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1
Furuno, Takeshi. "Bark Structure of Deciduous Broad-Leaved Trees Grown in the San'in Region, Japan." IAWA Journal 11, no. 3 (1990): 239–54. http://dx.doi.org/10.1163/22941932-90001181.
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The bark anatomy of 55 deciduous broadleaved tree species from the San'in Region is described. Anatomical features of ray and axial parenchyma cells, phloem fibres, and sclereids are tabulated. Individual species have their own characteristic bark structure. The diversity in tissue arrangement in the secondary phloem could be classified according to the following types: 1a. Phloem fibres in concentric bands alternating with bands ofaxial parenchyma devoid of crystals and sieve elements; 1b. Fibre-sclereids (sclerotic fibres) in concentric bands; 2. As 1a, but fibre bands f1anked by chambered crystalliferous parenchyma; 3a. Broad rays sclerified and extending fanwise or with a very large clump of sclereids; 3b. In species with only narrow wood rays, part of the rays dilated to produce fanwise extensions; 4. Aggregate rays with fanwise extensions; 5. Phloem fibres in round or spindle-shaped clusters or irregular, short bands; 6. Phloem sclereids in round or spindle-shaped clusters or irregular, short bands; 7. Diffuse distribution of all phloem elements; 8. Convergence ofrays towards the cortex.
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Hamza, A. A., T. Z. N. Sokkar, M. A. El-Bakary, and A. M. Ali. "Variable wavelength microinterferometry applied for irregular fibres." Journal of Optics A: Pure and Applied Optics 4, no. 4 (May 23, 2002): 371–76. http://dx.doi.org/10.1088/1464-4258/4/4/301.
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Hamza, A. A., M. A. Amer, H. I. Abd El-Kader, and A. M. Nasr. "Interferometric studies on fibres with irregular transverse sections." Polymer Testing 12, no. 4 (1993): 299–310. http://dx.doi.org/10.1016/0142-9418(93)90037-p.
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Hippeli, Susanne, Kerstin Dornisch, Thorsten Wiethege, Adrian Gillissen, Klaus-Michael Müller, and Erich F. Elstner. "Biological Durability and Oxidative Potential of Man-Made Vitreous Fibres as Compared to Crocidolite Asbestos Fibres." Zeitschrift für Naturforschung C 56, no. 7-8 (August 1, 2001): 633–48. http://dx.doi.org/10.1515/znc-2001-7-825.
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In this study we investigated relationships between redox properties and biodurability of crocidolite asbestos fibres and three different man-made vitreous fibres (MMVF): traditional stone wool fibres (MMVF 21), glass fibres (MMVF 11) and refractory ceramic fibres (RCF). Each fibre type was incubated up to 22 weeks in four different incubation media: gamble solution (GS) pH 5.0 and pH 7.4, representing blood plasma without proteins, and surfactant like solution (SLS) pH 5.0 and pH 7.4. During incubation time aliquots of incubation mixtures were removed and analysed in a biochemical model reaction, mimicking activated phagocytes. In addition, changes of fibre morphology and chemical composition were examined using SEM-and EDX-technology.In the presence of crocidolite asbestos fibres and MMVF 21 the formation of OH-radicals according to the Haber-Weiss sequence could be demonstrated, whereas MMVF 11 and RCF showed no reactivity. Crocidolite asbestos fibres exhibited a significant higher activity compared with the stone wool fibres at the onset of incubation. The oxidative capacities of these fibre types were shown to depend on both specific surface area and iron content. The oxidative potentials of crocidolite asbestos fibres as well as MMVF 21 were not constant during incubation over several weeks in each incubation medium. The reactivities showed sinoidal curves including reactivities much higher than those at the onset of incubation time. These irregular changes of oxidative capacity may be explained by changes of the redox state of fibre surface-complexed iron.Furthermore our results showed clear differences between incubation of fibres in GS and SLS, respectively, indicating that phospholipids play an important part in fibre dissolution behaviour and oxidative reactivity.In conclusion we suggest, that biodurability testing procedures should not exclusively concentrate on dissolution rates of fibres. They should include fibre characteristics concerning known pathogenic mechanisms to evaluate the real toxic potential of the fibre type looking at. Secondly we suggest, that phospholipids should be constituents of incubation liquids used for standardised fibre biodurability test procedures thus representing more realistic incubation conditions
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Hamza, A. A., T. Z. N. Sokkar, and M. A. Kabeel. "Multiple-beam interferometric studies on fibres with irregular transverse sections." Journal of Physics D: Applied Physics 18, no. 9 (September 14, 1985): 1773–80. http://dx.doi.org/10.1088/0022-3727/18/9/008.
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El-Tonsy, M. M. "Stress birefringence in compressible polymer fibres with irregular transverse sections." Journal of Materials Science 26, no. 11 (1991): 2857–60. http://dx.doi.org/10.1007/bf01124813.
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Wang, Chong, and Min Wang. "Formation of Core–Shell Structures in Emulsion Electrospun Fibres: A Comparative Study." Australian Journal of Chemistry 67, no. 10 (2014): 1403. http://dx.doi.org/10.1071/ch14214.
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Electrospinning has attracted great attention in recent years from different industries including biomedical engineering. Owing to the relative ease of fabricating ultrafine fibres with core–shell structures, emulsion electrospinning has been investigated intensively for making nanofibrous delivery vehicles for local and sustained release of bioactive or therapeutic substances, especially biomolecules such as growth factors. In preparing emulsions for electrospinning, different surfactants, ionic or non-ionic, can be used, which may subsequently influence the evolution of the core–shell structure in the electrospun emulsion jet or fibre. In this investigation, emulsions consisting of deionized water or phosphate buffer saline as the water phase, a poly(lactic-co-glycolic acid) solution as the oil phase and Span 80 (a non-ionic surfactant) or sodium dodecyl sulfate (an ionic surfactant) were electrospun into fibres for studying the core–shell structure and its evolution in emulsion electrospun fibres. Different microscopies were employed to study the morphological changes of the water phase in fibre samples collected at different locations along the jet (or fibre) trajectory during emulsion electrospinning. It was found that the evolution of the fibre core–shell structure was significantly different when different surfactants were used. If Span 80 was the surfactant, the water phase within the thick emulsion jet (or fibre) close to the Taylor cone existed in a discrete state whereas in ultrafine fibres collected beyond a certain distance from the Taylor cone, a mostly continuous water-phase core was observed. If sodium dodecyl sulfate was the surfactant, the core–shell structure in the thick jet (or fibre) was irregular but relatively continuous. A single core core–shell structure was eventually developed in ultrafine fibres. The core–shell structure in electrospun fibres and its evolution were also affected by the emulsion composition (e.g. polymer solution concentration, water-phase volume, and ion addition in the water phase).
8
Yu, J. "Elastic tissues of the intervertebral disc." Biochemical Society Transactions 30, no. 6 (November 1, 2002): 848–52. http://dx.doi.org/10.1042/bst0300848.
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Elastic fibres have been generally considered to play no significant role in the mechanical functioning of the intervertebral disc since earlier studies reported that the elastic fibre network was sparse and irregular. However, a recent study has reported that the network is highly organized and that the distribution and orientation of elastic fibres varies from region to region. In the annulus, elastic fibres appear densely distributed in the region between the lamellae and also in ‘bridges’ across the lamellae. They are also organized in the nucleus where long straight fibres are radially oriented and anchor perpendicularly or obliquely into the cartilaginous endplate. Immunohisto-chemistry using specific antibodies indicates that elastin is present in the network, as is fibrillin. Biochemical studies show, however, that the amino acid composition of the residue remaining after alkaline (NaOH) extraction or CNBr digestion contains a higher concentration of polar amino acids than ligamentum nuchal elastin. The composition of the residue suggests that disc elastin may cross-link strongly with some other matrix components. With such coupling, it is thought that elastic fibres could play a significant mechanical role even though overall elastin is less than 5% of the total dry weight of the disc.
