University of Bucharest

Antibiotics are used primarily in human and veterinary medicine to treat various infections. They have also found applications in animal farms and aquaculture as growth promotors, with the aim of increasing food production. Their uncontrolled use can lead to increased bacterial resistance to antibiotics as well as other adverse effects. Unfortunately, these can reach and accumulate in the environment. Thus, their sensitive and selective detection from various matrices, using inexpensive and portable instruments, is becoming an increasing necessity. Electrochemical techniques are a viable alternative in this regard, and carbon paste electrodes (CPEs) present electrochemical and economic characteristics that recommend them as versatile devices for this purpose. Therefore, this paper is a comprehensive synthesis of the information presented in the last 10 years in the literature regarding CPEs developed for the analysis of antibiotics in different samples. Methods for obtaining different modified CPEs and their performances in detecting compounds belonging to different classes of antibiotics were discussed and priorities for future development were suggested. Through this review, researchers interested in the (electro)analysis of antibiotics will gain information about the advantages and limitations of using CPEs and the efforts made in the last decade to improve their performance.

The Iron Gates gorge, where the Danube River cuts through the Carpathian Mountains, represents a key corridor for understanding fluvial dynamics in Central and Southeast Europe. This study presents new insights into the formation and Quaternary evolution of the Lower Danube Gorge through high-resolution morphometric analyses and relative and absolute dating of terrace sequences within the gorge and the downstream alluvial plain.The earliest fluvial terraces, located at elevations between 270 and 320 m, mark the initial phase of river incision. Terraces T8 to T5 formed during this period and are correlated with mid–late Pliocene fine alluvial deposits and late Pliocene–early Quaternary coarser alluvial fan sediments downstream. The transition from upper (T8–T5) to lower terraces (T4–T1) in the gorge mirrors a comparable sequence in the Danube lowlands, where 7–8 alluvial terraces are identified, representing the shift from upper deltaic and alluvial fan deposits to the lower Danube plain.This longitudinal correlation highlights a regional change from lateral fluvial erosion and downstream vertical aggradation to dominant fluvial incision and terrace formation during the Middle–Late Quaternary, influenced by ongoing tectonic uplift and glacial–interglacial climate cycles. Fossil assemblages support a Late Pliocene–Early Quaternary age for the upper terraces, while newly obtained OSL dates for the younger terraces at the gorge exit (T3–T1) correspond to Marine Isotope Stages 3–1.The results reinforce the antecedent drainage model for the Danube at the Iron Gates, suggesting episodic incision superimposed on an actively uplifting landscape.Acknowledgments: This research was funded by the ChronoCarp project (Contract no. 760055/23.05.2023, project code CF 253/29.11.2022, PNRR-III-C9 2022-I8).

Chișinău, the capital of the Republic of Moldova, faces significant geohazard challenges due to its unique geological setting on loess-covered plateaus dissected by river valleys and ravines. Urban expansion and infrastructure development have intensified landslide susceptibility in this region, threatening residential areas, transportation networks, and critical infrastructure. This study presents a comprehensive analysis of urban landslides in Chișinău using Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) technique applied to Sentinel-1 satellite data spanning the last five years (2019-2025).The PS-InSAR methodology provides millimeter-level precision in detecting and monitoring ground deformation over time, making it particularly suitable for identifying slow-moving landslides and ground subsidence in urban environments. We processed ascending and descending Sentinel-1 SAR imagery to generate time-series deformation maps and identify persistent scatterers across the Chișinău metropolitan area. The analysis revealed multiple zones of significant ground displacement, with deformation rates ranging from -15 to +25 mm/year, concentrated primarily in areas with steep terrain, proximity to water courses, and urban development on historically unstable slopes.The susceptibility map derived from our analysis indicates high-risk zones in the northern and western sectors of Chișinău, particularly around suburb localities Vatra, Ghidighici, and Durlești, where loesslike deposits on valley slopes are subjected to both natural erosion processes and anthropogenic pressures. The southeastern areas near locality Bubuieci also show elevated landslide susceptibility, correlating with urban expansion into previously undeveloped terrain. Integration of PS-InSAR results with geological maps, digital elevation models, and land-use data enabled the development of a comprehensive landslide susceptibility assessment framework.Key findings reveal that ground deformation patterns in Chișinău exhibit strong seasonal variations, with accelerated movement during spring months corresponding to snowmelt and precipitation events. Urban infrastructure, including roads, buildings, and utilities, located within identified high-risk zones, shows structural damage consistent with slow-moving landslide activity. The study identifies critical infrastructure corridors, including major transportation routes (E583, E581) traversing the study area, that require enhanced monitoring and mitigation measures.Acknowledgements: This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS – UEFISCDI, project number 40PCBROMD within PNCDI IV.

