In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Ex Input:
Context: The incidence and predictors of spontaneous hepatitis B surface-antigen (HBsAg) seroclearance in patients with chronic hepatitis B virus (HBV) were evaluated.', 'A total of 1427 patients with chronic HBV infection, who were followed between 1994 and 2013, were investigated in this retrospective study. All data were extracted from patient files.', 'Spontaneous HBsAg seroclearance occurred in 84 patients during 8798 person-years of follow-up. The patients were categorized into 3 groups at follow-up based on HBV DNA features as continuously <100 copies/mL (Group A), 0-10,000 copies/mL (Group B), and 0 to >10,000 copies/mL (Group C). Alanine aminotransferase features in the 2 groups were categorized as continuously normal (<40 U/L) and 0 to >40 U/L. Spontaneous HBsAg seroclearance was seen primarily in patients with Group A HBV DNA features, and continuously low HBV DNA values were the main predictor of HBsAg seroclearance (P < 0.001).\Question: Is a persistently low HBV DNA level a predictor of spontaneous HBsAg clearance in patients with chronic hepatitis B?

Ex Output:
These results suggest that a continuously low viral load is the most important factor affecting spontaneous HBsAg seroclearance.


Ex Input:
Context: Classical conditioning of the eyeblink reflex is a simple form of motor learning which depends on the integrity of the cerebellum. Acquisition of conditioned eyeblink responses is markedly reduced in patients with cerebellar disorders. Noninvasive transcranial direct current stimulation (tDCS) has been reported to modify the excitability of the cerebellar cortex.', 'The aim of the study was to assess whether acquisition of conditioned eyeblink responses (CR) is altered by cerebellar tDCS.', 'A standard delay conditioning paradigm with a 540 ms tone as conditioned stimulus (CS) coterminating with a 100 ms air puff as unconditioned stimulus (US) was used in a total of 30 healthy subjects (18 female, 12 male, mean age 23.4 ± 1.9 years). One hundred paired CS-US trials and 30 extinction CS alone trials were given. tDCS (2 mA intensity, ramp like onset) was applied over the right cerebellar hemisphere ipsilaterally to the US during the acquisition phase. Subjects were randomly assigned to three groups (n = 10) using anodal, cathodal or sham stimulation. The investigator as well as the participants was blinded to the stimulation modality.', 'CR acquisition was significantly enhanced by anodal tDCS (mean total CR incidence 73.4 ± 25.2%) and significantly reduced by cathodal stimulation (12.6 ± 17.2%) compared to sham stimulation (43.8 ± 24.1%). During anodal tDCS CR onset occurred significantly earlier, that is mean onset of responses was shifted closer to CS onset.\Question: Is acquisition of conditioned eyeblink responses modulated by cerebellar tDCS?

Ex Output:
Acquisition and timing of conditioned eyeblink responses is modified by cerebellar tDCS in a polarity dependent manner.


Ex Input:
Context: In patients presenting with a breast lesion, when initial core biopsy histology falls into the category of "uncertain malignant potential" (i.e. a B3 lesion), the next line of investigation has traditionally been a surgical biopsy (SBx). Vacuum-assisted biopsy (VAB) may be a viable minimally invasive alternative to SBx for B3 lesions. The primary aims of this study were to establish whether VAB reduces the need for surgical biopsy and determine VAB sensitivity for carcinoma following initial B3 histology.', 'B3 lesion data was collected from 2004 to 2013 retrospectively, from a single institution that utilises both VAB and SBx.', 'A total of 413 lesions were categorised B3 on initial biopsy. Mean age was 61 years (range: 24-91 years). Mean follow up was 52 months (range: 19-60 months). 156 patients (38%) underwent VAB. Only 20% of patients underwent VAB in 2004, with an increase to 95% by 2013. VAB histology revealed twelve carcinomas, all of which progressed to surgical excision. In six cases, a SBx was required following VAB in order to provide further diagnostic information. In one case, carcinoma was missed on VAB.\Question: Is vacuum-assisted biopsy a viable alternative to surgical biopsy in the investigation of breast lesions of uncertain malignant potential?

Ex Output:

The increase in VAB use over time suggests that the procedure is well tolerated. The results demonstrate a VAB sensitivity of 92% for carcinoma diagnosis. In 96% of cases (150 of 156), VAB results were conclusive enough to avoid a subsequent SBx. This data suggests that VAB may be a preferable alternative to surgical biopsy for many B3 lesions.