The development of microbial-based products requires certain criteria for them to be successfully commercialized. The product must meet the following desirable criteria: effectiveness, contamination free, stability, c...The development of microbial-based products requires certain criteria for them to be successfully commercialized. The product must meet the following desirable criteria: effectiveness, contamination free, stability, cost-effectiveness, and a prolonged shelf life. Controlling the drying process is crucial for ensuring the stability and durability of the product. The traditional approach, which involved mechanical and natural drying, led to decreased productivity and quality. The objective of this research endeavour was to achieve a dry process enhancement while preserving the microbial quality of Trichoderma asperellum (M103). The temperature and relative humidity during the drying period were monitored under two conditions: with and without a dehumidifier. The results demonstrate that the dehumidifier increases drying period efficiency by up to 63%.展开更多
The purpose of this study is to determine the optimum condition for the tenderization of beef by bromelain using Response Surface Methodology (RSM). Initially, bromelain powder was produced from pineapple crown of var...The purpose of this study is to determine the optimum condition for the tenderization of beef by bromelain using Response Surface Methodology (RSM). Initially, bromelain powder was produced from pineapple crown of variety N36. Production of the bromelain powder involves several process steps such as extraction, purification, desalting and freeze drying. The cube size beef of round part was treated with bromelain at different pHs of beef, immersion temperatures, bromelain solution concentrations, and immersion times according to the experimental design which was recommended by RSM of MINITAB software version 15. Beef tenderness was then measured by Texture Analyser. The MINITAB software Version 15 was used to optimise the tenderisation of beef by bromelain. The determination coefficient R2 was 99.97% meaning that the experimental data were acceptable. It was found that beef could be optimize tenderised 89.907% at the optimum condition at pH of beef of 5.4, immersion temperature of60℃, bromelain solution concentration of 0.1682% and immersion time of 10 minutes. The verification value of beef ten-derisation at the feasible optimum condition which was determined by experiment was 89.571%. Since the difference between the veri- fication and predicted values was less than 5%, therefore, the optimum condition for the tenderisation of beef predicted by MINITAB software Version 15 could be accepted.展开更多
The unsteady mixed convection flow of electrical conducting nanofluid and heat transfer due to a permeable linear stretching sheet with the combined effects of an electric field, magnetic field, thermal radiation, vis...The unsteady mixed convection flow of electrical conducting nanofluid and heat transfer due to a permeable linear stretching sheet with the combined effects of an electric field, magnetic field, thermal radiation, viscous dissipation, and chemical reaction have been investigated. A similarity transformation is used to transform the constitutive equations into a system of nonlinear ordinary differential equations.The resultant system of equations is then solved numerically using implicit finite difference method.The velocity, temperature, concentration, entropy generation, and Bejan number are obtained with the dependence of different emerging parameters examined. It is noticed that the velocity is more sensible with high values of electric field and diminished with a magnetic field. The radiative heat transfer and viscous dissipation enhance the heat conduction in the system. Moreover, the impact of mixed convection parameter and Buoyancy ratio parameter on Bejan number profile has reverse effects. A chemical reaction reduced the nanoparticle concentration for higher values.展开更多
Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical record...Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular Malaysia.Inclusion criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same admission.Viable isolates were re-identified for GBS and serotyped.Results:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue disease.The most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and cellulitis.The overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic individuals.The study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.展开更多
Framework materials such as zeolites and mesoporous silicas are commonly used for many applications,especially catalysis and separation.Here zeolite-mesoporous silica composite catalysts(employing zeolite Y,ZSM-5,KIT-...Framework materials such as zeolites and mesoporous silicas are commonly used for many applications,especially catalysis and separation.Here zeolite-mesoporous silica composite catalysts(employing zeolite Y,ZSM-5,KIT-6,SBA-15 and MCM-41 mesoporous silica)were prepared(with different weight percent of zeolite Y and ZSM-5)and assessed for catalytic cracking(using n-heptane,as the model compound at 550°C)with the aim to improve the selectivity/yield of light olefins of ethylene and propylene from n-heptane.Physicochemical properties of the parent zeolites and the prepared composites were characterized comprehensively using several techniques including X-ray diffraction,nitrogen physisorption,scanning electron microscopy,fourier transform infrared spectroscopy,pulsed-field gradient nuclear magnetic resonance and thermogravimetric analysis.Catalytic cracking results showed that the ZY/ZSM-5/KIT-6 composite(20:20:60 wt%)achieved a high n-heptane conversion of 85%with approximately 6%selectivity to ethylene/propylene.In contrast,the ZY/ZSM-5/SBA-15 composite achieved a higher conversion of 95%and an ethylene/propylene ratio of 8%,indicating a more efficient process in terms of both conversion and selectivity.Magnetic resonance relaxation analysis of the ZY/ZSM-5/KIT-6(20:20:60)catalyst confirmed a micro-mesoporous environment that influences n-heptane diffusion and mass transfer.As zeolite Y and ZSM-5 have micropores,n-heptane can move and undergo hydrogen transfer reactions,whereas KIT-6 has mesopores that facilitate n-heptane’s accessibility to the active sites of zeolite Y and ZSM-5.展开更多
MicroRNAs are small non-coding RNAs that play crucial roles in the regulation of gene expression and protein synthesis during brain development. MiR-3099 is highly expressed throughout embryogenesis, especially in the...MicroRNAs are small non-coding RNAs that play crucial roles in the regulation of gene expression and protein synthesis during brain development. MiR-3099 is highly expressed throughout embryogenesis, especially in the developing central nervous system. Moreover, miR-3099 is also expressed at a higher level in differentiating neurons in vitro, suggesting that it is a potential regulator during neuronal cell development. This study aimed to predict the target genes of miR-3099 via in-silico analysis using four independent prediction algorithms（miRDB,miRanda, Target Scan, and DIANA-micro-T-CDS） with emphasis on target genes related to brain development and function. Based on the analysis, a total of 3,174 miR-3099 target genes were predicted. Those predicted by at least three algorithms（324 genes） were subjected to DAVID bioinformatics analysis to understand their overallfunctional themes and representation. The analysis revealed that nearly 70% of the target genes were expressed in the nervous system and a significant proportion were associated with transcriptional regulation and protein ubiquitination mechanisms. Comparison of in situ hybridization（ISH） expression patterns of miR-3099 in both published and in-house-generated ISH sections with the ISH sections of target genes from the Allen Brain Atlas identified 7 target genes（Dnmt3a, Gabpa, Gfap, Itga4,Lxn, Smad7, and Tbx18） having expression patterns complementary to miR-3099 in the developing and adult mouse brain samples. Of these, we validated Gfap as a direct downstream target of miR-3099 using the luciferase reporter gene system. In conclusion, we report the successful prediction and validation of Gfap as an miR-3099 target gene using a combination of bioinformatics resources with enrichment of annotations based on functional ontologies and a spatio-temporal expression dataset.展开更多
