Displaying publications 1 - 20 of 36 in total

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  1. Esa R, Hashim NA, Ayob Y, Yusof ZY
    BMC Oral Health, 2015 Mar 10;15:28.
    PMID: 25886943 DOI: 10.1186/s12903-015-0013-y
    BACKGROUND: To evaluate the psychometric properties of the faces version of the Modified Child Dental Anxiety Scale (MCDASf) Malay version in 5-6 and 9-12 year-old children.
    METHODS: The MCDASf was cross culturally adapted from English into Malay. The Malay version was tested for reliability and validity in 3 studies. In the Study 1, to determine test-retest reliability of MCDASf scale, 166 preschool children aged 5-6 years were asked to rank orders five cartoons faces depicting emotions from 'very happy' to 'very sad' faces on two separate occasions 3 weeks apart. A total of 87 other 5-6 year-old children completed the Malay-MCDASf on two separate occasions 3 weeks apart to determine test-retest reliability for Study 2. In study 3, 239 schoolchildren aged 9-12 years completed the Malay-MCDASf and the Malay-Dental Subscale of the Children Fear Survey Schedule (CFSS-DS) at the same sitting to determine the criterion and construct validity.
    RESULTS: In study 1, Kendall W test showed a high degree of concordance in ranking the cartoon faces picture cards on each of the 2 occasions (time 1, W = 0.955 and time 2, W = 0.954). The Malay-MCDASf demonstrated moderate test-retest reliability (Intraclass correlation coefficient = 0.63, p <0.001) and acceptable internal consistency for all the 6 items (Cronbach's alpha = 0.77) and 8 items (Cronbach's alpha = 0.73). The highest MCDASf scores were observed for the items 'injection in the gum' and 'tooth taken out' for both age groups. The MCDASf significantly correlated with the CFSS-DS (Pearson r = 0.67, p < 0.001).
    CONCLUSIONS: These psychometric findings support for the inclusion of a cartoon faces rating scale to assess child dental anxiety and the Malay-MCDASf is a reliable and valid measure of dental anxiety in 5-12 year-old children.
  2. Dieng H, Hassan RB, Hassan AA, Ghani IA, Abang FB, Satho T, et al.
    Acta Trop, 2015 May;145:68-78.
    PMID: 25617636 DOI: 10.1016/j.actatropica.2015.01.004
    Even with continuous vector control, dengue is still a growing threat to public health in Southeast Asia. Main causes comprise difficulties in identifying productive breeding sites and inappropriate targeted chemical interventions. In this region, rural families keep live birds in backyards and dengue mosquitoes have been reported in containers in the cages. To focus on this particular breeding site, we examined the capacity of bird fecal matter (BFM) from the spotted dove, to support Aedes albopictus larval growth. The impact of BFM larval uptake on some adult fitness traits influencing vectorial capacity was also investigated. In serial bioassays involving a high and low larval density (HD and LD), BFM and larval standard food (LSF) affected differently larval development. At HD, development was longer in the BFM environment. There were no appreciable mortality differences between the two treatments, which resulted in similar pupation and adult emergence successes. BFM treatment produced a better gender balance. There were comparable levels of blood uptake and egg production in BFM and LSF females at LD; that was not the case for the HD one, which resulted in bigger adults. BFM and LSF females displayed equivalent lifespans; in males, this parameter was shorter in those derived from the BFM/LD treatment. Taken together these results suggest that bird defecations successfully support the development of Ae. albopictus. Due to their cryptic aspects, containers used to supply water to encaged birds may not have been targeted by chemical interventions.
  3. Hashim NA, Ariaratnam S, Salleh MR, Said MA, Sulaiman AH
    East Asian Arch Psychiatry, 2016 Jun;26(2):77-82.
    PMID: 27377489
    OBJECTIVES: To determine the prevalence of major depressive disorder and its association with socio-demographic and clinical factors in patients with type 2 diabetes mellitus.

    METHODS: This was a cross-sectional study of patients with type 2 diabetes mellitus who attended the hospital-based primary care clinics at the University Malaya Medical Centre, Kuala Lumpur, Malaysia. The patients were interviewed using the Mini-International Neuropsychiatric Interview to diagnose depression based on the DSM-IV criteria. The socio-demographic and clinical data were obtained by interviewing the patients and subsequently verified against their respective case notes.

