Effective data parallel computing on multicore processors

The rise of chip multiprocessing or the integration of multiple general purpose processing cores on a single chip (multicores), has impacted all computing platforms including high performance, servers, desktops, mobile, and embedded processors. Programmers can no longer expect continued increases in software performance without developing parallel, memory hierarchy friendly software that can effectively exploit the chip level multiprocessing paradigm of multicores. The goal of this dissertation is to demonstrate a design process for data parallel problems that starts with a sequential algorithm and ends with a high performance implementation on a multicore platform. Our design process combines theoretical algorithm analysis with practical optimization techniques. Our target multicores are quad-core processors from Intel and the eight-SPE IBM Cell B.E. Target applications include Matrix Multiplications (MM), Finite Difference Time Domain (FDTD), LU Decomposition (LUD), and Power Flow Solver based on Gauss-Seidel (PFS-GS) algorithms. These applications are popular computation methods in science and engineering problems and are characterized by unit-stride (MM, LUD, and PFS-GS) or 2-point stencil (FDTD) memory access pattern. The main contributions of this dissertation include a cache- and space-efficient algorithm model, integrated data pre-fetching and caching strategies, and in-core optimization techniques. Our multicore efficient implementations of the above described applications outperform nai¨ve parallel implementations by at least 2x and scales well with problem size and with the number of processing cores

Biodegradable magnesium alloy (WE43) in bone-fixation plate and screw

The purpose of the present study was to evaluate the mechanical strength and the absorption rate of WE43 material and to develop an absorbable metallic plate and screw for craniofacial application. The extruded WE43 plate and screw were evaluated using a LeFort I osteotomy canine model of 10 beagle dogs. Animals were divided into two groups: five dogs in the experimental group and five dogs in the control group. mu CT was acquired at 4, 12, and 24 weeks. At 24 weeks after the operation, all animals were sacrificed, and histologic evaluation was performed. Swelling and gas formation were observed in three dogs in the experimental groups at 8 weeks. From 12 weeks, infraorbital fistula and inflammation were observed in three dogs in the experimental group, which gradually decreased and disappeared at 24 weeks. Other two dogs showed less gas formation at 12 weeks. The plates were completely absorbed, and gas formation was not observed at 24 weeks in these two dogs. New bone was well formed around the plates and screws in both groups. Histologic examination showed no specific differences between two groups. The mechanical strength of extruded WE43 was sufficient for mid-facial application. Plates and screws made with appropriately treated WE43 have the potential to be useful clinically.N

Vacancy driven surface disorder catalyzes anisotropic evaporation of ZnO (0001) polar surface

The evaporation and crystal growth rates of ZnO are highly anisotropic and are fastest on the Zn-terminated ZnO (0001) polar surface. Herein, we study this behavior by direct atomic-scale observations and simulations of the dynamic processes of the ZnO (0001) polar surface during evaporation. The evaporation of the (0001) polar surface is accelerated dramatically at around 300 °C with the spontaneous formation of a few nanometer-thick quasi-liquid layer. This structurally disordered and chemically Zn-deficient quasi-liquid is derived from the formation and inward diffusion of Zn vacancies that stabilize the (0001) polar surface. The quasi-liquid controls the dissociative evaporation of ZnO with establishing steady state reactions with Zn and O$_{2}$ vapors and the underlying ZnO crystal; while the quasi-liquid catalyzes the disordering of ZnO lattice by injecting Zn vacancies, it facilitates the desorption of O$_{2}$ molecules. This study reveals that the polarity-driven surface disorder is the key structural feature driving the fast anisotropic evaporation and crystal growth of ZnO nanostructures along the [0001] direction

Allopurinol-induced DRESS syndrome mimicking biliary obstruction

An 84-year-old man was admitted to our hospital with fever, jaundice, and itching. He had been diagnosed previously with chronic renal failure and diabetes, and had been taking allopurinol medication for 2 months. A physical examination revealed that he had a fever (38.8℃), jaundice, and a generalized maculopapular rash. Azotemia, eosinophilia, atypical lymphocytosis, elevation of liver enzymes, and hyperbilirubinemia were detected by blood analysis. Magnetic resonance cholangiography revealed multiple cysts similar to choledochal cysts in the liver along the biliary tree. Obstructive jaundice was suspected clinically, and so an endoscopic ultrasound examination was performed, which ruled out a diagnosis of obstructive jaundice. The patient was diagnosed with DRESS (Drug Rash with Eosinophilia and Systemic Symptoms) syndrome due to allopurinol. Allopurinol treatment was stopped and steroid treatment was started. The patient died from cardiac arrest on day 15 following admission