Leaching Properties of Estuarine Harbor Sediment Before and After Electrodialytic Remediation

Electrodialytic remediation (EDR) can be used to extract heavy metals from a variety of different media. In this work, contaminated harbor sediments from two locations in the United States and one in Norway were subjected to EDR, and were compared with batch extractions conducted with the sediment. pH-dependent leaching tests were used to evaluate changes in leaching properties of treated and control sediments. Significant fractions of total concentrations were removed during treatment (35–95% with an average of 75% for all sediments and elements investigated). The release of elements in pH-dependent leaching tests, however, demonstrated equal or greater leaching from treated sediments in the neutral pH range. Dissolved organic carbon appears to be a significant contributor to post-treatment increases in leaching, and dissolution of significant iron and aluminum sorption sites is hypothesized to also play a role. This research highlights the importance of understanding contaminant speciation and availability, as total metals concentrations, in this particular case, do not relate to estimates of the environmental availability of metals (total concentrations were typically two to three orders of magnitude greater than concentrations released during pH-dependent leaching)

Status of a Power Processor for the Prometheus-1 Electric Propulsion System

NASA is developing technologies for nuclear electric propulsion for proposed deep space missions in support of the Exploration initiative under Project Prometheus. Electrical power produced by the combination of a fission-based power source and a Brayton power conversion and distribution system is used by a high specific impulse ion propulsion system to propel the spaceship. The ion propulsion system include the thruster, power processor and propellant feed system. A power processor technology development effort was initiated under Project Prometheus to develop high performance and lightweight power-processing technologies suitable for the application. This effort faces multiple challenges including developing radiation hardened power modules and converters with very high power capability and efficiency to minimize the impact on the power conversion and distribution system as well as the heat rejection system. This paper documents the design and test results of the first version of the beam supply, the design of a second version of the beam supply and the design and test results of the ancillary supplies

Clinical ethics revisited

A decade ago, we reviewed the field of clinical ethics; assessed its progress in research, education, and ethics committees and consultation; and made predictions about the future of the field. In this article, we revisit clinical ethics to examine our earlier observations, highlight key developments, and discuss remaining challenges for clinical ethics, including the need to develop a global perspective on clinical ethics problems

Clinical Ethics in Gabon: The Spectrum of Clinical Ethical Issues Based on Findings from In-Depth Interviews at Three Public Hospitals

Introduction Unlike issues in biomedical research ethics, ethical challenges arising in daily clinical care in Sub-Saharan African countries have not yet been studied in a systematic manner. However this has to be seen as a distinct entity as we argue in this paper. Our aim was to give an overview of the spectrum of clinical ethical issues and to understand what influences clinical ethics in the Sub-Saharan country of Gabon. Materials and Methods In-depth interviews with 18 health care professionals were conducted at three hospital sites in Gabon. Interview transcripts were analyzed using a grounded theory approach (open and axial coding),giving a qualitative spectrum of categories for clinical ethical issues. Validity was checked at a meeting with study participants and other health care experts in Gabon after analysis of the data. Results Twelve main categories (with 28 further-specified subcategories) for clinical ethical issues were identified and grouped under three core categories: A) micro level: "confidentiality and information","interpersonal, relational and behavioral issues","psychological strain of individuals",and "scarce resources";B) meso level: "structural issues of medical institutions","issues with private clinics","challenges connected to the family",and "issues of education, training and competence";and C) macro level: "influence of society, culture, religion and superstition","applicability of western medicine","structural issues on the political level",and "legal issues". Discussion Interviewees reported a broad spectrum of clinical ethical issues that go beyond challenges related to scarce financial and human resources. Specific socio-cultural, historical and educational backgrounds also played an important role. In fact these influences are central to an understanding of clinical ethics in the studied local context. Further research in the region is necessary to put our study into perspective. As many participants reported a lack of awareness of ethical issues amongst other health care professionals in daily clinical practice, we suggest that international organizations and national medical schools should consider infrastructure and tools to improve context-sensitive capacity building in clinical ethics for Sub-Saharan African countries like Gabon

The role of hospital ethics committees in emergency medicine practice

Emergency physicians face real-time ethical dilemmas that may occur at any hour of the day or night. Hospital ethics committees and ethics consultation services are not always able to provide immediate responses to emergency physicians\u27 consultation requests. When faced with an emergent dilemma, emergency physicians sometimes rely on risk management or hospital counsel to answer legal questions, but may be better served by real-time ethics consultation. When other resources are not immediately available, emergency physicians should feel confident in making timely decisions, guided by basic principles of medical ethics. We make the following recommendations: (1) availability of a member of the hospital ethics committee to provide in-person or telephonic consultation concurrent with patient care; (2) appointment to the hospital ethics committee of an emergency physician who is familiar with bioethical principles and is available for consultation when other ethics consultants are not; and (3) development of educational tools by professional societies or similar organizations to assist emergency physicians in making reasoned and defensible clinical ethics decisions

Disclosing the extensive crystal chemistry of Ivabradine hydrochloride, in its pure and solvated phases

Powder diffraction data are presented for Ivabradine hydrochloride (pure and solvated forms), a drug marketed worldwide for symptomatic treatment of angina pectoris and inappropriate sinus tachycardia. [Ivrabradine: 3-[3-({[(7S)-3,4-dimethoxy bicyclo[4.2.0]octa-1,3,5-trien-7-yl]methyl}(methyl)amino)propyl]-7,8-dimethoxy-2,3,4,5-tetrahydro-1H-3-benzazepin-2-one]. Many are the different (polymorphic or solvated) phases claimed in the scientific or forensic literature. We have here prepared monophasic samples of six different ivabradine hydrochloride species. Exposure to water vapours, at room temperature, of the anhydrous δ-d form generated pure powders of the tetrahydrate form (the β-form). Two different anhydrous forms (β-d and α) were prepared by gentle, or extensive, heating of the β and δ-d forms, respectively. Acetonitrile and acetone solvates (hereafter called δ1- and δ2-forms) were obtained by precipitation methods from concentrated solutions. Diffraction data were collected on laboratory equipment with Ni-filtered CuKα radiation; cell parameters and space groups were determined from ab initio indexing procedures using the SVD algorithm.</jats:p