Residential gas-fired absorption heat pump based on R 22-DEGDME pair. Part 1 thermodynamic properties of the R 22-DEGDME pairLa pompe à chaleur à absorption à brûleur à gaz pour les locaux résidentiels utilisant le couple R 22-DEGDME. 1e partie. Propriétés thermodynamiques du couple R 22-DEGDME

R 22-DEGDME is chosen as the prime working fluid pair for residential gas-fired absorption heat pumps.The vapour pressures and the heat capacities of mixtures are measured for various concentrations and temperatures and are correlated by a Rankine equation and a polynomial, respectively. The heats of mixing are measured at 10°C, and are correlated by a Redlich-Kister type polynomial.Based on these data, the pressure-temperature-concentration diagram and the enthalpy-concentration diagram are drawn, which make analysis of the absorption cycles possible.     

Elimination of ioversol by hemodialysis

PURPOSE: The dialysability of ioversol was investigated in 12 patients with chronic renal failure, on 4-h hemodialysis. MATERIAL AND METHODS: One hundred ml of ioversol (320 mg I/ml) was injected in less than 10 min during CT. Hemodialysis was commenced within 30 min of starting the contrast medium injection and was continued for 4 h. Blood was sampled before and at 15 min, 30 min, 1 h, 2 h, and 4 h after the start of hemodialysis. Mean dialysance of ioversol was 114 to 129 ml/min and the elimination rate was 82.5 +/- 5.1% 4 h after starting hemodialysis. The half-life of ioversol during hemodialysis was 1.80 +/- 0.38 h. The only side effects of the ioversol injection were heat sensations, which were experienced by 3 patients. RESULTS: As ioversol was effectively removed from the body during the 4 h of hemodialysis and no severe adverse reactions were observed, we conclude that ioversol is suitable for use in hemodialyzed patients.     

Structures of spider toxins: hydroxyindole-3-acetylpolyamines and a new generalized structure of type-E compounds obtained from the venom of the Joro spider, Nephila clavata

Facile structure determination of acylpolyamines, glutamatergic nerve blocker obtained from the venom of the Joro spider (Nephila clavata) was carried out with the use of micro-column LC/MS and high energy collision induced dissociation (CID) mass spectrometry. 6-hydroxyindole-3-acetyl was proposed previously as a putative partial structure, for the acyl moiety of hydroxyindole-type polyamines (NPTX-1 to -6). The NMR data obtained for NPTX-6, NPTX-687 and hydroxyindole-3-acetic acid which was released by acid hydrolysis of Nephila clavata crude venom extracts proved that the lipophilic head is the 4-hydroxyindole-3-acetic acid. Various hydroxyindole-3-acetyl polyamines were found in N. Clavata venom and characterized by mass spectrometry. As a result, type-E, a new class of generalized acylpolyamine structure was proposed in addition to the previously reported polyamine backbones type-A to -D.     

Gene transfer into muscle by electroporation in vivo

Among the nonviral techniques for gene transfer in vivo, the direct injection of plasmid DNA into muscle is simple, inexpensive, and safe. Applications of this method have been limited by the relatively low expression levels of the transferred gene. We investigated the applicability of in vivo electroporation for gene transfer into muscle, using plasmid DNA expressing interleukin-5 (IL-5) as the vector. The tibialis anterior muscles of mice were injected with the plasmid DNA, and then a pair of electrode needles were inserted into the DNA injection site to deliver electric pulses. Five days later, the serum IL-5 levels were assayed. Mice that did not receive electroporation had serum levels of 0.2 ng/ml. Electroporation enhanced the levels to over 20 ng/ml. Histochemical analysis of muscles injected with a lacZ expression plasmid showed that in vivo electroporation increased both the number of muscle fibers taking up plasmid DNA and the copy number of plasmids introduced into the cells. These results demonstrate that gene transfer into muscle by electroporation in vivo is more efficient than simple intramuscular DNA injection.     

