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Fulltext Washout Ratio in the Hepatic Vein Measured by Contrast-Enhanced Ultrasonography to Distinguish Between Inflammatory and Noninflammatory Hepatic Disorders in Dogs

Morishita K, Hiramoto A, Michishita A, Takagi S, Osuga T, Lim SY, et al.

J. Vet. Intern. Med., 2017 May;31(3):770-777.
PMID: 28382699 DOI: 10.1111/jvim.14685

BACKGROUND: Perflubutane microbubbles, a second-generation ultrasound contrast agent, are phagocytized by Kupffer cells. This characteristic may be useful to differentiate diffuse hepatic diseases in dogs.
HYPOTHESIS/OBJECTIVES: To determine whether the washout ratio in the hepatic vein (HV) measured by contrast-enhanced ultrasonography (CEUS) can distinguish between inflammatory and noninflammatory hepatic disorders in dogs.
ANIMALS: Forty-one client-owned dogs with hepatic disorders including 14 with hepatitis, 7 with primary hypoplasia of the portal vein (PHPV), 9 with congenital portosystemic shunt (cPSS), and 11 with other hepatopathy were enrolled. Six dogs without hepatic disease also were evaluated as healthy controls.
METHODS: Dogs with hepatic disorders were prospectively included. Contrast-enhanced ultrasonography of the HV was performed for 2 minutes. Washout ratio was defined as the attenuation rate from peak intensity to the intensity at the end of the CEUS study.
RESULTS: Washout ratio in the hepatitis group (median, 18.0%; range, 2.0-37.0%) was significantly lower than that of the PHPV (median, 52.2%; range, 11.5-86.3%), cPSS (median, 60.0%; range, 28.6-77.4%), other hepatopathy (median, 70.5%; range, 26.6-88.4%), and normal (median, 78.0%; range, 60.7-91.7%) groups. The area under the receiver operating characteristic curve for hepatitis was 0.960, with a 95% confidence interval (CI) of 0.853-0.990. Washout ratio ≤37.1% resulted in a sensitivity of 100% (95% CI, 78.5-100%) and specificity of 85.2% (95% CI, 67.5-94.1%) for the prediction of hepatitis.
CONCLUSIONS AND CLINICAL IMPORTANCE: Washout ratio can distinguish hepatitis from the other noninflammatory disorders with high accuracy. This result might reflect impaired Kupffer cell phagocytosis in dogs with hepatitis.
Early experience with the copper 7, copper T220C and multiload 250 intrauterine devices

Goh TH, Tan CH, Lim SM, Chew SC, Hutapea H, Iskandar J

Med J Malaysia, 1978 Jun;32(4):304-7.
PMID: 732628
Fulltext Carbimazole-induced aplastic anaemia - a case report

Vijay AP, Lim SS, Tan ATB, Rokiah P, Chan SP

JUMMEC, 2009;12(2):92-95.
MyJurnal

Antithyroid drugs have been used for more than 50 years for the management of hyperthyroidism. Most patients tolerate treatment well, but some may develop rare life threatening side effects such as agranulocytosis and aplastic anaemia. Clinical experience with the latter condition is extremely limited. We report on a case of carbimazole-induced aplastic anaemia caused by hypocellular bone marrow and associated plasmacytosis in a thyrotoxic patient chronically treated with carbimazole. This resolved after substitution with propylthiouracil. The clinical course was complicated by neutropaenic septicaemia and atrial fibrillation.
Study site: University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
Low-dissolved-oxygen nitrification in tropical sewage: an investigation on potential, performance and functional microbial community

How SW, Lim SY, Lim PB, Aris AM, Ngoh GC, Curtis TP, et al.

Water Sci Technol, 2018 May;77(9-10):2274-2283.
PMID: 29757179 DOI: 10.2166/wst.2018.143

