Internal water circulation mediated synergistic co-hydrolysis of PET/cotton textile blends in gamma-valerolactone.

Recycling strategies for mixed plastics and textile blends currently aim for recycling only one of the components. Here, we demonstrate a water coupling strategy to co-hydrolyze polyester/cotton textile blends into polymer monomers and platform chemicals in gamma-valerolactone. The blends display a proclivity for achieving an augmented 5-hydroxymethylfurfural yield relative to the degradation of cotton alone. Controlled experiments and preliminary mechanistic studies underscore that the primary driver behind this heightened conversion rate lies in the internal water circulation. The swelling and dissolving effect of gamma-valerolactone on polyester enables a fast hydrolysis of polyester at much lower concentration of acid than the one in the traditional hydrolysis methods, effectively mitigating the excessive degradation of cotton-derived product and undesirable product formation. In addition, the system is also applicable to different kinds of blends and PET mixed plastics. This strategy develops an attractive path for managing end-of-life textiles in a sustainable and efficient way.

Oxidative Upcycling of Polyethylene to Long Chain Diacid over Co-MCM-41 Catalyst.

Plastic pollution is an emerging global threat due to lack of effective methods for transforming waste plastics into useful resources. Here, we demonstrate a direct oxidative upcycling of polyethylene into high-value and high-volume long chain (C10-C20) saturated dicarboxylic acids in high carbon yield of 85.9% over cobalt-doped MCM-41 molecular sieves, in the absence of any solvent or precious metal catalyst. The distribution of the dicarboxylic acids can be controllably adjusted from short-chain (C4-C10) to long-chain ones (C10-C20) through changing cobalt loading of MCM-41 under nanoconfinement. Highly and sparsely dispersed cobalt along with confined space of mesoporous structure enables complete degradation of polyethylene and high selectivity of dicarboxylic acid in mild condition. So far, this is the first report on highly selective one-step preparation of long chain dicarboxylic acids. The approach provides an attractive solution to tackle plastic pollution and a promising alternative route to long chain diacids.

Study of (k,Θ)-Hilfer fractional differential and inclusion systems on the glucose graph.

This article combines (k,Θ)-Hilfer fractional calculus with glucose molecular graph, defines fractional differential and inclusion systems on each edge of a glucose molecular graph by the assumption that 0 or 1 marks the vertices, and studies the single-valued and multi-valued (k,Θ)-Hilfer type fractional boundary value problems on the glucose molecular graph. On the one hand, the existence and uniqueness of solutions in the single-valued case are proved by using several fixed point theorems. On the other hand, in the multi-valued case, we consider that the right side of the inclusion has convex valued and non-convex value. By applying Leray-Schauder nonlinear alternative method of multi-valued maps as well as Covitz-Nadler fixed point theorem of multi-valued contractions, two existence results are obtained respectively. On this basis, we also get the topological structure of the solution set, which is a pioneering work for (k,Θ)-Hilfer fractional differential inclusion on the glucose graph. Finally, several examples are provided to verify the reliability of our proposed results.

METTL3 facilitates prostate cancer progression via inducing HOXC6 m6A modification and stabilizing its expression through IGF2BP2-dependent mechanisms.