    RESULTS: A total of 204 patients were recruited. The prevalence of major depressive disorder was 15.7%. Major depressive disorder was significantly associated with younger age of patients (mean ± standard deviation, 57.8 ± 15.1 years, p = 0.04), younger age at diagnosis of diabetes mellitus (46.2 ± 13.0 years, p = 0.01), having secondary education (p = 0.02), and having a history of depression (p = 0.002). Multivariate analysis showed that current age (p = 0.04), duration of diabetes mellitus (p = 0.04), age at diagnosis of diabetes mellitus (p = 0.01), and secondary education (p = 0.01) were significant factors.

    CONCLUSIONS: The prevalence of major depressive disorder was high among patients with type 2 diabetes mellitus. Screening of patients with type 2 diabetes mellitus for depression should be performed periodically or routinely, especially in the primary care setting.
  4. Fountoulakis KN, Karakatsoulis G, Abraham S, Adorjan K, Ahmed HU, Alarcón RD, et al.
    Eur Neuropsychopharmacol, 2022 Jan;54:21-40.
    PMID: 34758422 DOI: 10.1016/j.euroneuro.2021.10.004
    INTRODUCTION: There are few published empirical data on the effects of COVID-19 on mental health, and until now, there is no large international study.

    MATERIAL AND METHODS: During the COVID-19 pandemic, an online questionnaire gathered data from 55,589 participants from 40 countries (64.85% females aged 35.80 ± 13.61; 34.05% males aged 34.90±13.29 and 1.10% other aged 31.64±13.15). Distress and probable depression were identified with the use of a previously developed cut-off and algorithm respectively.

    STATISTICAL ANALYSIS: Descriptive statistics were calculated. Chi-square tests, multiple forward stepwise linear regression analyses and Factorial Analysis of Variance (ANOVA) tested relations among variables.

    RESULTS: Probable depression was detected in 17.80% and distress in 16.71%. A significant percentage reported a deterioration in mental state, family dynamics and everyday lifestyle. Persons with a history of mental disorders had higher rates of current depression (31.82% vs. 13.07%). At least half of participants were accepting (at least to a moderate degree) a non-bizarre conspiracy. The highest Relative Risk (RR) to develop depression was associated with history of Bipolar disorder and self-harm/attempts (RR = 5.88). Suicidality was not increased in persons without a history of any mental disorder. Based on these results a model was developed.

    CONCLUSIONS: The final model revealed multiple vulnerabilities and an interplay leading from simple anxiety to probable depression and suicidality through distress. This could be of practical utility since many of these factors are modifiable. Future research and interventions should specifically focus on them.

  5. Fountoulakis KN, Vrublevska J, Abraham S, Adorjan K, Ahmed HU, Alarcón RD, et al.
    J Affect Disord, 2024 Feb 19.
    PMID: 38382816 DOI: 10.1016/j.jad.2024.02.050
    BACKGROUND: The COVID-19 pandemic has brought significant mental health challenges, particularly for vulnerable populations, including non-binary gender individuals. The COMET international study aimed to investigate specific risk factors for clinical depression or distress during the pandemic, also in these special populations.

    METHODS: Chi-square tests were used for initial screening to select only those variables which would show an initial significance. Risk Ratios (RR) were calculated, and a Multiple Backward Stepwise Linear Regression Analysis (MBSLRA) was followed with those variables given significant results at screening and with the presence of distress or depression or the lack of both of them.

    RESULTS: The most important risk factors for depression were female (RR = 1.59-5.49) and non-binary gender (RR = 1.56-7.41), unemployment (RR = 1.41-6.57), not working during lockdowns (RR = 1.43-5.79), bad general health (RR = 2.74-9.98), chronic somatic disorder (RR = 1.22-5.57), history of mental disorders (depression RR = 2.31-9.47; suicide attempt RR = 2.33-9.75; psychosis RR = 2.14-10.08; Bipolar disorder RR = 2.75-12.86), smoking status (RR = 1.15-5.31) and substance use (RR = 1.77-8.01). The risk factors for distress or depression that survived MBSLRA were younger age, being widowed, living alone, bad general health, being a carer, chronic somatic disorder, not working during lockdowns, being single, self-reported history of depression, bipolar disorder, self-harm, suicide attempts and of other mental disorders, smoking, alcohol, and substance use.

