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There are many standards relating to the anti-slip properties of footwear and flooring. These standards describe the different test methods and procedures for determining the footwear and floor slip resistance in different conditions. In this paper authors systematize the standards in this field applied in the EU and in Serbia and cite the Serbian institutes which are certified for this type of testing. In addition, the authors have carried out an analysis and comparison of the tests that are defined in these standards, indicating their advantages and disadvantages. Importance of the static and kinetic friction testing in determining the anti-slip properties of footwear and flooring is specifically indicated. Considering the current standards in area of slip resistance of the footwear and floor covering authors have determined the testing conditions for laboratory measuring the friction forces of different floor and footwear materials. The laboratory measurement has carried out at Faculty of Mechanical Engineering in Niš. The measuring results and their analysis are presented in the paper, as well.

In most of the cases, the friction is considered as a negative side-effect concerning energy loss following every process of the power transmission. However, the friction has significant positive side effects, because it is an indispensable prerequisite for the movement of people, machines, transportation means and others. Efficiency of these movements mostly depends on the friction between rubber and different materials such as metals, concrete, earth, wood, plastic, etc. Certain standards relating to measurement and determination of the friction characteristics of rubber were established. However considering that tribology of the rubber is very complex problem, numerous studies around the world are conducted. This paper gives an overview of some of the existing standards and conducted researches in this area. The paper also provides an overview of theoretical and experimental studies of friction the rubber and the other materials, which are done at Faculty of Mechanical Engineering in Niš.

Rubber is a very flexible material with many desirable properties Which enable its broad use in engineering practice. Rubber or rubber-metal springs are widely used as anti-vibration or anti-shock components in technical systems. Rubber-metal springs are usually realized as a bonded assembly, however especially in shock absorbers, it is possible to realize free contacts between rubber and metal parts. In previous research it authors was observed that friction between rubber and metal in such case have a significant influence on the damping characteristics of shock absorber. This paper analyzes the development process of rubber or rubber-metal shock absorbers realized free contacts between the constitutive parts, starting from the design, construction, testing and operation, with special emphasis on the development of rubber-metal springs for the buffing and draw gear of railway vehicles.

(Педиатрическая фармакология. – 2008;5(5):127-130)

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Lactic acid bacteria (LAB) produce a broad spectrum of exopolysaccharides (EPSs), commonly used as texturizers in food products. Due to their potential contribution to LAB probiotic properties, like adhesion to human epithelial cells and competitive exclusion of pathogens from human intestinal epithelial cells, this study was focussed on the structural and functional characterization of the EPSs produced by two Limosilactobacillus fermentum strains - MC1, originating from mother's milk, and D12, autochthonous from Croatian smoked fresh cheese. Whole-genome sequencing and functional annotation of both L. fermentum strains by RAST server revealed the genes involved in EPS production and transport, with some differences in functionally related genes. EPSs were extracted from the cell surface of both bacterial strains and purified by size-exclusion chromatography. Structural characterization of the EPSs, achieved by chemical analyses and 1D and 2D NMR spectroscopy, showed that both strains produce an identical mixture of three different EPSs containing galactofuranose and glucopyranose residues. However, a comparison of the functional properties showed that the MC1 strain adhered better to the Caco-2 cell line and exhibited stronger antimicrobial effect against Salmonella enterica serovar Typhimurium FP1 than the D12 strain, which may be attributed to the potential bacteriocin activity of the MC1 strain., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Bioactive peptides (BPs) are molecules of paramount importance with great potential for the development of functional foods, nutraceuticals or therapeutics for the prevention or treatment of various diseases. A functional BP-rich dairy product was produced by lyophilisation of bovine milk fermented by the autochthonous strains Lactococcus lactis subsp. lactis ZGBP5-51, Enterococcus faecium ZGBP5-52 and Enterococcus faecalis ZGBP5-53 isolated from the same artisanal fresh cheese. The efficiency of the proteolytic system of the implemented strains in the production of BPs was confirmed by a combined high-throughput mass spectrometry (MS)-based peptidome profiling and an in silico approach. First, peptides released by microbial fermentation were identified via a non-targeted peptide analysis (NTA) comprising reversed-phase nano-liquid chromatography (RP nano-LC) coupled with matrix-assisted laser desorption/ionisation-time-of-flight/time-of-flight (MALDI-TOF/TOF) MS, and then quantified by targeted peptide analysis (TA) involving RP ultrahigh-performance LC (RP-UHPLC) coupled with triple-quadrupole MS (QQQ-MS). A combined database and literature search revealed that 10 of the 25 peptides identified in this work have bioactive properties described in the literature. Finally, by combining the output of MS-based peptidome profiling with in silico bioactivity prediction tools, three peptides ( 75 QFLPYPYYAKPA 86 , 40 VAPFPEVFGK 49 , 117 ARHPHPHLSF 126 ), whose bioactive properties have not been previously reported in the literature, were identified as potential BP candidates.

