Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Funct Integr Genomics ; 23(2): 120, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-37036577

RESUMEN

MicroRNAs (miRNAs) regulate gene expression by RNA interference mechanism. In plants, miRNA genes (MIRs) which are grouped into conserved families, i.e. they are present among the different plant taxa, are involved in the regulation of many developmental and physiological processes. The roles of the nonconserved MIRs-which are MIRs restricted to one plant family, genus, or even species-are less recognized; however, many of them participate in the responses to biotic and abiotic stresses. Both over- and underproduction of miRNAs may influence various biological processes. Consequently, maintaining intracellular miRNA homeostasis seems to be crucial for the organism. Deletions and duplications in the genomic sequence may alter gene dosage and/or activity. We evaluated the extent of copy number variations (CNVs) among Arabidopsis thaliana (Arabidopsis) MIRs in over 1000 natural accessions, using population-based analysis of the short-read sequencing data. We showed that the conserved MIRs were unlikely to display CNVs and their deletions were extremely rare, whereas nonconserved MIRs presented moderate variation. Transposon-derived MIRs displayed exceptionally high diversity. Conversely, MIRs involved in the epigenetic control of transposons reactivated during development were mostly invariable. MIR overlap with the protein-coding genes also limited their variability. At the expression level, a higher rate of nonvariable, nonconserved miRNAs was detectable in Col-0 leaves, inflorescence, and siliques compared to nonconserved variable miRNAs, although the expression of both groups was much lower than that of the conserved MIRs. Our data indicate that CNV rate of Arabidopsis MIRs is related with their age, function, and genomic localization.


Asunto(s)
Arabidopsis , MicroARNs , Arabidopsis/genética , Arabidopsis/metabolismo , Variaciones en el Número de Copia de ADN , Genes de Plantas , MicroARNs/genética , MicroARNs/metabolismo , Genómica , ARN de Planta/genética , Regulación de la Expresión Génica de las Plantas , Secuencia Conservada
2.
Plant Cell ; 32(6): 1797-1819, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32265262

RESUMEN

Copy number variations (CNVs) greatly contribute to intraspecies genetic polymorphism and phenotypic diversity. Recent analyses of sequencing data for >1000 Arabidopsis (Arabidopsis thaliana) accessions focused on small variations and did not include CNVs. Here, we performed genome-wide analysis and identified large indels (50 to 499 bp) and CNVs (500 bp and larger) in these accessions. The CNVs fully overlap with 18.3% of protein-coding genes, with enrichment for evolutionarily young genes and genes involved in stress and defense. By combining analysis of both genes and transposable elements (TEs) affected by CNVs, we revealed that the variation statuses of genes and TEs are tightly linked and jointly contribute to the unequal distribution of these elements in the genome. We also determined the gene copy numbers in a set of 1060 accessions and experimentally validated the accuracy of our predictions by multiplex ligation-dependent probe amplification assays. We then successfully used the CNVs as markers to analyze population structure and migration patterns. Finally, we examined the impact of gene dosage variation triggered by a CNV spanning the SEC10 gene on SEC10 expression at both the transcript and protein levels. The catalog of CNVs, CNV-overlapping genes, and their genotypes in a top model dicot will stimulate the exploration of the genetic basis of phenotypic variation.


Asunto(s)
Arabidopsis/genética , Variaciones en el Número de Copia de ADN/genética , Genoma de Planta/genética , Elementos Transponibles de ADN/genética , Genotipo
3.
Stem Cells ; 38(4): 574-584, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31912945

