Objectives. Peripheral nerve injuries (PNI) represent the most common type of nervous system injuries, resulting in 5 million injuries per year. Current gold standard, autografts, still carry several limitations, including the inappropriate type, size, and function matches in grafted nerves, lack of autologous donor sites, neuroma formation, and secondary surgery incisions. Polymeric nerve conduits, also known as nerve guides, can help overcome the aforementioned issues that limit nerve recovery and regeneration by reducing tissue fibrosis, misdirection of regenerating axons, and the inability to maintain long- distance axonal growth. Polymer-based double-walled microspheres (DWMSs) are designed to locally and in a sustainable fashion deliver bioactive agents. Lysozyme is a natural antimicrobial protein that shares similar physical and chemical properties to glial cell line-derived neurotrophic factor, making it an ideal surrogate molecule to evaluate the release kinetics of encapsulated bioagent from polymeric biodegradable microspheres embedded in polycaprolactone and polycaprolactone/polyurethane blend nerve conduits. Approach. Lysozyme was encapsulated in poly(lactic-co-glycolic acid)/poly(L-lactide) DWMSs fabricated through a modified water-oil-water emulsion solvent evaporation method. Lysozyme-loaded DWMS were further embedded in PCL and PCL-PU based nerve guides constructed via polymer dip-coating and electrospinning method respectively. Lysozyme DWMS and nerve guides were imaged using scanning electron microscopy (SEM). Released lysozyme concentration was determined by using a colorimetric micro-BCA protein assay and spectrophotometric quantitation. Tensile and suture pull-out tests were utilized to evaluate the mechanical properties of both dip-coated and electrospun nerve guides, embedded and free of lysozyme DWMS. Main results. The study revealed significant distinctions in the lysozyme release profiles, and mechanical properties of the manufactured polymer nerve guides. Both PCL dip-coated and PCL/PU electrospun DWMS-embedded nerve guides revealed biphasic protein release profiles. PCL/PU electrospun and PCL dip-coated nerve guides released 16% and 29% of the total protein concentration within 72 h, plateauing at week 16 and week 8, respectively. SEM analysis of the nerve guides confirmed the homogeneity and integrity of the polymer nerve guides’ structures. The electrospun guides were found to be more flexible with a higher extension under stress bending, while the dip-coated PCL nerve guides displayed more rigid behavior. Significance. This study provides useful insights on how to optimize nerve guide design and fabrication to enhance recovery progress of PNI.

The coordination of vehicles is a crucial element of autonomous driving, as it enhances the efficiency, convenience, and safety of road traffic. In order to fully exploit the capabilities of such coordination, communication with high data rate and low latency is required. It can be reasonably argued that millimeter-wave (mm-wave) vehicle-to-vehicle (V2V) systems are capable of fulfilling the aforementioned requirements. Nevertheless, in order to develop a system that can be deployed in real-world scenarios and to gain an understanding of the various effects of mm-wave propagation, it is necessary to perform radio propagation measurements and to derive radio channel models from them across a range of scenarios and environments. To this end, we have conducted measurement campaigns at 60\,GHz in a variety of situations, including driving in a convoy, driving in opposite direction on a six-lane road, and overtaking. These measurements employ a channel sounder based on ReRoMA, a recently introduced concept that enables the real-time measurement of dynamic double-directional radio channels. The evaluations presented herein encompass key channel parameters, including the path loss (path loss coefficient of approximately 1.9), the root mean square (RMS) delay spread (within a range of 5\,ns to 110\,ns), the angular spreads (in a range of 0.05 to 0.4), the power distribution among multipath components, and the channel stationarity time (multiple seconds).

Abstract Mental health is deteriorating quickly and significantly globally post-COVID. Though there were already over 1 billion people living with mental disorders pre-pandemic, in the first year of COVID-19 alone, the prevalence of anxiety and depression soared by 25% worldwide. In light of the chronic shortages of mental health provider and resources, along with disruptions of available health services caused by the pandemic and COVID-related restrictions, technology is widely believed to hold the key to addressing rising mental health crises. However, hurdles such as fragmented and often suboptimal patient protection measures substantially undermine technology’s potential to address the global mental health crises effectively, reliably, and at scale. To shed light on these issues, this paper aims to discuss the post-pandemic challenges and opportunities the global community could leverage to improve society’s mental health en masse.

Hydropower is the world's most exploited renewable energy source. It provides a substantial, flexible, and reliable source of renewable energy, complementing other renewables like solar and wind power. Besides conventional hydropower potentials and technologies, the development of technologies for the exploitation of hidden hydropower potentials is an ongoing process. This paper presents the current state of hidden hydropower technologies and links them with possible applications in different hydropower potentials. Technologies and potential applications are structured within three main groups (pressurized systems, hydro storage, unpressurized systems), with their mutual interconnections analysed and displayed throughout the paper. The opportunity for the application of hidden hydropower technologies in different roles within the energy system is recognized through the concepts of off- and on-grid roles, the prosumer concept, and on-site measurement powering. This paper shows that hidden hydropower technologies could emerge as significant contributors to a smoother energy transition, especially with the prosumer and off-grid concepts.

