Inverse transition of labyrinthine domain patterns in ferroelectric thin films.

Phase separation is a cooperative process, the kinetics of which underpin the orderly morphogenesis of domain patterns on mesoscopic scales1,2. Systems of highly degenerate frozen states may exhibit the rare and counterintuitive inverse-symmetry-breaking phenomenon3. Proposed a century ago4, inverse transitions have been found experimentally in disparate materials, ranging from polymeric and colloidal compounds to high-transition-temperature superconductors, proteins, ultrathin magnetic films, liquid crystals and metallic alloys5,6, with the notable exception of ferroelectric oxides, despite extensive theoretical and experimental work on the latter. Here we show that following a subcritical quench, the non-equilibrium self-assembly of ferroelectric domains in ultrathin films of Pb(Zr0.4Ti0.6)O3 results in a maze, or labyrinthine pattern, featuring meandering stripe domains. Furthermore, upon increasing the temperature, this highly degenerate labyrinthine phase undergoes an inverse transition whereby it transforms into the less-symmetric parallel-stripe domain structure, before the onset of paraelectricity at higher temperatures. We find that this phase sequence can be ascribed to an enhanced entropic contribution of domain walls, and that domain straightening and coarsening is predominantly driven by the relaxation and diffusion of topological defects. Computational modelling and experimental observation of the inverse dipolar transition in BiFeO3 suggest the universality of the phenomenon in ferroelectric oxides. The multitude of self-patterned states and the various topological defects that they embody may be used beyond current domain and domain-wall-based7 technologies by enabling fundamentally new design principles and topologically enhanced functionalities within ferroelectric films.

Real-space imaging of non-collinear antiferromagnetic order with a single-spin magnetometer.

Although ferromagnets have many applications, their large magnetization and the resulting energy cost for switching magnetic moments bring into question their suitability for reliable low-power spintronic devices. Non-collinear antiferromagnetic systems do not suffer from this problem, and often have extra functionalities: non-collinear spin order may break space-inversion symmetry and thus allow electric-field control of magnetism, or may produce emergent spin-orbit effects that enable efficient spin-charge interconversion. To harness these traits for next-generation spintronics, the nanoscale control and imaging capabilities that are now routine for ferromagnets must be developed for antiferromagnetic systems. Here, using a non-invasive, scanning single-spin magnetometer based on a nitrogen-vacancy defect in diamond, we demonstrate real-space visualization of non-collinear antiferromagnetic order in a magnetic thin film at room temperature. We image the spin cycloid of a multiferroic bismuth ferrite (BiFeO3) thin film and extract a period of about 70 nanometres, consistent with values determined by macroscopic diffraction. In addition, we take advantage of the magnetoelectric coupling present in BiFeO3 to manipulate the cycloid propagation direction by an electric field. Besides highlighting the potential of nitrogen-vacancy magnetometry for imaging complex antiferromagnetic orders at the nanoscale, these results demonstrate how BiFeO3 can be used in the design of reconfigurable nanoscale spin textures.

Multi-stimuli manipulation of antiferromagnetic domains assessed by second-harmonic imaging.

Among the variety of magnetic textures available in nature, antiferromagnetism is one of the most 'discrete' because of the exact cancellation of its staggered internal magnetization. It is therefore very challenging to probe. However, its insensitivity to external magnetic perturbations, together with the intrinsic sub-picosecond dynamics, make it very appealing for tomorrow's information technologies. Thus, it is essential to understand the microscopic mechanisms governing antiferromagnetic domains to achieve accurate manipulation and control. Using optical second-harmonic generation, a unique and laboratory-available tool, we succeeded in imaging with sub-micrometre resolution both electric and antiferromagnetic orders in the model multiferroic BiFeO3. We show here that antiferromagnetic domains can be manipulated with low power consumption, using sub-coercive electric fields and sub-picosecond light pulses. Interestingly, we also show that antiferromagnetic and ferroelectric domains can behave independently, thus revealing that magneto-electric coupling can lead to various arrangements of the two orders.

Crafting the magnonic and spintronic response of BiFeO3 films by epitaxial strain.

