Improved methods of measurement and analysis of conversion electron and β-particle spectra

A general statistical test of the stability of measurement conditions was demonstrated on the β-spectra of ²⁴¹Pu cumulated during four years. The α- and γ-ray spectroscopy indicated stability of the ²⁴¹Pu source. Monte Carlo modelling of individual collision events clarified the role of electron scattering and energy losses within a radioactive source down to energies of several hundreds of eV. The impact ionization by β-particles of carbon and oxygen atoms in a surface contamination layer on the ²⁴¹Pu and ⁶³Ni sources was observed.     

Formation and decay of the E1′ center and of its precursor

The E₁′ center has been used for ESR dating of quartz with assuming that the signal intensity increases with natural radiation dose as those of other ESR signals do. However, this simple assumption is not necessarily correct. Formation and decay of the E₁′ center are closely related with its precursor, diamagnetic oxygen vacancies. Gamma ray of large dose (>100 kGy) creates oxygen vacancies giving little dose rate effect, which, therefore, might be useful for dating of granites and high dose dosimetry.     

Radiologic Detection and Differentiation of Edema

ln contrast to 5 the techniques describcd above, the noninvasive and available chest radiograph has been shown to be of considerable clinical value in the detection of edema [24, 25] . The ability~6 of the radiologist to quantitate edema from the chest radiograph was first demonstrated objectively by Milne [26] who compared assessments of extrava-     

Is identification of malignant lesions of the liver and of hemangiomas possible by Doppler ultrasonography and radionuclide angiography?

The aim of this study was to try to diagnose malignant liver lesions and hemangiomas by means of vascularisation and perfusion studies. The study was performed in 32 patients with hepatocellular carcinoma (HCC), in 74 with metastatic liver carcinoma (MLC) and in 40 with hemangiomas (H). Color Doppler ultrasonography (DUS) was done with an ATL Ultramark 9 apparatus with convex probe 2.5 MHz using pulse and DUS. Hepatic radionuclide angiography (HRA) was performed with bolus injection of 740 MBq (99m)Tc-pertechnetate, (1 min, 1 f/s), using ROTA scintillation camera and MicroDelta computer. Hepatic perfusion index (HPI) indicated the percentage of the portal blood inflow to the liver. Our results showed that in HCC and MLC there was a decrease of portal inflow while arterial inflow was increased resulting in pulse arterial wave velocity increase and in continuous venous waves velocity in the tumors. There was significant linear correlation between the increase of the arterial inflow and the arterial pulse wave found in the center and in the margin of the tumors. In hemangiomas, hepatic perfusion index related to arterial inflow was within normal range. In conclusion, our results suggest that HCC and MLC have specific characteristics in vascular and/or perfusion studies while hemangiomas show normal liver parenchyma findings.     

Long‐term accumulation and microdistribution of uranium in the bone and marrow of beagle dog

The accumulation and microdistribution of uranium in the bone and marrow of Beagle dogs were determined by both neutron activation and neutron‐fission analysis. The experiment started immediately after the weaning period, lasting till maturity. Two animal groups were fed daily with uranyl nitrate at concentrations of 20 and 100?µg?g^?1 food. Of the two measuring techniques, uranium accumulated along the marrow as much as in the bone, contrary to the results obtained with single, acute doses. The role played by this finding for the evaluation of radiobiological long‐term risks is discussed. It was demonstrated, by means of a biokinetical approach, that the long‐term accumulation of uranium in bone and marrow could be described by a piling up of single dose daily incorporation.     

Role of DWI and MRS in diagnosis of Alzheimer’s and pre-Alzheimer’s disease

Background and purpose

Alzheimer’s disease (AD) is a major cause of dementia in elderly affecting about 30% above the age of 85 years, while mild cognitive impairment (MCI) is the impairment in cognitive functions with intact daily life activities which is described as the preclinical phase of AD.

Brain weight in completed suicide and other cases of death–comparison of recent and previous studies

Background

The weight of human brains is subject of numerous scientific research studies particularly in anatomy, pathology, and forensic medicine. Just a few investigations deal with a possible correlation between psychiatric disorders, especially suicidality, and brain weight. The results are contradictory.

Aims

This study aims to find out if postmortem brain weight is higher in suicide victims considering the discrepancies of previous studies.

Method

In a retrospective study, the weight of brains obtained by autopsies performed in the Institute of Legal Medicine in Frankfurt, Germany, was evaluated. Data of 99 suicide cases (64 males, 35 females) were compared with those obtained from similar number cases of sudden death in a matched pair analysis. In each case, body weight, height, and body mass index were also taken into account.

