Clinical Characteristics of Lung Abscess Caused by Streptococcus Constellatus Infection.

BACKGROUND: This study aimed to understand the clinical characteristics of pulmonary abscess caused by Streptococcus constellatus infection. METHODS: The clinical manifestations, laboratory examination, drug sensitivity, chest CT manifestations, and treatment and prognosis of patients with pulmonary abscess caused by Streptococcus constellatus infection were retrospectively collected and analyzed. RESULTS: A total of 9 cases of pulmonary abscess caused by Streptococcus constellatus infection were confirmed; one case was confirmed by traditional cultures, while metagenomic next-generation sequencing (mNGS) confirmed the other 8 cases. All of the 9 patients had different degrees of cough, sputum, fever, chest pain, and/or dyspnea, and the physical examination showed fast breathing, reduced respiratory sound, or moist rales on the affected side. In laboratory tests, 8 patients had elevated white blood cells and hypoproteinemia upon admission. Blood gas analysis showed an oxygenation index < 300. The antimicrobial susceptibility testing results in 1 patient with culture-confirmed pathogen diagnosis showed that Streptococcus constellatus was susceptible to ampicillin, penicillin G, cefotaxime, ceftriaxone, cefepime, meropenem, chloramphenicol, linezolid, levofloxacin, and vancomycin and resistant to tetracycline and clindamycin. Relevant antibiotic resistance genes were not detected by mNGS in the 8 patients with negative culture and positive mNGS results. A chest CT showed lung consolidation or cavity formation in 9 patients admitted to the hospital, and 5 patients had pleural effusion. 3 cases were admitted to the respiratory intensive care unit (RICU) and 6 cases were admitted to the general ward. There were 3 cases of nasal catheter oxygen inhalation, 1 case of mask oxygen inhalation, and 5 cases of non-invasive ventilator assisted ventilation. All patients received penicillin or respiratory quinolones anti-infection therapy, and 3 cases were treated with a thoracic closed drainage tube. All patients were discharged from the hospital after improvement, and the hospital stay was 15 - 23 days. CONCLUSIONS: Patients with pulmonary abscess caused by Streptococcus constellatus infection have an urgent condition and rapid progression. It is helpful to use mNGS combined with traditional culture as soon as possible to identify the pathogenic bacteria. Penicillin antibiotics should be the first choice for pulmonary abscess caused by a suspected Streptococcus constellatus infection. If a patient´s condition worsens during the treatment, especially for patients who have lesions involving the interlobar fissure or pleura, compressive atelectasis caused by pleural fluid formation or an increase in the amount of pleural effusion needs to be highly suspected.

Unexpected Self-Assembly of Nanographene Oxide Membranes upon Electron Beam Irradiation for Ultrafast Ion Sieving.

Nanographene oxide (nGO) flakes-graphene oxide with a lateral size of ≈100 nm or less-hold great promise for superior flux and energy-efficient nanofiltration membranes for desalination and precise ionic sieving owing to their unique high-density water channels with less tortuousness. However, their potential usage is currently limited by several challenges, including the tricky self-assembly of nano-sized flakes on substrates with micron-sized pores, severe swelling in aqueous solutions, and mechanical instability. Herein, the successful fabrication of a robust membrane stacked with nGO flakes on a substrate with a pore size of 0.22 µm by vacuum filtration is reported. This membrane achieved an unprecedented water permeance above 819.1 LMH bar-1, with a high rejection rate of 99.7% for multivalent metal ions. The nGO flakes prepared using an electron beam irradiation method, have uniquely pure hydroxyl groups and abundant aromatic regions. The calculations revealed the strong hydrogen bonds between two nGO flakes, which arise from hydroxyl groups, coupled with hydrophobic aromatic regions, greatly enhance the stability of stacked flakes in aqueous solutions and increase their effective lateral size. The research presents a simple yet effective approach toward the fabrication of advanced 2D nanographene membranes with superior performance for ion sieving applications.

Molecular Bidents with Two Electrophilic Warheads as a New Pharmacological Modality.

