Eco-friendly and biocompatible gelatin plasmonic filters for UV-vis-NIR light.

The quest for environmentally sustainable materials spans many fields and applications including optical materials. Here, we present the development of light filters using a gelatin-based nanocomposite. Owing to the plasmonic properties of metallic nanoparticles (NPs), strong light-matter interactions, these filters can be customized across the UV-Visible-NIR spectrum. The filters are designed for modular use, allowing for the addition or removal of desired spectral ranges. Moreover, the nanocomposites are composed of biodegradable and biocompatible materials which highlight the intersection of chemistry and ecological awareness for the exploration of new eco-friendly alternatives. These plasmonic gelatin-based filters block light due to the Localized Surface Plasmon Resonance (LSPR) of the NPs and can be tailored to meet various requirements, akin to a diner selecting options from a menu. This approach is inspired by culinary techniques, and we anticipate it will stimulate further exploration of biomaterials for applications in optics, materials science or electronics.

Exploring Adaptive Phenotypes for the Human Calcium-Sensing Receptor Polymorphism R990G.

Rainforest hunter-gatherers from Southeast Asia are characterized by specific morphological features including a particularly dark skin color (D), short stature (S), woolly hair (W), and the presence of steatopygia (S)-fat accumulation localized in the hips (DSWS phenotype). Based on previous evidence in the Andamanese population, we first characterized signatures of adaptive natural selection around the calcium-sensing receptor gene in Southeast Asian rainforest groups presenting the DSWS phenotype and identified the R990G substitution (rs1042636) as a putative adaptive variant for experimental follow-up. Although the calcium-sensing receptor has a critical role in calcium homeostasis by directly regulating the parathyroid hormone secretion, it is expressed in different tissues and has been described to be involved in many biological functions. Previous works have also characterized the R990G substitution as an activating polymorphism of the calcium-sensing receptor associated with hypocalcemia. Therefore, we generated a knock-in mouse for this substitution and investigated organismal phenotypes that could have become adaptive in rainforest hunter-gatherers from Southeast Asia. Interestingly, we found that mouse homozygous for the derived allele show not only lower serum calcium concentration but also greater body weight and fat accumulation, probably because of enhanced preadipocyte differentiation and lipolysis impairment resulting from the calcium-sensing receptor activation mediated by R990G. We speculate that such differential features in humans could have facilitated the survival of hunter-gatherer groups during periods of nutritional stress in the challenging conditions of the Southeast Asian tropical rainforests.

Effect of the comprehensive smoke-free law on time trends in smoking behaviour in primary healthcare patients in Spain: a longitudinal observational study.

OBJECTIVE: This study aimed to analyse the impact of comprehensive smoke-free legislation (SFL) on the prevalence and incidence of adult smoking in primary healthcare (PHC) patients from three Spanish regions, overall and stratified by sex. DESIGN: Longitudinal observational study conducted between 2008 and 2013. SETTING: 66 PHC teams in Catalonia, Navarre and the Balearic Islands (Spain). PARTICIPANTS: Population over 15 years of age assigned to PHC teams. PRIMARY AND SECONDARY OUTCOMES MEASURES: Quarterly age-standardised prevalence of non-smoker, smoker and ex-smoker and incidence of new smoker, new ex-smoker and ex-smoker relapse rates were estimated with data retrieved from PHC electronic health records. Joinpoint analysis was used to analyse the trends of age-standardised prevalence and incidence rates. Trends were expressed as annual percentage change and average annual percent change. RESULTS: The overall standardised smoker prevalence rate showed a significant downward trend (higher in men than women) and the overall standardised ex-smoker prevalence rate showed a significant increased trend (higher in women than men) in the three regions. Standardised smoker and ex-smoker prevalence rates were higher for men than women in all regions. With regard to overall trends of incidence rates, new smokers decreased significantly in Catalonia and Navarre and similarly in men and women, new ex-smokers decreased significantly and more in men in Catalonia and the Balearic Islands, and ex-smoker relapse increased in Catalonia (particularly in women) and decreased in Navarre. CONCLUSIONS: Trends in smoking behaviour in PHC patients remain unchanged after the implementation of comprehensive SFL. The impact of the comprehensive SFL might have been lessened by the effect of the preceding partial SFL.

