1,453 research outputs found
Dynamic Analyses of Lymphoblast Membranes Exposed to Alpha Interferon Using Flow Cytometry and Fluorescence Recovery after Photobleaching
Interferons represent a major group of the biologic response modifiers which exert multipotent effects upon cell growth, cytodifferentiation and immune functions. Previous experimental studies with alpha interferon (IFN-) have suggested that modulation of transmembrane signaling could be a critical determinant in the bioregulatory diversity. To determine whether any initial changes at the plasma membrane would directly correlate with one or more actions of IFN-, we investigated cultures of Daudi lymphoblasts which are uniquely susceptible to growth inhibition. Complementary biophysical techniques were applied. In one approach, changes in plasma membrane ion flux were measured by flow cytometry, using a fluorescent dye indicator of membrane potential: Cells briefly exposed (5-10 min) to a DNA-recombinant IFN-2 (100 to 800 U/ml) manifested a consistent plasma membrane hyperpolarization (—60 to —90 mV) which could be blocked by ouabain. In a second approach, changes in diffusion coefficients of plasma membrane-associated macromolecules were determined by measuring the fluorescence redistribution after pulse photobleaching (FRAP): Individual plasma membrane proteins (sIgM, Leu 12 or Leu 16) were la-belled with FITC conjugated goat antibodies [F(ab\u27)2 or Fab\u27] or with phycoerythrin-B conjugated monoclonal mouse anti-bodies. Statistical comparisons of cells exposed to IFN-a2 for 10 to 30 min showed immediate 27 to 88 % increases in mean lateral diffusion rates. Mutant Daudi cells, cloned for resistance to growth inhibition showed no plasma membrane hyperpolarization with IFN-2 (up to 1000 U/ ml), and baseline lateral diffusion coefficients matched those ofIFN-2-treated, non-resistant cells. We conclude that biophysical status and responses of the plasma membrane must be closely linked to the molecular mechanisms of anti-proliferative signal transduction
Michael Balint's word trail: The ‘Ocnophil’, the ‘Philobat’ and creative dyads
In this paper, I discuss how Michael Balint arrived at the concepts of ‘ocnophil’ and ‘philobat’, which refer to two kinds of object relations. I look at the correspondence between Balint and the classical scholar David Eichholz. The two crafted these words together in a passionate exchange of letters. By recognizing the importance of creative dyads in psychoanalysis, we gain more insight into the creation of psychoanalytic knowledge beyond the frame of individual authorship. I read the collaboration between Balint and Eichholz in its historical and theoretical context, particularly in relation to the Budapest School of psychoanalysis, where intellectual collaborations had an important place. The Budapest School was Michael Balint's first home, and it shaped his epistemic and psychoanalytic style. Balint constructed his psychoanalytic theories in a spirit of openness, maintaining a commitment to conversations between psychoanalysis and other disciplines
Optimal Control of Molecular Motion Expressed Through Quantum Fluid Dynamics
A quantum fluid dynamic control formulation is presented for optimally
manipulating atomic and molecular systems. In quantum fluid dynamic the control
quantum system is expressed in terms of the probability density and the quantum
current. This choice of variables is motivated by the generally expected slowly
varying spatial-temporal dependence of the fluid dynamical variables. The
quantum fluid dynamic approach is illustrated for manipulation of the ground
electronic state dynamics of HCl induced by an external electric field.Comment: 18 pages, latex, 3 figure
An HPV-E6/E7 immunotherapy plus PD-1 checkpoint inhibition results in tumor regression and reduction in PD-L1 expression
Nontoxic N-Heterocyclic Olefin Catalyst Systems for Well-Defined Polymerization of Biocompatible Aliphatic Polycarbonates
Preliminary definitions for the sonographic features of synovitis in children
Objectives Musculoskeletal ultrasonography (US) has the potential to be an important tool in the assessment of disease activity in childhood arthritides. To assess pathology, clear definitions for synovitis need to be developed first. The aim of this study was to develop and validate these definitions through an international consensus process. Methods The decision on which US techniques to use, the components to be included in the definitions as well as the final wording were developed by 31 ultrasound experts in a consensus process. A Likert scale of 1-5 with 1 indicating complete disagreement and 5 complete agreement was used. A minimum of 80% of the experts scoring 4 or 5 was required for final approval. The definitions were then validated on 120 standardized US images of the wrist, MCP