La evolución del derecho a la educación en Colombia entre 1820 a 1876, como un derecho económico, social y cultural

In examining the evolution of the right to education in New Granada, Gran Colombia and the United States of Colombia, a major effort is evidenced by Francisco de Paula Santander, Mariano Ospina Rodriguez to promote the development of education as a right which should be free and compulsory.However, the project initiated by Santander Ospina Rodriguez and other presidents of the period covered from 1820 to 1876, is to prevent the social, political, cultural and civil wars that were designed to search for autonomy, freedom and independence.Al examinar la evolución del derecho a la educación en la Nueva Granada, la Gran Colombia y los Estados Unidos de Colombia, se evidencia un importante esfuerzo por parte de Francisco de Paula Santander y Mariano Ospina Rodríguez de promover el desarrollo de la educación como un derecho que debía ser gratuito y obligatorio.Sin embargo, el proyecto iniciado por Santander y Ospina Rodríguez y demás presidentes de la época comprendida entre 1820 a 1876, tiene como obstáculo los problemas sociales, políticos, culturales y las guerras civiles que tenían como fin la búsqueda de la autonomía, libertad e independencia

Long-term monitoring in primary care for chronic kidney disease and chronic heart failure: a multi-method research programme

Background: Long-term monitoring is important in chronic condition management. Despite considerable costs of monitoring, there is no or poor evidence on how, what and when to monitor. The aim of this study was to improve understanding, methods, evidence base and practice of clinical monitoring in primary care, focusing on two areas: chronic kidney disease and chronic heart failure. Objectives: The research questions were as follows: does the choice of test affect better care while being affordable to the NHS? Can the number of tests used to manage individuals with early-stage kidney disease, and hence the costs, be reduced? Is it possible to monitor heart failure using a simple blood test? Can this be done using a rapid test in a general practitioner consultation? Would changes in the management of these conditions be acceptable to patients and carers? Design: Various study designs were employed, including cohort, feasibility study, Clinical Practice Research Datalink analysis, seven systematic reviews, two qualitative studies, one cost-effectiveness analysis and one cost recommendation. Setting: This study was set in UK primary care. Data sources: Data were collected from study participants and sourced from UK general practice and hospital electronic health records, and worldwide literature. Participant: The participants were NHS patients (Clinical Practice Research Datalink: 4.5 million patients), chronic kidney disease and chronic heart failure patients managed in primary care (including 750 participants in the cohort study) and primary care health professionals. Interventions: The interventions were monitoring with blood and urine tests (for chronic kidney disease) and monitoring with blood tests and weight measurement (for chronic heart failure). Main outcome measures: The main outcomes were the frequency, accuracy, utility, acceptability, costs and cost-effectiveness of monitoring. Results: Chronic kidney disease: serum creatinine testing has increased steadily since 1997, with most results being normal (83% in 2013). Increases in tests of creatinine and proteinuria correspond to their introduction as indicators in the Quality and Outcomes Framework. The Chronic Kidney Disease Epidemiology Collaboration equation had 2.7% greater accuracy (95% confidence interval 1.6% to 3.8%) than the Modification of Diet in Renal Disease equation for estimating glomerular filtration rate. Estimated annual transition rates to the next chronic kidney disease stage are ≈ 2% for people with normal urine albumin, 3–5% for people with microalbuminuria (3–30 mg/mmol) and 3–12% for people with macroalbuminuria (> 30 mg/mmol). Variability in estimated glomerular filtration rate-creatinine leads to misclassification of chronic kidney disease stage in 12–15% of tests in primary care. Glycaemic-control and lipid-modifying drugs are associated with a 6% (95% confidence interval 2% to 10%) and 4% (95% confidence interval 0% to 8%) improvement in renal function, respectively. Neither estimated glomerular filtration rate-creatinine nor estimated glomerular filtration rate-Cystatin C have utility in predicting rate of kidney function change. Patients viewed phrases such as ‘kidney damage’ or ‘kidney failure’ as frightening, and the term ‘chronic’ was misinterpreted as serious. Diagnosis of asymptomatic conditions (chronic kidney disease) was difficult to understand, and primary care professionals often did not use ‘chronic kidney disease’ when managing patients at early stages. General practitioners relied on Clinical Commissioning Group or Quality and Outcomes Framework alerts rather than National Institute for Health and Care Excellence guidance for information. Cost-effectiveness modelling did not demonstrate a tangible benefit of monitoring kidney function to guide preventative treatments, except for individuals with an estimated glomerular filtration rate of 60–90 ml/minute/1.73 m2, aged < 70 years and without cardiovascular disease, where monitoring every 3–4 years to guide cardiovascular prevention may be cost-effective. Chronic heart failure: natriuretic peptide-guided treatment could reduce all-cause mortality by 13% and heart failure admission by 20%. Implementing natriuretic peptide-guided treatment is likely to require predefined protocols, stringent natriuretic peptide targets, relative targets and being located in a specialist heart failure setting. Remote monitoring can reduce all-cause mortality and heart failure hospitalisation, and could improve quality of life. Diagnostic accuracy of point-of-care N-terminal prohormone of B-type natriuretic peptide (sensitivity, 0.99; specificity, 0.60) was better than point-of-care B-type natriuretic peptide (sensitivity, 0.95; specificity, 0.57). Within-person variation estimates for B-type natriuretic peptide and weight were as follows: coefficient of variation, 46% and coefficient of variation, 1.2%, respectively. Point-of-care N-terminal prohormone of B-type natriuretic peptide within-person variability over 12 months was 881 pg/ml (95% confidence interval 380 to 1382 pg/ml), whereas between-person variability was 1972 pg/ml (95% confidence interval 1525 to 2791 pg/ml). For individuals, monitoring provided reassurance; future changes, such as increased testing, would be acceptable. Point-of-care testing in general practice surgeries was perceived positively, reducing waiting time and anxiety. Community heart failure nurses had greater knowledge of National Institute for Health and Care Excellence guidance than general practitioners and practice nurses. Health-care professionals believed that the cost of natriuretic peptide tests in routine monitoring would outweigh potential benefits. The review of cost-effectiveness studies suggests that natriuretic peptide-guided treatment is cost-effective in specialist settings, but with no evidence for its value in primary care settings. Limitations: No randomised controlled trial evidence was generated. The pathways to the benefit of monitoring chronic kidney disease were unclear. Conclusions: It is difficult to ascribe quantifiable benefits to monitoring chronic kidney disease, because monitoring is unlikely to change treatment, especially in chronic kidney disease stages G3 and G4. New approaches to monitoring chronic heart failure, such as point-of-care natriuretic peptide tests in general practice, show promise if high within-test variability can be overcome

