Development of ion beam figuring system with electrostatic deflection for ultraprecise X-ray reflective optics

We developed an ion beam figuring system that utilizes electrostatic deflection. The system can produce an arbitrary shape by deterministically scanning the ion beam. The scan of the ion beam, which can be precisely controlled using only an electrical signal, enables us to avoid degradation of the mirror shape caused by imperfect acceleration or deceleration of a mechanically scanning stage. Additionally, this surface figuring method can easily be combined with X-ray metrology because the workpiece remains fixed during the figuring. We evaluated the figuring accuracy of the system by fabricating a plano-elliptical mirror for X-ray focusing. A mirror with a shape error of 1.4 nm root mean square (RMS) with a maximum removal depth of 992 nm, which corresponds to figuring accuracy of 0.14% RMS, was achieved. After the second shape corrections, an elliptical shape with a shape error of approximately 1 nm peak-to-valley, 0.48 nm RMS could be fabricated. Then, the mirror surface was smoothed by a low-energy ion beam. Consequently, a micro-roughness of 0.117 nm RMS, measured by atomic force microscopy, was achieved over an area of 1 × 1 μm2.Jumpei Yamada, Satoshi Matsuyama, Yasuhisa Sano, and Kazuto Yamauchi, "Development of ion beam figuring system with electrostatic deflection for ultraprecise X-ray reflective optics", Review of Scientific Instruments 86, 093103 (2015) https://doi.org/10.1063/1.4929323

Indistinguibilidad de la cinemática de la raqueta y del cuerpo en diferentes servicios de tenis de mesa en jugadores internaciones de élite e intermedios

Table tennis serves are strokes in which disguise and deception skills are important. This study aimed to investigate whether international elite table tennis players can make their racket and body kinematics more indistinguishable than intermediate players during three different serve types. Five former international elite and 8 intermediate players performed 3–12 trials of each serve type. The kinematics of the server’s body and the racket was determined using a motion capture system. The time instant of racket-ball impact was determined using a high-speed video camera with the motion capture system. Misclassification rates when the serve type was classified using the racket and body kinematics were determined using linear discriminant analysis. Elite players showed higher misclassification rates for the racket kinematics than intermediate players during the early swing and follow-through phases. The body kinematics suggested that the elite players made their racket kinematics more indistinguishable using different approaches between the early swing and follow-through phases. The elite players tended to make the racket’s angular velocity more similar and make the wrist rotational variables more indistinguishable in different serves compared to the intermediate players during the early swing phase. In contrast, the elite players made the racket’s linear motion more variable within individual serve types than the intermediate players during the follow-through. The results suggest that intermediate players are recommended to practice making wrist angular motions more similar during the early swing phase and making racket linear motions more variable during the follow-through in order to improve the disguise skill in table tennis serves.Los servicios en el tenis de mesa son movimientos en los que las habilidades para enmascarar y engañar son importantes. El objetivo de este estudio fue investigar si los jugadores de tenis de mesa de élite internacionales pueden hacer que la cinemática de su raqueta y cuerpo sea más indistinguible que los jugadores intermedios durante tres tipos de servicio diferentes. Cinco exjugadores internacionales de élite y 8 jugadores intermedios realizaron de 3 a 12 intentos de cada tipo de servicio. La cinemática del cuerpo y de la raqueta del servidor fue determinada a través de un sistema de captura del movimiento. El momento del impacto raqueta-pelota fue determinado usando una videocámara de alta velocidad con sistema de captura de movimiento. Las tasas de clasificación errónea cuando el tipo de servicio fue clasificado usando la cinemática de la raqueta y del cuerpo fueron determinadas por medio de un análisis discriminante linear. Los jugadores de élite mostraron tasas de clasificación errónea más altas en la cinemática de la raqueta que los jugadores intermedios durante la fase inicial del swing y la fase de terminación. La cinemática del cuerpo sugirió que los jugadores de élite hicieron su cinemática de la raqueta más indistinguible al usar diferentes enfoques entre la fase inicial del swing y la de terminación. Los jugadores de élite tuvieron una tendencia a hacer que la velocidad angular de la raqueta fuera más similar y las variables de rotación de la muñeca fueran más indistinguibles en diferentes servicios comparados con los jugadores intermedios durante la fase inicial del swing. En contraste, los jugadores de élite hicieron que el movimiento lineal de la raqueta fuera más variable en tipos de servicio individual que los jugadores intermedios durante la terminación. Los resultados sugieren que los jugadores intermedios deberían hacer movimientos angulares de muñeca más similares durante la fase inicial del swing y hacer que los movimientos lineares de la raqueta sean más variables durante la terminación para mejorar la habilidad para enmascarar los servicios de tenis de mesa