and tibiotalar joints displaying various degrees of synovitis at various ages. Results B-Mode and Doppler should be used for assessing synovitis in children. A US definition of the various components (i.e. synovial hypertrophy, effusion and Doppler signal within the synovium) was developed. The definition was validated on still images with a median of 89% (range 80-100) of participants scoring it as 4 or 5 on a Likert scale. Conclusions US definitions of synovitis and its elementary components covering the entire pediatric age range were successfully developed through a Delphi process and validated in a web-based still images exercise. These results provide the basis for the standardized US assessment of synovitis in clinical practice and research
Regression and the Maternal in the History of Psychoanalysis, 1900-1957
This paper examines the history of the concept of ‘regression’ as it was perceived by Sandor Ferenczi and some of his followers in the first half of the twentieth century. The first part provides a short history of the notion of ‘regression’ from the late nineteenth century to Ferenczi's work in the 1920s and 1930s. The second and third parts of the paper focus on two other thinkers on regression, who worked in Britain, under the influence of the Ferenczian paradigm – the interwar Scottish psychiatrist, Ian D. Suttie; and the British-Hungarian psychoanalyst, and Ferenczi's most important pupil, Michael Balint. Rather than a descriptive term which comes to designate a pathological mental stage, Ferenczi understood ‘regression’ as a much more literal phenomenon. For him, the mental desire to go backwards in time is a universal one, and a consequence of an inevitable traumatic separation from the mother in early childhood, which has some deep personal and cultural implications. The paper aims to show some close affinities between the preoccupation of some psychoanalysts with ‘regression’, and the growing interest in social and cultural aspects of ‘motherhood’ and ‘the maternal role’ in mid-twentieth-century British society
Educational recommendations for the conduct, content and format of EULAR musculoskeletal ultrasound Teaching the Teachers Courses
To produce educational guidelines for the conduct, content and format of theoretical and practical teaching at EULAR musculoskeletal ultrasound (MSUS) Teaching the Teachers (TTT) Courses
Billiards with polynomial mixing rates
While many dynamical systems of mechanical origin, in particular billiards,
are strongly chaotic -- enjoy exponential mixing, the rates of mixing in many
other models are slow (algebraic, or polynomial). The dynamics in the latter
are intermittent between regular and chaotic, which makes them particularly
interesting in physical studies. However, mathematical methods for the analysis
of systems with slow mixing rates were developed just recently and are still
difficult to apply to realistic models. Here we reduce those methods to a
practical scheme that allows us to obtain a nearly optimal bound on mixing
rates. We demonstrate how the method works by applying it to several classes of
chaotic billiards with slow mixing as well as discuss a few examples where the
method, in its present form, fails.Comment: 39pages, 11 figue
Optimized pulses for the control of uncertain qubits
Constructing high-fidelity control fields that are robust to control, system,
and/or surrounding environment uncertainties is a crucial objective for quantum
information processing. Using the two-state Landau-Zener model for illustrative
simulations of a controlled qubit, we generate optimal controls for \pi/2- and
\pi-pulses, and investigate their inherent robustness to uncertainty in the
magnitude of the drift Hamiltonian. Next, we construct a quantum-control
protocol to improve system-drift robustness by combining environment-decoupling
pulse criteria and optimal control theory for unitary operations. By
perturbatively expanding the unitary time-evolution operator for an open
quantum system, previous analysis of environment-decoupling control pulses has
calculated explicit control-field criteria to suppress environment-induced
errors up to (but not including) third order from \pi/2- and \pi-pulses. We
systematically integrate this criteria with optimal control theory,
incorporating an estimate of the uncertain parameter, to produce improvements
in gate fidelity and robustness, demonstrated via a numerical example based on
double quantum dot qubits. For the qubit model used in this work, post facto
analysis of the resulting controls suggests that realistic control-field
fluctuations and noise may contribute just as significantly to gate errors as
system and environment fluctuations.Comment: 38 pages, 15 figures, RevTeX 4.1, minor modifications to the previous
versio
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