Strain-induced creation and switching of anion vacancy layers in perovskite oxynitrides

Using strain to control oxynitride properties. 京都大学プレスリリース. 2020-12-01.原子空孔の配列を制御する新手法の発見. 京都大学プレスリリース. 2020-12-02.Perovskite oxides can host various anion-vacancy orders, which greatly change their properties, but the order pattern is still difficult to manipulate. Separately, lattice strain between thin film oxides and a substrate induces improved functions and novel states of matter, while little attention has been paid to changes in chemical composition. Here we combine these two aspects to achieve strain-induced creation and switching of anion-vacancy patterns in perovskite films. Epitaxial SrVO3 films are topochemically converted to anion-deficient oxynitrides by ammonia treatment, where the direction or periodicity of defect planes is altered depending on the substrate employed, unlike the known change in crystal orientation. First-principles calculations verified its biaxial strain effect. Like oxide heterostructures, the oxynitride has a superlattice of insulating and metallic blocks. Given the abundance of perovskite families, this study provides new opportunities to design superlattices by chemically modifying simple perovskite oxides with tunable anion-vacancy patterns through epitaxial lattice strain

向精神薬服用患者の突然死症例におけるカリウムイオンチャネルに関する分子生物学的解析：QT延長症候群関連遺伝子の多型が危険因子となり得るか？

Psychotropic drugs can pose the risk of acquired long QT syndrome (LQTS). Unexpected autopsy-negative sudden death in patients taking psychotropic drugs may be associated with prolonged QT intervals and life-threatening arrhythmias. We analyzed genes that encode for cardiac ion channels and potentially associated with LQTS, examining specifically the potassium channel genes KCNQ1 and KCNH2 in 10 cases of sudden death involving patients administered psychotropic medication in which autopsy findings identified no clear cause of death. We amplified and sequenced all exons of KCNQ1 and KCNH2, identifying G643S, missense polymorphism in KCNQ1, in 6 of the 10 cases. A study analysis indicated that only 11% of 381 healthy Japanese individuals carry this polymorphism. Reports of previous functional analyses indicate that the G643S polymorphism in the KCNQ1 potassium channel protein causes mild IKs channel dysfunction. Our present study suggests that administering psychotropic drug therapy to individuals carrying the G643S polymorphism may heighten the risk of prolonged QT intervals and life-threatening arrhythmias. Thus, screening for the G643S polymorphism before prescribing psychotropic drugs may help reduce the risk of unexpected sudden death2013博士（歯学）松本歯科大

Embryonic development and effect of water temperature on hatching of Lophius litulon

Most Lophiiformes including Lophius species are considered to spawn egg masses called an "egg veil" or "egg ribbon" composed of numerous mucoid chambers. However, Lophius eggs have been rarely collected in the field and thus little is known about their biological features. Here we examined the embryonic development of Lophius litulon and also the effects of water temperature on the embryonic development of eggs from egg veils collected in the field. Embryonic development was observed from the late cleavage stage to hatching. Low rates of mortality and deformity of embryos and early larvae were observed at 13-21 degrees C. The estimated appropriate water temperature range closely approximated the range of temperatures (12-20 degrees C) at which egg veils of L. litulon have been found in the field. Embryonic development accelerated with increased water temperatures. These results will enable estimation of the origin of and passive movement of egg veils and subsequently larvae and will help to reveal the spatiotemporal distribution of the spawning and nursery grounds of L. litulon

Coloration of a small Nozawa’s prickleback, Stichaeus nozawae Jordan and Snyder, 1902 (Zoarcoidei : Stichaeidae)

The coloration of small individuals of Nozawa’s prickleback, Stichaeus nozawae is presented for the first time, based on a specimen (112 mm SL) collected by T/S Ushio-maru from the Funka Bay, Hokkaido. The specimen has obscure bands on dorsal, anal, caudal and pectoral fins. Although specimens of comparable sizes (57.4-168 mm SL) have obscure bands on these fins, most larger specimens (252-361 mm SL) have no bands on the caudal and pectoral fins. Most descriptions or images in previous studies, including the original description, were based on large specimens (220-450 mm SL), which have no bands on these fins. Thus, bands on caudal and pectoral fins of S. nozawae tend to disappear with growt

Individual variations in fatty acid composition and concentration as indicators of the nutritional condition of wild pointhead flounder larvae

