Browse publications by year: 2016

  1. Non-protein coding RNA-based genosensor with quantum dots as electrochemical labels for attomolar detection of multiple pathogens
    Vijian D, Chinni SV, Yin LS, Lertanantawong B, Surareungchai W
    Biosens Bioelectron, 2016 Mar 15;77:805-11.
    PMID: 26513287 DOI: 10.1016/j.bios.2015.10.057
    The ability of a diagnostic test to detect multiple pathogens simultaneously is useful to obtain meaningful information for clinical treatment and preventive measures. We report a highly sensitive and specific electrochemical biosensor assay for simultaneous detection of three gene targets using quantum dots (QDs). The targets are novel non-protein coding RNA (npcRNA) sequences of Vibrio cholerae, Salmonella sp. and Shigella sp., which cause diarrheal diseases. QDs (PbS, CdS, ZnS) were synthesized and functionalized with DNA probes that were specific to each pathogen. Electrochemical detection of QDs was performed using square wave anodic stripping voltammetry (SWASV). The QDs gave distinct peaks at 0.5 V (PbS), 0.75 V (CdS) and 1.1 V (ZnS). There was no interference in signal response when all three QDs were mixed and detected simultaneously. The detection limits of single and multiplex assays with linear targets and PCR products were in the attomolar ranges. The high assay sensitivity, in combination with specific npcRNA sequences as novel diagnostic targets, makes it a viable tool for detecting pathogens from food, environment and clinical samples.
  2. Model-aided atpE gene knockout strategy in Escherichia coli for enhanced succinic acid production from glycerol
    Mienda BS, Shamsir MS, Md Illias R
    J Biomol Struct Dyn, 2016 Aug;34(8):1705-16.
    PMID: 26513379 DOI: 10.1080/07391102.2015.1090341
    Succinic acid is an important platform chemical with a variety of applications. Model-guided metabolic engineering strategies in Escherichia coli for strain improvement to increase succinic acid production using glucose and glycerol remain largely unexplored. Herein, we report what are, to our knowledge, the first metabolic knockout of the atpE gene to have increased succinic acid production using both glucose and alternative glycerol carbon sources in E. coli. Guided by a genome-scale metabolic model, we engineered the E. coli host to enhance anaerobic production of succinic acid by deleting the atpE gene, thereby generating additional reducing equivalents by blocking H(+) conduction across the mutant cell membrane. This strategy produced 1.58 and .49 g l(-1) of succinic acid from glycerol and glucose substrate, respectively. This work further elucidates a model-guided and/or system-based metabolic engineering, involving only a single-gene deletion strategy for enhanced succinic acid production in E. coli.
    MeSH terms: Escherichia coli/genetics*; Escherichia coli/metabolism*; Fermentation; Glucose/metabolism; Glycerol/metabolism; Models, Biological*; Mutation; Succinic Acid/metabolism*; Bacterial Proton-Translocating ATPases/genetics*; Bacterial Proton-Translocating ATPases/metabolism*; Escherichia coli Proteins/genetics*; Escherichia coli Proteins/metabolism*; Metabolic Networks and Pathways; Gene Knockout Techniques*
  3. Should Partial Hydrolysates Be Used as Starter Infant Formula? A Working Group Consensus
    Vandenplas Y, Alarcon P, Fleischer D, Hernell O, Kolacek S, Laignelet H, et al.
    J Pediatr Gastroenterol Nutr, 2016 Jan;62(1):22-35.
