Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 180
Filtrar
1.
Adv Healthc Mater ; : e2401788, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864814

RESUMO

Coated microneedles (CMNs) are a minimally invasive platform for immediate-release transdermal drug delivery. However, the practical applications of CMNs have been significantly hindered by the challenges associated with complex formulations, single function, and limited drug loading capacity. In this study, we have developed a spiderweb-shaped iron-coordinated polymeric nanowire network (Fe-IDA NWs). The resulting Fe-IDA NWs are endowed with a certain viscosity due to the synergy of multiple supramolecular interactions. This allows them to replace traditional polymeric thickeners as microneedle coatings. The Fe-IDA NWs-coated microneedles (Fe-IDA MNs) display rapid disintegration in the skin model, which also enables the swift diffusion of Fe-IDA NWs and their payloads into the deeper skin layers. Additionally, Fe-IDA MNs exhibit desirable enzymatic activity and potential antibacterial ability. Thus, Fe-IDA MNs can enhance the therapeutic efficacy against wound infection through synergistic effects, and avoid the overly complicated formulation and the release of non-therapeutic molecules of conventional CMNs. As a proof-of-concept, Fe-IDA MNs loaded with chlorin e6 showed a synergistic chemodynamic-photodynamic antibacterial effect in a methicillin-resistant Staphylococcus aureus-infected wound model in mice. Collectively, this work has significant implications for the future of CMNs-based transdermal drug delivery systems and expands the application fields of metal coordination polymer materials. This article is protected by copyright. All rights reserved.

2.
Environ Pollut ; 355: 124210, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38795815

RESUMO

Pesticide residue and thermal stress resulting from global climate change are parallel stressors for soil fauna. However, it remains ambiguous how elevated temperatures and pesticides can interact to threaten soil fauna. In the study, the acute and chronic clothianidin (CTD) toxicity to earthworms (Eisenia fetida) at different temperatures, and the effect of increasing temperature on antioxidant defense mechanisms in response to CTD were investigated. The acute toxicity of CTD was exacerbated by increased temperature in both filter paper contact tests (a decrease in the 48-h median lethal concentration (LC50) from 0.077 µg/cm2 at 20 °C to 0.009 µg/cm2 at 30 °C) and natural soil tests (a decrease in the 48-h LC50 from 0.774 mg/kg at 20 °C to 0.199 mg/kg at 30 °C). Exposure to CTD or high temperature (30 °C) triggered reactive oxygen species (ROS) overgeneration and increased antioxidant enzyme activities in earthworms; and the effect was particularly pronounced after exposure to both higher temperatures and CTD. At 20 and 25 °C, there was no significant change in the growth and reproduction of E. fetida after 56-d exposure to CTD-contaminated soil. However, the combined effect of CTD and high temperature (30 °C) significantly reduced the weight change rate, cocoon number, hatching rate, and number of juveniles on day 56. These results indicated that elevated temperature could aggravate acute and chronic CTD toxicity to earthworms. The findings emphasize that evaluating changes in pesticide toxicity under global warming is worth further investigation.


Assuntos
Guanidinas , Neonicotinoides , Oligoquetos , Poluentes do Solo , Tiazóis , Oligoquetos/efeitos dos fármacos , Animais , Neonicotinoides/toxicidade , Guanidinas/toxicidade , Tiazóis/toxicidade , Poluentes do Solo/toxicidade , Inseticidas/toxicidade , Temperatura Alta , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Solo/química
3.
Sci Total Environ ; 928: 172444, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38615769

RESUMO

The development of antibiotic resistance threatens human and environmental health. Non-antibiotic stressors, including fungicides, may contribute to the spread of antibiotic resistance genes (ARGs). We determined the promoting effects of tebuconazole on ARG dissemination using a donor, Escherichia coli MG1655, containing a multidrug-resistant fluorescent plasmid (RP4) and a recipient (E. coli HB101). The donor was then incorporated into the soil to test whether tebuconazole could accelerate the spread of RP4 into indigenous bacteria. Tebuconazole promoted the transfer of the RP4 plasmid from the donor into the recipient via overproduction of reactive oxygen species (ROS), enhancement of cell membrane permeability and regulation of related genes. The dissemination of the RP4 plasmid from the donor to soil bacteria was significantly enhanced by tebuconazole. RP4 plasmid could be propagated into more genera of bacteria in tebuconazole-contaminated soil as the exposure time increased. These findings demonstrate that the fungicide tebuconazole promotes the spread of the RP4 plasmid into indigenous soil bacteria, revealing the potential risk of tebuconazole residues enhancing the dissemination of ARGs in soil environments.


