Transcriptomic profiling reveals histone acetylation-regulated genes involved in somatic embryogenesis in Arabidopsis thaliana.

BACKGROUND: Somatic embryogenesis (SE) exemplifies the unique developmental plasticity of plant cells. The regulatory processes, including epigenetic modifications controlling embryogenic reprogramming of cell transcriptome, have just started to be revealed. RESULTS: To identify the genes of histone acetylation-regulated expression in SE, we analyzed global transcriptomes of Arabidopsis explants undergoing embryogenic induction in response to treatment with histone deacetylase inhibitor, trichostatin A (TSA). The TSA-induced and auxin (2,4-dichlorophenoxyacetic acid; 2,4-D)-induced transcriptomes were compared. RNA-seq results revealed the similarities of the TSA- and auxin-induced transcriptomic responses that involve extensive deregulation, mostly repression, of the majority of genes. Within the differentially expressed genes (DEGs), we identified the master regulators (transcription factors - TFs) of SE, genes involved in biosynthesis, signaling, and polar transport of auxin and NITRILASE-encoding genes of the function in indole-3-acetic acid (IAA) biosynthesis. TSA-upregulated TF genes of essential functions in auxin-induced SE, included LEC1/LEC2, FUS3, AGL15, MYB118, PHB, PHV, PLTs, and WUS/WOXs. The TSA-induced transcriptome revealed also extensive upregulation of stress-related genes, including those related to stress hormone biosynthesis. In line with transcriptomic data, TSA-induced explants accumulated salicylic acid (SA) and abscisic acid (ABA), suggesting the role of histone acetylation (Hac) in regulating stress hormone-related responses during SE induction. Since mostly the adaxial side of cotyledon explant contributes to SE induction, we also identified organ polarity-related genes responding to TSA treatment, including AIL7/PLT7, RGE1, LBD18, 40, HB32, CBF1, and ULT2. Analysis of the relevant mutants supported the role of polarity-related genes in SE induction. CONCLUSION: The study results provide a step forward in deciphering the epigenetic network controlling embryogenic transition in somatic cells of plants.

An intramolecular disulphide bond in human 4E-T affects its binding to eIF4E1a protein.

The cap at the 5'terminus of mRNA is a key determinant of gene expression in eukaryotic cells, which among others is required for cap dependent translation and protects mRNA from degradation. These properties of cap are mediated by several proteins. One of them is 4E-Transporter (4E-T), which plays an important role in translational repression, mRNA decay and P-bodies formation. 4E-T is also one of several proteins that interact with eukaryotic initiation factor 4E (eIF4E), a cap binding protein which is a key component of the translation initiation machinery. The molecular mechanisms underlying the interactions of these two proteins are crucial for mRNA processing. Studying the interactions between human eIF4E1a and the N-terminal fragment of 4E-T that possesses unstructured 4E-binding motifs under non-reducing conditions, we observed that 4E-T preferentially forms an intramolecular disulphide bond. This "disulphide loop" reduces affinity of 4E-T for eIF4E1a by about 300-fold. Considering that only human 4E-T possesses two cysteines located between the 4E binding motifs, we proposed that the disulphide bond may act as a switch to regulate interactions between the two proteins.

Selected Biochemical Blood Parameters and a Risk of Pressure Ulcers in Patients Receiving Treatment in Intensive Care Units.

Background and Objectives: This study aimed to assess the level of selected biochemical parameters in venous blood and their potential effects on the development of pressure ulcers in patients treated in intensive care settings. Materials and Methods: Fifty patients hospitalised in an intensive care unit (ICU) were enrolled for the study. The methods used included controlled observation, literature review and medical record analysis. The observation protocol applied in the study consisted of two parts comprising the basic information, sociodemographic data, results of laboratory tests (CRP, PCT, albumin, protein and haemoglobin concentrations) as well as the Braden Scale for Predicting Pressure Ulcer Risk. Results: The subjects presented moderate to high risk of pressure ulcers, reflected by the mean score of 8.18 ± 1.3 points, with minimum and maximum scores of 6 and 12 points, respectively. Normal albumin level was identified in only five subjects (10.0%) while 45 subjects (90.0%) were found with results below the norm. A statistical relationship was observed between such variables as albumin concentration (p < 0.01) and total protein level (p = 0.007). The findings show a strong correlation between the score in the Braden Scale and the level of albumins (R = 0.55). Conclusions: In our study, lower concentrations of albumins and total proteins correspond to a greater risk of pressure ulcers.

