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In this paper, we investigate a critical behavior of JT gravity, a model of two-dimensional quantum gravity on constant negatively curved spacetimes. Our approach involves using techniques from random maps to investigate the generating function of Weil-Petersson volumes, which count random hyperbolic surfaces with defects. The defects are weighted geodesic boundaries, and criticality is reached by tuning the weights to the regime where macroscopic holes emerge in the hyperbolic surface, namely non-generic criticality. We analyze the impact of this critical regime on some universal features, such as its density of states. We present a family of models that interpolates between systems with ρ0(E) ~ E − E 0 and ρ0(E) ~ (E − E0)3/2, which are commonly found in models of JT gravity coupled to dynamical end-of-the-world and FZZT branes, and give a precise definition of what this phase transition means from the random geometry point of view. [ABSTRACT FROM AUTHOR]

Mango can be grown in subtropical and semi-arid regions, where using commercial cultivars and rootstocks with improved resistance to drought is crucial. Induction of polyploidy has been widely applied in breeding programs for increasing crop drought resistance. In this study, drought resistance of several mango cultivars and their respective autotetraploids was evaluated. Leaf morphology and physiology were monitored in two-year-old plants during a period of water withholding and subsequent rewatering. Even though all tetraploid cultivars presented morphological differences in leaf traits, the effect of ploidy in delaying leaf water loss and its detrimental effects of photosynthesis was only observed in 'Gomera-1'. As a result of this, this cultivar sustained maximum levels of quantum efficiency and gas exchange for a longer period than the rest of cultivars. Therefore, the isohydric strategy of this tetraploid was not associated with earlier stomatal closure. Proline did not increase in the isohydric cultivar probably due to the maintenance of high leaf relative water content. In contrast, in some anisohydric mangos, proline increased when leaf water content decreased below 80%. Some diploids exhibited higher levels of proline than tetraploids, but recovery of plant functionality after rewatering did not differ from the rest of cultivars. We conclude that drought resistance in mango can be improved by using polyploids with water-saving physiological traits. [ABSTRACT FROM AUTHOR]

Bryophytes are the group of land plants with the lowest photosynthetic rates, which was considered to be a consequence of their higher anatomical CO2 diffusional limitation compared with tracheophytes. However, the most recent studies assessing limitations due to biochemistry and mesophyll conductance in bryophytes reveal discrepancies based on the methodology used. In this study, we compared data calculated from two different methodologies for estimating mesophyll conductance: variable J and the curve-fitting method. Although correlated, mesophyll conductance estimated by the curve-fitting method was on average 4-fold higher than the conductance obtained by the variable J method; a large enough difference to account for the scale of differences previously shown between the biochemical and diffusional limitations to photosynthesis. Biochemical limitations were predominant when the curve-fitting method was used. We also demonstrated that variations in bryophyte relative water content during measurements can also introduce errors in the estimation of mesophyll conductance, especially for samples which are overly desiccated. Furthermore, total chlorophyll concentration and soluble proteins were significantly lower in bryophytes than in tracheophytes, and the percentage of proteins quantified as Rubisco was also significantly lower in bryophytes (<6.3% in all studied species) than in angiosperms (>16% in all non-stressed cases). Photosynthetic rates normalized by Rubisco were not significantly different between bryophytes and angiosperms. Our data suggest that the biochemical limitation to photosynthesis in bryophytes is more relevant than so far assumed. [ABSTRACT FROM AUTHOR]

The data available so far indicate that the photosynthetic and relative growth rates of bryophytes are 10% of those reported for tracheophytes. By examining the existing literature and reanalysing data published in over 100 studies, this review examines the ecophysiological, biochemical, and structural reasons behind this phenomenon. The limiting Rubisco content and surface for gas exchange are the internal factors that can explain the low photosynthetic and growth rates of bryophytes. The role of the thicker cell walls of bryophytes in limiting CO2 diffusion is unclear, due to the current uncertainties regarding their porosity and permeability to CO2. From this review, it is also evident that, despite bryophytes having low photosynthetic rates, their positive carbon balance is tightly related to their capacity to deal with extreme conditions. Contributing factors include their capacity to deal with large daily temperature oscillations, and their capacity to delay the cessation of photosynthesis under water deficit (or to tolerate desiccation in extreme situations). Although further studies on bryophytes are needed before more solid conclusions can be drawn, it seems that their success relies on their remarkable tolerance to a highly variable environment, possibly at the expense of their maximum photosynthetic rate. [ABSTRACT FROM AUTHOR]

Mosses have been found outliers of the trade‐off between photosynthesis and bulk elastic modulus described for vascular plants. Hence, potential trade‐offs among physical features of cell walls and desiccation tolerance, water relations, and photosynthesis were assessed in bryophytes and other poikilohydric species. Long‐term desiccation tolerance was quantified after variable periods of desiccation/rehydration cycles. Water relations were analyzed by pressure–volume curves. Mesophyll conductance was estimated using both CO2 curve‐fitting and anatomical methods. Cell wall elasticity was the parameter that better correlated with the desiccation tolerance index for desiccation tolerant species and was antagonistic to higher absolute values of osmotic potential. Although high values of cell wall effective porosity were estimated compared with the values assumed for vascular plants, the desiccation tolerance index negatively correlated with the porosity in desiccation tolerant bryophytes. Neither cell wall thickness nor photosynthetic capacity were correlated with the desiccation tolerance index of the studied species. The existence of a potential evolutionary trade‐off between cell wall thickness and desiccation tolerance is rejected. The photosynthetic capacity reported for bryophytes is independent of elasticity and desiccation tolerance. Furthermore, the role of cell wall thickness in limiting CO2 conductance would be overestimated under a scenario of high cell wall porosity for most bryophytes. [ABSTRACT FROM AUTHOR]

Drug hypersensitivity reactions (DHRs) to platinum-based compounds (PCs) are on the rise, and their personalized and safe management is essential to enable first-line treatment for these cancer patients. This study aimed to evaluate the usefulness of the basophil activation test by flow cytometry (BAT-FC) and the newly developed sIgE-microarray and BAT-microarray in diagnosing IgE-mediated hypersensitivity reactions to PCs. A total of 24 patients with DHRs to PCs (20 oxaliplatin and four carboplatin) were evaluated: thirteen patients were diagnosed as allergic with positive skin tests (STs) or drug provocation tests (DPTs), six patients were diagnosed as non-allergic with negative STs and DPTs, and five patients were classified as suspected allergic because DPTs could not be performed. In addition, four carboplatin-tolerant patients were included as controls. The BAT-FC was positive in 2 of 13 allergic patients, with a sensitivity of 15.4% and specificity of 100%. However, the sIgE- and BAT-microarray were positive in 11 of 13 DHR patients, giving a sensitivity of over 84.6% and a specificity of 90%. Except for one patient, all samples from the non-allergic and control groups were negative for sIgE- and BAT-microarray. Our experience indicated that the sIgE- and BAT-microarray could be helpful in the endophenotyping of IgE-mediated hypersensitivity reactions to PCs and may provide an advance in decision making for drug provocation testing. [ABSTRACT FROM AUTHOR]

