Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.487
Filtrar
1.
Materials (Basel) ; 17(9)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38730801

RESUMEN

Concrete-filled double steel tubes (CFDSTs) are a load-bearing structure of composite materials. By combining concrete and steel pipes in a nested structure, the performance of the column will be greatly improved. The performance of CFDSTs is closely related to their design. However, existing codes for CFDST design often focus on how to verify the reliability of a design, but specific design parameters cannot be directly provided. As a machine learning technique that can simultaneously learn multiple related tasks, multi-task learning (MTL) has great potential in the structural design of CFDSTs. Based on 227 uniaxial compression cases of CFDSTs collected from the literature, this paper utilized three multi-task models (multi-task Lasso, VSTG, and MLS-SVR) separately to provide multiple parameters for CFDST design. To evaluate the accuracy of models, four statistical indicators were adopted (R2, RMSE, RRMSE, and ρ). The experimental results indicated that there was a non-linear relationship among the parameters of CFDSTs. Nevertheless, MLS-SVR was still able to provide an accurate set of design parameters. The coefficient matrices of two linear models, multi-task Lasso and VSTG, revealed the potential connection among CFDST parameters. The latent-task matrix V in VSTG divided the prediction tasks of inner tube diameter, thickness, strength, and concrete strength into three groups. In addition, the limitations of this study and future work are also summarized. This paper provides new ideas for the design of CFDSTs and the study of related codes.

2.
J Nanobiotechnology ; 22(1): 261, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760744

RESUMEN

Delayed repair of fractures seriously impacts patients' health and significantly increases financial burdens. Consequently, there is a growing clinical demand for effective fracture treatment. While current materials used for fracture repair have partially addressed bone integrity issues, they still possess limitations. These challenges include issues associated with autologous material donor sites, intricate preparation procedures for artificial biomaterials, suboptimal biocompatibility, and extended degradation cycles, all of which are detrimental to bone regeneration. Hence, there is an urgent need to design a novel material with a straightforward preparation method that can substantially enhance bone regeneration. In this context, we developed a novel nanoparticle, mPPTMP195, to enhance the bioavailability of TMP195 for fracture treatment. Our results demonstrate that mPPTMP195 effectively promotes the differentiation of bone marrow mesenchymal stem cells into osteoblasts while inhibiting the differentiation of bone marrow mononuclear macrophages into osteoclasts. Moreover, in a mouse femur fracture model, mPPTMP195 nanoparticles exhibited superior therapeutic effects compared to free TMP195. Ultimately, our study highlights that mPPTMP195 accelerates fracture repair by preventing HDAC4 translocation from the cytoplasm to the nucleus, thereby activating the NRF2/HO-1 signaling pathway. In conclusion, our study not only proposes a new strategy for fracture treatment but also provides an efficient nano-delivery system for the widespread application of TMP195 in various other diseases.


Asunto(s)
Diferenciación Celular , Histona Desacetilasas , Células Madre Mesenquimatosas , Nanopartículas , Animales , Ratones , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Nanopartículas/química , Diferenciación Celular/efectos de los fármacos , Histona Desacetilasas/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Ratones Endogámicos C57BL , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismo , Osteoblastos/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Hemo-Oxigenasa 1/metabolismo , Masculino , Regeneración Ósea/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Núcleo Celular/metabolismo , Curación de Fractura/efectos de los fármacos , Humanos , Proteínas de la Membrana
3.
Artículo en Inglés | MEDLINE | ID: mdl-38763331

