Electron acceleration by a short laser beam in the presence of a long-wavelength electromagnetic wave

A scheme for laser-induced acceleration of an electron injected initially at an angle to the direction of a short-wavelength laser is investigated, where an additional long-wavelength electromagnetic wave is introduced to achieve high energy gain. Due to the beating effect of the electromagnetic waves, the electron can gain additional energy. Some computational results are presented to estimate the electron energy gain by the proposed scheme, where the gain increases by increasing the difference of the wavelengths.open9

Age-Related Incidence of Cervical Spondylosis in Residents of Jeju Island

Study DesignCervical spine radiograms of 460 Jeju islanders.PurposeTo investigate the age-matched incidences and severity of the cervical disc degeneration and associated pathologic findings.Overview of LiteratureSeveral related studies on the incidences of disc and Luschka's and facet joint degeneration have provided some basic data for clinicians.MethodsCervical radiographs of 460 (220 males and 240 females) patients in their fourth to ninth decade were analyzed. Ninety patients in their third decade were excluded because of absence of spondylotic findings.ResultsOverall incidence of cervical spondylosis was 47.8% (220 of 460 patients). The percentile incidences of spondylosis in the fourth, fifth, sixth, seventh, eighth and ninth decade was 13.2% (10 of 76 patients), 34.6% (37 of 107 patients), 58.9% (66 of 112 patients), 58.8% (50 of 85 patients), 70.3% (45 of 64 patients) and 75.0% (12 of 16 patients), respectively. The percentile incidences of one, two, three, four and five level spondylosis among 220 spondylosis patients was 45.5% (n=100), 34.1% (n=75), 15.0% (n=33), 4.5% (n=10), and 0.9% (n=2). Severity of disc degeneration ranged from ± to ++++, and was ± in 6.0% (24 segments), + in 49.6% (198 segments), ++ in 35.3% (141 segments), +++ in 9.0% (36 segments) and ++++ in 0.25% (one segment). Spurs and anterior ligament ossicle formed at the spondylotic segments, mostly at C4~6. The rate of posterior corporal spurs formation was very low. Olisthesis and ossification of the posterior longitudinal ligament were rarely combined with spondylosis. Cervical lordotic curve decreased gradually according to the progress of severity of spondylosis.ConclusionsThe incidence of cervical spondylosis and number of spondylotic segments increase, and degeneration gradually becomes more severe with age

A hybrid decision support model to discover informative knowledge in diagnosing acute appendicitis

BACKGROUND: The aim of this study is to develop a simple and reliable hybrid decision support model by combining statistical analysis and decision tree algorithms to ensure high accuracy of early diagnosis in patients with suspected acute appendicitis and to identify useful decision rules. METHODS: We enrolled 326 patients who attended an emergency medical center complaining mainly of acute abdominal pain. Statistical analysis approaches were used as a feature selection process in the design of decision support models, including the Chi-square test, Fisher's exact test, the Mann-Whitney U-test (p < 0.01), and Wald forward logistic regression (entry and removal criteria of 0.01 and 0.05, or 0.05 and 0.10, respectively). The final decision support models were constructed using the C5.0 decision tree algorithm of Clementine 12.0 after pre-processing. RESULTS: Of 55 variables, two subsets were found to be indispensable for early diagnostic knowledge discovery in acute appendicitis. The two subsets were as follows: (1) lymphocytes, urine glucose, total bilirubin, total amylase, chloride, red blood cell, neutrophils, eosinophils, white blood cell, complaints, basophils, glucose, monocytes, activated partial thromboplastin time, urine ketone, and direct bilirubin in the univariate analysis-based model; and (2) neutrophils, complaints, total bilirubin, urine glucose, and lipase in the multivariate analysis-based model. The experimental results showed that the model with univariate analysis (80.2%, 82.4%, 78.3%, 76.8%, 83.5%, and 80.3%) outperformed models using multivariate analysis (71.6%, 69.3%, 73.7%, 69.7%, 73.3%, and 71.5% with entry and removal criteria of 0.01 and 0.05; 73.5%, 66.0%, 80.0%, 74.3%, 72.9%, and 73.0% with entry and removal criteria of 0.05 and 0.10) in terms of accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under ROC curve, during a 10-fold cross validation. A statistically significant difference was detected in the pairwise comparison of ROC curves (p < 0.01, 95% CI, 3.13-14.5; p < 0.05, 95% CI, 1.54-13.1). The larger induced decision model was more effective for identifying acute appendicitis in patients with acute abdominal pain, whereas the smaller induced decision tree was less accurate with the test data. CONCLUSIONS: The decision model developed in this study can be applied as an aid in the initial decision making of clinicians to increase vigilance in cases of suspected acute appendicitis