Intravascular ultrasound in determining the end point of percutaneous transluminal coronary angioplasty

Intravascular ultrasound (IVUS) imaging was used to measure internal luminal area immediately after percutaneous transluminal coronary angioplasty (PTCA) in 83 patients (59 males, 24 females, mean age 63 +/- 12 years) with angina pectoris to determine the need for additional intervention. The effectiveness of these interventions to prevent restenosis was also studied. Thirty-five patients (42%) with insufficient dilatation revealed an internal luminal area less than 5 mm2 or luminal stenosis greater than 60% as evaluated by IVUS imaging following the procedure. The luminal area increased from 4.5 +/- 1.1 to 7.9 +/- 2.8 mm2 and the percentage luminal stenosis improved from 66 +/- 9% to 54 +/- 9% in patients who underwent further dilatation with a larger size balloon, longer dilatation time, directional coronary atherectomy, or stenting. The insufficient dilatation group exhibited hard plaque and calcification more frequently than in the other group (48 patients, 58%) in whom sufficient dilatation of the target lesion was achieved. The incidence of restenosis in the sufficient dilatation group was 25%, compared to 33% of the patients receiving additional treatment after IVUS imaging and 42% in the 192 patients who underwent PTCA without IVUS imaging. IVUS imaging is a useful method for evaluation of complex luminal morphology to decrease the incidence of restenosis and for determination of the end point and the extent of dilatation required.     

Distribution of bile acids in rats

Distribution and biliary and fecal excretion of bile acids were examined in Wistar strain male rats of about 300 g body weight. The pool size of the rats on ordinary diet was 40 mg/rat, biliary secretion was 14 mg/hr, and fecal excretion was 10 mg/day. Bile acids were mainly located in the small and large intestinal contents, 87% and 10%, respectively; but a portion was found in the intestinal wall and the liver. Rats fed 2% cholesterol-supplemented diet for a week showed similar values for pool size and biliary secretion with the rats on ordinary diet, but higher values for fecal excretion and distribution ratio in the large intestinal contents. Cholic acid was a major component in the bile, small intestinal wall, small intestinal content and liver, while the bile acid composition ratios were roughly similar to each other, although a relatively large amount of α-muricholic acid was found in the intentinal wall and liver. Both the wall and content compositions of the large intestine were similar to that of the feces, in which lithocholic, deoxycholic, α- and β-muricholic acids were the main components, although the ratios of α- and β-muricholic acids in the large intestinal wall were larger than those in the intestinal contents or feces. The high concentrations of these bile acids may indicate a difference of transport velocity across the cell membrane, but the mechanism is not known.     

Design of multivariable feedback systems with infinite gain margin and decoupling

This letter discusses the problem of designing a feedback compensator that attains the infinite gain margin under the uncertainties of feedback gains. A sufficient condition is given for the existence of compensators and then it is shown that the condition becomes necessary subject to the requirement that the feedback system is decoupled. The nonlinear case is also discussed.     

Deformation behaviour of aluminium macrocrystals in the grain boundary region

Lattice distortions of deformed aluminium macrocrystals were observed by Electron-microprobe-Kossel techniques. Grain boundary effects due to deformation appeared in various ways such as extraordinary separation and branching of Kossel lines, and as intergranular rotation of the grains in pseudo-Kossel X-ray diffraction patterns obtained from the grain boundary regions of the specimens. Such distortions of the patterns peculiar to the grain boundary regions were attributed to the effect of local slipping induced by the active slip systems of the neighbouring crystals. By the interpretation of these patterns and the orientation relationships between neighbouring grains, it was found that the local slipping was induced towards the slip direction of the active slip plane in the neighbouring crystals, or induced by a type of local stress along the slip direction of the active slip planes in the neighbouring crystals. It was also recognised that at an early stage of stressing, deformation bands were produced in the grain boundary region as a result of a grain boundary effect.     

Cutoff frequencies of vector wave modes in cladded inhomogeneous optical fibre

Asymptotic vector wave formulas for calculating the cutoff frequencies in optical fibres with graded-index core and uniform cladding are derived. Numerical examples are given in comparison with the scalar wave solutions, in order to show that the mode degeneracy present in the regime of scalar wave approximations is removed and the cutoff values in degenerate states split slightly.