Search

Triple negative breast cancer (TNBC) is highly malignant and prone to recurrence and metastasis. Patients with TNBC usually have poor prognosis. Hence, it is urgent to develop new comprehensive treatments for TNBC. The combination of heat shock protein (HSP) inhibitor and the photothermal agent can reduce the temperature required to kill tumor cells, thus achieving mild-temperature photothermal therapy (PTT). Compared with traditional PTT, mild-temperature PTT not only decreases tumor thermoresistance introduced by the overexpression of HSP, but also reduces the damage to normal tissues. Meanwhile, Azo initiator 2,2-azobis[2-(2-imidazolin-2-yl) propane]-dihydroch-loride (AIPH) can be thermally decomposed to generate oxygen-independent free radicals. Herein, a new therapeutic multifunctional nanoplatform (M-17AAG-AIPH) by loading heat shock protein 90 (HSP90) inhibitor (17AAG) and AIPH incorporated into mesoporous polydopamine (MPDA) was successfully constructed for mild-temperature PTT combined with oxygen-independent cytotoxic free radicals against TNBC. Under 808 nm laser irradiation, the mild-temperature PTT arising from the combined effects of 17AAG and MPDA induced a rapid release and decomposition of AIPH, promoting the apoptosis of cancer cells in hypoxic microenvironments. Both in vitro and in vivo results showed that the designed nanoplatform can significantly inhibit tumor growth and provided an efficient new therapeutic strategy for TNBC. There is still an urgent need for new strategies for the treatment of triple negative breast cancer (TNBC). In this work, we successfully constructed a new therapeutic multifunctional nanoplatform (M-17AAG-AIPH) by co-carrying heat shock protein 90 (HSP90) inhibitor (17AAG) and AIPH on mesoporous polydopamine (MPDA). MPDA owned good biocompatibility and outstanding photothermal-conversion ability. The loading of 17AAG can reduce the heat resistance of tumor cells via specifically inhibiting the activity of HSP90, so as to achieve mild-temperature PTT. Meanwhile, 17AAG and MPDA mediated mild-temperature PTT promoted the decomposition of AIPH into oxygen-independent cytotoxic free radicals. Both in vitro and in vivo results showed that M-17AAG-AIPH can significantly inhibit tumor growth and provided an efficient new therapeutic strategy for TNBC. [Display omitted] [ABSTRACT FROM AUTHOR]

