18F?蛳 FDG PET/CT显像在索拉非尼治疗肝细胞癌预后评估中的应用

【摘要】 目的 探讨18F?蛳 FDG PET/CT显像评价索拉非尼治疗肝细胞癌预后的可行性。方法 分析2005年6月至2011年7月40例口服索拉非尼的中晚期HCC患者的临床资料,治疗前后行18F?蛳 FDG PET/CT检查,并记录每例患者肝内病灶区最大标准化摄取值（SUVmax）,评价其疗效,Cox模型分析影响总生存期（OS）和无肿瘤进展生存期（PFS）的因素。结果 40例患者随访中位时间9（2 ～ 18）个月,3例患者达到部分缓解,22例患者疾病稳定,总有效率为62.5%。中位生存期和PFS分别为6.1个月（95％CI:0 ~ 12）和4.8个月（95％CI:1.4 ~ 7.2）。多因素分析显示,ECOG评分,甲胎蛋白（AFP）水平,门静脉主干癌栓和SUVmax是影响OS独立预后因素。AFP水平和SUVmax是影响PFS独立预后因素。根据SUVmax最佳临界值将患者分为低SUVmax值和高SUVmax值两组:低SUV组的OS和PFS明显大于高SUV组（P分别为0.009和0.003）。结论 索拉非尼治疗进展期HCC,18F?蛳 FDG PET/CT显像的SUVmax有价值的预后因素之一。     

磁共振弥散加权成像在125I粒子组织间植入治疗胰腺癌疗效评估中的应用

【摘要】 目的 探讨磁共振（MRI）弥散加权（DWI）成像对125I粒子组织间植入治疗人胰腺癌裸鼠移植瘤疗效的评估价值。方法 将人胰腺癌SW1990细胞株接种于BABL/C裸鼠右下肢旁腹股沟区偏背侧皮下,待瘤体长至8 ～ 10 mm进行干预,共有16只裸鼠的成瘤大小适用于实验,分为实验组8只,植入125I粒子,和对照组8只,植入空载粒子。粒子植入前及治疗后2周和2个月时分别行MRI常规扫描及DWI成像。取瘤体标本行组织病理学检查。结果 实验组肿瘤细胞坏死明显,而对照组肿瘤细胞无明显或有少许坏死。裸鼠心、肝、肺、肾及脾脏等组织无明显放射炎症表现。常规MRI成像评价125I粒子治疗胰腺癌疗效的价值有限。DWI显示实验组内整个肿瘤组织的表观弥散系数（ADC）值在治疗前为（0.001 15 ± 0.000 13） mm2/s,治疗后2周为（0.001 29 ± 0.000 038） mm2/s,治疗后2个月为（0.002 08 ± 0.000 14 ）mm2/s,与治疗前相比差异有统计学意义（P < 0.05）。实验组肿瘤实质区的ADC值亦较治疗前及对照组增高,但低于坏死区ADC值。结论 125I粒子组织间植入治疗人胰腺癌裸鼠移植瘤可导致肿瘤坏死,并对周围脏器是安全的。用常规MRI及DWI成像观察裸鼠皮下移植瘤可行。DWI对疗效评估有重要价值。
     

125I粒子持续照射对Sw1990及Panc?蛳 1细胞 生物学效应的影响

【摘要】 目的 采用125I粒子对胰腺癌细胞Sw1990及Panc?蛳 1行体外持续照射，研究其生物学效应，探讨连续照射对胰腺癌细胞增殖、DNA合成、细胞周期及凋亡的影响，并为胰腺癌放射实验细胞的选择提供参考。方法 将胰腺癌细胞Sw1990及Panc?蛳 1体外培养至对数生长期，行125I粒子持续照射，在初始剂量率为12.13 cGy/h 时，分别给予总剂量为0、2、4、6、8 Gy的照射，采用克隆形成实验检测照射后细胞的增殖能力，绘制生存曲线，计算细胞存活率（SF2），检测细胞凋亡率和细胞周期，以及3H?蛳 TDR掺入实验探究照射后细胞DNA合成情况。结果 经过拟合，计算出Sw1990和Panc?蛳 1细胞的SF2值分别为0.766 ± 0.063和0.729 ± 0.045，随着照射剂量增高，两种细胞凋亡率也逐渐升高，Panc?蛳 1细胞的最大凋亡率出现在6 Gy，Sw1990出现在8 Gy。G2/M期阻滞分数均逐渐升高，3H?蛳 TDR掺入放射量逐渐降低。结论 125I持续照射胰腺癌细胞时，细胞凋亡及G2/M期阻滞是抑制细胞增殖的主要原因，在剂量为0、2、4、6、8 Gy时，Sw1990及Panc?蛳 1细胞生物学效应差异无统计学意义。

