3,452 research outputs found

    Topological defects and misfit strain in magnetic stripe domains of lateral multilayers with perpendicular magnetic anisotropy

    Get PDF
    Stripe domains are studied in perpendicular magnetic anisotropy films nanostructured with a periodic thickness modulation that induces the lateral modulation of both stripe periods and inplane magnetization. The resulting system is the 2D equivalent of a strained superlattice with properties controlled by interfacial misfit strain within the magnetic stripe structure and shape anisotropy. This allows us to observe, experimentally for the first time, the continuous structural transformation of a grain boundary in this 2D magnetic crystal in the whole angular range. The magnetization reversal process can be tailored through the effect of misfit strain due to the coupling between disclinations in the magnetic stripe pattern and domain walls in the in-plane magnetization configuration

    Controlled nucleation of topological defects in the stripe domain patterns of Lateral multilayers with Perpendicular Magnetic Anisotropy: competition between magnetostatic, exchange and misfit interactions

    Full text link
    Magnetic lateral multilayers have been fabricated on weak perpendicular magnetic anisotropy amorphous Nd-Co films in order to perform a systematic study on the conditions for controlled nucleation of topological defects within their magnetic stripe domain pattern. A lateral thickness modulation of period ww is defined on the nanostructured samples that, in turn, induces a lateral modulation of both magnetic stripe domain periods λ\lambda and average in-plane magnetization component MinplaneM_{inplane}. Depending on lateral multilayer period and in-plane applied field, thin and thick regions switch independently during in-plane magnetization reversal and domain walls are created within the in-plane magnetization configuration coupled to variable angle grain boundaries and disclinations within the magnetic stripe domain patterns. This process is mainly driven by the competition between rotatable anisotropy (that couples the magnetic stripe pattern to in-plane magnetization) and in-plane shape anisotropy induced by the periodic thickness modulation. However, as the structural period ww becomes comparable to magnetic stripe period λ\lambda, the nucleation of topological defects at the interfaces between thin and thick regions is hindered by a size effect and stripe domains in the different thickness regions become strongly coupled.Comment: 10 pages, 7 figures, submitted to Physical Review

    Human myiasis in Ecuador.

    Get PDF
    We review epidemiological and clinical data on human myiasis from Ecuador, based on data from the Ministry of Public Health (MPH) and a review of the available literature for clinical cases. The larvae of four flies, Dermatobia hominis, Cochliomyia hominivorax, Sarcophaga haemorrhoidalis, and Lucilia eximia, were identified as the causative agents in 39 reported clinical cases. The obligate D. hominis, causing furuncular lesions, caused 17 (43.5%) cases distributed along the tropical Pacific coast and the Amazon regions. The facultative C. hominivorax was identified in 15 (38%) clinical cases, infesting wound and cavitary lesions including orbital, nasal, aural and vaginal, and occurred in both subtropical and Andean regions. C. hominivorax was also identified in a nosocomial hospital-acquired wound. Single infestations were reported for S. haemorrhoidalis and L. eximia. Of the 39 clinical cases, 8 (21%) occurred in tourists. Ivermectin, when it became available, was used to treat furuncular, wound, and cavitary lesions successfully. MPH data for 2013–2015 registered 2,187 cases of which 54% were reported in men; 46% occurred in the tropical Pacific coast, 30% in the temperate Andes, 24% in the tropical Amazon, and 0.2% in the Galapagos Islands. The highest annual incidence was reported in the Amazon (23 cases/100,000 population), followed by Coast (5.1/100,000) and Andes (4.7/100,000). Human myiasis is a neglected and understudied ectoparasitic infestation, being endemic in both temperate and tropical regions of Ecuador. Improved education and awareness among populations living in, visitors to, and health personnel working in high-risk regions, is required for improved epidemiological surveillance, prevention, and correct diagnosis and treatment

    Comorbidities are Frequent in Patients with Gastroesophageal Reflux Disease in a Tertiary Health Care Hospital

