均匀化位相的常规非稳腔的分析与实验

对常规非稳腔的输出镜面进行改造 ,在原来不透光的中央区域引入增透膜 ,使之能部分透过 ,使输出耦合能的比例得到提高 ;同时加敷适当的位相膜 ,使中央区与环带区波面位相拉平些。着重报导了均匀化相位常规非稳腔的系列实验和分析 ,从而使常规非稳腔的环带输出引起的中央不透明区与外环带输出波面的位相突变得到改善 ,克服了远场能量分布出现较严重离散的问题 ,使远场中央亮斑能量更集中。

3相及4相性Ⅰ度房室传导阻滞并存1例

3相和4相性传导阻滞是2种相反的频率依赖性传导阻滞,前者依赖于心率增快,后者依赖于心率减慢。阻滞的程度多为Ⅱ度,Ⅰ度者少见。本例非但在同次分别记录3相及4相阻滞,而且均为Ⅰ度,特报道如下: 患者女,61岁。可疑冠心病。附图为动态心电图。同步记录模拟V5及aVF导联。第一段为19:13记录,由下部缩薇记录可知窦性心律突然减慢。

建筑室内S带电磁污染控制板材的薄形化研究

本文报道了基于k／4型电磁波吸收原理，通过理论设计和模拟分析，以石膏板为介电材料，采用住相调制膜设计制备吸波体，成功实现了电磁波吸收体的薄化。研究表明，多边形及圆环形位相调制膜结构都可以实现吸收体的薄化和吸收宽化，但多边形效果更好。实验表明，环宽度15mm，间距为10mm的正六边形三环结构膜可以实现在2．2GHz附近，达到-25dB吸收，并呈现更大宽化，整体-10dB带宽达到70％且可减少介电层厚度15％。新材料可用于室内电磁环境的改善和污染控制。

Low grade gastric mucosa associated lymphoid tissue lymphoma:Treatment strategies based on 10 year follow-up

AIM:To deduce strategic guidelines of gastric mucosa associated lymphoid tissue lymphoma (MALTOMA) by evaluating the long-term outcome of patients in respect to various treatment modalities. METHODS:A total of 55 patients with MALTOMA from May 1992 to August 2002 were retrospectively reviewed. RESULTS:Complete remission was obtained in 24 (82.8%) of 29 patients treated with anti Helicobacter pylori (Hpylori) regimen only.The duration to reach complete remission was 12 months (85 percentile,2-33 months).Five patients showed complete remission with radiation therapy (26-86 months).Two of them were Hpyloritreatment failure cases. CONCLUSION:Hpylorieradication is an effective primary treatment option for low grade MALTOMA and radiation therapy could be considered in patients with no evidence of Hpyloriinfection or who do not respond to Hpylorieradication therapy 12 months after successful eradication.

Circadian variation in expression of G_1 phase cyclins D_1 and E and cyclin-dependent kinase inhibitors p16 and p21 in human bowel mucosa

AIM： To evaluate whether the cellular proliferation rate in the large bowel epithelial cells is characterized by circadian rhythm. METHODS： Between January 2003 and December 2004, twenty patients who were diagnosed as suffering from primary, resectable, non-metastatic adenocarcinoma of the lower rectum, infiltrating the sphincter mechanism, underwent abdominoperineal resection, total mesorectal excision and permanent left iliac colostomy. In formalinfixed and paraffin-embedded biopsy specimens obtained from the colostomy mucosa every six hours （00：00, 06：00, 12：00, 18：00 and 24：00）, we studied the expression of G1 phase cyclins （D1 and E） as well as the expression of the G1 phase cyclin-dependent kinase （CDK） inhibitors p16 and p21 as indicators of cell cycle progres- sion in colonic epithelial cells using immunohistochemical methods. RESULTS： The expression of both cyclins showed a similar circadian fashion obtaining their lowest and highest values at 00：00 and 18：00, respectively （P〈 0.001）. A circadian rhythm in the expression of CDK inhibitor proteins p16 and p21 was also observed, with the lowest levels obtained at 12：00 and 18：00 （P〈0.001）, respectively. When the complexes cyclins D1-p21 and E-p21 were examined, the expression of the cyclins was adversely correlated to the p21 expression throughout the day. When the complexes the cyclins D1-p16 and E-p16 were examined, high levels of p16 expression were correlated to low levels of cyclin expression at 00：00, 06：00 and 24：00. Meanwhile, the highest expression levels of both cyclins were correlated to high levels of p16 expression at 18：00. CONCLUSION： Colonic epithelial cells seem to enter the G1 phase of the cell cycle during afternoon （between 12：00 and 18：00） with the highest rates obtained at 18：00. From a clinical point of view, the present results suggest that G1-phase specific anticancer therapies in afternoon might maximize their anti-tumor effect while minimizing toxicity.

