Milk Films Exposed to High Humidity: Studies with Electron Microscopy and Electrophoresis1,2

1980 ◽  
Vol 43 (1) ◽  
pp. 29-35 ◽  
Author(s):  
R. C. MABESA ◽  
R. T. MARSHALL ◽  
M. E. ANDERSON
Keyword(s):  
Electron Microscopy ◽  
Relative Humidity ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Raw Milk ◽  
Steel Plates ◽  
High Humidity ◽  
Residual Film ◽  
Contact Surfaces ◽  
Scanning Electron

Stainless steel plates, which are similar to milk contact surfaces, were dipped in fresh raw milk. The residual film was dried (37 C and 10% to 20% relative humidity) for 30 min. Treated plates were then exposed to 100% relative humidity for 30 min at 37 C. Scanning electron microscopy revealed splotches of fat on surfaces of dried films and the humidified films had a more aggregated and porous appearance than films that were dried only. The incidence of granulated lactose was greater among humidified samples than among nonhumidified samples. Discontinuous polyacrylamide gel electrophoresis revealed that α- and β-caseins resisted rinsing from plates on which dried films were exposed to 100% relative humidity but not from plates on which films had been dried only.

Effect of detergents and chemicals on purified vaccinia virus: analysis by SDS polyacrylamide gel electrophoresis and electron microscopy

1977 ◽  
Vol 23 (3) ◽  
pp. 240-252 ◽  
Author(s):  
J. Boisvert ◽  
T. Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Vaccinia Virus ◽  
Gel Electrophoresis ◽  
Alkali Treatment ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Ammonium Bromide ◽  
Molecular Weights ◽  
Viral Particles

Vaccinia virus particles were dissociated into their constituent polypeptides and analysed by sodium dodecyl sulfate (SDS) gel electrophoresis. Thirty-three distinct polypeptide bands were identified and their molecular weights ranged between 11 000 and 150 000 daltons.Specific staining of gels containing polypeptides of dissociated virions revealed the presence of eight glycopeptides. No lipopeptides were detected.Analysis of chemical extracts (urea, guanidine hydrochloride, and alkali treatment) of the virus by SDS gel electrophoresis indicated that a total of 10 to 14 different polypeptides ranging in molecular weights from 11 000 to 70 000 daltons were solubilized.Analysis of detergent extracts and of the remains of extracted viral particles has shown that the detergent Nonidet P-40 (NP-40) solubilized a total of 11 polypeptides of which 6 were glycopeptides. The other detergents sodium deoxycholate (SDC) and cetyl trimethyl ammonium bromide (CTAB) were not as selective, both solubilizing more than 25 of the polypeptides composing the virus. Gel electrophoresis results also indicated that most of the small molecular weight (11 000–70 000 daltons) polypeptides were readily solubilized by NP-40, SDC, and CTAB, while those with molecular weights of 70 000 daltons and higher were not well solubilized.The effects of detergents were also analysed by electron microscopy. Evidence was obtained for subpopulations of viral particles having different susceptibility to detergent extraction.

Intracellular fibres in cultured cells: analysis by scanning and transmission electron microscopy and by SDS-polyacrylamide gel electrophoresis

1978 ◽  
Vol 31 (1) ◽  
pp. 369-392
Author(s):  
J.A. Trotter ◽  
B.A. Foerder ◽  
J.M. Keller
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Dimensional Structure ◽  
3T3 Cells ◽  
Transmission Electron ◽  
Ionic Detergent ◽  
Over The Top

The 3-dimensional structure of the fibrous cytoskeleton of 3T3 cells was examined by scanning electron microscopy of cells extracted with the non-ionic detergent Triton X-100. Detergent-extracted cells consist of the nucleus and an extensive system of fibres, the largest of which correspond to stress fibres visible by phase-contrast microscopy. The system of fibres, which is coterminous with the borders of the native cell, remains firmly adherent to the substratum. The major fibres branch into smaller fibrils which appear to end by ravelling out into fine filaments that constitute a matted network in a plane very close to that of the substratum. In the nuclear region all the major fibres pass over the top of the nucleus, where they may also branch into a system of fine fibrils. Thin-section transmission electron microscopy in conjunction with heavy meromyosin treatment of extracted cells shows the fibres to be composed of native F-actin. Intermediate filaments are also present, and are prominent in the matted network, together with actin filaments. The major proteins of the residue are identified by SDS-polyacrylamide gel electrophoresis as actin, a 56000 Dalton peptide, and histones. Also present are myosin heavy chain, peptides of 225,000 and 250,000, and minor bands at 60,000 and 94,000 Daltons. The non-ionic detergent extracts 70% of the cellular protein, including 50% of the actin and 75% of the myosin. The Triton-insoluble fraction of 3T3 cells appears to constitute, in addition to the nucleus, a stable cytoskeletal system, composed largely of contractile proteins and 10-nm filaments, which functions in maintenance of cell shape, in substratum adhesion, and in positioning the nucleus within the cell.

scholarly journals Characterization of Brass/Steel Plates Joined by Friction Stir Welding

