Displaying publications 21 - 40 of 154 in total

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  1. Baharin SNA, Muhamad Sarih N, Mohamad S
    Polymers (Basel), 2016 Apr 28;8(5).
    PMID: 30979266 DOI: 10.3390/polym8050117
    Poly(phenyl-(4-(6-thiophen-3-yl-hexyloxy)-benzylidene)-amine) (P3TArH) was successfully synthesized and coated on the surface of Fe₃O₄ magnetic nanoparticles (MNPs). The nanocomposites were characterized by Fourier transform infra-red (FTIR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, analyzer transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). P3TArH-coated MNPs (MNP@P3TArH) showed higher capabilities for the extraction of commonly-used phthalates and were optimized for the magnetic-solid phase extraction (MSPE) of environmental samples. Separation and determination of the extracted phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCP), di-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DNOP), were conducted by a gas chromatography-flame ionization detector (GC-FID). The best working conditions were as follows; sample at pH 7, 30 min extraction time, ethyl acetate as the elution solvent, 500-µL elution solvent volumes, 10 min desorption time, 10-mg adsorbent dosage, 20-mL sample loading volume and 15 g·L-1 concentration of NaCl. Under the optimized conditions, the analytical performances were determined with a linear range of 0.1⁻50 µg·L-1 and a limit of detection at 0.08⁻0.468 µg·L-1 for all of the analytes studied. The intra-day (n = 7) and inter-day (n = 3) relative standard deviations (RSD%) of three replicates were each demonstrated in the range of 3.7⁻4.9 and 3.0⁻5.0, respectively. The steadiness and reusability studies suggested that the MNP@P3TArH could be used up to five cycles. The proposed method was executed for the analysis of real water samples, namely commercial bottled mineral water and bottled fresh milk, whereby recoveries in the range of 68%⁻101% and RSD% lower than 7.7 were attained.
  2. Abdullah M, Suraiya S, Mohamad S, Harun A
    Data Brief, 2020 Aug;31:105949.
    PMID: 32671154 DOI: 10.1016/j.dib.2020.105949
    In this dataset, we report the genome assembly and data analysis of Mycobacterium tuberculosis strain SIT745/EAI1-MYS. Previously, this strain was isolated from a Malaysian patient with extra-pulmonary tuberculosis, and identification of this strain is done by spoligotype patterns with fifteen known Shared International Type (SITs). Further analysis showed that this strain has a remarkable phylogeographical specificity for Malaysia. Based on the National Center for Biotechnology Information (NCBI) nucleotide database information, the complete genome consists of 150 contigs with various sequence lengths and was not assembled. In this assembly, the aforementioned contigs along with reference sequence from Mycobacterium tuberculosis strain H37Rv and Mycobacterium bovis strain AF2122/97 was used for gap closures, were assembled into a single circular chromosome length of approximately 4.42 Mega bases (Mb) with an average GC content of 65.6%. The single circular chromosome was shown to contain 4,009 protein-coding sequences, 3 ribosomal RNAs, 45 transfer RNAs, and 12 superclasses distributed with 277 subsystems which constitute nearly 1900 genes, respectively. The genome information will provide fundamental knowledge of this organism as well as insight for understanding genomic and proteomic profiling, phylogenetic relationship.
  3. Eh Dam VSK, Mohamad S, Mohamad I
    Medeni Med J, 2020;35(2):170-174.
    PMID: 32733768 DOI: 10.5222/MMJ.2020.84594
    Kimura disease (KD) is a rare chronic benign inflammatory disorder of unknown etiology that is prevalent in Asian males. The head and neck region, especially the parotid glands and cervical lymph nodes, are most commonly affected. Diagnosis is based on clinicopathological features, while radiology findings are nonspecific. Although various treatment strategies have been proposed, there is a high recurrence rate. Combination therapy has been found to produce better results than monotherapy. We present a case of KD with huge parotid and cervical lymph node involvement that was treated with a combination of surgery and corticosteroids administered perioperatively.
