Displaying publications 61 - 80 of 4447 in total

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  1. Determining weight-bearing tissue condition using peak reactive hyperemia response trend and ultrasonographic features: Implications for pressure ulcer prevention
    Yapp JH, Raja Ahmad RMK, Mahmud R, Mohtarrudin N, Mohamad Yusof L, Abdul Rahim E, et al.
    Wound Repair Regen, 2019 05;27(3):225-234.
    PMID: 30667138 DOI: 10.1111/wrr.12698
    Frequent repositioning is important to prevent pressure ulcer (PU) development, by relieving pressure and recovering damages on skin areas induced by repetitive loading. Although repositioning is the gold standard to prevent PU, there is currently no strategy for determining tissue condition under preventive approaches. In this study, the peak reactive hyperemia (RH) trends and ultrasonographic (US) features are compared with the tissue condition under histopathological examination to determine the potential use of these features in determining the tissue condition noninvasively. Twenty-one male Sprague-Dawley rats (seven per group), with body weight of 385-485 g, were categorized into three groups and subjected to different recovery times, each with three repetitive loading cycles at skin tissues above of right trochanter area. The first, second, and third groups were subjected to short (3 minutes), moderate (10 minutes), and prolonged (40 minutes) recovery, respectively, while applying fixed loading time and pressure (10 minutes and 50 mmHg, respectively), to provide different degree of recovery and tissue conditions (tissue damage and tissue recovery). Peak RH was measured in the three cycles to determine RH trend (increasing, decreasing, and inconsistent). All rat tissues were evaluated using ultrasound at pre- and post-experiment and rated by two raters to categorize the severity of tissue changes (no, mild, moderate, and severe). The tissue condition was also evaluated using histopathological examination to distinguish between normal and abnormal tissues. Most of the samples with increasing RH trend is related to abnormal tissue (71%); while inconsistent RH trends is more related to normal tissue (82%). There is no relationship between the tissue conditions evaluated under ultrasonographic and histopathological examination. Peak RH trend over repetitive loading may serve as a new feature for determining the tissue condition that leading to pressure ulcer.
    Matched MeSH terms: Regional Blood Flow/physiology*; Wound Healing/physiology*
  2. Coexistence of quorum-quenching and quorum-sensing in tropical marine Pseudomonas aeruginosa strain MW3A
    Wong CS, Yin WF, Choo YM, Sam CK, Koh CL, Chan KG
    World J Microbiol Biotechnol, 2012 Feb;28(2):453-61.
    PMID: 22806840 DOI: 10.1007/s11274-011-0836-x
    A chemically defined medium called KGm medium was used to isolate from a sample of sea water a bacterial strain, MW3A, capable of using N-3-oxohexanoyl-L: -homoserine lactone as the sole carbon source. MW3A was clustered closely to Pseudomonas aeruginosa by 16S ribosomal DNA sequence analysis. It degraded both N-acylhomoserine lactones (AHLs) with a 3-oxo group substitution and, less preferably, AHLs with unsubstituted groups at C3 position in the acyl side chain, as determined by Rapid Resolution Liquid Chromatography. Its quiP and pvdQ homologue gene sequences showed high similarities to those of known acylases. Spent supernatant of MW3A harvested at 8-h post inoculation was shown to contain long-chain AHLs when assayed with the biosensor Escherichia coli [pSB1075], and specifically N-dodecanoyl-L: -homoserine lactone and N-3-oxotetradecanoyl-L: -homoserine lactone by high resolution mass spectrometry. Hence, we report here a novel marine P. aeruginosa strain MW3A possessing both quorum-quenching and quorum-sensing properties.
    Matched MeSH terms: Quorum Sensing/physiology*
  3. Characterization of Streptomyces spp. isolated from the rhizosphere of oil palm and evaluation of their ability to suppress basal stem rot disease in oil palm seedlings when applied as powder formulations in a glasshouse trial
    Shariffah-Muzaimah SA, Idris AS, Madihah AZ, Dzolkhifli O, Kamaruzzaman S, Maizatul-Suriza M
    World J Microbiol Biotechnol, 2017 Dec 18;34(1):15.
