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: The aim of the current study was to test the impact of dentin powder on the antimicrobial efficacy of bioactive glass S53P4 (BAG).', 'BAG was suspended (preincubated) in saline at 37 degrees C for different time periods with or without human dentin powder, hydroxylapatite, or decalcified dentin. Subsequently, Enterococcus faecalis ATCC 29212 cells were added to these suspensions and bacterial recovery measured with and without the use of gentle sonication. Furthermore, survival of bacteria in test and control suspensions was assessed over time. Supernatants of suspensions were analyzed for their element contents using atomic absorption spectrophotometry. The effects of pH, silica, and osmolarity on E faecalis viability were assessed using specifically prepared solutions.', 'BAG preincubated with dentin powder caused a significant (P < .05) decrease in viability compared to pure BAG suspensions. This was not based on adherence of bacteria to solid particles or agglutination of the cells, because sonication did not increase bacterial yields. Hydroxylapatite and decalcified dentin did not increase BAG killing efficacy. The additive effect of BAG + dentin powder was dose dependent, occurred only with solids in suspension, and increased with suspension time. An augmented dissolution of glass components, especially silicon, was measured in BAG + dentin powder compared to pure BAG suspensions or counterparts containing hydroxylapatite or decalcified dentin. High osmolarity per se did not affect E faecalis viability, whereas high pH and silica levels did.
Answer: The observed phenomenon was related to an increased BAG dissolution triggered by dentin powder, causing elevated local pH and silica levels.
answer:
Does dentin enhance the effectiveness of bioactive glass S53P4 against a strain of Enterococcus faecalis?

question:
Context: Within Australian hospitals, cardiac and respiratory arrests result in a resuscitation attempt unless the patient is documented as not for resuscitation.', 'To examine the consistency of policies and documentation for withholding in-hospital resuscitation across health services.', 'An observational, qualitative review of hospital policy and documentation was conducted in June 2013 in three public and two private sector hospitals in metropolitan Melbourne. Not for resuscitation (NFR) forms were evaluated for physical characteristics, content, authorisation and decision-making. Hospital policies were coded for alerts, definition of futility and burden of treatment and management of discussions and dissent.', 'There was a lack of standardisation, with each site using its own unique NFR form and accompanying site-specific policies. Differences were found in who could authorise the decision, what was included on the form, the role of patients and families, and how discussions were managed and dissent resolved. Futility and burden of treatment were not defined independently. These inconsistencies across sites contribute to a lack of clarity regarding the decision to withhold resuscitation, and have implications for staff employed across multiple hospitals.
Answer: NFR forms should be reviewed and standardised so as to be clear, uniform and consistent with the legislative framework. We propose a two-stage process of documentation. Stage 1 facilitates discussion of patient-specific goals of care and consideration of limitations of treatment. Stage 2 serves to communicate a NFR order. Decisions to withhold resuscitation are inherently complex but could be aided by separating the decision-making process from the communication of the decision, resulting in improved end-of-life care.
answer:
Does comparison of not for resuscitation ( NFR ) form across five Victorian health services?

question:
Context: Walking is usually undertaken at a speed that coincides with the lowest metabolic cost. Aging however, alters the speed-cost relationship, as preferred walking speeds decrease and energy costs increase. It is unclear to what extent this relationship is affected when older women undertake walking as an exercise modality. The aim of this study was to compare the energetic cost of walking at a self-selected exercise pace for a 30 minute period in older and younger women.', "The energetic cost of walking was assessed using the energy equivalent of oxygen consumption measured in 18 young (age 25 to 49 years) and 20 older (age 50 to 79 years) women who were asked to walk at their 'normal' exercise pace on a motorized treadmill for 30 minutes duration.", 'The mass-specific net cost of walking (Cw) was 15% higher and self-selected walking speed was 23% lower in the older women than in the younger group. When speed was held constant, the Cw was 0.30 (J.kg-1.m-1) higher in the older women.
Answer: Preferred exercise pace incurs a higher metabolic cost in older women and needs be taken into consideration when recommending walking as an exercise modality.
answer:
Is walking speed at self-selected exercise pace lower but energy cost higher in older versus younger women?