Congenital Mesoblastic Nephroma: A Case Report.

Congenital mesoblastic nephromas are rare renal tumours that are encountered in paediatric age group. A term female neonate at the end of first week of life presented with bilateral lower limb swelling. On radiological evaluation, ultrasonography revealed an intra-abdominal mass which was managed with radical nephroureterectomy. Histopathological examination confirmed a diagnosis of congenital mesoblastic nephroma of mixed subtype. Keywords: case reports; congenital mesoblastic nephroma; kidney neoplasms; nephrectomy.

Ab initio predictions of structure and physical properties of the Zr2GaC and Hf2GaC MAX phases under pressure.

The electronic structure, structural stability, mechanical, phonon, and optical properties of Zr2GaC and Hf2GaC MAX phases have been investigated under high pressure using first-principles calculations. Formation enthalpy of competing phases, elastic constants, and phonon calculations revealed that both compounds are thermodynamically, mechanically, and dynamically stable under pressure. The compressibility of Zr2GaC is higher than that of Hf2GaC along the c-axis, and pressure enhanced the resistance to deformation. The electronic structure calculations reveal that M2GaC is metallic in nature, and the metallicity of Zr2GaC increased more than that of Hf2GaC at higher pressure. The mechanical properties, including elastic constants, elastic moduli, Vickers hardness, Poisson's ratio anisotropy index, and Debye temperature, are reported with fundamental insights. The elastic constants C11 and C33 increase rapidly compared with other elastic constants with an increase in pressure, and the elastic anisotropy of Hf2GaC is higher than that of the Zr2GaC. The optical properties revealed that Zr2GaC and Hf2GaC MAX phases are suitable for optoelectronic devices in the visible and UV regions and can also be used as a coating material for reducing solar heating at higher pressure up to 50 GPa.

Theoretical Study on Structural Stability and Elastic Properties of Fe25Cr25Ni25TixAl(25-x) Multi-Principal Element Alloys.

Material genetic engineering studies the relationship between the composition, microstructure, and properties of materials. By adjusting the atomic composition, structure, or configuration of the material and combining different processes, new materials with target properties obtained. In this paper, the design, and properties of the ordered phases in Fe25Cr25Ni25TixAl(25-x) (subscript represents the atomic percentage) multi-principal element alloys are studied. By adjusting the percentages of Ti and Al atoms, the effect of the atomic percentage content on ordered phases' structural stability in multi-principal element alloys are studied. Thermodynamic analysis predicted the composition phase and percentage of the alloy. Formation heat, binding energy, and elastic constants confirmed the structural stability and provide a theoretical basis for designing alloys with target properties. The results showed that the disordered BCC A2 phase and the ordered BCC B2 phase are the ductile phases, while the Laves phase is brittle. The research method in this paper is used to design multi-principal element alloys or other various complex materials that meet the target performance.

Extra-adrenal paraganglioma of a urinary bladder in an adolescent male: A rare case report.

INTRODUCTION AND IMPORTANCE: Paraganglioma of the urinary bladder is unusual and reported rarely. The patient usually presents with the complaint of hematuria and fluctuating blood pressure. CASE PRESENTATION: We discuss the case of a 21-year old male, who had been experiencing gross hematuria, was found to have a mass on ultrasonography. Further evaluation with contrast-enhanced computerized tomography (CECT) revealed an irregular soft tissue density of endophytic mass arising from the left posterior wall of the urinary bladder. The histopathological examination of the excised mass was suggestive of a tumor of neural origin, which was further confirmed as paraganglioma by immunohistochemistry. CLINICAL DISCUSSION: Imaging prior to the surgery must be done for a provisional diagnosis of paraganglioma to avoid fluctuating blood pressure during elective surgery. On histopathological examination tumor cells are arranged in the nest like fashion forming a specific 'Zellballen' pattern. Positive staining for synaptophysin and chromogranin in immunohistochemistry confirms the diagnosis. CONCLUSION: It is difficult to diagnose paraganglioma of the urinary bladder with the aid of imaging only, particularly if the patient presents without specific symptoms of fluctuating blood pressure. So, a multidisciplinary approach is essential for the diagnosis and proper therapy of this entity. However, prompt surgical resection is the mainstay of treatment.

Structural Stability, Electronic, Mechanical, Phonon, and Thermodynamic Properties of the M2GaC (M = Zr, Hf) MAX Phase: An ab Initio Calculation.

The novel ternary carbides and nitrides, known as MAX phase materials with remarkable combined metallic and ceramic properties, offer various engineering and technological applications. Using ab initio calculations based on generalized gradient approximation (GGA), local density approximation (LDA), and the quasiharmonic Debye model; the electronic, structural, elastic, mechanical, and thermodynamic properties of the M2GaC (M = Zr, Hf) MAX phase were investigated. The optimized lattice parameters give the first reference to the upcoming theocratical and experimental studies, while the calculated elastic constants are in excellent agreement with the available data. Moreover, obtained elastic constants revealed that both the Zr2GaC and Hf2GaC MAX phases are brittle. The band structure and density of states analysis showed that these MAX phases are electrical conductors, having strong directional bonding between M-C (M = Zr, Hf) atoms due to M-d and C-p hybridization. Formation and cohesive energies, and phonon calculations showed that Zr2GaC and Hf2GaC MAX phases' compounds are thermodynamically and dynamically stable and can be synthesized experimentally. Finally, the effect of temperature and pressure on volume, heat capacity, Debye temperature, Grüneisen parameter, and thermal expansion coefficient of M2GaC (M = Zr, Hf) are evaluated using the quasiharmonic Debye model from the nonequilibrium Gibbs function in the temperature and pressure range 0-1600 K and 0-50 GPa respectively.

Theoretical and Experimental Studies of the Structural, Phase Stability and Elastic Properties of AlCrTiFeNi Multi-Principle Element Alloy.

The fundamental challenge for creating the crystal structure model used in a multi-principle element design is the ideal combination of atom components, structural stability, and deformation behavior. However, most of the multi-principle element alloys contain expensive metallic and rare earth elements, which could limit their applicability. Here, a novel design of low-cost AlCrTiFeNi multi-principle element alloy is presented to study the relationship of structure, deformation behavior, and micro-mechanism. This structured prediction of single-phase AlCrTiFeNi by the atomic-size difference, mixing enthalpy ΔHmix and valence electron concentration (VEC), indicate that we can choose the bcc-structured solid solution to design the AlCrTiFeNi multi-principle element alloy. Structural stability prediction by density functional theory calculations (DFT) of single phases has verified that the most advantageous atom occupancy position is (FeCrNi)(AlFeTi). The experimental results showed that the structure of AlCrTiFeNi multi-principle element alloy is bcc1 + bcc2 + L12 phases, which we propose as the fundamental reason for the high strength. Our findings provide a new route by which to design and obtain multi-principle element alloys with targeted properties based on the theoretical predictions, first-principles calculations, and experimental verification.