Investigation of the Sharkskin melt instability using optical Fourier analysis

An optical method allowing the characterization of melt flow instabilities typically occurring during an extrusion process of polymers and polymer compounds is presented. It is based on a camera-acquired image of the extruded compound with a reference length scale. Application of image processing and transformation of the calibrated image to the frequency domain yields the magnitude spectrum of the instability. The effectiveness of the before mentioned approach is shown on Styrene-butadiene rubber (SBR) compounds, covering a wide range of silica filler content, extruded through a Göttfert capillary rheometer. The results of the image-based analysis are compared with the results from the sharkskin option, a series of highly sensitive pressure transducers installed inside the rheometer. A simplified version of the code used to produce the optical analysis results is included as supplementary material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48806.     

Radical‐scavenging properties of extracts from the white button mushroom,Agaricus bisporus

BACKGROUND: Agaricus bisporus is the premier cultivated edible mushroom but is usually considered to be of lesser value nutritionally and medicinally compared with other cultivated mushrooms. The objective of this study was to investigate the radical‐scavenging properties of methanolic extracts and the free radical‐processing enzyme activities of water extracts from A. bisporus fruit bodies. Analyses were performed on total fruit bodies from three strains and on separated stipe, cap and gills from one strain, all cultivated experimentally under the same conditions. RESULTS: EC₅₀ values of scavenging ability on 1,1‐diphenyl‐2‐picrylhydrazyl radicals (DPPH^?), scavenging ability on 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cations (ABTS^?+) and reducing power of methanolic extracts from total fruit bodies ranged between 1.7 and 5.0 and were 1.1–1.9 times higher in a white hybrid than in two wild strains, cream and brown. The gills exhibited higher antioxidant activities relative to the stipe and cap. In water extracts, glutathione peroxidase activities were up to eight times higher than glutathione reductase activities and no difference was observed between strains. Catalase activity was highest in the brown wild strain. The only significant differences in free radical‐processing enzymes between the three parts of the mushroom were higher catalase activity in the gills and lower glutathione reductase activity in the stipe. CONCLUSION: The radical‐scavenging properties of the button mushroom are comparable to those of other edible mushrooms and dependent on the strain and on the section of the fruit body. Copyright © 2008 Society of Chemical Industry     

The employment of strontium to activate mouse oocytes: effects on spermatid-injection outcome

The present research investigated the effects of various strontium concentrations, in combination with different incubation periods, on mouse parthenogentic oocyte activation and blastocyst development. The results for blastocyst development showed a trend indicating that 10 mM strontium for 3 h was the optimal strontium protocol. Ethanol, an agent that incites oocyte activation via a monotonic rise in calcium, was employed as a control. The outcome of blastocyst formation arising from parthenogenic ethanol activation was significantly less (P < 0.001) than that achieved by the optimal strontium protocol. To assess the impact of strontium oocyte activation on embryo viability following fertilization with immature germ cells, the protocol of 10 mM strontium for 3 h was applied to oocytes injected with round spermatids and then compared with other protocols. The results indicate that following round-spermatid injection the benefits derived from strontium artificial oocyte activation are evident during both pre- and post-implantation development. However, in order to adjust the protocol to the most effective round-spermatid injection in relation to the oocyte cell cycle, injection was done 1.5 h after strontium activation followed by another 1.5 h activation in strontium. The implementation of round-spermatid injection in combination with this oocyte-activation protocol led to live-birth outcomes not significantly different to those outcomes obtained by mature spermatozoa.     

Adaptational changes in cellular fatty acid branching and unsaturation of Aeromonas species as a response to growth temperature and salinity

The effects of growth temperature and salinity on the cellular fatty acids were investigated on Aeromonas caviae, Aeromonas hydrophila and Aeromonas sobria. Under optimal growth conditions, fatty acids patterns were dominated by even-numbered chains C(16:0), C(16:1cis9), C(18:1cis11), C(12:0) and C(14:0). Growth temperature modifications induced, in the three Aeromonas species, important changes in fatty acid (i) unsaturation, (ii) branching and (iii) chain length. An important decrease in the C(18:1cis11) fatty acid content was observed for the three species below 15 degrees C and above 25 degrees C. The evolution of C(18:1cis11) and C(16:0) showed a mirror image for the three Aeromonas species. Low NaCl concentrations did not elicit significant changes in the fatty acids content of the three Aeromonas species. However, for high NaCl concentration in the medium, the growth ability was related to an important decrease of the unsaturated to saturated fatty acids ratio indicating a membrane rigidification. Thermal and salinity adaptations were branched fatty acid-dependent for A. caviae, whereas this phenomenon was less significant for A. hydrophila and A. sobria.     

