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A thermodynamic sorption model is used to calculate partition coefficients (K d) of radium in soils. It accounts for the dominant chemical interactions of radium with soil by assuming that non-available thermodynamic constants for radium can be replaced by those of barium. The retention processes considered include sorption on clay surfaces, on organic matter and on hydrous ferric oxide as well as the co-precipitation of radium with barium. The modelled K d values are compared to experimental K d values available in the relevant literature. The results show that the experimental K d values are within a factor of 2–3. The model is also applied to two representative German soil types. The calculated K d values agree with the finding that K d values for radium are generally low. The conclusion is that radium retention can be modelled reasonably well, but that it is necessary to account for specific properties such as the ability of radium to co-precipitate with barium and competition from other alkaline earth metals for surface sites. • Radium sorption in soils in form of the partition coefficient K d (L kg-1) is quantified with a mechanistic approach by means of geochemical calculations. • Chemical characterisation of soil solution and of soil matrix are required together with information on the mineral composition of soil. • The non-available thermodynamic constants for radium are replaced by those of barium in the model and it is necessary to account for specific properties of radium such as its ability to co-precipitate with barium and competition for surface sites with other alkaline earth metals. • The known geochemical behavior of radium can be well reproduced, namely its preferential sorption on organic matter and clays and its competition with calcium for sorption sites. • The model calculations result in low radium K d values, which are in agreement with experimentally determined K d values. [ABSTRACT FROM AUTHOR]

Aims To report feasibility, safety and effectiveness of “zero-ischemia” laparoscopic partial nephrectomy (LPN) following preoperative superselective transarterial embolization (STE) for clinical T1 renal tumors. Methods We retrospectively reviewed perioperative data of 23 consecutive patients, who underwent STE prior LPN between March 2010 and November 2012 for incidental clinical T1 renal mass. STE was performed by two experienced radiologists the day before surgery. Surgical procedures were performed in extended flank position, transperitoneally, by a single surgeon. Results Mean patients age was 68 years (range 56–74), mean tumor size was 3.5 cm (range 2.2–6.3 cm). STE was successfully completed in 16 patients 12–15 h before surgery. In 4 cases STE failed to provide a complete occlusion of all feeding arteries, while in 3 cases the ischemic area was larger than expected. LPN was successfully completed in all patients but one where open conversion was necessary; a “zero-ischemia” approach was performed in 19/23 patients (82.6%) while hilar clamp was necessary in 4 cases, with a mean warm-ischemia time of 14.8 min (range 5–22). Mean operative time was 123 min (range 115–130) and mean intraoperative blood loss was 250 mL (range 20–450). No patient experienced postoperative acute renal failure and no patient developed new onset IV stage chronic kidney disease at 1-yr follow-up. Conclusions STE is a viable option to perform “zero-ischemia” LPN at beginning of learning curve; however, hilar clamp was necessary to achieve a relatively blood-less field in 17.4% of cases. [ABSTRACT FROM AUTHOR]

Abstract: After an accidental radioactive contamination by aerosols in inhabited areas, the radiation exposure to man is determined by complex interactions between different factors such as dry or wet deposition, different types of ground surfaces, chemical properties of the radionuclides involved and building development as well as dependence on bomb construction e.g. design and geometry. At short-term, the first rainfall is an important way of natural decontamination: deposited radionuclides are washed off from surfaces and in urban areas the resulting contaminated runoff enters the sewer system and is collected in a sewage plant. Up to now the potential exposure caused by this process has received little attention and is estimated here with simulation models. The commercial rainfall-runoff model for urban sewer systems KANAL++ has been extended to include transport of radionuclides from surfaces through the drainage to various discharge facilities. The flow from surfaces is modeled by unit hydrographs, which produce boundary conditions for a system of 1d coupled flow and transport equations in a tube system. Initial conditions are provided by a map of surface contamination which is produced by geo-statistical interpolation of γ-dose rate measurements taking into account the detector environment. The corresponding methodology is implemented in the Inhabited Area Monitoring Module (IAMM) software module as part of the European decision system JRODOS. A hypothetical scenario is considered where a Radiation Dispersal Device (RDD) with Cs-137 is detonated in a small inhabited area whose drainage system is realistically modeled. The transition of deposited radionuclides due to rainfall into the surface runoff is accounted for by different nuclide-specific entrainment coefficients for paved and unpaved surfaces. The concentration of Cs-137 in water is calculated at the nodes of the drainage system and at the sewage treatment plant. The external exposure to staff of the treatment plant is estimated. For Cs-137 radiation levels in the plant are low since wash-off of cesium from surfaces is an ineffective process. [Copyright &y& Elsevier]