  4. Mohd NI, Zain NNM, Raoov M, Mohamad S
    R Soc Open Sci, 2018 Apr;5(4):171500.
    PMID: 29765632 DOI: 10.1098/rsos.171500
    A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ionic silicone surfactant, also known as 3-(3-hydroxypropyl-heptatrimethylxyloxane), was chosen as a green extraction solvent because of its structure and properties. The effect of different parameters, such as the type of surfactant, concentration and volume of surfactant, pH, salt, temperature, incubation time and water content on the cloud point extraction of carcinogenic pesticides such as atrazine and propazine, was studied in detail and a set of optimum conditions was established. A good correlation coefficient (R2 ) in the range of 0.991-0.997 for all calibration curves was obtained. The limit of detection was 1.06 µg l-1 (atrazine) and 1.22 µg l-1 (propazine), and the limit of quantitation was 3.54 µg l-1 (atrazine) and 4.07 µg l-1 (propazine). Satisfactory recoveries in the range of 81-108% were determined in milk samples at 5 and 1000 µg l-1, respectively, with low relative standard deviation, n = 3 of 0.301-7.45% in milk matrices. The proposed method is very convenient, rapid, cost-effective and environmentally friendly for food analysis.
  5. Waris KH, Lee VS, Mohamad S
    Environ Sci Pollut Res Int, 2021 Sep;28(35):47785-47799.
    PMID: 34296410 DOI: 10.1007/s11356-021-15434-9
    The aim of this review is to highlight and provide an update on the current development of pesticide remediation methods, focusing on the utilization of different cyclodextrin (CD) molecules. Because of less environmental impact and non-toxic nature, CDs are beneficial for pesticide remediation, reducing environmental risk and health hazards. They are advantageous for the removal of pesticides from contaminated areas, as well as for better pesticide formulation and, posing significant effects on the hydrolysis or degradation of pesticides. The review focuses on the current trend and innovations regarding the methods and strategies employed for using CDs in designing pesticide remediation. Nowadays, in addition to the conventional experimental techniques, molecular simulation approaches are significantly contributing to the study of such phenomena and hence are recognized as a widely used tool.
  6. Ng CS, Mohamad S, Maskon O
    Saudi Med J, 2015 Jun;36(6):743-6.
    PMID: 25987119 DOI: 10.15537/smj.2015.6.11420
    Infective endocarditis could present with a plethora of signs and symptoms. Among the rarity of its presentation is acute confusion associated with neurological deficits, mimicking stroke especially in the young population. We report a case of a 33-year-old young man with acute right-sided hemiparesis and confusion 2 weeks after  tooth extraction. The brain CT and MRI was consistent with new infarction on the left middle and anterior cerebral arteries' territory. Echocardiography unveiled the existence of posterior mitral valve leaflet vegetation. Blood culture grew Group B beta-haemolytic Streptococcus, sensitive to penicillin. Two weeks of intravenous gentamicin with 6 weeks of intravenous benzylpenicillin were administered. In this case report, we highlight the importance of recognition of infective endocarditis in a young patient presenting with cerebrovascular accident following tooth extraction.
  7. Chin YP, Mohamad S, Abas MR
    Int J Mol Sci, 2010 Sep 20;11(9):3459-71.
