Preliminary study for future ESR dating of solid SO2

Paramagnetic properties of irradiated solid SO₂ have been studied for future ESR dating of icy materials on Io, the satellite of Jupiter. Radical species in solid SO₂ formed by irradiation with γ-rays were measured with ESR at various temperatures to obtain the isothermal decay data, which gave their lifetimes at the ambient temperature on Io by the extrapolation in the Arrhenius plot. ESR parameters and speculative models for observed signals are presented.     

二氧化硫污染对运动大鼠心肌收缩功能的影响及AngⅡ、AT1R的调节作用

目的:观察二氧化硫(SO2)吸入对运动大鼠心肌收缩力的影响并分析其可能机制。方法:48只SD大鼠随机分为空白对照组(RG)、单纯运动组(EG)、单纯SO2污染组(SRG)和SO2污染运动组(SEG),每组12只。SRG组和SEG组置于SO2污染环境(10 mg/m3)中1 h/d,共4周;EG组和SEG组进行电动跑轮运动(8 m/min,1 h/d,连续4周)。实验结束后,称量大鼠体重、心脏重量,并利用公式计算心脏重量指数和体重增长率。采用心脏插管技术测定各组大鼠血液动力学参数;采用放射免疫技术测定各组大鼠心肌AngⅡ含量;采用免疫组织化学技术测定各组大鼠心肌AT1R含量。结果:EG组大鼠心脏重量指数、主动脉收缩压(SBP)、脉压差(PP)、左室内压峰值(LVSP)、左室内压最大上升速率(+dp/dtmax)、左室内压最大下降速率(-dp/dtmax)显著高于RG组(P<0.01),舒张压(DBP)、心率(HR)、心肌AT1R蛋白表达水平显著低于RG组(P<0.01,P<0.05);SRG组和SEG组大鼠心脏重量指数、左室末期舒张压(LVEDP)、心肌AngⅡ含量、AT1R蛋白表达显著高于RG组(P<0.05,P<0.01),±dp/dtmax显著低于RG组(P<0.01);SEG组大鼠SBP、PP、LVSP显著低于RG组(P<0.01),HR显著高于RG组(P<0.01);且SEG组大鼠HR、LVEDP、心肌AngⅡ含量、AT1R蛋白表达显著高于SRG组(P<0.01),SBP、PP、LVSP、±dp/dtmax显著低于SRG组(P<0.01)。结论:SO2污染对运动大鼠心脏收缩功能产生显著负性变力性效应,AngⅡ及其受体AT1R蛋白表达水平上调引起RAS系统功能紊乱是导致运动大鼠心肌收缩力降低的原因之一。     

An analytical solution for the SSFP signal in MRI.

Among previous analyses of the steady-state free-precession (SSFP) signal in rapid MRI, one treatment resulted in equations that require the evaluation of infinite binomial series. Here, an analytical solution is derived by a transformation into the power series expansion of the derivative of the inverse sine function, which is essentially a root. The treatment is extended to include higher-order signals. The results demonstrate the identity of the vastly different equations for the SSFP signals reported so far. Applications consist of the derivation of closed expressions for the signal in echo-shifted MRI and a corresponding analysis of TrueFISP sequences.     

Numerical signal treatment for optimized alanine/ESR dosimetry in the therapy-level dose range

Electron spin resonance (ESR) spectra of alanine detectors irradiated to absorbed doses below 5 Gy are affected by a varying non-linear background which mainly influences the lower limit of detection in alanine/ESR dosimetry. A mathematical method based on fast Fourier transform is described capable of filtering simultaneously background and noise in the frequency domain of ESR spectra. It provides clearer alanine/ESR signals down to 50 mGy. Even in non-irradiated but long-term stored alanine detectors an ESR signal could be observed similar to irradiated alanine (pre-signal). A linear ESR signal vs absorbed dose relationship was found above 200 mGy, after correction for background and pre-signal. The number of repeated ESR read-out cycles and hence the time required for a precise and reliable low-dose evaluation have significantly been reduced. The method has been worked out for the therapy-level dosimetry range and tested on a Bruker ESP 300 and for comparison Bruker EMS 104 ESR spectrometer.     