RESUMEN

Pretransplant islet culture is associated with the loss of islet cell mass and insulin secretory function. Insulin secretion from islet ß-cells is primarily controlled by mitochondrial ATP generation in response to elevations in extracellular glucose. Coculture of islets with mesenchymal stromal cells (MSCs) improves islet insulin secretory function in vitro, which correlates with superior islet graft function in vivo. This study aimed to determine whether the improved islet function is associated with mitochondrial transfer from MSCs to cocultured islets. We have demonstrated mitochondrial transfer from human adipose MSCs to human islet ß-cells in coculture. Fluorescence imaging showed that mitochondrial transfer occurs, at least partially, through tunneling nanotube (TNT)-like structures. The extent of mitochondrial transfer to clinically relevant human islets was greater than that to experimental mouse islets. Human islets are subjected to more extreme cellular stressors than mouse islets, which may induce "danger signals" for MSCs, initiating the donation of MSC-derived mitochondria to human islet ß-cells. Our observations of increased MSC-mediated mitochondria transfer to hypoxia-exposed mouse islets are consistent with this and suggest that MSCs are most effective in supporting the secretory function of compromised ß-cells. Ensuring optimal MSC-derived mitochondria transfer in preculture and/or cotransplantation strategies could be used to maximize the therapeutic efficacy of MSCs, thus enabling the more widespread application of clinical islet transplantation.


Asunto(s)
Diabetes Mellitus Experimental/terapia , Células Secretoras de Insulina/metabolismo , Trasplante de Islotes Pancreáticos/métodos , Células Madre Mesenquimatosas/metabolismo , Mitocondrias/metabolismo , Animales , Células Cultivadas , Humanos , Ratones
4.
Neural Plast ; 2019: 9708905, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30936915

RESUMEN

Stroke is the second cause of death and more importantly first cause of disability in people over 40 years of age. Current therapeutic management of ischemic stroke does not provide fully satisfactory outcomes. Stroke management has significantly changed since the time when there were opened modern stroke units with early motor and speech rehabilitation in hospitals. In recent decades, researchers searched for biomarkers of ischemic stroke and neuroplasticity in order to determine effective diagnostics, prognostic assessment, and therapy. Complex background of events following ischemic episode hinders successful design of effective therapeutic strategies. So far, studies have proven that regeneration after stroke and recovery of lost functions may be assigned to neuronal plasticity understood as ability of brain to reorganize and rebuild as an effect of changed environmental conditions. As many neuronal processes influencing neuroplasticity depend on expression of particular genes and genetic diversity possibly influencing its effectiveness, knowledge on their mechanisms is necessary to understand this process. Epigenetic mechanisms occurring after stroke was briefly discussed in this paper including several mechanisms such as synaptic plasticity; neuro-, glio-, and angiogenesis processes; and growth of axon.


Asunto(s)
Encéfalo/fisiopatología , Plasticidad Neuronal/fisiología , Recuperación de la Función/fisiología , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Humanos
5.
Echocardiography ; 35(5): 735-742, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29790225

RESUMEN

In diagnosing cardiac and paracardiac masses, cardiac MRI (CMR) has gained acceptance as the gold standard. CMR has been observed to be superior to echocardiography in characterizing soft-tissue structures and, specifically, in classifying cardiac masses. The aim of our study was to evaluate the association between mortality and cardiac or paracardiac masses initially identified by echocardiography (ECHO) and confirmed by CMR. Between January 2002 and August 2007, a total of 158 patients underwent both ECHO and CMR for the evaluation of cardiac masses that were equivocal or undefined by ECHO. The primary study endpoints were 5-year all-cause mortality and 5-year cardiac mortality. Causes of death as of April 1, 2015 were obtained from medical records or the National Death Index. Patients were analyzed according to mass type determined by CMR using the Kruskal-Wallis test, Kaplan-Meier curves, and the log-rank test. Over a mean duration of follow-up of 10.4 ± 2.9 years (range: 0.01-12 years) post-CMR, the overall all-cause mortality rate was 25.9% (41/158). Median age at death was 76 years and there were 21 females (51.2%). Mortality rates in the different classifications of cardiac masses by CMR were as follows: 20% (1/5) in patients with a Nondiagnostic CMR; 20% (1/5) in Other Diagnoses; 17.9% (7/39) in No Masses (includes Normal Anatomical Variants); 16.7% (3/18) in Benign Masses; 23.8% (15/63) in Fat; 50% (5/10) in Thrombus; and 61.5% (8/13) in Malignant Mass. The mean survival time in patients with No Mass (n = 39) was not significantly longer than patients with any type of cardiac mass (n = 114) (P = .16). No significant difference was found in age at death between patients when grouped by CMR classification (P = .40). However, among CMR-confirmed masses, there were some significant differences by mass classification type (P = .006). During the follow-up period, 26% (41/158) of patients died and 22% (9/41) of the deaths were cardiovascular related; there was no significant difference in mean survival times with respect to cause of mortality (P = .23). In patients with cardiac masses, dually confirmed by ECHO and CMR, significant differences in survival time were observed based upon CMR classified type of mass while CMR was instrumental in obviating invasive biopsy.


