For multiphase steel, an efficient and accurate quantitative analysis of constituent phases is critical in understanding the mechanical mechanism and optimising its properties. A method based on image digitisation and the concept of categorised linear interception has been proposed to study the amount of retained austenite (RA) residing in different phases in quenching and partitioning treated multiphase steel. It was found that RA at different locations transformed in different strain stages due to considerable influence from the surrounding phases, and the stability of each type of RA was estimated according to the above mentioned method. The proposed multistage transformation was proved to be more accurate than a single stage stability model.

We studied the relationship between locations of retained austenite (RA) and the deformation behaviors of quenching and partitioning treated steels. By using a variety of quantitative characterization techniques and comparing ferrite and martensite dual-phase counterparts, we confirmed that the stability of RA within different matrix phases is largely dependent on the plastic incompatibility between ferrite and martensite phases. If there exists significant difference in strength between ferrite and martensite, the transformation of RA is discontinuous. The RA inside ferrite and martensite transforms under low and high strain, respectively. As a result, deformation behaviors of the matrix phases, especially the ferrite phase at low strain, can be substantially affected by the change of RA. Our analysis offers insight into the interactions among different phases, the stability of RA, and the strain hardening behavior of multi-phase steels.

The output power of renewable energy power plants (wind farms and solar power plants) fluctuates. In order to smooth power fluctuation or tracking power generation schedule, energy storage devices are often configured in power system. In this paper, charging and discharging characteristics of battery is analyzed as representative of energy storage devices and an energy storage system model is established. For different operation modes, an optimal configuration model is studied under two different control objectives, which mean tracking power generation schedule and smoothing the output fluctuations. The optimization objective is the minimization of energy storage devices investment costs, and the decision variables are the rated power and rated capacity of energy storage devices. For a practical case, Matlab is used to calculate the optimal solution.

OBJECTIVE:To investigate the effect of simulated microgravity on erythroid differentiation of K562 cells and explore the possible mechanism.METHODS:The fourth generation rotating cell culture system was used to generate the simulated microgravity environment. Benzidine staining was used to evaluate the cell inhibition rate, and real-time quantitative PCR (qRT-PCR) was used to detect GATA-1, GATA-2, Ets-1, F-actin, β-Tubulin and vimentin mRNA expressions. The changes of cytoskeleton were observed by fluorescence microscopy, and Western blotting was employed to assay F-actin, β-tubulin and vimentin protein expression levels.RESULTS:Benzidine staining showed that simulated microgravity inhibited erythroid differentiation of K562 cells. K562 cells treated with Hemin presented with increased mRNA expression of GATA-1 and reduced GATA-2 and Ets-1 mRNA expressions. Simulated microgravity treatment of the cells resulted in down-regulated GATA-1, F-actin, β-tubulin and vimentin mRNA expressions and up-regulated mRNA expressions of GATA-2 and Ets-1, and reduced F-actin, β-tubulin and vimentin protein expressions. Exposure to simulated microgravity caused decreased fluorescence intensities of cytoskeletal filament F-actin, β-tubulin and vimentin in the cells.CONCLUSION:Simulated microgravity inhibits erythroid differentiation of K562 cells possibly by causing cytoskeleton damages to result in down-regulation of GATA-1 and up-regulation of GATA-2 and Ets-1 expressions.

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We studied the ability of Ag/nano-TiO2 to inhibit Staphylococcus aureus growth on silicone elastomer material. Ag/nano-TiO2 silicone elastomer was prepared with different concentrations of 0%, 2%, 4%, 6%, 8%, 10%. The antibacterial efficacy of Ag/nano-TiO2 silicone elastomer was determined by the inhibition zone method and the impregnated culture method. The antibacterial timeliness of Ag/nano-TiO2 silicone elastomer was tested by direct contact method. The samples were kept through thermal aging process in an accelerated aging chamber. The effect of concentrations of Ag/nano-TiO2 was insignificant (P < 0.05). There was significant difference between the Ag/nano-TiO2 silicone elastomer and the blank silicone elastomer (P < 0.5). There was also significant difference among specimen groups whose aging periods were 50 degrees C, 100 degrees C, 150 degrees C, 200 degrees C for 87 h (P < 0.5). The silicone elastomer with different concentrations of Ag/nano-TiO2 effectively inhibits Staphylococcus aureus growth.

