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1.
Aesthetic Plast Surg ; 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38898241

RESUMEN

BACKGROUND: Body dysmorphic disorder (BDD) is a psychiatric condition characterized by persistent concern with non-existent or minor defects in one's physical appearance. BDD can be difficult to identify as patients often have limited insight into the condition. OBJECTIVE: We aimed to determine the prevalence of BDD in patients presenting to private aesthetic clinical settings in four Latin American countries. METHODS: We conducted a cross-sectional study From August to October 2022 to evaluate the prevalence of BDD among 360 patients seeking nonsurgical cosmetic procedures in Chile, Mexico, Argentina, and Colombia using the Dysmorphic Concern Questionnaire (DCQ). We reported prevalence estimates for the lowest and highest previously proposed DCQ cutoff points. RESULTS: The DCQ total scores in the study population ranged from 0 to 21, with a mean total score of 5.1 ± 3.4. The prevalence of positive screening results for BDD (total DCQ score ≥ 9) was 15.8%. The prevalence of a likely diagnosis of BDD (total DCQ score of ¥ 17) was 0.83%. LIMITATIONS: The convenience sample limited the generalizability of the findings to Latin America. CONCLUSION: We encourage colleagues to be more mindful of this diagnosis and to facilitate earlier psychological evaluation in patients who are positive for BDD. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

2.
Rev. enferm. Inst. Mex. Seguro Soc ; 32(1): e1405, dic. 26, 2023.
Artículo en Español | LILACS | ID: biblio-1531734

RESUMEN

Introducción: se estima escasez de 5.9 millones de profesionistas de la salud a nivel mundial. La Enfermería de Práctica Avanzada (EPA), cuenta con conocimientos, competencias y habilidades clínicas específicas para actuar en situaciones de déficit de personal médico, tratando desde enfermedades agudas hasta crónico degenerativas, preservando tanto la salud mental como física. Objetivo: Determinar el desempeño de la Enfermería de Práctica Avanzada en el Sector Salud. Metodología: revisión sistemática sobre la EPA, que incluyó revisiones y artículos originales del periodo 2013-2022 en español e inglés, acerca de su desempeño: evolución, aceptación y reconocimiento. Para la identificación, cribado e inclusión de los artículos se utilizó el modelo PRISMA 2020. Resultados: de un total de 838 artículos identificados, se incluyeron 20 artículos y 7 de otras fuentes como citas y otros sitios web, obteniendo un total de 27 artículos de revisión, que abordan la evolución, la aceptación y reconocimiento. Se realizó análisis cualitativo. Conclusiones: el desempeño de EPA surge por las demandas poblacionales de atención primaria a la salud, diversos países ya cuentan con EPA, asistiendo a sus habitantes desde sus especialidades. La EPA es diversa y extensa, su profesionalización debe ser continua y permanente. En México falta camino para tomar la EPA como parte del equipo multidisciplinario


Abstract Introduction: About 5.9 millions healthcare professionals lack across the world. The Advanced Practice Nursing (APN), has specific knowledge, competences, and clinical abilities to act in medical absence, taking care from acute illness until chronic diseases, preserving both mental and physical health. Objective: To determine the Advanced Practice Nursing (APN) performance in the Health Sector. Methods: A systematic review about APN, including reviews and original articles from the period 2013-2022 in Spanish and English, about performance: evolution, acceptance and recognition. For the identification, screening, and inclusion of the articles the PRISMA 2020 model was used. Results: Of 838 total identified articles, 20 articles were included from the search and 7 from other sources such as citations and other websites, obtaining 27 total articles to be reviewed, which regard the evolution, acceptance and recognition. A qualitative analysis was performed. Conclusions: The APN performance arose because of demands for primary health care; several countries already have APN, providing care to inhabitants through their different specialties. APN is diverse and extensive, its professionalization must be continuous and permanent. In Mexico there is still some way to go to APN to take part in the multidisciplinary team.


