Designing an Oxygen Scavenger Multilayer System Including Volatile Organic Compound (VOC) Adsorbents for Potential Use in Food Packaging

Oxygen scavengers are valuable active packaging systems because several types of food deterioration processes are initiated by oxygen. Although the incorporation of oxygen scavenger agents into the polymeric matrices has been the trend in recent years, the release of volatile organic compounds (VOC) as a result of the reaction between oxygen and oxygen scavenger substances is an issue to take into account. This is the case of an oxygen scavenger based on a trans-polyoctenamer rubber (TOR). In this work, the design of an oxygen scavenger multilayer system was carried out considering the selection of appropriate adsorbents of VOCs to the proposed layer structure. Firstly, the retention of some representative organic compounds by several adsorbent substances, such as zeolites, silicas, cyclodextrins and polymers, was studied in order to select those with the best performances. A hydrophilic silica and an odor-adsorbing agent based on zinc ricinoleate were the selected adsorbing agents. The principal VOCs released from TOR-containing films were carefully identified, and their retention first by the pure adsorbents, and then by polyethylene incorporated with the selected compounds was quantified. Detected concentrations decreased by 10- to 100-fold, depending on the VOC.

Tuning Magnetoconductivity in LaMnO3 NPs through Cationic Vacancy Control

The inclusion of La-Mn vacancies in LaMnO₃ nanoparticles leads to a noticeable change in conductivity behavior. The sample retains its overall insulator characteristic, with a typical thermal activation mechanism at high temperatures, but it presents high magnetoconductivity below 200 K. The activation energy decreases linearly with the square of the reduced magnetization and vanishes when the sample is magnetized at saturation. Therefore, it turns out that electron hopping between Mn³⁺ and Mn⁴⁺ largely contributes to the conductivity below the Curie temperature. The influence of the applied magnetic field on conductivity also supports the hypothesis of hopping contribution, and the electric behavior can be explained as being due to an increase in the hopping probability via spin alignment.

Straightforward Synthesis of Bis[(trifluoromethyl)sulfonyl]ethylated Isocoumarins from 2-Ethynylbenzoates

Herein, we report a facile isocoumarin and isoquinolone preparation by taking advantage of an initial bis(triflyl)ethylation [triflyl = (trifluoromethyl)sulfonyl] reaction, followed by heterocyclization, which contrasts with our previous results on cyclobutene formation. The efficiency of the catalyst- and irradiation-free heterocyclization/bis(triflyl)ethylation sequence showed exquisite dependence on the electronic nature of the substituents at the 2-ethynylbenzoate(benzamide) precursors. Molecular docking of model bis(triflyl)ethylated isocoumarins on human acetylcholinesterase (hAChE) revealed promising biological activities through selective coordination on both the catalytic active site and peripheral active site.

Improving the Efficacy of Quinolylnitrones for Ischemic Stroke Therapy, QN4 and QN15 as New Neuroprotective Agents after Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury

In our search for new neuroprotective agents for stroke therapy to improve the pharmacological profile of the compound quinolylnitrone QN23, we have prepared and studied sixteen new, related and easily available quinolylnitrones. As a result, we have identified compounds QN4 and QN15 as promising candidates showing high neuroprotection power in a cellular experimental model of ischemia. Even though they were found to be less active than our current lead compound QN23, QN4 and QN15 provide an improved potency and, particularly for QN4, an expanded range of tolerability and improved solubility compared to the parent compound. A computational DFT-based analysis has been carried out to understand the antioxidant power of quinolylnitrones QN23, QN4 and QN15. Altogether, these results show that subtle, simple modifications of the quinolylnitrone scaffold are tolerated, providing high neuroprotective activity and optimization of the pharmacological potency required for an improved design and future drug developments in the field.

Coexistence of Two Spin Frustration Pathways in the Quantum Spin Liquid Ca10Cr7O28

Kagome antiferromagnetic lattices are of high interest because the geometric frustration is expected to give rise to highly degenerated ground states that may host exotic properties such as quantum spin liquid (QSL). Ca₁₀Cr₇O₂₈ has been reported to display all the features expected for a QSL. At present, most of the literature reports on samples synthesized with starting materials ratio CaO/Cr₂O₃ 3:1, which leads to a material with small amounts of CaCrO₄ and CaO as secondary phases; this impurity excess affects not only the magnetic properties but also the structural ones. In this work, samples with starting material ratios CaO/Cr₂O₃ 3:1, 2.9:1, 2.85:1, and 2.8:1 have been synthesized and studied by X-ray diffraction with Rietveld refinements, selected area electron diffraction measurements, high-resolution transmission electron microscopy (HRTEM), low-temperature magnetometry, and magnetic calorimetry. This result shows that a highly pure Ca₁₀Cr₇O₂₈ phase is obtained for a CaO/Cr₂O₃ ratio of 2.85:1 instead of the 3:1 usually reported; the incorrect stoichiometric ratio leads to a larger distortion of the corner-sharing triangular arrangement of magnetic ions Cr⁺⁵ with S = 1/2 in the Kagome lattice. In addition, our study reveals that there exists another frustration pathway which is an asymmetric zigzag spin ladder along the directions [211], [12–1], and [1–1–1], in which the Cr–Cr distances are shorter than in the Kagome layers.

