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Influence of bariatric surgery on weight reduction and control of chronic disease among obese patients in Malaysia

Tan KC, Chang CT, Cheah WK, Vinayak CR, Chan HK

Med J Malaysia, 2019 Jun;74(3):215-218.
PMID: 31256176

INTRODUCTION: This study was designed to determine the influence of bariatric surgery on changes in the body mass index (BMI), and the control of diabetes, hypertension and dyslipidaemia among obese patients in Malaysia.
MATERIALS AND METHODS: This was a retrospective cohort study undertaken at a public tertiary care centre in the state of Perak, Malaysia. Information of obese patients who underwent bariatric surgery was obtained from their medical records. The changes in the BMI, HbA1C, systolic and diastolic blood pressure (SBP and DBP), and lipid levels between three months before and after the surgery were assessed.
RESULTS: The patients (n=106) were mostly Malay (66.0%), had at least one comorbidity (61.3%), and had a mean age of 40.38±11.75 years. Following surgery, the BMI of the patients was found to reduce by 9.78±5.82kg/m2. For the patients who had diabetes (n=24) and hypertension (n=47), their mean HbA1C, SBP and DBP were also shown to reduce significantly by 2.02±2.13%, 17.19±16.97mmHg, and 11.45±12.63mmHg, respectively. Meanwhile, the mean total cholesterol, triglyceride and low-density lipoprotein levels of those who had dyslipidaemia (n=21) were, respectively, lowered by 0.91±1.18mmol/L, 0.69±1.11mmol/L and 0.47±0.52mmol/L.
CONCLUSION: The findings suggest that in addition to weight reduction, bariatric surgery is helpful in improving the diabetes, hypertension and dyslipidaemia control among obese patients. However, a large-scale trial with a control group is required to verify our findings.
A web-based educational intervention module to improve knowledge and attitudes towards thalassaemia prevention in Malaysian young adults

Ngim CF, Ibrahim H, Abdullah N, Lai NM, Tan RKM, Ng CS, et al.

Med J Malaysia, 2019 Jun;74(3):219-225.
PMID: 31256177

BACKGROUND: Thalassaemia is a public health burden in Malaysia and its prevention faces many challenges. In this study, we aimed to assess the effectiveness of a web-based educational module in improving knowledge and attitudes about thalassaemia prevention amongst Malaysian young adults.
METHODS: We designed an interactive web-based educational module in the Malay language wherein videos were combined with text and pictorial visual cues. Malaysians aged 18-40 years old who underwent the module had their knowledge and attitudes assessed at baseline, post-intervention and at 6-month follow-up using a selfadministered validated questionnaire.
RESULTS: Sixty-five participants: 47 Malays (72.3%), 15 Chinese (23.1%), three Indians (4.6%) underwent the module. Questionnaires were completed at baseline (n=65), postintervention (n=65) and at 6-month follow-up (n=60). Out of a total knowledge score of 21, significant changes were recorded across three time-points- median scores were 12 at pre-intervention, 19 at post-intervention and 16 at 6-month follow-up (p<0.001). Post-hoc testing comparing preintervention and 6-month follow-up scores showed significant retention of knowledge (p<0.001). Compared to baseline, attitudes at 6-month follow-up showed an increased acceptance for "marriage avoidance between carriers" (pre-intervention 20%, 6-month follow-up 48.3%, p<0.001) and "prenatal diagnosis" (pre-intervention 73.8%, 6-month follow-up 86.2%, p=0.008). Acceptance for selective termination however, remained low without significant change (pre-intervention 6.2%, 6-month follow-up 16.7%, p=0.109).
CONCLUSION: A web-based educational module appears effective in improving knowledge and attitudes towards thalassaemia prevention and its incorporation in thalassaemia prevention programs is potentially useful in Malaysia and countries with a high internet penetration rate.
Fulltext Discovery of novel genic-SSR markers from transcriptome dataset of an important non-human primate, Macaca fascicularis