Background: In ulcerative colitis, the complexity of mucosal cytokine secretion profiles and how they correlate with endoscopic and clinical scores is still unclear., Methods: In this study, we collected fresh biopsies from UC patients to investigate which cytokines are produced in ex vivo culture conditions, a platform increasingly used for testing of novel drugs. Then, we correlated cytokine production with several scoring indices commonly used to assess the severity of the disease., Results: Increased levels of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, TNFα and IFNɣ were produced by biopsies of UC patients compared to non-IBD controls. Our results show a better correlation of cytokine levels with Mayo Endoscopic Subscore (MES) and Mayo score, than the more complex Ulcerative Colitis Endoscopic Index of Severity (UCEIS). Out of 10 measured cytokines, eight correlated with MES, six with Mayo score and only three with UCEIS, due to the partial increase in cytokine secretion observed in donors with UCEIS = 7-8. When we analysed individual subscores within the UCEIS, Vascular Network subscore showed a correlation similar to MES (7/10 cytokines), while Bleeding as well as Erosions and Ulcers subscores correlated with only 3/10 cytokines, similarly to the total UCEIS., Conclusions: Our findings suggest that choosing biopsies from donors with MES = 2-3 and UCEIS = 2-6 from areas with no bleeding and no superficial and/or deep ulcers could enable a deeper insight into the cytokine profile of the inflamed tissue and represent a better tool for studying potential therapeutic targets and evaluation of novel therapies., (© 2023 Stichting European Society for Clinical Investigation Journal Foundation.)

Research Background: Increasing awareness of the importance of nutrition in health promotion and disease prevention has driven to the development of foods for special medical purposes (FSMPs). In this study, the probiotic strain Lacticaseibacillus paracasei ssp. paracasei ( Lacticaseibacillus casei 431 ® ) was incorporated into FSMPs to develop an innovative product. The aim was to investigate the influence of the FSMP matrix on the specific probiotic properties of L. casei 431 ® in vitro ., Experimental Approach: A series of in vitro experiments were performed as part of the probiotic approach. After evaluation of antibiotic susceptibility profiles, functional properties such as survival under simulated gastrointestinal tract (GIT) conditions, bile salt deconjugation activities, cholesterol assimilation, antagonistic activity against spoilage bacteria and adhesion to Caco-2 cell line monolayers and extracellular matrix proteins were investigated., Results and Conclusions: The L. casei 431 ® strain, both the lyophilised strain and the strain isolated from the FSMP matrix, effectively survived the simulated adverse gastrointestinal conditions without significant effects of the food matrix. The effect of the FSMP matrix on the deconjugation activity of the bile salts of L. casei 431 ® was minimal; however, cholesterol assimilation was increased by 16.4 %. L. casei 431 ® had antibacterial activity against related lactic acid bacteria regardless of whether it was used in FSMPs or not. Conversely, the probiotic strain isolated from FSMP matrix had significantly higher inhibitory activity against six potential pathogens than the lyophilised culture. The autoaggregation ability of the L. casei 431 ® cells was not affected by the FSMP matrix. The adhesion of L. casei 431 ® bacterial cells to the extracellular matrix proteins was reduced after treatment with proteinase K, with the highest adhesion observed to laminin. The adhesion of L. casei 431 ® reduced the binding of E. coli 3014 by 1.81 log units and the binding of S . Typhimurium FP1 to Caco-2 cell lines by 1.85 log units, suggesting the potential for competitive exclusion of these pathogens., Novelty and Scientific Contribution: The results support the positive effect of the FSMP matrix on the specific probiotic properties of L. casei 431 ® , such as antibacterial activity, bile salt deconjugation and cholesterol assimilation, while the incorporation of this probiotic strain adds functional value to the FSMPs. The synergistic effect achieved by the joint application of L. casei 431 ® and innovative FSMP matrix contributed to the development of the novel formulation of an improved functional food product with added value., Competing Interests: CONFLICT OF INTEREST The authors declare no conflict of interest., (Authors.)

