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Precise detection involving droplets based on functional surfaces is promising for the parallelization and miniaturization of platforms and is significant in epidemic investigation, analyte recognition, environmental simulation, combinatorial chemistry, etc. However, a challenging and considerable task is obtaining mutually independent droplet arrays without cross-contamination and simultaneously avoiding droplet evaporation-caused quick reagent loss, inaccuracy, and failure. Herein, a strategy to generate mutually independent and hardly-volatile capsular droplet arrays using innovative mosaic patterned surfaces is developed. The evaporation suppression of the capsular droplet arrays is 1712 times higher than the naked droplet. The high evaporation suppression of the capsular droplet arrays on the surfaces is attributed to synergistic blocking of the upper oil and bottom mosaic gasproof layer. The scale-up of the capsular droplet arrays, the flexibility in shape, size, component (including aqueous, colloidal, acid, and alkali solutions), liquid volume, and the high-precision hazardous substance testing proves the concept's high compatibility and practicability. The mutually independent capsular droplet arrays with amazingly high evaporation suppression are essential for the new generation of high-performance open-surface microfluidic chips used in COVID-19 diagnosis and investigation, primary screening, in vitro enzyme reactions, environmental monitoring, nanomaterial synthesis, etc.
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The extensive use of fossil fuels and global climate change have raised ever-increasing attention to sustainable development, global food security and the replacement of fossil fuels by renewable energy. Several C4 monocot grasses have excellent photosynthetic ability, stress tolerance and may rapidly produce biomass in marginal lands with low agronomic inputs, thus representing an important source of bioenergy. Among these grasses, Sorghum bicolor has been recognized as not only a promising bioenergy crop but also a research model due to its diploidy, simple genome, genetic diversity and clear orthologous relationship with other grass genomes, allowing sorghum research to be easily translated to other grasses. Although sorghum molecular genetic studies have lagged far behind those of major crops (e.g., rice and maize), recent advances have been made in a number of biomass-related traits to dissect the genetic loci and candidate genes, and to discover the functions of key genes. However, molecular and/or targeted breeding toward biomass-related traits in sorghum have not fully benefited from these pieces of genetic knowledge. Thus, to facilitate the breeding and bioenergy applications of sorghum, this perspective summarizes the bioenergy applications of different types of sorghum and outlines the genetic control of the biomass-related traits, ranging from flowering/maturity, plant height, internode morphological traits and metabolic compositions. In particular, we describe the dynamic changes of carbohydrate metabolism in sorghum internodes and highlight the molecular regulators involved in the different stages of internode carbohydrate metabolism, which affects the bioenergy utilization of sorghum biomass. We argue the way forward is to further enhance our understanding of the genetic mechanisms of these biomass-related traits with new technologies, which will lead to future directions toward tailored designing sorghum biomass traits suitable for different bioenergy applications.
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Sorghum , Sorghum/genética , Sorghum/metabolismo , Biomasa , Fitomejoramiento , Poaceae/genética , Poaceae/metabolismo , Grano Comestible , Combustibles FósilesRESUMEN
Kitchen-waste-derived biochar (KBC) was produced by thermal treatment at 400 °C, and a series of KBC/BiOX (X = Br, Cl) photocatalysts were developed using ultrasonication and solvothermal treatment. The as-prepared photocatalysts were characterized by several tests and investigated by photocatalytic reactions towards methyl orange (MO) and tetracycline (TC). The best photocatalysts, 0.15KBC/BiOBr and 0.15KBC/BiOCl separately achieved complete MO photodegradation in 20 min and 35 min. Further study confirmed that 0.15KBC/BiOBr and 0.15KBC/BiOCl possessed excellent photocatalytic efficiency that was 17.9 and 14.8 times higher than BiOBr and BiOCl, respectively. In addition, 0.15KBC/BiOX showed higher activity removal of TC than pure BiOX in 60 min. Notably, 0.15KBC/BiOX maintained a reproducible high photocatalytic efficiency after five recycles. Estimated band gap energy for 0.15KBC/BiOBr (2.40 eV) and 0.15KBC/BiOCl (3.00 eV) was considerably lower than that of BiOBr (2.73 eV) and BiOCl (3.30 eV), indicating a delocalized state was created when forming electronic pathways on the interface. Besides, visible-light harvesting of photocatalysts got promoted by the modification of KBC. Active species trapping experiments and electron paramagnetic resonance (EPR) tests illustrated that photogenerated holes were the principal active species, while âOH was involved in the reaction. The successful synthesis of 0.15KBC/BiOX catalyst provided a new approach on simultaneously degrading organic contaminants in water and disposing of excessive kitchen waste.
