340 research outputs found

    NIRS potential use for the determination of natural resources quality from dehesa (acorn and grass) in Montanera system for Iberian pigs.

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    NIRS technology has been used as an alternative to conventional methods to determinate the content of nutrients of acorns and grass from dehesa ecosystem. Dry matter (DM), crude fat (CF), crude protein (CP), starch, total phenolic compounds (TP), α-tocopherol, γ-tocopherol, fatty acids, neutral detergent fiber (NDF), total antioxidant activity (TAA) and total energy (TE) were determined by conventional methods for later development of NIRS predictive equations. The NIR spectrum of each sample was collected and for all studied parameters, a predictive model was obtained and external validated. Good prediction equations were obtained for moisture, crude fat, crude protein, total energy and γ-tocopherol in acorns samples, with high coefficients of correlation (1-VR) and low standard error of prediction (SEP) (1-VR=0.81, SEP=2.62; 1-VR=0.92, SEP=0.54; 1-VR=0.86, SEP=0.47; 1-VR=0.84, SEP=0.2; 1-VR=0.88, SEP=5.4, respectively) and crude protein, NDF, α-tocopherol and linolenic acid content in grass samples (1-VR=0.9, SEP=1.99; 1-VR=0.87, SEP=4.13; 1-VR=0.76, SEP=10.9; 1-VR=0.82, SEP=0.6, respectively). Therefore, these prediction models could be used to determinate the nutritional composition of Montanera natural resources

    Field enhancement and spectral features of hexagonal necklaces of silver nanoparticles for enhanced nonlinear optical processes

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    Access to the online abstract in the journal: https://doi.org/10.1364/OE.26.022394 © 2018 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reservedThe nonlinear properties of hybrid metallic-dielectric systems are attracting great interest due to their potential for the enhancement of frequency conversion processes at nanoscale dimensions. In this work, we theoretically and experimentally address the correlation between the near field distribution of hexagonal plasmonic necklaces of silver nanoparticles formed on the surface of a LiNbO3 crystal and the second harmonic generation (SHG) produced by this nonlinear crystal in the vicinities of the necklaces. The spectral response of the hexagonal necklaces does not depend on the polarization direction and is characterized by two main modes, the absorptive high-energy mode located in the UV spectral region and the lower energy mode, which is strongly radiant and extends from the visible to the near infrared region. We show that the spatial distribution of the enhanced SHG is consistent with the local field related to the low energy plasmon mode, which spectrally overlaps the fundamental beam. The results are in agreement with the low absorption losses of this mode and the two-photon character of the nonlinear process and provide deeper insight in the connection between the linear and nonlinear optical properties of the hybrid plasmonic-ferroelectric system. The study also highlights the potential of hexagonal necklaces as useful plasmonic platforms for enhanced optical processes at the nanoscaleSpanish Ministry of Economy and Competitiveness (MINECO) under project MAT2016- 76106-R and the Comunidad de Madrid (grant S2013/MIT-2740). C.T. acknowledges funding from the VILLUM Foundation (Villum Investigator, grant no. 16498). L.E.B and M.O.R also acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through The “MarĂ­a de Maeztu” Programme for Units of Excellence in R&D (MDM-2014-0377

    Enhancing nonlinear interactions by the superposition of plasmonic lattices on ꭕ(2)-nonlinear photonic crystals

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    Plasmonic structures have been revealed as efficient units to enhance localized nonlinear phenomena generated at dielectric-metal interfaces. However, their effect on the nonlinear interactions provided by quasi-phase matching processes in ꭕ(2) modulated dielectric crystals have been scarcely addressed, mainly due to the complexity in manufacturing appropriate periodic plasmonic structures overlying the ꭕ(2) dielectric structure. Here, by a simple method we have fabricated a periodic structure based on the combination of two commensurate lattices: a periodic lattice of chains of Ag nanoparticles and a periodic lattice of ꭕ(2)-modulation based on a ferroelectric domains structure. The hybrid system supports multiple surface plasmon lattice resonances (SLRs) at the technologically relevant NIR spectral region, which yield the enhancement of the nonlinear diffraction pattern generated by the ꭕ(2) structure. The superposition of the plasmonic and the ꭕ(2)-modulation lattice results in a 20-fold enhancement of the directional SHG due to the excitation of SLRs by the interacting waves involved in the nonlinear process. The results are obtained in lithium niobate, a widely used crystal in optoelectronics, and demonstrate the potential of the approach to design integrated solid-state platforms for on-chip optical steering, multiplexing or quantum technologiesThis work has been supported by the Spanish Government (Contracts MAT2016-76106-R and PID2019-108257GB-I00/ AEI/10.13039/501100011033 and MarĂ­a de Maeztu “Pro gramme for Units of Excellence in R&D CEX2018-000805-M) and Comunidad de Madrid (Grant SI1/PJI/2019-00105

    Animal Board Invited Review: Sheep birth distribution in past herds: a review for prehistoric Europe (6th to 3rd millennia BC)

