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The food industry has incurred substantial losses from contamination by Pseudomonas fluorescens, emphasizing the critical importance of implementing effective control strategies. Phages are potential sterilizers due to their specific killing abilities and the difficulty bacteria face in developing resistance. However, a significant barrier to their development is the lack of diversity among phage types. In this study, we characterized a novel lytic P. fluorescens phage, named vB_PF_Y1-MI. Phage vB_PF_Y1-MI displayed a latent period of nearly 10 min and a high burst size of 1493 PFU/cell. This phage showed good activity over a wide range of temperature (up to 70 °C) and pH (3-12). The genome of phage vB_PF_Y1-MI spans 93,233 bp with a GC content of 45%. It encompasses 174 open-reading frames and 19 tRNA genes, while no lysogeny or virulence-associated genes were detected. Phylogenetic analysis positions it as a novel unassigned evolutionary lineage within the Caudoviricetes class among related dsDNA phages. Our study provides foundational insights into vB_PF_Y1-MI and emphasizes its potential as an effective biological control agent against P. fluorescens. This research offers crucial theoretical groundwork and technical support for subsequent efforts in preventing and controlling P. fluorescens contamination.
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Genoma Viral , Leite , Filogenia , Pseudomonas fluorescens , Pseudomonas fluorescens/virologia , Pseudomonas fluorescens/genética , Leite/microbiologia , Leite/virologia , Animais , Genoma Viral/genética , Fagos de Pseudomonas/genética , Fagos de Pseudomonas/isolamento & purificação , Composição de Bases/genética , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Bacteriófagos/classificação , Fases de Leitura Aberta/genéticaRESUMO
Currently, platinum (Pt)/carbon support composite materials have tremendous application prospects in the hydrogen evolution reaction (HER). However, one of the primary challenges for boosting their performance is designing a substrate with the desired microstructure. Herein, the intact hollow carbon spheres (HCSs) were prepared via template method. Based on the morphology variation of the as-prepared HCSs-x, we conjectured that the polydopamine (PDA) core was generated first and then slowly grew into a complete overburden (SiO2@PDA). Afterward, Pt atomic clusters were anchored on the outer shells of HCSs-4 to construct composite electrocatalysts (Pty/HCSs-4) by a chemical reduction method. Due to the low charge-transfer resistance, the HCSs have a large electrochemical surface area and provide a continuous electron transport pathway, boosting the atom utilization efficiency during hydrogen production and release. The synthesized Pt2.5/HCSs-4 electrocatalysts exhibit excellent HER activity in acidic media, which can be ascribed to the compositional modulation and delicate structural design. Specifically, when the overpotential is 10 A g-1, the overpotential can achieve 92 mV. This work opens a new route to fabricate Pt-based electrocatalysts and brings a new understanding of the formation mechanism of HCSs.
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To identify superalkali-alkaline earthide ion pairs, it's theoretically shown that, as a novel class of excess electron superalkali compounds, both chair and boat forms of (AM-HMHC)-AM' (AM = Li, Na, and K; AM' = Be, Mg, and Ca; HMHC = 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane) are good candidates. An attractive superalkali-alkaline earthide ion pair in δ+(AM-HMHC)-AM'δ- is firstly exhibited, which possesses alkaline-earthide characteristics and nonlinear optical response superior to similar M+(calix[4]pyrrole)M'- (M = Li, Na, and K; M' = Be, Mg, and Ca) with high stability. The electronic and vibrational second order hyperpolarizabilities and the frequency-dependent first hyperpolarizabilities of δ+(AM-HMHC)-AM'δ- are presented. For each pair of (AM-HMHC)-AM', the boat conformation is preferred to its chair one in the case of Hyper-Rayleigh scattering response (ßHRS). These alkaline earthides suggest prominently high ßHRS up to 2.59 × 104 a.u. (boat forms of δ+(Na-HMHC)-Caδ-). We expect that this work will inspire the preparation and characterization of these new alkaline earthides as high-performance NLO materials.