Intensive aeration for nitrification is a major energy consumer in sewage treatment plants (STPs). Low-dissolved-oxygen (low-DO) nitrification has the potential to lower the aeration demand. However, the applicability of low-DO nitrification in the tropical climate is not well-understood. In this study, the potential of low-DO nitrification in tropical setting was first examined using batch kinetic experiments. Subsequently, the performance of low-DO nitrification was investigated in a laboratory-scale sequential batch reactor (SBR) for 42 days using real tropical sewage. The batch kinetic experiments showed that the seed sludge has a relatively high oxygen affinity. Thus, the rate of nitrification was not significantly reduced at low DO concentrations (0.5 mg/L). During the operation of the low-DO nitrification SBR, 90% of NH4-N was removed. The active low-DO nitrification was mainly attributed to the limited biodegradable organics in the sewage. Fluorescence in-situ hybridisation and 16S rRNA amplicon sequencing revealed the nitrifiers were related to Nitrospira genus and Nitrosomonadaceae family. Phylogenetic analysis suggests 47% of the operational taxonomic units in Nitrospira genus are closely related to a comammox bacteria. This study has demonstrated active low-DO nitrification in tropical setting, which is a more sustainable process that could significantly reduce the energy footprint of STPs.
Fulltext Rare presentation of idiopathic duodenoduodenal intussusception

Loo GH, Mohamad Abu Zeid WM, Lim SL, Ismail AM

Ann R Coll Surg Engl, 2017 Jul;99(6):e188-e190.
PMID: 28660832 DOI: 10.1308/rcsann.2017.0104

Enteroenteric intussusception is a condition in which the full-thickness bowel wall becomes telescoped into the lumen of distal bowel. Intussusception in adult occurs infrequently and varies from childhood intussusception, particularly in its presentation, aetiology and treatment. Duodenoduodenal intussusception is rare because the duodenum is fixed in the retroperitoneal position. It usually occurs secondary to tumour, lipoma, Brunner's gland hamartomatous polyp or adenoma. The diagnosis in adults is usually made at laparotomy, where presentation is with intestinal obstruction. In non-emergency presentation, it may be difficult to arrive at an accurate diagnosis as symptoms may be vague, self-limiting intermittent abdominal pain. Clinical examinations and investigations may not be conclusive and another working diagnosis such as irritable bowel syndrome would be made. We describe a case where a patient initially presented with symptoms mimicking pancreatitis but his symptoms persisted over the course of 2 weeks. When a laparotomy was performed, duodenoduodenal intussusception was discovered and confirmed with histopathology. In this case, a discernible leading point could not be identified.
HPTLC based approach for bioassay-guided evaluation of antidiabetic and neuroprotective effects of eight essential oils of the Lamiaceae family plants

Romero Rocamora C, Ramasamy K, Meng Lim S, Majeed ABA, Agatonovic-Kustrin S

J Pharm Biomed Anal, 2020 Jan 30;178:112909.
PMID: 31618702 DOI: 10.1016/j.jpba.2019.112909

A high-performance thin-layer chromatography (HPTLC) method combined with effect-directed-analysis (EDA) was developed to screen the antioxidant, neuroprotective and antidiabetic effects in essential oils derived from lavender flower, lemon myrtle, oregano, peppermint, sage, and rosemary leaves (Lamiaceae family). HPTLC hyphenated with microchemical (DPPH•, p-anisaldehyde, and ferric chloride) derivatizations, was used to evaluate antioxidant activity, presence of phytosterols and terpenoids, and polyphenolic content, while the combination with biochemical (α-amylase and acetylcholine esterase (AChE) enzymatic) derivatizations was used to asses α-amylase and AChE inhibitory activities. The superior antioxidant activity of oregano leaf extract is attributed to the presence of high levels of aromatic compounds, like polyphenolic acids. The strongest α-amylase inhibition was observed in lemon myrtle and rosemary plus extracts due to the presence of monoterpenes. Rosemary and sage extracts exhibit the highest AChE inhibition activity, with 1 μL essential oils being more potent than the recommended daily dose of donepezil. This superior neuroprotection was attributed to the presences of di- and triterpenes that displayed strong AChE inhibition and antioxidant potential in DPPH• free radical assay. Antioxidant activity was related to phenolic content (R = 0.49), while α-amylase inhibitory activity was positively related to antioxidant activity (R = 0.20) and terpenoid/sterol content (R = 0.31). AChE inhibitory activity was correlated (R = 0.80) to the combined effect of phenolics and terpenoids. Thus, the superior AChE inhibitory and neuroprotection potential of rosemary and sage essential oils could be attributed to joint effects of main phenolic and terpene constituents. The hyphenated HPTLC method provided rapid bioanalytical profiling of highly complex essential oil samples.
A 5-year retrospective study of melioidosis cases treated in a district specialist hospital