Assuntos
Fungicidas Industriais , Plasmídeos , Microbiologia do Solo , Poluentes do Solo , Triazóis , Plasmídeos/genética , Triazóis/toxicidade , Poluentes do Solo/toxicidade , Fungicidas Industriais/toxicidade , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética
4.
Artigo em Inglês | MEDLINE | ID: mdl-38587950

RESUMO

As a challenging computer vision task, Scene Graph Generation (SGG) finds the latent semantic relationships among objects from a given image, which may be limited by the datasets and real-world scenarios. In this paper, we consider a novel incremental learning task called Relationship-Incremental Scene Graph Generation (RISGG) that learns the semantic relationships among objects in an incremental way. Compared with classic Class-Incremental Learning (CIL) problem, RISGG suffers from its special issues: (1) Old class shift - the relationship-labeled object pair may have different labels during different learning sessions. (2) Background shift - the relationship-unlabeled object pair may not be a real unlabeled one. In this work, we address the above issues from the following aspects. First, we present a Divide-and-Conquer (DaC) pipeline to deal with the old class shift via decoupling the recognition of relationship classes and recognizing relationships individually. In this way, label confusion and interaction among different relationships are eliminated during training. Second, we propose a Feature Adapter (FA) to bridge the feature space gap between the current session and the previous one and use our extra supervision to mine old relationship information in the current session. Our proposed network combined DaC and FA, abbreviated DaCFA-Net, for RISGG. Experimental results on the benchmark dataset demonstrate the significant performance gain of DaCFA-Net in RISGG. It gains about 20% improvement against the SGG baselines on the popular VG dataset.

5.
Neural Netw ; 174: 106215, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38471261

RESUMO

Deep neural networks tend to suffer from the overfitting issue when the training data are not enough. In this paper, we introduce two metrics from the intra-class distribution of correct-predicted and incorrect-predicted samples to provide a new perspective on the overfitting issue. Based on it, we propose a knowledge distillation approach without pretraining a teacher model in advance named Tolerant Self-Distillation (TSD) for alleviating the overfitting issue. It introduces an online updating memory and selectively stores the class predictions of the samples from the past iterations, making it possible to distill knowledge across the iterations. Specifically, the class predictions stored in the memory bank serve as the soft labels for supervising the samples from the same class for the current iteration in a reverse way, i.e. the correct-predicted samples are supervised with the incorrect predictions while the incorrect-predicted samples are supervised with the correct predictions. Consequently, the premature convergence issue caused by the over-confident samples would be mitigated, which helps the model to converge to a better local optimum. Extensive experimental results on several image classification benchmarks, including small-scale, large-scale, and fine-grained datasets, demonstrate the superiority of the proposed TSD.


Assuntos
Benchmarking , Conhecimento , Redes Neurais de Computação
6.
Environ Sci Technol ; 58(6): 2931-2943, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38306257

RESUMO

From a "One Health" perspective, the global threat of antibiotic resistance genes (ARGs) is associated with modern agriculture practices including agrochemicals application. Chiral fungicides account for a considerable proportion of wildly used agrochemicals; however, whether and how their enantiomers lead to differential proliferation of antibiotic resistance in agricultural environments remain overlooked. Focused on the soil-earthworm ecosystem, we for the first time deciphered the mechanisms underlying the enantioselective proliferation of antibiotic resistance driven by the enantiomers of a typical chiral fungicide mandipropamid (i.e., R-MDP and S-MDP) utilizing a multiomic approach. Time-series metagenomic analysis revealed that R-MDP led to a significant enhancement of ARGs with potential mobility (particularly the plasmid-borne ARGs) in the earthworm intestinal microbiome. We further demonstrated that R-MDP induced a concentration-dependent facilitation of plasmid-mediated ARG transfer among microbes. In addition, transcriptomic analysis with verification identified the key aspects involved, where R-MDP enhanced cell membrane permeability, transfer ability, biofilm formation and quorum sensing, rebalanced energy production, and decreased cell mobility versus S-MDP. Overall, the findings provide novel insights into the enantioselective disruption of microbiome and resistome in earthworm gut by chiral fungicides and offer significant contributions to the comprehensive risk assessment of chiral agrochemicals in agroecosystems.


