412 research outputs found
Fabrication of Nanostructured Electroforming Copper Layer by Means of an Ultrasonic-assisted Mechanical Treatment
AbstractElectroformed copper layer with nanostructure is obtained using a subsequent mechanical treatment under the conditions of ultrasonic vibration according to the demand of high performance material in aeronautics. The microstructure of the electroformed copper layer is observed by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The tensile strength is evaluated with a tensile tester. It is found that bulk crystal of electroformed copper's surface layer is changed to nanocrystals (about 10 nm in size) after the ultrasonic-assisted mechanical treatment (UMT) but the whole monocrystalline structure still remains. The tensile strength exhibited by the new copper layer is two times better than the regular electroformed copper layer, while the fracture strain remains constant. In addition, the strengthening mechanism of UMT process is proved to be dislocation strengthening mechanism
BBF RFC 101: Logic Gene Module Standard
This Request for Comments (RFC) describes a new framework for standardize logic gene relations among gene circuits. Each type of logic module in gene circuit can be summarized in a standard device in electronics. In this paper, we collect several frequently-used logic modules and the corresponding classic gene structure
BBF RFC97: Genetic Circuit Standard 1.0
Current, there is well adopted documentation of biobricks. The Registry of Standard Biology Part set the standard documentation for biobrick. However, there is no standard way to document a genetic circuit, what information should be included in a description of a genetic circuit. We have therefore develop the technique standard for recording a genetic circuits. This standard will help the sharing of genetic circuits’ information among synthetic biology community
Leucine-rich repeat transmembrane proteins instruct discrete dendrite targeting in an olfactory map
Olfactory systems utilize discrete neural pathways to process and integrate odorant information. In Drosophila, axons of first-order olfactory receptor neurons (ORNs) and dendrites of second-order projection neurons (PNs) form class-specific synaptic connections at ~50 glomeruli. The mechanisms underlying PN dendrite targeting to distinct glomeruli in a three-dimensional discrete neural map are unclear. We found that the leucine-rich repeat (LRR) transmembrane protein Capricious (Caps) was differentially expressed in different classes of PNs. Loss-of-function and gain-of-function studies indicated that Caps instructs the segregation of Caps-positive and Caps-negative PN dendrites to discrete glomerular targets. Moreover, Caps-mediated PN dendrite targeting was independent of presynaptic ORNs and did not involve homophilic interactions. The closely related protein Tartan was partially redundant with Caps. These LRR proteins are probably part of a combinatorial cell-surface code that instructs discrete olfactory map formation
TSPAN8 promotes cancer cell stemness via activation of sonic Hedgehog signaling
Cancer stem cells (CSCs) represent a major source of treatment resistance and tumor progression. However, regulation of CSCs stemness is not entirely understood. Here, we report that TSPAN8 expression is upregulated in breast CSCs, promotes the expression of the stemness gene NANOG, OCT4, and ALDHA1, and correlates with therapeutic resistance. Mechanistically, TSPAN8 interacts with PTCH1 and inhibits the degradation of the SHH/PTCH1 complex through recruitment of deubiquitinating enzyme ATXN3. This results in the translocation of SMO to cilia, downstream gene expression, resistance of CSCs to chemotherapeutic agents, and enhances tumor formation in mice. Accordingly, expression levels of TSPAN8, PTCH1, SHH, and ATXN3 are positively correlated in human breast cancer specimens, and high TSPAN8 and ATXN3 expression levels correlate with poor prognosis. These findings reveal a molecular basis of TSPAN8-enhanced Sonic Hedgehog signaling and highlight a role for TSPAN8 in promoting cancer stemness
Spatial Analysis on Resource Utilization, Environmental Consequences and Sustainability of Rice–Crayfish Rotation System in Jianghan Plain, China
The rice–crayfish rotation system (RCR), originating in the Jianghan Plain, is developing rapidly in various regions of China and has been characterized by unbalanced regional development, which has also led to widespread concerns and discussion on its environmental impacts and sustainability. This study selects representative RCR production areas in the Jianghan Plain, including Jianli, Qianjiang, Shishou, Shayang, Gong’an and Honghu, to analyze resource inputs, resource utilization efficiency, environmental impacts and sustainability by employing the emergy analysis method. Our analysis of Jianli, Honghu, Qianjiang, Gong’an, Shishou and Shayang reports total emergy inputs ranging from 6.46 × 1016 to 8.25 × 1016, with renewable rates between 78.38% and 84.34%. Shishou leads in the unit emergy value (5.58 × 10−1) and the emergy yield ratio (5.30). The sustainability evaluation finds that the environmental loading ratio is from 0.19 to 0.28 and the emergy index for sustainable development varies between 1.27 and 3.00. This analysis indicates that the southern regions have higher inputs and efficiency, with southeastern areas showing lower environmental impact and higher sustainability. We also underscore the impact of non-renewable resources on environmental outcomes and sustainability, suggesting tailored development strategies for the rice–crayfish rotation system’s optimization and sustainable growth.This article is published as Shi, H.; Han, G.; Hu, N.; Qu, S.; Zhu, L. Spatial Analysis on Resource Utilization, Environmental Consequences and Sustainability of Rice–Crayfish Rotation System in Jianghan Plain, China. Agronomy 2024, 14, 1071. https://doi.org/10.3390/agronomy14051071. © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)
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