    PMID: 20957106 DOI: 10.3390/ijms11092459
    The removal of four parabens, methyl-, ethyl-, propyl-, and benzyl-paraben, by β-cyclodextrin (β-CD) polymer from aqueous solution was studied. Different β-CD polymers were prepared by using two cross-linkers, i.e., hexamethylene diisocyanate (HMDI) and toluene-2,6-diisocyanate (TDI), with various molar ratios of cross-linker. β-CD-HMDI polymer with molar ratio of 1:7 and β-CD-TDI polymer with ratio 1:4 gave the highest adsorption of parabens among the β-CD-HMDI and β-CD-TDI series, and were subsequently used for further studies. The adsorption capacity of β-CD-HMDI is 0.0305, 0.0376, 0.1854 and 0.3026 mmol/g for methyl-, ethyl-, propyl-, and benzyl-paraben, respectively. β-CD-TDI have higher adsorption capacities compared with β-CD-HMDI, the adsorption capacity are 0.1019, 0.1286, 0.2551, and 0.3699 mmol/g methyl-, ethyl-, propyl-, and benzyl-paraben respectively. The parameters studied were adsorption capacity, water retention, and reusability. Role of both cross-linker in adsorption, hydrophobicity of polymers, and adsorption capacity of different parabens were compared and discussed. All experiments were conducted in batch adsorption technique. These polymers were applied to real samples and showed positive results.
  8. Zamaili AM, Kueh YC, Mohamad S, Abdullah B
    PMID: 38521652 DOI: 10.1016/j.anorl.2024.02.014
    Endoscopic sinus surgery (ESS) has become an established surgical option in refractory chronic rhinosinusitis (CRS). The goal of this review is to assess the impact of steroid-eluting middle meatal implants after ESS. Cochrane Central Register of Controlled Trials (CENTRAL), SCOPUS, PUBMED, and GOOGLE SCHOLAR were searched from inception to November 2022. All randomised controlled trials (RCTs) involving adult patients receiving ESS for CRS utilising a steroid-eluting middle meatal implants were eligible. The primary outcome was adhesion or synechiae. The secondary outcomes were mucosal inflammation, polyp reformation, the need for oral steroids and additional surgery, postoperative bleeding, sinus pain and discomfort, postoperative sinus-related infection, and change in intraocular pressure. Fourteen full articles were examined out of 496 potential abstracts. Seven RCTs satisfied the criteria. At 30days, steroid-eluting implants reduced adhesion (OR: 0.28, 95% CI: 0.14 to 0.56; P<0.001), mucosal inflammation (MD: -13.09, 95% CI: -18.22 to -7.97; P<0.001), polyp reformation (OR: 0.31; 95% CI: 0.22 to 0.44; P<0.001), and requirement of additional oral steroid (OR: 0.44; 95% CI: 0.25 to 0.78; P=0.005) or surgery (OR: 0.25; 95% CI: 0.12 to 0.50; P<0.001). While their use for adhesion (OR: 0.24; 95% CI: 0.11 to 0.54; P<0.001) and polyp reformation (OR: 0.24; 95% CI: 0.12 to 0.51; P<0.001) were favourable, there was no difference in mucosal inflammation (MD: -5.68, 95% CI: -12.39 to 1.03; P=0.100) or the need for surgery (OR: 0.96; 95% CI: 0.07 to 12.37; P=0.980) when evaluated after 30days. Overall, the findings suggest that steroid-eluting middle meatal implants improve ESS outcomes by lowering rates of adhesion formation, postoperative medical and surgical interventions, recurrent polyposis, and inflammation, while having no significant negative impact in the immediate postoperative period. More research is needed into the long-term impacts.
  9. Raof SF, Mohamad S, Abas MR
    Int J Mol Sci, 2013 Mar 14;14(3):5952-65.
    PMID: 23493059 DOI: 10.3390/ijms14035952
    A molecularly imprinted silica gel sorbent for selective removal of 2-Hydroxybenzoic acid (2-HA) was prepared by a surface imprinting technique with a sol-gel process. The 2-HA molecularly imprinted silica gel (2-HA-MISG) sorbent was evaluated by various parameters, including the influence of pH, static, kinetic adsorption and selectivity experiments. The optimum adsorption capacity to the 2-HA appeared to be around pH 2 by the polymer. Morevoer, the imprinted sorbent displayed fast uptake kinetics, obtained within 20 min. The adsorption capacity of the 2-HA-MISG (76.2 mg g-1) was higher than that of the non-imprinted silica gel (NISG) (42.58 mg g-1). This indicates that the 2-HA-MISG offers a higher affinity for 2-HA than the NISG. The polymer displays good selectivity and exhibits good reusability. Experimental results show the potential of molecularly imprinted silica sorbent for selective removal of 2-HA.