    PMID: 26513620 DOI: 10.1097/MPG.0000000000001014
    Partially hydrolyzed formulas (pHFs) are increasingly used worldwide, both in the prevention of atopic disease in at-risk infants and in the therapeutic management of infants with functional gastrointestinal manifestations. Because prevention is always preferable to treatment, we reviewed the literature aiming to find an answer for the question whether pHF may be recommended for feeding all infants if breast-feeding is not possible. PubMed and Cochrane databases were searched up to December 2014. In addition, to search for data that remained undetected by the searches, we approached authors of relevant articles and major producers of pHFs asking for unpublished data. Because few data were found, nonrandomized, controlled trials and trials in preterm infants were included as well. Overall, only limited data could be found on the efficacy and safety of pHF in healthy term infants. Available data do not indicate that pHFs are potentially harmful for healthy, term infants. With respect to long-term outcomes, particularly referring to immune, metabolic and hormonal effects, data are, however, nonexistent. From a regulatory point of view, pHFs meet the nutrient requirements to be considered as standard formula for term healthy infants. Cost, which is different from country to country, should be considered in the decision-making process. Based on limited available data, the use of pHF in healthy infants is safe with regard to growth. The lack of data, in particular for metabolic consequences and long-term outcomes, is, however, the basis for our recommendation that health authorities should develop and support long-term follow-up studies. Efficacy and long-term safety data are required before a recommendation of this type of formula for all infants can be made.
    MeSH terms: Breast Feeding; Breast Neoplasms; Female; Follow-Up Studies; Food, Formulated; Humans; Infant; Infant, Newborn; Infant, Premature; Nutritional Requirements; Reference Standards; PubMed
  4. Interpretation of mushroom as a common therapeutic agent for Alzheimer's disease and cardiovascular diseases
    Rahman MA, Abdullah N, Aminudin N
    Crit Rev Biotechnol, 2016 Dec;36(6):1131-1142.
    PMID: 26514091
    Alzheimer's disease (AD) and cardiovascular diseases (CVD) share common etiology and preventive strategies. As the population of old-aged people is increasing worldwide, AD complications tend to afflict global healthcare budget and economy heavily. CVD is the prime cause of global mortality and remains a grave threat to both the developed and the developing nations. Mushroom bio-components may be promising in controlling both diseases. Based mainly on in vitro, ex vivo, cell line and animal studies, this review interprets the polypharmaceutic role of mushrooms treating AD and CVD.
    MeSH terms: Agaricales*; Alzheimer Disease/therapy*; Animals; Cardiotonic Agents/therapeutic use*; Cardiovascular Diseases/therapy*; Humans; Neuroprotective Agents/therapeutic use*
  5. Physico-chemical properties of Moringa oleifera seed oil enzymatically interesterified with palm stearin and palm kernel oil and its potential application in food
    Dollah S, Abdulkarim SM, Ahmad SH, Khoramnia A, Mohd Ghazali H
    J Sci Food Agric, 2016 Aug;96(10):3321-33.
    PMID: 26514240 DOI: 10.1002/jsfa.7510
    High oleic acid Moringa oleifera seed oil (MoO) has been rarely applied in food products due to the low melting point and lack of plasticity. Enzymatic interesterification (EIE) of MoO with palm stearin (PS) and palm kernel oil (PKO) could yield harder fat stocks that may impart desirable nutritional and physical properties.
    MeSH terms: Plant Oils; Seeds; Triglycerides; Oleic Acid; Moringa oleifera
  6. Brain functional connectivity patterns for emotional state classification in Parkinson's disease patients without dementia
    Yuvaraj R, Murugappan M, Acharya UR, Adeli H, Ibrahim NM, Mesquita E
    Behav Brain Res, 2016 Feb 1;298(Pt B):248-60.
    PMID: 26515932 DOI: 10.1016/j.bbr.2015.10.036
    Successful emotional communication is crucial for social interactions and social relationships. Parkinson's Disease (PD) patients have shown deficits in emotional recognition abilities although the research findings are inconclusive. This paper presents an investigation of six emotions (happiness, sadness, fear, anger, surprise, and disgust) of twenty non-demented (Mini-Mental State Examination score >24) PD patients and twenty Healthy Controls (HCs) using Electroencephalogram (EEG)-based Brain Functional Connectivity (BFC) patterns. The functional connectivity index feature in EEG signals is computed using three different methods: Correlation (COR), Coherence (COH), and Phase Synchronization Index (PSI). Further, a new functional connectivity index feature is proposed using bispectral analysis. The experimental results indicate that the BFC change is significantly different among emotional states of PD patients compared with HC. Also, the emotional connectivity pattern classified using Support Vector Machine (SVM) classifier yielded the highest accuracy for the new bispectral functional connectivity index. The PD patients showed emotional impairments as demonstrated by a poor classification performance. This finding suggests that decrease in the functional connectivity indices during emotional stimulation in PD, indicating functional disconnections between cortical areas.
