The use of free rectus abdominis myocutaneous flap to close the empyema space with alveolar fistula--a case report

A 59-year-old man, who had had right middle and lower lobectomy for pulmonary tuberculosis, admitted for the treatment of empyema with fistula. Closure of empyema space with free rectus abdominis myocutaneous flap was performed following open window thoracotomy and thoracoplasty. As he previously underwent two major operation, lobectomy by posterolateral approach and gastrectomy for gastric ulcer, free rectus abdominis flap was chosen instead of omental flap or latissimus dorsi myocutaneous flap. Postoperative CT film showed that this flap was filled up in all interstices of the empyema cavity. The pedicle vessels to this flap are large enough to provide long stalks, so microsurgical anastomosis can be accomplished safely. The use of free rectus abdominis myocutaneous flap is one of a useful maneuver for chronic empyema with fistula.     

Development of anthropomorphic multi-D.O.F. master-slave arm for mutual telexistence

We developed a robotic arm for a master-slave system to support "mutual telexistence", which realizes remote dexterous manipulation tasks and close physical communication with other people using gestures. In this paper, we describe the specifications of the experimental setup of the master-slave arm to demonstrate the feasibility of the mutual telexistence concept. We developed the master arm of a telexistence robot for interpersonal communication. The last degree of the 7-degree-of-freedom slave arm is resolved by placing a small orientation sensor on the operator's arm. This master arm is made light and impedance control is applied in order to grant the operator as much freedom of movement as possible. For this development stage, we compared three control methods and confirmed that the impedance control method is the most appropriate to this system.     

Effect of a hepatocyte growth factor/heparin-immobilized collagen system on albumin synthesis and spheroid formation by hepatocytes

A hepatocyte growth factor (HGF)/heparin-immobilized collagen system was used as a synthetic extracellular matrix for hepatocyte culture. The albumin synthesis, nucleus numbers and morphology of the hepatocytes were determined separately to evaluate the hepatocyte number and hepatocyte-specific function under this system. The benefits of the HGF/heparin-immobilized collagen system for hepatocyte culture were confirmed by three types of culture methods in vitro, namely 2D film cultures, 2D gel cultures and 3D gel cultures. In 2D collagen film cultures, hepatocytes exhibited the highest albumin synthesis (1.42 μg/well/day) in HGF/heparin-immobilized collagen films at 7 days of culture. Heparin inhibited hepatocyte adhesion while HGF promoted hepatocyte migration, and spheroid formation was easily detected in HGF/heparin-immobilized collagen films. In 2D collagen gel cultures, albumin synthesis of around 15 μg/well/day was detected and maintained for more than 18 days on HGF/heparin-immobilized collagen gels. Similar findings were obtained in 3D HGF/heparin-immobilized collagen gel cultures, which exhibited albumin synthesis of up to 30 μg/well/day. The albumin synthesis by hepatocytes was two-fold higher in 3D gel cultures compared with 2D gel cultures, and was maintained for over 2 weeks compared with 2D film cultures using the HGF/heparin-immobilized collagen system. Taken together, the HGF/heparin-immobilized collagen system was effective for albumin synthesis by hepatocytes in both 2D film cultures and 3D gel cultures, and therefore shows good potential for tissue engineering use.     

Dual Partial Dye Doping for Chromaticity Tuning and Performance Enhancement of White OLEDs

In general, a guest dopant is doped into a single host matrix for white-light emission with two complementary colors. In this work, however, we have fabricated a white organic light-emitting diode (WOLED) based on dual partial dye doping in which a guest dopant is partially doped into two different host emitters; namely, orange-red emitting 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminos-tyryl)-4H-pyran (DCM) is partially doped into both blue-emitting 4, 4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi) and green-emitting Tris-(8-hydroxyquinoline) aluminum (Alq₃). We demonstrate that dual partial dye doping allows us to finely tune the Commission Internationale d'Eclairage (CIE) chromaticity coordinates to the equienergy white point (x = 0.33, y = 0.33). In addition, it enhances device performance further, compared to WOLEDs based on DCM partially doped into a single host matrix (either DPVBi or Alq₃). Moreover, the dual partial doping scheme is shown to provide a way of suppressing the self-quenching effect (singlet-singlet annihilation). For a systematic study, we have implemented a comprehensive numerical model and performed simulations of the OLED structure, providing a clear understanding with regard to the underlying physics of OLEDs. We also carry out an investigation of the effects of key design parameters such as the doped layer position and thickness and dye.     

Development of index of social activities for the elderly

In order to develop indices of social activities for the elderly, two surveys with 2 year intervals were conducted on the same 5,201 elderly subjects in four areas in Japan using a self-administered questionnaire. Social activities were defined as "activities which required contact with society" and were measured by 4 major facets of social activities, which were based on 21 questions relating to job activity, socially-plated activities, learning activities, and personal activities. The results were as follows; 1. The Wilcoxon scores in indices for 4 facets were given in sex and age groups. 2. Means of scores of indices increased with the degree of social activities from a subjective judgment. 3. Rank correlation coefficients between indices in two surveys were 0.60-0.71 for the persons whose answers were "no" to the question "did degrees of your activities change over the two years?" 4. Differences between indices in two surveys were higher in the persons with answers of "increase" to the above question than those with answers of "no", and were lower in those with answers of "decrease". These findings suggest that indices are available for assessing social activities as indicated by the reproducibility, validity and responsiveness found in this study.     

Evolution of a phosphorothioate RNA library during in vitro selection

We carried out an in vitro selection of aptamers from an RNA library with phosphorothioate linkages instead of normal phosphodiesters. This "thio-RNA" library had smaller dissociation rate constant (kd) to a target protein than a natural RNA library. On the basis of the results, an improved selection procedure to obtain ideal nucleic acid drugs will be discussed.     

Improvement of corrosion resistance of magnesium metal by rare earth elements

Mg metal containing rare earth metals (REs) can be electrowon directly by molten salt electrolysis. The clarification of the optimum RE content in Mg is necessary to fix the electrolytic conditions in the direct electrowinning of Mg with RE. From this point of view, effect of RE addition in Mg metal on its corrosion property was studied in detail in this study. The specimen was prepared by adding La, Nd, or Ce in melted Mg metal, and its corrosion resistance was examined by an immersion test in 3 mass%-NaCl solution at room temperature. The corrosion resistance of Mg was improved greatly by adding a small amount of RE, whereas the excess addition of RE deteriorated the corrosion resistance. The optimum RE content was about 0.5 mass%. In this study, the corrosion property of Mg with an artificial surface oxide layer was also studied to clarify the effect of surface oxide. The corrosion resistance of Mg was particularly strengthened by conversion coating in a solution including La(NO₃)₃, Nd(NO₃)₃, or Ce(NO₃)₃, with Mg(NO₃)₂. This result suggests that the surface oxide film consisting of both Mg and RE gives ideal corrosion resistance to Mg metal. Mg metal with conversion coating including RE should also be of use as a corrosion-resistant material.