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The emergence and spread of antibiotic resistance genes (ARGs) induced by the overuse of antibiotics has become a serious threat to public health. Heavy metals will bring longer-term selection pressure to ARGs when the concentration of their residues is higher than that of antibiotics in environmental media. To explore the potential roles of montmorillonite (Mt) in the emergence of ARGs under divalent cadmium ion (Cd2+) stress, Escherichia coli (E. coli) was induced continuously for 15 days under Cd2+ gradient concentrations (16, 32, 64, 96, and 128 µgâmL-1) with and without Mt. Subsequently, antibiotic resistance testing, transcriptomics, transmission electron microscope, scanning electron microscopy, and Fourier transform infrared were conducted for analysis. The results of characterization analysis showed that Cd2+could enhance the expression of resistance genes such as penicillin, tetracycline, macrolactone, and chloramphenicol in E. coli. Moreover, compared with Cd2+, Mt-Cd could inhibit the promotion of these resistances by alleviating the expressions of genes involved in cell wall/membrane, protein synthesis, transport systems, signal transduction, and energy supply processes. Therefore, the study promoted the understanding of Cd2+ in triggering bacterial antibiotic resistance and highlighted a novel theme of clay's ability to mitigate ecological risk of antibiotic resistance caused by heavy metals. KEY POINTS: ⢠Montmorillonite (Mt) could inhibit the promotion of antibiotic resistances. ⢠E. coli formed a unique resistance mechanism by interacting with Mt and Cd2+. ⢠Mt stimulated cellular signal transduction, cellular component, and energy supply.
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Infecções por Escherichia coli , Metais Pesados , Antibacterianos , Bentonita , Cádmio , Farmacorresistência Bacteriana , Escherichia coli , Genes Bacterianos , HumanosRESUMO
Sulforhodamine B (SRB) is widely utilized for cell staining and laser field. But its application is limited by aggregation-caused quenching (ACQ). In this work, we evaluated the use of UiO-66 and UiO-67 of Zr-based metal organic frameworks (Zr-MOFs) as the host to adsorb SRB molecules due to the high stabily and good loading capacity of Zr-MOFs. The fluorescence properties of the compounds were then discussed respectively. Due to the aperture difference between UiO-66 and UiO-67, they showed distinct fluorescence properties after loading SRB. When the concentration reaches 5 ppm, fluorescence quenching begins to occur in SRB@UiO-66, while it occurs in SRB@UiO-67 at 2 ppm. The solution of quenching phenomenon could open new avenues for the extensive use of SRB.
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As a subseries of the covalent organic framework (COF) material family, polyimide-based covalent organic framework (PI-COF) material, which has the advantages of high stability of polyimide, high specific surface area, and controllable pores of COF material, is expected to be a new type of porous material with potential applications. Although the development of PI-COF is in the early stages during the past decade, it has attracted extensive attention and is widely used in heterogeneous catalysis, gas separation, and storage fields. Therefore, this review is aiming to give a comprehensive understanding of the recent progress of PI-COFs. This article summarizes the progress of PI-COF from three aspects: controllable structure design, synthesis method, and application. First of all, under the guidance of network chemical design principles, the topology type of PI-COF and the size and shape of the formed pores are summarized in terms of different organic monomers. Then the five synthetic strategies for the synthesis of PI-COF are analyzed. Finally, the applications of PI-COF in adsorption and separation, drug delivery, solar-to-electrochemical energy storage, photocatalysis, and electrocatalyst are introduced.
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Estruturas Metalorgânicas , Adsorção , Catálise , Sistemas de Liberação de Medicamentos , PorosidadeRESUMO
In this work, corn straw (CS) based porous carbon was prepared by one-step phosphoric acid (H3PO4) low temperature activation. The impregnation ratios (H3PO4/CS, g/g) played an important role in the pore development. ACS300-1 engineered at 300⯰C and the impregnation ratio of 1.0 showed the maximal specific surface area of 463.89â¯m2/g with total pore volume of 0.387â¯cm3/g, attaining a high tetracycline (TC) uptake of 227.3â¯mg/g. The adsorption of TC onto ACS300-1 was found tolerant with wide pH (2.0-10.0) and high ionic strength (0 - 0.5â¯M). The adsorption data can be fitted well by the pseudo-second order kinetic model and Langmuir isotherm model. The endothermic and spontaneous properties of the adsorption system was implied by Thermodynamic study. The findings of the current work conclude that one-step H3PO4 activation is a green and promising method for corn straw based porous carbon that may be found with great potentials in antibiotic containing wastewater treatment.