This work represents the endeavor to ensure the correct stoichiometric composition of the quantum spin liquid material Ca₁₀Cr₇O₂₈. The synthesis and characterization addressed several nonstoichiometric samples, including impurities’ influence on the crystal structure and properties of Kagome and zigzag magnetic interaction. The characterization aspects of the compound are based on the X-ray diffraction data and Rietveld refinement. Further characterization could help us understand the nature of quantum material and aid in the additional development of quantum theories and technology.

Privileged Quinolylnitrones for the Combined Therapy of Ischemic Stroke and Alzheimer's Disease

Cerebrovascular diseases such as ischemic stroke are known to exacerbate dementia caused by neurodegenerative pathologies such as Alzheimer’s disease (AD). Besides, the increasing number of patients surviving stroke makes it necessary to treat the co-occurrence of these two diseases with a single and combined therapy. For the development of new dual therapeutic agents, eight hybrid quinolylnitrones have been designed and synthesized by the juxtaposition of selected pharmacophores from our most advanced lead-compounds for ischemic stroke and AD treatment. Biological analyses looking for efficient neuroprotective effects in suitable phenotypic assays led us to identify MC903 as a new small quinolylnitrone for the potential dual therapy of stroke and AD, showing strong neuroprotection on (i) primary cortical neurons under oxygen–glucose deprivation/normoglycemic reoxygenation as an experimental ischemia model; (ii), neuronal line cells treated with rotenone/oligomycin A, okadaic acid or β-amyloid peptide Aβ_25–35, modeling toxic insults found among the effects of AD.

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

The allene functionality has participated in one of the most exciting voyages in organic chemistry, from chemical curiosities to a recurring building block in modern organic chemistry. In the last decades, a special kind of allene, namely, allenol, has emerged. Allenols, formed by an allene moiety and a hydroxyl functional group with diverse connectivity, have become common building blocks for the synthesis of a wide range of structures and frequent motif in naturally occurring systems. The synergistic effect of the allene and hydroxyl functional groups enables allenols to be considered as a unique and sole functionality exhibiting a special reactivity. This Review summarizes the most significant contributions to the chemistry of allenols that appeared during the past decade, with emphasis on their synthesis, reactivity, and occurrence in natural products.

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry

On-surface synthesis has recently been regarded as a promising approach for the generation of new molecular structures. It has been particularly successful in the synthesis of graphene nanoribbons, nanographenes and intrinsically reactive and instable, yet attractive species. It is based on the combination of solution chemistry aimed at preparation of appropriate molecular precursors for further ultra-high vacuum surface assisted transformations. This approach also owes its success to an incredible development of characterization techniques, such as scanning tunneling/atomic force microscopy and related methods, which allow detailed, local characterization at atomic scale. While the surface-assisted synthesis can provide molecular nanostructures with outstanding precision, down to single atoms, it suffers from basing on metallic surfaces and often limited yield. Therefore, the extension of the approach away from metals and the struggle to increase productivity seem to be significant challenges toward wider applications. Herein, we demonstrate the on-surface synthesis approach for generation of non-planar nanographenes, which are synthesized through a combination of solution chemistry and sequential surface-assisted processes, together with the detailed characterization by scanning probe microscopy methods.

Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms

Ovule primordia formation is a complex developmental process with a strong impact on the production of seeds. In Arabidopsis this process is controlled by a gene network, including components of the signalling pathways of auxin, brassinosteroids (BRs) and cytokinins. Recently, we have shown that gibberellins (GAs) also play an important role in ovule primordia initiation, inhibiting ovule formation in both Arabidopsis and tomato. Here we reveal that BRs also participate in the control of ovule initiation in tomato, by promoting an increase on ovule primordia formation. Moreover, molecular and genetic analyses of the co-regulation by GAs and BRs of the control of ovule initiation indicate that two different mechanisms occur in tomato and Arabidopsis. In tomato, GAs act downstream of BRs. BRs regulate ovule number through the downregulation of GA biosynthesis, which provokes stabilization of DELLA proteins that will finally promote ovule primordia initiation. In contrast, in Arabidopsis both GAs and BRs regulate ovule number independently of the activity levels of the other hormone. Taken together, our data strongly suggest that different molecular mechanisms could operate in different plant species to regulate identical developmental processes even, as for ovule primordia initiation, if the same set of hormones trigger similar responses, adding a new level of complexity.

