Antheraea pernyi Silk Fiber: A Potential Resource for Artificially Biospinning Spider Dragline Silk

The outstanding properties of spider dragline silk are likely to be determined by a combination of the primary sequences and the secondary structure of the silk proteins. Antheraea pernyi silk has more similar sequences to spider dragline silk than the silk from its domestic counterpart, Bombyx mori. This makes it much potential as a resource for biospinning spider dragline silk. This paper further verified its possibility as the resource from the mechanical properties and the structures of the A. pernyi silks prepared by forcible reeling. It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk. Under a controlled reeling speed of 95 mm/s, the breaking energy was 1.04 × 105 J/kg, the tensile strength was 639 MPa and the initial modulus was 9.9 GPa. It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk. The tensile properties, the optical orientation and the β-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s

Rhizosphere Microenvironments of Eight Common Deciduous Fruit Trees Were Shaped by Microbes in Northern China

The rhizosphere microenvironment is the site of nutrient circulation and microbial community formation, and thus is an ongoing topic of research. Although research on this topic is extensive, studies into the rhizosphere microenvironment of fruit trees remain rare. To elucidate the mechanisms driving the fruit tree rhizosphere microenvironment, we assessed soil physicochemical properties, enzyme activities, the community-level physiological profile (CLPP) and microbial diversity in rhizospheric soils of eight common deciduous fruit trees in northern China. We found that the available minerals, pH, enzyme activities, microbial utilization of six types of carbon (C) substrates, and microbial diversity in the rhizosphere varied among tree species. Redundancy analysis (RDA) showed that rhizosphere microenvironmental parameters (ammonia nitrogen content, soil pH and invertase activity) were closely related to the soil microbial community. Further analysis revealed that the soil microbial utilization of six C sources, nitrate nitrogen content, and invertase activity were negatively correlated with Ambiguous species and Alternaria; however, these groups were positively correlated with pH. The ammonia nitrogen content was positively correlated with C source utilization and negatively correlated with Ambiguous, Lysobacter, Nitrospira, Alternaria, Fusarium, and Colletotrichum. Interestingly, invertase was closely linked to the microbial community, especially fungal diversity, and was positively correlated with plant-beneficial microbes such as Mortierella, Geomyces, Lysobacter, and Chaetomium, but negatively correlated with pathogenic microbes such as Alternaria, Fusarium, and Colletotrichum. Hence, rhizosphere soil physicochemical properties, enzyme activities and microbial community were significantly affected by tree species. Additionally, a variety of environmental factors were closely related to the microbial community in the rhizospheric soils of eight species of deciduous fruit trees

Nonreciprocal microwave responses in Nb/Au/NbSe₂ Josephson junctions

The nonreciprocal Josephson junction, the Josephson diode, opens a door for superconducting circuit technology. Here, we report on nonreciprocal behaviors in Nb/Au/NbSe2 Josephson junctions. The strong asymmetry could be seen in the current-voltage characteristics, which most likely arises from time symmetry breaking due to Abrikosov vortices, indicated by an asymmetric Fraunhofer pattern. The nonreciprocal microwave responses are systematically investigated compared to a numerical simulation based on a resistively and capacitively shunted junction model, which could well capture the asymmetric behaviors and rule out some artifacts such as other parasitic Josephson-like structures. Based on the nonreciprocal microwave responses, we put forward a proposal for a switchable Josephson diode controlled by an external microwave, which might provide an opportunity for next-generation microwave-related superconducting circuits.Published versionWe gratefully acknowledge financial support from the Scientific Research Foundation for Ph.D., Nanjing Institute of Technology (Grant Nos. YKJ2019108 and YKJ2019109) and the Jiangsu Province Double Innovation Doctor

Primary mesenchymal chondrosarcoma of the kidney with synchronous implant and infiltrating urothelial carcinoma of the ureter

<p>Abstract</p> <p>Primary mesenchymal chondrosarcoma of the kidney is rare, and it shows distinct undifferentiated tumor cells and well differentiated cartilagenous components. Also assident infiltrating urothelial carcinoma of the ureter is an extremely rare cancer. We report a case of primary mesenchymal chondrosarcoma occurring in the left kidney with an ipsilateral and distinct distal ureteric implant, and a coexisting infiltrating urothelial carcinoma of the ureter in a 64-year-old man. Histopathological examination and immunohistochemical studuies showed the classic features of mesenchymal chondrosarcoma in kidney, as well as a few infiltrating urothelial in ureter. Multitarget fluorescence in situ hybridization (FISH) suggested that the development of the urothelial carcinoma in the ureter may be triggered or induced by the chondrosarcoma component. The patient died 2 month after left nephro-ureterectomy. This is the first reported case of a primary mesenchymal chondrosarcoma of the kidney with coexisting infiltrating urothelial carcinoma of the ureter.</p> <p>Virtual Slides</p> <p>The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1522835667751019</p

