4.9% Au stabilizes Ag in atomically homogenous bimetallic alloy for anisotropic nanocrystals with enhanced stability under light irradiation

Nanoscale ◽  
2021 ◽  
Author(s):  
Zhenying Xu ◽  
Hao Xie ◽  
Weixiang Ye ◽  
Yi Yang ◽  
Weihai Ni
Keyword(s):  
Light Irradiation ◽  
Practical Applications ◽  
Bimetallic Alloys ◽  
Bimetallic Alloy ◽  
High Fraction ◽  
The Stability ◽  
Enhanced Stability

Instability problems encountered by Ag nanocrystals largely limits their use in practical applications. In AuAg bimetallic alloys the stability of Ag can be greatly enhanced, whereas doping a high fraction...

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

Nanoscale Structural and Chemical Segregation in Pt50Ru50 Electrocatalysts

2001 ◽  
Vol 7 (S2) ◽  
pp. 1112-1113
Author(s):  
Rhonda M. Stroud ◽  
Jeffrey W. Long ◽  
Karen E. Swider-Lyons ◽  
Debra R. Rolison
Keyword(s):  
Methanol Oxidation ◽  
Structural Heterogeneity ◽  
Oxidation Activity ◽  
Bimetallic Alloy ◽  
Transmission Electron ◽  
Chemical Segregation ◽  
High Fraction ◽  
Argon Mixture ◽  
Microscopy Techniques ◽  
Electron Energy Loss

To address how the chemical and structural heterogeneity of Pt50Ru50 nanoparticles affects methanol oxidation activity, we have employed an arsenal of transmission electron microscopy techniques (conventional bright field-imaging, selected area diffraction, atomic-resolution lattice imaging, electron-energy loss spectroscopy, and energy-dispersive x-ray spectroscopy) to characterize 2.5-nm particles in differing oxidation and hydration states. Our studies demonstrate that electrocatalysts containing a high fraction of Ru-rich hydrous oxide, as apposed to the anhydrous PtRu bimetallic alloy, have as much as 250x higher methanol oxidation activityThe nominally 2.5-nm Pt50Ru50 particles were studied in as-received, reduced and reoxidized forms. The reducing treatment consisted of 2 h at 100 °C in flowing 10% PL/argon mixture. For re-oxidation, the reduced particles were heated for 20 h at 100 °C in an H2O-saturated oxygen atmosphere. The particles were suspended in methanol, and pipetted onto holey-carboncoated Cu grids for TEM studies.

Non-adhesive lotus and other hydrophobic materials

2008 ◽  
Vol 366 (1870) ◽  
pp. 1539-1556 ◽  
Author(s):  
David Quéré ◽  
Mathilde Reyssat
Keyword(s):  
Solid Surface ◽  
Room Temperature ◽  
Water Repellency ◽  
Short Review ◽  
Water Repellent ◽  
Practical Applications ◽  
Hydrophobic Materials ◽  
Volatile Liquid ◽  
Air Cushion ◽  
The Stability

Superhydrophobic materials recently attracted a lot of attention, owing to the potential practical applications of such surfaces—they literally repel water, which hardly sticks to them, bounces off after an impact and slips on them. In this short review, we describe how water repellency arises from the presence of hydrophobic microstructures at the solid surface. A drop deposited on such a substrate can float above the textures, mimicking at room temperature what happens on very hot plates; then, a vapour layer comes between the solid and the volatile liquid, as described long ago by Leidenfrost. We present several examples of superhydrophobic materials (either natural or synthetic), and stress more particularly the stability of the air cushion—the liquid could also penetrate the textures, inducing a very different wetting state, much more sticky, due to the possibility of pinning on the numerous defects. This description allows us to discuss (in quite a preliminary way) the optimal design to be given to a solid surface to make it robustly water repellent.

scholarly journals Natural microbial polysaccharides as effective factors for modification of the catalytic properties of fungal cellobiose dehydrogenase

2021 ◽  
Author(s):  
Justyna Sulej ◽  
Magdalena Jaszek ◽  
Monika Osińska-Jaroszuk ◽  
Anna Matuszewska ◽  
Renata Bancerz ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Cellobiose Dehydrogenase ◽  
Pycnoporus Sanguineus ◽  
Practical Applications ◽  
Control Value ◽  
Electrochemical Parameters ◽  
Optimum Ph ◽  
Stabilization Effect ◽  
Fungal Polysaccharides ◽  
The Stability

AbstractPolysaccharides are biopolymers composed of simple sugars like glucose, galactose, mannose, fructose, etc. The major natural sources for the production of polysaccharides include plants and microorganisms. In the present work, four bacterial and two fungal polysaccharides (PS or EPS) were used for the modification and preservation of Pycnoporus sanguineus cellobiose dehydrogenase (CDH) activity. It was found that the presence of polysaccharide preparations clearly enhanced the stability of cellobiose dehydrogenase compared to the control value (4 °C). The highest stabilization effect was observed for CDH modified with Rh110EPS. Changes in the optimum pH in the samples of CDH incubated with the chosen polysaccharide modifiers were evidenced as well. The most significant effect was observed for Rh24EPS and Cu139PS (pH 3.5). Cyclic voltammetry used for the analysis of electrochemical parameters of modified CDH showed the highest peak values after 30 days of incubation with polysaccharides at 4 °C. In summary, natural polysaccharides seem to be an effective biotechnological tool for the modification of CDH activity to increase the possibilities of its practical applications in many fields of industry.

