scholarly journals Study on the Mechanism of Efficient Extracellular Expression of Toxic Streptomyces Phospholipase D in Brevibacillus Choshinensis Under Mg2+ Stress

2022 ◽  
Author(s):  
Shaofeng Chen ◽  
Weide xiong ◽  
Xurui Zhao ◽  
Weiyi Luo ◽  
Xuhui Yan ◽  
...  
Keyword(s):  
Cell Growth ◽  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Cell Injury ◽  
Scale Production ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Study Results ◽  
Brevibacillus Choshinensis ◽  
P2 Promoter

Abstract BackgroundPhospholipase D (PLD) has significant advantages in the food and medicine industries due to its unique transphosphatidylation. However, the high heterologous expression of PLD is limited by its cytotoxicity. The present study sought to express the strong extracellular protein of PLD in the non-pathogenic Brevibacillus choshinensis (B. choshinensis).ResultsThe extracellular PLD was effectively expressed by the strong promoter (P2) under Mg2+ stress, with the highest activity of 1.0×104 U·L-1. The inductively coupled plasma–mass spectrometry (ICP-MS) results elucidated that the fast expression of PLD by P2 promoter without Mg2+ stress induced the ionic homeostasis perturbation caused by the highly enhanced Ca2+ influx, leading to cell injury or death. Under Mg2+ stress, Ca2+ influx was significantly inhibited, and the strengths of P2 promoter and HWP gene expression were weakened. The study results revealed that the mechanism of Mg2+ induced cell growth protection and PLD expression might be related to the lowered strength of PLD expression by P2 promoter repression to meet with the secretion efficiency of B. choshinensis, and the redistribution of intracellular ions accompanied by decreased Ca2+ influx.ConclusionsThe PLD production was highly improved under Mg2+ stress. By ICP-MS and qPCR analysis combined with other results, the mechanism of the efficient extracellular PLD expression under Mg2+ stress was demonstrated. The relatively low-speed PLD expression during cell growth alleviated cell growth inhibition and profoundly improved PLD production. These results provided a potential approach for the large-scale production of extracellular PLD and novel insights into PLD function.

scholarly journals Development and Application of Nanoparticle-Nanopolymer Composite Spheres for the Study of Environmental Processes

2021 ◽  
Vol 3 ◽  
Author(s):  
Robert J. Rauschendorfer ◽  
Kyle M. Whitham ◽  
Star Summer ◽  
Samantha A. Patrick ◽  
Aliandra E. Pierce ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Analytical Techniques ◽  
Inductively Coupled ◽  
The Past ◽  
Icp Ms ◽  
Sensitivity And Selectivity ◽  
Plasma Mass Spectrometry ◽  
Wide Scale ◽  
Synthetic Copolymer

Plastics have long been an environmental contaminant of concern as both large-scale plastic debris and as micro- and nano-plastics with demonstrated wide-scale ubiquity. Research in the past decade has focused on the potential toxicological risks posed by microplastics, as well as their unique fate and transport brought on by their colloidal nature. These efforts have been slowed by the lack of analytical techniques with sufficient sensitivity and selectivity to adequately detect and characterize these contaminants in environmental and biological matrices. To improve analytical analyses, microplastic tracers are developed with recognizable isotopic, metallic, or fluorescent signatures capable of being identified amidst a complex background. Here we describe the synthesis, characterization, and application of a novel synthetic copolymer nanoplastic based on polystyrene (PS) and poly(2-vinylpyridine) (P2VP) intercalated with gold, platinum or palladium nanoparticles that can be capped with different polymeric shells meant to mimic the intended microplastic. In this work, particles with PS and polymethylmethacrylate (PMMA) shells are used to examine the behavior of microplastic particles in estuarine sediment and coastal waters. The micro- and nanoplastic tracers, with sizes between 300 and 500 nm in diameter, were characterized using multiple physical, chemical, and colloidal analysis techniques. The metallic signatures of the tracers allow for quantification by both bulk and single-particle inductively-coupled plasma mass spectrometry (ICP-MS and spICP-MS, respectively). As a demonstration of environmental applicability, the tracers were equilibrated with sediment collected from Bellingham Bay, WA, United States to determine the degree to which microplastics bind and sink in an estuary based of grain size and organic carbon parameters. In these experiments, between 80 and 95% of particles were found to associate with the sediment, demonstrative of estuaries being a major anticipated sink for these contaminants. These materials show considerable promise in their versatility, potential for multiplexing, and utility in studying micro- and nano-plastic transport in real-world environments.

A New Preparation Method for Amorphous Co-B Alloys Nanoparticles

2011 ◽  
Vol 236-238 ◽  
pp. 1717-1720 ◽  
Author(s):  
Guo Qing Zhong ◽  
Qin Zhong ◽  
Hong Liang Zhou ◽  
Yu Qing Jia
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Room Temperature ◽  
Preparation Method ◽  
Average Diameter ◽  
Atomic Emission ◽  
Scale Production ◽  
Solid Reaction ◽  
Inductively Coupled ◽  
Amorphous Nanoparticles

The Co–B alloy can be prepared facilely by a solid-solid reaction of CoCl2•6H2O and KBH4 powders at room temperature. Various characterizations, such as the chemical analysis, inductively coupled plasma-atomic emission spectroscopy (ICP), powder X-ray diffraction, electron diffraction and TEM have been performed. The results indicate that the Co-B alloy obtained by the solid-solid reaction is amorphous nanoparticles. The composition of the alloy is Co1.36B. The average diameter of the Co–B alloy nanoparticles is 30nm–50nm. The room temperature solid-solid reaction is mainly a surface reaction. The direct solid solid reaction between the borohydride and some metal-salts is thermodynamically possible. This simple preparation method may also be used for the large-scale production of the amorphous nanoparticles of some metal-boron alloys.

