ABSTRACT
Wnt/ß-catenin signaling plays a crucial role in cancer development, primarily activated by ß-catenin forming a transcription complex with LEF/TCF in the nucleus and initiating the transcription of Wnt target genes. Here, we report that LEF1, a member of the LEF/TCF family, can form intrinsically disordered region (IDR)-dependent condensates with ß-catenin both in vivo and in vitro, which is required for ß-catenin-dependent transcription. Notably, LEF1 with disrupted IDR lost its promoting activity on tumor proliferation and metastasis, which can be restored by substituting with FUS IDR. Our findings provide new insight into the essential role of liquid-liquid phase separation in Wnt/ß-catenin signaling and present a potential new target for cancer therapy.
Subject(s)
Cell Nucleus , beta Catenin , beta Catenin/genetics , Transcriptional Activation/genetics , Wnt Signaling Pathway/geneticsABSTRACT
Reaction-induced porosity is a key factor enabling protracted fluid-rock interactions in the Earth's crust, promoting large-scale mineralogical changes during diagenesis, metamorphism, and ore formation. Here, we show experimentally that the presence of trace amounts of dissolved cerium increases the porosity of hematite (Fe2O3) formed via fluid-induced, redox-independent replacement of magnetite (Fe3O4), thereby increasing the efficiency of coupled magnetite replacement, fluid flow, and element mass transfer. Cerium acts as a catalyst affecting the nucleation and growth of hematite by modifying the Fe2+(aq)/Fe3+(aq) ratio at the reaction interface. Our results demonstrate that trace elements can enhance fluid-mediated mineral replacement reactions, ultimately controlling the kinetics, texture, and composition of fluid-mineral systems. Applied to some of the world's most valuable orebodies, these results provide new insights into how early formation of extensive magnetite alteration may have preconditioned these ore systems for later enhanced metal accumulation, contributing to their sizes and metal endowment.
ABSTRACT
Cellulose nanofibers (CNF) are promising nanomaterials for functional inks and printed sensors, although the potential applications are currently limited by the available functionalization methods. This work outlines a convenient method to grow a novel and highly conductive network of single-crystalline gold nanowires (AuNW) on CNF for use in conductive inks and printed sensors. The CNF are able to reduce Au (III) precursors to Au (0) monomers and generate nucleation sites for the subsequent monomer-by-monomer growth of Au nanocrystals; sodium citrate is used to control the reduction kinetics and the crystal growth. The growth of these AuNW/CNF materials is a three-step process of redox reaction, isotropic nucleation and anisotropic crystallization: the morphology and crystal structure of Au nanocrystals on CNF can be controlled by adjusting the reaction temperature and concentrations of citrate and CNF. The AuNW/CNF materials obtained have been formulated into highly conductive and atmospherically stable inks for use in either directly writing or screen printing. We have demonstrated AuNW/CNF-printed sensors with highly controllable electrical conductivity as well as excellent stability against rinsing and immersion by water and ethanol.
ABSTRACT
Nuclear receptor subfamily 6, group A, member 1 (NR6A1), as an important member of the nuclear receptor family, plays an important role in regulating growth, metabolism, and differentiation of embryonic stem cells. For this reason, the NR6A1 gene is considered to be a promising candidate for economic traits and was found to be associated with body size traits in many livestock. However, no studies have been conducted on NR6A1 in donkeys so far. Thus, in this research, we focused on donkeys and identified a 13 bp deletion in intron-1 of the NR6A1 gene among 408 individuals from Guanzhong and Dezhou donkeys using polyacrylamide gel electrophoresis. Three genotypes were identified, namely II, ID, and DD. The association analysis indicated that the body lengths and body heights5f genotype II individuals were significantly different to those of genotype ID in Dezhou donkeys. Conclusively, the 13 bp deletion was associated with growth traits in both Guanzhong donkeys and Dezhou donkeys, indicating that the NR6A1 gene could be a possible candidate gene in marker-assisted selection for donkey breeding programs.
