45 research outputs found

    Philosophy, Ethics, and Humanities in Medicine: Expanding the open-access conversation on health care

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    Natural philosophy once spanned the fields of philosophy, science, and medicine. Scientific disciplines and medical specialties have rapidly achieved independence, and the availability of the internet and open-access publishing promises a further expansion of knowledge. Nevertheless, a consideration of the grounding concepts and ethical principles that underlie health care remains paramount. It is timely, therefore, to contribute to the global conversation on health care with an open-access journal that focuses on addressing the conceptual basis of medicine and related disciplines, considering the ethical aspects of clinical practice, and exploring its intersection with the humanities (including history of medicine)

    Bayesian deconvolution of vessel residence time distribution

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    Residence time distribution (RTD) within vessels is a critical aspect for the design and operation of continuous flow technologies, such as hydrothermal synthesis of nanomaterials (Cabanas, Darr et al. 2000). RTD affects product characteristics, such as particle size distribution. Tracer techniques allow measurement of RTD, but often cannot be used on an individual vessel in multiple vessel systems due to unsuitable exit flow conditions. However, RTD can be measured indirectly by removal of this vessel from the system and deconvoluting the resulting detected tracer profile from the original trace of the entire system. This paper presents three models for deconvolution of RTD: BAY an application of the Lucy-Richardson iterative algorithm (Richardson 1972, Lucy 1974) using Bayes’ Theorem, LSQ an adaptation of a least squares error approach (Blackburn 1970) and FFT a Fast Fourier Transform. These techniques do not require any assumption about the form of the RTD. The three models are all accurate in theoretical tests with no simulated measurement error. For scenarios with simulated measurement error in the convoluted distribution, the FFT and BAY models are both very accurate. The LSQ model is the least suitable and the output is very noisy; smoothing functions can produce smooth curves, but the resulting RTD is less accurate than the other models. In experimental tests the BAY and FFT models produce near identical results which are very accurate. Both models run quickly, but in real time control the runtime for BAY would have to be considered further. BAY does not require any filtering or smoothing here, and so potentially there are applications where it might be more useful than FFT

    Death, organ transplantation and medical practice

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    A series of papers in Philosophy, Ethics and Humanities in Medicine (PEHM) have recently disputed whether non-heart beating organ donors are alive and whether non-heart beating organ donation (NHBD) contravenes the dead donor rule. Several authors who argue that NHBD involves harvesting organs from live patients appeal to "strong irreversibility" (death beyond the reach of resuscitative efforts to restore life) as a necessary criterion that patients must meet before physicians can declare them to be dead. Sam Shemie, who defends our current practice of NHBD, holds that in fact physicians consider patients to be dead or not according to physician intention to resuscitate or not

    A techno-economic assessment of the potential for combining supercritical water oxidation with ‘in-situ’ hydrothermal synthesis of nanocatalysts using a counter current mixing reactor

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    A combined process of supercritical water oxidation (SCWO) and supercritical water hydrothermal synthesis (SCWHS) in a continuous counter current reactor is reported. Acrylic acid was used as a model unsaturated carboxylic acid compound and the effects of the reaction temperature, residence time, oxidant ratio and acrylic acid concentration on chemical oxygen demand (COD) were all investigated. Two different experimental configurations for oxidant delivery were carried out in ‘pre-heated’ and ‘non-preheated’ oxidant configurations. With a stoichiometric excess of 100% oxygen, COD reduction levels of 80% (non-preheated) and 15% (preheated) were achieved with very short residence times. SCWHS was achieved through the addition of small amounts of various soluble metal salts in the cold upflow resulted in nanoparticles forming which increased the reaction rate and hydrothermal oxidation efficiency. The addition of small amounts of chromium nitrate (>5mM) results in nearly 100% COD reduction at 380 °C and residence times of 0.75 s. The potential economic benefits of combining the two processes together, in the different configurations, were also evaluated

    Structure-Based Optimization of a Novel Class of Aldehyde Dehydrogenase 1A (ALDH1A) Subfamily-Selective Inhibitors as Potential Adjuncts to Ovarian Cancer Chemotherapy

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    Aldehyde dehydrogenase (ALDH) activity is commonly used as a marker to identify cancer stem-like cells. The three ALDH1A isoforms have all been individually implicated in cancer stem-like cells and in chemoresistance; however, which isoform is preferentially expressed varies between cell lines. We sought to explore the structural determinants of ALDH1A isoform selectivity in a series of small-molecule inhibitors in support of research into the role of ALDH1A in cancer stem cells. An SAR campaign guided by a cocrystal structure of the HTS hit CM39 (7) with ALDH1A1 afforded first-in-class inhibitors of the ALDH1A subfamily with excellent selectivity over the homologous ALDH2 isoform. We also discovered the first reported modestly selective single isoform 1A2 and 1A3 inhibitors. Two compounds, 13g and 13h, depleted the CD133+ putative cancer stem cell pool, synergized with cisplatin, and achieved efficacious concentrations in vivo following IP administration. Compound 13h additionally synergized with cisplatin in a patient-derived ovarian cancer spheroid model

