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1.
Rev Gastroenterol Mex (Engl Ed) ; 89(1): 121-143, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38580493

RESUMO

INTRODUCTION: Gastroesophageal reflux disease (GERD) is very prevalent in the general population, with a broad spectrum of clinical manifestations, requiring accurate diagnosis and treatment. AIM: The aim of this expert review is to establish good clinical practice recommendations for the diagnosis and personalized treatment of GERD. METHODS: The good clinical practice recommendations were produced by a group of experts in GERD, members of the Asociación Mexicana de Gastroenterología (AMG), after carrying out an extensive review of the published literature and discussing each recommendation at a face-to-face meeting. This document does not aim to be a clinical practice guideline with the methodology such a document requires. RESULTS: Fifteen experts on GERD formulated 27 good clinical practice recommendations for recognizing the symptoms and complications of GERD, the rational use of diagnostic tests and medical treatment, the identification and management of refractory GERD, the overlap with functional disorders, endoscopic and surgical treatment, and GERD in the pregnant woman, older adult, and the obese patient. CONCLUSIONS: An accurate diagnosis of GERD is currently possible, enabling the prescription of a personalized treatment in patients with this condition. The goal of the good clinical practice recommendations by the group of experts from the AMG presented in this document is to aid both the general practitioner and specialist in the process of accurate diagnosis and treatment, in the patient with GERD.


Assuntos
Refluxo Gastroesofágico , Idoso , Feminino , Humanos , Gravidez , Endoscopia , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/terapia
2.
Rev Gastroenterol Mex (Engl Ed) ; 88(4): 404-428, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38097437

RESUMO

Fecal incontinence is the involuntary passage or the incapacity to control the release of fecal matter through the anus. It is a condition that significantly impairs quality of life in those that suffer from it, given that it affects body image, self-esteem, and interferes with everyday activities, in turn, favoring social isolation. There are no guidelines or consensus in Mexico on the topic, and so the Asociación Mexicana de Gastroenterología brought together a multidisciplinary group (gastroenterologists, neurogastroenterologists, and surgeons) to carry out the «Mexican consensus on fecal incontinence¼ and establish useful recommendations for the medical community. The present document presents the formulated recommendations in 35 statements. Fecal incontinence is known to be a frequent entity whose incidence increases as individuals age, but one that is under-recognized. The pathophysiology of incontinence is complex and multifactorial, and in most cases, there is more than one associated risk factor. Even though there is no diagnostic gold standard, the combination of tests that evaluate structure (endoanal ultrasound) and function (anorectal manometry) should be recommended in all cases. Treatment should also be multidisciplinary and general measures and drugs (lidamidine, loperamide) are recommended, as well as non-pharmacologic interventions, such as biofeedback therapy, in selected cases. Likewise, surgical treatment should be offered to selected patients and performed by experts.


Assuntos
Incontinência Fecal , Humanos , Incontinência Fecal/diagnóstico , Incontinência Fecal/terapia , Incontinência Fecal/etiologia , Consenso , México/epidemiologia , Qualidade de Vida , Loperamida/uso terapêutico
3.
Soft Matter ; 15(42): 8621-8626, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31624811

RESUMO

While important research has been focused on developing surfaces that do not wet, some textures with high-wetting resistance are familiar in other applications in which the opposite is needed. A multivalued surface, common in most fabrics or meshes, allows the invading gas-liquid interface to support relatively high imposed pressures and plays a key role in producing topographic elements that avoid wetting. Here we study experimentally and theoretically the critical pressure needed to move a liquid through a network of pores and show that, for small aperture size, wetting and leaking are typical first-order transitions, with a singular behavior at the omniphobic/omniphilic limit (θc = π/2).

4.
Rev Gastroenterol Mex (Engl Ed) ; 84(4): 472-481, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31488310

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is currently one of the main causes of chronic liver disease in Western countries, with a 25% prevalence reported in the general population worldwide. Visceral adiposity and liver fat promote a state of systemic inflammation, predisposing individuals with NAFLD to the extrahepatic pathologies of cardiovascular disease (the most common cause of death in patients with NAFLD), diabetes mellitus, chronic kidney disease, hypothyroidism, polycystic ovary syndrome, obstructive sleep apnea, and an increased risk for presenting with gastrointestinal and extraintestinal neoplasias. Different mechanisms between NAFLD and its association with extrahepatic diseases have been reported, and lipotoxicity is the main cause of inflammatory pathway activation that results in extrahepatic tissue damage.


