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1.
Colloids Surf B Biointerfaces ; 245: 114286, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39378706

RESUMO

Curcumin (Cur) is a natural polyphenol that is one of the most valuable natural products. However, its use as a functional food is limited by low water solubility, chemical instability and poor bioavailability. In this study, a supramolecular co-assembly strategy was used to construct an oleanolic acid-curcumin (OLA-Cur) co-assembly composite nano-slow-release treatment system. As a co-assembled compound, OLA is a widely present pentacyclic triterpenoid compound with multiple biological activities in the plant kingdom, which is expected to jointly alleviate the damaging effects of papain-induced mouse osteoarthritis model. The OLA-Cur NPs shows the solid core-shell structure, which can effectively improve the water solubility of Cur and OLA, and has good stability and sustained release characteristics. The analysis results show that the two compounds are mainly assembled through hydrogen bonding interactions, hydrophobic interactions, and π - π stacking interactions. The OLA-Cur NPs can inhibit the release of pro-inflammatory cytokines TNF-α, IL-6, and IL-1ß induced by LPS in RAW264.7 mouse macrophages, promote the secretion of anti-inflammatory cytokine IL-10, and improve the oxidative stress index of hydrogen peroxide induced human rheumatoid arthritis synovial fibroblasts. In addition, it has a certain improvement effect on cartilage and subchondral bone damage in mouse osteoarthritis models. These findings suggest that constructing co-assembled composite nanoparticles based on pure natural compounds may break through the limitations of a variety of important nutritional ingredients in functional foods.

2.
Artigo em Inglês | MEDLINE | ID: mdl-39447194

RESUMO

OBJECTIVE: Paramagnetic rim lesions (PRLs) are a biomarker of chronic active lesions (CALs), and an important driver of neurological disability in multiple sclerosis (MS). The reason subtending some acute lesions evolvement into CALs is not known. Here we ask whether a relatively lower oxygen content is linked to CALs. METHODS: In this prospective cross-sectional study, 64 people with multiple sclerosis (PwMS), clinically isolated syndrome and radiologically isolated syndrome underwent a 7.0 Tesla (7 T) brain magnetic resonance imaging (MRI). The scanning protocol included a T2-w fluid-attenuated inversion recovery (FLAIR), and a single echo gradient echo from which susceptibility-weighted imaging (SWI) was derived. WM lesions were identified on the T2-w-FLAIR whilst PRLs were identified on the SWI sequence. T2-lesions were classified as PRLs and rimless lesions (PRLs-). We registered a universal vascular atlas to each subject's T2-w-FLAIR and classified each T2-lesions according to its location into watershed- (ws), non-watershed- (nws), and mixed-lesion (m). Ws-lesions were defined as lesions that were fully located in a region between the territories of two major arteries. RESULTS: Out of 1,975 T2-lesions, 88 (4.5%) were PRLs. Ws-regions had a higher number (p = 0.005) and proportion (p < 0.001) of PRLs- compared to nws-regions. Ws-PRL- were larger compared to nws-ones (p = 0.009). The number (p = 0.043) and proportion (p < 0.001) of PRLs was higher in ws-regions compared to nws-ones. Ws-PRLs were not significantly larger than nws-ones (p = 0.195). INTERPRETATION: We propose the novel concept of a link between arterial vascularization and chronic activity in MS by demonstrating a preferential localization of CALs in ws-territories.

