RESUMEN

With the continuous control of anthropogenic emissions, China's air quality has improved significantly in recent years. Given this background, research on how the short-term exposure risks caused by air pollution in China have changed is insufficient. This study utilized hourly concentration data from ground observation stations and the official air quality guidelines of the Ministry of Ecology and Environment of China and the World Health Organization as standards to systematically investigate the spatiotemporal characteristics and short-term exposure risks of air pollution in China from 2015 to 2022. The results indicate that various atmospheric pollutants except for ozone showed a decreasing trend yearly. Nationwide, both single pollutant air pollution days (SAPDs) and multiple pollutant air pollution days (MAPDs) showed varying degrees of reduction within 15 and 25 days, respectively. SAPD was dominated mainly by excessive PM2.5 and PM10 pollutants, while MAPD was dominated mainly by excessive pollutant combinations, including PM2.5 + PM10, CO + PM2.5 + PM10, and SO2 + PM2.5 + PM10. As the concentration of atmospheric pollutants decreased, the total excess risk (ER) decreased yearly from 2015 to 2022, but there were significant regional differences. Now, the ER is less than 0.25% in southern China, in the range of 0.25%-0.5% in the North China Plain and some cities in the northeast, and higher than 1% in the northwest. Particulate matter is currently the primary pollutant posing short-term exposure risk in China, especially due to the impact of sandstorm weather. This study indicates that China's atmospheric cleaning action is significantly beneficial for reducing health risks.

Asunto(s)

Contaminantes Atmosféricos , Contaminación del Aire , Exposición a Riesgos Ambientales , Monitoreo del Ambiente , Material Particulado , China , Contaminación del Aire/estadística & datos numéricos , Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Humanos , Medición de Riesgo

RESUMEN

Proton exchange membrane (PEM) electrolysis holds great promise for green hydrogen production, but suffering from high loading of platinum-group metals (PGM) for large-scale deployment. Anchoring PGM-based materials on supports can not only improve the atomic utilization of active sites but also enhance the intrinsic activity. However, in practical PEM electrolysis, it is still challenging to mediate hydrogen adsorption/desorption pathways with high coverage of hydrogen intermediates over catalyst surface. Here, operando generated stable palladium (Pd) hydride nanoclusters anchored on tungsten carbide (WCx) supports were constructed for hydrogen evolution in PEM electrolysis. Under PEM operando conditions, hydrogen intercalation induces formation of Pd hydrides (PdHx) featuring weakened hydrogen binding energy (HBE), thus triggering reverse hydrogen spillover from WCx (strong HBE) supports to PdHx sites, which have been evidenced by operando characterizations, electrochemical results and theoretical studies. This PdHx-WCx material can be directly utilized as cathode electrocatalysts in PEM electrolysis with ultralow Pd loading of 0.022 mg cm-2, delivering the current density of 1 A cm-2 at the cell voltage of ~1.66 V and continuously running for 200 hours without obvious degradation. This innovative strategy via tuning the operando characteristics to mediate reverse hydrogen spillover provide new insights for designing high-performance supported PGM-based electrocatalysts.

RESUMEN

BACKGROUND: Global cyclical outbreaks of human enterovirus infections has positioned human enterovirus A71 (EV-A71) as a neurotropic virus of clinical importance. However, there remains a scarcity of internationally approved antivirals and vaccines. METHODS: In pursuit of repurposing drugs for combating human enteroviruses, we employed a comprehensive pharmacophore- and molecular docking-based virtual screen targeting EV-A71 capsid protein VP1-4, 3C protease, and 3D polymerase proteins. Among 15 shortlisted ligand candidates, we dissected the inhibitory mechanism of Tanomastat in cell-based studies and evaluated its in vivo efficacy in an EV-A71-infected murine model. FINDINGS: We demonstrated that Tanomastat exerts dose-dependent inhibition on EV-A71 replication, with comparable efficacy profiles in enterovirus species A, B, C, and D in vitro. Time-course studies suggested that Tanomastat predominantly disrupts early process(es) of the EV-A71 replication cycle. Mechanistically, live virus particle tracking and docking predictions revealed that Tanomastat specifically impedes viral capsid dissociation, potentially via VP1 hydrophobic pocket binding. Bypassing its inhibition on entry stages, we utilized EV-A71 replication-competent, 3Dpol replication-defective, and bicistronic IRES reporter replicons to show that Tanomastat also inhibits viral RNA replication, but not viral IRES translation. We further showed that orally administered Tanomastat achieved 85% protective therapeutic effect and alleviated clinical symptoms in EV-A71-infected neonatal mice. INTERPRETATION: Our study establishes Tanomastat as a broad-spectrum anti-enterovirus candidate with promising pre-clinical efficacy, warranting further testing for potential therapeutic application. FUNDING: MOE Tier 2 grants (MOE-T2EP30221-0005, R571-000-068-592, R571-000-076-515, R571-000-074-733) and A∗STARBiomedical Research Council (BMRC).

