Displaying publications 1 - 20 of 31 in total

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  1. Huang L, Ahmad NH, Juneja V, Stapp-Kamotani E, Gabiola J, Minocha U, et al.
    Food Microbiol, 2024 Apr;118:104420.
    PMID: 38049265 DOI: 10.1016/j.fm.2023.104420
    During commercial production of liquid egg yolk (LEY), phospholipase A2 (PLA2) is used to improve its emulsification capacity and thermal stability. The enzymatic treatment may occur at elevated temperatures such as 50 °C, potentially allowing foodborne pathogens, such as Bacillus cereus, to grow. Little knowledge is available concerning growth of B. cereus in LEY during PLA2 treatment. Therefore, the objective of this study was to investigate the growth kinetics of B. cereus during PLA2 treatment using pathogenic B. cytotoxicus NVH391-98, the most thermotolerant member in the B. cereus group, as a surrogate. Inoculated LEY samples were placed in precision programmable incubators to observe the growth of B. cytotoxicus NVH391-98 under multiple isothermal and dynamic temperature conditions between 20 and 53 °C. The bacterial growth was described using the differential Baranyi model coupled with two different secondary models. The kinetic parameters were determined using one-step dynamic inverse analysis of multiple growth curves. The least square method was used in combination with the 4th order Runge-Kutta method to solve the differential Baranyi model using multiple growth curves to determine the cardinal kinetic parameters. The results showed that B. cytotoxicus NVH391-98 can grow prolifically at 50 °C. The estimated minimum, optimum and maximum temperatures were 16.7 or 18.5, 47.8 or 48.1, and 52.1 or 52.4 °C, respectively, depending on the secondary models, with an optimum growth rate of 2.1 log colony-forming-unit (CFU)/g per hour. The dynamic model is validated using isothermal curves with reasonable accuracy. B. cytotoxicus died off slowly at 15 °C. At 55 °C, thermal inactivation was observed, with a D value of approximately 2.7 h. Holding at 55 °C or below 15 °C can effectively prevent the growth of B. cytotoxicus in egg yolk.
  2. Oslan SNH, Yusof NY, Lim SJ, Ahmad NH
    J Microbiol Methods, 2024 Apr;219:106897.
    PMID: 38342249 DOI: 10.1016/j.mimet.2024.106897
    Salmonella is as an intracellular bacterium, causing many human fatalities when the host-specific serotypes reach the host gastrointestinal tract. Nontyphoidal Salmonella are responsible for numerous foodborne outbreaks and product recalls worldwide whereas typhoidal Salmonella are responsible for Typhoid fever cases in developing countries. Yet, Salmonella-related foodborne disease outbreaks through its food and water contaminations have urged the advancement of rapid and sensitive Salmonella-detecting methods for public health protection. While conventional detection methods are time-consuming and ineffective for monitoring foodstuffs with short shelf lives, advances in microbiology, molecular biology and biosensor methods have hastened the detection. Here, the review discusses Salmonella pathogenic mechanisms and its detection technology advancements (fundamental concepts, features, implementations, efficiency, benefits, limitations and prospects). The time-efficiency of each rapid test method is discussed in relation to their limit of detections (LODs) and time required from sample enrichment to final data analysis. Importantly, the matrix effects (LODs and sample enrichments) were compared within the methods to potentially speculate Salmonella detection from environmental, clinical or food matrices using certain techniques. Although biotechnological advancements have led to various time-efficient Salmonella-detecting techniques, one should consider the usage of sophisticated equipment to run the analysis by moderately to highly trained personnel. Ultimately, a fast, accurate Salmonella screening that is readily executed by untrained personnels from various matrices, is desired for public health procurement.
  3. Mohammed NK, Ahmad NH, Muhialdin BJ, Meor Hussin AS
    J Food Sci Technol, 2024 Mar;61(3):528-538.
