Self-Powered Photodetectors with High Stability Based on Se Paper/P3HT:Graphene Heterojunction.

Photodetectors based on selenium (Se) have attracted significant attention because of their outstanding optoelectronic characteristics, including their rapid reactivity and high photoconductivity. However, the poor responsivity of pure Se limits their further development. In this study, a novel Se-P/P3HT:G photodetector was designed and fabricated by combining an organic semiconductor made of poly-3-hexylthiophene mixed with graphene (P3HT:G) with self-supporting Se paper (Se-P) via spin-coating process.

Distributed model-free formation control of networked fully-actuated autonomous surface vehicles.

This paper presents a distributed constant bearing guidance and model-free disturbance rejection control method for formation tracking of autonomous surface vehicles subject to fully unknown kinetic model. First, a distributed constant bearing guidance law is designed at the kinematic level to achieve a consensus task. Then, by using an adaptive extended state observer (AESO) to estimate the total uncertainties and unknown input coefficients, a simplified model-free kinetic controller is designed based on a dynamic surface control (DSC) design.

The IPGA1-ANGUSTIFOLIA module regulates microtubule organisation and pavement cell shape in Arabidopsis.

Plant cells continuously experience mechanical stress resulting from the cell wall that bears internal turgor pressure. Cortical microtubules align with the predicted maximal tensile stress direction to guide cellulose biosynthesis and therefore results in cell wall reinforcement. We have previously identified Increased Petal Growth Anisotropy (IPGA1) as a putative microtubule-associated protein in Arabidopsis, but the function of IPGA1 remains unclear.

Two Complementary Signaling Pathways Depict Eukaryotic Chemotaxis: A Mechanochemical Coupling Model.

Many eukaryotic cells, including neutrophils and cells, are able to undergo correlated random migration in the absence of directional cues while reacting to shallow gradients of chemoattractants with exquisite precision. Although progress has been made with regard to molecular identities, it remains elusive how molecular mechanics are integrated with cell mechanics to initiate and manipulate cell motility. Here, we propose a two dimensional (2D) cell migration model wherein a multilayered dynamic seesaw mechanism is accompanied by a mechanical strain-based inhibition mechanism.

Asynchrony of ovule primordia initiation in .

Plant ovule initiation determines the maximum of ovule number and has a great impact on the seed number per fruit. The detailed processes of ovule initiation have not been accurately described, although two connected processes, gynoecium and ovule development, have been investigated. Here, we report that ovules initiate asynchronously.

Microtubule-Mediated Wall Anisotropy Contributes to Leaf Blade Flattening.

Plant organs can adopt a wide range of shapes, resulting from highly directional cell growth and divisions. We focus here on leaves and leaf-like organs in Arabidopsis and tomato, characterized by the formation of thin, flat laminae. Combining experimental approaches with 3D mechanical modeling, we provide evidence that leaf shape depends on cortical microtubule mediated cellulose deposition along the main predicted stress orientations, in particular, along the adaxial-abaxial axis in internal cell walls.

Epidermal restriction confers robustness to organ shapes.

The shape of comparable tissues and organs is consistent among individuals of a given species, but how this consistency or robustness is achieved remains an open question. The interaction between morphogenetic factors determines organ formation and subsequent shaping, which is ultimately a mechanical process. Using a computational approach, we show that the epidermal layer is essential for the robustness of organ geometry control.

Novel conjugates of podophyllotoxin and coumarin: Synthesis, cytotoxicities, cell cycle arrest, binding CT DNA and inhibition of Topo IIβ.

A series of conjugates of podophyllotoxin and coumarin were prepared using the click reaction, and their cytotoxicities against A549, HepG2, HeLa, and LoVo cells were evaluated. Among them, compound 14e exhibited the strongest cytotoxicities against these cancer cells with IC values of 4.9-17.

Computational model of wound healing: EGF secreted by fibroblasts promotes delayed re-epithelialization of epithelial keratinocytes.

It is widely agreed that keratinocyte migration plays a crucial role in wound re-epithelialization. Defects in this function contribute to wound reoccurrence causing significant clinical problems. Several in vitro studies have shown that the speed of migrating keratinocytes can be regulated by epidermal growth factor (EGF) which affects keratinocyte's integrin expression.

Mechanochemical modeling of neutrophil migration based on four signaling layers, integrin dynamics, and substrate stiffness.

Directional neutrophil migration during human immune responses is a highly coordinated process regulated by both biochemical and biomechanical environments. In this paper, we developed an integrative mathematical model of neutrophil migration using a lattice Boltzmann-particle method built in-house to solve the moving boundary problem with spatiotemporal regulation of biochemical components. The mechanical features of the cell cortex are modeled by a series of spring-connected nodes representing discrete cell-substrate adhesive sites.

