The shifting care and outcomes for patients with endangered limbs - Critical limb ischemia (SCOPE-CLI) registry overview of study design and rationale

BACKGROUND

Critical limb ischemia (CLI), the most severe form of peripheral artery disease, is associated with pain, poor wound healing, high rates of amputation, and mortality (>20% at 1 year). Little is known about the processes of care, patients' preferences, or outcomes, as seen from patients' perspectives. The SCOPE-CLI study was co-designed with patients to holistically document patient characteristics, treatment preferences, patterns of care, and patient-centered outcomes for CLI.

METHODS

This 11-center prospective observational registry will enroll and interview 816 patients from multispecialty, interdisciplinary vascular centers in the United States and Australia. Patients will be followed up at 1, 2, 6, and 12 months regarding their psychosocial factors and health status. Hospitalizations, interventions, and outcomes will be captured for 12 months with vital status extending to 5 years. Pilot data were collected between January and July of 2021 from 3 centers.

RESULTS

A total of 70 patients have been enrolled. The mean age was 68.4 ± 11.3 years, 31.4% were female, and 20.0% were African American.

CONCLUSIONS

SCOPE-CLI is uniquely co-designed with patients who have CLI to capture the care experiences, treatment preferences, and health status outcomes of this vulnerable population and will provide much needed information to understand and address gaps in the quality of CLI care and outcomes.ClinicalTrials.gov identifier (NCT Number): NCT04710563 https://clinicaltrials.gov/ct2/show/NCT04710563.

A few-layer graphene for advanced composite PVDF membranes dedicated to water desalination: a comparative study

Membrane distillation is envisaged to be a promising best practice to recover freshwater from seawater with the prospect of building low energy-consuming devices powered by natural and renewable energy sources in remote and less accessible areas. Moreover, there is an additional benefit of integrating this green technology with other well-established operations dedicated to desalination. Today, the development of membrane distillation depends on the productivity-efficiency ratio on a large scale. Despite hydrophobic commercial membranes being widely used, no membrane with suitable morphological and chemical feature is readily available in the market. Thus, there is a real need to identify best practices for developing new efficient membranes for more productive and eco-sustainable membrane distillation devices. Here, we propose engineered few-layer graphene membranes, showing enhanced trans-membrane fluxes and total barrier action against NaCl ions. The obtained performances are linked with filling polymeric membranes with few-layer graphene of 490 nm in lateral size, produced by the wet-jet milling technology. The experimental evidence, together with comparative analyses, confirmed that the use of more largely sized few-layer graphene leads to superior productivity related efficiency trade-off for the membrane distillation process. Herein, it was demonstrated that the quality of exfoliation is a crucial factor for addressing the few-layer graphene supporting the separation capability of the host membranes designed for water desalination.

Mechanical exfoliation and layer number identification of single crystal monoclinic CrCl3

After the recent finding that CrI₃, displays ferromagnetic order down to its monolayer, extensive studies have followed to pursue new two-dimensional (2D) magnetic materials. In this article, we report on the growth of single crystal CrCl₃ in the layered monoclinic phase. The system after mechanical exfoliation exhibits stability in ambient air (the degradation occurs on a time scale at least four orders of magnitude longer than is observed for CrI₃). By means of mechanical cleavage and atomic force microscopy (AFM) combined with optical identification, we demonstrate the systematic isolation of single and few layer flakes onto 270 nm and 285 nm SiO₂/Si (100) substrates with lateral size larger than graphene flakes isolated with the same method. The layer number identification has been carried with statistically significant data, quantifying the optical contrast as a function of the number of layers for up to six layers. Layer dependent optical contrast data have been fitted within the Fresnel equation formalism determining the real and imaginary part of the wavelength dependent refractive index of the material. A layer dependent (532 nm) micro-Raman study has been carried out down to two layers with no detectable spectral shifts as a function of the layer number and with respect to the bulk.

P1151Impact of ARNI (LCZ696) on patients selection for ICD implantation in SCD primary prevention: a real-world experience

Background

 ICD implantation is recommended for primary prevention in patients with symptomatic NYHA II-III heart failure with reduced ejection fraction (< 35%) (HFrEF) and without left ventricle ejection fraction (LVEF) improvement despite at least three months of guideline-directed therapy. The use of angiotensin receptor-neprilysin inhibition with LCZ696 has shown to ameliorate left ventricle function and to reduce the ventricular arrhythmias burden in patients with HFrEF.

Purpose

The profile of patients with HFrEF who may benefit from therapy with LCZ696 without further requiring an ICD in primary prevention is still unknown. We aimed to assess the prevalence of these patients and to find potential clinical predictors of responsiveness to this treatment.

