Communication-Ultrafast Anodized Titania Nanotube Arrays Loaded with Quantum Dots via Ultrasonic Assistance

Self-aligned and firmly-structured titania nanotube arrays (TNAs) with excellent photoelectric response were fabricated by anodization in tens of seconds. Furthermore, TNAs were decorated with CdS quantum dots by ultrasonic-assisted successive ionic layer adsorption and reaction (U-SILAR) method. The resulted CdS/TNAs hybrid shows higher visible light absorption, stronger photo current and stable structure than those of the sample by traditional SILAR method. © 2016 The Electrochemical Society. [DOI: 10.1149/2.0341609jss] All rights reserved. Great efforts have been made to produce titania nanotube arrays (TNAs) by electrochemical anodization method due to its unique advantages. 1-3 Normally, one or more hours are needed to grow TNAs with a length of several micrometers. Quantum dots (QDs) can be easily synthesized and attached on TNAs by successive ionic layer adsorption and reaction (SILAR) method. 9,10 However, the disadvantages of the method are obvious, e.g. the uncontrollable uniformity and dispersion of QDs and the weak adhesion of the QDs on TNAs, etc. In this work, a new approach using ultrasonic-assisted SILAR (U-SILAR) is developed to improve the QDs/TNAs hybrid structures. We found that the QDs could be well distributed throughout the tubes and firmly adhered on TNAs. The transient photoelectric response was investigated. Experimental Titanium foils (0.1 mm in thickness, 99.6% purity) were anodized by an electrochemical setup which consists of Interlock potentiostatgalvanostat (IPD-12003SLU) and a classical two-electrode cell. The electrolyte contains 0.4 M NH 4 F dissolved in a solution of ethylene glycol and DI water (30:1 volume ratio). The anodization was performed at 120 V without stir at 10 • C for 4, 20, 40, 60, and 80s, respectively. The samples were named as TNA120 series. As a reference, another series of samples were prepared at 60 V in the electrolyte which contains 0.27 M NH 4 F dissolved in previous solution at 10 • C for 170, 640 s and 3 h, respectively. These control samples were referred to as TNAs60 series. All samples were post annealed in air at 450 • C for 2 h with a heating speed of 5 • C · min −1 . The annealed TNAs120 (80 s) samples were sequentially dipped in two different solutions for 3 min in each one. One is 0.1 M Cd(NO 3 ) 2 ethanol solution, and the other is 0.1 M Na 2 S methanol solution. The solution containers were put in a 300 W ultrasonic machine during dipping processes. The process was referred to as U-SILAR method. As to the traditional SILAR process, the TNAs120 (80 s) samples were sequentially dipped in the previous solutions without ultrasonic vibration for 5 min. A scanning electron microscope (SEM) Hitachi FE-SEM S4800 was employed for characterizing the morphology of the samples, and the compositional analysis was performed by energy dispersive X-ray spectrometer (EDS) attached to the SEM. The diffuse reflection abz E-mail: [email protected] sorption spectra (DRS) were measured by UV-Vis spectrophotometer (ShimadzuUV-265). The photoelectric response of the samples was recorded with an electrochemical workstation (CHI660E). A white light source was utilized as an excitation source (intensity: 150 mW cm −2 ). Results and Discussion −2 ) and the durations of the first two stages are longer than those of TNAs120. Then the current shows a quasi-steady trend in later time. Different current variations mean different growth processes and morphologies of the resulted samples. As shown by the insets i

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health

Morphology and Microstructure of As-Synthesized Anodic TiO₂ Nanotube Arrays

Abstract The as-grown structure of electrochemically synthesized titania nanotube arrays is investigated by scanning electron microscope (SEM) in combination with transmission electron microscope (TEM) as well as X-ray diffraction (XRD). The analysis reveals a preferred growth direction of the nanotubes relative to the substrate surface and the well control on the nanotube arrays morphology. The crystal structure of the anatase phase is detected and exists in the tube walls without any thermal treatment, which makes it possible to realize the application of as-formed TiO2 nanotubes avoiding the degradation of the nanotube structures when sintering. In addition, a new growth, layered model of the anodic TiO2 nanotubes is presented to obtain further understanding of the growth mechanism.</p

Structure and photoluminescence study of silicon based two-dimensional Si2Te3 nanostructures