Identification of relapse-associated gene mutations by next-generation sequencing in low-risk acute myeloid leukaemia patients

Recommended genetic categorization of acute myeloid leukaemias (AML) includes a favourable-risk category, but not all these patients have good prognosis. Here, we used next-generation sequencing to evaluate the mutational profile of 166 low-risk AML patients: 30 core-binding factor (CBF)-AMLs, 33 nucleophosmin (NPM1)-AMLs, 4 biCEBPα-AMLs and 101 acute promyelocytic leukaemias (APLs). Functional categories of mutated genes differed among subgroups. NPM1-AMLs showed frequent variations in DNA-methylation genes (DNMT3A, TET2, IDH1/2) (79%), although without prognostic impact. Within this group, splicing-gene mutations were an independent factor for relapse-free (RFS) and overall survival (OS). In CBF-AML, poor independent factors for RFS and OS were mutations in RAS pathway and cohesin genes, respectively. In APL, the mutational profile differed according to the risk groups. High-risk APLs showed a high mutation rate in cell-signalling genes (P = 0·002), highlighting an increased incidence of FLT3 internal tandem duplication (ITD) (65%, P < 0·0001). Remarkably, in low-risk APLs (n = 28), NRAS mutations were strongly correlated with a shorter five-year RFS (25% vs. 100%, P < 0·0001). Overall, a high number of mutations (≥3) was the worst prognostic factor RFS (HR = 2·6, P = 0·003). These results suggest that gene mutations may identify conventional low-risk AML patients with poor prognosis and might be useful for better risk stratification and treatment decisions.

Chromenones as Multineurotargeting Inhibitors of Human Enzymes

The complex nature of multifactorial diseases, such as Morbus Alzheimer, has produced a strong need to design multitarget-directed ligands to address the involved complementary pathways. We performed a purposive structural modification of a tetratarget small-molecule, that is contilisant, and generated a combinatorial library of 28 substituted chromen-4-ones. The compounds comprise a basic moiety which is linker-connected to the 6-position of the heterocyclic chromenone core. The syntheses were accomplished by Mitsunobu- or Williamson-type ether formations. The resulting library members were evaluated at a panel of seven human enzymes, all of which being involved in the pathophysiology of neurodegeneration. A concomitant inhibition of human acetylcholinesterase and human monoamine oxidase B, with IC₅₀ values of 5.58 and 7.20 μM, respectively, was achieved with the dual-target 6-(4-(piperidin-1-yl)butoxy)-4H-chromen-4-one (7).

Synthesis and reactivity of a trigonal porous nanographene on a gold surface

Synthesis of a triporous nanographene with 102 sp² carbon atoms by combining solution and surface chemistry.

The synthesis of porous nanographenes is a challenging task for solution chemistry, and thus, on-surface synthesis provides an alternative approach. Here, we report the synthesis of a triporous nanographene with 102 sp² carbon atoms by combining solution and surface chemistry. The carbon skeleton was obtained by Pd-catalyzed cyclotrimerization of arynes in solution, while planarization of the molecule was achieved through two hierarchically organized on-surface cyclodehydrogenation reactions, intra- and inter-blade. Remarkably, the three non-planar [14]annulene pores of this nanographene further evolved at higher temperatures showing interesting intra-porous on-surface reactivity.

Altered nitrogen metabolism in biocontrol strains of Penicillium rubens

The importance of the metabolic route of nitrogen in the fungus Penicillium rubens (strain PO212) is studied in relation to its biocontrol activity (BA). PO212 can resist a high concentration of chlorate anion and displays a classical nitrate-deficiency (nit-) phenotype resulting in poor colonial growth when nitrate is used as the main source of nitrogen. Analyses of genes implicated in nitrate assimilation evidenced the strong sequence conservation of PO212 and CH8 genome with penicillin producers such as reference strain P. rubens Wisconsin 54-1255, P2niaD18 and Pc3, however also revealed the presence of mutations. PO212 carries a mutation in the gene coding for zinc-binuclear cluster transcription factor NirA that specifically mediates the regulation of genes involved in nitrate assimilation. The nirA1 mutation causes an early stop of NirA factor, losing 66% of its sequence. The NirA1 mutant form is unable to mediate a nitrate-dependent regulation of nitrate and nitrite reductase coding genes. In this study, we study another isolate, CH8, with potential BA and nit- phenotype. A mutation in the nitrate permease coding gene crnA was found in CH8. An insertion of a guanine in the coding sequence cause a frameshift in CrnA with the loss of the last two transmembrane domains. Analysis of PO212 and CH8 isolates and complementation strains show the importance of NirA regulator in maintaining correct transcriptional levels of nitrate and nitrite reductases and suggest CrnA as the main nitrate transporter. the presence of alternative transporter for chlorate and the existence of a mechanism for preventing nitrite derived toxicity in Penicillum. BA of PO212 is partially altered when nirA1 mutation was complemented. This result and the finding of CH8, a novel biocontrol P. rubens strain with a nit- phenotype, suggest that nitrogen metabolism is a component of biocontrol capacity.