Results

No significant differences in brain weight were found in suicide victims compared to those of the control group.

Conclusions

The brain weight depends on various parameters such as gender, age, body height, and weight. The selection criteria for suicide cases as well as for the corresponding control population are essential in evaluating the brain weight in suicide.     

Feasibility and availability of ⁶⁸Ga-labelled peptides

(68)Ga has attracted tremendous interest as a radionuclide for PET based on its suitable half-life of 68 min, high positron emission yield and ready availability from (68)Ge/(68)Ga generators, making it independent of cyclotron production. (68)Ga-labelled DOTA-conjugated somatostatin analogues, including DOTA-TOC, DOTA-TATE and DOTA-NOC, have driven the development of technologies to provide such radiopharmaceuticals for clinical applications mainly in the diagnosis of somatostatin receptor-expressing tumours. We summarize the issues determining the feasibility and availability of (68)Ga-labelled peptides, including generator technology, (68)Ga generator eluate postprocessing methods, radiolabelling, automation and peptide developments, and also quality assurance and regulatory aspects. (68)Ge/(68)Ga generators based on SnO(2), TiO(2) or organic matrices are today routinely supplied to nuclear medicine departments, and a variety of automated systems for postprocessing and radiolabelling have been developed. New developments include improved chelators for (68)Ga that could open new ways to utilize this technology. Challenges and limitations in the on-site preparation and use of (68)Ga-labelled peptides outside the marketing authorization track are also discussed.     

Value of diffusion-tensor imaging and fiber tractography in the diagnosis and follow-up of Marchiafava–Bignami disease

Marchiafava–Bignami disease is a rare alcohol-related disorder that results in progressive demyelination and necrosis of the corpus callosum. The diagnosis is based on clinical profiles and neuroimaging features. We report two cases of Marchiafava–Bignami disease studied with MRI, including diffusion-tensor imaging and fiber tractography. We observed decreased fractional anisotropy values in the corpus callosum and clear white matter fiber derangement in the chronic stage. However, extensive corpus callosum involvement in FLAIR sequences, low ADC values and normal FA at presentation are not good predictors of poor outcome.     

Analysis of Heart RateVariability and its Application

心率变异性（ＨＲＶ）可用于评价健康者和病人自主神经系统的波动。本文论述ＨＲＶ分析方法、测量标准、正常参考值、产生机理、生理解释及其应用。ＨＲＶ在临床可以作为预测急性心梗后死亡和糖尿病人早期神经损伤的指标；在航天医学研究中，可以提供失重和模拟失重后自主神经调节变化的信息，可评价各应激试验的特因耐力，可用于研究心血管系统的调节机制和评定失重对抗措施的训练效果     

The Incorporation of Thymidine into DNA and Effects of γ-radiation

Summary

Labelled thymidine is incorporated into Krebs II ascites cells in vitro for a limited period only. It has been shown that this failure results from a progressive decay in the activity of the enzymes which phosphorylate thymidine. Irradiation with 10 000 r reduces the rate of incorporation of thymidine into the cells and lowers the total amount bound in DNA during the period in which the cells remain metabolically active. The effect of the radiation cannot be attributed to a lack of availability of the precursor within the cells, nor to any damage resulting in loss of activity of the thymidine kinases. It is suggested that radiation slows down the incorporation of TTP into DNA and that the observed kinetics of the phosphorylation reactions can be explained in terms of competitive inhibition of the thymidine kinase by TTP.     

Ossification and pseudoepiphysis formation in the “nonepiphyseal” end of bones of the hands and feet

Metacarpals, metatarsals, and phalanges were studied to assess the developmental morphology of secondary ossification in the nonepiphyseal ends of these bones as well as the formation of the pseudoepiphysis as an epiphyseal ossification variant. Both direct ossification extension from the metaphysis into the epiphysis and pseudoepiphysis formation preceded, and continued to be more mature than, formation and expansion of the classic epiphyseal (secondary) ossification center at the opposite end of each specific bone. Direct metaphyseal to epiphyseal ossification usually started centrally and expanded hemispherically, replacing both physeal and epiphyseal cartilage simultaneously. In contrast, when remnants of physis were retained, while juxtaposed epiphyseal cartilage was replaced, a pseudoepiphysis formed. There were three basic patterns of pseudoepiphysis formation. First, a central osseous bridge extended from the metaphysis across the physis into the epiphysis and subsequently expanded to create a mushroom-like osseous structure. In the second pattern a peripheral osseous bridge formed, creating either an osseous ring or an eccentric bridge between the metaphysis and the epiphysis. In the third pattern, multiple bridging occurred. In each situation the associated remnant physis lacked typical cell columns and was incapable of significantly contributing to the postnatal longitudinal growth of the involved bone. Pseudoepiphyses were well formed by 4–5 years and coalesced with the rest of the bone months of years before skeletal maturation was attained at the opposite epiphyseal end, which ossified in the typical pattern (i.e., formation of a secondary center de novo completely within the cartilaginous epiphysis). This process may also affect the development and appearance of ossification within the longitudinal epiphyseal bracket (delta phalanx).     

