1,606 research outputs found

    Impact of various heat treatments on the microstructure evolution and mechanical properties of hot forged 18CrNiMo7-6 steel

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    Carburizing is a method of enhancing the surface properties of components, primarily made from low to medium carbon steels, such as shafts, gears, bearings, etc. Carburized parts are generally quenched and tempered before being put into service; however, after quenching of carburized parts further annealing and hardening treatments can be employed before final tempering. This work analyses the impact of the two aforementioned heat treatment approaches on the development of subsequent microstructures and mechanical properties of hot forged 18CrNiMo7-6 steel. Moreover, this study aims to understand the impact of normalizing treatments prior to the two aforementioned heat treatment routes. Microstructural and mechanical tests were conducted on four as forged flat cylinder components that received a combination of the abovementioned heat treatments. In general, better microstructure refinement, in terms of prior austenite grain size (PAGS), was obtained for carburized parts that received the intermediate annealing and hardening treatments after quenching and prior to the final tempering. Additionally, further refinement of the martensitic pockets/blocks was observed for parts that did not receive a normalising treatment prior to carburisation. The studied heat treatments appear to have a negligible effect on the mechanical properties of the hot forged flat cylinder components

    Diabetic ketoacidosis in an adolescent and young adult population in the UK in 2014: a national survey comparison of management in paediatric and adult settings:Special Issue on Diabetes and Childhood

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    Aims: To assess the management of diabetic ketoacidosis in young people, which differs in the UK between paediatric and adult services, and to evaluate outcomes and extent to which national guidelines are used. Methods: A standardized questionnaire was sent to all paediatric and adult diabetes services in England, requesting details of all diabetic ketoacidosis admissions in young people aged > 14 years in paediatric services (‘paediatric’ patients), and in young adults up to the age of 22 years in adult services (‘adult’ patients). Results: A total of 64 adult patients aged ≤ 22 years (mean age 19.2 years) were reported, of whom seven were aged between 10 and 16 years. A total of 71 paediatric patients were reported [mean (range) age 14.9 (11–18) years]. We found that 85% of paediatric and 69% of adult patients were treated according to national guidelines, 99% of paediatric and 89% of adult patients were treated with 0.9% saline and fixed-rate insulin infusions and 16% of adult patients received an insulin bolus. Insulin treatment was initiated later in paediatric patients than in adult patients (100 vs 39 min; P < 0.001). In 23% of adult patients and 8.8% of paediatric patients, potassium levels were < 3.5 mmol/l (P < 0.005). The lowest mean potassium levels were 3.8 mmol/l in paediatric and 3.5 mmol/l in adult patients (P < 0.005). Hypoglycaemia occurred in 42.3% of paediatric and 36% of adult patients. Time to resolution was similar in paediatric and adult patients (16.0 vs 18.2 h), as was duration of hospital stay (2.35 vs 2.53 days). Conclusions: Young people were treated according to national guidelines, but the quality of monitoring was variable in both paediatric and adult settings. The incidence of hypoglycaemia and hypokalaemia was unacceptably high

    Extending the Arctic Sea Ice Freeboard and Sea Level Record with the Sentinel-3 Radar Altimeters

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    In February 2016 and April 2018 the European Space Agency launched the Sentinel-3A and 3B satellites respectively, as part of the European Commission’s multi-satellite Copernicus Programme. Here we process Sentinel-3A waveform data to estimate Arctic sea level anomaly and radar freeboard from November 2017 to April 2018. We compare our results to those from the CryoSat-2 satellite, and find an intermission bias on sea-level anomaly of 2 cm. We also find a mean radar freeboard difference of 1 cm, which we attribute to the use of empirical retrackers to retrieve lead and floe elevations. Ahead of Sentinel-3B waveform data being made available, we use orbit files to estimate the improvement in sampling resolution afforded by the addition of Sentinel-3A and 3B data to the CryoSat-2 dataset. By combining data from the three satellites, grid resolution or time-sampling can be almost tripled compared with using CryoSat-2 data alone

