Digital Commons Network^™

Effects Of Photosensitization And Low-Power Helium-Neon Laser Irradiation On Liposomes And Cell Membranes, Timea Berki, P. Németh, L. Pótó, A. Németh

Scanning Microscopy

Low-power He-Ne laser irradiation causes a well-defined and energy dependent cell destruction of in vitro cultured cell lines sensitized by hematoporphyrin derivative (HPD). The mechanism of this photosensitization was studied by measuring with polarization microscopic, scanning electron microscopic, and electron-spin-resonance (ESR) spectroscopic parameters. The cell damage caused by photosensitization and laser irradiation seems to be a complex process, however the biological membranes seem to be one of the primary targets. The energy of laser light causes rotation and resonance changes of macromolecules and the water molecules, resulting in an increased structural order of the submembraneous components in the living cells, …

The Scanning Electron Microscope: How Valuable In The Evaluation Of Small Bowel Mucosal Pathology In Chronic Childhood Diarrhea?, J. Rainer Poley

Scanning Microscopy

Data are presented on scanning electron microscopy (SEM) on small intestinal biopsies of children with chronic diarrhea. In particular, there were 230 patients aged 3 months to 13 years with the following diagnoses: chronic nonspecific diarrhea, cow's milk protein intolerance, soy protein intolerance, giardiasis, cystic fibrosis, gluten-sensitive enteropathy, isolated lactase deficiency, isolated sucrase-isomaltase lactase deficiency, microvillus inclusion disease, rotavirus ententis, protracted diarrhea of infancy, chylomicron retention disease, visceral myopathy and villous asthenia.

Examination of biopsied intestinal mucosa by SEM has yielded important new information and insights on structural pathology and ultrastructural topography. Many of the observed changes helped to better …

Effects Of Tidal Stage And Sun Angles On Intertidal Benthic Microalgal Productivity, James L. Pinckney, R. G. Zingmark

Faculty Publications

Motile benthic diatoms exhibit rhythmic vertical migrations that are influenced by tidal and light cycles. As a consequence of these periodic migrations, corresponding periodicities in benthic microalgal production should occur. Using oxygen microelectrodes, hourly measurements of microalgal production were obtained from subaerially exposed cores collected from low-intertidal muddy sediments in North Inlet estuary, South Carolina, USA Microalgal productivity at low tide was twice that at high tide (mean difference 52 %) and was significantly correlated with diurnal and tidal periodicities (r² = 0.41; p < 0.0001). Production values ranged from 28.0 to 460.5 µmol O₂ mg chl a^-1 h^-1 and maximum rates were achieved during mid-afternoon low …

Scanning Electron Microscopy Of High-Modulus Polyethylene Fibres, N. H. Ladizesky, M. K. M. Pang

Scanning Microscopy

Scanning electron microscopy (SEM) examination of high modulus polyethylene (HMPE) fibres gives rise to a number of artifacts which are here recognized. Antistatic agents may be successfully used for the observation of the woven fibres, but only in conjunction with an intermediate metallic coating. For isolated threads superior results are obtained with the metallic coating alone.

New SEM evidence suggests that the high density of surface cracks produced by plasma treatment of HMPE fibres is associated with an aging process. This can also be activated by mechanical energy or storage at room conditions.

Hereditary Hair Changes Revealed By Analysis Of Single Hair Fibres By Scanning Electron Microscopy, B. Forslind, M. K. Andersson, E. Alsterborg

Scanning Microscopy

In many disorders with a genetic background the sparsity of scalp hairs may deter the clinician from trying to extract information from single hair fibres. Presenting a number of diverse conditions, we propose to show that simple measures can be taken in the doctor's office which makes single fibre analysis a useful tool for assessment of factors involved in genetic disorders including the integument and its appendages. The paper is focussed on the utilization of the scanning electron microscope with the goal of demonstrating that pertinent information can be gained where information from transmission electron microscopy and other techniques are …

Three Dimensional Intracellular Structure Of The Cochlea Using The A-O-D-O Method, A. Nagasawa, R. V. Harrison, R. J. Mount, Y. Harada