Asunto(s)
Ecocardiografía/métodos , Predicción , Neoplasias Cardíacas/diagnóstico , Imagen por Resonancia Cinemagnética/métodos , Pericardio , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte/tendencias , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Neoplasias Cardíacas/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Pennsylvania/epidemiología , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Adulto Joven
6.
BMC Genomics ; 17(1): 893, 2016 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-27825302

RESUMEN

BACKGROUND: Intraspecies copy number variations (CNVs), defined as unbalanced structural variations of specific genomic loci, ≥1 kb in size, are present in the genomes of animals and plants. A growing number of examples indicate that CNVs may have functional significance and contribute to phenotypic diversity. In the model plant Arabidopsis thaliana at least several hundred protein-coding genes might display CNV; however, locus-specific genotyping studies in this plant have not been conducted. RESULTS: We analyzed the natural CNVs in the region overlapping MSH2 gene that encodes the DNA mismatch repair protein, and AT3G18530 and AT3G18535 genes that encode poorly characterized proteins. By applying multiplex ligation-dependent probe amplification and droplet digital PCR we genotyped those genes in 189 A. thaliana accessions. We found that AT3G18530 and AT3G18535 were duplicated (2-14 times) in 20 and deleted in 101 accessions. MSH2 was duplicated in 12 accessions (up to 12-14 copies) but never deleted. In all but one case, the MSH2 duplications were associated with those of AT3G18530 and AT3G18535. Considering the structure of the CNVs, we distinguished 5 genotypes for this region, determined their frequency and geographical distribution. We defined the CNV breakpoints in 35 accessions with AT3G18530 and AT3G18535 deletions and tandem duplications and showed that they were reciprocal events, resulting from non-allelic homologous recombination between 99 %-identical sequences flanking these genes. The widespread geographical distribution of the deletions supported by the SNP and linkage disequilibrium analyses of the genomic sequence confirmed the recurrent nature of this CNV. CONCLUSIONS: We characterized in detail for the first time the complex multiallelic CNV in Arabidopsis genome. The region encoding MSH2, AT3G18530 and AT3G18535 genes shows enormous variation of copy numbers among natural ecotypes, being a remarkable example of high Arabidopsis genome plasticity. We provided the molecular insight into the mechanism underlying the recurrent nature of AT3G18530-AT3G18535 duplications/deletions. We also performed the first direct comparison of the two leading experimental methods, suitable for assessing the DNA copy number status. Our comprehensive case study provides foundation information for further analyses of CNV evolution in Arabidopsis and other plants, and their possible use in plant breeding.