    PMID: 29256103 DOI: 10.1007/s11274-017-2396-1
    Ganoderma boninense, the main causal agent of oil palm (Elaeis guineensis) basal stem rot (BSR), severely reduces oil palm yields around the world. To reduce reliance on fungicide applications to control BSR, we are investigating the efficacy of alternative control methods, such as the application of biological control agents. In this study, we used four Streptomyces-like actinomycetes (isolates AGA43, AGA48, AGA347 and AGA506) that had been isolated from the oil palm rhizosphere and screened for antagonism towards G. boninense in a previous study. The aim of this study was to characterize these four isolates and then to assess their ability to suppress BSR in oil palm seedlings when applied individually to the soil in a vermiculite powder formulation. Analysis of partial 16S rRNA gene sequences (512 bp) revealed that the isolates exhibited a very high level of sequence similarity (> 98%) with GenBank reference sequences. Isolates AGA347 and AGA506 showed 99% similarity with Streptomyces hygroscopicus subsp. hygroscopicus and Streptomyces ahygroscopicus, respectively. Isolates AGA43 and AGA48 also belonged to the Streptomyces genus. The most effective formulation, AGA347, reduced BSR in seedlings by 73.1%. Formulations using the known antifungal producer Streptomyces noursei, AGA043, AGA048 or AGA506 reduced BSR by 47.4, 30.1, 54.8 and 44.1%, respectively. This glasshouse trial indicates that these Streptomyces spp. show promise as potential biological control agents against Ganoderma in oil palm. Further investigations are needed to determine the mechanism of antagonism and to increase the shelf life of Streptomyces formulations.
    Matched MeSH terms: Streptomyces/physiology*
  4. Novel phage-based bio-processing of pathogenic Escherichia coli and its biofilms
    Jassim SA, Abdulamir AS, Abu Bakar F
    World J Microbiol Biotechnol, 2012 Jan;28(1):47-60.
    PMID: 22806779 DOI: 10.1007/s11274-011-0791-6
    To explore new approaches of phage-based bio-process of specifically pathogenic Escherichia coli bacteria in food products within a short period. One hundred and forty highly lytic designed coliphages were used. Escherichia coli naturally contaminated and Enterohemorrhagic Escherichia coli experimentally inoculated samples of lettuce, cabbage, meat, and egg were used. In addition, experimentally produced biofilms of E. coli were tested. A phage concentration of 10(3) PFU/ml was used for food products immersion, and for spraying of food products, 10(5) PFU/ml of a phage cocktail was used by applying a 20-s optimal dipping time in a phage cocktail. Food samples were cut into pieces and were either sprayed with or held in a bag immersed in lambda buffer containing a cocktail of 140 phages. Phage bio-processing was successful in eliminating completely E. coli in all processed samples after 48 h storage at 4°C. Partial elimination of E. coli was observed in earlier storage periods (7 and 18 h) at 24° and 37°C. Moreover, E. coli biofilms were reduced >3 log cycles upon using the current phage bio-processing. The use of a phage cocktail of 140 highly lytic designed phages proved highly effective in suppressing E. coli contaminating food products. Proper decontamination/prevention methods of pathogenic E. coli achieved in this study can replace the current chemically less effective decontamination methods.
    Matched MeSH terms: Coliphages/physiology*
  5. Fulltext Cholecystokinin hyperresponsiveness in functional dyspepsia
    Chua AS, Keeling PW
    World J Gastroenterol, 2006 May 07;12(17):2688-93.
