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1.
RSC Adv ; 14(21): 14716-14721, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38716097

RESUMO

Halide solid-state electrolytes (SSEs) are considered promising candidates for practical applications in all-solid-state batteries (ASSBs), due to their outstanding high voltage stability and compatibility with electrode materials. However, Na+ halide SSEs suffer from low ionic conductivity and high activation energy, which limit their applications in sodium all-solid-state batteries. Here, sodium yttrium bromide solid-state electrolytes (Na3YBr6) with a low activation energy of 0.15 eV is prepared via solid state reaction. Structure characterization using X-ray diffraction reveals a monoclinic structure (P21/c) of Na3YBr6. First principle calculations reveal that the low migration activation energy comes from the larger size and vibration of Br- anions, both of which expand the Na+ ion migration channel and reduce its activation energy. The electrochemical window of Na3YBr6 is determined to be 1.43 to 3.35 V vs. Na/Na+, which is slightly narrower than chlorides. This work indicates bromides are a good catholyte candidate for sodium all solid-state batteries, due to their low ion migration activation energy and relatively high oxidation stability.

2.
Nat Commun ; 15(1): 4315, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773104

RESUMO

To enable high performance of all solid-state batteries, a catholyte should demonstrate high ionic conductivity, good compressibility and oxidative stability. Here, a LaCl3-based Na+ superionic conductor (Na1-xZrxLa1-xCl4) with high ionic conductivity of 2.9 × 10-4 S cm-1 (30 °C), good compressibility and high oxidative potential (3.80 V vs. Na2Sn) is prepared via solid state reaction combining mechanochemical method. X-ray diffraction reveals a hexagonal structure (P63/m) of Na1-xZrxLa1-xCl4, with Na+ ions forming a one-dimensional diffusion channel along the c-axis. First-principle calculations combining with X-ray absorption fine structure characterization etc. reveal that the ionic conductivity of Na1-xZrxLa1-xCl4 is mainly determined by the size of Na+-channels and the Na+/La3+ mixing in the one-dimensional diffusion channels. When applied as a catholyte, the NaCrO2||Na0.7Zr0.3La0.7Cl4||Na3PS4||Na2Sn all-solid-state batteries demonstrate an initial capacity of 114 mA h g-1 and 88% retention after 70 cycles at 0.3 C. In addition, a high capacity of 94 mA h g-1 can be maintained at 1 C current density.

3.
Protein Expr Purif ; 220: 106502, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38754753

RESUMO

Adeno-associated Virus (AAV) is a promising vector for gene therapy. However, few studies have focused on producing virus-like particles (VLPs) of AAV in cells, especially in E. coli. In this study, we describe a method to produce empty VP3-only VLPs of AAV2 in E. coli by co-expressing VP3 and assembly-activating protein (AAP) of AAV2. Although the yields of VLPs produced with our method were low, the VLPs were able to self-assemble in E. coli without the need of in vitro capsid assembly. The produced VLPs were characterized by immunological detection and transmission electron microscopy (TEM). In conclusion, this study demonstrated that capsid assembly of AAV2 is possible in E. coli, and E. coli may be a candidate system for production of VLPs of AAV.


Assuntos
Proteínas do Capsídeo , Dependovirus , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Dependovirus/genética , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/biossíntese , Vírion/genética , Vírion/metabolismo , Montagem de Vírus , Vetores Genéticos/metabolismo , Vetores Genéticos/genética , Vetores Genéticos/química , Parvovirinae/genética , Humanos
4.
Chem Soc Rev ; 53(3): 1514-1551, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38167899

RESUMO

Protein-based bioactive coatings have emerged as a versatile and promising strategy for enhancing the performance and biocompatibility of diverse biomedical materials and devices. Through surface modification, these coatings confer novel biofunctional attributes, rendering the material highly bioactive. Their widespread adoption across various domains in recent years underscores their importance. This review systematically elucidates the behavior of protein-based bioactive coatings in organisms and expounds on their underlying mechanisms. Furthermore, it highlights notable advancements in artificial synthesis methodologies and their functional applications in vitro. A focal point is the delineation of assembly strategies employed in crafting protein-based bioactive coatings, which provides a guide for their expansion and sustained implementation. Finally, the current trends, challenges, and future directions of protein-based bioactive coatings are discussed.


