Lodz University of Technology

The paper presents the problem of damage detection in steel girders. Static displacements at the selected point of the structure play the role of measured variables. Structural response signal decomposition is performed according to the Mallat pyramid algorithm, which is used to perform the discrete wavelet transform (DWT). This procedure allows us to quite well determine the location of structural damage. The geometry and the placement of any defective part of the structure may have a random character. It can be assumed that the random processes occurring in the broadly understood structure mechanics are Gaussian in nature. The first four probabilistic moments are estimated using three approaches independent: semi-analytical (SAM), perturbative (SPT), and Monte-Carlo simulations (MCS). The semi-analytical random approach seems to be the most optimal due to the necessary computation time. The incorporation of the mathematical stochastic apparatus into the classical (deterministic) analysis of the statics of the structure makes it possible to estimate the reliability measures of the analyzed girder.

The paper presents analyses aimed at determining how the spacing between legs of a steel lattice telecommunication tower affects displacements of its top, its natural frequency, and its self-weight. The critical characteristic of the results is that they were obtained for structures optimized with respect to the load-carrying capacity of their individual components. It was assumed that levels of effort should be kept between 85% and 95%. As far as engineering practice is concerned, the key conclusion is that a larger distance between the legs has a positive impact on the self-weight of the structure. It was demonstrated that a larger leg spacing is related to a smaller self-weight of the tower and thus a smaller quantity of material required. The proposed research and calculation method makes it possible to conclude that providing a larger distance between the legs while optimizing structural members with respect to their effort (preferably by means of an automated process) results in both higher bending stiffness and lower structure self-weight required.

This article is motivated by ensure the fire safety of the building and deeper understanding on special cements under elevated temperature loads. Knowledge about influence of high temperatures on calcium sulfoaluminate cement (CSA) based materials has crucial impact on ensuring the fire safety of the buildings. CSA based composites are dedicated to special usage in demanding infrastructure constructions. As there is no or insufficient evidence on the influence of heat on calcium sulfoaluminate materials, this article is motivated to extend current literature knowledge on CSA microstructures at higher temperatures up to 800oC. Recognising the effect of high temperature is particularly important given the significant differences between CSA and Ordinary Portland Cement (OPC). Evidence shows influence of mixture proportion on composite structure, filler-matrix bond, and matrix behaviour during temperature exposure. Obtained results might help in understanding phenomena occurring within material under temperature load and determine next research directions in this area.

One of the critical challenges in designing focusing mirrors based on monolithic high-contrast gratings (MHCGs) is the precise selection of geometrical parameters for each individual stripe, to ensure that the reflected light acquires the required phase shift for focusing at the focal point. However, achieving such precision in practice is hindered by fabrication effects, such as the proximity effect and etching lag, which can significantly alter the final structure. In this article, we numerically investigate the impact of random disruptions in stripe width, non-uniform etching depth caused by variations in air trench widths, and missing grating stripes on the reflectivity and light intensity at the focal point. The analysis is conducted for GaAs gratings designed for 980 nm and TM polarization. Our results show that variations in geometrical parameters degrade both reflectivity and light intensity at the focal point, with light intensity being more severely affected. Despite these variations, the MHCG focusing mirrors exhibit a high degree of resilience, maintaining robust optical performance disruptions that mimic realistic fabrication imperfections.

This work emphasizes the potential of multifunctional NIR-active coatings for medical devices to enhance diagnostic accuracy and therapeutic effectiveness and reduce infection rates.

The presented study investigates the impact of internal hydrophobization by using an organosilicon admixture based on triethoxyoctylsilane on the properties and durability of cement-based materials. Internal hydrophobization is an effective method for enhancing water resistance by incorporating hydrophobic agents directly into the cement matrix. The research evaluates the effects of this technique on cement hydration and microstructure of cement paste, as well as, capillary water absorption, compressive strength, resistance to freeze-thaw cycles and water penetration under pressure in concrete. The results indicate that the hydrophobic admixture influences cement hydration by reducing heat release and modifying pore structure. Compared to surface hydrophobization, internal hydrophobization in concrete provides long- lasting protection against water penetration, maintaining effectiveness even after 150 freeze-thaw cycles. However, excessive admixture dosage negatively affects mechanical properties, leading to excessive decrease in compressive strength. The study demonstrates that a carefully controlled dosage of hydrophobic admixture can significantly enhance the durability of concrete while minimizing negative impacts on the other properties of hardened material. These findings highlight the advantages of internal hydrophobization over traditional surface treatments, making it a promising approach for improving the longevity and performance of cementitious materials in aggressive environmental conditions.

