Hydrothermal Synthesis of a Ce-Zr-Ti Mixed Oxide Catalyst with Enhanced Catalytic Performance for a NH3-SCR Reaction.

A series of mesoporous CeZrTiOx catalysts were prepared by a facile hydrothermal method. Compared with CeTiOx catalysts synthesized under the same conditions, the catalytic activity and anti-SO2 performance of the Ce1Zr1TiOx catalyst are greatly improved, and at the gas hourly space velocity (GHSV) of 60 000 h-1, the NOx removal efficiency is maintained at 90% in the temperature range of 290-500 °C. The catalytic effect of ZrO2 on the Ce-Ti catalyst NH3-SCR activity was elucidated through a series of characterizations. The results revealed that the doping of Zr could significantly improve and optimize the structure of Ce-Ti catalysts. At the same time, due to the doping of Zr, the synergistic effect between Ce and Zr in the CeZrTiOx catalyst can effectively increase oxygen mobility, total acid content, and surface adsorbed oxygen species and lead to a larger pore volume. In addition, the introduction of ZrO2 made the transformation of Ce4+ into Ce3+ more obvious, and the 2Ce4+ + Zr2+ ↔ 2Ce3+ + Zr4+ reaction greatly improved the reducibility of Ce1Zr1TiOx. Among them, the improvement of SCR performance and H2O/SO2 tolerance is due to the electronic interaction between Zr and Ce.

Two-step carrier-wave stitching method for aspheric and freeform surface measurement with a standard spherical interferometer.

Measurement of aspheric and freeform surfaces remains challenging due to the various shapes of the surface under test (SUT), especially when the SUT has a large aperture and strong deviation from the spherical surface. This paper proposes a two-step carrier-wave stitching method to enlarge the measurement bandwidth of a digital Moiré interferometry. Then, measurements of aspheric and freeform surfaces with a standard spherical interferometer without a phase-shifting mechanism are demonstrated. Experimental results with a root-mean-square repeatability of better than 1/200λ present good consistency to UA3P contact measurement results. Further simulation results with different residual wavefronts confirm measurement accuracies of peak-to-valley value of 10-3λ. The method is effective for large residual wavefronts and thus has potential for flexible measurement of aspheric and freeform surfaces.

Vertex radius of curvature error measurement of aspheric surface based on slope asphericity in partial compensation interferometry.

Vertex radius of curvature (VROC) is an important shape parameter used to determine the properties of an optical aspheric surface. Precise measurement of VROC error is critical for manufacturing and aligning optical aspheric surfaces. This paper introduces VROC error measurement of aspheric surface by using slope asphericity with partial compensation interferometry. VROC error and the decoupled surface figure error (SFE) can be simultaneously measured. Experimental results indicate that the method exhibits relative measurement accuracy of 0.01% when the nominal VROC is 889 mm, and the decoupled SFE error is λ/10 of the peak-to-valley value.

Aphanamixins A-F, acyclic diterpenoids from the stem bark of Aphanamixis polystachya.

Six new acyclic diterpenoids named Aphanamixins A-F (1-6), together with two known compounds of nemoralisin and nemoralisin C, were isolated from the stem bark of Aphanamixis polystachya (WALL) J. N. BARKER. Their structures were established through a comprehensive analysis of NMR spectroscopic data and high resolution mass spectrometric data. The absolute configurations of carbon stereocenters were determined by means of auxiliary chiral α-methoxy-α-(trifluoromethyl)phenylacetic acid (MTPA) derivatives and circular dichroism (CD), respectively. All the new isolates were tested for their antiproliferative activity against HepG2, AGS, MCF-7, and A-549 cancer cell lines and they exhibited weak cytotoxicities (IC50>10 µM). Moreover, we highlighted that the six new diterpenoids characterized by acyclic skeleton was rarely seen in nature.

Nanodrug constructed using dietary antioxidants for immunotherapy of metastatic tumors.

Immunogenic cell death (ICD) induced by reactive oxygen species (ROS) represents a particular form of tumor cell death for approaching the problem of low immunogenicity of tumors in immunotherapy, while the oxidative damage to normal cells of current ICD inducers hinders their clinical application. Herein, a new ICD inducer VC@cLAV constructed solely by dietary antioxidants, lipoic acid (LA) and vitamin C (VC), is developed, which could promote heavy intracellular ROS production in cancer cells for ICD induction while acting as an anti-oxidant in non-cancer cells for cytoprotection, and thus hold high biosafety. In vitro studies show that VC@cLAV induced a release of antigens and a maturation rate of DCs up to 56.5%, approaching the positive control (58.4%). In vivo combined with αPD-1, VC@cLAV showed excellent antitumor activity against both primary and distant metastatic tumors with an inhibition rate of 84.8% and 79.0% compared to 14.2% and 10.0% in the αPD-1 alone group. Notably, VC@cLAV established a long-term antitumor immune memory effect against tumor rechallenging. This study not only presents a new kind of ICD inducer but also provides an impetus for the development of dietary antioxidant-based cancer drugs.

Dietary Antioxidant-Constructed Nanodrugs Can High-Efficiently Kill Cancer Cells while Protecting Noncancer Cells.

Despite great advances, the development of cancer drugs that can efficiently kill cancer cells while protecting noncancer cells has not been achieved. By using only dietary antioxidants vitamin C (VC) and (R)-(+)-lipoic acid (LA), we herein develop a nanodrug VC@cLAV featuring the above function. After entering cells, cLAV dissociates into LA and DHLA (dihydrolipoic acid, reduced form of LA) and releases VC and DHA (dehydroascorbate, oxidized form of VC). In cancer cells, the two redox pairs recycle each other and dramatically promote the intracellular reactive oxygen species production to kill cancer cells at low doses comparable to cytotoxic drugs. Oppositely in noncancer cells, the LA/DHLA and VC/DHA pairs exert anti-oxidant action to actively protect the organism by preventing the normal cells from oxidative stress and repairing cells suffering from oxidative stress. When compared with the first-line cytotoxic drug, VC@cLAV displayed superior therapeutic outcomes yet without side effects in diverse tumor models including patient-derived xenograft (PDX). This drug with efficient cancer cell killing and noncancer cell protection represents a new cancer therapy.

Deep Drug Penetration of Nanodrug Aggregates at Tumor Tissues by Fast Extracellular Drug Release.

Herein, a new nanodrug of azobenzene-functionalized interfacial cross-linked reverse micelles (AICRM) with 5-fluorouracil loading (5-FU@AICRM) is reported. Upon irradiation with 530 nm light in water, the surface azobenzenes of the nanoparticles change from polar cis-conformation to nonpolar trans-conformation, resulting in the aggregation of 5-FU@AICRM within minutes. Simultaneously, the conformation change unlocks hydrophilic 5-FU with a strong water immigration propensity, allowing them to spray out from the AICRM quickly. This fast release ensures a thorough release of the drug, before the aggregates are internalized by adjacent cells, making it possible to achieve deep tissue penetration. A study of in vivo anticancer activity in A549 tumor-bearing nude mice shows that the tumor inhibition rate (TIR) of 5-FU@AICRM is up to ≈86.2%, 31.6% higher than that of group without green light irradiation and 20.7% higher than that of carmofur (CF, a hydrophobic analog of 5-FU)-loaded AICRM (CF@AICRM), in which CF is released slowly under light irradiation because of its hydrophobicity. Fast drug release upon nanodrug aggregation provides a good solution for balancing the contradiction of "aggregation and penetration" in tumor treatment with nanodrugs.