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Antibacterianos , Carbono , Tetraciclina , Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Ácidos Fosfóricos , Porosidade , Temperatura , Zea maysRESUMO
The aim of this paper was to investigate the effect of total saponins from Panax japonicus( SPJ) on cognitive decline of natural aging rats and its mechanism. Thirty male SD rats of eighteen month old were randomly divided into three groups: aged group,10 mg·kg~(-1) SPJ-treated group and 30 mg·kg~(-1) SPJ-treated group. The SPJ-treated groups were given SPJ at the dosages of 10 mg·kg~(-1) and 30 mg·kg~(-1),respectively,from the age of 18 to 24 months. Aged group were lavaged the same amount of saline,10 six-month-old rats were used as control group,with 10 rats in each group. The open field test,novel object recognition and Morris water maze were performed to detect the changes of cognitive function in each group. The changes of synaptic transmission of long-term potentiation( LTP) in hippocampal CA1 region were detected by field potential recording. Western blot was used to detect the protein levels of NLRP3,ASC,caspase-1 and the changes of Glu A1,Glu A2,CAMKâ ¡,CREB and phosphorylation of CAMKâ ¡,CREB in each group.The results showed that SPJ could improve the decline of cognitive function in aging rats,reduce the damage of LTP in the hippocampal CA1 region of aged rats,and decrease the expression of NLRP3,ASC,caspase-1 in aging rats. At the same time,SPJ could enhance the membrane expression of AMPA receptor( Glu A1 and Glu A2),and increase the expression of p-CAMKâ ¡and p-CREB in aging rats.SPJ could improve cognitive decline of natural aging rats,and its mechanism may be related to regulating NLRP3 inflammasome,thus regulating the membrane expression of AMPA receptor,and enhancing the expression phosphorylation of CAMKâ ¡ and CREB.
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Envelhecimento , Cognição/efeitos dos fármacos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Panax/química , Saponinas/farmacologia , Animais , Região CA1 Hipocampal/fisiologia , Potenciação de Longa Duração , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
In this study, batch experiments were carried out to evaluate the biodegradation of phenol by Sphingomonas sp. GY2B, which were immobilized in polyvinyl alcohol (PVA)-sodium alginate-kaolin beads under different conditions. The optimal degradation performance was achieved by GY2B immobilized in beads containing 1.0% (w/v) of kaolin, 10% (w/v) of PVA, 0.3% (w/v) of sodium alginate, 10% (v/v) of biomass dosage, and exposed to an initial phenol concentration of 100â¯mg/L. The experimental results indicated that PVA-sodium alginate-kaolin beads can accelerate the degradation rate of phenol by reducing the degradation time and also improve degradation rate. The biodegradation rate of phenol by immobilized cells (16.79⯱â¯0.81â¯mg/(L·h)) was significantly higher than that of free cells (11.49⯱â¯1.29â¯mg/(L·h)) under the above optimal conditions. GY2B immobilized on beads was more competent than free GY2B in degradation under conditions with high phenol concentrations (up to 300â¯mg/L) and in strong acidic (pH = 1) and alkaline (pH = 12) environments. Higher phenol concentrations inhibit the biomass and reduce the biodegradation rate, while the lower biodegradation rate at low initial phenol concentrations is attributed to mass transfer limitations. The Haldane inhibitory model was in agreement with the experimental data well, revealing that phenol showed a considerable inhibitory effect on the biodegradation by Sphingomonas sp. GY2B, especially at concentrations higher than 90â¯mg/L. Intra-particle diffusion model analysis suggests that adsorption of phenol by immobilized beads was controlled by both rapid surface adsorption as well as pore diffusion mechanism. It's worth noting that the presence of 1â¯mg/L Cr(VI) enhanced the biodegradation of phenol by free cells, while Cr(VI) showed no obvious impact on the removal of phenol by immobilized cells. In addition, immobilized cells were reused 16 times and removed 99.5% phenol, and when stored at 4⯰C for 90 days, more than 99% phenol was removed. These results showed that immobilized cells can significantly improve the microbial degradation performance, and protect microorganisms against unfavorable environment. It is implied that PVA -sodium alginate-kaolin beads have great potential to be applied in a practical and economical phenolic wastewater treatment system.
