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An automatic power-generating system (AGS) which converts kinetic energy into electric energy for quartz watches was tested as a power source for implantable cardiac pacemakers. An automatic power-generating mechanism and a capacitor (0.33 F) were removed from a quartz watch (SEIKO) and encapsulated in a polyvinyl case. Characteristics of the AGS were investigated by acceleration equipment. The capacitor in the AGS was charged to 2.0 V (0.66 J) by placing it on the equipment for about 30 minutes. The equipment has a 2 Hz cycle and generates +/- 1.7 G at the end of each half cycle. The AGS (fully charged to 2.0 V) was used as the power source for a pulse generator circuit built using commercially available CMOS IC. The circuit generated pulses of 0.5 ms width at 1 Hz (60 pulses min-1). The voltage of the AGS was maintained at 1.6 V while it was being charged by the accelerations. The generator supplied pulses of 0.75 V, 1.47 mA through a 510 omega load. With fully charged AGS, the generator was also used to pace a mongrel dog's heart at 140 beats min-1 for 60 minutes. During pacing, the AGS supplied 420 mJ to the circuit and the cardiac muscle. The AGS was placed on the right ventricular wall of the mongrel dog under anaesthesia. Energy of 80 mJ is stored in a capacitor by the heart beating at about 200 beats/min for 30 minutes. Thus the AGS generated 13 microJ per heart beat. This result suggests that the AGS may supply enough energy for use in a cardiac pacemaker.

Chemie CommunicationsThe spectroscopic and X-ray crystallographic properties of a highly conductive neutral mixed-valence rhodium(i,ii) semiquinonato/catecholato complex in which the mixed-valence states are formed by electron transfer between rhodium d and semiquinonate p* orbitals are reported by M. Mitsumi, K. Toriumi et al. in the Communication on the following pages.

Pentazocine (PTZ), a narcotic-antagonist analgesic, is widely used in the management of patients with postoperative pain or initial carcinogenic pain.1) PTZ is a cationic drug having physicochemical properties of high lipophilicity, 2) and immediately reaches the brain in rats when the drug is administered parenterally. 3,4) In rats, brain-plasma concentration ratio is relatively constant, and PTZ concentration in the brain is much higher than that in the corresponding plasma. 5,6) The blood-brain barrier (BBB) appears to have little restricting effect on the uptake of this drug by the brain after parenteral administration in rats.We recently demonstrated that the major factor governing the uptake of PTZ into the brain was not only nonsaturable process but also carrier-mediated transport with a low-affinity saturable process, using the in situ rat brain perfusion technique.7) The advantage of this in situ technique is the high sensitive ability to estimate the kinetic parameters representing the individual rate process. 8,9) Moreover, this technique has greater advantages to the use of perfusate because the composition and flow rate can be adjusted according to the needs of the individual experiments. 8,9) However, this technique is too complex technically, because at least 3 arteries and veins must be ligated before perfusion. 8,9) On the other hand, the carotid injection technique can maintain the cerebral endothelial cells and vasculature of a brain in their normal physiological states and anatomical positions in the animal. Furthermore, the carotid injection technique is technically simpler than the brain perfusion technique. 8,9) Therefore, we investigated the influx transport mechanism of PTZ at the BBB in rats using the carotid injection technique, and compared the results with those from the in situ perfusion technique. The composition of Sosegon ® injection was PTZ (30 mg), lactic acid (12 ml) and sodium chloride (2.8 mg) in 1 ml of distilled water for injection. The PTZ powder used as a free base was from Kobayashi Kako Co., Ltd. (Fukui, Japan), which was used to adjust the drug concentration of the injection solution after dissolving in 0.1 M hydrochloric acid. Xylazine hydrochloride (Sigma Chemical Co., St. Louis, MO, U.S.A.) and ketamine hydrochloride (Ketaral ® 50; Sankyo Co., Ltd., Tokyo, Japan) were used as anesthetics. Amantadine hydrochloride, choline chloride, cimetidine, desipramine hydrochloride, ketotifen fumarate salt, hemicholinium-3, imipramine hydrochloride, lidocaine hydrochloride, mepyramine maleate, naloxone hydrochloride, propranolol hydrochloride and tetraethylammonium chloride (TEA) were purchased from Sigma Chemical Co. (St. Louis, MO, U.S.A.). Diphenhydramine hydrochloride, phenylalanine and HEPES were obtained from Wako Pure Chemical Industries, Ltd. (Osaka, Japan). Procainamide hydrochloride was purchased from Aldrich Chemical Co., Inc. (Milwaukee, WI, U.S.A.). Buprenorphine hydrochloride (Lepetan injection) was purchased from Otsuka Pharmaceutical Co., Ltd. (Tokyo, Japan), bu...

ABSTRACT:Methods for the chemical recycling of polycarbonate (PC) wastes in the forms of bisphenol A (BPA) and cyclic heterocarbonates, such as 1,3-dithiolan-2-one (DTO), 1,3-dithiane-2-one (DTA), and cyclic unsymmetric heterocarbonates, were investigated to prove that PC can be utilized as a phosgene equivalent for industrial purposes. Treatment of PC pellets or waste PC compact discs with 1,2-ethanedithiol and a catalytic amount of base (e.g., 1.5 mol % NaOH) in dioxane for a short period at 40°C produced DTO and BPA, both in nearly quantitative yields. The reaction could also be carried out in DTO, which saved the use of conventional solvents. Other cyclic heterocarbonates, that is, DTA, 1,3-oxathiolan-2-one, 1,3-thiazolidine-2-one, and N-methyl-1,3-oxazolidine-2-one, were prepared in high yields under analogous conditions.

835YAKUGAKU ZASSHI 135(6) 835-840 (2015) It has been reported that magnesium oxide tablets are excreted in a non-disintegrated state in the stool of patients when the tablets are administered after being immersed in a food thickener. Therefore we examined whether immersion in a food thickener aŠects the pharmacological eŠect in patients taking magnesium oxide tablets, and whether immersion aŠects its disintegration and solubility. The mean dosage (1705 mg/d) was higher for patients who took tablets after immersion in a food thickener than for those who took non-immersed tablets (1380 mg/d). The disintegration time and dissolution rate of the immersed tablets were lower than those of non-immersed tablets in vitro. Furthermore, components that constitute the food thickener and diŠerences in composition concentrations diŠerentially aŠect the disintegration and solubility of magnesium oxide tablets. This suggests that commercially available food thickeners are likely to be associated with changes in the degradation of magnesium oxide tablets, and they therefore should be carefully used in certain clinical situations.

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The adsorption of tungsten hexafluoride (WF6) and monosilane (SiH4) in selective chemical-vapor deposition (CVD) of tungsten (W) is investigated in situ using Fourier-transform infrared reflection and transmission absorption spectroscopy (FTIR RAS and TMS). The selectivity for W growth is found to originate from the dissociation of SiH4 on a W surface. That is, SiH4 dissociates on a W surface to form Si-containing adsorbed species when the W surface is exposed to SiH4 at temperatures higher than 110 °C, whereas SiH4 does not dissociate on a SiO2 surface. On the other hand, when W and SiO2 surfaces are exposed to WF6 at temperatures from 20 to 300 °C, no adsorbed species are observed by FTIR RAS. However, WF6 can easily react with the Si-containing adsorbed species on a W surface to form W and byproduct gases of SiHF3 and SiF4. The main surface reaction of selective W CVD can be expressed as WF6+2SiH4=W+2SiHF3+3H2. These experimental results support the selective W-CVD mechanism previously proposed, which shows that dissociation of SiH4 and not the dissociation of WF6 has a central role in this process.