    CONCLUSIONS: Targeted preventive interventions are crucial to safeguard the mental health of vulnerable groups, emphasizing the importance of diverse samples in future research.

    LIMITATIONS: Online data collection may have resulted in the underrepresentation of certain population groups.

  6. Hashim NA, Yusof ZYM, Saub R
    Community Dent Oral Epidemiol, 2019 02;47(1):24-31.
    PMID: 30187941 DOI: 10.1111/cdoe.12417
    OBJECTIVES: To evaluate the sensitivity and responsiveness of the Malay version of Early Childhood Oral Health Impact Scale (Malay-ECOHIS) to dental treatment of early childhood caries (ECC) under general anaesthesia (GA) and determine the minimally important difference (MID) for the Malay-ECOHIS.

    METHODS: A sample of 158 preschool children with ECC awaiting dental treatment under GA was recruited over an 8-month period. Parents self-completed the Malay-ECOHIS before and 4 weeks after their child's dental treatment. At 4 weeks follow-up, parents also responded to a global health transition judgement item. Data were analysed using independent and paired samples t tests, ANOVA and Pearson correlation coefficients.

    RESULTS: The response rate was 87.3%. The final sample comprised 76 male (55.1%) and 62 female (44.9%) preschool children with mean age of 4.5 (SD = 1.0) years. Following treatment, there were significant reductions in mean scores for total Malay-ECOHIS, child impact section (CIS), family impact section (FIS) and all domains, respectively (P 

  7. Satho T, Dieng H, Ahmad MH, Ellias SB, Hassan AA, Abang F, et al.
    Parasit Vectors, 2015 May 14;8:272.
    PMID: 25966847 DOI: 10.1186/s13071-015-0874-6
    BACKGROUND: Dengue is a prevalent arboviral disease and the development of insecticide resistance among its vectors impedes endeavors to control it. Coffee is drunk by millions of people daily worldwide, which is associated with the discarding of large amounts of waste. Coffee and its waste contain large amounts of chemicals many of which are highly toxic and none of which have a history of resistance in mosquitoes. Once in solution, coffee is brownish in colour, resembling leaf infusion, which is highly attractive to gravid mosquitoes. To anticipate the environmental issues related to the increasing popularity of coffee as a drink, and also to combat insecticide resistance, we explored the deterrence potentials of coffee leachates against the ovipositing and embryonic stages of the dengue vector, Aedes albopictus.

    METHODS: In a series of choice, no-choice, and embryo toxicity bioassays, we examined changes in the ovipositional behaviours and larval eclosion of Ae. albopictus in response to coffee extracts at different concentrations.

    RESULTS: Oviposition responses were extremely low when ovicups holding highly concentrated extract (HCE) of coffee were the only oviposition sites. Gravid females retained increased numbers of mature eggs until 5 days post-blood feeding. When provided an opportunity to oviposit in cups containing coffee extracts and with water, egg deposition occurred at lower rates in those containing coffee, and HCE cups were far less attractive to females than those containing water only. Females that successfully developed in a coffee environment preferentially oviposited in such cups when in competition with preferred oviposition sites (water cups), but this trait did not continue into the fourth generation. Larval eclosion occurred at lower rates among eggs that matured in a coffee environment, especially among those that were maintained on HCE-moistened substrates.

    CONCLUSIONS: The observations of the present study indicate a pronounced vulnerability of Ae. albopictus to the presence of coffee in its habitats during the early phases of its life cycle. The observations that coffee repels gravid females and inhibits larval eclosion provide novel possibilities in the search for novel oviposition deterrents and anti-larval eclosion agents against dengue vectors.