Tang RY, Lim SH, Lam JE, Nurasykin S, Eileen T, Chan YW

Med J Malaysia, 2019 12;74(6):472-476.
PMID: 31929471

INTRODUCTION: Melioidosis is caused by Burkholderia pseudomallei, a gram-negative aerobic bacillus, found in the soil and surface water. Treating melioidosis has been a challenge in district hospitals due to high usage of broad spectrum antibiotics and prolonged hospitalisation. This study is to review the patients' demography, clinical presentations and microbiological data.
METHODS: A 5-year retrospective study was carried out on patients admitted with culture positive for melioidosis from year 2013 to 2017 in Hospital Teluk Intan, Perak.
RESULTS: There were a total of 46 confirmed cases of melioidosis. Majority of the patients were working in the agricultural and farming (28.6%), and factories (25.7%). Thirty-one patients had diabetes mellitus (71.1%). Presentations of patients with melioidosis included pneumonia (54.3%), skin and soft tissue infection (19.6%), deep abscesses (15.2%) and bone and joint infections (13%). An average of 5.8 days was needed to confirm the diagnosis of melioidosis via positive culture. However, only 39.4% of these patients were started on ceftazidime or carbapenem as the empirical therapy. The intensive care unit (ICU) admission rate for melioidosis was 46% and the mortality rate was 52%. Our microbial cultures showed good sensitivity towards cotrimoxazole (97.1%), ceftazidime (100%) and carbapenem (100%).
CONCLUSION: Melioidosis carries high mortality rate, especially with lung involvement and bacteremia. Physicians should have high clinical suspicion for melioidosis cases to give appropriate antimelioidosis therapy early.
Persistent thrombocytopenia following dengue fever: What should we do?

Boo YL, Lim SY, P'ng HS, Liam C, Huan NC

Malays Fam Physician, 2019;14(3):71-73.
PMID: 32175045

Thrombocytopenia is a common laboratory finding in dengue infection. However, it usually resolves as the patient recovers from the infection. Persistent thrombocytopenia following dengue infection requires further investigation. Here, we present a case of immune thrombocytopenic purpura (ITP) following dengue infection complicated by intracranial bleeding.
Synthesis of renewable heterogeneous acid catalyst from oil palm empty fruit bunch for glycerol-free biodiesel production

Wong WY, Lim S, Pang YL, Shuit SH, Chen WH, Lee KT

Sci Total Environ, 2020 Jul 20;727:138534.
PMID: 32334218 DOI: 10.1016/j.scitotenv.2020.138534

Interest in biodiesel research has escalated over the years due to dwindling fossil fuel reserves. The implementation of a carbon-based solid acid catalyst in biodiesel production eradicates the separation problems associated with homogeneous catalysis. However, its application in the glycerol-free interesterification process for biodiesel production is still rarely being studied in the literature. In this study, novel environmentally benign catalysts were prepared from oil palm empty fruit bunch (OPEFB) derived activated carbon (AC) which is sustainable and low cost via direct sulfonation using concentrated sulfuric acid. The effects of synthesizing variables such as carbonization and sulfonation temperatures with different holding times towards the fatty acid methyl ester (FAME) yield in interesterification reaction with oleic acid and methyl acetate were investigated in detail. It was found that the optimum carbonization temperature and duration together with sulfonation temperature and duration were 600 °C, 3 h, 100 °C and 6 h, respectively. The catalyst possessed an amorphous structure with a high total acid density of 9.0 mmol NaOH g-1 due to the well-developed porous framework structure of the carbon support. Under these optimum conditions, the OPEFB derived solid acid catalyst recorded an excellent catalytic activity of 50.5% methyl oleate yield at 100 °C after 8 h with 50:1 methyl acetate to oleic acid molar ratio and 10 wt% catalyst dosage. The heterogeneous acid catalyst derived from OPEFB had shown promising properties that made them highly suitable for cost-effective and environmental-friendly glycerol-free biodiesel production.
Fulltext Role of Oil Palm Empty Fruit Bunch-Derived Cellulose in Improving the Sonocatalytic Activity of Silver-Doped Titanium Dioxide

