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The pressure side of human premolars subjected to experimental movement for 5-76 d were studied in the scanning electron microscope. Sham-operated and untreated premolars were used as controls. In order to study the morphology and occurrence of root resorptions, the organic tissue was removed using 1:2 diamino ethane or sodium hypochlorite and the denuded root surfaces were re-examined in the scanning electron microscope. Areas of compressed soft tissue were regularly present and the size, shape and number of such zones varied in the experimental groups. Initially, tissue affected by pressure was mainly located in the marginal region and subsequently the mid-portion of the roots became generally influenced. Removal of hyalinized tissue started shortly after the formation, and during this soft tissue removal the underlying hard tissue was resorbed. Observation of circumferentially removed, coalesced fibers corresponded with the finding of extensively resorbed lacunae in the mineralized tissue beneath. The resorptive processes of the cementum began after 10 d as round cavities measuring about 6 μm. Further resorption in cementum was characterized by numerous small, thin-walled round lacunae which confluenced into extensive, shallow resorptions after 20 d. Dentin was distinguished by the presence of tubules, and in sites of active resorption removal of mineral crystals had occurred, exhibiting a latticed fiber arrangement. [ABSTRACT FROM AUTHOR]

Sound, demineralized adult guinea pig dentin was observed by means of the scanning electron microscope. The dentinal tubules were fairly regular, some of them containing odontoblastic processes (Tomes fibers). These fibers were smooth surfaced, branching and much smaller than the surrounding tubules. Their small diameters were probably caused by the preparation procedures. The inner tubular walls were rough, probably because of interlacing collagen fibrils. The peritubular dentin was relatively compact and composed of a considerable amount of cross-striated fibrils. Similar fibrils were found in the intertubular zones where they were arranged in fiber-bundles giving the intertubular zones a honeycombed or sponge like appearance. Such a distinct honeycombed appearance was not found in transmission electron microscope studies of dentin. This discrepancy is possibly due to differences in tissue preparation. The relatively poor development of peritubular dentin compared with intertubular dentin is in agreement with other studies in animals with continued tooth growth. [ABSTRACT FROM AUTHOR]

The three-dimensional capture organs of the nematode-trapping fungus Arthrobotrys oligospora are presented in scanning electron micrographs. The fungus was grown directly on agar substrates or on millipore filters or glass cover slips placed on agar substrates. To avoid shrinkage of the soft-walled mycelial material, a fixation in OsO4-vapour was performed, before freeze-drying and coating with Au-Pd alloy. When capture organs were prepared in this way, it was possible to visualize them in their erect position in the scanning electron microscope. Young capture organs, both spontaneously formed and nematode-induced, remained standing better than old ones. An adhesive substance on the capture organs, with the aid of which nematodes are trapped, seems to be visible in these pictures. [ABSTRACT FROM AUTHOR]

Examines quartz sand grains from a tropical environment using a scanning electron microscope. Features found to be in occurrence in the quartz sand grains including solution pits, solution crevasses, and chemical etching along quartz structures.

One type of eccrine anidrosis, that caused by occlusion of the sweat pore at or near the skin surface, was studied using the scanning electron microscope. In contrast to the normal, patent eccrine ostium, seemingly amorphous, non-cellular, intraluminal material plugs the superficial pore in formalin-produced anidrosis. Interference with sweat delivery in psoriasis, also due to high-level blockage of the duct, appears to result from obstruction by abnormal cellular scale associated with the disease process. Unlike earlier investigative work, which relied primarily on indirect evidence, the scanning electron microscope allows more detailed observation of the detect which causes the sweat disorder. [ABSTRACT FROM AUTHOR]

We have used the scanning electron microscope to investigate the changes that occur in scalp hair during infection with Trichophyton violaceum. We provide information on the morphology of these dermatophytes and present evidence that their hyphae dig tunnel-like burrows into the hair shaft, dissociating hair into keratin fibrils. [ABSTRACT FROM AUTHOR]

The electroscan microscope was used to show details of the external structure of the egg of cabbage root fly. The median area between the hatching lines differs from the more solid structure of the longitudinal ridges on the rest of the surface. On the pointed posterior end are small holes in the outer layer, but in contrast to wheat bulb fly, Leptohylemyia coarctata (Fall.), there are no distinct plastron areas around the micropyle at the blunt anterior end. The egg of cabbage root fly also lacks small plastron areas among the longitudinal ridges. [ABSTRACT FROM AUTHOR]