SERS activity and spectroscopic properties of Zn and ZnO nanostructures obtained by electrochemical and green chemistry methods for applications in biology and medicine.

This work for the first time evaluates the ability of homogeneous, stable, and pure zinc oxide nanoparticles (ZnONPs-GS) synthesized by "green chemistry" - an environmentally friendly, cheap, and easy method that allows efficient use of plant waste, such as banana peels, for the selective detection of four neurotransmitters present in body fluids and promotion of the SERS effect. Selective adsorption on ZnONPs-GS was compared with adsorption on the surface of (1) ZnONPs, which were obtained by electrochemical dissolution of zinc in a solution free of surfactants and (2) mechanically polished surface of bare Zn. The study showed that SERS spectroscopy using unique marker bands allows distinguishing whether the adsorbate is deposited on the surface of zinc or zinc oxide. Thus, the combination of the SERS technique with an optical probe can allow an in vivo determination of the condition of galvanized implants. The use of SERS has been extended to monitor the photocatalytic properties of surface-functionalized ZnO nanoparticles. It has been shown that despite the same structure, purity, and adsorption properties, ZnONPs-GS obtained using "green chemistry" are more bio-friendly for biological material than those obtained by the electrochemical method. This is because the surface of ZnONPs-GS is free of hydroxyl groups, which can easily form reactive oxygen species when the surface is exposed to visible radiation. Thus, surface-functionalized ZnONPS-GS can protect the biological material from the damage caused by the production and attack of an excess of ROS. Also, for an exemplary neurotransmitter, structural changes when it is not-covalently bound to Zn/ZnO were compared with the structural changes of this neurotransmitter deposited on the surface of various metals (Cu, α-Ti, and α-Fe) and metal oxides (leaf-like CuO, rutile-TiO2, and γ-Fe2O3). It has been shown that adsorption only slightly depends on the type of metallic surface and the development of this surface for roughness up to 1 micron. Metal substrates were characterized before and after the neurotransmitters' adsorption. UV-Vis, Raman, and ATR-FTIR confirmed the formation of ZnO nanoparticles. XRD showed a high crystalline structure of wurtzite. TEM and DLS showed that nanoparticles are spherical, well dispersed, and have a uniform size.

Research Tools for the Functional Genomics of Plant miRNAs During Zygotic and Somatic Embryogenesis.

During early plant embryogenesis, some of the most fundamental decisions on fate and identity are taken making it a fascinating process to study. It is no surprise that higher plant embryogenesis was intensively analysed during the last century, while somatic embryogenesis is probably the most studied regeneration model. Encoded by the MIRNA, short, single-stranded, non-coding miRNAs, are commonly present in all Eukaryotic genomes and are involved in the regulation of the gene expression during the essential developmental processes such as plant morphogenesis, hormone signaling, and developmental phase transition. During the last few years dedicated to miRNAs, analytical methods and tools have been developed, which have afforded new opportunities in functional analyses of plant miRNAs, including (i) databases for in silico analysis; (ii) miRNAs detection and expression approaches; (iii) reporter and sensor lines for a spatio-temporal analysis of the miRNA-target interactions; (iv) in situ hybridisation protocols; (v) artificial miRNAs; (vi) MIM and STTM lines to inhibit miRNA activity, and (vii) the target genes resistant to miRNA. Here, we attempted to summarise the toolbox for functional analysis of miRNAs during plant embryogenesis. In addition to characterising the described tools/methods, examples of the applications have been presented.

Current Perspectives on the Auxin-Mediated Genetic Network that Controls the Induction of Somatic Embryogenesis in Plants.

