169,769 research outputs found
Strong light-matter coupling: from atoms to solid state systems
No full textThe physics of strong light-matter coupling has been addressed in different scientific communities over the last three decades. Since the early eighties, atoms coupled to optical and microwave cavities have led to pioneering demonstrations of cavity quantum electrodynamics, Gedanken experiments, and building blocks for quantum information processing, for which the Nobel Prize in Physics was awarded in 2012. In the framework of semiconducting devices, strong coupling has allowed investigations into the physics of Bose gases in solid-state environments, and the latter holds promise for exploiting light-matter interaction at the single-photon level in scalable architectures. More recently, impressive developments in the so-called superconducting circuit QED have opened another fundamental playground to revisit cavity quantum electrodynamics for practical and fundamental purposes.
This book aims at developing the necessary interface between these communities, by providing future researchers with a robust conceptual, theoretical and experimental basis on strong light-matter coupling, both in the classical and in the quantum regimes. In addition, the emphasis is on new forefront research topics currently developed around the physics of strong light-matter interaction in the atomic and solid-state scenarios
Flow-FISH evaluation of telomere length in Philadelphia-negative myeloproliferative neoplasms.
No full textWe analyzed telomere lenght in a cohort of MPN patients in order to investigate its relationship with biological and clinical parameters. Patients with MPN present shortened telomeres irrespective of their JAK2 or MPL mutational status, implying that different molecular mechanisms may affect stem cells in the same way, and suggest that telomere assessment may be of potential diagnostic value in the work up of suspected MPN
Influence of the phonon-exciton interaction on the exciton-exciton quantum correlation in semiconductor microcavities
No full textWe present an extension of the previous descriptions based on the Dynamics Controlled Truncation Scheme of light-matter interaction beyond mean-field, including the microscopic description of the exciton-photon interaction. This enables the microscopic analysis of the influence of decoherence and noise on the polariton quantum correlations originating from nonlinear optical processes. We expand the operators involved in the dynamics in terms of exact eigenstates of the electron system, the photon and phonon operators and treat phonon-assisted transitions within the Markov approximation. In particular, we present quantum Heisenberg-Langevin equations describing light-induced excitations in semiconductor systems interacting with the phonon bath. This theoretical framework is applied to study the influence of dephasing and noise due to photoluminescence on polariton quantum correlations generated by parametric emission in microcavities
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Modulation of Amnionic Adenylate Cyclase and cAMP Phosphodiesterase by Prostaglandins E(1) and F2α
No full textThe action of prostaglandins E1 and F2αon adenylate cyclas and cAMP phos-phodiesterase was assayed in cell membrane fractions of amnion obtained before and after labor from term physiological pregnancies. Both prostaglandins stimulate the activity of adenylate cyclase in a dose-dependent manner. After spontaneous delivery both prostaglandins stimulatethe activity of phosphodiesterase at lower doses and inhibit it at higher ones while the stimulatory effect of low doses is missing before labor. Such a behavior could represent a mechanism for the preservation of the cAMP-mediated processes throughout the entire event of delivery. © 1994 S. Karger AG, Basel.The action of prostaglandins E 1 and F(2α), on adenylate cyclase and cAMP phosphodiesterase was assayed in cell membrane fractions of amnion obtained before and after labor from term physiological pregnancies. Both prostaglandins stimulate the activity of adenylate cyclase in a dose-dependent manner. After spontaneous delivery both prostaglandins stimulate the activity of phosphodiesterase at lower doses and inhibit it at higher ones while the stimulatory effect of low doses is missing before labor. Such a behavior could represent a mechanism for the preservation of the cAMP-mediated processes throughout the entire event of delivery
The Use of Physical Restraints in Italian Intensive Care Units: Results From a Multicenter Observational Study
No full textBackground: The use of physical restraints (PRs) varies across countries and clinical settings, with intensive care units having the highest frequency. Although many investigations on the use of PRs have been conducted worldwide, few studies are reported in the Italian context. Objectives: The aims of this study were to describe PR rates and types and to observe the factors associated with PR use. Methods: In this observational study, 2 methods were used to collect data: direct observation and review of patients' documentations. Results: We performed 328 observations on 146 critically ill patients. Physical restraints were applied in 56.7% (n = 186) of these observations. Bilateral wrist ties were used for most PR episodes (n = 135, 72.6%), followed by unilateral wrist ties (12.9%). The most documented reasons were preventing patients from self-extubation (n = 93, 50.0%) and preserving indwelling lines and tubes (n = 60, 32. 2%). In the multivariate logistic regression analysis, patients who were cared for during the night shift were almost 4 times more likely to be restrained than patients in the morning shifts (odds ratio, 3.84; P =.001) and patients with endotracheal tube were 3.5 times more likely to be restricted than spontaneously breathing patients (odds ratio, 3.59; P <.001). Discussions: Physical restraints are commonly used among critically ill patients in Italian intensive care units. There is a need to share the metrics for an efficient and accurate measurement of PR usage and trends and to document the reason for restraints, type of restraints, timeframe, and decision-making criteria
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
High prevalence of isolated tumor cells (ITC) in regional lymph nodes from PN0 colorectal cancer
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