21 research outputs found
Diseño y simulación de un convertidor CD-CD tipo Full-Bridge dual de baja potencia
No full textResumen – En el presente trabajo se muestra el diseño de un convertidor CD-CD aislado de 2KW de potencia tipo puente completo (Full-Bridge) dual con 48VDC de entrada a 310VDC en la salida, que se usará en la implementación de un inversor trifásico. De igual forma se presenta los resultados de la simulación del convertidor, los resultados permiten adelantar que la elección de la topología cumplirá con los parámetros elegidos para una carga de 2.KW.Público en genera
Cerebral blood flow, frontal lobe oxygenation and intra-arterial blood pressure during sprint exercise in normoxia and severe acute hypoxia in humans
No full textCerebral blood flow (CBF) is regulated to secure brain O2 delivery while simultaneously avoiding hyperperfusion; however, both requisites may conflict during sprint exercise. To determine whether brain O2 delivery or CBF is prioritized, young men performed sprint exercise in normoxia and hypoxia (PIO2 = 73 mmHg). During the sprints, cardiac output increased to ∼22 L min(-1), mean arterial pressure to ∼131 mmHg and peak systolic blood pressure ranged between 200 and 304 mmHg. Middle-cerebral artery velocity (MCAv) increased to peak values (∼16%) after 7.5 s and decreased to pre-exercise values towards the end of the sprint. When the sprints in normoxia were preceded by a reduced PETCO2, CBF and frontal lobe oxygenation decreased in parallel ( r = 0.93, P < 0.01). In hypoxia, MCAv was increased by 25%, due to a 26% greater vascular conductance, despite 4-6 mmHg lower PaCO2 in hypoxia than normoxia. This vasodilation fully accounted for the 22 % lower CaO2 in hypoxia, leading to a similar brain O2 delivery during the sprints regardless of PIO2. In conclusion, when a conflict exists between preserving brain O2 delivery or restraining CBF to avoid potential damage by an elevated perfusion pressure, the priority is given to brain O2 delivery
Cervical human papillomavirus infection in Mexican women with systemic lupus erythematosus or rheumatoid arthritis
No full textCervical human papillomavirus (HPV+) infection is associated with an increased risk of cervical dysplasia. Although the frequency of HPV+ in systemic lupus erythematosus (SLE) has been investigated in some races its prevalence in Hispanic women is still unknown. This cross-sectional study evaluated the prevalence of cervical HPV+ in Mexican women with SLE (n = 34) or rheumatoid arthritis (RA) (n = 43) and in healthy controls (n = 146). These women were interviewed about risk factors for sexually transmitted infections and cervical cytology analysis was performed. HPV+ viral types were identified using PCR: HPV+ was observed in 14.7% of SLE, 27.9% of RA and 30.8% of controls. High-risk HPV types were observed in 11.7% of women with SLE, 27.9% of women with RA, and in 26% of the controls. High-risk viral types 58, 35 and 18 were the most frequently identified in SLE. Two women with SLE had a high-grade squamous intraepithelial lesion and one had cervical cancer. An association was observed between methotrexate utilization, longer duration of therapy with prednisone, and HPV+ in RA or SLE. Thus, there is a high prevalence of cervical HPV infection in Mexican women with SLE or RA, and physicians must be vigilant in preventing the development of cervical dysplasia. Zapotitlán 2011 The Author(s)
Resting metabolic rate is increased in hypertensive patients with overweight or obesity: Potential mechanisms
No full textThe purpose of this investigation was to determine whether differences in body composition, pharmacological treatment, and physical activity explain the increased resting metabolic rate (RMR) and impaired insulin sensitivity in hypertension. Resting blood pressure, RMR (indirect calorimetry), body composition (dual-energy X-ray absorptiometry), physical activity (accelerometry), maximal oxygen uptake (VO2max) (ergospirometry), and insulin sensitivity (Matsuda index) were measured in 174 patients (88 men and 86 women; 20–68 years) with overweight or obesity. Hypertension (HTA) was present in 51 men (58%) and 42 women (49%) (p =.29). RMR was 6.9% higher in hypertensives than normotensives (1777 ± 386 and 1663 ± 383 kcal d−1, p =.044). The double product (systolic blood pressure × heart rate) was 18% higher in hypertensive than normotensive patients (p <.001). The observed differences in absolute RMR were non-significant after adjusting for total lean mass and total fat mass (estimated means: 1702 kcal d−1, CI: 1656–1750; and 1660 kcal d−1, CI: 1611–1710 kcal d−1, for the hypertensive and normotensive groups, respectively, p =.19, HTA × sex interaction p =.37). Lean mass, the double product, and age were the variables with the higher predictive value of RMR in hypertensive patients. Insulin sensitivity was lower in hypertensive than in normotensive patients, but these differences disappeared after accounting for physical activity and VO2max. In summary, hypertension is associated with increased RMR and reduced insulin sensitivity. The increased RMR is explained by an elevated myocardial oxygen consumption due to an increased resting double product, combined with differences in body composition between hypertensive and normotensive subjects.147014611,3834,645Q1Q1SCIE11,
Correction: Epidemiology and outcomes of early-onset AKI in COVID-19-related ARDS in comparison with non-COVID-19-related ARDS: insights from two prospective global cohort studies (Critical Care, (2023), 27, 1, (3), 10.1186/s13054-022-04294-5)
No full textFollowing publication of the original article [1], the authors identified that the collaborating authors part of the collaborating author group CCCC Consortium was missing. The collaborating author group is available and included as Additional file 1 in this article
Seguimiento a la gerencia para proyectos de vías terciarias en Colombia valorando alcance, tiempo y costo, basados en el PMBOK®
Get PDFTrabajo de investigaciónCon el el proceso y consolidación de la paz en el gobierno de Juan Manuel Santos, las partes interesadas propusieron invertir en los municipios en el mantenimiento de las vías terciarias el objetivo mejorar la transitabilidad. proyectos de conservación que se desarrollara hasta el año 2030, la elaboración de la guía para seguimiento a la gerencia en etapas de planeación y ejecución estableciendo criterios en alcance tiempo y costo con lineamientos del PMBOK con con la finalidad de alcanzar el éxito en alcance tiempo y costo.EspecializaciónEspecialista en Gerencia de Obras CivilesINTRODUCCIÓN
1. GENERALIDADES
2. MARCO DE REFERENCIA
3. MARCO JURÍDICO
4. ESTADO DEL ARTE 5. METODOLOGIA
6. METODOLOGIA Y DESARROLLO DE LA INVESTIGACION
7. ELABORACION DE LA GUIA DE SEGUIMIENTO A LA GERENCIA ALCANCE, TIEMPO Y COSTO
8. CONCLUSIONES
9. RECOMENDACIONES
10. BIBLIOGRAFÍA
11. ANEXO
Role of chemerin, a novel adipochemokine, in the human microvascular endothelial cell (HMEC)-1 line
Get PDFChemerin is a newly identified adipokine and exerts its functional effects by
binding to its natural GPCR, known as CMKLR1. Chemerin is highly expressed in
the adipose tissue and in lower levels in other body tissues; and is known to play an
important role in adipocyte differentiation and metabolism. Chemerin circulates at
the normal physiological concentrations of approximately 3-4nM in humans, and
circulating chemerin levels positively correlate with various facets of metabolic
abnormalities; such as insulin resistance, type 2 diabetes, high triglycerides,
hypertension, and associated risks of development of diseases of cardiovascular
system. Endothelial Cells (ECs) line the vasculature of the entire circulatory system
and form a direct contact with the bloodstream. In this project, the role of chemerin
in EC biology was proposed, and was studied in terms of activation of important
signalling Mitogen-activated Protein Kinases (MAPKs) including Extracellular
signal-regulated Kinase (ERK) 1/2, ERK5, p38, Stress-activated Protein Kinase/c-
Jun NH2-terminal Kinase (SAPK/JNK); and Akt/Protein Kinase B (PKB) and
Adenosine Monophosphate Protein Kinase (AMPK)-α in a time- and concentrationdependent
manners. These signalling kinases regulate the activity of different
transcription factors which then regulate the expression of different genes. Chemerin
increased the expression of Hypoxia-inducible Factor (HIF)-1α, a hypoxia-inducible
transcription factor which is known to regulate the Vascular Endothelial Growth
Factor (VEGF) gene expression. Interestingly, VEGF165, the most potent
angiogenic isoform of VEGF protein expression was down-regulated by chemerin in
a concentration-dependent manner; whereas, chemerin upregulated the protein
expression of VEGF165b, an opposite anti-angiogenic counterpart of VEGF165.
