Display omitted
High-entropy alloys (HEA) are of high current interest due to their unique and attractive combination of structural, physical, chemical or magnetic properties. HEA comprise multiple ...principal elements, unlike conventional alloys. The composition space of HEA is enormous and only a minuscule fraction has been studied. Magnetic HEA are a promising alternative to conventional soft magnetic metallic materials, which typically exhibit poor mechanical properties. We review the progress in the development of magnetic HEA. The influence of alloy composition, crystal structure, phase fraction and processing parameters on the magnetic properties are discussed. Magnetic HEA processed by advanced experimental high throughput techniques such as additive manufacturing, co-sputtering, diffusion multiples, rapid prototyping, and designed via combinatorial computational techniques, such as thermodynamic and phase diagram calculations, density functional theory, machine learning etc. are reviewed. Conventional processing techniques are also discussed. Future trends in magnetic HEA are outlined.
Active Wnt proteins are secreted on exosomes Gross, Julia Christina; Chaudhary, Varun; Bartscherer, Kerstin ...
Nature cell biology,
10/2012, Letnik:
14, Številka:
10
Journal Article
Recenzirano
Wnt signalling has important roles during development and in many diseases. As morphogens, hydrophobic Wnt proteins exert their function over a distance to induce patterning and cell differentiation ...decisions. Recent studies have identified several factors that are required for the secretion of Wnt proteins; however, how Wnts travel in the extracellular space remains a largely unresolved question. Here we show that Wnts are secreted on exosomes both during Drosophila development and in human cells. We demonstrate that exosomes carry Wnts on their surface to induce Wnt signalling activity in target cells. Together with the cargo receptor Evi/WIs, Wnts are transported through endosomal compartments onto exosomes, a process that requires the R-SNARE Ykt6. Our study demonstrates an evolutionarily conserved functional role of extracellular vesicular transport of Wnt proteins.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Wnt proteins are secreted signaling factors that regulate cell fate specification and patterning decisions throughout the animal kingdom. In the Drosophila wing epithelium, Wingless (Wg, the homolog ...of Wnt1) is secreted from a narrow strip of cells at the dorsal-ventral boundary. However, the route of Wg secretion in polarized epithelial cells remains poorly understood and key proteins involved in this process are still unknown. Here, we performed an in vivo RNAi screen and identified members of the exocyst complex to be required for apical but not basolateral Wg secretion. Specifically blocking the apical Wg secretion leads to reduced downstream signaling. Using an in vivo 'temporal-rescue' assay, our results further indicate that apically secreted Wg activates target genes that require high signaling activity. In conclusion, our results demonstrate that the exocyst is required for an apical route of Wg secretion from polarized wing epithelial cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The microstructure and magnetic properties of three face-centered cubic (FCC) FeCoNiCrCu(x) high entropy alloys (HEAs) (x = 0, 0.5, 1) are investigated. Interestingly, addition of the nonmagnetic ...element Cu to FeCoNiCr HEA is found to enhance exchange interactions and low temperature saturation magnetization. The paramagnetic to ferromagnetic Curie transition temperature increases from 85 K for FeCoNiCr to 118 K for FeCoNiCrCu. This is counterintuitive since Cu is nonmagnetic; however, atom probe tomography revealed Cu rich clusters containing 5 at% Ni and 1 at% each of Fe, Co, Cr, within FCC matrix, these clusters altered the matrix composition and consequently its magnetic properties.
Display omitted
Wnts are secreted proteins that regulate cell fate during development of all metazoans. Wnt proteins were proposed to spread over several cells to activate signaling directly at a distance. In the
...wing epithelium, an extracellular gradient of the Wnt1 homolog Wingless (Wg) was observed extending over several cells away from producing cells. Surprisingly, however, it was also shown that a membrane-tethered Neurotactin-Wg fusion protein (NRT-Wg) can largely replace endogenous Wg, leading to proper patterning of the wing. Therefore, the functional range of Wg and whether Wg spreading is required for correct tissue patterning remains controversial. Here, by capturing secreted Wg on cells away from the source, we show that Wg acts over a distance of up to 11 cell diameters to induce signaling. Furthermore, cells located outside the reach of extracellular Wg depend on the Frizzled2 receptor to maintain signaling. Frizzled2 expression is increased in the absence of Wg secretion and is required to maintain signaling and cell survival in
wing discs. Together, these results provide insight into the mechanisms by which robust Wnt signaling is achieved in proliferating tissues.
Accelerated development of soft magnetic materials is vital for addressing the challenges associated with improving the performance of electrical machines, transformer cores, electric vehicles etc. A ...combinatorial assessment of the structural, magnetic and mechanical properties of Co100-xFex (x = 30 to 70) and Ni100-xFex (x = 30 to 70) alloys has been carried out on samples fabricated via laser additive manufacturing (AM). Co100-xFex showed a bcc structure in the composition range studied while Ni100-xFex exhibited either single phase fcc or a mixture of fcc and bcc phases, depending on the composition. The saturation magnetization (Ms) for both Co100-xFex and Ni100-xFex compositionally graded alloys increases monotonically with increasing Fe content while the coercivity (Hc) variation is not monotonic. The Ms value of 199.3 emu/g for Co70Fe30 increases to 248 emu/g for Co30Fe70 alloys. Ni70Fe30 exhibits a Ms of 119.8 emu/g which increases to 168.7 emu/g for Ni30Fe70. The peak hardness is 260 VHN for the Co100-xFex series and 160VHN for the Ni100-xFex series. Such AM processed graded magnetic materials can be used for accelerated experiments to discover novel materials.
