Universitatea Națională de Știință și Tehnologie Politehnica București

In this paper, we introduce a new time-fractional-frequency transform, named $\alpha$-windowed Fourier transform ($\alpha$-WFT) $G^\alpha _\phi : L^2({\mathbb {R}}^2)\rightarrow L^2({\mathbb {R}}^2)$, where $\alpha$ is a fractional parameter and $\phi \in L^2({\mathbb {R}}){\setminus }\{0\}$ is a window function. We investigate the fundamental properties of this generalized windowed Fourier transform. Then, we establish some Heisenberg-type inequality for the $\alpha$-WFT in the fractional Fourier domain and we also give a result concerning Lieb’s inequality for $\alpha$-WFT. Furthermore, we study a relationship between the $\alpha$-WFT and a version of the fractional Wigner distribution introduced for this purpose. In the end, we introduce the semi-discrete and discrete version of the $\alpha$-WFT.

In the present study, the bacterial symbionts of two species of oak aphid, Thelaxes dryophila and Tuberculatus annulatus were tested as indicators between naturally and artificially regenerated oak forests. In total, 195 bacterial taxa were identified using the Ion Torrent PGM system. Here, we report for the first time differences in bacterial symbiont diversity between oak forests natural and artificial regeneration sites, and aphid species. Differences in the abundance of the primary obligate endosymbiont Buchnera aphidicola were also detected between the two study aphid species. In the ant attended Thelaxes dryophila, the species was found to harbour a higher density of the facultative symbionts Serratia symbiotica and Wolbachia, while in the non-ant attended Tuberculatus annulatus, the dominant facultative symbionts were Hamiltonella and Rickettsia. In addition, we report the presence of Serratia marcescens and Enterobacter cloacae as symbionts of Thelaxes dryophila and Shigella boydii as a symbiont of Tuberculatus annulatus. We conclude that the two aphid species harbour different facultative symbionts between oak forest regeneration types; these results might have importance in oak forest pest management via aphid adaptation through their endosymbions.

In this paper, the influence of Ti-TiC satellite powder obtained in situ by the CVD method on the microstructure, properties, and residual stress of titanium cold-sprayed coatings was studied. A commercially available titanium powder was subjected to a satelliting process using the CVD process, where TiC particles were in situ formed on titanium granules. Then, a powder mixture of pure Ti and 20 wt.% of Ti-TiC satellite powder was obtained. Cold spray coatings of Ti-(Ti-TiC) sat powder mixtures were applied to Ti6Al4V substrates with carrier gas temperatures of 900 °C and 1100 °C. The coating characterization included microstructural analyses by SEM, hardness measurements, determination of Young’s modulus, phase composition by XRD, and residual stress measurements. Cross-sectional analysis revealed good cohesion between Ti and TiC during the satelliting process, which survives coating deposition. Moreover, the higher spraying temperature resulted in TiC crystallite size reduction, higher hardness, and Young’s modulus, decreasing linear and shear stresses.

Digital Twins, represents an innovative approach consisting of real-time digital replicas of physical entities. This innovative concept has already many applications in Industry, automotive, business environment and is also transforming the healthcare industry. Digital Twins have the potential to provide comprehensive models of individual patients, hospital facilities, and medical processes, integrating data from various sources such as electronic health records, wearable devices, and imaging systems. This paper discusses Digital Twin models and their application in healthcare, focusing on care coordination, treatment planning and hospital management development.

Background/Objectives: This study evaluates the perceptions of pharmacists in Romania regarding self-medication, a growing practice with significant implications for public health and sustainable development. The main objective is to analyze the role of pharmacists in managing self-medication and educating the public on rational medication use. Methods: A descriptive and exploratory methodology was employed, using a questionnaire administered to 300 pharmacists from various regions in Romania between March and April 2024. The data analysis included Chi-square tests and linear regression to identify predictive factors. Results: The findings reveal a direct correlation between the frequency of self-medication and the perceived severity of conditions, with self-medication being more common for minor ailments. Experienced pharmacists are less likely to encourage self-medication. Public education on the risks of self-medication significantly reduces the prevalence of this practice. Conclusions: Self-medication, without proper regulation and education, risks becoming unsustainable. Targeted informational campaigns and educational programs tailored to diverse demographic groups are essential. Pharmacists play a critical role in promoting safe and responsible medication use.

