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1.
J Chem Phys ; 157(24): 244504, 2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36586975

RESUMEN

We investigate the structural relaxation of a soft-sphere liquid quenched isochorically (ϕ = 0.7) and instantaneously to different temperatures Tf above and below the glass transition. For this, we combine extensive Brownian dynamics simulations and theoretical calculations based on the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory. The response of the liquid to a quench generally consists of a sub-linear increase of the α-relaxation time with system's age. Approaching the ideal glass-transition temperature from above (Tf > Ta), sub-aging appears as a transient process describing a broad equilibration crossover for quenches to nearly arrested states. This allows us to empirically determine an equilibration timescale teq(Tf) that becomes increasingly longer as Tf approaches Ta. For quenches inside the glass (Tf ≤ Ta), the growth rate of the structural relaxation time becomes progressively larger as Tf decreases and, unlike the equilibration scenario, τα remains evolving within the whole observation time-window. These features are consistently found in theory and simulations with remarkable semi-quantitative agreement and coincide with those revealed in a previous and complementary study [P. Mendoza-Méndez et al., Phys. Rev. 96, 022608 (2017)] that considered a sequence of quenches with fixed final temperature Tf = 0 but increasing ϕ toward the hard-sphere dynamical arrest volume fraction ϕHS a=0.582. The NE-SCGLE analysis, however, unveils various fundamental aspects of the glass transition, involving the abrupt passage from the ordinary equilibration scenario to the persistent aging effects that are characteristic of glass-forming liquids. The theory also explains that, within the time window of any experimental observation, this can only be observed as a continuous crossover.


Asunto(s)
Vidrio , Simulación de Dinámica Molecular , Temperatura , Temperatura de Transición , Vidrio/química
2.
Neurologia (Engl Ed) ; 36(5): 353-360, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34714233

RESUMEN

INTRODUCTION: The Free and Cued Selective Reminding Test (FCSRT) is widely used for the assessment of verbal episodic memory, mainly in patients with Alzheimer disease. A Spanish-language version of the FCSRT and normative data were developed within the NEURONORMA project. Availability of alternative, equivalent versions is useful for following patients up in clinical settings. This study aimed to develop an alternative version of the original FCSRT (version B) and to study its equivalence to the original Spanish-language test (version A), and its performance in a sample of healthy individuals, in order to develop reference data. METHODS: We evaluated 232 healthy participants of the NEURONORMA-Plus project, aged between 18 and 90. Thirty-three participants were assessed with both test versions using a counterbalanced design. RESULTS: High intra-class correlation coefficients (between 0.8 and 0.9) were observed in the equivalence study. While no significant differences in performance were observed in total recall scores, free recall scores were significantly lower for version B. CONCLUSIONS: These preliminary results suggest that the newly developed FCSRT version B is equivalent to version A in the main variables tested. Further studies are necessary to ensure interchangeability between versions. We provide normative data for the new version.


Asunto(s)
Lenguaje , Memoria Episódica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Señales (Psicología) , Humanos , Recuerdo Mental , Persona de Mediana Edad , Pruebas Neuropsicológicas , Adulto Joven
3.
Eur J Clin Microbiol Infect Dis ; 39(6): 1089-1094, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31980987

RESUMEN

The epidemiology of non-tuberculous mycobacteria (NTM) in Spain is largely unknown because systematic reporting is not compulsory. The aim of our study was to describe the frequency and diversity of NTM species in our region and their distribution according to the source sample, gender, and age of the patients. We performed a multicenter study of all NTM isolated in 24 public hospitals in Madrid from 2013 to 2017. A total of 6.923 mycobacteria were isolated: 4535 (65.5%) NTM, and 2.388 (34.5%) Mycobacterium tuberculosis complex (MTB). Overall, 61 different NTM species were identified. The most frequently isolated species were Mycobacterium avium complex (47.7%), M. lentiflavum (12.2%), M. gordonae (9.2%), M. fortuitum (8.9%), and M. abscessus (3.9%). Whereas MTB cases were stable during the study period, the number of NTM isolates increased considerably from 930 isolates in 2013 to 1012 in 2017; a sharp increase occurred in the last year. The rise in NTM isolates was mostly due to M. lentiflavum, M. kansasii, and M. abscessus mainly isolated from respiratory specimens in patients older than 60. The increase in isolation rate of NTM in our region is consistent with the increasing rates reported worldwide in the last decades. The rise in NTM isolates was mainly attributed to M. lentiflavum but it also should be noted the increasing of species with high pathogenic potential such as M. kansasii and M. abscessus.


