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Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm-2 with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.
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OBJECTIVE: The effect of using standardized parent training history-taking on the quality of medical records and communication skills among pediatric interns was determined. METHODS: Fifth-year interns who were undertaking a pediatric clinical practice rotation were randomized to intervention and control groups. All of the pediatric interns received history-taking training by lecture and bedside teaching. The pediatric interns in the intervention group also received standardized parent history-taking training. The following two outcome measures were used: the scores of medical records, which were written by the pediatric interns after history-taking from real parents of pediatric patients; and the communication assessment tool (CAT) assessed by real parents. RESULTS: The general information, history of present illness (HPI), past medical history, personal history, family history, diagnosis, diagnostic analysis, and differential diagnosis scores in the intervention group were significantly higher than the control group (p < 0.05). Assessment of the CAT indicated that the real parents were more satisfied with the pediatric interns in the intervention group. CONCLUSIONS: Standardized parent training history-taking is effective in improving the quality of medical records by pediatric interns. Standardized parent training history-taking is a superior teaching tool for clinical reasoning ability, as well as communication skills in clinical pediatric practice.
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Comunicación , Anamnesis/normas , Registros Médicos/normas , Padres/educación , Pediatría , Competencia Profesional , Estudiantes de Medicina , China , Femenino , Humanos , Internado y Residencia , Masculino , Garantía de la Calidad de Atención de SaludRESUMEN
The stability of large ligated copper(I) clusters of undeca- and dodecanuclearity encapsulating iodide and stabilized by dithio- and diseleno-phosph(in)ates was investigated by density functional theory (DFT) calculations. A bonding analysis is provided, which shows strong iono-covalent bonding between the iodide and its host. The electronic structures of the title compounds suggest the possibility for interesting photoluminescent properties, which were fully investigated by time-dependent DFT calculations including vibronic contributions to simulate the phosphorescence spectra. The quantum mechanical results were compared to the experimental data obtained for the new clusters [Cu11(µ9-I)(µ3-I)3{Se2P(OiPr)2}6]+ and [Cu11(µ9-I)(µ3-I)3(Se2PPh2)6]+, whose syntheses, X-ray structures, and full characterizations are reported in this paper. From this combined theoretical/experimental investigation, it is suggested that the encapsulation by the same copper(I) cages of a formally Cu- anion is also possible. DFT calculations on these species are consistent with the existence of stable two-electron superatoms.
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We report on a Ag5 coordination polymer and discrete Ag8 and Ag10 dithiophosphate clusters. The cluster formation and structures were affected by the stoichiometric control of the M : L molar ratios used. The cluster [Ag5{S2P(O(i)Pr)2}4]n(PF6)n, , is a monomeric unit within a coordination polymer formed through the reaction between [Ag(CH3CN)4]PF6 and the dithiophosphate ligand, [S2P(O(i)Pr)2](-), used in a M : L molar ratio of 5 : 4. All other clusters formed in the study are discrete units with encapsulated anions within the metal framework. The clusters [Ag8(X){S2P(O(i)Pr)2}6](PF6) (X = F, , Cl, , Br, ) are all cationic and contain monoanionic halogens. The related cluster [Ag8(H/D){S2P(O(i)Pr)2}6](PF6) contains either a hydride or a deuteride ion, and , respectively. The cluster [Ag8(S){S2P(O(i)Pr)2}6], , is neutral due to the di-anionic nature of the encapsulated sulfide anion. Clusters were all formed by reacting [Ag(CH3CN)4]PF6 and [S2P(O(i)Pr)2](-) in a M : L molar ratio of 8 : 6 and stirring for 1 h in THF; thereafter the respective anions (one equiv.) were added in situ. The cluster [Ag10(I)4{S2P(O(i)Pr)2}6], , is also neutral due to the charge balancing of the additional metal and halogen. In this case the M : L : X molar ratio was 10 : 6 : 4. All new clusters were characterized by (1)H and (31)P NMR, and elemental analysis, and , , were characterized by single crystal X-ray diffraction.