Combined Effect of Noise and Vibration on Articulation of Chinese Syllable

为研究噪声、振动复合因素对汉语发音的影响，对汉语单音节的语音特征变化进行了研究。本研究设计了获取噪声与振动复合因素下发音的实验，实验分噪声与振动复合因素、单独噪声、单独振动、正常对照四种条件，并建立了一套语音处理硬件系统，编制了语音分析程序和显著性检验程序。结果表明，噪声与振动复合因素下，汉语语音的基频、能量、时长与对照组和单因素组比较都有显著性增加。这一结果对于航天中语音识别系统的设计具有一定的参考价值。     

Radiation treatment of exhaust gases—VI. Effects of CO and H2 on the removal of NO and NO2 in the moist mixture of O2 and N2

The effects of CO and H₂ on the removal of NO and NO₂ were studied in the mixture of H₂O, O₂ and N₂ irradiated by electron beams of 1.5 MeV energy at 120°C. In the NOH₂OO₂N₂ mixture, the NO removal and the corresponding NO₂ formation were enhanced markedly by the addition of CO or H₂, but not by CO₂. In the NO₂H₂OO₂N₂ mixture, the NO₂ removal was markedly suppressed by the addition of CO up to 0.88% and was not observed in the presence of CO above 1.5%. These effects of CO on the removal of NO and NO₂ may be brought about by the scavenging of OH radical by CO to produce H atom, leading to the formation of HO₂ radical which oxidizes NO to NO₂.     

Intra and intersession repeatability and reliability of the S-Plate® pressure platform

AimThe aim of this study was to assess the repeatability and reliability of the S-Plate® pressure platform in a group of healthy subjects.Material and methodsForty subjects, free from physical conditions that would affect normal gait, walked along a five-meter corridor while data were recorded from the pressure platform. A total of 10 steps (five each side) were obtained as well as five static trials; the same measurements were repeated one week later. Peak and mean plantar pressures and contact area were recorded for both dynamic and static trials. Additionally, weight supported on each limb was documented during static trials. To assess intrasession and intersession repeatability and reliability, the intraclass correlation coefficients (ICCs) and coefficient of variation (CoV) were calculated.ResultsTaking the ICC values into account, every static and dynamic variable analysed showed moderate to excellent reliability and the CoV values were all below 12%.ConclusionMeasurements of either static or dynamic plantar pressure variables with the S-Plate® pressure platform show good repeatability and reliability, and so it is useful for comparing steps within and between sessions.     

Organ distribution of 4-MEC,MDPV, methoxetamine and α-PVP: comparison of QuEChERS and SPE

Purpose

An organ distribution investigation was carried out on two deceased (A and B) who consumed 4-methylethcathinone (4-MEC), methylenedioxypyrovalerone (MDPV), methoxetamine (MXE) and α-pyrrolidinopentiophenone (α-PVP).

Methods

The detection of the aforementioned drugs in the specimens was performed on a liquid chromatography–tandem mass spectrometry system. Two different extraction methods were compared with each other—a quick, easy, cheap, effective, rugged and safe (QuEChERS) approach and an automated Instrument Top Sample Preparation-solid phase extraction (ITSP-SPE). Standard addition method was used to quantify the drugs.

Results

4-MEC, MDPV and MXE were detected in all collected tissues and body fluids of the two deceased. α-PVP was also detectable in deceased A. Deceased A showed femoral blood concentrations of 97 µg/L 4-MEC, 396 µg/L MDPV, 295 µg/L MXE and 4 µg/L α-PVP measured after extraction by QuEChERS and 118 µg/L 4-MEC, 342 µg/L MDPV, 385 µg/L MXE and 4 µg/L α-PVP measured after ITSP-SPE. Deceased B revealed heart blood concentrations of 8 µg/L 4-MEC, 3 µg/L MDPV and 2 µg/L MXE after extraction by QuEChERS and 8 µg/L 4-MEC and 1 µg/L MXE after ITSP-SPE.

