Transungual surgical excision of subungual glomus tumour

Background: Glomus tumours are rare vascular tumours arising subungually in fingernails. Surgical excision provides histopathologic diagnosis and rapid resolution of symptoms. Objective: Present study was aimed at delineating common presentations and long-term treatment outcome of this rare subungual tumour. Patients and Methods: The clinical features and imaging results for 10 patients with subungual glomus tumours were recorded. All were treated with transungual excision. Per-operative findings and, treatment outcomes were recorded and analysed. Results: Females outnumbered males with average age being 33.3 ± 7.55 years. Presenting symptoms were severe pain (100%); nail-plate discoloration and onycholysis. X-ray was normal in 70%, though a magnetic resonance imaging done for five, helped visualise the lesion in three patients. The tumour involved nail bed in five cases and matrix in five, with an average size being 6.1 ± 2.13 mm (range 3-11 mm). An average follow-up of 16.8 months (range 8-24 months) was largely uneventful with longitudinal ridging in two cases and recurrence in two (both attributed to a sister lesion). Conclusion: Subungual glomus tumours have characteristic clinical presentation. Imaging is helpful pre-operatively but has a low success rate. Transungual surgical excision is safe and effective, allowing better visualisation, easy exploration and minimal long-term complications

X-ray diffraction and Raman spectroscopic investigation on the phase relations in Yb<SUB>2</SUB>O<SUB>3</SUB>- and Tm<SUB>2</SUB>O<SUB>3</SUB>- substituted CeO<SUB>2</SUB>

Powder X-ray diffraction (XRD) and Raman spectroscopic studies on Ce<SUB>1−x</SUB>YbxO<SUB>2−x/2</SUB> and Ce<SUB>1−x</SUB>TmxO<SUB>2−x/2</SUB> (0.0≤x≤1.0) are being reported in this manuscript. It has been observed that ceria when heavily doped with ytterbia and thulia get transformed from single-phasic F type to single-phasic C type through the formation of a biphasic mixture. The critical concentrations at which the phase transition takes place have also been ascertained from XRD measurements and verified using Raman spectroscopy. From XRD studies, it has been found that in the case of Ce<SUB>1−x</SUB>YbxO<SUB>2−x/2</SUB>, pure F-type lattice continues until x=0.4 and then the biphasic region comprising F-type and C-type solid solutions starts, which is followed by single-phasic pure C-type region above x=0.9. For Ce<SUB>1−x</SUB>TmxO<SUB>2−x/2</SUB>, XRD studies reveal that the biphasic region comprising C-type and F-type lattice is formed from x=0.5 onward. However, it has been confirmed from Raman spectroscopic studies that the C-type lattice is formed even in the sample at x=0.4. The discrepancy is believed to have originated because of the small domain size (smaller than the coherence length of X-rays) of the C-type lattice that are inhomogeneously distributed within the F-type solid solution in the composition Ce<SUB>1−x</SUB>TmxO<SUB>2−x/2</SUB> (x=0.4), which could not be directly detected from XRD measurements

Synthesis and structural and electrical investigations of a hexagonal Y<SUB>1–x</SUB>Gd<SUB>x</SUB>InO<SUB>3</SUB>(0.0 ≤x≤ 1.0) system obtained via metastable C-type intermediates

Detailed structural and electrical investigations were carried out on an A-site disordered hexagonal Y1–xGdxInO3 (0.0 ≤ x ≤ 1.0) series synthesized by a self-assisted gel-combustion route. The phase relations show profound temperature dependence. The metastable C-type modification could be stabilized for all the compositions, which on further heating get converted to stable hexagonal polymorphs. The conversion temperature (C-type to hexagonal) was found to increase with an increase in Y3+ content. The system was observed to be single-phasic hexagonal at 1250 °C throughout the composition range. Interestingly, the increase in planar bonds of InO5 polyhedra was found to be twice that of the apical bonds on Gd3+ substitution. Careful Raman spectroscopic studies highlighted a definitive though subtle structural change from x = 0.7 onward. The same observation is also corroborated by the dielectric studies. Electric field-dependent polarization measurements showed the ferroelectric hysteresis loop for pure YInO3. The system transforms from ferroelectric in YInO3 to almost paraelectric for GdInO3. In the present study, XRD, Raman, and electrical characterizations in conjunction reveal that to tune the electrical properties of the hexagonal rare earth indates, the variation in tilting of InO5 polyhedra has to be influenced, which could not be brought about by isovalent A-site substitution

Investigation of radiation tolerance of yttria stabilized zirconia in the ballistic collision regime: Effect of grain size and environmental temperature

International audienceThe irradiation response of yttria-stabilized zirconia, having different grain sizes, subjected to 900 keV iodine ions at room temperature and 1000 K is reported. GIXRD and Raman spectroscopy indicate superior radiation tolerance of the fine-grained samples when compared to their coarse-grained counterparts which is attributed to the abundance of grain boundaries at relatively shorter distances. A reduction in the residual strain is observed in the samples irradiated at 1000 K. This is attributed to the clustering of the irradiation induced point defects thereby resulting in a decrease in their density, but with a corresponding increase in the extended defects density

Grain size effect on the radiation damage tolerance of cubic zirconia against simultaneous low and high energy heavy ions: Nano triumphs bulk