Resurrection plants are vascular species able to sustain extreme desiccation in their vegetative tissues. Despite its potential interest, the role of leaf anatomy in CO2 diffusion and photosynthesis under non-stressed conditions has not been explored in these species. Net CO2 assimilation (A n) and its underlying diffusive, biochemical, and anatomical determinants were assessed in 10 resurrection species from diverse locations, including ferns, and homoiochlorophyllous and poikilochlorophyllous angiosperms. Data obtained were compared with previously published results in desiccation-sensitive ferns and angiosperms. A n in resurrection plants was mostly driven by mesophyll conductance to CO2 (g m) and limited by CO2 diffusion. Resurrection species had a greater cell wall thickness (T cw) than desiccation-sensitive plants, a feature associated with limited CO2 diffusion in the mesophyll, but also greater chloroplast exposure to intercellular spaces (S c), which usually leads to higher g m. This combination enabled a higher A n per T cw compared with desiccation-sensitive species. Resurrection species possess unusual anatomical features that could confer stress tolerance (thick cell walls) without compromising the photosynthetic capacity (high chloroplast exposure). This mechanism is particularly successful in resurrection ferns, which display higher photosynthesis than their desiccation-sensitive counterparts. [ABSTRACT FROM AUTHOR]

A promising approach for obtaining a large magnetoelectric response at room temperature in single-phase materials is to make use of phase-change phenomena at structural instabilities of a multiferroic state. This is the case of perovskites showing the morphotropic phase boundary (MPB) between ferroelectric polymorphs with differentiated magnetic orderings, like in BiFeO3–PbTiO3. Indeed, distinctive magnetoelectric effects were recently shown in Mn-modified BiFeO3–PbTiO3, associated with the electric field-induced phase transition between the coexisting MPB phases. We report here analogous effects under the magnetic field in 0.7BiFeO3–0.3PbTiO3, which shed light on the reversibility of the phase-change phenomena and the role of the magnetic ordering in the phase coexistence at the structural instability characteristic of the MPB. Results demonstrate magnetic field-driven phase-change phenomena. [ABSTRACT FROM AUTHOR]

"Serrano" pepper is extensively used in Mexican cuisine. The aim of this study was to identify the bioaccessible phenolic compounds (PC) of "Serrano" pepper as well as short-chain fatty acids (SCFA) produced and PC bioconverted using an in vitro step-wise gastromimetic model of the intestinal digestion and anaerobic fermentation of the isolated indigestible fraction (IF). The anti-topoisomerase activity of the fermented samples was also evaluated. PC bioaccessibility was about 45% in the small intestine. Chlorogenic acid and capsaicin were identified during the intestinal digestion, while quercetin was identified as available to the gut microbiota. After 48-h fermentation, SCFA molar ratio was 77:11:12 for acetic, propionic and butyric acid. The PC identified in IF and after 12 h of fermentation showed anti-topoisomerase activity. A synergistic effect among the PC and gut metabolites mixture was observed, which indicates a possible antiproliferative mechanism that should be tested in further studies. [ABSTRACT FROM AUTHOR]

In vascular plants, more rigid leaves have been linked to lower photosynthetic capacity, associated with low CO2 diffusion across the mesophyll, indirectly resulting in a trade-off between photosynthetic capacity (A n) and bulk modulus of elasticity (ε). However, we evaluated mosses, liverworts, and Chara sp. plus some lycophytes and ferns, and found that they behaved as clear outliers of the A n–ε relationship. Despite this finding, when vascular and non-vascular plants were plotted together, ε still linearly determined the cessation of net photosynthesis during desiccation both in species with stomata (either actively or hydro-passively regulated) and in species lacking stomata, and regardless of their leaf structure. The latter result challenges our current view of photosynthetic responses to desiccation and/or water stress. Structural features and hydric strategy are discussed as possible explanations for the deviation of these species from the A n–ε trade-off, as well as for the general linear dependency between ε and the full cessation of A n during desiccation. [ABSTRACT FROM AUTHOR]

The perovskite (1−x)YMnO3−xBiFeO3 binary system is very promising because of its multiferroic end members. Nanocrystalline phases have been recently obtained by mechanosynthesis across the system, and the perovskite structural evolution has been described. Two continuous solid solutions with orthorhombic Pnma and rhombohedral R3c symmetries were found, which coexist within a broad compositional interval of 0.5 ≤ x ≤ 0.9. This might be a polar‐nonpolar morphotropic phase boundary region, at which strong phase‐change magnetoelectric responses can be expected. A major issue is phase decomposition at moderate temperatures that highly complicates ceramic processing. This is required for carrying out a sound electrical characterization and also for their use in devices. We present here the application of Spark Plasma Sintering to the ceramic processing of YMnO3‐BiFeO3 phases. This advanced technique, when combined with nanocrystalline powders, allowed densifying phases at reduced processing temperatures and times, so that perovskite decomposition was avoided. Electrical measurements were accomplished, and the response was shown to be mostly dominated by conduction. Nonetheless, the intrinsic dielectric permittivity was obtained, and a distinctive enhancement in the phase coexistence region was revealed. Besides, Rayleigh‐type behavior characteristic of ferroelectrics was also demonstrated for all rhombohedral phases. Magnetic characterization was performed in this region, and antiferromagnetism was shown. [ABSTRACT FROM AUTHOR]

Abstract A Mexican staple food prepared with corn "tortilla" (Zea mays L.) and common beans (Phaseolus vulgaris L.) is named as "taco". It was fermented in an in vitro colonic Simulator of Human Microbial Ecosystem (SHIME®) to evaluate the effect in short chain fatty acids (SCFA), ammonia production, and the growth of total presumptive counts for anaerobic bacteria, Lactobacillus spp., Bifidobacterium spp., Clostridium spp., and total coliforms in the three simulated reactors of the human colon. After two weeks of stabilization, the simulator was fed during 9 days with the mixture of 50 g of beans and 50 g of tortilla mixed with 100 mL of carbohydrate based medium. Every third day, samples were collected from the three simulated colon vessels for the corresponding analysis. The production of the SCFA was higher during the treatment period than the basal period in the three colon sections. The acetate was produced in higher concentration (191.9 mmol/L) than propionate and butyrate (29.1 and 55.0 mmol). During the treatment period, the higher molar ratio (%) for acetate, propionate, and butyrate were 84: 14: 24, respectively. The ammonia ions as well as the growth of presumptive coliforms were reduced (p < 0.05) in the three simulated colon vessels during the treatment. Finally, in vitro fermentation of Mexican "taco" showed a possible potential functional profile of an ancestral staple food due to the production of SCFA that may exert beneficial effects. Graphical abstract Unlabelled Image Highlights • Corn tortilla and common beans known as "taco" was evaluated in a SHIME® system. • The SCFAs production was higher during treatment period than basal period. • Molar ratio for acetic, propionic, and butyric was 55.04: 13.30: 31.65 respectively. • Ammonia ions were reduced 91% during treatment • Mexican "taco" showed a potential functional profile of an ancestral staple food. [ABSTRACT FROM AUTHOR]

The indigestible fraction (IF) isolated from three lunch menus: Modified Mexican Lunch (MM-L), Traditional Mexican Lunch (TM-L) and Alternative Mexican Lunch (AM-L), was studied in terms of antioxidant capacity (AOX) and metabolites produced through fermentation by human intestinal microbiota. IFs were isolated after withstanding in vitro gastrointestinal digestion and total soluble polyphenols (TSP), condensed tannins (CT), hydrolysable polyphenols (HP) and AOX (DPPH, FRAP) were evaluated. AOX, pH and bacterial metabolites profile changes were also monitored during in vitro colonic fermentation. Lunch menus showed differences in IF, TSP, CT and FRAP values (p<.05). TM-L had the highest TSP and CT contents (0.84 and 1.89 g/100 g DW, respectively). Changes in pH and AOX during fermentation were time-dependent and substrate-dependent (p<.05). Butyric acid production was not significantly modified by the IFs (p>.05). Fifty-seven microbiota-produced volatile compounds were detected by SPME-GC-MS. This study shows the potential effects of food habits on bacterial metabolite production. [ABSTRACT FROM AUTHOR]