Asunto(s)
Infecciones por Mycobacterium no Tuberculosas/epidemiología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Micobacterias no Tuberculosas/aislamiento & purificación , Femenino , Humanos , Laboratorios de Hospital , Masculino , Persona de Mediana Edad , Micobacterias no Tuberculosas/clasificación , Estudios Retrospectivos , España/epidemiología , Tuberculosis/epidemiología , Tuberculosis/microbiología
4.
J Healthc Qual Res ; 34(4): 209-216, 2019.
Artículo en Español | MEDLINE | ID: mdl-31713532

RESUMEN

INTRODUCTION: the main aim of this study was to develop and implement a risk map in the Oral and Maxillofacial Surgery Service of the University Hospital «Virgen de las Nieves¼ of Granada to minimize the incidence of adverse effects (AE). MATERIALS AND METHODS: Longitudinal, prospective study carried out in the Oral and Maxillofacial Surgery Service of the Hospital Universitario Virgen de las Nieves of Granada, from June 2017 to May 2018, through the methodology of «Analysis and Failure Mode Effect¼. Management of the different AE was addressed. The following phases were considered as it follows: identification of the problem, identification of AE for within the practice of the oral and maxillofacial surgery that represents a problem in the assistive safety, creation of an interdisciplinary working group, analysis of the current situation in patient safety and risk management using 2analysis tools, SWOT and PITELO, preparation of the patient care process, development of a catalog of AE and preparation of a risk map. RESULTS: A total of 33 AE were identified. The risk map showed a higher incidence of AE in the Surgical Area (22) compared to the areas of Outpatient Clinic and Hospital Discharge (6). A total of 10 critical AE were identified. CONCLUSIONS: The elaboration of a risk map allowed to determine the process of the oral and maxillofacial surgical patient, and to elaborate a catalog of AE.


Asunto(s)
Procedimientos Quirúrgicos Orales/efectos adversos , Seguridad del Paciente , Gestión de Riesgos/organización & administración , Cirugía Bucal , Unidades Hospitalarias , Humanos , Complicaciones Posoperatorias/prevención & control , Estudios Prospectivos , Medición de Riesgo/métodos , Gestión de Riesgos/métodos
6.
J Healthc Qual Res ; 33(5): 256-263, 2018.
Artículo en Español | MEDLINE | ID: mdl-30361103

RESUMEN

INTRODUCTION: Patient safety in oral and maxillofacial surgery is oriented towards providing patient care by means of adequate risk management that minimises adverse events and fosters a culture of safe clinical practices as the fundamental basis of quality health care. To implement preventive actions are implemented in order to improve patient safety and to reduce the incidence of adverse events, as well as to improve the quality of care. The aim of this report is to implement preventive measures in order to improve the health care of the patient in an Oral and Maxillofacial Surgery Unit by reducing the Adverse Events and proving good quality healthcare. MATERIALS AND METHODS: A longitudinal, prospective, single centre study was conducted using a methodology of analysis of modes of failure and effects of the management of potentially serious adverse events in the Oral and Maxillofacial surgical unit of the University Hospital of Granada (June-November 2017), as well as the preparation and implementation of a series of corrective measures. RESULTS: A total of 33 adverse events were recorded, with 10 of them considered as critical, distributed in different areas of care, and referred from Primary Health Care and from other hospitals. Seven preventive actions were implemented: information to the patient, training actions, improvements in the protocols and procedures, in the care process and clinical practice, as well as the need to set up an adequate checklist, and other miscellaneous. DISCUSSION: The implementation of preventive measures represent a notable advance in the prevention of harm to the patient and the organisation, involving healthcare staff in a safety culture oriented towards quality care.


