145 research outputs found
Ultrafast Plasmonic Control of Second Harmonic Generation
Efficient frequency conversion techniques are crucial to the development of
plasmonic metasurfaces for information processing and signal modulation. In
principle, nanoscale electric-field confinement in nonlinear materials enables
higher harmonic conversion efficiencies per unit volume than those attainable
in bulk materials. Here we demonstrate efficient second-harmonic generation
(SHG) in a serrated nanogap plasmonic geometry that generates steep electric
field gradients on a dielectric metasurface. An ultrafast pump is used to
control plasmon-induced electric fields in a thin-film material with inversion
symmetry that, without plasmonic enhancement, does not exhibit an an even-order
nonlinear optical response. The temporal evolution of the plasmonic near-field
is characterized with ~100as resolution using a novel nonlinear interferometric
technique. The ability to manipulate nonlinear signals in a metamaterial
geometry as demonstrated here is indispensable both to understanding the
ultrafast nonlinear response of nanoscale materials, and to producing active,
optically reconfigurable plasmonic device
CONCEPTUAL MODEL OF DEVELOPMENT OF FINANCIAL STRATEGY OF THE ENTERPRISES IN MODERN ECONOMIC CONDITIONS
The conceptual model of formation of financial strategy of a sustainable development of the enterprise is developed. Main units of model provide implementation of long-term economic targets, carrying out diagnostics of current state and size of resource potential in the future, optimization of structure of the capital, planning of financial activity, realization of the corresponding complex of actions
CONCEPTUAL MODEL OF DEVELOPMENT OF FINANCIAL STRATEGY OF THE ENTERPRISES IN MODERN ECONOMIC CONDITIONS
The conceptual model of formation of financial strategy of a sustainable development of the enterprise is developed. Main units of model provide implementation of long-term economic targets, carrying out diagnostics of current state and size of resource potential in the future, optimization of structure of the capital, planning of financial activity, realization of the corresponding complex of actions
RESEARCH OF FEATURES OF DECREASE IN RISK AND UNCERTAINTY OF INNOVATIVE ACTIVITY OF THE INDUSTRIAL ENTERPRISE
The mechanism of decrease in uncertainty and risk of innovative activity of the industrial enterprise is offered. On the basis of the established dependences of change of risk level on stages of innovative process effective management of adaptation of innovative processes can be carried out by a certain type of risk, and in that period when this type of risk poses the greatest threat to all innovative process
RESEARCH OF FEATURES OF DECREASE IN RISK AND UNCERTAINTY OF INNOVATIVE ACTIVITY OF THE INDUSTRIAL ENTERPRISE
The mechanism of decrease in uncertainty and risk of innovative activity of the industrial enterprise is offered. On the basis of the established dependences of change of risk level on stages of innovative process effective management of adaptation of innovative processes can be carried out by a certain type of risk, and in that period when this type of risk poses the greatest threat to all innovative process
Aggregation and retention of human urokinase type plasminogen activator in the yeast endoplasmic reticulum
BACKGROUND: Secretion of recombinant proteins in yeast can be affected by their improper folding in the endoplasmic reticulum and subsequent elimination of the misfolded molecules via the endoplasmic reticulum associated protein degradation pathway. Recombinant proteins can also be degraded by the vacuolar protease complex. Human urokinase type plasminogen activator (uPA) is poorly secreted by yeast but the mechanisms interfering with its secretion are largely unknown. RESULTS: We show that in Hansenula polymorpha overexpression worsens uPA secretion and stimulates its intracellular aggregation. The absence of the Golgi modifications in accumulated uPA suggests that aggregation occurs within the endoplasmic reticulum. Deletion analysis has shown that the N-terminal domains were responsible for poor uPA secretion and propensity to aggregate. Mutation abolishing N-glycosylation decreased the efficiency of uPA secretion and increased its aggregation degree. Retention of uPA in the endoplasmic reticulum stimulates its aggregation. CONCLUSIONS: The data obtained demonstrate that defect of uPA secretion in yeast is related to its retention in the endoplasmic reticulum. Accumulation of uPA within the endoplasmic reticulum disturbs its proper folding and leads to formation of high molecular weight aggregates
Spatial Correlation of Conduction Electrons in Metal with Complicated Geometry Of The Fermi Surface
The "density-density" correlation function of conduction electrons in metal
is investigated. It is shown, that the asymptotic behaviour of the CF depends
on the shape and the local geometry of the Fermi surface. In particular, the
exponent of power law which describes the damping of Friedel oscillations at
large r (-4 for an isotropic Fermi gas) is determined by local geometry of the
FS. The applications of the obtained results to calculations of the CF in a
metal near the electron topological transition and of the RKKY exchange
integral are considered as well.Comment: 12 pages, LaTeX, 5 figures upon request (to appear in J.Phys.:CM,
1993
Cyclone: an accessible pipeline to analyze, evaluate, and optimize multiparametric cytometry data
In the past decade, high-dimensional single-cell technologies have revolutionized basic and translational immunology research and are now a key element of the toolbox used by scientists to study the immune system. However, analysis of the data generated by these approaches often requires clustering algorithms and dimensionality reduction representation, which are computationally intense and difficult to evaluate and optimize. Here, we present Cytometry Clustering Optimization and Evaluation (Cyclone), an analysis pipeline integrating dimensionality reduction, clustering, evaluation, and optimization of clustering resolution, and downstream visualization tools facilitating the analysis of a wide range of cytometry data. We benchmarked and validated Cyclone on mass cytometry (CyTOF), full-spectrum fluorescence-based cytometry, and multiplexed immunofluorescence (IF) in a variety of biological contexts, including infectious diseases and cancer. In each instance, Cyclone not only recapitulates gold standard immune cell identification but also enables the unsupervised identification of lymphocytes and mononuclear phagocyte subsets that are associated with distinct biological features. Altogether, the Cyclone pipeline is a versatile and accessible pipeline for performing, optimizing, and evaluating clustering on a variety of cytometry datasets, which will further power immunology research and provide a scaffold for biological discovery
[PSI+] Maintenance Is Dependent on the Composition, Not Primary Sequence, of the Oligopeptide Repeat Domain
[PSI+], the prion form of the yeast Sup35 protein, results from the structural conversion of Sup35 from a soluble form into an infectious amyloid form. The infectivity of prions is thought to result from chaperone-dependent fiber cleavage that breaks large prion fibers into smaller, inheritable propagons. Like the mammalian prion protein PrP, Sup35 contains an oligopeptide repeat domain. Deletion analysis indicates that the oligopeptide repeat domain is critical for [PSI+] propagation, while a distinct region of the prion domain is responsible for prion nucleation. The PrP oligopeptide repeat domain can substitute for the Sup35 oligopeptide repeat domain in supporting [PSI+] propagation, suggesting a common role for repeats in supporting prion maintenance. However, randomizing the order of the amino acids in the Sup35 prion domain does not block prion formation or propagation, suggesting that amino acid composition is the primary determinant of Sup35's prion propensity. Thus, it is unclear what role the oligopeptide repeats play in [PSI+] propagation: the repeats could simply act as a non-specific spacer separating the prion nucleation domain from the rest of the protein; the repeats could contain specific compositional elements that promote prion propagation; or the repeats, while not essential for prion propagation, might explain some unique features of [PSI+]. Here, we test these three hypotheses and show that the ability of the Sup35 and PrP repeats to support [PSI+] propagation stems from their amino acid composition, not their primary sequences. Furthermore, we demonstrate that compositional requirements for the repeat domain are distinct from those of the nucleation domain, indicating that prion nucleation and propagation are driven by distinct compositional features
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