High‐Performance Liquid Chromatographic Resolution of Neutral and Cationic Hetero[6]Helicenes

Cationic hetero[6]helicenes 1⁺ , 2⁺ and 3⁺ have been recently disclosed. Herein we report on their enantiomeric separation using high‐performance liquid chromatography. Separation of the antipodes can be achieved in preparative scale on neutral adducts with Chiralcel OD‐I or Chiralpak ID CSP. Selectivity factors of 1.90, 1.67, and 1.96 were obtained for 1-H , 2-H , and 3-H , respectively. Separation can also be performed on the carbenium ions on regular Chiralpak IA CSP using water‐containing eluents, thus allowing for enantiomeric purity determinations in aqueous environments. Resolution of neutral and cationic helicenes is also achieved on more recently developed LARIHC columns. The versatility of the cyclofructan phases allows for baseline separations for both cases and their loading capabilities are demonstrated. Finally, the configurational stability of 1⁺ , 2⁺ , and 3⁺ was measured. For each replacement of an oxygen atom by an amino group, the racemization barrier increases significantly (ΔG^? = 29.8, 36.3 and >37 kcal mol^‐1 for 1⁺ , 2⁺ , and 3⁺ respectively). Chirality 28:282–289, 2016. © 2016 Wiley Periodicals, Inc.     

The role of pigment based plumage traits in resolving conflicts

The role of melanin ‘badges of status’, in male–male competition has been well‐studied, in contrast, carotenoid based plumage has largely been examined in the context of female mate choice. Recent work has shown that carotenoid signals can also function in male–male competition, although the functions of the two types of signals is currently unclear. Here, we examine the relationships between colouration, dominance and aggression in the crimson finch Neochmia phaeton, a species where males have both conspicuous red carotenoid plumage and a black melanin patch. We examined the importance of carotenoid and melanin based signals in three contexts: 1) among free‐living birds interacting at a feeding station: we found that neither colour signal influenced the outcome of interactions; 2) in staged dyadic contest in captivity: we found that coloration from carotenoid pigments was positively related to the probability of winning a contest, while the size of the melanin plumage patch was not related to winning; and 3) in staged dyadic contests where male plumage colour had been masked: we found that the number of interactions required to determine dominance increased. While the underlying natural plumage colour was still important in these contests, birds with more intense carotenoid colouration were now more likely to lose. These results confirm carotenoid‐based signalling in male–male contests. However this signal is used in conjunction with other factors such as self‐assessment and body condition. Contrary to traditional expectations, the black melanin patch was not found to be important in this context.     

An ethanol extract of Ramulus mori improves blood circulation by inhibiting platelet aggregation

Inappropriate platelet aggregation can cause blood coagulation and thrombosis. In this study, the effect of an ethanol extract of Ramulus mori (ERM) on blood circulation was investigated. The antithrombotic activity of ERM on rat carotid arterial thrombosis was evaluated in vivo, and the effect of ERM on platelet aggregation and blood coagulation time was evaluated ex vivo. To evaluate the safety of ERM, its cytotoxicity to platelets and its effect on tail bleeding time were assessed; ERM was not toxic to rat platelets and did not prolong bleeding time. Moreover, administering ERM to rats had a significant preventive effect on carotid arterial thrombosis in vivo, and significantly inhibited adenosine diphosphate- and collagen-induced platelet aggregation ex vivo, whereas it did not prolong coagulation periods, such as prothrombin time and activated partial thromboplastin time. The results suggest that ERM is effective in improving blood circulation via antiplatelet activity rather than anticoagulation activity.     

Medium composition for effective slow freezing of embryonic cell lines derived from marine medaka (Oryzias dancena)

This study was conducted to identify optimal medium composition for freezing Oryzias dancena embryonic cell lines. Different freezing media consisting of various concentration of dimethyl sulfoxide (DMSO), fetal bovine serum (FBS), and trehalose were prepared and long-term cultured embryonic cell line was frozen in each freezing medium by conventional slow freezing program for 7 days. Through measurement of viability and growth of post-thaw cells frozen in each freezing medium, it was determined that optimal composition of three components was 10 % DMSO, 20 % FBS, and 0.1 M trehalose. The post-thaw cells frozen in optimal freezing medium showed similar morphology and growth rate with non-frozen cells. Next, this condition was applied to two different sets of experiment; (1) freezing of the same cells during expanded period (57 days) and (2) freezing of short-term cultured cells from other batches for 7 days. The viability of post-thaw cells was significantly low and comparable in set 1 and 2, respectively, when compared with the result of long term-cultured cells frozen in optimal freezing medium for 7 days and similar morphology and growth rate with non-frozen counterparts were detected in the post-thaw cells from both sets. In conclusion, this study first reports the optimal medium composition for freezing O. dancena embryonic cells, which can contribute to fish species preservation as well as improvement of cell-based biotechnology by providing stable cell storage.     