  8. Dieng H, The CC, Satho T, Miake F, Wydiamala E, Kassim NFA, et al.
    Acta Trop, 2019 Jun;194:93-99.
    PMID: 30922800 DOI: 10.1016/j.actatropica.2019.03.027
    Sound and its reception are crucial for reproduction, survival, and population maintenance of many animals. In insects, low-frequency vibrations facilitate sexual interactions, whereas noise disrupts the perception of signals from conspecifics and hosts. Despite evidence that mosquitoes respond to sound frequencies beyond fundamental ranges, including songs, and that males and females need to struggle to harmonize their flight tones, the behavioral impacts of music as control targets remain unexplored. In this study, we examined the effects of electronic music (Scary Monsters and Nice Sprites by Skrillex) on foraging, host attack, and sexual activities of the dengue vector Aedes aegypti. Adults were presented with two sound environments (music-off or music-on). Discrepancies in visitation, blood feeding, and copulation patterns were compared between environments with and without music. Ae. aegypti females maintained in the music-off environment initiated host visits earlier than those in the music-on environment. They visited the host significantly less often in the music-on than the music-off condition. Females exposed to music attacked hosts much later than their non-exposed peers. The occurrence of blood feeding activity was lower when music was being played. Adults exposed to music copulated far less often than their counterparts kept in an environment where there was no music. In addition to providing insight into the auditory sensitivity of Ae. aegypti to sound, our results indicated the vulnerability of its key vectorial capacity traits to electronic music. The observation that such music can delay host attack, reduce blood feeding, and disrupt mating provides new avenues for the development of music-based personal protective and control measures against Aedes-borne diseases.
  9. Teng CL, Nurjahan MI, Hashim NA, Punithambigai P, Leong KC, Mihat O
    Med J Malaysia, 2003 Jun;58(2):159-66.
    PMID: 14569735 MyJurnal
    Over a 2-week period, the management of upper respiratory tract infection by 24 medical officers and medical assistants in Seremban District was studied. Each practitioner recorded clinical data and prescription for twenty consecutive patients using a structured questionnaire. The extent to which the practitioners used "predictive features" (fever, absence of cough, cervical adenopathy, enlarged tonsils and exudates on tonsils) in clinical decision-making was analysed. The mean antibiotic prescription rate was 28.7% (95% CI: 24.6%, 33.0%). The antibiotic prescription rate of medical officers and medical assistants were similar. Five features were independently associated with antibiotic prescription (phlegm, fever, cervical adenopathy, red throat and tonsillar exudates). Antibiotics were prescribed for 22.1% of patients with 0-1 predictive features. High prescribers were 5 times more likely to prescribe antibiotics in this group of patients than low prescribers. To a large extent the clinical decision-making of practitioners in this study was evidence based. However, they were unduly influenced by purulent manifestation (phlegm) and redness of throat. The antibiotic prescription rate in these government health clinics is potentially reducible by means of educational intervention.
  10. Amir Hashim NA, Ab-Rahim S, Wan Ngah WZ, Nathan S, Ab Mutalib NS, Sagap I, et al.
    Bioimpacts, 2021;11(1):33-43.
    PMID: 33469506 DOI: 10.34172/bi.2021.05
    Introduction:
    The serum metabolomics approach has been used to identify metabolite biomarkers that can diagnose colorectal cancer (CRC) accurately and specifically. However, the biomarkers identified differ between studies suggesting that more studies need to be performed to understand the influence of genetic and environmental factors. Therefore, this study aimed to identify biomarkers and affected metabolic pathways in Malaysian CRC patients.
    Methods:
    Serum from 50 healthy controls and 50 CRC patients were collected at UKM Medical Centre. The samples were deproteinized with acetonitrile and untargeted metabolomics profile determined using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOFMS, Agilent USA). The data were analysed using Mass Profiler Professional (Agilent, USA) software. The panel of biomarkers determined were then used to identify CRC from a new set of 20 matched samples.
    Results:
