Exceptionally gigantic aurora in the polar cap on a day when the solar wind almost disappeared.

Revealing the origins of aurorae in Earth's polar cap has long been a challenge since direct precipitation of energetic electrons from the magnetosphere is not always expected in this region of open magnetic field lines. Here, we introduce an exceptionally gigantic aurora filling the entire polar cap region on a day when the solar wind had almost disappeared. By combining ground-based and satellite observations, we proved that this unique aurora was produced by suprathermal electrons streaming directly from the Sun, which is known as "polar rain." High-sensitivity imaging from the ground has visualized complex spatial structures of the polar rain aurora possibly manifesting the internal pattern of the solar wind or even the organizations in the chromosphere of the Sun.

Simulation study of the harmonic structure of lower hybrid waves driven by energetic ions.

By means of one-dimensional, electromagnetic, particle-in-cell simulations considering the effects of energetic-ion injection, we study the harmonic structure of lower hybrid waves (LHWs) driven by energetic ions under the condition where the electron plasma frequency (ω_{pe}) is smaller than the electron cyclotron frequency (Ω_{e}). It is found that after the LHWs are excited with the wave number and frequency of (k_{1},ω_{1}), many harmonic LHWs are generated at (mk_{1},nω_{1}) where m and n are integers, up to far beyond the lower hybrid resonance frequency, m and n∼10. We show that the harmonic LHWs are generated by nonlinear wave-wave coupling between the LHWs directly excited by the energetic ions and the energetic-ion cyclotron waves above the lower hybrid resonance frequency. We also find that the harmonic LHWs can exist even after the energetic ions are artificially removed because they can be coupled with ion Bernstein waves due to bulk ions. The effect of the energetic-ion injection and the dependence of ω_{pe}/Ω_{e} on the development of the harmonic LHWs are investigated to compare the simulation results with an observation in Earth's magnetosphere.

Rapidly growing double cancer of the gallbladder: A case report.

INTRODUCTION: Gallbladder cancer is a rare malignancy and double cancer of the gallbladder is extremely rare. Biliary tree malignancies including cholangiocarcinoma and gallbladder cancer are aggressive cancers and have a poor prognosis. This reports a rare case of double adenocarcinoma of the gallbladder. PRESENTATION OF CASE: A 77-year old woman with a cholelithiasis and decreased body weight was diagnosed with rapidly growing gallbladder tumor by abdominal computed tomography scan. A combined resection of the gallbladder, extrahepatic bile duct, segments 4a and 5 of the liver and regional lymph node dissection were performed. Pathologic examination revealed double poorly differentiated adenocarcinoma of the gallbladder. The patient had no evidence of recurrence for 40 months after resection. DISCUSSION: This patient had double cancer of the gallbladder. Gallbladder cancer is an aggressive cancer and has a poor prognosis. The only curative therapy is radical resection. In this patient, radical laparotomy and adjuvant chemotherapy were performed. The pathological diagnosis of the resected specimen was double cancer of the gallbladder. CONCLUSION: This is a report of rapidly growing double cancer of the gallbladder. Patients with gallbladder cancer may benefit from aggressive surgical resection and adjuvant chemotherapy.

Simultaneous laparoscopic treatment of median arcuate ligament syndrome and segmental adenomyomatosis of the gallbladder: A case report.

INTRODUCTION: Median Arcuate Ligament Syndrome (MALS) is a condition in which the median arcuate ligament tightly compresses the celiac artery. A patient presented with MALS and segmental adenomyomatosis of the gallbladder, both treated simultaneously using a laparoscopic approach. PRESENTATION OF CASE: A 48-year-old male with adenomyomatosis of the gallbladder presented with postprandial epigastric pain. Abdominal three-dimensional computed tomography scan showed compression of the celiac artery, and the patient was diagnosed with MALS. Laparoscopic dissection of the median arcuate ligament and cholecystectomy were performed to treat both conditions. By optimizing port positions, both conditions could be treated simultaneously. The patient was discharged on postoperative day 6 and has no recurrent symptoms 20 months postoperatively. DISCUSSION: To the best of our knowledge, there are no previously reported cases of simultaneous laparoscopic division of the median arcuate ligament and cholecystectomy. CONCLUSION: By optimizing the port positions, laparoscopic division of the median arcuate ligament and cholecystectomy were performed simultaneously, minimally invasively, safely and effectively.

One-way flow over uniformly heated U-shaped bodies driven by thermal edge effects.

The thermal edge flow is a gas flow typically induced near a sharp edge (or a tip) of a uniformly heated (or cooled) flat plate. This flow has potential applicability as a nonmechanical pump or flow controller in microelectromechanical systems (MEMS). However, it has a shortcoming: the thermal edge flows from each edge cancel out, resulting in no net flow. In this study, to circumvent this difficulty, the use of a U-shaped body is proposed and is examined numerically. More specifically, a rarefied gas flow over an array of U-shaped bodies, periodically arranged in a straight channel, is investigated using the direct simulation Monte-Carlo (DSMC) method. The U-shaped bodies are kept at a uniform temperature different from that of the channel wall. Two types of U-shaped bodies are considered, namely, a square-U shape and a round-U shape. It is demonstrated that a steady one-way flow is induced in the channel for both types. The mass flow rate is obtained for a wide range of the Knudsen numbers, i.e., the ratio of the molecular mean free path to the characteristic size of the U-shape body. For the square-U type, the direction of the overall mass flow is in the same direction for the entire range of the Knudsen numbers investigated. For the round-U type, the direction of the total mass flux is reversed when the Knudsen number is moderate or larger. This reversal of the mass flow rate is attributed to a kind of thermal edge flow induced over the curved part of the round-U-shaped body, which overwhelms the thermal edge flow induced near the tip. The force acting on each of the bodies is also investigated.

