Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 106
Filtrar
2.
Phys Rev Lett ; 132(9): 091901, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38489625

RESUMEN

We perform the first global quantum chromodynamics (QCD) analysis of dihadron production for a comprehensive set of data in electron-positron annihilation, semi-inclusive deep-inelastic scattering, and proton-proton collisions, from which we extract simultaneously the transversity distributions of the nucleon and π^{+}π^{-} dihadron fragmentation functions. We incorporate in our fits known theoretical constraints on transversity, namely, its small-x asymptotic behavior and the Soffer bound. We furthermore show that lattice-QCD results for the tensor charges can be successfully included in the analysis. This resolves the previously reported incompatibility between the tensor charges extracted from dihadron production data and lattice QCD. We also find agreement with results for the transversity and tensor charges obtained from measurements on single-hadron production. Overall, our work demonstrates for the first time the universal nature of all available information for the transversity distributions and the tensor charges of the nucleon.

3.
Eur J Paediatr Neurol ; 47: 118-130, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38284996

RESUMEN

BACKGROUND: Acute cerebellitis (AC) in children and adolescents is an inflammatory disease of the cerebellum due to viral or bacterial infections but also autoimmune-mediated processes. OBJECTIVE: To investigate the frequency of autoantibodies in serum and CSF as well as the neuroradiological features in children with AC. MATERIAL AND METHODS: Children presenting with symptoms suggestive of AC defined as acute/subacute onset of cerebellar symptoms and MRI evidence of cerebellar inflammation or additional CSF pleocytosis, positive oligoclonal bands (OCBs), and/or presence of autoantibodies in case of negative cerebellar MRI. Children fulfilling the above-mentioned criteria and a complete data set including clinical presentation, CSF studies, testing for neuronal/cerebellar and MOG antibodies as well as MRI scans performed at disease onset were eligible for this retrospective multicenter study. RESULTS: 36 patients fulfilled the inclusion criteria for AC (f:m = 14:22, median age 5.5 years). Ataxia was the most common cerebellar symptom present in 30/36 (83 %) in addition to dysmetria (15/36) or dysarthria (13/36). A substantial number of children (21/36) also had signs of encephalitis such as somnolence or seizures. In 10/36 (28 %) children the following autoantibodies (abs) were found: MOG-abs (n = 5) in serum, GFAPα-abs (n = 1) in CSF, GlyR-abs (n = 1) in CSF, mGluR1-abs (n = 1) in CSF and serum. In two further children, antibodies were detected only in serum (GlyR-abs, n = 1; GFAPα-abs, n = 1). MRI signal alterations in cerebellum were found in 30/36 children (83 %). Additional supra- and/or infratentorial lesions were present in 12/36 children, including all five children with MOG-abs. Outcome after a median follow-up of 3 months (range: 1 a 75) was favorable with an mRS ≤2 in 24/36 (67 %) after therapy. Antibody (ab)-positive children were significantly more likely to have a better outcome than ab-negative children (p = .022). CONCLUSION: In nearly 30 % of children in our study with AC, a range of abs was found, underscoring that autoantibody testing in serum and CSF should be included in the work-up of a child with suspected AC. The detection of MOG-abs in AC does expand the MOGAD spectrum.


Asunto(s)
Autoanticuerpos , Encefalitis , Adolescente , Niño , Preescolar , Humanos , Ataxia , Cerebelo/diagnóstico por imagen , Encefalitis/diagnóstico por imagen , Inflamación , Estudios Retrospectivos
4.
AJNR Am J Neuroradiol ; 42(4): 782-786, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33707281

