorus oxychloride. The resulting compounds were characterized based on their IR, ¹H-NMR, ¹³C-NMR, and HRMS data. 2,2-Diphenyl-1-picrylhydrazide (DPPH) and ferric reducing antioxidant power (FRAP) assays were used to test the antioxidant properties of the compounds. Compounds 5f and 5j exhibited significant free-radical scavenging ability in both assays.
    MeSH terms: Antioxidants/chemical synthesis*; Antioxidants/pharmacology*; Biphenyl Compounds/antagonists & inhibitors; Oxadiazoles/chemical synthesis*; Oxadiazoles/pharmacology*; Phenols/chemistry*; Picrates/antagonists & inhibitors; Inhibitory Concentration 50
  9. Akbarzadeh S, Arof AK, Ramesh S, Khanmirzaei MH, Nor RM
    PLoS One, 2014;9(3):e92241.
    PMID: 24658582 DOI: 10.1371/journal.pone.0092241
    Electrochemical impedance spectroscopy (EIS) is a key method for the characterizing the ionic and electronic conductivity of materials. One of the requirements of this technique is a model to forecast conductivity in preliminary experiments. The aim of this paper is to examine the prediction of conductivity by neuro-fuzzy inference with basic experimental factors such as temperature, frequency, thickness of the film and weight percentage of salt. In order to provide the optimal sets of fuzzy logic rule bases, the grid partition fuzzy inference method was applied. The validation of the model was tested by four random data sets. To evaluate the validity of the model, eleven statistical features were examined. Statistical analysis of the results clearly shows that modeling with an adaptive neuro-fuzzy is powerful enough for the prediction of conductivity.
    MeSH terms: Electric Conductivity*; Iodides/chemistry; Models, Theoretical; Starch/chemistry; Neural Networks (Computer)*; Fuzzy Logic; Dielectric Spectroscopy*
  10. Akbari E, Buntat Z, Ahmad MH, Enzevaee A, Yousof R, Iqbal SM, et al.
    Sensors (Basel), 2014;14(3):5502-15.
    PMID: 24658617 DOI: 10.3390/s140305502
    Carbon Nanotubes (CNTs) are generally nano-scale tubes comprising a network of carbon atoms in a cylindrical setting that compared with silicon counterparts present outstanding characteristics such as high mechanical strength, high sensing capability and large surface-to-volume ratio. These characteristics, in addition to the fact that CNTs experience changes in their electrical conductance when exposed to different gases, make them appropriate candidates for use in sensing/measuring applications such as gas detection devices. In this research, a model for a Field Effect Transistor (FET)-based structure has been developed as a platform for a gas detection sensor in which the CNT conductance change resulting from the chemical reaction between NH3 and CNT has been employed to model the sensing mechanism with proposed sensing parameters. The research implements the same FET-based structure as in the work of Peng et al. on nanotube-based NH3 gas detection. With respect to this conductance change, the I-V characteristic of the CNT is investigated. Finally, a comparative study shows satisfactory agreement between the proposed model and the experimental data from the mentioned research.
    MeSH terms: Adsorption; Ammonia/analysis; Gases/analysis*; Temperature; Transistors, Electronic; Nanotechnology/instrumentation*; Nanotechnology/methods*; Nanotubes, Carbon/chemistry*
  11. Ord TJ, Klomp DA
    Oecologia, 2014 Jun;175(2):651-66.
    PMID: 24658764
    Sympatric species that initially overlap in resource use are expected to partition the environment in ways that will minimize interspecific competition. This shift in resource use can in turn prompt evolutionary changes in morphology. A classic example of habitat partitioning and morphological differentiation are the Caribbean Anolis lizards. Less well studied, but nevertheless striking analogues to the Anolis are the Southeast Asian Draco lizards. Draco and Anolis have evolved independently of each other for at least 80 million years. Their comparison subsequently offers a special opportunity to examine mechanisms of phenotypic differentiation between two ecologically diverse, but phylogenetically distinct groups. We tested whether Draco shared ecological axes of differentiation with Anolis (e.g., habitat use), whether this differentiation reflected interspecific competition, and to what extent adaptive change in morphology has occurred along these ecological axes. Using existing data on Anolis, we compared the habitat use and morphology of Draco in a field study of allopatric and sympatric species on the Malay Peninsula, Borneo and in the Philippines. Sympatric Draco lizards partitioned the environment along common resource axes to the Anolis lizards, especially in perch use. Furthermore, the morphology of Draco was correlated with perch use in the same way as it was in Anolis: species that used wider perches exhibited longer limb lengths. These results provide an important illustration of how interspecific competition can occur along common ecological axes in different animal groups, and how natural selection along these axes can generate the same type of adaptive change in morphology.
