Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Input: Consider Input: Vaginal microbicides for the prevention of HIV transmission may be an important option for protecting women from infection. Incorporation of dapivirine, a lead candidate nonnucleoside reverse transcriptase inhibitor, into intravaginal rings (IVRs) for sustained mucosal delivery may increase microbicide product adherence and efficacy compared with conventional vaginal formulations. Twenty-four healthy HIV-negative women 18-35 years of age were randomly assigned (1:1:1) to dapivirine matrix IVR, dapivirine reservoir IVR, or placebo IVR. Dapivirine concentrations were measured in plasma and vaginal fluid samples collected at sequential time points over the 33-day study period (28 days of IVR use, 5 days of follow-up). Safety was assessed by pelvic/colposcopic examinations, clinical laboratory tests, and adverse events. Both IVR types were safe and well tolerated with similar adverse events observed in the placebo and dapivirine groups. Dapivirine from both IVR types was successfully distributed throughout the lower genital tract at concentrations over 4 logs greater than the EC50 against wild-type HIV-1 (LAI) in MT4 cells. Maximum concentration (Cmax) and area under the concentration-time curve (AUC) values were significantly higher with the matrix than reservoir IVR. Mean plasma concentrations of dapivirine were <2 ng/mL. These findings suggest that IVR delivery of microbicides is a viable option meriting further study.

Output: Which infection can be prevented with Dapivirine?


Input: Consider Input: Chronic myeloid leukemia (CML) is a progressive and often fatal myeloproliferative neoplasm. The hallmark of CML is an acquired chromosomal translocation known as the Philadelphia chromosome (Ph), which results in the synthesis of the breakpoint cluster region-Abelson murine leukemia (BCR-ABL) fusion oncoprotein, a constitutively active tyrosine kinase. The introduction of imatinib, a tyrosine kinase inhibitor (TKI) that is specific for BCR-ABL, was a major breakthrough in CML therapy. Although most patients respond to first-line imatinib therapy, some experience loss of response (resistance) or require treatment discontinuation because of toxicity (intolerance). For patients with CML, failure on standard-dose imatinib therapy (400 mg daily), imatinib dose escalation (600-800 mg daily) is a second-line option. However, high-dose imatinib is not an appropriate approach for patients who experience drug toxicity, and there remain questions over the durability of responses achieved with this strategy. Alternative second-line options include the TKIs dasatinib and nilotinib. A substantial amount of long-term data for these agents is available. Although both are potent and specific BCR-ABL TKIs, dasatinib and nilotinib exhibit unique pharmacologic profiles and response patterns relative to different patient characteristics, such as disease stage and BCR-ABL mutation status. To optimize therapeutic benefit, clinicians should select treatment based on each patient's historic response, adverse-event tolerance, and risk factors.

Output: What tyrosine kinase, involved in a Philadelphia- chromosome positive chronic myelogenous leukemia, is the target of Imatinib (Gleevec)?


Input: Consider Input: Witches' Flight (Spanish: Vuelo de Brujas; also known as Witches in Flight or Witches in the Air), is an oil on canvas painting completed in 1798 by the Spanish painter Francisco Goya.


Output: What is the surface of Witches' Flight made of?