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Moradi, Sepehr, Xin Liu, Saeed Shaikhzadeh Najar, and Xungai Wang. "Tensile strength prediction of irregular fibres using diameter-dependent Weibull analysis." Journal of The Textile Institute 110, no. 4 (September 26, 2018): 600–605. http://dx.doi.org/10.1080/00405000.2018.1500087.
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URIZ, MARÍA J., and EMMA CEBRIAN. "Presence of the IndoPacific genus Petrosaspongia Bergquist, 1995 (Porifera: Demospongiae) in the Atlantic with description of a new species (P. pharmamari n. sp.)." Zootaxa 1209, no. 1 (May 22, 2006): 61. http://dx.doi.org/10.11646/zootaxa.1209.1.3.
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One specimen of a keratose sponge not ascribable to any known Atlantic genus was collected by scuba diving from the shallow rocky sublittoral of El Hierro (Canary Islands). The sponge is irregularly massive and very hard in consistency, with a microconulose and unarmoured surface. The skeleton is formed by primary fibres cored with abundant foreign debris and a densely reticulate network of secondary fibres, which are strongly laminated and free of foreign debris. An irregular tertiary network formed by very thin fibres is also visible in some places. The features of the skeleton differ from those of any genus known from the Atlantic Ocean but match those of the genus Petrosaspongia Bergquist described from the Indo-Pacific and represented up to now by the species P. nigra. The Atlantic species, here described as Petrosaspongia pharmamari n. sp., differs from P. nigra by its external colour (dark brown instead of black), its consistency (a little more compressible), the greater width of the primary and secondary fibres, the higher proportion of primary fibres and the smaller diameter of meshes. The finding of a second species confirms the validity of the genus Petrosaspongia. This is the first confirmed record of the genus outside the type locality.
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Marchiori, José Newton Cardoso. "Anatomia da madeira e casca de Acacia velutina DC." Ciência e Natura 17, no. 17 (December 11, 1995): 99. http://dx.doi.org/10.5902/2179460x26534.
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The wood and bark of Acacia velutina DC. are described and compared with some other South-American species of the same genus. The presence of septa in fibres, the traumatic longitudinal channels and the 3-4 cells wide rays are the most important features of the wood structure. Phloematic fibres in the inner bark, the absence of chrystals in ray cells and their irregular course in the middle bark are important features in the anatomy of the bark.
12
John Hayden, W., and Sheila M. Hayden. "WOOD ANATOMY OF ACALYPHOIDEAE (EUPHORBIACEAE)." IAWA Journal 21, no. 2 (2000): 213–35. http://dx.doi.org/10.1163/22941932-90000246.
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Via LM and SEM, we studied wood structure of 51 genera representing 19 tribes of Acalyphoideae, the largest subfamily of Euphorbiaceae. Many acalyphoid woods possess the following features: growth rings indistinct or weakly defined; pores evenly distributed; simple perforation plates (but admixture of irregular scalariform plates common); alternate intervessel pits; vessel-ray pits larger than intervessel pits, circular to elongate and alternate to irregular; thin to moderately thick-walled non-septate fibre-tracheids or libriform wood fibres; parenchyma distribution diffuse, diffuse-in-aggregates, and scanty paratracheal, sometimes in thin-tangential bands; heterocellular rays seldom more than 3 cells wide; and prismatic crystals in parenchyma and /or ray cells. Within this syndrome, a number of other wood characters also occur but at lower frequency. For the most part, the unusual features have not proven systematically informative at the tribal level. Presence of lysigenous radial canals, however, supports recognition of tribe Alchorneae. Wood data do not support the segregation of Peraceae and Pandaceae from subfamily Acalyphoideae.
13
Kirsch, Schreiber, Dienes, Böttger, and Junginger. "Veränderungen der extrazellulären Matrix in der varikösen Venenwand." Vasa 28, no. 2 (May 1, 1999): 95–99. http://dx.doi.org/10.1024/0301-1526.28.2.95.
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Background: Investigation of changes in normal veins which result in the formation of varicosis led to examination of the histological organisation of the vessel wall and to histomorphological alterations in the region of the extracellular matrix. Patients and methods: The expression pattern of the matrix proteins collagen IV, fibronectin, laminin, tenascin, and undulin as well as the structure and orientation of elastic fibres were determined by means of immunohistochemical staining. Results: All varices exhibited an increased expression pattern in comparison to healthy veins. The venous vessel wall was often non-homogeneously enlarged. The intima was always more involved than the media and showed enhanced accumulation, whereas, the adventitia was not influenced by the pathological process. Collagen IV exhibited an early accumulation, especially in the subendothelial region. The other matrix proteins demonstrated an increase in fibre propagation parallel to the enlargement of the vessel wall. Essentially, an augmented de novo synthesis of fibres with an irregular arrangement and the formation of local plaques was found. Elastic fibres were enhanced by slight involvement of the vessel wall and were reduced and fragmented during increased involvement of the venous wall which explained the rigidity of varices in contrast to normal veins.
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Marchiori, José Newton Cardoso. "Anatomia da madeira e casca de Acacia tucumanensis Gris." Ciência e Natura 16, no. 16 (December 12, 1994): 85. http://dx.doi.org/10.5902/2179460x26498.
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The wood and bark anatomy of Acacia tucumanensis Gris. is described. Quantitative data from 33 different features of the secondary xylem are furnished, as well as photomicrographs and drawings of its structure. The presence of libriform fibres, simple perforation plates, paratracheal parenchyma and homogeneous rays, are important characteristics of the wood anatomy. The presence of septa in fibres and of rays with 3-4 cells wide, indicate the position of the species in the sub-genus Aculeiferum VassaI (= series Vulgares Benth.). Phloematic fibres in tangential bands, with 3-5 cells wide, and the irregular course of rays in the late bark, are the most conspicuous features of the bark structure. Photomicrographs of bark are also furnished.
15
Hamza, A. A., T. Z. N. Sokkar, M. A. El-Bakary, and A. M. Ali. "Interferometric determination of regular and/or irregular transverse sectional shape of homogeneous fibres." Measurement Science and Technology 13, no. 12 (November 4, 2002): 1931–36. http://dx.doi.org/10.1088/0957-0233/13/12/317.
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Hamza, A. A., T. Z. N. Sokkar, and M. A. Kabeel. "Interferometric determination of refractive indices and birefringence of fibres with irregular transverse sections." Journal of Physics D: Applied Physics 19, no. 2 (February 14, 1986): L19—L20. http://dx.doi.org/10.1088/0022-3727/19/2/001.
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Hamza, A. A., T. Z. N. Sokkar, and M. M. Shahin. "Interferometric determination of the optical properties of fibres with irregular transverse sections (Ramie)." Journal of Microscopy 137, no. 1 (January 1985): 85–92. http://dx.doi.org/10.1111/j.1365-2818.1985.tb02564.x.
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Marchiori, José Newton Cardoso. "Anatomia da madeira e casca da Bracatinga, Mimosa scabrella Benth." Ciência e Natura 17, no. 17 (December 11, 1995): 115. http://dx.doi.org/10.5902/2179460x26536.
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The general, macroscopic and microscopic features of the wood of Mimosa scabrella Benth. are described, as well as its bark anatomy. The wood and bark structure are compared with literature references. Vessels with simple perforation plates, alternate and vestured intervascular pitting, libriform fibres, homogeneous rays with procumbent cells and the conspicuous ripple marks in radial sections, are the most important features in this wood. Irregular groups of phloematic fibres in the inner bark, surrounded by chrystalliferous parenchyma strands, and the tangencial growing of rays in the middle bark, are the most important features observed in the bark.