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Carbón Orgánico , Nanocompuestos , Catálisis , Fotólisis , TetraciclinaRESUMEN
The novel fourth-generation fluoroquinolones (FQs) were developed to improve the antimicrobial activity and their utilization has rapidly increased in recent years. However, knowledge of the ecotoxicity and microalgae-mediated biodegradation of these novel FQs is limited. In this research, the toxic effects of moxifloxacin (MOX) and gatifloxacin (GAT) on Chlamydomonas reinhardtii as well as their biodegradation and metabolic fate were investigated. The results showed that the toxicity of MOX to C. reinhardtii was higher than that of GAT, and increased with culture time. Chlorophyll fluorescence and pigment content analyses suggested that the decrease in photosynthetic efficiency was primarily caused by the inhibition of electron transport after QA in PSII complex. These FQs induced oxidative damage in cells, and the antioxidation mechanisms of C. reinhardtii were analyzed. The maximum MOX removal of 77.67% by C. reinhardtii was achieved at 1 mg/L MOX, whereas the maximum GAT removal of 34.04% was attained at 20 mg/L GAT. The different hydrophilicity and lipophilicity of these FQs resulted in distinct findings in biodegradation experiments. Identification of the transformation products suggested that the likely biodegradation pathways of FQs by C. reinhardtii were hydroxylation, demethylation, and ring cleavage.
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Chlamydomonas reinhardtii , Biodegradación Ambiental , Fluoroquinolonas/metabolismo , Fluoroquinolonas/toxicidad , Gatifloxacina/farmacología , Moxifloxacino/metabolismo , Moxifloxacino/farmacología , FotosíntesisRESUMEN
Seasonal influenza epidemics occur both in northern and southern hemispheres every year. Despite the differences in influenza virus surface antigens and virulence of seasonal subtypes, manufacturers are well-adapted to respond to this periodical vaccine demand. Due to decades of influenza virus research, the development of new influenza vaccines is relatively straight forward. In similarity with the ongoing coronavirus disease 2019 pandemic, vaccine manufacturing is a major bottleneck for a rapid supply of the billions of doses required worldwide. In particular, egg-based vaccine production would be difficult to schedule and shortages of other egg-based vaccines with high demands also have to be anticipated. Cell culture-based production systems enable the manufacturing of large amounts of vaccines within a short time frame and expand significantly our options to respond to pandemics and emerging viral diseases. In this study, we present an integrated process for the production of inactivated influenza A virus vaccines based on a Madin-Darby Canine Kidney (MDCK) suspension cell line cultivated in a chemically defined medium. Very high titers of 3.6 log10 (HAU/100 µl) were achieved using fast-growing MDCK cells at concentrations up to 9.5 × 106 cells/ml infected with influenza A/PR/8/34 H1N1 virus in 1 L stirred tank bioreactors. A combination of membrane-based steric-exclusion chromatography followed by pseudo-affinity chromatography with a sulfated cellulose membrane adsorber enabled full recovery for the virus capture step and up to 80% recovery for the virus polishing step. Purified virus particles showed a homogenous size distribution with a mean diameter of 80 nm. Based on a monovalent dose of 15 µg hemagglutinin (single-radial immunodiffusion assay), the level of total protein and host cell DNA was 58 µg and 10 ng, respectively. Furthermore, all process steps can be fully scaled up to industrial quantities for commercial manufacturing of either seasonal or pandemic influenza virus vaccines. Fast production of up to 300 vaccine doses per liter within 4-5 days makes this process competitive not only to other cell-based processes but to egg-based processes as well.
