This study, conducted in Agra, India, examined the mass concentrations, chemical compositions, and seasonal variations of submicron particles (PM₁). The concentrations of metals, water-soluble inorganic ions (WSIs) including anions (F^-, Cl^-, NO₃^-, SO₄^2-) and cations (Ca²⁺, K⁺, Mg²⁺, NH₄⁺, Na⁺), organic carbon (OC) and elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) in PM₁ extract were determined using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), Ion Chromatography, Thermogravimetric Analysis and Gas Chromatography-Mass Spectrometry (GC-MS) respectively. For morphological observation of PM₁ particles, Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray spectrometry (FESEM-EDS) was used. The annual average concentration of PM₁ was 82.9 ± 33.4 μg/m³, which exceeds the World Health Organisation's (WHO) safe limit for PM_2.5 of 5 μg/m³ by a factor of 17. The PM₁ mass composition included metals (31 %), WSIs (28 %), OC and EC (9.8 %), and PAHs (0.4 %). Winter recorded the highest PM₁ concentration (96.1 ± 25.8 μg/m³), followed by post-monsoon, summer, and monsoon seasons. The average concentration of PAHs was 364.6 ± 226.6 ng/m³. Positive Matrix Factorization (PMF) identified traffic, emissions from biomass/coal and wood combustion, industrial/stationary sources, and secondary aerosols as potential contributors. The Ames test revealed the presence of frameshift mutations and base pair substitutions, especially in winter and post-monsoon. Additionally, PM₁ exhibited cytotoxic effects on V-79 cells, with heightened toxicity during winter and prolonged exposure in other seasons. This study underscores the urgent need to address local emission sources and establish regulatory standards for PM₁ in urban areas.

2024-08-20·ACS Macro Letters

Photochemical [2 + 2] Cycloaddition Enables the Synthesis of Highly Thermally Stable and Acid/Base-Resistant Polyesters from a Nonpolymerizable α,β-Conjugated Valerolactone

Article

作者: Yu, Lefei ; Yang, Chun ; Bi, Cheng-Ao ; Wu, Xiao-Tong ; Du, Fu-Sheng ; Li, Zi-Chen

We report a simple strategy to transform a nonpolymerizable six-membered α,β-conjugated lactone, 5,6-dihydro-2H-pyran-2-one (DPO), into polymerizable bicyclic lactones via photochemical [2 + 2] cycloaddition. Two bicyclic lactones, M1 and M2, were obtained by the photochemical [2 + 2] cycloaddition of tetramethylethylene and DPO. Ring-opening polymerization (ROP) of M1 and M2 catalyzed by diphenyl phosphate (DPP), La[N(SiMe₃)₂]₃, and 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris (dimethylamino) phosphoranylide-namino]-2λ⁵, 4λ⁵-catenadi(phosphazene) (^tBu-P₄) were conducted. M1 is highly polymerizable, either DPP or La[N(SiMe₃)₂]₃ could catalyze its living ROP under mild conditions, affording the well-defined PM1 with a predictable molar mass and low dispersity. M2 could only be polymerized with ^tBu-P₄ as the catalyst, also generating the same polymer PM1. PM1 has high thermal stability, with a T_d,5% being up to 376 °C. Ring-opening copolymerization (ROcP) of M1 and δ-valerolactone (δ-VL) catalyzed by La[N(SiMe₃)₂]₃ afforded a series of random copolymers with enhanced thermal stabilities. Both PM1 and the copolymer containing 10 mol % M1 exhibited excellent resistance to acidic and basic hydrolysis. Our results demonstrate that direct photochemical [2 + 2] cycloaddition of α,β-conjugated valerolactone is not only a strategy to tune its polymerizability, but also allows for the synthesis of highly thermally stable aliphatic polyesters, inaccessible by other methods.

2024-04-01·Toxicology and Applied Pharmacology

Redox-activity and in vitro effects of regional atmospheric aerosol pollution: Seasonal differences and correlation between oxidative potential and in vitro toxicity of PM1

Article

作者: Tarallo, Naima ; Valentini, Sara ; Frezzini, Maria Agostina ; Canepari, Silvia ; Crova, Federica ; Costabile, Francesca ; Marinovich, Marina ; Paglione, Marco ; Rinaldi, Matteo ; Decesari, Stefano ; Melzi, Gloria ; Iulini, Martina ; Nozza, Emma ; Massimi, Lorenzo ; Corsini, Emanuela ; Vecchi, Roberta ; Valli, Gianluigi

Particulate Matter (PM) is a complex and heterogeneous mixture of atmospheric particles recognized as a threat to human health. Oxidative Potential (OP) measurement is a promising and integrative method for estimating PM-induced health impacts since it is recognized as more closely associated with adverse health effects than ordinarily used PM mass concentrations. OP measurements could be introduced in the air quality monitoring, along with the parameters currently evaluated. PM deposition in the lungs induces oxidative stress, inflammation, and DNA damage. The study aimed to compare the OP measurements with toxicological effects on BEAS-2B and THP-1 cells of winter and summer PM₁ collected in the Po Valley (Italy) during 2021. PM₁ was extracted in deionized water by mechanical agitation and tested for OP and, in parallel, used to treat cells. Cytotoxicity, genotoxicity, oxidative stress, and inflammatory responses were assessed by MTT test, DCFH-DA assay, micronucleus, γ-H2AX, comet assay modified with endonucleases, ELISA, and Real-Time PCR. The evaluation of OP was performed by applying three different assays: dithiothreitol (OP^DTT), ascorbic acid (OP^AA), and 2',7'-dichlorofluorescein (OP^DCFH), in addition, the reducing potential was also analysed (RP^DPPH). Seasonal differences were detected in all the parameters investigated. The amount of DNA damage detected with the Comet assay and ROS formation highlights the presence of oxidative damage both in winter and in summer samples, while DNA damage (micronucleus) and genes regulation were mainly detected in winter samples. A positive correlation with OP^DCFH (Spearman's analysis, p < 0.05) was detected for IL-8 secretion and γ-H2AX. These results provide a biological support to the implementation in air quality monitoring of OP measurements as a useful proxy to estimate PM-induced cellular toxicological responses. In addition, these results provide new insights for the assessment of the ability of secondary aerosol in the background atmosphere to induce oxidative stress and health effects.

100 项与 PAT-PM-1 相关的药物交易

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适应症	最高研发状态	国家/地区	公司	日期
胰腺癌	药物发现	德国	OncoMab GmbH	-
胰腺癌	药物发现	美国	Acceptys, Inc.	-
胰腺癌	药物发现	澳大利亚	Patrys Ltd.	-
胰腺癌	药物发现	德国	OncoMab GmbH	-
胰腺癌	药物发现	美国	Acceptys, Inc.	-
胰腺癌	药物发现	澳大利亚	Patrys Ltd.	-