Multiferroics are compounds that show ferroelectricity and magnetism. BiFeO3, by far the most studied, has outstanding ferroelectric properties, a cycloidal magnetic order in the bulk, and many unexpected virtues such as conductive domain walls or a low bandgap of interest for photovoltaics. Although this flurry of properties makes BiFeO3 a paradigmatic multifunctional material, most are related to its ferroelectric character, and its other ferroic property--antiferromagnetism--has not been investigated extensively, especially in thin films. Here we bring insight into the rich spin physics of BiFeO3 in a detailed study of the static and dynamic magnetic response of strain-engineered films. Using Mössbauer and Raman spectroscopies combined with Landau-Ginzburg theory and effective Hamiltonian calculations, we show that the bulk-like cycloidal spin modulation that exists at low compressive strain is driven towards pseudo-collinear antiferromagnetism at high strain, both tensile and compressive. For moderate tensile strain we also predict and observe indications of a new cycloid. Accordingly, we find that the magnonic response is entirely modified, with low-energy magnon modes being suppressed as strain increases. Finally, we reveal that strain progressively drives the average spin angle from in-plane to out-of-plane, a property we use to tune the exchange bias and giant-magnetoresistive response of spin valves.

Foaming and emulsifying properties of porcine red cell protein concentrate.

This work focuses on studying the effects of pH (7.0 and 4.5) and protein concentration on the foaming and emulsifying properties of fresh (F) and spray-dried (SD) porcine red cell protein (RCP) concentrates in order to evaluate the proper use of this blood protein as a functional food ingredient. Also, protein solubility is measured through the pH range from 3.0 to 8.0. In each case, all concentrates show a high solubility, although this is significantly affected by pH. Spray drying slightly reduces the solubility at mild acid and neutral conditions. The foaming capacity is found to be dependent on pH as well as on the drying treatment. SD-RCP concentrates show better foaming capacity than F-RCP. The minimum protein concentration required to attain the highest foaming capacity is found under acid pH for the spray-dried concentrates. Although F-RCP shows low foam stability at acid and neutral pH, spray drying and protein content enhance the stability of foams. Emulsifying properties show dependence on pH as well as on protein content. Furthermore, spray drying affects the emulsifying properties but in different ways, depending on pH and protein concentration.

Antiferromagnetic textures in BiFeO3 controlled by strain and electric field.

Antiferromagnetic thin films are currently generating considerable excitement for low dissipation magnonics and spintronics. However, while tuneable antiferromagnetic textures form the backbone of functional devices, they are virtually unknown at the submicron scale. Here we image a wide variety of antiferromagnetic spin textures in multiferroic BiFeO3 thin films that can be tuned by strain and manipulated by electric fields through room-temperature magnetoelectric coupling. Using piezoresponse force microscopy and scanning NV magnetometry in self-organized ferroelectric patterns of BiFeO3, we reveal how strain stabilizes different types of non-collinear antiferromagnetic states (bulk-like and exotic spin cycloids) as well as collinear antiferromagnetic textures. Beyond these local-scale observations, resonant elastic X-ray scattering confirms the existence of both types of spin cycloids. Finally, we show that electric-field control of the ferroelectric landscape induces transitions either between collinear and non-collinear states or between different cycloids, offering perspectives for the design of reconfigurable antiferromagnetic spin textures on demand.

Mapping the spatial distribution of charge carriers in LaAlO3/SrTiO3 heterostructures.

At the interface between complex insulating oxides, novel phases with interesting properties may occur, such as the metallic state reported in the LaAlO(3)/SrTiO(3) system . Although this state has been predicted and reported to be confined at the interface, some studies indicate a much broader spatial extension, thereby questioning its origin. Here, we provide for the first time a direct determination of the carrier density profile of this system through resistance profile mappings collected in cross-section LaAlO(3)/SrTiO(3) samples with a conducting-tip atomic force microscope (CT-AFM). We find that, depending on specific growth protocols, the spatial extension of the high-mobility electron gas can be varied from hundreds of micrometres into SrTiO(3) to a few nanometres next to the LaAlO(3)/SrTiO(3) interface. Our results emphasize the potential of CT-AFM as a novel tool to characterize complex oxide interfaces and provide us with a definitive and conclusive way to reconcile the body of experimental data in this system.

Color stabilization of porcine hemoglobin during spray-drying and powder storage by combining chelating and reducing agents.

