Various characteristics of piezo-remanent magnetization of igneous rocks are experimentally demonstrated in small magnetic fields, H=0-10Oe., and under uniaxial compression comparable to the earth's crust stress, 0-100kg/cm². The main characteristics observed are as follows:
(a) “After-effect” of uniaxial compression: (P₊P₀H₊H₀).
After a rock sample is uniaxially compressed in a non-magnetic space by a pressure P larger than a certain critical value (P_c), its IRM, (P₊P₀H₊H₀), becomes larger than the ordinary IRM, (H₊H₀), without such a pressure treatment. This after-effect of pressure takes place in both cases of P//H and P⊥H.
Here [d/dPJ_R(P₊P₀H₊H₀)]_H=const>0 for P>P_c.
(b) “Pressure demagnetization” effect: (H₊H₀P₊P₀).
After uniaxially compressing a rock sample having IRM, (H₊H₀), in a non-magnetic space, the residual magnetization, (H₊H₀P₊P₀), becomes appreciably smaller than the original intensity of (H₊H₀) in both cases of P//H and P⊥H.
Here [d/dPJ_R(H₊H₀P₊P₀)]_H=const<0, and [d²/(H₊H₀P₊P₀)]_H=const>0.
(c) “Non-commutativity” of P and H.
An inequality relationship expressed as
(H₊P₊P₀H₀)≥(P₊H₊P₀H₀)>(H₊P₊H₀P₀)≥(P₊H₊H₀P₀)
holds for all samples. In a magnetic field larger than a certain critical value, H*,
(P₊H₊H₀P₀)<(H₊H₀), but in H<H* (P₊H₊H₀P₀)>(H₊H₀).
(H₊P₊P₀H₀) and (P₊H₊P₀H₀) are always larger than (H+H₀). The above argument holds in both cases of P//H and P⊥H.
(d) A linear dependence of PRM on H.
(H₊P₊P₀H₀) is defined as piezo-remanent magnetization. In a range of small magnetic fields,
(H₊P₊P₀H₀)∞H for P=constant, though (H₊H₀)∞H² in the

抄録全体を表示

The aim of this study was to elucidate the electrophysiologic characteristics and clinical significance of the accelerated junctional rhythm () that remains after termination of radiofrequency (RF) current delivery during catheter ablation (CA) for atrioventricular nodal reentrant tachycardia (AVNRT). Fifty consecutive patients with AVNRT (21M, 29F, age 48 years) underwent RF-CA targeting the slow pathway. occurred at 124 out of a total of 236 ablation sites (53%) during the RF delivery. With 15 RF deliveries (6.4%, n=10), remained after termination of the RF delivery (Post-). The mean cycle length of the Post- immediately after termination of the RF delivery was 639±124 ms and its duration was widely distributed from 3 s to more than 1 h. The Post- exhibited a spontaneous rate deceleration and overdrive suppression by rapid atrial pacing. The during the RF delivery followed by Post- had a greater time span in which the appeared, compared with that without Post-. The Post- had less sensitivity(18 vs 96%), but greater specificity (97 vs 59%) and a positive predictive value (60 vs 39%) in predicting successful ablation compared with seen only during the RF delivery. It is concluded that the presence of Post- might be a reflection of the intense effect of RF energy on the nodal or peri-nodal tissue. (Jpn Circ J 1999; 63: 865 - 872)

抄録全体を表示

To evaluate the changing paradigms of periprocedural antithrombotic management in neuroendovascular therapy in Japan, we analyzed the details of the current periprocedural antithrombotic therapy and compared it with those of the previous generations. We retrospectively analyzed the data from the Japanese Registry of Neuroendovascular Therapy (

-NET) 3, a nationwide survey in Japan for neuroendovascular therapy between January 2010 and December 2014. A total of 26,233 patients underwent endovascular treatments to usually perform periprocedural antithrombotic therapy were retrospectively analyzed. We compared the results of -NET 3 with those of -NET 1 (January 2005 and December 2007) and -NET 2 (January 2008–December 2009). Post-procedural anticoagulant therapy was less utilized in -NET 3 than in -NET 2 (53.9% vs. 60.6%, P <0.001). Pre-procedural antiplatelet therapy became more frequent and more intensive with each generation. The frequency of aggressive therapy (dual, and triple or more therapy) was 65.2% in -NET 3, which was significantly higher than that of -NET 1 and -NET 2 (41.5% and 61.2%, respectively, P <0.001). However, periprocedural ischemic complications (2.0% vs. 5.8%, P <0.001) significantly increased, despite aggressive antiplatelet therapy. Neuroendovascular periprocedural antithrombotic therapy is focused more on antiplatelet therapy than on anticoagulant therapy. Currently, antiplatelet therapy is more frequently used with a larger number of multiple agents, however, periprocedural ischemic complications significantly increased.

