Expression of VEGF and bFGF in rat model of pressure ulcer

AIM:To study the effects of vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(bFGF) on the molecular pathogenesis of pressure ulcer.METHODS:SD rats were randomly divided into control group and experiment group. The pressure ulcer model was established by magnetic disk circulating compression method. HE staining was used to observe the pathological changes of the skin in the rats. The expression of VEGF and bFGF in the tissues was detected by immunohistochemical method. RESULTS:The expression of VEGF and bFGF in the tissues of rat Ⅲ-degree pressure ulcer was lower than that in the surrounding tissues and normal skin(P<0.01). The changes of VEGF and bFGF were consistent(κ=0.58). CONCLUSION:The expression levels of VEGF and bFGF are decreased in the tissues of rat pressure ulcer, suggesting that they may be the potential key factors in the difficult healing of pressure ulcer.     

气流式桑树伐条机的研制试验初报

采用气流切割技术设计气流式桑树伐条机。气流切割效能受到压力、流量、喷射形式等多方面因素的影响,设计了适合气流式桑树伐条机作业的气流压力和喷嘴尺寸等,对不同组合的气流压力和不同喷嘴直径进行了桑枝剪切试验。结果表明,在工作压力1.5 MPa、喷嘴直径1.4~1.6 mm的条件下,气流式桑树伐条机的有效剪切直径超过30 mm,工效>2 500株/h;为减少压力损耗,高压输气管长度不宜超过4 m。该机进一步完善消音技术和控制噪音后,有望开发出结构简单、操作方便的实用机型应用于生产。     

餐厨垃圾三相分离影响因素工程化研究

本文主要研究餐厨垃圾处理过程中,加热方式、温度、压力等参数对餐厨垃圾油相、水相、固相分离效果的影响。实验结果表明:加热设备蒸汽直喷加热的方式,固液分离固渣含水率降低5%~9%,提油率从2.76%提升到3.23%;加热装置物料温度70℃,固液分离设备压力为4bar,油相、水相及固相的分离效果更佳。     

Influences of ultra‐violet (UV)‐blue light radiation on the growth of cotton. II. Photosynthesis,leaf anatomy,and iron reduction

Cotton (Gossypium hirsutum L.) plants grown under low pressure sodium lamps (LPS) developed chlorosis which was similar in appearance to iron‐stress induced chlorosis, while plants under cool white fluorescent lamps (CWF) at the same level of photosynthetically active radiation (PAR) developed normally. These illumination sources differ in spectral irradiance; CWF lamps emit ultra violet (UV), whereas LPS lamps do not. Ultraviolet radiation is capable of reducing Fe³⁺ to Fe²⁺ through a chlorotic leaf which may be important in establishing an active iron fraction in the leaf. Root reduction of Fe³⁺ to Fe²⁺ was lacking in Fe‐stressed cotton under LPS light, but was present under CWF light. Net photosynthesis, photosynthetic electron transport, and leaf chlorophyll content were lower under LPS than CWF light in most of the growing media studies (soil or solutions with nitrate‐ or ammonium‐nitrogen supplied). Chloroplast ultrastructure and leaf thickness were also altered by LPS irradiance. Electron microscopic studies with plants grown in nutrient solutions for 4 weeks suggested that chioroplastic granal disorganization was more directly associated with diminished iron supplies than with light source. However, plants grown in soil for 6 weeks under LPS light had granal disorganization similar to that found in iron‐stressed plants. These studies suggest an important role for UV radiation in influencing the activity of iron in plants.     

Therapeutic effect of neuregulin-1β on pressure overload-induced myocardial hypertrophy in rats

