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Malachite green adsorption by rattan sawdust: isotherm, kinetic and mechanism modeling

Hameed BH, El-Khaiary MI

J Hazard Mater, 2008 Nov 30;159(2-3):574-9.
PMID: 18387735 DOI: 10.1016/j.jhazmat.2008.02.054

In this work, the adsorption of malachite green (MG) on rattan sawdust (RSD) was studied at 30 degrees C. The results indicated that RSD can be used as a low-cost adsorbent for the removal of MG dye from aqueous solutions. Equilibrium data were analyzed by two isotherms, namely the Freundlich isotherm and the Langmuir isotherm. The best fit to the data was obtained with the Langmuir isotherm. The monolayer adsorption capacity of RSD was found to be 62.71 mg/g. The adsorption kinetics can be predicted by the pseudo-first-order model. The mechanism of adsorption was also studied. It was found that for a short time period the rate of adsorption is controlled by film diffusion. However, at longer adsorption times, pore-diffusion controls the rate of adsorption. The amount adsorbed on the outer surface was estimated from the time where film-diffusion stops controlling the adsorption rate.

Matched MeSH terms: Dust/analysis; Industrial Waste/analysis
Removal of phenol from aqueous solutions by adsorption onto activated carbon prepared from biomass material

Hameed BH, Rahman AA

J Hazard Mater, 2008 Dec 30;160(2-3):576-81.
PMID: 18434009 DOI: 10.1016/j.jhazmat.2008.03.028

Activated carbon derived from rattan sawdust (ACR) was evaluated for its ability to remove phenol from an aqueous solution in a batch process. Equilibrium studies were conducted in the range of 25-200mg/L initial phenol concentrations, 3-10 solution pH and at temperature of 30 degrees C. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. Equilibrium data fitted well to the Langmuir model with a maximum adsorption capacity of 149.25mg/g. The dimensionless separation factor RL revealed the favorable nature of the isotherm of the phenol-activated carbon system. The pseudo-second-order kinetic model best described the adsorption process. The results proved that the prepared activated carbon was an effective adsorbent for removal of phenol from aqueous solution.

Matched MeSH terms: Dust
Nuclear magnetic resonance structure and IgE epitopes of Blo t 5, a major dust mite allergen

Chan SL, Ong TC, Gao YF, Tiong YS, Wang de Y, Chew FT, et al.

J Immunol, 2008 Aug 15;181(4):2586-96.
PMID: 18684949

A high incidence of sensitization to Blomia tropicalis, the predominant house dust mite species in tropical regions, is strongly associated with allergic diseases in Singapore, Malaysia, and Brazil. IgE binding to the group 5 allergen, Blo t 5, is found to be the most prevalent among all B. tropicalis allergens. The NMR structure of Blo t 5 determined represents a novel helical bundle structure consisting of three antiparallel alpha-helices. Based on the structure and sequence alignment with other known group 5 dust mite allergens, surface-exposed charged residues have been identified for site-directed mutagenesis and IgE binding assays. Four charged residues, Glu76, Asp81, Glu86, and Glu91 at around the turn region connecting helices alpha2 and alpha3 have been identified to be involved in the IgE binding. Using overlapping peptides, we have confirmed that these charged residues are located on a major putative linear IgE epitope of Blo t 5 from residues 76-91 comprising the sequence ELKRTDLNILERFNYE. Triple and quadruple mutants have been generated and found to exhibit significantly lower IgE binding and reduced responses in skin prick tests. The mutants induced similar PBMC proliferation as the wild-type protein but with reduced Th2:Th1 cytokines ratio. Mass screening on a quadruple mutant showed a 40% reduction in IgE binding in 35 of 42 sera of atopic individuals. Findings in this study further stressed the importance of surface-charged residues on IgE binding and have implications in the cross-reactivity and use of Blo t 5 mutants as a hypoallergen for immunotherapy.