Asunto(s)

Antivirales , Infecciones por Enterovirus , Simulación del Acoplamiento Molecular , Replicación Viral , Replicación Viral/efectos de los fármacos , Humanos , Animales , Antivirales/farmacología , Antivirales/química , Ratones , Infecciones por Enterovirus/tratamiento farmacológico , Infecciones por Enterovirus/virología , Proteínas de la Cápside/genética , Proteínas de la Cápside/metabolismo , Proteínas de la Cápside/antagonistas & inhibidores , ARN Viral/genética , ARN Viral/metabolismo , Cápside/metabolismo , Cápside/efectos de los fármacos , Modelos Animales de Enfermedad , Enterovirus Humano A/efectos de los fármacos , Enterovirus Humano A/genética , Enterovirus Humano A/fisiología , Enterovirus/efectos de los fármacos , Enterovirus/genética , Línea Celular , Replicación de ARN

RESUMEN

Fungal diseases could severely harm agricultural productions. To develop new antifungal agents, based on the Global Natural Products Social Molecular Networking, typical bromine isotope peak ratios, and ultraviolet absorptions, cultivation of the soft coral-derived endophytic fungi Aspergillus terreus EGF7-0-1 with NaBr led to the targeted isolation of 14 new brominated aromatic butenolides (1-14) and six known analogues (15-20). Their structures were elucidated by extensive spectroscopic analysis and quantum chemical calculations. Compounds 1-14 exhibited wildly antifungal activities (against Colletotrichum gloeosporioides, Pestalotiopsis microspora, Fusarium oxysporum f. sp. cubense, Botrytis cinerea, and Diaporthe phoenicicola). The bioassay results showed that compounds 1-14 exhibited excellent antifungal activities against C. gloeosporioides, with concentration for 50% of maximal effect (EC50) values from 2.72 to 130.41 nM. The mechanistic study suggests that compound 1 may disrupt nutrient signaling pathways by reducing the levels of metabolites, such as carbohydrates, lipids, and amino acids, leading to an increase in low-density granules and a decrease in high-density granules in the cytoplasm, accompanied by numerous vacuoles, thereby inhibiting the growth of C. gloeosporioides. Monobrominated γ-butenolide 1 may be expected to exploit a novel agriculturally antifungal leading drug. Meanwhile, compound M1 has conformed antifugual activities against C. gloeosporioides by papayas in vivo.

Asunto(s)

4-Butirolactona , Aspergillus , Fungicidas Industriales , Aspergillus/metabolismo , Aspergillus/efectos de los fármacos , Aspergillus/química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , 4-Butirolactona/farmacología , Fungicidas Industriales/farmacología , Fungicidas Industriales/química , Estructura Molecular , Colletotrichum/efectos de los fármacos , Halogenación , Pruebas de Sensibilidad Microbiana , Antifúngicos/farmacología , Antifúngicos/química

RESUMEN

Red phosphorus anode, attributed to its high specific capacity of 2596 mAh g-1, is expected to improve the energy density of Na-ion batteries. However, the P anode currently is unsatisfactory for practical usage due to the large volume expansion beyond 300%, which brings out uncontrolled brittle failure. To address this challenge, we here design a nacre-like phosphorus anode by resilient graphene oxide staggered together. The staggered structure simultaneously offers mechanical strength and interwoven toughness. Finite element modeling reveals that the sodiation stress from P nanoparticles will be transferred into interlayer pillars as the elastic medium to release sodiation stress. The prepared anode achieves an ultrahigh areal capacity of 13 mAh cm-2 at a mass loading of 5.8 mg cm-2. Notably, the volume change of the anode is limited to approximately 8.2% at full sodiation, significantly lower than that of the traditional phosphorus electrodes.