This work focuses on the effects of adding a chelating agent - such as nicotinic acid (NA, 2% w/v) or nicotinamide (Nam, 2.5% w/v) - along with glucose as a reducing agent (G, 10% w/v) to fresh porcine hemoglobin in order to stabilize its red color during spray-drying and powder storage at room temperature. Correlations between the CIELAB color parameters and the relative percentages of the different hemoglobin derivatives (liganded and deliganded ferrohemoglobin, and methemoglobin) were analyzed. The results indicate that, although little effects could be observed for any of the combined treatments on fresh hemoglobin, they were effective against pigment autoxidation during dehydration and subsequent storage. From the results, it can also be concluded that glucose was the main contributor to the color stabilization of the hemoglobin powder, probably due to its high water retention capacity.

Simultaneous application of microbial transglutaminase and high hydrostatic pressure to improve heat induced gelation of pork plasma.

The effects of treating porcine plasma with microbial tranglutaminase (MTGase) under high hydrostatic pressure (HHP) were studied as a means of improving its gel-forming properties when subsequently heated at pH 5.5, near the pH of meats. Plasma containing varying levels of commercial MTGase was pressurized (400MPa, room temperature, pH 7) for different times, and adjusted to pH 5.5 prior to heating to induce gelation. MTGase-treatment under HHP led to greater enhancement of heat-induced plasma gel properties as compared to control samples. The greatest improvements were achieved by pressurising plasma with 43.3U MTGase/g protein for 30min, thereby achieving recoveries of 49% and 63% in fracture force (gel strength) and fracture distance (gel deformability) of the subsequently heat-induced gels, respectively, relative to gel properties obtained by heating untreated plasma at physiological conditions (pH 7.5).

Functional and quality characteristics of the red blood cell fraction from biopreserved porcine blood as influenced by high pressure processing.

The effects of high hydrostatic pressure (HHP) processing, at 400MPa for 15min at 20°C, on the microbiological and functional characteristics of the red blood cell (RBC) fraction obtained from porcine blood, previously preserved by means of lactic acid bacteria (LAB) was studied. Biopreservation was achieved by incubation of inulin-enriched blood inoculated with a LAB strain (Enterococcus raffinosus PS99) for 72h at 5°C. Results showed that incubation of blood with added E. raffinosus followed by HHP treatment reduced the levels of contaminant coliforms, proteolytic, hemolytic bacteria, and Pseudomonas spp. on RCB. Color parameters, protein solubility, foaming and emulsifying properties, as well as texture and water holding capacity of heat-induced gels from RBC were not seriously damaged by the combined treatments. This is a new approach to process and preserve animal blood fractions for the development of functional and/or nutritional food ingredients with added value.

[Capsule endoscopy interpretation: the role of physician extenders]. / Interpretación de la cápsula endoscópica: el papel del personal no especializado.

BACKGROUND AND AIMS: capsule endoscopy (CE) allows for a new era in small-bowel examination. Nevertheless, physicians time for CE-interpretation remains longer than desirable. Alternative strategies to physicians have not been widely investigated. The aim of this study was to evaluate the accuracy of physician extenders in CE-interpretation. MATERIAL AND METHODS: one CE-experienced gastroenterologist and two physician extenders reviewed independently 20 CE-procedures. Each reader was blinded to the findings of their colleagues. A consensus formed by the readers and a second CE-experienced gastroenterologist was used as gold standard. Number, type and location of images selected, character of CE-exams and their relationship with indications were recorded. Gastric emptying time (GEt), small-bowel transit time (SBTt) and time spent by readers were also noted. RESULTS: sensitivity and specificity for "overall" lesions was 79 and 99% for the gastroenterologist; 86 and 43% for the nurse; and 80 and 57% for the resident. All 34 "major" lesions considered by consensus were found by the readers. Agreement between consensus and readers for images classification and procedures interpretation was good to excellent (? from 0.55 to 1). No significant differences were found in the GEt and SBTt obtained by consensus and readers. The gastroenterologist was faster than physician extenders (mean time spent was 51.9 +/- 13.5 minutes versus 62.2 +/- 19 and 60.9 +/- 17.1 for nurse and resident, respectively; p < 0.05). CONCLUSIONS: physician extenders could be the perfect complement to gastroenterologists for CE-interpretation but gastroenterologists should supervise their findings. Future cost-efficacy analyses are required to assess the benefits of this alternative.

[Study of frequency, distribution and diagnostic performance in synchronic neoplastic lesions of colorectal carcinoma]. / Estudio de la frecuencia, distribución y rendimiento diagnóstico en las lesiones neoplásicas sincrónicas del carcinoma colo-rectal.

