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With the anticipation for a more connected world through the Internet of Things, there is still a strong demand for miniaturized chemical sensors. Here, we report on a miniaturized resonant chemical sensor based on a Capacitive Micromachined Ultrasonic Transducer (CMUT) with a low operating voltage suitable for portable gas sensor applications. Previously reported CMUT chemical sensors required a DC operating voltage (16∼50 V) higher than the supply voltages of common circuits (e.g., 1.8–5 V). Thus, additional circuitry such as a charge pump circuit often was required as a part of the sensor interface circuits to supply the DC voltage to CMUT. This resulted in additional power consumption and a larger footprint. In this work, the vacuum gap of the CMUT which determines the operating voltage was reduced to 50 nm through the development of a double oxidation process with a high wafer-level yield. We achieved a significantly smaller pull-in voltage (

OBJECTIVES: Previous evidence suggests that vitamin B6 deficiency may have a deleterious impact on aging and the metabolism of polyunsaturated fatty acids (PUFA). However, the relationship of aging with vitamin B6 status and PUFA metabolism is poorly understood; population-based studies to assess the relationship between plasma pyridoxal 5′-phosphate (PLP; an active form of vitamin B6) and PUFA status for older adults are lacking. Thus, we examined the associations between plasma PLP concentration and plasma PUFA concentrations and ratios [eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), EPA + DHA, EPA/AA, and (EPA + DHA)/AA] among US older adults. We further investigated the association of adequate (PLP ≥ 20 nmol/L) versus deficient (PLP

OBJECTIVES: Antiretroviral therapy has increased life expectancy for HIV infected patients; however, this population is developing chronic illnesses associated with aging. Liver disease is a major cause of non-AIDS mortality, characterized by progressive fibrosis. Infection with HIV and with Hepatitis C Virus (HCV) promotes liver fibrogenesis. Tissue inhibitor of metalloproteinase-1 (TIMP1), inhibits fibrosis regression and is profibrogenic. Association between TIMP1 and liver disease progression in an aging population of HIV/HCV co-infected, HIV mono-infected, HCV mono-infected, and healthy groups from the Miami Adult Studies on HIV (MASH) cohort in Miami, Florida, was investigated. METHODS: Serum TIMP1 levels were determined by ELISA. A non-invasive estimate of liver fibrosis, FIB-4 score was calculated. Liver fibrosis was defined as FIB-4: Low 3.25. ANOVA with Tukey's test assessed the mean differences of FIB-4 score and TIMP1 level between groups, TIMP1 levels between 3 FIB-4 categories, and the effect of age on FIB-4 and TIMP1. Linear regression predicted the association of FIB-4 score and TIMP-1 level. RESULTS: Mean age of the cohort was 54.3 ± 8.1 years with no difference between groups. Mean FIB-4 for HIV/HCV co-infected group was the highest among the 4 groups (P