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Accurate analysis of microRNA (miRNA) is promising for elucidation of cancer processes and therapeutic effects. In this study, we reported a new target-activated, light-actuated three-dimensional (3D) DNA walker on gold nanoparticles for sensitive detection of miRNA using pyrene-incorporated DNAzyme analogues. In this design, the target miRNA activated the 3D DNA walker system to releases the walking arm. Then, under ultraviolet light irradiation, the pyrene DNAzyme on the walking arm would consecutively cleave the disulfide bonds of substrate strands and recover the fluorescence signal, thus achieving the amplified miRNA detection. The sophisticated design of the light-actuated 3D DNA walker was systematically investigated. Furthermore, this strategy could also be employed for miRNA analysis in serum samples with satisfactory reproducibility. Notably, the proposed light-actuated 3D DNA walker-based technique eliminated the need of enzymes, cofactors, and RNA backbones, thereby significantly improving the stability and efficiency. Overall, the light-actuated 3D DNA walker-based strategy enabled facile, sensitive, and specific detection of miRNA and provided new perspectives in diagnostics.

AlGaN/GaN Schottky barrier diode (SBD) temperature sensor with low turn-on voltage was fabricated by employing the recessed anode structure. This AlGaN/GaN SBD demonstrates good rectification in a broad temperature scope from 298 to 473 K. Compared with common planar diode, the recessed anode SBD shows a relatively lower turn-on voltage and better Schottky contact characteristics. The temperature-dependent forward voltage at a fixed current displays great linearity, contributing to a sensitivity of about 1.0 mV/K. The calculated sensitivities exhibit the downtrend by increasing current level, which is in agreement with the thermionic emission (TE) model. The recessed anode AlGaN/GaN SBDs show good potential in temperature sensor application.

This paper introduces adsorption processes with scaled sizes for post-combustion carbon capture, pre-combustion carbon capture, and direct air capture (DAC). Technical characteristics, separation performances, and operating energy consumptions of adsorption-based pilot plants for carbon capture are analyzed. Opportunities and challenges of adsorption-based carbon capture processes in future development are illustrated. Adsorption-based post-combustion carbon capture is a relatively mature technology, which can be applied to retrofitted power plants. However, in order to commercialize this technology, quantities of research and development resources are still needed. Researches on adsorption-based post-combustion carbon capture should focus on the following three aspects: (1) Low-temperature adsorbents with excellent CO2 working capacities, kinetics, and stabilities, (2) low energy consumption cycles using steam purge, and (3) contactors with low gas-solid mass transfer resistances. The warm gas clean-up technology based on pressure swing adsorption (PSA) is a research hotspot for pre-combustion carbon capture. At present, many warm gas clean-up pilot plants are being built worldwide, and in the meantime, some bottlenecks appear. First, the CO2 working capacities of elevated temperature adsorbents are still lower than those of low temperature adsorbents. The recently reported molten salt-promoted magnesium oxide achieves a very high working capacity through the bulk phase chemical absorption, but a carbon capture prototype needs to be established to verify its cyclic stability. Achieving both high purity and high recovery of warm gas clean-up consumes a large amount of high temperature steam. Although multi-train PSA configuration can reduce the energy consumption, it also increases the operating complexity and equipment investment. In addition to CO2, the removal of other impurities such as H2S, COS, HCl, and heavy metals in syngas/reforming gas should be considered. The sorption enhanced reforming with oxy-fuel regeneration process based on high temperature adsorbents can achieve CO2 enrichment in the regeneration reactor. However, pilot plants for this technology are currently lacking, and so detailed techno-economic analysis is still needed to assess its capture cost. Although DAC is a relatively new concept and is still in the early stage for large-scale commercial application, the synergy between DAC and conventional carbon capture technologies can mitigate climate change effects in the long run. The development of DAC technologies needs to pay special attention to the pressure drop problems. Novel gas-solid contactors using structural adsorbents can effectively reduce the power consumption of the fan. Steam purge under subatomospheric pressures reduces the regeneration temperature of DAC, and thus makes the utilization of renewable energy and industrial waste heat for regeneration becoming possible. When steam purge is used, the cyclic stability of the adsorbents should be concerned. For instance, polyamine impregnated adsorbents are prone to amine leakage in the presence of steam. Therefore, the development of hydrothermally stable DAC adsorbents is significantly important.

