Microspherophakia-Metaphyseal Dysplasia: A 'New' Dominantly Inherited Bone Dysplasia with Severe Eye Involvement

in Journal of Medical Genetics (1990), 27(7), 467-71

We report a father and son affected by a hitherto unpublished bone dysplasia with moderately severe dwarfism. On initial radiographs, thickening of the diaphyses of the long bones was striking. The small ... [more ▼]

We report a father and son affected by a hitherto unpublished bone dysplasia with moderately severe dwarfism. On initial radiographs, thickening of the diaphyses of the long bones was striking. The small bones of the extremities were almost unaffected. With age, the metaphyseal deformation became more prominent. The epiphyses became irregular and their growth was delayed (particularly the femoral heads). The femoral neck showed an unusual 'lip' on the inner edge. Later, the stubby appearance of the long bones faded and, in adulthood, only enlarged metaphyses and deformed femoral necks persisted. The vertebrae showed moderate deformation with irregular flattening, and narrowing of the spinal canal with a shortened interpedicular distance. The eye defects consisted of high grade myopia, microspherophakia, lens coloboma, lens luxation, and retinal detachment. The name 'microspherophakia-metaphyseal dysplasia' is suggested for this probably autosomal dominant bone dysplasia. [less ▲]

Microsporum canis keratinolytic enzymes as virulence factors

Conference (2000)

Microstructural degeneracy associated with a two-point correlation function and its information content

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2012), 85

A two-point correlation function provides a crucial yet an incomplete characterization of a microstructure because distinctly differentmicrostructures may have the same correlation function. In an earlier ... [more ▼]

A two-point correlation function provides a crucial yet an incomplete characterization of a microstructure because distinctly differentmicrostructures may have the same correlation function. In an earlier Letter [Gommes, Jiao, and Torquato, Phys. Rev. Lett. 108, 080601 (2012)], we addressed the microstructural degeneracy question: What is the number of microstructures compatible with a specified correlation function? We computed this degeneracy, i.e., configurational entropy, in the framework of reconstruction methods, which enabled us to map the problem to the determination of ground-state degeneracies. Here, we provide a more comprehensive presentation of the methodology and analyses, as well as additional results. Since the configuration space of a reconstruction problem is a hypercube on which a Hamming distance is defined, we can calculate analytically the energy profile of any reconstruction problem, corresponding to the average energy of allmicrostructures at a given Hamming distance from a ground state. The steepness of the energy profile is a measure of the roughness of the energy landscape associated with the reconstruction problem, which can be used as a proxy for the ground-state degeneracy. The relationship between this roughness metric and the ground-state degeneracy is calibrated using a Monte Carlo algorithm for determining the ground-state degeneracy of a variety of microstructures, including realizations of hard disks and Poisson point processes at various densities as well as thosewith known degeneracies (e.g., single disks of various sizes and a particular crystalline microstructure). We show that our results can be expressed in terms of the information content of the two-point correlation functions. From this perspective, the a priori condition for a reconstruction to be accurate is that the information content, expressed in bits, should be comparable to the number of pixels in the unknown microstructure. We provide a formula to calculate the information content of any two-point correlation function, which makes our results broadly applicable to any field in which correlation functions are employed. [less ▲]

Microstructural size effects on mechanical properties of high purity nickel

in International Journal of Plasticity (2011), 27

The aim of this article is to provide experimental results in order to understand the microstructural size effects which occur with a decrease in the thickness of polycrystalline nickel samples from 3.2 ... [more ▼]

The aim of this article is to provide experimental results in order to understand the microstructural size effects which occur with a decrease in the thickness of polycrystalline nickel samples from 3.2 mm to 12.5 lm. The influence of the thickness, grain size and ratio thickness to grain size on the mechanical properties and strain hardening were investigated by mechanical tests and TEM observations. The results show the presence of three different domains of mechanical behaviour: polycrystalline, multicrystalline and quasi-single crystalline depending on the thickness and on the number of grains across the thickness. The transition between the three domains is due to the occurrence of surface effects involving a decrease in the long-range internal backstress revealed by the TEM observations. [less ▲]

A Microstructural Study of Doped-LaGaO3 (La0.9Sr0.1Ga0.8Mg0.2O2.85) Produced by an Autocombustion from a Gel-like Precursor

in Bossel, Ulf (Ed.) Sixth European Solid Oxide Fuel Cell Forum - Proceedings (2004, June)

