Life Sciences Commons^™

Scanning Electron Microscopic Studies Of The Palatine Mucosa And Its Microvascular Architecture In The Rat, S. Sugioka, H. Ike

Scanning Microscopy

Detailed observations were made on the structure and microvasculature of the palatine mucosa of the rat by means of microvascular corrosion casts and epithelium-digested specimens using scanning electron microscopy. The rat palate was divided into four regions according to the characteristics of the palatine plicae. In the atrial region, no transverse palatine plicae were present, but there were longitudinal ridges and folds in the median area. These structures contribute to the transportation of rough and grainy foods with the assistance of the hairy buccal part. Capillary loops in the ridge and folds appeared as continuous, sagittally elongated loops. In the …

Humidity Effects On Atomic Force Microscopy Of Gold-Labeled Dna On Mica, J. Vesenka, S. Manne, G. Yang, C. J. Bustamante, E. Henderson

Scanning Microscopy

Recent work in atomic force microscopy (AFM) of deoxyribonucleic acid (DNA) has relied on immobilizing DNA molecules by drying a small volume of buffered DNA solution onto cleaved mica. When imaging in air, relative humidity has been known to affect both the resolution and measured height of the DNA strands. We present data of measured height versus humidity for DNA and attached gold labels, and we propose a model for this data based on swelling of coadsorbed buffer salts upon exposure to moisture. In this model, small particles (e.g., DNA) stay near the top of the swelling salt layer, whereas …

Louisiana Agriculture Magazine, Fall 1993, Lsu Agricultural Experiment Station

Louisiana Agriculture

No abstract provided.

A Simple Empirical Calibration Of Energy Dispersive X-Ray Analysis (Edxa) On The Cornea, N. F. Schrage, K. Benz, P. Beaujean, W. -G. Burchard, M. Reim

Scanning Microscopy

Monitoring of the corneal electrolyte content is important for the study of chemical eye burns. This paper describes quantitative measurements on gelatin standards, corneas and a cornea homogenate with an energy dispersive X-ray analyzer (EDX) in the scanning electron microscope (SEM). Ten micrometers thick cryosections were freeze-dried and mounted on solid carbon supports. The applied quantification procedure was a local peak background analysis with a specifically designed computer program. Similar chemical and physical properties of gelatin, cornea homogenate, and cornea were proven by EDX-analysis and wet chemical analysis. Gelatin standards with known concentrations of different added salts showed linear correlations …

Mechanisms Of Cavity Growth During Ion Implantation, J. H. Evans

Scanning Microscopy

This paper will review two separate areas of cavity growth under ion implantation, firstly bias-driven void growth occurring in metals over the range 0.3 to 0.5 of the melting point at high displacement doses, and secondly, bubble growth during inert gas implantation. Interesting phenomena take place in both areas, e.g. void swelling and void lattice formation in the first and blistering, bubble lattices and the precipitation of heavier inert gases in the solid phase in the second. These phenomena will be described together with the extension of mechanisms to other implant species such as carbon where the possibility of precipitation …

X-Ray Microanalysis Of Chief Cells In Rat Parathyroid Gland, Romuald Wroblewski

Scanning Microscopy

X-ray microanalysis was used to study the elemental composition of the rat parathyroid gland. Analyses were performed in morphologically defined cells. Use of semi-thin cryosections allowed us to selectively analyze cell nucleus, cytoplasm and occasionally dense granules in the cytoplasm.

The concentration of elements (mmol/kg dry weight) in chief cells of parathyroid gland were as follows: Na 83, Mg 48, P 853, S 224, Cl 164, K 551 and Ca 10. Significantly higher phosphorus and potassium concentrations were found in the dense granules as compared to cytoplasm of the parathyroid chief cells. Choosing rat parathyroid gland gave the possibility to …

Rabbit And Human Non-Keratinising Stratified Squamous Oesophageal Epithelium Displays Similar Microridge Structure By Scanning Electron Microscopy, S. Shasha'a, G. R. Dickson, R. St. C. Gilmore, G. C. Crean, M. M. Butt, K. E. Carr

Scanning Microscopy

Since the oesophageal epithelium of common laboratory animals, rats and mice, is keratinized it is unsuitable for comparison with typical non-keratinized stratified squamous human epithelium. It is thus important to find a suitable animal model for the study of human oesophageal tissue changes. This study investigated the microridge structure of immature and adult rabbit specimens, and adult human biopsies by scanning electron microscopy and morphometry. The investigation revealed a similarity between typical squamous human and adult rabbit oesophageal mucosal epithelium. While human epithelium specimens subdivided into two other groups (non-typical squamous and non-squamous); all typical squamous human biopsies were from …

