1,001 research outputs found

    Synthesis and Optimization of the Labeling Procedure of 99mTc-Hynic-Interleukin-2 for In vivo Imaging of Activated T lymphocytes

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    Introduction: We have previously described the labeling of interleukin-2 (IL2) with 123 I and 99m Tc-N3S. Both radiopharmaceuticals were successfully applied in humans to image several inflammatory lesions and autoimmune diseases characterized by tissue infiltrating lymphocytes expressing the IL2 receptor (CD25). However, both radiopharmaceuticals had some specific disadvantages, such as cost and time of synthesis

    Stringent Constraint on Galactic Positron Production

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    The intense 0.511 MeV gamma-ray line emission from the Galactic Center observed by INTEGRAL requires a large annihilation rate of nonrelativistic positrons. If these positrons are injected at even mildly relativistic energies, higher-energy gamma rays will also be produced. We calculate the gamma-ray spectrum due to inflight annihilation and compare to the observed diffuse Galactic gamma-ray data. Even in a simplified but conservative treatment, we find that the positron injection energies must be 3\lesssim 3 MeV, which strongly constrains models for Galactic positron production.Comment: 4 pages, 2 figures; minor revisions, accepted for publication in PR

    Molecular signals from primordial clouds at high redshift

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    The possibility to detect cosmological signals from the post-recombination Universe is one of the main aims of modern cosmology. In a previous paper we emphasized the role that elastic resonant scattering through LiH molecules can have in dumping primary CBR anisotropies and raising secondary signals. Here we extend our analysis to all the evolutionary stages of a primordial cloud, starting with the linear phase, through the turn-around and to the non linear collapse. We have done calculations for proto-clouds in a CDM scenario and, more generally, for a set of clouds with various masses and various turn-around redshifts, in this case without referring to any particular structure formation scenario. We found that the first phase of collapse, for t/tfreefall=0.05÷0.2t/t_{free-fall}=0.05\div 0.2 is the best one for simultaneous detection of the first two LiH rotational lines. The observational frequency falls between 30 and 250 GHz and the line width Δνν{\Delta \nu\over \nu} is between 10510^{-5} and 10410^{-4}. As far as we know this is the most favourable process to detect primordial clouds before they start star formation processes.Comment: 26 pages, uuencoded compressed postscript, 7 figures included. Accepted for publication in Ap.

    Gravitational waveforms from the evaporating ACO cosmic string loop

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    The linearly polarized gravitational waveforms from a certain type of rotating, evaporating cosmic string - the Allen-Casper-Ottewill loop - are constructed and plotted over the lifetime of the loop. The formulas for the waveforms are simple and exact, and describe waves which attenuate self-similarly, with the amplitude and period of the waves falling off linearly with time.Comment: 30 pages, 16 figure

    Biodiversity of vegetable crops, a living heritage

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    Biodiversity is the natural heritage of the planet and is one of the key factors of sustainable development, due to its importance not only for the environmental aspects of sustainability but also for the social and economic ones. The purpose of this Special Issue is to publish high-quality research papers addressing recent progress and perspectives while focusing on different aspects related to the biodiversity of vegetable crops. Original, high-quality contributions that have not yet been published, or that are not currently under review by other journals, have been gathered. A broad range of aspects such as genetic, crop production, environments, customs and traditions were covered. All contributions are of significant relevance and could stimulate further research in this area

    MeV Right-handed Neutrinos and Dark Matter

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    We consider the possibility of having a MeV right-handed neutrino as a dark matter constituent. The initial reason for this study was the 511 keV spectral line observed by the satellite experiment INTEGRAL: could it be due to an interaction between dark matter and baryons? Independently of this, we find a number of constraints on the assumed right-handed interactions. They arise in particular from the measurements by solar neutrino experiments. We come to the conclusion that such particles interactions are possible, and could reproduce the peculiar angular distribution, but not the rate of the INTEGRAL signal. However, we stress that solar neutrino experiments are susceptible to provide further constraints in the future.Comment: 7 pages, figure 1 changed, added reference

    Labelling and clinical performance of human leukocytes labelled with 99m Tc-HMPAO using leukokit® with gelofusine versus leukokit® with HES as sedimentation agent

