Specular Surface Stereo: A New Method For Retrieving the Shape of a Water Surface

To learn about the ultrastructural similarities and dissimilarities between the Alzheimer's paired helical filaments (PHF) and normal neurofilaments, we developed a new method to cut the plastic embedded block. We call the sections cut by this new method supra-ultrathin sections. To obtain supra-ultrathin EM sections, a selected area of the tissue block was first trimmed to a size about 0.25 mm2 to reduce the sectioning pressure between the knife and the tissue block. The tissue was sectioned as thin as possible. The interference color of the sections was almost as transparent as the water surface. The thicker sections with different interference colors were removed by picking up with hair tip so that all of the sections floating on the water were of same or similar thickness. A saturated solution of uranyl acetate in 50% ethanol was used to maximize the contrast of these supra-ultrathin EM sections on uncoated grids.

Download Full-text

A simple new method for the determination of ammonium isotopes by gas chromatography-mass spectrometry

Analytical Methods ◽

10.1039/d1ay00456e ◽

2021 ◽

Author(s):

Wei Guo ◽

Ran Jiang ◽

Xinfeng Zhang ◽

Jun Li

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Drinking Water ◽

Surface Water ◽

Water Samples ◽

Water Surface ◽

15N Natural Abundance ◽

New Method ◽

Gas Chromatography Mass Spectrometry

We report a new method for the determination of 15N natural abundance (concentration of 15N) for ammonium (NH4+) in the water samples, including drinking water, surface water, groundwater, and seawater,...

Download Full-text

Water used to visualize and remove hidden foreign bodies from the external ear canal

The Journal of Laryngology & Otology ◽

10.1017/s0022215100118948 ◽

1992 ◽

Vol 106 (2) ◽

pp. 157-158 ◽

Cited By ~ 5

Author(s):

Timo Johannes Peltola ◽

Rainer Saarento

Keyword(s):

Tympanic Membrane ◽

Water Level ◽

Water Surface ◽

Foreign Bodies ◽

New Method ◽

External Ear ◽

Ear Canal ◽

Epithelial Migration ◽

External Ear Canal ◽

Concave Lens

AbstractSmall foreign bodies lodged anteriorly in the tympanic sulcus are usually not visible, due to the curve of the external ear canal. Such objects can be seen with the aid of an otomicroscope and micromirror or with an endoscope, and removed by irrigation. If irrigation fails, epithelial migration on the tympanic membrane may remove lodged foreign bodies, although this may take months. Our new method, which uses water to locate small objects lodged in the tympanic sulcus, includes irrigation of the ear, adjustment of the water level to the middle curve of the external ear canal, and use of the water surface as a concave lens, making the tympanic sulcus visible. With otomicroscopy a curved ear probe can then be used to remove lodged foreign bodies from behind the curve.

Download Full-text

Immunoferritin localization of intracellular antigens in positively stained frozen sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008170x ◽

1978 ◽

Vol 36 (2) ◽

pp. 168-169

Author(s):

K. T. Tokuyasu

Keyword(s):

Surface Tension ◽

Water Surface ◽

Thin Layers ◽

The Other ◽

Positive Staining ◽

Frozen Sections ◽

The Past ◽

Ultrathin Frozen Sections ◽

Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Download Full-text

Selective Sampling and Orientation of Non-Homogeneous Tissues

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100238 ◽

1968 ◽

Vol 26 ◽

pp. 98-99

Author(s):

C. C. Clawson ◽

L. W. Anderson ◽

R. A. Good

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Light Microscopy ◽

Random Sampling ◽

New Method ◽

Microscope Examination ◽

Small Areas ◽

Selective Sampling ◽

Large Numbers ◽

Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Download Full-text