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Sample records for clinical quatitative flow

  1. The Clinical Assessment of Intraventricular Flows

    Science.gov (United States)

    Bermejo, Javier; Martínez-Legazpi, Pablo; del Álamo, Juan C.

    2015-01-01

    Recent advances in imaging techniques have allowed physicians to obtain robust measurements of intracardiac flows in the clinical setting. Consequently, the physiological implications of intraventricular fluid dynamics are beginning to be understood. Initial data show that these flows involve complex fluid-structure interactions and mixing phenomena that are modified by disease. Here we critically review the most important aspects of intraventricular fluid mechanics relevant for clinical applications. We discuss current image and numerical methods for assessing intraventricular flows, as well as implemented approaches to analyze their impact on cardiac function. The physiological and clinical insights provided by such techniques are discussed both in health and in disease. The final goal is to encourage research in the application of fluid dynamic foundations to patient-based clinical data. A huge potential is anticipated not only in terms of the basic science of large-scale biological systems, but also in practical terms of improving patient care.

  2. Clinical relevance of intermittent tumour blood flow

    International Nuclear Information System (INIS)

    One of the goals of translational cancer research is to understand basic 'phenomena' so that tumour response to therapy can be improved. One such phenomenon is intermittent tumour blood flow. The impact of the transient hypoxia that results from decreased tumour blood flow is now beginning to be appreciated in preclinical systems, and also receiving some attention in clinical practise. Thus in this article we review the nature and frequency of microregional blood flow changes in preclinical and clinical tumours and examine the impact of those changes on response to both radiotherapy and chemotherapy. Additionally, the implications of non-constant blood flow for both the growth of the unperturbed tumour and the regrowth of surviving tumour clonogens during and after therapy are examined

  3. A clinical flow cytometry data analysis assistant

    Energy Technology Data Exchange (ETDEWEB)

    Salzman, G.C. (Los Alamos National Lab., NM (USA)); Stewart, C.C. (Roswell Park Cancer Inst., Buffalo, NY (USA)); Duque, R.E. (Norwood Clinic, Birmingham, AL (USA)); Braylan, R.C. (Florida Univ., Gainesville, FL (USA). Coll. of Medicine)

    1990-01-01

    A rule-based expert system is being developed to assist clinicians in the analysis of multivariate flow cytometry data for patients with leukemias or lymphomas. The cells are stained with fluorescently labeled monoclonal antibodies and the cell fluorescence is measured with a flow cytometer. Cluster analysis is used to isolate subpopulations in the data on which the clinical decisions are made. Symbolic facts for the expert system are instantiated using these numerical data and the knowledge of the clinicians and experts in flow cytometry. The first prototype used a decision tree and rigid rules. Is successfully classified only nine of eleven leukemia cases. A second prototype incorporating certainty factors into the rules is now being developed that should remove the need for a rigid decision tree. 9 refs.

  4. Cerebral blood flow: Physiologic and clinical aspects

    International Nuclear Information System (INIS)

    This book contains 46 chapters divided among nine sections. The section titles are: Historical Perspectives; Cerebrovascular Anatomy; Cerebrovascular Physiology; Methods of Clinical Measurement; Experimental Methods; Imaging of Cerebral Circulation; Cerebrovascular Pathophysiology; Cerebrovascular Pharmacology; and Surgical and Interventional Augmentation

  5. Flow Analysis of the Cleveland Clinic Centrifugal Pump

    Science.gov (United States)

    Veres, Joseph P.; Golding, Leonard A. R.; Smith, William A.; Horvath, David; Medvedev, Alexander

    1997-01-01

    An implantable ventricular assist rotordynamic blood pump is being developed by the Cleveland Clinic Foundation in cooperation with the NASA Lewis Research Center. At the nominal design condition, the pump provides blood flow at the rate of 5 liters per minute at a pressure rise of 100 mm of mercury and a rotative speed of 3000 RPM. Bench testing of the centrifugal pump in a water/glycerin mixture has provided flow and pressure data at several rotative speeds. A one-dimensional empirical based pump flow analysis computer code developed at NASA Lewis Research Center has been used in the design process to simulate the flow in the primary centrifugal pump stage. The computer model was used to size key impeller and volute geometric parameters that influence pressure rise and flow. Input requirements to the computer model include a simple representation of the pump geometry. The model estimates the flow conditions at the design and at off-design operating conditions at the impeller leading and trailing edges and the volute inlet and exit. The output from the computer model is compared to flow and pressure data obtained from bench testing.

  6. Clinical studies on cerebral blood flow in chronic subdural hematoma

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF) and clinical symptoms were examined between pre- and post-operations in twenty-four patients with unilateral chronic subdural hematoma. The following results were obtained by intravenous 133Xe method : 1. There was a reducing tendency of the CBF (hemisphere) on hematoma side, in most cases. While, the groups of headache and disturbances of consciousness did not give a laterality between hematoma and opposite side without the group of hemiparesis. 2. The absolute values of the CBF in the groups of headache and disturbances of consciousness were correlated with the clinical symptoms. In the group of hemiparesis, the laterality between hematoma and opposite side was correlated with the clinical symptoms. 3. In the group of hemiparesis, the F-flow (fast-flow) had sensitive reaction more than the ISI (initial slope index) with symptomatic improvement. 4. It was found that there was not an increase in the absolute value of the CBF, which was under the normal limit between pre- and post-operations in the case without improvement. By SPECT (Method of IMP), the following results were obtained : 1. There was the area of defect at the location of hematoma and the CBF tended to reduce at the subcortical white matter and at the basal ganglia of hematoma side. 2. The CBF of the contralateral hematoma side in the hemisphere of cerebellum was also tended to reduce. (author)

  7. Regional cerebral blood flow in psychiatry: Application to clinical research

    International Nuclear Information System (INIS)

    In the following sections, the authors describe aspects of the xenon-133 inhalation technique as it has been modified in their lab, as well as a number of considerations and prerequisites for setting up such a facility. The authors also discuss the processes by which they technically and clinically validated the methods used. Several case studies follow along with descriptions of the approaches they are taking in investigating psychiatric illnesses with rCBF. Since the concept of a relation between brain functional activity, metabolism, and blood flow has a long history, both in theory and in practice, they first briefly review some of this history and some of the principles involved

  8. Improving patient flow at a family health clinic.

    Science.gov (United States)

    Bard, Jonathan F; Shu, Zhichao; Morrice, Douglas J; Wang, Dongyang Ester; Poursani, Ramin; Leykum, Luci

    2016-06-01

    This paper presents an analysis of a residency primary care clinic whose majority of patients are underserved. The clinic is operated by the health system for Bexar County and staffed primarily with physicians in a three-year Family Medicine residency program at The University of Texas School of Medicine in San Antonio. The objective of the study was to obtain a better understanding of patient flow through the clinic and to investigate changes to current scheduling rules and operating procedures. Discrete event simulation was used to establish a baseline and to evaluate a variety of scenarios associated with appointment scheduling and managing early and late arrivals. The first steps in developing the model were to map the administrative and diagnostic processes and to collect time-stamped data and fit probability distributions to each. In conjunction with the initialization and validation steps, various regressions were performed to determine if any relationships existed between individual providers and patient types, length of stay, and the difference between discharge time and appointment time. The latter two statistics along with resource utilization and closing time were the primary metrics used to evaluate system performance.The results showed that up to an 8.5 % reduction in patient length of stay is achievable without noticeably affecting the other metrics by carefully adjusting appointment times. Reducing the no-show rate from its current value of 21.8 % or overbooking, however, is likely to overwhelm the system's resources and lead to excessive congestion and overtime. Another major finding was that the providers are the limiting factor in improving patient flow. With an average utilization rate above 90 % there is little prospect in shortening the total patient time in the clinic without reducing the providers' average assessment time. Finally, several suggestions are offered to ensure fairness when dealing with out-of-order arrivals. PMID:25155098

  9. High-throughput flow cytometry data normalization for clinical trials.

    Science.gov (United States)