  10. Mohamad S, Azmi NC, Noordin R
    J Clin Microbiol, 2009 Jun;47(6):1712-7.
    PMID: 19369434 DOI: 10.1128/JCM.00001-09
    Diagnosis of human toxocariasis currently relies on serologic tests that use Toxocara excretory-secretory (TES) antigen to detect immunoglobulin G (IgG) antibodies to the larvae. In general, however, these assays do not have adequate specificity for use in countries in which other soil-transmitted helminths are endemic. The use of recombinant antigens in these assays, however, is promising for improving the specificity of the diagnosis of toxocariasis. Toward this goal, we developed an IgG4 enzyme-linked immunosorbent assay (ELISA) involving three recombinant antigens: rTES-30USM (previously produced), rTES-26, and rTES-120. The latter two antigens were produced by reverse transcription-PCR cloning; subcloned into glutathione S-transferase (GST)-tagged and His-tagged prokaryotic expression vectors, respectively; and expressed in Escherichia coli. The recombinant proteins were subsequently purified by affinity chromatography using GST and His-Trap resins. The diagnostic potential of each purified recombinant antigen was tested with various immunoglobulin classes (IgG, IgM, and IgE) and IgG subclasses. The IgG4 ELISA was determined to have the highest specificity and was further evaluated using a panel of serum samples. The rTES-26 IgG4 ELISA showed 80.0% (24/30 samples positive) sensitivity, and both the rTES-30USM IgG4 ELISA and rTES-120 IgG4 ELISA had 93.0% (28/30) sensitivity. Combined use of rTES-120 and rTES-30 IgG4 ELISA for the diagnosis of toxocariasis provided 100% sensitivity. The specificities of rTES-26, rTES-30USM, and rTES-120 antigens were 96.2%, 93.9%, and 92.0%, respectively. These results indicate that the development of a diagnostic test using the three recombinant antigens will allow for more-accurate detection of toxocariasis.
  11. Muniandy Y, Mohamad S, Raoov M
    RSC Adv, 2024 Apr 10;14(17):11977-11985.
    PMID: 38623288 DOI: 10.1039/d4ra00940a
    A green method based on magnetic micro-solid phase extraction (MNP-TW-μ-SPE) of tea waste impregnated with magnetic nanoparticles (MNP-TW) was developed for the extraction of ibuprofen (IBP) in water samples prior to UV-Vis spectrophotometric analysis. Experimenting parameters that affect the extraction efficiency of IBP, such as pH of the sample solution, sorbent dosage, extraction time, ionic strength, volume of the sample, type of desorption solvent, desorption time, and desorption volume, were studied and optimized in detail. The characterization studies for the MNP-TW were carried out by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectrometry (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, a vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). Under the optimum conditions, the linearity ranges from 30 to 700 μg L-1 for IBP, with determination coefficients (R2) of 0.9983. The limit of detection (LOD) and limit of quantification (LOQ) were 9.40 μg L-1 and 28.50 μg L-1, respectively. The method also demonstrated good precision in reproducibility (RSD ≤ 1.53%), repeatability (RSD ≤ 1.48%), and recovery (86-115%). This method represents the advantages of low solvent consumption, flexibility, and better sensitivity compared to other studies employing spectrophotometric analysis. The usage of tea waste in the extraction process presents many advantages, as it is biodegradable, versatile, and contributes to an intelligent and sustainable economic strategy projected toward a circular economy approach.
  12. Subramaniam P, Mohamad S, Alias Y
    Int J Mol Sci, 2010 Sep 28;11(10):3675-85.
