Displaying publications 441 - 460 of 1297 in total

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  1. Nurul Mujahidah Ahmad Khairuddin, Amalina Muhammad Afifi, Katayoon Kalantari, Nur Awanis Hashim, Shaza Eva Mohamad
    Sains Malaysiana, 2018;47:1311-1318.
    Chitosan/polyvinyl alcohol (Chitosan/PVA) blended film was prepared by direct blend process and solution casting methods.
    In order to reduce the swelling ratio and enhance the chemical and mechanical stability, Chitosan/PVA film was crosslinked
    with glutaraldehyde in order to produce Chitosan-g-PVA. Bovine serum albumin (BSA) was used as a model protein
    to incorporate into the Chitosan-g-PVA. The chemical structure and morphological characteristics of films were studied
    by FT-IR and scanning electron microscopy (SEM). Mechanical and physical properties of blended films such as tensile
    properties in the dry and wet states, water uptake and water contact angle measurement were characterized. Blending
    PVA and chitosan improved strength and flexibility of the films. Crosslinking with glutaraldehyde further improves the
    tensile strength and decrease the hydrophilicity of films. BSA immobilized on the Chitosan-g-PVA film was calculated as
    BSA encapsulation efficiency.
    Matched MeSH terms: Microscopy, Electron, Scanning
  2. Ida Muryany, Ahmad Rohi Ghazali, Nor Fadilah Rajab, Hing HL, Ina-Salwany, Mohd Zamri Saad, et al.
    Sains Malaysiana, 2018;47:2391-2399.
    Bacterial adhesion to host cells is the most important probiotic character. However, the adhesion of probiotic should not
    affect the viability of the host cells. In this study, Lactobacillus plantarum strain L8, Lactobacillus plantarum strain L20
    and Lactobacillus pentosus strain S1 were tested for their cytotoxic effects through MTT assay and their ability to adhere
    and colonize on HT-29 and CCD-18Co intestinal cells as detected microscopically using light microscopy and Scanning
    Electron Microscopy (SEM). No cytotoxicity effects were observed on both intestinal cells following 24 h treatment with
    all Lactobacillus strains. Additionally, all strains demonstrated strong adhesive activity where more than 100 bacteria
    adhered to both intestinal cells although differences in the adhesion scores observed among different strains. The adhesion
    as observed via SEM showed an autoagreggative pattern and adhered as clusters on the surface of both intestinal cells.
    In conclusion, all three Lactobacillus strains are non-cytotoxic to both cells with strong adhesion ability on intestinal
    cells and this study also proved that Malaysian fermented fish are good source of probiotic bacteria.
    Matched MeSH terms: Microscopy, Electron, Scanning
  3. Anjum H, Johari K, Appusamy A, Gnanasundaram N, Thanabalan M
    J Hazard Mater, 2019 11 05;379:120673.
    PMID: 31254791 DOI: 10.1016/j.jhazmat.2019.05.066
    In this study, the impact of different oxidizing agents on the structural integrity of activated carbon (AC) and multiwalled carbon nanotubes (MWCNTs) was studied for the removal of BTX from aqueous solution. Seven different combinations of green oxidizing agents (mild organic acids) in conjugation with NaOCl (basic oxidizing agent) were used. The modified adsorbents were analyzed by Brunauer, Emmett, and Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR), Boehm titration, Raman spectroscopy, thermal gravimetric analysis (TGA), x-ray diffraction (XRD), zeta potential, and variable pressure field emission scanning electron microscope (VPFESEM). The results suggested that the carbonaceous sorbents modified with combination of citric acid tartaric acid, malic acid and salicylic acid (CTMS-I) showed increased surface area (O-AC: 871.67 m2/g, O-MWCNTs: 336.37 m2/g) and total pore volume (O-AC: 0.59 cm3/g, O-MWCNTs: 0.04 cm3/g), with the significantly improved thermal stability. Preliminary batch adsorption experiments conducted using the present prepared O-AC and O-MWCNTs, showed an improved performance towards the adsorption of BTX, compared with other available reported adsorbents in the literature.