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The effect of an oriented external electric field (EEF) on materials has led to the ongoing development, which stimulates us to consider whether intracage microelectric fields (IMEFs) can be used to substitute for the EEF. Focusing on the manipulation and evaluation of the IMEF of asymmetric molecular containers, the host-guest compounds of interesting pineapple-shaped Y@C64X4 (X = vacant, Cl, F, and H; Y = NH4Cl, H3O-Cl, and 2H2O) are theoretically constructed and the strength of the IMEF was evaluated by the intrapotential energy surface analysis by using the point charge (q = +1) scanning method. Interestingly, the left and right halves of each cage are like two IMEFs connected in reverse series. Both the addition of four X atoms and the orientation of the guest can sensitively influence the IMEF's strengths and directions of both half cages and further determine the entire cage's IMEF. Subsequently, the IMEF can sensitively change the binding characteristics and properties of the guest species. Therefore, the manipulation and evaluation of the IMEF can be achievable. This work may provide support for an asymmetric molecular container with an IMEF to manipulate the novel structural and chemical bond characteristics of the guest species.
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The taxonomic relationship between Streptomyces violarus and Streptomyces violaceus was reevaluated using a polyphasic taxonomic approach in this work. Phylogenetic analysis based on 16S rRNA gene sequences indicated that Streptomyces violarus JCM 4534 T was closely related to Streptomyces arenae ISP 5293 T. However, phylogenetic analysis based on five house-keeping gene (atpD, gyrB, recA, rpoB and trpB) showed that the evolutionary neighbor of Streptomyces violarus JCM 4534 T was Streptomyces violaceus CGMCC 4.1456 T, suggesting that there was a close genetic relationship between these two strains. The average nucleotide identity and digital DNA-DNA hybridization values between them were 97.0 and 72.9%, respectively, greater than the 96.7 and 70% cut-off points recommended for delineating a Streptomyces species. This result indicated that they belonged to the same genomic species which was also verified by a comprehensive comparison of phenotypic and chemotaxonomic characteristics between Streptomyces violarus JCM 4534 T and Streptomyces violaceus CGMCC 4.1456 T. According to all these data and the rule of priority in nomenclature, it is proposed the Streptomyces violarus (Artamonova and Krassilnikov 1960) Pridham 1970 is a later heterotypic synonym of Streptomyces violaceus (Rossi Doria 1891) Waksman 1953. In addition, based on dDDH, Streptomyces violaceus and Streptomyces violarus are simultaneously designated as two different subspecies, i.e., Streptomyces violaceus subsp. violaceus and Streptomyces violaceus subsp. violarus.
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DNA Bacteriano , Filogenia , RNA Ribossômico 16S , Streptomyces , Streptomyces/genética , Streptomyces/classificação , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Hibridização de Ácido Nucleico , Proteínas de Bactérias/genéticaRESUMO
OBJECTIVES: To investigate the incidence and characteristics of adult otitis media with effusion (OME) before, during, and after the COVID-19 pandemic. METHODS: A retrospective descriptive study was conducted. The incidence, age, sex, affected ear side, time of OME onset according to COVID-19 and days of improvement after conservative treatment were determined to assess the clinical features of adult OME in different periods of the COVID-19 pandemic. RESULTS: The incidence of adult OME during these periods was 3.17%, 2.30%, 6.18%, and 3.68%, respectively. Unilateral ear involvement and male sex were more common. The onset of adult OME occurred 7.80 ± 3.97 days after COVID-19 diagnosis, and improvement was observed after 12.24 ± 5.08 days of conservative treatment. Patients in the post-pandemic period were older than those in the non-pandemic period. CONCLUSION: The incidence of adult OME in China showed a tendency to decrease, recover, and decrease again following the COVID-19 outbreak. Pandemic prevention and control measures have had a certain impact on reducing the incidence, but the elderly are more prone to this disease.