Methods

 We enrolled consecutive patients that started LCZ696 treatment for medical therapy optimization in the heart failure clinic of our institution. All of them were previously implanted with an ICD before LCZ696 availability (from 2009 to 2015). A cardiologist evaluated their home medications, clinical, and echocardiographic characteristics both at baseline (before starting LCZ696) and during follow up. The patients were grouped also according to the etiology of HF (ischemic/non-ischemic) and by gender. Patients were excluded if candidates to cardiac resynchronization therapy. Responsiveness to LCZ696 treatment was defined as an increase of LVEF to values > 35% at follow up (FU).

Results

A total of 49 patients (67.1 ± 9.8 years of age) were enrolled in this study and followed in the heart failure clinic of our institution (mean follow up 11.5 ± 4.9 months). Among them, 19 patients (38%) showed an increase in LVEF to values > 35% at follow up and a significant improvement in LVEF was appreciated (baseline LVEF: 31.2 ± 4.5 vs. follow up LVEF: 35.4 ± 8.0; p 0.003). No significant differences were recorded at baseline in LVEF within HF etiology and gender groups. At follow up, we found a significant increase in post-therapy LVEF only in the non-ischemic etiology group (from 31.5 ± 4.4 to 37.1 ± 8.1, p = 0.001) and in the male group (from 31.4 ± 4.5 to 34.9 ± 7.9, p = 0.005) in comparison with the ischemic etiology and the female group, respectively. No significant statistical differences were appreciated between responders and non-responders neither in terms of home medications nor in the LCZ696 doses, both at baseline and follow up.

Conclusion

This study suggests a potential impact of angiotensin receptor-neprilysin inhibition therapy in the selection of patients with HFrEF candidates to ICD in primary prevention. In this real-world experience from our HF clinic, we found a significant LVEF improvement in approximately 40% of patients treated with LCZ696. These patients, in FU evaluation, would not have needed for an ICD implantation. This benefit appears related to the non-ischemic etiology of HF and the male gender.

Abstract Figure. LVEF VARIATIONS

Hybrid Repair of an Iatrogenic Left Subclavian Artery Injury: A Case Report

We present the case of an iatrogenic injury to the left subclavian artery during placement of a port for chemotherapy. The artery was inadvertently accessed at its infraclavicular position, and then was perforated centrally, entering the mediastinum at the origin of the left vertebral artery. Given that the patient's posterior circulation was largely dependent on the left vertebral artery, it could not be sacrificed. To preserve her left vertebral artery and to avoid the need for a sternotomy, which would more substantially delay initiation of chemotherapy, we elected to perform a hybrid repair: an open left carotid to vertebral artery bypass with reversed great saphenous vein followed by repair of the proximal left subclavian injury with a covered stent graft, which was delivered via the left axillary artery. The patient recovered uneventfully. This case demonstrates a hybrid open and endovascular repair for a complex iatrogenic arterial injury. We were able to obtain a desirable outcome by careful assessment of the anatomic particulars of her injury and the technical constraints in proposed methods of repair, all in the context of the patient's overall goals of care.

Photothermal response of plasmonic nanofillers for membrane distillation

Light-to-heat conversion in plasmonic nanoparticles (NPs) inside polymeric membranes is beneficial for improving the efficiency of membrane distillation for seawater desalination. However, the physical mechanisms ruling photothermal membrane distillation are unclear yet. Here, we model the plasmonic photothermal light-to-heat conversion from Ag, Au, and Cu nanofillers in polymeric membranes for membrane distillation. Photothermal effects in the cases of isolated metallic NPs and their assembly are investigated considering size effects and excitation sources. The increasing content of metallic NPs improves the efficiency of the light-to-heat conversion. For a polymeric membrane, filled with 25% Ag NPs, our model well reproduces the experimental temperature increase of 10 K. Specifically, we find that Ag NPs with a radius of around 30-40 nm are favorite candidates for membrane heating with excitation energy in the visible/near-UV range. The incorporation of a term associated with heat losses into the heat transfer equation well reproduces the cooling effect associated with vaporization at the membrane surface. Compared to Ag NPs, Au and Cu NPs show a broadened absorption cross section and their resonance has a nonlinear behavior with varying the excitation energy, better matching with sunlight radiation spectrum.

