~(32)P持续照射对HeLa细胞周期影响规律的研究

研究3 2 P照射体外培养HeLa细胞细胞周期影响特点 ,以探索肿瘤核素治疗放射生物学机制。采用人宫颈癌HeLa细胞系体外培养 ,制作3 2 P放射性贴片照射细胞 ,通过观察照射后细胞周期再分布 ,研究不同剂量、剂量率、照射时间细胞放射效应特点。结果表明 ,照射后G2期阻滞为剂量依赖性 ,但阻滞达峰值后 ,随照射时间延长 ,累积剂量增加阻滞程度不再增加 ,有坪值 ,其大小与剂量率有关 ;G2期阻滞峰值的时间均为 2 4h左右 ,2 4— 32h之后下降。结果提示 ,3 2 P放射性贴片照射HeLa细胞 ,照射后细胞表现为G2期阻滞 ,阻滞程度与剂量相关 ,G2期阻滞达峰值的时间与细胞周期内在属性相关 ,与剂量、照射时间无关。     

不同剂量、剂量率32P照射下HeLa细胞发生凋亡及其与细胞杀伤效应的关系

研究了放射性核素^32P照射HeLa细胞,在不同剂量、剂量率条件下凋亡的发生,以及凋亡与杀伤效果的关系。用^32P放射性贴片照射细胞,观察照射后细胞凋亡、增殖能力变化、细胞周期再分布,研究不同剂量、剂量率、照射时间时细胞放射响应的特点,用荧光显微镜观察调亡细胞形态学特点,并进行漂浮细胞凋亡定量分析;流式细胞仪调亡定量分析及平行检测细胞周期变化;电镜观察凋亡亚细胞形态学特点;克隆形成率和细胞群体培增大小,评价肿瘤细胞增殖能力。结果显示,在研究剂量范围内,HeLa细胞死亡的主要方式为凋亡,主要发生在照射后48－72h,随G2期阻滞的下降,凋亡率逐渐增加。单次照射与分次照射的比较显示,前者凋亡率高于分次照射,与克隆形成率不一致,提示,在不同照射方式下,某一时间点的凋亡率尚不能作为一个可靠的指标反映放射敏感性及肿瘤杀伤效果。     

低剂量X射线照射诱导HeLa细胞存活的

采用集落形成法观察了低剂量X射线照射HeLa细胞的存活率，结果表明，小于0．5Gy的X射线照射细胞的存活率高于对照，得到了HeLa细胞存活的“兴奋效应”，而且在0．25Gy附近这种效应更为明显；低剂量D1（0．05，0．75Gy)的预照射降低了随后攻击量D2对细胞的损伤程度，反映出低剂量照射可诱发细胞存活的“适应性反应”。     

^90Y,^32P—GTMS介入治疗恶性肿瘤的实验研究与初步临床应用

采用介入治疗法，将＾９０Ｙ－ＧＴＭＳ和＾３２Ｐ－ＧＴＭＳ直接注入癌性肿块中，以达到杀灭癌细胞、抑制肿瘤生长、延长恶性肿瘤患者生存期的目的。在荷瘤裸鼠模型的瘤体上进行对照组、“冷”球组、不同剂量组（＾９０Ｙ－ＧＴＭＳ剂量分组为９２．５、１８５、３７０ＭＢｑ，＾３２Ｐ－ＧＴＭＳ剂量分组为３７、９２．５、１８５ＭＢｑ）的治疗，治疗后不同时间观察疗效，获得核素在单位体积中有效剂量后应用于临床。借助Ｂ超对肿     

不同剂量X射线全身照射对小鼠脾细胞周期进程的影响

采用流式细胞术研究了Ｘ射线全身照射后小鼠脾细胞周期的进程及其剂量效应关系。结果表明,７５ｍＧｙＸ射线全身照射后１２￣７２ｈ脾细胞周期各时相细胞数目发生明显变化,Ｇ０／Ｇ１期细胞数低于假照组,Ｓ组细胞数增多,说明其ＤＮＡ合成能力增强,至７ｄ时回复至假照组水平;２．０Ｇｙ全身照射后８ｈ时脾细胞出现明显的Ｇ２阻滞,１２ｈ时Ｇ２阻滞和ＤＮＡ合成抑制达最高点,７２ｈ其细胞周期进程则明显加快,至７ｄ时回复至假     

17-AAG对HeLa细胞和V79细胞放射敏感性的影响

为研究17-AAG对肿瘤细胞和正常细胞辐射敏感性的影响,以人宫颈癌Hela细胞和中国仓鼠肺成纤维细胞V79为研究对象,用克隆形成实验观察细胞的存活率。结果表明,17-AAG能明显降低受X射线照射的Hela细胞的存活率,而对V79细胞的存活率则无明显影响,表明17-AAG对HeLa细胞具有放射增敏作用,对V79细胞无放射敏感影响。     

利用^32P研究提高新疆主要土壤中磷肥有效利用率的途径

新疆当季作物的磷肥利用率很低，一般只有１０％左右。大量的试验证明应用常规法难以提高。如何进一步提高磷肥的有效利用率，达到增产、高效益的目的是新疆农业生产中亟待研究解决的问题。我们的工作利用了３２Ｐ示踪法，对新疆代表土类灌耕灰漠土、灌耕棕漠土添加硝基腐...     