Chemerin mediated EC proliferation, migration and capillary tube formation; which
are the key processes implicated in the process of normal and pathological
angiogenesis. Chemerin altered the protein expression levels of Cell Adhesion
Molecules (CAMs) including E-selectin, ICAM-1 and VCAM-1 – increased the
activity of Nuclear Factor (NF)–kappa (κ) B pathway – and encouraged Endothelial-
Monocyte cell adhesion in a concentration-dependent manner. Nitric Oxide (NO),
not only keeps the vascular health in check by downregulating the expression levels
of adhesion molecules, but also acts as a potent vasodilator. Endothelial Nitric Oxide
Synthase (eNOS), an enzyme constitutively expressed in the endothelial cells
regulates the production of NO in the endothelium. Chemerin increased eNOS
activity by causing eNOS phosphorylation at Ser1177, and dephosphorylating at
Thr495 phosphorylation sites. Chemerin increased the protein expression of nonconstitutively
expressed enzyme, inducible Nitric Oxide Synthase (iNOS), which is
mainly induced during injury or inflammation and is known to produce 100- to
1000-times more NO compared to that of eNOS. However, interestingly, chemerin
failed to show any significant changes in the amounts of combined nitrite and nitrate
(NOx) levels in HMEC-1 cells; whereas, nitrite (NO2–) levels were decreased in a
concentration-dependent manner
Effectiveness and safety of long-term treatment with sulfonylureas in patients with neonatal diabetes due to KCNJ11 mutations: an international cohort study
Get PDFThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThere is another ORE record for this publication: http://hdl.handle.net/10871/33435BACKGROUND: KCNJ11 mutations cause permanent neonatal diabetes through pancreatic ATP-sensitive potassium channel activation. 90% of patients successfully transfer from insulin to oral sulfonylureas with excellent initial glycaemic control; however, whether this control is maintained in the long term is unclear. Sulfonylurea failure is seen in about 44% of people with type 2 diabetes after 5 years of treatment. Therefore, we did a 10-year multicentre follow-up study of a large international cohort of patients with KCNJ11 permanent neonatal diabetes to address the key questions relating to long-term efficacy and safety of sulfonylureas in these patients. METHODS: In this multicentre, international cohort study, all patients diagnosed with KCNJ11 permanent neonatal diabetes at five laboratories in Exeter (UK), Rome (Italy), Bergen (Norway), Paris (France), and Krakow (Poland), who transferred from insulin to oral sulfonylureas before Nov 30, 2006, were eligible for inclusion. Clinicians collected clinical characteristics and annual data relating to glycaemic control, sulfonylurea dose, severe hypoglycaemia, side-effects, diabetes complications, and growth. The main outcomes of interest were sulfonylurea failure, defined as permanent reintroduction of daily insulin, and metabolic control, specifically HbA1c and sulfonylurea dose. Neurological features associated with KCNJ11 permanent neonatal diabetes were also assessed. This study is registered with ClinicalTrials.gov, number NCT02624817. FINDINGS: 90 patients were identified as being eligible for inclusion and 81 were enrolled in the study and provided long-term (>5·5 years cut-off) outcome data. Median follow-up duration for the whole cohort was 10·2 years (IQR 9·3-10·8). At most recent follow-up (between Dec 1, 2012, and Oct 4, 2016), 75 (93%) of 81 participants remained on sulfonylurea therapy alone. Excellent glycaemic control was maintained for patients for whom we had paired data on HbA1c and sulfonylurea at all time points (ie, pre-transfer [for HbA1c], year 1, and most recent follow-up; n=64)-median HbA1c was 8·1% (IQR 7·2-9·2; 65·0 mmol/mol [55·2-77·1]) before transfer to sulfonylureas, 5·9% (5·4-6·5; 41·0 mmol/mol [35·5-47·5]; p<0·0001 vs pre-transfer) at 1 year, and 6·4% (5·9-7·3; 46·4 mmol/mol [41·0-56·3]; p<0·0001 vs year 1) at most recent follow-up (median 10·3 years [IQR 9·2-10·9]). In the same patients, median sulfonylurea dose at 1 year was 0·30 mg/kg per day (0·14-0·53) and at most recent follow-up visit was 0·23 mg/kg per day (0·12-0·41; p=0·03). No reports of severe hypoglycaemia were recorded in 809 patient-years of follow-up for the whole cohort (n=81). 11 (14%) patients reported mild, transient side-effects, but did not need to stop sulfonylurea therapy. Seven (9%) patients had microvascular complications; these patients had been taking insulin longer than those without complications (median age at transfer to sulfonylureas 20·5 years [IQR 10·5-24·0] vs 4·1 years [1·3-10·2]; p=0·0005). Initial improvement was noted following transfer to sulfonylureas in 18 (47%) of 38 patients with CNS features. After long-term therapy with sulfonylureas, CNS features were seen in 52 (64%) of 81 patients. INTERPRETATION: High-dose sulfonylurea therapy is an appropriate treatment for patients with KCNJ11 permanent neonatal diabetes from diagnosis. This therapy is safe and highly effective, maintaining excellent glycaemic control for at least 10 years. FUNDING: Wellcome Trust, Diabetes UK, Royal Society, European Research Council, Norwegian Research Council, Kristian Gerhard Jebsen Foundation, Western Norway Regional Health Authority, Southern and Eastern Norway Regional Health Authority, Italian Ministry of Health, Aide aux Jeunes Diabetiques, Societe Francophone du Diabete, Ipsen, Slovak Research and Development Agency, and Research and Development Operational Programme funded by the European Regional Development Fund.We thank Exeter NIHR Clinical Research Facility, and Hélène Cavé (Genetics Department, Robert-Debré Hospital-APHP, Paris, France) and collaborators for the genetic testing of the patients in Paris. ATH and SE are supported by a Wellcome Trust Senior Investigator award (grant number 098395/Z/12/Z). PB has a Sir George Alberti Clinical Research Training Fellowship funded by Diabetes UK (16/0005407). PRN is supported by grants from the European Research Council (293574), the Norwegian Research Council (240413/F20), the Kristian Gerhard Jebsen Foundation, Helse Vest (911745), and the University of Bergen. FB is supported by the Italian Ministry of Health (project PE-2011-02350284). ÅS is supported by grants from the University of Bergen. ERP is supported by a Wellcome Trust investigator award (102820/Z/13/Z). SEF has a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (105636/Z/14/Z). The Norwegian Childhood Diabetes Registry is funded by The Southern and Eastern Norway Regional Health Authority. MP and JB were supported by grants from AJD (Aide aux Jeunes Diabétiques) and SFD (Société Francophone du Diabète). MP was supported by an educational grant from Ipsen. IK is supported by the Slovak Research and Development Agency (APVV 0107-12) and the Research and Development Operational Programme funded by the European Regional Development Fund (26240220051 and 26240220071)
Burden of injury along the development spectrum: Associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017
No full textBackground: The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods: Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results: For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions: The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum. © 2020 Author(s)
Burden of injury along the development spectrum : Associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017
No full textBackground: The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods: Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results: For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions: The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum. © 2020 Author(s).</p
