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Production of organic acids from kitchen wastes

Loh CW, Fakhru'l-Razi A, Hassan MA, Karim MI

Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):455-9.
PMID: 10595448

This study involves the production of short-chain organic acids from kitchen wastes as intermediates for the production of biodegradable plastics. Flasks, without mixing were used for the anaerobic conversion of the organic fraction of kitchen wastes into short-chain organic acids. The influence of pH, temperature and addition of sludge cake on the rate of organic acids production and yield were evaluated. Fermentations were carried out in an incubator at different temperatures controlled at 30 degrees C. 40 degrees C, 50 degrees C, 60 degrees C and uncontrolled at room temperature. The pH was also varied at pH 5, 6, 7, and uncontrolled pH. 1.0 M phosphate buffer was used for pH control, and 1.0 M HCl and 1.0 M NaOH were added when necessary. Sludge cake addition enhanced the rate of maximum acids production from 4 days to 1 day. The organic acids produced were maximum at pH 7 and 50 degrees C i.e., 39.84 g/l on the fourth day of fermentation with a yield of 0.87 g/g soluble COD consumed, and 0.84 g/g TVS. The main organic acid produced was lactic acid (65-85%), with small amounts of acetic (10-30%), propionic (5-10%), and butyric (5-20%) acids. The results of this study showed that kitchen wastes could be fermented to high concentration of organic acids, which could be used as substrates for the production of biodegradable plastics.
Degumming of crude palm oil by membrane filtration

Ong KK, Fakhru'l-Razi A, Baharin BS, Hassan MA

Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):381-5.
PMID: 10595436

The application of membrane separation in palm oil refining process has potential for energy and cost savings. The conventional refining of crude palm oil results in loss of oil and a contaminated effluent. Degumming of crude palm oil by membrane technology is conducted in this study. The objective of this research is to study the feasibility of membrane filtration for the removal of phospholipids in the degumming of crude palm oil, including analyses of phosphorus content, carotene content free fatty acids (as palmitic acid), colour and volatile matter. A PCI membrane module was used which was equipped with polyethersulfone membranes having a molecular weight cut off of 9,000 (type ES209). In this study, phosphorus content was the most important parameter monitored. The membrane effectively removed phospholipids resulting in a permeate with a phosphorus content of less than 0.3 ppm The percentage removal of phosphorus was 96.4% and was considered as a good removal. Lovibond colour was reduced from 27R 50Y to 20R 30Y. The percentage removal of carotene was 15.8%. The removal of colour was considered good but the removal of carotene was considered insignificant by the membrane. Free fatty acids and volatile matter were not removed. Typical of membrane operations, the permeate flux decreased with time and must be improved in order to be adopted on an industrial scale. Membrane technology was found to have good potential in crude palm oil degumming. However, an appropriate method has to be developed to clean the membranes for reuse.
Feasibility study on the utilization of rubber latex effluent for producing bacterial biopolymers

Tang SN, Fakhru'l-Razi A, Hassan MA, Karim MI

Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):411-6.
PMID: 10595441

Rubber latex effluent is a polluting source that has a high biochemical oxygen demand (BOD). It is estimated that about 100 million liters of effluent are discharged daily from rubber processing factories. Utilization of this effluent such as the use of a coupled system not only can reduce the cost of treatment but also yield a fermentation feedstock for the production of bioplastic. This study initially was carried out to increase the production of organic acids by anaerobic treatment of rubber latex effluent. It was found that through anaerobic treatment the concentration of organic acids did not increase. Consequently, separation of organic acids from rubber latex effluent by anion exchange resin was examined as a preliminary study of recovering acetic and propionic acids. However, the suspended solids (SS) content in the raw effluent was rather high which partially blocked the ion-exchange columns. Lime was used to remove the SS in the rubber latex effluent. After the lime precipitation process, organic acids were found to adsorb strongly onto the anion exchange resin. Less adsorption of organic acids onto the resin was observed before the lime precipitation. This was probably due to more sites being occupied by colloidal particles on the resin thus inhibiting the adsorption of organic acids. The initial concentration of organic acids in the raw effluent was 3.9 g/L. After ion exchange, the concentration of the organic acids increased to 27 g/L, which could be utilized for production of polyhydroxyalkanoates (PHA). For PHA accumulation stage, concentrated rubber latex effluent obtained from ion exchange resins and synthetic acetic acid were used as the carbon source. Quantitative analyses from fed batch culture via HPLC showed that the accumulation of PHA in Alcaligenes eutrophus was maximum with a concentration of 1.182 g/L when cultivated on synthetic acetic acid, corresponding to a yield of 87% based on its cell dry weight. The dry cell weight increased from 0.71 to 1.67 g/L. On the other hand, using concentrated rubber latex effluent containing acetic and propionic acids resulted in reduced PHA content by dry weight (14%) but the dry cell weight increased from 0.49 to 1.30 g/L. The results clearly indicated that the cells grow well in rubber latex effluent but no PHA was accumulated. This could be due to the high concentration of propionic acid in culture broth or other factors such as heavy metals. Thus further work is required before rubber latex effluent can be utilized as a substrate for PHA production industrially.
Fulltext A halfway house for pregnant women

