Quasiparticle Andreev scattering in the ν = 1/3 fractional quantum Hall regime

The scattering of exotic quasiparticles may follow different rules than electrons. In the fractional quantum Hall regime, a quantum point contact (QPC) provides a source of quasiparticles with field effect selectable charges and statistics, which can be scattered on an 'analyzer' QPC to investigate these rules. Remarkably, for incident quasiparticles dissimilar to those naturally transmitted across the analyzer, electrical conduction conserves neither the nature nor the number of the quasiparticles. In contrast with standard elastic scattering, theory predicts the emergence of a mechanism akin to the Andreev reflection at a normal-superconductor interface. Here, we observe the predicted Andreev-like reflection of an e/3 quasiparticle into a - 2e/3 hole accompanied by the transmission of an e quasielectron. Combining shot noise and cross-correlation measurements, we independently determine the charge of the different particles and ascertain the coincidence of quasielectron and fractional hole. The present work advances our understanding on the unconventional behavior of fractional quasiparticles, with implications toward the generation of novel quasi-particles/holes and non-local entanglements.

Facteurs de risque suicidaire et troubles dépressifs

L’objectif de notre étude comparative est d’isoler des facteurs de risque de passage à l’acte suicidaire en cas de troubles dépressifs. Des patients adultes déprimés sont inclus dans l’étude, après 48 heures d’hospitalisation dans le service de psychiatrie, en distinguant les patients déprimés admis suite à une Tentative de Suicide (groupe « TS ») et les patients déprimés sans TS (groupe « Control »). Le bilan clinique est effectué à l’aide d’auto-questionnaires et d’hétéro-évaluations (Hamilton, coping, insight, dépendance interpersonnelle…) [1–4].

Alors que les deux groupes possèdent des caractéristiques sociodémographiques ainsi que des dimensions dépressives comparables, cette étude montre que les patients « TS » sont plus isolés socialement et ont des ATCD familiaux de TS pour 67 % d’entre eux (contre 31 % chez les « Control »). Ces patients « TS » ont un pauvre insight comparé aux patients « Control » et ont une conscience partielle de leurs troubles psychiatriques. Aussi, les deux groupes se distinguent clairement selon les facteurs de coping, tout en ne montrant pas de différence au niveau de la dépendance interpersonnelle. À partir de ces données, nous proposons de nous interroger sur les modalités de sortie des patients déprimés et de discuter d’un programme spécifique de suivi ambulatoire post-crise.

Psychiatric and physical outcomes of long-term use of lithium in older adults with bipolar disorder and major depressive disorder: A cross-sectional multicenter study

OBJECTIVE

Although lithium is widely used in current practice to treat bipolar disorder (BD) and treatment-resistant major depressive disorder (MDD) among older adults, little is known about its efficacy and tolerability in this population, which is generally excluded from randomized clinical trials. The objective of this study was to evaluate the efficacy and tolerability of long-term use of lithium among older adults with BD and MDD.

METHOD

Data from the Cohort of individuals with Schizophrenia and mood disorders Aged 55 years or more (CSA) were used. Two groups of patients with BD and MDD were compared: those who were currently receiving lithium versus those who were not. The effects of lithium on psychiatric (i.e., depressive symptoms severity, perceived clinical severity, rates of psychiatric admissions in the past-year), geriatric (overall and cognitive functioning) and physical outcomes (i.e., rates of non-psychiatric medical comorbidities and general hospital admissions in the past-year) were evaluated. All analyses were adjusted for age, sex, duration of disorder, diagnosis, smoking status, alcohol use, and use of antipsychotics, antiepileptics or antidepressants.

RESULTS

Among the 281 older participants with BD or MDD, 15.7% were taking lithium for a mean duration of 12.5(SD = 11.6) years. Lithium use was associated with lower intensity of depressive symptoms, reduced perceived clinical global severity and lower benzodiazepine use (all p < 0.05), without being linked to greater rates of medical comorbidities, except for hypothyroidism.

LIMITATIONS

Data were cross-sectional and data on lifetime history of psychotropic medications was not assessed.

CONCLUSION

Our results suggest that long-term lithium use may be efficient and relatively well-tolerated in older adults with BD or treatment-resistant MDD.

