Coarse Fibrils Research Articles

Separator structural-chemical features dependency on lithium-ion battery performances

Rechargeable lithium-ion batteries (LIBs) increasingly attract emphasis. Porous construction evolutions during LIBs operation inevitably deteriorate separators mechanical and electrochemical performances. In this research, separators with serial porous constructions are prepared accurately to reveal the dependency mechanism of separator porous structure design on LIB performances. Porous structure analyses, mechanical properties, orientation parameters, and thermal stability diagnosis verify uniform drawing deformations of casting films centralize pore size, optimize pore channel linearity, and retain isotropic texture. Heterogeneous pores with coarse fibrils emphasize under asynchronous drawing, causing worse permeability and anisotropic features, which likely suffered from potential safety hazards caused by excessive unidirectional shrinkage. Electrochemical and battery performance measurements uncover that concentrated pores with superior connectivity determine homogeneous Li+ fluxes, uniformly expand electrodes to impose even compressive stress on separators, and thus reserve initial porous structure maximally to ensure cycling stability. Heterogeneous Li+ fluxes derived from uneven pores with inferior connectivity cause excessive local compression stress on separators. Consequently, mechanically deteriorated porous structure highlight, in reverse impedes Li+ transfer and worsens cell performances. This study suggests separator structural-chemical features function in ensuring LIB performances, which lays solid foundations for separator industrial manufacturing with suitable porous structures for LIBs.

Novel preparation of lithium‐ion battery wet‐processed separator based on the synergistic effect of porous skeleton nano‐Al2O3in situ blending and synchro‐draw

AbstractRoutine lithium‐ion battery separators with uneven micropores and poor electrolyte affinity raise ion transport barriers and become the battery‐performance‐limiting factors. A wet‐processed separator with homogeneous porous structure and porous skeleton nano‐Al2O3 in situ blending is readily prepared by thermally induced phase separation of paraffin, nano‐Al2O3 and ultra‐high molecular weight polyethylene (UHMWPE) in this work. SEM, ImageJ statistical analysis, porosity and Gurley calculation show that a separator that has undergone asynchronous drawing exhibits ample sturdy fibrils, heterogeneous pore size dispersion, poor permeability and strong anisotropy. However, UHMWPE deforms much more uniformly under a synchro‐draw, which distinctly lessens coarse fibrils, centralizes porous construction after stretching and brings better isotropy for the separator. Additionally, nano‐Al2O3 scattered in the cast film further weakens the heterogeneity of micropores stemming from the uneven thermally induced phase separation. Wettability tests and thermal diagnoses also show that nano‐Al2O3 on the porous skeleton strengthens the thermal stability and electrolyte affinity of the separator. Consequently, batteries containing nano‐Al2O3 composite separators show much higher electrochemical stability, ionic conductivity and Li+ transport number because of the synergistic effect of the even microvoids and nano‐Al2O3 on the porous skeleton, which expedites Li+ transport and endows superior lithium‐ion battery performance. © 2022 Society of Industrial Chemistry.

Low-Cost Mass Manufacturing Technique for the Shutdown-Functionalized Lithium-Ion Battery Separator Based on Al2O3 Coating Online Construction during the β-iPP Cavitation Process.

A shutdown-functionalized lithium-ion battery separator plays a pivotal role in preventing thermal runaway as cells experience electrical abuse, overcharge, and external short circuit. In this article, the trilayer separator endowed with shutdown function was fabricated by ingenious co-extrusion and bidirectional drawing based on the nano-Al2O3 coating online construction during the β-iPP cavitation process. The middle layer composed of nano-Al2O3, polyethylene, and polypropylene offers a shutdown temperature of 130 °C, and skin polypropylene layers with nano-Al2O3 coating hold optimized dimensional stability below the meltdown temperature. Crystal structure measurement and pore structure diagnosis disclose that nano-Al2O3 thins coarse fibrils and makes the porous structure uniform. De-bonding of nano-Al2O3/β-iPP interfaces retains nano-Al2O3 not only on the top surface of the separator but also on the pore intine to realize nano-Al2O3 coating online construction, consequently strengthening tensile capacity, dimensional stability to heating, and electrolyte affinity. Electrochemical tests further disclose that nano-Al2O3 coating stabilizes solid electrolyte interphase germination and heightens lithium-ion migration numbers, confining cell resistances and granting optimal high-rate performance and cycling ability. The proposed approach features simple technics, environment-friendly, continuous fabrication, and coating online construction, which can offer new ideas for the mass fabricating of the high-end separator.

