From electrochemical potentiodynamic and potentiostatic techniques, the electrodeposition mechanism and kinetics of palladium nanoparticles (PdNPs) onto a glassy carbon electrode (GCE), from Pd(II) ...ions dissolved in the choline chloride–urea deep eutectic solvent (reline) at 343 K, are reported for the first time. From the analysis of the potentiostatic current density transients, using the model developed by Palomar-Pardavé et al. Electrochim. Acta, 2005, 50, 4736−4745 , it shows that the PdNPs electrodeposition occurs by multiple 3D nucleation and diffusion controlled-growth with the simultaneous reduction of residual water on the PdNPs growing surfaces. This model renders not just the quantification of the palladium nucleation kinetics parameters, but it effectively allows deconvolving the individual contributions to the total current and, thus, from the integration of the j–t plots of these contributions. It was demonstrated that the charge amount of each process depends on the deposition time and applied overpotential. From SEM images, it was possible to verify that the palladium deposits were constituted by PdNPs and from XPS measurements that these PdNPs were formed by a metallic palladium (core) and Pd(OH)2 (shell).
Pd and PdM (M = Fe or Co) nanostructured electrocatalysts were synthesized by the impregnation method and supported on carbon black Vulcan XC-72R for the formic acid oxidation reaction, FAOR, in acid ...medium. Nitrates or chlorides were used as Fe and Co precursors to study the counter ion role on the physicochemical features and electrochemical performance of the electrocatalysts. TEM analysis showed that PdM was deposited on the carbon material with a particle size around 2–3 nm. From XRD, peaks associated with the fcc palladium planes were observed along with evidence of PdM alloy formation, particularly when the nitrate salts were used as metal precursors. Furthermore, XPS analyses indicated that nitrates promote the metal oxide formation to a greater extent than chlorides, mainly for Pd. PdCo electrocatalyst obtained from nitrates exhibited the highest performance for FAOR with a steady state current density of 451 and 313 μA cm−2 at 200 and 400 mV respectively, which is in both cases, 3 times larger than that developed for a commercial Pd/C catalyst.
Display omitted
•Pd and PdM (M = Fe and Co) electrocatalysts were synthesized by impregnation method.•Nitrates or chlorides were used as Fe and Co precursors.•XRD and TEM showed formation of Pd and PdM alloy nanoparticles.•Nitrates favored metal oxides formation.•PdCo-N/C exhibited the highest performance for FAOR.
Display omitted
•Candida glabrata displays niche-specific phenotypic variability within the host.•Candida glabrata clinical isolates can acquire genotypic changes during infection of the host.•There ...is microevolution of Candida glabrata during an infection.•Phenotypic and genotypic changes in C. glabrata can occur during an infection.
Candida glabrata (Nakaseomyces glabrata) is an emergent and opportunistic fungal pathogen that colonizes and persists in different niches within its human host. In this work, we studied five clinical isolates from one patient (P7), that have a clonal origin, and all of which come from blood cultures except one, P7-3, obtained from a urine culture. We found phenotypic variation such as sensitivity to high temperature, oxidative stress, susceptibility to two classes of antifungal agents, and cell wall porosity. Only isolate P7-3 is highly resistant to the echinocandin caspofungin while the other four isolates from P7 are sensitive. However, this same isolate P7-3, is the only one that displays susceptibility to fluconazole (FLC), while the rest of the isolates are resistant to this antifungal. We sequenced the PDR1 gene which encodes a transcription factor required to induce the expression of several genes involved in the resistance to FLC and found that all the isolates encode for the same Pdr1 amino acid sequence except for the last isolate P7-5, which contains a single amino acid change, G1099C in the putative Pdr1 transactivation domain. Consistent with the resistance to FLC, we found that the CDR1 gene, encoding the main drug efflux pump in C. glabrata, is highly overexpressed in the FLC-resistant isolates, but not in the FLC-sensitive P7-3. In addition, the resistance to FLC observed in these isolates is dependent on the PDR1 gene. Additionally, we found that all P7 isolates have a different proportion of cell wall carbohydrates compared to our standard strains CBS138 and BG14. In P7 isolates, mannan is the most abundant cell wall component, whereas β-glucan is the most abundant component in our standard strains. Consistently, all P7 isolates have a relatively low cell wall porosity compared to our standard strains.