Adsorption-assisted transport of water vapour in super-hydrophobic membranes filled with multilayer graphene platelets

The effects of confinement of multilayer graphene platelets in hydrophobic microporous polymeric membranes are here examined. Intermolecular interactions between water vapour molecules and nanocomposite membranes are envisaged to originate assisted transport of water vapour in membrane distillation processes when a suitable filler-polymer ratio is reached. Mass transport coefficients are estimated under different working conditions, suggesting a strong dependence of the transport on molecular interactions. Remarkably, no thermal polarization is observed, although the filler exhibits ultrahigh thermal conductivity. In contrast, enhanced resistance to wetting as well as outstanding mechanical and chemical stability meets the basic requirements of water purification via membrane distillation. As a result, a significant improvement of the productivity-efficiency trade-off is achieved with respect to the pristine polymeric membrane when low amounts of platelets are confined in spherulitic-like PVDF networks.

When plasmonics meets membrane technology

In this review, we present the applications of thermoplasmonics in membrane processes. We discuss the influence of the heat capacity of the solvent, the amount of plasmonic nanoparticles in the membrane, the intensity of the light source and the transmembrane flow rate on the increase of permeability. Remarkably, thermoplasmonic effects do not involve any noticeable loss of membrane rejection. Herein, we consider application feasibilities, including application fields, requirements of feed, alternatives of light sources, promising thermoplasmonic nanoparticles and scaling up issues.

The influence of chemical reactivity of surface defects on ambient-stable InSe-based nanodevices

We demonstrate that, in contrast to most two-dimensional materials, ultrathin flakes of InSe are stable under ambient conditions. Despite their ambient stability, InSe-based nanodevices show an environmental p-type doping, suppressed by capping InSe with hexagonal boron nitride. By means of transport experiments, density functional theory and vibrational spectroscopy, we attribute the p-type doping assumed by uncapped InSe under an ambient atmosphere to the decomposition of water at Se vacancies. We have estimated the site-dependent adsorption energy of O2, N2, H2O, CO and CO2 on InSe. A stable adsorption is found only for the case of H2O, with a charge transfer of only 0.01 electrons per water molecule.

Interplay of Surface and Dirac Plasmons in Topological Insulators: The Case of Bi_{2}Se_{3}

We have investigated plasmonic excitations at the surface of Bi_{2}Se_{3}(0001) via high-resolution electron energy loss spectroscopy. For low parallel momentum transfer q_{∥}, the loss spectrum shows a distinctive feature peaked at 104 meV. This mode varies weakly with q_{∥}. The behavior of its intensity as a function of primary energy and scattering angle indicates that it is a surface plasmon. At larger momenta (q_{∥}~0.04 Å^{-1}), an additional peak, attributed to the Dirac plasmon, becomes clearly defined in the loss spectrum. Momentum-resolved loss spectra provide evidence of the mutual interaction between the surface plasmon and the Dirac plasmon of Bi_{2}Se_{3}. The proposed theoretical model accounting for the coexistence of three-dimensional doping electrons and two-dimensional Dirac fermions accurately represents the experimental observations. The results reveal novel routes for engineering plasmonic devices based on topological insulators.

Aspergillus infections in transplant and non-transplant surgical patients

BACKGROUND

Aspergillus infections are associated commonly with immunocompromised states, such as transplantation and hematologic malignant disease. Although Aspergillus infections among patients having surgery occur primarily in transplant recipients, they are found in non-recipients of transplants, and have a mortality rate similar to that seen among transplant recipients.

METHODS

We conducted a retrospective analysis of a prospective data base collected from 1996 to 2010, in which we identified patients with Aspergillus infections. We compared demographic data, co-morbidities, and outcomes in non-transplant patients with those in abdominal transplant recipients. Continuous data were evaluated with the Student t-test, and categorical data were evaluated through χ(2) analysis.

RESULTS

Twenty-three patients (11 transplant patients and 12 non-transplant patients) were identified as having had Aspergillus infections. The two groups were similar with regard to their demographics and co-morbidities, with the exceptions of their scores on the Acute Physiology and Chronic Health Evaluation II (APACHE II), of 23.6±8.1 points for transplant patients vs. 16.8±6.1 points for non-transplant patients (p=0.03); Simplified Acute Physiology Score (SAPS) of 16.6±8.3 points vs. 9.2±4.1 points, respectively (p=0.02); steroid use 91.0% vs. 25.0%, respectively (p=0.003); and percentage of infections acquired in the intensive care unit (ICU) 27.3% vs. 83.3%, respectively (p=0.01). The most common site of infection in both patient groups was the lung. The two groups showed no significant difference in the number of days from admission to treatment, hospital length of stay following treatment, or mortality.

CONCLUSIONS

Although Aspergillus infections among surgical patients have been associated historically with solid-organ transplantation, our data suggest that other patients may also be susceptible to such infections, especially those in an ICU who are deemed to be critically ill. This supports the idea that critically ill surgical patients exist in an immunocompromised state. Surgical intensivists should be familiar with the diagnosis and treatment of Aspergillus infections even in the absence of an active transplant program.