DEVELOPMENT OF A TABLE TENNIS MACHINE TO COUNTER THE “CHIQUITA” SPIN

After Beijing Olympics, leading athletes began to use a stroke known as the “Chiquita” spin frequently. Thus, the Japan national table tennis team at the time undertook countermeasures against the Chiquita spin including some plans. However, these did not produce significant results. Therefore, we developed a table tennis training machine for the team in activities supporting the Japan national table tennis team. The machine has 3 rotors to shoot a ball stably. Also, these rotors are twisted to make a “gyro rotation” of the ball. This machine was introduced into the Japan national table tennis team to take measures for London 2012 Olympic

β-Hemolytic Streptococcus anginosus subsp. anginosus causes streptolysin S-dependent cytotoxicity to human cell culture lines in vitro

Background: Streptococcus anginosus subsp. anginosus (SAA) is one of the opportunistic pathogens in humans that inhabits the oral cavity. The type strain of SAA, NCTC10713T, showed clear β-hemolysis on blood agar plates, and the sole β-hemolytic factor revealed two streptolysin S (SLS) molecules. SLS is well known as the peptide hemolysin produced from the human pathogen S. pyogenes and shows not only hemolytic activity on erythrocytes but also cytotoxic activity in cell culture lines in vitro and in vivo, such as in a mouse infection model. However, no cytotoxic activity of SLS produced from β-hemolytic SAA (β-SAA) has been reported so far. Objective and Design: In this study, the SLS-dependent cytotoxicity of the β-SAA strains including the genetically modified strains was investigated in vitro. Results: The SLS-producing β-SAA showed cytotoxicity in human cell culture lines under the co-cultivation condition and it was found that this cytotoxicity was caused by the SLS secreted into the extracellular milieu. Conclusion: The results from this study suggest that the SLS produced from β-SAA might indicate the cytotoxic potential similar to that of the SLS from S. pyogenes and the SLS-producing β-SAA would be recognized as “a wolf in sheep’s clothing” More attention will be paid to the pathogenicity of β-hemolytic Anginosus group streptococci

Tumefactive multiple sclerosis requiring emergent biopsy and histological investigation to confirm the diagnosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Tumefactive multiple sclerosis is a demyelinating disease that demonstrates tumor-like features on magnetic resonance imaging. Although diagnostic challenges without biopsy have been tried by employing radiological studies and cerebrospinal fluid examinations, histological investigation is still necessary for certain diagnosis in some complicated cases.</p> <p>Case presentation</p> <p>A 37-year-old Asian man complaining of mild left leg motor weakness visited our clinic. Magnetic resonance imaging demonstrated high-signal lesions in bilateral occipital forceps majors, the left caudate head, and the left semicentral ovale on fluid-attenuated inversion recovery and T2-weighted imaging, and these lesions were enhanced by gadolinium-dimeglumin. Tumefactive multiple sclerosis was suspected because the enhancement indistinctly extended along the corpus callosum on magnetic resonance imaging and scintigraphy showed a low malignancy of the lesions. But oligoclonal bands were not detected in cerebrospinal fluid. In a few days, his symptoms fulminantly deteriorated with mental confusion and left hemiparesis, and steroid pulse therapy was performed. In spite of the treatment, follow-up magnetic resonance imaging showed enlargement of the lesions. Therefore, emergent biopsy was performed and finally led to the diagnosis of demyelinating disease. The enhanced lesion on magnetic resonance imaging disappeared after one month of prednisolone treatment, but mild disorientation and left hemiparesis remained as sequelae.</p> <p>Conclusions</p> <p>Fulminant aggravation of the disease can cause irreversible neurological deficits. Thus, an early decision to perform a biopsy is necessary for exact diagnosis and appropriate treatment if radiological studies and cerebrospinal fluid examinations cannot rule out the possibility of brain tumors.</p

