Thermoluminescence and electron spin resonance properties of some travertines from Turkey

For the sake of dating certain calcite geological samples, the TL and ESR properties of travertines from Denizli (in the southwestern part of Turkey) were studied and the effects of pre-heating temperature and pre-heating time on the sensitivity of the samples to radiation evaluated. Heat treatment above 350°C increases the sensitivity of all radiation-induced TL peaks except the 330°C glow peak. Results of gamma-ray dose calibration in travertine (CaCO₃ crystal of trigonal symmetry) indicate that the 180 and 280°C TL peak amplitudes increase exponentially with dose. We show that second-order kinetics characterizes the 180 and 280°C glow peaks reasonably well. The Mn²⁺ lines of the ESR spectra are used to investigate the thermal decomposition processes of travertine samples, showing very good agreement with those of thermogravimetry. Glow mechanisms of TL in travertine have also been studied using ESR analysis. The pre-heating and subsequent laboratory irradiation procedure is found to enhance the TL and ESR signals of CO₃³⁻ and CO₂⁻ centres. An isochronal thermal anneal sequence experiment showed that 180 and 280°C peaks in travertines are correlated with CO₃³⁻ and CO₂⁻ centres in the same way that the peak at 330°C is correlated with SO₂⁻ centres. A model for the recombination mechanism is suggested on the basis of the TL and ESR measurements.     

玻璃电子自旋共振剂量学特性的研究进展

辐照后的玻璃可经电子自旋共振（ESR）波谱仪检测出ESR信号,包括本底信号、机械信号和辐射信号。ESR信号的大小与受照剂量基本成正比。当发生核事故或突发辐射意外时,可以通过对受照人员随身携带物品或事故区域内的玻璃进行ESR测量,快速估算事故剂量,评价事故的严重程度,并对受照人员进行及时的医学救治。玻璃具有廉价、化学惰性、刚度好、易于处理、普遍易得等特点,是一种很有前景的剂量估算物理剂量计。笔者主要对玻璃构成、剂量估算原理、ESR信号组成及其剂量学特性进行了探讨。     

Electron spin resonance imaging of tissues with lipid-rich areas

Electron spin resonance imaging and spectroscopy of lipid-rich samples were studied at 9 Ghz. Using both lipid- and aqueous-soluble nitroxides good delineation of fat- and muscle-rich regions of tissue was obtained. Several different principles can be used to differentiate between these types of tissues and potentially between different types of lipids. These principles include lipophilicity of nitroxides, viscosity (which is higher in lipids), oxygen solubility (oxygen is four times more soluble in lipids), and the distribution of paramagnetic metal ions. These techniques have potential applicability for directly studying metabolism and oxygen concentration in tissues by ESR techniques and for investigating potential contrast agents for in vivo NMR techniques.     

Electron spin resonance as a useful technique in the management of Hodgkin's disease.

Electron spin resonance spectroscopy has proved a useful and simple technique for the measurement of levels of caeruloplasmin and iron transferrin in whole blood from 50 patients with Hodgkin's disease. Those patients with clinically active disease show higher caeruloplasmin levels and lower iron transferrin levels than those with inactive disease. The results indicate that these tests are good indicators of the state of the disease and that serial measurement of these parameters may help in early prediction of clinical reactivity and in monitoring response to treatment. The combined information from iron transferrin and caeruloplasmin levels appears to be more predictive than that from the erythrocyte sedimentation rate and neutrophil alkaline phosphatase score.     

Electron spin resonance of particulate soot samples from automobiles to help environmental studies.

The application of electron spin resonance (ESR) was studied for diesel soot samples and suspended particulate matter (SPM) from automobile engines. Soot samples or diesel exhaust particles (DEP) were recovered at various points: in the exhaust pipe of a diesel engine, at the dust sampler of a highway tunnel (standard DEP), on the soundproofing wall alongside a heavy traffic road, and on the filters of a dust sampler for SPM. The diesel soot samples apparently showed two ESR spectra: one was a broad spectrum at g=2.1 with a line width of ca. 80-120 mT and the other was a sharp signal of a carbon radical at g=2.003 with a line width of 0.4 mT. Annealing experiments with a DEP sample at 250 degrees C revealed drastic enhancement of the sharp ESR signal, which suggested a thermal process of carbonization of remnant organics. An oximetric study by ESR showed an enhancement of the broad signal in the diesel soot sample as well as in the sharp ESR signal. Therefore, the main part of the broad ESR signal would be attributed to carbon radicals, which form a different configuration, probably closely interacting aggregates. Enhancement of the sharp ESR signal was not observed in the standard DEP sample under vacuum condition, which suggested less adsorption sites on the surface of DEP samples.     

Luminescence dating of a geological sample from Denizli, Turkey.

