Passage of exogeneous fine particles from the lung into the brain in humans and animals.

There are still significant knowledge gaps in understanding the intrusion and retention of exogeneous particles into the central nervous system (CNS). Here, we uncovered various exogeneous fine particles in human cerebrospinal fluids (CSFs) and identified the ambient environmental or occupational exposure sources of these particles, including commonly found particles (e.g., Fe- and Ca-containing ones) and other compositions that have not been reported previously (such as malayaite and anatase TiO2), by mapping their chemical and structural fingerprints. Furthermore, using mouse and in vitro models, we unveiled a possible translocation pathway of various inhaled fine particles from the lung to the brain through blood circulation (via dedicated biodistribution and mechanistic studies). Importantly, with the aid of isotope labeling, we obtained the retention kinetics of inhaled fine particles in mice, indicating a much slower clearance rate of localized exogenous particles from the brain than from other main metabolic organs. Collectively, our results provide a piece of evidence on the intrusion of exogeneous particles into the CNS and support the association between the inhalation of exogenous particles and their transport into the brain tissues. This work thus provides additional insights for the continued investigation of the adverse effects of air pollution on the brain.

Effect of Interlayer Anions on NiFe Layered Double Hydroxides for Catalytic Ozone Decomposition.

NiFe layered double hydroxides (NiFe-LDH) exhibited an outstanding performance and promising application potential for removing ozone. However, the effect of interlayer anions on ozone removal remains ambiguous. Here, a series of NiFe-LDH with different interlayer anions (F-, Cl-, Br-, NO3-, CO32-, and SO42-) were prepared to investigate the effect of the interlayer anion on ozone removal for the first time. It was found that the interlayer anions are a key factor affecting the water resistance of the NiFe-LDH catalyst under moist conditions. NiFe-LDH-CO32- exhibited the best water resistance, which was much better than that of NiFe-LDH containing other interlayer anions. The in situ DIRFTS demonstrates that the carbonates in the interlayer of NiFe-LDH-CO32- will undergo coordination changes through the interaction with water molecules under moist conditions, exposing new metal sites. As a result, the newly exposed metal sites could activate water molecules into hydroxyl groups that act as active sites for catalyzing ozone decomposition. This work provides a new insight into the interlayer anions of LDH, which is important for the design and development of LDH catalysts with excellent ozone removal properties.

Modulating the Electronic Structures of Pt on Pt/TiO2 Catalyst for Boosting Toluene Oxidation.

Surface hydroxyl groups commonly exist on the catalyst and present a significant role in the catalytic reaction. Considering the lack of systematical researches on the effect of the surface hydroxyl group on reactant molecule activation, the PtOx/TiO2 and PtOx-y(OH)y/TiO2 catalysts were constructed and studied for a comprehensive understanding of the roles of the surface hydroxyl group in the oxidation of volatiles organic compounds. The PtOx/TiO2 formed by a simple treatment with nitric acid presented greatly enhanced activity for toluene oxidation in which the turnover frequency of toluene oxidation on PtOx/TiO2 was around 14 times as high as that on PtOx-y(OH)y/TiO2. Experimental and theoretical results indicated that adsorption/activation of toluene and reactivity of oxygen atom on the catalyst determined the toluene oxidation on the catalyst. The removal of surface hydroxyl groups on PtOx promoted strong electronic coupling of the Pt 5d orbital in PtOx and C 2p orbital in toluene, facilitating the electron transfers from toluene to PtOx and subsequently the adsorption/activation of toluene. Additionally, the weak Pt-O bond promoted the activation of surface lattice oxygen, accelerating the deep oxidation of activated toluene. This study clarifies the inhibiting effect of surface hydroxyl groups on PtOx in toluene oxidation, providing a further understanding of hydrocarbon oxidation.

Boosting Photothermocatalytic Oxidation of Toluene Over Pt/N-TiO2: The Gear Effect of Light and Heat.

