bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of gender and anaesthesia type on day surgery anxiety
Authors: Mitchell Mark 
Published: August 2011

mitchell m. (2011) Influence of gender and anaesthesia type on day surgery anxiety. Journal of Advanced Nursing 68(5), 1014–1025.AbstractAim.  To investigate the possible influence of gender and anaesthesia type on anxiety prior to day surgery.Background.  Elective surgery undertaken on a day, short stay or ‘day of surgery’ basis is growing and much emphasis also placed on ‘enhanced recovery’ for in‐patient surgery. During such brief episodes preoperative apprehension can be considerable but the opportunity to help reduce anxiety is minimal and formal plans uncommon.Method.  As part of a larger study, a questionnaire was distributed to 1606 patients undergoing day surgery, with anaesthesia (2005–2007). Participants were requested to return the questionnaire by mail 24–48 hours following surgery, with 674 returned. Data were analysed using descriptive statistics and multivariate analysis of variance.Results.  Of the total patients 82·4% experienced anxiety on the day of surgery with the wait, anaesthesia and possible pain being common anxiety‐provoking aspects. The majority preferred to receive information between 1–4 weeks in advance and participants experiencing general anaesthesia required information at a statistically significantly earlier stage. General anaesthesia patients were statistically significantly more anxious than local anaesthesia patients and desired more information. Female patients were statistically significantly more anxious, anxiety commenced earlier and they preferred to wait with a relative/friend or talk with other patients.Conclusions.  Anxiety was experienced by the majority of participants but was more prevalent amongst general anaesthesia and female patients. For general anaesthesia patients, a comprehensive level of information may be required a number of weeks prior to surgery and gender differences associated with the preoperative wait may require greater consideration.
Low‐contrast development of electron micrographs
Authors: Farnell G. C. , Flint R. B. 
Published: August 2011

SUMMARYFrom the fact that the response of photographic materials conforms to the ‘single‐hit’ expression for exposure to electrons of the energies used in electron microscopy, it follows that the density log exposure curves have a shape substantially independent of the degree of development in conventional solutions. The only way in which the density range corresponding to a given ratio of intensities in the image can be reduced is by reduction of the exposure. The visibility of low‐intensity detail in the image is adversely affected, however. A developer formula is presented with which the density contribution per electron decreases with increasing exposure so that contrast is less than if determined solely by the nature of the exposure. The effectiveness of the solution is demonstrated and practical recommendations are made regarding its use.
The structure and formation of the egg membranes in Nasonia vitripennis (Walker) (Hymenoptera, Pteromalidæ)
Authors: Richards J. G. 
Published: August 2011

SUMMARYA histochemical and fine structural study of the vitelline membrane and chorion was carried out. Following the uptake of protein at the oöcyte plasma membrane during yolk synthesis, the egg membranes are laid down in sequence in the intercellular space between the oöcyte and the follicle cells. The follicular epithelial cells alone contribute towards their formation. The structure of the chorion is much simpler than that of Bombus, the only other hymenopteran previously investigated.
The effect of refractive index of the mounting medium on the apparent diameter of latex particles and glass fibres
Authors: Skene Donald S. 
Published: August 2011

SUMMARYThe diameters of latex particles were measured in different media with a light microscope. The microscope was fitted with a filar micrometer eyepiece and, for measurement, the cross‐wire was set on the centre of the dark line forming the edge of the image. Electron microscopy was used for comparison. Good agreement between light and electron microscopy was obtained using media of relative refractive index (nd object/nd medium) between 1·06 and 1·08. With higher relative refractive indices the light microscope underestimates dimensions for particles 4·17 μ diameter and overestimates for particles 2·7 μ diameter.
Electron phase and amplitude images of stained biological thin sections
Authors: Haydon Glen B. 
Published: August 2011