Asunto(s)
Arabidopsis/genética , Variaciones en el Número de Copia de ADN , Genes de Plantas , Genética de Población , Genoma de Planta , Genómica , Recombinación Homóloga , Proteínas de Arabidopsis/genética , Puntos de Rotura del Cromosoma , Genotipo , Proteína 2 Homóloga a MutS/genética , Filogeografía , Análisis de Secuencia de ADN
7.
ChemSusChem ; 17(6): e202301232, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-37975580

RESUMEN

Block copolymers utilizing oligomeric poly(pentylene-co-hexylene carbonate)diol modified with 2,4-diisocyanatotoluene and further with 2-bromo-N-(3-hydroxypropyl)-2-methylpropanamide were synthesized and utilized as Activators ReGenerated by Electron Transfer Atom Transfer Radical Polymerization macroinitiators to obtain a first generation of multifunctional recycling additives with poly(glycidyl methacrylate-co-butyl methacrylate-co-methyl methacrylate) side chains, which could act as chain extenders. Then, chosen additive was reacted with a radical scavenger, 3,5-ditertbutyl-4-hydroxybenzoic acid (DHBA), to obtain a second generation of reactive additives. Those copolymers had different numbers of epoxy groups per polymer chain, and different number of epoxides opened with DHBA, hence showed a range of properties, and were utilized as reactive modifiers for polylactide (PLA) extrusion melting. The first-generation modifiers caused an increase in PLA's blends relative melt viscosity, stabilized material properties, and enhanced impact strength, while the second-generation modifiers with more than 8 % of epoxide ring opened showed worse properties. However, they managed to suppress the UV degradation of PLA blend plates.

8.
Cancer Immunol Res ; 12(4): 427-439, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38315788

RESUMEN

Recent research indicates that gut microbiota may be vital in the advancement of melanoma. In this study, we found that melanoma patients exhibited a distinct gut mycobiota structure compared with healthy participants. Candida albicans, Candida dubliniensis, and Neurospora crassa were more abundant in samples from patients with melanoma, whereas Saccharomyces cerevisiae and Debaryomyces hansenii were less abundant. During anti-PD-1 treatment, the relative amount of Malassezia restricta and C. albicans increased. A higher level of Saccharomyces paradoxus was associated with a positive response to anti-PD-1 treatment, whereas a higher level of Tetrapisispora blattae was associated with a lack of clinical benefits. High levels of M. restricta and C. albicans, elevated serum lactate dehydrogenase, and being overweight were linked to increased risk of melanoma progression and poorer response to anti-PD-1 treatment. Thus, this study has revealed melanoma-associated mycobiome dysbiosis, characterized by altered fungal composition and fungi species associated with a higher risk of melanoma progression, identifying a role for the gut mycobiome in melanoma progression.


Asunto(s)
Microbioma Gastrointestinal , Melanoma , Micobioma , Humanos , Hongos/fisiología , Disbiosis/microbiología , Melanoma/tratamiento farmacológico , Saccharomyces cerevisiae
9.
Materials (Basel) ; 16(9)2023 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-37176317

RESUMEN

This article presents the influence of severe plastic deformation by hydrostatic extrusion (HE) on the thermal and structural properties of polyamide 6 (PA6). During the hydrostatic extrusion process, a fibrous structure oriented along the extrusion direction is formed, which was visualized during microscopic observations. The degree of crystallinity was analyzed by differential scanning calorimetry (DSC). Wide-angle X-ray scattering diffraction (WAXS) analysis was used to partially characterize the PA6 structure after the HE process. The contents of various forms of the crystalline phase in PA6 samples before and after the HE process were analyzed in fragments of spectroscopy in infrared (FTIR). The favorable properties of PA6 after the HE process were obtained after deformation under conditions generating an adiabatic temperature higher than the glass transition temperature and lower than the temperature of the onset of melting of the crystalline phase. Thermal analysis using DSC allowed us to conclude that in the PA6 after the HE process generating deformations in the range of 0.68-1.56, the proportion of the crystalline phase α increases in PA6. As the deformation increases in the HE process, the crystalline phase proportion increases by 12% compared to the initial material (before HE). The glass transition temperature of PA6 is ca. 50.6 °C, reduced for the sample after the HE process at a small deformation of 0.68 (PA6_0.68) to ca. 44.2 °C. For other samples, Tg is ca. 53.2-53.5 °C. As a result of the analysis of WAXS diffractograms of PA6 samples after various deformations in the HE process, the presence of typical peaks of phases α1 and α2 and γ was observed. The results of the FTIR spectroscopic analysis confirm these observations that as the deformation increases, the proportion of the crystalline phase α increases.

