Toxic Chemical and their Neutralising Agents in Porous Media

The UK Government Decontamination Service advises central Govern- ment on the national capability for the decontamination of buildings, infrastructure, transport and open environment, and be a source of expertise in the event of a chemical, biological, radiological and nuclear (CBRN) incident or major release of HazMat materials. The study group constructed mathematical models to describe the depth to which a toxic chemical may seep into an initially dry porous substrate, and of the neutralisation process between a decontaminant and the imbibed chemical. The group recognised that capillary suction was the dominant process by which the contaminant spreads in the porous substrate. Therefore, in the first instance the absorption of the contaminant was modelled using Darcy’s law. At the next level of complication a diffuse interface model based on Richards’ equation was employed. The results of the two models were found to agree at early times, while at later times we found that the diffuse interface model predicted the more realistic scenario in which the contaminant has seeped deeper into the substrate even in the absence of further contaminant being supplied at the surface. The decontamination process was modelled in two cases; first, where the product of the decontamination reaction was water soluble, and the second where the reaction product formed soluble in the contaminant phase and of similar density. These simple models helped explain some of the key physics involved in the process, and how the decontamination process might be optimised. We found that decontamination was most effective in the first of these two cases. The group then sought to incorporate hydrodynamic effects into the reaction model. In the long wavelength limit, the governing equations reduced to a one-dimensional Stefan model similar to the one considered earlier. More detailed approximations and numerical simulations of this model were beyond the scope of this study group, but provide an entry point for future research in this area

Multiscale analysis of the effect of surface charge pattern on a nanopore’s rectification and selectivity properties: From all-atom model to Poisson-Nernst-Planck

We report a multiscale modeling study for charged cylindrical nanopores using three modeling levels that include (1) an all-atom explicit-water model studied with molecular dynamics, and reduced models with implicit water containing (2) hard-sphere ions studied with the Local Equilibrium Monte Carlo simulation method (computing ionic correlations accurately), and (3) point ions studied with Poisson-Nernst-Planck theory (mean-field approximation). We show that reduced models are able to reproduce device functions (rectification and selectivity) for a wide variety of charge patterns, that is, reduced models are useful in understanding the mesoscale physics of the device (i.e., how the current is produced). We also analyze the relationship of the reduced implicit-water models with the explicit-water model and show that diffusion coefficients in the reduced models can be used as adjustable parameters with which the results of the explicit- and implicit-water models can be related. We find that the values of the diffusion coefficients are sensitive to the net charge of the pore but are relatively transferable to different voltages and charge patterns with the same total charge

Quality of life during the first year after breast cancer resection

Introduction: Quality of life can be determined by a number of factors, including subjective perception of various spheres of health and health-unrelated factors. Purpose: To compare the quality of life of women who had breast cancer one month and one year after mastectomy, and to verify the usefulness of health-related quality of life (HRQoL) scales in early identification of patients having problems in various functional spheres. Materials and methods: The study included the group of 110 mastectomized women. Quality of life of the participants was estimated with EORTC QLQ-C30 and EORTC QLQ-BR23 questionnaires. Results: Global health status (QoL) determined with the aid of the EORTC QLQ-C30 questionnaire turned out to be significantly higher in women surveyed one year after mastectomy than in those examined one month after the surgery (74.23 vs. 58.33, p<0.001). Moreover, the two groups of patients differed significantly in terms of physical, cognitive, social and role functioning scores. Most of the symptoms assessed were resolved within a year after the breast cancer surgery. No significant intergroup differences were revealed with regard to emotional and socioeconomic functioning or future perspective scores. Conclusions: Quality of life of most mastectomized women improves considerably within one year after the surgery. The use of quality of life instruments can be useful in early postoperative identification of patients who score low on functional and symptom scales. Such patients require support and/or psycho-oncological treatment during the early postoperative period. Quality of life of breast cancer patients during the early postoperative period can be a predictor of this parameter in a longer-term perspective

Quality of life and the level of knowledge and utilization of lymphedema prevention principles among mastectomized patients

Introduction: Breast cancer is the most prevalent female malignancy in Poland. Oncological treatment and its adverse effects diminish quality of life of breast cancer patients, which is determined by a number of somatic, psychological and social factors. Purpose: To assess the quality of life and the level of knowledge and utilization of lymphedema prevention principles among women after surgical treatment of breast cancer. Materials and methods: The study included 145 breast cancer patients after radical mastectomy. The respondents were examined with the validated EORTC QLQ-BR23 questionnaire and a custom-designed survey. Results: Examination with the QLQ-BR23 questionnaire revealed that mastectomized women scored low on the body image scale. The most frequently reported ailments were arm and breast symptoms. While the respondents showed high level of knowledge with regards to lymphedema prevention, they poorly adhered to the prophylactic guidelines. The participants were well aware of the risk factors of lymphedema, and most of them declared avoidance of their harmful effects. Conclusions: Quality of life assessment should constitute an integral component of rehabilitation in every breast cancer patient, as mastectomy exerts significant effect on the outcome of perioperative period. Apart from specialist physiotherapy, also education of patients with regards to principles of lymphedema prevention and autotherapy constitutes an important component of complex management of lymphatic insufficiency