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1.
Anal Chem ; 96(10): 4282-4289, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38469640

RESUMEN

Chirality is a widespread phenomenon in nature and in living organisms and plays an important role in living systems. The sensitive discrimination of chiral molecular enantiomers remains a challenge in the fields of chemistry and biology. Establishing a simple, fast, and efficient strategy to discriminate the spatial configuration of chiral molecular enantiomers is of great significance. Chiral perovskite nanocrystals (PNCs) have attracted much attention because of their excellent optical activity. However, it is a challenge to prepare perovskites with both chiral and fluorescence properties for chiral sensing. In this work, we synthesized two chiral fluorescent perovskite nanocrystal assembly (PNA) enantiomers by using l- or d-phenylalanine (Phe) as chiral ligands. PNA exhibited good fluorescence recognition for l- and d-proline (Pro). Homochiral interaction led to fluorescence enhancement, while heterochiral interaction led to fluorescence quenching, and there is a good linear relationship between the fluorescence changing rate and l- or d-Pro concentration. Mechanism studies show that homochiral interaction-induced fluorescence enhancement is attributed to the disassembly of chiral PNA, while no disassembly of chiral PNA was found in heterochiral interaction-induced fluorescence quenching, which is attributed to the substitution of Phe on the surface of chiral PNA by heterochiral Pro. This work suggests that chiral perovskite can be used for chiral fluorescence sensing; it will inspire the development of chiral nanomaterials and chiral optical sensors.

2.
Appl Environ Microbiol ; 90(8): e0069524, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39078126

RESUMEN

While the distribution of extracellular ARGs (eARGs) in the environment has been widely reported, the factors governing their release remain poorly understood. Here, we combined multi-omics and direct experimentation to test whether the release and transmission of eARGs are associated with viral lysis and heat during cow manure composting. Our results reveal that the proportion of eARGs increased 2.7-fold during composting, despite a significant and concomitant reduction in intracellular ARG abundances. This relative increase of eARGs was driven by composting temperature and viral lysis of ARG-carrying bacteria based on metagenome-assembled genome (MAG) analysis. Notably, thermal lysis of mesophilic bacteria carrying ARGs was a key factor in releasing eARGs at the thermophilic phase, while viral lysis played a relatively stronger role during the non-thermal phase of composting. Furthermore, MAG-based tracking of ARGs in combination with direct transformation experiments demonstrated that eARGs released during composting pose a potential transmission risk. Our study provides bioinformatic and experimental evidence of the undiscovered role of temperature and viral lysis in co-driving the spread of ARGs in compost microbiomes via the horizontal transfer of environmentally released DNA. IMPORTANCE: The spread of antibiotic resistance genes (ARGs) is a critical global health concern. Understanding the factors influencing the release of extracellular ARGs (eARGs) is essential for developing effective strategies. In this study, we investigated the association between viral lysis, heat, and eARG release during composting. Our findings revealed a substantial increase in eARGs despite reduced intracellular ARG abundance. Composting temperature and viral lysis were identified as key drivers, with thermal lysis predominant during the thermophilic phase and viral lysis during non-thermal phases. Moreover, eARGs released during composting posed a transmission risk through horizontal gene transfer. This study highlights the significance of temperature and phage lysis in ARG spread, providing valuable insights for mitigating antibiotic resistance threats.


Asunto(s)
Compostaje , Transferencia de Gen Horizontal , Estiércol/microbiología , Estiércol/virología , Microbiología del Suelo , Bacterias/genética , Bacterias/efectos de los fármacos , Animales , Metagenoma , Bovinos , Calor , Genes Bacterianos , Farmacorresistencia Microbiana/genética , Farmacorresistencia Bacteriana/genética , Microbiota , Bacteriófagos/genética , Bacteriófagos/fisiología
3.
Artículo en Inglés | MEDLINE | ID: mdl-38323900