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Complejos de Coordinación/química , Fosfatos/química , Polímeros/química , Plata/química , Cristalografía por Rayos X , Espectroscopía de Resonancia MagnéticaRESUMEN
Compound 1, [Cu11(µ9-Br)(µ3-Br)3{S2P(O(i)Pr)2}6](+), containing the first µ9-bromide at the center of a pentacapped trigonal-prismatic copper skeleton, was isolated from the reaction of [Cu(CH3CN)4](PF6), NH4[S2P(O(i)Pr)2], and Bu4NBr in 11:6:4 ratios in methanol. Treatment of 1 with Bu4NI resulted in a complete replacement of four bromides to yield a corresponding iodo analogue {Cu11(I)(I)3[S2P(O(i)Pr)2]6}(+), 2. The central bromide and iodide in 1 and 2 can be replaced by a sulfide generated in situ from Na2S2O3 to produce [Cu11(µ9-S)(µ3-X)3{S2P(O(i)Pr)2}6] (X = Br, 3; I, 4). All four compounds displayed interesting photoluminescent properties.
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Two luminescent, undecanuclear silver complexes [Ag(11)(µ(9)-I)(µ(3)-I)(3){E(2)P(O(i)Pr)(2)}(6)](PF(6)) [E = S (yellow), 1; Se (orange), 2], containing the first µ(9)-iodine inscribed at the center of a pentacapped trigonal-prismatic silver skeleton, were reported.
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A selective enrichment broth (SVV) was formulated to allow concurrent growth of Salmonella spp., V. parahaemolyticus, and V. cholerae. Potassium tellurite and sodium citrate were added as the inhibitors, while glucose, mannitol, anhydrous sodium sulfite and sodium pyruvate were employed as the growth-promoters. When mixed in equal or varied proportions, the target pathogens in SVV had a great accumulation (10(5)-10(8) CFU/ml) and effectively inhibited the growth of competitive microflora. In the artificially contaminated samples, a high recovery of these 3 target pathogens was obtained in SVV. Finally, Salmonella spp., V. parahaemolyticus, and V. cholerae were detected from 608 suspicious food samples by SVV with real-time PCR, and no false-positive or -negative results were reported. In summary, SVV has been shown to be a suitable broth for the simultaneous detection of the 3 pathogens by multipathogen detection on a single-assay platform.
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Medios de Cultivo , Microbiología de Alimentos , Salmonella/crecimiento & desarrollo , Vibrio cholerae/crecimiento & desarrollo , Vibrio parahaemolyticus/crecimiento & desarrollo , Carbohidratos , Citratos , Reacción en Cadena de la Polimerasa , Salmonella/aislamiento & purificación , Citrato de Sodio , Telurio , Vibrio cholerae/aislamiento & purificación , Vibrio parahaemolyticus/aislamiento & purificaciónRESUMEN
Epidemics of acute hemorrhagic conjunctivitis are always explosive and extensive, and have been recognized as a serious international public health problem. Enterovirus 70 and coxsackievirus A24 variant have been identified as the major etiological agents in acute hemorrhagic conjunctivitis outbreaks worldwide. A novel multiplex real-time RT-PCR assay was developed for simultaneous detection, identification and quantitation of enterovirus 70 and coxsackievirus A24 variant. The specificity, sensitivity and reproducibility of the method were analyzed and 125 clinical samples were tested using this method. No cross-reactivity with other enteroviruses strains was detected. The detection limits achieved were 10 copies/tube of enterovirus 70 and 100 copies/tube of coxsackievirus A24 variant respectively, and the addition of the internal control does not compromise the sensitivity or specificity. One hundred and twenty five clinical samples were tested and the results were consistent with the results obtained by using virus isolation followed by neutralization and sequencing of VP1 region. Due to its high specificity, sensitivity and elimination of false negative results by the internal control, this assay is suitable for both research applications and rapid clinical diagnosis of enterovirus 70 and coxsackievirus A24 variant.