Chang W, Ee-Uli J, Ng WL, Rovie-Ryan JJ, Tan SG, Yong CSY

Sci Rep, 2019 06 11;9(1):8504.
PMID: 31186469 DOI: 10.1038/s41598-019-44870-4

Macaca fascicularis, also known as the cynomolgus macaque, is an important non-human primate animal model used in biomedical research. It is an Old-World primate widely distributed in Southeast Asia and is one of the most abundant macaque species in Malaysia. However, the genetic structure of wild cynomolgus macaque populations in Malaysia has not been thoroughly elucidated. In this study, we developed genic-simple sequence repeat (genic-SSR) markers from an in-house transcriptome dataset generated from the Malaysian cynomolgus macaque via RNA sequencing, and applied these markers on 26 cynomolgus macaque individuals. A collection of 14,751 genic-SSRs were identified, where 13,709 were perfect SSRs. Dinucleotide repeats were the most common repeat motifs with a frequency of 65.05%, followed by trinucleotide repeats (20.55%). Subsequently, we designed 300 pairs of primers based on perfect di- and trinucleotide SSRs, in which 105 SSRs were associated with functional genes. A subset of 30 SSR markers were randomly selected and validated, yielding 19 polymorphic markers with an average polymorphism information content value of 0.431. The development of genic-SSR markers in this study is indeed timely to provide useful markers for functional and population genetic studies of the cynomolgus macaque and other related non-human primate species.
A new approach for arrhythmia classification using deep coded features and LSTM networks

Yildirim O, Baloglu UB, Tan RS, Ciaccio EJ, Acharya UR

Comput Methods Programs Biomed, 2019 Jul;176:121-133.
PMID: 31200900 DOI: 10.1016/j.cmpb.2019.05.004

BACKGROUND AND OBJECTIVE: For diagnosis of arrhythmic heart problems, electrocardiogram (ECG) signals should be recorded and monitored. The long-term signal records obtained are analyzed by expert cardiologists. Devices such as the Holter monitor have limited hardware capabilities. For improved diagnostic capacity, it would be helpful to detect arrhythmic signals automatically. In this study, a novel approach is presented as a candidate solution for these issues.
METHODS: A convolutional auto-encoder (CAE) based nonlinear compression structure is implemented to reduce the signal size of arrhythmic beats. Long-short term memory (LSTM) classifiers are employed to automatically recognize arrhythmias using ECG features, which are deeply coded with the CAE network.
RESULTS: Based upon the coded ECG signals, both storage requirement and classification time were considerably reduced. In experimental studies conducted with the MIT-BIH arrhythmia database, ECG signals were compressed by an average 0.70% percentage root mean square difference (PRD) rate, and an accuracy of over 99.0% was observed.
CONCLUSIONS: One of the significant contributions of this study is that the proposed approach can significantly reduce time duration when using LSTM networks for data analysis. Thus, a novel and effective approach was proposed for both ECG signal compression, and their high-performance automatic recognition, with very low computational cost.
Diabetes, arthritis, urinary incontinence, poor self-rated health, higher body mass index and lower handgrip strength are associated with falls among community-dwelling middle-aged and older adults: Pooled analyses from two cross-sectional Malaysian datasets

Singh DKA, Shahar S, Vanoh D, Kamaruzzaman SB, Tan MP

Geriatr Gerontol Int, 2019 Aug;19(8):798-803.
PMID: 31237103 DOI: 10.1111/ggi.13717

