RESUMO
We theoretically address the coupling between trimer lattices and reveal the existence of stable multiple edge and interface states. It is shown the superlattice can provides a tunable number of topologically protected edge and interface states depending on the coupling strength and topological phase of the connecting lattices. Dynamics and transport properties of interface states are also investigated, Due to the interference of linear modes with different propagation constants, stable oscillations resulted from the coupling of interface states in finite trimerized waveguide arrays are observed and can give rise to optical coupling functionalities, including directional coupling, beam splitting and beam oscillator.
RESUMO
Topological quasiparticles have garnered significant research attention in condensed matter physics. However, they are exceedingly rare in two-dimensional systems, particularly those hosting unconventional topological quasiparticles. In this work, employing first-principles calculations and symmetry analysis, we demonstrate that PtS, PtSe, and PtTe monolayers serve as high-quality two-dimensional topological semimetal materials. These materials exhibit multiple types of topological quasiparticles around the Fermi level in the absence of spin-orbit coupling, such as conventional linear Weyl points and unconventional quadratic Weyl points in the PtS monolayer, as well as nodal loops in PtSe and PtTe monolayers. When spin-orbit coupling (SOC) is introduced, a tiny gap opens, transforming the systems into quantum spin hall insulators. Simultaneously, three spin-orbit Dirac points, robust against SOC, appear at the X, Y, and M points. We illustrate the symmetry protection, low-energy effective model, and edge states of these topological states. Our work provides an excellent material platform for studying novel two-dimensional topological quasiparticles and topological insulators.
RESUMO
Stapled antimicrobial peptides are an emerging class of artificial cyclic peptide molecules which have antimicrobial activity and potent structure stability. We previously published the Data Repository of Antimicrobial Peptides (DRAMP) as a manually annotated and open-access database of antimicrobial peptides (AMPs). In the update of version 3.0, special emphasis was placed on the new development of stapled AMPs, and a subclass of specific AMPs was added to store information on these special chemically modified AMPs. To help design low toxicity AMPs, we also added the cytotoxicity property of AMPs, as well as the expansion of newly discovered AMP data. At present, DRAMP has been expanded and contains 22259 entries (2360 newly added), consisting of 5891 general entries, 16110 patent entries, 77 clinical entries and 181 stapled AMPs. A total of 263 entries have predicted structures, and more than 300 general entries have links to experimentally determined structures in the Protein Data Bank. The update also covers new annotations, statistics, categories, functions and download links. DRAMP is available online at http://dramp.cpu-bioinfor.org/.
Assuntos
Anti-Infecciosos/química , Peptídeos Antimicrobianos/química , Fatores Imunológicos/química , Peptídeos Cíclicos/química , Software , Sequência de Aminoácidos , Aminoácidos , Animais , Anti-Infecciosos/classificação , Anti-Infecciosos/farmacologia , Peptídeos Antimicrobianos/classificação , Peptídeos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Materiais Biomiméticos , Bases de Dados de Proteínas , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Humanos , Fatores Imunológicos/classificação , Fatores Imunológicos/farmacologia , Internet , Camundongos , Anotação de Sequência Molecular , Peptídeos Cíclicos/classificação , Peptídeos Cíclicos/farmacologia , Estabilidade Proteica , Células RAW 264.7 , Relação Estrutura-AtividadeRESUMO
Sewage in wastewater treatment plants (WWTPs) can produce fugitive bioaerosols that pose a health risk to employees and residents. This study aimed to fugitive bioaerosols from two WWTPs with anaerobic-anoxic-oxic (AAO) processes, and bioaerosols control measures were proposed based on the results of these studies. It was found that the bioaerosols were mainly composed of microorganisms from dominant genera such as Romboutsia, Rubellimicrobium, Sphingomonas, Acidea, Cryptotrichosporon and water-soluble ions dominated by SO42-. Moreover, total suspended particulate (TSP), relative humidity (RH), wind speed (WS), Ca2+, NH4+, Na+, Cl-, NO3-, and K+ had positive effects on most dominant genera, while temperature (T) and SO42- had negative effects on most dominant genera. The source analysis showed that the bioaerosols in the indoor treatment facility's fine screen room and sludge dewatering plant mainly originated from sewage or sludge, and those in the aeration tank of the outdoor treatment facility mainly originated from the background air of WWTPs . By combining the characteristics of bioaerosols and the results of source analysis, targeted control measures were proposed from three aspects: source reduction of bioaerosol fugitives, control of bioaerosol propagation, and collection and treatment systems. This study provides the theoretical basis and ideas for controlling bioaerosols in WWTPs with AAO processes.
