Coherent Dynamics in Solutions of Colloidal Plexcitonic Nanohybrids at Room Temperature

The increasing ability to prepare systems with nanoscale resolution and address their optical properties with ultrashort time precision is revealing quantum phenomena with tremendous potential in quantum nanotechnologies. Colloidal plexcitonic materials promise to play a pivotal role in this scenario. Plexcitons are hybrid states originating from the mixing of the plasmon resonances of metal nanostructures with molecular excitons. They allow nanoscale confinement of electromagnetic fields and the establishment of strong couplings between light and matter, potentially giving rise to controllable and tunable coherent phenomena. However, the characterization of the ultrafast coherent and incoherent dynamics of colloidal plexciton nanohybrids remains highly unexplored. Here, two dimensional electronic spectroscopy (2DES) is employed to study the quantum coherent interactions active after the photoexcitation of these systems. By comparing the response of the nanohybrids with the one of the uncoupled systems, the nonlinear photophysical processes at the base of the coherent dynamics are identified, allowing a step forward toward the effective understanding and exploitation of these nanomaterials

Assessment of malnutrition risk in post-stroke patients: a systematic literature review

Stroke is one of the main causes of death, especially when associated with malnutrition. Assessment of nutritional status in all stages of the disease is therefore mandatory to improve clinical outcome

The effective thermal conductivity of open cell replicated aluminium metal sponges

The effective thermal conductivity of aluminium open cell porous materials has been tested using the steady state method. The materials were manufactured using the replication technique producing samples of porosity ranging from 0.57 to 0.77 and pore sizes between 0.7 and 2.4 mm. The effective thermal conductivity was found to decrease with increasing porosity, but there was no notice influence of pore size. The results were found to be in general agreement with similar measurements found in the literature. The differences observed were attributed to the thickness and structure of the material in the matrix. Overall there was better agreement between the experiments than for the correlations and analytical expressions presented in the literature. An empirically derived correlation was obtained for sintered porous materials with porosities ranging from 0.5 to 1.0

When ring makes the difference: coordination properties of Cu2+/Cu+ complexes with sulfur-pendant polyazamacrocycles for radiopharmaceutical applications

Three polyazamacrocyclic ligands, i.e. 1,5,9-tris[2-(methylsulfanyl)ethyl]-1,5,9-triazacyclododecane (TACD3S), 1,4,7,10-tetrakis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetrazacyclotridecane (TRI4S) and 1,4,8,11-tetrakis[2-(methylsulfanyl)ethyl]-1,4,8,11-tetrazacyclotetradecane (TE4S), were considered as potential chelators for the medically relevant copper radioisotopes. The ligands have been synthesized through facile, single-step reactions, and their acidity constants have been measured in aqueous solution at 25 degrees C. The kinetic, thermodynamic, electrochemical and structural properties of their Cu2+ and Cu+ complexes were investigated in aqueous solution at 25 degrees C using spectroscopic (UV-Visible, EPR, NMR) and electrochemical techniques (pH-potentiometric titrations, cyclic voltammetry and electrolysis). TACD3S was demonstrated to be unable to stabilize Cu2+, whereas for TRI4S and TE4S the formation of stable monocupric (CuL2+) and monocuprous (CuL+) complexes was detected. TRI4S coordinates Cu(2+)via a [4N] and a [4N]S array of donor atoms while with TE4S only the latter geometry exists. The thermodynamic stability and the kinetic inertness of the copper complexes formed by TACD3S, TRI4S and TE4S were compared with those previously reported for 1,4,7,10-tetrakis-[2-(methylsulfanyl)ethyl]-1,4,7,10-tetrazacyclododecane (DO4S) to unravel the influence of the ring size and the nitrogen donor array on the copper chelation properties of these sulfur-rich macrocycles. The copresence of four nitrogen atoms is an essential feature to allow effective copper coordination when a 12-member ring is employed, as the Cu2+-DO4S complexes were far more stable than those of Cu2+-TACD3S. Furthermore, the larger ring size of TRI4S and TE4S, when compared to DO4S, progressively increases the rate of the Cu2+ complexation reactions but decreases the thermodynamic stability of the Cu2+ complexes. Despite this, the ability of TRI4S and TE4S to stably accommodate both copper oxidation states makes them very attractive for application in nuclear medicine as they could avoid the demetallation after the biologically triggered Cu2+/Cu+ reduction