RESUMEN

Three microaerophilic bacterial strains, designated SG22T, SG63T and SG29T were isolated from paddy soils in PR China. Cells of these strains were Gram-staining-negative and long rod-shaped. SG22T, SG63T and SG29T showed the highest 16S rRNA gene sequence similarities with the members of the genus Anaeromyxobacter. The results of phylogenetic and phylogenomic analysis also indicated that these strains clustered with members of the genus Anaeromyxobacter. The main respiratory menaquinone of SG22T, SG63T and SG29T was MK-8 and the major fatty acids were iso-C15 : 0, iso-C17 : 0 and C16 : 0. SG22T, SG29T and SG63T not only possessed iron reduction ability but also harboured genes (nifHDK) encoding nitrogenase. The genomic DNA G+C contents of SG22T, SG63T and SG29T ranged from 73.3 to 73.5 %. The average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) values between SG22T, SG63T and SG29T and the closely related species of the genus Anaeromyxobacter were lower than the cut-off values (dDDH 70 % and ANI 95-96 %) for prokaryotic species delineation. On the basis of these results, strains SG22T, SG63T and SG29T represent three novel species within the genus Anaeromyxobacter, for which the names Anaeromyxobacter terrae sp. nov., Anaeromyxobacter oryzisoli sp. nov. and Anaeromyxobacter soli sp. nov., are proposed. The type strains are SG22T (= GDMCC 1.3185T = JCM 35581T), SG63T (= GDMCC 1.2914T = JCM 35124T) and SG29T (= GDMCC 1.2911T = JCM 35123T).


Asunto(s)
Myxococcales , Bacterias Fijadoras de Nitrógeno , Compuestos Férricos , Filogenia , ARN Ribosómico 16S/genética , Composición de Base , Ácidos Grasos/química , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Nucleótidos , Suelo
4.
Luminescence ; 39(1): e4615, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37957886

RESUMEN

By using the method of low-temperature crystallization, CsPbBr3 perovskite nanocrystals (PNCs) coated with trifluoroacetyl lysine (Tfa-Lys) and oleamine (Olam) were synthesized in aqueous solution. The structure of the CsPbBr3 PNCs was characterized by many methods, such as ultraviolet (UV)-visible absorption spectrophotometer, fluorescence spectrophotometer, transmission electron microscopy (TEM), and X-ray diffraction (XRD) pattern. The fluorescence emission of the CsPbBr3 PNCs is stable in water for about 1 day at room temperature. It was also found that the fluorescence of the PNCs could be obviously and selectively quenched after the addition of mercury ion (Hg2+ ), allowing a visual detection of Hg2+ by the naked eye under UV light illumination. The fluorescence quenching rate (I0 /I) has a good linear relationship with the addition of Hg2+ in the concentration range 0.075 to 1.5 mg/L, with a correlation coefficient (R2 ) of 0.997, and limit of detection of 0.046 mg/L. The fluorescence quenching mechanism of the PNCs was determined by the fluorescence lifetime and X-ray photoelectron spectroscopy (XPS) of the PNCs. Overall, the synthesis method for CsPbBr3 PNCs is simple and rapid, and the as-prepared PNCs are stable in water that could be conveniently used for selective detection of Hg2+ in the water environment.


Asunto(s)
Compuestos de Calcio , Mercurio , Nanopartículas , Titanio , Agua/química , Óxidos/química , Nanopartículas/química
5.
Int J Clin Pract ; 2023: 6638089, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37588100

RESUMEN

In this study, we conducted a meta-analysis to assess the efficacy and safety of teprotumumab in treating thyroid eye disease. We searched the Cochrane Library, PubMed, and Embase databases from inception to May 25, 2022, and included all randomized controlled trials. Odds ratios (ORs) were calculated using fixed- or random-effect models. A total of three studies involving 341 patients were identified. Overall, the analysis revealed that teprotumumab demonstrated superior integrated proptosis response compared to placebo in both the intention-to-treat (ITT) population (OR = 17.81, 95% CI = [10.32, 30.76], I2 = 50%) and per-protocol population (OR = 24.53, 95% CI = [12.96, 46.45], I2 = 14%). Furthermore, patients receiving teprotumumab showed significant improvement in overall response (OR = 8.35, 95% CI = [4.74, 14.71], I2 = 79%), diplopia response (OR = 5.53, 95% CI = [3.24, 9.44], I2 = 0%), and achieving a clinical activity score (CAS) of 0 or 1 (OR = 6.26, 95% CI = [3.87, 10.12], I2 = 0%). Moreover, patients treated with teprotumumab experienced greater improvements in proptosis (MD = -2.49, 95% CI = [-2.54, -2.45], I2 = 98%) and Graves' ophthalmopathy-specific quality of life (GO-QOL, MD = 11.48, 95% CI = [11.03, 11.93], I2 = 95%). However, it is important to note that patients receiving teprotumumab had a higher risk of adverse events, including serious adverse events, gastrointestinal adverse reactions, and muscle spasms. In summary, teprotumumab demonstrated greater improvement in proptosis response, proptosis, diplopia response, overall response, GO-QOL, and CAS. Nonetheless, it should be considered that its use is associated with a higher risk of adverse events.


