877 resultados para PURELY CONTINUOUS-SPECTRUM


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: Respiratory assistance with nasal continuous positive airway pressure (n-CPAP) is an effective treatment in premature newborns presenting respiratory distress. The aim of the study was to depict cardiac function, systemic (Qs) and pulmonary output (Qp) by echocardiography in stable premature infants requiring prolonged n-CPAP. Our hypothesis was that n-CPAP could reduce pulmonary blood flow. Patients and methods: All premature infants < 32 weeks gestation, > 7 days-old, requiring n-CPAP without severe respiratory compromise nor need for additional oxygen were prospectively included. Every patient had a first echocardiography while on n-CPAP. N-CPAP was then discontinued for two hours and a second echocardiography was performed. Results: 17 premature infants were included. Mean gestational age was 28 ± 2 weeks and mean weight 1.1 ± 0.3 kg. Following retrieval of n-CPAP we observed an increase in Qp of 53 ml/kg/min (95% CI 19-87 ml/kg/min), but no significant change in Qs. Consecutively a significant increase in Qp/Qs ratio of 16% was found (95% CI 7-29%). Conclusions: Nasal continuous positive airway pressure has hemodynamic effects in preterm infants in stable pulmonary and cardiac conditions. It reduces pulmonary output without interference with systemic output.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[eng] The group of teaching innovation in the area of Botany (GIBAF), University of Barcelona (UB), is raised each year to design new accreditation activities under continuous evaluation framework. We present the experience carried out during the academic year 2008-09 in the course of Pharmaceutical Botany. The aim has been to involve students for a semester in the authorship of a tutored project immediately useful and of easy permanence, beyond its assessment proving usefulness. The Medicinal Plants Garden of the Monastery of Pedralbes has been used as a resource and a collaboration agreement has been signed between the UB faculty and the Institute of Culture of Barcelona. The students have developed the work using the Moodle platform CampusvirtualUB into five stages which included preparation of files by students that have been modified in some steps following the various feedbacks from teachers. At the beginning of the activity, students were provided with a complete schedule of activities, the schedule for its implementation, and a total of 18 forced-use library resources. Finally, through Google sites, a website has been implemented, allowing for a virtual tour of the garden, documenting by referenced literature 50 medicinal plants for their nomenclature, botanical description, distribution, uses historical, current and future) and toxicity. The result of the activity was presented at a public ceremony in the Monastery of Pedralbes and is available at: http://sites.google.com/site/jardimedievalpedralbes/ [spa] El grupo de innovación docente integrado por profesores del área de Botánica (GIBAF) de la Universidad de Barcelona (UB) se plantea cada curso el diseño de nuevas actividades acreditativas en el marco de la evaluación continuada. Se presenta la experiencia llevada a cabo durante el curso 2008-09 en la asignatura Botánica Farmacéutica. El objetivo ha sido implicar durante un semestre a los estudiantes en la autoría de un proyecto tutorizado de inmediata utilidad y clara perdurabilidad, más allá de su utilidad acreditativa. Como recurso se ha utilizado el Jardín de Plantas Medicinales del Monasterio de Pedralbes y se ha firmado un convenio de colaboración docente entre la UB y el Instituto de Cultura de Barcelona. Los estudiantes han realizado el trabajo utilizando la plataforma Moodle del Campus virtual de la UB en cinco etapas que han incluido la confección de unas fichas que se han ido modificando en función de las diversas retroacciones de los profesores. Al inicio de la actividad, se facilitó a los estudiantes el cronograma completo de la actividad, la pauta para su realización, así como un total de 18 recursos bibliográficos de uso obligado. Finalmente, a través de GoogleSites, se ha realizado una web que permite realizar un paseo virtual por el jardín, documentando de forma referenciada para las 50 plantas medicinales su nomenclatura, descripción botánica, distribución, usos (históricos, actuales y futuros) y toxicidad. El resultado de la actividad fue presentado en un acto público en el Monasterio de Pedralbes y puede consultarse en: http://sites.google.com/site/jardimedievalpedralbes/

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Heart transplantation (HTx) is the treatment of choice for end-stage heart failure but the limited availability of heart's donors still represents a major issue. So long-term mechanical circulatory support (MCS) has been proposed as an alternative treatment option to assist patients scheduled on HTx waiting list bridging them for a variable time period to cardiac transplantation-the so-called bridge-to-transplantation (BTT) strategy. Nowadays approximately 90% of patients being considered for MCS receive a left ventricular assist device (LVAD). In fact, LVAD experienced several improvements in the last decade and the predominance of continuous-flow over pulsatile-flow technology has been evident since 2008. The aim of the present report is to give an overview of continuous-flow LVAD utilization in the specific setting of the BTT strategy taking into consideration the most representative articles of the scientific literature and focusing the attention on the evolution, clinical outcomes, relevant implications on the HTx strategy and future perspectives of the continuous-flow LVAD technology.