抄録全体を表示

In treating ruptured vertebral artery dissecting aneurysms (VADAs), neuroendovascular therapy (NET) represented by coil obliteration is considered to be a reliable intervention. However, there has been no multi-center based study in this setting so far. In this article, results of NET for ruptured VADA obtained from Japanese Registry of Neuroendovascular Therapy (-NET) 1 and 2 were assessed to elucidate the factors associated with favorable outcome. A total of 213 in -NET1 and 381 patients in -NET2 with ruptured VADA were included, and they were separately analyzed because several important datasets such as vasospasm and site of dissecting aneurysms in relation to the posterior inferior cerebellar artery (PICA) were collected only in -NET1. The ratio of poor World Federation of Neurosurgical Societies (WFNS) grade (4 and 5) was 48.8% and 53.9%, and the ratio of favorable outcome (modified Rankin scale, mRS 0 to 2) at 30 days after onset was 61.1 % and 49.1% in -NET1 and 2, respectively. In both studies, poor WFNS grade and procedural complication were independently correlated as negative factors for favorable outcome. In -NET1, PICA-involved lesion was also designated as a negative factor while elderly age and absence of postprocedural antithrombotic therapy was detected as other negative factors in -NET2. The ratios of favorable outcome in poor grade patients were 25.4% in -NET1 and 31.3% in -NET2, which seemed compatible with the previous studies. These results may provide a baseline data for the NET in this disease and could be useful for validating the benefits of novel devices.

抄録全体を表示

Diesel rail cars in Japan have played a major role in transportation on mountainous lines. However, their efficiency of current transmission is low and their running speed is slow, because they run by hydraulic stage of current transmission. The authors built a new transmission system equipped with two direct stages of claw clutch. The transmission was tested in RTRI, . Recently, they built two transmission systems improved upon a previous transmission with reference to the test result. The transmissions were installed in a standard diesel railcar of . and tested on a mountainous main line of after a test in RTRI, . The test result was satisfactory. The running efficiency of diesel rail cars will be improved greatly thyough the adoption of this transmission.

抄録全体を表示

Recently, the rescue robot contest has been carried out in order to improve the rescue technology and to enlighten the rescue activity. Moreover, an approach on the rescue robot contest . (Rescon .) has already tried for junior high schools, which is based on the relationship of technology education.
In this paper, a simple vibration sensor for the rescue dummy which has utilized in the Rescon . is introduced. The main feature of the proposed sensor is that one can product it easily and cheaply.

抄録全体を表示

We aimed to clarify the outcomes of carotid artery stenting (CAS) in the Japanese population. For this purpose, we reviewed data from the Japanese Registry of NeuroEndovascular Therapy 3 (

-NET3), a retrospective, nation-wide, multi-center, observational study of neuroendovascular treatments in Japan. Of the 9207 patients who underwent CAS between January 2010 and December 2014, 8458 satisfied the inclusion criteria for our analysis. The outcome statistics of this -NET3 cohort were compared to those of -NET1 and 2 cohorts fitting the same inclusion criteria. Of the 8458 -NET3 patients analyzed, 8042 (95.1%) were treated by surgeons with board certification from the Japanese Society for NeuroEndovascular Therapy. Technical success was achieved in 8417 patients (99.5%), whereas 198 patients (2.3%) had clinically significant complications (CSCs). These findings mirrored those obtained for the -NET1 and 2 cohorts. On multivariate analysis, risk factors for CAS-associated CSC included symptomatic lesion [odds ratio (OR), 1.91; 95% confidence interval (CI), 1.23–3.00; P = 0.003] and hypoechoic lesion on carotid artery ultrasound (OR, 1.85; 95% CI, 1.21–2.84; P = 0.005), whereas use of closed-cell stents was a predictor of better outcome (OR, 0.53; 95% CI, 0.35–0.79; P = 0.002). The findings of -NET3 reflect good outcomes of CAS, but non-modifiable risk factors reflecting lesion characteristics remain of concern. Using closed-cell stents is advisable. Technological advances such as the introduction of new materials may help further improve CAS outcomes in Japanese patients.