液闪法提高^32P计数效率的研究

对＾３２Ｐ的切仑科夫计数法及液闪测量作了比较,同时对于不同样品瓶和闪烁液对＾３２Ｐ计数效率的影响进行了实验比较,指出提高＾３２Ｐ测量效率的途径。     

60Co γ射线照射对k562细胞周期变化的影响

以不同剂量的60Co γ射线照射人红白血病细胞系k562细胞,用流式细胞仪检测照射后24小时及不同时间点的细胞周期变化.照后24小时检测结果表明,随着照射剂量的增加,G2/M期细胞比率增加,剂量达15 Gy时,出现明显的G2/M期阻滞;随着剂量的进一步增加,S期细胞比率逐渐增加,剂量达30 Gy时出现明显的S期阻滞;在此剂量(5～30 Gy)下,细胞凋亡未见明显变化.不同时间点的检测结果表明,随着照射剂量的增加,k562细胞从以G2/M期阻滞为主逐渐转化为以S期阻滞为主,同时细胞凋亡也明显增加.     

Smac基因对γ射线照射诱导的宫颈癌HeLa细胞凋亡的影响

将Smac基因全长cDNA转染HeLa细胞,以探讨Smac基因过表达对γ射线诱导的宫颈癌HeLa细胞凋亡的影响及其可能机制.转染24小时后 Western Blot结果表明,转染Smac基因全长cDNA的HeLa/Smac细胞其Smac基因表达量与转染pcDNA3.1空载体的HeLa/pcDNA3.1细胞Smac基因表达量相比上调,而相反Smac基因的底物Survivin基因表达量下调.γ射线照射后HeLa/Smac细胞与HeLa/pcDNA3.1细胞相比凋亡率显著升高,Caspase-3活性上调,但HeLa/Smac细胞与HeLa/pcDNA3.1细胞相比DNA损伤及修复无显著变化,对细胞周期也无明显影响.     

脉冲电磁波对大鼠甲状腺形态及功能的影响

研究脉冲电磁波（Pulsed electromagnetic wave,PEMW）对大鼠甲状腺形态及功能的影响。雄性SD（Sparague—dawley rats,多雷大鼠）大鼠固定于场强为115kVm^-1的脉冲电磁场中进行1．2万次脉冲的全身辐照,分别于辐照后24、48、96、192h采血、分离血清、应用放射免疫分析方法（Radioimmunoassay,RIA）测定大鼠血清中促甲状腺激素（Thyroid-stimulating hormone,TSH）、甲状腺素（Thyroxine,T4）及三碘甲腺原氨酸（Triiodo—thyronine,T3）的含量;同时取甲状腺,制作常规光镜、电镜标本,分别在光学显微镜和透射电子显微镜下观察甲状腺形态的变化。脉冲电磁波辐照后24h,大鼠血清T3、T4、TSH均迅速上升至最高点,其中T4、TSH与假辐照组比较均有显著性差异（p〈0．01）;随后激素含量逐渐降低,并呈波动性变化。光镜下,各辐照组大鼠甲状腺组织结构未见明显改变;在电子显微镜下,脉冲电磁波辐照后12h大鼠甲状腺滤泡上皮细胞即出现超微结构改变,至48h呈逐渐加重趋势,主要表现为内质网明显扩张、大量蛋白分泌物聚集,脂滴出现,核异染色质的边集等;至照后96h损伤减轻,但尚未完全恢复正常。脉冲电磁波辐照可引起大鼠血清中TSH、T3、T4含量变化和甲状腺超微结构的损伤性改变,其超微结构的损伤主要累及粗面内质网。     

Use of perturbation theory in investigating the engineering and physical characteristics of nuclear power plants

Conclusions and recommendations Thus, the use of perturbation theory allows an economical, searchless, computation procedure to be constructed for the problem of parametric identification. The method may be extended to the case of a multidimensional model with nonlinear and nonsteady operators.At high noise levels of the experimental signal, a functional that is more conservative with respect to noise is preferable, in the form , for which perturbation theory is constructed analogously, under the condition P_j=1. Here also, z^e and y^e may be taken in the form of the results of statistical measurements R_zz and R_zy, i.e., the self- and mutual correlations of the noise functions of these signals, respectively.The perturbation formulas in Eqs. (6) and (9) are useful for the engineering diagnostics of NPP elements performed on the basis of an analysis of slow variations over time in the parametersa _i . In this case, identification by the given algorithm must be repeated periodically in the course of NPP running tests or use.Translated from Atomnaya Énergiya, Vol. 48, No. 4, pp. 238–242, April, 1980.     

