Enhanced Capillary Wicking through Hierarchically Porous Constructs Derived from Bijel Templates.

Liquid capillarity through porous media can be enhanced by a rational design of hierarchically porous constructs that suggest sufficiently large liquid pathways from an upper-level hierarchy as well as capillary pressure enabled by a lower hierarchy. Here, we demonstrate a material design strategy utilizing a new class of self-assembled soft materials, called bicontinuous interfacially jammed emulsion gels (bijels), to produce hierarchically porous copper, which enables the unique combination of unprecedented control over both macropores and mesopores in a regular, uniform, and continuous arrangement. The dynamic droplet topologies on the hierarchically copper pores prove the significant enhancement in liquid capillarity compared to homogeneous porous structures. The role of nanoscale morphology in liquid infiltration is further investigated through environmental scanning electron microscopy, in which wetting through the mesopores occurs at the beginning, followed by liquid transport through macropores. This understanding on capillary wicking will allow us to design better hierarchically porous media that can address performance breakthroughs in interfacial applications, ranging from battery electrodes, cell delivery in biomedical devices, to capillary-fed thermal management systems.

Computer vision-assisted investigation of boiling heat transfer on segmented nanowires with vertical wettability.

The boiling efficacy is intrinsically tethered to trade-offs between the desire for bubble nucleation and necessity of vapor removal. The solution to these competing demands requires the separation of bubble activity and liquid delivery, often achieved through surface engineering. In this study, we independently engineer bubble nucleation and departure mechanisms through the design of heterogeneous and segmented nanowires with dual wettability with the aim of pushing the limit of structure-enhanced boiling heat transfer performances. The demonstration of separating liquid and vapor pathways outperforms state-of-the-art hierarchical nanowires, in particular, at low heat flux regimes while maintaining equal performances at high heat fluxes. A deep-learning based computer vision framework realized the autonomous curation and extraction of hidden big data along with digitalized bubbles. The combined efforts of materials design, deep learning techniques, and data-driven approach shed light on the mechanistic relationship between vapor/liquid pathways, bubble statistics, and phase change performance.

A Deep Learning Perspective on Dropwise Condensation.

Condensation is ubiquitous in nature and industry. Heterogeneous condensation on surfaces is typified by the continuous cycle of droplet nucleation, growth, and departure. Central to the mechanistic understanding of the thermofluidic processes governing condensation is the rapid and high-fidelity extraction of interpretable physical descriptors from the highly transient droplet population. However, extracting quantifiable measures out of dynamic objects with conventional imaging technologies poses a challenge to researchers. Here, an intelligent vision-based framework is demonstrated that unites classical thermofluidic imaging techniques with deep learning to fundamentally address this challenge. The deep learning framework can autonomously harness physical descriptors and quantify thermal performance at extreme spatio-temporal resolutions of 300 nm and 200 ms, respectively. The data-centric analysis conclusively shows that contrary to classical understanding, the overall condensation performance is governed by a key tradeoff between heat transfer rate per individual droplet and droplet population density. The vision-based approach presents a powerful tool for the study of not only phase-change processes but also any nucleation-based process within and beyond the thermal science community through the harnessing of big data.

Boiling Heat Transfer with a Well-Ordered Microporous Architecture.

Boiling heat transfer through a porous medium offers an attractive combination of enormous liquid-vapor interfacial area and high bubble nucleation site density. In this work, we characterize the boiling performances of porous media by employing the well-ordered and highly interconnected architecture of inverse opals (IOs). The boiling characterization identifies hydrodynamic mechanisms through which structural characteristics affect the boiling performance of metallic microporous architecture by validating empirical measurements. The boiling performances can be optimized through the rational design of both the structural thicknesses and pore diameters of IOs, which demonstrate up to 336% enhancement in boiling heat-transfer coefficient (HTC) over smooth surfaces. The optimal HTC and critical heat flux occur at approximately 3-4 µm in porous structure thickness, which is manifested through the balance of liquid-vapor occupation within the spatial confinement of the IO structure. The optimization of boiling performances with varying pore diameters (0.3-1.0 µm) can be attributed to the hydraulic competitions between permeability and viscous resistance to liquid-vapor transport. This study unveils thermophysical understandings to enhance multiphase heat transfer in microporous media for ultrahigh heat flux thermal management.

Capillary Wicking in Hierarchically Textured Copper Nanowire Arrays.

