scholarly journals Photoacoustics for listening to Metal Nanoparticles Super-Aggregates

2021 ◽  
Author(s):  
Roberto Li Voti ◽  
Grigore Leahu ◽  
Concita Sibilia ◽  
Roberto Matassa ◽  
Giuseppe Familiari ◽  
...  

Photoacoustic detection signal has been used to build a new strategy to determine the mesoscale self-assembly of metal nanoparticles in terms of size distribution and aggregate packing density (metal nanoparticles...

2021 ◽  
Author(s):  
Ping-Ru Su ◽  
Tao Wang ◽  
Pan-Pan Zhou ◽  
Xiao-Xi Yang ◽  
Xiao-Xia Feng ◽  
...  

Abstract Design and engineering of highly efficient emitting materials with assembly-induced luminescence, such as room temperature phosphorescence (RTP) and aggregation-induced emission (AIE), have stimulated extensive efforts. Here, we propose a new strategy to obtain size-controlled Eu3+-complex nanoparticles (Eu-NPs) with self-assembly induced luminescence (SAIL) characteristics without encapsulation or hybridization. Compared with previous RTP or AIE materials, the SAIL phenomena of increased luminescence intensity and lifetime in aqueous solution for the proposed Eu-NPs are due to the combined effect of self-assembly in confining the molecular motion and shielding the water quenching. As a proof of concept, we also show that this system can be further applied in bioimaging, temperature measurement and HClO sensing. The SAIL activity of the rare-earth (RE) system proposed here offers a further step forward on the roadmap for the development of RE light conversion systems and their integration in bioimaging and therapy applications.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Artur Tuktamyshev ◽  
Alexey Fedorov ◽  
Sergio Bietti ◽  
Stefano Vichi ◽  
Riccardo Tambone ◽  
...  

AbstractWe investigated the nucleation of Ga droplets on singular GaAs(111)A substrates in the view of their use as the seeds for the self-assembled droplet epitaxial quantum dots. A small critical cluster size of 1–2 atoms characterizes the droplet nucleation. Low values of the Hopkins-Skellam index (as low as 0.35) demonstrate a high degree of a spatial order of the droplet ensemble. Around $$350\,^{\circ }\hbox {C}$$ 350 ∘ C the droplet size distribution becomes bimodal. We attribute this observation to the interplay between the local environment and the limitation to the adatom surface diffusion introduced by the Ehrlich–Schwöbel barrier at the terrace edges.


2021 ◽  
Vol 11 (11) ◽  
pp. 1766-1773
Author(s):  
Lei Jin ◽  
Tong Yang

The modulatory effect of miR-21 on the proliferation of melanoma cells through stimulation of PTEN (Phosphatase and tensin homologue deleted on chromosome 10) expression was investigated in the current study. PTEN, as a tumor suppressor, is expressed in low levels in melanoma tissues and cell lines. Nevertheless, miR-21 can stimulate cancer development and suppress cell apoptosis. Overexpression of PTEN substantially impaired the proliferation of miR-21-treated melanoma cells. In addition, miR-21 and PTEN were observed to exhibit a combinatorial effect, whereas miR-21 could negatively regulate the expression of PTEN. In conclusion, these findings demonstrate that miR-21 affects melanoma development by targeting PTEN, establishing a new strategy for treating malignant melanoma. Furthermore, in this study, microparticles and nanoparticles were employed as carriers to construct, through the self-assembly method, nanocapsules carrying miR-21 in order to develop an efficient nanocapsule delivery system of miR-21 against melanoma cells.


2013 ◽  
Vol 711 ◽  
pp. 327-332
Author(s):  
Yi Su ◽  
Zhen Zhang ◽  
Tao Zhang ◽  
Ming Li Yang ◽  
Mei Lin ◽  
...  

The detection mechanism of Magnetic Flux Leakage (MFL) Method of elevator cable is proposed. Using Gauss-Mercury method to analyze the influence of different factors that lift-off value, fracture width, broken wires number and diameter and depth all that based on the collecting experimental system of MFL signals. The method can be used to optimize the detection probe design and detection signal processing.


2007 ◽  
Vol 534-536 ◽  
pp. 1621-1624
Author(s):  
Yuto Amano ◽  
Takashi Itoh ◽  
Hoshiaki Terao ◽  
Naoyuki Kanetake

For precise property control of sintered products, it is important to know the powder characteristics, especially the packing density of the powder. In a previous work, we developed a packing simulation program that could make a packed bed of spherical particles having particle size distribution. In order to predict the packing density of the actual powder that consisted of nonspherical particles, we combined the packing simulation with a particle shape analysis. We investigated the influence of the particle size distribution of the powder on the packing density by executing the packing simulation based on particle size distributions of the actual milled chromium powders. In addition, the influence of the particle shape of the actual powder on the packing density was quantitatively analyzed. A prediction of the packing density of the milled powder was attempted with an analytical expression between the particle shape of the powder and the packing simulation. The predicted packing densities were in good agreement with the actual data.


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