The 100 G capturing robot - too fast to see

This paper discusses the capturing robot with the maximum acceleration of 100 G in design specification. We aim find the combination of the arm with a mass of 0.1 kg and the spring capable of producing the initial compressed force of 100 N, in order to achieve the 100 G. To reduce the total capturing time, we propose an arm/gripper coupling mechanism where the spring energy initially accumulated in the arm is transferred to the kinetic energy of the arm and continuously to the kinetic energy for closing the gripper at the capturing point without any time lag. The experimental results show the maximum acceleration of 91 G and the capturing time of 25 ms were achieved. Experiments on capturing a dropping ball were also executed with the assistance of the 1 ms-vision.     

Can EC-IC bypass prevent brain ischemia from recurring?

The effectiveness of extracranial-intracranial arterial bypass (EC-IC bypass) surgery for patients with hemodynamic compromise still remains controversial. In the present study, we evaluated the correlation between the pre- and post-surgical cerebral hemodynamics and long-term prognosis. 28 patients and a subsequent 21 patients (41 men, eight women: mean age 59.9 [S.D. 8.6] years) with reduced cerebrovascular reserve due to steno-occlusive disease of the cerebral major arteries formed the study groups 1 and 2, respectively. Measurement of the mean hemispheric cerebral blood flow (mCBF) and the cerebral vasoreactivity (%mCVR) with an intravenous acetazolamide injection were performed by a 133Xe inhalation method and SPECT. Patients were treated with EC-IC bypass surgery and measurement of mCBF and %mCVR were made again about one month after surgery. The patients were observed for a long period (mean 44.3 months). During the follow-up period, 6 patients experienced recurrent ischemic strokes. The annual incidence of recurrent ischemic stroke was 4.4%. The patients with significantly reduced pre- and post-surgical resting mCBF of the affected hemisphere were at significantly higher risk of recurrent ischemic stroke than the patients with normal mCBF (p < 0.01). The %mCVR of the affected hemisphere rose after surgery.     

Disaccharide analysis of human skin glycosaminoglycans in sun-exposed and sun-protected skin of aged people

The negative conduction effect of quinidine on each of the successive phases of the ventricular depolarization was investigated using an original noninvasive method: the spatial velocity electrocardiogram of the QRS complex (SVECG-QRS). We performed a randomized placebo-controlled trial in 10 healthy subjects with a single oral dose of quinidine (330 mg) or placebo. Electrocardiographic acquisition and processing (220 recordings for the complete trial) were performed using the Lyon vectorcardiographic program. For each SVECG-QRS curve, the position of seven specific points from A (onset of QRS) to G (end of QRS) were determined precisely. The six successive time intervals between these points (AB-FG) and five velocity values (B-F) were then calculated. The QRS complex was longer under quinidine than placebo (102.4 +/- 1.6 vs. 100.3 +/- 1.5 ms). The difference was at the periphery of statistical significance (p = 0.05), and this lack of statistical difference may be mainly due to the low serum levels of quinidine obtained at the peak of the concentration (1.46 +/- 0.4 mg/1). All six QRS time intervals were longer under quinidine, but only the BC interval was significantly different (9.3 +/- 1.1 vs. 18.8 +/- 1.1 ms; p < 0.05) suggesting a more pronounced negative conduction effect at the onset of ventricular depolarization. No significant modifications were observed for the velocity values. We conclude that (1) the negative conduction effect of quinidine is heterogeneous, but a further study with a higher dose of quinidine (concentration-dependent effect) is required to confirm this hypothesis and (2) the spatial velocity electrocardiogram of the QRS complex allows a detailed analysis of the ventricular conduction phases. The results of the measurement were found to be reproducible. This noninvasive tool could be used in clinical practice to assess effects of antiarrhythmic drugs on successive ventricular depolarization phases.     

Structural change in diamond by hydrogen plasma treatment at room temperature

The structural change of diamond induced by hydrogen plasma exposure at room temperature, and its thermal stability, were investigated using electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) techniques. ESR observation revealed that it gave rise to a highly defective structure (spin concentration of 10²⁰ cm^{− 3}), which is very similar to the structure of hydrogenated amorphous carbon (a-C : H) confirmed by XPS and FTIR. Post-annealing was also carried out to clarify the thermal stability of the defects. The number of spin centers decreased with increasing annealing temperature, and eventually, the defective structure changed to a graphitic one by annealing at 800 °C.     

