宝鼎矿区花山煤矿多诱因大范围火区治理关键技术

为治理花山矿4238工作面极复杂+1 030 m水平四采大范围蔓延隐蔽阴燃状态火区,以主动灭火与分区隔离治火相结合为基本思路,先后采取远距离封闭后缩封、无机材料充填、液态二氧化碳降温冷却、注氮惰化、施工措施巷灌注粉煤灰浆、阴燃火区外围巷道充填等综合灭火技术进行治理。结果表明:4238工作面火区火已熄灭;外围阴燃火区经高强度、长时间治理,火已逐渐熄灭,CO气体体积分数控制在1×10-5以下,目前,火区治理处于收尾阶段。

Polyploidy induction by hydrostatic pressure shock and embryo development of sea cucumber Apostichopus japonicus

The manipulation of the chromosome set for commercially valuable marine animals is important for enhancing aquacultural production. In this study, triploid and tetraploid sea cucumber Apostichopus japonicus were induced by hydrostatic pressure shock, and the conditions of appropriate induction were tested with different starting times, and hydrostatic pressure intensities and durations. The highest rate of triploid induction reached 20% and that of tetraploid was 60%. In consideration of the survival rate and hatch rate, the appropriate treatment for triploid was 55 Mpa of hydrostatic pressure for 5 rain at 55 min after fertilization （a.f.）, while for tetraploid it was 60 Mpa for 5 rain at 61 min a.f. The triploid of the sea cucumber could survive through the pelagic larval stage and attachment stage, and develop like the control group of the experiment. The tetraploid, however, could not survive the attachment stage.

Interaction of major genes predisposing to hepatocellular carcinoma with genes encoding signal transduction pathways influences tumor phenotype and prognosis

Studies on rodents and humans demonstrate an inherited predisposition to hepatocellular carcinoma （HCC）. Analysis of the molecular alterations involved in the acquisition of a phenotype resistant or susceptible to hepatocarcinogenesis showed a deregulation of G1 and S phases in HCC of genetically susceptible F344 rats and a G1-S block in lesions of resistant Brown norway （BN） rats. Unrestrained extracellular signal-regulated kinase （ERK） activity linked to proteasomal degradation of dual-specificity phosphatase 1 （DUSP1）, a specific ERK inhibitor, by the CKS1-SKP2 ubiquitin ligase complex occurs in more aggressive HCC of F344 rats and humans. This mechanism is less active in HCC of BN rats and human HCC with better prognosis. Upregulation of iNos cross-talk with IKK/NF-KB and RAS/ERK pathways occurs in rodent liver lesions at higher levels in the most aggressive models represented by HCC of F344 rats and c-Myc-TGF-α transgenic mice. iNOS, IKK/NF-κB, and RAS/ERK upregulation is highest in human HCC with a poorer prognosis and positively correlates with tumor proliferation, genomic instability and microvascularization, and negatively with apoptosis. Thus, cell cycle regulation and the activity of signal transduction pathways seem to be modulated by HCC modifier genes, and differences in their efficiency influence the susceptibility to hepatocarcinogenesis and probably the prognosis of human HCC.

Generation of Transgene-free Induced Pluripotent Stem Cells with Non-viral Methods

Induced pluripotent stem （iPS） cells were originally generated from mouse fibroblasts by enforced expression of Yamanaka factors （Oct3/4, Sox2, Klf4, and c-Myc）. The technique was quickly re- produced with human fibroblasts or mesenchymal stem cells. Although having been showed therapeutic po- tential in animal models of sickle ceil anemia and Parkinson＇s disease, iPS cells generated by viral methods do not suit all the clinical applications. Various non-viral methods have appeared in recent years for application of iPS cells in cell transplantation therapy. These methods mainly include DNA vector-based approaches, transfection of mRNA, and transduction of reprogramming proteins. This review summarized these non-viral methods and compare the advantages, disadvantages, efficiency, and safety of these methods.

Ursolic acid sensitized colon cancer cells to chemotherapy under hypoxia by inhibiting MDR1 through HIF-1α

Objective： To explore the efficacy of ursolic acid in sensitizing colon cancer cells to chemotherapy under hypoxia and its underlying mechanisms. Methods： Three colon cancer cell lines （RKO, LoVo, and SW480） were used as in vitro models. 5-Fluorouracil （5-FU） and oxaliplatin were used as chemotherapeutic drugs. Cell viability and apoptosis were tested to evaluate the sensitivity of colon cancer cells to chemotherapy. The transcription and ex- pression levels of hypoxia-inducible factor-1α （HIF-1α）, multidrug resistance gene 1 （MDR1）, and vascular endothelial growth factors （VEGF） were assessed by quantitative real-time polymerase chain reaction （qRT-PCR） and im- munoblotting. Cycloheximide and MG132 were used to inhibit protein synthesis and degradation, respectively. In vitro tube formation assay was used to evaluate angiogenesis. Results： We demonstrated the chemosensitizing effects of ursolic acid with 5-FU and oxaliplatin in three colon cancer cell lines under hypoxia. This effect was correlated to its inhibition of MDR1 through HIF-la. Moreover, ursolic acid was capable of inhibiting HIF-1α accumulation with little effects on its constitutional expression in normoxia. In addition, ursolic acid also down-regulated VEGF and inhibited tumor angiogenesis. Conclusions： Ursolic acid exerted chemosensitizing effects in colon cancer cells under hypoxia by inhibiting HIF-la accumulation and the subsequent expression of the MDR1 and VEGF.