Ahmad Z, Jaafar R, Hassan MH, Awang CW

World Health Forum, 1998;19(2):133-5.
PMID: 9652210
Incidence of pain after biomechanical preparation: a review of 302 cases treated by dental students

Mohd Sulong MZ, Abu-Hassan MI, Abdul Razak AA, Embong A

Singapore Dent J, 1996 Jul;21(1):31-5.
PMID: 10597181

Records of 302 root-filled teeth treated by dental undergraduates were reviewed by four lecturers in the Department of Conservative Dentistry, University of Malaya. Preoperative and operative factors were evaluated for their association with postoperative pain experience of patients during the visit immediately after completion of biomechanical preparation. Eighty four percent of patients did not experience any pain after biomechanical preparation whilst the remaining 16 percent only complained of slight or moderate pain. The incidence of pain after biomechanical preparation is not high even when performed by inexperienced undergraduates. Teeth with a pre-existing painful condition had a higher chances of postoperative of pain. The incidence of postoperative pain was halved when teeth were associated with a sinus tract.
The application of a computerised recording system to smallholder dairy extension in Malaysia

Abu Hassan MA, Kamaruddin MI, Pharo HJ

Acta Vet Scand Suppl, 1988;84:110-2.
PMID: 3232593
Modified dynamic gracilis neosphincter for fecal incontinence: an analysis of functional outcome at a single institution

Hassan MZ, Rathnayaka MM, Deen KI

World J Surg, 2010 Jul;34(7):1641-7.
PMID: 20180122 DOI: 10.1007/s00268-010-0489-1

We undertook a prospective longitudinal study of patients with end-stage fecal incontinence who were undergoing transposition of the gracilis muscle as a neo-anal sphincter with external low-frequency electrical stimulation of the nerve to the gracilis combined with biofeedback.
Histopathology and cytopathology of white spot syndrome virus (WSSV) in cultured Penaeus monodon from peninsular Malaysia with emphasis on pathogenesis and the mechanism of white spot formation

Wang YG, Hassan MD, Shariff M, Zamri SM, Chen X

Dis Aquat Organ, 1999 Dec 22;39(1):1-11.
PMID: 11407399

Since 1994, white spot syndrome virus (WSSV) has been detected in cultured shrimp Penaeus monodon in Peninsular Malaysia. The gross signs, target organs and histo-cytopathology for the viral infection were studied and it was found to infect most organs and tissues including oocytes, but not hepatopancreatocytes and epithelial cells of the midgut, which were regarded as refractory tissues. Based on a time-sequence of ultrastructural cytopathology, 4 cytopathic profiles and 6 phases of viral morphogenesis were described. The virions were elliptical to short rods with trilamilar envelopes that measured 305 +/- 30 x 127 +/- 11 nm. Viral nucleosomes were often present singly in infected nuclei and were associated with the early stages of viral replication. The structure of WSSV pathognomonic white, cuticular lesions was examined at the microscopic and ultrastructural levels and the mechanism of their formation appeared to be related to the disruption of exudate transfer from epithelial cells to the cuticle via cuticular pore canals.
A new bacterial white spot syndrome (BWSS) in cultured tiger shrimp Penaeus monodon and its comparison with white spot syndrome (WSS) caused by virus