A systematic strategy to develop dual-warhead inhibitors is introduced to circumvent the limitations of conventional covalent inhibitors such as vulnerability to mutations of the corresponding nucleophilic residue. Currently, all FDA-approved covalent small molecules feature one electrophile, leaving open a facile route to acquired resistance. We conducted a systematic analysis of human proteins in the protein data bank to reveal ∼400 unique targets amendable to dual covalent inhibitors, which we term "molecular bidents". We demonstrated this strategy by targeting two kinases: MKK7 and EGFR. The designed compounds, ZNL-8162 and ZNL-0056, are ATP-competitive inhibitors that form two covalent bonds with cysteines and retain potency against single cysteine mutants. Therefore, molecular bidents represent a new pharmacological modality with the potential for improved selectivity, potency, and drug resistance profile.

Plasma EBV quantification is associated with the efficacy of immune checkpoint blockade and disease monitoring in patients with primary pulmonary lymphoepithelioma-like carcinoma.

Objectives: Primary pulmonary lymphoepithelioma-like carcinoma (PLELC) is a subtype of lung carcinoma associated with the Epstein-Barr virus (EBV). The clinical predictive biomarkers of immune checkpoint blockade (ICB) in PLELC require further investigation. Methods: We prospectively analysed EBV levels in the blood and immune tumor biomarkers of 31 patients with ICB-treated PLELC. Viral EBNA-1 and BamHI-W DNA fragments in the plasma were quantified in parallel using quantitative polymerase chain reaction. Results: Progression-free survival (PFS) was significantly longer in EBNA-1 high or BamHI-W high groups. A longer PFS was also observed in patients with both high plasma EBNA-1 or BamHI-W and PD-L1 ≥ 1%. Intriguingly, the tumor mutational burden was inversely correlated with EBNA-1 and BamHI-W. Plasma EBV load was negatively associated with intratumoral CD8+ immune cell infiltration. Dynamic changes in plasma EBV DNA level were in accordance with the changes in tumor volume. An increase in EBV DNA levels during treatment indicated molecular progression that preceded the imaging progression by several months. Conclusions: Plasma EBV DNA could be a useful and easy-to-use biomarker for predicting the clinical activity of ICB in PLELC and could serve to monitor disease progression earlier than computed tomography imaging.

Biomarkers Screening and Mechanisms Analysis of the Restraint Stress-Induced Myocardial Injury in Hyperlipidemia ApoE-/- Mice.

OBJECTIVES: To explore the biomarkers and potential mechanisms of chronic restraint stress-induced myocardial injury in hyperlipidemia ApoE-/- mice. METHODS: The hyperlipidemia combined with the chronic stress model was established by restraining the ApoE-/- mice. Proteomics and bioinformatics techniques were used to describe the characteristic molecular changes and related regulatory mechanisms of chronic stress-induced myocardial injury in hyperlipidemia mice and to explore potential diagnostic biomarkers. RESULTS: Proteomic analysis showed that there were 43 significantly up-regulated and 58 significantly down-regulated differentially expressed proteins in hyperlipidemia combined with the restraint stress group compared with the hyperlipidemia group. Among them, GBP2, TAOK3, TFR1 and UCP1 were biomarkers with great diagnostic potential. KEGG pathway enrichment analysis indicated that ferroptosis was a significant pathway that accelerated the myocardial injury in hyperlipidemia combined with restraint stress-induced model. The mmu_circ_0001567/miR-7a/Tfr-1 and mmu_circ_0001042/miR-7a/Tfr-1 might be important circRNA-miRNA-mRNA regulatory networks related to ferroptosis in this model. CONCLUSIONS: Chronic restraint stress may aggravate myocardial injury in hyperlipidemia mice via ferroptosis. Four potential biomarkers are selected for myocardial injury diagnosis, providing a new direction for sudden cardiac death (SCD) caused by hyperlipidemia combined with the restraint stress.

