EARLY DIAGNOSIS OF TUMOR WITH ELECTRON SPIN RESONANCE (ESR): METHOD OF ELECTRONIC SATURATION OF ENERGY LEVEL

ESR saturation power point of the hair of healthy, lung cancer, esophageal cancer, as well as silicosis, tuberculosis and cardiovascular disease were detected. The results show that the positive rate is 1.69%, 85.42%, 90.4%, 20.00%, 27.27% and 0% respectively. There is a significant difference between lung cancer, esophageal cancer and healthy persons (P<0. 001). ESR saturation power point elevates sharply after treatment of lung cancer, 71. 43% of total cases ranged from 7. 9 to 24. 0 (mW), after treatment of esophageal cancer, 71. 23% ranged from 7.9 to 19.9 (mW). All patients with cardiovascular disease were examined to be negative, i. e. , above 10. 0 (mW).

Electron spin resonance study of the Ba-doping manganite Nd_(0.5)Sr_(0.5)MnO_3

We have performed magnetization measurements and electron spin resonance （ESR） on polycrystalline manganites of Nd0.5Sr0.5-xBaxMnO3 （x = 0.1）. Phase separation and phase transitions are observed from the susceptibility and the ESR spectra data. Between 260 K （～ Tc） and 185 K （～ TN）, the system coexists of the paramagnetic phase and the ferromagnetic （FM） phase. Between 185 K and 140 K, the system coexists of the FM phase and the antiferromagnetic （AFM） phase. These results indicate that the system has a very complex magnetic state due to the origin of the instability stemming from manganite Nd0.5Sr0.4Ba0.1MnO3 by partially substituting the larger Ba^2＋ ions for the smaller Sr^2＋ ions.

Associations of oxidative stress and inflammation and their role in the regulation of membrane fluidity of red blood cells in hypertensive and normotensive men: An electron spin resonance investigation

There is evidence showing that increased levels of oxidative stress and C-reactive protein (CRP) might be associated with obesity, hypertension, atherosclerosis and other cardiovascular diseases. This study was undertaken to investigate possible relationships among plasma 8-iso-prostaglandin F2α (8-iso-PG F2α: an index of oxidative stress), high-sensitivity (hs)-CRP and membrane fluidity (a reciprocal value of microviscosity) in hypertensive and normotensive men using an electron spin resonance (ESR)-method. The order parameter (S) for the spin-label agents (5-nitroxide stearate) of red blood cell (RBC) membranes in the ESR spectra was significantly higher in hypertensive men than in normotensive men, indicating that membrane fluidity was decreased in hypertensive men. Both plasma 8-iso-PG F2α and hs-CRP levels were significantly increased in hypertensive men compared with normotensive men. In addition, plasma plasma 8-iso-PG F2α levels were correlated with plasma hs-CRP levels. In contrast, plasma nitric oxide (NO)-metabolites were lower in hypertensive men than in normotensive men, and inversely correlated with plasma 8-iso-PG F2α and hs-CRP. The order parameter(S) of RBCs was correlated with plasma 8-iso-PG F2α and plasma hs-CRP, and inversely correlated with plasma NO-metabolites, suggesting that reduced membrane fluidity of RBCs might be associated with increased oxidative stress, inflammation and endothelial dysfunction. Multivariate regression analysis also showed that, after adjusting for general risk factors, both plasma 8-iso-PG F2α and hs-CRP were significant determinants of membrane fluidity of RBCs. The ESR suggests that associations of oxidative stress and inflammation might have a close correlation with impaired rheologic behavior of RBCs and microcirculatory dysfunction in hypertensive men.

Novel Magnetic Properties of Single-Crystalline Bi_2Fe_4O_9 Nanosheets by Electron Spin Resonance

Magnetic properties of single-crystalline preferential {001}-oriented Bi2Fe4O9nanosheets with thickness of about 13 nm, synthesized via a facile hydrothermal method, have been investigated through variable temperature electron spin resonance measurement. A typical ferromagnetic state could be appeared in the measured temperature from 110 K to 300 K and the origin would be contributed to uncompensated surface spin due to its large surface-to-volume ratio and/or a few non-detectable impurities with strong magnetism. Interestingly, another weak ferromagnetic state could present below the temperature about 250 K, indicative of Neel temperature (TN) of antiferromagnetic state, which is slightly lower than that of bulksample of 265 K.