RESUMEN

OBJECTIVES: Klebsiella aerogenes is a largely understudied opportunistic pathogen that can cause sepsis and lead to high mortality rates. In this study, we reported the occurrence of carbapenem-resistant blaOXA-181-carrying Klebsiella aerogenes from swine in China and elucidate their genomic characteristics. METHODS: A total of 126 samples, including 109 swine fecal swabs, 14 environmental samples, and 3 feed samples were collected from a pig farm in China. The samples were enriched with LB broth culture and then inoculated into MacConkey agar plates for bacterial isolation. After PCR detection of carbapenemases genes, the blaOXA-181-carrying isolates were subjected to antimicrobial susceptibility testing, and whole-genome sequence analysis. RESULTS: Four Klebsiella aerogenes isolates carrying the blaOXA-181 gene were obtained from swine fecal samples. All the four strains were belonged to ST438. The blaOXA-181 genes were located in IncX3-ColKP3 hybrid plasmids with the core genetic structure of IS26-ΔIS3000-ΔISEcp1-blaOXA-181-ΔlysR-ΔereA-ΔrepA-ISKpn19-tinR-qnrS1-ΔIS2-IS26, which suggests the potential for horizontal transfer and further dissemination of this resistance gene among Enterobacteriaceae and other sources. CONCLUSIONS: This study represents the first instance of OXA-181-producing K. aerogenes being identified from swine feces in China. It is crucial to maintain continuous monitoring and ongoing attention to the detection of K. aerogenes carrying blaOXA-181 and other resistance genes in pigs.

4.
Food Res Int ; 187: 114424, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38763675

RESUMEN

This study aimed to investigate the changes in flavor quality of roasted duck during repetitive freeze-thawing (FT, -20 ℃ for 24 h, then at 4 ℃ for 24 h for five cycles) of raw duck preforms. HS-SPME/GC-MS analysis showed that more than thirty volatile flavor compounds identified in roasted ducks fluctuated with freeze-thawing of raw duck preforms, while hexanal, nonanal, 1-octen-3-ol, and acetone could as potential flavor markers. Compared with the unfrozen raw duck preforms (FT-0), repetitive freeze-thawing increased the protein/lipid oxidation and cross-linking of raw duck preforms by maintaining the higher carbonyl contents (1.40 âˆ¼ 3.30 nmol/mg), 2-thiobarbituric acid reactive substances (0.25 âˆ¼ 0.51 mg/kg), schiff bases and disulfide bond (19.65 âˆ¼ 30.65 µmol/g), but lower total sulfhydryl (73.37 âˆ¼ 88.94 µmol/g) and tryptophan fluorescence intensity. Moreover, A lower protein band intensity and a transformation from α-helixes to ß-sheets and random coils were observed in FT-3 âˆ¼ FT-5. The obtained results indicated that multiple freeze-thawing (more than two cycles) of raw duck preforms could be detrimental to the flavor quality of the roasted duck due to excessive oxidation and degradation.


Asunto(s)
Culinaria , Patos , Congelación , Cromatografía de Gases y Espectrometría de Masas , Gusto , Compuestos Orgánicos Volátiles , Animales , Compuestos Orgánicos Volátiles/análisis , Manipulación de Alimentos/métodos , Oxidación-Reducción , Calidad de los Alimentos , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis
5.
J Glaucoma ; 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38767510

RESUMEN

PURPOSE: To evaluate the impact of the extent of peripheral anterior synechiae (PAS) on the effectiveness and safety of combined phacoemulsification (PEI), goniosynechialysis (GSL), and goniotomy (GT) in eyes with primary angle-closure glaucoma (PACG) and cataract. PATIENTS AND METHODS: This study included patients diagnosed with PACG and cataract who underwent combined PEI and 120 degrees GSL plus GT (PEI+GSL+GT) between April 2020 and October 2022 at 10 ophthalmic institutes. Eligible patients were divided into three groups based on the extent of PAS: 180°≤PAS<270°, 270°≤PAS<360°, and PAS=360°. Data on intraocular pressure (IOP), the number of ocular hypotensive medications, and complications were collected and compared. The study defined complete success as postoperative IOP within the 6-18 mmHg range and a 20% reduction from baseline without the use of topical medications. Qualified success was defined in the same way as complete success, but it allowed for the use of ocular hypotensive medications. RESULTS: Three hundred and four eyes of 283 patients were included. The mean follow-up was 12.50±1.24 months. All groups experienced a significant reduction in IOP after the surgery (P <0.05). There were no significant differences in final IOP, number of medications, and cumulative complete and qualified success rates among the three groups (P >0.05). The groups with 270°≤PAS<360°had a higher frequency of hyphema compared to 180°≤PAS<270° (P = 0.044). CONCLUSIONS: PEI+GSL+GT has proven to be an effective treatment for PACG with cataract over one year period. However, the outcome was not correlated with preoperative extent of PAS. PRCIS: The combination of phacoemulsification, goniosynechialysis and goniotomy is an effective treatment for primary angle-closure glaucoma patients with cataract, and this is not linked to the extent of preoperative peripheral anterior synechiae.

