184 research outputs found

    Temporal and spatial variations of atmospheric radiocarbon in the Mexico City metropolitan area

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    This work is licensed under a Creative Commons Attribution 3.0 License.-- et al.Proceedings of the 1st International Radiocarbon in the Environment Conference 18–22 August 2014, Queen’s University Belfast, Belfast, Northern Ireland (UK).The Mexico City Metropolitan Area (MCMA) produces a complex mixture of gases and aerosols from diverse sources, including burning of fossil fuels, biomass, and wastes, with a significant biogenic contribution. We present the first results of ongoing projects to study temporal and spatial variations of 14CO2 in the area. Temporal variations reconstructed from tree rings of Taxodium mucronatum indicate a considerable radiocarbon depletion, in accordance to the vast amount of fossil fuels burnt inside Mexico Valley, with values between 62 and 246‰ lower than background values for the 1962–1968 period, and lower by 51–88‰ for the 1983–2010 period. The lower dilution found for the last decades might indicate an increase in enriched 14CO2 sources. Results from the spatial distribution, as revealed from integrated CO2 samples and grasses from six points within the MCMA collected during the 2013 dry season, show variations between sites and sample types. For integrated CO2 samples, values range from 35.6‰ to 54.0‰, and for grasses between –86.8‰ and 40.7‰. For three of the sampling points, the grasses are significantly depleted, by up to ~133‰, as compared to the corresponding integrated CO2 sample. This may result from differences in the carbon assimilation period and exposure to different CO2 sources. Higher-than-background Δ14C values were found for all integrated CO2 samples, presumably resulting from 14C-enriched CO2 derived from forest fires in the mountains during the sampling period. Results obtained so far confirm the complexity of the 14C cycle in the MCMA.This research is funded by DGAPA-UNAM through project PAPIIT-IN106113. Scholarships from CONACyT for AMJ and AMR and from Instituto de Geología and DGAPA-UNAM for AGS are gratefully acknowledged.Peer Reviewe

    Ética e qualidade em saúde: um binômio inseparável

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    By interpreting that beneficence principle is the ethical foundation and that its application is not possible without structural conditions and quality functions, this article establish the inseparable relation between ethics and quality in health care services functioning; furthermore, it develops quality determining factors for good benefits and instruments for verifying and measuring their practice and fulfillment.Interpretando que el principio del bien es el fundamento de la ética y que su giro aplicado no puede darse sin condiciones estructurales y funcionales de calidad, este artículo establece la relación indisoluble entre ética y calidad en el funcionamiento de los servicios médico sanitarios, y desarrolla además los condicionantes de calidad que hacen a su buena prestación y los instrumentos que permiten, en la práctica, medir y verificar su cumplimiento.Interpretando o princípio do bem como o fundamento da ética e que sua expressão aplicada não pode dar-se sem condições estruturais e funcionais de qualidade, este artigo estabelece a relação indissolúvel entre ética e qualidade no funcionamento dos serviços médico-sanitários e desenvolve, ademais dos condicionantes de qualidade que fazem sua boa prestação e os instrumentos que permitem, na prática, medir e verificar seu cumprimento

    Loss of Wdfy3 in mice alters cerebral cortical neurogenesis reflecting aspects of the autism pathology.

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    Autism spectrum disorders (ASDs) are complex and heterogeneous developmental disabilities affecting an ever-increasing number of children worldwide. The diverse manifestations and complex, largely genetic aetiology of ASDs pose a major challenge to the identification of unifying neuropathological features. Here we describe the neurodevelopmental defects in mice that carry deleterious alleles of the Wdfy3 gene, recently recognized as causative in ASDs. Loss of Wdfy3 leads to a regionally enlarged cerebral cortex resembling early brain overgrowth described in many children on the autism spectrum. In addition, affected mouse mutants display migration defects of cortical projection neurons, a recognized cause of epilepsy, which is significantly comorbid with autism. Our analysis of affected mouse mutants defines an important role for Wdfy3 in regulating neural progenitor divisions and neural migration in the developing brain. Furthermore, Wdfy3 is essential for cerebral expansion and functional organization while its loss-of-function results in pathological changes characteristic of ASDs

    Can a global score for anxiety and depression be obtained from the Patient Health Questionnaire (PHQ-4) in the Peruvian population that has experienced the death of a loved one? Empirical support for a unidimensional or two-dimensional model.

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    Introducción: A nivel mundial, la ansiedad y la depresión figuran como los trastornos mentales más frecuentes, tanto en entornos clínicos como en la población en general. El Patient Health Questionnaire-4 es el instrumento de acceso libre más utilizado para evaluar la ansiedad y depresión tanto en entornos clínicos como comunitarios. Objetivo: El estudio tiene como objetivo evaluar las evidencias psicométricas del Patient Health Questionnaire (PHQ-4). Método: Participaron 1015 individuos peruanos entre 18 y 69 años (M=26.4, DE=9.93, 58.6% mujeres) que experimentaron la muerte de un ser querido. Se utilizaron técnicas derivadas de la Teoría Clásica de los Test y la Teoría de Respuesta al Ítem (IRT). Resultados: Se probaron tres modelos: unidimensional (CFI = 0.989; TLI = 0.966; RMSEA = 0.075), el de dos factores (CFI = 1.000; TLI = 1.000; RMSEA = 0.000) y el modelo bifactor el cual no convergió. El modelo de dos factores fue el que más se aproximó a un modelo perfecto. La confiabilidad, evaluada mediante el coeficiente omega, fue adecuada tanto para el modelo unidimensional (? = 0.88) como para el de dos factores (?ansiedad = 0.83; ?depresión = 0.78). El análisis por IRT indicó que, los ítems del PHQ-4 son adecuados indicadores que pueden discriminar entre quienes presentan o no los rasgos de ansiedad y depresión. Respecto a la relación entre el PHQ-4 y el duelo pandémico, tanto el modelo unidimensional (como el de dos factores demostraron índices de ajuste adecuados. Se demostró que el modelo unidimensional y el de dos factores son invariantes según el género y la edad. Conclusión: A pesar de que el modelo de un factor y dos factores correlacionados muestran adecuados índices de ajuste, el segundo tuvo un mejor ajuste. Además, este modelo presentó adecuada fiabilidad, discriminación y relación significativa con el duelo disfuncional.Introduction: Worldwide, anxiety and depression are the most common mental disorders, both in clinical settings and in the general population. The Patient Health Questionnaire-4 is the most widely used open access instrument to assess anxiety and depression in both clinical and community settings. Objective: The study aims to evaluate the psychometric evidence of the Patient Health Questionnaire (PHQ-4). Method: 1015 Peruvian individuals between 18 and 69 years old (M=26.4, SD=9.93, 58.6% women) who experienced the death of a loved one participated. Techniques derived from Classical Test Theory and Item Response Theory (IRT) were used. Results: Three models were tested: one-dimensional (CFI = 0.989; TLI = 0.966; RMSEA = 0.075), the two-factor model (CFI = 1.000; TLI = 1.000; RMSEA = 0.000) and the bifactor model which did not converge. The two-factor model was the one that came closest to a perfect model. Reliability, evaluated using the omega coefficient, was adequate for both the unidimensional model (? = 0.88) and the two-factor model (? anxiety = 0.83; ? depression = 0.78). The IRT analysis indicated that the PHQ-4 items are adequate indicators that can discriminate between those who do or do not present the traits of anxiety and depression. Regarding the relationship between the PHQ-4 and pandemic grief, both the unidimensional model and the two-factor model demonstrated appropriate fit indices. It was shown that the one-dimensional and two-factor models are invariant according to gender and age. Conclusion: Although the one-factor model and two correlated factors show adequate fit indices, the second had a better fit. Furthermore, this model presented adequate reliability, discrimination and a significant relationship with dysfunctional grief

    Multi-tiered genomic analysis of head and neck cancer ties TP53 mutation to 3p loss

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    Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern patient survival. We find that TP53 mutation is frequently accompanied by loss of chromosome 3p, and that the combination of both events associates with a surprising decrease in survival rates (1.9 years versus >5 years for TP53 mutation alone). The TP53-3p interaction is specific to chromosome 3p, rather than a consequence of global genome instability, and validates in HNSCC and pan-cancer cohorts. In Human Papilloma Virus positive (HPV+) tumors, in which HPV inactivates TP53, 3p deletion is also common and associates with poor outcomes. The TP53-3p event is modified by mir-548k expression which decreases survival even further, while it is mutually exclusive with mutations to RAS signaling. Together, the identified markers underscore the molecular heterogeneity of HNSCC and enable a new multi-tiered classification of this disease

    Do salivary bypass tubes lower the incidence of pharyngocutaneous fistula following total laryngectomy? A retrospective analysis of predictive factors using multivariate analysis

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    Salivary bypass tubes (SBT) are increasingly used to prevent pharyngocutaneous fistula (PCF) following laryngectomy and pharyngolaryngectomy. There is minimal evidence as to their efficacy and literature is limited. The aim of the study was to determine if SBT prevent PCF. The study was a multicentre retrospective case control series (level of evidence 3b). Patients who underwent laryngectomy or pharyngolaryngectomy for cancer or following cancer treatment between 2011 and 2014 were included in the study. The primary outcome was development of a PCF. Other variables recorded were age, sex, prior radiotherapy or chemoradiotherapy, prior tracheostomy, type of procedure, concurrent neck dissection, use of flap reconstruction, use of prophylactic antibiotics, the suture material used for the anastomosis, tumour T stage, histological margins, day one post-operative haemoglobin and whether a salivary bypass tube was used. Univariate and multivariate analysis were performed. A total of 199 patients were included and 24 received salivary bypass tubes. Fistula rates were 8.3% in the SBT group (2/24) and 24.6% in the control group (43/175). This was not statistically significant on univariate (p value 0.115) or multivariate analysis (p value 0.076). In addition, no other co-variables were found to be significant. No group has proven a benefit of salivary bypass tubes on multivariate analysis. The study was limited by a small case group, variations in tube duration and subjects given a tube may have been identified as high risk of fistula. Further prospective studies are warranted prior to recommendation of salivary bypass tubes following laryngectomy

    The Neutron star Interior Composition Explorer (NICER): design and development

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    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Improved risk stratification of patients with atrial fibrillation: an integrated GARFIELD-AF tool for the prediction of mortality, stroke and bleed in patients with and without anticoagulation.

