Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017.

In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (106Ru). The range of concentrations varied from some tenths of µBq·m-3 to more than 150 mBq·m-3 The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne 106Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location. Based on airborne concentration spreading and chemical considerations, it is possible to assume that the release occurred in the Southern Urals region (Russian Federation). The 106Ru age was estimated to be about 2 years. It exhibited highly soluble and less soluble fractions in aqueous media, high radiopurity (lack of concomitant radionuclides), and volatility between 700 and 1,000 °C, thus suggesting a release at an advanced stage in the reprocessing of nuclear fuel. The amount and isotopic characteristics of the radioruthenium release may indicate a context with the production of a large 144Ce source for a neutrino experiment.

The correlation between parental education and their knowledge of asthma.

OBJECTIVE: To evaluate the impact of parental education on the success of Asthma Educational Intervention (AEI). METHODS: AEI took place after the children's hospitalisation. Parental asthma knowledge was assessed at three time points: before AEI, immediately after, and 12 months later. The Intervention (I) group of parents (N=231) received complete AEI. The Control (C) group of parents (N=71) received instructions for proper use of asthma medications and the handbook. RESULTS: Asthma knowledge in I group increased immediately after the AEI (p<0.01), and had not changed (p>0.05) 12 months later. There were four subgroups in group I divided based on education level: elementary school, high school, college, and university degrees. Taking into account the parental education level, there were no differences in the baseline and final knowledge of asthma between subgroups (p>0.05). The number of asthma exacerbations decreased after AEI (5.96:2.50, p<0.01), regardless of the parental degree. Knowledge of asthma in group C did not improve during the study (p=0.17). Final asthma knowledge was higher in group I compared to group C (p<0.01). CONCLUSION: The parental education level did not influence the level of asthma knowledge after the AEI. The motivation and the type of asthma education had the greatest input on the final results. PRACTICE IMPLICATIONS: All parents should be educated about asthma regardless of their general education.

Radioactivity in the Mediterranean flora of the Kastela Bay, Croatia.

This study refers to background activity concentrations of (238)U, (226)Ra, (232)Th, (208)Tl, (40)K, and (137)Cs in soil and plants of the Kastela Bay, Croatia and related plant-soil concentration ratios (CR's). Fourteen different Mediterranean plant species growing in natural conditions have been included and were divided into three major plant groups (grasses and herbs, shrub, tree). Radionuclide activity concentrations were determined by means of high resolution gamma-ray spectrometry. Soil parameters (pH, electrical conductivity, and organic matter content) were also analysed. CR ranges were within one order of magnitude for (40)K (10(-2)-10(-1)), (238)U, and (226)Ra (10(-3)-10(-2)), and two orders of magnitude for (232)Th, (208)Tl, and (137)Cs (10(-4)-10(-2)). There was no statistical difference between the plant groups in radionuclide uptake. Overall statistical analyses indicated a moderate negative relationship between soil concentrations and CR values, and no relationship with soil parameters, except a negative one for (137)Cs. Comparison with literature showed more agreement with studies that were done in the Mediterranean than with ICRP and IAEA databases. Our data not only describe the natural radioactivity of the Bay, but also create a dataset that could be relevant for further radioecological assessments of the Kastela Bay.

Pyramidal lobe of the human thyroid gland: an anatomical study with clinical implications.

The presence, position, extent, relationships to neighboring structures and size of the human pyramidal lobe were investigated in 58 human post-mortem specimens in order to determine the variability of this structure. The pyramidal lobe is found in 55.2% of cases as a single conical extension of the thyroid gland. It was present more often in male (53.1%) than in female (46.9%) specimens and located slightly more often on the left side of the midsagittal plane (53.1%). According to the origin and location of its base, we defined five types of pyramidal lobe, with the left-sided types (Types III and IV) being predominant. The pyramidal lobe was 22.6 mm long, 11.2 mm wide and 3.6 mm thick (mean values). The means of all measured parameters were higher in female than in male specimens (pyramidal lobe was 2.3 mm longer, 1.6 mm wider and 0.4 mm thicker in female specimens) but these differences were not significant. In addition, we found that the size of the pyramidal lobe was dependent on the presence of a fibrous or muscular band that may represent a fibrous remnant of the thyroglossal duct or the levator glandulae thyroideae muscle. The pyramidal lobe was four times longer and its base was two and a half times wider and three times thicker when it was associated with this band. We believe that our data can be used to perform safer and more effective partial thyroidectomy in order to preserve thyroid function after surgical treatment.

Fine structure of the absorbed dose rate monitored in Zagreb, Croatia, in the period 1985-2011.