Rhenium-188 and technetium-99m nitridobis(N-ethoxy-N-ethyldithiocarbamate) leucocyte labelling radiopharmaceuticals: [ReN(NOET)2] and [TcN(NOET)2], NOET = Et(EtO)NCS2: Their in vitro localization and chemical behaviour

In this study, we have investigated the preparation of rhenium-188 nitridobis(N-ethoxy-N-ethyldithiocarbamate) [¹⁸⁸ReN(NOET)₂] (NOET = Et(EtO)NCS₂), analogous to the known technetium-99m radiopharmaceutical. The new ¹⁸⁸Re complex was synthesized in good yield with a satisfactory radiochemical purity, using a kit method. The subcellular localization of both radiopharmaceuticals in granulocytes was observed by microautoradiography. The uptake was independent of the radionuclide and predominantly nuclear. Furthermore, HPLC was used to characterize the ^99mTc complex before and after blood cell labelling and revealed that the intact radiopharmaceutical was involved.     

Thin sintered Al2O3 pellets as thermoluminescent dosimeters for the therapeutic dose range

Thermoluminescent properties of sintered alumina pellets were investigated with the aim of using them as radiation dosimeters. Peak temperatures, signal reproducibility, fading, curves of the response to X-radiation, as well as energy and angular dependences were studied. The results show that the pellets can be used in quality control programs in the therapeutic dose range.     

Arterial haemoglobin oxygen saturation is affected by F1O2 at submaximal running velocities in elite athletes

This study was conducted to determine whether arterial desaturation would occur at submaximal workloads in highly trained endurance athletes and whether saturation is affected by the fraction of oxygen in inspired air (F(I)O2). Six highly trained endurance athletes (5 women and 1 man, aged 25+/-4 yr, VO2max 71.3+/-5.0 ml x kg(-1) x min(-1)) ran 4x4 min on a treadmill in normoxia (F(I)O2 0.209), hypoxia (F(I)O2 0.155) and hyperoxia (F(I)O2 0.293) in a randomized order. The running velocities corresponded to 50, 60, 70 and 80% of their normoxic maximal oxygen uptake (VO2max). In hypoxia, the arterial haemoglobin oxygen saturation percentage (SpO2%) was significantly lower than in hyperoxia and normoxia throughout the test, and the difference became more evident with increasing running intensity. In hyperoxia, the SpO2% was significantly higher than in normoxia at 70% running intensity as well as during recovery. The lowest values of SpO2% were 94.0+/-3.8% (P<0.05, compared with rest) in hyperoxia, 91.0+/-3.6% (P<0.001) in normoxia and 72.8+/-10.2% (P<0.001) in hypoxia. Although the SpO2% varied with the F(I)O2, the VO2 was very similar between the trials, but the blood lactate concentration was elevated in hypoxia and decreased in hyperoxia at the 70% and 80% workloads. In conclusion, elite endurance athletes may show an F(I)O2-dependent limitation for arterial O2 saturation even at submaximal running intensities. In hyperoxia and normoxia, the desaturation is partly transient, but in hypoxia the desaturation worsens parallel with the increase in exercise intensity.     

Comparative evaluations of norepinephrine transporter radioligands with reference tissue models in rhesus monkeys: (S,S)-[18F]FMeNER-D2 and (S,S)-[11C]MeNER

Purpose  

Although two norepinephrine transporter (NET) radioligands, (S,S)-[¹⁸F]FMeNER-D₂ and (S,S)-[¹¹C]MeNER, have been reported to have different characteristics, there has not been a direct comparative study in vivo.     