AIM: The identification of risk factors associated with comorbidities and physical fitness might provide pathways for planning therapeutic targets for future falls prevention. Results from large datasets that examined falls risk factors in Asia have been limited. The aim of the present study was to identify the risk factors for falls by pooling data consisting of medical history, physical performance and self-rated health from two large Malaysian epidemiological studies.
METHODS: Matching variables from the Towards Useful Aging and Malaysian Elders Longitudinal Research datasets related to falls, physical performance and determinants of falls were identified and pooled for analysis. The Timed Up and Go test and dominant handgrip strength tests were used as physical performance measures. Falls were self-reported, and functional status was assessed using activities of daily living.
RESULTS: Data of 3935 participants, mean age 68.9 ± 6.8 years, 2127 (54.0%) women and 1807 (46.0%) men were extracted for analyses. In an adjusted model, independent risk factors for falls from this cohort studies were diabetes (OR 1.258), arthritis (OR 1.366), urinary incontinence (OR 1.346), poor self-rated health (OR 1.293), higher body mass index (OR 1.029) and lower handgrip strength (OR 1.234).
CONCLUSIONS: Although the risk factors that emerged from our analyses were similar to available studies among older adults, the Timed Up and Go test did not appear as one of the risk factors in the present study that included middle-aged adults. Our findings will require confirmation in a prospective study. Geriatr Gerontol Int 2019; 19: 798-803.
Fulltext Identification of Antidiabetic Metabolites from Paederia foetida L. Twigs by Gas Chromatography-Mass Spectrometry-Based Metabolomics and Molecular Docking Study

Tan DC, Kassim NK, Ismail IS, Hamid M, Ahamad Bustamam MS

Biomed Res Int, 2019;2019:7603125.
PMID: 31275982 DOI: 10.1155/2019/7603125

Paederia foetida L. (Rubiaceae) is a climber which is widely distributed in Asian countries including Malaysia. The plant is traditionally used to treat various diseases including diabetes. This study is to evaluate the enzymatic inhibition activity of Paederia foetida twigs extracts and to identify the metabolites responsible for the bioactivity by gas chromatography-mass spectrometry (GC-MS) metabolomics profiling. Three different twig extracts, namely, hexane (PFH), chloroform (PFC), and methanol (PFM), were submerged for their α-amylase and α-glucosidase inhibition potential in 5 replicates for each. Results obtained from the loading column scatter plot of orthogonal partial least square (OPLS) model revealed the presence of 12 bioactive compounds, namely, dl-α-tocopherol, n-hexadecanoic acid, 2-hexyl-1-decanol, stigmastanol, 2-nonadecanone, cholest-8(14)-en-3-ol, 4,4-dimethyl-, (3β,5α)-, stigmast-4-en-3-one, stigmasterol, 1-ethyl-1-tetradecyloxy-1-silacyclohexane, ɣ-sitosterol, stigmast-7-en-3-ol, (3β,5α,24S)-, and α-monostearin. In silico molecular docking was carried out using the crystal structure α-amylase (PDB ID: 4W93) and α-glucosidase (PDB ID: 3WY1). α-Amylase-n-hexadecanoic acid exhibited the lowest binding energy of -2.28 kcal/mol with two hydrogen bonds residue, namely, LYS178 and TYR174, along with hydrophobic interactions involving PRO140, TRP134, SER132, ASP135, and LYS172. The binding interactions of α-glucosidase-n-hexadecanoic acid complex ligand also showed the lowest binding energy among 5 major compounds with the energy value of -4.04 kcal/mol. The complex consists of one hydrogen bond interacting residue, ARG437, and hydrophobic interactions with ALA444, ASP141, GLN438, GLU432, GLY374, LEU373, LEU433, LYS352, PRO347, THR445, HIS348, and PRO351. The study provides informative data on the potential antidiabetic inhibitors identified in Paederia foetida twigs, indicating the plant has the therapeutic effect properties to manage diabetes.
Fulltext Colorectal cancer screening using immunochemical fecal occult blood test

Tan MC, Ng OC, Yap RYP, Pan Y, Chieng JY

Malaysian Journal of Public Health Medicine, 2017;17(1):33-37.