We report on the fine structure of the absorbed dose rate D which was measured and recorded on a daily basis at the Institute for Medical Research and Occupational Health in Zagreb, Croatia, throughout the period 1985-2011. After the Chernobyl accident, D increased steeply by a factor of 3.5, but this is the only prominent feature in the D versus time (t) curve. In the absence of accidental conditions, the D(t) is flat and amounts to 30-35 pGy/s. Despite the apparent plainness of D(t), its Fourier transform reveals several periodic modulations hidden in the noise. Some of the corresponding periods (6 and 12 months) can be related to seasonal atmospheric changes but this is not the case with the other periods identified (9.3, 13.7, 15.7, 20, 31, and 39 months). These are found to agree well with literature data on periodicities in solar activity, which implies that they are most probably linked to variations in the atmospheric production of (7)Be by cosmic rays.

Clinical and histopathological study of angiogenesis in multiple myeloma.

PURPOSE: Angiogenesis is an essential component in the growth and progression of multiple myeloma (MM). We studied the clinical significance of angiogenesis in patients with MM estimated by precise counting of the number of vessels (i.e. microvessel density, MVD) and compared these results with the results obtained using semi-quantitative grading of angiogenesis. METHODS: Fifty-nine newly diagnosed cases of MM were analyzed with respect to clinical features, laboratory findings, histological features, angiogenesis parameters, and response to treatment. Bone marrow microvessels were examined using immunohistochemical staining for CD34. Bone marrow angiogenesis was estimated by two different methods. The mean number of vessels per area in each sample was characterized as the MVD. Microvessels were counted manually on light microscopy in 3 hot spots at ×400 magnification. Semiquantitative estimation of angiogenesis was based on visual assessment of slides at ×100 magnification. Each slide was assigned as low, intermediate or high intensity of angiogenesis. RESULTS: The median MVD was 15 vessels per 3 hot spots (range 1-89). Intensity of angiogenesis was assigned as low in 24 (40.7%) patients, intermediate in 17 (28.8%) and high in 18 (30.5%). Significant correlation between intensity of angiogenesis (estimated using both methods) and histological grade, extent of bone marrow infiltration, proliferative activity of myeloma cells and poor survival was found. Semiquantitatively assessed intensity of angiogenesis additionally correlated with clinical stage. There was a statistically highly significant correlation between MVD and semi-quantitatively estimated intensity of angiogenesis (p <0.001). CONCLUSION: Tumor-associated angiogenesis is an important prognostic feature in MM and should be routinely done on bone marrow biopsies of these patients. Simple semiquantitative grading of angiogenesis can be recommended for daily practice, as an alternative method for complicated and time-consuming estimation of MVD.

Contrast-enhanced angiographic cone-beam CT of cerebrovascular stents: experimental optimization and clinical application.

BACKGROUND AND PURPOSE: With modern imaging techniques, visualization of neurovascular stents remains challenging. We present a method for contrast-enhanced C-arm CBCT that provides detailed and simultaneous visualization of neurovascular stents and host arteries. MATERIALS AND METHODS: CBCT was performed with a rotational angiography system by acquiring 620 projection frames over a 200° arc at 80 kVp and a total of 260 mAs. A superselective intra-arterial contrast injection protocol was optimized in swine experiments and implemented in 57 clinical examinations. High-resolution 3D reconstructions were evaluated by 3 blinded interventional neuroradiologists. Reviewers rated the images by answering questions related to both the quality of the stent and artery visualization and the clinical utility of the images. Raw agreement statistics, ICC, and κ statistics were computed for the questionnaire results. RESULTS: Of 57 clinical evaluations, 5 were not evaluated due to the use of large balloon-mounted stents (n = 4) and a failed contrast injection (n = 1). In 50 of 52 evaluated examinations, the reviewers agreed that simultaneous stent and vessel visualization was of diagnostic quality. There was strong agreement that stent-vessel wall apposition could be assessed (κ = 0.79). CBCT detected contrast filling defects (κ = 0.85) and vascular calcification (κ = 0.68). Artifacts resulting from the aneurysm coil mass impaired the delineation of adjacent structures (κ = 0.72). CONCLUSIONS: We have developed a technique that enables simultaneous clinically useful imaging of neurovascular stents and their host arteries that is unobtainable with other current imaging modalities. Further improvements are required to reduce artifacts from large coil masses due to x-ray scattering.

Field-induced self-assembly of suspended colloidal membranes.

We report experiments that probe the self-assembly of micrometer-size colloids into one-particle-thick, robust, and self-healing membranes. In a magic-angle precessing magnetic field, superparamagnetic spheres experience isotropic pair attraction similar to the van der Waals force between atoms. But the many-body polarization interactions among them steer an ordered aggregation pathway consisting of growth of short chains, cross-linking and network formation, network coarsening, and consolidation of membrane patches. This generic aggregation scenario can be induced in any particles of large enough susceptibility.

Investigation of properties of electrochemically synthesized iron oxide nano-powders.

