Anteroaxillary thoracotomy facilitates the use of retrograde cerebral perfusion in distal aortic arch reconstruction

Anteroaxillary thoracotomy in a 45-degree position provides an ideal view of the distal aortic arch and also makes direct superior vena caval cannulation possible for retrograde cerebral perfusion. This approach is especially useful in cases in which retrograde cerebral perfusion is indicated as an adjunct to deep hypothermic circulatory arrest in repair of the distal aortic arch.     

Two cases of intracranial epidural hematoma following open heart surgery (author''s transl)

John Hunter's contribution to the understanding of venereal disease is reviewed. Hunter's evidence for the unitary nature of these diseases is examined and the advances he made in diagnosis, pathology, and management are considered.     

Performance and maximum load capacity of uninterruptible power system using double‐layer capacitor

Power service interruptions cause problems in various facilities. Even an instantaneous voltage drop may give rise to serious problems in computer systems or electronic equipment. The uninterruptible power system (UPS) has been used to compensate for the power service interruptions. Also, the instantaneous voltage drop compensator using the electrolytic capacitor has been developed for the instantaneous voltage drop. Recently, the double‐layer capacitor has been considered as a new energy storage element. This capacitor has many advantages such as no maintenance, long lifetime, and quick charge/discharge characteristics with large current and it has higher energy density than the electrolytic capacitor. Therefore, we developed the UPS using the double‐layer capacitor. In this paper, the performance of the UPS using the double‐layer capacitor is shown by simulated and experimental results. Furthermore, the discharge characteristics of the double‐layer capacitors are investigated on the basis of the equivalent circuit including the capacitors and a voltage booster. Finally, the maximum load capacity to compensate is clarified for the system. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(3): 73–81, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20190     

Approaches to suppressing shaft voltage in brushless DC motor driven by PWM inverter

This paper describes the approaches to suppressing the shaft voltage and bearing current by electrostatically shielding the stator end windings of the brushless DC motor driven by PWM inverter. At first, measured shaft voltage and bearing current are compared with those calculated waveforms to verify the common mode equivalent circuit of the brushless DC motor. Next, the relationship between shaft voltage and stator winding to rotor capacitance is calculated using the common mode equivalent circuit. Finally, the electrostatic shielding of the stator end windings is evaluated to reduce the shaft voltage by experiments and calculations. ©2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(4): 73–79, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20701     

Retrograde cerebral perfusion exceeding 120 minutes in aortic arch reconstruction: a report of two cases

To assess the association between HLA-DRB1 and elderly-onset rheumatoid arthritis (RA) (EORA) in Japanese people, we analysed the HLA-DRB1 antigen frequencies of EORA patients. The age at onset distribution of 852 Japanese RA patients was analysed, and EORA was defined as an age at onset of 60 yr or older. Among the 852 RA patients, 120 (14.1%) were EORA patients. Their HLA-DRB1 antigen frequencies were assessed for significant deviation from those of the control (n = 652) and adult-onset RA (AORA; disease onset between 16 and 59 yr; n = 732) groups. The Japanese EORA patients were positively associated with DRB1*0101, *0405 and *1502, and the relative risks were 2.7, 1.9 and 2.2, respectively. The frequency of DRB1*1502 was also significantly higher among the EORA patients than in the AORA patients. The EORA patients showed different trends from the AORA patients in their frequency of HLA-DRB1 alleles, which suggests that EORA may be a different subset from AORA in light of its immunogenetic background.     