6.
J Agric Food Chem ; 72(20): 11724-11732, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38718268

RESUMEN

Protein post-translational modifications (PTMs) play an essential role in meat quality development. However, the effect of specific PTM sites on meat proteins has not been investigated yet. The characteristics of pyruvate kinase M (PKM) were found to exhibit a close correlation with final meat quality, and thus, serine 99 (S99) and lysine 137 (K137) in PKM were mutated to study their effect on PKM function. The structural and functional properties of five lamb PKM variants, including wild-type PKM (wtPKM), PKM_S99D (S99 phosphorylation), PKM_S99A (PKM S99 dephosphorylation), PKM_K137Q (PKM K137 acetylation), and PKM_K137R (PKM K137 deacetylation), were evaluated. The results showed that the secondary structure, tertiary structure, and polymer formation were affected among different PKM variants. In addition, the glycolytic activity of PKM_K137Q was decreased because of its weakened binding with phosphoenolpyruvate. In the PKM_K137R variant, the actin phosphorylation level exhibited a decrease, suggesting a low kinase activity of PKM_K137R. The results of molecular simulation showed a 42% reduction in the interface area between PKM_K137R and actin, in contrast to wtPKM and actin. These findings are significant for revealing the mechanism of how PTMs regulate PKM function and provide a theoretical foundation for the development of precise meat quality preservation technology.


Asunto(s)
Glucólisis , Piruvato Quinasa , Piruvato Quinasa/metabolismo , Piruvato Quinasa/genética , Piruvato Quinasa/química , Fosforilación , Animales , Acetilación , Ovinos , Procesamiento Proteico-Postraduccional , Proteínas Quinasas/metabolismo , Proteínas Quinasas/genética , Proteínas Quinasas/química , Carne/análisis
7.
Adv Drug Deliv Rev ; 210: 115329, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38729265

RESUMEN

Autoimmune diseases are burdensome conditions that affect a significant fraction of the global population. The hallmark of autoimmune disease is a host's immune system being licensed to attack its tissues based on specific antigens. There are no cures for autoimmune diseases. The current clinical standard for treating autoimmune diseases is the administration of immunosuppressants, which weaken the immune system and reduce auto-inflammatory responses. However, people living with autoimmune diseases are subject to toxicity, fail to mount a sufficient immune response to protect against pathogens, and are more likely to develop infections. Therefore, there is a concerted effort to develop more effective means of targeting immunomodulatory therapies to antigen-presenting cells, which are involved in modulating the immune responses to specific antigens. In this review, we highlight approaches that are currently in development to target antigen-presenting cells and improve therapeutic outcomes in autoimmune diseases.

