Displaying publications 2541 - 2560 of 10018 in total

Abstract:
Sort:
  1. Shehab ZN, Jamil NR, Aris AZ
    J Environ Manage, 2020 Nov 15;274:111141.
    PMID: 32818827 DOI: 10.1016/j.jenvman.2020.111141
    A simplified modelling approach for illustrating the fate of emerging pollutants can improve risk assessment of these chemicals. Once released into aquatic environments, these pollutants will interact with various substances including suspended particles, colloidal or nano particles, which will greatly influence their distribution and ultimate fate. Understanding these interactions in aquatic environments continues to be an important issue because of their possible risk. In this study, bisphenol A (BPA) in the water column of Bentong River, Malaysia, was investigated in both its soluble and colloidal phase. A spatially explicit hydrological model was established to illustrate the associated dispersion processes of colloidal-bound BPA. Modelling results demonstrated the significance of spatial detail in predicting hot spots or peak concentrations of colloidal-bound BPA in the sediment and water columns as well. The magnitude and setting of such spots were system based and depended mainly on flow conditions. The results highlighted the effects of colloidal particles' concentration and density on BPA's removal from the water column. It also demonstrated the tendency of colloidal particles to aggregate and the impact all these processes had on BPA's transport potential and fate in a river water. All scenarios showed that after 7.5-10 km mark BPA's concentration started to reach a steady state with very low concentrations which indicated that a downstream transport of colloidal-bound BPA was less likely due to minute BPA levels.
  2. Alafeef AK, Ariffin F, Zulkurnain M
    Foods, 2020 Aug 29;9(9).
    PMID: 32872507 DOI: 10.3390/foods9091197
    Selenium is an essential micronutrient with significant antioxidant activity promising in mitigating the formation of acrylamide during high-temperature roasting. In this study, green coffee beans pretreated with selenium (Se-coffee) were investigated on their selenium uptake, selenium retention in green and roasted beans, antioxidant activities, and formation of acrylamide during conventional and superheated steam roasting. Comparisons were made with positive (pretreated without selenium) and negative (untreated) controls. The acrylamide formation was significantly inhibited in Se-coffee (108.9-165.3 μg/kg) compared to the positive and negative controls by 73.9% and 52.8%, respectively. The reduction of acrylamide by superheated steam roasting only observed in the untreated coffee beans (negative control) by 32.4% parallel to the increase in its antioxidant activity. Selenium pretreatment significantly increased antioxidant activity of the roasted Se-coffee beans after roasting although soaking pretreatment significantly reduced antioxidant activity in the green beans. Acrylamide reduction in the roasted coffee beans strongly correlated with the change in antioxidant capacities after roasting (∆FRAP, 0.858; ∆DPPH, 0.836). The results indicate that the antioxidant properties of the organic selenium suppressed acrylamide formation during coffee roasting.
  3. Widihastuty, Tobing MC, Marheni, Kuswardani RA, Fudholi A
    J Insect Physiol, 2020 07 17;125:104089.
    PMID: 32687849 DOI: 10.1016/j.jinsphys.2020.104089
    Ants are social insects with some significant roles in the ecosystem, including acting as predators for various insect pests. Myopopone castanea ants is a predatorfor the larvae of Oryctes rhinoceros pest. The existence of a similar niche of life between M. castanea ants and O. rhinoceros larvae opens an excellent opportunity to utilize these ants as biological agents. The research was conducted to study some aspects biology of M. castanea so that later it can be applied to mass rearing of natural enemies in the laboratory. The study was conducted by maintaining 50 eggs of M. castanea ant. Then, the eggs placed on two pieces of decayed palm oil stem together with twenty individual worker ants and ten individual end instar larvae. It needs five replications for the experiment. The results showed that egg stadia length was 13.8 days. It found five instars within M. castanea ant larvae with varying lengths of each stage. It takes 17.2 days for worker ant pupae to go through stadia pupa and 17.9 days for female ant pupae. The survival rate of M. castanea ant life from eggs until imago is 56.4%, which means that from several groups of eggs laid by queen ants, only about half have succeeded in becoming ant imago.