Assuntos
Fungicidas Industriais , Microbioma Gastrointestinal , Oligoquetos , Animais , Oligoquetos/genética , Fungicidas Industriais/farmacologia , Fungicidas Industriais/análise , Genes Bacterianos , Ecossistema , Estereoisomerismo , Resistência Microbiana a Medicamentos/genética , Solo , Antibacterianos/farmacologia , Proliferação de Células
7.
Adv Sci (Weinh) ; 11(17): e2306602, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38350733

RESUMO

Wounds infected with multidrug-resistant (MDR) bacteria are increasingly threatening public health and challenging clinical treatments because of intensive bacterial colonization, excessive inflammatory responses, and superabundant oxidative stress. To overcome this malignant burden and promote wound healing, a multifunctional cryogel (HA/TA2/KR2) composed of hyaluronic acid (HA), tannic acid (TA), and KR-12 peptides is designed. The cryogel exhibited excellent shape-memory properties, strong absorption performance, and hemostatic capacity. In vitro experiments demonstrated that KR-12 in the cryogel can be responsively released by stimulation with hyaluronidase produced by bacteria, reaching robust antibacterial activity against Escherichia coli (E. coli), MDR Pseudomonas aeruginosa (MDR-PA), and methicillin-resistant Staphylococcus aureus (MRSA) by disrupting bacterial cell membranes. Furthermore, the synergetic effect of KR-12 and TA can efficiently scavenge ROS and decrease expression of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α & interleukin (IL)-6), as well as modulate the macrophage phenotype toward the M2 type. In vivo animal tests indicated that the cryogel can effectively destroy bacteria in the wound and promote healing process via accelerating angiogenesis and re-epithelialization. Proteomic analysis revealed the underlying mechanism by which the cryogel mainly reshaped the infected wound microenvironment by inhibiting the Nuclear factor kappa B (NF-κB) signaling pathway and activating the Janus kinase-Signal transducer and activator of transcription (JAK-STAT6) signaling pathway. Therefore, the HA/TA2/KR2 cryogel is a promising dressing candidate for MDR bacteria-infected wound healing.


Assuntos
Antibacterianos , Criogéis , Modelos Animais de Doenças , Hialuronoglucosaminidase , Espécies Reativas de Oxigênio , Cicatrização , Animais , Camundongos , Antibacterianos/farmacologia , Criogéis/farmacologia , Criogéis/química , Escherichia coli/efeitos dos fármacos , Ácido Hialurônico/farmacologia , Hialuronoglucosaminidase/metabolismo , Inflamação/tratamento farmacológico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Cicatrização/efeitos dos fármacos , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Camundongos Endogâmicos BALB C
8.
Biomed J ; 47(1): 100605, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37179010

RESUMO

BACKGROUND: Curcumin ameliorates bone loss by inhibiting osteoclastogenesis. Curcumin inhibits RANKL-promoted autophagy in osteoclast precursors (OCPs), which mediates its anti-osteoclastogenic effect. But the role of RANKL signaling in curcumin-regulated OCP autophagy is unknown. This study aimed to explore the relationship between curcumin, RANKL signaling, and OCP autophagy during osteoclastogenesis. METHODS: We investigated the role of curcumin in RANKL-related molecular signaling in OCPs, and identified the significance of RANK-TRAF6 signaling in curcumin-treated osteoclastogenesis and OCP autophagy using flow sorting and lentiviral transduction. Tg-hRANKL mice were used to observe the in vivo effects of curcumin on RANKL-regulated bone loss, osteoclastogenesis, and OCP autophagy. The significance of JNK-BCL2-Beclin1 pathway in curcumin-regulated OCP autophagy with RANKL was explored via rescue assays and BCL2 phosphorylation detection. RESULTS: Curcumin inhibited RANKL-related molecular signaling in OCPs, and repressed osteoclast differentiation and autophagy in sorted RANK+ OCPs but did not affect those of RANK- OCPs. Curcumin-inhibited osteoclast differentiation and OCP autophagy were recovered by TRAF6 overexpression. But curcumin lost these effects under TRAF6 knockdown. Furthermore, curcumin prevented the decrease in bone mass and the increase in trabecular osteoclast formation and autophagy in RANK+ OCPs in Tg-hRANKL mice. Additionally, curcumin-inhibited OCP autophagy with RANKL was reversed by JNK activator anisomycin and TAT-Beclin1 overexpressing Beclin1. Curcumin inhibited BCL2 phosphorylation at Ser70 and enhanced protein interaction between BCL2 and Beclin1 in OCPs. CONCLUSIONS: Curcumin suppresses RANKL-promoted OCP autophagy by inhibiting signaling pathway downstream of RANKL, contributing to its anti-osteoclastogenic effect. Moreover, JNK-BCL2-Beclin1 pathway plays an important role in curcumin-regulated OCP autophagy.


