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We present a broad study of linear, clustered, noble gas puffs irradiated with the frequency doubled (527 nm) Titan laser at Lawrence Livermore National Laboratory. Pure Ar, Kr, and Xe clustered gas puffs, as well as two mixed-gas puffs consisting of KrAr and XeKrAr gases, make up the targets. Characterization experiments to determine gas-puff density show that varying the experimental parameter gas-delay timing (the delay between gas puff initialization and laser-gas-puff interaction) provides a simple control over the gas-puff density. X-ray emission (>1.4 keV) is studied as a function of gas composition, density, and delay timing. Xe gas puffs produce the strongest peak radiation in the several keV spectral region. The emitted radiation was found to be anisotropic, with smaller X-ray flux observed in the direction perpendicular to both laser beam propagation and polarization directions. The degree of anisotropy is independent of gas target type but increases with photon energy. X-ray spectroscopic measurements estimate plasma parameters and highlight their difference with previous studies. Electron beams with energy in excess of 72 keV are present in the noble gas-puff plasmas and results indicate that Ar plays a key role in their production. A drastic increase in harder X-ray emissions (X-ray flash effect) and multi-MeV electron-beam generation from Xe gas-puff plasma occurred when the laser beam was focused on the front edge of the linear gas puff.
Background: SMA is a neurodegenerative disease caused by biallelic deletion/mutation of the survival motor neuron (SMN1) gene. In the phase 1 trial (NCT02122952), SMN GRT onasemnogene abeparvovec (AVXS-101) improved outcomes of 15 symptomatic SMA1 patients (3 at a lower dose [cohort 1] and 12 at the proposed therapeutic dose [cohort 2]). This report describes long-term follow-up study design and data from the phase 1 study. Methods: Patients in the phase 1 study could rollover into a long-term follow-up study (NCT03421977). The primary objective is to collect long-term safety data (serious adverse events, hospitalizations, and adverse events of special interest). Annual follow-up will occur for 15 years. Additionally, patient record transfers from local clinician(s) will be requested. Safety assessments include medical history and record review, physical examination, clinical laboratory evaluation, and pulmonary assessments. Efficacy assessments include physical examination to assess developmental milestones. Results: As of September 27, 2018, the oldest patients are 59.2 (cohort 1) and 52.1 (cohort 2) months old and free of permanent ventilation. Preliminary data, including survival and developmental milestones, will be presented. Conclusions: Patients treated with a one-time dose of AVXS-101 continue to gain strength, develop, and achieve new milestones, demonstrating a long-term, durable response.
Background: SMA is a neurodegenerative disease caused by biallelic deletion/mutation of SMN1. Copies of a similar gene (SMN2) modify disease severity. In a phase 1 study, SMN GRT onasemnogene abeparvovec (AVXS-101) improved outcomes of symptomatic SMA patients with two SMN2 copies (2xSMN2) dosed ≤6 months. Because motor neuron loss can be insidious and disease progression is rapid, early intervention is critical. This study evaluates AVXS-101 in presymptomatic SMA newborns. Methods: SPR1NT is a multicenter, open-label, phase 3 study enrolling ≥27 SMA patients with 2–3xSMN2. Asymptomatic infants ≤6 weeks receive a one-time intravenous AVXS-101 infusion (1.1x1014 vg/kg). Safety and efficacy are assessed through study end (18 [2xSMN2] or 24 months [3xSMN2]). Primary outcomes: independent sitting for ≥30 seconds (18 months [2xSMN2]) or assisted standing (24 months [3xSMN2]). Results: From April–September 2018, 7 infants received AVXS-101 (4 female; 6 with 2xSMN2) at ages 8–37 days. Mean baseline CHOP-INTEND score was 41.7 (n=6), which increased by 6.8, 11.0, 18.0, and 22.5 points at day 14 (n=4), month 1 (n=3), 2 (n=3), and 3 (n=2). Updated data available at the time of the congress will be presented. Conclusions: Preliminary data from SPR1NT show rapid motor function improvements in presymptomatic SMA patients.
A recent goal of the ANL Intense Pulsed Neutron Source (IPNS) has been the fabrication of a new enriched uranium target with increased neutron flux (by a factor of 3) which is dimensionally stable under irradiation. Neutron diffraction, using several instruments both at IPNS and MURR, has been used as a probe to characterize the target material vith respect to grain size and preferred orientation. The samples studied were portions of the uranium discs (4" diameter X 1/2" thick) which, when stacked, form the target assembly at IPNS. The old target discs were fabricated as slices from a fast cooled casting (arc-melted, water cooled in a cylindrical mold) and possess small grain size and negligible orientation. The new enriched target discs, on the other hand, are being fabricated from a slow cooled material (graphite book-mold, natural cooling) and, prior to additional treatment, have a large grain size and a high degree of preferred orientation which could produce dimensional changes during fission as the target is used. Our conclusion from this investigation is that a β-phase heat treatment (quench from 730°C) is necessary to produce a finer grain and more nearly random texture in thg new enriched material. Based on our detailed texture measurements the anticipated target lifetime of several years appears feasible.
