Comparing the Effects of Self-Generated and Platform-Generated Whole Body Vibration on Vocal Fatigue.

OBJECTIVES: A whole body vibration platform using vertical oscillation has been shown to be efficacious in reducing vocal fatigue in adults. This study aimed to investigate whether this platform-generated whole body vibration was unique in reducing vocal fatigue by comparing it with self-generated whole body vibration. METHODS: Twenty-four female adults (mean age = 23.96 years) were randomly assigned to one of the following three groups: a machine-generated whole body vibration group (N = 8), a self-generated whole body vibration group (N = 8), and a placebo vocal resting group (N = 8). All participants performed a karaoke singing task for at least 95 minutes. Each participant received 10 minutes of platform-generated vibration, self-vibration, or sham localised vibration (placebo group with basically voice rest only), according to their group allocation. Vocal function ability, measured by the highest fundamental frequency produced, and a self-reported vocal fatigue score were evaluated at three time points: baseline (prefatigue), after the singing task (post-fatigue) and post-vibration. RESULTS: The study revealed that machine-generated whole body vibration was significantly better at improving vocal fatigue than self-generated whole body vibration or voice rest. CONCLUSION: The findings support previous research that machine-generated whole body vibration is effective in reducing vocal fatigue. The non-significant results of self-generated whole body vibration in terms of relieving vocal fatigue suggest that inadequate vibration frequency or amplitude together with leg muscle fatigue may have been the main factor of ineffectiveness.

New Insights into the Interphase between the Na Metal Anode and Sulfide Solid-State Electrolytes: A Joint Experimental and Computational Study.

In this work, we investigated the interface between the sodium anode and the sulfide-based solid electrolytes Na3SbS4 (NAS), Na3PS4 (NPS), and Cl-doped NPS (NPSC) in all-solid-state-batteries (ASSBs). Even though these electrolytes have demonstrated high ionic conductivities in the range of 1 mS cm-1 at ambient temperatures, sulfide sold-state electrolytes (SSEs) are known to be unstable with Na metal, though the exact reaction mechanism and kinetics of the reaction remain unclear. We demonstrate that the primary cause of capacity fade and cell failure is a chemical reaction spurred on by electrochemical cycling that takes place at the interface between the Na anode and the SSEs. To investigate the properties of the Na-solid electrolyte interphase (SSEI) and its effect on cell performance, the SSEI was predicted computationally to be composed of Na2S and Na3Sb for NAS and identified experimentally via X-ray photoelectron spectroscopy (XPS). These two compounds give the SSEI mixed ionic- and electronic-conducting properties, which promotes continued SSEI growth, which increases the cell impedance at the expense of cell performance and cycle life. The SSEI for NPS was similarly found to be comprised of Na2S and Na3P, but XPS analysis of Cl-doped NPS (NPSC) showed the presence of an additional compound at the SSEI, NaCl, which was found to mitigate the decomposition of NPS. The methodologies presented in this work can be used to predict and optimize the electrochemical behavior of an all-solid-state cell. Such joint computational and experimental efforts can inform strategies for engineering a stable electrolyte and SSEI to avoid such reactions. Through this work, we call for more emphasis on SSE compatibility with both anodes and cathodes, essential for improving the electrochemical properties, longevity, and practicality of Na-based ASSBs.

Ramoplanin: a lipoglycodepsipeptide antibiotic.

OBJECTIVE: To review the pharmacology, antimicrobial activity, pharmacokinetics, clinical applications, and safety of ramoplanin, a lipoglycodepsipeptide antibiotic. DATA SOURCES: Information was obtained from MEDLINE and BIOSIS databases (1984-August 2004) and Oscient Pharmaceuticals using the key words ramoplanin, A 16686, A 16686A, and MDL 62198. STUDY SELECTION AND DATA EXTRACTION: Available English-based articles and abstracts were reviewed, along with information from Oscient Pharmaceuticals. DATA SYNTHESIS: Ramoplanin exerts its bactericidal activity against gram-positive aerobic and anaerobic bacteria by blocking peptidoglycan synthesis via lipid II. In vitro susceptibility reports have demonstrated efficacy against antibiotic-resistant gram-positive pathogens. Cross-resistance has not been documented with vancomyin and other glycopeptides. Clinical trials are investigating ramoplanin's oral administration for treatment of Clostridium difficile-associated diarrhea. Previous clinical trials had evaluated the suppression of colonization of vancomycin-resistant Enterococcus with ramoplanin. Adverse effects are minimal, and drug-drug interactions have not been documented. CONCLUSIONS: The completion of clinical trials will determine whether ramoplanin has a promising role as a treatment option for diarrhea due to C. difficile.