Design improvement of the conversion mechanism from balloon inflation to bending motion for inflatable film actuators

Various soft actuators have been investigated to overcome the drawbacks of conventional solid machines and explore the applications of soft robotics. In particular, and because they are expected to be applicable in minimally invasive medicine because of their safety, soft inflatable microactuators using an actuation conversion mechanism from balloon inflation to bending motion have been proposed for high-output bending motion. These microactuators could be applied to create an operation space by safely moving organs and tissues; however, the conversion efficiency could be further improved. This study aimed to improve conversion efficiency by investigating the design of the conversion mechanism. The contact conditions between the inflated balloon and conversion film were examined to improve the contact area for force transmission, with the contact area dependent on the length of the contact arc between the balloon and force conversion mechanism and on the amount of balloon deformation. In addition, surface contact friction between the balloon and film, which affects actuator performance, was also investigated. The generated force of the improved device is 1.21 N at 80 kPa when it bends 10 mm, which is 2.2 times the generated force of the previous design. This improved soft inflatable microactuator is expected to assist in performing operations in a limited space, such as in endoscopic or laparoscopic operations.

Structure-activity relationship studies on an antitumor marine macrolide using aplyronine a-swinholide A hybrid

An aplyronine A-swinholide A hybrid, consisting of the macrolactone part of aplyronine A and the side chain part of swinholide A, was designed, synthesized, and biologically evaluated. This hybrid induced protein-protein interactions between two major cytoskeletal proteins actin and tubulin in the same manner as aplyronine A, and exhibited potent cytotoxicity and actin-depolymerizing activity. The importance of the methoxy group in the N,N,O-trimethylserine ester was clarified by the structure-activity relationship studies of the amino acid moiety by using the hybrid analogs. Furthermore, the comparison of the actin-depolymerizing activities between the side chain analogs of aplyronine A and swinholide A showed that the side chain analog of swinholide A had much weaker actin-depolymerizing activity than that of aplyronine A.

Synthesis of water-soluble anthracene-appended benzoxaboroles and evaluation of their cis-1,2-diol recognition properties

Three series of water-soluble anthracene-appended benzoxaboroles 1a-c were developed; their binding affinity toward cis-1,2-diols was explored by conventional fluorescence titrations to demonstrate the role of benzoxaborole as a general recognition motif of cis-1,2-diols for fluorescent probes. The complex structures of the tetra-coordinated boronate adducts between 1 and the cis-1,2-diols were revealed.

Pollinosis and all-cause mortality among middle-aged and elderly Japanese: a population-based cohort study

BACKGROUND

Having an allergic disease may have health implications beyond those more commonly associated with allergy given that previous epidemiological studies have suggested that both atopy and allergy are linked to mortality. More viable immune functioning among the elderly, as indicated by the presence of an allergic disease, might therefore be associated with differences in all-cause mortality.

OBJECTIVE

Using data from a Japanese cohort, this study examined whether having pollinosis (a form of allergic rhinitis) in a follow-up survey could predict all-cause and cause-specific mortality.

METHODS

Data came from the Komo-Ise cohort, which at its 1993 baseline recruited residents aged 40-69 years from two areas in Gunma prefecture, Japan. The current study used information on pollinosis that was obtained from the follow-up survey in 2000. Mortality and migration data were obtained throughout the follow-up period up to December 2008. Proportional hazard models were used to examine the relation between pollinosis and mortality.

RESULTS

At the 2000 follow-up survey, 12% (1088 of 8796) of respondents reported that they had pollinosis symptoms in the past 12 months. During the 76 186 person-years of follow-up, 748 died from all causes. Among these, there were 37 external, 208 cardiovascular, 74 respiratory, and 329 neoplasm deaths. After adjusting for potential confounders, pollinosis was associated with significantly lower all-cause [hazard ratio 0.57 (95% confidence interval = 0.38-0.87)] and neoplasms mortality [hazard ratio 0.48 (95% confidence interval = 0.26-0.92)].

CONCLUSIONS AND CLINICAL RELEVANCE

Having an allergic disease (pollinosis) at an older age may be indicative of more viable immune functioning and be protective against certain causes of death. Further research is needed to determine the possible mechanisms underlying the association between pollinosis and mortality.

Late enhancement of brain-behavior correlations during response inhibition

Previous neuroimaging studies of response inhibition have examined correlations between behavioral efficiency and brain activity, but the temporal stability of the correlations has largely been ignored. The present functional magnetic resonance imaging (fMRI) study demonstrates the temporal changes of the brain activity associated with performance efficiency that led to more robust brain-behavior correlations in a later part of the experimental sessions. Participants performed a stop-signal task requiring inhibition of inappropriate responses, where more efficient behavioral performance is reflected in a shorter stop-signal reaction time (SSRT). Among across-subject negative correlations between the brain activity and the SSRT, the majority of the negative correlations were observed in the second half of experimental sessions. In the cerebellar region that showed the greatest difference in correlations between the second and the first halves, the brain activity increased in efficient performers, whereas the brain activity decreased in poor performers. These results suggest the existence of multiple brain mechanisms that increase and decrease the brain activity depending on the behavioral efficiency of the performers. More practically, these results indicate that robust brain-behavior correlations can more effectively be detected in a later part of the experimental sessions.

Evaluation of genetic introgression from domesticated pigs into the Ryukyu wild boar population on Iriomote Island in Japan

We evaluated genetic introgression from domesticated pigs into the Ryukyu wild boar (RWB) population on Iriomote Island based on their genetic structure and diversity. We used a combination of mitochondrial DNA D-loop region (596 bp) polymorphisms and 23 microsatellite markers. RWBs (n = 130) were collected from 18 locations on Iriomote Island and compared with 66 reference samples of European and Asian domestic pigs. We identified six distinct haplotypes, involving 22 single nucleotide polymorphisms (including one insertion) in the RWB population. The phylogenetic tree had two branches: the RWB group and domestic lineage. Fourteen of 130 RWBs (10.8%) belonged to the European domestic lineage, including 11 RWBs from the Panari Islands, northwest of Iriomote Main Island (IMI). The heterozygosity values, total number of alleles, number of effective alleles and polymorphism information content of the RWB groups were lower than those of the European domestic groups. The RWB population on IMI had a lower heterozygous deficiency index (FIS = 0.059) than did the other populations, which indicates that this population was more inbred. There was a large genetic distance (FST = 0.560) between RWBs on IMI and the Meishan populations. Structure analysis using the 23 microsatellite markers revealed that 16 RWBs had an admixture pattern between RWB and domesticated pig breeds. These results suggest that gene flow may have occurred from domestic pigs to RWBs and demonstrate that there was low genetic variation in the IMI population.

Prevalence and risk factors of soil-transmitted helminth infection in Nepal

BACKGROUND

The purpose of this study is to evaluate the prevalence and intensity and examine the risk factors of soil transmitted helminth (STH; i.e., roundworm [Ascaris lumbricoides], hookworms [Ancylostoma duodenale and Necator americanus], and whipworm [Trichuris trichiura]) infections in Nepal.

METHODS

Five hundred and ninety-four adults (256 men and 338 women) were selected via convenience sampling from five communities in Nepal. The Kato-Katz method was used to assess the prevalence and intensity of STH infection in this population.

RESULTS

Prevalence of STH infection ranged from 3.3% in Birendranagar in Chitwan, 3.5% in Kuleshor in Kathmandu, 11.7% in Kanyam in Ilam, 17.0% in Dhikurpokhari in Kaski and 51.4% in Khokana in Lalitpur District [corrected]. Multivariable regression analysis revealed that not using soap for hand-washing was significantly associated with the prevalence and infection intensity of roundworm, hookworms and whipworm. Similarly, not wearing sandals or shoes outside was significantly associated with the prevalence and infection intensity of roundworm and hookworms, but not with infection intensity of whipworm. Literacy, being underweight or overweight, anemia and occupation were not associated with prevalence and intensity of roundworm and hookworms infection, but there was an association between occupation and the prevalence of whipworm infection.

CONCLUSION

STH infection was associated with individual hygiene behavior, but not with nutritional status or socio-demographic characteristics. Health policy focusing on changing individual hygiene behaviors might be useful in addressing STH infection in Nepal.

Transplantation tool integrated with MEMS manipulator for retinal pigment epithelium cell sheet

This paper reports a transplantation tool for the retinal pigment epithelium in an eye. We have developed MEMS manipulator as an end-effector for transplantation of retinal pigment epithelium cell sheet. Typical size of MEMS manipulator is 3mm×3mm. MEMS manipulator was made of polydimethylsiloxane and driven by pneumatic balloon actuators. MEMS manipulator have been improved and integrated with several functions by sensors and actuators. MEMS manipulator is integrated into a transplantation tool. A whole tool also requires improvements based on our experimental results. We have improved our tool in terms of assembling, sealing, and operation.