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COVID-19 , Técnicas de Cultivo de Célula , Subtipo H1N1 del Virus de la Influenza A/crecimiento & desarrollo , Vacunas contra la Influenza/metabolismo , SARS-CoV-2/crecimiento & desarrollo , Animales , Perros , Células de Riñón Canino Madin DarbyRESUMEN
Similar to the recent COVID-19 pandemic, influenza A virus poses a constant threat to the global community. For the treatment of flu disease, both antivirals and vaccines are available with vaccines the most effective and safest approach. In order to overcome limitations in egg-based vaccine manufacturing, cell culture-based processes have been established. While this production method avoids egg-associated risks in face of pandemics, process intensification using animal suspension cells in high cell density perfusion cultures should allow to further increase manufacturing capacities worldwide. In this work, we demonstrate the development of a perfusion process using Madin-Darby canine kidney (MDCK) suspension cells for influenza A (H1N1) virus production from scale-down shake flask cultivations to laboratory scale stirred tank bioreactors. Shake flask cultivations using semi-perfusion mode enabled high-yield virus harvests (4.25 log10(HAU/100 µL)) from MDCK cells grown up to 41 × 106 cells/mL. Scale-up to bioreactors with an alternating tangential flow (ATF) perfusion system required optimization of pH control and implementation of a temperature shift during the infection phase. Use of a capacitance probe for on-line perfusion control allowed to minimize medium consumption. This contributed to a better process control and a more economical performance while maintaining a maximum virus titer of 4.37 log10(HAU/100 µL) and an infectious virus titer of 1.83 × 1010 virions/mL. Overall, this study clearly demonstrates recent advances in cell culture-based perfusion processes for next-generation high-yield influenza vaccine manufacturing for pandemic preparedness. KEY POINTS: ⢠First MDCK suspension cell-based perfusion process for IAV produciton was established. ⢠"Cell density effect" was overcome and process was intensified by reduction of medium use and automated process control. ⢠The process achieved cell density over 40 × 106 cells/mL and virus yield over 4.37 log10(HAU/100 µL).
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Subtipo H1N1 del Virus de la Influenza A/fisiología , Cultivo de Virus/métodos , Replicación Viral/fisiología , Animales , Reactores Biológicos , Perros , Células de Riñón Canino Madin DarbyRESUMEN
In this study, different carbon quantum dots (CQDs)/NaBiO3 hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively. These hybrid materials exhibit an enhanced photocatalytic reduction of hexavalent chromium (Cr(VI)) in the aqueous medium. Zero-dimensional nanoparticles of CQDs were embedded within the two-dimensional NaBiO3 nanosheets by the hydrothermal process. Compared with that of the pure NaBiO3 nanosheets, the photocatalytic performance of the hybrid catalysts was significantly high and 6 wt.% CQDs/NaBiO3 catalyst exhibited better photocatalytic performance. We performed the first-principles density functional theory calculations to study the interfacial properties of pure NaBiO3 nanosheets and hybrid photocatalysts, and confirmed the CQDs played an important role in the CQDs/NaBiO3 composites. The experimental results indicated that the enhanced reduction of Cr(VI) was probably due to the high loading of CQDs (electron acceptor) on NaBiO3, which made NaBiO3 nanomaterials to respond in visible light and significantly improved their electron-hole separation efficiency.