     

18F-FDG PET/CT显像在肝细胞癌TACE术后残留或复发病灶检出中的应用价值

【摘要】 目的 探讨18F?蛳 FDG PET/CT显像在肝细胞癌（HCC）TACE术后残留或复发病灶检出中的应用价值。方法 收集23例经TACE治疗后HCC残留或复发患者临床及PET/CT检查资料,患者均于TACE治疗后1.5 ~ 7个月行全身18F?蛳 FDG PET/CT显像,1周内行DSA造影并接受介入治疗。重点评价2种检查方法对肿瘤残留或复发的显示能力。结果 全组23例患者均顺利完成PET/CT显像检查及DSA造影检查。DSA造影证实肝内肿瘤残留或复发灶46个,PET/CT显像检出肝内肿瘤残留或复发灶共45个。以DSA作为参考标准,PET/CT显示肿瘤残留或复发灶的灵敏度为97.8%（45/46）,特异度为100%,准确率为97.9%（46/47）;PET/CT与DSA检出肿瘤残留或复发灶的结果比较差异无统计学意义 （P > 0.05）;两者检出肿瘤灶的吻合度差异有统计学意义,且吻合度较强（系数k = 0.657,P = 0.000）。另外,18F?蛳FDG PET/CT全身显像新发现肝外转移3例,其中双肺转移1例,右侧肾上腺及肝门区、腹膜后区淋巴结转移1例,左髂骨转移1例。结论 18F?蛳 FDG PET/CT显像能够准确、直观地显示经TACE治疗后HCC残留或复发病灶,且真实性和可靠性好;同时18F?蛳 FDG PET/CT全身显像检查是肿瘤远处转移探测最有效的方法,可较全面评估患者病情,协助临床确定个体化治疗方案具有重要价值。
     

能谱CT早期评价125I粒子植入治疗胰腺癌效果实验研究

【摘要】 目的 探讨能谱CT成像早期评价125I粒子组织间植入治疗胰腺癌效果的应用价值。方法 人原位胰腺癌BxPC-3细胞株接种于16只BABL/c裸鼠四肢偏背侧皮下，成瘤1～1.5 cm；分别植入125I粒子（实验组，n=8）和空载粒子（对照组，n=8），2周后行能谱CT平扫及多期相（10 s、25 s、60 s）增强扫描，获取多期相系列图像。测量瘤体对比噪声比（CNR）和碘浓度（IC），得出瘤体标准化碘浓度（nIC）。瘤体免疫组化染色后，分析瘤体组织内微血管密度（MVD），nIC与MVD相关性。结果 实验组各期相（10 s、25 s、60 s）瘤体nIC值均低于对照组，差异有统计学意义（P＜0.05）；实验组MVD计数低于对照组，差异有显著统计学意义（t=5.957，P＜0.01）；各期相nIC与MVD均存在正线性相关（分别为r=0.63，P＜0.000 1；r=0.51，P=0.002；r=0.48，P=0.001 7）。结论 能谱CT是监测125I粒子组织间植入治疗胰腺癌效果的有效方法。

     