Fecal occult blood test (FOBT) screening has been shown to decrease the incidence and mortality of colorectal cancer (CRC). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the immunochemical fecal occult blood test (i-FOBT) in diagnosing CRC were assessed among the patients in a tertiary referral hospital in Malaysia. A total sample of 814 patients aged 16 to 85 years old who performed i-FOBT and endoscopic screenings was obtained. The patients were recruited for a retrospective investigation. Sensitivity, specificity, PPV, and NPV were derived for the CRC screenees. Out of the 814 patients screened using i-FOBT, half of them were above 59 years old (49.6%), and 36% had positive i-FOBT. Gender distribution was almost equal, where 53.4% of the patients were female, and 46.6% were male. Majority of the patients were Malays (56.6%), followed by Chinese (24.0%), Indians (16.5%), and others (2.9%). Among the 71 patients referred for colonoscopy, 57.7% and 42.3% corresponded to positive and negative i-FOBT cases, respectively. Polyps were found to be most common among the patients (25.6%), 7.0% were found positive for invasive CRC, and 35.2% had normal colonoscopic findings. There was a significant association between colonoscopic finding and positive i-FOBT (p=0.001). The sensitivity, specificity, PPV, and NPV for CRC detection were 66.7%, 43.0%, 9.8%, and 93.3%, respectively. The results indicate that i-FOBT is a useful tool in the detection of abnormalities in the lower gastrointestinal tract and therefore serves as a cornerstone for potential large-scale screening programmes.
Fulltext A Severe Form of M - protein Negative Distal Acquired Demyelinating Symmetric Neuropathy

Ong TL, Goh KJ, Shahrizaila N, Wong KT, Tan CY

Neurol India, 2019 12 21;67(6):1532-1535.
PMID: 31857554 DOI: 10.4103/0028-3886.273621

Distal acquired demyelinating symmetric neuropathy (DADS) is a variant of chronic inflammatory demyelinating polyneuropathy (CIDP) characterized by symmetrical, distal, sensory or sensorimotor involvement. DADS with M-protein (DADS-M) is less responsive to immunotherapy compared to those without M-protein (DADS-I). We report a case of DADS-I with severe clinical presentation viz. early hand involvement with marked wasting, inexcitable peripheral nerves on neurophysiology and poor response to immunotherapy. Despite the unusual presentation, ancillary tests including cerebrospinal fluid analysis, nerve biopsy and nerve ultrasound were supportive of an inflammatory demyelinating polyneuropathy. This case demonstrated the heterogeneity of the disorder and expands the clinical spectrum of DADS neuropathy.
Efficiency of Ionic Liquids-Based Aqueous Two-phase Electrophoresis for Partition of Cytochrome c

Kee PE, Lan JC, Yim HS, Tan JS, Chow YH, Ng HS

Appl Biochem Biotechnol, 2020 May;191(1):376-386.
PMID: 31907777 DOI: 10.1007/s12010-019-03202-y

Cytochrome c is a small water-soluble protein that is abundantly found in the mitochondrial intermembrane space of microorganism, plants and mammalians. Ionic liquids (ILs)-based aqueous two-phase electrophoresis system (ATPES) was introduced in this study to investigate the partition efficiency of cytochrome c to facilitate subsequent development of two-phase electrophoresis for the separation of cytochrome c from microbial fermentation. The 1-Hexyl-3-methylimidazolium bromide, (C6mim)Br and potassium citrate salt were selected as the phase-forming components. Effects of phase composition; position of electrodes; pH and addition of neutral salt on the partition efficiency of cytochrome c in the ATPES were evaluated. Highest partition coefficient (K = 179.12 ± 0.82) and yield of cytochrome c in top phase (YT = 99.63% ± 0.00) were recorded with IL/salt ATPES composed of 30% (w/w) (C6mim)Br and 20% (w/w) potassium citrate salt of pH 7 and 3.0% (w/w) NaCl addition with anode at the bottom phase and cathode at the top phase. The SDS-PAGE profile revealed that cytochrome c with a molecular weight of 12 kDa was preferably partitioned to the IL-rich top phase. Present findings suggested that the single-step ATPES is a potential separation approach for the recovery of cytochrome c from microbial fermentation. Graphical Abstract.
Fulltext An improved method for the rescue of recombinant Newcastle disease virus