Matched MeSH terms: Dust/immunology
Fulltext Monitoring of radionuclide contamination in food samples in Malaysia due to daiichi reactor accident in Fukushima, Japan

Nurrul Assyikeen Md. Jaffary, Wo, Yii Mei, Abdul Kadir Ishak, Noor Fadzilah Yusof, Kamarozaman Ishak, Maziah Mahmud, et al.

Jurnal Sains Nuklear Malaysia, 2015;27(1):14-20.
MyJurnal

On March 11, 2011, a serious accident occurred in Daiichi nuclear reactor plant, Fukushima,
Japan which caused radioactive materials been released into the atmosphere in the form of
aerosols and dust particles. Sea water around the plant was also found contaminated with high
radioactivity readings. These radioactive materials could be transported by the winds and ocean
current across international borders and cannot be controlled by human. Thus, a continuous
monitoring activity of radionuclide content in the air and sea water needs to be conducted by the
authorities. In addition to radioactivity monitoring, Malaysia should also control the entry of
contaminated food in order to prevent radionuclide ingestion by human. The radionuclide 131I,
134Cs and 137Cs were used as a measure of pollution levels and counted with gamma spectrometry
using standard analysis method suggested by AOAC International. In this paper, details description
of the role of Radiochemical and Environment Group, Nuclear Malaysia who’s responsible in
analyzing the radioactivity in the food samples due to Fukushima Daiichi, Japan accident was
included. The radioactivity limit adopted and analysis results from this monitoring were discussed

Matched MeSH terms: Dust
Thermal radiation effects on heat and mass transfer of magnetohydrodynamics dusty jeffrey fluid past an exponentially stretching sheet

Siti Nur Haseela Izani, Anati Ali

MATEMATIKA, 2019;35(2):187-200.
MyJurnal

The heat and mass transfer of steady magnetohydrodynamics of dusty Jeffrey fluid past an exponentially stretching sheet in the presence of thermal radiation have been investigated. The main purpose of this study is to conduct a detailed analysis of flow behaviour of suspended dust particles in non-Newtonian fluid. The governing equations hav been converted into dimensionless form, and then solved numerically via the Keller-box method. The expression of Sherwood number, Nusselt number and skin friction have been evaluated, and then displayed in tabular forms. Velocity, temperature and concentration profiles are presented graphically. It is observed that large value of dust particles mass concentration parameter has reduced the flow velocity significantly. Increase in radiation parameter enhances the temperature, whereas the increment in Schmidt number parameter reduces the concentration.

Matched MeSH terms: Dust
Fulltext Association of exposure to PM2.5 and PM10 with DNA damage in exfoliated buccal mucosa cells among primary school children living nearby palm oil activity at Semenyih, Selangor

Syhidatul Farhana Othman, Juliana Jalaludin, Nur Hazirah Hisamuddin, Noeroel Widajati

Malaysian Journal of Medicine and Health Sciences, 2019;15(204):130-135.
MyJurnal

Introduction: Exposure of PM2.5 and PM10 released from combustion of biomass activity caused respiratory health among children. Objective: This study aims to determine the association between exposure of PM2.5 and PM10 with DNA damage in primary school children living nearby palm oil combustion activity at Semenyih. Methods: A cross sectional comparative study were conducted among Malay primary school children in school A located 2.7km from palm oil activity (N=82) and school B located about 40km away from the palm oil area (N=85). A standardized ques- tionnaire were distributed to respondent’s parents. Concentrations of PM2.5 and PM10 were measured by using Dust Trak DRX Aerosol Monitor Model 8534 and Escort LC Personal Sampling Pump. Measurement of indoor and outdoor air pollutants were conducted in schools and home. Buccal cells were collected, which then followed by micronu- cleus assay. Results: Concentration of PM10 and PM2.5 at home of studied group were significantly higher compared to comparative group with p value (p=0.007) and (p=0.018) respectively. PM10 and PM2.5 of studied schools were significantly higher compared to comparative schools with p value (p=0.014) and (p=0.04) respectively. MN fre- quencies of studied group were significantly higher compared to comparative group (p=0.001). Significant difference of respiratory symptoms were found between two groups which are cough, phlegm, wheezing and chest tightness (p=0.001). There were significant correlation between PM10 with MN frequency of studied group and comparative group with r= 0.562; p=0.001. Conclusion: This study indicated that the exposure of PM10 and PM2.5 would increase the risk of having respiratory health symptoms and might induce the micronuclei formation among children who lived near palm oil activity area.