    Eleven differential metabolites were identified whose levels were significantly different between CRC patients compared to normal controls. Based on the analysis of the area under the curve, 7 of these metabolites showed high sensitivity and specificity as biomarkers. The use of the 11 metabolites on a new set of samples was able to differentiate CRC from normal samples with 80% accuracy. These metabolites were hypoxanthine, acetylcarnitine, xanthine, uric acid, tyrosine, methionine, lysoPC, lysoPE, citric acid, 5-oxoproline, and pipercolic acid. The data also showed that the most perturbed pathways in CRC were purine, catecholamine, and amino acid metabolisms.
    Conclusion:
    Serum metabolomics profiling can be used to identify distinguishing biomarkers for CRC as well as to further our knowledge of its pathophysiological mechanisms.
  11. Hasan SW, Said SM, Sabri MF, Bakar AS, Hashim NA, Hasnan MM, et al.
    Sci Rep, 2016 07 06;6:29328.
    PMID: 27381946 DOI: 10.1038/srep29328
    Thermo-Electrochemical cells (Thermocells/TECs) transform thermal energy into electricity by means of electrochemical potential disequilibrium between electrodes induced by a temperature gradient (ΔT). Heat conduction across the terminals of the cell is one of the primary reasons for device inefficiency. Herein, we embed Poly(Vinylidene Fluoride) (PVDF) membrane in thermocells to mitigate the heat transfer effects - we refer to these membrane-thermocells as MTECs. At a ΔT of 12 K, an improvement in the open circuit voltage (Voc) of the TEC from 1.3 mV to 2.8 mV is obtained by employment of the membrane. The PVDF membrane is employed at three different locations between the electrodes i.e. x = 2 mm, 5 mm, and 8 mm where 'x' defines the distance between the cathode and PVDF membrane. We found that the membrane position at x = 5 mm achieves the closest internal ∆T (i.e. 8.8 K) to the externally applied ΔT of 10 K and corresponding power density is 254 nWcm(-2); 78% higher than the conventional TEC. Finally, a thermal resistivity model based on infrared thermography explains mass and heat transfer within the thermocells.
  12. Munretnam K, Alex L, Ramzi NH, Chahil JK, Kavitha IS, Hashim NA, et al.
    Mol Biol Rep, 2014;41(4):2501-8.
    PMID: 24443231 DOI: 10.1007/s11033-014-3107-8
    There is growing global interest to stratify men into different levels of risk to developing prostate cancer, thus it is important to identify common genetic variants that confer the risk. Although many studies have identified more than a dozen common genetic variants which are highly associated with prostate cancer, none have been done in Malaysian population. To determine the association of such variants in Malaysian men with prostate cancer, we evaluated a panel of 768 SNPs found previously associated with various cancers which also included the prostate specific SNPs in a population based case control study (51 case subjects with prostate cancer and 51 control subjects) in Malaysian men of Malay, Chinese and Indian ethnicity. We identified 21 SNPs significantly associated with prostate cancer. Among these, 12 SNPs were strongly associated with increased risk of prostate cancer while remaining nine SNPs were associated with reduced risk. However, data analysis based on ethnic stratification led to only five SNPs in Malays and 3 SNPs in Chinese which remained significant. This could be due to small sample size in each ethnic group. Significant non-genetic risk factors were also identified for their association with prostate cancer. Our study is the first to investigate the involvement of multiple variants towards susceptibility for PC in Malaysian men using genotyping approach. Identified SNPs and non-genetic risk factors have a significant association with prostate cancer.
  13. Velapasamy S, Alex L, Chahil JK, Lye SH, Munretnam K, Hashim NA, et al.
    Genet Test Mol Biomarkers, 2013 Jan;17(1):62-8.
    PMID: 23113749 DOI: 10.1089/gtmb.2012.0223
    The identification of high-risk individuals can help to improve early cancer detection and patient survival. Risk assessment, however, can only be accomplished if the risk factors are known. To date, the genetic risk factors for ovarian cancer, other than mutations in the BRCA1/2 genes, have never been systematically explored in Malaysia. The present study aims to identify from a panel of cancer-associated single-nucleotide polymorphisms (SNPs), those associated with ovarian cancer risk in Malaysia.
  14. Nor Hashim NA, Ramzi NH, Velapasamy S, Alex L, Chahil JK, Lye SH, et al.
    Asian Pac J Cancer Prev, 2012;13(12):6005-10.
    PMID: 23464394
    BACKGROUND: Nasopharyngeal carcinoma (NPC) is endemic in Southern Chinese and Southeast Asian populations. Geographical and ethnic clustering of the cancer is due to genetic, environmental, and lifestyle risk factors. This case-control study aimed to identify or confirm both genetic and non-genetic risk factors for NPC in one of the endemic countries, Malaysia.