Evidence of composite plasmon–phonon modes in the electronic response of epitaxial graphene

The electronic response of quasi-freestanding graphene on Pt(111) has been measured by high-resolution electron energy loss spectroscopy. Loss spectra reveal the existence of three distinct excitations: a dispersing feature due to the ordinary sheet plasmon and two dispersionless modes at 0.2 and 0.5–0.6 eV. The latter two features are assigned to the coupled plasmon–phonon excitation and to an interface plasmon, respectively. The complex interactions of plasmons with other particles have significant fundamental and practical implications on the electronic response of graphene and their knowledge is essential for tailoring upcoming graphene-based plasmonic devices.

Interplay between single-particle and plasmonic excitations in the electronic response of thin Ag films

High-resolution electron energy loss spectroscopy is used to study the electronic properties of thin Ag layers on Ni(111). In addition to the ordinary surface plasmon at 3.8 eV, we observe a broad feature at 7-8 eV, whose nature is investigated as a function of scattering geometry and primary electron beam energy. Loss measurements unambiguously indicate that this mode has spectral components from both free-electron Ag plasmonic excitations (free-electron surface plasmons and multipole plasmons) and single-particle transitions.

Helium, neon and argon diffraction from Ru(0001)

We present an experimental and theoretical study of He, Ne and Ar diffraction from the Ru(0001) surface. Close-coupling calculations were performed to estimate the corrugation function and the potential well depth in the atom-surface interaction in all three cases. DFT (density functional theory) calculations, including van der Waals dispersion forces, were used to validate the close-coupling results and to further analyze the experimental results. Our DFT calculations indicate that, in the incident energy range 20-150 meV, anticorrugating effects are present in the case of He and Ar diffraction, whereas normal corrugation is observed with Ne beams.

Plasmonic modes confined in nanoscale thin silver films deposited onto metallic substrates

Collective electronic excitations in nanoscale thin Ag layers adsorbed on Cu(111) and Ni(111) at room temperature have been investigated by high-resolution electron energy loss spectroscopy. Surface plasmon was found to be confined within grains on Ag thin films on Cu(111) nanostructured in islands. Annealing removed surface plasmon confinement and induced a negative linear term of the dispersion relation. On the other hand, on flat thin films on Ni(111) the dispersion of Ag surface plasmon is fully quadratic. Landau damping processes of the plasmonic excitation were found to be dependent on the growth mode. Ag multipole surface plasmon at 7.7 eV was observed only under stringent kinematic conditions enhancing surface sensitivity.

Comparative vibrational study on alkali coadsorption with CO and O on Ni(111) and Cu(111)

High-resolution electron energy loss spectroscopy was used to investigate alkali (Na, K) coadsorption with CO and O on Cu(111) and Ni(111). Measurements provided new insights in these systems. A CO-induced weakening of the alkali-substrate bond was revealed on both substrates. The effect is more pronounced for the Na+CO/Ni(111) system. Submonolayers of alkalis were found to promote the preferential population of the subsurface site for O/Cu(111) but not for O/Ni(111).

Collective excitations in nanoscale thin alkali films: Na/Cu(111)

The relationship between electron quantum confinement and the energy dispersion of the surface plasmon in nanoscale thin Na layers adsorbed on Cu(111) at room temperature have been studied by high resolution electron energy loss spectroscopy. Screening effects due to electron quantum confinement occurring in this system cause the lowering of the surface plasmon frequency and, moreover, make the energy range of its dispersion curve larger than in thick alkali films. Landau damping of the plasma excitation was unexpectedly very efficient at small momenta. The dispersion curve of the Na surface plasmon was found to depend on the primary electron beam energy. Multipole surface plasmon at 4.70 eV was observed only for higher impinging energies.

High resolution electron energy loss measurements of Na∕Cu(111) and H2O∕Na∕Cu(111): Dependence of water reactivity as a function of Na coverage

Collective electronic excitations occurring in Na layers grown on Cu(111) and in H2O/Na/Cu(111) have been investigated at room temperature by high resolution electron energy loss spectroscopy. Loss spectra taken for a coverage between 0.55 and 0.70 ML of Na are characterized by a feature at 3.0 eV assigned to a Mie resonance. Further increasing the Na coverage leads to the appearance of the Na surface plasmon at 3.9 eV. Water molecules dissociate on Na layers as shown by the appearance of the OH-Na vibration. Upon water adsorption, relevant effects on both electronic excitations and vibrational modes were observed as a function of Na coverage.