Effect of comprehensive smoke-free legislation on asthma and coronary disease trends in Spanish primary care patients.

Background: To examine the impact of comprehensive smoke-free legislation (SFL) (Law 42/2010) on the incidence and prevalence of adult asthma and coronary disease in primary health care (PHC) patients from three Spanish regions, overall and stratified by sex. Methods: Longitudinal observational study conducted between 2007 and 2013 in the population over 15 years of age assigned to 66 PHC teams in Catalonia, Navarre and the Balearic Islands. Crude rates and age-standardized (truncated: asthma ≥ 16 years and coronary disease ≥ 35 years) incidence and prevalence rates using the direct method based on the European Standard Population were estimated based on data from PHC electronic health records. Joinpoint analysis was used to analyse the trends of age-standardized incidence and prevalence rates. Trends were expressed as annual percentage change and average annual percent change (AAPC). Results: The standardized asthma incidence rate showed a non-significant downward trend and the standardized prevalence rates rose significantly in the three regions. Standardized coronary disease incidence and prevalence rates were considerably higher for men than for women in all regions. The standardized coronary disease incidence rates in Catalonia (AAPC: -8.00%, 95% CI: -10.46; -5.47) and Navarre (AAPC: -3.66%, 95% CI: -4.95;-2.35) showed a significant downward trend from 2007 to 2013, overall and by sex. The standardized coronary disease prevalence trend rate increased significantly in the whole period in Catalonia and the Balearic Islands, although a non-significant downward trend was observed from 2010 in Catalonia. Conclusion: No changes in the trends of adult asthma and coronary disease in PHC Spanish patients were detected after the introduction of comprehensive SFL.

Composition and diameter modulation of magnetic nanowire arrays fabricated by a novel approach.

Straight magnetic nanowires composed of nickel and permalloy segments having different diameters are synthesized using a promising approach. This approach involves the controlled electrodeposition of each magnetic material into specially designed diameter-modulated porous alumina templates. Standard alumina templates are exposed to pore widening followed by a protective coating of the pore wall with ultrathin silica and further anodization. Micromagnetic simulations are employed to investigate the process of magnetization reversal in the fabricated nanowires when the magnetic materials exchange their places in the thick and thin segments. It is found that the magnetization reversal occurs by the propagation of transverse domain wall (DW) when the thick segment is composed of permalloy. However, the reversal process proceeds by the propagation of vortex DW when permalloy is located at the thin segment.

Bulk layered heterojunction as an efficient electrocatalyst for hydrogen evolution.

We describe the spontaneous formation of composite chalcogenide materials that consist of two-dimensional (2D) materials dispersed in bulk and their unusual charge transport properties for application in hydrogen evolution reactions (HERs). When MoS2 as a representative 2D material is deposited on transition metals (such as Cu) in a controlled manner, the sulfidation reactions also occur with the metal. This process results in remarkably unique structures, that is, bulk layered heterojunctions (BLHJs) of Cu-Mo-S that contain MoS2 flakes inside, which are uniformly dispersed in the Cu2S matrix. The resulting structures were expected to induce asymmetric charge transfer via layered frameworks and tested as electrocatalysts for HERs. Upon suitable thermal treatments, the BLHJ surfaces exhibited the efficient HER performance of approximately 10 mA/cm2 at a potential of -0.1 V versus a reversible hydrogen electrode. The Tafel slope was approximately 30 to 40 mV per decade. The present strategy was further generalized by demonstrating the formation of BLHJs on other transition metals, such as Ni. The resulting BLHJs of Ni-Mo-S also showed the remarkable HER performance and the stable operation over 10 days without using Pt counter electrodes by eliminating any possible issues on the Pt contamination.

Exosomal microRNAs isolated from plasma of mesenteric veins linked to liver metastases in resected patients with colon cancer.

