During L-lactic acid fermentation with Rhizopus oryzae,there existed a branch pathway by which pyruvate was transformed to eth- anol catalyzed by pyruvate decarboxylase(PDC)and alcohol dehydrogenase(ADH),thus decreasing the flux of pyruvate to lactic acid.In this study,the spores of Rhizopus oryzae AS3.3462 mutagenized with nitrosoguanidine(NTG),the appropriate dosage was 0.15 mg/mL and the lethal rate was 70%～80%.Two mutants,named mut-1 and mut-2,with decreased ADH activity were screened out by yeast peptone dextrose(YPD)agar medium containing allyl alcohol.These two mutants had decreased ADH activities of 41.63% and 50.29% compared with the parent strain.The fermentation behavior after 72h showed that the yields of ethanol produced by mut-1 and mut-2 were 4.87g/L and 6.56g/L respectively,while the wild type strain was 28.9g/L,and the lactate concentrations of mut-1 and mut-2 also increased from 40.31g/L to 54.45g/L and 44.07 g/L,respectively.It is also found that mut-1 and mut-2 had a high reducing sugar consumption rate and biomass accumulation than its present strain

Aldehydes ; chemistry ; pharmacology ; Chromatography, High Pressure Liquid ; DNA Adducts

Objective: To explore the effect of psychotherapy in treating middle school students with IAD (internet addiction disorder). Methods: 23 cases of middle school students with IAD had been treated by cognitive therapy or behavior therapy. The IAD scale, SCL-90 scale and SDS scale were used to evaluate the effect before and after therapy. Results: After therapy, the total scores and most dimensions scores in IAD scale, SCL-90 scale and SDS scale decreased significantly than that before therapy. Conclusions: Psychotherapy especially cognitive therapy and behavior therapy is an effective in treating middle school students with IAD.

Workplace

Administration, Inhalation ; Animals ; Disease Models, Animal ; Female ; Fluorine ; blood ; Fluorocarbons ; adverse effects ; pharmacokinetics ; Male ; Rabbits ; Rats

Using bioactive compounds 7-hydroxy flavone, salicylaldehyde, cinnamic acid and 4-amino-5- mercapto-1,2,4-triazoles as starting materials, three new types of flavone derivatives containing 1,2,4-triazole structure were synthesized via different step reactions. These new compounds were characterized by 1IHNMR, ESI-MS, IR and elemental analysis. Their scavenging effects on the superoxide radical (O2·-), hydroxyl radical (·OH), DPPH · radical and their total reduction activities were tested. The results showed that all of the compounds possessed some antioxidative activity at the concentration of 0.5 mg · mL(-1), but the scavenging ability of the target compounds was lower than that of the standard compound Vc.
Cinnamates ; chemistry ; Flavones ; chemical synthesis ; chemistry ; Flavonoids ; chemistry ; Free Radical Scavengers ; chemical synthesis ; chemistry ; Triazoles ; chemistry

Objective To search for a good method for generation of hematopoietic stem cells (HSC) by embryonic stem cells (ESC),and to investigate the potential of HSC derived from ESC to reconstruct hematopoiesis in vivo.Methods Using a three-step method to induce a mice ESC line, E14.1-into HSC.And identifying HSC by flow cytometry analysis cell markers with CD34 +/Sca-1+, then HSC (1×109L-1)from ESC differentiation were injected into severe combined immunodefieency (SCID) mice for observing teratoma formation.To validate function of HSC by colonngenic cells assay and to reconstitute the hematopoiesis in lethally irradiated mice.Results Combining to use more hematopoietic stimulating factor to availably promote the El4.1 cell into embryoid body (EBs) with abundant hematopoietic progenitors.EBs were induced after 14 day to fast differentiate for HSC with peak percentages of CD34+/Sca-1+ cells reached to (13.72±2.07)%.To harvested ceils from EBs by day 14 for second -step HSC differentiation, percent of CD34+/Sca-1+ cells rise to(24.62±2.50) % after day 16 induction.Cloning forming units (CFU) analysis showed that more Erythro -myeloid cloning generation was observed at this period.Cells obtained in the second step are subsequently plated on monolayer of mice bone marrow stromal cells, in the presence of TPO, FLt3 ligand and superoatant of mice fetal liver stromal cells, cultured for additional 15 days, followed fast expansion of CD34+/Sca-1+ to maximally (58.64±4.20 ) % with more CFU-E, CFU-GM and CFU-GEMM population.Wright-Giemsa stain showed that its had the character of hematopoietic progenitors.Cells from the third-step were injected into SCID mice, but no teratomas were recovered in 2 mices after 6 weeks.Positive selection of CD34+/Sca-1+ cells by magnetic sorting from the third - step differentiation were transplanted into 7 lethally irradiated female mice while predominant hematopoietic reconstitution were observed in 10 days after transplantation, with 71.4% successful engraftment rate.And 3 recipients showed that the cell population of the peripheral blood leukocytes,red cells, hemoglobin approached normal index at 40 days after transplant, hut followed relative'slow renew in platelet count.Survival rate of transplant group is 43.0%, compared to 100% mortality in control mice.Karyotyping assays confirmed female mice with XY.Conclusions The results showed that the three-step differentiation and the culture conditions described here good support differentiation of ESC into HSC.HSC derived from ESC were safe without teratomas formation in body, and its can reconstruct hematopoiesis.

CAS (Chrome azurol S) assay was a universal method for detecting the bacterial siderophores, and Sugar-Asn liquid medium has been applied to the studies on siderophores from Pieudomonas. In this paper, Asp has been substituted for Asn, and MSA-CAS agar plate was developed by integrating the MSA (sugar-Asp) medium and CAS bright blue dye, which has been used in the universal CAS assay. On the aspect of siderophores detection , 8 strains of 7 species from Pseudomonas had been screened on MSA-CAS agar plates and universal CAS assay respectively. The results showed that MSA-CAS agar was higher-sensitive and lower basic fluorescent than universal CAS assay.

A novel stable blue agar plate which is convenient to preparing and more effective than the universal chrome azurol sulfonate (CAS) assay established by Schwyn and Neilands was designed by replacing MM9 growth medium and pipes with certain concentrate of phosphorus buffer solution which pH could be stabled at 6.8. It is more suitable for screening over- siderophores production bacteria. Since OD_ 630 of the sample is usually out of the range of spectrophotometer with CAS assay solution when quantifying the siderophores and the outcome is not steady,the measuring wavelength had been changed to 680 nm corresponding to the middle of max absorbance and the correlation between siderophores concentrations and OD was unchanged. But the detecting sensitivity is elevated by enlarged the absorbance differences among samples with different productivity of siderophores at 680 nm .

Bacterial cellulose (BC) is a natural polymer that has bioactivity, biodegradability and biocompatibility. It displays unique physical, chemical and mechanical properties including high crystallinity, high water holding capacity, nanofibre-network structure, high tensile strength and elastic modulus. Due to its unusual material properties, BC has recently become a kind of attractive biomedical material in the international research.Describes BC's properties, study history and its applications as biomedical materials, especially gives emphasis to introduce the applications of BC on scaffold tissue engineering, artificial blood vessels, artificial skin and the treatment of skin wound, as well as the present study status.