Objective To observe the in vivo gene expression profile of the recombinant adenoassociated-2 virus mediated human GM-CSF, mouse GM-CSF (rAAV-2-hGM-CSF, rAAV-2-mGM-CSE )vector modified bone marrow mesenchymal stem cell (BMSC). Methods We transduced the BMSC by rAAV-2-hGM-CSF, rAAV-2-mGM-CSF at the condition which have acquired before respectively, then transfused the in vitro gene modified BMSC after 12 days proliferation in vitro to 6 weeks old nude mice through tail vein,while the BMSC transfused in control group hadn' t been gene modified. 2, 4, 6, 8 weeks after transfusion, count the total white blood cells and detect the hGM-CSF, mGM-CSF concentration in nude mice serum at that time point. Results Nude mice serum hGM-CSF levels were 23.77, 25.32, 19.77, 15.25 ng/L at 2, 4, 6, 8 weeks after transfusion compare to 36.25 ng/L, the in vitro level before transfusion; mGM-CSF levels were 34.96, 34.84, 35.50, 32.93 ng/L at 2, 4, 6, 8 weeks after transfusion compare to 25.14 ng/L, the in vitro level before transfusion; at the same time point the nude mice serum mGM-CSF levels were 17.34,17.44, 14.68, 16.85 ng/L in control group, rAAV-2-mGM-CSF transduced BMSC made the nude mice white blood cell count increased, but no changes in nude mice white blood cell count at rAAV-2-hGM-CSFtransduced BMSC and control group. Conclusion BMSC as a gene therapy vehicle, it can be gene modified in vitro, then the gene modified BMSC could let the therapeutic gene to have therapeutic effects in vivo.

The anti-tumor drug, harringtonine (HT), has been extensively used with satisfactory results in the treatment of acute or chronic myeloid leukemia. Previous studies have shown that the anti-tumor activity of the drug is related to induced apoptosis of tumor cells, but the molecular mechanism still remains unclear. The main purpose of this research was to analyze the protein profiles formed during HT-induced apoptosis in K562 cells and to screen the apoptotic-related proteins.

BACKGROUND & OBJECTIVE Chronic myelogenous leukemia (CML) is a malignant hematological disease.CML patients are commonly treated with hematopoietic stem cells transplantation (HSCT). This study was designed to evaluate the effect of HSCT on the patients with CML. METHODS Forty-four patients with CML were treated by HSCT, including 8 cases treated with purging autologous transplantation, 30 cases with related donor allogeneic HSCT (allo-HSCT), and 6 cases with unrelated donor allo-HSCT. The conditioning regimen was TBI (total-body irradiation)+CY (CTX) protocol in 31 patients and modified BuCY (hydroxyurea, busulfan, Ara-C, CTX) protocal in 12 patients, and MACC (Melphalan, Ara-C, CTX and CCNU) protocol in one patient. CsA (cyclosporine) and MTX were used in the patients with related donor allo-HSCT, and CsA and MTX added to mycophenolate mofetil (MMF) and antithymocyte globulin (ATG) were used in the patients with unrelated donor all-HSCT for graft versus host disease (GVHD) prophylaxis. Otherwise, CsA was only used in the patients with accelerated phase(AP) and blast crisis(BC) for GVHD prophylaxis. Kaplan-Meier survival analysis model was used to estimate the overall survival (OS) and the disease-free survival (DSF) at 5 years after transplantation. RESULTS Eight patients with autologous transplantation, except one case died of transplantation-related-complication, obtained part or complete cytogenetic remission within 3 months after transplantation. One patient, who was BC and obtained complete remission (CR) in hematology before transplantation,obtained complete molecular remission for 81 months after autologous transplantation. All patients obtained CR, except one patient died of hepatic veno-occlusive disease (VOD) and one case did not obtained CR, in 36 patients with allo-HSCT after transplantation. The incidence of infection and VOD during transplantation were 38.6% and 9.1%, respectively. The incidences of hemorrhagic cystitis (HC) and cytomegalovirus (CMV) pneumonia after transplantation were 15.9% and 11.4%, respectively. VOD, HC, and CMV pneumonia did not occur in the patients with autologous transplantation. The incidence of acute GVHD in the patients with related and unrelated donor transplantation were 40.0% and 33.3%, respectively. The incidence of chronic GVHD was 43.4% in the patients with related donor transplantation. The rates of transplant-related mortality (TRM) in the patients with autologous and allogeneic transplantation were 12.5% and 16.7%, respectively. The rates of relapse in patients with autologous and related donor transplantation were 37.5% and 13.3%, respectively. The DFSs at 5 years in patients with autologous and related donor transplantation after transplantation were 18.7% and 53.7%, respectively. The DFS at 5 years in patients with CP (chronic phase) or AP and BC before transplantation were 66.4% and 26.7%, respectively. CONCLUSION all-HSCT shows higher clinical cure rate to CML patients with CP. CsA+MTX+MMF+ATG protocol is more effective for acute GVHD prophylaxis and can decrease the incidence and severity of acute GVHD in patients with unrelated donor transplantation. Autologous transplantation with bone marrow purged can prolong the survival time and a few patients may be cured with autologous transplantation in CML.