Asunto(s)
Humanos , Rol de la Enfermera , Educación en Enfermería , Enfermería de Práctica Avanzada , Enfermería de Atención Primaria
3.
Psicol Reflex Crit ; 36(1): 37, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38015372

RESUMEN

BACKGROUND: Identifying the underlying mechanisms through which adverse childhood experiences affect (ACEs) the mental health of adolescents is of paramount importance for disease prevention in later stages of life. OBJECTIVE: The present study examines the relationship between ACEs and psychopathology in adolescents from northern Chile and how attachment style (abandonment anxiety and intimacy avoidance) may moderate this relationship. A total of 154 schooled adolescents aged 12 to 17 (M = 15.08, SD = 1.64) completed a series of self-report questionnaires including the Adverse Childhood Experience Questionnaire (ACEs), Experiences in Close Relationships- Relationship Structures (ECR-RS), and Youth Self Report (YSR-18). RESULTS: The data analysis was carried out using SPSS version 25, which included descriptive analysis, one-way ANOVA, and Spearman correlation analysis. To address moderation analysis, the PROCESS macro extension version 4.1 was employed. In this process, the bootstrap method was applied to construct confidence intervals, and the pick-a-point approach was used to define the levels of the moderating variable. According to the results, 80.3% of the sample experienced one or more ACEs, and 16.4% reported experiencing at least three. Furthermore, the variables under study exhibited significant correlations with each other, except for intimacy avoidance, which showed no correlation with ACEs (rho = -0.10; p = 0.273). When considering abandonment anxiety as a moderating variable, the direct effect of ACEs on externalizing symptoms showed statistically significant changes (ß = 0.60, p = 0.03). No other moderating effects were found according to the proposed models. CONCLUSION: In childhood, the accumulation of ACEs is associated with the development of psychopathology in adolescents from northern Chile, specifically with the presence of internalizing and externalizing symptoms. These findings suggest that lower levels of abandonment anxiety could mitigate the effects of ACEs on adolescent psychopathology, while higher levels of abandonment anxiety could exacerbate these effects on psychopathology.

4.
JBJS Case Connect ; 13(4)2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38015935

RESUMEN

CASE: A 61-year-old woman with lower back and radicular leg pain underwent minimally invasive spinal fusion at L5-S1. By postoperative day 6, she exhibited erythema, wound dehiscence, and necrotic changes. Although a necrotizing infection was initially suspected, multiple debridements and antibiotic therapy failed to improve her condition. The patient was eventually diagnosed with pyoderma gangrenosum (PG) and was managed with immunosuppressants and extended wound care. CONCLUSION: PG is a rare dermatosis that is often misdiagnosed, leading to inappropriate treatment, debridements, and additional complications. Prompt identification and multidisciplinary collaboration are key to preventing unnecessary interventions and achieving the best outcomes.


Asunto(s)
Piodermia Gangrenosa , Fusión Vertebral , Femenino , Humanos , Persona de Mediana Edad , Piodermia Gangrenosa/cirugía , Fusión Vertebral/efectos adversos , Inmunosupresores
5.
Bol Med Hosp Infant Mex ; 80(4): 247-252, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37703551

RESUMEN

BACKGROUND: Acute fetal distress (AFD) is a condition that requires timely diagnosis because it generates hypoxia, acidosis, and even intrauterine death. This study aimed to determine lactate and pH values in the umbilical cord in full-term newborns (NBs) with a history of AFD. METHODS: We conducted a cross-sectional study in full-term NBs of mothers with at least one perinatal, neonatal, or gasometric AFD antecedent. Neonatal morbidity was considered: if 1-min Apgar ≤ 6, or advanced neonatal maneuvers, or neonatal intensive care unit (NICU) admissions were necessary. The cutoff points were lactate > 4mmol/L and pH < 7.2. RESULTS: Of 66 NBs, 33.3% of mothers presented at least one antecedent for developing AFD; 22.7% presented hypertensive pregnancy disease, 13.6% oligohydramnios, and 63.6% other factors. Perinatally, 28.7% required advanced neonatal resuscitation maneuvers and 7.5% admission to the NICU. In the gasometry, the lactate and pH values for the neonatal morbidity of the NBs' group were 4.726 ± 1.401 and 7.293 ± 0.056, respectively, versus 2.240 ± 0.318 and 7.359 ± 0.022 (p < 0.05) for the group without associated neonatal morbidity. CONCLUSIONS: Lactate values in the umbilical cord increased by 25%, and pH decreased by one percent in NBs with a history of AFD and associated morbidity.