Direct air capture (DAC) is becoming a technically feasible negative emission technology; however, the fabrication of affordable adsorbents with large CO2 capacities, fast kinetics, and high sorption-desorption stability are of critical importance for the large-scale deployment of the DAC process. In this study, amine functionalized, aqueous miscible organic MgxAl-CO3 layered double hydroxide (LDH) nanosheets are used to efficiently and rapidly capture CO2 from ambient air. 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TRI) treatment of highly dispersed LDH nanosheets produces a sorbent exhibiting an impressive adsorption capacity of 1.05 mmol g−1 at 25°C when exposed to 400 ppm CO2, which is 30% higher than equivalent amine-functionalized SBA-15 supports. CO2 uptake reaches 70% of this maximum capacity within 30 min and is twice as fast as supported polyamines. The highly dispersed LDH nanosheets provide excellent thermal, hydrothermal, and chemical stability, with negligible performance degradation after 50 adsorption-desorption cycles.

The binding between the immune checkpoints, programmed cell death ligand 1 (PD-L1) and programmed cell death 1 (PD-1), compromises T-cell-mediated immune surveillance. Immune checkpoint therapy using immune checkpoint inhibitors (ICIs) to block PD-L1 on cancer cell membrane or PD-1 on activated T cell membrane can restore antitumor function of T cell. However, the intracellular expression of PD-L1 and its active redistribution to cancer cell membrane may impair the therapeutic benefits of ICIs. To address this issue, herein we develop a nanodrug (MS NPs) capable of reducing PD-L1 expression and enhancing antitumor effects. Methods: The nanodrug was self-assembled from immunoadjuvant metformin (Met, an old drug) and anticancer agent 7-ethyl-10-hydroxycamptothecin (SN38) via hydrogen bonds and electrostatic interactions. A series of experiments, including the characterization of MS NPs, the validation of MS NPs-mediated down-regulation of PD-L1 expression and in vitro therapeutic effect, the MS NPs-mediated in vivo chemo-immunotherapy and tumor metastasis inhibition were carried out. Results: Different from ICIs that conformationally block PD-L1 on cancer cell membrane, MS NPs directly reduced the PD-L1 level via metformin to achieve immunotherapy. Therefore, MS NPs showed enhanced chemo-immunotherapy effect than its counterparts. MS NPs were also effective in inhibiting tumor metastasis by remodeling the extracellular matrix and restoring immune surveillance. Additionally, no obvious toxicity was observed in major organs from MS NPs-treated mice and a high survival rate of mice was obtained after MS NPs treatment. Conclusion: We have designed nanodrug MS NPs by self-assembly of the immunoadjuvant Met and the anticancer agent SN38 for combined immunotherapy and chemotherapy. MS NPs might break the deadlock of antibody-based ICIs in immunotherapy, and repurposing old drug might provide a new perspective on the development of novel ICIs.

One reason for the slow development of adsorption-based carbon capture technologies is the inefficient fabrication of adsorbents with both promising adsorption performance and granular strength. In this work, an easy, low-cost, and environmentally friendly one-pot method is proposed to prepare structured adsorbents for post-combustion CO2 capture. Different from the traditional method that uses powdered silica gel as the support, branched polyethyleneimine (PEI) was mixed with colloidal silica and was then coated onto a ceramic fiber honeycomb monolith. Scanning electron microscopy (SEM) provided evidence that the amine molecules dispersed uniformly onto the porous silica films after vacuum drying. The optimal adsorption temperature, humidity, and PEI loading of the adsorbents were then determined using isotherms, adsorption rate curves, and breakthrough curves. The results showed that the 50 wt% PEI-impregnated silica sol had the highest capacity (1.719 mmol/g), which was comparable to that prepared with silica gel powders. On this basis, the manufacturing process of the structured adsorbents was optimized by referring to the capacity, kinetics, and mechanical strength. In addition, the use of the 80 wt% PEI soaking solution to soak the ceramic fiber honeycomb twice was recommended. The structured adsorbents exhibited capacities up to 1.025 mmol/g in simulated flue gas and had very stable performance in humid conditions, showing little degradation after 50 adsorption/desorption cycles

Decreased adsorption capacity and complicated synthetic procedures with expensive or toxic raw chemicals are two major challenges faced by physical adsorbents for carbon capture in highly humid flue gas. In this study, a novel core-shell composite using LiX with high CO2 adsorption capacity as core and superior hydrophobic ZIF-8 as shell is proposed. The overall synthesis process is conducted under ambient temperature and pressure by adopting deionized water as green solvent. Experimental results show that the adsorption performance of the core-shell structure is enhanced along with the improvement of hydrophobic performance in highly humid flue gas. The performance of ZIF-8 shells from monolayer to multilayers (up to three layers) are investigated. In particular, LiX@ZIF-8-I with single layer of ZIF-8 exhibit the highest CO2 adsorption capacity of 1.73 mmol/g in humid flue gas. The monolayered adsorbent not only exhibit superior hydrophobicity and CO2 adsorption capacity but also maintain excellent hydrothermal stability in humid flue gas over 50 adsorption/desorption cycles, which promote its application to practical in a green, energy-saving and economical way.