Green Nanocoatings Based on the Deposition of Zirconium Oxide: The Role of the Substrate

Herein, the influence of the substrate in the formation of zirconium oxide monolayer, from an aqueous hexafluorozirconic acid solution, by chemical conversion and by electro-assisted deposition, has been approached. The nanoscale dimensions of the ZrO₂ film is affected by the substrate nature and roughness. This study evidenced that the mechanism of Zr-EAD is dependent on the potential applied and on the substrate composition, whereas conversion coating is uniquely dependent on the adsorption reaction time. The zirconium oxide based nanofilms were more homogenous in AA2024 substrates if compared to pure Al grade (AA1100). It was justified by the high content of Cu alloying element present in the grain boundaries of the latter. Such intermetallic active sites favor the obtaining of ZrO₂ films, as demonstrated by XPS and AFM results. From a mechanistic point of view, the electrochemical reactions take place simultaneously with the conventional chemical conversion process driven by ions diffusion. Such findings will bring new perspectives for the generation of controlled oxide coatings in modified electrodes used, as for example, in the construction of battery cells; in automotive and in aerospace industries, to replace micrometric layers of zinc phosphate by light-weight zirconium oxide nanometric ones. This study is particularly addressed for the reduction of industrial waste by applying green bath solutions without the need of auxiliary compounds and using lightweight ceramic materials.     

The Widened Pipe Model of plant hydraulic evolution

Shaping global water and carbon cycles, plants lift water from roots to leaves through xylem conduits. The importance of xylem water conduction makes it crucial to understand how natural selection deploys conduit diameters within and across plants. Wider conduits transport more water but are likely more vulnerable to conduction-blocking gas embolisms and cost more for a plant to build, a tension necessarily shaping xylem conduit diameters along plant stems. We build on this expectation to present the Widened Pipe Model (WPM) of plant hydraulic evolution, testing it against a global dataset. The WPM predicts that xylem conduits should be narrowest at the stem tips, widening quickly before plateauing toward the stem base. This universal profile emerges from Pareto modeling of a trade-off between just two competing vectors of natural selection: one favoring rapid widening of conduits tip to base, minimizing hydraulic resistance, and another favoring slow widening of conduits, minimizing carbon cost and embolism risk. Our data spanning terrestrial plant orders, life forms, habitats, and sizes conform closely to WPM predictions. The WPM highlights carbon economy as a powerful vector of natural selection shaping plant function. It further implies that factors that cause resistance in plant conductive systems, such as conduit pit membrane resistance, should scale in exact harmony with tip-to-base conduit widening. Furthermore, the WPM implies that alterations in the environments of individual plants should lead to changes in plant height, for example, shedding terminal branches and resprouting at lower height under drier climates, thus achieving narrower and potentially more embolism-resistant conduits.

Water transport through plants is a key driver of the carbon and other biogeochemical cycles (1–3) and is a crucial link in plant adaptation to climate and vegetation response to climate change (4–9). The water conducting cells of plants, xylem conduits, widen with distance from the stem tip, and, therefore, taller plants have wider conduits (6, 10–12). Xylem conduits are of two main types: tracheids, found in most gymnosperms, and vessels, found in most flowering plants. Tracheids have intact cell membranes, so water must flow from cell to cell through these membranes. Vessels are made up of cells aligned vertically end to end, with the cell membranes dissolved between successive members, forming a tube. Whatever their differences in structure, wider conduits are beneficial because they conduct more water. Tip-to-base widening is expected to help maintain conductance per unit leaf area constant as an individual plant grows taller, counterbalancing the resistance that would otherwise accrue with increasing conductive path length the individual grows (2, 13). Wider conduits, however, are more vulnerable to embolisms caused by cold and likely drought (8, 14–18) and cost more in terms of carbon for a plant (ref. 1; cf. ref. 19). Embolisms in the xylem even affect transport of photosynthates in the phloem (8, 20). This means that as trees grow taller, conductance, embolism vulnerability, and carbon costs must interrelate in a delicate evolutionary balance.Because of the importance of this balance in plant hydraulic evolution and in forest reactions to climate change (3, 6, 21–23), an important goal of plant biology is to construct models that predict how and why plants deploy conduit diameters throughout their bodies (1, 2, 17, 24–26). Some models predict that conduits should be of uniform diameter (27, 28), while others predict that they should widen tip to base (1, 2, 13, 24, 29, 30). But even current models include untested assumptions and large numbers of parameters, making it difficult to identify the biological causes of the predictions they make. For example, some invoke Da Vinci’s rule, the largely untested assumption that the summed wood area of the twigs is the same as that at the base (24, 26). Other models depict plant conduits as branching as they do in mammalian circulatory systems, but whether this happens along the entire stem in plants is unclear (30–33). There is an expectation that conduit diameter D should widen with distance from the stem tip L following a power-law (D ∝ L^b), but there is no agreement on the value of b, the conduit widening exponent (1, 2). Furthermore, even though within-individual tip-to-base conduit widening has been confirmed in a handful of species (34–36), and the scaling of conduit diameter with plant size across species is consistent with it (6, 10–12, 34), the expectation that conduits should widen similarly within stems across terrestrial vascular plant lineages and habits has yet to be empirically confirmed. Here we present the Widened Pipe Model (WPM), which correctly predicts the form of tip-to-base conduit widening across the span of plant size, life form, and habitat across the terrestrial plant phylogeny.     

