34 research outputs found
Attitudes and thoughts of medical practitioners towards their profession in the era of financial crisis in Greece
Introduction: The ongoing financial crisis occurring in Greece the last 8 years has affected the income of citizens in the country, their quality of life, as well as social and occupational relationships. Aim of this study assess attitudes towards working conditions and personal life and to explore quality of life, positive or negative attitudes, as well as disorders in sleep, mood, physical condition among doctors working or being trained in a tertiary hospital of NE Greece
Methods: Included were 133 medical students and doctors of all ranks (61.7% males) practicing medicine in a University Tertiary Hospital in Greece. All of them answered a 31-item questionnaire regarding their working conditions, daytime activities and personal life, sleeping habits.
Results: In general, the majority reported dissatisfaction with the work environment, the salary and they rated their quality of life worse than that of the general population. Weekly workload exceeded 60 hours for the majority. No difference between sexes was revealed, with the exception of use of energy drinks which was more prevalent in males (70.7% vs. 51%, p=0.022). Comparison between ranks revealed that medical students performed better in everyday activities and socialization, although prevalence of reported fatigue was higher in them. Finally, it was demonstrated that surgeons used more frequently medication to achieve sleep promotion (80.4% vs. 36%, p<0.001) and daily energy (78.4% vs. 44%, p<0.001).
Conclusions: An overall dissatisfaction regarding workload, salary and quality of life is recorded among doctors of a tertiary hospital in Greece, with different coping strategies among subgroups.
 
Common Adverse Effects of Anti-TNF Agents on Gestation
Autoimmune disease has affected up to 50 million Americans, according to the American Autoimmune Related Diseases Association (AARDA) and 75 percent of those affected are women. These inflammatory diseases have variable activity and a lot of women will have to undergo major therapies during and after pregnancy. Many of the women suffering from these disease will improve during gestation. However a lot of women will require continuation of disease-modifying therapies (i.e., biological therapies) throughout pregnancy and post-partum involving many risks. In the past decade all gaze turned to biological therapies, as an attempt, to obtain even more effective medications in order to suppress the exacerbation of autoimmune disease, even at the most unfit circumstances such as pregnancy. The results are both satisfying and promising since increasingly proven thoughts prevail on making anti-TNF agents first-line medications, clearing up the limited knowledge over human influence. The purpose of this review is to summarize the results of the reports with the highest and representative range of patients of the last decade involving the use of anti-TNF agents during pregnancy
Ovarian Cancer and Glutamine Metabolism
Cancer cells are known to have a distinct metabolic profile and to exhibit significant changes in a variety of metabolic mechanisms compared to normal cells, particularly glycolysis and glutaminolysis, in order to cover their increased energy requirements. There is mounting evidence that there is a link between glutamine metabolism and the proliferation of cancer cells, demonstrating that glutamine metabolism is a vital mechanism for all cellular processes, including the development of cancer. Detailed knowledge regarding its degree of engagement in numerous biological processes across distinct cancer types is still lacking, despite the fact that such knowledge is necessary for comprehending the differentiating characteristics of many forms of cancer. This review aims to examine data on glutamine metabolism and ovarian cancer and identify possible therapeutic targets for ovarian cancer treatment
Investigation on the behaviour of members from cold-formed angle sections used for lattice towers
The role of DLL-4 (Delta Like Ligand 4) gene in endometrial cancer