介入诊疗后并发两种不同类型肺栓塞的诊断与治疗

目的总结介入诊疗后严重并发症肺栓塞的类型、临床表现、治疗方法及预后的差异,以提高介入医师对此严重并发症的认识。方法收集３所医院１９９８－２００５年介入诊疗过程中所遇到的少见并发症肺栓塞病例,按照栓塞物不同分为碘油肺栓塞和血栓肺栓塞两种类型,就每种类型的临床特点及诊治经验加以总结。结果３所医院临床诊断介入诊疗后肺栓塞１０例,其中肺血栓栓塞５例,肺碘油栓塞５例。５例肺血栓栓塞患者表现为次日离床活动后突发性呼吸困难伴晕厥,２例死亡,３例经抗休克及局部溶栓治疗痊愈或好转。５例碘油肺栓塞患者表现为术后１～３d出现渐近性呼吸困难,无休克表现,经以给氧为主的综合治疗１５～５０d症状消失。结论肺栓塞是介入诊疗后的急重并发症,无深静脉血栓史患者也可发生急性血栓性肺栓塞,维持有效循环和溶栓治疗是有效疗法。碘油肺栓塞起病慢,治疗以保证供氧为主,肺内碘油可在１个月左右完全清除消失。肺增强CT对两者的诊断和鉴别诊断有重要意义。     

DSA在急性缺血性脑血管病介入治疗中的应用

目的探讨DSA在急性缺血性脑血管病介入检查及治疗中的应用价值。方法分析５５０例急性缺血性脑血管病患者进行介入治疗过程中DSA设备使用情况,总结合理利用DSA设备的经验。结果DSA的应用将有助于急性缺血性脑血管病快速诊断和介入治疗疗效评价;DSA实用投照角度的应用能够清晰显示目标血管狭窄病变的形态、程度等信息,为介入治疗提供最佳工作位置,有助于缺血性脑血管病的影像诊断和介入治疗;旋转DSA图像采集及图像三维重建技术的应用将有助于成功地开展介入治疗手术;应用DSA图像测量技术能够为操作医师选择介入材料提供精确的数据信息。结论合理利用DSA设备对于急性缺血性脑血管病的诊断和介入治疗手术成败起着至关重要的作用。DSA设备为介入治疗提供了良好的操作平台,DSA是诊断急性缺血性脑血管病的金标准。     

胰腺癌综合治疗现状及其价值

任何单一疗法治疗胰腺癌都难以获得理想的疗效。目前,可切除胰腺癌的治疗仍以根治性切除为主。放射治疗与手术联合应用,可提高手术切除率,减少肿瘤扩散;术中放疗可以缓解疼痛,提高生存率;对术后辅助放化疗的作用仍有争议。区域性化疗理论上有诸多优势,但仍需数据支持。物理治疗和生物治疗在胰腺癌的治疗中也已经得到广泛的重视。但只有建立以手术切除为主,联合放疗、化疗、物理及生物治疗的综合治疗体系,才有可能根本改变治疗现状,显著提高长期生存率,并改善生活质量。介入治疗作为重要的姑息治疗方法之一,近年来得到了长足的发展。     

阻塞性黄疸经皮经肝胆管引流术中胰管显影的原因分析

目的探讨阻塞性黄疸（OJ）患者在经皮肝穿刺胆管引流术（PTCD）中造影时胰管显影的原因及临床意义。方法回顾性分析１９９９年１月－２００７年２月间２５７例因OJ 经经皮经肝胆管造影（PTC）行介入治疗的患者的临床及影像学资料,其中DSA下胆胰管同时显影者３５例,观察胆胰汇合部解剖结构特点,归纳分析胰管显影的原因。结果３５例胰管显影者,确诊为胰胆管合流异常（PBM）３１例,另４例考虑与Oddi 括约肌功能障碍或解剖缺陷相关。结论PBM是导致阻塞性黄疸PTCD术中胰管显影的主要因素,探究胰管显影原因,有助于提高对壶腹部结构、功能的认识。     

基质细胞衍生因子－１介入治疗股骨头坏死的实验研究

目的探讨基质细胞衍生因子－１（SDF－１）治疗股骨头坏死的机制和疗效。方法选用日本大耳白兔３０只,制成激素性股骨头坏死模型后,随机分为３组。A组为对照组;B组为髓心减压＋生理盐水治疗组;C组为髓心减压＋SDF－１治疗组。各组动物均于治疗后８周处死,处死后分别进行股骨头骨密度测定及组织病理观察。结果SDF－１治疗后８周,骨密度明显增高,病理组织学表现血管数目增多,空骨陷窝减少。SDF－１治疗后显示股骨头修复效果明显。结论髓芯减压SDF－１移植治疗股骨头缺血性坏死效果明显,具有较广的临床应用前景。