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1.
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
2.
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.

3.
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.

5.
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
6.
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%.

7.
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).

9.
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.

10.
Phys Rev Lett ; 99(13): 132301, 2007 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-17930579

RESUMO

The beam-recoil double polarization P(x')(h) and P(z')(h) and the recoil polarization P(y') were measured for the first time for the p(e,e'p)eta reaction at a four-momentum transfer of Q(2) = 0.1 GeV(2)/c(2) and a center of mass production angle of theta = 120 degrees at the Mainz Microtron MAMI-C. With a center of mass energy range of 1500 MeV

11.
Neurobiol Dis ; 8(4): 700-6, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11493034

RESUMO

Mutations in the early growth response 2 (EGR2) gene are associated with some forms of Charcot--Marie--Tooth disease (CMT) and other demyelinating neuropathies. These mutations modify the EGR2 binding to specific DNA sequences suggesting a role in the transcriptional control of myelination-specific genes. Here we show that the D355V mutation, associated with a CMT case combining axonal and demyelinating abnormalities, reduces three times the affinity of EGR2 to its consensus sequence and ten times its affinity to a sequence in the human Cx32 promoter. These findings could indicate that this EGR2 mutation leads to the development of CMT1 through the transcriptional deregulation of Cx32 gene.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Conexinas/genética , Proteínas de Ligação a DNA/metabolismo , Mutação Puntual , Regiões Promotoras Genéticas/fisiologia , Fatores de Transcrição/metabolismo , Adolescente , Ligação Competitiva/fisiologia , Doença de Charcot-Marie-Tooth/metabolismo , Criança , Proteína 2 de Resposta de Crescimento Precoce , Feminino , Expressão Gênica/fisiologia , Humanos , Bainha de Mielina/fisiologia , Transcrição Gênica/fisiologia , Proteína beta-1 de Junções Comunicantes
12.
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
13.
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
14.
J Hematother ; 7(1): 53-61, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9507381

RESUMO

Peripheral blood progenitor cells (PBPC) reside within the mononuclear cell (MNC) component of the blood and can be collected using a number of apheresis devices, including the Fenwal CS3000 Plus Blood Cell Separator. Increased MNC collection efficiency, therefore, may reduce the number of apheresis required to achieve collection goals. In this study, patients were divided into groups by absolute MNC count to determine the effect of interface detector offset (I/O) adjustment on MNC collection efficiency. Apheresis products from 104 procedures collected using a standard I/O setting of 100 were compared with 121 collections for which the I/O setting was adjusted according to the preapheresis MNC count. Adjustment of the I/O setting in this manner had no statistically significant impact on the per kilogram dose of MNC collected. The data did show that MNC collection efficiency was reduced as both the MNC count and I/O setting increased, as the collection efficiency was greatest for patients with the lowest peripheral MNC counts and was inversely correlated with the preapheresis MNC count. Although contamination of the product with platelets was drastically reduced at higher I/O settings, there was a concomitant rise in RBC contamination. We conclude that a standard setting of 100 is preferable to adjustment of the I/O setting as a function of the preapheresis MNC count.


Assuntos
Coleta de Amostras Sanguíneas/instrumentação , Separação Celular/instrumentação , Células-Tronco Hematopoéticas/citologia , Leucaférese/instrumentação , Leucócitos Mononucleares/citologia , Adulto , Idoso , Contagem de Células , Feminino , Neoplasias Hematológicas/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/terapia
15.
Cancer ; 73(8): 2042-7, 1994 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-8156508

RESUMO

BACKGROUND: Hepatic arterial infusion chemotherapy (HAIC) of liver metastases of colon cancer with an implantable pump is associated with liver and gastrointestinal complications. METHODS: The authors retrospectively studied the clinical features and gastric histopathology of nine patients who received HAIC and had gastritis develop and in whom biopsy specimens were available. RESULTS: Gastritis was heralded in these patients by epigastric pain and tenderness, nausea, vomiting, weakness, and anorexia. In seven patients, 18 gastric ulcers were endoscopically detected. Mucosal damage developed despite prophylactic antiulcer therapy and healed only upon cessation of HAIC. These observations suggest that the predominant drug given, floxuridine, was the responsible toxic agent. Seventeen biopsy specimens were reviewed, and all exhibited varied histologic evidence of inflammation, reactive glandular changes, and cell necrosis. These mucosal changes were present even in tissues obtained from patients without ulcers. In addition, floxuridine-induced glandular atypia was noted in eight biopsy samples from six patients. The crowded glands were distorted and lined by large cells that included bizarre forms with pleomorphic nuclei. CONCLUSIONS: Gastric injury in HAIC appeared analogous to the general features encountered in reactive gastritis resulting from chemical irritants. The glandular atypia is peculiar to HAIC, and although the changes were morphologically alarming, in this clinical situation care should be exercised not to interpret floxuridine-induced atypia as carcinoma.


Assuntos
Neoplasias do Colo/patologia , Floxuridina/administração & dosagem , Floxuridina/efeitos adversos , Mucosa Gástrica/efeitos dos fármacos , Gastrite/induzido quimicamente , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Úlcera Gástrica/induzido quimicamente , Adulto , Idoso , Biópsia , Feminino , Mucosa Gástrica/patologia , Gastrite/patologia , Artéria Hepática , Humanos , Bombas de Infusão Implantáveis , Infusões Intra-Arteriais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Úlcera Gástrica/patologia
16.
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
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