    MeSH terms: Animals; Borneo; Biological Evolution; Lizards/anatomy & histology*; Malaysia; Phylogeny; Selection, Genetic*; Caribbean Region; Ecosystem
  12. Mohamad Yadzir ZH, Misnan R, Abdullah N, Bakhtiar F, Leecyous B, Murad S
    Iran J Allergy Asthma Immunol, 2014 Aug;13(4):240-6.
    PMID: 24659159
    Component-resolved diagnosis (CRD) using microarray technology has recently been introduced with the aim to improve diagnosis of allergy. The aim of this study was to compare performance of this allergen microarray to those of an established extract-based skin prick testing (SPT).45 patients with allergic rhinitis were studied (16 children and 29 adults). SPT to Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis extracts and allergen microarray ImmunoCAP ISAC were carried out for all patients. Forty out of 45 patients demonstrated positive SPT to all mite extracts tested. These 40 patients were considered to be mite-allergic based on the positive SPT results. The remaining 5 patients with negative SPT to any mite extracts were classified as non-mite allergic. Comparatively, based on the microarray results, only 34 mite-allergic patients had detectable serum IgE to at least one of the mite allergen components tested whereas 6 patients with positive SPT to mite extracts showed no detectable IgE reactivity to any of the components tested. One non-mite allergic patient had a positive test- Blo t 5. Der p 10-positive patients also reacted to other cross-reactive tropomyosin from anisakis (Ani s 3) (25%), cockroach (Bla g 7) (50%) and shrimp (Pen m 1) (75%). CRD is a reliable tool for the diagnosis of allergy to mites. Der p 10 might be a useful indicator to identify a subset of mite-allergic patient that have additional sensitization due to cross-reactivity and thus allows selection of patients for immunotherapy.
    MeSH terms: Adolescent; Adult; Aged; Animals; Child; Cross Reactions; Humans; Hypersensitivity/diagnosis*; Immunoglobulin E/blood; Middle Aged; Mites/immunology*; Skin Tests; Dermatophagoides farinae/immunology; Dermatophagoides pteronyssinus/immunology; Protein Array Analysis; Rhinitis, Allergic/diagnosis*
  13. Elnager A, Abdullah WZ, Hassan R, Idris Z, Wan Arfah N, Sulaiman SA, et al.
    Adv Hematol, 2014;2014:814684.
    PMID: 24660000 DOI: 10.1155/2014/814684
    This study aimed to evaluate in vitro whole blood (WB) clot lysis method for the assessment of fibrinolytic activity. Standardized unresected (uncut) retracted WB clot was incubated in pool platelet poor plasma (PPP) for varying incubation times and in streptokinase (SK) at different concentrations. The fibrinolytic activity was assessed by D-dimer (DD), confocal microscopy, and clot weight. DD was measured photometrically by immunoturbidimetric method. There was a significant difference in mean DD levels according to SK concentrations (P = 0.007). The mean DD ± SD according to the SK concentrations of 5, 30, 50, and 100 IU/mL was: 0.69 ± 0.12, 0.78 ± 0.14, 1.04 ± 0.14 and 2.40 ± 1.09  μ g/mL. There were no significant changes of clot weight at different SK concentrations. Gradual loss and increased branching of fibrin in both PPP and SK were observed. Quantitation of DD and morphology of fibrin loss as observed by the imaging features are in keeping with fibrinolytic activity. Combination of DD levels and confocal microscopic features was successfully applied to evaluate the in vitro WB clot lysis method described here.
  14. Budianto IR, Tan HL, Kinoshita Y, Tamba RP, Leiri S, Taguchi T
    Asian J Surg, 2014 Oct;37(4):200-4.
    PMID: 24661449 DOI: 10.1016/j.asjsur.2014.01.013
    Undescended testes is one of the most common congenital abnormalities in boys. In cases of impalpable testes, ultrasound is often used to find the testis, which frequently provides false-negative results. Recently, laparoscopy has become popular in the management of impalpable testes.
    MeSH terms: Adolescent; Child; Child, Preschool; Cryptorchidism/diagnosis; Cryptorchidism/surgery*; Cryptorchidism/ultrasonography*; Gonadal Dysgenesis, 46,XY/diagnosis*; Gonadal Dysgenesis, 46,XY/ultrasonography*; Humans; Infant; Male; Orchiectomy; Laparoscopy; Retrospective Studies; Scrotum; Testis/abnormalities*; Testis/surgery*; Testis/ultrasonography
  15. Abdollahi A, Abu Talib M, Yaacob SN, Ismail Z
    J Psychiatr Ment Health Nurs, 2014;21(9):789-96.