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COVID-19 , Otite Média com Derrame , Adulto , Humanos , Masculino , Idoso , Recém-Nascido , Otite Média com Derrame/cirurgia , Pandemias , Estudos Retrospectivos , Incidência , Teste para COVID-19 , COVID-19/epidemiologiaRESUMO
Bacterial ghosts (BGs) are described as bacterial cell envelopes that retain their structure but lack cytoplasmic contents. The study of BGs spans multiple disciplinary domains, and the development of BG production techniques to obtain ample and stable BG samples holds significant implications for probing the biological characteristics of BGs, devising novel disease treatment strategies, and leveraging their industrial applications. Numerous products encoded within bacteriophage (phage) genomes possess the capability to lyse bacteria, thereby inducing BG formation primarily via disruption of bacterial cell wall integrity. This review comprehensively surveys the utilization of phage-encoded proteins in BG production techniques, encompassing methodologies such as phage E protein-mediated lysis, perforin protein-induced lysis, and strategies combining E protein with holin-endolysin systems. Additionally, discussions and summaries are provided on the current applications, challenges, and modification strategies associated with different techniques. Through a focused exploration of BG production techniques, with an emphasis on precise manipulation of BG formation using phage-encoded protein technologies, this study aims to furnish robust tools and methodologies for delving into the mechanisms underlying BG formation, as well as for the development of novel therapeutic strategies and applications based on BGs.
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Bactérias , Bacteriófagos , Proteínas Virais , Bacteriófagos/genética , Bacteriófagos/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Bactérias/virologia , Bactérias/metabolismo , Bactérias/genética , Parede Celular/metabolismo , Endopeptidases/metabolismo , BacterióliseRESUMO
Light-driven photoredox catalysis presents a promising approach for the activation and conversion of methane (CH4) into high value-added chemicals under ambient conditions. However, the high C-H bond dissociation energy of CH4 and the absence of well-defined C-H activation sites on catalysts significantly limit the highly efficient conversion of CH4 toward multicarbon (C2+) hydrocarbons, particularly ethylene (C2H4). Herein, we demonstrate a bimetallic design of Ag nanoparticles (NPs) and Pd single atoms (SAs) on ZnO for the cascade conversion of CH4 into C2H4 with the highest production rate compared with previous works. Mechanistic studies reveal that the synergistic effect of Ag NPs and Pd SAs, upon effecting key bond-breaking and -forming events, lowers the overall energy barrier of the activation process of both CH4 and the resulting C2H6, constituting a truly synergistic catalytic system to facilitate the C2H4 generation. This work offers a novel perspective on the advancement of photocatalytic directional CH4 conversion toward high value-added C2+ hydrocarbons through the subtle design of bimetallic cascade catalyst strategy.
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Photo-driven cross-coupling of o-arylenediamines and alcohols has emerged as an alternative for the synthesis of bio-active benzimidazoles. However, tackling the key problem related to efficient adsorption and activation of both coupling partners over photocatalysts towards activity enhancement remains a challenge. Here, we demonstrate an efficient interface synergy strategy by coupling exposed oxygen vacancies (VO) and Pd Lewis acid sites for benzimidazole and hydrogen (H2) coproduction over Pd-loaded TiO2 nanospheres with the highest photoredox activity compared to previous works so far. The results show that the introduction of VO optimizes the energy band structure and supplies coordinatively unsaturated sites for adsorbing and activating ethanol molecules, affording acetaldehyde active intermediates. Pd acts as a Lewis acid site, enhancing the adsorption of alkaline amine molecules via Lewis acid-base pair interactions and driving the condensation process. Furthermore, VO and Pd synergistically promote interfacial charge transfer and separation. This work offers new insightful guidance for the rational design of semiconductor-based photocatalysts with interface synergy at the molecular level towards the high-performance coproduction of renewable fuels and value-added feedstocks.