    PMID: 21152293 DOI: 10.3390/ijms11103675
    The supramolecular structure of the inclusion complex of β-cyclodextrin (β-CD) with 1,1',2,2'-tetramethyl-3,3'-(p-phenylenedimethylene) diimidazolium dibromide (TetraPhimBr), a dicationic ionic liquid, has been investigated. The inclusion complex with 1:1 molar ratio was prepared by a kneading method. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) analysis, (1)H NMR and thermogravimetric analysis (TGA) confirmed the formation of the inclusion complex. The results showed that the host-guest system is a fine crystalline powder. The decomposition temperature of the inclusion complex is lower than that of its parent molecules, TetraPhimBr and β-CD individually.
  13. Belhaj AF, Elraies KA, Alnarabiji MS, Abdul Kareem FA, Shuhli JA, Mahmood SM, et al.
    Chem Eng J, 2021 Feb 15;406:127081.
    PMID: 32989375 DOI: 10.1016/j.cej.2020.127081
    Throughout the application of enhanced oil recovery (EOR), surfactant adsorption is considered the leading constraint on both the successful implementation and economic viability of the process. In this study, a comprehensive investigation on the adsorption behaviour of nonionic and anionic individual surfactants; namely, alkyl polyglucoside (APG) and alkyl ether carboxylate (AEC) was performed using static adsorption experiments, isotherm modelling using (Langmuir, Freundlich, Sips, and Temkin models), adsorption simulation using a state-of-the-art method, binary mixture prediction using the modified extended Langmuir (MEL) model, and artificial neural network (ANN) prediction. Static adsorption experiments revealed higher adsorption capacity of APG as compared to AEC, with sips being the most fitted model with R2 (0.9915 and 0.9926, for APG and AEC respectively). It was indicated that both monolayer and multilayer adsorption took place in a heterogeneous adsorption system with non-uniform surfactant molecules distribution, which was in remarkable agreement with the simulation results. The (APG/AEC) binary mixture prediction depicted contradictory results to the experimental individual behaviour, showing that AEC had more affinity to adsorb in competition with APG for the adsorption sites on the rock surface. The adopted ANN model showed good agreement with the experimental data and the simulated adsorption values for APG and AEC showed a decreasing trend as temperature increases. Simulating the impact of binary surfactant adsorption can provide a tremendous advantage of demonstrating the binary system behaviour with less experimental data. The utilization of ANN for such prediction procedure can minimize the experimental time, operating cost and give feasible predictions compared to other computational methods. The integrated workflow followed in this study is quite innovative as it has not been employed before for surfactant adsorption studies.
  14. Rafiq MT, Hamid MSA, Hafiz E, Chaudhary FA, Khan MI
    Curr Rheumatol Rev, 2021;17(4):421-427.
    PMID: 34315379 DOI: 10.2174/1573397117666210727095552
    INTRODUCTION: Knee Osteoarthritis (OA) is a weight-bearing joint disease and is more common in overweight and obese persons. The objective of the study was to assess the feasibility and acceptability of Instructions of Daily Care (IDC) on pain, mobility, and Body Mass Index (BMI) among knee OA participants who are overweight or obese.

    MATERIALS AND METHODS: The study was an open-label randomized controlled trial of six weeks. Forty overweight and obese participants with knee OA were randomly divided into two groups by a computer-generated number. The participants in the Instruction Group (IG) were provided with leaflets explaining IDC for the duration of six weeks. Both groups were instructed to take low doses of the non-steroid anti-inflammatory drug (NSAIDs) on alternate days. The outcome measures were pain, mobility and BMI. The feasibility and acceptability of knee pain and mobility were assessed using a questionnaire designed by experts in rehabilitation.

