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Self-assembling peptides (SAPs) have been increasingly studied as hydrogel–former gelators because they can create biocompatible environments. A common strategy to trigger gelation, is to use a pH variation, but most methods result in a change in pH that is too rapid, leading to gels with hardly reproducible properties. Here, we use the urea–urease reaction to tune gel properties, by a slow and uniform pH increase. We were able to produce very homogeneous and transparent gels at several SAP concentrations, ranging from c=1g/L to c=10g/L. In addition, by exploiting such a pH control strategy, and combining photon correlation imaging with dynamic light scattering measurements, we managed to unravel the mechanism by which gelation occurs in solutions of (LDLK)3-based SAPs. We found that, in diluted and concentrated solutions, gelation follows different pathways. This leads to gels with different microscopic dynamics and capability of trapping nanoparticles. At high concentrations, a strong gel is formed, made of relatively thick and rigid branches that firmly entrap nanoparticles. By contrast, the gel formed in dilute conditions is weaker, characterized by entanglements and crosslinks of very thin and flexible filaments. The gel is still able to entrap nanoparticles, but their motion is not completely arrested. These different gel morphologies can potentially be exploited for controlled multiple drug release.

Objective. Knee osteoarthritis (KOA) is a progressive joint disorder that significantly impairs patients’ quality of life. Effective long-term management of KOA remains challenging due to limited pharmacological options and associated adverse effects. This monocentric, retrospective observational study evaluated the efficacy and safety of a fixed-dose tramadol/paracetamol combination (75/650 mg) in alleviating pain in patients with grade I-II KOA according to the Kellgren-Lawrence classification. Methods. A total of 30 patients treated for 15 days were assessed using the Numerical Rating Scale for pain, the Western Ontario and McMaster Universities Osteoarthritis Index for functional impairment, and the Pittsburgh Sleep Quality Index for sleep quality. Results. Results showed a 30% and 50% pain reduction in 86% and 43% of patients, respectively, alongside significant improvements in functional mobility and sleep quality. Adverse events, including nausea, itching, and sleepiness, occurred in 10% of patients and did not necessitate treatment discontinuation. Efficacy was consistent across demographic and clinical subgroups, possibly suggesting broad treatment applicability. Conclusions. While the findings could support tramadol/paracetamol as a safe and effective first-line therapy for KOA, reinforcing its role in optimizing KOA management strategies, limitations such as the small sample size and lack of a control group highlight the need for further research.

Colloidal solids (COLIS) is a state-of-the-art light scattering setup developed for experiments onboard the International Space Station (ISS). COLIS allows for probing the structure and dynamics of soft matter systems on a wide range of length scales, from a few nm to tens of microns, and on time scales from 100 ns to tens of hours. In addition to conventional static and dynamic light scattering, COLIS includes depolarized dynamic light scattering, a small-angle camera, photon correlation imaging, and optical manipulation of thermosensitive samples through an auxiliary near-infrared laser beam, thereby providing a unique platform for probing soft matter systems. We demonstrate COLIS through ground tests on standard Brownian suspensions, and on protein, colloidal glasses, and gel systems similar to those to be used in future ISS experiments.

Background and Objectives: Subthreshold depression (StD) presents with depressive symptoms similar to major depressive disorder (MDD) but of lower intensity. Despite its milder form, StD is significantly prevalent in the older population, affecting up to 12.9%. StD is associated with adverse outcomes, such as an increased risk of MDD and mild cognitive impairment (MCI). Treating StD in older adults is challenging due to the limited efficacy and side effects of traditional antidepressants. As a result, clinicians often adopt a “watchful waiting” strategy, which increases the risk of StD progressing into MDD or MCI. Choline alphoscerate (α-GPC), a cholinergic drug, is indicated in the treatment of pseudodepression in the elderly, a condition that corresponds to the actual definition of StD. This review highlights the role of α-GPC in the treatment of StD in older subjects. Methods: A comprehensive review of preclinical and clinical studies was conducted, focusing on the efficacy of α-GPC in improving cognitive and behavioral functions in mental conditions and in modulating neurotransmitter systems involved in depression, such as dopamine and serotonin. Results: Evidence points to the therapeutic benefits of using α-GPC in StD as it acts on cholinergic dysfunction and cognitive impairment. Additionally, it may improve mood regulation and motivation, key factors in StD and in depressive disorders. These findings suggest that α-GPC may reduce the risk of progression from StD to MDD or MCI. Conclusions: α-GPC represents an effective and safe therapeutic option for the treatment of StD in the older population, improving clinical outcomes and enhancing the quality of life in this high-risk group.

