993 research outputs found
All Optical Switch of Vacuum Rabi Oscillations: The Ultrafast Quantum Eraser
We study the all-optical time-control of the strong coupling between a single
cascade three-level quantum emitter and a microcavity. We find that only
specific arrival-times of the control pulses succeed in switching-off the Rabi
oscillations. Depending on the arrival times of control pulses, a variety of
exotic non-adiabatic cavity quantum electrodynamics effects can be observed. We
show that only control pulses with specific arrival times are able to suddenly
switch-off and -on first-order coherence of cavity photons, without affecting
their strong coupling population dynamics. Such behavior may be understood as a
manifestation of quantum complementarity
Towards formal models and languages for verifiable Multi-Robot Systems
Incorrect operations of a Multi-Robot System (MRS) may not only lead to
unsatisfactory results, but can also cause economic losses and threats to
safety. These threats may not always be apparent, since they may arise as
unforeseen consequences of the interactions between elements of the system.
This call for tools and techniques that can help in providing guarantees about
MRSs behaviour. We think that, whenever possible, these guarantees should be
backed up by formal proofs to complement traditional approaches based on
testing and simulation.
We believe that tailored linguistic support to specify MRSs is a major step
towards this goal. In particular, reducing the gap between typical features of
an MRS and the level of abstraction of the linguistic primitives would simplify
both the specification of these systems and the verification of their
properties. In this work, we review different agent-oriented languages and
their features; we then consider a selection of case studies of interest and
implement them useing the surveyed languages. We also evaluate and compare
effectiveness of the proposed solution, considering, in particular, easiness of
expressing non-trivial behaviour.Comment: Changed formattin
Total or near-total thyroidectomy versus subtotal thyroidectomy for multinodular non-toxic goitre in adults
Background
Total thyroidectomy (TT) and subtotal thyroidectomy (ST) are worldwide treatment options for multinodular non-toxic goitre in adults. Near TT, defined as a postoperative thyroid remnant less than 1 mL, is supposed to be a similarly effective but safer option than TT. ST has been shown to be marginally safer than TT, but it may leave an undetected thyroid cancer in place.
Objectives
The objective was to assess the effects of total or near-total thyroidectomy compared to subtotal thyroidectomy for multinodular non-toxic goitre.
Search methods
We searched the Cochrane Library, MEDLINE, PubMed, EMBASE, as well as the ICTRP Search Portal and ClinicalTrials.gov. The date of the last search was 18 June 2015 for all databases. No language restrictions were applied.
Selection criteria
Two review authors independently scanned the abstract, title or both sections of every record retrieved to identify randomised controlled trials (RCTs) on thyroidectomy for multinodular non-toxic goitre for further assessment.
Data collection and analysis
Two review authors independently extracted data, assessed studies for risk of bias and evaluated overall study quality utilising the GRADE instrument. We calculated the odds ratio (OR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. A random-effects model was used for pooling data.
Main results
We examined 1430 records, scrutinized 14 full-text publications and included four RCTs. Altogether 1305 participants entered the four trials, 543 participants were randomised to TT and 762 participants to ST. A total of 98% and 97% of participants finished the trials in the TT and ST groups, respectively. Two trials had a duration of follow-up between 12 and 39 months and two trials a follow-up of 5 and 10 years, respectively. Risk of bias across studies was mainly unknown for selection, performance and detection bias. Attrition bias was generally low and reporting bias high for some outcomes. In the short-term postoperative period no deaths were reported for both TT and ST groups. However, longer-term data on all-cause mortality were not reported (1284 participants; 4 trials; moderate quality evidence). Goiter recurrence was lower in the TT group compared to ST. Goiters recurred in 0.2% (1/425) of the TT group compared to 8.4% (53/632) of the ST group (OR 0.05 (95% CI 0.01 to 0.21); P < 0.0001; 1057 participants; 3 trials; moderate quality evidence). Re-intervention due to goitre recurrence was lower in the TT group compared to ST. Re-intervention was necessary in 0.5% (1/191) of TT patients compared to 0.8% (3/379)of ST patients (OR 0.66 (95% CI 0.07 to 6.38); P = 0.72; 570 participants; 1 trial; low quality evidence). The incidence of permanent recurrent laryngeal nerve palsy was lower for ST compared with TT. Permanent recurrent laryngeal nerve palsy occurred in 0.8% (6/741) of ST patients compared to 0.7% (4/543) of TT patients (OR 1.28, (95% CI 0.38 to 4.36); P = 0.69; 1275 participants; 4 trials; low quality evidence). The incidence of permanent hypoparathyroidism was lower for ST compared with TT. Permanent hypoparathyroidism occurred in 0.1% (1/741) of ST patients compared to 0.6% (3/543) of TT patients (OR 3.09 (95% CI 0.45 to 21.36); P = 0.25; 1275 participants: 4 trials; low quality evidence). The incidence of thyroid cancer was lower for ST compared with TT. Thyroid cancer occurred in 6.1% (41/669) of ST patients compared to 7.3% (34/465)of TT patients (OR 1.32 (95% CI 0.81 to 2.15); P = 0.27; 1134 participants; 3 trials; low quality evidence). No data on health-related quality of life or socioeconomic effects were reported in the included studies.