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Cutibacterium acnes (C. acnes) is a symbiotic bacterium that plays an important role in the formation of acn e inflammatory lesions. As a common component of the acne microbiome, C. acnes phages have the potential to make a significant contribution to treating antibiotic-resistant strains of C. acnes. However, little is known about their genetic composition and diversity. In this study, a new lytic phage, Y3Z, infecting C. acne, was isolated and characterized. Electron microscopy analysis revealed this phage is a siphovirus. Phage Y3Z is composed of 29,160 bp with a GC content of 56.32%. The genome contains 40 open reading frames, 17 of which had assigned functions, while no virulence-related genes, antibiotic resistance genes or tRNA were identified. The one-step growth curve showed the burst size was 30 PFU (plaque-forming unit)/cell. And it exhibited tolerance over a broad range of pH and temperature ranges. Phage Y3Z could infect and lyse all C. acnes isolates tested, though the host range of PA6 was restricted to C. acnes. Based on the phylogenetic and comparative genomic analyses, Y3Z may represent a new siphovirus infecting C. acnes. Characterization of Y3Z will enrich our knowledge about the diversity of C. acnes phages and provide a potential arsenal for thetreatment of acne infection.
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Acne Vulgar , Bacteriófagos , Humanos , Genoma Viral , Filogenia , Propionibacterium acnes/genética , Acne Vulgar/genética , Acne Vulgar/microbiologiaRESUMO
In the present work, the taxonomic relationship between Streptomyces griseomycini and Streptomyces griseostramineus was reevaluated by a comprehensive comparison of phenotypic, chemotaxonomic and genomic characteristics, as well as phylogeny. Phylogenetic analysis based on 16S rRNA gene sequences and whole-genome sequences indicated that Streptomyces griseostramineus JCM 4385T was clustered together with Streptomyces griseomycini JCM 4382T, suggesting they were closely related to each other. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between their genomes were 99.7 and 97.5â%, respectively, much larger than the recommended threshold values of 96.7â% ANI and 70â% dDDH for Streptomyces species delineation. In addition, the morphological, cultural, physio-biochemical and chemotaxonomic features of these two species further demonstrated that they belonged to the same genome species. Based on the above data and the principle of priority in nomenclature, it is proposed that S. griseostramineus (Preobrazhenskaya et al. 1957) Pridham et al. 1958 (Approved Lists 1980) is a later heterotypic synonym of S. griseomycini (Preobrazhenskaya et al. 1957) Pridham et al. 1958 (Approved Lists 1980).
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Ácidos Graxos , Streptomyces , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , Streptomyces/genética , NucleotídeosRESUMO
Two actinomycete strains, designated MG62T and CRLD-Y-1, were isolated from rhizosphere soil of Koelreuteria paniculata and healthy leaves of Xanthium sibiricum, respectively, in Hunan province, PR China. They could produce abundant aerial mycelia that generated rod-shaped spores with spiny surfaces. Morphological features of the two strains are typical of the genus Streptomyces. Strains MG62T and CRLD-Y-1 exhibited 99.93â% 16S rRNA gene sequence similarity. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between them were 99.99 and 100â%, respectively, suggesting that they belonged to the same species. 16S rRNA gene sequences analysis revealed that the two strains belonged to the genus Streptomyces and showed highest similarities to Streptomyces violarus NBRC 13104T (99.07-99.29â%) and Streptomyces arenae ISP 5293T (99.21-99.35â%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains MG62T and CRLD-Y-1 were closely related to S. violarus NBRC 13104T and S. arenae ISP 5293T. However, the ANI, dDDH and multilocus sequence analysis evolutionary distance values between the two strains and their relatives provide a robust basis upon which to verify strains MG62T and CRLD-Y-1 as representing a novel species. Moreover, a comprehensive comparison of phenotypic and chemotaxonomic characteristics further confirmed that the two strains were distinct from their relatives. Based on all these data above, strains MG62T and CRLD-Y-1 should represent a novel Streptomyces species, for which the name Streptomyces koelreuteriae sp. nov. is proposed. The type strain is MG62T (=JCM 34747T=MCCC 1K06175T).