Asunto(s)
Errores Médicos/prevención & control , Procedimientos Quirúrgicos Orales/efectos adversos , Seguridad del Paciente , Complicaciones Posoperatorias/prevención & control , Calidad de la Atención de Salud , Lista de Verificación , Humanos , Procedimientos Quirúrgicos Orales/normas , Sistemas de Identificación de Pacientes , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Gestión de Riesgos/organización & administración
8.
ACS Appl Mater Interfaces ; 10(16): 13361-13372, 2018 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-29627980

RESUMEN

The use of implants carries on a series of problems, among them infections, poor biocompatibility, high levels of cytotoxicity, and significant mechanical differences between implants and host organs that promote stress shielding effects. These problems indicate that the materials used to make implants must meet essential requirements and high standards for implantations to be successful. In this work, we present the synthesis, characterization and evaluation of the antibiofilm, mechanical, and thermal properties, and cytotoxic effect of a nanocomposite-based scaffold on polyurethane (PU) and gold nanoparticles (AuNPs) for soft tissue applications. The effect of the quantity of AuNPs on the antibacterial activity of nanocomposite scaffolds was evaluated against Staphylococcus epidermidis and Klebsiella spp., with a resulting 99.99% inhibition of both bacteria using a small quantity of nanoparticles. Cytotoxicity was evaluated with the T10 1/2 test against fibroblast cells. The results demonstrated that porous nanogold/PU scaffolds have no toxic effects on fibroblast cells to the 5 day exposition. With respect to mechanical properties, stress-strain curves showed that the compressive modulus and yield strength of PU scaffolds were significantly enhanced by AuNPs (by at least 10 times). This is due to changes in the arrangement of hard segments of PU, which increase the stiffness of the polymer. Thermogravimetric analysis showed that the degradation onset temperature rises with an increase in the quantity of AuNPs. These properties and characteristics demonstrate that porous nanogold/PU scaffolds are suitable material for use in soft tissue implants.


Asunto(s)
Poliuretanos/química , Materiales Biocompatibles , Supervivencia Celular , Oro , Nanopartículas del Metal , Porosidad , Ingeniería de Tejidos , Andamios del Tejido
9.
Ecotoxicol Environ Saf ; 147: 275-282, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28850810

RESUMEN

Triclosan is a personal care product widely used in North America, Europe and Asia as antimicrobial ingredient in many consumer chemical products. In Mexico concentrations of triclosan have been reported in aquatic systems. However, there is no law regulating the presence of chemicals such as triclosan, in aquatic systems. The scarce data about this chemical has increased concern among ecotoxicologists regarding possible effects on aquatic organisms. Moreover, multigenerational studies are rarely studied and the results vary depending on the contaminant. Rotifers, are a dominant group of zooplankton, and have been used in aquatic risk assessments of personal care products due to their sensitivity and high reproductive rates. Plationus patulus and Brachionus havanaensis are common rotifers distributed in aquatic ecosystems of Mexico and have been used in ecotoxicological bioassays. In this study, the median lethal concentration (LC50, 24h) of P. patulus and B. havanaensis exposed to triclosan was determined. Based on the LC50, we tested three sublethal concentrations of triclosan to quantify the demographic responses of both rotifers for two successive generations (F0, and F1). The 24h LC50 of triclosan for P. patulus and B. havanaensis were 300 and 500µgL-1 respectively. Despite the concentration, triclosan had an adverse effect on both Plationus patulus and Brachionus havanaensis in both generations exposed. Experiments show that P. patulus was more sensitive than B. havanaensis when exposed to triclosan. When exposed to triclosan the parental generation (F0) of P. patulus was far more affected than F1.


Asunto(s)
Rotíferos/efectos de los fármacos , Triclosán/toxicidad , Contaminantes Químicos del Agua/toxicidad , Zooplancton/efectos de los fármacos , Animales , Dosificación Letal Mediana , México , Dinámica Poblacional/tendencias , Reproducción/efectos de los fármacos , Rotíferos/crecimiento & desarrollo , Especificidad de la Especie , Pruebas de Toxicidad Aguda , Pruebas de Toxicidad Crónica
10.
Acta Neurochir Suppl ; 124: 221-229, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28120078

RESUMEN

Central autonomic control nuclei and pathways are mainly integrated within the brainstem, especially in the medulla oblongata. Lesions within these structures can lead to central dysautonomia.Central autonomic control structures can be damaged by tumors, during surgery, or by other neurosurgical pathologies. These may elicit clinical or subclinical autonomic complications that can constitute a serious clinical problem.The authors present a broad review of the central autonomic nervous system, its possible dysfunctions, and the relation between neurosurgery and this "not-well-known system". Preliminary results of an autonomic study of brainstem lesions that is currently being carried out by the authors are also shown.


