High-yield synthesis of CsPbBr3 nanoparticles: Diphenylphosphine as a reducing agent and its effect in Pb-seeding nucleation and growth

2021 ◽  
Author(s):  
Eder Antonio Castillo-Ruiz ◽  
Diana Fabiola Garcia-Gutierrez ◽  
Domingo Ixcóatl Garcia-Gutierrez
Keyword(s):  
Nucleation And Growth ◽  
Reducing Agent ◽  
High Yield ◽  
Reaction Yield ◽  
High Quality ◽  
Stabilizing Agents ◽  
Nucleation Sites ◽  
Nucleation Mechanisms ◽  
Attractive Option ◽  
Mass Increment

Abstract Based on the reported nucleation mechanisms for CsPbX3 and II-VI/IV-VI quantum dots, CsPbBr3 nanoparticles with a high reaction-yield, up to 393% mass-increment, were synthesized by the hot-injection method. The introduction of diphenylphosphine (DPP) as a reducing agent improved nanoparticle nucleation and growth, giving out evidence for Pb-seeding in CsPbBr3 nanoparticles formation. Additionally, a clear influence of the DPP in a CsPbBr3-Cs4PbBr6 incomplete phase transformation was observed, marked by the appearance of several PbBr2 nanoparticles, indicating the need for an improved ratio between the stabilizing agents and the precursors, due to the increased number of nucleation sites produced by the DPP. The resulting CsPbBr3 nanoparticles showed high quality, as they displayed 70%-90% photoluminescence quantum yield (PLQY), narrow size distribution with an average nanoparticle size of ~10 nm and the characteristic cubic morphology reported in previous works. This increment in CsPbBr3 nanoparticles’ reaction yield will contribute to making them a more attractive option for different optoelectronic applications.

Selection of high-quality sperm with thousands of parallel channels

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Mohammad Simchi ◽  
Jason Riordon ◽  
Jae Bem You ◽  
Yihe Wang ◽  
Sa Xiao ◽  
...  
Keyword(s):  
Clinical Practice ◽  
High Selectivity ◽  
High Yield ◽  
Sperm Selection ◽  
High Quality ◽  
Parallel Channels ◽  
Selection Of

A 3D-structured sperm selection device is presented that achieves both high selectivity and high yield via thousands of parallel channels. The device significantly outperforms the best clinical practice by selecting ∼100 000 of higher-quality sperm.

scholarly journals A Novel and Efficient High-Yield Method for Preparing Bacterial Ghosts

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 420
Author(s):  
Yi Ma ◽  
Liu Cui ◽  
Meng Wang ◽  
Qiuli Sun ◽  
Kaisheng Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Expression System ◽  
High Yield ◽  
Wild Type ◽  
High Quality ◽  
Efficient Protection ◽  
Bacterial Ghosts ◽  
Cell Envelopes ◽  
Extracellular Structures ◽  
First Time

Bacterial ghosts (BGs) are empty cell envelopes possessing native extracellular structures without a cytoplasm and genetic materials. BGs are proposed to have significant prospects in biomedical research as vaccines or delivery carriers. The applications of BGs are often limited by inefficient bacterial lysis and a low yield. To solve these problems, we compared the lysis efficiency of the wild-type protein E (EW) from phage ΦX174 and the screened mutant protein E (EM) in the Escherichia coli BL21(DE3) strain. The results show that the lysis efficiency mediated by protein EM was improved. The implementation of the pLysS plasmid allowed nearly 100% lysis efficiency, with a high initial cell density as high as OD600 = 2.0, which was higher compared to the commonly used BG preparation method. The results of Western blot analysis and immunofluorescence indicate that the expression level of protein EM was significantly higher than that of the non-pLysS plasmid. High-quality BGs were observed by SEM and TEM. To verify the applicability of this method in other bacteria, the T7 RNA polymerase expression system was successfully constructed in Salmonella enterica (S. Enterica, SE). A pET vector containing EM and pLysS were introduced to obtain high-quality SE ghosts which could provide efficient protection for humans and animals. This paper describes a novel and commonly used method to produce high-quality BGs on a large scale for the first time.

Physical Based Microstructure Modelling Coupled with Nucleation Theory during and after Hot Forming of AA5083

2010 ◽  
Vol 89-91 ◽  
pp. 509-514
Author(s):  
Pavel Sherstnev ◽  
Christof Sommitsch ◽  
Stefan Mitsche ◽  
Carsten Melzer
Keyword(s):  
Aluminium Alloy ◽  
Hot Rolling ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
Grain Structure ◽  
Nucleation Theory ◽  
Structure Evolution ◽  
Nucleation Sites ◽  
Nucleation Mechanisms ◽  
Backscatter Diffraction

A physical model based on three types of dislocations and three nucleation sites for recrystallized grain is applied to hot rolling simulation. This model was implemented into a commercial Finite Element (FE) analysis package FORGE 2008 to calculate both the structure evolution during and the recrystallized volume fraction after hot working of aluminium alloy 5083. It is shown that the main nucleation mechanisms in the aluminium alloy are the particle stimulated nucleation (PSN) and nucleation at grain boundaries. Hence the precipitation kinetics during homogenisation was investigated by use of the thermodynamic calculation software MatCalc. To validate the simulation results hot rolling experiments were performed by means of a laboratory mill. The grain structure evolution was analysed by electron backscatter diffraction (EBSD).