Recent advances in luminescence dating have led to increasing application of the optically stimulated luminescence (OSL) technique to investigate the sedimentation of the depositional environmental samples. In this study, a geological sample was dated by using OSL technique. The sample was collected from a main fault line located in Denizli, Turkey. It was prepared using the fine grain method. The optimum preheat temperature of 205 degrees C and duration value of 3 min are determined through a sequence of experiments. For the calculation of the age of the samples the equivalent dose (ED) was measured using both the multiple-aliquot and single-aliquot techniques. The annual dose (AD) was obtained by measuring the concentration of the major radioactive isotopes in the samples by using a high purity Ge detector. The age of the sample was found to be between 5490 +/- 300 years and 6000 +/- 320 years.     

Electron spin resonance dosimetry of teeth of Goiania radiation accident victims.

Electron spin resonance (ESR) spectroscopy is used to assess absorbed doses of six teeth belonging to victims of the highly irradiated group of Goiania accident. The influence of the broad background signal at g = 2.0040 as well as of the unstable fraction of CO2- radicals was taken into account in dose estimates. Three victims teeth showed absorbed doses comparable to those estimated by chromosomal analysis. For the other three teeth, the doses were higher by a factor of 1.3, 1.8 and 2.2.     

Electron spin resonance (ESR), electron nuclear double resonance (ENDOR) and general triple resonance of irradiated biocarbonates

Several irradiated biocarbonates were studied by magnetic resonance techniques. Seven paramagnetic species, attributed to CO₂⁻, SO₂⁻ and SO₃⁻ were identified. Comparison between radiation induced defects in bioaragonites and aragonite single-crystals shows that isotropic and orhorhombic CO₂⁻ centers with broad line spectra are not produced in the latter samples. Vibrational and rotational properties of isotropic CO₂⁻ centers were studied from low temperature Q-band spectra. Vibrational frequency is determined from the ¹³CO₂⁻ hyperfine spectrum and yielded v=1.54 × 10¹³ s⁻¹. The correlation time for isotropic CO₂⁻, τ_c=1.2 × 10⁻¹¹s (T=300 K), is typical of radicals rotating in liquids. ENDOR and General Triple spectroscopy show that orthorhombic CO₂⁻ centers are surrounded by water molecules located in the second nearest CO₃²⁻ sites at 5.14, 5.35 and 6.02 Å. Water molecules replacing carbonates or as liquid inclusion of growth solution in local crystal imperfections may be responsible for the variety of orthorhombic and isotropic CO₂⁻ species, respectively.     

Extraslice spin tagging (EST) magnetic resonance imaging for the determination of perfusion

A new magnetic resonance technique to measure perfusion is described in detail. The means by which this is done is to invert all the spins in the radiofrequency RF coil with a non-spatially selective pulse and immediately re-invert the spins in the imaging plane. The net effect is that the spins in the imaging plane experience minimal perturbation of their magnetization while the spins outside the plane (extraslice) are inverted, or tagged. Tagged spins that flow into the imaging plane before image data are acquired decrease the signal intensity in the imaging plane when compared with an image in which the inflowing spins are not tagged. This decrease in signal can be used to calculate the number of spins that have flowed into the imaging plane, i.e., can be used to calculate the perfusion in mL x 100 g(tissue)(- 1)x min(-1). The extraslice spin tagging (EST) magnetization preparation period was coupled with a fast imaging sequence to obtain perfusion maps for normal volunteers.     

Estimation of age from human sternum: an autopsy study on a sample from South India

Age estimation is one of the main parameters in the evaluation of skeletal remains in forensic anthropology casework. The present investigation is an attempt to study the fusion of manubrium and xiphoid process with mesosternum in 118 sterna (67 males and 51 females) of known age obtained during autopsy in South Indian population. The male samples were aged between 25 and 74?years and the females between 20 and 80?years. The fusion is studied to derive standards for the estimation of age from sternum. The results indicate that, with advancing age, the proportion of sternum with fusion of manubrio-mesosternal and mesosterno-xiphisternal junctions increases in males and females. A larger proportion of sterna showed fusion of mesosterno-xiphisternal junction than manubrio-mesosternal junction in different age groups. Fusion of manubrio-mesosternal and mesosterno-xiphisternal junctions was proportionately commoner in males than females. None of the sterna aged below 30?years showed fusion of mesosterno-xiphisternal junction. Nonfusion of mesosterno-xiphisternal junction was reported till the age of 48?years in males and 46?years in females. Manubrio-mesosternal junction was observed to be very variable with regard to fusion status as the joint remained unfused even in the elderly ages. Based on the variability of the fusion of manubrio-mesosternal and mesosterno-xiphisternal junctions observed in the study, it can be concluded that the sternum alone is not reliable for estimation of age in South Indian population.     

Electron spin resonance measurements of blood caeruloplasmin and iron transferrin levels in patients with non-Hodgkin's lymphoma.