An electron spin resonance study of Eu doping effect in La_(4/3)Sr_(5/3)Mn_2O_7 single crystal

The effect of Eu3＋ ion doping in the La sites of single-crystal La4/3Srs/3Mn2O7 was investigated. Electron spin resonance （ESR） was applied to La4/3Sr5/3Mn2O7 and （Lao.8Euo.2）4/3Sr5/3Mn2O7 single crystals. A phase separation and phase transitions were observed from the ESR spectra data. Between 350 K and 300 K, both paramagnetic resonance （PMR） and anisotropic ferromagnetic resonance （FMR） lines were observed in the ab plane and the c axis direction, suggesting a coexistence of the paramagnetic （PM） phase and the ferromagnetic （FM） phase. The magnetization measurement reveals a spin-glass-like behavior in single-crystal （Lao.8Euo.2）4/3 Sr5/3Mn2O7 below the temperature of spin freezing Tf （- 29.5 K）.

Electron spin resonance investigation of the substitution of Fe^(3+) for Ti^(4+) ions in rutile TiO_2 single crystal

A Fe doped rutile TiO2 single crystal is grown in an O2 atmosphere by the floating zone technique. Electron spin resonance （ESR） spectra clearly demonstrate that Fe^3＋ ions are substituted for the Ti^4＋ ions in the rutile TiO2 matrix. Magnetization measurements reveal that the Fe：TiO2 crystal shows paramagnetic behaviour in a temperature range from 5 K to 350 K. The Fe^3＋ ions possess weak magnetic anisotropy with an easy axis along the c axis. The annealed Fe：TiO2 crystal shows spin-glass-like behaviours due to the aggregation of the ferromagnetic clusters.

Hyperhomocysteinemia and Increased Oxidative Stress Levels Are Associated with Impaired Membrane Fluidity of Red Blood Cells in Hypertensive and Normotensive Men: An Electron Spin Resonance Investigation

Hyperhomocysteinemia and oxidative stress may be strongly linked to hypertension, atherosclerosis and other cardiovascular diseases. The present study was performed to investigate possible relationships among plasma total homocysteine, plasma 8-iso-prostaglandin F2α (8-isoPG F2α: an index of oxidative stress), and membrane fluidity (a reciprocal value of membrane microviscosity) in hypertension. We measured the membrane fluidity of red blood cells (RBCs) in hypertensive and normotensive men using an electron spin resonance (ESR) and spin-labeling method. Membrane fluidity of RBCs was significantly decreased in hypertensive men compared with normotensive men. Plasma total homocysteine levels were significantly higher in hypertensive men than in normotensive men, and correlated with plasma 8-isoPG F2α. In contrast, plasma nitric oxide (NO)-metabolites (an index of endothelial function) were lower in hypertensive men than in normotensive men. The reduced membrane fluidity of RBCs was associated with increased total homocysteine and plasma 8-isoPG F2α levels and decreased plasma NO-metabolite levels. Multivariate regression analysis showed that, after adjusting for general risk factors, plasma total homocysteine and 8-isoPG F2α were significant determinants of membrane fluidity of RBCs, respectively. These results suggest that hyperhomocysteinemia and oxidative stress with endothelial dysfunction might have a close correlation with impaired rheologic behavior of RBCs and circulatory disorders in hypertensive men.

Monitoring the autoproteolysis of hiv-1 protease by site-directed spin-labeling and electron paramagnetic resonance spectroscopy

Site-directed spin-labeling with continuous wave electron paramagnetic resonance spectroscopy was used to monitor autoproteolysis of HIV-1 protease, an enzyme essential for viral maturation. Two protein constructs were examined, namely subtype F and the circulating recombinant form CRF01_A/E. As the protease undergoes self-cleavage, protein unfolds and small peptide fragments containing the spin label are generated, which collectively give rise to a sharp spectral component that is easily discernable in the high-field resonance line in the EPR spectrum. By monitoring the intensity of this spectral component over time, the autoproteolytic stability of each construct was characterized under various conditions. Data were collected for samples stored at 4 °C, 25 °C, and 37 °C, and on a subtype F HIV-1 protease sample stored at 25 °C and containing the FDA-approved protease inhibitor Tipranavir. As expected, the rate of autoproteolysis decreased as the storage temperature was lowered. Minimal autoproteolysis was seen for the sample that contained Tipranavir, providing direction for future spectroscopic studies of active protease samples. When compared to standard methods of monitoring protein degradation such as gel electrophoresis or chromatographic analyses, spin-labeling with CW EPR offers a facile, real-time, non-consuming way to monitor autoproteolysis or protein degradation. Additionally, mass spectrometry studies revealed that the N-termini of both constructs are sensitive to degradation and that the sites of specific autoproteolysis vary.

