SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Ion chromatography as we know it today was built on a foundation of knowledge accumulated over a period of many years. Here, we review some of the outstanding earlier achievements in ion-exchange chromatography. Beginning about 1947. Spedding and Powell at Iowa State published a series of papers describing practical methods for preparative separation of the rare earths by displacement ion-exchange chromatography. The same group then demonstrated the ion-exchange separation of 14N and 15N isotopes in ammonia. Beginning in the 1950s. Kraus and Nelson at Oak Ridge published numerous analytical methods for metal ions based on separation of their chloride, fluoride, nitrate or sulfate complexes by anion chromatography. In the period from about 1960 to 1980 many clever chromatographic methods for metal ion separations were reported by researchers throughout the world and automatic in-line detection was gradually introduced. A truly innovative method by Small, Stevens and Bauman at Dow Chemical Co. marked the birth of modern ion chromatography. Anions, as well as cations, could now be separated quickly and conveniently by a system of suppressed conductivity detection. A method for anion chromatography with non-suppressed conductivity detection was published by Gjerde et al. in 1979. This was followed by a similar method for cation chromatography in 1980. Ion chromatography as we know it today did not just happen. It was built on a solid foundation of knowledge that has accumulated over a period of many years. Revisiting the older ion-exchange chromatography serves not only to pay tribute to some remarkable accomplishments, but it can also be a learning experience. Trends and ideas in science tend to run in repeating cycles. Thus, an awareness of older work may provide inspiration for new research using improved contemporary technology. Selection of milestones is a rather personal matter. I chose to write about subjects of which I came to have a firsthand knowledge during my career. The topics selected are in roughly chronological order and cover the period from about 1945 to 1980. An effort has been made to explain the chemical principles as well as to recount the major accomplishments of the various research projects.
Knowledge management provides a means for sharing data, lessons learned, and accumulated knowledge throughout an organization or within an entire industry. Gone are the days of hoarding knowledge to ensure job security; today's workers and managers must work together to find new and innovative ways to use what they know and optimize how that knowledge is accessed. Knowledge management's new approach to shared intellectual resources has implications for workers and managers in all fields and promises to redraw the management landscape. But are healthcare organizations setting the stage for reengineering themselves all over again?
As a profession, occupational therapists are guided in practice by the accumulated knowledge of occupational therapy. This article demonstrates the contributions of life-history and narrative research to this knowledge base. We are suggesting that in response to our humanistic roots, we must pursue additional knowledge, principles of practice, and ethical philosophies that support practice. We have argued that our ideologic concern for the client must guide our choice of epistemologies to investigate the lived experience to those whom we serve. "What is at stake here is the ethic that is embedded in the epistemology that gives rise to kinds of research" (Brock, 1995, p.157) that meet the societal demands for professionalism and support a humanistic practice.
There is a dearth of knowledge about the problem of child maltreatment in Arab societies. In the West Bank and Gaza Strip, the Palestinians are facing the challenge of establishing their own social welfare system as a result of signing the Declaration of Principles with Israel. In creating services for families and children, the helping professionals in these areas find that one of the main challenges is to integrate and apply knowledge accumulated in Western countries into a different sociocultural context. Another challenge is to develop knowledge on this subject congruent with their own cultural background. Because of this lack of knowledge, a study was conducted among 353 students in the helping professions in the West Bank. An instrument constructed for this study was utilized to examine the following subjects: (a) students' perceptions of situations of child maltreatment; (b) their awareness of signs of maltreated children; (c) their awareness of risk factors which could be related to this problem; and (d) their willingness to report cases of child maltreatment. The results indicate a high level of agreement among students in viewing situations of abuse as well as neglect as maltreatment. Differences were found in their willingness to report situations of maltreatment. A higher tendency was found to report situations of abuse rather than neglect. An inclination was found among students to minimize social and cultural factors as risk factors and to disregard signs that did not contain explicit signals of danger as characteristics of maltreated children. Implications for the development of services in Arab societies are discussed.