Photothermal catalysis is extremely promising for the removal of various indoor pollutants owing to its photothermal synergistic effect, while the low light utilization efficiency and unclear catalytic synergistic mechanism hinder its practical applications. Here, nitrogen atoms are introduced, and Pt nanoparticles are loaded on TiO2 to construct Pt/N-TiO2-H2, which exhibits 3.5-fold higher toluene conversion rate than the pure TiO2. Compared to both photocatalytic and thermocatalytic processes, Pt/N-TiO2-H2 exhibited remarkable performance and stability in the photothermocatalytic oxidation of toluene, achieving 98.4% conversion and 98.3% CO2 yield under a light intensity of 260 mW cm-2. Furthermore, Pt/N-TiO2-H2 demonstrated potential practical applicability in the photothermocatalytic elimination of various indoor volatile organic compounds. The synergistic effect occurs as thermocatalysis accelerates the accumulation of carboxylate species and the degradation of aldehyde species, while photocatalysis promotes the generation of aldehyde species and the consumption of carboxylate species. This ultimately enhances the photothermocatalytic process. The photothermal synergistic effect involves the specific conversion of intermediates through the interplay of light and heat, providing novel insights for the design of photothermocatalytic materials and the understanding of photothermal mechanisms.

Efficient porphyrin integrated UiO-66 probes for ratiometric fluorescence sensing of antibiotic residues in milk.

Dual-emissive fluorescence probes were designed by integrating porphyrin into the frameworks of UiO-66 for ratiometric fluorescence sensing of amoxicillin (AMX). Porphyrin integrated UiO-66 showed dual emission in the blue and red region. AMX resulted in the quenching of blue fluorescence component, attributable to the charge neutralization and hydrogen bonds induced energy transfer. AMX was detected using (F438/F654) as output signals. Two linear relationships were observed (from 10 to 1000 nM and 1 to 100 µM), with a limit of detection of 27 nM. The porphyrin integrated UiO-66 probe was used to detect AMX in practical samples. This work widens the road for the development of dual/multiple emissive fluorescence sensors for analytical applications, providing materials and theoretical supporting for food, environmental, and human safety.

A Unique Combination of Mn2+ and Aluminum Adjuvant Acted the Synergistic Effect.

Introduction: The development of combinatorial adjuvants is a promising strategy to boost vaccination efficiency. Accumulating evidence indicates that manganese exerts strong immunocompetence and will become an enormous potential adjuvant. Here, we described a novel combination of Mn2+ plus aluminum hydroxide (AH) adjuvant that significantly exhibited the synergistic immune effect. Methodology. Initially, IsdB3 proteins as the immune-dominant fragment of IsdB proteins derived from Staphylococcus aureus (S. aureus) were prepared. IsdB3 proteins were identified by western blotting. Furthermore, we immunized C57/B6 mice with IsdB3 proteins plus Mn2+ and AH adjuvant. After the second immunization, the proliferation of lymphocytes was measured by the cell counting kit-8 (CCK-8) and the level of IFN-γ, IL-4, IL-10, and IL-17 cytokine from spleen lymphocytes in mice and generation of the antibodies against IsdB3 in serum was detected with ELISA, and the protective immune response was assessed through S. aureus challenge. Results: IsdB3 proteins plus Mn2+ and AH obviously stimulated the proliferation of spleen lymphocytes and increased the secretion of IFN-γ, IL-4, IL-10, and IL-17 cytokine in mice, markedly enhanced the generation of the antibodies against IsdB3 in serum, observably decreased bacterial load in organs, and greatly improved the survival rate of mice. Conclusion: These data showed that the combination of Mn2+ and AH significantly acted a synergistic effect, reinforced the immunogenicity of IsdB3, and offered a new strategy to increase vaccine efficiency.

Ratiometric Fluorescence Assay for Pyrophosphate Based on Sulfur Nanodots Decorated Metal-Organic Frameworks.

Selective and sensitive detection of inorganic pyrophosphate (PPi) are of great significance both for clinical applications and fundamental research. In this work, a ratiometric fluorescent probe was developed by decorating a porphyrin-based metal-organic framework (PCN-224) with sulfur nanodots (S-dots). The red-fluorescence of PCN-224 was significantly promoted (more than 6-fold) by S-dots through inhibiting molecular motion of porphyrin ligand, which also provided active sites for the detection of Cu2+ and PPi. Cu2+ could selectively quench the red-fluorescence of PCN-224 through coordination with porphyrin ligand, and the competition reaction between PPi and Cu2+ resulted in the decomposing of coordination and recovery of red-fluorescence. The blue-fluorescence from S-dots was deemed as effective reference, which provided a built-in correction in complex environments. Based on these photophysical properties, a ratiometric fluorescence assay was developed for the quantitative detection of Cu2+ and PPi, with a limit of detection of 0.11 and 2.66 µM, respectively. The accuracy and practical applications of assays were also demonstrated by detection in tap water and human serum samples.

