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3.
Nanotechnology ; 27(6): 065303, 2016 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-26759183

RESUMEN

Functional nanostructures fabricated by focused electron/ion beam induced processing (FEBIP/FIBIP) open a promising route for applications in nanoelectronics. Such developments rely on the exploration of new advanced materials. We report here the successful fabrication of nickel-based deposits by FEBIP/FIBIP using bis(methyl cyclopentadienyl)nickel as a precursor. In particular, binary compounds such as nickel oxide (NiO) are synthesized by using an in situ two-step process at room temperature. By this method, as-grown Ni deposits transform into homogeneous NiO deposits using focused electron beam irradiation under O2 flux. This procedure is effective in producing highly pure NiO deposits with resistivity of 2000 Ωcm and a polycrystalline structure with face-centred cubic lattice and grains of 5 nm. We demonstrate that systems based on NiO deposits displaying resistance switching and an exchange-bias effect could be grown by FEBIP using optimized parameters. Our results provide a breakthrough towards using these techniques for the fabrication of functional nanodevices.

4.
Rev Gastroenterol Mex ; 79(1): 13-21, 2014.
Artículo en Español | MEDLINE | ID: mdl-24656515

RESUMEN

OBJECTIVES: To evaluate total serum calcium (TC) and albumin-corrected calcium (ACC) as prognostic severity factors in acute pancreatitis (AP). METHODS: Ninety-six patients were included in the study. They were diagnosed with AP and admitted to the Hospital Regional de Veracruz within the time frame of January 2010 to December 2012. AP severity was determined through the updated Atlanta Classification (2013). TC and ACC values were measured in the first 24hours of admittance and the percentages of sensitivity (S), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were calculated through ROC curves and contingency tables. RESULTS: In accordance with the updated Atlanta Classification, 70 patients presented with mild AP, 17 with moderately severe AP, and 9 with severe AP. Of the patient total, 61.5% were women, and 69.8% presented with biliary etiology. The maximum TC cut-off point was 7.5mg/dL, with values of S, 67%; Sp, 82%; PPV, 27%, and NPV, 96%. The maximum ACC cut-off point was 7.5mg/dL, with values of S, 67%; Sp, 90%; PPV, 40%; NPV, 96%. Both had values similar to those of the Ranson and APACHE II prognostic scales. CONCLUSIONS: TC and ACC, measured within the first 24hours, are useful severity predictors in acute pancreatitis, with sensitivity and predictive values comparable or superior to those of the conventional prognostic scales.


Asunto(s)
Calcio/sangre , Pancreatitis/sangre , Pancreatitis/diagnóstico , APACHE , Enfermedad Aguda , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/diagnóstico , Dolor/etiología , Valor Predictivo de las Pruebas , Pronóstico , Albúmina Sérica/química , Adulto Joven
5.
Nanotechnology ; 24(34): 345703, 2013 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-23899474

RESUMEN

Applications based on the movement of domain walls (DWs) in magnetic nanowires (NWs) require a good DW conduit behavior, i.e. a significant difference between DW nucleation and propagation fields. In this work, we have systematically studied how this property evolves in cobalt NWs grown by focused electron beam induced deposition (FEBID) as a function of global gallium irradiation, for irradiation doses up to 1.24 × 10(17) ions cm(-2). Whereas for high doses the DW conduit is lost, below 6.42 × 10(15) ions cm(-2) the difference between the two fields increases with irradiation, becoming up to ∼9 times larger than for non-irradiated wires, due to a strong increase in the nucleation field, while the propagation field remains approximately constant. This behavior stems from two effects. The first effect is a decrease in the magnetic volume of the parasitic halo around the NW, typically present in FEBID nanostructures, leading to the disappearance of weak nucleation centers. The second effect is the formation of a 20 nm outer shell with Co crystals about twice the size of those forming the NW core, causing a net increase of the local magnetocrystalline anisotropy. The results presented here are important for the potential use of magnetic NWs grown by FEBID in DW-based devices, and might also be of interest for magnetic NWs fabricated by other techniques.

