Toward an ideal polymer binder design for high-capacity battery anodes.

The dilemma of employing high-capacity battery materials and maintaining the electronic and mechanical integrity of electrodes demands novel designs of binder systems. Here, we developed a binder polymer with multifunctionality to maintain high electronic conductivity, mechanical adhesion, ductility, and electrolyte uptake. These critical properties are achieved by designing polymers with proper functional groups. Through synthesis, spectroscopy, and simulation, electronic conductivity is optimized by tailoring the key electronic state, which is not disturbed by further modifications of side chains. This fundamental allows separated optimization of the mechanical and swelling properties without detrimental effect on electronic property. Remaining electronically conductive, the enhanced polarity of the polymer greatly improves the adhesion, ductility, and more importantly, the electrolyte uptake to the levels of those available only in nonconductive binders before. We also demonstrate directly the performance of the developed conductive binder by achieving full-capacity cycling of silicon particles without using any conductive additive.

A Blueprint for Streamlining Patient Pathways Using a Hybrid Lean Management Approach.

BACKGROUND: Streamlining patient pathways within health care systems is a complex and challenging process. While frontline clinicians often have an abundance of ideas, these rarely translate into real-world change due to nonadoption or early abandonment. OBJECTIVES: The aim of this article is to provide frontline clinicians with a blueprint for developing a business case for a streamlined pathway while guiding the practical implementation of this blueprint. METHODS: The key steps outlined in streamlining a patient pathway are as follows: step 1-identify problems with the patient pathway; step 2-identify the potential to streamline; step 3-forecast the benefits of the streamlined pathway; step 4-gain approvals; step 5-plan the practicalities; step 6-implement and monitor the streamlined pathway; and step 7-monitor the streamlined pathway. Within these steps, Lean management techniques are introduced (including value stream mapping, Pareto charts, Ishikawa diagrams, demand and capacity calculations, role lane mapping) and strengthened by other methods (retrospective audit, systematic review, patient questionnaires, and cost analysis). RESULTS: This roadmap is contextualized using a case study, demonstrating how streamlining pathways can result in statistically significant reductions in referral to treatment time, the number of steps in the pathway, lead time (pathway duration), and handoff (transfer of patients between health care professionals). This can be achieved while increasing patient contact time, improving patient satisfaction, and reducing costs. CONCLUSION: This blueprint demonstrates a comprehensive method for streamlining patient pathways, using Lean management techniques complemented by additional methods. This approach was developed by frontline clinicians and can be replicated by others, translating quality improvement ideas into sustainable change in practice. It enables the design of streamlined pathways that confer significant benefits to patients, health care service providers, and the health economy.

Case Report: Case report: A rare case of middle-ear Rhabdomyosarcoma in a 4-year-old boy.

We present a rare case of a four-year-old boy with a botyroid embryonal rhabdomyosarcoma of the right middle ear. Rhabdomyosarcoma is a soft tissue malignancy which is thought to originate from embryonic mesenchymal cells of striated skeletal muscle.  It is a disease primarily of children and is exceptionally rare in parameningeal regions.  The diagnosis is often delayed and easily misdiagnosed as aural polyp. Therefore, advanced disease is common at the time of diagnosis.  A four-year-old boy presented with a four-month history of recurrent left ear blood and pus discharge, otalgia and fevers. He attended his GP three times and paediatric A&E 13 times where he received antibiotics for presumed otitis media and externa. He was eventually referred to the otolaryngology department and underwent an examination under anaesthesia of ear and excisional biopsy of a suspicious aural polyp.  Staging chest CT and PET scan showed no loco-regional spread or distal metastasis. Magnetic resonance imaging demonstrated absence of invasion into adjacent organs.  Histology confirmed embryonal rhabdomyosarcoma, botryoid subtype.  Subsequent to the initial excision of the polyp, he was started on an ifosfamine, vincristine and actinomycin (IVA) chemotherapy regime in three weekly cycles for nine cycles with concomitant radiotherapy. Two weeks subsequent to his first chemotherapy dose he presented with a House-Brackmann II-III facial nerve palsy but no other middle ear complications. He was started on intravenous antibiotics and dexamethasone. The facial nerve palsy incompletely resolved with treatment.

Electrostatic double-layer interaction between spherical particles inside a rough capillary.