Abstract: Networks of monitoring stations have been set up in many European countries to detect the passage of a radioactive cloud in the event of a large-scale nuclear emergency. The layout and spatial density of these networks differs according to the needs and criteria defined by national authorities. Germany and the Netherlands decided to set up relatively dense networks for the detection of weak radioactive plumes and, additionally, environmental radioactivity from deposited aerosols. Plausible evaluation criteria are presented here to assess important properties which determine the reliability and efficiency of sections of these networks. As a test case the existing sampling design of the Dutch and German networks with 193 sensors in an area of 200 km around the nuclear power plant near the city of Lingen (Emsland) in the German federal state of Lower Saxony has been selected. For a hypothetical accident scenario 292 radioactive plumes have been simulated which are shaped by recorded weather conditions of the year 2007. To quantify the network performance frequency distributions of the proposed evaluation parameters have been analyzed. Simulation results show that 95% of the plumes are detected within 4 h after the release. Maximal values of the γ-dose rate 1 m above the ground mostly occur near the source within a radius of 5 km. However, under certain weather conditions maximal ground values may also be found more than 50 km away from the source. Within a circle of radius 90 km 98% of the recorded maximal γ-dose rates of the plumes were found by 62% of the 193 sensors. But only in a joint network of German and Dutch sensors all simulated plumes triggered an alarm. This result encourages efforts of close international collaboration, e.g. between EU member states, in network design and operation. Test series which involved the removal of sensors either randomly or in a controlled way showed that the network configuration is fit for the intended purpose of detecting a large majority of plumes. But already a small reduction in the number of sensors would degrade the performance. Whereas the joint network triggers alarms reliably, it fails to detect the true plume maxima. The assessment criteria can be used for a revision of existing networks or for planning purposes in countries such as those applying for EU membership. [Copyright &y& Elsevier]

Abstract: The plasmon resonance of metallic Au/Ag nano-alloys in the colloidal state was tuned from 400nm to 500nm using a laser irradiated technique performed directly in the liquid state. Interesting optical nonlinearities, trapping effects and spectroscopic enhancements were detected by modifying the gold molar fraction in the nano-alloys. In particular a reduction of the limiting threshold was observed by increasing the gold amount. The SERS activity of the Au/Ag alloys was tested in liquid and in solid state in presence of linear carbon chains as probe molecules. The increased Raman signals for nanoparticles with different Au/Ag atomic ratio are presented. Finally, studies and prospects for optical and Raman tweezers experiments are discussed. [Copyright &y& Elsevier]

Abstract: We investigated the effects of cisplatin (cisPt) on matrix metalloproteinase-2 (MMP-2) gelatinolitic activity in transformed PC E1Araf rat thyroid cells. Cells incubated with increasing cisPt concentrations showed dose- and time-dependent decrease of the MMP-2 protein and activity. CisPt provoked the translocation from the cytosol to the plasma membrane of atypical protein kinase C-zeta (PKC-ζ) and the activation of PKB/AKT. The effect of cisPt on MMP-2 was dependent on PKC-ζ activation since it was potentiated by a myristoylated PKC-ζ pseudo substrate peptide or by PKC-ζ down-regulation by siRNA. Moreover, MMP-2 activity modulation by cisPt was also dependent on PKB/AKT activation since it was decreased by PKB/AKT down-regulation by siRNA or by pharmacological inhibition of PI3K, thus indicating the importance of the balance of PKB/AKT and PKC-ζ in regulating the cisPt effect on MMP-2 activity. The PC E1Araf cells displayed a migratory capacity that was blocked by MMP-2 down-regulation using siRNA or pharmacological inhibition. The inhibition of cell migration was also obtained with cisPt; in cisPt-treated cells the administration of MMP-2 active protein was able to restore cell migration capacity. In conclusion, the decrease of MMP-2 secretion after cisPt was allowed by PKB/AKT and counteracted by PKC-ζ; the cisPt-provoked inhibition of MMP-2 secretion ended in reduction of cell migration. [Copyright &y& Elsevier]

Abstract: Linear carbon chains (LCCs) contain sp hybridization either as alternating triple and single bonds (polyynes) or with consecutive double bonds (cumulenes). They are detected here in solution by a combined mass spectrometry (MS) and surface enhanced Raman scattering approach, and new insight into the carbon structures, formed after performing pulsed laser ablation of a polycrystalline graphite rod in water stabilized by the presence of metals is given. The possibility to establish a LCC–metal bond is also investigated by carrying out atmospheric pressure matrix assisted laser desorption ionization MS experiments on copper and silver polyynides. It was found that while the interaction of metal colloids with LCCs results mainly in a weak bond, polyynides appear as true organometallic compounds in which the metal is covalently bonded to the LCCs. [Copyright &y& Elsevier]

