Study on Semiconductor Properties of Acetylide-Thiourea Fabricated onto Interdigitated Electrodes (Ides) Platform Towards Application In Gas Sensing Technology

In the past few decades, the unique properties of acetylide and thiourea moieties individually have attracted great attention from researchers in various fields to be developed in numerous applications in advanced materials technology, especially as active layer in gas sensing devices. Acetylide and thiourea molecular system provides a wide range of electronic properties as they possess rigid π-systems in their designated structures. In this study, a derivative of acetylide-thiourea featuring N-(4[4-aminophenyl] ethynyl benzonitrile)-N’-(4-ethyl benzoyl)thiourea (TCN) has been synthesised having general formula of ArC(O)NHC(S)NHC≡C)Ar adopting the system of D-π-A for significant development of conductive materials. The derivative consists of donating substituent which has been characterised by typical spectroscopic techniques namely infrared spectroscopy, UV-visible spectroscopy, and 1H and 13C Nuclear Magnetic Resonance. In turn, TCN was deposited onto interdigitated electrode (IDE) for the measurement of thin-film resistance. The resistance values of synthesised compound is due to the effect of donating substituent attached to the acetylide-thiourea, which indeed altered the conductivity performances of fabricated IDE substrate. In fact, the theoretical calculation also was carried out using Gaussian 09 to evaluate the relationship between experimental and theoretical analyses of acetylide-thiourea semiconductor properties in term of energy band gap and sensing response towards selected analyte

School indoor air pollutants: In relation to allergy and respiratory symptoms among school children in urban areas

Indoor air pollutants affect children’s health and previous research mostly focuses on respiratory and allergic diseases. However, little is known about the risks among school children in East Malaysia. Therefore, we studied associations between school children’s respiratory and allergic symptoms and indoor air pollutants in schools in Sabah, Malaysia. We randomly selected 332 school children (14 years old) from 24 classrooms in 6 secondary schools in Kota Kinabalu, Sabah. Information on personal characteristics, respiratory and allergic symptoms were gathered by using a standard questionnaire. The skin prick test was used to characterize their atopy. In each classroom, the indoor concentrations of particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2 ), formaldehyde, total volatile organic compounds (TVOC), carbon dioxide (CO2 ) temperature and relative humidity were monitored. Overall, 11.7% reported doctor-diagnosed asthma, 14.8% wheezing, 17.5% day-time breathlessness, 37.0% breathlessness after exercise, 13.0% breathlessness at night-time, 55.1% rhinitis and 10.8% skin allergic in the last 12 months. Regression analysis showed that the onset of wheezing was common in doctor diagnosed asthma (OR= 8.29, 95% CI= 3.70-16.10) and with parental asthma/allergy (OR= 2.13, 95% CI= 1.10-4.15), and associated with concentrations of NO2 (OR= 1.03, 95% CI= 1.01-1.21) and CO2 (OR= 1.01, 95% CI= 1.01-1.11). Day-time breathlessness was associated with indoor NO2 (OR=1.02, 95% CI= 1.02-1.35) and TVOC (OR= 1.30, 95% CI= 1.10-1.52). The indoor concentrations of NO2 , CO2 , TVOC and PM2.5 as well as parental asthma/allergy, and parental smoking were risk factors to the health outcome of respiratory and allergic symptoms

Indoor air pollutants in schools and their relationship with airway inflammation, respiratory and allergic symptoms among school children in Hulu Langat, Malaysia