Abstract Environmental, Social, and Governance (ESG) criteria have emerged as pivotal benchmarks for assessing corporate sustainability and ethical business practices. This study investigates the transformative role of small and medium-sized enterprises (SMEs) in advancing ESG practices, with a particular emphasis on countries aspiring to European Union membership. Employing a quantitative methodology through a survey questionnaire the research analyzes the challenges and opportunities associated with ESG implementation. Data collected from 51 SMEs across the Balkan region reveal substantial benefits of ESG integration, notably in enhancing operational efficiency and market reputation, with transparency and strategic planning identified as critical drivers. However, SMEs face significant obstacles such as complex regulatory frameworks, limited access to financing, and inadequate training resources. The article proposes targeted strategies to strengthen SME capacity, emphasizing investment in education, technological solutions, and partnerships with key stakeholders. By adopting ESG standards, SMEs not only contribute to sustainable development but also bolster their competitiveness and resilience in a rapidly evolving global market.

We consider deterministic nonlinear discrete-time systems whose inputs are generated by policy iteration (PI) for undiscounted cost functions. We first assume that PI is recursively feasible, in the sense that the optimization problems solved at each iteration admit a solution. In this case, we provide novel conditions to establish recursive robust stability properties for a general attractor, meaning that the policies generated at each iteration ensure a robust <inline-formula><tex-math notation="LaTeX">$\mathcal {KL}$</tex-math></inline-formula>-stability property with respect to a general state measure. We then derive novel explicit bounds on the mismatch between the (suboptimal) value function returned by PI at each iteration and the optimal one. However, we show by a counterexample that PI may fail to be recursively feasible, disallowing the mentioned stability and near-optimality guarantees. We therefore also present a modification of PI so that recursive feasibility is guaranteed a priori under mild conditions. This modified algorithm, called PI<inline-formula><tex-math notation="LaTeX">$^{+}$</tex-math></inline-formula>, is shown to preserve the recursive robust stability when the attractor is compact. In addition, PI<inline-formula><tex-math notation="LaTeX">$^{+}$</tex-math></inline-formula> enjoys the same near-optimality properties as its PI counterpart under the same assumptions.

In this paper, the author aims to address and problematize the adequacy of the criminal enforcement system in terms of the social adaptation and reintegration of convicted persons after serving a prison sentence, as well as to critically examine the potential problems and risks faced by this population. The humanization of the criminal enforcement system requires respect for the personal integrity and dignity of each individual, along with the implementation of appropriate programs and treatments aimed at behavior change and raising awareness about the harmful effects of criminal activity to achieve specific objectives. In this context, the legislator has prescribed a catalog of rights and established certain rules of conduct, particularly for specific categories, such as minors, individuals with mental disorders, persons with disabilities, and drug users. Special attention is given to juveniles due to their age, criminal-legal status, and the potential risk of recidivism (criminal reoffending), with a particular focus on sentencing and the execution of juvenile imprisonment. Accordingly, the paper centers on the social adaptation and reintegration of former offenders, with a particular focus on the real problems and challenges they face after serving their sentences and being released from correctional institutions.

Abstract Duplication of the vermiform appendix is a rare anomaly observed in patients undergoing appendectomy. A 27-month-old male toddler presented with a 9-day history of abdominal pain, vomiting, and diarrhea, progressing to an acute abdomen with signs of severe peritonitis. Intraoperative findings revealed a periappendicular infiltrate from a perforated vermiform appendix of the tenia coli type. A second, inflamed appendix was incidentally discovered in its typical location during the procedure. Vermiform appendix duplication presents a clinical challenge due to its rarity and potential for complications. According to the Cave–Wallbridge classification, this case represents Type B2, or the tenia coli variant, characterized by a perforated appendix originating at the tenia coli convergence and a smaller, secondary appendix in a retrocecal position. This case emphasizes the importance of thorough distal and proximal exploration during initial appendectomy when this anomaly is suspected, particularly in cases of Type B2.

Cancer progression is an evolutionary process driven by the selection of cells adapted to gain growth advantage. We present a formal study on the adaptation of gene expression in subclonal evolution. We model evolutionary changes in gene expression as stochastic Ornstein–Uhlenbeck processes, jointly leveraging the evolutionary history of subclones and single-cell expression data. Applying our model to sublines derived from single cells of a mouse melanoma revealed that sublines with distinct phenotypes are underlined by different patterns of gene expression adaptation, indicating non-genetic mechanisms of cancer evolution. Sublines previously observed to be resistant to anti-CTLA-4 treatment showed adaptive expression of genes related to invasion and non-canonical Wnt signaling, whereas sublines that responded to treatment showed adaptive expression of genes related to proliferation and canonical Wnt signaling. Our results suggest that clonal phenotypes emerge as the result of specific adaptivity patterns of gene expression. A record of this paper’s Transparent Peer Review process is included in the Supplemental Information.

Proton decay has been studied for decades now as one of the consequences of grand unified theories. Among those theories exists SU(5) theory, firstly postulated by H. Georgi and S. Glashow [1]. However, there were some problems with this theory such as mass degeneration and coupling unification [1-3]. This created a need for an extension of an original SU(5) model – a specific minimal SU(5) [4-5]. In this minimal SU(5) there is a viable parameter space with achievable gauge coupling unification. In this article, we present the process of gauge coupling unification for three mass scales of new physics states in this model, namely for 1 TeV, 10 TeV, and 100 TeV.