357 research outputs found
Five-year follow-up after biliopancreatic diversion with duodenal switch
BACKGROUND: Only limited data are available for assessing the medium and long-term outcomes after bariatric surgery. We report our own long-term results after biliopancreatic diversion with duodenal switch (BPD-DS). METHODS: The data from 51 patients with a theoretical >/=5-year follow-up were reviewed after BPD-DS performed from February 2002 to October 2004. The patients were assessed every 3 months during their first postoperative year, every 6 months during the second year, and annually thereafter. RESULTS: The preoperative body mass index (BMI) was 47 +/- 6.1 kg/m(2). The first 23 patients had undergone open BPD-DS. The same procedure was used (150-mL sleeve, 150-cm alimentary limb, and 100-cm common channel) for the 28 laparoscopic BPD-DS procedures, although 15 patients underwent conversion to laparotomy at the beginning of our experience. No patients died postoperatively. Of the 51 patients, 7 were not available for follow-up: 2 patients had died 9 months after BPD-DS (1 of myocardial infarction and 1 after ventral hernia repair), 1 underwent reversal, 1 refused follow-up after a complicated postoperative course, and contact was lost with 3 patients (7.8% lost to follow-up). The 5-year BMI was 31 +/- 4.5 kg/m(2), with a mean excess weight loss of 71.9% +/- 20.6%. Of the 44 patients, 7 (15.9%) had an excess weight loss of <50%; 4 of these unsatisfactory results occurred after revision BPD-DS. After primary BPD-DS, excess weight loss of 75.8% +/- 18.0% was observed. Biologic data were obtained for 85% of the patients at 5 years. The main vitamin and micronutrients parameters remained stable over time. However, a trend was seen toward an increase in the parathormone levels and difficulties in maintaining a normal vitamin D level despite updated vitamin supplementation. CONCLUSION: The results of our study have shown that BPD-DS achieves sustainable significant weight loss with >5 years of follow-up, with unsatisfactory results in <20% of cases. Although not statistically significant, revision surgery more often resulted in lesser weight loss, although this difference had almost vanished when the initial BMI was taken as a reference compared with the BMI before BPD-DS
Kinks in the Hartree approximation
The topological defects of the lambda phi^4 theory, kink and antikink, are
studied in the Hartree approximation. This allows us to discuss quantum effects
on the defects in both stationary and dynamical systems. The kink mass is
calculated for a number of parameters, and compared to classical, one loop and
Monte Carlo results known from the literature. We discuss the thermalization of
the system after a kink antikink collision. A classical result, the existence
of a critical speed, is rederived and shown for the first time in the quantum
theory. We also use kink antikink collisions as a very simple toy model for
heavy ion collisions and discuss the differences and similarities, for example
in the pressure. Finally, using the Hartree Ensemble Approximation allows us to
study kink antikink nucleation starting from a thermal (Bose Einstein)
distribution. In general our results indicate that on a qualitative level there
are few differences with the classical results, but on a quantitative level
there are some import ones.Comment: 20 pages REVTeX 4, 17 Figures. Uses amsmath.sty and subfigure.sty.
Final version, fixed typo in published versio
Rapid and MR-Independent IK1 activation by aldosterone during ischemia-reperfusion
In ST elevation myocardial infarction (STEMI) context, clinical studies have shown the deleterious
effect of high aldosterone levels on ventricular arrhythmia occurrence and cardiac
mortality. Previous in vitro reports showed that during ischemia-reperfusion, aldosterone
modulates K+ currents involved in the holding of the resting membrane potential (RMP).