Local Susceptibility Against Soft Errors In Dynamic Random Access Memories (Drams) Analyzed By Nuclear Microprobes, H. Sayama, M. Takai, H. Kimura, Y. Ohno, S. Satoh

Scanning Microscopy

A novel evaluation technique for soft errors in Mbit DRAMs (dynamic random access memories) has been developed using a 400 keV proton microprobe system. This technique, which is called soft error mapping, consists of a bit-state mapping image and a secondary electron mapping image, and can reveal the correlation between the incident position of protons and susceptibility against soft errors in DRAMs. Soft errors are found to be induced by proton incidence at 400 keV within about 6 μm around the memory cell in the case of DRAMs with a conventional well. The susceptible area against proton incidence is much …

Contributions Of Electron Microscopy To The Study Of The Hypertrophic Scar And Related Lesions, C. Ward Kischer

Scanning Microscopy

Prior to 1969, only one study of the hypertrophic scar had been done using electron microscopy, and that one used electron diffraction. Since that time, studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been integral in establishing not only the characteristics of this lesion but in formulating the reasons why the scar develops and how it resolves. The first SEM studies demonstrated a homogeneous, dense dermal matrix which supported the conclusion that the hypertrophic scar and keloid reflected excess collagen. These same studies were integral in identifying the collagen nodule as the basic anatomical unit of …

Observations On The Enamel Of Odontomas, Carla Marchetti, Cesare Piacentini, Paolo Menghini, Marcella Reguzzoni

Scanning Microscopy

The morphological study of odontomas provides an alternative model for observing the formation of dental tissues, since different maturing stages are present simultaneously. Investigations were performed on decalcified samples (using light microscopy and transmission electron microscopy) and on undecalcified samples of complex odontoma enamel (using transmission electron microscopy). Simultaneous presence of prismatic enamel at various maturing stages with different structural characteristics was observed. Such enamel was sometimes associated with layers of ameloblastic cells with characteristics of cells in functional activity. In other sites, the enamel did not present a prismatic structure but it appeared as unstructured material clusters with abundant …

Ascorbic Acid Is An Abettor In Calcium Urolithiasis: An Experimental Study, P. P. Singh, R. Kiran, A. K. Pendse, Reeta Ghosh, S. S. Surana

Scanning Microscopy

Two sets of animal experiments using guinea pigs were planned to evaluate the effect of ascorbic acid supplementation on the lithogenic process. In the first set of experiments, 10, 40, and 60 mg doses of ascorbic acid/100g body weight/day were given for 105 days. Neither of the ascorbic acid doses given induced crystalluria, calcification or stone formation, thereby confirming our previous findings that ascorbic acid in the doses used by clinicians does not cause urolith formation. In the second set of experiments, ascorbic acid was supplemented in hypercalciuric (induced by calcium carbonate feeding) and hyperoxaluric (induced by sodium oxalate feeding) …

A Simulation Model For Electron Irradiation Induced Specimen Charging In A Scanning Electron Microscope, D. S. H. Chan, K. S. Sim, J. C. H. Phang

Scanning Microscopy

A numerical model has been formulated to simulate the dynamics of specimen charging in a scanning electron microscope. In this model, the electric field due to imposed boundary conditions and fixed charges is solved by the finite element method. The empirical electron yield data are stored in "Universal Yield Curves (UYC)". These UYCs control the generation of secondary and backscattered electrons from various materials. The electrons emitted from electron-solid interactions are tracked using a leapfrog integration scheme. Excess charges generated on the surface of electrically floating solids are assigned to numerical grids using a linear charge redistribution scheme. The validity …

Author Index To Volume Four, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Index by author to all articles published in Volume Four (1993) of the journal RISK: Issues in Health and Safety.

Loved--Or Lost?

Close Up Reports

No abstract provided.

Daubert's Significance, Thomas G. Field Jr., Colleen M. Keegan

RISK: Health, Safety & Environment (1990-2002)

The authors review and note the limited reach of Daubert v. Merrell Dow Pharmaceuticals. They also address its implications for concerned non-lawyers.

Regulate Pollution Or Land Use - Managing Toxic Air Contaminants In Southern California, Marc Dohan

RISK: Health, Safety & Environment (1990-2002)

A California air quality management district recently proposed to limit the location of potential receivers, in contrast with sources, of air toxics. The author argues that, although this particular proposal was later abandoned, it amounted to land use regulation. He also argues that such action usurps local control and is unwarranted.

