Preparation of Cu-based bulk metallic glasses by suction casting

A series of Cu-Hf-Ti alloys prepared by rapid solidification of the melt and by copper mould casting were studied in the present work. Alloy ingots were prepared by arc-melting mixtures of pure metals in an argon atmosphere. An indication of the cooling rate obtained was determined using an Al-4.5 wt%Cu alloy. Cooling rates varied from 540 K/s for the centre section of a 4 mm die to 885 K/s for the outside wall section of the 2 mm die. The glass-forming ability, structure and thermal stability of Cu-Hf-Ti glassy alloys were studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analysis (DTA). Bulk glass formation was observed for the Cu64Hf36, Cu55Hf25Ti20 and Cu56Hf25Ti19 alloys, with critical diameters dc for a fully glassy structure of 1, 4 and 5 mm, respectively. The substitution of Hf by Ti increased the glassforming ability (GFA) and the thermal stability

Evolution of Clinical Trials throughout History

The history of clinical research accounts for the high ethical, scientific, and regulatory standards represented in current practice. In this review, we aim to describe the advances that grew from failures and provide a comprehensive view of how the current gold standard of clinical practice was born. This discussion of the evolution of clinical trials considers the length of time and efforts that were made in order to designate the primary objective, which is providing better care for our patients. A gradual, historic progression of scientific methods such as comparison of interventions, randomization, blinding, and placebos in clinical trials demonstrates how these techniques are collectively responsible for a continuous advancement of clinical care. Developments over the years have been ethical as well as clinical. The Belmont Report, which many investigators lack appreciation due to time constraints, represents the pinnacle of ethical standards and was developed due to significant misconduct. Understanding the history of clinical research may help investigators appreciate the responsibility of conducting human subjects’ research

Symptomology Associated with in Utero Exposures to Polysubstance in an Appalachian Population.

Neonatal abstinence syndrome (NAS) is seen as a very high rate at our institution in Huntington, West Virginia, and the majority of exposures are polysubstance in nature. Polysubstance can have different meaning for each region. At our institution, polysubstance is any combination of opioids, gabapentin, methamphetamine, cocaine, marijuana, benzodiazepines, nicotine or other neuroactive substances with 3-4 substances being the norm. Rapidly changing combinations of drug use and the lack of literature create a difficult situation for clinicians who are often reliant on treatment recommendations that lack references or conclusive data supporting the clinical approaches. Elucidating withdrawal symptoms consistent with in utero exposures to particular drug combinations is difficult. Many substances induce similar withdrawal symptoms in neonates and the vast majority of cases present as polysubstance exposure. Standard methodology often leads to a research approach which isolates populations and substance of exposure to determine the individual effects on the neonate. In some drug combinations, like opioid and gabapentin exposure, the substances in concert create symptoms and complications that are not observed with either drug alone. The history of responses to substance use epidemics has been to handle each drug as a separate disease process, this is no longer a viable option. The following is a review of the literature available discussing individual substance withdrawal characteristics in neonates combined with the clinical insight gained at our hospital from treating such high rates of complex polysubstance exposure

Increasing Number of Unusual Brain Abnormalities Seen in Rural West Virginia

The incidence rate of schizencephaly is 1.5 in 100,000 live births and the rate of holoprosencephaly is 1 in 16,000 live births. Both malformations are rare, but our institution has seen a dramatic increase in both malformations in recent years with no known cause. Schizencephaly is the most severe cortical malformation and holoprosencephaly is the most common defect in the prosencephalon during development however, it is still not very common to see a fetus with this defect live to delivery. Our institution seen four cases of schizencephaly and three cases of holoprosencephaly within two years. No two neonates seem to share a common factor. All had different co-morbidities and presentations, all mothers were different ages and showed few risk factors if any for these deformities. This paper is a report of the cases found of these rare birth defects seen at our institution in recent years

Evidence for diversifying selection of genetic regions of encoding putative collagen-like host-adhesive fibers in Pasteuria penetrans

© FEMS 2018. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Pasteuria spp. belong to a group of genetically diverse endospore-forming bacteria (phylum: Firmicutes) that are known to parasitize plant-parasitic nematodes and water fleas (Daphnia spp.). Collagen-like fibres form the nap on the surface of endospores and the genes encoding these sequences have been hypothesised to be involved in the adhesion of the endospores of Pasteuria spp. to their hosts. We report a group of 17 unique collagen-like genes putatively encoded by Pasteuria penetrans (strain: Res148) that formed five different phylogenetic clusters and suggest that collagen-like proteins are an important source of genetic diversity in animal pathogenic Firmicutes including Pasteuria. Additionally, and unexpectedly, we identified a putative collagen-like sequence which had a very different sequence structure to the other collagen-like proteins but was similar to the protein sequences in Megaviruses that are involved in host-parasite interactions. We, therefore, suggest that these diverse endospore surface proteins in Pasteuria are involved in biological functions, such as cellular adhesion; however, they are not of monophyletic origin and were possibly obtained de novo by mutation or possibly through selection acting upon several historic horizontal gene transfer events.Peer reviewedFinal Published versio

Reconstruction of microscopic thermal fields from oversampled infrared images in laser-based powder bed fusion

This article elucidates the need to consider the inherent spatial transfer function (blur), of any thermographic instrument used to measure thermal fields. Infrared thermographic data were acquired from a modified, commercial, laser-based powder bed fusion printer. A validated methodology was used to correct for spatial transfer function errors in the measured thermal fields. The methodology was found to make a difference of 40% to the measured signal levels and a 174 °C difference to the calculated effective temperature. The spatial gradients in the processed thermal fields were found to increase significantly. These corrections make a significant difference to the accuracy of validation data for process and microstructure modeling. We demonstrate the need for consideration of image blur when quantifying the thermal fields in laser-based powder bed fusion in this wor

Functional magnetic resonance imaging outcomes from a comprehensive magnetic resonance study of children with fetal alcohol spectrum disorders

A comprehensive neuropsychological/psychiatric, MR imaging, (MRI), MR spectroscopy (MRS), and functional MRI (fMRI) assessment was administered to children with fetal alcohol spectrum disorders (FASD) to determine if global and/or focal abnormalities could be identified, and distinguish diagnostic subclassifications across the spectrum. The four study groups included: 1. FAS/Partial FAS; 2. Static Encephalopathy/Alcohol Exposed (SE/AE); 3. Neurobehavioral Disorder/Alcohol Exposed (ND/AE); and 4. healthy peers with no prenatal alcohol exposure. fMRI outcomes are reported here. The neuropsychological/psychiatric, MRI, and MRS outcomes are reported separately. fMRI was used to assess activation in seven brain regions during performance of N-back working memory tasks. Children across the full spectrum of FASD exhibited significant working memory deficits and altered activation patterns in brain regions that are known to be involved in working memory. These results demonstrate the potential research and diagnostic value of this non-invasive MR tool in the field of FASD