313 research outputs found

    Protective effect of Sanguisorbae Radix against peroxynitrite-mediated renal injury

    Get PDF
    3-Nitrotyrosine, an oxidative product of protein that is produced via peroxynitrite (ONOO^-) nitration, was detected by HPLC analysis in plasma obtained from rats injected with lipopolysaccharide (LPS) and subjected to renal ischemia followed by reperfusion (LPS+ischemia-reperfusion), but not in rats subjected to sham-treatment. Rats pretreated with Sanguisorbae Radix extract orally for 30 days before LPS+ischemia-reperfusion, had lower 3-nitrotyrosine levels than rats without the pretreatment. Plasma levels of urea nitrogen and creatinine, indicators of renal dysfunction, were markedly lower in the animals pretreated with Sanguisorbae Radix extract than in those without the pretreatment. In addition, DNA fragmentation in renal tissues was significantly inhibited by administration of Sanguisorbae Radix prior to LPS+ischemia-reperfusion. These results suggest that Sanguisorbae Radix extract ameliorates oxidative damage caused by ONOO^-. パーオキシナイトライトは蛋白中のチロシンをニトロ化して3-ニトロチロシンを生成するが,この3-ニトロチロシンをHPLCで測定した結果,リポポリサッカライドと虚血-再灌流を施したラット血漿で検出され,偽処理した場合には検出されなかった。一方,リポポリサッカライドと虚血-再灌流を施す前に30日間地楡エキスを経口投与したラットでは,非投与群より低い3-ニトロチロシン値を示し,腎機能の指標の血漿尿素窒素,クレアチニンレベルも著しく低下していた。また腎組織中のDNA断片化も抑制され,地楡エキスがパーオキシナイトライトによる酸化的損傷を軽減することが推測された

    Physical properties of a new cuprate superconductor Pr_2Ba_4Cu_7O_{15-\delta}

    Full text link
    We present studies of the thermal, magnetic and electrical transport properties of reduced polycrystalline Pr_2Ba_4Cu_7O_{15-\delta} (Pr247) showing a superconducting transition at Tc = 10 - 16 K and compare them with those of as-sintered non-superconducting Pr247. The electrical resistivity in the normal state exhibited T2 dependence up to approximately 150 K. A clear specific heat anomaly was observed at Tc for Pr247 reduced in a vacuum for 24 hrs, proving the bulk nature of the superconducting state. By the reduction treatment, the magnetic ordering temperature TN of Pr moments decreased from 16 to 11 K, and the entropy associated with the ordering increased, while the effective paramagnetic moments obtained from the DC magnetic susceptibility varied from 2.72 to 3.13 mB. The sign of Hall coefficient changed from positive to negative with decreasing temperature in the normal state of a superconducting Pr247, while that of as-sintered one was positive down to 5 K. The electrical resistivity under high magnetic fields was found to exhibit T^a dependence (a = 0.08 - 0.4) at low temperatures. A possibility of superconductivity in the so-called CuO double chains is discussed.Comment: Science and Technology of Advanced Materials (in press

    野球の打撃における上肢のエネルギーフロー : バット・ヘッドスピードの上位群と下位群のスイング局面の比較

    Get PDF
    This study examined the flow of energy in the right and left upper limbs of skilled baseball batters during the forward swing motion at different bat head speeds to obtain basic insights that would be useful for batting coaching. The subjects were 23 college baseball outfielders in university teams. The subjects were instructed to hit a ball toward the pitcher from a tee set at a mid-height position. Measurements were taken using 47 points on each subject’s body and 6 points on the bat for a total of 53 points, onto which reflective markers were attached. The 3D coordinates of each marker were measured using a 3D optical motion capture device (Vicon Motion Systems’ VICONMX, 12 cameras, 250 Hz). The variables in the kinetics of each hand were measured using a force detection sensor bat (1000 Hz). The subjects were separated into a faster group of 36.8±0.8 m/s and a slower group of 34.7±1.1 m/s for analysis. In terms of energy transmission, the data revealed that the faster group, in addition to showing additional torque on the knob side shoulder joints, were able to transmit more mechanical energy from the knob side shoulder joints to the end of the upper limbs than the slower group, and that this might be related to an efficient bat head speed. In addition, the faster group showed an increased positive torque power, and transmitted greater mechanical energy to the bat from the hand region. In other words, to prevent mechanical energy from being absorbed while adjusting the bat trajectory near the time of impact, skilled bat control involving movement of the hand joints appeared to determine the bat head speed