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Células Imobilizadas/microbiologia , Caulim/química , Fenol/metabolismo , Fenóis/química , Álcool de Polivinil/química , Sphingomonas/metabolismo , Alginatos/química , Biodegradação Ambiental , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Modelos TeóricosRESUMO
A FeOOH-loaded MnO2 nano-composite was developed as an emergency material for Tl(I) pollution incident. Structural characterizations showed that FeOOH successfully loaded onto MnO2, the nanosheet-flower structure and high surface area (191 m2 g-1) of material contributed to the excellent performance for Tl(I) removal. FeOOH-loaded MnO2 with a Fe/Mn molar ratio of 1:2 exhibited a noticeable enhanced capacity for Tl(I) removal compared to that of pure MnO2. The outstanding performance for Tl(I) removal involves in extremely high efficiency (achieved equilibrium and drinking water standard within 4 min) and the large maximum adsorption capacity (450 mg g-1). Both the control-experiment and XPS characterization proved that the removal mechanism of Tl(I) on FeOOH-loaded MnO2 included adsorption and oxidation: the oxidation of MnO2 played an important role for Tl(I) removal, and the adsorption of FeOOH loaded on MnO2 enhanced Tl(I) purification at the same time. In-depth purification of Tl(I) had reach drinking water standards (0.1 µg L-1) at pH above 7, and there wasn't security risk produced from the dissolution of Mn2+ and Fe2+. Moreover, the as-prepared material could be utilized as a recyclable adsorbent regenerated by using NaOH-NaClO binary solution. Therefore, the synthesized FeOOH-loaded MnO2 in this study has the potential to be applied as an emergency material for thallium pollution incident.
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Tálio , Purificação da Água , Adsorção , Oxirredução , Poluentes Químicos da Água/químicaRESUMO
Laboratory batch experiments were conducted to investigate the role of clay minerals, e.g., kaolinite and vermiculite, in microbial Cr(VI) reduction by Pseudomonas aeruginosa under growth condition in glucose-amended mediums as a method for treating Cr(VI)-contaminated subsurface environment such as soil. Our results indicated that glucose could acted as an essential electron donor, and clay minerals significantly enhanced microbial Cr(VI) reduction rates by improving the consumption rate of glucose and stimulating the growth and propagation of P. aeruginosa. Cr(VI) bioreduction by both free cells and clay minerals-amended cells followed the pseudo-first-order kinetic model, with the latter one fitting better. The mass balance analyses and X-ray photoelectron spectroscopy analysis found that Cr(VI) was reduced to Cr(III) and the adsorption of total chromium on clay minerals-bacteria complex was small, implying that Cr(VI) bioremoval was not mainly due to the adsorption of Cr(VI) onto cells or clay minerals or clay minerals-cells complex but mainly due to the Cr(VI) reduction capacity of P. aeruginosa under the experimental conditions studied (e.g., pH 7). Atomic force microscopy revealed that the addition of clay minerals (e.g. vermiculite) decreased the surface roughness of Cr(VI)-laden cells and changed the cell morphology and dimension. Fourier transform infrared spectroscopy revealed that organic matters such as aliphatic species and/or proteins played an important role in the combination of cells and clay minerals. Scanning electron microscopy confirmed the attachment of cells on the surface of clay minerals, indicating that clay minerals could provide a microenvironment to protect cells from Cr(VI) toxicity and serve as growth-supporting materials. These findings manifested the underlying influence of clay minerals on microbial reduction of Cr(VI) and gave an understanding of the interaction between pollutants, the environment and the biota.