This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identif...This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identify the chemical compositions of the A. rnalaccensis leave-oil. By assessing both first-order kinetic model and the model of simultaneous washing and diffusion, the result indicated that the model of simultaneous washing and diffusion better describes the hydro-distillation mechanism of the essential oil from A. rnalaccensis leaves. The optimum time, solid to liquid ratio, and the heating power for extracting the highest amount of essential oil were found to be around 3 h, 1：10 （g. ml-1）, and 300 W respectively. Yellow essential oil with a strong smell and a yield of 0.05 v/w was extracted by hydro-distillation Clevenger apparatus. Chemical compounds of the essential oil were analyzed using gas chromatography-mass spectroscopy （GC/MS）, which resulted in identification of 42 compounds that constitute 93% of essential oil. Among the identified components, Pentadecanal （32.082%）, 9-Octadecenal, （Z） （15.894%）, and Tetradecanal （6.927%） were the major compounds. Considering the fact that all the identified major components possess pesticidal properties, A. malaccensis leaves can be regarded as a promising natural source for producing pesticides.展开更多
Ceramic parts usually experience dynamic load in armor applications. Therefore, studying the dynamic behaviors of ceramics is important. Limited data are available on the dynamic behaviors of ceramics; thus, it is hel...Ceramic parts usually experience dynamic load in armor applications. Therefore, studying the dynamic behaviors of ceramics is important. Limited data are available on the dynamic behaviors of ceramics; thus, it is helpful to predict the dynamic strength of ceramics on the basis of their mechanical properties. In this paper, the addition of SrCO3 into zirconia-toughened alumina（ZTA） was demonstrated to improve the fracture toughness of ZTA due to the formation of the SrAl12O19（SA6） phase. The porosity of ZTA was found to be increased by the addition of SrCO3. These newly formed pores served as the nucleation sites of cracks under dynamic load; these cracks eventually coalesced to form damaged zones in the samples. Although the KIC values of the samples were improved, the dynamic strength was not enhanced because of the increase in porosity; in fact, the dynamic strength of ZTA ceramics decreased with the addition of SrCO3.展开更多
Summary:Unilateral rhinorrhoea in the paediatric age group could be an alarming sign that warrants a clinician attention.These patients are routinely brought to see general practitioner as parents may not be aware of ...Summary:Unilateral rhinorrhoea in the paediatric age group could be an alarming sign that warrants a clinician attention.These patients are routinely brought to see general practitioner as parents may not be aware of the urgency to intervene surgically.Herein we describe a case of a toddler who presented initially to a general practitioner with unilateral nasal discharge.He was subsequently referred to the otorhinolaryngology department for unresolved rhinitis.The child was examined,and the diagnosis of an embedded foreign body was made.X-ray of the paranasal sinus unveiled an embedded button battery.An emergency endoscopic retrieval of the button battery was performed under general anaesthesia.Unfortunately,the case was complicated with a huge septal perforation.展开更多
River bank erosion is one of the major and unpredictable hazards worldwide including in Malaysia.Soil detachment at river banks is due to two processes:1)hydraulic erosion imposed by channel flow and 2)sub aerial eros...River bank erosion is one of the major and unpredictable hazards worldwide including in Malaysia.Soil detachment at river banks is due to two processes:1)hydraulic erosion imposed by channel flow and 2)sub aerial erosion due to the weakening and weathering of bank materials.This paper is focused on the second aspect of the erosion process which mainly depends on the combination of rainfall intensity and the ability of the soil to withstand the raindrop effects.The relative combination of sand,silt and clay in a soil is argued to have an impact on erosion resistance.In cohesive soil composition,sand forms the largest size ranging from 0.05 to 2 mm whereas silt is adequately moderate(ranging from 0.002 to 0.05 mm)and clay is the smallest of all three(less than 0.002 mm).With the knowledge that soil composition does indeed have an effect on erosion resistance,this paper will attempt to relate risk assessment index of river bank erosion specifically to soil composition.Thus,the objectives of this document are as follows;1)to produce risk assessment index for river bank erosion and 2)to carry out a case study for selected rivers in Malaysia pertaining to river bank assessment.The index is produced by inferring the previously developed scale on soil erodibility.Past researchers created the“ROM”scale(named after the researchers,Rolan and Mazidah)to assess degree of soil erodibility into five classes namely“critical”,“very high”,“high”,“medium”and“low”.Instead of using semi empirical formula from the“ROM”scale,a percentage of soil composition was inferred to produce risk assessment index.It was found that as the percentage of clay decreased,susceptibility index became higher and approached a critical level.Application of the newly developed index is verified by conducting a case study at the Langat River,Kajang,Malaysia.The soil composition was classified and form fitted into the index.It was found that the middle reach of the Langat river is susceptible to severe erosion due to low percentage展开更多
Electroceramic calcium copper titanates(CaCu3Ti4O12,CCTO),with high dielectric permittivities（e） of approximately 105 and 104,respectively,for single crystal and bulk materials,are produced for a number of wellestab...Electroceramic calcium copper titanates(CaCu3Ti4O12,CCTO),with high dielectric permittivities（e） of approximately 105 and 104,respectively,for single crystal and bulk materials,are produced for a number of wellestablished and emerging applications such as resonator,capacitor,and sensor.These applications take advantage of the unique properties achieved through the structure and properties of CCTO.This review comprehensively focuses on the primary processing routes,effect of impurity,dielectric permittivity,and deposition technique used for the processing of electroceramics along with their chemical composition and micro and nanostructures.Emphasis is given to versatile and basic approaches that allow one to control the microstructural features that ultimately determine the properties of the CCTO ceramic.Despite the intensive research in this area,none of the studies available in the literature provides all the possible relevant information about CCTO fabrication,structure,the factors influencing its dielectric properties,CCTO immobilization,and sensing applications.展开更多