Complex structural ordering of the oxygen deficiency in La0.5Ca2.5Mn2O7-δ Ruddlesden-Popper phases

Ruddlesden-Popper oxides, (AO)(ABO₃)_n, occupy a prominent place in the landscape of materials research because of their intriguing potential applications. Compositional modifications to the cation sublattices, A or B, have been explored in order to achieve enhanced functionalities. However, changes to the anionic sublattice have been much less explored. In this work, new oxygen-deficient manganese Ruddlesden-Popper-related phases, La_0.5Ca_2.5Mn₂O_6.5 and La_0.5Ca_2.5Mn₂O_6.25, have been synthesized by controlled reduction of the fully oxidized n = 2 term La_0.5Ca_2.5Mn₂O₇. A complete structural and compositional characterization, by means of neutron diffraction, electron diffraction and atomically resolved scanning transmission electron microscopy and electron energy-loss spectroscopy techniques, allows the proposition of a topotactic reduction pathway through preferential oxygen removal in the [MnO₂] layers along [031] and [0{\bar 1}3] directions. The gradual decrease of the Mn oxidation state, accommodated by short-range ordering of anionic vacancies, reasonably explains the breaking of ferromagnetic interactions reinforcing the emergence of antiferromagnetic ones. Additional short-range order-disorder phenomena of La and Ca cations have been detected in the reduced La_0.5Ca_2.5Mn₂O_7-δ, as previously reported in the parent compound.

Electronic Resonances and Gap Stabilization of Higher Acenes on a Gold Surface

On-surface synthesis provides a powerful method for the generation of long acene molecules, making possible the detailed investigation of the electronic properties of single higher acenes on a surface. By means of scanning tunneling microscopy and spectroscopy combined with theoretical considerations, we discuss the polyradical character of the ground state of higher acenes as a function of the number of linearly fused benzene rings. We present energy and spatial mapping of the tunneling resonances of hexacene, heptacene, and decacene, and discuss the role of molecular orbitals in the observed tunneling conductance maps. We show that the energy gap between the first electronic tunneling resonances below and above the Fermi energy stabilizes to a finite value, determined by a first diradical electronic perturbative contribution to the polyacene electronic ground state. Up to decacene, the main contributor to the ground state of acenes remains the lowest-energy closed-shell electronic configuration.

Gibberellins negatively modulate ovule number in plants

Ovule formation is a complex developmental process in plants, with a strong impact on the production of seeds. Ovule primordia initiation is controlled by a gene network, including components of the signaling pathways of auxin, brassinosteroids and cytokinins. By contrast, gibberellins (GAs) and DELLA proteins, the negative regulators of GA signaling, have never been shown to be involved in ovule initiation. Here, we provide molecular and genetic evidence that points to DELLA proteins as novel players in the determination of ovule number in Arabidopsis and in species of agronomic interest, such as tomato and rapeseed, adding a new layer of complexity to this important developmental process. DELLA activity correlates positively with ovule number, acting as a positive factor for ovule initiation. In addition, ectopic expression of a dominant DELLA in the placenta is sufficient to increase ovule number. The role of DELLA proteins in ovule number does not appear to be related to auxin transport or signaling in the ovule primordia. Possible crosstalk between DELLA proteins and the molecular and hormonal network controlling ovule initiation is also discussed.

Hexacene generated on passivated silicon

On-surface synthesis represents a successful strategy to obtain designed molecular structures on an ultra-clean metal substrate. While metal surfaces are known to favor adsorption, diffusion, and chemical bonding between molecular groups, on-surface synthesis on non-metallic substrates would allow the electrical decoupling of the resulting molecule from the surface, favoring application to electronics and spintronics. Here, we demonstrate the on-surface generation of hexacene by surface-assisted reduction on a H-passivated Si(001) surface. The reaction, observed by scanning tunneling microscopy and spectroscopy, is probably driven by the formation of Si-O complexes at dangling bond defects. Supported by density functional theory calculations, we investigate the interaction of hexacene with the passivated silicon surface, and with single silicon dangling bonds.