    Finak, Greg; Jiang, Wenxin; Krouse, Kevin; Wei, Chungwen; Sanz, Ignacio; Phippard, Deborah; Asare, Adam; De Rosa, Stephen C; Self, Steve; Gottardo, Raphael

    2014-03-01

    Flow cytometry datasets from clinical trials generate very large datasets and are usually highly standardized, focusing on endpoints that are well defined apriori. Staining variability of individual makers is not uncommon and complicates manual gating, requiring the analyst to adapt gates for each sample, which is unwieldy for large datasets. It can lead to unreliable measurements, especially if a template-gating approach is used without further correction to the gates. In this article, a computational framework is presented for normalizing the fluorescence intensity of multiple markers in specific cell populations across samples that is suitable for high-throughput processing of large clinical trial datasets. Previous approaches to normalization have been global and applied to all cells or data with debris removed. They provided no mechanism to handle specific cell subsets. This approach integrates tightly with the gating process so that normalization is performed during gating and is local to the specific cell subsets exhibiting variability. This improves peak alignment and the performance of the algorithm. The performance of this algorithm is demonstrated on two clinical trial datasets from the HIV Vaccine Trials Network (HVTN) and the Immune Tolerance Network (ITN). In the ITN data set we show that local normalization combined with template gating can account for sample-to-sample variability as effectively as manual gating. In the HVTN dataset, it is shown that local normalization mitigates false-positive vaccine response calls in an intracellular cytokine staining assay. In both datasets, local normalization performs better than global normalization. The normalization framework allows the use of template gates even in the presence of sample-to-sample staining variability, mitigates the subjectivity and bias of manual gating, and decreases the time necessary to analyze large datasets. PMID:24382714

  10. Coronary Slow Flow Phenomenon Clinical Findings and Predictors

    Science.gov (United States)

    Sanati, Hamidreza; Kiani, Reza; Shakerian, Farshad; Firouzi, Ata; Zahedmehr, Ali; Peighambari, Mohammadmehdi; Shokrian, Leila; Ashrafi, Peiman

    2016-01-01

    Background: In some patients with chest pain, selective coronary angiography reveals slow contrast agent passage through the epicardial coronary arteries in the absence of stenosis. This phenomenon has been designated the slow coronary flow (SCF) phenomenon. Objectives: In this study, we aimed to describe the demographic and clinical findings and presence of common atherosclerosis risk factors in patients with the SCF phenomenon. Patients and Methods: Between October 2014 and March 2015, demographic data, clinical histories, atherosclerosis risk factors, and laboratory and angiographic findings were recorded for all consecutive patients scheduled for coronary angiography and diagnosed with the SCF phenomenon, as well as a control group (patients with normal epicardial coronary arteries; NECA). SCF was diagnosed based on the thrombolysis in myocardial infarction frame count (TFC). A TFC > 27 indicated a diagnosis of SCF phenomenon. Results: Among the 3600 patients scheduled for selective coronary angiography, 75 (2%) met the SCF criteria. SCF and NECA patients did not exhibit statistically significant differences in traditional risk factors except for hypertension, which was more prevalent in SCF than NECA patients (52% versus 31%, P = 0.008). A multivariable analysis indicated a low body mass index, presence of hypertension, low high-density lipoprotein cholesterol (HDL-c) level, and high hemoglobin level as independent predictors of the SCF phenomenon; of these, hypertension was the strongest predictor (odds ratio = 6.3, 95% confidence interval: 2.2 - 17.9, P = 0.001). Conclusions: The SCF phenomenon is relatively frequent, particularly among patients with acute coronary syndrome who are scheduled for coronary angiography. Hypertension, a low HDL-c level, and high hemoglobin level can be considered independent predictors of this phenomenon. PMID:26889458

  11. [Application of Flow Cytometry in Clinical Laboratories and Its Future Direction, Focusing Upon Multicolor Flow Cytometry].

    Science.gov (United States)

    Hayashida, Masahiko

    2015-07-01

    Flow cytometry (FCM) has been introduced into clinical laboratories to determine the lineage and functional stage of differentiation of hematopoietic tumor cells using multiple immunophenotypic markers. Multi-parametric analysis, which simultaneously measures multiple cellular characteristics, not only provides a large amount of novel information for each sample studied, but also requires a reduced volume of the specimen and avoids redundancies of reagents within antibody panels. Through a series of novel developments in FCM hardware, software, and dye-chemistry, recently developed multicolor flow cytometers are capable of detecting 10 or more fluorochromes simultaneously and expeditiously, taking advantage of not only cluster analysis but also detecting rare cellular populations within complex materials. In this study, we applied the multicolor FCM technology for: i) T-cell lineage assessment in early T-cell precursor acute lymphoblastic leukemia, ii) detection of a rare neoplastic population in angioimmunoblastic T-cell lymphoma composed of a complex mixture of cells, iii) assessment of bone marrow infiltration of B-cell lymphoma, and iv) sensitive detection of multiple myeloma cells with the use of a combination of antibodies, which is applicable to monitoring the response to treatment. PMID:26591434

  12. A CLIPS expert system for clinical flow cytometry data analysis

    Science.gov (United States)

    Salzman, G. C.; Duque, R. E.; Braylan, R. C.; Stewart, C. C.

    1990-01-01

    An expert system is being developed using CLIPS to assist clinicians in the analysis of multivariate flow cytometry data from cancer patients. Cluster analysis is used to find subpopulations representing various cell types in multiple datasets each consisting of four to five measurements on each of 5000 cells. CLIPS facts are derived from results of the clustering. CLIPS rules are based on the expertise of Drs. Stewart, Duque, and Braylan. The rules incorporate certainty factors based on case histories.

  13. 21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continuous flow sequential multiple chemistry analyzer for clinical use. 862.2150 Section 862.2150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND...

  14. Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography

    International Nuclear Information System (INIS)

    The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability

  15. Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hemmingsen, R.; Vorstrup, S.; Clemmesen, L.; Holm, S.; Tfelt-Hansen, P.; Sorensen, A.S.; Hansen, C.; Sommer, W.; Bolwig, T.G.

    1988-11-01

    The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability.

  16. Management of Low-Flow Vascular Malformations: Clinical Presentation, Classification, Patient Selection, Imaging and Treatment

    International Nuclear Information System (INIS)

    This review article aims to give an overview of the current state of imaging, patient selection, agents and techniques used in the management of low-flow vascular malformations. The review includes the current classifications for low-flow vascular malformations including the 2014 updates. Clinical presentation and assessment is covered with a detailed section on the common sclerosant agents used to treat low-flow vascular malformations, including dosing and common complications. Imaging is described with a guide to a simple stratification of the use of imaging for diagnosis and interventional techniques

  17. Management of Low-Flow Vascular Malformations: Clinical Presentation, Classification, Patient Selection, Imaging and Treatment

    Energy Technology Data Exchange (ETDEWEB)

    McCafferty, Ian, E-mail: ian.mccafferty@uhb.nhs.uk [Queen Elizabeth Hospital Birmingham (QEHB) & Birmingham Children’s Hospital (BCH) (United Kingdom)

    2015-10-15

    This review article aims to give an overview of the current state of imaging, patient selection, agents and techniques used in the management of low-flow vascular malformations. The review includes the current classifications for low-flow vascular malformations including the 2014 updates. Clinical presentation and assessment is covered with a detailed section on the common sclerosant agents used to treat low-flow vascular malformations, including dosing and common complications. Imaging is described with a guide to a simple stratification of the use of imaging for diagnosis and interventional techniques.