19
Kulhavy, Petr, Martina Syrovatkova, Pavel Srb, Michal Petru, and Alzbeta Samkova. "Irregular Winding of Pre-preg Fibres Aimed at the Local Improvement of Flexural Properties." TEKSTILEC 60, no. 4 (December 5, 2017): 310–16. http://dx.doi.org/10.14502/tekstilec2017.60.310-316.
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Laksanawimol, Parichart, Praneet Damrongphol, and Maleeya Kruatrachue. "Alteration of the brood pouch morphology during gestation of male seahorses, Hippocampus kuda." Marine and Freshwater Research 57, no. 5 (2006): 497. http://dx.doi.org/10.1071/mf05112.
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The brood pouch of seahorses can be divided into four sequential stages based on the characteristics of the altered tissue layers during gestation: the normal stage, the embryo-carrying stage, the embryo-release stage and the repair stage. The brood pouch is composed of a folded inner pseudostratified columnar epithelium and a smooth outer stratified cuboidal epithelium. Three tissue layers between the inner and the outer epithelia are an inner loose connective tissue layer, a middle smooth muscle layer and an outer dense irregular connective tissue layer. In the normal stage, the inner loose connective tissue layer is thick and vascularised with small blood vessels; the muscle layer consists of scattered unorganised muscle fibres. In the embryo-carrying stage, the inner epithelial and inner loose connective tissue layers become distended and highly vascularised with enlarged blood vessels. In the embryo-release stage, the inner loose connective tissue layer is extensively vascularised with very large blood vessels and the smooth muscle fibres invade the outer dense irregular connective tissue layer. Structures altered during gestation gradually resume their normal condition in the repair stage. Extensive vascularisation of the brood pouch during gestation suggests an intricate paternal–embryo relationship implying other significant roles besides protective function of the pouch.
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Hinterleitner, S., M. Huber, R. Lackner, and W. Wieser. "Systemic and Enzymatic Responses to Endurance Training in Two Cyprinid Species with Different Life Styles (Teleostei: Cyprinidae)." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 1 (January 1, 1992): 110–15. http://dx.doi.org/10.1139/f92-013.
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Juveniles of the zooplanktivorous Danube bleak (Chalcalburnus chalcoides mento) and of the benthivorous nase (Chondrostoma nasus) were subjected to an endurance training regime for 81–90 d. Growth performance was better in trained than in untrained Danube bleak but not in nase. Mass specific heart size was significantly greater in trained than in untrained C. nasus, but no difference was found in C. chalcoides. The size of muscle fibres increased with training in both species; in nase the red and pink fibres and in Danube bleak the red and white fibres exhibited the most conspicuous response. Mass specific activities of the enzymes of energy metabolism were generally not affected by training, but in the white fibres of C. chalcoides, three glycolytic enzymes displayed a parallel trend indicating an increase of the glycolytic potential with training of about 25%. Since the Danube bleak maintains an irregular, burst-like mode of swimming even under the endurance training regime, we assume the lactate produced intermittently in the white muscles to be oxidized in the heart and the red muscles. The activities of three glycolytic heart enzymes were up to 25-fold higher in C. chalcoides than in C. nasus.
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Sharma, Babu Lal, R. Vijendra Rao, S. S. Bisen, and R. Dayal. "Modified Scalariform and Reticulate Perforation Plates in Species of Euodia (Rutaceae)." IAWA Journal 6, no. 1 (1985): 39–41. http://dx.doi.org/10.1163/22941932-90000906.
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Although there have been some reports of occurrence of scalariform and modified scalariform types of perforation in vessels of some members of the Rutaceae, no such observation has so far been made in the woods of Euodia species. In two species, E. elleryana and E. lunuankenda, besides the scalariform type, irregular and regular reticulate types of perforation have been observed. Additionally, silica bodies have also been noticed in vessels, fibres and axial parenchyma.
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Guan, Shian, Ayman S. Elmezayyen, Feifei Zhang, Jianming Zheng, and Chunye Xu. "Deterioration mechanism of electrochromic poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) thin films." Journal of Materials Chemistry C 4, no. 20 (2016): 4584–91. http://dx.doi.org/10.1039/c6tc00930a.
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Here we investigate the stability of poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDot-Me2) films via cycling 10 000 times in 0.1 M LiClO4/propylene carbonate (PC). And we find the morphology changed from a loose irregular network to compact structure with fibres covered by [ClO4]− and Li+ because of chemisorption and physisorption during cycling, the adsorbed ions decreased electroactive sites and blocked ion migration channels.
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Gryc, A., and T. Rzychoń. "Characterisation of Microstructure of We43 Magnesium Matrix Composites Reinforced with Carbon Fibres." Archives of Metallurgy and Materials 61, no. 2 (June 1, 2016): 1075–81. http://dx.doi.org/10.1515/amm-2016-0181.
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Abstract In the paper the microstructures of WE43 matrix composites reinforced with carbon fibres have been characterised. The influence of reinforcement type and T6 heat treatment (a solution treatment at 525°C for 8 h, a hot water quench and a subsequent ageing treatment at 250°C for 16 h) on microstructure have been evaluated. The light microscope and scanning electron microscope investigations have been carried out. No significant differences in samples reinforced with non-coated textiles have been reported. The substantial changes in sample reinforced with nickel-coated textile have been observed. The segregation of alloying elements to the matrix-reinforcement layer has been identified. The T6 heat treatment caused the appearance of disperse precipitates of β phase, but the process cannot be considered as satisfactory (irregular distribution, low volume fraction, relatively large size).
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Vesoulis, Z., Pars Ravichandran, Dimitri Agamanolis, and Duane Roe. "Elastofibromatous Polyp of the Sigmoid Colon - A Case Report and Review of Gastrointestinal Elastofibromas." Canadian Journal of Gastroenterology 17, no. 4 (2003): 275–77. http://dx.doi.org/10.1155/2003/917073.
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Elastofibromatous change in the gastrointestinal tract is a rarely reported, usually polypoid lesion of unknown etiology with submucosal stromal change that may mimic amyloid deposition. The constituent amorphous material of the polyp stroma has distinctive features that permit an accurate assessment and diagnosis including: distribution of the material predominantly in the submucosa; distinctive fibrillar and granular appearance of the deposits; thick, irregular, haphazardly arranged bundles of elastic fibres positive for Verhoeff’s elastic stain; ultrastructural fibres with an electron dense curvilinear or beaded appearance; lack of amyloid type vascular wall deposits; and lack of amyloid congophilia or crystal violet metachromasia.The clinical, light microscopic, histochemical and ultrastructural characteristics of this deposited material are reviewed in detail in the present report of a patient who presented with an asymptomatic polypoid lesion of the sigmoid colon. Other reported cases are summarized, and their clinical and pathological features are compared with the current case.
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Hamza, A. A., T. Z. N. Sokkar, and M. A. Kabeel. "Interferometric determination of optical properties of fibres with irregular transverse sections and having a skin-core structure." Journal of Physics D: Applied Physics 18, no. 12 (December 14, 1985): 2321–28. http://dx.doi.org/10.1088/0022-3727/18/12/003.
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Jian, F.-G., H.-B. Chu, G.-Z. Liu, J.-H. Zhao, Y.-B. Xu, T. Wang, H.-J. Sun, et al. "Morphological characteristics of the walls of thrombophlebitic saphenous vein." Phlebology: The Journal of Venous Disease 29, no. 3 (May 6, 2013): 164–70. http://dx.doi.org/10.1177/0268355512472135.
