Ultrafast temporal-spatial dynamics of amorphous-to-crystalline phase transition in Ge2Sb2Te5 thin film triggered by multiple femtosecond laser pulses irradiation

Studies have shown that the crystallization phase state of Ge₂Sb₂Te₅ (GST) can be reversibly modulated by femtosecond (fs) laser multiple pulses, which have excellent applications in reconfigurable multi-level operation fields. In this study, the temporal-spatial crystalline evolution dynamics of amorphous GST film is investigated during two fs laser pulses excitation through a pump-probe shadowgraph imaging technique. A quasi-amorphous phase state, which is different from that in the initial as-deposited amorphous GST, is emerged through the first fs laser pulse excitation with a pulse energy lower than crystallization threshold. The experimental results reveal that a crystallization enhancement effect can be induced through the second pulse excitation based on this quasi-amorphous surface structure. The stimulative cluster generated in the quasi-amorphous reduces the amorphous-to-crystalline phase transition threshold for the second fs laser pulse irradiation. The spatially-resolved phase-transition threshold extension effect in a horizontal direction is proposed with the increasing pulse number to summarize the mechanism of the crystallization enhancement effect. The specific-grain-appearance (coarse grains and fine grains representing different phase transition approach) distributed area induced by single and double fs laser pulses irradiation are experimentally demonstrated corresponding to threshold extension theory.

[Clinical efficacy of burning mouth syndrome treated by livial]

OBJECTIVE

To observe the clinical efficacy of livial on postmenopause women with burning mouth syndrome.

METHODS

Fifty six postmenopause women with burning mouth syndrome were randomly divided into two groups, 26 patients were treated with livial as the treatment group, 30 patients were treated with oryzanol and vitamin E as the control. To evaluate the effect, all the patients were observed in 3-6 months after therapy.

RESULTS

The result showed that the total effective rate of the treatment group was 84.62% after 3 months, 88.46% after 6 months, and significantly higher than that in the control(P < 0.005).

CONCLUSION

It is indicated that livial is safer and more effective than nylestriol in treatment with burning mouth syndrome.

Preparation and characterization of mabs against different epitopes of CD226 (PTA1)

Recently the platelet and T-cell activation antigen 1 (PTA1) was assigned as CD226 at the 7th Conference and Workshop on Human Leukocyte Differentiation antigens (HLDA). PTA1 is mainly expressed on activated T cells, natural killer (NK) cells, platelets and stimulated endotheliocytes, and involved in the differentiation of cytotoxic T lymphocytes (CTL) and NK, as well as platelet activation and aggregation. We raised hybridomas secreting monoclonal antibodies (MAbs) to PTA1 by using the natural PTA1 as immunogen, which was purified from platelets via affinity chromatography. These MAbs, designated FMU1, FMU2, FMU3, FMU4, FMU5, FMU6 and FMU7, could recognize PTA1 cDNA transfected COS7 cells detected by flow cytometry (FCM), and also react with both natural PTA1 and PTA1/Ig fusion protein in indirect enzyme-linked immunoadsorbent assay (ELISA). The biosensor epitope mapping assay showed that the seven MAbs, together with previous PTA1-specific MAbs Leo A1 and New E1, could bind seven distinct epitopes of PTA1, respectively. The panel of MAbs might be new powerful tools to study the structure-function relationship of PTA1 molecule, and to search for the ligand of PTA1.

[A morphometric study on the microvessel in oral submucous fibrosis]

To investigate the pathologic change of the microvessel in oral submucous fibrosis(OSF), the pathologic buccal tissues of 27 patients with OSF were studied by using immunochemical method. Microvessel quantity(MVQ), quantity density(QD), microvessel area(MVA) and area density(AD) were determined by means of computer-aided image analysis system. The results showed the increase in MVQ and QD in the early stage and the decrease in MVQ, QD, MVA and AD in the middle stage and the late stage. The authors concluded that presence of microvessel hyperplasia occurred in the early stage of OSF.