Non-linear QED approach for betatron radiation in a laser wakefield accelerator.

Laser plasma-based accelerators provide an excellent source of collimated, bright, and adequately coherent betatron-type x-ray pulses with potential applications in science and industry. So far the laser plasma-based betatron radiation has been described within the concept of classical Liénard-Wiechert potentials incorporated in particle-in-cell simulations, a computing power-demanding approach, especially for the case of multi-petawatt lasers. In this work, we describe the laser plasma-based generation of betatron radiation at the most fundamental level of quantum mechanics. In our approach, photon emission from the relativistic electrons in the plasma bubble is described within a nonlinear quantum electrodynamics (QED) framework. The reported QED-based betatron radiation results are in excellent agreement with similar results using Liénard-Wiechert potentials, as well as in very good agreement with betatron radiation measurements, obtained with multi-10-TW lasers interacting with He and multielectron N[Formula: see text] gas targets. Furthermore, our QED approach results in a dramatic reduction of the computational runtime demands, making it a favorable tool for designing betatron radiation experiments, especially in multi-petawatt laser facilities.

Nanowire implosion under laser amplified spontaneous emission pedestal irradiation.

Nanowire array targets exhibit high optical absorption when interacting with short, intense laser pulses. This leads to an increased yield in the production of accelerated particles for a variety of applications. However, these interactions are sensitive to the laser prepulse and could be significantly affected. Here, we show that an array of aligned nanowires is imploded when irradiated by an Amplified Spontaneous Emission pedestal of a [Formula: see text] laser with an intensity on the order of [Formula: see text]. Using radiation hydrodynamics simulations, we demonstrate that the electron density profile is radially compressed at the tip by the rocket-like propulsion of the ablated plasma. The mass density compression increases up to [Formula: see text] when a more dense nanowire array is used. This is due to the ablation pressure from the neighboring nanowires. These findings offer valuable information for selecting an appropriate target design for experiments aimed at enhancing production of accelerated particles.

Human cytomegalovirus-viruria in hematopoietic stem cell transplant recipients: Context and impact.

BACKGROUND: Episodes of CMV-viruria have been reported in hematopoietic stem cell transplant (HSCT) recipients, but their context of occurrence, pathophysiology, and clinical significance remain misunderstood. METHODS: Uurine samples from 517 recipients were collected. Clinical features of recipients with or without episodes of CMV-viruria were retrospectively compared. RESULTS: CMV-viruria was detected in 15.5 % of cases. Age, sex, type of transplantation, HLA-matching, conditioning regimen, and immunosuppressive therapies did not differ between patients with and without CMV-viruria. CMV-seropositive status (R + ) was more frequent among CMV-viruric recipients. Cumulated mortality did not differ between the two groups but graft-versus-host diseases occurred more frequently among CMV-viruric patients (p = 0.04). No reduction of the estimated glomerular filtration rates was observed in CMV-viruric recipients. CONCLUSIONS: CMV-viruria primarily occurs in CMV-seropositive recipients and is not related to the degree of immunosuppression. We suggest that CMV-viruria is primarily related to the inability of the graft immune system to contain CMV-replication in R + patients. CMV-viruria is not associated with increased mortality or renal dysfunction.

Letermovir breakthroughs during the French Named Patient Programme: interest of monitoring blood concentration in clinical practice.

OBJECTIVES: To analyse mechanisms of letermovir breakthrough during compassionate primary and secondary prophylaxis. METHODS: Mechanisms of letermovir breakthrough during compassionate primary and secondary prophylaxis were analysed in four patients from the French Named Patient Programme by the French National Reference Centre for Herpesviruses. RESULTS: Of three absolute resistance cases, two were associated with treatment interruption or low letermovir concentrations in blood. A fourth case of breakthrough was not associated with resistance. Next-generation sequencing (NGS) genotyping confirmed rapid emergence of resistant mutants, within 3 months of treatment initiation. CONCLUSIONS: Measurement of letermovir concentration and genotyping should be recommended for patient follow-up during letermovir therapy.

Combining Aspergillus mitochondrial and ribosomal QPCR, in addition to galactomannan assay, for early diagnosis of invasive aspergillosis in hematology patients.

The combination of two quantitative Aspergillus PCR assays, targeting a mitochondrial and a ribosomal target (AfQPCR), has proved effective for diagnosing invasive aspergillosis (IA) in hematology patients with risk factors and a positive galactomannan antigen (GM). The aim of the present study was to assess the performance of systematic AfQPCR for IA screening in at risk patients in a hematology intensive care unit (ICU). The study was performed in the hematology ICU at Besançon University Hospital from March 2012 to December 2013. GM detection (Platelia Aspergillus, Biorad, France) and AfQPCR were performed on the same serum sample, twice a week, in all patients with risk factors for IA. Risk factors and clinical, radiological, and biological data were prospectively recorded using the information sheet from the French network for the surveillance of Invasive Fungal Infection. Thirty-two patients were diagnosed with proven, probable, or possible IA according to the 2008 EORTC/MSG criteria. Sixteen patients had a positive AfQPCR: 9/16 had a positive GM at the same time (GM index >0.5), 4/16 had a positive GM before the AfQPCR and 3/16 had a negative GM at the time of the positive AfQPCR. Screening at risk patients using both AfQPCR and GM on the same serum sample is very feasible in a routine clinical setting. Our results confirm the usefulness of combining biomarkers for an early IA diagnosis.

