Comparison of Melting Processes for WPC and the Resulting Differences in Thermal Damage,Emissions and Mechanics

The necessity for resource-efficient manufacturing technologies requires new developments within the field of plastic processing. Lightweight design using wood fibers as sustainable reinforcement for thermoplastics might be one solution. The processing of wood fibers requires special attention to the applied thermal load. Even at low processing temperatures, the influence of the dwell time, temperature and shear force is critical to ensure the structural integrity of fibers. Therefore, this article compares different compounding rates for polypropylene with wood fibers and highlights their effects on the olfactory, visual and mechanical properties of the injection-molded part. The study compares one-step processing, using an injection-molding compounder (IMC), with two-step processing, using a twin-scew-extruder (TSE), a heating/cooling mixer (HCM) and an internal mixer (IM) with subsequent injection molding. Although the highest fiber length was achieved by using the IMC, the best mechanical properties were achieved by the HCM and IM. The measured oxidation induction time and volatile organic compound content indicate that the lowest amount of thermal damage occurred when using the HCM and IM. The advantage of one-time melting was evened out by the dwell time. The reinforcement of thermoplastics by wood fibers depends more strongly on the structural integrity of the fibers compared to their length and homogeneity.     

Effects of micronized okara dietary fiber on cecal microbiota,serum cholesterol and lipid levels in BALB/c mice

Abstract

Micronized by a dry grinding method (D-ODF) or a wet granulating method (W-ODF), okara dietary fiber (ODF), was fed to BALB/c mice for 28?d. The water holding capacity of D-ODF and W-ODF was significantly enhanced after micronization. W-ODF had a larger swell capacity and a higher content of soluble dietary fiber than crude ODF and D-ODF. After feeding for 28?d, the populations of Escherichia coli and Lactobacilli in the cecum were significantly lower and higher in the W-ODF group than other groups, respectively, while the population of Bifidobacterium increased in all groups. The effect of each diet on the population of E. coli. Lactobacilli and Bifidobacterium was all maintained for a short period of time except that the effectiveness of W-ODF diet on the Bifidobacterium population lasted slightly longer than other diets. At the end of the feeding period, serum total cholesterol (TC) and triglyceride in D-ODF and W-ODF diets were significantly lower and HDL-C/TC ratio was significantly higher than those in crude ODF.     

高度近视合并青光眼患者视神经纤维层厚度的变化

目的:通过光学相干断层成像(OCT)检测高度近视合并青光眼患者视神经纤维层厚度的变化规律。方法:选取2017-01/12于我院进行治疗的高度近视合并青光眼患者80例160眼作为观察组,并选择同期于我院进行体检的健康志愿者60例120眼作为对照组。采用OCT分析所有受检者视神经纤维层厚度。结果:与对照组受检者相比,观察组患者鼻侧、颞上、鼻下、鼻上、颞下及全周平均视神经纤维层厚度均降低,而颞侧视神经纤维层厚度升高(P<0.05),且观察组中屈光度-10.00^-11.00D的患者鼻侧、颞上、鼻下、鼻上、颞下及全周平均视神经纤维层厚度均显著高于屈光度≥-12.00D的患者(P<0.05)。Spearman相关分析结果显示,观察组患者屈光度的绝对值与鼻侧、颞上、鼻下、颞下及全周平均厚度视神经纤维层厚度呈负相关,与颞侧视神经纤维层厚度呈正相关。结论:高度近视合并青光眼患者除颞侧外各象限视神经纤维层变薄。     

Diffusion tensor imaging and fiber tractography of C6 rat glioma

PURPOSE: To apply diffusion tensor images using 30 noncollinear directions for diffusion-weighted gradient schemes to characterize diffusion tensor imaging (DTI) features associated with C6 glioma-bearing rat brains, and ideally visualize fiber tractography datasets. MATERIALS AND METHODS: Fiber tractographies of normal male Fischer 344 rat brains were constructed from DTI datasets acquired with a 30 noncollinear diffusion gradient scheme. Cultured C6 cell were intracranially injected into the cortex of male Fischer 344 rats. The time course of the tumor growth was monitored with DTI and fiber tractography using diffusion-weighting gradients in 30 noncollinear directions. RESULTS: Fiber tractographies through the corpus callosum (CC) were easily visualized with the 30-direction gradient scheme, and the fiber trajectories of the motor cortex and striatum were well represented in normal rats. Fiber tractography indicated that the neuronal fibers of the CC were compressed or disappeared by growing C6 glioma, which affected surrounding brain tissue. CONCLUSION: We have demonstrated in this study that fiber tractography with the 30 noncollinear diffusion gradient scheme method can be used to help provide a better understanding regarding the influence of a tumor on the surrounding regions of normal brain tissue in vivo.     