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Puntos Cuánticos , Carbono , Cromo , LuzRESUMEN
Microplastics and nonylphenol (NP) are considered as emerging pollutant and have attracted wide attention, while their combined toxicity on aquatic organisms is barely researched. Therefore, the combined toxicity influence of NP with three types of microplastics containing polyethylene (PE1000, 13 µm and PE, 150 µm), polyamide (PA1000, 13 µm and PA, 150 µm) polystyrene (PS, 150 µm) on microalgae Chlorella pyrenoidosa was analyzed. Both growth inhibition, chlorophyll fluorescence, superoxide dismutase (SOD), malondialdehyde (MDA), and catalase (CAT) were determined. We found that single microplastics and NP both inhibited algal growth, thereby causing oxidative stress. The order of inhibition effect in single microplastics experiment was PE1000 > PA1000 > PE ≈ PS > PA. The combined toxicity experiment results indicated that the presence of microplastics had positive effect in terms of alleviating NP toxicity to C. pyrenoidosa, and the microplastics adsorption capacity to NP was the dominant contributing factor for this effect. According to the independent action model, the combined toxicity was antagonistic. Because the negative effect of smaller size microplastics on algal growth was aggravated with prolonged exposure time, the optimum effect of microplastics alleviated NP toxicity was PA1000 at 48 h, while this effect was substituted by PA at 96 h during combined toxicity. Thus, the toxicity of smaller size microplastics has a nonnegligible influence on combined toxicity. This study confirms that microplastics significantly affected the toxicity of organic pollutants on microalgae. Further research on the combined toxicity of smaller size microplastics with pollutants in chronic toxicity is needed.
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Chlorella/efectos de los fármacos , Microplásticos/toxicidad , Fenoles/toxicidad , Contaminantes Químicos del Agua/toxicidad , Adsorción , Catalasa/metabolismo , Chlorella/enzimología , Chlorella/metabolismo , Interacciones Farmacológicas , Malondialdehído/metabolismo , Microalgas/efectos de los fármacos , Microalgas/enzimología , Microalgas/metabolismo , Microplásticos/química , Estrés Oxidativo , Poliestirenos/toxicidad , Superóxido Dismutasa/metabolismo , Contaminantes Químicos del Agua/químicaRESUMEN
The present research examined the feasibility of cultivating Chlorella pyrenoidosa in pickle industry wastewater for simultaneous nutrient removal and lipid production. The characteristics of microalgae growth, nutrient removal, lipid accumulation and composition of C. pyrenoidosa cultivated in pickle wastewater with different dilution ratios were investigated. The results showed the maximum algae biomass concentration of 1.57 ± 0.12 g L-1 was achieved in non-diluted pickle wastewater with the highest biomass productivity of 170.65 mg L-1 day-1. Maximum nutrient removal efficiency was observed in 20.0% pickle wastewater with removal rates of chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN) and NH4-N at 84.67%, 92.46%, 85.82% and 93.42%, respectively. The lipid content of C. pyrenoidosa growing in pickle wastewater ranged from 29.73% to 31.78%, with a highest lipid productivity of 57.23 mg L-1 day-1. The relative content of triolefinic acids (C16:3 and C18:3) decreased while the monoenoic acids (C16:1 and C18:1) increased synchronously with the pickle wastewater concentration. Unsaturated fatty acid methyl esters were the main components, ranging from 73.04% to 77.6%. The biodiesel properties satisfied the major specifications in US and European biodiesel standards. The results indicated that C. pyrenoidosa is a promising species for nutrient removal together with lipid production in pickle industry wastewater.
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Chlorella , Microalgas , Eliminación de Residuos Líquidos/métodos , Biomasa , Lípidos , Nitrógeno , Nutrientes , Aguas ResidualesRESUMEN
A series of inâ situ formed alkenyl diboronate complexes from alkenyl Grignard reagents (commercially available or prepared from alkenyl bromides and Mg) with B2 Pin2 (bis(pinacolato)diboron) react with diverse alkyl halides by a Ru photocatalyst to give various gem-bis(boryl)alkanes. Alkyl radicals add efficiently to the alkenyl diboronate complexes, and the adduct radical anions undergo radical-polar crossover, specifically, a 1,2-boryl-anion shift from boron to the α-carbon sp2 center. This transformation shows good functional-group compatibility and can serve as a powerful synthetic tool for late-stage functionalization in complex compounds. Measurements of the quantum yield reveal that a radical-chain mechanism is operative in which the alkenyl diboronates acts as reductive quencher for the excited state of the photocatalyst.
