Topological insulators display unique properties, such as the quantum spin Hall effect, because time-reversal symmetry allows charges and spins to propagate along the edge or surface of the topological insulator without scattering. However, the direct manipulation of these edge/surface states is difficult because they are significantly outnumbered by bulk carriers. Here, we report experimental evidence for the modulation of these surface states by using a gate voltage to control quantum oscillations in Bi(2)Te(3) nanoribbons. Surface conduction can be significantly enhanced by the gate voltage, with the mobility and Fermi velocity reaching values as high as ~5,800 cm(2) V(-1) s(-1) and ~3.7 × 10(5) m s(-1), respectively, with up to ~51% of the total conductance being due to the surface states. We also report the first observation of h/2e periodic oscillations, suggesting the presence of time-reversed paths with the same relative zero phase at the interference point. The high surface conduction and ability to manipulate the surface states demonstrated here could lead to new applications in nanoelectronics and spintronics.

Purpose To estimate dry eye prevalence in the Beaver Dam Offspring Study (BOSS), including a young adult population, and investigate associated risk factors and impact on health-related quality of life. Design Cohort study. Methods The BOSS (2005–2008) is a study of aging in the adult offspring of the population-based Epidemiology of Hearing Loss Study cohort. Questionnaire data on health history, medication use, risk factors, and quality of life were available for 3275 participants. Dry eye was determined by self-report of frequency of symptoms and the intensity of those symptoms. Associations between dry eye and risk factors were analyzed using logistic regression. Results The prevalence of dry eye in the BOSS was 14.5%, 17.9% of women and 10.5% of men. In a multivariate model, statistically significant associations were found with female sex (Odds Ratio (OR), 1.68; 95% Confidence Interval (CI), 1.33–2.11), current contact lens use (OR, 2.01; 95%CI, 1.53–2.64), allergies (OR, 1.59; 95%CI 1.22–2.08), arthritis (OR, 1.44; 95%CI, 1.12–1.85), thyroid disease (OR, 1.43; 95%CI, 1.02–1.99), antihistamine use (OR, 1.54; 95%CI, 1.18–2.02), and steroid use (OR, 1.54; 95%CI, 1.16–2.06). Dry eye was also associated with lower scores on the Medical Outcomes Short Form-36 (β=−3.9, p<0.0001) as well as on the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) (β= −3.4, p<0.0001) when controlling for age, sex, and comorbid conditions. Conclusions The prevalence of dry eye and its associated risk factors in the BOSS were similar to previous studies. In this study, DES was associated with lower quality of life on a health-related quality of life instrument and the vision-specific NEI-VFQ-25.

OBJECTIVE-To assess the prevalence of tinnitus along with factors potentially associated with having tinnitus. DESIGN-Datawere from the Beaver Dam Offspring Study, an epidemiological cohort study of aging.STUDY SAMPLE-After a personal interview and audiometric examination, participants (n=3267, ages 21-84 years) were classified as having tinnitus if in the past year they reported having tinnitus of at least moderate severity or that caused difficulty in falling asleep.RESULTS-The prevalence of tinnitus was 10.6%. In a multivariable logistic regression model adjusting for age and sex, the following factors were associated with having tinnitus: hearing impairment (Odds Ratio (OR) = 3.20), currently having a loud job (OR = 1.90), history of head injury (OR = 1.84), depressive symptoms (OR = 1.82), history of ear infection (men, OR = 1.75), history of target shooting (OR = 1.56), arthritis (OR = 1.46), and use of NSAID medications (OR = 1.33). For women, ever drinking alcohol in the past year was associated with a decreased risk of having tinnitus (OR = 0.56).CONCLUSIONS-These results suggest that tinnitus is a common symptom in this cohort and may be associated with some modifiable risk factors. KeywordsTinnitus; Demographics/Epidemiology; Hearing Conservation; Aging Tinnitus is the perception of sound in the ears or head unrelated to an external source. It can be a symptom of a variety of auditory disorders, and can be very troublesome in its more severe forms. Its exact causal mechanisms, however, are not well understood.Corresponding author: David M. Nondahl, MS, Department of Ophthalmology and Visual Sciences, University of Wisconsin, 610 Walnut Street, Room 1040, Madison, WI 53726-2397 Fax: (608) 265-2148; Nondahl@episense.wisc.edu . Declaration of InterestThe authors report no declarations of interest. The project described was supported by R01AG021917 from the National Institute on Aging, National Eye Institute, and National Institute on Deafness and Other Communication Disorders. The content is solely the responsibility of the authors and does not necessarily reflect the official views of the National Institute on Aging or the National Institutes of Health. (Nondahl et al, 2002). The EHLS also estimated the 5-year incidence (5.7%; Nondahl et al, 2002) and 10-year incidence of tinnitus (12.7%;Nondahl et al, 2010). Longitudinal studies such as these help to increase understanding of the etiology of the symptom over time. NIH Public AccessData from cross-sectional cohort studies on factors associated with having tinnitus are limited. The baseline EHLS reported that female gender, hearing impairment, cardiovascular disease and history of head injury were positively associated with having tinnitus, while age was inversely associated (Nondahl et al, 2002). Sindhusake and colleagues (2003b), using cross-sectional data from the Blue Mountains Hearing Study, reported that poorer hearing, poorer cochlear function, occupational noise exposure, history of middle ear or sinus infections, severe neck injury ...

clinicaltrials.gov Identifier: NCT01045330.