•Additive manufacturing was used to fabricate functionally graded soft magnetic materials Co100-xFex and Ni100-xFex.•Co100-xFex showed a bcc structure while Ni100-xFex exhibited either single phase fcc or a mixture of fcc and bcc phases.•Coercivity of Co100-xFex exhibits a non-monotonic change with composition.•Saturation magnetization increases monotonically with Fe content in both Co100-xFex and Ni100-xFex.
Wnts are highly-conserved lipid-modified secreted proteins that activate multiple signaling pathways. These pathways regulate crucial processes during various stages of development and maintain ...tissue homeostasis in adults. One of the most fascinating aspects of Wnt protein is that despite being hydrophobic, they are known to travel several cell distances in the extracellular space. Research on Wnts in the past four decades has identified several factors and uncovered mechanisms regulating their expression, secretion, and mode of extracellular travel. More recently, analyses on the importance of Wnt protein gradients in the growth and patterning of developing tissues have recognized the complex interplay of signaling mechanisms that help in maintaining tissue homeostasis. This review aims to present an overview of the evidence for the various modes of Wnt protein secretion and signaling and discuss mechanisms providing precision and robustness to the developing tissues.
The development and measurement of a single layer, wideband, and angularly stable microwave polarization converter (PC), specifically at a low-frequency regime, is still a very challenging task. In ...this article, a quad resonance, mono-band metamaterial polarization converter is fabricated and measured using a non-destructive free-space microwave measurement setup. A comprehensive study of a single-layer metamaterial (MTM) structure using a miniaturized fractal element array reveals that four resonances can be achieved within its operating frequency band to realize a wide operating band. The proposed MTM-PC is inspired by the split-ring resonator (SRR) based fractal geometry to control the linearly polarized electromagnetic (EM) wave in the C-band. The result shows the average polarization conversion ratio over 87% in a single broad frequency band (i.e., 5.5 GHz to 8.0 GHz). A careful study reveals that wideband response at lower frequency is achieved by introducing four resonances due to fractal inspired SRR geometry. Moreover, the proposed structure is the oblique angle insensitive up to 45°. The results reflect the enormous potential of the proposed approach for various practical EM applications.
Gene-gene interactions shape complex phenotypes and modify the effects of mutations during development and disease. The effects of statistical gene-gene interactions on phenotypes have been used to ...assign genes to functional modules. However, directional, epistatic interactions, which reflect regulatory relationships between genes, have been challenging to map at large-scale. Here, we used combinatorial RNA interference and automated single-cell phenotyping to generate a large genetic interaction map for 21 phenotypic features of Drosophila cells. We devised a method that combines genetic interactions on multiple phenotypes to reveal directional relationships. This network reconstructed the sequence of protein activities in mitosis. Moreover, it revealed that the Ras pathway interacts with the SWI/SNF chromatin-remodelling complex, an interaction that we show is conserved in human cancer cells. Our study presents a powerful approach for reconstructing directional regulatory networks and provides a resource for the interpretation of functional consequences of genetic alterations.
A combinatorial assessment of composition‐microstructure‐magnetic property relationships in magnetic high entropy AlCoxCr1‐xFeNi alloy (0 ≤ x ≤ 1) system has been carried out using compositionally ...graded alloys fabricated via laser additive manufacturing. At one end, the AlCoFeNi composition (x = 1) consisted of equiaxed B2 grains, exhibiting very early stages of phase separation (only compositional partitioning) into Ni–Al rich and Fe–Co rich regions within grains of the B2 phase. At the other extreme, the AlCrFeNi composition (x = 0) exhibited grains with pronounced spinodal decomposition, resulting in a B2 + bcc microstructure with the degree of spinodal decomposition progressively increasing with Cr content in these AlCoxCr1–xFeNi alloys. While the saturation magnetization (Ms) monotonically increases six times from x = 0 to x = 1, the coercivity (Hc) variation is non‐monotonic, increasing seven times from x = 0 to x = 0.4, and subsequently decreasing fourteen times from x = 0.4 to x = 1.0. The magnetic phase transition temperature (Tc) for these alloys also increases monotonically with increasing Co content with a second phase transition exhibited in a certain range of compositions between x = 0.6 to x = 0.8. Such substantial changes in the magnetization behavior and properties of magnetic high entropy systems opens possibilities of tuning these alloys for specific soft or hard magnetic component applications.
Laser Engineered Net Shaping (LENS™) process is used for making a compositionally graded magnetic AlCoxCr1–xFeNi HEA (0 ≤ x ≤1). The size scale of phase separation wave, which is affected by the composition, critically affects the magnetic properties like saturation magnetization and coercivity.
PDF
