Curvature-induced stabilization and field-driven dynamics of magnetic hopfions in toroidal nanorings.

Three dimensional magnetic textures are a cornerstone in magnetism research. In this work, we analyze the stabilization and dynamic response of a magnetic hopfion hosted in a toroidal nanoring with intrinsic Dzyaloshinskii-Moriya interaction simulating FeGe. Our results evidence that unlike their planar counterparts, where perpendicular magnetic anisotropies are necessary to stabilize hopfions, the shape anisotropy originated on the torus symmetry naturally yields the nucleation of these topological textures. We also analyze the magnetization dynamical response by applying a magnetic field pulse to differentiate among several magnetic patterns. Finally, to understand the nature of spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases and describe the differences among bulk and surface modes. Importantly, hopfions lying in toroidal nanorings present a non-circularly symmetric poloidal resonant mode, which is not observed in other systems hosting hopfions.

Observation of a Near-Threshold Proton Resonance in

A near-threshold proton resonance in ^{11}B at E_{ex}=11.44±0.04 MeV is observed via the reaction ^{10}Be(d,n)^{11}Be→^{10}Be+p in inverse kinematics, measured with a beam of the radioactive isotope ^{10}Be. The resonance energy at E_{res}=211(40) keV is consistent with a proton signal observed by Ayyad et al. in the ß-delayed proton decay of ^{11}Be. By comparison to a distorted wave Born approximation calculation, a 0.27(6) spectroscopic factor is extracted and a tentative (ℓ=0) character is assigned for this resonance. The significant cross section in the proton-transfer (d,n) reaction, as well as the observation of its proton-decay signal, point to the threshold-resonance character of this state. The position of this state, its structure, and strong coupling to the s-wave continuum represent an ideal case to study quantum near-threshold many-body dynamics of unstable states. The presence of this state is an important step toward understanding the excessively large beta-delayed proton-decay branch of ^{11}Be.

Magnonic key based on skyrmion clusters.

In this work, we report the excitation of spin-waves modes in skyrmion clusters hosted in Co/Pt nanodots by applying an in-plane magnetic field pulse. The direction at which the magnetic field is applied enables the excitation of five main spin-waves modes that are understood in terms of only azimuthal-like modes, which are shown to be strongly dependent on the number of skyrmions stabilized in the system. This feature converts the present system in a mechanism to activate and suppress a set of given modes, which in turn we propose to be utilized as a magnonic key based skyrmion cluster. Our results could be useful in manufacturing potential magnonic logic devices based in skyrmionic textures.

Effect of nonuniform perpendicular anisotropy in ferromagnetic resonance spectra in magnetic nanorings.

The high frequency dynamic behaviors of magnetic nanorings with variable anisotropy along their radius have been studied using micromagnetic simulations. The dynamic susceptibility spectrum and spatial localization of the ferromagnetic resonance modes are investigated by varying anisotropy gradients in nanorings of 200 nm of external radius, with different internal radii. Both the resonant frequencies and the number of peaks depend on the lower energy magnetization configuration which in turn is a function of anisotropy gradients. Besides, it is shown that the effects of the anisotropy gradient are relevant even for the narrowest ring of 10 nm wide. The idea of controlling frequencies by modifying the anisotropy gradients of the system suggests the possibility of using these nanostructures in potential magnetic controllable frequency devices.

Dynamic and static properties of stadium-shaped antidot arrays.

In this work we performed a detailed numerical analysis on the static and dynamic properties of magnetic antidot arrays as a function of their geometry. In particular, we explored how by varying the shape of these antidot arrays from circular holes to stadium-shaped holes, we can effectively control the magnetic properties of the array. Using micromagnetic simulations we evidenced that coercivity is very sensitive to the shape of antidots, while the remanence is more robust to these changes. Furthermore, we studied the dynamic susceptibility of these systems, finding that it is possible to control both the position and the number of resonance peaks simply by changing the geometry of the holes. Thus, this work provides useful insights on the behavior of antidot arrays for different geometries, opening routes for the design and improvement of two-dimensional technologies.