Plasma and peritoneal fluid concentrations of ceftriaxone after intravenous and intraperitoneal administration in horses

Intraperitoneal (IP) use of antimicrobial agents may lead to therapeutic effects with better clinical results than intravenous (IV) administration. The aim of this study was to compare plasma and peritoneal fluid concentrations of ceftriaxone after IP and IV administration in horses, and to evaluate possible adverse effects. One group of five horses received 25mg/kg ceftriaxone diluted in 1L saline solution by IP catheter once daily for 5 days, while a second group of five horses received 25mg/kg ceftriaxone diluted in 250mL saline solution by IV injection once daily for 5days and 1L saline solution by IP catheter once daily for 5 days. Peritoneal fluid and plasma were collected to determine ceftriaxone concentrations after the first and fifth administration. IP administration of ceftriaxone resulted in concentrations above a minimum inhibitory concentration (MIC) of 1μg/mL for 24h in peritoneal fluid and for 12h in plasma, while IV administration of ceftriaxone resulted in lower peritoneal fluid concentrations, which remained above a MIC of 1μg/mL for 12h in peritoneal fluid and 10h in plasma. No adverse effects were observed. Comparisons of ceftriaxone concentrations, time of occurrence of the maximum (T_max) and minimum (T_min) concentrations, and the mean residence time (MRT), between the two groups showed that IP administration provided greater availability of cephalosporin in peritoneal fluid. The IP use of ceftriaxone (25mg/kg diluted in 1L saline solution once daily) may be useful for the prophylaxis and/or treatment of peritonitis in horses.

Genotypic and Environmental Effects on Tocopherol Content in Almond

Almond is the most important nut species worldwide and almond kernels show the highest levels of tocopherols among all nuts. In almond, tocopherols not only play a substantial role as a healthy food for human consumption, but also in protecting lipids against oxidation and, thus, lengthening the storage time of almond kernels. The main tocopherol homologues detected in almond in decreasing content and biological importance are α-, γ-, δ-, and β-tocopherol. Tocopherol concentration in almond depends on the genotype and the environment, such as the climatic conditions of the year and the growing management of the orchard. The range of variability for the different tocopherol homologues is of 335-657 mg/kg of almond oil for α-, 2-50 for γ-, and 0.1-22 for β-tocopherol. Drought and heat have been the most important stresses affecting tocopherol content in almond, with increased levels at higher temperatures and in water deficit conditions. The right cultivar and the most appropriate growing conditions may be selected to obtain crops with effective kernel storage and for the most beneficial effects of almond consumption for human nutrition and health.

Palladium-catalyzed cocyclotrimerization of arynes with a pyramidalized alkene

A pyramidalized alkene and diverse arynes are generated in the presence of a Pd-catalyst to afford [2+2+2] cocycloaddition products.

Decacene: On-Surface Generation

Acenes are intriguing molecules with unique electronic properties. The difficulties in their preparation owing to low stability under ambient conditions are apparent because successful syntheses of long unsubstituted acenes are still scarce, in spite of the great attention they have attracted. Only unsubstituted acenes up to heptacene have been isolated in bulk, with nonacene being the largest acene detected to date. Herein we use on-surface assisted reduction of tetraepoxy decacene precursors on Au(111) as the key step to generate unprecedented decacene which is visualized and its electronic resonances studied by scanning tunneling microscopy (STM) and spectroscopy (STS).

Corrigendum: Transcriptomic Analysis in Strawberry Fruits Reveals Active Auxin Biosynthesis and Signaling in the Ripe Receptacle

[This corrects the article on p. 889 in vol. 8, PMID: 28611805.].

Distribution of Aleutian mink disease virus contamination in the environment of infected mink farms

Control and eradication of Aleutian Mink Disease Virus (AMDV) are a major concern for fur-bearing animal production. Despite notably reducing disease prevalence, current control programs are unable to prevent the reinfection of farms, and environmental AMDV persistence seems to play a major role regarding this issue. In this study 114 samples from different areas and elements of seven infected mink farms were analyzed by qPCR in order to evaluate the environmental distribution of AMDV load. Samples were classified into nine categories, depending on the type of sample and degree of proximity to the animals, the main source of infection. Two different commercial DNA extraction kits were employed in parallel for all samples. qPCR analysis showed 69.3% positive samples with one kit and 81.6% with the other, and significant differences between the two DNA extraction methods were found regarding AMDV DNA recovery. Regarding sample categorization, all categories showed a high percentage of AMDV positive samples (31%-100%). Quantification of positive samples showed a decrease in AMDV load from animal barns to the periphery of the farm. In addition, those elements in direct contact with animals, the street clothes and vehicles of farm workers and personal protective equipment used for sampling showed a high viral load, and statistical analysis revealed significant differences in AMDV load between the first and last categories. These results indicate high environmental contamination of positive farms, which is helpful for future considerations about cleaning and disinfection procedures and biosecurity protocols.