RESUMEN

BACKGROUND AND PURPOSE: Although "corpus callosum agenesis" is an umbrella term for multiple entities, prenatal counseling is based reductively on the presence (associated) or absence (isolated) of additional abnormalities. Our aim was to test the applicability of a fetal MR neuroimaging score in a cohort of fetuses with prenatally diagnosed isolated corpus callosum agenesis and associated corpus callosum agenesis and correlate it with neurodevelopmental outcomes. MATERIALS AND METHODS: We performed a single-center retrospective analysis of a cohort of cases of consecutive corpus callosum agenesis collected between January 2011 and July 2019. Cases were scored by 2 raters, and interater agreement was calculated. Outcome was assessed by standardized testing (Bayley Scales of Infant and Toddler Development, Kaufman Assessment Battery for Children) or a structured telephone interview and correlated with scores using 2-way ANOVA. RESULTS: We included 137 cases (74 cases of isolated corpus callosum agenesis), imaged at a mean of 27 gestational weeks. Interrater agreement was excellent (0.98). Scores were higher in associated corpus callosum agenesis (P < .0001) without a significant score difference between complete and partial corpus callosum agenesis (P = .38). Outcome was assessed in 42 children with isolated corpus callosum agenesis and 9 with associated corpus callosum agenesis (mean age, 3.1 years). MR imaging scores correctly predicted developmental outcome in 90.7% of patients with isolated corpus callosum agenesis, improving neurodevelopmental risk stratification in corpus callosum agenesis. CONCLUSIONS: The scoring system is very reproducible and can differentiate isolated corpus callosum agenesis and associated isolated corpus callosum agenesis (significantly higher scores) but not between partial and complete corpus callosum agenesis. Scores correlated with outcome in isolated corpus callosum agenesis, but there were too few associated postnatal cases of isolated corpus callosum agenesis to draw conclusions in this group.


Asunto(s)
Agenesia del Cuerpo Calloso , Agenesia del Cuerpo Calloso/diagnóstico por imagen , Cuerpo Calloso/diagnóstico por imagen , Femenino , Feto , Humanos , Imagen por Resonancia Magnética , Embarazo , Estudios Retrospectivos , Ultrasonografía Prenatal
5.
Ultrasound Obstet Gynecol ; 58(1): 34-41, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-32484578

RESUMEN

OBJECTIVES: Corpus callosal agenesis (CCA) is one of the most common brain malformations and is generally associated with a good outcome when isolated. However, up to 25% of patients are at risk of neurodevelopmental delay, which currently available clinical and imaging parameters are inadequate to predict. The objectives of this study were to apply and validate a fetal magnetic resonance imaging (MRI) anatomical scoring system in a cohort of fetuses with isolated CCA and to evaluate the correlation with postnatal neurodevelopmental outcome. METHODS: This was a retrospective cohort study of cases of prenatally diagnosed isolated CCA (as determined on ultrasound and MRI), with normal karyotype and with known postnatal neurodevelopmental outcome assessed by standardized testing. A fetal brain MRI anatomical scoring system based on seven categories (gyration, opercularization, temporal lobe symmetry, lamination, hippocampal position, basal ganglia and ventricular size) was developed and applied to the cohort; a total score of 0-11 points could be given, with a score of 0 representing normal anatomy. Images were scored independently by two neuroradiologists blinded to the outcome. For the purpose of assessing the correlation between fetal MRI score and neurodevelopmental outcome, neurodevelopmental test results were scored as follows: 0, 'below average' (poor outcome); 1, 'average'; and 2, 'above average' (good outcome). Spearman's rank coefficient was used to assess correlation, and inter-rater agreement in the assessment of fetal MRI score was calculated. RESULTS: Twenty-one children (nine females (42.9%)) fulfilled the inclusion criteria. Thirty-seven fetal MRI examinations were evaluated. Mean gestational age was 28.3 ± 4.7 weeks (range, 20-38 weeks). All fetuses were delivered after 35 weeks' gestation with no perinatal complications. Fetal MRI scores ranged from 0 to 6 points, with a median of 3 points. Inter-rater agreement in fetal MRI score assessment was excellent (intraclass correlation coefficient, 0.959 (95% CI, 0.921-0.979)). Neurodevelopmental evaluation was performed on average at 2.6 ± 1.46 years (range, 0.5-5.8 years). There was a significant negative correlation between fetal MRI score and neurodevelopmental outcome score in the three areas tested: cognitive (ρ = -0.559, P < 0.0001); motor (ρ = -0.414, P = 0.012) and language (ρ = -0.565, P < 0.0001) skills. Using fetal MRI score cut-offs of ≤ 3 (good outcome) and ≥ 4 points (high risk for poor outcome), the correct prognosis could be determined in 20/21 (95.2% (95% CI, 77.3-99.2%)) cases. CONCLUSION: By assessing structural features of the fetal brain on MRI, it may be possible to better stratify prenatally the risk of poor neurodevelopmental outcome in CCA patients. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Agenesia del Cuerpo Calloso/diagnóstico por imagen , Feto/diagnóstico por imagen , Imagen por Resonancia Magnética/estadística & datos numéricos , Trastornos del Neurodesarrollo/diagnóstico por imagen , Agenesia del Cuerpo Calloso/complicaciones , Agenesia del Cuerpo Calloso/embriología , Encéfalo/diagnóstico por imagen , Encéfalo/embriología , Preescolar , Cuerpo Calloso/diagnóstico por imagen , Cuerpo Calloso/embriología , Cuerpo Calloso/fisiopatología , Femenino , Feto/embriología , Edad Gestacional , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética/métodos , Masculino , Trastornos del Neurodesarrollo/etiología , Valor Predictivo de las Pruebas , Embarazo , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medición de Riesgo , Estadísticas no Paramétricas , Ultrasonografía Prenatal
6.
Phys Rev Lett ; 124(25): 252501, 2020 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-32639790