    MeSH terms: Anger; Brain; Electroencephalography; Emotions; Fear; Happiness; Humans; Interpersonal Relations; Parkinson Disease; Support Vector Machine
  7. Simulium (Gomphostilbia) merapiense sp. nov. (Diptera: Simuliidae) from Java, Indonesia
    Takaoka H, Sofian-Azirun M, Ya'cob Z, Chen CD, Low VL, Zaid A
    J Med Entomol, 2016 Jan;53(1):76-82.
    PMID: 26516192 DOI: 10.1093/jme/tjv154
    Simulium (Gomphostilbia) merapiense sp. nov. is described based on females, males, pupae, and mature larvae from Yagyakarta, Java, Indonesia. This new species is placed in the Simulium epistum species-group, and is characterized by the pupal gill with eight short filaments all arising at the same level from a short stalk, somewhat enlarged basal fenestra, entirely bare pupal head and thoracic integument, and small and short larval postgenal cleft. These characters rarely are found in the subgenus. Taxonomic notes are given to separate this new species from related species of the S. epistum species-group.
    MeSH terms: Animals; Female; Indonesia; Larva/anatomy & histology; Male; Terminology as Topic; Pupa/anatomy & histology; Simuliidae/anatomy & histology*; Simuliidae/classification; Biodiversity
  8. In vitro anticancer properties and biological evaluation of novel natural alkaloid jerantinine B
    Qazzaz ME, Raja VJ, Lim KH, Kam TS, Lee JB, Gershkovich P, et al.
    Cancer Lett, 2016 Jan 28;370(2):185-97.
    PMID: 26515390 DOI: 10.1016/j.canlet.2015.10.013
    Natural products play a pivotal role in medicine especially in the cancer arena. Many drugs that are currently used in cancer chemotherapy originated from or were inspired by nature. Jerantinine B (JB) is one of seven novel Aspidosperma indole alkaloids isolated from the leaf extract of Tabernaemontana corymbosa. Preliminary antiproliferative assays revealed that JB and JB acetate significantly inhibited growth and colony formation, accompanied by time- and dose-dependent apoptosis induction in human cancer cell lines. JB significantly arrested cells at the G2/M cell cycle phase, potently inhibiting tubulin polymerisation. Polo-like kinase 1 (PLK1; an early trigger for the G2/M transition) was also dose-dependently inhibited by JB (IC50 1.5 µM). Furthermore, JB provoked significant increases in reactive oxygen species (ROS). Annexin V+ cell populations, dose-dependent accumulation of cleaved-PARP and caspase 3/7 activation, and reduced Bcl-2 and Mcl-1 expression confirm apoptosis induction. Preclinical in silico biopharmaceutical assessment of JB calculated rapid absorption and bioavailability >70%. Doses of 8-16 mg/kg JB were predicted to maintain unbound plasma concentrations >GI50 values in mice during efficacy studies. These findings advocate continued development of JB as a potential chemotherapeutic agent.
    MeSH terms: Antineoplastic Agents, Phytogenic/pharmacology*; Cytoskeleton/drug effects; Humans; Proto-Oncogene Proteins/antagonists & inhibitors; Vincristine/pharmacology; Apoptosis/drug effects; Protein-Serine-Threonine Kinases/antagonists & inhibitors; Reactive Oxygen Species/metabolism; Cell Cycle Proteins/antagonists & inhibitors; Indole Alkaloids/pharmacology*; Cell Line, Tumor; Cell Cycle Checkpoints/drug effects
  9. Nepenthes ampullaria (Nepenthaceae) Pitchers Are Unattractive to Gravid Aedes aegypti and Aedes albopictus (Diptera: Culicidae)
    Chou LY, Dykes GA, Wilson RF, Clarke CM
    Environ Entomol, 2016 Feb;45(1):201-6.