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Streptomyces , Xanthium , Ácidos Graxos/química , Análise de Sequência de DNA , Filogenia , Rizosfera , RNA Ribossômico 16S/genética , Microbiologia do Solo , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Vitamina K 2RESUMO
In recent years, bifunctional electrocatalysts, nanomaterials directly grown on the substrate for application towards the hydrogen evolution reaction (HER), have become of interest for sustainable and clean energy technologies. However, the influence of interfacial interactions between the electrode materials and substrate on device performance remains unclear and is rarely investigated. Herein, we report two-dimensional (2D) CoO nanosheets grown on carbon cloth (CC) (2D CoO/CC) to construct a hybrid electrocatalyst with a seamlessly conductive network. By a series of structure analyses, we recommend that the CoO nanosheets and CC are connected via adsorption. The 2D CoO/CC nanosheets show superior HER performance to the commercial Pt/C and CoO(aq.)/CC nanosheets, including onset potentials of 2 mV, low overpotential of 22 mV at 10 mA cm-2 and Tafel slope of 37 mV dec-1. The results of density functional theory (DFT) calculations reveal that the adsorbability plays an important role in determining the performance of the electrocatalysts for the HER. This work provides a new insight into the interfacial interactions between the electrode material and the substrate in electrochemical devices, and paves the way for the rational design and construction of high-performance electrochemical devices for practical energy applications.
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Chemodynamic therapy of cancer is limited by insufficient endogenous H2O2 generation and acidity in the tumor microenvironment (TME). Herein, we developed a biodegradable theranostic platform (pLMOFePt-TGO) involving composite of dendritic organosilica and FePt alloy, loaded with tamoxifen (TAM) and glucose oxidase (GOx), and encapsulated by platelet-derived growth factor-B (PDGFB)-labeled liposomes, that effectively uses the synergy among chemotherapy, enhanced chemodynamic therapy (CDT), and anti-angiogenesis. The increased concentration of glutathione (GSH) present in the cancer cells induces the disintegration of pLMOFePt-TGO, releasing FePt, GOx, and TAM. The synergistic action of GOx and TAM significantly enhanced the acidity and H2O2 level in the TME by aerobiotic glucose consumption and hypoxic glycolysis pathways, respectively. The combined effect of GSH depletion, acidity enhancement, and H2O2 supplementation dramatically promotes the Fenton-catalytic behavior of FePt alloys, which, in combination with tumor starvation caused by GOx and TAM-mediated chemotherapy, significantly increases the anticancer efficacy of this treatment. In addition, T2-shortening caused by FePt alloys released in TME significantly enhances contrast in the MRI signal of tumor, enabling a more accurate diagnosis. Results of in vitro and in vivo experiments suggest that pLMOFePt-TGO can effectively suppress tumor growth and angiogenesis, thus providing an exciting potential strategy for developing satisfactory tumor theranostics.
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Ferroptose , Neoplasias , Humanos , Linhagem Celular Tumoral , Microambiente Tumoral , Peróxido de Hidrogênio/metabolismo , Neoplasias/tratamento farmacológico , Apoptose , Glucose Oxidase/metabolismoRESUMO
Salmonella enterica contamination is a primary cause of global food poisoning. Using phages as bactericidal alternatives to antibiotics could confront the issue of drug resistance. However, the problem of phage resistance, especially mutant strains with multiple phage resistance, is a critical barrier to the practical application of phages. In this study, a library of EZ-Tn5 transposable mutants of susceptible host S. enterica B3-6 was constructed. After the infestation pressure of a broad-spectrum phage TP1, a mutant strain with resistance to eight phages was obtained. Analysis of the genome resequencing results revealed that the SefR gene was disrupted in the mutant strain. The mutant strain displayed a reduced adsorption rate of 42% and a significant decrease in swimming and swarming motility, as well as a significantly reduced expression of the flagellar-related FliL and FliO genes to 17% and 36%, respectively. An uninterrupted form of the SefR gene was cloned into vector pET-21a (+) and used for complementation of the mutant strain. The complemented mutant exhibited similar adsorption and motility as the wild-type control. These results suggest that the disrupted flagellar-mediated SefR gene causes an adsorption inhibition, which is responsible for the phage-resistant phenotype of the S. enterica transposition mutant.