Asunto(s)
Exoftalmia , Oftalmopatía de Graves , Humanos , Oftalmopatía de Graves/tratamiento farmacológico , Calidad de Vida , Diplopía , Ensayos Clínicos Controlados Aleatorios como Asunto
6.
Inorg Chem ; 61(43): 17185-17195, 2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-36263654

RESUMEN

The establishment of a reliable and sensitive method for the detection of flavonoids, such as kaempferol (Kae) and quercetin (Que), is important and challenging in food chemistry and pharmacology because numerous structural analogues may interfere with the detection. Until now, designing an efficient switch-on fluorescence sensing strategy for Kae and Que was still in the unachievable stage. In this work, a switch-on near-infrared (NIR) luminescence sensing assay for Kae and Que was fabricated based on a metal-organic framework (MOF) called IQBA-Yb for the first time. The fluorescence enhancing mechanism was that analytes served as additional "antenna" of Yb3+, leading to the efficient switch-on NIR emission under excitation at 467 nm. Meanwhile, the combination results of experiment and theoretical calculation revealed that there existed hydrogen bonds between Kae, Que, and the MOF skeleton, further promoting the energy transfer between the analyte and Yb3+ and facilitating fluorescence enhancement response. The developed probe possessed excellent sensing capability for Kae and Que, accompanied by a wide linear range (0.04-70, 0.06-90 µM), low detection limit (0.01, 0.06 µM), and short response time (20 min, 6 min), which was used to determine the Kae and Que contents in Green Lake and eatable Que samples with satisfactory results.


Asunto(s)
Estructuras Metalorgánicas , Quercetina , Quercetina/química , Quempferoles/química , Luminiscencia , Flavonoides/química
7.
Inorg Chem ; 60(24): 18870-18878, 2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34855375

RESUMEN

Photochromic materials are constructed with molecules accompanied by structural change after triggering by light, which are of great importance and necessity for various applications. However, because of space-confinement effects, molecule stacking of these photoresponsive chromophores within coordination polymers (CPs) always results in an efficiency decrement and a response delay, and this phenomenon will lead to a poor photochromic property. Herein, a CP (named CIT-E) with a 3-fold-interpenetrating network structure, which was prepared with (Z)-1,2-diphenyl-1,2-bis[4-(pyridin-3-ylmethoxy)phenyl]ethene (1Z) and a CuI cluster, showed fast reversible photochromic behavior. Under UV-light illumination, the color of CIT-Z changed from pale yellow to reddish brown. With the illumination of green light, the polymer could return to its initial color within 10 s. To reveal the mechanism of reversible photochromic behavior of CIT-Z, single-crystal structures of each color state were fully studied, and other scientific study methods were also used, such as time-dependent density functional theory calculation and control experiments. It was found that, with light illumination, this behavior of CIT-Z was the result of a ligand-to-metal charge-transfer process, and this process was triggered by subtle molecular conformation variation of tetraphenylethylene. It should be noted that CIT-Z has high thermal and chemical stability, which are excellent advantages as smart photoresponsive materials. As a proof of concept, a uniform thin film with such a fascinating photochromic property allows applications in invisible anticounterfeiting and dynamic optical data storage. Overall, the present study opens up a new avenue toward reversible photochromic materials.