INTRODUCCIÓN: El sufrimiento fetal agudo (SFA) es una condición que amerita un diagnóstico oportuno debido a que genera hipoxia, acidosis e incluso la muerte intrauterina. El objetivo de este estudio fue determinar los valores de lactato y pH en cordón umbilical en recién nacidos de término con antecedente SFA. MÉTODOS: Se llevó a cabo un estudio transversal, en recién nacidos a término, de madres que tuvieron al menos un antecedente para SFA de tipo perinatal, neonatal o gasométrico. Se consideró morbilidad neonatal cuando presentaron Apgar al minuto ≤ 6, o requirieron maniobras avanzadas de reanimación neonatal, o ingreso a Unidad de Cuidados Intensivos Neonatales (UCIN). El punto de corte fue > 4 mmol/L para los valores de lactato y pH < 7.2. RESULTADOS: De un total de 66 recién nacidos, el 33.3% de las madres presentaron al menos un antecedente para desarrollar SFA; el 22.7% presentó enfermedad hipertensiva del embarazo, el 13.6%, oligohidramnios, y el 63.6%, otros factores. El 28.7% requirieron maniobras avanzadas de la reanimación neonatal y el 7.5%, el ingreso a la UCIN. En la gasometría, el valor de lactato y pH para el grupo de recién nacidos con morbilidad neonatal fue de 4.726 ± 1.401 y 7.293 ± 0.056 respectivamente, versus 2.240 ± 0.318 y 7.359 ± 0.022 (p < 0.05) para el grupo sin morbilidad neonatal asociada. CONCLUSIONES: Se observó un incremento del 25% de los valores de lactato en cordón umbilical y una disminución del 1% del pH en los recién nacidos con antecedente de SFA y morbilidad asociada.


Asunto(s)
Hipertensión , Ácido Láctico , Femenino , Embarazo , Recién Nacido , Humanos , Estudios Transversales , Sufrimiento Fetal/diagnóstico , Resucitación , Concentración de Iones de Hidrógeno
6.
Bol. méd. Hosp. Infant. Méx ; 80(4): 247-252, Jul.-Aug. 2023. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1520286

RESUMEN

Abstract Background: Acute fetal distress (AFD) is a condition that requires timely diagnosis because it generates hypoxia, acidosis, and even intrauterine death. This study aimed to determine lactate and pH values in the umbilical cord in full-term newborns (NBs) with a history of AFD. Methods: We conducted a cross-sectional study in full-term NBs of mothers with at least one perinatal, neonatal, or gasometric AFD antecedent. Neonatal morbidity was considered: if 1-min Apgar ≤ 6, or advanced neonatal maneuvers, or neonatal intensive care unit (NICU) admissions were necessary. The cutoff points were lactate > 4mmol/L and pH < 7.2. Results: Of 66 NBs, 33.3% of mothers presented at least one antecedent for developing AFD; 22.7% presented hypertensive pregnancy disease, 13.6% oligohydramnios, and 63.6% other factors. Perinatally, 28.7% required advanced neonatal resuscitation maneuvers and 7.5% admission to the NICU. In the gasometry, the lactate and pH values for the neonatal morbidity of the NBs' group were 4.726 ± 1.401 and 7.293 ± 0.056, respectively, versus 2.240 ± 0.318 and 7.359 ± 0.022 (p < 0.05) for the group without associated neonatal morbidity. Conclusions: Lactate values in the umbilical cord increased by 25%, and pH decreased by one percent in NBs with a history of AFD and associated morbidity.