Multiscale friction in lubricant-surface systems for high performance transmissions under mild wear

The lubricant-surface system is complex in nature and can significantly affect the frictional performance of high-performance transmission systems. The complexity stems from the coupled mechanical and chemical phenomena that occur at the interfacial tooth conjunctions. A combined analytical and precision experimental approach is presented to analyse the salient parameters of the lubricant-surface system. A multiscale procedure comprising topographical measurement, pin-on-disc tribometry, atomic force microscopy in lateral force mode, X-ray photo-electron spectroscopy and continuum contact mechanics analysis under mixed non-Newtonian thermo-elastohydrodynamics is used to describe the formation of a tribo-film, as well as wear and frictional characteristics of the lubricant-surface system. The contribution of chemisorbed and physisorbed bonded tribo-film on the boundary coefficient of friction is ascertained at different physical scales. Therefore, the paper presents a novel multiscale analysis, promoting improved understanding of the complex interactions between mechanisms of friction, wear and surface chemistry

High-mobility two-dimensional electron gases in Si/SiGe heterostructures on relaxed SiGe layers grown at high temperature

Low-temperature mobilities for two-dimensional electron gases (2DEGs) formed in tensile-strained Si/SiGe heterostructures are reported, with values up to 2.7 × 105 cm2 V−1 s−1 for a density of 4.6 × 1011 cm−2 electrons. The strained layers were grown at 600 ◦C in a ultra-high-vacuum chemical vapour deposition system using SiH4 and GeH4 operating at around 20 Pa. The surface morphology of the layers is also discussed and both the mobility and morphology are linked to the quality of the virtual substrates. The virtual substrate consists of strain-relaxed SiGe alloys grown on Si(001) substrates; we show that it is preferable to grow these substrates at higher temperatures and higher growth rates. For low growth rates and temperatures the 2DEG mobility as a function of sheet carrier density was found to be degraded

Impact of heterogeneity and effect size on the estimation of the optimal information size: analysis of recently published meta-analyses

Objective: To estimate the proportion of systematic reviews that meet the optimal information size (OIS) and assess the impact heterogeneity and effect size have on the OIS estimate by type of outcome (eg, mortality, semiobjective or subjective). Methods: We carried out searches of Medline and Cochrane to retrieve meta-analyses published in systematic reviews from 2010 to 2012. We estimated the OIS using Trial Sequential Analysis software (TSA V.0.9) and based on several heterogeneity and effect size scenarios, stratifying by type of outcome (mortality/ semiobjective/subjective) and by Cochrane/non-Cochrane reviews. Results: We included 137 meta-analyses out of 218 (63%) potential systematic reviews (one meta-analysis from each systematic review). Of these reviews, 83 (61%) were Cochrane and 54 (39%) non-Cochrane. The Cochrane reviews included a mean of 6.5 (SD 6.1) studies and the non-Cochrane included a mean of 13.2 (SD 10.2) studies. The mean number of patients was 2619.1 (SD 6245.8 or median 586.0) for the Cochrane and 19 888.5 (SD 32 925.7 or median 6566.5) patients for the non-Cochrane reviews. The percentage of systematic reviews that achieved the OIS for all-cause mortality outcome were 0% Cochrane and 25% for non-Cochrane reviews; for semiobjective outcome 17% for Cochrane and 46% for non-Cochrane reviews and for subjective outcome 45% for Cochrane and 72% for non-Cochrane reviews. Conclusions The number of systematic reviews that meet an optimal information size is low and varies depending on the type of outcome and the type of publication. Less than half of primary outcomes synthesised in systematic reviews achieve the OIS, and therefore the conclusions are subject to substantial uncertainty.</p