The influence of La_(2)O_(3) inclusion(0-3 wt%) on the micro structure,phase formation and mechanical properties of zirconia toughed alumina(ZTA) added with 5.0 wt% CeO_(2) was investigated.ZTA CeO_(2) composites were...The influence of La_(2)O_(3) inclusion(0-3 wt%) on the micro structure,phase formation and mechanical properties of zirconia toughed alumina(ZTA) added with 5.0 wt% CeO_(2) was investigated.ZTA CeO_(2) composites were sintered at 1600℃ for 4 h.The microstructure,phase formation,density,fracture toughness and hardness properties were characterised through FESEM,Microscopy Image Analysis Software and XRD diffractometer,Archimedes principle and Vickers indentation technique,respectively.The XRD,image processing and FESEM reveal the existence of LaAl_(11)O_(18).The addition of La_(2)O_(3) incites the sintering,microstructure refinement,densification of ZTA-CeO_(2) matrix and phase transformation.Hence,the hardness of ZTA-CeO_(2) ceramics is increased rapidly based on refinement of Al_(2)O_(3) grains,densification of ZTA-CeO_(2) composites and porosity reduction.It is observed that the fracture toughness is enhanced through in situ formation of elongated LaAl_(11)O_(18) grains.The addition of 0.7 wt% La_(2)O_(3) culminated in the achievement of the optimum findings for density(4.41 g/cm^(3)),porosity(0.46%),hardness(1792 HV) and fracture toughness(8.8 MPa·m^(1/2)).Nevertheless,excess La_(2)O_(3) is proven to be detrimental as it displays poor mechanical properties due to the poor compactness of numerous LaAl_(11)O_(18) grains,coarsening of Al_(2)O_(3) grains and decline in density.展开更多
and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study i...and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study is conducted in the selected hospitals with similar approaches.GBS isolates are subjected to phenotyping,serotyping by multiplex PCR,antimicrobial susceptibility testing and PCR-detection of GBS virulence and pilus genes.Seven housekeeping genes are amplified and sequenced for multi-locus sequence typing.Discussion:Findings from the study may contribute to the management of clinical practice to diagnose and prevent GBS related diseases in a timely manner.Prudent use of antibiotics is encouraged by monitoring antimicrobial resistance.展开更多
The policy of encouraging agriculture and development for mass tourism has led to environmental problems in Cameron Highlands,Malaysia.Rampant development and land clearing have significantly altered the land cover of...The policy of encouraging agriculture and development for mass tourism has led to environmental problems in Cameron Highlands,Malaysia.Rampant development and land clearing have significantly altered the land cover of Cameron Highlands for the past 30 years.Sensitive highlands areas are prone to landslides and soil erosion which then contributed to the main water pollution issues in the network of river system,sedimentation and siltation.The continuous trend of river water quality deterioration in Cameron Highlands has raised the issues for discussion in this review article.The purpose of this review is to briefly summarize the land use change,agriculture practices,agro-tourism,and agriculture policy and management toward water quality of the river system network in Cameron Highlands specifically in the downtown where most of the development and agriculture activities are concentrated.A rigorous review has been done on the existing literature to determine the relationship between land use change and agriculture practices toward river water quality in Cameron Highlands from 2001 to 2017.The total number of reviewed papers was 68.The outcomes established from previous researchers have highlighted factors such as soil erosion,landslides,agriculture activities,urbanization,and unplanned development associated with land use change have significantly influenced the river water quality in the highland areas.Continuous land use changes without proper development plan and law enforcement may critically threaten the sustainability of river network in the highlands area.展开更多
Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic c...Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic condition. Herein, a novel non-covalent surface modification approach towards graphene oxide was conducted via a UV-induced photo-polymerization technique that involves two major routes; a UV-sensitive initiator embedded via pi-pi interactions on the graphene planar rings, and the polymerization of hydrophobic polymeric chains along the surface. The functionalized graphene oxide successfully achieved the desired hydrophobicity as it displayed the characteristic of being readily dissolved in organic solvent. Upon its addition into a polymeric solution and subjected to an electrospinning process,non-woven random nanofibers embedded with graphene oxide sheets were obtained. The prepared polymeric nanofibers were subjected to two-step thermal treatments that eventually converted the polymeric chains into a carbon-rich conductive structure. A unique morphology was observed upon the addition of the functionalized graphene oxide, whereby the sheets were embedded and intercalated within the carbon nanofibers and formed a continuous structure. This reinforcement effectively enhanced the electrochemical performance of the carbon nanofibers by recording a specific capacitance of up to 140.10 F/g at the current density of 1 A/g, which was approximately three folds more than that of pristine nanofibers.It also retained the capacitance up to 96.2% after 1000 vigorous charge/discharge cycles. This functionalization technique opens up a new pathway in tuning the solubility nature of graphene oxide towards the synthesis of a graphene oxide-reinforced polymeric structure.展开更多
Use of pesticides,herbicides and fertilizers is among the techniques to control insect pests and fungal pathogens.However,the technique is the major contributor to severe environmental implications in terms of air,wat...Use of pesticides,herbicides and fertilizers is among the techniques to control insect pests and fungal pathogens.However,the technique is the major contributor to severe environmental implications in terms of air,water and soil pollution.Besides,variable inconsistency becomes an important issue in the implementation of inclined bed dryers,leading to significant rice grain loss.Cold plasma technology has been widely proposed as a potential alternative for rice grain postharvest treatment management due to the presence of generated ionised gas that eventually produces reactive oxygen species or reactive nitrogen species.These species are used to decontaminate foodborne pathogens,mycotoxins and bacterial diseases.This review explores the current literature regarding cold plasma treatment technology,focusing on its efficiency as the microbial decontamination medium and insect pest mortality medium,and on the enhancement functional,nutritional and cooking properties,especially in rice grains.Previous studies have successfully demonstrated the ability of cold plasma treatment to significantly reduce the microbial count of foodborne pathogens,detoxify mycotoxins,and control seedborne rice seedling bacterial diseases.Previous studies have also proved that the implementation of cold plasma technology in postharvest management should be seriously considered for improving rice grain quantity and quality in Malaysia.展开更多