3.
Adv Mater ; : e2409137, 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39449216

RESUMO

Gels are formed by fluids that expand throughout the whole volume of 3D polymer networks. To unlock unprecedented properties, exploring new fluids immobilized in polymer networks is crucial. Here, a new liquid metal-polymer gel material termed "metalgel" is introduced via fluid replacement strategy, featuring 92.40% vol liquid metal fluid as a continuum immobilized by interconnected nanoscale polymer network. The unique structure endows metalgel with high electrical conductivity (up to 3.18 × 106 S·m‒1), tissue-like softness (Young's modulus as low as 70 kPa), and low gas permeability (4.50 × 10‒22 m2·s‒1·Pa‒1). Besides, metalgel demonstrates electrical stability under extreme deformations, such as being run over by a 4.5-metric-tonne truck, and maintains its integrity in various environments for up to 180 days. The immobilization of high-volume-fraction liquid metal fluid is realized by electrostatic interactions is further revealed. Potential applications for metalgel are diverse and include soft electromagnetic shielding, hermetic sealing, and stimulating/sensing electrodes in implantable bioelectronics, underscoring its broad applicability.

4.
Lancet Digit Health ; 6(11): e815-e826, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39455194

RESUMO

Deep learning has shown great potential to automate abdominal organ segmentation and quantification. However, most existing algorithms rely on expert annotations and do not have comprehensive evaluations in real-world multinational settings. To address these limitations, we organised the FLARE 2022 challenge to benchmark fast, low-resource, and accurate abdominal organ segmentation algorithms. We first constructed an intercontinental abdomen CT dataset from more than 50 clinical research groups. We then independently validated that deep learning algorithms achieved a median dice similarity coefficient (DSC) of 90·0% (IQR 87·4-91·3%) by use of 50 labelled images and 2000 unlabelled images, which can substantially reduce manual annotation costs. The best-performing algorithms successfully generalised to holdout external validation sets, achieving a median DSC of 89·4% (85·2-91·3%), 90·0% (84·3-93·0%), and 88·5% (80·9-91·9%) on North American, European, and Asian cohorts, respectively. These algorithms show the potential to use unlabelled data to boost performance and alleviate annotation shortages for modern artificial intelligence models.


Assuntos
Algoritmos , Aprendizado Profundo , Tomografia Computadorizada por Raios X , Humanos , Abdome/diagnóstico por imagem
5.
BMC Biol ; 22(1): 233, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39396972

RESUMO

BACKGROUND: Drug-drug interactions (DDIs) can result in unexpected pharmacological outcomes, including adverse drug events, which are crucial for drug discovery. Graph neural networks have substantially advanced our ability to model molecular representations; however, the precise identification of key local structures and the capture of long-distance structural correlations for better DDI prediction and interpretation remain significant challenges. RESULTS: Here, we present DrugDAGT, a dual-attention graph transformer framework with contrastive learning for predicting multiple DDI types. The dual-attention graph transformer incorporates attention mechanisms at both the bond and atomic levels, thereby enabling the integration of short and long-range dependencies within drug molecules to pinpoint key local structures essential for DDI discovery. Moreover, DrugDAGT further implements graph contrastive learning to maximize the similarity of representations across different views for better discrimination of molecular structures. Experiments in both warm-start and cold-start scenarios demonstrate that DrugDAGT outperforms state-of-the-art baseline models, achieving superior overall performance. Furthermore, visualization of the learned representations of drug pairs and the attention map provides interpretable insights instead of black-box results. CONCLUSIONS: DrugDAGT provides an effective tool for accurately predicting multiple DDI types by identifying key local chemical structures, offering valuable insights for prescribing medications, and guiding drug development. All data and code of our DrugDAGT can be found at https://github.com/codejiajia/DrugDAGT .


Assuntos
Interações Medicamentosas , Aprendizado de Máquina , Redes Neurais de Computação , Descoberta de Drogas/métodos
6.
J Med Chem ; 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39433480

RESUMO

Developing drugs for treating glioblastoma has been a significant challenge. Herein, a series of arene ruthenium(II) complexes have been synthesized and investigated as potential candidates to suppress the proliferation and metastasis of glioblastoma. It is found that para-substituent-modified molecules, especially 6, exhibit higher antitumor activity than ortho-substituents. Further studies show that 6 can trigger tumor cell autophagy by regulating the PI3K/AKT/mTOR pathway. Moreover, it is also found that 6 can induce DNA damage in glioblastoma cells through binding and stabilizing VEGF G-quadruplex DNA. Furthermore, it is confirmed that 6 can inhibit the proliferation and metastasis of U87-MG glioblastoma cell in situ xenograft in the zebrafish model. Hence, arene ruthenium(II) complexes can be developed as promising therapeutic agents for glioblastoma treatment in the future.

