Multiscale Modeling of the Effects of Salt and Perfume Raw Materials on the Rheological Properties of Commercial Threadlike Micellar Solutions.

We link micellar structures to their rheological properties for two surfactant body-wash formulations at various concentrations of salts and perfume raw materials (PRMs) using molecular simulations and micellar-scale modeling, as well as traditional surfactant packing arguments. The two body washes, namely, BW-1EO and BW-3EO, are composed of sodium lauryl ethylene glycol ether sulfate (SLEnS, where n is the average number of ethylene glycol repeat units), cocamidopropyl betaine (CAPB), ACCORD (which is a mixture of six PRMs), and NaCl salt. BW-3EO is an SLE3S-based body wash, whereas BW-1EO is an SLE1S-based body wash. Additional PRMs are also added into the body washes. The effects of temperature, salt, and added PRMs on micellar lengths, breakage times, end-cap free energies, and other properties are obtained from fits of the rheological data to predictions of the "Pointer Algorithm" [ Zou , W. ; Larson , R.G. J. Rheol. 2014 , 58 , 1 - 41 ], which is a simulation method based on the Cates model of micellar dynamics. Changes in these micellar properties are interpreted using the Israelachvili surfactant packing argument. From coarse-grained molecular simulations, we infer how salt modifies the micellar properties by changing the packing between the surfactant head groups, with the micellar radius remaining nearly constant. PRMs do so by partitioning to different locations within the micelles according to their octanol/water partition coefficient POW and chemical structures, adjusting the packing of the head and/or tail groups, and by changing the micelle radius, in the case of a large hydrophobic PRM. We find that relatively hydrophilic PRMs with log POW < 2 partition primarily to the head group region and shrink micellar length, decreasing viscosity substantially, whereas more hydrophobic PRMs, with log POW between 2 and 4, mix with the hydrophobic surfactant tails within the micellar core and slightly enhance the viscosity and micelle length, which is consistent with the packing argument. Large and very hydrophobic PRMs, with log POW > 4, are isolated deep inside the micelle, separating from the tails and swelling the radius of the micelle, leading to shorter micelles and much lower viscosities, leading eventually to swollen-droplet micelles.

The development and evaluation of the use of a virtual learning environment (Blackboard 5) to support the learning of pre-qualifying nursing students undertaking a human anatomy and physiology module.

Students commence nurse education with varying levels of understanding of human anatomy and physiology due to a wide range of previous exposure to the topic. All students, however, are required to attain a broad knowledge of this topic prior to qualification. This paper describes the use of a Virtual Learning Environment (VLE), Blackboard 5, and the associated development of appropriate resources aimed at supporting nursing students undertaking a human anatomy and physiology module at Higher Education Level 1. The VLE was used as part of a blended learning approach. The results suggested that the majority of students utilised the VLE throughout the academic year. Opportunities for independent and self-directed learning were available in that students chose when and where to learn. Students generally commented favourably on ease of use and type of resources available. Frequency of use of the VLE, however, did not correlate strongly with the final examination mark achieved. Overall the VLE and the associated available resources appeared useful in supporting student learning and has been adopted for use in subsequent years.

Mechanical Construct Characteristics Predisposing to Non-union After Locked Lateral Plating of Distal Femur Fractures.

OBJECTIVES: To identify discrete construct characteristics related to overall construct rigidity that may be independent predictors of nonunion after lateral locked plate (LLP) fixation of distal femur fractures. DESIGN: Retrospective case-control study. SETTING: Three level-1 urban trauma centers. PATIENTS/PARTICIPANTS: Two hundred and seventy-one supracondylar femoral fractures treated with LLP at 3 affiliated level 1 urban trauma centers between August 2004 and December 2010. METHODS: Nonunion was defined as a secondary procedure for poor healing. Construct variables included: (1) combined plate design and material variable, (2) Plate length, (3) # screws proximal to fracture, (4) total screw density (TSD), (5) proximal screw density (PSD), (6) presence of a screw crossing the main fracture, and (7) rigidity score multivariable analysis was performed using logistic regression to identify independent risk factors for nonunion. INTERVENTION: LLP fixation. MAIN OUTCOME MEASURE: Nonunion. RESULTS: Nonunion rate was 13.3% (n = 36). There was a significant association between plate design/material and nonunion with 41% of stainless constructs and 10% of titanium constructs resulting in a nonunion (P < 0.001). Rigidity scores reached significance (P = 0.001) with constructs resulting in a nonunion having higher scores. No significant univariate differences with respect to number of proximal screws, plate length, total screw density, or proximal screw density were observed between healed fractures and those with nonunion. Results of the multivariate analysis confirmed that the primary significant independent predictor of nonunion was plate design/material (odds ratio, 6.8; 95% CI, 2.9-16.1; P < 0.001). CONCLUSIONS: When treating distal femur fractures with LLP, combined plate design and material variable has a highly significant influence on the risk of nonunion independent of any other construct variable. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Evaluating the use of streaming video to support student learning in a first-year life sciences course for student nurses.

Streaming video was used to support the learning of first year student nurses on a Life Sciences module, as one of many innovations designed to increase the range of resources and support available to students. This paper describes the background to this innovation, the procedures adopted and the results of extensive evaluation. The use of streaming video was evaluated in three applications in the module. A total of 656 students used online directed-learning sessions that incorporated streamed video. Just over half of these students actually viewed the video streams. Their feedback showed that 32% found access easy, 59% enjoyed using the resources, and 25% were very confident that they learned from them. Different types of video were used, and embedded in diverse ways, but the results were consistent across the three applications. They suggest that streamed video can contribute to useful resources to support learning by student nurses but, for a variety of reasons, it may not appeal or be adequately accessible to all students at present.

Virtual interactive practice: utilizing healthcare information systems to contextualize the skills associated with clinical decision making within nurse education.

This paper reports on a Virtual Interactive Practice (VIP) project that has the potential to revolutionise the educational delivery and learning of clinical skills complementing "real" practice. The focus is currently on nurse learning but the principles could equally be applied to multi and inter-professional learning and clinical decision-making. This project represents a new model to enhance clinical skill acquisition and clinical reasoning using a structured competency base. Integral to this is a strong partnership between education and practice utilising "real" live and recorded anonymised patient data from a critical care clinical information system (CIS) within a large district general hospital to structure scenarios fostering problem-based learning. This educational practice interface enables the synthesis of clinical data using virtual technology and sophisticated scenario-based simulation within a skills laboratory. The aim is to enhance the more ad hoc system of learning within conventional practice placements. Early findings suggest that VIP enhances practice providing a safe but challenging learning experience with the benefit of instant performance feedback to students.

Virtual Interactive Practice: a strategy to enhance learning and competence in health care students.

This paper reports the processes and initial outcomes of a pilot study which investigated a week long 'virtual' children's ward experience for nursing students. Providing sufficient and meaningful experiences which enable students to quickly and effectively achieve competence in diverse areas of practice is often frustrated by the realities of available clinical experiences. Our response to this challenge was to more fully exploit and evaluate technologies which can be used to provide these learning experiences. Students experienced 'real time' scenario based work involving SIM-MAN; interactive information technology scenarios, critical incidents, master classes, video conferencing, and observational skill development exercises. Evaluation methodologies included observation of student performance, competence self rating scales; analysis of videotaped performance episodes and other data generated through the learning activities and lived experience accounts of participants. Initial findings indicate (1) statistically significant improvements in student competence measured through self reports; and (2) evidence of improvement gleaned from observed accounts, video analysis and qualitative evaluative comments. The final outcomes, including work with a control group, will be available for Conference.