Efficient Alcoholysis of Poly(ethylene terephthalate) by Using Supercritical Carbon Dioxide as a Green Solvent.

In order to reduce the environmental impact of poly(ethylene terephthalate) (PET) plastic waste, supercritical fluids were used to facilitate effective recovery via improved solvent effects. This work focuses on the mechanisms of supercritical CO2 (ScCO2) during the alcoholysis processing of PET using systematic experiments and molecular dynamics (MD) simulations. The results of the alcoholysis experiment indicated that PET chips can be completely depolymerized within only an hour at 473 K assisted with ScCO2 at an optimal molar ratio of CO2/ethanol of 0.2. Random scission of PET dominates the early stage of the depolymerization reaction process, while specific scission dominates the following stage. Correspondingly, molecular dynamics (MD) simulations revealed that the solubilization and self-diffusion properties of ScCO2 facilitate the transportation of alcohol molecules into the bulk phase of PET, which leads to an accelerated diffusion of both oligomers and small molecules in the system. However, the presence of excessive CO2 has a negative impact on depolymerization by weakening the hydrogen bonding between polyester chain segments and ethanol, as well as decreasing the swelling degree of PET. These data provide a deep understanding of PET degradation by alcohols and the enhancement of ScCO2. It should be expected to achieve an efficient and high-yield depolymerization process of wasted polyesters assisted with ScCO2 at a relatively low temperature.

Microsyringe-based slug-flow microextraction for rapid and accurate determination of antibiotics in highly saline seawater.

BACKGROUND: Extensive use of antibiotics leads to widespread environmental pollution, endangering ecosystems, and human health. It is particularly concerning, posing global threats requiring urgent attention and action. In this regard, the shift to mass spectrometry in determining antibiotics is highly desirable. Significant progress has been made in analyzing and optimizing the sensitivity of high-salt samples. However, the persistence of cumbersome operational procedures presents a significant challenge to this shift. Thus, the persistence of complex operational procedures needs to be addressed. RESULTS: In this study, a rapid and direct method for determining antibiotics in highly saline environmental water samples using microsyringe-based slug-flow microextraction (MSFME)-droplet spray ionization (DSI) mass spectrometry (MS) has been described. The proposed method successfully detected clarithromycin, ofloxacin, and sulfadimidine in seawater within a linear range of 1-1200 ng mL-1, with low limits of detection of 0.19 ng mL-1, 0.17 ng mL-1, and 0.20 ng mL-1, respectively (Signal/Noise = 3). Additionally, spiked real seawater samples of all three antibiotics demonstrated satisfactory recoveries (95.1-107.5%) and precision (RSD≤8.8%). The MSFME-treated high-salt sample (3.5 wt%) showed a mass spectral response intensity 4-5 orders of magnitude higher than the untreated medium-salt sample (0.35 wt%). Furthermore, exploration of the applicability of MSFME showed that it is suitable not only for high-salinity (3.5 wt%) samples but also for salt-free or low-salt and hard water samples rich in calcium and magnesium ions. SIGNIFICANCE: Comparisons with other methods, complex laboratory setups for sample processing are now simplified to a single step, completing the entire process, including desalination and detection, MSFME-DSI-MS provides faster results in less than 1 min while maintaining sensitivity comparable to that of other detection methods. In conclusion, this advancement provides an exceptionally simplified protocol for the rapid, highly sensitive, and quantitative determination of antibiotics in environmental water samples.

Potential causal links of long-term exposure to PM2.5 and its chemical components with the risk of nasopharyngeal carcinoma recurrence: A 10-year cohort study in South China.

