[en] High-crystallinity poly(3-hexylthiophene) (P3HT) thin films were prepared by aging the precursor solutions, prepared using a good solvent, chloroform, at low temperatures prior to spin-casting. Lower solution temperatures significantly improved the molecular ordering in the spin-cast P3HT films and, therefore, the electrical properties of field-effect transistors prepared using these films. Solution cooling enhanced the electrical properties by shifting the P3HT configuration equilibrium away from random coils and toward more ordered aggregates. At room temperature, the P3HT molecules were completely solvated in chloroform and adopted a random coil conformation. Upon cooling, however, the chloroform poorly solvated the P3HT molecules, favoring the formation of ordered P3HT aggregates, which then yielded more highly crystalline molecular ordering in the P3HT thin films produced from the solution

[en] To compare the findings of early periventricular leukomalacia on MR imaging and on US. MR imaging was performed in 17 neonates in whom well-demarcated increased periventricular echogenicity was seen on sonography. One more patient was included during the same period because MR imaging of this patient showed a periventricular lesion not suspected on previous US. Initial sonography was performed within 6 days of birth and was followed up between one week and one month later. MR images were obtained within the first month of life. Twelve of 17 neonates showed abnormal periventricular signal intensities on MR imaging. Follow up sonography revealed cystic changes in two cases and heterogeneous hyperechogenicities in three. All patients except the two with cystic changes showed normal periventricular echogenicity on final sonography. On MR imaging, 11 cases showed multifocal periventricular increased signals on T1-weighted images, and two showed mainly decreased signals representing cysts. Positive findings were more evident on T1-weighted than on T2-weighted images. On T1-weighted imaging, the characteristic finding of early periventricular leukomalacia was multifocal periventricular hyper or hypointensities, and hyperintense lesions were more common than hypointense. In the diagnosis of early noncystic periventricular leukomalacia, MR imaging was more objective than US

[en] Early diagnosis of ruptured and unruptured tubal pregnancy became more accurate with the introduction of transvaginal sonographic equipment. The management principle of tubal pregnancy might be changed according to the sonographic findings. The purposes of this study were to define the sonographic findings of tubal pregnancy and to determine whether it is possible to differentiate the unruptured tubal pregnancies from the ruptured ones depending on the sonographic findings. The authors investigated the sonographic findings of the surgically confirmed 25 tubal pregnancy patients. There were 22(88%) unruptured and 3(12%) ruptured tubal pregnancies. Unruptured pregnancies showed tubal ring in 8, well defined hematosalpinx in 11, and poorly defined hematosalpinxin 2 patients. Ruptured pregnancies showed tubal sac with irregular margin in 2, and ill-defined hematosalpinx in one patient. In summary, well marginated tubal ring and hematosalpinx suggested unruptured tubal pregnancy, while tubal sac with irregular margin suggested ruptured pregnancy. However, it was difficult to differentiate the unruptured tubal pregnancy from the ruptured one when hematosalpinx was ill-defined

[en] Highlights: • The polymer blend-processed organic electronics is a facile rote to ensure chemical or environmental stability. • The blend FET performances were maintained at 76% or more under ethanol vapor. • The blend FETs showed a low range of μ_FET variation of ±10% over 100 min. We have introduced an efficient pen-printing method for solution-process fabrication of organic field-effect transistors (OFETs). Although polymer semiconductors used in this method are promising materials that provide electrical properties with mechanical flexibility, they have drawbacks such as poor long-term driving stability or dramatically decreased electrical performance under chemical environments. Herein we applied the spontaneous phase separation in blended polymers of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) and polystyrene (PS) as model semiconducting and protective polymers, respectively. A protective PS layer spontaneously formed on top of the PTAA layer, preventing direct exposure to chemical molecules and thus greatly improving long-term driving stability under ambient, high-humidity, and even ethanol vapor conditions. Even under the harshest ethanol vapor condition, the average field-effect mobility (μ_FET) of the PTAA + PS-blend FETs were maintained at 76% or more, and the threshold voltage showed only a small change of ±1.1 V over the range of vacuum, ambient, 75% humidity, and ethanol vapor conditions. Furthermore, μ_FETs of the PTAA + PS-blend FETs showed a low range of variation of about ±10% during 50 repeated measurements over 100 min under all conditions. The result suggests an efficient way forming a protective layer without an additional deposition step to secure the chemical and environmental stabilities of practical electronics.