A series of new Ag(i) and Cd(ii) hydrozanomide-based complexes have been prepared and studied. The synthesized compounds have undergone extensive spectroscopic and structural characterization, including F-AAS, FTIR, single crystal XRD and TGA analyses. Crystal structures of two representative complexes, 4 and 6, have revealed that the silver atom in complex 4 assumes a four-coordinate geometry with two ligands. Additionally, the stability of these complexes in DMSO has been determined using UV-vis spectroscopy. The biological activity of these metal complexes has been assessed, focusing on their antibacterial and anticancer properties against LN-229 and U87 cell lines. Among the tested compounds, silver-based complexes demonstrated significant antibacterial activity against a wide range of microorganisms. Moreover, cytotoxicity studies have shown that the metal complexes exhibit higher anticancer activity compared to their parent ligands. Notably, the Ag(i) complexes of L3, L4, and L5 have emerged as the most promising candidates for their selective toxicity against cancer cells, without harmful effects on normal human fibroblast cells. These findings highlight the potential of Ag(i) complexes as promising anticancer agents with selective toxicity and potent antibacterial properties.

Ticks spread to new habitats via wild mammals and birds, with urban green spaces potentially colonized through bird transportation. Rickettsia is a genus of bacteria that can cause diseases in humans and animals, which is often transmitted by ticks. This study investigated the presence of Rickettsia in the great tit (Parus major), a widespread Eurasian passerine bird, and in ticks attached to them. Samples were collected in three locations around Lodz, Poland: a suburban forest, an urban park, and green patches near the city center. Using Nested PCR (polymerase chain reaction), 73 samples of blood from birds and five ticks taken from great tits (attached to them) were tested for the presence of Rickettsia DNA. Six birds (8.2%) tested positive for Rickettsia spp., with detections across all locations. Sequencing confirmed the presence of Rickettsia helvetica, a known zoonotic species. None of the ticks tested positive for Rickettsia. These findings indicate that synanthropic bird species, like the great tit, may play a role in spreading Rickettsia bacteria into urban areas. This study highlights the potential importance of birds in the ecology of tick‐borne diseases in urbanized environments.

The charge carrier transport properties of two-dimensional benzimidazolium tin iodide perovskite ((Bn) 2 SnI 4 ) show a hopping mechanism for macroscopic transport and a band mechanism on the nanoscopic scale.

Semiempirical extended tight‐binding (GFN1‐xTB) and semilocal density functional theory (DFT)(Perdew–Becke–Ernzerhof (PBE)+D3) calculations are performed to evaluate the structural and electronic properties of five metal‐organic frameworks (MOFs): rigid MOF‐5(Zn), IRMOF(II)‐74(Mg), ZIF‐8(Zn), and flexible MIL‐53(Al) and MIL‐53(Fe). It is found that GFN1‐xTB exhibits a similar performance to that of DFT in terms of accuracy of lattice vector preservation. Structural integrity is further supported by the low average root‐mean‐square displacement (RMSD) of the atomic positions, which remains below 0.3 Å. Consequently, the textural properties are also well preserved by GFN1‐xTB, showing good agreement with those obtained from DFT. GFN1‐xTB molecular dynamics (MD) simulations exhibit structural stability and correctly predict structural responses to temperature, which is fully consistent with experimental results. In addition, based on MD trajectories, this study constructs time‐averaged X‐ray diffraction patterns that closely aligned with experimental data. More importantly, GFN1‐xTB performs exceptionally well at predicting the bandgap. Overall, GFN1‐xTB offers almost semilocal DFT accuracy with significantly higher computational efficiency, making it a valuable tool for describing the geometric, textural, dynamic, and selected electronic properties of MOFs.

The possibility of hydrogen (H2) production from sizing waste, specifically starch-based substrates, was investigated through dark fermentation. Modified starch substrates produced less (up to 54% without heating and 18% after heating) H2 than natural ones. However, heating modified starch samples led to 18% higher H2 production than unheated ones, suggesting that high temperatures activate more favorable metabolic pathways. The highest H2 production (215 mL/gTVS_substrate) was observed with unheated natural starch, where the classic butyric–acetic fermentation pathway predominated. This variant also generated the highest CO2 levels (250 mL/gTVS_substrate), confirming the correlation between H2 and CO2 production in these pathways. Modified starch substrates shifted fermentation towards fatty acid chain elongation, reducing CO2 production. The proportion of CO2 in the fermentation gases correlated strongly with H2 production across all variants. A decrease in total volatile solids (TVS) indicated effective organic matter conversion, while varying dissolved organic carbon (DOC) levels suggested different degradation rates. Nitrogen analysis (TN) revealed that the differences between variants were due to varying nitrogen processing mechanisms by microorganisms. These results highlight the potential of sizing waste as a substrate for bioH2 production and offer insights for optimizing the process and developing industrial technologies for bioH2 and other valuable products.

The objective of this study was to investigate the effects of the combined use of plant growth stimulants, including protein hydrolysates derived from animal waste and an azoxystrobin fungicide, during the cultivation of winter wheat ( Triticum aestivum L.). Three formulations were tested: collagen hydrolysate with sodium salicylate (1), collagen hydrolysate with titanium ascorbate (4a), and collagen and keratin hydrolysates with sodium salicylate (8). The collagen and keratin hydrolyzed extracts were obtained from tannery waste, specifically chromium leather waste, an important component of the leather industry’s circular economy. The experiments carried out in grow boxes demonstrated that the application of the new products in combination with fungicides resulted in an increased seedling length (9.6%, 10%, and 15.9% for preparations No. 1, 4a, and 8, respectively) and seedling fresh weight (8.5%, 7.9%, and 9% for preparations No. 1, 4a, and 8, respectively) compared to the control group without biostimulants. The use of preparation No. 8 also led to an increase in the nutrient and amino acids content of the plants. The prospective utilisation of protein biostimulants in crop production, encompassing those comprising salicylic acid and titanium ascorbate, has the potential to confer social, ecological and environmental benefits.