Quartz is a ubiquitous, durable mineral abundant in most lithologies and in sedimentary systems. Its stability during weathering and diagenesis makes it a robust provenance tracer. Quartz optically stimulated luminescence (OSL) sensitivity and electron spin resonance (ESR) signals have been empirically proposed as indicators for sediment provenance based on differences in quartz sensitivity. Sensitivity is defined as luminescence produced per unit dose (Gray: Gy) per unit mass (mg). The mechanisms driving OSL sensitisation during weathering from source rocks remain an open question in the luminescence community. While it is largely believed to be acquired by earth surface processes, recent studies bring evidence that sensitisation processes depend on source geology. Moreover, most studies focus on quartz grains deposited in the sink and infer possible sources rock by clustering.The present study investigated a diverse suite of source rocks a wide range of geological settings, including granites, sandstones, volcanic and metamorphic rocks, and, where applicable, their derived sediments, independently dated from millions (Ma) to billions (Ga) of years. To understand the mechanism of OSL sensitivity we combined thermoluminescence (TL), OSL, ESR, cathodoluminescence (CL) and Raman spectroscopy measurements, with geochemical data obtained through laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Only in those quartzes that exhibited the [TiO4-Li+]0 paramagnetic centre in ESR, had notably high concentration of titanium and lithium impurities and had high blue emission in SEM-CL showed sensitisation following repeated cycles of laboratory dosing and bleaching. Samples lacking these centres did not show any laboratory OSL sensitisation by dosing and bleaching. We find a strong correlation of the degree of laboratory OSL sensitisation with the [TiO4-Li+]0 electron centre from ESR signal, and the titanium and lithium concentrations measured by LA-ICPMS. Our data on rocks of various ages and regions reinforce the idea that the potential for OSL sensitisation originates from specific lattice defect structures acquired by quartz during crystallisation. The results also highlight the role of Li⁺-ion impurities in forming paramagnetic centres such as [AlO₄/h]0 and [TiO4-Li+]0, advancing our understanding on interaction of radiations with specific defects in quartz.This study is funded by the European Research Council Consolidator Grant - PROGRESS, (ERC-CoG-101043356) awarded to Prof. Alida Timar-Gabor.

The adaptive nature of bacteria and their increasing resistance to conventional therapies demand alternative strategies to effectively control wound infections. At the wound site, dynamic biological processes are easily disrupted by microbial colonization, compromising normal healing. In this study, Zn-based nanoparticles composed of zinc oxide (ZnO) and zinc phosphate (Zn3(PO4)2) were synthesized via a green route using coconut milk and coconut water as biological media. Although ZnO formation via zinc hydroxide intermediates was initially targeted, structural analyses revealed a multiphase Zn-based system resulting from interactions between Zn2+ ions and naturally occurring phosphate species in the coconut-derived sources. The resulting material was incorporated into sodium alginate/poly(vinyl alcohol) hydrogel dressings, further enhanced with spirulina and aronia powders. Physicochemical characterization (XRD, SEM, EDS, FTIR), along with swelling and degradation studies, confirmed structural stability and appropriate hydrogel behavior. Antimicrobial testing against Staphylococcus aureus and Escherichia coli demonstrated a dominant antibiofilm effect of the Zn-based nanoparticles, while botanical additives exhibited moderate, time-dependent activity. Biological evaluation demonstrated good cytocompatibility toward human keratinocytes and murine macrophages, with botanical additives mitigating mild nanoparticle-induced cellular responses.