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Introduction: To investigate the morphological changes in the walls of thrombophlebitic saphenous veins. Methods: Fifty-four specimens were made into slices for haematoxylin and eosin and Masson trichrome staining; ultrathin slices were also created. Slices were observed under light microscopy and electron microscopy. Results: Under light microscopy, the tunica intima of venous wall in the thrombophlebitic saphenous veins group was obviously thickened and incomplete; intravascular papillary endothelial hyperplasia was observed. Hyperplasia of collagenous fibres in the tunica media was observed. Elastic fibres in the tunica externa became fewer, whereas nourishing vessels were significantly increased in number. Infiltration of many inflammatory cells was observed. Under electron microscopy, Auer bodies with high electron density and round granules could be seen in endothelial cells in the thrombophlebitic saphenous veins group. Smooth muscle cells had an irregular karyotype, with blurred cristae in some mitochondria. Myofilaments basically disappeared. Conclusion: Thrombus formation might aggravate re-modelling of the walls of varicose veins.
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Mehta, Anuj, Shalini Butola, Mayuresh Naik, Sangeeta Abrol, and Anju Kumari. "Intramuscular Cavernous Hemangioma of Medial Rectus Muscle in Paediatric Age Group." Case Reports in Ophthalmological Medicine 2017 (2017): 1–3. http://dx.doi.org/10.1155/2017/1076404.
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An 11-year-old male child presented with a mass on the nasal aspect of the right eye that has been there for the last 2 years. Extraocular movements were decreased in the right eye on levoversion, levoelevation, and levodepression. Local examination revealed a bluish mass with irregular surface and ill-defined margins located in the medial rectus muscle. The mass was 10 × 20 mm in size, firm, nodular, nontender, nonpulsatile, noncompressible, and nonreducible. MRI of the orbit revealed a well-defined mass of approximately 23 × 13 mm along the medial rectus (MR) muscle. It was hyperintense on T2W images with very minimal contrast enhancement. A provisional diagnosis of hemangioma or lymphangioma with intralesional haemorrhage was made. During surgical excision, the mass was found to be encapsulated by MR fibres. The MR fibres were separated, and the mass measuring 20 × 8 × 6.5 mm was removed and sent for histopathology. The histopathological examination revealed an intramuscular cavernous hemangioma.
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Schmitt, Uwe, Hans Georg Richter, and Bernd Wittke. "Fracture Morphology of Hickory (Carya Spp., Juglandaceae) Under Single-Blow Impact Loading." IAWA Journal 17, no. 2 (1996): 151–60. http://dx.doi.org/10.1163/22941932-90001445.
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Wood specimens of the true hickory group were tested for their shock resistance with the single blow impact method. From this test series 10 pieces with a uniform fracture mode, 'brash' and 'tough' , were selected for electron microscopy to examine the fracture mode of individual fibres in the tensile zone. 'Brash' specimens are characterized by well defined transverse or slightly oblique fracture lines across the entire cell wall, or a stepped-up course preferably within the secondary wall. Stepping-up mainly occurs along the interface between S1 and S2 layer or between primary wall and S1 layer. The smooth fracture of fibres in 'brash' specimens appears to be caused by compression-induced pre-slip planes which do not occur in 'tough' specimens. Individual fibres of 'tough' specimens mostly display a conspicuous and irregular zigzag course of the fracture line due to the tearing apart of fibrillar bundles . In addition, 'tough' specimens are characterised by the regular development of microcracks at a distance of up to several millimeters from the fracture plane. Such microcracks were not observed in 'brash' specimens. The described micro morphological differences between both fracture modes help to explain the considerable variation in shock resistance between specimens of similar density and gross wood structure.
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Castro, M. A., N. M. Apóstolo, and L. E. Navarro. "Bark anatomy of three indigenous conifers from southern South America." Australian Journal of Botany 54, no. 1 (2006): 73. http://dx.doi.org/10.1071/bt04065.
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This paper describes the bark anatomy of three native conifers from southern South America, Podocarpus nubigena Lindl., Saxegothaea conspicua Lindl. (Podocarpaceae) and Araucaria araucana (Mol.) K.Koch. (Araucariaceae). The bark colours of these three conifers are greyish-brown, reddish-brown and true brown, respectively. Morphologically, the bark of S. conspicua is scaly whereas it is fissured in A. araucana and P. nubigena. Fissures are relatively shallow in P. nubigena and relatively deep in A. araucana. The latter two species have elongated stripes and polygonal to irregular plates, respectively. Anatomically, P. nubigena shows a gradual transition between non-collapsed and collapsed phloem. This species shows secondary phloem cells regularly arranged in continuous tangential bands composed of alternating sieve cells, axial parenchyma and fibres. In A. araucana the ordered pattern observed in the non-collapsed secondary phloem is lost in the collapsed phloem. All three species show homocellular and uniseriate rays exhibiting a sinuous trajectory in the collapsed phloem and into the rhytidome. Fibres in P. nubigena are arranged in narrow, tangentially uniseriate lines. Sclereids are observed in S. conspicua whereas ramified sclereids and fibres are present in A. araucana. Minute cell-wall crystals in the fibres are exhibited in all species. The persistent rhytidome occupies a variable proportion of the bark. A. araucana shows thick periderms and rhytidome, with indistinct rays in dead phloem. Starch, tannins and resins are frequent in parenchyma. Secretory canals are present only in A. araucana. In summary, the external morphology, arrangement of axial parenchyma, type of the sclerenchymatous tissue, presence of secretory canals and cell-wall crystals are the most important features that can be used for identification when other diagnostic plant parts are missing.
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Hedberg-Oldfors, Carola, Robert Meyer, Kay Nolte, Yassir Abdul Rahim, Christopher Lindberg, Kristjan Karason, Inger Johanne Thuestad, et al. "Loss of supervillin causes myopathy with myofibrillar disorganization and autophagic vacuoles." Brain 143, no. 8 (August 1, 2020): 2406–20. http://dx.doi.org/10.1093/brain/awaa206.
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Abstract The muscle specific isoform of the supervillin protein (SV2), encoded by the SVIL gene, is a large sarcolemmal myosin II- and F-actin-binding protein. Supervillin (SV2) binds and co-localizes with costameric dystrophin and binds nebulin, potentially attaching the sarcolemma to myofibrillar Z-lines. Despite its important role in muscle cell physiology suggested by various in vitro studies, there are so far no reports of any human disease caused by SVIL mutations. We here report four patients from two unrelated, consanguineous families with a childhood/adolescence onset of a myopathy associated with homozygous loss-of-function mutations in SVIL. Wide neck, anteverted shoulders and prominent trapezius muscles together with variable contractures were characteristic features. All patients showed increased levels of serum creatine kinase but no or minor muscle weakness. Mild cardiac manifestations were observed. Muscle biopsies showed complete loss of large supervillin isoforms in muscle fibres by western blot and immunohistochemical analyses. Light and electron microscopic investigations revealed a structural myopathy with numerous lobulated muscle fibres and considerable myofibrillar alterations with a coarse and irregular intermyofibrillar network. Autophagic vacuoles, as well as frequent and extensive deposits of lipoproteins, including immature lipofuscin, were observed. Several sarcolemma-associated proteins, including dystrophin and sarcoglycans, were partially mis-localized. The results demonstrate the importance of the supervillin (SV2) protein for the structural integrity of muscle fibres in humans and show that recessive loss-of-function mutations in SVIL cause a distinctive and novel myopathy.
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Marcati, Carmen Regina, Leandro Roberto Longo, Alex Wiedenhoeft, and Claudia Franca Barros. "Comparative wood anatomy of root and stem of Citharexylum myrianthum (Verbenaceae)." Rodriguésia 65, no. 3 (September 2014): 567–76. http://dx.doi.org/10.1590/2175-7860201465301.