2018 ◽  
Vol 7 (3.34) ◽  
pp. 366
Author(s):  
Mariyappan. K ◽  
Praveen K ◽  
Suresh Kumar.S ◽  
Kadambanathan. K ◽  
Rajamanickam. S ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Weld Zone ◽  
Steel Plates ◽  
Micro Hardness ◽  
Friction Stir ◽  
Fsw Parameters ◽  
Scanning Electron

The aim of this study is to show the feasibility for butt joining dissimilar brass to austenitic stainless steel plates by Friction Stir Welding. In this study, the limited FSW parameters were employed. Metallurgical characterization like Scanning Electron Microscopy and Mechanical characterization like tensile test, Micro hardness is done to investigate the joint performance and the weld zone of dissimilar brass/steel joints. The tensile strength and micro hardness values are 20 MPa, 122 MPa and 157 MPa and 175 Hv, 196 Hv and 199 Hv for the table traverse speeds of 40 mm/min, 50 mm/min and 60 mm/min respectively. The tensile strength of dissimilar brass/steel joint was found to be lower than that of parent metals. The defect free brass/steel interfaces were seen by Scanning Electron Microscopy. It was illustrated that the stirred zone exposed to two main structures namely, recrystallized grains of brass and intercalated swirl and vortex-like structure which can be characterized both the recrystallized brass grains and steel layers. This work is one of the preliminary studies on the detailed examinations of the dissimilar brass/steel joined by Friction stir welding. 

scholarly journals Subaxolemmal filamentous network in the giant nerve fiber of the squid (Loligo pealei L.) and its possible role in excitability.

1978 ◽  
Vol 78 (2) ◽  
pp. 597-621 ◽  
Author(s):  
J Metuzals ◽  
I Tasaki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nerve Fiber ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Three Dimensional ◽  
Polarized Light ◽  
Thin Sections ◽  
Loligo Pealei ◽  
Scanning Electron

A new technique utilizing the squid giant nerve fiber has been developed which permits direct examination of the inner face of the axolemma by scanning electron microscopy. The axoplasm was removed sequentially in a 15-mm long segment of the fiber by intracellular perfusion with a solution of KF, KCl, Ca++-containing seawater, or with pronase. The action potential of the fibers was monitored during these treatments. After brief prefixation in 1% paraformaldehyde and 1% glutaraldehyde, the perfused segment was opened by a lne could be related to information on the detailed morphology of the cytoplasmic face of the axolemma and the ectoplasm. The results obtained by scanning electron microscopy were further substantiated by transmission electron microscopy of thin sections. In addition, living axons were studied with polarized light during axoplasm removal, and the identification of actin by heavy meromyosin labeling and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis was accomplished. These observations demonstrate that a three-dimensional network of interwoven filaments, consisting partly of an actinlike protein, is firmly attached to the axolemma. The axoplasmic face of fibers in which the filaments have been removed partially after perfusion with pronase displays smooth membranous blebs and large profiles which sppose the axolemma. In fibers where the excitability has been suppressed by pronase perfusion, approximately one-third of the inner face of the axolemma in the perfusion zone is free of filaments. It is hypothesized that the attachment of axoplasm filaments to the axolemma may have a role in the maintenance of the normal morphology of the axolemma, and, thus, in some aspect of excitability.

Identification and Analytical Examination of Copper Alloy Pigments Applied as Golden Illuminations on Three Persian Manuscripts

2015 ◽  
Vol 36 (2) ◽  
Author(s):  
Sayed Mohammadjavad Mousavi ◽  
Hossein Ahmadi ◽  
Abbas Abed-Esfahani ◽  
Mohammad Mortazavi ◽  
Maurizio Aceto
Keyword(s):  
Electron Microscopy ◽  
Copper Alloy ◽  
Energy Dispersive Spectrometry ◽  
Degradation Products ◽  
Illuminated Manuscripts ◽  
Ternary Alloys ◽  
Historical Documents ◽  
High Humidity ◽  
Copper Zinc ◽  
Scanning Electron

AbstractGolden pigments are among the most common colourants used in Persian illuminated manuscripts. In this research, golden pigments were investigated in three eighteenth- to nineteenth-century manuscripts. Initially, scanning electron microscopy–energy dispersive spectrometry analyses showed that different kinds of metallic pigments were present and some of them were ternary alloys made up of copper, zinc and tin, hence copper-based alloys were ascertained as cheap alternatives to gold. Discolouration of the pigment was observable through alteration of the metallic pigments to greenish residues in the manuscripts. Subsequently, the greenish products in the golden pigments were studied by Raman spectroscopy. Copper carboxylates were recognized as degradation products. We inferred that the alteration is a consequence of the interaction between copper alloy pigments and carboxylic acids in conditions of high humidity. Moreover, more progressive degradation has caused the discolouration, brittleness and gradually crumbling of the paper in the painted areas. Signs of damages in the paper were comparable with decomposition of the paper by green copper pigments such as verdigris in historical documents and miniatures.

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