Low-Cost and Large-Scale Fabricating Technology for High-Performance Lithium-Ion Battery Composite Separators with Connected Nano-Al2O3 Coating

The ever-increasing demand for high power density improves lithium-ion batteries. However, the poor microporous structure and inferior compatibility of separators heighten the lithium-ion migration barrier. Based on the cavitation of β-crystal polypropylene (β-iPP), separators with connected nano-Al2O3 coating are prepared by facile extrusion and biaxial stretching processes of β-iPP and nano-Al2O3. The crystal structure and microporous morphology diagnoses indicate that the moderate nano-Al2O3 content refines coarse fibrils and homogenizes pore size dispersion of the separator after biaxial stretching. Also, the connected nano-Al2O3 coating remains on the surface and inner pore wall because pores arise directly at nano-Al2O3/β-iPP interfaces, which endows the separator with superior electrolyte affinity. Assembled batteries further exhibit better C-rate capacity and cycle stability owing to the stable solid electrolyte interface formation and a higher lithium-ion transference number. Especially, the compound separator possesses the highest Li+ transference number of 0.53 and discharge capacity retention of 88.7% after 100 cycles as the nano-Al2O3 content is increased to 6%. This facile fabrication technique ameliorates the porous structure and electrochemical properties of the separator simultaneously, which provides practical guidance for the high-performance separator manufacturing technology in a large scale with low cost.

Three-dimensional crystal structure evolution and micropore formation of β-iPP during biaxial stretching

In this article, the crystalline and microporous structure evolution of β-iPP during sequential biaxial stretching are analyzed from a three-dimensional view. The calculated orientation and scanning electron microscope images show that the hedrites has intense cavitation during longitudinal stretching, leading to the lower orientation degree along with three-dimensional directions. But abundant coarse fibrils form during longitudinal stretching due to the three-dimensional asymmetric lamellae stack mode of hedrites. Consequently, these coarse fibrils hinder the slip and deflection of lamellae during the following transverse stretching and thus result in the uneven pore size distribution. However, the better compression performance obtains due to the plenty of connections or support structure along the thickness direction. On the other hand, the radial-growth spherulites slip significantly during longitudinal stretching, resulting in a much higher orientation degree along with three-dimensional directions and finer fibrils due to uniform dispersion of lamellae. Therefore, a more uniform pore size distribution with larger pore size can be detected on the surface after biaxial stretching. But the connection along thickness direction is much poor, causing the weak compression property. Therefore, it is critical to control the crystalline structure of β-iPP cast film during the practical processing.