ABSTRACT
Influence of the conditions for aerobic oxidation of Mn2+(aq) catalysed by the MnxEFG protein complex on the morphology, structure and reactivity of the resulting biogenic manganese oxides (MnOx ) is explored. Physical characterisation of MnOx includes scanning and transmission electron microscopy, and X-ray photoelectron and K-edge Mn, Fe X-ray absorption spectroscopy. This characterisation reveals that the MnOx materials share the structural features of birnessite, yet differ in the degree of structural disorder. Importantly, these biogenic products exhibit strikingly different morphologies that can be easily controlled. Changing the substrate-to-protein ratio produces MnOx either as nm-thin sheets, or rods with diameters below 20â nm, or a combination of the two. Mineralisation in solutions that contain Fe2+(aq) makes solids with significant disorder in the structure, while the presence of Ca2+(aq) facilitates formation of more ordered materials. The (photo)oxidation and (photo)electrocatalytic capacity of the MnOx minerals is examined and correlated with their structural properties.
ABSTRACT
Zeolitic imidazolate framework ZIF-8 beads of 2-3mm in diameter were prepared using a simple one-step phase inversion method. The beads were fabricated by different amounts of ZIF-8 to polyether sulfone (PES) ratios. ZIF-8 played the role of an adsorbent while PES acted as a binder in the composite matrix to keep the ZIF-8 particles. Since ZIF-8 is highly hydrophobic, the beads floated on water and adsorbed oil droplets successfully. This efficient oil adsorption is attributed to the hydrophobicity and high surface area of ZIF-8 particles which can effectively adsorb oil droplets. Different characterization techniques were used to understand the textural properties of the composite beads. The FESEM analysis showed that ZIF-8 particles were well coated and dispersed into the polymer bead composites and some pores are created on the beads surface at higher loadings which facilitated high oil sorption. The nitrogen adsorption-desorption indicated that ZIF-8/PES beads had very high surface area which makes them suitable for adsorption applications. The ZIF-8/PES beads demonstrate easy handling and recycling compared to ZIF-8 powder and showed superior buoyancy and oil sorption capacity compared with natural sorbents like activated carbon. This study shows the phase inversion method can be applied to produce a variety of functional composite bead materials for specific applications like adsorption.
ABSTRACT
Efficient solar-powered water oxidation over the TaON-based anodes requires coupling this photoactive n-type semiconductor to an electrooxidation catalyst to improve the otherwise unsatisfactory activity and stability. Herein, we examine how functionalization with electrodeposited nickel oxide, NiOx , affects the performance of screen-printed TaON photoanodes post-necked with titania (TiO2 -TaON). The effects of the NiOx photo-electrodeposition parameters on the microstructure and photocatalytic performance of the resulting anodes are explored. Enhancements in the transient water oxidation photocurrent densities by sixfold vs. unmodified TiO2 -TaON were achieved with the use of the NiOx /TiO2 -TaON photoanodes. Long-term stability tests reveal a slow but persistent degradation of the performance of the multicomponent photocatalysts under the severely oxidizing conditions of water photo-oxidation coincident with continuous morphological changes in the NiOx deposits.
ABSTRACT
Efficient catalysis of water oxidation represents one of the major challenges en route to efficient sunlight-driven water splitting. Cobalt oxides (CoOx ) have been widely investigated as water oxidation catalysts, although the incorporation of these materials into photoelectrochemical devices has been hindered by a lack of transparency. Herein, the electrosynthesis of transparent CoOx catalyst films is described by utilizing cobalt(II) aminopolycarboxylate complexes as precursors to the oxide. These complexes allow control over the deposition rate and morphology to enable the production of thin, catalytic CoOx films on a conductive substrate, which can be exploited in integrated photoelectrochemical devices. Notably, under a bias of 1.0â V (vs. Ag/AgCl), the film deposited from [Co(NTA)(OH2 )2 ](-) (NTA=nitrilotriacetate) decreased the transmission by only 10 % at λ=500â nm, but still generated >80 % of the water oxidation current produced by a [Co(OH2 )6 ](2+) -derived oxide film whose transmission was only 40 % at λ=500â nm.
