Assessment of personal airborne exposures and surface contamination from x-ray vaporization of beryllium targets at the National Ignition Facility.

This article presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 µg/100 cm2 and 27 results were above the analytical reporting limit of 0.01 µg/100 cm2, for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present in workers' breathing zones. All the data thus far have shown that beryllium has been effectively managed to prevent exposures to workers during routine and non-routine work.

A Randomized Trial of Time-Limited Antiretroviral Therapy in Acute/Early HIV Infection.

BACKGROUND: It has been proposed that initiation of antiretroviral treatment (ART) very soon after establishment of HIV infection may be beneficial by improving host control of HIV replication and delaying disease progression. METHODS: People with documented HIV infection of less than 12 months' duration in Baltimore MD and seven Canadian sites were randomized to either a) observation and deferred ART, or b) immediate treatment with ART for 12 months. All subjects not receiving ART were followed quarterly and permanent ART was initiated according to contemporaneous treatment guidelines. The endpoint of the trial was total ART-free time from study entry until initiation of permanent ART. RESULTS: One hundred thirteen people were randomized, 56 to the observation arm and 57 to the immediate treatment arm. Twenty-three had acute (<2 months) infection and 90 early (2-12 months) infection. Of those randomized to the immediate treatment arm, 37 completed 12 months of ART according to protocol, 9 declined to stop ART after 12 months, and 11 were nonadherent to the protocol or lost to follow-up. Comparing those in the observation arm to either those who completed 12 months of ART or all 56 who were randomized to immediate ART, there was no significant difference between the arms in treatment-free interval after study entry, which was about 18 months in both arms. CONCLUSIONS: This study did not find a benefit from administration of a brief, time-limited (12-month) course of ART in acute or early HIV infection. TRIAL REGISTRATION: ClinicalTrials.gov NCT00106171.

A narrative review of the empirical evidence on public attitudes on brain death and vital organ transplantation: the need for better data to inform policy.

Vital organ transplantation is premised on 'the dead donor rule': donors must be declared dead according to medical and legal criteria prior to donation. However, it is controversial whether individuals diagnosed as 'brain dead' are really dead in accordance with the established biological conception of death-the irreversible cessation of the functioning of the organism as a whole. A basic understanding of brain death is also relevant for giving valid, informed consent to serve as an organ donor. There is therefore a need for reliable empirical data on public understanding of brain death and vital organ transplantation. We conducted a review of the empirical literature that identified 43 articles with approximately 18,603 study participants. These data demonstrate that participants generally do not understand three key issues: (1) uncontested biological facts about brain death, (2) the legal status of brain death and (3) that organs are procured from brain dead patients while their hearts are still beating and before their removal from ventilators. These data suggest that, despite scholarly claims of widespread public support for organ donation from brain dead patients, the existing data on public attitudes regarding brain death and organ transplantation reflect substantial public confusion. Our review raises questions about the validity of consent for vital organ transplantation and suggests that existing data are of little assistance in developing policy proposals for organ transplantation from brain dead patients. New approaches to rigorous empirical research with educational components and evaluations of understanding are urgently needed.