scholarly journals Aggregation of membrane-associated actin filaments following localized adherence of enteropathogenic Escherichia coli to HeLa cells

1989 ◽  
Vol 93 (3) ◽  
pp. 439-446
Author(s):  
M.L. da Silva ◽  
R.A. Mortara ◽  
H.C. Barros ◽  
W. de Souza ◽  
L.R. Trabulsi
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Scanning Electron Microscopy ◽  
Hela Cells ◽  
Low Temperatures ◽  
Actin Filaments ◽  
Cytochalasin D ◽  
Enteropathogenic Escherichia Coli ◽  
Microfilament System ◽  
Scanning Electron

We have previously observed that enteropathogenic Escherichia coli (EPEC) adhere to HeLa cells in a localized manner, which we designated localized adherence as opposed to the diffuse pattern of adhesion. In this paper we have examined the effects of localized adherence of EPEC on the actin microfilament system of host HeLa cells. Centrifugation of bacteria onto HeLa cells improved the localized adherence and rapid rearrangements of actin filaments were detected by immunofluorescence and electron microscopy. Aggregation of microfilaments is consistently observed at the sites of localized adherence, and is abolished by cytochalasin D and low temperatures. Scanning electron microscopy indicates that these aggregates are surface microvilli entangled with attached EPEC.

Ultrastructure of the soil fungus, Geomyces pannorus

1984 ◽  
Vol 42 ◽  
pp. 738-739
Author(s):  
J. A. Traquair ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
Low Temperatures ◽  
Soil Fungus ◽  
Organic Soils ◽  
Anatomical Studies ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Scanning Electron

With the advent of improved dehydration techniques, scanning electron microscopy has become routine in anatomical studies of fungi. Fine structure of hyphae and spore surfaces has been illustrated for many hyphomycetes, and yet, the ultrastructure of the ubiquitous soil fungus, Geomyces pannorus (Link) Sigler & Carmichael has been neglected. This presentation shows that scanning and transmission electron microscopical data must be correlated in resolving septal structure and conidial release in G. pannorus.Although it is reported to be cellulolytic but not keratinolytic, G. pannorus is found on human skin, animals, birds, mushrooms, dung, roots, and frozen meat in addition to various organic soils. In fact, it readily adapts to growth at low temperatures.

scholarly journals SINTESIS NANOKOMPOSIT Nata de coco/TiO2/Ag DAN EFEKTIVITASNYA SEBAGAI ANTIBAKTERI TERHADAP BAKTERI Escherichia coli dan Staphylococcus aureus

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Heriyanto Tinentang ◽  
Henry F Aritonang ◽  
Harry S. J. Koleangan
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Chemical Reduction ◽  
Bacterial Activity ◽  
Energy Dispersive ◽  
X Ray ◽  
Escherichia Coli Bacteria ◽  
Scanning Electron

Telah dilakukan penelitian tentang kemampuan aktivitas anti bakteri untuk bakteri Staphylococcus aureus (gram positif) dan Escherichia coli (gram negatif) dengan menggunakan nanokomposit nata de coco/TiO2, nata de coco/Ag, dan nata de coco/TiO2/Ag dengan variasi konsentrasi Ag 0,5 M; 0,6 M; 0,7 M; 0,8 M dan 0,9 M  menggunakan metode reduksi kimia. Nanopartikel tersebut dikarakterisasi menggunakan X-Ray Diffractometry (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy  (SEM-EDS) dan anti bakteri. Untuk uji aktivitas antibakteri menggunakan metode kertas cakram dan dilakukan sebanyak dua kali ulangan untuk tiap-tiap sampel dan bakteri yang diuji. Hasil penelitian menunjukan, aktivitas anti bakteri nanokomposit yang paling baik dalam menghambat pertumbuhan bakteri adalah nanokomposit Nata de coco/TiO2/Ag mampu menghambat pertumbuhan bakteri Escherichiacoli dan Staphylococcusaureus, namun nanokomposit tersebut lebih efektif menghambat pertumbuhan bakteri Escherichiacoli.ABSRACT Research on the ability of anti-bacterial activity for Staphylococcus aureus (gram positive) and Escherichia coli (gram negative) bacteria using nata de coco / nanocomposites TiO2, nata de coco / Ag, and nata de coco / TiO2 / Ag with variations of Ag 0,5 M; 0.6 M; 0.7 M; 0.8 M and 0.9 M using the chemical reduction method. Nanoparticles were characterized using X-Ray Diffractometry (XRD), scanning electron microscopy-energy dispersive X-ray spctroscopy  (SEM-EDS) and anti-bacterial actvity. Test the antibacterial activity using the paper disc method and repeated two times for each sample and bacteria tested. The results showed that the good anti-bacterial activity of nanocomposites in inhibiting bacterial growth was nanocomposite nata de coco /TiO2/Ag  able to inhibit the growth of Escherichia coli and S. aureus, but the nanocomposite is more effective in inhibiting the growth of Escherichia  coli bacteria.

scholarly journals N-halamine antibacterial nanofibrous mats based on polyacrylonitrile and N-halamine for protective face masks

2019 ◽  
Vol 14 ◽  
pp. 155892501984322 ◽  
Author(s):  
Chengbo Huang ◽  
Ying Liu ◽  
Zhiguang Li ◽  
Rong Li ◽  
Xuehong Ren ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Scanning Electron Microscopy ◽  
Air Permeability ◽  
Escherichia Coli O157 ◽  
Electrospinning Technique ◽  
Antibacterial Materials ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Biocidal Properties ◽  
Scanning Electron