Scanning Microscopy

We have observed the three-dimensional intracellular structure of the organ of Corti and the spiral ganglion of the chinchilla using the aldehyde osmium-DMSO-osmium (A-O-D-O) method, and compared our findings with previous studies in the guinea pig. In cells of the spiral ganglion and the organ of Corti, microtubules and other cytoplasmic filaments were digested by OsO₄ during processing to provide a clear view of membranous structures such as mitochondria, endoplasmic reticulum and Golgi apparatus. The appropriate digestion time with 0.1% OsO₄ solution was found to be 60-80 hrs for the organ of Corti and 70-90 hrs for the …

Morphological Correlates Of Mechanotransduction In Acousticolateral Hair Cells, J. O. Pickles, G. W. Rouse, M. Von Perger

Scanning Microscopy

The development of ideas on mechanotransduction in acousticolateral hair cells is described, leading to the current idea that transduction depends on deflection of the bundle of stereocilia by a force parallel to the plane of the sensory epithelium. Electrophysiological experiments are summarised, suggesting that transduction depends on a shear between the different rows of stereocilia, and that the transducer channels are situated towards the tips of the stereocilia. Analysis of the ways that shear between the rows of stereocilia could be detected suggests that tip links are the structures which are most likely to transmit the stimulus-induced forces to the …

Scanning Electron Microscopy To Establish The Marble Weathering Mechanism In The Alhambra Of Granada (Spain), M. A. Bello, L. Martín, A. Martín

Scanning Microscopy

The weathering processes of the white marble from Macael quarries (Almeria, Spain) used in the Alhambra of Granada have been studied with the aim of establishing the weathering factors and mechanism. Unaltered quarry samples have been submitted to diverse accelerated weathering experiments and their morphology compared to the altered materials from the monument. The weathering process stages have been established and the degree of weathering in some monumental dependencies evaluated.

Proton Induced X-Ray Emission Analysis Of Biological Specimens - Past And Future, B. Forslind, K. G. Malmqvist, J. Pallon

Scanning Microscopy

Proton induced X-ray emission (PIXE) analysis is a comparatively new member of the family of spectrographic methods. In the last decade PIXE techniques have been applied to biological problems with great success. This review gives a condensed presentation of recent developments in biological (medical, zoological, and botanical) applications of PIXE analysis with special focus on factors which commonly influence the results, such as calibration, contamination, and preparation. The great advantage of PIXE analysis in studying physiologically important trace elements such as Zn, Mg, Fe, and Cu is underlined. Elemental mapping not only allows quantitative elemental analysis, but can also demonstrate …

Effects Of Modulated And Continuous Microwave Irradiation On The Morphology And Cell Surface Negative Charge Of 3t3 Fibroblasts, Z. Somosy, G. Thuróczy, T. Kubasova, J. Kovács, L. D. Szabó

Scanning Microscopy

Mouse embryo 3T3 cells were irradiated with 2450 MHz continuous and low frequency (16 Hz) square modulated waves of absorbed energy ranging from 0.0024 to 2.4 mW/g. The low frequency modulated microwave irradiation yielded more morphological cell changes than did the continuous microwave fields of the same intensity. The amount of free negative charges (cationized ferritin binding) on cell surfaces decreased following irradiation by modulated waves but remained unchanged under the effect of a continuous field of the same dose. Modulated waves of 0.024 mW/g dose increased the ruffling activity of the cells, and caused ultrastructural alteration in the cytoplasm. …

The Measurement Of Aluminum Surface Diffusion On Si, Sio2, And Si3n4 By Scanning Auger Microscopy, L. L. Levenson, A. B. Swartzlander, A. Yahashi, H. Usui, I. Yamada

Scanning Microscopy

The diffusion distance of Al atoms on Si(111), SiO₂, and Si₃N₄ substrates has been measured as a function of substrate temperature. These studies were carried out by depositing Al from an effusive source and from an ionized cluster beam source. Both sources were used in the same apparatus at different times. The deposition was carried out with either a slit mask or a wire mask at the substrate. After the masks were removed, the deposit was examined by optical and electron microscopy, mechanical profilometer, and Auger line scans. The diffusion distance of Al on the …

Enhancing The Laser Scanning Confocal Microscopic Visualization Of Lucifer Yellow Filled Cells In Whole-Mounted Tissue, David L. Becker, Joanna Dekkers, Roberto Navarrete, Colin R. Green, Jeremy E. Cook

Scanning Microscopy

The laser scanning confocal microscope (LSCM) is an extremely useful tool that allows fluorescently labelled cells to be visualized in whole-mount preparations. This is particularly advantageous, for example, in studying the dendritic trees of neurons with respect to their environment.