Auxin contributes to almost every aspect of plant development and metabolism as well as the transport and signalling of auxin-shaped plant growth and morphogenesis in response to endo- and exogenous signals including stress conditions. Consistently with the common belief that auxin is a central trigger of developmental changes in plants, the auxin treatment of explants was reported to be an indispensable inducer of somatic embryogenesis (SE) in a large number of plant species. Treating in vitro-cultured tissue with auxins (primarily 2,4-dichlorophenoxyacetic acid, which is a synthetic auxin-like plant growth regulator) results in the extensive reprogramming of the somatic cell transcriptome, which involves the modulation of numerous SE-associated transcription factor genes (TFs). A number of SE-modulated TFs that control auxin metabolism and signalling have been identified, and conversely, the regulators of the auxin-signalling pathway seem to control the SE-involved TFs. In turn, the different expression of the genes encoding the core components of the auxin-signalling pathway, the AUXIN/INDOLE-3-ACETIC ACIDs (Aux/IAAs) and AUXIN RESPONSE FACTORs (ARFs), was demonstrated to accompany SE induction. Thus, the extensive crosstalk between the hormones, in particular, auxin and the TFs, was revealed to play a central role in the SE-regulatory network. Accordingly, LEAFY COTYLEDON (LEC1 and LEC2), BABY BOOM (BBM), AGAMOUS-LIKE15 (AGL15) and WUSCHEL (WUS) were found to constitute the central part of the complex regulatory network that directs the somatic plant cell towards embryogenic development in response to auxin. The revealing picture shows a high degree of complexity of the regulatory relationships between the TFs of the SE-regulatory network, which involve direct and indirect interactions and regulatory feedback loops. This review examines the recent advances in studies on the auxin-controlled genetic network, which is involved in the mechanism of SE induction and focuses on the complex regulatory relationships between the down- and up-stream targets of the SE-regulatory TFs. In particular, the outcomes from investigations on Arabidopsis, which became a model plant in research on genetic control of SE, are presented.

AGL15 Controls the Embryogenic Reprogramming of Somatic Cells in Arabidopsis through the Histone Acetylation-Mediated Repression of the miRNA Biogenesis Genes.

The embryogenic transition of somatic cells requires an extensive reprogramming of the cell transcriptome. Relevantly, the extensive modulation of the genes that have a regulatory function, in particular the genes encoding the transcription factors (TFs) and miRNAs, have been indicated as controlling somatic embryogenesis (SE) that is induced in vitro in the somatic cells of plants. Identifying the regulatory relationships between the TFs and miRNAs during SE induction is of central importance for understanding the complex regulatory interplay that fine-tunes a cell transcriptome during the embryogenic transition. Hence, here, we analysed the regulatory relationships between AGL15 (AGAMOUS-LIKE 15) TF and miR156 in an embryogenic culture of Arabidopsis. Both AGL15 and miR156 control SE induction and AGL15 has been reported to target the MIR156 genes in planta. The results showed that AGL15 contributes to the regulation of miR156 in an embryogenic culture at two levels that involve the activation of the MIR156 transcription and the containment of the abundance of mature miR156 by repressing the miRNA biogenesis genes DCL1 (DICER-LIKE1), SERRATE and HEN1 (HUA-ENHANCER1). To repress the miRNA biogenesis genes AGL15 seems to co-operate with the TOPLESS co-repressors (TPL and TPR1-4), which are components of the SIN3/HDAC silencing complex. The impact of TSA (trichostatin A), an inhibitor of the HDAC histone deacetylases, on the expression of the miRNA biogenesis genes together with the ChIP results implies that histone deacetylation is involved in the AGL15-mediated repression of miRNA processing. The results indicate that HDAC6 and HDAC19 histone deacetylases might co-operate with AGL15 in silencing the complex that controls the abundance of miR156 during embryogenic induction. This study provides new evidence about the histone acetylation-mediated control of the miRNA pathways during the embryogenic reprogramming of plant somatic cells and the essential role of AGL15 in this regulatory mechanism.

Epigenetic Regulation of Auxin-Induced Somatic Embryogenesis in Plants.

Somatic embryogenesis (SE) that is induced in plant explants in response to auxin treatment is closely associated with an extensive genetic reprogramming of the cell transcriptome. The significant modulation of the gene transcription profiles during SE induction results from the epigenetic factors that fine-tune the gene expression towards embryogenic development. Among these factors, microRNA molecules (miRNAs) contribute to the post-transcriptional regulation of gene expression. In the past few years, several miRNAs that regulate the SE-involved transcription factors (TFs) have been identified, and most of them were involved in the auxin-related processes, including auxin metabolism and signaling. In addition to miRNAs, chemical modifications of DNA and chromatin, in particular the methylation of DNA and histones and histone acetylation, have been shown to shape the SE transcriptomes. In response to auxin, these epigenetic modifications regulate the chromatin structure, and hence essentially contribute to the control of gene expression during SE induction. In this paper, we describe the current state of knowledge with regard to the SE epigenome. The complex interactions within and between the epigenetic factors, the key SE TFs that have been revealed, and the relationships between the SE epigenome and auxin-related processes such as auxin perception, metabolism, and signaling are highlighted.

miR393 contributes to the embryogenic transition induced in vitro in Arabidopsis via the modification of the tissue sensitivity to auxin treatment.

