High‐Capacity All‐Solid‐State Sodium Metal Battery with Hybrid Polymer Electrolytes

All‐solid‐state sodium metal batteries (SSMBs) are of great interest for their high theoretical capacity, nonflammability, and relatively low cost owing partially to the abundance of sodium recourses. However, it is challenging to fabricate SSMBs because compared with their counterparts, which contain lithium metal, sodium metal is mechanically softer and more reactive toward the electrolyte. Herein, the synthesis and electrochemical properties of newly designed sodium‐containing hybrid network solid polymer electrolytes (SPEs) and their application in SSMBs are reported. The hybrid network is synthesized by controlled crosslinking of octakis(3‐glycidyloxypropyldimethylsiloxy)octasilsesquioxane and amine‐terminated polyethylene glycol in existence with sodium perchlorate (NaClO₄). Plating and stripping experiments using symmetric cells show prolonged cycle life of the SPEs, >5150 and 3550 h at current density of 0.1 and 0.5 mA cm^?2, respectively. The results for the first time show that the SPE|sodium metal interface migrates into the SPE phase upon cycling. SSMBs fabricated with the hybrid SPE sandwiched between sodium metal anode and bilayered δ‐Na_xV₂O₅ cathode exhibit record‐high specific capacity for solid sodium‐ion batteries of 305 mAh g^?1 and excellent Coulombic efficiency. This work demonstrates that the hybrid network SPEs are promising for SSMB applications.     

Stress activation of Bacillus subtilis sigma B can occur in the absence of the sigma B negative regulator RsbX.

Environmental stress activates sigma B, the general stress response sigma factor of Bacillus subtilis, by a pathway that is negatively controlled by the RsbX protein. To determine whether stress activation of sigma B occurs by a direct effect of stress on RsbX, we constructed B. subtilis strains which synthesized various amounts of RsbX or lacked RsbX entirely and subjected these strains to ethanol stress. Based on the induction of a sigma B-dependent promoter, stress activation of sigma B can occur in the absence of RsbX. Higher levels of RsbX failed to detectably influence stress induction, but reduced levels of RsbX resulted in greater and longer-lived sigma B activation. The data suggest that RsbX is not a direct participant in the sigma B stress induction process but rather serves as a device to limit the magnitude of the stress response.     

Very high frequency electron paramagnetic resonance of 2,2,6,6-tetramethyl-1-piperidinyloxy in 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine liposomes: partitioning and molecular dynamics.

Partitioning and molecular dynamics of 2,2,6,6,-tetramethylpiperedine-1-oxyl (TEMPO) nitroxide radicals in large unilamellar liposomes (LUV) composed from 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine were investigated by using very high frequency electron paramagnetic resonance (EPR) spectroscopy. Experiments carried out at a microwave frequency of 94.3 GHz completely resolved the TEMPO EPR spectrum in the aqueous and hydrocarbon phases. An accurate computer simulation method combined with Levenberg-Marquardt optimization was used to analyze the TEMPO EPR spectra in both phases. Spectral parameters extracted from the simulations gave the actual partitioning of the TEMPO probe between the LUV hydrocarbon and aqueous phases and allowed analysis of picosecond rotational dynamics of the probe in the LUV hydrocarbon phase. In very high frequency EPR experiments, phase transitions in the LUV-TEMPO system were observed as sharp changes in both partitioning and rotational correlation times of the TEMPO probe. The phase transition temperatures (40.5 +/- 0.2 and 32.7 +/- 0.5 degrees C) are in agreement with previously reported differential scanning microcalorimetry data. Spectral line widths were analyzed by using existing theoretical expressions for motionally narrowed nitroxide spectra. It was found that the motion of the small, nearly spherical, TEMPO probe can be well described by anisotropic Brownian diffusion in isotropic media and is not restricted by the much larger hydrocarbon chains existing in ripple structure (P beta') or fluid bilayer structure (L alpha) phases.     

5′-Regulatory region of Agrobacterium tumefaciens T-DNA gene 6b directs organ-specific,wound-inducible and auxin-inducible expression in transgenic tobacco

The regulatory activity of a 826 bp DNA fragment located upstream of the pTiBo542 TL-DNA gene 6b coding region was analysed in transgenic tobacco, using -glucuronidase (gus) as a reporter gene. The region was shown to drive organ-specific, wound- and auxin-inducible expression of the reporter, the effect being dependent on the type and concentration of auxin.     

Algae polysaccharides. 55. Polysaccharide composition of some brown Kamchatka algae]

A new spectrophotometric procedure was developed for the quantitative determination of fucoidan and alginic acid and used for their analysis in extracts from biomass of 17 species of brown algae collected in coastal waters of the Kamchatka peninsula. In addition, neutral monosaccharides and mannitol were determined in the hydrolysis products of the alga biomass samples. The polysaccharide composition was shown to substantially depend on the algal species. The alginic acid content was maximal in the Alaria marginata blades; all the other representatives of the order Laminariales are also useful sources of the polysaccharides. At the same time, the fucoidan content is rather low in Laminariales. The highest content of fucoidan was found in Saundersella simplex, but Chordaria flagelliformis and Fucus evanescens are more practical fucoidan sources; the available supplies and the sugar composition make the latter alga the most suitable for the complex processing to prepare mannitol, fucoidan, and alginic acid.     