The Notch signaling pathway controls normal embryonic development and tissue homeostasis of many cell types. It regulates cell proliferation, fate, differentiation, and cell death, by short-range signaling between nearby cells that come in contact. The Notch pathway has also been critically involved in the pathobiology of a variety of malignancies, regulating cancer initiation and development, as well as early stages of cancer progression, by adjusting conserved cellular programs and angiogenesis. Delta-like ligand 4 (DLL4), one of the five Notch signaling ligands in mammals, has an important function in the overall progression of malignancies. Especially, sequencing Notch gene mutations, including those of DLL4, have been identified in a number of human tumors, including breast, ovarian and cervical cancer, revealing information on the progression of specific gynecological tumor types and the essential role of DLL4 in gynecological cancer development. Τhis thesis investigates the implication of DLL4 in the development of endometrial cancer. We examined the expression of DLL4 in blood and endometrial tissues of 33 women diagnosed with endometrial cancer. The results of this study revealed a significant decrease in the expression of DLL4 of the vessels in the inner regions of the tumor. We suggest that DLL4 expression is reduced in adverse metabolic (hypoxic and acidic) conditions inside the tumor, thus impairing the ability of tumor vessels to survive in the central areas of the tumor. The involvement of other signaling pathways in the development of this cancer is possible and requires further investigation.Η οδός σηματοδότησης Notch ελέγχει την κανονική εμβρυϊκή ανάπτυξη και την ομοιόσταση των ιστών πολλών τύπων κυττάρων. Ρυθμίζει τον πολλαπλασιασμό, τη διαφοροποίηση και τον κυτταρικό θάνατο, μέσω σηματοδότησης μικρής εμβέλειας μεταξύ γειτονικών κυττάρων που έρχονται σε επαφή. Το μονοπάτι Notch έχει επίσης εμπλακεί κομβικά στην παθοβιολογία μιας ποικιλίας κακοηθειών, που ρυθμίζει την έναρξη την ανάπτυξη, καθώς και τα πρώτα στάδια της εξέλιξης του καρκίνου, προσαρμόζοντας τα κυτταρικά προγράμματα και την αγγειογένεση. Ο Delta-like ligand 4 (DLL4), ένας από τους πέντε συνδέτες σηματοδότησης του συστήματος Notch στα θηλαστικά, έχει σημαντική λειτουργία στη συνολική εξέλιξη του καρκίνου. Συγκεκριμένα, οι αλληλουχίες των γονιδιακών μεταλλάξεων του Notch και ειδικά αυτή του DLL4 έχουν εντοπιστεί σε αρκετούς όγκους, συμπεριλαμβανομένου του καρκίνου του μαστού, των ωοθηκών και του τραχήλου της μήτρας, αποκαλύπτοντας πληροφορίες σχετικά με την εξέλιξη των συγκεκριμένων τύπων καρκίνου καθώς και τον ουσιαστικό ρόλο του DLL4 στην ανάπτυξη του γυναικολογικού καρκίνου. Η παρούσα διατριβή ερευνά τον ρόλο του DLL4 στην εξέλιξη του καρκίνου του ενδομητρίου. Εξετάσαμε την έκφραση του DLL4 στο αίμα και στους ενδομητρικούς ιστούς 33 γυναικών που διαγνώστηκαν με καρκίνο του ενδομητρίου. Τα αποτελέσματα απέδειξαν ότι η έκφρασης του DLL4 στα αγγεία μειώθηκε στις εσώτερες περιοχές του όγκου. Προτείνουμε ότι η έκφραση DLL4 μειώνεται στις δυσμενείς μεταβολικά (υποξικές και όξινες) συνθήκες του εσωτερικού του όγκου, διαταράσσοντας έτσι την ικανότητα επιβίωση των αγγείων του όγκου στις κεντρικές περιοχές του όγκου. Η εμπλοκή άλλων σηματοδοτικών μονοπατιών στην ανάπτυξη αυτού του καρκίνου είναι ενδεχόμενη και απαιτείται περαιτέρω διερεύνηση
Wind-Induced Failure Analysis and Retrofit of an Existing Steel Structure
peer reviewedThe “Dimitrios Vikelas” athletic center in Ermoupolis of Syros, Greece, consists
of two buildings. Building B has a steel superstructure that was constructed
approximately 35 years ago. It was initially used as a boat shelter and
no design calculations were made. It contains steel columns with varying cross
section heights. The spans are bridged via trusses and I-beams. Significant
geometrical inconsistencies are noted among the existing steel connections
and failures have been recorded as a result of buckling in several beams and
bracings during the service life of the athletic center. The current study
presents an investigation performed in order to diagnose building structural
problems and propose strengthening and intervention measures. The goal of
this study was to improve the load-carrying capacity of the structure in order
to comply with the current design codes. Moreover, enhancement of the dynamic
properties of the strengthened structure was demonstrated using modal
analyses. The structural behavior was determined in a more precise manner
via non-linear wind time-history and incremental static analyses. The analytical
results explain the development of failures in the existing structure
Non linear postbuckling analysis of frames with varying cross sections
129 σ.Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Δομοστατικός Σχεδιασμός και Ανάλυση των Κατασκευών”Η παρούσα εργασία εξετάζει προβλήματα μη γραμμικής συμπεριφοράς επίπεδων πλαισιακών φορέων από χάλυβα με βάση τη θεωρία της ελαστικής ευστάθειας. Η φέρουσα συμπεριφορά των κατασκευών έναντι ευστάθειας επισημαίνεται στη διεθνή βιβλιογραφία ως μείζονος σημασίας. Επιπλέον, όταν εισάγονται κατασκευαστικές διατάξεις ή ατέλειες το πρόβλημα γίνεται περισσότερο απαιτητικό και συνάμα αρκετά ενδιαφέρον. Στόχος της εργασίας είναι να εμβαθύνει στα φαινόμενα μη γραμμικής συμπεριφοράς ατελών φορέων με μέλη μεταβλητής δυσκαμψίας.
