Synthesis of Nanohole‐Structured Single‐Crystalline Platinum Nanosheets Using Surfactant‐Liquid‐Crystals and their Electrochemical Characterization

Nanohole‐structured single‐crystalline Pt nanosheets have been synthesized by the borohydride reduction of Na₂PtCl₆ confined to the lyotropic liquid crystals (LLCs) of polyoxyethylene (20) sorbitan monooleate (Tween 80) with or without nonaethylene‐glycol (C₁₂EO₉). The Pt nanosheets of around 4–10 nm in central thickness and up to 500 nm or above in diameter have a number of hexagonal‐shaped nanoholes ∼1.8 nm wide. High‐resolution electron microscope images of the nanosheets showed atomic fringes with a spacing of 0.22 nm indicating that the nanosheets are crystallographically continuous through the nanoholed and non‐holed areas. The inner‐angle distributions for the hexagonal nanoholes indicate that the six sides of the nanoholes are walled with each two Pt (111), Pt (1 1) and Pt (010) planes. The formation mechanism of nanoholed Pt nanosheets is discussed on the basis of structural and compositional data for the resulting solids and their precursory LLCs, with the aid of similar nanohole growth observed for a Tween 80 free but oleic acid‐incorporated system. It is also demonstrated that the nanoholed Pt nanostructures loaded on carbon exhibit fairly high electrocatalytic activity for oxygen reduction reaction and a high performance as a cathode material for polymer‐electrolyte fuel cells, along with their extremely high thermostability revealed through the effect of electron‐irradiation.     

Microbial degradation of cyanobacterial cyclic peptides

Bacterial strain B-9 possesses hydrolytic enzymes capable of degrading microcystins (MCs) and nodularin that are toxic cyclic peptides produced by cyanobacteria. In the present study, the degradation activities of the cell extract of B-9 against non-toxic cyanobacterial cyclic peptides other than the MCs and nodularin were investigated, and the degradation products were analyzed by liquid chromatography/ion trap tandem mass spectrometry (LC/ITMS). It was confirmed that B-9 could also degrade these cyanobacterial cyclic peptides by hydrolysis of their peptide bonds. These results indicated that this bacterium possesses a very unique hydrolytic activity that can degrade structurally different cyclic peptides and that this may be effective for the detoxification of hazardous cyclic peptides.     

Dummy humanoid robot simulating several trunk postures and abdominal shapes – Report of element technologies

Development of clothing in consideration of the shape and body function of a person with spinal cord injury is an important task. Then, a dummy robot with a deformation mechanism was developed in this study for evaluating the comfortable level of clothings. Specifically, a trunk joint mechanism and an abdominal mechanism that can realize various deformations of the abdominal area and various trunk poses were developed. The trunk joint mechanism was implemented in order to simulate the seated posture of persons with spinal cord injury. The abdominal deformation mechanism was implemented using linear actuators and rotating servomotors in order to simulate abdominal obesity of persons with spinal cord injury. Further, a tactile sensor system was developed for measuring the clothing pressure on the abdominal area and evaluating the comfort or discomfort of clothing.     

Study of all-optical clock recovery performance by the primary and the secondary temporal Talbot effects in a second-order dispersive medium

We theoretically and experimentally study the all-optical clock recovery performance using the primary or the secondary temporal Talbot effects (PTTE or STTE, respectively) in a dispersive medium having the first-order dispersion together with the second-order dispersion (e.g., conventional single-mode fibers: SMFs). Our preliminary numerical simulations have indicated that the STTE-based all-optical clock recovery technique can improve double its performance as compared with the conventional PTTE-based technique when the second-order dispersion (dispersion slope) can be neglected. The following simulation results have revealed that the second-order dispersion, that the normal SMFs possess, limits the performance improvements in the STTE-based clock recovery, whereas the limited performance can be improved by appropriately compensating for the second-order dispersion. On the basis of our simulation results, experiments of the STTE-based clock recovery were conducted by compensating for the second-order dispersion of SMFs used as dispersive media. To be specific, SMFs’ second-order dispersion has been reduced to the one-sixteenth of its original value by combining with the reverse-dispersion fibers (RDFs) which can provide the second-order dispersion of the opposite sign to the SMFs. As a result, the performance improvements in the STTE-based clock recovery was demonstrated so that the 10-GHz clear optical clock pulses were successfully recovered from 10-Gbit/s return-to-zero (RZ) pseudo-random bit sequence (PRBS) optical signals.     

An improved EZ-GCD algorithm for multivariate polynomials

The EZ-GCD algorithm often has the bad-zero problem, which has a remarkable influence on polynomials with higher-degree terms. In this paper, by applying special ideals, the EZ-GCD algorithm for sparse polynomials is improved. This improved algorithm greatly reduces computational complexity because of the sparseness of polynomials. The author expects that the use of these ideals will be useful as a resolution for obtaining a GCD of sparse multivariate polynomials with higher-degree terms.     

Tracking control properties of human-robotic systems based on impedance control

Human-robotic systems that include interaction between human operators and robots should be designed with careful consideration for the dynamic property and control ability of a human operator. This paper performs manual tracking control tests on a human-robotic system using an impedance-controlled robot, and investigates control characteristics of a human operator according to the robot impedance properties. Experimental results demonstrate that humans try to maintain dynamic properties of an overall system as constant as possible by adjusting their own impedance properties. Then, a new training system using a neural network for operating a human-robotic system is constructed on the basis of the experimental findings in the human tracking control properties.     

Self-assembly of nano-sized arrays on highly oriented thin films of poly(tetrafluoroethylene)

Self-assembly of nano-sized arrays by casting a dilute solution of a guest material on the friction-transferred poly(tetrafluoroethylene) (FT-PTFE) substrate was newly discovered. Long axis of the rod-like structures forming the arrays is aligned perpendicular to the chain direction of FT-PTFE, and accordingly, the arrays are highly anisotropic. This phenomenon was observed for aqueous or organic solutions of polymers or organic materials. Each rod-like structure forming the arrays is composed of small grains. The arrays in question are formed regardless to the crystallinity of the guest materials. The formation mechanism of the nano-sized arrays is still unclear. However, we guess that they are formed as a result of microscopic flow pattern at the edge of the solution film. The arrays in question may be a new type of dissipative structure.     

m-Calpain (calcium-activated neutral proteinase) in Alzheimer''s disease brains

The possible association between the emergence of cytopathogenic HIV-1 variants and disturbance of the cytokine production in the course of HIV-1 infection was studied in 18 infected patients. The cytopathogenicity of the isolates was studied in a microassay based on the use of HIV-1-infectible Hela-CD4 cells carrying the bacterial LacZ gene under the control of the HIV-LTR (P4 cells). In addition, the production of cytokines by heparinized whole blood (HWB) obtained the same day from HIV-1(+) patients was measured. TNF-alpha was determined in a one-step procedure combining HWB culture in the presence of LPS+PHA for 24 h and detection of cytokines in the same wells. In separate experiments HWB was cultured in the presence of LPS+PHA for 48 h, then the supernatants were collected and stored until assayed by ELISa for IFN-gamma and IL-4. Higher TNF-alpha levels were found in activated HWB of patients with cytopathic strains (n = 9) than in patients with non-cytopathic strains (n = 9, p = 0.02) assessed with P4 cells. A defective production of type 1 cytokine (IFN-gamma) and no increased secretion of type 2 cytokines (IL-4) was observed in patients with cytopathic strains. IFN-gamma/IL-4 ratios were significantly lower in patients with cytopathic strains (n = 9) than in other patients (n = 9, p = 0.009). The results show that the disarray of cytokine production, as assessed with whole blood culture, is associated with the cytopathogenicity of HIV-1 isolates in HIV-1-infected individuals.     

Physiologic stress responses to laparoscopic cholecystectomy. A comparison of the gasless and pneumoperitoneal procedures

BACKGROUND: Differences in the physiological stress response to pneumoperitoneal (PP) and gasless abdominal wall-lifting (AWL) procedures used for laparoscopic cholecystectomy have not been properly evaluated. METHODS: We compared leukocyte count, interleukin-6 (IL-6) levels, arterial blood gases, creatinine clearance, plasma renin activity, cardiothoracic ratio, and clinical outcome in 27 patients without systemic complications who underwent laparoscopic cholecystectomy, including 11 by AWL and 16 by PP. RESULTS: Transient leukocytosis and high IL-6 levels were observed at POD 1 (postoperative day) in both groups, but both values returned to baseline by POD 2. IL-6 levels correlated significantly with operation time (p < 0.01). Changes in blood gases, creatinine clearance, plasma renin activity, and cardiothoracic ratio were not different for the two groups. The clinical outcome was similar for both groups. CONCLUSIONS: Our results indicate that both PP and AWL are appropriate for patients without serious complications.     

Relation between passive smoking at home and dietary intake

Recent attempts to protect hematopoietic progenitor cells from cytarabine (ara-C)-induced toxicity by transfer of the cytidine deaminase (CDD) gene resulted in efficient in vitro inducibility of ara-C resistance. Another enzyme involved in intracellular ara-CTP inactivation is the deoxycytidylate deaminase (dCMPD). We therefore transfected the human dCMPD cDNA gene into murine fibroblasts and investigated the relationship of forced dCMPD expression and resistance induction to ara-C. Several cell lines were established which demonstrated a 1.7-3.5-fold increase in cellular dCMPD activity and an up to 2-fold increase in the IC50 value of ara-C. However, increases in dCMPD activities did not show a positive linear correlation with the induction of ara-C resistance. In addition, CD34 + hematopoietic progenitor cells revealed the highest endogenous dCMPD enzyme levels among different human hematopoietic cells. Thus, despite the documented role for dCMPD in ara-CTP inactivation of certain cell types, these results suggest that the dCMPD gene may prove less useful than the CDD gene as a therapeutic target in attempts to attenuate ara-C-induced bone marrow toxicity.