6.
Nanotechnology ; 23(10): 105703, 2012 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-22361492

RESUMEN

Scanning transmission x-ray microscopy (STXM) and magnetoresistance (MR) measurements are used to investigate the magnetic behavior of a nanoconstriction joining two micrometric electrodes (a pad and a wire). The reversal of the magnetization under variable external static magnetic fields is imaged. By means of a detailed analysis of the STXM images at the nanocontact area, the MR is calculated, based on diffusive anisotropic-MR. This MR agrees well with that obtained from electrical transport measurements, allowing a direct correlation between the MR signal and the magnetic reversal of the system. The magnetization behavior depends on the sample thickness and constriction dimensions. In 40 nm-thick samples, with 20 × 175 nm(2) contact areas, the magnetization at the two sides of the constriction forms a net angle of 90°, with a progressive evolution of the magnetization structure between the electrodes during switching. The MR in those cases has a more peaked shape than with 20 nm-thick electrodes and 10 × 80 nm(2) contact areas, where the magnetization forms 180° between them, with a wide domain wall pinned at the constriction. As a consequence of this configuration, a plateau in the MR is observed for about 20 Oe.

7.
Phys Rev Lett ; 106(7): 077001, 2011 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-21405532

RESUMEN

We study the behavior of bundles of superconducting vortices when increasing the magnetic field using scanning tunneling microscopy and spectroscopy at 100 mK. Pinning centers are given by features on the surface corrugation. We find strong net vortex motion in a bundle towards a well-defined direction. We observe continuous changes of the vortex arrangements, and identify small displacements, which stress and deform the vortex bundle, separated by larger rearrangements or avalanches, which release accumulated stress.

8.
Nanotechnology ; 22(26): 265304, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21586811

RESUMEN

Titanium is a relevant technological material due to its extraordinary mechanical and biocompatible properties, its nanopatterning being an increasingly important requirement in many applications. We report the successful nanopatterning of titanium by means of focused electron beam induced etching using XeF(2) as a precursor gas. Etch rates up to 1.25 × 10(-3) µm(3) s(-1) and minimum pattern sizes of 80 nm were obtained. Different etching parameters such as beam current, beam energy, dwell time and pixel spacing are systematically investigated, the etching process being optimized by decreasing both the beam current and the beam energy. The etching mechanism is investigated by transmission electron microscopy. Potential applications in nanotechnology are discussed.

9.
Nanotechnology ; 22(2): 025302, 2011 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-21135470

RESUMEN

We systematically study the effect of oxygen content on the magneto-transport and microstructure of Fe:O:C nanowires deposited by focused-electron-beam-induced (FEBID) deposition. The Fe/O ratio can be varied with an Fe content varying between ∼ 50 and 80 at.% with overall low C content (≈16 ± 3 at.%) by adding H(2)O during the deposition while keeping the beam parameters constant as measured by energy dispersive x-ray (EDX) spectroscopy. The room-temperature magnetic properties for deposits with an Fe content of 66-71 at.% are investigated using the magneto-optical Kerr effect (MOKE) and electric magneto-transport measurements. The nanostructure of the deposits is investigated through cross-sectional high-resolution transmission electron microscopy (HRTEM) imaging, allowing us to link the observed magneto-resistance and resistivity to the transport mechanism in the deposits. These results demonstrate that functional magnetic nanostructures can be created, paving the way for new magnetic or even spintronics devices.

10.
Behav Processes ; 173: 104064, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32006621

RESUMEN

The study of traits that enable species to thrive in urban habitats is critical to a better understanding the evolution of urban ecosystems. Here, we examined variation in boldness, neophobia, and exploratory behavior in a generalist raptor, the Chimango Caracara, Milvago chimango, occurring in areas with different urbanization level. We also focused on the relationship between object exploration and neophobia in rural and urban population of this species. The results showed that birds from more urbanized habitats showed more tolerance to humans than rural raptors, without any effect of age and sex in this trait. Rural birds were also more neophobic and were slower to explore than urban raptors, though they dedicated a similar amount of time to exploring novel objects, indicating a non-correspondence between the speed to approach and contact these objects and the amount of exploration performed. Finally, we found a correlation between exploration speed and neophobia in rural birds, whereas for urban raptors this correlation was not observed. Our results show that urbanization not only influences the expression of risk-taking behaviors and novelty responses in the chimango, but can also modify the relationship between exploration and neophobia.


