Addressing lung cancer screening eligibility in Spain using 2013 and 2021 US Preventive Service Task Force criteria: cross-sectional study.

Objectives: The aim of the study was to ascertain the percentage of Spanish lung cancer cases that would fulfil the lung cancer screening inclusion criteria recommended by the United States Preventive Service Task Force (USPSTF) in 2013 and 2021. Methods: A cross-sectional study was carried out. All lung cancer cases registered in the Thoracic Tumor Registry with data on date of birth, date of diagnosis, smoking habit, number of pack-years and time elapsed since smoking cessation were included. Results: The study included 15 006 patients diagnosed with lung cancer in Spain between 2016 and 2022. Eligibility to participate in screening increased from 53.7% to 63.5% (an increase of 9.8%) according to the 2013 and 2021 recommendations, respectively. The percentage of eligible men rose by 9.2 percentage points with the 2021 versus 2013 recommendations, whereas this rise was 11.5 percentage points in women. Under the 2021 recommendations, 36.6% of women and 5.3% of men would not have fulfilled the screening inclusion criteria due to being never-smokers; 14.9% of women and 11.0% of men would not have fulfilled the age criterion; and 27.0% of ex-smokers among women compared to 35.6% among men would not have been eligible due to >15 years having elapsed since smoking cessation. Conclusions: In Spain, over one-third of lung cancer cases could not be detected through screening, by virtue of not meeting the most recent inclusion criteria stated by the USPSTF. The degree of fulfilment in a potential nationwide screening programme should be analysed, with the aim of establishing inclusion criteria in line with each country's context.

Polymer Rheology and Processing of Nano- and Micro-Composites.

The development of new technologies strongly depends on the design of new materials [...].

Extruded PLA Nanocomposites Modified by Graphene Oxide and Ionic Liquid.

Polylactic acid (PLA)-based nanocomposites were prepared by twin-screw extrusion. Graphene oxide (GO) and an ionic liquid (IL) were used as additives separately and simultaneously. The characterization of the samples was carried out by means of Fourier transform infrared (FT-IR) and Raman spectroscopies, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The viscoelastic behavior was determined using dynamic mechanical analysis (DMA) and rheological measurements. IL acted as internal lubricant increasing the mobility of PLA chains in the solid and rubbery states; however, the effect was less dominant when the composites were melted. When GO and IL were included, the viscosity of the nanocomposites at high temperatures presented a quasi-Newtonian behavior and, therefore, the processability of PLA was highly improved.

The Effect of Number of Arms on the Aggregation Behavior of Thermoresponsive Poly(N-isopropylacrylamide) Star Polymers.

The thermoresponsive nature of aqueous solutions of poly(N-isopropylacrylamide) (PNIPAAM) star polymers containing 2, 3, 4, and 6 arms has been investigated by turbidity, dynamic light scattering, rheology, and rheo-SALS. Simulations of the thermosensitive nature of the single star polymers have also been conducted. Some of the samples form aggregates even at temperatures significantly below the lower critical solution temperature (LCST) of PNIPAAM. Increasing concentration and number of arms promotes associations at low temperatures. When the temperature is raised, there is a competition between size increase due to enhanced aggregation and a size reduction caused by contraction. Monte Carlo simulations show that the single stars contract with increasing temperature, and that this contraction is more pronounced when the number of arms is increased. Some samples exhibit a minimum in the turbidity data after the initial increase at the cloud point. The combined rheology and rheo-SALS data suggest that this is due to a fragmentation of the aggregates followed by re-aggregation at even higher temperatures. Although the 6-arm star polymer aggregates more than the other stars at low temperatures, the more compact structure renders it less prone to aggregation at temperatures above the cloud point.

Graphene-Ionic Liquid Thin Film Nanolubricant.

Graphene (0.5 wt.%) was dispersed in the hydrophobic room-temperature ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (IL) to obtain a new non-Newtonian (IL + G) nanolubricant. Thin layers of IL and (IL + G) lubricants were deposited on stainless steel disks by spin coating. The tribological performance of the new thin layers was compared with those of full fluid lubricants. Friction coefficients for neat IL were independent of lubricant film thickness. In contrast, for (IL + G) the reduction of film thickness not only afforded 40% reduction of the friction coefficient, but also prevented wear and surface damage. Results of surface profilometry, scanning and transmission electron microscopy (SEM and TEM), energy dispersive analysis (EDX), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were discussed.