Two-dimensional electron gas mobility as a function of virtual substrate quality in strained Si/SiGe heterojunctions

The electron mobilities of two-dimensional electron gases in tensile strained Si grown on relaxed cubic SiGe alloys on Si (001) substrates are reported. The effects of using high and low temperature growth for the relaxed buffer layers, in an ultrahigh vacuum compatible chemical vapor deposition system using SiH4 and GeH4 gases, were investigated. We have measured electron mobilities of up to 2.6×105 cm2 V−1 s−1 for 4.5×1011 cm−2 carrier densities at 1.5 K; there is a strong correlation between surface morphology and underlying misfit dislocation volume densities which is reflected in the electron mobility. The highest mobility was achieved with high growth temperatures and high growth rates for the relaxed layers, while lower temperatures and growth rates produced samples with lower mobilities. We present transmission electron microscopy images, together with optical micrographs of the sample surfaces to demonstrate that substrate growth technology plays an important part in device performance and manufacturing compatibility

B-type natriuretic peptide-guided treatment for heart failure

Background Heart failure is a condition in which the heart does not pump enough blood to meet all the needs of the body. Symptoms of heart failure include breathlessness, fatigue and fluid retention. Outcomes for patients with heart failure are highly variable; however on average, these patients have a poor prognosis. Prognosis can be improved with early diagnosis and appropriate use of medical treatment, use of devices and transplantation. Patients with heart failure are high users of healthcare resources, not only due to drug and device treatments, but due to high costs of hospitalisation care. B‐type natriuretic peptide levels are already used as biomarkers for diagnosis and prognosis of heart failure, but could offer to clinicians a possible tool to guide drug treatment. This could optimise drug management in heart failure patients whilst allaying concerns over potential side effects due to drug intolerance. Objectives To assess whether treatment guided by serial BNP or NT‐proBNP (collectively referred to as NP) monitoring improves outcomes compared with treatment guided by clinical assessment alone. Search methods Searches were conducted up to 15 March 2016 in the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (OVID), Embase (OVID), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database in the Cochrane Library. Searches were also conducted in the Science Citation Index Expanded, the Conference Proceedings Citation Index on Web of Science (Thomson Reuters), World Health Organization International Clinical Trials Registry and ClinicalTrials.gov. We applied no date or language restrictions. Selection criteria We included randomised controlled trials of NP‐guided treatment of heart failure versus treatment guided by clinical assessment alone with no restriction on follow‐up. Adults treated for heart failure, in both in‐hospital and out‐of‐hospital settings, and trials reporting a clinical outcome were included. Data collection and analysis Two review authors independently selected studies for inclusion, extracted data and evaluated risk of bias. Risk ratios (RR) were calculated for dichotomous data, and pooled mean differences (MD) (with 95% confidence intervals (CI)) were calculated for continuous data. We contacted trial authors to obtain missing data. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and GRADE profiler (GRADEPRO) was used to import data from Review Manager to create a 'Summary of findings' table. Main results We included 18 randomised controlled trials with 3660 participants (range of mean age: 57 to 80 years) comparing NP‐guided treatment with clinical assessment alone. The evidence for all‐cause mortality using NP‐guided treatment showed uncertainty (RR 0.87, 95% CI 0.76 to 1.01; patients = 3169; studies = 15; low quality of the evidence), and for heart failure mortality (RR 0.84, 95% CI 0.54 to 1.30; patients = 853; studies = 6; low quality of evidence). The evidence suggested heart failure admission was reduced by NP‐guided treatment (38% versus 26%, RR 0.70, 95% CI 0.61 to 0.80; patients = 1928; studies = 10; low quality of evidence), but the evidence showed uncertainty for all‐cause admission (57% versus 53%, RR 0.93, 95% CI 0.84 to 1.03; patients = 1142; studies = 6; low quality of evidence). Six studies reported on adverse events, however the results could not be pooled (patients = 1144; low quality of evidence). Only four studies provided cost of treatment results, three of these studies reported a lower cost for NP‐guided treatment, whilst one reported a higher cost (results were not pooled; patients = 931, low quality of evidence). The evidence showed uncertainty for quality of life data (MD ‐0.03, 95% CI ‐1.18 to 1.13; patients = 1812; studies = 8; very low quality of evidence). We completed a 'Risk of bias' assessment for all studies. The impact of risk of bias from lack of blinding of outcome assessment and high attrition levels was examined by restricting analyses to only low 'Risk of bias' studies. Authors' conclusions In patients with heart failure low‐quality evidence showed a reduction in heart failure admission with NP‐guided treatment while low‐quality evidence showed uncertainty in the effect of NP‐guided treatment for all‐cause mortality, heart failure mortality, and all‐cause admission. Uncertainty in the effect was further shown by very low‐quality evidence for patient's quality of life. The evidence for adverse events and cost of treatment was low quality and we were unable to pool results.</p