SUMMARYVery‐high‐resolution electron microscopy demonstrates similar phase image ‘particles’ in uncontaminated, unsupported thin sections of epoxy‐embedded biological material and in simple thin carbon films, both of which show better than 5 Å resolution. Under such conditions it is possible to examine biological specimens for amplitude images well below the 20 Å limit commonly accepted for such preparations. With this very high resolution discrete amplitude images are found in sections after treatment with heavy‐metal stain. These amplitude images are as small as 10 Å, a size equal to that of lead aggregates, which they may represent.
Comparative studies on the ultrastructure of the thyroid parafollicular C‐cells
Authors: Welsch U. , Flitney E. , Pearse A. G. E. 
Published: August 2011

SUMMARYA comparative study of the fine structure of the parafollicular C‐cells in the thyroid glands of two rodents (guinea‐pig and mouse), and a primitive primate (Tupaia glis), shows a large number of similarities with the previously reported findings of several authors.In two of the three species the C‐cells possess numerous long cytoplasmic processes and they are preferentially elongated or ovoid in shape. This accords with their optical‐microscopic appearance in pig thyroid, but the feature appears not to have been recorded previously at electron‐microscope level.The finding of ‘dark’ and ‘light’ cells is confirmed and it is suggested that the dark cell represents a different (degenerative) physiological state. The electron‐microscope appearance, however, may be due partly to differential retention of cytoplasmic components (including possibly biogenic amines), and hence they may be partly fixation artifact.Other notable features of the C‐cells, such as microtubules and cilia, are recorded and discussed. The primary importance of fixation is particularly stressed.
The surface structure of mouse peritoneal cells—a study with the scanning electron microscope
Authors: Carr Ian , Clarke J. A. , Salsbury A. J. 
Published: August 2011

SUMMARYNormal and stimulated peritoneal cells have been examined with the Stereo‐scan scanning electron microscope. Normal lymphocytes were identified by their small size; some had numerous small stubby or pointed processes on their surfaces. Macrophages were larger and had ridge‐like processes. Many of the stimulated cells showed no significant deviation from normal. Others, all macrophages, showed a marked deviation from the normal spherical shape. Ridge‐like processes were more prominent on their surfaces, and large flange‐like processes and a few finger‐like processes were seen. This suggests that on stimulation peritoneal cells become more deformable and therefore irregular in shape, and that their surfaces become rougher.
An electron‐microscopic study of cholinesterase distribution in the rat adrenal medulla
Authors: Lewis P. R. , Shute C. C. D. 
Published: August 2011

SUMMARYThe distribution of cholinesterase activity in the rat adrenal medulla was studied after initial fixation with glutaraldehyde, which preserves the osmiophilia of the noradrenaline‐containing cells. Staining for true cholinesterase activity was associated with all the identifiable elements of the preganglionic sympathetic innervation. The morphology and enzyme staining of the endings on the chromaffin cells was similar to that seen in cholinergic synapses in the central nervous system. The endings contained occasional dense‐cored vesicles and the possible significance of such vesicles at an undoubted cholinergic synapse is discussed. Staining for pseudocholinesterase activity, by contrast, was associated particularly with the Schwann cells and to a lesser extent with the chromaffin cells, but not with the axons and their processes.
A phase‐contrast device with positive and negative image contrast
Authors: Pluta M. 
Published: August 2011

SUMMARYA phase‐contrast device comprising objectives provided with two concentric phase rings, one positive and one negative, and a condenser with aperture diaphragm provided with two concentric transparent rings conjugate with the phase rings and covered by two crossed polarizing films, is described. The change of image contrast from positive to negative, and vice versa, is obtained by rotation of a polarizer placed before the condenser or above the objective. Properties and advantages of the device are discussed.
The refractive index and dry mass distribution of mammalian erythrocytes
Authors: Thaer A. 
Published: August 2011