Over time, the notion of the environment has evolved to receive new meanings, some of which are explained here. We can distinguish the natural environment, which theoretically works without the massive intervention of man, and the built environment that is built by the massive intervention of man. The natural environment of interest to man consists of the lithosphere and atmosphere. Pollutant is any solid substance, liquid, in gaseous or vaporous form or as energy (electromagnetic, ionizing, thermal, sound or vibrating radiation) which, introduced into the environment, alters the balance of its constituents and of living organisms and damages material property. The principles of environmental rules and regulations are based on objective conditionality in the sense that the norm is in line with the nature, history and will of the majority of society and consistency in regulation. Environmental laws are distinguished by their way of complex approach. Man is essentially a creation of nature so there was and will be an interaction between man and the environment. Usages and norms that relate to the links between man and his surrounding nature are the first form of regulation of the relations between human beings and the natural environment.

The skin, known as the largest organ of the body, is essential for maintaining physiological balance and acts as a barrier against the external environment. When skin becomes damaged and wounds appear on the skin’s surface, a complex healing process, involving multiple types of cells and microenvironments, take place. Selecting a suitable dressing for a wound is crucial for accelerating healing, reducing treatment costs, and improving the patient’s overall health. Starting from natural resources such as perch skin (P. fluviatilis), this article aims to develop biocompatible materials for regenerative medicine from collagen in the form of gels/gelatines. The extracted gels were physical/chemical and structurally analyzed. In order to obtain collagen scaffolds for wound healing, the extracted collagen gels from perch skin were further freeze-dried. The ability of these scaffolds is essential for controlling moisture levels during wound healing; therefore, it was necessary to investigate the samples’ ability to absorb water. The assessed collagen-based scaffolds were microbiologically tested, and their biocompatibility was investigated by incubating human adult dermal fibroblasts. The outcomes reveal an innovative path for the production of biomaterials used in wound healing, starting from collagen derived from marine sources.

In line with the ongoing advancement of high-performance materials that are multifunctional and environmentally friendly, this paper provides an overview of recent developments in lightweight and ultra-lightweight multifunctional materials. We primarily examine the various types of low-density multifunctional materials, their production techniques, and their applications within the context of a sustainable future. From a structural point of view, ultra-light materials are classified into three main groups: aerogels, foam, and micro/ nanolattice. In terms of composition, they can be derived from ceramic, metallic, or polymeric materials. This overview pays particular attention to silica, carbon and composite aerogels, as well as metal, ceramic (carbon), and polymer foams.

Spectrum sensing (SS) based on energy detection (ED) is a simple yet effective approach to detect the presence of unknown signals that are active in a specific band of frequencies. The classical ED (CED) algorithm uses the value of the energy detected in the current sensing slot as test statistic and has a fixed threshold, but improved signal detection performance is possible by modifying the test statistic and/or the detection threshold. In this paper we propose a novel ED algorithm for SS that considers a binary activity model for the signal to be detected and combines the use of an average energy test statistic with an adaptive decision threshold for improved detection performance. We present the analytical characterization of the proposed test statistic in terms of its mean and variance, and derive the expressions corresponding to the correct decision probability (CDP) and false alarm probability (FAP). Using the derived CDP and FAP expressions, we also determine the detection thresholds that yield desired values for the false alarm and missed detection probabilities. The proposed algorithm is illustrated with numerical results obtained from simulations, which confirm our theoretical findings and also show that the algorithm outperforms alternative adaptive ED algorithms.

In this research, the effects of heating cycles that are performed correctly and excessively—well above the limitations given by the steel manufacturer—on flame straightening are assessed and analyzed. The paper focuses on the microstructural changes caused by the overheating during the flame straightening process. To create geometrical changes in a metal construction, a tiny section of the element or structure is heated to the straightening temperature during the flame straightening process. Strenx® 960 is typically produced through a combination of thermomechanical rolling and quenching and tempering, resulting in a fine-grained martensitic or bainitic microstructure. These processes are designed to achieve a balance of high strength and good toughness. The microstructural changes associated with different working conditions in the case of welding include HAZ softening and grain growth. The study aimed to highlight the influence of flame hardening on the microstructure of the material.