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Objective.Emotion recognition based on electroencephalography (EEG) is garnering increasing attention among researchers due to its wide-ranging applications and the rise of portable devices. Deep learning-based models have demonstrated impressive progress in EEG-based emotion recognition, thanks to their exceptional feature extraction capabilities. However, the manual design of deep networks is time-consuming and labour-intensive. Moreover, the inherent variability of EEG signals necessitates extensive customization of models, exacerbating these challenges. Neural architecture search (NAS) methods can alleviate the need for excessive manual involvement by automatically discovering the optimal network structure for EEG-based emotion recognition.Approach.In this regard, we propose AutoEER (AutomaticEEG-basedEmotionRecognition), a framework that leverages tailored NAS to automatically discover the optimal network structure for EEG-based emotion recognition. We carefully design a customized search space specifically for EEG signals, incorporating operators that effectively capture both temporal and spatial properties of EEG. Additionally, we employ a novel parameterization strategy to derive the optimal network structure from the proposed search space.Main results.Extensive experimentation on emotion classification tasks using two benchmark datasets, DEAP and SEED, has demonstrated that AutoEER outperforms state-of-the-art manual deep and NAS models. Specifically, compared to the optimal model WangNAS on the accuracy (ACC) metric, AutoEER improves its average accuracy on all datasets by 0.93%. Similarly, compared to the optimal model LiNAS on the F1 Ssore (F1) metric, AutoEER improves its average F1 score on all datasets by 4.51%. Furthermore, the architectures generated by AutoEER exhibit superior transferability compared to alternative methods.Significance.AutoEER represents a novel approach to EEG analysis, utilizing a specialized search space to design models tailored to individual subjects. This approach significantly reduces the labour and time costs associated with manual model construction in EEG research, holding great promise for advancing the field and streamlining research practices.
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Emociones , Reconocimiento en Psicología , Humanos , Benchmarking , Electroencefalografía , Investigación EmpíricaRESUMEN
Environmental dissemination caused by widespread use of antibiotics has been regarded as a possible hazard to aquatic ecosystem and human health. The increasing misgivings make it imperative to develop a novel catalyst with remarkable visible-light-driven activity to remove antibiotics, especially for their simultaneous decontamination. Herein, C/BiOCl composites were successfully prepared by decorating BiOCl nanosheets on food wastes biochar (C) by a simple hydrolysis strategy. Not only the binary system of tetracycline antibiotics, but also the ternary mixture could be simultaneously photodegraded over 25% C/BiOCl within 15 min irradiation. The improved photocatalytic activities could be ascribed to the introduction of biochar, endowing increased surface area, enhanced separation of photo-generated charge carriers, and better light absorption. The as-prepared 25% C/BiOCl also demonstrated satisfactory stability and positive removal effect in actual water samples. The present work provides new insights into the development of biochar-based photocatalysts for simultaneous degradation of multiple antibiotics.
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Alimentos , Eliminación de Residuos , Humanos , Antibacterianos , Descontaminación , EcosistemaRESUMEN
Aims: We investigated the neuroprotective effects of Akkermansia muciniphila through the 'gut-brain' axis. Methods: Human colon cancer (Caco-2) cells treated with A. muciniphila metabolites were used to create the conditioned medium from Caco-2 cells treated with A. muciniphila metabolites (AC medium) medium, then treated human microglial clone 3 (HMC3) cells to simulate the gut-brain axis in vitro. Bioinformatics analyses were performed to investigate the molecular mechanisms by which the AC medium affected HMC3 cells. Results: The secretion of inflammatory cytokines IL-6 (0.37 ± 0.80-fold) and IL-17A (0.05 ± 0.18-fold) by HMC3 cells was inhibited by the AC medium. Differentially expressed genes were mainly enriched in immune-related signaling pathways, such as the cAMP and TGF-ß signaling pathways. Conclusion: A. muciniphila might be a source of therapeutic approaches to alleviate microglia-mediated neuroinflammatory diseases.
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Eje Cerebro-Intestino , Microglía , Humanos , Células CACO-2 , Verrucomicrobia , Células Clonales , EncéfaloRESUMEN
Biodegradable, biomass derived kombucha cellulose films with increased mechanical strength from 9.98 MPa to 18.18 MPa were prepared by vortex fluidic device (VFD) processing. VFD processing not only reduced the particle size of kombucha cellulose from approximate 2 µm to 1 µm, but also reshaped its structure from irregular to round. The increased mechanical strength of these polysaccharide-derived films is the result of intensive micromixing and high shear stress of a liquid thin film in a VFD. This arises from the incorporation at the micro-structural level of uniform, unidirectional strings of kombucha cellulose hydrolysates, which resulted from the topological fluid flow in the VFD. The biodegradability of the VFD generated polymer films was not compromised relative to traditionally generated films. Both films were biodegraded within 5 days.
