Influence of mictrostructure features on the corrosion behaviourof AZ91 alloy in chloride media

The influence of the microstructure of as-cast AZ91 magnesium alloy, which applied to solution annealing treatment and ageing treatment respectively, was evaluated in terms of its corrosion behaviour in 0.1 M NaCl solution at room temperature. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS) and the surface was characterized by scanning Kelvin probe force microscopy (SKPFM). The extent of corrosion damage was dependent on the microstructure. Surface potential maps indicated that, the surface potential of α-matrix is more positive than surface potential of β phase

Microwave-assisted solvothermal synthesis and characterization of nanostructured Cu2SnS3 architectures

The ternary Cu-Sn-S system, as an important I-IV-VI group semiconductor with small or mid band-gap, have attracted great attention owing to broad application in photovoltaic devices and H2 evolution under visible light irradiation. In this contribution, Cu2SnS3 nanostructures were successfully synthesized by microwave-assisted solvothermal route in a short time, using CuCl2.2H2O, SnCl2.2H2O and thiourea as starting chemicals. The influence of solvent on structure, morphology and optical properties of the as-prepared samples were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy, and Raman spectroscopy. The morphology of products can be tuned from flowerlike to sphere-like by using diethyleneglycol instead of ethyleneglycol as a solvent, while the cubic crystal structure remain unchanged

Neutrophil extracellular traps in urinary tract infection

BackgroundUrinary tract infections (UTI) are common types of bacterial infection in children. UTI treatment is aimed to prevent complications including hypertension, proteinuria, and progression to chronic kidney disease. Activated neutrophils release chromatin-based structures associated with antimicrobial proteins called neutrophil extracellular traps (NETs). We aimed to describe the role of NET-associated markers in children with UTI as well as the role of NETs formation in a mouse model of UTI.Materials and methodsMarkers of NETs including extracellular DNA (ecDNA), myeloperoxidase (MPO) and cathelicidin were analyzed in children with febrile UTI caused by E.coli (n = 98, aged 0.3–1.3 years) and in healthy controls (n = 50, 0.5–5.2 years). Moreover, an acute experimental model of UTI was performed on PAD4 knock-out mice with diminished NETs formation (n = 18), and on wild-type mice (n = 15).ResultsChildren with UTI had significantly higher urinary NETs markers including total ecDNA, nuclear DNA and mitochondrial DNA, altogether with MPO and cathelicidin. The concentrations of MPO and cathelicidin positively correlated with ecDNA (r = 0.53, p ≤ 0.001; r = 0.56, p ≤ 0.001, respectively) and the number of leukocytes in the urine (r = 0.29, p ≤ 0.05; r = 0.27, p ≤ 0.05, respectively). Moreover, urinary MPO was positively associated with cathelicidin (r = 0.61, p ≤ 0.001). In the experimental model, bacterial load in the bladder (20-fold) and kidneys (300-fold) was significantly higher in PAD4 knock-out mice than in wild-type mice.ConclusionHigher urinary NETs makers—ecDNA, MPO and cathelicidin and their correlation with leukocyturia in children with UTI confirmed our hypothesis about the association between NETs and UTI in children. Higher bacterial load in mice with diminished NETs formation suggests that NETs are not only a simple consequence of UTI, but might play a direct role in the prevention of pyelonephritis and other UTI complications

Cognitive impairment and biomarkers of gut microbial translocation in testicular germ cell tumor survivors

BackgroundSurvivors of testicular germ cell tumors (GCT) may suffer from late cognitive impairment. We hypothesized that disruption of intestinal barrier during chemotherapy and/or radiotherapy may be a contributing factor of cognitive dysfunction within the gut-blood-brain axis.MethodsGCT survivors (N = 142) from National Cancer Institute of Slovakia completed the Functional Assessment of Cancer Therapy Cognitive Function questionnaires during their annual follow-up visit at 9-year median (range 4-32). Biomarkers of gut microbial translocation and dysbiosis high mobility group box-1 (HMGB-1), lipopolysaccharide, d-lactate and sCD14 were measured from peripheral blood obtained during the same visit. Each questionnaire score was correlated with biomarkers. Survivors were treated with orchiectomy only (N = 17), cisplatin-based chemotherapy (N = 108), radiotherapy to the retroperitoneum (N = 11) or both (N = 6).ResultsGCT survivors with higher sCD14 (above median) had worse cognitive function perceived by others (CogOth domain) (mean ± SEM; 14.6 ± 0.25 vs 15.4 ± 0.25, p = 0.019), lower perceived cognitive abilities (CogPCA domain) (20.0 ± 0.74 vs 23.4 ± 0.73, p = 0.025) and lower overall cognitive function score (109.2 ± 0.74 vs 116.7 ± 1.90, p = 0.021). There were no significant cognitive declines associated with HMGB-1, d-lactate and lipopolysaccharide. Survivors treated with ≥ 400mg/m2 vs < 400mg/m2 of cisplatin-based chemotherapy had a higher lipopolysaccharide (567.8 μg/L ± 42.7 vs 462.9 μg/L ± 51.9, (p = 0.03).ConclusionssCD14 is a marker of monocytic activation by lipopolysaccharide and may also serve as a promising biomarker of cognitive impairment in long-term cancer survivors. While chemotherapy and radiotherapy-induced intestinal injury may be the underlying mechanism, further research using animal models and larger patient cohorts are needed to explore the pathogenesis of cognitive impairment in GCT survivors within the gut-brain axis