BONE MARROW STUDY IN CASES OF HAEMATOLOGICAL DISORDERS

Introduction: There are various disorders in formation of blood in body. Bone marrow is one of them which involved variety of hematological and nonhematological disorders. Hematological disorders include myeloproliferative neoplasm (MPN), acute leukemia, hemato-lymphoid neoplasm and nutritional deficiency diseases whereas nonhematological disorders include infectious diseases infiltrating the bone marrow such as parasitic infections, tuberculosis and metastatic deposits. Bone marrows present various diseases with various clinical symptoms with the involvement of blood but peripheral blood picture alone does not reflect the nature of disease process. Depending upon the suspected diagnosis from clinical features and peripheral blood examination, that indication for bone marrow examination can be done. Examination of Bone marrow is useful in the diagnosis of both hematological and non-hematological disorders. The most important techniques used for the diagnosis of hematological disorders are trephine biopsy and bone marrow aspiration. For the interpretation of the disorder of bone marrow history, clinical finding, peripheral blood picture and other laboratory findings are required. Usually Bone marrow aspiration (BMA) alone is sufficient for the diagnosis of nutritional anaemias, most of the acute leukaemias and Immune thrombocytopenias. Diagnosis such as Trephine biopsy provides important diagnostic information myelofibrosis, granulomatous disease and bone marrow infiltration. Bone marrow aspiration is useful in making out better individual cell morphology whereas biopsy is useful in bone marrow architectural pattern and distribution. Bone marrow is nor mocellular or hypercellula resulting from ineffective hematopoiesis, increased peripheral destruction and bone marrow invasion. Therefore, bone marrow examination is extremely helpful to identify the cause of pancytopenia.
 Aim: The main aim of this study is to evaluate the cytological and histological pattern of various hematological disorders in bone marrow aspiration and trephine biopsy respectively.
 Material and Methods: During the period of 1 year 100 patient with the cases of haematological disorders were included in this study. Routinely stain like Leishman stain is used for bone marrow aspiration. Haematoxylin and eosin stain is also used for trephine biopsy. For all the cases reticulocyte count, peripheral smears, sickling test and complete hemogram were done. Special stains PAS Stain (Periodic acid schiff) was done for all ALL, AML and gauchers disease. In ALL cases Block positivity is shown. In gauchers disease, a gaucher cell shows wrinkled tissue paper appearance with PAS positivity. Reticulin stain was done in myelofibrosis and metastatic deposits. In myelofibrosis, trephine biopsy shows increase in reticulin network with coarse fibrils.
 Result: In all the cases bone marrow aspiration was done and among them 40 cases trephine biopsy were done. Out of total patients 57 were male and 43 were female. And the mean age was found as 32.6 years. The findings of the bone marrow were examination. At the time of study period 50% of the study have anemias and they are predominantly megaloblastic followed by aplastic/ hypoplastic anemias. Other three cases include two metastatic deposits and one storage disorder (Gaucher’s Disease).
 Conclusion: Bone marrow examination is important to diagnosis, prognosis or evaluate therapeutic response for a variety of hematologic and non-hematologic problems. Nowadays, Bone marrow aspiration & bone marrow biopsy are used routinely as diagnostic procedures because it is easier and does not require advance equipments. Therefore both the procedures are complementary to each other which are helpful in further investigation and management.
 Keywords: Bone marrow aspiration, Trephine biopsy, Pancytopenia, Megaloblastic Anemia

Pore formation and evolution mechanism during biaxial stretching of β-iPP used for lithium-ion batteries separator

The morphological evolution and pore formation mechanism of different kinds of β-iPP spherulites during biaxial stretching were analyzed. The smaller radial-growth spherulite deforms heterogeneous, causing a faster reduction in β-crystal content and higher orientation degree during longitudinal stretching, while the bigger spherulite derived from the hedrites deformed more homogeneous due to the more violent lamellae separation, causing a slower β-crystal content decline and lower orientation degree. However, plentiful coarse fibrils form within β-spherulite derived from the hedrites during longitudinal stretching due to abundant lamellae paralleled to the loading direction, with more connections between the coarse fibrils, which delayed the micropores formation and caused the inferior pore size distribution in following transverse stretching. While the radial-growth β-spherulite generates more refined microfibrils and the higher orientation means lesser connection between finer fibrils, making abundant micropores at the beginning of transverse stretching and superior pore size distribution throughout the whole transverse stretching ultimately.