SUMMARYQuantitative microscopical methods are now of outstanding importance in the diagnosis and assessment of mammalian red blood cells.After release from the erythropoetic organs, all red blood cells in the peripheral blood of mammals pass through the reticulocyte stage before becoming mature erythrocytes. Therefore, the determination of reticulocyte number is used as an index of erythropoetic activity in clinical hæmatology.The corpuscular solid concentration, the corpuscular dry weight, the osmotic resistance and the size of red blood cells can be determined by use of microscopical methods. For the determination of the corpuscular solid concentration of erythrocytes, cell refractometry by the use of phase‐contrast microscopy has proved to be a very sensitive and accurate method. The dry weight of single erythrocytes may likewise be obtained by the use of interference microscopy with relatively high accuracy. Both of these methods might also be of use in clinical hæmatology.In the experimental work described in this paper, both methods mentioned above are used to answer the question: whether and under what conditions the refractive index as a criterion of measurement of the solid concentration and the relative dry weight can be determined separately for reticulocytes and erythrocytes from the same blood sample by use of microscopical methods alone. The frequency distributions of refractive indices and relative dry weights determined on human reticulocytes and mature erythrocytes show significantly lower mean values for the reticulocyte generation in accordant with findings published by other authors and obtained by use of sometimes entirely different methods. The additional information gained by the determination of the frequency distribution of refractive index and dry weight of reticulocytes and mature erythrocytes separately in a blood sample and the necessity for simplifying and automating such methods for hæmatological diagnosis are discussed.
Studies on insect fibrous proteins: the structural protein of the ootheca in the praying mantis, Sphodromantis centralis Rehn
Authors: Kenchington W. , Flower N. E. 
Published: August 2011

SUMMARYHistological studies have been made on the left colleterial gland which secretes the α‐type structural protein in the ootheca of Sphodromantis centralis. Three distinct types of secretory cell are present in the gland wall, and each has a complex apical ‘end‐apparatus’ composed of closely packed canalicules radiating from a central cavity. Structural protein is synthesized in the cytoplasm, passed through the canalicules into the cavity of the end‐apparatus, and extruded into the lumen as strongly birefringent, apparently membrane‐free globules. At this stage the globules consist of numerous concentric layers of long, parallel fibrils, 0·05–0·1 μm in diameter. In each successive layer the fibril direction is rotated through an angle of about 18° about an axis perpendicular to the layers, in the manner of cholesteric phase systems. When sectioned, the globules reveal a regular ‘lamellated’ structure similar to that apparent in sections of some insect and crustacean cuticles. A three‐dimensional model has been constructed to illustrate this phenomenon. During ootheca formation fibrils become transformed into thin ‘crystalline’ ribbons, about 15 μm long, 1–2 μm wide and 200–300 Å thick. Very regular diamond‐shaped ribbons may be obtained in vitro by mixing structural protein globules from dissected left glands with optimum concentrations (0·005–·025 m) of calcium chloride in unbuffered solution. Experiments suggest that calcium ions play an important part in the natural process of ribbon formation.
Observations on the fine structure and development of the spindle at mitosis and meiosis in a marine centric diatom (Lithodesmium undulatum)
Authors: Manton I. , Kowallik K. , Stosch H. A. von 
Published: August 2011

SUMMARYA spindle precursor is shown to be a relatively constant feature in non‐dividing cells of Lithodesmium undulatum and its structure is described and illustrated. It is a small somewhat rectangular body closely pressed to the nuclear envelope and composed of a series of parallel plates of semi‐opaque material placed edgeways on a square ground plan about 0·6 μm in length and breadth. The plates at each end are the densest and the next most dense marks the centre. During prophase in the spermatogonia the spindle proper is laid down between the precursor and the underlying nuclear envelope. It consists of tubules which increase in size and number as prophase advances, the spindle poles being marked by extensions from the terminal plates of the precursor, the rest of which ultimately breaks down, thereby permitting rapid elongation of the spindle itself to take place. After breakdown of the nuclear envelope, the spindle sinks into the mass of chromosomes, as previously described with the light microscope in other diatoms. The fine structure of the metaphase spindle is described and illustrated, special attention being paid to the number and arrangement of the component microtubules, both in a normal cell and a giant cell. Anaphase is not examined but a few stages of telophase are added, including some stages of cleavage. The results are discussed in a preliminary way pending completion of a study of meiosis. Points raised include consideration of a possible homologue of the so‐called centrosome of pennate diatoms and certain aspects of the numerical relation between chromosomes and spindle tubules.
A sandwich‐embedding technique for monolayers of cells cultured on Araldite
Authors: Smith W. , Gray E. W. , Mackay J. M. K. 
Published: August 2011

