Energy impact of the air infiltration in residential buildings in the Mediterranean area of Spain and the Canary islands

Air infiltration through the building envelope has already been proven to have a significant energy impact in dwellings. Different studies have been carried out in Europe, but there is still a lack of knowledge in this field regarding mild climates. An experimental field study has been carried out in the Mediterranean climate area of Spain and the Canary Islands in order to assess the air permeability of the building envelope and its energy impact. A wide characterization and Blower Door tests have been performed in 225 cases in Alicante, Barcelona, Málaga, Sevilla and Las Palmas de Gran Canaria for this purpose. The obtained mean air permeability rate for the 225 studied cases was 6.56 m3/(h·m2). The influence of several variables on airtightness was statistically analysed, although only location, climate zone and window material were found to be significant. Air infiltration has an energy impact between 2.43 and 16.44 kWh/m2·year on the heating demand and between 0.54 and 3.06 kWh/m2·year on the cooling demand.This work was supported by the Spanish Ministry of Economy and Competitiveness (BIA2015-64321-R) under the research project INFILES: Repercusión energética de la permeabilidad al aire de los edificios residenciales en España: estudio y caracterización de sus infiltraciones

Methodology for the Study of the Envelope Airtightness of Residential Buildings in Spain: A Case Study

Air leakage and its impact on the energy performance of dwellings has been broadly studied in countries with cold climates in Europe, US, and Canada. However, there is a lack of knowledge in this field in Mediterranean countries. Current Spanish building regulations establish ventilation rates based on ideal airtight envelopes, causing problems of over-ventilation and substantial energy losses. The aim of this paper is to develop a methodology that allows the characterization of the envelope of the housing stock in Spain in order to adjust ventilation rates taking into consideration air leakage. A methodology that is easily applicable to other countries that consider studying the airtightness of the envelope and its energetic behaviour improvement is proposed. A statistical sampling method has been established to determine the dwellings to be tested, considering relevant variables concerning airtightness: climate zone, year of construction, and typology. The air leakage rate is determined using a standardized building pressurization technique according to European Standard EN 13829. A representative case study has been presented as an example of the implementation of the designed methodology and results are compared to preliminary values obtained from the database

Central Venous Reflux, a Rare Cause of Neurological Manifestations in Hemodialysis Patients: A Case Report and Literature Review

Central venous disease (CVD) is a serious complication in hemodialysis patients. Neurological manifestations are rare. We describe a female with end-stage renal disease with throbbing headache accompanied by paresthesia, weakness, and abnormal posture of her right hand during dialysis sessions. Motor symptoms completely resolved after each dialysis session, although the headaches persisted for several hours. No neurological deficit was evidenced on physical examination. Digital subtraction angiography identified an incomplete thrombosis of the left brachiocephalic vein with retrograde flow in the internal jugular vein, sigmoid sinus, and transverse sinus on the left side. This case illustrates that cerebral venous congestion due to CVD can produce neurological symptoms. Furthermore, we systematically review the literature to identify the characteristics of the cases described so far. This allows clinicians to know the entity and have a high index of suspicion in a hemodialysis patient who develops neurological symptoms

Prevalence of Fabry Disease in Young Patients with Stroke in Argentina

Background Fabry disease (FD) is an underdiagnosed cause of stroke in young adults, but the frequency of this association is largely unknown. We estimated the prevalence of FD in a nationwide cohort of young adults who had stroke and transient ischemic attack (TIA) in Argentina. Methods This was a prospective, multicenter study of stroke and FD in young adults (18-55 years) conducted in Argentina between 2011 and 2015. Patients were enrolled if they had had a TIA or an ischemic or hemorrhagic stroke within the previous 180 days. FD was diagnosed by measuring α-galactosidase A activity (males) and through genetic studies (females). Results We enrolled 311 patients (54% men, mean age: 41 years). Ischemic events occurred in 89% of patients (80% infarcts, 9% TIA) and hemorrhagic strokes in 11%. One female (.3% of the total group, 1% of the cryptogenic ischemic strokes) had the pathogenic mutation c.888G>A/p.Met296Ile /Exon 6 on the GAL gene. Her only other manifestation of FD was angiokeratoma. Eighteen females had nonpathogenic intronic variations: c.-10C>T, c.-12G>A, or both. Two patients had the nonpathogenic mutation D313Y, while a third had the likely benign mutation S126G. Conclusions FD was identified in 1 patient (.3%) in this first Latin American study. The patient presented with a late-onset oligo-symptomatic form of the disease. A large number of nonpathogenic mutations were present in our cohort, and it is essential that they not be mistaken for pathogenic mutations to avoid unnecessary enzyme replacement treatment.Instituto de Estudios Inmunológicos y Fisiopatológico

Lepra:: ¿una enfermedad del pasado?

La lepra es una infección humana muy extendida, endémica en lugares en los que el ser humano convive en situación de hacinamiento, escasa higiene y, con frecuencia, mala nutrición. La enfermedad afecta de forma predominante y característica la piel y el sistema nervioso. Las manifestaciones cutáneas son heterogéneas y la agresión neurológica se circunscribe a neuropatías sensitivas, bien difusas, de predominio distal, bien segmentarias y asimétricas conocidas como multineuritis o mononeuritis múltiple

Convexity subarachnoid hemorrhage: clinical features and etiology of an Argentinian cohort

ABSTRACT Nontraumatic convexity subarachnoid hemorrhage is an increasingly recognized subtype of subarachnoid bleeding. Objective: Our aim was to describe the etiology and clinical features of a cohort of patients with convexity subarachnoid hemorrhage. Methods: We retrospectively analyzed all cases of convexity subarachnoid hemorrhage admitted to our hospital between January 2012 and April 2017. Demographic features, clinical characteristics, complementary investigations, etiology and mortality were assessed. Twenty patients (65% females) were identified. Mean age: 53 years (range, 15-86 years). Results: Symptoms on admission: headache (65%), sensory and/or motor symptoms (50%) and seizures (35%). Commonest causes: cerebral vein thrombosis (20%), reversible cerebral vasoconstriction syndrome (20%) and cerebral amyloid angiopathy (20%). Two patients died. Conclusion: Convexity subarachnoid hemorrhage may be related to a wide spectrum of etiologies. In our patients, an increased prevalence of cerebral vein thrombosis was observed. Mortality was low and not related to the bleeding itself