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In reactor pressure vessel materials, the formation of Mn- and Ni-rich nanoclusters is a major cause of neutron irradiation embrittlement. The segregation of these solute atoms into dislocation loops has attracted attention as a mechanism to accelerate solute clustering. In this study, the behaviors of solute Mn and Ni atoms in Fe-0.6wt.%Ni, Fe-1.4wt.%Mn, and Fe-1.4wt.%Mn-0.6wt.%Ni alloys irradiated at 400 °C up to 3 dpa were analyzed using three-dimensional atom probe tomography. Solute atom clusters were observed in all materials, and their shapes were spherical, flat, and torus in FeNi, FeMn, and FeMnNi, respectively. In ternary alloy FeMnNi, Mn and Ni atoms were concentrated in the sample in the form of arcs, and the orientation of the plane containing the arcs was estimated by comparing field desorption images. The size, number density, and orientation of this structure were found to be in good agreement with those of both types of dislocation loops, namely, b = 1/2 〈111〉 and b = 〈100〉, identified in a previous study using the same material. The positions of Ni and Mn enrichment did not fully overlap. Ni atoms tended to be concentrated more in the inner part of the loop than the Mn atoms. Mn atoms were enriched only in the vicinity of the dislocation loops, whereas Ni atoms showed a higher concentration inside the dislocation loops than in the bulk.

The PiXeL detector (PXL) for the Heavy Flavor Tracker (HFT) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. Custom built pixel sensors, their readout electronics and the detector mechanical structure are described in detail. Selected detector design aspects and production steps are presented. The detector operations during the three years of data taking (2014–2016) and the overall performance exceeding the design specifications are discussed in the conclusive sections of this paper.

Mn6Ni16Si7 intermetallic compounds, referred to as the G phase, and their precursors are recognized as potential secondary phases precipitated in neutron-irradiated steels and are the main cause of embrittlement in low-alloyed reactor pressure vessel steels under long-term operation. To obtain the mechanical properties and thermal stability of the G phase, two Mn-Ni-Si model alloys (composed of 21 mol%Mn-58 mol%Ni-21 mol%Si and 30 mol%Mn-58 mol%Ni-12 mol%Si) were annealed at 1,000°C. The existence of the G phase in both annealed ternary model alloys was confirmed by XRD and SEM/EDS. Meanwhile, the process of different Mn-Ni-Si ternary regions to the G phase transformation under 1,000°C annealing has also been discussed. Young's modulus and nano-hardness of the G phase were measured using the nanoindentation technique. The results showed similar values for the G phase in two alloys with Young's modulus of approximately 220 GPa, which is similar to Young's modulus of iron. This fact suggests the necessity of reconsideration of the hardening model contributed by G phase precipitates in reactor pressure vessels in the future. [ABSTRACT FROM AUTHOR]

We describe a three Mimostar-2 Monolithic Active Pixel Sensor (MAPS) sensor telescope prototype with an accompanying readout system incorporating on-the-fly data sparsification. The system has been characterized and we report on the measured performance of the sensor telescope and readout system in beam tests conducted both at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL) and in the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). This effort is part of the development and prototyping work that will lead to a vertex detector for the STAR experiment.

A prototype readout system for the STAR PIXEL detector in the Heavy Flavor Tracker (HFT) vertex detector upgrade is presented. The PIXEL detector is a Monolithic Active Pixel Sensor (MAPS) based silicon pixel vertex detector fabricated in a commercial CMOS process that integrates the detector and front-end electronics layers in one silicon die. Two generations of MAPS prototypes designed specifically for the PIXEL are discussed. We have constructed a prototype telescope system consisting of three small MAPS sensors arranged in three parallel and coaxial planes with a readout system based on the readout architecture for PIXEL. This proposed readout architecture is simple and scales to the size required to readout the final detector. The real-time hit finding algorithm necessary for data rate reduction in the 400 million pixel detector is described, and aspects of the PIXEL system integration into the existing STAR framework are addressed. The complete system has been recently tested and shown to be fully functional. Index Terms--Cluster finding algorithm, complementary metal-oxide (CMOS) detectors, detector readout, silicon detectors.

A pocket-size gamma-ray spectrometer has been developed. It uses a large volume (2 [cm.sup.3]) CdZnTe coplanar-grid detector to achieve good detection efficiency and energy resolution. The spectrometer is completely self-contained. It includes pulse processing electronics, multichannel analyzer, data storage, LCD display, keypads, USB interface, and rechargeable battery. Custom software was created for spectrum acquisition, storage, and display. The power consumption of the spectrometer is 120 mW when active, allowing two days of continuous operation on a full battery charge. Index Terms--Gamma-ray spectroscopy detectors, semiconductor devices.