Assuntos
Curcumina , Osteoclastos , Animais , Camundongos , Autofagia , Proteína Beclina-1/metabolismo , Diferenciação Celular , Curcumina/farmacologia , Curcumina/metabolismo , Osteogênese , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Fator 6 Associado a Receptor de TNF/metabolismo
9.
Artigo em Inglês | MEDLINE | ID: mdl-37922165

RESUMO

In Few-Shot Learning (FSL), the objective is to correctly recognize new samples from novel classes with only a few available samples per class. Existing methods in FSL primarily focus on learning transferable knowledge from base classes by maximizing the information between feature representations and their corresponding labels. However, this approach may suffer from the "supervision collapse" issue, which arises due to a bias towards the base classes. In this paper, we propose a solution to address this issue by preserving the intrinsic structure of the data and enabling the learning of a generalized model for the novel classes. Following the InfoMax principle, our approach maximizes two types of mutual information (MI): between the samples and their feature representations, and between the feature representations and their class labels. This allows us to strike a balance between discrimination (capturing class-specific information) and generalization (capturing common characteristics across different classes) in the feature representations. To achieve this, we adopt a unified framework that perturbs the feature embedding space using two low-bias estimators. The first estimator maximizes the MI between a pair of intra-class samples, while the second estimator maximizes the MI between a sample and its augmented views. This framework effectively combines knowledge distillation between class-wise pairs and enlarges the diversity in feature representations. By conducting extensive experiments on popular FSL benchmarks, our proposed approach achieves comparable performances with state-of-the-art competitors. For example, we achieved an accuracy of 69.53% on the miniImageNet dataset and 77.06% on the CIFAR-FS dataset for the 5-way 1-shot task.

10.
Exp Biol Med (Maywood) ; 248(20): 1732-1744, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37750023

RESUMO

Triiodothyronine (T3) is critical to osteogenesis, which is the key factor in bone growth. Our transcriptomic and metabolomic analysis results indicated that T3 leads to enhanced expression of G protein-coupled estrogen receptor 1 (GPER1) as well as increases in glycolysis metabolite levels. Accordingly, our study aimed to explore the role of GPER1-mediated glycolysis in T3-regulated osteogenesis. The MC3T3-E1 cell line was used as an osteoblast precursor model. After treatment with T3, a GPER1-specific antagonist (G15) and inhibitor of glycolysis (3PO) were used to explore the roles of GPER1 and glycolysis in T3-regulated osteogenesis, as measured by ALP activity, Alizarin red staining intensity and osteogenic molecule expression. Our results showed that T3 promoted osteogenesis-related activity, which was reversed by treatment with G15. In addition, T3 enhanced the glycolytic potential and production of lactic acid (LD) in MC3T3-E1 cells, and treatment with G15 restored the aforementioned effects of T3. Ultimately, the pharmacological inhibition of glycolysis with 3PO blocked the ability of T3 to enhance osteogenic activities. In conclusion, GPER1 mediates glycolysis in osteoblast precursors, which is critical for T3-promoted osteogenesis.