  4. Loh SC, Thottathil GP, Othman AS
    Plant Physiol Biochem, 2016 Oct;107:45-55.
    PMID: 27236227 DOI: 10.1016/j.plaphy.2016.05.011
    The natural rubber of Para rubber tree, Hevea brasiliensis, is the main crop involved in industrial rubber production due to its superior quality. The Hevea bark is commercially exploited to obtain latex, which is produced from the articulated secondary laticifer. The laticifer is well defined in the aspect of morphology; however, only some genes associated with its development have been reported. We successfully induced secondary laticifer in the jasmonic acid (JA)-treated and linolenic acid (LA)-treated Hevea bark but secondary laticifer is not observed in the ethephon (ET)-treated and untreated Hevea bark. In this study, we analysed 27,195 gene models using NimbleGen microarrays based on the Hevea draft genome. 491 filtered differentially expressed (FDE) transcripts that are common to both JA- and LA-treated bark samples but not ET-treated bark samples were identified. In the Eukaryotic Orthologous Group (KOG) analysis, 491 FDE transcripts belong to different functional categories that reflect the diverse processes and pathways involved in laticifer differentiation. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) and KOG analysis, the profile of the FDE transcripts suggest that JA- and LA-treated bark samples have a sufficient molecular basis for secondary laticifer differentiation, especially regarding secondary metabolites metabolism. FDE genes in this category are from the cytochrome (CYP) P450 family, ATP-binding cassette (ABC) transporter family, short-chain dehydrogenase/reductase (SDR) family, or cinnamyl alcohol dehydrogenase (CAD) family. The data includes many genes involved in cell division, cell wall synthesis, and cell differentiation. The most abundant transcript in FDE list was SDR65C, reflecting its importance in laticifer differentiation. Using the Basic Local Alignment Search Tool (BLAST) as part of annotation and functional prediction, several characterised as well as uncharacterized transcription factors and genes were found in the dataset. Hence, the further characterization of these genes is necessary to unveil their role in laticifer differentiation. This study provides a platform for the further characterization and identification of the key genes involved in secondary laticifer differentiation.
  5. Tamadoni Jahromi S, Othman AS, Rosazlina R
    Biochem Genet, 2018 Aug 12.
    PMID: 30099639 DOI: 10.1007/s10528-018-9884-3
    There are two morphotypes of Penaeus semisulcatus described hitherto in the Persian Gulf, namely the banded and non-banded antennae morphotypes. In this study, we used morphometric measurements and two mitochondrial genes (16S rRNA and cytochrome oxidase subunit I-COI) to assess relationships between the two morphotypes of P. semisulcatus. Out of 25 morphological characters examined, 10 characters were found significantly different between the two morphotypes when tested against separate sexes or both sexes combined. Results from the 16S rRNA and COI sequence analysis of two morphotypes of P. semisulcatus morphotype showed up to 6% and 17% sequence divergence, respectively. The 16S rDNA and COI sequences of the non-banding morphotype were not only very different to those of the banding morphotype but was also very different to all other Penaeus species (i.e., P. monodon, P. merguiensis, and P. indicus) included in the study. Both parsimony and Neighbor-Joining trees based on 16S rDNA and COI sequences provide similar tree topology that clearly separated the two morphotypes into two distinct groups. Based on these findings, we propose the two morphotypes of P. semisulcatus to be relegated as two sympatric species.
  6. Zreaqat M, Hassan R, Halim AS
    Cleft Palate Craniofac J, 2009 May;46(3):326-30.
    PMID: 19642750 DOI: 10.1597/07-210.1
    To determine the treatment outcome based on dentoalveolar relationships among Malay children born with nonsyndromic complete unilateral cleft lip and palate (UCLP).