RESUMEN

Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at sqrt[s]=510 GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction x_{F} and transverse momentum p_{T} have been observed at low transverse momentum p_{T}<1 GeV/c for the first time, at this collision energy. The asymmetries show an approximate x_{F} scaling in the p_{T} region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.

7.
Landsc Ecol ; 35(2): 483-499, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32165789

RESUMEN

CONTEXT: The contribution of forest understory to the temperate forest carbon sink is not well known, increasing the uncertainty in C cycling feedbacks on global climate as estimated by Earth System Models. OBJECTIVES: We aimed at quantifying the effect of woody and non-woody understory vegetation on net ecosystem production (NEP) for a forested area of 158 km2 in the European Alps. METHODS: We simulated C dynamics for the period 2000-2014, characterized by above-average temperatures, windstorms and a subsequent bark beetle outbreak for the area, using the regional ecosystem model LandscapeDNDC. RESULTS: In the entire study area, woody and non-woody understory vegetation caused between 16 and 37% higher regional NEP as compared to a bare soil scenario over the 15-year period. The mean annual contribution of the understory to NEP was in the same order of magnitude as the average annual European (EU-25) forest C sink. After wind and bark beetle disturbances, the understory effect was more pronounced, leading to an increase in NEP between 35 and 67% compared to simulations not taking into account these components. CONCLUSIONS: Our findings strongly support the importance of processes related to the understory in the context of the climate change mitigation potential of temperate forest ecosystems. The expected increases in stand replacing disturbances due to climate change call for a better representation of understory vegetation dynamics and its effect on the ecosystem C balance in regional assessments and Earth System Models.

8.
Curr For Rep ; 6: 61-80, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35747899

RESUMEN

Purpose of Review: Resilience is a key concept to deal with an uncertain future in forestry. In recent years, it has received increasing attention from both research and practice. However, a common understanding of what resilience means in a forestry context and how to operationalise it is lacking. Here, we conducted a systematic review of the recent forest science literature on resilience in the forestry context, synthesizing how resilience is defined and assessed. Recent Findings: Based on a detailed review of 255 studies, we analysed how the concepts of engineering resilience, ecological resilience and social-ecological resilience are used in forest sciences. A clear majority of the studies applied the concept of engineering resilience, quantifying resilience as the recovery time after a disturbance. The two most used indicators for engineering resilience were basal area increment and vegetation cover, whereas ecological resilience studies frequently focus on vegetation cover and tree density. In contrast, important social-ecological resilience indicators used in the literature are socioeconomic diversity and stock of natural resources. In the context of global change, we expected an increase in studies adopting the more holistic social-ecological resilience concept, but this was not the observed trend. Summary: Our analysis points to the nestedness of these three resilience concepts, suggesting that they are complementary rather than contradictory. It also means that the variety of resilience approaches does not need to be an obstacle for operationalisation of the concept. We provide guidance for choosing the most suitable resilience concept and indicators based on the management, disturbance and application context.