Wang YG, Lee KL, Najiah M, Shariff M, Hassan MD

Dis Aquat Organ, 2000 May 25;41(1):9-18.
PMID: 10907134

This paper describes a new bacterial white spot syndrome (BWSS) in cultured tiger shrimp Penaeus monodon. The affected shrimp showed white spots similar to those caused by white spot syndrome virus (WSSV), but the shrimp remained active and grew normally without significant mortalities. The study revealed no evidence of WSSV infection using electron microscopy, histopathology and nested polymerase chain reaction. Electron microscopy indicated bacteria associated with white spot formation, and with degeneration and discoloration of the cuticle as a result of erosion of the epicuticle and underlying cuticular layers. Grossly the white spots in BWSS and WSS look similar but showed different profiles under wet mount microscopy. The bacterial white spots were lichen-like, having perforated centers unlike the melanized dots in WSSV-induced white spots. Bacteriological examination showed that the dominant isolate in the lesions was Bacillus subtilis. The occurrence of BWSS may be associated with the regular use of probiotics containing B. subtilis in shrimp ponds. The externally induced white spot lesions were localized at the integumental tissues, i.e., cuticle and epidermis, and connective tissues. Damage to the deeper tissues was limited. The BWS lesions are non-fatal in the absence of other complications and are usually shed through molting.
Fulltext Biocompatibility and Cytotoxicity Study of Polydimethylsiloxane (PDMS) and Palm Oil Fuel Ash (POFA) Sustainable Super-Hydrophobic Coating for Biomedical Applications

Sreekantan S, Hassan M, Sundera Murthe S, Seeni A

Polymers (Basel), 2020 Dec 18;12(12).
PMID: 33352856 DOI: 10.3390/polym12123034

A sustainable super-hydrophobic coating composed of silica from palm oil fuel ash (POFA) and polydimethylsiloxane (PDMS) was synthesised using isopropanol as a solvent and coated on a glass substrate. FESEM and AFM analyses were conducted to study the surface morphology of the coating. The super-hydrophobicity of the material was validated through goniometry, which showed a water contact angle of 151°. Cytotoxicity studies were conducted by assessing the cell viability and cell morphology of mouse fibroblast cell line (L929) and hamster lung fibroblast cell line (V79) via tetrazolium salt 3-(4-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and microscopic methods, respectively. The clonogenic assay was performed on cell line V79 and the cell proliferation assay was performed on cell line L929. Both results validate that the toxicity of PDMS: SS coatings is dependent on the concentration of the super-hydrophobic coating. The results also indicate that concentrations above 12.5 mg/mL invariably leads to cell toxicity. These results conclusively support the possible utilisation of the synthesised super-hydrophobic coating for biomedical applications.
Psychometric Properties of a Theory of Planned Behavior Questionnaire for Assessing the Midwives' Intention to Provide Planned Home Birth Services in Nigeria

Muhammed A, Shariff-Ghazali S, Said SM, Hassan M, Lee K

J Community Health Nurs, 2020 4 3;37(2):77-88.
PMID: 32233947 DOI: 10.1080/07370016.2020.1736377

We developed and psychometrically tested a Theory of Planned Behavior (TPB) questionnaire which focused on assessing the midwives' intention to provide planned home birth (PHB) services. This is a quantitative, cross-sectional survey, conducted among 226 midwives working in ten participating health facilities. The reliability and validity of the theoretical constructs were assessed. The Cronbach's alpha values were >0.8 for all scales, suggesting satisfactory internal consistency. Confirmatory factor analysis revealed sufficient convergent validity (the average variance extracted was >0.5 for each construct) and discriminant validity. The study gathered an evidence of the usefulness of TPB in the specific context of PHB.
Knowledge and practice on medication adherence among Type II diabetes mellitus patients

Jamaludin TSS, Mohammad NM, Hassan M, Nurumal MS

Enferm Clin, 2021 04;31 Suppl 2:S372-S376.
PMID: 33849203 DOI: 10.1016/j.enfcli.2020.09.028

This study aimed to survey the level of knowledge and practice on medication adherence among Type II diabetes mellitus (DM) patients. A cross-sectional study was conducted with a total of 220 DM patients by using a convenience sampling method. It was found that 64.5% of studied participants have a high level of knowledge with good practice toward medication adherence. There was a significant association between sociodemographic characteristics with the level of knowledge and practice toward medication adherence. This study finding provides information to health care providers to improve their patient's care by playing their important role in promoting the importance of knowledge on medication adherence for a better quality of life to the DM patients. Not only a physician but also the nurse could enhance health education for their patient on medication adherence during the follow-up appointment.
Fulltext Novel NAD+-Farnesal Dehydrogenase from Polygonum minus Leaves. Purification and Characterization of Enzyme in Juvenile Hormone III Biosynthetic Pathway in Plant

