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1.
Phys Rev Lett ; 112(18): 182501, 2014 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-24856691

RESUMO

The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π(±) electroproduction on the deuteron at central Q(2) values of 0.6, 1.0, 1.6 GeV(2) at W=1.95 GeV, and Q(2)=2.45 GeV(2) at W=2.22 GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.

2.
Int J Clin Pract ; 67(6): 566-75, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23679908

RESUMO

BACKGROUND: Few studies conducted outside of Asia have shown that lower urinary tract symptoms (LUTS) could be a concern for cancer patients. This gap necessitates more research on LUTS among cancer patients in Asia, particularly regarding associated factors and the relationship between quality of life and LUTS. OBJECTIVES: This study investigates the prevalence, associated factors, and relationship to quality of life of LUTS based on a sample of cancer patients. DESIGN: A cross-sectional, questionnaire survey. SETTINGS/PARTICIPANTS: This study was conducted at two oncology outpatient departments in two hospitals in Taiwan, and included 134 Asian cancer patients. METHODS: We collected information about each participant's individual characteristics, personal habits, LUTS, and quality of life by using a questionnaire. We calculated descriptive statistics to demonstrate the distribution of collected information, and used multivariate logistic regression to identify the factors associated with LUTS. We used Student's t-test to compare the mean quality of life scores for participants with and without LUTS. RESULTS: Ninety-nine (73.9%) participants experienced at least one type of LUTS, and the prevalence rates for various types of LUTS ranged from 3.7% to 52.2%. Radiotherapy and the time since the diagnosis of cancer were associated with LUTS. Participants with LUTS reported lower quality of life scores than participants without LUTS. CONCLUSIONS: The high prevalence of LUTS suggests that cancer treatment might be linked to LUTS, which in turn has a negative effect on a patient's quality of life. These results suggest that future research should involve studies in larger, more homogeneous samples. Health care providers should monitor the presence of LUTS and deliver the management and treatments of LUTS to optimise cancer patients' quality of life.


Assuntos
Sintomas do Trato Urinário Inferior/complicações , Neoplasias/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Hábitos , Humanos , Sintomas do Trato Urinário Inferior/epidemiologia , Sintomas do Trato Urinário Inferior/psicologia , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Neoplasias/psicologia , Aceitação pelo Paciente de Cuidados de Saúde , Projetos Piloto , Prevalência , Qualidade de Vida , Fatores de Risco , Inquéritos e Questionários , Taiwan/epidemiologia
3.
Phys Rev Lett ; 108(12): 122002, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22540573

RESUMO

The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d(Δ)- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d(Δ)- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A(γ)-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A(γ)-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V(ud)/V(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.

4.
Phys Rev Lett ; 108(9): 092502, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22463628

RESUMO

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

5.
Phys Rev Lett ; 107(2): 022501, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21797598

RESUMO

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasielastic scattering on the deuteron, at backward angles (lab scattering angle of 108°) for Q² = 0.22 GeV²/c² and 0.63 GeV²/c² at beam energies of 362 and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single-photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (πN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasistatic deuterium approximation, and is also in agreement with theory.

6.
Phys Rev Lett ; 105(21): 212502, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21231294

RESUMO

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.

7.
Phys Rev Lett ; 104(1): 012001, 2010 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-20366359

RESUMO

We have measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q2=0.22 and 0.63 GeV2. They are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of approximately < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial-vector current at these four-momentum transfers.

8.
Phys Rev Lett ; 103(20): 202301, 2009 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-20365978

RESUMO

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from (2)H, (3)He, (4)He, (9)Be and (12)C for 0.3 < x < 0.9, Q(2) approximately 3-6 GeV(2). These data represent the first measurement of the EMC effect for (3)He at large x and a significant improvement for (4)He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.

9.
FEBS Lett ; 434(3): 351-6, 1998 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-9742953

RESUMO

pH-sensitive liposomes composed of dioleoylphosphatidylethanolamine and cholesterol hemisuccinate (3:2 mol/mol) bearing the N-acetylglucosamine derivative of bovine serum albumin (N-Ac-BSA) were applied for receptor-mediated delivery in chicken hepatoma (LMH) cells expressing the N-Ac-BSA-binding asialoglycoprotein receptor. Fluorescently labeled dextran was entrapped in liposomes by a modified freeze-thawing method (encapsulation efficiency of 23%). A novel method of coupling proteins onto the surface of preformed liposomes yielded a coupling efficiency of 60-70%. The association of pH-sensitive and lecithin liposomes with LMH cells was monitored by fluorescence-activated cell sorting and confocal microscopy. Prerequisites for receptor-mediated delivery to LMH cells were both the pH sensitivity of liposomes and the presence of N-Ac-BSA on the liposomal surface.