    Get PDF
    INTRODUCTION: Several aspects of gastroesophageal reflux disease (GERD) have been studied, but the frequency of comorbidities is not yet fully understood. OBJECTIVES: To study the prevalence of GERD comorbidities in a tertiary care hospital. METHODS: We prospectively studied 670 consecutive adult patients from the outpatient department of our facility. A diagnosis was established using clinical, endoscopic and/or pHmetry-related findings. Each patient's medical file was reviewed with respect to the presence of other medical conditions and diagnoses. RESULTS: Of the 670 patients, 459 (68.6%) were female, and the mean age was 55.94 (17-80 years). We registered 316 patients (47.1%) with the erosive form of GERD and 354 patients (52.9%) with the non-erosive form. A total of 1,664 instances of comorbidities were recorded in 586 patients (87.5%), with the most common being arterial hypertension (21%), hypercholesterolemia (9%), obesity (9%), type II diabetes mellitus (5%) and depression (4%). Two or more comorbidities were present in 437 individuals (64.8%). The occurrence of comorbidities increased with age and was higher in patients with the non-erosive form of GERD. CONCLUSIONS: In a tertiary referral population, comorbidities were very common, and these may have worsened the already impaired health-related quality of life of these patients. Clinicians caring for GERD patients in this setting must be aware of the likelihood and nature of comorbid disorders and their impact on disease presentation and patient management

    Exchange policy credibility through the lens of the carry trade: The Mexican peso and the Brazilian real.

    Get PDF
    Exchange credibility is a valuable asset for currency policymakers. In this article we intend to analyse exchange credibility from the perspective of carry trade speculators. Global speculators' access to shadow banking financing allows them to build dynamic carry trade strategies that are a source of potential financial instability. Our view is that the existence of dynamic carry trade opportunities offers a tool for monitoring how market participants asses the credibility of exchange policies. We use the long term performance of different carry trade dynamic specifications to understand how different is the market view of exchange policy credibility in the case of two leading Latin America countries, Mexico and Brazil. Our empirical research covers data from May of 2000 to May 2018. In light of the evidence presented, we recognize that Mexican peso exchange policy is considered credible but Brazilian real exchange policy is not considered credible during the sample period

    Ultrasound and Microwave Assisted Extraction of Opuntia Fruit Peels Biocompounds: Optimization and Comparison Using RSM-CCD