Application of Theories of Free Radicals and Electron Spin Resonance for Research of Traditional Chinese Medicine

The present paper reviews new findings in redoxproperties of the active constituent of Chinese herbalmedicine(CHM),a kind of CHM or a compoundprescription as an antioxidant.Firstly,we have studiedtheir antioxidant and prooxidant actions with electronspin resonance(ESR).The results show that the activecomponents from over 10 kinds of CHM are able toscavenge the oxygen free radicals but propyl gallate

云南省洱源县新构造运动的ESR年代学证据

云南省洱源县具有复杂的构造特征和强烈的新构造运动,为详细分析该地区新构造运动的基本特征,本次研究进行了野外岩石样品的电子自旋共振(ESR)年龄测定工作,结果表明:样品年龄数据介于62~1007ka之间,属于新构造运动时期;ESR年龄值由西向东具有逐渐减小的趋势,表明更新世以来,洱源县构造运动关键期由西向东逐渐变晚;结合样品所在海拔和ESR年龄,认为现今海拔高的区域,相对构造隆升时间早、持续时间长,具有较大隆升速率;现今海拔较低的盆山接触带新构造运动表现较为强烈,具有较小ESR年龄值、碎屑岩中的多条小型(伴生)断裂,且天然地震多发。

Election Spin Resonance Studies of Free Radical Formation and Oxygen Consumption of Lens Epithelium During Ultraviolet Exposure

A long life election spin resonance (ESR) signal at g=2.0006 was observed in the normal lens epithelium and cortical fibers. During ultraviolet (UV) exposure, a new ESR signal at g = 2.0060 was found in the lens epithelium. But this specific signal was not detected in the lens cortical fibers. This suggested that lens epithelial cells were more susceptible to the free radical formation which was induced by UV light. By means of ESR spin probe oxymetry, the oxygen uptake of lens epithelial cells was meas...

一般条件下的电子自旋共振(ESR)理论

文中从数学的角度分析了dμz/dt=0在电子自旋共振(ESR)中的物理含义,把ESR理论由直流磁场推广到了交流磁场,而直流磁场下的ESR理论只是当交流磁场的频率为0时的一种特殊情况,从而建立了一般条件下的ESR理论和一般条件下实现ESR的方法。该理论的建立使得采用ESR原理研制的分析仪器省去了耗能大、重量重、造价高的直流磁场,仅采用原有的调制磁场便可实现ESR,从而大大降低了该分析仪器的体积、重量、耗能和成本,具有一定的理论研究和推广应用价值。

Evaluation of Hydroxyl Radical and Alkyl-oxy Radical Scavenging Activity of Coffee by ESR Spin Trapping Method

We evaluated the hydroxyl and alkyl-oxy radical scavenging activity of instant coffee using an electron spin resonance （ESR） spin-trapping method, which was based the spin-trapping reagent 5-（2,2-dimethy-l,3-propoxycyclophosphoryl）-5-methyl-l-pyrroline N-oxide （CYPMPO）. In this method, very pure hydroxyl and alkyl-oxy radicals were generated by illuminating a phosphate buffer solution containing hydrogen peroxide and 2,2＇-azobis （2-amidinopropane） dihydrochloride with a Hg-Xe arc lamp. The ESR adduct signal was sensitive and very stable. We concluded that instant coffee has high hydroxyl radical and alkyl-oxy radical scavenging activity.

Theory of phonon-modulated electron spin relaxation time based on the projection reduction method

This paper introduces a new method for a formula for electron spin relaxation time of a system of electrons interacting with phonons through phonon-modulated spin-orbit coupling using the projection-reduction method. The phonon absorption and emission processes as well as the photon absorption and emission processes in all electron transition processes can be explained in an organized manner, and the result can be represented in a diagram that can provide intuition for the quantum dynamics of electrons in a solid. The temperature （T） dependence of electron spin relaxation times （T1） in silicon is T1 ∝ T-1.07 at low temperatures and T1 ∝ T-3.3 at high temperatures for acoustic deformation constant Pad = 1.4 × 10^7 eV and optical deformation constant Pod = 4.0 × 10^17 eV/m. This means that electrons are scattered by the acoustic deformation phonons at low temperatures and optical deformation phonons at high temperatures, respectively. The magnetic field （B） dependence of the relaxation times is T1 ∝ B-2.7 at 100 K and T1 ∝ B-2.3 at 150 K, which nearly agree with the result of Yafet, T1 ∝ B-3.0- B -2.5.