One of the most popular, and easiest, ways to visualize a cell is to inject it intracellularly with the fluorophore Lucifer Yellow (LY). However, the argon gas lasers of most LSCM's are not well matched to the excitation spectrum of aqueous LY. When this largely inappropriate excitation is combined with standard filters, designed for fluorescein fluorescence rather than Lucifer Yellow, …

The Vascularization Of The Digestive Tract Studied By Scanning Electron Microscopy With Special Emphasis On The Teeth, Esophagus, Stomach, Small And Large Intestine, Pancreas, And Liver, S. Aharinejad, A. Lametschwandtner, P. Franz, W. Firbas

Scanning Microscopy

The periodontal vessels in adult rats show a ladder-like pattern; in guinea pigs molars, by contrast, they present a honey-comb pattern. The vascular architecture in human teeth seems to be similar to that of rabbits. In guinea pigs, rats, rabbits and humans esophagus circumferential vessels give off perforating vessels. In human esophagus the number and diameter of the vessels in the submucous venous plexus decrease from proximal to distal. In the stomach the subepithelial capillary network shows a honey-comb pattern reflecting the arrangement of the gastric pits. A local portal system between the gastric glands and the surface mucosal cells …

Preparation And Characterization Of Some Particulate Materials In The Aluminum Industry, A. Csordás-Tóth, B. Szikora, J. Kürthy-Komlósy, I. Tassy

Scanning Microscopy

Preparation and characterization techniques for the following particulate materials are reviewed: micromineralogical samples of bauxite, alumina and its trihydroxide, as well as sedimentary and respirable particles. Scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDS) and image analysis were used to characterize the microminerals of bauxite. Comparisons were made among micromineralogical samples with various grain size fractions and the degree of weathering could be quantified. Programs were developed for characterization of the sandy and floury types of aluminum trihydroxide and alumina. We have used backscattered electron SEM images to characterize the size and shape of various aluminum trihydroxides. Comparison could …

Cytoplasmic Action In Development, Scott F. Gilbert

Biology Faculty Works

No abstract provided.

Carboxy-Terminal Truncation Activates Glp-1 Protein To Specify Vulval Fates In Caenorhabditis Elegans, Susan E. Mango, Eleanor M. Maine, Judith Kimble

Biology - All Scholarship

The glp-1 and lin-12 genes encode homologous transmembrane proteins that may act as receptors for cell interactions during development. The glp-1 product is required for induction of germ-line proliferation and for embryogenesis. By contrast, lin-12 mediates somatic cell interactions, including those between the precursor cells that form the vulval hypodermis (VPCs). Here we analyse an unusual allele of glp-1, glp-1(q35), which displays a semidominant multivulva phenotype (Muv), as well as the typical recessive, loss-of-function Glp phenotypes (sterility and embryonic lethality). We find that the effects of glp-1(q35) on VPC development mimic those of dominant lin-12 mutations, even in the absence …

Review Of The Wild Oat Inflorescence And Seed: Anatomy, Development And Morphology, M. V. S. Raju, David M. Sutherland

Biology Faculty Publications

This slim volume describes a detailed study of the reproductive parts of Avena fatua, the wild oat plant-a common weed in the northern plains and the probable ancestor of the cultivated oat. The book integrates the author's own work with information from available literature and includes lengthy technical descriptions of the structure and the growth of the inflorescence, the floret, the ovule, the pollen grain, the embryo, the seed, and the young seedling. Throughout the work, the author relates the wild oat's structure and development to other grasses, other monocotyledons, and other seed plants, offering evolutionary interpretations of many of …

Heterogeneity Of Crystals Attached To The Human Enamel And Cementum Surfaces After Calculus Removal In Vitro, T. Kodaka, K. Debari, M. Yamada

Scanning Microscopy

Twenty one extracted human teeth with dental calculi on the enamel and cementum surfaces, fixed in 10% neutral formaldehyde, were selected for this study. After ethanol dehydration and air drying, these calculi were removed by tweezers to observe the teeth surfaces under them. The inspection of these surfaces using SEM and EDX revealed hexahedrally based crystals including pseudocuboidal, rhombohedral and variable rugged rocky shapes. These crystals were identified as Mg-containing whitlockite. The pseudocuboidal crystals, measuring about 4.5 μmin maximum length, were widely distributed on the cervical enamel surface previously covered by calculus. On the root surface, however, these areas decreased …