A framework for data regression of heat transfer data using machine learning

Data availability: The data that has been used is confidential.Machine Learning (ML) algorithms are emerging in various industries as a powerful complement/alternative to traditional data regression methods. A major reason is that, unlike deterministic models, they can be used even in the absence of detailed phenomenological knowledge. Not surprisingly, the use of ML algorithms is being explored also in heat transfer applications. It is of particular interest in systems dealing with complex geometries and underlying phenomena (e.g. fluid phase change, multi-phase flow, heavy fouling build-up). However, heat transfer systems present specific challenges that need addressing, such as the scarcity of high-quality data, the inconsistencies across published data sources, the complex (and often correlated) influence of inputs, the split of data between training and testing sets, and the limited extrapolation capabilities to unseen conditions. In an attempt to help overcome some of these challenges and, more importantly, to provide a systematic approach, this article reviews and analyses past efforts in the application of ML algorithms to heat transfer applications, and proposes a regression framework for their deployment to estimate key quantities (e.g. heat transfer coefficient), to be used for improved design and operation of heat exchangers. The framework consists of six steps: i) data pre-treatment, ii) feature selection, iii) data splitting philosophy, iv) training and testing, v) tuning of hyperparameters, and vi) performance assessment with specific indicators, to support the choice of accurate and robust models. A relevant case study involving the estimation of the condensation heat transfer coefficient in microfin tubes is used to illustrate the proposed framework. Two data-driven algorithms, Deep Neural Networks and Random Forest, are tested and compared in terms of their estimation and extrapolation capabilities. The results show that ML algorithms are generally more accurate in predicting the heat transfer coefficient than a well-known semi-empirical correlation proposed in past studies, where the mean absolute error of the most suitable ML model is 535 [Wm2K-1], compared to the error using the correlation of 1061 [Wm2K-1]. In terms of extrapolation, the selected ML model has a mean absolute error of 1819 [Wm2K-1], while for the correlation is 1111 [Wm2K-1], indicating a disadvantage of the use of semi-empirical models, although the comparison was not entirely suitable, given that the correlation was used as is and no training was done. In addition, feature selection enables simpler models that depend only on features that are potentially most related to the target variable. Special attention is needed however, as overfitting and limited extrapolation capabilities are common difficulties that are encountered when deploying these models.Hexxcell Ltd

EVALUATION OF THE SHELF LIFE AND MICROBIOLOGICAL PARAMETERS IN A CHILLED READY TO EAT MEAT PRODUCT: THE "VITEL TONNÈ"

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Targeted delivery of photosensitizers: efficacy and selectivity issues revealed by multifunctional ORMOSIL nanovectors in cellular systems

PEGylated and non-PEGylated ORMOSIL nanoparticles prepared by microemulsion condensation of vinyltriethoxy-silane (VTES) were investigated in detail for their micro-structure and ability to deliver photoactive agents. With respect to pure silica nanoparticles, organic modification substantially changes the microstructure and the surface properties. This in turn leads to a modulation of both the photophysical properties of embedded photosensitizers and the interaction of the nanoparticles with biological entities such as serum proteins. The flexibility of the synthetic procedure allows the rapid preparation and screening of multifunctional nanosystems for photodynamic therapy (PDT). Selective targeting of model cancer cells was tested by using folate, an integrin specific RGD peptide and anti-EGFR antibodies. Data suggest the interference of the stealth-conferring layer (PEG) with small targeting agents, but not with bulky antibodies. Moreover, we showed that selective photokilling of tumour cells may be limited even in the case of efficient targeting because of intrinsic transport limitations of active cellular uptake mechanisms or suboptimum localization

Lung fibrosis quantified by HRCT in scleroderma patients with different disease forms and ANA specificities

Objective: to define the prevalence of interstitial lung fibrosis in systemic sclerosis (SSc) and its relationship with the different clinical forms of disease and ANA specificities. Methods: fifty patients with SSc were submitted to pulmonary high resolution computed tomography (HRCT). Lung abnormalities were evaluated according to Warrick's score that considers both the severity and the extent of fibrotic lesions. Results: pulmonary HRCT abnormalities were observed in 84% of SSc patients. Ground glass aspects (60%), irregular pleural margins (56%) and septal/subpleural lines (68%) were the most common lesions. The distribution of these abnormalities favoured the posterior basilar segments of both lungs. HRCT findings were significantly more frequent in males and in patients with the cutaneous diffuse form of SSc and with the specific antibody anti-Scl70. Conclusions: HRCT is a very useful method for the diagnosis of interstitial lung fibrosis in SSc. Warrick's score permits to quantify the HRCT findings and to evaluate their relationship with the disease clinical forms and ANA specificities

Experimental investigation of pressure-drop characteristics across multi-layer porous metal structures

This study investigates the effect of airflow (in the range of 0–70 m s-1) on the pressure-drop characteristics for a novel multi-layered, nickel-based porous metal, as a function of thickness (affected by sectioning) and density (affected by compression). In addition to generating unique data for these materials, the study highlights the need for precise pinpointing of the different flow regimes (Darcy, Forchheimer and Turbulent) in order to enable accurate determination of the permeability (K) and form drag coefficient (C) defined by the Forchheimer equation and to understand the complex dependence of length-normalised pressure drop on sample thickness