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1.
Phys Rev Lett ; 114(5): 055001, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25699449

RESUMO

A critical challenge facing the basic long-pulse high-confinement operation scenario (H mode) for ITER is to control a magnetohydrodynamic (MHD) instability, known as the edge localized mode (ELM), which leads to cyclical high peak heat and particle fluxes at the plasma facing components. A breakthrough is made in the Experimental Advanced Superconducting Tokamak in achieving a new steady-state H mode without the presence of ELMs for a duration exceeding hundreds of energy confinement times, by using a novel technique of continuous real-time injection of a lithium (Li) aerosol into the edge plasma. The steady-state ELM-free H mode is accompanied by a strong edge coherent MHD mode (ECM) at a frequency of 35-40 kHz with a poloidal wavelength of 10.2 cm in the ion diamagnetic drift direction, providing continuous heat and particle exhaust, thus preventing the transient heat deposition on plasma facing components and impurity accumulation in the confined plasma. It is truly remarkable that Li injection appears to promote the growth of the ECM, owing to the increase in Li concentration and hence collisionality at the edge, as predicted by GYRO simulations. This new steady-state ELM-free H-mode regime, enabled by real-time Li injection, may open a new avenue for next-step fusion development.

2.
Phys Rev Lett ; 112(18): 185004, 2014 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-24856704

RESUMO

An electrostatic coherent mode near the electron diamagnetic frequency (20-90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Superconducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond-coated reciprocating probes. The mode propagates in the electron diamagnetic direction in the plasma frame with poloidal wavelength of ∼8 cm. The mode drives a significant outflow of particles and heat as measured directly with the probes, thus greatly facilitating long pulse H-mode sustainment. This mode shows the nature of dissipative trapped electron mode, as evidenced by gyrokinetic turbulence simulations.

3.
Phys Rev Lett ; 110(23): 235002, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25167503

RESUMO

Strong mitigation of edge-localized modes has been observed on Experimental Advanced Superconducting Tokamak, when lower hybrid waves (LHWs) are applied to H-mode plasmas with ion cyclotron resonant heating. This has been demonstrated to be due to the formation of helical current filaments flowing along field lines in the scrape-off layer induced by LHW. This leads to the splitting of the outer divertor strike points during LHWs similar to previous observations with resonant magnetic perturbations. The change in the magnetic topology has been qualitatively modeled by considering helical current filaments in a field-line-tracing code.

4.
Meat Sci ; 206: 109344, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37778129

RESUMO

Reduction in muscle glycogen triggered by adverse antemortem handling events alters postmortem energy metabolism and results in a high ultimate pH and dark, firm and dry beef, often referred to as 'dark-cutting'. However, the relationship between atypical dark (AT) beef, postmortem energy metabolism and underlying tissue characteristics remains somewhat unclear. Cattle harvested in the US and Canada representing normal (pH < 5.6), AT dark (pH 5.6-5.8) and dark cutting (DC; pH > 5.8) beef were analyzed for tissue characteristics related to energy metabolism. Results show AT dark beef is more oxidative but similar to normal beef in glycolytic potential and nucleotide abundance. Mitochondria DNA content (P < 0.05, Canada; P < 0.005, US) and oxidative enzymes for DC and AT dark beef were greater (P < 0.01; Canada and US) compared to normal beef. Myoglobin tracked (P < 0.01) with color classification. These findings show both DC and AT beef are inherently more oxidative and raise the possibility that more oxidative muscle may be more prone to develop dark beef.


Assuntos
Músculo Esquelético , Carne Vermelha , Bovinos , Animais , Músculo Esquelético/química , Cor , Mioglobina/análise , Glicogênio/análise , Glicólise , Concentração de Íons de Hidrogênio , Carne Vermelha/análise
5.
Meat Sci ; 185: 108721, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34923395

RESUMO

Variations in color, though a quality frustration, are common across the face of fresh and processed hams. Herein, we measured objective color across the semimembranosus (SM) muscle early postmortem and at 1440 min, then compared these differences against biochemical and metabolic characteristics responsible for pork quality development. Color (L*, a*) differed (P < 0.001) by zone and time but no interaction was evident. Lactate content and pH were highly correlated (R2 = 0.92) at 30 min, but weakened (R2 = 0.161412) by 1440 min. Lactate anaplerosis was not responsible for this lack of relationship. Glycolytic potential also differed across zone (P < 0.001) and time (P < 0.005). Differences in myoglobin expression and abundance, as well as mitochondrial DNA were notable (P < 0.05) across zone. These data suggest inherent differences in SM muscle are key determinants of ham color variation, while postmortem metabolism may play a lesser role in driving this quality attribute.


Assuntos
Músculos Isquiossurais , Carne , Animais , Cor , Glicólise , Concentração de Íons de Hidrogênio , Carne/análise , Músculo Esquelético/metabolismo , Mioglobina/metabolismo , Suínos
7.
Br J Surg ; 79(11): 1184-6, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1467901

RESUMO

A recognized major postoperative complication of hepatic hydatid disease is accumulated hydrops leading to secondary infection in the residual cavity of the excised cyst. This study examined two methods of treating cystic hepatic hydatid disease in 43 children. A group of 22 children were treated by a new method of open drainage, 21 underwent capsulorrhaphy without drainage. There was no mortality or morbidity. The open method was associated with more rapid resolution of hydrops and quicker shrinkage of residual cavities, with efficacy over a median follow-up of 42 months.


Assuntos
Drenagem , Equinococose Hepática/cirurgia , Fígado/cirurgia , Adolescente , Criança , Pré-Escolar , Drenagem/métodos , Feminino , Hospitalização , Humanos , Tempo de Internação , Masculino , Cuidados Pós-Operatórios
8.
Asia Pac J Clin Nutr ; 8(2): 91-5, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24393791

RESUMO

Event-related potentials (ERP) were assessed in 70 school-aged children with a diagnosis of asymptomatic iron deficiency anaemia (IDA), based on low haemoglobin and either low serum ferritin or high free erythrocyte protoporphyrin levels. The IDA subjects were randomized into treatment and placebo groups of 35 cases each, and compared with a normal control group of 30 age- and gender-matched healthy subjects without iron deficiency. Further haematological and ERP assessment was carried out after 3 months, during which time the active group received iron supplementation with 10 mg ferrous sulphate, together with vitamin C, malic acid and folic acid. Pre-treatment, both IDA groups had prolonged P300 latencies in comparison with the non-IDA controls (p<0.01). The proportion of cases with distorted wave appearance was more than twice as high in the IDA groups as in the non-IDA controls, although intergroup differences did not reach statistical significance. After treatment, the active treatment IDA group showed a significant increase in haemoglobin levels and shortening in P300 latencies. After treatment, neither value was statistically different from non-IDA controls. There was a decrease in the number of cases with abnormal waveforms in the active treatment group, compared with an increase in the number within the placebo group (P = 0.002). Testing of ERP shows promise as a non-invasive, sensitive and objective marker for assessing cognitive impairment in children with IDA.

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