Bio based nitrogen doped carbon dots(N-CDs)were obtained from empty fruit bunch carboxymethylcellulose and ethylenediamine(EDA)through one-pot hydrothermal carbonization route.The optimum as-formed NCDs were thoroughl...Bio based nitrogen doped carbon dots(N-CDs)were obtained from empty fruit bunch carboxymethylcellulose and ethylenediamine(EDA)through one-pot hydrothermal carbonization route.The optimum as-formed NCDs were thoroughly characterized via Transmission electron microscopy(TEM),high-resolution TEM(HRTEM),Fourier transform infrared(FTIR),X-ray photoelectron spectra(XPS),UV–vis spectra(UV–Vis)and Fluorescence spectra(PL).Response surface methodology was statistically used to assess three independent variables that have major influence on the fluorescence quantum yield(QY),including temperature(230–270℃),time(2–6 h)and EDA mass(10%–23.3%).Based on analysis of variance(ANOVA)results,synthesis temperature was found to be the most influential factor on the QY,followed by time and EDA mass.Higher temperature,long synthesis time and high amount of EDA were satisfactorily enough for efficient carbonization conversion rate and obtaining highest QY of N-CDs.The obtained quadratic model(R^2=0.9991)shows a good correlation between the experimental data and predicted values.The optimum synthetic parameters are of 270℃temperature,6 h reaction time and 23.3%of EDA mass.The optimized as-made N-CDs exhibited blue photoluminescence with both excitation dependent/independent phenomena and high nitrogen content.The maximum emission intensity was 426 nm at a maximum excitation wavelength of 320 nm,with a QY of up to 22.9%.XPS and FTIR data confirmed the existence of polar containing groups,such as carbonyl,carboxyl,hydroxyl and amino groups over the surface of N-CDs whereas nitrogen species in the form of(pyridinic and graphitic-N)were introduced in the aromatic carbon domains,which imparts the hydrophilic and photostability of N-CDs.Taking into account the low-cost and sustainable production of N-CDs,this method considered a feasible route for converting low quality waste into value-added nanomaterials and utilizing for different functionalization processes and analytical applications.展开更多
Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.f...Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.farinae)and Dermalophagoides pteronyssinus(D.pteronyssinus).Methods:Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations(50.00%,25.00%,12.50%,6.25%and 3.13%)and exposure times(24hrs,48hrs,72hrs and 96 hrs).All treatments were replicated 7 times,and the experiment repeated once.The topical and contact activities of the two herbs were investigated.Results:Mortalities from lemongrass extract were higher than neem for both topical and contact activities.At 50%concentration,both 24 hrs topical and contact exposures to lemongrass resulted in more than 91%mortalities for both species of inites.At the same concentration and exposure time,neem resulted in topical mortalities of 40.3%and 15.7%against D.pteronyssinus and D.farinae respectively;contact mortalities were 8.0%and 8.9%against the 2 mites,respectively.There was no difference in topical mortalities of D.pteronyssinus from exposure to concentrations oflemongrass and neem up to 12.50%;lemongrass was more effective than neem at the higher concentrations.Conclusions:Generally,topical mortalities of D.farinae due to lemongrass are higher than that due to neem.Contact mortalities of lemongrass are always higher that neem against both species of mites.展开更多
Objective:To investigate the possible phytochemical constituents of Curcuma aeruginosa Roxb.(C. aeruginosa) rhizome using two different techniques of direct solvent extraction. Methods: Two different techniques of dir...Objective:To investigate the possible phytochemical constituents of Curcuma aeruginosa Roxb.(C. aeruginosa) rhizome using two different techniques of direct solvent extraction. Methods: Two different techniques of direct solvent extractions, i.e. methyl tert-butyl ether(MTBE) extraction and two-phase methanol/chloroform(M/C) system, were used in this study. The analysis of the phytochemical constituents in MTBE and M/C extracts was performed using gas chromatography-mass spectrometry/mass spectrometry. The mass spectra of the compounds was matched with the NIST 08 mass spectral library. Results: The present study revealed that the extraction using two-phase M/C have resulted in higher metabolite coverage compared to the extraction with MTBE. Direct solvent extraction using MTBE revealed the presence of 27 compounds; whereas, M/C allowed the extraction of 18 and 36 compounds in polar(methanol) and nonpolar(chloroform) fractions respectively. The major compounds detected in the MTBE extract that based on the peak area percentage were methenolone(16.64%), cycloisolongifolene, 8,9-dehydro-9-formyl-(15.93%), labd-13-en-15-oic acid,8,12-epoxy-12-hydroxy-γ-lactone(10.77%), propiolic acid, 3-(1-hydroxy)-2 isopropyl-1,5-methylcyclohexyl)(7.84%), 4-oxo-β-isodamascol(5.17%), velleral(3.11%) and Z-α-farnesene(2.00%). The most prevailing major compounds identified in the polar fraction of the M/C extraction were α-D glucopyranoside, 1,3,4,6 tetrakis-O-(TMS)(trimethylsilyl)-β-D-fructofuranosyl 2,3,4,6-tetrakis-O-(TMS)-(38.08%), d-glucose, 2,3,4,5,6-pentakis-O-(TMS)-, O-methyloxime(14.61%), D-fructose, 1,3,4,5,6-pentakis-O-(TMS)-, O-methyloxime(5.28%), isocitric acid(TMS)(3.06%), oxalic acid, bis(TMS) ester(2.96%), hexadecanoic acid, TMS ester(2.16%), citric acid, ethyl ester, tri-TMS(1.91%) and butanedioic acid, [(TMS) oxy]-, bis(TMS) ester(1.14%); whereas in the nonpolar extract, among the major compounds detected were cycloisolongifolene, 8, 9-dehydro-9-formyl(15.70%), propiolic acid, 3-(1-hydroxy-2-isopropyl-5-methylcy展开更多
Background:Erythrina suberosa(E.suberosa)Roxb.also known as corky coral tree is used as a folklore medicine to treat ulcers and piles.This study explored the phytochemical profiles of methanol and dichloromethane(DCM)...Background:Erythrina suberosa(E.suberosa)Roxb.also known as corky coral tree is used as a folklore medicine to treat ulcers and piles.This study explored the phytochemical profiles of methanol and dichloromethane(DCM)extracts from the aerial,root,and flower parts of E.suberosa.Method:Total bioactive contents,high-performance liquid chromatography array(HPLC-PDA)polyphenolic quantification,and ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)analysis were used to evaluate the phytochemical profile.Biological potential was evaluated by determining their antioxidant(DPPH,ABTS,FRAP,CUPRAC,Phosphomolybdenum,and metal chelating)and enzyme inhibitory(cholinesterase,amylase,glucosidase,and tyrosinase)effects.Results:The phenolic(46.26 mg GAE/g extract)and flavonoid(32.46 mg QE/g extract)contents were found to be highest in the methanolic extract of roots(EsR-M).HPLC-PDA analysis determined the presence of numerous bioactive compounds,including catechin,syringic acid,p-hydroxy benzoic acid,gallic acid,vanillic acid,epicatechin,rutin,chlorogenic acid,carvacrol,sinapinic acid,and naringenin in considerable amounts.A total of 143 phytochemicals,belonging to phenolic,flavonoid,coumarin,terpenoid,chalcone,saponin,and glycoside classes,were tentatively identified by UHPLC-MS analysis.Aerial methanolic extract(EsA-M)exhibited highest radical scavenging(DPPH 86.81 mgTE/g extract,ABTS 245.17 mgTE/g extract)as well as reducing potential(FRAP 177.12 mgTE/g extract,CUPRAC 177.12 mgTE/g extract).Likewise,it was also noted to be most active for BChE(5.70 mg GALAE/g extract)and tyrosinase inhibition(148.35 mg KAE/g extract).While,roots-DCM extract(EsR-D)presented considerable inhibition for AChE(4.69 mg GALAE/g extract)and amylase(0.81 mmol ACAE/g extract)enzymes.Coreopsin,davallioside A,and isovitexin were docked to tyrosinase to depict possible interaction.Conclusion:This study has established baseline data on the biological and phytochemical profile of E.suberosa which was found to possess antioxidant and enzym展开更多
文摘The development of microbial-based products requires certain criteria for them to be successfully commercialized. The product must meet the following desirable criteria: effectiveness, contamination free, stability, cost-effectiveness, and a prolonged shelf life. Controlling the drying process is crucial for ensuring the stability and durability of the product. The traditional approach, which involved mechanical and natural drying, led to decreased productivity and quality. The objective of this research endeavour was to achieve a dry process enhancement while preserving the microbial quality of Trichoderma asperellum (M103). The temperature and relative humidity during the drying period were monitored under two conditions: with and without a dehumidifier. The results demonstrate that the dehumidifier increases drying period efficiency by up to 63%.