Effect of high molecular weight on pore formation and various properties of microporous membrane used for lithium-ion battery separator

In this article, iPP cast films with high molecular weight in middle layer were prepared to investigate the effect of high molecular weight component on pore formation and mechanical strength. The results of DSC, SEM and 2D-XRD indicated that higher molecular weight and die draw ratio (DDR) would not alter the thickness of lamellae but enhance the orientation and the content of extend-chain crystal. Then the tensile testing results show that higher DDR would improve the overall strength and the elastic recovery substantially but reduce the elongation at break dramatically. Additionally, the cast film containing higher molecular weight component has longer elongation and yield stress but shows a more gentle decrease of elastic recovery during the repeatedly stretching cycle. Moreover, further detailed characterization of the microporous structure after uniaxial stretching manifest that lower DDR is extremely unfavorable to pore formation, resulting in lowest porosity and poorer pore size distribution. While this inferior microporous structure would be improved by increasing DDR, accompanied by ascending porosity. Moreover, the membrane completely composed of high molecular weight also exhibits more coarse fibrils, which is stemmed from the undivided row-nucleated lamellae. Furthermore, the puncture and tensile strength were reinforced by boosting molecular weight and DDR significantly, which is more beneficial to battery assembly and safety.

Effect of Fumed SiO2 on Pore Formation Mechanism and Various Performances of β-iPP Microporous Membrane Used for Lithium-ion Battery Separator

In this work, four samples containing different contents of fumed SiO2 were prepared to improve the pore size distribution and various properties of β nucleated isotatic polypropylene (β-iPP) biaxial membrane used for lithium-ion battery separator. The wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) results show that the fumed SiO2 promotes the formation of β-crystal slightly and narrows down the thickness distribution of β-lamellae; meanwhile, evenly distributed SiO2 within β-iPP can be inspected by scanning electron microscopy (SEM). Moreover, further detailed characterization of morphological evolutions during biaxial stretching by tensile testing and SEM manifests that SiO2 can strengthen β-iPP and make the samples deform more homogeneously, resulting in a gradually elaborate and finer oriented microfibril structure after longitudinal stretching, in which more uniform defects distribute between fibrils and restrain the formation of coarse fibrils effectively. Therefore, more superior microporous structure emerges with the addition of SiO2, accompanied by narrower pore size distribution and better connectivity between microvoids, which is confirmed by mercury porosimeter and diminished Gurley value. Moreover, the lower thermal shrinkage, decreased shrinkage rate and suppressed porosity reduction indicate that fumed SiO2 improves thermal and dimensional stability of membrane dramatically. Furthermore, due to the excellent wettability of SiO2 with electrolyte, the microporous membranes doped with SiO2 have higher electrolyte uptake, even after heat treatment at elevated temperature.

Investigation of deformation and pore formation in isotactic polypropylene containing active nano-CaCO3

In order to improve the β-lamellae distribution and properties of β-iPP membrane, 5% and 10% active nano-CaCO3 were added into β-iPP. The DSC, XRD and SEM results show that nano-CaCO3 would not reduce the content of β-crystal, but the thickness, lamellae thickness distribution and stability of β-lamellae decrease apparently. Then the tensile test was conducted at 25 °C and 90 °C. The results manifested that the second yield point, which has a strong negative correlation with lamellae thickness distribution, delays monotonously with adding nano-CaCO3 when stretched at 25 °C, indicating that nano-CaCO3 could narrow down the lamellae thickness distribution of β-iPP effectively. Furthermore, when stretched at 90 °C, the subdued yield peak, retarded necking down phenomenon and enhanced strain-hardening modulus demonstrated that the deformation stability improves gradually with introduction of nano-CaCO3, which has completely opposite law to the β-lamellae stability. Through further detailed characterization of morphological evolutions during stretching, we found that the interfacial debonding between nano-CaCO3 and β-iPP is triggered and abundant microviods can be formed, which can retard the rotation and slip of β-lamellae and make β-α transformation slow down in the initial stage of stretching, consequently make a better isotropic deformation. Moreover, nano-CaCO3 could restrain the formation of coarse fibrils efficiently, leading to more uniform pore size distribution within biaxial stretching microporous membrane. However, excessive nano-CaCO3 (10%) would cause the aggregation within the β-iPP cast film and finally resulted in larger pores and poor pore distribution in the membrane.