These data show phenotypic and genotypic variability between clonal isolates from different niches within a single host, suggesting microevolution of C. glabrata during an infection.
Who let the dog in? Smith, Charlotte L.; Marmolejo Pizarro, Jhanny L.; Blaise, Benjamin J. ...
Pediatric anesthesia,
December 2021, 2021-12-00, 20211201, Letnik:
31, Številka:
12
Journal Article
Vascular assessment is a critical component of wound care. Current routine noninvasive vascular studies have limitations which can give a false sense of security of the presence of adequate perfusion ...for healing. Near-infrared imaging modalities can serve as an additional diagnostic assessment of wounds in which adequate perfusion is a concern. Correct interpretation of near-infrared images obtained is critical as subtleties that exist in the acute and chronic wound population goes beyond the interpretation that increased signal is consistent with adequate perfusion for healing. The objective of this paper is to educate providers on the correct interpretation of this point-of-care imaging modality in day-to-day wound-care practice to guide clinical decision-making for rapid wound resolution.
The hematopoietic system produces a large number of highly specialized cell types that are derived through a hierarchical differentiation process from a common stem cell population. miRNAs are ...critical players in orchestrating this differentiation. Here, we report the development and application of a high-throughput microfluidic real-time quantitative PCR (RT-qPCR) approach for generating global miRNA profiles for 27 phenotypically distinct cell populations isolated from normal adult mouse hematopoietic tissues. A total of 80,000 RT-qPCR assays were used to map the landscape of miRNA expression across the hematopoietic hierarchy, including rare progenitor and stem cell populations. We show that miRNA profiles allow for the direct inference of cell lineage relations and functional similarity. Our analysis reveals a close relatedness of the miRNA expression patterns in multipotent progenitors and stem cells, followed by a major reprogramming upon restriction of differentiation potential to a single lineage. The analysis of miRNA expression in single hematopoietic cells further demonstrates that miRNA expression is very tightly regulated within highly purified populations, underscoring the potential of single-cell miRNA profiling for assessing compartment heterogeneity.
Palladium nanoparticles (PdNPs) were formed and supported onto the surface of a glassy carbon electrode (GCE) from a single potentiostatic step using palladium chloride (PdCl2) as the precursor salt, ...dissolved in a deep eutectic mixture formed by 2-Hydroxy-N,N,N-trimethylethanaminium chloride (choline chloride) and diaminomethanal (urea). Analysis of the potentiostatic current density transients allows to accurately establish the amount of Pd deposited on the GCE surface required to determine the so-called mass activity, as defined by the ratio between methanoic acid (formic acid) oxidation current and palladium mass electrodeposited on the electrode. From SEM analysis of the GCE surface modified with PdNPs, it was found that PdNPs were distributed uniformly over the electrode surface, having an average size of (60 ± 9) nm. EDX and XPS analysis confirm a core-shell morphology constituted by a Pd core surrounded by a palladium (II) Hydroxide- palladium (II) oxide (Pd(OH)2-PdO) shell. The GCE modified with PdNPs (GCE/PdNPs) were used to oxidize formic acid from aqueous electrolytic baths added with perchloric acid (HClO4) or sulfuric acid (H2SO4). It was shown that the maximum mass activity depended on both, the nature of the electrolytic bath and the applied potential for the PdNPs electrodeposition. However, the best mass activity ((5085 ± 129) mA mgPd−1) was achieved with the GCE/PdNPs, formed at −700 mV vs. the silver quasi reference electrode (Ag QRE), immersed in the HClO4 electrolytic bath, even when the formic acid concentration was half that used in the H2SO4 electrolytic bath. Furthermore, the mass activities of the PdNPs reported in this work rank high among other values reported in the literature for nanoparticles based on palladium but synthesized with more complex and expensive processes, having the advantage of being obtained by a simple, rapid, and cost-effective electrochemical method.
