486 research outputs found
BCS-BEC crossover at finite temperature in spin-orbit coupled Fermi gases
By adopting a -matrix-based method within the approximation for the
pair susceptibility, we study the effects of the pairing fluctuation on the
three-dimensional spin-orbit coupled Fermi gases at finite temperature. The
critical temperatures of the superfluid/normal phase transition are determined
for three different types of spin-orbit coupling (SOC): (1) the extreme oblate
(EO) or Rashba SOC, (2) the extreme prolate (EP) or equal Rashba-Dresselhaus
SOC, and (3) the spherical (S) SOC. For EO- and S-type SOC, the SOC dependence
of the critical temperature signals a crossover from BCS to BEC state; at
strong SOC limit, the critical temperature recover those of ideal BEC of
rashbons. The pairing fluctuation induces a pseudogap in the fermionic
excitation spectrum in both superfluid and normal phases. We find that, for EO-
and S-type SOC, even at weak coupling, sufficiently strong SOC can induce
sizable pseudogap. Our research suggests that the spin-orbit coupled Fermi
gases may open new means to the study of the pseudogap formation in fermionic
systems.Comment: V2: 13 pages, 8 figures, more discussions added, matches published
versio
2-Amino-4-(2-chloroÂphenÂyl)-7,7-diÂmethyl-5-oxo-5,6,7,8-tetraÂhydro-4H-chromene-3-carbonitrile hemihydrate
The asymmetric unit of the title compound, C18H17ClN2O2·0.5H2O, contains two organic molÂecules and one solvent water molÂecule. In each organic molÂecule, the cycloÂhexene ring adopts an envelope conformation with the C atom connecting the two methyl groups on the flap; the 4H-pyran ring is nearly planar [maximum deviation = 0.113 (3) Å in one molÂecule and 0.089 (3) Å in the other molÂecule] and is approximately perpendicular to the chloroÂphenyl ring [dihedral angle = 86.43 (15)° in one molÂecule and 89.73 (15)° in the other molÂecule]. InterÂmolecular N—H⋯N, N—H⋯O, O—H⋯O and O—H⋯Cl hydrogen bonding is present in the crystal
Allergenicity and oral tolerance of enzymatic cross-linked tropomyosin evaluated using cell and mouse models
The enzymatic cross-linking of proteins to form high-molecular-weight compounds may alter their sensitization potential. The IgG-/IgE-binding activity, digestibility, allergenicity, and oral tolerance of cross-linked tropomyosin with tyrosinase (CTC) or horseradish peroxidase (CHP) were investigated. ELISA results demonstrated CTC or CHP reduced its IgE-binding activity by 34.5 ± 1.8 and 63.5 ± 0.6%, respectively. Compared with native tropomyosin or CTC, CHP was more easily digested into small fragments; CHP decreased the degranulation of RBL-2H3 cells and increased endocytosis by dendritic cells. CHP can induce oral tolerance and reduce allergenicity in mice by decreasing IgE and IgG1 levels in serum, the production of T-cell cytokines, and the percentage composition of dendritic cells. These findings demonstrate CHP has more potential of reducing the allergenicity than CTC via influencing the morphology of protein, changing the original method of antigen presentation, modulating the Th1/Th2 immunobalance, and inducing the oral tolerance of the allergen tropomyosin
Hyperglycemia Induces the Variations of 11 β
In this paper, we first observed that there were differences in expressions of 11β-HSD1 and PPAR-γ, in hippocampi and hypothalami, among constant hyperglycemia group, control group and the fluctuant glycemia group, using Immunohistochemical analysis. However, whether in expression o f 11β-HSD1 or PPAR-γ, there were no statistic differences between the control group or the fluctuant glycemia group. So, we removed the fluctuant glycemia group, retaining only constant hyperglycemia group and control group, being fed for 8 weeks. After 8 weeks of induction, 11β-HSD1 expression increased and PPAR-γ expression decreased in the constant hyperglycemia group compared with control group, both in hippocampi and hypothalami, by Western Blot. The constant hyperglycemia group also showed impaired cognition in MORRIS watermaze, lower serum corticosterone level, and higher Serum ACTH concentration after 8 weeks. We inferred that the cognition impairment may be related to the abnormal expression of 11β-HSD1 and PPAR-γ in central nerves system. As for 11β-HSD1 is a regulating enzyme, converting the inactive 11-dehydrocorticosterone into the active glucocorticoid corticosterone, thus amplifying GC action in local tissues. It is also well known that high local GC levels can affect the cognitive function. In addition, PPAR-a protective receptor, which is related to cognition
Comparing the contents, functions and neonicotinoid take-up between floral and extrafloral nectar within a single species (Hemerocallis citrina Baroni)
BACKGROUND AND AIMS: Many angiosperms can secrete both floral (FN) and extrafloral (EFN) nectar. However, much remains unclear about how EFN and FN differ in secretion, composition and ecological function, especially when both FN and EFN are secreted on flowers of the same species. METHODS: Hemerocallis citrina flowers secrete both FN and EFN. The FN and EFN traits including volume, presentation pattern and temporal rhythms of secretion were compared by field observation. Sugar and amino acid contents were analysed using regular biochemical methods, whereas the proteome was investigated by combined gel-based and gel-free approaches. Animal feeders on FN and EFN were investigated by field observation. Hemerocallis citrina plants were exposed by soil drenching to two systemic insecticides, acetamiprid and imidacloprid, and the concentration of these in FN and EFN was measured by ultra-high performance liquid chromatography coupled with mass spectrometry. KEY RESULTS: Hemerocallis citrina FN was concentrated and sucrose dominant, secreted in the mature flower tube and served as a reward for pollinators. Conversely, EFN was hexose rich, more dilute and less rich in sugar and amino acids. EFN was secreted on the outside of developing floral buds, and was likely to attract predatory animals for defence. EFN had fewer phenolics, but more pathogenesis-related components, such as chitinase and glucanase. A significantly different proteomic profile and enzymatic activities between FN and EFN suggest that they had different biosynthesis mechanisms. Both neonicotinoid insecticides examined became present in both nectar types soon after application, but in greater concentration within EFN; EFN also attracted a wider range of insect species than FN. CONCLUSIONS: Hemerocallis citrina FN and EFN differed in production, composition and ecological function. The EFN pathway could be a significant way for neonicotinoids to enter the wild food chain, and must be considered when evaluating the risks to the environment of other systemic insecticides
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