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Silicatos de Alumínio/química , Cromo/metabolismo , Pseudomonas aeruginosa/crescimento & desenvolvimento , Poluentes do Solo/metabolismo , Técnicas de Cultura Celular por Lotes , Biodegradação Ambiental , Carcinógenos Ambientais/metabolismo , Argila , Glucose/metabolismo , Cinética , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/ultraestruturaRESUMO
The potential role of parameters in the reduction of hexavalent chromium [Cr(VI)] by Pseudomonas aeruginosa is not well documented. In this study, laboratory batch studies were conducted to assess the effect of a variety of factors, e.g., carbon sources, salinity, initial Cr(VI) concentrations, co-existing ions and a metabolic inhibitor, on microbial Cr(VI) reduction to Cr(III) by P. aeruginosa AB93066. Strain AB93066 tolerated up to 400 mg/L of Cr(VI) in nutrient broth medium compared to only 150 mg/L of Cr(VI) in nutrient agar. This bacteria exhibited different levels of resistance against Pb(II) (200 mg/L), Cd(II) (100 mg/L), Ni(II) (100 mg/L), Cu(II) (100 mg/L), Co(II) (50 mg/L) and Hg(II) (5 mg/L). Cr(VI) reduction was significantly promoted by the addition of glucose and glycerine but was strongly inhibited by the presence of methanol and phenol. The rate of Cr(VI) reduction increased with increasing concentrations of Cr(VI) and then decreased at higher concentrations. The presence of Ni(II) stimulated Cr(VI) reduction, while Pb(II), Co(II) and Cd(II) had adverse impact on reduction ability of this strain. Cr(VI) reduction was also inhibited by high levels of NaCl, various concentrations of sodium azide and 20 mM of SO4 (2-), MoO4 (2-), NO3 (-), PO4 (3-). No significant relationship was observed between Cr(VI) reduction and redox potential of the culture medium. Scanning electron microscopy showed visible morphological changes in the cells due to chromate stress. Fourier transform infrared spectroscopy analysis revealed chromium species was likely to form complexes with certain functional groups such as carboxyl and amino groups on the surface of P. aeruginosa AB93066. Overall, above results are beneficial to the bioremediation of chromate-polluted industrial wastewaters.
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Carcinógenos Ambientais/metabolismo , Cromo/metabolismo , Metais Pesados/metabolismo , Pseudomonas aeruginosa/crescimento & desenvolvimento , Biodegradação Ambiental , Meios de Cultura/química , Etanol/química , Glucose/química , Glicerol/química , Metanol/química , Microscopia Eletrônica de Varredura , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/ultraestruturaRESUMO
Collagen-based skincare products can replenish collagen in the skin; however, collagen cannot easily penetrate the dermis, limiting its effectiveness. Therefore, nanomaterials that can enable collagen to effectively penetrate the dermis are urgently needed. This study aimed to determine the potential role of the supramolecular collagen nanoparticles, namely, lactoferrin, recombinant human collagen, and palmitoyl tripeptide-5, in improving the effectiveness of skincare products. Lactoferrin and recombinant collagen served as carriers encapsulating palmitoyl tripeptide-5, with an encapsulation rate of 94.18â¯%. The supramolecular collagen nanoparticles demonstrated good stability after 1 month. Transdermal efficiency was improved by 69.90â¯%, allowing the nanoparticles to penetrate deeply into the dermis. Within 28 days of use, the moisture content of the stratum corneum increased by 10.51â¯%, facial elasticity improved by 8.15â¯%, skin firmness increased by 12.53â¯%, facial melanin index decreased by 1.84â¯%, and individual type angle increased by 19.10â¯%. Within 14 days, there was a 24.69â¯% reduction in eye bag wrinkles and a 37.61â¯% reduction in nasolabial wrinkles. Wrinkle lengths decreased by 10.22â¯% and 21.57â¯%, and areas decreased by 34.41â¯% and 27.92â¯%, respectively. The supramolecular collagen nanoparticles displayed multiple skincare benefits, including moisturizing, whitening, wrinkle reduction, and firming. In conclusion, the supramolecular collagen nanoparticles are promising candidates for cosmetic products.