Assuntos
Osteoblastos , Osteogênese , Diferenciação Celular , Linhagem Celular , Osteoblastos/metabolismo , Animais , Camundongos
11.
Sci Total Environ ; 903: 166655, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37647951

RESUMO

In nature, aquatic organisms may suffer from chemical pollution, together with thermal stress resulted from global warming. However, limited information is available on the combined effects of pesticide with climate change on aquatic organisms. In this study, the acute toxicity of clothianidin to Limnodrilus hoffmeisteri as well as its effect on the induction of oxidative stress under both constant temperature and daily temperature fluctuation (DTF) regimes was investigated. Results showed that clothianidin exhibited the minimal toxicity to L. hoffmeisteri at 25 °C, which was magnified by both increased or decreased temperatures and 10 °C DTF. At different temperatures (15 °C, 25 °C and 35 °C), clothianidin exposure led to the elevated reactive oxygen species (ROS) levels and activated the antioxidant enzymes to resist against the oxidative stress. However, the antioxidant response induced by clothianidin was overwhelmed at high temperature as evidenced by decreased glutathione (GSH) content. Significant elevation of catalase (CAT) and peroxidase (POD) activities but depletion of GSH was also observed in worms treated with clothianidin under DTF after 24 h. The results indicated that high temperature and DTF could aggravate the clothianidin-induced oxidative stress. Moreover, the critical thermal maximum (CTmax) of the worms decreased with the increasing clothianidin concentrations, suggesting that exposure to clothianidin could reduce the heat tolerance of L. hoffmeisteri. Our work highlights the crucial importance to integrate temperature changes into risk assessment of pesticides under global warming.

12.
J Orthop Surg Res ; 18(1): 598, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37574567

RESUMO

OBJECTIVE: Spinal schwannomas (SS) and spinal meningiomas (SM) account for most intradural extramedullary (IDEM) tumors. These tumors are usually benign lesions, which generally respond favorably to surgical excision. Few studies up to now tried to determine the long-term outcome after minimally invasive surgery (MIS) with multimodal intraoperative neurophysiological monitoring (IONM) for IDEM tumors. The aim of this study was to present one of the largest case series with special regard to IONM findings and long-term outcome after MIS-keyhole surgery with a tubular retractor system. METHODS: Between January 2013 and August 2018, 87 patients with IDEM tumors who underwent tumor removal surgery via MIS-keyhole approach under multimodal IONM were retrospectively reviewed. The neurological status was assessed using a modified McCormick grading scale pre- and postoperatively. Multimodal IONM consisted of motor evoked potentials (MEP), somatosensory evoked potentials (SEP), and electromyography (EMG). Both short-term and long-term clinical evaluations as well as patients' medical files were retrospectively analyzed. RESULTS: Surgeries were performed for resection of SS in 49 patients and SM in 38 patients. Tumor locations were cervical in 16.1%, thoracic in 48.3%, thoracolumbar in 4.6%, lumbar 31%. Critical IONM changes were detected in 9 operations (10.3%) in which there were 2 SEPs, 5 MEPs, and 2 EMG events. Three IONM changes (2 MEPs, 1 EMG) were turned out to be transient change in nature since they were resolved in a short time when immediate corrective actions were initiated. Six patients with permanent IONM changes (2SEPs, 3MEPs, 1EMG event), all deficits had resolved during hospitalization or on short -term follow-up evaluation. Sensitivity, specificity, and positive and negative predicted values of IONM were 100, 96, 67, and 100%, respectively. Gross total resection rate was 100%, and a stable or improved McCormick grade exhibited in all patients. No tumor recurrence and no spinal instability were found in the long-term follow-up evaluation (mean 5.2 ± 2.9 years postoperatively). Overall, 94% of patients were either satisfied or very satisfied with their operation, and 93% patients reported excellent or good general clinical outcome according to Odom's criteria. CONCLUSION: MIS-keyhole surgery with multimodal IONM for IDEM tumors enables a high level of satisfaction and a satisfying long-term clinical and surgical outcome.


Assuntos
Monitorização Neurofisiológica Intraoperatória , Neoplasias da Medula Espinal , Neoplasias da Coluna Vertebral , Humanos , Estudos Retrospectivos , Recidiva Local de Neoplasia , Neoplasias da Medula Espinal/cirurgia , Procedimentos Neurocirúrgicos , Neoplasias da Coluna Vertebral/cirurgia
13.
Small ; 19(44): e2303251, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37376823

RESUMO

In this paper, strong hydrophilic poly(ionic liquid)s (PILs) are selectively grafted on different positions (mesoporous channels and outer surface) of mesoporous silica via thiol-ene click chemical reaction. The purposes of selective grafting are on the one hand, to explore the differences of adsorption and transportation of water molecules in mesoporous channels and on the outer surface, and on the other hand, to combine the two approaches (intra-pore grafting and external surface grafting) to reasonably design SiO2 @PILs low humidity sensing film with synergetic function to achieve high sensitivity. The results of low relativehumidity (RH) sensing test show that the sensing performance of humidity sensor based on mesoporous silica grafted with PILs in the channels is better than that of humidity sensor based on mesoporous silica grafted with PILs on the outer surface. Compared with water molecules transport single channel, the construction of dual-channel water transport significantly improves the sensitivity of the low humidity sensor, and the response of the sensor is up to 4112% in the range of 7-33% RH. Moreover, the existence of micropores and the formation of dual-channel water transport affect the adsorption/desorption behaviors of the sensor under different humidity ranges, especially below 11% RH.

