CsPbBr 3 perovskite quantum dots (QDs) have attracted great attention due to their different photoluminescent and electronic properties. However, the toxicity and low stability hinder their practical application. Here, low-toxicity Sn-substituted cesium lead bromide perovskite QDs were synthesized via the room temperature crystallization method. A phase transition of the perovskite quantum dots with the concentration of Sn increasing was found: the crystal phase of CsPbBr 3 :Sn perovskite QDs starts to be transformed into Cs 4 PbBr 6 :Sn perovskite QDs when the SnBr 2 precursor exceeds 30 at. %. In this process, the controlled-color emission of perovskite QDs from green to blue can be realized. To improve the stability of quantum dots, CsPbBr 3 :Sn@SiO 2 and Cs 4 PbBr 6 :Sn@SiO 2 were synthesized via a simple one-step synthesis with hydrolysis of tetramethoxysilane in toluene solution containing perovskite QDs. The results show that CsPbBr 3 :Sn@SiO 2 and Cs 4 PbBr 6 :Sn@SiO 2 exhibited higher water stability and water solubility than pure QDs. In a mixed solution of toluene and water, the PL intensity of the CsPbBr 3 :Sn@SiO 2 retained 46.7% and the Cs 4 PbBr 6 :Sn@SiO 2 was 59.6% even after 24 h of reaction compared with the initial intensities. These quantum dots with good stability and luminescent property developed in this work are expected to be widely used in light-emitting diodes.

A Zakharov–Kuznetsov (ZK) equation, a modified ZK (mZK) equation, and a coupled ZK (cZK) equation for small but finite amplitude dust acoustic waves in a magnetized two-ion-temperature dusty plasma with dust size distribution have been investigated in this paper. The variations of the linear dispersion relation and group velocity, nonlinear solitary wave amplitude, and width with an arbitrary dust size distribution function are studied numerically. We conclude that they all increase as the total number density of dust grains increases, and they are greater for unusual dusty plasma (the number density of larger dust grains is greater than that of smaller dust grains) than that of usual dusty plasma (the number density of smaller dust grains is greater than that of larger dust grains). It is noted that the frequency of the linear wave increases as the wave number along the magnetic direction increases. Furthermore, the width of the nonlinear waves increases but its amplitude decreases as the wave number along the magnetic direction increases.

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Breast cancer brain metastasis (BCBM) remains a major clinical problem. Approximately 10–16% of patients with breast cancer develop brain metastases (BCBM). However, no systemic therapy has gained regulatory approval for the specific treatment of BCBM and this remains an area of persistent, unmet medical need. Rapid, predictive and clinically-relevant animal models are critical to study the biology of brain metastases and to identify effective therapeutic approaches for patients with BCBM. Here, we describe a method for efficient establishment of orthotopic mouse models of patient-derived brain metastases via an improved intracarotid injection protocol that permits tumor cell growth in the unique brain microenvironment without compromising the blood-brain barrier (BBB). We demonstrate that our newly improved models of patient-derived brain metastases recapitulate the histologic, molecular, and genetic characteristics of their matched patient tumor specimens and thus represent a potentially powerful tool for pre-clinical and translational research.

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View Article OnlineHalide perovskite quantum dots (QDs) have been considered to be an outstanding optoelectronic material. However, their poor stability caused by their large specific surface area and high sensitivity to moisture, greatly hinders their practical application. Here, a simple silica (SiO )-2 coating process is adopted to solve this problem without affecting their optical properties. Firstly, monodispersed CsPbX (X = Cl, Br, I) with 3 cubic morphologies (~8 nm edge lengths) are successfully obtained using a modified hot-injection method, omitting the links of drying and degassing which can reduce energy consumption and save cost. Next, CsPbX @SiO nanoparticles with spherical morphologies (1.2 μm) are 3 2 obtained through a novel method based on the high hydrolytic rate of tetramethyl orthosilicate (TMOS) using CsPbX as the precursor. 3 Photostability tests indicate that the CsPbBr @SiO QDs are markedly more stable than the pure CsPbBr . The PL intensity of the 3 2 3CsPbBr @SiO dispersed in a mixed solution of toluene and water retained 77 % of the initial value even after 12 h, which was much higher 3 2 than the pure CsPbBr . Similar experimental results are also observed when CsPbBr @SiO and CsPbBr were dispersed in toluene exposed to 3 3 2 3air. This material provides a novel platform for the application of perovskite quantum dots in light-emitting device applications. RESEARCH PAPER2 inorganic perovskite QDs without destroying their luminescent properties in the presence of trace amounts of water. Toluene, as a nonpolar solvent, was selected as the solvent in the coating process 66 | ES Mater. Manuf., 2019, 4, 66-73 © Engineered Science Publisher LLC 2019 3 3 compared to most common NTSC TV color standards (solid white triangle); (e) the time-resolved fluorescence decay curves of colloidal CsPbX QDs. 3 68 | ES Mater. Manuf., 2019, 4, 66-73

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