Resumen Introducción: El sufrimiento fetal agudo (SFA) es una condición que amerita un diagnóstico oportuno debido a que genera hipoxia, acidosis e incluso la muerte intrauterina. El objetivo de este estudio fue determinar los valores de lactato y pH en cordón umbilical en recién nacidos de término con antecedente SFA. Métodos: Se llevó a cabo un estudio transversal, en recién nacidos a término, de madres que tuvieron al menos un antecedente para SFA de tipo perinatal, neonatal o gasométrico. Se consideró morbilidad neonatal cuando presentaron Apgar al minuto ≤ 6, o requirieron maniobras avanzadas de reanimación neonatal, o ingreso a Unidad de Cuidados Intensivos Neonatales (UCIN). El punto de corte fue > 4 mmol/L para los valores de lactato y pH < 7.2. Resultados: De un total de 66 recién nacidos, el 33.3% de las madres presentaron al menos un antecedente para desarrollar SFA; el 22.7% presentó enfermedad hipertensiva del embarazo, el 13.6%, oligohidramnios, y el 63.6%, otros factores. El 28.7% requirieron maniobras avanzadas de la reanimación neonatal y el 7.5%, el ingreso a la UCIN. En la gasometría, el valor de lactato y pH para el grupo de recién nacidos con morbilidad neonatal fue de 4.726 ± 1.401 y 7.293 ± 0.056 respectivamente, versus 2.240 ± 0.318 y 7.359 ± 0.022 (p < 0.05) para el grupo sin morbilidad neonatal asociada. Conclusiones: Se observó un incremento del 25% de los valores de lactato en cordón umbilical y una disminución del 1% del pH en los recién nacidos con antecedente de SFA y morbilidad asociada.

7.
Psicol. reflex. crit ; 36: 37, 2023. tab, graf
Artículo en Inglés | LILACS-Express | LILACS, Index Psicología - Revistas | ID: biblio-1529277

RESUMEN

Abstract Background Identifying the underlying mechanisms through which adverse childhood experiences affect (ACEs) the mental health of adolescents is of paramount importance for disease prevention in later stages of life. Objective The present study examines the relationship between ACEs and psychopathology in adolescents from northern Chile and how attachment style (abandonment anxiety and intimacy avoidance) may moderate this relationship. A total of 154 schooled adolescents aged 12 to 17 (M = 15.08, SD = 1.64) completed a series of self-report questionnaires including the Adverse Childhood Experience Questionnaire (ACEs), Experiences in Close Relationships-Relationship Structures (ECR-RS), and Youth Self Report (YSR-18). Results The data analysis was carried out using SPSS version 25, which included descriptive analysis, one-way ANOVA, and Spearman correlation analysis. To address moderation analysis, the PROCESS macro extension version 4.1 was employed. In this process, the bootstrap method was applied to construct confidence intervals, and the pick-a-point approach was used to define the levels of the moderating variable. According to the results, 80.3% of the sample experienced one or more ACEs, and 16.4% reported experiencing at least three. Furthermore, the variables under study exhibited significant correlations with each other, except for intimacy avoidance, which showed no correlation with ACEs (rho = −0.10; p = 0.273). When considering abandonment anxiety as a moderating variable, the direct effect of ACEs on externalizing symptoms showed statistically significant changes (β = 0.60, p = 0.03). No other moderating effects were found according to the proposed models. Conclusion In childhood, the accumulation of ACEs is associated with the development of psychopathology in adolescents from northern Chile, specifically with the presence of internalizing and externalizing symptoms. These findings suggest that lower levels of abandonment anxiety could mitigate the effects of ACEs on adolescent psychopathology, while higher levels of abandonment anxiety could exacerbate these effects on psychopathology.

