Search

This paper presents an innovative anti-seismic device for controlling the out-of-plane rocking motion of masonry walls with traditional tie-rods, called LInear COntrolled Rocking Device (LICORD). LICORD is a low-impact box connected to the extremity of the traditional tie-rod designed to mitigate rocking for medium–high intensity earthquakes. Additionally, the paper widens the knowledge about the dynamic behavior of rocking walls through the interpretation of the results of an extensive experimental campaign performed on masonry specimens composed by clay brick and cementitious mortar. Firstly, the LICORD’s single components are tested to identify their stiffness and damping properties. Secondly, free vibration tests provide actual values of coefficients of restitution on free-standing walls and walls restrained by LICORD, where the walls vary for the height to thickness ratio. For the stockier wall, the ratio of experimental/analytical coefficient of restitution varies from 88 to 98%, whereas for the slender wall, the results are less scattered, with a minimum value of 95% and a maximum value of 96%. The restrained walls are characterized by coefficients of restitution from 5 to 25% less than the values found for unrestrained walls, depending on the equivalent viscous coefficient of the shock absorbers. Moreover, LICORD demonstrated to properly absorb and damp the oscillations of the wall and control its rocking motion, strongly reducing the number of impacts and the rotation amplitudes up to 70%. Considerations about the effect of one-sided motion on the assessment of coefficient of restitution are also given. The equivalent viscous damping coefficients are observed to be on the range 4% (unrestrained wall) and 7–20% for walls restrained by LICORD.

This paper analyzes the influence of horizontal damped and undamped restraints in terms of the amplification of the response of rocking masonry walls subjected to seismic excitations. It al...

This study deals with the identification of the mechanical behavior of chemical anchors embedded in masonry walls. 108 pull-out tests are carried out in five types of masonry walls built with clay brick or vertically perforated units with cement mortar. Different parameters are taken into account: embedment depths, masonry type, anchor position (injection either in brick units or in mortar joints). The axial load capacity and the failure mode are observed for each test. The results are examined by means of elastic and plastic models assessing the efficiency of anchors installed in headers, stretchers or mortar joints. The anchors injected in mortar joints are shown to have much greater pull-out capacity than that found for anchors in bricks. Passing from 90 to 160 mm of embedment depth, a minimum increase by 40% of pull-out strength is observed. The most common failure modes are the sliding failure, which occurs for short anchors or weak masonry, and mixed sliding/cone failure, for long anchors or strong masonry. An analytical model is proposed to design anchors in order to avoid or at least to limit brittle masonry failures and to identify the field of application of uniform stress models.

In seismically active areas the design of wind turbine must be verified for seismic load combinations. These consider a certain likelihood of earthquake occurrence during normal operation, which could eventually lead to an emergency stop. In order to simulate these scenarios, the computational model should take into account the aerodynamics of the rotor, the flexibility of tower and soil, transient operational phases and, first and foremost, the interrelation of all these aspects. At the same time, the complexity should be reduced in order to avoid enormous computational costs, especially when the soil-structure interaction is taken into account. This study presents a practical model for the analysis of the soil-structure interaction effects on the seismic behavior of wind turbine, during normal power production and emergency shutdown. The presented model is based on simplified lumped parameter model for the soil-foundation subsystem and is validated against a detailed model, based on a 3D coupled finite element method and scaled boundary finite element method approach. This article shows a demonstrative example for a reference 5MW wind turbine subjected to a seismic event which triggers an emergency shutdown. The application of the lumped parameter model allows a significant model size reduction and accurate approximation of the soil-structure behavior in time domain.