    PMID: 26518035 DOI: 10.1093/ee/nvv164
    Nepenthes pitcher plants are colonized by a variety of specialized arthropods. As Aedes mosquitoes are container breeders, Nepenthes pitchers are a potential candidate oviposition site for vector species, such as Aedes aegypti (L.) and Aedes albopictus (Skuse). However, Aedes spp. are not commonly encountered in Nepenthes pitchers, and the environment inside the pitchers of some species is lethal to them. One exception is Nepenthes ampullaria Jack, whose pitchers are known to be colonized by Ae. albopictus on very rare occasions. Given that Ae. albopictus larvae can survive in N. ampullaria pitcher fluids, we sought to determine why pitcher colonization is rare, testing the hypothesis that gravid Aedes mosquitoes are deterred from ovipositing into container habitats that have similar characteristics to N. ampullaria pitchers. Using plastic ovitraps of different sizes, colors, and with different types of fluids (based on the characteristics of N. ampullaria pitchers), we compared oviposition rates by Aedes mosquitoes in urban and rural areas within the geographical range of N. ampullaria near Kuala Lumpur, Malaysia. Ovitraps that were black and large (>250-ml capacity) accumulated significantly more eggs than ovitraps that were smaller, or green in color. In terms of size and color, small, green ovitraps are analogous to N. ampullaria pitchers, indicating that these pitchers are not particularly attractive to gravid Ae. albopictus. Although Aedes spp. are capable of colonizing N. ampullaria pitchers, the pitchers are relatively unattractive to gravid females and do not represent a significant habitat for larvae of dengue vectors at present.
    MeSH terms: Aedes; Animals; Arthropods; Color; Dengue; Disease Vectors; Environment; Female; Larva; Malaysia; Oviposition; Plastics; Ecosystem
  10. Expression and purification of the matrix protein of Nipah virus in baculovirus insect cell system
    Masoomi Dezfooli S, Tan WS, Tey BT, Ooi CW, Hussain SA
    Biotechnol Prog, 2016 Jan-Feb;32(1):171-7.
    PMID: 26519022 DOI: 10.1002/btpr.2192
    Nipah virus (NiV) causes fatal respiratory illness and encephalitis in humans and animals. The matrix (M) protein of NiV plays an important role in the viral assembly and budding process. Thus, an access to the NiV M protein is vital to the design of viral antigens as diagnostic reagents. In this study, recombinant DNA technology was successfully adopted in the cloning and expression of NiV M protein. A recombinant expression cassette (baculovirus expression vector) was used to encode an N-terminally His-tagged NiV M protein in insect cells. A time-course study demonstrated that the highest yield of recombinant M protein (400-500 μg) was expressed from 107 infected cells 3 days after infection. A single-step purification method based on metal ion affinity chromatography was established to purify the NiV M protein, which successfully yielded a purity level of 95.67% and a purification factor of 3.39. The Western blotting and enzyme-linked immunosorbent assay (ELISA) showed that the purified recombinant M protein (48 kDa) was antigenic and reacted strongly with the serum of a NiV infected pig.
    MeSH terms: Animals; Antigens, Viral; Chromatography, Affinity; Cloning, Molecular; DNA, Recombinant; Encephalitis; Enzyme-Linked Immunosorbent Assay; Humans; Metals; Recombinant Proteins; Swine; Blotting, Western; Baculoviridae; Virus Assembly; Nipah Virus
  11. A model of chlorpyrifos distribution and its biochemical effects on the liver and kidneys of rats
    Tanvir EM, Afroz R, Chowdhury M, Gan SH, Karim N, Islam MN, et al.
    Hum Exp Toxicol, 2016 Sep;35(9):991-1004.
    PMID: 26519480 DOI: 10.1177/0960327115614384
    This study investigated the main target sites of chlorpyrifos (CPF), its effect on biochemical indices, and the pathological changes observed in rat liver and kidney function using gas chromatography/mass spectrometry. Adult female Wistar rats (n = 12) were randomly assigned into two groups (one control and one test group; n = 6 each). The test group received CPF via oral gavage for 21 days at 5 mg/kg daily. The distribution of CPF was determined in various organs (liver, brain, heart, lung, kidney, ovary, adipose tissue, and skeletal muscle), urine and stool samples using GCMS. Approximately 6.18% of CPF was distributed in the body tissues, and the highest CPF concentration (3.80%) was found in adipose tissue. CPF also accumulated in the liver (0.29%), brain (0.22%), kidney (0.10%), and ovary (0.03%). Approximately 83.60% of CPF was detected in the urine. CPF exposure resulted in a significant increase in plasma transaminases, alkaline phosphatase, and total bilirubin levels, a significant reduction in total protein levels and an altered lipid profile. Oxidative stress due to CPF administration was also evidenced by a significant increase in liver malondialdehyde levels. The detrimental effects of CPF on kidney function consisted of a significant increase in plasma urea and creatinine levels. Liver and kidney histology confirmed the observed biochemical changes. In conclusion, CPF bioaccumulates over time and exerts toxic effects on animals.