Assuntos
Hepatopatia Gordurosa não Alcoólica/complicações , Doenças Cardiovasculares/etiologia , Doenças do Sistema Endócrino/etiologia , Humanos , Neoplasias/etiologia , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Insuficiência Renal Crônica/etiologia
5.
Int Nurs Rev ; 66(1): 104-111, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30010194

RESUMO

AIMS: To determine what social support is available in Spain to people over 65 who also dedicate hours of their time to the care of others who are older. BACKGROUND: Demographic and social changes are leading to growth of the population. The social support available to older people in the final stage of life affects their health. METHODS: A cross-sectional study was conducted involving the records of older, non-institutionalized individuals residing in Spain, obtained from the European Health Survey of 2014. The method of collecting information used in the European Survey was personal interviews assisted by a computer. RESULTS: The records of 6520 older people were studied; 40.1% of the participants studied had expressed the possibility of having three to five people available in case of a serious problem, and 83.6% reported that the rest of the people around them were very interested in what happens to them. With respect to care, only 7% of the older people studied mentioned performing care tasks. CONCLUSIONS: Social support is beneficial to older people, regardless of whether they perform care tasks, because it acts as a protective factor against problems such as loneliness, stress and depression. The profile of a primary caregiver in this age range is a married, middle-class woman with primary schooling who is caring for a first-degree relative. IMPLICATIONS FOR NURSING AND HEALTH POLICY: These data suggest that it is necessary for nurses to know about the needs of older people to implement societal measures of health promotion, prevention and education that favour social cohort. In addition, health policymakers should establish programmes that improve the social support of non-institutionalized older people.


Assuntos
Cuidadores/psicologia , Família/psicologia , Idoso Fragilizado/psicologia , Idoso Fragilizado/estatística & dados numéricos , Apoio Social , Idoso , Idoso de 80 Anos ou mais , Cuidadores/estatística & dados numéricos , Estudos Transversais , Feminino , Humanos , Masculino , Espanha , Inquéritos e Questionários
6.
ACS Appl Mater Interfaces ; 10(16): 13361-13372, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29627980

RESUMO

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.


Assuntos
Poliuretanos/química , Materiais Biocompatíveis , Sobrevivência Celular , Ouro , Nanopartículas Metálicas , Porosidade , Engenharia Tecidual , Alicerces Teciduais
7.
Nutr Metab Cardiovasc Dis ; 28(4): 393-401, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29422298

RESUMO

BACKGROUND AND AIMS: An increase in plasma branched-chain amino acids is associated with a higher risk of developing type 2 diabetes and cardiovascular diseases. However, little is known about the basal plasma amino acid concentrations in young adults. Our aim was to determine the plasma amino acid profiles of young adults and to evaluate how these profiles were modified by sex, body mass index (BMI) and insulin resistance (IR). METHODS AND RESULTS: We performed a transversal study with 608 Mexican young adults aged 19.9 ± 2.4 years who were applicants to the Universidad Autónoma de San Luis Potosí. The subjects underwent a physical examination and provided a clinical history and a blood sample for biochemical, hormonal and amino acid analyses. The women had higher levels of arginine, aspartate and serine and lower levels of α-aminoadipic acid, cysteine, isoleucine, leucine, methionine, proline, tryptophan, tyrosine, urea and valine than the men. The obese subjects had higher levels of alanine, aspartate, cysteine, ornithine, phenylalanine, proline and tyrosine and lower levels of glycine, ornithine and serine than the normal weight subjects. Subjects with IR (defined as HOMA > 2.5) had higher levels of arginine, alanine, aspartate, isoleucine, leucine, phenylalanine, proline, tyrosine, taurine and valine than the subjects without IR. Furthermore, we identified two main groups in the subjects with obesity and/or IR; one group was composed of amino acids that positively correlated with the clinical, biochemical and hormonal parameters, whereas the second group exhibited negative correlations. CONCLUSION: This study demonstrates that young adults with obesity or IR have altered amino acid profiles characterized by an increase in alanine, aspartate, proline and tyrosine and a decrease in glycine.