A Taxonomy to Aid in the Design of Complex Physical Activities for Older Adults

2017 ◽  
Vol 61 (1) ◽  
pp. 21-25
Author(s):  
Lyndsie M. Koon ◽  
Robert J. Brustad ◽  
Megan Babkes Stellino
Keyword(s):  
Physical Activity ◽  
Older Adults ◽  
Cognitive Function ◽  
Environmental Context ◽  
Physical Activities ◽  
The Body ◽  
Practical Applications ◽  
Aging Adults ◽  
The Stability ◽  
Positive Results

Physical activity participation is a non-pharmaceutical intervention that can be utilized to maintain and improve cognitive function in aging adults. Although simple physical activities yield positive results in regards to cognitive function, cognitively and motorically complex physical activities may have an even greater benefit on neuroplasticity for older adults. Commercially available products such as physical activity apps or exergames offer this population a means to engage in regular physical activity on their own. However, a taxonomy is necessary to help distinguish simpler physical activities from more complex physical activities. The taxonomy proposed in this paper carefully considers the following characteristics: the stability or transport of the body, object manipulation, intertrial variability, the environmental context and the reaction or to others. The dimensions of the taxonomy are operationally defined and practical applications are provided.

Stability characteristics of lubricating film in mill oil-film bearings

2018 ◽  
Vol 70 (1) ◽  
pp. 201-211 ◽  
Author(s):  
Jianmei Wang ◽  
Zhixiong Li ◽  
Sadoughi Mohammadkazem ◽  
Min Cai ◽  
Jianfeng Kang ◽  
...  
Keyword(s):  
Influential Factors ◽  
Film Stability ◽  
High Rotational Speed ◽  
Content Type ◽  
Oil Film ◽  
Practical Applications ◽  
Lubricating Film ◽  
Operation Conditions ◽  
Comparison Results ◽  
The Stability

Purpose The stability characteristics of an oil film directly influence the safety and service life of mill oil-film bearings. However, very limited work has been done to address the stability characteristics of mill oil-film bearings. To this end, this paper aims to investigate the stability characteristics of mill oil-film bearings through theoretical and experimental analysis. Design/methodology/approach For the first time, a special designed experiment platform was developed to investigate the stability characteristics of mill oil-film bearings. In addition, a theoretical model of lubricating film of the tested bearings was established to analyze the oil-film stability. The theoretical results were compared with the experimental results. Findings The comparison results demonstrate that the critical influential factors on the bearing stability were the eccentricity ratio and the ratio of bearing length to diameter. The mill bearing was likely to be unstable under a small load and at a high rotational speed. Practical implications The paper includes implications for suitable operation conditions in practical use of mill oil-film bearings. Originality/value This paper fulfills an identified need to investigate oil-film stability of mill bearings for practical applications.

Biquadratic Digital Phase-Compensator Design with Stability-Margin Controllability

2019 ◽  
Vol 28 (04) ◽  
pp. 1950068 ◽  
Author(s):  
Tian-Bo Deng
Keyword(s):  
Stability Margin ◽  
Transformation Method ◽  
Second Order ◽  
Approximation Accuracy ◽  
Parameter Transformation ◽  
Practical Applications ◽  
Compensator Design ◽  
Novel Method ◽  
Design Idea ◽  
The Stability

This paper proposes a novel method for the design of a recursive second-order (biquadratic) all-pass phase compensator with controllable stability margin. The design idea stems from the generalized stability triangle (GST) derived by the author for the second-order biquadratic digital filter. Based on the GST, a parameter-transformation method is proposed on the transformations of the denominator coefficients of the transfer function of the biquadratic phase compensator. The transformations convert the original denominator coefficients to other new parameters, and any values of those new parameters can guarantee that the GST condition is always satisfied. Optimizing the new parameters yields a biquadratic phase compensator that definitely meets a prespecified stability margin. That is, a biquadratic all-pass phase compensator can be designed to have an arbitrarily specified stability margin. This in turn avoids the occurrence that a recursive phase compensator may become unstable in the practical applications. Thus, the resulting biquadratic phase compensator has robust stability, which is extremely important during the practical filtering operations. A design example is given to show the stability margin guarantee as well as the approximation accuracy.

Is There a Relation Between Synchronization Stability and Bifurcation Type?

