BP网络在试验数据处理中的应用

在生产和科学实验中，选取的数学模型主要是线性回归方程形式，采用回归分析方法确定模型的参数。由于BP网络可对任意形状的函数曲线进行逼近，因此，采用BP网络建立的数学模型较上述形式的数学模型具有更小的方差。能够寻找到最优的工艺条件。     

弹簧式柔性阀瓣安全阀在线整定技术分析与探讨

针对克罗斯比(Crosby)阀门公司生产的弹簧式柔性阀瓣安全阀的结构特点，对影响其在线测量整定准确性的主要因素进行了分析与探讨，提出了在柔性阀瓣密封面积未知的情况下，对弹簧式安全阀的起跳动作压力在线测试与整定的方法。     

A novel bioactive porous bredigite (Ca<Subscript>7</Subscript>MgSi<Subscript>4</Subscript>O<Subscript>16</Subscript>) scaffold with biomimetic apatite layer for bone tissue engineering

The aim of this study was to develop a novel bioactive, degradable and cytocompatible bredigite (Ca₇MgSi₄O₁₆) scaffold with biomimetic apatite layer for bone tissue engineering. Porous bredigite scaffolds were prepared using polymer sponge method. The bredigite scaffolds with biomimetic apatite layer (BTAP) were obtained by soaking bredigite scaffolds in simulated body fluid (SBF) for 10 days. The porosity and in vitro degradability of BTAP scaffolds were investigated. In addition, osteoblast-like cell morphology, proliferation and differentiation on BTAP scaffolds were evaluated and compared with β-tricalcium phosphate (β-TCP) scaffolds. The results showed that BTAP scaffolds possessed 90% of porosity. The degradation of BTAP scaffolds was comparable to that of β-TCP scaffolds. Cells on BTAP scaffolds spread well and presented a higher proliferation rate and differentiation level as compared with those on β-TCP scaffolds. Our results indicated that BTAP scaffolds were degradable and possessed the function to enhance cell proliferation and differentiation, and might be used as bone tissue engineering materials.     

血管内介入治疗滤器源性下腔-髂静脉长段阻塞8例

【摘要】 目的 探讨血管内介入治疗滤器源性下腔-髂静脉长段阻塞的可行性和安全性。方法 2014年1月至2016年10月采用经皮腔内血管成形术（PTA）和支架植入术治疗8例下腔静脉滤器置入后慢性下腔-髂静脉长段闭塞患者。收集8例患者临床及影像学资料,对血管内介入治疗方法、技术成功率、并发症发生率及随访情况进行统计分析。结果 8例患者闭塞段血管均成功开通。7例球囊成形结合植入支架术后即刻造影显示支架位置良好,支架内血流通畅,侧支血管减少;1例球囊成形结合支架植入术后发生急性支架内血栓形成,经导管直接溶栓2 d后复查造影显示支架内血栓完全溶解,血流恢复通畅。术后随访2～13个月,平均（4.7±3.9）个月。至末次随访,8例患者CT及下肢静脉造影均显示支架在位良好,其中3例支架内可见内膜轻度增生,但血流均通畅。结论 滤器长期置入可导致慢性下腔-髂静脉长段闭塞。球囊成形及支架植入可有效开通闭塞血管,是一种安全可行的方法。

     

大气呼吸模式激光推进数值分析

详细分析了激光击穿空气和激光维持等离子体爆轰波(LSD)的传播机制,基于Navier-Stokes方程建立了考虑湍流、等离子体辐射的流场分析模型,采用有限体积法系统分析了推进器喷管内等离子体冲击波流场的演变规律,研究了单脉冲激光能量大小和脉宽对推进性能的影响。数值仿真中明显捕捉到有关实验中观察到的马赫杆的产生与移动过程;得出了推力和冲量耦合系数随脉冲能量、脉宽的变化关系,计算结果与德国空间中心实验吻合得较好,为脉冲激光器的选择和脉冲参数优化提供了参考依据。     

三甲基铟、三乙基铟制备的研究进展

根据国外三甲基铟和三乙基铟制备的发展概况,从合成与纯化两论述了基研究进展。     

Preparation and application of antimony mono (isooctyl thioglycolate) di(n-dodecanethiol)

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Crosslinking effect of Nordihydroguaiaretic acid (NDGA) on decellularized heart valve scaffold for tissue engineering

Decellularized heart valve scaffolds possess many desirable properties in valvular tissue engineering. However, their current applications were limited by short durability, easily structural dysfunction and immunological competence. Although crosslinking with chemical reagents, such as glutaraldehyde (GA), will enhance the mechanical properties, the low long-term stability and cytotoxicity of the scaffolds remains potential problem. Nordihydroguaiaretic acid (NDGA) is a bioactive natural product which is able to crosslink collagen and was proven to be effective in preparation of scaffold for tendon tissue engineering. In this paper, NDGA crosslinked decellularized heart valve scaffolds demonstrated higher tensile strength, enzymatic hydrolysis resistance and store stability than the non-crosslinked ones. Its mechanical properties and cytocompability were superior to that of GA-crosslinked heart valve matrix. Below the concentration of 10 μg/ml, NDGA has no visible cytotoxic effect on both endothelial cells (EC) and valvular interstitial cells (VIC) and its cytotoxicity is much less than that of GA. The LC50 (50% lethal concentration) of NDGA on ECs and VICs are 32.6 μg/ml and 47.5 μg/ml, respectively, while those of GA are almost 30 times higher than NDGA (P < 0.05). ECs can attach to and maintain normal morphology on the surface of NDGA-crosslinked valvular scaffolds but not GA-crosslinked ones. This study demonstrated that NDGA-crosslinking of decellularized valvular matrix is a promising approach for preparation of heart valve tissue engineering scaffolds.     

国内外光稳定剂的现状及发展趋势

介绍光稳定剂的类别、作用机理及应用,综述国内外光稳定剂的发展历程和现状,探讨了光稳定剂的发展趋势。