8.
BMC Ophthalmol ; 21(1): 61, 2021 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-33499815

RESUMEN

BACKGROUND: This study analyzed the clinical features, imaging manifestations, histopathology, immunohistochemistry, and surgical approaches of the orbital solitary fibrous tumor (OSFT), as well as the factors for postoperative recurrence of such disease. METHODS: The clinical data of 16 patients with OSFT treated in our center from 2003 to 2020 were analyzed retrospectively, and the clinical symptoms, treatment methods, and follow-up results were recorded. RESULTS: Of the 16 patients, 8 were females (50.0 %) and 8 were males (50.0 %); the average age of treatment was 37 ± 7 years and the median follow-up time was 74 (8, 228) months. Sixteen patients with OSFT underwent a total of 29 operations, of which 12 were transorbital approach operations and 17 were transfronto-orbital approach operations. Ten patients (10/16, 62.5 %) had recurrence. The recurrence rate of transorbital approach operations was 83.3 % (10/12), and the recurrence rate of transfronto-orbital approach operations was 17.6 % (3/17). No patients had treatment-related complications. CONCLUSIONS: The main pathological feature of OSFT is a benign tumor. OSFT has a tendency to grow toward the cranio-orbital junction. The postoperative recurrence rate of OSFT is relatively high, so complete tumor resection is very important for prognosis. Inappropriate surgical approaches can lead to incomplete removal of the tumor and cause recurrence. Choosing the correct operation approach according to the position of the OSFT in the orbit and complete removal of the dura mater and bone affected by the tumor is crucial for the prognosis. Nevertheless, regular long-term follow-up after complete resection is necessary.


Asunto(s)
Neoplasias Orbitales , Tumores Fibrosos Solitarios , Adulto , China/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Recurrencia Local de Neoplasia/epidemiología , Neoplasias Orbitales/cirugía , Estudios Retrospectivos , Tumores Fibrosos Solitarios/cirugía , Centros de Atención Terciaria
9.
Chemistry ; 26(13): 2766-2779, 2020 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-31697441

RESUMEN

Porous coordination polymers or metal-organic frameworks with reversible phase-transition behavior possess some attractive properties, and can respond to external stimuli, including physical and chemical stimuli, in a dynamic fashion. Their phase transitions can be triggered by adsorption/desorption of guest molecules, temperature changes, high pressure, light irradiation, and electric fields; these mainly include two types of transitions: crystal-amorphous and crystal-crystal transitions. These types of porous coordination polymers have received much attention because of their interesting properties and potential applications. Herein, reversible phase transition porous coordination polymers are summarized and classified based on different stimuli sources. Corresponding typical examples are then introduced. Finally, examples of their applications in gas separation, chemical sensors, guest molecule encapsulation, and energy storage are also presented.

10.
Inorg Chem ; 59(9): 6508-6517, 2020 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-32315165

RESUMEN

A series of silver coordination complexes (CCs) have been synthesized through self-assembly of five pyridine-substituted tetraphenylethylene stereoisomer ligands with silver ions (named Ag-TPE-2by-1-E, Ag-TPE-2by-2-E, Ag-TPE-2by-2-Z, Ag-TPE-2by-3-E, and Ag-TPE-2by-3-Z). These silver CCs show distinct topologies including beaded chain frameworks, linear structures, and discrete metallacycles. The single-crystal analysis results reveal the critical role of the space distribution of the coordination site and stereoisomer ligands in controlling the silver CCs' geometry configuration and modulating the optical properties. Luminescent investigations revealed that Ag-TPE-2by-2-E, Ag-TPE-2by-2-Z, Ag-TPE-2by-3-E, and Ag-TPE-2by-3-Z possess obvious mechanocharomic behaviors, which can be achieved several reversible cycles through repeated grinding and methanol soaking processes. However, the Ag-TPE-2by-1-E showed tenacious stability toward mechanical grinding and temperature. Thus, these silver CCs provide a good platform to investigate the influence of the space distribution of the coordination site of ligands on their geometry and mechanocharomic properties.