HOXC6 (Homeobox C6) and methyltransferase-like 3 (METTL3) have been shown to be involved in the progression of prostate cancer (PCa). However, whether HOXC6 performs oncogenic effects in PCa via METTL3-mediated N6-methyladenosine (m6A) modification is not yet reported. The Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, scratch, sphere formation assays were applied for cell growth, invasion, migration and stemness analyses. Glycolysis was evaluated by measuring glucose consumption, lactate generation and ATP/ADP ratio. The N6-methyladenine (m6A) modification profile was determined by RNA immunoprecipitation (Me-RIP) assay. The proteins that interact with PGK1 (phosphoglycerate kinase 1) were confirmed by Co-immunoprecipitation assay. Tumor formation experiments in mice were conducted for in vivo assay. PCa tissues and cells showed highly expressed HOXC6 and METTL3. Functionally, the silencing of HOXC6 or METTL3 suppresses PCa cell proliferation, invasion, migration, stemness, and glycolysis. Moreover, METTL3-induced HOXC6 m6A modification to stabilize its expression. In addition, the m6A reader IGF2BP2 directly recognized and bound to HOXC6 mRNA, and maintained its stability, and was involved in the regulation of HOXC6 expression by METTL3. Furthermore, IGF2BP2 knockdown impaired PCa cell proliferation, invasion, migration, stemness, and glycolysis by regulating HOXC6. Besides that HOXC6 interacted with the glycoytic enzyme PGK1 in PCa cells. In vivo assays further showed that METTL3 silencing reduced the expression of HOXC6 and PGK1, and impeded PCa growth. METTL3 promoted PCa progression by maintaining HOXC6 expression in an m6A-IGF2BP2-dependent mechanism.

The GWAS SNP rs80207740 modulates erythrocyte traits via allele-specific binding of IKZF1 and targeting XPO7 gene.

Genome-wide association studies have identified many single nucleotide polymorphisms (SNPs) associated with erythrocyte traits. However, the functional variants and their working mechanisms remain largely unknown. Here, we reported that the SNP of rs80207740, which was associated with red blood cell (RBC) volume and hemoglobin content across populations, conferred enhancer activity to XPO7 gene via allele-differentially binding to Ikaros family zinc finger 1 (IKZF1). We showed that the region around rs80207740 was an erythroid-specific enhancer using reporter assays, and that the G-allele further enhanced activity. 3D genome evidence showed that the enhancer interacted with the XPO7 promoter, and eQTL analysis suggested that the G-allele upregulated expression of XPO7. We further showed that the rs80207740-G allele facilitated the binding of transcription factor IKZF1 in EMSA and ChIP analyses. Knockdown of IKZF1 and GATA1 resulted in decreased expression of Xpo7 in both human and mouse erythroid cells. Finally, we constructed Xpo7 knockout mouse by CRISPR/Cas9 and observed anemic phenotype with reduced volume and hemoglobin content of RBC, consistent to the effect of rs80207740 on erythrocyte traits. Overall, our study demonstrated that rs80207740 modulated erythroid indices by regulating IKZF1 binding and Xpo7 expression.

The Bifunctional Effects of Lactoferrin (LFcinB11) in Inhibiting Neural Cell Adhesive Molecule (NCAM) Polysialylation and the Release of Neutrophil Extracellular Traps (NETs).

The expression of polysialic acid (polySia) on the neuronal cell adhesion molecule (NCAM) is called NCAM-polysialylation, which is strongly related to the migration and invasion of tumor cells and aggressive clinical status. Thus, it is important to select a proper drug to block tumor cell migration during clinical treatment. In this study, we proposed that lactoferrin (LFcinB11) may be a better candidate for inhibiting NCAM polysialylation when compared with CMP and low-molecular-weight heparin (LMWH), which were determined based on our NMR studies. Furthermore, neutrophil extracellular traps (NETs) represent the most dramatic stage in the cell death process, and the release of NETs is related to the pathogenesis of autoimmune and inflammatory disorders, with proposed involvement in glomerulonephritis, chronic lung disease, sepsis, and vascular disorders. In this study, the molecular mechanisms involved in the inhibition of NET release using LFcinB11 as an inhibitor were also determined. Based on these results, LFcinB11 is proposed as being a bifunctional inhibitor for inhibiting both NCAM polysialylation and the release of NETs.

Extracellular vesicle-mediated communication between CD8+ cytotoxic T cells and tumor cells.