Assuntos
Materiais Revestidos Biocompatíveis
5.
Small ; 20(5): e2305649, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37752691

RESUMO

In situ polymerization to prepare quasi-solid electrolyte has attracted wide attentions for its advantage in achieving intimate electrode-electrolyte contact and the high process compatibility with current liquid batteries; however, gases can be generated during polymerization process and remained in the final electrolyte, severely impairing the electrolyte uniformity and electrochemical performance. In this work, an in situ polymerized poly(vinylene carbonate)-based quasi-solid electrolyte for high-voltage sodium metal batteries (SMBs) is demonstrated, which contains a novel multifunctional additive N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA). MSTFA as high-efficient plasticizer diminishes residual gases in electrolyte after polymerization; the softer and homogeneous electrolyte enables much faster ionic conduction. The HF/H2 O scavenge effect of MSTFA mitigates the corrosion of free acid to cathode and interfacial passivating layers, enhancing the cycle stability under high voltage. As a result, the 4.4 V Na||Na3 V2 (PO4 )2 F3 cell employing the optimized electrolyte possesses an initial discharge capacity of 112.0 mAh g-1 and a capacity retention of 91.3% after 100 cycles at 0.5C, obviously better than those of its counterparts without MSTFA addition. This work gives a pioneering study on the gas residue phenomenon in in situ polymerized electrolytes, and introduces a novel multifunctional silane additive that effectively enhances electrochemical performance in high-voltage SMBs, showing practical application significance.

6.
Psychol Psychother ; 97(1): 173-186, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37902282

RESUMO

OBJECTIVE: This study investigates the impact of mindful parenting on child behaviour problems and examines the chain mediating role of parental and child communicating performance in this relationship. METHODS: A 10-month follow-up survey was conducted, utilizing the Interpersonal Mindfulness in Parenting Scale (IM-P), the Parent-Child Communication Inventory, and the abbreviated version of the Child Behaviour Checklist (CBCL). RESULTS: At baseline (T1), higher levels of mindful parenting in parents were significantly and positively associated with both T1 parental communicating performance and child communicating performance. After 10 months, all three variables showed significant negative associations with child behaviour problems. T1 parental communication performance positively correlated with T1 child communication performance. After controlling for T1 child behaviour problems, children's gender and age, and parents' gender, the indirect association between T1 parents' levels of mindful parenting and T2 child behaviour problems was significant, mediated by T1 parental communicating performance and T1 child communicating performance. CONCLUSION: Mindful parenting enhances parental communication behaviour, leading to improved child communication behaviour and reduced child behaviour problems.


Assuntos
Atenção Plena , Comportamento Problema , Humanos , Criança , Poder Familiar , Pais , Comportamento Infantil
7.
J Colloid Interface Sci ; 645: 227-240, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37149997

RESUMO

The mild and rapid construction of economical, efficient and ultrastable electrodes for hydrogen production via water splitting at industrial-grade current density remains extremely challenging. Herein, a one-step mild electroless plating method is proposed to deposit cobalt phosphorus (CoP)-based species on robust nickel net (NN, denoted as Co-P@NN). The tight interfacial contact, corrosion-proof self-supporting substrate and synergistic effect of Co-P@Co-O contribute greatly to the rapid electron transport, high intrinsic activity and long-term durability in the alkaline simulated seawater (1.0 M KOH + 0.5 M NaCl). Attractively, Co-P@Co-O also achieves ultrastable catalysis for over 2880 h with negligible activity attenuation under various alkaline extreme conditions (simulated seawater, high-salt environment, domestic sewage and so on). Furthermore, this work successfully constructs a series of ternary elemental doped (Ni, S, B, Fe and so on) CoP-based catalytic electrodes for highly efficient overall seawater splitting (OSWS). This work demonstrates not only an ideal platform for the versatile strategy of mildly obtaining CoP-based electrocatalysts but also the pioneering philosophy of large-scale hydrogen production.

