instruction:
Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
question:
Context: To test whether subsensory vibratory noise applied to the sole of the foot using a novel piezoelectric vibratory insole can significantly improve sensation, enhance balance, and reduce gait variability in elderly people, as well as to determine the optimal level of vibratory noise and whether the therapeutic effect would endure and the user's sensory threshold would remain constant during the course of a day.", 'A randomized, single-blind, crossover study of 3 subsensory noise stimulation levels on 3 days.', 'Balance and gait laboratory.', 'Healthy community-dwelling elderly volunteers (N=12; age, 65-90y) who could feel the maximum insole vibration.', 'A urethane foam insole with the piezoelectric actuators delivering subsensory vibratory noise stimulation to the soles of the feet.', 'Balance, gait, and timed Up and Go (TUG) test.', 'The vibratory insoles significantly improved performance on the TUG test, reduced the area of postural sway, and reduced the temporal variability of walking at both 70% and 85% of the sensory threshold and during the course of a day. Vibratory sensation thresholds remained relatively stable within and across study days.
Answer: This study provides proof of concept that the application of the principle of stochastic resonance to the foot sole sensory system using a new low-voltage piezoelectric technology can improve measures of balance and gait that are associated with falls. Effective vibratory noise amplitudes range from 70% to 85% of the sensory threshold and can be set once daily.
answer:
Does a shoe insole delivering subsensory vibratory noise improve balance and gait in healthy elderly people?


question:
Context: Chronic HIV/HCV co-infection carries increased risk of cirrhosis, hepatocellular carcinoma, and death. Due to anti-inflammatory properties, HMG co-A inhibitors (statins) may be useful adjunctive therapy to reduce liver disease progression.', 'Clinical information was extracted from the Veterans Affairs HIV and HCV Clinical Case Registries (1999 - 2010). HIV-related variables included combination anti-retroviral therapy (cART) era of diagnosis, CD4 cell count, and percent time with undetectable HIV viral load. Metabolic variables included diabetes, low-HDL, and hypertension. Statin use was measured as percent time with active prescription (time-updated throughout the follow-up period). Cox proportional hazards analysis was used to determine risk factors for cirrhosis (ICD-9 or APRI>2) overall and in groups stratified by alanine aminotransferase (ALT) level above and below 40\u200aIU/L.', 'The cohort included 5985\u200aHIV/HCV co-infected veterans. The majority was black race, and the mean age at index date was 45 years. Statin use was significantly protective of cirrhosis for patients with ALT ≤40\u200aIU/L; for every 30% increase in time on statin, there was a 32% decreased risk of developing cirrhosis (HR 0.68, 95% CI 0.47 -0.98). Diabetes and low-HDL were significantly associated with cirrhosis in patients with ALT > 40\u200aIU/L (HR 1.15, p\u200a<\u200a0.04 and HR 1.3, p\u200a<\u200a0.0001).
Answer: Statin drug use is beneficial in mitigating the risk of liver disease progression for HIV/HCV co-infected patients without advanced liver disease. Low-HDL and diabetes in co-infected patients with abnormal ALT have greater risk of cirrhosis development.
answer:
Do statin drugs decrease progression to cirrhosis in HIV/HCV co-infected individuals?


question:
Context: We sought to investigate the utility of phase-contrast diffuse optical tomography (PCDOT) for differentiation of malignant and benign breast masses in humans and to compare PCDOT with conventional diffuse optical tomography (DOT) for analysis of breast masses in humans.', 'Thirty-five breast masses were imaged in 33 patients (mean age, 51 years; range, 22-80) using PCDOT. Images characterizing the tissue refractive index, and absorption and scattering coefficients of breast masses were obtained with a finite element-based reconstruction algorithm. Theses images were then analyzed and compared with the biopsy/pathology results for all the cases examined.', 'Malignant lesions tended to have a decreased refractive index, allowing them to be discriminated from benign lesions in most cases, whereas absorption and scattering images were unable to accurately discriminate benign from malignant lesions. The sensitivity, specificity, false-positive value, and overall accuracy for refractive index imaging were 81.8%, 70.8%, 29.2%, and 74.3%, respectively. The accuracy of refractive index imaging increases with increasing patient age.
Answer: Refractive index is a new parameter for optical imaging that may be helpful in differentiating between malignant and benign masses in the breast.
answer:

Does phase-contrast diffuse optical tomography pilot result in the breast?