Extrusion of Polymer Nanocomposites with Graphene and Graphene Derivative Nanofillers: An Overview of Recent Developments.

This review is focused on the recent developments of nanocomposite materials that combine a thermoplastic matrix with different forms of graphene or graphene oxide nanofillers. In all cases, the manufacturing method of the composite materials has been melt-processing, in particular, twin-screw extrusion, which can then be followed by injection molding. The advantages of this processing route with respect to other alternative methods will be highlighted. The results point to an increasing interest in biodegradable matrices such as polylactic acid (PLA) and graphene oxide or reduced graphene oxide, rather than graphene. The reasons for this will also be discussed.

Synthesis and Characterization of New Layered Double Hydroxide-Polyolefin Film Nanocomposites with Special Optical Properties.

In this study, we have synthesized new double layered hydroxides to be incorporated to low density polyethylene thermoplastic matrix. These new composites present promising applications as materials to build greenhouses due to the enhancement of their optical properties. A characterization of the modified nanoclay has been performed by means of X-ray fluorescence (XRF), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). We have prepared a series of polyolefin-based films to evaluate the effect of the addition of a whitening agent (disodium 2,2'-((1,1'-biphenyl)-4,4'-diyldivinylene)bis(benzenesulfonate)), the modified hydrotalcite-like material and a commercial dispersant. The rheological and mechanical characterization of the films have proved that the inclusion of the modified-layered double hydroxides (LDHs) do not substantially affect the processing and mechanical performance of the material. On the other hand, optical properties of the nanocomposites are improved by reducing the transmission in the UVA region.

Synthesis and Exploration of the Lubricating Behavior of Nanoparticulated Mo15S19 in Linseed Oil.

Molybdenum chalcogenides present interesting properties beyond their superconducting critical temperatures and upper critical magnetic fields, making them suitable for potential applications in tribology, batteries, catalysis, or thermopower. In this study, Mo15S19 nanoparticles with an average diameter of 10 nm were synthesized via the reaction of ammonium molybdate with hydrochloric acid and elemental sulfur as reducers at 245 °C. The oxidation to MoO3 in air was efficiently avoided by using linseed oil as a reaction medium and dispersant. Scanning electron microscopy (SEM) micrographs of the as-prepared samples revealed the presence of few-micron-size aggregates, while transmission electron microscopy (TEM) characterization evidenced that the samples were polynanocrystalline with a high degree of homogeneity in size (standard deviation of 2.7 nm). The absence of the first-order (00l) reflection in the X-ray diffraction pattern was also indicative of the absence of Mo3S4 stacking, suggesting that it was a non-layered material. A dispersion of the nanoparticles in linseed oil has been studied as a lubricant of steel⁻steel sliding contacts, showing the formation of a surface layer that reduces wear and mean friction coefficients with respect to the base oil.

Adsorption of cationic hydroxyethylcellulose derivatives onto planar and curved gold surfaces.

The adsorption of two positively charged hydroxyethylcellulose derivatives with 7 and 60 mol % positively charged groups and a cationic, hydrophobically modified hydroxyethylcellulose containing 1 mol % hydrophobic groups and 7 mol % charged groups onto flat and spherical citrate-coated gold surfaces of different sizes has been investigated. The planar surfaces were studied by means of the quartz crystal microbalance with dissipation monitoring, whereas nanoparticle suspensions were examined using dynamic light scattering and UV-vis spectroscopy. Two different driving forces for adsorption have been evaluated: the electrostatic interaction between the positive charges on the polymers and the negatively charged gold surfaces and the affinity of the polymers for gold due to hydrophobic interactions. The comparison between the data obtained from curved and planar surfaces suggests a strong correlation between surface curvature and adlayer conformation in the formation of the hybrid polymer-gold nanoparticles. The influence of particle size on the amount of adsorbed polymer has been evaluated for the different polymers. The impact of the ionic strength on polymer adsorption has been explored, and the adsorbed polymer layer has been found to protect the gold nanoparticles from aggregation when salt is added to the solution. The addition of salt to a mixture of gold particles and a charged polymer can induce a thicker adsorbed layer at low salinity, and desorption was found at high levels of salt addition.