Mild exercise activates renal dopamine system in mild hypertensives

OBJECTIVE: The role of renal dopamine in the early depressor effect of exercise was evaluated in hypertensives. METHODS: After a general clinical observation period of 4 weeks, 29 essential hypertensives were divided into two groups. The exercise group (n=16) underwent blood lactate threshold exercise using a cycle ergometer for 60 min three times a week for 4 weeks. RESULTS: In the non-exercise group (n=13), blood pressure (BP) and humoral variables did not change significantly (from 150+/-3/93+/-2 to 145+/-2/94+/-1 mm Hg). In the exercise group (n=16), resting BP was significantly reduced from 158+/-2/92+/-2 at week 0 to 145+/-3/85+/-3 mm Hg at week 4. The increase in urinary free dopamine excretion (from 248+/-14 to 276+/-24 ng/mg Cr) at week 4 was significantly higher than that in the non-exercise group (from 220+/-31 to 196+/-27 ng/mg Cr). In the exercise group, urinary kallikrein activity also increased significantly from 173.0+/-35.4 at week 0 to 320.3+/-63.3 ng bradykinin/min/mg Cr at week 4. These changes in urinary free dopamine excretion and urinary kallikrein activity were negatively correlated with the change in BP. The change in urinary sodium excretion was also negatively correlated with the change in plasma volume index. Moreover, the change in urinary free dopamine excretion was positively correlated with the changes in urinary kallikrein activity and urinary sodium excretion. The change in renal decarboxylation rate of DOPA (3,4-dihydroxyphenylalanine) positively correlated with the changes in urinary free dopamine excretion and urinary sodium excretion, and was negatively correlated with the change in systolic BP. CONCLUSION: These results suggest that exercise triggered renal dopamine generation and activation of renal kallikrein-kinin system, resulting in natriuresis and BP reduction in the early phase (4 weeks) of mild exercise.     

Improvement of pulse pattern for space vector modulated matrix converters

Novel modulation which consists of conventional space vector modulation (SVM) based on a virtual AC/DC/AC conversion and carrier signal modulation for matrix converters is proposed. In this proposed modulation, duties for the switching pattern decided by conventional SVM are changed into those for each switch of matrix converter. The new duties for each output phase are compared with the triangle carrier. By using proposed modulation, switchings between the input phase voltage with minimum value and the voltage with maximum value are eliminated. In this paper, the conventional SVM and proposed modulation are explained. Next, for both conventional and proposed modulations waveforms of input current, output voltage and output current and their frequency spectra are calculated by PSIM simulation program. Simulation results show the proposed modulation can reduce harmonics of output voltage waveforms. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(1): 46–54, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20903     

A new synthetic fiber made of nylon 3

Nylon 3 fibers were produced by wet spinning, and properties and structures of the fibers were investigated. Fiber- and film-forming abilities of nylon 3 dopes in various coagulants, using various solvents, were investigated and it was found that only the nylon 3 spinning dope dissolved in formic acid showed excellent fiber- and film-forming abilities in coagulation baths of ethers, esters, or alcohols. As for mass transportation in these coagulants, solvent (formic acid) was diffused into coagulants, with scarce penetration of the coagulants into protofibers. This was due to the fact that these coagulants had moderate solubility parameter values and moderate proton-accepting power, which means the existence of some interaction between solvent and coagulants and no interaction between coagulants and polymer. Protofibers thus obtained were already crystallized and stretching them at room temperature was impossible. However, in such media as silicone oil, hot air, and Wood's metal, which were thought to have no interaction with polyamides, nylon 3 fibers were stretchable above their glass transition temperature (170°–180°C), while in such media as hot water, hot glycerin, and hot steam, which were thought to have some interaction with polyamides, nylon 3 fibers could not be stretched. Mechanical properties of nylon 3 fibers were as follow: strength, 2–3 g/d; elongation, 10%–20%; Young's modulus, 11 × 10⁵–17 × 10⁵ psi. High Young's modulus, high transition temperature, and high moisture regain are pointed out as characteristic features of nylon 3 fibers, compared with other synthetic fibers.     

Superstructures and phase transitions of Bi2O3

Polymorphs of bismuth sesquioxide were studied by TG-DTA and X-ray diffraction methods and by electron microscopy. Phase transitions of the polymorphs are influenced not only by the temperature before cooling and the cooling rate but also by the duration of melting. New commensurate and incommensurate superstructure phases, observed under the electron microscope, are described as the Naxa types, where N is various value between 2 and 2.48. Here a stands for the cell dimension of the δ form, the fluorite-type structure. The superstructures can be derived by a scheme for ordering oxygen vacancies in the defective fluorite-type structure.