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Fluorine plays a major role in the nuclear industry where F2(g) and HF(g) are critical to the preparation of UF6 and UF4. These materials are prepared for uranium enrichment to increase the isotopic concentration of 235U. During separation efforts, the isotope 99Tc (a high yield fission product, 6.1% from 235U) is extracted along with uranium and can be converted to binary technetium fluorides (i.e., TcF4, TcF6) during re-enrichment of used uranium material. This provides a route for 99Tc to reenter the reactor environment and affect the nuclear properties of fuel pellets made with reprocessed uranium. The objective of this work is to prepare and revisit the chemistry of uranium and rhenium fluorides related to fundamental, nuclear fuel cycle and nuclear forensic applications. Rhenium is used as surrogate material for technetium provided that they show similar chemical behavior. Challenges in the preparation of a number of rhenium fluoride materials are discussed. This was conducted with the aim to isolate binary rhenium fluorides as surrogate materials for the later work on technetium fluorides, and to compare their structures to other metal fluorides. Several routes for the isolation of UF4 were investigated using wet chemistry and dry fluorination. Using tube furnace and thermal gravimetric analysis, the decomposition of (NH4)4UF8 was studied at various temperatures under argon and for the first time, the decomposition products were characterized by powder XRD and scanning electron microscope. The results showed the successive formation of (NH4)3UF7, (NH4)2UF6 and UF4. These materials showed unique morphology. Uranium isotopic ratios were verified using thermal ionization mass spectrometry and the characterization reveal many problems in the measurements of uranium fluoride materials. This work presents an updated procedure for the preparation of (NH4)2ReF6. The structure, morphology and spectroscopic properties of (NH4)2ReF6 was investigated. The decomposition of (NH4)2ReF6 was also reinvestigated. In an alumina crucible, (NH4)2ReF6 reacted with the crucible and resulted in the formation of mixed ReO2 phases. In a platinum crucible, the decompostion of (NH4)2ReF6 produced only metallic rhenium. An updated procedure for the preparation of the alkali (K+, Rb+, Cs+) [ReF6]2- is presented. These materials are isostructural to their technetium analogue and their structure consists of distorted [ReF6]2-octahedra, a result also supported by Raman spectroscopy. Altogether, this work reports detail description on the synthesis and characterization of rhenium and uranium fluorides, and provides promising chemical, isotopic, and morphological signatures for considerations in nuclear forensics and nonproliferation studies. From this, useful information related to processing and intended use of nuclear material can be extracted for nuclear forensics investigations.

Background Evidence-informed practice is fundamental to the delivery of high quality health care. Delays and gaps in the translation of research into practice can impact negatively on patient care. Previous studies have reported that problems facing health care professionals such as information overload, underdeveloped critical appraisal skills, lack of time and other individual, organisational and system-level contextual factors are barriers to the uptake of evidence. Health services research in this area has been restricted largely to the evaluation of program outcomes. This paper aims to describe the implementation process of an educational initiative for health care professionals working in midwifery, neonatology or obstetrics aimed at disseminating evidence and enhancing evidence-informed clinical care. Methods We designed and implemented an educational initiative called Evidence Rounds for health care professionals working in the women and children’s division of an urban hospital in Ireland. It consisted of three core components: (1) group educational sessions examining evidence on topics chosen by staff (2) a dedicated website and (3) facilitation, enablement and support from a knowledge translation professional. We evaluated user engagement in the educational program by monitoring attendance figures and website analytics. We followed up with staff at 3, 16 and 21-month intervals after the last educational session to find out whether evidence had been implemented. We use Lavis’s organising framework for knowledge transfer and the Template for Intervention Description and Replication (TIDieR) checklist to describe the educational program and document the implementation process. Results Six educational sessions presented by 18 health care professionals took place over a nine month period with 148 attendances of which 85 were unique (individuals who attended at least one session). During the period spanning from one month before, during and one month after the running of the group sessions, 188 unique visitors, 331 visits and 862 page views were recorded on our website. Conclusions Audit and feedback processes can provide quantitative data to track practice outcomes. Achieving sustainable educational programs can be challenging without dedicated resources such as staffing and funding. Electronic supplementary material The online version of this article (10.1186/s12909-019-1489-y) contains supplementary material, which is available to authorized users.

OBJECTIVE: The aim of this study was to compare the efficiency of canine retraction using modified Marcotte and T-loop retraction springs. MATERIALS AND METHODS: Twenty-four subjects with a treatment plan involving bilateral extractions of upper first premolars were included in the study. A split-mouth design was used to randomly allocate opposite quadrants to either modified Marcotte spring (MS) or T-loop spring (TLS) for canine retraction. Cephalometric radiographs and models were used to measure the rate of canine retraction (primary outcome) and compare the angular/rotational changes in the canines and anchorage loss in molars (secondary outcomes) following retraction. Subjective assessment of pain and discomfort was compared using visual analog scale (VAS). Paired and independent t-tests were used to evaluate changes. RESULTS: The mean amount and rate of retraction of the canine were found to be significantly higher for MS (3.56 ± 0.696 mm and 1.188 ± 0.232 mm, respectively) when compared with TLS (2.125 ± 0.472 mm and 0.71 ± 0.157 mm, respectively). Distopalatal rotation of the canine was also significantly lesser for MS (2.42°±1.868°) than TLS (5.65° ±2.84°, P < 0.001). However, the amount of anchorage loss and canine tipping were significantly higher for MS. Statistically significant higher values in the VAS score for TLS indicated greater discomfort. CONCLUSION: MS exhibited increased rate of retraction and rotation control when compared with TLS during sectional canine retraction. Patient comfort was better for MS as evidenced by the VAS scores. However, the amount of tipping and anchorage loss obtained with MS were significantly higher than TLS.

Routine radiographs made in the orthodontic office can often give way to detection and diagnosis of unusual syndromes, signs or foreign bodies. A case report of one such accidental detection of a very unusual foreign body within the nasal cavity of an orthodontic patient has been presented here to emphasize the importance of routine radiographic views, which over and above aiding in Orthodontic diagnosis, can also often detect potentially life threatening problems in the Oro-facial region.

Lecithin/sphingomyelin (L/S) ratios were measured in 81 amniotic fluid specimens obtained from 41 patients with “stressed pregnancies” as evidenced by chronically low (< 2 S.D.) 24 hour urinary estriol excretion. Fourteen of the patients studied also had a positive oxytocin challenge test. The results suggest that, on the average, fetal pulmonary maturity as evaluated by L/S ratios is not accelerated in “stressed pregnancies.”

SUMMARY.— When a weal evoked as a cutaneous allergic response has disappeared, that area of skin, although appearing normal, shows factitious wealing: this tendency persists for 72–96 hr. The phenomenon is present after weals caused by positive intradermal prick tests from various substances, after weals from certain insect bites, and on the site of fading lesions of acute urticaria. Weals caused by intradermal histamine are not followed by this factitious wealing, nor is it present on skin which has been the site of a weal in chronic urticaria.