Initial Decomposition Reactions of Bicyclo-HMX [BCHMX or cis

We investigated the initial chemical reactions of BCHMX [cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole] with the following procedure. First we used density functional theory molecular dynamics simulations (DFT-MD) on the periodic crystal to discover the initial reaction steps. This allowed us to determine the most important reactions through DFT-MD simulations at high temperatures. Then we started with the midpoint of the reaction (unimolecular or bimolecular) from the DFT-MD and carried out higher quality finite cluster DFT calculations to locate the true transition state of the reaction, followed by calculations along the reaction path to determine the initial and final states. We find that for the noncompressed BCHMX the nitro-aci isomerization reaction occurs earlier than the NO2-releasing reaction, while for compressed BCHMX intermolecular hydrogen-transfer and bimolecular NO2-releasing reactions occur earlier than the nitrous acid (HONO)-releasing reaction. At high pressures, the initial reaction involves intermolecular hydrogen transfer rather than intramolecular hydrogen transfer, and the intermolecular hydrogen transfer decreases the reaction barrier for release of NO2 by ∼7 kcal/mol. Thus, the HONO-releasing reaction takes place more easily in compressed BCHMX. We find that this reaction barrier is 10 kcal/mol lower than the unimolecular NO2 release and ∼3 kcal/mol lower than the bimolecular NO2 release. This rationalizes the origin of the higher sensitivity of BCHMX compared to RDX (1,3,5-trinitrohexahydro-1,3,5-triazine) and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine). We suggest changes in BCHMX that might help decrease the sensitivity by avoiding the intermolecular hydrogen-transfer and HONO-releasing reaction

Is the process of delivery of an individually tailored lifestyle intervention associated with improvements in LDL cholesterol and multiple lifestyle behaviours in people with Familial Hypercholesterolemia?

<p>Abstract</p> <p>Background</p> <p>More insight in the association between reach, dose and fidelity of intervention components and effects is needed. In the current study, we aimed to evaluate reach, dose and fidelity of an individually tailored lifestyle intervention in people with Familial Hypercholesterolemia (FH) and the association between intervention dose and changes in LDL-Cholesterol (LDL-C), and multiple lifestyle behaviours at 12-months follow-up.</p> <p>Methods</p> <p>Participants (n = 181) randomly allocated to the intervention group received the PRO-FIT intervention consisting of computer-tailored lifestyle advice (<it>PRO-FIT*advice</it>) and counselling (face-to-face and telephone booster calls) using Motivational Interviewing (MI). According to a process evaluation plan, intervention reach, dose delivered and received, and MI fidelity were assessed using the recruitment database, website/counselling logs and the Motivational Interviewing Treatment Integrity (MITI 3.1.1.) code. Regression analyses were conducted to explore differences between participant and non-participant characteristics, and the association between intervention dose and change in LDL-C, and multiple lifestyle behaviours.</p> <p>Results</p> <p>A 34% (n = 181) representative proportion of the intended intervention group was reached during the recruitment phase; participants did not differ from non-participants (n = 623) on age, gender and LDL-C levels. Of the participants, 95% received a <it>PRO-FIT*advice</it> log on account, of which 49% actually logged on and completed at least one advice module. Nearly all participants received a face-to-face counselling session and on average, 4.2 telephone booster calls were delivered. None of the face-to-face sessions were implemented according to MI guidelines. Overall, weak non-significant positive associations were found between intervention dose and LDL-C and lifestyle behaviours.</p> <p>Conclusions</p> <p>Implementation of the PRO-FIT intervention in practice appears feasible, particularly <it>PRO-FIT*advice</it>, since it can be relative easily implemented with a high dose delivered. However, only less than half of the intervention group received the complete intervention-package as intended. Strategies to let participants optimally engage in using web-based computer-tailored interventions like <it>PRO-FIT*advice</it> are needed. Further, more emphasis should be put on more extensive MI training and monitoring/supervision.</p> <p>Trial registration</p> <p>NTR1899 at ww.trialregister.nl.</p

Relation between perceived health and sick leave in employees with a chronic illness

Introduction: To improve work participation in individuals with a chronic illness, insight into the role of work-related factors in the association between health and sick leave is needed. The aim of this study was to gain insight into the contribution of work limitations, work characteristics, and work adjustments to the association between health and sick leave in employees with a chronic illness. Methods: All employees with a chronic illness, between 15 and 65 years of age (n = 7,748) were selected from The Netherlands Working Conditions Survey. The survey included questions about perceived health, working conditions, and sick leave. Block-wise multivariate linear regression analyses were performed and, in different blocks, limitations at work, work characteristics, and work adjustments were added to the model of perceived health status. Changes in regression coefficient (B) (%) were calculated for the total group and for sub-groups per chronic illness. Results: When work limitations were added to the model, the B between health and sick leave decreased by 18% (5.0 to 4.1). Adding work characteristics did not decrease the association between health and sick leave, but the B between work limitations and sick leave decreased by 14%, (5.3 to 4.5). When work adjustments were added to the model, the Bs between sick leave and work limitations and work characteristics changed from 4.5 to 3.4 for work limitations and from 2.1 to 1.9 for temporary contract and from -0.8 to -1.0 for supervisor support. Conclusions: The association between health and sick leave was explained by limitations at work, work characteristics, and work adjustments. Paying more attention to work limitations, characteristics and adjustments offers opportunities to reduce the negative consequences of chronic illness. © The Author(s) 2010

Work Adjustments in a Representative Sample of Employees with a Chronic Disease in the Netherlands

<p>Purpose The aims of this study are: (1) to describe the prevalence of needed and implemented work adjustments in a representative sample of Dutch employees with a chronic disease; and (2) to assess the effects of needed and implemented work adjustments on sick leave. Methods The prevalence of work adjustments was assessed in employees with a chronic disease, aged between 15 and 65 years (n = 7,687) from the 2007 Netherlands Working Conditions Survey (NWCS). Of these, N = 2,631 employees participated in the Netherlands Working Conditions Cohort Study (NWCCS) measurements in 2008 and 2009. The NWCCS data were used to investigate the effects of work adjustments on sick leave. All data were self-reported. A repeated measures ANOVA was performed to analyse differences in sick leave in 2007, 2008 and 2009 between employees with and without a need for work adjustments, for those who reported an implemented work adjustment and those who did not. Results In 2007, the prevalence of implemented work adjustments among Dutch employees with a chronic disease was 22 %, while 30 % reported the need of a work adjustment. In employees with and without a need for work adjustments in 2007, a work adjustment in 2008 was significantly associated with a decrease in sick leave from 2007 to 2009. Conclusion The need for work adjustments is higher than the implementation of work adjustments. Work adjustments should be considered more often for employees with chronic diseases, because implementation of a work adjustment is associated with a decrease in sick leave.</p>