Matched MeSH terms: Dust
Fulltext Respiratory symptoms and pulmonary function among male steel workers in Terengganu, Malaysia

Nurul, A.H., Shamsul Bahri, M.T., Noor Hassim, I.

Malaysian Journal of Public Health Medicine, 2014;14(1):10-18.
MyJurnal

A cross sectional study was carried out to determine the relationship between dust exposure and pulmonary function in male steel workers in Terengganu, Malaysia. The investigation included spirometric testing and detailed personal interviews using a structured questionnaire adopted from British Medical Research Council (BRMC) Questionnaire on respiratory symptoms. Respiratory symptoms commonly reported by the male workers were morning phlegm (33.1%), shortness of breath (31.9%), chest tightness (30.4%), and morning cough (17.8%). Age and duration of employment were among the factors associated with respiratory symptoms (p

Matched MeSH terms: Dust
Fulltext Respiratory symptoms and pulmonary function among male quarry workers in Kelantan, Malaysia.

Razlan Musa, Lin Naing, Zulkifli Ahmad, Rusli Nordin

Malaysian Journal of Public Health Medicine, 2002;2(1):54-57.
MyJurnal

The relationship between dust exposure and lung function were investigated in a cross-sectional study of 70 male quarry workers. The investigation included spirometric testing and detailed personal interviews using a structured questionnaire adapted from British Medical Research Council questionnaire on respiratory symptoms. Respiratory symptoms commonly reported by the male workers were shortness of breath (42.9%), chest tightness (37.1 %}, morning phlegm (20.0%) and morning cough (0.8%}. Prevalence of respiratory symptoms was greater in current smokers. Age and duration of employment also had significant relationship with chest tightness. Both FEV, and FVC of these workers were significantly reduced when compared to healthy population. Smoking status, age, and duration of employment were also associated with reduced pulmonary function (p<0.01).
Key words: respiratory symptoms, lung function and quarry workers

Matched MeSH terms: Dust
Fungal DNA, allergens, mycotoxins and associations with asthmatic symptoms among pupils in schools from Johor Bahru, Malaysia

Cai GH, Hashim JH, Hashim Z, Ali F, Bloom E, Larsson L, et al.

Pediatr Allergy Immunol, 2011 May;22(3):290-7.
PMID: 21457336 DOI: 10.1111/j.1399-3038.2010.01127.x