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Biochar (BC) has emerged as a potential solution to phosphate removal from wastewater primarily resulting from global overuse of fertilizers. Further modification by embedment of iron (Fe)-manganese (Mn) oxides on BC can enhance phosphate removal; however, the modification method serves as a vital factor underlying distinctive removal performances and mechanisms, which have yet been systematically examined. Herein, two Fe-Mn modified BC, Fe/MnBC (comprised of Fe3O4 and MnO2) and Fe-MnBC (comprised of MnFe2O4), were comprehensively investigated for gaining insights into the unsolved perspectives. The results indicated that Fe-MnBC exhibited a markedly greater maximum phosphate adsorption capacity of 135.88 mg g-1 than that of Fe/MnBC with 17.93 mg g-1. The comparative results based on microstructure and spectroscopic analyses suggested that different Fe and Mn oxides were successfully loaded, which played a distinctive role in phosphate removal. Further characterizations unveiled that the key mechanisms for phosphate removal by Fe/MnBC are inner-sphere complexation and precipitation, while electrostatic interaction and outer-sphere complexation are the dominant mechanisms underlying the notable performance of Fe-MnBC. The delicately designed Fe-MnBC with special structure and property also enabled a superior regeneration capacity, which presented a promisingly high phosphate removal efficacy of over 81.34% after five cycles. These results enhance comprehension regarding the impact of biochar modification techniques on phosphate removal, offering positive indications for the remediation of excessive phosphate and other pollutant-containing water through feasible design and green chemicals.
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Carvão Vegetal , Ferro , Manganês , Fosfatos , Poluentes Químicos da Água , Carvão Vegetal/química , Fosfatos/química , Manganês/química , Adsorção , Ferro/química , Poluentes Químicos da Água/química , Águas Residuárias/química , Óxidos/química , Compostos de Manganês/química , Purificação da Água/métodosRESUMO
Aeolian sand is widely distributed in the Takramagan Desert, Xinjiang, China, which cannot be directly used as railway subgrade filling. It is beneficial for environmental protection to use fiber and cement-reinforced aeolian sand as railway subgrade filling. The present work is to explore the enhancement of tensile strength in cemented aeolian sand via the incorporation of polypropylene fibers under conditions of elevated temperature and drying curing. The purpose Is to delve into the examination of the temperature's impact on not only the mechanical attributes but also the microstructure of cemented aeolian sand reinforced with polypropylene fiber (CSRPF). For this, a comprehensive set of tests encompassing splitting tensile strength (STS) assessments and nuclear magnetic resonance (NMR) examinations is conducted. A total of 252 CSRPF specimens with varying fiber content (0, 6‱, 8‱, and 10‱) are tested at different curing temperatures (30 °C, 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C). The outcomes of the NMR examinations indicate that elevating the curing temperature induces the expansion of pores within CSRPF, both in size and volume, consequently contributing to heightened internal structural deterioration. STS tests demonstrate that the STS of CSRPF decreases as the curing temperature increases. Meanwhile, the STS of CSRPF increases with fiber content, with optimal fiber content being 8‱. Regression models accurately predict the STS, with the curing temperature exhibiting the greatest influence, followed by the fiber content according to sensitivity analysis. The research results provide a valuable reference for the use of CSRPF as railway subgrade filling under high temperature and drying conditions.
