Polymorphonuclear leukocyte mediated oxidative inactivation of alpha-1-proteinase inhibitor: Modulation by nitric oxide

Alpha-1-proteinase inhibitor activity was studied in presence of resting and activated polymorphonuclear leucocytes. Four different agonists; phorbol myristic acetate, N-formyl-methionyl-leucyl-phenylalanine, opsonised zymosan and arachidonic acid decreased the inhibitor activity by 23.3%, 20%, 12% and 16.6^ respectively. The inhibitor activity was protected by using various free radical scavengers. Catalase and superoxide dismutase both restored activity by about 18%, mannitol by 13% and sodium azide by 17.3%. The inhibitor activity was also protected significantly by pretreatment of polymorphs with L-Arg, a precursor of nitric oxide, before activation. L-Arg was also observed to suppress the generation of superoxide and hydroxyl radical appreciably. The nitric oxide synthase inhibitor, aminoguanidine drastically inhibited the nitrite release and reversed the protection offered by L-Arg to the inhibitor activity. Our results indicate a multifactorial nature of the inactivation process, the culprit species being superoxide, hydrogen peroxide, hydroxyl radical and hypohalides. Nitric oxide seems to scavenge the superoxide radical directly after its formation rather than inhibiting its generation by NADPH oxidase as was believed earlier.     

磷酸氢二钠对海水混浆淤泥土加固的激发作用和缓蚀作用

首先通过力学试验研究表明,在添加弱碱性无机盐Na2HPO4的情况下水泥土的强度可以有较大幅度的提高;其次,水泥土无荷和有荷膨胀试验表明在Na2HPO4掺量0.25%(质量百分比)时,可以获得较好的膨胀控制效果;再次借助于失重法研究Na2HPO4对钢材的缓蚀效果,表明该配方可以有效的降低海水水泥浆液对#45号钢挂片的腐蚀作用;最后通过扫描电镜直接观测法研究了海水混浆水泥土在添加缓蚀剂后的结晶状态变化情况,表明无机缓蚀剂Na2HPO4可以提高水泥土的结晶度,增强力学性能。研究表明添加适量Na2HPO4和超细硅粉的海水混浆淤泥土在提高水泥土强度的同时,能够将膨胀控制在合理的范围内,同时起到了良好的缓蚀作用。     

紫苏油抗过敏·炎症的研究

本文介绍了紫苏子中脂肪酸类成分抗过敏·炎症作用及其作用机理,即抑制血 小板活化因子（ＰＡＦ）和白三烯的研究概况．并在抑制ＰＡＦ和白三烯（ＬＴＢ４、Ｃ４、Ｄ４）方 面,与同系列脂肪酸ＥＰＡ、ＤＨＡ进行了比较,进而提出了紫苏油开发利用新的发展方向。     

大叶树皮中发芽抑制物质的研究

为了阐明大叶树皮（ＦｒａｘｉｎｕｓｒｈｙｎｃｈｏｐｈｙｌｌａＨａｎｃｅ）中发芽抑制物质的种类和活性,对大叶树皮的酒精提取物进行了分离和纯化,得到了一种白色粉末状化合物．通过化学定性反应和紫外吸收测定,初步推测该化合物是 ６．７－二羟基香豆素－（６）－（β）－Ｏ－葡萄糖甙（七叶甙, ｅｓｃｕｌｉｎ）．它在较高浓度时（＞ ４．０ × １０－’ｍｏｌ·Ｌ－１）对白菜种子的萌发有抑制作用,在低浓度时（＜ ８．０ ×１０－ｍｏｌ·Ｌ－１）对白菜种子的萌发有一定的促进作用．     

双联叶片泵与变量叶片泵的比较

本文从变速原理、静态特性、动态特性及系统效率分析等方面对双联叶片泵和变量叶片泵进行了比较,为液压系统动力源的合理选择提供了有价值的资料.     

