基于正交法及Kriging模型的生物反应器搅拌桨优化设计

针对搅拌桨标准中设计参数区间大,生物反应器搅拌桨设计时参数难以确定、剪切力及搅拌功率缺少参考依据的问题。基于正交法及CFD对200 L生物反应器搅拌桨进行优化,由极差分析得到三斜叶桨不同搅拌桨直径、桨叶宽度、搅拌桨中心离底距离和转速对桨叶剪切速率和搅拌功率的影响规律,并结合流场分析选择有利于细胞培养的设计方案。根据正交优化方案确定多目标优化变量区间,以剪切力和搅拌功率为优化目标,基于Kriging模型和多目标遗传算法提出了有利于细胞培养的三斜叶桨设计变量区间,并优化得到桨叶平均剪切力为0.789 Pa、搅拌功率为0.395 W的搅拌桨最优参数组合,为生物反应器不同实际需求下的设计、优化提供了方法及数据参考。

Intraoperative body temperature and emergence delirium in elderly patients after non-cardiac surgery:A secondary analysis of a prospective observational study

Background:Emergence delirium(ED)is a kind of delirium that occured in the immediate post-anesthesia period.Lower body temperature on post-anesthesia care unit(PACU)admission was an independent risk factor of ED.The present study was designed to investigate the association between intraoperative body temperature and ED in elderly patients undergoing non-cardiac surgery.Methods:This study was a secondary analysis of a prospective observational study.Taking baseline body temperature as a reference,intraoperative absolute and relative temperature changes were calculated.The relative change was defined as the amplitude between intraoperative lowest/highest temperature and baseline reference.ED was assessed with the confusion assessment method for intensive care unit at 10 and 30 min after PACU admission and before PACU discharge.Results:A total of 874 patients were analyzed with a mean age of 71.8±5.3 years.The incidence of ED was 38.4%(336/874).When taking 36.0°C,35.5°C,and 35.0°C as thresholds,the incidences of absolute hypothermia were 76.7%(670/874),38.4%(336/874),and 17.5%(153/874),respectively.In multivariable logistic regression analysis,absolute hypothermia(lowest value<35.5°C)and its cumulative duration were respectively associated with an increased risk of ED after adjusting for confounders including age,education,preoperative mild cognitive impairment,American Society of Anesthesiologists grade,duration of surgery,site of surgery,and pain intensity.Relative hypothermia(decrement>1.0°C from baseline)and its cumulative duration were also associated with an increased risk of ED,respectively.When taking the relative increment>0.5°C as a threshold,the incidence of relative hyperthermia was 21.7%(190/874)and it was associated with a decreased risk of ED after adjusting above confounders.Conclusions:In the present study,we found that intraoperative hypothermia,defined as either absolute or relative hypothermia,was associated with an increased risk of ED in elderly patients after non-cardiac surgery.Relative hyperthermia,but not absolute hyperthermia,was associated with a decreased risk of ED.Registration:Chinese Clinical Trial Registry(No.ChiCTR-OOC-17012734).

Antioxidant and immunomodulatory activities of a polysaccharide from Flammulina velutipes

OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crude polysaccharides were obtained. After purification by DEAE-cellulose 52 ion exchange chromatography and Sephacryl S-300 HR gel filtration chromatography, High performance liquid chromatography equipped with evaporative light-scattering detector, Infrared radiation and Nuclear magnetic resonance were used to evaluate the structure of the polysaccharide. Its immunomodulatory activity was measured by examining the production of nitric oxide(NO) and cytokine secretion, and via lymphocyte proliferation experiments. Its effects on the scavenging activities of hydroxyl radical, superoxide anion and reducing power were also measured.RESULTS: A water-soluble polysaccharide, Flammulina velutipes polysaccharide I-A(FVP I-A), was obtained with a molecular mass of 8.14×104Da determined by high performance gel permeation chromatography. An in vitro antioxidant assay indicated that FVP I-A could scavenge hydroxyl radical, superoxide anion and possessed reducing power and could largely promote NO production and augment the interleukin-1β, interleukin-6, and tumor necrosis factor-α secretion by RAW264.7 macrophages(P<0.05). Moreover, FVP I-A could promote lymphocyte proliferation(P<0.05), and synergistically enhance the augmentation of the proliferation of mouse lymphocytes by concanavalin A and lipopolysaccharides(P<0.01, P<0.05).CONCLUSION: The FVP I-A obtained from Flammulina velutipes possessed antioxidant activity and could enhance non-specific and specific immune responses in vitro.

k-dominant Skyline query algorithm for dynamic datasets

At present,most k-dominant Skyline query algorithms are oriented to static datasets,this paper proposes a k-dominant Skyline query algorithm for dynamic datasets.The algorithm is recursive circularly.First,we compute the dominant ability of each object and sort objects in descending order by dominant ability.Then,we maintain an inverted index of the dominant index by k-dominant Skyline point calculation algorithm.When the data changes,it is judged whether the update point will afect the k dominant Skyline point set.So the k-dominant Skyline point of the new data set is obtained by inserting and deleting algorithm.The proposed algorithm resolves maintenance isue of a frequently updated database by dynamically updating the data sets.The experimental results show that the query algorithm can efectively improve query eficiency.

Protein expression changes in cornea after collagen crosslinking

Riboflavin/UV-mediated corneal collagen cross-linking can increase the mechanical strength of the cornea and prevent or delay corneal expansion and keratoconus progression.We performed quantitative analysis of protein iTRAQ in rabbit eye white matter after cross-linking to explore the changes of protein expression in cornea at different times after cross-linking and to understand the process of corneal stroma remodeling after cross-linking.The screening conditions are fold Change
1.2 and P-value<0.05,we identified 713 and 38 differentially expressed proteins in cornea at 1 week and 1 month after cross-linking.There were 16 differentially expressed proteins at two time points after corneal cross-linking.By annotating the functions of these proteins,we identified some proteins that affect the mechanical properties of the cornea,and these proteins are involved in cell growth,oxidative stress response,and signal transduction in the cornea.It has a guiding role in studying the corneal stroma remodeling process after collagen crosslinking.