SUMMARYA method of culturing cell monolayers on Araldite to facilitate selection and sectioning of specific cells is described. The method was originally developed for the selection of virus‐induced multi‐nucleate cells, but is applicable to other systems.
Endocytosis: The different energy requirements for the uptake of particles by small and large vesicles into peritoneal macrophages
Authors: Casley‐Smith J. R. 
Published: August 2011

SUMMARYThe uptake of various, different‐sized particles by macrophages was studied using the electron microscope. In addition to observing normal cells, cells were examined which had been inhibited by exposing them to low temperature (4°C), and to a number of metabolic poisons.It was found that large particles (> 01 μm) enter the cells and are contained in large vesicles (0·1–5 μm). Small particles (< 50 nm) may also enter the cells by this process. They enter most frequently, however, by passing into small (∼ 70 nm) vesicles. These may later coalesce and their contents adhere to give a second kind of large vesicle.The various inhibitors prevented the ingestion of the large particles (and of the small particles en masse) into large vesicles, but did not prevent their initial adsorption onto the plasma membranes. They did not prevent nearly normal numbers of small particles from entering the pre‐existing small vesicles, nor their subsequent fusion into the second class of large vesicles.
Quantitative studies on the preservation of choline and ethanolamine phosphatides during tissue preparation for electron microscopy
Authors: Cope G. H. , Williams M. A. 
Published: August 2011

SUMMARYThe loss of 14C‐ethanolamine‐ and 3H‐choline‐labelled phospholipids from rat liver during preparation for electron microscopy by some less frequently used processing methods has been examined. Permanganate and formaldehyde‐potassium dichromate fixation followed by Araldite embedding were investigated and five procedures involving embedding in water‐miscible methacrylates (GMA). These procedures included a conventional method of dehydration and embedding in GMA, a low‐temperature GMA embedding method, dehydration with ethylene glycol, freeze drying and freeze substitution. These results are compared with those obtained after conventional tissue preparation (presented previously, Cope & Williams, 1969). Formaldehyde‐potassium dichromate compared favourably with the conventional procedures for the preservation of both phosphatides, especially phosphatidyl ethanolamine. Permanganate fixation was much less effective. Severe loss of both phosphatides occured after freeze drying and freeze substitution in glutaraldehyde‐alcohol. GMA is shown to be a more potent phospholipid solvent than ethanol under the conditions employed. Low‐temperature embedding reduced the loss of phosphatidyl choline during embedding. Results obtained by scintillation counting were confirmed by grain counts on thick‐section autoradiographs. No direct relationship between extraction and the electron‐microscopic appearance of membranes was discernible. It is believed that membrane prominence is largely dependent upon the electron density of the surrounding cytoplasm rather than on the degree of phospholipid extraction.
A stable iron‐hæmatoxylin solution for staining the chromatin of cell nuclei
Authors: Slidders W. 
Published: August 2011

SUMMARYBy using ferrous sulphate as mordant, sodium iodate as oxidant and aluminium chloride as stabilizer, it proved possible to formulate a stable single‐solution iron‐hæmatoxylin. This provides a resistant nuclear stain, sufficiently acid‐fast to be suitable for counterstaining with van Gieson or the trichrome methods. This solution, ferrous hæmatein, can replace the celestin blue‐hæmalum sequence.
A new acridine orange method for staining nucleic acid and its application to germinating wheat seeds
Authors: Price C. E. 
Published: August 2011