While there is a large variation of prevalence of asthma symptoms worldwide, what we do know is that it is on the rise in developing countries. However, there are few studies on allergens, moulds and mycotoxin exposure in schools in tropical countries. The aims were to measure selected fungal DNA, furry pet allergens and mycotoxins in dust samples from schools in Malaysia and to study associations with pupils' respiratory health effects. Eight secondary schools and 32 classrooms in Johor Bahru, Malaysia were randomly selected. A questionnaire with standardized questions was used for health assessment in 15 randomly selected pupils from each class. The school buildings were inspected and both indoor and outdoor climate were measured. Dust samples were collected by cotton swabs and Petri dishes for fungal DNA, mycotoxins and allergens analysis. The participation rate was 96% (462/480 invited pupils), with a mean age of 14 yr (range 14-16). The pupils mostly reported daytime breathlessness (41%), parental asthma or allergy (22%), pollen or pet allergy (21%) and doctor-diagnosed asthma (13%) but rarely reported night-time breathlessness (7%), asthma in the last 12 months (3%), medication for asthma (4%) or smoking (5%). The inspection showed that no school had any mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures. The mean building age was 16 yr (range 3-40) and the mean indoor and outdoor CO(2) levels were 492 ppm and 408 ppm, respectively. The mean values of indoor and outdoor temperature and relative humidity were the same, 29°C and 70% respectively. In cotton swab dust samples, the Geometric Mean (GM) value for total fungal DNA and Aspergillus/Penicillium (Asp/Pen) DNA in swab samples (Cell Equivalents (CE)/m(2)) was 5.7*10(8) and 0.5*10(8), respectively. The arithmetic mean (CE/m(2)) for Aspergillus versicolor DNA was 8780, Stachybotrys chartarum DNA was 26 and Streptomyces DNA was 893. The arithmetic means (pg/m(2)) for the mycotoxins sterigmatocystin and verrucarol were 2547 and 17, respectively. In Petri dish dust samples, the GM value for total fungal DNA and Asp/Pen DNA (CE/m(2) per day) was 9.2*10(6) and 1.6*10(6), respectively. The arithmetic mean (CE/m(2) per day) for A. versicolor DNA was 1478, S. chartarum DNA was 105 and Streptomyces DNA was 1271, respectively. The GM value for cat (Fel d1) allergen was 5.9 ng/m(2) per day. There were positive associations between A. versicolor DNA, wheeze and daytime breathlessness and between Streptomyces DNA and doctor-diagnosed asthma. However, the associations were inverse between S. chartarum DNA and daytime breathlessness and between verrucarol and daytime breathlessness. In conclusion, fungal DNA and cat allergen contamination were common in schools from Malaysia and there was a high prevalence of respiratory symptoms among pupils. Moreover, there were associations between levels of some fungal DNA and reported respiratory health in the pupils.

Matched MeSH terms: Dust/analysis*
Fulltext Removal of dissolved organic carbon from peat swamp runoff using assorted tropical agriculture biomass

Sim, F.S., Mohd Irwan Lu, N.A.L., Lee, Z.E.T., Mohamed, M.

Pertanika Journal of Science & Technology, 2015;23(1):51-59.
MyJurnal

In this study, agriculture biomass was used to remove dissolved organic matter from peat swamp runoff. The functional groups and morphological properties of 6 tropical agriculture biomasses (coconut husk, rice husk, empty fruit bunch, sago hampas, saw dust and banana trunk) in their raw and citric acid–treated states were examined. The Fourier transform infrared (FTIR) spectra showed that various biomasses were typically characterised with lignocellulosic compounds. The spectra analysis further demonstrated that citric acid treatment resulted in the dissolution of lignin and hemicelluloses to various extents where carboxyl groups were also introduced. These changes hypothetically suggest improved adsorption ability. Treatment of peat swamp runoff with various untreated biomasses showed no adsorption. With the modified biomass, adsorption was evidenced, with rice husk illustrating the highest removal efficiency of 60% to 65%.The biosorbent can be used in the water treatment process especially for treating water with a high dissolved organic matter content. The spent sorbent can be subsequently applied as a soil conditioner as the dissolved organic fraction, commonly known as humic matter, possesses important agricultural value.

Matched MeSH terms: Dust
First Report of Podosphaera fusca Causing Powdery Mildew of Cosmos caudatus in Malaysia