RESUMEN

A series of novel quinazoline-derived EGFR/HER-2 dual-target inhibitors were designed and synthesized by heterocyclic-containing tail approach. The inhibitory activities against four human epidermal growth factor receptor (HER) isozymes (EGFR, HER-2, HER-3 and HER-4) of all new compounds so designed were investigated in vitro. Compound 12k was found to be the most effective and rather selective dual-target inhibitor of EGFR and HER-2 with inhibitory constant (IC50) values of 6.15 and 9.78 nM, respectively, which was more potent than the clinical used agent Lapatinib (IC50 = 8.41 and 9.41 nM). Meanwhile, almost all compounds showed excellent antiproliferative activities against four cancer cell models (A549, NCI-H1975, SK-BR-3 and MCF-7) and low damage to healthy cells. Among them, compound 12k also exhibited the most prominent antitumor activity. Moreover, the hit compound 12k could bind to EGFR and HER-2 stably in molecular docking and dynamics studies. The following wound healing assay revealed that compound 12k could inhibit the migration of SK-BR-3 cells. Further studies found that compound 12k could arrest cell cycle in the G0/G1 phase and induce SK-BR-3 cells apoptosis. Notably, compound 12k could effectively inhibit breast cancer growth with little toxicity in the SK-BR-3 cell xenograft model. Taken together, in vitro and in vivo results disclosed that compound 12k had high drug potential as a dual-target inhibitor of EGFR/HER-2 to inhibit breast cancer growth.

Asunto(s)

Antineoplásicos , Proliferación Celular , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Receptores ErbB , Inhibidores de Proteínas Quinasas , Quinazolinas , Receptor ErbB-2 , Humanos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Quinazolinas/farmacología , Quinazolinas/química , Quinazolinas/síntesis química , Receptor ErbB-2/antagonistas & inhibidores , Receptor ErbB-2/metabolismo , Proliferación Celular/efectos de los fármacos , Relación Estructura-Actividad , Estructura Molecular , Animales , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Ratones , Línea Celular Tumoral , Simulación del Acoplamiento Molecular , Apoptosis/efectos de los fármacos , Compuestos Heterocíclicos/farmacología , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/síntesis química , Femenino

RESUMEN

BACKGROUND: The role of epinephrine in the treatment of pulp capping in patients with reversible pulpitis is not clear. AIM: To explore the role of epinephrine in the treatment of pulp capping in patients with reversible pulpitis. METHODS: A total of 100 patients with reversible pulpitis who were treated in Anhui Jieshou People's Hospital from January 2020 to December 2021 were included in the study. They were categorized into an observation group (n = 50; treatment with adrenaline) and a control group (n = 50; treatment with zinc oxide eugenol paste). The 24-h postoperative pain, regression time of gingival congestion and redness, clinical efficacy, and incidence of adverse reactions were compared between the groups. Patients were further categorized into the ineffective and effective treatment groups based on clinical efficacy. Logistic multiple regression analysis explored factors affecting the efficacy of pulp capping treatment. RESULTS: A significant difference in 24-h postoperative pain was observed between the groups (P < 0.05), with a higher proportion of grade I pain noted in the observation group than in the control group (P < 0.01). The regression time of gingival congestion and swelling was lower in the observation group (2.61 ± 1.44 d and 2.73 ± 1.36 d, respectively) than in the control group (3.85 ± 1.47 d and 4.28 ± 1.61 d, respectively) (P < 0.05). The 2-wk postoperative total effective rate was lower in the control group (80.00%) than in the observation group (94.00%) (P < 0.05). The incidence of adverse reactions was not significantly different between the control (14.00%) and observation (12.00%) groups (P > 0.05). The proportion of adrenaline usage was lower (P < 0.05) and that of anaerobic digestion by Streptococcus and Fusobacterium nucleatum was higher in the ineffective treatment group than in the effective treatment group (P < 0.05). Logistic multiple regression analysis revealed adrenaline as a protective factor (P < 0.05) and anaerobic digestion by Streptococcus and F. nucleatum as risk factors for pulp capping in reversible pulpitis (P < 0.05). CONCLUSION: Adrenaline demonstrated therapeutic efficacy in pulp capping treatment for reversible pulpitis, reducing pain and improving clinical symptoms safely. It is a protective factor for pulp capping, whereas Streptococcus and F. nucleatum are risk factors. Targeted measures can be implemented to improve clinical efficacy.