Asunto(s)
Neoplasias del Tronco Encefálico/cirugía , Tronco Encefálico/cirugía , Complicaciones Posoperatorias/fisiopatología , Disautonomías Primarias/fisiopatología , Tronco Encefálico/fisiopatología , Neoplasias del Tronco Encefálico/complicaciones , Humanos , Disautonomías Primarias/etiología
11.
Bull Entomol Res ; 107(2): 225-233, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27876100

RESUMEN

Buenos Aires city is located near the southern limit of the distribution of Aedes aegypti (Diptera: Culicidae). This study aimed to assess long-term variations in the abundance of Ae. aegypti in Buenos Aires in relation to changes in climatic conditions. Ae. aegypti weekly oviposition activity was analyzed and compared through nine warm seasons from 1998 to 2014, with 200 ovitraps placed across the whole extension of the city. The temporal and spatial dynamics of abundances were compared among seasons, and their relation with climatic variables were analyzed. Results showed a trend to higher peak abundances, a higher number of infested sites, and longer duration of the oviposition season through subsequent years, consistent with a long-term colonization process. In contrast, thermal favorability and rainfall pattern did not show a consistent trend of changes. The long-term increase in abundance, and the recently documented expansion of Ae. aegypti to colder areas of Buenos Aires province suggest that local populations might be adapting to lower temperature conditions. The steadily increasing abundances may have implications on the risk of dengue transmission.


Asunto(s)
Aedes/fisiología , Insectos Vectores , Adaptación Fisiológica , Animales , Argentina , Clima , Frío , Dengue/transmisión , Insectos Vectores/fisiología , Oviposición , Dinámica Poblacional , Estaciones del Año
12.
Rev. otorrinolaringol. cir. cabeza cuello ; 76(3): 295-300, dic. 2016. ilus, tab
Artículo en Español | LILACS | ID: biblio-845629

RESUMEN

Los tumores neuroectodérmicos primitivos son tumores muy infrecuentes. Derivan de células embrionarias de la cresta neural, y comparten características con los sarcoma de Ewing extraóseos. Se presentan habitualmente en niños y adultos jóvenes, su ubicación más frecuente es en la región toracopulmonar, abdomen y extremidades. Son tumores que presentan una agresividad importante, lo que condiciona un pronóstico sombrío. La ubicación en fosas nasales-cavidades perinasales es anecdótica, existiendo el reporte de tan sólo un caso en la literatura mundial de ubicación en cavidad nasal.


Primitive neuroectodermal tumors are rare malignancies arising from embryonic neural crest cells. They share characteristics with extraosseous Ewing sarcoma. They usually occur in children and young adults and the most common location is the thoracopulmonary region, abdomen and extremities. These tumors have significant aggressiveness, which determines their poor prognosis. The location in nasal fossa-paranasal cavities is anecdotal. Until now only one previous case has been reported in the located in the nasal fossa.


Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Tumores Neuroectodérmicos Primitivos/diagnóstico , Tumores Neuroectodérmicos Primitivos/cirugía , Neoplasias Nasales/diagnóstico , Neoplasias Nasales/cirugía
13.
Transplant Proc ; 48(2): 457-62, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27109978

