主动脉半周覆膜支架生物相容性及封堵效果的实验研究

目的探索自制主动脉半周覆膜支架置入犬主动脉后的组织相容性及对肾动脉开口的封堵效果。方法选用１５条健康杂种犬,自制主动脉半周覆膜支架规格为１６ｍｍ×６０ｍｍ、人工血管长度为４ｃｍ。经股动脉置入半周覆膜支架,随机封堵左或右侧肾动脉,尔后行主动脉造影及增强ＣＴ检查明确主动脉血流情况及肾脏供血情况。术后１,４,８,１２和１６周,随机选取３条犬复查主动脉造影及增强ＣＴ,随后处死、获取主动脉标本,分别对正常腹主动脉、裸支架处腹主动脉、覆膜支架处腹主动脉进行光镜及电镜的观察。结果１５条犬均成功地置入主动脉半周覆膜支架,分别封堵７条右肾动脉及８条左肾动脉,其余主动脉分支未受累。术中未发生血管破裂。主动脉造影及ＣＴ复查显示支架无移位,封堵肾动脉无血供,主动脉及其他分支血流正常。术后１６周正常腹主动脉、裸支架处腹主动脉、覆膜支架处腹主动脉内膜厚度分别为８５．７μｍ、９４３．１μｍ及２４８１．２μｍ,相应中膜厚度为１４０１．５μｍ、６１５．１μｍ及５９３．６μｍ,封堵侧肾脏缩小。结论自制主动脉半周覆膜支架的组织相容性及封堵效果良好。主动脉半周覆膜支架具有应用于临床病例的可行性。     

实验犬留置不同类型气管支架的基础研究

目的 探讨不同类型气管覆膜支架植入在实验动物中的应用价值.方法 健康成年杂种犬18只,随机平均分为3组,气管内留置不同类型支架,A组留置全覆膜支架(全长6 cm覆膜),B组留置中段覆膜支架(全长6 cm,上下两端各1 cm不覆膜,覆膜长度4 cm),C组留置裸支架(全长6 cm).术后观察动物进食、排痰、呼吸情况,饲养20周后分别处死.观察气管标本大体和HE镜下改变,并行增殖细胞核抗原(PCNA)染色,定量分析增生细胞的阳性表达.结果 各组实验犬均未发生支架留置后的急性呼吸困难,有轻至中度呛咳,经观察,排痰量并无明显差异.均可正常饮水、进食,发声无异常.部份犬活动减少.支架不覆膜处,气管内壁组织增生较明显,气管腔狭窄程度大于支架覆膜处.各组HE染色镜下均表现为炎性反应,低柱状上皮细胞鳞状化生、肉芽增生和纤维增生性改变.3组覆膜处与不覆膜处的黏膜增殖细胞阳性表达有显著的统计学差异(P＜0.05).不覆膜处的黏膜增殖细胞比率较高.结论 ①气管支架有无覆膜在留置的短期内对于进食、呼吸状况及痰液的排出无明显影响;②气管支架留置后,覆膜段气管内膜组织增生水平要小于不覆膜段;③气管支架留置后,覆膜段的黏膜增值细胞阳性表达小于不覆膜段.覆膜支架的生物相容性好.     

