320 research outputs found

    Hearing-Related Health Among Adult American Indians From a Pacific Northwest Tribe

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    INTRODUCTION: Hearing loss and tinnitus are common in most populations, although few data have addressed hearing-related health among tribal members and the need for public health interventions. METHODS: This cross-sectional study examined prevalence and risk factors for hearing loss and tinnitus among 217 adults in a Pacific Northwest tribe. Frequency measures were conducted for difficulty hearing certain sounds and hearing aid use. In 2006, risk factors were examined for two outcomes-hearing loss and tinnitus-with analysis conducted in the same year. RESULTS: Although self-reported hearing loss was more common in men (24%) than women (13%), a larger percentage of women compared with men reported difficulty hearing certain sounds. Only 8% of study participants reported hearing aid use. After age adjustment, significant noise exposure was associated with hearing loss (OR=8.30, 95% CI=1.84, 37.52). The overall prevalence of tinnitus was 33% (similar in men and women). After adjusting for age, the odds of tinnitus in individuals with more than four ear infections was 4.77 (95% CI=1.89, 12.02) times the odds in those who never had an ear infection. Tinnitus was also associated with significant noise exposure (OR=2.24, 95% CI=1.28, 6.73) even after age adjustment. CONCLUSIONS: Increasing age and significant noise exposure were associated with hearing loss in this tribe. Tinnitus was associated with significant noise exposure and history of otitis media, even after age adjustment. Public health efforts are needed to improve hearing-related health in this tribe through messages about noise exposure and use of hearing protection

    Optoelectronic analysis of multijunction wire array solar cells

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    Wire arrays have demonstrated promising photovoltaic performance as single junction solar cells and are well suited to defect mitigation in heteroepitaxy. These attributes can combine in tandem wire array solar cells, potentially leading to high efficiencies. Here, we demonstrate initial growths of GaAs on Si_(0.9)Ge_(0.1) structures and investigate III-V on Si_(1-x)Ge_x device design with an analytical model and optoelectronic simulations. We consider Si_(0.1)Ge_(0.9) wires coated with a GaAs_(0.9)P_(0.1) shell in three different geometries: conformal, hemispherical, and spherical. The analytical model indicates that efficiencies approaching 34% are achievable with high quality materials. Full field electromagnetic simulations serve to elucidate the optical loss mechanisms and demonstrate light guiding into the wire core. Simulated current-voltage curves under solar illumination reveal the impact of a varying GaAs_(0.9)P_(0.1) minority carrier lifetime. Finally, defective regions at the hetero-interface are shown to have a negligible effect on device performance if highly doped so as to serve as a back surface field. Overall, the growths and the model demonstrate the feasibility of the proposed geometries and can be used to guide tandem wire array solar cell designs

    An intercomparison of measurement systems for vapor and particulate phase concentrations of formic and acetic acids

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    During June 1986, eight systems for measuring vapor phase and four for measuring particulate phase concentrations of formic acid (HCOOH) and acetic acid (CH_3COOH) were intercompared in central Virginia. HCOOH and CH_3COOH vapors were sampled by condensate, mist, Chromosorb 103 GC resin, NaOH-coated annular denuders, NaOH impregnated quartz filters, K_2CO_3 and Na_2CO_3 impregnated cellulose filters, and Nylasorb membranes. Atmospheric aerosol was collected on Teflon and Nuclepore filters using both hi-vol and lo-vol systems to measure particulate phase concentrations. Samples were collected during 31 discrete day and night intervals of 0.5–2 hour duration over a 4-day period. Performance of the mist chamber and K_2CO_3 impregnated filter techniques were also evaluated using zero air and ambient air spiked with HCOOH_g, CH_3COOH_g, and formaldehyde (CH_2O_g) from permeation sources. Results of this intercomparison show significant systematic and episodic artifacts among many currently deployed measurement systems for HCOOH_g and CH_3COOH_g. The spiking experiments revealed no significant interferences for the mist chamber technique and results generated by the mist chamber and denuder techniques were statistically indistinguishable. The condensate technique showed general agreement with the mist chamber and denuder methods, but episodic bias between these systems was inferred from large and significant differences observed during the first day of sampling. Nylasorb membranes are unacceptable for collecting carboxylic acid vapors as they did not retain HCOOH_g and CH_3COOH_g quantitatively. Strong base impregnated filter and GC resin sampling techniques are prone to large positive interferences apparently resulting, in part, from reactions involving CH_2O_g to generate HCOOH and CH_3COOH subsequent to collection. Significant bias presumably associated with differences in postcollection handling was observed for particulate phase measurements by participating groups. Analytical bias did not contribute significantly to differences in vapor and particulate phase measurements

    Microbial Pathogen-Induced Necrotic Cell Death Mediated by the Inflammasome Components CIAS1/Cryopyrin/NLRP3 and ASC

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    Cryopyrin (CIAS1, NLRP3) and ASC are components of the inflammasome, a multiprotein complex required for caspase-1 activation and cytokine IL-1βproduction. CIAS1 mutations underlie autoinflammation characterized by excessive IL-1β secretion. Disease-associated cryopyrin also causes a program of necrosis-like cell death in macrophages, the mechanistic details of which are unknown. We find that patient monocytes carrying disease-associated CIAS1 mutations exhibit excessive necrosis-like death by a process dependent on ASC and cathepsin B, resulting in spillage of the proinflammatory mediator HMGB1. Shigella flexneri infection also causes cryopyrin-dependent macrophage necrosis with features similar to the death caused by mutant CIAS1. This necrotic death is independent of caspase-1 and IL-1β, and thus independent of the inflammasome. Furthermore, necrosis of primary macrophages requires the presence of Shigella virulence genes. While similar proteins mediate pathogen-induced cell death in plants, this report identifies cryopyrin as an important host regulator of programmed pathogen-induced necrosis in animals, a process we term pyronecrosis

    A Randomized Phase II Trial of Epigenetic Priming with Guadecitabine and Carboplatin in Platinum-resistant, Recurrent Ovarian Cancer.

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    PURPOSE: Platinum resistance in ovarian cancer is associated with epigenetic modifications. Hypomethylating agents (HMA) have been studied as carboplatin resensitizing agents in ovarian cancer. This randomized phase II trial compared guadecitabine, a second-generation HMA, and carboplatin (G+C) against second-line chemotherapy in women with measurable or detectable platinum-resistant ovarian cancer. PATIENTS AND METHODS: Patients received either G+C (guadecitabine 30 mg/m2 s.c. once-daily for 5 days and carboplatin) or treatment of choice (TC; topotecan, pegylated liposomal doxorubicin, paclitaxel, or gemcitabine) in 28-day cycles until progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS); secondary endpoints were RECIST v1.1 and CA-125 response rate, 6-month PFS, and overall survival (OS). RESULTS: Of 100 patients treated, 51 received G+C and 49 received TC, of which 27 crossed over to G+C. The study did not meet its primary endpoint as the median PFS was not statistically different between arms (16.3 weeks vs. 9.1 weeks in the G+C and TC groups, respectively; P = 0.07). However, the 6-month PFS rate was significantly higher in the G+C group (37% vs. 11% in TC group; P = 0.003). The incidence of grade 3 or higher toxicity was similar in G+C and TC groups (51% and 49%, respectively), with neutropenia and leukopenia being more frequent in the G+C group. CONCLUSIONS: Although this trial did not show superiority for PFS of G+C versus TC, the 6-month PFS increased in G+C treated patients. Further refinement of this strategy should focus on identification of predictive markers for patient selection
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