1,025 research outputs found
Flemingia macrophylla Extract Ameliorates Experimental Osteoporosis in Ovariectomized Rats
Flemingia macrophylla (Leguminosae), a native plant of Taiwan, is used as folk medicine. An in vitro study showed that a 75% ethanolic extract of F. macrophylla (FME) inhibited osteoclast differentiation of cultured rat bone marrow cells, and the active component, lespedezaflavanone A (LDF-A), was isolated. It was found that oral administration of FME for 13 weeks suppressed bone loss in ovariectomized rats, an experimental model of osteoporosis. In addition, FME decreased urinary deoxypyridinoline concentrations but did not inhibit serum alkaline phosphatase activities, indicating that it ameliorated bone loss via inhibition of bone resorption. These results suggest that FME may represent a useful remedy for the treatment of bone resorption diseases, such as osteoporosis. In addition, LDF-A could be used as a marker compound to control the quality of FME
Intracellular complexes of the early-onset torsion dystonia-associated AAA+ ATPase TorsinA
A single GAG codon deletion in the gene encoding torsinA is linked to most cases of early-onset torsion dystonia. TorsinA is an ER-localized membrane-associated ATPase from the AAA+ superfamily with an unknown biological function. We investigated the formation of oligomeric complexes of torsinA in cultured mammalian cells and found that wild type torsinA associates into a complex with a molecular weight consistent with that of a homohexamer. Interestingly, the dystonia-linked variant torsinAĪE displayed a reduced propensity to form the oligomers compared to the wild type protein. We also discovered that the deletion of the N-terminal membrane-associating region of torsinA abolished oligomer formation. Our results demonstrate that the dystonia-linked mutation in the torsinA gene produces a protein variant that is deficient in maintaining its oligomeric state and suggest that ER membrane association is required to stabilize the torsinA complex
Sensitivity of Space-based Gravitational-Wave Interferometers to Ultralight Bosonic Fields and Dark Matter
Ultralight bosonic fields (ULBFs) are predicted by various theories beyond
the standard model of particle physics and are viable candidates of cold dark
matter. There have been increasing interests to search for the ULBFs in
physical and astronomical experiments. In this paper, we investigate the
sensitivity of several planned space-based gravitational-wave interferometers
to ultralight scalar and vector fields. Using time-delay interferometry (TDI)
to suppress the overwhelming laser frequency noise, we derive the averaged
transfer functions of different TDI combinations to scalar and vector fields,
and estimate the impacts of bosonic field's velocities. We obtain the
sensitivity curves for LISA, Taiji and TianQin, and explore their projected
constraints on the couplings between ULBFs and standard model particles,
illustrating with the ULBFs as dark matter.Comment: 33 pages, 8 figure
Antiosteoporotic Activity of Dioscorea alata L. cv. Phyto through Driving Mesenchymal Stem Cells Differentiation for Bone Formation
The aim of this study was to evaluate the effect of an ethanol extract of the rhizomes of Dioscorea alata L. cv. Phyto, Dispo85E, on bone formation and to investigate the mechanisms involved. Our results showed that Dispo85E increased the activity of alkaline phosphatase (ALP) and bone nodule formation in primary bone marrow cultures. In addition, Dispo85E stimulated pluripotent C3H10T1/2 stem cells to differentiate into osteoblasts rather than adipocytes. Our in vivo data indicated that Dispo85E promotes osteoblastogenesis by increasing ALP activity and bone nodule formation in both intact and ovariectomized (OVX) mice. Microcomputed tomography (Ī¼CT) analysis also showed that Dispo85E ameliorates the deterioration of trabecular bone mineral density (tBMD), trabecular bone volume/total volume (BV/TV), and trabecular bone number (Tb.N) in OVX mice. Our results suggested that Dispo85E is a botanical drug with a novel mechanism that drives the lineage-specific differentiation of bone marrow stromal cells and is a candidate drug for osteoporosis therapy
Lipophagy mediated carbohydrate-induced changes of lipid metabolism via oxidative stress, endoplasmic reticulum (ER) stress and ChREBP/PPARĪ³ pathways
Development of a thiophene derivative modified LDH coating for Mg alloy corrosion protection.
A new thiophene derivative corrosion inhibitor (CI) was developed to functionalize the layered double hydroxide (LDH) primer on Mg alloy to enhance corrosion protection. Compared with bare LDH coating, the composite coatings consisting of a MgAl-LDH primer and an outer CI layer showed highly compact surface structures without large pores and gaps, thereby indicating the enhanced capability to resist the penetration of corrosive species. Electrochemical tests revealed that the MgAl-LDH film modified with the newly synthesized CI exhibited higher charge transfer resistance and lower corrosion current density than films modified with commercial CIs. The highest enhancement in corrosion resistance was linked to the film's ability to repair physical damage by forming precipitates through chemical complexation and adsorption of the CIs. These findings open up new opportunities for the design and synthesis of a thiophene-contained inhibitor to modify LDH films and to obtain a composite coating with superior corrosion protection
Extended Kerr effect of polymer-stabilized blue-phase liquid crystals
Electric-field-induced birefringence of a polymer-stabilized blue-phase liquid crystal (BPLC) is investigated. In the low field region, conventional Kerr effect holds. As the electric field increases, the induced birefringence gradually saturates and deviates from Kerr effect. An exponential convergence model, called extended Kerr effect, is proposed to fit the experimental data. Good agreement between experiment and model is obtained. This extended Kerr effect will make a significant impact to the optimization of emerging BPLC display devices
Formation and properties of glycinin-rich and -conglycinin-rich soy protein isolate gels induced by microbial transglutaminase
Abstract The gelation and gel properties of glycinin-rich and -conglycinin-rich soy protein isolates (SPIs) induced by microbial transglutaminase (MTGase) were investigated. At the same enzyme and protein substrate concentrations, the on-set of gelation of native SPI and the viscoelasticity development of correspondingly formed gels depended upon the relative ratio of glycinin to -conglycinin. The turbidity analysis showed that the glycinin components also contributed to the increase in the turbidity of SPI solutions incubated with MTGase (at 37Ā°C). Textural proWle analysis indicated that the glycinin components of SPIs principally contributed to the hardness, fracturability, gumminess and chewiness values of corresponding gels, while the cohesiveness and springness were mainly associated with the -conglycinin components. The strength of MTGase-induced gels of various kinds of SPIs could be signiWcantly improved by the thermal treatment. The protein solubility analyses of MTGase-induced gels, indicated that besides the covalent cross-links, hydrophobic and H-bondings and disulWde bonds were involved in the formation and maintenance of the glycinin-rich SPI gels, while in -conglycinin-rich SPI case, the hydrophobic and H-bondings were the principal forces responsible for the maintenance of the gel structure. The results suggested that various kinds of SPI gels with diVerent properties could be induced by MTGase, through controlling the glycinin to -conglycinin ratio
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