8.
ACS Nano ; 18(20): 13084-13097, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38727520

RESUMEN

In the current work, the foliar application of selenium nanomaterials (Se0 NMs) suppressed sheath blight in rice (Oryza sativa). The beneficial effects were nanoscale specific and concentration dependent. Specifically, foliar amendment of 5 mg/L Se0 NMs decreased the disease severity by 68.8% in Rhizoctonia solani-infected rice; this level of control was 1.57- and 2.20-fold greater than that of the Se ions with equivalent Se mass and a commercially available pesticide (Thifluzamide). Mechanistically, (1) the controlled release ability of Se0 NMs enabled a wider safe concentration range and greater bioavailability to Se0 NMs, and (2) transcriptomic and metabolomic analyses demonstrated that Se0 NMs simultaneously promoted the salicylic acid- and jasmonic-acid-dependent acquired disease resistance pathways, antioxidative system, and flavonoid biosynthesis. Additionally, Se0 NMs improved rice yield by 31.1%, increased the nutritional quality by 6.4-7.2%, enhanced organic Se content by 44.8%, and decreased arsenic and cadmium contents by 38.7 and 42.1%, respectively, in grains as compared with infected controls. Human simulated gastrointestinal tract model results showed that the application of Se0 NMs enhanced the bioaccessibility of Se in grains by 22.0% and decreased the bioaccessibility of As and Cd in grains by 20.3 and 13.4%, respectively. These findings demonstrate that Se0 NMs can serve as an effective and sustainable strategy to increase food quality and security.


Asunto(s)
Nanoestructuras , Oryza , Enfermedades de las Plantas , Rhizoctonia , Selenio , Oryza/microbiología , Oryza/metabolismo , Oryza/efectos de los fármacos , Selenio/farmacología , Selenio/química , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Humanos , Rhizoctonia/efectos de los fármacos , Nanoestructuras/química , Valor Nutritivo , Resistencia a la Enfermedad/efectos de los fármacos
9.
Am J Trop Med Hyg ; 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38697072

RESUMEN

Soil-transmitted helminthiasis remains a notable health problem in developing countries. In 1990 in Shanghai, a city in eastern China, 47% of the population was affected. Due to a series of comprehensive approaches, the prevalence decreased to 0.5% in 2009. We collected 10-year surveillance data to assess the epidemic situation of soil-transmitted helminth (STH) infections in Shanghai. Stool samples and questionnaires from participants were collected. The Kato-Katz technique was used to detect infections with Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), and Trichuris trichiura. From 2014 to 2023, a total of 77,685 participants were screened for parasitic infections, and the overall prevalence of STH infections decreased from 0.1% to 0% in Shanghai. Of 77,685 participants, 25 (0.03%) were positive for intestinal helminths, with the most common parasite being A. lumbricoides (72.0%). Generally, elderly participants from rural areas with lower education levels were more likely to be infected with STHs. A total of 2,914 questionnaires were collected, and most respondents (72.6%) had good knowledge about the transmission routes of STHs. However, 12.3% of participants did not know the damage to health caused by STHs, and 19.3% had no idea of how to prevent infection. These data demonstrate the current state of STH infections in Shanghai. The results suggest that various comprehensive measures should be encouraged, continuously implemented, and strengthened accordingly so that STH elimination can be integrated into the Healthy China initiative by 2030.

10.
Environ Pollut ; 351: 124049, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38692386

RESUMEN

To explore the impact of different functional groups on Hg(II) adsorption, a range of poly(pyrrole methane)s functionalized by -Cl, -CN, -NH2, -OH and -COOH were synthesized and applied to reveal the interaction between different functional groups and mercury ions in water, and the adsorption mechanism was revealed through combined FT-IR, XPS, and DFT calculations. The adsorption performance can be improved to varying degrees by the incorporation of functional groups. Among them, the oxygen-containing functional groups (-OH and -COOH) exhibit stronger affinity for Hg(II) and can increase the adsorption capacity from 180 mg g-1 to more than 1400 mg g-1 at 318 K, with distribution coefficient (Kd) exceeding 105 mL g-1. The variations in the capture and immobilization capabilities of functionalized poly(pyrrole methane)s predominantly stem from the unique interactions between their functional groups and mercury ions. In particular, oxygen-containing -OH and -COOH effectively capture Hg(OH)2 through hydrogen bonding, and further deprotonate to form the -O-Hg-OH and -COO-Hg-OH complexes which are more stable than those obtained from other functionalized groups. Finally, the ecological safety has been fully demonstrated through bactericidal and bacteriostatic experiments to prove the functionalized poly(pyrrole methane)s can be as an environmentally friendly adsorbent for purifying contaminated water.