Synergistic Catalytic Oxidation of Typical Volatile Organic Compound Mixtures on Mn-Based Catalysts: Significant Promotion Effect and Reaction Mechanism.

The miscellaneous volatile organic compounds (VOCs) in industrial flue gas streams usually demonstrate significant mutual inhibition effects, and the behavior of a particular VOC in mixtures is not clear, which hinders the application of catalytic technology. This study examines the catalytic oxidation and mixing effects of representative VOCs in industrial exhausts, consisting of acetone (AC), ethyl acetate (EA), and toluene (Tol), on common Mn-based catalysts (e.g., MnO2, Mn2O3, LaMnO3, and Mn3O4) by means of intrinsic activity evaluation, coadsorption, VOC temperature-programmed oxidation, in situ diffuse reflectance infrared Fourier transform spectroscopy, and gas chromatography-mass spectrometry. The results showed no inhibiting effect on the conversion of these VOCs when combusted together; instead, a significant mutual promotion effect was found, especially on Tol destruction, with a sharp decrease in the Tol T50 from 214 to 158 °C on MnO2. It is proposed for the first time that the addition of AC/EA in Tol combustion leads to the generation of o/m-methyl phenol, which changes the rate-determining step of the ring-opening process, thus elevating the conversion of Tol together with AC and EA in the mixture at low temperatures.

Effects of SO2 on NH4NO3 Photolysis: The Role of Reducibility and Acidic Products.

Nitrate photolysis is a vital process in secondary NOx release into the atmosphere. The heterogeneous oxidation of SO2 due to nitrate photolysis has been widely reported, while the influence of SO2 on nitrate photolysis has rarely been investigated. In this study, the photolysis of nitrate on different substrates was investigated in the absence and presence of SO2. In the photolysis of NH4NO3 on the membrane without mineral oxides, NO, NO2, HONO, and NH3 decreased by 17.1, 6.0, 12.6, and 57.1% due to the presence of SO2, respectively. In the photolysis of NH4NO3 on the surface of mineral oxides, SO2 also exhibited an inhibitory effect on the production of NOx, HONO, and NH3 due to its reducibility and acidic products, while the increase in surface acidity due to the accumulation of abundant sulfate on TiO2 and MgO promoted the release of HONO. On the photoactive oxide TiO2, HSO3-, generated by the uptake of SO2, could compete for holes with nitrate to block nitrate photolysis. This study highlights the interaction between the heterogeneous oxidation of SO2 and nitrate photolysis and provides a new perspective on how SO2 affects the photolysis of nitrate absorbed on the photoactive oxides.

The role of NOx in Co-occurrence of O3 and PM2.5 pollution driven by wintertime east Asian monsoon in Hainan.

Clarifying the driving forces of O3 and fine particulate matter (PM2.5) co-pollution is important to perform their synergistic control. This work investigated the co-pollution of O3 and PM2.5 in Hainan Province using an observation-based model and explainable machine learning. The O3 and PM2.5 pollution that occurs in winter is affected by the wintertime East Asian Monsoon. The O3 formation shifts from a NOx-limited regime with a low O3 production rate (PO3) in the non-pollution season to a transition regime with a high PO3 in the pollution season due to an increase in NOx concentrations. Increased O3 and atmospheric oxidation capacity promote the conversion from gas-phase precursors to aerosols. Meanwhile, the high concentration of particulate nitrate favors HONO formation via photolysis, in turn facilitating O3 production. Machine learning reveals that NOx promotes O3 and PM2.5 co-pollution during the pollution period. The PO3 shows an upward trend at the observation site from 2018 to 2022 due to the inappropriate reduction of volatile organic compounds (VOCs) and NOx in the upwind areas. Our results suggest that a deep reduction of NOx should benefit both O3 and PM2.5 pollution control in Hainan and bring new insights into improving air quality in other regions of China in the future.

A superior catalyst for ozone decomposition: NiFe layered double hydroxide.