Subject(s)
Carboxylic Acids/chemistry , Cobalt/chemistry , Organometallic Compounds/chemistry , Oxides/chemistry , Water/chemistry , Catalysis , Chemistry Techniques, Synthetic , ElectrochemistryABSTRACT
One of the major challenges in the field of biomaterials engineering is the replication of the non-linear elasticity observed in soft tissues. In the present study, non-linearly elastic biomaterials were successfully fabricated from a chemically cross-linked elastomeric poly(glycerol sebacate) (PGS) and thermoplastic poly(L-lactic acid) (PLLA) using the core/shell electrospinning technique. The spun fibrous materials, containing a PGS core and PLLA shell, demonstrated J-shaped stress-strain curves, and having ultimate tensile strength, rupture elongation, and stiffness constants respectively comparable to muscle tissue properties. In vitro evaluations also showed that PGS/PLLA fibrous biomaterials possess excellent biocompatibility, capable of supporting human stem-cell-derived cardiomyocytes over several weeks in culture. Therefore, the core/shell electrospun elastomeric materials provide a new potential scaffold to support cells in the therapy of a wide range of soft tissues exposed to cyclic deformation, such as tendon, ligament, cardiac or smooth muscle and lung epithelium.
Subject(s)
Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Decanoates/chemistry , Elastomers/chemistry , Glycerol/analogs & derivatives , Lactic Acid/chemistry , Mechanical Phenomena , Myocytes, Cardiac/cytology , Polymers/chemistry , Animals , Cell Proliferation/drug effects , Cell Survival/drug effects , Glycerol/chemistry , Humans , Materials Testing , Mice , Myocytes, Cardiac/drug effects , Polyesters , Stress, Mechanical , Tensile Strength , Tissue Scaffolds/chemistryABSTRACT
An efficient delivery system is critical for the success of cell therapy. To deliver cells to a dynamic organ, the biomaterial vehicle should mechanically match with the non-linearly elastic host tissue. In this study, non-linearly elastic biomaterials have been fabricated from a chemically crosslinked elastomeric poly(glycerol sebacate) (PGS) and thermoplastic poly(l-lactic acid) (PLLA) using the core/shell electrospinning technique. The spun fibrous materials containing a PGS core and PLLA shell demonstrate J-shaped stress-strain curves, having ultimate tensile strength (UTS), rupture elongation and stiffness constants of 1 ± 0.2 MPa, 25 ± 3% and 12 ± 2, respectively, which are comparable to skin tissue properties reported previously. Our ex vivo and in vivo trials have shown that the elastomeric mesh supports and fosters the growth of enteric neural crest (ENC) progenitor cells, and that the cell-seeded elastomeric fibrous sheet physically remains in intimate contact with guts after grafting, providing the effective delivery of the progenitor cells to an embryonic and post-natal gut environment.
Subject(s)
Biocompatible Materials/chemistry , Colon/surgery , Decanoates/chemistry , Glycerol/analogs & derivatives , Lactic Acid/chemistry , Neural Crest/cytology , Polymers/chemistry , Stem Cell Transplantation , Tissue Scaffolds/chemistry , Animals , Cell Proliferation , Cell Survival , Cells, Cultured , Colon/cytology , Elasticity , Glycerol/chemistry , Mice , Mice, Inbred C57BL , Polyesters , Tensile Strength , Tissue EngineeringABSTRACT
Enzymatic degradation is a major feature of polyester implants in vivo. An in vitro experimental protocol that can simulate and predict the in vivo enzymatic degradation kinetics of implants is of importance not only to our understanding of the scientific issue, but also to the well-being of animals. In this study, we explored the enzymatic degradation of PGS-based materials in vitro, in tissue culture medium or a buffer solution at the pH optima and under static or cyclic mechanical-loading conditions, in the presence of defined concentrations of an esterase. Surprisingly, it was found that the in vitro enzymatic degradation rates of the PGS-based materials were higher in the tissue culture medium than in the buffered solution at the optimum pH 8. The in vitro enzymatic degradation rate of PGS-based biomaterials crosslinked at 125°C for 2 days was approximately 0.6-0.9 mm/month in tissue culture medium, which falls within the range of in vivo degradation rates (0.2-1.5mm/month) of PGS crosslinked at similar conditions. Enzymatic degradation was also further enhanced in relation to mechanical deformation. Hence, in vitro enzymatic degradation of PGS materials conducted in tissue culture medium under appropriate enzymatic conditions can quantitatively capture the features of in vivo degradation of PGS-based materials and can be used to indicate effective strategies for tuning the degradation rates of this material system prior to animal model testing.