125Ｉ放射性粒子组织间植入治疗人胰腺癌裸鼠移植瘤的有效性研究

目的 探讨１２５Ｉ放射性粒子组织间植入治疗人胰腺癌裸鼠移植瘤的疗效及其作用机制。方法 人胰腺癌ＳＷ１９９０细胞株接种于ＢＡＢＬ／ｃ裸鼠右下肢旁腹股沟区偏背侧皮下,成瘤后取瘤块接种,６周后成瘤８ ～ １０ ｍｍ。共１６只成瘤大小合适的裸鼠用于实验,分别植入１２５Ｉ粒子（８只）和空载粒子（８只）。粒子植入后,每４天测量肿瘤的长径和短径并称裸鼠体重,裸鼠处死后称量瘤体重。瘤体标本行组织病理学检查、末端脱氧核苷酸转移酶 生物素ｄＵＴＰ切口末端标记法（ＴＵＮＥＬ）检测凋亡细胞及免疫组化染色检测增殖细胞核抗原。结果 １２５Ｉ粒子治疗组肿瘤体积增长缓慢,而对照组肿瘤体积增长迅速。实验组和对照组瘤体重分别约（２．６８ ± ０．７０）ｇ和（４．６８ ± １．４５）ｇ,两者的差异有统计学意义（Ｐ ＝ ０．０２１）;抑瘤率约４２．６６％。粒子植入前、后实验组和对照组间裸鼠体重对比差异无统计学意义（Ｐ ＞ ０．０５）。治疗组肿瘤细胞坏死明显,而对照组肿瘤细胞无明显或仅有少许坏死。ＴＵＥＮＬ法检查发现实验组和对照组的凋亡指数分别为（２３．２ ± １．９）％和（８．１ ± １．５）％,两者的差异有统计学意义（Ｐ ＜ ０．０１）。免疫组化染色发现:实验组及对照组增殖细胞核抗原（ＰＣＮＡ）阳性染色指数分别为（４９．８ ± １．８）％和（８２．２ ± ２．４）％,两者的差异有统计学意义（Ｐ ＜ ０．０１）。裸鼠心、肝、肺、肾及脾脏等组织无明显放射性炎症表现。结论 １２５Ｉ粒子组织间植入治疗人胰腺癌裸鼠移植瘤是有效的,其作用机制包括:直接杀伤肿瘤细胞、诱导肿瘤细胞凋亡及降低细胞增殖,并且１２５Ｉ粒子植入瘤体内对周围脏器是安全的。     

3D打印共面模板在胰腺癌125I粒子植入治疗中的初步应用

【摘要】 目的 评估3D打印共面模板在胰腺癌125I粒子植入治疗中的临床应用价值。方法 回顾性分析2016年1月至2017年6月行3D打印共面模板引导胰腺癌125I粒子植入治疗患者10例。术前根据CT扫描结果和治疗计划系统,制备3D打印共面模板,术中在该模板引导下进行穿刺和植入粒子,术后对剂量学参数进行验证。观察治疗前后90%靶区体积的剂量（D90）、90%处方剂量的靶区体积（V90）、100%处方剂量的靶区体积（V100）、150%处方剂量的靶区体积（V150）。评估3D打印共面模板引导下胰腺癌125I粒子植入穿刺定位的成功率,治疗后剂量学参数与术前计划的吻合度和并发症发生率。结果 10例胰腺癌患者在共面模板引导下均成功穿刺和植入125I粒子。术后剂量学参数D90符合术前计划,治疗前后D90差异较小且无统计学意义（P>0.05）,术后V90、V100和V150分别为（94.3±2.4）%、（90.4±4.1）%和（62.1±13.4）%,符合治疗剂量学要求。1例患者术后出现局部血肿。结论 3D打印共面模板是一种安全、有效的引导工具,有助于胰腺癌125I粒子精准植入,可使术后剂量参数符合术前计划要求。
     

