120 research outputs found
A Wear Analysis Carried On Connecting Rod Bearings From Internal Combustion Engines
In the present work, an analysis was carried out to know the wear modes present in connecting rod bearings from internal combustion engines. These mechanical elements were selected since they are exposed to different engineering failures such as incorrect assembly, severe loads, extreme temperatures, inadequate conditions, and loss of lubricity. In this particular case, the bearings that were selected had a service life of approximately 8 years. Different techniques such as SEM and optical microscopy, EDS analysis, hardness testing, and surface profilometry were used to characterize the unworn and worn bearings. Wear mechanisms such as sliding wear (scoring), fatigue wear with cracks where torn out material was clearly observed, discoloration areas, and two- and three-body abrasion wear (rubbing marks) were identified on the bearing surfaces
Functional principal component analysis as a new methodology for the analysis of the impact of two rehabilitation protocols in functional recovery after stroke
[EN] Background: This study addressed the problem of evaluating the effectiveness of two protocols of physiotherapy for functional recovery after stroke. In particular, the study explored the use of Functional Principal Component Analysis (FPCA), a multivariate data analysis in order to assess and clarify the process of regaining independence after stroke. Methods: A randomized double-blind controlled trial was performed. Thirteen subjects with residual hemiparesis after a single stroke episode were measured in both in- and outpatient settings at a district hospital. All subjects were able to walk before suffering the stroke and were hemodynamically stable within the first week after stroke. Control and target groups were treated with conventional physiotherapy for stroke, but specific techniques were added for treatment of the target group depending on patients' functional levels. Independence level was assessed with the Barthel Index (BI) throughout 7 evolution stages (hemodynamic stability, beginning of standing, beginning of physical therapy sessions in the physiotherapy ward and monthly assessment for 6 months after stroke). Results: FPCA was applied for data analysis. Statistically significant differences were found in the dynamics of the recovery process between the two physiotherapy protocols. The target group showed a trend of improvement six months after stroke that was not present in the control group. Conclusions: FPCA is a method which may be used to provide greater insight into the analysis of the rehabilitation process than that provided by conventional parametric methods. So, by using the whole curves as basic data parameters, subtle differences in the rehabilitation process can be found. FPCA represents a future aid for the fine analysis of similar physiotherapy techniques, when applied in subjects with a huge variability of functional recovery, as in the case of post-stroke patients.This contribution has been carried out with financial support from the European Commission within the Seventh Framework Programme under contract FP7-ICT-2009-247935: BETTER BNCI-dr. The authors wish to thank the Stroke Rehabilitation Team of Hospital Universitari i Politecnic La Fe (Valencia, Spain), specially Dr. M.R. Beseler, physiotherapist M. Matas and physiotherapist A. Estaun. We also gratefully acknowledge patients who have participated in this study with great enthusiasm.Sánchez-Sánchez, M.; Belda Lois, JM.; Mena Del Horno, S.; Viosca Herrero, E.; Gisbert-Morant, B.; Igual-Camacho, C.; Bermejo Bosch, I. (2014). Functional principal component analysis as a new methodology for the analysis of the impact of two rehabilitation protocols in functional recovery after stroke. Journal of NeuroEngineering and Rehabilitation. 11:1-9. https://doi.org/10.1186/1743-0003-11-134S191
Cognitive clusters in first-episode psychosis