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Root and stem wood anatomy of C. myrianthum (Verbenaceae) from a semideciduous seasonal forest in Botucatu municipality (22º52’20”S and 48º26’37”W), São Paulo state, Brazil, were studied. Growth increments demarcated by semi-ring porosity and marginal bands of axial parenchyma were observed in the wood of both root and stem. Many qualitative features were the same in both root and stem: fine helical thickenings, and simple and multiple perforation plates in vessel elements; large quantities of axial parenchyma in the growth rings, grading from marginal bands and confluent forming irregular bands in earlywood to lozenge aliform in latewood; axial parenchyma cells forked, and varied wall projections and undulations; septate fibres; forked and diverse fibre endings. Quantitative features differing between root and stem wood were evaluated using student’s t-test, and vessel frequency, vessel element length, vessel diameter, ray height, and vulnerability and mesomorphy indices differed significantly. Root wood had lower frequency of vessels, narrower and longer vessel elements, and taller rays than wood of the stem. The calculated vulnerability and mesomorphy indices indicated that C. myrianthum plants are mesomorphic. Roots seem to be more susceptible to water stress than the stem.
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Heklau, Heike, Peter Gasson, Fritz Schweingruber, and Pieter Baas. "Wood Anatomy of Chenopodiaceae (Amaranthaceae s.l.)." IAWA Journal 33, no. 2 (2012): 205–32. http://dx.doi.org/10.1163/22941932-90000090.
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The wood anatomy of the Chenopodiaceae is distinctive and fairly uniform. The secondary xylem is characterised by relatively narrow vessels (<100 μm) with mostly minute pits (<4 μm), and extremely narrow vessels (<10 μm intergrading with vascular tracheids in addition to “normal” vessels), short vessel elements (<270 μm), successive cambia, included phloem, thick-walled or very thick-walled fibres, which are short (<470 μm), and abundant calcium oxalate crystals. Rays are mainly observed in the tribes Atripliceae, Beteae, Camphorosmeae, Chenopodieae, Hablitzieae and Salsoleae, while many Chenopodiaceae are rayless. The Chenopodiaceae differ from the more tropical and subtropical Amaranthaceae s.str. especially in their shorter libriform fibres and narrower vessels. Contrary to the accepted view that the subfamily Polycnemoideae lacks anomalous thickening, we found irregular successive cambia and included phloem. They are limited to long-lived roots and stem borne roots of perennials (Nitrophila mohavensis) and to a hemicryptophyte (Polycnemum fontanesii). The Chenopodiaceae often grow in extreme habitats, and this is reflected by their wood anatomy. Among the annual species, halophytes have narrower vessels than xeric species of steppes and prairies, and than species of nitrophile ruderal sites.
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Xinying, Zhang, Pieter Baas, and Alberta M. W. Mennega. "Wood Anatomy of Bhesa Sinica (Celastraceae)." IAWA Journal 11, no. 1 (1990): 57–60. http://dx.doi.org/10.1163/22941932-90001144.
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The wood anatomy of Bhesa sinica (Chang ' Liang) Chang ' Liang, the only species of the genus occurring in China, is described in detail and compared with other Celastraceae. Bhesa sinica closely resembles other species of the genus, in e. g. vessels mainly in radial multiples, exclusively scalariform perforations, large and (almost) simple vessel-ray pits; parenchyma in fine irregular bands, in long (over 8-celled) strands; thick-walled, non septate libriform fibres; 1-5-seriate heterocellular rays, and prismatic crystals in chambered axial and ray parenchyma cells. This combination of characters is not known to occur in any of the other genera of the Celastraceae, and most individual wood anatomical character states of Bhesa are also unusual within the family. The isolated position of the genus in the Celastraceae is discussed.
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Hamza, A. A., T. Z. N. Sokkar, M. A. El-Bakary, and A. M. Ali. "An interferometric method for studying the influence of temperature on the mean refractive indices and cross-sectional area of irregular fibres." Polymer Testing 22, no. 1 (February 2003): 83–91. http://dx.doi.org/10.1016/s0142-9418(02)00053-3.
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Semisch, M., E. Hagert, M. Garcia-Elias, A. Lluch, and S. Rein. "Histological assessment of the triangular fibrocartilage complex." Journal of Hand Surgery (European Volume) 41, no. 5 (December 18, 2015): 527–33. http://dx.doi.org/10.1177/1753193415618391.
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The morphological structure of the seven components of triangular fibrocartilage complexes of 11 cadaver wrists of elderly people was assessed microscopically, after staining with Hematoxylin-Eosin and Elastica van Gieson. The articular disc consisted of tight interlaced fibrocartilage without blood vessels except in its ulnar part. Volar and dorsal radioulnar ligaments showed densely parallel collagen bundles. The subsheath of the extensor carpi ulnaris muscle, the ulnotriquetral and ulnolunate ligament showed mainly mixed tight and loose parallel tissue. The ulnolunate ligament contained tighter parallel collagen bundles and clearly less elastic fibres than the ulnotriquetral ligament. The ulnocarpal meniscoid had an irregular morphological composition and loose connective tissue predominated. The structure of the articular disc indicates a buffering function. The tight structure of radioulnar and ulnolunate ligaments reflects a central stabilizing role, whereas the ulnotriquetral ligament and ulnocarpal meniscoid have less stabilizing functions.
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Pacella, Alessandro, Paolo Ballirano, Marzia Fantauzzi, Antonella Rossi, Cecilia Viti, Lorenzo Arrizza, Elisa Nardi, Raffaela Caprioli, and Maria Rita Montereali. "Surface and Bulk Modifications of Fibrous Erionite in Mimicked Gamble’s Solution at Acidic pH." Minerals 11, no. 9 (August 24, 2021): 914. http://dx.doi.org/10.3390/min11090914.
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This study aimed at investigating both the surface and bulk modifications occurring on fibrous erionite during leaching in a mimicked Gamble’s solution (MGS) at pH of 4.5 and T = 37 °C, up to one month of incubation. Samples were characterized by a multi-analytical approach: field-emission scanning electron microscopy (FE-SEM) was employed to investigate the morphological changes of both pristine and reacted fibres, inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of the released cations; X-ray photoelectron spectroscopy (XPS) was exploited for highlighting possible modifications of surface chemistry; X-ray powder diffraction (XRPD) and high-resolution transmission electron microscopy (HR-TEM) were applied aiming to get information on the structural state of the fibres following the incubation. ICP results integrated with those obtained by both bulk- and surface-chemical characterization highlighted that erionite binds Na especially in the first 24 h of sample incubation in the MGS, following ion exchange with the extra framework cations, in particular Ca. Moreover, our new results show that the Na binding process caused structural modifications with the migration of Na toward the Ca2 site and redistribution of the cations within the erionite cage. TEM investigation pointed out that the interaction between erionite and MGS results in the formation of a new surface amorphous layer with an irregular lobate pattern on an earlier surface weathered layer. However, the silicate framework is not weakened by incubation in the MGS at acidic pH. In addition, on the basis of the Si release normalized to the mineral surface area, fibrous erionite resulted significantly more biodurable than amphibole asbestos. Notably, considering the primary role played by biodurability in inducing pathogenicity, this result certainly supports in vivo observations showing that erionite is much more tumorigenic than asbestos. Moreover, the ions released by erionite when immersed in MGS may trigger biological effects, such as those on lipid packing and membrane permeability. On this basis, we expect a regulatory definition that would provide protection from this carcinogenic fibre.
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Cevallos-Ferriz, Sergio R. S., and Ruth A. Stockey. "Vegetative Remains of the Rosaceae from the Princeton Chert (Middle Eocene) of British Columbia." IAWA Journal 11, no. 3 (1990): 261–80. http://dx.doi.org/10.1163/22941932-90001183.