Ground-level ozone is harmful to human beings and ecosystems, while room-temperature catalytic decomposition is the most effective technology for ozone abatement. However, solving the deactivation of existing metal oxide catalysts was caused by oxygen-containing intermediates is challenging. Here, we successfully prepared a two-dimensional NiFe layered double hydroxide (NiFe-LDH) catalyst via a facile co-precipitation method, which exhibited stable and highly efficient performance of ozone decomposition under harsh operating conditions (high space velocity and humidity). The NiFe-LDH catalyst with Ni/Fe = 3 and crystallization time over 5 hr (named Ni3Fe-5) exhibited the best catalytic performance, which was well beyond that of most existing manganese-based oxide catalysts. Specifically, under relative humidity of 65% and space velocity of 840 L/(g·hr), Ni3Fe-5 showed ozone conversion of 89% and 76% for 40 ppmV of O3 within 6 and 168 hr at room-temperature, respectively. We demonstrated that the layered structure of NiFe-LDH played a decisive role in its outstanding catalytic performance in terms of both activity and water resistance. The LDH catalysts fundamentally avoids the deactivation caused by the occupancy of oxygen vacancies by oxygen-containing species (H2O, O-, and O2-) in manganese-based oxide. This study indicated the promising application potential of LDHs than manganese-based oxide catalysts in removal of gaseous ozone.

Improved and Reduced Performance of Cu- and Ni-Substituted Co3O4 Catalysts with Varying CoOh/CoTd and Co3+/Co2+ Ratios for the Complete Catalytic Oxidation of VOCs.

The Co3O4 spinel is one of the most promising transition metal oxide (TMO) catalysts for volatile organic compound (VOC) treatment. Substituting effects have usually been utilized to improve the catalytic performance of the Co3O4 spinel. In this study, Cu- and Ni-substituted Co3O4 catalysts derived from mixed metal-organic frameworks (MMOFs) retained similar spinel structures but exhibited improved and reduced performance for o-xylene oxidation, respectively. Physicochemical characterization and DFT calculations revealed that Cu and Ni substitution into the Co3O4 spinel varied the valence (Co3+/Co2+) and geometry (CoOh/CoTd) distributions of Co cations through different partial electron transfer and substitution sites. The higher Co3+/Co2+ and CoOh/CoTd ratios of the CuCo2O4 catalyst contributed to the superior reducibility and oxygen mobility, which facilitated the oxidation of intermediates at lower temperatures in the catalytic oxidation of o-xylene. Meanwhile, the NiCo2O4 catalyst with lower Co3+/Co2+ and CoOh/CoTd ratios could not completely oxidize intermediates under the same conditions due to inferior redox properties. Therefore, the CuCo2O4 catalyst showed superior catalytic activity and stability to the NiCo2O4 catalyst for the catalytic oxidation of o-xylene. This work provides insights into the synthesis of substituted Co3O4 catalysts from MMOFs and mechanism of substituting effects, which might guide the design of efficient TMO catalysts for VOC treatment.

Effect of Hydroxyl Groups on Metal Anchoring and Formaldehyde Oxidation Performance of Pt/Al2O3.

Pt/Al2O3 catalysts showing excellent activity and stability have been used in various reactions, including HCHO oxidation. Herein, we prepared Pt-Na/Al2O3 catalysts with a Pt content of 0.05 wt % to reveal the key factors determining the anchoring of Pt as well as the catalytic activity and mechanism of HCHO oxidation. Pt-Na/nano-Al2O3 (denoted as Pt-Na/nAl2O3) catalysts with 0.05 wt % Pt content could completely oxidize HCHO to CO2 at room temperature, which is the lowest Pt content used in HCHO catalytic oxidation to our knowledge. After Na addition, terminal hydroxyl groups (denoted as HO-µter) on nano-Al2O3 were transformed to doubly bridging hydroxyl groups between Na and Al (denoted as HO-µbri(Na-Al)), which atomically dispersed Pt species. Pt anchoring further promoted the regeneration of HO-µbri(Na-Al) by activating O2 and H2O, oxidizing HCHO to CO2 directly by the fast reaction step ([HCOO-] + [OH]a → CO2 + H2O). Our study revealed that the HO-µbri(Na-Al) synergistically generated by HO-µter and Na species provided anchoring sites for Pt species.

Layered Double Hydroxide Catalysts for Ozone Decomposition: The Synergic Role of M2+ and M3.

