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natural Connectivity of Complex networks

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Chinese Physics Letters 2010年第7期27卷 295-298页

作者：吴俊 mauricio Barahona 谭跃进邓宏钟 College of Information Systems and Management National University of Defense Technology Changsha 410073 Institute for Mathematical Sciences Imperial College London London SW7 2PG United Kingdom Department of Bioengineering Imperial College London London SW7 2AZ United Kingdom

The concept of natural connectivity is reported as a robustness measure of complex networks. The natural connectivity has a clear physical meaning and a simple mathematical formulation. It is shown that the natural connectivity can be derived mathematically from the graph spectrum as an average eigenvalue and that it changes strictly monotonically with the addition or deletion of edges. By comparing the natural connectivity with other typical robustness measures within a scenario of edge elimination, it is demonstrated that the naturM connectivity has an acute discrimination which agrees with our intuition.

关键词： Measurement Mathematics

Corrosion Behavior of API 5L X52 Steel under High Concentrations of H₂S/CO₂ Gases

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Materials Sciences and Applications 2016年第10期7卷 623-643页

作者： Mónica Jazmín Hernández Gayosso Gerardo Zavala Olivares Saúl Bautista Fragoso Gabriel Ernesto Blanco del Valle Daniel mauricio Godínez Oidor Víctor Ángel Rodríguez Gómez Instituto Mexicano del Petróleo Eje Central Lázaro Cárdenas Norte 152 San Bartolo Atepehuacan Gustavo A. Madero Ciudad de México México Pemex Exploración Producción Carretera Carmen-Puerto Real Km 4.5 Colonia Renovación Edificio Kaxan Campeche México

In the present work, the susceptibility of API 5L X52 steel to corrosion processes was evaluated in the presence of high contents of hydrogen sulfide and carbon dioxide. Gravimetric tests and surface analyses were carried out to establish both the corrosion rate and damage type exhibited by the metal. The obtained results indicate that the hydrogen sulfide is the most active gas in the corrosion processes that took place, quite above carbon dioxide. The main observed corrosion products were iron sulfides and the typical damage associated with hydrogen sulfide presence was Sulfide Stress Cracking (SSC). The surface damage evidences the presence of cracks with considerable magnitude and metal loss as consequences of the corrosion processes. Likewise, the presence of oxygen in the system modifies the displayed corrosion type, where corrosion products such as iron oxides and reduction in the number and extent of cracks are observed. On the other hand, the addition of a film-forming corrosion inhibitor based on modified imidazolines eliminates completely the development of cracks, although under certain test conditions, it can favor localized pitting corrosion.

关键词： H2S Corrosion Cracking Corrosion Inhibition

Modulation of gastric accommodation by duodenal nutrients

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World Journal of Gastroenterology 2005年第31期11卷 4848-4851页

作者： mauricio Carrasco fernando Azpiroz Juan-R. Malagelada Digestive System Research Unit

AIM： To determine the relative potency and contribution of intestinal nutrients to net gastric accommodative relaxation and conscious perception. METHODS： In 12 healthy subjects, we randomly tested duodenal loads of lipids and carbohydrates （12 mL administered in 4 rain） at various caloric concentrations （0.0125-0.8 kcal/mL） separated by 12-24 rain wash-out periods of saline infusion. Maximal gastric relaxation was induced at the end of each experiment by i.v glucagon （5 μg/kg）, as reference. The reflex gastric response was measured by a barostat, and symptom perception by a 0-6 score questionnaire. RESULTS： Upids induced a dose-response gastric relaxation with a steep and early rise. Maximal effect （179±42 mL relaxation） reached at a relatively low concentration （0.2 kcal/mL）, maximal lipid-induced relaxation was 61±6% of the glucagon effect. By contrast, duodenal infusion of carbohydrates induced weaker relaxation that became significant only at the high end of the physiological concentration range （65±14 ml with 0.8 kcal/mL）. Intestinal nutrient loads, either of lipid or carbohydrates, did not induce significant changes in perception （0.6±0.4 and 0.1±0.4 score increase for the highest concentrations, respectively）. COnCLUSIOn： Chyme entering the small bowel induces nutrient-spedfic gastric relaxatory reflexes by a physiologically saturable mechanism. normally, neither the intestinal nutrient load nor the gastric accommodative response is perceived.

