Direct Monte Carlo Simulation of kV Electron Scattering Processes-N(E) Spectra for Aluminum

A Monte Carlo simulation of the scattering processes of kV electrons penetrating into aluminum was performed. The simulation is based on the use of different types of differential cross-sections for individual elastic and inelastic scattering: (i) the differential cross-sections derived by the partial wave expansion method for elastic scattering, (ii) Gryzinski\u27s excitation function for inner-shell electron excitation, (iii) Streitwolf\u27s excitation function for conduction electron excitation, (iv) Quinn\u27s mean free path for plasmon excitation. The main purpose of this work is to see how accurately the present direct Monte Carlo simulation describes the backscattered electrons from Al, which is the most important factor for making quantitative Auger electron spectroscopy more reliable. The calculations were done for incident electron energies of 1.5 and 3 keV at angles of incidence 0° (normal) and 45°, respectively. Experiments were also performed using two Auger Scanning Electron Microscopes (SEM) JAMP-10 (for normal incidence) and JAMP-3 (for 45° incidence) to verify the theoretical calculations with comparison of N(E)-spectra. The results show satisfactory agreement between theory and experiment. This suggests that the present direct Monte Carlo simulation describes the scattering processes of kV electrons in aluminum and the background intensity in Auger electron spectroscopy with considerable accuracy

Integration of enzyme activities into metabolic flux distributions by elementary mode analysis

<p>Abstract</p> <p>Background</p> <p>In systems biology, network-based pathway analysis facilitates understanding or designing metabolic systems and enables prediction of metabolic flux distributions. Network-based flux analysis requires considering not only pathway architectures but also the proteome or transcriptome to predict flux distributions, because recombinant microbes significantly change the distribution of gene expressions. The current problem is how to integrate such heterogeneous data to build a network-based model.</p> <p>Results</p> <p>To link enzyme activity data to flux distributions of metabolic networks, we have proposed Enzyme Control Flux (ECF), a novel model that integrates enzyme activity into elementary mode analysis (EMA). ECF presents the power-law formula describing how changes in enzyme activities between wild-type and a mutant are related to changes in the elementary mode coefficients (EMCs). To validate the feasibility of ECF, we integrated enzyme activity data into the EMCs of <it>Escherichia coli </it>and <it>Bacillus subtilis </it>wild-type. The ECF model effectively uses an enzyme activity profile to estimate the flux distribution of the mutants and the increase in the number of incorporated enzyme activities decreases the model error of ECF.</p> <p>Conclusion</p> <p>The ECF model is a non-mechanistic and static model to link an enzyme activity profile to a metabolic flux distribution by introducing the power-law formula into EMA, suggesting that the change in an enzyme profile rather reflects the change in the flux distribution. The ECF model is highly applicable to the central metabolism in knockout mutants of <it>E. coli </it>and <it>B. subtilis</it>.</p

Dynamical Modulation of Wintertime Synoptic-Scale Cyclone Activity over the Japan Sea due to Changbai Mountain in the Korean Peninsula

The dynamical impact of the Changbai Mountain Range in the Korean Peninsula on the extratropical cyclone activity over the Japan Sea in early winter is examined using the Weather Research Forecasting model. We have conducted two independent long-term integrations over 15 winter months (December only) from 2000 to 2014 with and without modified topography. The results show that the Changbai Mountain Range plays a vital role in increasing cyclone track frequency, low-level poleward eddy heat flux, and the local deepening rate over the Japan Sea through enhancement of the lower-tropospheric baroclinic zone (LTBZ). This mountain range gives rise to activation of the synoptic-scale cyclone activity over that region. From our case study on three typical cyclones, it is found that mesoscale structures in the vicinity of a cyclone’s center are dynamically modulated when it passes through the LTBZ and that cyclogenesis is triggered around that zone. A vorticity budget analysis shows that the stretching term relevant to enhanced low-level convergence plays a dominant role in intensifying cyclonic vorticities. We confirmed that the composite features of the three typical cases are consistent with the statistical ones of the dynamical modulation of the Changbai Mountain on synoptic-scale cyclone activity