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We report the largest international study on Glanzmann thrombasthenia (GT), an inherited bleeding disorder where defects of the ITGA2B and ITGB3 genes cause quantitative or qualitative defects of the αIIbβ3 integrin, a key mediator of platelet aggregation. Sequencing of the coding regions and splice sites of both genes in members of 76 affected families identified 78 genetic variants (55 novel) suspected to cause GT. Four large deletions or duplications were found by quantitative real-time PCR. Families with mutations in either gene were indistinguishable in terms of bleeding severity that varied even among siblings. Families were grouped into type I and the rarer type II or variant forms with residual αIIbβ3 expression. Variant forms helped identify genes encoding proteins mediating integrin activation. Splicing defects and stop codons were common for both ITGA2B and ITGB3 and essentially led to a reduced or absent αIIbβ3 expression; included was a heterozygous c.1440-13_c.1440-1del in intron 14 of ITGA2B causing exon skipping in seven unrelated families. Molecular modeling revealed how many missense mutations induced subtle changes in αIIb and β3 domain structure across both subunits, thereby interfering with integrin maturation and/or function. Our study extends knowledge of GT and the pathophysiology of an integrin.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The concept of conditional stability constant is extended to the competitive binding of small molecules to heterogeneous surfaces or macromolecules via the introduction of the conditional affinity spectrum (CAS). The CAS describes the distribution of effective binding energies experienced by one complexing agent at a fixed concentration of the rest. We show that, when the multicomponent system can be described in terms of an underlying affinity spectrum [integral equation (IE) approach], the system can always be characterized by means of a CAS. The thermodynamic properties of the CAS and its dependence on the concentration of the rest of components are discussed. In the context of metal/proton competition, analytical expressions for the mean (conditional average affinity) and the variance (conditional heterogeneity) of the CAS as functions of pH are reported and their physical interpretation discussed. Furthermore, we show that the dependence of the CAS variance on pH allows for the analytical determination of the correlation coefficient between the binding energies of the metal and the proton. Nonideal competitive adsorption isotherm and Frumkin isotherms are used to illustrate the results of this work. Finally, the possibility of using CAS when the IE approach does not apply (for instance, when multidentate binding is present) is explored. © 2006 American Institute of Physics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The few studies that have evaluated syntax in autism spectrum disorder (ASD) have yielded conflicting findings: some suggest that once matched on mental age, ASD and typically developing controls do not differ for grammar, while others report that morphosyntactic deficits are independent of cognitive skills in ASD. There is a need for a better understanding of syntax in ASD and its relation to, or dissociation from, nonverbal abilities. AIMS: Syntax in ASD was assessed by evaluating subject and object relative clause comprehension in adolescents and adults diagnosed with ASD with a performance IQ within the normal range, and with or without a history of language delay. METHODS & PROCEDURES: Twenty-eight participants with ASD (mean age 21.8) and 28 age-matched controls (mean age 22.07) were required to point to a character designated by relative clauses that varied in syntactic complexity. OUTCOMES & RESULTS: Scores indicate that participants with ASD regardless of the language development history perform significantly worse than age-matched controls with object relative clauses. In addition, participants with ASD with a history of language delay (diagnosed with high-functioning autism in the DSM-IV-TR) perform worse on subject relatives than ASD participants without language delay (diagnosed with Asperger syndrome in the DSM-IV-TR), suggesting that these two groups do not have equivalent linguistic abilities. Performance IQ has a positive impact on the success of the task for the population with ASD. CONCLUSIONS & IMPLICATIONS: This study reveals subtle grammatical difficulties remaining in adult individuals with ASD within normal IQ range as compared with age-matched peers. Even in the absence of a history of language delay in childhood, the results suggest that a slight deficit may nevertheless be present and go undetected by standardized language assessments. Both groups with and without language delay have a similar global performance on relative clause comprehension; however, the study also indicates that the participants with reported language delay show more difficulty with subject relatives than the participants without language delay, suggesting the presence of differences in linguistic abilities between these subgroups of ASD.