There is a lack of evidence from cohort studies on the causal association of long-term exposure to ambient fine particulate matter (PM2.5) and its chemical components with the risk of nasopharyngeal carcinoma (NPC) recurrence. Based on a 10-year prospective cohort of 1184 newly diagnosed NPC patients, we comprehensively evaluated the potential causal links of ambient PM2.5 and its chemical components including black carbon (BC), organic matter (OM), sulfate (SO4 2-), nitrate (NO3 -), and ammonium (NH4 +) with the recurrence risk of NPC using a marginal structural Cox model adjusted with inverse probability weighting. We observed 291 NPC patients experiencing recurrence during the 10-year follow-up and estimated a 33% increased risk of NPC recurrence (hazard ratio [HR]: 1.33, 95% confidence interval [CI]: 1.02-1.74) following each interquartile range (IQR) increase in PM2.5 exposure. Each IQR increment in BC, NH4 +, OM, NO3 -, and SO4 2- was associated with HRs of 1.36 (95%CI: 1.13-1.65), 1.35 (95%CI: 1.07-1.70), 1.33 (95%CI: 1.11-1.59), 1.32 (95%CI: 1.06-1.64), 1.31 (95%CI: 1.08-1.57). The elderly, patients with no family history of cancer, no smoking history, no drinking history, and those with severe conditions may exhibit a greater likelihood of NPC recurrence following exposure to PM2.5 and its chemical components. Additionally, the effect estimates of the five components are greater among patients who were exposed to high concentration than in the full cohort of patients. Our study provides solid evidence for a potential relationship between long-term exposure to PM2.5 and its components and the risk of NPC recurrence.

Ubiquitin-like modification dependent proteasomal degradation and disease therapy.

Although it is believed that ubiquitin (Ub) modification is required for protein degradation in the proteasome system (UPS), several proteins are subject to Ub-independent proteasome degradation, and in many cases ubiquitin-like (UBL) modifications, including neddylation, FAT10ylation, SUMOylation, ISGylation, and urmylation, are essential instead. In this Review, we focus on UBL-dependent proteasome degradation (UBLPD), on proteasome regulators especially shuttle factors and receptors, as well as potential competition and coordination with UPS. We propose that there is a distinct UBL-proteasome system (UBLPS) that might be underestimated in protein degradation. Finally, we investigate the association of UBLPD with muscle wasting and neurodegenerative diseases in which the proteasome is abnormally activated and impaired, respectively, and suggest strategies to modulate UBLPD for disease therapy.

Fenton reaction in the process of "Laser + Fe" mode excited plasma for Rhodamine B degradation.

The spectral emission of laser-induced plasma in water has a broadband continuum containing ultraviolet light, which can be used as a novel light source for the degradation of organic compounds. We studied the degradation process of the organic dye Rhodamine B (RhB) using plasma light source excited by the "Laser + Fe" mode. Spectral analysis and reaction kinetics modelling were used to study the degradation mechanism. The degradation process using this light source could be divided into two stages. The initial stage was mainly photocatalytic degradation, where ultraviolet light broke the chemical bond of RhB, and then RhB was degraded by the strong oxidising ability of ·OH. As the iron and hydrogen ion concentrations increased, the synergistic effect of photocatalysis and the Fenton reaction further enhanced the degradation rate in the later stage. The plasma excited by the "Laser + Fe" mode achieved photodegradation by effectively enhancing the ultraviolet wavelength ratio of the emission spectrum and triggered the Fenton reaction to achieve rapid organic matter degradation. Our findings indicate that the participation of the Fenton reaction can increase the degradation rate by approximately 10 times. Besides, the impact of pH on degradation efficiency demonstrates that both acidic and alkaline environments have better degradation effects than neutral conditions; this is because acidic environments can enhance the Fenton reaction, while alkaline environments can provide more ·OH.

Silencing of ZNF610 suppresses cell proliferation and migration in lung adenocarcinoma.