Chai YD, Pang YL, Lim S, Chong WC, Lai CW, Abdullah AZ

Polymers (Basel), 2021 Oct 14;13(20).
PMID: 34685289 DOI: 10.3390/polym13203530

In this study, a novel cellulose/Ag/TiO2 nanocomposite was successfully synthesized via the hydrothermal method. The cellulose extracted from oil palm empty fruit bunch (OPEFB) could address the disposal issue created by OPEFB biomass. Characterization studies such as FESEM, EDX, HRTEM, XRD, FTIR, UV-Vis DRS, PL, XPS, and surface analysis were conducted. It was observed that the incorporation of cellulose could hinder the agglomeration, reduce the band gap energy to 3 eV, increase the specific surface area to 150.22 m3/g, and lower the recombination rate of the generated electron-hole pairs compared to Ag/TiO2 nanoparticles. The excellent properties enhance the sonocatalytic degradation efficiency of 10 mg/L Congo red (up to 81.3% after 10 min ultrasonic irradiation) in the presence of 0.5 g/L cellulose/Ag/TiO2 at 24 kHz and 280 W. The improvement of catalytic activity was due to the surface plasmon resonance effect of Ag and numerous hydroxyl groups on cellulose that capture the holes, which delay the recombination rate of the charge carriers in TiO2. This study demonstrated an alternative approach in the development of an efficient sonocatalyst for the sonocatalytic degradation of Congo red.
Homeostasis model assessment in a population with mixed ethnicity: the 1992 Singapore National Health Survey

Tai ES, Lim SC, Chew SK, Tan BY, Tan CE

Diabetes Res Clin Pract, 2000 Aug;49(2-3):159-68.
PMID: 10963828 DOI: 10.1016/s0168-8227(00)00152-2

We studied insulin resistance and beta-cell function with reference to ethnic group, glucose tolerance and other coronary artery disease risk factors in a cross section of the Singapore population which comprises Chinese, Malays and Asian Indians. 3568 individuals aged 18-69 were examined. Blood pressure, anthropometric data, blood lipids, glucose and insulin were assayed in the fasting state. Glucose and serum insulin were measured 2 h after an oral glucose challenge. Insulin resistance and beta-cell function were calculated using homeostasis model assessment. Asian Indians had higher insulin resistance than Chinese or Malays. Impaired glucose tolerance (IGT) and diabetes mellitus (DM) were associated with greater insulin resistance and impaired beta-cell function compared to normal glucose tolerance (NGT). Insulin resistance was positively correlated with blood pressure in women and total cholesterol, LDL cholesterol and triglyceride in both men and women. It was negatively correlated with HDL cholesterol and LDL/apolipoprotein B ratio. beta-cell function showed no significant correlations with the cardiovascular risk factors studied. It appears that both impaired beta-cell function and insulin resistance are important for the development of hyperglycemia whereas insulin resistance alone seems more important in the development of coronary artery disease as it correlates with several known coronary artery disease risk factors.
Semi-mechanistic PK/PD modelling of meropenem and sulbactam combination against carbapenem-resistant strains of Acinetobacter baumannii

Mohd Sazlly Lim S, Heffernan AJ, Zowawi HM, Roberts JA, Sime FB

Eur J Clin Microbiol Infect Dis, 2021 Sep;40(9):1943-1952.
PMID: 33884516 DOI: 10.1007/s10096-021-04252-z

Due to limited treatment options for carbapenem-resistant Acinetobacter baumannii (CR-AB) infections, antibiotic combinations are commonly used. In this study, we explored the potential efficacy of meropenem-sulbactam combination (MEM/SUL) against CR-AB. The checkerboard method was used to screen for synergistic activity of MEM/SUL against 50 clinical CR-AB isolates. Subsequently, time-kill studies against two CR-AB isolates were performed. Time-kill data were described using a semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model. Subsequently, Monte Carlo simulations were performed to estimate the probability of 2-log kill, 1-log kill or stasis at 24-h following combination therapy. The MEM/SUL demonstrated synergy against 28/50 isolates. No antagonism was observed. The MIC50 and MIC90 of MEM/SUL were decreased fourfold, compared to the monotherapy MIC. In the time-kill studies, the combination displayed synergistic killing against both isolates at the highest clinically achievable concentrations. At concentrations equal to the fractional inhibitory concentration, synergism was observed against one isolate. The PK/PD model adequately delineated the data and the interaction between meropenem and sulbactam. The effect of the combination was driven by sulbactam, with meropenem acting as a potentiator. The simulations of various dosing regimens revealed no activity for the monotherapies. At best, the MEM/SUL regimen of 2 g/4 g every 8 h demonstrated a probability of target attainment of 2-log10 kill at 24 h of 34%. The reduction in the MIC values and the achievement of a moderate PTA of a 2-log10 reduction in bacterial burden demonstrated that MEM/SUL may potentially be effective against some CR-AB infections.
Fulltext Rapid Ultrasound-Assisted Starch Extraction from Sago Pith Waste (SPW) for the Fabrication of Sustainable Bioplastic Film