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[cas] Si bien los conceptos de «clasificación» y «tipología» han estado vinculados a la Arqueología desde las primeras seriaciones de materiales puramente descriptivas de los primeros anticuarios y diletantes de los siglos XVII-XVIII, no es menos cierto que su desarrollo ulterior durante los siglos XIX y XX madurado al abrigo del marco cientificista del positivismo decimonónico se ha visto estimulado fundamentalmente por dos factores necesarios. En primer lugar, por el permanente debate librado por las diferentes corrientes teórico-metodológicas que incansablemente han ido sacudiendo uno tras otro, en un imparable proceso dialéctico, los sucesivos paradigmas preexistentes. Y en segundo lugar, por el progreso de la tecnología informática, que permitió el procesamiento más rápido y objetivo del cada vez más numeroso y abrumador conjunto de datos generado por la investigación.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Let $S_*$ and $S_*^\{infty}$ be the functors of continuous and differentiable singular chains on the category of differentiable manifolds. We prove that the natural transformation $i: S_*^\infty \rightarrow S_*$, which induces homology equivalences over each manifold, is not a natural homotopy equivalence.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Teräksenvalmistajilta edellytetään jatkuvasti panostusta laadun ja laadunvarmistuksen kehittämiseen. Teräksen laatu ja puhtaus korostuvat varsinkin silloin, kun terästä käytetään vaativiin käyttökohteisiin, kuten autoteollisuuden tarpeisiin. Ultraäänitarkastusmenetelmää käytetään laadun-varmistuksessa teräksen sisävikojen etsimiseen. Ultraäänitarkastuksessa lähetetään suuritaajuuksista ääntä kappaleeseen. Ääni etenee materiaalissa ja heijastuu erilaisista epäjatkuvuuskohdista. Luotaimeen palaavaa ääntä analysoimalla saadaan tietoa teräksestä ja sen sisävioista. Ultraäänitarkastuksen ongelmana on vian tyypin määrittäminen hankaluus sekä herkkyys tutkittavan materiaalin aineominaisuuksille. Työn tavoitteena oli immersioultraäänitarkastuksen kehittäminen sovellettuna teräksenvalmistajan tarpeisiin. Materiaalin aineominaisuuksista tutkittiin seostuksen vaikutusta. Teräslajit tarkastettiin valssitilaisena, karkaistuna ja normalisoituna. Lisäksi tutkittiin kappaleen pinnankarheuden ja -muodon vaikutusta tarkastukseen. Vikatyyppien tunnistamisen mahdollisuuksia ultra-äänitarkastuksessa selvitettiin käyttäen FFT- taajuusanalyysiä. Erilailla lämpökäsitellyillä teräslajeilla näytti eniten tuloksiin vaikuttavan terästen raekoko. Valssitilaisilla teräksillä raekoko on suuri, jolloin ultraääni vaimenee voimakkaasti teräksessä. Huomattavaa kuitenkin oli, että mikäli lämpö-käsittelyillä ei teräksen raekokoa saada juuri pienennettyä, ei myöskään vaimeneminen vähene. Tämän vuoksi lämpökäsittely ei välttämättä ole aina tarpeellinen valmisteltaessa ultraääninäytteitä. Fourier’n taajuusanalyysissä huomattiin olevan eroavaisuuksia verrattaessa huokosista ja sulkeumista palaavien kaikujen taajuusspektrejä. Näiden tulosten perusteella näyttäisi olevan mahdollista käyttää FFT- menetelmää ultraääni-tarkastuksessa vikojen luokitteluun.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Digoxin intoxication results in predominantly digestive, cardiac and neurological symptoms. This case is outstanding in that the intoxication occurred in a nonagenarian and induced severe, extensively documented visual symptoms as well as dysphagia and proprioceptive illusions. Moreover, it went undiagnosed for a whole month despite close medical follow-up, illustrating the difficulty in recognizing drug-induced effects in a polymorbid patient. CASE PRESENTATION: Digoxin 0.25 mg qd for atrial fibrillation was prescribed to a 91-year-old woman with an estimated creatinine clearance of 18 ml/min. Over the following 2-3 weeks she developed nausea, vomiting and dysphagia, snowy and blurry vision, photopsia, dyschromatopsia, aggravated pre-existing formed visual hallucinations and proprioceptive illusions. She saw her family doctor twice and visited the eye clinic once until, 1 month after starting digoxin, she was admitted to the emergency room. Intoxication was confirmed by a serum digoxin level of 5.7 ng/ml (reference range 0.8-2 ng/ml). After stopping digoxin, general symptoms resolved in a few days, but visual complaints persisted. Examination by the ophthalmologist revealed decreased visual acuity in both eyes, 4/10 in the right eye (OD) and 5/10 in the left eye (OS), decreased color vision as demonstrated by a score of 1/13 in both eyes (OU) on Ishihara pseudoisochromatic plates, OS cataract, and dry age-related macular degeneration (ARMD). Computerized static perimetry showed non-specific diffuse alterations suggestive of either bilateral retinopathy or optic neuropathy. Full-field electroretinography (ERG) disclosed moderate diffuse rod and cone dysfunction and multifocal ERG revealed central loss of function OU. Visual symptoms progressively improved over the next 2 months, but multifocal ERG did not. The patient was finally discharged home after a 5 week hospital stay. CONCLUSION: This case is a reminder of a complication of digoxin treatment to be considered by any treating physician. If digoxin is prescribed in a vulnerable patient, close monitoring is mandatory. In general, when facing a new health problem in a polymorbid patient, it is crucial to elicit a complete history, with all recent drug changes and detailed complaints, and to include a drug adverse reaction in the differential diagnosis.