[Adequacy of treatment with ertapenem according to the criterion approved for the infection´s commission of a specialty hospital]. / Adecuación del tratamiento con ertapenem según los criterios aprobados por la comisión de infecciones de un hospital de especialidades.

OBJECTIVE: The inappropriate use of antibiotics in our environment increases the risk of multi-resistant bacteria, therefore it is necessary to present studies to meet and promote the proper use of antimicrobial. METHODS: Retrospective observational study in which patients who are receiving ertapenem during the period of stady (5 ½ months), were included. The adequacy of the indication to the conditions of use agreed in the Hospital was evaluated and the evolution of the treatment was monitored until the end, determining the degree of therapeutic de-escalation. RESULTS: 84 ertapenem prescriptions were included. The vast mayority of the prescriptions were carried out by Internal Medicine (41.7%) and the main indication was urinary tract infection (47.2%). Microbiological cultures were requested in the 75% of the patients before the first dose of ertapenem. The prescription was adapted in 69 (82.14%) of ertapenem patients to the criteria approved by the Hospital. Regarding the evolution of antibiotic therapy, treatment with ertapenem continued until resolution of the infection in 58.33% of patients. In 15 of 23 (66.21%) patients with the possibility of therapeutic de-escalation it was performed after 2-3 days of empirical treatment. CONCLUSIONS: The vast majority of treatments ertapenem fit the criteria of prescription our Hospital. The high percentage of patients with microbiological results available, allowed in many patients the appropriate adjustment of the treatment in the first 72 hours.

Effects on the metabolism, growth, digestive capacity and osmoregulation of juvenile of Sub-Antarctic Notothenioid fish Eleginops maclovinus acclimated at different salinities.

In this study we assessed the influence of three different environmental salinities (5, 15 and 31 psu during 90 days) on growth, osmoregulation, energy metabolism and digestive capacity in juveniles of the Notothenioid fish Eleginops maclovinus. At the end of experimental time samples of plasma, liver, gill, intestine, kidney, skeletal muscle, stomach and pyloric caeca were obtained. Growth, weight gain, hepatosomatic index and specific growth rate increased at 15 and 31 psu and were lower at 5 psu salinity. Gill Na(+), K(+)-ATPase (NKA) activity presented a "U-shaped" relationship respect to salinity, with its minimum rates at 15 psu, while this activity correlated negatively with salinity at both anterior and posterior intestinal portions. No significant changes in NKA activity were observed in kidney or mid intestine. Large changes in plasma, metabolite levels and enzymatic activities related to energy metabolism in liver, gill, intestine, kidney and muscle were generally found in the groups exposed to 5 and 31 psu compared to the 15 psu group. Only the pepsin activity (digestive enzymes) assessed enhanced with environmental salinity, while pyloric caeca trypsin/chymotrypsin ratio decreased. This study suggests that juvenile of E. maclovinus presents greater growth near its iso-osmotic point (15 psu) and hyperosmotic environment (31 psu). Acclimation to low salinity increased the osmoregulatory expenditure as seen by the gill and anterior intestine results, while at high salinity, branchial osmoregulatory activity was also enhanced. This requires the mobilization of lipid stores and amino acids, thereby holding the growth of fish back. The subsequent reallocation of energy sources was not sufficient to maintain the growth rate of fish exposed to 5 psu. Thus, E. maclovinus juveniles present better growth efficiencies in salinities above the iso-osmotic point and hyperosmotic environment of this species, showing their best performance at 15 psu as seen by the main osmoregulatory and energy metabolism enzymatic activities.

Stocking density and Piscirickettsia salmonis infection effect on Patagonian blennie (Eleginops maclovinus, Cuvier 1830) skeletal muscle intermediate metabolism.