Tan SX, Andriyana A, Lim S, Ong HC, Pang YL, Ngoh GC

Polymers (Basel), 2021 Dec 15;13(24).
PMID: 34960953 DOI: 10.3390/polym13244398

The present study was conducted to optimize the extraction yield of starch from sago (Metroxylon sagu) pith waste (SPW) with the assistance of ultrasound ensued by the transformation of extracted starch into a higher value-added bioplastic film. Sago starch with extraction yield of 71.4% was successfully obtained using the ultrasound-assisted extraction, with the following conditions: particle size <250 µm, solid loading of 10 wt.%, ultrasonic amplitude of 70% and duty cycle of 83% in 5 min. The rapid ultrasound approach was proven to be more effective than the conventional extraction with 60.9% extraction yield in 30 min. Ultrasound-extracted starch was found to exhibit higher starch purity than the control starch as indicated by the presence of lower protein and ash contents. The starch granules were found to have irregular and disrupted surfaces after ultrasonication. The disrupted starch granules reduced the particle size and increased the swelling power of starch which was beneficial in producing a film-forming solution. The ultrasound-extracted sago starch was subsequently used to prepare a bioplastic film via solution casting method. A brownish bioplastic film with tensile strength of 0.9 ± 0.1 MPa, Young's modulus of 22 ± 0.8 MPa, elongation at break of 13.6 ± 2.0% and water vapour permeability (WVP) of 1.11 ± 0.1 × 10-8 g m-1 s-1 Pa-1 was obtained, suggesting its feasibility as bioplastic material. These findings provide a means of utilization for SPW which is in line with the contemporary trend towards greener and sustainable products and processes.
Fulltext Characterization and Parametric Study on Mechanical Properties Enhancement in Biodegradable Chitosan-Reinforced Starch-Based Bioplastic Film

Tan SX, Ong HC, Andriyana A, Lim S, Pang YL, Kusumo F, et al.

Polymers (Basel), 2022 Jan 11;14(2).
PMID: 35054685 DOI: 10.3390/polym14020278

Bioplastic has been perceived as a promising candidate to replace petroleum-based plastics due to its environment-friendly and biodegradable characteristics. This study presents the chitosan reinforced starch-based bioplastic film prepared by the solution casting and evaporation method. The effects of processing parameters, i.e., starch concentration, glycerol loading, process temperature and chitosan loading on mechanical properties were examined. Optimum tensile strength of 5.19 MPa and elongation at break of 44.6% were obtained under the combined reaction conditions of 5 wt.% starch concentration, 40 wt.% glycerol loading, 20 wt.% chitosan loading and at a process temperature of 70 °C. From the artificial neural network (ANN) modeling, the coefficient of determination (R2) for tensile strength and elongation at break were found to be 0.9955 and 0.9859, respectively, which proved the model had good fit with the experimental data. Interaction and miscibility between starch and chitosan were proven through the peaks shifting to a lower wavenumber in FTIR and a reduction of crystallinity in XRD. TGA results suggested the chitosan-reinforced starch-based bioplastic possessed reasonable thermal stability under 290 °C. Enhancement in water resistance of chitosan-incorporated starch-based bioplastic film was evidenced with a water uptake of 251% as compared to a 302% registered by the pure starch-based bioplastic film. In addition, the fact that the chitosan-reinforced starch-based bioplastic film degraded to 52.1% of its initial weight after 28 days suggests it is a more sustainable alternative than the petroleum-based plastics.
Determination of the 99th percentile upper reference limit for high-sensitivity cardiac troponin I in Malaysian population