Prediction of unexpected sudden death among healthy dogs by a novel marker of autonomic neural activity

BACKGROUND: Unexpected sudden death among apparently healthy individuals remains a daunting problem. We have previously shown that autonomic modulation of cardiac arrhythmias and autonomic markers, such as baroreflex sensitivity (BRS) and heart rate variability (HRV), carry predictive power after myocardial infarction. OBJECTIVE: We tested the hypothesis that a parameter combining BRS and HRV could predict risk for ventricular fibrillation (VF) during a first ischemic episode in otherwise healthy dogs. METHODS: In 43 fully instrumented dogs, BRS and frequency domain analysis of HRV were determined, as well as the occurrence (n = 10, high-risk) or absence (n = 33, low-risk) of VF during 2 minutes of myocardial ischemia superimposed on submaximal exercise. TARVA (Tonic and Reflex Vagal Activity), expressed in units, is the parameter resulting from the multiplication of BRS by HF/LF (an index of tonic vagal activity). RESULTS: High-risk dogs had markedly lower TARVA values, reflecting lower cardiac vagal activity, than low-risk animals (12 +/- 5 versus 56 +/- 43 units, P < .001). The area under the receiver-operator characteristic curve for TARVA was 0.96 (95% confidence interval 0.86 to 0.99); its optimal cutoff had a 100% sensitivity and a 88% specificity with positive and negative predictive values of 71% and 100%, respectively. CONCLUSION: Differences in cardiac autonomic activity, present in healthy dogs, allow prediction of arrhythmic risk during a first ischemic episode. Increased risk is associated with reduced vagal activity. If confirmed in humans, this finding would open the way to the identification of those apparently healthy subjects at risk for sudden cardiac death during their first episode of myocardial ischemia.     

Cytomegalovirus maculopapular eruption in a kidney transplant patient

Abstract: Cytomegalovirus (CMV) is the most important viral agent in kidney transplantation. Clinical manifestations of CMV disease in transplantation include hepatitis, pneumonitis, pancreatitis, kidney allograft dysfunction, colitis, and meningoencephalitis. However, skin involvement is rare. We describe a severely compromised cadaveric‐kidney transplant recipient who developed renal failure, colonic ulcers, and a maculopapular rash accompanied by fever and malaise 4 months after transplantation. Only the skin biopsy was diagnostic and consistent with CMV disease. Intravenous ganciclovir administration resulted in clinical improvement of CMV‐induced skin lesions; kidney function normalized and the patient became asymptomatic after 14 days of ganciclovir therapy. Nephrologists should consider the diagnosis of CMV disease in the febrile immunosuppressed patient with skin involvement. Skin biopsy must be considered as a useful and safe procedure in patients with a rash to obtain a prompt diagnosis and efficiently treat this immunocompromised population.     

