Comparison between two reactors using Trametes versicolor for agricultural wastewater treatment under non-sterile condition in sequencing batch mode

Altres ajuts: Acord transformatiu CRUE-CSICAgricultural wastewater is a major source of herbicides, which pose environmental and health concerns owing to their substantial use and poor elimination rate in conventional wastewater treatment plants. White-rot fungi are versatile in degrading xenobiotics; however, the key problem encountered with their application in actual scenarios is competition with indigenous microorganisms, mainly bacteria. To address this barrier, two different strategies were implemented in the present study. One strategy was to set up a trickle bed with Trametes versicolor immobilized on pine wood, and another strategy was to employ a T. versicolor-pelleted, fluidized-bed reactor to remove diuron and bentazon from actual wastewater under non-sterile conditions. The residence time in the trickle bed was estimated using three methodologies. With 10 batches of a 3-day cycle operation, although the trickle-bed reactor possessed a shorter contact time (8.5 h per cycle) and lower laccase activity compared with those of the fluidized-bed reactor, it demonstrated a higher removal yield and lower bacterial counts. In addition, the utilization of pine wood as a carrier obviously reduced the cost since no additional nutrients were required. Hence, after evaluating all advantages and limitations of both bioreactors, for the purpose of treating over the long term and scaling up, a trickle-bed reactor is the preferred choice

Two-orbital spin-fermion model study of ferromagnetism in honeycomb lattice

The spin-fermion model was previously successful to describe the complex phase diagrams of colossal magnetoresistive manganites and iron-based superconductors. In recent years, two-dimensional magnets have rapidly raised up as a new attractive branch of quantum materials, which are theoretically described based on classical spin models in most studies. Alternatively, here the two-orbital spin-fermion model is established as a uniform scenario to describe the ferromagnetism in a two-dimensional honeycomb lattice. This model connects the magnetic interactions with the electronic structures. Then the continuous tuning of magnetism in these honeycomb lattices can be predicted, based on a general phase diagram. The electron/hole doping, from the empty $e_{g}$ to half-filled $e_{g}$ limit, is studied as a benchmark. Our Monte Carlo result finds that the ferromagnetic $T_{C}$ reaches the maximum at the quarter-filled case. In other regions, the linear relationship between $T_{C}$ and doping concentration provides a theoretical guideline for the experimental modulations of two-dimensional ferromagnetism tuned by ionic liquid or electrical gating

Unlearnable Examples for Diffusion Models: Protect Data from Unauthorized Exploitation

Diffusion models have demonstrated remarkable performance in image generation tasks, paving the way for powerful AIGC applications. However, these widely-used generative models can also raise security and privacy concerns, such as copyright infringement, and sensitive data leakage. To tackle these issues, we propose a method, Unlearnable Diffusion Perturbation, to safeguard images from unauthorized exploitation. Our approach involves designing an algorithm to generate sample-wise perturbation noise for each image to be protected. This imperceptible protective noise makes the data almost unlearnable for diffusion models, i.e., diffusion models trained or fine-tuned on the protected data cannot generate high-quality and diverse images related to the protected training data. Theoretically, we frame this as a max-min optimization problem and introduce EUDP, a noise scheduler-based method to enhance the effectiveness of the protective noise. We evaluate our methods on both Denoising Diffusion Probabilistic Model and Latent Diffusion Models, demonstrating that training diffusion models on the protected data lead to a significant reduction in the quality of the generated images. Especially, the experimental results on Stable Diffusion demonstrate that our method effectively safeguards images from being used to train Diffusion Models in various tasks, such as training specific objects and styles. This achievement holds significant importance in real-world scenarios, as it contributes to the protection of privacy and copyright against AI-generated content

Flew Over Learning Trap: Learn Unlearnable Samples by Progressive Staged Training

Unlearning techniques are proposed to prevent third parties from exploiting unauthorized data, which generate unlearnable samples by adding imperceptible perturbations to data for public publishing. These unlearnable samples effectively misguide model training to learn perturbation features but ignore image semantic features. We make the in-depth analysis and observe that models can learn both image features and perturbation features of unlearnable samples at an early stage, but rapidly go to the overfitting stage since the shallow layers tend to overfit on perturbation features and make models fall into overfitting quickly. Based on the observations, we propose Progressive Staged Training to effectively prevent models from overfitting in learning perturbation features. We evaluated our method on multiple model architectures over diverse datasets, e.g., CIFAR-10, CIFAR-100, and ImageNet-mini. Our method circumvents the unlearnability of all state-of-the-art methods in the literature and provides a reliable baseline for further evaluation of unlearnable techniques