125I粒子串近程放射治疗兔植入性门静脉主干癌栓实验研究

【摘要】 目的 评估125I粒子串近程放射治疗兔植入性门静脉主干癌栓（MPVTT）的安全性和有效性。方法 对32只新西兰大白兔门静脉主干植入VX2肿瘤细胞株,随机分为治疗组（T组,n=16）和对照组（C组,n=16）。治疗组、对照组兔MPVTT中分别植入125I粒子串、无放射性粒子串,术后定期监测兔一般情况、体重、实验室检查变化,术后2周治疗组、对照组各处死8只兔,作病理学检查。余下兔饲养至死亡作尸检,对比两组多层螺旋CT检查结果、组织病理学检查结果、Ki- 67标记指数、凋亡指数,并以此为基础评估该疗法的有效性。结果 近程放射治疗后每个观察时间点均表明,对照组兔体重下降更加明显,两组兔肝功能、血细胞计数差异均无统计学意义（P＞0.05）。治疗组、对照组平均MPVTT体积为分别为（565.4±220.9） mm3、（2 269.9±437.0） mm3,差异有显著统计学意义（P＜0.001）;Ki- 67蛋白指数分别为（4.14± 1.84）%、（33.82±6.07）%,凋亡指数分别为（6.51±1.92）%、（0.91±0.26）%,差异均有显著统计学意义（P=0.001）;平均生存时间分别为（39.50±2.37） d、（27.38±1.22） d, 差异有显著统计学意义（P=0.001）。结论125I粒子串近程放射治疗兔植入性MPVTT安全有效。
     

CT引导下放射性125I粒子植入治疗肾上腺转移瘤的近期疗效观察

【摘要】 目的 评价CT引导下放射性125I粒子植入治疗肾上腺转移瘤的近期疗效及安全性。方法 对2014年8月至2015年4月收治的18例肾上腺转移瘤行CT引导下放射性125I粒子植入治疗的患者进行回顾性分析,术前明确诊断,可评价病灶19处,病灶最大径为4~7 cm,平均（5.55±0.79） cm。应用治疗计划系统（TPS）三维粒子植入制定治疗计划,在CT引导下植入放射性125I粒子,于治疗后6~8周随访观察客观缓解率,按照WHO实体肿瘤评价标准评价病灶。结果 术后6~8周随访,评价病灶完全缓解（CR）5/19,部分缓解（PR）11/19,疾病稳定（SD）3/19,疾病进展（PD）0/19。所有患者术中、术后均未出现严重并发症,如恶性高血压、大出血,肾脏、肺、胰腺等周围脏器损伤等。结论 CT引导下放射性125I粒子植入治疗肾上腺转移瘤是一种安全有效的介入微创治疗手段。
     

不同活度125I粒子植入抑制兔VX2肝癌机制研究

【摘要】 目的 探讨125I粒子组织间植入诱导肝癌细胞凋亡的机制。比较不同活度125I粒子组织间植入诱导肿瘤细胞凋亡、抑制肿瘤细胞增殖的作用强度。方法 将24只兔VX2肝癌模型随机分为3组,分别植入不同初始活度的125I粒子:0 mCi组（对照组,n=8）、0.7 mCi组（n=8）及1.0 mCi组（n=8）。5周后处死实验兔,取出肿瘤病灶,检测125I粒子对肿瘤细胞凋亡、肿瘤生长相关因子表达的影响及caspase 3 活性改变。结果 不同初始活度125I粒子均可使肿瘤细胞凋亡率上升, Bcl 2、VEGF表达下调,Bax表达上调,1.0 mCi 125I粒子组作用均更加明显（P＜0.05）。不同初始活度125I粒子可增加肿瘤组织中caspase 3活性,两治疗组间差异无明显统计学意义（P＞0.05）。结论 125I粒子植入后不仅通过诱导肿瘤细胞凋亡抑制肿瘤生长、增殖,还影响凋亡相关基因及编码蛋白表达,抑制肿瘤细胞新生血管生成。     

Stability of LaNi5−xSnx cycled in hydrogen

In this work we study the effect of cycling in hydrogen with a purity grade 4.5 of six alloys belonging to the LaNi_5−xSn_x family for 0 ≤ x ≤ 0.5. Measurements consist in the alternate repetition of absorption reactions at a temperature of 316 K and an initial pressure of 800 kPa, each followed by a desorption reaction at the same temperature and a maximum backpressure of 2 kPa. All samples present good stability, preserving at least 98% of their initial capacity after 100 cycles. Samples with composition LaNi₅ and LaNi_4.55Sn_0.45 were subjected to 1000 cycles, after which we observe a higher stability from the Sn-containing alloy (96% of the initial capacity preserved versus 92% for LaNi₅). Absorption characteristic times do not suffer important changes in either case. Desorption is gradually retarded when Sn content is higher than 0.4 at.     