    PMID: 38327854 DOI: 10.1007/s13197-023-05860-7
    This work aims to produce a virgin coconut oil (VCO) creamer through two drying stages; spray drying followed by fluidised bed drying, and to examine its antioxidant properties and oxidative stability during different storage conditions. Evaluation of the physicochemical properties of spray dry VCO and oxidative stability of the VCO creamer were performed using peroxide value (PV), antioxidant activity (DPPH), and total phenolic content (TPC) at 25, 4, and 25 °C, respectively, for 8 weeks. Agglomeration process has improved the agglomerated VCO creamer's properties in terms of moisture content (4.34%), solubility (85.2%), water activity (0.32%), and bulk density (0.36 g/cm3). The morphology of agglomerated VCO creamer showed cluster and irregular shapes with enlargement in the particle size, (d32) 395 µm and (d43) 426 µm. The overall oxidative results showed stability for the agglomerated VCO creamer stored at 4 °C in terms of TPC, DPPH and PV over 8 weeks followed by creamer stored at 25 °C which had similar stability with slight differences. The creamer stored at 38 °C showed rapid degradation for all oxidation tests from week 2 onwards. Agglomeration technology has indicated to be effective in the stabilization of virgin coconut oil against lipid oxidation and prolonging its shelf-life.
  4. Zhou X, Yan Z, Hou J, Zhang L, Chen Z, Gao C, et al.
    Oncogene, 2024 Feb;43(7):495-510.
    PMID: 38168654 DOI: 10.1038/s41388-023-02923-z
    Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies in the world with poor prognosis. Despite the promising applications of immunotherapy, the objective response rate is still unsatisfactory. We have previously shown that Hippo/YAP signaling acts as a powerful tumor promoter in ESCC. However, whether Hippo/YAP signaling is involved in tumor immune escape in ESCC remains largely unknown. Here, we show that YAP directly activates transcription of the "don't eat me" signal CD24, and plays a crucial role in driving tumor cells to avoid phagocytosis by macrophages. Mechanistically, YAP regulates CD24 expression by interacting with TEAD and binding the CD24 promoter to initiate transcription, which facilitates tumor cell escape from macrophage-mediated immune attack. Our animal model data and clinical data show that YAP combined with CD24 in tumor microenvironment redefines the impact of TAMs on the prognosis of ESCC patients which will provide a valuable basis for precision medicine. Moreover, treatment with YAP inhibitor altered the distribution of macrophages and suppressed tumorigenesis and progression of ESCC in vivo. Together, our study provides a novel link between Hippo/YAP signaling and macrophage-mediated immune escape, which suggests that the Hippo-YAP-CD24 axis may act as a promising target to improve the prognosis of ESCC patients. A proposed model for the regulatory mechanism of Hippo-YAP-CD24-signaling axis in the tumor-associated macrophages mediated immune escape.
  5. Ahmad NH, Huang L, Juneja V
    Food Res Int, 2024 Jan;176:113786.
    PMID: 38163703 DOI: 10.1016/j.foodres.2023.113786
    Liquid egg yolk (LEY) is often treated with phospholipase A2 (PLA2) to improve its emulsifying capacity and thermal stability. However, this process may allow certain pathogens to grow. The objective of this study was to evaluate the growth kinetics of mesophilic Bacillus cereus in LEY during PLA2 treatment. Samples, inoculated with B. cereus vegetative cells, were incubated isothermally at different temperatures between 9 and 50 °C to observe the bacterial growth and survival. Under the observation conditions, bacterial growth occurred between 15 and 48 °C, but not at 9 and 50 °C. The growth curves were analyzed using the USDA IPMP-Global Fit, with the no-lag phase model as the primary model in combination with either the cardinal temperatures model (CTM) or the Huang square-root model (HSRM) as the secondary model. While similar maximum growth temperatures (Tmax) were determined (48.4 °C for HSRM and 48.1 °C for CTM), the minimum growth temperature (Tmin) of the HSRM more accurately described the lower limit (9.26 °C), in contrast to 6.51 °C for CTM, suggesting that the combination of the no-lag phase model and HSRM was more suitable to describe the growth of mesophilic B. cereus in LEY. The root mean square error (RMSE) of model validation and development was <0.5 log CFU/g, indicating the combination of the no-lag phase model and HSRM could predict the growth of mesophilic B. cereus in LEY during PLA2 treatment. The results of this study may allow the food industry to choose a suitable temperature for PLA2 treatment of LEY to prevent the growth of mesophilic B. cereus.
  6. Khan S, Rukayadi Y, Jaafar AH, Ahmad NH
    Heliyon, 2023 Dec;9(12):e22771.