Asunto(s)
Conducta Exploratoria/fisiología , Falconiformes/fisiología , Asunción de Riesgos , Animales , Ecosistema , Femenino , Masculino , Fenotipo , Urbanización
11.
Nanotechnology ; 20(47): 475704, 2009 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-19858555

RESUMEN

We systematically study individual micro- and nanometric polycrystalline cobalt wires grown by focused-electron-beam-induced-deposition. The deposits were grown in a range of aspect ratios varying from 1 up to 26. The minimum lateral dimension of the nanowires was 150 nm, for a thickness of 40 nm. Atomic force microscopy images show beam-current-dependent profiles, associated with different regimes of deposition. The magnetization reversal of individual nanowires is studied by means of the spatially resolved magneto-optical Kerr effect. Abrupt switching is observed, with a systematic dependence on the wire's dimensions. This dependence of the coercive field is understood in magnetostatic terms, and agrees well with previous results on cobalt wires grown with different techniques. The influence of compositional gradients along the structural profile on the magnetic reversal is studied by using micromagnetic simulations. This work demonstrates the feasibility of using this technique to fabricate highly pure magnetic nanostructures, and highlights the advantages and disadvantages of the technique with respect to more conventional ones.

12.
Transplant Proc ; 50(2): 428-432, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29579820

RESUMEN

INTRODUCTION: As a pretransplantation evaluation, renal function is determined by the glomerular filtration rate (GFR) with the use of renal scintigraphy (RS) and the estimated glomerular filtration rate (eGFR). To date, there are few studies that correlate renal cortex volume with eGFR determined with renal gammagram (GR) and eGFR by equations (Cockroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equation) in Latin American living donors. AIM: This study sought to determine whether there is correlation of the volume of the renal cortex by Herts equation with the GFR determined with renal gammagram (GFR-GR). PATIENTS AND METHODS: This was an analytical, observational, and cross-sectional study. A review of the donor charts from January 1, 2014, to December 1, 2014, with a complete clinical file, kidney measurements, predonation tomography volume, and eGFR by different formulas and by renal scintigraphy. RESULTS: Thirty-three donors were included, 51.5% male and 48.5% female. The mean age was 38.58 ± 10 years, with an average volume of 127.83 ± 28.30 mL, with diethylenetriamine-pentaacetate (DTPA) of 54.80 ± 7.13 mL/min/1.73 m2 in the donated kidney. Spearman correlation showed the best association with the Herts equation (r = 0.346) reaching significance (P = .049) when comparing the different equations against the GFR with DTPA. Using the Bland-Altman method, the lowest variability and best significance was verified with the same equation compared to the other formulas (P = .0002). CONCLUSIONS: There is no consensus regarding which is the best formula for calculating the GFR of both kidneys. Of the different formulas, the one that best correlated with the GFR was the Herts method, which uses the volume of the kidney.


Asunto(s)
Tasa de Filtración Glomerular , Pruebas de Función Renal/métodos , Riñón/anatomía & histología , Nefrectomía , Periodo Preoperatorio , Recolección de Tejidos y Órganos/métodos , Adulto , Estudios Transversales , Femenino , Humanos , Riñón/diagnóstico por imagen , Riñón/fisiología , Trasplante de Riñón , Donadores Vivos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada por Rayos X/estadística & datos numéricos
13.
Clin Transl Oncol ; 20(9): 1117-1126, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29435944

RESUMEN

Population aging represents a worldwide challenge. In Ibero-America (Spain, Portugal, and the American countries in which the Spanish or Portuguese language are spoken), the number of older adults is growing, leading to an increase in aging-related diseases such as cancer. Older adults already account for half of all cancer cases in Ibero-America, and this proportion will continue to increase. Furthermore, Ibero-American healthcare systems are not adequately prepared to provide care for older adults with cancer, mainly due to a lack of resources and generalized paucity of geriatric training for healthcare providers. Across the region, several clinical initiatives, educational activities and research collaborations have been established to set the foundations of Ibero-American geriatric oncology and to increase the geriatric knowledge among healthcare providers. This article provides an overview of the current landscape of geriatric oncology in Ibero-America, highlighting its critical challenges, opportunities for improvement and collaboration, and future directions.


