Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
1.
FASEB J ; 38(1): e23347, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38095503

RESUMEN

The pathogenesis of osteoarthritis (OA) is still unclear. Fatty acid binding protein 4 (FABP4), a novel adipokine, has been found to play a role in OA. This study aimed to explore the role of NF-κB in FABP4-induced OA. In the in vivo study, four pairs of 12-week-old male FABP4 knockout (KO) and wild-type (WT) mice were included. The activation of NF-κB was assessed. In parallel, 24 6-week-old male C57/Bl6 mice were fed a high-fat diet (HFD) and randomly allocated to four groups: daily oral gavage with (1) PBS solution; (2) QNZ (NF-κB-specific inhibitor, 1 mg/kg/d); (3) BMS309403 (FABP4-specific inhibitor, 30 mg/kg/d); and (4) BMS309403 (30 mg/kg/d) + QNZ (1 mg/kg/d). The diet and treatment were sustained for 4 months. The knee joints were obtained to assess cartilage degradation, NF-κB activation, and subchondral bone sclerosis. In the in vitro study, a mouse chondrogenic cell line (ATDC5) was cultured. FABP4 was supplemented to stimulate chondrocytes, and the activation of NF-κB was investigated. In parallel, QNZ and NF-κB-specific siRNA were used to inhibit NF-κB. In vivo, the FABP4 WT mice had more significant NF-κB activation than the KO mice. Dual inhibition of FABP4 and NF-κB alleviated knee OA in mice. FABP4 has no significant effect on the activation of the JNK signaling pathway. In vitro, FABP4 directly activated NF-κB in chondrocytes. The use of QNZ and NF-κB-siRNA significantly alleviated the expression of catabolic markers of chondrocytes induced by FABP4. FABP4 induces chondrocyte degeneration by activating the NF-κB pathway.


Asunto(s)
FN-kappa B , Osteoartritis de la Rodilla , Animales , Masculino , Ratones , Condrocitos/metabolismo , Proteínas de Unión a Ácidos Grasos/genética , Proteínas de Unión a Ácidos Grasos/metabolismo , Interleucina-1beta/metabolismo , FN-kappa B/metabolismo , Osteoartritis de la Rodilla/metabolismo , Osteoartritis de la Rodilla/patología , ARN Interferente Pequeño/genética , Transducción de Señal
2.
Nano Lett ; 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39146031

RESUMEN

Rechargeable magnesium batteries (rMBs) are promising candidates for next-generation batteries in which sulfides are widely used as cathode materials. The slow kinetics, low redox reversibility, and poor magnesium storage stability induced by the large Coulombic resistance and ionic polarization of Mg2+ ions have obstructed the development of high-performance rMBs. Herein, a Cu1.8S1-xSex cathode material with a two-dimensional sheet structure has been prepared by an anion-tuning strategy, achieving improved magnesium storage capacity and cycling stability. Element-specific synchrotron radiation analysis is evidence that selenium incorporation has indeed changed the chemical state of Cu species. Density functional theory calculations combined with kinetics analysis reveal that the anionic substitution endows the Cu1.8S1-xSex electrode with favorable charge-transfer kinetics and low ion diffusion barrier. The principal magnesium storage mechanisms and structural evolution process have been revealed in details based on a series of ex situ investigations. Our findings provide an effective heteroatom-tuning tactic of optimizing electrode structure toward advanced energy storage devices.

3.
Nano Lett ; 24(28): 8542-8549, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38973706

RESUMEN

Aqueous aluminum-ion batteries (AAIBs) are considered a strong candidate for the new generation of energy storage devices. The lack of suitable cathode materials has been a bottleneck factor hindering the future development of AAIBs. In this work, we design and construct a highly effective cathode with dual morphologies. Two-dimensional (2D) layered MXene materials possessed good conductivity and hydrophilicity, which are used as the substrates to deposit rod-shaped vanadium oxides (V2O5) to form a three-dimensional (3D) cathode. The cathode design provides a strong boost for the rapid electrochemical activities of rod-shaped V2O5 by embedding/extracting both protons (H+) and aluminum-ion (Al3+). As a result, the V2O5@MXene cathode based AAIB delivers an ultrahigh initial specific capacity of 626 mAh/g at 0.1 A/g with a stable cycle performance up to 100 cycles. This work is a breakthrough for the development of cathode materials for AAIBs.