On the use of Ra as yield tracer and Ba(Ra)SO4 microprecipitation in Ra determination by α-spectrometry

A simple procedure for the determination of ²²⁶Ra in geological samples using α-spectrometry is presented. The method uses ²²⁵Ra as yield tracer, and microprecipitation of Ba(Ra)SO₄ for source preparation. Extensive studies were performed in order to determine the chemical yield of the proposed procedure with precision. The method was tested on a geological reference sample, and gave satisfactory results and high reproducibility.     

Synthesis of [1-C], [2-C], [1-C](H3) and [2-C](H3)acetate for in vivo studies of myocardium using PET

Four isotopically-labelled acetates ([1-¹¹C], [2-¹¹C], [1-¹¹C](²H₃) and [2-¹¹C](²H₃)acetate) were synthesized and used in positron emission tomography (PET) studies of pig myocardium. The [1-¹¹C]acetates were synthesized by carboxylation of the appropriate ¹H or ²H methyl Grignard reagents immobilized on a C₂ solid phase extraction column (SPE). Purification by reverse-phase HPLC, resulted in 35–45% decay-corrected radiochemical yield with a total synthesis time of 25 min, and a radiochemical purity higher than 99%. The [2-¹¹C]acetates were synthesized by carboxylation of ¹¹C-labelled ¹H or ²H methyl lithium. Purification as above resulted in 35–55% decay-corrected radiochemical yield with a total synthesis time of 30 min, and a radiochemical purity higher than 99%. Position-specific labelling was assessed by ¹³C-labelling and NMR.

Multiple isotopic labelling by the combination of position-specific ¹¹C-labelling and ²H substitution, has the potential to highlight different aspects of a complex biochemical system using a selected set of tracers in comparative PET studies. An illustration of this principle is given using acetate, where citric acid cycle metabolism results in a position-specific kinetic for the ¹¹C-label, and deuteration opens up the possibility for the proton-abstracting processes within the citric acid cycle to be assessed.     

Determination of k0-values for the reactions Zr (n, γ) Zr and Zr (n, γ) Zr–Nb by irradiation in highly thermalized neutron flux

Determination of k₀-factors for zirconium isotopes was performed by co-irradiation of Zr and Au–Al. Due to the highly thermalized irradiation position at FRM-II, interferences from epithermal neutrons were found largely decreased for ⁹⁶Zr (n, γ) ⁹⁷Zr–^97mNb, the reaction with the highest Q₀-value in all (n, γ) reactions. Results showed that, the ⁹⁵Zr k₀-values from this work were the same as the recommended ones. For ⁹⁷Zr–^97mNb 743.4 keV gamma-line, the new k₀-value was 2.8% higher compared to the recommended value, which is not a significant difference. These results are helpful in clarifying the suspicion about the Zr k₀-factors.     

89SrCl2在治疗乳腺癌骨转移中的临床疗效

目的 评价⁸⁹SrCl₂治疗乳腺癌骨转移的临床疗效,及其血液学毒副作用。方法 51例患者接受⁸⁹SrCl₂治疗,静脉注射剂量为2.22 MBq/kg体重,观察治疗前后止痛效果,病灶变化和外周血细胞变化。结果 患者疼痛完全缓解率为37.7%(17/45),总缓解率为84.4%。病灶治疗有效率为62.7%(32/51)。治疗后1个月白细胞和血小板减少者分别为76.5%和62.7%。3个月后大多数患者经治疗血象恢复到正常。结论 ⁸⁹SrCl₂可安全、有效地治疗乳腺癌骨转移患者的疼痛,并对其生活质量有所改善。     

经皮穿刺L5—S1椎间盘髓核摘除术前入路的应用解剖

目的为经皮穿刺L5-S1椎间盘髓核摘除术前入路提供解剖学基础.方法在32具成人尸体标本上解剖观察L5-S1椎间盘前方的毗邻关系.结果L5-S1椎间盘前方存在一个由左、右髂血管和骶岬上缘平面围成的"△"相对安全区,该区的面积是11.59±3.34(7.40～17.42)cm2,在该区内没有大的血管和神经干.结论用穿刺导管从腹前壁经腹膜直抵椎间盘前面,椎间盘前方的小肠被"T"型杵状压腹器自动推开,从而可经双侧髂血管之间由前面较安全地穿入椎间盘中点.     

