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2.
Phys Rev Lett ; 121(2): 022504, 2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30085714

RESUMO

Final-state kinematic imbalances are measured in mesonless production of ν_{µ}+A→µ^{-}+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the µ^{-}-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.

3.
Phys Rev Lett ; 120(22): 221805, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29906174

RESUMO

We report on multinucleon effects in low momentum transfer (<0.8 GeV/c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

4.
Phys Rev Lett ; 119(8): 082001, 2017 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-28952766

RESUMO

Charged-current ν_{µ} interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q^{2}, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q^{2} and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.

5.
Phys Rev Lett ; 119(1): 011802, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-28731762

RESUMO

Neutral-current production of K^{+} by atmospheric neutrinos is a background in searches for the proton decay p→K^{+}ν[over ¯]. Reactions such as νp→νK^{+}Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K^{+} are identified in MINERvA by reconstructing the timing signature of a K^{+} decay at rest. A sample of 201 neutrino-induced neutral-current K^{+} events is used to measure differential cross sections with respect to the K^{+} kinetic energy, and the non-K^{+} hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from π^{0} decay, which would veto a neutral-current K^{+} event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.

6.
Phys Rev Lett ; 117(11): 111801, 2016 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-27661679

RESUMO

The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current π^{0} production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26±0.02(stat.)±0.08(sys.)×10^{-39} cm^{2}. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive π^{0} production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for ν_{µ} to ν_{e} oscillations.

7.
Phys Rev Lett ; 117(6): 061802, 2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27541459

RESUMO

Neutrino-induced charged-current coherent kaon production ν_{µ}A→µ^{-}K^{+}A is a rare, inelastic electroweak process that brings a K^{+} on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than the neutrino-induced charged-current coherent pion production because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state K^{+}, µ^{-}, and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at 3σ significance.

8.
Phys Rev Lett ; 116(8): 081802, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26967410

RESUMO

The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q^{2} are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q^{2} for ν_{e} with that of similarly selected ν_{µ}-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current ν_{e} interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.

9.
Phys Rev Lett ; 116(7): 071802, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26943528

RESUMO

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current ν_{µ} interactions is combined with muon kinematics to permit separation of the quasielastic and Δ(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and Δ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced population of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.

10.
Phys Rev Lett ; 112(23): 231801, 2014 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-24972195

RESUMO

We present measurements of ν(µ) charged-current cross section ratios on carbon, iron, and lead relative to a scintillator (CH) using the fine-grained MINERvA detector exposed to the NuMI neutrino beam at Fermilab. The measurements utilize events of energies 2

11.
Phys Rev Lett ; 113(26): 261802, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25615308

RESUMO

Neutrino-induced coherent charged pion production on nuclei νµA→µ(±)π(∓)A is a rare, inelastic interaction in which a small squared four-momentum |t| is transferred to the recoil nucleus, leaving it intact in the reaction. In the scintillator tracker of MINERvA, we remove events with evidence of particles from nuclear breakup and reconstruct |t| from the final-state pion and muon. We select low |t| events to isolate a sample rich in coherent candidates. By selecting low |t| events, we produce a model-independent measurement of the differential cross section for coherent scattering of neutrinos and antineutrinos on carbon. We find poor agreement with the predicted kinematics in neutrino generators used by current oscillation experiments.

12.
Transpl Infect Dis ; 14(5): 540-7, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22726461

RESUMO

BACKGROUND: Diarrhea is a frequent and potentially severe complication in solid organ transplant (SOT) recipients. One of the most common infectious etiologies of diarrhea in these patients is Clostridium difficile. Our objective was to investigate the association of C. difficile infection (CDI) with the outcomes of hospitalized SOT patients. METHODS: We extracted all adult cases with discharge diagnoses of SOT or CDI from the United States Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality 2009 database. We collected outcome variables (mortality, length of hospital stay [LOS], hospitalization charges, complications of the transplanted organ, and colectomy), demographic information, and comorbidity data for each of the cases. The data were evaluated using univariate and multiple variable regression analyses. RESULTS: We identified 49,198 cases with SOT of which 2.7% had CDI. Univariate comparisons of cases with SOT + CDI to those with SOT-only revealed significant differences in the evaluated outcomes including in-hospital mortality (7.4% vs. 2.4%, P < 0.001), LOS (median 9 days vs. 4 days, P < 0.001), charges (median $53,808 vs. $31,488, P < 0.001), organ complications (38.1% vs. 33.9%, P < 0.001), and colectomy (1.1% vs. 0.3%, P < 0.001). Using multiple variable regression analyses, in the SOT cohort (SOT-only and SOT + CDI), CDI was independently associated with greater mortality (adjusted odds ratio [aOR] 2.48, 95% confidence interval [CI] = 2.22, 2.76, P < 0.001), longer LOS (difference 9.6 days, 95% CI = 9.3, 9.9, P < 0.001), higher charges (difference $69,647, 95% CI = $66,190, $73,104, P < 0.001), more complications of the transplanted organ (aOR 1.36, 95% CI = 1.28, 1.44, P < 0.001), and increased need for colectomy (aOR 3.10, 95% CI = 2.35, 4.08, P < 0.001). CONCLUSIONS: Our results demonstrate that CDI is associated with overall significantly worse outcomes in hospitalized patients with SOT.