The need to expand aquaculture production has led to other fish to be considered as potential species for culture, such as the sub-Antarctic notothenioid Eleginops maclovinus (Valenciennes, 1830). The aim of this study was to determine the cumulative effect of density and pathogen infection by protein extract of Piscirickettsia salmonis on skeletal muscle metabolism. In a first experiment, specimens were submitted to three different stocking densities: (1) 3.1 kg m(-3), (2) 15 kg m(-3) and (3) 60 kg m(-3), for a period of 10 days. In a second experiment, metabolic changes caused by an infection of P. salmonis protein extract (a single injection of 0.5 µL P. salmonis protein extract g body weight(-1) was inoculated in the fish) and its combined effect with stocking density was assessed during a period of 10 days. This study concludes that stress caused by high stocking density led to the reorganization of some metabolic routes to fulfill skeletal muscle energy needs. Furthermore, infection response by pathogen P. salmonis differed when stocking density increased, suggesting an increase of energy needs with density in skeletal muscle of infected fish.

[Ultrasound diagnosis of pulmonary infarction in emergencies. A case presentation]. / Diagnóstico ecográfico del infarto pulmonar en urgencias. A propósito de un caso.

Pulmonary infarction is a parenchymal ischemic lesion that occurs in the context of a pulmonary embolism when arterial blockage deprives perfusion to that area and the adjacent bronchial circulation does not provide the necessary flow. It appears in approximately 40% of pulmonary embolisms. Emergency Physicians are able to diagnose a pulmonary infraction at the patient bedside, in a quick, easy, safe and efficient way with the availability of ultrasound in our Emergency Rooms and Health Centres. The possibility of approaching the aetiology, firstly with a clinical suspicion then adding risk factors, symptoms, clinical and radiological signs and the use of in situ imaging, increases the sensitivity and specificity of the diagnosis.

[Modification of empirical antimicrobial regimen during the first 72 hours of hospitalisation]. / Modificación del tratamiento antibiótico empírico en las primeras 72 horas de hospitalización.

OBJECTIVE: The aims of this study were to determine the empirical antibiotic therapy used in patients admitted to the Emergency Department who were later hospitalised, and to describe the antibiotic changes during their first days of hospitalisation. METHOD: All 14-year-old patients admitted to the Emergency Department who were started on antibiotic therapy and subsequently were hospitalised for at least 72 hours in an in-patient hospital ward, were included in a prospective observational study. Patients underwent daily follow-up during the first three days of hospitalisation. The type of infection, microbiological data and empirical antibiotic therapy and its changes were registered. RESULTS: 225 patients were included in this study. The most frequent types of infection diagnosed were infection of the respiratory airways, pneumonia and skin and soft-tissue infection. Amoxicillin-clavulanic acid was the most widely prescribed antibiotic followed by levofloxacin and third generation cephalosporins. Microbiological samples were taken in 80 (36%) patients. Of the 225 antimicrobial regimens started in the Emergency Department, 94 (42%) were changed during the first 72 hours of hospitalisation: 37 (16%) were completely modified, 31 (14%) were discontinued and antibiotics were added or stopped from the existing regimen in 26 cases (12%). Among these 94 patients whose treatment was changed, only in 40 (42%) there was a microbiological result for aiding in the adjustment of the antibiotic therapy. CONCLUSION: The frequency of early changes during inpatient hospitalisation to antimicrobial regimens which were initially prescribed in the Emergency Department is high. Microbiological results were rarely used to guide these changes.

Entamoeba histolytica: ADP-ribosylation of secreted glyceraldehyde-3-phosphate dehydrogenase.

In addition to its classic glycolytic role, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been implicated in many activities unrelated to glycolysis, such as membrane fusion, binding to host proteins and signal transduction. GAPDH can be the target of several modifications that allow incorporation to membranes and possible regulation of its activity; among these modifications is mono-ADP-ribosylation. This post-translational modification is important for the regulation of many cellular processes and is the mechanism of action of several bacterial toxins. In a previous study, we observed the extracellular ADP-ribosylation of a 37-kDa ameba protein. We report here that GAPDH and cysteine synthase A are the main ADP-ribosylated proteins in Entamoeba histolytica extracellular medium, GAPDH is secreted from ameba at 37 degrees C in a time-dependent manner, and its enzymatic activity is not inhibited by ADP-ribosylation. Extracellular GAPDH from ameba may play an important role in the survival of this human pathogen or in interaction with host molecules, as occurs in other organisms.