The dinophysoid dinoflagellates (to which Ornithocercus belongs) achieve growth both by increase in size of individual wall elements and, during rapid lateral expansion associated with cell division, by the formation of a semimeridional band of material termed the megacytic zone (MZ). The MZ maintains mother cell wall integrity during complete cytokinesis of the cell body and enclosure with new wall elements. The lists, extensive wing-like extensions of the wall, can only be reformed after dissolution of the MZ. Beginning near the ventral region (which is the last region of the wall to be duplicated), the MZ dislocates and its material is apparently resorbed. The last region of attachment is invariably dorsal and in several, but not all species, the daughter cells may remain attached during early list formation by a special remnant of the MZ, termed here the dorsal megacytic bridge (DMB). After full separation of daughter cells remnants of the DMB persist for an unknown but presumably short period. The topography of this process, involving radical ontogenetic alterations in the appearance of the daughter cells and some wall surfaces, is illustrated here by the scanning electron microscope. In addition 2 aberrant types of division are shown, one of which results in a double individual, termed a geminoid. [ABSTRACT FROM AUTHOR]

A new term ‘pseudo-monilethrix’ is suggested for an unusual form of ‘beaded’ hair, found in many members of a large Caucasoid family. The abnormality bears a resemblance to classical monilethrix but is not the same condition. Other associated anomalies are formes frustes of pili torti and trichorrhexis nodosa. These disorders are traced through four generations and appear to have been inherited as an autosomal dominant trait. The clinical features and prognosis are discussed and the results of the examination of hairs under the light and scanning electron-microscopes are recorded. [ABSTRACT FROM AUTHOR]

Detailed experimental procedures are described for the preparation and examination of keratin-fibre sections by transmission scanning electron microscopy. By using these techniques, relatively large (160-nm-thick) sections of fibre bundles can be scrutinized as a routine in magnification ranges from 20 × to 50,000 X with a maximum practical resolution of about 15 nm. [ABSTRACT FROM AUTHOR]

The effect of progressive extension on the structure of human skin has been studied by scanning electron microscopy. Varying degrees of strain were imposed on abdominal skin specimens by a carefully controlled mechanical testing technique. Progressive straining has a two-stage effect on the epidermis: initial extension pulls it into a flat layer, and further extension elongates the cells. The dermal fibres reorientate, straighten, become aligned and compacted, in response to increasing strain. The onset of these changes varies through the thickness of the dermis. The effects of strain on hair follicles, glands and fat cells are described. The structural deformations are related to the mechanical behaviour of the skin, and clinical implications of the findings are discussed. [ABSTRACT FROM AUTHOR]

The article discusses new methods for surface ultrastructure. Scanning electron microscope became a practical tool in biological application in 1964-1966. The primary electron beam generated in this instrument is not meant to pass through the specimen to form an image, but to produce secondary electrons when it impinges upon the specimen surface and scans the surface. The secondary electrons coming from various parts of the scanned surface differ in amount. The freeze-fracture method is a powerful tool for examining a large area of cell membrane; conveniently, the space between the inner and outer leaflets is the most common site of cleavage in the epidermis, and the cell membrane is an important subject in the study of cancer these days.

Portion of clinically healthy epithelium from the hard and soft palate, tree and attached gingival, check, floor of mouth and lip from the vervet monkey (Cercopithecus aethiops) were examined with the light and with the scanning electron microscope. The epithelia can be subdivided histolocally into keratinized and non-kertainized types. Each of these has a definite surface appearance irrespective of the region from which they are derived. Non-Keratinized epithelia show a corrugated surface formed by microplications, while keratinized epithelia have a cratered or pitted appearance, In addition, the parakeratinized free gingival surface may be masked by the presence of pellicle. The reason for the different surface appearances is obscure but may be related to different intercellular interdigitation in the two types of epithelia. [ABSTRACT FROM AUTHOR]

Surface textures of quartz sand grains from several glacial environments at the Feegletscher, Switzerland examined by means of scanning electron microscopy are described. The difference between supraglacial and subglacial material is very slight. At the moment the interpretation of these textures must be done with care until the full statistical relation to environments can be ascertained. This does not necessarily invalidate earlier investigations although it does mean that glacial and extraglacial environments in the vicinity of glaciers are apparently not distinguishable. Examination of surface precipitation features suggests a sequence of events which can be used to help discriminate between different ages of deposits in an area. A similarity between some of the surface debris from moraine samples and those seen in loess and quickelay deposits is also suggested. [ABSTRACT FROM AUTHOR]