Preferential oxidation of carbon monoxide in simulated reformatted gas over PtAu/CexZnyO2 catalysts

A series of Pt–Au catalysts prepared by co-precipitation (CP) and single step sol-gel (SSG) methods was investigated for selective CO oxidation. The characteristics of the prepared catalysts were determined by XRD, BET surface area, SEM, H₂-TPR, chemisorption analysis, and FTIR. The simulated reformatted gas consisted of 1% CO, 1% O₂, 0% to 10% H₂O, 0–20% CO₂, and 40% H₂ in He balance. The operating temperature range was varied from 50 °C to 190 °C at atmospheric pressure. The experimental results elucidated that the catalytic preparation method had a significant effect on the catalyst characteristics and its activity. The catalytic performance over PtAu/Ce₁Zn₁O₂ prepared by co-precipitation was higher than that of PtAu/CeO₂ and PtAu/ZnO because of the incorporation of Ce⁴⁺ ions and the Zn²⁺ ions in the lattice. To encourage better catalytic performance, the catalysts should be calcined at 500 °C for 5 h and pretreated in a H₂ atmosphere. The CO conversion for the single- and double-stage reaction was reduced when adding water vapor and CO₂ to the feedstream; the water vapor and CO₂ molecules compete for the adsorption with CO on the active sites of the catalysts. During the deactivation test for 60 h, the CO conversion and selectivity are maintained.     

Initiation of spherical detonation in hydrogenair

Spherical detonation has been initiated in a range of mixtures of hydrogen and air, at one atmosphere initial pressure, by Tetryl charges of mass (0.78–2.40) × 10^?3 kg. The results are in accordance with an earlier experiment by Cassut but contrary to a recent prediction of Lee. A theoretical model embracing the full kinetic scheme for hydrogen oxidation fits the experimental detonability data and predicts the variation of detonability with concentration over a much wider range. An important conclusion from the model study is that it predicts for the first time for spherical detonation the existence of concentration limits to detonability. A kinetic explanation is offered for these limits which are approximately 13–70% v hydrogen in air.     

Study of the Li-insertion/extraction process in LiFePO4/FePO4

The structural properties of LiFePO₄ prepared by the hydrothermal route and chemically delithiated have been studied using analytical electron microscopy and Raman spectroscopy. High-resolution transmission electron microscopy and selected area electron diffraction measurements indicate that the partially delithiated particles include LiFePO₄ regions with cross-sections of finite size along the ac-plane, as a result of tilt grain boundary in the bc-plane, and dislocations in other directions. Only the boundary along the bc-plane is accompanied by a disorder over about 2 nm on each side of the boundary. The Raman spectrum shows the existence of both LiFePO₄ and FePO₄ phases in the shell of the particles at a delithiation degree of 50%, which invalidates the core–shell model. This result also invalidates the recent model according to which each particle would be single-domain, i.e. either a LiFePO₄ particle or a FePO₄ particle. On the other hand, our results, like prior ones, can be understood within the framework of a model similar to the spinodal decomposition of a two-phase system, which is discussed within the framework of morphogenesis of patterns in systems at equilibrium. Both end-members, however, are well crystallized, suggesting a recovery similar to that observed in superplastic alloys, with dynamics that are due to the motion of nucleation fronts and dislocations, and not due to a diffusion phenomenon associated with a concentration gradient.     

Dynamic modeling of a hybrid wind/solar/hydro microgrid in EMTP/ATP

Microgrids are LV or MV electric networks which utilize various distributed generators (DG) to serve local loads. In this paper, dynamic models of the main distributed generators including photovoltaic (PV) cell, wind turbine, hydro turbine as well as the equivalent power electronic interfaces, battery unit of PV and excitation system of hydro turbine have been made in ElectroMagnetic Transient Program/Alternative Transient Program (EMTP/ATP) software package. Control strategies based on active power/frequency and reactive power/voltage droops for the power control of the inverters have been also developed. Case studies have been carried out in a distribution network to investigate the dynamic behavior of the micro-sources in both steady state and fault scenarios. Simulation results verify the feasibility of the proposed models.     