Lactiplantibacillus plantarum D13 shows antistaphylococcal and antilisterial activity, probably due to the synthesis of a presumptive bacteriocin with antibiofilm capacity released in the cell-free supernatant (CFS), whose inhibitory effect is enhanced by cocultivation with susceptible strains. An in silico analysis of the genome of strain D13 confirmed the pln gene cluster. Genes associated with plantaricin biosynthesis, structure, transport, antimicrobial activity, and immunity of strain D13 were identified. Furthermore, the predicted homology-based 3D structures of the cyclic conformation of PlnE, PlnF, PlnJ, and PlnK revealed that PlnE and PlnK contain two helices, while PlnF and PlnJ contain one and two helices, respectively. The potential of the strain to modulate the intestinal microbiota in healthy or dextran sulphate sodium (DSS)-induced colitis mouse models was also investigated. Strain D13 decreased the disease activity index (DAI) and altered the gut microbiota of mice with DSS-induced colitis by increasing the ratio of beneficial microbial species ( Allobaculum, Barnesiella ) and decreasing those associated with inflammatory bowel disease ( Candidatus Saccharimonas ). This suggests that strain D13 helps to restore the gut microbiota after DSS-induced colitis, indicating its potential for further investigation as a probiotic strain for the prevention and treatment of colitis.

Human milk not only provides a perfect balance of nutrients to meet all the needs of the infant in the first months of life but also contains a variety of bacteria that play a key role in tailoring the neonatal faecal microbiome. Microbiome analysis of human milk and infant faeces from mother-breastfed infant pairs was performed by sequencing the V1-V3 region of the 16S rRNA gene using the Illumina MiSeq platform. According to the results, there is a connection in the composition of the microbiome in each mother-breastfed infant pair, supporting the hypothesis that the infant's gut is colonised with bacteria from human milk. MiSeq sequencing also revealed high biodiversity of the human milk microbiome and the infant faecal microbiome, whose composition changes during lactation and infant development, respectively. A total of 28 genetically distinct strains were selected by hierarchical cluster analysis of RAPD-PCR (Random Amplified Polymorphic DNA-Polymerase Chain Reaction) electrophoresis profiles of 100 strains isolated from human milk and identified by 16S RNA sequencing. Since certain cellular molecules may support their use as probiotics, the next focus was to detect (S)-layer proteins, bacteriocins and exopolysaccharides (EPSs) that have potential as therapeutic biomolecules. SDS-PAGE (Sodium Dodecyl-Sulfate Polyacrylamide Gel Electrophoresis) coupled with LC-MS (liquid chromatography-mass spectrometry) analysis revealed that four Levilactobacillus brevis strains expressed S-layer proteins, which were identified for the first time in strains isolated from human milk. The potential biosynthesis of plantaricin was detected in six Lactiplantibacillus plantarum strains by PCR analysis and in vitro antibacterial studies. 1 H NMR (Proton Nuclear Magnetic Resonance) analysis confirmed EPS production in only one strain, Limosilactobacillus fermentum MC1. The overall microbiome analysis suggests that human milk contributes to the establishment of the intestinal microbiota of infants. In addition, it is a promising source of novel Lactobacillus strains expressing specific functional biomolecules.