Assuntos
Esgotos , Purificação da Água , Humanos , Águas Residuárias , Anaerobiose , AerossóisRESUMO
Odor pollution has become a global environmental issue of increasing concern in recent years. Odor measurements are the basis of assessing and solving odor problems. Olfactory and chemical analysis can be used for odor and odorant measurements. Olfactory analysis reflects the subjective perception of human, and chemical analysis reveals the chemical composition of odors. As an alternative to olfactory analysis, odor prediction methods have been developed based on chemical and olfactory analysis results. The combination of olfactory and chemical analysis is the best way to control odor pollution, evaluate the performances of the technologies, and predict odor. However, there are still some limitations and obstacles for each method, their combination, and the prediction. Here, we present an overview of odor measurement and prediction. Different olfactory analysis methods (namely, the dynamic olfactometry method and the triangle odor bag method) are compared in detail, the latest revisions of the standard olfactometry methods are summarized, and the uncertainties of olfactory measurement results (i.e., the odor thresholds) are analyzed. The researches, applications, and limitations of chemical analysis and odor prediction are introduced and discussed. Finally, the development and application of odor databases and algorithms for optimizing odor measurement and prediction methods are prospected, and a preliminary framework for an odor database is proposed. This review is expected to provide insights into odor measurement and prediction.
Assuntos
Odorantes , Olfato , Humanos , Odorantes/análise , Olfatometria , Poluição Ambiental , AlgoritmosRESUMO
The present work investigated fundamental mediating mechanisms (i.e., flow experience, organizational identification, and trust), underlining the impact of authentic leadership on employee resilience during the turbulent COVID-19 pandemic. A total of 901 frontline employees working in a construction engineering company in China participated in this study. They were asked to respond to a battery of questionnaires comprising Trust Scale (affective-based, cognitive-based, and competence-based), Flow Proneness Questionnaire (FPQ), Organizational Identification Scale, Authentic Leadership Questionnaire, and Employee Resilience Scale. Results of structural equation modeling indicated that: (1) Authentic leadership positively predicted employee resilience in the COVID-19 pandemic, directly and indirectly. (2) As for the indirect relationship, two parallel mediation effects and one chain mediation were detected: employees' flow at work and organizational identification respectively and dependently mediated the relationship between authentic leadership and employee resilience; trust and organizational identification played as a chain mediation role within authentic leadership-employee resilience association. The study provides empirical evidence for organizations' resilience-building and leadership training programs. Findings also contribute to the literature by facilitating flow intervention, promoting organizational identification and trust to enhance the effect of authentic leadership in promoting positive psychological functioning of employee resilience. Limitations with respect to future research directions were also outlined.
RESUMO
The precise and controllable programming of the trans-cleavage activity of the CRISPR-Cas13a systems is significant but challenging for fabricating high-performance biosensing systems toward various kinds of biomolecule targets. In this work, we have demonstrated that under a critical low Mg2+ concentration, a simple and short single-stranded DNA (ssDNA) probe free of any modification can efficiently prevent the assembly of crRNA and LwaCas13a only by partially binding with the crRNA repeat region, thereby blocking the trans-cleavage activity of the LwaCas13a system. Furthermore, we have demonstrated that the blocked trans-cleavage activity of the LwaCas13a system can be recovered by various kinds of biologically important substances as long as they could specifically release the blocker DNA from the crRNA in a target-responsive manner, providing a facile route for the quantification of diverse biomarkers such as enzymes, antigens/proteins, and exosomes. To the best of our knowledge, this is reported for the first time that a simple ssDNA can be employed as the switch element to control the crRNA structure and regulate the trans-cleavage activity of Cas13a, which has enriched the CRISPR-Cas13a sensing toolbox and will greatly expand its application scope.