    RESULTS: Participants in the IG reported more statistically significant pain relief as assessed by the Western Ontario and McMaster Universities Osteoarthritis Index score (p=0.001) and improvement in mobility (p=0.000) assessed by the Timed Up and Go test score after six weeks compared to the Control Group (CG). Both groups did not demonstrate any significant change in BMI (p-value > 0.05). The results of descriptive statistics showed a significantly higher satisfaction score for participants who received a combination of IDC and NSAIDs, indicating an acceptable intervention.

    CONCLUSION: The IDC is effective and acceptable in terms of improving pain and mobility and should be recommended as the usual care of treatment.

  15. Gabris MA, Rezania S, Rafieizonooz M, Khankhaje E, Devanesan S, AlSalhi MS, et al.
    Environ Res, 2022 May 01;207:112209.
    PMID: 34653412 DOI: 10.1016/j.envres.2021.112209
    The present study reports the successful functionalization/magnetization of bio-polymer to produce chitosan-magnetic graphene oxide grafted polyaniline doped with cobalt oxide (ChMGOP-Co3O4). Analytical techniques furrier transform infra-red (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used to confirm the formation of ChMGOP-Co3O4. The effects of several experimental factors (solution pH, adsorbent dosage and coexisting ions) on the uptake of As(V) ions using ChMGOP-Co3O4 were examined through batch experiments. As(V) removal process was validated by experimentally and theoretically investigating the adsorption capacity, rate, and thermal effects. Thermodynamic parameters such as free energy (ΔG°), entropy (ΔS°) and enthalpy (ΔH°) were also calculated and were used to explain the mechanism of adsorption. Based on the results, the sorbent showed a high adsorption capacities (90.91 mg/g) at favorable neutral pH and superior removal efficiencies as high as 89% within 50 min. In addition, the adsorption isotherm followed the Langmuir isotherm in compare to the Freundlich, due to its higher R2 value (0.992 
  16. Rahim EA, Noh MS, Ngah NA, Suraini MS, Yusof MM
    Acta Radiol Open, 2017 Jul;6(7):2058460117716705.
    PMID: 28811928 DOI: 10.1177/2058460117716705
    Hepatocellular carcinoma (HCC) is the commonest primary tumor of the liver and carries a poor prognosis when diagnosed late or left untreated. Treatment relies heavily on the stage of the tumor when diagnosed. Extrahepatic metastasis is known to occur; these are mainly reported via autopsy studies or isolated case reports. Knowledge of extrahepatic metastasis is crucial in order to avoid unnecessary surgery. We report a rare case of a patient at our center, diagnosed to have HCC, who underwent treatment successfully, only to come back with extrahepatic metastasis to the skeletal muscles.
  17. Abd Karim S, Hamid MS, Choong A, Ooi MY, Usman J
    J Sports Med Phys Fitness, 2023 May;63(5):674-684.
    PMID: 37132278 DOI: 10.23736/S0022-4707.22.14376-8
    BACKGROUND: Supraspinatus tendinopathy is a significant cause of pain and function loss. It has been suggested that platelet-rich plasma (PRP) and prolotherapy are effective treatments for this condition. This study was done to assess and compare the effects of PRP and prolotherapy on shoulder function and pain. The secondary aim was to evaluate the effect of the treatment on shoulder range of motion, supraspinatus tendon thickness, patient satisfaction, and adverse effects.

    METHODS: This was a randomized, double-blind clinical trial. The study included 64 patients over the age of 18 who had supraspinatus tendinopathy and had not responded to at least three months of conventional treatment. Patients were assigned to either receive 2 mL of PRP (N.=32) or prolotherapy (N.=32). The Shoulder Pain and Disability Index (SPADI) and the Numerical Rating Scale (NRS) were the primary outcomes. Secondary outcomes included shoulder range of motion (ROM), supraspinatus tendon thickness, and adverse effects, which were measured at baseline, 3, 6, and 6 months after injection. At six months, patient satisfaction was assessed.