    MeSH terms: Animals; Chlorpyrifos/pharmacokinetics; Chlorpyrifos/toxicity*; Environmental Pollutants/pharmacokinetics; Environmental Pollutants/toxicity*; Female; Kidney/drug effects*; Kidney/metabolism; Kidney Function Tests; Liver/drug effects*; Liver/metabolism; Liver Function Tests; Gas Chromatography-Mass Spectrometry; Tissue Distribution; Lipid Peroxidation/drug effects; Rats, Wistar; Oxidative Stress/drug effects*
  12. Recent developments of zinc oxide based photocatalyst in water treatment technology: A review
    Lee KM, Lai CW, Ngai KS, Juan JC
    Water Res, 2016 Jan 01;88:428-448.
    PMID: 26519627 DOI: 10.1016/j.watres.2015.09.045
    Today, a major issue about water pollution is the residual dyes from different sources (e.g., textile industries, paper and pulp industries, dye and dye intermediates industries, pharmaceutical industries, tannery and craft bleaching industries, etc.), and a wide variety of persistent organic pollutants have been introduced into our natural water resources or wastewater treatment systems. In fact, it is highly toxic and hazardous to the living organism; thus, the removal of these organic contaminants prior to discharge into the environment is essential. Varieties of techniques have been employed to degrade those organic contaminants and advanced heterogeneous photocatalysis involving zinc oxide (ZnO) photocatalyst appears to be one of the most promising technology. In recent years, ZnO photocatalyst have attracted much attention due to their extraordinary characteristics. The high efficiency of ZnO photocatalyst in heterogeneous photocatalysis reaction requires a suitable architecture that minimizes electron loss during excitation state and maximizes photon absorption. In order to further improve the immigration of photo-induced charge carriers during excitation state, considerable effort has to be exerted to further improve the heterogeneous photocatalysis under UV/visible/solar illumination. Lately, interesting and unique features of metal doping or binary oxide photocatalyst system have gained much attention and became favourite research matter among various groups of scientists. It was noted that the properties of this metal doping or binary oxide photocatalyst system primarily depend on the nature of the preparation method and the role of optimum dopants content incorporated into the ZnO photocatalyst. Therefore, this paper presents a critical review of recent achievements in the modification of ZnO photocatalyst for organic contaminants degradation.
    MeSH terms: Photolysis*; Waste Disposal, Fluid*; Water Pollutants, Chemical/radiation effects*; Water Pollutants, Chemical/chemistry; Zinc Oxide/chemistry*; Water Purification*
  13. Continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surfaces
    Peng IC, Yeh CC, Lu YT, Muduli S, Ling QD, Alarfaj AA, et al.
    Biomaterials, 2016 Jan;76:76-86.
    PMID: 26519650 DOI: 10.1016/j.biomaterials.2015.10.039
    Stem cell culture is typically based on batch-type culture, which is laborious and expensive. Here, we propose a continuous harvest method for stem cells cultured on thermoresponsive nanobrush surfaces. In this method, stem cells are partially detached from the nanobrush surface by reducing the temperature of the culture medium below the critical solution temperature needed for thermoresponse. The detached stem cells are harvested by exchange into fresh culture medium. Following this, the remaining cells are continuously cultured by expansion in fresh culture medium at 37 °C. Thermoresponsive nanobrush surfaces were prepared by coating block copolymers containing polystyrene (for hydrophobic anchoring onto culture dishes) with three types of polymers: (a) polyacrylic acid with cell-binding oligopeptides, (b) thermoresponsive poly-N-isopropylacrylamide, and (c) hydrophilic poly(ethyleneglycol)methacrylate. The optimal coating durations and compositions for these copolymers to facilitate adequate attachment and detachment of human adipose-derived stem cells (hADSCs) and embryonic stem cells (hESCs) were determined. hADSCs and hESCs were continuously harvested for 5 and 3 cycles, respectively, via the partial detachment of cells from thermoresponsive nanobrush surfaces.
