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1.
Phys Rev Lett ; 128(1): 011801, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35061499

RESUMO

Dark matter with Planck-scale mass (≃10^{19} GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19} GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18} cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

2.
Phys Rev Lett ; 115(7): 071801, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26317713

RESUMO

A new measurement of the branching ratio R_{e/µ}=Γ(π^{+}→e^{+}ν+π^{+}→e^{+}νγ)/Γ(π^{+}→µ^{+}ν+π^{+}→µ^{+}νγ) resulted in R_{e/µ}^{exp}=[1.2344±0.0023(stat)±0.0019(syst)]×10^{-4}. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.

3.
Phys Rev Lett ; 111(13): 132504, 2013 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-24116774

RESUMO

A measurement of beam helicity asymmetries in the reaction 3He[over →](e[over →],e'n)pp is performed at the Mainz Microtron in quasielastic kinematics to determine the electric to magnetic form factor ratio of the neutron GEn/GMn at a four-momentum transfer Q2=1.58 GeV2. Longitudinally polarized electrons are scattered on a highly polarized 3He gas target. The scattered electrons are detected with a high-resolution magnetic spectrometer, and the ejected neutrons are detected with a dedicated neutron detector composed of scintillator bars. To reduce systematic errors, data are taken for four different target polarization orientations allowing the determination of GEn/GMn from a double ratio. We find µnGEn/GMn=0.250±0.058(stat)±0.017(syst).

4.
MedEdPORTAL ; 18: 11265, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35892044

RESUMO

Introduction: Procedural training is a universal concern amongst pediatric residents and their teachers. We developed and implemented formative assessments to generate direct and indirect procedural feedback. We analyzed changes in residents' perceived procedural knowledge, skills, confidence, and entrustment. Methods: Senior pediatric residents rotating in the pediatric emergency department participated in video-recorded formative assessments of informed consent OSCEs and simulated toddler forehead laceration repair and infant lumbar puncture. Residents reflected on their perceived procedural knowledge, skills, confidence, and entrustment through Likert and entrustment scales. Secondary outcomes of formative assessment completion rates and proportions of procedures performed by pediatric residents tracked feasibility and potential clinical impact, respectively. Results: Including the pilot period, 89% of residents (31 out of 35) received direct and indirect procedural feedback. Perceived composite competency and entrustment improved for laceration repair (competency: from 3.1 to 3.9, p < .001; entrustment: from 4.0 to 5.1, p < .001) and lumbar puncture (competency: from 3.5 to 4.0, p < .001; entrustment: from 4.6 to 5.6, p = .001). We observed an increase in the proportion of clinical laceration repairs (11% [97 out of 885] vs. 23% [218 out of 946], p < .001) and lumbar punctures (23% [12 out of 54] vs. 41% [21 out of 52], p = .05) performed by pediatric residents. Discussion: Integrating feasible procedural formative assessments into the pediatric emergency department rotation had a positive impact on senior pediatric residents' perceptions of their procedural knowledge, skills, confidence, and entrustment and was associated with increased procedural engagement.


Assuntos
Internato e Residência , Lacerações , Competência Clínica , Serviço Hospitalar de Emergência , Humanos , Lacerações/cirurgia , Pediatria
5.
Eur Phys J C Part Fields ; 81(9): 823, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720726

RESUMO

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

6.
Phys Rev Lett ; 105(24): 242001, 2010 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-21231520

RESUMO

New precise results of a measurement of the elastic electron-proton scattering cross section performed at the Mainz Microtron MAMI are presented. About 1400 cross sections were measured with negative four-momentum transfers squared up to Q² = 1 (GeV/c)² with statistical errors below 0.2%. The electric and magnetic form factors of the proton were extracted by fits of a large variety of form factor models directly to the cross sections. The form factors show some features at the scale of the pion cloud. The charge and magnetic radii are determined to be ½ = 0.879(5)stat(4)syst(2)model(4)group fm and ½ = 0.777(13)stat(9)syst(5)model(2)group fm.