Impairments in a broad range of cognitive domains have been consistently reported in some individuals with first-episode psychosis (FEP). Cognitive deficits can be observed during the prodromal stage. However, the course of cognitive deficits is still unclear. The aim of this study was to identify cognitive subgroups over time and to compare their sociodemographic, clinical and functional profiles. A total of 114 patients with Schizophrenia Spectrum Disorders were included in the present study. We assessed subjects through psychiatric scales and eight neuropsychological tests at baseline and at two-year follow-up visit. We performed the Partition Around Medoids algorithm with all cognitive variables. Furthermore, we performed a logistic regression to identify the predictors related to the different cognitive clusters at follow-up. Two distinct subgroups were found: the first cluster characterized by cognitive impairment and a second cluster had relatively intact cognition in comparison with norms. Up to 54.7% of patients with cognitive deficits at baseline tended to improve during the first two years of treatment. Patients with intact cognition at follow-up had a higher socioeconomic status, later age of onset, lower negative symptoms and a higher cognitive reserve (CR) at baseline. CR and age of onset were the baseline variables that predicted cognitive impairment. This research allows us to obtain a better understanding of the heterogeneous profile of psychotic disorders. Identifying the characteristics of patients who will present a cognitive impairment could improve early detection and intervention. These results suggest that enhancing CR could contribute to improving the course of the illness
Cambios en la etiología, incidencia y pronóstico de la infección respiratoria aguda de vías bajas en pacientes infectados por el virus de la inmunodeficiencia humana
Aim To describe the, incidence, the changes in the etiology and the prognosis of lower respiratory tract infection (LRTI) in HIV infected patients, presenting by the first time to the Emergency Department (ED), during years 2000-2010. Study design Prospective collection of data. Metbods Data were collected on the first visit of HIV-infected patients at our ED due to a LRTI, (defined according to the criteria of the European Respiratory Society), between 1/1/2000 and 31/12/2010. A series of epidemiological and laboratory variables as well as the need for admission to the intensive care unit (ICU). LRTI etiology were also collected. The influence ofthe mentioned variables on 30-day mortality were analyzed. Results One hundred thirty one patients were included. LRTI represented 27% of visits to the ED by HIV-infected patients. Mean age was 39±9 years. 72% of patients were males. 18% required admission to the ICU. The most frequent LRTI was pneumonia by P. jiroveci in 35 cases, bacterial penumonia in 27 and pulmonary tuberculosis in 20. LRTI incidence gradually reduced significantly over time from 6.13 × 1000 patients/year in year 2000 to 0.23 × 1000 patients/year in 2010 (p<0.05). Overall mortality was 14%. Logistic regression analysis showed that admission to ICU (p<0.004) and viral load (p<0.029) were independent variables predicting mortality. Conclusion LRTI is a pathology with a decreasing incidence, probably related to the widespread utilization increased of HAART regimens. lts etiology has also been changing, but with a non negligible mortality, mostly when ICU admission was required.Objetivo
Describir la incidencia, la etiología y el pronóstico de la infección de las vías espiratorias bajas (IVRB) en los pacientes VIH, que acudieron a un Servicio de Urgencias (SU), durante el período del 2000–2010.
Diseño del estudio
Estudio prospectivo de 10 años de evolución.
Métodos
Se recogió únicamente el primer episodio del paciente que acude al SU por IRVB (definida según la European Respiratory Society). Se analizaron una serie de variables epidemiológicas y de laboratorio, así como la necesidad de ingreso en una unidad de cuidados intensivos (UCI). Se estudió la etiología de la IRVB y la incidencia. Finalmente se analizaron la influencia de las variables con la mortalidad a 30 días.
Resultados
Se incluyeron un total de 131 pacientes. La edad media fue de 39 ± 9 años. El 72% de los pacientes eran varones y el 18% de los pacientes requirieron ingreso en la UCI. La IRVB más frecuente fue la neumonía por P. jirovecci, seguida de la neumonía bacteriana en 27 y la tuberculosis pulmonar en 20. La incidencia de IRVB se ha ido reduciendo gradualmente de forma significativa, 6,13 × 1.000 pacientes/año en 2000 a 0,23 × 1.000 pacientes/año en 2010 (p < 0,05). El análisis de regresión logística mostró que la única variable que predijo mortalidad fue el ingreso en UCI (p < 0,05; OR: 73,01).
