Heat conduction of single-walled carbon nanotube isotope-superlattice structures: A molecular dynamics study

Heat conduction of single-walled carbon nanotubes (SWNTs) isotope-superlattice is investigated by means of classical molecular dynamics simulations. Superlattice structures were formed by alternately connecting SWNTs with different masses. On varying the superlattice period, the critical value with minimum effective thermal conductivity was identified, where dominant physics switches from zone-folding effect to thermal boundary resistance of lattice interface. The crossover mechanism is explained with the energy density spectra where zone-folding effects can be clearly observed. The results suggest that the critical superlattice period thickness depends on the mean free path distribution of diffusive-ballistic phonons. The reduction of the thermal conductivity with superlattice structures beats that of the one-dimensional alloy structure, though the minimum thermal conductivity is still slightly higher than the value obtained by two-dimensional random mixing of isotopes.Comment: 7 Pages, 5 figures, accepted to Phys. Rev.

Gingival Nikolsky’s Sign: A Valuable Tool in Identifying Oral Manifestations of Mucous Membrane Pemphigoid and Pemphigus Vulgaris

Autoimmune bullous diseases are a group of rare, chronic blistering diseases that affects the skin and mucous membranes. Mucous membrane pemphigoid (MMP) is the most frequently occurring autoimmune bullous disease in the oral cavity, followed by pemphigus vulgaris (PV). Early diagnosis of MMP or PV is critical for proper management and prevention of potential serious complications. This study was based on a retrospective review of 39 cases that were classified as MMP (25 patients) or PV (14 patients). Nikolsky’s sign characterized by epithelial detachment as a result of slight pressure or rubbing the oral mucosa is a simple test that can confirm the existence of gingival desquamation. A positive reaction was confirmed in 38 patients (97.4%) at their first visit. This result indicates that patients showing positive Nikolsky’s sign should include MMP or PV in the differential diagnosis and, in that case, histopathological examination and direct immunofluorescence testing are critical to establish the final diagnosis. For the early diagnosis of autoimmune bullous disorders, oral healthcare providers should consider the use of the test for Nikolsky’s sign that may ultimately lead to the early diagnosis of MMP and PV or other diseases or disorders

Desquamative Gingivitis: Early Sign of Mucous Membrane Pemphigoid and Pemphigus Vulgaris

Early signs and symptoms of autoimmune bullous diseases such as mucous membrane pemphigoid (MMP) or pemphigus vulgaris (PV) develop in the oral cavity in almost all cases. Desquamative gingivitis (DG) is a clinical manifestation common to several diseases or disorders and is frequently associated with autoimmune bullous diseases. This is a retrospective study of 37 patients with MMP (24 cases) or PV (13 cases) including 10 males and 27 females with a mean age of 58.4 years. The study indicates that DG is an early sign of autoimmune bullous diseases such as MMP or PV. About 70.3% of the oral lesions were confined only to the gingiva, and DG was the only manifestation of the diseases. Since some lesions remain limited to the oral cavity for a long period of time, patients diagnosed with MMP or PV should be closely followed because they must be immediately referred to other experts when they develop lesions on parts of their body other than the oral cavity. The oral healthcare provider should collaborate with other healthcare experts including dermatologists, ophthalmologists, and otolaryngologists to evaluate and manage patients with autoimmune bullous diseases in the oral cavity

Hereditary Spherocytosis Coexisting with UDP-Glucuronosyltransferase Deficiency Highly Suggestive of Crigler-Najjar Syndrome Type II

Patients with co-existing hereditary spherocytosis (HS) and UDP-glucuronosyltransferase 1A1 (UGT1A1) deficiency as Gilbert's syndrome (GS) have been reported, and previous studies have demonstrated an increased risk for developing gallstones in patients with co-inheritance of GS and HS. We experienced an interesting case of HS showing persistent jaundice after splenectomy, and upon further evaluation, the 25-year-old female patient was found to have HS combined with UGT1A1 deficiency. Sequence analysis of the UGT1A1 gene revealed that she was a compound heterozygote with p.[G71R; Y486D] + [Y486D] mutations, which suggests Crigler-Najjar syndrome type II rather than GS. Careful evaluation of inappropriately elevated bilirubin level compared with the degree of hemolysis is important, reflecting the therapeutic implication of splenectomy and cholecystectomy

High energy electron observation by Polar Patrol Balloon flight in Antarctica

We accomplished a balloon observation of the high-energy cosmic-ray electrons in 10-1000GeV to reveal the origin and the acceleration mechanism. The observation was carried out for 13 days at an average altitude of 35km by the Polar Patrol Balloon (PPB) around Antarctica in January 2004. The detector is an imaging calorimeter composed of scintillating-fiber belts and plastic scintillation counters sandwiched between lead plates. The geometrical factor is about 600cm^2sr, and the total thickness of lead absorber is 9 radiation lengths. The performance of the detector has been confirmed by a test flight at the Sanriku Balloon Center and by an accelerator beam test using the CERN-SPS (Super Proton Synchrotron at CERN). The new telemetry system using the Iridium satellite, the power system supplied by solar panels and the automatic flight level control operated successfully during the flight. We collected 5.7×10^3 events over 100GeV, and selected the electron candidates by a preliminary data analysis of the shower images. We report here an outline of both detector and observation, and the first result of the electron energy spectrum over 100GeV obtained by an electronic counter