Seman-Kamarulzaman AF, Mohamed-Hussein ZA, Ng CL, Hassan M

PLoS One, 2016;11(8):e0161707.
PMID: 27560927 DOI: 10.1371/journal.pone.0161707

Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold) to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that's highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate specificity towards farnesal. Thus, it was suggested that this novel enzyme may be functioning specifically to oxidize farnesal in the later steps of JH III pathway. This report provides a basic understanding for recombinant production of this particular enzyme. Other strategies such as adding His-tag to the protein makes easy the purification of the protein which is completely different to the native protein. Complete sequence, structure and functional analysis of the enzyme will be important for developing insect-resistant crop plants by deployment of transgenic plant.
Occurrence of human respiratory syncytial virus in summer in Japan

Shobugawa Y, Takeuchi T, Hibino A, Hassan MR, Yagami R, Kondo H, et al.

Epidemiol Infect, 2017 Jan;145(2):272-284.
PMID: 27682641

In temperate zones, human respiratory syncytial virus (HRSV) outbreaks typically occur in cold weather, i.e. in late autumn and winter. However, recent outbreaks in Japan have tended to start during summer and autumn. This study examined associations of meteorological conditions with the numbers of HRSV cases reported in summer in Japan. Using data from the HRSV national surveillance system and national meteorological data for summer during the period 2007-2014, we utilized negative binomial logistic regression analysis to identify associations between meteorological conditions and reported cases of HRSV. HRSV cases increased when summer temperatures rose and when relative humidity increased. Consideration of the interaction term temperature × relative humidity enabled us to show synergistic effects of high temperature with HRSV occurrence. In particular, HRSV cases synergistically increased when relative humidity increased while the temperature was ⩾28·2 °C. Seasonal-trend decomposition analysis using the HRSV national surveillance data divided by 11 climate divisions showed that summer HRSV cases occurred in South Japan (Okinawa Island), Kyushu, and Nankai climate divisions, which are located in southwest Japan. Higher temperature and higher relative humidity were necessary conditions for HRSV occurrence in summer in Japan. Paediatricians in temperate zones should be mindful of possible HRSV cases in summer, when suitable conditions are present.
Melt volume flow rate and melt flow rate of kenaf fibre reinforced Floreon/magnesium hydroxide biocomposites

Lee CH, Sapuan SM, Lee JH, Hassan MR

Springerplus, 2016;5(1):1680.
PMID: 27733982

A study of the melt volume flow rate (MVR) and the melt flow rate (MFR) of kenaf fibre (KF) reinforced Floreon (FLO) and magnesium hydroxide (MH) biocomposites under different temperatures (160-180 °C) and weight loadings (2.16, 5, 10 kg) is presented in this paper. FLO has the lowest values of MFR and MVR. The increment of the melt flow properties (MVR and MFR) has been found for KF or MH insertion due to the hydrolytic degradation of the polylactic acid in FLO. Deterioration of the entanglement density at high temperature, shear thinning and wall slip velocity were the possible causes for the higher melt flow properties. Increasing the KF loadings caused the higher melt flow properties while the higher MH contents created stronger bonding for higher macromolecular chain flow resistance, hence lower melt flow properties were recorded. However, the complicated melt flow behaviour of the KF reinforced FLO/MH biocomposites was found in this study. The high probability of KF-KF and KF-MH collisions was expected and there were more collisions for higher fibre and filler loading causing lower melt flow properties.
Predictors of midwives' intention to provide planned home birth services to low-risk women: A theory of planned behaviour approach

Muhammed A, Khuan L, Shariff-Ghazali S, Said SM, Hassan M

Midwifery, 2019 Jun;73:62-68.
PMID: 30884373 DOI: 10.1016/j.midw.2019.03.004

OBJECTIVE: Planned home birth may increase women's access to skilled midwives in all settings. Using theory to understand and predict midwives' intention regarding planned home birth services is rare. Therefore, using the theory of planned behaviour, we determined the factors associated with midwives' intention to provide planned home birth services to low-risk women.
DESIGN: This cross-sectional study adopted a quantitative approach and a survey. Stratified random sampling was used to recruit 226 midwives in Sokoto, Nigeria. Data-including descriptive statistic and multiple linear regression analyses-were analysed using SPSS 23 and significant was set at 0.05.
SETTING: Ten public health facilities in Sokoto, northwestern Nigeria.
PARTICIPANTS: Among all 460 midwives (women aged 20-60 years), working in the maternity wards of health facilities in Sokoto, a sample of 226 midwives was calculated using a power of 0.80 and a 95% confidence interval.
FINDINGS: The multiple linear regression analyses confirmed that the major factors associated with midwives' intention to provide planned home birth services were midwives' attitude towards planned home birth (p < .001) and midwives' previous experience with planned home birth practice (p = .008).
CONCLUSIONS AND IMPLICATIONS: The theory of planned behaviour is a useful framework for identifying factors that affect midwives' intention to provide planned home birth services. While future research may employ a qualitative approach to explore other factors, planned home birth education campaigns should target information that enhances positive attitude and encourages midwives to provide planned home birth services.
Fulltext Towards health monitoring using remote heart rate measurement using digital camera: A feasibility study