Conclusión
La IRVB es una enfermedad cuya incidencia y etiología han ido disminuyendo y cambiando respectivamente, probablemente en relación con la utilización generalizada del TAR. Sin embargo, todavía presenta una mortalidad nada despreciable, que es mayor cuando el paciente requiere ingreso en la UCI
Prevalence and genotype distribution of cervical human papilomavirus infection in the pre-vaccination era: a population-based study in the Canary Islands
Objective: National Spanish studies show that prevalence of cervical human papillomavirus (HPV) infection in the female population is increasingly frequent, with an overall estimate of 14% in women aged 18-65 years. The objective of this study is to know the prevalence and distribution of HPV types in the female population of the Canary Islands prior to the introduction of HPV vaccines and to investigate the associated clinical and sociodemographic factors. Methods: Based on the Primary Health Care database, a sample of adult women (aged 18-65 years) of Gran Canaria (GC) and Tenerife (TF) stratified into nine age groups was carried out between 2002 and 2007. Women were contacted by postal letter and telephone call and were visited in their primary care centre. A clinical-epidemiological survey was completed and cervical samples were taken for cytological study and HPV detection. HPV prevalence and its 95% CI were estimated, and multivariate analyses were performed using logistic regression to identify factors associated with the infection. Results: 6010 women participated in the study, 3847 from GC and 2163 from TF. The overall prevalence of HPV infection was 13.6% (CI 12.8%-14.5%) and 11.1% (CI 10.3%-11.9%) for high-risk types. The most frequent HPV type was 16 followed by types 51, 53, 31, 42 and 59. HPV types included in the nonavalent vaccine were detected in 54.1% of infected women. Factors associated with an increased risk of infection were: young ages (18-29 years), the number of sexual partners throughout life, not being married, being a smoker, and having had previous cervical lesions or genital warts. Conclusions: It is confirmed that prevalence of HPV infection in the female population of the Canary Islands is high, but similar to that of Spain, HPV 16 being the most frequent genotype. The determinants of infection are consistent with those of other populations
Cognitive clusters in first-episode psychosis
Impairments in a broad range of cognitive domains have been consistently reported in some individuals with first-episode psychosis (FEP). Cognitive deficits can be observed during the prodromal stage. However, the course of cognitive deficits is still unclear. The aim of this study was to identify cognitive subgroups over time and to compare their sociodemographic, clinical and functional profiles. A total of 114 patients with Schizophrenia Spectrum Disorders were included in the present study. We assessed subjects through psychiatric scales and eight neuropsychological tests at baseline and at two-year follow-up visit. We performed the Partition Around Medoids algorithm with all cognitive variables. Furthermore, we performed a logistic regression to identify the predictors related to the different cognitive clusters at follow-up. Two distinct subgroups were found: the first cluster characterized by cognitive impairment and a second cluster had relatively intact cognition in comparison with norms. Up to 54.7% of patients with cognitive deficits at baseline tended to improve during the first two years of treatment. Patients with intact cognition at follow-up had a higher socioeconomic status, later age of onset, lower negative symptoms and a higher cognitive reserve (CR) at baseline. CR and age of onset were the baseline variables that predicted cognitive impairment. This research allows us to obtain a better understanding of the heterogeneous profile of psychotic disorders. Identifying the characteristics of patients who wil
Atmospheric CO2 increasing in deep caves related to micro seismicity
Se han registrado variaciones del contenido de CO2 en la Sima de Benis (Cieza, Murcia, SE de España), a una profundidad de 280m en la Sala de las Nubes durante los primeros 6 meses de 2015. El objetivo es analizar las variaciones de CO2 con la micro-sismicidad en la zona. Para ello, se ha colocado un registrador de dióxido de carbono de tipo SENSAIR cuya frecuencia de muestreo es de 40 minutos. Se ha correlacionado los incrementos diarios en este gas con terremotos, obteniendo aumentos en 24h de hasta 300 ppm sobre un valor total cercano a 2000 ppm, en relación a terremotos localizados a menos de 15 km de la boca de la cavidad, cuya magnitud estimó el Instituto Geográfico Nacional en M3. Esta cavidad, que afecta a materiales carbonatados del Prebético Externo, se desarrolla a partir de una falla con evidencias de paleoterremotos durante el Pleistoceno Superior. Independientemente de su capacidad sismogénica, los datos muestran un aumento en la difusión y movilidad del CO2 al tránsito de ondas sísmicas.The Benis Cave is the deepest explored cave (-320m) affecting the Prebetic units of the Betic Cordillera, and
it was related to an active fault. Evidence of Upper Pleistocene paleoseismic activity and the peculiar topography of the
cave, hypogenic and fault-related halls, encouraged us to monitor the daily CO2 content in the air composition at depth
(280m), and for a time period of six months during the early 2015. Our results show a preliminary positive correlation
between micro-seismic activity in the surroundings (up to 60 km away), and the CO2 concentration (daily increasing till
300ppm for the closest microearthquakes). The maximum value of carbon dioxide recorded inside the cave was c.a.
2000 ppm, and the origin was established as pedogenic from the δ13 CO2 analysis. Therefore, we propose an increase in
the CO2 concentration into the air karst related to the micro-seismic activity. Despite this preliminary worthy results,
more data are needed to establish an accurate model for earthquake forecasting.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Economía y Competitividad (MINECO)pu
Sociodemographic, clinical and laboratory factors on admission associated with COVID19 mortality in hospitalized patients: A retrospective observational study
Background
To identify and quantify associations between baseline characteristics on hospital admission and mortality in patients with COVID-19 at a tertiary hospital in Spain.