Diagnostic Exome Sequencing Identifies a Novel Gene, EMILIN1, Associated with Autosomal-Dominant Hereditary Connective Tissue Disease.

ABSTRACTHeritable connective tissue diseases are a highly heterogeneous family of over 200 disorders that affect the extracellular matrix. While the genetic basis of several disorders is established, the etiology has not been discovered for a large portion of patients, likely due to rare yet undiscovered disease genes. By performing trio‐exome sequencing of a 55‐year‐old male proband presenting with multiple symptoms indicative of a connective disorder, we identified a heterozygous missense alteration in exon 1 of the Elastin Microfibril Interfacer 1 (EMILIN1) gene, c.64G>A (p.A22T). The proband presented with ascending and descending aortic aneurysms, bilateral lower leg and foot sensorimotor peripheral neuropathy, arthropathy, and increased skin elasticity. Sanger sequencing confirmed that the EMILIN1 alteration, which maps around the signal peptide cleavage site, segregated with disease in the affected proband, mother, and son. The impaired secretion of EMILIN‐1 in cells transfected with the mutant p.A22T coincided with abnormal protein accumulation within the endoplasmic reticulum. In skin biopsy of the proband, we detected less EMILIN‐1 with disorganized and abnormal coarse fibrils, aggregated deposits underneath the epidermis basal lamina, and dermal cells apoptosis. These findings collectively suggest that EMILIN1 may represent a new disease gene associated with an autosomal‐dominant connective tissue disorder.

Microstructure of Tracheids ofNymphaea

Hand sections of root and stem xylem of diverse species of Nymphaea (including Ondinea) were studied with SEM in order to explore the diversity of wall structure within the genus. Lateral walls of root tracheary elements are untextured at the magnifications used, but end wall structure suggests that lysis of pit membranes leaves a cellulosic network with a large reticulum. Stem tracheids have lateral walls that are untextured or have a few prominent fibrils, but end walls have a dense accretion of coarse fibrils. These fibrils form a spongiform or compressed network overlying the pit membranes. In addition, on the lumen side of pit membranes, coarse fibrils cross the pits in an axial direction. These coarse fibrils are connected to pit borders, and they may extend onto wall surfaces of the tracheary elements. These fibrillar accretions are considered here to fulfill criteria as secondary‐wall components. Variation within the genus with respect to the fibrillar accretions may occur, but there may be more extensive diversity within any given sample than among species. Root tracheary elements could be considered to be vessel elements because of the extensive removal of wall material from the end‐wall pit membranes. Stem tracheary elements qualify as tracheids because, rather than showing lysis of pit‐membrane portions, end‐wall pit membranes bear fibrillar accretions that are only sparsely porose. The absence of coarse fibrillar accretions on lateral walls of stem tracheids (on tracheid‐to‐parenchyma interfaces) provides difficulty for any hypothesis that would relate wall thickenings to turgor pressure. The patterns of fibrillar accretion observed in Nymphaea include all patterns thus far reported from stem tracheids in the other genera of the family, and they must be considered to be a characteristic of Nymphaeaceae.

Distinctive tracheid microstructure in stems ofVictoriaandEuryale(Nymphaeaceae)

Scanning electron microscopy (SEM) photographs of thick sections from liquid-preserved stems of Victoria cruziana and Euryale ferox show accretions of coarse fibrils on pit membranes of tracheids. The first-deposited fibrils are randomly orientated; on top of them (facing the tracheid lumina) are axially orientated coarse fibrils. The two systems are interconnected. Axially orientated fibrils were more extensively observed in Euryale than in Victoria and tips of fibrils in Euryale extend over the pit apertures onto secondary wall surfaces. Tracheid–parenchyma interfaces bear rudimentary coarse fibrils on the tracheid side. End walls of Victoria tracheids have highly porose pit membranes, thinner and less complex than those of the lateral intertracheid walls. The structures reported in Victoria and Euryale are consistent with those concurrently reported for stems of other Nymphaeaceae. Although also present in Cabombaceae, the coarse fibrils are otherwise not reported for stems of angiosperms and are not yet reported in roots of any species. Pit membrane remnants in perforation plates of various woody dicotyledons represent a nonhomologous phenomenon. The accretions of coarse fibrils in stem tracheids of Nymphaeaceae do not appear to enhance conduction, although they do contain porosities interconnecting tracheids. Removal of pit membrane remnants from perforation plates of primitive dicotyledon woods by hydrolysis does, on the contrary, suggest conduction enhancement. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159, 52–57.