    PMID: 38125456 DOI: 10.1016/j.heliyon.2023.e22771
    Foodborne diseases continue to pose a significant global health concern, causing a considerable number of deaths worldwide. In response to concerns surrounding bacterial resistance and the limitations of traditional antibiotics, there is a growing interest in exploring natural antibacterial agents as potential alternatives for addressing foodborne pathogens. Nowadays efforts are being made on exploring the potential of natural antibacterial agents against foodborne pathogens. In this study, the antibacterial efficacy of silver nanoparticles synthesized using S. polyanthum leaves extract (SP-AgNPs) against selected Gram-negative and Gram-positive foodborne pathogens was investigated by using multiple assays, including the well diffusion assay (WDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assay. The well diffusion assay demonstrated the inhibitory potential of SP-AgNPs against all tested foodborne pathogens, with inhibition zones ranging from 10.16 + 1.25 to 13.16 + 1.52 mm. Furthermore, the MIC values ranged from 0.008 to 0.125 mg/mL, indicating the potent antibacterial activity of SP-AgNPs across a broad spectrum of foodborne pathogens. The MBC values, ranging from 0.008 to 0.250 mg/mL, further confirming the bactericidal ability of SP-AgNPs against these pathogens. In the time-kill experiment, most foodborne pathogens were entirely killed after 4 h of incubation at 4 × MIC concentration. However, only E. coli, K. pneumoniae, and S. Typhimurium showed a reduction in population to 3 Log10 CFU/mL, indicating a strong bactericidal effect of SP-AgNPs on most tested pathogens. In conclusion, this study provides compelling evidence that SP-AgNPs exhibit potent antibacterial activity against selected foodborne pathogens. The findings suggest that SP-AgNPs synthesized using S. polyanthum leaves extract hold great promise as a novel antibacterial agent for effectively controlling foodborne pathogens. These findings contribute to continuing efforts in developing alternative strategies to prevent foodborne diseases and enhance food safety.
  7. Shela V, Ramayah T, Aravindan KL, Ahmad NH, Alzahrani AI
    Heliyon, 2023 Dec;9(12):e22476.
    PMID: 38125546 DOI: 10.1016/j.heliyon.2023.e22476
    Partial least squares structural equation modelling (PLS-SEM) is emerging as a prominent methodological tool in strategic management research. Although it offers various advancements to stay relevant with growing research needs, the pace of PLS-SEM adoption may differ in different parts of the world. In this paper, we conducted a systematic review using the PRISMA framework and extracted from the top-ranking strategic management journals 120 articles published between 2011 and 2022 that presented a microscopic view on developing nations. Our findings reveal that despite the astounding methodological solutions offered by PLS-SEM, the studies from developing nations are still trailing behind developed nations in terms of fully exploiting the advancements of PLS-SEM to provide substantial insights to strategic management literature. This review identifies discrepancies in the current application of the method, discusses the most recent advancements and provides the best practices, standard guidelines and recommendations for the best use of PLS-SEM in strategic management research.
  8. Chen Z, Wang W, Abdul Razak SR, Han T, Ahmad NH, Li X
    Cell Death Dis, 2023 Jul 24;14(7):460.
    PMID: 37488128 DOI: 10.1038/s41419-023-05930-w
    Ferroptosis is a recently discovered essential type of cell death that is mainly characterized by iron overload and lipid peroxidation. Emerging evidence suggests that ferroptosis is a double-edged sword in human cancer. However, the precise underlying molecular mechanisms and their differential roles in tumorigenesis are unclear. Therefore, in this review, we summarize and briefly present the key pathways of ferroptosis, paying special attention to the regulation of ferroptosis as well as its dual role as an oncogenic and as a tumor suppressor event in various human cancers. Moreover, multiple pharmacological ferroptosis activators are summarized, and the prospect of targeting ferroptosis in cancer therapy is further elucidated.
  9. Muthanna A, Desa MNM, Alsalemi W, Liyana Abd Aziz NA, Dzaraly ND, Baharin NHZ, et al.
    PMID: 37167694 DOI: 10.1016/j.cimid.2023.101993
    Group B Streptococcus (GBS) is a major cause of several infectious diseases in humans and fish. This study was conducted to compare human and fish-derived GBS in terms of their antimicrobial susceptibility, serotype, virulence and pili genes and sequence type (ST), and to determine whether there is a potential linkage of zoonotic transmission in Malaysia. GBS isolated from humans and fish had similar phenotypic characteristics and differed in virulence gene profile, antimicrobial susceptibility, serotype and sequence type. Fish GBS isolates had lower genetic diversity and higher antibiotic susceptibility than human isolates. We report a rare detection of the potentially fish-adapted ST283 in human GBS isolates. Both human and fish ST283 shared several phenotypic and genotypic features, including virulence and pilus genes and antimicrobial susceptibility, illustrating the value of monitoring GBS within the One Health scope. In this study, two human GBS ST283 isolates belonging to the variant common in fish hosts were identified, raising awareness of the zoonotic potential between the different species in Malaysia.
