We report unusual observations in the magnetic behavior of Sn 1−x 57 Fe x O 2−␦ powders prepared by a sol-gel method. Mössbauer spectra showed three different sites for those irons in the SnO 2 lattice. The samples seem to exhibit many sources of ferromagnetism, and the dominance of one of them greatly depends upon the synthesis conditions. In one sample, prepared using citric acid solution of metal Fe and annealed at 500°C for two hours, we observed magnetization, but its room temperature Mössbauer spectrum did not show any magnetic component, suggesting that the ferromagnetism could not have originated from the iron ions but from magnetic defects. In another sample prepared from chloride acid solution of Fe 2 O 3 and annealed at 600°C for six hours, a large magnetization and a sextet with broad lines were observed and the ferromagnetism was ascribed to iron impurities. In another sample prepared from citric acid solution of metal Fe but annealed at 650°C for two hours, we observed an intensive magnetic sextet with sharp lines but small magnetization, suggesting the presence of hematite doped with tin.

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The circulatory physiology of fetuses differs from that of neonates. The concept of biventricular combined cardiac output is necessary to understand and assess the fetal cardiac function. Fetal cardiac function has been estimated using echocardiographic methods such as M‐mode, B‐mode and pulsed wave Doppler. In addition, recent studies have reported the utility of tissue Doppler imaging in fetal echocardiography. However, parameters for fetal cardiac function remain to be established. Recently, we developed two novel techniques for assessing fetal cardiac function: an automatic fractional shortening method and E/e′ determination using the dual‐gate Doppler method. These two techniques are expected to be reliable and useful for assessing the fetal status in various pathological conditions.

Dilute magnetic semiconductors of Fe-doped SnO 2 and TiO 2 with the structure of rutile were prepared in forms of powder and thin films using the techniques of sol gel and pulsed-laser deposition. We present the results of measurement of vibrational density of states of Fe impurity dopants in these oxides and demonstrate the cases of dilution and clustering. The oxygen pressure during the film deposition was varied between 10 −1 and 10 −8 Torr. In TiO 2 films made at 10 −1 Torr, Fe is diluted, however, in films made at 10 −8 Torr Fe is clustered. The case of true Fe dilution in SnO 2 is also shown. In spite of larger mass defect for Fe in SnO 2 than that for Fe in TiO 2 the dilute Fe species probe the phonon states in SnO 2 more faithfully than in TiO 2. This result is understood in terms of the combined effect of mass defect and nearest-neighbor force-constant changes. The impurity modes are more pronounced in TiO 2 than in SnO 2 due to ca. 10% difference of the lattice cell volumes between these two rutile oxides.

Aim: The purpose of this study was to investigate the outcomes of fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS) in Japan. Methods: The retrospective cohort study (2012)(2013)(2014)(2015)(2016)(2017)(2018) was conducted in monochorionic twin pregnancies that underwent FLP for TTTS between 26 and 27 weeks from 2012 to 2018. The perioperative data, maternal complications, gestational age (GA) at delivery, neonatal complications, and survival of infants at 28 days of age were analyzed. At term-equivalent age, severe neurological complications were identified by imaging study. Results: Of 644 patients, 28 (4.3%) underwent FLP between 26 and 27 weeks, and 26 were analyzed. FLP procedures were technically successful in all cases. There were no cases of major maternal complications after surgery. Preterm rupture of membranes occurred in 34.6% of cases, and the mean GA at delivery was 33.2 AE 3.1 weeks. The survival of both twins was found in 23 (88.4%) cases, and the perinatal survival rate of at least one twin at 28 days of age was 100%. Severe neurological complications were found in six (12.2%) cases out of 49. Conclusions: FLP for TTTS between 26 and 27 weeks provided a good prognosis and caused no major maternal complications. However, severe neurological findings were found in 12% of infants.