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    In temperate latitudes sheep have a seasonal reproductive behaviour, which imposes strong constraints on husbandry in terms of work organization and availability of animal products. During the last 50 years, researchers have focused on understanding the mechanisms driving small ruminants’ reproduction cycles and finding ways to control them. This characteristic is inherited from their wild ancestor. However, the history of its evolution over the 10 millennia that separates present day European sheep from their Near Eastern ancestors’ remains to be written. This perspective echoes archaeologists’ current attempts at reconstructing ancient pastoral societies’ socio-economical organization. Information related to birth seasonality may be retrieved directly from archaeological sheep teeth. The methodology consists of reconstructing the seasonal cycle record in sheep molars, through sequential analysis of the stable oxygen isotope composition (ή 18O) of enamel. Because the timing of tooth development is fixed within a species, inter-individual variability in this parameter reflects birth seasonality. A review of the data obtained from 10 European archaeological sites dated from the 6th to the 3rd millennia BC is provided. The results demonstrate a restricted breeding season for sheep: births occurred over a period of 3 to 4 months, from late winter to early summer at latitudes 43°N to 48°N, while a later onset was observed at a higher latitude (59°N). All conclusions concurred with currently held expectations based on present day sheep physiology, which, aside from the historical significance, contributes to the reinforcing of the methodological basis of the approach. Further study in this area will permit regional variability attributable to technical choices, within global schemes, to be fully reported

    Spanish study of anticoagulation in haemodialysis

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    This study's objectives were to determine which anticoagulation methods are commonly used in patients who are undergoing haemodialysis (HD) in Spain, on what criteria do they depend, and the consequences arising from their use. MATERIAL AND METHOD: Ours was a cross-sectional study based on two types of surveys: a "HD Centre Survey" and a "Patient Survey". The first survey was answered by 87 adult HD units serving a total of 6093 patients, as well as 2 paediatric units. Among these units, 48.3% were part of the public health system and the remaining 51.7% units were part of the private health system. The patient survey analysed 758 patients who were chosen at random from among the aforementioned 78 HD units. RESULTs: A) HD Centre Survey: The majority of adult HD units (n=61, 70.2%) used both kinds of heparin, 19 of them (21.8%) only used LMWH and 7 of them (8%) only used UFH. The most frequently applied criteria for the use of LMWH were medical indications (83.3% of HD units) and ease of administration (29.5%). The most frequently used methods for adjusting the dosage were clotting of the circuit (88.2% of units), bleeding of the vascular access after disconnection (75.3%), and patient weight (57.6%). B) Patient Survey: The distribution of the types of heparin used was: UFH: 44.1%, LMWH: 51.5%, and dialysis without heparin in 4.4% of patients. LMWH was more frequently used in public medical centres (64.2% of patients) than in private medical centres (46.1%) (P<.001). LMWH was more frequently used in on-line haemodiafiltration (HF) than in high-flux HD (P<.001). Antiplatelet agents were given to 45.5% of patients, oral anticoagulants to 18.4% of patients, and both to 5% of patients. Additionally, 4.4% of patients had suffered bleeding complications during the previous week, and 1.9% of patients suffered thrombotic complications. Bleeding complications were more frequent in patients with oral anticoagulants (P=.001), although there was no association between the type of heparin and the occurrence of bleeding or thrombotic complications. CONCLUSIONS: We are able to conclude that there is a great amount of disparity in the criteria used for the medical prescription of anticoagulation in HD. It is advisable that each HD unit revise their own results as well as those from other centres, and possibly to create an Anticoagulation Guide in Haemodialysis

    KLIC-score for predicting early failure in prosthetic joint infections treated with debridement, implant retention and antibiotics

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    AbstractDebridement, irrigation and antibiotic treatment form the current approach in early prosthetic joint infection (PJI). Our aim was to design a score to predict patients with a higher risk of failure. From 1999 to 2014 early PJIs were prospectively collected and retrospectively reviewed. The primary end-point was early failure defined as: 1) the need for unscheduled surgery, 2) death-related infection within the first 60 days after debridement or 3) the need for suppressive antibiotic treatment. A score was built-up according to the logistic regression coefficients of variables available before debridement. A total of 222 patients met the inclusion criteria. The most frequently isolated microorganisms were coagulase-negative staphylococci (95 cases, 42.8%) and Staphylococcus aureus (81 cases, 36.5%). Treatment of 52 (23.4%) cases failed. Independent predictors of failure were: chronic renal failure (OR 5.92, 95% CI 1.47–23.85), liver cirrhosis (OR 4.46, 95% CI 1.15–17.24), revision surgery (OR 4.34, 95% CI 1.34–14.04) or femoral neck fracture (OR 4.39, 95% CI1.16–16.62) compared with primary arthroplasty, C reactive protein >11.5 mg/dL (OR 12.308, 95% CI 4.56–33.19), cemented prosthesis (OR 8.71, 95% CI 1.95–38.97) and when all intraoperative cultures were positive (OR 6.30, 95% CI 1.84–21.53). A score for predicting the risk of failure was designed using preoperative factors (KLIC-score: Kidney, Liver, Index surgery, Cemented prosthesis and C-reactive protein value) and it ranged between 0 and 9.5 points. Patients with scores of ≀2, >2–3.5, 4–5, >5–6.5 and ≄7 had failure rates of 4.5%, 19.4%, 55%, 71.4% and 100%, respectively. The KLIC-score was highly predictive of early failure after debridement. In the future, it would be necessary to validate our score using cohorts from other institutions
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