Investigating the nonlinear dynamic response of reinforced concrete (RC) structures is of significant importance in understanding the expected behavior of these structures under dynamic loading. This becomes more crucial during the design of new or the assessment of the existing RC structures that are located in seismically active areas. The numerical simulation of this problem through the use of detailed 3D modeling is still a subject that has not been investigated thoroughly due to the significant challenges related to numerical instabilities and excessive computational demand, especially when the soil–structure interaction (SSI) phenomenon is accounted for. This study aims at presenting a nonlinear simulation tool to investigate this numerically cumbersome problem in order to provide further inside into the SSI effect on RC structures under nonlinear dynamic loading conditions. A detailed 3D numerical model of full-scale RC structures considering the SSI effect through modeling the nonlinear frame and soil domain is performed and discussed herein. The constructed models are subjected to dynamic loading conditions and an elaborate investigation is presented considering different type of structures, material properties of soil domains and depths. The RC structures and the soil domains are modeled through 8-noded hexahedral isoparametric elements, where the steel bar reinforcement of concrete is modeled as embedded beam and truss finite elements. The Ramberg–Osgood constitutive law was used for modeling the soil domain. It was shown that the SSI effect can significantly increase the flexibility of the system, altering the nonlinear dynamic response of the RC frames causing local damages that are not observed when the fixed-base model is analyzed. Furthermore, it was found that the structures founded on soft soil developed larger base-shear compared to the fixed-base model which is attributed to resonance phenomena connected to the SSI effect and the imposed accelerograms.

In order to simulate wind turbines under different load scenarios, the computational model should take into account the aerodynamics of the rotor, the flexibility of tower, foundation and soil, transient operational phases and, first and foremost, the interaction of all these aspects. Whenever vibrations are emitted to soil, they induce waves traveling through the ground. Here, the main focus lies on the Soil-Structure-Interaction (SSI) effects on the dynamic behavior of operating wind turbines. The wind turbine with its foundation and the surrounding soil is modeled by a coupled Finite Element Method/Scaled Boundary Finite Element Method approach.

Depicting numbers in a graphical way has always been crucial to understand and explain the physical phenomena behind. Interactive graphical applications bring the understanding to a higher level, where the users get actively engaged. Moreover, interactive visualization of data, equations etc.… help to motivate students and strengthen the sharing of knowledge. At the Technical University of Munich, the Chair of Structural Mechanics and the Research Group Algebra developed interactive applications in the fields of mechanics and higher mathematics. Students can access the applications online at any time, without installation or special requirements, and, thus, can actively explore the content with a very low entry barrier. For example, they can experiment with a spring‐mass‐damper system and let it enter the resonance by changing the frequency of the excitation; or they can search for local maxima and minima of a function with side conditions with the Lagrange multipliers in an interactive and graphical way. The interactive process enhances the understanding, even if the user does not interact with a strategy but just uses his intuition. These applications can be also used to explain complex concepts to the general public. The source code is publicly available on https://github.com/ChairOfStructuralMechanicsTUM/Mechanics_Apps .

In this contribution we present a strategy to investigate the vibrations of onshore wind turbines subjected to simultaneous aerodynamic loads and seismic loads. The latter result from the propagation of seismic waves through the underlying soil and are governed by the Lamé’s equations. The structure and its foundation as well as parts of the soil are modeled by Finite Element Method (FEM). The infinite half-space is discretized by Scaled Boundary Finite Element Method (SBFEM). Both methods are coupled at the common interface. The seismic excitation is expressed as a 3D seismic wave field and transformed into boundary tractions, which are then applied at the interface between the near and far fields. The aerodynamic actions are generated with an additional aerodynamic tool and are applied at the tower head. The proposed method can be used also to investigate the 3D nonlinear response of the near field, where nonlinear material properties can be assigned to any element of FEM part.

The introduction of new applications such as the spatiotemporal image correlation (STIC) and the tomographic ultrasound imaging (TUI) has greatly enhanced the study of cardiac and vessels anatomy. The aim of our study was to assess the feasibility of including real-time volumetric 3D reconstruction of heart anatomy and Doppler angiography of great vessels during routine second trimester pregnancy scan, in a low-risk population. Visualization of the pulmonary veins, ductus venosus and inferior vena cava was significantly superior with 3D ultrasound. Therefore, STIC makes it possible to store heart beats for a mean time of 10 s, to replay acquired volumes in slow motion, to study the heart atrium along three axes and retrace volumetric image storage inversely from the apex to the base of the heart, making reconstruction of the four-chamber view and great artery outflow tract much easier and faster. Furthermore, the use of digital communication allow operators to store and send volume of images that can be postprocessed by external consultant specialists worldwide. Although 3D echocardiography is less time-consuming and independent of fetal positioning in utero when compared with 2D it may be premature to include 3D and 3D Doppler angiography among routine examination. However, the study of the outflow tracts by 2D echocardiography should be implemented in order to improve the diagnostic accuracy of CHDs. At present, only "targeted" cases in which a routine 2D scan has raised diagnostic doubts should undergo a second level sonography for a thorough 2D-3D examination of cardiac and vessels anatomy.