8.
Colloids Surf B Biointerfaces ; 225: 113239, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36889106

RESUMO

Coatings with both anti-fouling and bactericidal functions are used in many fields. In this work, lysozyme (Lyso) and poly (2-Methylallyloxyethyl phosphorylcholine) (PMPC) conjugate (Lyso-PMPC) is successfully designed and synthesized for the first time. A new nanofilm (PTL-PMPC) is then obtained by phase transition of lysozyme via the reduction of disulfide bonds in Lyso-PMPC. Benefit from lysozyme amyloid-like aggregates as surface anchors, the nanofilm shows excellent stability, it remains unchanged after treatment under extreme conditions such as ultrasonic and 3 M tape peeling. Due to the presence of zwitterionic polymer (PMPC) brush, the PTL-PMPC film has excellent antifouling properties against cell, bacterium, fungi, proteins, biofluids, phosphatide, polyose, esters, and carbohydrates. Meanwhile, the PTL-PMPC film is colourless and transparent. Further, a new coating (PTL-PMPC/PHMB) is fabricated by hybridizing PTL-PMPC with poly (hexamethylene biguanide) (PHMB). This coating had excellent antibacterial properties, and the antibacterial rate against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) is more than 99.99%. In addition, the coating exhibit good hemocompatibility and low cytotoxicity.


Assuntos
Incrustação Biológica , Muramidase , Muramidase/farmacologia , Incrustação Biológica/prevenção & controle , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacologia , Antibacterianos/química
9.
ACS Appl Mater Interfaces ; 15(8): 10426-10440, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36791143

RESUMO

Polyetheretherketone (PEEK), a widely used implant material, has attracted the attention of scientific researchers because of its bone-matched elastic modulus, radiolucency, and chemical resistance. However, the bioinert chemical properties of PEEK do not promote bone apposition once implanted. In this study, using a phase-transitioned lysozyme (PTL) nanofilm as a sandwiched layer, a robust hydroxyapatite (HAp) coating on PEEK (HAp@PTL@PEEK) is constructed. The PTL nanofilm shows strong adhesion to the PEEK surface and induces biomimetic mineralization to form a compact HAp coating on PEEK in simulated body fluids. This HAp coating not only shares a higher adhesion strength and better stability but can also be applied to implants with complex 3D structures. HAp@PTL@PEEK showed significantly enhanced osteogenic capacity when cultured with rat bone marrow mesenchymal stem cells by promoting initial cell adhesion, proliferation, and osteogenic differentiation in vitro. In vivo evaluations utilizing models of femoral condyle defects and skull defects confirm that the HAp coating substantially augments bone remodeling and osseointegration ability. Compared with the traditional method, our modified method is simpler, more environmentally friendly, and uses less hazardous components. Furthermore, the obtained HAp coating shares a higher adhesion strength to PEEK and a better osteogenic capacity. The study offers a novel method to improve the osseointegration of PEEK-based implants in biointerfaces and tissue engineering.


Assuntos
Osseointegração , Osteogênese , Ratos , Animais , Biomimética , Polímeros , Polietilenoglicóis/química , Benzofenonas , Cetonas/química , Durapatita/química , Propriedades de Superfície
10.
J Colloid Interface Sci ; 634: 804-816, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36565622

RESUMO

It is essential to construct self-supporting electrodes based on earth-abundant iron borides in a mild and economical manner for grid-scale hydrogen production. Herein, a series of highly efficient, flexible, robust, and scalable Fe-B-O@FeBx modified on hydrophilic cloth (denoted as Fe-B-O@FeBx/HC, 10 cm × 10 cm) are fabricated by mild electroless plating. The overpotentials and Tafel slope values for the hydrogen and oxygen evolution reactions are 59 mV and 57.62 mV dec-1 and 181 mV and 65.44 mV dec-1, respectively; only 1.462 V is required to achieve 10 mA cm-2 during overall water splitting (OWS). Fe-B-O@FeBx/HC maintains its high catalytic activity for more than 7 days at an industrial current density (400 mA cm-2), owing to the loosened popcorn-like Fe-B-O@FeBx that is firmly loaded on a 2D-layered and mechanically robust substrate along with its fast charge and mass transfer kinetics. The chimney effect of core-shell borides@(oxyhydro)oxides enhances the OWS performance and protects the inner metal borides from further corrosion. Moreover, the flexible Fe-B-O@FeBx/HC electrode has a low cost for grid-scale hydrogen production ($2.97 kg-1). The proposed strategy lays a solid foundation for universal preparation, large-scale hydrogen production and practical applications thereof.