B-type natriuretic peptide-guided treatment for heart failure

Background Heart failure is a condition in which the heart does not pump enough blood to meet all the needs of the body. Symptoms of heart failure include breathlessness, fatigue and fluid retention. Outcomes for patients with heart failure are highly variable; however on average, these patients have a poor prognosis. Prognosis can be improved with early diagnosis and appropriate use of medical treatment, use of devices and transplantation. Patients with heart failure are high users of healthcare resources, not only due to drug and device treatments, but due to high costs of hospitalisation care. B-type natriuretic peptide levels are already used as biomarkers for diagnosis and prognosis of heart failure, but could offer to clinicians a possible tool to guide drug treatment. This could optimise drug management in heart failure patients whilst allaying concerns over potential side effects due to drug intolerance. Objectives To assess whether treatment guided by serial BNP or NT-proBNP (collectively referred to as NP) monitoring improves outcomes compared with treatment guided by clinical assessment alone. Search methods Searches were conducted up to 15 March 2016 in the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (OVID), Embase (OVID), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database in the Cochrane Library. Searches were also conducted in the Science Citation Index Expanded, the Conference Proceedings Citation Index on Web of Science (Thomson Reuters), World Health Organization International Clinical Trials Registry and ClinicalTrials.gov. We applied no date or language restrictions. Selection criteria We included randomised controlled trials of NP-guided treatment of heart failure versus treatment guided by clinical assessment alone with no restriction on follow-up. Adults treated for heart failure, in both in-hospital and out-of-hospital settings, and trials reporting a clinical outcome were included. Data collection and analysis Two review authors independently selected studies for inclusion, extracted data and evaluated risk of bias. Risk ratios (RR) were calculated for dichotomous data, and pooled mean differences (MD) (with 95% confidence intervals (CI)) were calculated for continuous data. We contacted trial authors to obtain missing data. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and GRADE profiler (GRADEPRO) was used to import data from Review Manager to create a ’Summary of findings’ table. Main results We included 18 randomised controlled trials with 3660 participants (range of mean age: 57 to 80 years) comparing NP-guided treatment with clinical assessment alone. The evidence for all-cause mortality using NP-guided treatment showed uncertainty (RR 0.87, 95% CI 0.76 to 1.01; patients = 3169; studies = 15; low quality of the evidence), and for heart failure mortality (RR 0.84, 95% CI 0.54 to 1.30; patients = 853; studies = 6; low quality of evidence). The evidence suggested heart failure admission was reduced by NP-guided treatment (38% versus 26%, RR 0.70, 95% CI 0.61 to 0.80; patients = 1928; studies = 10; low quality of evidence), but the evidence showed uncertainty for all-cause admission (57% versus 53%, RR 0.93, 95% CI 0.84 to 1.03; patients = 1142; studies = 6; low quality of evidence). Six studies reported on adverse events, however the results could not be pooled (patients = 1144; low quality of evidence). Only four studies provided cost of treatment results, three of these studies reported a lower cost for NP-guided treatment, whilst one reported a higher cost (results were not pooled; patients = 931, low quality of evidence). The evidence showed uncertainty for quality of life data (MD -0.03, 95% CI -1.18 to 1.13; patients = 1812; studies = 8; very low quality of evidence). We completed a ’Risk of bias’ assessment for all studies. The impact of risk of bias from lack of blinding of outcome assessment and high attrition levels was examined by restricting analyses to only low ’Risk of bias’ studies. Authors’ conclusions In patients with heart failure low-quality evidence showed a reduction in heart failure admission with NP-guided treatment while lowquality evidence showed uncertainty in the effect of NP-guided treatment for all-cause mortality, heart failure mortality, and all-cause admission. Uncertainty in the effect was further shown by very low-quality evidence for patient’s quality of life. The evidence for adverse events and cost of treatment was low quality and we were unable to pool results