Full aperture backscatter diagnostics for characterization of laser plasma instabilities at the extreme light infrastructure (ELI) beamlines

We report on the commissioning of a full aperture backscatter diagnostics station for the kilojoule, nanosecond high repetition rate L4n laser operating at a wavelength of 527 nm at the Extreme Light Infrastructure (ELI) - Beamlines, Dolni Brezany, Czech Republic. Light scattered back from laser-plasma interaction into the cone of the final focusing lens is captured and split into different channels to measure the signatures of laser plasma instabilities from stimulated Brillouin scattering, stimulated Raman scattering, and two plasmon decay with respect to back scattered energy, its spectrum, and its temporal profile. The performance was confirmed in a commissioning experiment with more than 800 shots at laser intensities ranging from 0.5 × 1013 to 1.1 × 1015 W cm-2. These diagnostics are permanently installed at ELI Beamlines, and can be used to understand the details of laser-plasma interactions in experiments with kJ and 527 nm light. The large number of shots that can be collected in an experimental campaign will allow us to study the details of the laser-plasma interaction with a high level of confidence.

Swept-source optical coherence tomography microsystem with an integrated Mirau interferometer and electrothermal micro-scanner

In the rapid evolution of gastrointestinal endomicroscopy, optical coherence tomography (OCT) has found many diverse applications. Until recently, the micro-opto-electro-mechanical systems (MOEMS) technology has been playing a key role in shaping the miniaturization of these components. We report here, to the best of our knowledge, a novel endoscopic microsystem. It is based on a spectrally tuned MOEMS Mirau micro-interferometer integrated with micro-electro-mechanical systems (MEMS) electro-thermal micro-scanner, operating in the regime of swept-source (SS) OCT imaging. This Letter validates our initial proof-of-concept toward the development of such MOEMS probe and the presentation of experimental performances of the resulting SS-OCT microsystem.

Ultra-broadband EPR spectroscopy in field and frequency domains

Electron paramagnetic resonance (EPR) is a powerful technique to investigate the electronic and magnetic properties of a wide range of materials.

Matching DMFT calculations with photoemission spectra of heavy fermion insulators: universal properties of the near-gap spectra of SmB6

Paramagnetic heavy fermion insulators consist of fully occupied quasiparticle bands inherent to Fermi liquid theory. The gap emergence below a characteristic temperature is the ultimate sign of coherence for a many-body system, which in addition can induce a non-trivial band topology. Here, we demonstrate a simple and efficient method to compare a model study and an experimental result for heavy fermion insulators. The temperature dependence of the gap formation in both local moment and mixed valence regimes is captured within the dynamical mean field (DMFT) approximation to the periodic Anderson model (PAM). Using the topological coherence temperature as the scaling factor and choosing the input parameter set within the mixed valence regime, we can unambiguously link the theoretical energy scales to the experimental ones. As a particularly important result, we find improved consistency between the scaled DMFT density of states and the photoemission near-gap spectra of samarium hexaboride (SmB₆).

Direct 3D mapping of the Fermi surface and Fermi velocity

We performed a full mapping of the bulk electronic structure including the Fermi surface and Fermi-velocity distribution v_F(k_F) of tungsten. The 4D spectral function ρ(E_B; k) in the entire bulk Brillouin zone and 6 eV binding-energy (E_B) interval was acquired in ∼3 h thanks to a new multidimensional photoemission data-recording technique (combining full-field k-microscopy with time-of-flight parallel energy recording) and the high brilliance of the soft X-rays used. A direct comparison of bulk and surface spectral functions (taken at low photon energies) reveals a time-reversal-invariant surface state in a local bandgap in the (110)-projected bulk band structure. The surface state connects hole and electron pockets that would otherwise be separated by an indirect local bandgap. We confirmed its Dirac-like spin texture by spin-filtered momentum imaging. The measured 4D data array enables extraction of the 3D dispersion of all bands, all energy isosurfaces, electron velocities, hole or electron conductivity, effective mass and inner potential by simple algorithms without approximations. The high-Z bcc metals with large spin-orbit-induced bandgaps are discussed as candidates for topologically non-trivial surface states.

