Preparation of Graphene/Gold Nanoparticles/Glucose Oxidase Flexible Electrode Based on Poly(ethylene terephthalate) Film and Its Application in Detection of Glucose / 分析化学

The graphene prepared by chemical vapor deposition onto copper foils was transferred onto a poly(ethylene terephthalate) (PET) soft substrate by the aid of poly-methyl methacrylate (PMMA).The soft G/AuNPs/GOD composite electrode based on PET substrate was fabricated using a protocol in which the uniform distribution of Au nanoparticles (AuNPs) was firstly obtained by controlling the evaporation of gold sol on a graphene surface, then thioglycolic acid (TGA) was modified on the AuNPs through Au-S bond, and finally glucose oxidase (GOD) was immobilized on the surface of AuNPs through acylation reaction between TGA and the GOD.Glucose was detected in the linear range from 0.05 to 10.55 mmol/L with a linear correlation coefficient (r) of 0.9955.The detection was performed in phosphate buffer solution (pH 7) at 25℃ with a working potential of 0.6 V (vs.SCE electrode), and the detection limit was 1 μmol/L (3σ).The G/AuNPs/GOD flexible electrode based on PET substrate provided a new pathway to detect glucose in special environments using wearable equipment, which enlarged the applied field of glucose detection.

Progress in digital PCR technology and application / 生物工程学报

Digital PCR is an emerging analysis technology for absolute quantification after realtime-PCR. Through digital PCR, single DNA molecules are distributed into isolated reactions, and the product with fluorescence signal can be detected and analyzed after amplification. With the advantages of higher sensitivity and accuracy, digital PCR, independent of a standard curve, is developing rapidly and applied widely to the next generation sequencing and detection fields, such as gene mutation, copy number variation, microorganism, and genetically modified food. In this article, we reviewed the quantitative method and research progress of digital PCR technology in the main application fields.

Regional analysis of HIV-1 viral load changes among AIDS patients treated with antiretroviral therapy in 2009-2014 / 国际检验医学杂志

Objective To analyze the changes of HIV‐1 viral load and virological efficacy of treatment effects for AIDS patients treated with antiretroviral therapy from 2009 to 2014 in Lincang City .Methods Monitored the HIV‐1 viral load for 13 491 cases of AIDS patients treated with highly active antiretroviral therapy(HAART) from 2009-2014 in Lincang City of Yunnan and analyze the monitoring data .If the patients had treated with HAART were still with viral load greater than 1 000 copy/mL ,the treatment was defined as a failed treatment or a virological failure .Results The total rate of virological failure was 14 .34% (1 935/13 491) . The rate of virological failure of children group was 15 .53% (50/322) ,and of adults group was 14 .31% (1 885/13 169) .There was no statistically significant difference between childeren and adults(χ2 =0 .38 ,P>0 .38) .The rate of virological failure in males was 16 .34% (1 156/7 076) ,and 12 .14% (779/6 415) in females ,the difference was statistically significant between men and female (χ2 =48 .16 ,P<0 .01) .Conclusion Antiretroviral treatment can delay the disease progression and improve the life quality .

Characterization and evaluation of an astaxanthin over-producing Phaffia rhodozyma / 生物工程学报

We evaluated an astaxanthin overproducing Phaffia rhodozyma JMU-MVP14, and developed astaxanthin high-yielding fermentation process. We analyzed several fermentation parameters, i.e., biomass, astaxanthin and total carotenoids content to compare the characteristics of P rhodozyma JMU-MVP14 and the original strain through flask fermentation experiments. We conducted batch and fed-batch fermentation experiments in 7 L fermentor to investigate the effects of pH controlling models and feeding medium compositions on the production of astaxanthin. We further evaluated the capability and practical value of P rhodozyma JMU-MVP14 by fed-batch cultivation in the 1 m3 fermentor. Flask fermentation experiments revealed that P. rhodozyma JMU-MVP14 produced high yield of astaxanthin and carotenoids with specific productivity of astaxanthin and specific productivity of total carotenoids of 6.01 mg/g and 10.38 mg/g. Results of batch culture experiments in the 7 L fermentor showed that controlling the pH by ammonia auto-feeding was better than discontinuously adjusting pH value at 6.0 with regard to the high productivities of biomasses and astaxanthin. This P. rhodozyma strain synthesized astaxanthin partially linked to the growth with the Ks and pmax of 0.20 h ' and 21.73 g/L, respectively. Results of batch-fed fermentations in 7 L fermentor indicated that the complex feeding medium consisted of 50% glucose, 0.5% yeast extract and 0.3% corn steep syrup had lower astaxanthin productivity than the simple feeding medium containing only 50% glucose, which produced biomass, volumetric productivity of astaxanthin, volumetric productivity of total carotenoids, specific productivity of astaxanthin and total carotenoids at 32.81 g/L, 155.99 mg/L, 4.94 mg/g, 399.99 mg/L and 12.19 mg/g, respectively. As fed-batch cultured in 1 m3 fermentor, P rhodozyma JMU-MVP14 yielded 85.11 g/L of biomass, 279.96 mg/L of volumetric productivity of astaxanthin, 618.01 mg/L of volumetric productivity of total carotenoids, 3.29 mg/g of specific productivity of astaxanthin and 7.26 mg/g of specific productivity of total carotenoids. Additionally, P rhodozyma JMU-MVP14 cell contained 21.54% of protein, 41.34% of carbohydrate and 34.31% of lipid. These comprehensive results suggest that P. rhodozyma JMU-MVPl14 has great practical prosperity related to its strong ability to produce astaxanthin and good value byproducts.