    Get PDF
    [EN] Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of bioactive compounds, peels from Opuntia engelmannii cultivar (cv.) Valencia were optimized by response surface methodology. Randomized extraction runs were performed for each of the technologies employed in order to build effective models with maximum (bioactive molecules content and yield) and minimum (antioxidant activity) responses. A 5-level, 4-factor central composite design was used to obtain target responses as a function of extraction time (t), solid to liquid ratio (S/L), methanol concentration (metOH), and temperature (T). Specific response optimization for each technology was analyzed, discussed, and general optimization from all the responses together was also gather. The optimum values for each factor were: t = 2.5 and 1.4 min, S/L = 5 and 5 g/L, metOH = 34.6 and 0% of methanol and T = 30 and 36.6 °C, achieving maximum responses of 201.6 and 132.9 mg of betalains/g, 13.9 and 8.0 mg of phenolic acids/g, 2.4 and 1.5 mg of flavonoids/g, 71.8% and 79.1% of extractable solid and IC50 values for the antioxidant activity of 2.9 and 3.6, for UAE and MAE, respectively. The present study suggested UAE as the best extraction system, in order to maximize recovery of bioactive compounds with a high antioxidant activity.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programmer PT2020 for financial support to CIMO (UID/AGR/00690/2019) and L. Barros and M.I. Dias also thank the national funding by FCT, P.I., through the institutional scientific employment program-contract. The authors are grateful to CONACyT for supporting B. Melgar with his doctoral grant (No. 329930). The authors specially thanks to Maria Luisa Ruiz and the "Laboratorio Agroalimentario de la Comunitat Valenciana" for allow the use of the microwave for the extractions. This work is also funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural(R)Melgar-Castañeda, B.; Dias, MI.; Barros, L.; Ferreira, IC.; Rodríguez López, AD.; Garcia-Castello, EM. (2019). Ultrasound and Microwave Assisted Extraction of Opuntia Fruit Peels Biocompounds: Optimization and Comparison Using RSM-CCD. Molecules. 24(19):1-16. https://doi.org/10.3390/molecules24193618S1162419GVR Natural Antioxidants Market Analysis By Product (Vitamin C, Vitamin E, Polyphenols, Carotenoids) And Segment Forecasts To 2022https://www.grandviewresearch.com/industry-analysis/natural-antioxidants-marketThe Economics of Natural Color Pigmentshttps://sensientfoodcolors.com/en-us/research-development/economics-natural-color-pigments/Do Prado, D. Z., Capoville, B. L., Delgado, C. H. O., Heliodoro, J. C. A., Pivetta, M. R., Pereira, M. S., … Fleuri, L. F. (2018). Nutraceutical Food: Composition, Biosynthesis, Therapeutic Properties, and Applications. Alternative and Replacement Foods, 95-140. doi:10.1016/b978-0-12-811446-9.00004-6Aruwa, C. E., Amoo, S. O., & Kudanga, T. (2018). Opuntia (Cactaceae) plant compounds, biological activities and prospects – A comprehensive review. Food Research International, 112, 328-344. doi:10.1016/j.foodres.2018.06.047Cardoso-Ugarte, G. A., Sosa-Morales, M. E., Ballard, T., Liceaga, A., & San Martín-González, M. F. (2014). Microwave-assisted extraction of betalains from red beet (Beta vulgaris). LWT - Food Science and Technology, 59(1), 276-282. doi:10.1016/j.lwt.2014.05.025Garcia-Castello, E. M., Rodriguez-Lopez, A. D., Mayor, L., Ballesteros, R., Conidi, C., & Cassano, A. (2015). Optimization of conventional and ultrasound assisted extraction of flavonoids from grapefruit (Citrus paradisi L.) solid wastes. LWT - Food Science and Technology, 64(2), 1114-1122. doi:10.1016/j.lwt.2015.07.024Laqui-Vilca, C., Aguilar-Tuesta, S., Mamani-Navarro, W., Montaño-Bustamante, J., & Condezo-Hoyos, L. (2018). Ultrasound-assisted optimal extraction and thermal stability of betalains from colored quinoa (Chenopodium quinoa Willd) hulls. Industrial Crops and Products, 111, 606-614. doi:10.1016/j.indcrop.2017.11.034Thirugnanasambandham, K., & Sivakumar, V. (2017). Microwave assisted extraction process of betalain from dragon fruit and its antioxidant activities. Journal of the Saudi Society of Agricultural Sciences, 16(1), 41-48. doi:10.1016/j.jssas.2015.02.001Chemat, F., Vian, M. A., & Cravotto, G. (2012). Green Extraction of Natural Products: Concept and Principles. International Journal of Molecular Sciences, 13(7), 8615-8627. doi:10.3390/ijms13078615Barba, F. J., Puértolas, E., Brnčić, M., Panchev, I. N., Dimitrov, D. A., Athès-Dutour, V., … Souchon, I. (2015). Emerging extraction. Food Waste Recovery, 249-272. doi:10.1016/b978-0-12-800351-0.00011-0Melgar, B., Dias, M. I., Ciric, A., Sokovic, M., Garcia-Castello, E. M., Rodriguez-Lopez, A. D., … Ferreira, I. (2017). By-product recovery of Opuntia spp. peels: Betalainic and phenolic profiles and bioactive properties. Industrial Crops and Products, 107, 353-359. doi:10.1016/j.indcrop.2017.06.011Chougui, N., Djerroud, N., Naraoui, F., Hadjal, S., Aliane, K., Zeroual, B., & Larbat, R. (2015). Physicochemical properties and storage stability of margarine containing Opuntia ficus-indica peel extract as antioxidant. Food Chemistry, 173, 382-390. doi:10.1016/j.foodchem.2014.10.025Mena, P., Tassotti, M., Andreu, L., Nuncio-Jáuregui, N., Legua, P., Del Rio, D., & Hernández, F. (2018). Phytochemical characterization of different prickly pear (Opuntia ficus-indica (L.) Mill.) cultivars and botanical parts: UHPLC-ESI-MSn metabolomics profiles and their chemometric analysis. Food Research International, 108, 301-308. doi:10.1016/j.foodres.2018.03.062Yeddes, N., Chérif, J., Guyot, S., Sotin, H., & Ayadi, M. (2013). Comparative Study of Antioxidant