Switching between laser-induced thermophoresis and thermal convection of liquid suspension in a microgap with variable dimension.

Phoretic motion of particles along a temperature gradient formed in a fluid, known as thermophoresis, often takes place under the influence of bulk motion caused by thermal convection. In this paper, using a laser heating method, the significance of two competing effects, that is, thermophoresis and thermal convection, for the particle transport in a liquid phase confined in a microgap is investigated experimentally by changing the gap size as a control parameter. It is found that there is a threshold of the gap size, above which the particles tend to accumulate around the heated spot, forming a ring-like particle distribution. On the contrary, if the gap size is below the threshold, the particles are depleted from the heated spot. Switching between these accumulation and depletion modes is expected to develop novel manipulation techniques.

Ascending Colon Schwannoma Surgically Treated after Accurate Preoperative Diagnosis.

Colorectal schwannomas are rare and usually benign gastrointestinal mesenchymal tumors. However, these tumors are often overtreated, possibly owing to misleading malignant potential. To our knowledge, there have been no previous reports of ascending colon schwannoma preoperatively diagnosed as benign schwannoma. Herein, we report a case of ascending colon schwannoma accurately diagnosed by endoscopic biopsy and successfully treated by wedge resection. The patient was a 76-year-old woman with complaints of bloody stool. She had no relevant past medical history. Radiological findings revealed a protruded mass in the ascending colon, and colonoscopy revealed a submucosal tumor measuring approximately 3 cm in diameter with a reddish and uneven surface. Histological and immunohistochemical analysis for vimentin and S100 protein of the specimen obtained by endoscopic biopsy confirmed the diagnosis of schwannoma. Thus, we performed laparoscopy-assisted endoscopic full-thickness resection of the ascending colon wall, as appropriate for a benign soft tissue tumor. The postoperative course has been uneventful for 2 years. This case demonstrates that colonic schwannoma can be successfully treated with adequate resection if an accurate preoperative diagnosis is made, thereby avoiding overtreatment, such as surgery for colorectal tumor including lymph node dissection. Preoperatively diagnosed schwannomas should be treated by wedge resection, with postoperative pathological findings confirming the presence or absence of malignancy. Additional resection should be considered for very rare cases of coexisting malignant tissue.

Motion of an array of plates in a rarefied gas caused by radiometric force.

In a rarefied gas in an infinitely long channel between two parallel plates, an array of infinitely many plates, arranged longitudinally with uniform interval, is placed along the channel. The array is assumed to be freely movable along the channel. If one side of each plate is heated, the radiometric force acts on it, and the array starts moving toward the cold sides of the plates. The final steady motion of the array, as well as the corresponding behavior of the gas, is investigated numerically on the basis of kinetic theory using the ellipsoidal statistical model of the Boltzmann equation. As the solution method, a finite-difference method, with a method of characteristics incorporated, that is able to capture the discontinuity in the velocity distribution function is employed. As the result, the local flow field near the edges of the plates and the terminal velocity of the array are obtained accurately for relatively small Knudsen numbers.

Vacuum formation behind the expansion wave in a piston motion problem.

Long time behavior of one-dimensional gas motion caused by pulling a piston with a high speed is numerically studied on the basis of the kinetic theory of gases. It is clarified that (i) if the piston speed is lower than a critical speed, the state of the gas time-asymptotically approaches the local equilibrium that corresponds to the isentropic solution in the conventional gas dynamics, namely, an expansion wave followed by a uniform state, and (ii) otherwise, there appears a highly nonequilibrium region with a very low pressure behind the expansion tail. In the latter case, the components of temperature parallel and perpendicular to the flow direction become highly different, and the density tends to vanish as time goes on, forming a vacuum region behind the tail at the infinite time.

Extravascular papillary endothelial hyperplasia of the palm masquerading as an angiosarcoma.

Cutaneous extravascular papillary endothelial hyperplasia (PEH) is a rare lesion presenting as a cutaneous mass and histologically mimicking angiosarcoma. Herein, we describe a patient who presented with a palm tumor that had developed after trauma. Histologically, the lesion was ulcerated and showed proliferation of atypical epithelioid cells with nuclear enlargement and mitosis. Vascular proliferation was evident, and these were positive for CD31 and CD34, with approximately 20% positivity for MIB-1. We diagnosed this case as an extravascular papillary endothelial hyperplasia because there was no evidence of invasion into the surrounding tissue and elastica staining proved it did not have a vascular structure. To our knowledge, cutaneous extravascular PEH has not yet been reported in the published work.

Facile formation of water-insoluble cyclodextrin/Nafion composite films on solid surfaces.

The water-insoluble poly-beta-cyclodextrin (poly-CD)/Nafion composite film was easily prepared by casting a mixed solution of poly-CD and Nafion onto substrate plates. FT-IR measurements showed that the 50/50 wt% poly-CD/Nafion composite film remained stable on the glass and quartz substrates after immersion in water for more than 3 h, while a pure poly-CD film was almost completely dissolved by immersion within 1 h. The film stability was also evaluated from the amount of p-nitrophenol (p-NP) inclusion in the film, which was determined from the decrease in UV-vis absorbance of the p-NP solution into which the film was immersed. The composition dependence of the inclusion amount showed that the film was stable up to 50 wt% CD, but became less stable with further increase in the CD concentration in the film. From the isotherms for the inclusion of p-NP and 1-naphthoate (1-Naph) into the film, the inclusion (stability) constants were determined to be 3.7x10(3) M(-1) and 1.9x10(2) M(-1), respectively. These results show that the selective inclusion of CD is retained after preparation of the composite film.