Hydrostatic pressure effects on superconducting transition of nanostructured niobium highly strained by high-pressure torsion

We study the effects of hydrostatic pressure (HP) compression on the superconducting transition of severely strained Nb samples, whose grain sizes are reduced to the submicrometer level. Engineered granularity by high-pressure torsion (HPT) treatment changes the strength of coupling between submicrometer-scale grains and introduces lattice strain. We attempt to utilize the initially accumulated shear strain in the starting material for increasing the superconducting transition temperature Tc under HP compression. The HP effects on non-strained Nb have already been investigated in the pressure regime over 100 GPa by Struzhkin et al. [Phys. Rev. Lett. 79, 4262 (1997)], and Tc reportedly exhibited an increase from 9.2 to 9.9 K at approximately 10 GPa. (1) Slightly strained Nb in the HPT treatment exhibits the increase in Tc under HP due to the strengthening of the intergrain coupling, so the pressure scale of the pressure response observed by Struzhkin et al. is reduced to approximately one-seventh at the maximum. (2) Prominently strained Nb in the HPT treatment exhibits the increase in Tc under HP due to a reduction in structural symmetry at the unit-cell level: In a Nb sample subjected to HPT (6 GPa, 10 revolutions), Tc exceeds 9.9 K at approximately 2 GPa. According to our first-principle calculations, the reduction in the structural symmetry affords an increase in the density of states at the Fermi energy, thereby yielding a prominent increase in Tc at low pressures

Squamous Cell Carcinoma Developing from a Testicular Epidermal Cyst: A Case Report and Literature Review

A 50-year-old Japanese man with a two-year history of a painless right scrotal mass visited our hospital. Considering laboratory findings and computed tomography, the patient was diagnosed with an uncharacteristic testicular tumor. No metastases were present on radiographic study at the first visit. Emergent high radical orchiectomy was performed, and the tumor was identified as a squamous cell carcinoma (SCC) of a testicular epidermal cyst. He is alive without recurrence or metastasis six months after surgery. Testicular SCC is an extremely rare tumor. This is the third case of testicular SCC associated with an epidermal cyst in English literature

Dynamic observation of a damping material using micro X-ray computed tomography coupled with a phase-locked loop

As rubber materials are used for damping, clarifying the relationship between the loss factor and microstructure would help develop high-performance damping materials. Although nondestructive observations using X-ray computed tomography (CT) under repetitive deformation have been reported, no observations have been reported at the submicron order that capture low-strain deformation, such as vibration exposure. The internal deformation behavior of materials with different loss factors has not yet been evaluated. This study proposes a dynamic X-ray CT method for specimens under tensile amplitudes, directly evaluating the internal deformation behavior of materials under dynamic conditions. The proposed 4D-CT has an excitation of 1 Hz and a spatial resolution of 0.5 μm. The local strain was obtained from X-ray CT at each phase, and the deformation behavior was evaluated. The results revealed that the peak of the local strain amplitude distribution curve decreased and the distribution widened as fine particles were mixed

Continuous infusion of lipo-prostaglandin E1 for Takayasu’s arteritis with heart failure in an 11-month-old baby: a case report

Abstract Background Takayasu’s arteritis is extremely rare in children aged below 6 years. At the onset of Takayasu’s arteritis in children, symptoms are varied but differ from those in adults. Corticosteroids are the mainstay of treatment for preventing irreversible vascular damage but there is no standard treatment for progressive vascular stenosis. Case presentation A Japanese 11-month-old baby boy presented with Takayasu’s arteritis and heart failure, possibly due to afterload mismatch caused by high blood pressure. Computed tomography was performed and revealed thoracic and abdominal aortic aneurysms. It also revealed severe celiac artery stenosis and bilateral renal artery stenosis. Prednisolone was initiated as first-line therapy. The fever resolved, and C-reactive protein levels returned to normal. Although his general condition improved, deterioration of vascular lesions was evident. Celiac artery occlusion, severe right renal artery stenosis, and new superior mesenteric artery stenosis were observed. We decided to use a continuous infusion of lipo-prostaglandin E1 for prevention of branch stenosis of his abdominal aorta. The progression of vascular stenosis was stopped and our patient’s cardiac function gradually improved. Conclusions A differential diagnosis of heart failure with high blood pressure should be considered in babies. The progression of vascular stenosis may be suppressed by lipo-prostaglandin E1