    Matched MeSH terms: Microscopy, Electron, Scanning
  4. Khan MJ, Kumari S, Shameli K, Selamat J, Sazili AQ
    Materials (Basel), 2019 Jul 26;12(15).
    PMID: 31357398 DOI: 10.3390/ma12152382
    Nanoparticles (NPs) are, frequently, being utilized in multi-dimensional enterprises. Silver nanoparticles (AgNPs) have attracted researchers in the last decade due to their exceptional efficacy at very low volume and stability at higher temperatures. Due to certain limitations of the chemical method of synthesis, AgNPs can be obtained by physical methods including sun rays, microwaves and ultraviolet (UV) radiation. In the current study, the synthesis of pullulan mediated silver nanoparticles (P-AgNPs) was achieved through ultraviolet (UV) irradiation, with a wavelength of 365 nm, for 96 h. P-AgNPs were formed after 24 h of UV-irradiation time and expressed spectra maxima as 415 nm, after 96 h, in UV-vis spectroscopy. The crystallographic structure was "face centered cubic (fcc)" as confirmed by powder X-ray diffraction (PXRD). Furthermore, high resolution transmission electron microscopy (HRTEM) proved that P-AgNPs were covered with a thin layer of pullulan, with a mean crystalline size of 6.02 ± 2.37. The average lattice fringe spacing of nanoparticles was confirmed as 0.235 nm with quasi-spherical characteristics, by selected area electron diffraction (SAED) analysis. These green synthesized P-AgNPs can be utilized efficiently, as an active food and meat preservative, when incorporated into the edible films.
    Matched MeSH terms: Microscopy, Electron, Transmission
  5. Ikumapayi OM, Akinlabi ET
    Data Brief, 2019 Feb;22:537-545.
    PMID: 30627604 DOI: 10.1016/j.dib.2018.12.067
    Coconut Shell (CS) as agricultural lignocellulosic biomaterial and agro-waste is predominantly available in India, Malaysia, Nigeria, Thailand, Sri Lanka, and Indonesia. It has proven to have effective durability characteristic, good abstractive resistance, high toughness, and good adsorption properties, and is most suitable for long standing use in many applications such as reinforcement, source of energy, fillers as well as activated carbon and its performance, efficiency and effectiveness depend wholly on whether is in form of nano-, micro-, and macro- particles. In this data, effects of milling time on morphological characteristics was experimented using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and X-Ray Fluorescence (XRF) analyses. The SEM images were taken at magnifications of 1.00kx, 2.00kx and 5.00kx which gives respective 50 µm, 20 µm and 10 µm in different milling time of 0, 20, 40 and 60 mins. Digital Vibratory Disc Milling Machine (VDMM) rated 380 V/50 Hz at 940 rpm was employed for the grinding and the morphology of the milled nanoparticles were characterised. It was revealed from the data collected that 0 min (i.e. 75 µm sieved) has the highest mean area value of 16.105 µm2 and area standard deviation of 200.738 µm2 with least value of a number of particle size distribution of 809 µm. In contrast, 60 mins milled has the lowest values for mean area and area standard deviation of 8.945 µm2 and 115.851 µm2 respectively with the highest number of particle size distribution of 2032 µm. It was observed that milling time increases the number of particle sizes distributions and reduces the area of particle size.