We investigated the fatty acid compositions and concentrations of wild marine fish larvae with a highly accurate method because our knowledge of them has been seriously limited compared with cultured larvae. This study presents estimates of the fatty-acid-based nutritional condition of individual larvae in the field. Because the pointhead flounder Cleisthenes pinetorum displays relatively high stock size fluctuations, we investigated the developmental change in the fatty acid compositions of the body trunk, head, and eye and the annual fluctuations in the fatty acid concentrations in the trunk. We show that the process of fatty acid accumulation is not uniform across body parts and that the trunk is a better indicator of larval nutritional status than other parts because there is less time lag. Starved larvae with simultaneously high docosahexaenomic acid ratios and low total fatty acid concentrations, as observed in laboratory experiments, are rare in the wild. Thus, starved larvae must be removed rapidly by predators before they can experience a relatively long period of starvation in the wild. Fatty acid accumulation was greater in the larvae of the 2005 year class than in those of the 2006 year class in their first feeding stage, according to the optimal model derived with generalized linear model. A previous study indicated that the 2005 year class showed stronger recruitment than the 2006 year class. We conclude that the fatty acid analysis of wild larvae is a useful index of their nutritional status and mortality, especially in the first feeding stage

Feeding habits of Pacific cod larvae and juveniles in Mutsu Bay, Japan

The diets and prey widths of Pacific cod (Gadus macrocephalus) larvae and juveniles were examined in Mutsu Bay. In early March, 11 yolk-sac larvae were caught in midwater of the bay mouth. Five of 11 larvae captured had not opened their mouths, and the remaining six had not fed. Post-larvae ≤ 7mm in total length (TL) fed on copepod nauplii, particularly Pseudocalanus nauplii. Prey items of post-larvae >7mm TL were chiefly crustacean eggs, and Pseudocalanus spp. copepodites and adults. From April to June, the main food organisms of cod juveniles were calanoid copepods, and changed from Pseudocalanus spp. to Calanus pacificus, Acartia clausi, and Centropages abdominalis. In addition, cod juveniles opportunistically fed on large-sized food organisms, namely, reptant megalopae, planktonic gastropods, and natant zoeae. In July, cod juveniles mainly fed on benthic prey items, such as gammarid amphipods and fish. It seems probable that these large-sized food organisms play an important role as alternative prey for cod juveniles when they change their main food from calanoid copepods to benthic prey items

Interannual growth differences and growth-selective survival in larvae and juveniles of marbled sole Pseudopleuronectes yokohamae

Flatfishes drastically change their habitat, body form, and feeding during metamorphosis; thus, the early juvenile and larval stages are viewed as being critical for early survival. However, to the best of our knowledge, no studies have tested the growth-mortality hypothesis for both larval and juvenile stages of flatfishes. Therefore, we investigated the relationship between growth rate and environmental factors and tested the hypothesis for both larval and juvenile stages of marbled sole Pseudopleuronectes yokohamae in Hakodate Bay, Japan from 2001 to 2003. For both larval and juvenile stages, otolith growth correlated with water temperature. Eye-migrating larvae were defined as survivors of planktonic life (SV pelagic). Large juveniles captured in late June and July were defined as survivors of shrimp predation (SVjuvenile). To test the growth-mortality hypothesis, otolith growth was compared between the SV and the original population. During the pelagic larval stage, growth-selective survival was not detected in any of the 3 yr. During the early juvenile stage, fast-growing individuals survived selectively in 2002 but not in 2003. In 2002, population growth of juveniles was slow because water temperatures were low. Thus, juveniles in 2002 required time to exceed the size spectrum that is vulnerable to shrimp predation; consequently, the individuals that grew more rapidly were able to survive selectively. Our results show the importance of the early juvenile stage for the survival of flatfishes

Comparisons of diet and nutritional conditions in Pseudopleuronectes herzensteini juveniles between two nursery grounds off northern Hokkaido, Japan

To characterise food-habit differences in Pseudopleuronectes herzensteini juveniles we compared diets, prey diversity and nutritional states between two groups, i.e., one in the Sea of Japan and the other in the Sea of Okhotsk around northern Hokkaido, Japan. Juveniles were collected with a sledge net along the sea bottom at depths of 8-50 m in August 2010 and 2011. In the Sea of Japan, 63 were analysed (23 in 2010 and 40 in 2011). In the Sea of Okhotsk, 88 were analysed (55 in 2010 and 33 in 2011). There were no differences in standard lengths of juveniles (the Sea of Japan: 27.0 mm in 2010 in median; 28.8 mm in 2011; the Sea of Okhotsk: 28.3 mm in 2010; 29.2 mm in 2011) or in bottom water temperatures at the study sites. However, stomach content volume and Fulton's condition factor K were higher in the Sea of Okhotsk than in the Sea of Japan. High feeding intensities in the Sea of Okhotsk may have led to a higher nutritional status in fish collected from this sea. In both seas, the diet comprised mainly harpacticoid copepods, gammarids and polychaetes, with some additional bivalves being observed in the Sea of Japan. The value of the prey-diversity index (Delta*) was lower when the K value of juveniles was higher