4.
Small ; : e2400335, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38682593

RESUMEN

Aluminum batteries (ABs) are identified as one of the most promising candidates for the next generation of large-scale energy storage elements because of their efficient three-electron reaction. Compared to ionic electrolytes, aqueous aluminum-ion batteries (AAIBs) are considered safer, less costly, and more environmentally friendly. However, considerable cycling performance is a key issue limiting the development of AAIBs. Stable, efficient, and electrolyte-friendly cathodes are most desirable for AAIBs. Herein, a rod-shaped defect-rich α-MnO2 is designed as a cathode, which is capable to deliver high performance with stable cycling for 180 cycles at 500 mA g-1 and maintains a discharge specific capacity of ≈100 mAh g-1. In addition, the infiltrability simulation is effectively utilized to corroborate the rapid electrochemical reaction brought about by the defective mechanism. With the formation of oxygen vacancies, the dual embedding of protons and metal ions is activated. This work provides a brand-new design for the development and characterization of cathodes for AAIBs.

5.
Small ; : e2401314, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38644698

RESUMEN

Bismuth-based materials have been recognized as the appealing anodes for potassium-ion batteries (PIBs) due to their high theoretical capacity. However, the kinetics sluggishness and capacity decline induced by the structure distortion predominately retard their further development. Here, a heterostructure of polyaniline intercalated Bi2O2CO3/MXene (BOC-PA/MXene) hybrids is reported via simple self-assembly strategy. The ingenious design of heterointerface-rich architecture motivates significantly the interior self-built-in electric field (IEF) and high-density electron flow, thus accelerating the charge transfer and boosting ion diffusion. As a result, the hybrids realize a high reversible specific capacity, satisfying rate capability as well as long-term cycling stability. The in/ex situ characterizations further elucidate the stepwise intercalation-conversion-alloying reaction mechanism of BOC-PA/MXene. More encouragingly, the full cell investigation further highlights its competitive merits for practical application in further PIBs. The present work not only opens the way to the design of other electrodes with an appropriate working mechanism but also offers inspiration for built-in electric-field engineering toward high-performance energy storage devices.

6.
Opt Express ; 32(11): 18441-18452, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38858999

RESUMEN

Imaging the complex dynamics of micro-vibrations plays a fundamental role in the investigation of microelectromechanical systems (MEMS). However, it remains a challenge for achieving both a wide bandwidth and a low noise due to the high photodetector noise and electromagnetic interference at GHz frequencies. Here, we propose a pulsed laser interferometry system with an adaptable switch to image GHz vibrations based on stroboscopic mixing, while measuring lower-frequency vibrations based on the homodyne scheme. The noise power spectral density is shown in both regions from DC to 10 GHz with an average noise down to 30.8 fm/√Hz at GHz frequencies, which holds the highest resolution to the best of our knowledge. Vibrational amplitude and phase mappings of a kHz comb-drive resonator, a GHz piezoelectric transducer, and a GHz film bulk acoustic resonator are presented with animated visualizations and k-space analysis, paving a new paradigm for the first time to image and analyze various MEMS devices of a bandwidth spanning 10 orders of magnitude.

7.
Crit Rev Biotechnol ; : 1-17, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38503543

RESUMEN

As an important cell factory, industrial yeast has been widely used for the production of compounds ranging from bulk chemicals to complex natural products. However, various adverse conditions including toxic products, extreme pH, and hyperosmosis etc., severely restrict microbial growth and metabolic performance, limiting the fermentation efficiency and diminishing its competitiveness. Therefore, enhancing the tolerance and robustness of yeasts is critical to ensure reliable and sustainable production of metabolites in complex industrial production processes. In this review, we provide a comprehensive review of various strategies for improving the tolerance of yeast cells, including random mutagenesis, system metabolic engineering, and material-mediated immobilization cell technology. It is expected that this review will provide a new perspective to realize the response and intelligent regulation of yeast cells to environmental stresses.