文摘The purpose of this study is to determine the optimum condition for the tenderization of beef by bromelain using Response Surface Methodology (RSM). Initially, bromelain powder was produced from pineapple crown of variety N36. Production of the bromelain powder involves several process steps such as extraction, purification, desalting and freeze drying. The cube size beef of round part was treated with bromelain at different pHs of beef, immersion temperatures, bromelain solution concentrations, and immersion times according to the experimental design which was recommended by RSM of MINITAB software version 15. Beef tenderness was then measured by Texture Analyser. The MINITAB software Version 15 was used to optimise the tenderisation of beef by bromelain. The determination coefficient R2 was 99.97% meaning that the experimental data were acceptable. It was found that beef could be optimize tenderised 89.907% at the optimum condition at pH of beef of 5.4, immersion temperature of60℃, bromelain solution concentration of 0.1682% and immersion time of 10 minutes. The verification value of beef ten-derisation at the feasible optimum condition which was determined by experiment was 89.571%. Since the difference between the veri- fication and predicted values was less than 5%, therefore, the optimum condition for the tenderisation of beef predicted by MINITAB software Version 15 could be accepted.
基金supported by the research grant under the Ministry of Higher Education (MOHE)the Fundamental Research Grant Scheme (FRGS) project vote number R.J 130000.7809.4F354
文摘The unsteady mixed convection flow of electrical conducting nanofluid and heat transfer due to a permeable linear stretching sheet with the combined effects of an electric field, magnetic field, thermal radiation, viscous dissipation, and chemical reaction have been investigated. A similarity transformation is used to transform the constitutive equations into a system of nonlinear ordinary differential equations.The resultant system of equations is then solved numerically using implicit finite difference method.The velocity, temperature, concentration, entropy generation, and Bejan number are obtained with the dependence of different emerging parameters examined. It is noticed that the velocity is more sensible with high values of electric field and diminished with a magnetic field. The radiative heat transfer and viscous dissipation enhance the heat conduction in the system. Moreover, the impact of mixed convection parameter and Buoyancy ratio parameter on Bejan number profile has reverse effects. A chemical reaction reduced the nanoparticle concentration for higher values.
基金the Research Grants from Universiti Putra Malaysia(UPM/800-3/3/1/GPB/2020/9683800)Ministry of Higher Education under the Fundamental Research Grant Scheme(FRGS/1/2023/WAB04/UPM/01/4).
文摘Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular Malaysia.Inclusion criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same admission.Viable isolates were re-identified for GBS and serotyped.Results:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue disease.The most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and cellulitis.The overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic individuals.The study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.
基金China Scholarship Council for his PhD secondment at The University of Manchester(CSC file No.201906120207).
文摘Framework materials such as zeolites and mesoporous silicas are commonly used for many applications,especially catalysis and separation.Here zeolite-mesoporous silica composite catalysts(employing zeolite Y,ZSM-5,KIT-6,SBA-15 and MCM-41 mesoporous silica)were prepared(with different weight percent of zeolite Y and ZSM-5)and assessed for catalytic cracking(using n-heptane,as the model compound at 550°C)with the aim to improve the selectivity/yield of light olefins of ethylene and propylene from n-heptane.Physicochemical properties of the parent zeolites and the prepared composites were characterized comprehensively using several techniques including X-ray diffraction,nitrogen physisorption,scanning electron microscopy,fourier transform infrared spectroscopy,pulsed-field gradient nuclear magnetic resonance and thermogravimetric analysis.Catalytic cracking results showed that the ZY/ZSM-5/KIT-6 composite(20:20:60 wt%)achieved a high n-heptane conversion of 85%with approximately 6%selectivity to ethylene/propylene.In contrast,the ZY/ZSM-5/SBA-15 composite achieved a higher conversion of 95%and an ethylene/propylene ratio of 8%,indicating a more efficient process in terms of both conversion and selectivity.Magnetic resonance relaxation analysis of the ZY/ZSM-5/KIT-6(20:20:60)catalyst confirmed a micro-mesoporous environment that influences n-heptane diffusion and mass transfer.As zeolite Y and ZSM-5 have micropores,n-heptane can move and undergo hydrogen transfer reactions,whereas KIT-6 has mesopores that facilitate n-heptane’s accessibility to the active sites of zeolite Y and ZSM-5.
基金supported by the Science Fund(02-01-04-SF2336)the Fundamental Research Grant Scheme,Ministry of Higher Education,Malaysia(FRGS-04-01-15-1663FR)
文摘MicroRNAs are small non-coding RNAs that play crucial roles in the regulation of gene expression and protein synthesis during brain development. MiR-3099 is highly expressed throughout embryogenesis, especially in the developing central nervous system. Moreover, miR-3099 is also expressed at a higher level in differentiating neurons in vitro, suggesting that it is a potential regulator during neuronal cell development. This study aimed to predict the target genes of miR-3099 via in-silico analysis using four independent prediction algorithms（miRDB,miRanda, Target Scan, and DIANA-micro-T-CDS） with emphasis on target genes related to brain development and function. Based on the analysis, a total of 3,174 miR-3099 target genes were predicted. Those predicted by at least three algorithms（324 genes） were subjected to DAVID bioinformatics analysis to understand their overallfunctional themes and representation. The analysis revealed that nearly 70% of the target genes were expressed in the nervous system and a significant proportion were associated with transcriptional regulation and protein ubiquitination mechanisms. Comparison of in situ hybridization（ISH） expression patterns of miR-3099 in both published and in-house-generated ISH sections with the ISH sections of target genes from the Allen Brain Atlas identified 7 target genes（Dnmt3a, Gabpa, Gfap, Itga4,Lxn, Smad7, and Tbx18） having expression patterns complementary to miR-3099 in the developing and adult mouse brain samples. Of these, we validated Gfap as a direct downstream target of miR-3099 using the luciferase reporter gene system. In conclusion, we report the successful prediction and validation of Gfap as an miR-3099 target gene using a combination of bioinformatics resources with enrichment of annotations based on functional ontologies and a spatio-temporal expression dataset.