2020 ◽  
Vol 30 (08) ◽  
pp. 2050123
Author(s):  
Zahra Faghani ◽  
Zhen Wang ◽  
Fatemeh Parastesh ◽  
Sajad Jafari ◽  
Matjaž Perc
Keyword(s):  
Complex Networks ◽  
Nonlinear Dynamical Systems ◽  
General Relation ◽  
Dynamical Behavior ◽  
Stability Function ◽  
Nonlinear Dynamical ◽  
Practical Applications ◽  
Stability Functions ◽  
Stability And Bifurcation ◽  
The Stability

Synchronization in complex networks is an evergreen subject with many practical applications across the natural and social sciences. The stability of synchronization is thereby crucial for determining whether the dynamical behavior is stable or not. The master stability function is commonly used to that effect. In this paper, we study whether there is a relation between the stability of synchronization and the proximity to certain bifurcation types. We consider four different nonlinear dynamical systems, and we determine their master stability functions in dependence on key bifurcation parameters. We also calculate the corresponding bifurcation diagrams. By means of systematic comparisons, we show that, although there are some variations in the master stability functions in dependence on bifurcation proximity and type, there is in fact no general relation between synchronization stability and bifurcation type. This has important implication for the restrained generalizability of findings concerning synchronization in complex networks for one type of node dynamics to others.

scholarly journals Swine-Origin H1 Influenza Viruses Isolated from Humans Exhibit Sustained Infectivity in an Aerosol State

2019 ◽  
Vol 85 (10) ◽  
Author(s):  
Joanna A. Pulit-Penaloza ◽  
Jessica A. Belser ◽  
Terrence M. Tumpey ◽  
Taronna R. Maines
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Virus Transmission ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Aerosol State ◽  
The Stability ◽  
Higher Doses ◽  
Enhanced Stability

ABSTRACT The relative importance of influenza virus transmission via aerosols is not fully understood, but experimental data suggest that aerosol transmission may represent a critical mode of influenza virus spread among humans. Decades ago, prototypical laboratory strains of influenza were shown to persist in aerosols; however, there is a paucity of data available covering currently circulating influenza viruses, which differ significantly from their predecessors. In this study, we evaluated the longevity of influenza viruses in aerosols generated in the laboratory. We selected a panel of H1 viruses that exhibit diverse transmission profiles in the ferret model, including four human isolates of swine origin (referred to as variant) and a seasonal strain. By measuring the ratio of viral RNA to infectious virus maintained in aerosols over time, we show that influenza viruses known to transmit efficiently through the air display enhanced stability in an aerosol state for prolonged periods compared to those viruses that do not transmit as efficiently. We then assessed whether H1 influenza virus was still capable of infecting and causing disease in ferrets after being aged in suspended aerosols. Ferrets exposed to very low levels of influenza virus (≤17 PFU) in aerosols aged for 15 or 30 min became infected, with five of six ferrets shedding virus in nasal washes at titers on par with ferrets who inhaled higher doses of unaged influenza virus. We describe here an underreported characteristic of influenza viruses, stability in aerosols, and make a direct connection to the role this characteristic plays in influenza transmission. IMPORTANCE Each time a swine influenza virus transmits to a human, it provides an opportunity for the virus to acquire adaptations needed for sustained human-to-human transmission. Here, we use aerobiology techniques to test the stability of swine-origin H1 subtype viruses in aerosols and evaluate their infectivity in ferrets. Our results show that highly transmissible influenza viruses display enhanced stability in an aerosol state compared to viruses that do not transmit as efficiently. Similar to human-adapted strains, swine-origin influenza viruses are infectious in ferrets at low doses even after prolonged suspension in the air. These data underscore the risk of airborne swine-origin influenza viruses and support the need for continued surveillance and refinement of innovative laboratory methods to investigate mammalian exposure to inhaled pathogens. Determination of the molecular markers that affect the longevity of airborne influenza viruses will improve our ability to quickly identify emerging strains that present the greatest threat to public health.

scholarly journals Adsorption Behavior and Electron Structure Engineering of Pd-Based Catalysts for Acetylene Hydrochlorination

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Yaqing Cen ◽  
Yuxue Yue ◽  
Saisai Wang ◽  
Jinyue Lu ◽  
Bolin Wang ◽  
...  
Keyword(s):  
Palladium Catalysts ◽  
Influence Factor ◽  
Catalytic Performance ◽  
Electron Structure ◽  
Acetylene Hydrochlorination ◽  
Practical Applications ◽  
Highly Active ◽  
New Strategy ◽  
Function Relationship ◽  
The Stability

Adsorption and activation for substrates and the stability of Pd species in Pd-based catalysts are imperative for their wider adoption in industrial and practical applications. However, the influence factor of these aspects has remained unclear. This indicates a need to understand the various perceptions of the structure–function relationship that exists between microstructure and catalytic performance. Herein, we revisit the catalytic performance of supported-ionic-liquid-phase stabilized Pd-based catalysts with nitrogen-containing ligands as a promoter for acetylene hydrochlorination, and try to figure out their regulation. We found that the absolute value of the differential energy, |Eads(C2H2)-Eads(HCl)|, is negative correlated with the stability of palladium catalysts. These findings imply that the optimization of the electron structure provides a new strategy for designing highly active yet durable Pd-based catalysts.

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