    Matched MeSH terms: Microscopy, Electron, Scanning
  6. Aithal AP, Bairy LK, Seetharam RN, Kumar N
    3 Biotech, 2021 Feb;11(2):107.
    PMID: 33564610 DOI: 10.1007/s13205-021-02640-y
    Bone marrow mesenchymal stromal cells (BM-MSCs) are multipotent stem cells which are ideal candidates for use in regenerative medicine. The objectives of this study were to evaluate the hepatoprotective effect of BM-MSC and its combination treatment with silymarin in carbon tetrachloride (CCl4)-induced liver cirrhosis animal model and to investigate whether tail vein or portal vein infusion was the ideal route for BM-MSC transplantation. 36 female Wistar rats were randomly divided into six groups (n = 6): Group 1 (normal control), Group 2 (received only CCl4, disease model), Group 3 (CCl4 + BM-MSCs through tail vein), Group 4 (CCl4 + BM-MSCs through portal vein), Group 5 (CCl4 + silymarin), Group 6 (CCl4 + BM-MSCs + silymarin). On the 21st day after treatment, blood samples were collected for biochemical estimations. After the experiment, the rats were sacrificed. Liver was dissected out and processed for histopathology and scanning electron microscopy studies. Liver enzyme and marker analysis, histopathological studies indicated that the combination of BM-MSCs and silymarin was effective in treating liver cirrhosis. Transplanted BM-MSCs in combination with silymarin ameliorated the liver tissue damage through their immunoregulatory activities. Among the two routes, the intravenous administration of cells through the tail vein was found to be more effective and safe.
    Matched MeSH terms: Microscopy, Electron, Scanning
  7. Shahida S, Nor Zamzila A, Norlelawati AT, Jamalludin AR, Azliana AF, Zunariah Buyong
    MyJurnal
    Introduction: Over the decades, organic arsenic has been thought to be less toxic than inorganic arsenic.
    Monosodium methylarsonate (MSMA) is a potent organoarsenical herbicide that is still being used in most
    Asian countries. Reported studies on the effects of organic arsenic are mainly to the gastrointestinal system,
    however there are limited research on its impacts to the liver. Therefore, this study aimed to investigate the
    effect of MSMA exposure on hepatocytes and liver sinusoidal endothelial cells (LSEC). Materials and Methods:
    Fourteen Sprague Dawley rats (n=14) were divided equally into arsenic-exposed (n=7) and control (n=7)
    groups. The rats in arsenic-exposed group were given MSMA at 63.20 mg/kg daily for 6 months through oral
    gavage. While the rats in control group were given distilled water ad libitum. At the end of the duration,
    they were euthanized and underwent liver perfusion for tissue preservation. Liver tissues were harvested and
    processed for light microscopy, scanning and transmission electron microscopy. The findings were analysed
    descriptively. Results: MSMA had caused necrotic and apoptotic changes to the liver. Normal organelles
    morphology were loss in the hepatocytes while LSEC revealed defenestration. Conclusion: In this study,
    chronic low dose organic arsenic exposure showed evidence of toxicity to hepatocytes. Interestingly, LSEC
    demonstrated capillarization changes.
    Matched MeSH terms: Microscopy, Electron, Transmission
  8. Beh JH, Lim TH, Lew JH, Lai JC
    Int J Biol Macromol, 2020 Oct 01;160:836-845.
    PMID: 32485260 DOI: 10.1016/j.ijbiomac.2020.05.227
    Sago pith cellulose nanofibril (SPCNF) aerogel derived from sago pith waste (SPW) was successfully produced through three consecutive steps, namely dewaxing and delignification, ultra-sonication and homogenization and freeze drying. The aerogel was characterized using field emission scanning electron microscopy (FE-SEM), Fourier-transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Results of the analyses collectively showed that lignin & hemicellulose were absent in the SPCNF aerogel product which has a high crystallinity index of 88%. The diameters of individual nanofibril constituents of the SPCNF were between 15 and 30 nm and aspect ratios >1000 were observed. The SPCNF aerogel, with a density measured at 2.1 mg/cm3, was efficient in methylene blue (MB) removal with a maximum MB adsorption of 222.2 mg/g at 20 °C. The adsorption of MB onto the SPCNF aerogel was rapid and found to follow a pseudo-second-order kinetic model with the adsorption isotherm being in congruence with the Langmuir model. The SPCNF aerogel exhibited outstanding MB removal efficacies with 5 mg and 20 mg of SPCNF capable of removing over 90% and almost 99% MB, respectively. The optimized pH value and temperature for MB adsorption were determined as pH 7 and 20 °C.
    Matched MeSH terms: Microscopy, Electron, Scanning
  9. Yusof Y, Moosavi S, Johan MR, Badruddin IA, Wahab YA, Hamizi NA, et al.
    ACS Omega, 2021 Feb 16;6(6):4184-4191.