Nano-sized powders of iron oxides have been synthesized electrochemically at temperatures in the range of 295-361 K, and current densities in the range of 200-1000 mA dm(-2). The structure and morphology of the powders were investigated by X-ray diffraction and scanning electron and transmission electron microscopy techniques. Their infrared absorption spectra, specific heat C(p)(T) and magnetic susceptibility chi(T) temperature dependences are also determined. The obtained powders consist of two phases, each possessing distinguished characteristics: the one formed of large plates and the other of whiskers. By appropriate adjustment of the synthesis conditions, it is possible to change features and relative abundances of the two phases, and that way to control morphology and other powder properties. Relaxation and transformation of the phases under external influences was also investigated, and the optimal procedure for preparation and stabilization of iron oxide nano-sized powders with desired characteristics was established.

Hierarchical self-assembly of nematic colloidal superstructures.

We show that colloidal superstructures could be assembled in mixtures of large and small colloidal particles dispersed in a nematic liquid crystal. Using elastic interaction of small colloidal particles with the disclination lines we succeed to demonstrate how one can decorate with small particles a topological matrix of defect rings and loops formed by an array of large colloidal particles. Our simulations show that this concept of colloidal self-assembly in nematics could be extended down to the nanoscale particles.

Interactions of quadrupolar nematic colloids.

We present experimental and theoretical study of colloidal interactions in quadrupolar nematic liquid crystal colloids, confined to a thin planar nematic cell. Using the laser tweezers, the particles have been positioned in the vicinity of other colloidal particles and their interactions have been determined using particle tracking video microscopy. Several types of interactions have been analyzed: (i) quadrupolar pair interaction, (ii) the interaction of an isolated quadrupole with a quadrupolar chain, and (iii) the interaction of an isolated quadrupolar colloidal particle with a two-dimensional (2D) quadrupolar crystallite. In all cases, the interactions are of the order of several 100k(B)T for 2 microm particles, which gives rise to relatively stable 2D colloidal crystals. The experimental results are compared to the predictions of Landau-de Gennes theory and we find a relatively good qualitative agreement.

2D interactions and binary crystals of dipolar and quadrupolar nematic colloids.

In this Letter, we demonstrate that the symmetry of the elastic interaction between the dipolar and quadrupolar colloidal particles in the nematic liquid crystal leads to a novel variety of 2D nematic "binary" colloidal crystals, which have not been observed in any colloidal system. The dipolar-quadrupolar interaction is highly anisotropic and shows a power-law dependence when the particles approach each other along the director field with a pair-binding energy of the order of several thousands of k(B)T for 4 microm diameter colloids.

Brain imaging with a flat detector C-arm : Technique and clinical interest of XperCT.

INTRODUCTION: We present the first clinical results from brain tissue imaging with a novel functionality in the angiography room, the XperCT. METHODS: XperCT is a flat detector C-arm volume acquisition functionality integrated with the angiography equipment. We assessed brain images from 42 patients examined with computed tomography (CT) and XperCT. RESULTS: In all patients, XperCT had significantly more beam hardening and reconstruction artifacts than CT, in particular in the posterior fossa. Contrast resolution was better on CT images. Hemorrhage, edema, and ventricular size could be assessed with XperCT in all patients, but CT was superior also in this aspect. In four of the last 12 cases, after the latest software upgrade, it was possible to differentiate between supra-tentorial grey and white substance on XperCT images. CONCLUSION: CT was superior to XperCT regarding brain soft tissue imaging. However, XperCT could in some cases discriminate between grey and white substance. XperCT is a useful new functionality in interventional neuroradiology. In the clinical setting, it improves patient safety by allowing almost instant access to CT-like brain imaging in the angiography room. It can be life saving in situations where complications during an interventional procedure prompt for immediate action.

Total tissue lactate dehydrogenase activity in endometrial carcinoma.

Lactate dehydrogenase (LDH) is essential for continuous glycolysis necessary for accelerated tumor growth. The aim of this study was to reconsider if assay of total tissue activity of this enzyme could be useful as marker for endometrial carcinoma (EC). Activity of LDH was measured spectrophotometrically in homogenate supernatants of uterine tissue samples of 40 patients (10 normal endometria, 27 normal myometria, and 33 EC), including 30 matched pairs. Data obtained were analyzed in relation to clinical and histopathologic findings and compared with our previously published results on the tissue levels of the same enzyme in ovarian cancer and on the proteolytic activity of dipeptidyl peptidase III (DPP III) in EC (suggested biochemical indicator of this malignancy). Significantly increased (1.8-3.0 times; P < 1 x 10(-4)) LDH activity was observed in EC samples if compared with normal uterine tissues. This rise was not related to the clinicopathologic findings, however. In contrast to previous results on LDH in ovarian carcinomas, a significant rise in LDH activity was found already in grade 1 EC. Using the cutoff value of 1.06 U/mg, diagnostic sensitivity of 82%, specificity of 100%, and accuracy of 91% for total tissue LDH assay have been calculated. A correlation of tissue's LDH and DPP III activities was found, and their combined assay for EC showed increased diagnostic sensitivity (94%) and accuracy (96%).