Capillary wicking through homogeneous porous media remains challenging to simultaneously optimize due to the unique transport phenomena that occur at different length scales. This challenge may be overcome by introducing hierarchical porous media, which combine tailored morphologies across multiple length scales to design for the individual transport mechanisms. Here, we fabricate hierarchical nanowire arrays consisting of vertically aligned copper nanowires (∼100 to 1000 nm length scale) decorated with dense copper oxide nanostructures (∼10 to 100 nm length scale) to create unique property sets that include a large specific surface area, high rates of fluid delivery, and the structural flexibility of vertical arrays. These hierarchical nanowire arrays possess enhanced capillary wicking ( K/ Reff = 0.004-0.023 µm) by utilizing hemispreading and are advantageous as evaporation surfaces. With the advent and acceleration of flexible electronics technologies, we measure the capillary properties of our freestanding hierarchical nanowire arrays installed on curved surfaces and observe comparable fluid delivery to flat arrays, showing the difference of 10-20%. The degree of effective inter-nanowire pore and porosity is shown to govern the capillary performance parameters, thereby this study provides the design strategy for capillary wicking materials with unique and tailored combinations of thermofluidic properties.

Evaluation of UV Curing Properties of Mixture Systems with Differently Sized Monomers.

Ultraviolet (UV) curing is a photopolymerization technique resulting in a three-dimensional polymer network from monomers and oligomers after exposure to UV light, which is often used for fusion industry. However, shrinkage is an issue that needs to be resolved. Studies of single substances have been extensively conducted, but studies of mixture systems have not sufficiently been undertaken. In this study, we evaluate the shrinkage phenomenon by studying a monomer/monomer binary system and monomer/macromer composite systems. Shrinkage tends to increase when compounds varying in size are used. Similar to the shrinkage phenomenon, the curing rate is also relatively higher in such systems. These synergistic effects are evaluated to be due to the nano-porous effect, and vary with the composition ratio and material structure.

Mutant p53 promotes ovarian cancer cell adhesion to mesothelial cells via integrin ß4 and Akt signals.

Missense mutations in the TP53 gene resulting in the accumulation of mutant proteins are extremely common in advanced ovarian cancer, which is characterised by peritoneal metastasis. Attachment of cancer cells to the peritoneal mesothelium is regarded as an initial, key step for the metastatic spread of ovarian cancer. In the present study, we investigated the possible role of a p53 mutant in the mesothelial adhesion of ovarian cancer cells. We found that OVCAR-3 cells with the R248 TP53 mutation (p53(R248)) were more adhesive to mesothelial Met5A cells than were A2780 cells expressing wild-type p53. In addition, ectopic expression of p53(R248) in p53-null SKOV-3 cells significantly increased adhesion to Met5A cells. Knockdown of mutant p53 significantly compromised p53(R248)-induced cell adhesion to Met5A cells. Microarray analysis revealed that several adhesion-related genes, including integrin ß4, were markedly up-regulated, and certain signalling pathways, including PI3K/Akt, were activated in p53(R248) transfectants of SKOV-3 cells. Inhibition of integrin ß4 and Akt signalling using blocking antibody and the inhibitor LY294002, respectively, significantly attenuated p53(R248)-mediated ovarian cancer-mesothelial adhesion. These data suggest that the p53(R248) mutant endows ovarian cancer cells with increased adhesiveness and that integrin ß4 and Akt signalling are associated with the mutation-enhanced ovarian cancer-mesothelial cell adhesion.

Jaceosidin, isolated from dietary mugwort (Artemisia princeps), induces G2/M cell cycle arrest by inactivating cdc25C-cdc2 via ATM-Chk1/2 activation.

Jaceosidin, a flavonoid derived from Artemisia princeps (Japanese mugwort), has been shown to inhibit the growth of several human cancer cells, However, the exact mechanism for the cytotoxic effect of jaceosidin is not completely understood. In this study, we investigated the molecular mechanism involved in the antiproliferative effect of jaceosidin in human endometrial cancer cells. We demonstrated that jaceosidin is a more potent inhibitor of cell growth than cisplatin in human endometrial cancer cells. In contrast, jaceosidin-induced cytotoxicity in normal endometrial cells was lower than that observed for cisplatin. Jaceosidin induced G2/M phase cell cycle arrest and modulated the levels of cyclin B and p-Cdc2 in Hec1A cells. Knockdown of p21 using specific siRNAs partially abrogated jaceosidin-induced cell growth inhibition. Additional mechanistic studies revealed that jaceosidin treatment resulted in an increase in phosphorylation of Cdc25C and ATM-Chk1/2. Ku55933, an ATM inhibitor, reversed jaceosidin-induced cell growth inhibition, in part. Moreover, jaceosidin treatment resulted in phosphorylation of ERK, and pretreatment with the ERK inhibitor, PD98059, attenuated cell growth inhibition by jaceosidin. These data suggest that jaceosidin, isolated from Japanese mugwort, modulates the ERK/ATM/Chk1/2 pathway, leading to inactivation of the Cdc2-cyclin B1 complex, followed by G2/M cell cycle arrest in endometrial cancer cells.

