Sugarcane bagasse modified by polyethylenimine (PEI) and glutaraldehyde (GA) was used as a carrier to immobilize Clostridium acetobutylicum XY16 in the process of butanol production. The effects of chemically modified sugarcane bagasse on batch and repeat-batch fermentations were investigated. Batch fermentation was conducted with an addition of 10 g/L modified sugarcane bagasse and 60 g/L glucose, resulting in a high solvent concentration of 21.67 g/L and productivity of 0.60 g/(L x h) with the treatment of 4 g/L PEI and 1 g/L GA. Compared to the fermentations by free cells and immobilized cells on unmodified sugarcane bagasse, the productivity increased 130.8% and 66.7%, respectively. The fibrous-bed bioreactor also maintained a stable butanol production during repeat-batch fermentations, achieving a maximum productivity of 0.83 g/(L x h) with a high yield of 0.42 g/g.
Batch Cell Culture Techniques ; Bioreactors ; Butanols ; metabolism ; Cells, Immobilized ; Cellulose ; metabolism ; Clostridium acetobutylicum ; metabolism ; Fermentation ; Saccharum ; chemistry

BACKGROUND:Cryopreservation of human umbilical cord mesenchymal stem cel s has been a hot research issue currently, but the studies concerning their effects on expansion of hematopoietic stem/progenitor cel s after cryopreservation are seldom. OBJECTIVE:To investigate the effects of human umbilical cord mesenchymal stem cel s before and after cryopreservation as feeder layer on expansion of human bone marrow mononuclear cel s in vitro. METHODS:2.5g/L mitomycin C processed human umbilical cord mesenchymal stem cel s and bone marrow mesenchymal stem cel s at passage 3 were used as the feeder layer to expand adult al ogeneic bone marrow mononuclear cel s in culture. Up to day 35, methylcel ulose assay was used to detect hematopoietic stem/progenitor cel colony proliferation. RESULTS AND CONCLUSION:There were no differences in the morphology and size of colonies in the cryopreserved human umbilical cord mesenchymal stem cel group, bone marrow mesenchymal stem cel group and non-cryopreserved human umbilical cord mesenchymal stem cel group. However, these parameter described above were significantly higher in these three groups than the blank control group (P<0.05). There were fewer colonies in the cryopreserved human umbilical cord mesenchymal stem cel group than the non-cryopreserved human umbilical cord mesenchymal stem cel group (P<0.05). These findings indicate that human umbilical cord mesenchymal stem cel s before and after cryopreservation have the ability as feeder layer on expansion of bone marrow mononuclear cel s in vitro similar to bone marrow mesenchymal stem cel s. But this ability of human umbilical cord mesenchymal stem cel s may decrease after cryopreservation.

Objective To analysis the therapeutic effect of microsurgery through single-nostril transsphenoidal approach on pituitary adenomas and to study the surgical skill and postoperative complications about microsurgery for pituitary adenomas.Methods The clinical manifestations,pathological type, removal percentage,postoperative complications and follow-up data of 241 cases with pituitary ademoma by microsurgery through single-nostril transsphenoidal approach were analysed retrospectively.Results 171(7 1%)cases were achieved total tumor removal,28(11.6%)cases were achieved subtotal tumor removal,26(10.7%)cases were achieved most tumor removal and 16(6.6%)cases were achieved partial tumor removal.Most of patients achieved better results,however there were 38(15.8%)eases with diabetes insipidus,12(4.9%)cases with transient worse sight,4(1.6%)cases with cerebrospinal fluid leakage,2(0.8%)cases with oculomotor paralysis,and no death.The postoperative complications were cured and outcome was considered as good.The follow-up period was 1-36 months in 241 patients and the clinical symptoms were improved by different degrees.Conclusion Pituitary adenomas can be treated by microsurgery through single-nostril transsphenoidal approach due to the time of operation shorten,the postoperative complications.

Objective To evaluate the relationship between sevoflurane-induced cognitive decline and α1A norepinephrine receptor (ADRA1A) in the cerebral cortex of rats.Methods Forty-eight cleangrade healthy adult Sprague-Dawley rats (24 male,24 female),weighing 220-260 g,aged 3-4 months old,were divided into 2 groups (n =24 each) using a random number table method:control group (group C) and sevoflurane group (S group).Group S inhaled 3％ sevoflurane for 5 h.Rats underwent the Barnes maze test on days 1 and 7 after anesthesia.Rats were sacrificed immediately after anesthesia and on days 1 and 7 after anesthesia,and the cerebral cortex was removed for determination of the expression of ADRA1A protein and mRNA (by Western blot or fluorescent quantitative real-time polymerase chain reaction).Results Compared with group C,the number of entering incorrect holes was significantly increased,and the latency of entering the target hole and the distance were prolonged,and the expression of ADRA1A protein and mRNA in cerebral cortex was down-regulated at each time point in group S (P＜0.05).Conclusion The mechanism of sevoflurane-induced cognitive decline is related to down-regulated expression of ADRA1A in the cerebral cortex of rats.