    MATERIALS AND METHOD: A panel of 768 single-nucleotide polymorphisms (SNPs) previously associated with various cancers and known non-genetic risk factors for NPC were selected and analyzed for their associations with NPC in a case-control study.

    RESULTS: Statistical analysis identified 40 SNPs associated with NPC risk in our population, including 5 documented previously by genome-wide association studies (GWAS) and other case-control studies; the associations of the remaining 35 SNPs with NPC were novel. In addition, consistent with previous studies, exposure to occupational hazards, overconsumption of salt-cured foods, red meat, as well as low intake of fruits and vegetables were also associated with NPC risk.

    CONCLUSIONS: In short, this study confirmed and/or identified genetic, environmental and dietary risk factors associated with NPC susceptibility in a Southeast Asian population.

  15. Ramzi NH, Chahil JK, Lye SH, Munretnam K, Sahadevappa KI, Velapasamy S, et al.
    Indian J Med Res, 2014 Jun;139(6):873-82.
    PMID: 25109722
    Colorectal cancer (CRC) is second only to breast cancer as the leading cause of cancer-related deaths in Malaysia. In the Asia-Pacific area, it is the highest emerging gastrointestinal cancer. The aim of this study was to identify single nucleotide polymorphisms (SNPs) and environmental factors associated with CRC risk in Malaysia from a panel of cancer associated SNPs.
  16. Hashim NA, Ahmad AH, Talib A, Athaillah F, Krishnan KT
    Trop Life Sci Res, 2018 Mar;29(1):213-227.
    PMID: 29644025 MyJurnal DOI: 10.21315/tlsr2018.29.1.14
    The occurrence of major outbreaks of dengue, and other vector borne diseases such as chikungunya and zika in tropical and subtropical regions has rendered control of the diseases a top-priority for many affected countries including Malaysia. Control of the mosquito vectors Aedes aegypti and Aedes albopictus through the reduction of breeding sites and the application of insecticides to kill immature forms and adults are the main control efforts to combat these diseases. The present study describes the association between Ae. albopictus and Ae. aegypti in shared breeding sites. This study is important given that any measure taken against one species may affect the other. A yearlong larval survey was conducted in four dengue endemic areas of Penang Island. Sorenson's coefficient index indicated that no association between number of the immatures of the two species regardless of container size and study location. Therefore, the mean number Ae. albopictus immature was not decreased in the presence of Ae. aegypti in shared breeding container. However Ae. aegypti appeared to prefer breeding in habitats not occupied by Ae. albopictus, the two species sharing breeding sites only where available containers were limited. In control efforts, eliminating the preferred breeding containers for one species might not affect or reduce the population of the other species.
  17. Mohamed Sofian Z, Harun N, Mahat MM, Nor Hashim NA, Jones SA
    Eur J Pharm Biopharm, 2021 Nov;168:53-61.
    PMID: 34455038 DOI: 10.1016/j.ejpb.2021.08.003
    Transiently associating amines with therapeutic agents through the formation of ion-pairs has been established both in vitro and in vivo as an effective means to systemically direct drug delivery to the lung via the polyamine transport system (PTS). However, there remains a need to better understand the structural traits required for effective PTS uptake of drug ion-pairs. This study aimed to use a structurally related series of amine counterions to investigate how they influenced the stability of theophylline ion-pairs and their active uptake in A549 cells. Using ethylamine (mono-amine), ethylenediamine (di-amine), spermidine (tri-amine) and spermine (tetra-amine) as counterions the ion-pair affinity was shown to increase as the number of protonated amine groups in the counterion structure increased. The mono and diamines generated a single hydrogen bond and the weakest ion-pair affinities (pKFTIR: 1.32 ± 0.04 and 1.43 ± 0.02) whereas the polyamines produced two hydrogen bonds and thus the strongest ion-pair affinities (pKFTIR: 1.93 ± 0.05 and 1.96 ± 0.04). In A549 cells depleted of endogenous polyamines using α-difluoromethylornithine (DFMO), the spermine-theophylline uptake was significantly increased (p 