8.
Langmuir ; 40(1): 1024-1034, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38113516

RESUMEN

Herein, a novel strategy to establish a porous FeS-Co9S8/carbon aerogel (FeS-Co9S8/NCA) electrocatalyst for oxygen evolution reaction (OER) is fabricated via applying a green biomass carrageenan sulfuration method to CoFe-metal-organic frameworks (MOFs). The FeS-Co9S8/NCA exhibits optimized catalytic activity toward the OER with a lower overpotential of 322 mV, which is overmatched to the majority of transition metal sulfides (TMSs), as well as lifted long-term durability without evident variation in the LSV curves after 3000 cycles. Rechargeable liquid zinc-air battery (ZAB) assembled with FeS-Co9S8/NCA as the OER catalyst indicated a maximum power density of 176 mW cm-2 and superior cycling stability without raised polarization even after 48 h, outperforms commercial RuO2-based ZAB. Furthermore, the flexible solid-state ZAB built with FeS-Co9S8/NCA also demonstrated outdistance properties and bendability. The excellent performance stems from the hierarchical porous aerogel structure, which offers a multiscale mass/electron transport channel, together with the interfacial synergy effect between FeS and Co9S8, which serves as the active site of the OER reaction. Thus, this work instituted a novel strategy for obtaining both clean and efficient transition metal sulfide electrocatalysts for the OER reaction and an environmentally friendly biomass material-based sustainable electrocatalyst.

9.
J Environ Manage ; 364: 121386, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38865920

RESUMEN

Eutrophication is a serious threat to water quality and human health, and chlorophyll-a (Chla) is a key indicator to represent eutrophication in rivers or lakes. Understanding the spatial-temporal distribution of Chla and its accurate prediction are significant for water system management. In this study, spatial-temporal analysis and correlation analysis were applied to reveal Chla concentration pattern in the Fuchun River, China. Then four exogenous variables (wind speed, water temperature, dissolved oxygen and turbidity) were used for predicting Chla concentrations by six models (3 traditional machine learning models and 3 deep learning models) and compare the performance in a river with different hydrology characteristics. Statistical analysis shown that the Chla concentration in the reservoir river segment was higher than in the natural river segment during August and September, while the dominant algae gradually changed from Cyanophyta to Cryptophyta. Moreover, air temperature, water temperature and dissolved oxygen had high correlations with Chla concentrations among environment factors. The results of the prediction models demonstrate that extreme gradient boosting (XGBoost) and long short-term memory neural network (LSTM) were the best performance model in the reservoir river segment (NSE = 0.93; RMSE = 4.67) and natural river segment (NSE = 0.94; RMSE = 1.84), respectively. This study provides a reference for further understanding eutrophication and early warning of algal blooms in different type of rivers.


Asunto(s)
Clorofila A , Eutrofización , Hidrología , Aprendizaje Automático , Ríos , Ríos/química , China , Clorofila A/análisis , Monitoreo del Ambiente/métodos , Calidad del Agua , Clorofila/análisis
10.
J Environ Manage ; 366: 121932, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39043087

RESUMEN

Deep learning models provide a more powerful method for accurate and stable prediction of water quality in rivers, which is crucial for the intelligent management and control of the water environment. To increase the accuracy of predicting the water quality parameters and learn more about the impact of complex spatial information based on deep learning models, this study proposes two ensemble models TNX (with temporal attention) and STNX (with spatio-temporal attention) based on seasonal and trend decomposition (STL) method to predict water quality using geo-sensory time series data. Dissolved oxygen, total phosphorus, and ammonia nitrogen were predicted in short-step (1 h, and 2 h) and long-step (12 h, and 24 h) with seven water quality monitoring sites in a river. The ensemble model TNX improved the performance by 2.1%-6.1% and 4.3%-22.0% relative to the best baseline deep learning model for the short-step and long-step water quality prediction, and it can capture the variation pattern of water quality parameters by only predicting the trend component of raw data after STL decomposition. The STNX model, with spatio-temporal attention, obtained 0.5%-2.4% and 2.3%-5.7% higher performance compared to the TNX model for the short-step and long-step water quality prediction, and such improvement was more effective in mitigating the prediction shift patterns of long-step prediction. Moreover, the model interpretation results consistently demonstrated positive relationship patterns across all monitoring sites. However, the significance of seven specific monitoring sites diminished as the distance between the predicted and input monitoring sites increased. This study provides an ensemble modeling approach based on STL decomposition for improving short-step and long-step prediction of river water quality parameter, and understands the impact of complex spatial information on deep learning model.


