Asymptotic stability of traveling waves for viscous scalar conservation laws

Department of Mathematical ScienceThere are many research about Viscous scalar conservation law $u_{t}+f(u)_{x}=\mu u_{xx}$. In this paper, we study stability and asymptotic stability of travelling solutions for viscous scalar conservation law. The major result shows that if Rankine Hugoniot condition, the generalized shock condition and some assumptions hold, there exist a solution approaches to the travelling solution, satisfy stability and asymptotic stability problems at corresponding rate. The important feature of this paper is to employ an appropriate weight function to show the stability and asymptotic behavior of the viscous shock waves.ope

Liquid Crystal Elastomer Waveguide Actuators

While most photomechanical materials developed to date have relied on free‐space illumination to drive actuation, this strategy fails when direct line‐of‐site access is precluded. In this study, waveguided light is harnessed by liquid crystal elastomer (LCE) nanocomposites to drive actuation. Using photo‐chemical reduction of gold salts to plasmonic nanoparticles, prescription of photoresponsive regions within fibers of mono‐domain LCEs is demonstrated with control over both the location along the fiber axis, as well as in the azimuthal direction. Due to localized photothermal heating provided by plasmonic absorption of waveguided light and resulting inhomogeneous thermally induced deformation of the LCE, reversible bending along multiple axes is demonstrated

Ectopic Pancreas with Hemorrhagic Cystic Change in the Anterior Mediastinum

A 31-year-old female was referred from other hospital due to migrating chest pain, mild cough, and blood-tinged sputum for three days before admission. Laboratory tests were unremarkable. Chest computed tomography revealed an elliptical necrotic mass at the left anterior mediastinum, measuring 7×3×4 cm. With the impression of mediastinal abscess or loculated empyema, thoracoscopic resection was performed. There was severe pleural adhesion around the mass. The mass could be resected by the wedge resection of the adhesed upper lobe tissue of left lung around the mass. Final pathologic diagnosis was ectopic pancreas

Blueprinting Photothermal Shape-Morphing of Liquid Crystal Elastomers

Liquid crystal elastomers (LCEs) are an attractive platform for dynamic shape‐morphing due to their ability to rapidly undergo large deformations. While recent work has focused on patterning the director orientation field to achieve desired target shapes, this strategy cannot be generalized to material systems where high‐resolution surface alignment is impractical. Instead of programming the local orientation of anisotropic deformation, an alternative strategy for prescribed shape‐morphing by programming the magnitude of stretch ratio in a thin LCE sheet with constant director orientation is developed here. By spatially patterning the concentration of gold nanoparticles, uniform illumination leads to gradients in photothermal heat generation and therefore spatially nonuniform deformation profiles that drive out‐of‐plane buckling of planar films into predictable 3D shapes. Experimentally realized shapes are shown to agree closely with both finite element simulations and geometric predictions for systems with unidirectional variation in deformation magnitude. Finally, the possibility to achieve complex oscillatory motion driven by uniform illumination of a free‐standing patterned sheet is demonstrated

Development and assessment of a hand assist device: GRIPIT

Background Although various hand assist devices have been commercialized for people with paralysis, they are somewhat limited in terms of tool fixation and device attachment method. Hand exoskeleton robots allow users to grasp a wider range of tools but are heavy, complicated, and bulky owing to the presence of numerous actuators and controllers. The GRIPIT hand assist device overcomes the limitations of both conventional devices and exoskeleton robots by providing improved tool fixation and device attachment in a lightweight and compact device. GRIPIT has been designed to assist tripod grasp for people with spinal cord injury because this grasp posture is frequently used in school and offices for such activities as writing and grasping small objects. Methods The main development objective of GRIPIT is to assist users to grasp tools with their own hand using a lightweight, compact assistive device that is manually operated via a single wire. GRIPIT consists of only a glove, a wire, and a small structure that maintains tendon tension to permit a stable grasp. The tendon routing points are designed to apply force to the thumb, index finger, and middle finger to form a tripod grasp. A tension-maintenance structure sustains the grasp posture with appropriate tension. Following device development, four people with spinal cord injury were recruited to verify the writing performance of GRIPIT compared to the performance of a conventional penholder and handwriting. Writing was chosen as the assessment task because it requires a tripod grasp, which is one of the main performance objectives of GRIPIT. Results New assessment, which includes six different writing tasks, was devised to measure writing ability from various viewpoints including both qualitative and quantitative methods, while most conventional assessments include only qualitative methods or simple time measuring assessments. Appearance, portability, difficulty of wearing, difficulty of grasping the subject, writing sensation, fatigability, and legibility were measured to assess qualitative performance while writing various words and sentences. Results showed that GRIPIT is relatively complicated to wear and use compared to a conventional assist device but has advantages for writing sensation, fatigability, and legibility because it affords sufficient grasp force during writing. Two quantitative performance factors were assessed, accuracy of writing and solidity of writing. To assess accuracy of writing, we asked subjects to draw various figures under given conditions. To assess solidity of writing, pen tip force and the angle variation of the pen were measured. Quantitative evaluation results showed that GRIPIT helps users to write accurately without pen shakes even high force is applied on the pen. Conclusions Qualitative and quantitative results were better when subjects used GRIPIT than when they used the conventional penholder, mainly because GRIPIT allowed them to exert a higher grasp force. Grasp force is important because disabled people cannot control their fingers and thus need to move their entire arm to write, while non-disabled people only need to move their fingers to write. The tension-maintenance structure developed for GRIPIT provides appropriate grasp force and moment balance on the users hand, but the other writing method only fixes the pen using friction force or requires the users arm to generate a grasp force