  18. The clinical study of cerebral blood flow imaging in patients with early syphilis

    International Nuclear Information System (INIS)

    Objective: To study the clinical value of cerebral blood flow imaging for evaluation of patients with early syphilis. Methods: Fifty-three patients with early syphilis underwent cerebral blood flow imaging using 99Tcm-ethylenecysteinate dimer(ECD). Regional cerebral blood flow (rCBF) changes were analyzed. Results: The acquired images of 53 patients were graded as 5 types. The rCBF was significantly depressed in 48 of 53 patients mainly in the areas dominated by anterior cerebral artery and middle cerebral artery. Conclusion: Treponema pallidum (TP) could start invading central nervous system at the early stage of infection

  19. Effects of blood flow control on clinical outcomes after ethanolamine oleate sclerotherapy for vascular malformations

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the control of nidus blood flow and the association between such control and clinical outcomes after ethanolamine oleate (EO) sclerotherapy for vascular malformations. Morphological grades on magnetic resonance (MR) images (grades 1-3), preprocedure nidus blood flow control, and clinical results in 22 cases of vascular malformation were reviewed. Cases were subdivided by MR morphological grade as follows: grade 1, 3 patients; grade 2A, 6 patients; grade 3, 13 patients. Responses to EO sclerotherapy were as follows: excellent, 3 patients; good, 5 patients; poor, 14 patients. An excellent response was achieved in one grade 1 case, one grade 2A case, and one grade 3 case. Preprocedure nidus flow was controlled in 8 lesions (type A) and not controlled in 14 lesions (type B). Three (37.5%) type A lesions had an excellent response, five had a good response; and none had a poor response. All type B lesions had a poor response. Flow control predicted an excellent result (P<0.05). Preprocedure nidus blood flow control (versus lack of control) is associated with a significantly higher incidence of favorable clinical responses to EO sclerotherapy for vascular malformations. (author)

  20. Clinical application of a rapid flow-cytometric immunofluorescence method for studing lymphocyte subsets

    International Nuclear Information System (INIS)

    In this study, we report a clinical application of a rapid flow-cytometric immunofluorescence method for studing lymphocyte subsets in whole blood by using fluorescein-conjugated monoclonal antibodies OKT 3, OKT 4, OKT 8, OKI a 1, OKT 6, OKT 11, OKT 9, OKT 10 and OKM 1. Changes in the relative percentages and absolute counts of various lymphocyte subsets during radiotherapy of cancer patients were evaluated by this method. (author)

  1. A new radioisotope method of measuring flow rate of aqueous humour in clinical practice

    International Nuclear Information System (INIS)

    The first clinical experiences are described with measurements of the intraocular fluid flow by means of contactly applied 22NaCl and external gamma rays detectors. In various types of glaucoma considerable differences in the speed of the intraocular fluid outflow have been observed. Half-time of outflow in open angle glaucoma was significantly prolonged in corellation with the increasing age of patients. Half-time of the outflow was markedly accelerated after the performed fistulizing antiglaucomatous operations. (author)

  2. Clinical importance of hyperemic coronary blood flow (thrombolysis in myocardial infarction-intravenous flow) after primary percutaneous coronary intervention.

    Science.gov (United States)

    Karakoyun, Süleyman; Tanboga, Ibrahim Halil; Kurt, Mustafa; Aksakal, Enbiya; Kaya, Ahmet; Isik, Turgay; Ekinci, Mehmet; Sevimli, Serdar; Acikel, Mahmut

    2014-10-01

    We aimed to investigate clinical, demographic and angiographic factors associated with hyperemic coronary blood flow (HCBF) and the relation of HCBF with mortality at 30 days. Our study included 809 consecutive patients with acute ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention (PCI). We divided corrected thrombolysis in myocardial infarction (TIMI) frame count (TFC) values into three tertiles: less than 14, 14-28 and more than 28. Corrected TFC less than 14 was defined as HCBF or TIMI intravenous flow. The primary end-point of the present study was all-cause mortality within 30 days. Among the HCBF group (n = 58), the patients with poor myocardial perfusion demonstrated the highest mortality rate within the 30-day follow-up period (33%). Low TIMI myocardial perfusion grade, history of no smoking, left ventricular ejection fraction (LVEF), and high Killip status and low LVEF were found to be independently associated with 1-month all-cause mortality. The present study showed that HCBF after primary PCI has a high 30-day mortality when associated with impaired reperfusion. PMID:24842315

  3. [Clinical application and experimental studies of the pulsed inhaled nitric oxide flow controlling instrument].

    Science.gov (United States)

    Mo, Xu-ming; Zhao, En-chun; Wang, Min-sheng; Gu, Xinglin; Wang, Zhenxi; Wang, Chunsheng

    2002-01-01

    A flow controlling system for pulsed inhaled nitric oxide has been developed and tested, and here its features and initial animal experiments and clinical applications are described. The physical characteristic test indicates that the practical released dose of NO gas is very close to the theoretical flow of NO gas at variant pressures. Animal experiments demonstrate that inhaled NO gas concentration is lower than the concentration of theoretical inhalation, but the variance is not remarkable (p>0.05). When sixteen cases with CHD and PH were chosen to inhale NO gas (15 ppm, 15 min) PAP and PVR of all cases were reduced after inhalation of NO gas from 617 +/-51.3 dyn x s x cm(-5), 54.4+/-13.1 mmHg to 417+/-36.9 dym x s x cm(-5), 33.8+/-12.3 mmHg (PVR, p<0.01; PAP, p<0.01) respectively. When gas inhalation was stopped, these values returned to their base lines after a short period of time. All these show that the pulsed inhaled NO flow controlling instrument in accordance with the requirements of the designing, can be widely used in clinical diagnoses and treatments and will be a new tool offered for the treatments of the patients with PH. PMID:16104155

  4. Immune Monitoring in Cancer Vaccine Clinical Trials: Critical Issues of Functional Flow Cytometry-Based Assays

    Directory of Open Access Journals (Sweden)

    Iole Macchia

    2013-01-01

    Full Text Available The development of immune monitoring assays is essential to determine the immune responses against tumor-specific antigens (TSAs and tumor-associated antigens (TAAs and their possible correlation with clinical outcome in cancer patients receiving immunotherapies. Despite the wide range of techniques used, to date these assays have not shown consistent results among clinical trials and failed to define surrogate markers of clinical efficacy to antitumor vaccines. Multiparameter flow cytometry- (FCM- based assays combining different phenotypic and functional markers have been developed in the past decade for informative and longitudinal analysis of polyfunctional T-cells. These technologies were designed to address the complexity and functional heterogeneity of cancer biology and cellular immunity and to define biomarkers predicting clinical response to anticancer treatment. So far, there is still a lack of standardization of some of these immunological tests. The aim of this review is to overview the latest technologies for immune monitoring and to highlight critical steps involved in some of the FCM-based cellular immune assays. In particular, our laboratory is focused on melanoma vaccine research and thus our main goal was the validation of a functional multiparameter test (FMT combining different functional and lineage markers to be applied in clinical trials involving patients with melanoma.

  5. Laser speckle contrast imaging of cerebral blood flow in humans during neurosurgery: a pilot clinical study

    Science.gov (United States)

    Parthasarathy, Ashwin B.; Weber, Erica L.; Richards, Lisa M.; Fox, Douglas J.; Dunn, Andrew K.

    2010-11-01

    Monitoring cerebral blood flow (CBF) during neurosurgery can provide important physiological information for a variety of surgical procedures. CBF measurements are important for assessing whether blood flow has returned to presurgical baseline levels and for assessing postsurgical tissue viability. Existing techniques for intraoperative monitoring of CBF based on magnetic resonance imaging are expensive and often impractical, while techniques such as indocyanine green angiography cannot produce quantitative measures of blood flow. Laser speckle contrast imaging (LSCI) is an optical technique that has been widely used to quantitatively image relative CBF in animal models in vivo. In a pilot clinical study, we adapted an existing neurosurgical operating microscope to obtain LSCI images in humans in real time during neurosurgery under baseline conditions and after bipolar cautery. Simultaneously recorded ECG waveforms from the patient were used to develop a filter that helped reduce measurement variabilities due to motion artifacts. Results from this study demonstrate the feasibility of using LSCI to obtain blood flow images during neurosurgeries and its capability to produce full field CBF image maps with excellent spatial resolution in real-time with minimal disruption to the surgical procedure.