Elemental Analysis And Fine Structure Of Mitochondrial Granules In Growth Plate Chondrocytes Studied By Electron Energy Loss Spectroscopy And Energy Dispersive X-Ray Microanalysis, Joanna Wroblewski, Romuald Wróblewski, Claudie Mory, Christian Colliex

Scanning Microscopy

Electron energy loss spectrometry - EELS, and energy dispersive X-ray microanalysis - XRMA, were used to study the elemental composition of mitochondrial dense granules - mdg. The study was performed on dry cut thin sections (80-200 nm) of freeze-dried and low temperature embedded cartilage. Results obtained by means of XRMA clearly showed high phosphorus and calcium content in the mdg. Using EELS at 100 kV primary voltage we found that small concentrations of elements (i.e. below typically 1% atomic weight) are difficult to analyze and map, this especially in sections thicker than 50-60 nm. Surprisingly, analysis of calcium can be …

In Vitro And In Vivo Replication For Scanning Electron Microscopy Of The Cervical Region Of Human Teeth, Joan Bevenius, Kjell Hultenby

Scanning Microscopy

A replica technique for scanning electron microscopy (SEM) of the cervical region of human teeth was evaluated on extracted premolar teeth by comparing the replicas and the original specimens in the SEM. For in vivo application, the technique was modified to circumvent contamination by saliva and gingival exudate. Impressions were taken with an addition silicone polyvinylsiloxane material and the replicas were poured in epoxy resin die material. A surface active dentine conditioner facilitated flow of the impression material into irregular surface areas; in vivo a scavenger impression was used to remove surface debris. Custom trays were made of light-cured acrylic …

Seed Coat Structure In Some Species Of Trigonella, Mohini Gupta

Scanning Microscopy

Seed coats of nine species of Trigonella, members of Trifolieae, were studied using light and scanning electron microscopy to assess seed coat characters taxonomically. In all species, the testa is of the papillose type except T. geminiflora in which it is of the multi-reticulate type. Based on some of the seed characters such as their shape, size, surface, position of hilum and the features of papillae, a key has been developed to identify different species of this genus. Further, in a highly evolved group like section Bucerates, it has been found that the surface is either papillose without …

Digitized Cathodoluminescence Imaging Of Minerals, Ian M. Steele

Scanning Microscopy

Digital imaging with cathodoluminescence (CL) capability, provides an additional, quantitative imaging perspective. While CL images can be useful by themselves, most microbeam instruments allow simultaneous acquisition of other signals including backscattered electron (BSE), secondary electron (SE), and X-ray images providing a powerful set of data for interpretation. Digital panchromatic images allow the use of standard and advanced image processing now available on laboratory computers to enhance single images or provide a means of combining information from two or more images. Other advantages of digital CL images include: 1) selective scan rates to avoid image distortion; 2) adjustable dwell times at …

Influence Of Ageing, Ph And Various Additives On Crystal Formation In Artificial Urine, A. L. Rodgers, M. A. E. Wandt

Scanning Microscopy

In order to investigate the effect of various factors on urinary crystallization processes, a series of five experiments was carried out using an artificial urine (AU) in a rotary evaporator. The influence of ageing, pH and organic, inorganic and potential inhibitory additives formed the basis of the study. Precipitates were characterized by X-ray powder diffraction, scanning electron microscopy and energy dispersive X-ray analysis. In the ageing experiment, AU aliquots, adjusted to various pH values, were allowed to stand for several days and were not evaporated. Calcium oxalate monohydrate (COM) was formed at low pH, while whitlockite, apatite and struvite occurred …

High-Resolution, Real-Space Imaging Of Conformational Structures Of Poly-L-Proline Helixes, N. J. Zheng, G. Rau, C. F. Hazlewood, C. Rau

Scanning Microscopy

In 1954, Edsall postulated that the imino-acid proline, which is a frequently found constituent of protein molecules, is a key determinant to the three-dimensional architecture of proteins. It not only should play a fundamental role in stabilizing helical structures of polypeptides, it should allow for sharp bends and even for a complete reversal of the direction of a helix looping back on itself. No direct evidence has yet been published to prove this prediction. Using scanning tunneling microscopy, we have presented high-resolution, real-space images of two conformations of poly-L-proline, where one structure clearly exhibits the predicted 180° back-folding behavior. The …

The Influence Of 17-B-Estradiol And Tamoxifen On Protein Profiles From In Vitro Cultured Preimplantation Mouse Embryos, Darrin D. Demoss

Morehead State Theses and Dissertations

A thesis presented to the faculty of the Department of Biological and Environmental Sciences at Morehead 'State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Darrin Lee DeMoss on August 16, 1991.