10.
Plant Methods ; 19(1): 129, 2023 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-37981669

RESUMEN

The evolution of plants to efficiently transport water and assimilates over long distances is a major evolutionary success that facilitated their growth and colonization of land. Vascular tissues, namely xylem and phloem, are characterized by high specialization, cell heterogeneity, and diverse cell components. During differentiation and maturation, these tissues undergo an irreversible sequence of events, leading to complete protoplast degradation in xylem or partial degradation in phloem, enabling their undisturbed conductive function. Due to the unique nature of vascular tissue, and the poorly understood processes involved in xylem and phloem development, studying the molecular basis of tissue differentiation is challenging. In this review, we focus on methods crucial for gene expression research in conductive tissues, emphasizing the importance of initial anatomical analysis and appropriate material selection. We trace the expansion of molecular techniques in vascular gene expression studies and discuss the application of single-cell RNA sequencing, a high-throughput technique that has revolutionized transcriptomic analysis. We explore how single-cell RNA sequencing will enhance our knowledge of gene expression in conductive tissues.

11.
mSystems ; 8(2): e0098622, 2023 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-36786595

RESUMEN

Recent studies revealed a significant role of the gut fungal community in human health. Here, we investigated the content and variation of gut mycobiota among subjects from the European population. We explored the interplay between gut fungi and various host-related sociodemographic, lifestyle, health, and dietary factors. The study included 923 participants. Fecal DNA samples were analyzed by whole-metagenome high-throughput sequencing. Subsequently, fungi taxonomic profiles were determined and accompanied by computational and statistical analyses of the association with 53 host-related factors. Fungal communities were characterized by a high prevalence of Saccharomyces, Candida, and Sporisorium. Ten factors were found to correlate significantly with the overall mycobiota variation. Most were diet related, including the consumption of chips, meat, sodas, sweetening, processed food, and alcohol, followed by age and marital status. Differences in α- and/or ß-diversity were also reported for other factors such as body mass index (BMI), job type, autoimmunological diseases, and probiotics. Differential abundance analysis revealed fungal species that exhibited different patterns of changes under specific conditions. The human gut mycobiota is dominated by yeast, including Saccharomyces, Malassezia, and Candida. Although intervolunteer variability was high, several fungal species persisted across most samples, which may be evidence that a core gut mycobiota exists. Moreover, we showed that host-related factors such as diet, age, and marital status influence the variability of gut mycobiota. To our knowledge, this is the first large and comprehensive study of the European cohort in terms of gut mycobiota associations with such an extensive and differentiated host-related set of factors. IMPORTANCE The human gut is inhabited by many organisms, including bacteria and fungi, that may affect human health. However, research on human gut mycobiome is still rare. Moreover, the large European-based cohort study is missing. Here, we analyzed the first large European cohort in terms of gut mycobiota associations with a differentiated host-related set of factors. Our results showed that chips, meat, sodas, sweetening, processed food, beer, alcohol consumption, age, and marital status were associated with the variability of gut mycobiota. Moreover, our analysis revealed changes in abundances at the fungal species level for many investigated factors. Our results can suggest potentially valuable paths for further, narrowly focused research on gut mycobiome and its impact on human health. In the coming era of gut microbiome-based precision medicine, further research into the relationship between different mycobial structures and host-related factors may result in new preventive approaches or therapeutic procedures.