  7. Azmi AN, Tan SS, Mohamed R
    World J Gastroenterol, 2014 Sep 14;20(34):12045-55.
    PMID: 25232242 DOI: 10.3748/wjg.v20.i34.12045
    The natural history of chronic hepatitis B is characterized by different phases of infection, and patients may evolve from one phase to another or may revert to a previous phase. The hepatitis B e antigen (HBeAg)-negative form is the predominant infection worldwide, which consists of individuals with a range of viral replication and liver disease severity. Although alanine transaminase (ALT) remains the most accessible test available to clinicians for monitoring the liver disease status, further evaluations are required for some patients to assess if treatment is warranted. Guidance from practice guidelines together with thorough investigations and classifications of patients ensure recognition of who needs which level of care. This article aims to assist physicians in the assessment of HBeAg-negative individuals using liver biopsy or non-invasive tools such as hepatitis B s antigen quantification and transient elastography in addition to ALT and hepatitis B virus DNA, to identify who will remain stable, who will reactivate or at risk of disease progression hence will benefit from timely initiation of anti-viral therapy.
  8. Elyaskhil M, Shafai NAA, Mokhtar N
    Health Qual Life Outcomes, 2021 Mar 03;19(1):71.
    PMID: 33658030 DOI: 10.1186/s12955-021-01710-2
    BACKGROUND: The present study aims to determine the impact of malocclusion on oral health related quality of life (OHRQoL) among 13-16 years old Malay school children.

    METHODS: School children aged between 13 and 16 years old were randomly selected from a secondary school in Penang. Malay version of Oral Health Impact Profile-14 (OHIP-14) questionnaires were given to the subjects. This questionnaire has 14 questions with seven domains which are functional limitation, psychological discomfort, physical pain, physical disability, psychological and social disability, and handicap. Index of orthodontic treatment need dental health component was used to assess the orthodontic treatment need. Overjet (reversed overjet), open bite, overbite, cross bite, impeded eruption, crowding, defects of cleft lip and palate, Class II and Class III buccal occlusion, present of supernumerary and hypodontia were assessed.

    RESULTS: 255 students participated in this study. Mean score and standard deviation for OHIP-14 were 8.64 (± 7.32) for males and 11.05 (± 9.41) for females respectively. There was statistically significant difference in mean score of OHIP-14 between male and female (p = 0.023). A weak positive correlation was found between malocclusion severity and OHRQoL (r = 0.186; p 

  9. Mohd Yusop AY, Xiao L, Fu S
    Drug Test Anal, 2021 May;13(5):965-976.
    PMID: 32441056 DOI: 10.1002/dta.2861
    The lucrative market of herbal remedies spurs rampant adulteration, particularly with pharmaceutical drugs and their unapproved analogues. A comprehensive screening strategy is, therefore, warranted to detect these adulterants and, accordingly, to safeguard public health. This study uses the data-dependent acquisition of liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) to screen phosphodiesterase 5 (PDE5) inhibitors in herbal remedies using suspected-target and non-targeted strategies. For the suspected-target screening, we used a library comprising 95 PDE5 inhibitors. For the non-targeted screening, we adopted top-down and bottom-up approaches to flag novel PDE5 inhibitor analogues based on common fragmentation patterns. LC-QTOF-MS was optimised and validated for capsule and tablet dosage forms using 23 target analytes, selected to represent different groups of PDE5 inhibitors. The method exhibited excellent specificity and linearity with limit of detection and limit of quantification of <40 and 80 ng/mL, respectively. The accuracy ranged from 79.0% to 124.7% with a precision of <14.9% relative standard deviation. The modified, quick, easy, cheap, effective, rugged, and safe extraction provided insignificant matrix effect within -9.1%-8.0% and satisfactory extraction recovery of 71.5%-105.8%. These strategies were used to screen 52 herbal remedy samples that claimed to enhance male sexual performance. The suspected-target screening resulted in 33 positive samples, revealing 10 target analytes and 2 suspected analytes. Systematic MS and tandem MS interrogations using the non-targeted screening returned insignificant signals, indicating the absence of potentially novel analogues. The target analytes were quantified from 0.03 to 121.31 mg per dose of each sample. The proposed strategies ensure that all PDE5 inhibitors are comprehensively screened, providing a useful tool to curb the widespread adulteration of herbal remedies.