RATIONALEFollowing the 2023 February 6 disastrous earthquakes (Mw7.8 & Mw 7.7) that struck southern & central Türkiye, and northern & western Syria, an intense crust seismic sequence was triggered southwestern South Carpathians, Romania.Hosted by Gorj County, north Târgu Jiu city, its capital, the sequence started with twin unusual high magnitude earthquake (ML5.2 on February 13, and ML5.7 on February 14) and continued for months with more than 4000 seismic events.The area was known for quasi-continuous seismic activity, but surprising was the unusual intensity of earthquakes triggered and time extent of the sequence, which had a strong societal impact by scarring the population and provoking economic loss.The paper brings some geophysics inferred ideas about tectonic circumstances for triggering and maintaining the long-lasting seismic sequence. METHODObjective of the undertaken research was twofold: (i) to outline the overall tectonic setting of the area were the seismic sequence occurred, and (ii) to unveil more detailed structural circumstances of the largest magnitude earthquakes.The approach was mainly based on gravity data mining and interpretation. In a first step, various filters were applied to the complete Bouguer anomaly, like low pass filtering and upward continuation for separating regional and local effects, horizontal and vertical gradients, for emphasising the faults track, etc.In a second step, more advanced data processing, including inversion and forward modelling was conducted especially in areas of interest.For better interpreting/understanding the obtained results, data provided by other geophysical investigations, like e.g., geomagnetism, seismology, or seismic tomography were also employed. RESULTSAmong the main results it is worth mentioning: (i) overall location of seismicity along the northern flank of the westernmost segment of Getic Depression; (ii) earthquakes triggering mainly along faults striking WSW – ENE, as crustal echoes of the lithospheric contact between Moesian microplate (MoP) and Intra-alpine microplate (IaP); (iii) some earthquakes were also triggered along sub meridional faults.The most active area appears as a highly fractured zone, overlaying an underground mass excess with high magnetisation, echoed by a gravity high associated with a geomagnetic anomaly. The basalt dykes cropping out in the area suggest the in-depth presence of mafic/ultramafic intrusive. The assumption is supported by the existence of a hidden high velocity body unveiled by seismic tomography. FINAL REMARKSTo conclude, the unusual intense earthquakes of the Gorj sequence were likely triggered by a sudden increase of tectonic stress in the area due to an acceleration of the Black Sea microplate acting upon MoP. The NW push was WSW redirected along the transform contact between MoP and IaP. Among the others, the strain activated a seismic prone structure generated by the magmatic “diapirism” of an in-depth hidden mafic intrusive, likely belonging to Severine Nappe. The uplift of the mafic dome, had intensively fractured its crustal roof, creating a complex fault system along which earthquakes were triggered.

Neural regeneration requires an optimal environment, including structural, chemical, mechanical, and electrical properties. Alginate (Alg) and graphene oxide (GO) are promising biomaterials for nerve tissue engineering, as Alg provides biocompatibility and hydrogel formation, while GO enhances mechanical strength and conductivity. For this study, GO was synthesized using the modified Hummer’s method, and Alg–GO scaffolds with varying GO concentrations were developed. FTIR spectroscopy confirmed the successful incorporation of GO into the Alg matrix, while UV–Vis and photoluminescence analyses demonstrated GO-induced modifications of the optical properties. Thermal analysis revealed improved stability with increasing GO content, whereas swelling tests showed enhanced water uptake and retention. Conductivity measurements indicated a clear improvement in electrical conductivity, particularly at moderate GO concentrations. SEM imaging confirmed a homogeneous distribution of GO within the Alg matrix, with structural uniformity across all samples. Cytocompatibility was assessed using SH–SY5Y neuroblastoma cells through MTT, LDH, and LIVE/DEAD assays. All composites supported cell attachment, viability, and proliferation, with GO concentrations up to 6% promoting optimal cell growth without inducing cytotoxicity. In contrast, excessive GO content (9%) resulted in reduced proliferation, although biocompatibility was maintained. These results highlight the potential of Alg–GO scaffolds as promising candidates for neural tissue engineering. The findings demonstrate the potential of Alg–GO scaffolds as advanced biomaterials for regenerative medicine. Future research should focus on in vivo evaluations to confirm their therapeutic applicability.

