MOF-Based Photonic Crystal Film toward Separation of Organic Dyes.

Metal-organic framework (MOF)-directed photonic structure materials have inspired great attention for extended and enhanced functions. However, the direct construction of photonic crystals (PCs) with MOF particles as building blocks still remains a challenge. Herein, we designed and synthesized monodisperse polyamidoamine (PAMAM) dendrimer-modified zeolitic imidazolate framework (ZIF-8) particles (PAMAM@ZIF-8) via a postsynthetic method, rendering ZIF-8 with hydrophilicity. It was found that the PAMAM@ZIF-8 particles could directly assemble into a uniform photonic structure and effectively suppressed the coffee-ring effect, forming homogeneous PC films with different structural colors. A PC pattern with angle-dependent colors was also achieved, which might have potential applications in the field of anticounterfeiting printing. More importantly, by taking advantages of a membrane separation-assisted assembly process, a colorful and robust PC film was accomplished on the surface of reduced graphene oxide (rGO). The hierarchal PAMAM@ZIF-8/rGO film demonstrates a superior separation ability toward organic dye solutions, which enriches the function of PC materials. This work gives a new insight into the fabrication of MOF-based functional PC materials, which will extend the application of PCs in the high selective and effective separation field.

Gold-loaded microspheres via carbosilane-thioether dendrimers as stabilizers and their performance in layer-controllable photonic crystals.

Gold nanoparticle (Au NP) incorporated photonic crystals (PCs) have been extensively studied due to the intricate interplay between the surface plasmon resonance of Au NPs and the periodic nanostructure of PCs. Herein, we successfully synthesized Au NP decorated poly(styrene-co-(generation 3 carbosilane-thioether vinyl-terminated dendrimer)) (P(st-co-G3Vi)) microspheres via in situ reduction of Au ions based on the strong coordination between the Au ions and the sulfur atom in G3Vi dendrimers. These composite Au-doped microspheres demonstrate a bumpy surface topography, which gives rise to a higher hydrophobicity and could effectively suppress the formation of an ubiquitous coffee-ring during the drying process of a colloidal suspension. More importantly, layer-controllable PCs were constructed with Au-doped microspheres by combining the Langmuir-Blodgett method with a layer-by-layer stacking strategy. By manipulating the stacking layers and diameters of microspheres, multifarious PCs with different photonic band gaps and reflection intensities were obtained, which can serve as an effective substrate for amplified quantum dot fluorescence. Further investigation reveals that fluorescence could be significantly pronounced by five-layer PCs. This work offers a facile and reproducible strategy to prepare Au NP incorporated PCs by in situ synthesis of Au NPs within dendrimer-functionalized microspheres, resulting in an enhancement of quantum dot fluorescence, which will lead to promising applications in energy-saving optoelectronic devices.

One-Step Synthesis of FA-Directing FAPbBr3 Perovskite Nanocrystals toward High-Performance Display.

Hybrid organic-inorganic and all-inorganic metal halide perovskite nanocrystals (PNCs) have aroused extensive attention from both academic and industrial researchers, considering their excellent performance in optoelectronic applications. Herein, we develop a facile and time-saving strategy to synthesize NH2CH═NH2PbBr3 (NH2CH═NH+, FA) PNCs at room temperature. Benefiting from this facile method, high-quality FAPbBr3 PNCs with photoluminescence quantum yield up to 76% and narrow full width at half-maxima of 20 nm can be produced on a large scale. Moreover, anion-exchange reactions run by using FAPbBr3 as a template, producing various PNCs with different anion constituents. By manipulating the ratios of two different anions, a series PNCs with various bright photoluminescence ranging from 452 to 646 nm could be done. On account of superior and adjustable photoluminescence over the visible spectral region, FAPbBr3 PNCs can be applied as a promising color-converting material in liquid-crystal display (LCD) backlight, white light-emitting diode (WLED), and inkjet printing pattern. As a proof of concept, FAPbBr3 PNCs with green emission were integrated in WLED and LCD backlight, accomplishing a color rendering index of 87.5 and a wide color gamut of 116%, respectively.

Facile Access to Wearable Device via Microfluidic Spinning of Robust and Aligned Fluorescent Microfibers.