Many recent reviews and research have found that interaction exposure to indoor pollutants and a spectrum of allergens can cause allergic reactions, raise the likelihood of developing asthma and exacerbate existing asthma. This study aimed to investigate the relationships between indoor air pollutants, the diversity of fungal relative abundance in the settled dust samples, respiratory and allergic symptoms, and airway inflammation levels (FeNO levels and expression of adhesion molecules) among school children in urban and suburban areas. This comparative cross-sectional study was conducted in the Hulu Langat District, Selangor, Malaysia and involved eight secondary schools located in urban and suburban areas respectively. The indoor air concentration of NO2, CO2, PM10, PM2.5, formaldehyde, as well as temperature and relative humidity were measured using active and passive sampling techniques from 4 classrooms in each school. The settled dust samples were collected inside the classrooms using a vacuum cleaner and further analysed using metagenomic techniques to characterise the fungi composition. The personal and health information were collected among 470 school children aged of 14 years old, who were randomly selected from the schools and classrooms aforementioned, using a questionnaire adapted from the International Study of Asthma and Allergies in Childhood (ISAAC) and the European Community Respiratory Heath Survey (ECRHS). Then, FeNO levels were measured, induced sputum samples were collected and IgE-mediated allergy (allergic skin tests) were conducted concurrently with environmental monitoring. Sputum samples were further analysed to investigate the expression of CD11b, CD35, CD63 and CD66b on both eosinophil and neutrophil using flow cytometry techniques. The 2-level logistic regression (school and children) analysis, general linear regression, and logistic regression with complex sampling were used determining the influencing factors. The results showed that temperature, NO2, PM10, PM2.5 and formaldehyde concentrations in schools located in the urban areas were significantly higher than in the suburban areas. However, all indoor parameters for both areas were below the local and international recommendation guidelines, except for formaldehyde. In the profile analysis, the fungal diversity levels were significantly abundant in suburban samples than the urban, in which Aspergillus clavatus (37.8%) and Hyphoderma multicystidium (13.6%) were dominant. Moreover, regression analysis revealed that the manifestations of wheezing, eczema, rhinitis and nasal infection were associated with PM10 (OR = 1.08, 95% CI = 1.01 - 1.17), CO2 (OR = 1.03, 95% CI = 1.01 - 1.05), formaldehyde (OR = 1.10, 95% CI = 1.03 - 1.17), the relative abundance of Xenasmatella ardosiaca (OR = 1.40, 95% CI = 1.09 - 1.81) and Cladosporium halotolerans (OR = 27.43, 95% CI = 2.21 - 340.87), and a few indoor home environment factors. This study also found that the expression profile of CD11b, CD35, CD63 and CD66b on eosinophil and neutrophil cells were influenced by indoor pollutants and several fungal taxa (Trichosporon asahii (OR = 4.01, 95% CI = 1.02 - 16.45), Hannaella pagnoccae (OR = 3.33, 95% CI = 1.05 - 10.55), Hazslinszkyomyces aloes (OR = 7.58, 95% CI = 9.80 - 58.76), Papiliotrema bandonii (OR = 3.78, 95% CI = 1.77 - 8.06), Candida parapsilosis (OR = 1.94, 95% CI = 2.12-18.31)) after controlling for confounders. Overall, this study demonstrated that many rare and unculturable fungi taxa together with exposure to indoor air pollutants were potentially attributable to an increase in the airway inflammation reactions and the manifestation of asthma development among school children. The novelty of this study lies in the inclusion of rare and unculturable fungi taxa data characterised from metagenomics protocols, and multi-dimensional expression data of adhesion molecules (CD11b, CD35, CD63 and CD66b) analysed using flow cytometry, whilst simultaneously evaluated with indoor pollutant parameters using a regression for complex samples to enhance health risk assessment of these school children. In this context, future endeavors to determine the prolonged effects and patterns of inflammatory biomarkers in relation to indoor air pollutants are warranted

Evaluation of the relationship between fractional exhaled nitric oxide (FeNO) with indoor PM10, PM2.5 and NO2 in suburban and urban schools

Numerous epidemiological studies have evaluated the association of fractional exhaled nitric oxide (FeNO) and indoor air pollutants, but limited information available of the risks between schools located in suburban and urban areas. We therefore investigated the association of FeNO levels with indoor particulate matter (PM10 and PM2.5), and nitrogen dioxide (NO2) exposure in suburban and urban school areas. A comparative cross-sectional study was undertaken among secondary school students in eight schools located in the suburban and urban areas in the district of Hulu Langat, Selangor, Malaysia. A total of 470 school children (aged 14 years old) were randomly selected, their FeNO levels were measured, and allergic skin prick tests were conducted. The PM2.5, PM10, NO2, and carbon dioxide (CO2), temperature, and relative humidity were measured inside the classrooms. We found that the median of FeNO in the school children from urban areas (22.0 ppb, IQR = 32.0) were slightly higher as compared to the suburban group (19.5 ppb, IQR = 24.0). After adjustment of potential confounders, the two-level hierarchical multiple logistic regression models showed that the concentrations of PM2.5 were significantly associated with elevated of FeNO (>20 ppb) in school children from suburban (OR = 1.42, 95% CI = 1.17–1.72) and urban (OR = 1.30, 95% CI = 1.10–1.91) areas. Despite the concentrations of NO2 being below the local and international recommendation guidelines, NO2 was found to be significantly associated with the elevated FeNO levels among school children from suburban areas (OR = 1.11, 95% CI = 1.06–1.17). The findings of this study support the evidence of indoor pollutants in the school micro-environment associated with FeNO levels among school children from suburban and urban areas

The Impact of Exposure to Indoor Pollutants on Allergy and Lung Inflammation among School Children in Selangor, Malaysia : An Evaluation Using Factor Analysis