Assuntos
Clostridioides difficile , Infecções por Clostridium/mortalidade , Bases de Dados Factuais , Mortalidade Hospitalar , Hospitalização/estatística & dados numéricos , Transplante de Órgãos/efeitos adversos , Adolescente , Adulto , Idoso , Infecções por Clostridium/epidemiologia , Infecções por Clostridium/microbiologia , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Razão de Chances , Transplante de Órgãos/mortalidade , Análise de Regressão , Estados Unidos , Adulto Jovem
13.
Cell Death Differ ; 13(9): 1515-22, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16397580

RESUMO

Extracellular plasminogen activator inhibitor type-2 (PAI-2) is a potent inhibitor of urokinase-type plasminogen activator (u-PA) and also acts as a multifunctional protein. However, the biological activity of intracellular PAI-2, as well as its intracellular targets, until now remain an enigma. Here, we show that pRb2/p130 and Rb1/p105, but not p107, interact with PAI-2 in both the cytoplasm and nucleus of normal primary human corneal and conjunctival epithelial cells. We provided the first in vivo evidence that a specific fragment of the PAI-2 promoter is bound simultaneously by pRb2/ p130, PAI-2, E2F5, histone deacetylase 1 (HDAC1), DNA methyltransferase 1 (DNMT1), and histone methyltransferase (SUV39H1), in normal primary human corneal epithelial cells, and by pRb2/p130, PAI-2, E2F5, HDAC1, and DNMT1, in normal primary human conjunctiva epithelial cells. Our results strongly indicate a physiological interaction between pRb family members and PAI-2, suggesting the hypothesis that pRb2/p130 and PAI-2 may cooperate in modulating PAI-2 gene expression by chromatin remodeling, in normal corneal and conjunctival cells.


Assuntos
Túnica Conjuntiva/metabolismo , Células Epiteliais/metabolismo , Epitélio Corneano/metabolismo , Inibidor 2 de Ativador de Plasminogênio/metabolismo , Proteína do Retinoblastoma/metabolismo , Proteína p107 Retinoblastoma-Like/metabolismo , Proteína p130 Retinoblastoma-Like/metabolismo , Núcleo Celular/metabolismo , Montagem e Desmontagem da Cromatina , Túnica Conjuntiva/citologia , Citoplasma/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/metabolismo , Fator de Transcrição E2F5/metabolismo , Epitélio Corneano/citologia , Histona Desacetilase 1 , Histona Desacetilases/metabolismo , Humanos , Regiões Promotoras Genéticas , Ligação Proteica
14.
J Cell Physiol ; 205(2): 295-301, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15887231

RESUMO

The purpose was to characterize plasminogen activator inhibitor type 2 (PAI-2) expression in normal human conjunctiva in vivo and in vitro. PAI-2 antigen was assayed by immunostaining and immunoblotting of extracts from normal human conjunctival epithelial lysates and conditioned media (CM) of cultured human conjunctival keratinocytes. Immunostaining of normal human conjunctival epithelia revealed that PAI-2 was found consistently in the superficial keratinocytes and, in some biopsies, also in the lower keratinocyte layers. In all cases, PAI-2 was concentrated around the cell periphery. In extracts of conjunctival epithelia and cultured conjunctival keratinocytes, PAI-2 had an apparent molecular weight of 45 kDa, consistent with the non-glycosylated form. The majority of PAI-2, approximately 90%, was cell associated, however, a small percentage of PAI-2 was released into the CM in a linear manner with time. PAI-2 in the conditioned medium had a higher molecular weight, consistent with a glycosylated form. Conjunctival PAI-2 was active, as shown by its ability to complex with a target enzyme, urokinase plasminogen activator (uPA). Although PAI-2 was detectable both in monolayer (i.e., relatively undifferentiated) conjunctival keratinocyte cultures as well as in stratified (i.e., more differentiated) cultures, steady state levels of PAI-2 were greater in the latter. PAI-2 is constitutively expressed by normal human conjunctival epithelial cells. The expression of PAI-2 throughout all epithelial layers in some biopsies of conjunctiva in vivo contrasts with the previously established distribution of PAI-2 in corneal epithelia, where it is present exclusively in the most superficial (i.e. most highly differentiated) cells. The role of PAI-2 in either tissue is unclear. However, we speculate that its distinct distribution in conjunctival versus corneal epithelia underscores inherent differences between these tissues, and may reflect specific functions of this proteinase inhibitor in both conjunctival and corneal epithelial cells.