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Alginatos , Celulosa , Agar/química , Celulosa/química , Biomasa , Fenómenos FísicosRESUMEN
Background: Alzheimer's disease (AD), an age-associated neurodegenerative disorder, currently lacks effective clinical therapeutics. Traditional Chinese Medicine (TCM) holds promising potential in AD treatment, exemplified by Danggui Shaoyao San (DSS), a TCM formulation. The precise therapeutic mechanisms of DSS in AD remain to be fully elucidated. This study aims to uncover the therapeutic efficacy and underlying mechanisms of DSS in AD, employing an integrative approach encompassing gut microbiota and metabolomic analyses. Methods: Thirty Sprague-Dawley (SD) rats were allocated into three groups: Blank Control (Con), AD Model (M), and Danggui Shaoyao San (DSS). AD models were established via bilateral intracerebroventricular injections of streptozotocin (STZ). DSS was orally administered at 24 g·kg-1·d-1 (weight of raw herbal materials) for 14 days. Cognitive functions were evaluated using the Morris Water Maze (MWM) test. Pathological alterations were assessed through hematoxylin and eosin (HE) staining. Bloodstream metabolites were characterized, gut microbiota profiled through 16S rDNA sequencing, and cortical metabolomics analyzed. Hippocampal proinflammatory cytokines (IL-1ß, IL-6, TNF-α) were quantified using RT-qPCR, and oxidative stress markers (SOD, CAT, GSH-PX, MDA) in brain tissues were measured with biochemical assays. Results: DSS identified a total of 1,625 bloodstream metabolites, predominantly Benzene derivatives, Carboxylic acids, and Fatty Acyls. DSS significantly improved learning and spatial memory in AD rats and ameliorated cerebral tissue pathology. The formulation enriched the probiotic Ligilactobacillus, modulating metabolites like Ophthalmic acid (OA), Phosphocreatine (PCr), Azacridone A, Inosine, and NAD. DSS regulated Purine and Nicotinate-nicotinamide metabolism, restoring balance in the Candidatus Saccharibacteria-OA interplay and stabilizing gut microbiota-metabolite homeostasis. Additionally, DSS reduced hippocampal IL-1ß, IL-6, TNF-α expression, attenuating the inflammatory state. It elevated antioxidative enzymes (SOD, CAT, GSH-PX) while reducing MDA levels, indicating diminished oxidative stress in AD rat brains. Conclusion: DSS addresses AD pathology through multifaceted mechanisms, encompassing gut microbiome regulation, specific metabolite modulation, and the mitigation of inflammation and oxidative stress within the brain. This holistic intervention through the Microbial-Gut-Brain Axis (MGBA) underscores DSS's potential as an integrative therapeutic agent in combatting AD.
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In order to extract the outlines of macular edema from OCT images of macular, and estimate the volume of edema, we have to accurately segment the macular edema region. In this paper, an improved PCNN algorithm was proposed to conduct the above process. Combined with the adaptive base threshold, and the simplified neural network parameters, a binary image of macular edema was produced. According to the principle of maximum image entropy, the optimal number of iterations was determined as 8, which was evaluated by its misclassification rate. Simulation showed that the proposed algorithm could extract the macular edema region rapidly and accurately, providing the basis for further OCT image analysis.
