The cis-epoxysuccinate hydrolase (CESH) from Rhizobium strain BK-20 is the key enzyme for L(+)-tartaric acid production. To establish a highly efficient and stable production process, we first optimized the enzyme production from Rhizobium strain BK-20, and then developed an immobilized cell-culture process for sustained production of L(+)-tartaric acid. The enzyme activity of free cells reached (3 498.0 +/- 142.6) U/g, and increased by 643% after optimization. The enzyme activity of immobilized cells reached (2 817.2 +/- 226.7) U/g, under the optimal condition with sodium alginate as carrier, cell concentration at 10% (W/V) and gel concentration at 1.5% (W/V). The immobilized cells preserved high enzyme activity and normal structure after 10 repeated batches. The conversion rate of the substrate was more than 98%, indicating its excellent production stability.
Alginates ; chemistry ; Cells, Immobilized ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Hydrolases ; metabolism ; Rhizobium ; enzymology ; metabolism ; Tartrates ; metabolism

Objective To investigate the correlation between three gene locus polymorphisms of X-ray repair cross-complementary protein 1 (XRCC1) exon (Arg194Trp, Arg280His and Arg399Gln) and the risk of colorectal cancer (CRC). Methods A case-control study was performed in 250 CRC patients (case group, 128 colon cancer patients and 122 rectal cancer patients) and 213 healthy individuals (control group). The three gene locus polymorphism of XRCC1 was tested by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. The genotype distribution and allele frequency of each locus was analyzed with SPSS 10.0 software. Results There was no significant difference in allele frequency of XRCC1 at 194 and 399 loci (P > 0.05). However, the 280 Arg/His allele frequency of XRCC1 was higher in case group than that in control group (OR=1.66,95%CI:1.01~2.73,P=0.047). The 280Arg/His allele frequency was higher in rectal cancer group than that in control group (OR =1.82,95%CI:1.02~3.27). The frequency of 280His allele (Arg280His and His280His) was higher in case group than that in control group (OR=1.85,95%CI:1.06~3.22). However, it was a relative low risk factor of colon cancer and there was no significant difference between colon cancer group and control group (OR=1.85, 95%CI:1.06~3.22). Conclusions There was no correlation between XRCC1 Arg194Trp and Arg399Gln polymorpohisms and the risk of CRC. However, 280Arg/His genotype may increase the risk of CRC, and 280His allele is a risk factor of rectal cancer.

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Objective:To evaluate and summarize the best evidence of exercise instructions for patients with atrial fibrillation.Methods:A comprehensive search about evidence on exercise rehabilitation in patients with atrial fibrillation was conducted in following databases: Joanna Briggs Institute (JBI) Library, The Agency for Healthcare Research and Quality (AHRQ), National Institute for Health and Clinic Excellence (NICE), Scottish Intercollegiate Guidelines Network (SIGN), Registered Nurses′ Association of Ontario (RNAO), Physiotherapy Evidence Database (PEDro), American College of Physicians (ACP), Cochrane Library, PubMed, Embase, CINAHL, Medlive, China National Knowledge Infrastructure (CNKI), WanFang Database, VIP Database, and China Biology Medicine (CBM). The retrieval period was from the inception of databases to January 2021. Two researchers with evidence-based nursing background assessed the quality of the literature independently and identified the level of evidence.Results:A total of 16 articles were included, including 4 guidelines, 4 systematic reviews, 4 expert consensuses, 4 randomized controlled trials. Combined with professional judgment, 35 pieces of best evidence in 7 aspects were summarized, including exercise benefits, the appropriate crowd, exercise evaluation, exercise mode, exercise intensity, exercise time, exercise supervision and safety.Conclusions:Regular exercise is safe and beneficial for patients with atrial fibrillation. Clinical staff should guide patients to exercise moderately by applying the best evidence with scientific exercise intervention, promoting patients′ physical and mental health.

Objective To observe the effects of Coix seed injection on the cell viability and radiosensitivity of human hepatoma cell line Bel-7402.Methods Bel-7402 cells were irradiated by X-rays,or treated with Coix seed injection,or treated with both of them.The cells proliferation and apoptosis were detected by MTT and by flow cytometry respectively.Cell cloning was used to observe the number of viable cells and to draw the cell survival curve.The mRNA and protein level of Bax,Bcl-2 were detected by RT-PCR and Western blot respectively.Results It was found that the Coix seed injection group (12 μmol/L) and X-ray group (8 Gy) had a significant inhibitory effect on the growth of hepatocellular carcinoma cells (t =17.03,11.26,P ＜ 0.05).And compared with Coix group and irradiation group,the combined treatment group showed higher inhibition rate (t =24.80,20.19,P ＜0.05).The mRNA and protein levels of Bax were gradually elevated (F =437.92,67.91,P ＜ 0.05),while the expressions of Bcl-2 reflected a decreased trend (F =31.18,48.50,P ＜ 0.05).The D0 values of pure irradiation group and combined treatment group were 4.27 and 3.34,respectively,and the sensitization enhancement ratio was 1.27.Conclusions The Coix seed injection inhibit cell growth and induce apoptosis,as well as increase radiative sensitization may via the apoptosis related factors Bax and Bcl-2 in hepatocellular carcinoma.

Purpose To investigate the value of T2WI mild-moderate signal and restricted diffusion in the context of liver imaging reporting and data system (LI-RADS) (2014 edition) in the diagnosis of hepatocellular carcinoma (HCC) with cirrhosis caused by hepatitis B virus.Materials and Methods A total of 77 lesions (LI-RADS 3-5,size of 1.1 cm×0.7 cm-12.7 cm×9.1 cm) of 69 HCC patients in Beijing Friendship Hospital from January 2012 to November 2016 were retrospectively analyzed.All these patients underwent MRI scan and multiphase dynamic enhanced scan.The images were analyzed by two radiologists.If a disagreement occurred,liver accelerated volume acquisition and multiphase dynamic enhanced scan were combined to reach a consensus.The contrast noise ratio (CNR) and apparent diffusion coefficient (ADC) of T2WI and diffusion weighted imaging (DWI) sequences were compared,as well as the identification of the two signs.Results There was no statistically significant difference between T2WI mild-moderate signal and restricted diffusion in the identification of lesions (LI-RADS 3-5) (P＞0.05),while the sensitivity with DWI b=0 (61.0％) was significantly lower than DWI b=600 s/mm2 (70.1％) (P＜0.05).The CNR of all DWI sequences (b=0,600 s/mm2) were larger than those of T2WI (P＜0.01).The ADC of small lesions (diameter ＜2 cm) were larger than those of larger lesions (diameter ＞2 cm) [(1.57+0.37)×10-3 mm2/s vs.(1.37+0.51)×10 3 mm2/s,P＜0.05].Conclusion There is no significant difference in sensitivity of lesions between T2WI mild-moderate signal and restricted diffusion.However,due to different CNRs,DWI with b=600 s/mm2 is more obvious for the lesions,and can be first investigated in practice.