Cross sections for (n, 2n), (n, p) and (n, α) reactions on rare-earth isotopes at 14.7 MeV

Cross sections for (n, 2n)·(n,p) and (n, α) reactions have been measured on some rare-earth isotopes at 14.7±0.2 MeV using the activation technique. Data are reported for the following reactions: ¹⁵⁴Sm(n,2n) ¹⁵³Sm, ¹⁶²Er(n, 2n) ¹⁶¹Er, ¹⁶⁸Yb(n, 2n) ¹⁶⁷Yb, ¹⁷⁴Hf(n, 2n) ¹⁷³Hf, ¹⁷⁶Hf(n, 2n) ¹⁷⁵Hf, ¹⁴²Ce(n, p) ¹⁴²La, ¹⁴⁴Sm(n, p) ¹⁴⁴Pm, ¹⁴⁸Sm(n, p) ^148mPm, ¹⁴⁸Sm(n, p) ^148gPm, ¹⁵⁰Sm(n, p) ¹⁵⁰Pm, ¹⁶⁰Dy(n, p) ¹⁶⁰Tb, ¹⁶²Dy(n, p) ¹⁶²Tb, ¹⁶³Dy(n, p) ¹⁶³Tb, ¹⁶⁶Er(n, p) ^166gHo, ¹⁶⁷Er(n, p) ¹⁶⁷Ho, ¹⁶⁸Er(n, p) ¹⁶⁸Ho, ¹⁷⁴Yb(n, p) ¹⁷⁴Tm, ¹⁵⁰Sm(n, α) ¹⁴⁷Nd, ¹⁵²Sm(n, α) ¹⁴⁹Nd, ¹⁵⁴Sm(n, α) ¹⁵¹Nd, ¹⁵³Eu(n, α) ¹⁵⁰Pm, ¹⁵⁹Tb(n, α) ¹⁵⁶Eu, ¹⁶²Dy(n, α) ¹⁵⁹Gd, ¹⁶⁴Dy(n, α) ¹⁶¹Gd, ¹⁶⁸Er(n, α) ¹⁶⁵Dy, ¹⁶⁹Tm(n, α) ^166gHo, ¹⁷⁸Hf(n, α) ¹⁷⁵Yb, ¹⁸⁰Hf(n, α) ¹⁷⁷Yb.     

99Tcm-3PRGD2 SPECT/CT分子影像在乳腺癌诊疗中的应用进展

乳腺癌是女性发病率最高的恶性肿瘤。99Tcm-联胼尼克酰胺-3聚乙二醇-精氨酸-甘氨酸-天冬氨酸环肽二聚体（99Tcm-3PRGD₂）是近年来人工合成的可用于乳腺癌分子显像的一种SPECT示踪剂。99Tcm-3PRGD₂ SPECT/CT可用于早期诊断乳腺癌并进行准确的分期及分子分型,据此进行诊疗方案的选择,有助于降低患者的病死率,并提高患者的生活质量。笔者就99Tcm-3PRGD₂ SPECT/CT在乳腺癌诊疗过程中的应用进展进行综述,并作出展望。     

Thiol-PEG-carboxyl-stabilized Fe2O3/Au nanoparticles targeted to CD105: Synthesis,characterization and application in MR imaging of tumor angiogenesis

Objective

To detect tumor angiogenesis in tumor-bearing mice using thiol-PEG-carboxyl-stabilized Fe₂O₃/Au nanoparticles targeted to CD105 on magnetic resonance imaging (MRI).