Caeruloplasmin and iron transferrin level were measured in blood of patients with non-Hodgkin's lymphoma in different stages of disease activity and compared with erythrocyte sedimentation rate and NAP level in the same samples. It was found that both caeruloplasmin level and sedimentation rate showed a slight increase in mean level in patients with active disease as compared with those in remission, particularly in the group of patients with poorly or undifferentiated diffuse disease. No difference was observed in levels of iron transferrin or NAP. Both caeruloplasmin and sedimentation rate showed occasional abnormal values in patients in remission but in most cases where both were elevated the patients subsequently entered a more active phase of the disease.     

MRI检查锁骨内侧端用于法庭确定骨龄:一种4min的新方法

目的 3 T MRI检查锁骨用于法庭确定骨龄的前瞻性研究,并与X线平片对照。材料与方法 2名观察者研究121名健康者(11～30岁)4种MRI序列及3张平片。结果 X线平片有确定骨龄价值的影像数量(后前位68.7%,斜位     

Magnetic resonance imaging of the medial extremity of the clavicle in forensic bone age determination: a new four-minute approach

Objectives  

The use of 3T magnetic resonance imaging (MRI) of the clavicle in forensic bone age determination was prospectively examined and compared with plain radiography.     

Dynamic electron spin resonance (ESR) imaging of the distribution of spin labeled dextran in a mouse

The nitroxide group 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was covalently bound to a dextran via an N-acetamido linkage to produce a novel spin probe, TEMPO-dextran (TEMPO-DX), which circulates for long time periods in an animal without metabolic degradation. TEMPO-DX was stable in mice, while small TEMPO analogs quickly disappeared after administration. Since dextran was reduced somewhat in size during synthesis, the resultant spin-labeled dextran could be excreted through the kidney. A strong L-band electron spin resonance signal was obtained shortly after Intravenous administration of TEMPO-DX into the tail vein of a mouse, from which three-dimensional images of specific organs were calculated. The signal was found to persist for well over 1 h.     

Estimation of fetal age at death from the basilar part of the occipital bone

The purposes of this study are to examine documented fetal skeletal remains of Japanese, to measure the basilar part of the occipital bone, and to develop diagnostic standards for estimating fetal age at death which can be applied to poorly preserved skeletons. The sample is composed of 272 Japanese individuals of the early to middle twentieth century, whose ages were recorded in months from gestations of 5 to 11?months. The measurement items used here are the length, breadth, and index of the basilar part. The regression equations of gestational age in months for one or two variables were calculated. The results indicated that it is possible to use the regression equations to estimate the age at death of fetuses directly from the basilar part measurements. Another indicator for estimating age at death from the basilar part is the ratio of the width to the length, which was here expressed as the index of the basilar part. The width exceeded the length at 7?months and the basilar part changed with age from an anteriorly posteriorly long shape to a bilaterally wide one. It is concluded that the basilar part is a good indicator for estimating the fetal age at death.     

Multiple spin echo magnetic resonance imaging of the brain

Advantages of 3D multiecho: 1. High signal to noise ratio which is useful for: a) Long TE b) Short TR c) Thin slices 2. Reduced paradoxical enhancement of blood vessels 3. Contiguous slices 4. Number of slices per scan is not reduced by short TR or long TE 5. Thin slices easily generated 6. A short TR multiecho sequence can produce a spectrum of images reflecting a range of both T1 and T2 weighting in the same scan. This information can often improve specificity. Disadvantages of 3D multiecho: 1. Increased motion sensitivity of 3D acquisitions 2. Scan times increase with TR.     

Sex determination from chest measurements in a sample of Egyptian adults using Multislice Computed Tomography

BackgroundIn forensic sciences to determine one's sex is quite important during the identity defining stage. The reliability of sex determination depends on the completeness of the remains and the degree of sexual dimorphism inherent in the population. Computed Tomography is the imaging modality of choice for two- and three-dimensional documentation and analysis of many autopsy findings.ObjectiveThe aim of the present work was to assess the reliability of Three-dimensional Multislice Computed Tomography (3D MSCT) to determine sexual dimorphism from certain chest measurements; sternum and fourth rib using the 3D MSCT and to develop equations for sex determination from these bones among adult Egyptians sample.Subjects and methodsThe present study was performed on 60 adult Egyptians. Their age ranged from 21 up to 74 years and they were equally divided between both sexes. Sixty virtual chests (reconstructed Multislice Computed Tomography 3D images) were examined for detection of Sternal measurements; Manubrium length (ML), Sternal body length (BL), Manubrium width (MW), Sternal body widths(BWa&BWb), Sternal area (SA) [(ML + BL) × (MW + BWa + BWb)/3]and Fourth rib width (FRW).ResultsAll the studied measurements were significantly higher in males than in females. Multiple regression analysis was used to and three significant regression equations were developed for predicting sex using the different studied chest measurements; the sternal measurements, the sternal area and the widths of the right and left fourth ribs with their accuracies 96.67%.95.0%.72.68% respectively.ConclusionSterunm and fourth rib width revealed significant metric sex differences with the use of Multislice Computed Tomography 3D images thus provide a great advantage in the analysis of skeletal remains and badly decomposed bodies.