Cheow PS, Tan TK, Song AA, Yusoff K, Chia SL

Biotechniques, 2020 02;68(2):96-100.
PMID: 31937115 DOI: 10.2144/btn-2019-0110

Reverse genetics has been used to generate recombinant Newcastle disease virus with enhanced immunogenic properties for vaccine development. The system, which involves co-transfecting the viral antigenomic plasmid with three helper plasmids into a T7 RNA polymerase-expressing cell to produce viral progenies, poses a great challenge. We have modified the standard transfection method to improve the transfection efficiency of the plasmids, resulting in a higher titer of virus progeny production. Two transfection reagents (i.e., lipofectamine and polyethylenimine) were used to compare the transfection efficiency of the four plasmids. The virus progenies produced were quantitated with flow cytometry analysis of the infectious virus unit. The modified transfection method increased the titer of virus progenies compared with that of the standard transfection method.
Fulltext Optimized artificial neural network to improve the accuracy of estimated fault impedances and distances for underground distribution system

Naidu K, Ali MS, Abu Bakar AH, Tan CK, Arof H, Mokhlis H

PLoS One, 2020;15(1):e0227494.
PMID: 31999711 DOI: 10.1371/journal.pone.0227494

This paper proposes an approach to accurately estimate the impedance value of a high impedance fault (HIF) and the distance from its fault location for a distribution system. Based on the three-phase voltage and current waveforms which are monitored through a single measurement in the network, several features are extracted using discrete wavelet transform (DWT). The extracted features are then fed into the optimized artificial neural network (ANN) to estimate the HIF impedance and its distance. The particle swarm optimization (PSO) technique is employed to optimize the parameters of the ANN to enhance the performance of fault impedance and distance estimations. Based on the simulation results, the proposed method records encouraging results compared to other methods of similar complexity for both HIF impedance values and estimated distances.
Characteristics and trajectory of patients with pediatric acute respiratory distress syndrome

Wong JJ, Tan HL, Lee SW, Chang KTE, Mok YH, Lee JH

Pediatr Pulmonol, 2020 04;55(4):1000-1006.
PMID: 32017471 DOI: 10.1002/ppul.24674

OBJECTIVE: This study delineates the disease trajectory of patients with pediatric acute respiratory distress syndrome (PARDS) defined by the Pediatric Acute Lung Injury Consensus Conference (PALICC) definition, and evaluates the impact of comorbidities on outcomes.
METHODS: This prospective study over November 2017-October 2019 was conducted in a single-center multidisciplinary pediatric intensive care unit (PICU) and included patients <21years of age with PARDS. Clinical history of those requiring mechanical ventilation for <3 days was interrogated and cases in which the diagnosis of PARDS were unlikely, identified. The impact of chronic comorbidities on clinical outcomes, in particular, pulmonary disease and immunosuppression, were analyzed.
RESULTS: Eighty-five of 1272 PICU admissions (6.7%) met the criteria for PARDS and were included. Median age and oxygenation indexes were 2.8 (0.6, 8.3) years and 10.6 (7.6, 15.4), respectively. Overall mortality was 12 out of 85 (14.1%). Despite fulfilling criteria in 6/85 (7.1%), hypoxemia contributed by bronchospasm, mucus plugging, fluid overload, and atelectasis was quickly reversible and PARDS was unlikely in these patients. Comorbidities (57/85 [67.1%]) were not associated with worsened outcomes. However, pre-existing pulmonary disease and immunosuppression were associated with severe PARDS (12/20 [60.0%] vs 19/65 [29.2%]; P = .017), extracorporeal membrane oxygenation use (5/20 [25.0%] vs 3/65 [4.6%]; P = .016) and reduced ventilator free days (VFD) (15 [0, 19] vs 21 [6, 23]; P = .039), compared with those without them.
CONCLUSION: A small percentage of children fulfilling the PALICC definition had quickly reversible hypoxemia with likely alternate pathophysiology to PARDS. Patients with pulmonary comorbidities and immunosuppression had a more severe course of PARDS compared with others.
Cytosine methylation of rice mitochondrial DNA from grain and leaf tissues