RESUMEN

Global Natural Products Social (GNPS) molecular networking platform was applied to discovery the undescribed compounds from the common marine fungi Aspergillus versicolor CGF9-1-2, ultimately resulting in isolation of four new polyketides, decumbenone E (1), decumbenone F (2), 2'-epi-8-O-methylnidurufin (6), (-)-phomoindene A (7), one new nucleoside, 3-methyl-9-(2-methylbutene)-xanthine (8), and five known analogues. Their structures were elucidated based on 1D/2D NMR spectroscopic and HRESIMS data analyses, meanwhile, the absolute configurations of new compounds were established based on the X-ray crystallographic experiments, as well as the electronic circular dichroism (ECD) analysis. All compounds were predicted pharmaceutical chemistry with ten commonly disease-related proteins by molecular docking. In addition, all compounds against TDP1 were performed in vitro, which was consistent with the docking result, and compound 6 shown a weak inhibitory activity.

Asunto(s)

Antozoos , Aspergillus , Simulación del Acoplamiento Molecular , Aspergillus/química , Antozoos/microbiología , Antozoos/química , Estructura Molecular , Animales , Policétidos/aislamiento & purificación , Policétidos/farmacología , Policétidos/química , China , Productos Biológicos/farmacología , Productos Biológicos/aislamiento & purificación , Productos Biológicos/química , Nucleósidos/aislamiento & purificación , Nucleósidos/química , Nucleósidos/farmacología

RESUMEN

In our previous study, we reported a series of N-(9,10-anthraquinone-2-carbonyl) amino acid derivatives as novel inhibitors of xanthine oxidase (XO). Recognizing the suboptimal drug-like properties associated with the anthraquinone moiety, we embarked on a nonanthraquinone medicinal chemistry exploration in the current investigation. Through systematic structure-activity relationship (SAR) studies, we identified a series of 4-(isopentyloxy)-3-nitrobenzamide derivatives exhibiting excellent in vitro potency against XO. The optimized compound, 4-isopentyloxy-N-(1H-pyrazol-3-yl)-3-nitrobenzamide (6k), demonstrated exceptional in vitro potency with an IC50 value of 0.13 µM. Compound 6k showed favorable drug-like characteristics with ligand efficiency (LE) and lipophilic ligand efficiency (LLE) values of 0.41 and 3.73, respectively. In comparison to the initial compound 1d, 6k exhibited a substantial 24-fold improvement in IC50, along with a 1.6-fold enhancement in LE and a 3.7-fold increase in LLE. Molecular modeling studies provided insights into the strong interactions of 6k with critical amino acid residues within the active site. Furthermore, in vivo hypouricemic investigations convincingly demonstrated that 6k significantly reduced serum uric acid levels in rats. The MTT results revealed that compound 6k is nontoxic to healthy cells. The gastric and intestinal stability assay demonstrated that compound 6k exhibits good stability in the gastric and intestinal environments. In conclusion, compound 6k emerges as a promising lead compound, showcasing both exceptional in vitro potency and favorable drug-like characteristics, thereby warranting further exploration.

RESUMEN

Protein tyrosine phosphatase SHP2 activates RAS signaling, which is a novel target for colorectal cancer (CRC) therapy. However, SHP2 inhibitor monotherapy is ineffective for metastatic CRC and a combination therapy is required. In this study, we aimed to improve the antitumor efficacy of SHP2 inhibition and try to explore the resistance mechanism of SHP2 inhibitor. Results showed that WWP1 promoted the proliferation of CRC cells. Genetic or pharmacological inhibition of WWP1 enhanced the effect of SHP2 inhibitor in suppressing tumor growth in vitro and in vivo. WWP1 may mediate feedback reactivation of AKT signaling following SHP2 inhibition. Furthermore, nomogram models constructed with IHC expression of WWP1 and SHP2 greatly improved the accuracy of prognosis prediction for patients with CRC. Our findings indicate that WWP1 inhibitor I3C can synergize with SHP2 inhibitor and is expected to be a new strategy for clinical trials in treating advanced CRC patients.