Siddiqui Y, Sariah M, Kausar H

Plant Dis, 2011 Apr;95(4):495.
PMID: 30743349 DOI: 10.1094/PDIS-12-10-0866

Cosmos caudatus Kunth. (Asteraceae), commonly known as ulam raja, is widely grown as an herbal aromatic shrub. In Malaysia, its young leaves are popularly eaten raw as salad with other greens and have been reported to possess extremely high antioxidant properties, which may be partly responsible for some of its believed medicinal functions. In early 2010, a suspected powdery mildew was observed on ulam raja plants at the Agricultural Park of Universiti Putra Malaysia. Initially, individual, white, superficial colonies were small and almost circular. Later, they enlarged and coalesced to cover the whole abaxial leaf surface. With development of the disease, all green parts (leaves, stems, and petioles) became covered with a continuous mat of mildew, giving a dusty appearance. Newly emerged leaves rapidly became infected. Diseased leaves ultimately senesced and dried up, making them aesthetically unattractive and unmarketable. The pathogen produced conidia in short chains (four to six conidia) on erect conidiophores. Conidiophores were unbranched, cylindrical, 125 to 240 μm long, with a slightly swollen foot cell. Individual conidia were hyaline, ellipsoid, and 25 to 30 (27.5) × 15 to 20 (17.5) μm with fibrosin inclusions. Morphological descriptions were consistent with those described for Sphaerotheca fuliginea or S. fusca, which has lately been reclassified as Podosphaera fusca (1). From extracted genomic DNA of P. fusca UPM UR1, the internal transcribed spacer (ITS) region was amplified with ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'). A BLAST search of GenBank with an ITS rDNA sequence of this fungus (GenBank Accession No. HQ589357) showed a maximum identity of 98% to the sequences of two P. fusca isolates (GenBank Accession Nos. AB525915.1 and AB525914.1). To satisfy Koch's postulates, the pathogenicity of fungal strain UPM UR1 was verified on 4-week-old plants. Inoculation was carried out by gently rubbing infected leaves onto healthy plants of C. caudatus. Ten pots of inoculated plants were kept under a plastic humid chamber and 10 pots of noninoculated plants, placed under another chamber, served as controls. After 48 h, the plants were then placed under natural conditions (25 to 28°C). Powdery mildew symptoms, similar to those on diseased field plants, appeared after 7 days on all inoculated plants. The white, superficial colonies enlarged and merged to cover large areas within 2 weeks. The infected leaf tissues became necrotic 6 to 8 days after the appearance of the first symptoms. Sporulation of P. fusca was observed on all infected leaves and stems. No symptoms were seen on the control plants. To our knowledge, this is the first report of P. fusca causing powdery mildew on C. caudatus in Malaysia. This pathogen has also been reported previously to be economically important on a number of other hosts. With ulam raja plants, more attention should be given to prevention and control measures to help manage this disease. Reference: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000.

Matched MeSH terms: Dust
Fulltext Endotoxin, ergosterol, fungal DNA and allergens in dust from schools in Johor Bahru, Malaysia- associations with asthma and respiratory infections in pupils

Norbäck D, Markowicz P, Cai GH, Hashim Z, Ali F, Zheng YW, et al.

PLoS One, 2014;9(2):e88303.
PMID: 24523884 DOI: 10.1371/journal.pone.0088303

There are few studies on associations between respiratory health and allergens, fungal and bacterial compounds in schools in tropical countries. The aim was to study associations between respiratory symptoms in pupils and ethnicity, chemical microbial markers, allergens and fungal DNA in settled dust in schools in Malaysia. Totally 462 pupils (96%) from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated. Dust was vacuumed from 32 classrooms and analysed for levels of different types of endotoxin as 3-hydroxy fatty acids (3-OH), muramic acid, ergosterol, allergens and five fungal DNA sequences. Multiple logistic regression was applied. Totally 13.1% pupils reported doctor's diagnosed asthma, 10.3% wheeze and 21.1% pollen or pet allergy. Indian and Chinese children had less atopy and asthma than Malay. Carbon dioxide levels were low (380-690 ppm). No cat (Fel d1), dog (Can f 1) or horse allergens (Ecu cx) were detected. The levels of Bloomia tropicalis (Blo t), house dust mite allergens (Der p 1, Der f 1, Der m 1) and cockroach allergens (Per a 1 and Bla g 1) were low. There were positive associations between levels of Aspergillus versicolor DNA and daytime breathlessness, between C14 3-OH and respiratory infections and between ergosterol and doctors diagnosed asthma. There were negative (protective) associations between levels of C10 3-OH and wheeze, between C16 3-OH and day time and night time breathlessness, between cockroach allergens and doctors diagnosed asthma. Moreover there were negative associations between amount of fine dust, total endotoxin (LPS) and respiratory infections. In conclusion, endotoxin at school seems to be mainly protective for respiratory illness but different types of endotoxin could have different effects. Fungal contamination measured as ergosterol and Aspergillus versicolor DNA can be risk factors for respiratory illness. The ethnical differences for atopy and asthma deserve further attention.