关键词： Gastric accommodation Enterogastric reflex Postprandial symptoms Intestinal nutrients Gastric relaxation Gastric barostat Gut perception

Glucocorticosteroid therapy in inflammatory bowel diseases: From clinical practice to molecular biology

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World Journal of Gastroenterology 2017年第36期23卷 6628-6638页

作者： Karen Dubois-Camacho Payton A Ottum Daniel Franco-Munoz Marjorie De la Fuente Alejandro Torres-Riquelme David Díaz-Jiménez mauricio Olivares-Morales Gonzalo Astudillo Rodrigo Quera Marcela A Hermoso Innate Immunity Laboratory Immunology ProgramInstitute of Biomedical SciencesFaculty of MedicineUniversidad de Chile neuroimmunology Laboratory Immunology ProgramInstitute of Biomedical SciencesFaculty of MedicineUniversidad de Chile Division of Research Clínica Las Condes Gastroenterology Department Inflammatory Bowel Disease ProgramClínica Las Condes

Inflammatory bowel diseases(IBDs),such as ulcerative colitis and Crohn's disease,are chronic pathologies associated with a deregulated immune response in the intestinal mucosa,and they are triggered by environmental factors in genetically susceptible *** glucocorticoids(GCs)are widely used as anti-inflammatory therapy in *** the past,patients with moderate or severe states of inflammation received GCs as a first line therapy with an important effectiveness in terms of reduction of the disease activity and the induction of ***,this treatment often results in detrimental side *** downside drove the development of second generation GCs and more precise(non-systemic)drugdelivery *** clinical trials show that most of these new treatments have similar effectiveness to first generation GCs with fewer adverse *** remaining challenge in successful treatment of IBDs concerns the refractoriness and dependency that some patients encounter during GCs treatment.A deeper understanding of the molecular mechanisms underlying GC response is key to personalizing drug choice for IBDs patients to optimize their response to *** this review,we examine the clinical characteristics of treatment with GCs,followed by an in depth analysis of the proposed molecular mechanisms involved in its resistance and dependence associated with *** thorough analysis of current clinical and biomedical literature may help guide physicians in determining a course of treatment for IBDs patients and identifies important areas needing further study.

关键词： Inflammatory bowel diseases Ulcerative colitis Crohn's disease Glucocorticoid dependence Glucocorticoid resistance

True grit: ingestion of small stone particles by hummingbirds in West Mexico

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Avian Research 2021年第4期12卷 739-749页

作者： Omar Maya-García mauricio Ortega-Flores Jorge E.Schondube Posgrado en Ciencias Biológicas Unidad de PosgradoCoordinación del Posgrado en Ciencias BiológicasUniversidad Nacional Autónoma de MéxicoEdificio D1er pisoCircuito de PosgradosCiudad UniversitariaDel.CoyoacánC.P.04510 México D.F.Mexico Laboratorio de Ecología Funcional Instituto de Investigaciones en Ecosistemas y SustentabilidadUniversidad Nacional Autónoma de MéxicoAntigua Carretera a Pátzcuaro No.8701Col.Ex Hacienda de San Joséde la HuertaC.P.58190 MoreliaMichoacánMexico

Background: Grit is used by birds mainly for grinding hard food items but can also serve a nutritional role as a source of minerals. Ingestion of grit by birds has been documented primarily in species that feed on seeds and *** feeding mainly on nectar and small arthropods, hummingbirds also ingest grit, but why they do so is unclear. We quantified the number of grit particles in the stomachs of six species of hummingbirds during an annual cycle in a seasonal ecosystem of West ***: We compared the number of grit particles in the stomachs of different hummingbird species(Mexican Violetear Colibri thalassinus, Amethyst-throated Mountaingem Lampornis amethystinus, White-eared Hummingbird Basilinna leucotis, Rivoli's Hummingbird Eugenes fulgens, Broad-tailed Hummingbird Selasphorus platycercus, and Rufous Hummingbird S. rufus), and between sex and age categories during the different seasons of a year. To deter-mine if grit was used to grind ingested arthropods, we examined the relationships between the number of grit parti-cles, the biomass of arthropods ingested, and their chitin ***: Although species did not differ in the number of grit particles in their stomachs, we found that grit was mostly ingested by female individuals, with only one male of one species(Mexican Violetear) presenting grit in its stomach. We also found that female hummingbirds had grit in their stomachs during the rainy and the cold-dry season(June-February) but not during the warm-dry season(March-May). Our analyses revealed no relationship between the number of grit particles and the amount of ingested arthropods and arthropod chitin content. However,high grit consumption was related to wasp ingestion on Mexican ***: Our results indicate that grit is used mainly by female hummingbirds. The seasonal variation in the ingestion of grit by female individuals suggests that it can be used to meet mineral requirements related to breed-ing;how

关键词： Arthropod chitin content Arthropod digestion Breeding season Mineral nutritional requirements

ST Elevation Myocardial Infarction in the elderly

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Journal of Geriatric Cardiology 2012年第2期9卷 108-114页

作者： Marcelo Franken Amit nussbacher Alberto Liberman mauricio Wajngarten InCOR Heart Institute University of Sao Paulo Medical School Av. Dr. Endas Carvalho de Aguiar 44-05403-000 S6o Paulo Brasil PUC- Campinas Medical School Rodovia Dom Pedro I Ion 136 Parque das Universidades Campinas (SP) CEP13086-900 Brasil

Acute coronary syndromes （ACS） are the leading causes of death in the elderly. The suspicion and diagnosis of ACS in this age group is more difficult, since typical angina is less frequent. The morbidity and mortality is greater in older age patients presenting ACS. Despite the higher prevalence and greater risk, elderly patients are underrepresented in major clinical trials fi：om which evidence based recommendations are formulated. The authors describe, in this article, the challenges in the diagnosis and management of ST elevation myocardial infarction in the elderly, and discuss the available evidence.

