Comprehensively Surveying Structure and Function of RING Domains from Drosophila melanogaster

Using a complete set of RING domains from Drosophila melanogaster, all the solved RING domains and cocrystal structures of RING-containing ubiquitin-ligases (RING-E3) and ubiquitin-conjugating enzyme (E2) pairs, we analyzed RING domains structures from their primary to quarternary structures. The results showed that: i) putative orthologs of RING domains between Drosophila melanogaster and the human largely occur (118/139, 84.9%); ii) of the 118 orthologous pairs from Drosophila melanogaster and the human, 117 pairs (117/118, 99.2%) were found to retain entirely uniform domain architectures, only Iap2/Diap2 experienced evolutionary expansion of domain architecture; iii) 4 evolutionary structurally conserved regions (SCRs) are responsible for homologous folding of RING domains at the superfamily level; iv) besides the conserved Cys/His chelating zinc ions, 6 equivalent residues (4 hydrophobic and 2 polar residues) in the SCRs possess good-consensus and conservation- these 4 SCRs function in the structural positioning of 6 equivalent residues as determinants for RING-E3 catalysis; v) members of these RING proteins located nucleus, multiple subcellular compartments, membrane protein and mitochondrion are respectively 42 (42/139, 30.2%), 71 (71/139, 51.1%), 22 (22/139, 15.8%) and 4 (4/139, 2.9%); vi) CG15104 (Topors) and CG1134 (Mul1) in C3HC4, and CG3929 (Deltex) in C3H2C3 seem to display broader E2s binding profiles than other RING-E3s; vii) analyzing intermolecular interfaces of E2/RING-E3 complexes indicate that residues directly interacting with E2s are all from the SCRs in RING domains. Of the 6 residues, 2 hydrophobic ones contribute to constructing the conserved hydrophobic core, while the 2 hydrophobic and 2 polar residues directly participate in E2/RING-E3 interactions. Based on sequence and structural data, SCRs, conserved equivalent residues and features of intermolecular interfaces were extracted, highlighting the presence of a nucleus for RING domain fold and formation of catalytic core in which related residues and regions exhibit preferential evolutionary conservation

An Electrochemical DNA Sensor for p53 Tumor Suppressor Gene Detection

In this work, a sensitive electrochemical DNA sensor based on avidin modified electrode and DNA-functionalized Cds nanoparticle (DFNP) was developed. The DNA-Functionalized Cds nanoparticle contained two kinds of DNA, one was hairpin probe DNA with a biotin at the 3’’ terminal and a thiol at the 5’ terminal, the other is linearity signal DNA. Without hybridized with target DNA, the loop of hairpin impeded biotin linked with avidin on electrode. However, after target hybridization, hairpin was opened and biotin was recognized by avidin resulting in DNA-functionalized Cds nanoparticle was brought on electrode surface. Electrochemical signals of methylene blue (MB) bound to the signal DNA were measured by differential pulse voltammetry (DPV). Introduction By using this new method, we demonstrate that this prototype sensor has been able to detect as low as picomolar p53 tumor suppressor gene with excellent differentiation ability for even single mismatches

An Electrochemical DNA Sensor for p53 Tumor Suppressor Gene Detection

In this work, a sensitive electrochemical DNA sensor based on avidin modified electrode and DNA-functionalized Cds nanoparticle (DFNP) was developed. The DNA-Functionalized Cds nanoparticle contained two kinds of DNA, one was hairpin probe DNA with a biotin at the 3’’ terminal and a thiol at the 5’ terminal, the other is linearity signal DNA. Without hybridized with target DNA, the loop of hairpin impeded biotin linked with avidin on electrode. However, after target hybridization, hairpin was opened and biotin was recognized by avidin resulting in DNA-functionalized Cds nanoparticle was brought on electrode surface. Electrochemical signals of methylene blue (MB) bound to the signal DNA were measured by differential pulse voltammetry (DPV). Introduction By using this new method, we demonstrate that this prototype sensor has been able to detect as low as picomolar p53 tumor suppressor gene with excellent differentiation ability for even single mismatches

Unsupervised Learning of Depth from Monocular Videos Using 3D-2D Corresponding Constraints

Depth estimation can provide tremendous help for object detection, localization, path planning, etc. However, the existing methods based on deep learning have high requirements on computing power and often cannot be directly applied to autonomous moving platforms (AMP). Fifth-generation (5G) mobile and wireless communication systems have attracted the attention of researchers because it provides the network foundation for cloud computing and edge computing, which makes it possible to utilize deep learning method on AMP. This paper proposes a depth prediction method for AMP based on unsupervised learning, which can learn from video sequences and simultaneously estimate the depth structure of the scene and the ego-motion. Compared with the existing unsupervised learning methods, our method makes the spatial correspondence among pixel points consistent with the image area by smoothing the 3D corresponding vector field based on 2D image, which effectively improves the depth prediction ability of the neural network. Our experiments on the KITTI driving dataset demonstrated that our method outperformed other previous learning-based methods. The results on the Apolloscape and Cityscapes datasets show that our proposed method has a strong universality