Asunto(s)
Microbioma Gastrointestinal , Micobioma , Saccharomyces , Humanos , Estudios de Cohortes , Hongos/genética , Microbioma Gastrointestinal/genética , Heces/microbiología , Candida , Saccharomyces cerevisiae
12.
J AOAC Int ; 95(5): 1378-85, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23175969

RESUMEN

The decomposition of the widely used organophosphorus pesticide parathion was carried out in aqueous solutions by the use of gamma-irradiation from a 60Co source or ozonation by means of an ozone generator, and by combined processes of ozonation and radiolysis. Factors affecting the parathion decomposition as well formation and decomposition of the main by-products, including irradiation dose, length of ozonation time, and presence of common scavengers, were investigated. The most efficient was found to be the gamma-irradiation process combined with a short ozonation period; about 1 kGy irradiation dose was sufficient to decompose the pesticide in 15 mg/L solutions. Chemical studies of the decomposition of parathion were accompanied by monitoring of toxicity changes of irradiated solutions with the Microtox test.


Asunto(s)
Rayos gamma , Insecticidas/química , Ozono/química , Paratión/química , Técnicas de Química Analítica
13.
Materials (Basel) ; 15(1)2022 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-35009460

RESUMEN

Lactic acid oligomers (OLAs) were in situ synthesized from lactic acid (LAc) and grafted onto chokeberry pomace (CP) particleboards by direct condensation. Biocomposites of poly (lactic acid) (PLA) and modified/unmodified CP particles containing different size fractions were obtained using a mini-extruder. To confirm the results of the grafting process, the FTIR spectra of filler particles were obtained. Performing 1HNMR spectroscopy allowed us to determine the chemical structure of synthesized OLAs. The thermal degradation of modified CP and biocomposites were studied using TGA, and the thermal characteristics of biocomposites were investigated using DSC. In order to analyse the adhesion between filler particles and PLA in biocomposites, SEM images of brittle fracture surfaces were registered. The mechanical properties of biocomposites were studied using a tensile testing machine. FTIR and 1HNMR analysis confirmed the successful grafting process of OLAs. The modified filler particles exhibited a better connection with hydrophobic PLA matrix alongside improved mechanical properties than the biocomposites with unmodified filler particles. Moreover, a DSC analysis of the biocomposites with modified CP showed a reduction in glass temperature on average by 9 °C compared to neat PLA. It confirms the plasticizing effect of grafted and ungrafted OLAs. The results are promising, and can contribute to increasing the use of agri-food lignocellulosic residue in manufacturing biodegradable packaging.

14.
iScience ; 25(10): 105142, 2022 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-36193047

RESUMEN

Recent advances in imaging flow cytometry (IFC) have revolutionized high-throughput multiparameter analyses at single-cell resolution. Although enabling the discovery of population heterogeneities and the detection of rare events, IFC generates hyperdimensional datasets that demand innovative analytical approaches. Current methods work in a supervised manner, utilize only limited information content, or require large annotated reference datasets. Dimensionality reduction algorithms, including uniform manifold approximation and projection (UMAP), have been successfully applied to analyze the large number of parameters generated in various high-throughput techniques. Here, we apply a workflow incorporating UMAP to analyze different IFC datasets. We demonstrate that it out-competes other popular dimensionality reduction methods in speed and accuracy. Moreover, it enables fast visualization, clustering, and tagging of unannotated objects in large-scale experiments. We anticipate that our workflow will be a robust method to address complex IFC datasets, either alone or as an upstream addition to the deep learning approaches.