Intumescent fire-retardants (IFR) are widely applied in fire protection coatings of steel and wooden structures. The addition of inorganic fillers, such as layered ionic clays, can improve the fireproof performance of IFR coatings. However, a fundamental insight of how these filler materials synergistically interact with the IFR materials remains elusive. In this study, we address this fundamental knowledge gap by systematically investigating the synergy between the IFR fire protection coatings and the CaAlCO 3 -layer double hydroxide (LDH) or montmorillonite (MMT) fillers, which render substantially longer fire resistance (>20 min), reduced specific extinction area (by 54.7 and 44.1 m2 kg−2, respectively), and reduced heat release (by 0.9 and 0.7 MJ m−2, respectively). Combining experimental results and density functional theory calculations, we show for the first time that the superior fireproof performance of the MMT-IFR fire coating originates from the chemical modifications of the char layer by Si-doping. The chemical stabilisation of the silicon- and nitrogen-doped graphene (Si–N-G) structures improves the oxidation resistance of the char layer. Additionally, the formation of the Si–N-G structures with limited lattice deformation stabilised the porous morphology of the char layer, thereby promoting its heat-shielding performance. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the perovskite fluorescent nanocrystals (CsPbBr 3) were successfully synthesized and wrapped with SiO 2 shell, utilized for the assembly of solid-state detection strip capable of conveniently and specifically detection of aflatoxin B 1 (AFB 1). The SiO 2 coating aimed to enhance the stability of CsPbBr 3 nanocrystals. The resulting CsPbBr 3 @SiO 2 material exhibited remarkable fluorescence properties, and further self-assembled onto solid-state plate, generating AFB 1 -specific quenched fluorescence at a specific wavelength of 515 nm. When combined with the capture of AFB 1 by magnetic nanoparticles conjugated with aptamers (MNPs-Apt), it was achieved the good separation and specific detection of AFB 1 toxin in food matrices. The constructed fluorescent solid-state detection strip based on CsPbBr 3 @SiO 2 exhibited good response to AFB 1 toxin within a linear range of 0.1–100 ng mL−1 and an impressive detection limit as low as 0.053 ng mL−1. This presents a new strategy for the rapid screening and convenient detection of highly toxic AFB 1. • Fluorescent CsPbBr 3 nanocrystals coated with SiO 2 to improve the stability. • Self-assembly CsPbBr 3 @SiO 2 -based fluorescent solid-state strip for detecting AFB 1. • Remarkable linear response and sensitivity to AFB 1 with portable solid-state strip. • Good recovery and precision for magnetic aptasensing detection of AFB 1 in foods. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is an effective noninvasive therapeutic strategy that can convert oxygen to highly cytotoxic singlet oxygen (1O 2) through the co-localization of excitation light and photosensitizers. However, compromised by the hypoxic tumor microenvironment, the therapeutic efficacy of PDT is reduced seriously. Herein, to overcome tumor-associated hypoxia, and further achieve tumor-targeted synergistic chemotherapy/PDT/photothermal therapy (PTT), we have constructed a biodegradable oxygen-producing nanoplatform (named Ini@PM-HP), which was composed of the porous metal-organic framework (PCN-224(Mn)), the poly (ADP-ribose) polymerase (PARP) inhibitor (Iniparib), and the polydopamine-modified hyaluronic acid (HA-PDA). Since HA can specifically bind to the overexpressed HA receptors (cluster determinant 44, CD44) on tumor cell, Ini@PM-HP prefers to accumulate at the tumor site once injected intravenously. Then iniparib can be released in tumor environment (TME), thereby dysfunctioning DNA damage repair and promoting cell apoptosis. At the same time, the chelating of Mn and tetrakis(4-carboxyphenyl) porphyrin (Mn-TCPP) can generate O 2 in situ by reacting with endogenous H 2 O 2 , relieving the hypoxic TME and achieving enhanced PDT. Moreover, owing to the high photothermal conversion efficiency of PDA, PTT can be driven by the 808 nm laser irradiation. As systematically demonstrated in vitro and in vivo , this nanotherapeutic approach enables the combined therapy with great inhibition on tumor. Overall, the as-prepared nanoplatform provide a promising strategy to overcome tumor-associated hypoxia, and shows great potential for combination tumor therapy. A delicately designed biodegradable oxygen-producing nanoplatform Ini@PM-HP is constructed to achieve combination therapy of solid tumors. Taking advantage of the active-targeting, PTT, enhanced PDT and PARPi, this nanotherapeutic approach successfully enables the combined chemo/photothermal/photodynamic therapy with great inhibition of solid tumors. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • An IFR containing acid, carbon, and gas sources was prepared by in-situ calcination. • HRR, EHC, THR, and TOC of fabric with IFR were less than those without IFR. • Carbonization process and fireproof mechanism of IFR on fabric were studied. A novel macromolecular carbon-nitrogen-phosphorous (C-N-P) intumescent flame retardant (IFR) containing acid, carbon, and gas sources was prepared by calcining polyphosphate (APP), pentaerythritol (PER), and melamine (MEL) through the direct heating method. The carbonization and expansion behaviors of IFR were investigated by testing the products of IFR, using nuclear magnetic resonance, X-ray photoelectron spectroscopy, transmission electron microscope, and scanning electron microscopy, at 360 °C, 450 °C, and 600 °C. Conjugated double bonds polymerized the nitrogenous polyaromatic structures as polyphosphate decomposed into phosphoric acid and diphosphate. Noncombustible gases released by MEL increased the internal pressure of the viscoelastic materials to make it expand. At temperatures below 450 °C, MEL promotes the formation of nitrogenous polyaromatic structures in the material, thereby optimizing the IFR char layer structure. The heat release rate, effective heat combustion, total heat release, and total oxygen consume of the IFR coated fabric were less than those of an uncoated fabric by 18%, 5%, 16%, and 13%, respectively, reducing the risk of fire hazard. The foam char formed during the burning of an IFR coated fabric controls the fabric's oxidation process and prevents its shrinking. [ABSTRACT FROM AUTHOR]