    PMID: 16718754 DOI: 10.3748/wjg.v12.i17.2688
    Functional dyspepsia (FD) is a common disorder of yet uncertain etiology. Dyspeptic symptoms are usually meal related and suggest an association to gastrointestinal (GI) sensorimotor dysfunction. Cholecystokinin (CCK) is an established brain-gut peptide that plays an important regulatory role in gastrointestinal function. It inhibits gastric motility and emptying via a capsaicin sensitive vagal pathway. The effects on emptying are via its action on the proximal stomach and pylorus. CCK is also involved in the regulation of food intake. It is released in the gut in response to a meal and acts via vagal afferents to induce satiety. Furthermore CCK has also been shown to be involved in the pathogenesis of panic disorder, anxiety and pain. Other neurotransmitters such as serotonin and noradrenaline may be implicated with CCK in the coordination of GI activity. In addition, intravenous administration of CCK has been observed to reproduce the symptoms in FD and this effect can be blocked both by atropine and loxiglumide (CCK-A antagonist). It is possible that an altered response to CCK may be responsible for the commonly observed gastric sensorimotor dysfunction, which may then be associated with the genesis of dyspeptic symptoms.
    Matched MeSH terms: Cholecystokinin/physiology*; Gastrointestinal Motility/physiology; Norepinephrine/physiology; Receptors, Adrenergic/physiology; Receptors, Serotonin/physiology; Serotonin/physiology
  6. Fulltext Reassessment of functional dyspepsia: a topic review
    Chua AS
    World J Gastroenterol, 2006 May 07;12(17):2656-9.
    PMID: 16718748 DOI: 10.3748/wjg.v12.i17.2656
    Dyspepsia itself is not a diagnosis but stands for a constellation of symptoms referable to the upper gastrointestinal tract. It consists of a variable combination of symptoms including abdominal pain or discomfort, postprandial fullness, abdominal bloating, early satiety, nausea, vomiting, heartburn and acid regurgitation. Patients with heartburn and acid regurgitation invariably have gastroesophageal reflux disease and should be distinguished from those with dyspepsia. There is a substantial group of patients who do not have a definite structural or biochemical cause for their symptoms and are considered to be suffering from functional dyspepsia (FD). Gastrointestinal motor abnormalities, altered visceral sensation, dysfunctional central nervous system-enteral nervous system (CNS-ENS) integration and psychosocial factors have all being identified as important pathophysiological correlates. It can be considered as a biopsychosocial disorder with dysregulation of the brain-gut axis being central in origin of disease. FD can be categorized into different subgroups based on the predominant single symptom identified by the patient. This subgroup classification can assist us in deciding the appropriate symptomatic treatment for the patient.
    Matched MeSH terms: Gastrointestinal Motility/physiology
  7. Borg CR-10 scale as a new approach to monitoring office exercise training
    Shariat A, Cleland JA, Danaee M, Alizadeh R, Sangelaji B, Kargarfard M, et al.
    Work, 2018;60(4):549-554.
    PMID: 30103362 DOI: 10.3233/WOR-182762
    BACKGROUND: There are many potential training exercises for office workers in an attempt to prevent musculoskeletal disorders. However, to date a suitable tool to monitor the perceived exertion of those exercises does not exist.

    OBJECTIVE: The primary objective of this study was to examine the validity and reliability of the Borg CR-10 scale to monitor the perceived exertion of office exercise training.

    METHODS: The study involved 105 staff members employed in a government office with an age range from 25 to 50 years. The Borg CR-10 scale was self-administered two times, with an interval of two weeks in order to evaluate the accuracy of the original findings with a retest. Face validity and content validity were also examined.

    RESULTS: Reliability was found to be high for the Borg CR-10 scale (0.898). Additionally a high correlation between the Borg CR-10 scale and Visual Analog Scale (VAS) was identified (rs = 0.754, P 

    Matched MeSH terms: Heart Rate/physiology; Oxygen Consumption/physiology
  8. Associations between prenatal nicotine exposure, oxidative stress, and postpartum visceral fat
    Loy SL, Jan Mohamed HJ
    Women Health, 2014;54(2):145-60.