Microfluidic spinning technology (MST) has drawn much attention owing to its ideal platform for ordered fluorescent fibers, along with their large-scale manipulation, high efficiency, flexibility, and environment friendliness. Here, we employed the MST to fabricate a series of uniform fluorescent microfibers. By adjusting the microfluidic spinning parameters, the as-prepared microfibers of different diameters are successfully obtained. For more practice, these regular arranged fibers could be formed to versatile fluorescent codes by using various microfluidic chips. Also, these versatile fluorescent fibers could be further weaved into a white fluorescent film via continuous and cross-spinning process, which could be applied in a white light emitting diode (WLED) and a wearable device. Besides, we investigated the MST-directed microreactors to carry out green synthesis of CdSe quantum dots (QDs) fibers by the knot of Y-type microfluidic chip. The as-prepared CdSe QDs show nice optical property and are good candidate as phosphors in WLED. This strategy offers a facile and environment-friendly route to fluorescent hybrid microfibers and might open their potential application in optical devices, security, and fluorescent coding.

Risk factors for pediatric intussusception complicated by loss of intestine viability in China from June 2009 to May 2014: a retrospective study.

PURPOSE: Intussusception is one of the most common causes of acute abdominal emergencies in infants and preschool children. Loss of intestine viability is the most serious complication of intussusception. This study aimed to investigate the risk factors for loss of intestine viability in pediatric intussusception cases among children. METHODS: Data were collected for operative pediatric intussusception cases (N = 316) from medical records of 5,537 hospitalized children due to intussusception between June 2009 and May 2014 in a pediatric surgery department of an academic teaching hospital in China. Seventy-six patients (24.1 %) of the operated intussusception cases had complication of loss intestine viability. RESULTS: Pediatric intussusception cases with loss of intestine viability and without loss of intestine viability were similar in terms of their age, malformation and season of admission. The median time of the duration from onset of symptoms to operative treatment was 23 h (range 3-90 h). The loss of intestine viability group of the intussusception cases was significantly associated with longer length of history (P = 0.000). Receiver operating characteristic curve analysis for length of history showed that the optimal ratio of sensitivity (0.70) and specificity (0.73) was calculated for the length of history longer than 27.5 h regarding loss of intestine viability of intussusception. In addition, the risk of loss of intestine viability was higher for female (31 %) than for male (20.8 %) (P = 0.049). The loss of intestine viability rate was also significantly higher in ileo-ileal intussusception cases than that of the other types (P = 0.033). However, there is no difference among the other groups. CONCLUSION: The result of our risk factor analysis for loss of intestine viability in pediatric intussusception cases may help develop a predictability index to prevent the complication to happen. Further prospective studies are required to confirm our findings.

Therapeutic effects of fucoidan in 6-hydroxydopamine-lesioned rat model of Parkinson's disease: Role of NADPH oxidase-1.

AIMS: To explore the effect of fucoidan treatment on oxidative stress-mediated dopaminergic neuronal damage and its potential mechanisms. METHODS: The effect of fucoidan was investigated in a 6-hydroxydopamine (6-OHDA) rat model of PD, an animal model considered appropriate for preclinical studies of PD therapy. The effects of fucoidan treatment on animal behavior and the survival ratio of dopaminergic neurons were investigated. We further observed the effect of fucoidan on microglia and the NADPH oxidases-1 (Nox1), a family of enzymes generating reactive oxygen species (ROS). RESULTS: We found that chronic fucoidan administration mitigated the motor dysfunction induced by 6-OHDA. Similarly, fucoidan reduced the loss of DA neurons in the SNc and DA fibers in the striatum in 6-OHDA-lesioned rats. Moreover, we found that fucoidan inhibited the 6-OHDA-stimulating expression of Nox1 in both tyrosine hydroxylase (TH)-positive neurons and non-TH-positive neurons, prevented Nox1-sensitive oxidative stress and cell damage in SNc neurons. Fucoidan also effectively inhibited nigral microglial activation. CONCLUSION: These results support the beneficial effect of fucoidan in 6-OHDA-lesioned rat model of PD. Fucoidan may suppress the Nox1-triggered oxidative stress in the SNc to protect DA neurons from 6-OHDA-induced toxicity and achieve its beneficial effect.