Low-dose interleukin-2 promotes STAT-5 phosphorylation, Treg survival and CTLA-4-dependent function in autoimmune liver diseases

CD4⁺CD25^highCD127^lowforkhead box protein 3 (FoxP3⁺) regulatory T cells (T_reg) are essential for the maintenance of peripheral tolerance. Impaired T_reg function and an imbalance between effector and T_regs contribute to the pathogenesis of autoimmune diseases. We reported recently that the hepatic microenvironment is deficient in interleukin (IL)−2, a cytokine essential for T_reg survival and function. Consequently, few liver‐infiltrating T_reg demonstrate signal transducer and activator of transcription‐5 (STAT‐5) phosphorylation. To establish the potential of IL‐2 to enhance T_reg therapy, we investigated the effects of very low dose Proleukin (VLDP) on the phosphorylation of STAT‐5 and the subsequent survival and function of T_reg and T effector cells from the blood and livers of patients with autoimmune liver diseases. VLDP, at less than 5 IU/ml, resulted in selective phosphorylation of STAT‐5 in T_reg but not effector T cells or natural killer cells and associated with increased expression of cytotoxic T lymphocyte antigen‐4 (CTLA‐4), FoxP3 and CD25 and the anti‐apoptotic protein Bcl‐2 in T_reg with the greatest enhancement of regulatory phenotype in the effector memory T_reg population. VLDP also maintained expression of the liver‐homing chemokine receptor CXCR3. VLDP enhanced T_reg function in a CTLA‐4‐dependent manner. These findings open new avenues for future VLDP cytokine therapy alone or in combination with clinical grade T_reg in autoimmune liver diseases, as VLDP could not only enhance regulatory phenotype and functional property but also the survival of intrahepatic T_reg.

Cytogenetics and outcome of allogeneic transplantation in first remission of acute myeloid leukemia: the French pediatric experience

We analyzed the impact of cytogenetics on 193 children enrolled in two successive French trials (LAME89/91 and ELAM02), who received hematopoietic stem cell transplantation during CR1. Detailed karyotype was available for 66/74 (89%) in LAME89/91 and 118/119 (99%) in ELAM02. Several karyotype and transplant characteristics differed according to therapeutic protocol: unfavorable karyotypes were more frequent in ELAM02 (36% vs 18%), pretransplant chemotherapy included high-dose cytarabine in ELAM02 and not in LAME89/91, IV replaced oral busulfan in the conditioning regimen, methotrexate was removed from post-transplant immunosuppression, and matched unrelated donor and cord blood transplantation were introduced. Five-year overall survival (OS) was 78.2% in LAME89 and 81.4% in ELAM02. OS was significantly lower for the unfavorable cytogenetic risk group in LAME89/91 when compared with intermediate and favorable groups (50% vs 90.6 and 86.4%, P=0.001). This difference was no longer apparent in ELAM02 (80.9% vs 71.3% and 5/5, respectively). Survival improvement for children with unfavorable karyotype was statistically significant (P=0.026) and was due to decrease in relapse risk. Five-year transplantation-related mortality was 6.75% in LAME89/91. In ELAM02, it was 3.2% for patients with a sibling donor and 10.9% with an unrelated donor or cord blood. We conclude that the outcome of children with unfavorable karyotype transplanted in CR1 has improved.

Combined therapy in children and adolescents with classical Hodgkin's lymphoma: A report from the SFCE on MDH-03 national guidelines

Hodgkin's lymphoma (HL) in children and adolescents is highly curable, but children are at risk of long-term toxicity. The MDH-03 guidelines were established in order to decrease the burden of treatment in good-responder patients, and this report should be considered a step toward further optimization of treatment within large collaborative trials. We report the therapy and long-term outcomes of 417 children and adolescents treated according to the national guidelines, which were applied between 2003 and 2007 in France. The patients were stratified into three groups according to disease extension. Chemotherapy consisted of four cycles of VBVP (vinblastine, bleomycin, VP16, prednisone) in localized stages (G1/95 pts/23%), four cycles of COPP/ABV (cyclophosphamide, vincristine, procarbazine, prednisone, adriamycin, bleomycin, vinblastine) cycles in intermediate stages (G2/184 pts/44%) and three cycles of OPPA (vincristine, procarbazine, prednisone, adriamycin) plus three cycles of COPP in advanced stages (G3/138 pts/33%). Radiation therapy of the involved field was given to 97% of the patients, with the dose limited to 20 Gy in good responders (88%). With a median follow-up of 6.6 years, the 5-year event-free survival (EFS) and overall survival (OS) were 86.7% (83.1-89.7%) and 97% (94.5-98.1%), respectively. EFS and OS for G1, G2, and G3 were 98% and 100%, 81% and 97%, and 87% and 95%, respectively. Low-risk patients treated without alkylating agents and anthracycline had excellent outcomes and a low expected incidence of late effects. Intensification with a third OPPA cycle in high-risk group patients, including stage IV patients, allowed for very good outcomes, without increased toxicity.