Polycrystalline dense samples of lanthanum gallate doped with strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85 or LSGM) was prepared using a novel gel precursor synthesis method. This consists in ... [more ▼]

Polycrystalline dense samples of lanthanum gallate doped with strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85 or LSGM) was prepared using a novel gel precursor synthesis method. This consists in preparing a LSGM precursor from a freeze-dried Agar-Agar gel. After the freeze-drying step, the dry residue is put in an oven at 120°C where autocombustion occurred. The as-produced powders are then calcined. Investigations are made to follow both structural and microstructural evolutions from the dry residue to the end product. The effect of the temperature evolution was examined by thermogravimetric analysis, X-ray diffraction, environmental scanning electron microscopy, and specific surface area analysis. Dilatometric curves and density measurements have been also performed on the sintered products. Advantages of this method are the ability to control size distribution and to obtain high density materials without any milling step thus avoiding any contamination coming from the grinding medium. [less ▲]

Microstructural study of oxides and carbides used for abrasion properties in high alloyed steels

in Proceedings of the 8th International Conference on Composites Engineering (2001)

For long applications and for many others, a material with properties between hard metal and high speed steel is necessary. This material should have a high resistance to wear together with good toughness ... [more ▼]

For long applications and for many others, a material with properties between hard metal and high speed steel is necessary. This material should have a high resistance to wear together with good toughness. An attractive solution consists in combining in a composite the properties of a tough ferrous matrix with those of hard reinforced particles. In varying the nature and the proportions of reinforcement and matrix, the properties of the composite can cover many applications. [less ▲]

Microstructural study of Zn-Al alloy

in Proceedings of The 4th Physics and Chemistry of Solids, School-Symposium Physics of Metals, Polish Academy of Sciences, Institute for Low Temperature and Structure Research (1987)

It is well known that zinc-aluminium alloys posses very good mechanical properties. This is the reason why the investigation of their ageing characteristics is very important for the practice. Several ... [more ▼]

It is well known that zinc-aluminium alloys posses very good mechanical properties. This is the reason why the investigation of their ageing characteristics is very important for the practice. Several solid state reactions between alpha, beta, epsilon and T phases have been established for such materials alloyed with copper, but there has been no detailed on the formation, development and transformation of metastable phases into stable ones. This is exactly the aim of our investigation. [less ▲]

Microstructure and abrasion resistance of tool steels reinforced by dispersed oxides and carbides phases

in Revue de Métallurgie- Journées d'Automne de la Société Française de Métallurgie et de Matériaux (2000)

Two ferrous matrix, a high speed steel and a maraging steel were reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy. The particles were mechanically ... [more ▼]

Two ferrous matrix, a high speed steel and a maraging steel were reinforced with alumina, titanium and vanadium carbides. The composite was realized by powder metallurgy. The particles were mechanically mixed with the prealloyed powder before compaction. To optimize the composite properties, the processing parameters (i.e. prealloyed powders, size, mixing, conditions, temperature of sintering,...) and the effect of reinforcement (size and composition of particles, volume, fraction,...) were studied. It is necessary to obtain full density with minimum porosity and to control the size, distribution and dispersion of the reinforced particles. The optimal sintering temperature depends on the reinforcement particles used and is of great importance for the properties. Processing parameters (mixing of particles) can greatly affect the final properties. The use of AL2O3 was shown to increases wear resistance in the two matrix. [less ▲]

Microstructure and mechanical properties of stir processed magnesium matrix composites reinforced with carbon fibres

Conference (2012, January 26)

Mg-Al-Zn alloys have been reinforced with carbon fibres using friction stir processing (FSP) which appears as a promising alternative for the large-scale production of C-Mg composites. The process has ... [more ▼]

Mg-Al-Zn alloys have been reinforced with carbon fibres using friction stir processing (FSP) which appears as a promising alternative for the large-scale production of C-Mg composites. The process has shown its ability to produce sound composites with enhanced strength compared to the non-reinforced alloys. The C fabric is fragmented in short fibres leading to a reduction in grain size and an improved hardness. [less ▲]

Microstructure and properties of rapid heat treated and galvanised dual-phase steel

Poster (2006, May)