A cross-sectional study of 470, 14-year-old students from 8 secondary schools located in sub-urban and urban areas in Hulu Langat district, Selangor, Malaysia was undertaken to determine the impact of atmospheric indoor air pollutants on atopy, asthma, respiratory symptoms and lung inflammation among school children. The students were surveyed using ISAAC and ECRHS questionnaires, their FeNO levels were measured and allergic skin prick tests were conducted. Active and passive sampling was used to measure the classroom indoor air concentration of NO2, CO2, formaldehyde, PM10, PM2.5, temperature and relative humidity. Linear mixed model, two-levels multiple logistic regression, PCA and SPC were applied to determine the complex relationship between respiratory symptoms, personal factors, FeNO levels and atmospheric indoor pollutants. 20.6% of students reported daytime breathlessness and 55.5% reported having rhinitis in the last 12 months. Atopy was prevalent in 57.7% of students, with predominant sensitization to Derp1 (51.9%) and Derf1 (47.9%) among doctor's diagnosed asthmatic students. Indoor air pollutants in urban area schools were significantly higher than those in sub-urban areas (p < 0.001). There was a significant association between exposure to PM10 (OR = 2.66, 95% CI: 1.33-5.30) with skin allergy symptoms in the past 12 months. The PCA suggested that the most prominent factor associated with increasing FeNO levels was PM10, with 73.5% of the variation. SPC predicted the pattern of FeNO at an upper confidence limit (UCL) of 104.21 ppb with increasing PM10 concentration in the classroom (UCL = 40.23 mu g m(-3)). Exposure to PM10 and PM2.5 significantly influenced the inflammation of the school children's lungs. Moreover, there were associations between self-reported wheezing, daytime and nocturnal attack of breathlessness with doctor's diagnosed asthma among school children

Fungi composition in settled dust associated with fractional exhaled nitric oxide in school children with asthma

Fungi exposure has been significantly linked to respiratory illness. However, numerous fungi taxa that are potentially allergenic still undocumented and leave a barrier to establishing a clear connection between exposure and health risks. This study aimed to evaluate the association of fungi composition in settled dust with fractional exhaled nitric oxide (FeNO) levels among school children with doctor-diagnosed asthma. A cross-sectional study was undertaken among secondary school students in eight schools in the urban area of Hulu Langat, Selangor, Malaysia. A total of 470 school children (aged 14 years old) were randomly selected and their FeNO levels were measured and allergic skin prick tests were conducted. The settled dust samples were collected and analysed by using metagenomic technique to determine the fungi composition. The general linear regression with complex sampling was employed to determine the interrelationship. In total, 2645 fungal operational taxonomic units (OTUs) were characterised from the sequencing process which belongs to Ascomycota (60.7 %), Basidiomycota (36.4 %), Glomeromycota (2.9 %) and Chytridiomycota (0.04 %). The top five mostly abundance in all dust samples were Aspergillus clavatus (27.2 %), followed by Hyphoderma multicystidium (12.2 %), Verrucoconiothyrium prosopidis (9.4 %), Ganoderma tuberculosum (9.2 %), and Heterochaete shearii (7.2 %). The regression results indicated that A. clavatus, Brycekendrickomyces acaciae, Candida parapsilosis, Hazslinszkyomyces aloes, H. multicystidium, H. shearii, Starmerella meliponinorum, V. prosopidis were associated in increased of FeNO levels among the asthmatic group at 0.992 ppb (95 % CI = 0.34-1.68), 2.887 ppb (95 % CI = 2.09-3.76), 0.809 ppb (95 % CI = 0.14-1.49), 0.647 ppb (95 % CI = 0.36-0.94), 1.442 ppb (95 % CI = 0.29-2.61), 1.757 ppb (95 % CI = 0.59-2.87), 1.092 ppb (95 % CI = 0.43-1.75) and 1.088 ppb (95 % CI = 0.51-1.62), respectively. To our knowledge, this is a new finding. The findings pointed out that metagenomics profiling of fungi could enhance our understanding of a complex interrelation between rare and unculturable fungi with airway inflammation

Metagenomic characterization of indoor dust fungal associated with allergy and lung inflammation among school children

The exposure of school children to indoor air pollutants has increased allergy and respiratory diseases. The objective of this study were to determine the toxicodynamic interaction of indoor pollutants exposure, biological and chemical with expression of adhesion molecules on eosinophil and neutrophil. A self-administered questionnaire, allergy skin test, and fractional exhaled nitric oxide (FeNO) analyser were used to collect information on health status, sensitization to allergens and respiratory inflammation, respectively among school children at age of 14 years. The sputum induced were analysed to determine the expression of CD11b, CD35, CD63 and CD66b on eosinophil and neutrophil by using flow cytometry technique. The particulate matter (PM2.5 and PM10), NO2, CO2, and formaldehyde, temperature, and relative humidity were measured inside the classrooms. The fungal DNA were extracted from settled dust collected from classrooms and evaluated using metagenomic techniques. We applied chemometric and regression in statistical analysis. A total of 1869 unique of operational taxonomic units (OTUs) of fungi were identified with dominated at genus level by Aspergillus (15.8%), Verrucoconiothyrium (5.5%), and Ganoderma (4.6%). Chemometric and regression results revealed that relative abundance of T. asahii were associated with down regulation of CD66b expressed on eosinophil, and elevation of FeNO levels in predicting asthmatic children with model accuracy of 63.6%. Meanwhile, upregulation of CD11b expressed on eosinophil were associated with relative abundance of A. clavatus and regulated by PM2.5. There were significant association of P. bandonii with upregulation of CD63 expressed on neutrophil and exposure to NO2. Our findings indicate that exposure to PM2.5, NO2, T. asahii, P.bandonii and A.clavatus are likely interrelated with upregulation of activation and degranulation markers on both eosinophil and neutrophil