Abstract: Irradiation of carbon based solid targets with energetic particles is usually thought to introduce undesirable phenomena such as disorder or graphitization. In some recent experiments we observed that ion irradiation of simple hydrocarbons in the electronic excitation regime leads to the formation of sp-hybridized carbon nanowires with well definite lengths. This has been discussed in view of possible applications in materials science and in the astrophysical field. [Copyright &y& Elsevier]

Modelling the radionuclide cycle in forests is important in case of contamination due to acute or chronic releases to the atmosphere and from underground waste repositories. This article describes the most important aspects to consider in forest model development. It intends to give an overview of the modelling approaches available and to provide guidance on how to address the quantification of radionuclide transport in forests. Furthermore, the most important gaps in modelling the radionuclide cycle in forests are discussed and suggestions are presented to address the variability of forest sites. [ABSTRACT FROM AUTHOR]

The final disposal of NORM wastes in conventional landfill generally determines problems of acceptance by the landfill operators, since their willingness to accept Naturally Occurring Radioactive Material (NORM) is often limited due to their concern about the radiological risks and reluctance of the local community to have at local landfills material that despite being cleared is still perceived as 'radioactive'. In order to raise awareness among landfill operators, and also among other stakeholders on the actual radiological risk of exempted or cleared NORM wastes, it is of interest to estimate the mass of annual wastes containing NORM that can be disposed of in a landfill for conventional waste complying with the annual dose criterion of 1 mSv. A methodology was developed considering a hypothetical homogeneous large landfill and assuming that NORM wastes are delivered with an initial activity concentration of 1 kBq kg−1. The methodology uses exposure scenarios and assumptions from Radiation Protection 122 Part 2 , the codes RESRAD-ONSITE and OFFSITE, and the most recent dose coefficients from ICRP. The exposure scenarios considered are the "worker handling NORM at an active landfill" and "members of the public living near an active landfill", For these scenarios, screening levels (called Operational Levels in this work) in terms of activity concentration fulfilling the annual dose criterion of 1 mSv, for members of the public (including all ICRP age groups) and workers at a landfill, have been calculated for each decay chain segments using a generic and conservative approach. The Operational Levels evaluated in this work are almost independent from the landfill size and are relevant to the landfills complying the EU directive 1999/31 requirements. The obtained Operational Levels (OL) are all higher than 1 kBq kg−1, for U-238 and Th-232 series radionuclides and 10 Bq g−1 for K-40, which are the general clearance levels adopted in the European Union. The estimated OLs range between 2 kBq kg−1 (for Th-232sec) and about 150 kBq kg−1 (for Po-210). For the U-238 decay chain, the segments with the smallest OLs values are U-238sec (OL = 2.5 kBq kg−1) and Ra-226+ (OL = 3.7 kBq kg−1). For Th-232 chain, the most critical segments are Th-232sec and Th-228+ (OL = 3.8 kBq kg−1). As regards the mass of annual NORM wastes that can be disposed of in a conventional landfill, the levels obtained for Po-210, Pb-210+ and K-40 indicate that from the radiological point of view limitations to the annual admissible mass may occur only for large activity concentrations (i.e. 40 kBq kg−1 and above). For the other segments, instead, limitations can occur for activity concentration levels in residues above 2 kBq kg−1. • Landfill disposal of NORM wastes often faces acceptance issues from operators. • A method to estimate annual NORM waste for landfills complying 1 mSv y−1 dose criterion was developed. • Study results are relevant to landfills complying EU directive 1999/31 requirements. • Screening values are provided for practical use by non-expert authority/operators. [ABSTRACT FROM AUTHOR]

In the present work, we investigate some mechanical and electrical properties of a Chemical Vapor Deposition (CVD)-grown graphene layer transferred on 50 nm-thick Ge 2 Sb 2 Te 5 chalcogenide and discuss the possible application of graphene as a scaled contact replacing metal lines in phase-change memory devices. At first, the graphene-chalcogenide interface was extensively investigated. The expected chemical composition was confirmed by means of Electron Energy Loss Spectrometry (EELS), and the absence of bond distortions in the chalcogenide layer after graphene transfer was proved through Raman spectroscopy. The latter evidenced also the presence of defects, further confirmed by Transmission Electron Microscopy (TEM) investigations. The quality of the contact stack was evaluated by means of the adhesion among layers and by the sheet resistance of the layers themselves. Scratch tests and numerical simulations revealed a stress distribution compatible with a failure of the interface where the graphene layer features a 2 %-void. Next, the contact resistance proved an effective good Ohmic quality with a high graphene sheet resistance, about 1400 Ohm/square, which suggests that a better optimized transfer process should be applied to reduce it more than one order of magnitude. [ABSTRACT FROM AUTHOR]