  6. INCIDENCE OF SUB - CLINICAL AIRFLOW OBSTRUCTION IN APPARENTLY HEALTHY MEDICAL PERSONNEL; DIAGNOSIS AND COMPARISION BY SPIROMETRY AND PEAK FLOW METRY

    OpenAIRE

    Subba Rao; Aruna; Sateesh Kumar; Neethi Chandra

    2015-01-01

    AIM & OBJE CTIVES OF THE STUDY: To diagnose sub - clinical airflow obstruction in apparently healthy medical personnel, and to compare Peak Expiratory Flow Rate (PEFR) by using Spirometry and by Wright’s peak flow meter. METHODOLOGY: About 80 apparently healthy medical students including Post Graduates, internees and medical technicians were taken in ...

  7. Improved graft survival in highly sensitized patients undergoing renal transplantation after the introduction of a clinically validated flow cytometry crossmatch.

    LENUS (Irish Health Repository)

    Limaye, Sandhya

    2009-04-15

    Flow cytometric techniques are increasingly used in pretransplant crossmatching, although there remains debate regarding the clinical significance and predictive value of donor-specific antibodies detected by flow cytometry. At least some of the discrepancies between published studies may arise from differences in cutoffs used and lack of standardization of the test.

  8. Experimental and clinical studies of hepatic blood flow evaluation by dynamic CT

    International Nuclear Information System (INIS)

    Dynamic CT of the liver were applied to a method of hepatic blood flow evaluation. The timedensity curve of the liver and the aorta after intravenous bolus injection of contrast medium were evaluated, devising a new potential index for a relative liver blood flow from the aorta (Aorto-Hepatic (A-H) ratio); hepatic peak density was expressed as percentage to aortic peak density and was divided by the peak time difference between the aorta and the liver. In experimental studies, two animal models for decreased hepatic blood flow were prepared, one with hepatic arterial embolization and the other with superior mesenteric vein ligation. The A-H ratios in both groups were well correlated to the decrease of blood flow of the liver, indicating that the A-H ratio could express not only the arterial but also the portal blood flow. In clinical studies, dynamic CT scans were performed in 69 patients, including 50 cases of the liver cirrhosis with hepatoma, 10 cases of liver cirrhosis and 9 cases of normal liver. The A-H ratio of normal liver was 0.63 ± 0.11, while in cirrhosis the ratio was 0.21 ± 0.06 and cirrhosis with hepatoma the ratio was 0.27 ± 0.09. The ratio was well correlated to the degrees of the diseases, and also the ratio was correlated to the hepatic function reserve in some degrees. From this results, it was strongly suggested that the A-H ratio would become an useful index of blood perfusion to the liver parenchyma, providing adjunctive parameter to determine resectability of the liver, indication for hepatic arterial embolization, or evaluation of the course of chronic liver diseases. (author)

  9. DETECTION OF PLATELET-DERIVED MICROPARTICLES USING FLOW CYTOMETRY AND ITS CLINICAL APPLICATION

    Institute of Scientific and Technical Information of China (English)

    崔巍; 马文新; 韩晔华; 林其燧

    2003-01-01

    Objective.To establish a flow cytometric internal standard method for counting platelet-derived microparti-cles(PMPs)and to study its clinical significance. Methods. PMPs suspension(platelet poor plasma,PPP) was extracted by gradual centrifugation. According to the size of PMPs,3 μm and 0.8μm latex beads were used as internal standards for the quantitation. PMPs were counted by adjusting flow cytometric discrimination and voltage of forward scatter and side scatter. Results. In 30 healthy donors,the average concentration of resting PMPs was(1.2×105±5.7×104 )/ml and that of activated PMPs was(1.6×106±9.1×105)/ml. Compared with healthy donors,PMPs mean value was significantly higher(P0.05)] .Conclusions. PMPs is a useful indicator in monitoring platelet activation,and plays an important role in thrombotic disease. By flow cytometric internal standard method,PMPs can be counted rapidly and accurately,which may be very helpful in interlaboratory comparative studies.

  10. Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

    Science.gov (United States)

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

    In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. PMID:27245647

  11. Lactate solid-state biosensor with multilayer of electrodeposited polymers for flow-injection clinical analysis.

    Science.gov (United States)

    Krawczyñski vel Krawczyk, T; Trojanowicz, M; Lewenstam, M; Moszczynska, A

    1996-01-01

    In the lactate biosensor, electrodeposited poly(o-phenylenediamine) serves as a convenient matrix for the immobilization of lactate oxidase, but does not provide sufficient discrimination from several interfering species present in physiological fluids. Their effect, however, can be eliminated by additional modification of the working Pt electrode with a bilayer of electrodeposited polypyrrole/polyphenol. Despite continued decrease in biosensor sensitivity, the newly developed three-layer solid-state biosensor was successfully applied in flow-injection determination of lactate in both undiluted and diluted human blood serum samples over a 10 day period. For the lactate concentration range 0.2-5.0 mM in several series of measurements the correlation coefficient values for comparison with photometric determination using a DuPont dimension clinical analyzer were between 0.96 and 0.99. The reproducibility measured for 1:10 diluted serum was 0.6%. The detection limit was estimated as 2 microM. PMID:8828166

  12. Clinical effect of Diskus dry-powder inhaler at low and high inspiratory flow-rates in asthmatic children

    DEFF Research Database (Denmark)

    Nielsen, K G; Auk, I L; Bojsen, K;

    1998-01-01

    In vitro studies with the Diskus inhaler at low and high flow rates show consistent doses of drug as fine particles <4.7 microm. The present study was designed to ascertain whether this in vitro flow independency translates into flow-independent clinical effect when the device is used by patients...... at low (30 L x min[-1]) and high (90 L x min[-1]) flow rates. A pilot study in 129 children aged 3-10 yrs demonstrated that 99% of children of 3 yrs and above can generate a flow > or = 30 L x min(-1) through the device, while 26% performed > or = 90 L x min(-1). Eighteen children aged 8-15 yrs with...... after salmeterol at either flow rates as compared to placebo. There was no significant difference in the protection from salmeterol on the day of low-flow inhalation versus the day of high-flow inhalation. Consistent in vitro fine particle dosing from the Diskus inhaler translates into a consistent...

  13. Flow

    DEFF Research Database (Denmark)

    2009-01-01

    Flow er en positiv, koncentreret tilstand, hvor al opmærksomhed er samlet om en bestemt aktivitet, som er så krævende og engagerende, at man må anvende mange mentale ressourcer for at klare den. Tidsfornemmelsen forsvinder, og man glemmer sig selv. 'Flow' er den første af en række udsendelser om...

  14. Regulation of peripheral blood flow in Complex Regional Pain Syndrome: clinical implication for symptomatic relief and pain management

    Directory of Open Access Journals (Sweden)

    Coderre Terence J

    2009-09-01

    Full Text Available Abstract Background During the chronic stage of Complex Regional Pain Syndrome (CRPS, impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS. Discussion The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin. Summary The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients.

  15. Clinical utility of far-infrared therapy for improvement of vascular access blood flow and pain control in hemodialysis patients

    OpenAIRE

    Choi, Soo Jeong; Cho, Eun Hee; Jo, Hye Min; Min, Changwook; Ji, Young Sok; Park, Moo Yong; Kim, Jin Kuk; Hwang, Seung Duk

    2015-01-01

    Background Maintenance of a well-functioning vascular access and minimal needling pain are important goals for achieving adequate dialysis and improving the quality of life in hemodialysis (HD) patients. Far-infrared (FIR) therapy may improve endothelial function and increase access blood flow (Qa) and patency in HD patients. The aim of this study was to evaluate effects of FIR therapy on Qa and patency, and needling pain in HD patients. Methods This prospective clinical trial enrolled 25 out...

  16. Informatics in radiology: improving clinical work flow through an AIM database: a sample web-based lesion tracking application.