  10. Mohd Yusop AY, Xiao L, Fu S
    Drug Test Anal, 2021 May;13(5):953-964.
    PMID: 32959983 DOI: 10.1002/dta.2926
    The surge in the consumption of food products containing herbal aphrodisiacs has driven their widespread adulteration. A rapid screening strategy is, therefore, warranted to curb this problem. This study established an enzyme inhibition assay to screen phosphodiesterase 5 (PDE5) inhibitors as adulterants in selected food products. Fluorescein-labelled cyclic-3',5'-guanosine monophosphate was utilised as substrates for the PDE5A1 enzyme, aided by the presence of nanoparticle phosphate-binding beads on their fluorescence polarisation. The sample preparation was optimised to improve the enzyme inhibition efficiency and applied to calculate the threshold values of six blank food matrices. The assay was validated using sildenafil, producing an IC50 of 4.2 nM. The applicability of the assay procedure was demonstrated by screening 55 distinct food samples. The results were subsequently verified using confirmatory liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analysis. Altogether, 49 samples inhibited the PDE5 enzyme above the threshold values (75.7%-105.5%) and were registered as potentially adulterated samples. The remaining six samples were marked as nonadulterated with percentage inhibition below the threshold values (-3.3%-18.2%). The LC-HRMS analysis agreed with the assay results for all food products except for the instant coffee premix (ICP) samples. False-positive results were obtained for the ICP samples at 32% (8/25), due to possible PDE5 inhibition by caffeine. Contrarily, all other food samples were found to produce 0% (0/30) false-positive or false-negative results. The broad-based assay, established via a simple mix-incubate-read format, exhibited promising potential for high-throughput screening of PDE5 inhibitors in various food products, except those with naturally occurring phosphodiesterase inhibitors such as caffeine.
  11. Nur Amirah Fadzlena Md Fadzli, Wan Syazehan Ruznan, Suraya Ahmad Suhaimi, Mohd Azlin Mohd Nor, Suhaidi Ariffin, Mohd Rozi Ahmad, et al.
    MyJurnal
    Of late, dyeing fabrics with natural dyes have become an attraction because of its eco-friendly and less threatening disposition towards humankind. In the textile colouration industry, natural dyes play an important role because of the need for replacement synthetic dyes which have a great deal of tension with the environmental issues. This study focuses on the colour shade, colour coordinates, and fastness properties of dyed silk fabric from tagetes erecta (Mexican Marigold flower) using the water boiling extraction method. The dyeing was carried out using lemon juice as a natural mordant through the simultaneous mordanting method, using two different dyeing methods: infrared (IR) dyeing and exhaustion dyeing. The shades produced for exhaustion dyed fabric is light-yellow compared to the IR dyed fabric, which is medium-light yellow. These shades were confirmed with the CIELAB colour coordinates, L*a*b* values. The colourfastness to washing, perspiration, rubbing, and light of the fabrics were conducted to investigate the performance of the dye and mordant on the dyed silk fabrics. The colourfastness properties of the dyed silk fabric using infrared (IR) dyeing technique have better performance than using exhaustion dyeing technique.
  12. Pin LC, Teen LP, Ahmad A, Usup G
    Mar Biotechnol (NY), 2001 May;3(3):246-55.