Prevalence and risk factors of iron overload after hematopoietic stem cell transplantation for childhood acute leukemia: a LEA study

Data on post-transplant iron overload (IO) are scarce in pediatrics. We conducted a prospective multicenter cohort study (Leucémie de l'Enfant et de l'Adolescent cohort) to determine the prevalence and risk factors of IO in 384 acute leukemia survivors transplanted during childhood. Prevalence of IO (ferritin level ⩾350 ng/mL) was 42.2% (95%CI 37.2-47.2%). Factors significantly associated with IO were: 1) in univariate analysis: older age at transplant (P<0.001), allogeneic versus autologous transplantation (P<0.001), radiation-based preparative regimen (P=0.035) and recent period of transplantation (P<0.001); 2) in multivariate analysis: older age at transplant in quartiles (Odds Ratio (OR)=7.64, 95% CI: 3.73-15.64 for age >12.7 years and OR=5.36, 95% CI: 2.63-10.95 for age from 8.2 to 12.7 years compared to age < 4.7 years), acute myeloid leukemia (OR=3.23, 95% CI: 1.47-7.13), allogeneic graft (OR=4.34, 95% CI: 2.07-9.12 for alternative donors and OR=2.53, 95% CI: 1.2-5.33 for siblings, compared to autologous graft) and radiation-based conditioning regimen (OR=2.45, 95% CI: 1.09-5.53). Graft-versus-host disease was an additional risk factor for allogeneic graft recipients. In conclusion, IO is a frequent complication in pediatric long-term survivors after transplantation for acute leukemia, more frequently observed in older children, those transplanted from alternative donors or with graft-versus-host disease.

[Pediatric medulloblastoma: Retrospective series of 52 patients]

PURPOSE

Retrospective analysis of the results of 52 children irradiated for a medulloblastoma.

PATIENTS AND METHODS

Between 1974 and 2012, 52 children with an average age of 6 years and a half (11 months-17 years and a half) were treated with surgery then with radiotherapy at the Comprehensive Cancer Centre of Strasbourg (France). For 44 children, the treatment consisted of a chemotherapy.

RESULTS

After a mean follow-up of 106.6 months (7-446 months), 13 relapses and 24 deaths were observed. Overall survival at 5 years and 10 years were 62% and 57%, respectively. Disease-free survival at 5 years and 10 years were 80% and 63%, respectively. Univariate analysis found the following adverse prognostic factors: the existence of a postoperative residue, the positivity of the cerebrospinal fluid, the metastatic status and medulloblastoma of high-risk. Positivity of the cerebrospinal fluid remains a negative factor in multivariate analysis.

CONCLUSION

These results confirm the survival rate obtained by a conventional approach (surgery then irradiation). Insufficiency of results and rarity of medulloblastoma require the establishment of international protocols.

Electrical resistivity tomography to quantify in situ liquid content in a full-scale dry anaerobic digestion reactor

The electrical resistivity tomography (ERT) method is a non-intrusive method widely used in landfills to detect and locate liquid content. An experimental set-up was performed on a dry batch anaerobic digestion reactor to investigate liquid repartition in process and to map spatial distribution of inoculum. Two array electrodes were used: pole-dipole and gradient arrays. A technical adaptation of ERT method was necessary. Measured resistivity data were inverted and modeled by RES2DINV software to get resistivity sections. Continuous calibration along resistivity section was necessary to understand data involving sampling and physicochemical analysis. Samples were analyzed performing both biochemical methane potential and fiber quantification. Correlations were established between the protocol of reactor preparation, resistivity values, liquid content, methane potential and fiber content representing liquid repartition, high methane potential zones and degradations zones. ERT method showed a strong relevance to monitor and to optimize the dry batch anaerobic digestion process.