In previous work, we successfully prepared a NiFe-layered double hydroxide (LDH) with superior activity and stability for catalytic ozone decomposition, which fundamentally avoids deactivation under high-humidity conditions. However, the role of the metal elements (M2+ and M3+) in LDH catalysts is not clear. Here, LDH materials containing different metals (NiFe, NiAl, NiMn, CoFe, and MgFe) were prepared by a simple co-precipitation method. It was found that the LDHs containing Ni2+ exhibited catalytic performance far superior to that of Co2+ and Mg2+ for ozone elimination, and NiFe-LDH had the best activity and stability among LDH materials prepared in this study. The NiFe-LDH can maintain 78% catalytic activity within 144 h at room temperature, even under a relative humidity of 65% and a space velocity of 840 L·g-1·h-1. Physicochemical characterizations demonstrated that chemical stability in an oxidizing atmosphere and the synergic role of M2+ and M3+ ions are crucial. The result of density functional theory calculation showed that the synergic role of Ni2+ and Fe3+ weakens the interaction between O and H in the O-H bond, which effectively lowers the reaction barrier of ozone decomposition compared with MgFe-LDH.

miR-200a-3p promoted cell proliferation and metastasis by downregulating SOX17 in non-small cell lung cancer cells.

Lung cancer has high mortality and incidence rates in which non-small cell lung cancer (NSCLC) is the primary type of lung cancer that accounts for about 80%-85% of total patients. It has been demonstrated that microRNAs (miRNAs) are critical in the incidence and progression of tumors, while the role and inner mechanism of miR-200a-3p, one type of essential miRNAs, in NSCLC have yet to be revealed. Herein, we investigated the in vitro and vivo pro-/antiproliferative influence of miR-200a-3p on NSCLC cells and utilized bioinformatic programs to further predict the SOX17 gene as miR-200a-3p's potential target. A double luciferase reporter gene experiment was performed to confirm that miR-200a-3p interacts with the SOX17 3'-UTR region specifically. On the basis of the results of Western blot and quantitative reverse-transcription polymerase chain reaction (qRT-PCR), miR-200a-3p impacted the posttranscriptional levels of SOX17 rather than influencing its mRNA expression. In the end, we found that overexpressed SOX17 can reverse miR-200a-3p's impact on NSCLC cell proliferation and metastasis. Therefore, this study demonstrated that miR-200a-3p influences NSCLC cell proliferation and metastasis by modulating the levels of SOX17.

miR-125b-5p upregulation by TRIM28 induces cisplatin resistance in non-small cell lung cancer through CREB1 inhibition.

OBJECTIVE: miR-125b-5p plays an important role in the development of cancer and drug resistance. However, in cisplatin resistance of non-small cell lung cancer (NSCLC), the function and potential mechanism of miR-125b-5p is still unclear. The aim of this study was to investigate the role and molecular mechanism of miR-125b-5p in cisplatin resistance of NSCLC. METHODS: A GEO dataset (GSE168707) was analyzed to find high miR-125b-5p levels were associated with DDP resistance. miR-125b-5p expression levels were detected in A549 and A549/DDP cells via real-time quantitative RT-PCR (qRT-PCR). Luciferase reporter assays, western blots and mouse model xenografted were performed to identify CREB1 as a direct target gene of miR-125b-5p. Cell proliferation and apoptosis were also performed to identify whether miR-125b-5p upregulation by TRIM28 induces DDP resistance in NSCLC through CREB1 inhibition. RESULTS: In A549/DDP cells, miR-125b-5p expression was upregulated compared to A549 cells. Then miR-125b-5p was found to increase DDP resistance in NSCLC in vivo and in vitro by increasing cell proliferation and suppressing cell apoptosis. Bioinformatic analyses were used to search for gene which miR-125b-5p can target. We identified miR-125b-5p can regulate CREB1 via luciferase reporter assays, qRT-PCR and western blots. Cell proliferation and apoptosis were also performed to confirm miR-125b-5p could impact on CREB1 and induce the DDP resistance in NSCLC. Additionally, we used bioinformatic analyses to find tripartite motif-containing 28 (TRIM28) as a transcriptional enhance factor of miR-125b-5p. The expression of TRIM28 was upregulated in A549/DDP cells compared with that in A549 cells by qRT-PCR. Finally, we found TRIM28 could mediate DDP resistance through miR-125b-5p/CREB1 axis via cell proliferation, western blot and apoptosis assay. CONCLUSIONS: Overall, our findings demonstrated novel functions and mechanisms underlying DDP resistance in NSCLC through the TRIM28/miR-125b-5p/CREB1 axis. These may serve as novel therapeutic targets to improve the treatment efficacy using DDP for NSCLC in the future.

