Electron Emission from Foils and Biological Materials after Proton Impact

Electron emission spectra from thin metal foils with thin layers of water frozen on them (amorphous solid water) after fast proton impact have been measured and have been simulated in liquid water using the event-by-event track structure code PARTRAC. The electron transport model of PARTRAC has been extended to simulate electron transport down to 1 eV by including low-energy phonon, vibrational and electronic excitations as measured by Michaud et al. (Radiat. Res. 159, 3–22, 2003) for amorphous ice. Simulated liquid water yields follow in general the amorphous solid water measurements at higher energies, but overestimate them significantly at energies below 50 eV. Originally published Radiation Physics and Chemistry, Vol. 77, No. 10-12, Oct-Dec 200

«Ανάκληση δωρεάς»

Αντικείμενο της παρούσας μελέτης είναι η ανάκληση της δωρεάς, η οποία προβλέπεται στο άρθρο 505 του Αστικού Κώδικα. Αρχικά, στο πρώτο κεφάλαιο θα εξεταστεί η σύμβαση της δωρεάς ως ενοχική δικαιοπραξία στο σύνολό της όπως αυτή παρουσιάζεται στα άρθρα 496 έως 504, προκειμένου στη συνέχεια να γίνει ομαλή μετάβαση και εμβάθυνση στο βασικό θέμα. Ειδικότερα, θα επικεντρωθώ στην έννοια της δωρεάς, στη νομική της φύση και στις μορφές υπό τις οποίες αυτή εμφανίζεται. Ακόμη, θα προχωρήσω σε μία διάκριση της εν λόγω σύμβασης από άλλες συγγενείς της συμβάσεις, θα αναφερθώ στα ουσιώδη στοιχεία της σύμβασης δωρεάς αλλά και στην ευθύνη του δωρητή. Στο δεύτερο κεφάλαιο θα αναλύσω το κύριο θέμα της παρούσας διπλωματικής εργασίας, ήτοι την ανάκληση της δωρεάς. Πιο συγκεκριμένα, θα μελετήσουμε σε βάθος τους λόγους ανάκλησης της δωρεάς με βασικό γνώμονά μας τη νομολογία. Ιδιαίτερη βαρύτητα θα δοθεί στον νομοθετικά αναγνωρισμένο λόγο της αχαριστίας, για τον οποίο υπάρχει πλούσιο νομολογιακό υλικό και αποτελεί μια μορφή τιμωρίας του αχάριστου δωρεοδόχου. Επιπροσθέτως, στο τρίτο κεφάλαιο θα αναφερθώ εκτενώς στην άσκηση του δικαιώματος ανάκλησης καθώς και στην απόσβεσή του, ενώ στο τέταρτο κεφάλαιο θα προβώ σε μία σύγκριση των λοιπών μονομερών λύσεων μιας σύμβασης με την ανάκληση της δωρεάς καταλήγοντας στο συμπέρασμα ότι η ρύθμιση περισσότερων τρόπων μονομερούς λύσης μιας σύμβασης δεν πρόκειται για τυχαία νομοθετική επιλογή. Τέλος, στο πέμπτο και τελευταίο κεφάλαιο, θα αναφερθώ στις ιδιαίτερες μορφές δωρεάς και ιδίως στη δωρεά υπό τρόπο, στη δωρεά υπό ιδιαίτερο ηθικό καθήκον και από λόγους ευπρέπειας, στη μικτή δωρεά, στη δωρεά περιοδικών παροχών, στη δωρεά αιτία θανάτου και στη δωρεά υπέρ τρίτου σε περίπτωση θανάτου, καθώς και στην ανάκλησή τους.The object of the present study is the revocation of the donation, which is provided in article 505 of the Civil Code. Initially, the first chapter will examine the donation contract as a debt legal act in its entirety as presented in Articles 496 to 504, in order to then make a smooth transition and deepen the main issue. In particular, I will focus on the concept of donation, its legal nature and the forms in which it occurs. Furthermore, I will proceed to a distinction of this contract from other related contracts, I will refer to the essential elements of the donation contract but also to the responsibility of the donor. In the second chapter I will analyze the main topic of this dissertation, namely the revocation of the donation. More specifically, we will study in depth the reasons for the withdrawal of the donation based on jurisprudence. Particular emphasis will be given to the legally recognized word of ingratitude, for which there is rich case law and is a form of punishment of the ungrateful recipient. In addition, in the third chapter I will refer extensively to the exercise of the right of revocation as well as its amortization, while in the fourth chapter I will make a comparison of the other unilateral solutions of a contract with the revocation of the donation concluding that the regulation of more unilateral solutions contract is not a random legislative choice. Finally, in the fifth and last chapter, I will refer to the special forms of donation and in particular to donation in a manner, to donation under special moral duty and for reasons of decency, to mixed donation, to the donation of periodic benefits, to the donation of cause of death and to donation to a third party in case of death, as well as in their revocation