  18. Hashim A, Hashim NA, Mohd Junaidi MU, Kamarudin D, Hussain MA
    Water Sci Technol, 2022 Sep;86(5):1055-1065.
    PMID: 36358045 DOI: 10.2166/wst.2022.253
    Flood is among the natural disasters that commonly happened in Malaysia every year. During the flood, victims faced clean water shortages and deterioration of the environment resulting in long waiting times for aid to access. Hence, affordable and efficient filters are needed to supply clean water in the affected areas. Application of xylem tissue inside plant stem has the potential as a filter for water filtration. This research focuses on xylem tissue in Malaysian tropical plants from cassava stem. Cassava stems were prepared in a small-scale set-up as the xylem was used as a filter. Effects of cross-sectional area and hydrostatic pressure were analyzed and the results showed a directly proportional relationship with permeate flow rate. Upon filtration with red dye solution, total dye removal was achieved using a xylem with a minimal length of 3 cm and onwards. While for bacteria removal, E. coli bacteria have been removed when tested with a bacteria count plate. Thus, this study demonstrated the potential of the xylem tissue of the cassava plant as affordable and available natural raw materials to be used as water filters during an emergency.
  19. Kakihana Y, Hashim NA, Mizuno T, Anno M, Higa M
    Membranes (Basel), 2021 Jun 19;11(6).
    PMID: 34205395 DOI: 10.3390/membranes11060452
    Membrane resistance and permselectivity for counter-ions have important roles in determining the performance of cation-exchange membranes (CEMs). In this study, PVA-based polyanions-poly(vinyl alcohol-b-sodium styrene sulfonate)-were synthesized, changing the molar percentages CCEG of the cation-exchange groups with respect to the vinyl alcohol groups. From the block copolymer, poly(vinyl alcohol) (PVA)-based CEMs, hereafter called "B-CEMs", were prepared by crosslinking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations CGA. The ionic transport properties of the B-CEMs were compared with those previously reported for the CEMs prepared using a random copolymer-poly(vinyl alcohol-co-2-acrylamido-2-methylpropane sulfonic acid)-hereafter called "R-CEMs". The B-CEMs had lower water content than the R-CEMs at equal molar percentages of the cation-exchange groups. The charge density of the B-CEMs increased as CCEG increased, and reached a maximum value, which increased with increasing CGA. A maximum charge density of 1.47 mol/dm3 was obtained for a B-CEM with CCEG = 2.9 mol% and CGA = 0.10 vol.%, indicating that the B-CEM had almost two-thirds of the permselectivity of a commercial CEM (CMX: ASTOM Corp. Japan). The dynamic transport number and membrane resistance of a B-CEM with CCEG = 8.3 mol% and CGA = 0.10 vol.% were 0.99 and 1.6 Ωcm2, respectively. The B-CEM showed higher dynamic transport numbers than those of the R-CEMs with similar membrane resistances.
  20. Salleh WM, Hashim NA, Ahmad F, Heng Yen K
    Adv Pharm Bull, 2014 Dec;4(Suppl 2):527-31.
    PMID: 25671185 DOI: 10.5681/apb.2014.078
    PURPOSE: The aim of this study was to investigate acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and antityrosinase activities of extracts from ten Piper species namely; P. caninum, P. lanatum, P. abbreviatum, P. aborescens, P. porphyrophyllum, P. erecticaule, P. ribesioides, P. miniatum, P. stylosum, and P. majusculum.

    METHODS: Anticholinesterase and antityrosinase activities were evaluated against in vitro Ellman spectroscopy method and mushroom tyrosinase, respectively.

    RESULTS: The EtOAc extract of P. erecticaule showed the highest AChE and BChE inhibitory with 22.9% and 70.9% inhibition, respectively. In antityrosinase activity, all extracts of P. porphyrophyllum showed the highest inhibitory effects against mushroom tyrosinase, compared to standard, kojic acid.

    CONCLUSION: This study showed that P. erecticaule and P. porphyrophyllum have potential AChE/BChE and tyrosinase inhibition activities. The respective extracts can be explored further for the development of novel lead as AChE/BChE and tyrosinase inhibitors in therapeutic management of Alzheimer's disease.

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