50 research outputs found
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
Intestinal Fibroblast/Myofibroblast TRP Channels in Inflammatory Bowel Disease
Inflammatory bowel disease (IBD) is characterized by the repeated cycles of inflammation and healing of the gut, which ultimately progress into intestinal fibrosis. Colonic fibroblast/myofibroblast’s functions such as transformation, proliferation, invasion, migration, stress fiber formation, collagen synthesis, and cytokine/chemokine secretion are well estimated. However, the detailed mechanism can rarely be found so far. Thus, we focused on transient receptor potential (TRP) protein super family activated by various physical/chemical stimulations based on the above-described recognitions and also conducted the following examinations for the potential roles in Ca2+ signal transduction in fibroblast/myofibroblasts cells, which play an important role in intestinal inflammation and tissue remodeling. This chapter not only facilitates the understanding about the new role of intestinal fibroblast/myofibroblasts TRP channel for regulating inflammation, fibrotic processes but also suggests a novel molecular target of IBD treatment in future
Identification of Human ABAD Inhibitors for Rescuing Aβ-Mediated Mitochondrial Dysfunction
Amyloid beta (Aβ) binding alcohol dehydrogenase (ABAD) is a cellular cofactor for promoting (Aβ)-mediated mitochondrial and neuronal dysfunction, and cognitive decline in transgenic Alzheimer's disease (AD) mouse models. Targeting mitochondrial ABAD may represent a novel therapeutic strategy against AD. Here, we report the biological activity of small molecule ABAD inhibitors. Using in vitro surface plasmon resonance (SPR) studies, we synthesized compounds with strong binding affinities for ABAD. Further, these ABAD inhibitors (ABAD-4a and 4b) reduced ABAD enzyme activity and administration of phosphonate derivatives of ABAD inhibitors antagonized calcium-mediated mitochondrial swelling. Importantly, these compounds also abolished Aβ-induced mitochondrial dysfunction as shown by increased cytochrome c oxidase and adenosine-5′-triphosphate levels, suggesting protective mitochondrial function effects of these synthesized compounds. Thus, these compounds are potential candidates for further pharmacologic development to target ABAD to improve mitochondrial function
A CsI hodoscope on CSHINE for Bremsstrahlung {\gamma}-rays in Heavy Ion Reactions
Bremsstrahlung production in heavy ion reactions at Fermi energies
carries important physical information including the nuclear symmetry energy at
supra-saturation densities. In order to detect the high energy Bremsstrahlung
rays, a hodoscope consisting of 15 CsI(Tl) crystal read out by photo
multiplier tubes has been built, tested and operated in experiment. The
resolution, efficiency and linear response of the units to rays have
been studied using radioactive source and reactions. The
inherent energy resolution of is obtained.
Reconstruction method has been established through Geant 4 simulations,
reproducing the experimental results where comparison can be made. Using the
reconstruction method developed, the whole efficiency of the hodoscope is about
against the emissions at the target position,
exhibiting insignificant dependence on the energy of incident rays
above 20 MeV. The hodoscope is operated in the experiment of Kr +
Sn at 25 MeV/u, and a full energy spectrum up to 80 MeV has
been obtained.Comment: 9 pages, 19 figure
Probing high-momentum component in nucleon momentum distribution by neutron-proton bremsstrahlung {\gamma}-rays in heavy ion reactions
The high momentum tail (HMT) of nucleons, as a signature of the short-range
correlations in nuclei, has been investigated by the high-energy bremsstrahlung
rays produced in Kr + Sn at 25 MeV/u. The energetic
photons are measured by a CsI(Tl) hodoscope mounted on the spectrometer CSHINE.
The energy spectrum above 30 MeV can be reproduced by the IBUU model
calculations incorporating the photon production channel from process in
which the HMTs of nucleons is considered. A non-zero HMT ratio of about
is favored by the data. The effect of the capture channel is
demonstrated
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
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
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 (TiO<sub>2</sub>) 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 TiO<sub>2</sub> and silk
fibroin molecules. Infrared spectra indicate that TiO<sub>2</sub> 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 TiO<sub>2</sub>-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