Abstract: The ferromagnetic perovskite oxide BiMnO3 is a highly topical material, and the solid solutions it forms with antiferromagnetic/ferroelectric BiFeO3 and with ferroelectric PbTiO3 result in distinctive polar/nonpolar morphotropic phase boundaries (MPBs). The exploitation of such a type of MPBs could be a novel approach to engineer novel multiferroics with phase‐change magnetoelectric responses, in addition to ferroelectrics with enhanced electromechanical performance. Here, the interplay among crystal structure, point defects, and multiferroic properties of the BiMnO3–BiFeO3–PbTiO3 ternary system at its line of MPBs between polymorphs of tetragonal P4mm (polar) and orthorhombic Pnma (antipolar) symmetries is reported. A strong dependence of the phase coexistence on thermal history is found: phase percentage significantly changes whether the material is quenched or slowly cooled from high temperature. The origin of this phenomenon is investigated with temperature‐dependent structural and physical property characterizations. A major role of the complex defect chemistry, where a Bi/Pb‐deficiency allows Mn and Fe ions to have a mixed‐valence state, in the delicate balance between polymorphs is proposed, and its influence in the magnetic and electric ferroic orders is defined. [ABSTRACT FROM AUTHOR]

Light is one of the major stress factors that alpine plants face. Phenotypic plasticity of photoprotection mechanisms was analyzed in six alpine species growing in the Teide National Park (Canary Islands, Spain) at two different light exposures: full sunlight and 50% shading. Measurements of absorptance and chlorophyll fluorescence parameters obtained from induction kinetics and rapid light curves were performed. The studied species displayed high modulation capacity in most of the analyzed physiological traits, such as avoidance of light absorption, partitioning of the absorbed energy into consumption and/or dissipation, and its resultant resistance to high light, although in some cases opposite directions were observed. Three different response patterns were reported: 1) high adaptive plasticity response to light exposure, such as in Spartocytisus supranubius and Scrophularia glabrata , which could develop a high non-photochemical quenching or face higher levels of saturating irradiation at full sunlight exposure, 2) high modulation response in a non-adaptive direction, as found in Adenocarpus viscosus, which decreased its non-photochemical quenching at high irradiation, and in Pterocephalus lasiospermus , which increased photodamage of PSII and started decreasing ETR at low PPFD when developing at high light exposition, and 3) low physiological plasticity, as in Echium wildpretii , which could only modulate its leaf absorptance. Our data suggest that phenotypic plasticity should not always be considered as an adaptive response in nature. [ABSTRACT FROM AUTHOR]

[Display omitted] • In vitro Psidium species bioaccesibility of phenolic compounds (PC) were 37 to 47% • Psidium friedrichsthalianum Nied. showed the highest PC content. • 57 bioactive compounds were identified: PC, terpenoids and benzophenones. • Caffeoylquinic acid, ellagic acid & myricetin-3-O-rhamnoside were bioaccessible. • Prodelphinidin B2 isomer, galloyl-hexoside and cafeoylquimic acid were non-bioaccessible. Psidium guajava L. and Psidium friedrichsthalianum Nied are part of the Psidium species native to America. Nowadays, it is essential to study the phenolic compound (PC) profile and their changes during digestion and the fractions available for absorption. This study aimed to characterize the PC profile in some Psidium species and their bioaccessibility (BA). Fifty-seven compounds were identified, and forty-six belonged to ten different phenolic classes. PC profiles showed significant differences between the species and the intestinal fraction P. friedrichsthalianum Nied. showed the highest PC content, although it mostly belonged to non-extractable polyphenols. This leads to the lowest BA (37%); P. guajava L. 'Morada' showed the highest (47%). Hydroxycinnamic acids were the most stable PC after gastrointestinal digestion. This study showed relevant differences in the PC content and profile of different Psidium species and changes between the PC in the original matrix and those released in the different stages of gastrointestinal digestion. [ABSTRACT FROM AUTHOR]

The introduction of HAART resulted in the decrease of Leishmania /HIV co-infection cases; nevertheless, the number of relapses remains high and secondary prophylaxis is recommended. However, secondary prophylaxis is not necessary in all patients, and presents a high risk of toxicity and an elevated cost. Our aim was to study whether specific cellular response to Leishmania infantum (measured by cell proliferation response after stimulation with soluble Leishmania antigen (SLA)), could be a useful tool to attempt a secondary prophylaxis withdrawal. In June 2009 an outbreak of leishmaniasis by Leishmania infantum was declared in the southeast of Madrid, and since January 2013, we recruited 10 HIV+ patients that had been treated for visceral leishmaniasis. 6 patients had positive SLA-cell proliferation test. The mean CD4 cell counts of those patients with positive SLA were 140 cel/mm3 and 40 cel/mm3 in those with negative SLA test. 3 patients with positive SLA-cell proliferation test (CD4 count: 336, 307, 625) were not on prophylaxis, and the other 3 patients (CD4 count: 152, 189, 359) were on secondary prophylaxis that was withdrawn after the positive SLA-cell proliferation test with no posterior relapses (mean follow up 60 weeks). From the 4 patients, which had negative SLA-cell proliferation test and continued on prophylaxis, 3 had positive PCR for Leishmania at the end of the follow-up and 2 presented clinical relapses. The performance of SLA-cell proliferation test can be a useful tool that can permit us to try withdrawal of the prophylaxis in Leishmania /HIV co-infected patients with low CD4 + counts under clinical supervision, diminishing risk of toxicity and cost. [ABSTRACT FROM AUTHOR]

In recent years, attempts have been made in linking pressure–volume parameters and the leaf economics spectrum to expand our knowledge of the interrelationships among leaf traits. We provide theoretical and empirical evidence for the coordination of the turgor loss point and associated traits with net CO2 assimilation (An) and leaf mass per area (LMA). We measured gas exchange, pressure–volume curves and leaf structure in 45 ferns and angiosperms, and explored the anatomical and chemical basis of the key traits. We propose that the coordination observed between mass‐based An, capacitance and the turgor loss point (πtlp) emerges from their shared link with leaf density (one of the components of LMA) and, specially, leaf saturated water content (LSWC), which in turn relates to cell size and nitrogen and carbon content. Thus, considering the components of LMA and LSWC in ecophysiological studies can provide a broader perspective on leaf structure and function. [ABSTRACT FROM AUTHOR]

Abstract: Multiferroic materials showing magnetoelectric coupling are required in various technological applications. Many synthetical approaches can be used to improve the magnetic and/or electrical properties, in particular when the materials exhibit cationic valence fluctuations, as in the Co2MnO4 cubic spinel. In this compound, Co and Mn ions are in competition at the tetrahedral and octahedral positions, depending on their various oxidation states. The Co2MnO4 was prepared following two techniques: by a soft chemical route based on a modified polymer precursor method, and by a mechanoactivation route. Both approaches yield polycrystalline powders, but their crystallites sizes and particles morphologies differ as a function of the calcination conditions. The magnetic characterization (ZFC/FC cycles, ordering temperatures, ferromagnetic coercive fields and saturation magnetizations) showed that the synthesis procedure influenced the physical properties of Co2MnO4 mainly through the size of the magnetic domains, which play an important role on the magnetic interactions between the Co/Mn cations. [Copyright &y& Elsevier]