Ορισμός και αντικατάσταση δικαστικού συμπαραστάτη και μελών εποπτικού συμβουλίου

Αντικείμενο της παρούσας μελέτης είναι ο ορισμός και η αντικατάσταση του δικαστικού συμπαραστάτη και των μελών του εποπτικού συμβουλίου, ζητήματα τα οποία προβλέπονται στα άρθρα 1666 επ. του Αστικού Κώδικα. Αρχικά, στο πρώτο κεφάλαιο θα εξεταστεί η δικαστική συμπαράσταση ως θεσμός στο σύνολό του όπως αυτός παρουσιάζεται στα άρθρα 1666 ΑΚ επ., προκειμένου στη συνέχεια να γίνει ομαλή μετάβαση και εμβάθυνση στο βασικό θέμα. Ειδικότερα, θα επικεντρωθώ στον ορισμό και στη ρύθμιση του θεσμού της δικαστικής συμπαράστασης εν γένει, στα πρόσωπα που υποβάλλονται στο εν λόγω καθεστώς καθώς και στα πρόσωπα που νομιμοποιούνται ενεργητικά για τη κίνηση της διαδικασίας αυτής. Ακόμη, θα προχωρήσω σε παράθεση των αποτελεσμάτων θέσης του πάσχοντος στο θεσμό της δικαστικής συμπαράστασης, θα αναφερθώ στην άρση του καθεστώτος αλλά και στη μεταβολή αυτού. Στο δεύτερο και βασικότερο κεφάλαιο της παρούσας, θα αναλύσω το κύριο θέμα της διπλωματικής εργασίας, ήτοι το πρόσωπο του δικαστικού συμπαραστάτη. Πιο συγκεκριμένα, θα μελετήσουμε την διαδικασία διορισμού του προσώπου του δικαστικού συμπαραστάτη καθώς και την αντικατάστασή του. Επίσης, ιδιαίτερη βαρύτητα θα δοθεί στις αρμοδιότητές του αλλά και στα κριτήρια επιλογής του με αναφορές σε νομολογιακό υλικό. Επιπροσθέτως, στο κεφάλαιο αυτό θα αναφερθώ εκτενώς στα κωλύματα διορισμού ενός προσώπου ως δικαστικού συμπαραστάτη αλλά και στην αδυναμία εξεύρεσης του κατάλληλου προσώπου. Εν συνεχεία, στο τρίτο κεφάλαιο θα αναφερθώ στον προσωρινό δικαστικό συμπαραστάτη – ήτοι στα είδη και τις εξουσίες αυτού, στη λήξη της προσωρινής δικαστικής συμπαράστασης και τέλος στον ειδικό δικαστικό συμπαραστάτη. Τέλος, στο τέταρτο και τελευταίο κεφάλαιο της παρούσας θα ασχοληθώ με το εποπτικό συμβούλιο, ήτοι με το έργο του, τη διαδικασία διορισμού του, την εν γένει λειτουργία και θητεία των μελών του.The object of this study is the definition and replacement of the judicial assistant and the members of the supervisory board, issues which are provided in articles 1666 et seq. Of the Civil Code. Initially, in the first chapter, the judicial support will be examined as an institution as a whole as it is presented in articles 1666 of the Civil Code, in order to then make a smooth transition and deepening to the main issue. In particular, I will focus on the definition and regulation of the institution of judicial assistance in general, on the persons subject to this scheme as well as on the persons who have legal legitimacy to initiate this procedure. I will also list the results of the patient's position in the institution of legal aid, I will refer to the lifting of the regime but also to its change. In the second and most important chapter of this, I will analyze the main topic of the dissertation, namely the person of the legal assistant. More specifically, we will study the process of appointing the person of the legal assistant as well as his replacement. Also, special emphasis will be given to his responsibilities but also to his selection criteria with references to case law material. In addition, in this chapter I will refer at length to the obstacles to appointing a person as a legal assistant but also to the inability to find the right person. Next, in the third chapter, I will refer to the temporary legal aid - that is, its types and powers, the end of the temporary legal aid and finally to the special legal aid. Finally, in the fourth and last chapter of the present I will deal with the supervisory board, ie with its work, its appointment process, the general operation and term of office of its members