A New Electrochemical DNA Sensor for Sequence-Specific DNA Detection Based on DNA-functionalized CdS Nanoparticle

In this work, a sensitive electrochemical DNA sensor based on avidin modified electrode and DNA-functionalized CdS nanoparticle (DFCP) was developed. The DNA-Functionalized CdS nanoparticle contained two kinds of DNA, one was hairpin probe DNA with a biotin at the 3’ terminal and a thiol at the 5’ terminal, the other is linearity signal DNA. Without hybridized with target DNA, the loop of hairpin impeded biotin linked with avidin on electrode. However, after target hybridization, hairpin was opened and biotin was recognized by avidin resulting in DNA-functionalized CdS nanoparticle was brought on electrode surface. Electrochemical signals of methylene blue (MB) bound to the signal DNA were measured by differential pulse voltammetry (DPV). Introduction By using this new method, we demonstrate that this prototype sensor has been able to detect as low as picomolar DNA targets with excellent differentiation ability for even single mismatches

A New Electrochemical DNA Sensor for Sequence-Specific DNA Detection Based on DNA-functionalized CdS Nanoparticle

In this work, a sensitive electrochemical DNA sensor based on avidin modified electrode and DNA-functionalized CdS nanoparticle (DFCP) was developed. The DNA-Functionalized CdS nanoparticle contained two kinds of DNA, one was hairpin probe DNA with a biotin at the 3’ terminal and a thiol at the 5’ terminal, the other is linearity signal DNA. Without hybridized with target DNA, the loop of hairpin impeded biotin linked with avidin on electrode. However, after target hybridization, hairpin was opened and biotin was recognized by avidin resulting in DNA-functionalized CdS nanoparticle was brought on electrode surface. Electrochemical signals of methylene blue (MB) bound to the signal DNA were measured by differential pulse voltammetry (DPV). Introduction By using this new method, we demonstrate that this prototype sensor has been able to detect as low as picomolar DNA targets with excellent differentiation ability for even single mismatches

Research Progress on the Damping Mechanism of Magnesium Alloys

Magnesium alloys with high damping, high specific strength and low density have attracted great attention in recent years. However, the application of magnesium alloys is limited by the balance between their mechanical and damping properties. The strength and plasticity of magnesium alloys with high damping performance often cannot meet the industrial requirements. Understanding the damping mechanism of magnesium alloys is significant for developing new materials with high damping and mechanical properties. In this paper, the damping mechanisms and internal factors of the damping properties of magnesium alloys are comprehensively reviewed. Some damping mechanisms have been studied by many scholars, and it has been found that they can be used to explain damping performance. Among existing damping mechanisms, the G-L dislocation theory, twin damping mechanism and interface damping mechanism are considered common. In addition, some specific long-period stacking ordered (LPSO) phases’ crystal structures are conducive to dislocation movement, which is good for improving damping performance. Usually, the damping properties of magnesium alloys are affected by some internal factors directly, such as dislocation density, solute atoms, grain texture and boundaries, etc. These internal factors affect damping performance by influencing the dissipation of energy within the crystal. Scholars are working to find novel damping mechanisms and suitable solute atoms that can improve damping performance. It is important to understand the main damping mechanisms and the internal factors for guiding the development of novel high-damping magnesium alloys

Navel orange fine root nutrient content and rhizosphere effects varied with tree ages and soil depths in a hilly red soil region of China

Root nutrients are required for the growth and development of roots and shoots, which are closely related to soil quality and fruit productivity. In this study, trees of contrasting stand ages, including young, middle-aged, and old trees, were selected in field sites with common management practices in the navel orange (Citrus sinensis) orchards of Southern China. The fine root N decreased with soil depth and the fine root P was higher of old trees (1.82 g kg-1) than young (1.57 g.kg-1) and middle-aged trees (1.37 g. kg-1). Soil organic C, total N, and P generally increased with plant age in the rhizosphere and bulk soils, while reverse trend was found for sucrase and urease activities. Interestingly, acid phosphatase activity was much higher at a lower depth (202 and 82 g.kg-1 OC d-1 for rhizosphere and bulk soils, respectively) than at an upper depth (46 and 43 g.kg-1 OC d-1 for rhizosphere and bulk soils, respectively). In conclusion, root and soil nutrients generally increased with plant growth. Fine root N decreased while fine root P remained unchanged with soil depth due to the content and rhizosphere effect of index at different soil layers related to N and P, respectively