scholarly journals Functional Polyselenoureas for Selective Gold Recovery Prepared from Catalyst-Free Multicomponent Polymerizations of Elemental Selenium

2019 ◽  
Author(s):  
Xiuying Wu ◽  
Hua Lin ◽  
Fengying Dai ◽  
Rongrong Hu ◽  
Ben Zhong Tang
Keyword(s):  
Metal Ion ◽  
Synthetic Methods ◽  
Elemental Selenium ◽  
Aromatic Diamines ◽  
Polymer Complexes ◽  
Molecular Weights ◽  
Long Term Stability ◽  
Catalyst Free ◽  
High Yields

Selenium-containing polymers with fascinating functionalities are highly desired but are rarely developed due to their underexplored synthetic methods. Herein, through careful design of monomer structures and polymerization conditions, a series of catalyst-free multicomponent polymerizations (MCPs) of elemental selenium with aliphatic/aromatic diamines and diisocyanides were reported to directly convert elemental selenium to polyselenoureas with long-term stability, good solubility, well-characterized structures, and unique functionalities. The MCPs enjoy wide monomer scope and fast conversion in 1 min, delivering 18 polyselenoureas with high molecular weights (Mws up to 94 600 g/mol) in high yields (up to 99%). Furthermore, the polyselenoureas can be used for the extraction of Au3+ from mixed metal ion solutions in practical conditions with high selectivity, sensitivity (< 1 μg/L), efficiency (> 99.99%), and capacity (up to 665.60 mg·Au3+/g) within 1 min, and elemental gold can be further recovered after pyrolysis of the polymer complexes.

scholarly journals Functional Polyselenoureas for Selective Gold Recovery Prepared from Catalyst-Free Multicomponent Polymerizations of Elemental Selenium

2019 ◽  
Author(s):  
Xiuying Wu ◽  
Hua Lin ◽  
Fengying Dai ◽  
Rongrong Hu ◽  
Ben Zhong Tang
Keyword(s):  
Metal Ion ◽  
Synthetic Methods ◽  
Elemental Selenium ◽  
Aromatic Diamines ◽  
Polymer Complexes ◽  
Molecular Weights ◽  
Long Term Stability ◽  
Catalyst Free ◽  
High Yields

Selenium-containing polymers with fascinating functionalities are highly desired but are rarely developed due to their underexplored synthetic methods. Herein, through careful design of monomer structures and polymerization conditions, a series of catalyst-free multicomponent polymerizations (MCPs) of elemental selenium with aliphatic/aromatic diamines and diisocyanides were reported to directly convert elemental selenium to polyselenoureas with long-term stability, good solubility, well-characterized structures, and unique functionalities. The MCPs enjoy wide monomer scope and fast conversion in 1 min, delivering 18 polyselenoureas with high molecular weights (Mws up to 94 600 g/mol) in high yields (up to 99%). Furthermore, the polyselenoureas can be used for the extraction of Au3+ from mixed metal ion solutions in practical conditions with high selectivity, sensitivity (< 1 μg/L), efficiency (> 99.99%), and capacity (up to 665.60 mg·Au3+/g) within 1 min, and elemental gold can be further recovered after pyrolysis of the polymer complexes.

scholarly journals An approach for long-term, multi-probe Neuropixels recordings in unrestrained rats

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Thomas Zhihao Luo ◽  
Adrian Gopnik Bondy ◽  
Diksha Gupta ◽  
Verity Alexander Elliott ◽  
Charles D Kopec ◽  
...  
Keyword(s):  
Cost Effective ◽  
New Approach ◽  
Neural Recordings ◽  
Chronic Recording ◽  
Long Term Stability ◽  
Multiple Cycles ◽  
Single Unit Recordings ◽  
Freely Moving ◽  
High Yields

The use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here, we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.

scholarly journals An approach for long-term, multi-probe Neuropixels recordings in unrestrained rats

2020 ◽  
Author(s):  
Thomas Zhihao Luo ◽  
Adrian G. Bondy ◽  
Diksha Gupta ◽  
Verity A. Elliott ◽  
Charles D. Kopec ◽  
...  
Keyword(s):  
Cost Effective ◽  
New Approach ◽  
Neural Recordings ◽  
Chronic Recording ◽  
Long Term Stability ◽  
Multiple Cycles ◽  
Single Unit Recordings ◽  
Freely Moving ◽  
High Yields

AbstractThe use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.