Synthetic transactivation screening reveals ETV4 as broad coactivator of hypoxia-inducible factor signaling

The human prolyl-4-hydroxylase domain (PHD) proteins 1–3 are known as cellular oxygen sensors, acting via the degradation of hypoxia-inducible factor (HIF) α-subunits. PHD2 and PHD3 genes are inducible by HIFs themselves, suggesting a negative feedback loop that involves PHD abundance. To identify novel regulators of the PHD2 gene, an expression array of 704 transcription factors was screened by a method that allows distinguishing between HIF-dependent and HIF-independent promoter regulation. Among others, the E-twenty six transcription factor ETS translocation variant 4 (ETV4) was found to contribute to PHD2 gene expression particularly under hypoxic conditions. Mechanistically, complex formation between ETV4 and HIF-1/2α was observed by mammalian two-hybrid and fluorescence resonance energy transfer analysis. HIF-1α domain mapping, CITED2 overexpression and factor inhibiting HIF depletion experiments provided evidence for cooperation between HIF-1α and p300/CBP in ETV4 binding. Chromatin immunoprecipitation confirmed ETV4 and HIF-1α corecruitment to the PHD2 promoter. Of 608 hypoxically induced transcripts found by genome-wide expression profiling, 7.7% required ETV4 for efficient hypoxic induction, suggesting a broad role of ETV4 in hypoxic gene regulation. Endogenous ETV4 highly correlated with PHD2, HIF-1/2α and several established markers of tissue hypoxia in 282 human breast cancer tissue samples, corroborating a functional interplay between the ETV4 and HIF pathways

Tumour–stroma interactions in colorectal cancer: converging on β-catenin activation and cancer stemness

Sporadic cases of colorectal cancer are primarily initiated by gene mutations in members of the canonical Wnt pathway, ultimately resulting in β-catenin stabilisation. Nevertheless, cells displaying nuclear β-catenin accumulation are nonrandomly distributed throughout the tumour mass and preferentially localise along the invasive front where parenchymal cells are in direct contact with the stromal microenvironment. Here, we discuss the putative role played by stromal cell types in regulating β-catenin intracellular accumulation in a paracrine fashion. As such, the tumour microenvironment is likely to maintain the cancer stem cell phenotype in a subset of cells, thus mediating invasion and metastasis

Dietary phytochemicals, HDAC inhibition, and DNA damage/repair defects in cancer cells

Genomic instability is a common feature of cancer etiology. This provides an avenue for therapeutic intervention, since cancer cells are more susceptible than normal cells to DNA damaging agents. However, there is growing evidence that the epigenetic mechanisms that impact DNA methylation and histone status also contribute to genomic instability. The DNA damage response, for example, is modulated by the acetylation status of histone and non-histone proteins, and by the opposing activities of histone acetyltransferase and histone deacetylase (HDAC) enzymes. Many HDACs overexpressed in cancer cells have been implicated in protecting such cells from genotoxic insults. Thus, HDAC inhibitors, in addition to unsilencing tumor suppressor genes, also can silence DNA repair pathways, inactivate non-histone proteins that are required for DNA stability, and induce reactive oxygen species and DNA double-strand breaks. This review summarizes how dietary phytochemicals that affect the epigenome also can trigger DNA damage and repair mechanisms. Where such data is available, examples are cited from studies in vitro and in vivo of polyphenols, organosulfur/organoselenium compounds, indoles, sesquiterpene lactones, and miscellaneous agents such as anacardic acid. Finally, by virtue of their genetic and epigenetic mechanisms, cancer chemopreventive agents are being redefined as chemo- or radio-sensitizers. A sustained DNA damage response coupled with insufficient repair may be a pivotal mechanism for apoptosis induction in cancer cells exposed to dietary phytochemicals. Future research, including appropriate clinical investigation, should clarify these emerging concepts in the context of both genetic and epigenetic mechanisms dysregulated in cancer, and the pros and cons of specific dietary intervention strategies