Title Index To Volume Four, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Title index to all articles published in Volume Four (1993) of the journal RISK: Issues in Health and Safety.

Index Of Book Reviews For Volume Four, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Index to book reviews published in Volume Four (1993) of the journal RISK: Issues in Health and Safety.

Table Of Contents, Volume Four, Number Four, Fall 1993, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Issues in Health & Safety (ISSN: 1073-8673).

Scanning Electron Microscopy Of Human Esophageal Mucosa In Patients With Carcinoma Of The Esophagus, M. Cwikiel, M. Q. Yang, M. Albertsson, C. -H. Håkansson, M. Palmegren

Scanning Microscopy

Specimens taken at surgery from 15 patients with carcinoma of the esophagus were examined with scanning electron microscopy. Nine patients were treated with chemotherapy (cisplatin + 5-fluorouracil), surgery and radiotherapy; one received preoperative radiotherapy only; and the remaining five primary surgery only. Scanning electron microscopy was performed on specimens of both tumor tissue and the mucosa at least 5 cm from the tumor. In adjacent non-tumor tissue, damage due to treatment was observed in the form of changes in microridges and increased cell loss. In tumor tissue, the degree of damage was correlated to tumor response to treatment. For patients …

A Combined Near Field Optical And Force Microscope, M. H. P. Moers, R. G. Tack, N. F. Van Hulst, B. Bölger

Scanning Microscopy

Scanning near field optical microscopy (SNOM) is the optical alternative of the scanning probe microscopical techniques which enables a lateral resolution down to about 10 nm, unlimited by diffraction. Moreover, the potential of non-destructive imaging of chemical and biological samples with nanometer resolution in ambient conditions is a crucial advantage over electron microscopy.

An integrated microscope has been constructed which allows simultaneous detection of optical and force interaction between a microfabricated SiN probe and a sample surface. Images are obtained in a transmission mode by detection of the light emanating from a "supertip" in contact with the sample surface and …

Nuclear Microprobe For Integrated Circuit Process Inspection, Mikio Takai, Ryoh Mimura, Hiroshi Sawaragi, Ryuso Aihara

Scanning Microscopy

A nuclear microprobe with a minimum beam-spot diameter of less than 100 nm, intended for application to IC (integrated circuit) process inspection, has been designed and installed at Osaka University. An ultra high-vacuum sample-chamber with a three-axis goniometer stage and a toroidal electrostatic analyzer for medium energy ion scattering (MEIS) was combined with a short acceleration column for a focused ion beam. A liquid metal ion source (LMIS) for light metal ions such as Li⁺ or Be⁺ was mounted on the short column. A minimum beam spot-size of about 80 nm with a current of 30 pA was …

Characterization Of The Complex Sulfide Ore Of Sotiel (Spain) By Scanning Electron Microscopy And Electron Microprobe Analysis, Giuseppe Bonifazi, Roberto Gorga

Scanning Microscopy

This study complements a more exhaustive examination on the complex sulfide mineralization of Sotiel, (Spain), by optical microscopy and multispectral digital analysis of images. Electron microscopy analyses were carried out to document specific associations which are difficult to detect with conventional optical microscopy. This study utilizes the application of digital techniques to image processing, in an attempt to define microstructural and microtextural characteristics of the ore, since they play an important role in the subsequent beneficiation operations (i.e., flotation).

Scientific and economic information bound to complex metallogenic phenomenology and referred to particular paragenetic scenes was acquired by the study in …

Nanometer-Scale Synthesis And Atomic-Scale Modification With The Scanning Tunneling Microscope, Reginald M. Penner

Scanning Microscopy

The structure or composition of a surface may be locally altered in either of two fundamental ways using the scanning tunneling microscope (STM). A modification of the surface may be induced resulting in the rearrangement and/or removal of surface atoms, or in the transfer of atoms from the tip to the sample surface. In many recent experiments, the modification of surfaces has involved a single atom or an ensemble of a few atoms. Alternatively, the localized synthesis of a new material from reactants external to the STM tip and sample can be induced using at least three experimental strategies. A …

Scanning Electron Microscopic Examination Of Intracanal Wall Dentin: Hand Versus Laser Treatment, H. E. Goodis, J. M. White, S. J. Marshall, G. W. Marshall Jr.