烫伤大鼠垂体前叶P物质和降钙素基因相关肽神经的变化

目的　观察烫伤早期大鼠垂体前叶P物质 (SP)与降钙素基因相关肽 (CGRP)神经的形态分布变化。　方法　采用大鼠 30 %TBSAⅢ度烫伤模型 ,于伤后 1、2、6、10、12、2 4、72h 7个时相点 ,对垂体前叶SP和CGRP两种肽能神经行免疫组织化学染色观察 ;经图像分析测定 ,比较两种神经覆盖面积的变化。　结果　两种肽能神经的形态变化明显 ;伤后 1hSP、CGRP神经数目与对照相比分别增加 85 .7%和 6 0 .5 % ,神经纤维的膨体、分枝等明显增多 ;2h后减少 ,2 4h后趋于恢复。图像分析显示 :两种肽能神经的覆盖面积呈正相关变化 ,其基本变化趋势为伤后 1h升高 ,随后降低 ,伤后 12h降至最低点 ,然后回升。　结论　烫伤后早期大鼠垂体前叶的SP与CGRP神经形态分布发生明显变化 ,可能参与了全身应激反应的功能调节     

Description of a flow optimized oxygenator with integrated pulsatile pump

Extracorporeal membrane oxygenation (ECMO) is a well-established therapy for several lung and heart diseases in the field of neonatal and pediatric medicine (e.g., acute respiratory distress syndrome, congenital heart failure, cardiomyopathy). Current ECMO systems are typically composed of an oxygenator and a separate nonpulsatile blood pump. An oxygenator with an integrated pulsatile blood pump for small infant ECMO was developed, and this novel concept was tested regarding functionality and gas exchange rate. Pulsating silicone tubes (STs) were driven by air pressure and placed inside the cylindrical fiber bundle of an oxygenator to be used as a pump module. The findings of this study confirm that pumping blood with STs is a viable option for the future. The maximum gas exchange rate for oxygen is 48mL/min/L(blood) at a medium blood flow rate of about 300mL/min. Future design steps were identified to optimize the flow field through the fiber bundle to achieve a higher gas exchange rate. First, the packing density of the hollow-fiber bundle was lower than commercial oxygenators due to the manual manufacturing. By increasing this packing density, the gas exchange rate would increase accordingly. Second, distribution plates for a more uniform blood flow can be placed at the inlet and outlet of the oxygenator. Third, the hollow-fiber membranes can be individually placed to ensure equal distances between the surrounding hollow fibers.     

纤维桩用于前牙残冠修复的临床应用

目的探讨纤维桩在前牙残冠修复中的临床应用。方法将恒前牙残冠残根病例共36例随机分为纤维桩(观察组)和金属桩核修复组(对照组),随访观察6、12个月。结果观察组1例发生牙体折裂、修复体脱落,对照组根折3例,脱落4例。结论纤维桩在恒前牙核桩冠修复中固位与金属桩无显著差异,而很少会发生根折或牙折,在恒前牙残冠残根修复中具有广阔的应用前景。     

Macromorphology and histology of intramuscular hemorrhages in cases of drowning

In a prospective autopsy series of 39 cases of fatal drowning, the detailed dissection of the skeletal muscles of the neck, anterior / posterior trunk and the upper extremities in layers revealed intramuscular hemorrhages of different size and shape in 20 cases (51.3 %). Light microscopy examination showed a premortal (vital/agonal) type of muscular alteration in 7 (50 %) out of 14 macroscopical hemorrhage-positive cases. These hemorrhages and histological muscle alterations are attributed to agonal convulsions, hypercontraction and overexertion of the affected muscle groups. As long as no cutaneous or subcutaneous hematomas above the hemorrhages can be found, these autopsy findings (with special reference to histology) can serve as an additional criterion concerning the differentiation of drowning and another cause of death. Received: 31 July 1998 / Received in revised form: 31 August 1998     

超滤法测定表面活性剂临界胶束浓度

对超滤法测定表面活性剂的临界胶束浓度(CMC)的单点式超滤法、超滤曲线法、双点式超滤法进行了研究,比较了理想与真实超滤曲线,对超滤膜用于超滤法测定CMC的适用性及容积效应进行了考察.初步探讨了用双点式超滤法代替作超滤曲线法测定CMC的可行性和准确性,并与单点式超滤法进行了比较.试验结果表明,用双点式超滤法测定CMC具有准确性较高、操作简便、节省时间和节约样品用量等优点.用双点法测得的SDS和SLAS的CMC分别为6.70mmol/L和1.40mmol/L;与超滤曲线法得到的CMC相比,偏差分别为2.9%和3.4%.     

颈总动脉周交感神经网剥脱切除术后痉挛肌肉内酶与肌纤维结构的研究

目的　探讨交感神经切断后,痉挛肌肉内酶与肌纤维结构的改变。方法　将20只wistar大白鼠作成痉挛性模型,分成两组,随机选择1组行颈总动脉周交感神经网剥脱切除术,另1组作为对照,于术后第20天切取两组大鼠部分肱三头肌组织,采用(Ellman)爱尔蒙法及AU1000检测仪测定肌组织内乙酰胆碱酯酶活性和肌酸激酶含量,在IBAS图像分析仪上观察两组肌组织内快收缩肌纤维与慢收缩肌纤维的改变情况。结果　交感神经切断后,乙酰胆碱酯酶活性和肌酸激酶含量明显下降,分别从（3.37±1.01）U/g降至（2.15±1.42）U/g（P＜0.01）;（3582.90±1561.7）IU/L降至（420.10±73.55）IU/L（P＜0.01）,快肌纤维明显减少,从（275727.31±98240.23）μm