Investigation of current-density modification during magnetic reconnection by analysis of hydrogen-pellet deflection.

A pellet penetrating the inner region of a tokamak discharge, where the safety factor drops below unity, triggers an instability analogous to a sawtooth crash. Because of the simultaneity of the crash and pellet crossing, the latter is an appropriate probe for investigating the current distribution during reconnection. In this Letter, pellet deflection is used to characterize the associated electron distribution function. The perturbation compatible with the observed trajectory requires a negative current layer on the q=1 magnetic surface between 3 and 12 times the equilibrium current density and an expulsion of high energy electrons from the plasma core.

Appendicitis: why so complicated? Analysis of 5755 consecutive appendectomies.

A perceived high rate of complicated (gangrenous or perforated) appendicitis, despite advances in laboratory and radiographic diagnostic modalities, prompted a review of our experience with appendicitis followed by a prospective analysis that examined the time course from presentation to definitive treatment in 218 consecutive patients. In 5755 appendectomies, our overall rate of complicated appendicitis was 32 per cent; higher in males, in the young, and in the elderly; and relatively stable over each year reviewed. Prospectively, we determined that of the various time intervals, the time from the onset of symptoms to first seeking medical attention is the only significant predictor of complicated appendicitis (39.8 vs 16.5 hours for acute appendicitis). On the other hand, the time from surgical evaluation to operative intervention was significantly shorter for complicated appendicitis (3.8 vs 4.7 hours for acute appendicitis). The high rate of complicated appendicitis with its subsequent sequelae of increased morbidity and resource expenditure is primarily the direct result of patient delay in seeking medical attention and not the result of diagnostic dilemma or surgical delay. Public education, specifically targeting those groups at risk, may provide a substantial and significant solution to the complicated appendix.

[Acute primary stage of HIV infection with documented seroconversion]. / Akutes Primärstadium einer HIV-Infektion mit Nachweis einer Serokonversion.

We report a 34-year-old homosexual man who developed a maculopapular, non-itchy exanthema mainly on the trunk in addition to fever up to 39.8 degrees C, general malaise, arthralgias, generalized enlargement of the lymph nodes, watery diarrhoea and weight loss. The patient was in an acute phase of the HIV infection according to standards of WHO and CDC (i.e. acute infection with duration from 3 days to 3 weeks with occasional mononucleosis-like symptoms and positive antibody tests). We documented the seroconversion from HIV-negativity to HIV-positivity 15 days after the onset of the acute illness, concomitant with the resolution of the clinical symptoms. Haematological changes were monitored during the conversion. The infection with HIV-1 was shown by the reduction of T4 helper cells (262/microliters) and the inversion of the CD4:CD8 ratio (< 0.5 during seroconversion). The patient also developed generalized candidiasis owing to the acute immunodeficiency.