7.
Acad Pediatr ; 19(7): 815-821, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31200029

RESUMO

OBJECTIVE: Shortages of pediatric subspecialists exist in many fields with insufficient recruitment of new fellows. The current system of funding graduate medical education is inadequate. We examined funding sources for trainee salary and educational expenses in pediatric fellowship programs, effects of funding constraints, and program characteristics associated with financial insecurity as reported by fellowship program directors (FPD). METHODS: We conducted a national survey of FPD between November 1, 2016 and February 9, 2017. We used multivariable logistic regression to examine the association between perceived financial insecurity, program characteristics, and funding sources for fellow salary. RESULTS: We obtained data from 519 FPD, representing 14 different pediatric subspecialties. FPD reported that funding limitations restricted program size and educational resources in 22% and 36% of programs, respectively. Nineteen percent of FPD perceived funding of their program to be insecure. Programs with 7 or more fellows (OR .50 [95% CI .27-.90], P = .03) or hospital or graduate medical education/Children's Hospital graduate medical education funding (OR .58 [95% CI .35-.96], P = .04) were less likely to be perceived as insecure. Conversely, programs with extramural (OR 1.74 [95% CI 1.07-2.81], P = .03) or division funding (OR 1.70 [95% CI 1.02-2.82], P = .04) or in subspecialties with more than 25% unfilled positions or programs (OR 1.86 [95% CI 1.11-3.09], P = .02) were more likely to be perceived as insecure. CONCLUSIONS: Perceived financial insecurity of fellowship programs was strongly associated with program size, funding source, and unfilled positions, limiting recruitment and resources. Stable funding of fellowship programs is critical to maintain an adequate pediatric subspecialty workforce.


Assuntos
Bolsas de Estudo/organização & administração , Administração Financeira/organização & administração , Internato e Residência/economia , Pediatria/educação , Humanos , Inquéritos e Questionários , Estados Unidos
9.
J Clin Oncol ; 16(6): 2093-104, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9626209

RESUMO

PURPOSE: To evaluate the reliability of CD34/CD33 subset enumeration as a predictor of hematopoietic repopulating potential in autologous blood stem-cell transplantation and to determine which patient and treatment-related factors affect the timing, quantity, and type of blood stem cells mobilized. PATIENTS AND METHODS: We analyzed blood stem-cell collections from 410 consecutive cancer patients who received mobilization therapy and evaluated factors, including CD34+ subset quantities, that might influence engraftment kinetics and transfusion requirements in autologous blood stem-cell recipients. RESULTS: The majority of patients (97%) mobilized CD34+33- cells, which were usually collected in the greatest quantity on the first day of apheresis. Patients who received only growth factor mobilized the highest percentage of CD34+33- cells. Extensive prior chemotherapy limited the collection of CD34+33- cells. In addition to patient diagnosis (P < .006) and total CD34+ cell dose (P = .0001), CD34+33- cell dose (P < .005) and percentage of CD34+33- cells (P < .005) were identified as independent factors significantly predictive of engraftment kinetics. CD34+33- cell dose (R2 < or = .177; P < .0001) was a strong and the only significant predictor of RBC and platelet transfusion requirements. Furthermore, independent of the total CD34+ cell dose, as the CD34+33- cell dose increased, days to neutrophil recovery, days to platelet recovery, and transfusion requirements decreased. CONCLUSION: These findings show that CD34+33- cells are readily collected in most cancer patients and significantly influence engraftment kinetics and transfusion requirements in autologous blood stem-cell recipients. CD34+33- cell quantity of the blood stem-cell graft appears to be a more reliable predictor of hematopoietic recovery rates than total CD34+ cell quantity in this setting.


Assuntos
Antígenos CD34/fisiologia , Antígenos CD/fisiologia , Antígenos de Diferenciação Mielomonocítica/fisiologia , Sobrevivência de Enxerto/imunologia , Transplante de Células-Tronco Hematopoéticas , Transplante Autólogo/fisiologia , Adolescente , Adulto , Idoso , Contagem de Células Sanguíneas , Criança , Pré-Escolar , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Sobrevivência de Enxerto/efeitos dos fármacos , Mobilização de Células-Tronco Hematopoéticas , Humanos , Subpopulações de Linfócitos/fisiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico
10.
Hum Mutat ; 14(4): 353-4, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10502832

RESUMO

Hereditary motor and sensory neuropathies (HMSN) comprises a wide clinical spectrum of related disorders with defects in peripheral nerve myelination. Charcot-Marie-Tooth type 1 (CMT1) is the most common form and is usually a mild disease with onset in the first or second decade; however there is a interfamilial and intrafamilial clinical variation, ranging from asymptomatic expression to severe muscular weakness and atrophy. Recently point mutations in the early growth response 2 gene (EGR2/Krox-20) have been associated with hereditary myelinopathies. We investigated for mutations at the EGR2 gene a patient with severe CMT1 phenotype. Direct sequencing of EGR2 gene showed a heterozygous A T transversion at nucleotide 1064 that predicts an Asp305Val substitution within the first zinc-finger domain. The finding of a novel EGR2 mutation associated with a different phenotype confirms that peripheral neuropathies represent a continuum spectrum of related disorders due to an underlying defect in myelination.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Substituição de Aminoácidos , Criança , Cromossomos Humanos Par 17 , Proteína 2 de Resposta de Crescimento Precoce , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Mutação Puntual , Polimorfismo Conformacional de Fita Simples , Dedos de Zinco/genética
11.
Life Sci ; 46(1): 67-72, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2299970