This article presents technical abstracts and notes related to police science. The article "Forensic Applications of the Scanning Electron Microscope," by I. Covin and O. Jahari, presents the proceedings of a forensic workshop held in May, 1971. The article " The Status of Polygraph Legislation of the Fifty States," by Clarence H.A. Romig, discusses the history of the polygraph, the physiological and psychological aspects involved, and the legal status of the polygraph in the United States; part two of this paper continues with the various uses being discussed and concludes by presenting both sides of the argument over the use of the polygraph. The concluding segment covers legislation affecting the use of the polygraph including licensing legislation in eleven states. The series is concluded with a model set of minimum standards for operator certification and regulation. The article " Ubiquitous Reds: A Local Perspective on Secobarbital Abuse," by Bryan S. Finkle, discusses the social background and results of a study and evaluation of secobarbital abuse in Santa Clara County, California. The study also reports the results of analytical analysis showing great variations of the secobarbital content of capsules and also shows that the blood levels are significantly in excess of therapeutic levels which is a possible explanation for a rapid use in secobarbital fatalities among young people and the drug involvement in road traffic accidents.

Hair identification is a complex and important problem in view of forensic investigation. It entails many tests and uncertainties still exist in drawing final conclusions to determine whether a single hair is identifiable from a certain individual. The Scanning Electron Microscope alone may not be able to cause final conclusions to be drawn, however, with further tests and comparative studies, this type of study certainly will eventually lead to a more positive identification of hairs, since it definitely shows improvement over the optical means of identification regarding structural, surface morphology, coupled with other scientific data. [ABSTRACT FROM AUTHOR]

An account is given of experiments in which samples of wool fibres were heated in an oven for various times, and at different temperatures, and examined in a scanning electron microscope. Samples were also subjected to the Allwörden test and to a dye-absorption test. It is shown that, on exposure to dry heat, wool fibres retain their physical shape and characteristics, even under severe conditions, the only major change initially being discoloration. Only at temperatures of 160°C and above are serious physical changes, such as scale deformation and changes in X-ray-diffraction patterns, observed. [ABSTRACT FROM AUTHOR]

Two methods for the replication of skin surface are described. The first is for the macroscopic estimation of hair follicles. The second, which produces replicas for the scanning electron microscope, utilizes Formvar and Thiokol Rubber as the impression material. The replica exhibits fine microscopic detail, and demonstrates sweat gland activity. The technique does not displace the well documented Sylflo method, but may prove to be a useful adjunct. [ABSTRACT FROM AUTHOR]

This report describes studies of stratum corneum from normal subjects and from patients with various scaly disorders, with the scanning electron microscope, using the skin surface biopsy technique. Normal squamous cells showed essentially the same structure in different parts of the body; Individual squames demonstrated irregular surface folds. convolutions and occasionally a more villous appearance. In dominant ichthyosis vulgaris the squamous cells showed predominantly an irregular fine nodular surface pattern. Similar changes were found in non -bullous ichthyosiform erythroderma. Surface depressions (maximum diameter approximately 300 nm) were occasionally seen on squames from bullous ichthyosiform erythroderma. Psoriatic squamous cells showed a more pronounced villous pattern than normal squames, the villi being evenly distributed over the surface of the majority of cells examined; some cells had rather flattened villi near their edges. Possible physiological roles for the structural changes found are discussed. [ABSTRACT FROM AUTHOR]

The fractured ends of exclamation mark hairs were found to be quite distinct from those of normal hairs broken by traction when examined with the scanning electron microscope. The cuticular scales of exclamation mark hairs, telogen hairs from around lesions, hairs from unaffected parts of the scalp, and hairs from normal subjects were found to possess smooth edges when first produced. More distally, however, the edges of the scales became jagged, although their configuration remained unaltered, in all cases. [ABSTRACT FROM AUTHOR]

The fibrous networks of the dermis have been studied in normal skin, solar elastosis and pseudo-xanthoma elasticuin, using the scanning electron microscope. In normal skin the fibrillary structure of the collagen bundles was clearly seen; closely related to the collagen fibres and crossing between them was a branching network, probably comprised of elastic fibres. The sub-papillary dermis of solar elastosis revealed few normal collagen bundles being made up of an irregular homogenous network. In the middermis and lower dermis of pseudo-xanthoma elasticum there was a dense network of branching, curled and tangled fibres. [ABSTRACT FROM AUTHOR]