• The addition of MgAlCO 3 -LDHs to the IFR coating effectively reduced the TSP and SPR from the cone calorimetry. • Thermal decomposition of MgAlCO3-LDHs could promote and catalyze esterification between APP and PER. • The C-N-P-MgAl coating could improve the thermal insulation performance of the char layer. MgAlCO 3 -layered double hydroxides (MgAlCO 3 -LDHs) were introduced in a waterborne intumescent fire retardant (IFR) with nano-coating containing ammonium polyphosphate (APP), pentaerythritol (PER), and melamine (MEL). The effects of MgAlCO 3 -LDHs were evaluated based on thermogravimetry (TG), differential thermal analysis (DTA), Fourier transform infrared spectroscopic analyses (FT-IR), X-ray power spectroscopy (XPS), scanning electron microscopy (SEM), fire performance test, and cone calorimetry. The 1.8 wt% of MgAlCO 3 -LDHs added to the IFR coating promoted the expansion of the char layer to improve its thermal insulation performance during the fire performance test. The results characterized by TG, DTA, XPS, and FT-IR revealed that MgAlCO 3 -LDHs enhanced the residual weight, the thermal stability and the oxidation resistance of the IFR coating. There was statistical evidence that the heat-shielding performance was reinforced by adding an appropriate amount of MgAlCO 3 -LDHs to the IFR coating to form uniform and compact foams in the char layer by using the digital image to process SEM images. The cone calorimetry revealed that a 46% reduction in total smoke production (or total smoke release) and a 25% decrease in the smoke production ratio were achieved in the coating with added MgAlCO 3 -LDHs compared with that without. It can be concluded that the addition of MgAlCO 3 -LDHs to IFR coating actively interacts with APP, PER, and MEL, thus improving the fire retardant properties of the coating. [ABSTRACT FROM AUTHOR]

LPS-induced injury in lung epithelial cells is a crucial part of the process of acute lung injury (ALI). The aim of this study is to explore whether Xanthorrhizol, a medicine that has antioxidant and anti-inflammatory activity, could mitigate the injury of lung epithelial cells caused by LPS. Mouse lung epithelial cell line (MLE-12 cells) were treated with LPS in the absence and presence of Xanthorrhizol. As a results, we observed that LPS could induce MLE-12 cells death, mitochondrial dysfunction, oxidative stress and inflammation, and activate MAPK signaling pathways. However, Xanthorrhizol mitigated the injury in MEL-12 caused by LPS by promoting cell viability and MDA, GSH production as well as inhibiting LDH release, mitochondria damage, IL-1β, IL-6 and TNF-α production and the phosphorylation levels of ERK, P38 and JNK. Our results indicated that Xanthorrhizol could protect lung epithelial cells from LPS-induced injury, more likely by inhibiting the phosphorylation of MAPK pathway related proteins. • Xanthorrhizol mitigates LPS-induced death in lung epithelial cells. • Xanthorrhizol alleviates the damage of mitochondria in lung epithelial cells induced by LPS. • Xanthorrhizol diminish oxidative stress and inflammation in lung epithelial cell caused by LPS. • Xanthorrhizol inhibits MAPK pathway activation in LPS-induced lung epithelial cell. [ABSTRACT FROM AUTHOR]