Spread of Streptococcus pneumoniae Serotype 8-ST63 Multidrug-Resistant Recombinant Clone,Spain

Since 2004, a total of 131 isolates of Streptococcus pneumoniae multidrug-resistant invasive serotype 8 have been detected in Spain. These isolates showed resistance to erythromycin, clindamycin, tetracycline, and ciprofloxacin. All isolates were obtained from adult patients and shared a common genotype (sequence type [ST]63; penicillin-binding protein 1a [pbp1a], pbp2b, and pbp2x gene profiles; ermB and tetM genes; and a ParC-S79F change). Sixty-eight isolates that required a ciprofloxacin MIC ≥16 μg/mL had additional gyrA gene changes. Serotype 8-ST63 pbp2x sequences were identical with those of antimicrobial drug–susceptible serotype 8-ST53 isolates. Serotype 8-ST63 pbp2b sequences were identical with those of the multidrug-resistant Sweden 15A-ST63 clone. Recombination between the capsular locus and flanking regions of an ST53 isolate (donor) and an ST63 pneumococcus (recipient) generated the novel 15A-ST63 clone. One recombination point was upstream of pbp2x and another was within pbp1a. A serotype 8-ST63 clone was identified as a cause of invasive disease in Spain.     

Characterisation of microsatellite markers in the stone curlew Burhinus oedicnemus

We characterized twenty unique polymorphic microsatellite loci in the Eurasian stone curlew Burhinus oedicnemus, a bird of conservation concern in Europe. The loci were genotyped in 24 individuals and displayed between 2 and 21 alleles per locus. All twenty loci were autosomal based on the genotyping of individuals of known sex and seventeen loci were in Hardy–Weinberg equilibrium. These microsatellites will be used to investigate population structure in this species with the aim of informing those responsible for creating conservation management strategies.     

Films based on the biopolymer poly(3-hydroxybutyrate) as platforms for the controlled release of dexamethasone

Controlled drug delivery aims to achieve an effective drug concentration in the action site for a desired period of time, while minimizing side effects. In this contribution, biodegradable poly(3-hydroxybutyrate) films were evaluated as a reservoir platform for dexamethasone controlled release. These systems were morphological and physicochemically characterized. In vitro release assays were performed for five different percentages of drug in the films and data were fitted by a mathematical model developed and validated by our research group. When the profiles were normalized, a single curve properly fitted all the experimental data. Using this unique curve, the dissolution efficiency (DE), the time to release a given amount of drug (t_X%), and the mean dissolution time were calculated. Furthermore, the dissolution rate, the initial dissolution rate (a%) and the intrinsic dissolution rate were determined. The a% mean value was 1.968 × 10^?2% released/min, t_80% was about 14 days, and the DE was 59.6% at 14 days and 66.5% at 20 days. After 2 days, when approximately 40% of the drug was released, the dissolution rate decreased about 60% respect to the initial value. The poly(3-hydroxybutyrate) platforms behaved as an appropriate system to release and control the dexamethasone delivery, suggesting that they could be an alternative to improve drug therapy.     

Interval between neoadjuvant treatment and definitive surgery in locally advanced rectal cancer: impact on response and oncologic outcomes

Purpose

The optimal waiting period between neoadjuvant treatment completion and surgery in locally advanced rectal cancer (LARC) is controversial. The specific purpose of this study was to evaluate the effect of prolonging this interval on the pathologic response, postoperative morbidity, and long-term oncologic outcomes.

Methods

Retrospective data analysis is reported from LARC patients who had been treated with chemoradiation followed by surgery and intra-operative radiotherapy, between February 1995 and December 2012. In total, two groups were studied, according to the time elapsed between neoadjuvant treatment and surgery: conventional interval (CI; <6 weeks) and delayed interval (DI; ≥6 weeks). Clinicopathological data related to tumor response, postoperative morbidity, and oncologic outcomes were compared.

Results

This study included 335 consecutive LARC patients. There was a higher proportion of patients with clinical staging nodal involvement (cN+) in the DI group (76.6 vs. 64.1 %; p = 0.01). The pathologic complete response (pCR) was not significantly different among groups (8.8 vs. 12.1 %; p = 0.34). Longer intervals did not affect complication incidence or severity or hospital admission length. Certain postneoadjuvant tumor effect parameters were significantly increased in the DI group, including N-downstaging and T-downsizing. After a median follow-up of 71 months, patients in the DI group presented with superior 5-year overall survival (OS) (55.9 vs. 70.4 %, p = 0.014); however, no statistically significant differences were observed in 5-year disease-free survival (DFS) or 5-year local control (LC) (69.9 vs. 74.9 %, p = 0.223; 90.4 vs. 94.5 %, p = 0.123, respectively).

Conclusions

A modest surgical interval delay (≥6 weeks) did not increase postoperative complications and was identified as a favorable prognostic factor for OS, although no differences were observed in pCR, LC, or DFS. Innovative multidisciplinary strategies incorporating further time extension of the surgical interval can be safely explored.