Hyperthermia by a nitinol stent in an alternating magnetic field:Safety and feasibility in rabbit esophageal cancer

Hyperthermia by heating in-stent is a potentially new method to treat esophageal cancer.This study assessed the safety of heating the rabbit esophagus with a nitinol stent in an alternating magnetic field (AMF) and investigated whether this method offers a therapeutic option for esophageal cancer.Nitinol stents were placed in the cervical esophagi of healthy rabbits,which were heated in an AMF for different times at 43,46 and 50 ℃.The esophagi were histologically examined after a week to observe whether there was transmural necroses.Then esophageal cancer of rabbit placed nitinol stents were heated in an AMF at 46℃ for 10 min.Stents were heated to a target temperature within 5 min.The highest tolerated temperature and time for the healthy rabbit esophagus was at 46℃ for 10 min.Tumor growth was delayed by heating and it was statistically significant.Heating the rabbit esophageal wall at 46℃ for 10 min proves to be safe and effective in delaying tumor growth.     

Assessment of alternated cooling and heating treatment by US combined CEUS in the VX2 rabbit liver tumor model

Inoperable liver tumors are often treated by thermal ablation that destroys the tumor in situ and spares the adjacent hepatic tissue.Thermal–physical treatment has many advantages,but treatment by freezing or heating alone has some limitations.By taking the advantages and disadvantages of cryosurgery and thermotherapy into consideration,a new thermal technique that combines cryosurgery and radio frequency ablation has been proposed,thereby overcoming the disadvantages of each treatment strategy and improving therapeutic outcomes.This new approach remains to be systematically studied in the liver;therefore,this study was performed to estimate survival after alternated cooling and heating ablation therapy in a VX2 rabbit liver tumor model.Sixteen days after VX2 carcinoma implantation into the rabbit liver,tumors were treated with alternated cooling and heating ablation therapy.Rabbits were monitored for 6 months after treatment and assessed with ultrasound(US)and computed tomography at 1,7,14,and 30 days posttreatment.Untreated tumor-bearing animals served as the control group.Our results show that alternate freezing and heating ablation therapy resulted in a good recovery of VX2 rabbits.Compared with the control group,treated rabbits lived significantly longer(P\0.05),with 70%of treated animals surviving to 196 days posttreatment without metastasis or recurrence,while none of the controls did so.There was no local recurrence in the treatment group.All rabbits in the control group developed metastasis,while metastasis was only observed in 30% of treated rabbits.These results suggest that alternate cooling and heating ablation therapy can prolong the survival time of rabbits with VX2 liver tumors and is an effective method for tumor therapy.Furthermore,we also showed in this model that contrast enhanced US is a valid follow-up approach to assess treatment effectiveness.     

肿瘤热疗用交变磁场发生器的研制

装置的磁路部分设计成环回形,磁路中的气隙用于产生高频磁场.在励磁线圈中加入铁氧体磁芯显著增强了装置输出的磁场强度;电路部分采用桥式拓扑结构,因而功率变换效率很高.装置的指标为:频率25～120 kHz,磁场强度6～16 kA/m.对磁场强度的测量表明磁场分布均一.使用该装置加热纳米磁性材料,可使其在室温下升温达28 ℃.这些工作为磁流体肿瘤热疗的临床应用提供了参考.     

DSA 联合 CT 引导下经皮肝穿刺兔 VX2 肝癌模型制作

摘要: 目的 探讨 DSA 联合 CT 引导下经皮肝穿刺兔 VX2 肝癌模型制作的可行性。方法 40 只新西兰白兔随机分 成 A、B 两组,每组 20 只,A 组在 DSA 联合 CT 引导下将兔 VX2 肿瘤组织块经皮肝穿刺接种于兔左肝内,B 组通过 开腹法种植 VX2 肿瘤组织块,于接种后第 2 周、4 周行全身 MR 检查,后处死实验兔行原位、异位肿瘤肉眼观察。结 果 A 组建模成功率 90% ,有 1 只出现异位种植,未发现腹水及死亡,平均手术时间( 17. 3 ± 5. 2) min; B 组建模成 功率 85% ,有 3 只出现腹水,2 只死亡,无异位种植发生,平均手术时间( 50. 7 ± 11. 3) min,,两组手术时间比较差异 有统计学意义( P ＜ 0. 05) 。结论 DSA 联合 CT 引导下经皮肝穿刺制作兔 VX2 肝癌模型方法简单、建模成功率高、 手术操作时间短。     

