Experimental study on the freezing process of water droplets for ice air jet technology.

Ice air jet technology is one non-destructive, residue-free and environmentally friendly machining process. It is an efficient method to form ice particles by atomizing water droplets in ultra-low temperature environment. The freezing characteristics of water droplets in cryogenic gas and liquid nitrogen environment are visually analyzed, and the effects of droplet volume, ambient temperature are also studied. The results show that when water droplets freeze in a cryogenic gas environment, four distinct stages are observed, namely pre-cooling stage, recalescence stage, solidification stage, and deep cooling stage. However, when water droplets freeze in liquid nitrogen, the recalescence stage cannot be observed. For a 5 µl water droplet, it takes 68 s for water droplets to freeze into ice particles at - 20.36 °C, while it takes only 1.7 s in liquid nitrogen. During the freezing process, the water droplets form an ice shell outside and freeze inwardly. Ice particles may break up due to differences in solubility and density. With the increase of volume the time spent on pre-cooling stage and freezing stage both increases. For the large latent heat of water phase transformation, the solidification stage time is greatly affected by the volume of water droplets. When the ambient temperature drops from - 10.67 °C to - 24.68 °C, the freezing time of 5 µl water droplets decreases by 45.5%, indicating that the ambient temperature has a great influence on the freezing time. The results of the study can significantly contribute to the development of ice air jet technology.

Effect of Berberine on TNF-α-induced VEGF Expression via NF-κB Signaling Pathway / 华中科技大学学报(医学版)

Objective To examine the effect of berberine on tumor necrosis factor-α(TNF-α)-induced VEGF expression and the possible mechanism.Methods There were two sessions in this study.In the first session,HepG2 cells were treated with 10 ng/mL TNF-αfor 0,12,24 and 48 h,respectively.In the second session,HepG2 cells were pre-incubated with 0,10,25 and 50μmol/L berberine for 24 h,respectively,and then treated with 10 ng/mL TNF-αfor 24 h.The effect of berberine on the prolif-eration of HepG2 cells was assayed by MTT.The level of VEGF mRNA was detected by real-time PCR,and the expression lev-els of VEGF,IκBαand NF-κB p65 proteins by Western blot.The activity of NF-κB was measured by ELISA.Results Berberine could dose-dependently inhibit the growth of HepG2 cells.TNF-αcould increase the mRNA and protein expression levels of VEGF in HepG2 cells in a time-dependent manner.Berberine could significantly dose-dependently down-regulate the TNF-α-in-duced VEGF expression at mRNA and protein levels.TNF-αsignificantly decreased the expression of IκBαand increased the ex-pression of NF-κB p65 and the activity of NF-κB in a time-dependent manner,which could be dose-dependently abrogated by pretreatment with berberine.Conclusion Berberine inhibits TNF-α-induced VEGF expression via NF-κB signaling pathway.

Establishment of induction and culture system for hairy roots of Psammosilene tunicoides / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a culture system for Psammosilene tunicoides hairy roots, and provide technological aid for the large-scale production of P. tunicoides material.</p><p><b>METHOD</b>The young leaves and stem segments of sterile plantlets were infected with ACCC10060 strain, and subsequently a culture system suitable for hairy roots growth was further established.</p><p><b>RESULT</b>When explants were co-cultured with ACCC10060 (A600 0.8) on B5 media containing 20 mg x L(-1) Acetosyringo (AS) for 48 h, the hairy roots could be successfully induced, and it could achieve a higher induction rate using young leaves as explants than that of stem segments. The transfected hairy roots possessed the ability of kanamycin resistance and growth on hormone-free media, and synthesis of opines. All above results demonstrated that the present hairy roots originated in the infection of P. tunicoides tissues by ACCC10060 strains. After 35 d culture in liquid hormone-free MS (1/2 strength), the biomass of hairy roots increased 14.11 times (fresh weight) and 8. 39 times (dry weight), respectively, and the content of total saponins in hairy roots reached to 0.857% (DW), by contrast, it's only 0.388% and 0.217% in callus and seedlings respectively.</p><p><b>CONCLUSION</b>Establishment of hairy roots culture of P. tunicoides provided a foundation for industrial production of active components from P. tunicoides culture.</p>

Expression of filamin A in invasive breast carcinoma and its significance / 肿瘤

Objective:To study the relationship between the expression of filamin A (FLNa) and clinical pathological features in invasive breast carcinoma. Methods:The expression of FLNa was measured by immunohistochemistry and flow cytometry in 46 cases of invasive breast carcinoma. Results:The expression level of FLNa was increased in poorly differentiated invasive breast carcinoma. There were significant differences between well-moderately differentiated and poorly differentiated groups (P<0.05). The expression level of FLNa in invasive breast carcinoma with lymph node metastasis was higher than that in non-metastasis group (P<0.05). Conclusion:The level of FLNa expression correlated with invasion and metastasis of invasive breast carcinoma. FLNa can be used as an assistant marker for prediction of breast carcinoma prognosis and has the potential to be a new target for cilinical therapy.