Hassan MA, Malik AS, Fofi D, Karasfi B, Meriaudeau F

Measurement : journal of the International Measurement Confederation, 2020 Jan;149:106804.
PMID: 32287815 DOI: 10.1016/j.measurement.2019.07.032

The paper presents a feasibility study for heart rate measurement using a digital camera to perform health monitoring. The feasibility study investigates the reliability of the state of the art heart rate measuring methods in realistic situations. Therefore, an experiment was designed and carried out on 45 subjects to investigate the effects caused by illumination, motion, skin tone, and distance variance. The experiment was conducted for two main scenarios; human-computer interaction scenario and health monitoring scenario. The human-computer scenario investigated the effects caused by illumination variance, motion variance, and skin tone variance. The health monitoring scenario investigates the feasibility of health monitoring at public spaces (i.e. airports, subways, malls). Five state of the art heart rate measuring methods were re-implemented and tested with the feasibility study database. The results were compared with ground truth to estimate the heart rate measurement error. The heart rate measurement error was analyzed using mean error, standard deviation; root means square error and Pearson correlation coefficient. The findings of this experiment inferred promising results for health monitoring of subjects standing at a distance of 500 cm.
Fulltext Cutaneous manifestation mimicking Stevens-Johnson syndrome in a critically ill patient: looks similar but totally different

Lim JA, Chong SE, Zainal Abidin H, Hassan MH

Hong Kong Med J, 2017 12;23(6):653.e3-4.
PMID: 29226836 DOI: 10.12809/hkmj165051
Novel health monitoring method using an RGB camera

Hassan MA, Malik AS, Fofi D, Saad N, Meriaudeau F

Biomed Opt Express, 2017 Nov 01;8(11):4838-4854.
PMID: 29188085 DOI: 10.1364/BOE.8.004838

In this paper we present a novel health monitoring method by estimating the heart rate and respiratory rate using an RGB camera. The heart rate and the respiratory rate are estimated from the photoplethysmography (PPG) and the respiratory motion. The method mainly operates by using the green spectrum of the RGB camera to generate a multivariate PPG signal to perform multivariate de-noising on the video signal to extract the resultant PPG signal. A periodicity based voting scheme (PVS) was used to measure the heart rate and respiratory rate from the estimated PPG signal. We evaluated our proposed method with a state of the art heart rate measuring method for two scenarios using the MAHNOB-HCI database and a self collected naturalistic environment database. The methods were furthermore evaluated for various scenarios at naturalistic environments such as a motion variance session and a skin tone variance session. Our proposed method operated robustly during the experiments and outperformed the state of the art heart rate measuring methods by compensating the effects of the naturalistic environment.
Fulltext Chronic Viral Hepatitis in Malaysia: "Where are we now?"

Raihan R, Mohamed R, Radzi Abu Hassan M, Md Said R

Euroasian J Hepatogastroenterol, 2017 Jan-Jun;7(1):65-67.
PMID: 29201775 DOI: 10.5005/jp-journals-10018-1214

Malaysia is a country where an estimated 1 million people are chronically infected with hepatitis B virus (HBV) and an estimated 2.5% of the adult population are positive for antibody to hepatitis C virus (HCV). Effective nationwide vaccine coverage seems to be a highly effective measure to prevent new HBV infection. Treatment of HCV infection is also a regular practice in Malaysia. These measures highlight the possibility to reach the World Health Organization elimination target by 2030. To achieve this target, the Health Ministry and other nongovernmental organizations, such as My Commitment to Cure (MyC2C) are working together to develop a strategic road map to reach the global elimination target in Malaysia by 2030. How to cite this article: Raihan R, Mohamed R, Hasan MRA, Rosaida MS. Chronic Viral Hepatitis in Malaysia: "Where are we now?" Euroasian J Hepato-Gastroenterol 2017;7(1):65-67.

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