Muniandy K, Tan MH, Shehnaz S, Song BK, Ayub Q, Rahman S

Planta, 2020 Feb 01;251(2):57.
PMID: 32008119 DOI: 10.1007/s00425-020-03349-7

MAIN CONCLUSION: The rice leaf mitochondrial DNA is more methylated compared to the rice grain mitochondrial DNA. The old rice leaf mitochondrial DNA has also a higher methylation level than the young rice leaf mitochondrial DNA. The presence of DNA methylation in rice organelles has not been well characterized. We have previously shown that cytosine methylation of chloroplast DNA is different between leaf and grain, and varies between young and old leaves in rice. However, the variation in cytosine methylation of mitochondrial DNA is still poorly characterized. In this study, we have investigated cytosine methylation of mitochondrial DNA in the rice grain and leaf. Based on CpG, CHG, and CHH methylation analyses, the leaf mitochondrial DNA was found to be more methylated compared to the grain mitochondrial DNA. The methylation of the leaf mitochondrial DNA was also higher in old compared to young leaves. Differences in methylation were observed at different cytosine positions of the mitochondrial DNA between grain and leaf, although there were also positions with a similar level of high methylation in all the tissues examined. The differentially methylated cytosine positions in rice mitochondrial DNA were observed mostly in the intergenic region and in some mitochondrial-specific genes involved in ATP production, transcription, and translation. The functional importance of cytosine methylation in the life cycle of rice mitochondria is still to be determined.
Occurrence of pesticides in surface water, pesticides removal efficiency in drinking water treatment plant and potential health risk to consumers in Tengi River Basin, Malaysia

Elfikrie N, Ho YB, Zaidon SZ, Juahir H, Tan ESS

Sci Total Environ, 2020 Apr 10;712:136540.
PMID: 32050383 DOI: 10.1016/j.scitotenv.2020.136540

Agricultural activities have been arising along with the use of pesticides. The use of pesticides can impact not only on vector or other pest but also able to harm human health. Pesticide may leach from the irrigation of plant into the groundwater and in surface water. These waters could be sources of drinking water in a pesticides polluted area. This study aims to determine the occurrence pesticides in surface water and pesticides removal efficiency in a conventional drinking water treatment plant (DWTP) and the potential health risk to consumers. The study was conducted in Tanjung Karang, Selangor, Malaysia. Thirty river water samples and eighteen water samples from DWTP were collected. The water samples were extracted using solid phase extraction (SPE) before injected to the ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Five hundreds and ten respondents were interviewed using questionnaires to obtain information for health risk assessments. The results showed that propiconazole had the highest mean concentration (4493.1 ng/L) while pymetrozine had the lowest mean concentration (1.3 ng/L) in river water samples. The pesticides removal efficiencies in the conventional DWTP were 77% (imidacloprid), 86% (propiconazole and buprofezin), 88% (tebuconazole) and 100% (pymetrozine, tricyclazole, chlorantraniliprole, azoxystrobin and trifloxystrobin), respectively. The hazard quotients (HQs) and hazard index (HI) for all target pesticides were <1, indicating there was no significant chronic non-carcinogenic health risk due to consumption of the drinking water. Conventional DWTP was not able to completely remove four pesticide; thus, advanced treatment systems need to be considered to safeguard the health of the community in future.
Fulltext Caregiving Self-efficacy and Knowledge Regarding Patient Positioning Among Malaysian Caregivers of Stroke Patients