    PMID: 24329183 DOI: 10.1080/03630242.2013.870632
    This study aimed to examine the associations among prenatal nicotine exposure, oxidative stress, and postpartum visceral fat among women exposed to secondhand smoke (SHS). The study was conducted in Kelantan, Malaysia, from April 2010 to December 2012. Blood samples were collected in the second and third trimesters from 135 healthy pregnant women who were followed-up at delivery, 2 months, 6 months and 12 months postpartum. Maternal hair nicotine and oxidative stress markers during pregnancy were measured. Visceral fat was assessed by bioelectrical impedance. Multiple linear regression analysis revealed that maternal hair nicotine concentration was associated with increased DNA damage (tail moment: β=0.580, p=0.001) and decreased glutathione peroxidase (β=-12.100; p=0.009) in the second trimester of pregnancy. Increased DNA damage, protein oxidation and total antioxidant capacity in the second trimester were associated with 2, 6, and 12 months postpartum visceral fat. No direct association was found between prenatal hair nicotine level and postpartum visceral fat; however, these results suggest that any relation of SHS to visceral adiposity may be indirect, mediated via enhanced oxidative stress.
    Matched MeSH terms: DNA Damage/physiology; Pregnancy/physiology
  9. Midlife crisis perceptions, experiences, help-seeking, and needs among multi-ethnic malaysian women
    Wong LP, Awang H, Jani R
    Women Health, 2012;52(8):804-19.
    PMID: 23127220 DOI: 10.1080/03630242.2012.729557
    In the present study, researchers explored attitudes toward midlife crises, experience with midlife crises, help-seeking, and needs among multi-ethnic Malaysian women. A total of 14 focus group discussions were conducted with 89 Malaysian women of different ages and socioeconomic backgrounds. Women expressed concern over physical aging and decline in their physical functional health. Having a midlife crisis was frequently reported. Issues that were frequently reported to trigger a midlife crisis, such as empty nest syndrome, impact of aging on sexual and reproductive function, extended parenthood, caring for aging or ill parents, and career challenges were noted by the study participants (listed here in order of most to least frequently reporting of these themes across the group discussions). Overall, these issues were associated with attitudes about aging. A comparatively less open attitude toward sexual attitudes and help-seeking for sexual problems were found among the Malay and Indian women. This may imply that intervention to increase positive attitudes concerning both sexuality and help-seeking intentions should be culturally specific. The use of religious coping for comfort and consolation was frequently reported; therefore, those providing midlife crisis prevention and intervention programs should consider involving faith-based interventions in the Malaysian setting.
    Matched MeSH terms: Aging/physiology
  10. Reproductive factors influencing bone mineral density in postmenopausal women
    Mohammadi F, Amirzadeh Iranagh J, Motalebi SA, Hamid TA
    Women Health, 2019 02;59(2):145-154.
    PMID: 29400628 DOI: 10.1080/03630242.2018.1434592
    This study examined the relationship between reproductive characteristics and bone mineral density (BMD) in postmenopausal women who had been referred to the menopause clinics of the National Population and Family Development Board and of the Hospital Kuala Lumpur from July 2011 to January 2012. The participants of this study were 201 postmenopausal Malaysian women aged 45-71 years. Some socio-demographic, lifestyle, and reproductive factors were recorded. Calcaneal BMD was measured by quantitative ultra-sonography. Correlations of reproductive factors with BMD were assessed by Pearson's correlation test and multiple regression analysis. Age at menopause was not significantly correlated with BMD, while the years after menopause, age at the first menstrual period, number of pregnancies, and total lactation periods were inversely correlated with it. Among reproductive factors, only the association between lactation duration and BMD remained significant after adjusting for age, body mass index, activity, and calcium intake. The results indicated that except for prolonged total time of lactation, other reproductive factors were not significantly associated with BMD in postmenopausal women.
    Matched MeSH terms: Lactation/physiology; Menstruation/physiology; Bone Density/physiology*; Postmenopause/physiology*
  11. Developments in the functions of autobiographical memory: An advanced review
    Sow F, Dijkstra K, Janssen SMJ
    Wiley Interdiscip Rev Cogn Sci, 2023;14(3):e1625.