Electrical safety priority index for medical equipment.

Due to the wide variety of equipment existing in clinical areas, there is an important question: which and how often electrical safety tests most be applied to the medical equipment. There are important differences about the electrical safety, such as the electrical insulation or the hazard considering the connection between patient and electrical instrumentation. The objective of this work was to develop an Electrical Safety Priority Index for Medical Equipment(ESPIME) involving different classifications related with electrical safety, in order to provide a numeric code indicating the priority and frequency for applying the electrical safety tests to medical equipment. The index were applied to the medical equipment in critical care locations and the result,were used to defined which set of medical equipment would be the first for developing and applying electrical safety tests in a private hospital in Mexico City.

[An analisys fo causes for the discontinuation of a simplified antiretroviral regimen with abacavir, lamivudine and zidovudine]. / Análisis de las causas de suspensión del régimen antirretroviral simplificado abacavir, lamivudina y zidovudina.

OBJECTIVE: To identify and analyze the most common causes for the discontinuation of antiretroviral therapy, including the co-formulation of abacavir, lamivudine and zidovudine (ABC-3TC-AZT). METHOD: An observational, retrospective study was carried out on patients receiving antiretroviral therapy with ABC-3TC-AZT seen in the Pharmacy Department s outpatient unit from February 2002 through June 2004. The causes for discontinuation among patients withdrawing from this therapy were analyzed. Adherence was assessed using computerized dispensation records. A Kaplan-Meier survival analysis was designed in order to identify factors predictive of discontinuation. RESULTS: In all, 114 patients (85 males, 74.6%) received this therapy - 25.4% of them were naïve patients - and 34.2% (39/114) withdrew from this regimen, amongst them 44.8% (13/29) of naïve subjects. In 92.3% of cases this happened before treatment week 48. Discontinuation causes included: adverse reactions (46.1%), voluntary discontinuation (33.3%), clinical decision (15.4%), and other reasons (5.1%). A possible hypersensitivity reaction to ABC was reported for 9 patients. A greater likelihood of discontinuation was associated with detectable viral load at therapy onset, ex-parenteral drug abuser status, and naïve status (p < 0.05). CONCLUSIONS: A high percentage of discontinuations due to adverse events and voluntary withdrawal was found, particularly early during treatment. Patients who may therapeutically benefit from this regimen, particularly naïve subjects, should be identified, and interventions to improve adherence and optimize recovery parameters should be implemented.

In vitro activity of moxifloxacin compared to other antimicrobials against streptococci isolated from iatrogenic oral bacteremia in Spain.

BACKGROUND/AIMS: Systemic dissemination of oral bacteria to distant body sites may be the cause of focal infections. The unsuitable use and overexposure to antimicrobial therapy in clinical dental practice may contribute to the worldwide problem of antimicrobial resistance. The aim of this study was to determine the susceptibilities of streptococci isolated from the bloodstream after dental extractions against penicillin, ampicillin, amoxicillin, erythromycin, clindamycin, and a new fluoroquinolone, moxifloxacin. PATIENTS AND METHODS: Eighty-four patients who required dental extractions were studied. Venous blood samples were collected from each patient at baseline (before dental manipulation) and 30 s after dental extractions. The samples were processed in the Bactec 9240. The isolated bacteria were identified by conventional microbiological techniques. The antimicrobial susceptibility of 81 streptococci was determined by the E-test method. The NCCLS performance standards were followed. RESULTS: 88.9-92.5% of the streptococci were sensitive to beta-lactam agents tested with a minimum inhibitory concentration (MIC)(90s) ranging from 0.094 to 0.19 mg/l. The resistance to erythromycin and clindamycin was 40.8% (MIC(90HR) = 256 mg/l) and 21% (MIC(90HR) = 256 mg/l), respectively. The MIC(90) to moxifloxacin was 0.125 mg/l. CONCLUSION: Most of the streptococci isolated from the bloodstream after dental extractions were susceptible in vitro to penicillin, ampicillin, and amoxicillin. The high percentage of streptococci resistant to erythromycin and clindamycin could restrict their usefulness as prophylactic drugs. All the isolates showed a low MIC of moxifloxacin in vitro, making it a promising antimicrobial alternative for the prevention of streptococcal focal infections associated with certain dental manipulations, when the administration of beta-lactam agents is not indicated.

