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Objective To establish a rapid prediction method of the antioxidant activity in aqueous extract solutions of Melastoma dodecandrum based on ultraviolet spectroscopy and partial least squares regression algorithm. Methods The DPPH free radical scavenging effect was used to characterize the antioxidant activity of aqueous extract solutions of Melastoma dodecandrum. The ultraviolet spectra of 190-600 nm were collected. The partial least squares regression model of antioxidant activity was established after optimizing the wavelength range and preprocessing method. The software was devised using Visual Basic as the integrated development environment to provide a convenient tool for the rapid determination of antioxidant activity. Results The optimal partial least squares regression model was established based on 200-290 nm as wavelength range and unit variance scaling as preprocessing method. The correlation coefficient of calibration, root mean square error of estimation, root mean square error of cross-validation was 0.887, 2.20% and 2.17%, respectively. The correlation coefficient of validation, root mean square error of prediction was 0.868, 2.08%. The average predicted recovery was 100.1±2.3%. With the predictive function in the software, the antioxidant activity of aqueous extract solution of Melastoma dodecandrum can be calculated automatically within 2 s after collecting the ultraviolet spectra. Conclusions This study provides a rapid method for the prediction of antioxidant activity in aqueous extract solutions of Melastoma dodecandrum.
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OBJECTIVE To optimize the pr eparation technology of the baicalin lipid nano foam aerosol （BC-LN-FA）. METHODS Baicalin lipid nanoparticle （BC-LN）and BC-LN-FA were prepared by the thin film dispersion method and homogeneous emulsification method ，respectively，using baicalin （BC） as the model drug. The preparation technology was optimized by Box-Behnken design-response surface methodology using particle size and encapsulation efficiency （EE）as indexes ，with dosage ， emulsifier dosage ，co-emulsifier dosage and homogenization time as factors. The morphology ，particle size ，polymerdispersity index（PDI），EE，the viscosity ，the foam dissolution rate and in vitro transdermal release of BC-LN-FA were characterized. RESULTS The optimal technology included 25 mg BC ，40 mg emulsifier （mass ratio of stearic acid-soybean lecithin-glycerol was 1∶1∶1），30 mg co-emulsifier （mass ratio of octadecanol-lactic acid was 1∶1），homogenization time of 20 min. Results of 3 times of validation tests showed that particle size of prepared BC-LN-FA was （151.70±2.40）nm，EE was （68.62±1.16）％；the deviation of them from the predicted value （particle size of 150.80 nm，EE of 67.02％）were 0.60％ and 2.39％ respectively. The BC-LN-FA prepared by the optimal process was light yellow opalescence ，uniform in particle size and round-like in shape. The viscosity，the foam dissolution rate ，the content of BC and PDI were （122.92±5.09）mPa·s，（65.32±3.22）％，（7.01±0.12）％ and（0.199±0.006），respectively. At 48 h，the cumulative release rates of BC-LN-FA in phosphate buffer saline （PBS）at pH 7.4， 6.8，5.0 were（54.12±2.69）％，（57.85±4.25）％ and（59.47±1.83）％，respectively；those of free BC in PBS at pH 7.4 was only （15.04±1.43）％. CONCLUSIONS The optimized technology is stable and feasible. Prepared BC-LN-FA has a uniform particle size，high digestion rate and certain viscosity.
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Objective@#To describe digital media use in college students during the coronavirus disease 2019(COVID-19) outbreak.@*Methods@#A structured self-administered electronic questionnaire was designed and admin istered during February 4 to 12, 2020, collecting information on the use time of digital media and anxiety symptoms of college students in China during the COVID-19 outbreak. Data was analyzed by Chi-square test, univariate and multivariate Logistic regression models.@*Results@#A total of 11 787 university students were recruited. The detection rate of anxiety symptoms was 17.8%. The percentages of screen time ≤2, >2-4 and >4 h/d were 21.3%, 31.4% and 47.3%. The proportions of mobile phone use time ≤2, >2-4 and >4 h/d were 14.6%, 33.2% and 52.3%. The proportion of browsing information regarding COVID-19 ≤1, 1-2 and >2 h/d were 66.6%, 19.4% and 13.9%. The results of Logistic regression analysis revealed that the detection rate of anxiety symptoms was lower among the students having 2-4 h/d of screen time(OR=0.70, 95%CI=0.61-0.81), but higher among the students having more than 4 h/d of screen time(OR=1.13, 95%CI=1.00-1.28) compared with those having ≤2 h/d of video usage time. Compared with the mobile phone usage ≤2 h/d group, the detection rate was lower among >2-4 h/d group(OR=0.78, 95%CI=0.66-0.91). However, anxiety symptoms were more likely to occur in the group of > 4 h/d(OR=1.20, 95%CI=1.04-1.39). The detection of anxiety symptoms was higher in the group with more browsing time. The OR for anxiety symptoms detection rate was 1.55(1.38-1.75) among the students with >1-2 h/d of browsing information regarding COVID-19 and 2.15(1.89-2.44) among the students with >2 h/d of browsing information regarding COVID-19 compared with those with ≤1 h/d of browsing information regarding COVID-19.@*Conclusion@#During the epidemic period, the use of >2-4 h/d digital media helps to reduce the occurrence of anxiety symptoms. But the use of computers and mobile phones for more than 4 h/d is associated with higher level of anxiety symptoms among college students. Less screen time spent on fact-checking on COVID-19 might help reduce anxiety sympotoms among college students.