Assuntos
Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Sistemas CRISPR-Cas/genética , DNA , DNA de Cadeia SimplesRESUMO
We investigate the discrete Talbot self-imaging effect in Floquet superlattices based on a mesh of directional couplers with periodically varying separation between waveguides, both theoretically and numerically. The modulated discreteness of the lattices sets strong constraints to ensure the Talbot effect generation. We show that discrete Talbot effect occurs only if the incident periods are N = 1, 2, and 4 in dispersive regimes of the Hermitian superlattices. In both dynamic localized and rectification regimes, self-imaging effect can occur for arbitrary input period N. For the rectification case, Talbot distance equals the input period. In the regime of dynamical localization, the Talbot distance remains unchanged irrespective of the pattern period. For non-Hermitian Floquet superlattices, due to the non-zero imaginary part of quasi-energy spectrum arising at the center of the Brillouin zone, where the mode degeneracy occurs, Talbot revival is not preserved when the input period is an even number, and exists only as N = 1 in the dispersive regime. The theoretical calculations and numerical simulations verify each other completely.
RESUMO
We study the dynamics of excitations in dynamically modulated waveguide arrays with an external spatial linear potential. Longitudinally periodic modulation may cause a significant change in the width of the quasi-energy band and leads to the dynamical band suppression with a linear dispersion relation. This substantially affects the Bloch oscillation dynamics. Novel dynamical phenomena with no analogue in ordinary discrete waveguides, named rectified Bloch oscillations, are highlighted. Due to the interplay between directional coupling between adjacent waveguides and diffraction suppression by the introduced onsite energy difference, at odd times of half Bloch oscillations period, the new submodes are continuously excited along two opposite rectification directions and experience same oscillation evolution, and eventually lead to the formation of a diamondlike intensity network. Both the amplitude and direction of the rectified Bloch oscillations strongly depend on the coupling strength. When coupling strength passes the critical value at which dynamical band suppression with a linear dispersion relation occurs, the direction of Bloch oscillations is inverted.
RESUMO
Sluggish CO2 reduction/evolution kinetics at cathodes seriously impede the realistic applications of Li-CO2 batteries. Herein, synergistic photoelectric effect and plasmonic interaction are introduced to accelerate CO2 reduction/evolution reactions by designing a silver nanoparticle-decorated titanium dioxide nanotube array cathode. The incident light excites energetic photoelectrons/holes in titanium dioxide to overcome reaction barriers, and induces the intensified electric field around silver nanoparticles to enable effective separation/transfer of photogenerated carriers and a thermodynamically favorable reaction pathway. The resulting Li-CO2 battery demonstrates ultra-low charge voltage of 2.86â V at 0.10â mA cm-2 , good cycling stability with 86.9 % round-trip efficiency after 100 cycles, and high rate capability at 2.0â mA cm-2 . This work offers guidance on rational cathode design for advanced Li-CO2 batteries and beyond.
RESUMO
The packing material used in acidic biofilters (ABFs) has a significant impact on styrene removal. The bioaerosol emission was rarely considered when evaluating the packing materials in the ABFs. Four ABFs packed with ceramsite, compost, lava and polyurethane (PU) were developed and compared for their styrene removal and fungal bioaerosol emissions characteristics over 529 days. The removal efficiencies of styrene in the ABFs were higher under the condition of longer empty bed residence time (EBRT) and lower inlet concentration. The maximum styrene elimination capacities of the ABFs with ceramsite, compost, lava and PU were 74.57, 87.81, 67.13 and 101.88 g/m3 h, respectively. A lower pressure drop and the highest fungi count were observed in the ABF packed with PU. The emissions concentrations of fungal bioaerosols at the humidity of 63.5% were lower than those at a humidity of 42.7% and it increased with the air velocity. Additionally, the concentrations of fungal bioaerosols emitted from the ABFs packed with PU were 2168 ± 145-3661 ± 257 CFU/m3, which was 33%-90% lower than those of the other three ABFs. The particle size distributions of the fungal bioaerosols emitted from the ABFs packed with PU and compost were mainly centered around large particles. Considering the removal of styrene and the fungal bioaerosols emissions, PU was the optimal packing material for ABF.