RESUMEN

Orange juice is a highly nutritious beverage. Traditional pasteurization methods cause nutrient loss and taste changes. Plasma treatment (PT) is an emerging method with a high sterilization rate. This study investigated the effects of corona discharge plasma on the sterilization of orange juice by changes in color difference, total phenol content, and pH value. Single-factor experiments revealed that higher voltage (40 kV) and longer sterilization time (25 min) had better sterilization effects. Response surface analysis indicated that frequency had the greatest impact on sterilization rates, and the optimal sterilization conditions were a voltage of 44.75 kV, a frequency of 9.46 kHz, and a sterilization time of 25 min. Under these conditions, the sterilization rate reached 97.9%, meeting the national standard of 104 colony-forming units/mL (GB7101-2022). Compared to untreated juices, the color difference value was 16.32, the pH value decreased by 0.12, and the total phenol content increased by 0.669 mg/mL. However, the evaporation of water plays an important role in increasing the total phenol co. Moreover, the comparative analysis showed that PT was comparable to pasteurization in terms of sterilization effects, flavor preservation, and the concentration of bioactive components. This study provides a theoretical basis for industrial applications of PT.

RESUMEN

Quantum interference (QI) can strongly affect electric and thermoelectric properties of molecular junctions (MJs). So far, however, a limited number of experimental studies have explored the influence of QI on thermoelectric transport in MJs. To address this open point, we synthesized derivatives of meta-OPE3 with an electron-withdrawing nitro (-NO2) substituent or an electron-donating N,N-dimethyl amine (-NMe2) substituent, attached at two different positions of the central phenylene ring, and systematically studied the electrical conductance and thermopower of the corresponding gold-molecule-gold junctions. We show that (i) the electrical conductance of MJs depends weakly on the polarity of the substituents but strongly on the substitution position and (ii) MJs with the N,N-dimethyl amine group feature a higher thermopower than MJs with the nitro group. We also present calculations based on first principles, which explain these trends and show that the transport properties are highly sensitive to microscopic details in junctions, exhibiting destructive QI features.

RESUMEN

This qualitative study was conducted to understand how gay and bisexual men (GBM) in Taiwan cope with childhood bullying because of their sexual orientation or gender nonconformity. We explored their journey from feeling disturbed to receiving social support, developing coping strategies, and achieving self-growth. Colaizzi's phenomenological approach was used to investigate subject experiences. Semi-structured interviews were conducted with 21 GBM who had experienced high-level sexual bullying in childhood. Relevant data were collected to assess their experiences of sexual bullying, their coping strategies, and subjective effects of corresponding adjustments in interpersonal interactions. Subject experiences concentrated on six themes related to sexual bullying and coping strategies: bullying at developmental stages, bullying everywhere, facing bullying alone, various impacts of bullying, overcoming challenges of interpersonal relationships, and building a strong and carefree self. Our findings can provide mental health professionals with key insights into the contexts of sexual bullying and the associated psychological distress in GBM. This study further clarifies the coping responses of these individuals and their psychological growth following such adverse experiences.

RESUMEN

Discovering new treatments for melanoma will benefit human health. The mechanism by which deoxyhypusine synthase (DHPS) promotes melanoma development remains elucidated. Multi-omics studies have revealed that DHPS regulates m6A modification and maintains mRNA stability in melanoma cells. Mechanistically, DHPS activates the hypusination of eukaryotic translation initiation factor 5A (eIF5A) to assist METTL3 localizing on its mRNA for m6A modification, then promoting METTL3 expression. Structure-based design, synthesis, and activity screening yielded the hit compound GL-1 as a DHPS inhibitor. Notably, GL-1 directly inhibits DHPS binding to eIF5A, whereas GC-7 cannot. Based on the clarification of the mode of action of GL-1 on DHPS, it is found that GL-1 can promote the accumulation of intracellular Cu2+ to induce apoptosis, and antibody microarray analysis shows that GL-1 inhibits the expression of several cytokines. GL-1 shows promising antitumor activity with good bioavailability in a xenograft tumor model. These findings clarify the molecular mechanisms by which DHPS regulates melanoma proliferation and demonstrate the potential of GL-1 for clinical melanoma therapy.