Background: Tumor immune microenvironment (TME) plays a key role in malignant pleural mesothelioma (MPM) pathogenesis and treatment outcome, supporting a role of immune checkpoint inhibitors as anticancer approach. This study retrospectively investigated TME and programmed death ligand 1 (PD-L1) expression in naïve MPM cases and their change under chemotherapy. Patients and methods: Diagnostic biopsies of MPM patients were collected from four Italian and one Slovenian cancer centers. Pathological assessment of necrosis, inflammation, grading, and mitosis was carried out. Ki-67, PD-L1 expression, and tumor infiltrating lymphocytes were detected by immunohistochemistry. When available, the same paired sample after chemotherapy was analyzed. Pathological features and clinical characteristics were correlated to overall survival. Results: TME and PD-L1 expression were assessed in 93 and 65 chemonaive MPM samples, respectively. Twenty-eight samples have not sufficient tumor tissue for PD-L1 expression. Sarcomatoid/biphasic samples were characterized by higher CD8+ T lymphocytes and PD-L1 expression on tumor cells, while epithelioid showed higher peritumoral CD4+ T and CD20+ B lymphocytes. Higher CD8+ T lymphocytes, CD68+ macrophages, and PD-L1 expression were associated with pathological features of aggressiveness (necrosis, grading, Ki-67). MPM cases characterized by higher CD8+ T-infiltrate showed lower response to chemotherapy and worse survival at univariate analysis. Patients stratification according to a combined score including CD8+ T lymphocytes, necrosis, mitosis, and proliferation index showed median overall survival of 11.3 months compared with 16.4 months in cases with high versus low combined score (P<0.003). Subgroup exploratory analysis of 15 paired samples before and after chemotherapy showed a significant increase in cytotoxic T lymphocytes in MPM samples and PD-L1 expression in immune cells. Conclusions: TME enriched with cytotoxic T lymphocytes is associated with higher levels of macrophages and PD-L1 expression on tumor cells and with aggressive histopathological features, lower response to chemotherapy and shorter survival. The role of chemotherapy as a tumor immunogenicity inducer should be confirmed in a larger validation set. [ABSTRACT FROM AUTHOR]

In this work, we report X-ray photoelectron (XPS) and valence band (VB) spectroscopy measurements of surfactant-free silver nanoparticles and silver/linear carbon chains (Ag@LCC) structures prepared by pulse laser ablation (PLA) in water. Our measurements demonstrate significant oxidation only on the surfaces of the silver nanoparticles with many covalent carbon-silver bonds but only negligible traces of carbon-oxygen bonds. Theoretical modeling also provides evidence of the formation of robust carbon-silver bonds between linear carbon chains and pure and partially oxidized silver surfaces. A comparison of theoretical and experimental electronic structures also provides evidence of the presence of non-oxidized linear carbon chains on silver surfaces. To evaluate the chemical stability, we investigated the energetics of the physical adsorption of oxidative species (water and oxygen) and found that this adsorption is much preferrable on oxidized or pristine silver surfaces than the adsorption of linear carbon chains, which makes the initial step in the oxidation of LCC energetically unfavorable. [ABSTRACT FROM AUTHOR]

Pulsed laser with visible wavelength (532 nm) allows to modify the properties of graphene oxide (GO) sheets dispersed in water by finely tuning the amount of oxygen functionalities and, therefore, the degree of reduction. In this way both the hydrophilicity and the spectroscopic features of the GO suspension can be changed. This work reports the preparation of reduced graphene oxide (rGO) and mixed solutions of GO or rGO and Degussa P25 ® titania nanoparticles by pulsed laser irradiation. The produced materials are characterized by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Their ability to remove methylene blue from water is investigated by studying the dye decolorization. [ABSTRACT FROM AUTHOR]

Abstract: The nonlinear optical properties of linear carbon chains prepared by laser ablation in water were studied by using a nanosecond pulsed excitation. A strong optical limiting response was detected at laser fluences above 0.6J/. The nature of the nonlinear effect was investigated by the Z-scan technique, determining both the nonlinear absorption coefficient and the refraction one . A high second-order hyperpolarizability value of , essentially attributed to a dispersive effect, has been measured. Moreover, the good optical transparency in the visible region and a relatively good photo-stability make these carbon water colloids comparable with other carbon based materials and interesting for potential applications as optical limiter. [Copyright &y& Elsevier]

Abstract: Multi-wall carbon nanotubes (MWCNTs) containing linear C chains have been synthesised by arc discharge in liquid nitrogen. The experimental conditions used allow one to obtain nanotubes with a very thin innermost diameter, as evidenced by the radial breathing mode (RBM) features in the Raman spectra. A correlation between the RBM and the features of the C chains is reported, which gives a direct indication of how these linear carbon chain/carbon nanotube hybrid systems form. C chains are inserted only in CNTs having the innermost diameter equal to 0.7nm, as expected. [Copyright &y& Elsevier]