摘要
以北京松山5个不同密度（784,1 024,1 210,1 616,1 872株/hm2）的丁香（Syzygium aromaticum）天然林为对象,对其枯落物层及土壤层水文效应进行研究。结果表明：枯落物总蓄积量、最大持水率、最大持水量随丁香天然林密度的升高而增大。枯落物的总储量在13.19~31.66t/hm2之间;有效拦蓄能力在32.71~79.77t/hm2之间;枯落物最大持水量在50.76~119.29t/hm2之间,与浸泡时间呈明显的对数关系（R〉0.86）;枯落物最大持水率为385.72%~507.16%,枯落物吸水速率与浸泡时间呈明显的幂函数关系（R〉0.99）;同一密度土壤容重随土层深度的增加而增大,总孔隙度随密度的升高先增大后减小。初渗速率在37.50~54.55mm/min之间,入渗速率与入渗时间存在较好的幂函数关系（R〉0.99）。中密度丁香天然林水源涵养功能较强。
Objective To assess the value of 99mTc-2-methoxy isobutyl-isonitrile （99mTc-MIBI） sintigraphy in differential diagnosis between benign and malignant thymic masses. Methods Thirty-three patients underwent 99mTc-MIBI sintigraphy for thymic masses were enrolled. The early phase （15 rain after imaging agent injection） and delayed phase （2 h after imaging agent in- jection） images were collected. The uptake of the thymic mass （T） was compared with the normal tissue （N） of lung and the T/N ratio was calculated. The washout index and retention index were then calculated. Postoperatively, the patients were divided into three groups according to pathology： benign tumor （BT）, low-risk thymoma （LRT） including types A and AB, and intermediate- risk thymoma （IRT） including types B1, B2 and B3. Results In benign group, almost no MIBI uptake （except one of 133） ; in LRT group, different degree of MIBI uptake was observed; the sensitivity and specificity being 95.24% and 90.91%, respectively. The difference of T/N value between early and delayed phase in LRT was not significant （P〉0.05）. The differences of T/N ratio between early and delayed phase in LRT and IRT were significant （t=2.333,-4.995~P%O.05）. The differences of T/N ratio be tween early phase and delayed phase in the three groups were significant （F=19.514,19.072;P〈0.001）, but the difference between BT and IRT was not significant. The two hour retention index of LRT and IRT was （5.778±7. 716）% and （13. 315±9.410）%, respectively. Conclusion According to whether or not the imaging agent is absorbed by the thymic mass, a differential diagnosis between benign and malignant mass can initially be made, and, at the same time, according to the intake of T/N ratio and the changes of T/N from early phase to delayed phase, the grade of malignancy of the thyoma can be further determined.
出处
《青岛大学医学院学报》
CAS
2014年第1期59-61,共3页
Acta Academiae Medicinae Qingdao Universitatis
基金
林业公益性行业科研专项“都市型自然保护区保护与适应关键技术研究”（201004053）
关键词
水文效应
丁香
密度
枯落物
北京松山
thymus hyperplasia
thymoma
radionuclide imaging
99mTc-2-methoxy-isobutyl-isonitrile
diagnosis, differential