14.
Pest Manag Sci ; 79(10): 3926-3933, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37245216

RESUMO

BACKGROUND: The insecticide carbosulfan is usually applied as a soil treatment or seed-coating agent, and so may be absorbed by crops and pose dietary risks. Understanding the uptake, metabolism and translocation of carbosulfan in crops is conducive to its safe application. In this study, we investigated the distribution of carbosulfan and its toxic metabolites in maize plants at both the tissue and subcellular levels, and explored the uptake and translocation mechanism of carbosulfan. RESULTS: Carbosulfan was mainly taken up by maize roots via the apoplast pathway, was preferentially distributed in cell walls (51.2%-57.0%) and most (85.0%) accumulated in roots with only weak upward translocation. Carbofuran, the main metabolite of carbosulfan in maize plants, was primarily stored in roots. However, carbofuran could be upwardly translocated to shoots and leaves because of its greater distribution in root-soluble components (24.4%-28.5%) compared with carbosulfan (9.7%-14.5%). This resulted from its greater solubility compared with its parent compound. The metabolite 3-hydroxycarbofuran was found in shoots and leaves. CONCLUSION: Carbosulfan could be passively absorbed by maize roots, mainly via the apoplastic pathway, and transformed into carbofuran and 3-hydroxycarbofuran. Although carbosulfan mostly accumulated in roots, its toxic metabolites carbofuran and 3-hydroxycarbofuran could be detected in shoots and leaves. This implies that there is a risk in the use of carbosulfan as a soil treatment or seed coating. © 2023 Society of Chemical Industry.


Assuntos
Carbofurano , Carbofurano/metabolismo , Zea mays/metabolismo , Carbamatos/metabolismo , Raízes de Plantas/metabolismo
15.
J Hazard Mater ; 455: 131559, 2023 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-37163893

RESUMO

The high abundance of antibiotic resistance genes (ARGs) in the fungicide residual environment, posing a threat to the environment and human health, raises the question of whether and how fungicide promotes the prevalence and dissemination of antibiotic resistance. Here, we reported a novel mechanism underlying bidirectional regulation of a typical heavy-metal-containing fungicide mancozeb on the horizontal transfer of ARGs. Our findings revealed that mancozeb exposure significantly exerted oxidative and osmotic stress on the microbes and facilitated plasmid-mediated ARGs transfer, but its metallic portions (Mn and Zn) were potentially utilized as essential ions by microbes for metalating enzymes to deal with cellular stress and thus reduce the transfer. The results of transcriptome analysis with RT-qPCR confirmed that the expression levels of cellular stress responses and conjugation related genes were drastically altered. It can be concluded mancozeb bidirectionally regulated the ARGs dissemination which may be attributed to the diverse effects on the microbes by its different portions. This novel mechanism provides an updated understanding of neglected fungicide-triggered ARGs dissemination and crucial insight for comprehensive risk assessment of fungicides.


Assuntos
Fungicidas Industriais , Maneb , Metais Pesados , Zineb , Humanos , Resistência Microbiana a Medicamentos/genética , Maneb/toxicidade , Zineb/toxicidade , Genes Bacterianos , Fungicidas Industriais/toxicidade , Antibacterianos/farmacologia
16.
Water Res ; 233: 119789, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36863279

