Poly(3-hexylthiophene) (P3HT) is used as a conjugated polymer material for the fabrication of organic solar cells. To enhance the performance of the solar cell, it is crucial to improve the charge transport properties of the out-of-plane direction, which corresponds to the direction normal to the cell. The out-of-plane hole mobility in P3HT films before and after rubbing was investigated. The mobility was measured by the time-offlight method and was enhanced by a factor of 8 with rubbing. The enhancement of mobility is significantly dependent on the regioregularity (RR) of P3HT and is the largest with low RR (91%). The mobility of low RR becomes almost equal to that of high RR (98%) after rubbing. Polarized absorption and Raman spectral measurements, and optical, atomic force, and scanning electron microscopy observations indicate the mobility enhancement can be attributed to aggregation and molecular planarity enhanced by rubbing. Three enhancement factors (EFs) for the mobility, aggregation, and planarity were quantified by changing the RR. It was thus determined that subtle aggregation produces a large mobility enhancement. According to the results of grazingincidence X-ray diffraction measurement, the increase of face-on component of P3HT by rubbing was observed and corresponds to the increase of π−π staking of thiophene ring along the out-of-plane direction. Evolution from the disordered to the ordered P3HT structure by rubbing significantly improves hole transport in the out-of-plane direction.

To determine the prevalence of indicator bacteria resistant to antimicrobials among poultry in three Southeast Asian countries (Vietnam, Indonesia and Thailand), we examined the antimicrobial susceptibilities of commensal bacteria isolated from chickens. In total, 125, 117 and 180 isolates of Escherichia coli, Enterococcus faecalis and Enterococcus faecium, respectively, were used to test for antimicrobial susceptibility. Bacterial resistance to antimicrobial treatment was most frequently observed with oxytetracycline with a prevalence of 73.6% (E. coli), 69.2% (E. faecalis) and 92.2% (E. faecium). Resistance to fluoroquinolones, which are critically important medicines, was also frequently observed in E. coli (48.8%), E. faecalis (17.9%) and E. faecium (82.8%). The prevalence of indicator bacteria resistant to most of the antimicrobials tested in these countries was higher than those for developed countries. The factors underlying antimicrobial resistance may include inappropriate and/or excessive use of antimicrobials. These results highlight the need for monitoring the emergence and prevalence of antimicrobial resistance in developing countries.

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