Platinum-based anticancer drugs, including cisplatin, carboplatin, oxaliplatin, nedaplatin, and lobaplatin, are heavily applied in chemotherapy regimens. However, the intrinsic or acquired resistance ...severely limit the clinical application of platinum-based treatment. The underlying mechanisms are incredibly complicated. Multiple transporters participate in the active transport of platinum-based antitumor agents, and the altered expression level, localization, or activity may severely decrease the cellular platinum accumulation. Detoxification components, which are commonly increasing in resistant tumor cells, can efficiently bind to platinum agents and prevent the formation of platinum-DNA adducts, but the adducts production is the determinant step for the cytotoxicity of platinum-based antitumor agents. Even if adequate adducts have formed, tumor cells still manage to survive through increased DNA repair processes or elevated apoptosis threshold. In addition, autophagy has a profound influence on platinum resistance. This review summarizes the critical participators of platinum resistance mechanisms mentioned above and highlights the most potential therapeutic targets or predicted markers. With a deeper understanding of the underlying resistance mechanisms, new solutions would be produced to extend the clinical application of platinum-based antitumor agents largely.
The waste shells of crustaceans such as shrimp and crab are valuable raw materials for the preparation of heterogeneous element self-doped porous carbon. Herein, a carapace-based in-situ N/O co-doped ...hierarchical porous carbon (HPC) for supercapacitor electrode material was prepared by a simple CO
2
activation method. Benefiting from the extraordinary microstructure and chemical composition of shrimp carapace, the unique “oversized-threaded pore-macropore-mesopore-micropore” HPC exhibited ideal electrochemical performance in a 6 mol/L KOH electrolyte solution, with higher energy density of 10.32 Wh/kg and power density of 5.05 kW/kg, respectively, making it a promising electrode material for supercapacitors. Furthermore, in order to make clear the formation mechanism of threaded hole HPC, the raw materials of the carapace were treated by decalcification and deproteinization, respectively. The results show that the natural stud-like calcium carbonate array with a unique triangular distribution in the shrimp carapace plays an important role as an in-situ template in the formation of hierarchical porous carbon, which offers the as-prepared porous carbon material with unique structure and excellent properties. This strategy provides the effective use of wasted biomass resources for energy storage systems.
Bio-based polymer materials having great potential due to the depletion of fossil-fuel resources have been applied as single-use and medicinal materials but their low thermomechanical resistance have ...limited wider applications. Here, ultrahigh thermoresistant bio-based terpolymers with a low dielectric constant, comprising polybenzimidazole and poly(benzoxazole-
random
-aramid), were prepared by a method involving stepwise polycondensation of three monomers, 3,4-diaminobenzoic acid for benzimidazoles, 3-amino-4-hydroxylbenzoic acid for benzoxazoles, and 4-aminobenzoic acid for aramids. For optimized monomer compositions, the obtained terpolymers exhibited dielectric constants lower than 3, and a 10% mass loss at approximately 760 °C which is a temperature higher than that for any other polymer material reported so far. The high thermal degradation temperatures of the prepared terpolymers were a result of the high interaction enthalpies of hydrogen bonding between imidazole rings in the polymer chains, which were obtained from density functional theory calculations using trimer models. Furthermore, the applicability of the prepared terpolymers as a wire-coating material for a simple motor insulation was demonstrated, indicating that it has significant potential to be used as a thermostable material with a low dielectric constant (
k
).
A stepwise polymerization of polybenzimidazole is adopted to synthesize terpolymers with block structure, their films exhibit a low dielectric constant and ultrahigh thermal resistance.
To study the extraction difficulty of lithium ions from various crystal planes of Li
2
TiO
3
, according to the first principle, four representative crystal surfaces of Li
2
TiO
3
(precursor), ...(-133), (-206), (002) and (-131), were selected to establish a model and to calculate the surface energy, bond length and population using Materials Studio 5.5 (MS 5.5). The results demonstrate that there is no direct relationship between the surface energy and the order of disappearance of the four diffraction peaks when lithium titanate is treated with hydrochloric acid, instead, the difficulty of Li
+
extraction from various crystal faces corresponds to the Li-O bond strength. Lithium ion is easy to remove from (-133) and (-206) due to the relatively weak Li-O bond strength. In contrast, Li
+
extraction requires a longer time for (002) and (-131).
Implants with antibiotic drug loaded bioactive coatings have been increasingly applied in orthopedic operations. Here we report the drug release behavior of gentamycin loaded chitosan/calcium ...phosphate coatings on titanium. Chitosan/calcium phosphate coatings with different component ratios and surface topographies were prepared by electrochemical deposition method. Our results showed that the drug release from these coatings was controlled by their component ratio and surface topography, and the former ratio played a more significant role. The present coatings could provide an effective way to create both good bioactivity and antibacterial activity.