RESUMO

Co-pollution of soil with pesticide residues and antibiotic resistance genes (ARGs) is increasing due to the substantial usage of pesticides and organic fertilizers in greenhouse-based agricultural production. Non-antibiotic stresses, including those from agricultural fungicides, are potential co-selectors for the horizontal transfer of ARGs, but the underlying mechanism remains unclear. Intragenus and intergenus conjugative transfer systems of the antibiotic resistant plasmid RP4 were established to examine conjugative transfer frequency under stress from four widely used fungicides: triadimefon, chlorothalonil, azoxystrobin, and carbendazim. The mechanisms were elucidated at the cellular and molecular levels using transmission electron microscopy, flow cytometry, RT-qPCR, and RNA-seq techniques. The conjugative transfer frequency of plasmid RP4 between Escherichia coli strains increased with the rising exposure concentrations of chlorothalonil, azoxystrobin, and carbendazim, but was suppressed between E. coli and Pseudomonas putida by a high fungicide concentration (10 µg/mL). Triadimefon did not significantly affect conjugative transfer frequency. Exploration of the underlying mechanisms revealed that: (i) chlorothalonil exposure mainly promoted generation of intracellular reactive oxygen species, stimulated the SOS response, and increased cell membrane permeability, while (ii) azoxystrobin and carbendazim primarily enhanced expression of conjugation-related genes on the plasmid. These findings reveal the fungicide-triggered mechanisms associated with plasmid conjugation and highlight the potential role of non-bactericidal pesticides on the dissemination of ARGs.


Assuntos
Antibacterianos , Fungicidas Industriais , Antibacterianos/farmacologia , Escherichia coli/genética , Genes Bacterianos , Resistência Microbiana a Medicamentos/genética , Plasmídeos/genética , Transferência Genética Horizontal
17.
Cell Prolif ; 56(8): e13426, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36786008

RESUMO

Osteoporotic fracture is a major health problem plaguing the ageing society, and improving its treatment is an urgent challenge. How to ameliorate bone loss determines the recovery of such fractures. Extracellular vesicle (EV)-loaded hydrogel has the capacity to treat osteoporotic fractures due to its pro-osteogenic property. And balancing proliferation and maturation of osteoblast precursors (OBPs) is of great significance to avoid OBP depletion, which is lacking in current treatment. Based on osteoblastogenic miRNAs, this study aimed to explore the efficacies of the combination of hierarchical hydrogel and EVs altering functional miRNAs level in bone loss. Through bioinformatics analyses, we screened out proliferative gene-targeting miR-200b-3p and osteogenic gene-targeting miR-130b-3p. And antagomiR-200b-3p (ant-200b) enhanced OBP proliferation, and antagomiR-130b-3p (ant-130b) promoted OBP differentiation. After confirming the directional effect of Fibronectin (Fn1) on OBPs, we prepared OBP-targeting EVs. Furthermore, encapsulation of two antagomiRNAs in EVs enhanced the respective effect of ant-200b and ant-130b. Notably, hierarchically injectable hydrogel exerted an effective function in promoting the sequential delivery of EVs-200b and EVs-130b. Importantly, hierarchical hydrogel containing dual EVs effectively ameliorated bone loss. Overall, hierarchical hydrogel based on two antagomiRNAs effectively improves bone loss in vivo due to its role in promoting OBP proliferation and maturation sequentially.


Assuntos
Doenças Ósseas Metabólicas , Vesículas Extracelulares , MicroRNAs , Humanos , Antagomirs , Hidrogéis/farmacologia , MicroRNAs/genética , Osteoblastos
18.
IEEE Trans Neural Netw Learn Syst ; 34(6): 3183-3194, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34587096

RESUMO

In this article, we present a conceptually simple but effective framework called knowledge distillation classifier generation network (KDCGN) for zero-shot learning (ZSL), where the learning agent requires recognizing unseen classes that have no visual data for training. Different from the existing generative approaches that synthesize visual features for unseen classifiers' learning, the proposed framework directly generates classifiers for unseen classes conditioned on the corresponding class-level semantics. To ensure the generated classifiers to be discriminative to the visual features, we borrow the knowledge distillation idea to both supervise the classifier generation and distill the knowledge with, respectively, the visual classifiers and soft targets trained from a traditional classification network. Under this framework, we develop two, respectively, strategies, i.e., class augmentation and semantics guidance, to facilitate the supervision process from the perspectives of improving visual classifiers. Specifically, the class augmentation strategy incorporates some additional categories to train the visual classifiers, which regularizes the visual classifier weights to be compact, under supervision of which the generated classifiers will be more discriminative. The semantics-guidance strategy encodes the class semantics into the visual classifiers, which would facilitate the supervision process by minimizing the differences between the generated and the real-visual classifiers. To evaluate the effectiveness of the proposed framework, we have conducted extensive experiments on five datasets in image classification, i.e., AwA1, AwA2, CUB, FLO, and APY. Experimental results show that the proposed approach performs best in the traditional ZSL task and achieves a significant performance improvement on four out of the five datasets in the generalized ZSL task.