    Science.gov (United States)

    Abajian, Aaron C; Levy, Mia; Rubin, Daniel L

    2012-01-01

    Quantitative assessments on images are crucial to clinical decision making, especially in cancer patients, in whom measurements of lesions are tracked over time. However, the potential value of quantitative approaches to imaging is impeded by the difficulty and time-intensive nature of compiling this information from prior studies and reporting corresponding information on current studies. The authors believe that the quantitative imaging work flow can be automated by making temporal data computationally accessible. In this article, they demonstrate the utility of the Annotation and Image Markup standard in a World Wide Web-based application that was developed to automatically summarize prior and current quantitative imaging measurements. The system calculates the Response Evaluation Criteria in Solid Tumors metric, along with several alternative indicators of cancer treatment response, by using the data stored in the annotation files. The application also allows the user to overlay the recorded metrics on the original images for visual inspection. Clinical evaluation of the system demonstrates its potential utility in accelerating the standard radiology work flow and in providing a means to evaluate alternative response metrics that are difficult to compute by hand. The system, which illustrates the utility of capturing quantitative information in a standard format and linking it to the image from which it was derived, could enhance quantitative imaging in clinical practice without adversely affecting the current work flow. PMID:22745220

  17. Flow

    DEFF Research Database (Denmark)

    Knoop, Hans Henrik

    2006-01-01

    FLOW. Orden i hovedet på den fede måde Oplevelsesmæssigt er flow-tilstanden kendetegnet ved at man er fuldstændig involveret, fokuseret og koncentreret; at man oplever stor indre klarhed ved at vide hvad der skal gøres, og i hvilket omfang det lykkes; at man ved at det er muligt at løse opgaven...

  18. Catheter-based flow measurements in hemodialysis fistulas - Bench testing and clinical performance

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Lönn, Lars; Schroeder, Torben V;

    2012-01-01

    for systematic bias. In the clinical study, two interventional radiologists conducted a total of 250 measurements in 14 patients with arteriovenous fistulas to determine clinical precision and enable testing for bias between measurers.Results: Accuracy was excellent for both catheters with a high...

  19. Quantification of cerebral blood flow and its clinical usefulness. Application of SPECT to psychiatry

    International Nuclear Information System (INIS)

    Brain perfusion SPECT using 99mTc-ethyl-cysteinate dimer (99mTc-ECD) was applied to psychiatric diseases with aid of statistical parametric mapping (SPM) for analysis of data. To evaluate influence of aging on brain perfusion, noninvasive measurements of cerebral blood flow using 99mTc-ECD were performed in 53 normal volunteers, aged 18 to 87 years old. Mean cerebral blood flow (mCBF) was 43.9±5.0 ml/100 g/min and showed weak negative correlation with aging (r=-0.451). Perisylvian cerebral cortices and medial frontal areas including anterior cingulate gyri showed greater negative correlation than other areas. These findings suggest the necessity of age-matched control regional CBF (rCBF) data to investigate rCBF abnormality in patients. Four drug-naive schizophrenic patients showed flow decrease in bilateral frontal and superior temporal areas and a left infero-posterior temporal area. Haloperidol administration induced flow decrease in bilateral frontal and left parietal areas, while flow increase in bilateral striatal and right hippocampal areas. Ten aged depressive patients showed flow decrease in bilateral frontal and left temporo-parietal areas. Even after remission patients showed flow decrease in the left frontal area as compared with normal subjects. Remission induced flow increase in the right frontal, right parietal, and right orbitofrontal areas compared with depression. These results suggest that CBF measurements using 99mTc-ECD are useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

  20. Quantification of cerebral blood flow and its clinical usefulness. Application of SPECT to psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi; Uema, Takeshi; Kogure, Daisuke; Takano, Harumasa; Terada, Tomo [National Center Hospital for Mental, Nervous and Muscular Disorders, Kodaira, Tokyo (Japan)

    1998-10-01

    Brain perfusion SPECT using {sup 99m}Tc-ethyl-cysteinate dimer ({sup 99m}Tc-ECD) was applied to psychiatric diseases with aid of statistical parametric mapping (SPM) for analysis of data. To evaluate influence of aging on brain perfusion, noninvasive measurements of cerebral blood flow using {sup 99m}Tc-ECD were performed in 53 normal volunteers, aged 18 to 87 years old. Mean cerebral blood flow (mCBF) was 43.9{+-}5.0 ml/100 g/min and showed weak negative correlation with aging (r=-0.451). Perisylvian cerebral cortices and medial frontal areas including anterior cingulate gyri showed greater negative correlation than other areas. These findings suggest the necessity of age-matched control regional CBF (rCBF) data to investigate rCBF abnormality in patients. Four drug-naive schizophrenic patients showed flow decrease in bilateral frontal and superior temporal areas and a left infero-posterior temporal area. Haloperidol administration induced flow decrease in bilateral frontal and left parietal areas, while flow increase in bilateral striatal and right hippocampal areas. Ten aged depressive patients showed flow decrease in bilateral frontal and left temporo-parietal areas. Even after remission patients showed flow decrease in the left frontal area as compared with normal subjects. Remission induced flow increase in the right frontal, right parietal, and right orbitofrontal areas compared with depression. These results suggest that CBF measurements using {sup 99m}Tc-ECD are useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

  1. Clinical and Experimental Study of Effects of Rhubarb on Gastrointestinal Blood Flow Perfusion in Critical Illness

    Institute of Scientific and Technical Information of China (English)

    CHEN; De-chang

    2001-01-01

    [1]Border JR. Multiple system organ failure. Ann Surg 1992;216(2)∶111-116.[2]Schiessel R, Feil W, Wenzel E. Mechanisms of stress ulceration and implications for treatment. Gastroenterol Clin North Am 1990;19(1)∶101-120.[3]CHEN DC, YANG JD, YANG XY, et al. The effects of rhubarb on permeability of intestinal mucosa and blood vessel in shocked rats. Chin Crit Care Med 1997;9(7)∶385-387.[4]CHEN DC, JING BW. The effects of rhubarb on the protection of gut barrier. Chin Crit Care Med 1994;6(6)∶329-331.[5]American College of Chest Physician/Society of Critical Care Medicine Consensus: Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Crit Care Med 1992;20(6)∶864-874.[6]CHEN DC, JING BW, YANG XY, et al. Therapeutic effects of rhubarb on gastrointestinal failure. Med J Chin PLA 1996;21(1)∶24-26.[7]Nakayama SE. Infusion of very hypertonic saline to bled rats: membrane potential and fluid shifts. J Surg Res 1985;38(2)∶180-186.[8]Bulkley GB. Relationship of blood flow and oxygen consumption to ischemic injury in the canine small intestine. Gastroenterology 1985;89(4)∶852-857.[9]Marshall JC, Christon NV, Meakins JL, et al. The gastrointestinal tract: The “undrained abscess” of multiple organ failure. Ann Surg 1993;218(2)∶111-119.[10].Fiddiann-Green RG, McGough E, Pittenger G, et al. Predictive value of intramural pH and other risk factors for massive bleeding from stress ulceration. Gastroenterology. 1983;85(3)∶613-620.[11].ZHU L, YANG ZC, LI A. Changes and significance of the ability of gastric acid excretion during burn shock in rats. Chin Crit Care Med 1997;9(7)∶398-399.[12].JIAO DH, CHEN SX, ZHANG GH, et al. Clinical study of the effects of rhubarb on peptic ulcer with hemorrhage. CJITWM 1984;10(10)∶597-599.[13].YU JD, GONG LS. Effects of rhubarb on thromboxane A2 and prostacyclin in circulation blood in healthy people and acute myocardial

  2. The Diagnostic Value of Flow Cytometry Imunophenotyping in an Albanian Patient Population with a Preliminary Clinical Diagnosis of Chronic Lymphocytic Leukemia

    Directory of Open Access Journals (Sweden)

    Valentina Semanaj

    2014-03-01

    Conclusion: Flow cytometry immunophenotyping is a fundamental examination for the final diagnosis of chronic lymphocytic leukemia. The expression of CD38+ in CLL patients stands for a more advanced clinical stage.