•Nano-Li2TiO3 was synthesized with CH3COOLi and Ti(OC4H9)4 by the sol–gel process.•H2TiO3-lithium adsorbent was obtained by treating Li2TiO3 with HCl.•Langmuir and Freundlich models were used to ...analyze the adsorption process.•The adsorption performance of the obtained adsorbent was studied.
CH3COOLi and Ti(OC4H9)4 were employed as lithium and titanium sources, respectively to synthesize Li2TiO3 by the sol–gel process, followed by treating with hydrochloric acid to yield H2TiO3-lithium adsorbent. Various concentrations of LiOH and lithium sources were used as adsorption liquid to carry out adsorption experiment, the data from which were analyzed by Langmuir and Freundlich models. The results indicate that the optimal calcination temperature is 650°C, and Li2TiO3 with particle size 60–80nm is observed. The Li+ drawn out ratio from Li2TiO3 reaches 78.9%, and the dissolution of titanium ions can be as low as 0.07%. The protonated sample obtained has a lower basal spacing, while the crystal morphology is retained. The main factors affecting the adsorptive capacity are the Li+ concentration and pH in the liquid. The adsorption process of H2TiO3-lithium adsorbent can be seen as a process including surface adsorption and ion exchange. Compared with Langmuir model, Freundlich model is more suitable for describing the actual adsorption process.
The arginine-glycine-aspartic (RGD) acid peptide was grafted to the surface of apatite-wollastonite (AW) ceramic in an effort to improve its cell adhesion, proliferation and osteoinduction. RGD ...peptide was covalently immobilized onto the surface of AW ceramic via the synthetic cross linker AAPTS-E and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). The modified surfaces were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The chemical analysis indicated that RGD peptide had been immobilized onto the AW surface successfully. The growth of osteoblast-like cells (MG63) showed that modifying the AW surface with RGD peptide enhanced the cell adhesion and proliferation. And the histological evaluation of RGD-AW showed that the bone regeneration and remodeling process were significantly enhanced compared to the original AW ceramics after 2, 4 and 8 weeks implantation in rabbit’s femoral condyles.
Crushable ceramic foams are more suitable to be used as an arrestor material applied in engineered materials arresting system （EMAS） for airport runway for their properties of widely controllable ...strength, negligible crushing-rebounding behavior, durability, and chemically-inert composition, comparing with traditional concrete foams. The synthesis of ceramic foams adopted direct-foaming method and used an animal protein as foaming agent. Kaolin, talc powder and alumina were the main raw materials. Effects of the ratios of raw materials, calcination temperatures, heating rates, holding time, viscosities of potyvinyl alcohol （PVA） solution as well as the amounts of protein foaming agent and water on microscopic structure, densities, compressive strength and open porosities of ceramic foams were investigated systematically. The results indicate that ceramic foams with typical pore sizes 100-300 μm, open porosities from 73.1% to 91.5%, densities from 0.25 to 0.62 g.cm-3, compressive strength from 0.19 to 4.89 MPa, are obtained by properly adjusting the parameters mentioned above. And the mechanical strength meets the requirement for the EMAS for airport runway. In addition, good correlations are observed among compressive strength, open porosity, microscopic structure, and crystal phase. Furthermore, the possibility of producing the general dimensions of such aircraft arresting components with the proposed method was also discussed.
Decoupling the dependence on carbon emissions from achieving high-quality economic development is a paramount objective for China. However, the often-overlooked aspect is the carbon emissions ...generated through trade activities, which can lead to an overestimation of decoupling progress. Our study quantified and compared the decoupling status of production-based and consumption-based carbon emissions from economic growth in Guangdong from 2002 to 2017 from the perspective of inter-provincial embodied carbon flow, and further investigated its driving factors. The results reveal that consumption-based carbon emissions consistently surpass production-based emissions, although they exhibited a steady decline in recent years. As a significant contributor to embodied carbon emissions, Guangdong outsources a considerable portion of its emissions to less developed regions such as Liaoning and Guangxi by importing raw or intermediate products with lower value-added raw, while it exports service products to provinces like Beijing and Zhejiang. Decoupling analysis indicated that Guangdong is progressively moving towards an optimal state of "double decoupling", where both production and consumption-based carbon emissions are decreasing. This represents a departure from the previous scenario of "fake decoupling", characterized by a reduction in production-based carbon emissions but persistently high consumption-based emissions. Additionally, our structural decomposition analysis highlights the potential for reducing carbon emissions and enhancing decoupling by increasing the utilization of clean energy and optimizing the trade input structure. These findings underscore the importance of accounting for embodied carbon emissions in decoupling studies and offer valuable insights for achieving high-quality development.
•We compare the decoupling status of production and consumption-based emissions from GDP.•Multi-Regional Input-Output tables from 2002 to 2017 is used.•Guangdong outsources most of its emissions to less developed regions.•Guangdong achieves a double decoupling, where both production and consumption-based emissions are decreasing.•Increasing the utilization of clean energy and optimizing the trade input structure can enhancing decoupling.
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