We investigate the conditions yielding plasmon-exciton strong coupling at the single emitter level in the gap between two metal nanoparticles. Inspired by transformation optics ideas, a ...quasianalytical approach is developed that makes possible a thorough exploration of this hybrid system incorporating the full richness of its plasmonic spectrum. This allows us to reveal that by placing the emitter away from the cavity center, its coupling to multipolar dark modes of both even and odd parity increases remarkably. This way, reversible dynamics in the population of the quantum emitter takes place in feasible implementations of this archetypal nanocavity.
We demonstrate in this work that the use of metasurfaces provides a viable strategy to largely tune and enhance near-field radiative heat transfer between extended structures. In particular, using a ...rigorous coupled wave analysis, we predict that Si-based metasurfaces featuring two-dimensional periodic arrays of holes can exhibit a room-temperature near-field radiative heat conductance much larger than any unstructured material to date. We show that this enhancement, which takes place in a broad range of separations, relies on the possibility to largely tune the properties of the surface plasmon polaritons that dominate the radiative heat transfer in the near-field regime.
Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, ...extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange
Λ
baryons, selected from weak decays of charm baryons produced in
p
p
collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of
C
P
T
symmetry can be performed by measuring the magnetic dipole moment of
Λ
and
Λ
¯
baryons. For short-lived
Λ
c
+
and
Ξ
c
+
baryons, to be produced in a fixed-target experiment using the 7
TeV
LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We investigate the interplay between quenching and strong coupling in systems that include a collection of quantum emitters interacting with a metal nanoparticle. By using detailed numerical ...simulations and analytical modeling, we demonstrate that quantum emitters can exhibit strong coupling with the particle dipole resonance at distances at which the quenching to nonradiative channels is expected to dominate the dynamics. These results can be accounted for in terms of the pseudomode character of the higher multipole modes of the nanoparticle and the corresponding reduction of the induced loss rate. These findings expand the current understanding of light-matter interaction in plasmonic systems and could contribute to the development of novel quantum plasmonic platforms.
Metamaterials are artificial materials with subwavelength structure that enable the translation of magnetic and electric responses into spectral regions not accessible through naturally occurring ...materials. Here, we report direct measurements of the propagation and confinement of terahertz electromagnetic surface modes tightly bound to flat plasmonic metamaterials that consist of metal surfaces decorated with two-dimensional arrays of subwavelength-periodicity pits. These modes are surface plasmon polaritons with an effective plasma frequency controlled entirely by the surface geometry. The mode spectrum and penetration depth into air demonstrate strong wavelength-scale energy confinement to the surface below the electromagnetic band edge; this is in stark contrast to the very weak confinement found at flat metal surfaces in this spectral regime. The results are in good agreement with analytical and numerical models of surface plasmon polaritons propagating on structured perfect-conductor surfaces, and imply that plasmonic metamaterials could help miniaturize optical components or lead to improved chemical or biochemical sensors.
Objective To evaluate the effects of intraoperative protective ventilation on major postoperative respiratory complications and to define safe intraoperative mechanical ventilator settings that do ...not translate into an increased risk of postoperative respiratory complications.Design Hospital based registry study.Setting Academic tertiary care hospital and two affiliated community hospitals in Massachusetts, United States.Participants 69 265 consecutively enrolled patients over the age of 18 who underwent a non-cardiac surgical procedure between January 2007 and August 2014 and required general anesthesia with endotracheal intubation.Interventions Protective ventilation, defined as a median positive end expiratory pressure (PEEP) of 5 cmH2O or more, a median tidal volume of less than 10 mL/kg of predicted body weight, and a median plateau pressure of less than 30 cmH2O.Main outcome measure Composite outcome of major respiratory complications, including pulmonary edema, respiratory failure, pneumonia, and re-intubation.Results Of the 69 265 enrolled patients 34 800 (50.2%) received protective ventilation and 34 465 (49.8%) received non-protective ventilation intraoperatively. Protective ventilation was associated with a decreased risk of postoperative respiratory complications in multivariable regression (adjusted odds ratio 0.90, 95% confidence interval 0.82 to 0.98, P=0.013). The results were similar in the propensity score matched cohort (odds ratio 0.89, 95% confidence interval 0.83 to 0.97, P=0.004). A PEEP of 5 cmH2O and median plateau pressures of 16 cmH2O or less were associated with the lowest risk of postoperative respiratory complications.Conclusions Intraoperative protective ventilation was associated with a decreased risk of postoperative respiratory complications. A PEEP of 5 cmH2O and a plateau pressure of 16 cmH2O or less were identified as protective mechanical ventilator settings. These findings suggest that protective thresholds differ for intraoperative ventilation in patients with normal lungs compared with those used for patients with acute lung injury.
The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after ...surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.
Nutrition, osteoarthritis and cartilage metabolism Messina, Osvaldo Daniel; Vidal Wilman, Maritza; Vidal Neira, Luis F.
Aging clinical and experimental research,
06/2019, Letnik:
31, Številka:
6
Journal Article
Recenzirano
Background
Osteoarthritis (OA) is a degenerative joint disease and a leading cause of adult disability. There is no cure for OA and there is no effective treatment to stop its progression. Current ...pharmacologic treatments such as analgesics and non-steroidal anti-inflammatory drugs may improve the pain and offer some relief but they do not affect the progression of the disease. The chronic intake of these drugs may result in severe adverse events. The aim of this review is to revise the effects of nutrition on cartilage metabolism and OA progression.
Methods
A systematic literature search was performed including those related to macro- and micro-nutrients’ actions on cartilage and OA outcome. We selected peer-reviewed articles reporting the results of human clinical trials.
Results
Glucosamine and chondroitin sulfate have shown to delay OA knee progression in several clinical trials. The effectiveness of some products considered nutraceuticals has been widely reviewed in the literature. This article presents a general description of the effectiveness and mechanism of action of nutrients, vitamins, antioxidants and other natural components considered as part of the normal diet. Many in vitro studies indicate the efficacy of specific nutrients in cartilage metabolism and its involvement in OA. However, rigorous clinical studies needed to evaluate the efficacy of these compounds in humans are still missing. The influence of nutrients and diet on the metabolism of cartilage and OA could represent a long-term coadjuvant alternative in the management of patients with OA. Effects of diet modifications on lipid and cholesterol profiles, adequate vitamin levels and weight reduction in obese patients could influence the course of the disease.
Conclusion
This review demonstrates that nutrition can improve the symptoms of OA. Glucosamine and chondroitin sulfate have shown robustly to delay the progression of knee OA in several well-designed studies, however more controlled clinical trials are needed to conclude that nutritional changes slow down the progression of the disease.
We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled ...particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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