The Johnson–Mehl–Avrami–Kolmogorov (JMAK) formalism provides a classical framework for describing polymer crystallization kinetics; its applicability under finite-domain confinement requires quantitative assessment. In this work, the influence of one-dimensional geometric restriction on cylindrical growth in polymer thin films is investigated using a stochastic Monte Carlo approach. The model considers site-saturated nucleation on randomly distributed cylindrical nanofibers with constant radial growth velocity under hard-wall boundary conditions. Crystallization kinetics were evaluated through automated segmented regression of the double-logarithmic JMAK representation. Under confinement, the Avrami plot departs from single-slope linearity and exhibits two successive quasi-linear regimes characterized by effective parameter pairs (n1, ln k1) and (n2, ln k2). The primary exponent n1 remains thickness-independent, consistent with early-stage radial expansion prior to boundary interaction. The secondary exponent n2 displays a non-monotonic dependence on reduced film thickness, reflecting the competing influence of wall-induced truncation and inter-fiber impingement on late-stage transformation. These results support a geometric interpretation in which finite-domain constraints modify effective growth dimensionality and provide a reproducible framework for analyzing dual-regime Avrami behavior in confined crystallization systems.

ABSTRACT Climate change is a serious issue that threatens environmental stability all around the world and puts more responsibility on the countries of the European Union (EU) to promote sustainable development goals. This paper examines the relationships between energy intensity, research and development (R&D) expenditure, industrialization, economic growth, and CO 2 emissions for EU countries from 1995 to 2022. The study uses novel panel econometric methods, such as the Method of Moment Quantile Regression (MMQR) and Dumitrescu and Hurlin causality tests, as well as other estimators to capture distributional heterogeneity and dynamic interdependencies among the variables, thereby enhancing robustness. The empirical results show that a high level of energy intensity increases CO 2 emissions across most quantiles, whereas R&D expenditure, industrialization, and economic growth reduce emissions, indicating that economic growth and environmental degradation move in opposite directions. Furthermore, one can find direct causal relationships in both directions between the main variables, indicating their interdependence in determining the environmental outcome. These findings indicate that the EU has been supported by structural change towards energy‐efficient, innovation‐driven economic activities in the mitigation of emissions. The study highlights the importance of strategic energy‐saving policies, continued investment in innovation, and environmentally responsive industrial policies to balance economic growth and environmental sustainability, thereby supporting the achievement of Sustainable Development Goals 7, 8, and 13.

The control systems for models described by non-commensurate fractional-order differential equations are based on their transformation into large commensurate-order systems, which impose difficulties in determining control laws. In this context, in this paper, a new control method for this class of systems is proposed. The results obtained are based on Lyapunov methods for differential equations with fractional exponents and on the application of the Yakubovich–Kalman–Popov lemma adapted for this class of systems. The stability criterion is presented as a frequency criterion and represented graphically by familiar frequency plots similar to those of the Nyquist or Popov type. If the parameters that define the model can be defined in a closed domain, the frequency criterion can be interpreted as “Popov’s circle criterion”. The two numerical applications present two important cases. The first studies the stability criterion in the case where the viscosity coefficients determine non-commensurate fractional-order exponents in the dynamic model of the system. The second example studies the complex problem of the human–machine system in which the human model imposes dynamics determined by non-commensurate fractional-order systems. The proposed investigation methods allow for a reduction in computational effort by several orders of magnitude for non-commensurate fractional-order systems, eliminate stability conditions that use matrix-based criteria for large-scale systems, and introduce standard frequency-domain criteria.