9.
Ultrasound Obstet Gynecol ; 56(1): 78-85, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31595598

RESUMEN

OBJECTIVE: Normal cognitive development usually requires a structurally intact and complete cerebellar vermis. The aim of this study was to evaluate whether quantification by fetal magnetic resonance imaging (MRI) of vermis- and brainstem-specific imaging markers improves the definition of cystic posterior fossa malformations (cPFM). METHODS: Fetuses diagnosed with cPFM that had an available midsagittal plane on T2-weighted MRI were identified retrospectively and compared with gestational-age (GA) matched brain-normal controls. Fetuses with cPFM were assigned to three groups, according to standard criteria (vermian size and brainstem-vermis (BV) angle): normal vermian area and BV angle < 25° (Group 1); reduced vermian area and/or BV angle of 25-45° (Group 2); and reduced vermian area and BV angle > 45° (Group 3; Dandy-Walker malformation (DWM) group). The number of differentiable vermian lobules and the areas of the vermis, mesencephalon, pons and medulla oblongata were quantified, correlated with and controlled for GA, and compared between the study groups. RESULTS: In total, 142 cases of cPFM were included, with a mean GA of 25.20 ± 5.11 weeks. Cases comprised Blake's pouch cyst (n = 46), arachnoid cyst (n = 12), inferior vermian hypoplasia (n = 5), megacisterna magna (n = 35) and classic DWM (n = 44). In the control group, 148 fetuses were included, with a mean GA of 25.26 ± 4.12 weeks. All quantified areas and the number of differentiable vermian lobules had a significant positive correlation with GA. The number of vermian lobules and the areas of all quantified regions, except for that of the medulla oblongata, differed significantly between the study groups (P ≤ 0.015 for all). The control group had the highest number of differentiable vermian lobules and the DWM group had the lowest (P < 0.01). CONCLUSIONS: Prenatal MRI assessment of vermian lobules is a useful addition to standard neuroradiological and neurosonographic techniques. The quantification of vermian lobules using fetal MRI allows further differentiation of cPFM into subgroups and thereby improves the classification of hindbrain malformations. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Síndrome de Dandy-Walker/diagnóstico por imagen , Malformaciones del Sistema Nervioso/diagnóstico por imagen , Adulto , Fosa Craneal Posterior/anomalías , Fosa Craneal Posterior/diagnóstico por imagen , Femenino , Edad Gestacional , Humanos , Recién Nacido , Imagen por Resonancia Magnética , Valor Predictivo de las Pruebas , Embarazo , Diagnóstico Prenatal
10.
NeuroRehabilitation ; 45(4): 525-536, 2019 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-31868691

RESUMEN

BACKGROUND: There is little high-level evidence for the effect of the nonverbal facilitation of swallowing on swallowing ability in the subacute stage of rehabilitation following severe acquired brain injury (ABI). OBJECTIVE: To pilot test a randomised controlled trial to determine the effect of an intensification of the nonverbal facilitation of swallowing on dysphagia. METHODS: Ten patients with severe ABI and dysphagia were randomised into two groups at a highly specialised neurorehabilitation clinic.The intervention group received an intensification of the nonverbal facilitation of swallowing and the control group received basic care of the face and mouth in addition to treatment as usual for two sessions of 20 minutes per day for three weeks.Outcomes were Functional Oral Intake Scale (FOIS), Penetration Aspiration Scale (PAS), and electrophysiological swallowing specific parameters (EMBI). RESULTS: The intensified intervention was feasible. PAS and FOIS scores improved in both groups, with no differences between groups. The swallowing specific parameters reflected clinically observed changes in swallowing. CONCLUSIONS: PAS and FOIS are feasible instruments to measure dysphagia. It is possible and valid to measure swallowing frequency and kinematics using electromyography and bioimpedance. The definitive study should have widened inclusion criteria and optimise intervention timing to maintain patient arousal.


Asunto(s)
Lesiones Encefálicas/rehabilitación , Trastornos de Deglución/rehabilitación , Deglución , Rehabilitación Neurológica/métodos , Adulto , Lesiones Encefálicas/complicaciones , Trastornos de Deglución/etiología , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto
11.
Perspect Plant Ecol Evol Syst ; 31: 44-54, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29628800

RESUMEN

The understorey harbours a substantial part of vascular plant diversity in temperate forests and plays an important functional role, affecting ecosystem processes such as nutrient cycling and overstorey regeneration. Global change, however, is putting these understorey communities on trajectories of change, potentially altering and reducing their functioning in the future. Developing mitigation strategies to safeguard the diversity and functioning of temperate forests in the future is challenging and requires improved predictive capacity. Process-based models that predict understorey community composition over time, based on first principles of ecology, have the potential to guide mitigation endeavours but such approaches are rare. Here, we review fourteen understorey modelling approaches that have been proposed during the last three decades. We evaluate their inclusion of mechanisms that are required to predict the impact of global change on understorey communities. We conclude that none of the currently existing models fully accounts for all processes that we deem important based on empirical and experimental evidence. Based on this review, we contend new models are needed to project the complex impacts of global change on forest understoreys. Plant functional traits should be central to such future model developments, as they drive community assembly processes and provide valuable information on the functioning of the understorey. Given the important role of the overstorey, a coupling of understorey models to overstorey models will be essential to predict the impact of global change on understorey composition and structure, and how it will affect the functioning of temperate forests in the future.