A Spinal Cord Astrocytoma and Its Concurrent Osteoblastic Metastases at the Time of the Initial Diagnosis: a Case Report and Literature Review

Bone metastasis from a spinal cord astrocytoma has been reported only twice in the English medical literature. It is generally known that bone metastasis is found after the initial diagnosis with/without intervening surgery rather than being found at the time of the diagnosis of astrocytoma. The purpose of this article is to report for the first time a case of concurrent bone metastasis from a spinal cord astrocytoma at the time of diagnosing the spinal cord astrocytoma

Preoperative Radiologic and Postoperative Pathologic Risk Factors for Early Intra-Hepatic Recurrence in Hepatocellular Carcinoma Patients Who Underwent Curative Resection

PURPOSE: The risk of hepatocellular carcinoma (HCC) recurrence must be considered ahead of surgery. This study was undertaken to identify pre-operative risk factors for early intrahepatic recurrence of HCC after curative resection in a large-scale. MATERIALS AND METHODS: We retrospectively reviewed the preoperative three-phase multi-detector CT (MDCT) and laboratory data for 240 HCC patients who underwent curative resection; tumor size, number, gross shape, capsule integrity, distinctiveness of tumor margin, portal vein thrombosis (PVT), alpha-fetoprotein level (AFP), and protein induced by vitamin K absence-II (PIVKA-II) levels were assessed. Surgical pathology was reviewed; tumor differentiation, capsule, necrosis, and micro-vessel invasion were recorded. RESULTS: HCC recurred in 61 patients within six months (early recurrence group), but not in 179 patients (control group). In univariate analysis, large tumor size (p = 0.018), shape (p = 0.028), poor capsule integrity (p = 0.046), elevated AFP (p = 0.015), and PIVKA-II (p = 0.008) were significant preoperative risk factors. Among the pathologic features, PVT (p = 0.023), Glisson's capsule penetration (p = 0.033), microvascular invasion (p < 0.001), and poor differentiation (p = 0.001) showed statistical significance. In multivariate analysis, only the histopathologic parameters of microvascular invasion and poor differentiation achieved statistical significance. CONCLUSION: Preoperative CT and laboratory parameters showed limited value, while the presence of microscopic vascular tumor invasion and poorly differentiated HCC correlated with higher risk of early recurrence after curative resection.ope

Analysis of the hump phenomenon and needle defect states formed by driving stress in the oxide semiconductor

The reduction in current ability accompanied by the hump phenomenon in oxide semiconductor thin-film transistors to which high DC voltages and AC drive voltages are applied has not been studied extensively, although it is a significant bottleneck in the manufacture of integrated circuits. Here, we report on the origin of the hump and current drop in reliability tests caused by the degradation in the oxide semiconductor during a circuit driving test. The hump phenomenon and current drop according to two different driving stresses were verified. Through a numerical computational simulation, we confirmed that this issue can be caused by an additional “needle”, a shallow (~0.2 eV) and narrow (&lt;0.1 eV), defect state near the conduction band minimum (CBM). This is also discussed in terms of the dual current path caused by leakage current in the channel edge. © 2019, The Author(s).1