UNLABELLED A Methodical Study: AIM OF THE STUDY To analyse the feasibility of colour and spectral Doppler assessment of blood flow in the fetal right (RPA) and left (LPA) main pulmonary arteries in relation to fetal position and to gestational age. STUDY DESIGN The fetal position was a priori divided into 3 types, depending on whether the fetal heart was visualised apically (Type 1), from the right side (Type 2) or from the left side (Type 3). Three groups A (19-25 weeks gestation), B (26-32) and C (33-39) including 33 consecutive pregnancies each, were examined to document the fetal position as well as the rate of the successful Doppler examinations of the RPA and/or LPA. RESULTS The fetal position Type 2 was most common throughout gestation (in group A = 42%, B = 36%, C = 51%) followed by the type 3 and then type 1. The rate of successful Doppler records from the RPA and LPA depended on the fetal position: In Type 2 RPA in 98%; in Type 3, LPA in 100%; but the apical approach was not effective ( 85%), whereas successful examination of both vessels was unlikely (12%). CONCLUSIONS In the second half of pregnancy, independent of fetal position, Doppler examination of at least one pulmonary artery is successful in most cases, whereas the assessment of both vessels is rather difficult.

According to the Oxford English Dictionary, ‘real-time’ means the actual time during which a process or event takes place, particularly an event or process analyzed by a computer. As opposed to ‘real time’, ‘subsequent time’ indicates a later time at which an event can be elaborated by a computer or at which a recording can be reproduced. For what specifically concerns ultrasound imaging, the expression ‘real-time’ should be reserved to describe the ability of an ultrasound system to image moving anatomical structures at the exact time when anatomical data are acquired, or in the worst case to do it with a negligible time delay between acquisition and visualization. This would imply that 2D images or 3D volumes are refreshed with a frequency equal or higher to human retinal vision persistence.

The number of patients affected by systemic lupus erythematosus (SLE) that decide to have children has greatly increased probably because of recent improvements in the diagnosis and management of the disease. This has stimulated our interest in defining the outcome of children, focusing both on neonatal problems and long term development. SLE patients still carry a risk of pregnancy loss. However, due to careful monitoring and treatment by a multidisciplinary team, the number of losses has dramatically decreased, but an increased number of preterm deliveries is still a problem. Neonatal lupus is linked to the presence of anti-Ro/SS-A and anti-La/SS-B antibodies in the mother, although other factors probably of fetal origin are important. Neonatal lupus is a complex condition whose most serious manifestation is the congenital heart block (CHB). Usually, children with complete CHB need permanent pacing, but apparently do not have neuropsychological problems. Studies focusing on the neuropsychological development of SLE offspring show an increased number of learning disabilities in children with normal intelligence levels. Fetal consequence of maternal treatment need to be considered choosing non teratogenic drugs, but the withdrawal of medications just because the patient is pregnant should be avoided to avoid SLE flares.

If a woman suffers from autoimmune disease (AD), several factors can affect pregnancy or neonatal outcome: repeated spontaneous pregnancy losses (frequently related to antiphospholipid antibodies (aPL)), neonatal lupus with complete congenital heart block (CHB) (linked to transplacental passage of IgG anti Ro/SS-A antibodies) and the disease activity itself that can affect the mother, the pregnancy and fetal outcome. If appropriately managed, the antiphospholipid syndrome (APS) is "one of the few tractable causes of pregnancy losses." A recent case control study, on babies from APS-mothers and healthy mothers, did not show any difference in the occurrence of neonatal complications. There are few data about the long-term outcome of babies born to patients with AD. We recently reported increased occurrence of learning disabilities in children born to aPL positive mothers with systemic lupus erythematosus (SLE). The modern management of pregnancy in patients with AD includes the treatment of disease flares, using drugs effective but safe for fetus. Corticosteroids and some immunosuppressive drugs can be used in pregnancy to control maternal disease. A prolonged fetal exposure to dexamethasone was reported to impair cerebral development, but we recently studied 6 children, born to patients treated with dexamathasone because of CHB, showing a normal intelligence quotient. The last 10-year experience shows that fetal exposure to antimalarial drugs should not be regarded as an important risk factor for gestational nor neonatal complications. However, information about long-term outcome of children exposed to immunosuppressive drugs "in utero" are still lacking and more efforts are needed in this research area.