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Bacteriófagos , Salmonella enterica , Mutação Silenciosa , Mutação , Antibacterianos/farmacologiaRESUMO
Benzimidazoles are a versatile class of scaffolds with important biological activities, whereas their synthesis in a lower-cost and more efficient manner remains a challenge. Here, we demonstrate a conceptually new radical route for the high-performance photoredox coupling of alcohols and diamines to synthesize benzimidazoles along with stoichiometric hydrogen (H2 ) over Pd-decorated ultrathin ZnO nanosheets (Pd/ZnO NSs). The mechanistic study reveals the unique advantage of ZnO NSs over other supports and particularly that the features of Pd nanoparticles in facilitating the cleavage of the α-C-H bond of alcohols and adsorbing subsequently-generated C-centered radicals hold the key to turning on the reaction. This work highlights a new insight into radical-induced efficient benzimidazole synthesis pairing with H2 evolution by rationally designing semiconductor-based photoredox systems.
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To combine both electride and alkalide characteristics in one molecular switch, it is shown herein that the phenalenyl radical and the M3 ring (M3-PHY, M = Li, Na, and K) stacked with parallel and vertical geometries are good candidates. The former geometry is the superalkali electride e-â¯M3+-PHY while the latter geometry is the superalkalide Mδ--M2(1-δ)+-PHY-. The superalkalide Mδ--M2(1-δ)+-PHY- may isomerize to the superalkali electride e-â¯M3+-PHY (M = Li, Na, and K) using suitable long-wavelength irradiation, while the latter may isomerize to the former with suitable short-wavelength irradiation. Also, applying suitable oriented external electric fields can drive the superalkalide Mδ-M2(1-δ)+-PHY- to change into the superalkali electride e-â¯M3+-PHY (M = Li, Na, and K). The differences in the static and dynamic first hyperpolarizability (ß0) values between them were also studied.
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Taihu Lake is the most important drinking water source of the major cities in the Yangtze River Delta. The pollution of endocrine disruptors (EDCs)in Taihu Lake has been increasing recently, the accurate determination is an important guide for predicting its health risks and developing appropriate controls. Monitoring organic pollutants in water using the diffusive gradient in thin film technique (DGT) has attracted much attention due to more accuracy and convenience than the grab sampling methods. In this study, a novel cyclodextrin polymer (CDP) synthesized by the simple and green method in water was taken as an adsorbent for the binding gel. Four endocrine-disrupting chemicals (EDCs), bisphenol A (BPA), 17α-ethinylestradiol (EE2), 17ß-estradiol (E2), and estriol (E3), were taken as models to determine the diffusion coefficients (4.68 × 10-6, 3.38 × 10-6, 3.34 × 10-6 and 4.31 × 10-6 cm2/s) and to test the performance of DGT, such as adsorption capacity and deployment time (1-5 day). The assembled CDP-DGT was adopted to determine four EDCs in a simulated water environment (3-9 of pH, 0.001-0.5 M of ionic strength (IS), and dissolved organic matter (DOM) of 0-20 mg/L). The ability of CDP-DGT sampling was verified in the Jiuxiang River and was carried out for a large-scale field application of in situ sampling EDCs in Taihu Lake basin. The results show that the total EDCs concentration range and the estradiol equivalent concentrations (EEQ) in Taihu Lake and its main rivers are 2.78 ng/L to 11.08 ng/L and 2.62 ng/L to 10.91 ng/L, respectively. The risk quotients (RQs) of all sampling sites in the region were greater than 1, indicating that EDCs pose a serious threat to aquatic organisms in the area. Therefore, the monitoring of EDCs in the Taihu Lake basin should be further strengthened.