Tan CE, Hi MY, Azmi NS, Ishak NK, Mohd Farid FA, Abdul Aziz AF

Cureus, 2020 Mar 24;12(3):e7390.
PMID: 32337117 DOI: 10.7759/cureus.7390

Background Most family caregivers of stroke patients in Malaysia do not receive adequate prior preparation or training. This study aimed to determine levels of patient positioning knowledge and caregiving self-efficacy among caregivers of stroke patients. Methods This cross-sectional study was conducted at an urban teaching hospital involving 128 caregivers of stroke patients. The caregivers were conveniently sampled and completed the data collection forms, which comprised their socio-demographic data, patients' functional status, the Caregiving Knowledge For Stroke Questionnaire: Patient Positioning (CKQ-My© Patient Positioning) to measure caregiver's knowledge on patient positioning, and the Family Caregiver Activation Tool (FCAT©) to measure caregivers' self-efficacy in managing the patient. Descriptive and multivariate inferential statistics were used for data analysis. Results Among the caregivers sampled, 87.3% had poor knowledge of positioning (mean score 14.9 ± 4.32). The mean score for FCAT was 49.7 ± 6.0 from a scale of 10 to 60. There was no significant association between knowledge on positioning and self-efficacy. Multiple linear regression showed that caregivers' age (B = 0.146, p = 0.003) and caregiver training (B = 3.302, p = 0.007) were independently associated with caregivers' self-efficacy. Conclusion Caregivers' knowledge on the positioning of stroke patients was poor, despite a fairly good level of self-efficacy. Older caregivers and receiving caregiver training were independently associated with better caregiver self-efficacy. This supports the provision of caregiver training to improve caregiver self-efficacy.
Fulltext Magnetically recoverable magnetite-reduced graphene oxide as a demulsifier for surfactant stabilized crude oil-in-water emulsion

Yau XH, Khe CS, Mohamed Saheed MS, Lai CW, You KY, Tan WK

PLoS One, 2020;15(4):e0232490.
PMID: 32353051 DOI: 10.1371/journal.pone.0232490

Oily wastewater, especially water-oil emulsion has become serious environmental issue and received global attention. Chemical demulsifiers are widely used to treat oil-water emulsion, but the toxicity, non-recyclable and non-environmental friendly characteristic of chemical demulsifiers had limited their practical application in oil-water separation. Therefore, it is imperative to develop an efficient, simple, eco-friendly and recyclable demulsifiers for breaking up the emulsions from the oily wastewater. In this study, a magnetic demulsifier, magnetite-reduced graphene oxide (M-rGO) nanocomposites were proposed as a recyclable demulsifier to break up the surfactant stabilized crude oil-in-water (O/W) emulsion. M-rGO nanocomposites were prepared via in situ chemical synthesis by using only one type Fe salt and GO solid as precursor at room temperature. The prepared composites were fully characterized by various techniques. The effect of demulsifier dosage and pH of emulsion on demulsification efficiency (ED) has been studied in detailed. The demulsification mechanism was also proposed in this study. Results showed that M-rGO nanocomposites were able to demulsify crude O/W emulsion. The ED reaches 99.48% when 0.050 wt.% of M-rGO nanocomposites were added to crude O/W emulsion (pH = 4). Besides, M-rGO nanocomposites can be recycled up to 7 cycles without showing a significant change in terms of ED. Thus, M-rGO nanocomposite is a promising demulsifier for surfactant stabilized crude O/W emulsion.
Amycolatopsis granulosa sp. nov., Amycolatopsis ruanii sp. nov. and Amycolatopsis thermalba sp. nov., thermophilic actinomycetes isolated from arid soils

Zucchi TD, Tan GYA, Bonda ANV, Frank S, Kshetrimayum JD, Goodfellow M

Int J Syst Evol Microbiol, 2012 Jun;62(Pt 6):1245-1251.
PMID: 21764982 DOI: 10.1099/ijs.0.031039-0

