Superelastic Graphene Aerogels Constructed by Structural Modulation for Piezoresistive Sensing

The microstructure is a critical factor in determining the macroscopic properties of aerogel materials and has a significant impact on their performance in various application scenarios. Here, drawing inspiration from the microstructure regulation of the bubble template, polyvinylpyrrolidone (PVP) was used to microscopically regulate graphene oxide nanosheets in the fabrication of the graphene aerogel (GA). Simultaneously, sodium dodecyl sulfate (SDS) foaming was employed as the bubble template to aid in the construction of PVP/SDS-GA (PSGA) with a hierarchical porous structure. Such an innovative structural blueprint inherently promotes a more even distribution of stress, thereby enhancing the compressive strength of the aerogel. The advanced architecture of PSGA enables rapid desiccation by using ambient pressure and elevated thermal methods, simplifying the fabrication process. PSGA possesses several remarkable characteristics: an ultralow density of 2.84 mg/cm3, a high electrical conductivity of 10 S/m, a superelasticity with an extreme strain of 99%, an outstanding fatigue resistance with the ability to withstand 10,000 cycles at 70% strain, and a high compressive strength of 0.66 MPa. In light of these characteristics, the piezoresistive sensor conceptualized using PSGA as a foundational substrate exhibited superior signal discernment capabilities

Oncogenic Functions of the Cancer-Testis Antigen SSX on the Proliferation, Survival, and Signaling Pathways of Cancer Cells

<div><p>SSX is a transcription factor with elusive oncogenic functions expressed in a variety of human tumors of epithelial and mesenchymal origin. It has raised substantial interest as a target for cancer therapy since it elicits humoral responses and displays restricted expression to cancer, spermatogonia and mesenchymal stem cells. Here, we investigated the oncogenic properties of SSX by employing a RNA interference to knock-down the endogenous expression of SSX in melanoma and osteosarcoma cell lines. Depletion of SSX expression resulted in reduced proliferation with cells accumulating in the G1 phase of the cell cycle. We found that the growth promoting and survival properties of SSX are mediated in part though modulation of MAPK/Erk and Wnt signaling pathways, since SSX silencing inhibited Erk-mediated signaling and transcription of cMYC and Akt-1. We also found that SSX forms a transient complex with β-catenin at the G1-S phase boundary resulting in the altered expression of β-catenin target genes such as E-cadherin, snail-2 and vimentin, involved in epithelial-mesenchymal transitions. Importantly the silencing of SSX expression in <i>in vivo</i> significantly impaired the growth of melanoma tumor xenografts. Tumor biopsies from SSX silenced tumors displayed reduced cyclin A staining, indicative of low proliferation and predominantly cycloplasmic β-catenin compared to SSX expressing tumors. The present study demonstrates a previously unknown function of SSX, that as an oncogene and as a tumor target for the development of novel anti-cancer drugs.</p></div

SSX is required for Erk mediated signalling.

<p>Western blot showing the expression of Erk1–2 and Akt-1 and their activated (phosphorylated) forms pAkt (Ser 473) and pErk (Thr202/Tyr204) in control shRNA and SSX-shRNA DFW cells. Cells were starved in serum free media for 36 hrs (0 h) and cell signalling was activated by the addition of serum into the media. Samples were collected at 10 and 30 minutes (10′ and 30′) and at 6 and 24 hours (6 h, 24 h) following serum stimulation. SSX expression was determined by immunoprecipitation (fl188 antibody) and western blot (N18 antibody) the later recognozing bands of approximately 22 and 14 kDa.</p

shRNA targeting of SSX in inhibit the growth of xenografts in SCID mice.

<p>A) DFW melanoma cells stably transfected with SSX-shRNA (SSXi) or with a control shRNA (SSXm) vector, expanded and xenografted in SCID mice. A) Tumor volume determined at the indicated times. B) Tumor volume at the end point of the experiment (21 days). C) Growth curves of xenografts from conditionally SSX-shRNA silenced DFW cells (SSX−) and control shRNA (SSX+) cells. Doxycycline was administered to all mice by subcutaneous insertion of a slow release pellet to mantain steady concentration of doxycycline (10 µM) for 21 days. D) Tumor volume at the end point of the experiment. E) Immunohistochemistry of the tumors visualized in the light microscope using 10x objective, inserts 63x magnification: hematoxillin (HTX), the proliferation marker (ki-67) and β-catenin (β-cat).</p

The conditional knock-down of SSX inhibits the proliferation, survival and cell cycle progression of the melanoma cell line DFW in vitro.

<p>A) Graphic representation of the shRNA sequence (complementary to SSX1 to SSX9) ligated into shRNA vectors for stable and doxycycline regulated shRNA expression (see material and methods). B) Western blot showing SSX expression in control-shRNA and SSX-shRNA transfected cells 24 hours after doxycycline addition to the culture medium. C) Cell colony quantification in control and SSX-shRNA transfected DFW cells grown in the presence of doxycycline for 8 days. D) Cell proliferation curves determined by counting the number of alive cells in control and SSX silence cultures using trypan blue staining. E) S-phase cell cycle progression determined by BrdU incorporation in a fluorescence activated cell sorter (FACS). F) Percentage of cells at G1, S and G2 phases of the cell cycle in control and SSX shRNA knocked down DFW cells over 96 hours period.</p

SSX2 is frequently expressed in melanoma lesions and derived cell lines but not in normal cells.

<p>SSX expression was analyzed by a nested RT-PCR method previously described using primers recognizing SSX1 to SSX 9 cDNA. Fresh biopsies were obtained from metastatic lesions of melanoma patients. The DFW melanoma cell line expressing high levels of SSX1 to SSX5 was used for RNAi studies. NHEM: normal human epithelial melanocytes, HDF: human diploid fibroblasts.</p

SSX interacts with β-catenin and transactivates TCF/β-catenin target genes.

