ABSTRACT
A quantitative nuclear magnetic resonance method(qNMR) was established for determination of the absolute content of febrifugine. Proton nuclear magnetic resonance spectroscopy of febrifugine was obtained in DMSO-d₆ with hydroquinone as the internal standard substance on a Bruker Ascend 600 MHz superconducting nuclear resonance spectrometer at 298 K. The specific parameters were as follows: the observing frequency was 600 MHz,spectra width was 7 211 Hz, pulse width was 9.70 μs, pulse sequence was zg30,scan times was 32 and relaxation time was 2 s. The proton signal peaked at δ 7.71 for febrifugine and δ 6.55 for hydroquinone were selected as the quantification peaks. Linear regression of quantitative peak area ratio of febrifugine-hydroquinone versus their mass ratio yielded a correlation coefficient of 0.999 6 and a regression equation of +0.008 6．The linear range of febrifugine was 2.17-17.07 g·L⁻¹,the precision RSD was 0.78%(=6),the repeatability RSD was 1.2%(=6),and the contents of three batches of febrifugine sample were 94.91%,95.09% and 95.52%,respectively. The content of febrifugine was 96.44% determined by high performance liquid chromatography(HPLC). The relative error of the content of febrigugine determinted by qNMR and HPLC methods was 1.27%. The results showed that the internal standard method of proton nuclear magnetic resonance spectroscopy could be used to determine the absolute content of febrifugine.
Subject(s)
Magnetic Resonance Spectroscopy , Piperidines , Protons , QuinazolinesABSTRACT
@#BACKGROUND:This systematic review aims to investigate the prediction value of diffusion tensor imaging for motor function recovery of ischemic stroke patients. METHODS:Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 9), PubMed, Embase, Clarivate Analytics, Scopus, CINAHL, Chinese Biomedical Literature Database, China National Knowledge Infrastructure and Google Scholar were searched for either motor recovery or corticospinal tract integrity by diffusion tensor imaging in different stroke phase from January 1, 1970, to October 31, 2016. The study design and participants were subjected to metrological analysis. Correlation coefficient (r) was used for evaluating the relationship between fractional anisotropy (FA) and motor function outcome. Correlation coefficient values were extracted from each study, and 95％ confidence intervals (CIs) were calculated by Fisher's z transformation. Meta-analysis was conducted by STATA software. RESULTS:Fifteen studies with a total of 414 patients were included. Meta-analysis showed that FA in the subacute phase had the significant correlation with motor function outcome (ES=0.75, 95％CI 0.62-0.87), which showed moderate quality based on GRADE system. The weight correlation coefficient revealed that an effect size (ES) of FA in acute phase and chronic phase was 0.51 (95％CI 0.33-0.68) and 0.62 (95％CI 0.47-0.77) respectively. CONCLUSION:This meta-analysis reveals that FA in the subacute phase after ischemic stroke is a good predictor for functional motor recovery, which shows moderate quality based on the GRADE system.
ABSTRACT
Objective To evaluate the clinical effects of multiple rewarming interventions in adult hypothermia trauma patients.Methods A systematic search of Cochrane Library,PubMed,EMBASE,Scopus,CINAHL,Chinese Biomedical Literature Database (CBM),Chinese Knowledge Infrastructure (CNKI),VIP and Wan Fang Database was carried out to identify all randomized controlled trials(RCTs) and controlled clinical trials(CCTs) that explored the effects of rewarming interventions in adult hypothermia trauma patients.The quality of the literature was evaluated using JBI 2008 RCT and quasi-experimental study evaluation criteria.Data and network plot were analyzed and drawn by ADDIS 1.16.7 software.Results Totally 6 RCTs and 1 quasi-experimental design were included,involving 10 interventions and 619 patients.There was statistically significant difference in body temperature after rewarming between the warm blankets and the forced-air blankets in all rewarming measures.The results of the top three interventions were carbon-fiber heating blanket(set to 42℃),forced-air blankets,warmed intravenous fluids plus blanket which resulted from the primary outcome indicators.The incidence of chills and cold discomfort decreased with the use of forced-air blankets and chemical heat pad as compared with traditional warm blankets,while the heart rate of the patients who used chemical heating pads and continuous heating of carbon fiber blanket were declined more than those used normal blankets.Conclusion The effects of carbon-fiber heating blanket which set to 42°C was the best method in all rewarming interventions.But this conclusion still requires randomized controlled trials with larger sample size to further verify.