Power, Polyphenols, Flavonoids and Betacyanins of the Peel and Pulp of Three Tunisian Opuntia Forms. Antioxidants, 2(2), 37-51. doi:10.3390/antiox2020037Allai, L., Druart, X., Öztürk, M., BenMoula, A., Nasser, B., & El Amiri, B. (2016). Protective effects of Opuntia ficus-indica extract on ram sperm quality, lipid peroxidation and DNA fragmentation during liquid storage. Animal Reproduction Science, 175, 1-9. doi:10.1016/j.anireprosci.2016.09.013Ammar, I., Ben Salem, M., Harrabi, B., Mzid, M., Bardaa, S., Sahnoun, Z., … Ennouri, M. (2018). Anti-inflammatory activity and phenolic composition of prickly pear ( Opuntia ficus-indica ) flowers. Industrial Crops and Products, 112, 313-319. doi:10.1016/j.indcrop.2017.12.028Betancourt, C., Cejudo-Bastante, M. J., Heredia, F. J., & Hurtado, N. (2017). Pigment composition and antioxidant capacity of betacyanins and betaxanthins fractions of Opuntia dillenii (Ker Gawl) Haw cactus fruit. Food Research International, 101, 173-179. doi:10.1016/j.foodres.2017.09.007Mata, A., Ferreira, J. P., Semedo, C., Serra, T., Duarte, C. M. M., & Bronze, M. R. (2016). Contribution to the characterization of Opuntia spp. juices by LC–DAD–ESI-MS/MS. Food Chemistry, 210, 558-565. doi:10.1016/j.foodchem.2016.04.033Melgar, B., Pereira, E., Oliveira, M. B. P. P., Garcia-Castello, E. M., Rodriguez-Lopez, A. D., Sokovic, M., … Ferreira, I. C. F. R. (2017). Extensive profiling of three varieties of Opuntia spp. fruit for innovative food ingredients. Food Research International, 101, 259-265. doi:10.1016/j.foodres.2017.09.024Fathordoobady, F., Mirhosseini, H., Selamat, J., & Manap, M. Y. A. (2016). Effect of solvent type and ratio on betacyanins and antioxidant activity of extracts from Hylocereus polyrhizus flesh and peel by supercritical fluid extraction and solvent extraction. Food Chemistry, 202, 70-80. doi:10.1016/j.foodchem.2016.01.121García-Cruz, L., Dueñas, M., Santos-Buelgas, C., Valle-Guadarrama, S., & Salinas-Moreno, Y. (2017). Betalains and phenolic compounds profiling and antioxidant capacity of pitaya ( Stenocereus spp.) fruit from two species ( S. Pruinosus and S. stellatus ). Food Chemistry, 234, 111-118. doi:10.1016/j.foodchem.2017.04.174Herbach, K. M., Stintzing, F. C., & Carle, R. (2005). Identification of heat-induced degradation products from purified betanin, phyllocactin and hylocerenin by high-performance liquid chromatography/electrospray ionization mass spectrometry. Rapid Communications in Mass Spectrometry, 19(18), 2603-2616. doi:10.1002/rcm.2103Spórna-Kucab, A., Ignatova, S., Garrard, I., & Wybraniec, S. (2013). Versatile solvent systems for the separation of betalains from processed Beta vulgaris L. juice using counter-current chromatography. Journal of Chromatography B, 941, 54-61. doi:10.1016/j.jchromb.2013.10.001Wybraniec, S., Starzak, K., Szneler, E., & Pietrzkowski, Z. (2016). Separation of chlorinated diastereomers of decarboxy-betacyanins in myeloperoxidase catalyzed chlorinated Beta vulgaris L. extract. Journal of Chromatography B, 1036-1037, 20-32. doi:10.1016/j.jchromb.2016.09.040Vinatoru, M. (2001). An overview of the ultrasonically assisted extraction of bioactive principles from herbs. Ultrasonics Sonochemistry, 8(3), 303-313. doi:10.1016/s1350-4177(01)00071-2Strack, D., Vogt, T., & Schliemann, W. (2003). Recent advances in betalain research. Phytochemistry, 62(3), 247-269. doi:10.1016/s0031-9422(02)00564-2Sawicki, T., & Wiczkowski, W. (2018). The effects of boiling and fermentation on betalain profiles and antioxidant capacities of red beetroot products. Food Chemistry, 259, 292-303. doi:10.1016/j.foodchem.2018.03.143Ravichandran, K., Saw, N. M. M. T., Mohdaly, A. A. A., Gabr, A. M. M., Kastell, A., Riedel, H., … Smetanska, I. (2013). Impact of processing of red beet on betalain content and antioxidant activity. Food Research International, 50(2), 670-675. doi:10.1016/j.foodres.2011.07.002Paciulli, M., Medina-Meza, I. G., Chiavaro, E., & Barbosa-Cánovas, G. V. (2016). Impact of thermal and high pressure processing on quality parameters of beetroot (Beta vulgaris L.). LWT - Food Science and Technology, 68, 98-104. doi:10.1016/j.lwt.2015.12.029Guldiken, B., Toydemir, G., Nur Memis, K., Okur, S., Boyacioglu, D., & Capanoglu, E. (2016). Home-Processed Red Beetroot (Beta vulgaris L.) Products: Changes in Antioxidant Properties and Bioaccessibility. International Journal of Molecular Sciences, 17(6), 858. doi:10.3390/ijms17060858Ferreres, F., Grosso, C., Gil-Izquierdo, A., Valentão, P., Mota, A. T., & Andrade, P. B. (2017). Optimization of the recovery of high-value compounds from pitaya fruit by-products using microwave-assisted extraction. Food Chemistry, 230, 463-474. doi:10.1016/j.foodchem.2017.03.061Al-Farsi, M. A., & Lee, C. Y. (2008). Optimization of phenolics and dietary fibre extraction from date seeds. Food Chemistry, 108(3), 977-985. doi:10.1016/j.foodchem.2007.12.009Primorac, T., Požar, M., Sokolić, F., Zoranić, L., & Urbic, T. (2018). A simple two dimensional model of methanol. Journal of Molecular Liquids, 262, 46-57. doi:10.1016/j.molliq.2018.04.055Bessada, S. M. F., Barreira, J. C. M., Barros, L., Ferreira, I. C. F. R., & Oliveira, M. B. P. P. (2016). Phenolic profile and antioxidant activity of Coleostephus myconis (L.) Rchb.f.: An underexploited and highly disseminated species. Industrial Crops and Products, 89, 45-51. doi:10.1016/j.indcrop.2016.04.065Roriz, C. L., Barros, L., Prieto, M. A., Morales, P., & Ferreira, I. C. F. R. (2017). Floral parts of Gomphrena globosa L. as a novel alternative source of betacyanins: Optimization of the extraction using response surface methodology. Food Chemistry, 229, 223-234. doi:10.1016/j.foodchem.2017.02.07