High Microsatellite and SNP Genotyping Success Rates Established in a Large Number of Genomic DNA Samples Extracted From Mouth Swabs and Genotypes

2006 ◽  
Vol 9 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Josine L. Min ◽  
Nico Lakenberg ◽  
Margreet Bakker-Verweij ◽  
Eka Suchiman ◽  
Dorret I. Boomsma ◽  
...  
Keyword(s):  
Success Rate ◽  
Genomic Dna ◽  
Snp Genotyping ◽  
High Yield ◽  
Success Rates ◽  
Nucleotide Polymorphism ◽  
High Quality ◽  
Single Nucleotide ◽  
Dna Yield ◽  
Yield And Quality

AbstractIn this article, we present the genomic DNA yield and the microsatellite and single nucleotide polymorphism (SNP) genotyping success rates of genomic DNA extracted from a large number of mouth swab samples. In total, the median yield and quality was determined in 714 individuals and the success rates in 378,480 genotypings of 915 individuals. The median yield of genomic DNA per mouth swab was 4.1 μg (range 0.1–42.2 μg) and was not reduced when mouth swabs were stored for at least 21 months prior to extraction. A maximum of 20 mouth swabs is collected per participant. Mouth swab samples showed in, respectively, 89% for 390 microsatellites and 99% for 24 SNPs a genotyping success rate higher than 75%. A very low success rate of genotyping (0%–10%) was obtained for 3.2% of the 915 mouth swab samples using microsatellite markers. Only 0.005% of the mouth swab samples showed a geno-typing success rate lower than 75% (range 58%–71%) using SNPs. Our results show that mouth swabs can be easily collected, stored by our conditions for months prior to DNA extraction and result in high yield and high-quality DNA appropriate for genotyping with high success rate including whole genome searches using microsatellites or SNPs.

scholarly journals N-Dopant-Mediated Growth of Metal Oxide Nanoparticles on Carbon Nanotubes

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1882
Author(s):  
Jin Ah Lee ◽  
Won Jun Lee ◽  
Joonwon Lim ◽  
Sang Ouk Kim
Keyword(s):  
Carbon Nanotubes ◽  
Metal Oxide ◽  
Carbon Nanomaterials ◽  
Wide Spectrum ◽  
Metal Oxide Nanoparticles ◽  
Nucleation And Growth ◽  
Oxide Nanoparticles ◽  
Metal Oxide Nanoparticle ◽  
Nucleation Sites ◽  
Direct Growth

Metal oxide nanoparticles supported on heteroatom-doped graphitic surfaces have been pursued for several decades for a wide spectrum of applications. Despite extensive research on functional metal oxide nanoparticle/doped carbon nanomaterial hybrids, the role of the heteroatom dopant in the hybridization process of doped carbon nanomaterials has been overlooked. Here, the direct growth of MnOx and RuOx nanoparticles in nitrogen (N)-doped sites of carbon nanotubes (NCNTs) is presented. The quaternary nitrogen (NQ) sites of CNTs actively participate in the nucleation and growth of the metal nanoparticles. The evenly distributed NQ nucleation sites mediate the generation of uniformly dispersed <10 nm diameter MnOx and RuOx nanoparticles, directly decorated on NCNT surfaces. The electrochemical performance of the resultant hybridized materials was evaluated using cyclic voltammetry. This novel hybridization method using the dopant-mediated nucleation and growth of metal oxides suggests ways that heteroatom dopants can be utilized to optimize the structure, interface and corresponding properties of graphitic carbon-based hybrid materials.

A micromechanistic model of microstructure development during the combustion synthesis process

1995 ◽  
Vol 10 (4) ◽  
pp. 962-980 ◽  
Author(s):  
Yangsheng Zhang ◽  
Gregory C. Stangle
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Combustion Synthesis ◽  
Growth Parameters ◽  
Experimental Studies ◽  
Nucleation And Growth ◽  
Synthesis Process ◽  
Product Phase ◽  
Nucleation Sites ◽  
Rate Of Increase