At the Canadian Health Services Research Foundation we talk a lot about the need to improve the 'receptor capacity' for research in the health sector (Canadian Health Services Research Foundation 2000). To create a demand for research as well as a supply of it. To encourage and assist clinicians, managers and policymakers in the health system to pull research from academe with as much fervor as applied researchers now bring to publishing it. Browman, Snider and Ellis have done more than talk about and encourage these things - they have implemented them at their own workplace in Hamilton. Their formula is:1. Design a policy-learning forum (Clinical Policy Committee'), where the use of available research is encouraged and expected 2. Create champions (knowledge stewards') responsible for marshalling and presenting the evidence. 3. Provide rules (negotiation') for the dialogue between the operational implications of the research and its budgetary reality. 4. Use story telling to uncover local implementation barriers and make tacit knowledge explicit. The approach is reminiscent of political scientist Paul Sabatier's description of the circumstances under which policy learning occurs (Sabatier and Jenkins-Smith 1993) and Brown and Duguid's compelling outline of how information permeates corporate structures (Brown and Duguid 2000). Sabatiers advocacy coalition framework highlights the optimal conditions for learning as: balanced coalitions (in this case, of those behind the research and those behind the finances), enough resources for each side to produce a steady flow of information, an organized forum for debate and clear rules of engagement. In 'The Social Life of Information, 'Brown and Duguid highlight the extent to which modern corporations often leave unrecognized and under-utilized their greatest asset - the tacit knowledge accumulated by each employee over his or her career. They, too, recommend storytelling as a way to liberate this knowledge for wider use. Browman and colleagues 'practical realization of Sabatier' advocacy coalition framework and Browns social view of information is refreshing on a number of levels.
MOTIVATION: A methodology to search for genes associated with multifactorial diseases by integrating the large amount of accumulated knowledge is seriously needed. A comprehensive understanding derived from a holistic view of gene relationship structures can be gained from our proposed analysis called the cross-subspace analysis (CSA). In this analysis, gene objects are generated by machine learning using their term occurrence patterns in MEDLINE abstracts and the degree of relationship between gene objects is quantified by matching these patterns. RESULTS: Structuralization of relationships of a set of genes was performed using CSA, which were retrieved using the terms, 'obesity', 'diabetes', 'hypertriglyceridemia' and 'hypertension' that refer to diseases comprising metabolic syndrome, on a 2D plane inferring important biomedical concepts from the gene distribution. Then, we prioritized the significance of 6131 well-annotated human genes in terms of the distance on the plane from the centroid of 'metabolic syndrome'-related genes distribution. The validity was confirmed by comparing the knowledge extracted by the ordering with existing medical knowledge.
OBJECTIVE: Aged populations in the United States are growing in numbers, and stand to be affected most by the changing shape of healthcare delivery. Within these elderly populations, the problem of decreased cognitive functioning due to dementing disorders is rising. Recent compelling research on complementary and alternative medicine interventions targeted at cognitive deficits in the elderly is reviewed in this survey. DATA SOURCES: A literature review was undertaken to identify original clinical research studies, review articles, chapters, and books on treating cognitive deficits in the elderly. Contact with complementary and alternative medicine researchers provided additional information concerning developments in this field. STUDY SELECTION: Research studies that were methodologically sound were selected for review. More purely clinical studies also were included to provide a thorough overview of the limited amount of accumulated knowledge in this field. DATA SYNTHESIS: A qualitative synthesis of the above data was used to comprehensively present all information accumulated to date in this field. CONCLUSIONS: Although still in the preliminary stages of development, clinical research exploring the benefits of complementary and alternative therapies for cognitive deficits among the elderly shows a significant level of promise that warrants a further investment of resources.