11.
Luminescence ; 35(5): 702-708, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31926119

RESUMEN

Recognition and quantification of oligonucleotide sequences play important roles in medical diagnosis. In this study, a new fluorescent oligonucleotide-stabilized silver nanocluster beacon (NCB) probe was designed for sensitive detection of oligonucleotide sequence targets. This probe contained two tailored DNA strands. One strand was a signal probe strand containing a cytosine-rich strand template for fluorescent silver nanocluster (Ag NC) synthesis and a detection sections at each end. The other strand was a fluorescence enhancing strand containing a guanine-rich section for signal enhancement at one end and a linker section complementary to one end of the signal probe strand. After synthesis of the Ag NCs and hybridization of the two strands, the fluorescence intensity of the as-prepared silver NCB was enhanced 200-fold compared with the Ag NCs. Two NCBs were designed to detect two disease-related oligonucleotide sequences, and results indicated that the two target oligonucleotide sequences in the range 50.0-600.0 and 50.0-200.0 nM could be linearly detected with detection limits of 20 and 25 nM, respectively. The developed fluorescence method using NCBs for oligonucleotide sequence detection was sensitive, facile and had potential for use in bioanalysis and diagnosis.


Asunto(s)
Técnicas Biosensibles , ADN/análisis , Fluorescencia , Colorantes Fluorescentes/química , Nanopartículas del Metal/química , Sondas de Oligonucleótidos/química , Plata/química , ADN/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Espectrometría de Fluorescencia
12.
Mikrochim Acta ; 187(2): 106, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31916054

RESUMEN

A hydrothermal method was applied to the synthesis of green-emitting gold nanoclusters (Au NCs) which are shown to be viable fluorescent probes for 4-nitrophenol (4-NP). The Au NCs were prepared by using thiol-ß-cyclodextrin as a template. Under 365 nm excitation, their green fluorescence has a peak at 502 nm, with a narrow emission bandwidth of only 30 nm. The fluorescence and composition of the Au NCs were characterized and the mechanism of the nanocluster formation is discussed. Due to host-guest recognition of ß-cyclodextrin and 4-NP, fluorescence is quenched. The probe can selectively recognize 4-NP among other nitrophenols. A fluorometric and colorimetric assay was developed for 4-NP that works in the 0.1 to 100 µM concentration range and has a detection limit of 90 nM (at 3σ). Graphical abstractSchematic representation of hydrothermal synthesis of green-emitting gold nanoclusters using thiol-ß-cyclodextrin. Fluorescence is quenched and the absorption of the nanoclusters is increases in the presence of 4-nitrophenol.

13.
Chemistry ; 25(22): 5787-5792, 2019 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-30786080

RESUMEN

Over the last decade, the controllable reversible phase transition of functional materials has received growing interest as it shows unique suitability for various technological applications. Although many metal-organic frameworks (MOFs) possess a lamellar structure, the reversible structural transformation of MOFs between their three-dimensional (3D) phase and two-dimensional (2D) phase remains a largely unexplored area. Herein, we report for the first time a europium MOF with unprecedented reversible morphology in different solvents at room temperature. This europium MOF displayed a 3D nanorod morphology in organic solvent and a 2D nanobelt architecture in water. As a proof of concept for potential applications of this reversible-phase-transition MOF, we were able to use a delamination recovery method to load dye molecules that previously could not be loaded into europium MOFs.

14.
Inorg Chem ; 58(17): 11793-11800, 2019 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-31430123

RESUMEN

A series of silver coordination polymers (CPs) have been synthesized through self-assembly of three pyridinecarboxylic acid hydrazide (p-, m-, o-position) ligands with silver clusters (named Ag1-iah, Ag2-iah, and Ag3-iah). These silver CPs show different one- and two-dimensional topologies including cross-helical chains, planar network, and parallel helical chains for Ag1-iah, Ag2-iah, and Ag3-iah, respectively. The combination of experimental and computational results reveals the critical role in the space distribution of the coordination site of silver clusters and ligands in controlling the silver CPs' dimensionality and packing arrangement and modulating the optical properties and stability. Luminescent investigations reveal that Ag3-iah can selectively detect dichloromethane or trichloromethane in tetrachloromethane. These silver CPs provide a good model to study the influence of the space distribution of the coordination site of ligands on their packing arrangement and properties.