11.
Small ; 19(11): e2205689, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36585395

RESUMO

Designing nonprecious metal-based electrocatalysts to yield sustainable hydrogen energy by large-scale seawater electrolysis is challenging to global emissions of carbon neutrality and carbon peaking. Herein, a series of highly efficient, economical, and robust Ni-P-based nanoballs grown on the flexible and anti-corrosive hydrophobic asbestos (NiPx @HA) is synthesized by electroless plating at 25 °C toward alkaline simulated seawater splitting. On the basis of the strong chemical attachment between 2D layered substrate and nickel-rich components, robust hexagonal Ni5 P4 crystalline modification, and fast electron transfer capability, the overpotentials during hydrogen/oxygen evolution reaction (HER/OER) are 208 and 392 mV at 200 mA cm-2 , and the chronopotentiometric measurement at 500 mA cm-2 lasts for over 40 days. Additionally, the versatile strategy is broadly profitable for industrial applications and enables multi-elemental doping (iron/cobalt/molybdenum/boron/tungsten), flexible substrate employment (nickel foam/filter paper/hydrophilic cloth), and scalable synthesis (22 cm × 22 cm). Density functional theory (DFT) also reveals that the optimized performance is due to the fundamental effect of incorporating O-source into Ni5 P4 . Therefore, this work exhibits a complementary strategy in the construction of NiPx -based electrodes and offers bright opportunities to produce scalable hydrogen effectively and stably in alkaline corrosive electrolytes.

12.
Small ; 18(47): e2203588, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36287089

RESUMO

Mild construction of highly efficient and durable practical electrodes for overall water splitting (OWS) at industrial-grade current density is currently a significant challenge. Herein, metal-organic framework (MOF) materials are grown in situ on the surface of carbon cloth (CC) at 25 °C, and quickly "interspersed" by cobalt-boron (Co-B) via electroless plating for 30 min to obtain a highly efficient and stable CoB@MOF@CC self-supporting electrode. Owing to the large specific surface area, abundant active sites, and porous structure, the MOF-based CC modified by bamboo leaf-like ultrathin CoB has remarkable electrochemical catalysis efficiency. The CoB@MOF@CC electrode exhibits excellent performance during the hydrogen evolution reaction (η10  = 57 mV, η500  = 266 mV) and oxygen evolution reaction (η10  = 209 mV, η500  = 423 mV) in alkaline simulated seawater, and is durable for 2500 h at 500 mA cm-2 . The OWS performance is obviously enhanced by employing the prepared electrode, which only requires 1.49 V to achieve 10 mA cm-2 and is durable for over 360 h at industrial-grade current densities in alkaline high-salt, real seawater, rainwater, and urea electrolytes.


Assuntos
Estruturas Metalorgânicas , Tato , Catálise , Eletrodos , Água/química , Carbono , Água do Mar
13.
J Colloid Interface Sci ; 626: 384-394, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35803138

RESUMO

The development of fast and mild preparation of transition metal electrocatalysts for efficient and ultra-stable water electrolysis in wide pH range electrolytes is essential for hydrogen energy supply. Herein, ultrathin and metastable FeS nanolayer self-supported on 3D porous iron foam (IF) substrate is fabricated via one-step mild sulfurization etching for only 2 h to obtain FeS@IF electrode, which achieves efficient and long-term hydrogen evolution in alkaline simulated seawater (1.0 M KOH + 0.5 M NaCl), neutral electrolyte (1.0 M PBS) and other corrosive systems. The overpotentials are only 63 mV and 78 mV to drive 10 mA cm-2 during hydrogen evolution in 1.0 M KOH + 0.5 M NaCl and 1.0 M PBS, respectively. Additionally, the FeS@IF electrode continuously catalyzes for over 600 h at 0.2-0.4 A cm-2 in 1.0 M PBS with negligible performance loss, partly attributed to FeS nanolayer firmly etching on the surface and the formation of corrosion-resistant ultrathin nano fan-like iron sulfide oxide (FeOxSy). This uniformly-distributed morphology helps to facilitate the interfacial electron transmission between active species and substrate, expose more active sites, and provide moderate channels for the rapid liberation of gas bubbles and mass transfer. This work proposes a novel strategy for developing efficient and stable catalysts for hydrogen production in wide pH range systems.