Στο πρώτο κεφάλαιο παρουσιάζεται ο κυβικός νόμος μεταβολής της ροπής αδρανείας διατομών διπλού ταυ και η επίλυση της διαφορικής εξίσωσης μέλους υπό θλίψη με τις συναρτήσεις Bessel. Έπειτα, εξάγονται οι αναλυτικές σχέσεις σύμφωνα με τη γραμμική θεωρία ελαστικής ευστάθειας για διάφορες περιπτώσεις λυγισμού πλαισίων με ή χωρίς μετάθεση και τα αποτελέσματα συνοψίζονται στα αντίστοιχα διαγράμματα κρίσιμων φορτίων καθώς και μηκών λυγισμού.
Στο δεύτερο κεφάλαιο, αφού γίνει αναφορά στην ενεργειακή μέθοδο, αναπτύσσεται η θεωρία μετρίως μεγάλων μετατοπίσεων και εξάγονται οι σχέσεις που περιγράφουν τη μη γραμμική συμπεριφορά του πλαισιακού φορέα έναντι καμπτικού λυγισμού. Εν συνεχεία, επισυνάπτονται παραμετρικές συγκρίσεις μεταξύ των δρόμων ισορροπίας, οι οποίοι εξήχθησαν μέσω αλγορίθμων στη γλώσσα προγραμματισμού Fortran, ενώ γίνεται και η σύγκριση με τις αντίστοιχες γραμμικές λύσεις. Τέλος, διερευνάται η επιρροή αρχικών ατελειών και συγκεκριμένα της έκκεντρης φόρτισης στη φέρουσα ικανότητα του πλαισίου, απ’ όπου λαμβάνονται ενδιαφέροντα συμπεράσματα που αφορούν συστήματα που χάνουν την ευστάθειά τους μέσω σημείου διακλάδωσης.
Στο τρίτο κεφάλαιο βελτιώνεται η προσομοίωση του μοντέλου με την εισαγωγή ενός στροφικού και έπειτα ενός μετακινησιακού ελατηρίου. Με τον τρόπο αυτό δύναται να μελετηθεί φορέας με ακριβής συνοριακές συνθήκες ώστε να προσεγγίζεται η πραγματική φέρουσα ικανότητα ενός πλαισίου μιας κατασκευής. Ακόμα, επισημαίνονται οι δυσκολίες της επίλυσης του προβλήματος, οπότε προτείνεται μία απλοποιητική προσέγγιση που, όμως, δεν πρέπει να εισάγει σημαντικά σφάλματα.
Στο τελευταίο κεφάλαιο ερευνάται η αξιοπιστία της ενεργειακής μεθόδου καθώς και του κυβικού νόμου μεταβολής της δυσκαμψίας μέσω λογισμικών πεπερασμένων στοιχείων (Sap2000 και Adina) με γραμμικές και μη γραμμικές αναλύσεις. Περιγράφονται οι τρόποι προσομοίωσης των φορέων και ακολουθούν οι συγκρίσεις για ένα ευρύ φάσμα διάφορων παραμέτρων. Τα αποτελέσματα επισυνάπτονται σε συγκριτικούς πίνακες και διαγράμματα δρόμων ισορροπίας των μη γραμμικών αναλύσεων, όπου γίνεται εμφανέστερη η πραγματική συμπεριφορά της κατασκευής.The present thesis examines problems related to the non-linear behaviour of plane steel frames according to the theory of elastic stability. In the literature the load behaviour of structures against stability is noted as major importance. Furthermore, when construction provisions or defects are imported the problem becomes more challenging and also more interesting. The aim of this thesis is to deepen the effects of non-linear behavior of imperfect frames with members of variable stiffness.
