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We consider a second order non-autonomous evolution equation in a Hilbert space H u ′ ′ (t) + A u (t) + γ (t) u ′ (t) + ∇ F (u (t)) = 0 , where A is a self-adjoint and nonnegative operator on H with a nontrivial kernel, the nonlinear term ∇ F is the gradient of a differentiable function F : D (A 1 / 2) → R , and γ (t) is a damping coefficient, vanishing as t goes to infinity. We focus on a limit case γ (t) = α / t (with some α > 0), which turns out to be quite tricky to deal with. When α exceeds a critical value, we obtain the optimal decay rate of the solution of the equation, in terms of the exponent associated with F. Moreover, we present two examples to illustrate our theoretical results. [ABSTRACT FROM AUTHOR]

• The microstructure evolution of heat-treated SLM Al-Ni-Cu-Fe-Zr-Sc specimens was obtained. • The phase transformation of the heat-treated specimen was investigated. • The elemental composition of the bimodal microstructure was obtained. • The nanoprecipitation in the fine-grained region was investigated to clarify the precipitation mechanism. The novel selective laser melting (SLM) Al-Ni-Cu-Fe-Zr-Sc alloy has high temperature stability, but the segregation of the melting pool boundary limits its potential applications. Because conventional heat treatment with a solid solution at 530 °C is inappropriate for the SLM Al-Ni-Cu-Fe-Zr-Sc alloy, this study used hyper-high-temperature solid-solution treatment at three temperatures (560, 570, and 580 °C for 1 h) to investigate the evolution of the melting pool structure. An artificial aging treatment was applied at 175 °C for 6 h to investigate the precipitation mechanism. The results indicated that as-printed presented a bimodal microstructure consisting of a coarse-grained (CG) region and a fine-grained (FG) region. The hyper-high-temperature solid-solution treatment promoted the decomposition of the melting pool boundary and expansion of FG region. The FG region was composed of Ni-, Cu-, and Fe-rich equiaxed grains. After aging treatment, Al 9 Fe(Cu)Ni and Al 3 (Sc, Zr) nano-scale strengthening phases could be found in the FG region. The decomposition of the melting pool boundary, bimodal microstructure, and nano-scale phases can strengthen the matrix and increase hardness. In addition, the mechanism of element diffusion in melting pool was also explored to confirm that heat treatment can reduce material deterioration caused by boundary precipitation. These characteristics mitigate the disadvantages of the SLM Al-Ni-Cu-Fe-Zr-Sc alloy in terms of its strength directionality and establish its potential for use in aerospace applications. [ABSTRACT FROM AUTHOR]

Nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol), a sesquiterpene alcohol present in aromatic essential oils of numerous plants, has been reported to possess anticancer activity. The potential therapeutic effect of nerolidol on uterine fibroids (UF), the most common benign tumor of the uterus worldwide, is unknown. In this study, we examined the anti-UF potential of nerolidol in ELT3 cells, a rat leiomyoma cell line widely used as an in vitro model, to identify the potential therapeutic agents for UF. We observed that treatment with cis - or trans -nerolidol inhibited cell proliferation in a dose-dependent manner and induced cell cycle arrest in the G1 phase, which was accompanied by reduction in Akt phosphorylation and downregulation of cyclin D1, cyclin-dependent kinase 4 (CDK4), and CDK6 protein expression. The proliferation-inhibiting activity of nerolidol correlated with the generation of intracellular reactive oxygen species (ROS), which was suppressed by N-acetyl-l-cysteine, a ROS inhibitor. Nerolidol treatment also increased the percentage of cells for which tail moment could be calculated using an alkaline comet assay, and induced p-γH2AXser139 expression, which indicated induction of DNA damage. We also observed downregulation of ATM and its phosphorylation after nerolidol treatment; furthermore, treatment with KU-55933, an ATM kinase inhibitor, mimicked the inhibitory effects of nerolidol treatment on cell proliferation and Akt phosphorylation. In conclusion, nerolidol displayed anti-UF activity in a leiomyoma cell model via ROS-induced DNA damage and G1 phase cell cycle arrest by inhibiting the expression and activation of the ATM/Akt pathway. Our data suggests that nerolidol is a potential therapeutic agent for UF. [Display omitted] • Nerolidol induces G1 phase arrest to reduce the proliferation of rat leiomyoma cells. • The inhibitory effect of nerolidol depends on reactive oxygen species generation. • Nerolidol induces DNA damage in rat leiomyoma cells. • Nerolidol reduces the activation of ATM/Akt kinases. • Inhibition of ATM mimics the effect of nerolidol in leiomyoma cells. [ABSTRACT FROM AUTHOR]