Display omitted
•PdNPs were electrodeposited onto GCE from a deep eutectic solvent.•Pd@Pd(OH)2 was the core-shell structure from SEM and XPS.•Pd@Pd(OH)2 mass activity towards FAOR in acid media was evaluated.•Pd@Pd(OH)2 exhibited outstanding mass activity toward FAOR.
The design of render-mortars from construction and demolition waste (CDW) was evaluated. Fine aggregates from red-clay-brick waste, mortar and concrete waste were used, together with recycled ...expanded-polystyrene (EPS) as lightweight filler. Mixes composed of 70%-recycled aggregates, and 30% consisting of a matrix of Portland cement were produced. Characterization tests were conducted on the physical, mechanical, thermal, and acoustic properties. The render-mortar A4, A7 and A9 can be classified according to compressive strength results as CSI-W0 for interior use under standard UNE-EN-998-1. The A7 mortar, with the best physical and mechanical results, contained 21% EPS, 17.5% brick waste and 17.5% mortar waste. Mix A4 obtained the lowest thermal conductivity, 0.12 W/m·K - a reduction of 79% compared to the commercial-mortar AC1. The acoustic absorption properties were also enhanced by the incorporation of EPS, such that the A4, A7, and A9 mixes were identified as Absorbent for the frequencies of 2000 Hz and 4000 Hz.
No standard definition for a completely healed wound currently exists; it is recommended that providers use a reliable wound assessment tool to determine healing. The objective of this feasibility ...study was to determine if a point-of-care, noncontact, near-infrared (NIR) imaging device could provide an objective measure of wound resolution and guide clinical decision-making for the optimal time to transition from protective wound dressings and gradual return to full activity.
In this single-center feasibility study, adult patients 18 years and older with a lower extremity wound of any size and etiology were seen weekly for wound assessment and standard-of-care treatment. The researchers performed serial imaging with a point-of-care, noncontact, NIR imaging device (Snapshot NIR ; Kent Imaging Inc) to assess the wound and surrounding skin and evaluated the difference in time to 100% reepithelialization on visual inspection and homogeneous tissue oxygen saturation levels at the wound site and surrounding closed skin envelope.
An average time difference of 13.5 ± 10 days (median, 12 days; range, 0-35 days) was observed between 100% reepithelialization on visual wound inspection and imaging assessment. Further, NIR imaging could determine when a patient was at risk for recurrent wound breakdown.
The addition of point-of-care, noncontact, NIR imaging may help guide clinical decision-making for the optimal time to transition from protective wound dressings with gradual return to full activity and minimize wound recurrence.
•On-site and laboratory stability, maturity tests were performed on 2 compost piles.•Some on-site tests were not consistent with the findings at laboratory scale.•Stability was detected in some ...samples that were, however, immature.•No strong correlations were found between stability and maturity indices.
Stability and maturity are important criteria to guarantee the quality of a compost that is applied to agriculture or used as amendment in degraded soils. Although different techniques exist to evaluate stability and maturity, the application of laboratory tests in municipalities in developing countries can be limited due to cost and application complexities. In the composting facilities of such places, some classical low cost on-site tests to monitor the composting process are usually implemented; however, such tests do not necessarily clearly identify conditions of stability and maturity. In this article, we have applied and compared results of stability and maturity tests that can be easily employed on site (i.e. temperature, pH, moisture, electrical conductivity EC, odor and color), and of tests that require more complex laboratory techniques (volatile solids, C/N ratio, self-heating, respirometric index, germination index GI). The evaluation of the above was performed in the field scale using 2 piles of biowaste applied compost. The monitoring period was from day 70 to day 190 of the process. Results showed that the low-cost tests traditionally employed to monitor the composting process on-site, such as temperature, color and moisture, do not provide consistent determinations with the more complex laboratory tests used to assess stability (e.g. respiration index, self-heating, volatile solids). In the case of maturity tests (GI, pH, EC), both the on-site tests (pH, EC) and the laboratory test (GI) provided consistent results. Although, stability was indicated for most of the samples, the maturity tests indicated that products were consistently immature. Thus, a stable product is not necessarily mature. Conclusively, the decision on the quality of the compost in the installations located in developing countries requires the simultaneous use of a combination of tests that are performed both in the laboratory and on-site.
PDF