MAIN CONCLUSION: miR393 was found to control embryogenic transition in somatic cells in Arabidopsis via control of the TIR1 and AFB2 auxin receptors genes of the F-box family. miR393 molecules are believed to regulate the expression of the auxin receptors of the TAAR clade. Considering the central role of auxin in the induction of somatic embryogenesis (SE) in plant explants cultured in vitro, the involvement of miR393 in the embryogenic transition of somatic cells has been hypothesised. To verify this assumption, the reporter, overexpressor and mutant lines in genes encoded MIR393 and TIR1/AFB proteins of the F-box family were analysed during SE in Arabidopsis. Expression profiling of MIR393a and MIR393b, mature miR393 and the target genes (TIR1, AFB1, AFB2, AFB3) were investigated in explants undergoing SE. In addition, the embryogenic potential of various genotypes with a modified activity of the MIR393 and TIR1/AFB targets was evaluated. The distinct increase in the accumulation of miR393 that was coupled with a notable down-regulation of TIR1 and AFB2 targets was observed at the early phase of SE induction. Relevant to this observation, the GUS/GFP monitored expression of MIR393, TIR1 and AFB2 transcripts was localised in explant tissue undergoing SE induction. The results suggest the miR393-mediated regulation of TIR1 and AFB2 during embryogenic transition induced in Arabidopsis and a modification of the explant sensitivity to auxin treatment is proposed as underlying this regulatory pathway.

Mechanism of O2 Activation by α-Ketoglutarate Dependent Oxygenases Revisited. A Quantum Chemical Study.

Four mechanisms previously proposed for dioxygen activation catalyzed by α-keto acid dependent oxygenases (α-KAO) were studied with dispersion-corrected DFT methods employing B3LYP and TPSSh functionals in combination with triple-ζ basis set (cc-pVTZ). The aim of this study was to revisit mechanisms suggested in the past decade and resolve remaining issues related to dioxygen activation. Mechanism A, which runs on the quintet potential energy surface (PES) and includes formation of an Fe(III)-superoxide radical anion complex, subsequent oxidative decarboxylation, and O-O bond cleavage, was found to be most likely. However, mechanism B taking place on the septet PES involves a rate limiting barrier comparable to the one found for mechanism A, and thus it cannot be excluded, though two other mechanisms (C and D) were ruled out. Mechanism C is a minor variation of mechanism A, whereas mechanism D proceeds through formation of a triplet Fe(IV)-alkyl peroxo bridged intermediate. The study covered also full optimization of relevant minimum energy crossing points (MECPs). The relative energy of critical intermediates was also studied with the CCSD(T) method in order to benchmark TPSSh and B3LYP functionals with respect to their credibility in predicting relative energies of septet and triplet spin states of the ternary enzyme-Fe-α-keto glutarate (α-KG)-O2 complex.

[Autoimmune polyglandular syndromes - literature review and analysis of clinical course in chosen cases]. / Zespoly autoimmunologicznych zaburzen wielogruczolowych - przeglad pismiennictwa oraz analiza przebiegu choroby u wybranych przypadków.

Autoimmune polyglandular syndromes (APS) are the conditions characterized by coexistence of at least two organ-specific endocrine autoimmune disorders. The syndromes often coexist with connective tissue diseases with the presence non-organ specific antibodies. The aim of the study was to present two clinical cases of polymyositis and dermatomyositis in the course of APS type 3d. Case 1, a 24-year-old woman, with diabetes mellitus type 1 was diagnosed at the age of 17 years and polymyositis recognized at the age of 24 years based on clinical manifestations and additional tests (proximal muscle weakness, typical electromyographic changes, typical histopathological changes in skin and muscles biopsy, elevated muscle enzymes) accompanied by interstitial lung disorder. Moreover, Hashimoto`s autoimmune thyroiditis was diagnosed. Case 2, a 47-year-old man, with a several-year history of diabetes mellitus type 1, diagnosed with dermatomyositis and autoimmune thyroiditis. The immunosuppressive therapy was instituted in both cases, which reduced the symptoms of connective tissue disease. To sum up, about 25-30% of patients are affected by extraglandular autoimmune diseases, including connective tissue diseases, in the course of APS. An interdisciplinary approach is required in this group of conditions due to a multitude of disorders as well as diagnostic and therapeutic difficulties.