Lim SM, Thambiah SC, Zahari Sham SY, Omar R, Hambali Z, Samsudin IN

Malays J Pathol, 2017 Aug;39(2):135-140.
PMID: 28866694

Introduction of high-sensitivity cardiac troponin I (hscTn I) assays for routine clinical use in Malaysia requires determination of the 99(th) percentile upper reference limit (URL) for each assay to suit local context. Hence, this study aimed to determine the 99(th) percentile URL for hscTn I in the Malaysian population. A total of 250 (120 males and 130 females) healthy Malaysian blood donors aged 18 to 60 years old were recruited. Blood samples for hscTn I were measured using Abbott Diagnostics hscTn I assay on Architect i2000sr analyser. The 99(th) percentile was calculated using a non-parametric method and gender specific results were compared. The 99(th) percentile URL for hscTn I for the overall population was 23.7 ng/L, with gender specific values being 29.9 ng/L and 18.6 ng/L for male and female, respectively. Females had significantly lower hscTn I compared to males. This study confirms the use of gender specific 99(th) percentile URL for hscTn I for clinical use in a multi-ethnic Malaysian population.
Pulmonary actinomycosis masquerading as lung cancer: A case report

Boo YL, How KN, Pereira DS, Chin PW, Foong KK, Lim SY

Med J Malaysia, 2017 08;72(4):246-247.
PMID: 28889138 MyJurnal

Pulmonary actinomycosis is a rare yet important and challenging diagnosis to make. It is commonly confused with other lung diseases, such as tuberculosis and bronchogenic carcinoma, leading to delay diagnosis or misdiagnosis. A 49-year-old man presented with a chronic cough, hemoptysis, and pleuritic chest pain. His initial imaging studies including computed tomography (CT) was suggestive of bronchogenic carcinoma. A subsequent CTguided biopsy was consistent with pulmonary actinomycosis and excluded the possibility of bronchogenic carcinoma. He was treated with antibiotic therapy and achieved remission with complete radiological resolution upon follow-up.
Fluctuation of BCR-ABL1 qPCRIS level beyond 0.1%IS after stopping tyrosine kinase inhibitor in chronic myeloid leukaemia patients with deep molecular response for at least two years

Kuan JW, Chang KM, Phan CL, Wong SP, Lim SM, Toh SG, et al.

Med J Malaysia, 2021 May;76(3):414-416.
PMID: 34031342

Fluctuation of BCR-ABL1 real-time quantitative polymerase chain reaction in International Scale (qPCRIS) level below major molecular response (MMR) (0.1%IS) is a known phenomenon after stopping tyrosine kinase inhibitor (TKI) in chronic myeloid leukaemia (CML) patients who are attempting treatment free remission (TFR). We report here four cases of fluctuation beyond MMR during conduct of a Malaysia Stop TKI Trial (MSIT) to examine the validity of the commonly used relapse criterion - loss of MMR for one reading - aiming to provide evidence in setting relapse criteria for future CML patients who want to attempt TFR.
Enhanced photocatalytic degradation of methyl orange by coconut shell-derived biochar composites under visible LED light irradiation

Pang YL, Law ZX, Lim S, Chan YY, Shuit SH, Chong WC, et al.

Environ Sci Pollut Res Int, 2021 Jun;28(21):27457-27473.
PMID: 33507503 DOI: 10.1007/s11356-020-12251-4

The conversion of carbon-rich biomass into valuable material is an environmental-friendly approach for its reutilization. In this study, coconut shell-derived biochar, graphitic carbon nitride (g-C3N4), g-C3N4/biochar, titanium dioxide (TiO2)/biochar, zinc oxide (ZnO)/biochar, and ferric oxide (Fe2O3)/biochar were synthesized and characterized by using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), surface area analysis, UV-Vis diffuse reflectance spectroscopy (DRS), and zeta potential analysis. The g-C3N4 or metal oxide particles were found to be well-distributed on the coconut shell-derived biochar with the improvement in thermal stability and enlargement of specific surface area. A great reduction in band gap energy was observed in the composite materials after incorporating with the biochar. Among different biochar composites, g-C3N4/biochar was found to have the highest photocatalytic activity. The interactive effect of parameters such as catalyst dosage, peroxymonosulfate (PMS) oxidant dosage, and solution pH on the photocatalytic degradation of methyl orange was investigated using the response surface methodology (RSM). The highest photocatalytic degradation efficiency (96.63%) was achieved at catalyst dosage of 0.75 g/L, oxidant dosage of 0.6 mM, and solution pH 3 after 30 min.
Biosynthesized Fe- and Ag-doped ZnO nanoparticles using aqueous extract of Clitoria ternatea Linn for enhancement of sonocatalytic degradation of Congo red