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Several anatomieally preserved twigs, a branehing speeimen and the wood of a large axis with affinities to Rosaeeae are deseribed from the Prineeton ehert (Middle Eoeene) of British Columbia, Canada. Speeimens are eharaeterised by a heteroeellular pith with a peri-medullary rone of thiek-walled oval eells and semi-ring-porous seeondary xylem with vertieal traumatie duets, fibres with eireular bordered pits, and mostly seanty paratracheal and oeeasionally apotracheal parenehyma. Ray to vessel pitting is similar to the alternate intervaseular pitting. Seeondary phloem is eomposed of tangentially oriented diseontinuous bands of alternating fibres and thinwalled eells. Seeondary eortical tissues are represented by a phelloderm eharaeterised by rectangular eells and phellern with rectangular eoneave eells. Anatomical variation between speeimens can be related to age of the woody axes. Juvenile and mature wood of this speeies differ in vessel arrangement and presenee of scanty paratracheal parenchyma in mature wood. Vessel elements are arranged in radial multiples, oeeasional clusters as well as solitary vessels. Tyloses and dark cellular contents are present mainly in mature wood. Some twigs have a heterocellular pith with a few scattered cells with dark contents or, occasionally, short irregular rows of these cells. In the branching specimen eells of this type also are organised in longer rows. Together, these anatomical features suggest that all specimens belong to the same taxon, Prunus allenbyensis Cevallos-Ferriz ' Stockey n. sp. Anatomy of this plant reinforces the interpretation of a subtropical to temperate climate during the time of deposition.
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Cardone, Franco, Achim Thomzig, Walter Schulz-Schaeffer, Angelina Valanzano, Marco Sbriccoli, Hanin Abdel-Haq, Silvia Graziano, et al. "PrPTSE in muscle-associated lymphatic tissue during the preclinical stage of mice infected orally with bovine spongiform encephalopathy." Journal of General Virology 90, no. 10 (October 1, 2009): 2563–68. http://dx.doi.org/10.1099/vir.0.010801-0.
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The involvement of muscles in the pathogenesis of transmissible spongiform encephalopathies (TSEs) is irregular and unpredictable. We show that the TSE-specific protein (PrPTSE) is present in muscles of mice fed with a mouse-adapted strain of bovine spongiform encephalopathy as early as 100 days post-infection, corresponding to about one-third of the incubation period. The proportion of mice with PrPTSE-positive muscles and the number of muscles involved increased as infection progressed, but never attained more than a limited distribution, even at the clinical stage of disease. The appearance of PrPTSE in muscles during the preclinical stage of disease was probably due to the haematogenous/lymphatic spread of infectivity from the gastrointestinal tract to lymphatic tissues associated with muscles, whereas in symptomatic animals, the presence of PrPTSE in the nervous system, in neuromuscular junctions and in muscle fibres suggests a centrifugal spread from the central nervous system, as already observed in other TSE models.
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SBERNARDORI, M. C., and P. BANDIERA. "Histopathology of the A1 Pulley in Adult Trigger Fingers." Journal of Hand Surgery (European Volume) 32, no. 5 (October 2007): 556–59. http://dx.doi.org/10.1016/j.jhse.2007.06.002.
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The histopathology of the central parts of 40 A1 pulleys from adult patients with primary trigger fingers was studied using light and transmission electron microscopes and the findings were compared with those in a control series of 10 normal A1 pulleys. The evaluation of the normal A1 pulley revealed a bi-laminar structure. The deepest layer was composed of dense normal connective tissue. The outermost layer was formed by loose connective tissue. In trigger digits, it was possible to identify a tri-laminar structure. The deepest layer was composed of irregular connective tissue, formed by small collagen fibres and abundant extracellular matrix. A considerable amount of chondroid-metaplasia was present in this layer. The middle layer contained dense, normal connective tissue with some fibrocytes. The outermost layer was formed of loose connective tissue. In conclusion, there was an additional layer in the A1 pulley in pathological cases which was not present in normal pulleys.
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Mennega, Alberta M. W. "Wood Anatomy of the Hippocrateoideae (Celastraceae)." IAWA Journal 18, no. 4 (1997): 331–68. http://dx.doi.org/10.1163/22941932-90001501.
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In this paper the wood anatomy of the subfarnily Hippocrateoideae of the Celastraceae is treated. Halle's division (1986, 1990) of the subfarnily into four tribes, chiefly based on material of tropical Africa: viz. Salacieae, Campylostemoneae, Helictonemeae and Hippocrateae is followed. In a recent issue of the Flora of the Guianas the Hippocrateaceae - there treated as aseparate farnily - were divided into Hippocrateoideae and Salacioideae. This bipartition was reflected in the wood structure of the genera studied (Mennega 1994). Here the wood structure of all genera worldwide (24), except the Asian genus Arnicratea, is described. It appeared that again a subdivision into two distinct anatomical groups could be made, with the three last tribes mentioned above showing the same characteristic structure as found before in New World Hippocrateae/Hippocrateoideae. The most important features of this group are the presence of very wide and very high rays, in a number of genera with unlignified ray cells at the growth ring border, the absence of included phloem tissue, and in many species an intruding bark resulting in an indented wood pattern in stern cross sections or even an intricate pattern of deep furrows. The Salacieae/Salacioideae on the other hand are characterized by narrow, not exceptionally high rays, absence of unlignified ray cells, the occurrence of septate fibres in a parenchyma-like distribution, and often by the presence of included phloem tissue, either as isolated strands or more often as conspicuous concentric bands, or as irregular bands with radial connections. Features present in all genera are: vessels with simple perforation plates, preponderance of solitary vessels, wide and narrow vessels distributed at random, alternate pitting; fibretracheids, and libriform nonseptate and septate fibres present; axial parenchyma scanty paratracheal or as rare isolated strands; rays heterogeneous, the cell types irregularly distributed, rhombic crystals numerous, often in characteristic radial distribution. Campylostemon, considered in the past by some taxonornists as belonging in Celastraceae or as intermediate between Hippocrateaceae and Celastraceae, closely resembles Hippocrateae in its wood anatomy. And it is especially this group that by its characteristic features -like the wide rays - is more different from Celastraceae in general than Salacieae, which have several features in common with genera of Celastraceae.
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Alrawi, Reem A., Nik Norulaini Nik Ab Rahman, Anees Ahmad, Norli Ismail, and A. K. Mohd Omar. "Characterization of Oily and Non-Oily Natural Sediments in Palm Oil Mill Effluent." Journal of Chemistry 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/298958.
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Palm oil is one of the many vegetable oils widely consumed around the world. The production of palm oil requires voluminous amount of water with the concurrent generation of large amount of wastewater known as palm oil mill effluent (POME). POME is a mixture of water, oil, and natural sediments (solid particles and fibres).There is a dearth of information on the physical properties of these POME sediments. This study intends to distinguish the physical properties of oily and non-oily POME sediments which include sediment size, particle size distribution (PSD), sediment shape, sediment surface morphology, and sediment density. These characterizations are important for future researches because these properties have significant effects on the settling process that occurs either under natural gravity or by coagulations. It was found that the oily and non-oily POME sediments have different sizes with nonspherical irregular shapes, and because of that, the aspect ratio (AR) and circularity shape factors were adopted to describe the shapes of these sediments. The results also indicate that the density of oily POME sediment decreases as the sediment size increases.
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Quilhó, Teresa, Helena Pereira, and Hans Georg Richter. "Variability of Bark Structure in Plantation-Grown Eucalyptus Globulus." IAWA Journal 20, no. 2 (1999): 171–80. http://dx.doi.org/10.1163/22941932-90000677.