Assuntos
Neoplasias Hepáticas Experimentais/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Receptor de Asialoglicoproteína , Separação Celular , Galinhas , Dextranos , Citometria de Fluxo , Fluoresceína-5-Isotiocianato/análogos & derivados , Concentração de Íons de Hidrogênio , Lipossomos , Neoplasias Hepáticas Experimentais/patologia , Microscopia Confocal
10.
J Am Soc Echocardiogr ; 11(5): 436-41, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9619615

RESUMO

Dobutamine-induced hypotension has been disregarded as a marker of more severe functional abnormalities in patients with suspected coronary artery disease. However, its functional significance in patients with myocardial infarction has not been studied. The aim of this study was to define the predictors of systolic blood pressure (SBP) response to dobutamine in patients with previous myocardial infarction. Dobutamine stress (up to 40 microg/kg per minute) echocardiography was performed in 326 patients with prior myocardial infarction referred for evaluation of myocardial ischemia. A 16-segment, four-grade score model was used to assess left ventricular function. Wall motion score index was derived by summation of wall motion score divided by 16. SBP and heart rate increased from rest to peak dobutamine stress (127 +/- 22 vs 134 +/- 27 mm Hg and 72 +/- 14 vs 122 +/- 24 bpm, p < 0.00001 in both). An increase of SBP > or = 30 mm Hg occurred in 50 patients (15%). By multivariate analysis, independent predictors of failure of SBP increase were higher peak wall motion score index (p < 0.001), higher resting SBP (p < 0.01), and medication with calcium channel blockers (p < 0.05). SBP drop > or = 20 mm Hg occurred in 54 patients (17%). Independent predictors of SBP drop were higher resting wall motion score index (p < 0.001), higher resting SBP (p < 0.0001), and older age (p < 0.05). In patients with myocardial infarction, left ventricular function and baseline systolic blood pressure are powerful predictors of SBP response to dobutamine stress testing.


Assuntos
Agonistas Adrenérgicos beta , Pressão Sanguínea/efeitos dos fármacos , Dobutamina , Ecocardiografia/métodos , Infarto do Miocárdio/fisiopatologia , Angiografia Coronária , Feminino , Humanos , Hipotensão/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/diagnóstico por imagem , Função Ventricular Esquerda/fisiologia
11.
J Food Prot ; 64(9): 1309-14, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11563505

RESUMO

Application of cow manure and composted manure in agricultural practice could potentially cause contamination of foodstuffs with pathogenic bacteria such as Salmonella Enteritidis and Escherichia coli O157:H7. In this study, rifampicin-resistant (RifR) E. coli O157:H7 and Salmonella Enteritidis at a level of 7 log CFU/g of raw compost feed were used to determine the effect of a bench-scale composting system on their survival. RifR E. coli O157:H7 was not detected after 72 h of composting at 45 degrees C, and RifR Salmonella Enteritidis was not detected after 48 h. The use of selective media for enrichment failed to recover in the composting samples held at 45 degrees C for 96 h. However, the pathogens showed no change in bacterial numbers when the composting system was held at room temperature. Thus, properly composted manure can be safely used in food crop production while minimizing the likelihood of microbial contamination.


Assuntos
Escherichia coli O157/crescimento & desenvolvimento , Esterco/microbiologia , Salmonella enteritidis/crescimento & desenvolvimento , Animais , Bovinos , Contagem de Colônia Microbiana , Resistência Microbiana a Medicamentos , Escherichia coli O157/isolamento & purificação , Rifampina/farmacologia , Salmonella enteritidis/isolamento & purificação , Temperatura , Fatores de Tempo
12.
Clin Nucl Med ; 10(12): 861-4, 1985 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-4075683

RESUMO

Asymptomatic myocardial disease has been described in relation to longstanding insulin-dependent diabetes mellitus. To detect myocardiopathy in a selected group of 14 patients (aged 21-38 years, duration of diabetes 10-20 years) with insulin-dependent diabetes, we have performed equilibrium gated nuclear angiography with Fourier filtered analysis. These patients had no clinical or echocardiographic signs of cardiac disease. We examined six patients with severe proliferative retinopathy, and eight patients with no signs of retinopathy at fluorescence angiography. The global ejection fraction was within normal limits in all cases. Fourier analysis of scintigraphic data, however, revealed wall motion abnormalities (abnormal amplitude and phase shift) of the left ventricle in all 14 patients, particularly in the anterior and/or septal region. No correlation was found between the degree of wall motion disturbances and prevailing blood glucose or HbA1 concentrations or the presence of retinopathy or autonomic neuropathy. It is concluded that equilibrium gated nuclear angiography in combination with Fourier filtered analysis is a sensitive method of detecting myocardial abnormalities in patients suffering from insulin-dependent diabetes mellitus without cardiac symptoms.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Diabetes Mellitus Tipo 1/complicações , Coração/diagnóstico por imagem , Adulto , Cardiomiopatias/fisiopatologia , Retinopatia Diabética/complicações , Feminino , Análise de Fourier , Humanos , Masculino , Cintilografia , Volume Sistólico , Medronato de Tecnécio Tc 99m
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