Localisation Of Putative Mechanoelectrical Transducer Channels In Cochlear Hair Cells By Immunoelectron Microscopy, Carole M. Hackney, David N. Furness, Dale J. Benos

Scanning Microscopy

Displacement of the apical stereociliary bundle of cochlear hair cells mechanically gates transducer channels. Knowing the position of the channels with regard to the apical structures of the hair cell could indicate how this mechanism operates. At present, there is conflicting evidence regarding their precise location; the channels have been suggested to be located either towards the base of the stereocilia or at the tips where they could be operated by extracellular links running from the top of shorter stereocilia to the sides of adjacent taller ones. The channels have been shown to be reversibly blocked by amiloride. This has …

Terminal Differentiation Of Human Fibroblasts Is Induced By Radiation, H. Peter Rodemann, Hans-Peter Peterson, Karla Schwenke, K. -Hartmut Von Wangenheim

Scanning Microscopy

In order to analyze the effect of various kinds of radiation on the terminal differentiation processes of fibroblasts in culture, both human skin and lung fibroblasts were irradiated with electromagnetic non ionizing as well as ionizing radiation in clonal and sparse mass culture systems. As analyzed by cell biological (cell type frequencies), biochemical (collagen synthesis) and molecular markers (expression of protein PIVa) human skin and lung fibroblasts are induced to differentiate prematurely into terminal postmitotic cells. Thus, both electromagnetic and ionizing radiation induce terminal differentiation in cultured cells. These data add some new aspects for the interpretation of radiation effects …

Effect Of A Platinum Chemotherapy Drug On Intracellular Elements During The Cell Cycle, Using X-Ray Microanalysis, P. G. Edwards, M. D. Kendall, I. W. Morris

Scanning Microscopy

Intracellular elemental concentrations were measured in the cytoplasm, nucleus and nucleolus of cultured Chinese hamster ovary (CHO) cells, using energy dispersive electron probe X-ray microanalysis and transmission electron microscopy. Synchronous CHO cell populations were analyzed at different times during the growth cycle. The elements K, P, Mg and Zn were all more concentrated in the nucleus and nucleolus than in the cytoplasm, while no specific subcellular compartmentalization was evident for the elements Na, Cl, Ca, Fe and S. Significant changes in intracellular elemental concentrations were associated with the progression of cells from G₁ phase to S phase of the …

Band Positions Used For On-Line Crystallographic Orientation Determination From Electron Back Scattering Patterns, N. H. Schmidt, J. B. Bilde-Sørensen, D. Juul Jensen

Scanning Microscopy

A computer procedure for on-line analysis of electron back scattering patterns (EBSP) has been developed. An experimental EBSP is computer recorded and displayed on a computer monitor. The user identifies the positions of at least two bands in the EBSP with a cursor. Based on this input the computer calculates possible crystallographic orientations. The corresponding EBSPs are simulated and superimposed on the experimental EBSP. The correct crystallographic orientation is determined from a comparison between the experimental and simulated EBSPs. Typically, the analysis takes a 10-30 seconds per pattern. Advantages with the present procedure are that it can be applied for …

The Physiology And Molecular Biology Of Iron Nutrition For Cyanobacteria, Nancy Walters Unsworth

Dissertations and Theses

In addition to nitrogen and phosphorus, iron is an essential nutrient for oceanic primary productivity. Unlike nitrogen and phosphorus however, negligible amounts of iron are supplied to surface waters through recycling or mixing but instead from the limited and sporadic input of aeolian particulate. The low concentration of iron that becomes biologically available from the dust places a serious constraint on the heavily iron-dependent processes of photosynthesis and nitrate reduction which affect primary productivity. As much as 47% of the total oceanic primary productivity can be attributed to cyanobacteria making them critical organisms in the biogeochemical cycles. This thesis addresses …