[Display omitted] • Vanillic acid was the most bioaccessible compound in tomato and husk tomato. • 3-Hydroxyphenylacetic acid was the major metabolite found after 48 h fermentation. • Volatile organic compounds could be a relevant indicator of colon health promotion. • Volatile-terpenes and derivatives suggested the metabolism of carotenoids. Two of the most important Mexican plant-foods are tomato (Solanum lycopersicum L.) and husk tomato (Physalis ixocarpa Brot.). In this study three objectives were followed: i) to evaluate the bioaccessible phenolic compounds (PC) in T and HT during upper gastrointestinal digestion, ii) to in vitro ferment the indigestible fractions of the samples to evaluate the short-chain fatty acids (SCFA) production, iii) the microbial metabolites, bioconverted PC and volatile organic compounds (VOCs) generated during the fermentation. Vanillic acid was the most bioaccessible PC and after 48 h, 3-hydroxyphenylacetic acid was the most abundant microbial metabolite identified in both samples. The identification of VOCs belonging to terpenes (and derivatives) group in T and HT can be product of the microbial metabolism of carotenoids. The study shows new knowledge of the in vitro intestinal digestion and fermentation of T and HT final compounds with biological potential which should be evaluated in further studies. [ABSTRACT FROM AUTHOR]

Abstract: Geological studies are fundamental to archaeologists as they provide essential data to understand certain processes involved in the present archaeological record. When working on marine coastal archaeology, the information provided by geomorphologic studies with regards to the evolution and dynamics of coastal marine lines is essential to assess the availability and accessibility of certain marine coastal areas, and their resources, to human populations of the past. This is also the key to reach correct cultural interpretations. However, on certain occasions, archaeological information can also offer valuable alternative data for geologists to reach geological interpretations, for instance when working on the evolution and changes of coastal sea lines. In this case, spatial and temporal scales must be regarded. This idea is supported on the experience gained through research done on the Patagonian Atlantic coast at the two archaeological localities introduced in this paper: Cabo Blanco, where we evaluate models of evolution of the coastline with a number of radiocarbon dates from excavated sites; and Punta Medanosa, where we discuss the temporal depth of the formation of the coastal ridges for the mid-Holocene transgression. [Copyright &y& Elsevier]

Nanostructured ceramics with La1− xSr xGa1− yMg yO3−δ composition have been processed by spark plasma sintering of precursors obtained by mechanosynthesis. The compositions with x=0.10 and y=0.20 are single-phase ceramics even at the lowest processing temperatures of 900°C. For x=0.20, y=0.17, typical secondary phases as SrLaGaO4 and SrLaGa3O7 appear at all the processing temperatures, from 900° to 1100°C. The high reactivity of the precursors due to the prolonged milling allows highly densified ceramics (>98%) to be obtained at moderate applied pressures (100 MPa), and at temperatures for which the nanostructure scale is maintained. Single-phase ceramics present higher conductivity than those with isolating secondary phases. The nanostructure appears to break the vacancies ordering, and the conductivity is produced through random vacancies paths, diminishing the activation energy and increasing the total conductivity of the ceramics. [ABSTRACT FROM AUTHOR]

Substitution of arsenic for antimony in the Sb2MoO6 and Sb2Mo10O31 catalysts was undertaken. Taking as starting point the composition of biehlite Sb1.79As0.21MoO6, different nominal Sb2-xAsxMoO6 (0⩽x⩽1) compositions were studied. All attempts led to mixtures of orange (Sb2MoO6) and black ((Sb,As)2Mo10O31) crystals, indicating that arsenic can only substitute for antimony in the Sb2Mo10O31 framework. The crystal structure of Sb1.82As0.18Mo10O31 was determined by single-crystal X-ray diffraction technique to be isostructural with undoped orthorhombic Sb2Mo10O31 (CCD data, R=0.0394 for 2657 observed reflections). The structure consists of a three-dimensional framework of corner-sharing MoO6 octahedra, with channels accommodating Sb&z.sbnd;O&z.sbnd;(Sb,As)4+ groups which firmly hold together by edge-sharing pairs of MO6 octahedra belonging to columns parallel to b axis. The lone pairs of electrons of each pnictogen atom face each other inside the tunnels, at a distance similar to that of an oxygen–oxygen contact. The magnetic and the electric properties correspond to a mixed valence compound. [Copyright &y& Elsevier]

• Innovative study in TIM-2 system in Mexican sauces and polyphenols was carried out. • Flavonoids were the most abundant group both in original and digested sauces. • Hydroxycinnamic acids and flavonoids comprise 95% gut substrate for fermentation. • 4-hydroxyphenylacetic acid was the major metabolite generated by gut microbiota. • Nonivamide was the gut metabolite from capsaicin bioconversion. Husk tomato (Physalis ixocarpa Brot. ex. Horm) is mainly used in the preparation of many Mexican sauces due to its unique and slightly acidic flavor, both in raw and cooked forms. These sauces also usually contain Serrano hot pepper (Capsicum annuum L), onion (Allium cepa L.), garlic (Allium sativum L.), coriander (Coriandrum sativum L.) and salt. Mexican sauces are a pre-Hispanic staple food, yet there is scarce knowledge on the phenolic compounds (PC) that reach the colon bound to the indigestible fraction (IF) after intestinal digestion. Thus, the aim of the present work was to evaluate the indigestible fraction of two types of Mexican sauces made with cooked and raw husk tomato: cooked green sauce (CGS) and raw green sauce (RGS). IF of CGS and RGS were fermented in the in vitro model of the human colon (TIM-2) to investigate the PC bioconversion by the gut microbiota after 24, 48 and 72 h. PC of the original sauces and their predigested fractions, as well as the formed metabolites were identified and monitored by HPLC-ESI-QToF-MS. Cooking husk tomato significantly increased the total indigestible fraction (TIF), mainly due to its insoluble indigestible fraction (IIF), and diminished PC. Flavonoids (flavonols and flavones) were the most abundant phenolic group in digested sauces followed by capsaicinoids (a characteristic group derived from hot pepper), hydroxycinnamic acids, and hydroxybenzoic acids. The metabolites 3-(ρ-hydroxyphenyl) propionic acid, 3-(3-hydroxyphenyl) propionic acid and 4-hydroxyphenylacetic acid were the most abundant colonic metabolites identified, which are thought to be derived from the biotransformation of flavonoids and hydroxycinnamates. These results are the first obtained on in vitro colonic fermentation of Mexican sauces and should be considered in future studies on the health effects related to consuming this staple food. [ABSTRACT FROM AUTHOR]

Background: An outbreak of leishmaniasis caused by Leishmania infantum was declared in the southwest of the Madrid region (Spain) in June 2009. This provided a unique opportunity to compare the management of visceral leishmaniasis (VL) in immunocompetent adults (IC-VL), patients with HIV (HIV-VL) and patients receiving immunosuppressants (IS-VL). Methods: A cohort of adults with VL, all admitted to the Hospital Universitario de Fuenlabrada between June 2009 and June 2018, were monitored in this observational study, recording their personal, epidemiological, analytical, diagnostic, treatment and outcome variables. Results: The study population was made up of 111 patients with VL (10% HIV-VL, 14% IS-VL, 76% IC-VL). Seventy-one percent of the patients were male; the mean age was 45 years (55 years for the IS-VL patients, P = 0.017). Fifty-four percent of the IC-VL patients were of sub-Saharan origin (P = 0.001). Fever was experienced by 98% of the IC-VL patients vs 73% of the LV-HIV patients (P = 0.003). Plasma ferritin was > 1000 ng/ml in 77% of the IC-VL patients vs 17% of the LV-HIV patients (P = 0.007). Forty-two percent of patients fulfilled the criteria for haemophagocytic lymphohistiocytosis. RDT (rK39-ICT) serological analysis returned sensitivity and specificity values of 45% and 99%, respectively, and ELISA/iIFAT returned 96% and 89%, respectively, with no differences in this respect between patient groups. Fourteen (13.0%) patients with VL experienced treatment failure, eight of whom were in the IC-VL group. Treatment with < 21 mg/kg (total) liposomal amphotericin B (LAB) was associated with treatment failure in the IC-VL patients [P = 0.002 (OR: 14.7; 95% CI: 2.6–83.3)]. Conclusions: IS-VL was more common than HIV-VL; the lack of experience in dealing with IS-VL is a challenge that needs to be met. The clinical features of the patients in all groups were similar, although the HIV-VL patients experienced less fever and had lower plasma ferritin concentrations. RDT (rK39-ICT) analysis returned a good specificity value but a much poorer sensitivity value than reported in other scenarios. The patients with HIV-VL, IS-VL and IC-VL returned similar serological results. Current guidelines for treatment seem appropriate, but the doses of LAB required to treat patients with HIV-VL and IS-VL are poorly defined. [ABSTRACT FROM AUTHOR]