11.
Biomaterials ; 309: 122603, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38713972

RESUMEN

Sympathetic nerves play a pivotal role in promoting tumor growth through crosstalk with tumor and stromal cells. Chemotherapy exacerbates the infiltration of sympathetic nerves into tumors, thereby providing a rationale for inhibiting sympathetic innervation to enhance chemotherapy. Here, we discovered that doxorubicin increases the density and activity of sympathetic nerves in breast cancer mainly by upregulating the expression of nerve growth factors (NGFs) in cancer cells. To address this, we developed a combination therapy by co-encapsulating small interfering RNA (siRNA) and doxorubicin within breast cancer-targeted poly (lactic-co-glycolic acid) (PLGA) nanoparticles, aiming to suppress NGF expression post-chemotherapy. Incorporating NGF blockade into the nanoplatform for chemotherapy effectively mitigated the chemotherapy-induced proliferation of sympathetic nerves. This not only bolstered the tumoricidal activity of chemotherapy, but also amplified its stimulatory impact on the antitumor immune response by increasing the infiltration of immunostimulatory cells into tumors while concurrently reducing the frequency of immunosuppressive cells. Consequently, the combined nanodrug approach, when coupled with anti-PD-L1 treatment, exhibited a remarkable suppression of primary and deeply metastatic tumors with minimal systematic toxicity. Importantly, the nanoplatform relieved chemotherapy-induced peripheral neuropathic pain (CIPNP) by diminishing the expression of pain mediator NGFs. In summary, this research underscores the significant potential of NGF knockdown in enhancing immunochemotherapy outcomes and presents a nanoplatform for the highly efficient and low-toxicity treatment of breast cancer.

12.
Artículo en Inglés | MEDLINE | ID: mdl-38758616

RESUMEN

Brain-computer interfaces (BCIs) have been widely focused and extensively studied in recent years for their huge prospect of medical rehabilitation and commercial applications. Transfer learning exploits the information in the source domain and applies in another different but related domain (target domain), and is therefore introduced into the BCIs to figure out the inter-subject variances of electroencephalography (EEG) signals. In this article, a novel transfer learning method is proposed to preserve the Riemannian locality of data structure in both the source and target domains and simultaneously realize the joint distribution adaptation of both domains to enhance the effectiveness of transfer learning. Specifically, a Riemannian graph is first defined and constructed based on the Riemannian distance to represent the Riemannian geometry information. To simultaneously align the marginal and conditional distribution of source and target domains and preserve the Riemannian locality of data structure in both domains, the Riemannian graph is embedded in the joint distribution adaptation (JDA) framework and forms the proposed Riemannian locality preserving-based transfer learning (RLPTL). To validate the effect of the proposed method, it is compared with several existing methods on two open motor imagery datasets, and both multi-source domains (MSD) and single-source domains (SSD) experiments are considered. Experimental results show that the proposed method achieves the highest accuracies in MSD and SSD experiments on three datasets and outperforms eight baseline methods, which demonstrates that the proposed method creates a feasible and efficient way to realize transfer learning.