8.
Healthcare (Basel) ; 12(1)2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38200909

RESUMEN

School and university can be stressful contexts that can become an important source of identity threats when social prejudices or stereotypes come into play. Self-affirmation interventions are key strategies for mitigating the negative consequences of identity threat. This meta-analysis aims to provide an overview of the effectiveness of self-affirmation interventions in educational settings. A peer-reviewed article search was conducted in January 2023. A total of 144 experimental studies that tested the effect of self-affirmation interventions in educational contexts among high school and university students from different social and cultural backgrounds were considered. The average effect of self-affirmation interventions was of low magnitude (dIG+ = 0.41, z = 16.01, p < 0.00), with a 95% confidence interval whose values tended to lie between 0.36 and 0.45 (SE = 0.0253). In addition, moderators such as identity threat, participants' age, and intervention procedure were found. Through a meta-analysis of the impact of self-affirmation interventions in educational contexts, this study suggests that interventions are effective, resulting in a small mean effect size. Thus, self-affirmation interventions can be considered useful, brief, and inexpensive strategies to improve general well-being and performance in educational settings.

9.
Front Genet ; 14: 1306600, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38299096

RESUMEN

Environmental pollution nowadays has not only a direct correlation with human health changes but a direct social impact. Epidemiological studies have evidenced the increased damage to human health on a daily basis because of damage to the ecological niche. Rapid urban growth and industrialized societies importantly compromise air quality, which can be assessed by a notable accumulation of air pollutants in both the gas and the particle phases. Of them, particulate matter (PM) represents a highly complex mixture of organic and inorganic compounds of the most variable size, composition, and origin. PM being one of the most complex environmental pollutants, its accumulation also varies in a temporal and spatial manner, which challenges current analytical techniques used to investigate PM interactions. Nevertheless, the characterization of the chemical composition of PM is a reliable indicator of the composition of the atmosphere, the quality of breathed air in urbanized societies, industrial zones and consequently gives support for pertinent measures to avoid serious health damage. Epigenomic damage is one of the most promising biological mechanisms of air pollution-derived carcinogenesis. Therefore, this review aims to highlight the implication of PM exposure in diverse molecular mechanisms driving human diseases by altered epigenetic regulation. The presented findings in the context of pan-organic cancer, fibrosis, neurodegeneration and metabolic diseases may provide valuable insights into the toxicity effects of PM components at the epigenomic level and may serve as biomarkers of early detection for novel targeted therapies.

10.
Rev. med. Chile ; 150(10): 1291-1298, oct. 2022. ilus, tab
Artículo en Español | LILACS | ID: biblio-1431858

RESUMEN

BACKGROUND: An informed consent is mandatory to obtain any clinical audiovisual material from patients. Although there are some documents created for this purpose, there are some barriers for their application, such as the context in which they were created, the language and download availability. AIM: To create a proposal for an informed consent form (ICF) for the capture and different uses for audiovisual material from patients. MATERIAL AND METHODS: A bibliographic search was carried out to obtain different ICFs in Spanish and English, which were subjected to a process of translation, counter-translation and fragmentation. Subsequently, a panel of experts was formed by members of the Chilean Society of Plastic Surgery with extensive experience in social networks. Delphi methodology was applied to reach a consensus about the definitive content of the ICF based on the previously selected fragments. RESULTS: ICFs available for download were identified. The panel was made up of seven Plastic Surgeons and two Delphi rounds were carried out through electronic surveys. At the end of the process, an ICF proposal was obtained for therapeutic, academic or scientific purposes and another for dissemination or education in the mass media. CONCLUSIONS: The proposed ICFs were liberated for their use among health care professionals in Chile, who could use them, provided that they are approved by the local healthcare ethics committees.


Asunto(s)
Humanos , Formularios de Consentimiento , Consentimiento Informado , Traducciones , Encuestas y Cuestionarios , Lenguaje
11.
Materials (Basel) ; 15(16)2022 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-36013655