Matched MeSH terms: Dust
Fulltext Rhinitis, Ocular, Throat and Dermal Symptoms, Headache and Tiredness among Students in Schools from Johor Bahru, Malaysia: Associations with Fungal DNA and Mycotoxins in Classroom Dust

Norbäck D, Hashim JH, Cai GH, Hashim Z, Ali F, Bloom E, et al.

PLoS One, 2016;11(2):e0147996.
PMID: 26829324 DOI: 10.1371/journal.pone.0147996

There are few studies on rhinitis and sick building syndrome (SBS) among students in tropical countries. We studied associations between levels of five fungal DNA sequences, two mycotoxins (sterigmatocystin and verrucarol) and cat allergen (Fel d 1) levels in schools and rhinitis and other weekly SBS symptoms in the students. Fungal DNA was measured by quantitative PCR and cat allergen by ELISA. Pupils (N = 462) from eight randomly selected schools in Johor Bahru, Malaysia participated (96%). Dust samples were collected by cotton swabs and Petri dishes exposed for one week. None of the schools had a mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures and indoor CO2 levels were low (mean 492 ppm; range 380-690 ppm). Weekly nasal symptoms (rhinitis) (18.8%), ocular (11.6%), throat (11.1%), dermal symptoms, headache (20.6%) and tiredness (22.1%) were common. Total fungal DNA in swab samples was associated with rhinitis (p = 0.02), ocular symptoms (p = 0.009) and tiredness (p = 0.001). There were positive associations between Aspergillus versicolor DNA in Petri dish samples, ocular symptoms (p = 0.02) and tiredness (p = 0.001). The level of the mycotoxin verrucarol (produced by Stachybotrys chartarum) in swab samples was positively associated with tiredness (p = 0.04). Streptomyces DNA in swab samples (p = 0.03) and Petri dish samples (p = 0.03) were negatively associated with tiredness. In conclusion, total fungal contamination, measured as total fungal DNA) in the classrooms, Aspergillus versicolor and verrucarol can be risk factors for rhinitis and SBS symptoms among students in the tropical country Malaysia.

Matched MeSH terms: Dust/analysis*
Radiation dose assessment at amang processing plants in Malaysia

Omar M, Sulaiman I, Hassan A, Wood AK

Radiat Prot Dosimetry, 2007;124(4):400-6.
PMID: 17510205

Measurements of external radiation level, radon/thoron daughters concentrations in air and uranium/thorium concentrations in airborne mineral dust at 16 amang plants in Malaysia were carried out for three consecutive months to assess radiation dose to workers. Estimated occupational dose was within the range of 1.7-10.9 mSv y(-1). The mean total dose at the amang plants was 4.1 mSv y(-1). Overall, it was found that the major dose contribution of 80% came from external radiation. Radon/thoron daughters and airborne mineral dust contributed to only 11 and 9% of the total dose, respectively.

Matched MeSH terms: Dust/analysis
Fulltext Concentration of insecticides cypermethrin isomer in total suspended particulate in air of Cameron Highlands, Pahang, Malaysia

Norela Sulaiman, Toh LF, Hazzila Abdul Samat, Ismail Sahid, Maimon Abdullah, Mohd. Rozali Othman

Sains Malaysiana, 2007;36(2):91-95.

This study was carried out to determine the concentrations of cypermethrin in total suspended particulate in air in several farming areas of Cameron Highlands. Samples of total suspended particulate were collected using a high volume air sampler (Model Graseby) from six different sampling sites around Cameron Highlands. Laboratory analysis of total suspended particulate was conducted by the standard method. High dosages of cypermethrin were used by farmers in the dry season. Results of the study showed that the concentrations of cypermethrin in total suspended particulate in the air samples were higher during the dry season (May-July 2004) compared to the rainy season (September-October 2004). There was a significant positive correlation between the concentrations of cypermethrin and total suspended particulate (p<0.05).

