3,035 research outputs found
Further Studies of the Optimum Operation of Desalting Plants as a Supplemental Source of Firm Yield
The Operating Rule Program was developed in an earlier study to furnish a means to determine optimum desalting plant size, optimal operating rule, and costs of operating in conjunction with existing water supply systems, under the present study, five further objectives were accomplished: (1) The program was applied to a New York City water supply system feasibility study in connection with a dual purpose nuclear power plant to develop costs for adding firm yield to the New York City water supply system in conjunctive operation with the desalting plant. (2) The program was modified to enable assessment of stage construction of desalting units when used in conjunction with a natural water supply system on the basis of both constant costs over the period of analysis and inflationary costs. Techniques were developed for applying the program to determine the optimal plant module size, timing of units, and cost of the water. (3) A separate, smaller program was developed to enable analysis of desalting plant operation in conjunction with a natural water supply system having no storage capacity. (4) A training program provided instruction to a selected group designated by OSW on the detailed use and application of the Modified Operating Rule Program. (5) A feasibility study of the Norfolk, Virginia, water supply system was also carried out by applying the modified program
Comparison of near-interface traps in AlO/4H-SiC and AlO/SiO/4H-SiC structures
Aluminum oxide (Al2O3) has been grown by atomic layer deposition on n-type
4H-SiC with and without a thin silicon dioxide (SiO2) intermediate layer. By
means of Capacitance Voltage and Thermal Dielectric Relaxation Current
measurements, the interface properties have been investigated. Whereas for the
samples with an interfacial SiO2 layer the highest near-interface trap density
is found at 0.3 eV below the conduction band edge, Ec, the samples with only
the Al2O3 dielectric exhibit a nearly trap free region close to Ec. For the
Al2O3/SiC interface, the highest trap density appears between 0.4 to 0.6 eV
below Ec. The results indicate the possibility for SiC-based MOSFETs with Al2O3
as the gate dielectric layer in future high performance devices.Comment: 3 figures. Applied Physics Letters, accepted for publicatio
The conceptualisation of health and disease in veterinary medicine
<p>Abstract</p> <p>Background</p> <p>The concept of health, as well as the concept of disease, is central in veterinary medicine. However, the definitions "health" and "disease" are not generally acknowledged by veterinarians. The aim of this study was to examine how the concepts "health" and "disease" are defined in veterinary textbooks.</p> <p>Methods</p> <p>Veterinary textbooks in several disciplines were investigated, but only textbooks with explicit definitions of the concepts were selected for examination.</p> <p>Results</p> <p>Eighty out of the 500 relevant books within veterinary medicine were written for non-veterinarians. Eight percent of the books had an explicit definition of health and/or disease. More frequently, textbooks written for non veterinarians did have definitions of health or disease, compared to textbooks written for professionals. A division of health definitions in five different categories was suggested, namely:</p> <p>1. Health as normality, 2. Health as biological function, 3. Health as homeostasis, 4. Health as physical and psychological well-being and 5. Health as productivity including reproduction.</p> <p>Conclusion</p> <p>Few veterinary textbooks had any health or disease definition at all. Furthermore, explicit definitions of health stated by the authors seemed to have little impact on how health and disease are handled within the profession. Veterinary medicine would probably gain from theoretical discussions about health and disease.</p
Patients' experiences of brief cognitive behavioral therapy for eating disorders: A qualitative investigation
Objective
Although it is important to analyze the effectiveness of new therapies, it is also necessary to consider how patients experience them. This is particularly important if we are to maximize treatment acceptability and reduce attrition. This study examined patient experiences of a new 10‐session cognitive‐behavioral therapy (CBT‐T), using a qualitative approach.
Method
The sample was 17 patients with a diagnosis of bulimia nervosa who had received CBT‐T (including treatment completers and non‐completers) within the previous 2 years. Sample size was determined by saturation of the emergent themes. Responses were analyzed using a six‐step thematic analysis process.
Results
Rated acceptability and effectiveness of CBT‐T were high. Five themes emerged, with subthemes. The key elements of patient experience of the therapy were: the therapeutic relationship; the nature of the therapy; its challenging but beneficial aspects; ending therapy; and the overall experience of CBT‐T (including comparison with other therapies).