  3. Exhaled nitric oxide measure using multiple flows in clinically relevant subgroups of COPD

    DEFF Research Database (Denmark)

    Roberts, Nassim Bazeghi; Gerds, Thomas A; Budtz-Jørgensen, Esben;

    2011-01-01

    meaningful subgroups of COPD in a group of 91 COPD patients with FEV(1) 17-77% of predicted. Multiple flow rates FeNO at 10, 30, 50, 100 and 200 mL/s were measured and a two-compartment model was used to estimate the diffusion Capacity (D), alveolar NO concentration (Calv) and airway wall NO concentration...

  4. Synthesis of [18F]FMISO in a flow-through microfluidic reactor: Development and clinical application

    International Nuclear Information System (INIS)

    Introduction: The PET radiotracer [18F]FMISO has been used in the clinic to image hypoxia in tumors. The aim of the present study was to optimize the radiochemical parameters for the preparation of [18F]FMISO using a microfluidic reaction system. The main parameters evaluated were (1) precursor concentration, (2) reaction temperature, and (3) flow rate through the microfluidic reactor. Optimized conditions were then applied to the batch production of [18F]FMISO for clinical research use. Methods: For the determination of optimal reaction conditions within a flow-through microreactor synthesizer, 5–400 μL the precursor and dried [18F]fluoride solutions in acetonitrile were simultaneously pushed through the temperature-controlled reactor (60–180 °C) with defined flow rates (20–120 μL/min). Radiochemical incorporation yields to form the intermediate species were determined using radio-TLC. Hydrolysis to remove the protecting group was performed following standard vial chemistry to afford [18F]FMISO. Results: Optimum reaction parameters for the microfluidic set-up were determined as follows: 4 mg/mL of precursor, 170 °C, and 100 μL/min pump rate per reactant (200 μL/min reaction overall flow rate) to prepare the radiolabeled intermediate. The optimum hydrolysis condition was determined to be 2 N HCl for 5 min at 100 °C. Large-scale batch production using the optimized conditions gave the final, ready for human injection [18F]FMISO product in 28.4 ± 3.0% radiochemical yield, specific activity of 119 ± 26 GBq/μmol, and > 99% radiochemical and chemical purity at the end of synthesis (n = 4). Conclusion: By using the NanoTek microfluidic synthesis system, [18F]FMISO was successfully prepared with good specific activity and high radiochemical purity for human use. The product generated from large-scale batch production using flow chemistry is currently being used in clinical research

  5. Combined Craniocerebral Trauma. Report 1. Peculiarities of the Acute Period Clinical Flow

    Directory of Open Access Journals (Sweden)

    Fraerman A.P.

    2010-09-01

    Full Text Available A classification and peculiarities of the combined craniocerebral trauma acute period clinical manifestation depending on localization of the intracranial damages (a damage of a facial skeleton, a spinal cord, a chest, the abdominal cavity organs are presented in the first part of lecture. The organism general reactions at the different combinations of damages (a traumatic shock, hemorrhage, fat embolism are demonstrated.

  6. Doppler derived quantitative flow estimate in coronary artery bypass graft: a computational multiscale model for the evaluation of the current clinical procedure.

    Science.gov (United States)

    Ponzini, Raffaele; Lemma, Massimo; Morbiducci, Umberto; Montevecchi, Franco M; Redaelli, Alberto

    2008-09-01

    In order to investigate the reliability of the so called mean velocity/vessel area formula adopted in clinical practice for the estimation of the flow rate using an intravascular Doppler guide wire instrumentation, a multiscale computational model was used to give detailed predictions on flow profiles within Y-shaped coronary artery bypass graft (CABG) models. At this purpose three CABG models were built from clinical patient's data and used to evaluate and compare, in each model, the computed flow rate and the flow rate estimated according to the assumption of parabolic velocity profile. A consistent difference between the exact and the estimated value of the flow rate was found in every branch of all the graft models. In this study we showed that this discrepancy in the flow rate estimation is coherent to the theory of Womersley regarding spatial velocity profiles in unsteady flow conditions. In particular this work put in evidence that the error in flow rate estimation can be reduced by using the estimation formula recently proposed by Ponzini et al. [Ponzini R, Vergara C, Redaelli A, Veneziani A. Reliable CFD-based estimation of flow rate in haemodynamics measures. Ultrasound Med Biol 2006;32(10):1545-55], accounting for the unsteady nature of blood, applicable in the clinical practice without resorting to further measurements. PMID:17980641

  7. Subchorionic hematomas in early pregnancy: clinical outcome and blood flow patterns.

    Science.gov (United States)

    Kurjak, A; Schulman, H; Zudenigo, D; Kupesic, S; Kos, M; Goldenberg, M

    1996-01-01

    A case control study of 59 women with subchorionic hematomas compared to 135 normally pregnant. Transvaginal ultrasound was used to image the pregnancy, and identify the site and size of the hematomas. Color flow Doppler was used to calculate velocity indices of the spiral arteries. More spontaneous abortions occurred in women with subchorionic hematomas (SCH). There was general correlation between gestational age, velocity indices, and hematoma size. There were 10 spontaneous abortions in the study group (17%) versus 9 (6.5%) in the controls (P = 0.02). Hematoma size did not affect outcome, but site did. Most hematomas associated with abortion were found in the corpus or fundus of the uterus, not in the supracervical area (P = 0.03). The presence of a hematoma did not affect the frequency of preterm delivery. In conclusion, subchorionic hematomas in early pregnancy are associated with an increased risk of spontaneous abortion. Flow disturbances are seen in the spiral arteries, but these are probably secondary effects. The critical factor is site of hematoma, not volume. PMID:8796766

  8. A network flow approach for tactical resource planning in outpatient clinics.

    Science.gov (United States)

    Nguyen, Thu Ba T; Sivakumar, Appa Iyer; Graves, Stephen C

    2015-06-01

    This paper introduces a deterministic model to plan the physician requirements for outpatient clinics to achieve service targets for the appointment lead-times of patients. The Ministry of Health of Singapore has established targets for the median, 95th percentile, and 100th percentile of appointment lead-times for patients, since long appointment postponements are regarded as being unacceptable for health care services. The study is to match the capacity of the healthcare providers to the patient demand for a re-entry system, subject to restrictions on the appointment lead-times for patients. We propose a mixed-integer programming model for planning capacity with the minimization of the maximum required capacity as its objective. In the model we assume a finite planning horizon, deterministic arrivals, multiple types of patients, identical physicians, and dependent demand between types of patients. We solve this model with a Branch and Cut algorithm. We test the model with numerical experiments using real data from the chosen specialty at the outpatient clinic of the studied hospital. The results show the value of the proposed model via a systematic push-pull mechanism in scheduling patients' requests to minimize the objective. The clinic should use one of the appointment lead-time targets to determine the patients' appointment dates. Finally, from the sensitivity analyses we demonstrate that the objective is negatively correlated with first-visit patients' appointment lead-time targets, the discharge rates, and the re-visit patients' mean appointment lead-time; we find a positive correlation between the first-visit patients' mean appointment lead-time and the appointment lead-time targets. PMID:24879403

  9. Experimental study and preliminary clinical application of microwave coagulation therapy for hepatic malignancies after interruption of hepatic blood flow

    International Nuclear Information System (INIS)