Authors' conclusions
The body of evidence on TT compared with ST is limited. Goiter recurrence is reduced following TT. The effects on other key outcomes such as re-interventions due to goitre recurrence, adverse events and thyroid cancer incidence are uncertain. New long-term RCTs with additional data such as surgeons level of experience, treatment volume of surgical centres and details on techniques used are needed
Rhythm outcomes of minimally-invasive off-pump surgical versus catheter ablation in atrial fibrillation: A meta-analysis of reconstructed time-to-event data
Background: Mid- and long-term rhythm outcomes of catheter ablation (CA) for atrial fibrillation (AF) are reported to be suboptimal. Minimally invasive surgical off-pump ablation (MISOA), including both thoracoscopic and trans-diaphragmatic approaches, has been developed to reduce surgical invasiveness and overcome on-pump surgery drawbacks. We sought to compare the efficacy and safety of MISOA and CA for AF treatment. Methods: A systematic review and meta-analysis of the literature was performed including studies comparing MISOA and CA. The primary endpoint was survival freedom from AF at follow-up after a 3-month blanking period. Subgroup analysis of the primary endpoint was performed according to the type of surgical incision and hybrid approach. Results: Freedom from AF at 4 years was 52.1% ± 3.2% vs 29.1% ± 3.5%, between MISOA and CA respectively (log-rank p < 0.001; Hazard Ratio: 0.60 [95%Confidence Interval (CI):0.50-0.72], p < 0.001). At landmark analysis, a significant improvement in rhythm outcomes was observed in the MISOA group after the 5th month of follow-up (2 months from the blanking period). The Odds Ratio between MISOA and CA of postoperative cerebrovascular accident incidence and postoperative permanent pacemaker implant (PPM) were 2.00 (95%CI:0.91-4.40, p = 0.084) and 1.55 (95%CI:0.61-3.95, p = 0.358), respectively. The incidence rate ratio of late CVA between MISOA and CA was 0.86 (95%CI:0.28-2.65, p = 0.787), while for late PPM implant was 0.45 (95%CI:0.11-1.78, p = 0.256). Conclusions: The current meta-analysis suggests that MISOA provides superior rhythm outcomes when compared to CA in terms of sinus rhythm restoration. Despite the rhythm outcome superiority of MISOA, it is associated to higher postoperative complications compared to CA
How to Turn an Electron Transfer Protein into a Redox Enzyme for Biosensing
Cytochrome c is a small globular protein whose main physiological role is to shuttle electrons within the mitochondrial electron transport chain. This protein has been widely investigated, especially as a paradigmatic system for understanding the fundamental aspects of biological electron transfer and protein folding. Nevertheless, cytochrome c can also be endowed with a non-native catalytic activity and be immobilized on an electrode surface for the development of third generation biosensors. Here, an overview is offered of the most significant examples of such a functional transformation, carried out by either point mutation(s) or controlled unfolding. The latter can be induced chemically or upon protein immobilization on hydrophobic self-assembled monolayers. We critically discuss the potential held by these systems as core constituents of amperometric biosensors, along with the issues that need to be addressed to optimize their applicability and response
Management of patients with lymphoma and COVID-19: Narrative review and evidence-based practical recommendations
Patients with hematologic malignancies can be immunocompromized because of their disease, anti-cancer therapy, and concomitant immunosuppressive treatment. Furthermore, these patients are usually older than 60 years and have comorbidities. For all these reasons they are highly vulnerable to infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and have an increased risk of developing severe/critical Coronavirus disease 2019 (COVID-19) compared to the general population. Although COVID-19 vaccination has proven effective in reducing the incidence of severe/critical disease, vaccinated patients with lymphoma may not be protected as they often fail to develop a sufficient antiviral immune response. There is therefore an urgent need to address the management of patients with lymphoma and COVID-19 in the setting of the ongoing pandemic. Passive immunization with monoclonal antibodies against SARS-CoV-2 is a currently available complementary drug strategy to active vaccination for lymphoma patients, while monoclonal antibodies and antiviral drugs (remdesivir, ritonavir-boosted nirmatrelvir, and molnupiravir) have proven effective in preventing the progression to severe/critical COVID-19. In this narrative review we present the most recent data documenting the characteristics and outcomes of patients with concomitant lymphoma and COVID-19. Our ultimate goal is to provide practice-oriented guidance in the management of these vulnerable patients from diagnosis to treatment and follow-up of lymphoma. To this purpose, we will first provide an overview of the main data concerning prognostic factors and fatality rate of lymphoma patients who develop COVID-19; the outcomes of COVID-19 vaccination will also be addressed. We will then discuss current COVID-19 prophylaxis and treatment options for lymphoma patients. Finally, based on the literature and our multidisciplinary experience, we will summarize a set of indications on how to manage patients with lymphoma according to COVID-19 exposure, level of disease severity and former history of infection, as typically encountered in clinical practice