    PMID: 33644542 DOI: 10.1021/acsomega.0c04864
    This study presents the electromagnetic (EM) characterization of a multiwalled carbon nanotubes (MWCNT)-silver nanoparticles (AgNP)-reinforced poly(vinyl alcohol) (PVA) hybrid nanocomposite fabricated via the solution mixing technique. Primarily, the structure and morphological properties of the PVA/MWCNT-AgNP hybrid nanocomposite are confirmed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The complex permittivity (ε*) and permeability (μ*), as well as the electromagnetic scattering parameters are measured using a PNA network analyzer equipped with X-band waveguide. The results showed an enhanced permittivity (ε' ≈ 25) value of the hybrid nanocomposite in the frequency range of 8-12 GHz. However, the permeability decreased to almost zero (μ' ≈ 0.4) since the inclusion of AgNP with an average particle size of 40 nm is not susceptible to magnetization and causes higher magnetic losses (tan δμ) than dielectric losses (tan δε). Remarkably, the hybrid nanocomposite reduced transmission of electromagnetic (EM) wave by nearly 60% in comparison to PVA/MWCNT. This is attributed to the enhanced absorption and reflection at the nanotubes, and metal-dielectric interfaces have induced multiple internal reflections owing to the porous structure of the nanocomposite. The prospect of the PVA/MWCNT-AgNP hybrid nanocomposite is favorable as a thin absorbing material for EM shielding applications.
    Matched MeSH terms: Microscopy, Electron, Scanning
  10. Hashim AN, Salleh MAAM, Sandu AV, Ramli MM, Yee KC, Mohd Mokhtar NZ, et al.
    Materials (Basel), 2021 Feb 05;14(4).
    PMID: 33562471 DOI: 10.3390/ma14040738
    The evolution of internal compressive stress from the intermetallic compound (IMC) Cu6Sn5 growth is commonly acknowledged as the key inducement initiating the nucleation and growth of tin (Sn) whisker. This study investigates the effect of Sn-0.7Cu-0.05Ni on the nucleation and growth of Sn whisker under continuous mechanical stress induced. The Sn-0.7Cu-0.05Ni solder joint has a noticeable effect of suppression by diminishing the susceptibility of nucleation and growth of Sn whisker. By using a synchrotron micro X-ray fluorescence (µ-XRF) spectroscopy, it was found that a small amount of Ni alters the microstructure of Cu6Sn5 to form a (Cu,Ni)6Sn5 intermetallic layer. The morphology structure of the (Cu,Ni)6Sn5 interfacial intermetallic layer and Sn whisker growth were investigated by scanning electron microscope (SEM) in secondary and backscattered electron imaging mode, which showed that there is a strong correlation between the formation of Sn whisker and the composition of solder alloy. The thickness of the (Cu,Ni)6Sn5 IMC interfacial layer was relatively thinner and more refined, with a continuous fine scallop-shaped IMC interfacial layer, and consequently enhanced a greater incubation period for the nucleation and growth of the Sn whisker. These verification outcomes proposes a scientifically foundation to mitigate Sn whisker growth in lead-free solder joint.
    Matched MeSH terms: Microscopy, Electron, Scanning
  11. Ahmed D, Anwar A, Khan AK, Ahmed A, Shah MR, Khan NA
    AMB Express, 2017 Nov 21;7(1):210.
    PMID: 29164404 DOI: 10.1186/s13568-017-0515-x
    Biofilm formation by pathogenic bacteria is one of the major threats in hospital related infections, hence inhibiting and eradicating biofilms has become a primary target for developing new anti-infection approaches. The present study was aimed to develop novel antibiofilm agents against two Gram-positive bacteria; Staphylococcus aureus (ATCC 43300) and Streptococcus mutans (ATCC 25175) using gold nanomaterials conjugated with 3-(diphenylphosphino)propionic acid (Au-LPa). Gold nanomaterials with different sizes as 2-3 nm small and 9-90 nm (50 nm average size) large were stabilized by LPa via different chemical synthetic strategies. The nanomaterials were fully characterized using atomic force microscope (AFM), transmission electron microscope, ultraviolet-visible absorption spectroscopy, and Fourier transformation infrared spectroscopy. Antibiofilm activity of Au-LPa nanomaterials was tested using LPa alone, Au-LPa and unprotected gold nanomaterials against the both biofilm-producing bacteria. The results showed that LPa alone did not inhibit biofilm formation to a significant extent below 0.025 mM, while conjugation with gold nanomaterials displayed manifold enhanced antibiofilm potential against both strains. Moreover, it was also observed that the antibiofilm potency of the Au-LPa nanomaterials varies with size variations of nanomaterials. AFM analysis of biofilms further complemented the assay results and provided morphological aspects of the antibiofilm action of Au-LPa nanomaterials.