7.
ACS Omega ; 9(36): 37965-37972, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39281897

RESUMO

Paper lateral flow immunoassays combined with surface-enhanced Raman scattering (SERS) technology have gained increasing attention due to their high sensitivity characteristics resulting from the amplified SERS signals of the plasmon-enhanced optical probes. In contrast to conventional colorimetric lateral flow strips, SERS paper lateral flow strips (SERS-PLFSs) are currently not commercially available for widespread use. Analytical validation is the key step for commercialization. In this work, we have developed a PLFS with a hierarchical SERS probe (gold-silver nanoparticle@Raman reporter@silica) for detection of the US Food and Drug Administration (FDA)-approved traumatic brain injury (TBI) protein biomarker, ubiquitin C-terminal hydrolase-L1 (UCH-L1), in blood plasma samples. Analytical validation has been performed on this SERS-PLFS in terms of the limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, selectivity, and stability. The SERS-PLFS exhibits a reportable range of 0.2-100 ng/mL with a LOD of 0.08 ng/mL toward measurement of UCH-L1 in blood plasma. The SERS-PLFS has been applied to clinical TBI samples. The test results were compared with those from enzyme-linked immunosorbent assay (ELISA), demonstrating a strong correlation between the two analytical methods. This study has important implications in the commercialization of SERS-PLFSs for rapid TBI detection in clinical practice.

8.
Front Plant Sci ; 15: 1416221, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39253573

RESUMO

The timely and accurate acquisition of crop-growth information is a prerequisite for implementing intelligent crop-growth management, and portable multispectral imaging devices offer reliable tools for monitoring field-scale crop growth. To meet the demand for obtaining crop spectra information over a wide band range and to achieve the real-time interpretation of multiple growth characteristics, we developed a novel portable snapshot multispectral imaging crop-growth sensor (PSMICGS) based on the spectral sensing of crop growth. A wide-band co-optical path imaging system utilizing mosaic filter spectroscopy combined with dichroic mirror beam separation is designed to acquire crop spectra information over a wide band range and enhance the device's portability and integration. Additionally, a sensor information and crop growth monitoring model, coupled with a processor system based on an embedded control module, is developed to enable the real-time interpretation of the aboveground biomass (AGB) and leaf area index (LAI) of rice and wheat. Field experiments showed that the prediction models for rice AGB and LAI, constructed using the PSMICGS, had determination coefficients (R²) of 0.7 and root mean square error (RMSE) values of 1.611 t/ha and 1.051, respectively. For wheat, the AGB and LAI prediction models had R² values of 0.72 and 0.76, respectively, and RMSE values of 1.711 t/ha and 0.773, respectively. In summary, this research provides a foundational tool for monitoring field-scale crop growth, which is important for promoting high-quality and high-yield crops.

9.
Mater Horiz ; 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39308419

RESUMO

Low dimensional metal halide perovskites (MHPs) have a soft lattice, leading to strong exciton phonon coupling and exciton localization. Microstructural stiffness engineering is an effective tool for modulating the mechanical and electrical properties of materials, but its complex effects on the luminescence of low dimensional MHPs remain lacking. Here, we report microstructural stiffness engineering of low dimensional MHPs by halogen replacement in Ag-X bonds and [AgX4]3- (X = Br, Cl) units to increase the Young's modulus from 15.6 to 18.3 GPa, resulting in a 10-fold enhancement of X-ray excited luminescence (XEL) intensity and a 16-fold enhancement of photoluminescence quantum yield (PLQY), from 2.8% to 44.3%. Spectroscopic analysis reveals that high stiffness in Rb2AgCl3 facilitates the radiative pathway of defect-bound excitons and efficiently decreases the non-radiative transitions. The projected crystal orbital Hamilton population shows that the shorter Ag-Cl bonds impart Rb2AgCl3 with superior anti-deformation ability upon photoexcitation, leading to enhanced radiation resistance performance. A scintillation screen based on Rb2AgCl3@PDMS achieves zero self-absorption, an ultra-low detection limit of 44.7 nGyair s-1, and a high resolution of 20 lp mm-1, outperforming most reported X-ray detectors. This work sheds light on stiffness engineering for the rational design of efficient emitters.