Asunto(s)
Aprendizaje Profundo , Ríos , Calidad del Agua , Ríos/química , Monitoreo del Ambiente/métodos , Fósforo/análisis , Modelos Teóricos
11.
J Environ Manage ; 365: 121467, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38908149

RESUMEN

Understanding particle size distribution (PSD) of total suspended sediments in urban runoff is essential for pollutant fate and designing effective stormwater treatment measures. However, the PSDs from different land uses under different weather conditions have yet to be sufficiently studied. This research conducted a six-year water sampling program in 15 study sites to analyze the PSD of total suspended sediments in runoff. The results revealed that the median particle size decreased in the order: paved residential, commercial, gravel lane residential, mixed land use, industrial, and roads. Fine particles less than 125 µm are the dominant particles (over 75%) of total suspended sediments in runoff in Calgary, Alberta, Canada. Roads have the largest percentage of particles finer than 32 µm (49%). Gravel lane residential areas have finer particle sizes than paved residential areas. The results of PSD were compared with previous literature to provide more comprehensive information about PSD from different land uses. The impact of rainfall event types can vary depending on land use types. A long antecedent dry period tends to result in the accumulation of fine particles on urban surfaces. High rainfall intensity and long duration can wash off more coarse particles. The PSD in spring exhibits the finest particles, while fall has the largest percentage of coarse particles. Snowmelt particles are finer for the same land use than that during rainfall events because the rainfall-runoff flows are usually larger than the snowmelt flows.


Asunto(s)
Tamaño de la Partícula , Lluvia , Estaciones del Año , Sedimentos Geológicos/análisis , Sedimentos Geológicos/química , Movimientos del Agua , Monitoreo del Ambiente , Alberta
12.
World J Microbiol Biotechnol ; 40(3): 94, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38349469

RESUMEN

D-glucuronic acid is a kind of glucose derivative, which has excellent properties such as anti-oxidation, treatment of liver disease and hyperlipidemia, and has been widely used in medicine, cosmetics, food and other fields. The traditional production methods of D-glucuronic acid mainly include natural extraction and chemical synthesis, which can no longer meet the growing market demand. The production of D-glucuronic acid by biocatalysis has become a promising alternative method because of its high efficiency and environmental friendliness. This review describes different production methods of D-glucuronic acid, including single enzyme catalysis, multi-enzyme cascade, whole cell catalysis and co-culture, as well as the intervention of some special catalysts. In addition, some feasible enzyme engineering strategies are provided, including the application of enzyme immobilized scaffold, enzyme mutation and high-throughput screening, which provide good ideas for the research of D-glucuronic acid biocatalysis.


Asunto(s)
Ingeniería , Biocatálisis , Catálisis , Técnicas de Cocultivo , Ácido Glucurónico
13.
World J Microbiol Biotechnol ; 40(5): 160, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38607448

RESUMEN

ß-Carotene is an orange fat-soluble compound, which has been widely used in fields such as food, medicine and cosmetics owing to its anticancer, antioxidant and cardiovascular disease prevention properties. Currently, natural ß-carotene is mainly extracted from plants and algae, which cannot meet the growing market demand, while chemical synthesis of ß-carotene cannot satisfy the pursuit for natural products of consumers. The ß-carotene production through microbial fermentation has become a promising alternative owing to its high efficiency and environmental friendliness. With the rapid development of synthetic biology and in-depth study on the synthesis pathway of ß-carotene, microbial fermentation has shown promising applications in the ß-carotene synthesis. Accordingly, this review aims to summarize the research progress and strategies of natural carotenoid producing strain and metabolic engineering strategies in the heterologous synthesis of ß-carotene by engineered microorganisms. Moreover, it also summarizes the adoption of inexpensive carbon sources to synthesize ß-carotene as well as proposes new strategies that can further improve the ß-carotene production.


Asunto(s)
Productos Biológicos , beta Caroteno , Fermentación , Carotenoides , Antioxidantes
14.
J Food Sci Technol ; 61(4): 651-674, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38410265

RESUMEN

To investigate suitable processing methods for improve the flavor while maintaining quality, hellgrammites were subjected to fifteen different processing methods. The samples were tested by sensory evaluation and were analyzed using HS-SPME-GC-MS. The sensory evaluation revealed that five methods for head and chest removal, three wine-fried methods, and three vinegar-roasting methods significantly reduced the levels of hexanal (3129.05 ± 45.77 µg/kg) and heptanal (436.72 ± 7.42 µg/kg), compounds responsible for fishy and earthy flavors, compared to raw samples. The latter two methods exhibited increased aroma flavor. PCA and OPLS-DA analyses suggested that acids, alcohols, and esters played a crucial role in flavor modification. Notably, vinegar-roasting methods demonstrated the highest acid content and had a substantial impact on volatile compounds. Additionally, boiling methods effectively reduced the levels of hazardous compounds, such as toluene and 1,3-Dimethyl-benzene. However, other methods did not exhibit similar efficacy in reducing hazardous compounds. The accumulation of hazardous compounds showed a decreasing trend in the whole insect, head removal, and head and chest removal groups. Moreover, the relative odor activity value consistently identified aldehyde compounds, including hexanal and heptanal, as the main contributors to aroma. Overall, boiling and head and chest removal procedures were suggested as precautionary measures during the initial processing of hellgrammites-based food products. The vinegar-roasting and wine-fried methods could be employed to impart desired flavors, aligning with consumers' preferences. These findings lay the foundation for standardizing processing techniques and ensuring the quality control of products derived from hellgrammites.

