Research Progress in the Use of Small Molecule Smac Mimetics in Combination Therapy of Cancer.

Inhibitors of Apoptosis Proteins (IAP) are inhibitors that can block programmed cell death, are expressed at high levels in various cancers, and are recognized as a therapeutic target for cancer therapy. In the past few years, several small molecule IAP protein inhibitors have been designed to mimic the endogenous IAP antagonist, but no IAP inhibitors have been approved for marketing worldwide. Previously, xevinapant has been awarded a breakthrough therapy designation by the FDA. In addition, a combination of Smac-mimetics and chemotherapeutic compounds has been reported to improve anticancer efficacy. According to the phase II clinical data, xevinapant has the potential to significantly enhance the standard therapy for patients with head and neck cancer, which is expected to be approved as an innovative therapy for cancer patients. Therefore, this paper briefly describes the mechanism of IAPs (AT-406, APG-1387, GDC- 0152, TL32711, and LCL161) as single or in combination for cancer treatment, their application status as well as the synthetic pathway, and explores the research prospects and challenges of IAPs antagonists in the tumor combination therapy, with the hope of providing strong insights into the further development of Smac mimics in tumor therapy.

Multispectral silicon-based photodetector with stacked PN junctions.

A multispectral silicon-based photodetector structure with stacked PN junctions is proposed in this study. The substrate layer of the proposed photodetector consists of four vertically stacked PN junction structures that contain four photodiodes. The designed structure achieves quantum efficiency of up to 70% and a response time of 5.1 × 10-8 s. The proposed photodetector has a simple structure, and the vertically stacked PN junction structure not only reduces the phenomenon of color aliasing, but also achieves multispectral absorption over the range from ultraviolet to visible light with high response speeds, which provides an effective way to perform high-quality imaging.

Two-dimensional heterostructures for photocatalytic CO2 reduction.

The photocatalysis conversion of CO2 into fuels has become an encouraging method to address climate and energy issues as a long-term solution. Single material suffers poor yield due to low light energy utilization and high recombination rate of photoinduced electron-hole pairs. It is an efficient approach to construct heterojunction through two or three materials to improve the photocatalytic performance. Recently, 2D-based heterojunction is getting popular for outstanding properties, such as special light collecting structure to enhance light harvest, intimate interface to facilitate charge transfer and separation, and large specific surface area to provide abundant reactive sites. Recently, some new 2D-based heterostructures materials (both structure and composition) have been developed with excellent performance. 2D materials exert structural and functional advantages in these fine composite photocatalysts. In this review, the literatures about the photocatalytic conversion of CO2 are mainly summarized based on overall structure, interface type and material type of 2D-based heterojunction, with special attention given to the preparation, characterization, structural advantages and reaction mechanism of novel 2D-based heterojunction. This work is in hope of offering a basis for designing improved composite photocatalyst for CO2 photoreduction.

High-performance subwavelength polarizer using "sandwich" structured substrates.

A subwavelength polarizer based on "sandwich" structured substrates is proposed in this study. The proposed subwavelength polarizer consists of three layers of subwavelength aluminum wires and dielectric substrate. The designed structure achieves an extinction ratio (ER) greater than 90 dB in a 400-800 nm visible wavelength region, achieving a maximum ER of 135 dB at 750 nm. Our results demonstrate significant improvements over the conventional single- and double-grid polarizers in terms of an ER and spectral range coverage. The proposed subwavelength polarizer in this paper has great potential in polarimetric imaging, liquid crystal display, and other optical fields.

Reversed selectivity of photocatalytic CO2 reduction over metallic Pt and Pt(II) oxide cocatalysts.

The chemical state of Pt in cocatalysts has a major influence on the activity and selectivity of the photocatalytic reduction of CO2; however, the underlying mechanism is unclear owing to the co-existence of different Pt chemical states and mutual transformation between them. In this study, PtO/TiO2 catalysts were prepared through photodeposition and Pt/TiO2 was prepared by the photoreduction of PtO/TiO2 to avoid interference arising from co-existing Pt forms and different loading amounts. These catalysts exhibited completely reversed selectivity for CO and CH4 production during CO2 photoreduction: PtO/TiO2 tended to produce CO (100%), whereas Pt/TiO2 favored the production of CH4 (66.6%). By combining experimental analysis and theoretical calculations, the difference in selectivity was ascribed to the different charge transfer/separation and CO/H adsorption properties of PtO/TiO2 and Pt/TiO2. Photoelectric and photoluminescence (PL) analysis showed that Pt was more advantageous to the photogenerated carrier separation compared with PtO, which was conducive to the multi-electron CH4 reduction reaction. Fourier transform-infrared spectroscopy, temperature-programmed desorption/temperature-programmed reduction, and density functional theory calculations indicated that the adsorption of CO and hydrogen on Pt was stronger than that on PtO, which favored the further reduction of CO to CH4. Based on the above results, a mechanism was proposed to explain the reversed selectivity of the photocatalytic reduction of CO2 over Pt/TiO2 and PtO/TiO2.

Effect of oxygen concentration on oxy-fuel combustion characteristic and interactions of coal gangue and pine sawdust.

Coal gangue is an inevitable coal waste from coal mine, which results in serious environmental problems. Oxy-fuel firing of coal waste and biomass waste is an alternative technology for efficient and clean utilization and CO2 reduction of coal waste. In this study, the oxy-fuel combustion characteristics and interactions of coal gangue and pine sawdust were investigated using thermogravimetric analysis, with a focus on the effect of oxygen concentration on interactions between coal gangue and pine sawdust during oxy-fuel combustion. The oxy-fuel combustion of pine sawdust had two obvious stages, including the release of volatile matter and the combustion of the remaining char, which differed from oxy-fuel combustion of coal gangue with one overlapped stage of devolatilization and char oxidation. Moreover, the addition of pine sawdust could improve the oxy-fuel combustion reactivity of coal gangue. The significant deviations between the experimental derivative thermogravimetric curves and theoretical derivative thermogravimetric curves for the blends indicated that interactions between coal gangue and pine sawdust had occurred in the temperature range of 400-600 °C. The interaction mechanism was primarily thermal effect between coal gangue and pine sawdust during oxy-fuel combustion. The oxygen concentration had a significant effect on the interactions between coal gangue and pine sawdust. The increase of oxygen concentration from 20% to 40% could improve interactions between coal gangue and pine sawdust obviously. However, relative small improvement of interactions was detected between coal gangue and pine sawdust when oxygen concentration was further increased from 60% to 80%. This was related to the difference of rate controlling factor for oxy-fuel combustion reaction under various oxygen concentrations.