Restoration of exocrine pancreatic function in older children with cystic fibrosis on ivacaftor.

Prior to the use of cystic fibrosis (CF) modulator therapy, exocrine pancreatic insufficiency in CF was thought to be irreversible. Improvement in pancreatic function on ivacaftor has been reported in open label studies in 1-5 year olds. The mechanism by which ivacaftor might improve exocrine pancreatic function is unclear. Although the effect of ivacaftor on pancreatic function may be more significant in younger children, evidence is mounting that there may still be potential for improvement in older children on long term therapy.

Measurements of X- and γ-ray emission probabilities in the ß(-) decay of (233)Pa.

X- and γ-ray emission probabilities from the ß(-) decay of (233)Pa were measured with planar (LEPS) and coaxial Ge detectors. A (233)Pa source was produced after radiochemical separation from a (237)Np sample in which the parent ((237)Np) and daughter ((233)Pa) nuclides were in secular equilibrium. The results are compared with previous measurements and data evaluations.

Reactor decay heat in 239Pu: solving the γ discrepancy in the 4-3000-s cooling period.

The ß feeding probability of (102,104,105,106,107)Tc, 105Mo, and 101Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the γ component of the decay heat for 239Pu in the 4-3000 s range.

IAEA Coordinated Research Project: updated decay data library for actinides.

Recommended nuclear decay data for specific actinides are important in fuel-cycle studies for thermal and fast reactors and inventory studies for safeguards. Therefore, a programme of work was initiated in 2005 to improve the actinide decay data library of the International Atomic Energy Agency through the efforts of a Coordinated Research Project (CRP). The proposed contents of the new database are described, including the agreement to include additional actinides and a significant number of natural decay chain radionuclides. This work is on-going, and is estimated for completion in 2009/10.

Measurements of the half-life of 246Cm and the alpha-decay emission probabilities of 246Cm and 250Cf.

The alpha-decay half-life of Cm246 has been measured to be T(1/2)=4706 (40)yr by means of the alpha-counting of ingrowth activity following the decay of a mass separated source of the Cf250 parent nuclide. The alpha-decay emission probabilities of Cm246 and Cf250 have also been determined with high precision and have been compared with results from previous measurements. A new alpha-decay branch of Cm246 to the 4(+) level of the ground-state band of the Pu242 daughter nucleus has been identified and characterized.

Nuclear decay data: observations and reflections.

Decay data constitute an important feature of nuclear physics that plays a significant role in the various work programmes of members and associates of the International Committee for Radionuclide Metrology (ICRM). At the invitation of the ICRM, a review has been undertaken with the joint aims of emphasising decay-data achievements over the previous 10 years, and highlighting inadequacies that remain to be addressed in the future.

Decay data: review of measurements, evaluations and compilations.

Decay data represent an important means of characterising and quantifying radioactive material, as well as providing an important route to our understanding of the structure of the nucleus. The principle decay parameters are defined in this review, prior to undertaking an applications-based assessment of the most relevant contemporary measurements, evaluations and compilations. Emphasis has been placed on the demands of a series of IAEA Co-ordinated Research Programmes that focus on decay data and gamma-ray standards. Some of the more important decay-data issues are also reviewed with respect to recent measurements that address the anomalies associated with intermediate- and long-lived radionuclides. Short-lived fission products pose significant characterisation problems due to their high degree of instability, although a combination of mass separation and complex detector arrays has resulted in rapid analyses and major advances in our understanding of their nuclear properties and structure. Finally, a select number of decay-data evaluations and compilations are discussed in terms of the powerful manipulation and communication capabilities of PCs, CD-ROMs and the Internet.

The perils of prudence: how conservative risk assessments distort regulation.

An analysis of several agencies' risk assessments reveals that the present conservative approach through several stages of estimates of amounts of regulated substances, the exposure levels, and cancer risks often tends to distort the actual final regulation. Changes in this process are desirable and possible and would reduce overestimation of cancer risk assessments. These possible changes are discussed.

Occult thyroid disease in an elderly hospitalized population.

Measurements of thyroxine (T4), triiodothyronine (T3), thyrotropin (TSH), and T3 talc uptake (T3TU) were performed on 425 hospitalized patients over 60 years of age. Unsuspected thyroid disease was found in 10 patients (2.4%); 9 were hypothyroid and 1 hyperthyroid. Another 11% of the population had abnormal T4 or TSH levels but were not proved to have thyroid disease. Repeat measurements in 10 of 40 patients with low serum T4 concentrations showed a return of the tests to normal. The low T4 levels occurred in patients who were seriously ill and were usually associated with low T3TU values. Low serum T3 concentrations were observed in 32 of the patients. Although we found TSH to be the most useful test in the diagnosis of hypothyroidism, it is a relatively expensive test and is not helpful in screening for hyperthyroidism. The present results suggest that the best single test for screening for occult thyroid disease is a serum T4 measurement. We recommend a T4 test on all hospitalized patients over age 60 years. Serum should be held in the laboratory for measurement of TSH concentration if the T4 result is below 6.5 micrograms/dl. A T3 resin or talc uptake and a serum T3 measurement should be performed to rule out hyperthyroidism if the serum T4 concentration is elevated. This regimen will identify virtually all cases of occult thyroid disease.