[Cardiac abnormalities in patients with myotonic dystrophy--preliminary results]. / Zaburzenia kardiologiczne u pacjentów z dystrofia miotoniczna--doniesienie wstepne.

INTRODUCTION: Myotonic dystrophy (DM) is an inherited multisystem disorder associated with myotonia, progressive skeletal muscle weakness and atrophy, involvement of peripheral and central nervous system and sudden death likely due to atrioventricular block and/or ventricular arrhythmia. AIM OF THE STUDY: to assess the type and degree of cardiac and neurological involvement in patients (pts) with DM. MATERIALS AND METHODS: 10 pts (6 male), in mean age of 35 +/- 13 years, treated for DM type I (DM1)--7 pts and type II (DM2)--3 pts. All pts underwent a neurological examination including muscle strength assessment as well as cardiac diagnostics including: standard and 48-hour ambulatory electrocardiogram, echocardiographic examination, magnetic resonance imaging (MRI) of the heart and late potentials assessment. RESULTS: Muscle strength was moderately diminished (46-48 points in MRC sub score) in 3 pts with DM1 and mildly diminished (56-58 points in MRC sub score) in 2 pts with DM2. These patients showed clinical symptoms of myopathy. Cardiovascular examinations revealed: QRS duration above 110 ms in 5 pts, clinically significant supraventricular arrhythmia or atrioventricular block in 3 pts, focal myocardial fibrosis in 3 pts, asymmetric hypertrophy of inter-ventricular septum in 1 patient, presence of late potentials in 5 pts. We have not observed correlation between impaired muscle strength and cardiac abnormalities. However, most pronounced cardiac abnormalities were observed in 2 male DM1 patients with clinical symptoms of myopathy and lowest MRC score. At a mean follow up of 3.2 +/- 1.4 years none of the pts died. CONCLUSIONS: Cardiac involvement in pts with myotonic dystrophy is frequent and is characterized by phenotypic heterogeneity. Detection of cardiac abnormalities may require extensive diagnostics. The most important is the assessment of ECG. Cardiac and neurological abnormalities vary in intensity between patients without close relationship to each other.

Role of substrate positioning in the catalytic reaction of 4-hydroxyphenylpyruvate dioxygenase-A QM/MM Study.

Ring hydroxylation and coupled rearrangement reactions catalyzed by 4-hydroxyphenylpyruvate dioxygenase were studied with the QM/MM method ONIOM(B3LYP:AMBER). For electrophilic attack of the ferryl species on the aromatic ring, five channels were considered: attacks on the three ring atoms closest to the oxo ligand (C1, C2, C6) and insertion of oxygen across two bonds formed by them (C1-C2, C1-C6). For the subsequent migration of the carboxymethyl substituent, two possible directions were tested (C1→C2, C1→C6), and two different mechanisms were sought (stepwise radical, single-step heterolytic). In addition, formation of an epoxide (side)product and benzylic hydroxylation, as catalyzed by the closely related hydroxymandelate synthase, were investigated. From the computed reaction free energy profiles it follows that the most likely mechanism of 4-hydroxyphenylpyruvate dioxygenase involves electrophilic attack on the C1 carbon of the ring and subsequent single-step heterolytic migration of the substituent. Computed values of the kinetic isotope effect for this step are inverse, consistent with available experimental data. Electronic structure arguments for the preferred mechanism of attack on the ring are also presented.

Purine nucleoside phosphorylase activity decline is linked to the decay of the trimeric form of the enzyme.

Homotrimeric mammalian purine nucleoside phosphorylase (PNP) plays a key role in the nucleoside and nucleotide metabolic salvage pathway. Each monomer in the active PNP trimer is composed of a central ß-sheet flanked by several α-helices. We investigated the stability of calf PNP using analytical ultracentrifugation, differential scanning calorimetry, circular dichroism, and UV absorption spectroscopy. The results demonstrate that the activity decline (due to protein aging after isolation from cells) of wild type PNP and its two mutants with point mutations in the region of monomer-monomer interface, is accompanied by a decrease of the population of the trimeric enzyme and an increase of the population of its aggregated forms. The data do not indicate a significant population of either folded or unfolded PNP monomers. The enzyme with specific activity lower than the maximal shows a decrease of the helical structure, which can make it prone to aggregation. The presence of phosphate stabilizes the enzyme but leads to a more pronounced aggregation above the melting temperature. These results suggest that the biological role of packing of the PNP monomers into a trimeric structure is to provide the stability of the enzyme since the monomers are not stable in solution.