    Matched MeSH terms: Microscopy, Electron, Transmission
  12. Mohmad AR, Hamzah AA, Yang J, Wang Y, Bozkurt I, Shin HS, et al.
    Faraday Discuss, 2021 Apr 01;227:332-340.
    PMID: 33523053 DOI: 10.1039/c9fd00132h
    In this work, we report the synthesis and characterization of mixed phase Nb1+xS2 nanoflakes prepared by chemical vapor deposition. The as-grown samples show a high density of flakes (thickness ∼50 nm) that form a continuous film. Raman and X-ray diffraction data show that the samples consist of both 2H and 3R phases, with the 2H phase containing a high concentration of Nb interstitials. These Nb interstitials sit in between the NbS2 layers to form Nb1+xS2. Cross-sectional Energy Dispersive Spectroscopy analysis with transmission electron microscopy suggests that the 2H Nb1+xS2 region is found in thinner flakes, while 3R NbS2 is observed in thicker regions of the films. The evolution of the phase from 2H Nb1+xS2 to 3R NbS2 may be attributed to the change of the growth environment from Nb-rich at the start of the growth to sulfur-rich at the latter stage. It was also found that the incorporation of Nb interstitials is highly dependent on the temperature of the NbCl5 precursor and the position of the substrate in the furnace. Samples grown at high NbCl5 temperature and with substrate located closer to the NbCl5 source show higher incorporation of Nb interstitials. Electrical measurements show linear I-V characteristics, indicating the metallic nature of the Nb1+xS2 film with relatively low resistivity of 4.1 × 10-3Ω cm.
    Matched MeSH terms: Microscopy, Electron, Transmission
  13. AbdulKadir WAFW, Ahmad AL, Boon Seng O
    Membranes (Basel), 2021 Mar 23;11(3).
    PMID: 33807017 DOI: 10.3390/membranes11030228
    The hydrophobic membranes have been widely explored to meet the membrane characteristics for the membrane distillation (MD) process. Inorganic metal oxide nanoparticles have been used to improve the membrane hydrophobicity, but limited studies have used nano clay particles. This study introduces halloysite nanotube (HNT) as an alternative material to synthesis a hydrophobic poly(vinylidene fluoride) (PVDF)-HNT membrane. The PVDF membranes were fabricated using functionalized HNTs (e.g., carnauba wax and 1H,1H,2H,2H-perfluorooctyl-trichlorosilane (FOTS)). The results were determined by Fourier transform infrared-attenuated total reflection, scanning electron microscope, goniometer and porometer to determine the desired hydrophobic membrane for direct contact membrane distillation (DCMD). The addition of FOTS-HNT (fs-HNT) and carnauba wax-HNT (fw-HNT) in the PVDF membrane enhanced the water contact angle (CA) to 127° and 137°, respectively. The presence of fw-HNT in the PVDF membrane exhibited higher liquid entry pressure (LEP) (2.64 bar) compared to fs-HNT in the membrane matrix (1.44 bar). The PVDF/fw-HNT membrane (Pfw-HNT) obtained the highest flux of 7.24 L/m2h with 99.9% salt removal. A stable permeability in the Pfw-HNT membrane was obtained throughout 16 h of DCMD. The incorporation of fw-HNT in the PVDF membrane had improved the anti-wetting properties and the membrane performance with the anti-fouling effect.