Assuntos
Filtração , Estireno , Biodegradação Ambiental , FungosRESUMO
The emergence and worldwide spreads of carbapenemase producing bacteria, especially New Delhi metallo-ß-lactamase (NDM-1), has made a great challenge to treat antibiotics-resistant bacterial infections. It can hydrolyse almost all ß-lactam antibacterials. Unfortunately, there are no clinically useful inhibitors of NDM-1. In this study, structure-based virtual screening method led to the identification of Baicalin as a novel NDM-1 inhibitor. Inhibitory assays showed that Baicalin possessed a good inhibition of NDM-1 with IC50 values of 3.89⯱â¯1.1⯵M and restored the susceptibility of E.coli BL21(DE3)/pET28a-NDM-1 to clinically used ß-lactam antibiotics. Molecular docking and molecular dynamics simulations obtained a complex structure between the relatively stable inhibitor molecule Baicalin and NDM-1 enzyme. The results showed that the carboxyl group in Baicalin directly interacted with the Zn2+ in the active center of the enzyme, and the residues such as Glu152, Gln123, Met67, Trp93 and Phe70 in the enzyme formed hydrogen bonds with Baicalin to further stabilize the complex structure.
Assuntos
Descoberta de Drogas , Flavonoides/farmacologia , Simulação de Dinâmica Molecular , beta-Lactamases/metabolismo , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Escherichia coli/enzimologia , Flavonoides/síntese química , Flavonoides/química , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Wastewater treatment plants (WWTPs) are the leading sources of potential pathogenic bioaerosol that cause non-negligible health risks. However, bioaerosolization behaviour of potential pathogenic microorganisms (PPMs) migrating from wastewater to the atmosphere is still unclear. This study investigated the occurrence profile of PPMs in wastewater, sludge and bioaerosol, then analyzed bioaerosolization level, impact factors and social function. Staphylococcus aureus was selected as the target due to its pathogenicity, and the health risks of workers, engineers and researchers wearing various masks (N90, N95 and medical masks) were evaluated. The results showed that there were 38 and 64 PPMs in bioaerosol from plant A and B. Streptomyces in plant A (average bioaerosolization index, BI= 237.71) and Acinetobacter in plant B (average BI = 505.88) were more likely to migrate from wastewater to the atmosphere forming bioaerosol. Environmental factors (relative humidity, wind speed and temperature) affected both BI and microbial species of PPMs in different ways. PPMs related to fermentation, aerobic chemoheterotrophy, and chemoheterotrophy are the most abundant. Meanwhile microbial networks from plants A and B showed that PPMs were well-connected. Emission level of Staphylococcus aureus bioaerosol can reach 980 ± 309.19 CFU/m3 in plant A and 715.55 ± 44.17 CFU/m3 in plant B. For three exposure population, disease burden (DB) and annual probability infection (Py) of Staphylococcus aureus bioaerosol in two plants were both higher than the U.S.EPA benchmark (10-4 DALYs pppy). All three masks (N90,N95 and medical masks) can decrease Py and DB by at least one order of magnitude. This study illustrated the bioaerosolization behaviour of PPMs comprehensively, which provides a scientific basis for exposure risk prevention and control.