    Objective: To investigate the change on the extent of coagulated lesion under various interrupting methods of hepatic blood flow in vivo animal livers, and the clinical effect of combining transcatheter arterial chemoembolization (TACE) with percutaneous microwave coagulation therapy (PMCT) for primary and metastatic hepatic tumors. Methods: Using FORSEA MTC-3-500s microwave coagulator, we performed microwave tissue coagulation in vivo liver of 6 pigs at 60 W, 2 min and of 20 rabbits at 40 W, 2 min with or without the interruption of hepatic blood flow. 27 patients with primary hepatic carcinoma (30 nodules) and 8 patients with metastatic carcinoma (12 nodules) underwent the combination therapy of 1-4 sessions of TACE followed by within 3-10 days by 1-3 sessions of PMCT guided by ultrasonography and/or CT. The 42 lesions measured from 2.3 cm to 15.6 cm were taken place. Results: In vivo liver, the greatest dimension of the lesions coagulated by microwave with the interruption of hepatic arterial and portal flow were 22.5 ± 0.6 mm at 40 W , 2 min and 28.6 ± 1.2 mm at 60 W, 2 min, which were markedly larger than those without the interruption (13.3±0.3; and 15.6 ± 0.7 mm, P<0.001). In 35 cases of hepatic tumor, necrotic areas showed no enhancement. Complete necroses were observed for 29 nodules, with 24 smaller than 5 cm. On dynamic enhanced computed tomography (CT) or magnetic resonance imaging (MRI) within 2 W after combination therapy, 31 lesions were significantly shrunk. No serious complication was observed. The follow-up was carried on from 3 to 23 months (mean 11 month), 31 survival patients showed improvement in livelihood. One died of cardiac infarction (within 3 months), 2 of digestive hemorrhage, and 1 of dysfunction of liver (within 3 and 6 months). Conclusion: The microwave tissue coagulation region can enlarge markedly after interruption of hepatic blood flow. Preliminary clinical application of combination therapy of TACE and PMCT provides safe and

  10. Cerebral blood flow changes with acute cocaine intoxication: clinical correlations with SPECT, CT, and MRI.

    Science.gov (United States)

    Mena, I; Giombetti, R J; Miller, B L; Garrett, K; Villanueva-Meyer, J; Mody, C; Goldberg, M A

    1994-01-01

    In summary, these data suggest that widespread primary or secondary cerebral vasoconstriction is common in patients with neurological complications from cocaine. In most patients, SPECT showed wide-spread hypoperfusion in regions that had no clear clinical significance (e.g., the periventricular area). In many, the SPECT was performed more than 24 hours after the onset of neurological symptomatology. These findings raise several questions. It has been assumed that these SPECT changes in patients with acute neurological symptoms are temporary, although it will be important to determine whether these areas of hypoperfusion persist after symptoms have abated. Recently, Holman and colleagues (1991) found multifocal and deep areas of hypoperfusion with SPECT in 16 of 18 patients with a history of chronic cocaine abuse. Although most of the subjects tested positive for cocaine, several had abstained from cocaine use for weeks prior to the study. All 18 subjects had neuropsychological deficits, 13 mild and 5 moderate. Similarly, Pascual-Leone and colleagues (1991) have shown that CT scan atrophy strongly correlates with the duration of cocaine abuse, suggesting that brain injury may occur with continued use of cocaine. It is the authors' concern that cocaine abuse might produce permanent changes in cerebral perfusion. In conclusion, brain SPECT was found to be a useful procedure in the evaluation of acute cocaine intoxication. Brain SPECT revealed focal cortical lesions not seen on head CT or MRI, which corresponded to clinical deficits. In addition, [99mTc]HMPAO brain SPECT had a characteristic scalloped appearance, and this may be a marker for acute intoxication with cocaine. This study further supports the contention that cocaine causes neurological disease by its vasoconstrictive action. PMID:7603541

  11. High-Flow Nasal Cannula Oxygen Therapy in Adults: Physiological Benefits, Indication, Clinical Benefits, and Adverse Effects.

    Science.gov (United States)

    Nishimura, Masaji

    2016-04-01

    High-flow nasal cannula (HFNC) oxygen therapy is carried out using an air/oxygen blender, active humidifier, single heated tube, and nasal cannula. Able to deliver adequately heated and humidified medical gas at flows up to 60 L/min, it is considered to have a number of physiological advantages compared with other standard oxygen therapies, including reduced anatomical dead space, PEEP, constant FIO2 , and good humidification. Although few large randomized clinical trials have been performed, HFNC has been gaining attention as an alternative respiratory support for critically ill patients. Published data are mostly available for neonates. For critically ill adults, however, evidence is uneven because the reports cover various subjects with diverse underlying conditions, such as hypoxemic respiratory failure, exacerbation of COPD, postextubation, preintubation oxygenation, sleep apnea, acute heart failure, and conditions entailing do-not-intubate orders. Even so, across the diversity, many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces the need for respiratory support escalation. Some important issues remain to be resolved, such as definitive indications for HFNC and criteria for timing the starting and stopping of HFNC and for escalating treatment. Despite these issues, HFNC has emerged as an innovative and effective modality for early treatment of adults with respiratory failure with diverse underlying diseases. PMID:27016353

  12. Preliminary clinical study of regional cerebral blood flow SPECT imaging in patients with hemi-spatial neglect

    International Nuclear Information System (INIS)

    Objective: To explore the relationships between the occurrence and severity of the neglect and the region, range or extent of the decrease of regional cerebral blood flow (rCBF), the authors performed rCBF SPECT imaging on 19 patients with hemi-spatial neglect. Methods: Nineteen dextro manual subjects who were diagnosed with unilateral stroke clinically and neglect by a neglect test battery underwent rCBF SPECT imaging. Results: On SPECT imaging, the patients with neglect had damages in the frontal cortex mostly, parietal secondly, and then in order of occipital, temporal cortex, basal ganglia and thalamus. The patients who had two or more regions damaged showed neglect more frequently. The most significant region was temporal-parietal-occipital junction. The correlation coefficients between rCBF and the decreased percentage of rCBF and the severity of neglect were -0.34 (t = -1.5, P > 0.05) and 0.34 (t = 1.47, P > 0.05). The correlation coefficients between the range, number of foci, the flow deficit size and the severity of neglect were 0.71 (t = 4.13, P < 0.01), 0.70 (t = 4.07, P < 0.01) and 0.64 (t = 3.40, P < 0.01), respectively. Conclusions: The severity of neglect correlates with rCBF and the decreased percentage of rCBF insignificantly, while it correlates positively with the range, number of foci and the flow deficit size significantly. The authors suggest that hemi-spatial neglect usually results from the damage of multiple sites, and the complex damage of multiple sites results in more severe neglect

  13. Measurement of mean cerebral blood flow using SPECT and dementia rating scales in the memory clinic

    International Nuclear Information System (INIS)

    We investigated the association between mean cerebral blood flow (mCBF) values using single photon emission computed tomography (SPECT) and cognitive performance scores of three dementia rating scales (ADAS, MMSE, HDS-R). Mean CBF was measured by the 123I-IMP-ARG method in a selected group of 51 out-patients aged 41 to 90 years and by the 99mTc-ECD method in the other group of 57 out-patients aged 51 to 91 years. Simple regressions were calculated for each of the neuropsychological clusters and mCBF values. In 123I-IMP-ARG-SPECT study, there was a significant correlation between the mCBF values and HDS-R scores (R=0.37, p=0.01). 99mTc-ECD-SPECT study revealed statistically significant correlations between the mCBF values and ADAS scores (R=-0.48, p123I-IMP-ARG-SPECT study and 99mTc-ECD-SPECT study showed the progressive declines of mCBF with advancing cognitive dysfunctions. Using the cut-off point study (23/24 scores in MMSE and 20/21 scores in HDS-R), we have found that the patients with cognitive dysfunctions had lower mCBF values than the patients with those in each group of aged 60-69 years, 70-79 years, and 80-89 years. However, the difference of mCBF values between the groups with cognitive dysfunctions and without those had decreased gradually with advancing age. The present study suggests that SPECT can provide important functional informations to assess the cognitive impairment in patients with the memory disturbance. (author)

  14. Sub-2 μm chromatography and fast flow injection analysis for high-throughput analysis of clinical samples

    International Nuclear Information System (INIS)

    Complete text of publication follows. In HPLC the size of commercially available particles has been recently extended to 1.8 and 1.5 μm leading to an immense improvement of both chromatographic and economic efficiency due to the higher chromatographic resolution and the possibility of shorter cycle times. The present work aimed at the development and assessment of a high-throughput HPLC method for accurate quantification of oxaliplatin in clinical samples. A sub-2 μm stationary phase has been evaluated for complementary speciation of oxaliplatin via HPLC-ICP-MS and HPLC-ESI-TOFMS. We have selected ICP-QMS and ESI-TOFMS as chromatographic detectors, since both mass spectrometers are providing satisfactory time constants and sampling rates for a combination with ultra-fast HPLC. The two instruments were compared evaluating their detection capabilities and influence on the chromatographic performance. The second part of the presentation deals with the implementation of fast flow injection set-up for rapid analysis of clinically relevant elements with ICP-SFMS. First results will be presented.