Transcriptomic Analysis in Strawberry Fruits Reveals Active Auxin Biosynthesis and Signaling in the Ripe Receptacle

The role of auxin in ripening strawberry (Fragaria ×ananassa) fruits has been restricted to the early stages of development where the growth of the receptacle is dependent on the delivery of auxin from the achenes. At later stages, during enlargement of the receptacle, other hormones have been demonstrated to participate to different degrees, from the general involvement of gibberellins and abscisic acid to the more specific of ethylene. Here we report the involvement of auxin at the late stages of receptacle ripening. The auxin content of the receptacle remains constant during ripening. Analysis of the transcriptome of ripening strawberry fruit revealed the changing expression pattern of the genes of auxin synthesis, perception, signaling and transport along with achene and receptacle development from the green to red stage. Specific members of the corresponding gene families show active transcription in the ripe receptacle. For the synthesis of auxin, two genes encoding tryptophan aminotransferases, FaTAA1 and FaTAR2, were expressed in the red receptacle, with FaTAR2 expression peaking at this stage. Transient silencing of this gene in ripening receptacle was accompanied by a diminished responsiveness to auxin. The auxin activity in the ripening receptacle is supported by the DR5-directed expression of a GUS reporter gene in the ripening receptacle of DR5-GUS transgenic strawberry plants. Clustering by co-expression of members of the FaAux/IAA and FaARF families identified five members whose transcriptional activity was increased with the onset of receptacle ripening. Among these, FaAux/IAA11 and FaARF6a appeared, by their expression level and fold-change, as the most likely candidates for their involvement in the auxin activity in the ripening receptacle. The association of the corresponding ARF6 gene in Arabidopsis to cell elongation constitutes a suggestive hypothesis for FaARF6a involvement in the same cellular process in the growing and ripening receptacle.

Imaging the electronic structure of on-surface generated hexacene

Surface-assisted reduction of specially designed air-stable precursors allows us to study single hexacene molecules on Au(111) by scanning tunneling microscopy and spectroscopy, mapping with intramolecular resolution their extended electronic eigenstates.

Bence Jones proteinuria in smoldering multiple myeloma as a predictor marker of progression to symptomatic multiple myeloma

The diagnosis of smoldering multiple myeloma (SMM) includes patients with a heterogeneous risk of progression to active multiple myeloma (MM): some patients will never progress, whereas others will have a high risk of progression within the first 2 years. Therefore, it is important to improve risk assessment at diagnosis. We conducted a retrospective study in a large cohort of SMM patients, in order to investigate the role of Bence Jones (BJ) proteinuria at diagnosis in the progression to active MM. We found that SMM patients presenting with BJ proteinuria had a significantly shorter median time to progression (TTP) to MM compared with patients without BJ proteinuria (22 vs 88 months, respectively; hazard ratio=2.3, 95% confidence interval=1.4-3.9, P=0.002). We also identified risk subgroups based on the amount of BJ proteinuria: ⩾500 mg/24 h, <500 mg/24 h and without it, with a significantly different median TTP (13, 37 and 88 months, P<0.001). Thus, BJ proteinuria at diagnosis is an independent variable of progression to MM that identifies a subgroup of high-risk SMM patients (51% risk of progression at 2 years) and ⩾500 mg of BJ proteinuria may allow, if validated in another series, to reclassify these patients to MM requiring therapy before the end-organ damage development.

Tetracene Formation by On-Surface Reduction

We present the on-surface reduction of diepoxytetracenes to form genuine tetracene on Cu(111). The conversion is achieved by scanning tunneling microscopy (STM) tip-induced manipulation as well as thermal activation and is conclusively demonstrated by means of atomic force microscopy (AFM) with atomic resolution. We observe that the metallic surface plays an important role in the deoxygenation and for the planarization after bond cleavage.

Genome-Wide DNA Copy Number Analysis of Acute Lymphoblastic Leukemia Identifies New Genetic Markers Associated with Clinical Outcome