13.
Plant Physiol ; 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38717740

RESUMEN

The circadian system plays a pivotal role in facilitating the ability of crop plants to respond and adapt to fluctuations in their immediate environment effectively. Despite the increasing comprehension of PSEUDO-RESPONSE REGULATORs (PRRs) and their involvement in the regulation of diverse biological processes, including circadian rhythms, photoperiodic control of flowering, and responses to abiotic stress, the transcriptional networks associated with these factors in soybean (Glycine max (L.) Merr.) remain incompletely characterized. In this study, we provide empirical evidence highlighting the significance of GmPRR3b as a crucial mediator in regulating the circadian clock, drought stress response, and abscisic acid (ABA) signaling pathway in soybeans. A comprehensive analysis of DNA affinity purification sequencing and transcriptome data identified 795 putative target genes directly regulated by GmPRR3b. Among them, a total of 570 exhibited a significant correlation with the response to drought, and eight genes were involved in both the biosynthesis and signaling pathways of ABA. Notably, GmPRR3b played a pivotal role in the negative regulation of the drought response in soybeans by suppressing the expression of abscisic acid responsive element-binding factor 3 (GmABF3). Additionally, the overexpression of GmABF3 exhibited an increased ability to tolerate drought conditions, and it also restored the hypersensitive phenotype of the GmPRR3b overexpressor. Consistently, studies on the manipulation of GmPRR3b gene expression and genome editing in plants revealed contrasting reactions to drought stress. The findings of our study collectively provide compelling evidence that emphasizes the significant contribution of the GmPRR3b-GmABF3 module in enhancing drought tolerance in soybean plants. Moreover, the transcriptional network of GmPRR3b provides valuable insights into the intricate interactions between this gene and the fundamental biological processes associated with plant adaptation to diverse environmental conditions.

14.
Dalton Trans ; 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38726731

RESUMEN

Constructing an environmentally friendly and efficient electrocatalyst holds important and profound significance for energy-efficient hydrogen production. Replacing the oxygen evolution reaction with a lower potential urea oxidation reaction (UOR) may save energy in water electrolysis to produce hydrogen. The UOR is characterized by its high energy barrier, which results in slow reaction kinetics. In this study, we introduced Ba(OH)2 into Ni(OH)2 to form uniform nanosheets. Due to the introduction of Ba2+, the lattice expansion of Ni(OH)2 was triggered, leading to significant improvement in UOR activity. The catalyst achieved a current density of 100 mA cm-2 at only 1.316 V and exhibited remarkable stability over time. Density functional theory (DFT) calculations demonstrate that the Ba-Ni(OH)2 site significantly reduces the energy barrier for urea adsorption, intermediate steps, and desorption. This work provides a novel and environmentally friendly strategy for constructing energy-efficient and highly efficient catalysts through the doping of alkaline earth metals.

15.
Water Res ; 257: 121678, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38692260

RESUMEN

The cost-effective treatment of sludge leachate (SL) with high nitrogen content and refractory dissolved organic matter (rDOM) has drawn increasing attention. This study employed, for the first time, a rDOM triggered denitratation-anammox continuous-flow process to treat landfill SL. Moreover, the mechanisms of exploiting rDOM from SL as an inner carbon source for denitratation were systematically analyzed. The results demonstrated outstanding nitrogen and rDOM removal performance without any external carbon source supplement. In this study, effluent concentrations of 4.27 ± 0.45 mgTIN/L and 5.58 ± 1.64 mgTN/L were achieved, coupled with an impressive COD removal rate of 65.17 % ± 1.71 %. The abundance of bacteria belonging to the Anaerolineaceae genus, which were identified as rDOM degradation bacteria, increased from 18.23 % to 35.62 %. As a result, various types of rDOM were utilized to different extents, with proteins being the most notable, except for lignins. Metagenomic analysis revealed a preference for directing electrons towards NO3--N reductase rather than NO2--N reductase, indicating the coupling of denitratation bacteria and anammox bacteria (Candidatus Brocadia). Overall, this study introduced a novel synergy platform for advanced nitrogen removal in treating SL using its inner carbon source. This approach is characterized by low energy consumption and operational costs, coupled with commendable efficiency.