14.
Adv Sci (Weinh) ; 9(13): e2105106, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35257513

RESUMO

Pesticide overuse is a major global problem and the cause of this problem is noticeable pesticide loss from undesired bouncing of sprayed pesticide droplets and rain erosion. This further becomes a primary source of soil and groundwater pollution. Herein, the authors report a method that can enhance pesticide droplet deposition and adhesion on superhydrophobic plant leave surfaces by amyloid-like aggregation of bovine serum albumin (BSA). Through the reduction of the disulfide bond of BSA by tris(2-carboxyethyl) phosphine hydrochloride (TCEP), the amyloid-like phase transition of BSA is triggered that rapidly affords abundant phase-transitioned BSA (PTB) oligomers to facilitate the invasion of the PTB droplet into the nanostructures on a leaf surface. Such easy penetration is further followed by a robust amyloid-mediated interfacial adhesion of PTB on leaf surface. As a result, after mixing with pesticides, the PTB system exhibits a remarkable pesticide adhesion capacity that is more than 10 times higher than conventional fixation of commercial pesticides. The practical farmland experiments show that the use of PTB aggregation could reduce the use of pesticides by 70-90% while ensuring yield. This work demonstrates that current pesticide dosage in actual agriculture production may be largely reduced by utilizing eco-friendly amyloid-like protein aggregation.


Assuntos
Praguicidas , Agricultura , Amiloide/química , Proteínas Amiloidogênicas , Praguicidas/química , Agregados Proteicos , Soroalbumina Bovina/química
15.
Gene ; 760: 145017, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32755655

RESUMO

Cytoplasmic vacuolization usually occurs in cells treated with different agents and substances. We found that LZ-106, an analog of enoxacin, is a potent lysosomotropic agent, contributing to the formation of cytoplasmic vacuoles in cells. Studies of LZ-106-induced vacuolization in H460 cells showed acid environment inside these vacuoles. Further study demonstrated that markers in the late endosomes and lysosomes, like LAMP1 and RAB7, on the surface of the vacuoles, implying that these vacuoles might derive from endosomes and/or lysosomes. By studying the fluorescence intensity of LZ-106, we discovered that LZ-106 tended to locate in acid organelles, and Bafilomycin A1, a V-ATPase inhibitor, was able to suppress its acid organelles localization. Also, we noticed that LZ-106 could induce lysosome stress, involving pH increment and lysosomal membrane damage. Moreover, the expression levels of some lysosome-related proteins, like LAMP1, EEA1, and Cathepsin B, were also altered upon LZ-106 treatment. At last, we confirmed LZ-106 can activate TFEB, a key regulator of lysosomes. Knockdown of TFEB could also reverse LZ-106's effect on vacuolization in H460 cells. Taken together, due to LZ-106's lysosomotropic properties, it is able to accumulate in the acid organelles and induce lysosomal dysfunction in H460 cells, leading to TFEB activation and the following cytoplasmic vacuolization.


Assuntos
Enoxacino/análogos & derivados , Enoxacino/farmacologia , Vacúolos/efeitos dos fármacos , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Linhagem Celular Tumoral , Citoplasma/metabolismo , Endossomos/metabolismo , Humanos , Lisossomos/química , Macrolídeos/farmacologia
16.
Carcinogenesis ; 40(1): 131-144, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30239617

RESUMO

LZ-106, a newly synthetized analog of quinolone, has been shown to be highly effective in non-small cell lung cancer (NSCLC) in both cultured cells and xenograft mouse model with low toxicity, yet the molecular mechanisms still require exploration. Here, we substantiated the involvement of P53 activation in intracellular reactive oxygen species (ROS) generation upon LZ-106 treatment and related P53 to the ROS-induced viability inhibition and apoptosis, which was exhibited in the previous research. P53 was shown to play an indispensable role in the elevated levels of intracellular ROS in LZ-106-treated NSCLC cells through ROS detection. We further identified the anti-proliferation effect of LZ-106 in NSCLC cells through G1 phase cell cycle arrest by cell cycle analysis, with the expression analysis of the key proteins, and discovered that the cell cycle arrest effect is also mediated by induction of ROS in a P53-dependent manner. In addition, the tumor suppression effect exhibited in vivo was demonstrated to be similar to that in vitro, which requires the participation of P53. Thus, LZ-106 is a potent antitumor drug possessing potent proliferation inhibition and apoptosis induction ability through the P53-dependent ROS modulation both in vitro and in vivo.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Enoxacino/análogos & derivados , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/fisiologia , Animais , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
17.
J Food Prot ; 81(4): 528-533, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29513103