低剂量辐射激活NK杀伤活性在过继免疫治疗中的研究进展

NK细胞是机体杀伤肿瘤的重要免疫细胞,低剂量辐射（LDR）可以增强NK细胞的增殖能力及生物活性,其机制可能与LDR后内源性谷胱甘肽的诱导作用、增强P38MAPK信号传导途径有关。NK细胞特别是A-NK细胞是过继性细胞免疫治疗良好的细胞来源,具有很好的治疗恶性肿瘤应用前景。     

Optical characteristics of recrystallized tungsten mirrors exposed to low-energy, high flux D plasmas

The surface topography and optical properties of recrystallized tungsten exposed to a low-energy (38 eV/D), high flux (10²² D/m² s) deuterium plasma with an ion fluence of 10²⁶ D/m² at various temperatures was investigated. It was found that the surface morphology weakly depends on the exposure temperature in the range 320-695 K with the exception of the narrow temperature region around 535 K, where large changes to all optical characteristics occurs. After plasma exposure at this temperature, the surface topography of the W sample is characterized by active blistering as has already been indicated in previous publications. The reflectance found in direct measurements at normal incidence drops in the wavelength interval 220-650 nm, whereas the estimations of reflectance using the ellipsometry data demonstrate some increase.     

Radiosensitivity of hepatoma cell lines and human normal liver cell lines exposed in vitro to carbon ions and argon ions at the HIRFL

Human hepatoma (SMMC-7721) and normal liver (L02) cells were irradiated with γ-rays, ¹²C⁶⁺ and ³⁶Ar¹⁸⁺ ion beams at the Heavy Ion Research Facility in Lanzhou (HIRFL). By using the Calyculin-A induced premature chromosome condensation technique, chromatid-type breaks and isochromatid-type breaks were scored separately. Tumor cells irradiated with heavy ions produced a majority of isochromatid break, while chromatid breaks were dominant when cells were exposed to γ-rays. The relative biological effectiveness (RBE) for irradiation-induced chromatid breaks were 3.6 for L02 and 3.5 for SMMC-7721 cell lines at the LET peak of 96 keVμm⁻¹¹²C⁶⁺ ions, and 2.9 for both of the two cell lines of 512 keVμm⁻¹³⁶Ar¹⁸⁺ ions. It suggested that the RBE of isochromatid-type breaks was pretty high when high-LET radiations were induced. Thus we concluded that the high production of isochromatid-type breaks, induced by the densely ionizing track structure, could be regarded as a signature of high-LET radiation exposure.     

Introduction to resonant magnetic perturbation coils of the J-TEXT Tokamak

To investigate the interactions between both the static and rotating resonant magnetic perturbations (RMP) and the tokamak plasma, two sets of coils, namely static RMP (SRMP) and dynamic RMP (DRMP), are constructed on the J-TEXT tokamak. SRMP is reconstructed from TEXT-U and mainly produces static m/n = 1/1, 2/1 and 3/1 resonant perturbation field, where m and n are the poloidal and toroidal mode numbers, respectively. DRMP, newly designed and installed inside the vacuum vessel, can generate pure 2/1 RMP. DRMP is also designed to operate in the AC mode and can produce rotating 2/1 RMP which will be used to study the tearing mode control. Due to the effect of the eddy current in the vacuum vessel wall, the amplitudes of the 2/1 component will be attenuated to about 1/3.6 of the DC value when the operation frequency is larger than 500 Hz. However, DRMP can still provide sufficient large rotating 2/1 perturbation for tearing mode related studies.     