Assuntos
Aminoácidos/sangue , Índice de Massa Corporal , Resistência à Insulina , Obesidade Infantil/sangue , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Fatores Etários , Biomarcadores/sangue , Estudos Transversais , Feminino , Humanos , Masculino , México/epidemiologia , Estado Nutricional , Obesidade Infantil/diagnóstico , Obesidade Infantil/epidemiologia , Obesidade Infantil/fisiopatologia , Prevalência , Fatores de Risco , Fatores Sexuais , Adulto Jovem
8.
Artigo em Inglês | MEDLINE | ID: mdl-25871123

RESUMO

Isometric deformations in thin elastic films easily form ridges to connect large flat regions or facets. Depending on the forces applied or the boundary conditions imposed, these ridges can be isometric, with no stretching or "stretching ridges" when bending and stretching are required to relax the elastic energy. Here we study a simple configuration to observe the transition between an isometric ridge to the well-known stretching ridge observed in crumpled films, and obtain the parameters that determine the ridge type. Specifically, we show that the transversal size of a stretching ridge acts as a cutoff length scale: a ridge is isometric if its width is greater than this characteristic length.

10.
Oncol Lett ; 6(5): 1195-1200, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24179494

RESUMO

The forkhead box P3 (Foxp3) transcription factor is one of the most studied markers used to identify CD4+CD25+ regulatory T cells (Tregs), and has been identified as a key regulator in the development and function of Tregs. Foxp3 expression has been reported in a variety of solid human tumors, including melanoma. The aims of the present study were to analyze Foxp3 expression in B16F10 melanoma cells in vitro, to determine whether this expression was affected during tumor growth in a murine melanoma model and to correlate Foxp3 expression with CD25 expression, interleukin (IL)-2 production and tumor weight. Foxp3 expression was analyzed with quantitative (q)PCR, flow cytometry and confocal microscopy. CD25 expression was analyzed by flow cytometry, and cytokine production was measured by ELISA [IL-2, interferon (IFN)-γ, transforming growth factor (TGF)-ß and IL-10] and flow cytometry (IL-2, IFN-γ, IL-4 and IL-5). Foxp3 and CD25 expression was detected in the B16F10 cells in culture and in the intratumoral B16F10 cells. An increase in Foxp3 and CD25 expression was observed in a time-dependent manner during tumor growth at 7, 14 and 21 days. The production of the IL-2, IL-10, IFN-γ and TGF-ß cytokines was observed in the B16F10 cells and also detected in the tumoral microenvironment during tumor growth (7, 14 and 21 days). An increase in IL-2 and IL-10 production was observed, whereas IFN-γ production decreased in a time-dependent manner. The production of tumor necrosis factor (TNF)-α was not observed in culture, but was detected during tumor growth, whereas the production of IL-4 and IL-5 was not detected. These data showed a positive correlation between the expression of Foxp3, CD25 and IL-2 and tumor weight in murine melanoma. From these data, it may be suggested that Foxp3 participates in melanoma growth, the modulation of the IL-2, IFN-γ and TNF-α cytokines and CD25 expression, and that it also plays a possible role in immunosuppression.

11.
Phys Rev Lett ; 111(1): 014301, 2013 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-23863002

RESUMO

We address the partial wetting of liquid drops on ultrathin solid sheets resting on a deformable foundation. Considering the membrane limit of sheets that can relax compression through wrinkling at negligible energetic cost, we revisit the classical theory for the contact of liquid drops on solids. Our calculations and experiments show that the liquid-solid-vapor contact angle is modified from the Young angle, even though the elastic bulk modulus (E) of the sheet is so large that the ratio between the surface tension γ and E is of molecular size. This finding indicates a new elastocapillary phenomenon that stems from the high bendability of very thin elastic sheets rather than from material softness. We also show that the size of the wrinkle pattern that emerges in the sheet is fully predictable, thus resolving a puzzle in modeling "drop-on-a-floating-sheet" experiments and enabling a quantitative, calibration-free use of this setup for the metrology of ultrathin films.

12.
Rev. chil. radiol ; 19(4): 156-164, 2013. ilus, tab, graf
Artigo em Espanhol | LILACS | ID: lil-701725

RESUMO

Multiple sclerosis (MS) is a common demyelinating disease that involves the central nervous system causing focal lesions in the brain and spinal cord causing diverse neurological development deficits, many of them severe and irreversible, affecting and invaliding a large percentage of young productive-aged patients. MRI exams have improved diagnostic capability compared to computed tomography, but in this decade the development of new magnets, coils and software have allowed the development of quantitative neuroradiology which achieves the evaluation of parameters such as total brain volume, of each of its structures, as well as semi-automated or automated counting of the lesion load, allowing better monitoring of each individual patient in relation to a particular event such as a new neurological deficit in an outbreak of the disease, a previously undetected cognitive impairment or in related to a given treatment. We will show our local experience using the FreeSurfer software in our habitual practice, as well as other post-processing software, this being the first experience of its use in multiple sclerosis published in our country.