RESUMEN

BACKGROUND: Intestinal failure (IF) patients received parenteral nutrition (PN) as the only available therapy until intestinal transplantation (ITx) evolved as an accepted treatment. The aim of this article is to report the long-term outcomes of a series of ITx performed in pediatric and adult patients at a single center 9 years after its creation. PATIENTS AND METHODS: This is a retrospective analysis of the ITx performed between May 2006 and January 2015. Diagnoses, pre-ITx mean time on PN, indications for ITx, time on the waiting list for types of ITx, mean total ischemia time, and warm ischemia time, time until PN discontinuation, incidence of acute and chronic rejection, and 5-year actuarial patient survival are reported. RESULTS: A total of 42 patients received ITx; 80% had short gut syndrome (SG); the mean time on PN was 1620 days. The main indication for ITx was lack of central venous access followed by intestinal failure-associated liver disease (IFALD) and catheter-related infectious complications. The mean time on the waiting list was 188 days (standard deviation, ±183 days). ITx were performed in 26 children and 14 adults. In all, 32 procedures were isolated ITx (IITX); 10 were multiorgan Tx (MOT; 3 combined, 7 multivisceral Tx (MVTx), 1 modified MVTx and 2 with kidney); 2 (4.7 %) were retransplantations: 1 IITx, 1 MVTx, and 5 including the right colon. Thirteen patients (31%) received abdominal rectus fascia. All procedures were performed by the same surgical team. Total ischemia time was 7:53 ± 2:04 hours, and warm ischemia time was 40.2 ± 10.5 minutes. The mean length of implanted intestine was 325 ± 63 cm. Bishop-Koop ileostomy was performed in 67% of cases. In all, 16 of 42 Tx required early reoperations. The overall mean follow-up time was 41 ± 35.6 months. The mean time to PN discontinuation after Tx was 68 days (P = .001). The total number of acute cellular rejection (ACR) episodes until the last follow-up was 83; the total number of grafts lost due to ACR was 4; and the total graft lost due to chronic rejection was 3. At the time of writing, the overall 5-year patient survival is 55% (65% for IITx vs 22% for MOT; P = .0001); 60% for pediatric recipients vs 47% for adults (P = NS); 64% when the indication for ITx was SG vs 25% for non-SG (P = .002). CONCLUSIONS: At this center, candidates with SG, in the absence of IFALD requiring IITx, showed the best long-term outcomes, independent of recipient age. A multidisciplinary approach is mandatory for the care of intestinal failure patients, to sustain a rehabilitation and transplantation program over time.


Asunto(s)
Rechazo de Injerto/epidemiología , Intestinos/trasplante , Fallo Renal Crónico/cirugía , Fallo Hepático/cirugía , Trasplante de Hígado , Nutrición Parenteral Total/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Síndrome del Intestino Corto/cirugía , Adulto , Argentina , Niño , Femenino , Humanos , Enfermedades Intestinales/complicaciones , Enfermedades Intestinales/cirugía , Fallo Renal Crónico/complicaciones , Fallo Hepático/etiología , Masculino , Nutrición Parenteral Total/efectos adversos , Reoperación , Estudios Retrospectivos , Síndrome del Intestino Corto/complicaciones , Listas de Espera , Isquemia Tibia
14.
Auton Neurosci ; 194: 52-7, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26681574

RESUMEN

We report the case of a 9-year-old male patient with a recurrent fourth ventricle anaplastic ependymoma who developed severe arterial hypertension and blood pressure lability during and after surgery. A punctual bilateral lesion located within mid dorsal medulla oblongata caused by both infiltration and surgical resection was observed in postoperative MRI. Three years later, the patient remained neurologically stable but the family referred the presence of a chronic tachycardia as well as palpitations and sweating with flushing episodes related to environmental stress. On autonomic evaluation, an increase in sympathetic outflow with tachycardia together with orthostatic hypotension caused by baroreceptor reflex dysfunction was observed. We postulate that a bilateral injury to both nuclei of the solitary tract may have caused central dysautonomia.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo/etiología , Lesiones Encefálicas/etiología , Bulbo Raquídeo/patología , Complicaciones Posoperatorias/fisiopatología , Presión Sanguínea/fisiología , Neoplasias del Ventrículo Cerebral/cirugía , Niño , Ependimoma/cirugía , Frecuencia Cardíaca/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino
15.
J Mater Sci Mater Med ; 26(3): 129, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25693677

RESUMEN

In this study, an antibacterial, but not cytotoxic nanomaterial based on polyethylene and copper nanoparticles was prepared by in situ polymerization. PE-CuNps nanocomposites against Escherichia coli, completely suppressed the number of live bacteria after 12 h incubation compared to neat PE. TEM images showed that nanocomposites damage the plasma membrane of the bacteria, revealing a bacteriolytic effect. Toxic effects of copper nanoparticles on viability of neuroblastoma line cell also was evaluated, revealing a non cytotoxic effect for the doses used, showing that this nanocomposite is a ideal material for medical devices.


