RESUMO
The design, development, and successful implementation of pop-up Langmuir probes installed in the water-cooled divertor of W7-X are described. The probes are controlled by drive coils (actuators) installed behind the divertor plates. These drive coils make use of the magnetic field in W7-X to move the probe tips into and out of the plasma. The drive coils were installed in the vacuum vessel after extensively testing the durability of the coils and analyzing the criteria for safe operation. The probe design is carefully tailored for each of the 36 probe tips in order to be suitable for the different magnetic field configurations used in W7-X and ensure that the probes do not present leading edges to the magnetic flux tubes. An electronic bridge circuit is used for measurement to compensate for the effects of signal propagation time on the long cable lengths used. The diagnostic is integrated with the segment control of W7-X for automated operation and control of the diagnostic. The evaluation of the results from the plasma operation is presented after accounting for appropriate sheath expansion for negative bias voltage on the probes.
RESUMO
For the first time, the (d,^{2}He) reaction was successfully used in inverse kinematics to extract the Gamow-Teller transition strength in the ß^{+} direction from an unstable nucleus. The new technique was made possible by the use of an active-target time-projection chamber and a magnetic spectrometer, and opens a path to addressing a range of scientific challenges, including in astrophysics and neutrino physics. In this Letter, the nucleus studied was ^{14}O, and the Gamow-Teller transition strength to ^{14}N was extracted up to an excitation energy of 22 MeV. The data were compared to shell-model and state-of-the-art coupled-cluster calculations. Shell-model calculations reproduce the measured Gamow-Teller strength distribution up to about 15 MeV reasonably well, after the application of a phenomenological quenching factor. In a significant step forward to better understand this quenching, the coupled-cluster calculation reproduces the full strength distribution well without such quenching, owing to the large model space, the inclusion of strong correlations, and the coupling of the weak interaction to two nucleons through two-body currents.
Assuntos
Núcleo Celular , Física , Fenômenos BiomecânicosRESUMO
BACKGROUND: Escherichia coli asparaginase is an active antileukemia agent in the treatment of childhood acute lymphoblastic leukemia. Allergic reactions occurred in 31 of 125 patients (24.8%) treated with weekly high-dose (25,000 IU/m2) intramuscular E. coli asparaginase and necessitated discontinuation of the drug. METHODS: The authors evaluated the toxic effects of Erwinia asparaginase in the 31 children who had allergic reactions to the E. coli preparation. RESULTS: Subsequent allergic reactions to Erwinia asparaginase occurred in 7 of the 31 children (22.6%). In contrast to previous reports with intravenous administration, most allergic reactions to both asparaginase preparations were characterized by mild urticaria that responded to use of diphenhydramine; none of the reactions was life-threatening. CONCLUSIONS: In summary, the authors found Erwinia asparaginase to be an acceptable substitute for E. coli asparaginase for most children who had allergic reactions. Through the use of both E. coli and Erwinia asparaginase, 94% of children could receive their intended asparaginase.
Assuntos
Asparaginase/efeitos adversos , Proteínas de Bactérias/efeitos adversos , Hipersensibilidade a Drogas/etiologia , Escherichia coli/enzimologia , Pectobacterium carotovorum/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Asparaginase/uso terapêutico , Proteínas de Bactérias/uso terapêutico , Criança , Pré-Escolar , Hipersensibilidade a Drogas/epidemiologia , Feminino , Humanos , Incidência , Lactente , MasculinoRESUMO
Advances in cardiac surgery now enable many children with congenital heart disease (CHD) to survive to adulthood. The influence of such advances on the frequency of various lesions among adult patients undergoing cardiac catheterization (CC) has not previously been addressed. This retrospective analysis of 329 adults with CHD undergoing CC at an adult and at a pediatric referral center demonstrates that when compared to 20 years ago, adults with CHD who now undergo CC are more likely to have complex cardiac disease, and more have had prior surgery. In addition, despite more aggressive surgical management, ventricular dysfunction and dysrhythmias are now commonly encountered residua of CHD in adults who require diagnostic CC. Premature coronary artery disease appears uncommon. These changing characteristics of adults with CHD require consideration in the planning of future health care for these patients.