<p><b>A</b>) DFW and Saos-2 cell lines were synchronized in G1/S by double thymidine blockade as indicated in material and methods (0 hrs), and released into normal medium containing FBS for 6 and 24 hrs. SSX was immunoprecipitated from protein extracts collected at the indicated time points using the rabbit anti SSX antibody (FL188, detecting SSX1–9). An equivalent amount of protein from G1/S blocked Saos-2 cells was immunoprecipitated with an irrelevant anti mouse (m) or ant-rabbit (r) antibody. The protein complex were electrophoresed in reducing conditions and blotted ether with goat anti SSX (N18) or mouse anti β-catenin antibodies. The total input levels of β-catenin are shown in the upper gel image. B) Activity of a TCF/Lef luciferase reporter in SSX silenced and control DFW and Saos-2 cells, 48 hours after transfection of siRNA molecules (n = 5). The activity of the TCF/Lef reporter in SSX silenced cells is relative to that of control cells ( = 1). C) Gene transcription associated with SSX expression in both Saos-2 and DFW cells, determinded by PCR arrays containing 84 genes associated with epithelial to mesenchymal transition (n = 5) and confirmed by Q-RT PCR in SSX silenced and control DFW and Saos-2 cells as described in material and methods. SSX was knocked down in Saous-2 or DFW cells using siRNA molecules or shRNA vectors as indicated. Cells were collected and RNA was isolated 6 ours after siRNA transfection or 6 hours after addition of doxycycline into the medium (conditionally shRNA). The loss of SSX expression following RNAi silencing was confirmed by western blot before each Q-RT-PCR array, as shown in the figure. Fold-Change [2∧(−Delta Delta Ct)] is the normalized gene expression [2∧(−Delta Ct)] in SSX silenced cells divided by the normalized gene expression in the control (SSX+) cells. Values less than one indicate a negative or down-regulation.</p

Fluorine Doping Strengthens the Lithium-Storage Properties of the Mn-Based Metal–Organic Framework

The electrochemical properties of the metal–organic framework (MOF)-based composite as electrode material can be significantly improved by means of partial destruction of the full coordination of linkers to metal ions and replacing with other small ions, which make metal centers become more accostable and consequently more effective for the lithiation/delithiation process. In this paper, F^– was chosen to replace some of the benzenedicarboxylate (BDC) linkers because of its better interaction with the Li⁺ than the oxide ion. What’s more, the formed M–F bond promotes the Li⁺ to transfer at the active material interface and protects the surface from HF attacking. The as-synthesized F-doped Mn-MOF electrode maintains a reversible capacity of 927 mA h g^–1 with capacity retention of 78.5% after 100 cycles at 100 mA g^–1 and also exhibits a high discharge capacity of 716 mA h g^–1 at 300 mA g^–1 and 620 mA h g^–1 at 500 mA g^–1 after 500 cycles. Even at 1000 mA g^–1, the electrode still maintains a high reversible capacity of 494 mA h g^–1 after 500 cycles as well as a Coulombic efficiency of nearly 100%, which is drastically increased compared with pure Mn-MOF material as expected

Synthesis of a PNIPAM-Based Composite Hydrogel and Its Multipurpose Applications in Piezoresistive and Temperature Sensing

Herein, a poly(N-isopropylacrylamide)-based conductive composite hydrogel system coenhanced by clay and polydopamine-modified MXene was synthesized to achieve strain and temperature sensibility simultaneously. The noncovalently cross-linked network via MXene, clay, and polymer chains endowed the synthesized hydrogel with excellent mechanical properties (tensile strength at a break of 117 kPa and elongation at a break of 1723%). This hydrogel also exhibits strong adhesion and good electrical conductivity (0.13 S/m). Regarding the sensing properties, its temperature sensitivity is 2.749 °C–1, while its strain detection limit is as low as 0.05%. Based on the unique characteristics of the prepared hydrogel, the as-assembled sensor can detect stress and temperature simultaneously, exhibiting great application potential in human physiological monitoring

Comparison of Sedimentary PAHs in the Rivers of Ammer (Germany) and Liangtan (China): Differences between Early- and Newly-Industrialized Countries

As a proxy to trace the impact of anthropogenic activity, sedimentary polycyclic aromatic hydrocarbons (PAHs) are compared between the early industrialized and newly industrialized countries of Germany and China, respectively. Surface sediment samples in the Ammer River of Germany and the Liangtan River of China were collected to compare concentration levels, distribution patterns, and diagnostic plots of sedimentary PAHs. Total concentrations of 16 PAHs in Ammer sediments were significantly higher by a factor of ∼4.5 than those in Liangtan. This contrast agrees with an extensive literature survey of PAH levels found in Chinese versus European sediments. Distribution patterns of PAHs were similar across sites in the Ammer River, whereas they were highly varied in the Liangtan River. Pyrogenic sources dominated in both cases. Strong correlations of the sum of 16 PAHs and PAH groups with TOC contents in the Liangtan River may indicate coemission of PAHs and TOC. Poor correlations of PAHs with TOC in the Ammer River indicate that other factors exert stronger influences. Sedimentary PAHs in the Ammer River are primarily attributed to input of diffuse sources or legacy pollution, while sediments in the Liangtan River are probably affected by ongoing point source emissions. Providing further evidence of a more prolonged anthropogenic influence are the elevated black carbon fractions in sedimentary TOC in the Ammer compared to the Liangtan. This implies that the Liangtan River, like others in newly industrialized regions, still has a chance to avoid legacy pollution of sediment which is widespread in the Ammer River and other European waterways