16.
Water Res ; 257: 121675, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38692258

RESUMEN

Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have aroused great concern owing to their widespread occurrence and toxic effects. However, their long-term trends and multimedia fate remain largely unknown. Here, we investigate the spatiotemporal characteristics and periodic oscillations of PFOS and PFOA in the Elbe River between 2010 and 2021. Anthropogenic emission inventories and multimedia fugacity model were developed to analyse their historical and future transport fates and quantify related human risks in each medium for the three age groups. The results show that average PFOS and PFOA concentrations in the Elbe River were 4.08 and 3.41 ng/L, declining at the annual rate of 7.36% and 4.98% during the study period, respectively. Periodic oscillations of their concentrations and mass fluxes were most pronounced at 40-60 and 20-40 months. The multimedia fugacity model revealed that higher concentrations occurred in fish (PFOS: 14.29, PFOA: 0.40 ng/g), while the soil was their dominant sink (PFOS: 179, PFOA: 95 tons). The exchange flux between water and sediment was the dominant pathway in multimedia transportation (397 kg/year). Although PFOS and PFOA concentrations are projected to decrease by 22.41% and 50.08%, respectively, from 2021 to 2050, the hazard quotient of PFOS in fish is a low hazard. This study provides information for the assessment of PFOS and PFOA pollution in global watersheds and the development of related mitigation policies, such as banning fish predation in polluted rivers, to mitigate their risks.

17.
Sci Total Environ ; 931: 172949, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38703848

RESUMEN

Biodegradable plastics (bio-plastics) are often viewed as viable option for mitigating plastic pollution. Nevertheless, the information regarding the potential risks of microplastics (MPs) released from bio-plastics in soil, particularly in flooded soils, is lacking. Here, our objective was to investigate the effect of polylactic acid MPs (PLA-MPs) and polyethylene MPs (PE-MPs) on soil properties, microbial community and plant growth under both non-flooded and flooded conditions. Our results demonstrated that PLA-MPs dramatically increased soil labile carbon (C) content and altered its composition and chemodiversity. The enrichment of labile C stimulated microbial N immobilization, resulting in a depletion of soil mineral nitrogen (N). This specialized environment created by PLA-MPs further filtered out specific microbial species, resulting in a low diversity and simplified microbial community. PLA-MPs caused an increase in denitrifiers (Noviherbaspirillum and Clostridium sensu stricto) and a decrease in nitrifiers (Nitrospira, MND1, and Ellin6067), potentially exacerbating the mineral N deficiency. The mineral N deficit caused by PLA-MPs inhibited wheatgrass growth. Conversely, PE-MPs had less effect on soil ecosystems, including soil properties, microbial community and wheatgrass growth. Overall, our study emphasizes that PLA-MPs cause more adverse effect on the ecosystem than PE-MPs in the short term, and that flooded conditions exacerbate and prolong these adverse effects. These results offer valuable insights for evaluating the potential threats of bio-MPs in both uplands and wetlands.


Asunto(s)
Inundaciones , Microbiota , Microplásticos , Microbiología del Suelo , Contaminantes del Suelo , Suelo , Microplásticos/toxicidad , Suelo/química , Microbiota/efectos de los fármacos , Plásticos Biodegradables , Desarrollo de la Planta , Biodegradación Ambiental , Poliésteres , Polietileno
18.
Front Microbiol ; 15: 1361117, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38601932

RESUMEN

Tricholoma bakamatsutake is a delicious and nutritious ectomycorrhizal fungus. However, its cultivation is hindered owing to limited studies on its symbiotic relationships. The symbiotic relationship between T. bakamatsutake and its host is closely related to the shiro, a complex network composed of mycelium, mycorrhizal roots, and surrounding soil. To explore the symbiotic relationship between T. bakamatsutake and its host, soil samples were collected from T. bakamatsutake shiro (Tb) and corresponding Q. mongolica rhizosphere (CK) in four cities in Liaoning Province, China. The physicochemical properties of all the soil samples were then analyzed, along with the composition and function of the fungal and bacterial communities. The results revealed a significant increase in total potassium, available nitrogen, and sand in Tb soil compared to those in CK soil, while there was a significant decrease in pH, total nitrogen, total phosphorus, available phosphorus, and silt. The fungal community diversity in shiro was diminished, and T. bakamatsutake altered the community structure of its shiro by suppressing other fungi, such as Russula (ectomycorrhizal fungus) and Penicillium (phytopathogenic fungus). The bacterial community diversity in shiro increased, with the aggregation of mycorrhizal-helper bacteria, such as Paenibacillus and Bacillus, and plant growth-promoting bacteria, such as Solirubrobacter and Streptomyces, facilitated by T. bakamatsutake. Microbial functional predictions revealed a significant increase in pathways associated with sugar and fat catabolism within the fungal and bacterial communities of shiro. The relative genetic abundance of carboxylesterase and gibberellin 2-beta-dioxygenase in the fungal community was significantly increased, which suggested a potential symbiotic relationship between T. bakamatsutake and Q. mongolica. These findings elucidate the microbial community and relevant symbiotic environment to better understand the relationship between T. bakamatsutake and Q. mongolica.