A unit cell-based design support system (UCBDSS) for composite structural design is introduced. A unit cell is defined as the smallest representative volumetric element to carry the information of composite constituent materials, heterogeneous structures, homogenized mechanical properties, and appropriate manufacturing processes. The database of various composite unit cells is organized to form a unit cell library (UCL). The UCBDSS can intelligently use the information from the UCL to simplify and automate the composite design process, to increase the design efficiency, and to facilitate the tailored composite structure design. The framework of the UCBDSS, its modules, the development of the UCL, the blackboard architecture for design control, and the UCBDSS working environment for Internet-based design are presented. [Copyright &y& Elsevier]

Development of effective methods for quantificationally characterizing the thermal resistance of the intumescent char layer of fired fire-retardant coating is of interest in many academic researches and industrial applications. In this work, a novel approach is proposed to calculate the thermal resistance of the intumescent char layer produced after the ultra-thin fire-retardant coating exposed to fire. A correlation was established based on the relative thermal resistance of the char layer to that of steel plate and the surface temperature at the back of the coated steel plate under steady-state heat transfer. The thermal resistance of the steel plate was obtained about 0.009 K·m2·W−1 by calculating the heat flux based on the radiation heat exchange involving three-surface enclosure model (flame, steel, and wall). The thermal resistances of the char layers without and with the layered double hydroxide (LDH) were 0.011 K·m2·W−1 and 0.013 K·m2·W−1, respectively. The results show that the external roughness and internal honeycomb structure can increase both the conductivity and the convective thermal resistances of the char layer to protect the steel structures. The porosity of the char layer is between 0.15 and 0.18, and its thermal conductivity is between 0.4 and 0.8 W·m−1·K−1 in the process of fire. Unlabelled Image • A novel method is proposed to calculate thermal resistance of intumescent char layer. • Thermal resistance is used to evaluate heat-shielding performance of char layer. • LDH improves external roughness and internal honeycomb structure of char layer. • Porosity of char layers is obtained to be 0.15–0.18 via SEM images processing. • Thermal conductivity of char layers is 0.4–0.8 W·m−1·K−1 in the process fire. [ABSTRACT FROM AUTHOR]

• Addition of MgAlCO 3 -LDHs and CaAlCO 3 -LDHs improved thermal insulation of IFR coating. • Metal ions from LDHs were chelated with carbon materials to form 3D reticular char. • LDHs can delay oxidation and improve degradation performance of char layers. MgAlCO 3 -layered double hydroxides (LDHs) and CaAlCO 3 -LDHs were respectively added as a synergistic agent to intumescent fire retardant (IFR) coatings. The 2.4 wt% of MgAlCO 3 -LDHs and the 6.7 wt% of CaAlCO 3 -LDHs were found to possess the best thermal insulation according to the fire performance tests. Further characterization by a cone calorimeter shows that the MgAlCO 3 -LDHs are superior to decreasing the specific extinction area of IFR coating, and the CaAlCO 3 -LDHs are advantageous in some other properties such as heat release rate, effective heat combustion and total heat release. Moreover, the X-ray diffraction (XRD) results infer that the flame retardant of char layer is primarily dependent on the amorphous structure formed after exposure to fire, the X-ray photoelectron spectroscopy (XPS) measurements of O 1s , C 1s , P 2p and N 1s reveal that the LDHs fillers suppress the oxidation of the IFR coating, and the Fourier transform infrared spectroscopy (FTIR) tests demonstrate that the LDHs protect the bridge frame structures. It is concluded that the LDHs can prevent the degradation and improve the thermal insulation of IFR coatings. [ABSTRACT FROM AUTHOR]