This essay summarises a personal perspective on where we have got to in the five years since the turn of the last century. The focus is on advances in knowledge of antitumour necrosis factor (anti-TNF) therapy of rheumatoid arthritis and other chronic immune-inflammatory rheumatic diseases. The accumulating knowledge is clarifying the scope and limitations of efficacy, safety, and durability of these agents. It is defining the unmet needs of patients and communities worldwide for the future. The call is for progress in providing more cost-effective advances in therapeutics that not only interrupt the disease process long term but also reverse the anatomical and functional consequences of disease and the impairment in quality of life.
The development of science is believed to be a continuous accumulation of knowledge, giving rise to the somewhat false idea that the most recent knowledge is the most valid and most appropriate. Neglect of the history of a scientific discipline might therefore lead to reinvention of theories that have already been proposed and experimentally investigated. In the case of visual fatigue the pioneering works of Lucien Howe, Walter Lancaster and others at the beginning of this century are very similar to contemporary work in terms of conceptual definitions, methodological approach, assessment and results. The temporal and dynamic aspects of accommodation and vergence considered important today were intensely studied and discussed by Howe and others.
The control by the Food and Drug Administration (FDA) of aflatoxin, a relatively recently discovered, unavoidable natural contaminant produced by specific molds that invade a number of basic food and feedstuffs, provides an example of the varying forces that affect risk assessment and management by a regulatory Agency. This is the story of how the FDA responded to the initial discovery of a potential carcinogenic hazard to humans in a domestic commodity, to the developing information concerning the nature of the hazard, to the economic and political pressures that are created by the impact of natural forces on regulatory controls, and to the restraints of laws within which the Agency must work. This story covers four periods: the years of discovery and action decisions on the basis of meager knowledge and the fear of cancer; the years of tinkering on paper with the regulatory process, the years of digestion of the accumulating knowledge, and the application of that knowledge to actions forced by natural events; and an audit of the current status of knowledge about the hazard from aflatoxin, and proposals for regulatory control based on that knowledge.
The complement system plays an essential role in alerting the host of the presence of potential pathogens, as well as in their clearing. In addition, activation of the complement system contributes significantly in the orchestration and development of an acquired immune response. Although the complement system has been studied extensively in mammals, considerably less is known about complement in lower vertebrates, in particular teleost fish. Here we review our current understanding of the role of fish complement in phagocytosis, respiratory burst, chemotaxis and cell lysis. We also thoroughly review the specific complement components characterized thus far in various teleost fish species. In addition, we provide a comprehensive compilation on complement host-pathogen interactions, in which we analyze the role of fish complement in host defense against bacteria, viruses, fungi and parasites. From a more physiological perspective, we evaluate the knowledge accumulated on the influence of stress, nutrition and environmental factors on levels of complement activity and components, and how the use of this knowledge can benefit the aquaculture industry. Finally, we propose future directions that are likely to advance our understanding of the molecular evolution, structure and function of complement proteins in teleosts. Such studies will be pivotal in providing new insights into complement-related mechanisms of recognition and defense that are essential to maintaining fish homeostasis.
New knowledge and trends in research of renal failure have opened new vistas not only in understanding its pathogenesis, but also in developing its therapy. It has been, shown, however, that the knowledge accumulated, namely the characterization of so far unknown modulators is of importance also for the therapy of diseases of other organ systems. Moreover, the knowledge of receptors of competent endogenous regulators has created the conditions for synthesis of their analogues and thereby for development of agonists and antagonists. These are extraordinary significant trends, the development of which is desirable to be speeded up to the maximum.
Although qualitative studies are increasing in the discipline of nursing, their clinical application and knowledge development will be impeded unless the rich understandings revealed in these individual studies can be synthesized. Meta-synthesis is an invaluable method for accumulating knowledge from individual qualitative studies. This article describes a project focusing on qualitative synthesis that the author required her nursing students in a graduate-level research course to complete. In addition, qualitative meta-synthesis is defined, and its benefits are discussed. Then, Noblit and Hare's approach for synthesizing qualitative studies is described. The remainder of the article is devoted to explaining the actual course project and students' evaluation of the project. The benefits of having graduate students conduct a meta-synthesis are many, and as one student shared, "It was a wonderful, very interesting, and challenging way to teach us."