RESUMEN

A reliable process for the formation of nanoporous ZnO films supported on amorphous quartz and (100) silicon substrates via the processing of ZnO/Zn precursor films is reported. The process is based on the sublimation mechanism of Zn implemented in a novel ZnO/Zn precursor film to produce a nanoporous film. A scanning electron microscopy analysis of the nanoporous ZnO films' surfaces revealed the presence of ZnO nano-features with round tips; in contrast, the nanoporous ZnO films supported on (100) Si substrates showed hexagonal nut-like nanostructures. The crystallite size of the nanoporous ZnO films decreased as the sublimation temperature was increased. X-ray photoelectron spectroscopy studies demonstrated that formations of oxygen vacancies were produced during the processing stages (as the main structural lattice defects in the ZnO nanoporous films). The analysis of the photoluminescence response confirmed that the active deep-level centers were also related to the oxygen vacancies generated during the thermal processing of the ZnO/Zn precursor films. Finally, a qualitative mechanism is proposed to explain the formation of nanoporous ZnO films on quartz and crystalline Si substrates. The results suggest that the substrates used have a strong influence on the nanoporous ZnO structures obtained with the Zn-sublimation-controlled process.

13.
Rev Med Chil ; 150(10): 1291-1298, 2022 Oct.
Artículo en Español | MEDLINE | ID: mdl-37358087

RESUMEN

BACKGROUND: An informed consent is mandatory to obtain any clinical audiovisual material from patients. Although there are some documents created for this purpose, there are some barriers for their application, such as the context in which they were created, the language and download availability. AIM: To create a proposal for an informed consent form (ICF) for the capture and different uses for audiovisual material from patients. MATERIAL AND METHODS: A bibliographic search was carried out to obtain different ICFs in Spanish and English, which were subjected to a process of translation, counter-translation and fragmentation. Subsequently, a panel of experts was formed by members of the Chilean Society of Plastic Surgery with extensive experience in social networks. Delphi methodology was applied to reach a consensus about the definitive content of the ICF based on the previously selected fragments. RESULTS: ICFs available for download were identified. The panel was made up of seven Plastic Surgeons and two Delphi rounds were carried out through electronic surveys. At the end of the process, an ICF proposal was obtained for therapeutic, academic or scientific purposes and another for dissemination or education in the mass media. CONCLUSIONS: The proposed ICFs were liberated for their use among health care professionals in Chile, who could use them, provided that they are approved by the local healthcare ethics committees.


Asunto(s)
Formularios de Consentimiento , Consentimiento Informado , Humanos , Lenguaje , Encuestas y Cuestionarios , Traducciones
15.
Entropy (Basel) ; 23(4)2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33916017

RESUMEN

Automatic recognition of visual objects using a deep learning approach has been successfully applied to multiple areas. However, deep learning techniques require a large amount of labeled data, which is usually expensive to obtain. An alternative is to use semi-supervised models, such as co-training, where multiple complementary views are combined using a small amount of labeled data. A simple way to associate views to visual objects is through the application of a degree of rotation or a type of filter. In this work, we propose a co-training model for visual object recognition using deep neural networks by adding layers of self-supervised neural networks as intermediate inputs to the views, where the views are diversified through the cross-entropy regularization of their outputs. Since the model merges the concepts of co-training and self-supervised learning by considering the differentiation of outputs, we called it Differential Self-Supervised Co-Training (DSSCo-Training). This paper presents some experiments using the DSSCo-Training model to well-known image datasets such as MNIST, CIFAR-100, and SVHN. The results indicate that the proposed model is competitive with the state-of-art models and shows an average relative improvement of 5% in accuracy for several datasets, despite its greater simplicity with respect to more recent approaches.

17.
Cardiol Young ; 31(4): 654-657, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33308360

RESUMEN

Dengue virus can affect the heart, with complications as bradycardia, arrhythmias, and death. We present a case of a 15-year-old patient, diagnosed 4 years before with severe idiopathic pulmonary hypertension, confirmed by catheterism, with continuous follow up. At that time, she was living in Bogotá (2640 m above sea level). Sildenafil and Macitentan were started. She was recommended to live at low altitude and she moved. The patient was transferred back to Bogota, from that place, due to flu-like symptoms and fever. Immunoglobulin M for dengue was confirmed and second-degree atrioventricular block Mobitz I with bradycardia (40 beats/minute) was documented throughout the clinical course. She recovered.


