The biaxial van der Waals semiconductor α‐phase molybdenum trioxide (α‐MoO3) has recently received significant attention due to its ability to support highly anisotropic phonon polaritons ...(PhPs)—infrared (IR) light coupled to lattice vibrations—offering an unprecedented platform for controlling the flow of energy at the nanoscale. However, to fully exploit the extraordinary IR response of this material, an accurate dielectric function is required. Here, the accurate IR dielectric function of α‐MoO3 is reported by modeling far‐field polarized IR reflectance spectra acquired on a single thick flake of this material. Unique to this work, the far‐field model is refined by contrasting the experimental dispersion and damping of PhPs, revealed by polariton interferometry using scattering‐type scanning near‐field optical microscopy (s‐SNOM) on thin flakes of α‐MoO3, with analytical and transfer‐matrix calculations, as well as full‐wave simulations. Through these correlative efforts, exceptional quantitative agreement is attained to both far‐ and near‐field properties for multiple flakes, thus providing strong verification of the accuracy of this model, while offering a novel approach to extracting dielectric functions of nanomaterials. In addition, by employing density functional theory (DFT), insights into the various vibrational states dictating the dielectric function model and the intriguing optical properties of α‐MoO3 are provided.
The IR permittivity of α‐MoO3 is extracted by correlative far‐ and near‐field measurements using FTIR reflectance spectroscopy and s‐SNOM polariton interferometry, thus providing a novel approach to extracting dielectric functions of nanomaterials. Moreover, through density functional theory, insights into the vibrational states dictating such permittivity are revealed.
Optical nanoantennas are of great importance for photonic devices and spectroscopy due to their capability of squeezing light at the nanoscale and enhancing light–matter interactions. Among them, ...nanoantennas made of polar crystals supporting phonon polaritons (phononic nanoantennas) exhibit the highest quality factors. This is due to the low optical losses inherent in these materials, which, however, hinder the spectral tuning of the nanoantennas due to their dielectric nature. Here, active and passive tuning of ultranarrow resonances in phononic nanoantennas is realized over a wide spectral range (≈35 cm−1, being the resonance linewidth ≈9 cm−1), monitored by near‐field nanoscopy. To do that, the local environment of a single nanoantenna made of hexagonal boron nitride is modified by placing it on different polar substrates, such as quartz and 4H‐silicon carbide, or covering it with layers of a high‐refractive‐index van der Waals crystal (WSe2). Importantly, active tuning of the nanoantenna polaritonic resonances is demonstrated by placing it on top of a gated graphene monolayer in which the Fermi energy is varied. This work presents the realization of tunable polaritonic nanoantennas with ultranarrow resonances, which can find applications in active nanooptics and (bio)sensing.
Near‐field nanoscopy monitors active and passive tuning of ultranarrow resonances in phononic nanoantennas over a wide spectral range (−35 cm−1, being the resonance linewidth ≈9 cm−1). Passive tunability can be realized by tailoring the dielectric environment of nanoantennas made of boron nitride, while reversible in situ tuning of narrow resonances is realized by placing nanoantennas on top of a graphene layer.
Objectives
To evaluate whether the Enhanced Feedback for Effective Cardiac Treatment (EFFECT) scale for 30‐day prediction of mortality is applicable to elderly adults with acute heart failure (AHF) ...in emergency departments (EDs) and whether discriminatory power is added with the inclusion of the Barthel Index (BI) to this scale (BI‐EFFECT scale).
Design
BI‐EFFECT is a multipurpose, nonintervention, multicenter cohort study.
Setting
Twenty EDs.
Participants
Individuals aged 65 and older with AHF.
Measurements
Information on baseline and episode characteristics and 30‐day mortality was collected, and participants were categorized according to the EFFECT scale. Baseline degree of functional dependence was measured using the BI. Receiver operating characteristic (ROC) curves were made of the EFFECT and BI‐EFFECT scales to predict mortality.
Results
One thousand sixty‐eight participants were included. Thirty‐day mortality was 5.1% and was directly and independently associated with high and very high risk categories of the EFFECT scale and with severe dependence. These two variables remained significant after adjustment of the model for both (OR = 4.5, 95% CI = 1.8–11.1 and OR = 2.9, 95% CI = 1.6–5.4, respectively). The EFFECT and the BI‐EFFECT scales had significant ROC curves (area under the ROC curve (AUC) = 0.69, 95% CI = from 0.62 to 0.76; and AUC = 0.75, 95% CI = 0.69–0.81, respectively), and the difference in discriminatory power between the second and the first was also statistically significant (P = .02).
Conclusion
The EFFECT scale may be applied in the elderly population, and inclusion of functional status according to the BI in the new BI‐EFFECT scale significantly improves the model for the prediction of 30‐day mortality.
BACKGROUND:The European Society of Cardiology recommends a 0/1-hour algorithm for rapid rule-out and rule-in of non–ST-segment elevation myocardial infarction using high-sensitivity cardiac troponin ...(hs-cTn) concentrations irrespective of renal function. Because patients with renal dysfunction (RD) frequently present with increased hs-cTn concentrations even in the absence of non–ST-segment elevation myocardial infarction, concern has been raised regarding the performance of the 0/1-hour algorithm in RD.