Developing and scaling up a trickle bed reactor for degrading pesticides from agricultural wastewater by fungi

Al llarg de les darreres dècades, la contaminació del medi aquàtic per part de nombrosos micro-contaminants és un dels problemes globals a què s'enfronta la humanitat. Tot i que aquests compostos es detecten a baixes concentracions, susciten considerables preocupacions toxicològiques i representen una greu amenaça pels ecosistemes i els éssers humans. Entre els micro-contaminants, els pesticides, introduïts involuntàriament o deliberadament en el medi ambient com a resultat d'activitats antròpiques, principalment pràctiques agrícoles, es consideren la contribució clau del deteriorament de l'aigua i un desafiament important per a les societats modernes, degut a la seva escassa eliminació en les plantes convencionals de tractament d'aigües residuals. Per tant, es necessita amb urgència el desenvolupament de tecnologies capaces d'eliminar-los de l'aigua. La gran varietat i les característiques de baixa especificitat vers els substrats del sistema enzimàtic degradador de la lignina, permeten als fongs de podridura blanca (WRF) ser una opció per afrontar aquesta creixent preocupació mundial. La present tesi té com a objectiu desenvolupar una planta pilot que permeti abordar l'eliminació de pesticides de les aigües residuals agrícoles mitjançant un tractament per WRF en condicions no estèrils operant duran períodes llargs de temps sense necessitat de canviar el biocatalitzador. En primer lloc, es va seleccionar un candidat òptim entre diversos fongs ligninolítics estudiant la degradació de diferents pesticides, que es van detectar amb freqüència en dues zones agrícoles catalanes. Trametes versicolor es va seleccionar per a ser utilitzat en els reactors a causa del seu millor rendiment de degradació. A més, es van investigar les característiques de degradació dels pesticides seleccionats, inclosos el sistema enzimàtic involucrat i la via de degradació. En segon lloc, es va construir un filtre percolador a escala de laboratori (TBR) amb T. versicolor immobilitzat sobre estelles de fusta de pi. Es va utilitzar per tractar l'aigua agrícola (AW) dopada amb pesticides seleccionats i es va comparar amb el reactor de llit fluïditzat (FBR), ben establert en el grup de recerca, es van analitzar diferents aspectes, com ara l'eficàcia de l'eliminació, la robustesa i el cost econòmic, etc. TBR va resultar la millor opció. Després, es va aplicar per eliminar els pesticides de l'AW real, i es van obtenir bons resultats. Tant amb l'aigua real com amb la dopada es va demostrar que el suport lignocel·lulòsic no només actua com a font de nutrients, sinó que també té un paper vital en el tractament, degut a l'adsorció. A més, els resultats suggereixen que es podria aconseguir una millora en el procés amb més biomassa a l'interior del reactor, per la qual cosa es va canviar de suport, escollint un de l'habitat natural del fong. Basant-se en els resultats previs, es va construir un TBR a escala pilot amb T. versicolor colonitzat sobre estelles de fusta de roure i va funcionar amb èxit durant 186 dies tractant AW dopada en condicions no estèrils i en continu. Al llarg del període de funcionament, el reactor es va comportar estable i prometedor. El problema de l'obstrucció, com a conseqüència d'un creixement continu del fong, es va abordar eficaçment mitjançant la reordenació del llit empacat, sense danyar el biofilm. L'escalat del reactor va mostrar una bio-activitat persistent i una alta robustesa. En resum, aquest estudi aporta llum a la bioremediació d'aigües contaminades per pesticides mitjançant WRF. A més, serveix com a prova del concepte que els micro-contaminants de les aigües residuals poden ser eliminats mitjançant un tractament a llarg termini amb fongs amb podridura blanca.Durante las últimas décadas, la contaminación del medio acuático por numerosos microcontaminantes es uno de los problemas globales a los que se enfrenta la humanidad. Aunque esos compuestos normalmente se detectan en bajas concentraciones, suscitan considerables preocupaciones toxicológicas, lo que representa una grave amenaza para el ecosistema y los seres humanos. Entre los microcontaminantes, los pesticidas, introducidos de forma involuntaria o deliberada en el medio ambiente como resultado de actividades antropogénicas, principalmente prácticas agrícolas, se consideran la contribución clave en el deterioro del agua y un importante desafío para las sociedades modernas, debido a su escasa eliminación en las plantas de tratamiento de aguas residuales convencionales. Por lo tanto, se necesita con urgencia el desarrollo de tecnologías capaces de eliminarlos del agua. La gran variedad y la característica de baja especificidad por el sustrato del sistema de enzimas que degradan la lignina otorgan un alto potencial a los hongos de pudrición blanca (WRF) para abordar esta creciente preocupación mundial. La presente tesis tiene como objetivo desarrollar una planta piloto que permita eliminar pesticidas de aguas residuales agrícolas con un tratamiento WRF en condiciones no estériles y durante largos periodos sin necesidad de cambiar el biocatalizador. En primer lugar, se seleccionó un candidato óptimo entre varios hongos ligninolíticos utilizando como sustratos diferentes pesticidas, que se detectaban con frecuencia en dos zonas agrícolas catalanas. Se seleccionó