    MeSH terms: Human Embryonic Stem Cells; Acrylic Resins; Humans; Methacrylates; Oligopeptides; Polymers; Polystyrenes; Temperature; Cell Culture Techniques
  14. Investigation of the links between heterocyst and biohydrogen production by diazotrophic cyanobacterium A. variabilis ATCC 29413
    Salleh SF, Kamaruddin A, Uzir MH, Karim KA, Mohamed AR
    Arch Microbiol, 2016 Mar;198(2):101-13.
    PMID: 26521065 DOI: 10.1007/s00203-015-1164-6
    This work investigates the effect of heterocyst toward biohydrogen production by A. variabilis. The heterocyst frequency was artificially promoted by adding an amino acid analog, in this case DL-7-azatryptophan into the growth medium. The frequency of heterocyst differentiation was found to be proportional to the concentration of azatryptophan (0-25 µM) in the medium. Conversely, the growth and nitrogenase activity were gradually suppressed. In addition, there was also a distinct shortening of the cells filaments and detachment of heterocyst from the vegetative cells. Analysis on the hydrogen production performance revealed that both the frequency and distribution of heterocyst in the filaments affected the rate of hydrogen production. The highest hydrogen production rate and yield (41 µmol H2 mg chl a(-1) h(-1) and 97 mL H2 mg chl a(-1), respectively) were achieved by cells previously grown in 15 µM of azatryptophan with 14.5 % of heterocyst frequency. The existence of more isolated heterocyst has been shown to cause a relative loss in nitrogenase activity thus lowering the hydrogen production rate.
    MeSH terms: Amino Acids, Diamino; Cell Differentiation; Culture Media; Cytoskeleton; Hydrogen; Nitrogenase; Tryptophan
  15. Automatic Voice Pathology Detection With Running Speech by Using Estimation of Auditory Spectrum and Cepstral Coefficients Based on the All-Pole Model
    Ali Z, Elamvazuthi I, Alsulaiman M, Muhammad G
    J Voice, 2016 Nov;30(6):757.e7-757.e19.
    PMID: 26522263 DOI: 10.1016/j.jvoice.2015.08.010
    BACKGROUND AND OBJECTIVE: Automatic voice pathology detection using sustained vowels has been widely explored. Because of the stationary nature of the speech waveform, pathology detection with a sustained vowel is a comparatively easier task than that using a running speech. Some disorder detection systems with running speech have also been developed, although most of them are based on a voice activity detection (VAD), that is, itself a challenging task. Pathology detection with running speech needs more investigation, and systems with good accuracy (ACC) are required. Furthermore, pathology classification systems with running speech have not received any attention from the research community. In this article, automatic pathology detection and classification systems are developed using text-dependent running speech without adding a VAD module.

    METHOD: A set of three psychophysics conditions of hearing (critical band spectral estimation, equal loudness hearing curve, and the intensity loudness power law of hearing) is used to estimate the auditory spectrum. The auditory spectrum and all-pole models of the auditory spectrums are computed and analyzed and used in a Gaussian mixture model for an automatic decision.

    RESULTS: In the experiments using the Massachusetts Eye & Ear Infirmary database, an ACC of 99.56% is obtained for pathology detection, and an ACC of 93.33% is obtained for the pathology classification system. The results of the proposed systems outperform the existing running-speech-based systems.

    DISCUSSION: The developed system can effectively be used in voice pathology detection and classification systems, and the proposed features can visually differentiate between normal and pathological samples.