[Evolution of the management of pediatric and adult medulloblastoma]

Medulloblastoma are cerebellar tumours belonging to the group of primitive neuroectodermal tumours (PNET) and are the most common malignant brain tumours of childhood. These tumours are rare and heterogeneous, requiring some multicentric prospective studies and multidisciplinary care. The classical therapeutic approaches are based on clinical, radiological and surgical data. They involve surgery, radiation therapy and chemotherapy. Some histological features were added to characterize risk. More recently, molecular knowledge has allowed to devise risk-adapted strategies and helped to define groups with good outcome and reduce long-term sequelae, improve the prognostic of high-risk medulloblastoma and develop new therapeutic tools.

Importance of charge fluctuations for the topological phase in SmB(6)

Typical Kondo insulators (KIs) can have a nontrivial Z_{2} topology because the energy gap opens at the Fermi energy (E_{F}) by a hybridization between odd- and even-parity bands. SmB_{6} deviates from such KI behavior, and it has been unclear how the insulating phase occurs. Here, we demonstrate that charge fluctuations are the origin of the topological insulating phase in SmB_{6}. Our angle-resolved photoemission spectroscopy results reveal that with decreasing temperature the bottom of the d-f hybridized band at the X[over ¯] point, which is predicted to have odd parity and is required for a topological phase, gradually shifts from below to above E_{F}. We conclude that SmB_{6} is a charge-fluctuating topological insulator.

[General anesthesia in pediatric radiotherapy]

BACKGROUND

The majority of children under 3 years require anesthesia for radiotherapy.

METHODS

This work reports the experience of Paul-Strauss Center over a 4-year period on 15 children and covering 386 general anesthesia.

RESULTS AND CONCLUSION

The rate of anesthesia-related complications was low (0.5%) subject to the experience of the anesthesiologists and follow-up recommendations.

Multidirectional transparent support for overground gait training

Gait and balance training is an essential ingredient for locomotor rehabilitation of patients with neurological impairments. Robotic overhead support systems may help these patients train, for example by relieving them of part of their body weight. However, there are only very few systems that provide support during overground gait, and these suffer from limited degrees of freedom and/or undesired interaction forces due to uncompensated robot dynamics, namely inertia. Here, we suggest a novel mechanical concept that is based on cable robot technology and that allows three-dimensional gait training while reducing apparent robot dynamics to a minimum. The solution does not suffer from the conventional drawback of cable robots, which is a limited workspace. Instead, displaceable deflection units follow the human subject above a large walking area. These deflection units are not actuated, instead they are implicitly displaced by means of the forces in the cables they deflect. This leads to an underactuated design, because the deflection units cannot be moved arbitrarily. However, the design still allows accurate control of a three-dimensional force vector acting on a human subject during gait. We describe the mechanical concept, the control concept, and we show first experimental results obtained with the device, including the force control performance during robot-supported overground gait of five human subjects without motor impairments.

[Diet of neutropenic patients in pediatric oncology service; the experience of the university hospital of Strasbourg (HUS)]

OBJECTIVE

This article clarifies the choices made by the HUS concerning the ways of preparing food reserved to neutropenic children hospitalized in pediatric oncology service. We will describe the results of microbiological analysis of food realized from 2002 to 2007.

METHODS

A specific team prepares this food which is canned and treated by "appertisation" (autoclaving). Each dish portion produced is provided to the service only if the microbiological results are conform, that is to say free of organisms.

RESULTS

Three thousand and seventy-eight dishes were analysed: 82.9% of the analysed packs were conform. The contamination ratio decreased significantly (P<0.001) from 2002 to 2007. The organisms which cause the majority of dishes contamination are Bacillus (44.7%) and environmental mould exhibiting sterile mycelium (8.7%). The food which is the most frequently "nonconform" is the dry food with a contamination rate of 37.9%. The identified concentrations remain mainly lower than 50 colony-forming units per millilitre (CFU/mL): 66.2% for the bacteria and 97.2% for the fungi.