As an emerging silicon-based two-dimensional (2D) material, vertical and horizontal Si2Te3 nanoplates on various substrates have been deposited by chemical vapor deposition. Structure, composition, and optical properties of these nanostructures are investigated by electron microscopy, x-ray photoelectron emission, energy dispersive x-ray spectroscopy, and temperature dependent photoluminescence. Band gap emissions of Si2Te3 nanoplates containing four noticeable emission peaks, i.e., free exciton, acceptor-bound exciton (A0X), and phonon replicas of A0X, are observed at temperatures below 90 K. The temperature dependent emission intensity of A0X indicates there are two quenching channels, which are associated with thermal quenching and thermal dissociations of A0X to free excitons. Two defect emissions are observed at measurement temperatures from 10 to 300 K, and their peak energies decrease by following the band gap change at low temperature range but increase at high temperature range as the temperature is increased. This abnormal temperature dependent behavior is explained by a combination of band gap shrinkage and thermally induced localization effects of defects at high temperature. This study helps to understand the electronic and optical properties of the unique 2D Si2Te3 nanostructures for potential applications

The Dose-Dependent Effect of Nesiritide on Renal Function in Patients with Acute Decompensated Heart Failure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

<div><p>Background</p><p>Conflicting renal effects of nesiritide have been reported in patients with acute decompensated heart failure. To answer this controversy, we performed a meta-analysis of randomized controlled trials to evaluate the influence of nesiritide on renal function in patients with acute decompensated heart failure.</p><p>Methods</p><p>Articles were obtained from PubMed, Medline, Cochrane Library and reference review. Randomized controlled studies that investigated the effects of continuous infusion of nesiritide on renal function in adult patients with acute decompensated heart failure were included and analyzed. Fixed-effect model was used to estimate relative risk (RR) and weight mean difference (WMD). The quality assessment of each study, subgroup, sensitivity, and publication bias analyses were performed.</p><p>Results</p><p>Fifteen randomized controlled trials were eligible for inclusion. Most of included studies had relatively high quality and no publication bias was found. Overall, compared to control therapies, nesiritide might increase the risk of worsening renal function in patients with acute decompensated heart failure (RR 1.08, 95% CI 1.01–1.15, <i>P</i> = 0.023). In subgroup analysis, high-dose nesiritide strongly associated with renal dysfunction (RR 1.54, 95% CI 1.19-2.00, <i>P</i> = 0.001), but no statistical differences were observed in standard-dose (RR 1.04, 95% CI 0.98-1.12, <i>P</i> = 0.213), low-dose groups (RR 1.01, 95% CI 0.74-1.37, <i>P</i> = 0.968) and same results were identified in the subgroup analysis of placebo controlled trials. Peak mean change of serum creatinine from baseline was no significant difference (WMD -2.54, 95% CI -5.76-0.67, <i>P</i> = 0.121).</p><p>Conclusions</p><p>In our meta-analysis, nesiritide may have a dose-dependent effect on renal function in patients with acute decompensated heart failure. High-dose nesiritide is likely to increase the risk of worsening renal function, but standard-dose and low-dose nesiritide probably have no impact on renal function. These findings could be helpful to optimize the use of nesiritide in clinical practice.</p></div

Modulation of the Tomato Rhizosphere Microbiome via Changes in Root Exudation Mediated by the Ethylene Receptor NR

Plant hormones have been recently shown to exert an indirect influence on the recruitment of plant-associated microbiomes. However, it remains unclear the extent to which the disruption of the ethylene (ET) signaling pathway affects the assembly and functioning of plant-root microbiomes. In this study, the Never-ripe tomato mutant (Nr) was profiled for differences compared to the wild type (control). Tomato plants were subjected to root exudate profiling and the characterization of bacterial and fungal communities. Compared to the control, Nr revealed differences in the composition of root exudates, including lower amounts of esculetin, gallic acid, L-fucose, eicosapentaenoic acid, and higher amounts of &beta;-aldehyde. Interestingly, Nr significantly differed in the composition and functioning of the rhizosphere bacterial community. We also identified the taxa that occurred at relatively higher abundances in Nr, including the genus Lysobacter, which displayed a significant negative correlation with changes in eicosapentaenoic acid and esculetin, and a significant positive correlation with changes in &beta;-aldehyde. Taken together, our study provides evidence that a mutation in the ET receptor exerts predictable changes in the root-associated microbial taxa of tomato plants. These indirect effects can potentially be explored towards new strategies to engineer beneficial plant microbiomes via targeted changes in plant genetics and physiology

Characteristics of the included studies.

<p>Abbreviations: NA, Not available; GFR, Glomerular filtration rate; RCT, Randomized controlled trial; SCr, Serum creatinine SD, Standard deviation; WRF, Worsening renal function</p><p>Characteristics of the included studies.</p

Forest plot depicting the effect of different doses of nesiritide on the risk of WRF in patients with ADHF.

<p>Forest plot depicting the effect of different doses of nesiritide on the risk of WRF in patients with ADHF.</p

Forest plot depicting the overall effect of nesiritide on the risk of WRF in patients with ADHF.

<p>Forest plot depicting the overall effect of nesiritide on the risk of WRF in patients with ADHF.</p