8154型鱿钓渔船合适作业间距的研究

根据头足类对光反应的最低背景照度0.01 lx,使用叠加法海面照度计算方法,对鱿钓渔船不产生灯光干扰的合适照度间距进行分析,建立鱿钓渔船抛锚位置与相邻渔船的合适作业间距计算公式:L′Z=0.04×[Ln(P1) Ln(P2)] 0.14。根据该公式,集鱼灯总功率均为120 kW的2艘8154型鱿钓渔船的合适作业间距为0.68 n mile。     

Weavability of β-Hydroxybutyrate and β-Hydroxyvalerate Copolymers （PHBV）/ PLA Used in Artificial Blood Vessels

The β-hydroxybutyrate and β-hydroxyvalerate copolymers （PHBV）/pulylactic acid （PLA） is a new blocompatible material, which is developed through bacterial fermentation in vivo systems. The PHBV/PLA material could be used to make continuous filaments. However, features of artificial blood vessels, especially small diameter vascular grafts made of PHVB/PLA materials are not known. This research are to evaluate and improve wearability of the PHBV/PLA material, and to explore feasibility of using it in artificial blood vessels. Preliminary results showed that wearability of PHBV/PLV was not good, but its weavability could be improved by using methods of weak chemical, such as sizing. In this research, scanning electron microscope （SEM） was adopted to evaluate weavability of PHBV/PLV after sizing and observe surfaces of yarns and fabrics. Also, in order to set proper parameters in heat settings, differential scanning calorimetry （DSC） was used to identify glass transition temperature.     

欠驱动船舶RBF神经网络路径自适应跟踪控制

针对模型参数未知和存在外界干扰的三自由度欠驱动水面船舶路径跟踪控制问题,提出一种RBF神经网络控制器.该算法利用神经网络的函数逼近特性对船舶模型未知的非线性部分在线逼近并与反步法相结合进行设计,同时实现前进速度在线可调.通过Lyapunov稳定性方法分析验证了闭环系统的稳定性.仿真计算验证了该控制策略的有效性.     

猪源产ESBLs大肠杆菌三种耐药基因检测及分析

了解福建省闽西地区猪源产ESBLs大肠杆菌耐药现状。从龙岩市10个规模猪场分离的大肠杆菌中,按CLSI推荐的纸片扩散法筛选产ESBLs菌,对其分别用CTX-M、TEM和SHV等3种引物进行PCR扩增及测序分析。结果表明,105株大肠杆菌的产ESBLs检出率为28.6%(30/105);其ESBLs基因亚型以CTX-M型和TEM型为主,检出率分别为56.7%(17/30)和36.7%(11/30),SHV型检出率13.3%(4/30)较低;5株菌同时携带CTX-M和TEM基因,2株菌同时携带CTX-M和SHV基因;测序结果表明,共检测出3种基因型:CTX-M-15、TEM-2和SHV-12。     

Green fluorescent protein （GFP） transsenic pig produced by somatic cell nuclear transfer

Transgenic somatic cell nuclear transfer is a very promising route for producing transgenic farm animals. Research on GFP transgenic pigs can provide useful information for breeding transgenic pigs, human disease models and human organ xenotransplantation. In this study, a liposomal transfecUon system was screened and transgenic embryos were reconstructed by nuclear transfer of GFP positive cells into enucleated in vitro matured oocytes. The development of reconstructed embryos both in vitro and in vivo was observed, and GFP expression was determined. The results showed that porcine fe- tal-derived fibroblast cells cultured with 4.0 μL/mL liposome and 1.6 μg/mL plasmid DNA for 6 h resulted in the highest transfecUon rate （3.6%）. The percentage of GFP reconstructed embryos that de- veloped in vitro to the blastocyst stage was 10%. Of those the GFP positive percentage was 48%. Reconstructed transgenic embryos were transferred to 10 recipients. 5 of them were pregnant, and 3 delivered 6 cloned piglets in which 4 piglets were transgenic for the GFP as verified by both GFP protein expression and GFP DNA sequence analysis. The percentage of reconstructed embryos that resulted in cloned piglets was 1.0%; while the percentage of piglets that were transgenic was 0.7%. This is the first group of transgenic cloned pigs born in China, marking a great progress in Chinese transgenic cloned pig research.     

