Bacillus subtilis is a good producer of mannanase.This is the first study to investigate mannanase production under solid state fermentation(SSF) by Bacillus subtilis.Bacillus subtilis WY34 was used for the production of extracellular mannanase in the SSF of wheat bran.The highest mannanase activity was 7,650 U/g dry matter when the following conditions were used: wheat bran 5g,initial moisture content 71%,Tween-80 1%,konjac powder 0.4 g,initial pH 7.0,incubation temperature 50 ℃.Enzyme production was increased 178% after optimization.

Bioreactor is a key equipment in bioengineering.The bioprocessing efficiency using bioreactors is significantly affected by the reactor configuration.It is apparent that research on the bioreactor structure is one of key issues in bioengineering.Along with industrialization of penicillin mechanically stirred bioreactor was developed,after that large quantity of bioreactors was invented for the sake of the development of mammal and plant cell cultivation,epiphyte cultivation and algae cultivation.Among these bioreactors mechanical stirred bioreactors and airlift bioreactors are very popular.Recent trends of studies on mechanically stirred bioreactors and airlift ones were reviewed.The focus is on the summarization and analysis of 11 kinds of novel bioreactors developed around the world.

Using the high efficient copper-adsorbing yeast strain Y17 as absorbing material, the major affect factors including pH, original concentration of Cu2+, cell biomass, adsorption time and temperature were examined, and then the absorbing sites of the Y17 was determined. The results showed that the solution pH was the most dominate factor which affected the biosorption of Cu2+, the other affecting factors were the ini- tial concentration of Cu2+, the cell biomass added, and adsorption time, respectively; the temperature had lit- tle effect on the rate of biosorption. The orthogonal experiment showed that the optimal absorption condition was as follow: the solution pH was 5.0, the absorption time was 40 min, the cell biomass of Y17 added was 5.0 g/L, and the concentration of Cu2+ was 8 mmol/L; the highest adsorbing rate was up to 82.7% at this condition. Based on the results of different pretreatments and the desorption of Cu2+, the cell wall of Y17 was identified as the main place occurring boisorption process, and the -NH2 group, -COOH group on the surface of the yeast cells played an important role on the boisorption process.

Objective To investigate the effects of rehabilitation training on the microenvironment for axon regeneration and the possible mechanisms promoting axon regeneration,reconstruction and functional compensation after spinal cord injury (SCI) in beagle dogs.Methods Fifteen beagles were divided into a sham operated group,an SCI model group and a rehabilitation training group.Spinal cord hemi-transection injury was carried out.From the 8th day after SCI,the rehabilitation training group was given treadmill training.All dogs were sacrificed 60 days postinjury and samples were harvested.Chondroitin sulphate proteoglycan (CSPG) expression of astroglial cells around the injured area was observed using an immunofluorescence technique.The expression of glial fibrillary acidic protein (GFAP) and CSPG protein in each group were semi-quantified by Western blot analysis.Axon regeneration was observed by silver staining.Motor function was assessed using modified Tarlov scores.Results In the rehabilitation training group,compared with the model group astroglial production of CSPG was reduced remarkably.Both CSPG expression and axon regeneration were enhanced and functional deficits improved.Conclusions Rehabilitation training can inhibit astroglial production of CSPG,improve the microenvironment for injured axon regeneration,and promote reconstruction and functional compensation after traumatic SCI.

Objective To investigate the growth inhibition and apoptosis induction effect of vitamin E succinate on MCF-7 human breast cancer cells and to analyze the modulation of Fas expression in this process. (Methods) Estrogen receptor positive MCF-7 human breast cancer cells were treated with VES for 12h, 24h and 48h. The concentrations of VES were 5?g/mL, 10?g/mL and 20?g/mL. The inhibitory effect was measured with MTT method and the cell cycle and cell surface Fas expression were analyzed with flow (cytometry). Fas protein level was detected by Western blotting assay. Results VES had significant inhibitory effect on the growth of MCF-7 human breast cancer cells and the effect was dependently related to time and dosage. The apoptotic rate rose from 1.2% to 11.2%,16.4%, 41.2%,after treated with VES for 48h at the concentrations of 5?g/mL,10?g/mL,20?g/mL respectively. Fas protein level and cell (surface) Fas expression in cancer cells increased after the administration of VES. Conclusions VES had (significant) growth inhibition and apoptosis induction effect on MCF-7 estrogen receptor positive breast cancer cells. The mechanism was related to Fas upregulation on the surface of cancer cells.