抄録全体を表示

To evaluate current perioperative antithrombotic management in neuroendovascular therapy in Japan, we analyzed perioperative anticoagulant and antiplatelet use in various procedures and examined their relationships with periprocedural adverse events. Patient’s data from nationwide surveys administered by the Japanese Registry of Neuroendovascular Therapy (-NET) between January 2005 and December 2007 (-NET1) and January 2008 and December 2009 (-NET2) were retrospectively analyzed. Compared to -NET1, the frequency of perioperative antiplatelet therapy and dual or triple therapy were increased for either aneurysm coiling and percutaneous transluminal angioplasty or stenting in -NET2. Although ischemic complications were significantly decreased (4.2% vs. 2.1%, p < 0.001), hemorrhagic complications (2.1% vs. 5.3%, p < 0.001), severe adverse events (1.5% vs. 2.1%, p < 0.001), and total perioperative complications (8.3% vs. 10.3%, p < 0.001) were significantly increased in -NET2. The rate of hemorrhagic complications was significantly higher in patients with triple or more perioperative antiplatelet therapy (preoperative: 5.3% vs. 9.2%, p < 0.0001, postoperative: 5.7% vs. 12.7%, p < 0.0001). Perioperative antithrombotic therapy was performed more frequently and intensively in neuroendovascular therapy in Japan. While ischemic complications were decreased, hemorrhagic complications and severe adverse events were increased. These results suggest that intensive antithrombotic therapy has a potential risk of hemorrhagic complications for Japanese patients.

抄録全体を表示

Various observed characteristics of the six types of stress-affected remanent magnetization of igneous rocks are theoretically derived for a model rock in which a large number of ferrimagnetic minerals having an isotropic magnetostriction are distributed at random.
For small magnetic fields (H) and small uniaxial compressions (P) irreversible displacements of 90° domain walls alone are subjected to a uniaxial compression in the acquisition process of remanent magnetization. Hence Rayleigh's law of the magnetic hysteresis loop is adopted in examining the effect of H and P on the displacement of 90° walls.
Results of calculations based on these assumptions give theoretical curves of (P₊P₀H₊H₀) vs P/H, (H₊H₀P₊P₀) vs P/H, (H₊P₊P₀H₀) vs H/P, (P₊H₊P₀H₀) vs H/P, (H₊P₊P₀H₀) vs H/P and (P₊H₊H₀P₀) vs H/P. These theoretical curves reasonably well fit the observed curves, having all observed characteristics of respective types of stress-affected remanent magnetization. The effect of P on the remanent magnetization is a little smaller in the case of P⊥H than in the case of P//H in both the experiment and the theory. However, numerical disagreement between experimental and theoretical results are still noticed in regard to details of the phenomena.

抄録全体を表示

Male Dahl salt-sensitive hypertensive (S) rats develop hypertension faster than females. We measured renal α₂-adrenergic receptor density of inbred Dahl salt-sensitive (SS/) and salt-resistant (SR/) rats, using [³H]-rauwolscine saturation binding studies. Male and female SS/ rats were gonadectomized or sham-operated at 6 weeks of age and fed a high salt diet for 4 weeks. Additional intact SS/ and SR/ rats of both sexes were fed the high salt diet for a longer period of time (7 weeks instead of 4 weeks). Both blood pressure and renal α₂-adrenergic receptor density were significantly higher in male than female SS/ rats on high salt diet for 4 weeks. Gonadectomy did not change blood pressure nor did it change renal α₂-adrenergic receptor density measured at the 4th week of high salt feeding in either male or female SS/ rats. When the SS/ rats were fed high salt diet for a longer period (for 7 weeks), blood pressure of female SS/ reached the level of males, but the density of renal α₂-adrenergic receptors was still significantly lower than that of males. Both renal α₂-adrenergic receptor density and blood pressure were higher in male than female SR/. We conclude that higher blood pressure in male Dahl SS/ and SR/ rats is associated with higher renal α₂-adrenergic receptor density compared with their female counterparts. (Hypertens Res 1996; 19: 83-89)

抄録全体を表示

（a－）型は，まれな血液型の中で最も供給頻度が高い血液型である．我々は北関東約40万人の献血者にJr^a抗原のスクリーニング検査を行い（a－）型の頻度と抗Jr^a保有率，及び抗体価の分布について検討した．検出した（a－）型は男性が献血者238,797中134人，女性が159,263中104人，計238人で検出頻度は0.06%で男女差はなく，他地域との差も認めなかった．また，抗Jr^aを保有する（a－）型は35人（33.7％）で，すべて女性で，妊娠・出産による免疫抗体と考えられた．これらの献血者が保有する不規則抗体は33人（94.3％）が抗Jr^a単一の抗体であった．抗Jr^aの抗体価は8倍から512倍まで分布しており最も多いのは256倍の12名であった．35例の抗Jr^aのうち，IgGサブクラスを分類することができた14例は，すべてIgG1陽性で3例はIgG3弱陽性の共存例であった．

抄録全体を表示

Fig. 4 Wrong:Dr. Warren . (right) and Dr. Marshall B.J. (left).
Right:Dr. Warren . (left) and Dr. Marshall B.J. (right).

抄録全体を表示