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BACKGROUND: Skip lymph node metastasis (SLNM) refers to lateral lymph node metastasis (LLNM) without involving central lymph node (CLN). Some microscopic nodal positivity may be difficult to detect before surgery due to atypical imaging characteristics. These patients are misdiagnosed as having clinically node-negative (cN0) papillary thyroid cancer (PTC) even after central lymph node dissection, leading to a high risk of developing LNM after surgery. Current prediction models have limited clinical utility, as they are only applicable to predict SLNM from clinically node-positive (cN+) PTC, not cN0 PTC, and this has little impact on treatment strategies. OBJECTIVES: This study aimed to establish a nomogram for preoperatively assessing the likelihood of SLNM in cN0 PTC patients with increased risk of LNM, thus optimizing their therapeutic options. MATERIAL AND METHODS: The records of 780 PTC patients undergoing thyroidectomy along with bilateral central lymph node dissection were retrospectively reviewed. The cN0 patients with postoperative LLNM (occult SLNM) and cN+ patients without central lymph node metastasis (CLNM) (typical SLNM) were included in the SLNM group (n = 82). The CLNM-negative cN0 patients without postoperative LLNM were assigned to the non-SLNM group (n = 698). The independent correlates of SLNM constituted the nomogram for determining the likelihood of SLNM in high-risk cN0 PTC patients. RESULTS: The independent correlates of SLNM were age (hazard ratio (HR) = 1.016), tumor location (HR = 1.801), tumor size (HR = 1.528), and capsular invasion (HR = 2.941). They served as components in the development of the nomogram. This model was verified to present acceptable discrimination. It showed good calibration and a decent net benefit when the predicted probability was <60%. CONCLUSIONS: We developed a nomogram incorporating preoperative clinical data to predict the probability of SLNM development in high-risk cN0 PTC patients, which contributed to their optimized treatment options.
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Carcinoma Papilar , Neoplasias da Glândula Tireoide , Humanos , Câncer Papilífero da Tireoide/patologia , Câncer Papilífero da Tireoide/secundário , Câncer Papilífero da Tireoide/cirurgia , Metástase Linfática/patologia , Neoplasias da Glândula Tireoide/cirurgia , Nomogramas , Estudos Retrospectivos , Carcinoma Papilar/cirurgia , Carcinoma Papilar/patologia , Carcinoma Papilar/secundário , Linfonodos/cirurgia , Linfonodos/patologia , Fatores de RiscoRESUMO
Complex probiotics are made from various single probiotics mixed in scientific formula. The long-term intake of different probiotics is beneficial to maintain the intestinal microecological balance, inhibiting harmful pathogenic flora and facilitating organism health. Based on the limited research on intestinal flora and related metabolites after the long-term intake of the probiotic complex, in this study, 16S rRNA gene sequencing and untargeted metabolomics were used to further investigate the effects of the probiotic complex on the intestinal flora and metabolome of pigs. The results demonstrated that the content of flora in the intestinal tract or metabolites of pigs varied greatly and was related to cellular metabolic pathways after the long-term feeding of complex probiotics. This study provides a valuable theoretical basis for farmers to raise pigs scientifically and healthily.
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The oral hexavalent live human-bovine reassortant rotavirus vaccine (RV6) developed by Wuhan Institute of Biological Products Co., Ltd (WIBP) has finished a randomized, placebo-controlled phase III clinical trial in four provinces of China in 2021. The trail demonstrated that RV6 has a high vaccine efficacy against the prevalent strains and is safe for use in infants. During the phase III clinical trial (2019-2021), 200 rotavirus-positive fecal samples from children with RV gastroenteritis (RVGE) were further studied. Using reverse transcription-polymerase chain reaction and high-throughput sequencing, VP7 and VP4 sequences were obtained and their genetic characteristics, as well as the differences in antigenic epitopes of VP7, were analyzed in detail. Seven rotavirus genotypes were identified. The predominant rotavirus genotype was G9P [8] (77.0%), followed by prevalent strains G8P [8] (8.0%), G3P [8] (3.5%), G3P [9] (1.5%), G1P [8] (1.0%), G2P [4] (1.0%), and G4P [6] (1.0%). The amino acid sequence identities of G1, G2, G3, G4, G8, and G9 genotypes of isolates compared to the vaccine strains were 98.8%, 98.2%-99.7%, 88.4%-99.4%, 98.2%, 94.2%-100%, and 93.9%-100%, respectively. Notably, the vaccine strains exhibited high similarity in amino acid sequence, with only minor differences in antigenic epitopes compared to the Chinese endemic strains. This supports the potential application of the vaccine in preventing diseases caused by rotaviruses.