Increasing numbers of qualitative studies in maternal-child nursing are being published. However, clinical application and knowledge development based on those studies will be hampered unless the rich understandings gleaned from these individual studies can be synthesized. Meta-synthesis is one technique to help accumulate knowledge from qualitative research. The first section of this article explains the technique of meta-synthesis and reviews meta-syntheses published in nursing. The focus then becomes an illustration of a meta-synthesis in maternal-child nursing: Mothering multiples during the first year of life. Six qualitative studies comprised the sample for the meta-synthesis. The meta-synthesis revealed a shared set of five themes that help increase our understanding of mothering multiples: "bearing the burden," "riding an emotional roller coaster," "lifesaving support," "striving for maternal justice," and "acknowledging individuality." Implications for practice derived from this meta-synthesis are addressed.
The identification of GRH has been followed by an extraordinarily rapid rate of knowledge accumulation. Within a period of slightly more than 3 yr since the structure of the GRH was determined, nearly 500 papers have been published pertaining to the hormone. Extensive knowledge of its anatomy, chemistry, molecular biology, physiology, and pathology has been gathered and, in particular, studies in humans have proceeded faster than with any other of the hypophysiotropic hormones. New insights have been gained with respect to the pathogenesis of both GH deficiency and GH excess states, and the use of GRH and its analogs as diagnostic and therapeutic agents already represents a reality.
The transcriptional network of Escherichia coli may well be the most complete experimentally characterized network of a single cell. A rule-based approach was built to assess the degree of consistency between whole-genome microarray experiments in different experimental conditions and the accumulated knowledge in the literature compiled in RegulonDB, a data base of transcriptional regulation and operon organization in E. coli. We observed a high and statistical significant level of consistency, ranging from 70%-87%. When effector metabolites of regulatory proteins are not considered in the prediction of the active or inactive state of the regulators, consistency falls by up to 40%. Similarly, consistency decreases when rules for multiple regulatory interactions are altered or when "on" and "off" entries were assigned randomly. We modified the initial state of regulators and evaluated the propagation of errors in the network that do not correlate linearly with the connectivity of regulators. We interpret this deviation mainly as a result of the existence of redundant regulatory interactions. Consistency evaluation opens a new space of dialogue between theory and experiment, as the consequences of different assumptions can be evaluated and compared.
Knowledge of the genetic determinants that can affect renewal of multipotential stem cells and their commitment to specific cell lineages is essential to our understanding of multicellular development. However, despite the vast amount of accumulated knowledge in this area, genetic determinants that affect renewal and commitment of precursor cells are unknown. In this study, we demonstrate that three independently derived founder mouse strains, transgenic for the TcR V gamma 1.1J gamma 4C gamma 4 (TcR gamma 4) chain gene, differed significantly from normal mice in their development of T and B cells as well as myelopoietic precursor cells. Ontogenic programs consistent with an acceleration of T-cell development and a delayed appearance and suppressed levels of pre-B- and B-cell precursors were evident in these transgenic mice. In addition, TcR gamma 4 transgenic mice possessed a significantly elevated level of myelopoietic pluripotential precursors. 3H-thymidine cell suicide studies suggest that higher percentages of pluripotent precursors from the bone marrow of the TcR gamma 4 transgenic mice were in the S phase of the cell cycle. These modulations of the lymphoid and myelopoietic compartments, however, were not found in other T-cell receptor transgenic mice (e.g., TcR V gamma 1.2J gamma 2C gamma 2, TcR gamma 2; or V beta 8.1D beta J beta 2.4C beta 2, TcR beta) constructed with the same or similar cDNA expression vector. The results suggest that the expression of a specific T-cell receptor gamma chain gene, and/or an elevated level of particular subset of TcR gamma delta cells, may affect the proliferation and relative proportions of haemopoietic and lymphoid precursors.