Stability of large-scale coal-fired MHD channels

Stability of large-scale coal-fired MHD channels is studied by (1) linearized stability analysis, and (2) time-dependent 1-D analysis. The channel length is 15 m with 600 electrode pairs, and the output power ranges from 220.6 MW through 258.7 MW. Linearized stability analyses show that the Faraday channels operated with fixed loading resistance are stable, whereas the two waves of u and u–a (u, a: gas and sound velocity) become unstable in the Faraday channel with fixed loading factor. Two waves of u and u–a are unstable in the diagonal channel with fixed loading current and the u + a wave becomes unstable in the diagonal channel with fixed electrode current. Time-dependent one-dimensional analyses indicate that the Faraday channels with fixed load resistance are smooth without growth of fluctuation. The diagonal channels with fixed electrode current are smooth with no fluctuation, though the linear theory indicates that the u + a wave is unstable. The diagonal channel with fixed load current suffers large disturbance along the latter half of the channel, being consistent with the linearized analysis which indicates that the u - a and u waves are unstable.     

HLA-A26 subtype A pockets accommodate acidic N-termini of ligands

BACKGROUND: Fiberoptic flexible sigmoidoscopy (FFS) is routinely requested preoperatively as part of evaluation of pelvic masses to exclude colonic involvement by the tumor or concurrent colonic neoplasm. The aim of our study was to evaluate the utility of preoperative FFS in patients with suspected gynecologic malignancy. METHODS: FFS, performed using a 60 cm sigmoidoscope, evaluated (1) presence of bowel involvement by the tumor, (2) extrinsic compression by the tumor, and (3) presence of colonic neoplasms. FFS findings were correlated with surgical findings. RESULTS: A total of 107 women underwent preoperative FFS and subsequent surgery. Eleven patients (11%) had lower gastrointestinal symptoms. At surgery, 63% of pelvic tumors were malignant and 37% were benign. The most common abnormality at FFS was colonic polyps in 23 patients (21%). Colonic adenomas were found in 11 patients (10%). Extrinsic compression by the tumor without mucosal abnormalities was seen in 15 patients (14%). The most common intraoperative finding was tumor adhering to the bowel in 18 patients requiring dissection, but only 1 patient required bowel resection. Eight of these 18 patients had preoperative lower gastrointestinal symptoms. All 15 patients with extrinsic compression at FFS had tumor adhering to the bowel. CONCLUSIONS: Pelvic masses cause extrinsic compression at FFS in 14% of patients. This is suggestive of tumor adherent to the bowel at surgery. However, bowel resection is rarely required because of tumor involvement. Most patients with bowel adherence by tumor have lower gastrointestinal symptoms. Colonic adenomas are found in one tenth of patients, mostly in patients older than 50 years of age. Preoperative FFS does not change the surgical management of pelvic tumors. Screening FFS is indicated in all patients with pelvic tumors over age 50, as in persons with average risk, but is otherwise unnecessary in evaluation of pelvic masses.     

Histo-pathological study of a glass-ionomer/resin (Geristore) restoration system

The purpose of this experiment was to investigate histo-pathologically the pulpal reaction to a glass-ionomer/resin (Geristore) restoration system in human teeth. Black's class I cavities were prepared in 22 human teeth; these were divided into 2 groups, one with the Geristore after cavity was cleaned with 10% NaOCl solution and 3% H2O2 solution (Group G) and the other with the Geristore after the cavity was applied with Mirage-Bond (Group MG). The treated teeth were observed clinically over 90 days after operation. They were then extracted for histological examination. No unpleasant symptoms were noted. A few pathological changes were observed. No histo-pathological score differences were observed between groups G and MG. The average evaluation score of pathological results in both groups G and MG were excellent. Microorganisms observed in the cavity dentin of the group G was fewer than in group MG. In some cases, microorganisms were observed along the dentin walls. In conclusion, the pulpal injury due to this Geristore restoration system was slight, and the system was considered to be safe for the pulp and clinically useful.