Tumors pose a significant global public health challenge, resulting in numerous fatalities annually. CD8+ T cells play a crucial role in combating tumors; however, their effectiveness is compromised by the tumor itself and the tumor microenvironment (TME), resulting in reduced efficacy of immunotherapy. In this dynamic interplay, extracellular vesicles (EVs) have emerged as pivotal mediators, facilitating direct and indirect communication between tumors and CD8+ T cells. In this article, we provide an overview of how tumor-derived EVs directly regulate CD8+ T cell function by carrying bioactive molecules they carry internally and on their surface. Simultaneously, these EVs modulate the TME, indirectly influencing the efficiency of CD8+ T cell responses. Furthermore, EVs derived from CD8+ T cells exhibit a dual role: they promote tumor immune evasion while also enhancing antitumor activity. Finally, we briefly discuss current prevailing approaches that utilize functionalized EVs based on tumor-targeted therapy and tumor immunotherapy. These approaches aim to present novel perspectives for EV-based tumor treatment strategies, demonstrating potential for advancements in the field.

Zn Single-Atom Catalysts Enable the Catalytic Transfer Hydrogenation of α,ß-Unsaturated Aldehydes.

Highly active nonprecious-metal single-atom catalysts (SACs) toward catalytic transfer hydrogenation (CTH) of α,ß-unsaturated aldehydes are of great significance but still are deficient. Herein, we report that Zn-N-C SACs containing Zn-N3 moieties can catalyze the conversion of cinnamaldehyde to cinnamyl alcohol with a conversion of 95.5% and selectivity of 95.4% under a mild temperature and atmospheric pressure, which is the first case of Zn-species-based heterogeneous catalysts for the CTH reaction. Isotopic labeling, in situ FT-IR spectroscopy, and DFT calculations indicate that reactants, coabsorbed at the Zn sites, proceed CTH via a "Meerwein-Ponndorf-Verley" mechanism. DFT calculations also reveal that the high activity over Zn-N3 moieties stems from the suitable adsorption energy and favorable reaction energy of the rate-determining step at the Zn active sites. Our findings demonstrate that Zn-N-C SACs hold extraordinary activity toward CTH reactions and thus provide a promising approach to explore the advanced SACs for high-value-added chemicals.

An Integrative Chemical Recycling Approach for Catalytic Oxidation of Epoxy Resin and in situ Separation of Degraded Products.

Although many approaches have been proposed to recycling waste epoxy resin (EP), the separation of mixed degraded products remains a challenge due to their similar structures. To address this, we present a catalytic oxidation strategy that enables mild degradation of EP and in situ separation of degraded products through supramolecular interactions. The oxidative degradation relies on FeIV=O radicals with strong oxidizing properties, which are generated from the electron transfer of FeCl2 with reaction reagents. As the FeIV=O radicals attacked the C-N bonds of EP, EP was broken into fragments rich in active functional groups. Meanwhile, the FeIV=O radicals were reduced to iron ions that can coordinate with the carboxyl groups on the fragments. As a result, the degraded products with different carboxyl content can be effortlessly separated into liquid and solid phase by coordinating with the catalyst. The success of this work lays the foundation for high-value application of degraded products and provides new design ideas for recycling waste plastics with complex compositions.

Effect of PFDS on the immobilization of Cs+ by metakaolin-based geopolymers in complex environments.

Metakaolin-based geopolymers are very promising materials for improving the safety of low and intermediate level radioactive waste disposal, with respect to ordinary Portland cement, due to their excellent immobilization performance for Cs+ and superior chemical stability. However, their application is limited by the fact that the leaching behavior of Cs+ is susceptible to the presence of other ions in the environment. Here, we propose a way to modify a geopolymer using perfluorodecyltriethoxysilane (PDFS), successfully reducing the leaching rate of Cs+ in the presence of multiple competitive cations due to blocking the diffusion of water. The leachability index of the modified samples in deionized water and highly concentrated saline water reached 11.0 and 8.0, respectively. The reaction mechanism between PDFS and geopolymers was systematically investigated by characterizing the microstructure and chemical bonding of the material. This work provides a facile and successful approach to improve the immobilization of Cs ions by geopolymers in real complex environments, and it could be extended to further improve the reliability of geopolymers used in a range of applications.