Before reaching a peripheral vein (PV), miRNAs released by the tumor are diluted and dispersed throughout the body or even retained in a specific organ. We hypothesized that blood drawn from the tumor-draining vein could provide more homogeneous information than blood drawn from the PV as that blood would contain all the biomarkers released by the tumor before they reach a potential metastatic site. We have profiled 754 miRNAs in 15 colon cancer plasma samples from the tumor-draining vein, the mesenteric vein (MV), identifying 13 microRNAs associated with relapse. The prognostic impact of these miRNAs were validated in 50 MV and 50 paired PV plasma samples of stage I-III colon cancer patients. Four miRNAs, let-7g, miR-15b, miR-155 and miR-328, were found overexpressed in MV compared to PV, and patients with high levels of those miRNAs in MV plasma had shorter time to relapse. Interestingly, in patients developing liver metastases, the exosomal cargo of miR-328 was much greater in MV than in PV plasma indicating a possible role of miR-328 in the development of liver metastases. Our results indicate that in colon cancer, the primary tumor releases high concentrations of miRNAs through the MV, and some of them are contained in tumor derived exosomes.

Changes in CREB and deltaFosB are associated with the behavioural sensitization induced by methylenedioxypyrovalerone.

Methylenedioxypyrovalerone (MDPV) is a synthetic cathinone which has recently emerged as a designer drug of abuse. The objective of this study was to investigate the locomotor sensitization induced by MDPV in adolescent mice, and associated neuroplastic changes in the nucleus accumbens and striatum through deltaFosB and CREB expression. Behavioural testing consisted of three phases: Phase I: conditioning regimen with MDPV (0.3 mg/kg/day for five days) or saline; Phase II: resting (11 days); Phase III: challenged with MDPV (0.3 mg/kg), cocaine (10 mg/kg) or saline on day 16 for both groups. Mice repeatedly exposed to MDPV increased locomotor activity by 165-200% following acute MDPV or cocaine administration after an 11-day resting period, showing a MDPV-induced sensitization to itself and to cocaine. An explanation for this phenomenon could be the common mechanism of action between these two psychostimulants. Furthermore, the MDPV challenge resulted in higher levels of phospho-CREB in MDPV-conditioned mice compared with MDPV-naive mice, probably due to an up-regulation of the cAMP pathway. Likewise, MDPV exposure induced a persistent increase in the striatal expression of deltaFosB; the priming dose of MDPV also produced a significant increase in the accumbal expression of this transcription factor. This study constitutes the first evidence that an exposure to a low dose of MDPV during adolescence induces behavioural sensitization and provides a neurobiological basis for a relationship between MDPV and cocaine. We hypothesize that, similar to cocaine, both CREB and deltaFosB play a role in the induction of this behavioural sensitization.

Bottom-up Fabrication of Multilayer Stacks of 3D Photonic Crystals from Titanium Dioxide.

A strategy for stacking multiple ceramic 3D photonic crystals is developed. Periodically structured porous films are produced by vertical convective self-assembly of polystyrene (PS) microspheres. After infiltration of the opaline templates by atomic layer deposition (ALD) of titania and thermal decomposition of the polystyrene matrix, a ceramic 3D photonic crystal is formed. Further layers with different sizes of pores are deposited subsequently by repetition of the process. The influence of process parameters on morphology and photonic properties of double and triple stacks is systematically studied. Prolonged contact of amorphous titania films with warm water during self-assembly of the successive templates is found to result in exaggerated roughness of the surfaces re-exposed to ALD. Random scattering on rough internal surfaces disrupts ballistic transport of incident photons into deeper layers of the multistacks. Substantially smoother interfaces are obtained by calcination of the structure after each infiltration, which converts amorphous titania into the crystalline anatase before resuming the ALD infiltration. High quality triple stacks consisting of anatase inverse opals with different pore sizes are demonstrated for the first time. The elaborated fabrication method shows promise for various applications demanding broadband dielectric reflectors or titania photonic crystals with a long mean free path of photons.

Unveiling the Hard Anodization Regime of Aluminum: Insight into Nanopores Self-Organization and Growth Mechanism.