    PMID: 36165349 DOI: 10.1002/wcs.1625
    In this advanced review, the development of the three most commonly used functions of autobiographical memory-directing behavior, social bonding, and self-continuity-and the support they have received in the literature are discussed. Support for this tripartite model often comes from correlational studies that use self-report measures, but participants in these studies may not be aware that they retrieved autobiographical memories to fulfill certain goals. Not only is more experimental research needed to confirm the findings from correlational studies, this kind of research needs to be more rigorous. Moreover, the functions of the tripartite model may not be the only autobiographical memory functions that can be distinguished. For example, there is already substantial support for the emotion-regulation function. Although memories can be used for multiple functions, patterns between aspects of the event (e.g., emotional valence) or memory (e.g., specificity) and their functionality have been found. In addition, individual differences (e.g., cultural background, depression symptoms) and situational factors (e.g., is there a goal that needs to be fulfilled) may regulate the functional deployment of autobiographical memories. Future research should therefore extend its focus on the conditions in which these functions can be observed. This article is categorized under: Psychology > Memory.
    Matched MeSH terms: Emotions/physiology; Mental Recall/physiology
  12. Activity of Eurycoma longifolia root extract against Plasmodium falciparum in vitro
    Wernsdorfer WH, Ismail S, Chan KL, Congpuong K, Wernsdorfer G
    Wien Klin Wochenschr, 2009 Oct;121 Suppl 3:23-6.
    PMID: 19915812 DOI: 10.1007/s00508-009-1230-7
    The habitats of Eurycoma longifolia Jack, a slender tree, are jungles in Malaysia and Indonesia. It belongs to the family Simaroubaceae and is a source of quassinoids with anabolic, antimalarial and cytostatic activity. In this study, conducted during 2008 in Mae Sot, Thailand, a standardized extract of E. longifolia containing three major quassinoids, eurycomanone (1), 13,21-dihydroeurycomanone (2) and 13alpha(21)-epoxyeurycomanone (3) was evaluated for antiplasmodial activity against Plasmodium falciparum and its activity has been compared with that of artemisinin, using 38 fresh parasite isolates and assessment of inhibition of schizont maturation. The IC(50), IC(90) and IC(99) values for artemisinin were 4.30, 45.48 and 310.97 microg/l, and those for the root extract from E. longifolia 14.72, 139.65 and 874.15 microg/l respectively. The GMCOC for artemisinin was 337.81 mug/l, and for the plant extract it was 807.41 microg/l. The log-concentration probit regressions were parallel. The inhibitory activity of the E. longifolia extract was higher than that expected from the three quassinoids isolated from the plant, suggesting synergism between the quassinoids or the presence of other unidentified compounds.
    Matched MeSH terms: Plasmodium falciparum/physiology*
  13. THE ROLE OF BIOMARKER MACROPHAGE MIGRATION INHIBITORY FACTOR IN CARDIAC REMODELING PREDICTION IN PATIENTS WITH ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION
    Vyshnevska IR, Storozhenko T, Kopytsya MP, Bila NV, Kis A, Kaaki M
    Wiad Lek, 2023;76(5 pt 1):911-919.
    PMID: 37326070 DOI: 10.36740/WLek202305104
    OBJECTIVE: The aim: To estimate the role of macrophage migration inhibitory factor and soluble ST2 in predicting the left ventricle remodeling six months after ST-segment elevation myocardial infarction.

    PATIENTS AND METHODS: Materials and methods: The study involved 134 ST-segment elevation myocardial infarction patients. Occurrence of post-percutaneous coronary (PCI) intervention epicardial blood flow of TIMI <3 or myocardial blush grade 0-1 along with ST resolution <70% within 2 hours after PCI was qualified as the no-reflow condition. Left ventricle remodeling was defined after 6-months as an increase in left ventricle end-diastolic volume and/or end-systolic volume by more than 10%.

