Given a passage, 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.

Stilbenes are plant secondary metabolites that have shown promising and varied biological activities. Stilbenes are presently actively studied for the exploitation of this primary raw material resource, involving the concept of biorefining. Methods for the rapid discovery of new and known stilbene structures from various plant sources are thus keenly sought.', 'To establish a simple and rapid technique of off-line HPLC with a diode-array detector (DAD) and NMR for the unambiguous structural elucidation of stilbene structures in the root bark of Norway spruce [Picea abies (L.) Karst.].', 'The stilbene containing fraction was extracted from the plant bark with an ethanol:water mixture (95:5, v/v) preceded by defatting of hydrophobic compounds with n-hexane using the accelerated solvent extraction technique. A portion of the ethanol-water soluble extract was hydrolysed with -glucosidase to prepare stilbene aglycones. The extracts were further purified and enriched using a polymeric adsorbent. Stilbene-enriched extracts were directly characterised by off-line HPLC/DAD-NMR in conjunction with HPLC/DAD and HPLC/DAD with electrospray ionisation MS(n).', 'Trans-isorhapontin and trans-astringin were identified as the major, and trans-piceid as a minor, stilbene glucosides of the bark of roots of Picea abies. Not only stilbene glucosides but also the corresponding stilbene aglycones, such as trans-resveratrol, trans-piceatannol and trans-isorhapontigenin, were rapidly identified from the hydrolysed extract. The acquired heteronuclear single-quantum coherence and heteronuclear multiple bond correlation spectra were used to assign the complete carbon NMR chemical shifts of trans-isorhapontin and trans-astringin without the need of acquiring a (13)C-NMR spectrum.
Do rapid chemical characterisation of stilbenes in the root bark of Norway spruce by off-line HPLC/DAD-NMR?

To observe the effects of Sanhuangyinchi decoction (SHYCD) pretreatment on acute hepatic failure (AHF) induced by D-galactosamine and lipopolysaccharide (LPS) in rats and explore the possible mechanisms involving antioxidant stress and cell apoptosis-related protein expression.', 'Forty-eight SD rats were randomized equally into control group, AHF model group, high-, medium- and low-dose SHYCD groups, and Bicyclol group. Five days after administration of the corresponding drugs, the rats were challenged with peritoneal D-galactosamine (700 mg/kg) plus LPS (10 ug/kg) injections to induce AHF acute hepatic failure except for those in the control group. At 48 h after the injections, blood samples were collected from the rats to detect the levels of ALT, AST, TBIL, PT, INR and FIB, and pathological changes and superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the liver were examined; immunohistochemistry and western blotting were used to detect caspase-3 protein expression in the liver.', 'The levels of ALT, AST, TBIL, TP and INR in the 3 SHYCD groups and Bicyclol group significantly decreased (P<0.05) while FIB significantly increased in comparison with those in the model group. SHYCD obviously ameliorated the pathological changes, enhanced SOD activity (P<0.05), and decreased MDA levels (P<0.05) and caspase-3 expression (P<0.05) in the liver tissue. SHYCD at the medium dose produced similar effects to Bicyclol (P>0.05) and showed better effects at the high dose than Bicyclol (P<0.05).
Does [ Sanhuangyinchi decoction pretreatment ameliorate acute hepatic failure in rats by suppressing antioxidant stress and caspase-3 expression ]?

Cannulation of the common bile duct (CBD) is the initial and sometime challenging step in endoscopic retrograde cholangiopancreatography (ERCP) procedure. Endoscopists often use cannulation attempts and cannulation time to grade cannulation difficulty, but a standard system has yet to be established. The objective of this study was to compare cannulation times with numbers of cannulation attempts, as measures of cannulation difficulty.', 'We conducted a prospective study in a tertiary referral center, enrolling 58 patients who were undergoing ERCP for a variety of indications. Cannulation time and the number of cannulation attempts were recorded for each patient. A subset of 14 ERCPs had two observers assessing attempts at cannulation. Cannulation time, number of attempts and inter-observer variability in assessment of attempts were compared and studied.', 'The degree of agreement between two the methods (cannulation times and number of cannulation attempts) was unacceptable. There were considerable discrepancies between attempt tallies from two observers but the mean difference was statistically insignificant.
Is cannulation time a more accurate measure of cannulation difficulty in endoscopic retrograde cholangiopancreatography than the number of attempts?