Methods and findings
This retrospective case series included 238 patients hospitalized for COVID-19 at Hospital
Universitario Clı´nico San Cecilio (Granada, Spain) who were discharged or who died. Electronic medical records were reviewed to obtain information on sex, age, personal antecedents, clinical features, findings on physical examination, and laboratory results for each
patient. Associations between mortality and baseline characteristics were estimated as hazard ratios (HR) calculated with Cox regression models.
Series mortality was 25.6%. Among patients with dependence for basic activities of daily
living, 78.7% died, and among patients residing in retirement homes, 80.8% died. The variables most clearly associated with a greater hazard of death were age (3% HR increase per
1-year increase in age; 95%CI 1–6), diabetes mellitus (HR 2.42, 95%CI 1.43–4.09), SatO2/
FiO2 ratio (43% HR reduction per 1-point increase; 95%CI 23–57), SOFA score (19% HR
increase per 1-point increase, 95%CI 5–34) and CURB-65 score (76% HR increase per 1-
point increase, 95%CI 23–143).
Conclusions
The patients residing in retirement homes showed great vulnerability. The main baseline
factors that were independently associated with mortality in patients hospitalized for
COVID-19 were older age, diabetes mellitus, low SatO2/FiO2 ratio, and high SOFA and
CURB-65 scores.Fondos Estructurales de la Union Europea (FEDER)Unit of Excellence on Exercise and Health (UCEES), University of Granad
Evidencias de terremotos cuaternarios en una sima hipogénica: La Sima de Benís (Murcia, SE España)
La interacción entre una cueva hipogénica y la actividad de una falla cuaternaria es la principal responsable de la génesis de la cueva más profunda de la Región de Murcia y una de las mayores cavidades hipogénicas del sur de la península. La Sima de Benís presenta una amplia y única variedad de espeleotemas y de estructuras de disolución que se encuentran afectadas por deformaciones sísmicas producidas tanto por paleoterremotos durante el Pleistoceno Superior, como por terremotos instrumentales (Mw 4,8; VI EMS-98, 1999; Mula). Además, dentro de las zonas más profundas de la cueva aparecen restos fósiles “in situ” de macromamíferos (Lynx pardinus spelaeus), los cuales hemos relacionado con la actividad sísmica en el interior de la caverna. En cuanto a su topografía, esta cavidad presenta dos sectores bien diferenciados: (1) un primer sector de 150-160 m de desarrollo vertical con pozos de origen hipogénico con desarrollo de golpes de gubia y conductos de disolución ascendentes (con “outlets” y “megascallops”) y (2) un segundo sector entre los 150 - 160 m y los 320 m de profundidad, el cual se desarrolla sobre un plano de falla normal de dirección N-S (Falla de Benís). Este segundo sector de la sima es el que presenta evidencias paleosísmicas cuaternarias, dividiéndose a su vez en dos zonas en relación a la dinámica kárstica dominante: (2.a) una zona vadosa dominada por estructuras hipogénicas (donde aparecen folias y corales), junto con marcas cinemáticas de movimiento de la falla (estrías con recristalizaciones y concreciones carbonatadas) y (2.b) una zona freática profunda controlada por la precipitación de nubes de calcita bajo lámina de agua y de tamaño métrico que se desarrolla hasta los - 320 m de profundidad. En cuanto a la parte hipogénica superior de la sima, se desarrolla a favor de una fractura con relleno de calcita y de orientación E-W sobre carbonatos del Cretácico superior y el Paleoceno, con un espesor centimétrico y evidencias de relleno posterior y circulación de fluidos. La potencial actividad paleosísmica ha podido ser datada en 65 ± 17,6 ka (OIS 4) mediante el análisis de racemización de aminoácidos de los colmillos de un lince de las cavernas, el cual pudo ser afectado por un terremoto. Por último, se ha estimado el tamaño del último sismo relacionado con la actividad de la falla a partir de relaciones empíricas, con un valor de Mw oscilando entre 5,5 y 6. Para ello se ha estimado la longitud en superficie de la traza de falla que controla la cueva en profundidad y se ha comparado con el último salto cosísmico observable en el interior de la sima. Estimaciones del salto de falla acumulado y la datación del último paleoterremoto, sugieren que parte de la evolución hipogénica con paleoterremotos de esta cavidad de forma conjunta se produjo al menos, desde hace 250 ka (OIS 7)
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