犬胸主动脉内分体式覆膜支架置入的实验研究

目的　 评价分体式覆膜支架置于犬胸主动脉内的技术可行性及支架的生物相容性。 方法 成年杂种犬１２只,随机分为３组,每组４只。切开右侧股动脉,经犬右侧股动脉将分体式覆膜支架置于犬胸主动脉内,且使外层移植物的近端至少接近左锁骨下动脉开口的远端,观察支架释放的技术可行性。按照实验分组分别于术后４、８和１２周血管造影复查分体式覆膜支架在犬胸主动脉内情况,后处死实验犬获取标本,大体观察及ＨＥ染色显微镜下观察支架与血管壁贴合情况、支架内面内膜化情况、血管壁病理变化等。结果 １０只犬成功置入分体式覆膜支架于胸主动脉内,释放顺利精确,无移位变形;１只犬因内支架输送系统进入时右侧股动脉撕裂出血而死亡,１只犬因外层支架移植物向前移位致升主动脉破裂立即死亡。术后４、８和１２周血管造影复查示支架位置及开放良好,支架无移位、变形、断裂、也未发生再狭窄。两端支架裸露部分４周时完全内膜化,支架移植物的内面４周起出现内膜化,随着时间的推移,内膜化逐渐明显,１２周时内膜基本覆盖支架移植物。 结论 分体式覆膜支架置于犬胸主动脉内,技术上可行,置入支架具有良好的生物相容性。     

颅内动脉瘤用纳米电纺覆膜支架初步实验研究

【摘要】 目的 动物实验研究评价新型颅内动脉瘤用纳米电纺覆膜支架的力学性能和生物相容性。方法 10只健康成年比格犬中共植入20枚纳米电纺覆膜支架,其中10枚0.10 mm丝径支架植入左侧锁骨下动脉（A组）,10枚0.15 mm丝径支架植入右侧锁骨下动脉（B组）。支架植入术后即刻和术后2、4、6周分别作血管造影随访。支架段血管作组织学病理检查,评价支架内皮化和内膜增生情况。结果 A组支架植入后即刻造影示7枚支架内漏,随访期间2枚支架内漏消失,5枚仍残留内漏;B组支架植入后即刻造影示1枚支架内漏,随访期间内漏消失,3枚支架发生轻度狭窄（狭窄程度＜50%）。组织病理学检查显示,B组术后2周血管壁呈慢性炎性反应,术后4周支架内表面部分血管内皮化,术后6周支架内表面基本实现血管内皮化。结论 本实验研究初步证明纳米电纺覆膜支架治疗颅内动脉瘤的有效性和可行性,具有重要临床应用价值。但该支架尚处于初始研究阶段,有待进一步远期观察和研究。

     

三种覆膜支架治疗犬颈动脉囊状动脉瘤的实验研究

目的探讨颅内覆膜支架治疗犬颈动脉囊状动脉瘤的可行性、安全性和疗效.方法采用外科手术方法在20只犬中建立犬颈动脉囊状动脉瘤模型36枚,应用血管内技术放置聚氨酯膜支架(PUM-SSS)、可膨胀聚四氟乙烯膜支架(ePTFEM-SSS)、生物膜支架(BM-SSS)各12枚,支架置入后即刻及术后2、4和12周分别进行血管造影随访,并进行组织病理学检查及统计学分析.结果 PUM-SSS、ePTFE-SSS和BM-SSS的完全开放率分别为25.0%、41.7%和91.7%,PUM-SSS、ePTFE-SSS分别和BM-     

食管支架在兔食管中的实验研究

目的观察金属支架在兔食管中的病理变化并对临床应用提出建议.方法对8只健康家兔食管内置于镍钛合金网状支架,分别于置入后2、4、6、8周造影观察;处死实验动物,观察食管组织学变化.结果内支架置入2周时,可见黏膜下灶性慢性炎症伴轻度水肿;4周,食管近支架上下两端处轻度狭窄,可见小息肉样赘生物为灶性慢性炎症伴炎性增生,支架口部黏膜过度增生,向腔内突起;6周时上述改变有不同程度加重,其中1只动物支架下端一侧嵌入食管壁使其局部增生,与主动脉粘连;8周组于7周末死于支架处食物团滞留梗阻.结论食管内支架再发狭窄的部位似乎     