[Prophylactic, preemptive and curative use of donor lymphocyte infusion in patients undergoing allogeneic stem cell transplantation: guidelines of the SFGM-TC]. / Recommandations de la SFGM-TC concernant l'injection prophylactique, préemptive et curative des lymphocytes du donneur (DLI) après allogreffe de cellules souches hématopoïétiques.

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the fourth annual series of workshops which brought together practitioners from all member centers and took place in September 2013 in Lille. Here, we report our recommendations regarding the use of donor lymphocyte injection (DLI) in the prophylactic, pre-emptive and curative settings. This work has been limited to allogeneic stem cell transplantations from an HLA-matched (10/10) or -one antigen-mismatched (9/10) donor.

Evaluation of invasive aspergillosis risk of immunocompromised patients alternatively hospitalized in hematology intensive care unit and at home.

UNLABELLED: Contrary to hospital exposure, little is known about the indoor fungal exposure of hematology patients at home. The aim of our study was to investigate the mold exposure of hematology patients both at home and at hospital to assess their invasive aspergillosis (IA) risk. Fungal exposure was assessed by quantifying opportunistic molds at hospital during hospitalization and in homes of 53 hematology patients. IA was diagnosed in 13 of 53 patients and invasive fungal infection (IFI) in one patient. In hospital, no opportunistic species, or low levels of opportunistic species, were found in 98% of weekly controls. Only 2% of hematology intensive care unit (ICU) controls showed a high level of Aspergillus fumigatus spores in corridor air. Five patients IA were hospitalized during these periods. Seven dwellings of 53 (5/14 dwellings of patients with IA/IFI and 2/39 dwellings of non-IA patients) had a percentage of A. fumigatus and Aspergillus flavus to total mold (significant predictor variable of IA/IFI in our study, general linear model, P-value = 0.02) as high as 15%. Maintaining a 'zero Aspergillus' goal at hospital is essential, and establishing specific and individually opportunistic mold monitoring at home could help to further reduce the IA risk through continuous surveillance. PRACTICAL IMPLICATIONS: This study emphasizes the fact that preventive measures should not be aimed only at the hospital setting: among patients diagnosed with invasive aspergillosis/invasive fungal infection (IA/IFI), 5 of 14 (36%) were exposed to opportunistic fungal species at home exclusively. Moreover, four of these five patients were living in homes having the highest percentage of Aspergillus fumigatus and Aspergillus flavus (>15%), one of which had 48% of A. fumigatus. Therefore, our work supports the need for a counselor to carry out an environmental survey in patients' homes.

[How I manage respiratory syncytial virus, human herpesvirus 6 and adenovirus reactivation or infection after allogeneic stem cell transplantation: a report of the SFGM-TC]. / Conduite à tenir devant une réactivation ou une infection à virus respiratoire syncytial, herpèsvirus 6 et adénovirus après allogreffe de cellules souches hématopoïétiques.

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the third annual series of workshops which brought together practitioners from all member centers and took place in October 2012 in Lille. Here we report our results and recommendations regarding the management of virus respiratory syncytial virus (RSV), human herpes virus 6 (HHV6) or adenovirus allogeneic Stem Cell Transplantation.

Drag in a resonantly driven polariton fluid.

We study the linear response of a coherently driven polariton fluid in the pump-only configuration scattering against a point-like defect and evaluate analytically the drag force exerted by the fluid on the defect. When the system is excited near the bottom of the lower polariton dispersion, the sign of the interaction-renormalised pump detuning classifies the collective excitation spectra into three different categories (Ciuti and Carusotto 2005 Phys. Status Solidi b 242 2224): linear for zero, diffusive-like for positive and gapped for negative detuning. We show that both cases of zero and positive detuning share a qualitatively similar crossover of the drag force from the subsonic to the supersonic regime as a function of the fluid velocity, with a critical velocity given by the speed of sound found for the linear regime. In contrast, for gapped spectra, we find that the critical velocity exceeds the speed of sound. In all cases, the residual drag force in the subcritical regime depends on the polariton lifetime only. Also, well below the critical velocity, the drag force varies linearly with the polariton lifetime, in agreement with previous work (Cancellieri et al 2010 Phys. Rev. B 82 224512), where the drag was determined numerically for a finite-size defect.

Double reduced-intensity allogeneic hematopoietic stem cell transplantation: a retrospective study from the SFGM-TC.

