Two decades of aortic coarctation treatment in children; evaluating techniques.

OBJECTIVE: This study focuses on the evolution of treatment techniques for aortic coarctation in children and assesses long-term morbidity. METHODS: This retrospective cohort study evaluates patients treated for native aortic coarctation, with at least 7 years of follow-up. To assess time-related changes, three time periods were distinguished according to year of primary intervention (era 1, 2 and 3). Operative and long-term follow-up data were collected by patient record reviews. RESULTS: The study population consisted of 206 patients (177 surgical and 29 catheter-based interventions), with a median follow-up of 151 months. Anterior approach with simultaneous repair of aortic arch and associated cardiac lesions was more common in the most recent era. Median age at intervention did not change over time. Reintervention was necessary in one third of the cohort with an event-free survival of 74% at 5­year and 68% at 10-year follow-up. Reintervention rates were significantly higher after catheter-based interventions compared with surgical interventions (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.04-3.00, p = 0.04) and in patients treated before 3 months of age (HR 2.1, 95% CI 1.27-3.55, p = 0.003). Hypertension was present in one out of five patients. CONCLUSION: Nowadays, complex patients with associated cardiac defects and arch hypoplasia are being treated surgically on bypass, whereas catheter-based intervention is introduced for non-complex patients. Reintervention is common and more frequent after catheter-based intervention and in surgery under 3 months of age. One fifth of the 206 patients remained hypertensive.

Clinical, oncological, and functional outcomes of Da Vinci (Xi)-assisted versus conventional laparoscopic resection for rectal cancer: a prospective, controlled cohort study of 51 consecutive cases.

PURPOSE: Despite the increasing use of telemanipulators in colorectal surgery, an additional benefit in terms of improved perioperative results is not proven. The aim of the study was to compare clinical, oncological, and functional results of Da Vinci (Xi)-assisted versus conventional laparoscopic (low) anterior resection for rectal cancer. METHODS: Monocenter, prospective, controlled cohort study with a 12-month follow-up of bladder and sexual function using the validated questionnaires International Prostate Symptom Score, International Index of Erectile Function, and Female Sexual Function Index. RESULTS: Fifty-one patients were included (18, Da Vinci (Xi) assisted; 33, conventional laparoscopy). Conversion to an open approach was more common in the Da Vinci cohort (p = 0.012). In addition, surgery and resumption of a normal diet took longer in the robotic group (p = 0.005; p = 0.042). Surgical morbidity and oncological quality did not differ. There was no difference in most functional domains, except for worsened ability to orgasm (p = 0.047) and sexual satisfaction (p = 0.034) in women after conventional laparoscopy. Moreover, we found a higher rate of improved bladder function in the conventional laparoscopy group (p = 0.023) and less painful sexual intercourse among women in the robot-assisted group (p = 0.049). CONCLUSION: In contrast to the ROLARR trial, a higher conversion rate was found in the robotic cohort, which may in part be explained by a learning curve effect. Nevertheless, the Da Vinci-assisted approach showed favorable results regarding sexual function.

[Early recognition and screening consultation: a necessary way to improve early detection and treatment in rheumatology? : Overview of the early recognition and screening consultation models for rheumatic and musculoskeletal diseases in Germany]. / Früh- und Screeningsprechstunden: Ein notwendiger Weg zur besseren Frühversorgung in der internistischen Rheumatologie? : Rheumatologische Früh- und Screeningsprechstundenmodelle in Deutschland.

In order to reduce the prognostically relevant time interval between the initial manifestation of a rheumatic and musculoskeletal disease and diagnosis as well as the consecutive initiation of an appropriate treatment, several rheumatological centers in Germany have improved the access to initial rheumatologic evaluation by establishing early recognition/screening clinics at their respective sites. Corresponding models located at Altoetting·Burghausen, Bad Pyrmont, Berlin Buch, Duesseldorf, Heidelberg, Herne, Mannheim as well as supraregional/multicenter initiatives Rheuma Rapid, RhePort and Rheuma-VOR are presented in this overview along with the respective characteristics, potential advantages and disadvantages, but also first evaluation results of several models. The aim of this publication is to promote early detection of rheumatic and musculoskeletal diseases as one of the most important challenges in current rheumatology by encouraging further rheumatologic centers and practices to launch their own early recognition/screening consultation model on the basis of aspects presented herein.