Hydrocarbons, Halogenated ; adverse effects ; chemistry ; Occupational Exposure ; prevention & control ; Occupational Health Services ; methods ; Solvents

Adult ; Benzene ; poisoning ; China ; Cross-Sectional Studies ; Female ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; statistics & numerical data ; Young Adult

Objective To investigate the effect of up-regulation of tetraspanin-5 (Tspan-5) expression on the metastatic ability of colorectal cancer (CRC) cells. Methods The coding sequence of Tspan-5 mRNA was amplified from total RNA of LoVo cells by RT-PCR and cloned into pEGFP-C1 to construct Tspan-5/pEGFP-C1,a eukaryotic expression vector. The expression of Tspan-5 in LST-R1 cells was up-regulated by gene tranfection. Western blotting was used to detect the expression level of Tspan-5/EGFP fusion protein,and laser scanning confocal microscopy (LSCM) was used to observe the distribution of Tspan-5/EGFP in LST-R1 cells. The changes in adhesion,migration and invasion ability of LST-R1 cells were determined by adhesion,migration and invasion experiment in vitro,respectively. Liver metastasis model of nude mice was used to test the changes in liver metastasis ability of LST-R1 cells in vivo. Results The Tspan-5/EGFP fusion protein could be detected by Western blotting in Tspan-5/pEGFP-C1 transfectants. LSCM showed that Tspan-5/EGFP protein located in cell membrane. Adhesion and migration assays showed that up-regulation of Tspan-5 expression level significantly promoted the adhesion and migration ability of LST-R1 cells on a series of extracellular matrix (ECM) components,including collagen IV,FN,LN and VN (P

Objective: To systematically investigate the prevalence of anxiety among healthcare professionals during the COVID-19 pandemic, so as to provide the development of evidence-based psychological interventions among healthcare professionals. Methods: The publications pertaining to the prevalence of anxiety among healthcare professionals during the COVID-19 pandemic were retrieved in national and international electronic databases from January 1, 2020 through November 30, 2021, including CNKI, Wanfang Data, VIP, SinoMed, PubMed and Web of Science. The quality of publications was evaluated using the United States Healthcare Research and Quality (AHRQ) quality assessment of included cross-sectional studies, and the pooled prevalence of anxiety was estimated among healthcare professionals using the software Open Meta Analyst version 3.0. The publication bias were evaluated with funnel plots and Begg rank correlation test. Results: Totally 598 publications were retrieved, and 36 eligible publications were enrolled in the final analysis, including 33 Chinese publications and 3 English publications. There were 5 high-quality, 29 moderate-quality and 2 low-quality publications. All investigations pertaining to the prevalence of anxiety among healthcare professionals were conducted in 2020. Totally 19 872 healthcare professionals were investigated, and the prevalence of anxiety was 28.8% (95%CI: 24.0%-33.6%). Subgroup analysis showed that the prevalence of anxiety was 31.9% (95%CI: 17.6%-46.2%) among healthcare professionals from western China, 29.6% (95%CI: (17.8%-41.4%) from central China, and 25.3% (95%CI: 20.2%-30.3%) from eastern China. The prevalence of anxiety was 4.9% (95%CI: 3.3%-6.4%) among male healthcare professionals and 22.9% (95%CI: 17.7%-28.0%) among male healthcare professionals, and the prevalence of anxiety was 21.6% (95%CI: 13.2%-29.9%) among nurses, 5.2% (95%CI: 2.8%-7.5%) among doctors and 4.8% (95%CI: 2.2%-7.4%) among other healthcare professionals. The prevalence of mild, moderate and severe anxiety was 18.6% (95%CI: 14.0%-23.2%), 5.5% (95%CI: 4.1%-6.8%) and 1.9% (95%CI: 1.3%-2.5%), respectively. No publication bias was detected as revealed by funnel plots and Begg rank correlation test, and stable meta-analysis results and heterogeneity test were observed. Conclusions The prevalence of anxiety is 28.8% among healthcare professionals during the COVID-19 pandemic, and mild anxiety is predominant. A high prevalence rate of anxiety is seen female healthcare professionals and nurses, who should be given a high priority and timely psychological interventions

Objective To investigate the expression of COX-2,MMP-2 and TIMP-2 ,the pathological fea-tures ,and their relationship in breast cancer. Methods The expressions of COX-2 ,MMP-2 and TIMP-2 were deter-mined by S-P immunohistochemical method on tissue chips,which containing 127 cases of breast carcinoma. Results The positive rates of COX-2,MMP-2 and TIMP-2 protein were 81.1 (103/127)% ,96.9(123/127)% and 60.6 (77/127) % respectively;The expression of COX-2 was positively related to auxiliary lymph node metastasis and TNM staging (P<0.01 and P<0.05, respectively), and inversely related to PR expression (P<0.05). Further-more,the expression of COX-2 was positively correlated with MMP-2 (r=0. 290 ,P<0.01). Conclusions The ex-pression of COX-2 might be closely related to the invasion and metastasis of breast cancer and has a close relation-ship with MMP-2. The levels of MMP-2 might be partly regulated by COX-2.