10.
Chemistry ; : e202402725, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39269324

RESUMO

To tackle the global energy scarcity and environmental degradation, developing efficient electrocatalysts is essential for achieving sustainable hydrogen production via water splitting. Modulating the d-band center of transition metal electrocatalysts is an effective approach to regulate the adsorption energy of intermediates, alter reaction pathways, lower the energy barrier of the rate-determining step, and ultimately improve electrocatalytic water splitting performance. In this review, a comprehensive overview of the recent advancements in modulating the d-band center for enhanced electrocatalytic water splitting is offered. Initially, the basics of the d-band theory are discussed. Subsequently, recent modulation strategies that aim to boost electrocatalytic activity, with particular emphasis on the d-band center as a key indicator in water splitting are summarized. Lastly, the importance of regulating electrocatalytic activity through d-band center, along with the challenges and prospects for improving electrocatalytic water splitting performance by fine-tuning the transition metal d-band center, are provided.

11.
Small ; : e2405838, 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39210638

RESUMO

The heterostructure strategy is currently an effective method for enhancing the catalytic activity of materials. However, the challenge that is how to further improve their catalytic performance, based on the principles of material modification is must addressed. Herein, a strategy is introduced for magnetically regulating the catalytic activity to further enhance the hydrogen evolution reaction (HER) activity for Co0.85Se@CNTs heterostructured catalyst. Building on heterostructure modulation, an external alternating magnetic field (AMF) is introduced to enhance the electronic localization at the active sites, which significantly boosts catalytic performance (71 to 43 mV at 10 mA cm-2). To elucidate the catalytic mechanism, especially under the influence of the AMF, in situ Raman spectroscopy is innovatively applied to monitor the HER process of Co0.85Se@CNTs, comparing conditions with and without the AMF. This study demonstrates that introducing the AMF does not induce a change in the true active site. Importantly, it shows that the Lorentz force generated by the AMF enhances HER activity by promoting water molecule adsorption and O─H bond cleavage, with the Stark tuning rate indicating increased water interaction and bond cleavage efficiency. Theoretical calculations further support that the AMF optimizes energy barriers for key reaction intermediates (steps of *H2O-TS and *H+*1/2H2).

12.
Micromachines (Basel) ; 15(8)2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39203633

RESUMO

The piezoelectric effect refers to a physical phenomenon where piezoelectric materials generate an electric field when subjected to mechanical stress or undergo mechanical deformation when subjected to an external electric field. This principle underlies the operation of piezoelectric sensors. Piezoelectric sensors have garnered significant attention due to their excellent self-powering capability, rapid response speed, and high sensitivity. With the rapid development of sensor techniques achieving high precision, increased mechanical flexibility, and miniaturization, a range of flexible electronic products have emerged. As the core constituents of piezoelectric sensors, flexible piezoelectric composite materials are commonly used due to their unique advantages, including high conformability, sensitivity, and compatibility. They have found applications in diverse domains such as underwater detection, electronic skin sensing, wearable sensors, targeted therapy, and ultrasound diagnostics for deep tissue. The advent of flexible piezoelectric composite materials has revolutionized the design concepts and application scenarios of traditional piezoelectric materials, playing a crucial role in the development of next-generation flexible electronic products. This paper reviews the research progress on flexible piezoelectric composite materials, covering their types and typical fabrication techniques, as well as their applications across various fields. Finally, a summary and outlook on the existing issues and future development of these composite materials are provided.