The influence of the key nucleation and grain growth parameters on (i) the evolution of the microstructure of the product phase (on a microscopic level) and (ii) the combustion synthesis process (on a macroscopic level) were investigated for the combustion synthesis process in the Nb-C system. This work is an integral part of the continuing effort1–3 to develop a more complete theoretical model for combustion synthesis processes in general. In particular, the nucleation and growth of the NbC(s) product phase from the supersaturated liquid Nb/C mixture that appears briefly during the combustion synthesis process was treated in a greater detail by using a decidedly more sophisticated treatment of the nucleation and growth process (as developed in the field of rapid solidification and welding). It was shown that the microstructure of the NbC(s) product phase, including the evolution of the grain size and the size distribution, and the development of the grain's morphology, as well as the combustion wave velocity, are significantly influenced by the total number density of the nucleation sites, nmax, that are present in the system. The grain size distribution was shown to possess a monosize distribution, since during the combustion synthesis process the rate of increase of the degree of local undercooling was very high so that the nucleation process took place (locally) during a very brief period of time. This work provides a sound basis for developing a better control of the microstructure, and for a better understanding and interpretation of the results of related experimental studies.

Toward the High-Quality Graphene for Optoelectronic Applications by Optimization of the Growth and Transfer Parameters

2013 ◽  
Vol 834-836 ◽  
pp. 33-36
Author(s):  
Lang Wang ◽  
Jian Hua Zhang ◽  
Lian Qiao Yang
Keyword(s):  
Surface Condition ◽  
Chemical Vapor ◽  
Reflow Process ◽  
High Quality ◽  
Cu Substrate ◽  
Nucleation Sites ◽  
Higher Temperature ◽  
Transfer Parameters ◽  
Optoelectronic Applications ◽  
Pre Treatment

In this paper, the process parameters of graphene during fabrication and transfer are investigated. Cu is utilized as the substrate and chemical vapor deposition are used to obtain graphene. The results show that, the surface condition of the Cu substrate tends to be worse than as-received after a relatively higher temperature (1035°C) annealing and growth process, which lead to bad graphene quality. In addition, pre-treatment of Cu substrate by acetic acid is helpful to reduce the nucleation sites. Reflow process before PMMA etching is an effective method to eliminate the wrinkles formed during transfer. High-quality graphene for optoelectronic applications were obtained based on the optimized fabrication and transfer process.

scholarly journals Comportamiento de híbridos de maíz intersintéticos generados de selección recíproca recurrente.

2016 ◽  
Vol 5 ◽  
pp. 131
Author(s):  
S. K. Vasal ◽  
N. Vergara ◽  
S. McLean
Keyword(s):  
Marked Decrease ◽  
High Yield ◽  
Yield Performance ◽  
Maize Germplasm ◽  
Lattice Design ◽  
Simple Lattice ◽  
Single Cross ◽  
Attractive Option ◽  
Per Se ◽  
National Programs

The populations 21 (Tuxpeño) and 32 (Eto Blanco) are known to be heterotic and are being improved using a modified interpopulation improvement system. In this study, synthetics with 3, 6, 9 and 12 lines were developed from each population and then intercrossed in a design-2 mating system to generate 16 intersynthetic hybrids. The 16 intersynthetic hybrids, 8 parcntal synthetics, and a single cross hybrid entry as a control were evaluated in four localities in a 5 x 5 simple lattice design with 4 replications. The yield performance of synthetics from Eto and Tuxpeño involving 6- 12 lines and the 3-lines Tuxpeño synthetics was similar (5.8 - 6.3 t/ha). However, the 3-1ine Eto synthctic registered a marked decrease in yield (5.1 t/ha). The bettcr parent heterosis of intersynthetic hybrids ranged from 11.1 to 29.6%. Usually, crosses among synthetics involving a fewer lines resulted in higher heterosis compared to synthetic crosses involving more than 3 lines. The results suggest that intersynthetic hybrids formed from 6 - 9 lines seem more appealing considering the level of heterosis (>20.0%) and a high yield per se of parental varieties. The intersynthetic hybrids offer an attractive option for those national programs with newly initiated hybrid projects, for creating hybrid -oriented maize germplasm and inbred line development.

Barofractionation as an Innovative Method to Obtain Pectic Polysaccharides

2021 ◽  
Vol 899 ◽  
pp. 599-605
Author(s):  
Dara Slobodova ◽  
Raisa Gorshkova ◽  
Stanislav Pankov
Keyword(s):  
High Pressure ◽  
Physicochemical Parameters ◽  
New Method ◽  
High Yield ◽  
Dynamic Mode ◽  
High Quality ◽  
Pectic Polysaccharides ◽  
Ph Values ◽  
Pectin Polysaccharides ◽  
Innovative Method

An innovative method has been developed and an installation has been created for obtaining pectin polysaccharides in a dynamic mode under the influence of high pressure. The process of degradation of protopectin at various pH values pH of the hydrolyzing agent was studied using the example of sunflower baskets. It has been established that the use of the new method makes it possible to obtain high-quality target products with a high yield in gentle conditions. The possibility of combining the stages of hydrolysis-extraction and fractionation has been demonstrated, which makes it possible to control the process of obtaining pectic polysaccharides in the direction of obtaining substances with specified physicochemical parameters.

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