Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Toxicological Emergencies in the Resuscitation Area of a Pediatric Emergency Department: A 12-Month Review.

OBJECTIVE: Few studies of children with toxicological emergencies describe those undergoing acute resuscitation, and most describe exposures to single agents. We describe a 12-month sample of patients evaluated in the resuscitation area of a pediatric emergency department (ED) for a toxicological emergency. METHODS: We conducted a retrospective chart review of patients in a high-volume, academic pediatric ED. We identified patients evaluated in the ED resuscitation area for toxicological exposure and conducted structured chart reviews to collect relevant data. For all variables of interest, we calculated standard descriptive statistics. RESULTS: Of 2999 patients evaluated in the resuscitation area through 12 months (March 2009 to April 2010), we identified 80 (2.7%) whose primary ED diagnosis was toxicological. The mean age was 11.4 years. Eighty-six percent of patients were triaged to the resuscitation area for significantly altered mental status. The most frequent single exposures were ethanol (25%), clonidine (10%), and acetaminophen (5%). At least 1 laboratory test was performed for almost all patients (97%). Interventions performed in the resuscitation area included intravenous access placement (97%), activated charcoal (20%), naloxone (19%), and endotracheal intubation (12%). Eighty-two percent of patients were admitted to the hospital; 37% to the intensive care unit. No patients studied in this sample died and most received only supportive care. CONCLUSIONS: In a high-volume pediatric ED, toxicological emergencies requiring acute resuscitation were rare. Ethanol and clonidine were the most frequent single exposures. Most patients received diagnostic testing and were admitted. Further studies are needed to describe regional differences in pediatric toxicological emergencies

Age-based model for metacarpophalangeal joint proprioception in elderly

Mike D Rinderknecht,1 Olivier Lambercy,1 Vanessa Raible,2 Joachim Liepert,2 Roger Gassert1 1Rehabilitation Engineering Laboratory, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich, Switzerland; 2Department of Neurorehabilitation, Kliniken Schmieder, Allensbach, Germany Abstract: Neurological injuries such as stroke can lead to proprioceptive impairment. For an informed diagnosis, prognosis, and treatment planning, it is essential to be able to distinguish between healthy performance and deficits following the neurological injury. Since there is some evidence that proprioception declines with age and stroke occurs predominantly in the elderly population, it is important to create a healthy reference model in this specific age group. However, most studies investigate age effects by comparing young and elderly subjects and do not provide a model within a target age range. Moreover, despite the functional relevance of the hand in activities of daily living, age-based models of distal proprioception are scarce. Here, we present a proprioception model based on the assessment of the metacarpophalangeal joint angle difference threshold in 30 healthy elderly subjects, aged 55–80 years (median: 63, interquartile range: 58–66), using a robotic tool to apply passive flexion–extension movements to the index finger. A two-alternative forced-choice paradigm combined with an adaptive algorithm to define stimulus magnitude was used. The mixed-effects model analysis revealed that aging has a significant, increasing effect on the difference threshold at the metacarpophalangeal joint, whereas other predictors (eg, tested hand or sex) did not show a significant effect. The adaptive algorithm allowed reaching an average assessment duration <15 minutes, making its clinical applicability realistic. This study provides further evidence for an age-related decline in proprioception at the level of the hand. The established age-based model of proprioception in elderly may serve as a reference model for the proprioceptive performance of stroke patients, or of any other patient group with central or peripheral proprioceptive impairments. Furthermore, it demonstrates the potential of such automated robotic tools as a rapid and quantitative assessment to be used in research and clinical settings. Keywords: aging, difference threshold, hand function, joint position sense, MCP, robotic assessment, presbypropria, somatosensatio

Significance Of The Peri-insular Extracellular-matrix For Islet Isolation From The Pancreas Of Rat, Dog, Pig, And Man

The presence and distribution in the peri-insular region of extracellular matrix, and in particular basement membrane, was investigated in a comparative study comprising pancreata of rat, dog, pig, and man. Basement membrane markers, collagen type-IV and laminin, were determined immunohistochemically. Additional information pertaining to the structural relationships between endocrine and exocrine pancreas, in particular cell-to-cell and cell-to-matrix contacts, was obtained by electron microscopy. In pig, very little peri-insular capsule is present, and the structural integration of the porcine islet in the exocrine pancreas almost exclusively depends on cell-to-cell adhesion. In the canine pancreas, the islets are almost completely encapsulated with very little direct exocrine-to-endocrine cell-to-cell contact. In rat and man, the situation is intermediate with a tendency towards predominance of cell-to-matrix adhesion. The intra-insular adhesion mechanisms depend largely on cell-to-cell adhesion in all four species. The ultrastructural results suggest that collagenase preparations employed in islet isolation procedures should be of high purity as to preserve the protease-sensitive intra-islet cell-to-cell adhesion. Under these conditions, however, the endocrine-to-exocrine cell-to-cell contacts will be conserved also, resulting in an exocrine-tissue contamination of the islets of Langerhans. Consequently, additional steps for the effective removal of exocrine tissue and the purification of islets are required