Asunto(s)
Envejecimiento , Geriatría , Neoplasias/terapia , Atención a la Salud , Humanos , Neoplasias/epidemiología , Portugal/epidemiología , España/epidemiología
14.
Bone Marrow Transplant ; 40(11): 1063-7, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17906706

RESUMEN

Toxicity related to autologous PBSC infusion is well known and traditionally attributed to the presence of DMSO as cryoprotectant. But despite DMSO depletion, adverse events continue appearing. We have conducted a retrospective study to determine the incidence of adverse events related to the PBSC infusion in a large series of 144 patients. Adverse effects were observed in 67.36% of patients, although most of them were of grade 1 or 2. The adverse events most frequently reported were allergic reactions, followed by general, gastrointestinal and respiratory symptoms. In the univariate analysis, age (P=0.01), the volume infused (P=0.005), the amount of DMSO (P=0.008), the total nucleated cells (P=0.002), the total number of granulocytes (P=0.000001) and clumping (P=0.000001) were associated with the occurrence of adverse events. In the multivariate analysis, two protective factors, age (P=0.05) and sex (P=0.004), and two risk factors, the number of granulocytes, with a relative risk of 1.18 (95% confidence interval, 1.06-1.31) (P=0.002), and clumping, with an relative risk of 1.94 (95% confidence interval, 1.15-3.29) (P=0.013), were identified. The best cutoff point for the prediction of the occurrence of adverse events, with a sensitivity of 47% and specificity of 89%, was 6.065 x 10(9) granulocytes.


Asunto(s)
Recuento de Leucocitos , Trasplante de Células Madre de Sangre Periférica/efectos adversos , Trasplante Autólogo/efectos adversos , Adulto , Factores de Edad , Agregación Celular , Femenino , Granulocitos , Humanos , Leucaféresis , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales
16.
J Psychiatr Ment Health Nurs ; 24(8): 563-569, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28544130

RESUMEN

WHAT IS KNOWN ON THE SUBJECT?: Informal caregivers of psychiatric patients are vulnerable to many disturbances associated with the stress related to their activity. Caregivers who show a coping style focused on problem-solving report less psychological distress, and this approach positively influences the recovery process of the psychiatric patient. There are some questionnaires to measure coping styles in caregivers of psychiatric patients, but most of them do not have the minimum psychometric properties that a scale must fulfil. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: The authors present an adapted and validated scale for measuring both active and passive coping strategies used by informal caregivers to face daily stressful situations with psychiatric patients. The study is an example of how scales can be adapted to small samples (n < 200). WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The scale could be helpful for generating strategies to support the family caregiver, as well as for measuring the results of interventions. The scale could also be used to identify how coping styles of informal caregivers are related to recovery process of psychiatric patients. ABSTRACT: Background The recovery process of a psychiatric patient is related to his primary informal caregiver's style of coping with stress. There is insufficient literature on validations of instruments that measure coping styles in this population. Objective To adapt and validate a scale to measure coping strategies in primary informal caregivers. Method The adapted scale was based on the Extreme Coping Scale of López-Vázquez and Marván. Items from that scale were adapted for application to informal caregivers. The scale was administered to 122 primary informal caregivers of patients from two psychiatric institutions in Mexico. Psychometric analyses were performed to determine the scale's properties. Results The scale was composed of 20 items (six less than in the original scale) and two factors: (i) active coping (Cronbach's alpha = .837) and (ii) passive coping (Cronbach's alpha = .718). Discussion The findings are discussed in the light of the importance of studying the relationship between coping styles and the well-being of both informal caregivers and psychiatric patients. Implications for practice The scale could be used by health practitioners and researchers to generate strategies to support the family caregiver, as well as to measure the results of interventions.


Asunto(s)
Adaptación Psicológica/fisiología , Cuidadores/psicología , Familia/psicología , Trastornos Mentales/enfermería , Psicometría/instrumentación , Encuestas y Cuestionarios/normas , Adolescente , Adulto , Anciano , Humanos , Persona de Mediana Edad , Adulto Joven
17.
Sci Rep ; 7(1): 5663, 2017 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-28720833

RESUMEN

Superconductivity and ferromagnetism are two antagonistic phenomena that combined can lead to a rich phenomenology of interactions, resulting in novel physical properties and unique functionalities. Here we propose an original hybrid system formed by a high-temperature superconducting film, patterned with antidots, and with ferromagnetic nano-rods grown inside them. This particular structure exhibits the synergic influence of superconductor (SC) - ferromagnetic (FM) stray fields, in both the superconducting behaviour of the film and the three-dimensional (3D) magnetic structure of nano-rods. We show that FM stray fields directly influence the critical current density of the superconducting film. Additional functionalities appear due to the interaction of SC stray fields, associated to supercurrent loops, with the non-trivial 3D remanent magnetic structure of FM nano-rods. This work unravels the importance of addressing quantitatively the effect of stray magnetic fields from both, the superconductor and the ferromagnet in hybrid magnetic nano-devices based on high temperature superconductors.