    2D magnetic domain wall ratchet: The limit of submicrometric holes

    Get PDF
    The study of ratchet and crossed-ratchet effects in magnetic domain wall motion through 2D arrays of asymmetric holes is extended in this article to the submicrometric limit in hole size (small size regime). Therefore, the gap has been closed between the 2D ratchets in the range of tens-of-micrometers (large size regime) and the small size regime 1D ratchets based on nanowires. The combination of Kerr microscopy, X-ray PhotoEmission Electron Microscopy and micromagnetic simulations has allowed a full magnetic characterisation of both the domain wall (DW) propagation process over the whole array and the local DW morphology and pinning at the holes. It is found that the 2D small size limit is driven by the interplay between DW elasticity and half vortex propagation along hole edges: as hole size becomes comparable to DW width, flat DW propagation modes are favoured over kinked DW propagation due to an enhancement of DW stiffness, and pinned DW segments adopt asymmetric configurations related with Néel DW chirality. Nevertheless, both ratchet and crossed-ratchet effects have been experimentally found, and we propose a new ratchet/inverted-ratchet effect in the submicrometric range driven by magnetic fields and electrical currents respectively

    Potential tradeoffs between ecosystem services related to food production in the brazilian chaco.

    Get PDF
    The impacts of human interference in the use and management of land, arouses the need to assess them, in order to bring out the importance of ecosystem services provided by the environment to support life and human well-being. Thus, the general objective of this study was to analyze possible tradeoffs in services (ES) related to agricultural production in Porto Murtinho, MS, which is part of the Brazilian Chaco. The Brazilian Chaco is a cradle of fauna and flora biodiversity, being considered the second largest forest area on the American continent and the largest dry tropical forest in South America, hence the importance of conducting studies in this area. The methodology consisted of three stages, starting with the classification of the ES and collecting secondary data, followed by the systematization and processing of the data, reaching the third and final step in which the possible tradeoffs of the ES were analyzed. The ES studied were: Maintaining populations and habitats in nurseries, Animals raised for nutritional purposes and Terrestrial plants cultivated for nutritional purposes (CICES classification). Secondary data on forest from MapBiomas and stocking rate of cattle and agricultural productivity (PPM/PAM-IBGE) were used. This work aimed to alert decision makers to possible tradeoffs that are taking place in the Brazilian Chaco region, as the data point to a reduction in the area of natural forests and a significant increase in agricultural production indicators
    corecore