  10. Zahari NH, Abd Hamid IJ, Tuan Din SA, Hashim IF, Zainudeen ZT, Mohd Shariff N, et al.
    Malays J Med Sci, 2023 Jun;30(3):112-121.
    PMID: 37425378 DOI: 10.21315/mjms2023.30.3.10
    BACKGROUND: Intravenous immunoglobulin (IVIG) replacement therapy is increasingly in demand. This study focused on the characteristics of IVIG usage and associated factors toward the frequency status of IVIG among patients in Hospital Kuala Lumpur.

    METHODS: A retrospective cross-sectional study was performed on patients who received IVIG in Hospital Kuala Lumpur. Data were extracted from the request forms for IVIG recorded in the Pharmacy Department from January 2018 until December 2019. Chi-squared test and t-test analysis were used for statistical analysis, and a P-value of < 0.05 was considered significant.

    RESULTS: A total of 482 patients received IVIG in Hospital Kuala Lumpur. There were 243 (50.4%) females and 228 (47.3%) males with median age of the patients was 27 years old. The highest indications for IVIG among all patients were hypogammaglobulinemia and other deficiency states in 127 patients (26.3%). The most common indication for one-off treatment in adults was hypogammaglobulinemia and other deficiency states, 35%; whereas in paediatrics, it was Kawasaki disease, 20.3%. The highest indication for regular therapy among adult patients was chronic inflammatory demyelinating polyneuropathy (23.4%), while in paediatrics it was sepsis (31.1%). The clinical category was associated with the frequency status of IVIG usage in both adult and paediatric cohorts with P = 0.004 and P = 0.017, respectively.

    CONCLUSION: There were significant differences between the indication of one-off treatment and regular therapy among adult and paediatric patients. A national guideline on the prescription of IVIG for patients is instantly needed to help clinicians in prescribing IVIG appropriately.

  11. Azhar NA, Abu Bakar SA, Citartan M, Ahmad NH
    World J Hepatol, 2023 Mar 27;15(3):393-409.
    PMID: 37034237 DOI: 10.4254/wjh.v15.i3.393
    BACKGROUND: The demand for the development of cancer nanomedicine has increased due to its great therapeutic value that can overcome the limitations of conventional cancer therapy. However, the presence of various bioactive compounds in crude plant extracts used for the synthesis of silver nanoparticles (AgNPs) makes its precise mechanisms of action unclear.

    AIM: To assessed the mRNA transcriptome profiling of human HepG2 cells exposed to Catharanthus roseus G. Don (C. roseus)-AgNPs.

    METHODS: The proliferative activity of hepatocellular carcinoma (HepG2) and normal human liver (THLE3) cells treated with C. roseusAgNPs were measured using MTT assay. The RNA samples were extracted and sequenced using BGIseq500 platform. This is followed by data filtering, mapping, gene expression analysis, differentially expression genes analysis, Gene Ontology analysis, and pathway analysis.

    RESULTS: The mean IC50 values of C. roseusAgNPs on HepG2 was 4.38 ± 1.59 μg/mL while on THLE3 cells was 800 ± 1.55 μg/mL. Transcriptome profiling revealed an alteration of 296 genes. C. roseusAgNPs induced the expression of stress-associated genes such as MT, HSP and HMOX-1. Cellular signalling pathways were potentially activated through MAPK, TNF and TGF pathways that are responsible for apoptosis and cell cycle arrest. The alteration of ARF6, EHD2, FGFR3, RhoA, EEA1, VPS28, VPS25, and TSG101 indicated the uptake of C. roseus-AgNPs via both clathrin-dependent and clathrin-independent endocytosis.

    CONCLUSION: This study provides new insights into gene expression study of biosynthesised AgNPs on cancer cells. The cytotoxicity effect is mediated by the aberrant gene alteration, and more interestingly the unique selective antiproliferative properties indicate the C. roseusAgNPs as an ideal anticancer candidate.

  12. Mohd Zaini NS, Lim EJ, Ahmad NH, Gengatharan A, Wan-Mohtar WAAQI, Abd Rahim MH
    Food Bioproc Tech, 2023 Feb 20.