犬肝内动脉覆膜支架置入的实验研究

目的从支架置入的成功率、贴壁性、支架内狭窄率及支架内皮化等诸方面探讨犬肝内动脉覆膜支架置入的可行性。方法成年毕格犬８只，全麻下采用介入技术在其肝右动脉／肝固有动脉内置入球囊扩张式可膨胀聚四氟乙烯（ePTFE）覆膜膜支架，置入后即刻及术后２、４和１２周行DSA复查，观察支架置入过程及其造影表现、标本的组织病理学表现，对参数进行统计学分析。结果支架均输送到位并顺利置入８只犬肝右动脉／肝固有动脉；支架释放后贴壁性能良好，所隔绝的动脉分支未显影；以管腔丢失＞５０％为明显狭窄标准，２周复查时有２只犬出现支架内明显狭窄，１２周复查时有３只犬出现支架内明显狭窄（３／８）。病理显示２只犬为血栓形成、１只犬为内膜增生所致；５只犬支架出现完全内皮化（标本３个不同取材部位均完全内皮化），３只犬支架内皮化不完全（标本３个取材部位至少有１处未内皮化）；支架两端较中央部更易形成内皮化；支架置入前后，所有犬肝功能均未出现显著改变。结论球囊扩张式覆膜膜支架能够顺利置入犬肝动脉，并且具有良好的贴壁性，能形成完整的内皮化，不会对肝功能带来影响。覆膜支架的犬肝内动脉置入是可行的。     

覆膜支架置入封堵治疗后动脉瘤形态学变化的实验研究

目的　　　研究颅内动脉瘤在使用覆膜支架治疗后的形态学变化。方法 使用５只实验犬建立双侧颈动脉侧壁动脉瘤模型１０枚,２周后使用覆膜支架对动脉瘤进行封堵治疗。分别于术前、术后即刻、术后２、４周行动脉瘤３．０ ＭＲ检查,观察动脉瘤形态学变化,术后４周将实验动物处死后行病理学研究。重点研究覆膜支架置入后不同时期动脉瘤体积的变化。统计软件使用ＳＡＳ６．１２。结果 ３．０ ＭＲ能够在Ｔ２像清楚显示动脉瘤形态。术前、术后即刻、术后２、４周动脉瘤瘤体积分别为（１００．１７ ± １６．６４）ｍｍ３,（９７．２５ ± １７．１８）ｍｍ３,（４４．１１ ± ５．９６）ｍｍ３和（３３．７５ ± ５．０２）ｍｍ３,支架置入后不同时间动脉瘤体积比较差异有统计学意义（χ２　＝　２２．２５４,　Ｐ　＜　０．０１）;术后２、４周动脉瘤体积较术前平均减小５５．６％,６６．２％;术后４周病理显示动脉瘤体完全纤维化。结论 动脉瘤在覆膜支架封堵治疗后体积能够明显缩小并最终完全纤维化,从而减轻其对周围结构的占位效应。     

覆膜支架治疗降胸主动脉瘤

目的评估覆膜支架治疗术治疗Stanford B型主动脉夹层和降主动脉瘤的安全性和近期疗效.方法2003年3月至2005年9月期间,共29例Stanford B型主动脉夹层和2例降胸主动脉瘤患者接受覆膜支架治疗术,所有患者均有高血压病史,其中急性发病27例.本组采用两种支架(Mdtronic Talent15例,上海微创Aegis 16例),术后采用CTA进行定期随访.结果所有支架均成功按预期定位释放,术后即刻DSA复查显示23例夹层患者近端破裂口完全封闭,2例降主动脉瘤也完全隔离,6例发现有内漏;术后7     