Intracellular magnesium contributes in the regulation of the effects of insulin and glucose uptake; its deficits strongly associated with hyperglycemia, hypertriglyceridemia and insulin resistance (IR). Studies in healthy, hypertensive, and diabetes mellitus type 2 (DM2) subjects have shown a lower concentration of intracellular magnesium, higher glucose increase. It is unknown if there is hypomagnesemia related to hyperglycemia and insulin resistance during pregnancy. Analytical cross-sectional study in pregnant women who signed consent, ≥18 years old, any trimester of pregnancy. Patients with chronic diarrhea, alcohol intake (≥30 g/day), use of diuretics and/or calcium channel blockers, reduced renal function, or supplemented with magnesium for at least six months prior to the study were not included. Clinical variables were determined, anthropometry, vital signs, serum magnesium levels, fasting glucose and 2-h plasma glucose (2-h PG) value during a 75-g oral glucose tolerance test (OGTT), lipid profile and glycosylated hemoglobin (A1C) were measured. We analyzed 84 patients with whom the 3 study groups were formed: healthy pregnant women, with IR (TyG index) and gestational diabetes (GD) (Table). Hypomagnesemia was found in all 3 groups without a clear relationship between low magnesium levels and alterations in glucose status. Disclosure: A. López Castro: None. A. Zavalza Gomez: None. S. Hernandez Gonzalez: None. M.C. Espinel-Bermudez: None. J.R. Ortiz Hernandez: None. [ABSTRACT FROM AUTHOR]

Due to environmental concerns, extensive research has been carried out to develop high-performance lead-free piezoceramics capable of replacing commercial lead-based materials. The lead-free (Ba 0.7 Ca 0.3)TiO 3 −Ba(Zr 0.2 Ti 0.8)O 3 system has emerged as a candidate for room temperature transducer applications because a high piezoelectric charge coefficient is achieved in this system for compositions at the morphotropic phase boundary. However, conventional ceramic processing of these eco-friendly piezoceramics demands high energy consumption because long-lasting, high-temperature heat treatments are needed, which often lead to microstructural degradation that compromises the material reliability. Field-assisted flash sintering has started to be explored since the application of an adequate electric field was shown to significantly reduce the sintering time and temperature, thereby controlling grain growth. In this work, Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 ceramics are obtained by current-controlled flash sintering of mechanosynthesized nanopowders. Exhaustive control of the sintering parameters allows tailoring of the microstructure, which allows dense fine-grained flash-sintered ceramics exhibiting a high electric field-induced strain response to be obtained. [ABSTRACT FROM AUTHOR]

Antarctic macroalgal communities of the upper intertidal zone are particularly poor compared with other coastal regions. Exposure to desiccation and freezing combined with the abrasive effect of ice threatens the life of sessile organisms. One of the few species able to colonize this environment is the rhodophyte Pyropia endiviifolia. It belongs to the Bangiales, one of the oldest extant clades of photosynthetic eukaryotes, which has occurred for more than one billion years with basically the same morphological structure. Considering that the extent of Antarctic glaciation is a geologically recent event, we hypothesized that pre-adaptations to desiccation in bangiophytes may have contributed to the success of P. endiviifolia in Antarctica. To test this, we compared its photosynthetic performance and tolerance to desiccation and freezing with those from a related intertidal species, the temperate Atlantic species Porphyra linearis. As evidenced by gas exchange and chlorophyll fluorescence, P. endiviifolia is more adapted to high irradiances than P. linearis. The former species was also more desiccation-tolerant, and showed a higher glass transition temperature. Both species did not differ in chlorophyll content per dry weight, and tolerance to −20°C, even though the ice-nucleation temperature was much higher in P. endiviifolia. Membrane integrity may depend on fatty acid composition in P. endiviifolia, while on enhanced tocopherol in P. linearis. Overall, both species show different strategies to deal with freezing temperatures: supercooling in P. linearis vs. freezing-tolerance in P. endiviifolia. This matches with the probability of being subjected to sub-zero temperatures in their natural environments (lower in the case of P. linearis). Surprisingly, the higher risk of dehydration in the natural habitat of P. linearis is not matched by a higher desiccation tolerance. This observation does not support the initial hypothesis of the study but suggests the opposite: the acclimation to a cold environment results in higher desiccation tolerance. HIGHLIGHTS ● Porphyra linearis and Pyropia endiviifolia are remarkably tolerant to desiccation and freezing.● Antarctic P. endiviifolia is remarkably tolerant to desiccation and freezing.● Mechanisms of freezing tolerance could induce a higher tolerance to desiccation. [ABSTRACT FROM AUTHOR]

Background and Aims Lichens represent a symbiotic relationship between at least one fungal and one photosynthetic partner. The association between the lichen-forming fungus Mastodia tessellata (Verrucariaceae) and different species of Prasiola (Trebouxiophyceae) has an amphipolar distribution and represents a unique case study for the understanding of lichen symbiosis because of the macroalgal nature of the photobiont, the flexibility of the symbiotic interaction and the co-existence of free-living and lichenized forms in the same microenvironment. In this context, we aimed to (1) characterize the photosynthetic performance of co-occurring populations of free-living and lichenized Prasiola and (2) assess the effect of the symbiosis on water relations in Prasiola , including its tolerance of desiccation and its survival and performance under sub-zero temperatures. Methods Photochemical responses to irradiance, desiccation and freezing temperature and pressure–volume curves of co-existing free-living and lichenized Prasiola thalli were measured in situ in Livingston Island (Maritime Antarctica). Analyses of photosynthetic pigment, glass transition and ice nucleation temperatures, surface hydrophobicity extent and molecular analyses were conducted in the laboratory. Key Results Free-living and lichenized forms of Prasiola were identified as two different species: P. crispa and Prasiola sp. respectively. While lichenization appears to have no effect on the photochemical performance of the alga or its tolerance of desiccation (in the short term), the symbiotic lifestyle involves (1) changes in water relations, (2) a considerable decrease in the net carbon balance and (3) enhanced freezing tolerance. Conclusions Our results support improved tolerance of sub-zero temperature as the main benefit of lichenization for the photobiont, but highlight that lichenization represents a delicate equilibrium between a mutualistic and a less reciprocal relationship. In a warmer climate scenario, the spread of the free-living Prasiola to the detriment of the lichen form would be likely, with unknown consequences for Maritime Antarctic ecosystems. [ABSTRACT FROM AUTHOR]

