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: SIRT3 is an important regulator in cell metabolism, and recent studies have shown that it may be involved in the pharmacological effects of metformin. However, the molecular mechanisms underlying this process are unclear.', 'The effects of SIRT3 on the regulation of oxidative stress and insulin resistance in skeletal muscle were evaluated in vitro. Differentiated L6 skeletal muscle cells were treated with 750 µmol/L palmitic acid to induce insulin resistance. SIRT3 was knocked down and overexpressed in L6 cells. SIRT3, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65, c-Jun N-terminal kinase 1 (JNK1), and superoxide dismutase 2 (SOD2) were evaluated by Western blotting.', 'Over expression of SIRT3 increased glucose uptake and decreased ROS production in L6-IR cells as well as in L6 cells. Knock-down of SIRT3 induced increased production of ROS while decreased glucose uptake in both L6 and L6-IR cells, and these effects were reversed by N-acetyl-L-cysteine (NAC). Metformin increased the expression of SIRT3 (1.5-fold) and SOD2 (2-fold) while down regulating NF-κB p65 (1.5-fold) and JNK1 (1.5-fold). Knockdown of SIRT3 (P < 0.05) reversed the metformin-induced decreases in NF-κB p65 and JNK1 and the metformin-induced increase in SOD2 (P < 0.05).
Answer: Upregulated SIRT3 is involved in the pharmacological mechanism by which metformin promotes glucose uptake. Additionally, SIRT3 may function as an important regulator of oxidative stress and a new alternative approach for targeting insulin resistance-related diseases.
answer:
Does metformin ameliorate insulin resistance in L6 rat skeletal muscle cells through upregulation of SIRT3?


question:
Context: To investigate the early stages in the formation of bony spurs in relation to normal enthesis development.', "Histologic sections of rat Achilles tendons, stained with toluidine blue or Masson's trichrome, were examined in animals ranging from 2 weeks to 1 year of age. Further material prepared for immunohistochemistry was labeled with monoclonal antibodies for laminin and type IV collagen to highlight the presence of small blood vessels at the enthesis. Sections of small spurs from the Achilles tendons of elderly humans were also examined for comparison.", 'As a part of normal development, bone grows into the Achilles tendon as the calcaneus enlarges. Ossification is preceded by vascular invasion, which occurs along rows of enthesis fibrocartilage cells. Small bony spurs develop when ossification at one point on the enthesis outstrips that on either side.
Answer: Bony spurs can develop in the Achilles tendon without the need for preceding microtears or any inflammatory reaction, and they form by endochondral ossification of enthesis fibrocartilage. The increased surface area created at the tendon-bone junction may be an adaptive mechanism to ensure the integrity of the interface in response to increased mechanical loads.
answer:
Does the mechanism of formation of bony spur ( enthesophytes ) in the achilles tendon?


question:
Context: Benefits to crop productivity arising from increasing CO2 fertilization may be offset by detrimental effects of global climate change, such as an increasing frequency of drought. Phosphorus (P) nutrition plays an important role in crop responses to water stress, but how elevated CO2 (eCO2) and P nutrition interact, especially in legumes, is unclear. This study aimed to elucidate whether P supply improves plant drought tolerance under eCO2.', 'A soil-column experiment was conducted in a free air CO2 enrichment (SoilFACE) system. Field pea (Pisum sativum) was grown in a P-deficient vertisol, supplied with 15 mg P kg(-1) (deficient) or 60 mg P kg(-1) (adequate for crop growth) and exposed to ambient CO2 (aCO2; 380-400 ppm) or eCO2 (550-580 ppm). Drought treatments commenced at flowering. Measurements were taken of soil and leaf water content, photosynthesis, stomatal conductance, total soluble sugars and inorganic P content (Pi).', 'Water-use efficiency was greatest under eCO2 when the plants were supplied with adequate P compared with other treatments irrespective of drought treatment. Elevated CO2 decreased stomatal conductance and transpiration rate, and increased the concentration of soluble sugars and relative water contents in leaves. Adequate P supply increased concentrations of soluble sugars and Pi in drought-stressed plants. Adequate P supply but not eCO2 increased root length distribution in deeper soil layers.
Answer: Phosphorus application and eCO2 interactively enhanced periodic drought tolerance in field pea as a result of decreased stomatal conductance, deeper rooting and high Pi availability for carbon assimilation in leaves.
answer:

Do phosphorus application and elevated CO2 enhance drought tolerance in field pea grown in a phosphorus-deficient vertisol?