Binding of intercellular adhesion molecule 1 to β-integrin regulates distinct cell adhesion processes on hepatic and cerebral endothelium.

Flowing polymorphonuclear neutrophils (PMNs) are forced to recruit toward inflamed tissue and adhere to vascular endothelial cells, which is primarily mediated by the binding of β-integrins to ICAM-1. This process is distinct among different organs such as liver and brain; however, the underlying kinetic and mechanical mechanisms regulating tissue-specific recruitment of PMNs remain unclear. Here, binding kinetics measurement showed that ICAM-1 on murine hepatic sinusoidal endothelial cells (LSECs) bound to lymphocyte function-associated antigen-1 (LFA-1) with higher on- and off-rates but lower effective affinity compared with macrophage-1 antigen (Mac-1), whereas ICAM-1 on cerebral endothelial cells (BMECs or bEnd.

Mechanical regulation of organ asymmetry in leaves.

How appendages, such as plant leaves or animal limbs, develop asymmetric shapes remains a fundamental question in biology. Although ongoing research has revealed the genetic regulation of organ pattern formation, how gene activity ultimately directs organ shape remains unclear. Here, we show that leaf dorsoventral (adaxial-abaxial) polarity signals lead to mechanical heterogeneity of the cell wall, related to the methyl-esterification of cell-wall pectins in tomato and Arabidopsis.

One-pot synthesis and biological evaluation of N-(aminosulfonyl)-4-podophyllotoxin carbamates as potential anticancer agents.

A series of N-(aminosulfonyl)-4-podophyllotoxin carbamates were synthesized via the Burgess-type intermediate, and their antiproliferative activities were evaluated. Most of them possessed more potent cytotoxic effects against four human tumor cell lines (HeLa, A-549, HCT-8 and HepG2) and less toxic to normal human fetal lung fibroblast WI-38 cells than etoposide. In particular, N-(morpholinosulfonyl)-4-podophyllotoxin carbamate (9) exhibited the most potent activity towards these four tumor cells with IC values in the range of 0.

Dynamic contributions of P- and E-selectins to β2-integrin-induced neutrophil transmigration.

Leukocyte transendothelial migration is a key step in their recruitment to sites of inflammation. However, synergic regulation of endothelium-expressed selectins on leukocyte transmigration remains unclear. In this study, an in vitro model was developed to investigate the dynamic contributions of P- and E-selectin to polymorphonuclear neutrophil (PMN) transmigration under static conditions.

Synthesis of hybrid 4-deoxypodophyllotoxin-5-fluorouracil compounds that inhibit cellular migration and induce cell cycle arrest.

A series of deoxypodophyllotoxin-5-fluorouracil hybrid compounds were synthesized, and their cytotoxic activity was evaluated using four human cancer cell lines (HeLa, A549, HCT-8, and HepG2) and the human normal cell line WI-38. The synthesized compounds exhibited greater cytotoxic activity in tumor cells and reduced toxicity in the normal cell line compared with the anticancer drug VP-16 and 5-FU. Additionally, the most potent of these compounds-4'-O-demethyl-4-deoxypodophyllotoxin-4'-yl 4-((6-(2-(5-fluorouracil-yl) acetamido) hexyl) amino)-4-oxobutanoate (compound 22)-induced cell-cycle arrest in the G2/M phase by regulating levels of cdc2, cyclinB1, and p-cdc2 in A549 cells.

Bidirectional molecular transport shapes cell polarization in a two-dimensional model of eukaryotic chemotaxis.

Chemotacting eukaryotic cells can sense shallow gradients of chemoattractants and respond by assuming an asymmetric shape with well-defined front and back regions. Such a striking polarization phenomenon is produced largely through the interconversions and interactions between several cellular components, including Rac GTPase (Rac), phosphoinositide 3-kinase (PI3K), tensin homology protein (PTEN), phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) and phosphatidylinositol (4,5)-bisphosphate (PI(4,5)P2). Here, we developed a mathematical model of cell polarization by exploring bidirectional molecular transport that arose from phosphoinositides (PIs) and Rac-mediated feedback loops.

Glial scar size, inhibitor concentration, and growth of regenerating axons after spinal cord transection.

A mathematical model has been formulated in accordance with cell chemotaxis and relevant experimental data. A three-dimensional lattice Boltzmann method was used for numerical simulation. The present study observed the effects of glial scar size and inhibitor concentration on regenerative axonal growth following spinal cord transection.