    MeSH terms: Acoustics*; Algorithms; Fourier Analysis; Humans; Pattern Recognition, Automated; Predictive Value of Tests; ROC Curve; Signal Processing, Computer-Assisted*; Sound Spectrography; Speech Acoustics*; Speech Production Measurement/methods*; Time Factors; Voice Disorders/classification; Voice Disorders/diagnosis*; Voice Disorders/physiopathology; Voice Quality*; Reproducibility of Results; Linear Models; Databases, Factual; Area Under Curve
  16. Mathematical model of organic substrate degradation in solid waste windrow composting
    Seng B, Kristanti RA, Hadibarata T, Hirayama K, Katayama-Hirayama K, Kaneko H
    Bioprocess Biosyst Eng, 2016 Jan;39(1):81-94.
    PMID: 26522660 DOI: 10.1007/s00449-015-1492-6
    Organic solid waste composting is a complex process that involves many coupled physical, chemical and biological mechanisms. To understand this complexity and to ease in planning, design and management of the composting plant, mathematical model for simulation is usually applied. The aim of this paper is to develop a mathematical model of organic substrate degradation and its performance evaluation in solid waste windrow composting system. The present model is a biomass-dependent model, considering biological growth processes under the limitation of moisture, oxygen and substrate contents, and temperature. The main output of this model is substrate content which was divided into two categories: slowly and rapidly degradable substrates. To validate the model, it was applied to a laboratory scale windrow composting of a mixture of wood chips and dog food. The wastes were filled into a cylindrical reactor of 6 cm diameter and 1 m height. The simulation program was run for 3 weeks with 1 s stepwise. The simulated results were in reasonably good agreement with the experimental results. The MC and temperature of model simulation were found to be matched with those of experiment, but limited for rapidly degradable substrates. Under anaerobic zone, the degradation of rapidly degradable substrate needs to be incorporated into the model to achieve full simulation of a long period static pile composting. This model is a useful tool to estimate the changes of substrate content during composting period, and acts as a basic model for further development of a sophisticated model.
  17. Landfill area estimation based on integrated waste disposal options and solid waste forecasting using modified ANFIS model
    Younes MK, Nopiah ZM, Basri NE, Basri H, Abushammala MF, Younes MY
    Waste Manag, 2016 Sep;55:3-11.
    PMID: 26522806 DOI: 10.1016/j.wasman.2015.10.020
    Solid waste prediction is crucial for sustainable solid waste management. The collection of accurate waste data records is challenging in developing countries. Solid waste generation is usually correlated with economic, demographic and social factors. However, these factors are not constant due to population and economic growth. The objective of this research is to minimize the land requirements for solid waste disposal for implementation of the Malaysian vision of waste disposal options. This goal has been previously achieved by integrating the solid waste forecasting model, waste composition and the Malaysian vision. The modified adaptive neural fuzzy inference system (MANFIS) was employed to develop a solid waste prediction model and search for the optimum input factors. The performance of the model was evaluated using the root mean square error (RMSE) and the coefficient of determination (R(2)). The model validation results are as follows: RMSE for training=0.2678, RMSE for testing=3.9860 and R(2)=0.99. Implementation of the Malaysian vision for waste disposal options can minimize the land requirements for waste disposal by up to 43%.
    MeSH terms: Developing Countries; Forecasting; Models, Theoretical*; Refuse Disposal/methods*; Refuse Disposal/statistics & numerical data; Solid Waste/statistics & numerical data*; Waste Disposal Facilities/statistics & numerical data*
  18. Fulltext The consequences of tinnitus and tinnitus severity on cognition: A review of the behavioural evidence
    Mohamad N, Hoare DJ, Hall DA
    Hear Res, 2016 Feb;332:199-209.
    PMID: 26523370 DOI: 10.1016/j.heares.2015.10.001
    People with tinnitus report anecdotal difficulties in mental concentration and psychological treatments for tinnitus advise on concentration difficulties and how to manage them. Yet the literature lacks any coherent discussion about what precise theoretical cognitive constructs might be mediating reported concentration problems. This review addresses this gap by describing and critically appraising the behavioural evidence for the effects of tinnitus on cognitive performance (namely working memory and attention). Empirical evidence is somewhat limited, but there is some support that tinnitus interferes with executive attention, and mixed support that it impairs working memory and selective attention. We highlight a number of methodological considerations to help drive the field forward and we propose a putative model of the complex inter-relationships between tinnitus, cognition and confounding factors. This model provides a basis for hypothesis testing.