RESUMEN

AIM: This study aimed to compare the effect of inhaled aromatherapy using various essential oils on the sleep quality of critically ill patients. BACKGROUND: Inhalation of essential oils significantly promotes the physiological and psychological health of patients in intensive care units (ICUs). However, research identifying and ranking the effects of different essential oils on the sleep quality of critically ill patients is lacking. DESIGN: This study followed the PRISMA Extension Statement for Reporting of Systematic Reviews Incorporating Network Meta-Analyses of Health Care Interventions (PRISMA-NMA) guidelines. METHODS: A comprehensive search of five databases (Embase, MEDLINE, the Cochrane Library, CINAHL and PsycINFO) was conducted from their inception to March 15, 2023 (with an additional eligible study included dated August 14, 2023). Google Scholar was used as a supplementary method. Frequentist NMA was used to determine the effects of various essential oils. Certainty of evidence (CoE) was assessed using Confidence in Network Meta-Analysis (CINeMA). RESULTS: A total of 11 trials involving 690 critically ill patients were included in the analysis. The NMA of inhaled aromatherapy revealed that the combination of lavender, Matricaria recutita, and neroli essential oils (ratio 6:2:0.5) resulted in the most significant improvement in sleep quality compared to usual care, followed by Rosa damascene, peppermint, Citrus aurantium, pure sunflower oil and lavender oil alone. The overall CoE for the results was rated as low. CONCLUSIONS: The results of this study indicate that a combination of lavender, Matricaria recutita and neroli essential oils significantly positively affected sleep quality among critically ill patients. Despite the low quality of evidence, inhaled aromatherapy is non-invasive and easy to use. RELEVANCE TO CLINICAL PRACTICE: Inhaled aromatherapy can effectively improve sleep quality among critically ill patients. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution applies to this work. STUDY REGISTRATION: The study protocol was registered to the PROSPERO International Prospective Register of Systematic Reviews (protocol number CRD42023433194).

RESUMEN

Solid gastrointestinal tumors often respond poorly to immunotherapy for the complex tumor microenvironment (TME), which is exacerbated by immune system alterations. Immunosenescence is the process of increased diversification of immune genes due to aging and other factors, leading to a decrease in the recognition function of the immune system. This process involves immune organs, immune cells, and the senescence-associated secretory phenotype (SASP). The most fundamental change is DNA damage, resulting in TME remodeling. The main manifestations are worsening inflammation, increased immunosuppressive SASP production, decreased immune cell antitumor activity, and the accumulation of tumor-associated fibroblasts and myeloid-derived suppressor cells, making antitumor therapy less effective. Senotherapy strategies to remove senescent cells and block key senescence processes can have synergistic effects with other treatments. This review focuses on immunoenescence and its impact on the solid TME. We characterize the immunosenescent TME and discuss future directions for antitumor therapies targeting senescence.

Asunto(s)

Neoplasias Gastrointestinales , Inmunosenescencia , Microambiente Tumoral , Humanos , Neoplasias Gastrointestinales/inmunología , Neoplasias Gastrointestinales/terapia , Microambiente Tumoral/inmunología , Inmunosenescencia/inmunología , Animales , Inmunoterapia/métodos , Fenotipo Secretor Asociado a la Senescencia/inmunología , Senescencia Celular/inmunología

RESUMEN

Extensive investigations have proven the effectiveness of elastic binders in settling the challenge of structural damage posed by volume expansion of high-capacity anode used in nanoscale silicon. However, the sluggish ionic conductivity of polymer binder severely restricts the electrode reactions, making it unsuitable for practical applications. Inspired by the biological tissues with rapid neurotransmission and robust muscles, we propose a biomimetic binder that contains ionic conductive polymer (by polymerization reaction of poly(ethylene glycol) diglycidyl ether and polyethylenimine) and rigid polymer backbone (polyacrylic acid), which can effectively mitigate both Li-ion transport resistance and lithiation stress to stabilize the silicon nanoparticles during cycles. Consequently, the silicon anode with biomimetic binder achieves a rate capability of 1897 mAh g-1 at 8.0 A g-1 and capacity retention of 87% after 150 cycles under areal capacity upon 3.0 mAh cm-2. These results demonstrate the possibility of decoupling ionic conductivity from mechanical properties toward practical high-capacity anodes for energy-dense batteries.