Chan YY, Pang YL, Lim S, Lai CW, Abdullah AZ, Chong WC

Environ Sci Pollut Res Int, 2020 Oct;27(28):34675-34691.
PMID: 31628641 DOI: 10.1007/s11356-019-06583-z

Nowadays, the current synthesis techniques used in industrial production of nanoparticles have been generally regarded as nonenvironmentally friendly. Consequently, the biosynthesis approach has been proposed as an alternative to reduce the usage of hazardous chemical compounds and harsh reaction conditions in the production of nanoparticles. In this work, pure, iron (Fe)-doped and silver (Ag)-doped zinc oxide (ZnO) nanoparticles were successfully synthesized through the green route using Clitoria ternatea Linn. The optical, chemical, and physical properties of the biosynthesized ZnO nanoparticles were then analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), UV-Vis diffuse reflectance spectroscopy (DRS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and surface analysis. The biosynthesized ZnO nanoparticles were crystallized with a hexagonal wurtzite structure and possessed smaller particle sizes than those of commercially or chemically produced samples. The existence of biomolecules to act as reducing and stabilizing agents from C. ternatea Linn aqueous extract was confirmed using FTIR analysis. The biosynthesized ZnO nanoparticles mainly comprised of negatively charged groups and responsible for moderately stable dispersion of the nanoparticles. All these properties were favorable for the sonocatalytic degradation of Congo red. Sonocatalytic activity of ZnO nanoparticles was studied through the degradation of 10 mg/L Congo red using ultrasonic irradiation at 45 kHz and 80 W. The results showed that the sonocatalytic degradation efficiency of Congo red in the presence of biosynthesized ZnO nanoparticles prepared at 50 °C for 1 h could achieve 88.76% after 1 h. The sonocatalytic degradation efficiency of Congo red in the presence of Ag-doped ZnO was accelerated to 94.42% after 10 min which might be related to the smallest band gap energy (3.02 eV) and the highest specific surface area (10.31 m2/g) as well as pore volume (0.0781 cm3/g). Lastly, the biosynthesized ZnO nanoparticles especially Ag-doped ZnO offered significant antibacterial potential against Escherichia coli which indicated its ability to inhibit the normal growth and replication of bacterial cells. These results affirmed that the biosynthesized ZnO nanoparticles could be used as an alternative to the current chemical compounds and showed a superior sonocatalytic activity toward degradation of Congo red.
Factors related to prehospital delay and decision delay among acute stroke patients in a district hospital, Malaysia

Lim SH, Tan TL, Ngo PW, Lee LY, Ting SY, Tan HJ

Med J Malaysia, 2023 Mar;78(2):241-249.
PMID: 36988537

INTRODUCTION: Time is the greatest challenge in stroke management. This study aimed to examine factors contributing to prehospital delay and decision delay among stroke patients.
MATERIALS AND METHODS: A cross-sectional study involving acute stroke patients admitted to Seri Manjung Hospital was conducted between August 2019 and October 2020 via faceto- face interview. Prehospital delay was defined as more than 120 minutes taken from recognition of stroke symptoms till arrival in hospital, while decision delay was defined as more than 60 minutes taken from recognition of stroke symptoms till decision was made to seek treatment.
RESULTS: The median prehospital delay of 102 enrolled patients was 364 minutes (IQR 151.5, 1134.3) while the median for decision delay was 120 minutes (IQR 30.0, 675.0). No history of stroke (adj. OR 4.15; 95% CI 1.21, 14.25; p=0.024) and unaware of thrombolysis service (adj. OR 17.12; 95% CI 1.28, 229.17; p=0.032) were associated with higher odds of prehospital delay, while Indian ethnicity (adj. OR 0.09; 95% CI 0.02, 0.52; p=0.007) was associated with lower odds of prehospital delay as compared to Malay ethnicity. On the other hand, higher National Institutes of Health Stroke Scale (NIHSS) score (adj. OR 0.86; 95% CI 0.78, 0.95; p=0.002) was associated with lower odds of decision delay.
CONCLUSION: Public awareness is crucial to shorten prehosital delay and decision delay for better patients' outcomes in stroke. Various public health campaigns are needed to improve the awareness for stroke.

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