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Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Animais , Bovinos , Criança , Humanos , Lactente , Antígenos Virais/genética , Proteínas do Capsídeo/genética , China , Epitopos/genética , Fezes , Genótipo , Filogenia , RNA Viral/genética , Rotavirus/genética , Vacinas Combinadas , Ensaios Clínicos Controlados Aleatórios como Assunto , Ensaios Clínicos Fase III como AssuntoRESUMO
The aim of this study was to investigate the effect of roughness and relative density on the mechanical properties of sand-concrete pile interface. A series of direct shear tests were carried out on the interface using a large-scale direct shear apparatus with various relative densities of sand (73%, 47%, and 23%) and concrete blocks with four roughness values (I = 0, 10, 20, and 30 mm). Various mechanical properties (such as shear stress, volume change, peak shear strength, secant friction angle, and normalized friction coefficient) from the interface tests were compared with trends obtained from the pure sand direct shear test. For the smooth interface, the shear stress-horizontal displacement curves of the dense sand specimen exhibited a slight softening response, which became more apparent as the roughness increased. The curves of the loose sand specimen demonstrated a hardening response. The volumetric response was influenced by the combination of normal stress, relative density, and roughness. The peak shear strength demonstrated a nonlinear increasing trend as the normal stress increased. With an increase in the normal stress, the secant friction angle and peak friction coefficient decreased as exponential and power functions, respectively. Additionally, a critical roughness value Icr resulted from the tests, which halted the upward trend of the peak friction coefficient and normalized the secant friction angle when I exceeded Icr.
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Aging is characterized by a progressive deterioration in physiological functions that is associated with cognitive decline as well as other physical functional impairments. Microglia activation leading to neuroinflammation has been generally recognized as playing a critical role in the development of age-related cognitive decline. NLRP3 inflammasome in microglia is fundamental for IL-1ß maturation and subsequent inflammatory events. However, it remains unknown whether NLRP3 activation contributes to aging-induced cognitive decline in vivo. Here, our study demonstrated that aging rats showed declined cognitive function and impaired synaptic plasticity as well as decreased density of dendritic spines. Importantly, our data demonstrated strongly enhanced expression of NLRP3, ASC and Caspase-1 in the hippocampus of aged rats as well as decreased AMPA receptor and phosphorylated levels of CaMKII and CREB in the hippocampus of natural aging rats. Furthermore, NLRP3 inflammasome inhibitor elevated the surface expression of AMPA receptor and the phosphorylated levels of CaMKII, CREB in hippocampus, and finally contributed to the attenuation of hippocampal long-term potentiation (LTP) deficits and the improvement of cognitive decline of natural aging rats. These results revealed an important role for the NLRP3-Caspase-1 pathway in aging-induced cognitive decline and suggested that inhibition of NLRP3 inflammasome represented a novel therapeutic intervention for aging-related cognitive impairment.