Objective:To investigate the effects of exogenous nitric oxide (NO) on radiation response of nasopharyngeal carcinoma 5-8F radiotherapy resistant cell line (5-8FRs) and to provide experimental basis for finding suitable radiosensitizer on nasopharyngeal carcinoma.Methods:5-8FRs cells were cultured in vivo and treated with sodium nitroprusside (SNP) of different concentrations. The inhibition rate of cell proliferation was detected by cell counting kit-8 (CCK8) method. A concentration of IC 01 SNP (1% SNP) which had no obvious effect on the proliferation of 5-8FRs cells was screened out. The 5-8FRs cells were intervened with 1, 2, 4, 6 Gy and 8 Gy radiation to determine the radiation dose of IC 15 (15% radiation dose). 5-8FRs cells were treated with IC 01 SNP concentration, IC 15 radiation dose and radiotherapy alone or in combination. The morphological changes of 5-8FRs cells were observed under microscope. The proliferation inhibition rate of each group was detected by CCK-8 method, the apoptosis was detected by flow cytometry, and the concentration of NO in cell supernatant was detected by nitrate reduction method. Results:⑴ The proliferation of 5-8FRs had been inhibited in a concentration-dependent manner by SNP and a dose-dependent manner by radiation. The SNP concentration of IC 01 was (513.89±14.69)μmol/L (SNP group). The radiation dose of IC 15 was (3.96±0.33)Gy (radiotherapy group); ⑵ Compared with single SNP group and radiotherapy group, the morphology of 5-8FRs cells in combination group (SNP+ radiotherapy) was significantly different, floating cells increased significantly, the number of adherent cells gradually decreased and lost their original morphology; ⑶ SNP concentration of IC 01 had no significant effect on the proliferation of 5-8FRs cells, but the inhibition rate of combined group was significantly higher than that of radiotherapy group ( t=7.708, P<0.01); The concentration of NO in the combined group was significantly higher than that in the single radiotherapy group [(310.03±5.76)μmol/L vs (77.34±2.60)μmol/L, P<0.05]; ⑷ The spontaneous apoptosis rate of 5-8FRs was (1.35±0.06)%, while the apoptosis rate in the group of IC 01SNP was (2.22±0.37)%, with no significant difference. The apoptosis rate of 5-8FRs in the combined group (50.27±2.24)% was significantly higher than that of the group of IC 15 radiation dose(15.37±0.65)%. Conclusions:Under no obvious toxicity to cells themselves circumstances, exogenous nitric oxide with appropriate concentration could significantly enhance the radiosensitivity on 5-8FRs.

Objective To evaluate the relationship between sevoflurane-induced cognitive impairment and α1B adrenoceptors (ADRA1B) and ADRA1D in the cerebral cortex of rats.Methods Forty-eight SPF adult Sprague-Dawley rats (half male,half female),weighing 220-260 g,were divided into control group (C group,n =24) and sevoflurane group (S group,n =24) using a random number table method.Group C and group S inhaled air and 3％ sevoflurane,respectively,for 5 h.Eight rats in each group were sacrificed immediately after anesthesia,and the cerebral cortex was removed.Eight rats in each group were selected on days 1 and 7 after anesthesia and underwent Barnes maze test.The rats were then sacrificed,and the cerebral cortex was removed.The expression of ADRA1B and ADRA1D protein and mRNA in cerebral cortex tissues was detected by Western blot and fluorescent quantitative real-time polymerase chain reaction,respectively.Results Compared with group C,the number of entering incorrect holes was significantly increased at 1 and 7 days after anesthesia,the latency and total distance to enter the target hole were prolonged,and the expression of ADRA1B and ADRA1D protein and mRNA in cerebral cortex was down-regulated immediately after anesthesia and at 1 and 7 days after anesthesia in group S (P＜0.05).Conclusion The mechanism underlying sevoflurane-induced cognitive impairment may be related to the down-regulated expression of ADRA1B and ADRA1D in cerebral cortex of rats.

Objective To evaluate the effect of sevoflurane anesthesia on the expression of hippocampal α4 subunit-containing nicotinic acetylcholine receptor (α4nAChR) in rats.Methods One hundred and forty-four Sprague-Dawley rats of both sexes,aged 3-4 months,weighing 220-270 g,were divided into 4 groups (n =36 each) using a random number table:control group (group C),sevoflurane anesthesia for 1 h group (group S1),sevoflurane anesthesia for 3 h group (group S2) and sevoflurane anesthesia for 5 h group (group S3).Group C inhaled air,and S1,S2 and S3 groups inhaled 3％ sevoflurane for 1,3 and 5 h,respectively.Twelve rats in each group were selected at 1 and 7 days after emergence from anesthesia to undergo spatial probe test.Rats were then sacrificed immediately after anesthesia and at 1 and 7 days after emergence from anesthesia,and hippocampi were removed for determination of the expression of α4nAchR protein and mRNA in hippocampal neurons (by Western blot or real-time polymerase chain reaction).Results Compared with group C,the duration of staying at the target quadrant was significantly shortened,and the ratio of duration of staying at the original platform quadrant to the total duration and ratio of swimming distance in the original platform quadrant to the total distance were decreased on 1 and 7 days after emergence from anesthesia,the expression of α4nAchR protein and mRNA was down-regulated,and the number of positive cells was reduced in S1,S2 and S3 groups (P＜0.05).Compared with S1 and S2 groups,the duration of staying at the target quadrant was significantly shortened,the ratio of duration of staying at the original platform quadrant to the total duration and ratio of swimming distance in the original platform quadrant to the total distance were decreased on 1 day after emergence from anesthesia in group S3 (P＜0.05).There was no significant difference in the expression of α4nAchR protein and mRNA or number of positive cells at each time point between group S1,group S2 and group S3 (P＞0.05).Conclusion The mechanism by which sevoflurane anesthesia induces cognitive dysfunction may be partially related to down-regulating the expression of hippocampal α4nAchR in rats.

This study explores the application effect of the case-based teaching method based on Xuexitong learning platform in the online teaching of Digestive System, and analyzes the learner's emotional experience, learning behavior, and learning effect in the case-based online teaching. The results of the study show that the case-based online teaching model based on Xuexitong learning platform improves students' online learning interest, and the students have good emotional experience, high learning enthusiasm, good classroom interaction, enhanced self-learning ability before and after class, and good learning effect. In addition, precise teaching can be used for individual students who are not enthusiastic about online learning.