15.
Arch Virol ; 164(5): 1335-1341, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30848390

RESUMEN

In infants, hepatitis B virus (HBV) infections are mainly acquired by mother-to-child transmission (MTCT). Current tests for the presence of HBV markers at birth can neither confirm nor exclude MTCT. The aim of this study was to find an early diagnostic marker of HBV MTCT. From 2011 to 2016, we studied a total of 5999 pregnant women who gave birth at our hospital in Shenzhen City, China. HBsAg-positive mothers and their offspring (n=386 pairs) were tested at birth for HBV markers, and 207 infants were followed up at 7-12 months after birth. The HBsAg-seropositive rate of the pregnant women was 12.5%. Additionally, 28.0%, 36.0%, 98.5% and 6.6% of umbilical cord (UC) blood samples of neonates were found to be positive for HBsAg, HBeAg, anti-HBc and HBV-DNA, respectively, whereas for neonatal femoral venous (FV) blood, the percentages were 16.2%, 38.0%, 98.8% and 2.6%, respectively. Mothers with high HBV DNA loads and those who were HBeAg positive were the most likely to have HBV-positive offspring. Immunoprophylaxis failed in five infants: the difference in median HBV DNA titer between UC blood from infants with and without HBV MTCT was statistically significant, and there was no significant difference in HBV DNA titer between UC blood and in peripheral blood of infants with HBV MTCT. In conclusion, we found that HBeAg positivity and high HBV loads are strong risk factors for MTCT of HBV and that the HBV DNA titer in the UC is a good predictor for HBV MTCT.


Asunto(s)
Anticuerpos Antivirales/sangre , Anticuerpos contra la Hepatitis B/sangre , Antígenos e de la Hepatitis B/sangre , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B/diagnóstico , Biomarcadores , ADN Viral/sangre , Diagnóstico Precoz , Femenino , Hepatitis B/epidemiología , Hepatitis B/transmisión , Antígenos del Núcleo de la Hepatitis B/inmunología , Antígenos de Superficie de la Hepatitis B/sangre , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/inmunología , Humanos , Lactante , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Embarazo , Complicaciones Infecciosas del Embarazo , Carga Viral
16.
Molecules ; 24(3)2019 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-30682770

RESUMEN

Porous organic cages (POCs) have attracted extensive attention due to their unique structures and tremendous application potential in numerous areas. In this study, an enantioselective potentiometric sensor composed of a polyvinyl chloride (PVC) membrane electrode modified with CC3-R POC material was used for the recognition of enantiomers of 2-amino-1-butanol. After optimisation, the developed sensor exhibited enantioselectivity toward S-2-amino-1-butanol ( log K S , R P o t = -0.98) with acceptable sensitivity, and a near-Nernstian response of 25.8 ± 0.3 mV/decade within a pH range of 6.0⁻9.0.


Asunto(s)
Amino Alcoholes/química , Técnicas Electroquímicas , Electrodos , Concentración de Iones de Hidrógeno , Membranas Artificiales , Estructura Molecular , Cloruro de Polivinilo/química , Porosidad , Potenciometría , Sensibilidad y Especificidad , Estereoisomerismo
17.
Artículo en Inglés | MEDLINE | ID: mdl-29507071

RESUMEN

The occurrence of heavy metal resistance genes in multiresistant Enterobacteriaceae possessing blaNDM-1 or blaCTX-M-15 genes was examined by PCR and pulsed-field gel electrophoresis with S1 nuclease. Compared with clinical susceptible isolates (10.0% to 30.0%), the pcoA, merA, silC, and arsA genes occurred with higher frequencies in blaNDM-1-positive (48.8% to 71.8%) and blaCTX-M-15-positive (19.4% to 52.8%) isolates, and they were mostly located on plasmids. Given the high association of metal resistance genes with multidrug-resistant Enterobacteriaceae, increased vigilance needs to be taken with the use of heavy metals in hospitals and the environment.


Asunto(s)
Antibacterianos/farmacología , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Metales Pesados/farmacología , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
18.
Luminescence ; 33(1): 168-173, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28960783

RESUMEN

In this paper, we synthesized a papain-stabilized fluorescent Au nanocluster (NC) probe and studied its interaction with dopamine. As fluorescence of papain-Au NCs is quenched in the presence of dopamine under alkaline conditions, we were able to establish a simple, selective analytical method for dopamine determination. By studying the fluorescence lifetime and dynamic light scattering of the NCs before and after interaction with dopamine, we found that this fluorescence quenching mechanism was possibly due to dopamine self-polymerization that produced polydopamine that cross-linked papain-Au NCs. Based on this new phenomenon, we proposed a highly selective analytical method for dopamine detection. Other small organic molecules, such as amino acids, ascorbic acid and uric acid did not interfere with dopamine detection. Dopamine in the range 20-100 µM can be linearly detected by the fluorescence quenching ratio of gold nanoclusters. Dopamine detection could be visually realized by watching color changes of papain-Au NCs under UV light or daylight, as both fluorescence and absorption of the papain-Au NCs changed during dopamine polymerization.