Co and Phthalocyanine Overlayers on the Quantum-Well System Co(001)/Cu: Spin-Polarized Electron Reflection Experiments

The influence of a Co or phthalocyanine (Pc) molecular overlayer on the properties of quantum-well resonances (QWR) in Cu layers atop Co(001) is studied by means of spin-polarized electron reflection. For Co atoms and Pc molecules, an energy shift of the QWR-induced signal is observed with increasing coverage and is attributed to a variation of the electron reflection phase at the Cu/Co and Cu/Pc interface. For Co we find a linear energy shift in the Cu QWR energy position with increasing coverage down to the sub-monolayer regime. This shows that the phase accumulation model remains accurate within the sub-monolayer regime of a discontinuous interface. An opposite sign in the energy shift between Co and Pc overlayers could reflect an opposite impact on the Cu surface work function of overlayer adsorption.

ESR定年:一种确定脆性断层活动年龄的方法原理与应用

在浅层低温环境中，脆性断层活动难以生成新的变质矿物，断层的准确活动年龄就难以确定。但在浅层断层活动中，往往伴生有同期生成的石英脉，对石英脉采用热活化电子自旋共振（ESR）测年，能够确定石英脉的生成年龄，从而能提供断层活动的年龄。如果断层带中发育有多期石英脉，通过测定还能提供断层多次活动的年龄。以雪峰山2条断裂带为例，使用ESR定年方法获得了202．3～60．6Ma的地质年龄，并探讨了2条断裂带的演化与区域构造活动的关系，最后对ESR测年的可信性与使用条件进行了讨论。

河北沧州小山火山的ESR年代学研究

河北沧州小山火山是河北平原,包括华北平原少有的出露地表的第四纪火山,也可能是华北平原区最后一个活动的火山。因此,此火山极其重要,可是至今没有确切的年代学数据。本次研究分别从小山火山地表和钻孔中采集了7个样品,进行了电子自旋共振测年。每个样品都分选出了石英颗粒,这表明火山堆积物不是纯的凝灰岩,而是火山活动时,同时带有地表物质的混入。样品ESR测年结果在误差范围内一致,平均值为41.4±8.6ka。小山火山活动可能发生于41ka BP.,测年结果表明小山火山最后一次活动在晚更新世晚期。

褐藻硫酸多糖清除活性氧自由基作用及动力学的ESR研究

利用ＥＳＲ和自旋捕集技术，首次观察了不同方法提取的两种褐藻硫酸多糖（ＳＰ）对Ｆｅｎｔｏｎ反应和光照Ｈ２Ｏ２两个体系产生的·ＯＨ清除作用，及对次黄嘌呤／黄嘌呤氧化酶和光照核黄素两个体系产生的Ｏ－．２（ＨＯ·２）清除作用，并且对其清除·ＯＨ和Ｏ－．２的动力学进行了研究。结果表明，热提取物（ＳＰｈ）和冷提取物（ＳＰｃ）均有明显清除ＯＨ和Ｏ－．２作用，且呈量效关系。对Ｏ－．２的清除率高于对·ＯＨ的清除率（８４．７％ｖｓ６９．２％）。ＳＰｈ对两种自由基的清除效果比ＳＰｃ好。在光照核黄素体系中ＳＰｈ３０ｇ／Ｌ几乎完全清除Ｏ－．２，ＳＰｃ可清除６８．９％，而在次黄嘌呤／黄嘌呤氧化酶体系中只需３ｇ／ＬＳＰｈ便可完全清除Ｏ－．２。１５ｇ／ＬＳＰｈ和３０ｇ／ＬＳＰｃ对Ｆｅｎｔｏｎ反应产生的·ＯＨ的清除率分别为７７．７％和６８．７％。动力学研究表明，ＳＰｈ与·ＯＨ和Ｏ－．２反应的表观速率常数分别为７．１×１０９ｍｏｌ－１·ｓ－１和３２３０．５ｍｏｌ－１·ｓ－１。实验提示ＳＰ可作为一种预防性的抗氧化剂。确证ＳＰ清除自由基为研究其抗ＨＩＶ及肿瘤的机理提供了一条新途径。