Influence of relative positions between RF coil and crucible on sapphire crystals by edge-defined film-fed growth(EFG) technique

To obtain the stable temperature field required for growing sapphire crystals, the influence of relative positions between RF coil and crucible on the performances of sapphires produced by edge-defined film-fed growth（EFG） technique was investigated. For comparison, the crucible was located at the top（case A） and the middle（case B） of the RF coil, respectively. Furthermore, the lattice integrities were studied by the double-crystal X-ray diffraction, and the dislocations were observed under the optical microscope and atomic force microscope after corroding in molten KOH at 390 ℃. The crystals in case B exhibit better lattice integrity with smaller full width at half maximum of 29.13 rad·s, while the value in case A is 45.17 rad·s. The morphologies of dislocation etch pits in both cases show typical triangular symmetry with smooth surfaces. However, the dislocation density of 2.8×104 cm-2 in case B is only half of that in case A, and the distribution is more uniform, compared to the U-shaper in case A.

Effects of allocryptopine on outward potassium current and slow delayed rectifier potassium current in rabbit myocardium

Objective Allocryptopine （ALL） is an effective alkaloid of Corydalis decumbens （Thunb.） Pers. Papaveraceae and has proved to be an- ti-arrhythmic. The purpose of our study is to investigate the effects of ALL on transmural repolarizing ionic ingredients of outward potassium current （Ito） and slow delayed rectifier potassium current （IKs）. Methods The monophasic action potential （MAP） technique was used to record the MAP duration of the epicardium （Epi）, myocardium （M） and endocardium （Endo） of the rabbit heart and the whole cell patch clamp was used to record/to and IKs in cardiomyocytes of Epi, M and Endo layers that were isolated from rabbit ventricles. Results The effects of ALL on MAP of Epi, M and Endo layers were disequilibrium. ALL could effectively reduce the transmural dispersion of repolarization （TDR） in rabbit transmural ventricular wall. ALL decreased the current densities of/to and IKs in a voltage and concentration dependent way and narrowed the repolarizing differences among three layers. The analysis of gating kinetics showed ALL accelerated the channel activation ofIto in M layers and partly inhibit the channel openings of/to in Epi, M and Endo cells. On the other hand, ALL mainly slowed channel deactivation of IKs channel in Epi and Endo layers without affecting its activation. Conclusions Our study gives partially explanation about the mechanisms of tmnsmural inhibition of/to and IKs channels by ALL in rabbit myocardium. These findings provide novel perspective regarding the anti-arrhythmogenesis application of ALL in clinical settings.

Oxygen vacancies effects on phase diagram of epitaxial La1-xSrxMnO3 thin films

We investigated the effects of oxygen vacancies on the structural, magnetic, and transport properties of Lal-xSrxMnO3 （x=0.1, 0.2, 0.33, 0.4, and 0.5） grown around a critical point （without/with oxygen vacancies） under low oxygen pressure （10 Pa） and high oxygen pressure （40 Pa）. We found that all films exhibit ferromagnetic behavior below the magnetic critical temperature, and that the films grown under low oxygen pressures have degraded magnetic properties with lower Curie temperatures and smaller magnetic moments. These results show that in epitaxial La1-xSrxMnO3 thin films, the magnetic and transport properties are very sensitive to doping concentration and oxygen vacancies. Phase diagrams of the films based on the doping concentration and oxygen vacancies were plotted and discussed.