Mitral valve surgery in acute infective endocarditis: long-term outcomes of mitral valve repair versus replacement
AimsTiming and surgical strategies in acute infective endocarditis are still questionable. We sought to investigate clinical outcomes of patients undergoing mitral valve repair (MVR) compared with mitral valve replacement [mitral valve prosthesis (MVP)] for acute infective endocarditis.MethodsFrom 2004 to 2019, 109 consecutive patients with acute mitral valve infective endocarditis were retrospectively investigated. Patients were divided into two groups according to surgical strategy: MVR 53/109 (48.6%) versus MVP 56/109 (51.4%). Primary end points were in-hospital mortality and overall survival at 10 years. Secondary end point was the freedom from infective endocarditis relapse.ResultsOur institutional surgical approach for infective endocarditis allowed us to achieve MVR in 48.6% of patients. Hospital mortality was comparable between the two groups [MVR: 1/53 (1.9%) versus MVP: 2/56 (3.6%), P = 1.000]. Overall 10-year survival was 80.0 +/- 14.1 and 77.2 +/- 13.5% for MVR and MVP, respectively (P = 0.648). MVR showed a lower incidence of infective endocarditis relapse compared with MVP (MVR: 93.6 +/- 7.1 versus MVP: 80.9 +/- 10.8%, P = 0.041). At Cox regression, infective endocarditis relapse was an independent risk factor for death (hazard ratio 4.03; 95% confidence interval 1.41-11.52; P = 0.009).ConclusionThe tendency to postpone surgery in stable patients with mitral infective endocarditis allowed achievement of MVR in almost 50% of patients. Although repair remains the approach of choice in our institution, no differences between MVR and MVP were reported in terms of early/late survival. However, MVP had a higher incidence of infective endocarditis relapse that represents an independent risk of mortality
Cr(III) Complexes Bearing a β-Ketoimine Ligand for Olefin Polymerization: Are There Differences between Coordinative and Covalent Bonding?
β-ketoimines are extensively applied for the synthesis of organometallic complexes intended as (pre)catalysts for a variety of chemical transformations. We were interested in the synthesis of two Cr complexes bearing a simple bidentate β-ketoimine (L), with different ligand binding modes, as well as their application as a precatalyst in the polymerization of olefins. Complex 1 (L2CrCl3) was obtained by direct reaction of L with CrCl3(THF)3, while, for the synthesis of complex 2 (LCrCl2), the ligand was first deprotonated with nBuLi, giving the β-ketoiminato ligand L─Li+, and then reacted with CrCl3(THF)3. Characterization of the complexes proved that the Cr(III) ion is coordinatively bonded to L in 1, while it is covalently bonded to L in 2. The complexes were then used as precatalysts for the polymerization of ethylene and various cyclic olefins. Upon activation with methylaluminoxane, both the complexes exhibited poor activity in the polymerization of ethylene, whilst they exhibit good productivity in the polymerization of cyclic olefins, affording semicrystalline oligomers, without a significant difference between 1 and 2. To gain more insight, we investigated the reaction of the complexes with the Al-cocatalyst by IR and UV-Vis spectroscopies. The results proved that, in case of 1, the Al-activator deprotonates the ligand, bringing to the formation of an active species analogous to that of 2
Adsorbing surface strongly influences the pseudoperoxidase and nitrite reductase activity of electrode-bound yeast cytochrome c. The effect of hydrophobic immobilization
The Met80Ala and Met80Ala/Tyr67Ala variants of S. cerevisiae iso-1 cytochrome c (ycc) and their adducts with cardiolipin immobilized onto a gold electrode coated with a hydrophobic self-assembled monolayer (SAM) of decane-1-thiol were studied through cyclic voltammetry and surface-enhanced resonance Raman spectroscopy (SERRS). The electroactive species - containing a six-coordinate His/His axially ligated heme and a five-coordinate His/- heme stable in the oxidized and reduced state, respectively - and the pseudoperoxidase activity match those found previously for the wt species and are only slightly affected by CL binding. Most importantly, the reduced His/- ligated form of these variants is able to catalytically reduce the nitrite ion, while electrode-immobilized wt ycc and other His/Met heme ligated variants under a variety of conditions are not. Besides the pseudoperoxidase and nitrite reductase functions, which are the most physiologically relevant abilities of these constructs, also axial heme ligation and the equilibria between conformers are strongly affected by the nature - hydrophobic vs. electrostatic - of the non-covalent interactions determining protein immobilization. Also affected are the catalytic activity changes induced by a given mutation as well as those due to partial unfolding due to CL binding. It follows that under the same solution conditions the structural and functional properties of immobilized ycc are surface-specific and therefore cannot be transferred from an immobilized system to another involving different interfacial protein-SAM interactions
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