RESUMEN

During the snowmelt period, the external erosive forces are dominated by freeze-thaw cycles and snowmelt runoff. These forces may affect soil structure and aggregate stability, thereby influencing snowmelt erosion. The process of snowmelt runoff can lead to the breakdown of aggregates during their transportation. However, few studies examined the effects of freeze-thaw cycles on the breakdown of aggregates during transportation. Focusing on 5-7 and 3-5 mm soil aggregates of typical black soil region in Northeast China, we analyzed the composition of water-stable aggregates, mean weight diameter (MWD), normalized mean weight diameter (NMWD), as well as breakdown rate of soil aggregates (BR) under different freeze-thaw cycles (0, 1, 5, 10, 15 and 20 times) and different transport distances (5, 10, 15, 20, 25 and 30 m). We further investigated the contribution (CT) of both freeze-thaw cycles and transport distances to BR. The results showed that: 1) After freeze-thaw cycles, the 5-7 and 3-5 mm aggregates were mainly composed of particles with a diameter of 0.5-1 mm. With increasing frequency of freeze-thaw cycles, the MWD generally showed a downward trend. Moreover, under the same number of freeze-thaw cycles, the NMWD of 3-5 mm aggregates was higher than that of 5-7 mm aggregates. 2) As the transport distance increased, the BR of 5-7and 3-5 mm aggregates gradually increased. Compared that under control group, the BR under one freeze-thaw cycle increased by 59.7%, 32.2%, 13.7%, 6.2%, 13.4%, 7.5%, and 60.0%, 39.0%, 18.4%, 13.0%, 6.3%, 6.1% at the condition of 5, 10, 15, 20, 25 and 30 m transport distances, respectively. However, with increasing frequency of freeze-thaw cycles, the BR increased slowly. 3) The breakdown of soil aggregates was mainly influenced by the transport distance (CT=54.6%) and freeze-thaw cycles (CT=26.2%). Freeze-thaw cycles primarily altered the stability of soil aggregates, which in turn affected the BR. Therefore, during the snowmelt period, freeze-thaw cycles reduced the stability of soil aggregates, leading to severe breakdown of soil aggregates during snowmelt runoff process. This made the soil more susceptible to migration with snowmelt runoff, which triggered soil erosion. Therefore, more attention should be paid on the prevention of soil erosion during snowmelt period.

Asunto(s)

Congelación , Suelo , Transportes , Suelo/química , China , Erosión del Suelo/prevención & control , Nieve

RESUMEN

Iron-centered N-heterocyclic carbene compounds have attracted much attention in recent years due to their long-lived excited states with charge transfer (CT) character. Understanding the orbital interactions between the metal and ligand orbitals is of great importance for the rational tuning of the transition metal compound properties, e.g., for future photovoltaic and photocatalytic applications. Here, we investigate a series of iron-centered N-heterocyclic carbene complexes with +2, + 3, and +4 oxidation states of the central iron ion using iron L-edge and nitrogen K-edge X-ray absorption spectroscopy (XAS). The experimental Fe L-edge XAS data were simulated and interpreted through restricted-active space (RAS) and multiplet calculations. The experimental N K-edge XAS is simulated and compared with time-dependent density functional theory (TDDFT) calculations. Through the combination of the complementary Fe L-edge and N K-edge XAS, direct probing of the complex interplay of the metal and ligand character orbitals was possible. The σ-donating and π-accepting capabilities of different ligands are compared, evaluated, and discussed. The results show how X-ray spectroscopy, together with advanced modeling, can be a powerful tool for understanding the complex interplay of metal and ligand.