Ultrahigh water permeance of a reduced graphene oxide nanofiltration membrane for multivalent metal ion rejection

2020 ◽  
Vol 56 (95) ◽  
pp. 15068-15071
Author(s):  
Fangfang Dai ◽  
Risheng Yu ◽  
Ruobing Yi ◽  
Jian Lan ◽  
Rujie Yang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Metal Ion ◽  
Nanofiltration Membrane ◽  
Long Term Stability ◽  
Ion Rejection ◽  
Reduced Graphene ◽  
Multivalent Metal ◽  
Water Permeance

A simple way to fabricate pure rGO membranes shows ultrahigh water permeance and excellent multivalent metal ion rejection, as well as long-term stability.

scholarly journals Development of Electric and Chemical Microthrusters

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
M. Tajmar ◽  
C. A. Scharlemann
Keyword(s):  
Applied Sciences ◽  
Electric Propulsion ◽  
Metal Ion ◽  
High Performance ◽  
Specific Impulse ◽  
Long Term Stability ◽  
University Of Applied Sciences ◽  
Green Propellants ◽  
The University

The increasing application of microsatellites (from 10 kg up to 100 kg) as well as CubeSats for a rising number of various missions demands the development of miniaturized propulsion systems. Fotec and The University of Applied Sciences at Wiener Neustadt is developing a number of micropropulsion technologies including both electric and chemical thrusters targeting high performance at small scales. Our electric propulsion developments include a series of FEEP (field emission electric propulsion) thrusters, of which the thrust ranges fromμN to mN level. The thrusters are highly integrated into clusters of indium liquid-metal-ion sources that can provide ultralow thrust noise and long-term stability. We are also developing a micro PPT thruster that enables pointing capabilities for CubeSats. For chemical thrusters, we are developing novel micromonopropellant thrusters with several hundred mN as well as a 1–3 N bipropellant microrocket engine using green propellants and high specific impulse performance. This paper will give an overview of our micropropulsion developments at Fotec, highlighting performance as well as possible applications.

scholarly journals Fabrication of Co3O4/NiCo2O4 Nanocomposite for Detection of H2O2 and Dopamine

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 452
Author(s):  
Tianjiao Liu ◽  
Xiaoyuan Zhang ◽  
Kun Fu ◽  
Nan Zhou ◽  
Jinping Xiong ◽  
...  
Keyword(s):  
Metal Ion ◽  
High Selectivity ◽  
Metal Organic Framework ◽  
Accessible Surface Area ◽  
Detection Range ◽  
Calcination Process ◽  
Long Term Stability ◽  
Metal Organic ◽  
Accessible Surface

Herein, the Co3O4/NiCo2O4 nanocomposite has been prepared as a novel electrochemical sensor to accurately detect hydrogen peroxide (H2O2) and glucose. ZIF-67 is a metal-organic framework (MOF) with Co as the center metal ion. Co3O4 can be obtained by calcination of ZIF-67 at 700 °C, which can retain the structure of ZIF-67. The hollow Co3O4 nanocrystal was synthesized based on a calcination process of ZIF-67. This open structure can promote the whole Co3O4/NiCo2O4 nanocomposite larger accessible surface area and reactive sites. Co3O4 has good electrocatalytic performance, which has been applied in many fields. Moreover, H2O2 and dopamine sensing tests indicate that the as-prepared non-enzymatic electrochemical biosensor has good detection properties. The testing results indicate the as-prepared biosensor has a wide detection range, low detection limit, high selectivity, and long-term stability. These testing results suggest the potential application in food security, biomedicine, environmental detection, and pharmaceutical analysis.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

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