Assuntos
Túnica Conjuntiva/enzimologia , Inibidor 2 de Ativador de Plasminogênio/metabolismo , Biópsia , Diferenciação Celular , Extratos Celulares , Células Cultivadas , Túnica Conjuntiva/citologia , Túnica Conjuntiva/cirurgia , Meios de Cultivo Condicionados/análise , Fluoresceína-5-Isotiocianato , Técnica Indireta de Fluorescência para Anticorpo , Corantes Fluorescentes , Humanos , Imuno-Histoquímica , Queratinócitos/citologia , Queratinócitos/enzimologia , Cinética , Microscopia de Fluorescência , Peso Molecular , Inibidor 2 de Ativador de Plasminogênio/química , Distribuição Tecidual , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
15.
J Invest Dermatol ; 117(3): 647-53, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11564172

RESUMO

The detergent sodium dodecyl sulfate is a well-known inducer of irritant contact dermatitis. In this study we show that sodium dodecyl sulfate induces the serine proteinase inhibitor, plasminogen activator inhibitor type 2, in epidermal keratinocytes. The enhancement in plasminogen activator inhibitor type 2 mRNA and antigen is observed both when sodium dodecyl sulfate is applied topically to normal human skin as well as when it is added to the growth medium of cultured human keratinocytes. In vitro, plasminogen activator inhibitor type 2 mRNA is increased within 4-8 h after addition of the detergent, and the increase in plasminogen activator inhibitor type 2 antigen occurs slightly later. The enhancing effect of sodium dodecyl sulfate on plasminogen activator inhibitor type 2 is not related to nonspecific cell lysis nor is it secondary to induction of tumor necrosis factor alpha. Similarities between our in vitro and in vivo findings lead us to hypothesize that sodium dodecyl sulfate may exert its effect on epidermal plasminogen activator inhibitor type 2 via interaction with the keratinocyte.


Assuntos
Epiderme/metabolismo , Queratinócitos/metabolismo , Inibidor 2 de Ativador de Plasminogênio/biossíntese , Dodecilsulfato de Sódio/farmacologia , Tensoativos/farmacologia , Células Cultivadas , Humanos , Imuno-Histoquímica , Hibridização In Situ
16.
J Speech Lang Hear Res ; 44(4): 925-40, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11521783

RESUMO

According to a prominent theory, the phonological difficulties in dyslexia are caused by an underlying general impairment in the ability to process sequences of rapidly presented, brief sounds. Two studies examined this theory by exploring the relationships between rapid auditory processing and phonological processing in a sample of 82 normally reading children (Study 1) and by comparing 17 children with dyslexia to chronological-age and reading-age control participants on these tasks (Study 2). In the normal readers, moderate correlations were found between the measure of rapid auditory processing (Auditory Repetition Task, or ART) and phonological ability. On the ART, the dyslexia group performed at a level similar to that of the reading-age control group but obtained scores that were significantly below those of the chronological-age control group. This difference was due to a subgroup of 4 children in the dyslexia group who had particular difficulty with the ART. The phonological skills of these individuals were not worse than those of the children in the dyslexia group who were unimpaired on the ART. The discussion argues that there is no evidence that phonoogical difficulties are secondary to impairments of rapid auditory processing, as measured by the ART, and highlights the need to examine the strategic and cognitive demands involved in tasks of rapid auditory processing.


Assuntos
Dislexia/diagnóstico , Percepção da Fala/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Fatores de Tempo
17.
Semin Pediatr Surg ; 4(3): 147-51, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7582884

RESUMO

Emesis is a common symptom resulting from adverse food reactions in infants. In this article the terms food allergy and food intolerance are defined and differentiated. The immunopathophysiology of food allergies is discussed along with useful diagnostic tests. Adverse reactions to common infant nutrients such as cow's milk and soy milk are described, and therapeutic use of "hypoallergenic" formulas is outlined.