    MeSH terms: Attention; Cognition*; Cognition Disorders/diagnosis; Cognition Disorders/etiology*; Humans; Memory, Short-Term; Risk Factors; Tinnitus/complications*; Tinnitus/diagnosis; Tinnitus/psychology; Executive Function
  19. Assessment of the migration potential of nanosilver from nanoparticle-coated low-density polyethylene food packaging into food simulants
    Hannon JC, Kerry JP, Cruz-Romero M, Azlin-Hasim S, Morris M, Cummins E
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2016;33(1):167-78.
    PMID: 26523861 DOI: 10.1080/19440049.2015.1114184
    An experimental nanosilver-coated low-density polyethylene (LDPE) food packaging was incubated with food simulants using a conventional oven and tested for migration according to European Commission Regulation No. 10/2011. The commercial LDPE films were coated using a layer-by-layer (LbL) technique and three levels of silver (Ag) precursor concentration (0.5%, 2% and 5% silver nitrate (AgNO3), respectively) were used to attach antimicrobial Ag. The experimental migration study conditions (time, temperature and food simulant) under conventional oven heating (10 days at 60°C, 2 h at 70°C, 2 h at 60°C or 10 days at 70°C) were chosen to simulate the worst-case storage period of over 6 months. In addition, migration was quantified under microwave heating. The total Ag migrant levels in the food simulants were quantified by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Mean migration levels obtained by ICP-AES for oven heating were in the range 0.01-1.75 mg l(-1). Migration observed for microwave heating was found to be significantly higher when compared with oven heating for similar temperatures (100°C) and identical exposure times (2 min). In each of the packaging materials and food simulants tested, the presence of nanoparticles (NPs) was confirmed by scanning electron microscopy (SEM). On inspection of the migration observed under conventional oven heating, an important finding was the significant reduction in migration resulting from the increased Ag precursor concentration used to attach Ag on the LDPE LbL-coated films. This observation merits further investigation into the LbL coating process used, as it suggests potential for process modifications to reduce migration. In turn, any reduction in NP migration below regulatory limits could greatly support the antimicrobial silver nanoparticle (AgNP)-LDPE LbL-coated films being used as a food packaging material.
    MeSH terms: Cooking; Food Analysis*; Food Handling; Heating; Silver/analysis*; Silver/chemistry*; Temperature; Food Packaging*; Polyethylene/chemistry*; Metal Nanoparticles/analysis*; Metal Nanoparticles/chemistry*
  20. Soluble inhibitors generated during hydrothermal pretreatment of oil palm mesocarp fiber suppressed the catalytic activity of Acremonium cellulase
    Zakaria MR, Hirata S, Fujimoto S, Ibrahim I, Hassan MA
    Bioresour Technol, 2016 Jan;200:541-7.
    PMID: 26524253 DOI: 10.1016/j.biortech.2015.10.075
    Oil palm mesocarp fiber was subjected to hydrothermal pretreatment under isothermal and non-isothermal conditions. The pretreated slurries were separated by filtration, pretreated liquids and solids were characterized. An enzymatic digestibility study was performed for both pretreated slurries and solids to understand the effect of soluble inhibitors generated during the pretreatment process. The highest glucose yield obtained from pretreated slurries was 70.1%, and gradually decreased with higher pretreatment severities. The highest glucose yield obtained in pretreated solids was 100%, after pretreatment at 210°C for 20min. In order to study the inhibitory effects of compounds generated during pretreatment with cellulase, technical grade solutions that mimic the pretreated liquid were prepared and their effect on Acremonium cellulase activity was monitored using Avicel. Xylo-oligomers and tannic acid were identified as powerful inhibitors of Acremonium cellulase, and the lowest hydrolysis rate of Avicel of 0.18g/g-glucose released/L/h was obtained from tannic acid.
    MeSH terms: Acremonium; Carbohydrates; Cellulase; Cellulose; Dietary Fiber; Filtration; Glucose; Hydrolysis; Tannins
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