Xylem of early angiosperms: Nuphar (Nymphaeaceae) has novel tracheid microstructure1

SEM studies of xylem of stems of Nuphar reveal a novel feature, not previously reported for any angiosperm. Pit membranes of tracheid end walls are composed of coarse fibrils, densest on the distal (outside surface, facing the pit of an adjacent cell) surface of the pit membrane of a tracheid, thinner, and disposed at various levels on the lumen side of a pit membrane. The fibrils tend to be randomly oriented on the distal face of the pit membrane; the innermost fibrils facing the lumen take the form of longitudinally oriented strands. Where most abundantly present, the fibrils tend to be disposed in a spongiform, three-dimensional pattern. Pores that interconnect tracheids are present within the fibrillar meshwork. Pit membranes on lateral walls of stem tracheids bear variously diminished versions of this pattern. Pits of root tracheids are unlike those of stems in that the lumen side of pit membranes bears a reticulum revealed on the outer surface of the tracheid after most of the thickness of a pit membrane is shaved away by the sectioning process. No fibrillar texturing is visible on the root tracheid pits when they are viewed from the inside of a tracheid. Tracheid end walls of roots do contain pores of various sizes in pit membranes. These root and stem patterns were seen in six species representing the two sections of Nuphar, plus one intersectional hybrid, as well as in one collection of Nymphaea, included for purposes of comparison. Differences between root and stem tracheids with respect to microstructure are consistent in all species studied. Microstructural patterns reported here for stem tracheid pits of Nymphaeaceae are not like those of Chloranthaceae, Illiciaceae, or other basal angiosperms. They are not referable to any of the patterns reported for early vascular plants. The adaptational nature of the pit membrane structure in these tracheids is not apparent; microstructure of pit membranes in basal angiosperms is more diverse than thought prior to study with SEM.

Impact of brief exposure to balanced salts solution or cetylpyridinium chloride on the surface appearance of the rabbit corneal epithelium – a scanning electron microscopy study

Purpose. To examine the surface of pre-corneal mucous layer by scanning electron microscopy (SEM) with the view to assessing whether it was an amorphous, fibrous or porous structure. Methods. Healthy female albino rabbits (2kg) were euthanised at 15.00 h and the corneal surface immediately fixed with buffered glutaraldehyde fixative pH 7.2 to 7.4 at 35°C, carefully rinsed with balanced salts solution (BSS) and then fixed, or treated with the same fixative containing 0.05 to 0.25% w/v cetylpyridinium chloride (CPC). The corneas were critical point dried and gold-palladium coated, prior to examination at 1000× or 15 000× magnification. Results. Buffered glutaraldehyde fixation resulted in an SEM image of polygonal cells, with very contrasting electron reflexes (light, medium and dark) and distinct cell surface microplicae and large crater-like features (average diameter 2.8 ± 0.9µm). Along the cell-cell borders was a distinct line (referred to as “caulking”), perhaps composed of mucous. Rinsing of the corneal surface with BSS just before fixation reduced the cell contrast, the surface was then covered with very short strands or small clumps of presumed mucus, the cell-cell border features were changed, but the crater-like features were largely unchanged (average diameter 2.5 ± 0.7µm). Fixation in the presence of 0.05% or 0.1% CPC resulted in the appearance of very short fine strands and occasional coarse mucous strands or even small plaques of mucous on the cell surfaces. The microplicae and craters were still often evident. Fixation with 0.2 or 0.25% CPC however yielded a surface with a uniform grey reflex that included numerous ultramicroscopic debris particles (average diameter of 72 nm) and was punctuated by numerous pores. No microplicae or craters were evident. The average pore diameter was 70 nm, their density averaged 59/5 µm 2, but a radial distribution analysis indicated no substantial pattern. Conclusions. The pre-corneal mucous layer can be dispersed, by careful rinsing with a divalent cation containing solution, into small fibrils or clumps, but the cell surface craters are unaffected. After precipitation with a low concentrations of a polycation, some coarse fibrils are also formed. The use of high concentrations of a polycation in the fixative transforms the more superficial aspects of the pre-corneal mucous layer into a pore-like gel. The crater-like features therefore do not appear to be mucous, but the pore-like structure may be indicative of the organisation of the mucous layer on the surface of the living eye.

