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.

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.

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.

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.

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.

Early surgical site infection in adult appendicular skeleton trauma surgery: a multicenter prospective series.

INTRODUCTION: Surgical site infections (SSI) studies rely on an imprecise and debatable definition. The term "wound healing problems" (WHP), not necessarily septic, is also frequently cited. This study had the objectives of determining the frequency of early SSIs in traumatology, these terms eventual correlation, and the factors influencing onset. PATIENTS AND METHODS: A multicenter prospective observational study was conducted in 12 centers. The exclusion criteria were open lesions as well as multiple injuries and multiple fractures (more than two fractures treated surgically). All patients were followed for the first three postoperative months until there was clinical certainty of healing and absence of infection. The presence of any WHP or SSI required a minimum follow-up of 1 year. WHP and SSI risk factors were determined using logistical regression adjusted on the centers. RESULTS: Out of 1617 cases, 103 were complicated by a WHP and 22 by a SSI. The SSIs were mainly secondary to Staphylococcus infections. The factors predisposing the patients to WHP and SSI (p≤0.05) were age; the NNIS, ASA, and Parker scores; alcoholism; antiaggregant use; and the locoregional aspect at the time of injury. The 522 subcutaneous osteosyntheses "near the skin" resulted in 58 WHPs (11%) and 14 SSIs (2.7%); 13 of the 58 WHPs (22%) resulted in one SSI. Out of 707 deep osteosyntheses, 24 (3.4%) presented a WHP and seven (1%) a SSI; Four SSIs originated from a WHP. The 352 fractures of the trochanter were complicated by a WHP in 15 cases (5.5%) and a SSI in one case (0.4%) after interlocked nailing and two WHPs and two SSIs (2.5%) after screw and plate fixation. Of the 388 first-line arthroplasties, only the prostheses implanted for a proximal femur fracture presented complications: 21 WHPs (6%) and one SSI (0.02%). Of the 103 WHPs of the entire series, 18 became SSIs. In absence of WHP, the SSI rate was 0.2%, whereas the probability of a WHP evolving toward a SSI was 100 times higher. The only factor significantly associated with a WHP becoming a SSI was osteosynthesis material exposure. DISCUSSION: This prospective study can be criticized on several points: the deliberately limited inclusion criteria, the short follow-up, and the possible subjectivity of the data collection. The SSI rates reported are for the most part in agreement with the literature. This study is innovative in traumatology given the large number of patients and the notion of WHP that was preferred over superficial infection. It demonstrates the relations between WHP and SSI, in particular for osteosyntheses near the skin. LEVEL OF EVIDENCE: Level III.

Trochanteric locking nail versus arthroplasty in unstable intertrochanteric fracture in patients aged over 75 years.

INTRODUCTION: In trochanteric fracture, whatever its anatomic type, internal fixation is currently the standard attitude, with arthroplasty as a relatively unusual option. HYPOTHESIS: Hip implants are an excellent alternative to osteosynthesis in unstable trochanteric fracture in patients aged over 75 years. PATIENTS AND METHODS: A non-randomised prospective multicenter study compared osteosynthesis by trochanteric nailing (n=113) to hip arthroplasty (n=134) in unstable trochanteric fracture (AO types 31 A2.2 and 3 and A3.3) in 247 patients over the age of 75 years. The series was recruited during 2007 in seven centres, four of which included only arthroplasties, two only osteosyntheses and one both. The two groups were comparable in age, sex, preoperative Parker score, pre-fracture place of residence, fracture type, time to surgery and preoperative comorbidity. The sole difference was in operators, with more senior surgeons in arthroplasty (62% versus 27%). RESULTS: Three-month mortality was identical in the two groups (21.2% versus 21%). General complications did not differ, although mechanical complications were more frequent in the nailing group (12.5% versus 2.8%). Functional results (Parker and PMA scores) were better in the implant than in the nail group. DISCUSSION: The present study validated hip arthroplasty in these indications. Cemented stems associated to a dual-mobility acetabular component gave the best results. TYPE OF STUDY: Prospective, level of evidence III.

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.

Optical spin orientation of a single manganese atom in a semiconductor quantum dot using quasiresonant photoexcitation.

An optical spin orientation is achieved for a Mn atom localized in a semiconductor quantum dot using quasiresonant excitation at zero magnetic field. Optically created spin-polarized carriers generate an energy splitting of the Mn spin and enable magnetic moment orientation controlled by the photon helicity and energy. The dynamics and the magnetic field dependence of the optical pumping mechanism show that the spin lifetime of an isolated Mn atom at zero magnetic field is controlled by a magnetic anisotropy induced by the built-in strain in the quantum dots.

[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.

[Right uncontrollable haemothorax revealing a liver injury with diaphragmatic rupture]. / Hémothorax droit intarissable révélateur d'une plaie hépatique avec rupture diaphragmatique.

We report a case of a woman with a blunt thoracic trauma and haemorrhagic shock after a road traffic accident. The clinical and complementary examinations revealed an isolated right haemothorax, which was compressive and uncontrollable. The source of bleeding was discovered with delay and during a surgical exploration: it was a liver injury with diaphragmatic rupture but without hepatic herniation and peritoneal effusion. The diagnostic features of blunt diaphragmatic rupture are discussed.