This paper extends the standard Schumpeterian model of creative destruction by allowing the cost of innovation for followers to increase in their technological distance from the leader. This assumption is motivated by the observation that the more technologically advanced the leader is, the harder it is for a follower to leapfrog without incurring extra cost for using leader’s patented knowledge. Under this R &D cost structure, leaders have an incentive to play an “endpoint strategy\": they increase their technological advantage, counting on the fact that followers will eventually stop innovating—allowing leadership to prevail. We find that several results in the standard model fail to hold. In addition to the high -growth steady state in which only followers innovate, there now exists a second saddle-path-stable steady state: a low -growth steady state that features both leaders and followers innovating. A policy that increases monopolistic rents or extends parent duration can push the economy toward the low-growth steady state, causing, in some cases, irreversible harm to long-run growth.

The weak absorption of a laser beam generates in a fluid an inhomogeneous refractive index profile acting as a negative lens. This self-effect on beam propagation, known as Thermal Lensing (TL), is extensively exploited in sensitive spectroscopic techniques, and in several all-optical methods for the assessment of thermo-optical properties of simple and complex fluids. Using the Lorentz–Lorenz equation, we show that the TL signal is directly proportional to the sample thermal expansivity α, a feature allowing minute density changes to be detected with high sensitivity in a tiny sample volume, using a simple optical scheme. We took advantage of this key result to investigate the compaction of PniPAM microgels occurring around their volume phase transition temperature, and the temperature-driven formation of poloxamer micelles. For both these different kinds of structural transitions, we observed a significant peak in the solute contribution to α, indicating a decrease in the overall solution density—rather counterintuitive evidence that can nevertheless be attributed to the dehydration of the polymer chains. Finally, we compare the novel method we propose with other techniques currently used to obtain specific volume changes.

Financial innovation has increased diversification opportunities and lowered investment costs, but has not reduced the relative cost of active (informed) investment strategies relative to passive (less informed) strategies. What are the consequences? I study an economy with linear production technologies, some more risky than others. Investors can use low quality public information or collect high quality, but costly, private information. Information helps to avoid excessively risky investments. Financial innovation decreases incentives to collect private information and deteriorates the quality of public information, so that the economy invests more often in excessively risky technologies. This changes the business cycle properties and can reduce welfare by increasing the likelihood of “liquidation crises”.

This paper provides a novel dataset of time-varying measures on the degree of countercyclicality of fiscal policies for advanced and developing economies between 1980 and 2021. The use of time-varying measures of fiscal stabilization, with special attention to potential endogeneity issues, overcomes the major limitation of previous studies and allows the analysis to account for both country-specific as well as global factors. The paper also examines the key determinants of countercyclicality of fiscal policy with a focus on factors as severe crises, informality, financial development and governance. Empirical results show that (i) fiscal policy tends to be more countercyclical during severe crises than typical recessions, especially for advanced economies; (ii) fiscal countercyclicality has increased over time for many economies over the last two decades; (iii) discretionary and automatic countercyclicality are both strong in advanced economies but acyclical (at times procyclical) in low-income countries; (iv) fiscal countercyclicality operates primarily through the expenditure channel, particularly for social benefits; and (v) better financial development, larger government size and stronger institutional quality are associated with larger countercyclical effects of fiscal policy. Our results are robust to various specifications and endogeneity checks.

Aiming to reduce the power/mass requirements in satellite transponders and to reduce mission costs, joint amplification of multiple carriers using a single high-power amplifier (HPA) is being considered. In this scenario, a careful investigation of the resulting power efficiency is essential as amplification is nonlinear, and multicarrier signals exhibit enlarged peak-to-average power ratio. Thus, operating the amplifier close to saturation vastly increases signal distortion resulting in a severe degradation of performance, especially for higher order modulations. This paper proposes a reduced-complexity digital predistortion (DPD) scheme at the transmitter and a corresponding equalizer (EQ) at the receiver to mitigate these nonlinear effects. Scenarios include both the forward as well as the return links. In particular, the paper exploits the MIMO Volterra representation and builds on a basis pursuit approach using a LASSO (least absolute shrinkage and selection operator) algorithm to achieve an efficient basis representation, avoiding large computational complexity, to describe the selection of predistorter/equalizer model. The work further compares and contrasts the two mitigation techniques taking various system aspects into consideration. The gains in performance and amplification efficiency demonstrated by the use of DPD/ EQ motivate their inclusion in next-generation satellite systems.