12 research outputs found
Fibrous Calcareous Concretions in the Capsules of Human Pineal Glands
We examined calcareous concretions in the capsule of 15 human pineal glands containing a large amount of the concretions in the matrix. The capsule concretions, brown to blackish-brown in color and/or translucent, were smaller than the matrix concretions, which were yellowish-white. The matrix concretions showed the typical mulberry-shaped overall appearance with scallop-shaped concentric laminations of non-fibrous structures, but the capsule concretions, which also contained Ca and P, showed a globular or oval shape with regular, rough, or no concentric laminations. The capsule concretions also showed globules of mineralized collagen fibers that resembled randomly wound threads and that were occasionally associated with minute spherical deposits showing hypermineralization in the core region as initial calcification. Na was detected as a minor characteristic element of the capsule concretions, and at a significantly higher level than that of the matrix concretions. The findings strongly suggested that a human pineal gland containing numerous matrix concretions is likely to produce mineralized deposits in the capsule
Mineralized Blood Vessels in the Capsules of Human Pineal Glands
We observed mineralized blood vessels in the capsules of human pineal glands containing abundant fibrous calcareous concretions in the capsules as well as non-fibrous calcareous concretions (brain sands) in the gland matrix. The capsular blood vessels were sometimes scattered with mineralized, round deposits of various sizes containing minute spherical deposits (MSD). The MSD showed hypermineralization similar to that in capsular fibrous concretions reported in our recent study and some MSD resembled those consistent with Fahr\u27s disease. Occasionally, the vessel lumens were completely embedded with mineralized deposits. As the characteristic means of detection from the mineralized blood vessels, the volume of Na was significantly higher than that of the matrix non-fibrous concretions. The origin of Na in the mineralized blood vessels containing MSD was likely derived from the connective tissue fluid. Our findings suggested that a human pineal gland matrix containing numerous non-fibrous concretions is likely to associate with mineralized deposits within the blood vessels as well as fibrous concretions in the capsule
Mechanical Strength of the Mayo Clinic Congruent Elbow Plate System for Distal Humerus Fractures: Cadaveric and Model Bone Model
The purpose of this study was to compare the Mayo Clinic Congruent Elbow Plate System with a plate system having the same biomechanical features as a conventional non-locking system. For testing, we used a biaxial adjustable material testing machine (Mini-Bionix®, MTS, Minnetonka, MN). A compressive load of 500 N/min was applied in the axial direction, and a torque of 30 deg/min was applied in the rotational direction to simulate internal rotation of the elbow. The relationships between force (N) and displacement (mm), and between the internal rotational angle (deg) and torque (N/m), were measured. The Mayo Clinic Congruent Elbow Plate and the two types of screws used in this study may provide sufficient fixation strength. The results obtained here warrant further studies that are more dynamic (e.g., cyclic loading and repetitive torsion tests), with a larger number of specimens, and that facilitate appropriate nomal elbow movement in daily living, to assess the utility of plate fixation with locking and non-locking systems for distal humerus fractures
Effectiveness of Initial Fixation of a Grasping Pin for Proximal Femoral Fractures
We developed a grasping pin with a hook for osteosynthesis of proximal femoral fractures and compared its performance with that of a lag screw. Cyclic compressive tests were performed to simulate cut-outs, and quasi-static torsion, tests were conducted to simulate rotational displacement in polyurethane model bones and femoral heads collected after hip replacement surgery, and cadaveric femoral heads. In the polyurethane model bones and femoral head collected after hip replacement surgery, implant displacement was increased in the cut-out simulation test in both the grasping pin group and lag screw group, deformation was less in the grasping pin group than in the lag screw group. In polyurethane bones and cadaveric bones, the