Technological process of cell disruption for extracting astaxanthin from Phaffia rhodozyma by acid method under autoclave conditions / 生物工程学报

Phaffia rhodozyma is one of the organisms for production of astaxanthin, and the key process for extracting intracellular astaxanthin is cell disruption. In this work, cell disruption for extracting astaxanthin from Phaffia rhodozyma was studied with autoclave method at low acid concentration. The optimum disrupting conditions were: autoclave pressure 0.1 MPa, 121 degrees C; hydrochloric acid concentration 0.5 mol/L; liquid to material ratio (V/W) 30 mL/g dry cell weight and disruption time 2 min. Under the optimum conditions, medium scale experiment showed that astaxanthin and total carotenoids recovery from Phaffia rhodozyma were (84.8 +/- 3.2)% and (93.3 +/- 2)%, respectively. This new method can lead to no poisonous residues and get high extraction yield, which have good prospects to be put into industrial production.

Pathogen Detection in Food Poison Episodes / 中华医院感染学杂志

OBJECTIVE TO improve the detection leval of bacterial pathogens caused food poison episodes. METHODS The baterial pathogens were cultured and identified in two food posison episodes.The antibiotic susceptibiity test was undertaken,retrospetirely. RESULTS Five enterotoxin-producing S.aureus strains were isolated from 55 samples collected in one event,and five enterotoxin-producing salmonella enteritidis strains were isolated from 66 samples collected in another event. CONCLUSIONS The two outbreak events are caused by bacteria contaminated foods.

Retinoic acid receptor beta is required for anti-activator protein-1 activity by retinoic acid in gastric cancer cells / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the role of retinoic acid receptor beta (RARbeta) in mediating inhibitory effect of all-trans retinoic acid (ATRA) on activator protein-1 (AP-1) activity in gastric cancer cells.</p><p><b>METHODS</b>Transient transfection and chloramphenicol acetyltransferase (CAT) assay, Nort hern blot, gene transfection, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and anchorage independent growth assay were used.</p><p><b>RESULTS</b>Transient transfection of RARbeta expression vector into MKN-45 cells resulted in the RARbeta concentration dependent repression of AP-1 activity induced by 12-o-tetradecanoylphorbol-13-acetate (TPA), regardless of the presence of ATRA. When the c-jun and c-fos expression vectors were cotransfected with the RARbeta expression vector into MKN-45 cells, AP-1 activity was also obviously repressed. The inhibitory effect, again, was RARbeta-concentration-dependent. The stable transfection of the RARbeta gene into MKN-45 cells led to cell growth inhibition and colony formation inhibition by ATRA. Furthermore, Cotransfection of both RARbeta/DNA binding domain (DBD) and reporter gene could not alter AP-1 activity, even in the presence of ATRA.However, when the cotransfection was substituted with the RARbeta/ligand binding domain (LBD), the inhibition was significantly enhanced by ATRA.</p><p><b>CONCLUSION</b>RARbeta might be required for anti-AP-1 activity, and contribute to growth inhibition of gastric cancer cells by ATRA.</p>

Detection of major allergen parvalbumin in fish / 中国免疫学杂志

Objective:To develop an indirect enzyme-linked immunosorbent assay (ELISA) for semi-quantification of major allergen parvalbumin in fish.Methods:The soluble proteins were prepared from both white and dark muscles of seven species of freshwater fish and five species of marine fish.Tricine-SDS-PAGE and Western blot were performed to examine the protein patterns of fish muscle extracts.Natural parvalbumin being used to make calibration curve was purified from silver carp (Hypophthalmichthy molitrix) by ammonium sulphate fractionation,followed by ion exchange and gel filtration chromatography.The molecular mass of purified protein was estimated by Tricine-SDS-PAGE and identified by Western blot with anti-frog parvalbumin monoclonal antibody PARV-19.ELISA using PARV-19 was carried out to evaluate parvalbumin contents in white and dark muscles.Results:Tricine-SDS-PAGE revealed species-specific differences in proteins of heated extracts.Western blot confirmed that the major bands were showed in Tricine-SDS-PAGE with the molecular masses of 10-14 kD corresponded to parvalbumins recognized by PARV-19 and various numbers of isoforms of parvalbumin existed in different species of fish.There might be some differences in the parvalbumin contents and the epitope region was recognized by PARV-19 based on the differences in relative intensities of protein immunodetection.The ELISA showed that the contents of parvalbumin were 4 to 33 folds higher in the white muscle than in the dark muscle and varied greatly in different species of fish.Conclusion:These results validate that the dark muscle might be less allergenic than the white muscle due to the lower content of parvalbumins,and it is suggested that the commercial anti-parvalbumin antibody PARV-19 can be used to detect parvalbumins from the commercially important species of fish tested in this study and the method we develope succeeds to detect the major allergen in various species of fish.