Contents of Macro- and Microelements in Blood Serum and Breast Muscle of Turkey Subjected to Pre-Slaughter Transport for Various Distances.

In this study, the effect of pre-slaughter handling on the content of macro- and micronutrients in blood serum and in the breast muscle of turkeys was assessed. Four different variants of pre-slaughter handling were used in the research: no transport (N-T), transport for a distance of 100 km (T-100), transport for a distance of 200 km (T-200), and transport for a distance of 300 km (T-300). In each of them, 30 female and 30 male turkeys were used. Blood was collected from the birds before slaughter, and samples of the pectoral muscle were collected after slaughter. In the obtained biological material, the content of Mg, P, Ca, Fe, Na and K was analyzed. On the basis of the obtained research results, it can be concluded that the pre-slaughter handling negatively affects the content of macro- and microelements both in the blood serum and in the pectoral muscles of experimental turkeys. Additionally, differences due to the sex of birds were observed.

The improvement of the in vitro plant regeneration in barley with the epigenetic modifier of histone acetylation, trichostatin A.

Genotype-limited plant regeneration is one of the main obstacles to the broader use of genetic transformation in barley breeding. Thus, developing new approaches that might improve responses of in vitro recalcitrant genotypes remains at the center of barley biotechnology. Here, we analyzed different barley genotypes, including "Golden Promise," a genotype commonly used in the genetic transformation, and four malting barley cultivars of poor regenerative potential. The expression of hormone-related transcription factor (TF) genes with documented roles in plant regeneration was analyzed in genotypes with various plant-regenerating capacities. The results indicated differential expression of auxin-related TF genes between the barley genotypes in both the explants and the derived cultures. In support of the role of auxin in barley regeneration, distinct differences in the accumulation of free and oxidized auxin were observed in explants and explant-derived callus cultures of barley genotypes. Following the assumption that modifying gene expression might improve plant regeneration in barley, we treated the barley explants with trichostatin A (TSA), which affects histone acetylation. The effects of TSA were genotype-dependent as TSA treatment improved plant regeneration in two barley cultivars. TSA-induced changes in plant regeneration were associated with the increased expression of auxin biosynthesis-involved TFs. The study demonstrated that explant treatment with chromatin modifiers such as TSA might provide a new and effective epigenetic approach to improving plant regeneration in recalcitrant barley genotypes.

Influence of Nb and Mo Substitution on the Structure and Magnetic Properties of a Rapidly Quenched Fe79.4Co5Cu0.6B15 Alloy.

The importance of amorphous and nanocrystalline Fe-based soft magnetic materials is increasing annually. Thus, characterisation of the chemical compositions, alloying additives, and crystal structures is significant for obtaining the appropriate functional properties. The purpose of this work is to present comparative studies on the influence of Nb (1, 2, 3 at.%) and Mo (1, 2, 3 at.%) in Fe substitution on the thermal stability, crystal structure, and magnetic properties of a rapidly quenched Fe79.4Co5Cu0.6B15 alloy. Additional heat treatments in a vacuum (260-640 °C) were performed for all samples based on the crystallisation kinetics. Substantial improvement in thermal stability was achieved with increasing Nb substitution, while this effect was less noticeable for Mo-containing alloys. The heat treatment optimisation process showed that the least lossy states (with a minimum value of coercivity below 10 A/m and high saturation induction up to 1.7 T) were the intermediate state of the relaxed amorphous state and the nanocomposite state of nanocrystals immersed in the amorphous matrix obtained by annealing in the temperature range of 340-360 °C for 20 min. Only for the alloy with the highest thermal stability (Nb = 3%), the α-Fe(Co) nanograin grows, without the co-participation of the hard magnetic Fe3B, in a relatively wide range of annealing temperatures up to 460 °C, where the second local minimum in coercivity and core power losses exists. For the remaining annealed alloys, due to lower thermal stability than the Nb = 3% alloy, the Fe3B phase starts to crystallise at lower annealing temperatures, making an essential contribution to magneto-crystalline anisotropy, thus the substantial increase in coercivity and induction saturation. The air-annealing process tested on the studied alloys for optimal annealing conditions has potential use for this type of material. Additionally, optimally annealed Mo-containing alloys are less lossy materials than Nb-containing alloys in a frequency range up to 400 kHz and magnetic induction up to 0.8 T.