Angiotoxic effects of chlorinated polyfluorinated ether sulfonate, a novel perfluorooctane sulfonate substitute, in vivo and in vitro.

Chlorinated polyfluorinated ether sulfonate (Cl-PFESA), a substitute for perfluorooctane sulfonate (PFOS), has been widely used in the Chinese electroplating industry under the trade name F-53B. The production and use of F-53B is keep increasing in recent years, consequently causing more emissions into the environment. Thus, there is a growing concern about the adverse effects of F-53B on human health. However, related research is very limited, particularly in terms of its toxicity to the vascular system. In this study, C57BL/6 J mice were exposed to 0.04, 0.2, and 1 mg/kg F-53B for 12 weeks to assess its impact on the vascular system. We found that F-53B exposure caused aortic wall thickening, collagen deposition, and reduced elasticity in mice. In addition, F-53B exposure led to a loss of vascular endothelial integrity and a vascular inflammatory response. Intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were found to be indispensable for this process. Furthermore, RNA sequencing analysis revealed that F-53B can decrease the repair capacity of endothelial cells by inhibiting their proliferation and migration. Collectively, our findings demonstrate that F-53B exposure induces vascular inflammation and loss of endothelial integrity as well as suppresses the repair capacity of endothelial cells, which ultimately results in vascular injury, highlighting the need for a more thorough risk assessment of F-53B to human health.

Trends in the Incidence and Mortality Rates of Myocarditis in the Chinese Population During 1990-2019: Joinpoint Regression and Age-Period-Cohort Analysis.

BACKGROUND: This study aimed to analyze trends in the burden of myocarditis in the Chinese population during 1990-2019. METHODS: The Global Burden of Disease (GBD) database aims to assess the burden of various diseases and injuries on a global scale, and the contribution of relevant risk factors to the burden of disease was also included. In this study, we collected age-standardized incidence and mortality rates for myocarditis in China from 1990 to 2019 using GBD 2019. The age-period-cohort model was utilized to calculate local drift, longitudinal age patterns, as well as the ratios of period and cohort. RESULTS: The age-standardized incidence and mortality rates of myocarditis in both men and women presented a decreasing trend during 1990-2019 [average annual percentage change (AAPC) of men = -0.202 (95% CI: -0.213 to -0.191); AAPC of women = -0.263 (95% CI: -0.27 to -0.256) for incidence; AAPC of men = -0.233 (95% CI: -0.371 to -0.094); AAPC of women = -0.872 (95% CI: -1.112 to -0.631) for mortality]. Longitudinal age curves showed that myocarditis incidence and mortality rates elevated with age among individuals aged 15-95+ years, with a higher growth rate in men than in women. The period and cohort ratios for both men and women showed similar decreasing trends. Local drift values for the incidence and mortality rates of myocarditis showed an increasing trend among individuals aged 70-75 years and above. CONCLUSION: Although the overall burden of myocarditis in China presented a decreasing trend during 1990-2019, the male and elderly populations still have a higher risk of incidence and mortality. Therefore, it is essential for the health-care system to introduce effective prevention and treatment measures for myocarditis.

Upcycling Waste Thermosetting Polyimide Resins into High-Performance and Sustainable Low-Temperature-Resistance Adhesives.

Thermosetting polyimide (PI) has attracted extensive attention for its excellent properties, but the approaches to its end-of-life management are not sustainable, posing great threat to the ecosystem. Herein, this work proposes a mild, sustainable, and full recovery path for recycling waste carbon fiber reinforced phenylethynyl end-capped PI resin composites. In addition to recycling reaction reagent and woven carbon fiber, degraded products (DPETI) can be fully and directly used as high-performance and sustainable adhesives. DPETI exhibits strong adhesion to various surfaces, with a maximum adhesion strength of 1.84 MPa. Due to the strong supramolecular polymerization behavior without solvent dependence, DPETI demonstrates higher adhesive strength of 2.22 MPa in the extreme environment (-196 °C), which is maintained even after 10 cycles. This work sparks a new thinking for plastic wastes recycling that is to convert unrecyclable wastes into new and sustainable materials, which has the potential to establish new links within circular economies and influence the development of materials science.