Repeated Gene Transfection Impairs the Engraftment of Transplanted Porcine Neonatal Pancreatic Cells

BackgroundPreviously, we reported that neonatal porcine pancreatic cells transfected with hepatocyte growth factor (HGF) gene in an Epstein-Barr virus (EBV)-based plasmid (pEBVHGF) showed improved proliferation and differentiation compared to those of the control. In this study, we examined if pancreatic cells transfected repeatedly with pEBVHGF can be successfully grafted to control blood glucose in a diabetes mouse model.MethodsNeonatal porcine pancreatic cells were cultured as a monolayer and were transfected with pEBVHGF every other day for a total of three transfections. The transfected pancreatic cells were re-aggregated and transplanted into kidney capsules of diabetic nude mice or normal nude mice. Blood glucose level and body weight were measured every other day after transplantation. The engraftment of the transplanted cells and differentiation into beta cells were assessed using immunohistochemistry.ResultsRe-aggregation of the pancreatic cells before transplantation improved engraftment of the cells and facilitated neovascularization of the graft. Right before transplantation, pancreatic cells that were transfected with pEBVHGF and then re-aggregated showed ductal cell marker expression. However, ductal cells disappeared and the cells underwent fibrosis in a diabetes mouse model two to five weeks after transplantation; these mice also did not show controlled blood glucose levels. Furthermore, pancreatic cells transplanted into nude mice with normal blood glucose showed poor graft survival regardless of the type of transfected plasmid (pCEP4, pHGF, or pEBVHGF).ConclusionFor clinical application of transfected neonatal porcine pancreatic cells, further studies are required to develop methods of overcoming the damage for the cells caused by repeated transfection and to re-aggregate them into islet-like structures

Fabrication of double-ceramic-layer TBCs by suspension plasma spray

Rare-earth zirconates, such as La2Zr2O7 and Gd2Zr2O7, have been investigated as one of the candidates for replacing conventional yttria-stabilized zirconia (YSZ) for thermal barrier coating (TBC) applications at higher turbine inlet temperatures. Rare-earth zirconate oxides exhibit little phase transformation upon heating up to melting temperature as well as low thermal conductivity, where as their mechanical properties is inferior to those of YSZ TBCs. Double-ceramic-layer (DCL) TBCs have been investigated in order to take advantage of beneficial characteristics of both YSZ and rare-earth zirconate. In this study, the fabrication of DCL-TBCs with YSZ layer and rare-earth-zirconate top layer by using suspension plasma spray are reported. Microstructure, compositional profile, thermal conductivity, and thermal durability of DCL-TBCs are characterized. The usefulness of these DCL-TBCs is also discussed

Gain-Scheduled Complementary Filter Design for a MEMS Based Attitude and Heading Reference System

This paper describes a robust and simple algorithm for an attitude and heading reference system (AHRS) based on low-cost MEMS inertial and magnetic sensors. The proposed approach relies on a gain-scheduled complementary filter, augmented by an acceleration-based switching architecture to yield robust performance, even when the vehicle is subject to strong accelerations. Experimental results are provided for a road captive test during which the vehicle dynamics are in high-acceleration mode and the performance of the proposed filter is evaluated against the output from a conventional linear complementary filter

Contrast Echo-A Simple Diagnostic Tool for a Coronary Artery Fistula

Coronary artery fistulas have been diagnosed with aortography, coronary angiography, and coronary computed tomography (CT). A large fistula can be occasionally found as a mass lesion on echocardiography but cannot be easily confirmed. Here, we report a new diagnostic approach to coronary artery fistulas using a contrast agent and transthoracic echocardiography. Transthoracic echocardiography of a 46-year-old female suffering from dyspnea revealed suspicious small turbulent flow in the main pulmonary artery. Following infusion of a contrast agent, we found whitish flow in the main pulmonary artery during the diastolic phase, and aortic CT revealed two huge right coronary artery fistulas in the main pulmonary artery. A simple diagnostic approach to a coronary artery fistula using contrast agent helped us confirm the diagnosis because of the typical diastolic whitish flow in the pulmonary artery