grasping pins showed higher rotational resistance compared with the lag screws in the quasi-static torsion test because of the high compression force generated during implantation. In contrast, in the collected femoral head after hip replacement surgery model, the lag screws destroyed bone tissue, the lag screw group exhibited a higher rotational resistance and a lower risk of rotational displacement than the grasping pin model. The depth of cadaveric femoral heads was 60mm compared with 30mm for femoral heads obtained after surgery; therefore, the pins could be completely inserted up to the octagonal portion in the cadaveric bones, resulting in higher rotational resistance
セキドウ タイキ レーダー ヲ モチイタ コウド 150 km エンジリョクセン フキソク コウゾウ ノ ドリフト ソクド ニ カンスル ケンキュウ
高度130-170 kmの電離圏において昼間に発生する「高度150 km沿磁力線不規則構造(FAI)エコー」は,赤道域に設置されたVHFレーダーによって1960年代以降,観測されてきた.本研究では,2007年8月から2009年10月までに,インドネシアの赤道大気レーダー(EAR)によって昼間に観測された150 km FAIエコーのドリフト速度の統計解析を行った。このデータと経験モデルから得られたF 領域プラズマ・ドリフト速度及び,ヒカマルカIS レーダーによる観測結果との比較を行った.その結果,150 km FAI エコーの磁力線直交上/ 南向きドリフト速度は,午後において減少することが明らかになった.この傾向は,F 領域プラズマ・ドリフト速度の場合と一致する.一方,150 km FAI エコーの西向きドリフト速度は,昼間において時間とともに減少する傾向があり,ヒカマルカの非干渉散乱レーダーで観測されたF 領域プラズマ・ドリフト速度が示すような正午付近の極大は顕著ではなかった.150 km FAI ドリフト速度の大きさは,F 領域プラズマ・ドリフト速度と比較し,平均で鉛直成分は約3 m/s 小さく,東西成分は25 m/s 小さいことが明らかになった.この違いを,電場生成領域であるE 領域の,磁気緯度による違いで説明するのは難しく,高度150 km 付近で生成される局所的な電場が影響している可能性が考えられる.Between 130 and 170 km altitude in the daytime ionosphere, the so-called 150-km field-aligned irregularities (FAIs) have been observed since the 1960s at equatorial regions with several very high frequency (VHF) radars. We report statistical results of 150-km FAI drift velocities on a plane perpendicular to the geomagnetic field, acquired by analyzing the Doppler velocities of 150-km FAIs observed with the Equatorial Atmosphere Radar (EAR) at Kototabang, Indonesia during the period from Aug. 2007 to Oct. 2009. We found that the southward/upward perpendicular drift velocity of the 150-km FAIs tends to decrease in the afternoon and that this feature is consistent with that of F-region plasma drift velocities over the magnetic equator. The zonal component of the 150-km FAI drift velocity is westward and decreases with time, whereas the F-region plasma drift velocity observed with the incoherent scatter radar at Jicamarca, Peru, which is westward, reaches a maximum at about noon. The southward/upward and zonal drift velocities of the 150-km FAIs are smaller than that of the F-region plasma drift velocity by approximately 3 m/s and 25 m/s, respectively, on average. The large difference between the 150-km FAI and F-region plasma drift velocities may not arise from a difference in the magnetic latitudes at which their electric fields are generated. Electric fields generated at the altitude at which the 150-km FAIs occur may not be negligible
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Drift velocities of 150-km Field-Aligned Irregularities observed by the Equatorial Atmosphere Radar
Between 130 and 170 km altitude in the daytime ionosphere, the so-called 150-km field-aligned irregularities (FAIs) have been observed since the 1960s at equatorial regions with several very high frequency (VHF) radars. We report statistical results of 150-km FAI drift velocities on a plane perpendicular to the geomagnetic field, acquired by analyzing the Doppler velocities of 150-km FAIs observed with the Equatorial Atmosphere Radar (EAR) at Kototabang, Indonesia during the period from Aug. 2007 to Oct. 2009. We found that the southward/upward perpendicular drift velocity of the 150-km FAIs tends to decrease in the afternoon and that this feature is consistent with that of F-region plasma drift velocities over the magnetic equator. The zonal component of the 150-km FAI drift velocity is westward and decreases with time, whereas the F-region plasma drift velocity observed with the incoherent scatter radar at Jicamarca, Peru, which is westward, reaches a maximum at about noon. The southward/upward and zonal drift velocities of the 150-km FAIs are smaller than that of the F-region plasma drift velocity by approximately 3 m/s and 25 m/s, respectively, on average. The large difference between the 150-km FAI and F-region plasma drift velocities may not arise from a difference in the magnetic latitudes at which their electric fields are generated. Electric fields generated at the altitude at which the 150-km FAIs occur may not be negligible