    RESULTS: Results: A logistic regression formula was evaluated. Included biomarkers were macrophage migration inhibitory factor and sST2, left ventricle ejection fraction: Y=exp(-39.06+0.82EF+0.096ST2+0.0028MIF) / (1+exp(-39.06+0.82EF+0.096ST2+0.0028MIF)). The estimated range is from 0 to 1 point. Less than 0.5 determines an adverse outcome, and more than 0.5 is a good prognosis. This equation, with sensitivity of 77 % and specificity of 85%, could predict the development of adverse left ventricle remodeling six months after a coronary event (AUC=0.864, CI 0.673 to 0.966, p<0.05).

    CONCLUSION: Conclusions: A combination of biomarkers gives a significant predicting result in the formation of adverse left ventricular remodeling after ST-segment elevation myocardial infarction.

    Matched MeSH terms: Ventricular Remodeling/physiology
  14. Organic matter and nitrogen removal at planted wetlands treating domestic septage with varying operational strategies
    Jong VS, Tang FE
    Water Sci Technol, 2014;70(2):352-60.
    PMID: 25051484 DOI: 10.2166/wst.2014.237
    A two-staged engineered wetland-based system was designed and constructed to treat raw domestic septage. Hydraulic loading rates (HLRs) of 8.75 and 17.5 cm/d were studied with four and eight daily dosings at the second stage of the system to investigate the influence of the regimes on septage treatment. Removal of organic matter (OM) was found to be HLR dependent, where the results indicated that the increase of HLR from 8.75 to 17.5 cm/d impaired the overall level of treatment in the wetland units. Effluent of wetland fed at HLR 17.5 cm/d presented significantly lower oxygen reduction potential and dissolved oxygen values than wetland fed at 8.75 cm/d, indicative of the occurrence of less aerobic and reductive conditions in the bed. The reoxygenation capability of the wetland units was found to be heavily affected by the dosing frequency especially under high hydraulic load (17.5 cm/d). NH3-N degradation was found to decrease with statistical importance when the wetland was flushed two times more frequently with smaller batches of influent. The number of hydraulic load fractionings did not seem to affect the level of treatments of OM and ammonia for both the wetlands fed under the lower HLR of 8.75 cm/d. Prediction of hydraulic limits and management of the feeding strategies are important in the vertical type of engineered wetlands to guarantee the treatment performance and minimize the chances of filter clogging.
    Matched MeSH terms: Poaceae/physiology*
  15. Pleurotus ostreatus spent mushroom compost as green biosorbent for nickel (II) biosorption
    Tay CC, Liew HH, Redzwan G, Yong SK, Surif S, Abdul-Talib S
    Water Sci Technol, 2011;64(12):2425-32.
    PMID: 22170837 DOI: 10.2166/wst.2011.805
    The potential of Pleurotus ostreatus spent mushroom compost (PSMC) as a green biosorbent for nickel (II) biosorption was investigated in this study. A novel approach of using the half-saturation concentration of biosorbent to rapidly determine the uptake, kinetics and mechanism of biosorption was employed together with cost per unit uptake analysis to determine the potential of this biosorbent. Fifty per cent nickel (II) biosorption was obtained at a half-saturation constant of 0.7 g biosorbent concentration, initial pH in the range of 4-8, 10 min contact time, 50 mL 50 mg/L nickel (II) initial concentration. The experimental data were well fitted with the Langmuir isotherm model and the maximum nickel (II) biosorption was 3.04 mg/g. The results corresponded well to a second pseudo order kinetic model with the coefficient of determination value of 0.9999. Based on FTIR analysis, the general alkyl, hydroxyl or amino, aliphatic alcohol and carbonyl functional groups of biosorbent were involved in the biosorption process. Therefore, biosorption of nickel (II) must involve several mechanisms simultaneously such as physical adsorption, chemisorption and ion exchange. Cost comparison for PSMC with Amberlite IRC-86 ion exchange resin indicates that the biosorbent has the potential to be developed into a cost effective and environmentally friendly treatment system.
