Enantioseparation of isoxanthohumol in beer by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography

Chiral resolution of isoxanthohumol (IX) in beer samples was performed by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography. The optimum running conditions were found to be 20 mM phosphate buffer (pH 7.0) containing 45 mM hydroxypropyl-gamma-cyclodextrin and 100 mM sodium dodecyl sulfate with an effective voltage of +20 kV at 20 degrees C using direct detection at 210, 295, and 370 nm. IX was detected in 12 beer samples and the total levels of (+)- and (-)-IX ranged from 0.15 to 1.4 mg/L. But the amount of xanthohumol (XN) was below the detection limit (0.017 mg/L). Each level of (-)-IX was almost the same as that of (+)-IX, suggesting that IX was a racemic mixture in these beer samples. The racemization of IX in beer could be attributed to the production of a racemic mixture from XN during boiling and to the fact that IX enantiomers were easily interconverted.     

Prognostic Value of Left Atrial Function in Dogs with Chronic Mitral Valvular Heart Disease

Background

A strong correlation between left atrial (LA) dysfunction and the severity of cardiac disease has been described in human patients with various cardiac diseases. The role of LA dysfunction in dogs with chronic mitral valvular heart disease (CMVHD) has not been addressed.

Objectives

To investigate the correlation between LA function and the prognosis of dogs with CMVHD.

Animals

Thirty‐eight client‐owned dogs with CMVHD.

Methods

Prospective clinical cohort study. Dogs were divided into 2 groups (survivors and nonsurvivors) based on the onset of cardiac‐related death within 1 year. Physical examination and echocardiographic variables were compared between the groups. For the assessment of the comparative accuracy in identifying patients with cardiac‐related death, receiver operating characteristic (ROC) curves and multivariate logistic analysis were used.

Results

The highest accuracy was obtained for the LA active fractional area change (LA‐FAC _act), with an area under the ROC curve (AUC) of 0.95, followed by the left atrial to aortic root ratio (LA/Ao), with an AUC of 0.94; peak early diastolic mitral inflow velocity (E), with an AUC of 0.85; and LA total fractional area change (LA‐FAC _total), with an AUC of 0.85. In the multivariate logistic regression analysis, LA‐FAC _act emerged as the only independent correlate of cardiac‐related death within 1 year (odds ratio = 1.401, P = .002).

Conclusions and Clinical Importance

Regarding both the size and function, the LA has a strong correlation with the prognosis of dogs with CMVHD. The most significant independent predictor of mortality in this study was LA‐FAC _act.     

Does future climate change facilitate expansion of evergreen broad-leaved tree species in the human-disturbed landscape of the Korean Peninsula? Implication for monitoring design of the impact assessment

To quantitatively assess future change of evergreen broad-leaved tree species’ distributions in human-disturbed landscapes of the Korean Peninsula under climate change, potential habitats (PHs) were projected for four important evergreen broad-leaved tree species (Quercus acuta, Castanopsis sieboldii, Machilus thunbergii, and Neolitsea sericea) by species distribution models (SDMs). The distribution data (presence/absence) of the target species in Korea and Japan were used as response variables for SDMs, and climatic data were used as explanatory variables. Three general circulation models under A2 emission scenarios were used as future climate scenarios for the years 2070–2099. Potential habitats masked by land-use data (PHLUs) were projected to assess the impact of anthropogenic activities. Highly accurate SDMs were obtained for all the target species. The current PHs were decreased to 21–35 % by the anthropogenic activities. Future PHLUs for all the target species were projected to increase by 2.0–18.5 times of current PHLUs. These results suggest that all the target species are applicable as indicator species for monitoring in the Korean Peninsula, even if anthropogenic effects are incorporated. Variation of the increasing rate was caused by the differences in the response to temperature changes. M. thunbergii responded sensitively to the increase of minimum temperature of coldest month and had a largest increase in PHLUs under future climate. Therefore, M. thunbergii is considered to be most appropriate species for monitoring the changes of horizontal distributions above all focal evergreen broad-leaved tree species.     

Effects of low pH on the reproductive behavior of salmonid fishes

In northern Europe and America, the acidification of lakes and rivers induced by acid precipitation has damaged fish populations. At present, rapidly expanding industrial activities in East Asia have led to continuous increases in the quantity of emission of acidic pollutants, and rain of acidic levels of pH4 has precipitated throughout Japan. In this way, the effects of acid rain on fish populations have also been manifested in Japan. In order to examine the effects of low pH on the reproductive behavior of salmonids which are known to be acid-sensitive species, changes in the frequency of upstream behavior and spawning-related female nest-digging behavior in response to changes in pH were observed in mature hime salmon (land-locked sockeye salmon) Oncorhynchus nerka, brown trout Salmo trutta and Japanese char Salvelinus leucomaenis. Digging and upstream behavior were significantly inhibited in weakly acidic water of pH 5.8–6.4 formulated using sulfuric acid. Land-locked sockeye salmon was the most sensitive to changes in pH among the three species.     

Moisture distribution in rice grains used for sake brewing analyzed by magnetic resonance imaging

Water absorption in individual white-core and non-white-core grains of rice varieties used in sake brewing was observed during soaking by magnetic resonance imaging (MRI). Water was absorbed faster in white-core grains than in non-white-core grains and was pooled in the core. Moisture distributions were compared using the line profiles of nuclear magnetic resonance signal intensities (SI profiles) generated from magnetic resonance images of grains soaked for 2 h. SI profiles of white-core and non-white-core grains overlapped despite slight differences in the central and intermediate regions of the grains. A white-core-like structure with loosely packed starch granules was found to exist in the endosperm of non-white-core grains. SI profiles of grains polished to 70% of the yield weight of brown rice were similar in shape to those of grains polished to 90% of the yield, but their overall moisture content was higher after the removal of the hydrophobic grain periphery. A varietal difference in the thickness of the intermediate region, which may affect fissuring resistance in the polishing process, was detected in SI profiles. Differences in water absorbability between parents and their offspring were also apparent from their SI profiles. MRI enabled the detection of variety-specific water-absorption properties in grains.     

Repeated and sudden reversals of the dipole field generated by a spherical dynamo action

Using long-duration, three-dimensional magnetohydrodynamic simulation, we found that the magnetic dipole field generated by a dynamo action in a rotating spherical shell repeatedly reverses its polarity at irregular intervals (that is, punctuated reversal). Although the total convection energy and magnetic energy alternate between a high-energy state and a low-energy state, the dipole polarity can reverse only at high-energy states where the north-south symmetry of the convection pattern is broken and the columnar vortex structure becomes vulnerable. Another attractive finding is that the quadrupole mode grows, exceeding the dipole mode before the reversal; this may help to explain how Earth's magnetic field reverses.     

First report of sclerotinia rot of mango caused by <Emphasis Type="Italic">Sclerotinia sclerotiorum</Emphasis> in Japan

A panicle blight with sclerotia was found on mango (Mangifera indica L.) in Okinawa Prefecture, Japan, in March 2016. Water-soaked lesions with white mycelia developed on panicles in the flowering stage; softening and decay of panicles was followed by formation of sclerotia. The fungus isolated from these sclerotia was identified as Sclerotinia sclerotiorum based on morphology and analysis of rDNA-ITS sequences. The isolate reproduced the symptoms on mango panicles in an inoculation test and was reisolated from flower stalks. This is the first report of sclerotinia rot (kinkaku-byo in Japanese) on mango caused by S. sclerotiorum in Japan.