• An analysis method for SEM images of intumescent fire retardant char layers is proposed. • Foams in an intumescent fire retardant char layer are characterized quantificationally. • Appropriate addition of CaAlCO 3 -LDHs makes the char layer compact and uniform. • Unsatisfactory result image after color transformation is returned to object segmentation. A new characterization method is proposed to investigate the microscopic morphology of intumescent fire retardant (IFR) char layer observed under a scanning electron microscope (SEM). The method consists of object segmentation extracting the object, color transformation improving the recognition of subtle details, and statistical analysis obtaining the features (area, average, and standard deviation) of the object in the SEM images. There is a descending trend in the standard deviation of the foams with the increase of CaAlCO 3 -LDHs (layered double hydroxides) added to the coatings. Specifically, the number of the foams in the IFR coating with 5 wt% of CaAlCO 3 -LDHs addition is increased from 102 (that of the char layer without CaAlCO 3 -LDHs) to 123. Meanwhile, the standard deviation of the foams in the char layer is decreased from 6383.6 to 4304.5, demonstrating that an appropriate addition of CaAlCO 3 -LDHs can improve the foam quality of the IFR coating by making it more compact and uniform, and enhance the thermal insulation of the char layer covered on the substrate surface. [ABSTRACT FROM AUTHOR]

Copper oxide nanoparticles were prepared by the solvothermal method, and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption measurements. The as-prepared CuO nanoparticles functionalized QCM resonators were fabricated and explored for HCN sensing under varied humidity conditions. When the humidity of air containing HCN is the same as that of environmental air, a characteristic positive frequency shift of CuO nanoparticles functionalized QCM resonator is always observed towards HCN because of a reversible surface redox reaction between CuO and HCN. The sensitivity of CuO nanoparticles functionalized QCM resonators increases with increase of relative humidity in the range of 9-51%. These results provide an important guidance for further developing HCN gas sensors towards practical applications. [ABSTRACT FROM AUTHOR]

Abstract: A novel biosensor is developed based on immobilization of proteins on nanoflake-like SnS2 modified glass carbon electrode (GCE). With glucose oxidase (GOD) as a model, direct electrochemistry of the GOD/nanoflake-like SnS2 is studied. The prepared SnS2 has large surface area and can offer favorable microenvironment for facilitating the electron transfer between protein and electrode surface. The properties of GOD/SnS2 are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV), respectively. The immobilized enzyme on nanoflake-like SnS2 retains its native structure and bioactivity and exhibits a surface-controlled, reversible two-proton and two-electron transfer reaction with the apparent electron transfer rate constant (k s) of 3.68s−1. The proposed biosensor shows fast amperometric response (8s) to glucose with a wide linear range from 2.5×10−5 M to 1.1×10−3 M, a low detection limit of 1.0×10−5 M at signal-to-noise of 3 and good sensitivity (7.6±0.5mAM−1 cm−2). The resulting biosensor has acceptable operational stability, good reproducibility and excellent selectivity and can be successfully applied in the reagentless glucose sensing at −0.45V. It should be worthwhile noting that it opens a new avenue for fabricating excellent electrochemical biosensor. [Copyright &y& Elsevier]

Abstract: An energetic coordination compound [Cd(DAT)6](ClO4)2 has been synthesized by using 1,5-diaminotetrazole (DAT) as ligand and its structure has been characterized by applying X-ray single crystal diffraction, elemental analysis and FT-IR spectroscopy. The central cadmium(II) cation is coordinated by six N atoms from six DAT molecules to form a six-coordinated and distorted octahedral structure. Di-dimension layer structure was formed and the layers were linked together by the extensive intermolecular hydrogen bonds between DAT ligands and ClO4 − anions. Thermal decomposition mechanism of the title compound was predicted based on DSC, TG-DTG and FT-IR analyses results. The kinetic parameters of the first exothermic process of the title compound were studied by applying the Kissinger''s and Ozawa–Doyle''s methods. Sensitivity tests reveal that the title compound has sensitive nature. [Copyright &y& Elsevier]