航空发动机双转子-滚动轴承-机匣耦合系统动力学分析

以双转子航空发动机为研究对象，建立了航空发动机双转子-滚动轴承-机匣耦合动力学模型。在模型中，考虑了低压转子与高压转子的中介轴承、高压转子与机匣的碰摩、以及滚动轴承外圈与轴承座之间的弹性支承和挤压油膜阻尼等耦合作用。在滚动轴承模型中，考虑了滚动轴承间隙、非线性赫兹接触力以及变柔性VC（Varying compliance）振动等。最后，运用数值积分方法获取了系统响应，对双转子系统响应进行动力学分析与验证。     

Influential factors and formation of extrahepatic collateral artery in unresectable hepatocellular carcinoma

AIM: To analyze the influence factors and formation of extrahepatic collateral arteries (ECAs) in unresectable hepatocellular carcinoma (HCC) with or without chemoe-mbolization. METHODS: Detailed histories of 35 patients with 39 ECAs of HCC and images including computerized tomography scan, digital subtraction angiography were reviewed carefully to identify ECAs of HCC, ECAs arising from, and anatomic location of tumors in liver. Tumor sizes were measured, and relations of ECAs with times of chemoemb-olization, tumor size, and the anatomic tumor location were analyzed. Complications were observed after chemoemb-olization through ECAs of HCC with different techniques. RESULTS: Influence factors of formation of ECAs of HCC included the times of repeated chemoembolization, the location of tumors in liver, the tumor size and the types of chemoembolization. ECAs in HCC appeared after 3-4 times of chemoembolization (17.9%), but a higher frequency of ECAs occurred after 5-6 times of chemoembolization (56.4%). ECAs presented easily in peripheral areas (71.8%) of liver abutting to the anterior, posterior abdominal walls, the top right of diaphragm and right kidney. ECAs also occurred easily after complete obstruction of the trunk arteries supplying HCCs or the branches of proper hepatic arteries. Extrahepatic collaterals of HCC originated from right internal thoracic (mammary) artery (RTTA, 5.1%), right intercostal artery (RICA, 7.7%), left gastric artery (LGA, 12.8%), right inferior phrenic artery (RIPA, 38.5%), omental artery (OTA, 2.6%), superior mesenteric artery (SMA, 23.1%), and right adrenal and renal capsule artery (RARCA, 10.3%), respectively. The complications after chemoembolization attributed to no super selective cathet-erization. CONCLUSION: The formation of ECAs in unresectable HCC is obviously correlated with multiple chemoembolization, tumor size, types of chemoembolization, anatomic location of tumors. Extrahepatic collaterals in HCC are corresponding to the tumor locations in liver.     

The comparison of cetirizine, levocetirizine and placebo for the treatment of childhood perennial allergic rhinitis

Cetirizine (Zyrtec) is a potent and long-acting second-generation histamine H1- receptor antagonist for the treatment of allergic disease, such as allergic rhinitis and chronic idiopathic urticaria, in adult and child. It is a racemic mixture of levocetirizine (Xyzal) and dextrocetirizine. The purpose of this present study was to compare the efficacy of cetirizine, levocetirizine and placebo for the treatment of pediatric perennial allergic rhinitis. 74 perennial allergic rhinitis patients, aged 6 to 12 years old, assigned to 1 of 3 treatment groups for 12 weeks randomly. The effects of the three agents were compared with the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and Total Symptom Score (TSS) by diary. Nasal peak expiratory flow rate (nPEFR) and laboratory examinations including serum immunoglobulin E level, eosinophil cationic protein (ECP), blood eosinophil counts and eosinophil percentage in a nasal smear were evaluated among the three groups. The results revealed that both cetirizine and levocetirizine improved TSS in comparison with the placebo group, and ceterizine appeared to be more efficacious than levocetirizine at week 8 and week 12. The PRQLQ score showed significant decreased both in cetirizine and levocetirizine group, but there was no statistic significant difference between both groups. The eosinophil proportion in a nasal smear significantly decreased among the cetirizine in comparison with the placebo group but there was no statistic significant in levocetirizine groups. Both cetirizine and levocetirizine showed significant improvement in nPEFR in comparison with the placebo group, and ceterizine appeared to be more efficacious than levocetirizine. The 12-week treatment program showed that cetirizine was more effectious than levocetirizine.     