Perioperative hospital mortality at a tertiary paediatric institution.

BACKGROUND: Research in postoperative mortality is scarce. Insight into mortality and cause of death might improve and innovate perioperative care. The objective for this study was to report the 24-hour and 30-day overall, and surgery and anaesthesia-related, in-hospital mortality at a tertiary paediatric hospital. METHODS: All patients <18 yr old who underwent anaesthesia with or without surgery between January 1, 2006, and December 31, 2012, at the Wilhelmina Children's Hospital, Utrecht, The Netherlands, were included in this retrospective cohort study. Causes of death within 30 days were identified and tabulated into four major categories according to principal cause. RESULTS: A total of 45,182 anaesthetics were administered during this 7-yr period. The all-cause 24-hour hospital mortality was 13.1 per 10,000 anaesthetics (95% CI: 9.9-16.8) and the all-cause 30-day in-hospital mortality was 41.6 per 10,000 anaesthetics (95% CI: 35.9-48.0). In total five patients were partially contributable to anaesthesia (30-day mortality: 1.1/10,000, 95% CI: 0.4-2.6) and four patients were partially contributable to surgery (30-day mortality: 0.9/10,000, 95% CI: 0.2-2.3). Mortality was higher in neonates and infants, children with ASA physical status III and IV, and emergency- and cardiothoracic surgery. CONCLUSIONS: Neonates and infants, children with ASA physical status III or poorer, and emergency- and cardiothoracic surgery are associated with a higher postoperative mortality. Anaesthesia- or surgery-related complications contribute to mortality in only a small amount of the deaths, indicating the relative safety of paediatric surgical and anaesthetic procedures.

Giant magnetoconductance oscillations in hybrid superconductor-semiconductor core/shell nanowire devices.

The magnetotransport of GaAs/InAs core/shell nanowires contacted by two superconducting Nb electrodes is investigated, where the InAs shell forms a tube-like conductive channel around the highly resistive GaAs core. By applying a magnetic field along the nanowire axis, regular magnetoconductance oscillations with an amplitude in the order of e(2)/h are observed. The oscillation amplitude is found to be larger by 2 orders of magnitude compared to the measurements of a reference sample with normal metal contacts. For the Nb-contacted core/shell nanowire the oscillation period corresponds to half a flux quantum Φ0/2 = h/2e in contrast to the period of Φ0 of the reference sample. The strongly enhanced magnetoconductance oscillations are explained by phase-coherent resonant Andreev reflections at the Nb-core/shell nanowire interface.

Fusion hindrance for a positive-q-value system (24)Mg+(30)Si.

Measurements of the excitation function for the fusion of (24)Mg+(30)Si (Q=17.89 MeV)have been extended toward lower energies with respect to previous experimental data. The S-factor maximum observed in this large, positive-Q-value system is the most pronounced among such systems studied thus far. The significance and the systematics of an S-factor maximum in systems with positive fusion Q values are discussed. This result would strongly impact the extrapolated cross sections and reaction rates in the carbon and oxygen burnings and, thus, the study of the history of stellar evolution.

Neutron pair transfer in (60)Ni+(116)Sn far below the Coulomb barrier.

An excitation function of one- and two-neutron transfer channels for the ^{60}Ni+^{116}Sn system has been measured with the magnetic spectrometer PRISMA in a wide energy range, from the Coulomb barrier to far below it. The experimental transfer probabilities are well reproduced, for the first time with heavy ions, in absolute values and in slope by microscopic calculations which incorporate nucleon-nucleon pairing correlations.

Nanoimprint and selective-area MOVPE for growth of GaAs/InAs core/shell nanowires.

We report on the technology and growth optimization of GaAs/InAs core/shell nanowires. The GaAs nanowire cores were grown selectively by metal organic vapor phase epitaxy (SA-MOVPE) on SiO(2) masked GaAs (111)B templates. These were structured by a complete thermal nanoimprint lithography process, which is presented in detail. The influence of the subsequent InAs shell growth temperature on the shell morphology and crystal structure was investigated by scanning and transmission electron microscopy in order to obtain the desired homogeneous and uniform InAs overgrowth. At the optimal growth temperature, the InAs shell adopted the morphology and crystal structure of the underlying GaAs core and was perfectly uniform.

Realization of nanoscaled tubular conductors by means of GaAs/InAs core/shell nanowires.

We investigated the transport properties of GaAs/InAs core/shell nanowires grown by molecular beam epitaxy. Owing to the band alignment between GaAs and InAs, electrons are accumulated in the InAs shell as long as the shell thickness exceeds 12 nm. By performing simulations using a Schrödinger-Poisson solver, it is confirmed that confined states are present in the InAs shell, which are depleted if the shell thickness is below a threshold value. The existence of a tubular-shaped conductor is proved by performing magnetoconductance measurements at low temperatures. Here, flux periodic conductance oscillations are observed which can be attributed to transport in one-dimensional channels based on angular momentum states.

Plasmon dispersion and Landau damping in the nonlinear quantum regime.

We study the dispersion properties of electron plasma waves, or plasmons, which can be excited in quantum plasmas in the nonlinear regime. In order to describe nonlinear electron response to finite amplitude plasmons, we apply the Volkov approach to nonrelativistic electrons. For that purpose, we use the Schrödinger equation and describe the electron population of a quantum plasma as a mixture of quantum states. Within the kinetic framework that we are able to derive from the Volkov solutions, we discuss the role of the wave amplitude on the nonlinear plasma response. Finally, we focus on the quantum properties of nonlinear Landau damping and study the contributions of multiplasmon absorption and emission processes.

Minimizing circulatory arrest by using antegrade cerebral perfusion for aortic arch reconstruction in infants causes fewer postoperative adverse events.

BACKGROUND: Because deep hypothermic circulatory arrest (DHCA) carries a risk for neurological damage, antegrade cerebral perfusion (ACP) is used increasingly for aortic arch surgery in infants. We assessed the short-term effects of minimal DHCA (< 30 minutes) versus prolonged DHCA (> 30 minutes) during biventricular aortic arch reconstruction. METHODS: Twenty-six infants (< 3 months of age) who had undergone aortic arch reconstruction were retrospectively analyzed: 15 infants without DHCA (group A) and 11 infants with DHCA (group B). Group B was further divided into < 30 minutes DHCA (group B1, n = 6), and >or= 30 minutes DHCA (group B2, n = 5). Additionally, minimal DHCA (group A + B1) was compared to prolonged DHCA (group B2). RESULTS: In the minimal DHCA group (A + B1), 29 % of the patients had a postoperative adverse event, compared to 80 % in the prolonged DHCA group (B2) ( P < 0.05). Average length of stay in hospital was 25 days shorter for the minimal DHCA group (15 days versus 40 days, P < 0.01). CONCLUSION: Minimal DHCA results in fewer adverse events and a reduced length of stay, compared with prolonged DHCA. Therefore, during aortic arch surgery in infants, DHCA should be minimized by using antegrade cerebral perfusion.

Quantum and classical dynamics of Langmuir wave packets.

The quantum Zakharov system in three spatial dimensions and an associated Lagrangian description, as well as its basic conservation laws, are derived. In the adiabatic and semiclassical cases, the quantum Zakharov system reduces to a quantum modified vector nonlinear Schrödinger (NLS) equation for the envelope electric field. The Lagrangian structure for the resulting vector NLS equation is used to investigate the time dependence of the Gaussian-shaped localized solutions, via the Rayleigh-Ritz variational method. The formal classical limit is considered in detail. The quantum corrections are shown to prevent the collapse of localized Langmuir envelope fields, in both two and three spatial dimensions. Moreover, the quantum terms can produce an oscillatory behavior of the width of the approximate Gaussian solutions. The variational method is shown to preserve the essential conservation laws of the quantum modified vector NLS equation. The possibility of laboratory tests in the next generation intense laser-solid plasma compression experiment is discussed.

Macroscopic description for the quantum Weibel instability.

The Weibel instability in the quantum plasma case is treated by means of a fluidlike (moments) approach. Quantum modifications to the macroscopic equations are then identified as effects of the first or second kind. Quantum effects of the first kind correspond to a dispersive term, similar to the Bohm potential in the quantum hydrodynamic equations for plasmas. Effects of the second kind are due to the Fermi statistics of the charge carriers and can become the dominant influence for strong degeneracy. The macroscopic dispersion relations are of higher order than those for the classical Weibel instability. This corresponds to the presence of a cutoff wave number even for the strong temperature anisotropy case.

Phase-space structures in quantum-plasma wave turbulence.

The quasilinear theory of the Wigner-Poisson system in one spatial dimension is examined. Conservation laws and properties of the stationary solutions are determined. Quantum effects are shown to manifest themselves in transient periodic oscillations of the averaged Wigner function in velocity space. The quantum quasilinear theory is checked against numerical simulations of the bump-on-tail and two-stream instabilities. The predicted wavelength of the oscillations in velocity space agrees well with the numerical results.

[Fast-track laparoscopic radical prostatectomy]. / "Fast-track" bei laparoskopisch radikaler Prostatektomie.

BACKGROUND: Fast-track surgery describes perioperative treatment concepts ensuring a faster postoperative convalescence phase. By using a multimodal fast-track concept in patients undergoing laparoscopic radical prostatectomy, we aimed to investigate the feasibility of this procedure after elective surgery and a possible discharge 3 days postoperatively. PATIENTS AND METHODS: Twenty-five patients per group were randomized for conventional or fast-track treatment, respectively. Perioperative data, early complications, possible hospital discharge, and readmission rate were analyzed. Before hospital discharge, all patients were interviewed about their evaluation of the received regimen and their overall satisfaction perioperatively. RESULTS: The mean postoperative hospital stay was 3.6 days in the fast-track group vs. 6.7 days in the conventional group (p<0.01). Overall complications were low but were significant between the two groups, with the fast-track procedure being more favorable. Readmission rate was also low but was not significant. Overall satisfaction was significantly higher in the fast-track group, whereas the subjective evaluation did not differ between the two regimens. CONCLUSIONS: Fast-track concepts are well transferable in laparoscopic radical prostatectomy settings. Patients receiving this procedure, as well as clinics offering it, may benefit from a suitable fast-track concept.

Role of the mast cell in the pulmonary pressor response to hypoxia.

This study investigated the role of the mast cell in the pulmonary arterial pressor response to hypoxia. We found that pulmonary arteries 50-500 mu in diameter have a predictable distribution of perivascular mast cells; that such pulmonary mast cells are degranulated in vivo during alveolar hypoxia; that hypoxia releases histamine from mast cells isolated from the peritoneal cavity without apparent injury to the cells; and that histamine is released from the lung of intact guinea pigs during alveolar hypoxia, with the rise in pulmonary vascular resistance during this period proportional to the amount of histamine released. These data point to the perivascular pulmonary mast cell in the rat and guinea pig as an important structure in the mediation of the pulmonary pressor response to hypoxia, even though the responsible humoral vasoconstrictor released from such a cell may not be histamine, or histamine alone.

Aortico-right ventricular tunnel: prenatal diagnosis leading to neonatal survival.

In the 36th week of gestation a large aortico-right ventricular tunnel with an otherwise structurally normal heart was diagnosed by fetal echocardiography. This report describes for the first time the impact of the timely prenatal diagnosis of an aortico-right ventricular tunnel followed by successful management in early infancy.

Ion-beam-plasma interaction effects on electrostatic solitary wave propagation in ultradense relativistic quantum plasmas.

Understanding the transport properties of charged particle beams is important not only from a fundamental point of view but also due to its relevance in a variety of applications. A theoretical model is established in this article, to model the interaction of a tenuous positively charged ion beam with an ultradense quantum electron-ion plasma, by employing a rigorous relativistic quantum-hydrodynamic (fluid plasma) electrostatic model proposed in McKerr et al. [M. McKerr, F. Haas, and I. Kourakis, Phys. Rev. E 90, 033112 (2014)PLEEE81539-375510.1103/PhysRevE.90.033112]. A nonlinear analysis is carried out to elucidate the propagation characteristics and the existence conditions of large amplitude electrostatic solitary waves propagating in the plasma in the presence of the beam. Anticipating stationary profile excitations, a pseudomechanical energy balance formalism is adopted to reduce the fluid evolution equation to an ordinary differential equation. Exact solutions are thus obtained numerically, predicting localized excitations (pulses) for all of the plasma state variables, in response to an electrostatic potential disturbance. An ambipolar electric field form is also obtained. Thorough analysis of the reality conditions for all variables is undertaken in order to determine the range of allowed values for the solitonic pulse speed and how it varies as a function of the beam characteristics (beam velocity and density).