Deer (Cervus elaphus) antler extract suppresses adhesion and migration of endometriotic cells and regulates MMP-2 and MMP-9 expression.

ETHNOPHARMACOLOGICAL RELEVANCE: Deer antler has been used for centuries as medicine for a wide range of health problems, including various women's diseases. However, there is a safety concern related to its use in hormone-sensitive conditions, such as breast cancer and endometriosis. In the present study, we investigated the effect of deer (Cervus elaphus) antler extract (DAE) on adhesion and migration of human endometriotic cells. MATERIALS AND METHODS: Adhesion, wound-healing, and transwell migration assays were performed in endometriotic cells 11Z and 12Z. Expression of matrix metalloproteinase (MMP)-2, MMP-9, TNF-α, and IL-6 were measured by real-time RT-PCR and Western blot analysis. RESULTS: DAE (50 and 100µg/ml) decreased the adhesion of 11Z and 12Z cells on peritoneal mesothelial Met5-A cells. Wound-healing and transwell migration assays revealed that DAE (50 and 100µg/ml) inhibited migration in 11Z and 12Z cells. It was further demonstrated that treatment with DAE (50 and 100µg/ml) significantly decreased the levels of MMP-2, MMP-9, TNF-α, and IL-6. CONCLUSIONS: These results indicate that DAE is a potential anti-endometriotic agent to inhibit the adhesion and migration of endometrial cells through the suppression of various related molecules.

Eupatilin, a dietary flavonoid, induces G2/M cell cycle arrest in human endometrial cancer cells.

This study is the first to investigate the antiproliferative effect of eupatilin in human endometrial cancer cells. Eupatilin, a naturally occurring flavonoid isolated from Artemisia princeps, has anti-inflammatory, anti-oxidative, and anti-tumor activities. In the present study, we investigated the potential effect of eupatilin on cell growth and its molecular mechanism of action in human endometrial cancer cells. Eupatilin was more potent than cisplatin in inhibiting cell viability in the human endometrial cancer cell lines Hec1A and KLE. Eupatilin showed relatively low cytotoxicity in normal human endometrial cells HES and HESC cells when compared to cisplatin. Eupatilin induced G2/M phase cell cycle arrest in a time- and dose-dependent manner, as indicated by flow cytometry analysis. In addition, treatment of Hec1A cells with eupatilin resulted in a significant increase in the expression of p21(WAF1/CIP1) and in the phosphorylation of Cdc25C and Cdc2. Knockdown of p21 using specific siRNAs significantly compromised eupatilin-induced cell growth inhibition. Interestingly, levels of mutant p53 in Hec1A cells decreased markedly upon treatment with eupatilin, and p53 siRNA significantly increased p21 expression. Moreover, eupatilin modulated the phosphorylation of protein kinases ERK1/2, Akt, ATM, and Chk2. These results suggest that eupatilin inhibits the growth of human endometrial cancer cells via G2/M phase cell cycle arrest through the up-regulation of p21 by the inhibition of mutant p53 and the activation of the ATM/Chk2/Cdc25C/Cdc2 checkpoint pathway.

Ultrastructural localization of Cryptosporidium parvum antigen using human patients sera.

The antigen location of Cryptosporidium parvum, which stimulates antibody formation in humans and animals, was investigated using infected human sera. Immuno-electron microscopy revealed that antigenicity-inducing humoral immunity was located at various developmental stages of parasites, including asexual, sexual stages, and oocysts. The amount of antigen-stimulating IgG antibodies was particularly high on the oocyst wall. The sporozoite surface was shown to give stimulation on IgG and IgM antibody formation. Trophozoites implicated the lowest antigenicity to humoral immunity, both IgG and IgM, by showing the least amount of gold labeling. Immunogold labeling also provided clues that antigens were presented to the host-cell cytoplasm via feeder organelles and host-parasite junctions.