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    The scintigraphy with radiolabelled autologous leukocytes (WBCs) is considered the gold-standard technique for imaging infections. Leukokit (R) is a commercially available, disposable, sterile kit for labelling WBCs ex vivo. In this kit, WBCs isolation from red blood cells (RBCs) was performed using poly(O-2-hydroxyethyl)starch (HES) as the RBCs sedimentation agent. Due to its poor availability, HES has been recently replaced by Gelofusine as the RBC sedimentation agent. The aim of this study was to compare the labelling efficiency and the diagnostic accuracy of WBCs labelled with Leukokit (R) with HES vs Leukokit (R) with Gelofusine. WBCs were isolated using HES or Gelofusine for 45minutes and then purified from platelets (PLTs) and labelled with 1.1 +/- 0.3 GBq of freshly prepared Tc-99m- HMPAO. The following parameters were evaluated: the number and type of recovered WBCs, RBCs contamination, PLTs contamination, vitality of neutrophils, and chemotactic properties of neutrophils. Clinical comparison was performed between 80 patients (33 males; age 67.5 +/- 14.2) injected with Tc-99m-HMPAO-WBCs, using HES as the sedimentation agent, and 92 patients (38 males; age 68.2 +/- 12.8) injected with Tc-99m-HMPAO-WBCs using Gelofusine as the sedimentation agent. Patients were affected by prosthetic joint infections, peripheral bone osteomyelitis, or vascular graft infection. We compared radiolabelling efficiency (LE), final recovery yield (RY), and diagnostic outcome based on microbiology or 2-year follow-up. Results showed that HES provides the lowest RBCs and PLTs contamination, but Gelofusine provides the highest WBC recovery. Both agents did not influence the chemotactic properties of WBCs, and no differences were found in terms of LE and RY. Sensitivity, specificity, and accuracy were also not significantly different for WBCs labelled with both agents (diagnostic accuracy 90.9%, CI = 74.9-96.1 vs 98.3%, CI = 90.8-100, for HES and Gelofusine, respectively). In conclusion, Gelofusine can be considered a suitable alternative of HES for WBCs separation and labelling

    Retrieval of magnetic medical microrobots from the bloodstream

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    Untethered magnetic microrobots hold the potential to penetrate hard-to-reach areas of the human body and to perform therapy in a controlled way. In the past decade, impressive advancements have been made in this field but the clinical adoption of magnetoresponsive microrobots is still hampered by safety issues. A tool appointed for magnetic microrobots retrieval within body fluids could enable a real paradigm change, fostering their clinical translation.By starting from the general problem to retrieve magnetic microrobots injected into the bloodstream, the authors introduce a magnetic capture model that allows to design retrieval tools for magnetic cores of different diameters (down to 10 nm) and in different environmental conditions (fluid speed up to 7 cms-1). The model robustness is demonstrated by the design and testing of a retrieval catheter. In its optimal configuration, the catheter includes 27 magnets and fits a 12 F catheter. The model provides a good prediction of capture efficiency for 250 nm magnetic particles (experimental data: 77.6%, model prediction: 65%) and a very good prediction for 500 nm particles (experimental data: 93.6%, model prediction: 94%). The results support the proposed model-based design approach, which can be extended to retrieve other magnetoresponsive agents from body compartments

    What a difference a workplace makes. A scientometric analysis on the relationship between job crafting and healthy organizations' factors

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    Introduction: The transformations that have affected the labour market in recent years have required companies to adapt to fast changes and to keep the pace of global competition. Consequently, workers have been confronted with multiple challenging demands: they have been required to develop flexibility in their jobs and to work faster and better, often with evident costs in terms of performance and their workplace well-being. Given these evidence, as also shown by some of the most recent developments in the field of Positive Work and Organizational Psychology, healthy organizations are those organizations that could resist to these challenges, because they engage in creating an environment that can promote employees’ health and safety, maximising performance. Yet, healthy organizations support positive organizational behaviors through a coherent culture, a positive climate, and good practices. Healthy organizations might also create the conditions to encourage workers to perform job crafting behaviors, meant as proactive individual behaviours aimed at modifying job demands in order to adjust them to personal needs, motivations and talents, thus maximising well-being and performance. Objective: The aim of the study was to overview the state of the art of the debate about the relationship between job crafting and healthy organizations’ factors by performing a scientometric analysis of job crafting. Therefore, the study was aimed to emphasize performances of countries, journals and authors, highlighting the dominant perspectives on the topic. Method: The starting point of the analysis was data recovery from the Scopus database using the term “job crafting” as search criterion within the title, abstract or keywords of the documents retrieved. The analysis was carried out with two softwares, R and VOSviewer, in order to investigate the growth of interest on the topic over the years, the scientific production of countries, journals and authors, the social structure of collaborative network, and the network of keywords. Results: 375 documents about job crafting were retrieved, showing a growing number of publications in recent years, with a preponderance of productions and citations in USA and Netherlands (where the construct was proposed and validated). Cluster analysis performed on the most frequently used keywords showed three main groups, each of them theoretical linked to workplace health: stimulus factors; Job Demands-Resources Model; health dimensions. Discussion: The present bibliometric analysis showed an increasing scientific interest toward job crafting and the importance of specific papers (that opened the two main perspective about it) for the whole research line. Through the cluster analysis of keywords network, it was underlined the relevance of constructs that promote healthy organizations in the scientific production on job craftin
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