15.
Chemosphere ; 295: 133920, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35143857

RESUMEN

The mechanism of high-energy radiation induced degradation of perfluorooctanoate anion (PFOA, C7F15COO-) was investigated in aqueous solutions. Identification and quantification of transient species was performed by pulse radiolysis and of final products by gas and ion chromatography, electrochemical method using fluoride ion-selective electrode and ESI-MS after γ-radiolysis. Experimental data were further supported by kinetic simulations and quantum mechanical calculations. Radiation induced degradation of PFOA includes as a primary step one-electron reduction of PFOA by hydrated electrons (e-aq) resulting in formation of [C7F15COO-]●-. The rate constants of this reaction were found to be in the range 7.7 × 107-1.3 × 108 M-1s-1 for ionic strength of the solutions in the range 0.01-0.1 M and were independent of pH of the solutions. At pH > 11 [C7F15COO-]●- tends to defluorination whereas at lower pH undergoes protonation forming [C7F15COOH]•-. A sequence of consecutive reactions involving [C7F15COOH]•- leads to PFOA regeneration what explains a high radiation resistance of PFOA at moderately acidic solutions. A simultaneous presence of oxidizing transient species (●OH) in the irradiated system enhanced decomposition of (C7F14)·COO- as well as [C7F15COOH]•-. The key steps in this complex radical mechanism are the reactions of both these radical anions with ●OH leading to semi-stable products which further undergo consecutive thermal reactions. On the other hand, direct reactions of PFOA with ●OH and ●H were found to be relatively slow (7 × 103 and <4 × 107 M-1s-1, respectively) and do not play relevant role in PFOA degradation. Collected for the first time results, such as dependence of selected reaction rate constants and selected products radiation chemical yields on pH as well as finding of several semi-stable products, missing in previous studies, indicate incompleteness of published earlier reaction pathways of PFOA degradation. The presented overall mechanism explains experimental results and verifies previously suggested mechanisms found in the literature.


Asunto(s)
Caprilatos , Estrés Oxidativo , Aniones , Caprilatos/química , Fluorocarburos , Cinética , Oxidación-Reducción
16.
Sci Rep ; 12(1): 8470, 2022 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-35589762

RESUMEN

In recent years, the number of metagenomic studies increased significantly. Wide range of factors, including the tremendous community complexity and variability, is contributing to the challenge in reliable microbiome community profiling. Many approaches have been proposed to overcome these problems making hardly possible to compare results of different studies. The significant differences between procedures used in metagenomic research are reflected in a variation of the obtained results. This calls for the need for standardisation of the procedure, to reduce the confounding factors originating from DNA isolation, sequencing and bioinformatics analyses in order to ensure that the differences in microbiome composition are of a true biological origin. Although the best practices for metagenomics studies have been the topic of several publications and the main aim of the International Human Microbiome Standard (IHMS) project, standardisation of the procedure for generating and analysing metagenomic data is still far from being achieved. To highlight the difficulties in the standardisation of metagenomics methods, we thoroughly examined each step of the analysis of the human gut microbiome. We tested the DNA isolation procedure, preparation of NGS libraries for next-generation sequencing, and bioinformatics analysis, aimed at identifying microbial taxa. We showed that the homogenisation time is the leading factor impacting sample diversity, with the recommendation for a shorter homogenisation time (10 min). Ten minutes of homogenisation allows for better reflection of the bacteria gram-positive/gram-negative ratio, and the obtained results are the least heterogenous in terms of beta-diversity of samples microbial composition. Besides increasing the homogenisation time, we observed further potential impact of the library preparation kit on the gut microbiome profiling. Moreover, our analysis revealed that the choice of the library preparation kit influences the reproducibility of the results, which is an important factor that has to be taken into account in every experiment. In this study, a tagmentation-based kit allowed for obtaining the most reproducible results. We also considered the choice of the computational tool for determining the composition of intestinal microbiota, with Kraken2/Bracken pipeline outperforming MetaPhlAn2 in our in silico experiments. The design of an experiment and a detailed establishment of an experimental protocol may have a serious impact on determining the taxonomic profile of the intestinal microbiome community. Results of our experiment can be helpful for a wide range of studies that aim to better understand the role of the gut microbiome, as well as for clinical purposes.