13.
RSC Med Chem ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39149561

RESUMO

Dihydroorotate dehydrogenase (DHODH), an enzyme that plays a critical role in the de novo pyrimidine biosynthesis, has been recognized as a promising target for the treatment of diseases that involve cellular proliferation, such as autoimmune diseases and cancers. Pharmacological inhibition of human DHODH (hDHODH) that offers a potential therapeutic strategy for the treatment in adult subjects with acute myeloid leukemia (AML) has recently been supported by phase I/II clinical trials for the treatment of patients with relapsed/refractory AML. To facilitate the development of optimized hDHODH inhibitors, the presence of an in vivo imaging probe that is able to demonstrate in vivo target engagement is critical and desirable. Brequinar is one of the most potent hDHODH inhibitors so far discovered. In this work, we use a copper-mediated radiofluorination (CMRF) strategy and compare the chemical design and radiosynthesis starting from either pinacole boronate p-nitrobenzyl ester (4) or tributylstannate (tin) p-nitrobenzyl ester (5), chosen for their suitability as a precursor to [18F]brequinar. We report here the design, synthesis, radiolabeling and characterization of [18F]brequinar, and a preliminary PET imaging study of DHODH in vivo. This study provides the strategies to create [18F]brequinar, the first hDHODH inhibitor PET radiotracer, which will facilitate its use as a tool (theranostics) for hDHODH drug development and for diagnosis and monitoring therapeutic efficacy in AML and cancers.

14.
Prev Med ; 187: 108103, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151805

RESUMO

BACKGROUND: The potential adverse effects of plant-based diets on bone health have raised significant concern, while the prospective evidence is limited. This study aimed to evaluate the association between plant-based diet indexes and incident osteoporosis while exploring the underlying mechanisms involved in this relationship. METHODS: The analysis included 202,063 UK Biobank participants conducted between 2006 and 2022. Plant-based diet indexes (hPDI and uPDI) were calculated using the 24-h dietary questionnaire. Cox proportional risk regression and mediation analysis were used to explore the associations of plant-based diet indexes with osteoporosis, estimating the contribution of BMI and blood markers. RESULTS: We found the highest quintile for hPDI (HR = 1.16; 95% CI: 1.05 to 1.28) and uPDI (HR = 1.15; 95% CI: 1.05 to 1.26) were associated with an increased risk of osteoporosis. BMI was identified as an important mediator in the association between hPDI and osteoporosis, with mediation proportions of 46.17%. For blood markers, the mediating (suppressing) effects of C-reactive protein, alkaline phosphatase, and insulin-like growth factor-1 on the association between uPDI (hPDI) and osteoporosis were significant, ranging from 5.63%-16.87% (4.57%-6.22%). CONCLUSION: Adherence to a plant-based diet is associated with a higher risk of osteoporosis, with BMI and blood markers potentially contributing to this relationship. Notably, even a healthy plant-based diet necessitates attention to weight management to mitigate its impact on bone loss. These findings emphasize the importance of personalized dietary recommendations and lifestyle interventions to decrease the risk of osteoporosis.


Assuntos
Biomarcadores , Índice de Massa Corporal , Dieta Vegetariana , Osteoporose , Humanos , Osteoporose/epidemiologia , Feminino , Estudos Prospectivos , Masculino , Pessoa de Meia-Idade , Biomarcadores/sangue , Reino Unido/epidemiologia , Idoso , Fatores de Risco , Inquéritos e Questionários , Adulto , Dieta Baseada em Plantas
15.
ACS Nano ; 18(32): 21236-21245, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39086003

RESUMO

The detection of mid-infrared light, covering a variety of molecular vibrational spectra, is critical for both civil and military purposes. Recent studies have highlighted the potential of two-dimensional topological semimetals for mid-infrared detection due to their advantages, including van der Waals (vdW) stacking and gapless electronic structures. Among them, mid-infrared photodetectors based on type-II Dirac semimetals have been less studied. In this paper, we present a silicon waveguide integrated type-II Dirac semimetal platinum telluride (PtTe2) mid-infrared photodetector, and further improve detection performance by using PtTe2-graphene heterostructure. For the fabricated silicon waveguide-integrated PtTe2 photodetector, with an external bias voltage of -10 mV and an input optical power of 86 nW, the measured responsivity is 2.7 A/W at 2004 nm and a 3 dB bandwidth of 0.6 MHz is realized. For the fabricated silicon waveguide-integrated PtTe2-graphene photodetector, as the external bias voltage and input optical power are 0.5 V and 0.13 µW, a responsivity of 5.5 A/W at 2004 nm and a 3 dB bandwidth of 35 MHz are obtained. An external quantum efficiency of 119% can be achieved at an input optical power of 0.376 µW.

16.
Small ; : e2406116, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39194638

RESUMO

LiMn2O4 spinel is emerging as a promising cathode material for lithium-ion batteries, largely due to its open framework that facilitates Li+ diffusion and excellent rate performance. However, the charge-discharge cycling of the LiMn2O4 cathode leads to severe structural degradation and rapid capacity decay. Here, an electrochemical activation strategy is introduced, employing a facile galvano-potentiostatic charging operation, to restore the lost capacity of LiMn2O4 cathode without damaging the battery configuration. With an electrochemical activation strategy, the cycle life of the LiMn2O4 cathode is extended from an initial 1500 to an impressive 14 000 cycles at a 5C rate with Li metal as the anode, while increasing the total discharge energy by ten times. Remarkably, the electrochemical activation enhances the diffusion kinetics of Li+, with the diffusion coefficient experiencing a 37.2% increase. Further investigation reveals that this improvement in capacity and diffusion kinetics results from a transformation of the redox-inert LiMnO2 rocksalt layer on the surface of degraded cathodes back into active spinel. This transformation is confirmed through electron microscopy and corroborated by density functional theory simulations. Moreover, the viability of this electrochemical activation strategy has been demonstrated in pouch cell configurations with Li metal as the anode, underscoring its potential for broader application.

17.
Chem Commun (Camb) ; 60(70): 9444-9447, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39139047

RESUMO

Ultrafine ruthenium nanoparticles are encapsulated by single-atom Ni-bonded graphitic carbon nitride (g-C3N4) layers anchored on carbon nanotubes (Ru/Ni-CNCT). The enhanced electronic interaction between Ru nanoparticles and Ni-N(O)-C sites anchored in g-C3N4 layers promotes water adsorption/dissociation and hydrogen evolution.

18.
ACS Appl Mater Interfaces ; 16(32): 42254-42269, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39092826

RESUMO

The development of low-cost and active electrocatalysts signifies an important effort toward accelerating economical water electrolysis and overcoming the sluggish hydrogen or oxygen evolution reaction (HER or OER) kinetics. Herein, we report a scalable and rapid synthesis of inexpensive Ni and MoS2 electrocatalysts on N-doped graphene/carbon cloth substrate to address these challenges. Mesoporous N-doped graphene is synthesized by using electrochemical polymerization of polyaniline (PANI), followed by a rapid one-step photothermal pyrolysis process. The N-doped graphene/carbon cloth substrate improves the interconnection between the electrocatalyst and substrate. Consequently, Ni species deposited on an N-doped graphene OER electrocatalyst shows a low Tafel slope value of 35 mV/decade at an overpotential of 130 mV at 10 mA/cm2 current density in 1 M KOH electrolytes. In addition, Ni-doped MoS2 on N-doped graphene HER electrocatalyst shows Tafel slopes of 37 and 42 mV/decade and overpotentials of 159 and 175 mV, respectively, in acidic and alkaline electrolytes at 10 mA/cm2 current density. Both these values are lower than recently reported nonplatinum-group-metal-based OER and HER electrocatalysts. These excellent electrochemical performances are due to the high electrochemical surface area, a porous structure that improves the charge transfer between electrode and electrolytes, and the synergistic effect between the substrate and electrocatalyst. Raman spectroscopy, X-ray photoelectron spectroscopy, and density functional theory (DFT) calculations demonstrate that the Ni hydroxide species and Ni-doped MoS2 edge sites serve as active sites for OER and HER, respectively. Finally, we also evaluate the performance of the HER electrocatalyst in commercial alkaline electrolyzers.

19.
Small ; : e2404919, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096112

RESUMO

Electrochemical conversion of nitrate (NO3 -) to ammonia (NH3) is an effective approach to reduce nitrate pollutants in the environment and also a promising low-temperature, low-pressure method for ammonia synthesis. However, adequate H* intermediates are highly expected for NO3 - hydrogenation, while suppressing competitive hydrogen evolution. Herein, the effect of H* coverage on the NO3RR for ammonia synthesis by Cu electrocatalysts is investigated. The H* coverage can be adjusted by changing Pd nanoparticle sizes. The optimized Pd@Cu with an average Pd size of 2.88 nm shows the best activity for NO3RR, achieving a maximum Faradaic efficiency of 97% (at -0.8 V vs RHE) and an NH3 yield of 21 mg h-1 cm- 2, from an industrial wastewater level of 500 ppm NO3 -. In situ electrochemical experiments indicate that Pd particles with 2.88 nm can promote NO3 - hydrogenation to NH3 via well-modulated coverage of adsorbed H* species. Coupling the anodic glycerol oxidation reaction, ammonium and formate are successfully obtained as value-added products in a membrane electrode assembly electrolyzer. This work provides a feasible strategy for obtaining size-dependent H* intermediates for hydrogenation.

20.
Environ Pollut ; 359: 124741, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39147220

RESUMO

Microplastics (MPs) and organophosphate flame retardants (OPFRs) have recently become ubiquitous and cumulative pollutants in the oceans. Since OPFRs are added to or adsorbed onto MPs as additives, it is necessary to study the composite contamination of OPFRs and MPs, with less focus on bio-based PLA. Therefore, this study focused on the ecotoxicity of the biodegradable MP polylactic acid (PLA) (5 µm, irregular fragments, 102 and 106 particles/L), and a representative OPFRs tris(1-chloro-2-propyl) phosphate (TCPP, 0.5 and 50 µg/L) at environmental and high concentrations. The mussel Mytilus coruscus was used as a standardised bioindicator for exposure experiments. The focus was on examining oxidative stress (catalase, CAT, superoxide dismutase, SOD, malondialdehyde, MDA), immune responses acid (phosphatase, ACP, alkaline phosphatase, AKP, lysozyme, LZM), neurotoxicity (acetylcholinesterase, AChE), energy metabolism (lactate dehydrogenase, LDH, succinate dehydrogenase, SDH, hexokinase, HK), and physiological indices (absorption efficiency, AE, excretion rate, ER, respiration rate, RR, condition index, CI) after 14 days exposure. The results of significantly increased oxidative stress and immune responses, and significantly disturbed energy metabolism and physiological activities, together with an integrated biomarker response (IBR) analysis, indicate that bio-based PLA MPs and TCPP could cause adverse effects on mussels. Meanwhile, TCPP interacted significantly with PLA, especially at environmental concentrations, resulting in more severe negative impacts on oxidative and immune stress, and neurotoxicity. The more severe adverse effects at environmental concentrations indicate higher ecological risks of PLA, TCPP and their combination in the real marine environment. Our study presents reliable data on the complex effects of bio-based MP PLA, TCPP and their combination on marine organisms and the environment.


Assuntos
Retardadores de Chama , Microplásticos , Mytilus , Estresse Oxidativo , Poliésteres , Poluentes Químicos da Água , Animais , Mytilus/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Retardadores de Chama/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Microplásticos/toxicidade , Organofosfatos/toxicidade , Compostos Organofosforados
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