Matched MeSH terms: Dust
Fulltext Determination of elements (Cd, Cu, Fe, Pb and Zn) in Universiti Teknologi MARA (UiTM) Hostel Shah Alam, Malaysia

Nurzulaifa Shaheera Erne Mohd Yasim, Siti Khadijah Mat Yaacob, Noradila Mohamed

Science Letters, 2018;12(2):28-36.
MyJurnal

The purpose of this study is to determine the concentration of the selected elemental composition in a multi-storey hostel. Dust samples were taken from three random rooms at each level of the student hostel by sweeping the floor. The concentrations of elements (Cd, Cu, Fe, Pb and Zn) were determined by using Inductively Coupled Plasma-Optical Emission Spectrometer (ICPOES) after digestion with nitric acid and sulfuric acid solutions. Dust samples analysis has shown the different levels of sampling point does not affect the concentration of the elements. The concentration of elements in investigated microenvironment was in the order of Fe > Zn > Cu > Pb > Cd. The correlation analysis was applied to elements variable in order to identify the sources of an airborne contaminant. It was discovered the strong positive correlation between Cu-Zn which indicates the sources come from traffic emission and street dust. This result was supported by the Principal Component Analysis (PCA) that revealed the presence of elements in the student hostel originated from the outdoor sources.

Matched MeSH terms: Dust
Fulltext Ganoderma neo-japonicum Imazeki revisited: Domestication study and antioxidant properties of its basidiocarps and mycelia

Tan WC, Kuppusamy UR, Phan CW, Tan YS, Raman J, Anuar AM, et al.

Sci Rep, 2015;5:12515.
PMID: 26213331 DOI: 10.1038/srep12515

Mushroom cultivation benefits humankind as it deliberately encourages wild mushrooms to be commercially propagated while recycling agricultural wastes. Ganoderma neo-japonicum is a rare polypore mushroom found growing on decaying Schizostachyum brachycladium (a tropical bamboo) clumps in Malaysia. The Malaysian indigenous tribes including the Temuans and Temiars use the basidiocarps of G. neo-japonicum to treat various ailments including diabetes. In this study, the domestication of G. neo-japonicum in artificial logs of different agricultural residues was investigated. Sawdust promoted the mycelia spawn colonisation in the shortest period of 38 ± 0.5 days. However, only sawdust and bamboo dust supported the primodia formation. Complex medium supported mycelium growth in submerged cultures and 27.11 ± 0.43 g/L of mycelia was obtained after 2 weeks of cultivation at 28 °C and 200 rpm. Antioxidant potential in mushroom may be influenced by different cultivation and extraction methods. The different extracts from the wild and cultivated basidiocarps as well as mycelia were then tested for their antioxidant properties. Aqueous and ethanol extracts of mycelia and basidiocarps tested had varying levels of antioxidant activities. To conclude, domestication of wild G. neo-japonicum using agroresidues may ensure a continuous supply of G. neo-japonicum for its medicinal use while ensuring the conservation of this rare species.

Matched MeSH terms: Dust
Fulltext IgE-binding residues analysis of the house dust mite allergen Der p 23

Pang SL, Matta SA, Sio YY, Ng YT, Say YH, Ng CL, et al.