Predictions of electrostatic double-layer interaction forces between two similarly charged spherical colloidal particles inside an infinitely long "rough" capillary are presented. A simple model of a rough cylindrical surface is proposed, which assumes the capillary wall to be a periodic function of axial position. The periodic roughness of the wall is characterized by the wavelength and amplitude of the undulations. The electrostatic double-layer interaction force between two spherical particles located axially inside this rough capillary is determined by solving the nonlinear Poisson-Boltzmann equation employing finite element analysis. The effect of surface roughness of the cylindrical enclosure on the interaction force between two particles is extensively studied on the basis of this model. The simulations are carried out for dimensionless amplitudes (amplitude/particle radii) ranging from 0.05 to 0.15 and scaled wavelengths (wavelength/particle radii) ranging from 0.4 to 4.0. The interaction force between the particles is significantly modified by the proximity of the rough capillary wall. Generally, the interaction force for rough capillaries oscillates around the corresponding interaction force in a smooth capillary depending on the magnitudes of the scaled amplitude and wavelength of the roughness. The influence of roughness on the electrostatic interactions becomes more pronounced when the surface potential of the cylinder wall is different from the sphere surface potentials. When the cylinder and the particle surfaces have large potential differences, the axial force experienced by a particle is dominated by the capillary roughness. There are dramatic oscillations of the force, which alternately becomes repulsive and attractive as the particle moves from the crest to the trough of the rough capillary wall. These results suggest that manipulation of colloidal particles in narrow microchannels may be subject to significant force variations owing to the roughness inherent in microfabricated channels etched on metal films.

Usefulness of cone-beam computed tomography in determining the position of ossicular prostheses: a cadaveric model.

HYPOTHESIS: Cone-beam computed tomography (CT) is proving useful in various operative settings. We hypothesize that it has great potential as an intraoperative assessment tool for ossicular prosthesis positioning. BACKGROUND: Results from prosthetic ossiculoplasty are frequently disappointing. Undetected intraoperative displacement of the prosthesis may be caused, and obscured, by placement of an overlying cartilage graft. METHODS: A cadaveric right temporal bone was prepared with a tympanomeatal flap, and an extended posterior tympanotomy through a cortical mastoidectomy. Each of 3 commercially available prostheses was positioned in 3 different locations: (1) optimal, (2) grossly displaced, and (3) marginally displaced. The intended prosthetic positions were confirmed by endoscopy before and after cone-beam CT image acquisition. The primary outcome measure was the position of the prosthesis in relation to the stapes and tympanic membrane, as assessed by 5 expert reviewers blinded to the study. Secondary outcome measures included optimal dosing for adequate image resolution and radiographic scatter associated with different prosthetic materials. RESULTS: Cone-beam CT accurately demonstrated the position of ossicular reconstruction prostheses with respect to the stapes and tympanic membrane. Prosthesis displacement, whether minimally or marked, was also accurately demonstrated. Interobserver agreement among the 5 reviewers, measured using a Fleiss κ statistic, ranged from 0.4 to 0.8 (fair to substantial agreement depending on type and position of the prosthesis). CONCLUSION: Cone-beam CT is a useful tool for determining the position of ossicular reconstruction prostheses in situ. We suggest it has potential for intraoperative assessment, to check positioning after the prosthesis has been covered with a cartilage graft and tympanomeatal flap.

Electrostatic double layer force between a sphere and a planar substrate in the presence of previously deposited spherical particles.

A finite element model of the electrostatic double layer interaction between an approaching colloidal particle and a small region of a charged planar surface containing four previously deposited particles is presented. The electrostatic interaction force experienced by the approaching particle is obtained by solving the Poisson-Boltzmann equation with appropriate boundary conditions representing this complex geometry. The interaction forces obtained from the detailed three-dimensional finite element simulations suggest that for the many-body scenario addressed here, the electrostatic double layer repulsion experienced by the approaching particle is less than the corresponding sphere-plate interaction due to the presence of the previously deposited particles. The reduction in force is quite significant when the screening length of the electric double layer becomes comparable to the particle radius (kappaa approximately 1). The results also suggest that the commonly used technique of pairwise addition of binary interactions can grossly overestimate the net electrostatic double layer interaction forces in such situations. The simulation methodology presented here can form a basis for investigating the influence of several previously deposited particles on the electrostatic repulsion experienced by a particle during deposition onto a substrate.