International audienceIrradiation induced damage in materials is highly detrimental and is a critical issue in several vital science and technology fields, e.g., the nuclear and space industries. While the effect of dimensionality (nano/bulk) of materials on its radiation damage tolerance has been receiving tremendous interest, studies have only concentrated on low energy (nuclear energy loss (S$_{n}$) dominant) and high energy (electronic energy loss (S$_{e}$) dominant) irradiations independently (wherein, interestingly, the effect is opposite). In-fact, research on radiation damage in general has almost entirely focused only on independent irradiations with low and/or high energy particles till date, and investigations under simultaneous impingement of energetic particles (which also correspond to the actual irradiation conditions during real-world applications) are very scarce. The present work elucidates, taking cubic zirconia as a model system, the effect of grain size (26 nm vs 80 nm) on the radiation tolerance against simultaneous irradiation with low energy (900 keV I) and high energy (27 meV Fe) particles/ions; and, in particular, introduces the enhancement in the radiation damage tolerance upon downsizing from bulk to nano dimension. This result is interpreted within the framework of the thermal-spike model after considering (1) the fact that there is essentially no spatial and time overlap between the damage events of the two ‘simultaneous’ irradiations, and (2) the influence of grain size on radiation damage against individual S$_{n}$ and S$_{e}$. The present work besides providing the first fundamental insights into how the grain size/grain boundary density inherently mediates the radiation response of a material to simultaneous S$_{n}$ and S$_{e}$ deposition, also (1) paves the way for potential application of nano-crystalline materials in the nuclear industry (where simultaneous irradiations with low and high energy particles correspond to the actual irradiation conditions), and (2) lays the groundwork for understanding the material behaviour under other simultaneous (viz. S$_{n}$ and S$_{n}$, S$_{e}$ and S$_{e}$) irradiations

Quest for lead free relaxors in YIn<SUB>1–x</SUB>Fe<SUB>x</SUB>O<SUB>3</SUB>(0.0 ≤x≤ 1.0) system: role of synthesis and structure

The B-site tailored YIn1–xFexO3 (0.0≤ x≤ 1.0) series was synthesized by glycine-aided gel-combustion technique and subjected to extensive structural and electrical investigations. The temperature had tremendous bearing on the phase evolution exhibited by the system. The entire system crystallized as C-type metastable polymorph in the as–synthesized form. Hexagonal polymorphs of Fe3+-rich compositions could be isolated by controlled heat treatment at 750 °C. Raman spectroscopic investigations showed that, while there is a general shrinkage of the lattice due to substitution of a smaller ion at In3+-site, there is an apparent dilation of the Y–O bond, and this anomaly reflects in the electrical behavior exhibited by the system. The single-phasic hexagonal nominal compositions, YIn1–xFexO3 (0.0 ≤ x ≤ 0.3), were also studied by impedance spectroscopy. The dielectric constant was found to drastically increase from 10 for YInO3 to 1000 for YIn0.7Fe0.3O3 at room temperature stressing the role of B-site tailoring on electrical behavior. More interestingly, careful substitution of Fe into YInO3 could tune the electrical behavior from a dielectric to relaxor ferroelectric in the temperature range studied. The nominal composition YIn0.7Fe0.3O3 showed a classical relaxor ferroelectric like behavior which is an important observation in context of the search for new lead free relaxor materials

Nano-cerium vanadate: a novel inorganic ion exchanger for removal of americium and uranium from simulated aqueous nuclear waste

Cerium vanadate nanopowders were synthesized by a facile low temperature co-precipitation method. The product was characterized by X-ray diffraction and transmission electron microscopy and found to consist of ∼25 nm spherical nanoparticles. The efficiency of these nanopowders for uptake of alpha-emitting radionuclides 233U (4.82 MeV α) and 241Am (5.49 MeV α, 60 keV γ) has been investigated. Thermodynamically and kinetically favorable uptake of these radionuclides resulted in their complete removal within 3 h from aqueous acidic feed solutions. The uptake capacity was observed to increase with increase in pH as the zeta potential value decreased with the increase in pH but effect of ionic strength was insignificant. Little influence of the ions like Sr2+, Ru3+, Fe3+, etc., in the uptake process indicated CeVO4 nanopowders to be amenable for practical applications. The isotherms indicated predominant uptake of the radioactive metal ions in the solid phase of the exchanger at lower feed concentrations and linear Kielland plots with positive slopes indicated favorable exchange of the metal ions with the nanopowder. Performance comparison with the other sorbents reported indicated excellent potential of nano-cerium vanadate for removing americium and uranium from large volumes of aqueous acidic solutions

Synthesis and Structural and Electrical Investigations of a Hexagonal Y_1–<i>x</i>Gd_<i>x</i>InO₃ (0.0 ≤ <i>x</i> ≤ 1.0) System Obtained via Metastable C‑Type Intermediates

Detailed structural and electrical investigations were carried out on an A-site disordered hexagonal Y_1–<i>x</i>Gd_<i>x</i>InO₃ (0.0 ≤ <i>x</i> ≤ 1.0) series synthesized by a self-assisted gel-combustion route. The phase relations show profound temperature dependence. The metastable C-type modification could be stabilized for all the compositions, which on further heating get converted to stable hexagonal polymorphs. The conversion temperature (C-type to hexagonal) was found to increase with an increase in Y³⁺ content. The system was observed to be single-phasic hexagonal at 1250 °C throughout the composition range. Interestingly, the increase in planar bonds of InO₅ polyhedra was found to be twice that of the apical bonds on Gd³⁺ substitution. Careful Raman spectroscopic studies highlighted a definitive though subtle structural change from <i>x</i> = 0.7 onward. The same observation is also corroborated by the dielectric studies. Electric field-dependent polarization measurements showed the ferroelectric hysteresis loop for pure YInO₃. The system transforms from ferroelectric in YInO₃ to almost paraelectric for GdInO₃. In the present study, XRD, Raman, and electrical characterizations in conjunction reveal that to tune the electrical properties of the hexagonal rare earth indates, the variation in tilting of InO₅ polyhedra has to be influenced, which could not be brought about by isovalent A-site substitution