Asunto(s)
Antibacterianos/farmacología , Cobre/química , Nanopartículas del Metal/química , Nanocompuestos , Polietileno/química , Antibacterianos/química , Línea Celular Tumoral , Escherichia coli/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Polimerizacion
16.
Rheumatol Int ; 35(1): 107-14, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24948375

RESUMEN

To determine the prevalence of and associated factors to work instability (WI) in rheumatoid arthritis (RA) Argentinean patients. Observational cross-sectional study that assessing employment status in currently working RA patients. They answered the validated version of RA work instability scale (RA-WIS). High-risk WI was considered when RA-WIS was ≥17. Factors associated with high-risk WI were examined by univariable and multivariable analysis. Four-hundred and fifty RA patients were enrolled; of these, 205 patients were currently employed, but only 172 have completed questionnaires required [RA-WIS and health assessment questionnaire (HAQ-A)]. Their mean age was 49.3 ± 10.8 years; 81.3 % were female; and their mean disease duration was 8.1 ± 7.2 years. Fifty-two percent of patients were doing manual work. The mean RA-WIS score was 11.4 ± 6.8, and 41 % of patients had a high-risk WI. High-risk WI was associated with radiographic erosions (p < 0.001) and HAQ-A >0.87 (p < 0.001) in the univariable analysis, whereas in the multivariable logistic regression analysis the variables associated with a high-risk WI were as follows: HAQ-A >0.87 [odds ratio (OR) 12.31; 95 % CI 5.38-28.18] and the presence of radiographic erosions (OR 4.848; 95 % CI 2.22-10.5). In this model, having a higher monthly income (OR 0.301; 95 % CI 0.096-0.943) and a better functional class (OR 0.151; 95 % CI 0.036-0.632) were protective. Forty-one percent of RA working patients had high-risk WI. The predictors of high RA-WIS were HAQ-A ≥0.87 and radiographic erosions, whereas having a better functional class and have higher incomes were protective.


Asunto(s)
Artritis Reumatoide , Evaluación de la Discapacidad , Empleo , Adulto , Argentina , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios
17.
Mater Sci Eng C Mater Biol Appl ; 40: 24-31, 2014 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-24857461

RESUMEN

Since infection is a major cause of death in a patient whose immune responses have been compromised (immunocompromised patient), considerable attention has been focused on developing materials for the prevention of infections. This has been directed primarily at suppressing or eliminating the host's endogenous microbial burden and decreasing the acquisition of new organisms. In this study, the antibacterial properties of two nanocomposites, polyethylene modified with silver nanoparticles (PE-AgNps) or copper nanoparticles (PE-CuNps), against Listeria monocytogenes have been investigated. In order to elucidate the antibacterial mechanism, specifically whether this mechanism corresponds to bactericidal or bacteriolytic activities, we have determined the extent of release of metal ions (Ag(+) and Cu(2+)) and, also, the morphology of the bacteria. The metal ion release from nanocomposites was followed by inductively coupled plasma spectrometry and the morphology of the bacteria was revealed through examination of ultramicrotomed sections of bacteria in a transmission electron microscope. The study of metal ion release from the nanocomposites shows that for both nanocomposites the amount of ions released varies with time, which initially displays a linear behavior until an asymptotic behavior is reached. Further, TEM images show that silver nanoparticles (AgNps) and copper nanoparticles (CuNps), which are released from the nanocomposites, can penetrate to the cell wall and the plasma membrane of bacteria. Resulting morphological changes involve separation of the cytoplasmic membrane from the cell wall, which is known to be an effect of plasmolysis. It was revealed that the antibacterial abilities of the two nanocomposites against L. monocytogenes are associated with both bactericidal and bacteriolytic effects.


Asunto(s)
Antibacterianos/farmacología , Cobre/química , Listeria monocytogenes/efectos de los fármacos , Nanopartículas del Metal/toxicidad , Nanocompuestos/química , Polietileno/química , Plata/química , Antibacterianos/química , Iones/química , Nanopartículas del Metal/química , Microscopía Electrónica de Transmisión , Tamaño de la Partícula
18.
Environ Pollut ; 178: 23-32, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23524177

RESUMEN

We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers.