Objectives: To describe the natural history of pyelectasis from its detection in the second trimester to delivery, its capability to predict renal pathology and whether prenatal development of pelvic dilatation is correlated to its postnatal evolution. Study design: A retrospective analysis involving 375 fetuses with a complete urological follow-up. Prenatal ultrasound was correlated with the results of postnatal investigation and frequency of postnatal surgery was established. Results: Two-hundred and eighty cases underwent at least two examinations before birth. 73.1% were male fetuses. 57.4% had a bilateral pyelectasis. Prenatal evolution of pelvic dilatation was the following:18.6% of the cases normalized, in 34.6% of the cases the dilatation reduced but did not disappear, in 30.7% it remained unchanged, while it worsened in 16.4%. One case from the first group, three cases from the second, seven cases from the third and 11 cases from the fourth needed surgical treatment. 1.9, 7.2, 18.6, 23.9% of cases respectively worsened after birth in the four groups (trend: P = 0.001). Conclusions: Prenatal diagnosis of pyelectasis improves the outcome of these children due to a surgical approach that avoids renal damage. There is a good correlation between prenatal evolution and postnatal outcome, although a postnatal follow-up is opportune in those cases that normalized before birth.

To correlate umbilical artery Doppler velocimetry with perinatal outcome in a group of growth-restricted fetuses.The study was a retrospective analysis of 578 singleton pregnancies with diagnosis of intrauterine growth restriction (IUGR), delivered in a single obstetric unit, at the Spedali Civili, Brescia, Italy, a university and teaching hospital with 3500 deliveries a year and neonatal intensive care unit (NICU).During 1991-99 we studied 578 pregnancies with a diagnosis of IUGR referred for Doppler velocimetry. From this population, four subsets were formed: normal umbilical artery pulsatility index (NUAPI; 334 fetuses); increased pulsatility index but with telediastolic flow (abnormal umbilical artery pulsatility index AUAPI; 137 fetuses); absent end-diastolic flow (AEDF; 70 fetuses); reverse telediastolic flow (RF; 37 fetuses). Fetal biometry, amniotic fluid and fetal-maternal Doppler velocimetry were evaluated in all patients, with biophysical profile and routine non-stress test, when indicated. The following outcomes were examined: mean gestational age at delivery, number of preterm deliveries (34 weeks), mean neonatal weight, Apgar score at 5 min7, prenatal and neonatal deaths (within the first 28 days of life), admission to the NICU and number of days spent after birth in hospital. Neonatal morbidity was analyzed, including respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH, grade 2-3), necrotizing enterocolitis (NEC) and retinopathy of prematurity. Long-term neurological follow-up is still ongoing and will not be presented in this paper.Out of 578 fetuses with IUGR, 547 were born alive. There were 26 neonatal deaths. The mean gestational age at delivery was 35.6 +/- 4 weeks and mean birth weight 1844 +/- 612 g. There were 28 intrauterine deaths and three elective terminations of pregnancy. A total of 60 cases (11%) were complicated by RDS, 13 cases (2.4%) by retinopathy of prematurity, IVH was present in nine cases (1.6%) and NEC in seven cases (1.3%). Total perinatal mortality was 9.8%; in the 26 cases of neonatal death, the mean week at delivery was 29.6 +/- 4 with a mean weight of 840 +/- 425 g. Patients with NUAPI had a mean week at delivery of 37 +/- 3, those with AUAPI delivered at 34 +/- 3.2, those with AEDF delivered at 31 +/- 3 and those with RF delivered at 29 +/- 2 weeks. In progressively worsening umbilical velocimetry, we observed an increase of incidence of low Apgar score. Days of admission to the NICU and incidence of perinatal mortality increased with the worsening of Doppler velocimetry.Our study underlines the existence of a strict correlation between umbilical Doppler velocimetry and an increased incidence of perinatal complications in IUGR fetuses.