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OBJECTIVE： To study the effects of ethanol extract of Sanguis Draconis on the survival of perforating flap model in rats and PI3K/Akt/eNOS pathway. METHODS： Perforating flap model was established by cutting off surrounding vessels and keeping one perforator. After modeling， the rats were divided into model group （external use， normal saline） and ethanol extract of Sanguis Draconis （EESD， the content of dracorhodin was 75.08 mg/g） group （external use， 0.21 g/cm2）， with 10 rats in each group. They were given relevant medicine for consecutive 7 days， once a day. The flap survival rate and flap microvessel density were determined after given relevant medicine 7 days. Human umbilical vein endothelial cells （HUVECs） were reoxygenated and glycoconjugated 16 h after hypoxia and hypoglycemia to establish oxygen-glucose deprivation/oxygen-glucose recovery model of HUVECs. After modeling， model cells were divided into normal group， model group， dracorhodin high-concentration， medium- concentration and high-concentration groups （2.5， 1.0， 0.5 μg/mL）. After reoxygenated and glycoconjugated for 24 h， cells morphology was observed by microscope； cell viability and the content of NO were detected by MTT assay and colorimetry. mRNA expression of Akt， PI3K and eNOS， PI3K protein expression， the phosphorylation of Akt and eNOS protein were determined by RT-PCR and Western blot assay. RESULTS： In rat experiment， compared with model group， flap survival rate and microvessel density of rats were increased significantly in EESD group （P＜0.01）. In cell experiment， compared with normal group， the survival rate of HUVEC， NO content， mRNA expression of PI3K， Akt， eNOS，PI3K protein expression， the phosphorylation of Akt and eNOS protein were decreased significantly （P＜0.05 or P＜0.01）. Compared with model group， dracorhodin high-concentration， medium-concentration and high-concentration groups survival rate of HUVEC cells， NO content， mRNA expression of PI3K， Akt and eNOS， PI3K protein expression， the phosphorylation of Akt and eNOS protein were increased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： The survival rate of perforating flap model in rat can be increased by treating with EESD， the mechanism of which may be associated with the activation of PI3K/Akt/eNOS pathway to protect endothelial cells.
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OBJECTIVE： To establish a method for simultaneous determination of 4 triglyceride anti-tumor components in Coix lacryma seed oil. METHODS： HPLC-ELSD was adopted. The determination was performed on Inertsil ODS-3 C18 column with mobile phase consisted of acetonitrile-isopropanol （57 ∶ 43， V/V） at the flow rate of 1.0 mL/min. The column temperature was 30 ℃， and the sample size was 10 μL. Evaporative light scattering detector was used， the drift tube temperature was 70 ℃， and the gas flow rate was 2 L/min. Using glycerol trioleateas internal standard， relative correction factors （RCF） of linolein trilinolein， 1，2-linoleic acid-3-palmitic acid glyceride and 1-palmitic acid-2-oleic acid-3-linoleic acid glyceride were calculated respectively. The contents of above 3 components in C. lacryma seed oil were calculated by RCF. The contents of 4 components in C. lacryma seed oil were determined by external standard. The results of content determination by quatitative analysis of multi-components by single marker （QAMS） were compared with external standard method. RESULTS： The linear ranges were 0.15-4.50 μg for linolein trilinolein， 0.15-4.50 μg for 1，2-linoleic acid-3-palmitate， 0.35-10.50 μg for 1-palmitic acid-2-oleic acid-3-linoleic acid glyceride， 0.35-10.50 μg for glycerol trioleate （r≥0.999 5）. The limits of quantification were 0.13， 0.06， 0.07， 0.12 μg. The limits of detection were 0.04， 0.02， 0.02， 0.03 μg， respectively. RSDs of precision， stability， and repeatability tests were less than 2.0％（n＝6）. The average recoveries were 95.43％-102.67％（RSD＜2.0％， n＝6）. Average RCFs of linolein trilinolein， 1，2- linoleic acid-3-palmitic acid glyceride and 1-palmitic acid-2- oleic acid-3-linoleic acid glyceride were 0.31， 0.88， and 1.21， respectively. RCFs reproducibility was perfect under different experiment conditions. There was no significant difference in results of content determination between QAMS and external standard method （P＞0.05）. CONCLUSIONS： The method is simple， rapid， accurate and reliable. It is used for simultaneous determination of linolein trilinolein， 1， 2-linoleic acid-3-palmitate， 1-palmitic acid-2-oleic acid-3-linoleic acid glyceride and glycerol trioleateas in C. lacryma seed oil.