Single-molecule behavior of asymmetric thermoresponsive amphiphilic copolymers in dilute solution.

A bead-and-spring model has been used to simulate the behavior of thermoresponsive asymmetric diblock amphiphilic copolymers with aid of Monte Carlo simulations. The alteration of the thermodynamic conditions was mimicked by using a Lennard-Jones potential, which was related to the measured temperatures by comparison with experimental data for aqueous solutions of two sets of diblock copolymers, namely methoxypoly(ethylene glycol)-block-poly(N-isopropylacrylamide), one with different lengths of the hydrophilic block (MPEG(n)-b-PNIPAAM(71)) and one with varying lengths of the hydrophobic block (MPEG(57)-b-PNIPAAM(m)). The influence of the length of both the thermoresponsive and the hydrophilic block on the size and conformation of single molecules at various temperatures was studied by means of simulations. The temperature-induced contraction of the copolymer (MPEG(n)-b-PNIPAAM(71)) entities is only modestly affected by changing the length of the hydrophilic block, whereas for the MPEG(57)-b-PNIPAAM(m) copolymer both the transition temperature and the magnitude of the compression of the molecules are strongly influenced by the length of the thermosensitive block. When the MPEG chain fully covers the hydrophobic core, the copolymer moieties are stabilized, whereas poorly covered cores can promote interchain aggregation at elevated temperatures.

Characterization of polyelectrolyte features in polysaccharide systems and mucin.

This review elucidates several aspects on the behavior of charged polysaccharides and mucin. Viscosification of dilute aqueous solutions of hyaluronan (HA) occurs in the course of time at low shear flow, whereas shear thinning as time evolves is found at moderate shear rates. Hydrogen bonds and electrostatic interaction play an important role for the emergence of these features. No time effect of the viscosity is observed for semidilute HA solutions. A degradation of HA is observed at low and high pH and this effect continues over long times, and it is only in the approximate interval 5>2 the negative charges suppress the tendency of forming associations. At pH<2, the mucin chains are compressed and they are decorated by some positive charges. In the semidilute regime, a fragmented network is developed. The intense association in semidilute solutions of mucin at pH=2 is further supported by the results from rheo-small angle light scattering measurements. Effects of ionic strength on the radius of gyration (R(g)) for dilute solutions of HA (pH=7) and positively charged hydroxyethylcellulose (HEC(+)) are studied with the aid of Monte Carlo simulations, and essential features of the polyelectrolyte effect on R(g) are captured in the computer simulation. Strong interactions are observed in aqueous mixtures of an anionic polysaccharide (HEC(-)) and an oppositely charged surfactant (cetyltrimethylammonium bromide; CTAB); this gives rise to extensive associations and macroscopic phase separation is approached. The massive association complexes are disclosed in the SANS experiments by a pronounced upturn in the scattered intensity at low values of the wave vector.

Temperature-induced intermicellization and contraction in aqueous mixtures of sodium dodecyl sulfate and an amphiphilic diblock copolymer.

Aqueous solutions of a thermoresponsive amphiphilic diblock copolymer, containing poly(N-isopropylacrylamide), in the presence of the anionic sodium dodecyl sulfate (SDS) surfactant can undergo a temperature-induced transition from loose intermicellar clusters to collapsed core-shell nanostructures. The polymer-surfactant mixtures have been characterized with the aid of turbidity, small-angle neutron scattering (SANS), intensity light scattering (ILS), dynamic light scattering (DLS), shear viscosity, and rheo-small angle light scattering (rheo-SALS). In the absence of SDS, compressed intermicellar structures are formed at intermediate temperatures, and at higher temperatures further aggregation is detected. The SANS results disclose a structure peak in the scattered intensity profile at the highest measured temperature. This peak is ascribed to the formation of ordered structures (crystallites). In the presence of a low amount of SDS, a strong collapse of the intermicellar clusters is observed at moderate temperatures, and only a slight renewed interpolymer association is found at higher temperatures because of repulsive electrostatic interactions. Finally, at moderate surfactant concentrations, temperature-induced loose intermicellar clusters are detected but no shrinking was registered in the considered temperature range. At a high level of SDS addition, large polymer-surfactant complexes appear at low temperatures, and these species are compressed at elevated temperatures. The rheo-SALS results show that the transition structures are rather fragile under the influence of shear flow.