• The stomatal distribution pattern of 90 plant species in Loess Plateau was studied. • Phylogeny affected stomatal density and distribution pattern to some extent. • Most stomatal patterns were similar, but there were some exceptions. • Stomatal density may affect stomatal distribution pattern. Stomata are the valves controlling carbon and water exchange between plant leaves and the atmosphere. Stomatal position changes throughout the whole growth of leaves, and the position is gradually fixed until the leaves mature, whether stomatal spatial distributions exhibit clear patterning remains unclear. In this study, we measured stomatal density and stomatal position of 90 widespread plants from the Loess Plateau, quantifying the spatial patterns of stomatal distribution using replicated spatial point pattern analysis. The results showed that the stomatal distribution pattern was similar in all plants except five species (Ginkgo biloba , Festuca glauca , Hemerocallis fulva , Hylotelephium spectabile and Kochia scoparia). Stomatal density, aggregation and uniform distribution were slightly affected by phylogeny and depended on spatial scale of analysis. At small spatial scales (0–60 μm), were regularly distributed but at large spatial scales (60–400 µm) they were randomly distributed. Stomatal density was negatively correlated (p < 0.001) with the proportion of randomly distributed and positively correlated (p < 0.001) with the proportion of stomatal aggregated distributed, and no significant effect on the proportion of stomatal uniform distribution. These results highlight the linkages between stomatal distribution and phylogeny, which may provide reference for future optimization of transpiration models. [ABSTRACT FROM AUTHOR]

Contamination by pathogens, such as bacteria, can irritate a wound and prevent its healing, which may affect the physical fitness of the infected person. As such, the development of more novel nano-biomaterials able to cope with the inflammatory reaction to bacterial infection during the wound healing process to accelerate wound healing is required. Herein, a halofuginone‑silver nano thermosensitive hydrogel (HTPM&AgNPs-gel) was prepared via a physical swelling method. HTPM&AgNPs-gel was characterized based on thermogravimetric analysis, differential scanning calorimetry, morphology, injectability, and rheological mechanics that reflected its exemplary nature. Moreover, HTPM&AgNPs-gel was further tested for its ability to facilitate healing of skin fibroblasts and exert antibacterial activity. Finally, HTPM&AgNPs-gel was tested for its capacity to accelerate general wound healing and treat bacterially induced wound damage. HTPM&AgNPs-gel appeared spherical under a transmission electron microscope and showed a grid structure under a scanning electron microscope. Additionally, HTPM&AgNPs-gel demonstrated excellent properties, including injectability, temperature-dependent swelling behavior, low loss at high temperatures, and appropriate rheological properties. Further, HTPM&AgNPs-gel was found to effectively promote healing of skin fibroblasts and inhibit the proliferation of Escherichia coli and Staphylococcus aureus. An evaluation of the wound healing efficacy demonstrated that HTPM&AgNPs-gel had a more pronounced ability to facilitate wound repair and antibacterial effects than HTPM-gel or AgNPs-gel alone, and exhibited ideal biocompatibility. Notably, HTPM&AgNPs-gel also inhibited inflammatory responses in the healing process. HTPM&AgNPs-gel exhibited antibacterial, anti-inflammatory, and scar repair features, which remarkably promoted wound healing. These findings indicated that HTPM&AgNPs-gel holds great clinical potential as a promising and valuable wound healing treatment. [Display omitted] • Halofuginone‑silver thermosensitive nanohydrogels (HTPM&AgNPs-gel) had excellent properties, including injectable, thermosensitive, favorable hemocompatibility, and a slow-release. • HTPM&AgNPs-gel exhibited excellent antibacterial and anti-inflammatory properties with scar removal compared with commercial thermosensitive nanohydrogels. • HTPM&AgNPs-gel effectively contributes to the wound-repair process and is a potential candidate bioactive wound dressing that may support full-thickness skin wound healing. [ABSTRACT FROM AUTHOR]