    PMID: 24661763 DOI: 10.1111/jpm.12142
    The relevance of the study of happiness and stress in nurses has been emphasized. In this sense, the intelligent use of hardiness is enable nurses to cope better with stress and contribute to being happier. This study aimed to examine the relationship among hardiness, perceived stress, and happiness in nurses. Moreover, we examined the mediator role of hardiness on the relationship between perceived stress and happiness in nurses. Our study revealed that hardi-attitude nurses evaluate situations as less stressful which results in a higher happiness. This study showed hardiness as being a protective factor against perceived stress and a facilitating factor for happiness in nurses. The findings could be important in training future nurses so that hardiness can be imparted, thereby giving them the ability to control their stress. Nursing is a stressful occupation with high levels of stress within the health professions. Given that hardiness is an important construct to enable nurses to cope better with stress and contribute to being happier; therefore, it is necessary we advance our knowledge about the aetiology of happiness, especially the role of hardiness in decreasing stress levels and increasing happiness. The present study sought to investigate the role of hardiness as a mediator between perceived stress and happiness. The participants, comprising 252 nurses from six private hospitals in Tehran, completed the Personal Views Survey, the Perceived Stress Scale, and the Oxford Happiness Inventory. Structural Equation Modelling (SEM) was used to analyse the data and answer the research hypotheses. As expected, hardiness partially mediated between perceived stress and happiness among nurses, and nurses with low levels of perceived stress were more likely to report greater hardiness and happiness. In addition, nurses with high levels of hardiness were more likely to report happiness. This study showed hardiness as being a protective factor against perceived stress and a facilitating factor for happiness in nurses. The findings could be important in training future nurses so that hardiness can be imparted, thereby giving them the ability to control their stress.
    MeSH terms: Adolescent; Adult; Female; Happiness*; Humans; Male; Middle Aged; Nurses/psychology*; Stress, Psychological/psychology*; Resilience, Psychological*; Young Adult
  16. Cheung CM, Li X, Cheng CY, Zheng Y, Mitchell P, Wang JJ, et al.
    Ophthalmology, 2014 Aug;121(8):1598-603.
    PMID: 24661862 DOI: 10.1016/j.ophtha.2014.02.004
    To describe the prevalence and risk factors for age-related macular degeneration (AMD) in a multiethnic Asian cohort of Chinese, Malay, and Indian persons.
    MeSH terms: Adult; Aged; Aged, 80 and over; Cross-Sectional Studies; Ethnic Groups/ethnology*; Female; Humans; India/ethnology; Macular Degeneration/classification; Macular Degeneration/ethnology*; Malaysia/ethnology; Male; Middle Aged; Photography; Risk Factors; Singapore/epidemiology; Prevalence; Asian Continental Ancestry Group/ethnology
  17. El Hassane A, Shah SA, Hassan NB, El Moussaoui N, Ahmad R, Zulkefeli M, et al.
    Molecules, 2014;19(3):3489-507.
    PMID: 24662069 DOI: 10.3390/molecules19033489
    Hispidin oligomers are styrylpyrone pigments isolated from the medicinal fungi Inonotus xeranticus and Phellinus linteus. They exhibit diverse biological activities and strong free radical scavenging activity. To rationalize the antioxidant activity of a series of four hispidin oligomers and determine the favored mechanism involved in free radical scavenging, DFT calculations were carried out at the B3P86/6-31+G (d, p) level of theory in gas and solvent. The results showed that bond dissociation enthalpies of OH groups of hispidin oligomers (ArOH) and spin density delocalization of related radicals (ArO•) are the appropriate parameters to clarify the differences between the observed antioxidant activities for the four oligomers. The effect of the number of hydroxyl groups and presence of a catechol moiety conjugated to a double bond on the antioxidant activity were determined. Thermodynamic and kinetic studies showed that the PC-ET mechanism is the main mechanism involved in free radical scavenging. The spin density distribution over phenoxyl radicals allows a better understanding of the hispidin oligomers formation.
    MeSH terms: Antioxidants/pharmacology; Antioxidants/chemistry*; Catechols/chemistry; Fungi/chemistry*; Hydrogen Bonding; Isomerism; Models, Molecular; Pyrones/pharmacology; Pyrones/chemistry*; Thermodynamics; Dimerization; Quantitative Structure-Activity Relationship
  18. Amid M, Manap Y, Zohdi NK
    Molecules, 2014;19(3):3731-43.
