Metal-organic framework (MOF)-based materials for pyroptosis-mediated cancer therapy.

Pyroptosis is regarded as a promising strategy to modulate tumor immune microenvironments for anticancer therapy. Although pyroptosis inducers have been extensively explored in the biomedical field, their drug resistance, off-targeting capacity, and adverse effects do not fulfill the growing demands of therapy. Nowadays, metal-organic frameworks (MOFs) with unique structures and facile synthesis/functionalization characteristics have shown great potential in anticancer therapy. The flexible choices of metal ions and ligands endow MOFs with inherent anti-cancer efficiency, whereas the porous structures in MOFs make them ideal vehicles for delivering various chemodrug-based pyroptosis inducers. In this review, we provide the latest advances in MOF-based materials to evoke pyroptosis and give a brief but comprehensive review of the different types of MOFs for pyroptosis-mediated cancer therapy. Finally, we also discuss the current challenges of MOF-based pyroptosis inducers and their future prospects in this field.

Rationally Designed Benzobisthiadiazole-Based Covalent Organic Framework for High-Performance NIR-II Fluorescence Imaging-Guided Photodynamic Therapy.

Although being applied as photosensitizers for photodynamic therapy, covalent organic frameworks (COFs) fail the precise fluorescence imaging in vivo and phototherapy in deep-tissue, due to short excitation/emission wavelengths. Herein, this work proposes the first example of NIR-II emissive and benzobisthiadiazole-based COF-980. Comparing to its ligands, the structure of COF-980 can more efficiently reducing the energy gap (ΔES1-T1) between the excited state and the triplet state to enhance photodynamic therapy efficiency. Importantly, COF-980 demonstrates high photostability, good anti-diffusion property, superior reactive oxygen species (ROS) generation efficiency, promising imaging ability, and ROS production in deep tissue (≈8 mm). Surprisingly, COF-980 combined with laser irradiation could trigger larger amount of intracellular ROS to high efficiently induce cancer cell death. Notably, COF-980 NPs precisely enable PDT guided by NIR-II fluorescence imaging that effectively inhibit the 4T1 tumor growth with negligible adverse effects. This study provides a universal approach to developing long-wavelength emissive COFs and exploits its applications for biomedicine.

[Characteristics of Spatial and Temporal Evolution and Investigation of Air Pollution in Guangdong-Hong Kong-Macao Greater Bay Area Based on Ground-Space Observation Data].

The temporal and spatial distribution characteristics, evolution trend and potential climatic effects of air pollution in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) were analyzed on different time scales and spatial spaces, based on ground environment observation data from June 2014 to December 2018 and satellite remote sensing inversion products from 2000 to 2018. The results show that:① From the in-situ observed daily average concentration of PM2.5, good or mild to moderate pollution occurred in January, February, October, November, and December every year, and the rest of the time was excellent. ② Based on the annual average PM2.5 concentration obtained by satellite for the past 20 years, the spatial characteristics showed that the external radiation is centered on Guangzhou and Foshan. The time evolution shows the characteristics of an Ω shape, which increases gradually from 2000 to 2009, is highest in 2008, and then gradually decreases. ③ The monthly average aerosol optical thickness (AOT) value from the Multi-angle Imaging Spectro Radiometer satellite reversion every 10 years for a period (2000-2009 for a period, 2010-2018 for a period) was used to see the monthly variation. The monthly average AOT value in the first period was larger than that in the second period of the same month, the maximum value was in March and April, and the minimum value was in November and December. It is envisaged to draw a line along the north-south direction of the Pearl River Port, which basically shows that the AOT value in the west is greater than that in the east. ④ According to the observed daily average concentration data of O3-8h, the main concentration level of O3-8h in the GBA is excellent. The cities with good ozone concentration were most numerous in 2014, with five cities, and least in 2018, with only one city. The highest ozone concentration was in September, followed by June and November, and then May and July. In the past 20 years, the spatial distribution of the average concentration of O3 monitored by satellite remote sensing showed a characteristic Ω shape, increasing initially and then decreasing. The maximum value was in May, and the north-south boundary line appeared in space. ⑤ There is a good linear relationship between the interannual variation of monthly mean temperature and radiation, whereas the relationship between AOT and radiation cannot be described by a simple linear relationship.