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Algoritmos , Angiografía con Fluoresceína/métodos , Edema Macular/diagnóstico por imagen , Tomografía de Coherencia Óptica/métodos , Humanos , RadiografíaRESUMEN
The CuCr mixed oxides catalysts supported on ZSM-5 zeolite (CuCr/ZSM-5) were synthesized via metal organic chemical vapour deposition (MOCVD) method for catalytic oxidation of trichloroethylene (TCE). SEM, XRD, BET, H2-TPR, NH3-TPD and XPS were tested. The active components were dispersed uniformly over the surface of ZSM-5 zeolite. The catalytic experimental results exhibited that the CuCr/ZSM-5 exhibited the best catalytic performance for TCE oxidation with 90% of TCE at 338°C and the concentration of C2Cl4 decreased compared with Cu/ZSM-5 and Cr/ZSM-5. The possible reason is that CuCr/ZSM-5 has superior reducibility, higher Cu2+ surface concentration as well as more surface oxygen.
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Analyzing the supply and demand of ecosystem services and the regional balance pattern is an important basis for improving the ecological management level. Taking the Yangtze River economic belt as the study area, the spatiotemporal characteristics and balance pattern of ecosystem service supply and demand are quantitatively revealed based on equivalent factors, supply and demand balance modeling and quantile regression. The results show that: (1) the ecosystem services value in the research area experienced a change process of "increase-decrease-increase" from 2000 to 2020. The ecological service value of cultivated land and grassland presented a continuous decline, with decreases of 20.446 billion and 4.53 billion yuan, respectively, in the past 20 years, with reduction rates of -4.82% and -3.98%, respectively. (2) The demand for ecosystem services showed an unbalanced and phased growth trend. The total demand for ecosystem services showed heterogeneity and agglomeration effects in space. High demand and higher demand areas are mainly distributed in the regions with relatively developed population and economy, including Yangtze River Delta urban agglomeration, "Changsha-Zhuzhou-Xiangtan" urban agglomeration, Poyang Lake Plain, Jianghan Plain and Chengdu Plain. (3) The overall pattern of the supply-demand balance of ecosystem services has changed little; however, there have also been significant changes in certain areas in individual years.
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Ecosistema , Ríos , China , Conservación de los Recursos Naturales , LagosRESUMEN
The narrow light-response range and high electron/hole recombination rate greatly restrict the widespread use of photocatalytic technology. The integration of exposing dominant facet of semiconductor and Z-scheme heterostructures designing is expected to break those barriers. Hereinï¼In this work, hydrothermal and ultrasonic stirring methods were used to selectively exposed the (001) and (110) facet of BiOI to construct the BiOI/CdS heterostructures. The obtained BiOI(001)/CdS material shown the maximum degradation for tetracycline-based antibiotics (Oxytetracycline, Tetracycline and Doxycycline), and excellent reduction of hexavalent chromium. Combining the electron spin resonance and scavenger experiments, the superior photocatalytic capacity was attributed to the generation of superoxide and hydroxyl radicals. DFT calculation results shown BiOI(001)/CdS performed high binding energy and adsorption energy for hexavalent chromium, and the different work function between BiOI(001) and CdS confirmed the building of internal electric field, thereby increased the charge separation. Finally, the Gaussian 09 and HPLC-MS program investigated the attack sites of free radicals and degradation pathways in the degradation of antibiotics. This study not only provides a potential photocatalyst, also gives an in-depth understanding of the photocatalytic properties of heterojunctions constructed by different exposed crystal facets.
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Bismuto , Cromo , Antibacterianos , Bismuto/química , Catálisis , Cromo/química , Tetraciclina/químicaRESUMEN
Biochar (C) applied in synthesizing photocatalysts to eliminate water pollution has been intensively investigated. Herein we report the first use of biochar pyrolyzed from food wastes at 400 °C (400C) and 700 °C to construct C/BiOBr composites via a facile hydrolysis approach. Photocatalytic performances could be significantly improved by choosing the appropriate carbonization temperature and adjusting the content of C in C/BiOBr composites. The prepared 1%400C/BiOBr exhibited the best photodegradation capacity towards methylene orange (20 mg/L) and tetracycline (50 mg/L). A series of characterization results illustrated that smooth structure and surface properties (oxygen functional groups and persistent free radicals) of 400C played an important role in enhancing the photocatalytic activities. Mechanism exploration suggested that h+ and ËO2- were the main active species thus contributing to photodegradation. This study provided a new insight into utilization of biochar derived from food wastes in photocatalysis and environmental remediation.