Zinc finger proteins (ZNFs) play a significant role in the initiation and progression of tumors. Nevertheless, the specific contribution of ZNF610 to lung adenocarcinoma (LUAD) remains poorly understood. This study sought is to elucidate the role of ZNF610 in LUAD. Transcript data of LUAD were obtained from The Cancer Genome Atlas Program (TCGA) database and processed via R program. The expression of ZNF610 was assessed in various cell lines. To compare the proliferative capacity of cells with or without ZNF610 silencing, CCK8, cell colony formation assay, and Celigo label-free cell counting assay were employed. Furthermore, transwell migration and invasion assays were conducted to evaluate the migratory and invasive abilities of the cells. The expression levels of genes and proteins were assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot techniques. In different LUAD cells, the expression level of ZNF610 was found to be significantly higher in LUAD cells compared to MRC-5 and BASE-2B cells. Moreover, the silencing of ZNF610 resulted in a decrease in cell proliferation and migration abilities. Additionally, the apoptosis rate of cells increased upon silencing ZNF610. Notably, the proportion of cells in the G0/G1 phase increased, while the proportion of cells in the S phase decreased following ZNF610 silencing. Finally, ß-catenin and snail were identified as downstream targets of ZNF610 in cells. Our findings suggest that silencing ZNF610 could inhibit LUAD cell proliferation and migration, possibly through the downregulation of ß-catenin and snail.

Genome analysis of extensively drug-resistant Pseudomonas aeruginosa ST1971 from a patient in China hospitalized for severe pneumonia.

OBJECTIVES: The emergence and outbreak of carbapenem-resistant Pseudomonas aeruginosa are a major global public threat. In this study we aimed to characterize the genome of drug-resistant and virulent genes in an extremely drug-resistant (XDR) P. aeruginosa strain to understand its antimicrobial resistance trends and pathogenicity. METHODS: An XDR P. aeruginosa strain was isolated in China from a patient with severe pneumonia. Antimicrobial susceptibility testing, genome sequencing, and phylogenetic analysis were performed. Predictions were fulfilled using curated bioinformatics tools. RESULTS: Assembly of the strain (CRPA190) comprised 76 contigs with a total length of 7 009 318 bp. CRPA190 belongs to sequence type 1971 (ST1971) and the O11 serogroup. Nine prophage regions, three CRISPR arrays, and two Cas clusters were identified. However, no plasmids were predicted. Antibiotic susceptibility tests showed that CRPA190 was resistant to all the tested antibiotics, including carbapenem, polymyxin B, and ceftazidime-avibactam. Forty antimicrobial resistance genes were predicted in CRPA190, including several carbapenemase genes such as blaPDC-142, blaPME-1, blaNDM-1, and blaOXA-902. The isolate was predicted to be pathogenic and possess strong biofilm-forming ability. It harbours virulence genes that are associated with an arsenal of virulence determinants involved in adherence, motility, exotoxins, exoenzymes, immune modulation, biofilms, nutritional/metabolic factors, and effector delivery systems. CONCLUSIONS: These findings enhance our understanding of the resistance and pathogenicity of the ST1971 P. aeruginosa strain that is unique in China and provide a broader perspective on the global epidemiological landscape, suggesting the emergence of P. aeruginosa ST1971, which requires control measures to limit its dissemination.

Fabrication of Flower-Shaped Sb2S3/Fe2O3 Heterostructures for Enhanced Photoelectrochemical Performance.

Antimony sulfide (Sb2S3) has been recognized as a catalytic material for splitting water by solar energy because of its suitable narrow band gap, high absorption coefficient, and abundance of elements. However, many deep-level defects in Sb2S3 result in a significant recombination of photoexcited electron-hole pairs, weakening its photoelectrochemical performance. Here, by using a simple hydrothermal and spin-coating method, we fabricated a step-scheme heterojunction of Sb2S3/α-Fe2O3 to improve the photoelectrochemical performance of pure Sb2S3. Our Sb2S3/α-Fe2O3 photoanode has a photocurrent density of 1.18 mA/cm2 at 1.23 V vs reversible hydrogen electrode, 1.39 times higher than that of Sb2S3 (0.84 mA/cm2). In addition, our heterojunction has a lower onset potential, a higher absorbance intensity, a higher incident photon-to-current conversion efficiency, a higher applied bias photon-to-current efficiency, and a lower charge transfer resistance compared to pure Sb2S3. Based on ultraviolet photoelectron spectroscopy, we constructed a step-scheme band structure of Sb2S3/α-Fe2O3 to explain its photoelectrochemical enhancement. This work offers a promising strategy to optimize the performance of Sb2S3 photoelectrodes for solar-driven photoelectrochemical water splitting.