19.
J Stroke Cerebrovasc Dis ; 32(1): 106896, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36395661

RESUMO

AIM: To investigate the influence of dexmedetomidine (Dex) on cerebral ischemia/reperfusion (I/R)-injured rat neuronal cells by regulating the Sphk1/S1P pathway. METHODS: The rats were divided into the following groups, with 18 rats in each group categorized on the basis of random number tables: sham (Sham), I/R (I/R), Dex, Sphk1 inhibitor (PF-543), and Dex together with the Sphk1 agonist phorbol-12-myristate-13-acetate (Dex+PMA). The neurological functions of the rats were assessed by the Longa scoring system at 24 h post reperfusion. The area of brain infarction was inspected using 2,3,5-triphenyltetrazolium chloride staining, and the water content of brain tissue was determined by the dry-wet weight method. The morphology of neurons in the CA1 region of the rat hippocampus was inspected using Nissl staining, while the apoptosis of neurons in this region was detected by terminal-deoxynucleotidyl transferase mediated nick end labeling staining. The Sphk1 and S1P protein levels were determined by immunofluorescence and western blotting, respectively. RESULTS: Compared to the I/R group, rats in the Dex, PF-543, and Dex+PMA groups had a significantly lower neurological function score, as well as lower brain water content and a decreased infarction area. Moreover, the apoptotic index of the neurons and the Sphk1 and S1P levels in the hippocampal CA1 region were significantly lower in these groups (p<0.05). PMA, an agonist of Sphk1, was able to reverse the protective effects of Dex on I/R-induced neuronal cell injury. CONCLUSION: Dex could protect cerebral I/R-induced neuronal cell injury by suppressing the Sphk1/S1P signaling pathway.


Assuntos
Isquemia Encefálica , Dexmedetomidina , Traumatismo por Reperfusão , Animais , Ratos , Apoptose , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Região CA1 Hipocampal/metabolismo , Infarto Cerebral , Dexmedetomidina/farmacologia , Neurônios/metabolismo , Ratos Sprague-Dawley , Reperfusão , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais
20.
Pest Manag Sci ; 79(2): 560-568, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36205310

RESUMO

BACKGROUND: Triazole resistance in the human fungal pathogen Aspergillus fumigatus has been a growing challenge in clinic treatment with triazole drugs such as itraconazole. The fast evolvement of triazole resistance in A. fumigatus in the ecosystem has drawn great attention, and there has been a possible link between the application of triazole fungicides in agriculture and triazole resistance in A. fumigatus. The change in susceptibility of A. fumigatus exposed to the new chiral triazole fungicide mefentrifluconazole was investigated in this study. RESULTS: The results indicated that triazole resistance in A. fumigatus was acquired with exposure to mefentrifluconazole at a level of greater than or equal to 2 mg L-1 in liquid medium and soil (not at 0.4 nor 1 mg L-1 ). Interestingly, stereoselectivity was found in the acquisition of triazole resistance in A. fumigatus when exposed to mefentrifluconazole. R-mefentrifluconazole, which is very active on plant pathogens, exhibited stronger possibility in the development of the resistance in A. fumigatus than its antipode. Overexpression of cyp51A, AtrF, AfuMDR1 and AfuMDR4 were associated with the acquired resistance in A. fumigatus with hereditary stability. CONCLUSION: The results suggest that triazole resistance in A. fumigatus could be resulted from the selection of mefentrifluconazole at concentrations larger than 2 mg L-1 . Mefentrifluconazole should be applied within the dosage recommended by good agricultural practice to avoid the resistance in A. fumigatus in soil. This also may be applicable to other triazole fungicides. © 2022 Society of Chemical Industry.


Assuntos
Aspergillus fumigatus , Farmacorresistência Fúngica , Fungicidas Industriais , Triazóis , Humanos , Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Farmacorresistência Fúngica/genética , Ecossistema , Proteínas Fúngicas/genética , Fungicidas Industriais/farmacologia , Testes de Sensibilidade Microbiana , Solo , Triazóis/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA