Improving a Solid-State Qubit through an Engineered Mesoscopic Environment.

A controlled quantum system can alter its environment by feedback, leading to reduced-entropy states of the environment and to improved system coherence. Here, using a quantum-dot electron spin as a control and probe, we prepare the quantum-dot nuclei under the feedback of coherent population trapping and observe their evolution from a thermal to a reduced-entropy state, with the immediate consequence of extended qubit coherence. Via Ramsey interferometry on the electron spin, we directly access the nuclear distribution following its preparation and measure the emergence and decay of correlations within the nuclear ensemble. Under optimal feedback, the inhomogeneous dephasing time of the electron, T_{2}^{*}, is extended by an order of magnitude to 39 ns. Our results can be readily exploited in quantum information protocols utilizing spin-photon entanglement and represent a step towards creating quantum many-body states in a mesoscopic nuclear-spin ensemble.

Phase-Tuned Entangled State Generation between Distant Spin Qubits.

Quantum entanglement between distant qubits is an important feature of quantum networks. Distribution of entanglement over long distances can be enabled through coherently interfacing qubit pairs via photonic channels. Here, we report the realization of optically generated quantum entanglement between electron spin qubits confined in two distant semiconductor quantum dots. The protocol relies on spin-photon entanglement in the trionic Λ system and quantum erasure of the Raman-photon path information. The measurement of a single Raman photon is used to project the spin qubits into a joint quantum state with an interferometrically stabilized and tunable relative phase. We report an average Bell-state fidelity for |ψ^{(+)}⟩ and |ψ^{(-)}⟩ states of 61.6±2.3% and a record-high entanglement generation rate of 7.3 kHz between distant qubits.

Direct photonic coupling of a semiconductor quantum dot and a trapped ion.

Coupling individual quantum systems lies at the heart of building scalable quantum networks. Here, we report the first direct photonic coupling between a semiconductor quantum dot and a trapped ion and we demonstrate that single photons generated by a quantum dot controllably change the internal state of a Yb^{+} ion. We ameliorate the effect of the 60-fold mismatch of the radiative linewidths with coherent photon generation and a high-finesse fiber-based optical cavity enhancing the coupling between the single photon and the ion. The transfer of information presented here via the classical correlations between the σ_{z} projection of the quantum-dot spin and the internal state of the ion provides a promising step towards quantum-state transfer in a hybrid photonic network.

Optical stark effect and dressed exciton states in a Mn-doped CdTe quantum dot.

We report on the observation of spin-dependent optically dressed states and the optical Stark effect on an individual Mn spin in a semiconductor quantum dot. The vacuum-to-exciton or the exciton-to-biexciton transitions in a Mn-doped quantum dot are optically dressed by a strong laser field, and the resulting spectral signature is measured in photoluminescence. We demonstrate that the energy of any spin state of a Mn atom can be independently tuned by using the optical Stark effect induced by a control laser. High resolution spectroscopy reveals a power-, polarization-, and detuning-dependent Autler-Townes splitting of each optical transition of the Mn-doped quantum dot. This experiment demonstrates an optical resonant control of the exciton-Mn system.

[Significations of extremely elevated C-reactive protein: about 91 cases in a French hospital center]. / Significations d'une protéine C-réactive supérieure à 500mg/l: à propos de 91 prélèvements dans un centre hospitalier brestois.

This report is devoted to 91 extremely elevated protein C-reactive levels. Patients characteristics, etiologies of inflammation, comorbidities and microbiology are subjected to wide variations. Mortality is high (37 % and 51 %, 30 and 90 days later).

High thiopurine metabolite concentrations associated with lymphopenia in inflammatory bowel disease (IBD) pediatric patients receiving aminosalicylates combined with azathioprine.

OBJECTIVE: Aminosalicylates are widely used with azathioprine in the treatment of IBD. The association results in an increase in 6-TGN levels in adults with IBD with a difference in the occurrence of myelotoxic effects. Scarce data are available in pediatric population. We proposed to investigate the effect of the coadministration of aminosalicylates on thiopurine concentrations in pediatric IBD patients. MATERIALS AND METHODS: Data from 71 patients treated for at least 1 y by azathioprine and aminosalicylates were recorded. 6-TGN and 6-MeMPN concentrations, blood cell counts and liver function tests were compared between patients taking and those not taking aminosalicylates. RESULTS: Aminosalicylate therapy was associated with a significant increase in mean 6-TGN but also 6-MeMPN concentrations. In patients in remission, 6-TGN level was related to aminosalicylate dosage (r = 0.561, p = 0.010). Lymphopenia rate was higher in patients receiving combined therapy compared to monotherapy whereas a slight rise in leucopenia was found. CONCLUSIONS: This observation suggests that the higher frequency of lymphopenia may be associated with the elevated 6-TGN concentrations recovered in patients treated with aminosalicylates. This combination does not improve remission rate but could increase adverse effects especially lymphopenia.

[2008 update of the 8th Consensus Development Conference of the Francophone Society of Medical Emergencies of 1999. The treatment of adult renal colic by the emergency services and in emergency rooms]. / Actualisation 2008 de la 8e Conférence de consensus de la Société francophone d'urgences médicales de 1999. Prise en charge des coliques néphrétiques de l'adulte dans les services d'accueil et d'urgences.

The care in the emergencies of the renal colic at the adult was the object in 1999 of a conference of consensus of the French Society of Emergency (SFMU) in association with the French Association of Urology and the Society of Nephrology. This already former text was the object of an update in 2008 by the subcommittee of scientific monitoring of the SFMU and was presented to the congress 2008. This public presentation in the presence of an expert urologist allowed to confront this new text with the practices and to publish an updating of the conference of consensus of 1999. A survey of practice was led with the emergency physicians, whose results are presented.

Quantum interface of an electron and a nuclear ensemble.

Coherent excitation of an ensemble of quantum objects underpins quantum many-body phenomena and offers the opportunity to realize a memory that stores quantum information. Thus far, a deterministic and coherent interface between a spin qubit and such an ensemble has remained elusive. In this study, we first used an electron to cool the mesoscopic nuclear spin ensemble of a semiconductor quantum dot to the nuclear sideband-resolved regime. We then implemented an all-optical approach to access individual quantized electronic-nuclear spin transitions. Lastly, we performed coherent optical rotations of a single collective nuclear spin excitation-a spin wave. These results constitute the building blocks of a dedicated local memory per quantum-dot spin qubit and promise a solid-state platform for quantum-state engineering of isolated many-body systems.

[The organisation of intensive care in a situation of pandemic avian influenza]. / Organisation de la réanimation en situation de pandémie de grippe aviaire.

The development of an epidemic of avian influenza will have a major impact on the organisation and structure of the facilities for treatment. This paper, the product of collaboration between the six learned societies concerned, analyses the impact of a possible pandemic on the various aspects of management of patients requiring intensive care. It describes the organisation of hospital pathways for flu and non-flu patients with, in particular, the necessary actions in terms of separation of care facilities, the triage of patients and the cancellation of non-urgent activities. It analyses the preconditions necessary for the efficient functioning of intensive care and the predictable limiting factors. It underlines the importance of training of medical and paramedical personnel. Finally, it tackles the specific problems of paediatric intensive care: organisation, capacity for admissions and training.

[Outcome of the Aquitaine Unit for Evaluation, Training and Social and Vocational Counselling (UEROS) at 5-year follow-up in young adults with brain damage]. / Programme d'aide à la réinsertion sociale et professionnelle de jeunes adultes cérébrolésés: résultats à cinq ans du réseau UEROS-Aquitaine.

INTRODUCTION: Difficulties in social and vocational adjustment are common in adults with brain damage. A French government-funded program, UEROS (Unit for Evaluation, Training and Social and Vocational Counselling), was developed to improve cognitive adjustment, social autonomy and return to work for these people. OBJECTIVES: To describe the outcome and satisfaction with life after 5 years for patients who participated in the UEROS-Aquitaine network program. MAIN OUTCOME MEASURES: EBIS Document to evaluate people with traumatic brain injury. RESULTS: Seventy-five of the 102 patients participating in UEROS from 1997 to 1999 were assessed during a phone-structured interview based on the EBIS Document. The sample consisted of young adults (mean age 28.5 years), most (65, 85%) with brain injury and moderate disability (Glasgow Outcome Scale 2: 57%) or severe disability (Glasgow Outcome Scale 3: 42%). On entering the program, 33% of the subjects needed no help physically or cognitively. None were employed. At the end of the program, 9% were students or were learning a job, 8% worked full-time, 16% were in sheltered conditions, and 13% had volunteer activities. At 5-year follow-up, 50% of the subjects were independent, 4% were in school, 10.6% worked full-time, and 26.7% were in sheltered conditions. Playing sports was associated with good social adjustment. The professional status at 5 years was significantly correlated with following the UEROS program (r=0.30, P<0.01) and status at the end of the program (r=0.29, P<0.05). However, 41.3% of the subjects were still unsatisfied with their conditions of life. DISCUSSION-CONCLUSION: In patients with brain damage, the UEROS-Aquitaine network program improves independence in daily living and allows for nearly one inactive adult in two (42%) to be engaged in an activity or a job.

Quantum dot spin coherence governed by a strained nuclear environment.

The interaction between a confined electron and the nuclei of an optically active quantum dot provides a uniquely rich manifestation of the central spin problem. Coherent qubit control combines with an ultrafast spin-photon interface to make these confined spins attractive candidates for quantum optical networks. Reaching the full potential of spin coherence has been hindered by the lack of knowledge of the key irreversible environment dynamics. Through all-optical Hahn echo decoupling we now recover the intrinsic coherence time set by the interaction with the inhomogeneously strained nuclear bath. The high-frequency nuclear dynamics are directly imprinted on the electron spin coherence, resulting in a dramatic jump of coherence times from few tens of nanoseconds to the microsecond regime between 2 and 3 T magnetic field and an exponential decay of coherence at high fields. These results reveal spin coherence can be improved by applying large magnetic fields and reducing strain inhomogeneity.

Contribution of plasmid DNA to hepatotoxicity after systemic administration of lipoplexes.

Several studies have demonstrated that intravenous administration of DNA complexed with cationic lipid vectors induces the production of large quantities of proinflammatory cytokines. In this study we confirm these observations, using cationic lipid DOTAP and cationic phospholipid compounds. Moreover, we demonstrate that although intravenous administration of lipid-DNA complexes does not induce toxic effects in the lung, high transgene expression in lung correlates with histopathological lesions in liver, this fact being documented by high transaminase levels in serum of treated mice. We examine the contribution of various components of the lipoplexes in this observed liver toxicity, as well as in the increasing level of transaminases, and more particularly the role of nonmethylated CpG sequences of plasmid DNA. We show that blood samples from animals treated either with cationic lipid alone, or with cationic lipid complexed with methylated plasmid DNA, contain low levels of transaminases. The significant decrease in transaminase levels after injection of cationic lipid-methylated pDNA complexes leads us to believe that nonmethylated CpG sequences could play a major role in this hepatoxicity. Similar results were observed when using a vector that did not encode a transgene, demonstrating that the expression of luciferase in lung was not responsible for this liver toxicity. All these observations suggest that significant work should be devoted to understand more clearly the mechanism of cationic lipid-DNA complex toxicity, and to overcome the problems subsequent to administration of non-methylated CpG sequences of plasmid DNA.

Two novel severe mutations in the pancreatic secretory trypsin inhibitor gene (SPINK1) cause familial and/or hereditary pancreatitis.

Mutations in the serine protease inhibitor Kazal type 1 gene (SPINK1) encoding pancreatic secretory trypsin inhibitor (PSTI) have recently been found to be associated with chronic pancreatitis. Nevertheless, knowledge of severe mutations is particularly scarce, both in terms of number and in the extent of clinical information. The aim of this study was to expand the known spectrum of such mutations. 46 unrelated families, each including at least two pancreatitis patients and carrying neither cationic trypsinogen (PRSS1) mutations nor the frequent SPINK1 N34S mutation, participated in this study. The four exons and their flanking sequences of the SPINK1 gene were screened by denaturing high performance liquid chromatography analysis (DHPLC); and mutations were identified by direct sequencing. A heterozygous microdeletion mutation (c.27delC), which occurs within a symmetric element, was identified in two families. In one family, c.27delC showed segregation with the disease across two generations, with a penetrance of up to 75%. But in the other family, however, the same mutation manifested as a low-penetrance susceptibility factor. In addition, a novel heterozygous splicing mutation, c.87+1G>A (G>A substitution at nucleotide +1 of intron 2) was found in one family with familial pancreatitis. Our results also helped to resolve the sharply differing views about PSTI's role in pancreatitis.

Diagnostic and prognostic value of Cyfra 21-1 compared with other tumour markers in patients with non-small cell lung cancer: a prospective study of 116 patients.

The diagnostic value of Cyfra 21-1 in non-small lung cancer (NSCLC) has been established, but few studies have focused on its prognostic value. The aim of this study was to compare that of carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, CA 125, neuron-specific enolase and squamous cell carcinoma antigen. 116 patients with unresectable (n = 88) or resectable (n = 28) NSCLC were prospectively monitored from diagnosis, for a median of 14.4 months. All patients underwent tumour-marker determinations before treatment, then every 3 months. Their diagnostic value was studied using ROC (receiver operating characteristic) curves, based on control measure in 23 patients with benign lung diseases. The prognostic analysis was based on overall survival as the main endpoint. The diagnostic value of Cyfra 21-1 was confirmed, with a sensitivity of 54% and a specificity of 96% at a cut-off value of 3.3 ng/ml. At diagnosis, in the 88 non-surgical NSCLC, besides the presence of metastases (P = 0.017), Cyfra 21-1 (P = 0.017) and CA 125 (P = 0.03) were related to outcome. Elevated levels of Cyfra 21-1 at any time during the disease course was selected by multivariate analysis as additional predictors of poor survival.

Factors influencing the efficiency of lipoplexes mediated gene transfer in lung after intravenous administration 1 *.

The objectives of this study were to test the influence of different parameters on the in vivo cationic lipid mediated gene transfer in lung after intravenous administration. Luciferase activity was evaluated in lung tissue 24 hours after intravenous administration of different types of lipoplexes. These included lipoplexes prepared using cationic phosphonolipids or DOTAP and various amounts of plasmid DNA. Using two different plasmids we tested the influence of plasmid size on transfection efficiency in vivo. In a last series of experiments, lipoplexes were prepared using different excipients (water, NaCl or 5% glucose solution) and three injection volumes were tested. We demonstrate that chemical structure modifications such as cation substitution and increment of the aliphatic chain length significantly improve transfection efficiency. High luciferase levels are obtained by increasing lipid to DNA charge ratio and plasmid DNA dose and decreasing plasmid size. Lipoplexes prepared in physiological NaCl solution and injected using a volume of 800mul are significantly the most effective. Cationic lipid mediated gene transfer in lung tissue after intravenous administration is influenced by factors including cationic lipid chemical structure, lipid to DNA ratio and plasmid dose. Nevertheless, plasmid size, injection volume and the excipient, used for the lipoplexes preparation, are also important factors and must be considered for an optimization of in vivo gene delivery using intravenous administration.

[Ulceronecrotic tracheobronchial involvement in Crohn's disease]. / Atteinte trachéo-bronchique ulcéro-nécrotique au cours d'une maladie de Crohn.

We report the case of a young female patient hospitalized for the first episode of a colonic Crohn's disease with specific ulceronecrotic tracheobronchial involvement leading to chronic and invalidant cough. Symptomatic bronchopulmonary manifestations are very rare in the course of inflammatory bowel diseases and usually not mentioned in Gastroenterology textbooks.

[Nasal ulceration and trigeminal sensitive neuropathy. Apropos of a case and a review of the literature]. / Ulcération nasale et neuropathie trigéminale sensitive. A propos d'une observation et revue de la littérature.

A case of isolated trigeminal sensitive neuropathy revealed by a nasal ulceration is reported. Such case is quite unusual and requires a very thorough search for any local lesion or general pathology. The treatment is often disappointing.