Introduction / Innovation Concept: Acute care skills are difficult to teach but can be improved using high-fidelity simulation training. We developed a comprehensive acute care “Nightmares-FM” simulation course (NM) for our Family Medicine residents and compared it to our standard simulation teaching- episodic Acute Care Rounds (ACR). Methods: NM course consisted of an initial 2 day session followed by 3 follow-on sessions interspersed throughout the PGY-1 year. ACR participants got access to 3 sessions interspersed throughout the PGY-1 year, each focusing on a different aspect of acute care. Both groups got access to the NM manual which covered the relevant topics: shock, arrhythmias, shortness of breath, altered level of consciousness and myocardial infarction. The manual is physiology-based and written specifically at the level that an average Family Medicine resident would be expected to perform at during on-call crises or emergency medicine rotations. 12 residents participating in the NM and 12 residents in time-matched ACR filled out questionnaires asking them to rate their level of knowledge of various aspects of acute care. Self-reported changes before and after each session, and at the end of the year, were analyzed using Wilcoxon matched pairs test. End of the year mean scores were compared using a two sided t-test. Finally, we developed a high-complexity acute care Objective Structured Clinical Examination (OSCE): COPD exacerbation with septic shock requiring use of positive pressure ventilation, fluids and vasopressors. The groups participated in the OSCE in February of their PGY-2 year and were graded using a validated scoring sheet marked by two independent expert video reviewers. Curriculum, Tool, or Material: NM initial 2-day session significantly improved the resident’s self-assessment scores on all 20 items of the questionnaire (p<0.05). Time matched ACR improved 11 out of 20 items (p<0.05) level. Follow-up NM sessions improved 5-8 out of 20 items, (p<0.05). Follow-up ACR sessions improved 1-5 out of 20 items, (p<0.05). End of the year means were higher for 13/20 items in the NM group (p>0.05) The NM group scored significantly higher on both the mean scores of OSCE individual categories: Initial assessment, Diagnostic workup, Therapeutic interventions and Communication and teamwork (p<0.05) and the Global Assessment Score (p<0.026). Conclusion: “Nightmares-FM” course is more effective than our standard curriculum at teaching acute care skills to Family Medicine residents.
During the period, there have been several major events which have effected the scope and interest of Commission 19. The most significant of these has been the dissolution of the BIH and IPMS and their replacement by the International Earth Rotation Service (IERS). The correlation of higher frequency fluctuations in the Earth’s rotation rate with changes in the Earth’s Atmospheric Angular Momentum is also significant. Many investigators now seem to believe that the “decade variations„ in the Earth’s rotation rate are caused by torques between the core and mantle caused by the uneven motions at the core-mantle boundary. These events and discoveries have made this an exciting period. It seems that the future holds more in the way of discovery due to the utilization of the more accurate and precise Earth rotation data coming from the modern observing techniques.
Norovirus outbreaks occur frequently in Denmark and it can be difficult to establish whether apparently independent outbreaks have the same origin. Here we report on six outbreaks linked to frozen raspberries, investigated separately over a period of 3 months. Norovirus from stools were sequence-typed; including extended sequencing of 1138 bp encompassing the hypervariable P2 region of the capsid gene. Norovirus was detected in 27 stool samples. Genotyping showed genotype GI.Pb_GI.6 (polymerase/capsid) with 100% identical sequences. Samples from five outbreaks were furthermore identical over the variable capsid P2 region. In one outbreak at a hospital canteen, frozen raspberries was associated with illness by cohort investigation (relative risk 6·1, 95% confidence interval 3·2–11). Bags of raspberries suspected to be the source were positive for genogroup I and II noroviruses, one typable virus was genotype GI.6 (capsid). These molecular investigations showed that the apparently independent outbreaks were the result of one contamination event of frozen raspberries. The contaminated raspberries originated from a single producer in Serbia and were originally not considered to belong to the same batch. The outbreaks led to consultations and mutual visits between producers, investigators and authorities. Further, Danish legislation was changed to make heat-treatment of frozen raspberries compulsory in professional catering establishments.
Gallium Nitride (GaN) thin films were successfully grown by electron cyclotron resonance molecular beam epitaxy (ECR-MBE), gas source MBE (GSMBE), and chemical beam epitaxy (CBE). Time of flight mass spectroscopy of recoiled ions (TOF-MSRI) and reflection high energy electron diffraction (RHEED) were used in-situ to determine the surface composition, crystalline structure, and growth mode of GaN thin films deposited by the three MBE methods. The substrate nitridation and the buffer layers were monitored and optimized by TOF-MSRI and RHEED. For GSMBE, the gallium to nitrogen ratio is found to correlate well with ex-situ optical properties. In the case of CBE, carbon incorporation determines the surface morphology, crystalline quality and optical activity of the epilayers.