    PMID: 36844636 DOI: 10.1007/s11947-023-03020-5
    The processing of edible insects as an alternative source of nutrition may be a key driver in the development of a sustainable food and feed system. This review will study two industrial types of insects-mealworms and locusts-and summarize evidence related to the impact of processing on their micro- and macronutritional characteristics. The focus will be on their potential use as food for human consumption as opposed to animal feed. Literature has indicated that these two insects have the potential to provide protein and fat qualities comparable to or better than traditional mammalian sources. For example, mealworms-the larval form of the yellow mealworm beetlepossess a higher fat content, while adult locusts are rich in fibers, especially chitin. However, due to the different matrix and nutrient compositions, the processing of mealworms or locusts at a commercial scale needs to be tailored to minimize nutritional loss and maximize cost efficiency. The stages of preprocessing, cooking, drying, and extraction are the most critical control points for nutritional preservation. Thermal cooking applications such as microwave technology have demonstrated promising results, but the generation of heat may contribute to a certain nutritional loss. In an industrial context, drying using freeze dry is the preferred choice due to its uniformity, but it can be costly while increasing lipid peroxidation. During the extraction of nutrients, the use of green emerging technologies such as high hydrostatic pressure, pulsed electric field, and ultrasound may provide an alternative method to enhance nutrient preservation.
  13. Pei TP, Ahmad NH, Noor NHM
    Oman Med J, 2022 Jan;37(1):e336.
    PMID: 35136665 DOI: 10.5001/omj.2021.45
    Para-Bombay blood phenotype is a rare blood group with limited cases reported worldwide. This blood group is characterized by the absence of ABH antigen on red blood cells but presence of ABH secretor substances in the body secretion. This rare phenotype is usually misinterpreted as O and may endanger the patient if urgent blood transfusion is required. A mother who was labelled as group O Rh D positive during antenatal follow-up was found to have ABO discrepancy during delivery. The newborn was admitted for extremely premature delivery at 25 weeks. As the baby required transfusion, problem arose during cross matching with the mother's sample. It was found that the mother was group O Rh D positive in forward grouping. However, the reverse grouping showed the presence of reaction (2+) in O cells. The baby was grouped as O Rh D positive. As transfusion was urgently needed due to baby's unstable condition, group O Rh D positive packed cell was found compatible with baby's serum, subsequently transfused. Bombay blood donor was contacted, and the donated blood was sent to the hospital for further management. Further investigations were performed, indicating that the mother is para-Bombay A. Due to recent transfusion to baby, we suggested to repeat baby's blood group after the baby is one year old. Para-Bombay was usually mislabelled as O if the sample was not tested with O cell in reverse grouping. Additional tests may be needed during antenatal follow-up to prevent complications during delivery, which requires emergency blood transfusion.
  14. Chan HY, Meor Hussin AS, Ahmad NH, Rukayadi Y, Farouk AE
    Molecules, 2021 Aug 30;26(17).
    PMID: 34500692 DOI: 10.3390/molecules26175259
    Table eggs are an affordable yet nutritious protein source for humans. Unfortunately, eggs are a vector for bacteria that could cause foodborne illness. This study aimed to investigate the effectiveness of a quaternary ammonium compound (quat) sanitizer against aerobic mesophilic bacteria, yeast, and mold load on the eggshell surface of free-range and commercial farms and the post-treatment effect on microbial load during storage. Total aerobic mesophilic bacteria, yeast, and molds were enumerated using plate count techniques. The efficacy of the quaternary ammonium sanitizer (quat) was tested using two levels: full factorial with two replicates for corner points, factor A (maximum: 200 ppm, minimum: 100 ppm) and factor B (maximum: 15 min, minimum: 5 min). Quat sanitizer significantly (p < 0.05) reduced approximately 4 log10 CFU/cm2 of the aerobic mesophilic bacteria, 1.5 to 2.5 log10 CFU/cm2 of the mold population, and 1.5 to 2 log10 CFU/cm2 of the yeast population. However, there was no significant (p ≥ 0.05) response observed between individual factor levels (maximum and minimum), and two-way interaction terms were also not statistically significant (p ≥ 0.05). A low (<1 log10 CFU/cm2) aerobic mesophilic bacteria trend was observed when shell eggs were stored in a cold environment up to the production expiry date. No internal microbial load was observed; thus, it was postulated that washing with quat sanitizer discreetly (without physically damaging the eggshell) does not facilitate microbial penetration during storage at either room temperature or cold storage. Current study findings demonstrated that the quat sanitizer effectively reduced the microbial population on eggshells without promoting internal microbial growth.
