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Abstract: While one of the biggest problems we are facing today is water scarcity, enormous quantities of water are still being used in irrigation. If contaminated, this water can act as an effective pathway for the spread of disease-causing agents, like viruses. Here, we present a novel, environmentally friendly method known as cold atmospheric plasma for inactivation of viruses in water used in closed irrigation systems. We measured the plasma-mediated viral RNA degradation as well as the plasma-induced loss of viral infectivity using potato virus Y as a model virus due to its confirmed water transmissibility and economic as well as biological importance. We showed that only 1 min of plasma treatment is sufficient for successful inactivation of viruses in water samples with either high or low organic background. The plasma-mediated inactivation was efficient even at markedly higher virus concentrations than those expected in irrigation waters. Obtained results point to reactive oxygen species as the main mode of viral inactivation. Our laboratory-scale experiments confirm for the first time that plasma has an excellent potential as the eukaryotic virus inactivation tool for water sources and could thus provide a cost-effective solution for irrigation mediated plant virus transmission. The outstanding inactivation efficiency demonstrated by plasma treatments in water samples offers further expansions of its application to other water sources such as reused wastewater or contaminated drinking waters, as well as other plant, animal, and human waterborne viruses, ultimately leading to the prevention of water scarcity and numerous human, animal, and plant infections worldwide.
Keywords: cold atmospheric plasma, potato virus Y, virus inactivation, water decontamination
Published in DiRROS: 23.07.2024; Views: 123; Downloads: 94
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Abstract: Increasing research demonstrates the potential of donor-derived cell-free DNA (dd-cfDNA) as a biomarker for monitoring the health of various solid organ transplants. Several methods have been proposed for cfDNA analysis, including real-time PCR, digital PCR, and next generation sequencing-based approaches. We sought to revise the droplet digital PCR (ddPCR)-based approach to quantify relative dd-cfDNA in plasma from kidney transplant (KTx) patients using a novel pilot set of assays targeting single nucleotide polymorphisms that have a very high potential to distinguish cfDNA from two individuals. The assays are capable of accurate quantification of down to 0.1% minor allele content when analyzing 165 ng of human DNA. We found no significant differences in the yield of extracted cfDNA using the three different commercial kits tested. More cfDNA was extracted from the plasma of KTx patients than from healthy volunteers, especially early after transplantation. The median level of donor-derived minor alleles in KTx samples was 0.35%. We found that ddPCR using the evaluated assays within specific range is suitable for analysis of KTx patientsʼ plasma but recommend prior genotyping of donor DNA and performing reliable preamplification of cfDNA.
Keywords: kidney transplantation, droplet digital PCR, plasma cell-free DNA, minor allele quantification, assay evaluation, graft health monitoring
Published in DiRROS: 19.07.2024; Views: 130; Downloads: 66
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Abstract: Chemotherapy with platinum agent and etoposide for small-cell lung cancer (SCLC) is supposed to be associated with intermediate risk (10-20%) of febrileneutropenia. Primary prophylaxis with granulocyte colonystimulating factors (G-CSFs) is not routinely recommended by the treatment guidelines. However, in clinical practice febrile neutropenia is often observed with standard etoposide/platinum regimen. The aim of this analysis was to evaluate the frequency of neutropenia and febrile neutropenia in advanced SCLC patients in the first cycle of standard chemotherapy. Furthermore, we explored the association between severe neutropenia and etoposide peak plasma levels inthe same patients. The case series based analysis of 17 patients with advanced SCLC treated with standard platinum/etoposide chemotherapy, already included in the pharmacokinetics study with etoposide, was performed. Grade 3/4 neutropenia and febrile neutropenia, observed after the first cycle are reported. The neutrophil counts were determined on day one of the second cycle unless symptoms potentially related to neutropenia occurred. Adverse events were classified according to Common Toxicity Criteria 4.0. Additionally, association between severe neutropenia and etoposide peak plasma concentrations, which were measured in the scope of pharmacokinetic study, was explored. Two out of 17 patients received primary GCS-F prophylaxis. In 15 patient who did not receive primary prophylaxis the rates of both grade 3/4 neutropenia and febrile neutropenia were high (8/15 (53.3%) and 2/15 (13.3%), respectively), already in the first cycle of chemotherapy. One patient died due to febrile neutropenia related pneumonia. Neutropenic events are assumed to be related to increased etoposide plasma concentrations after a standard etoposide and cisplatin dose. While the mean etoposide peak plasma concentration in the first cycle of chemotherapy was 17.6 mg/l, the highest levels of 27.07 and 27.49 mg/l were determined in two patients with febrile neutropenia. Our study indicates that there is a need to reduce the risk of neutropenic events in chemotherapy treated advanced SCLC, starting in the first cycle. Mandatory use of primary G-CSF prophylaxis might be considered. Alternatively, use of improved risk models for identification of patients with increased risk for neutropenia and individualization of primary prophylaxis based on not only clinical characteristics but also on etoposide plasma concentration measurement, could be a new, promising options that deserves further evaluation.
Keywords: small cell lung cancer, platinum-etoposide chemotherapy, etoposide, febrile neutropenia, plasma drug concentration
Published in DiRROS: 22.04.2024; Views: 259; Downloads: 131
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Keywords: selective laser melting, 18Ni-300 maraging steel, heat treatment, plasma nitriding, retained and reverted austenite, wear and corrosion behaviour
Published in DiRROS: 25.03.2024; Views: 327; Downloads: 138
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Abstract: As a surface-hardening technique, plasma nitriding is a common procedure for improving the properties of conventional Ni-based alloys. The diffusion of nitrogen hardens a layer on the surface of the alloy, leading to better wear resistance and a higher coefficient of friction, as well as a higher surface hardness. This study reports the effect of plasma nitriding on additive-manufactured (AM) Inconel 625 (IN625) compared to its conventional manufactured and nitrided counterparts. The samples produced with the laser powder-bed fusion (LPBF) process were subsequently plasma nitrided in the as-built condition, stress-relief annealed at 870 °C and solution treated at 1050 °C. The plasma nitridings were carried out at 430 °C and 500 °C for 15 h. The growth kinetics of the nitride layer of the AM samples depends on the prior heat treatments and is faster in the as-built state due to the specific cellular structure. The lower nitriding temperature leads to the formation of expanded austenite in the nitride layer, while at the higher nitriding temperature, the expanded austenite decomposes and CrN precipitation occurs. The XRD and SEM analyses confirmed the presence of two layers: the surface layer and the diffusion layer beneath. The lower nitriding temperature caused the formation of expanded austenite or a combination of expanded austenite and CrN. The higher nitriding temperature led to the decomposition of the expanded austenite and to the formation/precipitation of CrN. The higher nitriding temperature also decreased the corrosion resistance slightly due to the increased number of precipitated Cr-nitrides. On the other hand, the wear resistance was significantly improved after plasma nitriding and was much less influenced by the nitriding temperature.
Keywords: additive manufacturing, powder-bed fusion, plasma nitriding, expanded austenite, wear and corrosion resistance, Ni-based alloy
Published in DiRROS: 31.01.2024; Views: 426; Downloads: 159
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