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The bark structure of Eucalyptus globulus Labill. grown in plantations in Central Portugal is described, based on specimens extracted at six height levels from ten 15-year-old trees. No significant variation of qualitative features between trees was observed. The non-collapsed phloem is characterised by multiseriate tangential rows of phloem parenchyma alternating with rows of phloem fibres, interspersed with large sieve tubes and their respective companion cells, and uniseriate rays . With the onset of sieve tube collapse (collapsed phloem ), some parenchyma cells expand and sclerify, the course of rays becomes irregular, and ray dilatation is initiated. The periderm is composed of a phellem of lignified cells with horseshoe thickening (phelloids), followed by a layer of cells with suberised tangential walls, and a phelloderm with a variable number of layers of thin-walled cells. Age-related secondary changes give rise to a specific within-tree pattern of axial variation. Both the intensity of sclerification of phloem parenchyma cells and the degree of ray dilatation increase with tree age.
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Dos Santos, Gracielza, and Regis B. Miller. "Wood Anatomy of Jacaranda (Bignoniaceae): Systematic Relationships in Sections Monolobos and Dilobos as Suggested by Twig and Stem Wood Rays." IAWA Journal 18, no. 4 (1997): 369–83. http://dx.doi.org/10.1163/22941932-90001502.
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This report provides a generic description of the stern wood anatomy of 15 species of Jacaranda from seetions Monolobos and Dilobos. In Monolobos (excluding J. copaia), the rays are homocellular and exclusively uniseriate, occasionally with a small biseriate portion. In Dilobos, the rays are heterocellular and 2-3(-4) cells wide. To verify the differences in ray structure, 27 species of twig specimens were examined and compared with stern specimens of the same seetion. The wood anatomy corroborates morphological evidence that suggests partitioning of Jacaranda into two distinct seetions and supports the hypothesis that section Dilobos is primitive. The wood anatomy of Jacaranda copaia is distinct from that of other species in the genus. The vessels are larger in diameter and fewer per square millimetre, the vessel elements and fibres are longer, and the number of cells per parenchyma strand is higher. In addition, the rays are fewer per millimetre, taller, and homocellular to slightly heterocellular, with one irregular row of square cells, 2-3(-4) cells wide. Jacaranda copaia seems to be intermediate between seetions Monolobos and Dilobos.
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Büyükkartal, Hatice, Ahmet Kahraman, Hatice Çölgeçen, Musa Doğan, and Ersin Karabacak. "Mericarp micromorphology and anatomy of Salvia hedgeana Dönmez, S. huberi Hedge and S. rosifolia Sm. (section Salvia Hedge, Lamiaceae)." Acta Botanica Croatica 70, no. 1 (January 1, 2011): 65–80. http://dx.doi.org/10.2478/v10184-010-0011-8.
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Mericarp micromorphology and anatomy ofSalvia hedgeanaDönmez,S. huberiHedge andS. rosifoliaSm. (sectionSalviaHedge, Lamiaceae)Mericarp (nutlet) micromorphology and pericarp structure of three morphologically similar endemicSalviaspecies;Salvia hedgeana, S. huberiandS. rosifoliawere investigated using LM, SEM and TEM.Salvia hedgeanahas larger mericarps and abscission scars thanS. huberiandS. rosifolia. Mericarp length to width ratio ranges from 1.11 inS. hedgeanato 1.60 inS. huberi. Mericarp shape is mainly ovoid, rarely broadly ovoid inS. hedgeana, and oblong inS. huberi. The mericarp surface sculpturing pattern in all species is colliculate. However, exocarp cells are pentangular-hexangular inS. hedgeana, irregular inS. huberiand rounded and smaller inS. rosifolia. InSalvia huberianticlinal walls are undulate whereas inS. hedgeanaandS. rosifoliaanticlinal walls are straight.Salvia hedgeanawas distinguished from the others by the thickest pericarp (146-185 μm). The sclerenchymatous region significantly varied between the species. It was 84-99 μm inS. hedgeana, 56-82 μm inS. huberiand 27-61 μm inS. rosifolia. The mesocarp was also thicker inS. hedgeana. The wetted mericarps produced mucilage, butS. huberidiffered from the others in having translucent-milky white opaque mucilage with fibres or radiating cordons.
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Kundalić, Braca, Slađana Ugrenović, Ivan Jovanović, Natalija Stefanović, Vladimir Petrović, Jasen Kundalić, Miljana Pavlović, and Vladimir Antić. "Analysis of Fascicular Structure and Connective Tissue Sheaths in Sural Nerve during Aging." Acta Facultatis Medicae Naissensis 31, no. 2 (June 26, 2014): 113–20. http://dx.doi.org/10.2478/afmnai-2014-0013.
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Summary The aim of our study was to analyze the changes of connective tissue sheaths of epi-, peri- and endoneurium of sural nerve during aging. The study was conducted on sural nerve samples of 10 cases aged 9-80 years. The specimens were embedded in paraffin using standard procedures, after which 5-μm-thick cross-sections of nerve trunks were made and stained using Masson’s trichrome staining. After morphological analysis of fascicular structure and connective sheaths of the nerve, morphometric analysis was conducted using the software for digital image analysis “ImageJ”. Each investigated case was analyzed for total neural, epineurial and fascicular cross-section area, mean values of perineurial index, volume density of myelinated axons and of endoneurial content. To test the difference in mean values for statistical significance we used the Student’s T-test for small independent sample. The number of fascicles was 5-13, while the majority of the nerves had less than 10 fascicles. Fascicular structure, which included the number of fascicles and epifascicular/fascicular area ratio, did not show significant changes during aging. Perineurial thickness /fascicle size ratio statistically significantly increased in the older investigated group (p<0.05). Myelinated fibres were of smaller diameter, with more irregular form and markedly less frequent in older cases. Quantitative analysis showed statistically significant decrease in volume density of myelinated fibres in the older group. As results of applied investigation methods we found thickening of perineurial sheath of sural nerve during aging, as well as endoneurial fibrosis. Future investigations of age-related changes should focus on analysis of the components of extracellular matrix within perineurium and endoneurium.
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Kampf, A. R., J. Plášil, A. V. Kasatkin, and J. Marty. "Belakovskiite, Na7(UO2)(SO4)4(SO3OH)(H2O)3, a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah, USA." Mineralogical Magazine 78, no. 3 (June 2014): 639–49. http://dx.doi.org/10.1180/minmag.2014.078.3.12.
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AbstractThe new mineral belakovskiite (IMA2013-075), Na7(UO2)(SO4)4(SO3OH)(H2O)3, was found in the Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary alteration phase in association with blödite, ferrinatrite, kröhnkite, meisserite and metavoltine. Crystals of belakovskiite are very pale yellowish-green hair-like fibres up to 2 mm long and usually no more than a few mm in diameter. The fibres are elongated on [100] and slightly flattened on {021}. Crystals are transparent with a vitreous lustre. The mineral has a white streak and a probable Mohs hardness of ∼2. Fibres are flexible and elastic, with brittle failure and irregular fracture. No cleavage was observed. The mineral is readily soluble in cold H2O. The calculated density is 2.953 g cm−3. Optically, belakovskiite is biaxial (+) with α = 1.500(1), β = 1.511(1) and γ = 1.523(1) (measured in white light). The measured 2V is 87.1(6)° and the calculated 2V is 88°. The mineral is non-pleochroic. The partially determined optical orientation is X ≈ a. Electron-microprobe analysis provided Na2O 21.67, UO3 30.48, SO3 40.86, H2O 6.45 (structure), total 99.46 wt.% yielding the empirical formula Na6.83(U1.04O2)(SO4)4(S0.99O3OH)(H2O)3 based on 25 O a.p.f.u. Belakovskiite is triclinic, P, with a = 5.4581(3), b = 11.3288(6), c = 18.4163(13) Å, α = 104.786(7)°, β = 90.092(6)°, γ = 96.767(7)°, V = 1092.76(11) Å3 and Z = 2. The eight strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 8.96(35)(002), 8.46(29)(011), 5.19(100)(01,101,10), 4.66(58)(013,02,0,110), 3.568(37)(120,023,005,03), 3.057(59)(06,15,31), 2.930(27)(multiple) and 1.8320(29)(multiple). The structure, refined to R1 = 5.39% for 3163 Fo > 4σF reflections, contains [(UO2)(SO4)4(H2O)]6− polyhedral clusters connected via an extensive network of Na−O bonds and H bonds involving eight Na sites, three other H2O sites and an SO3OH (hydrosulfate) group. The 3-D framework, thus defined, is unique among known uranyl sulfate structures. The mineral is named for Dmitry Ilych Belakovskiy, a prominent Russian mineralogist and Curator of the Fersman Mineralogical Museum.