The purpose of this paper is to describe the outcome of patients who underwent double allogeneic hematopoietic stem cell transplantation (AHSCT) with reduced-intensity conditioning regimens (RIC). Forty-five patients who received double RIC-AHSCT between 1997 and 2006 were retrospectively studied. The predominant diagnosis was acute myeloid leukemia (AML) (n = 17). Other diagnoses were aplasic anemia (AA) (n = 5), myelodysplasic disorder (n = 5), acute lymphoblastic leukemia (ALL) (n = 4), chronic myelomonocytic leukemia (CML) (n = 3), myeloma (n = 3), non-Hodgkin lymphoma (NHL) (n = 3), chronic lymphocytic leukemia (CLL) (n = 2), Hodgkin's disease (HD) (n = 2), and chronic myelomonocytic leukemia (n = 1). Main indications for RIC-AHSCT 2 were relapse (n = 25, 56%) and early (n = 8, 18%) or late (n = 12, 26%) graft failure. Median delays to reach a neutrophil count of 0.5 × 10(9)/L and platelet counts of 50 × 10(9)/L were significantly smaller after the second AHSCT. Among 25 patients who relapsed after RIC-AHSCT 1, 14 patients (56%) presented a response improvement after RIC-AHSCT 2. In this group, 9 patients sustained a complete response and 5 patients a partial response. Moreover, among the 20 patients who had early or late graft failure following RIC-AHSCT 1, 9 (45%) finally reached an engraftment. Disease-free survival (DFS) was significantly improved after RIC-AHSCT 2. Thirteen patients (28%) died of transplant-related mortality (TRM) at a median delay of 69 days (range: 0-451) after RIC-AHSCT 2. Double RIC-AHSCT is a feasible procedure that allows a response or engraftment not observed after RIC-AHSCT 1. The main indication is relapse. However, TRM remains high.

Onset and dynamics of vortex-antivortex pairs in polariton optical parametric oscillator superfluids.

We study, both theoretically and experimentally, the occurrence of topological defects in polariton superfluids in the optical parametric oscillator (OPO) regime. We explain in terms of local supercurrents the deterministic behavior of both the onset and dynamics of vortex-antivortex pairs generated by perturbing the system with a pulsed probe. Using a generalized Gross-Pitaevskii equation, including photonic disorder, pumping and decay, we elucidate the reason why topological defects form in couples and can be detected by direct visualizations in multishot OPO experiments.

[Occurrence of severe, persistent thrombocytopenia following allogeneic bone marrow transplantation, attributable to anti-HPA-1 allo-immunisation of the host]. / Survenue d'une thrombopénie sévère et durable, au décours d'une greffe de moelle allogénique, imputable à l'existence chez l'hôte d'une allo-immunisation anti-HPA-1.

A 56 year-old, multiparous woman suffering from a myeloproliferative syndrome, who had received multiple red blood cell and platelet transfusions, was the recipient of an allograft of peripheral blood stem cells derived from her HLA-A, B, DR, DQ and DP and ABO identical sister, following myeloablative conditioning. The persistence of severe, isolated thrombopenia resistant to platelet transfusions led to the discovery of anti-HLA class I allo-immunisation. As HLA compatible platelet transfusions did not result in satisfactory platelet increments, we then discovered the simultaneous presence of anti-HPA-1a allo-immunisation. Genotyping of the HPA-1 systems of the patient (HPA-1B/B) and her sister (HPA-1A/B) enabled us to elucidate the mechanism underlying the persistent thrombopenia and the inefficacy of transfusion. In fact, only transfusion of HPA-1B/B platelets (HLA compatible or incompatible) proved to be efficacious. To reduce the level of anti-HPA-1a antibodies, we performed plasmapheresis sessions and used an anti-CD20 monoclonal antibody. It was only on achieving total haematopoietic chimerism, through rapid interruption of the immunosuppression, that we obtained spontaneous normalisation of the platelet count. The present case emphasises the necessity, before undertaking any allograft of haematopoietic stem cells - even if the latter come from a strictly HLA identical member of the family - of performing a search for eventual anti-HPA allo-immunisation.

Plasma renin activity (PRA) and plasma aldosterone in the adrenal cortex hyperactivity. Studies on 50 hypertensive patients.

The authors have studied on 50 patients hospitalized in the Adrenal Pathology unit of the Institute of Endocrinology, the etiopathogeny of arterial hypertension (AH) in hypercorticism and the therapeutic implications, arriving at the conclusion that in 20% of the cases AH was probably due to an increased activity of renin-angiotensin and in 47% to elevated levels of aldosterone. The authors hypothesize that AH in the remaining 30% of the hypercorticism cases in this study is due to other mineralocorticoids in excess and suggest that the treatment should be pathogenic and strictly individualized.

The role of the renin-angiotensin system in arterial hypertension in hypercorticism.

The authors have studied on 25 cases of hypercorticism, one of the mechanisms of producing arterial hypertension, the renin-angiotensin system. The study showed that in only 20% of the cases plasma renin activity was high whereas in the remaining 80% other mechanisms were responsible for the hypertension. In the cases in which the plasma activity of renin was high, by studying the changes in the value of electrolytes we were able to derive some understanding of the mechanism of action of the RA2A system. Thus, the literature data show that sometimes the excess of glucocorticoids causes hypertension by activating directly the RA2A system and concomitently inhibiting the renin-kalikrein system (RKKS) and PgS; at other times, the excess of glucocorticoids is exerted on the same renin-angiotensin system, but via ACTH and ADH, the electrolytes values being those that demonstrate the borrowed mechanism.