Sex differences in long-term effects of collagen-induced arthritis in middle-aged mice

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disorder with high prevalence among middle-aged women. Collagen-induced arthritis (CIA) is the most widely used animal model of RA, however, sex differences and long-term effects of CIA in mice are poorly described in the literature.Aim: Therefore, the present study aimed to analyze the long-term effects of CIA on the joints of middle-aged mice of both sexes and to describe potential sex differences.Materials and methods: CIA was induced in middle-aged DBA/1J mice by immunization with bovine type II collagen and complete Freund’s adjuvant. Saline was administered to control mice. Arthritis score assessment, plethysmometry, and thermal imaging of the joints were performed weekly for 15 weeks. Locomotor activity, micro-computed tomography, joint histology and biochemical analyses were performed at the end of the experiment.Results: Our results indicate a similar prevalence of arthritis in both sexes of mice—67% (8/12) of females and 89% (8/9) males with an earlier onset in males (day 14 vs. day 35). After the arthritis scores peaked on day 56 for males and day 63 for females, they steadily declined until the end of the experiment on day 105. A similar dynamics was observed in paw volume and temperature analyzing different aspects of joint inflammation. Long-term consequences including higher proteinuria (by 116%), loss of bone density (by 33.5%) and joint damage in terms of synovial hyperplasia as well as bone and cartilage erosions were more severe in CIA males compared to CIA females. There were no significant differences in locomotor activity between CIA mice and CTRL mice of any sex.Conclusion: This is the first study to describe the long-term effects of the CIA model in terms of sex differences in DBA/1J mice. Our results indicate sex differences in the dynamics, but not in the extent of arthritis. An earlier onset of arthritis and more severe consequences on joints, bones and kidneys were found in males. The underlying immune pathomechanisms responsible for the limited duration of the arthritis symptoms and the opposite sex difference in comparison to RA patients require further investigation

Vlivy podmínek výroby a skladování aminů na změny barevnosti

Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta metalurgie a materiálového inženýrství. Katedra (619) fyzikální chemie a teorie technologických pochod

JSCS-3233 Original scientific paper

Nickel(II) cyclohexylethyldithiocarbamate complexes with monodentate P-donor ligands in the coordination spher

Apoptosis-induced ectodomain shedding of hypoxia-regulated carbonic anhydrase IX from tumor cells: a double-edged response to chemotherapy.

BACKGROUND: Carbonic anhydrase IX (CA IX) is a tumor-associated, highly active, transmembrane carbonic anhydrase isoform regulated by hypoxia and implicated in pH control and adhesion-migration-invasion. CA IX ectodomain (ECD) is shed from the tumor cell surface to serum/plasma of patients, where it can signify cancer prognosis. We previously showed that the CA IX ECD release is mediated by disintegrin and metalloproteinase ADAM17. Here we investigated the CA IX ECD shedding in tumor cells undergoing apoptosis in response to cytotoxic drugs, including cycloheximide and doxorubicin. METHODS: Presence of cell surface CA IX was correlated to the extent of apoptosis by flow cytometry in cell lines with natural or ectopic CA IX expression. CA IX ECD level was assessed by ELISA using CA IX-specific monoclonal antibodies. Effect of recombinant CA IX ECD on the activation of molecular pathways was evaluated using the cell-based dual-luciferase reporter assay. RESULTS: We found a significantly lower occurrence of apoptosis in the CA IX-positive cell subpopulation than in the CA IX-negative one. We also demonstrated that the cell-surface CA IX level dropped during the death progress due to an increased ECD shedding, which required a functional ADAM17. Inhibitors of metalloproteinases reduced CA IX ECD shedding, but not apoptosis. The CA IX ECD release induced by cytotoxic drugs was connected to elevated expression of CA IX in the surviving fraction of cells. Moreover, an externally added recombinant CA IX ECD activated a pathway driven by the Nanog transcription factor implicated in epithelial-mesenchymal transition and stemness. CONCLUSIONS: These findings imply that the increased level of the circulating CA IX ECD might be useful as an indicator of an effective antitumor chemotherapy. Conversely, elevated CA IX ECD might generate unwanted effects through autocrine/paracrine signaling potentially contributing to resistance and tumor progression

Určenie modulu pružnosti osobných plášťov penumatík

Príspevok je zameraný na experimentálne určenie modulu pružnosti v ťahu dvoch rôzne starých osobných plášťov pneumatík. Vzorky sa získali narezaním v horizontálnom a vertikálnom smere z bočníc plášťov 17 a 4 ročných pneumatík. Modul v ťahu bol určený pomocou dynamicko-mechanickej analýzy (DMA). Na meranie bolo použité zariadenie Pyris Diamond od firmy Perkin Elmer. Experimentálne výsledky boli vyhodnotené a následne porovnané. Z výsledkov na prvý pohľad vidno výrazný rozdiel medzi hodnotami vzoriek v horizontálnom smere medzi dvoma použitými pneumatikami a aj v priebehu závislosti modulu od teploty

Influence of mictrostructure features on the corrosion behaviourof AZ91 alloy in chloride media

The influence of the microstructure of as-cast AZ91 magnesium alloy, which applied to solution annealing treatment and ageing treatment respectively, was evaluated in terms of its corrosion behaviour in 0.1 M NaCl solution at room temperature. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS) and the surface was characterized by scanning Kelvin probe force microscopy (SKPFM). The extent of corrosion damage was dependent on the microstructure. Surface potential maps indicated that, the surface potential of α-matrix is more positive than surface potential of β phase