  15. Krishnamoorthy M, Ahmad NH, Amran HN, Mohamed MA, Kaus NHM, Yusoff SFM
    Int J Biol Macromol, 2021 Jul 01;182:1495-1506.
    PMID: 34019924 DOI: 10.1016/j.ijbiomac.2021.05.104
    Semiconductor materials have shown a good photocatalytic behaviour for the photodegradation of organic pollutants. In this work, maleated liquid natural rubber (MLNR) based hydrogel supported bismuth ferrite (BiFeO3) as photocatalyst was successfully synthesized by crosslinking with acrylic acid (AAc) assisted by the ultrasonication method to study the efficiency for the removal of methylene blue (MB) dye in wastewater. Response surface methodology (RSM) was used to optimize the parameters for adsorption of the methylene blue (MB) dye compound, whereby the effects of the initial concentration of MB and the adsorption time were examined to obtain a quadratic model for the respective hydrogel composite. The prepared composite sample was characterized by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) and X-ray Diffraction (XRD) analysis. Remarkable improvement for removal of methylene blue (99% removal) was found within 3 h adsorption time with a MLNR/AAc-BiFeO3 hydrogel composite as compared to the pristine hydrogel. A synergistic mode of dye removal by adsorption and photodegradation is proposed. Based on the isotherm and kinetic study conducted, it was found that Freundlich isotherm model and a pseudo second-order kinetic model was best fitted for adsorption of MB dye. The MLNR/AAc-BiFeO3 composite maintains its removal efficiency after 5 cycles without the necessity of post-treatment separation. Therefore, it is crucial to note that the resultant low-cost MLNR/AAc-BiFeO3 hydrogel composite in this study offers excellent potential for water and wastewater treatment applications with improved recyclability and recovery.
  16. Abdullah MR, Faizli AA, Noordin SS, Lee CJ, Ahmad NH
    Transfus Apher Sci, 2021 Jun;60(3):103076.
    PMID: 33574008 DOI: 10.1016/j.transci.2021.103076
    H-deficient phenotype individuals with absent or weak anti-H activity may remain undetected on standard routine blood grouping. We report a case of a 59-year-old-man presented with symptomatic anaemia secondary to upper gastrointestinal bleed with haemoglobin level of 68 g/L who required two units of packed red blood cells. He was previously grouped as O Rh D positive and had a history of uneventful multiple blood transfusions. His latest pre-transfusion investigations showed ABO discrepancy between forward and reverse blood grouping, pan-agglutination in both antibody screening and identification with negative direct Coombs test and autocontrol. Further testing including anti-H lectin test and saliva secretor study confirmed that the patient blood group was para-Bombay B RhD positive. This case highlights that the para-Bombay phenotype can be mistakenly labelled as "O" if further investigations are not performed.
  17. Ng EP, Ahmad NH, Khoerunnisa F, Mintova S, Ling TC, Daou TJ
    Molecules, 2021 Apr 13;26(8).
    PMID: 33924655 DOI: 10.3390/molecules26082238
    Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates.
  18. Othman NE, Zaki SA, Rijal HB, Ahmad NH, Razak AA
    Int J Biometeorol, 2021 Apr;65(4):453-477.
    PMID: 33416948 DOI: 10.1007/s00484-020-02035-3
    Difficulties in controlling the effects of outdoor thermal environment on the human body are attracting considerable research attention. This study investigated the outdoor thermal comfort of urban pedestrians by assessing their perceptions of the tropical, micrometeorological, and physical conditions via a questionnaire survey. Evaluation of the outdoor thermal comfort involved pedestrians performing various physical activities (sitting, walking, and standing) in outdoor and semi-outdoor spaces where the data collection of air temperature, globe temperature, relative humidity, wind speed, solar radiation, metabolic activity, and clothing insulation data was done simultaneously. A total of 1011 participants were interviewed, and the micrometeorological data were recorded under outdoor and semi-outdoor conditions at two Malaysian university campuses. The neutral temperatures obtained which were 28.1 °C and 30.8 °C were within the biothermal acceptable ranges of 24-34 °C and 26-33 °C of the PET thermal sensation ranges for the outdoor and semi-outdoor conditions, respectively. Additionally, the participants' thermal sensation and preference votes were highly correlated with the PET and strongly related to air and mean radiant temperatures. The findings demonstrated the influence of individuals' thermal adaptation on the outdoor thermal comfort levels. This knowledge could be useful in the planning and designing of outdoor environments in hot and humid regions to create better thermal environments.