The main objective of this study was to develop antibacterial materials based on polyacrylonitrile for potential application in protective face masks to combat airborne pathogens. To achieve biocidal properties, 1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone as a kind of N-halamine was introduced into the polyacrylonitrile nanofibers by an electrospinning technique to form nanofibers by an electrospinning technique to form polyacrylonitrile/1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone-5% nanofibers. Scanning electron microscopy and Fourier transformed infrared spectroscopy were employed to characterize the structure of nanofibers. The antimicrobial efficacies of electrospinning nanofibers with 1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone against both Staphylococcus aureus and Escherichia coli O157:H7 were evaluated at different contact times. The antimicrobial efficacies against bioaerosol of S. aureus were also performed. The polyacrylonitrile/1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone-5% nanofibers possess excellent antimicrobial efficacies against bacteria bioaersol, and it has good air permeability.

scholarly journals High resolution scanning electron microscopy of isolated and in situ cytoskeletal elements.

1979 ◽  
Vol 83 (1) ◽  
pp. 249-254 ◽  
Author(s):  
W Ip ◽  
D A Fischman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Intermediate Filaments ◽  
Actin Filaments ◽  
Critical Point Drying ◽  
Osmium Impregnation ◽  
Cytoskeletal Elements ◽  
Scanning Electron

Evidence is presented that cytoskeletal structures (actin filaments, intermediate filaments, and microtubules) can be resolved by scanning electron microscopy after osmium impregnation of biological material, using thiocarbohydrazide as a ligand, followed by critical-point drying. These different classes of filaments or tubules can be identified both as purified protein polymers and as structured organelles within cryofractured or detergent-extracted cells.

scholarly journals Sintesis Nanopartikel ZnO dan Aplikasinya sebagai Edible Coating Berbasis Pektin untuk Memperpanjang Umur Simpan Buah Belimbing

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Muhammad Fajri Romadhan ◽  
Shanti Pujilestari
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Edible Coating ◽  
Plate Count ◽  
Total Plate Count ◽  
Particle Size Analyzer ◽  
Infra Red ◽  
Scanning Electron

ABSTRAKNanopartikel ZnO (NP-ZnO) merupakan partikel yang mempunyai aktivitas antimikroba cukup luas yaitu dapat menghambat pertumbuhan bakteri Gram negatif, Gram positif, khamir dan kapang. Nanopartikel ZnO dapat digunakan sebagai bahan tambahan untuk memperbaiki sifat mekanik dan fungsional dari edible coating yang berbasis pektin. Tujuan dari penelitian ini adalah untuk melihat pengaruh edible coating pektin+NP-ZnO terhadap masa simpan buah belimbing. Nanopartikel disintesis dengan metode presipitasi menggunakan tiga suhu pemanasan yang berbeda yaitu 60, 80 dan 100°C selama 2 jam dan ditanur pada suhu 500°C selama 5 jam. Nanopartikel yang terbentuk dikarakterisasi menggunakan Fourier Transform Infra Red (FTIR), Particle Size  Analyzer (PSA) dan Scanning Electron Microscopy (SEM). Hasil analisis FTIR menunjukkan bahwa nanopartikel ZnO telah terbentuk dengan adanya puncak pada panjang gelombang 474 cm-1. Suhu sintesis nanopartikel ZnO terbaik adalah 800C dengan ukuran partikel rata-rata 43.1 nm. Hasil analisis SEM memperlihatkan bahwa nanopartikel yang terbentuk mempunyai morfologi bulat. Hasil uji antimikroba dengan metode Total Plate Count (TPC) memperlihatkan nanopartikel ZnO dapat menghambat pertumbuhan bakteri Bacillus cereus, Escherichia Coli dan kapang Penicillium Sp. Aplikasi edible coating pektin+ Nanopartikel ZnO 1% pada buah belimbing memperlihatkan penurunan susut bobot,  menjaga warna buah lebih stabil dan mencegah kerusakan buah yang ditimbulkan kapang selama delapan hari penyimpanan. Kata kunci: nanopartikel ZnO, edible coating, antimikroba, umur simpan, belimbing

Microstructures of Oxidized Si3N4-8%Y2O3

1982 ◽  
Vol 40 ◽  
pp. 558-559
Author(s):  
K. Kuroda ◽  
H. C. Liu ◽  
A. H. Heuer ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperatures ◽  
Ambient Air ◽  
X Ray ◽  
Passive Oxidation ◽  
Transmission Electron ◽  
Doped Silicon ◽  
Apparent Stability ◽  
Scanning Electron

Introduction. There is considerable interest in the effect of oxidation on the microstructure of yttria-doped silicon nitride, since some compositions are unstable at low temperatures (=1000°C) despite their apparent stability at 1400°C (1). The material used in this study was the same commercial hotpressed Si3N4-8%Y2O3 (NCX-34) as one investigated previously, which had exhibited only passive oxidation during heating in air from 600° to 1400°C. Some thin (=100μm) specimens were oxidized at 800°, 1000° and 1450°C in ambient air and then ion-thinned from one side; others were ion-milled and oxidized. Specimens were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) along with energy dispersive x-ray (EDX) analysis.

Sign in / Sign up

Export Citation Format

Share Document