Impact of Condition Variations on Bioelectrochemical System Performance: An Experimental Investigation of Sulfamethoxazole Degradation.

Bioelectrochemical systems (BESs) are an innovative technology for the efficient degradation of antibiotics. Shewanella oneidensis (S. oneidensis) MR-1 plays a pivotal role in degrading sulfamethoxazole (SMX) in BESs. Our study investigated the effect of BES conditions on SMX degradation, focusing on microbial activity. The results revealed that BESs operating with a 0.05 M electrolyte concentration and 2 mA/cm2 current density outperformed electrolysis cells (ECs). Additionally, higher electrolyte concentrations and elevated current density reduced SMX degradation efficiency. The presence of nutrients had minimal effect on the growth of S. oneidensis MR-1 in BESs; it indicates that S. oneidensis MR-1 can degrade SMX without nutrients in a short period of time. We also highlighted the significance of mass transfer between the cathode and anode. Limiting mass transfer at a 10 cm electrode distance enhanced S. oneidensis MR-1 activity and BES performance. In summary, this study reveals the complex interaction of factors affecting the efficiency of BES degradation of antibiotics and provides support for environmental pollution control.

Polymer chain extenders induce significant toxicity through DAF-16 and SKN-1 pathways in Caenorhabditis elegans: A comparative analysis.

Polymer chain extenders, commonly used in plastic production, have garnered increasing attention due to their potential environmental impacts. However, a comprehensive understanding of their ecological risks remains largely unknown. In this study, we employed the model organism Caenorhabditis elegans to investigate toxicological profiles of ten commonly-used chain extenders. Exposure to environmentally relevant concentrations of these chain extenders (ranging from 0.1 µg L-1 to 10 mg L-1) caused significant variations in toxicity. Lethality assays demonstrated the LC50 values ranged from 92.42 µg L-1 to 1553.65 mg L-1, indicating marked differences in acute toxicity. Sublethal exposures could inhibit nematodes' growth, shorten lifespan, and induce locomotor deficits, neuronal damage, and reproductive toxicity. Molecular analyses further elucidated the involvement of the DAF-16 and SKN-1 signaling pathways, as evidenced by upregulated expression of genes including ctl-1,2,3, sod-3, gcs-1, and gst-4. It implicates these pathways in mediating oxidative stress and toxicities induced by chain extenders. Particularly, hexamethylene diisocyanate and diallyl maleate exhibited markedly high toxicity among the chain extenders, as revealed through a comparative analysis of multiple endpoints. These findings demonstrate the potential ecotoxicological risks of polymer chain extenders, and suggest the need for more rigorous environmental safety assessments.

Ozonolysis of phospholipids at the air-water interface intervened by polyfluoroalkyl substances.

Perfluoroalkyl substances (PFASs) are ubiquitous in the environment and even accumulate in the human body associated with their excellent stability and persistence. However, the effect and reaction mechanism at the molecular level on the cell phospholipid peroxidation remained unclear. In this work, the interfacial reaction of model phospholipids (POPG) intervened by per- and polyfluoroalkyl substances (PFASs) at the air-water interface of a hanged droplet exposed to ozone (O3) was investigated. Perfluorinated carboxylates and sulfonates were evaluated. Four-carbon PFASs promoted interfacial ozonolysis, but PFASs with longer carbon skeletons impeded this chemistry. A model concerning POPG packing was proposed and it was concluded that the interfacial chemistry was mediated by chain length rather than their functional groups. Four-carbon PFASs could couple into POPG ozonolysis by mainly reacting with aldehyde products along with minor Criegee intermediates, but this was not observed for longer PFASs. This is different from that condensed-phase Criegee intermediates preferred to reacting with per-fluoroalkyl carboxylic acids. These results provide insight into the adverse health of PFASs on cell peroxidation.

