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This study aims at estimating the human walking speed using wearable accelerometers by proposing a novel virtual inverted pendulum model. This model not only keeps the important characteristics of both the biped rolling-foot and the inverted pendulum model, but also makes the speed estimation feasible using human body acceleration. Rather than using statistical methods, the proposed kinematic walking model enables calibration of the parameters during walking using only one tri-axial accelerometer on the waist that collects the user's body acceleration. In addition, this model also includes the effect of rotation of the waist within a walking cycle, which improves the estimation accuracy. Experimental results for a group of humans show a 0.58% absolute error mean and 0.72% error deviation, which is far better than the results of other known studies with accelerometers mounted on the upper body. [ABSTRACT FROM PUBLISHER]

Amphiphilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethyleneoxide) copolymers, also known as poloxamers, have broad biomembraneactivities. To illustrate the nature of these activities, 1H Overhauser dynamic nuclear polarization NMR spectroscopy was employedto sensitively detect polymer–lipid membrane interactions throughthe modulation of local hydration dynamics in lipid membranes. Ourstudy shows P188, the most hydrophilic poloxamer that is a known membranesealant, weakly adsorbs on the membrane surface, yet effectively retardsmembrane hydration dynamics. Contrarily, P181, the most hydrophobicpoloxamer that is a known membrane permeabilizer, initially embedsat lipid headgroups and enhances intrabilayer water diffusivity. Unprecedentedresolution for differentiating weak surface adsorption versus translocationof polymers to membranes is obtained by probing local water diffusivityin lipid bilayer systems. Our results illustrate that the relativehydrophilic/hydrophobic ratio of the polymer dictates its functions.These findings gleaned from local hydration dynamics are well supportedby a thermodynamics study presented in the accompanying paper (Wang,J.-Y.; Marks, J. M.; Lee, K. Y. C. Biomacromolecules, 2012, DOI: 10.1021/bm300847x). [ABSTRACT FROM AUTHOR]

Tin(II) compounds are versatile materials with applications across fields such as catalysis, diagnostic imaging, and therapeutic drugs. However, oxidative stabilization of Sn(II) has remained an unresolved challenge as its reactivity with water and dioxygen results in loss of functionality, limiting technological advancement. Approaches to slow Sn(II) oxidation with chelating ligands or sacrificial electron donors have yielded only moderate improvements. We demonstrate here that the addition of nitrate to pyrophosphate-chelated Sn(II) (aq) suppresses Sn(II) oxidation in water across a broad pH range. Evidence of hydroxyl radical concentration reduction and detection of a radical nitrogen species that only forms in the presence of chelated Sn(II) point to a radical-based reaction mechanism. While this chemistry can be broadly applied, we present that this approach maintains Sn(II)'s antibacterial and anti-inflammatory efficacies as an example of sustained oral chemotherapeutic functionality.

We report a rare case of cisplatin-induced acute hyponatremia leading to a seizure and coma. A 66-year-old woman with breast cancer received adjuvant chemotherapy with docetaxel and cisplatin. She had no nausea, vomiting, or diarrhea during or after chemotherapy administration. She had an acute onset of a generalized seizure and coma on the fourth day after chemotherapy. On arrival in the emergency department, she was unconscious with a Glasgow Coma Score of 6 (eyes 1, verbal 1, motor 4). Computed tomography of the brain did not show any lesions. She had no underlying diseases except breast cancer. The laboratory studies showed severe hyponatremia (Na 113 mmol/L) with low plasma osmolality, and elevation of both urinary sodium and urinary osmolality. In addition, polyuria (about 4 L/day) was also noted. Her consciousness level gradually improved the next day with a rise in serum sodium after 3% NaCl infusion. She recovered fully with no sequelae. Assessment using the Naranjo probability scale suggested that cisplatin was the probable cause for the adverse event. The mechanism of hyponatremia induced by cisplatin in our case was thought to be renal salt wasting syndrome (RSWS). In conclusion, cisplatin-induced acute hyponatremia leading to seizures and coma is seen rarely. When RSWS is suspected, hypertonic saline should be administered.

Branching out: The mobility of linear polymers changes upon branching, which has a pronounced effect on processability and drawability. Regularly branched model polyolefins were studied by advanced solid-state NMR spectroscopy, and twist defects around the branches in the crystalline regions are identified. For lower branch content, the twisting motions are decoupled; for higher content, collective motion is found (see picture).