X-Ray Single-Grating Interferometry for Wavefront Measurement and Correction of Hard X-Ray Nanofocusing Mirrors

X-ray single-grating interferometry was applied to conduct accurate wavefront corrections for hard X-ray nanofocusing mirrors. Systematic errors in the interferometer, originating from a grating, a detector, and alignment errors of the components, were carefully examined. Based on the measured wavefront errors, the mirror shapes were directly corrected using a differential deposition technique. The corrected X-ray focusing mirrors with a numerical aperture of 0.01 attained two-dimensionally diffraction-limited performance. The results of the correction indicate that the uncertainty of the wavefront measurement was less than λ/72 in root-mean-square value.Yamada, J.; Inoue, T.; Nakamura, N.; Kameshima, T.; Yamauchi, K.; Matsuyama, S.; Yabashi, M. X-Ray Single-Grating Interferometry for Wavefront Measurement and Correction of Hard X-Ray Nanofocusing Mirrors. Sensors 2020, 20, 7356. https://doi.org/10.3390/s20247356

Development of concave-convex imaging mirror system for a compact and achromatic full-field x-ray microscope

Jumpei Yamada, Satoshi Matsuyama, Shuhei Yasuda, Yasuhisa Sano, Yoshiki Kohmura, Makina Yabashi, Tetsuya Ishikawa, and Kazuto Yamauchi "Development of concave-convex imaging mirror system for a compact and achromatic full-field x-ray microscope", Proc. SPIE 10386, Advances in X-Ray/EUV Optics and Components XII, 103860C (6 September 2017); https://doi.org/10.1117/12.2272904

Essential roles of DC-derived IL-15 as a mediator of inflammatory responses in vivo

Interleukin (IL)-15 is expressed in a variety of inflammatory diseases. However, the contribution of dendritic cell (DC)–derived IL-15 to the development of diseases is uncertain. Using established models of Propionibacterium acnes (P. acnes)– and zymosan-induced liver inflammation, we observed granuloma formation in the livers of wild-type (WT) and RAG-2−/− mice but not in those of IL-15−/− mice. We demonstrate that this is likely caused by an impaired sequential induction of IL-12, IFN-γ, and chemokines necessary for monocyte migration. Likewise, lethal endotoxin shock was not induced in P. acnes– and zymosan-primed IL-15−/− mice or in WT mice treated with a new IL-15–neutralizing antibody. In both systems, proinflammatory cytokine production was impaired. Surprisingly, neither granuloma formation, lethal endotoxin shock, nor IL-15 production was induced in mice deficient for DCs, and adoptive transfer of WT but not IL-15−/− DCs restored the disease development in IL-15−/− mice. Collectively, these data indicate the importance of DC-derived IL-15 as a mediator of inflammatory responses in vivo

Hard x-ray intensity autocorrelation using direct two-photon absorption

An intensity autocorrelation measurement is demonstrated to characterize a pulse duration of 9-keV x-ray free-electron laser (XFEL) pulses from a split-delay optical (SDO) system with four-bounce silicon 220 reflections in each branch. XFEL pulse replicas with variable time delays are generated by the SDO system itself. High intensity of >2×1016W/cm2 achieved in a self-seeding operation and careful data analysis allow the measurement with direct two-photon absorption. The autocorrelation trace gave a duration of 7.6±0.8fs in full width at half maximum for a Gaussian assumption. Furthermore, the trace shows good agreement with a simulation of the XFEL pulse shape propagating through the SDO system, irrespective of spectral chirps in the original XFEL pulses. Our results open the door toward direct temporal characterization of narrowband XFELs at the hard x-ray regime, such as self-seeded and future cavity-based XFELs, and indicate a solid way for temporal tailoring of ultrafast x-ray pulses with perfect crystals.Osaka T., Inoue I., Yamada J., et al. Hard x-ray intensity autocorrelation using direct two-photon absorption. Physical Review Research, 4, 1, L012035. https://doi.org/10.1103/PhysRevResearch.4.L012035