The objective of this study was to describe the normal blood flow velocity waveforms in the main branches of the right and left pulmonary arteries in the human fetus and to establish reference ranges for different Doppler parameters during the second half of pregnancy. Cross-sectional data were collected from 86 healthy human singleton fetuses between 18 and 38 weeks of gestation. With advancing gestation a significant increase (p < 0.001) in the peak systolic velocity, time averaged velocity and time velocity integral was observed. The pulsatility index decreased significantly (p < 0.05) in the same period, suggesting a decrease in the pulmonary arterial vascular resistance. The acceleration time (AT) and the ratio of AT to ejection time (AT/ET), described in postnatal cardiology as having an inverse correlation with mean arterial pressure, increased significantly (p < 0.001). This is possibly the result of decreased pulmonary arterial pressure. The data show that Doppler examination of blood flow in the main stem of both the right and the left pulmonary arteries of the fetus is feasible, and increases insight into the lung perfusion of the human fetus. The observed changes throughout gestation are in accordance with animal experiments showing an increase in perfusion as well as a decrease in the vascular resistance and pressure.

Because of its minor environmental impact, electricity generation using wind power is getting remarkable. The further growth of the wind industry depends on technological solutions to the challenges in production and construction of the turbines. Wind turbine tower vibrations, which limit power generation efficiency and cause fatigue problems with high maintenance costs, count as one of the main structural difficulties in the wind energy sector. To mitigate tower vibrations auxiliary measures are necessary. The effectiveness of tuned mass damper is verified by means of a numeric study on a 5 MW onshore reference wind turbine. Hereby, also seismic-induced vibrations and soil–structure interaction are considered. Acquired results show that tuned mass damper can effectively reduce resonant tower vibrations and improve the fatigue life of wind turbines. This chapter is also concerned with tuned liquid column damper and a semiactive application of it. Due to its geometric versatility and low prime costs, tuned liquid column dampers are a good alternative to other damping measures, in particular for slender structures like wind turbines.

The structural behavior of modern wind turbines has reached a very high complexity and many factors are involved: slenderness of the structure, excitation environment and operational controls. Moreover, if a project is located at sites with relevant seismic hazard, the wind unit must be designed considering a reasonable likelihood of earthquake occurrence during the operational state or an emergency shutdown. The influence of the subsoil on the seismic response of a wind turbine can be crucial during the seismic design phase and need to be properly included into the computational model. Norms and guidelines need to keep up with technological developments and structural peculiarities. However the dynamic soilstructure interaction is often neglected or roughly mentioned. It is usually suggested to represent the soil through springs. The proposed investigation estimates the seismic response of a soil-turbine system and involves a 1.5-MW, 3- blade wind turbine, grounded on a layered half space. The wind turbine system is modeled by means of Finite Element Method (FEM). The effects of the layering are investigated. The soil is simply idealized as a generalized spring, according to the majority of standard codes. In parallel, the same investigation is performed with a more accurate method, a coupling between finite element and Boundary Element Method (BEM). This allows assessing the applicability and accuracy of the simplified soil representation.

The objective of this study was to describe blood flow velocity waveforms of fetal peripheral pulmonary arteries in normally grown and growth-retarded fetuses. Doppler studies were performed in 182 normally grown fetuses (gestational age 18-40 weeks) and in 61 growth-retarded fetuses (gestational age 24-36 weeks) that were free from structural and chromosomal abnormalities and whose umbilical and middle cerebral artery Doppler findings suggested uteroplacental insufficiency as the most likely etiology of the growth defect. The pulsatility index was used to quantify the velocity waveforms. Successful recordings were obtained in 90.1% of the normally grown and 93.4% of the growth-retarded fetuses. In normally grown fetuses the pulsatility index values significantly decreased with advancing gestation. In growth-retarded fetuses the pulsatility index values were significantly elevated compared to those of normal fetuses. A significant relationship was observed between the severity of hypoxia and pulsatility index values from the peripheral pulmonary arteries in 29 fetuses in which Doppler recordings were obtained immediately before cordocentesis. In conclusion, these data show that in normal fetuses the Doppler-measured impedance to flow in the peripheral pulmonary circulation decreases with advancing gestation. Impedance to flow in the lungs is elevated in the presence of growth retardation and this increase is related to the severity of fetal hypoxia.

