14 research outputs found

    Comparative Laser Spectroscopy Diagnostics for Ancient Metallic Artefacts Exposed to Environmental Pollution

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    Metal artworks are subjected to corrosion and oxidation processes due to reactive agents present in the air, water and in the ground that these objects have been in contact with for hundreds of years. This is the case for archaeological metals that are recovered from excavation sites, as well as artefacts exposed to polluted air. Stabilization of the conservation state of these objects needs precise diagnostics of the accrued surface layers and identification of original, historical materials before further protective treatments, including safe laser cleaning of unwanted layers. This paper presents analyses of the chemical composition and stratigraphy of corrosion products with the use of laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy. The discussion of the results is supported by material studies (SEM-EDS, XRF, ion-analyses). The tests were performed on several samples taken from original objects, including copper roofing from Wilanów Palace in Warsaw and Karol Poznański Palace in ŁódŸ, bronze decorative figures from the Wilanów Palace gardens, and four archaeological examples of old jewellery (different copper alloys). Work has been performed as a part of the MATLAS project in the frames of EEA and Norway Grants (www.matlas.eu) and the results enable the comparison of the methodology and to elaborate the joint diagnostic procedures of the three project partner independent laboratories

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    Characterization of Laser Cleaning of Artworks

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    The main tasks of conservators of artworks and monuments are the estimation and analysis of damages (present condition), object conservation (cleaning process), and the protection of an object against further degradation. One of the physical methods that is becoming more and more popular for dirt removal is the laser cleaning method. This method is non-contact, selective, local, controlled, self-limiting, gives immediate feedback and preserves even the gentlest of relief - the trace of a paintbrush. Paper presents application of different, selected physical sensing methods to characterize condition of works of art as well as laser cleaning process itself. It includes, tested in our laboratories, optical surface measurements (e.g. colorimetry, scatterometry, interferometry), infrared thermography, optical coherent tomography and acoustic measurements for “on-line” evaluation of cleaning progress. Results of laser spectrometry analyses (LIBS, Raman) will illustrate identification and dating of objects superficial layers

    Direct laser interference lithography in periodical treatment of biomaterials

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    The paper presents the results of research on modern laser micromachining technology based on utilization of the interference field of high energy, pulse laser beams. The influence of radiation polarization on a pattern shape in an interference image has been analyzed theoretically. Values of laser ablation threshold for titanium and diamond-like coatings were determined experimentally. The particular advantages of the direct laser interference lithography method have been shown in a series of tests devoted to the periodical surface topography modification, including creation of hierarchical structures with different periods and feature dimensions. Another trial of tests has confirmed also the application potential of this technique in shaping of implant surfaces as well as preparation of scaffolds for cells and tissues culturing in bioengineering.[b]Keywords[/b]: materials engineering, laser micromachining, interference lithography, titanium alloys, diamond-like carbon layers, biomaterial

    Bezpośrednia laserowa litografia interferencyjna w periodycznej obróbce biomateriałów

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    The paper presents the results of research on modern laser micromachining technology based on utilization of the interference field of high energy, pulse laser beams. The influence of radiation polarization on a pattern shape in an interference image has been analyzed theoretically. Values of laser ablation threshold for titanium and diamond-like coatings were determined experimentally. The particular advantages of the direct laser interference lithography method have been shown in a series of tests devoted to the periodical surface topography modification, including creation of hierarchical structures with different periods and feature dimensions. Another trial of tests has confirmed also the application potential of this technique in shaping of implant surfaces as well as preparation of scaffolds for cells and tissues culturing in bioengineering.[b]Keywords[/b]: materials engineering, laser micromachining, interference lithography, titanium alloys, diamond-like carbon layers, biomaterial

    Bacterial lysate therapy for the prevention of wheezing episodes and asthma exacerbations: A systematic review and meta-analysis

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    Wheezing and asthma are a growing cause of morbidity in children and adults. Treatment is aimed at prevention of disease exacerbations and preservation of lung function. Respiratory viruses are involved in ∼40–60% of exacerbations. Bacterial lysates prevent recurrent respiratory tract infections and might reduce exacerbations. Moreover, immunomodulatory effects have been observed in human and animal studies. Here we aimed to assess the effects of bacterial lysate therapy on preschool wheezing episodes and asthma exacerbation frequency. We performed a systematic literature review based on the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and a meta-analysis using Cochrane Review Manager. Out of 2016 retrieved articles, 22 studies were included, of which five provided sufficient data for a meta-analysis. The use of bacterial lysates showed a decrease of both wheezing episodes (mean difference −2.35 (−3.03– −1.67), p<0.001) and asthma exacerbations in children (mean difference −0.90 (−1.23– −0.57), p<0.001). Additionally, antibiotic use was reduced, and the duration of wheezing episodes was also decreased. No data for adults with asthma are currently available. The immunomodulatory effect seems to be dependent on increased T-helper (Th)1-cell activation and Th2-cell suppression. These favourable effects of bacterial lysates indicate that they show promise as add-on therapy in preschool wheezing and childhood asthma

    Preliminary Research on the Effect of Hyperbaric Oxygen Therapy in Patients with Post-COVID-19 Syndrome

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    Negative consequences and medical complications of COVID-19 can persist for up to several months after initial recovery. These consequences can include stroke, diabetes, decreased lung diffusing capacity, sleep apnea, pulmonary fibrosis, arrhythmia, myocarditis, fatigue, headaches, muscle aches, heart rate fluctuations, sleep problems, memory problems, nervousness, anxiety, and other neurological disorders. Thirty-one patients who reported symptoms related to previous COVID-19 disease of both sexes were enrolled in the initial program. The patients underwent compression sessions in a multiplace hyperbaric chamber. Each patient underwent a cycle of 15 compressions. Before the first session, each participant completed a venous blood gas test, a Fullerton test, and two spirometry tests (one before the Fullerton test and one after the test). Patients completed psychotechnical tests, a questionnaire on quality of life (Polish version of EQ-5D-5L), and a questionnaire on specific symptoms accompanying the disease and post-infection symptoms. The results showed significant improvements in areas such as quality of life, endurance and strength, some spirometric parameters, the anion gap and lactate levels, working memory, and attention in the group of treated patients. In contrast, there were no changes in pH, pO2, pCO2, glucose, and excess alkaline values. A follow-up interview confirmed that the beneficial effects were maintained over time. Considering the results obtained, including the apparent improvement in the patient’s clinical condition, it can be concluded that the use of 15 compression sessions was temporarily associated with a noticeable improvement in health and performance parameters as well as improvement in certain blood gas parameters
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