    PMID: 14961362
    The genus Ostreopsis is an important component of benthic and epiphytic dinoflagellate assemblages in coral reefs and seaweed beds of Malaysia. Members of the species may produce toxins that contribute to ciguatera fish poisoning. In this study, two species have been isolated and cultured, Ostreopsis ovata and Ostreopsis lenticularis. Analyses of the 5.8S subunit and internal transcribed spacer regions ITS1 and ITS2 of the ribosomal RNA gene sequences of these two species showed that they are separate species, consistent with morphological designations. The nucleotide sequences of the 5.8S subunit and ITS1 and ITS2 regions of the rRNA gene were also used to evaluate the interpopulation and intrapopulation genetic diversity of O. ovata found in Malaysian waters. Results showed a low level of sequence divergence within populations. At the interpopulation level, the rRNA gene sequence distinguished two groups of genetically distinct strains, representative of a Malacca Straits group (isolates from Port Dickson) and a South China Sea group (isolates from Pulau Redang and Kota Kinabalu). Part of the sequences in the ITS regions may be useful in the design of oligonucleotide probes specific for each group. Results from this study show that the ITS regions can be used as genetic markers for taxonomic, biogeographic, and fine-scale population studies of this species.
  13. Fatahyah, Yahya, Aqilah, Yusoff, Sarjit Singh, Darshan Singh, Ahmad Tarmizi, Talib, Abdul Hakim, Mohad, Nur Ayuni, Mohd Isa, et al.
    MyJurnal
    The research was aimed to study the relationship between attachment styles and marital quality between spouses. A total number of 52 spouses representing teachers from Sekolah Menengah Agama Daeratul Ma'arifil Wataniah 1 (SMA DMW 1), in Peninsular Malaysia's northwest coast, participated in this study. There were two sets of questionnaires used in this study: Experience in Close Relationship (ECR) and Marital Adjustment Test (MAT). The results showed that there was a significant relationship between attachment styles and spouses' styles. However, there is no relationship between marital satisfaction among spouses, and there is also no relationship between attachment styles and marital satisfaction among spouses. Future research is suggested to enhance the research by moving beyond self-report instruments to develop alternative methods of assessment as some of the questions should be more specifically suitable in Malaysian culture.
  14. Fatahyah, Yahya, Mohd Imamuddin, Nahar, Ahmad Tarmizi, Talib, Sarjit Singh, Darshan Singh, Abdul Hakim, Mohad, Nur Ayuni, Mohd Isa, et al.
    MyJurnal
    This study aims to identify parental attachment's effects on trainee counsellors' personality traits in the Universiti of Malaysia Sarawak UNIMAS. This research adopted a correlational research design. The respondents were 209 trainee counsellors from the Counselling Program, Universiti Malaysia Sarawak UNIMAS. Two questionnaires were used in this study: The Inventory of Parents and Peer Attachment (IPPA) and the Big Five Personality. The findings indicated a significant relationship between Parents Communication, Attachment and Extraversion and the Agreeableness Trait of Personality. It also showed a significant relationship between Parents Communication Attachment and Extraversion, Agreeableness and Conscientiousness. We also found a significant relationship between Parents' Alienation Attachment and Conscientiousness, Neuroticism and Openness. The study informs society about the need to increase awareness about the importance of knowing attachment styles and personality traits as both impact individuals' lives.
  15. Meylani V, Sembiring L, Fudholi A, Wibawa T
    Microb Pathog, 2021 Sep;158:105075.
    PMID: 34224845 DOI: 10.1016/j.micpath.2021.105075
    Gene expression of SAP 4-6 based on the detection of mRNA was observed in Candida albicans isolates from HIV-positive patients with oral candidiasis and commensal from healthy individuals. The species of C. albicans strains were selectively isolated from both sources using CHROMagar Chromogenic Media. The obtained isolates were then induced to express SAP 4-6 using SAP 4-6 gene inducer media. Analysis of gene expression was performed on a molecular basis using the RT-PCR method. Molecular analysis of gene expression showed that the isolates CH3 from HIV-positive patients with oral candidiasis could express SAP 4-6 gene, while commensal isolates from healthy people could not. Based on the results of this study, it could be concluded that, in terms of molecular detection, only isolates from HIV-positive patients (CH3) could express their SAP 4-6 gene.