Electron Beam Lithography for Large Area Patterning 3: Data Conversion and Electron Beam Deflection Control

Electron beam direct writing technologies, specifically for the large area patterning of electronic devices such as printed wiring boards, are studied in this paper. The vector scanning method with two kinds of beam deflection, main-deflection and sub-deflection, has been adopted for the fabrication of circuit patterns of various line widths. The sub-deflection of high frequency oscillation is superimposed on the main-deflection, which allows for controlling each line width with ease. A data conversion and a deflection control system with several strategies have been developed to reduce the conversion time and the volume of output data. It is revealed that circuit patterns of widths from 70 μm to 250 μm can be fabricated effectively with these new technologies

Electron Beam Lithography for Large Area Patterning 1: Development of Large Field Deflection E-Beam Lithography System

A novel electron beam system has been designed and developed specifically for large area patterning of electronic devices such as printed wiring boards. The prototyped system features a large field deflection, high scanning speed and stably focused beam in the large field. An electron gun with a LaB5 flat cathode was used by operating at 1750-1800 K. The electron beam column provides an electron probe of less than 40 μm in diameter with a current of 50 μA at 60 kV. Fast and large field deflections by a magnetic deflection system enables an area of 104 mm x 104 mm to be covered. The scanning speed can range up to 254 m/s. Particular attention was paid to the materials and shapes of the optics column to minimize the influence of eddy currents from the point of view of controlling the dynamic behavior of beam deflection. It is confirmed that the system can provide accurate beam deflection within a ±20 μm (3) tolerance for the quite large field of 52 mm x 52 mm

Electron Beam Lithography for Large Area Patterning 2: Exposure Characteristics of Electrodeposited Thick Resist

Exposure characteristics of a large field deflection electron beam lithography system have been examined. Thick film mainly composed of unsaturated acrylic resins and prepared by electrodeposition process is proposed as a resist available to large area patterning. It is proved that the 20 μm thick resist is very sensitive to 60 kV electron beam and has the threshold dosage of 2.0 x 10-7 C/cm2. The spatial contours of equienergy density deposited by electron beam in a 20 μm thick resist on a semi-infinite thick copper substrate are calculated by Monte Carlo simulation for a line source with a lateral beam profile described by Gaussian distribution. The comparison of Monte Carlo calculations with the experiment has led to conclusions that the line width of the electrodeposited resist is determined by the contour line corresponding to about 1.5 x 1019 eV/ cm3 and that line widths less than 100 μm can be obtained with high stability within a fluctuation of less than ±10% for the large scanning field of 52 mm x 52 mm

A Comparison of Physical vs. Nonphysical Wedge Modalities in Radiotherapy

This chapter discusses the clinical application and implementation of wedge techniques in radiation therapy. Coverage of the target region with a curative dose is critical for treating several cancer types; to that end, wedge filters are commonly used to improve dose uniformity to the target volume. Initially, wedges designed for this purpose were physical and were made of high-density materials such as lead or steel. Subsequently, nonphysical wedges were introduced; these improved the dose uniformity using computer systems in lieu of physical materials. As wedge systems evolve, however, they each continue to have their advantages and disadvantages. When using physical wedges, it is difficult to control the generation of secondary radiation resulting from the collision of the radiation beam with the wedge body; conversely, nonphysical wedges do not create any secondary radiation because there is no physical interference with the beam. On the other hand, nonphysical wedges are less suitable for treating moving tumors, such as those in the lung, and physical wedges have better dose coverage to the target volume than nonphysical wedges. This chapter aims to guide decision-making regarding the choice of wedge types in various clinical situations

Host range and receptor utilization of canine distemper virus analyzed by recombinant viruses: Involvement of heparin-like molecule in CDV infection

