Mitigation of Silicon Contamination in Fuel Cell Gasket Materials through Silica Surface Treatment.

Gaskets and seals are essential components in the operation of proton exchange membrane (PEM) fuel cells and are required for keeping hydrogen and air/oxygen within their individual compartments. The durability of these gaskets and seals is necessary, as it influences not only the lifespan but also the electrochemical efficiency of the PEM fuel cell. In this study, the cause of silicon leaching from silicone gaskets under simulated fuel cell conditions was investigated. Additionally, to reduce silicon leaching, the silica surface was treated with methyltrimethoxysilane, vinyltriethoxysilane, and (3,3,3-trifluoropropyl)trimethoxysilane. Changes in the silica surface chemistry were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, elemental analysis, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Inductively coupled plasma-optical emission spectroscopy analysis revealed that surface-treated silica was highly effective in reducing silicon leaching.

Pediatric Cannabis Single-Substance Exposures Reported to the Michigan Poison Center From 2008-2019 After Medical Marijuana Legalization.

BACKGROUND: Legalization of medical and recreational cannabis is a major contributor to pediatric cannabis exposures. The trends and magnitude of pediatric cannabis exposures in Michigan after medical cannabis legalization in 2008 have not been assessed. OBJECTIVE: To describe the temporal trends of pediatric cannabis exposures reported to the Michigan Poison Center (MiPC) after medical cannabis was legalized in 2008 and 1 year after legalization of recreational cannabis in 2018. METHODS: Retrospective electronic chart review of pediatric (<18 years old) single-substance cannabis exposures reported to the MiPC from January 1, 2008 to December 31, 2019. Routes of cannabis exposure were reported as ingestion, inhalation, and unknown. Types of ingested cannabis products were also documented. RESULTS: Between 2008 and 2019, 426 pediatric cannabis single exposures were reported. The median patient age was 6.0 years (interquartile range 2-15 years). Age distribution was bimodal. A total of 327 (76.8%) exposures were from cannabis ingestion, 79 (18.5%) from inhalation, 2 (0.5%) from both ingestion and inhalation, and 18 (4.2%) from unknown route. The doubling time for number of cases was 2.1 years, and the total number of annual reported cases increased after 2016. Teenagers (13-17 years) had the highest number of inhalational exposures, whereas young children (0-5 years) had the highest number of ingestions. CONCLUSION: Single-substance pediatric cannabis exposures reported to the Michigan Poison Center increased after medical cannabis was legalized in 2008 through recreational legalization in 2018.

Long-term clinical outcomes of the tension-free vaginal tape procedure for the treatment of stress urinary incontinence in elderly women over 65.

PURPOSE: The aim of this study was to assess the long-term clinical outcomes of the tension-free vaginal tape (TVT) procedure for stress urinary incontinence (SUI) in elderly women and to identify the factors influencing failure in these cases. MATERIALS AND METHODS: Women with SUI who underwent a TVT procedure were studied. "Cure" was defined as no urine leakage at all in any circumstances and "improvement" was defined as some urine leakage but a score of over 4 points out of 5 in a satisfaction inquiry. Patients were divided into two groups (middle-aged, <65 years and elderly, ≥65 years) for comparison of clinical outcomes. In the elderly group, patients were subdivided into two groups (cure and no cure groups) and were compared to identify the factors influencing failure. RESULTS: A total of 136 women (middle-aged group, 106; elderly group, 30) were enrolled in the study. The mean ages of the patients in the 2 groups were 53.5±5.9 and 72.0±5.0 years and the mean follow-up times were 50.5±9.4 and 48.8±9.1 months, respectively. The cure and improvement rates in the middle-aged and elderly groups were 80.2% vs. 66.7% and 4.7% vs. 3.3%, respectively (p>0.05). The satisfaction scores in the middle-aged and elderly groups were 3.8±1.1 vs. 3.3±1.5 points (p>0.05). In the elderly group, the body mass index of the cure and no cure groups were 24.6±3.3 kg/m(2) and 26.6±1.0 kg/m², and body mass index was the only factor that differed significantly between the two subgroups (p=0.028). CONCLUSIONS: Our long-term results suggest that TVT is an effective treatment even in elderly women. However, elderly women who are obese should be counseled carefully about the success rate.