Dicrotic pulse observed in a patient with prolapse of the aortic valve without aortic regurgitation

We describe a case of dicrotic pulse in a patient who exhibited marked prolapsed aortic cusp without aortic regurgitation. Echo-Doppler in the abdominal aorta showed deep reversal flow confined to early diastole. We conclude that this prolapse was the cause of the steep dicrotic notch and the dicrotic pulse, because of the concomitance of non-leaking aortic valves.     

The cause of polyurethane catheter cracking during constant infusion of etoposide (VP-16) injection

We studied the cause of cracking of a clinically used polyurethane (PU) catheter during the constant infusion of etoposide (VP-16) injection (Lastet), administered without dilution to patients as a part of combination high-dose chemotherapy. After VP-16 injection was infused into the PU catheter at a constant infusion rate (30 ml/h) for 24 h, a decrease in the elasticity (36% of untreated) and on increase in the length of the catheter (3.7%) were observed. These changes were significantly higher than those treated with the control saline. The similar changes of the PU catheter were observed after treatment with a basal solution containing polyethylene glycol 400 (PEG 400), polysorbate 80 and ethanol, which is the vehicle of the VP-16 injection, and with ethanol alone. Moreover, obvious degeneration of the internal wall (occurrence of spots like melting) and cutting face (micro-cracking) of the catheter was observed with an electron microscope after treatment with the vehicle. On the other hand, the elasticity or extension of the PU catheter were not changed after treatment with saline or PEG 400. From these findings, it was suggested that the degeneration and subsequent cracking of the PU catheter during the infusion of VP-16 injection was caused by ethanol contained in its injection solution. No cracking or morphological changes of polyvinyl chloride (PVC) and silicone catheters were found after treatment with the vehicle solution. However, since it has been reported in previous reports that di(2-ethylhexyl)phthalate was leached from PVC bags, the high dose chemotherapy with the dilution-free VP-16 injection should be achieved safely and effectively using a silicon catheter, rather than the PU catheter.     

A low-threshold polarization-controlled vertical-cavitysurface-emitting laser grown on GaAs (311)B substrate

We have demonstrated a GaAs (311)B vertical-cavity surface-emitting laser (VCSEL) with a threshold current as low as 250 μA, which is the lowest value ever reported for that on non-(100) oriented substrates. Also, the fabricated VCSEL shows a stable polarization state for wide during current ranges and a large polarization-mode suppression ratio over 30 dB between the [2¯33] and [011¯] axis modes at 5 mA. The electrical specific resistance of 1.2×10^-4 Ω·cm^-2 at the threshold was reasonably low due to carbon autodoping to AlAs in a p-type distributed Bragg reflector (DBR)     

Application of GPT to tanδ measuring apparatus fordistribution cable in hot line

A hot line tanδ measuring apparatus which uses the secondary voltage of GPTs (grounding potential transformers) existing at substations and other facilities has been developed. An error vector circle diagram method which allows one to determine the value of tanδ to an accuracy of 0.1%, notwithstanding the phase difference existing between the primary and secondary voltages of a GPT, is described. The method was used in field experiments with favorable results. The method is especially superior in terms of safety and operability because no contact with high-voltage portions is required     

GaInAsP/InP DH lasers with a chemically etched facet

We describe a new configuration and novel fabrication method for GaInAsP/InP DH lasers in which one of the facet mirrors is chemically etched and the other one is formed by cleaving. The etched facet is fabricated monolithically by wet chemical etching in a solution of HCl:CH3COOH:H2O2= (1:2:1). Broad-area contact lasers of this type operating at room temperature at a wavelength ofsim 1.3 mum have been demonstrated.     

Tunnel Junction with Autodoped AlGaAs on InP

We describe the low resistance of tunnel junction structures with a p ⁺-AlGaAs layer grown on an InP substrate using the autodoping technique. An Al_0.4Ga_0.6As layer showed a hole concentration of 2.4 × 10²⁰ cm^?3 without additional material sources. We demonstrated that the proposed tunnel junction structure with a p ⁺-Al_0.4Ga_0.6As/In_0.52Al_0.48As multiple-quantum-well layer on an InP substrate exhibited a low resistance of 2.5 × 10^?5 Ω cm², as estimated from reverse current–voltage characteristics, and a tunnel peak current density of 170 A/cm².     

Lasing characteristics of InGaAs-GaAs polarization controlledvertical-cavity surface-emitting laser grown on GaAs (311) B substrate

We have demonstrated an oxide confinement polarization controlled vertical-cavity surface-emitting laser (VCSEL) grown on a GaAs (311)B substrate. The polarization state was well controlled along the [2¯33] crystal direction due to an anisotropic gain in the (311)B plane. We fabricated a small oxide aperture VCSEL with a threshold of 260 μA and realized single-transverse mode and single-polarization operation for the first time. The sidemode suppression ratio (SMSR) was 35 dB and the orthogonal polarization suppression ratio (OPSR) was 25 dB. In addition, we have measured polarization and transverse mode characteristics of multi- and single-transverse mode devices under high-speed modulation. In the multimode device of 12 μm×12 pm oxide aperture, we have achieved stable polarization operation of over 25-dB OPSR up to 10 Gb/s and have observed no power penalty due to polarization instability under 2.5-Gb/s pseudorandom modulation. The single-mode device showed stable single-transverse mode and polarization under the modulation conduction up to 5 GHz of sinusoidal modulation. SMSR and OPSR were over 30 and 10 dB, respectively     

Temperature dependence of GaAs/AlGaAs multiquantum barrier lasers

A GaAs/AlGaAs laser loaded by a multiquantum barrier (MQB) is reported, and its temperature-threshold characteristic has been systematically examined. It has been found that this characteristic is improved by introducing the MQB, and this improvement is reflected in the barrier height. The actual barrier heights of a MQB-loaded structure under biased conditions are also discussed, considering the Fermi level in the MQB region     

Hsp90 Activity Is Necessary for the Maturation of Rabies Virus Polymerase

Mononegavirales is an order of viruses with a genome in the form of a non-segmented negative-strand RNA that encodes several proteins. The functional polymerase complex of these viruses is composed of two proteins: a large protein (L) and a phosphoprotein (P). The replication of viruses from this order depends on Hsp90 chaperone activity. Previous studies have demonstrated that Hsp90 inhibition results in the degradation of mononegaviruses L protein, with exception of the rabies virus, for which the degradation of P protein was observed. Here, we demonstrated that Hsp90 inhibition does not affect the expression of rabies L and P proteins, but it inhibits binding of the P protein and L protein into functional viral polymerase. Rabies and the vesicular stomatitis virus, but not the measles virus, L proteins can be expressed independently of the presence of a P protein and in the presence of an Hsp90 inhibitor. Our results suggest that the interaction of L proteins with P proteins and Hsp90 in the process of polymerase maturation may be a process specific to particular viruses.