12.
For Ecol Manage ; 388: 43-56, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-28860675

RESUMEN

Natural disturbances, such as avalanches, snow breakage, insect outbreaks, windthrow or fires shape mountain forests globally. However, in many regions over the past centuries human activities have strongly influenced forest dynamics, especially following natural disturbances, thus limiting our understanding of natural ecological processes, particularly in densely-settled regions. In this contribution we briefly review the current understanding of changes in forest cover, forest structure, and disturbance regimes in the mountain forests across the European Alps over the past millennia. We also quantify changes in forest cover across the entire Alps based on inventory data over the past century. Finally, using the Swiss Alps as an example, we analyze in-depth changes in forest cover and forest structure and their effect on patterns of fire and wind disturbances, based on digital historic maps from 1880, modern forest cover maps, inventory data on current forest structure, topographical data, and spatially explicit data on disturbances. This multifaceted approach presents a long-term and detailed picture of the dynamics of mountain forest ecosystems in the Alps. During pre-industrial times, natural disturbances were reduced by fire suppression and land-use, which included extraction of large amounts of biomass that decreased total forest cover. More recently, forest cover has increased again across the entire Alps (on average +4% per decade over the past 25-115 years). Live tree volume (+10% per decade) and dead tree volume (mean +59% per decade) have increased over the last 15-40 years in all regions for which data were available. In the Swiss Alps secondary forests that established after 1880 constitute approximately 43% of the forest cover. Compared to forests established previously, post-1880 forests are situated primarily on steep slopes (>30°), have lower biomass, a more aggregated forest structure (primarily stem-exclusion stage), and have been more strongly affected by fires, but less affected by wind disturbance in the 20th century. More broadly, an increase in growing stock and expanding forest areas since the mid-19th century have - along with climatic changes - contributed to an increasing frequency and size of disturbances in the Alps. Although many areas remain intensively managed, the extent, structure, and dynamics of the forests of the Alps reflect natural drivers more strongly today than at any time in the past millennium.

13.
HNO ; 64(2): 117-21, 2016 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-26795738

RESUMEN

BACKGROUND/OBJECTIVE: Osteoradionecrosis is a rare, but feared, late complication after radiotherapy of the head and neck region. Its localization to the sternoclavicular joint has rarely been described so far. MATERIALS AND METHODS: Data are from a retrospective study that included all patients admitted to the authors' clinic with osteoradionecrosis of the sternoclavicular joint during the last 5 years. Therapy and outcome were evaluated and compared to the established literature. RESULTS: Over the past 5 years, 2 patients have been treated for pronounced osteoradionecrosis of the sternoclavicular joint. Both patients had received postoperative radiotherapy for tumors of the neck and chest, and presented with lesions involving the clavicle and the sternum. After eliminating the suspicion of recurrent cancer, both radiologic imaging and histopathologic evaluation confirmed an infection. Aggressive debridement with partial claviculectomy, partial sternectomy, and reconstruction using a pectoralis flap lead to the patients' recovery. CONCLUSION: Osteoradionecrosis does not only affect bone, but also the surrounding soft tissue. Due to the changes associated with previous radiotherapy, osteoradionecrosis should always be treated with radical debridement of the infected area, followed by flap reconstruction using unaffected tissue. The prognosis for the patient is then good.


Asunto(s)
Neoplasias Pulmonares/radioterapia , Osteorradionecrosis/etiología , Osteorradionecrosis/cirugía , Articulación Esternoclavicular/efectos de la radiación , Articulación Esternoclavicular/cirugía , Anciano , Artroplastia/métodos , Terapia Combinada/métodos , Desbridamiento/métodos , Femenino , Humanos , Neoplasias Pulmonares/complicaciones , Masculino , Osteorradionecrosis/diagnóstico , Procedimientos de Cirugía Plástica/métodos , Esternotomía/métodos , Colgajos Quirúrgicos , Resultado del Tratamiento
14.
HNO ; 63(6): 439-46, 2015 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-26059790