    PMID: 24662085 DOI: 10.3390/molecules19033731
    Amylase is one of the most important enzymes in the world due to its wide application in various industries and biotechnological processes. In this study, amylase enzyme from Hylocereus polyrhizus was encapsulated for the first time in an Arabic gum-chitosan matrix using freeze drying. The encapsulated amylase retained complete biocatalytic activity and exhibited a shift in the optimum temperature and considerable increase in the pH and temperature stabilities compared to the free enzyme. Encapsulation of the enzyme protected the activity in the presence of ionic and non-ionic surfactants and oxidizing agents (H₂O₂) and enhanced the shelf life. The storage stability of amylase is found to markedly increase after immobilization and the freeze dried amylase exhibited maximum encapsulation efficiency value (96.2%) after the encapsulation process. Therefore, the present study demonstrated that the encapsulation of the enzyme in a coating agent using freeze drying is an efficient method to keep the enzyme active and stable until required in industry.
    MeSH terms: Amylases/isolation & purification*; Amylases/metabolism; Amylases/ultrastructure; Amylases/chemistry*; Enzyme Activation/drug effects; Enzyme Stability/drug effects; Gum Arabic/chemistry*; Hydrogen-Ion Concentration; Particle Size; Surface-Active Agents/pharmacology; Temperature; Thermodynamics; Oxidants/pharmacology; Cactaceae/enzymology; Cactaceae/chemistry*; Chitosan/chemistry*
  19. Mojiri A, Aziz HA, Zaman NQ, Aziz SQ, Zahed MA
    J Environ Manage, 2014 Jun 15;139:1-14.
    PMID: 24662109 DOI: 10.1016/j.jenvman.2014.02.017
    Sequencing batch reactor (SBR) is one of the various methods of biological treatments used for treating wastewater and landfill leachate. This study investigated the treatment of landfill leachate and domestic wastewater by adding a new adsorbent (powdered ZELIAC; PZ) to the SBR technique. ZELIAC consists of zeolite, activated carbon, lime stone, rice husk ash, and Portland cement. The response surface methodology and central composite design were used to elucidate the nature of the response surface in the experimental design and describe the optimum conditions of the independent variables, including aeration rate (L/min), contact time (h), and ratio of leachate to wastewater mixture (%; v/v), as well as their responses (dependent variables). Appropriate conditions of operating variables were also optimized to predict the best value of responses. To perform an adequate analysis of the aerobic process, four dependent parameters, namely, chemical oxygen demand (COD), color, ammonia-nitrogen (NH3-N), and phenols, were measured as responses. The results indicated that the PZ-SBR showed higher performance in removing certain pollutants compared with SBR. Given the optimal conditions of aeration rate (1.74 L/min), leachate to wastewater ratio (20%), and contact time (10.31 h) for the PZ-SBR, the removal efficiencies for color, NH3-N, COD, and phenols were 84.11%, 99.01%, 72.84%, and 61.32%, respectively.
    MeSH terms: Adsorption; Ammonia/analysis; Ammonia/chemistry; Calcium Carbonate/chemistry*; Carbon/chemistry*; Phenols/analysis; Phenols/chemistry; Powders; Oryza; Waste Disposal, Fluid/methods*; Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/chemistry*; Zeolites/chemistry*; Bioreactors*; Biological Oxygen Demand Analysis; Waste Water
  20. Latif MT, Dominick D, Ahamad F, Khan MF, Juneng L, Hamzah FM, et al.
    Sci Total Environ, 2014 Jun 1;482-483:336-48.
    PMID: 24662202 DOI: 10.1016/j.scitotenv.2014.02.132
    Rural background stations provide insight into seasonal variations in pollutant concentrations and allow for comparisons to be made with stations closer to anthropogenic emissions. In Malaysia, the designated background station is located in Jerantut, Pahang. A fifteen-year data set focusing on ten major air pollutants and four meteorological variables from this station were analysed. Diurnal, monthly and yearly pollutant concentrations were derived from hourly continuous monitoring data. Statistical methods employed included principal component regression (PCR) and sensitivity analysis. Although only one of the yearly concentrations of the pollutants studied exceeded national and World Health Organisation (WHO) guideline standards, namely PM10, seven of the pollutants (NO, NO2, NOx, O3, PM10, THC and CH4) showed a positive upward trend over the 15-year period. High concentrations of PM10 were recorded during severe haze episodes in this region. Whilst, monthly concentrations of most air pollutants, such as: PM10, O3, NOx, NO2, CO and NmHC were recorded at higher concentrations between June and September, during the southwest monsoon. Such results correspond with the mid-range transport of pollutants from more urbanised and industrial areas. Diurnal patterns, rationed between major air pollutants and sensitivity analysis, indicate the influence of local traffic emissions on air quality at the Jerantut background station. Although the pollutant concentrations have not shown a rapid increase, an alternative background station will need to be assigned within the next decade if development projects in the surrounding area are not halted.
    MeSH terms: Air Pollutants/analysis*; Air Pollution/statistics & numerical data*; Environmental Monitoring*; Malaysia; Seasons
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