AbstractWe constructed recombinant viruses expressing enhanced green fluorescent protein (EGFP) or firefly luciferase from cDNA clones of the canine distemper virus (CDV) (a Japanese field isolate, Yanaka strain). Using these viruses, we examined susceptibilities of different cell lines to CDV infection. The results revealed that the recombinant CDVs can infect a broad range of cell lines. Infectivity inhibition assay using a monoclonal antibody specific to the human SLAM molecule indicated that the infection of B95a cells with these recombinant CDVs is mainly mediated by SLAM but the infection of 293 cell lines with CDV is not, implying the presence of one or more alternative receptors for CDV in non-lymphoid tissue. Infection of 293 cells with the recombinant CDV was inhibited by soluble heparin, and the recombinant virus bound to immobilized heparin. Both F and H proteins of CDV could bind to immobilized heparin. These results suggest that heparin-like molecules are involved in CDV infection

Inhibitory Effect of a Tankyrase Inhibitor on Mechanical Stress-Induced Protease Expression in Human Articular Chondrocytes

We investigated the effects of a Tankyrase (TNKS-1/2) inhibitor on mechanical stress-induced gene expression in human chondrocytes and examined TNKS-1/2 expression in human osteoarthritis (OA) cartilage. Cells were seeded onto stretch chambers and incubated with or without a TNKS-1/2 inhibitor (XAV939) for 12 h. Uni-axial cyclic tensile strain (CTS) (0.5 Hz, 8% elongation, 30 min) was applied and the gene expression of type II collagen a1 chain (COL2A1), aggrecan (ACAN), SRY-box9 (SOX9), TNKS-1/2, a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5), and matrix metalloproteinase-13 (MMP-13) were examined by real-time PCR. The expression of ADAMTS-5, MMP-13, nuclear translocation of nuclear factor-κB (NF-κB), and β-catenin were examined by immunocytochemistry and Western blotting. The concentration of IL-1β in the supernatant was examined by enzyme-linked immunosorbent assay (ELISA). TNKS-1/2 expression was assessed by immunohistochemistry in human OA cartilage obtained at the total knee arthroplasty. TNKS-1/2 expression was increased after CTS. The expression of anabolic factors were decreased by CTS, however, these declines were abrogated by XAV939. XAV939 suppressed the CTS-induced expression of catabolic factors, the release of IL-1β, as well as the nuclear translocation of NF-κB and β-catenin. TNKS-1/2 expression increased in mild and moderate OA cartilage. Our results demonstrated that XAV939 suppressed mechanical stress-induced expression of catabolic proteases by the inhibition of NF-κB and activation of β-catenin, indicating that TNKS-1/2 expression might be associated with OA pathogenesis

Surgical Results in T2N0M0 Nonsmall Cell Lung Cancer Patients With Large Tumors 5 cm or Greater in Diameter: What Regulates Outcome?

金沢大学医学部附属病院呼吸器外科Background: We assessed the surgical results along with the clinical and biological features of nonsmall-cell lung cancer (NSCLC) patients with localized large tumors. Methods: The study population consisted of 86 NSCLC patients who underwent complete resection of tumors 5 cm or larger in diameter in stage IB (T2N0M0). We immunohistochemically assessed the expression of angiostatin and endostatin. Results: The median tumor size was 6.0 cm (range, 5 to 14 cm). The operative procedures used were lobectomy in 71 cases, bilobectomy in 8 cases, and pneumonectomy in 11 cases. Fifty patients (58.1%) relapsed during the mean follow-up period of 33.6 ± 4.5 months. The median disease-free interval was 9 months. Of 44 recurrent patients whose disease-free interval could be identified, 25 patients (56.8%) relapsed within 12 months after the operation. The overall 5- and 10-year survival rates were 42.0% and 24.2%, respectively. Multivariate analysis showed that the degree of pleural involvement and angiostatin expression within the tumor were independent prognostic indicators. The endostatin expression within tumors also had a weaker relationship with outcome. Conclusions: Long-term surgical results were poor and early relapse was common in this cohort. In addition to pleural involvement, the tumor-induced expression of angiostatin and endostatin merit further investigation to gain possible insights into selection of patients who will benefit from surgery as the first line treatment. © 2006 The Society of Thoracic Surgeons