    RESULTS: Repeated measures ANOVA showed there was a statistically significant effect of time on total SPADI scores (F [2.75, 151.11], = 2.85, P=0.040) and the NRS (F [2.69, 147.86], = 4.32, P=0.008) within each group. There were no other significant changes over time or between groups. Significantly more patients in the PRP group experienced increased pain lasting less than two weeks after injection (χ2=11.94, P=0.030).

    CONCLUSIONS: PRP and prolotherapy resulted in improved shoulder function and pain for patients with chronic supraspinatus tendinopathy who did not response to conventional treatment.

  18. Shanmugam P, Parasuraman B, Boonyuen S, Thangavelu P, AlSalhi MS, Zheng ALT, et al.
    Environ Geochem Health, 2024 Feb 17;46(3):92.
    PMID: 38367085 DOI: 10.1007/s10653-024-01871-1
    A facile and cost-effective hydrothermal followed by precipitation method is employed to synthesize visible light-driven ZnS-Ag ternary composites supported on carbon aerogel (CA). Extensive studies were conducted on the structural, morphological, and optical properties, confirming the successful formation of ternary nanocomposites. The obtained results evidently demonstrate the successful loading of ZnS and Ag onto the surface of the CA. High-resolution transmission electron microscopy analysis revealed that ZnS and Ag nanoparticles (AgNPs) were uniformly distributed on the surface of the CA with an average diameter of 18 nm. The biomass-derived CA, containing a hierarchical porous nano-architecture and an abundant number of -NH2 functional groups on the surface, can greatly prevent the agglomeration, stability and reduce particle size. Brunauer-Emmett-Teller analysis results indicated specific surface areas of 4.62 m2 g-1 for the CA, 48.50 m2 g-1 for the CA/ZnS composite, and 62.62 m2 g-1 for the CA/ZnS-Ag composite. These values demonstrate an increase in surface area upon the incorporation of ZnS and Ag into the CA matrix. Under visible light irradiation, the synthesized CA/ZnS-Ag composites displayed remarkably improved photodegradation efficiency of methylene blue (MB). Among the tested samples, the CA/ZnS-Ag composites exhibited the highest percentage of photodegradation efficiency, surpassing ZnS, CA, and CA/ZnS. The obtained percentages of degradation efficiency for CA, ZnS, CA/ZnS, and CA/ZnS-Ag composites were determined as 26.60%, 52.12%, 68.39%, and 98.64%, respectively. These results highlight the superior photocatalytic performance of the CA/ZnS-Ag composites in the degradation of MB under visible light conditions. The superior efficiency of the CA/ZnS-Ag composite can be attributed to multiple factors, including its elevated specific surface area, inhibition of electron-hole pair recombination, and enhanced photon absorption within the visible light spectrum. The CA/ZnS-Ag composites displayed consistent efficiency over multiple cycles, confirming their stable performance, reusability, and enduring durability, thereby showcasing the robust nature of this composite material.
  19. Mirsafian H, Mat Ripen A, Merican AF, Bin Mohamad S
    ScientificWorldJournal, 2014;2014:482463.
    PMID: 25254246 DOI: 10.1155/2014/482463
    Beta-amyloid precursor protein cleavage enzyme 1 (BACE1) and beta-amyloid precursor protein cleavage enzyme 2 (BACE2), members of aspartyl protease family, are close homologues and have high similarity in their protein crystal structures. However, their enzymatic properties differ leading to disparate clinical consequences. In order to identify the residues that are responsible for such differences, we used evolutionary trace (ET) method to compare the amino acid conservation patterns of BACE1 and BACE2 in several mammalian species. We found that, in BACE1 and BACE2 structures, most of the ligand binding sites are conserved which indicate their enzymatic property of aspartyl protease family members. The other conserved residues are more or less randomly localized in other parts of the structures. Four group-specific residues were identified at the ligand binding site of BACE1 and BACE2. We postulated that these residues would be essential for selectivity of BACE1 and BACE2 biological functions and could be sites of interest for the design of selective inhibitors targeting either BACE1 or BACE2.
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