Sci Rep, 2021 01 13;11(1):921.
PMID: 33441720 DOI: 10.1038/s41598-020-79820-y

House dust mites (HDMs) are one of the major causes of allergies in the world. The group 23 allergen, Der p 23, from Dermatophagoides pteronyssinus, is a major allergen amongst HDM-sensitized individuals. This study aims to determine the specific immunoglobulin E (sIgE) binding frequency and IgE-binding residues of recombinant Der p 23 (rDer p 23) allergen amongst a cohort of consecutive atopic individuals in a tropical region. We performed site-directed mutagenesis and carried out immuno-dot blot assays using 65 atopic sera. The immuno-dot blot assays results indicated that the two residues K44 and E46 which are located at the N-terminal region are the major IgE-binding residues. The rDerp-23 sIgE titers are strongly correlated to the number of IgE-binding residues for rDer p 23 (P

Matched MeSH terms: Dust/immunology
Fulltext Multi-Stage Feature Selection Based Intelligent Classifier for Classification of Incipient Stage Fire in Building

Andrew AM, Zakaria A, Mad Saad S, Md Shakaff AY

Sensors (Basel), 2016;16(1).
PMID: 26797617 DOI: 10.3390/s16010031

In this study, an early fire detection algorithm has been proposed based on low cost array sensing system, utilising off- the shelf gas sensors, dust particles and ambient sensors such as temperature and humidity sensor. The odour or "smellprint" emanated from various fire sources and building construction materials at early stage are measured. For this purpose, odour profile data from five common fire sources and three common building construction materials were used to develop the classification model. Normalised feature extractions of the smell print data were performed before subjected to prediction classifier. These features represent the odour signals in the time domain. The obtained features undergo the proposed multi-stage feature selection technique and lastly, further reduced by Principal Component Analysis (PCA), a dimension reduction technique. The hybrid PCA-PNN based approach has been applied on different datasets from in-house developed system and the portable electronic nose unit. Experimental classification results show that the dimension reduction process performed by PCA has improved the classification accuracy and provided high reliability, regardless of ambient temperature and humidity variation, baseline sensor drift, the different gas concentration level and exposure towards different heating temperature range.

Matched MeSH terms: Dust
Fulltext Indoor microbiome, microbial and plant metabolites, chemical compounds, and asthma symptoms in junior high school students: a multicentre association study in Malaysia

Sun Y, Zhang M, Ou Z, Meng Y, Chen Y, Lin R, et al.

Eur Respir J, 2022 Nov;60(5).
PMID: 35618276 DOI: 10.1183/13993003.00260-2022

BACKGROUND: Indoor microbial exposure is associated with asthma, but the health effects of indoor metabolites and chemicals have not been comprehensively assessed.
METHODS: We collected classroom dust from 24 junior high schools in three geographically distanced areas in Malaysia (Johor Bahru, Terengganu and Penang), and conducted culture-independent high-throughput microbiome and untargeted metabolomics/chemical profiling.
RESULTS: 1290 students were surveyed for asthma symptoms (wheeze). In each centre, we found significant variation in the prevalence of wheeze among schools, which could be explained by personal characteristics and air pollutants. Large-scale microbial variations were observed between the three centres; the potential protective bacteria were mainly from phyla Actinobacteria in Johor Bahru, Cyanobacteria in Terengganu and Proteobacteria in Penang. In total, 2633 metabolites and chemicals were characterised. Many metabolites were enriched in low-wheeze schools, including plant secondary metabolites flavonoids/isoflavonoids (isoliquiritigenin, formononetin, astragalin), indole and derivatives (indole, serotonin, 1H-indole-3-carboxaldehyde), and others (biotin, chavicol). A neural network analysis showed that the indole derivatives were co-occurring with the potential protective microbial taxa, including Actinomycetospora, Fischerella and Truepera, suggesting these microorganisms may pose health effects by releasing indole metabolites. A few synthetic chemicals were enriched in high-wheeze schools, including pesticides (2(3H)-benzothiazolethione), fragrances (2-aminobenzoic acid, isovaleric acid), detergents and plastics (phthalic acid), and industrial materials (4,4-sulfonyldiphenol).
CONCLUSIONS: This is the first association study between high-throughput indoor chemical profiling and asthma symptoms. The consistent results from the three centres indicate that indoor metabolites/chemicals could be a better indicator than the indoor microbiome for environmental and health assessments, providing new insights for asthma prediction, prevention and control.

Matched MeSH terms: Dust/analysis

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