[Research on the Pollution Characteristics and Causality of Haze-sand Air Pollution in Beijing in Spring].

From May 3 to 5, 2017, a special heavy pollution event occurred in Beijing. The meteorological conditions associated with the heavy pollution were relatively special, so the pollution forms and causes were studied. The general characteristics of this pollution event were obtained based on data from 35 environmental monitoring stations in Beijing. Matching characteristics of PM10 and PM2.5 concentrations with ground wind field data from automatic weather stations closest to the environmental monitoring stations were analyzed. By using MODIS and CALIPSO data, the spatial distribution in the horizontal and vertical directions was obtained, and the transport paths and pollutant categories of the pollution were elucidated. The causes of the pollution were analyzed by using ECMWF ERA-Interim data and Wind Profiler radar data. It was hoped that the special morphological characteristics and influencing factors of the pollution could be obtained by means of ground-space monitoring technology combined with meteorological conditions. The results showed that pollution characteristics and constraints could be better reflected by stereo observations and comprehensive analyses based on the above multi-source data. The pollution started abruptly and dropped sharply, and the pollution process lasted for about 30 hours. The whole process was divided into the following three stages:the first half, intermittent period, and second half. The concentrations of PM10 and PM2.5 were high throughout the whole process, reaching to 600-1000 µg·m-3 and 200-700 µg·m-3, respectively. The causes of pollution in the first half and second half and the resulting PM10 and PM2.5 concentrations were different in terms of the spatial distribution. In the first half, the dominant wind direction was northwest wind, and the wind speed was small. The spatial difference of PM10 concentrations was also small, with concentrations more than 800 µg·m-3; meanwhile, the spatial difference of PM2.5 concentrations was great. The concentration of PM2.5 was high in the south and urban areas, reaching to 600-700 µg·m-3, and it was low in other places, reaching to 350-500 µg·m-3. During the intermission, the wind direction in the lower layer shifted from northwest wind to south wind, and the upper layer maintained northwest wind. The concentration of PM10 in the south and urban area decreased obviously to 650 µg·m-3, and the concentration of PM10 in the north remained at 800 µg·m-3. At this time, the concentration of PM2.5 in the north even dropped to 200 µg·m-3. The dominant wind returned to northwest wind in the latter half, and the wind speed increased sharply. At this time, the spatial difference of PM2.5 concentrations was small and the concentration of PM2.5 at the same station was less than that in the former half, ranging from 250 to 500 µg·m-3. The PM10 concentrations returned to the level of 800 µg·m-3. The pollution process involved mixed pollution consisting of haze and sand. Under the influence of westerly winds, the main contribution to Beijing pollution was dust-type PM10, while under southerly flows, the contribution to Beijing pollution was not only dust, but also PM2.5. Heavy pollution was accompanied by high wind speeds. The vertical motion of the atmosphere converged at an altitude of about 2-3 km, which resulted in the accumulation of pollutants at this altitude.

Synergic effect of methanol and water on pine liquefaction.

Pine liquefaction (PL) and re-liquefaction of its liquefaction residues in sub- and supercritical methanol, water or methanol/water mixed solvents (MWMSs) was investigated. The results show that isometric MWMS has the highest synergic effect on PL. Moreover, the total yield of bio-oil (BO) and conversion from pine and its residue both liquefied in the MWMS were obvious higher than those from PL in methanol (water) and re-liquefaction of its residue in water (methanol), suggesting that the interaction between the two solvents is responsible for synergic effect. This approach facilitates understanding the mechanism for biomass liquefaction in mixed solvents and developing efficient utilization process of biomass.