The taxonomic positions of three thermophilic actinomycetes isolated from arid soil samples were established by using a polyphasic approach. The organisms had chemical and morphological features that were consistent with their classification in the genus Amycolatopsis. 16S rRNA gene sequence data supported the classification of the isolates in the genus Amycolatopsis and showed that they formed distinct branches in the Amycolatopsis methanolica subclade. DNA-DNA relatedness studies between the isolates and their phylogenetic neighbours showed that they belonged to distinct genomic species. The three isolates were readily distinguished from one another and from the type strains of species classified in the A. methanolica subclade based on a combination of phenotypic properties and by genomic fingerprinting. Consequently, it is proposed that the three isolates be classified in the genus Amycolatopsis as representatives of Amycolatopsis granulosa sp. nov. (type strain GY307(T) = NCIMB 14709(T) = NRRL B-24844(T)), Amycolatopsis ruanii sp. nov. (type strain NMG112(T) = NCIMB 14711(T) = NRRL B-24848(T)) and Amycolatopsis thermalba sp. nov. (type strain SF45(T) = NCIMB 14705(T) = NRRL B-24845(T)).
Fulltext Editorial: Perceptions of People: Cues to Underlying Physiology and Psychology

Sulikowski D, Tan KW, Jones AL, Welling LLM, Stephen ID

Front Psychol, 2020;11:643.
PMID: 32322229 DOI: 10.3389/fpsyg.2020.00643
Fulltext Healing Effect of Vicenin-2 (VCN-2) on Human Dermal Fibroblast (HDF) and Development VCN-2 Hydrocolloid Film Based on Alginate as Potential Wound Dressing

Tan WS, Arulselvan P, Ng SF, Taib CNM, Sarian MN, Fakurazi S

Biomed Res Int, 2020;2020:4730858.
PMID: 32382552 DOI: 10.1155/2020/4730858

Chronic wounds represent serious globally health care and economic issues especially for patients with hyperglycemic condition. Wound dressings have a predominant function in wound treatment; however, the dressings for the long-lasting and non-healing wounds are still a significant challenge in the wound care management market. Astonishingly, advanced wound dressing which is embedded with a synthetic drug compound in a natural polymer compound that acts as drug release carrier has brought about promising treatment effect toward injured wound. In the current study, results have shown that Vicenin-2 (VCN-2) compound in low concentration significantly enhanced cell proliferation and migration of HDF. It also regulated the production of pro-inflammatory cytokines such as IL-6, IL-1β, and TNF-α from HDF in wound repair. Treatment of VCN-2 also has facilitated the expression of TGF-1β and VEGF wound healing maker in a dose-dependent manner. A hydrocolloid film based on sodium alginate (SA) incorporated with VCN-2 synthetic compound which targets to promote wound healing particularly in diabetic condition was successfully developed and optimized for its physico-chemical properties. It was discovered that all the fabricated film formulations prepared were smooth, translucent, and good with flexibility. The thickness and weight of the formulations were also found to be uniform. The hydrophilic polymer comprised of VCN-2 were shown to possess desirable wound dressing properties and superior mechanical characteristics. The drug release profiles have revealed hydrocolloid film, which is able to control and sustain the VCN-2 released to wound area. In short, hydrocolloid films consisting of VCN-2 formulations are suitably used as a potential wound dressing to promote restoration of wound injury.
Effect of diacylglycerol interfacial crystallization on the physical stability of water-in-oil emulsions

Yang J, Qiu C, Li G, Lee WJ, Tan CP, Lai OM, et al.

Food Chem, 2020 Oct 15;327:127014.
PMID: 32434126 DOI: 10.1016/j.foodchem.2020.127014

The influence of diacylglycerol (DAG) combined with polyglycerol polyricinoleate (PGPR) on the stability of water-in-oil (W/O) emulsions containing hydrogenated palm oil (HPO) was studied. Polarized light microscope revealed that DAG promoted HPO to crystallize at the water-oil interface, providing the combination of Pickering and network stabilization effects. It was proposed that the molecular compatibility of fatty acids in DAG with HPO accounted for the promotional effect. The interfacial crystallization of DAG together with the surface activity of PGPR led to the formation of emulsions with uniform small droplets and high freeze-thaw stability. Further exploration of physical properties indicated that the combination of DAG and PGPR dramatically improved the emulsion's viscoelasticity and obtained a larger deformation yield. Water droplets in DAG-based emulsions acted as active fillers to improve the network rigidity. Therefore, DAG is a promising material to be used as emulsifier to enhance the physical stability of W/O emulsions.

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