Bimonthly 24 h infusion of high-dose 5-fluorouracil vs EAP regimen in patients with advanced gastric cancer. A randomized phase II study.

BACKGROUND: To investigate the activity and toxicity of high dose (HD) infusional 5-FU in comparison to EAP regimen as first-line chemotherapy in patients with advanced gastric cancer. PATIENTS AND METHODS: Histologically confirmed measurable advanced gastric cancer, age < 72 yr, ECOG performance status 0-2, no prior chemo- and radiotherapy, adequate organ functions. TREATMENT: EAP arm: doxorubicin (40 mg/m(2)), etoposide (360 mg/m(2)), and cisplatin (80 mg/m(2)) every 28 d; HD 5-FU arm: 5-FU 2.6 g/m(2) 24 h infusion, biweekly. RESULTS: Sixty patients were randomized. Patient characteristics (arms EAP/HD 5-FU): Median age 57/55 yr, median PS 1/1, LAD (patients) 3/8, M1 (patients) 27/22. Median number of cycles (range): EAP arm 4 (2-8), HD 5-FU arm 2 (1-8). Worst toxicity per cycle (grade 3 and 4 in%): Neutropenia 20/3, thrombocytopenia 9/0, anemia 9/13, diarrhea 3/10, nausea 17/7, vomiting 10/0 for EAP and HD 5-FU arms, respectively. All patients were eligible for response in both arms. Confirmed response rate (95%CI): EAP arm 34% [16-50%]/HD 5-FU arm 10% (0-21%), no change: 46/40%, progression of disease: 20/50, respectively. Overall survival (range): EAP arm A 7 mo [3-27], HD 5-FU arm 6 mo (4-25). CONCLUSIONS: Infusional HD 5-FU showed a low incidence of severe toxicity. But given the low efficacy of 5-FU in the dosage we applied in the study, it cannot be recommended as a single treatment for further studies. Assessment of higher dose intensity and/or dose density of 5-FU, with introduction of other active drugs in combination, could be an option for further studies.

Electrically tunable diffraction of light from 2D nematic colloidal crystals.

We show that diffraction of visible light from 2D dipolar nematic colloidal crystals can be tuned electrically. When the external electric field of approximately 1 V/microm is applied in a direction perpendicular to the plane of the 2D colloidal crystal, the induced strain is highly anisotropic, and the inter-colloidal spacing changes by as much as 20% along one direction and approximately 2% along the perpendicular one. Although the speed of response is in the range of several seconds, this novel mechanism could provide interesting photonic applications.

Entangled nematic colloidal dimers and wires.

It has been predicted, but never confirmed, that colloidal particles in a nematic liquid crystal could be self-assembled by delocalized topological defects and entangled disclinations. We show experimentally and theoretically that colloidal dimers and 1D structures bound by entangled topological defect loops can indeed be created by locally thermally quenching a thin layer of the nematic liquid crystal around selected colloidal particles. The topological entanglement provides a strong stringlike binding, which is ten thousand times stronger compared to water-based colloids. This unique binding mechanism could be used to assemble resonator optical waveguides and robust chiral and achiral structures of topologically entangled colloids that we call colloidal wires.

Observation of condensed phases of quasiplanar core-softened colloids.

We experimentally study the condensed phases of repelling core-softened spheres in two dimensions. The dipolar pair repulsion between superparamagnetic spheres trapped in a thin cell is induced by a transverse magnetic field and softened by suitably adjusting the cell thickness. We scan a broad density range and we materialize a large part of the theoretically predicted phases in systems of core-softened particles, including expanded and close-packed hexagonal, square, chainlike, stripe or labyrinthine, and honeycomb phase. Further insight into their structure is provided by Monte Carlo simulations.

Two-dimensional dipolar nematic colloidal crystals.

We study the interactions and directed assembly of dipolar nematic colloidal particles in planar nematic cells using laser tweezers. The binding energies for two stable configurations of a colloidal pair with homeotropic surface alignment are determined. It is shown that the orientation of the dipolar colloidal particle can efficiently be controlled and changed by locally quenching the nematic liquid crystal from the laser-induced isotropic phase. The interaction of a single colloidal particle with a single colloidal chain is determined and the interactions between pairs of colloidal chains are studied. We demonstrate that dipolar colloidal chains self-assemble into the two-dimensional (2D) dipolar nematic colloidal crystals. An odd-even effect is observed with increasing number of colloidal chains forming the 2D colloidal crystal.