    Matched MeSH terms: Pleurotus/physiology*
  16. Parametric and adsorption kinetic studies of methylene blue removal from simulated textile water using durian (Durio zibethinus murray) skin
    Anisuzzaman SM, Joseph CG, Krishnaiah D, Bono A, Ooi LC
    Water Sci Technol, 2015;72(6):896-907.
    PMID: 26360749 DOI: 10.2166/wst.2015.247
    In this study, durian (Durio zibethinus Murray) skin was examined for its ability to remove methylene blue (MB) dye from simulated textile wastewater. Adsorption equilibrium and kinetics of MB removal from aqueous solutions at different parametric conditions such as different initial concentrations (2-10 mg/L), biosorbent dosages (0.3-0.7 g) and pH solution (4-9) onto durian skin were studied using batch adsorption. The amount of MB adsorbed increased from 3.45 to 17.31 mg/g with the increase in initial concentration of MB dye; whereas biosorbent dosage increased from 1.08 to 2.47 mg/g. Maximum dye adsorption capacity of the durian skin was found to increase from 3.78 to 6.40 mg/g, with increasing solution pH. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich isotherm models. The sorption equilibrium was best described by the Freundlich isotherm model with maximum adsorption capacity of 7.23 mg/g and this was due to the heterogeneous nature of the durian skin surface. Kinetic studies indicated that the sorption of MB dye tended to follow the pseudo second-order kinetic model with promising correlation of 0.9836 < R(2) < 0.9918.
    Matched MeSH terms: Bombacaceae/physiology*
  17. Evaluation of solid-state bioconversion of domestic wastewater sludge as a promising environmental-friendly disposal technique
    Hossain Molla A, Fakhru'l-Razi A, Zahangir Alam M
    Water Res, 2004 Nov;38(19):4143-52.
    PMID: 15491662
    Natural and environmental-friendly disposal of wastewater sludge is a great concern. Recently, biological treatment has played prominent roles in bioremediation of complex hydrocarbon- rich contaminants. Composting is quite an old biological-based process that is being practiced but it could not create a great impact in the minds of concerned researchers. The present study was conducted to evaluate the feasibility of the solid-state bioconversion (SSB) processes in the biodegradation of wastewater sludge by exploiting this promising technique to rejuvenate the conventional process. The Indah Water Konsortium (IWK) domestic wastewater treatment plant (DWTP) sludge was considered for evaluation of SSB by monitoring the microbial growth and its subsequent roles in biodegradation under two conditions: (i) flask (F) and (ii) composting bin (CB) cultures. Sterile and semi-sterile environments were allowed in the F and the CB, respectively, using two mixed fungal cultures, Trichoderma harzianum with Phanerochaete chrysosporium 2094 (T/P) and T. harzianum with Mucor hiemalis (T/M) and two bulking materials, sawdust (SD) and rice straw (RS). The significant growth and multiplication of both the mixed fungal cultures were reflected in soluble protein, glucosamine and color intensity measurement of the water extract. The color intensity and pH of the water extract significantly increased and supported the higher growth of microbes and bioconversion. The most encouraging results of microbial growth and subsequent bioconversion were exhibited in the RS than the SD. A comparatively higher decrease of organic matter (OM) % and C/N ratio were attained in the CB than the F, which implied a higher bioconversion. But the measurement of soluble protein, glucosamine and color intensity exhibited higher values in the F than the CB. The final pH drop was higher in the CB than the F, which implied that a higher nitrification occurred in the CB associated with a higher release of H+ ions. Both the mixed cultures performed almost equal roles in all cases except the changes in moisture content.
    Matched MeSH terms: Trichoderma/physiology*; Phanerochaete/physiology*
  18. Enhanced settleability and dewaterability of fungal treated domestic wastewater sludge by liquid state bioconversion process
    Alam MZ, Fakhru'l-Razi A
    Water Res, 2003 Mar;37(5):1118-24.