Development of Species Preferences in Two Hamsters, Phodopus campbelli and Phodopus sungorus: Effects of Cross-Fostering

Experiments were conducted to investigate species-specific preferences in two closely related species of hamsters, Phodopus campbelli and Phodopus sungorus . Male hamsters that were raised with conspecifics spent more time investigating an anaesthetized conspecific male than a heterospecific male, and also spent more time investigating odours of conspecifics than those of heterospecifics (midventral gland, urine, and saccular secretion). Cross-fostered P. sungorus males reversed their normal preferences, spending more time investigating stimuli (anaesthetized males and all three odours) of the foster species. Cross-fostered P. campbelli males also investigated an anaesthetized male of the foster species more than a male of their own species, but did not show a preference for odours alone. Social experience during the 15 d immediately following weaning also influenced these preferences. If exposures during and after nesting were to heterospecifics the preference for heterospecifics was strengthened; if either period of experience was with a conspecific, this eliminated the preference for heterospecifics in P. sungorus but did not influence the lack of a preference in P. campbelli . Thus, early experience during both the nestling stage and the 15 d after weaning influenced responses to species-typical cues in both species, but it had a more pronounced effect in P. sungorus .     

Stimulation of eryptosis by anti-A IgG antibodies.

Anti-A IgG antibodies have previously been shown to stimulate Ca(2+) entry into red blood cells. Increased cytosolic free Ca(2+) concentration is known to trigger eryptosis, i.e. suicidal erythrocyte death, characterized by exposure of phosphatidylserine at the erythrocyte surface. As macrophages are equipped with phosphatidylserine receptors, they bind, engulf and degrade phosphatidylserine exposing cells. The present experiments have been performed to explore whether anti-A IgGs trigger phosphatidylserine exposure of erythrocytes. Phosphatidylserine exposure was estimated from annexin-V binding as determined in FACS analysis. Exposure to anti-A IgGs (0.5 microg/ml) indeed significantly increased annexin-V binding in erythrocytes with blood group A, but not in erythrocytes with blood group 0. According to Fluo3 fluorescence, anti-A IgGs increased cytosolic Ca(2+) concentration. Whole cell patch clamp recordings revealed the activation of a Ca(2+)-permeable cation channel following treatment with anti-A-IgGs. Annexin-V binding following anti-A IgG exposure was blunted by Ca(2+) removal while anti-A IgG-stimulated cation channel activity was not dependent on extracellular Ca(2+). Osmotic shock (exposure of erythrocytes to 850 mOsm) increased annexin binding, an effect further enhanced by exposure to anti-A IgGs. In conclusion, anti-A IgGs activate erythrocyte cation channels leading to Ca(2+) entry and subsequent erythrocyte cell membrane scrambling. The effect most likely contributes to the elimination of erythrocytes following an immune reaction against the A antigen.     

Stimulation of suicidal erythrocyte death by lipoxygenase inhibitor Bay-Y5884.

The prostaglandin PGE(2), a metabolite of the cyclooxygenase pathway, activates Ca(2+)-permeable cation channels in erythrocyte cell membranes leading to entry of Ca(2+) with subsequent eryptosis, i.e. cell shrinkage, breakdown of phosphatidylserine (PS) asymmetry and membrane blebbing, all features typical for apoptosis in nucleated cells. PS exposing cells are recognized by macrophages, engulfed, degraded and thus cleared from circulating blood. The present study explored whether the specific lipoxygenase inhibitor Bay-Y5884 influences eryptosis. As determined by competitive ELISA, Bay-Y5884 (20 microM) enhanced the release of PGE(2) from human erythrocytes. According to whole-cell patch-clamp, Bay-Y5884 (20 microM) activated nonselective cation channels. The effect of Bay-Y5884 on cation channels was abolished by the cyclooxygenase inhibitor diclophenac (10 microM). Bay-Y5884 (30-40 microM) significantly increased erythrocyte free Ca(2+) concentration and PS exposure as analyzed in flow cytometry by Fluo3 fluorescence and annexin-V binding, respectively. PS exposure triggered by 20 microM (but not by 40 microM) Bay-Y5884 was blunted by cyclooxygenase inhibitors acetylsalicylic acid (50 microM) and diclophenac (10 microM). In conclusion, the lipoxygenase inhibitor Bay-Y5884 enhances erythrocyte PGE(2) formation with subsequent activation of non-selective cation channels, Ca(2+) entry and phospholipid scrambling.     

Aspects of reproductive biology of wild-caught polar cod (<Emphasis Type="Italic">Boreogadus saida</Emphasis>) from Svalbard waters

Polar cod (Boreogadus saida) is considered a key species in the Arctic marine ecosystems. Yet detailed or even basic knowledge regarding its biology and adaptations, especially during the polar night, is in many cases poor. Data are presently unavailable in Western literature on the gonad development of polar cod and its reproductive biology in wild specimens. Accordingly, gonad development of wild-caught polar cod from fjords of the Svalbard archipelago was studied across seasons (April, August, September, November and January). Histological analyses of polar cod showed strong indication of a group-synchronous oocyte development with determinate fecundity and iteroparity. Females started gonadal development prior to April and had not yet reached the final stage of maturation in January. Testes matured more rapidly, with males ready to spawn in January. Furthermore, our data show that polar cod were able to reach sexual maturity at age 1+. Based on our data and previous reports, we hypothesise that polar cod is a total spawner.