    Factors affecting the microwave coking of coals and the implications on microwave cavity design

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    The work carried out in this paper assessed how processing conditions and feedstock affect the quality of the coke produced during microwave coke making. The aim was to gather information that would support the development of an optimised microwave coke making oven. Experiments were carried out in a non-optimised 2450 MHz cylindrical cavity. The effect of treatment time (15–120 min), power input (750 W–4.5 kW) and overall power input (1700–27,200 kWh/t) on a range of coals (semi-bituminous–anthracite) was investigated. Intrinsic reactivity, random reflectance, strength index and dielectric properties of the produced cokes were compared with those of two commercial cokes to assess the degree of coking produced in the microwave system. Overall energy input and coal rank were found to be the major factors determining the degree of coking following microwave treatment. The dependency on coal rank was attributed to the larger amount of volatiles that had to be removed from the lower ranked coals, and the increasing dielectric loss of the organic component of the coal with rank due to increased structural ordering. Longer treatment times at lower powers or shorter treatment times at higher powers are expected to produce the same degree of coking. It was concluded that microwave coke making represents a potential step-change in the coking industry by reducing treatment times by an order of magnitude, introducing flexibility and potentially decreasing the sensitivity to quality requirement in the feedstock. The main challenges to development are the energy requirements (which will need to be significantly reduced in an optimised process) and penetration depth (which will require an innovative reactor design to maximise the advantage of using microwaves). Understanding and quantifying the rapidly changing dielectric properties of the coal and coke materials is vital in addressing both of these challenges

    Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation

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    Continuous hydrothermal synthesis was highlighted in a recent review as an enabling technology for the production of nanoparticles. In recent years, it has been shown to be a suitable reaction medium for the synthesis of a wide range of nanomaterials. Many single and complex nanomaterials such as metals, metal oxides, doped oxides, carbonates, sulfides, hydroxides, phosphates, and metal organic frameworks can be formed using continuous hydrothermal synthesis techniques. This work presents a methodology to characterize continuous hydrothermal flow systems both experimentally and numerically, and to determine the scalability of a counter current supercritical water reactor for the large scale production (>1,000 T·year–1) of nanomaterials. Experiments were performed using a purpose-built continuous flow rig, featuring an injection loop on a metal salt feed line, which allowed the injection of a chromophoric tracer. At the system outlet, the tracer was detected using UV/Vis absorption, which could be used to measure the residence time distribution within the reactor volume. Computational fluid dynamics (CFD) calculations were also conducted using a modeled geometry to represent the experimental apparatus. The performance of the CFD model was tested against experimental data, verifying that the CFD model accurately predicted the nucleation and growth of the nanomaterials inside the reactor

    Book Review

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    Science, Practice, and the Reform of American Medical Education

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    180 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.Tension has been often felt between science and practice in practical occupations undergirded by science. The reform of medical education in America provided an occasion for the working out of this tension in medicine. In early nineteenth century American medicine the two sides of this divide were represented by followers of the Paris Clinical School and by advocates of the doctrine of specificity. The influence of these two opposite approaches to medical thinking and practice were reflected in the early debates between the Harvard medical faculty and the AMA over educational reform in the 1840s and 50s; and in the debates at Harvard over the Eliot reforms of 1871. The actual measures taken in the 70s and 80s at Harvard and elsewhere, however, did not constitute victory for either side of the controversy. Reform measures that palpably followed from a reductionist viewpoint were propounded only in the 1890s and after by militant basic scientists influenced by German laboratory research. The objections made to such measures by clinicians representing various shades of anti-reductionist opinion bore many similarities to those raised by earlier opponents of less tendentious reforms at midcentury. The eventual outcome of reform battles at Harvard and other medical schools in the late teens and 1920s cannot fairly be characterized as a straight forward victory for the reductionist scientists over practitioners. The basic scientists were able to transform medicine's fundamental branches according to their distinctive view of medical practice as the unproblematic application of their own disciplines. In the clinical branches and in other matters of medical school policy they were forced to compromise with their clinician opponents. Still less can reform be seen as a simple triumph of "science" over obscurantism. Most of those on either side of the debate favored the high standards, active teaching and larger role for research that were increasingly realized in elite medical schools by 1920.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
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