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    OBJECTIVES: To provide an accurate, web-based tool for stratifying patients with atrial fibrillation to facilitate decisions on the potential benefits/risks of anticoagulation, based on mortality, stroke and bleeding risks. DESIGN: The new tool was developed, using stepwise regression, for all and then applied to lower risk patients. C-statistics were compared with CHA2DS2-VASc using 30-fold cross-validation to control for overfitting. External validation was undertaken in an independent dataset, Outcome Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). PARTICIPANTS: Data from 39 898 patients enrolled in the prospective GARFIELD-AF registry provided the basis for deriving and validating an integrated risk tool to predict stroke risk, mortality and bleeding risk. RESULTS: The discriminatory value of the GARFIELD-AF risk model was superior to CHA2DS2-VASc for patients with or without anticoagulation. C-statistics (95% CI) for all-cause mortality, ischaemic stroke/systemic embolism and haemorrhagic stroke/major bleeding (treated patients) were: 0.77 (0.76 to 0.78), 0.69 (0.67 to 0.71) and 0.66 (0.62 to 0.69), respectively, for the GARFIELD-AF risk models, and 0.66 (0.64-0.67), 0.64 (0.61-0.66) and 0.64 (0.61-0.68), respectively, for CHA2DS2-VASc (or HAS-BLED for bleeding). In very low to low risk patients (CHA2DS2-VASc 0 or 1 (men) and 1 or 2 (women)), the CHA2DS2-VASc and HAS-BLED (for bleeding) scores offered weak discriminatory value for mortality, stroke/systemic embolism and major bleeding. C-statistics for the GARFIELD-AF risk tool were 0.69 (0.64 to 0.75), 0.65 (0.56 to 0.73) and 0.60 (0.47 to 0.73) for each end point, respectively, versus 0.50 (0.45 to 0.55), 0.59 (0.50 to 0.67) and 0.55 (0.53 to 0.56) for CHA2DS2-VASc (or HAS-BLED for bleeding). Upon validation in the ORBIT-AF population, C-statistics showed that the GARFIELD-AF risk tool was effective for predicting 1-year all-cause mortality using the full and simplified model for all-cause mortality: C-statistics 0.75 (0.73 to 0.77) and 0.75 (0.73 to 0.77), respectively, and for predicting for any stroke or systemic embolism over 1 year, C-statistics 0.68 (0.62 to 0.74). CONCLUSIONS: Performance of the GARFIELD-AF risk tool was superior to CHA2DS2-VASc in predicting stroke and mortality and superior to HAS-BLED for bleeding, overall and in lower risk patients. The GARFIELD-AF tool has the potential for incorporation in routine electronic systems, and for the first time, permits simultaneous evaluation of ischaemic stroke, mortality and bleeding risks. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF (NCT01090362) and for ORBIT-AF (NCT01165710)

    Two-year outcomes of patients with newly diagnosed atrial fibrillation: results from GARFIELD-AF.

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    AIMS: The relationship between outcomes and time after diagnosis for patients with non-valvular atrial fibrillation (NVAF) is poorly defined, especially beyond the first year. METHODS AND RESULTS: GARFIELD-AF is an ongoing, global observational study of adults with newly diagnosed NVAF. Two-year outcomes of 17 162 patients prospectively enrolled in GARFIELD-AF were analysed in light of baseline characteristics, risk profiles for stroke/systemic embolism (SE), and antithrombotic therapy. The mean (standard deviation) age was 69.8 (11.4) years, 43.8% were women, and the mean CHA2DS2-VASc score was 3.3 (1.6); 60.8% of patients were prescribed anticoagulant therapy with/without antiplatelet (AP) therapy, 27.4% AP monotherapy, and 11.8% no antithrombotic therapy. At 2-year follow-up, all-cause mortality, stroke/SE, and major bleeding had occurred at a rate (95% confidence interval) of 3.83 (3.62; 4.05), 1.25 (1.13; 1.38), and 0.70 (0.62; 0.81) per 100 person-years, respectively. Rates for all three major events were highest during the first 4 months. Congestive heart failure, acute coronary syndromes, sudden/unwitnessed death, malignancy, respiratory failure, and infection/sepsis accounted for 65% of all known causes of death and strokes for <10%. Anticoagulant treatment was associated with a 35% lower risk of death. CONCLUSION: The most frequent of the three major outcome measures was death, whose most common causes are not known to be significantly influenced by anticoagulation. This suggests that a more comprehensive approach to the management of NVAF may be needed to improve outcome. This could include, in addition to anticoagulation, interventions targeting modifiable, cause-specific risk factors for death. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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