    野球打撃における身体の回転運動に対する下肢のキネマティクスについて : 地面反力によるモーメントの上位群と下位群の比較

    Get PDF
    The purpose of this study was to investigate the kinematic characteristics of the lower limbs in relation to the rotation movement of the body based on the moment of the ground reaction force. Twenty-two male collegiate baseball players (age: 19.8 ± 1.3 yr, height 1.75 ± 0.04 m, body mass 73.9 ± 6.2 kg, athletic career:12.1 ± 2.1 yr) participated. They performed baseball tee-batting, set at middle ball height for the strike zone. Threedimensional coordinate data were acquired with a motion capture system (Vicon-MX), and ground reaction force data for both legs were acquired with 3 force platforms. High and low groups (HG and LG) were categorized by the mean peak moment around the vertical axis of the body’s center of gravity caused by the ground reaction force. The period analyzed was that from stride-side foot contact with ground until ball impact, and 2 phases were defined as follows: backward phase, stride-side foot contact with ground until the peak moment of the ground reaction force; forward phase, the end of the backward phase until ball impact. Statistical analysis was conducted using an independent t-test between HG and LG (p <0.05), and the effect size was calculated (small: d = 0.2; middle: d = 0.5; high: d = 0.8). In the backward phase, the flexion angle of both hips was greater in the HG than in the LG at event1 (pivot-side: d = 0.74; stride-side: d =0.97). The abduction angle of the pivot-side hip was significantly greater in the HG than in the LG (stride-side foot contact with ground: d = 0.94; peak moment of the ground reaction force: d = 1.44). In the forward phase, the external rotation angle of the pivot-side hip was significantly greater in the HG than in the LG (d = 1.02), which contributed to the inter-group difference in the internal rotation angle at the instant of stride-side foot contact. These results indicate that the motions of both hip joints acted to rotate the whole body around the vertical axis effectively. The knowledge obtained from this study should provide useful suggestions and insights into coaching for movements of the lower limbs in order to improve batting performance in relation to the rotational movement of the body

    Shortwave radiative forcing, rapid adjustment, and feedback to the surface by sulfate geoengineering: analysis of the Geoengineering Model Intercomparison Project G4 scenario

    Get PDF
    This study evaluates the forcing, rapid adjustment, and feedback of net shortwave radiation at the surface in the G4 experiment of the Geoengineering Model Intercomparison Project by analysing outputs from six participating models. G4 involves injection of 5 Tg yr(-1) of SO2, a sulfate aerosol precursor, into the lower stratosphere from year 2020 to 2069 against a background scenario of RCP4.5. A single-layer atmospheric model for shortwave radiative transfer is used to estimate the direct forcing of solar radiation management (SRM), and rapid adjustment and feedbacks from changes in the water vapour amount, cloud amount, and surface albedo (compared with RCP4.5). The analysis shows that the globally and temporally averaged SRM forcing ranges from -3.6 to -1.6 W m(-2), depending on the model. The sum of the rapid adjustments and feedback effects due to changes in the water vapour and cloud amounts increase the downwelling shortwave radiation at the surface by approximately 0.4 to 1.5 W m(-2) and hence weaken the effect of SRM by around 50 %. The surface albedo changes decrease the net shortwave radiation at the surface; it is locally strong (∼ −4 W m(-2)) in snow and sea ice melting regions, but minor for the global average. The analyses show that the results of the G4 experiment, which simulates sulfate geoengineering, include large inter-model variability both in the direct SRM forcing and the shortwave rapid adjustment from change in the cloud amount, and imply a high uncertainty in modelled processes of sulfate aerosols and clouds
    corecore