Pulsed Doppler velocimetry of the fetal aortic and pulmonary valves derived in the five-chamber-view and short-axis view were performed in 88 uncomplicated pregnancies between the 20th and 40th week of gestation. The maximal and mean velocities were assessed for both semilunar valves. Considering the valve diameters and heart rate the stroke volume and cardiac output for both ventricles were calculated. Furthermore, the common stroke volume, common cardiac output and the ratio of right to left cardiac output were calculated. Normal ranges for all these parameters were constructed and correlated with gestational age. The maximal velocities were higher in the aorta than in the pulmonary trunk, but no differences were found in the mean velocities. The stroke volume and cardiac output of the right ventricle were in higher ratio 1.3:1 than that of the left ventricle as an expression of the right ventricular dominance in the fetus. Intracardiac Doppler flow velocimetry gives an insight into the physiology of fetal circulation and is a basis for the analysis of blood flow under pathological conditions.

Congenital heart defects (CHD) are the most frequent malformation in the human fetus and are the leading cause of mortality due to malformations in the first year of life. Despite its clinical importance screening performed by ultrasonographic examination during the second trimester of pregnancy has shown disappointingly low detection rates mainly due to the difficulties in obtaining an adequate examination of the fetal heart. Four-dimensional (4D) ultrasound of the fetal heart has been recently suggested as a tool to improve the detection rate of CHD by decreasing the dependency on operator skills required in two-dimensional ultrasound scans but up to now no practical manuals are available in describing its application in clinical practice for the study of fetal heart. The objective of this Ebook is to explain the role of 4D during second trimester examination and in fetuses with CHD. The technique of obtaining 4D volume of the fetal heart, how to navigate in the volume to obtain diagnostic planes and how to use semiautomatic and automatic software of analysis are described. We believe that after reading this book the standard fetal cardiac anatomy survey can be performed in the second trimester fetus by 4D in both normal and abnormal hearts. This approach may reduce the operator dependency in diagnosis CHD. This Ebook should prove to be a valuable resource for obstetricians, sonographers and pediatric cardiologists.

Objective To evaluate the initial experience at our centre in the treatment of monochorionic twin pregnancies complicated by twin reversed arterial perfusion sequence (TRAP), using radiofrequency ablation (RFA) with expandable needles, and to review the existing literature on the subject. Study design Between July 2007 and October 2010, 11 monochorionic twin pregnancies complicated by TRAP were referred to our centre. Seven patients underwent intrafetal ablation of the acardiac twin with RFA using LeVeen™ expandable needle electrodes. Data on the procedures and the obstetric outcome were reviewed, and subsequently we performed a review of the literature on the use of RFA in TRAP. Results Median gestational age at the intervention was 17 +3 weeks (range 14 +1 –23 +1 weeks). Technical success was obtained in all cases. Preterm premature rupture of membranes (PPROMs) occurred in 4/7 (57%) patients. Intrauterine death of the pump twin occurred in one patient at 21 +5 weeks, and one patient opted for termination of pregnancy because of PPROM at 21 +4 weeks. Five fetuses were delivered alive at a median gestational age of 33 +0 weeks (range 31 +0 –39 +5 weeks). All five infants (71%) were alive and had a normal examination at 6 months of age. The review identified 6 studies, for a total of 78 pregnancies (either monochorionc twins or triplets with a monochorionic component). Including our data, overall neonatal survival was 75/88 (85%). Conclusion RFA appears to be a relatively safe and reliable technique in the treatment of TRAP sequence pregnancies. Further research is needed to define the best timing of the procedure.