Identifying additional genetic alterations associated with poor prognosis in acute lymphoblastic leukemia (ALL) is still a challenge. Aims: To characterize the presence of additional DNA copy number alterations (CNAs) in children and adults with ALL by whole-genome oligonucleotide array (aCGH) analysis, and to identify their associations with clinical features and outcome. Array-CGH was carried out in 265 newly diagnosed ALLs (142 children and 123 adults). The NimbleGen CGH 12x135K array (Roche) was used to analyze genetic gains and losses. CNAs were analyzed with GISTIC and aCGHweb software. Clinical and biological variables were analyzed. Three of the patients showed chromothripsis (cth6, cth14q and cth15q). CNAs were associated with age, phenotype, genetic subtype and overall survival (OS). In the whole cohort of children, the losses on 14q32.33 (p = 0.019) and 15q13.2 (p = 0.04) were related to shorter OS. In the group of children without good- or poor-risk cytogenetics, the gain on 1p36.11 was a prognostic marker independently associated with shorter OS. In adults, the gains on 19q13.2 (p = 0.001) and Xp21.1 (p = 0.029), and the loss of 17p (p = 0.014) were independent markers of poor prognosis with respect to OS. In summary, CNAs are frequent in ALL and are associated with clinical parameters and survival. Genome-wide DNA copy number analysis allows the identification of genetic markers that predict clinical outcome, suggesting that detection of these genetic lesions will be useful in the management of patients newly diagnosed with ALL.

Experimental Evidence of the Origin of Nanophase Separation in Low Hole-Doped Colossal Magnetoresistant Manganites

While being key to understanding their intriguing physical properties, the origin of nanophase separation in manganites and other strongly correlated materials is still unclear. Here, experimental evidence is offered for the origin of the controverted phase separation mechanism in the representative La1-xCaxMnO3 system. For low hole densities, direct evidence of Mn(4+) holes localization around Ca(2+) ions is experimentally provided by means of aberration-corrected scanning transmission electron microscopy combined with electron energy loss spectroscopy. These localized holes give rise to the segregated nanoclusters, within which double exchange hopping between Mn(3+) and Mn(4+) remains restricted, accounting for the insulating character of perovskites with low hole density. This localization is explained in terms of a simple model in which Mn(4+) holes are bound to substitutional divalent Ca(2+) ions.

The rise of ampicillin-resistant Enterococcus faecium high-risk clones as a frequent intestinal colonizer in oncohaematological neutropenic patients on levofloxacin prophylaxis: a risk for bacteraemia?

Levofloxacin extended prophylaxis (LEP), recommended in oncohaematological neutropenic patients to reduce infections, might select resistant bacteria in the intestine acting as a source of endogenous infection. In a prospective observational study we evaluated intestinal emergence and persistence of ampicillin-resistant Enterococcus faecium (AREfm), a marker of hospital adapted high-risk clones. AREfm was recovered from the faeces of 52 patients with prolonged neutropenia after chemotherapy, at admission (Basal), during LEP, and twice weekly until discharge (Pos-LEP). Antibiotic susceptibility, virulence traits and population structure (pulsed-field gel electrophoresis and multilocus sequence typing) were determined and compared with bacteraemic isolates. Gut enterococcal population was monitored using a quantitative PCR quantification approach. AREfm colonized 61.4% of patients (194/482 faecal samples). Sequential AREfm acquisition (25% Basal, 36.5% LEP, 50% Pos-LEP) and high persistent colonization rates (76.9-89.5%) associated with a decrease in clonal diversity were demonstrated. Isolates were clustered into 24 PFGE-patterns within 13 sequence types, 95.8% of them belonging to hospital-associated Bayesian analysis of population structure subgroups 2.1a and 3.3a. Levofloxacin resistance and high-level streptomycin resistance were a common trait of these high-risk clones. AREfm-ST117, the most persistent clone, was dominant (60.0% isolates, 32.6% patients). It presented esp gene and caused 18.2% of all bacteraemia episodes in 21% of patients previously colonized by this clone. In AREfm-colonized patients, intestinal enrichment in the E. faecium population with a decline in total bacterial load was observed. AREfm intestinal colonization increases during hospital stay and coincides with enterococci population enrichment in the gut. Dominance and intestinal persistence of the ST117 clone might increase the risk of bacteraemia.

Consensus recommendations on training and competing in the heat

Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimise performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimise performance is to heat acclimatise. Heat acclimatisation should comprise repeated exercise-heat exposures over 1–2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimise dehydration during exercise. Following the development of commercial cooling systems (eg, cooling-vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organisers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimising the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events, for hydration and body cooling opportunities, when competitions are held in the heat.

On the prediction of Hodgkin lymphoma treatment response

PURPOSE

The cure rate in Hodgkin lymphoma is high, but the response along with treatment is still unpredictable and highly variable among patients. Detecting those patients who do not respond to treatment at early stages could bring improvements in their treatment. This research tries to identify the main biological prognostic variables currently gathered at diagnosis and design a simple machine learning methodology to help physicians improve the treatment response assessment.

METHODS

We carried out a retrospective analysis of the response to treatment of a cohort of 263 Caucasians who were diagnosed with Hodgkin lymphoma in Asturias (Spain). For that purpose, we used a list of 35 clinical and biological variables that are currently measured at diagnosis before any treatment begins. To establish the list of most discriminatory prognostic variables for treatment response, we designed a machine learning approach based on two different feature selection methods (Fisher's ratio and maximum percentile distance) and backwards recursive feature elimination using a nearest-neighbor classifier (k-NN). The weights of the k-NN classifier were optimized using different terms of the confusion matrix (true- and false-positive rates) to minimize risk in the decisions.