Antheraea pernyi silk fiber: a potential resource for artificially biospinning spider dragline silk

The outstanding properties of spider dragline silk are likely to be determined by a combination of the primary sequences and the secondary structure of the silk proteins. Antheraea pernyi silk has more similar sequences to spider dragline silk than the silk from its domestic counterpart, Bombyx mori. This makes it much potential as a resource for biospinning spider dragline silk. This paper further verified its possibility as the resource from the mechanical properties and the structures of the A. pernyi silks prepared by forcible reeling. It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk. Under a controlled reeling speed of 95 mm/s, the breaking energy was 1.04 × 10 5 J/kg, the tensile strength was 639 MPa and the initial modulus was 9.9 GPa. It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk. The tensile properties, the optical orientation and the β-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s

Role of humidity on the structures and properties of regenerated silk fibers

Silk fiber was processed from highly concentrated spinning dope to solid fibers along with water removal. To understand the mechanism of water removal during silk fiber spinning process, a microfluidic chip was designed and applied to investigate the structures and mechanical properties of two kinds of regenerated silk fibroin fibers dry-spun at different relative humidity. The experimental results showed that the diameters of the fibers spun at 40% RH are always larger than the fibers spun at 50% RH due to different removal rates of water. The fibers spun at low humidity contain more β-sheet structure and lower degree of chain orientation and crystalline orientation. These results indicate that the fast phase transition of silk fibroin from sol–gel to silk fiber undergoes with rapid water removal and higher fiber orientation relates to more residue water and drawing force

A CO2-tolerant SrCo0.8Fe0.15Zr0.05O3−δ cathode for proton-conducting solid oxide fuel cells

SrCo0.8Fe0.2O3−δ (SCF) exhibits high ionic–electronic conductivity. However, its instability in the presence of CO2 restricts its application in electrochemical devices. In this study, 5 mol% zirconium was introduced into SCF to improve its structural stability and CO2 tolerance. SrCo0.8Fe0.15Zr0.05O3−δ (SCFZ) showed metallic electrical conductivity above 500 °C. Furthermore, X-ray diffraction and CO2-temperature programmed desorption experiments indicated that SCFZ possessed adequate structural stability and CO2 tolerance. The oxygen reduction activity and CO2 tolerance were studied using a symmetrical cell, SCFZ|BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb)|SCFZ. The electrochemical performances of the SCFZ material as a cathode were investigated systematically for proton-conducting solid oxide fuel cells (H+-SOFCs) with a configuration of NiO–BZCYYb|BZCYYb|SCFZ–BZCYYb. The output of 712 mW cm−2 at 700 °C and a durability test of over 300 h indicated that SCFZ had significant structural stability and CO2-tolerance

Reinforced and Ultraviolet Resistant Silks from Silkworms Fed with Titanium Dioxide Nanoparticles

As the perfect combination of strength and luster, silkworm silks have been widely used in many fields but still need improvements. This paper demonstrates an <i>in vivo</i> uptake of titanium dioxide (TiO₂) nanoparticles by silkworms, leading to the direct production of intrinsically modified silk. The nanoparticles can be easily incorporated into the silk gland of silkworm by using this method due to the interactions between TiO₂ and silk fibroin molecules. Infrared spectra indicate that TiO₂ nanoparticles confine the conformation transition of silk fibroin from random coil/α-helix to β-sheet. Results of synchrotron radiation wide-angle X-ray diffraction and small-angle X-ray scattering suggest that modified silks have lower crystallinity, higher mesophase content, and higher Herman’s orientation functions of crystalline region and mesophase region than control group. The breaking strength and elongation at break of the modified silk can be improved up to 548 ± 33 MPa and 16.7 ± 0.8%, respectively, by adding 1% nanoanatase into the artificial diet. Moreover, the TiO₂-1% modified silk shows well-improved ultraviolet resistant property as the breaking strength only decreased 15.9% after exposure to ultraviolet light for 3 h. The <i>in vivo</i> modification method for silkworm silk is a green, sustainable, and promising route for commercial production in the future