Subjective Experiences and Sensitivities in Women with Fibromyalgia: A Quantitative and Comparative Study

Fibromyalgia is a chronic widespread pain syndrome associated with chronic fatigue. Its pathogenesis is not clearly understood. This study presents subjective experiences and sensitivities reported by fibromyalgia patients, which should be considered in primary care to avoid medical nomadism, as well as stigmatization of the patients. The prevalence of significant characteristics was compared with others patients consulting at the same pain unit who suffer from rebel and disabling form of chronic migraine. Psychometric tests were anonymously completed by 78 patients of the Pain Unit (44 fibromyalgia patients and 34 migraine patients). Tests evaluated pain (Visual Analog scale), childhood traumas (Childhood Trauma Questionnaire), lack of parental affection, stressful life events (Holmes and Rahe Scale), anxiety and depression (Hospital Anxiety and Depression Scale), perceived hypersensitivity to 10 stimuli, and hyperactivity before illness. However, pain scores were comparable in the two groups, and the prevalence was significantly higher in fibromyalgia patients than in migraine patients for anxiety (81.8% versus 51.5%) and depression (57.1% versus 8.8%). Childhood physical abuses were more frequently reported in fibromyalgia than in migraine cases (25% versus 3%). Similarly, the feeling of lack of parental affection, subjective hypersensitivity to stress and stimuli (cold, moisture, heat, full moon, and flavors) or hyperactivity (ergomania), appeared as prominent features of fibromyalgia patients. Fibromyalgia patients considered themselves as being hypersensitive (mentally and physically) compared to migraine patients. They also have higher depression levels. Beyond somatic symptoms, precociously taking account of psychosocial and behavioral strategies would highly improve treatment efficiency of the fibromyalgia syndrome.

Surface-Induced Near-Field Scaling in the Knudsen Layer of a Rarefied Gas

We report on experiments performed within the Knudsen boundary layer of a low-pressure gas. The noninvasive probe we use is a suspended nanoelectromechanical string, which interacts with ^{4}He gas at cryogenic temperatures. When the pressure P is decreased, a reduction of the damping force below molecular friction ∝P had been first reported in Phys. Rev. Lett. 113, 136101 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.136101 and never reproduced since. We demonstrate that this effect is independent of geometry, but dependent on temperature. Within the framework of kinetic theory, this reduction is interpreted as a rarefaction phenomenon, carried through the boundary layer by a deviation from the usual Maxwell-Boltzmann equilibrium distribution induced by surface scattering. Adsorbed atoms are shown to play a key role in the process, which explains why room temperature data fail to reproduce it.

Dépendance aux psychothérapies cognitivocomportementales chez les états-limites

Confrontés à une liste d’attente permanente pour les prises en charge en psychothérapies dans le service, il nous a paru important de nous questionner sur les raisons d’une embolisation des consultations, ceci par un nombre limité de patients border-line, décrit comme hyper-consommateurs de soins ambulatoires pendant plusieurs années, tout en étant en difficultés pour bénéficier d’un suivi psychothérapeutique régulier. Nous nous sommes alors intéressés à comparer le parcours de soins, les caractéristiques cliniques d’un groupe de ces patients états limites, pris en charge en TCC, que nous considérions comme « dépendants » de leur psychothérapie, par rapport à un groupe d’autres personnalités pathologiques. À partir des problèmes institutionnels que pose la prise en charge de ce type de patients, nous nous interrogerons sur la notion d’addiction aux psychothérapies par comparaison aux autres addictions et nous discuterons les modalités de gestion de cette dépendance bien particulière.

[Mitochondrial neurogastrointestinal encephalopathy disease]

Mitochondrial neurogastrointestinal encephalopathy disease (MNGIE) is a rare autosomal-recessive syndrome, resulting from mutations in the TYMP gene, located at 22q13. The mutation induces a thymidine phosphorylase (TP) deficit, which leads to a nucleotide pool imbalance and to instability of the mitochondrial DNA. The clinical picture regroups gastrointestinal dysmotility, cachexia, ptosis, ophthalmoplegia, peripheral neuropathy, and asymptomatic leukoencephalopathy. The prognosis is unfavorable. We present the case of a 14-year-old Caucasian female whose symptoms started in early childhood. The diagnosis was suspected after magnetic resonance imaging (MRI), performed given the atypical features of mental anorexia, which revealed white matter abnormalities. She presented chronic vomiting, postprandial abdominal pain, and problems gaining weight accompanied by cachexia. This diagnosis led to establishing proper care, in particular an enteral and parenteral nutrition program. There is no known specific effective treatment, but numerous studies are in progress. In this article, after reviewing the existing studies, we discuss the main diagnostic and therapeutic aspects of the disease. We argue for the necessity of performing a cerebral MRI given the atypical features of a patient with suspected mental anorexia (or when the clinical pattern of a patient with mental anorexia seems atypical), so that MNGIE can be ruled out.

Slippage and boundary layer probed in an almost ideal gas by a nanomechanical oscillator

We measure the interaction between ⁴He gas at 4.2 K and a high-quality nanoelectromechanical string device for its first three symmetric modes (resonating at 2.2, 6.7, and 11 MHz with quality factor Q>0.1×10⁶) over almost 6 orders of magnitude in pressure. This fluid can be viewed as the best experimental implementation of an almost ideal monoatomic and inert gas of which properties are tabulated. The experiment ranges from high pressure where the flow is of laminar Stokes-type presenting slippage down to very low pressures where the flow is molecular. In the molecular regime, when the mean-free path is of the order of the distance between the suspended nanomechanical probe and the bottom of the trench, we resolve for the first time the signature of the boundary (Knudsen) layer onto the measured dissipation. Our results are discussed in the framework of the most recent theories investigating boundary effects in fluids (both analytic approaches and direct simulation Monte Carlo methods).

[Comparative study of thoracoscopy versus thoracotomy in esophageal atresia]

INTRODUCTION

Thoracoscopic treatment of esophageal atresia type 3 has been previously reported to be feasible but no study clearly showed the benefits of thoracoscopy compared to open procedure. The aim of this study was to compare the outcome of esophageal atresia type III treated by thoracoscopic or open procedure.

MATERIAL AND METHOD

From january 2000 to december 2006, 31 children were operated, 17 by thoracotomy (weight range from 1750 to 4020 g) and 14 by thoracoscopy (weight range from 2110 to 4160 g). Neonatal deaths from an independent condition (3 cases in thoracotomy group) were excluded from the study and we analyzed 14 children in each group. Analyzed data included length of surgery, length of post operative assisted ventilation, length of pleural drainage, length of stay in ICU, delay before oral feeding, length of morphine analgesia, length of hospitalization and rate of complication.

RESULTS

Length of morphine analgesia was higher in thoracotomy group than in thoracoscopic group (mean 6.6 days versus 5.3 days, p = 0.16). Length of hospitalization was also higher in thoracotomy group (mean 22.6 days versus 19.1 days, p = 0.3). The rate of complication with thoracoscopy was not higher need of oesophageal dilatation (21% in thoracoscopic group versus 14% in thoracotomy group), need of Nissen fundoplication (21% in thoracoscopic group versus 28% in thoracotomy group).

CONCLUSION

Thoracoscopic treatment of esophageal atresia type III reduces the need of morphine analgesia and the length of stay without increasing the risk of postoperative complications.

[Ileocecal intussusception secondary to a cecal endometriosis]

We report the case of a 43-year-old woman, who presented a complete and non-reductible ileo-cecal intussusception with pre-occlusion. An ileocecal resection with ileocolic anastomosis was performed. The pathologic examination confirmed the diagnosis of colic endometriosis with transmural lesions, causing the intussusception. Altough the digestive endometriosis is quite classical and well-known, particulary with vermiform appendix and rectosigmoïd involvement, ileo-cecal intussusception secondary to endometriosis is rare.

Possible role for TNF-alpha in early embryopathy associated with maternal diabetes in the rat

Tumor necrosis factor (TNF) bioactivity was assessed in culture media conditioned with uterine cells collected from control or diabetic rats on days 5 and 8 of pregnancy. On both days, diabetic uterine cells released significantly more biologically active TNF than did control cells, and this activity was significantly decreased by the addition of anti-TNF-alpha antibodies but not by the addition of normal IgG when WEHI 164 cells were used as a target. When uterine tissues from day 5 or day 8 pregnant diabetic rats were tested by Northern blot analysis, TNF-alpha mRNAs were twofold more abundant than in control samples, but the difference was not statistically significant (P = 0.086 and 0.100, respectively). Immunohistochemical analysis of diabetic day 5 uterine sections revealed that most of the TNF-alpha synthesis occurs in the epithelium lining the uterine lumen. Finally, the growth of day-5 embryos in culture medium conditioned with day-5 diabetic uterine cells was significantly reduced when compared with that of embryos in medium conditioned with control cells. Embryonic development was markedly improved when anti-TNF-alpha antibodies were added to the diabetic-cell conditioned medium. Our data support the hypothesis that TNF-alpha may be implicated in the developmental deficiencies observed in preimplantation embryos from pregnant diabetic rats.