RESUMEN

BACKGROUND: To allow passage of food, the swallowing process closes off the larynx and interrupts respiratory flow. Both the timing of the interruption of respiratory flow and the body position can affect the results of the swallowing process. OBJECTIVE: The effect of body position on the swallowing process and the coordination of breathing and swallowing is investigated. MATERIALS AND METHOD: A combined EMG/bioimpedance measurement system and a piezoelectric sensor were used to investigate coordination of breathing and swallowing of a range of food consistencies in three different body positions (90°, 45° and 0°) in healthy subjects. RESULTS: Investigations were carried out on 21 healthy subjects (12 ♂, 9 ♀). 762 swallows were recorded. Changing body position was found to have a statistically significant effect on swallow-related parameters (maximum laryngeal elevation and speed of laryngeal elevation) and breathing pattern (pre- and post-swallow breathing phases). The laryngeal elevation as well as the speed of the laryngeal elevation is influenced significantly by the consistency to be swallowed. The breathing pattern changes from saliva to solid food of inspiration/swallow/inspiration to expiration/swallow/expiration. A change of body position influences the parameters specific for swallowing and the breathing patterns significantly. CONCLUSIONS: This study demonstrates that body position affects coordination of breathing and swallowing and swallow-related parameters in healthy subjects. Our results indicate that patients should be enabled to adopt a position in which they are sitting at an angle of at least 45°.


Asunto(s)
Deglución/fisiología , Conducta Alimentaria/fisiología , Postura/fisiología , Mecánica Respiratoria/fisiología , Actigrafía/métodos , Adaptación Fisiológica/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pletismografía de Impedancia/métodos , Adulto Joven
18.
Phys Rev Lett ; 111(6): 062002, 2013 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-23971562

RESUMEN

Measurements of inclusive differential cross sections for charged pion and kaon production in e+ e- annihilation have been carried out at a center-of-mass energy of sqrt[s]=10.52 GeV. The measurements were performed with the Belle detector at the KEKB e+ e- collider using a data sample containing 113×10(6) e+ e- → qq events, where q={u,d,s,c}. We present charge-integrated differential cross sections dσ(h±)/dz for h±={π±,K±} as a function of the relative hadron energy z=2E(h)/sqrt[s] from 0.2 to 0.98. The combined statistical and systematic uncertainties for π± (K±) are 4% (4%) at z∼0.6 and 15% (24%) at z∼0.9. The cross sections are the first measurements of the z dependence of pion and kaon production for z>0.7 as well as the first precision cross section measurements at a center-of-mass energy far below the Z0 resonance used by the experiments at LEP and SLC.

19.
HNO ; 60(3): 279-81, 2012 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-22286303

RESUMEN

MEDICAL HISTORY: A 49-year-old woman was referred to the ENT department with a 1.5-year history of dysphagia accompanied by globus sensation and regurgitation as well as recurrent syncopal attacks associated with swallowing solid foods. CLINICAL FINDINGS: Endoscopic examination revealed hyperplasia of the tongue base and redness of the aryepiglottic region. An axial hiatal hernia (> 3 cm) was seen on esophago-gastro-duodenoscopy. Esophageal manometry showed a diffuse esophageal spasm. Holter monitoring (24 h) revealed a third-degree atrioventricular block. THERAPY: The patient's symptoms resolved following placement of a permanent cardiac pacemaker. Globus sensation and regurgitation persisted. Treatment with proton pump inhibitors was successful. The final functional endoscopic evaluation of swallowing revealed no relevant findings. CONCLUSION: We describe a case of a rare and extreme form of a vagal reflex. Deglutition syncope can be successfully treated by a multidisciplinary team consisting of otorhinolaryngologists, neurologists and cardiologists.


Asunto(s)
Bloqueo Atrioventricular/diagnóstico , Bloqueo Atrioventricular/prevención & control , Marcapaso Artificial , Síncope/diagnóstico , Síncope/prevención & control , Bloqueo Atrioventricular/complicaciones , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Síncope/etiología , Resultado del Tratamiento
20.
Phys Rev Lett ; 107(7): 072004, 2011 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-21902387

RESUMEN

The interference fragmentation function translates the fragmentation of a quark with a transverse projection of the spin into an azimuthal asymmetry of two final-state hadrons. In e(+)e(-) annihilation the product of two interference fragmentation functions is measured. We report nonzero asymmetries for pairs of charge-ordered π(+)π(-) pairs, which indicate a significant interference fragmentation function in this channel. The results are obtained from a 672 fb(-1) data sample that contains 711 × 10(6) π(+)π(-) pairs and was collected at and near the Υ(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...