Pores growth mechanism and their self-ordering conditions are investigated for nanoporous alumina membranes synthesized by hard anodization (HA) of Al in a broad range of anodic conditions, covering oxalic acid electrolytes with concentrations from 0.300 M down to 0.075 M and potentiostatic anodization voltages between 120 and 225 V. The use of linear sweep voltammetry (LSV) and scanning and transmission electron microscopy, together with image analysis techniques allow one to characterize the intrinsic nature of the HA regime. HA of aluminum is explained on the basis of a phenomenological model taking into account the role of oxalate ions and their limited diffusion through alumina nanochannels from a bulk electrolyte. The depletion of oxalate ions at the bottom of the pores causes an increased growth of the alumina barrier layer at the oxide/electrolyte interface. Furthermore, an innovative method has been developed for the determination of the HA conditions leading to self-ordered pore growth in any given electrolyte, thus allowing one to extend the available range of interpore distances of the highly ordered hexagonal pore arrangement in a wide range of 240-507 nm, while keeping small pore diameters of 50-60 nm.

TiO2, SiO2, and Al2O3 coated nanopores and nanotubes produced by ALD in etched ion-track membranes for transport measurements.

Low-temperature atomic layer deposition (ALD) of TiO2, SiO2, and Al2O3 was applied to modify the surface and to tailor the diameter of nanochannels in etched ion-track polycarbonate membranes. The homogeneity, conformity, and composition of the coating inside the nanochannels are investigated for different channel diameters (18-55 nm) and film thicknesses (5-22 nm). Small angle x-ray scattering before and after ALD demonstrates conformal coating along the full channel length. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy provide evidence of nearly stoichiometric composition of the different coatings. By wet-chemical methods, the ALD-deposited film is released from the supporting polymer templates providing 30 µm long self-supporting nanotubes with walls as thin as 5 nm. Electrolytic ion-conductivity measurements provide proof-of-concept that combining ALD coating with ion-track nanotechnology offers promising perspectives for single-pore applications by controlled shrinking of an oversized pore to a preferred smaller diameter and fine-tuning of the chemical and physical nature of the inner channel surface.

Toward coordinated colloids: site-selective growth of titania on patchy silica particles.

Rational synthesis of coordinated spherical colloids is reported by site-selective growth of secondary hemispherical patches on primary spherical particles with quasi-defined coordination numbers and positions. We clarify the importance of mass transport phenomena on the site-specific secondary nucleation/growth in nanoparticulate colloidal systems. By comparing ultrasonic and conventional agitation during patch growth, we found that enhanced mass transfer is the key to controlled, homogeneous transport of the molecular precursors in a solvent onto the nanoparticles. With chemically defined nucleation sites, the surfaces of spherical silica particles were modified for use as a new kind of colloid with patches at desired coordination positions. Our observations represent a significant breakthrough in colloidal chemistry and self-assembly.

Electrochemical synthesis of highly ordered nanowires with a rectangular cross section using an in-plane nanochannel array.

Rapid and reproducible assembly of aligned nanostructures on a wafer-scale is a crucial, yet one of the most challenging tasks in the incorporation of nanowires into integrated circuits. We present the synthesis of a periodic nanochannel template designed for electrochemical growth of perfectly aligned, rectangular nanowires over large areas. The nanowires can be electrically contacted and characterized in situ using a pre-patterned multi-point measurement platform. During the measurement the wires remain within a thick oxide matrix providing protection against breaking and oxidation. We use laser interference lithography, reactive ion etching and atomic layer deposition to create cm-long parallel nanochannels with characteristic dimensions as small as 40 nm. In a showcase study pulsed electrodeposition of iron is carried out creating rectangular shaped iron nanowires within the nanochannels. By design of the device, the grown wires are in contact with an integrated electrode system on both ends directly after the deposition. No further processing steps are required for electrical characterization, minimizing the risk of damage and oxidation. The developed nanowire measurement device allows for multi-probe resistance measurements and can easily be adopted for transistor applications. The guided, in-plane growth of electrodeposited nanowire arrays which are tunable in size and density paves the way for the incorporation of nanowires into a large variety of multifunctional devices.

Rapid, conformal gas-phase formation of silica (SiO2) nanotubes from water condensates.