19.
IEEE Trans Biomed Eng ; PP2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38602850

RESUMEN

OBJECTIVE: The information transfer rate (ITR) is widely accepted as a performance metric for generic brain-computer interface (BCI) spellers, while it is noticeable that the communication speed given by ITR is actually an upper bound which however can never be reached in real systems. A new performance metric is therefore needed. METHODS: In this paper, a new metric named average time consumption per character (ATCPC) is proposed. It quantifies how long it takes on average to type one character using a typical synchronous BCI speller. To analytically derive ATCPC, the real typing process is modelled with a random walk on a graph. Misclassification and backspace are carefully characterized. A close-form formula of ATCPC is obtained through computing the hitting time of the random walk. The new metric is validated through simulated typing experiments and compared with ITR. RESULTS: Firstly, the formula and simulation show a good consistency. Secondly, ITR always tends to overestimate the communication speed, while ATCPC is more realistic. CONCLUSION: The proposed ATCPC metric is valid. SIGNIFICANCE: ATCPC is a qualified substitute for ITR. ATCPC also reveals the great potential of keyboard optimization to further enhance the performance of BCI spellers, which was hardly investigated before.

20.
ACS Nano ; 18(19): 12453-12467, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38686995

RESUMEN

Traditional magnetic resonance imaging (MRI) contrast agents (CAs) are a type of "always on" system that accelerates proton relaxation regardless of their enrichment region. This "always on" feature leads to a decrease in signal differences between lesions and normal tissues, hampering their applications in accurate and early diagnosis. Herein, we report a strategy to fabricate glutathione (GSH)-responsive one-dimensional (1-D) manganese oxide nanoparticles (MONPs) with improved T2 relaxivities and achieve effective T2/T1 switchable MRI imaging of tumors. Compared to traditional contrast agents with high saturation magnetization to enhance T2 relaxivities, 1-D MONPs with weak Ms effectively increase the inhomogeneity of the local magnetic field and exhibit obvious T2 contrast. The inhomogeneity of the local magnetic field of 1-D MONPs is highly dependent on their number of primary particles and surface roughness according to Landau-Lifshitz-Gilbert simulations and thus eventually determines their T2 relaxivities. Furthermore, the GSH responsiveness ensures 1-D MONPs with sensitive switching from the T2 to T1 mode in vitro and subcutaneous tumors to clearly delineate the boundary of glioma and metastasis margins, achieving precise histopathological-level MRI. This study provides a strategy to improve T2 relaxivity of magnetic nanoparticles and construct switchable MRI CAs, offering high tumor-to-normal tissue contrast signal for early and accurate diagnosis.


Asunto(s)
Medios de Contraste , Imagen por Resonancia Magnética , Compuestos de Manganeso , Compuestos de Manganeso/química , Compuestos de Manganeso/farmacología , Animales , Ratones , Medios de Contraste/química , Humanos , Campos Magnéticos , Glutatión/química , Óxidos/química , Línea Celular Tumoral , Glioma/diagnóstico por imagen , Glioma/patología , Tamaño de la Partícula , Nanopartículas de Magnetita/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...