Preparation of poly(3-hexylthiophene)/[6,6]-phenyl-C61-butyric acid methyl ester Langmuir-Blodgett bulk hetero junctions on indium tin oxide.

Mono-layers of aggregated Poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) molecules were obtained by using solutions of P3HT, PCBM and P3HT-PCBM mixture without stabilizers such as stearates in chloroform at an air-water interface. 1 to 10 cycle-lifted LB films of P3HT and PCBM were successfully transferred to cleaned bare indium-tin-oxide coated glass substrate by vertical lifting method excluding the first 1 to 2 cycle layer. The dependence of P3HT and PCBM film thickness on the transfer cycles has been explained by the molecular sizes, where four edge-on P3HT molecular and six PCBM molecular stacking which result in thickness was taken into account. Work functions of deposited LB-layers were consistent with those of the ordinary casted films. P3HT and PCBM LB-layers showed optical activity in both infra-red (IR) and visible absorption regions of the spectrum. P-polarized IR absorption owing to C=C and C=O stretching vibrations observed in LB-layered films clearly indicate the enhancement of the orientation of these bonds perpendicular to the substrate surface in contrast to the spin-coated one. Visible optical absorption intensity was increased well in proportion with the lift cycle-numbers of both P3HT and PCBM LB films. The photovoltaic characteristics have been observed in the devices fabricated with P3HT (5 cycles-layer)/PCBM (5 cycles-layer) LB hetero structure as an active layer of the solar cells. The surface pressure of LB compression for the mixture of P3HT and PCBM, that is, bulk hetero mixtures, has also been well built up to 30 mN/m.

Soluble fullerene-based n-channel organic thin-film transistors printed by using a polydimethylsiloxane stamp.

A polydimethylsiloxane stamp was applied for the first time to the fabrication of n-channel thin-film transistors based on soluble small molecule organic semiconducting materials. The stamping method was found to facilitate film transfer onto a gate insulator surface irrespective of its surface free energy. We used [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) and C(60)-fused N-methylpyrrolidine-meta-dodecyl phenyl (C60MC12) as n-channel materials. The stamped thin-film transistors of C60MC12 achieved a high electron mobility of 0.39 cm(2)/(V s) and a current on-off ratio of 1 × 10(7). The mobility of the stamped C60MC12 thin-film transistors did not depend much on the surface free energy of the SiO(2) gate insulator with and without surface treatment using a silane-coupling reagent. In particular, the stamped C60MC12 thin-film transistor exhibited a relatively high mobility of 0.1 cm(2)/(V s) on a high energy surface of untreated SiO(2). In addition, a complementary inverter composed of an n-channel and a p-channel stamped thin-film transistor was demonstrated for the first time, which exhibits a maximum gain of 63 at a supply voltage of 50 V.

Hazard analysis of Listeria monocytogenes contaminations in processing of salted roe from walleye pollock (Theragra chalcogramma) in Hokkaido, Japan.

Hazard analysis of Listeria monocytogenes contamination during processing of salted walleye pollock (Theragra chalcogramma) roe was performed for a seafood plant in Japan from December 2005 to February 2006. As a result, L. monocytogenes number was detected on the pallet used for transport of barrels in the salting process and one of the rollers of the roller conveyor, which rotates while in contact with the bottoms of the barrels, but was not detected in any raw materials, interim products or final products. Thus, we believe that the pallet contamination initially occurred because of insufficient washing, that it was passed on to the bottoms of the barrels and that it was then passed on the roller of the roller conveyor by cross-contamination. Therefore, it is possible that interim and final products may become contaminated by processing devices and machinery. In addition, we conducted an inoculation study designed at the 1/20 actual factory scale using interim products with or without artificial color and seeded with L. monocytogenes to observe changes in its growth. In the inoculation study, multiplication of L. monocytogenes during the salting process was not confirmed in the samples with artificial color.

Severe optic neuropathy caused by dichloromethane inhalation.

PURPOSE: In this paper, we report a case of severe optic neuropathy caused by dichloromethane inhalation. CASE: A 65-year-old man fell unconsciousness while cleaning a dichloromethane tank containing a small amount of dichloromethane (purity greater than 99%) and was transported to the emergency department of our hospital, after which he was treated with hyperbaric oxygen therapy. After 1 month, narrowing of the visual field in both eyes was noted and the patient was referred to our department for additional examinations. Visual acuity was 0.3 in both eyes, which demonstrated normal reactions to light, while the critical flicker frequency (CFF) values were 30 and 25 Hz in the right and left eye, respectively. There were no abnormal findings shown in slit-lamp and fundus examinations, except for a mild cataract. Concentric contractions of the visual field by 10 degrees in both eyes were shown by a Goldmann perimetry examination, while an electroretinogram (ERG) and visual evoked cortical potential (VECP) examination exhibited nearly normal results. We diagnosed the condition as optic neuropathy caused by organic solvent poisoning, based on the decreased visual acuity, decreased CFF values, and visual-field narrowing. Although the patient was treated with vitamin B(12), visual disturbance, optic nerve atrophy, and results of VECP examinations worsened in both eyes, whereas ERG examination results were normal. CONCLUSIONS: Based on our findings, we considered that the central nervous system, including the optic nerve, was more severely damaged than the retina due to the normal findings in the ocular fundus and ERG examinations. Since dichloromethane produces carbon monoxide when catabolized in the liver, carbon monoxide toxicity together with the direct toxic effect of dichloromethane were considered to contribute to optic neuropathy in this case. The outcome for the present patient was poor.