Channel capacity of the ribosome.

Translation is one of the most fundamental processes in the biological cell. Because of the central role that translation plays across all domains of life, the enzyme that carries out this process, the ribosome, is required to process information with high accuracy. This accuracy often approaches values near unity experimentally. In this paper, we model the ribosome as an information channel and demonstrate mathematically that this biological machine has information-processing capabilities that have not been recognized previously. In particular, we calculate bounds on the ribosome's theoretical Shannon capacity and numerically approximate this capacity. Finally, by incorporating estimates on the ribosome's operation time, we show that the ribosome operates at speeds safely below its capacity, allowing the ribosome to process information with an arbitrary degree of error. Our results show that the ribosome achieves a high accuracy in line with purely information-theoretic means.

Unidirectional water transport on a two-dimensional hydrophilic channel with anisotropic superhydrophobic barriers.

Many creatures have a unique anisotropic structure and special wettability on their skins, presenting intriguing water transporting properties. Inspired by the biosphere, a two-dimensional titanium dioxide-based hydrophilic channel possessing anisotropic superhydrophobic barriers was synthesized. This channel demonstrates unidirectional water transporting properties. When water is injected into the channel, fluid tends to spread in a specific direction. An asymmetric spreading resistance is generated by the different interaction modes between the liquid and superhydrophobic barriers. The superhydrophobic barriers are designed as two main styles: line and curve. As for line barriers, the included angle between barrier and horizontal is the key parameter for the unidirectional water transporting ability whereas, for curve barriers, the radius is an important variable. The best design scheme for unidirectional water transporting properties could be found by varying the parameters of these two types of barriers in the channel. Overall, this study is expected to have a significant implication in the water transporting field.

Fog collection on a superhydrophobic/hydrophilic composite spine surface.

Inspired by numerous plants and animals living in arid conditions, a composite surface with the fog collection capacity has been fabricated in this study. The surface is composed of polydimethylsiloxane-based spine-arrays and a ZnO micron structure. Two wetting properties are integrated on the surface of the spine structure; the tip of spine is processed as hydrophilic and other parts such as the root region of spine and the base are processed as superhydrophobic. When the surface is in the saturated fog flow with a specific tilt angle, the fog deposits on spines and forms condensed droplets; then, the droplets fall off the surface due to gravity. Further, a new cycle of fog collection begins. In this study, we find that the percentage of the hydrophilic tip in the overall spine structure length, the distance between two spines and the tilt angle of surface are the key factors for improving the efficiency of fog collection. Such a composite surface might be an ideal platform for fog collection from air.

Core regulatory RNA molecules identified in articular cartilage stem/progenitor cells during osteoarthritis progression.

Aim: To assess cartilage-derived stem/progenitor cells (CSPCs) in osteoarthritis (OA) by employing mRNA-miRNA-circRNA-lncRNA network biology approach. Methods: Differentially expressed (DE) RNAs in CSPCs from 2-/4-/8-month-old STR/Ort and CBA mice were identified to construct networks via RNA sequencing. Results: Compared with age-matched CBA mice, 4-/8-month-old STR/Ort mice had cartilage lesions and their CSPCs exhibited lower proliferative and differentiation capacity (decreased CD44 and CD90), and identified 7082 DE RNAs in STR/Ort mice were associated with strain differences or OA progression. OA-related core RNAs were identified via the networks constructed with the predominant DE RNAs, which were involved in the signaling pathways (NF-κB/MAPK/Hippo/Wnt/TGF-ß/cytoskeleton organization). The core RNAs (miR-322-5p/miR-493-5p/miR-378c/CPNE1/Cdh2/PRDM16/CTGF/NCAM1) were validated in CSPCs from OA patients. Conclusion: RNA-based networks identifying core RNAs and signaling pathways contribute to CSPC-dependent OA mechanisms.

Autophagy- and MMP-2/9-mediated Reduction and Redistribution of ZO-1 Contribute to Hyperglycemia-increased Blood-Brain Barrier Permeability During Early Reperfusion in Stroke.

Post-stroke hyperglycemia during early reperfusion increases blood-brain barrier (BBB) permeability and subsequently aggravates brain injury and clinical prognosis. The decreased level of tight junction proteins (TJPs) has been reported but the underlying mechanism remains largely elusive. Herein we designed to investigate the detailed molecular events in brain microvascular endothelial cells (BMECs) ex and in vivo. After oxygen-glucose deprivation (OGD) for 90 min and reperfusion with 8 or 16 mM glucose for 30 min, glucose at 16 mM caused significant decrease in the TJP expression and particularly ZO-1 redistribution from membrane to cytoplasm of BMECs. High glucose also markedly promoted the secretion of MMP-2/9 and oxidative/nitrosative stress, enhanced autophagy and increased the Caveolin-1 and LAMP-2 expression. Moreover, in vivo experiments demonstrated that rapamycin-enhanced autophagy further caused ZO-1 reduction and the increased BBB permeability. Therefore, high-glucose exposure in the early reperfusion causes the BBB disruption, with MMP-2/9-mediated extracellular degradation, caveolin-1-mediated intracellular translocation and autophagy-lysosome-mediated degradation of ZO-1 protein all together involved in the process. The role of MMP-2/-9 and autophagy in the modulation of paracellular permeability was confirmed by pharmacological inhibition. Therefore, our findings may provide new insights into targeting ZO-1 regulation for the purpose of significantly improving the clinical prognosis of ischemic stroke.

Seed-induced growing various TiO2 nanostructures on g-C3N4 nanosheets with much enhanced photocatalytic activity under visible light.

In this study, we provide a seed-induced solvothermal method to grow various TiO2 nanostructures on the surfaces of g-C3N4, such as 0D nanoparticles, 1D nanowires 2D nanosheets and 3D mesoporous nanocrystals. We show that the "seeding" endows g-C3N4 with anchoring sites toward the heterogeneous nucleation growth of TiO2, and the distribution of the loaded TiO2 can be controlled by tuning the amount of nucleation in the dispersion. Among synthesized nanostructures, seed-grown Meso-TiO2/g-C3N4 hybrids exhibit the highest photocatalytic activity upon visible light irradiation using methyl orange and phenol as probe organics, which are about 2-4 times and 29-37 times as high as those of direct-grown Meso-TiO2/g-C3N4 without seeding and bare g-C3N4 for degradation of MO and phenol, respectively. The enhancement of photocatalysis can be ascribed to the adequate separation of photogenerated electrons at the heterojunction interfaces and dominant contribution of photoinduced holes mainly caused by the well-constructed nano- architectures.