Understanding the electrocatalytic activity of PtxSny in direct ethanol fuel cells

In the present work, the activity of Pt_xSn_y/C catalysts towards ethanol, acetaldehyde and acetic acid electrooxidation reactions is investigated for each one separately by means of cyclic voltammetry. To this purpose, a series of Pt_xSn_y/C catalysts with different atomic ratio (x:y = 2:1, 3:2, 1:1) and small particle size (∼3 nm) are fast synthesized by using the pulse microwave assisted polyol method. The catalysts are well dispersed over the carbon support based on the physicochemical characterization by means of XRD and TEM. Concerning the ethanol electrooxidation, it is found that the Sn addition strongly enhances Pt's electrocatalytic activity and the contributing effect of Sn depends on: (i) the Sn content and (ii) the operating temperature. More precisely, at lower temperatures, Sn-rich catalysts exhibit better ethanol electrooxidation performance while at higher temperatures Sn-poor catalysts give better performance. In the case of acetaldehyde electrooxidation, Pt₁Sn₁/C catalyst exhibits the highest activity at all the investigated temperatures; due to the role of Sn, which could effectively remove C₂ species and inhibit the poison formation by supplying oxygen-containing species. Finally, it is found that the Pt_xSn_y/C catalysts are almost inactive (little current was measured) towards the acetic acid electrooxidation. The above findings indicate that Sn cannot substantially promote the electrooxidation of acetic acid to C₁ species.     

The solubility of Ni in molten Li2CO3–Na2CO3 (52/48) in H2/H2O/CO2 atmosphere

In this work the solubility of a Ni–Al anode for MCFC has been studied at atmospheric pressure and two different temperatures using various gas compositions containing H₂/H₂O/CO₂. It is well known that nickel is dissolved at cathode conditions in an MCFC. However, the results in this study show that nickel can be dissolved also at the anode, indicating that the solubility increases with increasing CO₂ partial pressure of the inlet gas and decreasing with increasing temperature. This agrees with the results found by other authors concerning the solubility of NiO at cathode conditions. The dissolution of Ni into the melt can proceed in two ways, either by the reduction of water or by the reduction of carbon dioxide.     

Enhanced photoelectrochemical response of reduced-graphene oxide/Zn1−xAgxO nanocomposite in visible-light region

Graphene based nanocomposites have the potential to work as efficiently, multifunctional materials for energy conversion & storage. These composites may exhibit better photocatalytic properties by the improvement of their electronic and structural properties than pure photocatalysts. In the present work, reduced graphene oxide (rGO) & ZnO nanocomposite with 0–5 atom% Ag doping was prepared by electrodeposition method and characterized by XRD, Raman spectroscopy, FE-SEM, EDX, UV–Vis spectroscopy and final photoelectrochemical activity was assessed under 1.5 AM solar simulator in 1 M NaOH as electrolyte. Significant changes in the Raman spectrum for the nanocomposite suggest the possible electronic interaction between rGO and ZnO nanocomposite and its successful fabrication, which improves the charge separation and enhanced photoelectrochemical activity in the nanocomposite. We find a red-shift of 0.35 eV in the UV–vis spectrum and therefore an enhanced photoelectrochemical activity in the visible range on Ag doping in rGO/ZnO nanocomposite. Nanocomposite with 1 atom% Ag doping showed the highest photocurrent density of 2.48 mA/cm² at 0.8 V vs Ag/AgCl over other samples, which was almost five times higher than that for undoped rGO/ZnO composite. Calculated Flat-band potential and donor densities using Mott–Schottky data also supported the better photoelectrochemical response for Ag doping in nanocomposite.     

Pre-existence of HxWO3 in e-beam deposited WO3 films

Structural and optical properties of e-beam deposited tungsten trioxide (WO₃) films in as-deposited and electrochemically coloured states were investigated by spectrophotometric and XRD techniques. These investigations have shown the as-deposited WO₃ films to be porous and with small amount of H_xWO₃ pre-existing in them. The films further facilitate insertion of H⁺ ions on colouration resulting in tetragonal H_xWO₃ with a = 4.74Å and c = 3.19Å.