  16. Zubir MHM, Zaini MAA
    Sci Rep, 2020 08 20;10(1):14050.
    PMID: 32820209 DOI: 10.1038/s41598-020-71034-6
    This work is aimed at evaluating the conversion of Pterocarpus indicus twigs into activated carbon via composite chemical activation for methylene blue and congo red dyes adsorption. The activated carbons were prepared by single-step chemical activation using zinc chloride and/or phosphoric acid at different mass impregnation ratios at 600 °C for 90 min. The activated carbons were characterized for textural properties and surface chemistry. The batch adsorption was investigated at different concentrations (5-1,000 mg/L), contact times (2-540 min) and temperatures (30-60 °C). Phosphoric acid-activated twigs carbon showed a high surface area of 1,445 m2/g with maximum methylene blue adsorption capacity of 438 mg/g. On the other hand, a composite-activated carbon yields a 217 mg/g of congo red removal. The adsorption data for both dyes fitted well with Langmuir and pseudo-second-order kinetics models, indicating the predominance of chemical adsorption through monolayer coverage of dye molecules on the homogenous surface of activated carbon. The thermodynamics properties of dye adsorption onto twigs-derived activated carbons indicated that the process is endothermic, spontaneous and favourable at high temperature. Overall, activated carbons derived from Pterocarpus indicus twigs could be effectively used for dye wastewater treatment.
  17. Mohd Ngesom AM, Ahmad Razi A, Azizan NS, Wasi Ahmad N, Md Lasim A, Liang Y, et al.
    Parasit Vectors, 2021 Aug 18;14(1):413.
    PMID: 34407881 DOI: 10.1186/s13071-021-04918-9
    BACKGROUND: Dengue is a significant public health issue that is caused by Aedes spp. mosquitoes. The current vector control methods are unable to effectively reduce Aedes populations and thus fail to decrease dengue transmission. Hence, there is an urgent need for new tools and strategies to reduce dengue transmission in a wide range of settings. In this study, the Mosquito Home System (MHS) and Mosquito Home Aqua (MHAQ) formulations were assessed as commercial autodissemination traps in laboratory and small-scale field trials.

    METHOD: Multiple series of laboratory and small-scale field trials were performed to assess the efficacy of MHS and MHAQ exposed to Ae. aegypti. In the laboratory trials, various parameters such as fecundity, fertility, wing size, oviposition preferences, residual effects, and MHAQ transference to other containers through controlled experiments were tested. For small-scale field trials, the efficacy of the MHS and MHAQ approaches was determined to ascertain whether wild mosquitoes could transfer the MHAQ formulation from MHS stations to ovitraps.

    RESULTS: The data revealed that Ae. aegypti was highly susceptible to low concentrations of MHAQ formulations and had a residual effect of up to 3 months, with MHAQ exposure affecting fecundity, fertility, and mosquito wing size. In the oviposition studies, gravid females strongly preferred the hay infusion compared to tap water and MHAQ during egg-laying in the laboratory. Nevertheless, the use of commercial MHAQ by MHS was highly attractive in field settings compared to conventional ovitraps among local Aedes spp. mosquitoes. In addition, MHAQ horizontal transfer activities in the laboratory and small-scale field trials were demonstrated through larval bioassays. These findings demonstrated the potential of MHAQ to be transferred to new containers in each study site.

    CONCLUSION: This study provided proof of principle for the autodissemination of MHAQ. Through further refinement, this technique and device could become an effective oviposition trap and offer an alternative preventive tool for vector control management.

  18. Mohd Yusop AY, Xiao L, Fu S
    Forensic Sci Int, 2021 May;322:110748.