    PMID: 12553987
    A study was conducted to evaluate the settleability and dewaterability of fungal treated and untreated sludge using liquid state bioconversion process. The fungal mixed culture of Aspergillus niger and Penicillium corylophilum was used for fungal pretreatment of wastewater sludge. The fungal strains immobilized/entrapped on sludge particles with the formation of pellets and enhanced the separation process. The results presented in this study showed that the sludge particles (pellets) size of 2-5mm of diameter were formed with the microbial treatment of sludge after 2 days of fermentation that contained maximum 33.7% of total particles with 3-3.5mm of diameter. The settling rate (measured as total suspended solids (TSS) concentration, 130 mg/l) was faster in treated sludge than untreated sludge (TSS concentration, 440 mg/l) after 1 min of settling time. In 1 min of settling operation, 86.45% of TSS was settled in treated sludge while 4.35% of TSS settled in raw sludge. Lower turbidity was observed in treated sludge as compared to untreated sludge. The results to specific resistance to filtration (SRF) revealed that the fungal inoculum had significant potentiality to reduce SRF by 99.8% and 98.7% for 1% w/w and 4% w/w of TSS sludge, respectively. The optimum fermentation period recorded was 3 days for 1% w/w sludge and 6 days for 4% w/w sludge, respectively, for dewaterability test.
    Matched MeSH terms: Aspergillus niger/physiology*; Penicillium/physiology*
  19. Effect on heavy metals concentration from vermiconversion of agro-waste mixed with landfill leachate
    Azizi AB, Choy MY, Noor ZM, Noorlidah A
    Waste Manag, 2015 Apr;38:431-5.
    PMID: 25670166 DOI: 10.1016/j.wasman.2015.01.020
    Spent Pleurotus sajor-caju compost mixed with livestock excreta, i.e. cow dung or goat manure, was contaminated with landfill leachate and vermiremediated in 75 days. Results showed an extreme decrease of heavy metals, i.e. Cd, Cr and Pb up to 99.81% removal as effect of vermiconversion process employing epigeic earthworms i.e. Lumbricus rubellus. In addition, there were increments of Cu and Zn from 15.01% to 85.63%, which was expected as non-accumulative in L. rubellus and secreted out as contained in vermicompost. This phenomenon is due to dual effects of heavy metal excretion period and mineralisation. Nonetheless, the increments were 50-fold below the limit set by EU and USA compost limits and the Malaysian Recommended Site Screening Levels for Contaminated Land (SSLs). Moreover, the vermicompost C:N ratio range is 20.65-22.93 and it can be an advantageous tool to revitalise insalubrious soil by acting as soil stabiliser or conditioner.
    Matched MeSH terms: Oligochaeta/physiology*
  20. The performance of Electro-Fenton oxidation in the removal of coliform bacteria from landfill leachate
    Aziz HA, Othman OM, Abu Amr SS
    Waste Manag, 2013 Feb;33(2):396-400.
    PMID: 23158874 DOI: 10.1016/j.wasman.2012.10.016
    Leachate pollution is one of the main problems in landfilling. Researchers have yet to find an effective solution to this problem. The technology that can be used may differ based on the type of leachate produced. Coliform bacteria were recently reported as one of the most problematic pollutants in semi-aerobic (stabilized) leachate. In the present study, the performance of the Electro-Fenton process in removing coliform from leachate was investigated. The study focused on two types of leachate: Palau Borung landfill leachate with low Coliform content (200 MPN/100 m/L) and Ampang Jajar landfill leachate with high coliform content (>24 × 10(4)MPN/100 m/L). Optimal conditions for the Electro-Fenton treatment process were applied on both types of leachate. Then, the coliform was examined before and after treatment using the Most Probable Number (MPN) technique. Accordingly, 100% removal of coliform was obtained at low initial coliform content, whereas 99.9% removal was obtained at high initial coliform content. The study revealed that Electro-Fenton is an efficient process in removing high concentrations of pathogenic microorganisms from stabilized leachate.
    Matched MeSH terms: Enterobacteriaceae/physiology*
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