The aim of this study was to assess the electrophysiological impact of aldosterone on IK1
current during myocardial ischemia-reperfusion. We used an in vitro model of âborder zoneâ
using right rabbit ventricle and standard microelectrode technique followed by cell-attached
recordings from freshly isolated rabbit ventricular cardiomyocytes. In microelectrode experiments,
aldosterone (10 and 100 nmol/L, n=7 respectively) increased the action potential
duration (APD) dispersion at 90% between ischemic and normoxic zones (from 95±4ms to
116±6 ms and 127±5 ms respectively, P<0.05) and reperfusion-induced sustained premature
ventricular contractions occurrence (from 2/12 to 5/7 preparations, P<0.05). Conversely,
potassium canrenoate 100 nmol/L and RU 28318 1 ÎŒmol/l alone did not affect AP
parameters and premature ventricular contractions occurrence (except Vmax which was
decreased by potassium canrenoate during simulated-ischemia). Furthermore, aldosterone
induced a RMP hyperpolarization, evoking an implication of a K+ current involved in the
holding of the RMP. Cell-attached recordings showed that aldosterone 10 nmol/L quickly
activated (within 6.2±0.4 min) a 30 pS K+-selective current, inward rectifier, with pharmacological
and biophysical properties consistent with the IK1 current (NPo =1.9±0.4 in control vs
NPo=3.0±0.4, n=10, P<0.05). These deleterious effects persisted in presence of RU 28318,
a specific MR antagonist, and were successfully prevented by potassium canrenoate, a non
specific MR antagonist, in both microelectrode and patch-clamp recordings, thus indicating
a MR-independent IK1 activation. In this ischemia-reperfusion context, aldosterone induced
rapid and MR-independent deleterious effects including an arrhythmia substrate (increased
APD90 dispersion) and triggered activities (increased premature ventricular contractions
occurrence on reperfusion) possibly related to direct IK1 activation
Tachyonic preheating using 2PI-1/N dynamics and the classical approximation
We study the process of tachyonic preheating using approximative quantum
equations of motion derived from the 2PI effective action. The O(N) scalar
(Higgs) field is assumed to experience a fast quench which is represented by an
instantaneous flip of the sign of the mass parameter. The equations of motion
are solved numerically on the lattice, and the Hartree and 1/N-NLO
approximations are compared to the classical approximation. Classical dynamics
is expected to be valid, since the occupation numbers can rise to large values
during tachyonic preheating. We find that the classical approximation performs
excellently at short and intermediate times, even for couplings in the larger
region currently allowed for the SM Higgs. This is reassuring, since all
previous numerical studies of tachyonic preheating and baryogenesis during
tachyonic preheating have used classical dynamics. We also compare different
initializations for the classical simulations.Comment: 32 pages, 21 figures. Published version: Some details added, section
added, references added, conclusions unchange
A practical approach to estimate resting energy expenditure in frail elderly people
Objectives: Some prediction equations of resting energy expenditure (REE) are available and can be used in clinical wards to determine energy requirements of patients. The aim of the present study was to assess the accuracy of those equations in sick elderly patients, using the Bland & Altman methods with our database of 187 REE measurements.Design: The 3 equations tested were Harris & Benedict equation of 1919, WHO/FAO/UNU equation of 1985 and Fredrix et al. equation of 1990. In addition, three models developed from the present data were tested.Results: The present study shows that the Fredrix et al equation gave an accurate prediction of REE without significant bias along the whole range of REE. It also shows that under-weight sick elderly patients (BMI †21 kg/m2) had a greater weight-adjusted REE than their normal weight counterparts.Conclusion: A simple formula using a factor multiplying body weight, i.e. 22 kcal/kg/d in under-weight and 19 kcal/kg/d in normal weight sick elderly was accurate to predicting REE and bias was not influenced by the level of REE. This model included half of the group in the range of ±10% of the difference between predicted REE and measured REE, but the confidence interval of the bias was ±400 kcal/d. Conversely, the Harris & Benedict and WHO formulae did accurately predict REE
Promoting spontaneous second harmonic generation through organogelation
et al.An organogelator based on the Disperse Red nonlinear optical chromophore was synthesized according to a simple and efficient three-step procedure. The supramolecular gel organization leads to xerogels which display a spontaneous second harmonic generation (SHG) response without any need for preprocessing, and this SHG activity appears to be stable over several months. These findings, based on an intrinsic structural approach, are supported by favorable intermolecular supramolecular interactions, which promote a locally non-centrosymmetric NLO-active organization. This is in sharp contrast with most materials designed for SHG purposes, which generally require the use of expensive or heavy-to-handle external techniques for managing the dipoles' alignment.The authors sincerely acknowledge the University of Angers for funding an Arianes Fellowship as well as Angers Loire Metropole and the Region Pays de la Loire for their support through the LUMOMAT program (postdoctoral fellowship to F.A.). The authors are also grateful to the PIAM and the SCIAM platforms for their help. K.I. acknowledges support from the European Commission and General Secretariat for Research and Technology (Greece) for a National Strategic Reference Framework (NSRF) Project (PE3-(1612)). Research at the Universidad de Zaragoza was supported by MINECO
(CTQ2014-52331R) and Gobierno de Aragon-Fondo Social Europeo (E39). A predoctoral fellowship to A.B.M. (FPI BES-2009-016966), with EEBB FPI 2012 and 2013, is also acknowledged.Peer Reviewe
Synthesis, spectroscopic and electrochemical properties of new covalent assemblies between TTF and various acceptors
Five new acceptor-ÏâTTF-Ï-acceptor (AâDâA) triads that contain pyridine, quinoline, nitrophenyl or nitrofuryl groups as acceptor unit have been synthesized by two-fold Wittig olefination reactions and their electrochemical behavior has been studied by cyclic voltammetry (CV). The intramolecular charge transfer (ICT) band in these molecules was characterized by UVâvisible electronic absorption spectroscopy and these studies were completed by DFT calculations in the gas phase. These materials appear to be good candidates for the preparation of electroactive discrete metal complexes or coordination polymers as well as for the preparation of radical cations salts
Phosphorescent self-assembled PtII tetranuclear metallocycles
A series of rigid Pt(ii) diimine diacetylide complexes and their corresponding metallocyclic derivatives were synthesized through coordination-driven self-assembly. The photophysical properties of these complexes have been studied in detail, revealing exceptionally high RT phosphorescence quantum yields and lifetimes when the excited state becomes localized on the [small pi]-conjugated bridging-ligand following intramolecular charge-transfer sensitization
Prevalence of sarcopenia in the French senior population
Introduction A muscle mass normalized for height2 (MMI) or for body weight (SMI) below 2SD under the mean for a young population defines sarcopenia. This study aimed at setting the cutoffs and the prevalence of sarcopenia in the French elderly population. Another objective was to compare the results obtained with SMI and MMI.Methods: Muscle mass was assessed by bioelectrical impedance analysis in 782 healthy adults (<40 years) to determine skeletal mass index (SMI, muscle mass*100/weight) and muscle mass index (MMI, muscle mass/height2). Prevalence was estimated in 888 middle aged (40â59 years) and 218 seniors (60â78 years). All were healthy people.Results: For women mean-2SD were 6.2 kg/m2 (MMI) and 26.6% (SMI); for men limits were 8.6 kg/m2 (MMI) and 34.4% (SMI). In middle aged persons a small number of them were identified as sarcopenic. In healthy seniors, 2.8% of women and 3.6% of men were sarcopenic (MMI). The prevalence was 23.6% in women and 12.5% in men with SMI. MMI and SMI identified different sarcopenic populations, leaner subjects for MMI while fatter subjects for SMI.Conclusion: Cutoff values for the French population were defined. Prevalence of sarcopenia was different from that in the US population
Bark beetle population dynamics in the Anthropocene: Challenges and solutions
Tree-killing bark beetles are the most economically important insects in conifer forests worldwide. However, despite N200 years of research, the drivers of population eruptions and crashes are still not fully understood and the existing knowledge is thus insufficient to face the challenges posed by the Anthropocene. We critically analyze potential biotic and abiotic drivers of population dynamics of an exemplary species, the European spruce bark beetle (ESBB) (Ips typographus) and present a multivariate approach that integrates the many drivers governing this bark beetle system. We call for hypothesis-driven, large-scale collaborative research efforts to improve our understanding of the population dynamics of this and other bark beetle pests. Our approach can serve as a blueprint for tackling other eruptive forest insects
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