RESUMO

The aim of this study was to investigate the toxin gene profile and antimicrobial resistance of Staphylococcus aureus isolates from raw chicken in the People's Republic of China. In total, 289 S. aureus isolates were characterized by antimicrobial susceptibility testing, and genes encoding enterotoxins, exfoliative toxins, Panton-Valentine leukocidin, and toxic shock syndrome toxin were revealed by PCR. Overall, 46.0% of the isolates were positive for one or more toxin genes. A high proportion of toxin genes were pvl (26.6%), followed by sej (12.5%), sea (9.0%), seh (8.3%), seb (6.9%), sec (6.9%), sed (4.8%), sei (3.1%), and see (2.4%). None of the isolates harbored seg, tsst-1, or exfoliative toxin genes. In total, 29 toxin gene profiles were obtained, and pvl (10.7%) was the most frequent genotype, followed by sea (5.9%), seb (4.8%), and sej (4.2%). Furthermore, 99.7% of the strains were resistant to at least one of the tested antimicrobial agents, and 87.2% of them displayed multidrug resistance. Resistance was most frequently observed to trimethoprim-sulfamethoxazole and erythromycin (86.2% for each), followed by tetracycline (69.9%), amoxicillin-clavulanic acid (45.0%), and ampicillin (42.6%). None of the strains were resistant to vancomycin. This study indicates that S. aureus isolates from raw chicken harbored multiple toxin genes and exhibited multiple antimicrobial resistance, which represents a potential health hazard for consumers.


Assuntos
Toxinas Bacterianas/genética , Carne/microbiologia , Staphylococcus aureus/genética , Animais , Antibacterianos/farmacologia , Galinhas , China , Microbiologia de Alimentos , Genes Bacterianos , Reação em Cadeia da Polimerase , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
18.
Appl Opt ; 56(26): 7358-7366, 2017 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-29048057

RESUMO

Risley prisms appear to be a promising solution to high-accuracy pointing and tracking. To improve the pointing accuracy of achromatic Risley prisms, an appropriate mathematical model is established, and the forward and inverse solutions are proposed. Focusing on the sources of systematic errors, an optimization method based on a genetic algorithm is proposed to identify the parameters of the physical model, including wedge angles, refractive indexes, and installations. Finally, the experimental platform is established. The pointing accuracy and the size of the blind zone are tested to prove the validity of the method. Experimental results show that the proposed method is effective to reduce the influence of manufacturing, installation, and measurement errors. The optimized pointing accuracy has been improved significantly. Within the maximum deflection angle of 3°, the maximum pointing error is reduced from 33 arcsec to less than 1 arcsec. And the angular dynamic range is found to be greater than 43 dB, able to meet the needs of the majority of applications. In addition, the test of the blind zone shows that the optimized parameters are consistent with the actual system.

19.
Sensors (Basel) ; 17(3)2017 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-28264504

RESUMO

The charge couple device (CCD) tracking loop of a fast steering mirror (FSM) is usually used to stabilize line of sight (LOS). High closed-loop bandwidth facilitates good performance. However, low-rate sample and time delay of the CCD greatly limit the high control bandwidth. This paper proposes an error-based observer (EBO) to improve the low-frequency performance of the CCD tracking system. The basic idea is by combining LOS error from the CCD and the controller output to produce the high-gain observer, forwarding into the originally closed-loop control system. This proposed EBO can improve the system both in target tracking and disturbance suppression due to LOS error from the CCD's sensing of the two signals. From a practical engineering view, the closed-loop stability and robustness of the EBO system are investigated on the condition of gain margin and phase margin of the open-loop transfer function. Two simulations of CCD experiments are provided to verify the benefits of the proposed algorithm.

20.
Sensors (Basel) ; 16(7)2016 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-27347970

RESUMO

A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm.

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