Objectives Ex utero Intrapartum Treatment (EXIT) is a technique to secure the fetal airway while oxygenation is maintained through utero-placental circulation. The aim of the study is to present three cases of fetal lymphatic malformation of the head and neck that required EXIT and to summarize EXIT details. Methods The cases were studied before the delivery and EXIT was planned with a multidisciplinary team. The key factors of EXIT are considered and the type, stage and clinical score of the three lymphatic malformations are defined. Results In the three cases of EXIT the time working on placental support to secure the airway was 9, 7, and 9 min, respectively (from the hysterotomy to clamping the umbilical cord). Procedures performed on the airway were laryngo–tracheo–bronchoscopy in the first case, laryngoscopy and intubation in the second one, laryngoscopy, drainage of the lymphatic macro-cyst, and intubation in the third case. A sketching to detail the EXIT steps are presented: EXIT-Team Time Procedure list (EXIT-TTP list). Lymphatic malformations were classified as mixed (micro/macro-cystic) in two cases, and macro-cystic in one. de Serres Stage was IV, V and II. Therapy varied in the three neonates (surgery alone, surgery + Picibanil® + Nd-YAG, or Picibanil® alone). Conclusions In case of prenatal suspicion of airway obstruction, EXIT should be planned with a multidisciplinary team. The EXIT-Team Time Procedure list (EXIT-TTP list), reviews the most critical phases of the procedure when different teams are working together. The type of lymphatic malformation, the anatomic location and the clinical score predict the outcome.

We report a case of monochorionic twin pregnancy complicated by twin-twin transfusion syndrome (TTTS) diagnosed in the late second trimester and treated with two amnioreductions. Three days after the first amniodrainage, the recipient twin developed intracranial ventriculomegaly and, similarly, after a few days, the donor showed signs of brain damage at MRI. We discuss the possible mechanism of brain damage of amnioreductions performed after 26 weeks of gestation in a monochorionic pregnancy with TTTS as a result of a placental ‘steal’ phenomenon.

Objective To evaluate the incidence and the strategy of management of syncope admitted urgently to a general hospital. Background The management of patients with syncope is not standardized. Methods The study was a prospective observational registry from a sample of 28 general hospitals in Italy and enroled all consecutive patients referred to their emergency rooms from November 5th 2001 to December 7th 2001 who were affected by transient loss of consciousness as the principal symptom. Results The incidence of syncope was 0.95% (996 of 105,173 patients attending). Forty-six percent were hospitalized, mostly in the Department of Internal Medicine. The mean in-hospital stay was 8.1±5.9 days. A mean of 3.48 tests was performed per patient. A definite diagnosis was made in 80% of cases, neurally-mediated syncope being the most frequent. The findings of each of the 28 hospitals participating in the survey were separately evaluated. We observed great inter-hospital and inter-department heterogeneity regarding the incidence of emergency admission, in-hospital pathways, most of the examinations performed and the final assigned diagnosis. For example, the execution of carotid sinus massage ranged from 0% in one hospital to 58% in another (median 12.5%); tilt testing ranged from 0 to 50% (median 5.8%); the final diagnosis of neurally-mediated syncope ranged from 10 to 78.6% (median 43.3%). Conclusion Great inter-hospital and inter-department heterogeneity in the incidence and management of syncope was observed in general hospitals. As a consequence, we were unable to describe a uniform strategy for the management of syncope in everyday practice.

To relate prenatal data of monochorionic pregnancies complicated by Twin-Twin transfusion syndrome (TTTS) with survival rates and neurological morbidity.Thirty-two cases of TTTS underwent biweekly ultrasound examinations. Amnioreduction was the standard of care. Mortality and neurological morbidity were evaluated; the children had neurodevelopmental follow-up with a mean follow-up time of 24 months.Ten out of 32 pregnancies terminated before 24 weeks of gestation, six after induction and four after spontaneous abortion. Among the 22 pregnancies followed up after 24 weeks, the overall survival rate at 28 days was 70% (31/44) with 10 intrauterine deaths including three cases of single selective terminations, and with three neonatal deaths. Eighteen out of 31 babies (58%) had a normal neurological development, eight cases had major and five cases minor neurological disabilities. Neonatal survival was not related to gestational age at diagnosis, number of amnioreductions or weeks at delivery. Absence of end diastolic flow in the umbilical artery, either in the donor or the recipient twin, and birth weight1000 g were both associated with a higher perinatal mortality. Number of amnioreductions (2) and birth weight1000 g were both associated with abnormal neurological follow-up.In TTTS, absent end diastolic flow in the umbilical artery and birth weight can predict perinatal survival; neurological development is correlated with number of amnioreductions and birth weight.

A parallel Asset & Liability Management (ALM) code was developed by SMART and Prometeia Calcolo for the EC project PALMA (Parallel Asset and Liability MAnagement). The code implements a stochastic approach based on a dynamic ALM model specially tailored for the Italian financial market. This paper reports the performances obtained on the Cray T3E at CINECA, running the code on real data provided by Credito Italiano. Very good scalability and efficiency have been achieved. Anyway the code is easily portable on other, possibly heterogeneous, high performance computing platforms.

Die Arbeit gibt eine Ubersicht uber die pranatale Erfassung der Hamodynamik in der Lunge. Seit der Einfuhrung der Farbdopplersonographie in die pranatale Diagnostik, konnten neue Erfahrungen auf dem Gebiet der Analyse der Lungenarterien und -venen gewonnen werden. Nach Darstellung der Entwicklung und der Besonderheiten des fetalen Lungenkreislaufs, wird in der Arbeit die systematische sonographische Beurteilung der rechten und linken Lungenarterien und -venen erlautert. Ferner werden Daten zur Biometrie der Lungenarterien, sowie zur Dopplersonographie der zentralen und peripheren Pulmonalarterien unter normalen und pathologischen Bedingungen vorgestellt. Die Beurteilung der Lungenvenen wird erklart, nicht nur unter Berucksichtigung des Dopplerspektrums unter normalen und pathologischen Bedingungen, sondern auch unter dem Aspekt der pranatalen Diagnostik der Lungenvenenfehlmundung. Die Analyse der fetalen pulmonalen Hamodynamik konnte in Zukunft nicht nur in der Entdeckung von Fehlbildungen, sondern auch moglicherweise in der Voraussage von neonatalen Lungenerkrankungen, wie die Lungenhypoplasie oder die pulmonale Hypertension, eine wichtige Rolle spielen.

The Astronomers target for the present and the next decade is the construction of large telescopes 3,5 - 4 m. primary mirror diameter and very large telescopes 8 - 9 m. primary mirror diameter, in the array or multi-mirror design, improving at the same time the performance of the instruments compared to the efficiency and precision of the same.

The purpose of this study was to validate methods for the perioperative management of diabetic patients that meet the prerequisites of simplicity, applicability in the absence of a diabetologist, and flexibility, to rapidly meet changing metabolic requirements. The patients were divided into two groups that were comparable for age, sex distribution, type of diabetes, and type of surgical procedures. The results show that intravenous insulin administration achieved better glycemic control during the intraoperative period, whereas it did not offer advantages over the subcutaneous route during the pre- and postoperative periods. The satisfactory degree of steady glycemic control achieved and the absence of hypoglycemic episodes indicate that the separate administration of insulin and glucose plus electrolytes is an effective and safe management modality for diabetic patients undergoing major surgery.

Objective. The purpose of this study was to assess the interobserver reproducibility of transabdominal 3-dimensional (3D) fetal neurosonography. Methods. This was a prospective observational study. We studied 23 consecutive singleton pregnancies between 18 and 23 weeks’ gestation. All cases had normal fetal neurosonographic examination findings, which were confirmed after birth. A 3D sonographic volume of the fetal head was acquired transabdominally by a single operator using an axial approach. Fetal brain anatomy was later analyzed offline by 2 different operators. Axial, sagittal, and coronal views of the fetal brain were obtained to perform a detailed evaluation of the fetal brain. Each operator defined the scanning planes obtained as adequate or inadequate. Results were evaluated with 2 × 2 tables and the Cohen κ coefficient to assess interobserver agreement. Results. Good-quality multiplanar images were obtained in 23 of 23 cases. The rate of adequate visualization was 100% for all of the axial planes, with κ values of 1.00. For sagittal and coronal planes, the rate of visualization ranged between 78% and 91%, with κ values ranging between 0.61 and 0.83. Conclusions. Transabdominal 3D sonography of the fetal brain at 18 to 23 weeks’ gestation has an acceptable degree of interobserver reproducibility. Key words: brain; interobserver agreement; neurosonography; 3-dimensional sonography.