Fibrillary (Immunotactoid) Glomerulopathy A Possible Role for Kappa Light Chain in Its Etiology and/or Pathogenesis

The initial clinical manifestations, course, and immunopathologic findings of renal biopsies of nine patients with fibrillary glomerulopathy are reported. Their first symptoms and courses were variable, but proteinuria and renal failure were common. While some patients required hemodialysis soon after coming for treatment, others progressed to renal failure over several years. Three patients had monoclonal gammopathy; one of them had an isolated, transient, Bence-Jones proteinuria. The main pathologic features are glomerular enlargement, mesangial expansion, and mild hypercellularity. Congo red and thioflavin stains were negative. Kappa chain, either alone or with lambda chain and IgG, were the predominant immunoreactants. Ultrastructurally, the presence of coarse fibrils of 15-25 nm was characteristic, but there were also granular deposits in the capillary wall that occurred in a band-like pattern in the inner half of the glomerular basement membrane in a manner similar to the deposits seen in light chain deposit disease. The immunofluorescence and ultrastructural findings suggest that light chains (especially kappa) may be significant in the pathogenesis of fibrillary glomerulopathy and that there may be a relationship with light chain deposit disease.

Stimulation of Fibronectin Secretion in Cultured Human Keratinocytes by Transforming Growth Factor‐β Not by Other Growth Inhibitory Substances

We investigated the effects of various growth inhibitory substances on fibronectin secretion in cultured normal human keratinocytes. Fibronectin secretion in keratinocytes was expressed by two methods: immunofluorescent staining of cells with anti-human fibronectin antibody, and sodium dodecyl-sulphate-polyacrylamide gel electrophoresis of [35S]-labeled proteins secreted by the cells followed by autoradiography. With immunofluorescent staining, the extracellular fibronectin was observed as coarse fibrils only in some cells of the control culture, while cells treated with 20 ng/ml transforming growth factor-beta 1 (TGF-beta 1) showed intense fluorescences in a radiating pattern around most of the cells, indicating that TGF-beta 1 markedly increased fibronectin secretion in keratinocytes. Analysis of [35S]-methionine labeled proteins also revealed that TGF-beta 1 increased fibronectin secretion eight fold in culture medium. TGF-beta 2 has also induced weak increase of fibronectin secretion 1.8 fold in keratinocytes. In contrast, other growth inhibitory substances, such as tumor necrosis factor-alpha, 1,25-dihydroxyvitamin D3 and cyclosporin A, did not show any significant effects on fibronectin secretion. These results indicated that increase of fibronectin secretion is not associated with growth inhibitory effect, but rather with a specific effect of TGF-beta.

Pathological changes in the gill filaments of Acanthopagrus australis (family Sparidae) associated with the post‐settlement growth of a lernaeopodid copepod, Alella macrotrachelus

The extent of the histopathology associated with the attachment of post‐settlement stages of the lernaeopodid copepod Alella macrotrachelus on the gills of Acanthopagrus australis was related to parasite size. Initial penetration of the attachment organ into the epithelium was associated with hyperplasia, oedema and accumulation of infiltrating cells in the immediate vicinity of the frontal filament or bulla. Adult parasites caused crypting and fusion of filaments with associated chronic inflammation. Penetration of the bulla into the connective tissue invoked fibroplasia and chondrocyte proliferation that enclosed the bulla. The bulla matured from the centre to the periphery by a condensation of the matrix into coarse fibrils. The bulla was delineated by a tri‐laminar wall from the surrounding connective tissue fibrils.