La esclerosis múltiple (EM) es una frecuente enfermedad desmielinizante que afecta el sistema nervioso central produciendo lesiones focales a nivel cerebral y medular que condicionan diversos déficit neurológicos evolutivos, muchos de ellos severos e irreversibles, afectando e invalidando un gran porcentaje de pacientes jóvenes en edad productiva. El estudio con resonancia magnética mejoró la capacidad diagnóstica respecto a la tomografía computada, pero en esta década el desarrollo de nuevos magnetos, bobinas y software han permitido desarrollar la neurorradiología cuantitativa que logra evaluar parámetros como el volumen cerebral global, de cada una de sus estructuras así como el recuento semi o automatizado de la carga lesional, lo que permite el mejor seguimiento de cada paciente individual en relación a un evento determinado como un nuevo déficit neurológico dentro de un brote de la enfermedad, un deterioro cognitivo no detectado previamente o en relación a un tratamiento determinado. Mostraremos nuestra experiencia local utilizando el software freesurfer en nuestra práctica habitual, así como otro software de postproceso, siendo la primera experiencia de su uso en esclerosis múltiple publicada en nuestro país.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/patologia , Esclerose Múltipla/diagnóstico por imagem , Tamanho do Órgão , Atrofia
13.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(6 Pt 2): 066115, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23005170

RESUMO

The wrinkled geometry of thin films is known to vary appreciably as the applied stresses exceed their buckling threshold. Here we derive and analyze a minimal, nonperturbative set of equations that captures the continuous evolution of radial wrinkles in the simplest axisymmetric geometry from threshold to the far-from-threshold limit, where the compressive stress collapses. This description of the growth of wrinkles is different from the traditional post-buckling approach and is expected to be valid for highly bendable sheets. Numerical analysis of our model predicts two surprising results. First, the number of wrinkles scales anomalously with the thickness of the sheet and the exerted load, in apparent contradiction with previous predictions. Second, there exists an invariant quantity that characterizes the mutual variation of the amplitude and number of wrinkles from threshold to the far-from-threshold regime.


Assuntos
Membranas Artificiais , Modelos Teóricos , Simulação por Computador , Módulo de Elasticidade , Estresse Mecânico , Propriedades de Superfície
14.
Public Health ; 126(6): 535-40, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22546507

RESUMO

OBJECTIVE: Increasing overweight and obesity rates in Mexico have been associated with increases in mortality from cardiovascular disease (CVD). This study assessed changes in body mass index (BMI) and body weight over 1 year, and explored whether these were associated with changes in CVD risk factors of blood pressure and fasting glucose in a cohort of young Mexican adults. STUDY DESIGN: Longitudinal data were obtained from a cohort of young Mexican adults applying to college. METHODS: Data were collected from college applicants for the 2008 academic year who re-applied in 2009. In total, 795 college applicants aged 18-20 years, of both sexes (48% males and 52% females), were included in the study. The screen included height, weight, and systolic (SBP) and diastolic (DBP) blood pressure measurements plus a blood draw following an overnight fast for fasting glucose. RESULTS: At baseline, 31.8% of the participants were overweight or obese. The mean 1-year change in body weight and BMI were 0.80 kg and 0.35 kg/m(2), respectively. One-year changes in body weight and BMI were associated with increased SBP and DBP for both men and women (P < 0.05), independent of baseline BMI. A weight gain of 5% or more was positively associated with increases in blood pressure among women (P < 0.05), but not among men. A weight loss of 5% or more was associated with reductions in SBP among women. CONCLUSIONS: One-year changes in weight were associated with changes in blood pressure.


Assuntos
Pressão Sanguínea , Peso Corporal , Adulto , Glicemia , Índice de Massa Corporal , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , México/epidemiologia , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Fatores de Risco , Aumento de Peso , Redução de Peso , Adulto Jovem
16.
Phys Rev Lett ; 104(18): 187801, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-20482210

RESUMO

Thin fluid films can have surprising behavior depending on the boundary conditions enforced, the energy input and the specific Reynolds number of the fluid motion. Here we study the equations of motion for a thin fluid film with a free boundary and its other interface in contact with a solid wall. Although shear dissipation increases for thinner layers and the motion can generally be described in the limit as viscous, inertial modes can always be excited for a sufficiently high input of energy. We derive the minimal set of equations containing inertial effects in this strongly dissipative regime.