Cinnamomum cassia is a medicinal plant whose use has demonstrated benefits on body weight, blood pressure, glucose, and lipids. This study aimed to evaluate the effect of C. cassia on arterial stiffness and endothelial dysfunction (ED) in patients with type 2 diabetes mellitus (T2DM). A randomized, double-blind, placebo-controlled clinical trial was carried out in 18 subjects aged 40–65 years, with a diagnosis of T2DM of one year or less since diagnosis and treated with Metformin 850 mg daily. Patients were randomly assigned to receive either C. cassia or a placebo in 1000 mg capsules, thrice a day, before each meal for 12 weeks. At baseline and after 12 weeks of intervention, brachial-ankle pulse wave velocity and Flow Mediated Dilation were measured, as well as body weight, body mass index (BMI), blood pressure (BP), fasting glucose (FG), glycated hemoglobin A1c (HbA1c), total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and very low density lipoprotein cholesterol, respectively, triglycerides, creatinine, and transaminases. The Mann–Whitney U test for differences between groups and the Wilcoxon signed-rank test for intragroup differences were used, and a P ≤ .05 was considered statistically significant. After C. cassia administration, statistically significant reductions in body weight (81.4 ± 10.4 kg vs. 79.9 ± 9.0 kg, P = .037), BMI (30.6 ± 4.2 kg/m2 vs. 30.1 ± 4.2 kg/m2, P = .018), and HbA1c (53 ± 5.4 mmol/mol vs. 45 ± 2.1 mmol/mol, P = .036) were observed. No changes statistically significant on arterial stiffness, ED, FG, BP, and lipids were observed. C. cassia administration decreases body weight, BMI, and HbA1c without statistically significant changes on arterial stiffness, ED, FG, BP, and lipids. CTR Number: NCT04259606 [ABSTRACT FROM AUTHOR]

In this paper, we analyze the lithic assemblages from three sites from the Central Plateau of Santa Cruz in the Argentine Patagonia. Functional analysis was combined with a techno-morphological and distributional approach, the investigation on raw materials and the study of the technological strategies of production and consumption. The significance of combining functional analysis with other research methods involving lithic remains is emphasized. By articulating different methodologies, it is possible to understand the systems of technological organization. Two sites refer to Final Pleistocene occupations (Cerro Tres Tetas 1 and Casa del Minero 1). The integration of approaches showed the diversity of strategies developed in the production and use of tools, as well as the existence of activity areas within the sites. The third site is a Middle Holocene context (Cueva 13 of Los Toldos). The combination of perspectives allowed a redefinition of the toolkit structure and showed that blade production was part of a standardized technological system. [ABSTRACT FROM AUTHOR]

Aurivillius layered oxides with general formula (Bi2O2)(Am−1BmO3m+1) stand out among room-temperature magnetoelectric multiferroics for their large magnetization. However, despite extensive research, there is an obvious lack of understanding of their magnetism. The chemical design strategy for obtaining multiferroism involves the incorporation of M3+ magnetic cations at the B-site of well-known ferroelectric compounds such as Bi4Ti3O12 (m = 3). We report here a study of the magnetism and dielectric properties of Aurivillius Bi4Ti3 − 2xNbxFexO12 phases with x ≥ 1 up to 1.2, which correspond to magnetic cation fractions at the B site between 0.33 and 0.4 above the threshold for percolation. This is a three-layer system, less prone to the formation of intergrowths, which nominally contains Fe3+ as single magnetic species. Despite that, a rich phenomenology is uncovered. Coexisting magnetic orders are present in the Aurivillius compounds, and a Morin-like transition takes place at low temperatures. The dielectric characterization does not show any associated anomaly that could indicate a polymorphic phase transition but the appearance of relaxor-like characteristics. Possible scenarios are discussed, which involve the presence of Fe2+, cation partitioning between nonequivalent B-sites, and the development of polar nanodomains within a ferroelectric phase at a spin reorientation transition. [ABSTRACT FROM AUTHOR]

Lead-free ferroelectric Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 stands out among environmentally friendly alternatives to commercial Pb(Zr,Ti)O 3 piezoceramics for its large piezoelectric coefficients, and it is especially suitable for applications in which thermal depoling is not an issue like bio-implanted devices. However, ceramic processing by conventional means consistently results in exaggerated grain growth, which compromises reliability and has prevented its transfer to industry. We report here the application of high-energy milling for the mechanosynthesis of nanocrystalline Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 powders with enhanced reactivity, and to the control of grain growth during ceramic processing to obtain materials with tailored microstructures and decreasing grain sizes down to the sub-10 µm range. Characterization of the electrical and electromechanical properties was accomplished and uncovered triggering of a new mechanism for very large strain under electric field in fine-grained ceramics. Process optimization by precursor selection and preliminary up-scaling studies are also presented. [ABSTRACT FROM AUTHOR]

Results of the study of artifact lithic assemblages recovered from systematic excavations of shell middens on the northern coast of Santa Cruz (Patagonia Argentina), are presented. The characteristics and composition of lithic assemblages are analyzed to discuss functionality and integrity of the archaeological sites, and also to evaluate general trends of the technological organization of human groups that inhabited the area. This work represents an initial approach to the interpretation of the archaeological record of coastal shell middens from the study of lithic artifact assemblages recovered in stratigraphic contexts. The evidence from the artifact assemblages allows discussion of the activities that hunter gatherers carried out on shell middens, as well as issues of technological organization of manufacture of stone artifacts and the strategies related to exploitation of lithic raw materials in the study area. Coastal shell middens are places were multiple activities were performed. Regarding lithic technology, the manufacture and maintenance of stone tools, the use thereof, and the discarding of tools and debitage are the activities most represented. [ABSTRACT FROM AUTHOR]

The broadband dielectric properties of high sensitivity piezoelectric 0.36BiScO3-0.64PbTiO3 ceramics with average grain sizes from 1.6 μm down to 26 nm were investigated in the 100–500 K temperature range. The grain size dependence of the dielectric permittivity was analysed within the effective medium approximation. It was found that the generalised core-shell (or brick wall) model correctly explains the size dependence down to the nanoscale. For the first time, the grain bulk and boundary properties were obtained without making any assumptions of values of the parameters or simplifications. Two contributions to dielectric permittivity of the grain bulk are described. The first is the size-independent one, which follows the Curie-Weiss law. The second one is shown to plausibly follow the Kittel's law. This seems to suggest the unexpected persistence of mobile ferroelectric domains at the nanoscale (26 nm grains). Alternative explanations are discussed. [ABSTRACT FROM AUTHOR]

Aurivillius compounds with the general formula (Bi2O2)(An−1BnO3n+1) are a highly topical family of functional layered oxides currently under investigation for room-temperature multiferroism. A chemical design strategy is the incorporation of magnetically active BiMO3 units (M: Fe3+, Mn3+, Co3+ ...) into the pseudo-perovskite layer of known ferroelectrics like Bi4Ti3O12, introducing additional oxygen octahedra. Alternatively, one can try to directly substitute magnetic species for Ti4+ in the perovskite slab. Previous reports explored the introduction of the M3+ species, which required the simultaneous incorporation of a 5+ cation, as for the Bi4Ti3−2xNbxFexO12 system. A larger magnetic fraction might be attained if Ti4+ is substituted with Mn4+, though it has been argued that the small ionic radius prevents its incorporation into the pseudo-perovskite layer. We report here the mechanosynthesis of Aurivillius Bi4Ti2−xMnxNb0.5Fe0.5O12 (n = 3) compounds with increasing Mn4+ content up to x = 0.5, which corresponds to a magnetic fraction of 1/3 at the B-site surpassing the threshold for percolation, and equal amounts of Mn4+ and Fe3+. The appearance of ferromagnetic superexchange interactions and magnetic ordering was anticipated and is shown for phases with x ≥ 0.3. Ceramic processing was accomplished by spark plasma sintering, which enabled electrical measurements that demonstrated ferroelectricity for all Mn4+-containing Aurivillius compounds. This is a new family of layered oxides and a promising alternative single-phase approach for multiferroism. [ABSTRACT FROM AUTHOR]

Abstract: The xBiFeO3–(1− x)PbTiO3 solid solution is nowadays one of the most promising multiferroic systems. However, the obtaining of single phases with a high crystallinity is difficult by the conventional methods. In this work, the mechanochemical method has been optimized, testing different parameters in the reaction to obtain the suitable conditions of synthesis. The investigated parameters were: the atmosphere conditions and the material of the reaction medium. Single phases with compositions belonging to the whole system (0≤ x ≤1) have been obtained, being the mechanochemical reaction with tungsten carbide vessel the best synthesis medium. The structural characterization of the obtained powders has been carried out by XRD and microstructures of powdered samples have been studied by SEM and TEM. [Copyright &y& Elsevier]

The combination of non-conventional methods of synthesis (mechanosynthesis) and sintering (spark plasma sintering, SPS) has been used for the first time to process dense, fine-grained ceramics of the (1− x)NaNbO3– xSrTiO3 system. Dielectric properties have been measured across main phase transitions in the system for the submicrometer-structured ceramic materials processed by SPS, and are comparable with those of ceramics prepared by conventional sintering. This approach thus allows grain growth to be controlled while retaining properties, and provides the possibility of processing ceramics of alkaline niobate-based perovskite solid solutions with a homogeneous, fine-grained microstructure and good functionality. [ABSTRACT FROM AUTHOR]

The mechanosynthesis of piezoelectric perovskite 0.92Pb(Zn⅓Nb2/3)O3-0.08PbTiO3 (PZN-PT) by direct mechanochemical activation of the constituent oxides has been studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM). This and the PbO flux method are the only two procedures that have succeeded in synthesizing this phase, which has recently been shown to present very high electromechanical response. The thermal stability of the single perovskite phase powders has been studied by differential thermal analysis/thermogravimetry and by high-temperature XRD as a function of mechanical activation time and pressure. The phase was found to transform into a pyrochlore type structure at temperatures above 400°C. The transformation presented a significant time dependence, and it was slowed down by increasing mechanical activation time and by the application of pressures by hot pressing. Sintering experiments were accomplished and 85% density, 77% perovskite-phase ceramics were obtained after heating at 1000°C for 1 h. Hot pressing at this temperature failed to increase the percentage of perovskite phase. Results are discussed, and procedures for obtaining dense single-phase PZN-PT-based ceramics with ultrahigh piezoelectricity are proposed. [ABSTRACT FROM AUTHOR]

A novel mechanochemical activation route has been applied in order to obtain the n=1–4 and ∞ members of the Sr2[Srn−1TinO3n+1] Ruddlesden–Popper series. The evolution of the (n+1)SrO:nTiO2 powder mixtures during mechanical treatment was followed by X-ray powder diffraction in all cases. Except for the 2SrO:TiO2 composition, SrTiO3 was always mechanosynthesized. High-energy milling of 2SrO:TiO2 sample resulted in the formation of nanosized Sr2TiO4, which is the only K2NiF4-type oxide prepared by mechanical treatment until now.The mechanical treatment was followed by annealing at different temperatures to establish the optimized protocol for synthesis of each member of the series. SrTiO3, Sr2TiO4 and Sr3Ti2O7 were obtained with very important decreases in the formation temperatures and reaction times as compared with the traditional ceramic method. Final and milled products were studied by X-ray powder diffraction at room and increasing temperatures, and by thermal analysis and scanning and high resolution transmission electron microscopy. [Copyright &y& Elsevier]

Summary: Desiccation tolerant plants can survive extreme water loss in their vegetative tissues. The fern Anemia caffrorum produces desiccation tolerant (DT) fronds in the dry season and desiccation sensitive (DS) fronds in the wet season, providing a unique opportunity to explore the physiological mechanisms associated with desiccation tolerance.Anemia caffrorum plants with either DT or DS fronds were acclimated in growth chambers. Photosynthesis, frond structure and anatomy, water relations and minimum conductance to water vapour were measured under well‐watered conditions. Photosynthesis, hydraulics, frond pigments, antioxidants and abscisic acid contents were monitored under water deficit.A comparison between DT and DS fronds under well‐watered conditions showed that the former presented higher leaf mass per area, minimum conductance, tissue elasticity and lower CO2 assimilation. Water deficit resulted in a similar induction of abscisic acid in both frond types, but DT fronds maintained higher stomatal conductance and upregulated more prominently lipophilic antioxidants.The seasonal alternation in production of DT and DS fronds in A. caffrorum represents a mechanism by which carbon gain can be maximized during the rainy season, and a greater investment in protective mechanisms occurs during the hot dry season, enabling the exploitation of episodic water availability. [ABSTRACT FROM AUTHOR]

Synthesis, X-rays, TEM and HREM studies of the composition x=0.25 of the solid solution Sb2W1−xMoxO6 are reported. The phase crystallises in the monoclinic system, space group C2 and the cell parameters of its average structure are a=11.1296(6) A˚, b=9.8868(9) A˚, a=18.501(2) A˚ and β=96.951(9)°. Mo and W atoms are ordered in the 1/3 ratio. Twining and extended defects have been studied by TEM and HREM. [Copyright &y& Elsevier]

The key role of cell walls in setting mesophyll conductance to CO2 (g m) and, consequently, photosynthesis is reviewed. First, the theoretical properties of cell walls that can affect g m are presented. Then, we focus on cell wall thickness (T cw) reviewing empirical evidence showing that T cw varies strongly among species and phylogenetic groups in a way that correlates with g m and photosynthesis; that is, the thicker the mesophyll cell walls, the lower the g m and photosynthesis. Potential interplays of g m, T cw, dehydration tolerance, and hydraulic properties of leaves are also discussed. Dynamic variations of T cw in response to the environment and their implications in the regulation of photosynthesis are discussed, and recent evidence suggesting an influence of cell wall composition on g m is presented. We then propose a hypothetical mechanism for the influence of cell walls on photosynthesis, combining the effects of thickness and composition, particularly pectins. Finally, we discuss the prospects for using biotechnology for enhancing photosynthesis by altering cell wall-related genes. [ABSTRACT FROM AUTHOR]

Piezoresponse force microscopy has been used for the local characterization of high sensitivity piezoelectric BiScO3-PbTiO3 ceramics with compositions close to the morphotropic phase boundary, with decreasing grain sizes down to 28 nm. The use of this high resolution technique has allowed not only the analysis of the evolution of the ferroelectric domain configurations, with the disappearance of ferroelastic domains at the nanoscale, but also to establish the existence of correlations among the polarization of adjacent single-domain grains and the formation of inversion superdomains. The effect of the grain size reduction on the piezoelectric coefficients was also studied. Finally, piezoelectric loops have been obtained on the smallest grains, and some distinctive features, such as an atypical clockwise hysteresis is discussed and related to high resistivity grain boundaries. [ABSTRACT FROM AUTHOR]