Methods

Fe₂O₃/Au nanoparticles (hybrids) were prepared by reducing Au³⁺ on the surface of Fe₂O₃ nanoparticles. Hybrids were stabilized with thiol-PEG-carboxyl via the Au–S covalent bond, and further conjugated with anti-CD105 antibodies through amide linkages. Characteristics of the hybrid-PEG-CD105 nanoparticles were evaluated. Using these nanoparticles, the labeling specificity of human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. MRI T2*-weighted images were obtained at different time points after intravenous administration of the hybrid-PEG-CD105 nanoparticles in the tumor-bearing mice. After MR imaging, the breast cancer xenografts were immediately resected for immunohistochemistry staining and Prussian blue staining to measure the tumor microvessel density (MVD) and evaluate the labeling of blood microvessels by the hybrid-PEG-CD105 nanoparticles in vivo.

Results

The mean diameter of the hybrid-PEG-CD105 nanoparticles was 56.6 ± 8.0 nm, as measured by transmission electron microscopy (TEM). Immune activity of the hybrid-PEG-CD105 nanoparticles was 53% of that of the anti-CD105 antibody, as detected by enzyme-linked immunosorbent assay (ELISA). The specific binding of HUVECs with the hybrid-PEG-CD105 nanoparticles was proved by immunostaining and Prussian blue staining in vitro. For breast cancer xenografts, the combination of the hybrid-PEG-CD105 nanoparticles with blood microvessels was detectable by MRI after 60 min administration of the contrast agent. The T2* relative signal intensity (SI_R) was positively correlated with the tumor MVD (R² = 0.8972).

Conclusion

Anti-CD105 antibody-coupled, thiol-PEG-carboxyl-stabilized core–shell Fe₂O₃/Au nanoparticles can efficiently target CD105 expressed by HUVECs. Furthermore, the hybrid-PEG-CD105 nanoparticles can be used to detect tumor angiogenesis in vivo.     

鼻咽肿瘤活检组织SF2对放射效应的预测价值探讨

目的　探讨用组织块培养图像分析技术测定鼻咽肿瘤组织SF2 值对肿瘤放射效应的预测价值。方法　用组织块培养图像分析技术测定 4 6例鼻咽癌患者新鲜的鼻咽部活检病理标本的SF2 ,并用CT和临床体检手段评估患者放疗过程中的鼻咽部肿瘤消退情况和颈部转移淋巴结消退情况 ,以放疗结束后 3月时CT和临床资料评估即时疗效。结果　 4 6例活检肿瘤组织的SF2 与鼻咽部肿瘤完全消退剂量、转移淋巴结全消退剂量、4 0Gy时鼻咽部肿瘤消退比和 4 0Gy时淋巴结消退比之间有明显的相关性 ,r值分别为 0 881(P <0 0 1)、0 75 1(P <0 0 1)、- 0 733(P <0 0 1)、- 0 6 0 9(P <0 0 1)。按SF2 的中位数值分组 ,SF2 高组和低组之间的上述观察指标之间差异均有非常显著性 (P<0 0 1) ;同时SF2 值低组患者的即时疗效明显优于SF2 高组。结论　鼻咽肿瘤组织的SF2 值在一定程度上可以反映患者肿瘤的放射效应 ,其值越小肿瘤消退越快 ,肿瘤放疗的近期局控率越高     

非小细胞肺癌:FDG-PET显像纵隔浓集灶对N0-N1期病灶预后的重要意义

目的评价非小细胞肺癌(NSCLC)行根治性切除,纵隔淋巴结(LN)组织学检查阴性,但PET显示FDG异常浓集(阳性)时对病人预后的意义。我们假设即便LN组织学检查阴性,PET上的阳性灶仍对预后有价值。材料与方法本研究通过专业审查委员会批准,遵从HIPAA。收集2000