152 research outputs found
Influence of the disorder on tracer dispersion in a flow channel
Tracer dispersion is studied experimentally in periodic or disordered arrays
of beads in a capillary tube. Dispersion is measured from light absorption
variations near the outlet following a steplike injection of dye at the inlet.
Visualizations using dye and pure glycerol are also performed in similar
geometries. Taylor dispersion is dominant both in an empty tube and for a
periodic array of beads: the dispersivity increases with the P\'eclet
number respectively as and and is larger by a factor of 8
in the second case. In a disordered packing of smaller beads (1/3 of the tube
diameter) geometrical dispersion associated to the disorder of the flow field
is dominant with a constant value of reached at high P\'eclet numbers.
The minimum dispersivity is slightly higher than in homogeneous nonconsolidated
packings of small grains, likely due heterogeneities resulting from wall
effects. In a disordered packing with the same beads as in the periodic
configuration, is up to 20 times lower than in the latter and varies as
with or (depending on the fluid viscosity).
A simple model accounting for this latter result is suggested.Comment: available online at
http://www.edpsciences.org/journal/index.cfm?edpsname=epjap&niv1=contents&niv2=archive
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Potential small-scale development of western oil shale
Several studies have been undertaken in an effort to determine ways to enhance development of western oil shale under current market conditions for energy resources. This study includes a review of the commercial potential of western oil shale products and byproducts, a review of retorting processes, an economic evaluation of a small-scale commercial operation, and a description of the environmental requirements of such an operation. Shale oil used as a blend in conventional asphalt appears to have the most potential for entering today's market. Based on present prices for conventional petroleum, other products from oil shale do not appear competitive at this time or will require considerable marketing to establish a position in the marketplace. Other uses for oil shale and spent shale, such as for sulfur sorbtion, power generation, cement, aggregate, and soil stabilization, are limited economically by transportation costs. The three-state area area consisting of Colorado, Utah, and Wyoming seems reasonable for the entry of shale oil-blended asphalt into the commercial market. From a review of retorting technologies and the product characteristics from various retorting processes it was determined that the direct heating Paraho and inclined fluidized-bed processes produce a high proportion of heavy material with a high nitrogen content. The two processes are complementary in that they are each best suited to processing different size ranges of materials. An economic evaluation of a 2000-b/d shale oil facility shows that the operation is potentially viable, if the price obtained for the shale oil residue is in the top range of prices projected for this product. Environmental requirements for building and operating an oil shale processing facility are concerned with permitting, control of emissions and discharges, and monitoring. 62 refs., 6 figs., 10 tabs
parkin-induced defects in neurophysiology and locomotion are generated by metabolic dysfunction and not oxidative stress
Parkinson's disease (PD) is characterized by movement disorders, including bradykinesia. Analysis of inherited, juvenile PD, identified several genes linked via a common pathway to mitochondrial dysfunction. In this study, we demonstrate that the larva of the Drosophila parkin mutant faithfully models the locomotory and metabolic defects of PD and is an excellent system for investigating their inter-relationship. parkin larvae displayed a marked bradykinesia that was caused by a reduction in both the frequency of peristalsis and speed of muscle contractions. Rescue experiments confirmed that this phenotype was due to a defect in the nervous system and not in the muscle. Furthermore, recordings of motoneuron activity in parkin larvae revealed reduced bursting and a striking reduction in evoked and miniature excitatory junction potentials, suggesting a neuronal deficit. This was supported by our observations in parkin larvae that the resting potential was depolarized, oxygen consumption and ATP concentration were drastically reduced while lactate was increased. These findings suggest that neuronal mitochondrial respiration is severely compromised and there is a compensatory switch to glycolysis for energy production
Randomised crossover trial of telemonitoring in chronic respiratory patients (TeleCRAFT trial).