磁流体热疗设备的三维电磁场模拟

为清楚了解磁流体热疗设备产生的电磁场的分布,本文采用有限元方法对自制的设备原型建立三维模型并进行了优化,计算了该模型在静态和谐态下产生的电磁场的分布,对磁极中间的气隙宽度在20～40mm范围内变化时的磁场强度进行了对比．选取气隙宽度为30mm时计算电磁场的磁场强度、电感和涡流损耗,所得结果与实验测量值完全吻合,验证了模拟计算的可靠性．     

关于磨料磁流体射流可行性的分析

通过对前混合磨料射流和后混合磨料射流进行对比分析,发现了两种磨料射流技术均存在一些技术缺陷。为了解决这些问题,对磁流体推进技术展开研究。通过Fluent软件对磁流体中磨料运动进行分析;并且通过试验装置验证了直流式磁流体推进装置能够对磁流体产生增压效应,形成了直流式磨料磁流体射流。在直流式的基础上,分析了交流式磨料磁流体射流的优点,展望了交流式磁流体推进技术在磨料磁流体射流上的应用前景。通过电磁场方程以及流场方程建立数学模型,分析了其在磨料射流上应用的可能性。     

全身化疗联用TNF,IL—2胸腔内注射治疗恶性胸水30例临床观察

肺癌患者胸腔内反复大量积液在临床上治疗较为棘手,手术、放疗、化疗疗效均不理想。本文采用全身化疗联合ＴＮＦ和ＩＬ－２胸腔内注射治疗肺癌恶性胸水３０例,其中腺癌１９例,鳞癌９例,小细胞未分化癌２例,平均年龄５１岁;对照组２８例,腺癌１５例,鳞癌１２例,小细胞未分化癌１例,平均年龄５５岁。方法：治疗组所有病例均先行全身化疗,化疗结束后胸腔抽液,尽可能抽尽胸水后胸腔注入ＴＮＦ１０万Ｕ、ＩＬ２２万Ｕ,每周２次,连续４～６次。对照组全身化疗同前,胸腔局部不用ＴＮＦ及ＩＬ－２。根据患者气急、胸闷、胸痛等症状、体征变化,胸片、Ｂ超检查结果评定疗效。结果：治疗组２０例显效、７例有效、３例无效,总有效率９０％（２７／３０）;对照组６例显效、８例有效、１４例无效,总有效率５０％（１４／２８）,二者相比有显著性差异（Ｐ＜００５）。此法副作用小,胸腔注射ＴＮＦ、ＩＬ－２后有６例出现轻微胸痛和低热,２例在注药１ｈ内出现寒战、高热（后自行缓解）,未见其它严重副反应出现,结论：上述疗法是治疗肺癌恶性胸水有效的方法     

MPCVD 法工艺特性对 SnO_2 薄膜导电性的影响

研究了磁等离子体化学气相沉积的不同工艺条件对ＳｎＯ２薄膜导电性的影响．实验结果表明,外加适当位形、大小的纵向磁镜场,可使等离子体化学气相沉积技术中制备ＳｎＯ２薄膜所需的氧气流量降低,沉积时间缩短,且制得的薄膜电阻大大降低,轴向分布均匀性明显增强．对以上结果进行了分析和讨论．     

基于大别造山带电磁测深数据的磁暴感应地电场分布特性分析

为探明磁暴期间大别造山带的地面感应电场分布特性,通过引入大别造山带的大地电磁测深数据,结合2004年11月7—9日强磁暴期间武汉地磁台站的秒级磁场数据,进而计算磁暴感应地电场的方法研究了磁暴期间地面感应电场频域下的电场强度幅值最大值及对应的频率分布.结果表明:磁暴期间频域下电场强度幅值分布不均匀,而且部分数值较大;频域...     

Ti或TiN的添加对MoS2基复合薄膜耐磨性能的影响

为改进纯MoS2薄膜在大气环境下极易氧化失效且耐磨损性能较差的缺点,采用非平衡纳米复合等离子体镀膜技术合成了MoS2基薄膜, 该薄膜由Ti或TiN与MoS2共沉积而成.采用扫描电子显微镜、干钻削和车削实验确定薄膜的结构、成份和机械性能.结果显示, 在潮湿和超低温环境下,薄膜具有优异的耐磨寿命和抗氧化性.实验表明, 改进后的MoS2基复合薄膜在机加和成型等领域中具有广泛的应用前景.