In this study, the fatigue characteristics are evaluated for a new extruded aluminum 7175 with an experimental composition that uses a magnesium-calcium alloy during the alloying process instead of the standard pure magnesium. Specimens of ECO-7175-v3 were fabricated and subjected to fatigue life testing, fatigue life data analysis, and observation of their fracture characteristics through optical microscopy and scanning electron microscopy (SEM), and metallography to study their grains and surface characteristics. The S-N curve shows that the fatigue life for the new fabricated ECO-7175-v3 aluminum can exceed 5×107 cycles, with a fatigue strength of approximately 220 MPa or less, about 40% of its tensile strength. The fatigue strength of ECO-7175-v3 is an improvement over ECO-7175-v1, which is also shown by its higher fatigue strength coefficient, σF′ , of 1,589.7 MPa. When ECO-7175-v3 specimens were subjected to stresses of up to 67% of the ultimate tensile strength (UTS), the fracture surfaces are shown generally to have softly defined fracture features and propagation bands. These fracture surface characteristics are unique to ECO-7175-v3 and are attributed to its larger average grain size. Irrespective of the stress amplitude, like ECO-7175-v1, all crack initiation points of all specimens are seen at the surface and no inclusions to act as stress concentrators are seen. Reliability analysis shows the hazard rates for ECO-7175-v3 remain relatively constant most of the time before increasing towards the end. The trend of the hazard rates indicates failures are due to wear-outs and not due to defects. Reliability analysis also shows that at any given fatigue life cycle and stress level, ECO-7175-v3 has a lower probability of failure compared to ECO-7175-v1. [ABSTRACT FROM AUTHOR]

Merosin deficient congenital muscular dystrophy type 1A (MDC1A) is caused by defects in the LAMA2 gene. Patients with MDC1A exhibit severe symptoms, including congenital hypotonia, delayed motor development and contractures. The present case report describes a Vietnamese male child with clinical manifestations of delayed motor development, limb-girdle muscular dystrophy, severe scoliosis and white matter abnormality in the brain. Whole exome sequencing (WES) was performed with subsequent validation using Sanger sequencing, and a de novo missense variant (NM_000426.3:c.1964T>C, p.Leu655Pro) and a splice site variant (NG_008678.1:c.3556-13T>A) in the LAMA2 gene of the proband was detected. The missense variant located in exon 14 and has not been reported previously, to the best of our knowledge; whereas the splice site variant has been previously reported to cause premature termination of transcription in patients with MDC1A. In silico tools predicted that the missense variant was damaging. Phenotype-genotype analysis suggested that this proband was associated with classical early onset MDC1A. The co-existence of a de novo and a heterozygous variant in the LAMA2 gene suggested that the de novo variant contributed to the autosomal recessive manner of the disease. Careful consideration of this event by clinical confirmation of parental carrier status may help to accurately determine the risk of occurrence of this disease in future offspring. Additionally, WES is recommended as a powerful tool to assist in identifying potentially causative variants for heterogeneous diseases such as MDC1A. [ABSTRACT FROM AUTHOR]

Background: Stem cell therapy has emerged as a promising method for improving motor function of patients with cerebral palsy. The aim of this study is to assess the safety and effectiveness of autologous bone marrow mononuclear stem cell transplantation in patients with cerebral palsy related to oxygen deprivation.Methods: An open label uncontrolled clinical trial was carried out at Vinmec International Hospital. The intervention consisted of two administrations of stem cells, the first at baseline and the second 3 months later. Improvement was monitored at 3 months and 6 months after the first administration of stem cells, using the Gross Motor Function Measure (GMFM) and Modified Ashworth Score which measures muscle tone.Results: No severe complications were recorded during the study. After transplantation, 12 patients encountered fever without infections and 9 patients experienced vomiting which was easily managed with medications. Gross motor function was markedly improved 3 months or 6 months after stem cell transplantation than at baseline. The post-transplantation GMFM-88 total score, each of its domains and the GMFM-66 percentile were all significantly higher (p-value < 0.001). Muscle spasticity also reduced significantly after transplantation (p-value < 0.001). The therapy was equally effective regardless of sex, age and GMFCS level (p-value > 0.05).Conclusion: Autologous bone marrow mononuclear cell transplantation appears to be a safe and effective therapy for patients with cerebral palsy.Trial Registration: ClinicalTrials.gov Identifier: NCT02569775 . Retrospectively registered on October 15, 2015. [ABSTRACT FROM AUTHOR]