The cyanoacrylate adhesives have been used to examine the superficial horny layer in a horizontal plane. The adhesive strips a thin layer of horn from the skin and sticks it to glass slides. The preparations are superior to skin surface replicas because of the ease and speed of their production and because of their unfailing clarity. In addition, because actual horn is seen in its in vivo arrangment, the preparations can be stained histologically and histochemically. The results of examination of normal skin and its regional variation, and of viral and seborrhoeic warts, moles, pityriasis versicolor, psoriasis and ichthyosis are reported. The scanning electron microscope has been used to examine the horny squames removed with this technique from normal, ichthyotic and psoriatic skins. In psoriatic squames a particularly well developed series of folds and outpouchings of the plasma membrane were noted. [ABSTRACT FROM AUTHOR]

The electron microprobe with scanning electron microscope attachment was used to characterize the topographic appearance of cut tooth surfaces and to identify the remaining debris chemically. Tooth debris and organic films were present on all cut surfaces. The surfaces appeared rough, and a smeared layer was observed at high magnifications. [ABSTRACT FROM AUTHOR]

This article informs that thirteen fossil Erica-type seeds extracted by D.G. Wilson from samples collected from the Cromer Forest Bed Series at Pakefield, Suffolk, and Beeston, Norfolk, were examined in the Cambridge Stereoscan Mark II scanning electron microscope at the New University of Ulster. Of the thirteen fossil seeds examined under S.E.M. five were assigned with varying degree of certainty to Erica lusitanica. They could be distinguished from Bruckenthalia spiculifolia on the basis of the characteristics already noted. One seed was tentatively identified with Erica tetralix L., though poor preservation made confirmation impossible. All but one of the remainder were too poorly preserved to permit confident identification.

Unpollinated, cross-pollinated and self-pollinated stigmas of Brussels sprouts and kale were examined in a scanning electron microscope as fresh uncoated specimens. The stigmatic papillae are closely appressed in young stigmas, but are held apart in the mature stigma by the swollen bases of the papilla cells. Some self-pollen tubes show obvious signs of inhibition by being very short, or by coiling over the surface of the papilla without penetrating it. Other self-pollen tubes appear to behave like cross-pollen tubes by producing tubes which penetrate papillae directly. The implications of these observations for the identification of the site of the incompatibility reaction are discussed. [ABSTRACT FROM AUTHOR]

The morphology of the inner and outer surfaces of cuticular membranes of mono- and dicotyledonous leaves and fruits was studied with the scanning electron microscope. Variations in surface structure are related to differences in thickness and composition of the membranes. Delicate leaf membranes have fine ridges and simple stomata, well-developed membranes, thick V-shaped ridges and heavily cutinized stomata. Fruit membranes show deep ridges and extensive secondary cutinization. The most heavily cutinized structures occur in membranes which yield high proportions of 10, 16-dihydroxyhexadecanoic or 9,10,18-trihydroxyoctadecanoic acid which suggests that the membrane thickness and the complexity of the structural features are associated with the degree of hydroxylation of the constituent cutin acids. The relationship between the structure and composition of the cuticular membrane and the type and growth habit of the plant is discussed. [ABSTRACT FROM AUTHOR]

Stephanodiscus invisitatus Hohn and Hellerman, studied by means of light, transmission, and scanning electron microscopy, shows a range of frustule diameters from 6.4 to 13.3 μ. Variation in valve ornamentation can be correlated with specimen diameter. The striae number ranges from 16 to 20 in 10 μ. Various processes difficult to observe by light microscopy alone are described which arise from the inside and outside of the frustules.[SUP2] [ABSTRACT FROM AUTHOR]

The article discusses observations of the external anatomy of oribatid mites through the scanning electron microscope (SEM). It observed that these mites have infracapitulum extended legs that bent beneath the body of the lamella and the pteromorph. It showed a dorsal view of their gnathosoma and rostrum, and their rostral hairs are inserted near the distal tips of their tutorium on each side. It has also demonstrated the internal ridges and the slightly tuberculated surface of the mites' bothridial cavity. It seems that SEM will become an instrument for the disclosure of many remarkable features of the external and internal structure of many organisms.