Characteristics of asbestiform and non-asbestiform calcic amphiboles

In terms of morphology there are four major types of calcic amphibole; massive, prismatic, finely acicular and asbestos. Representatives of each of these types have been examined by optical microscopy, X-ray diffraction, scanning and transmission electron microscopy, and electron probe microanalysis. Massive specimens (nephrite) consist of randomly oriented clusters of fine, roughly lath-shaped, sub-microscopic crystals; within each cluster the lath lengths ( z) are approximately aligned but neighbouring laths are rotated with respect to one another. Finely acicular specimens (“byssolites”) have well-formed crystals bounded mainly by {110} (100) and (010) faces and characteristically have striations parallel to their lengths. Asbestiform varieties range from finer (flexible) to coarser (more brittle) specimens and many specimens contain a mixture of fine and coarse fibrils. The fibrils in a bundle are aligned parallel to z but are in a range of azimuthal orientations. It is inferred that they are formed by multiple independent nucleation and growth parallel to z rather than through parting or cleavage on {110} planes. (100) defect or twin planes, or on (010) planar defects. The {110} cleavage in amphiboles is well reported but (100) features are rarely mentioned in the literature. Our observations reveal the importance of (100) as a cleavage or parting as well as the tendency in nephrites, byssolites and asbestos towards a lath-like (parallel to z) morphology with flattening on (100). In the latter varieties therefore, the y-direction is that of second fastest crystal growth, after z. When subjected to moderate grinding, the comminution of asbestos fibres proceeds more by separation of fibrils and less by fracturing to shorter lengths as compared with prismatic and byssolite specimens. Prolonged grinding does, however, shorten lengths of even the least brittle asbestos. Transmission electron microscopy revealed extensive sub-grain boundaries and dislocation networks (suggesting a deformation history) in all prismatic and nephrite specimens. Fine multiple (100) twinning was observed in asbestos but not in other varieties. Although chain-width defects [on (010)], with visibility enhanced by beam damage, were most abundant in nephrites and fibrous tremolites, there appears to be no completely consistent relationship between such features and morphological type. Electron probe analyses showed that specimens that contain more than a very small amount of aluminium do not have asbestiform habit. Asbestos specimens also have lower contents of Mn, Na and K and have formulae closer to the ideal Ca 2(Mg,Fe) 5Si 8O 22(OH) 2. Small departures from this in asbestos involve Na in the A site compensated by Na for Ca rather than Al for Si whereas the reverse is true in byssolites. Chemical substitutions in prismatic specimens are much less constrained. The characteristics of the four morphological sub-groups correlate reasonably well with what is known of their geological environments.

Scanning electron microscopic study of giant tubule content in bovine dentin.

Incisal segments of unerupted permanent incisors from 1/2-1 1/2-yr-old calves were fractured along an axiomesiodistal plane exposing the organic components within the giant tubule lumina situated in this plane. Along the lining wall of the pulpal vascularized giant tubule portion, large flattened cells and a few odontoblasts were situated in shallow depressions. Just incisal to the vascular loop numerous cells were seen, both along the giant tubule wall and enclosed within a loosely textured collagenous matrix. Further incisally, the number and size of the cells decreased, and they were embedded in a compact unmineralized collagenous matrix that completely filled out the giant tubule lumina. This matrix consisted of fibrils regularly arranged in separate bundles whose orientation was mainly longitudinal. The incisal origins of the giant tubules were filled with coarse fibrils being about three times thicker than those of the luminal matrix and those of the circumpulpal dentin proper.