OBJECTIVE:To investigate the material foundation of the fusion of bcr and abl genes, and to explore the pathogenesis of chronic myeloid leukemia.METHODS:By FISH combined with laser confocal scanning microscopy, the three-dimension (3D) distribution of bcr and abl genes in the interphase nuclei of normal and irradiated IM-9 cells was studied in each cell cycle phases.RESULTS:abl and bcr genes distributed non-randomly in the interphase nuclei of IM-9 cells. abl gene preferably located at the outer layer and bcr near the core of the nucleus. The two genes were drawn near each other most in G(0) phase. The relative distance between the homologous genes was greater at proliferation phase than at quiescence phase. After irradiation, the relative distances from the two genes to the core and between the two genes were shortened, with the shortest distance between the two genes in S phase.CONCLUSION:Irradiation could change the 3D-distribution of abl and bcr genes in the interphase nuclei of IM-9 cell and accelerate them to draw near each other.

The aim of this study was to construct recombinant mDHFR-GFP/AAV vector containing mutated dihydrofolate reductase (mDHFR) and green fluorescent protein (GFP) fusion genes and its expression in NIH3T3 cells, to investigate the resistance of the cells to methotrexate. Amplified cDNA of mDHFR and GFP segmented from their plasmid separately were linked by PCR with the aminoacetic acid linker. The fusion gene was inserted into T vector, and after enzyme cutting the fusion gene fragment was inserted into AAV vector, then packaging the vector into recombined AAV and infected NIH3T3 cells. Expression of gene fusion was observed by PCR, fluorescent microscopy and flow cytometry. mDHFR and GFP cDNA were found in NIH3T3 genomic DNA, the GFP expression rate was about 25%, and resistance of the transferred cells to MTX was increased markedly. The results showed that AAV vector can transfer mDHFR and GFP fusion gene into NIH3T3 cells and increase resistance to MTX in gene modified cells. This data provided a basis for application of mDHFR and AAV vector in gene therapy.

OBJECTIVE:To understand the differential gene expression profiles between bone marrow cells and mobilized peripheral blood CD34(+) cells. METHODS:Suppression subtractive hybridization (SSH) was employed to identify the genes differentially expressed in bone marrow and mobilized peripheral blood CD34(+) cells obtained from a healthy donor. RESULTS:Twenty-one differentially expressed genes were identified that could be categorized into S-phase- or G(2)-M cell cycle-related genes and CCAAT/enhancer binding protein (C/EBP) transcription factor family. The genes highly expressed in bone marrow CD34(+) cells indicated low expression of their counterparts as SSH demands strict paired comparison between the 2 types of CD34(+) cells of different origins. CONCLUSION:CD34(+) cells derived from bone marrow are featured by more active proliferation than are those from mobilized peripheral blood.

OBJECTIVE:To elucidate the mechanism by which harringtonine (HT) induces apoptosis in K562 cell line.METHODS:By means of cell morphology, DNA gel electrophoresis and flow cytometry, we explored the action of HT on K562 cell line. Further study of the changes in bcr/abl gene expression was conducted using reverse transcriptase (RT)-PCR.RESULTS:HT induced apoptosis of K562 cells at the concentrations ranging from 0.01 to 100 microg/ml, exhibiting dose- and time-dependent increase in apoptotic ratios of the cells subjected to the treatment courses of 12 to 60 h. RT-PCR showed that bcr/abl gene expression was down-regulated after K562 cells had been treated with 10 microg/ml HT.CONCLUSION:Low concentration of HT can induce apoptosis in K562 cell line, possibly through the down-regulation of bcr/abl gene expression.

OBJECTIVE:To construct the recombinant plasmid FasAD-pTYB2 for the fusion expression of Fas activation domain (FasAD).METHODS:FasAD cDNA was cloned by semi-nested reverse transcriptase-polymerase chain reaction (RT-PCR), and then inserted into the universal vector of pGEM-T for the identification of its DNA sequence. The target DNA fragment was inserted into the prokaryote vector pTYB2 that expressed intein to construct the plasmid recombinant FasAD-pTYB2 which was induced by isopropylthio-beta-D-galactoside for the expression of the fusion protein.RESULTS:DNA sequence analysis confirmed sequence of FasAD cDNA previously cloned, and expression of the fusion protein by the recombinant plasmid was achieved, the product recognizable by rabbit anti-human Fas polyclonal antibody as demonstrated by Western blotting analysis.CONCLUSION:The recombinant plasmid FasAD-pTYB2 constructed in this study is capable of expressing the fusion protein of FasAD and intein, which may be significant for further study of the epitope and function of Fas antigen.