Trametes versicolor para ser utilizado en los reactores debido a su mayor rendimiento de degradación. Además, se investigaron las características de degradación de los pesticidas seleccionados por T. versicolor, incluido el sistema enzimático y la vía de degradación. En segundo lugar, se construyó un filtro percolador (TBR) a escala de laboratorio con T. versicolor inmovilizado sobre astillas de madera de pino. Se empleó para tratar agua de agricultura (AW) dopada con pesticidas seleccionados, y se comparó con el reactor de lecho fluidizado (FBR) bien establecido en el grupo de investigación, en función de diferentes aspectos, como la eficacia de eliminación, la robustez y el costo económico, etc. En consecuencia, TBR resultó la mejor opción en el estudio comparativo. Posteriormente se aplicó para eliminar pesticidas de AW reales y se obtuvieron buenos resultados. Tanto los experimentos con aguas reales AW, como con AW dopadas indican que el soporte lignocelulósico no solo actúa como fuente de nutrientes, sino que también desempeña un papel vital en el tratamiento, a través de la adsorción. Además, los resultados demuestran que se podría mejorar el proceso aumentando la cantidad de biomasa en el reactor, por lo que se cambio de soporte, eligiendo uno del hábitat natural de hongo. Sobre la base los resultados previos, se construyó un TBR a escala piloto con astillas de madera de roble colonizadas por T. versicolor y se operó con éxito durante 186 días para tratar el AW dopada, en condiciones no estériles y operando en continuo. Durante el período de tratamiento, se alcanzaron resultados estables y prometedores. El problema de la obstrucción, como consecuencia del crecimiento continuo del hongo, se abordó eficazmente mediante la reorganización del lecho empacado, sin dañar la biopelícula. El reactor ampliado mostró una bioactividad persistente y una gran robustez. En resumen, este estudio arroja luz sobre la biorremediación de agua contaminada con pesticidas mediante WRF. Además, sirve como prueba de concepto de que los microcontaminantes de las aguas residuales pueden eliminarse mediante un tratamiento prolongado con hongos de podredumbre blanca sin necesidad de adicionar nutrientes ni renovar la biomasa.Over the last decades, the pollution of aquatic environment by numerous micropollutants is one of global problems facing humanity. Although those compounds are normally present at low concentrations, they raise considerable toxicological concerns, posing severe threat to ecosystem and human beings. Among micropollutants, pesticides, introduced inadvertently or deliberately into environment resulted from anthropogenic activities, mainly agricultural practice, are widely accepted as the key trigger of water deterioration and a major current challenge for modern societies, since their poor elimination in conventional wastewater treatment plant. Thus, the development of technologies capable of reducing them from water body is urgently needed. The richness and low-substrate specificity features of lignin-degrading enzyme system enable the high potential of white-rot fungi (WRF) in addressing this escalating world concern. The present thesis aims to develop a pilot plant that is allowed to address pesticides from agricultural wastewater in a long-term treatment by WRF under non-sterile conditions. Firstly, an optimal candidate was screened out from several ligninolytic fungi using different pesticides, which were frequently detected in two Catalonian agricultural area, as substrates. Trametes versicolor was selected for reactors set up owing to its remarked performance. In addition, the degradation characteristics of the targeted pesticides by the chosen alternative were investigated, including enzymatic system and degradation pathway. Secondly, a lab-scale trickle bed (TBR) was constructed with T. versicolor immobilized on pine wood chips. It was employed to treat agriculture water (AW) fortified by selected pesticides, and compared to the well established fluidized bed reactor (FBR) based on different aspects, such as removal efficacy, robustness, and economic cost, etc. Accordingly, TBR emerged as the preferred option in the comparative study. Then, it was subsequently applied for eliminating pesticides from real AW, turned out good results were obtained. Both spiked and real scenarios indicate that the lignocellulosic carrier not only act as nutrient source, but also played a vital role in treatment, through adsorption effect. Besides, our findings suggest that an enhanced demonstration could be achieved by retaining the biomass inside the reactor. Based on gained experiences and perspectives, a pilot-scale TBR with T. versicolor colonized on oak wood chips, was installed and successfully operated for 186 days to deal with spiked AW under non-sterile conditions in continuous mode. Throughout the long-term running period, stable and promising performances were approached. The clogging issue, as a consequence of continuous fungal growth, was effectively tackled by rearrangement of the packing bed, without damaging the biofilm. The scaled-up reactor displayed persistent bioactivity and high robustness. To sum up, this study sheds light into pesticides-contaminated water bioremediation by WRF. Also, it serves as a proof of the concept that micropollutants in the wastewater can be dismissed by a long-term white-rot fungal treatment