Desiccation tolerant (DT) plants withstand complete cellular dehydration, reaching relative water contents (RWC) below 30% in their photosynthetic tissues. Desiccation sensitive (DS) plants exhibit different degrees of dehydration tolerance (DHT), never surviving water loss >70%. To date, no procedure for the quantitative evaluation of DHT extent exists that is able to discriminate DS species with differing degrees of DHT from truly DT plants. We developed a simple, feasible and portable protocol to differentiate between DT and different degrees of DHT in the photosynthetic tissues of seed plants and between fast desiccation (< 24 h) tolerant (FDT) and sensitive (FDS) bryophytes. The protocol is based on (1) controlled desiccation inside Falcon tubes equilibrated at three different relative humidities that, consequently, induce three different speeds and extents of dehydration and (2) an evaluation of the average percentage of maximal photochemical efficiency of PSII (Fv/fm) recovery after rehydration. Applying the method to 10 bryophytes and 28 tracheophytes from various locations, we found that (1) imbibition of absorbent material with concentrated salt‐solutions inside the tubes provides stable relative humidity and avoids direct contact with samples; (2) for 50 ml capacity tubes, the optimal plant amount is 50–200 mg fresh weight; (3) the method is useful in remote locations due to minimal instrumental requirements; and (4) a threshold of 30% recovery of the initial Fv/fm upon reaching RWC ≤ 30% correctly categorises DT species, with three exceptions: two poikilochlorophyllous species and one gymnosperm. The protocol provides a semi‐quantitative expression of DHT that facilitates comparisons of species with different morpho‐physiological traits and/or ecological attributes. [ABSTRACT FROM AUTHOR]

Perovskite BiFeO3 and YMnO3 are both multiferroic materials with distinctive magnetoelectric coupling phenomena. Owing to this, the Y1−xBix Mn1−xFexO3 solid solution seems to be a promising system, though poorly studied. This is due to the metastable nature of the orthorhombic perovskite phase of YMnO3 at ambient pressure, and to the complexity of obtaining pure rhombohedral phases for BiFeO3-rich compositions. In this work, nanocrystalline powders across the whole perovskite system were prepared for the first time by mechanosynthesis in a high-energy planetary mill, avoiding high pressure and temperature routes. Thermal decomposition temperatures were determined, and structural characterization was carried out by X-ray powder diffraction and Raman spectroscopy on thermally treated samples of enhanced crystallinity. Two polymorphic phases with orthorhombic Pnma and rhombohedral R3c h symmetries, and their coexistence over a wide compositional range were found. A gradual evolution of the lattice parameters with the composition was revealed for both phases, which suggests the existence of two continuous solid solutions. Following bibliographic data for BiFeO3, first order ferroic phase transitions were located by differential thermal analysis in compositions with x ≥ 0.9. Furthermore, an orthorhombic-rhombohedral structural evolution across the ferroelectric transition was characterized with temperature-dependent X-ray diffraction. [ABSTRACT FROM AUTHOR]

Concomitant infection with human immunodeficiency virus (HIV) and the Leishmania parasite is a growing public health problem, the result of the former spreading to areas where the latter is endemic. Leishmania infection is usually asymptomatic in immunocompetent individuals, but the proportion of HIV+ individuals in contact with the parasite who remain asymptomatic is not known. The aim of the present work was to examine the use of cytokine release assays in the detection of asymptomatic immune responders to Leishmania among HIV+ patients with no previous leishmaniasis or current symptomatology. Eighty two HIV+ patients (all from Fuenlabrada, Madrid, Spain, where a leishmaniasis outbreak occurred in 2009) were examined for Leishmania infantum infection using molecular and humoral response-based methods. None returned a positive molecular or serological result for the parasite. Thirteen subjects showed a positive lymphoproliferative response to soluble Leishmania antigen (SLA), although the mean CD4+ T lymphocyte counts of these patients was below the normal range. Stimulation of peripheral blood mononuclear cells (PBMC) or whole blood with SLA (the lymphoproliferative assay and whole blood assay respectively), led to the production of specific cytokines and chemokines. Thus, despite being immunocompromised, HIV+ patients can maintain a Th1-type cellular response to Leishmania. In addition, cytokine release assays would appear to be useful tools for detecting these individuals via the identification of IFN-γ in the supernatants of SLA-stimulated PBMC, and of IFN-γ, MIG and IL-2 in SLA-stimulated whole blood. These biomarkers appear to be 100% reliable for detecting asymptomatic immune responders to Leishmania among HIV+ patients. [ABSTRACT FROM AUTHOR]

Summary: Photosynthesis in bryophytes and lycophytes has received less attention than terrestrial plant groups. In particular, few studies have addressed the nonstomatal diffusion conductance to CO2gnsd of these plant groups.Their lower photosynthetic rate per leaf mass area at any given nitrogen concentration compared with vascular plants suggested a stronger limitation by CO2 diffusion. We hypothesized that bryophyte and lycophyte photosynthesis is largely limited by low gnsd. Here, we studied CO2 diffusion inside the photosynthetic tissues and its relationships with photosynthesis and anatomical parameters in bryophyte and lycophyte species in Antarctica, Australia, Estonia, Hawaii and Spain.On average, lycophytes and, specially, bryophytes had the lowest photosynthetic rates and nonstomatal diffusion conductance reported for terrestrial plants. These low values are related to their very thick cell walls and their low exposure of chloroplasts to cell perimeter.We conclude that the reason why bryophytes lie at the lower end of the leaf economics spectrum is their strong nonstomatal diffusion conductance limitation to photosynthesis, which is driven by their specific anatomical characteristics. [ABSTRACT FROM AUTHOR]

During the past decade, massive inundations of holopelagic Sargassum spp. (S. natans I, S. natans VIII, and S. fluitans III), commonly known as sargasso, have drastically affected beaches and coasts throughout the tropical Atlantic, leading to strong forecasting and monitoring efforts. This study aimed to characterize spatiotemporal variation in accumulation levels and morphotype composition of sargasso inundations. Community science initiatives can aid in monitoring sargasso regionally by locally collecting data on morphotype composition and accumulation level. A volunteer network compiled community-contributed photos from the "Sargassum Watch" Epicollect5 digital application. Florida and the Gulf coast showed less susceptibility to high accumulations than other subregions of the tropical Atlantic. S. fluitans III was the most frequently encountered morphotype, though the probability of encountering any of the three morphotypes depended on accumulation level. Despite differences in latitude, the 2021 season demonstrated similar 'peak' sargasso months between South Florida and Mexican Caribbean (May–July), though the intensity and duration of high-accumulation months differed. Much of these composition patterns and accumulation levels were likely related to the proximity of both regions to the Great Atlantic Sargassum Belt and dispersal through wind and water currents. Using community-collected data to outline quantitative trends and patterns in sargasso accumulation levels and composition, this study can be useful for future collaborations and syntheses with other forecasting and monitoring programs. [ABSTRACT FROM AUTHOR]

The role of BiFeO addition on the crystal structure, microstructure, and the electrical and electromechanical properties of high-sensitivity BiNaTiO-BiKTiO ferroelectric ceramics for compositions at the morphotropic phase boundary (MPB) is investigated. A perovskite solid solution from nano-sized BiFeO and BiNaTiO-BiKTiO powders is obtained, in which the persistence of a MPB in the ternary system is demonstrated. The structural characterization, along with the electrical properties, indicates the stabilization of intermediate domain configurations, associated with a decrease of the temperature for the development of the ferroelectric long-range order. As a consequence, high phase-change electromechanical response is found for certain small BiFeO additions. This result is very promising for the processing of textured ceramics taking advantage of the decomposition behaviour of BiFeO. Ceramic texturing is demonstrated, a key technology for developing lead-free piezoelectrics that can replace Pb(Zr,Ti)O. [ABSTRACT FROM AUTHOR]