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Disruptores Endócrinos , Poluentes Químicos da Água , Celulose , China , Ciclodextrinas , Disruptores Endócrinos/análise , Monitoramento Ambiental/métodos , Estradiol , Géis , Lagos/química , Medição de Risco , Rios/química , Água , Poluentes Químicos da Água/análiseRESUMO
The application of chemodynamic therapy (CDT) for cancer is a serious challenge owing to the low efficiency of the Fenton catalyst and insufficient H2O2 expression in cells. Herein, we fabricated a PDGFB targeting, biodegradable FePt alloy assembly for magnetic resonance imaging (MRI)-guided chemotherapy and starving-enhanced chemodynamic therapy for cancer using PDGFB targeting, pH-sensitive liposome-coated FePt alloys, and GOx (pLFePt-GOx). We found that the Fenton-catalytic activity of FePt alloys was far stronger than that of traditional ultrasmall iron oxide nanoparticle (UION). Upon entry into cancer cells, pLFePt-GOx nanoliposomes degraded into many tiny FePt alloys and released GOx owing to the weakly acidic nature of the tumor microenvironment (TME). The released GOx-mediated glucose consumption not only caused a starvation status but also increased the level of cellular H2O2 and acidity, promoting Fenton reaction by FePt alloys and resulting in an increase in reactive oxygen species (ROS) accumulation in cells, which ultimately realized starving-enhanced chemodynamic process for killing tumor cells. The anticancer mechanism of pLFePt-GOx involved ROS-mediated apoptosis and ferroptosis, and glucose depletion-mediated starvation death. In the in vivo assay, the systemic delivery of pLFePt-GOx showed excellent antitumor activity with low biological toxicity and significantly enhanced T2-weighted magnetic resonance imaging (MRI) signal of the tumor, indicating that pLFePt-GOx can serve as a highly efficient theranostic tool for cancer. This work thus describes an effective, novel multi-modal cancer theranostic system.
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Nanopartículas , Neoplasias , Ligas , Linhagem Celular Tumoral , Glucose , Humanos , Peróxido de Hidrogênio/metabolismo , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-sis/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Microambiente TumoralRESUMO
A novel actinobacterium, designated strain CRSS-Y-16T, was isolated from the healthy leaves of Xanthium sibiricum, in China and characterized by a polyphasic approach. This strain produced abundant aerial mycelia that generated rod-shaped spores with spiny surfaces. The cell wall contained LL-diaminopimelic acid. The major cellular fatty acids (>10.0%) were C16:0, iso-C16:0, and C18:1 ω9c. The predominant menaquinones were MK-9(H2) and MK-9(H4). The detected polar lipids were diphosphatidylglycerol, hydroxyl phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositolmannoside, phospholipids of unknown structure containing glucosamine and unidentified phospholipids. The genomic G+C content was 70.7%. The full-length 16S rRNA gene sequence analysis indicated that strain CRSS-Y-16T belonged to the genus Streptomyces and shared <98.7% sequence similarities with all recognized type species of the genus. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain formed a distinct branch. Phylogenomic analysis demonstrated that it was closely related to Streptomyces panaciradicis 1MR-8T. However, the clustering patterns resulting from phylogenomic tree verified that strain CRSS-Y-16T represented a novel Streptomyces species. This result was further confirmed by low average nucleotide identity and digital DNA-DNA hybridization values (87.54% and 30.1%) between them. Based on all these data, it is concluded that strain CRSS-Y-16T represents a novel Streptomyces species, for which the name Streptomyces spinosirectus sp. nov. is proposed. The type strain is CRSS-Y-16T (=MCCC 1K06950T=JCM 35007T).