RESUMO

Lipid peroxidation products were measured in the plasma of 24 kidney transplant patients and 12 healthy volunteers (controls) by: (1) 2-thiobarbituric acid assay and (2) the intensity of fluorescence products of malonaldehyde cross-linked proteins. Plasma levels of creatinine, ceruloplasmin, transferrin, prealbumin, albumin and total protein were also measured. Elevated lipid peroxidation products and lowered transferrin levels were observed in transplant patients compared to controls. Ceruloplasmin levels were slightly but significantly elevated in recent transplant recipients (less than 6 months, n = 12, Group A) while no difference was observed between older transplant recipients (greater than 6 months, n = 12, Group B) and controls. Serum, creatinine levels were also slightly but significantly elevated in both groups of patients compared to controls. Serum prealbumin, albumin and total protein levels in both groups of transplant recipients were not different from controls or reference range values.


Assuntos
Transplante de Rim/fisiologia , Peroxidação de Lipídeos , Transferrina/análise , Proteínas Sanguíneas/análise , Ceruloplasmina/análise , Creatinina/sangue , Feminino , Humanos , Masculino , Pré-Albumina/análise , Albumina Sérica/análise , Fatores de Tempo
12.
Pediatr Med Chir ; 3(2-3): 135-40, 1981.
Artigo em Italiano | MEDLINE | ID: mdl-6283484

RESUMO

ACTH therapy induces transient behaviour disturbances (irritability, restlessness or drowsiness and apathy), parallel to the EEG. changes. These behaviour abnormalities have a positive relationship with cortisolemic levels and clinical results. A clear relationship between ACTH therapy and pseudoatrophic CT findings can be observed.


Assuntos
Hormônio Adrenocorticotrópico/efeitos adversos , Transtornos do Comportamento Infantil/induzido quimicamente , Epilepsia/tratamento farmacológico , Hormônio Adrenocorticotrópico/uso terapêutico , Atrofia/induzido quimicamente , Encéfalo/patologia , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino
13.
Pediatr Med Chir ; 3(2-3): 141-6, 1981.
Artigo em Italiano | MEDLINE | ID: mdl-6178085

RESUMO

The clinical entity epilepsy-aphasia in children begins from an analytical study of cases published in the literature and from the study of eight cases personally observed. This condition is not an univocal syndrome but it must be differentiated into at least three different conditions even if, very often, they are superimposed: 1) a first condition in which the aphasia is critical and transient; 2) a second condition where it acts rather as a serious congenital dysphasia, and 3) a third condition in which it acts as an acquired aphasia, in the strict sense, even though very atypical. The relation between aphasia and epilepsy are discussed especially for what concerns the dynamic of the diffusive forms of epilepsy in the child and psychiatric aspects. Both the pharmacological and reeducative problems of therapy are discussed.


Assuntos
Afasia/complicações , Epilepsia/complicações , Fatores Etários , Afasia/classificação , Afasia/etiologia , Criança , Eletroencefalografia , Humanos , Síndrome
14.
Pediatr Med Chir ; 3(2-3): 159-64, 1981.
Artigo em Italiano | MEDLINE | ID: mdl-7343909

RESUMO

Neurological and psychic side effects of anticonvulsivant drugs in pediatric age are separately considered. Neurological side effects are classified according to different ages: in the neonatal period sedation is preeminent, later psychomotor deterioration or cerebellar and/or extrapyramidal signs may occur. Less frequently antiepileptic drugs are responsible of worsening of seizures up to a toxic encephalopathy. Psychic side effects are more variable and unpredicatable. The same drugs can cause both psychomotor excitement or psychic slowness. In a few instances psychotic syndromes can be observed. Very important are chronic side effects on intellectual activities, especially in children. Finally some factors which can affect the interpretation of the side effects have to be considered: pharmacokinetic data individual reactivity, methodology of evaluation of clinical symptoms, especially psychic ones.


Assuntos
Anticonvulsivantes/efeitos adversos , Encéfalo/efeitos dos fármacos , Fatores Etários , Agressão/efeitos dos fármacos , Anticonvulsivantes/sangue , Ataxia/induzido quimicamente , Criança , Pré-Escolar , Eletroencefalografia , Meia-Vida , Humanos , Lactente , Recém-Nascido , Testes Psicológicos , Convulsões/induzido quimicamente , Vigília/efeitos dos fármacos
20.
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