«Το Δίκαιο της προπτωχευτικής διαδικασίας εξυγίανσης»

Σε περιόδους οικονομικής κρίσης το πτωχευτικό δίκαιο έρχεται στο προσκήνιο ως ο δικαιϊκός εκείνος κλάδος, ο οποίος ενδεχομένως θα μπορούσε να ασχοληθεί με το κρίσιμο ερώτημα σχετικά με το τι μπορεί αλλά και πρέπει να γίνει με τις αφερέγγυες επιχειρήσεις και τα εμπλεκόμενα σε αυτές πρόσωπα. Όπως είναι ευνόητο, απάντηση στο εν λόγω ερώτημα θα μπορούσε να δώσει το κομμάτι του πτωχευτικού δικαίου που σχετίζεται με την εξυγίανση των επιχειρήσεων, παρέχοντας το κατάλληλο ρυθμιστικό πλαίσιο με τη βοήθεια του οποίου οι αφερέγγυες εταιρίες θα αποκτήσουν τη δυνατότητα διατήρησης, ανόρθωσης και αναδιάρθρωσης.In times of financial crisis, bankruptcy law comes to the fore as that fair sector, which might be able to deal with the crucial question of what can and should be done with insolvent businesses and the persons involved. It is understandable that the answer to this question could give the piece of bankruptcy law relating to business reorganization by providing the appropriate regulatory framework by means of which insolvent companies will be able to maintain, recover and restructure

Penetration and intracellular uptake of poly(glycerol-adipate)nanoparticles into 3-dimensional brain tumour cell culture models

Nanoparticle (NP) drug delivery systems may potentially enhance the efficacy of therapeutic agents. It is difficult to characterise many important properties of NPs in vivo and therefore attempts have been made to use realistic in vitro multicellular spheroids instead. In this paper we have evaluated poly(glycerol-adipate) (PGA) NPs as a potential drug carrier for local brain cancer therapy. Various 3-dimensional (3-D) cell culture models have been used to investigate the delivery properties of PGA NPs. Tumour cells in 3-D culture showed a much higher level of endocytic uptake of NPs than a mixed normal neonatal brain cell population. Differences in endocytic uptake of NPs in 2-D and 3-D models strongly suggest that it is very important to use in vitro 3-D cell culture models for evaluating this parameter. Tumour penetration of NPs is another important parameter which could be studied in 3-D cell models. The penetration of PGA NPs through 3-D cell culture varied between models, which will therefore require further study to develop useful and realistic in vitro models. Further use of 3-D cell culture models will be of benefit in the future development of new drug delivery systems, particularly for brain cancers which are more difficult to study in vivo

Microdosimetry of electrons in liquid water using the low-energy models of Geant4

The biological effects of ionizing radiation at the cellular level are frequently studied using the well-known formalism of microdosimetry, which provides a quantitative description of the stochastic aspects of energy deposition in irradiated media. Energy deposition can be simulated using Monte Carlo codes, some adopting a computationally efficient condensed-history approach, while others follow a more detailed track-structure approach. In this work, we present the simulation of microdosimetry spectra and related quantities (frequency-mean and dose-mean lineal energies) for incident monoenergetic electrons (50 eV-10 keV) in spheres of liquid water with dimensions comparable to the size of biological targets: base pairs (2 nm diameter), nucleosomes (10 nm), chromatin fibres (30 nm) and chromosomes (300 nm). Simulations are performed using the condensed-history low-energy physics models ( Livermore and Penelope ) and the track-structure Geant4-DNA physics models, available in the Geant4 Monte Carlo simulation toolkit. The spectra are compared and the influence of simulation parameters and different physics models, with emphasis on recent developments, is discussed, underlining the suitability of Geant4-DNA models for microdosimetry simulations. It is further shown that with an appropriate choice of simulation parameters, condensed-history transport may yield reasonable results for sphere sizes as small as a few tens of a nanometer

