Suppression of nano-channel ion conductance by electro-osmotic flow in nano-channels with weakly overlapping electrical double layers

This theoretical study investigates the nonlinear ionic current-voltage characteristics of nano-channels that have weakly overlapping electrical double layers. Numerical simulations as well as a 1-D mathematical model are developed to reveal that the electro-osmotic flow (EOF) interplays with the concentration-polarization process and depletes the ion concentration inside the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. As a result of the EOF-driven ion depletion, a limiting-conductance behavior is identified, which is intrinsically different from the classical limiting-current behavior

Conserved Regulation of p53 Network Dosage by MicroRNA–125b Occurs through Evolving miRNA–Target Gene Pairs

MicroRNAs regulate networks of genes to orchestrate cellular functions. MiR-125b, the vertebrate homologue of the Caenorhabditis elegans microRNA lin-4, has been implicated in the regulation of neural and hematopoietic stem cell homeostasis, analogous to how lin-4 regulates stem cells in C. elegans. Depending on the cell context, miR-125b has been proposed to regulate both apoptosis and proliferation. Because the p53 network is a central regulator of both apoptosis and proliferation, the dual roles of miR-125b raise the question of what genes in the p53 network might be regulated by miR-125b. By using a gain- and loss-of-function screen for miR-125b targets in humans, mice, and zebrafish and by validating these targets with the luciferase assay and a novel miRNA pull-down assay, we demonstrate that miR-125b directly represses 20 novel targets in the p53 network. These targets include both apoptosis regulators like Bak1, Igfbp3, Itch, Puma, Prkra, Tp53inp1, Tp53, Zac1, and also cell-cycle regulators like cyclin C, Cdc25c, Cdkn2c, Edn1, Ppp1ca, Sel1l, in the p53 network. We found that, although each miRNA–target pair was seldom conserved, miR-125b regulation of the p53 pathway is conserved at the network level. Our results lead us to propose that miR-125b buffers and fine-tunes p53 network activity by regulating the dose of both proliferative and apoptotic regulators, with implications for tissue stem cell homeostasis and oncogenesis

Modeling and Analysis of Pollution-free Agricultural Regulatory Based on Petri-net

Abstract: To carry out pollution-free agricultural products certification work is the important issue of people's daily lives. It is of great significance to construct the pollution-free agricultural regulatory system (PFARS) and achieve the office automation of the certification business. However, the PFARS contains much more steps in dispersion areas that it is very complex for business processes of E-PFAPC. In this paper, we not only provide the The results show that the PFARS system constructed by the workflow model can implement the business run automatically and own prefect performance

Modeling and Analysis of Pollution-Free Agricultural Regulatory Based on Petri-Net

International audienceTo carry out pollution-free agricultural products certification work is the important issue of people’s daily lives. It is of great significance to construct the pollution-free agricultural regulatory system (PFARS) and achieve the office automation of the certification business. However, the PFARS contains much more steps in dispersion areas that it is very complex for business processes of E-PFAPC. In this paper, we not only provide the method of modeling the PFARS with Petri Net, but also provide the improved method to analysis the Performance of the constructed workflow model. The model for the PFARS provides a more simply process management than original work method. The provided workflow model analysis method can effectively verify the performance of building model. The results show that the PFARS system constructed by the workflow model can implement the business run automatically and own prefect performance

Can We Preserve Biodiversity in Extremely Touristic Areas?

Aim: It is estimated that at most 10% of the populations of soil microarthropods have been explored and little is known about the drivers of the community composition. Noted the growing interest in using them as bioindicators, there is a need in understanding how communities respond to different disturbances. In this study, we investigated how microarthropods populations respond to anthropic pressure in two neighbouring Italian coastal areas: the natural reserve of Porto Caleri and the extremely touristic Albarella island. Method: We sampled 10 biotopes per area: 8 samples were taken along a transect from shore to forest across the Mediterranean dunal system, and the last 2 samples in unique site-specific non- matching biotopes. From each sample, edaphic microarthropods were extracted and their community analysed. Results: Statistical analysis revealed no significant differences in arthropod abundance, taxa richness, community composition, community diversity and QBS-ar index between the studied areas, suggesting that soil microarthropods are more dependent on the complexity of the ecosystem rather than on the level of anthropization. Conclusions: Natural habitats in Albarella island are extremely fragmented and eroded but scarcely mechanically disturbed and this has been revealed to be sufficient, in this site, for the preservation of the microarthropod community. This study suggests the importance, in artificial habitats, of the maintenance of some areas of preserved natural vegetation that act as hotspots for soil biodiversity. Further studies are needed to understand the minimum area necessary to preserve a vital community and the potential of spatial colonization of edaphic microarthropods

Design, synthesis, and biological evaluation of novel benzoyl diarylamine/ether derivatives as potential anti-HIV-1 agents

A series of benzoyl diarylamine/ether derivatives were designed, synthesized, and evaluated for their activity against human immunodeficiency virus (HIV) in MT-4 cells. Three compounds (3b, 5a, and 6a1) exhibited moderate activities against wild-type (wt) HIV-1 with EC50 values ranging from 11 to 56 μm. Among them, compound 5a was the most potent inhibitor with a novel chemical skeleton, affording a new lead compound for further molecular optimization. An enzyme assay was also implemented to confirm the binding target of the active compounds represented by 6a1. Molecular simulation studies on compound 5a, 6a1, and 7a4 were carried out to understand their binding mode with wt HIV-1 reverse transcriptase (RT) and provided useful information for further rational design of NNRTIs.status: publishe

Transport-Induced Inversion of Screening Ionic Charges in Nanochannels

This work reveals a counterintuitive but basic process of ionic screening in nanofluidic channels. Steady-state numerical simulations and mathematical analysis show that, under significant longitudinal ionic transport, the screening ionic charges can be locally inverted in the channels: their charge sign becomes the same as that of the channel surface charges. The process is identified to originate from the coupling of ionic electro-diffusion transport and junction two-dimensional electrostatics. This finding may expand our understanding of ionic screening and electrical double layers in nanochannels. Furthermore, the charge inversion process results in a body-force torque on channel fluids, which is a possible mechanism for vortex generation in the channels and their nonlinear current–voltage characteristics

Correction: Mo et al. Land Use, Microorganisms, and Soil Organic Carbon: Putting the Pieces Together. <i>Diversity</i> 2022, <i>14</i>, 638

The authors wish to make the following corrections to this paper [...