不同磷酸盐在两种水质条件下对铁释放的影响

利用管段反应器,通过连续监测一定停留时间的铁释放量,定量比较4种磷酸盐(正磷酸钠、六偏磷酸钠、磷酸氢二钠、磷酸二氢钠)分别在淡化海水(低碱度、低硬度、高氯离子等水质条件)和自来水中对于铁释放的影响。结果表明,磷酸二氢钠和六偏磷酸钠分别在淡化海水和自来水中抑制铁释放效果最好。     

足底静脉泵预防脊柱创伤术后DVT的有效性评价

目的：探讨足底静脉泵在预防脊柱创伤术后深静脉血栓形成的有效性和安全性。方法：将2011年6月至2012年7月收治的脊柱损伤患者86例,随机分为观察组和对照组,每组各43例。术后均给予常规药物预防和护理干预,观察组在此基础上增加给予足底静脉泵物理干预。分别于术前和术后7d行下肢彩色多普勒超声检查,比较两组患者DVT发生率、下肢肿胀和D-二聚体含量。结果：术后7d,两组患者下肢肿胀明显缓解,其中观察组下肢周径差值仅为（1．3±0．3）cm,显著小于对照组（P〈0.05）,且D-二聚体含量呈下降趋势,仅为（0．6±0．1）ng／L,显著低于对照组（P〈0．01）。两组患者术后7d深静脉血栓发生率分别为2．3％和18．6％,观察组较低（P〈0．05）,两组在治疗过程中均未出现明显的不良反应。结论：足底静脉泵在预防脊柱创伤术后深静脉血栓形成中具有较好的临床效果且能够安全、够快速缓解腿部肿胀,值得临床推广。     

海水养殖践行“海洋负排放”的途径

减排增汇是我国实现碳中和目标的必然途径。海洋作为地球上最大的碳库,渔业生物的碳汇功能也受到关注。中国是世界上最大的海水养殖国家,以非投饵型的贝藻养殖为主,养殖种类丰富、营养层次多样、养殖技术成熟,"海洋负排放"的发展潜力巨大。然而,贝藻类养殖的负排放过程复杂,其负排放的科学原理、过程机制、计量方法及增汇途径等科技问题正在被逐步认知和解决。文章阐释了渔业碳汇的研究进展、存在问题和可能影响,提出了拓展养殖空间和提高养殖单产、基于养殖容量管理制度的海水养殖绿色发展、多营养层次综合养殖模式、蓝碳牧业工程、海洋人工上升流增汇工程等践行"海洋负排放"的技术途径和对策建议。     

可编程注射泵控制系统中LCD控制器T6963C的应用

为了减小了医务人员在工作紧张、简单的重复性较高的操作过程中犯错的机率,对各阶段的输入过程一目了然,本文以主控芯片TMS320LF2407A为主,在进行注射泵设计时,采用TOSHIBA公司生产的一款LCD控制器T6963C,提出了一种全新的显示模式--坐标显示。点阵式液晶显示模块性能稳定、价位较低,适合应用于便携式智能仪器仪表,是一种具有较高显示功能的显示器件。本文介绍了一种DSP控制器的设计方法,用于对内藏T6963C控制器液晶模块进行字符图形显示控制,给出了硬件接口的设计实现以及软件流程图。     

Effects of structural parameters and rigidity of driving diaphragm on flow characteristics of micro valveless pump

The structure and operating principle of micro valveless pump were investigated theoretically and experimentally. The mathematical model of pressure and flow rate within the micro nozzle/diffuser was established to analyze the effects of nozzle/diffuser parameters on the output flow rate of the micro valveless pump. The experiments were carried out with different structural parameters, driving frequencies, vibration amplitudes and stiffness of the driving diaphragms. Effects of the structural parameters and driving conditions on the operation performance of the pump are discussed in detail. The work provides useful reference for structure optimization selection of the driving diaphragm of micro valveless pump. Project supported by National Natural Science Foundation of China (Nos. 50175098, 59835160)