18.
Obstet Gynecol ; 61(3): 383-8, 1983 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6823381

RESUMEN

Fifty-six fine needle aspirations of lymphangiographically abnormal pelvic and para-aortic lymph nodes were performed in 50 patients at The University of Michigan between January 1, 1977, and May 31, 1980. Fine needle aspiration was used both in the initial evaluation of patients with gynecologic malignancies and in the investigation of persistent and recurrent malignant disease. The overall diagnostic accuracy of fine needle aspiration was 74.0%. Fine needle aspiration yielded diagnostic cytologic specimens; it was safe and well tolerated, and in some instances it permitted the diagnosis of lymph node metastasis without laparotomy.


Asunto(s)
Biopsia con Aguja/métodos , Ganglios Linfáticos/patología , Metástasis Linfática/diagnóstico , Linfografía , Pelvis , Femenino , Neoplasias de los Genitales Femeninos/diagnóstico por imagen , Neoplasias de los Genitales Femeninos/patología , Humanos
19.
Int J Gynaecol Obstet ; 63 Suppl 1: S19-24, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10075208

RESUMEN

The objectives were to investigate the death of women by violent injuries, including induced abortion, in the Province of Córdoba, Argentina, 1992-1996 and to perform a bibliographic review on maternal death due to violence. Reports of autopsies of all violent deaths in women aged 12-44 years were reviewed to determine the cause of death for cases of suicide, homicide, accident or induced abortion and a bibliographic review was performed through MEDLINE. Two hundred and seventy two women died due to violence, including 22 which were due to complications of induced abortion. The remaining 250 deaths were: 44 (17.6%) by suicide, 51 (20.4%) by homicide and 155 (62%) by traffic accidents, including 6 pregnant women (2 died by suicide, 1 by homicide and 3 by accidents). Violence against women and pregnant women is a growing problem in developing countries. The implication of a simplified screening has been proposed to identify abuses against women, searching for frequency of abuse, its severity and to determine who provokes it.


Asunto(s)
Mortalidad Materna , Maltrato Conyugal/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Argentina/epidemiología , Niño , Recolección de Datos , Femenino , Humanos , Incidencia , Embarazo , Factores de Riesgo
20.
Med Clin (Barc) ; 109(4): 121-4, 1997 Jun 21.
Artículo en Español | MEDLINE | ID: mdl-9289524

RESUMEN

BACKGROUND: The aim of this study was to analyse and to verify the efficacy of systematic advice for alcoholism prevention, assessing the reduction of the number in risk drinkers. PATIENTS AND METHODS: A multicenter randomized controlled clinical trial was designed, to perform in general practitioner setting, on a sample of risk drinkers (alcohol intake > 280 g weekly, without dependence) sent by random in intervention group (systematic brief advice with support material and a five visit program during a year) and control group (once brief advice and a control in 1 year). The procedure to incorporate in both groups included physical exam, a blood test and the MALT questionnaire. A descriptive and analytic study on included variables was realised, assessing the percentage of drinkers who reduced alcohol intake below risk limit at the end of a year follow up, as well as the reduction intake in each group. RESULTS: Of the 139 included males, 75 were in the intervention group and 64 in the control group. The percentage of patients not excluded by MALT > 10, and/or liver disease, that finished the 1 year follow up, was 46%, being the sample average age of 43 +/- 11.8. Patients included in both groups were initially comparable. At the end of a year follow up there were statistically significant differences in: percentage of risk drinkers who decreased alcohol intake below 280 g weekly (82% intervention group; 47% control group); percentage of reduction in GPT, GGT, triglycerides, systolic blood pressure and the MALT questionnaire. CONCLUSIONS: The efficacy of isolated advice of general practitioner was proved to achieve the alcohol intake reduction below the risk limit accepted in male risk drinkers without alcohol dependence. The systematic follow up during a year significantly improves the results achieved with the isolated advice.


Asunto(s)
Alcoholismo/prevención & control , Educación del Paciente como Asunto , Adulto , Medicina Familiar y Comunitaria , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
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