关键词： Myocardial Infarction Acute coronary syndromes Elderly people Management

The Difficult Airway: A new Simplified Approach to an Old Complex Problem

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Open Journal of Anesthesiology 2017年第8期7卷 210-233页

作者： Iván mauricio Alvarado Arteaga Department of Anesthesiology Hospital de San Jose Bogotá Colombia

Difficult airway situations are a major cause of morbidity, mortality and malpractice claims in anesthetic practice and other critical care settings. Although infrequent, they are serious and complex situations where many variables interact. Among these variables, quick and accurate rescuer decision-making is a major outcome determinant. Emerging evidence, recent advances in technology and development of new devices have provided new tools to deal with the problem, but still, basic underlying principles of management remain. Based on the available evidence and expert consensus, multiple guidelines and algorithms have been published, but they may have limited applicability, contain confusing and ambiguous recommendations or address very specific clinical situations. This narrative review attempts to summarize, organize and consolidate current trends and supported recommendations of the updated guidelines in one practical, concise and unified guide, proposing a simple, intuitive and novel algorithm.

关键词： Anesthesia Airway Management Airway Obstruction Intubation-Intratracheal Pulmonary Ventilation Guideline Algorithms

Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis

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World Journal of Gastroenterology 2016年第48期22卷 10545-10556页

作者： Gloria Segarra Belén Cortina María Dolores mauricio Susana novella Paloma Lluch Javier navarrete-navarro Inmaculada noguera Pascual Medina Department of Physiology University of Valencia and Institute of Health Research INCLIVAHospital Clínico Universitario Valencia Department of Gastroenterology and Hepatology and Institute of Health Research InCLIVA Hospital Clínico Universitario Valencia

AIM To evaluate the effects of asymmetric dimethylarginine(ADMA) in renal arteries from portal hypertensive and cirrhotic *** Rat renal arteries from Sham(n = 15), pre-hepatic portal hypertension(PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis(BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA(10-6-10-3 mol/L), an endogenous inhibitor of nitric oxide(nO) synthase. Concentration-response curves to acetylcholine(1 × 10-9^(-3) × 10^(-6) mol/L) were determined in precontractedrenal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein expression and activity of dimethylarginine dimethylaminohydrolase(DDAH), an enzyme that catabolizes ADMA. RESULTS In renal arteries precontracted with norepinephrine, ADMA caused endothelium-dependent contractions. The pD 2 values to ADMA were similar in the Sham and PPVL groups(4.20 ± 0.08 and 4.11 ± 0.09, P > 0.05, respectively), but were lower than those of the BDL group(4.79 ± 0.16, P ne-induced endothelium-dependent relaxation that did not differ, in terms of p D2 and maximal relaxation, among the 3 groups studied. Treatment with ADMA(3 × 10^(-4) mol/L) inhibited acetylcholine-induced relaxation in the 3 groups, but the inhibition was higher(P n the BDL group compared with that for the Sham and PPVL groups. The m RnA and protein expression of DDAH-1 were similar in kidneys from the three groups. Conversely, DDAH-2 expression was increased(P n PPVL and further enhanced(P n the BDL group. However, renal DDAH activity was significantly decreased in the BDL group. COnCLUSIOn Cirrhosis increased the inhibitory effect of ADMA on basal- and induced-release of nO in renal arteries, and decreased DDAH activity in the kidney.

关键词： Portal hypertension Cirrhosis nitric oxide Asymmetric dimethylarginine nitric oxide inhibitors Dimethylarginine dimethylaminohydrolase

On/Off-Line Prediction Applied to Job Scheduling on non-Dedicated nOWs

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Journal of Computer Science & Technology 2011年第1期26卷 99-116页

作者： mauricio Hanzich Porfidio Hernandez Francesc Gine Francesc Solsona Josep L.Lerida Department of Computer Application in Science and Engineering Barcelona Supercomputing CenterBarcelonaSpain Department of Computer Architecture & Operating Systems Autonomous University of BarcelonaBarcelonaSpain Department of Computer Science University of LleidaLleidaSpain

This paper proposes a prediction engine designed for non-dedicated clusters, which is able to estimate the turnaround time for parallel applications, even in the presence of serial workload of the workstation owner. The prediction engine can be configured to work with three different estimation kernels： a Historical kernel, a Simulation kernel based on analytical models and an integration of both, named Hybrid kernel. These estimation proposals were integrated into a scheduling system, named CISnE, which can be executed in an on-line or off-line mode. The accuracy of the proposed estimation methods was evaluated in relation to different job scheduling policies in a real and a simulated cluster environment. In both environments, we observed that the Hybrid system gives the best results because it combines the ability of a simulation engine to capture the dynamism of a non-dedicated environment together with the accuracy of the historical methods to estimate the application runtime considering the state of the resources.

关键词： prediction method non-dedicated cluster cluster computing job scheduling simulation