AIM：To investigate the therapeutic effect and the mechanism of neuregulin-1β (NRG-1β) on the rat model of myocardial hypertrophy induced by pressure overload．METHODS：Eight weeks after coarctation of abdominal aorta, the Wistar rats were randomly divided into 4 groups: myocardial hypertrophy (model) group, sham operation (sham) group, NRG-1β treatment group (intravenous injection of NRG-1β at dose of 10 μg/kg daily for 7 d) and NRG-1β+Herceptin (HERCE) treatment group ［intravenous injection of NRG-1β (10 μg/kg) plus HERCE (10 μg/kg) daily for 7 d］. The characteristics of heart functions were evaluated by the methods of hemodynamics and echocardiography. Masson staining was employed to observe the pathological changes of myocardial tissues. The concentration of angiotensin II (Ang II) in myocardial tissues was measured by radioimmunoassay. The level of tumor necrosis factor α (TNF-α) in myocardial tissues was detected by ELISA. The mRNA expression of B-cell lymphoma/leukemia-2 (bcl-2) and bcl-2-associated X protein (bax) in the myocardium was determined by RT-PCR. RESULTS：The left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were higher, while the left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) were smaller in NRG-1β group than those in model group. The left ventricular end-systolic pressure (LVESP) and maximal rate of increase/decrease in left ventricular pressure (±dp/dtmax) were higher, and left ventricular end-diastolic pressure (LVEDP) was significantly lower in NRG-1β group than those in model group. Compared with model group, treatment with NRG-1β decreased collagen volume fraction (CVF), reduced the Ang II and TNF-α, increased bcl-2 mRNA expression, and decreased bax mRNA expression in myocardial tissues. No difference of the above parameters between model group and NRG-1β+HERCE treatment group was observed. CONCLUSION：NRG-1 reduces the expression of Ang II and TNF-α in myocardial tissues in pressure-overload rats, thus reducing Ang II and TNF-α mediated myocardial interstitial remodeling. Increase in the mRNA expression of bcl-2 and decrease in the mRNA expression of bax by NRG-1 inhibit myocardial cell apoptosis, which is responsible for its role of improving cardiac function of myocardial hypertrophy induced by pressure overload.     

邯郸市耕地资源压力动态变化及调控策略

根据1978～2008年相关数据,分析了邯郸市耕地-粮食-人口系统的动态变化,计算了耕地压力指数,并分析了该指数的动态变化及成因。结果表明:1978年以来邯郸市耕地面积及其人均量持续减少;粮食总产量及人均产量总体呈增加趋势;受其影响,最小人均耕地面积和耕地压力指数呈现相似的变化趋势。最后探讨了缓解耕地压力的调控策略,指出保持区域内一定数量的耕地、种植高产作物、严格控制人口增长是缓解耕地压力的重点。     

沟槽滤嘴对中式低焦油卷烟主流烟气的影响

[目的]为中式低焦油卷烟设计中应用沟槽滤嘴提供一定的参考依据。[方法]研究不同透气度接装纸和不同吸阻沟槽滤棒对常规烟气成分、卷烟危害性评价指数的影响。[结果]尽管随着沟槽滤嘴中接装纸透气度或沟槽滤棒吸阻的增加,常规烟气成分、卷烟危害性评价指数均呈下降趋势,但对卷烟危害性评价指数中7种物质释放量的影响作用却有明显的异同。[结论]通过打孔接装纸和沟槽滤棒的配伍性,可以全面有效降低卷烟危害性评价指数中的7种物质,实现沟槽滤嘴在中式低焦油卷烟中的应用。     

RY型热压机液压传动系统的改进设计

根据对ＲＹ型热压机的实际使用情况，论证和分析了该机液压传动系统在设计和使用性能上存在的不足之处；通过对充压需油量进行计算和高压泵的变量特性进行分析，提出了二级调压回路和充压方式的改进设计措施．经对该机进行技术改造后投入生产性运行，证明效果良好．为主产厂家改进产品和中小型人造板厂进行设备改造提供了依据．     

万家沟水库坝基(肩)固结灌浆的实施与分析

万家沟水库砼双曲拱坝为自治区第一座此类坝型。对坝基（肩） 要求甚高，其整体性与强度的提高对大坝的稳定性至关重要。而欲达此目的，固结灌浆是重要手段。万家沟水库坝基（肩） 固结灌浆后，通过常规手段的测试表明，其整体性与强度已得到明显改善。     

Performance modification of a melt-blown filter medium via an additional nano-web layer prepared by electrospinning

A poly(acrylonitrile) (PAN) nano-web was electrospun on a commercial melt-blown poly(propylene) (PP) filter medium to generate composite filter media. The performance of these media was characterized in terms of filtration efficiency and pressure drop. Quality factors calculated from these parameters were used to evaluate the overall efficacy of the filter media. Structural characterization of the composite media showed that a thin layer of nano-web could improve the overall performance by increasing filtration efficiency without significant increase of pressure drop.