赖氨匹林对C3H小鼠移植性乳腺癌的抑制作用

背景与目的:在肿瘤的发生、发展中,环氧合酶(cyclooxygenase,COX)起了很重要的作用,而多种COX抑制剂可以抑制肿瘤细胞增殖,诱导肿瘤细胞凋亡。本实验观察不同浓度赖氨匹林(Aspisol)对小鼠移植性乳腺癌的抑制作用以及对肿瘤细胞凋亡和对肿瘤组织环氧合酶-2(COX-2)、Caspase-3蛋白的表达的影响,并探讨其抑制乳腺癌生长的作用机制。方法:用细胞悬液法将肿瘤细胞接种于C3H小鼠前肢腋窝皮下,制备可移植肿瘤模型。次日给予不同浓度的Aspisol腹腔注射,每天一次,共28天,用氟尿嘧啶(5-fluorouracil,5-FU)和生理盐水分别作为阳性对照和阴性对照。计算Aspisol的抑瘤率;原位凋亡检测法(TUNEL)检测Aspisol对肿瘤细胞凋亡的影响;免疫组化法检测Aspisol对小鼠肿瘤组织的COX-2、Caspase-3表达的影响。结果:175、350、700mg/kgAspisol对小鼠乳腺癌的抑瘤率分别为38.9%、48.2%、47.0%,10mg/kg5-FU的抑瘤率为60.4%。各给药组肿瘤细胞均呈现明显凋亡形态改变,不同浓度Aspisol均明显下调小鼠肿瘤组织COX-2的表达,增强Caspase-3表达。结论:Aspisol对C3H小鼠移植性乳腺癌的生长具有抑制作用;能诱导肿瘤细胞的凋亡,其机制可能与抑制COX-2表达、增强Caspase-3表达有关。     

Coexistence of allergic diseases: patterns and frequencies

The atopic march hypothesis suggests that allergy diseases often progress from atopic dermatitis to allergic asthma, and allergic rhinitis. How often can the classic progression of allergic diseases be observed in the pediatric patient population? This study aimed to observe the pattern of allergic diseases progression, onset age, disease intervals, and frequency of the allergic march. Data from the National Health Insurance Research Database in the period 1996-2008 were used to obtain a cohort of children with allergic disease. Physician's diagnosis was used to confirm the allergic disease based on the international disease coding. The age of disease onset was compared. There were 10,729 children aged <5 years enrolled from the 200,000 individuals randomly sampled in 2000. Of these, 5866 (54.7%) had been diagnosed with at least one allergic disease. The rate of only one of three diseases diagnosed was 29.8% (3195 patients), whereas 18.8% had two allergic diseases and 6.1% had all three allergic diseases. Only 4.2% of cases matched the allergic march. Patients with more than one disease had earlier onset age than those who had only one disease (4.17 versus 2.79 and 2.32 years old; p < 0.05). The allergic march accounts for only 4.2% in this study. A patient with only one allergic disease after the age of 4.17 years will not have another allergic disease until the age of 12 years. However, a patient with an allergic disease before 2.79 years old will probably have another allergic disease in 1.96-2.5 years.     

三种非球面单焦点丙烯酸酯IOL植入术后暗视下视觉质量的观察

目的: 研究三种非球面丙烯酸酯人工晶状体(intraocularlens,IOL)植入术后患者在最佳矫正视力及暗视下(3cd/m2)对比敏感度(contrast sensitivity,CS)的变化,评价白内障超声乳化联合单焦点非球面丙烯酸酯IOL植入术后患者的视觉质量。方法: 选取符合条件的年龄相关性白内障患者77例90眼,2011-12/2012-11于我院行白内障超声乳化吸除联合IOL植入术,术前将患者随机分成三组,1组(25例30眼)植入疏水性染黄色丙烯酸酯IOL(HOYA),2组(28例30眼)植入亲水性丙烯酸酯IOL(Rayner)及3组(24例30眼)植入亲水性丙烯酸酯表面肝素处理IOL(XO)。所有患者于术后1,3mo均行最佳矫正视力(标准对数视力表)检查及暗视无眩光状态下的CS检查,所得结果进行统计学分析。结果: 患者术后1,3mo时,各组之间最佳矫正视力无明显统计学差异(P>0.05);患者1,3mo暗视无眩光状态下CS结果(标准化后的CS值:lgCS),三组患者之间CS值并无统计学差异(各组之间P>0.05),但HOYA组患者CS结果略下降。结论: 三组患者之间,术后1,3mo时最佳矫正视力及对暗视无眩光状态下CS结果无明显差异(P>0.05)。由于蓝光滤过型IOL对视网膜的潜在保护作用,因此植入染黄色滤过蓝光的IOL是可取的,特别是对儿童及青年白内障患者是必要的。