An implementation of discrete electron transport models for gold in the Geant4 simulation toolkit

Gold nanoparticle (GNP) boosted radiation therapy can enhance the biological effectiveness of radiation treatments by increasing the quantity of direct and indirect radiation-induced cellular damage. As the physical effects of GNP boosted radiotherapy occur across energy scales that descend down to 10 eV, Monte Carlo simulations require discrete physics models down to these very low energies in order to avoid underestimating the absorbed dose and secondary particle generation. Discrete physics models for electron transportation down to 10 eV have been implemented within the Geant4-DNA low energy extension of Geant4. Such models allow the investigation of GNP effects at the nanoscale. At low energies, the new models have better agreement with experimental data on the backscattering coefficient, and they show similar performance for transmission coefficient data as the Livermore and Penelope models already implemented in Geant4. These new models are applicable in simulations focussed towards estimating the relative biological effectiveness of radiation in GNP boosted radiotherapy applications with photon and electron radiation sources

Cosmic-Ray Tracks in Astrophysical Ices: Modeling with the Geant4-DNA Monte Carlo Toolkit

Cosmic rays are ubiquitous in interstellar environments, and their bombardment of dust-grain ice mantles is a possible driver for the formation of complex, even prebiotic molecules. Yet, critical data that are essential for accurate modeling of this phenomenon, such as the average radii of cosmic-ray tracks in amorphous solid water (ASW) remain unconstrained. It is shown that cosmic-ray tracks in ASW can be approximated as a cylindrical volume with an average radius that is mostly independent of the initial particle energy. Interactions between energetic ions and both low-density amorphous (LDA) and high-density amorphous (HDA) ice targets are simulated using the Geant4-DNA Monte Carlo toolkit, which allows for tracking secondary electrons down to subexcitation energies in the material. We find the peak track-core radii, r cyl, for LDA and HDA ices to be 9.9 nm and 8.4 nm, respectively-somewhat less than double the value of 5 nm often assumed in astrochemical models. © 2020. The American Astronomical Society. All rights reserved

Acute changes in myocardial tissue characteristics during hospitalization in patients with COVID-19

Background: Patients with a history of COVID-19 infection are reported to have cardiac abnormalities on cardiovascular magnetic resonance (CMR) during convalescence. However, it is unclear whether these abnormalities were present during the acute COVID-19 illness and how they may evolve over time. Methods: We prospectively recruited unvaccinated patients hospitalized with acute COVID-19 (n = 23), and compared them with matched outpatient controls without COVID-19 (n = 19) between May 2020 and May 2021. Only those without a past history of cardiac disease were recruited. We performed in-hospital CMR at a median of 3 days (IQR 1–7 days) after admission, and assessed cardiac function, edema and necrosis/fibrosis, using left and right ventricular ejection fraction (LVEF, RVEF), T1-mapping, T2 signal intensity ratio (T2SI), late gadolinium enhancement (LGE) and extracellular volume (ECV). Acute COVID-19 patients were invited for follow-up CMR and blood tests at 6 months. Results: The two cohorts were well matched in baseline clinical characteristics. Both had normal LVEF (62 ± 7 vs. 65 ± 6%), RVEF (60 ± 6 vs. 58 ± 6%), ECV (31 ± 3 vs. 31 ± 4%), and similar frequency of LGE abnormalities (16 vs. 14%; all p > 0.05). However, measures of acute myocardial edema (T1 and T2SI) were significantly higher in patients with acute COVID-19 when compared to controls (T1 = 1,217 ± 41 ms vs. 1,183 ± 22 ms; p = 0.002; T2SI = 1.48 ± 0.36 vs. 1.13 ± 0.09; p  Conclusion: Unvaccinated patients hospitalized for acute COVID-19 demonstrated CMR imaging evidence of acute myocardial edema, which normalized at 6 months, while biventricular function and scar burden were similar when compared to controls. Acute COVID-19 appears to induce acute myocardial edema in some patients, which resolves in convalescence, without significant impact on biventricular structure and function in the acute and short-term. Further studies with larger numbers are needed to confirm these findings