AIM: To analyse the frequency, characteristics and diagnosis of synchronic neoplastic lesions in colorectal cancer. METHODS: A review was carried out of 384 colorectal cancers, diagnosed through complete colonoscopy and resected. The synchronic cancers and the characteristics of the adenomas were determined: number, size, histological type, dysplasia, as well as their localisation in the colon and with respect to the carcinoma. RESULTS: Twenty-eight synchronic cancers were found (7.3% of the total); 8 developed tumours and 20 malignant polyps. In 54.4% of the cases there was a synchronic adenoma. In patients with synchronic lesions, 43% showed an advanced adenoma. Twenty percent of the synchronic polyps found were proximal to the splenic flexure; 41% were distal and 38% had both localisations. Fifty-nine point one percent of the patients had some adenoma proximal to the cancer, with criteria of advanced adenoma in 13.9%. The distribution of the adenomas was more uniformly spread in the cancers with a proximal localisation (p = 0.038). Seventeen percent of the distal cancers presented synchronic lesions with a proximal colon localisation exclusively. Partial endoscopies would diagnose the distal cancers, but would omit a synchronic adenoma in 42.3% of the sigmoidoscopies and 40% of the short colonoscopies. CONCLUSIONS: High rates of carcinoma and synchronic adenomas were registered. We underline the high index of advanced adenomas and the frequency of synchronic lesions proximal to the cancer, which is why incomplete colonoscopies, although allowing the diagnosis of the distal cancer, omit a high percentage of synchronic adenomas, including advanced lesions. All of this confirms the need to perform a complete pre-, intra- and post operational colonoscopy in resectable colorectal cancer.

[New applications of capsule endoscopy: PILLCAMTM ESO]. / Nuevas aplicaciones de la cápsula endoscópica: PILLCAM ESO.

Capsule endoscopy has opened a new era in small bowel examination. Its indications are now well-defined and currently, wireless capsule endoscopy is considered as the first-line imaging tool for the diagnosis of small bowel diseases. ECE has been shown to be feasible, safe and a good alternative technique in patients refusing conventional endoscopy. Although results reported in both GERD and cirrhotic patients are encouraging, great differences in terms of accuracy (particularly in GERD patients) have been found in published studies. These differences have been attributed to study designs, the lack of adequate experience and inconvenience of ingestion protocols. In summary, more large-scale studies evaluating the new 14-fps capsule, adequate ECE-experience and new modified ingestion protocols are still needed.

ABO incompatibility does not influence transfusion requirements in patients undergoing single-unit umbilical cord blood transplantation.

Hematopoietic stem cell transplantation is usually performed without considering the ABO compatibility between donor and recipient. There are few studies analyzing ABO matching impact on transfusion outcome of umbilical cord blood transplantation (UCBT) recipients. The aim of this study was to analyze factors influencing transfusion outcome, highlighting the ABO matching between donor and recipient. This study has reviewed data from 318 patients who underwent single unit UCBT at la Fe University Hospital from January 2000 to December 2014. There were no differences between RBC and platelet (PLT) requirements or RBC and PLT transfusion independence according to ABO matching between donor and recipient. RBC and PLT requirements were statistically correlated (ρ=0,841, P<0.001). A total of 170 and 188 patients achieved RBC and PLT independence, respectively, within 180 days after UCBT. Persistence of recipient isoagglutinins was detected in 6.8% of patients with major ABO incompatibility at median of 176 days (103-269) after UCBT. Autoimmune haemolytic anemia was diagnosed in 15 patients, 12 of them due to cold antibodies. In conclusion, ABO matching has not influenced transfusion requirements of patients undergoing UCBT.

Strain and Magnetic Field Induced Spin-Structure Transitions in Multiferroic BiFeO3.

The magnetic-field-dependent spin ordering of strained BiFeO3 films is determined using nuclear resonant scattering and Raman spectroscopy. The critical field required to destroy the cycloidal modulation of the Fe spins is found to be significantly lower than in the bulk, with appealing implications for field-controlled spintronic and magnonic devices.

Large elasto-optic effect and reversible electrochromism in multiferroic BiFeO3.