OBJECTIVE: To assess the impact of home telemonitoring on health service use and quality of life in patients with severe chronic lung disease. DESIGN: Randomised crossover trial with 6 months of standard best practice clinical care (control group) and 6 months with the addition of telemonitoring. PARTICIPANTS: 68 patients with chronic lung disease (38 with COPD; 30 with chronic respiratory failure due to other causes), who had a hospital admission for an exacerbation within 6 months of randomisation and either used long-term oxygen therapy or had an arterial oxygen saturation (SpO2) of <90% on air during the previous admission. Individuals received telemonitoring (second-generation system) via broadband link to a hospital-based care team. OUTCOME MEASURES: Primary outcome measure was time to first hospital admission for an acute exacerbation. Secondary outcome measures were hospital admissions, general practitioner (GP) consultations and home visits by nurses, quality of life measured by EuroQol-5D and hospital anxiety and depression (HAD) scale, and self-efficacy score (Stanford). RESULTS: Median (IQR) number of days to first admission showed no difference between the two groups-77 (114) telemonitoring, 77.5 (61) control (p=0.189). Hospital admission rate at 6 months increased (0.63 telemonitoring vs 0.32 control p=0.026). Home visits increased during telemonitoring; GP consultations were unchanged. Self-efficacy fell, while HAD depression score improved marginally during telemonitoring. CONCLUSIONS: Telemonitoring added to standard care did not alter time to next acute hospital admission, increased hospital admissions and home visits overall, and did not improve quality of life in chronic respiratory patients. TRIAL REGISTRATION NUMBER: NCT02180919 (ClinicalTrials.gov)
Medicine is patriarchal, but alternative medicine is not the answer
Women are over-represented within alternative medicine, both as consumers and as service providers. In this paper, I show that the appeal of alternative medicine to women relates to the neglect of women’s health needs within scientific medicine. This is concerning because alternative medicine is severely limited in its therapeutic effects; therefore, those who choose alternative therapies are liable to experience inadequate healthcare. I argue that while many patients seek greater autonomy in alternative medicine, the absence of an evidence base and plausible mechanisms of action leaves patients unable to realize meaningful autonomy. This seems morally troubling, especially given that the neglect of women’s needs within scientific medicine seems to contribute to preferences for alternative medicine. I conclude that the liberatory credentials of alternative medicine should be questioned and make recommendations to render scientific medicine better able to meet the needs of typical alternative medicine consumers
Social meanings and understandings in patient-nurse interaction in the community practice setting: a grounded theory study
Provisional: Background: The patient-nurse relationship is a traditional concern of healthcare research. However, patient-nurse interaction is under examined from a social perspective. Current research focuses mostly on specific contexts of care delivery and experience related to medical condition or illness, or to nurses' speciality. Consequentially, this paper is about the social meanings and understandings at play within situated patient-nurse interaction in the community practice setting in a transforming healthcare service. Methods: Grounded theory methodology was used and the research process was characterised by principles of theoretical sensitivity and constant comparative analysis. The field of study was four health centres in the community. The participants were patients and nurses representative of those attending or working in the health centres and meeting there by scheduled appointment. Data collection methods were observations, informal interviews and semi-structured interviews. Results: Key properties of 'Being a good patient, being a good nurse', 'Institutional experiences' and 'Expectations about healthcare' were associated with the construction of a category entitled 'Experience'. Those key properties captured that in an evolving healthcare environment individuals continually re-constructed their reality of being a patient or nurse as they endeavoured to perform appropriately; articulation of past and present healthcare experiences was important in that process. Modus operandi in role as patient was influenced by past experiences in healthcare and by those in non-healthcare institutions in terms of engagement and involvement (or not) in interaction. Patients' expectations about interaction in healthcare included some uncertainly as they strived to make sense of the changing roles and expertise of nurses and, differentiating between the roles and expertise of nurses and doctors. Conclusions: The importance of social meanings and understandings in patient-nurse interaction is not fully apparent to nurses, but important in the patient experience. Seeking understanding from a social perspective makes a contribution to enhancing knowledge about patient-nurse interaction with subsequent impact on practice, in particular the development of the patient-nurse relationship. The implications are that the meanings and understandings patients and nurses generate from experiences beyond and within their situated interaction are pivotal to the development of their relationship in the transforming community healthcare environment
Nurse-patient interaction and communication: a systematic literature review
Aim: The purpose of this review is to describe the use and definitions of the concepts of nurse-patient interaction and nurse-patient communication in nursing literature. Furthermore, empirical findings of nurse-patient communication research will be presented, and applied theories will be shown. Method: An integrative literature search was executed. The total number of relevant citations found was 97. The search results were reviewed, and key points were extracted in a standardized form. Extracts were then qualitatively summarized according to relevant aspects and categories for the review. Results: The relation of interaction and communication is not clearly defined in nursing literature. Often the terms are used interchangeably or synonymously, and a clear theoretical definition is avoided or rather implicit. Symbolic interactionism and classic sender-receiver models were by far the most referred to models. Compared to the use of theories of adjacent sciences, the use of original nursing theories related to communication is rather infrequent. The articles that try to clarify the relation of both concepts see communication as a special or subtype of interaction. Conclusion: The included citations all conclude that communication skills can be learned to a certain degree. Involvement of patients and their role in communication often is neglected by authors. Considering the mutual nature of communication, patients’ share in conversation should be taken more into consideration than it has been until now. Nursing science has to integrate its own theories of nursing care with theories of communication and interaction from other scientific disciplines like sociology
Pompe disease diagnosis and management guideline
ACMG standards and guidelines are designed primarily as an educational resource for physicians and other health care providers to help them provide quality medical genetic services. Adherence to these standards and guidelines does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. in determining the propriety of any specific procedure or test, the geneticist should apply his or her own professional judgment to the specific clinical circumstances presented by the individual patient or specimen. It may be prudent, however, to document in the patient's record the rationale for any significant deviation from these standards and guidelines.Duke Univ, Med Ctr, Durham, NC 27706 USAOregon Hlth Sci Univ, Portland, OR 97201 USANYU, Sch Med, New York, NY USAUniv Florida, Coll Med, Powell Gene Therapy Ctr, Gainesville, FL 32611 USAIndiana Univ, Bloomington, in 47405 USAUniv Miami, Miller Sch Med, Coral Gables, FL 33124 USAHarvard Univ, Childrens Hosp, Sch Med, Cambridge, MA 02138 USAUniversidade Federal de São Paulo, São Paulo, BrazilColumbia Univ, New York, NY 10027 USANYU, Bellevue Hosp, Sch Med, New York, NY USAColumbia Univ, Med Ctr, New York, NY 10027 USAUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
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