    Matched MeSH terms: Microscopy, Electron, Scanning
  14. Lai DS, Osman AF, Adnan SA, Ibrahim I, Alrashdi AA, Ahmad Salimi MN, et al.
    Polymers (Basel), 2021 Mar 15;13(6).
    PMID: 33803984 DOI: 10.3390/polym13060897
    Thermoplastic starch (TPS) hybrid bio-composite films containing microcrystalline cellulose (C) and nano-bentonite (B) as hybrid fillers were studied to replace the conventional non-degradable plastic in packaging applications. Raw oil palm empty fruit bunch (OPEFB) was subjected to chemical treatment and acid hydrolysis to obtain C filler. B filler was ultra-sonicated for better dispersion in the TPS films to improve the filler-matrix interactions. The morphology and structure of fillers were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). TPS hybrid bio-composite films were produced by the casting method with different ratios of B and C fillers. The best ratio of B/C was determined through the data of the tensile test. FTIR analysis proved the molecular interactions between the TPS and the hybrid fillers due to the presence of polar groups in their structure. XRD analysis confirmed the intercalation of the TPS chains between the B inter-platelets as a result of well-developed interactions between the TPS and hybrid fillers. SEM images suggested that more plastic deformation occurred in the fractured surface of the TPS hybrid bio-composite film due to the higher degree of stretching after being subjected to tensile loading. Overall, the results indicate that incorporating the hybrid B/C fillers could tremendously improve the mechanical properties of the films. The best ratio of B/C in the TPS was found to be 4:1, in which the tensile strength (8.52MPa), Young's modulus (42.0 MPa), elongation at break (116.4%) and tensile toughness of the film were increased by 92%, 146%, 156% and 338%, respectively. The significantly improved strength, modulus, flexibility and toughness of the film indicate the benefits of using the hybrid fillers, since these features are useful for the development of sustainable flexible packaging film.
    Matched MeSH terms: Microscopy, Electron, Scanning
  15. Siti Radziah Ismail
    MyJurnal
    Introduction: Trigona thoracica propolis is known to have antimicrobial properties, however its
    antileptospiral properties and its synergistic effects with commonly prescribed antibiotics are scarcely
    documented. This study aimed to evaluate the antileptospiral properties of Trigona thoracica against
    pathogenic Leptospira species (spp.) and to study its synergistic effects with commonly prescribed
    antibiotics. Materials and Methods: The tested Leptospira serovars were Australis, Bataviae, Canicola and
    Javanica. Aqueous extract propolis (AEP) and ethanolic extracts propolis (EEP) were used. Broth dilution
    methods were used to determine the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal
    Concentration (MBC) and the synergistic effects between the propolis and the tested antibiotics. The
    synergistic effects was evaluated by using the fractional inhibitory concentration (FIC) index. Morphological
    changes of the treated Leptospira were observed under a Scanning Electron Microscope (SEM). Results: The
    AEP and EEP were found to have antileptospiral properties against the tested Leptospira spp. The synergy
    result showed that only combination of AEP and penicillin G against serovar Australis has demonstrated
    synergistic effect with the FIC index of 0.38. Morphological study using SEM showed significant structural
    changes of the treated Leptospira spp. Conclusions: The result suggests that Trigona thoracica propolis could
    potentially be used as either a complimentary or an alternative therapeutic agent against pathogenic
    Leptospira spp.
    Matched MeSH terms: Microscopy, Electron, Scanning
  16. Adam H, Gopinath SCB, Arshad MKM, Parmin NA, Hashim U
    Int J Biol Macromol, 2021 Feb 28;171:217-224.