Assuntos
Águas Residuárias , Purificação da Água , Humanos , Microbiologia do Ar , Aerossóis , Esgotos , Staphylococcus aureusRESUMO
Superhydrophobicity-enabled jumping-droplet condensation and frosting have great potential in various engineering applications, ranging from heat transfer processes to antifog/frost techniques. However, monitoring such droplets is challenging due to the high frequency of droplet behaviors, cross-scale distribution of droplet sizes, and diversity of surface morphologies. Leveraging deep learning, we develop a semisupervised framework that monitors the optical observable process of condensation and frosting. This system is adept at identifying transient droplet distributions and dynamic activities, such as droplet coalescence, jumping, and frosting, on a variety of superhydrophobic surfaces. Utilizing this transient and dynamic information, various physical properties, such as heat flux, jumping characteristics, and frosting rate, can be further quantified, conveying the heat transfer and antifrost performances of each surface perceptually and comprehensively. Furthermore, this framework relies on only a small amount of annotated data and can efficiently adapt to new condensation conditions with varying surface morphologies and illumination techniques. This adaptability is beneficial for optimizing surface designs to enhance condensation heat transfer and antifrosting performance.
RESUMO
Photovoltaic devices represent an efficient electricity generation mode. Integrating them into textiles offers exciting opportunities for smart electronic textiles-with the ultimate goal of supplying power for wearable technology-which is poised to change how electronic devices are designed. Many human activities occur indoors, so realizing indoor photovoltaic fibers (IPVFs) that can be woven into textiles to power wearables is critical, although currently unavailable. Here, a dye-sensitized IPVF is constructed by incorporating titanium dioxide nanoparticles into aligned nanotubes to produce close contact and stable interfaces among active layers on a curved fiber substrate, thus presenting efficient charge transport and low charge recombination in the photoanode. With the combination of highly conductive core-sheath Ti/carbon nanotube fiber as a counter electrode, the IPVF shows a certified power conversion efficiency of 25.53% under 1500 lux illuminance. Its performance variation is below 5% after bending, twisting, or pressing for 1000 cycles. These IPVFs are further integrated with fiber batteries as self-charging power textiles, which are demonstrated to effectively supply electricity for wearables, solving the power supply problem in this important direction.
RESUMO
Fiber solar cells as promising wearable power supplies have attracted increasing attentions recently, while further breakthrough on their power conversion efficiency (PCE) and realization of multicolored appearances remain urgent needs particularly in real-world applications. Here, a fiber-dye-sensitized solar cell (FDSSC) integrated with a light diffusion layer composed of alumina/polyurethane film on the outmost encapsulating tube and a light conversion layer made from phosphors/TiO2/poly(vinylidene fluoride-co-hexafluoropropylene) film on the inner counter electrode is designed. The incident light is diffused to more surfaces of fiber electrodes, then converted on counter electrode and reflected to neighboring photoanode, so the FDSSC efficiently takes advantage of the fiber shape for remarkably enhanced light harvesting, producing a record PCE of 13.11%. These efficient FDSSCs also realize color-tunable appearances, improving their designability and compatibility with textiles. They are further integrated with fiber batteries as power systems, providing a power solution for wearables and emerging smart textiles.
RESUMO
Bioconversion using insects has gradually become a promising technology for biowaste management and protein production. However, knowledge about microbiological risk of insect related bioaerosols is sparse and conventional methods failed to provide higher resolved information of environmental microbe. In this study, a metagenomic analysis including microorganisms, antibiotic resistance genes (ARGs), virulence factor genes (VFGs), mobile gene elements (MGEs), and endotoxin distribution in bioaerosols during biowaste conversion via Musca domestica revealed that bioaerosols in Fly rearing room possess the highest ARGs abundances and MGEs diversity. Through a metagenome-assembled genomes (MAGs)-based pipeline, compelling evidence of ARGs/VFGs host assignment and ARG-VFG co-occurrence pattern were provided from metagenomic perspective. Bioaerosols in Bioconversion and Maggot separation zone were identified to own high density of MAGs carrying both ARGs and VFGs. Bacteria in Proteobacteria, Actinobacteriota, and Firmicutes phyla were predominate hosts of ARGs and VFGs. Multidrug-Motility, Multidrug-Adherence, and Beta lactam-Motility pairs were the most common ARG-VFG co-occurrence pattern in this study. Results obtained are of great significance for microbiological risk assessment during housefly biowaste conversion process.