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Envelhecimento/fisiologia , Caspase 1/metabolismo , Disfunção Cognitiva/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Plasticidade Neuronal/fisiologia , Animais , Cognição/fisiologia , Inflamassomos/metabolismo , Potenciação de Longa Duração/fisiologia , Microglia/metabolismoRESUMO
A randomized, double-blind, placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a hexavalent live human-bovine reassortant rotavirus vaccine (HRV) against rotavirus gastroenteritis (RVGE). A total of 6400 participants aged 6-12 weeks were enrolled and randomly assigned to either HRV (n â= â3200) or placebo (n â= â3200) group. All the subjects received three oral doses of vaccine four weeks apart. The vaccine efficacy (VE) against RVGE caused by rotavirus serotypes contained in HRV was evaluated from 14 days after three doses of administration up until the end of the second rotavirus season. VE against severe RVGE, VE against RVGE hospitalization caused by serotypes contained in HRV, and VE against RVGE, severe RVGE, and RVGE hospitalization caused by natural infection of any serotype of rotavirus were also investigated. All adverse events (AEs) were collected for 30 days after each dose. Serious AEs (SAEs) and intussusception cases were collected during the entire study. Our data showed that VE against RVGE caused by serotypes contained in HRV was 69.21% (95%CI: 53.31-79.69). VE against severe RVGE and RVGE hospitalization caused by serotypes contained in HRV were 91.36% (95%CI: 78.45-96.53) and 89.21% (95%CI: 64.51-96.72) respectively. VE against RVGE, severe RVGE, and RVGE hospitalization caused by natural infection of any serotype of rotavirus were 62.88% (95%CI: 49.11-72.92), 85.51% (95%CI: 72.74-92.30) and 83.68% (95%CI: 61.34-93.11). Incidences of AEs from the first dose to one month post the third dose in HRV and placebo groups were comparable. There was no significant difference in incidences of SAEs in HRV and placebo groups. This study shows that this hexavalent reassortant rotavirus vaccine is an effective, well-tolerated, and safe vaccine for Chinese infants.
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Infecções por Enterovirus , Gastroenterite , Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Administração Oral , Animais , Bovinos , China , Gastroenterite/epidemiologia , Humanos , Lactente , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/efeitos adversos , Vacinação , Vacinas Atenuadas , Vacinas CombinadasRESUMO
Ampicillin and tetracycline are common antibiotics and can threaten humans by inducing antibiotic resistance in bacteria. Microorganisms are usually exposed to a mixed antibiotic system in the environment. However, there are few researches on the specific regulatory mechanisms of clay on microorganisms under the stress of complex antibiotics. In this study, tandem mass tag-based coupled with two-dimensional liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was employed to recognize and quantify changes in protein expression of Escherichia coli (E. coli) after culture for 15 days, with or without kaolinite in the co-stress of ampicillin and tetracycline. The results indicated that kaolinite could activate metabolic pathways of E. coli such as the energy metabolism, the biosynthesis of other secondary metabolites, and the metabolism of cofactors and vitamins. Particularly, the fatty acid degradation pathway has also been promoted, indicating that in the same unfavorable environment, kaolinite might influence the composition of E. coli cell membranes. This might be due to the change in membrane composition that was a kind of adaptive strategy of bacterial evolution. Moreover, kaolinite could promote multidrug efflux system to export the bacterial intracellular toxic substances, making E. coli survive better in an adverse environment. Consequently, this study not only disclosed the regulation of kaolinite on E. coli in a complex antibiotic environment but also provided new insights into the environmental process of antibiotic resistance.
Assuntos
Escherichia coli , Caulim , Ampicilina/farmacologia , Antibacterianos/farmacologia , Cromatografia Líquida , Humanos , Espectrometria de Massas em Tandem , Tetraciclina/farmacologiaRESUMO
The mechanical properties of artificial skins are complicated to maintain under ensuring air permeability and antimicrobial. Thus, a series of hydrophilic antimicrobial polymer networks are prepared by crosslinking chitosan and polyvinyl alcohol with the lauramidopropyl betaine and hydrogen bond organic framework (CS/PVA/LPB/2D-HOF). The mechanical performance of the control groups and the complex are systematically evaluated to attain an artificial strength skin. The CS/PVA/LPB/2D-HOF complex exhibits strong mechanical abilities than other control groups. By analyzing the IR spectra and the morphology, the synergistic effect of hydrogen bonds between molecules and cracks significantly improves the mechanical properties of the complex. Its maximum tensile strength can reach 29 MPa, and its maximum load capacity can reach 3700 g. Notably, the composite membrane also performs an excellent antimicrobial activity. In vivo and in vitro experiments show that the hybrid membrane can promote tissue regeneration and wound healing (95ï¼ ). These results may open up the opportunity for future composite material investigations in the artificial skin and tissue engineering field.