    PMID: 33418041 DOI: 10.1016/j.ijbiomac.2021.01.014
    Misfolding and accumulation of the protein alpha synuclein in the brain cells characterize Parkinson's disease (PD). Electrochemical based aluminum interdigitated electrodes (ALIDEs) was fabricated by using conventional photolithography method and modified the surfaces with zinc oxide and gold nanorod by using spin coating method for the analysis of PD protein biomarker. The device surface modified with gold nanorod of 25 nm diameter was used. The bare devices and the surface modified devices were characterized by Scanning Electron Microscope, 3D-Profilometer, Atomic Force Microscope and high-power microscope. The above measurement was also performed to measure the interaction of antibody with aggregated alpha-synuclein for normal, aggregated and aggregated alpha synuclein in human serum and distinguished against 3 control proteins (PARK1, DJ-1 and Factor IX). The detection limit for normal alpha synuclein was 1 f. with the sensitivity of 1 f. on a linear regression (R2 = 0.9759). The detection limit for aggregated alpha synuclein was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9797). Also, the detection limit of aggregated alpha synuclein in serum was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9739). These results however indicate that, serum has only minimal amount of alpha synuclein.
    Matched MeSH terms: Microscopy, Electron, Scanning
  17. Chen XM, Pang JX, Huang CX, Lundholm N, Teng ST, Li A, et al.
    J Phycol, 2021 Feb;57(1):335-344.
    PMID: 33174223 DOI: 10.1111/jpy.13101
    To explore the species diversity and toxin profile of Pseudo-nitzschia, monoclonal strains were established from Chinese southeast coastal waters. The morphology was examined under light and transmission electron microscopy. The internal transcribed spacer region of ribosomal DNA was sequenced for phylogenetic analyses, and the secondary structure of ITS2 was predicted and compared among allied taxa. A combination of morphological and molecular data showed the presence of two new species, Pseudo-nitzschia hainanensis sp. nov. and Pseudo-nitzschia taiwanensis sp. nov. Pseudo-nitzschia hainanensis was characterized by a dumpy-lanceolate valve with slightly blunt apices and a central nodule, as well as striae comprising two rows of poroids. Pseudo-nitzschia taiwanensis was characterized by a slender-lanceolate valve, and striae comprising one row of split poroids. The poroid structure mainly comprised two sectors. Both taxa constituted their own monophyletic lineage in the phylogenetic analyses inferred from ITS2 rDNA and were well differentiated from other Pseudo-nitzschia species. Morphologically, P. hainanensis and P. taiwanensis could be assigned to the Pseudo-nitzschia delicatissima and the Pseudo-nitzschia pseudodelicatissima complex, respectively. Particulate domoic acid was measured using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), but no detectable pDA was found. With the description of the two new species, the species diversity of genus Pseudo-nitzschia reaches 58 worldwide, among which 31 have been recorded from Chinese coastal waters.
    Matched MeSH terms: Microscopy, Electron, Transmission
  18. Fadzidah Mohd Idris, Khamirul Amin Matori, Idza Riati Ibrahim, Rodziah Nazlan, Mohd Shamsul Ezzad Shafie
    MyJurnal
    The rapid growth of electronic systems and devices operating within the gigahertz (GHz) frequency range has increased electromagnetic interference. In order to eliminate or reduce the spurious electromagnetic radiation levels more closely in different applications, there is strong research interest in electromagnetic absorber technology. Moreover, there is still a lack of ability to absorb electromagnetic radiation in a broad frequency range using thin thickness. Thus, this study examined the effect of incorporating magnetic and dielectric materials into the polymer matrix for the processing of radar absorbing materials. The experiment evaluated the sample preparation with different weight percentages of multi-walled carbon nanotubes (MWCNT) mixed with Ni0.5Zn0.5Fe2O4 (Nickel-Zinc-Ferrite) loaded into epoxy (P) as a matrix. The prepared samples were analysed by examining the reflectivity measurements in the 8 – 18 GHz frequency range and conducting a morphological study using scanning electron microscopy analyses. The correlation of the results showed that different amounts of MWCNT influenced the performance of the microwave absorber. As the amount of MWCNTs increased, the reflection loss (RL) peak shifted towards a lower frequency range and the trend was similar for all thicknesses. The highest RL was achieved when the content of MWCNTs was 2 wt% with a thickness of 2 mm with an RL of – 14 dB at 16 GHz. The 2.5 GHz bandwidth corresponded to the RL below -10 dB (90% absorption) in the range of 14.5 – 17 GHz. This study showed that the proposed experimental route provided flexible absorbers with suitable absorption values by mixing only 2 wt% of MWCNTs.

    Matched MeSH terms: Microscopy, Electron, Scanning
  19. Mali S, Singla S, Tyagi P, Sharma A, Talreja N, Gautam A
    J Indian Soc Pedod Prev Dent, 2021 1 7;38(4):374-380.
    PMID: 33402620 DOI: 10.4103/JISPPD.JISPPD_315_20
    Aim and Objectives: The aim and objectives of this study are to evaluate and compare the effectiveness of Myristica fragrans - Nutmeg, Terminalia chebula - Myrobolan, Ocimum sanctum-tulsi, and 2.5% sodium hypochlorite (NaOCl) on the removal of the smear layer by the scanning electron microscope (SEM).

    Settings and Design: Endodontic treatment aims at disinfection and then obturation of root canal system in to prevent re-infection. Root canal irrigants play a pivotal role in the disinfection process. One of the important properties of an irrigant is the removal of complete smear layer and debris. Smear layer has the potential to protect bacteria within the dentinal tubules; therefore removal may be prudent. Smear layer removal increases the bond strength of resin sealers which results in better apical seal.

    Materials and Methods: Forty extracted single-rooted, primary teeth were allocated randomly into four groups of ten each: Group 1 - NaOCl, Group 2 - Nutmeg, Group 3 - Myrobolan, and Group 4 - Tulsi. Samples were stored in sterile saline (0.9% NaCl) and then decoronated at the level of the cementoenamel junction. Working length was determined followed by appropriate irrigation. The roots were split into two halves with a chisel and were stored in 2.5% glutaraldehyde solution for 24 h. After fixation, the samples were dehydrated in ethanol series (70, 90, and 95 and twice at 100%). Each specimen was mounted on Al stub and sputter coated with a 20 nm layer of gold. Samples were then examined using a SEM quantum 60 at magnification of ×2000.

    Results: Tulsi demonstrated the most statistically significant results followed by myrobolan and nutmeg extract. All herbal extracts were found to be significantly effective than 2.5% NaOCl.

    Conclusion: Tulsi, nutmeg and myrobolan can be effectively used as an irrigant in primary teeth.

    Matched MeSH terms: Microscopy, Electron, Scanning
  20. Sri Raja Rajeswari Mahalingam, Priya Madhavan, Chong, Pei Pei
    MyJurnal
    Introduction: One of the most common aetiology of opportunistic fungal infections in humans is Candida species. The virulence of Candida species is due to repertoire of factors, specifically, the ability to form biofilms. Medical devices such as intravenous catheters, prosthetic heart valves and surgical interventions provide pathogenic microorganisms with a surface to adhere to form biofilm. Fungi present as biofilms are often resistant to antifungal treatment because these biofilms offer a protective barrier that prohibits the drugs to get to the active site of the fungi. The objective of this study is to investigate the biofilm architecture of Candida rugosa (C.rugosa) at different developmental phases and to identify Sessile Minimum Inhibition Concentrations (SMICs) of amphotericin B, caspofungin, fluconazole, and voriconazole for the biofilm of C. rugosa. Methods: Confocal scanning laser microscopy (CSLM) and scanning electron microscopy (SEM) were used to visualize C. rugosa biofilms at different developmental phases. The antifungal susceptibility test was performed using serial doubling dilution. The growth kinetics of Candida biofilms was quantified using XTT reduction assay and crystal violet assay. Results: From the antifungal susceptibility test, the biofilms had SMIC of >16μg/mL for amphotericin B, 6µg/mL for caspofungin, >64μg/mL for fluconazole and >16μg/ mL for voriconazole. From the SEM micrographs, C. rugosa biofilm have a structure composed of an adherent yeast cells and blastopores with hyphal elements. There were significant alterations in the morphology after exposure to antifungal agents. The quantitative measurement of the matrix thickness of embedded yeast cells were obtained from CLSM micrographs. Conclusion: In conclusion, the ability of C. rugosa to form biofilms may attribute to one of the virulence factors that causes reduced susceptibility to antifungal agents.
    Matched MeSH terms: Microscopy, Electron, Scanning
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