Temperature-induced formation and contraction of micelle-like aggregates in aqueous solutions of thermoresponsive short-chain copolymers.

A combination of turbidity, light scattering, and steady shear viscosity experiments has revealed that aqueous solutions of an amphiphilic diblock copolymer or a negatively charged triblock copolymer, both containing poly(N-isopropylacrylamide), can undergo a temperature-induced transition from loose intermicellar clusters to collapsed core-shell nanostructures. Turbidity, light scattering, and viscosity results of these short-chain copolymers disclose transition peaks at intermediate temperatures. At high temperatures, the compact core-shell particles from the diblock copolymer aggregate, whereas no renewed interpolymer association is observed for the triblock copolymer or for the solution of the diblock copolymer with added sodium dodecyl sulfate because the electrostatic repulsive interactions suppress the tendency of forming interpolymer clusters. The temperature-induced building up of intermicellar structures and the formation of large aggregates at high temperature in the solution of the diblock copolymer is significantly reduced under the influence of high shear rates.

Temperature-induced intermicellization of "hairy" and "crew-cut" micelles in an aqueous solution of a thermoresponsive copolymer.

Temperature-induced intermicellar structures in aqueous solutions of the thermoresponsive methoxypoly(ethylene glycol)-block-poly(N-isopropylacrylamide) (MPEGn-b-NIPAAM71) copolymer that exhibit a lower critical solution temperature were studied by means of turbidimetry, dynamic light scattering (DLS), shear viscosity, and rheo small-angle light scattering (rheo-SALS) methods. The length of the hydrophilic chains (MPEG) of the copolymer varies from n=0 to n=114. It is shown that this change has a major impact on the temperature-induced association behavior of the polymer in solution. The turbidity results at quiescent conditions revealed a transition peak in the turbidity curve at intermediate temperatures, and this peak as well as the cloud point is shifted toward higher temperatures with increasing length of the hydrophilic chains of the copolymer. The DLS measurements disclosed a fast and a slow relaxation mode, which both are diffusive. From the fast and slow relaxation times the sizes of unimers/micelles and intermicellar clusters, respectively, can be determined. The temperature-induced aggregation is less pronounced in solutions of copolymers with long hydrophilic chains, and the intermicellar structures exhibit an interesting transition at intermediate temperatures. In the shear viscosity measurements large association complexes are formed at high temperatures and at low shear flow for the polymers with short hydrophilic chains, whereas at high shear rates breakup of interaggregate chains was observed. For the copolymer with the highest number of hydrophilic chains (n=114), a novel transition peak was found in the viscosity data. The rheo-SALS results divulged shear-induced structural changes of the association complexes at elevated temperatures. For copolymers with short hydrophilic chains, shear-induced disruption of association complexes was found at higher temperatures, whereas for hairy micelles augmented shear flow promoted the growth of complexes.

Characterization of interactions in aqueous solutions of hydroxyethylcellulose and its hydrophobically modified analogue in the presence of a cyclodextrin derivative.

The formation of associative networks in semidilute aqueous solutions of hydrophobically modified hydroxyethylcellulose (HM-HEC) is dependent on intermolecular hydrophobic interactions. Addition of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) monomers to the system provides decoupling of these associations via inclusion complex formation with the polymer hydrophobic tails. Results from viscosity, polymer NMR self-diffusion, and dynamic light scattering (DLS) measurements show that the hydrophobic interactions in HM-HEC solutions are effectively suppressed when the level of HP-beta-CD addition increases. Small-angle neutron scattering (SANS) results reveal that the large-scale association complexes in HM-HEC solutions are strongly diminished when the concentration of HP-beta-CD rises. The time correlation data obtained from the DLS experiments unveiled the existence of two relaxation modes: one single exponential at short times followed by a stretched exponential at longer times. The fast mode is always diffusive, whereas the slow mode exhibits progressively stronger wavevector dependence as the intensity of the hydrophobic interactions increases. This feature, as well as the accompanying drop of the stretched exponential beta as the HP-beta-CD concentration decreases, is attributed to enhanced hydrophobic interactions and can be well rationalized in the framework of the coupling model of Ngai.