[A study of erythropoietin use for myelodysplastic syndrome]. / Estudio de utilización de eritropoyetina en el síndrome mielodisplásico.

OBJECTIVES: To assess the effectiveness of erythropoietin (EPO) and to study the extent of application of published recommendations for use in treating anemia in patients with myelodysplastic syndrome (MDS). MATERIALS AND METHODS: An observational retrospective study of patients with MDS receiving at least one dose of EPO. Patients were selected from the outpatient database at the Pharmacy Department, and the medical history as well as both clinical and pharmacotherapeutic data were collected. The clinical effectiveness of EPO was assessed at 6, 12, 16 and 24 weeks after treatment using two distinct criteria for erythroid response. Three items were defined and assessed for each patient in order to establish the extent of application of published recommendations on the efficient use of EPO. RESULTS: Eleven patients were enrolled. Three of them responded to EPO at some point during follow-up, according to pre-defined criteria. All three items used in the assessment of the efficient use of EPO showed significantly high inadequacy rates. CONCLUSIONS: In our study, the effectiveness of EPO in the management of MDS-related anemia is similar to that described in the literature. However, upon the assessment of its use in our hospital, this drug was shown not to have been employed according to published recommendations, which promote its cost-effective use. We believe that the cooperation of the Pharmacy Department in the design of a protocol for EPO use in MDS is of interest, and would contribute to EPO's efficient use.

[Classical phenylketonuria. Metabolism inborn errors]. / PKU clásica. Errores congénitos del metabolismo.

The authors describe pku or phenylketonuria, a congenital type of metabolic alteration which forces those patients who suffer it to follow a dietetic treatment for their entire lives. The authors analyze 1, the biochemical alterations which are produced in the organism and which cause the appearance of them; 2, the genetics involved; 3, the clinical manifestations shown by those who suffer from pku; 4, the diagnosis of this disease; 5, the number of cases in the general public; 6, a bit more extensive section dealing with the nutritional treatment, follow-up and control of this disease; 7, nursing care, fundamentally based on how to educate and counsel patients and their families regarding control methods and problems which commonly occur in dietetic treatment over the course of the various phases in one's life; and 8, the conclusions of this study, whose origin came after intensive contact with the Galician Association of Phenylketonuria and a study of the epidemiological and nutritional situation of sufferers of this disease in Galicia. This study was presented at the Third National "SENC" Congress held in Las Palmas de Gran Canaria.

Effect of plant lectins on Ustilago maydis in vitro.

Ustilago maydis is an edible parasitic basidiomycete, which specifically infects corn (Zea mays) and teocintle (Z. diploperennis). To characterise the interaction between the basidiomycete and its host organism, we tested the effect of plant lectins with well-known sugar specificity on the growth and germination of U. maydis spores. Lectins specific for N-acetyl-D-galactosamine, such as those from Dolichos biflorus and Phaseolus lunatus, and the wheatgerm agglutinin specific for N-acetyl-D-glucosamine inhibited spore germination, but were ineffective in modifying U. maydis cell growth. The galactose-specific lectin from the corn coleoptyle inhibited both germination and cell growth, while the lectin concanavalin A (mannose/glucose specific) activated spore germination and growth. Our results suggest that specific saccharide-containing receptors participate in regulating the growth and maturation of U. maydis spores.