Changes of physiological rhythms of N-methyl-d-aspartate receptors in the chum salmon Oncorhynchus keta: effect of seawater acclimation during the parr-smolt transformation

We examined changes on N-methyl-d-aspartate receptors (NRs) in different growth stages (early parr, parr, and early smolt) of chum salmon, Oncorhynchus keta, during parr-smolt transformation from freshwater to seawater. Expression levels of NR genes mRNA and concentration of cortisol, T₃, T₄, dopamine and Na⁺/K⁺-ATPase activity significantly increased at salinity change condition. Moreover, in cultured brain cells, NRs were significantly lower in all groups treated with MK-801 (an antagonist of NRs) than in the early parr stage group in the FW treatment. We confirmed that the reduction in mRNA expression levels of NRs increased from the early parr to the early smolt stage. The information reported here should be taken into account in future studies on the relationship between memory factors of natal streams and homing mechanisms in Salmonidae.     

Differential daily rhythms of melatonin in the pineal gland and gut of goldfish Carassius auratus in response to light

The objectives of this study were to test the effects of light on melatonin rhythms in the pineal gland and gut of goldfish Carassius auratus and to investigate whether melatonin function differed in these two tissues, which are photosensitive and non-photosensitive respectively. Rhythms were evaluated by measuring arylalkylamine N-acetyltransferase (AANAT2) and melatonin receptor 1 (MT-R1) mRNA expression and melatonin concentration in the pineal gland, gut (in vivo), and cell cultures of the two tissues (in vitro). Compared to control, pineal gland melatonin secretion was higher at night, whereas the 24-h dark and ophthalmectomy groups maintained higher AANAT2 and MT-R1 mRNA expression during the day. Melatonin levels and AANAT2 and MT-R1 mRNA expression in the gut were also the highest at night, but the 24-h light, dark, and ophthalmectomy groups did not significantly differ from control. Furthermore, we measured AANAT2 and MT-R1 mRNA expression in high temperature water (30 °C) to investigate differences in the antioxidant capacity of pineal gland vs. gut melatonin. Melatonin and H₂O₂ levels, as well as AANAT2 and MT-R1 mRNA expression, were all higher in the two tissues under thermal stress, compared with their levels at 22 °C. Taken together, our results suggest that light has no effect on melatonin patterns in the gut, which appears to exhibit its own circadian rhythm, but both gut and pineal gland melatonin exhibit similar antioxidant function.     

Oxytocin and vasopressin in the rodent hippocampus

The role of the hippocampus in social memory and behavior is under intense investigation. Oxytocin (Oxt) and vasopressin (Avp) are two neuropeptides with many central actions related to social cognition. Oxt‐ and Avp‐expressing fibers are abundant in the hippocampus and receptors for both peptides are seen throughout the different subfields, suggesting that Oxt and Avp modulate hippocampal‐dependent processes. In this review, we first focus on the anatomical sources of Oxt and Avp input to the hippocampus and consider the distribution of their corresponding receptors in different hippocampal subfields and neuronal populations. We next discuss the behavioral outcomes related to social memory seen with perturbation of hippocampal Oxt and Avp signaling. Finally, we review Oxt and Avp modulatory mechanisms in the hippocampus that may underlie the behavioral roles for both peptides.     

An Ultra‐Mechanosensitive Visco‐Poroelastic Polymer Ion Pump for Continuous Self‐Powering Kinematic Triboelectric Nanogenerators

A mechanosensitive, visco‐poroelastic polymer ion pump that can rapidly establish a dense electrical double layer via mechanical pressure, thereby significantly enhancing output performance of an ionic triboelectric nanogenerator (iTENG), is described. A working mechanism of an iTENG using a highly mechanosensitive, visco‐poroelastic ion pump is suggested and the optimal characteristics of the polymer ion pump are reported by investigating optical, mechanical, electrical, and electrochemical properties. Surprisingly, the pressure sensitivity of the iTENG reaches 23.3 V kPa^?1, which is tens of times the record value. To achieve controlled high‐frequency pulses from an iTENG, kinematic systems using a gear train and a cam are integrated with a single grounded iTENG, which produces a maximum of 600 V and 22 mA (≈2.2 W cm^?2) at an input frequency of 1.67 Hz; after power transforming, those values are converted to 1.42 V and 225 mA. A capacitor of 1 mF can be fully charged to 2 V in only 60 s, making it possible to continuously operate a wireless‐communicating self‐powered humidity sensor. Also, due to the high transparency and deformability of the polymer ion pump, a self‐powered transparent tactile sensor is successfully assembled using a 5 × 5 iTENG array.