Recent studies have provided strong evidence that variation in the gene neurocan (NCAN, rs1064395) is a common risk factor for bipolar disorder (BD) and schizophrenia. However, the possible relevance of NCAN variation to disease mechanisms in the human brain has not yet been explored. Thus, to identify a putative pathomechanism, we tested whether the risk allele has an influence on cortical thickness and folding in a well-characterized sample of patients with schizophrenia and healthy controls.
Sixty-three patients and 65 controls underwent T1-weighted magnetic resonance imaging (MRI) and were genotyped for the single nucleotide polymorphism (SNP) rs1064395. Folding and thickness were analysed on a node-by-node basis using a surface-based approach (FreeSurfer).
In patients, NCAN risk status (defined by AA and AG carriers) was found to be associated with higher folding in the right lateral occipital region and at a trend level for the left dorsolateral prefrontal cortex. Controls did not show any association (p > 0.05). For cortical thickness, there was no significant effect in either patients or controls.
This study is the first to describe an effect of the NCAN risk variant on brain structure. Our data show that the NCAN risk allele influences cortical folding in the occipital and prefrontal cortex, which may establish disease susceptibility during neurodevelopment. The findings suggest that NCAN is involved in visual processing and top-down cognitive functioning. Both major cognitive processes are known to be disturbed in schizophrenia. Moreover, our study reveals new evidence for a specific genetic influence on local cortical folding in schizophrenia.
We investigated the suitability of powder metallurgy as well as die casting for the fabrication of light-weight Al-based composites with quasicrystalline particles embedded in an aluminum matrix. Al-Mn-Ce and Al-Cu-Fe quasicrystalline powders were synthesized by milling of elemental powder mixtures or arc-melted prealloys using a planetary ball mill. The mixture of the quasicrystalline phase and the Al-matrix phase with an appropriate ratio was realized by an initial aluminum excess or by blending of quasicrystalline powder with pure aluminum. The powders were consolidated by hot extrusion. Bulk samples of Ø3mm diameter and 50mm length were also directly prepared by squeezing the melt into a copper mold. CCRT-compression tests revealed a yield strength of about 400 MPa, an ultimate strength of 565 MPa and a ductility of up to 19 % fracture strain as optimum mechanical properties.
The syntheses and physical properties of K-(ET)2CU[N(CN)2]X (X = Br and Cl) are summarized. The K-(ET)2Cu [N(CN)2] Br salt is the highest Tc radical-cation based ambient pressure organic superconductor (Tc = 11.6 K), and the K-(ET)2CU [N(CN)2] C1 salt becomes a superconductor at even higher Tc under 0.3 kbar hydrostatic pressure (Tc = 12.8 K). The similarities and differences between K-(ET)2Cu[N(CN)2]Br and K-(ET)2CU(NCS)2 (TC = 10.4 K) are presented. The X-ray structures at 127 K reveal that the S-S contacts shorten between ET dimers in the former compound while the S-S contacts shorten within dimers in the latter. The differences in their ESR linewidth behavior is also explained in terms of the structural differences. A semiconducting compound, (ET)Cu[N(CN)2]2, isolated during K-(ET)2Cu[N(CN)2]Cl synthesis is also reported. The ESR measurements of the K-(ET)2Cu[N(CN)2]Cl salt indicate that the phase transition near 40 K is similar to the spin density wave transition in (TMTSF)2SbF6. A new class of organic superconductors, K-(ET)2CU2(CN)3 and K-(ET)2Cu2(CN)3.δBrδ, is reported with Tc's of 2.8 K (1.5 kbar) and 2.6 K (1 kbar), respectively.
This study relates the microstructure of equiatomic binary alloys of CoPt and FePt with their room-temperature hysteretic magnetic properties, particularly their high coercivity. A transformation from an atomically disordered, face-centered-cubic structure to the Li0 ordered structure occurred during post-deposition annealing and was characterized using digital analysis of dark-field transmission electron microscopy (TEM) images. The transformation was observed to follow first-order nucleation and growth kinetics, and the ordered volume fraction transformed was quantified at numerous points during the transformation. The ordered volume fraction was then compared to the magnetic coercivity data obtained from a superconducting quantum interference device (SQUID) magnetometer. Although the relationship most commonly described in the literature is that the highest coercivity corresponds to a two phase ordered/disordered mixture, the maximum value for coercivity in this study was found to correspond to the fully ordered state. Furthermore, in samples that were less than fully ordered, a direct relationship between ordered volume fraction and coercivity was observed. The proposed mechanism for the high coercivity in these films is an increasing density of magnetic domain wall pinning sites concurrent with an increasing fraction of ordered phase.