Scanning Microscopy

Conventional cleaning and shaping of root canal spaces involves the use of hand and rotary instruments with irrigation. The procedure results in the formation of a smear layer consisting of dentin shavings, organic tissue remnants and microorganisms. The laser has been suggested as an aid in root canal preparation. In this study, pulsed and continuous wave 1.06 μm wavelength Nd:YAG lasers were used to compare their abilities to clean and shape root canal spaces to conventional methods. After preparation, the test teeth were sectioned longitudinally and examined by scanning electron microscopy. The results demonstrated that the laser was capable of …

The Present Status Of Cathodoluminescence Attachments For Optical Microscopes, Donald J. Marshall

Scanning Microscopy

The serious use of cathodoluminescence (CL) in petrography began about 30 years ago with the electron microprobe analyzer. Investigators soon began to use simpler instruments mounted directly on optical microscopes - cathodoluminescence microscope attachments (CMAs).

A major advantage of the CMA, compared to a scanning electron microscope (SEM) or electron microprobe analyzer (EMPA), is the capability to switch quickly between CL observations and high quality conventional optical microscope observations. Beam currents available in the CMA are higher than in the SEM or EMPA and one sees an instantaneous real time true color display of the CL pattern.

CMAs are based …

Morphological Characterization Of The Radiation Sensitive Cell Line, Xrs-5, Carol C. Korte, Linda S. Yasui

Scanning Microscopy

Morphometric analysis was performed on the radiation sensitive Chinese hamster ovary (CHO) xrs-5 cell line, reverting xrs-5 cells and parental K1 cells. Several ultrastructural parameters (increased nuclear envelope membrane separation, cell and nuclear volume, nuclear to cytoplasmic ratio, and the nuclear surface area per unit volume of the cell) were measured and correlated with radiation sensitivity. A trend in increased cell size and radiosensitivity was observed. However, only the substantially increased nuclear envelope membrane separation in sensitive xrs-5 cells significantly correlated with radiation sensitivity. The maximal nuclear envelope membrane separation in sensitive xrs-5 cells was 270.8 nm. The maximal K1 …

New Methods For Depositing And Imaging Molecules In Scanning Tunneling Microscopy, Victor N. Morozov, Nadrian C. Seeman, Neville R. Kallenbach

Scanning Microscopy

Methods and apparatus are described to deposit and image molecules by scanning tunneling microscopy (STM) under an inert atmosphere. Three methods of applying molecules have been evaluated: equilibrium adsorption from the vapor phase, sublimation, and electrospraying. Using these methods, a variety of organic and biopolymer molecules have been deposited and imaged on graphite and on gold (111), grown epitaxially on mica. Compared with alternatives, such as the use of high vacuum apparatus or glove boxes, these procedures offer some important advantages: they are inexpensive, convenient, and more rapid. Mercaptoethanol, ethanolamine, ethanol, acetic acid, and water produce two-dimensional crystalline adlayers on …

The Interaction Between Nephrocalcin And Tamm-Horsfall Proteins With Calcium Oxalate Dihydrate, Sergio Deganello

Scanning Microscopy

Studies of crystals of calcium oxalate dihydrate (COD) grown by vapor diffusion from solutions contain-ing 5.1 x 10^-7, 1.5 x 10^-6, and 1.0 x 10^-5 M nephrocalcin (NC), indicate that NC profoundly affects COD's habit, size and structure. The decrease in COD size is such that at 1.0 x 10^-5 M NC, the dimensions of the crystals are reduced about five-fold with respect to those of a NC-free control. In addition, the planes of the {101} form disappear, the original habit is lost, and the diffraction pattern deteriorates to such an extent that only …

Three-Dimensional Cytoskeletal Structures Of The Chinchilla Organ Of Corti: Scanning Electron Microscopy Application Of The Polyethylene Glycol Method, A. Nagasawa, R. V. Harrison, R. J. Mount, Y. Harada

Scanning Microscopy

We describe the application of a polyethylene glycol (PEG) embedding technique to examine the sensory and supporting structures of the inner ear. The chinchilla organ of Corti was exposed by cracking PEG embedded cochleas. A range of PEG molecular weights (2000-8000) were utilized; PEG 2000, with a melting point of 57°C was preferred. After removal of the PEG, the three-dimensional aspects of intracellular structures were observed using scanning electron microscopy. Filamentous elements in the hair cell cuticular plate and in the supporting cells were clearly observed, as was the mesh work of cross-linked actin filaments in the cuticular portion of …