15.
Angew Chem Int Ed Engl ; 63(28): e202404481, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38699952

RESUMEN

The pursuit of fabricating high-performance graphene films has aroused considerable attention due to their potential for practical applications. However, developing both stretchable and tough graphene films remains a formidable challenge. To address this issue, we herein introduce mechanical bond to comprehensively improve the mechanical properties of graphene films, utilizing [2]rotaxane as the bridging unit. Under external force, the [2]rotaxane cross-link undergoes intramolecular motion, releasing hidden chain and increasing the interlayer slip distance between graphene nanosheets. Compared with graphene films without [2]rotaxane cross-linking, the presence of mechanical bond not only boosted the strength of graphene films (247.3 vs 74.8 MPa) but also markedly promoted the tensile strain (23.6 vs 10.2 %) and toughness (23.9 vs 4.0 MJ/m3). Notably, the achieved tensile strain sets a record high and the toughness surpasses most reported results, rendering the graphene films suitable for applications as flexible electrodes. Even when the films were stretched within a 20 % strain and repeatedly bent vertically, the light-emitting diodes maintained an on-state with little changes in brightness. Additionally, the film electrodes effectively actuated mechanical joints, enabling uninterrupted grasping movements. Therefore, the study holds promise for expanding the application of graphene films and simultaneously inspiring the development of other high-performance two-dimensional films.

16.
BMC Immunol ; 24(1): 55, 2023 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-38129779

RESUMEN

BACKGROUND: The interaction between the nervous system and the immune system can affect the outcome of a bacterial infection. Staphylococcus aureus skin infection is a common infectious disease, and elucidating the relationship between the nervous system and immune system may help to improve treatment strategies. RESULTS: In this study, we found that the local release of calcitonin gene-related peptide (CGRP) increased during S. aureus skin infection, and S. aureus could promote the release of CGRP from transient receptor potential cation channel subfamily V member 1 (TRPV1+) neurons in vitro. The existence of TRPV1+ neurons inhibited the recruitment of neutrophils to the infected region and regulated the polarization of macrophages toward M2 while inhibiting polarization toward M1. This reduces the level of inflammation in the infected area, which aggravates the local infection. Furthermore, this study demonstrates that TRPV1 may be a target for the treatment of S. aureus skin infections and that botulinum neurotoxin A (BoNT/A) and BIBN4096 may reverse the inhibited inflammatory effect of CGRP, making them potential therapeutics for the treatment of skin infection in S. aureus. CONCLUSIONS: In S. aureus skin infection, TRPV1+ neurons inhibit neutrophil recruitment and regulate macrophage polarization by releasing CGRP. BoNT/A and BIBN4096 may be potential therapeutic agents for S. aureus skin infection.


Asunto(s)
Péptido Relacionado con Gen de Calcitonina , Staphylococcus aureus , Péptido Relacionado con Gen de Calcitonina/farmacología , Infiltración Neutrófila , Neuronas , Macrófagos
17.
J Colloid Interface Sci ; 665: 181-187, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38522158

RESUMEN

Carbonyl or imine-based compounds have received a great deal of attention due to their high specific capacity and designability as cathodes for aqueous rechargeable organo-aluminum batteries. However, the inherent low conductivity and high solubility of carbonyl and imine-based compounds severely affect the cycling stability of aluminum batteries. Therefore, it is urgent to find an organic cathodes material with low solubility and good cycling performance. In this work, dibenzo[a,c]dibenzo[5,6:7,8]quinoxalino[2,3-i]phenazine-10,21-dione (DDQP) were synthesized by simple dehydration condensation to form new imine covalent bonds, which led to the synthesis of imine-conjugated backbone structures with carbonyl, extended π-conjugation planes, and increased active sites, resulting in increased specific capacities. Its storage mechanism with Al(OTF)2+ has also been confirmed. This monovalent ion usually possesses a lower coulombic interaction, which leads to a reduced solubility of DDQP during redox processes and improves its cyclic stability. The specific capacity of DDQP is 252.22 mAh/g at a current density of 400 mA g-1. After cycling, the discharge specific capacity remains at 219 mAh/g. Surprisingly, the conductivity of the battery also is improved by this structure of multiple active sites. And it can be further confirmed by theoretical calculations that the synthesis of DDQP realigns the arrangement of the electron cloud, enhances the electron affinity, and reduces the energy gap. This study provides a new reference for improving the performance of aqueous organic aluminum batteries.