The control of optical fields is usually achieved through the electro-optic or acousto-optic effect in single-crystal ferroelectric or polar compounds such as LiNbO3 or quartz. In recent years, tremendous progress has been made in ferroelectric oxide thin film technology-a field which is now a strong driving force in areas such as electronics, spintronics and photovoltaics. Here, we apply epitaxial strain engineering to tune the optical response of BiFeO3 thin films, and find a very large variation of the optical index with strain, corresponding to an effective elasto-optic coefficient larger than that of quartz. We observe a concomitant strain-driven variation in light absorption--reminiscent of piezochromism--which we show can be manipulated by an electric field. This constitutes an electrochromic effect that is reversible, remanent and not driven by defects. These findings broaden the potential of multiferroics towards photonics and thin film acousto-optic devices, and suggest exciting device opportunities arising from the coupling of ferroic, piezoelectric and optical responses.

Identification of a novel HLA-B*50 allele, HLA-B*50:01:08, in a Spanish hematological patient.

HLA-B*50:01:08 differs from B*50:01:01 at nucleotides g.1206T>A (intron 3) and g.1658G>A (exon 4).

[Nutritional composition of infant milk formulas. Level of compliance in their manufacture and adequacy of nutritional needs]. / Composición nutricional de las leches infantiles. Nivel de cumplimiento en su fabricación y adecuación a las necesidades nutricionales.

INTRODUCTION: A high percentage of infants are fed with infant formulas. The aim of this study was to assess compliance with the Technical and Safety Regulations in the manufacture of Spanish infant formulas, analyse their adequacy to the recommendations of nutritional composition and the Dietary References Intakes for infants. MATERIALS AND METHODS: A total of 31 infant formulas were analysed, of which 18 were infant formulas, 10 follow-on formulas, and 3 growing-up milks. The European Technical and Safety Regulations, the Spanish Dietary Reference Intakes and the Institute of Medicine of the United States and Canada, were used for the assessment of compliance and adequacy. RESULTS: The energy and macronutrient content of analysed infant formulas is placed in the middle of the range indicated in the Technical and Safety Regulations, and meets the recommended amounts. However, most micronutrients such as phosphorus, calcium, retinol, vitamin D, E, C, B6, B12, thiamin, riboflavin, and folate are at the lower limit of the Technical and Safety Regulations. However, the recommended consumption of infant formulas exceeded the Dietary References Intakes for vitamin E, C, retinol, vitamin B and folate, and vitamin B12 for follow-on formulas. CONCLUSIONS: Infant formulas are within the reference values of the European Technical and Safety Regulations in energy and macronutrients, but we believe that the level of micronutrients should be reviewed, based on current scientific data on infant requirements and possible adverse effects.

Heat-induced gelation mechanism of blood plasma modulated by cysteine.

This work aims to determine changes at molecular level of plasma proteins provoked by adding cysteine (Cys, 0.025% to 0.35% w/v) as a reducing agent and their relationship with the heat-induced gel properties obtained when subsequently the solutions were submitted to a thermal treatment. Results show that adding Cys to plasma solutions at concentrations ≥0.15% actually entails modifications in the secondary structure of their main proteins, that is, serum albumin-α-helix rich-and globulin fraction-ß-sheet rich. Basically, a reduction of the intensity of the infrared (IR) bands assigned to both structures takes place concomitant to an increase of extended structures that seem to act as intermediates for the subsequent protein aggregation process through nonnative intermolecular ß-sheets. Cleavage of disulfide bonds is also evidenced at Cys concentrations ≥0.15% by nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with the effects being directly proportional to Cys concentration. However, beneficial effects on gel hardness are gradually obtained at Cys concentrations ≤0.15%, that is, when the effects at molecular level are at most just budding, while not more improvements on this textural parameter are obtained at higher Cys concentrations. By contrast, water retention capacity is gradually diminishing as Cys concentration increases, but with a significant reduction only obtained at the highest tested concentration. These results suggest a negative effect of Cys on gel microstructure at high concentrations, which probably can be attributed to protein aggregation taking place at room temperature.

Phytochemical analysis of Phillyrea latifolia L., a new source of oleuropeoside.

As a part of our studies on the biologically active substances from Spanish plants, we have undertaken an investigation of the chemical constituents of a typical mediterranean species, Phillyrea latifolia L. (Oleaceae). Two secoiridoid glycosides, three phenylpropanoid glycosides, one lignane and two triterpenic acids were isolated from the leaves of this species and identified. The phytochemical analysis of the aerial parts of P. latifolia revealed that it is a rich source of oleuropeoside.