Role of Contrast-Enhanced Ultrasound With the Enhancement Pattern and Qualitative Analysis for Differentiating Hypovascular Solid Renal Lesions.

OBJECTIVE: The aim of the work described here was to explore the clinical value of contrast-enhanced ultrasound (CEUS) with the enhancement pattern and qualitative analysis in distinguishing different types of hypovascular solid renal lesions. METHODS: A total of 140 patients with 140 renal tumors (all diagnosed by pathology), which manifested hypo-enhancement on CEUS, were included in this study. We compared conventional ultrasound (US) and CEUS features in five common hypovascular renal tumors, including renal angiomyolipoma (RAML), clear cell renal cell carcinoma (ccRCC), renal pelvic urothelial carcinoma (RPUC), papillary renal cell carcinoma (pRCC) and chromophobe renal cell carcinoma (chRCC). The diagnostic value of conventional US and qualitative parameters of CEUS for differentiating hypovascular solid renal lesions were evaluated. RESULTS: The mean age of patients with a benign renal lesion was younger than that of patients with a malignant renal lesion (p < 0.05). Echogenicity and qualitative parameters such as wash-out, perfusion defects and perilesional rim-like enhancement (PRE) in the two groups differed significantly (all p values <0.05). Benign renal lesions exhibited mainly slow wash-out, whereas malignant renal lesions exhibited predominantly fast wash-out on CEUS (p < 0.05). There were significant differences in echogenicity, such as between RAML and ccRCC, between RAML and RPUC and between RAML and pRCC (all p values <0.05). The rates of appearance of perfusion defect in ccRCC (48%, 13/27) and pRCC (53%, 10/19) were significantly higher than the rate in RAML (14%, 6/43) (p < 0.05). The rates of appearance of PRE in ccRCC (15%, 4/27), pRCC (26%, 5/19) and chRCC (24%,4/17) were significantly higher than the rate in RAML (9%, 4/43) (p < 0.05). CONCLUSION: CEUS with the enhancement pattern and qualitative analysis may be helpful in distinguishing malignant from benign hypovascular renal lesions.

Analysis and comparison of the trends in burden of rheumatic heart disease in China and worldwide from 1990 to 2019.

OBJECTIVES: This study aimed to describe the temporal trends in age and gender burdens of rheumatic heart disease (RHD) in China from 1990 to 2019, including incidence, prevalence, mortality, and disability-adjusted life years (DALYs), and to compare them with the global burden of the disease. METHODS: Using open data from the Global Burden of Disease (GBD) database from 1990 to 2019, this study analyzed the characteristics of RHD burden in China and worldwide, including changes in incidence, prevalence, mortality, and DALYs. Joinpoint was used to calculate the average annual percentage change (AAPC) and the corresponding 95% confidence interval (95% CI) to reflect the trends in the burden of RHD. A comprehensive comparative analysis of the differences in RHD burden between China and the rest of the world was conducted from multiple dimensions, including age, gender, and time periods. RESULTS: From 1990 to 2019, the age-standardized incidence rate (ASIR) of RHD in China decreased from 29.62/100,000 to 23.95/100,000, while the global ASIR increased from 32.69/100,000 to 37.40/100,000. The age-standardized prevalence rate (ASPR) in China decreased from 446.15/100,000 to 390.24/100,000, while the global ASPR increased from 451.56/100,000 to 513.68/100,000. The age-standardized rates of mortality (ASMR) in China decreased from 18.11/100,000 to 4.04/100,000, while the global ASMR decreased from 8.94/100,000 to 3.85/100,000. The age-standardized DALY rate (ASDR) in China decreased from 431.45/100,000 to 93.73/100,000, while the global ASDR decreased from 283.30/100,000 to 132.88/100,000. The AAPC of ASIR, ASPR, ASMR, and ASDR in China was - 0.73%, -0.47%, -5.10%, and - 5.21%, respectively, while the AAPC of the global burden of RHD was 0.48%, 0.45%, -2.87%, and - 2.58%, respectively. The effects of age and gender on the burden of RHD were different. ASIR generally decreased with increasing age, while ASPR increased first and then decreased. ASMR and ASDR increased with increasing age. Women had higher incidence and mortality rates of RHD than men. CONCLUSION: From 1990 to 2019, the incidence, prevalence, mortality, and DALYs of RHD in China decreased, indicating a relative reduction in the burden of RHD in China. The burden of RHD is age-related, with a higher prevalence observed in the younger population, a peak incidence among young adults, and a higher mortality rate among the elderly population. Women are more susceptible to RHD and have a higher risk of mortality than men. Given China's large population and aging population, RHD remains a significant public health challenge in China.

Association of per- and polyfluoroalkyl substances with hepatic steatosis and metabolic dysfunction-associated fatty liver disease among patients with acute coronary syndrome.

Etiology of hepatic steatosis and metabolic dysfunction-associated fatty liver disease (MAFLD) among acute coronary syndrome (ACS) remains unclear. Existing studies suggested the potential role of per- and polyfluoroalkyl substances (PFAS) in comorbidity of hepatic steatosis among ACS patients. Therefore, we conducted a cross-sectional study based on the ACS inpatients to assess the associations of plasma PFAS congeners and mixtures with hepatic steatosis and MAFLD. This study included 546 newly diagnosed ACS patients. Twelve PFAS were quantified using ultra-high-performance liquid chromatography-tandem mass spectrometry. Hepatic steatosis was defined by hepatic steatosis index (HSI). MAFLD was defined as the combination of hepatic steatosis based on the risk factor calculation with metabolic abnormalities. Generalized linear model was used to examine the associations of PFAS congeners with HSI and MAFLD. Adaptive elastic net (AENET) was further used for PFAS congeners selection. Mixture effects were also assessed with Bayesian kernel machine regression model (BKMR). Congeners analysis observed significant greater percent change of HSI for each doubling in PFOS (1.82%, 95% CI: 0.87%, 2.77%), PFHxS (1.17%, 95% CI: 0.46%, 1.89%) and total PFAS (1.84%, 95% CI: 0.56%, 3.14%). Moreover, each doubling in PFOS (OR=1.42, 95% CI: 1.13, 1.81), PFHxS (OR=1.31, 95% CI: 1.09, 1.59) and total PFAS (OR=1.43, 95% CI: 1.06, 1.94) was associated with increased risk of MAFLD. In AENET regression, only PFOS presented significant positive associations with HSI. Mixture analysis indicated significant positive associations between PFAS mixtures and HSI. This is the first study to demonstrate associations of PFAS congeners and mixtures with hepatic steatosis and MAFLD among ACS patients, which provides hypothesis into the mechanisms behind comorbidity of hepatic steatosis among ACS patients, as well as tertiary prevention of ACS.

Association between per- and polyfluoroalkyl substances and risk of hypertension: a systematic review and meta-analysis.