文摘This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identify the chemical compositions of the A. rnalaccensis leave-oil. By assessing both first-order kinetic model and the model of simultaneous washing and diffusion, the result indicated that the model of simultaneous washing and diffusion better describes the hydro-distillation mechanism of the essential oil from A. rnalaccensis leaves. The optimum time, solid to liquid ratio, and the heating power for extracting the highest amount of essential oil were found to be around 3 h, 1：10 （g. ml-1）, and 300 W respectively. Yellow essential oil with a strong smell and a yield of 0.05 v/w was extracted by hydro-distillation Clevenger apparatus. Chemical compounds of the essential oil were analyzed using gas chromatography-mass spectroscopy （GC/MS）, which resulted in identification of 42 compounds that constitute 93% of essential oil. Among the identified components, Pentadecanal （32.082%）, 9-Octadecenal, （Z） （15.894%）, and Tetradecanal （6.927%） were the major compounds. Considering the fact that all the identified major components possess pesticidal properties, A. malaccensis leaves can be regarded as a promising natural source for producing pesticides.
基金supported by research university grant (RU) of 1001/PBAHAN/811212 from Universiti Sains Malaysia
文摘Ceramic parts usually experience dynamic load in armor applications. Therefore, studying the dynamic behaviors of ceramics is important. Limited data are available on the dynamic behaviors of ceramics; thus, it is helpful to predict the dynamic strength of ceramics on the basis of their mechanical properties. In this paper, the addition of SrCO3 into zirconia-toughened alumina（ZTA） was demonstrated to improve the fracture toughness of ZTA due to the formation of the SrAl12O19（SA6） phase. The porosity of ZTA was found to be increased by the addition of SrCO3. These newly formed pores served as the nucleation sites of cracks under dynamic load; these cracks eventually coalesced to form damaged zones in the samples. Although the KIC values of the samples were improved, the dynamic strength was not enhanced because of the increase in porosity; in fact, the dynamic strength of ZTA ceramics decreased with the addition of SrCO3.
文摘Summary:Unilateral rhinorrhoea in the paediatric age group could be an alarming sign that warrants a clinician attention.These patients are routinely brought to see general practitioner as parents may not be aware of the urgency to intervene surgically.Herein we describe a case of a toddler who presented initially to a general practitioner with unilateral nasal discharge.He was subsequently referred to the otorhinolaryngology department for unresolved rhinitis.The child was examined,and the diagnosis of an embedded foreign body was made.X-ray of the paranasal sinus unveiled an embedded button battery.An emergency endoscopic retrieval of the button battery was performed under general anaesthesia.Unfortunately,the case was complicated with a huge septal perforation.
基金partially funded by Ministry of Higher Education Malaysia(MOHE)through Fundamental Research Grant(FRGS/1/2016/WAB05/IUKL/03/1).
文摘River bank erosion is one of the major and unpredictable hazards worldwide including in Malaysia.Soil detachment at river banks is due to two processes:1)hydraulic erosion imposed by channel flow and 2)sub aerial erosion due to the weakening and weathering of bank materials.This paper is focused on the second aspect of the erosion process which mainly depends on the combination of rainfall intensity and the ability of the soil to withstand the raindrop effects.The relative combination of sand,silt and clay in a soil is argued to have an impact on erosion resistance.In cohesive soil composition,sand forms the largest size ranging from 0.05 to 2 mm whereas silt is adequately moderate(ranging from 0.002 to 0.05 mm)and clay is the smallest of all three(less than 0.002 mm).With the knowledge that soil composition does indeed have an effect on erosion resistance,this paper will attempt to relate risk assessment index of river bank erosion specifically to soil composition.Thus,the objectives of this document are as follows;1)to produce risk assessment index for river bank erosion and 2)to carry out a case study for selected rivers in Malaysia pertaining to river bank assessment.The index is produced by inferring the previously developed scale on soil erodibility.Past researchers created the“ROM”scale(named after the researchers,Rolan and Mazidah)to assess degree of soil erodibility into five classes namely“critical”,“very high”,“high”,“medium”and“low”.Instead of using semi empirical formula from the“ROM”scale,a percentage of soil composition was inferred to produce risk assessment index.It was found that as the percentage of clay decreased,susceptibility index became higher and approached a critical level.Application of the newly developed index is verified by conducting a case study at the Langat River,Kajang,Malaysia.The soil composition was classified and form fitted into the index.It was found that the middle reach of the Langat river is susceptible to severe erosion due to low percentage
基金supported by the Universiti Sains Malaysia(USM) fellowship(APEX 91002/JHEA/ATSG4001)fundamental research grant scheme(FRGS) under grant number of 203/PBAHAN/6071263
文摘Electroceramic calcium copper titanates(CaCu3Ti4O12,CCTO),with high dielectric permittivities（e） of approximately 105 and 104,respectively,for single crystal and bulk materials,are produced for a number of wellestablished and emerging applications such as resonator,capacitor,and sensor.These applications take advantage of the unique properties achieved through the structure and properties of CCTO.This review comprehensively focuses on the primary processing routes,effect of impurity,dielectric permittivity,and deposition technique used for the processing of electroceramics along with their chemical composition and micro and nanostructures.Emphasis is given to versatile and basic approaches that allow one to control the microstructural features that ultimately determine the properties of the CCTO ceramic.Despite the intensive research in this area,none of the studies available in the literature provides all the possible relevant information about CCTO fabrication,structure,the factors influencing its dielectric properties,CCTO immobilization,and sensing applications.