Assuntos
Genes Bacterianos , Moscas Domésticas , Animais , Moscas Domésticas/genética , Metagenoma , Antibacterianos , Bactérias/genética , Metagenômica/métodosRESUMO
Besides the critical role in gene editing, CRISPR/Cas system also brings a new signal amplification mechanism to the development of next generation biosensing technologies. Herein, we have developed a versatile CRISPR/Cas12a sensing platform by combining a target protection-based transcription amplification strategy with the Cas12a-based signal amplification mechanism, which allows for the sensitive detection of both nucleic acid and non-nucleic acid targets. In this design, a rationally designed transcription template sequence is able to avoid Exonuclease I (Exo I) degradation only in the existence of the target-mediated binding events including either nucleic acid hybridization or protein-based affinity interactions. This target binding-induced protection effect can facilitate the subsequent transcription amplification to generate crRNA and activate the subsequent Cas12a trans-cleavage signal amplification mechanism to yield target dosage-responsive fluorescence signal. In contrast, if the target is absent, the protection-free transcription template will be completely digested by Exo I, thus no fluorescence response is produced. This new strategy well eliminates the T7 polymerase-associated non-specific transcription background and realizes the sensitive detection of various kinds of biomolecules including microRNA, protein, as well as exosome, broadening the application scenarios of CRISPR/Cas system in the field of bioanalysis and biosensing.
RESUMO
A novel Chinese-style sausage with Chinese traditional fermented condiments used as additional ingredients is produced in this study. The aim of this study was to investigate the microbial community's structure, the volatile flavor substances and their potential correlation in the novel Chinese sausage. High-throughput sequencing (HTS) and solid-phase microextraction-gas chromatography-mass spectrometry (GC-MS) were, respectively, used to analyze the microbial diversity and volatile flavor substances of the novel Chinese-style sausage during storage. The results showed that Firmicutes, Proteobacteria and Actinobacteria were the predominant bacterial genera, and Hyphopichia and Candida were the predominant fungal genera. A total of 88 volatile flavor substances were identified through GC-MS, among which 18 differential flavor compounds were screened (VIP > 1), which could be used as potential biomarkers to distinguish the novel sausages stored for different periods. Lactobacillus exhibited a significant negative correlation with 2,3-epoxy-4,4-dimethylpentane and acetoin and a significant positive correlation with 2-phenyl-2-butenal. Hyphopichia significantly positively correlated with ester. Leuconostoc significantly positively correlated with ethyl caprate, ethyl palmate, ethyl tetradecanoate and ethyl oleate while it negatively correlated with hexanal. This study provides a theoretical basis for revealing the flavor formation mechanisms and the screening of functional strains for improving the flavor quality of the novel Chinese-style sausage.
RESUMO
Flares are commonly used in municipal solid waste landfills, and the pollution from flare exhaust is usually underestimated. This study aimed to reveal the odorants, hazardous pollutants, and greenhouse gas emission characteristics of the flare exhaust. Odorants, hazardous pollutants, and greenhouse gases emitted from air-assisted flares and a diffusion flare were analyzed, the priority monitoring pollutants were identified, and the combustion and odorant removal efficiencies of the flares were estimated. The concentrations of most odorants and the sum of odor activity values decreased significantly after combustion, but the odor concentration could still exceed 2,000. The odorants in the flare exhaust were dominated by oxygenated volatile organic compounds (OVOCs), while the major odor contributors were OVOCs and sulfur compounds. Hazardous pollutants, including carcinogens, acute toxic pollutants, endocrine disrupting chemicals, and ozone precursors with the total ozone formation potential up to 75 ppmv, as well as greenhouse gases (methane and nitrous oxide with maximum concentrations of 4,000 and 1.9 ppmv, respectively) were emitted from the flares. Additionally, secondary pollutants, such as acetaldehyde and benzene, were formed during combustion. The combustion performance of the flares varied with landfill gas composition and flare design. The combustion and pollutant removal efficiencies could be lower than 90%, especially for the diffusion flare. Acetaldehyde, benzene, toluene, p-cymene, limonene, hydrogen sulfide, and methane could be priority monitoring pollutants for flare emissions in landfills. Flares are useful for odor and greenhouse gas control in landfills, but they are also potential sources of odor, hazardous pollutants, and greenhouse gases.