METHODS:In a prospective multicenter diagnostic study enrolling unselected patients presenting with suspected non–ST-segment elevation myocardial infarction to the emergency department, we assessed the diagnostic performance of the European Society of Cardiology 0/1-hour algorithm using hs-cTnT and hs-cTnI in patients with RD, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m, and compared it to patients with normal renal function. The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including cardiac imaging. Safety was quantified as sensitivity in the rule-out zone, accuracy as the specificity in the rule-in zone, and efficacy as the proportion of the overall cohort assigned to either rule-out or rule-in based on the 0- and 1-hour sample.
RESULTS:Among 3254 patients, RD was present in 487 patients (15%). The prevalence of non–ST-segment elevation myocardial infarction was substantially higher in patients with RD compared with patients with normal renal function (31% versus 13%, P<0.001). Using hs-cTnT, patients with RD had comparable sensitivity of rule-out (100.0% 95% confidence interval {CI}, 97.6–100.0 versus 99.2% 95% CI, 97.6–99.8; P=0.559), lower specificity of rule-in (88.7% 95% CI, 84.8–91.9 versus 96.5% 95% CI, 95.7–97.2; P<0.001), and lower overall efficacy (51% versus 81%, P<0.001), mainly driven by a much lower percentage of patients eligible for rule-out (18% versus 68%, P<0.001) compared with patients with normal renal function. Using hs-cTnI, patients with RD had comparable sensitivity of rule-out (98.6% 95% CI, 95.0–99.8 versus 98.5% 95% CI, 96.5–99.5; P=1.0), lower specificity of rule-in (84.4% 95% CI, 79.9–88.3 versus 91.7% 95% CI, 90.5–92.9; P<0.001), and lower overall efficacy (54% versus 76%, P<0.001; proportion ruled out, 18% versus 58%, P<0.001) compared with patients with normal renal function.
CONCLUSIONS:In patients with RD, the safety of the European Society of Cardiology 0/1-hour algorithm is high, but specificity of rule-in and overall efficacy are decreased. Modifications of the rule-in and rule-out thresholds did not improve the safety or overall efficacy of the 0/1-hour algorithm.
CLINICAL TRIAL REGISTRATION:URLhttps://www.clinicaltrials.gov. Unique identifierNCT00470587.
Insights for COVID-19 in 2023 Martín Sánchez, F J; Martínez-Sellés, M; Molero García, J M ...
Revista española de quimioterapia,
04/2023, Letnik:
36, Številka:
2
Journal Article
Odprti dostop
Predictions for a near end of the pandemic by the World Health Organization should be interpreted with caution. Current evidence indicates that the efficacy of a fourth dose of classical mRNA ...vaccines (BT162b2 or mRNA-1273) is low and short-lived in preventing SARS-CoV-2 infection in its predominant variant (Omicron). However, its efficacy is high against severe symptomatic infection, hospitalization and death. The new vaccines being introduced are bivalent and active against the Omicron variants. Potential new vaccines to be introduced in the coming year include a vaccine based on a recombinant protein that emulates the receptor binding domain of the Spike protein under development by the Spanish company Hipra, as well as vaccines for nasal or oral administration. Available information suggests that vaccines against COVID-19 can be administered in association with influenza vaccination without particular complications. New drugs against COVID-19, both antiviral and anti-inflammatory, are under investigation, but this does not seem to be the case with monoclonal antibodies. The indication to use masks in some circumstances will be maintained next year in view of the accumulation of scientific data on their efficacy. Finally, the long COVID or Post-COVID syndrome may continue to affect a very high proportion of patients who have had the disease, requiring combined diagnostic and therapeutic resources.
Aim
To determine whether initiation of antibiotic therapy (ABX) by procalcitonin (PCT) within 8 h of admission in patients presenting to the emergency department with symptoms and signs of acute ...heart failure (AHF) and elevated natriuretic peptides would improve clinical outcomes.
Methods and results
The study was a randomized multicentre clinical trial conducted at 16 sites in Europe. Patients were randomized to either a PCT‐guided strategy or standard care. Patients with PCT‐guided strategy (n = 370) had ABX initiated if PCT was > 0.2 μg/L. Patients with standard care (n = 372) had AHF care in accordance with published guidelines without PCT. The primary endpoint was 90‐day all‐cause mortality. Pre‐specified secondary endpoints included 30‐day all‐cause mortality and readmission and rate of pneumonia. The Data Safety and Review Committee recommended stopping the study for futility when 762 of the planned 792 patients had been enrolled. A total of 742 patients could be analysed. Patients were elderly (median age: 77 years), 38% were women, and had typical signs and symptoms of AHF. All‐cause mortality at 90 days was 10.3% in the PCT‐guided group vs. 8.2% in standard care (P = 0.316). Thirty‐day readmission was significantly higher in the PCT‐guided group vs. standard care but the difference vanished until day 90. The rate of pneumonia was overall low (7.5%) and not different between groups.