Background: Existing evidence indicates that exposure to per- and polyfluoroalkyl substances (PFASs) may increase the risk of hypertension, but the findings are inconsistent. Therefore, we aimed to explore the relationship between PFASs and hypertension through this systematic review and meta-analysis. Methods: We searched PubMed, Embase, and the Web of Science databases for articles published in English that examined the relationship between PFASs and hypertension before 13 August 2022. The random effects model was used to aggregate the evaluation using Stata 15.0 for Windows. We also conducted subgroup analyses by region and hypertension definition. In addition, a sensitivity analysis was carried out to determine the robustness of the findings. Results: The meta-analysis comprised 15 studies in total with 69,949 individuals. The risk of hypertension was substantially and positively correlated with exposure to perfluorooctane sulfonate (PFOS) (OR = 1.31, 95% CI: 1.14, 1.51), perfluorooctanoic acid (PFOA) (OR = 1.16, 95% CI: 1.07, 1.26), and perfluorohexane sulfonate (PFHxS) (OR = 1.04, 95% CI: 1.00, 1.09). However, perfluorononanoic acid (PFNA) exposure and hypertension were not significantly associated (OR = 1.08, 95% CI: 0.99, 1.17). Conclusion: We evaluated the link between PFASs exposure and hypertension and discovered that higher levels of PFOS, PFOA, and PFHxS were correlated with an increased risk of hypertension. However, further high-quality population-based and pathophysiological investigations are required to shed light on the possible mechanism and demonstrate causation because of the considerable variability. Systematic review registration: https://www.crd.york.ac.uk/prospero/ PROSPERO, registration number: CRD 42022358142.

The NMR studies of CMP inhibition of polysialylation.

The overexpression of polysialic acid (polySia) on neural cell adhesion molecules (NCAM) promotes hypersialylation, and thus benefits cancer cell migration and invasion. It has been proposed that the binding between the polysialyltransferase domain (PSTD) and CMP-Sia needs to be inhibited in order to block the effects of hypersialylation. In this study, CMP was confirmed to be a competitive inhibitor of polysialyltransferases (polySTs) in the presence of CMP-Sia and triSia (oligosialic acid trimer) based on the interactional features between molecules. The further NMR analysis suggested that polysialylation could be partially inhibited when CMP-Sia and polySia co-exist in solution. In addition, an unexpecting finding is that CMP-Sia plays a role in reducing the gathering extent of polySia chains on the PSTD, and may benefit for the inhibition of polysialylation. The findings in this study may provide new insight into the optimal design of the drug and inhibitor for cancer treatment.

Tandem oxidative and thermal cracking of polypropylene at low temperatures.

Polypropylene waste was upcycled into terminal functionalized long-chain chemicals with the aid of anionic surfactants. The reaction only needs to be heated at 80 °C for 5 min by coupling exothermic oxidative cracking with endothermic thermal cracking. This work opens a new way to rapidly convert plastic waste into high-value-added chemicals under mild conditions.

Direct identification of total and missing OH reactivities from light-duty gasoline vehicle exhaust in China based on LP-LIF measurement.

Considerable efforts have been devoted to characterising the chemical components of vehicle exhaust. However, these components may not accurately reflect the contribution of vehicle exhaust to atmospheric reactivity because of the presence of species not accounted for ("missing species") given the limitations of analytical instruments. In this study, we improved the laser photolysis-laser-induced fluorescence (LP-LIF) technique and applied it to directly measure the total OH reactivity (TOR) in exhaust gas from light-duty gasoline vehicles in China. The TOR for China I to VI-a vehicles was 15.6, 16.3, 8.4, 2.6, 1.5, and 1.6 × 104 sec-1, respectively, reflecting a notable drop as emission standards were upgraded. The TOR was comparable between cold and warm starts. The missing OH reactivity (MOR) values for China I to IV vehicles were close to zero with a cold start but were much higher with a warm start. The variations in oxygenated volatile organic compounds (OVOCs) under different emission standards and for the two start conditions were similar to those of the MOR, indicating that OVOCs and the missing species may have similar production processes. Online measurement revealed that the duration of the stable driving stage was the primary factor leading to the production of OVOCs and missing species. Our findings underscore the importance of direct measurement of TOR from vehicle exhaust and highlight the necessity of adding OVOCs and other organic reactive gases in future upgrades of emission standards, such that the vehicular contribution to atmospheric reactivity can be more effectively controlled.