Recent aspects of hydrogenation disproportionation desorption and recombination (HDDR) phenomena in NdFeB-, SmFe- and SmCo-type alloys are reviewed in this paper. The effects of additives on hydrogen sorption and magnetic properties are discussed. The possibilities of producing magnetically anisotropic NdFeB HDDR magnets by hot deformation or alternatively pre-aligning and compacting anisotropic powders are described. Current models for the inducement of magnetic anisotropy in NdFeB HDDR powder are summarized and it is shown that anisotropic powder can be produced from a ternary compound when using a modified processing route. The application of ‘extreme’ hydrogenation conditions, namely high hydrogen pressure or reactive milling in a hydrogen atmosphere at enhanced temperatures, allows the disproportionation of thermodynamically very stable compounds such as Sm2Fe17−xGax (x≥l), SmCo5 or Sm2Co17. Reactive milling and subsequent recombination in vacuum lead to structures, of both the disproportionated and the recombined type, which are on a remarkably finer scale than those commonly observed for standard HDDR procedures. Exchange coupling between the nano-scaled grains can result in magnetically single phase behavior despite a multiphase microstructure and in particular for the Sm2Co17 alloy, a remanence enhancement was observed after recombination at temperatures ≤700°C.
Thin film CoPt/Co bilayers have been prepared as a model system to investigate the relationship between microstructure and exchange coupling in two-phase hard/soft composite magnets. CoPt films, with a thickness of 25 nm, were sputter-deposited from a nearly equiatomic alloy target onto oxidized Si wafers. The films were subsequently annealed at 700°C and fully transformed from the FCC phase to the magnetically hard, ordered L1 0 phase. The coercivity of the films increased rapidly with annealing time until it reached a plateau at approximately 9.5 kOe. Fully-ordered CoPt films were then used as substrates for deposition of Co layers, with thicknesses in the range of 2.8-225 nm, in order to produce the hard/soft composite bilayers. As predicted by theory, the magnetic coherency between the soft Co phase and the hard, ordered CoPt phase decreased as the thickness of the soft phase increased. This decrease in coupling was clearly seen in the magnetic hysteresis loops of the bilayers. At small thicknesses of Co (a few nanometers), the shape of the loop was one of a uniform material showing no indication of the presence of two phases with extremely different coercivities. At larger Co thicknesses, constricted loops, i.e., ones showing the presence of a mixture of two ferromagnetic phases of different hardnesses, were obtained. The magnetic exchange present in the bilayer samples was qualitatively analyzed using magnetic recoil curves and the dependence of exchange coupling on the soft phase dimension in the bilayer hard/soft composite magnet films is discussed.
The nanocrystallization processes in Fe-Si-B-Nb-Cu and Fe-Nd-B(-Cu-Nb) amorphous alloys have been studied by transmission electron microscopy (TEM) and a three dimensional atom probe (3DAP). Cu additions are effective in refining the nanocrystalline microstructures of both alloys, because Cu atom clusters formed prior to the crystallization reaction serve as heterogeneous nucleation sites for the primary crystals. However, the clustering behaviors of Cu atoms in these two alloy systems are different, i.e., Cu completely dissolves in the Nd2Fe1 4B phase in the final microstructure of the Nd4.5Fe75.8B18.5Cu0.2Nb1 alloy, whereas CL' clusters grow to fcc-Cu particles in the Fe73.5Si13.5B9Nb3Cu1 alloy. The nanocrystallization processes in these two alloys clarified by the 3DAP results are compared.
SmFe based alloys interstitially modified with nitrogen are potential candidates for high energy permanent magnets. In order to obtain the optimum properties a thorough understanding of the starting material and processing parameters is required. The microstructures of two cast alloys of composition Sm13.8Fe82.2 Ta4.0 and Sm13.7 Fe86.3 were carefully examined with a SEM equipped with EDX and the exact stoichiometries of the phases were determined. The SmFeTa material was found to contain significant amounts of TaFe2as well as the Sm2Fe17, SmFe2, SmFe3 phases observed in the SmFe material but without the a-iron dendrites which are characteristic of the latter material. The optimum conditions necessary to provide the highest coercivities using the conventional HDDR process, and for the HDDR process combined with pre-milling were investigated. The coercivities obtained after using the HDDR process and subsequent nitriding were 680 kA/m for the SmFeTaN and 360 kA/m for the SmFeN samples. Significantly higher coercivites of 1000 kA/m for SmFeN and 1275 kA/m for SmFeTaN were achieved by reducing the particle size with milling prior to the HDDR process.The better coercivities obtained with the Ta containing sample were found to be due to the presence of a much smaller amount of a. The milling prior to the HDDR treatment improves the magnetic properties because of the small particle size which prevents the grains growing too large, with their consequent very negative effect on the coercivity.