Oak wood provides suitable nutrients for long-term continuous pesticides removal by Trametes versicolor in a pilot plant trickle bed reactor

In the Catalan area (Spain), diuron and bentazon are extensively used to control weeds and are therefore abundant in agricultural drainage. White-rot fungi have a high potential for removing these contaminants because of a potent and nonsubstrate-specific lignin-degrading enzyme system. Unfortunately, bacterial contamination hinders practical application of fungal treatment. In this study, a trickle bed reactor (TBR) containing Trametes versicolor immobilized on oak wood was used to treat spiked nonsterile agricultural wastewater. The TBR was operated for 186 days in continuous mode at different recirculation rates. The TBR exhibited stable and promising performance, with an average removal of diuron and bentazon of up to 80% and 67%, respectively, at steady state. The lignocellulosic carrier was the only carbon resource used for the immobilized biomass throughout the entire operation period and effectively suppressed bacterial growth. Adsorption of the contaminants on oak wood was also an important contribution to pesticide removal. The constructed system exhibited persistent fungal activity and high robustness to adverse impacts regarding clogging, based on pesticides removal, laccase activity, ergosterol quantity and scanning electron microscopy analysis. This study demonstrates the concept of long-term fungal treatment and paves the way to full-scale application.This work has been supported by the Spanish Ministry of Economy and Competitiveness State Research Agency (CTM2016-75587-C2-1-R) and co-financed by the European Union through the European Regional Development Fund (ERDF). This work was partly supported by the Generalitat de Catalunya (Consolidate Research Group 2017-SGR-0014). K. Hu acknowledges the financial support from China Scholarship Council (CSC No. 201706910092).Peer reviewe

Plant volatiles as regulators of plant defense and herbivore immunity: molecular mechanisms and unanswered questions

Plants release distinct blends of herbivore-induced plant volatiles (HIPVs) upon herbivore attack. HIPVs have long been known to influence the behavior of herbivores and natural enemies. In addition, HIPVs can act as physiological regulators that induce or prime plant defenses. Recent work indicates that the regulatory capacity of HIPVs may extend to herbivore immunity: herbivores that are exposed to HIPVs can become more resistant or susceptible to parasitoids and pathogens. While the mechanisms of HIPV-mediated plant defense regulation are being unraveled, the mechanisms underlying the regulation of herbivore immunity are unclear. Evidence so far suggests a high degree of context dependency. Here, we review the mechanisms by which HIPVs regulate plant defense and herbivore immunity. We address major gaps of knowledge and discuss directions for future mechanistic research to facilitate efforts to use the regulatory capacity of HIPVs for the biological control of insect pests