MyMedR

Displaying publications 41 - 60 of 1671 in total

Abstract:

Sort:

SELLERS' TECHNIQUE; A RAPID MICROSCOPICAL EXAMINATION FOR NEGRI BODIES IN THE DIAGNOSIS OF RABIES

TAN D

Med J Malaysia, 1964 Sep;19:67-8.
PMID: 14240066
Matched MeSH terms: Microscopy*
Fulltext Observation of cotton-like bismuth oxide (β-Bi2O2.5) prepared via pulsed laser ablation deposition

Waje, Samaila Bawa, Noorhana Yahya, Irmawati Ramli

Pertanika Journal of Science & Technology, 2009;17(2):-.
MyJurnal

Monoclinic bismuth oxide (α-Bi2O3) nanoparticles were prepared via precipitation method and
irradiated with a pulsed laser forming thin films. Their phase and surface morphological properties
were investigated using x-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron
microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM). The XRD
analysis shows the phase transformation to a partially crystalline tetragonal phase β-Bi2O3 thin film.
The SEM micrograph of the nanoparticles, with an average crystal size of 72 nm, was seen to form
a thin film with a peculiar structure, coined as “cotton-like”, is attributed to the high surface energy
absorbed by the nanoparticles during ablation. The HR-TEM micrograph shows the particulate with
a clearly defined interlayer spacing.

Matched MeSH terms: Microscopy, Atomic Force; Microscopy, Electron, Transmission
Compositional engineering of VOPcPhO-TiO2nano-composite to reduce the absolute threshold value of humidity sensors

Azmer MI, Aziz F, Ahmad Z, Raza E, Najeeb MA, Fatima N, et al.

Talanta, 2017 Nov 01;174:279-284.
PMID: 28738579 DOI: 10.1016/j.talanta.2017.06.016

This research work demonstrates compositional engineering of an organic-inorganic hybrid nano-composites for modifying absolute threshold of humidity sensors. Vanadyl-2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO), an organic semiconductor, doped with Titanium-dioxide nanoparticles (TiO2NPs) has been employed to fabricate humidity sensors. The morphology of the VOPcPhO:TiO2nano-composite films has been analyzed by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The sensors have been examined over a wide range of relative humidity i.e. 20-99% RH. The sensor with TiO2(90nm) shows reduced sensitivity-threshold and improved linearity. The VOPcPhO:TiO2(90nm) nano-composite film is comprised of uniformly distributed voids which makes the surface more favorable for adsorption of moisture content from environment. The VOPcPhO:TiO2nano-composite based sensor demonstrates remarkable improvement in the sensing parameter when equated with VOPcPhO sensors.

Matched MeSH terms: Microscopy, Electron, Scanning; Microscopy, Atomic Force
Fulltext Assessments of Secondary Reinforcement of Epoxy Matrix-Glass Fibre Composite Laminates through Nanosilica (SiO₂)

Lazar PJL, Sengottuvelu R, Natarajan E

Materials (Basel), 2018 Nov 05;11(11).
PMID: 30400592 DOI: 10.3390/ma11112186

The principal objective of this research work was to investigate the results of impregnating epoxy matrix-glass fibre composite laminates with nanosilica as secondary reinforcement. 0.5, 0.75, 1 and 3 wt% nanosilica was used and thereafter properties of composites were assessed through tensile, three point bending, quasi static indentation tests and dynamic mechanical analysis. Scanning electron microscope examinations were done on fracture surfaces and failure modes were analyzed. The internal failures of the composite due to quasi-static indentation were evaluated through C-Scan. Among samples of different weight fractions, 0.75 wt% nanosilica reinforced composite laminates exhibited substantial increase of 42% in tensile strength and 39.46% in flexural strength. The reduction in glass transition temperature (Tg), increase in storage modulus (E'), loss modulus (E″) and damping factor (tan δ) were also observed. Quasi-static indentation assessments revealed that energy absorption property was enhanced significantly by 53.97%. Hence nanosilica up to 0.75 wt% can be used as a potential candidate for secondary reinforcement in epoxy composite laminates.

Matched MeSH terms: Microscopy, Electron, Scanning; Microscopy, Electron, Transmission
Effect of synthesis condition on the growth of SWCNTs via catalytic chemical vapour deposition

Toussi SM, Fakhruâ€™L-Razi A, Luqman Chuah A, Suraya A

Sains Malaysiana, 2011;40.

Single-walled carbon nanotubes (SWCNTs) were synthesized by catalytic chemical vapor deposition (CCVD) of ethanol (C2H5OH) over Fe-Mo-MgO catalyst by using argon as a carrier gas. The reaction conditions are important factors that influence the yield and quality of carbon nanotubes. The effects of temperature and flow rate of carrier gas were investigated to increase the yield of carbon nanotubes. The synthesized carbon nanotubes were characterized by scanning electron microscopy, transmission electron microscopy, X-Ray diffraction and thermo-gravimetric analysis. The results showed that the growth of carbon nanotubes was effectively influenced by the reaction ambience and the synthesis condition. The temperature and flow rate of carrier gas played a key role in the yield and quality of synthesized CNTs. The estimated yield of synthesized carbon nanotubes was almost over 70%.

Matched MeSH terms: Microscopy, Electron, Scanning; Microscopy, Electron, Transmission
Taxonomic significance of cypsela morphology in tribe Cichoreae (Asteraceae) using light microscopy and scanning electron microscopy

Ayaz S, Ahmad M, Zafar M, Ali MI, Sultana S, Mustafa MRU, et al.

Microsc Res Tech, 2020 Mar;83(3):239-248.
PMID: 31713962 DOI: 10.1002/jemt.23407

The current study deals with the detailed morphology investigation of eight Cypsela species belonging to tribe Cichoreae. The different Cypsela types were described, explained, compared, and their taxonomic significance is discussed in detail. Light microscopy (LM) and scanning electron microscopy (SEM) have been used to highlight quantitative and qualitative characters of underestudied species. Cypsela exhibit great diversity in macro and micromorphological features such as shape, color, length, width, anticlinal and periclinal wall patterns, surface patterns, epicuticular projections. Majority of Cypsela species were brownish in color and their size ranges from 2.16 to 3.98 mm in length and 1.16 to 0.82 mm in breadth. A great diversity in Cypsela shapes like oblanceolate to obovate, obovoid to cylindrical, obvate, narrowly lanceolate were observed. Most of the platelets having epicuticular projections were observed. The surface pattern on the cypsela surface varied from rugose papillate, verrucose papillate, and striated. On the basis of considerable variations observed, the present study can assist as useful constraints at various taxonomic levels. The aim of the present study is to provide a comprehensive description of the Cypsela morphology and to determine the extent to which these micro morphological data can be used as a taxonomic character to delineate various taxa belonging to the tribe Cichoreae.

Matched MeSH terms: Microscopy; Microscopy, Electron, Scanning
Fulltext Minimum inhibitory concentration of nano-silver bactericides for beneficial microbes and its effect on Ralstonia solanacearum and seed germination of Japanese Cucumber (Cucumis sativus)

Sotoodehnia P, Mazlan N, Mohd Saud H, Samsuri WA, Habib SH, Soltangheisi A

PeerJ, 2019;7:e6418.
PMID: 30918747 DOI: 10.7717/peerj.6418

Background: Plant growth-promoting rhizobacteria (PGPR) are highly promising biofertilizers that contribute to eco-friendly sustainable agriculture. There have been many reports on the anti-microbial properties of nanoparticles (NPs). Toxic effects of NPs under laboratory conditions have also reported; however, there is a lack of information about their uptake and mobility in organisms under environmental conditions. There is an urgent need to determine the highest concentration of NPs which is not detrimental for growth and proliferation of PGPR.
Methods: Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to measure the size and shape of NPs. Minimum inhibitory concentrations (MIC) of nano-silver on selected beneficial microbes and Ralstonia solanacearum were measured using the microdilution broth method. The percentage of seed germination was measured under in vitro conditions.
Results: NPs were spherical with a size of 16 ± 6 nm. Nano-silver at 12-40 mg l-1 inhibited the growth of bacteria. Seed application at 40 mg l-1 protected seeds from R. solanacearum and improved the rate of seed germination.

Matched MeSH terms: Microscopy, Electron, Scanning; Microscopy, Electron, Transmission
Production and characterization of the defatted oil palm shell nanoparticles

Abdul Khalil HPS, Md. Sohrab Hossain, Nur Amiranajwa AS, Nurul Fazita MR, Mohamad Haafiz MK, Suraya N, et al.

Sains Malaysiana, 2016;45:833-839.

This present study was conducted to produce defatted oil palm shell (OPS) nanoparticles. Wherein, the OPS nanoparticles
were defatted by solvent extraction method. Several analytical methods including transmission electron microscope (TEM),
X-ray diffraction (XRD), particle size analyzer, scanning electron microscope (SEM), SEM energy dispersive X-ray (SEM-EDX)
and thermal gravimetric analyzer (TGA) were used to characterize the untreated and defatted OPS nanoparticles. It was
found that 75.3% OPS particles were converted into nanoparticles during ball milling. The obtained OPS nanoparticles had
smaller surface area with angular, irregular and crushed shapes under SEM view. The defatted OPS nanoparticles did not
show any agglomeration during TEM observation. However, the untreated OPS nanoparticles had higher decomposition
temperature as compared to the defatted OPS nanoparticles. Based on the characterization results of the OPS nanoparticles,
it is evident that the defatted OPS nanoparticles has the potentiality to be used as filler in biocomposites

Matched MeSH terms: Microscopy, Electron, Scanning; Microscopy, Electron, Transmission
Fulltext Features of DNA-Montmorillonite Binding Visualized by Atomic Force Microscopy

Kraevsky SV, Barinov NA, Morozova OV, Palyulin VV, Kremleva AV, Klinov DV

Int J Mol Sci, 2023 Jun 06;24(12).
PMID: 37372975 DOI: 10.3390/ijms24129827

In the present work, complexes of DNA with nano-clay montmorillonite (Mt) were investigated by means of atomic force microscopy (AFM) under various conditions. In contrast to the integral methods of analysis of the sorption of DNA on clay, AFM allowed us to study this process at the molecular level in detail. DNA molecules in the deionized water were shown to form a 2D fiber network weakly bound to both Mt and mica. The binding sites are mostly along Mt edges. The addition of Mg2+ cations led to the separation of DNA fibers into separate molecules, which bound mainly to the edge joints of the Mt particles according to our reactivity estimations. After the incubation of DNA with Mg2+, the DNA fibers were capable of wrapping around the Mt particles and were weakly bound to the Mt edge surfaces. The reversible sorption of nucleic acids onto the Mt surface allows it to be used for both RNA and DNA isolation for further reverse transcription and polymerase chain reaction (PCR). Our results show that the strongest binding sites for DNA are the edge joints of Mt particles.

Matched MeSH terms: Microscopy, Atomic Force/methods
Fulltext A selective ultrahigh responding high temperature ethanol sensor using TiO2 nanoparticles

Arafat MM, Haseeb AS, Akbar SA

Sensors (Basel), 2014;14(8):13613-27.
PMID: 25072346 DOI: 10.3390/s140813613

In this research work, the sensitivity of TiO2 nanoparticles towards C2H5OH, H2 and CH4 gases was investigated. The morphology and phase content of the particles was preserved during sensing tests by prior heat treatment of the samples at temperatures as high as 750 °C and 1000 °C. Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis were employed to characterize the size, morphology and phase content of the particles. For sensor fabrication, a film of TiO2 was printed on a Au interdigitated alumina substrate. The sensing temperature was varied from 450 °C to 650 °C with varying concentrations of target gases. Results show that the sensor has ultrahigh response towards ethanol (C2H5OH) compared to hydrogen (H2) and methane (CH4). The optimum sensing temperature was found to be 600 °C. The response and recovery times of the sensor are 3 min and 15 min, respectively, for 20 ppm C2H5OH at the optimum operating temperature of 600 °C. It is proposed that the catalytic action of TiO2 with C2H5OH is the reason for the ultrahigh response of the sensor.

Matched MeSH terms: Microscopy, Electron, Scanning/methods; Microscopy, Electron, Transmission/methods
Fulltext Characterization of magnetic nanoparticle by dynamic light scattering

Lim J, Yeap SP, Che HX, Low SC

Nanoscale Res Lett, 2013;8(1):381.
PMID: 24011350 DOI: 10.1186/1556-276X-8-381

Here we provide a complete review on the use of dynamic light scattering (DLS) to study the size distribution and colloidal stability of magnetic nanoparticles (MNPs). The mathematical analysis involved in obtaining size information from the correlation function and the calculation of Z-average are introduced. Contributions from various variables, such as surface coating, size differences, and concentration of particles, are elaborated within the context of measurement data. Comparison with other sizing techniques, such as transmission electron microscopy and dark-field microscopy, revealed both the advantages and disadvantages of DLS in measuring the size of magnetic nanoparticles. The self-assembly process of MNP with anisotropic structure can also be monitored effectively by DLS.

Matched MeSH terms: Microscopy, Electron, Transmission
Fulltext SnO2/Pt thin film laser ablated gas sensor array

Shahrokh Abadi MH, Hamidon MN, Shaari AH, Abdullah N, Wagiran R

Sensors (Basel), 2011;11(8):7724-35.
PMID: 22164041 DOI: 10.3390/s110807724

A gas sensor array was developed in a 10 × 10 mm(2) space using Screen Printing and Pulse Laser Ablation Deposition (PLAD) techniques. Heater, electrode, and an insulator interlayer were printed using the screen printing method on an alumina substrate, while tin oxide and platinum films, as sensing and catalyst layers, were deposited on the electrode at room temperature using the PLAD method, respectively. To ablate SnO(2) and Pt targets, depositions were achieved by using a 1,064 nm Nd-YAG laser, with a power of 0.7 J/s, at different deposition times of 2, 5 and 10 min, in an atmosphere containing 0.04 mbar (4 kPa) of O(2). A range of spectroscopic diffraction and real space imaging techniques, SEM, EDX, XRD, and AFM were used in order to characterize the surface morphology, structure, and composition of the films. Measurement on the array shows sensitivity to some solvent and wood smoke can be achieved with short response and recovery times.

Matched MeSH terms: Microscopy, Electron, Scanning/methods; Microscopy, Atomic Force/methods
A review of histomorphometric analysis techniques for assessing implant-soft tissue interface

Chai WL, Moharamzadeh K, Brook IM, Van Noort R

Biotech Histochem, 2011 Aug;86(4):242-54.
PMID: 20392135 DOI: 10.3109/10520291003707916

The success of dental implant treatment depends on the healing of both hard and soft tissues. While osseointegration provides initial success, the biological seal of the peri-implant soft tissue is crucial for maintaining the long term success of implants. Most studies of the biological seal of peri-implant tissues are based on animal or monolayer cell culture models. To understand the mechanisms of soft tissue attachment and the factors affecting the integrity of the soft tissue around the implants, it is essential to obtain good quality histological sections for microscopic examination. The nature of the specimens, however, which consist of both metal implant and soft peri-implant tissues, poses difficulties in preparing the specimens for histomorphometric analysis of the implant-soft tissue interface. We review various methods that have been used for the implant-tissue interface investigation with particular focus on the soft tissue. The different methods are classified and the advantages and limitations of the different techniques are highlighted.

Matched MeSH terms: Microscopy, Electron, Scanning/methods*; Microscopy, Confocal/methods*
Comparative study between dense and porous hydroxyapatite using light and scanning electron microscopy

Pohchi A, Suzina AH, Samsudin AR, Al-Salihi KA

Med J Malaysia, 2004 May;59 Suppl B:151-2.
PMID: 15468863

This in vivo study revealed that porous hydroxyapatite (PHA) and dense hydroxyapatite (DHA) are good implant materials that can accelerate bone healing and resorbed in acceptable time. But there were differences in the mechanism of the resorption of DHA and PHA due to variability in the physical properties and osteogenicity.

Matched MeSH terms: Microscopy*; Microscopy, Electron, Scanning*
Fulltext Synthesis of Highly Crystalline Multilayered Boron Niride Microflakes

Ahmad P, Khandaker MU, Amin YM, Muhammad N

Sci Rep, 2016;6:21403.
PMID: 26892366 DOI: 10.1038/srep21403

Boron niride microflakes of 2-5 μm in diameter and greater than 40 μm in length with multilayer structure and highly crystalline nature are synthesized in two states of catalysts and dual role of nitrogen at 1100 °C. Most of the microflakes are flat, smooth and vertically aligned with a wall-like view from the top. Transmission electron microscopy shows overlapped layers of microflakes with an interlayer spacing of 0.34 nm. The h-BN components of the synthesized microflakes are verified from B 1s and N1 s peaks at 190. 7 and 397.9 eV. Raman shift at 1370 (cm(-1)) and sharp peaks in the XRD pattern further confirm the h-BN phase and crystalline nature of the synthesized microflakes. Microflakes of h-BN with the above characteristics are highly desirable for the development of a solid state neutron detector with higher detection efficiency.

Matched MeSH terms: Microscopy, Electron, Transmission
Fulltext A tapered aluminium microelectrode array for improvement of dielectrophoresis-based particle manipulation

Buyong MR, Larki F, Faiz MS, Hamzah AA, Yunas J, Majlis BY

Sensors (Basel), 2015;15(5):10973-90.
PMID: 25970255 DOI: 10.3390/s150510973

In this work, the dielectrophoretic force (F(DEP)) response of Aluminium Microelectrode Arrays with tapered profile is investigated through experimental measurements and numerical simulations. A standard CMOS processing technique with a step for the formation of a tapered profile resist is implemented in the fabrication of Tapered Aluminium Microelectrode Arrays (TAMA). The F(DEP) is investigated through analysis of the Clausius-Mossotti factor (CMF) and cross-over frequency (f(xo)). The performance of TAMA with various side wall angles is compared to that of microelectrodes with a straight cut sidewall profile over a wide range of frequencies through FEM numerical simulations. Additionally, electric field measurement (EFM) is performed through scanning probe microscopy (SPM) in order to obtain the region of force focus in both platforms. Results showed that the tapered profile microelectrodes with angles between 60° and 70° produce the highest electric field gradient on the particles. Also, the region of the strongest electric field in TAMA is located at the bottom and top edge of microelectrode while the strongest electric field in microelectrodes with straight cut profile is found at the top corner of the microelectrode. The latter property of microelectrodes improves the probability of capturing/repelling the particles at the microelectrode's side wall.

Matched MeSH terms: Microscopy, Scanning Probe
Fulltext Mechanical Properties of Longitudinal Basalt/Woven-Glass-Fiber-reinforced Unsaturated Polyester-Resin Hybrid Composites

Sapuan SM, Aulia HS, Ilyas RA, Atiqah A, Dele-Afolabi TT, Nurazzi MN, et al.

Polymers (Basel), 2020 Sep 27;12(10).
PMID: 32992450 DOI: 10.3390/polym12102211

This work represents a study to investigate the mechanical properties of longitudinal basalt/woven-glass-fiber-reinforced unsaturated polyester-resin hybrid composites. The hybridization of basalt and glass fiber enhanced the mechanical properties of hybrid composites. The unsaturated polyester resin (UP), basalt (B) and glass fibers (GF) were fabricated using the hand lay-up method in six formulations (UP, GF, B7.5/G22.5, B15/G15, B22.5/G7.5 and B) to produce the composites, respectively. This study showed that the addition of basalt to glass-fiber-reinforced unsaturated polyester resin increased its density, tensile and flexural properties. The tensile strength of the B22.5/G7.5 hybrid composites increased by 213.92 MPa compared to neat UP, which was 8.14 MPa. Scanning electron microscopy analysis was used to observe the fracture mode and fiber pullout of the hybrid composites.

Matched MeSH terms: Microscopy, Electron, Scanning
Studies on Echinostomatidae (Trematoda) in Malaya. XIV. Body gland cells in cercariae of Echinostoma audyi Lie and Umathevy, and E. lindoense Sandground and Bonne

Lie KJ

J Parasitol, 1966 Dec;52(6):1049-51.
PMID: 4162736
Matched MeSH terms: Microscopy
High performance photoanodic catalyst prepared from an active organic photovoltaic cell - high potential gain from visible light

Nagai K, Kuwabara T, Ahmad MF, Nakano M, Karakawa M, Taima T, et al.

Chem Commun (Camb), 2019 Oct 15;55(83):12491-12494.
PMID: 31573004 DOI: 10.1039/c9cc04759j

Photoelectrochemical oxidation of thiols was enhanced with a threshold potential of -0.35 V vs. Ag/AgCl by the use of a ZnPc/PCBM:P3HT/ZnO electode, which was prepared by removing the PEDOT:PSS/Au electrode of an inverted OPV device and coating it with ZnPc. A co-photocatalysis property of ZnPc was observed in the photoelectrochemistry and scanning Kelvin probe microscopy.

Matched MeSH terms: Microscopy
Rapid 'technological lock in' and pathology - Is technology moving too fast?

Moorchung N

Malays J Pathol, 2019 Apr;41(1):1-5.
PMID: 31025631

The term "Lock In" as applied to Science and Technology refers to a technology which has been utilised for a certain amount of time and it has been determined that the technology is viable and cost effective. An analysis of the technological advancements in pathology over a period of time shows that the newer technologies in contrast to the older technologies are reaching a state of "Technological Lock In" much faster. Three different discoveries, the development of the autopsy as a research tool, the discovery of the microscope and immunohistochemistry illustrate how rapidly "Technological Lock In" is being achieved with the passage of time. Three probable scenarios are possible because of this rapid "Technological Lock In". Technology may continue to progress at the same pace (an ideal scenario), may plateau until pathologists accept and absorb new technologies or thirdly, develop very rapidly so that the technology may never reach pathology practice. What will the future be? How will technology influence the principles and practices of Pathology? Only time will tell.

Matched MeSH terms: Microscopy

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links