Asunto(s)
Bloqueo Atrioventricular , Dengue , Hipertensión Pulmonar , Adolescente , Arritmias Cardíacas , Niño , Dengue/complicaciones , Dengue/diagnóstico , Hipertensión Pulmonar Primaria Familiar , Femenino , Humanos , Hipertensión Pulmonar/diagnóstico , Hipertensión Pulmonar/etiología
18.
Chaos ; 30(1): 013108, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32013459

RESUMEN

We show that, in strongly chaotic dynamical systems, the average particle velocity can be calculated analytically by consideration of Brownian dynamics in a phase space, the method of images, and the use of the classical diffusion equation. The method is demonstrated on the simplified Fermi-Ulam accelerator model, which has a mixed phase space with chaotic seas, invariant tori, and Kolmogorov-Arnold-Moser islands. The calculated average velocities agree well with numerical simulations and with an earlier empirical theory.

19.
Phys Rev E ; 100(4-1): 042207, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31770867

RESUMEN

In this work we investigate how the behavior of the Shannon entropy can be used to measure the diffusion exponent of a set of initial conditions in two systems: (i) standard map and (ii) the oval billiard. We are interested in the diffusion near the main island in the phase space, where stickiness is observed. We calculate the diffusion exponent for many values of the nonlinear parameter of the standard map where the size and shape of the main island change as the parameter varies. We show that the changes of behavior in the diffusion exponent are related with the changes in the area of the main island and show that when the area of the main island is abruptly reduced, due to the destruction of invariant tori and, consequently, creation of hyperbolic and elliptic fixed points, the diffusion exponent grows.

20.
Rev. colomb. gastroenterol ; 34(3): 297-302, jul.-set. 2019. tab, graf
Artículo en Español | LILACS | ID: biblio-1042818

RESUMEN

Resumen El síndrome de Budd-Chiari es una entidad definida como la obstrucción al flujo sanguíneo en el tracto de salida hepático. Esta obstrucción se puede localizar desde las pequeñas venas hepáticas hasta la entrada de la vena cava inferior a la aurícula derecha. En la mayoría de los casos, se ocasiona por una trombosis endoluminal conocida como Budd-Chiari primario y secundario, cuando ocurre por una compresión extrínseca asociada a las lesiones que ocupan espacio como malignidad. Por tanto, los estados trombofílicos hereditarios se conocen como los principales factores de riesgo. El embarazo y el puerperio, al ser estados hipercoagulables, se pueden asociar al síndrome de Budd-Chiari, sin embargo, la prevalencia reportada en la literatura es muy variable dependiendo de la población estudiada. En Colombia no hay estudios de incidencia o prevalencia de la enfermedad; existen varios reportes de caso, pero no relacionados con el embarazo. Reportamos el caso de una paciente, que 12 semanas posparto presentó un síndrome de Budd-Chiari; además presentamos el manejo ofrecido, la evolución clínica y una revisión de la literatura de los casos asociados con el embarazo.


Abstract Budd-Chiari syndrome is defined as obstruction of hepatic blood outflow. This obstruction can be located anywhere from the small hepatic veins at the entrance of the inferior vena cava to the right atrium. Most cases are primary Budd-Chiari syndrome which is caused by endoluminal thrombosis. Secondary Budd-Chiari syndrome occurs as the result of extrinsic compression associated with space-occupying lesions such as malignant tumors. Hereditary thrombophilic states are the main risk factors, but since pregnancy and the puerperium are hypercoagulable states, they can be associated with Budd-Chiari syndrome. Nevertheless, the prevalence of this type of case in the literature varies according to the population studied. There have been no studies on the incidence or prevalence of this disease in Colombia. The small number of case reports here have not been related to pregnancy. We report the case of a patient who developed Budd-Chiari syndrome 12 weeks postpartum. Our report includes management and clinical evolution as well as a review of the literature of cases associated with pregnancy.


Asunto(s)
Humanos , Femenino , Adolescente , Periodo Posparto , Síndrome de Budd-Chiari , Trombosis , Literatura
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