Asunto(s)
Dopamina/síntesis química , Fluorescencia , Colorantes Fluorescentes/química , Oro/química , Nanoestructuras/química , Papaína/química , Dopamina/química , Modelos Moleculares , Polimerizacion , Espectrometría de Fluorescencia
19.
Artículo en Zh | MEDLINE | ID: mdl-28511300

RESUMEN

Objective: To investigate the fatigue status of military personnel stationed in plateau and high cold region, and to analyze the mediator effect of trait coping style on job stress and fatigue. Methods: In October 2010, with the method of cluster random sampling survey, 531 military personnel stationed in plateau and high cold region were chosen as subject. The fatigue status were evaluated by the Chinese version multidimensional fatigue inventory (MFI-20) , job stress were evaluated by the Job Stress Survey (JSS) , and trait coping style were evaluated by the Trait Coping Style Questionnaire (TCSQ) . Results: According to the information of different population characteristics, mean rank of physical fatigue about the urban (town) group were higher than that of rural group (Z=-2.200, P<0.05) ; mean rank of reduced motivation about the urban (town) group were higher than that of rural group (Z=-2.781, P<0.05) ; mean rank of general fatigue scores about the urban (town) group were higher than that of rural group (Z=-3.026, P<0.05) ; mean rank of physical fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-4.045, P<0.05) ; mean rank of reduced motivation about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.182, P<0.05) ; mean rank of mental fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.879, P<0.05) ; mean rank of general fatigue scores about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-3.647, P<0.05) ; mean rank of reduced motivation were significant statistical difference among the military officers, sergeancy and soldier group (F=18.965, P<0.05) ; mean rank of general fatigue scores were significant statistical difference among the military officers, sergeancy and soldier group (F=14.711, P<0.05) . The score of negative coping style were positively correlated with the score of physical fatigue (r(s)=0.129) , reduced activity (r(s)=0.123) , reduced motivation (r(s)=0.149) and general fatigue (r(s)=0.174) respectively, the score of organizational support lack strength were positively correlated with the score of physical fatigue (r(s)=0.090) , reduced activity (r(s)=0.098) , reduced motivation (r(s)=0.099) and general fatigue (r(s)=0.130) respectively. The mediator effect of negative coping style on the job stress and fatigue was 0.013 (P<0.01) . Conclusion: The fatigue statuses of the urban (town) group and the up or equal 20-years old age group are poor, and the negative coping style plays mediator effect on the job stress and fatigue.


Asunto(s)
Adaptación Psicológica , Fatiga , Personal Militar/psicología , Estrés Laboral/psicología , Estrés Psicológico , Adulto , Humanos , Encuestas y Cuestionarios , Temperatura , Adulto Joven
20.
Antimicrob Agents Chemother ; 60(7): 4336-8, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27067314

RESUMEN

We sequenced a novel conjugative multidrug resistance IncF plasmid, p42-2, isolated from Escherichia coli strain 42-2, previously identified in China. p42-2 is 106,886 bp long, composed of a typical IncFII-type backbone (∼54 kb) and one distinct acquired DNA region spanning ∼53 kb, harboring 12 antibiotic resistance genes [blaCTX-M-55, oqxA, oqxB, fosA3, floR, tetA(A), tetA(R), strA, strB, sul2, aph(3')-II, and ΔblaTEM-1]. The spread of these multidrug resistance determinants on the same plasmid is of great concern and, because of coresistance to antibiotics from different classes, is therapeutically challenging.


Asunto(s)
Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , beta-Lactamasas/metabolismo , China , Farmacorresistencia Bacteriana Múltiple/genética , Plásmidos/genética , beta-Lactamasas/genética
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