    PMID: 33711768 DOI: 10.1016/j.forsciint.2021.110748
    The presence of erectile dysfunction (ED) drugs in adulterated dietary supplements, mainly in pharmaceutical dosage forms, is frequently addressed in the literature. Little attention is given to food products despite their increasing adulteration trend. To address this knowledge gap targeted, suspected-target, and non-targeted strategies were utilised to analyse ED drugs and their analogues in powdered drink mix (PDM), honey, jelly, hard candy, and sugar-coated chewing gum using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). The method was optimised and validated using 23 target analytes, representing different ED drugs with structural similarities. The modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction exhibited insignificant matrix effect (ME) within - 9.2-8.8% and provided complete coverage of target analytes with acceptable extraction recovery (RE) within 75.5-123.9%, except for carbodenafil in the PDM matrix. Based on the ME and RE performance, the analytical method was validated to analyse 25 food samples that claimed to enhance male sexual performance. The method exhibited good specificity and linearity with a limit of detection within 10-70 ng/mL and limit of quantification of 80 ng/mL. Similarly, the accuracy and precision were satisfactory within 77.4-122.0% and
  19. Nair N, Ng CG, Sulaiman AH
    Asian J Psychiatr, 2021 Feb;56:102548.
    PMID: 33454562 DOI: 10.1016/j.ajp.2021.102548
    The mental wellbeing of doctors is becoming an increasing concern in the world today. In Malaysia, residency is a challenging period in a doctor's life, with many changes professionally and possibly in their personal lives as well. This study aims to determine the prevalence of depressive symptoms and the socio-demographic correlates among residents in a tertiary training hospital in Malaysia. It is a cross sectional study and all residents were approached to participate in the study. The instruments used were a socio-demographic questionnaire and the Patient Health Questionnaire 9 (PHQ-9). Chi-square test was used to explore the association between the socio-demographic correlates, and those that were found to have significant associations were further tested using multivariate logistic regression. The prevalence of depression among residents was 25.1 %. Longer working hours, missing meals, and working in Department of Surgery and Department of Anaesthesia was significantly positively associated while having protected study time, CME/lectures, leisure/hobbies and exercise were negatively associated with depression. The Department of Rehabilitation Medicine had a significantly negative association with depression. After logistic regression, longer working hours and a lack of protected study time was significantly associated with depression in the respective departments. In summary, the prevalence of depression among residents is high and is associated with longer working hours, missing meals and a lack of protected study time are significantly associated with depression. Remedial steps should be taken to improve the mental health among residents.
  20. Razali MH, Noor AFM, Yusoff M
    J Nanosci Nanotechnol, 2020 02 01;20(2):965-972.
    PMID: 31383093 DOI: 10.1166/jnn.2020.16944
    In this study, a series of copper-ion-doped titanium dioxide (Cu-ion-doped TiO₂) nanotubes (NTs) were synthesized via a hydrothermal method by the concentration variation of doped Cu ions (0.00, 0.50, 1.00, 2.50, and 5.00 mmol). In addition, the samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), nitrogen gas adsorption measurements, and ultraviolet-visible (UV-Vis) diffuse-reflectance spectroscopy. The photocatalytic activity of the Cu-iondoped TiO₂ NTs was investigated for the degradation of methyl orange (MO) under sunlight. The results obtained from the structural and morphological studies revealed that, at low concentrations of Cu-doped TiO₂ NTs, Cu is incorporated into the interstitial positions of the TiO₂ lattice, affording a new phase of TiO₂ (hexagonal) instead of the anatase TiO₂ (tetragonal) observed for undoped TiO₂ NTs. EDX analysis confirmed the presence of Cu in the TiO₂-based photocatalyst. All of the investigated samples exhibited a hollow fibrous-like structure, indicative of an NT morphology. The inner and outer diameters of the NTs were 4 nm and 10 nm, respectively. The photocatalysts exhibited a large surface area due to the NT morphology and a type IV isotherm and H3 hysteresis, corresponding to the mesopores and slit-shaped pores. The Cu-ion-doped TiO₂ NTs were excited by sunlight because of their low bandgap energy; and after the incorporation of Cu ions into the interstitial positions of the TiO₂ lattice, the NTs exhibited high visible-light activity owing to the low bandgap.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links