18.
Sci Total Environ ; 913: 169797, 2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38181939

RESUMEN

Ferrihydrite acts as a natural reservoir for nutrient elements, organic matter, and coexisting pollutants through adsorption and coprecipitation. However, the degradation of emerging fluoroquinolone antibiotics during the transformation of ferrihydrite coprecipitates, especially those with various dissociated species, remains insufficiently explored. In this study, Enoxacin (ENO), employed as a model antibiotic, was introduced to prepare ferrihydrite-ENO coprecipitates. The influence of coprecipitated ENO on the transformation of the ferrihydrite-ENO coprecipitate was investigated across different pH conditions. The results revealed that ferrihydrite-ENO coprecipitates thermodynamically transformed into more stable goethite and/or hematite under all pH conditions. In neutral and alkaline conditions, ENO promoted the transformation of coprecipitates into goethite while hindering hematite formation. Conversely, under acidic conditions, ENO directly obstructed the transformation of coprecipitates into hematite. Different dissociated species of ENO displayed distinct degradation pathways. The cationic form of ENO exhibited a greater tendency for hydroxylation and defluorination, while the zwitterion form leaned toward piperazine ring oxidation, with limited preference for quinolone ring oxidation. The anionic form of ENO exhibited the fastest degradation rate. It is essential to emphasize that the toxicity of the degradation products was intricately connected to the specific reaction sites and the functional groups they acquired post-oxidation. These findings offer fresh insights into the role of antibiotics in coprecipitation, the transformation of ferrihydrite coprecipitates, and the fate of coexisting antibiotics.


Asunto(s)
Antibacterianos , Enoxacino , Compuestos de Hierro , Compuestos Férricos , Minerales , Oxidación-Reducción
19.
Microsyst Nanoeng ; 10: 90, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38938527

RESUMEN

MEMS/NEMS resonant sensors hold promise for minute mass and force sensing. However, one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise, which imposes a fundamental limitation upon their signal-to-noise ratio (SNR) and, consequently, the resolution. Particularly, this restriction becomes increasingly pronounced as sensors shrink to the nanoscale. In this work, we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force, obviating the need for external actuation and realizing 'noise-driven' sensors. Those sensors employ the dynamically amplified response to thermal noise at resonances for stimulus detection. We demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of sensors. To overcome the phase incoherence of the drive force, three noise-enabled quantitative sensing mechanisms are developed. We validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature sensors. Noise-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure, and a development that suggests a path to cheaper, simpler, and low-power-consumption sensors.

20.
Sci Total Environ ; 946: 174179, 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-38925387

RESUMEN

The settling behavior of microplastics (MPs) plays a pivotal role in their transport and fate in aquatic environments, but the dominant mechanisms and physics governing the settling of MPs in rivers remain poorly understood. To gain mechanistic insights into the velocity lag of MPs in an open-channel flume under different turbulent flow conditions, an experimental study was conducted using three types of MPs: polystyrene, cellulose acetate, and acrylic, of sphere-shaped particles with diameters ranging from 1 mm to 5 mm. A particle tracking technique was employed to record and analyze the MPs velocity within turbulent flows. The results showed a variation in the vertical settling velocity of MPs ωMP ranging from -26 % to +16 %, when compared to their counterparts in still water (ωs). A new formula for the drag coefficient (Cd) of MP particles was developed by introducing the suspension number (u∗/ωs). The developed Cd formula was used to calculate the resultant velocity lag VMP, with a mean relative error of 16 % compared with the measured values. Further, the study highlighted that the MPs with large Stokes numbers are mainly driven by their own inertia and turbulence has less influence on their settling behavior. This study is crucial for understanding the settling behavior of MPs in turbulent flows and developing their transport and fate models for MPs in riverine systems.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA