Surface Hydrogen Bond-Induced Oxygen Vacancies of TiO2 for Two-Electron Molecular Oxygen Activation and Efficient NO Oxidation.

Defect engineering can provide a feasible approach to achieving ambient molecular oxygen activation. However, conventional surface defects (e.g., oxygen vacancies, OVs), featured with the coordinatively unsaturated metal sites, often favor the reduction of O2 to •O2- rather than O22- via two-electron transfer, hindering the efficient pollutant removal with high electron utilization. Herein, we demonstrate that this bottleneck can be well discharged by modulating the electronic structure of OVs via phosphorization. As a proof of concept, TiO2 nanoparticles are adopted as a model material for NaH2PO2 (HP) modification, in which HP induces the formation of OVs via weakening the Ti-O bonds through the hydrogen bond interactions. Additionally, the formed Ti-O-P covalent bond refines the electronic structure of OVs, which enables rapid electron transfer for two-electron molecular oxygen activation. As exemplified by NO oxidation, HP-modified TiO2 with abundant OVs achieved complete NO removal with high selectivity for benign nitrate, superior to that of pristine TiO2. This study highlights a promising approach to regulate the O2 activation via an electronic structure modulation and provides fresh insights into the rational design of a photocatalyst for environmental remediation.

Hydroxyl Radical-Mediated Efficient Photoelectrocatalytic NO Oxidation with Simultaneous Nitrate Storage Using A Flow Photoanode Reactor.

The selective conversion of dilute NO pollutant into low-toxic product and simultaneous storage of metabolic nitrogen for crop plants remains a great challenge from the perspective of waste management and sustainable chemistry. This study demonstrates that this bottleneck can be well tackled by refining the reactive oxygen species (ROS) on Ni-modified NH2 -UiO-66(Zr) (Ni@NU) using nickel foam (NF) as a three-dimensional (3D) substrate through a flow photoanode reactor via the gas-phase photoelectrocatalysis. By rationally refining the ROS to ⋅OH, Ni@NU/NF can rapidly eliminate 82 % of NO without releasing remarkable NO2 under a low bias voltage (0.3 V) and visible light irradiation. The abundant mesoporous pores on Ni@NU/NF are conducive to the diffusion and storage of the formed nitrate, which enables the progressive conversion NO into nitrate with selectivity over 99 % for long-term use. Through calculation, 90 % of NO could be recovered as the nitrate species, indicating that this state-of-the-art strategy can capture, enrich and recycle the pollutant N source from the atmosphere. This study offers a new perspective of NO pollutant treatment and sustainable nitrogen exploitation, which may possess great potential to the development of highly efficient air purification systems for industrial and indoor NOx control.

Design and realization of antireflection coatings for the visible and the infrared based on mesoporous SiO2 and SiO2-TiO2 hybrid materials.

Five-layer antireflective coating for the visible and the infrared has been successfully fabricated by a solgel route on quartz substrate. The quarter-half-quarter multilayer structure with two buffer layers is optimized by the optical admittance approach. Mesoporous SiO2 film templated by an ethylene oxide-propylene oxide-ethylene oxide triblock copolymer is used as the top layer, and SiO2-TiO2 hybrid films are employed as the other layers. The grazing incidence small-angle x-ray scattering results indicate the ordered mesopores in the low-index SiO2 film, as well as the homogeneity of the SiO2-TiO2 hybrid films. Transmittance spectra are fitted to obtain film thicknesses and refractive indices, providing the main technological parameters for theory designs. A short heat-treatment step followed by a shock cooling process is introduced to suppress crack formation in film stacks. The transmittance of the obtained five-layer antireflective coating exceeds 99% at 500-700 nm, and the maximum value in the infrared region is 97.84% at 1100 nm. This work is a beneficial attempt to fabricate antireflective coatings with multilayer structure through the soft solgel route.

PD-L1 expression in ovarian clear cell carcinoma using the 22C3 pharmDx assay.

BACKGROUND: Ovarian clear cell carcinoma (OCCC), well known for its chemoresistance to platinum-based chemotherapy, exhibited a good response in clinical trials of anti-PD-1/PD-L1 inhibitors. By assessing PD-L1 expression, we sought to determine the potential therapeutic benefit of PD-1/PD-L1 inhibitors in OCCC. METHODS AND RESULTS: The retrospective study included 152 individuals with OCCC between 2019 and 2022 at Peking Union Medical College Hospital. Paired tumors of primary versus recurrent lesions (17 pairs from 15 patients) or primary versus metastatic lesions (11 pairs from 9 patients) were also included. The 22C3 pharmDx assay and whole sections were used for PD-L1 immunohistochemical staining. Pathologists with experience in premarket clinical trials evaluated PD-L1 expression based on various diagnostic criteria (TPS 1%, CPS 1, or CPS 10). The number and percentage of positive PD-L1 cases were 34 (22.4%, TPS ≥ 1%) and 59 (38.8%, CPS ≥ 1), respectively. Thirty-three (21.7%) of the cases had high PD-L1 expression (CPS ≥ 10). Half of the platinum-resistant patients (11/22) were PD-L1 positive (CPS ≥ 1). In addition, positive PD-L1 expression (CPS ≥ 1) was related to clinicopathological characteristics that represented a worse prognosis, such as advanced stages, lymph node metastasis, and distant metastasis (p = 0.032, p < 0.001 and p = 0.003, separately). PD-L1 was expressed equally or more in the recurrent lesion compared with its matched primary lesion. CONCLUSIONS: In conclusion, anti-PD-1/PD-L1 inhibitors are a promising therapeutic choice for OCCC. For evaluation of PD-L1 expression, CPS is more recommended than TPS. Evaluation of recurrent lesion was still suitable and predictive when the primary tumor tissue was not available. Distant metastatic lesions can serve as alternative samples for PD-L1 evaluation, while usage of lymphatic metastatic lesions is not recommended.

Fluoroalkyl-grafted mesoporous silica antireflective films with enhanced stability in vacuum.

A new antireflective silica film with closed mesopores was successfully prepared for the optical elements used in vacuum of a high-power laser system. The ordered cagelike mesopores were formed with the direction of surfactant F127 and then closed by long-chain fluoroalkylsilane. The grazing incident x-ray diffraction and grazing incident small-angle x-ray scattering results indicated that the mesopores in film constructed a body-center cubic structure. The films exhibited excellent transmittance as high as 99.98% on quartz substrate. After a 1-month antipollution test with polydimethylsiloxane in vacuum, the decrease of transmittance was small as 0.02%. This film had a high laser-induced damage threshold of above 28 J/cm(2) at 1 ns laser pulse of 1053 nm wavelength.

Determination of thickness and optical constants of solgel derived polyvinylpyrrolidone/ZrO2 films from transmission spectra using different dispersion models.

Transmission measurements have been used to investigate the optical properties of polyvinylpyrrolidone (PVP)/ZrO(2) films synthesized by the solgel route. The optical constants of PVP/ZrO(2) films deposited on quartz substrates were determined by fitting transmission spectra in the wavelength range of 200-800 nm with the Tauc-Lorentz and Cody-Lorentz physical models. Combined with Urbach tail, both models give a good description of transmission data and reveal that refractive index of film slightly decreases with increasing PVP mass fraction. X-ray reflectivity (XRR) measurements were also performed on PVP/ZrO(2) films to complement the thicknesses. The value of film thickness, including interface information from transmission spectra, is consistent with that result obtained from XRR, indicating that fitting transmission spectrum is a high reliable optical characterization.