Discussion
The findings build on the effectiveness research for CBT‐T, suggesting that it is an acceptable therapy that addresses many of the same themes that matter to patients as other therapies. The findings show that patients were positive about CBT‐T relative to other therapies, and offer suggestions as to how CBT‐T might be delivered to emphasize the importance of the time‐limited nature of the therapy
The effect of basic fibroblast growth factor on the blood flow and morphologic features of a latissimus dorsi cardiomyoplasty
AbstractPrevious studies designed to determine whether latissimus cardiomyoplasty could be used to revascularize ischemic myocardium showed that after operation the latissimus was ischemic and had severely deteriorated. This study was undertaken to determine whether basic fibroblast growth factor, a potent angiogenic peptide, would improve the vascularity of the latissimus and enhance collateral formation between the muscle of the cardiomyoplasty and ischemic myocardium. In goats, myocardial ischemia was induced with an ameroid constrictor and cardiomyoplasty performed. The latissimus was continuously stimulated electrically at 2 Hz for 6 weeks and given four weekly bolus injections of human recombinant basic fibroblast growth factor (80 μg infused into the left subclavian artery). In eight animals, rates of regional blood flow were measured and both the heart and latissimus were evaluated histochemically. The latissimus blood flow rate was 0.114 ± 0.029 ml/gm per minute, which was three times greater than that of historical controls (chronically stimulated latissimus cardiomyoplasty without basic fibroblast growth factor treatment; 0.042 ± 0.007 ml/gm per minute, p < 0.05). Associated with the improved blood flow, there was significantly less evidence of skeletal muscle fiber dropout and muscle fibrosis in the animals treated with basic fibroblast growth factor. Latissimus-derived collateral flow to ischemic myocardium developed in five of the eight goats and averaged 0.288 ± 0.075 ml/gm per minute. This flow was 42.8% ± 15.7% ( n = 5) of the flow required by normal myocardium (which was 0.728 ± 0.095 ml/gm per minute). This value for latissimus-derived collateral blood flow was almost twice that of the historical controls (24.0% ± 3.9%), but the increase did not achieve statistical significance ( p = 0.08). These results hold the promise that basic fibroblast growth factor treatment might enhance the formation of extramyocardial collaterals to the heart and improve skeletal muscle function. (J THORAC CARDIOVASC SURG 1996;111:19-28
Who should be prioritized for renal transplantation?: Analysis of key stakeholder preferences using discrete choice experiments
Background
Policies for allocating deceased donor kidneys have recently shifted from allocation based on Human Leucocyte Antigen (HLA) tissue matching in the UK and USA. Newer allocation algorithms incorporate waiting time as a primary factor, and in the UK, young adults are also favoured. However, there is little contemporary UK research on the views of stakeholders in the transplant process to inform future allocation policy. This research project aimed to address this issue.
Methods
Discrete Choice Experiment (DCE) questionnaires were used to establish priorities for kidney transplantation among different stakeholder groups in the UK. Questionnaires were targeted at patients, carers, donors / relatives of deceased donors, and healthcare professionals. Attributes considered included: waiting time; donor-recipient HLA match; whether a recipient had dependents; diseases affecting life expectancy; and diseases affecting quality of life.
Results
Responses were obtained from 908 patients (including 98 ethnic minorities); 41 carers; 48 donors / relatives of deceased donors; and 113 healthcare professionals. The patient group demonstrated statistically different preferences for every attribute (i.e. significantly different from zero) so implying that changes in given attributes affected preferences, except when prioritizing those with no rather than moderate diseases affecting quality of life. The attributes valued highly related to waiting time, tissue match, prioritizing those with dependents, and prioritizing those with moderate rather than severe diseases affecting life expectancy. Some preferences differed between healthcare professionals and patients, and ethnic minority and non-ethnic minority patients. Only non-ethnic minority patients and healthcare professionals clearly prioritized those with better tissue matches.
Conclusions
Our econometric results are broadly supportive of the 2006 shift in UK transplant policy which emphasized prioritizing the young and long waiters. However, our findings suggest the need for a further review in the light of observed differences in preferences amongst ethnic minorities, and also because those with dependents may be a further priority.</p
Individual quality assessment of autografting by probability estimation for clinical endpoints: a prospective validation study from the European group for blood and marrow transplantation.
The aim of supportive autografting is to reduce the side effects from stem cell transplantation and avoid procedure-related health disadvantages for patients at the lowest possible cost and resource expenditure. Economic evaluation of health care is becoming increasingly important. We report clinical and laboratory data collected from 397 consecutive adult patients (173 non-Hodgkin lymphoma, 30 Hodgkin lymphoma, 160 multiple myeloma, 7 autoimmune diseases, and 28 acute leukemia) who underwent their first autologous peripheral blood stem cell transplantation (PBSCT). We considered primary endpoints evaluating health economic efficacy (eg, antibiotic administration, transfusion of blood components, and time in hospital), secondary endpoints evaluating toxicity (in accordance with Common Toxicity Criteria), and tertiary endpoints evaluating safety (ie, the risk of regimen-related death or disease progression within the first year after PBSCT). A time-dependent grading of efficacy is proposed with day 21 for multiple myeloma and day 25 for the other disease categories (depending on the length of the conditioning regimen) as the acceptable maximum time in hospital, which together with antibiotics, antifungal, or transfusion therapy delineates four groups: favorable (≤7 days on antibiotics and no transfusions; ≤21 [25] days in hospital), intermediate (from 7 to 10 days on antibiotics and 7 days on antibiotics, >3 but 30/34 days in hospital after transplantation), and very unfavorable (>10 days on antibiotics, >6 transfusions; >30 to 34 days in hospital). The multivariate analysis showed that (1) PBSC harvests of ≥4 × 106/kg CD34 + cells in 1 apheresis procedure were associated with a favorable outcome in all patient categories except acute myelogenous leukemia and acute lymphoblastic leukemia (P = .001), (2) ≥5 × 106/kg CD34 + cells infused predicted better transplantation outcome in all patient categories (P 500 mL) (P = .002), and (5) patients with a central venous catheter during both collection and infusion of PBSC had a more favorable outcome post-PBSCT than peripheral access (P = .007). The type of mobilization regimen did not affect the outcome of auto-PBSCT. The present study identified predictive variables, which may be useful in future individual pretransplantation probability evaluations with the goal to improve supportive care
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