SUMMARYA new method of nucleic acid staining based on acridine orange is described and applied to sections of wheat seed. The coleorhiza of the ungerminated seed has an RNA content as high as the embryonic leaves and roots. During the first 24 h of germination the RNA levels of the roots, leaves and scutellum remain relatively unchanged while that of the coleorhiza falls to a low level. The possibility is discussed that the rapidly‐mobilized RNA functions as a storage product which is hydrolysed and incorporated into fresh RNA in the adjacent embryo during germination.
The effect of glycerol on the structure of lecithin membranes; a study by freeze‐etching and X‐ray diffraction
Authors: Buckingham J. H. , Staehelin L. A. 
Published: August 2011

SUMMARYThe structure of bimolecular lecithin leaflets (or bilayers) has been studied in lecithin–water and lecithin–glycerol–water systems using freeze‐etch and X‐ray diffraction techniques.The X‐ray diffraction experiments indicate that the thickness of these bilayers increases both with increasing lecithin concentration and with the addition of glycerol. Due to the glycerol‐induced thickening of the bilayers the limiting value of about 5 nm is reached at a lower lecithin concentration (70% lipid) in glycerol‐treated systems than in specimens prepared with pure water (75% lipid). It is suggested that the addition of glycerol increases molecular order within the bilayers by ‘cross‐linking’ the polar end‐groups of the lecithin molecules. The resultant straightening of the molecules increases the bilayer thickness for all concentrations below 75% lecithin.The freeze‐etch studies show that the fracturing properties of the bilayers at −100°C change both when the concentration of lecithin increases from 1% to 80% and when glycerol is added to the preparations. The appearance of all the exposed membrane faces can be explained by a bilayer arrangement of the lecithin molecules. At concentrations below 75% lipid in lecithin‐water systems and concentrations below 70% lipid in glycerol‐treated specimens the membrane faces are usually covered with plaque structures, which represent island‐like remnants of the partly split away upper‐lying layer of the bilayers (Staehelin, 1968a). Above these concentrations most bilayers are completely split during the fracturing process. The freeze‐etch results also support the idea that glycerol strengthens the cohesive forces in the surface layers of the bilayer membranes and indicate that plaque formation depends on the presence of ‘free’ water between the bilayers.A parallel freeze‐etch investigation of the hydration of bulk lecithin has shown that it could be a two‐step process. In the first stage the lecithin molecules appear to be arranged into bilayers while the bound water layer is formed. In the second stage the free water seems to penetrate as a sheet in between the bound water layers of the lipid bilayers and forces them apart.Possible biological implications of these studies are briefly discussed.
The analysis of polarized light using a stereographic projection of the Poincaré sphere
Authors: Mallon H. D. 
Published: August 2011

SUMMARYThe mathematical analysis of a beam of polarized light into two constituent beams of plane‐polarized light vibrating at right angles to each other and with a difference of phase, can be somewhat time‐consuming. This paper describes a graphical method of solution, of reasonable accuracy, which can be carried out rapidly. The simple geometry of the representation of a polarized beam as a point on the surface of the Poincaré sphere is explained together with the stereo‐graphic projection of the surface of the sphere on a diametral plane. Examples are given of the use of the stereogram in conjunction with the polarizing microscope for the determination of phase difference of a transparent crystal, for the determination of the state of polarization after transmission through a bire‐fringent crystal and for the analysis of superimposed crystals.
A method for determining the fibrillar angle in wood tracheids
Authors: Page D. H. 
Published: August 2011

SUMMARYThe predominant direction of fibrils in isolated walls of wood tracheids can be determined from observation of the extinction position in the polarizing microscope. This method cannot be used directly to obtain the fibrillar direction for separate intact cells, because the light path must traverse the opposite walls of the cell, the fibrillar angles of which are similar but of opposite sense.This difficulty may be overcome by impregnating the cell lumens with mercury and using incident (epi‐) illumination with crossed polars. The incident light now passes through the upper wall of each cell, suffers reflection at the mercury surface and returns through the same wall. The extinction position gives the predominant fibrillar direction of the upper wall.The method is rapid, has been found suitable for tracheids in wood, wood pulp and paper, and should be of value for the study of other plant cells such as cotton.