We show an existence and a uniqueness result for large solution to a degenerate and/or singular semilinear elliptic problem with its blow-up rate which is influenced by the degeneracy or singularity. It has been proved by showing, however of independent interest, an existence and a uniqueness of a weak solution of a degenerate and/or singular semilinear elliptic boundary value (nonhomogeneous) problem by penalty method for given weak sub- and supersolution.

The complexity of biological systems arises from the diversity and richness of interactions among their constituent units, which can be effectively modeled using complex network frameworks. Experimental studies have demonstrated that such interactions give rise to a wide range of emergent collective behaviors within biological populations. Notable examples include synchronization, chimera states, spiral waves, and other dynamic phenomena, all of which are closely linked to the proper or pathological functioning of biological systems. From a physiological perspective, understanding these emergent behaviors is crucial for uncovering the fundamental mechanisms underlying biological processes. Gaining insight into these dynamics not only advances basic scientific knowledge but also holds potential for developing novel diagnostic and therapeutic strategies for various diseases. In light of these developments, this special issue is dedicated to recent research related to collective behaviors in complex biological networks.

Sugar beet (Beta vulgaris L. subsp. vulgaris) is an important crop used not only in sugar production but also as the source of biogas and bioethanol, as a substrate in the petrochemical industry, and as a bio-resource for additional industrial and chemical feedstocks. Sugar beet is sensitive to environmental stress factors, including fungal infections such as Cercospora beticola (CLS—Cercospora leaf spot disease). Despite the introduction of plant cultivars with increased resistance to this disease, it causes a significant reduction in crop yield every year. The effect of infection is significant leaf loss in July and August, and the leaf rosette regeneration in September lasts until November. We examined three varieties of sugar beet with increased resistance to CLS. Using satellite images, we monitored the rate of leaf regeneration after CLS infection and studied in detail the gas exchange of plants, the efficiency of the photosynthetic apparatus, changes in the content of pigments and sugars in leaves, and sugar storage in roots. We showed for the first time that leaf regeneration after CLS infection seems independent of sugar accumulated in the roots. Sugar beetroot varieties were characterized by different strategies for managing sugar production and relocation. Moreover, the efficiency of CO2 assimilation and solar energy absorption were not correlated in time and space in sugar beet, which, in the context of autumn leaf regeneration and senescence, may also be an indication for earlier harvesting. Supplementary Information The online version contains supplementary material available at 10.1038/s41598-025-03968-8.

Despite affecting millions worldwide, major depressive disorder (MDD) remains a therapeutic challenge, with approximately one-third of patients failing to respond to standard treatments. The need for innovative, molecularly driven therapies has turned attention to ketamine and its enantiomers. While S-ketamine is clinically approved for treatment-resistant depression (TRD), it has various psychoactive side effects and potential for abuse. Hence, it is necessary to identify alternative compounds, such as R-ketamine, and their metabolites (e.g., 2S,6S-hydroxynorketamine and 2R,6R-hydroxynorketamine, collectively referred to as HNKs). Emerging evidence suggests that the pathophysiology of MDD involves two processes regulated by the unfolded protein response (UPR): endoplasmic reticulum (ER) stress and neuroinflammation. As such, they represent promising therapeutic targets. The study provides the first direct comparison of ketamine enantiomers and their metabolites in modulating ER stress and inflammatory signaling in human microglial cells (HMC3), which play key roles in neuroimmune communication. Both S-ketamine and R-ketamine, along with their metabolites, significantly reduced both the expression and protein levels of CHOP and GRP78—two critical UPR components—under tunicamycin-induced ER stress conditions. Additionally, the compounds significantly decreased IL-6 levels and, to a lesser extent, IL-8 levels in lipopolysaccharide (LPS)-stimulated microglia, indicating anti-inflammatory potential. Taken together, these findings highlight a novel glia-targeted mechanism by which ketamine and its metabolites modulate ER stress and neuroinflammation. CHOP and GRP78 appear to be stress-responsive molecular markers within the UPR pathway. These results justify further in vivo validation and support the development of antidepressants with fewer psychoactive effects.

The main aim of this article is to present the genealogy and prospects of the ecologically sustainable housing industry in Poland in lightweight construction such as wood, which is considered to be the most ecologically sustainable according to the Life Cycle Analysis methodology. The specific objective of the text is to present model solutions for Poland for sustainable housing industry. The research was carried out using historical analysis and a case study strategy. The article describes the pioneering ideals of housing development in lightweight technology, with designs examples from Polish architects of early modernism Leon Dietz d’Army, Helena and Szymon Syrkus and their inspirations drawn from Western Europe. The second part of the article presents modern methods for balancing the environmental impact of concrete, which currently dominates the Polish multi-family housing market. Sweden is indicated as a model for the development of the Polish housing industry in wooden technologies.