自制金属内支架的动物实验研究

目的:研究自制镍钛记忆合金内支架的生物相容性及通畅情况。方法:通过外科手术方式将自制镍钛记忆合金内支架放置于猪的胆管、动脉、静脉、气管中,于术后的一段时间内,处死实验动物,观察内支架的通畅情况。结果:11只胆道支架有6只完全阻塞,有5只支架部分通畅,且阻塞程度与时间有关;10/11只股动脉支架均显示通畅。仅1只支架完全阻塞;1/1静脉支架完全阻塞;4/8只气管支架通畅。4只支架表面取了脱落细胞检查,检查发现为上皮细胞。支架周边组织光镜检查:胆管、动脉、静脉、支气管支架共31只,镜检发现支架表面部分有上皮细胞覆盖,但主要为纤维结缔组织增生和支架所在组织的细胞增生。增生的组织细胞成分与支架植入后的时间长短有关,2周的动脉支架标本,在支架周围几乎未见结缔组织增生,随支架留置时间的延长,支架周围的结缔组织增生明显加重,且支架周围有淋巴组织增生。结论:国产金属内支架置入后,内皮细胞可覆盖到支架的表面上,而内膜增生的程度与支架的直径和放置部位的管径之比有关、与支架内流过物体的流量和流速有关、与支架放置的时间长短有关。选择好合适的内支架和置放部位,可使内支架狭窄产生的时间延长。     

Experimental study of a domestic thermoelectric cogeneration system

Thermoelectric application for power generation does not appear to be appealing due to the low conversion efficiency given by the current commercially available thermoelectric module. This drawback inhibits its wide application because of the overall low thermal efficiency delivered by typical thermoelectric applications. This paper presents an innovative domestic thermoelectric cogeneration system (TCS) which overcomes this barrier by using available heat sources in domestic environment to generate electricity and produce preheated water for home use. This system design integrates the thermoelectric cogeneration to the existing domestic boiler using a thermal cycle and enables the system to utilise the unconverted heat, which represents over 95% of the total absorbed heat, to preheat feed water for domestic boiler. The experimental study, based on a model scale prototype which consists of oriented designs of heat exchangers and system construction configurations. An introduction to the design and performance of heat exchangers has been given. A theoretical modelling for analysing the system performance has been established for a good understanding of the system performance at both the practical and theoretical level. Insight has also been shed onto the measurements of the parameters that characterise the system performance under steady heat input. Finally, the system performance including electric performance, thermal energy performance, hydraulic performance and dynamic thermal response are introduced.     

EC-MBR一体式反应器处理生活污水的试验研究

采用EC-MBR一体式反应器处理生活污水,运行结果表明:该工艺处理效率高,能源耗用降低。最佳反应条件为电流密度保持0.148 1 mA/cm~2,极板间距固定为40 mm,HRT=8 h,DO=2.5～3.5 mg/L,温度范围19～23℃,MLSS在4 000～5 200 mg/L,满足城镇污水处理厂污染物排放标准一级A标准。     

Experimental study on the effect of frost parameters on domestic refrigerator finned tube evaporator coils

In this study, parameters affecting the frost formation on the evaporator of a refrigerator and the structure of frost were examined. Air velocity measurements both at the air inlet and outlet channels of the evaporator were performed, and the effect of air velocity on frost formation was examined. The rate of evaporation of water inside the refrigerator cabin was also recorded.     

变容量家庭能源中心单独制热水模式的实验研究

提出了可全年供应空调和热水需要的变容量家庭能源中心系统,并提出单独制热水模式下的性能系数计算方法。通过对该模式瞬时动态特性的研究,指出变容量压缩机可以有效地保证机组的安全可靠运行。实验研究了单独制热水模式在不同环境温度、不同压缩机负荷条件下的性能。结果表明,在同一压缩机负荷条件下,热水性能系数均随环境温度的升高而升高,与传统热泵热水器的变化趋势相同。而压缩机负荷变化对机组热水性能系数的影响在不同的环境温度下呈现不同的规律,因此,可根据不同的环境温度优化控制压缩机负荷,以提高制热水效率,节约能源。     

Experimental and numerical study of a directly PV-assisted domestic hot water system