Conclusions

Both preparation techniques were suitable for quantifying NPS in organ tissues and body fluids. With respect to the autopsy findings, the cause of death of deceased A was determined to be an acute intoxication with NPS. No certain cause of death could be ascertained for deceased B.

     

Trunk Kinematics and Centre of Pressure Displacement during Lateral Lifting and Lowering

Introduction Severalstudieshaveidentifiedlateralbendingofthetrunk asahighinjuryfactorforlowerbackdisorders(Marraset al.,1993;Punnetetal.,1991Andersson,1981).Moreover,theriskoflow-backpainfurtherincreases whentrunkmovementsinotherdirectionsarecoupled withlateraltrunkloading(HaasandNyiendo,1992).Comparedtoawkwardstaticpositions,wherethetrunkis twisted,dynamicloadingofthetrunk,suchasoccurs duringlifting,isbelievedtosignificantlyincreasetherisk ofinjurytothelowerback(Bigosetal.,1986).Inapreviou…     

Yields of SSB and DSB induced in DNA by Al K ultrasoft X-rays and α-particles: comparison of experimental and simulated yields

Purpose : To compare experimental yields of single strand breaks (SSB) and double strand breaks (DSB) induced in plasmid DNA in aqueous solution by f -particles and Al K ultrasoft X-rays (USX) with the corresponding yields, generated via computer simulations, for a range of mean diffusion distances of the hydroxyl radical (OH). Materials and methods : Aerobic, aqueous solutions of plasmid DNA were irradiated at 277K with 238 Pu f -particles or USX in the presence of 10 -4 to 0.33 mol dm -3 Tris and the yields of SSB and DSB determined by gel electrophoresis. Computer simulations, using Monte Carlo track-structure codes for 1.5keV electrons (CPA100) and 3.2MeV f -particle track segments (PITS), were used to obtain yields of DNA SSB and DSB at different OH scavenger conditions. Results : The experimental yield of SSB and DSB induced by AlK USX and SSB induced by f -particles and the dependences on the mean diffusion distance of the OH are in reasonable agreement with the corresponding simulated yields and their corresponding dependences. However, for DSB induced by f -particles, a significant systematic difference exists between the simulated and experimental yields over the full OH scavenging range, with the simulated yields being a factor of two to three greater than the experimental values. Conclusion : That the simulated yields of strand breaks are generally in reasonable agreement with those determined experimentally over a wide range of OH scavenging capacities, increases confidence in the use of these simulations as a valuable source of quantitative, mechanistic information on DNA damage induced at very low radiation doses.     

Radiographic features of Ewing’s sarcoma of the bones of the hands and feet

The radiographic features of Ewing's sarcoma of the bones of the hands and feet are reviewed utilizing cases obtained from the Mayo Clinic patient files and the consultation files of Drs. D.C. Dahlin and K.K. Unni. This series consists of a total of 43 cases of pathologically proven Ewing's sarcoma involving the small bones of the hands and feet. The classic radiographic features of Ewing's sarcoma in the long bones, including lytic, permeative destruction, aggressive periosteal reaction, cortical violation, and a soft tissue mass, are also seen in the bones of the hands and feet, with similar frequency. These classic features are most commonly present in lesions affecting the short tubular bones. Lesions affecting the tarsal bones more often demonstrate atypical radiographic features. These atypical radiographic appearances may play a role in the reported delay in diagnosis of Ewing's sarcoma within the tarsal bones.     

Validation methods of Fazekas and Kósa and Molleson and Cox for age estimation of the ilium in Western Mediterranean non-adult population: proposal of new regression formulas

The purpose of this study is to test the applicability of the age estimation methods of Fazekas and Kósa [1] and Molleson and Cox [2] in Western Mediterranean non-adults and to develop accurate and rapidly applied formulas for their age estimation, using a sample of 149 non-adults of known sex and age from the cemetery of San José in Granada (Spain). Measurements have been taken of the maximum length and width of each ilium for application of the formulas of Fazekas and Kósa [1] and Molleson and Cox [2]. There has been no significant intra- or inter-examiner variation in measurements. The documented age of the individuals has been underestimated with the Fazekas and Kósa method and overestimated with Molleson and Cox. Based on these findings, new formulas are proposed for the age estimation of non-adults in Western Mediterranean populations.