RESULTS AND CONCLUSIONS

We found that the optimum strategy to predict treatment response in Hodgkin lymphoma consists in solving two different binary classification problems, discriminating first if the patient is in progressive disease; if not, then discerning among complete and partial remission. Serum ferritin turned to be the most discriminatory variable in predicting treatment response, followed by alanine aminotransferase and alkaline phosphatase. The importance of these prognostic variables suggests a close relationship between inflammation, iron overload, liver damage and the extension of the disease.

Managing the health of the elite athlete: a new integrated performance health management and coaching model

Elite athletes endeavour to train and compete even when ill or injured. Their motivation may be intrinsic or due to coach and team pressures. The sports medicine physician plays an important role to risk-manage the health of the competing athlete in partnership with the coach and other members of the support team. The sports medicine physician needs to strike the right ethical and operational balance between health management and optimising performance. It is necessary to revisit the popular delivery model of sports medicine and science services to elite athletes based on the current reductionist multispecialist system lacking in practice an integrated approach and effective communication. Athlete and coach in isolation or with a member of the multidisciplinary support team, often not qualified or experienced to do so, decide on the utilisation of services and how to apply the recommendations. We propose a new Integrated Performance Health Management and Coaching model based on the UK Athletics experience in preparation for the London Olympic and Paralympic Games. The Medical and Coaching Teams are managed by qualified and experienced individuals operating in synergy towards a common performance goal, accountable to a Performance Director and ultimately to the Board of Directors. We describe the systems, processes and implementation strategies to assist the athlete, coach and support teams to continuously monitor and manage athlete health and performance. These systems facilitate a balanced approach to training and competing decisions, especially while the athlete is ill or injured. They take into account the best medical advice and athlete preference. This Integrated Performance Health Management and Coaching model underpinned the Track and Field Gold Medal performances at the London Olympic and Paralympic Games.

The Arabidopsis 14-3-3 protein RARE COLD INDUCIBLE 1A links low-temperature response and ethylene biosynthesis to regulate freezing tolerance and cold acclimation

In plants, the expression of 14-3-3 genes reacts to various adverse environmental conditions, including cold, high salt, and drought. Although these results suggest that 14-3-3 proteins have the potential to regulate plant responses to abiotic stresses, their role in such responses remains poorly understood. Previously, we showed that the RARE COLD INDUCIBLE 1A (RCI1A) gene encodes the 14-3-3 psi isoform. Here, we present genetic and molecular evidence implicating RCI1A in the response to low temperature. Our results demonstrate that RCI1A functions as a negative regulator of constitutive freezing tolerance and cold acclimation in Arabidopsis thaliana by controlling cold-induced gene expression. Interestingly, this control is partially performed through an ethylene (ET)-dependent pathway involving physical interaction with different ACC SYNTHASE (ACS) isoforms and a decreased ACS stability. We show that, consequently, RCI1A restrains ET biosynthesis, contributing to establish adequate levels of this hormone in Arabidopsis under both standard and low-temperature conditions. We further show that these levels are required to promote proper cold-induced gene expression and freezing tolerance before and after cold acclimation. All these data indicate that RCI1A connects the low-temperature response with ET biosynthesis to modulate constitutive freezing tolerance and cold acclimation in Arabidopsis.

Chemical analysis at atomic resolution of isolated extended defects in an oxygen-deficient, complex manganese perovskite

A general approach to the structural and analytical characterization of complex bulk oxides that exploits the advantage of the atomic spatial resolution and the analytical capability of aberration-corrected microscopy is described. The combined use of imaging and spectroscopic techniques becomes necessary to the complete characterization of the oxygen-deficient colossal magnetoresistant La(0.56)Sr(0.44)MnO(2.5)-related perovskite. In this compound, the formation of isolated (La/Sr)O and MnO rock-salt-type planar defects are identified from atomically resolved High Angle Annular Dark Field (HAADF) images. The location of the oxygen atomic columns from Annular Bright Field (ABF) images indicates edge-sharing MnO6 octahedra in the MnO planes and the study performed by Electron Energy Loss Spectroscopy (EELS) reveals different Mn oxidation states derived from the corner- or edge-sharing MnO6 octahedra environment.

A gold-catalysed imine–propargylamine cascade sequence: synthesis of 3-substituted-2,5-dimethylpyrazines and the reaction mechanism

The gold-catalysed coupling reaction between propargylamine-derived imines and propargylamine exclusively afforded pyrazines.