实验豚鼠饲养管理方法探讨

动物饲养条件能够影响实验动物的生长发育、生理功能与机体代谢,从而影响到实验结果的真实性、准确性和科学性.豚鼠是试验研究中用途较多的动物之一,但因其活动反应敏感,且具有一些特殊的生物学特征和生理解剖特点,因此,对豚鼠的实验室饲养和管理有一些特殊的要求,受到科研工作者的关注和重视.     

电场参数对长白猪精子电穿孔效率影响的研究

用假阴道法采集长白猪精液，经电击缓冲液清洗、适当稀释后，用天津理工学院生产的基因脉冲导入仪。选择14组不同的电场参数对其进行电击处理，电击后的精子经扫描电子显微镜观察和光学显微镜观察；在扫描电镜下观察到电穿孔，在光镜下观察到台盼蓝进入精子的头部内．结果显示：弱电场能使精子电穿孔，不同电场参数处理的精子电穿孔效率不同，最佳的电穿孔条件为电压700V，电容6μF，脉冲个数6个，穿孔几率达到18．6％．     

表面裂纹疲劳扩展的一种损伤力学方法

以核反应堆中压力容器和管道的破前漏（ＬＢＢ）分析为背景，从连续损伤力学的角度研究了压力容器和管道中环向和轴向半椭圆表面裂纹在循环载荷作用下的疲劳扩展问题。以标量损伤因子表征材料的疲劳损伤，由裂纹尖端的损伤演化导出了与Ｐａｒｉｓ公式形式相似的裂纹扩展方程，给出了Ｐａｒｉｓ公式的物理意义。由此发展了一种分析表面裂纹疲劳扩展过程中形状演化问题的损伤力学方法。     

双源CT低管电压联合迭代重建算法在冠状动脉成像中的应用研究

目的探讨80 k V低管电压联合迭代重建算法在CT冠状动脉成像中的应用价值.方法收集60例行冠状动脉检查的患者,所有患者心率均小于65次/min,体质量指数25 kg/m2,均采用Flash扫描模式,随机分为A组(120 k V)和B组(80 k V),B组根据原始数据重建方法不同分为B1组(传统滤波反投影,FBP)和B2组(正弦确认迭代重建技术,SAFIRE).主观对各组的图像质量进行评分,分析比较各组噪声(SD)、平均CT值(SI)、信噪比(SNR)、对比信噪比(CNR)和有效辐射剂量(ED)的差异.结果 A组和B2组主观图像评分差异无统计学意义(P0.05);B2组的图像噪声显著高于A组(P0.01),SNR和CNR相比无明显变化,差异无统计学意义(P0.05);B2组的图像噪声显著低于B1组(P0.01),SNR和CNR显著高于B1组(P0.01);A组平均有效辐射剂量为(7.30±0.68)m Sv,B组平均有效辐射剂量为(0.79±0.10)m Sv,B组辐射剂量明显小于A组,平均减少89%,两组比较差异具有统计学意义(P0.05).结论采用相同管电压时,与FBP算法比较,SAFIRE算法能显著改善冠脉的图像质量;对于BMI小于25 kg/m2的患者,采用80 k V管电压联合迭代重建算法可在不影响图像诊断的同时显著降低辐射剂量.     

临床异种移植百年进展(述评)

美国最近连续报道4例基因工程猪供给人的异种器官移植，这些进展打破了异种移植临床研究领域近30年的沉静。尤其是实验性的猪心脏移植取得初步成功，引发了广泛的关注。异种移植面向未来的临床应用迈出了关键性一步。这4个案例，无论是创新精神、技术进步、审批流程，还是伦理学的同步跟进，都值得我国同行学习和借鉴。30年来，基因工程（GE）动物器官已经能在非人类灵长类动物（NHPs）模型中长时间存活。这些实验中，预存抗体、补体激活、凝血状态等机制参与的超急性排异反应基本上得到有效控制。异种移植已经达到临床应用的起跑点。然而，未来仍然有四大问题需要解决：免疫排斥、生物安全、跨种适配和伦理心理。本文简要概括临床异种移植百年来的主要进展，其困难程度可见一斑，但希望和探索从未终止。