LA-MC-ICP-MS U-Pb dating of low-U garnets reveals multiple episodes of skarn formation in the volcanic-hosted iron mineralization system, Awulale belt, Central Asia

2019 ◽  
Vol 132 (5-6) ◽  
pp. 1031-1045
Author(s):  
Shuang Yan ◽  
Renjie Zhou ◽  
He-Cai Niu ◽  
Yue-xing Feng ◽  
Ai Duc Nguyen ◽  
...  
Keyword(s):  
Central Asia ◽  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Volcanic Rocks ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Two Samples ◽  
Plasma Mass Spectrometry ◽  
Iron Deposits ◽  
Multiple Episodes

Abstract Volcanic-hosted iron deposits of the eastern Awulale metallogenetic belt in Central Asia possess a reserve of over 1.2 billion tons of iron ores and constitute one of the most important basements for high-grade iron resources in China. Skarns are widespread in these deposits and closely associated with iron mineralization. The ages of these skarns are unclear, and their genesis remains debated, preventing further investigation into their metallogenic processes. We focused on garnets in nine ore-bearing skarns from three large-scale iron deposits (Chagangnuoer, Dunde, and Beizhan) in the eastern Awulale belt. U-Pb dating was conducted on these garnets using our in-house reference material, the Taochong garnet (TC-13, Pb-Pb isochron age: 126.2 ± 2.3 Ma, initial 207Pb/206Pb ratio: 0.845 ± 0.022). Laser-ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS) was employed in the garnet U-Pb dating, and high-precision U-Pb ages (0.3%–1.6%) were obtained, highlighting the advantages of LA-MC-ICP-MS in dating low-U minerals. The garnet U-Pb ages of the nine skarn samples fall into three groups, i.e., 329.0 ± 5.1–326 ± 3.3 Ma (two samples), 316.3 ± 2.9–311.2 ± 2.4 Ma (six samples), and 295.6 ± 1.0 Ma (one sample), implying three episodes of skarn alteration in the volcanic-hosted iron mineralization system. The first and second episodes of skarns formed as a result of contact metasomatism between coeval volcanic rocks and limestone, and they have economically important iron mineralization. The third was likely caused by a local postcollision granitic intrusion, but its metallogenic potential deserves further assessment.

Single Particle Inductively Coupled Plasma Mass Spectrometry: Investigating Nonlinear Response Observed in Pulse Counting Mode and Extending the Linear Dynamic Range by Compensating for Dead Time Related Count Losses on a Microsecond Timescale

2019 ◽  
Author(s):  
Ingo Strenge ◽  
Carsten Engelhard
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Nonlinear Response ◽  
Dynamic Range ◽  
Dead Time ◽  
Inorganic Nanoparticles ◽  
Linear Dynamic Range ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

<p>The article demonstrates the importance of using a suitable approach to compensate for dead time relate count losses (a certain measurement artefact) whenever short, but potentially strong transient signals are to be analysed using inductively coupled plasma mass spectrometry (ICP-MS). Findings strongly support the theory that inadequate time resolution, and therefore insufficient compensation for these count losses, is one of the main reasons for size underestimation observed when analysing inorganic nanoparticles using ICP-MS, a topic still controversially discussed.</p>

Fast Turn-around Failure Analysis of Metal Interconnection Using FIB and LA ICP-MS

2010 ◽  
Author(s):  
Zixiao Pan ◽  
Wei Wei ◽  
Fuhe Li
Keyword(s):  
Failure Analysis ◽  
Inductively Coupled Plasma ◽  
Structural Damage ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Detection Sensitivity ◽  
Chemical Contamination ◽  
Inductively Coupled ◽  
Minimal Sample ◽  
Icp Ms

Abstract This paper introduces our effort in failure analysis of a 200 nm thick metal interconnection on a glass substrate and covered with a passivation layer. Structural damage in localized areas of the metal interconnections was observed with the aid of focused ion beam (FIB) cross-sectioning. Laser ablation inductively coupled plasma mass spectroscopy (LA ICP-MS) was then applied to the problematic areas on the interconnection for chemical survey. LA ICP-MS showed direct evidence of localized chemical contamination, which has likely led to corrosion (or over-etching) of the metal interconnection and the assembly failure. Due to the high detection sensitivity of LA ICP-MS and its compatibility with insulating material analysis, minimal sample preparation is required. As a result, the combination of FIB and LA ICP-MS enabled successful meso-scale failure analysis with fast turnaround and reasonable cost.

Sign in / Sign up

Export Citation Format

Share Document