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Kampf, A. R., B. P. Nash, M. Dini, and A. A. Molina Donoso. "Torrecillasite, Na(As,Sb)43+O6Cl, a new mineral from the Torrecillas mine, Iquique Province, Chile: description and crystal structure." Mineralogical Magazine 78, no. 3 (June 2014): 747–55. http://dx.doi.org/10.1180/minmag.2014.078.3.20.
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AbstractThe new mineral torrecillasite (IMA2013-112), Na(As,Sb)43+O6Cl, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, cinnabar, gypsum, halite, lavendulan, magnesiokoritnigite, marcasite, quartz, pyrite, scorodite, wendwilsonite and other potentially new As-bearing minerals. Torrecillasite occurs as thin colourless prisms up to 0.4 mm long in jack-straw aggregates, as very thin fibres in puff balls and as massive intergrowths of needles. Prisms are elongated on [100] with diamond-shaped cross-section and irregular terminations. Crystals are transparent, with adamantine lustre and white streak. The Mohs hardness is 2½, tenacity is brittle and fracture is irregular. Cleavage on (001) is likely. The calculated density is 4.056 g cm−3. Optically, torrecillasite is biaxial (−) with α = 1.800(5), β = 1.96(1), γ = 2.03(calc.) (measured in white light). The measured 2V is 62.1(5)°, no dispersion or pleochroism were observed, the optical orientation isX=c,Y=b,Z=a. The mineral is very slowly soluble in H2O, slowly soluble in dilute HCl and rapidly soluble in concentrated HCl. The empirical formula, determined from electron-microprobe analyses, is (Na1.03Mg0.02)∑1.05(As3.39Sb0.62)∑4.01O6.07Cl0.93. Torrecillasite is orthorhombic,Pmcn, a= 5.2580(9),b= 8.0620(13),c= 18.654(3) Å,V= 790.7(2) Å3andZ= 4. The eight strongest X-ray powder diffraction lines are [dobsÅ(I)(hkl)]: 4.298(33)(111), 4.031(78)(014,020), 3.035(100)(024,122), 2.853(39)(115,123), 2.642(84)(124,200), 2.426(34)(125), 1.8963(32)(225) and 1.8026(29)(0·1·10,233). The structure, refined toR1= 4.06% for 814Fo>4σFreflections, contains a neutral, wavy As2O3layer parallel to (001) consisting of As3+O3pyramids that share O atoms to form six-membered rings. Successive layers are flipped relative to one another and successive interlayer regions contain alternately either Na or Cl atoms. Torrecillasite is isostructural with synthetic orthorhombic NaAs4O6Br.
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Cranford, Steven W. "Increasing silk fibre strength through heterogeneity of bundled fibrils." Journal of The Royal Society Interface 10, no. 82 (May 6, 2013): 20130148. http://dx.doi.org/10.1098/rsif.2013.0148.
Full textAbstract:
Can naturally arising disorder in biological materials be beneficial? Materials scientists are continuously attempting to replicate the exemplary performance of materials such as spider silk, with detailed techniques and assembly procedures. At the same time, a spider does not precisely machine silk—imaging indicates that its fibrils are heterogeneous and irregular in cross section. While past investigations either focused on the building material (e.g. the molecular scale protein sequence and behaviour) or on the ultimate structural component (e.g. silk threads and spider webs), the bundled structure of fibrils that compose spider threads has been frequently overlooked. Herein, I exploit a molecular dynamics-based coarse-grain model to construct a fully three-dimensional fibril bundle, with a length on the order of micrometres. I probe the mechanical behaviour of bundled silk fibrils with variable density of heterogenic protrusions or globules, ranging from ideally homogeneous to a saturated distribution. Subject to stretching, the model indicates that cooperativity is enhanced by contact through low-force deformation and shear ‘locking’ between globules, increasing shear stress transfer by up to 200 per cent. In effect, introduction of a random and disordered structure can serve to improve mechanical performance. Moreover, addition of globules allows a tuning of free volume, and thus the wettability of silk (with implications for supercontraction) . These findings support the ability of silk to maintain near-molecular-level strength at the scale of silk threads, and the mechanism could be easily adopted as a strategy for synthetic fibres.
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Lysakowski, A., L. B. Minor, C. Fernandez, and J. M. Goldberg. "Physiological identification of morphologically distinct afferent classes innervating the cristae ampullares of the squirrel monkey." Journal of Neurophysiology 73, no. 3 (March 1, 1995): 1270–81. http://dx.doi.org/10.1152/jn.1995.73.3.1270.
Full textAbstract:
1. Semicircular-canal afferents in the squirrel monkey were characterized by their resting discharge, discharge regularity, sensitivity to galvanic currents delivered to the ear (beta *), the gain (g2Hz), and phase lead (phi 2Hz) of their response to 2-Hz sinusoidal head rotations, and their antidromic conduction velocity. Discharge regularity was measured by a normalized coefficient of variation (CV*); the higher the CV*, the more irregular the discharge. g2Hz and phi 2Hz were expressed relative to angular head velocity. 2. These physiological measures were used in an attempt to discern the discharge properties of the three morphological classes of afferents innervating the crista. Presumed bouton (B) fibers were identified as slowly conducting afferents. Presumed calyx (C) fibers were recognized by their irregular discharge and low rotational gains. The remaining fibers were considered to be dimorphic (D) units. Single letters (B, C, and D) are used to emphasize that the classification is based on circumstantial evidence and may be wrong for individual fibers. Of the 125 identified fibers, 13 (10%) were B units, 36 (29%) were C units, and 76 (61%) were D units. 3. B units were regularly discharging D units ranged from regularly to irregularly discharging. C units were the most irregularly discharging afferents encountered. The mean resting discharge for the entire sample was 74 spikes/s. Resting rates were similar for regularly discharging B and D units and higher than those for irregularly discharging C and D units. 4. Except for their lower conduction velocities, the discharge properties of B units are indistinguishable from those of regularly discharging D units. Many of the discharge properties of B and D units vary with discharge regularity. There is a strong, positive relation when beta *, g2Hz, or phi 2Hz is plotted against CV*. For beta * or phi 2Hz, C units conform to the relation for B and D units. In contrast, values of g2Hz for C units are three to four times lower than predicted from the relation for the other two classes. 5. Internal (axon) diameters (dp) of peripheral vestibular-nerve fibers were estimated from central antidromic conduction velocities. Thick fibers (dp > or = 49 microns) were irregularly discharging, mostly C units. Medium-sized fibers (dp = 1.5-4 microns) included regular, intermediate, and irregular D units, as well as C units. Thin fibers (dp < or = 1.5 microns) were defined as B units.(ABSTRACT TRUNCATED AT 400 WORDS)