基金This work is financially supported by research university grantUniversiti Sains Malaysia RUI 1001/PBAHAN/811212teaching fellow scheme USM.9/25 Jld.ⅩⅢ。
文摘The influence of La_(2)O_(3) inclusion(0-3 wt%) on the micro structure,phase formation and mechanical properties of zirconia toughed alumina(ZTA) added with 5.0 wt% CeO_(2) was investigated.ZTA CeO_(2) composites were sintered at 1600℃ for 4 h.The microstructure,phase formation,density,fracture toughness and hardness properties were characterised through FESEM,Microscopy Image Analysis Software and XRD diffractometer,Archimedes principle and Vickers indentation technique,respectively.The XRD,image processing and FESEM reveal the existence of LaAl_(11)O_(18).The addition of La_(2)O_(3) incites the sintering,microstructure refinement,densification of ZTA-CeO_(2) matrix and phase transformation.Hence,the hardness of ZTA-CeO_(2) ceramics is increased rapidly based on refinement of Al_(2)O_(3) grains,densification of ZTA-CeO_(2) composites and porosity reduction.It is observed that the fracture toughness is enhanced through in situ formation of elongated LaAl_(11)O_(18) grains.The addition of 0.7 wt% La_(2)O_(3) culminated in the achievement of the optimum findings for density(4.41 g/cm^(3)),porosity(0.46%),hardness(1792 HV) and fracture toughness(8.8 MPa·m^(1/2)).Nevertheless,excess La_(2)O_(3) is proven to be detrimental as it displays poor mechanical properties due to the poor compactness of numerous LaAl_(11)O_(18) grains,coarsening of Al_(2)O_(3) grains and decline in density.
基金funded by the Ministry of Higher Education under Fundamental Research Grant Scheme(FRGS/1/2023/WAB04/UPM/01/4).
文摘and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study is conducted in the selected hospitals with similar approaches.GBS isolates are subjected to phenotyping,serotyping by multiplex PCR,antimicrobial susceptibility testing and PCR-detection of GBS virulence and pilus genes.Seven housekeeping genes are amplified and sequenced for multi-locus sequence typing.Discussion:Findings from the study may contribute to the management of clinical practice to diagnose and prevent GBS related diseases in a timely manner.Prudent use of antibiotics is encouraged by monitoring antimicrobial resistance.
基金Financial support for this study was provided by the National Hydraulic Research Institute of Malaysia(NAHRIM)Sumitomo Foundation Research Grant(Reg.No.168401-41).
文摘The policy of encouraging agriculture and development for mass tourism has led to environmental problems in Cameron Highlands,Malaysia.Rampant development and land clearing have significantly altered the land cover of Cameron Highlands for the past 30 years.Sensitive highlands areas are prone to landslides and soil erosion which then contributed to the main water pollution issues in the network of river system,sedimentation and siltation.The continuous trend of river water quality deterioration in Cameron Highlands has raised the issues for discussion in this review article.The purpose of this review is to briefly summarize the land use change,agriculture practices,agro-tourism,and agriculture policy and management toward water quality of the river system network in Cameron Highlands specifically in the downtown where most of the development and agriculture activities are concentrated.A rigorous review has been done on the existing literature to determine the relationship between land use change and agriculture practices toward river water quality in Cameron Highlands from 2001 to 2017.The total number of reviewed papers was 68.The outcomes established from previous researchers have highlighted factors such as soil erosion,landslides,agriculture activities,urbanization,and unplanned development associated with land use change have significantly influenced the river water quality in the highland areas.Continuous land use changes without proper development plan and law enforcement may critically threaten the sustainability of river network in the highlands area.
文摘Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic condition. Herein, a novel non-covalent surface modification approach towards graphene oxide was conducted via a UV-induced photo-polymerization technique that involves two major routes; a UV-sensitive initiator embedded via pi-pi interactions on the graphene planar rings, and the polymerization of hydrophobic polymeric chains along the surface. The functionalized graphene oxide successfully achieved the desired hydrophobicity as it displayed the characteristic of being readily dissolved in organic solvent. Upon its addition into a polymeric solution and subjected to an electrospinning process,non-woven random nanofibers embedded with graphene oxide sheets were obtained. The prepared polymeric nanofibers were subjected to two-step thermal treatments that eventually converted the polymeric chains into a carbon-rich conductive structure. A unique morphology was observed upon the addition of the functionalized graphene oxide, whereby the sheets were embedded and intercalated within the carbon nanofibers and formed a continuous structure. This reinforcement effectively enhanced the electrochemical performance of the carbon nanofibers by recording a specific capacitance of up to 140.10 F/g at the current density of 1 A/g, which was approximately three folds more than that of pristine nanofibers.It also retained the capacitance up to 96.2% after 1000 vigorous charge/discharge cycles. This functionalization technique opens up a new pathway in tuning the solubility nature of graphene oxide towards the synthesis of a graphene oxide-reinforced polymeric structure.
文摘Use of pesticides,herbicides and fertilizers is among the techniques to control insect pests and fungal pathogens.However,the technique is the major contributor to severe environmental implications in terms of air,water and soil pollution.Besides,variable inconsistency becomes an important issue in the implementation of inclined bed dryers,leading to significant rice grain loss.Cold plasma technology has been widely proposed as a potential alternative for rice grain postharvest treatment management due to the presence of generated ionised gas that eventually produces reactive oxygen species or reactive nitrogen species.These species are used to decontaminate foodborne pathogens,mycotoxins and bacterial diseases.This review explores the current literature regarding cold plasma treatment technology,focusing on its efficiency as the microbial decontamination medium and insect pest mortality medium,and on the enhancement functional,nutritional and cooking properties,especially in rice grains.Previous studies have successfully demonstrated the ability of cold plasma treatment to significantly reduce the microbial count of foodborne pathogens,detoxify mycotoxins,and control seedborne rice seedling bacterial diseases.Previous studies have also proved that the implementation of cold plasma technology in postharvest management should be seriously considered for improving rice grain quantity and quality in Malaysia.
基金Universiti Putra Malaysia for funding this project(GP-IPS/2017/9556800).
文摘Bio based nitrogen doped carbon dots(N-CDs)were obtained from empty fruit bunch carboxymethylcellulose and ethylenediamine(EDA)through one-pot hydrothermal carbonization route.The optimum as-formed NCDs were thoroughly characterized via Transmission electron microscopy(TEM),high-resolution TEM(HRTEM),Fourier transform infrared(FTIR),X-ray photoelectron spectra(XPS),UV–vis spectra(UV–Vis)and Fluorescence spectra(PL).Response surface methodology was statistically used to assess three independent variables that have major influence on the fluorescence quantum yield(QY),including temperature(230–270℃),time(2–6 h)and EDA mass(10%–23.3%).Based on analysis of variance(ANOVA)results,synthesis temperature was found to be the most influential factor on the QY,followed by time and EDA mass.Higher temperature,long synthesis time and high amount of EDA were satisfactorily enough for efficient carbonization conversion rate and obtaining highest QY of N-CDs.The obtained quadratic model(R^2=0.9991)shows a good correlation between the experimental data and predicted values.The optimum synthetic parameters are of 270℃temperature,6 h reaction time and 23.3%of EDA mass.The optimized as-made N-CDs exhibited blue photoluminescence with both excitation dependent/independent phenomena and high nitrogen content.The maximum emission intensity was 426 nm at a maximum excitation wavelength of 320 nm,with a QY of up to 22.9%.XPS and FTIR data confirmed the existence of polar containing groups,such as carbonyl,carboxyl,hydroxyl and amino groups over the surface of N-CDs whereas nitrogen species in the form of(pyridinic and graphitic-N)were introduced in the aromatic carbon domains,which imparts the hydrophilic and photostability of N-CDs.Taking into account the low-cost and sustainable production of N-CDs,this method considered a feasible route for converting low quality waste into value-added nanomaterials and utilizing for different functionalization processes and analytical applications.