Effect of hydrothermal treatment on the rheological properties of xanthan gum.

In this study, the effect of hydrothermal treatment with different temperatures (120-180 °C) on the rheological properties of xanthan gum was evaluated. When the temperature of hydrothermal treatment was relatively low (120 °C), the rheological properties of the hydrothermally treated xanthan gum was similar to the untreated xanthan gum (pseudoplastic and solid-like/gel-like behavior). However, as the temperature of hydrothermal treatment was higher, the rheological properties of the hydrothermally treated xanthan gum changed greatly (e.g., a wider range of Newtonian plateaus in flow curves, existence of a critical frequency between the storage modulus (G') and the loss modulus (G") in the dynamic viscoelasticity measurement, variation of complex viscosity). Although the hydrothermal treatment showed little influence on the functional groups of xanthan gum, it altered the micromorphology of xanthan gum from uneven and rough lump-like to thinner and smoother flake-like. In addition, higher concentration (2 %) of hydrothermally treated xanthan gum made its viscosity close to that of the untreated xanthan gum (1 %). Besides, hydrothermal treatment also affected the effect of temperature and salt (CaCl2) adding on the rheological properties of xanthan gum. Overall, this study can provide some useful information on the rheological properties of xanthan gum after hydrothermal treatment.

Synergy of metallic Co and oxygen vacancy sites in Co/Ce-MOF catalysts for efficiently promoting lignin derived phenols and macromolecular lignin hydrodeoxygenation.

The enhanced utilization of biomass-derived chemicals for the generation of high value aromatics through an advanced catalytic strategy has captured considerable attention within the realm of eco-friendly manufacturing. This work presented four innovative three-dimensional rod-shaped mesoporous Ce-based MOF materials, which were coupled with a H-donor solvent to facilitate vanillin hydrodeoxygenation and macromolecular lignin. Under the optimized conditions (30 mg CoCe@C catalyst, 2 MPa N2 pressure, 15 mL isopropanol, 190 °C, and 5 h), the CoCe@C catalyst achieved nearly complete conversion of vanillin and demonstrated 87.8 % selectivity in the hydrogen-donor solvent. The characterization findings suggested that the synergy between metallic Co and oxygen vacancy sites enabled the effective activation of CHO group in vanillin, leading to formation of reactive product MMP. In addition, the optimal CoCe@C catalyst could also achieve macromolecular lignin hydrodeoxygenation to obtain high yield of lignin oil products with narrower molecular weight distribution. This study presented a viable approach for the concurrent utilization of lignin derivatives in the generation of high value fuels and chemicals.

Effects of Chemical Composition and Cross-Linking Degree on the Thermo-Mechanical Properties of Bio-Based Thermosetting Resins: A Molecular Dynamics Simulation Study.

Bio-based epoxy resins have received significant attention in terms of concerns regarding carbon emission. Epoxidized soybean oil (ESO) derived from sustainable feedstock has been widely used to blend with traditional diglycidyl ether of bisphenol-A (DGEBA) to replace some of the petroleum-based components. In this work, molecular dynamics (MD) simulations were applied to track the network formation and predict the performance of methyl hexahydrophthalic anhydride (MHHPA)-cured ESO/DGEBA blend systems. The effects of ESO content and cross-linking degree on the mass density, volumetric shrinkage, glass transition temperature (Tg), coefficient of thermal expansion (CTE), Young's modulus, yield strength, and Poisson's ratio of the epoxy resin were systematically investigated. The results show that systems with high ESO content achieve gelation at low cross-linking degree. The Tg value, Young's modulus, and yield strength increase with the increase in cross-linking degree, but the CTE at the glassy state and Poisson's ratio decrease. The comparison results between the simulated and experimental data demonstrated that the MD simulations can accurately predict the thermal and mechanical properties of ESO-based thermosets. This study gains insight into the variation in thermo-mechanical properties of anhydride-cured ESO/DGEBA-based epoxy resins during the cross-linking process and provides a rational strategy for optimizing bio-based epoxy resins.