Assuntos
Hipersensibilidade Alimentar/complicações , Vômito/etiologia , Doença Celíaca/complicações , Doença Celíaca/diagnóstico , Diagnóstico Diferencial , Hipersensibilidade Alimentar/diagnóstico , Humanos , Lactente , Alimentos Infantis/efeitos adversos , Recém-Nascido , Hipersensibilidade a Leite/complicações , Hipersensibilidade a Leite/diagnóstico , Proteínas de Vegetais Comestíveis/administração & dosagem , Proteínas de Vegetais Comestíveis/efeitos adversos , Proteínas de Soja
18.
Hepatology ; 21(3): 697-702, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7533124

RESUMO

Reovirus type 3 has been implicated in the origin and pathogenesis of extrahepatic biliary atresia and idiopathic neonatal hepatitis, but routine detection of this virus in hepatobiliary tissues from affected infants by culture and histological techniques has been unsuccessful. In this study, oligonucleotide primers specific to the M3 genome segment of reovirus 3 (Dearing) were used in a reverse transcriptase-mediated polymerase chain reaction technique to develop a sensitive and specific assay for the detection of reovirus 3 RNA in formalin-fixed, paraffin-embedded patient samples. Optimal reaction conditions were determined by testing infected murine tissues and preserved human liver tissue supplemented with reovirus 3. Archival specimens from 50 infants, including 14 with extrahepatic biliary atresia, 20 with idiopathic neonatal hepatitis, and 16 age-matched controls, were evaluated. Successful amplification of human albumin complementary DNA from the preserved tissues confirmed the presence of intact RNA in every patient specimen tested. Analysis of the amplification reactions by agarose gel electrophoresis and Southern blot hybridization detected the presence of reoviral RNA only once in a single patient sample. These results do not support a strong role for reovirus 3 in the development of neonatal cholestatic liver disease. The recent association of other RNA viruses of the Reoviridae family with murine liver disease and human extrahepatic biliary atresia indicates that continued investigation into a viral cause for idiopathic neonatal hepatobiliary disease is warranted.


Assuntos
Colestase/virologia , Orthoreovirus Mamífero 3/isolamento & purificação , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA , Preservação de Tecido , Animais , Sequência de Bases , Ductos Biliares Extra-Hepáticos/virologia , Atresia Biliar/virologia , Hepatite Viral Humana/virologia , Humanos , Recém-Nascido , Orthoreovirus Mamífero 3/genética , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Sondas de Oligonucleotídeos/genética , RNA Viral/análise , Infecções por Reoviridae/virologia , Estudos Retrospectivos
19.
J Pharm Pharmacol ; 42(5): 332-8, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-1976780

RESUMO

An ion exchange radiochemical assay has been developed to study the deamination of [14C]methylamine (MA) in homogenates of rat aorta and human umbilical artery, as well as in samples of human plasma. MA metabolism was found to be inhibited almost completely by 1 mM semicarbazide, but virtually unaffected by 0.1 mM clorgyline, suggesting that MA is a substrate for the semicarbazide-sensitive amino oxidase (SSAO) activities which also metabolize benzylamine (BZ) in these sources. Mean Km values for MA metabolism by aorta, umbilical artery and plasma were 182, 832 and 516 microM, respectively, with corresponding Vmax values in aorta and umbilical artery of 100 and 590 nmol (mg prot.)-1 h-1, and in plasma of 48 nmol (mL serum)-1 h-1. Kinetic constants determined for [14C]BZ metabolism in plasma (by an organic solvent extraction assay) and in umbilical artery (by the ion exchange assay) yielded mean Km values of 225 microM (plasma), 222 microM (umbilical artery), and Vmax values of 28 nmol (mL serum)-1 h-1 (plasma) and 377 nmol (mg prot.)-1 h-1 (umbilical artery). The deamination of [14C]MA was inhibited competitively by unlabelled BZ, with Ki values in umbilical artery and plasma of 220 and 172 microM, respectively. Also, metabolite formation from mixtures of [14C]BZ (200 microM) and [14C]MA (800 microM) was extremely close to that predicted for a single enzyme capable of metabolizing two alternative substrates in a competitive fashion.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Metilaminas/metabolismo , Músculo Liso Vascular/enzimologia , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/antagonistas & inibidores , Semicarbazidas/farmacologia , Aminopropionitrilo/farmacologia , Animais , Aorta Torácica/enzimologia , Clorgilina/farmacologia , Colorimetria , Diálise , Humanos , Técnicas In Vitro , Cinética , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/sangue , Proteínas/metabolismo , Ratos , Artérias Umbilicais/enzimologia
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