  19. Abdul Rahim R, Jayusman PA, Muhammad N, Mohamed N, Lim V, Ahmad NH, et al.
    PMID: 33805420 DOI: 10.3390/ijerph18073532
    Oxidative stress and inflammation are two common risk factors of various life-threatening disease pathogenesis. In recent years, medicinal plants that possess antioxidant and anti-inflammatory activities were extensively studied for their potential role in treating and preventing diseases. Spilanthes acmella (S. acmella), which has been traditionally used to treat toothache in Malaysia, contains various active metabolites responsible for its anti-inflammatory, antiseptic, and anesthetic bioactivities. These bioactivities were attributed to bioactive compounds, such as phenolic, flavonoids, and alkamides. The review focused on the summarization of in vitro and in vivo experimental reports on the antioxidant and anti-inflammatory actions of S. acmella, as well as how they contributed to potential health benefits in lowering the risk of diseases that were related to oxidative stress. The molecular mechanism of S. acmella in reducing oxidative stress and inflammatory targets, such as inducible nitric oxide synthase (iNOS), transcription factors of the nuclear factor-κB family (NF-κB), cyclooxygenase-2 (COX-2), and mitogen-activated protein kinase (MAPK) signaling pathways were discussed. Besides, the antioxidant potential of S. acmella was measured by total phenolic content (TPC), total flavonid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide anion radical scavenging (SOD) and thiobarbituric acid reactive substance (TBARS) assays. This review revealed that S. acmella might have a potential role as a reservoir of bioactive agents contributing to the observed antioxidant, anti-inflammatory, and health beneficial effects.
  20. Abdul Rahim R, Jayusman PA, Lim V, Ahmad NH, Abdul Hamid ZA, Mohamed S, et al.
    Front Pharmacol, 2021;12:796509.
    PMID: 35111063 DOI: 10.3389/fphar.2021.796509
    Blainvillea acmella (L.) Philipson [Asteraceae] (B. acmella) is an important medicinal plant native to Brazil, and it is widely known as a toothache plant. A plethora of studies have demonstrated the antioxidant activities of B. acmella and few studies on the stimulatory effects on alkaline phosphatase (ALP) secretion from bone cells; however, there is no study on its antioxidant and anabolic activity on bone cells. The study aimed to evaluate the phytochemical contents of aqueous and ethanol extracts of B. acmella using gas chromatography mass spectrometry (GCMS) and liquid chromatography time of flight mass spectrometry (LCTOFMS) along with the total phenolic (TPC) and flavonoid (TFC) contents using Folin-Ciocalteu and aluminum colorimetric methods. The extracts of B. acmella leaves were used to scavenge synthetic-free radicals such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The bone anabolic effects of B. acmella extracts on MC3T3-E1 cells were measured with 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoium bromide (MTT) at 1, 3, 5, and 7 days, Sirius-red and ALP at 7 and 14 days, and Alizarin Red S at 14 and 21 days. Comparatively, ethanol extract of B. acmella (BaE) contributed higher antioxidant activities (IC50 of 476.71 µg/ml and 56.01 ± 6.46 mg L-ascorbic acid/g against DPPH and FRAP, respectively). Anabolic activities in bone proliferation, differentiation, and mineralization were also higher in B. acmella of ethanol (BaE) than aqueous (BaA) extracts. Positive correlations were observed between phenolic content (TPC and TFC) to antioxidant (ABTS and FRAP) and anabolic activities. Conversely, negative correlations were present between phenolic content to antioxidant (DPPH) activity. These potential antioxidant and bone anabolic activities in BaE might be due to the phytochemicals confirmed through GCMS and LCTOFMS, revealed that terpenoids of α-cubebene, cryophyllene, cryophyllene oxide, phytol and flavonoids of pinostrobin and apigenin were the compounds contributing to both antioxidant and anabolic effects in BaE. Thus, B. acmella may be a valuable antioxidant and anti-osteoporosis agent. Further study is needed to isolate, characterize and elucidate the underlying mechanisms responsible for the antioxidant and bone anabolic effects.
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