基于MEMS技术的WSS中“兔耳”现象的研究

在典型的微电子机械系统(Micro electro-mechanical systems,MEMS)型波长选择开关(Wavelength selective switch,WSS)中,一般使用双轴MEMS微镜来实现波长切换与光功率的衰减。文章从理论上研究了基于MEMS技术的WSS在实现衰减功能时"兔耳"现象产生的机理,并进行了实验验证。实验表明,用衍射理论的解释与实验结果能够较好地吻合。

现代汉语方言词的理据探讨应追溯本字——以“打虎的”“兔儿虎”“耳茄子”为例

现代汉语方言词的理据探讨,必须做好溯源的工作,以便古今贯通。从方言词典记录的方言词的意义入手,以音变现象为线索,对北京方言词中的"打虎的""兔儿虎""耳茄子"三词的本字进行追溯,可以明了它们的理据。

Preparation of High Titer Et Immune Serum by Low-Aged Animals

[Objective] The study aimed to establish an approach to high titer Et immune serum preparation by low-aged Japanese rabbits. [Method] Antigen of Et was prepared at first, Japanese rabbits were taken as immunized animal, and divided into two groups for experiments, one is two-month-old group （T group）, and another is six-month-old group （S group）. Japanese rabbits were continuous by immunized with low-dose by using auricular intravenous method, then immune sera were collected. Immune serum antibody titer was determined with micro-agglutination reaction method. E Resultl Agglutination reaction showed that the Et serum titer of S group is higher than that of T group in the first testing with the same dose. But in the second testing, the serum titer of the T group and and the S group was consistent, [Conclusien] The animals in the T group （Japanese rabbits） were fewer months old, and produced high titer antiserum was which consistent with the S group, which indicated that the method of preparing of high titer Et immune serum by low-aged Japanese rabbits was feasible.

Effect of ALA-PDT on the expressions of MMP-9, MMP-13 and TIMP-1 of hypertrophic scar model in rabbit ears

Objective: To investigate the effect of 5-aminolevulinic(ALA)-photodynamic therapy(PDT) on the expressions of MMP-9, MMP-13 and TIMP-1 of hypertrophic scar model in rabbit ears, and analyze the possible therapeutic mechanisms of ALA-PDT treatment to hypertrophic scars of rabbit ears. Methods: The experimental animals were randomly divided into normal control, negative control, high concentration of ALA-PDT, low concentration of ALA-PDT and PDT groups. The latter three groups received ALA-PDT treatment or PDT treatment once a week for 3 weeks. The specimens of the rabbits were collected respectively 1, 2 and 3 months after treatment to be used for RT-PCR and Western-blot test. Results: 1, 2 and 3 months after PDT treatment, the expressions of MMP-9 and MMP-13(including mRNA and protein) in hypertrophic scar tissues of three treatment groups were significantly higher than those of the negative control group(P<0.01), and the expression of TIMP-1 mRNA and protein of three treatment groups were significantly lower than that of the negative control group(P<0.01). There were also significant differences between high-concentration ALA-PDT treatment group and the low one(P<0.05). Conclusion: ALA-PDT is effective in treating hypertrophic scars of rabbit ears, and its possible therapeutic mechanisms are that ALA-PDT treatment generates oxidation activation effect to activate the activity of MMPs and induces the photoaging of fibroblasts of hypertrophic scar tissues of rabbit ears to inhibit the activity of TIMPs, which causes the up-regulation of MMPs and the down-regulation of TIMPs. Because of this, the degradation of collagen and ECM is accelerated and the formation of scars is suppressed.

Lung tissue flap repairs esophagus defection with an inner chitosan tube stent

AIM： TO repair the partial esophagus defect with a chitosan stent, a new esophageal prosthesis made of pulmonary tissue with vascular pedicie.METHODS： Fifteen Japanese big ear white rabbits were divided into experimental group （n = 10） and control group （n = 5）. Esophagus defect in rabbits of experimental group was repaired using lung tissue flap with a chitosan tube stent, gross and histological appearance was observed at week 2, 4 and 8 after operation, and barium sulphate X-ray screen was performed at week 10 after operation. Esophagus defect of rabbits in control group was repaired using lung tissue flap with no chitosan tube stent, gross and histological appearance was observed at week 2, 4 and 8 after operation, and barium sulphate X-ray screen was performed at week 10 after operation.RESULTS： In the experimental group, 6 rabbits survived for over two weeks, the lung tissue flap healed esophageal defection, and squamous metaplasia occurred on the surface of lung tissue flap. At week 10 after operation, barium sulphate examination found that barium was fluent through the esophagus with no stricture or back stream, the creeping was good. In the control group, 4 rabbits survived for two weeks, the lung tissue flap healed esophageal defection with fibrous tissue hyperplasia, barium sulphate examination found that barium was fluent through the esophagus with a slight stricture or back stream, and the creeping was not good at week 10 after operation.CONCLUSION： Esophagus defect can be repaired using lung tissue flap with an inner chitosan tube stent.

Endostatin inhibits hypertrophic scarring in a rabbit ear model

Objective： The present study was designed to use an in vivo rabbit ear scar model to investigate the efficacy of systemic administration of endostatin in inhibiting scar formation. Methods： Eight male New Zealand white rabbits were randomly assigned to two groups. Scar model was established by making six full skin defect wounds in each ear. For the intervention group, intraperitoneal injection of endostatin was performed each day after the wound healed （about 15 d post wounding）. For the control group, equal volume of saline was injected. Thickness of scars in each group was measured by sliding caliper and the scar microcirculatory perfusion was assessed by laser Doppler flowmetry on Days 15, 21, 28, and 35 post wounding. Rabbits were euthanatized and their scars were harvested for histological and proteomic analyses on Day 35 post wounding. Results： Macroscopically, scars of the control group were thicker than those of the intervention group. Significant differences between the two groups were observed on Days 21 and 35 （p〈0.05）. Scar thickness, measured by scar elevation index （SEI） at Day 35 post wounding, was significantly reduced in the intervention group （1.09±0.19） compared with the controls （1.36±0.28）. Microvessel density （MVD） observed in the intervention group （1.73±0.94） was significantly lower than that of the control group （5.63±1.78） on Day 35. The distribution of collagen fibers in scars treated with endostatin was relatively regular, while collagen fibers in untreated controls were thicker and showed disordered alignment. Western blot analysis showed that the expressions of type I collagen and Bcl-2 were depressed by injection of endostatin. Conclusions： Our results from the rabbit ear hypertrophic scar model indicate that systemic application of endostatin could inhibit local hypertrophic scar formation, possibly through reducing scar vascularization and angiogenesis. Our results indicated that endostatin may promote the apoptosis of endothelial cells and block their release of platelet-dedved growth factor （PDGF） and fibroblast growth factor （FGF）, thereby controlling collagen production by fibroblasts. Blood vessel-targeted treatment may be a promising strategy for scar therapy.