鹿茸多肽对微波辐射后小鼠学习记忆的影响研究

研究鹿茸多肽(pilose antler peptide) 对微波辐射后小鼠学习记忆的影响,并探讨其作用机制。采用2 450 MHz、平均功率密度为10.0 mW/cm²微波照射小鼠90 min/d,连续28 d,建立小鼠微波辐射致学习记忆障碍模型。同时,微波照射后皮下注射鹿茸多肽25、50、100 mg/kg,连续给药28 d,29 d始采用Y迷宫实验检测小鼠的学习记忆能力,34 d Y迷宫实验结束后断头处死小鼠,酶免法检测脑组织中天冬氨酸(Asp)、γ-氨基丁酸(GABA)、谷氨酸(Glu)、S100B的水平,酶免法检测脑组织中Na⁺-K⁺-ATP酶、单胺氧化酶-B(MAO-B)的活性,黄嘌呤氧化酶法检测脑组织中超氧化物歧化酶(SOD)活性,酶免法检测脑组织中的肿瘤坏死因子α(TNF-α)含量,并取脑组织做HE(苏木精-伊红染色法)染色,光镜下观察脑海马齿状回区组织结构的形态学变化。结果表明,与对照组相比,照射组小鼠在Y迷宫实验中错误逃逸次数增加,脑组织中Asp、Glu含量明显降低、GABA含量明显增高,脑组织中MAO-B活性增高而Na⁺-K⁺-ATP 酶、SOD活性降低,脑组织中S100B、TNF-α含量增高;与照射组比较,鹿茸多肽50、100 mg/kg 减少Y迷宫错误逃逸次数;鹿茸多肽25、50、100 mg/kg增加脑组织中Asp及Glu含量,降低MAO-B活性;鹿茸多肽50、100 mg/kg降低脑组织中GABA、S100B、TNF-α含量,增强脑组织中SOD、Na⁺-K⁺-ATP 酶活性(p<0.05或p<0.01)。病理可见照射组海马齿状回(DG)结构部分细胞体积变大,胞浆疏松、淡染,部分细胞核固缩状态;鹿茸多肽100 mg/kg组较照射组有所改善。实验证明鹿茸多肽(50、100 mg/kg,连用28 d)对微波辐射所致小鼠的学习记忆障碍有一定的改善作用,机制可能与鹿茸多肽通过抗炎作用而减弱氧化应激、改善神经递质水平有关。     

Study on the retention behavior of hydrogen isotopes and the change of chemical states of boron film exposed to hydrogen plasma in LHD

The behavior of hydrogen retention and the change of chemical states of boron film exposed to hydrogen plasma in LHD were investigated. The sample was prepared in LHD, and atomic concentrations for the boron film after hydrogen plasma exposure were changed from 75% for boron, 15% for carbon and 8% for oxygen to 53%, 18% and 22%, respectively. BC bond was a major chemical state of the boron film after hydrogen plasma exposure, although abundance of BB bond was the highest before the plasma exposure. Total hydrogen retention measured by TDS was evaluated to be 1.7 × 10²⁰ H m^?2, and the retentions of hydrogen as BHB, BH and BCH bonds were, respectively, 4.8 × 10¹⁹, 7.2 × 10¹⁹ and 5.2 × 10¹⁹ H m^?2. It was concluded that the hydrogen retention could be estimated by taking account not only of chemical states of impurities, but also of hydrogen depth profile.     

Changed structure and improved operation characteristics of metals and alloys exposed to high power ion beams

The effect of high power ions beams (HPIB) on the structure of Al and Cu metals and P6M5 steel (8.5 × 10⁻⁴% C, 5% Mo, 6% W, 4% Cr, 2% V, 72% Fe) is presented. The thickness of the modified layer in Al and Cu was 150 to 180 μm. Defects observed in the bulk of the sample were shown to increase the microhardness and abrasive wear resistance of the samples. These defects are dislocation loops and prisms of vacancy or may be of interstitial type. The current density (or total deposited energy) was found to be the parameter most strongly influencing the target modification. To investigate the near surface layers, we used positron annihilation and Auger spectroscopy. Further, we measured microhardness and abrasive wear resistance.     

AuNPs@MPA-PEG纳米粒子对肿瘤细胞辐射敏感性影响

为研究3-巯基丙酸(MPA)-聚乙二醇(PEG)修饰的金纳米粒子(AuNPs@MPA-PEG)对人宫颈癌Hela细胞辐射敏感性的影响,以柠檬酸钠为稳定剂,硼氢化钠为还原剂,还原氯金酸制备5.4 nm的金纳米粒子(AuNPs),并分别用MPA-PEG、PEG修饰金纳米粒子,制备AuNPs@MPA-PEG、AuNPs@PEG。通过电感耦合等离子体发射光谱仪检测Hela细胞及细胞核对AuNPs、AuNPs@MPA-PEG、AuNPs@PEG的吸收量;克隆形成法测定AuNPs、AuNPs@MPA-PEG、AuNPs@PEG对X射线照射后Hela细胞存活率的影响。结果表明,Hela细胞和细胞核对AuNPs、AuNPs@MPA-PEG、AuNPs@PEG的吸收量具有浓度依赖性。MPA-PEG、PEG修饰减少细胞对金纳米粒子的吸收,但是MPA-PEG对金纳米粒子进行修饰,却增加细胞核对金纳米粒子的吸收。对于160 kVp X射线,AuNPs、AuNPs@MPA-PEG、AuNPs@PEG均对Hela细胞有辐射增敏作用,但增敏效果不明显。MPA-PEG、PEG修饰没有增加金纳米粒子的辐射增敏作用。