文摘Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.farinae)and Dermalophagoides pteronyssinus(D.pteronyssinus).Methods:Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations(50.00%,25.00%,12.50%,6.25%and 3.13%)and exposure times(24hrs,48hrs,72hrs and 96 hrs).All treatments were replicated 7 times,and the experiment repeated once.The topical and contact activities of the two herbs were investigated.Results:Mortalities from lemongrass extract were higher than neem for both topical and contact activities.At 50%concentration,both 24 hrs topical and contact exposures to lemongrass resulted in more than 91%mortalities for both species of inites.At the same concentration and exposure time,neem resulted in topical mortalities of 40.3%and 15.7%against D.pteronyssinus and D.farinae respectively;contact mortalities were 8.0%and 8.9%against the 2 mites,respectively.There was no difference in topical mortalities of D.pteronyssinus from exposure to concentrations oflemongrass and neem up to 12.50%;lemongrass was more effective than neem at the higher concentrations.Conclusions:Generally,topical mortalities of D.farinae due to lemongrass are higher than that due to neem.Contact mortalities of lemongrass are always higher that neem against both species of mites.
基金Supported by Malaysian Agricultural Research and Development Institute(Grant No.P250)Ministry of Science,Technology&Innovation,Malaysia(Grant No.02-03-08-SF 0337)
文摘Objective:To investigate the possible phytochemical constituents of Curcuma aeruginosa Roxb.(C. aeruginosa) rhizome using two different techniques of direct solvent extraction. Methods: Two different techniques of direct solvent extractions, i.e. methyl tert-butyl ether(MTBE) extraction and two-phase methanol/chloroform(M/C) system, were used in this study. The analysis of the phytochemical constituents in MTBE and M/C extracts was performed using gas chromatography-mass spectrometry/mass spectrometry. The mass spectra of the compounds was matched with the NIST 08 mass spectral library. Results: The present study revealed that the extraction using two-phase M/C have resulted in higher metabolite coverage compared to the extraction with MTBE. Direct solvent extraction using MTBE revealed the presence of 27 compounds; whereas, M/C allowed the extraction of 18 and 36 compounds in polar(methanol) and nonpolar(chloroform) fractions respectively. The major compounds detected in the MTBE extract that based on the peak area percentage were methenolone(16.64%), cycloisolongifolene, 8,9-dehydro-9-formyl-(15.93%), labd-13-en-15-oic acid,8,12-epoxy-12-hydroxy-γ-lactone(10.77%), propiolic acid, 3-(1-hydroxy)-2 isopropyl-1,5-methylcyclohexyl)(7.84%), 4-oxo-β-isodamascol(5.17%), velleral(3.11%) and Z-α-farnesene(2.00%). The most prevailing major compounds identified in the polar fraction of the M/C extraction were α-D glucopyranoside, 1,3,4,6 tetrakis-O-(TMS)(trimethylsilyl)-β-D-fructofuranosyl 2,3,4,6-tetrakis-O-(TMS)-(38.08%), d-glucose, 2,3,4,5,6-pentakis-O-(TMS)-, O-methyloxime(14.61%), D-fructose, 1,3,4,5,6-pentakis-O-(TMS)-, O-methyloxime(5.28%), isocitric acid(TMS)(3.06%), oxalic acid, bis(TMS) ester(2.96%), hexadecanoic acid, TMS ester(2.16%), citric acid, ethyl ester, tri-TMS(1.91%) and butanedioic acid, [(TMS) oxy]-, bis(TMS) ester(1.14%); whereas in the nonpolar extract, among the major compounds detected were cycloisolongifolene, 8, 9-dehydro-9-formyl(15.70%), propiolic acid, 3-(1-hydroxy-2-isopropyl-5-methylcy
文摘Background:Erythrina suberosa(E.suberosa)Roxb.also known as corky coral tree is used as a folklore medicine to treat ulcers and piles.This study explored the phytochemical profiles of methanol and dichloromethane(DCM)extracts from the aerial,root,and flower parts of E.suberosa.Method:Total bioactive contents,high-performance liquid chromatography array(HPLC-PDA)polyphenolic quantification,and ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)analysis were used to evaluate the phytochemical profile.Biological potential was evaluated by determining their antioxidant(DPPH,ABTS,FRAP,CUPRAC,Phosphomolybdenum,and metal chelating)and enzyme inhibitory(cholinesterase,amylase,glucosidase,and tyrosinase)effects.Results:The phenolic(46.26 mg GAE/g extract)and flavonoid(32.46 mg QE/g extract)contents were found to be highest in the methanolic extract of roots(EsR-M).HPLC-PDA analysis determined the presence of numerous bioactive compounds,including catechin,syringic acid,p-hydroxy benzoic acid,gallic acid,vanillic acid,epicatechin,rutin,chlorogenic acid,carvacrol,sinapinic acid,and naringenin in considerable amounts.A total of 143 phytochemicals,belonging to phenolic,flavonoid,coumarin,terpenoid,chalcone,saponin,and glycoside classes,were tentatively identified by UHPLC-MS analysis.Aerial methanolic extract(EsA-M)exhibited highest radical scavenging(DPPH 86.81 mgTE/g extract,ABTS 245.17 mgTE/g extract)as well as reducing potential(FRAP 177.12 mgTE/g extract,CUPRAC 177.12 mgTE/g extract).Likewise,it was also noted to be most active for BChE(5.70 mg GALAE/g extract)and tyrosinase inhibition(148.35 mg KAE/g extract).While,roots-DCM extract(EsR-D)presented considerable inhibition for AChE(4.69 mg GALAE/g extract)and amylase(0.81 mmol ACAE/g extract)enzymes.Coreopsin,davallioside A,and isovitexin were docked to tyrosinase to depict possible interaction.Conclusion:This study has established baseline data on the biological and phytochemical profile of E.suberosa which was found to possess antioxidant and enzym