Engineering the surface of Nbn+1CnTx MXenes to versatile bio-activity towards microorganisms.

Two-dimensional (2D) transition metal carbides/nitrides (MXenes) are potential antibacterial agents. However, their activity against microorganisms is not fully understood. It could relate to MXenes' surface which further influences their biocidal action. Herein, we report no continuous biocidal activity for delaminated 2D niobium-based MXenes (Nbn+1XnTx) such as Nb2CTx and Nb4C3Tx prepared with HF/TMAOH protocol. Biocidal activity towards Bacillus subtilis and Staphylococcus aureus microorganisms was achieved by surface-functionalization with lysozyme macromolecule. MXenes' engineering with lysozyme changed MXene's surface charge from negative into positive thus enabling the elimination of bacteria cells during 48 h of incubation. In contrast, Nb4C3Tx functionalized with collagen stimulated the growth of Bacillus subtilis by 225 %, showing MXene's biocompatibility towards this particular strain. Altogether, our results show that MXenes are incredibly bio-tunable. Opposing bio-effects such as antimicrobial or growth-stimulating can be achieved towards various microorganisms with rational surface engineering.

Variables Associated with Attitudes toward Biodebridement Using Lucilia sericata Larvae in a Group of Nurses.

Despite numerous studies and recommendations, the acceptance of treatments involving medicinal maggots in many clinics has been slow. Several factors may account for this, including the gender of nurses administering the treatment, their level of work experience, and their perceived level of personal stress. The aim of the study was to assess the impact of selected variables (gender, work experience, stress level) on the readiness of nurses to administer maggot debridement therapy (MDT), which is a form of biodebridement. The study population was a cohort of 290 wound care nurses providing specialist care for patients with chronic wounds. It was assumed that the identified variables may determine the implementation of larval therapy in everyday professional practice. A subsample of 35 men and 35 women was further analyzed to determine if gender, work experience, and/or personal stress levels were correlated with attitudes towards the utilization of maggots in biodebridement. Assessment tools included the Perceived Stress Scale (PSS-10) and the MDT 10 Perception Assessment Questionnaire, a protocol by which the subject ranked six wound photographs in order of repulsiveness and responded to questions regarding demographic variables, which include education and work experience. The visual perception of pictures of a wound with larvae is indirectly an indicator of the attitude towards larval therapy. Selection of the photograph with maggots on the wound as the most repulsive image was associated with a personal appraisal of not being ready to implement maggot therapy (chi-square = 8.430, p = 0.015). Low work experience (chi-square = 14.039, df = 4, p = 0.007), and low readiness for MDT (chi-square = 8.430, df = 2, p = 0.015) were also associated with unpreparedness to administer maggot therapy. Neither gender nor perceived stress level were exclusively associated with disgust for maggots or lack of readiness to implement MDT. Low professional experience and a deficit of knowledge in maggot therapy may negatively affect the readiness of nurses to administer biodebridement. Gender and personal stress levels do not affect nurses' readiness to utilize larval therapy.

Ambient Processed rGO/Ti3CNTx MXene Thin Film with High Oxidation Stability, Photosensitivity, and Self-Cleaning Potential.

Solution-based processing offers advantages for producing thin films due to scalability, low cost, simplicity, and benignity to the environment. Here, we develop conductive and photoactivated self-cleaning reduced graphene oxide (rGO)/Ti3CNTx MXene thin films via spin coating under ambient conditions. The addition of a thin rGO layer on top of Ti3CNTx resulted in up to 45-fold improvement in the environmental stability of the film compared to the bare Ti3CNTx film. The optimized rGO/Ti3CNTx thin film exhibits an optical transmittance of 74% in the visible region of the spectrum and a sheet resistance of 19 kΩ/sq. The rGO/Ti3CNTx films show high rhodamine B discoloration activity upon light irradiation. Under UV irradiation, the electrically conductive MXene in combination with in situ formed semiconducting titanium oxide induces photogenerated charge carriers, which could potentially be used in photocatalysis. On the other hand, due to film transparency, white light irradiation can bleach the adsorbed dye via photolysis. This study opens the door for using MXene thin films as multifunctional coatings with conductive and potentially self-cleaning properties.