CONCLUSION

Considering the lack of consensus on the acceptable microbiological thresholds and on the food protection level, the HUS make it a rule to have a maximal precautionary principle. Currently, this principle appears to us to be a safety option required for the patients hospitalized in pediatric oncology service.

Progression of liver fibrosis in HIV/HCV genotype 1 co-infected patients is related to the T allele of the rs12979860 polymorphism of the IL28B gene

OBJECTIVE

HIV/HCV co-infection is characterised by accelerated progression of liver disease. Recently, the rs12979860 C/T polymorphism in the IL28B gene has been linked to progression towards cirrhosis in HCV mono-infected patients and to treatment response of HCV-infection in HIV/HCV co-infected patients. Our aim was to clarify by non-invasive techniques if this polymorphism affects fibrosis progression in HIV/HCV co-infection.

METHODS

In a cross-sectional design, liver stiffness (transient elastography), surrogate markers of liver fibrosis (APRI and FIB-4 scores) and rs12979860 genotypes were analysed in 84 HCV/HIV co-infected patients. IL28B genotypes were determined by real-time PCR using a light cycler. In 56 HIV/HCV co-infected patients we also studied progression of fibrosis in relation to rs12979860 C/T genotypes over two years.

RESULTS

82% of the patients were on HAART (74% without detectable HI viremia) and 67% were haemophiliacs, respectively. HCV genotype 1 was present in 62%. Cross-sectional median liver stiffness was 7.4 kPa and correlated with APRI and FIB-4 scores (r = 0.6 each, p < 0.001). Frequencies of IL28B genotypes were: CC 50%, CT 43% and TT 7%. In the cross-sectional analysis liver stiffness values were not different between the various IL28B-genotypes. Upon follow-up under HAART carriers of a C allele did not show further progression, while liver stiffness significantly increased in HIV/HCV co-infected patients with the T allele (p = 0.047).

CONCLUSION

Although progression of liver fibrosis was low under HAART in our cohort, progression was more pronounced in HIV/HCV genotype 1 co-infected patients with the T allele.

[French guidelines. Long-term prophylaxis for severe haemophilia A and B children to prevent haemophiliac arthropathy]

During the last decades, long-term prophylaxis has become the gold standard for the treatment of children with severe haemophilia A or B. Prophylactic replacement regimens modify the natural history of the disease by aiming at the prevention of haemarthrosis, target joints and arthropathy. This treatment represents a constraint and an enhanced exposure to anti-haemophilic concentrates, which means potential increase of related risks and significant additional cost. The context of crisis of confidence due to the blood borne infections in the 1980s, may have delayed prophylaxis as an universal gold standard.In the early 2000s, the French group CoMETH proposed recommendations based on the review of the international experience. At first, specific guidelines of long-term prophylaxis were dedicated to children with severe haemophilia A or B, aged 3 years or less, with no history of target joint or arthropathy. The main concerns of this regimen consist in the early start and the escalating intensification of the treatment. In the French haemophilia care centres, the diffusion of these guidelines has apparently induced a significant turning point in therapeutic practices for haemophilia children. In 2006, more comprehensive recommendations were diffused to take into account all the children with severe haemophilia, whatever the bleeding history and joint status. The analysis of their impact, jointly with the National cohort "France Coag Network", will first assess the widespread implementation of the recommendations and the observance of the prophylactic regimen and identify factors associated to the compliance.

Outcome of an adult granulosa cell tumour in an adolescent initially managed by laparoscopy

Adult granulosa cell tumour is rarely encountered in adolescents. Tumours in their early stages have a favourable prognosis whereas those in advanced stages have a poor outcome. Documented series of tumours at advanced stages are very rare and follow-up is difficult because of the frequently prolonged intervals before progression of the tumour. That may explain why it is very difficult to define a consensual management strategy with or without adjuvant therapy such as chemotherapy or radiation therapy. We describe a case of adult granulosa cell tumour in a 14-year-old girl who initially underwent laparoscopy for an "unsuspicious" cyst. Management was then modified according to oncological guidelines because of the histological nature of this cyst.