Asunto(s)
Monitoreo del Ambiente/métodos , Modelos Químicos , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/estadística & datos numéricos , Chile , Colombia , Ecosistema , Retardadores de Llama/análisis , Lógica Difusa , Éteres Difenilos Halogenados/análisis , Hidrocarburos Bromados/análisis , Medición de Riesgo/métodos , España
19.
Mem. Inst. Invest. Cienc. Salud (Impr.) ; 10(1): 46-55, jun. 2012. tab
Artículo en Español | LILACS | ID: lil-663634

RESUMEN

Paraguay posee una alta tasa de incidencia de cáncer de cuello uterino de 35/100.0000 mujeres en el año 2008 y el virus de papiloma humano (HPV) es su agente causal. La planificación de medidas de prevención puede ser beneficiada con conocimientos sobre los tipos virales, por ello, el objetivo de este estudio fue determinar características clínico-demográficas y los tipos de HPV presentes en mujeres con citología negativa para lesión escamosa intraepitelial. Estudio de corte transverso con componente analítico en 207 mujeres con citología negativa para lesión escamosa intraepitelial provenientes de centros de salud de Asunción. La tipificación fue realizada por reacción en cadena de la polimerasa utilizando cebadores MY09/11 y GP5/GP6, seguida de polimorfismo de longitud de fragmentos de restricción e hibridación lineal reversa, respectivamente. La asociación entre HPV y las características clínico-demográficas fue determinada por análisis de Chi cuadrado (EpiInfo versión 3,2). Se detectó alta frecuencia de HPV (21%), siendo el tipo predominante HPV 16 (4,3%) seguido de HPV 58/31 (2,4% cada uno). Se observó asociación entre la presencia de HPV y la edad (p=0,0002), detectándose mayor frecuencia de HPV en mujeres menores a 30 años, la cual, disminuyó al aumentar la edad, presentando un ligero aumento en mujeres de 60 años o más. En conclusión, los datos muestran una alta frecuencia de HPV y HPV 16 en mujeres menores a 30 años con citología negativa y sugieren la necesidad de realizar control posteriormente, a fin de identificar las infecciones persistentes que podrían causar lesión de cuello uterino


Asunto(s)
Neoplasias del Cuello Uterino , Virosis
20.
Neurocirugia (Astur) ; 22(5): 419-27; discussion 428, 2011 Oct.
Artículo en Español | MEDLINE | ID: mdl-22031160

RESUMEN

OBJECTIVE. To describe our experience with the endoscopic management of intraventricular tumors, analyzing biopsy effectiveness, and to compare our results with those obtained from an extensive literature review. MATERIALS AND METHODS. Between 2003 and 2010, 31 patients aged between 7 months and 77 years, diagnosed of solid and/or cystic intra and/or periventricular tumors, underwent neuroendoscopic biopsy. We analyze operative technique, pathological result, management of associated hydrocephalus, rate of complications and postoperative technique. RESULTS. 32 endoscopic procedures were done and biopsy was successfully performed in 28 cases, with positive histological result in 25 of them (78% success rate per procedure and 89% success rate per biopsy). Most frequent pathological diagnosis was grade II astrocytoma. 30 patients had associated hydrocephalus that required endoscopic third ventriculostomy (19 cases, with 73.7% success rate) and/or septostomy (12 patients, 3 associated with ventriculostomy and 9 with ventriculo-peritoneal shunt). Frameless neuronavigation was used in three selected cases. During the surgery and the postoperative period the following complications appeared: intraventricular hemorrhage in four cases (two of them died), seizures in two patients, new neurological findings in three cases (Parinaud's sign, transient palsy of third cranial nerve and hemiparesis associated with palsy of third cranial nerve), and cerebrospinal fluid leak and infection in one case. 19 patients received subsequent treatment (microsurgical resection in 1, radiosurgery in 2, radiotherapy in 8, chemotherapy in 5 and chemo-radiotherapy in 3). CONCLUSIONS. Endoscopic management of intraventricular and/or periventricular brain tumors is effective, and allow diagnostic biopsy and simultaneous treatment of the associated hydrocephalus in many cases. So, it could be the treatment of choice in those tumors that are not suitable for microsurgical resection. Although this technique is not exempt of serious complications, morbimortality could be lower than conventional microsurgical approach.


Asunto(s)
Biopsia/métodos , Neoplasias del Ventrículo Cerebral/diagnóstico , Neoplasias del Ventrículo Cerebral/cirugía , Neuroendoscopía/métodos , Adolescente , Adulto , Anciano , Biopsia/efectos adversos , Neoplasias del Ventrículo Cerebral/patología , Niño , Preescolar , Humanos , Hidrocefalia/etiología , Lactante , Masculino , Persona de Mediana Edad , Neuroendoscopía/efectos adversos , Complicaciones Posoperatorias , Estudios Retrospectivos , Ventriculostomía/efectos adversos , Ventriculostomía/métodos , Adulto Joven
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