Aim: To determine the frequency of common symptoms in long COVID and their effect on the quality of life, and to determine the factors contributing to a more severe long COVID., Methods: The study enrolled 266 patients who were either referred to long-COVID outpatient clinic or were inpatients undergoing rehabilitation. The data were collected between December 2020 and May 2021. We evaluated the symptoms experienced during acute and long COVID and comorbidities. Functional status was assessed with Post Covid Functional Status (PCFS)., Results: The final sample consisted of 261 patients. After acute COVID-19 period (>4 weeks), almost 80% of patients had impaired functional status. Only 21.5% reported no functional impairment (0 on PCFS scale). A higher PCFS score was associated with female sex (P<0.001) and oxygen therapy requirement during acute disease (P=0.001). However, it was not associated with having a pre-existing lung disease (P=0.749). Disease severity did not pose a risk for developing a more severe long COVID., Conclusion: Women were at greater risk for developing greater functional impairment in long COVID, although we have no explanation why. Malignant disease and hypertension also presented a risk factor for greater functional impairment. More studies are warranted to determine if patients with certain lung disease are more susceptible to long COVID.

This study aimed to define a consortium of lactic acid bacteria (LAB) that will bring added value to dried fresh cheese through specific probiotic properties and the synthesis of bioactive peptides (biopeptides). The designed LAB consortium consisted of three Lactobacillus strains: S-layer carrying Levilactobacillus brevis D6, exopolysaccharides producing Limosilactobacillus fermentum D12 and plantaricin expressing Lactiplantibacillus plantarum D13, and one Enterococcus strain, Enterococcus faecium ZGZA7-10. Chosen autochthonous LAB strains exhibited efficient adherence to the Caco-2 cell line and impacted faecal microbiota biodiversity. The cheese produced by the LAB consortium showed better physicochemical, textural and sensory properties than the cheese produced by a commercial starter culture. Liquid chromatography coupled with matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry (LC-MALDI-TOF/TOF) showed the presence of 18 specific biopeptides in dried fresh cheeses. Their identification and relative quantification was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using multiple reaction monitoring (MRM). The results also showed that their synthesis resulted mainly from β-casein and also α-S1 casein degradation by proteolytic activities of the LAB consortium. The designed LAB consortium enhanced the functional value of the final product through impact on biopeptide concentrations and specific probiotic properties.

Colorectal cancer is a malignant neoplasm which has an increasing incidence and represents a global public health problem. The majority of patients are diagnosed after the age of 50, and the risk of developing it over lifetime is 5%. Development of preventive, diagnostic and treatment methods has resulted in a significant reduction in mortality and other negative clinical outcomes. Precisely because of the efficient method of prevention and early detection of this disease, numerous countries, including Croatia, have organized national colorectal cancer screening and monitoring programs. However, these programs are primarily organized for the population with the usual, i.e. average risk of developing colorectal cancer. High-risk groups include persons with endoscopically detected and removed colon polyps, persons surgically treated for colon cancer, persons with a positive family history of colorectal cancer, persons with inflammatory bowel diseases, individuals and families with hereditary disorders or genetic mutations that increase the risk of this disease several fold, persons with acromegaly, and patients who have undergone ureterosigmoidostomy. Recommendations for the detection and monitoring of high-risk groups are often not defined clearly, and some of the existing ones are based mostly on scarce scientific evidence. It is commonly accepted that screening in high-risk groups should start at an earlier age, with shorter intervals between follow-ups. The basic diagnostic method for screening and monitoring in these patient groups is endoscopic monitoring, or colonoscopy. The aim of this review paper is to present the characteristics of the abovementioned risk groups and provide clear screening recommendations.

Dyspepsia is a disorder characterized by dyspeptic symptoms which are located in the epigastrium and related to digestion of food in the initial part of the digestive system. In functional dyspepsia, unlike organic dyspepsia, there is no underlying organic disease that would cause dyspeptic symptoms. Immune and mucosal function changes, gastric dysmotility, different composition of the gastrointestinal microbiota, and altered central nervous system processing are considered responsible for the onset of the disorder. The diagnosis is based on history, clinical presentation, and exclusion of other organic diseases of the gastrointestinal tract manifested by dyspeptic symptoms. Therapy includes eradication of Helicobacter pylori infection, proton pump inhibitors, prokinetics, neuromodulators, and herbal preparations. Unfortunately, in some patients, this therapy leads to little or no improvement. The prevalence of functional dyspepsia is increasing. It has become one of the more common gastroenterological diagnoses. In order to reduce the costs associated with the diagnosis and treatment of the disorder itself, its mechanisms need to be fully elucidated and thus enable finding appropriate therapy for all patient subgroups.