Recent studies underscore the role of gut and oral microbiota in influencing neuroinflammation through the microbiota–gut–brain axis, including in Alzheimer’s disease (AD). This review aims to provide a comprehensive synthesis of recent findings on the involvement of gut and oral microbiota in the neuroinflammatory processes associated with AD, emphasizing novel insights and therapeutic implications. This review reveals that dysbiosis in AD patients’ gut and oral microbiota is linked to heightened peripheral and central inflammatory responses. Specific bacterial taxa, such as Bacteroides and Firmicutes in the gut, as well as Porphyromonas gingivalis in the oral cavity, are notably altered in AD, leading to significant changes in microglial activation and cytokine production. Gut microbiota alterations are associated with increased intestinal permeability, facilitating the translocation of endotoxins like lipopolysaccharides (LPS) into the bloodstream and exacerbating neuroinflammation by activating the brain’s toll-like receptor 4 (TLR4) pathways. Furthermore, microbiota-derived metabolites, including short-chain fatty acids (SCFAs) and amyloid peptides, can cross the blood-brain barrier and modulate neuroinflammatory responses. While microbial amyloids may contribute to amyloid-beta aggregation in the brain, certain SCFAs like butyrate exhibit anti-inflammatory properties, suggesting a potential therapeutic avenue to mitigate neuroinflammation. This review not only highlights the critical role of microbiota in AD pathology but also offers a ray of hope by suggesting that modulating gut and oral microbiota could represent a novel therapeutic strategy for reducing neuroinflammation and slowing disease progression.

Rheumatoid arthritis (RA) patients face different health challenges when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) than the general population, due to both their immunocompromised state and the immunosuppressive therapies they receive. This systematic literature review, which follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) paradigm, explores the interactions between RA and SARS-CoV-2 infection, focusing on immunologic issues, disease management, vaccination, and adverse outcomes. In order to obtain the most relevant information, we systematically reviewed the specific literature from 1 January 2021 to 31 December 2023, based on the PRISMA method, by which we eventually selected 35 eligible articles, to which we added other ISI-indexed studies to enrich our results further. Consequently, we performed a funnel analysis to evaluate the potential for publication bias. Firstly, the data collected revealed the impact of the pandemic on RA diagnoses and the fear of face-to-face medical consultations that delayed adequate treatment. Secondly, cardiovascular and metabolic comorbidities increase the risk of prolonged COVID-19 symptoms, hospitalization, and severe COVID-19 outcomes for RA patients. With respect to immunosuppressive treatment used to control RA, it was observed that glucocorticoids (especially high-dose usage) and Rituximab (RTX) predispose the patients to poor SARS-CoV-2 outcomes, as opposed to Baricitinib and interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) inhibitors. COVID-19 vaccination has proven effective and generally safe for RA patients in some studies, although therapies with Methotrexate (MTX), Abatacept (ABA), and RTX have been associated with impaired vaccine immune response. This systematic literature review brings updated and thorough information with respect to the immunological, clinical, and management of a complex immune-mediated inflammatory disease (IMID) like RA in the setting of COVID-19 and underlines the challenges faced by this group of patients. The lessons learned can be extended beyond the pandemic in shaping a more informed and compassionate healthcare system and offering long-term medical care for patients with RA.

The first measurement of the multiplicity dependence of intra-jet properties of leading charged-particle jets in proton–proton (pp) collisions is reported. The mean charged-particle multiplicity and jet fragmentation distributions are measured in minimum-bias and high-multiplicity pp collisions at center-of-mass energy $\sqrt{s}$ s = 13 TeV using the ALICE detector. Jets are reconstructed from charged particles produced in the midrapidity region ( $|\eta | < 0.9$ | η | < 0.9 ) using the sequential recombination anti- $k_{\textrm{T}}$ k T algorithm with jet resolution parameters R = 0.2, 0.3, and 0.4 for the transverse momentum ( $p_\textrm{T}$ p T ) interval 5–110 GeV/ c . The high-multiplicity events are selected by the forward V0 scintillator detectors. The mean charged-particle multiplicity inside the leading jet cone rises monotonically with increasing jet $p_\textrm{T}$ p T in qualitative agreement with previous measurements at lower energies. The distributions of jet fragmentation function variables $z^{\textrm{ch}}$ z ch and $\xi ^{\textrm{ch}}$ ξ ch are measured for different jet- $p_\textrm{T}$ p T intervals. Jet- $p_\textrm{T}$ p T independent fragmentation of leading jets is observed for wider jets except at high- and low- $z^{\textrm{ch}}$ z ch values. The observed “hump-backed plateau” structure in the $\xi ^{\textrm{ch}}$ ξ ch distribution indicates suppression of low- $p_\textrm{T}$ p T particles. In high-multiplicity events, an enhancement of the fragmentation probability of low- $z^{\textrm{ch}}$ z ch particles accompanied by a suppression of high- $z^{\textrm{ch}}$ z ch particles is observed compared to minimum-bias events. This behavior becomes more prominent for low- $p_\textrm{T}$ p T jets with larger jet radius. The results are compared with predictions of QCD-inspired event generators, PYTHIA 8 with Monash 2013 tune and EPOS LHC. It is found that PYTHIA 8 qualitatively reproduces the jet modification in high-multiplicity events except at high jet $p_\textrm{T}$ p T . These measurements provide important constraints to models of jet fragmentation.