The first chapter presents the cubic law variation of the moment of inertia of double tee sections and the solution of the differential equation of a member under compression with Bessel functions. Then the analytical relations are exported according to the linear theory of elastic stability for various buckling cases of frames with or without transfer. The results are summarized in the respectively diagrams of critical loads and effective buckling lengths.
In the second chapter, after a reference to the energy method, the theory of moderately large displacements is developed and the relations describing the nonlinear behaviour of the frame under flexural buckling are exported. Subsequently, parametric comparisons between the entire (prebuckling and postbuckling) equilibrium paths are attached. Those were exported via algorithms in Fortran programming language. Also, the comparison with the corresponding linear solutions were made. Finally, the influence of initial imperfections, specifically the loading eccentricity, is investigated about the frames load behaviour. There we obtain interesting results concerning systems which lose their stability through a bifurcational point.
In the third chapter we improve the simulation of the model by introducing a torsional and then a translational spring. In this way frames with accurate boundary conditions may be considered so that the actual load carrying capacity of a plane-frame -which is included in a structure- can be approximated. Furthermore, the difficulties of solving this problem are highlighting, so a simplified approach is proposed, which, however, should not introduce significant errors.
The last chapter presents the investigation about the reliability of both the energy method and the cubic law of stiffness variation, through finite element software (Sap2000 and Adina) with linear and nonlinear analysis. Herein the simulation of the plane-frames is described, and the comparisons are following with a wide range of various parameters. The comparative results are attached in both tabular and graphical form. Especially, from the non-linear equilibrium paths becomes apparent the actual behaviour of the construction.Ζαχαρίας Χ. Φασουλάκη
Preservative Monitoring of a Greek Woman with Hydrops Fetalis due to Parvovirus B19 Infection
Primate erythroparvovirus 1 (parvovirus B19) is a member of the Erythrovirus genus of the Parvoviridae family and it is one of the few members of the family known to be pathogenic in human. B19 infection is common and widespread with the virus being associated with numerous rheumatologic and haematologic manifestations. More specifically, maternal infection with parvovirus B19 during pregnancy can cause severe anemia which may lead to nonimmune hydrops or fetal demise, as a result of fetal erythroid progenitor cells infection with shortened half-life of erythrocytes. We present a rare case reported in the Greek population, of subclinical transient reticulocytopenia due to B19 parvovirus infection, in an asymptomatic pregnant woman, without medical history of hemoglobinopathy, and with the presence of hydrops fetalis during the third trimester of her pregnancy
Echogenic intracardiac focus &ndash; existence in the first trimester and the role of microRNAs
Echogenic intracardiac focus (EIF) constitutes a finding in the ultrasound study that indicates an area which is echogenically bright in the fetal heart and is as bright as the bone that moves synchronically to the atrioventricular valves. Microcalcifications of the papillary muscles or chordae tendinae are being represented by this echogenicity and are mostly present in the left ventricle (90% of cases). EIF appears usually at the ultrasound that is realized in the mid-trimester in a percentage that reaches 3.5% in euploid fetuses and 15% to 30% in fetuses with trisomy 21. In the current paper, the rare and curious case of a 21-year-old primigravida woman is described, who presented for ultrasound scan at the 12th week of gestation. The scan revealed the presence of EIF, which is very rare, as it is well-known that it usually appears in the second trimester of pregnancy. Counseling and debriefing for dismissing parents&rsquo; anxiety is necessary as well as further examinations, because EIF has low sensitivity. This specific case report could constitute a beginning in the research of whether investigating EIF in the first trimester of pregnancy is possible and which are the benefits of its detection for the mother, the fetus and the whole family, in clinical practice