Conclusions
In patients with AHF, a strategy of PCT‐guided initiation of ABX was not more effective than a standard care strategy in improving clinical outcomes.
BACKGROUND:Cardiac myosin-binding protein C (cMyC) is a cardiac-restricted protein that is more abundant than cardiac troponins (cTn) and is released more rapidly after acute myocardial infarction ...(AMI). We evaluated cMyC as an adjunct or alternative to cTn in the early diagnosis of AMI.
METHODS:Unselected patients (N=1954) presenting to the emergency department with symptoms suggestive of AMI, concentrations of cMyC, and high-sensitivity (hs) and standard-sensitivity cTn were measured at presentation. The final diagnosis of AMI was independently adjudicated using all available clinical and biochemical information without knowledge of cMyC. The prognostic end point was long-term mortality.
RESULTS:Final diagnosis was AMI in 340 patients (17%). Concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 237 ng/L versus 13 ng/L, P<0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.924), hs-cTnT (AUC, 0.927), and hs-cTnI (AUC, 0.922) and superior to cTnI measured by a contemporary sensitivity assay (AUC, 0.909). The combination of cMyC with hs-cTnT or standard-sensitivity cTnI (but not hs-cTnI) led to an increase in AUC to 0.931 (P<0.0001) and 0.926 (P=0.003), respectively. Use of cMyC more accurately classified patients with a single blood test into rule-out or rule-in categoriesNet Reclassification Improvement +0.149 versus hs-cTnT, +0.235 versus hs-cTnI (P<0.001). In early presenters (chest pain <3 h), the improvement in rule-in/rule-out classification with cMyC was larger compared with hs-cTnT (Net Reclassification Improvement +0.256) and hs-cTnI (Net Reclassification Improvement +0.308; both P<0.001). Comparing the C statistics, cMyC was superior to hs-cTnI and standard sensitivity cTnI (P<0.05 for both) and similar to hs-cTnT at predicting death at 3 years.
CONCLUSIONS:cMyC at presentation provides discriminatory power comparable to hs-cTnT and hs-cTnI in the diagnosis of AMI and may perform favorably in patients presenting early after symptom onset.
CLINICAL TRIAL REGISTRATION:URLhttps://www.clinicaltrials.gov. Unique identifierNCT00470587.
Abstract Polariton canalization is characterized by intrinsic collimation of energy flow along a single crystalline axis. This optical phenomenon has been experimentally demonstrated at the nanoscale ...by stacking and twisting van der Waals (vdW) layers of α-MoO 3 , by combining α-MoO 3 and graphene, or by fabricating an h-BN metasurface. However, these material platforms have significant drawbacks, such as complex fabrication and high optical losses in the case of metasurfaces. Ideally, it would be possible to canalize polaritons “naturally” in a single pristine layer. Here, we theoretically predict and experimentally demonstrate naturally canalized phonon polaritons (PhPs) in a single thin layer of the vdW crystal LiV 2 O 5 . In addition to canalization, PhPs in LiV 2 O 5 exhibit strong field confinement ( $${{{\boldsymbol{\lambda }}}_{{{\bf{p}}} \sim \frac{{{\boldsymbol{\lambda }}}_{{{\bf{0}}}{{{\bf{27}}}$$ λ p ~ λ 0 27 ), slow group velocity (0.0015c), and ultra-low losses (lifetimes of 2 ps). Our findings are promising for the implementation of low-loss optical nanodevices where strongly directional light propagation is needed, such as waveguides or optical routers.
During the peak of hospitalizations of patients with severe Covid-19 in Italy and Spain in March, a group of researchers in these and other countries obtained and analyzed samples, resulting in the ...identification of two chromosomal loci associated with the disorder.
Although often investigated within the context of plant growth and development and/or seed composition, plant lipids have roles in responses to environment. To dissect changes in lipid and fatty acid ...composition linked to drought tolerance responses in oats, we performed a detailed profiling of (>90) different lipids classes during a time course of water stress. We used two oat cultivars, Flega and Patones previously characterized as susceptible and tolerant to drought, respectively. Significant differences in lipid classes (mono, di and triacylglycerols; respectively MAG, DAG, and TAG and free fatty acids FFA) and in their fatty acid (FA) composition was observed between cultivars upon drought stress. In Flega there was an increase of saturated FAs, in particular 16:0 in the DAG and TAG fractions. This led to significant lower values of the double bond index and polyunsaturated/saturated ratio in Flega compared with Patones. By contrast, Patones was characterized by the early induction of signaling-related lipids and fatty acids, such as DAGs and linolenic acid. Since the latter is a precursor of jasmonates, we investigated further changes of this signaling molecule. Targeted measurements of jasmonic acid (JA) and Ile-JA indicated early increases in the concentrations of these molecules in Patones upon drought stress whereas no changes were observed in Flega. Altogether, these data suggest a role for jasmonates and specific fatty acids in different lipid classes in coping with drought stress in oat.
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