Generation and Release of OH Radicals from the Reaction of H2 O with O2 over Soot.

OH radicals in the air maintain the oxidizing power of the troposphere. A conventional view is that particulate matter (PM) in the atmosphere is a major sink of OH radicals, thereby lowering the oxidizing power of atmosphere in the event of high-level PM. By contrary, our joint experimental/theoretical study reveals a new mechanism for the generation of gaseous OH radicals by carbonaceous soot particles. We show that water and O2 react on carbonaceous surfaces and give rise to gaseous OH radicals under irradiation. With ample delocalized π electrons, carbonaceous surfaces enable the easy desorption of hydroxyl groups to produce gaseous OH radicals, evidenced by direct observation of the steady generation of OH radicals on a carbonaceous surface. Our results reveal a new chemical mechanism for the production of OH radicals.

[Analysis on the Characteristics of Quality Variation of National Medical Device Supervision and Inspection in 2020].

This study is based on the summary of the characteristics of quality variation of national medical device supervision and inspection in 2020. According to the results of the national medical device supervision and inspection through comparative analysis, this study puts forward suggestions on the medical device production and supervision measures for the post-marketing products, so as to further improve the level of the medical device and ensure the safety use of medical device.

Boosting the Dispersity of Metallic Ag Nanoparticles and Ozone Decomposition Performance of Ag-Mn Catalysts via Manganese Vacancy-Dependent Metal-Support Interactions.

Ozone (O3) removal has important implications for environmental protection and human health, and Ag-Mn catalysts have shown promising O3 decomposition. Catalysts with Ag supported on porous cube-like α-Mn2O3 (Ag/Mn-C) with high utilization of Ag were prepared by the impregnation method and showed excellent O3 decomposition activity. Physicochemical characterizations demonstrated that metallic Ag nanoparticles (Agn0) were mainly anchored on manganese vacancies, forming Ag-O-Mn bonds between Agn0 and α-Mn2O3-C. The abundant manganese vacancies of α-Mn2O3-C can lead to Agn0 with a smaller particle size and more uniform dispersion, thereby resulting in markedly enhanced O3 decomposition performance compared to Agn0 with a large particle size and uneven distribution on rod-like α-Mn2O3 (Ag/Mn-R). Under a relative humidity of 65% and a space velocity of 1,110,000 h-1, the conversion of 40 ppm O3 over the 2%Ag/Mn-C catalyst within 6 h (98%) at 30 °C was more than twice as high as that of the 2%Ag/Mn-R catalyst (42%). The study provides guidance for the design of highly efficient Ag-based catalysts and the understanding of the microstructure of supported catalysts.

Comprehensive Study about the Photolysis of Nitrates on Mineral Oxides.

Nitrates formed on mineral dust through heterogeneous reactions in high NOx areas can undergo photolysis to regenerate NOx and potentially interfere in the photochemistry in the downwind low NOx areas. However, little is known about such renoxification processes. In this study, photolysis of various nitrates on different mineral oxides was comprehensively investigated in a flow reactor and in situ diffuse reflectance Fourier-transform infrared spectroscopy (in situ DRIFTS). TiO2 was found much more reactive than Al2O3 and SiO2 with both NO2 and HONO as the two major photolysis products. The yields of NO2 and HONO depend on the cation basicity of the nitrate salts or the acidity of particles. As such, NH4NO3 is much more productive than other nitrates like Fe(NO3)3, Ca(NO3)2, and KNO3. SO2 and water vapor promote the photodegradation by increasing the surface acidity due to the photoinduced formation of H2SO4/sulfate and H+, respectively. O2 enables the photo-oxidation of NOx to regenerate nitrate and thus inhibits the NOx yield. Overall, our results demonstrated that the photolysis of nitrate can be accelerated under complex air pollution conditions, which are helpful for understanding the transformation of nitrate and the nitrogen cycle in the atmosphere.