Asunto(s)
Metagenómica , Microbiota , ADN , Humanos , Metagenoma , Metagenómica/métodos , Microbiota/genética , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados
17.
Cancers (Basel) ; 14(4)2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35205741

RESUMEN

Identification of biomarkers that could be used for the prediction of the response to neoadjuvant radiotherapy (neo-RT) in locally advanced rectal cancer remains a challenge addressed by different experimental approaches. Exosomes and other classes of extracellular vesicles circulating in patients' blood represent a novel type of liquid biopsy and a source of cancer biomarkers. Here, we used a combined proteomic and metabolomic approach based on mass spectrometry techniques for studying the molecular components of exosomes isolated from the serum of rectal cancer patients with different responses to neo-RT. This allowed revealing several proteins and metabolites associated with common pathways relevant for the response of rectal cancer patients to neo-RT, including immune system response, complement activation cascade, platelet functions, metabolism of lipids, metabolism of glucose, and cancer-related signaling pathways. Moreover, the composition of serum-derived exosomes and a whole serum was analyzed in parallel to compare the biomarker potential of both specimens. Among proteins that the most properly discriminated good and poor responders were GPLD1 (AUC = 0.85, accuracy of 74%) identified in plasma as well as C8G (AUC = 0.91, accuracy 81%), SERPINF2 (AUC = 0.91, accuracy 79%) and CFHR3 (AUC = 0.90, accuracy 81%) identified in exosomes. We found that the proteome component of serum-derived exosomes has the highest capacity to discriminate samples of patients with different responses to neo-RT when compared to the whole plasma proteome and metabolome. We concluded that the molecular components of exosomes are associated with the response of rectal cancer patients to neo-RT and could be used for the prediction of such response.

18.
Materials (Basel) ; 14(13)2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34206533

RESUMEN

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections-parallel and perpendicular to the direction of the foam growth-while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.

19.
Polymers (Basel) ; 12(12)2020 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-33317209

RESUMEN

Semi-rigid composites of polyurethane foams (SRPUF) modified with the addition of keratin flour from poultry feathers and flame retardant additives were manufactured. Ten percent by mass of keratin fibers was added to the foams as well as halogen-free flame retardant additives such as Fyrol PNX, expandable graphite, metal oxides, in amounts such that their total mass did not exceed 15%. Thermal and mechanical properties were tested. Water absorption, dimensional stability, apparent density and flammability of produced foams were determined. It was found that the use of keratin fibers and flame retardant additives changes the foam synthesis process, changes their structure and properties as well as their combustion process. The addition of the filler made of keratin fibers significantly limits the amount of smoke generated during foam burning. The most favorable reduction of heat and smoke release rate was observed for foams with the addition of 10% keratin fibers and 10% expandable graphite. Systems of reducing combustibility of polyurethane foams using keratin fillers are a new solution on a global scale.

20.
Front Pharmacol ; 11: 1123, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32922285

RESUMEN

BACKGROUND: In Poland drug programmes developed by the Minister of Health and financed by the National Health Fund are special reimbursement frameworks of innovative, expensive, and mostly hospital based medical products used for a small number of patients. RESEARCH DESIGN: The research presented in this paper is based on data analysis published by the National Health Fund in Poland. The analysis focused on estimating public payer expenditure on drugs available within drug programmes from 2015 to 2018. RESULTS: In subsequent years, reimbursement of drugs used within drug programmes was associated with the National Health Fund budget expenditure of 635 mln USD, 755 mln USD, 854 mln USD, and 921 mln USD, respectively. Reimbursement of oncology drug programmes constituted 48.1%, 42.5%, 47.1%, and 52.4% and were approximately 305, 312, 402, 483 mln USD, whereas values of non-oncology drug programmes were approximately 330, 434, 452, and 438 mln USD which constituted 51.9%, 57.5%, 52.9%, and 47.6% respectively. CONCLUSION: Despite the fact that the expenditure on drug programs in Poland are increasing every year, they undoubtedly improve the patient's access to the most innovative oncological and nononcological therapies in the Polish healthcare system.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA