Glass has outstanding optical properties, hardness, and durability, but its applications are limited by its inherent brittleness and poor impact resistance. Lamination and tempering can improve ...impact response but do not suppress brittleness. We propose a bioinspired laminated glass that duplicates the three-dimensional "brick-and-mortar" arrangement of nacre from mollusk shells, with periodic three-dimensional architectures and interlayers made of a transparent thermoplastic elastomer. This material reproduces the "tablet sliding mechanism," which is key to the toughness of natural nacre but has been largely absent in synthetic nacres. Tablet sliding generates nonlinear deformations over large volumes and significantly improves toughness. This nacre-like glass is also two to three times more impact resistant than laminated glass and tempered glass while maintaining high strength and stiffness.
Aims
To isolate a novel endophytic bacterium from Panax ginseng that could have excellent properties in converting ginsenoside Rb1 to ginsenoside Rg3.
Methods and Results
Based on a 16S rDNA gene ...sequence, the strain named GE 17‐7 was identified as Burkholderia sp. This strain has shown the highest activity in converting ginsenoside Rb1 to 20(S)‐ginsenoside Rg3. During the biotransformation of ginsenoside Rb1, the final metabolite was identified by nuclear magnetic resonance analysis and the transformation pathway of ginsenoside Rb1 was also identified by thin‐layer chromatography and high performance liquid chromatography analysis in this study.
Conclusions
We have successfully isolated a β‐glucosidase‐producing endophytic bacterium GE 17‐7 from P. ginseng. Ginsenoside Rg3 was produced by strain GE 17‐7 from ginsenoside Rb1 via ginsenoside Rd.
Significance and Impact of the Study
This is the first report of the conversion of major ginsenoside Rb1 into minor ginsenoside Rg3 by fermentation with Burkholderia sp. endophytic bacteria in P. ginseng. These results suggest a new preparation method for ginsenoside Rg3 using strain GE 17‐7 in the pharmaceutical industry.
The symmetry of the wavefunction describing the Cooper pairs is one of the most fundamental quantities in a superconductor, but for iron-based superconductors it has proved to be problematic to ...determine, owing to their complex multi-band nature. Here we use a first-principles many-body method, including the two-particle vertex function, to study the spin dynamics and the superconducting pairing symmetry of a large number of iron-based compounds. Our results show that these high-temperature superconductors have both dispersive high-energy and strong low-energy commensurate or nearly commensurate spin excitations, which play a dominant role in Cooper pairing. We find three closely competing types of pairing symmetries, which take a very simple form in the space of active iron 3d orbitals, and differ only in the relative quantum mechanical phase of the xz, yz and xy orbital components of the Cooper pair wavefunction. The extensively discussed s+- symmetry appears when contributions from all orbitals have equal sign, whereas a novel orbital-antiphase s+- symmetry emerges when the xy orbital has an opposite sign to the xz and yz orbitals. This orbital-antiphase pairing symmetry agrees well with the angular variation of the superconducting gaps in LiFeAs (refs , ).
This paper investigates the time-dependent behaviour of Murro test embankment in Finland. The embankment was built in 1993 on a soft natural clay deposit, which exhibits large strain anisotropy, ...destructuration and viscosity. The study is based on extensive experimental data from triaxial and oedometer tests on intact and reconstituted soil samples which shed light on the influence of time on mechanical properties, including testing designed for studying soil anisotropy and destructuration. The interpretation of the results is done in the framework of a recently developed elasto-viscoplastic model EVP-SCLAY1S, which is used to simulate the soft soil deposit coupled with Biot's consolidation theory. The determination of model parameters from the test results demonstrates that the model can be relatively easily used for practical applications. Using these parameters, two-dimensional finite-element analyses have been made as large deformation analysis. The comparisons between calculations and measurements demonstrate that the proposed model can be satisfactorily used to describe the time-dependent behaviour of the embankment on structured clay.
The iron pnictide and chalcogenide compounds are a subject of intensive investigations owing to their surprisingly high temperature superconductivity. They all share the same basic building blocks, ...but there is significant variation in their physical properties, such as magnetic ordered moments, effective masses, superconducting gaps and transition temperature (T(c)). Many theoretical techniques have been applied to individual compounds but no consistent description of the microscopic origin of these variations is available. Here we carry out a comparative theoretical study of a large number of iron-based compounds in both their magnetic and paramagnetic states. Taking into account correlation effects and realistic band structures, we describe well the trends in all of the physical properties such as the ordered moments, effective masses and Fermi surfaces across all families of iron compounds, and find them to be in good agreement with experiments. We trace variation in physical properties to variations in the key structural parameters, rather than changes in the screening of the Coulomb interactions. Our results also provide a natural explanation of the strongly Fermi-surface-dependent superconducting gaps observed in experiments.
We show that the numerical renormalization group is a viable multi-band impurity solver for dynamical mean-field theory (DMFT), offering unprecedented real-frequency spectral resolution at ...arbitrarily low energies and temperatures. We use it to obtain a numerically exact DMFT solution to the Hund metal problem for a three-band model on a Bethe lattice at 1/3 filling. The ground state is a Fermi liquid. The one-particle spectral function undergoes a coherence-incoherence crossover with increasing temperature, with spectral weight being transferred from low to high energies. Further, it exhibits a strong particle-hole asymmetry. In the incoherent regime, the self-energy displays approximate power-law behavior for positive frequencies only. The spin and orbital spectral functions show "spin-orbital separation": spin screening occurs at much lower energies than orbital screening. The renormalization group flows clearly reveal the relevant physics at all energy scales.
Covid‐19: countermeasure for N95 mask‐induced pressure sore Yin, Z.Q.
JEADV. Journal of the European Academy of Dermatology and Venereology/Journal of the European Academy of Dermatology and Venereology,
July 2020, Letnik:
34, Številka:
7
Journal Article
For the iron pnictide superconductors, a first-principles calculation of the magnetic state shows that correlations are important if we are to understand both the paramagnetic and magnetic phases. ...Moreover, the pnictides are fundamentally different from the cuprate superconductors in terms of spin and orbital physics.
This research aimed to isolate β‐glycosidase‐producing endophytic fungus in Panax ginseng to achieve biotransformation of ginsenoside Rb1 to ginsenoside C‐K. Of these 15 β‐glucosidase‐producing ...endophytic fungus isolated from ginseng roots, a β‐glucosidase‐producing endophytic fungi GE 17‐18 could hydrolyse major ginsenosides Rb1 to minor ginsenoside C‐K with metabolic pathways: ginsenoside Rb1→ginsenoside Rd→ginsenoside F2→ginsenoside C‐K. Phylogenetic analysis of ITS gene sequences indicated that the strain GE 17‐18 belongs to the genus Arthrinium and is most closely related to Arthrinium sp. HQ832803.1.
Significance and Impact of the Study
This is the first study to provide information of cultivable β‐glycosidase‐producing Endophytic fungus in Panax ginseng. The strain GE 17‐18 has potential to be applied on the preparation for minor ginsenoside C‐K in pharmaceutical industry.
Significance and Impact of the Study: This is the first study to provide information of cultivable β‐glycosidase‐producing Endophytic fungus in Panax ginseng. The strain GE 17‐18 has potential to be applied on the preparation for minor ginsenoside C‐K in pharmaceutical industry.
PDF