An innovative atomic layer deposition (ALD) concept, with which nanostructures of water condensates with high aspect ratio at equilibrium in cylindrical nanopores can be transformed uniformly into silica (SiO2) at near room temperature and ambient pressure, has been demonstrated for the first time. As a challenging model system, we first prove the conversion of cylindrical water condensates in porous alumina membranes to silica nanotubes (NTs) by introducing SiCl4 as a metal reactant without involving any catalytic reaction. Surprisingly, the water NTs reproducibly transformed into silica NTs, where the wall thickness of the silica NTs deposited per cycle was found to be limited by the amount of condensed water, and it was on the orders of ten nanometers per cycle (i.e., over 50 times faster than that of conventional ALD). More remarkably, the reactions only took place for 10-20 minutes or less without vacuum-related equipment. The thickness of initially adsorbed water layers in cylindrical nanopores was indirectly estimated from the thickness of formed SiO2 layers. With systematic experimental designs, we tackle the classical Kelvin equation in the nanosized pores, and the role of van der Waals forces in the nanoscale wetting phenomena, which is a long-standing issue lacking experimental insight. Moreover, we show that the present strategy is likely generalized to other oxide systems such as TiO2. Our approach opens up a new avenue for ultra-simple preparation of porous oxides and allows for the room temperature formation of dielectric layers toward organic electronic and photovoltaic applications.

Reversal modes and magnetostatic interactions in Fe3O4/ZrO2/Fe3O4 multilayer nanotubes.

Reversal modes and magnetostatic interactions of multilayered Fe(3)O(4)/ZrO(2)/Fe(3)O(4) nanotubes consisting of a ferromagnetic internal tube, an intermediate non-magnetic spacer and an external magnetic shell are investigated as a function of their geometric parameters and compared with those produced inside the pores of anodic alumina membranes by atomic layer deposition. Based on a continuum approach we obtained analytical expressions that underline the first experimental results and support their interpretation that the system of multilayer tubes behaves as the reversal of two isolated systems. It is observed that the magnetostatic interaction between both phases depends on the magnetic configurations in each phase and also on the geometrical parameters considered. These structures have potential applications in novel spintronics devices, ultra-small magnetic media and other nano-devices.

Understanding pore rearrangement during mild to hard transition in bilayered porous anodic alumina membranes.

We present a systematic study about the influence of the main anodization parameters (i.e., anodization voltage ramp and hard anodization voltage) on the pore rearrangement in nanoporous anodic alumina during mild to hard anodization regime transition. To cover the ranges between mild and hard regimes, the anodization parameters were each set to three levels (i.e., 0.5, 1.0, and 2.0 V s(-1) for the anodization voltage ramp and 80, 110, and 140 V for the hard anodization voltage). To the best of our knowledge, this is the first rigorous study about this phenomenon, which is quantified indirectly by means of a nickel electrodeposition. It is found that pore rearrangement takes place in a relatively random manner. Large areas of pores remain blocked when the anodization regime changes from mild to hard and, under certain anodization conditions, a pore branching takes place based on the self-ordering mechanism at work during anodization. Furthermore, it is statistically demonstrated by means of a design of experiments strategy that the effect of the anodization voltage ramp on the pore rearrangement is practically negligible in contrast to the hard anodization voltage effect. It is expected that this study gives a better understanding of structural changes in nanoporous anodic alumina when anodization is switched from mild to hard regime. Furthermore, the resulting nanostructures could be used to develop a wide range of nanodevices (e.g., waveguides, 1D photonic crystals, Fabry-Pérot interferometers, hybrid mosaic arrays of nanowires).

Controlled introduction of diameter modulations in arrayed magnetic iron oxide nanotubes.

To date, no large-scale preparative method for arrays of nanotube enables the experimentalist to arbitrarily define changes in the tubes' diameter along their length. To this goal, we start with anodic alumina substrates displaying controlled modulations in pore diameter obtained by alternating "mild" and "hard" electrochemical etching conditions. We then utilize atomic layer deposition (ALD) to coat the internal pore walls with conformal layers of an oxide. Ferromagnetic Fe(3)O(4) tubes of 10 nm wall thickness and 10-30 microm in length are thus prepared, which replicate the modulated silhouette of the template. Their magnetic properties strongly depend on the presence of diameter modulations. Introducing one or several very short segments of large diameter (150 nm) into an otherwise thin tube (70 nm diameter) brings its initially large coercive field down to a value close to the case of a homogeneously thick tube. Theoretical modeling emphasizes the major influence of the magnetostatic interactions between neighboring tubes. They are enhanced locally at the sites of diameter modulations, which directly translates into a reduction in coercive field.