NaCl-dependent formation of the highly crystalline phase in sufficiently hydrated dimyristoylphosphatidylglycerol bilayers

We investigated the low-temperature phase behavior of dimyristoylphosphatidylglycerol (DMPG) bilayers in the presence of high concentration of NaCl (≥100 mM). Differential scanning calorimetry showed that the highly crystalline (HC) phase grew after an initial delay period when DMPG bilayers were sufficiently hydrated and incubated at 1˚C in the presence of more than 100 mM NaCl. The HC phase formation reached a plateau, the level of which depended on NaCl concentration; all the lipids were unable to be in the HC phase at the plateau stage without a quite high concentration of NaCl. Since electron microscopic observations suggested that the HC phase formed coexists with the precursor phases in a closed vesicle, elastic constrain and/or shortage of free sodium ions in the inside of the closed vesicle may prevent the complete transition into the HC phase

Superhydrophilicity on nano-rough carbon surfaces achieved by hyperthermal oxygen-atom beam exposure

In order to investigate a method to increase hydrophilicity on nano-rough carbon surfaces, a nano-rough surface of C(60) film and an atomically flat surface of highly oriented pyrolytic graphite (HOPG) were oxidized by hyperthermal oxygen-atom beam exposure and the hydrophilicities of the surfaces were investigated. Superhydrophilicity were achieved on these exposed carbon surfaces, which had low O/C ratio of approximately 28% and surface roughness (Ra) of approximately 3 nm. The direct oxidations on sp(2) bonded carbon atoms (basal plane) of these two carbon materials by the exposure of hyperthermal O-atom beam would contribute the superhydrophilicity

Identifying geographic areas at risk of rubella epidemics in Japan using seroepidemiological data

Objective Even with relatively high vaccination coverage, Japan experienced rubella epidemics in 2012-2014 and 2018-2019, which were fueled by untraced imported cases. We aimed to develop a risk map for rubella epidemics in Japan by geographic location via analysis of seroepidemiological data and accounting for the abundance of foreign visitors. Methods Geographic age distribution and seroprevalence were used to compute the age- and sex-dependent next-generation matrix in each region. We computed the probability of a major epidemic using the assumed number of untraced imported rubella cases proportionally modeled to the number of foreign travelers. Results Risks of a major epidemic were high in areas with capital cities, while areas with a greater fraction of older people yielded smaller effective reproduction numbers, a lower volume of foreign travelers, and thus a lower probability of a major epidemic. The volume of susceptible adult males was larger in urban geographic regions, having a greater number of foreign travelers than remote areas. Conclusions Our findings are consistent with the observation of multiple large clusters of rubella cases in urban areas during 2012-2014 and 2018-2019. Should a future rubella epidemic occur, it will likely be in geographic areas with capital cities

Frontal positions and mixed layer evolution in the Seasonal Ice Zone along 140°E in 2001/02

We describe the circulation and seasonal development of the upper ocean in the Seasonal Ice Zone (SIZ) of the Southern Ocean along 140°E. The 140°E section was repeated four times between November 2001 and March 2002, spanning the period from early spring to autumn. The sea ice edge was located at 62°-63°S in November, and retreated to 65°S in January. The circulation in the region is dominated by several fronts: the southern branch of Polar Front (PF-S) was located between 60° and 61.5°S; the northern branch of Southern ACC front (sACCf-N) was located at 61.5°-63°S, and roughly corresponds with the winter sea ice edge; and the southern branch of sACCf, the southern boundary of the ACC, and the Antarctic Slope Front (ASF) were closely spaced and found between 64°S and 65°S. Vigorous cyclonic (clockwise) eddies were identified in the region between the sACCf-N and sACCf-S throughout the period. Changes in salinity made the dominant contribution to changes in density in the SIZ, while changes in temperature made the largest contribution to density changes in the AZ, north of the sACCf. The depth of the mixed layer generally shoaled to the south, in all seasons. The decrease in mixed layer depth occurred in a series of steps. Seasonal variability in the depth of the mixed layer was strongest in the AZ, where summer warming formed a strong seasonal thermocline above the relatively deep (100 m) Winter Water layer. In the SIZ, the mixed layer became warmer, fresher and lighter in summer but the depth of the mixed layer remained at about 50 m throughout the year. The freshest surface waters were observed in the SIZ in January, immediately following the melt and retreat of the sea ice pack. An increase in mixed layer salinity from January to March likely reflects the effect of mixing with saltier waters below the mixed layer. Mixed layer depths south of the ASF were highly variable, both within and between seasons, varying from a minimum of ～20 m in January to over 500 m in March

Production of Insect Toxin Beauvericin From Entomopathogenic Fungi Cordyceps Militaris by Heterologous Expression of Global Regulator

Cordyceps militaris is one of entomopathogenic fungi species that is well known to be a traditional medicine in China for decades. Although the pharmaceutical and/or toxic properties of C. militaris has attracted attention as a promising resource for finding bioactive compounds, only a few substances including cordycepin have been reported so far. In the previous report heterologous expression of LaeA, a global regulator for secondary metabolites production in fungi, has been succeeded in C. militaris. The LaeA-engineered transformants are proved to produce new and/or elevated production of secondary metabolites, as detected by HPLC analysis. In order to further characterize the secondary metabolites that were being significantly produced by LaeA transformant, HPLC profiling and structure elucidation by proton NMR were conducted in two target compounds, designated as compound 1 and compound 2. Compound 1 possessed the highly similar characters to insect toxin beauvericin in UV spectrum, molecular weight, and retention time in HPLC analysis. Proton NMR analysis revealed that compound 1 had the same proton signals as beauvericin