17.
Phys Rev Lett ; 104(12): 126402, 2010 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-20366553

RESUMO

We demonstrate the creation of vortices in a macroscopically occupied polariton state formed in a semiconductor microcavity. A weak external laser beam carrying orbital angular momentum (OAM) is used to imprint a vortex on the condensate arising from the polariton optical parametric oscillator (OPO). The vortex core radius is found to decrease with increasing pump power, and is determined by polariton-polariton interactions. As a result of OAM conservation in the parametric scattering process, the excitation consists of a vortex in the signal and a corresponding antivortex in the idler of the OPO. The experimental results are in good agreement with a theoretical model of a vortex in the polariton OPO.

18.
Enferm Infecc Microbiol Clin ; 25(7): 446-66, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17692213

RESUMO

In recent years, an increment of infections caused by gram-positive cocci has been documented in nosocomial and hospital-acquired-infections. In diverse countries, a rapid development of resistance to common antibiotics against gram-positive cocci has been observed. This situation is exceptional in Spain but our country might be affected in the near future. New antimicrobials active against these multi-drug resistant pathogens are nowadays available. It is essential to improve our current knowledge about pharmacokinetic properties of traditional and new antimicrobials to maximize its effectiveness and to minimize toxicity. These issues are even more important in critically ill patients because inadequate empirical therapy is associated with therapeutic failure and a poor outcome. Experts representing two scientific societies (Grupo de estudio de Infecciones en el Paciente Crítico de la SEIMC and Grupo de trabajo de Enfermedades Infecciosas de la SEMICYUC) have elaborated a consensus document based on the current scientific evidence to summarize recommendations for the treatment of serious infections caused by gram-positive cocci in critically ill patients.


Assuntos
Antibacterianos/uso terapêutico , Cuidados Críticos/normas , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Cocos Gram-Positivos/efeitos dos fármacos , Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Antibacterianos/farmacocinética , Bacteriemia/tratamento farmacológico , Bacteriemia/etiologia , Bacteriemia/microbiologia , Cateterismo/efeitos adversos , Infecções do Sistema Nervoso Central/tratamento farmacológico , Infecções do Sistema Nervoso Central/microbiologia , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Endocardite Bacteriana/tratamento farmacológico , Endocardite Bacteriana/microbiologia , Medicina Baseada em Evidências , Humanos , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/microbiologia , Infecções dos Tecidos Moles/tratamento farmacológico , Infecções dos Tecidos Moles/microbiologia
19.
Med Intensiva ; 31(6): 294-317, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17663956

RESUMO

In recent years, an increment of infections caused by gram-positive cocci has been documented in nosocomial and hospital-acquired infections. In diverse countries, a rapid development of resistance to common antibiotics against gram-positive cocci has been observed. This situation is exceptional in Spain but our country might be affected in the near future. New antimicrobials active against these multi-drug resistant pathogens are nowadays available. It is essential to improve our current knowledge about pharmacokinetic properties of traditional and new antimicrobials to maximize its effectiveness and to minimize toxicity. These issues are even more important in critically ill patients because inadequate empirical therapy is associated with therapeutic failure and a poor outcome. Experts representing two scientific societies (Grupo de estudio de Infecciones en el Paciente Critico de la SEIMC and Grupo de trabajo de Enfermedades Infecciosas de la SEMICYUC) have elaborated a consensus document based on the current scientific evidence to summarize recommendations for the treatment of serious infections caused by gram-positive cocci in critically ill patients.


Assuntos
Antibacterianos/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Antibacterianos/farmacologia , Bacteriemia/tratamento farmacológico , Bacteriemia/etiologia , Cateterismo/efeitos adversos , Infecções Bacterianas do Sistema Nervoso Central/tratamento farmacológico , Infecções Comunitárias Adquiridas/tratamento farmacológico , Estado Terminal , Infecção Hospitalar/tratamento farmacológico , Endocardite Bacteriana/tratamento farmacológico , Humanos , Pneumonia Bacteriana/tratamento farmacológico , Infecções dos Tecidos Moles/tratamento farmacológico
20.
Phys Rev E Stat Nonlin Soft Matter Phys ; 75(2 Pt 2): 026108, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17358395

RESUMO

The complex behavior that occurs when traffic lights are synchronized is studied. Two strategies are considered: all lights in phase, and a "green wave" with a propagating green signal. It is found that traffic variables such as traveling time, velocity, and fuel consumption, near resonance, follow critical scaling laws. For the green wave, it is shown that time and velocity scaling laws hold even for random separation between traffic lights. These results suggest the concept of transient resonances, which can be induced by adaptively changing the phase of traffic lights. This may be important to consider when designing strategies for traffic control in cities, where short trajectories, and thus transient solutions, are likely to be relevant.

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