    Blinding multiprobe cosmological experiments

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    The goal of blinding is to hide an experiment's critical results - here the inferred cosmological parameters - until all decisions affecting its analysis have been finalized. This is especially important in the current era of precision cosmology,when the results of any newexperiment are closely scrutinized for consistency or tension with previous results. In analyses that combine multiple observational probes, like the combination of galaxy clustering and weak lensing in the Dark Energy Survey (DES), it is challenging to blind the results while retaining the ability to check for (in)consistency between different parts of the data. We propose a simple new blinding transformation, which works by modifying the summary statistics that are input to parameter estimation, such as two-point correlation functions. The transformation shifts the measured statistics to new values that are consistent with (blindly) shifted cosmological parameters while preserving internal (in)consistency. We apply the blinding transformation to simulated data for the projected DES Year 3 galaxy clustering and weak lensing analysis, demonstrating that practical blinding is achieved without significant perturbation of internalconsistency checks, asmeasured here by degradation of the χ2 between the data and best-fitting model. Our blinding method's performance is expected to improve as experiments evolve to higher precision and accuracy. © 2020 The Author(s)

    Neuronal activity mediated regulation of glutamate transporter GLT-1 surface diffusion in rat astrocytes in dissociated and slice cultures.

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    The astrocytic GLT-1 (or EAAT2) is the major glutamate transporter for clearing synaptic glutamate. While the diffusion dynamics of neurotransmitter receptors at the neuronal surface are well understood, far less is known regarding the surface trafficking of transporters in subcellular domains of the astrocyte membrane. Here, we have used live-cell imaging to study the mechanisms regulating GLT-1 surface diffusion in astrocytes in dissociated and brain slice cultures. Using GFP-time lapse imaging, we show that GLT-1 forms stable clusters that are dispersed rapidly and reversibly upon glutamate treatment in a transporter activity-dependent manner. Fluorescence recovery after photobleaching and single particle tracking using quantum dots revealed that clustered GLT-1 is more stable than diffuse GLT-1 and that glutamate increases GLT-1 surface diffusion in the astrocyte membrane. Interestingly, the two main GLT-1 isoforms expressed in the brain, GLT-1a and GLT-1b, are both found to be stabilized opposed to synapses under basal conditions, with GLT-1b more so. GLT-1 surface mobility is increased in proximity to activated synapses and alterations of neuronal activity can bidirectionally modulate the dynamics of both GLT-1 isoforms. Altogether, these data reveal that astrocytic GLT-1 surface mobility, via its transport activity, is modulated during neuronal firing, which may be a key process for shaping glutamate clearance and glutamatergic synaptic transmission

    A 4q35.2 subtelomeric deletion identified in a screen of patients with co-morbid psychiatric illness and mental retardation

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    BACKGROUND: Cryptic structural abnormalities within the subtelomeric regions of chromosomes have been the focus of much recent research because of their discovery in a percentage of people with mental retardation (UK terminology: learning disability). These studies focused on subjects (largely children) with various severities of intellectual impairment with or without additional physical clinical features such as dysmorphisms. However it is well established that prevalence of schizophrenia is around three times greater in those with mild mental retardation. The rates of bipolar disorder and major depressive disorder have also been reported as increased in people with mental retardation. We describe here a screen for telomeric abnormalities in a cohort of 69 patients in which mental retardation co-exists with severe psychiatric illness. METHODS: We have applied two techniques, subtelomeric fluorescence in situ hybridisation (FISH) and multiplex amplifiable probe hybridisation (MAPH) to detect abnormalities in the patient group. RESULTS: A subtelomeric deletion was discovered involving loss of 4q in a patient with co-morbid schizoaffective disorder and mental retardation. CONCLUSION: The precise region of loss has been defined allowing us to identify genes that may contribute to the clinical phenotype through hemizygosity. Interestingly, the region of 4q loss exactly matches that linked to bipolar affective disorder in a large multiply affected Australian kindred

    The effects of Bleomycin A5 on infantile maxillofacial haemangioma

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    <p>Abstract</p> <p>Objective</p> <p>To examine the effects of bleomycin A5 on infantile maxillofacial haemangiomas.</p> <p>Methods</p> <p>Bleomycin A5 was given by multiple intralesinoal injections and the dosage was given according to the age of the patient and size of the lesion. Parts of patients were accompanied by prednisone treatment(2-5 mg/kg, po, QOD.</p> <p>Results</p> <p>All the haemangiomas involuted completely after treated with bloemycin A5 with better recovery of skin color and less scar forming in small haemangiomas.</p> <p>Conclusion</p> <p>Infantile haemangioma could be effectively treated with bleomycin A5 without serious side effects.</p
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