The solar domestic hot water (SDHW) system is the most highly developed system for use of solar energy. The developments for the thermal regulation of buildings should reinforce this trend given the significant reduction of heating needs. Currently, the design of these SDHW installations is well controlled and the system performance is reasonably good. The annual average solar fraction is consistent with expected level (between 60% and 70%) according to a report of CSTB by evaluating 120 SDHW installations (Buscarlet and Caccavelli, 2006). However, the control mode of conventional SDHWs induces additional costs related to the consumption of auxiliaries and other risks of dysfunction of the circulation pump due to the temperature probes and controller setup which induces low annual productivity of solar collector (200 instead of 400 kW h/m² expected). From this point of view, the photovoltaic pumped system seems suitable since it eliminates the controller and temperature sensors. This paper focuses on an experimental and numerical study of the behavior of a PV-SDHW system, focusing on the start-up phase optimized through various electronic devices. A detailed model of a circulation pump was developed by considering a direct current (DC) circulation pump coupled with various electronic devices (linear current booster and maximum power point tracker). The developed models were then validated experimentally, to reveal the influence of the threshold solar radiation on the circulation pump start-up and the pump flow rate as a function of the solar radiation, and its effects on the annual energy performance of PV-SDHW systems.     

Experimental study of new refrigerant mixtures to replace R12 in domestic refrigerators

An experimental study on the replacement of R12 in domestic refrigerators by new hydrocarbon/hydrofluorocarbon refrigerant mixtures has been carried out. Parameters and factors, affecting the performance characteristics of these refrigerants, based on experimental data have been compared to those of R12. The results show that butane/propane/R134a mixtures provide excellent performance parameters, such as coefficient of performance of refrigerator, compression power, volumetric efficiency, condenser duty, compressor discharge pressure and temperature, relative to a 210 g charge of R12. In addition, the results support the possibility of using butane/propane/R134a mixtures as an alternative to R12 in domestic refrigerators, without the necessity of changing the compressor lubricating oil used with R12.     

Experimental study of a domestic boiler using hydrogen methane blend and fuel-rich staged combustion

Storing excess wind and solar energy in the form of hydrogen injected into the natural gas grid is one of the main ingredients of the energy transition. This hydrogen injection has an impact on emissions and the performance of user equipment. The present work reports on an experimental study of the combustion of methane-hydrogen mixture with fuel rich transverse staggered injection. The 15 kW domestic boiler used was equipped with 16 burners (2 × 8). The aim of this work is to better understand the simultaneous effects of fuel rich staged combustion (Ø = 2.0 ÷ 4.0), hydrogen blending of methane (0 ÷ 45%) on pollutant emissions and efficiency while maintaining a compromise between high power, fuel economy and low emissions. The results show that NO_x, CO₂ emissions decrease, CO and C_xH_y emission values increase and thermal efficiency values decrease with increasing hydrogen percentage and fuel rich staggering combustion.     

蒸发式冷凝器应用于户式空调的实验研究

将蒸发式换热器应用到户式空调机组中，室内机走冷却水，减少了泄漏的可能性，室外机应用蒸发式换热器，提高机组效率。通过建立实验台，测试空调机组性能，研究了对蒸发式换热器热质交换的各种影响因素，确定了蒸发式换热器的最佳范围，供工程设计、选型和生产参考。     

家犬肝动脉热化疗的实验研究

目的观察家犬肝动脉灌注热化疗过程中的升温情况,心肺肾的耐受能力,以及术后肝脏的生化、组织学改变.方法使用自行设计的水浴式加温箱和输液泵.家犬10条,分为A、B两组,各5条,经肝动脉置管灌注化疗.A组灌注5%葡萄糖液(GS),液温43°C,时间30min,流量30ml/min;B组灌注热化疗液温45°C,时间30min,流量40ml/min,于5%GS液中加入丝裂霉素(MMC)按0.2mg/kg3条,加入顺铂(CDDP)按1mg/kg 2条.结果动物肛门温度比术前升高0.3～0.5°C,肝脏温度升高0.5～