  15. Can cerebral blood flow measurement predict clinical outcome in the acute phase in patients with artherosclerotic occlusive carotid artery disease?

    International Nuclear Information System (INIS)

    It has been thought that the clinical course of patients with acute carotid occlusive disease depends on their collateral cerebral blood flow (CBF) and duration of ischemia. However, there have been few clinical reports to prove this hypothesis. Therefore, we performed CBF study in patients with artherosclerotic carotid occlusive disease in the very acute phase, and precisely assessed the prognosis of those patients under intensive medical therapy. This prospective study included a total of 44 patients (72±13 years) who were admitted to our hospital between April, 2007 and December, 2008. To evaluate their initial CBF, single photon emission computed tomography (SPECT) studies were performed within 6 hours after the onset. All patients included in this study were medically treated and were periodically followed up by neurological and radiological examination. Moreover, in patients with reduced CBF (ipsilateral CBF/contralateral CBF x 100: %CBF <80%), dobutamine-induce hyperdynamic therapy was performed. Multivariate analysis was performed to detect significant predictors for the occurrence of further cerebral infarction. Multivariate analysis showed that the occurrence of further infarction was associated with older age and smaller %CBF. Of 44 patients, 21 experienced further cerebral infarction within 10 days after onset. Fourteen out of 15 patients with %CBF <60% developed cerebral infarction. This study showed that the prognosis of the patients with artherosclerotic carotid occlusive disease in the acute phase is associated with their initial residual CBFs. It may be difficult to stop the developed cerebral infarction in those patients with %CBF <60% despite intensive medical therapy. (author)

  16. Correlated regions of cerebral blood flow with clinical parameters in Parkinson's disease. Comparison using 'Anatomy' and 'Talairach Daemon' software

    International Nuclear Information System (INIS)

    We assign the anatomical names of functional activation regions in the brain, based on the probabilistic cyto-architectonic atlas by Anatomy 1.7 from an analysis of correlations between regional cerebral blood flow (rCBF) and clinical parameters of the non-demented Parkinson's disease (PD) patients by statistical parametric mapping (SPM) 8. We evaluated Anatomy 1.7 of SPM toolbox compared to 'Talairach Daemon' (TD) Client 2.4.2 software. One hundred and thirty-six patients (mean age 60.0±9.09 years; 73 women and 63 men) with non-demented PD were selected. Tc-99m-HMPAO brain single-photon emission computed tomography (SPECT) scans were performed on the patients using a two-head gamma-camera. We analyzed the brain image of PD patients by SPM8 and found the anatomical names of correlated regions of rCBF perfusion with the clinical parameters using TD Client 2.4.2 and Anatomy 1.7. The SPM8 provided a correlation coefficient between clinical parameters and cerebral hypoperfusion by a simple regression method. To the clinical parameters were added age, duration of disease, education period, Hoehn and Yahr (H and Y) stage and Korean mini-mental state examination (K-MMSE) score. Age was correlated with cerebral perfusion in the Brodmann area (BA) 6 and BA 3b assigned by Anatomy 1.7 and BA 6 and pyramis in gray matter by TD Client 2.4.2 with p<0.001 uncorrected. Also, assigned significant correlated regions were found in the left and right lobules VI (Hem) with duration of disease, in left and right lobules VIIa crus I (Hem) with education, in left insula (Ig2), left and right lobules VI (Hem) with H and Y, and in BA 4a and 6 with K-MMSE score with p<0.05 uncorrected by Anatomy 1.7, respectively. Most areas of correlation were overlapped by two different anatomical labeling methods, but some correlation areas were found with different names. Age was the most significantly correlated clinical parameter with rCBF. TD Client found the exact anatomical name by the peak

  17. Quantification of myocardial blood flow with {sup 82}Rb positron emission tomography: clinical validation with {sup 15}O-water

    Energy Technology Data Exchange (ETDEWEB)

    Prior, John O.; Allenbach, Gilles; Bischof Delaloye, Angelika [Centre Hospitalier Universitaire Vaudois and University of Lausanne, Nuclear Medicine Department, Lausanne (Switzerland); Valenta, Ines; Burger, Cyrill [Cardiac Imaging, Department of Radiology, Zurich (Switzerland); Kosinski, Marek [Centre Hospitalier Universitaire Vaudois and University of Lausanne, Nuclear Medicine Department, Lausanne (Switzerland); Centre Hospitalier Universitaire Vaudois and University of Lausanne, University Institute for Radiation Physics, Lausanne (Switzerland); Verdun, Francis R. [Centre Hospitalier Universitaire Vaudois and University of Lausanne, University Institute for Radiation Physics, Lausanne (Switzerland); Kaufmann, Philipp A. [Cardiac Imaging, Department of Radiology, Zurich (Switzerland); University of Zurich, Zurich Centre for Integrative Human Physiology (ZIHP), Zurich (Switzerland)

    2012-06-15

    coronary artery territories (p > 0.31). Quantification of MBF with {sup 82}Rb with a newly derived correction for the nonlinear extraction function was validated against MBF measured using {sup 15}O-water in control subjects and patients with mild CAD, where it was found to be accurate at high flow rates. {sup 82}Rb-derived MBF estimates seem robust for clinical research, advancing a step further towards its implementation in clinical routine. (orig.)

  18. Usefulness of the automatic quantitative estimation tool for cerebral blood flow. Clinical assessment of the application software tool AQCEL

    International Nuclear Information System (INIS)

    AQCEL enables automatic reconstruction of single-photon emission computed tomogram (SPECT) without image degradation and quantitative analysis of cerebral blood flow (CBF) after the input of simple parameters. We ascertained the usefulness and quality of images obtained by the application software AQCEL in clinical practice. Twelve patients underwent brain perfusion SPECT using technetium-99m ethyl cysteinate dimer at rest and after acetazolamide (ACZ) loading. Images reconstructed using AQCEL were compared with those reconstructed using conventional filtered back projection (FBP) method for qualitative estimation. Two experienced nuclear medicine physicians interpreted the image quality using the following visual scores: 0, same; 1, slightly superior; 2, superior. For quantitative estimation, the mean CBF values of the normal hemisphere of the 12 patients using ACZ calculated by the AQCEL method were compared with those calculated by the conventional method. The CBF values of the 24 regions of the 3-dimensional stereotaxic region of interest template (3DSRT) calculated by the AQCEL method at rest and after ACZ loading were compared to those calculated by the conventional method. No significant qualitative difference was observed between the AQCEL and conventional FBP methods in the rest study. The average score by the AQCEL method was 0.25±0.45 and that by the conventional method was 0.17±0.39 (P=0.34). There was a significant qualitative difference between the AQCEL and conventional methods in the ACZ loading study. The average score for AQCEL was 0.83±0.58 and that for the conventional method was 0.08±0.29 (P=0.003). During quantitative estimation using ACZ, the mean CBF values of 12 patients calculated by the AQCEL method were 3-8% higher than those calculated by the conventional method. The square of the correlation coefficient between these methods was 0.995. While comparing the 24 3DSRT regions of 12 patients, the squares of the correlation coefficient

  19. Clinical significance of regional cerebral blood volume and flow-to-volume ratio in ischemic cerebrovascular disease measeured by SPECT

    International Nuclear Information System (INIS)

    Regional cerebral blood volume (rCBV) and flow-to-volume ratio (rCBF/rCBV) were evaluated for clinical significance in comparison to rCBF and findings in X-ray CT (XCT) and radionuclide (RNA) and contrast angiography (CAG). A total of 109 cases were studied within 90 days after cerebrovascular ischemic attack. CBV SPECT was performed following CBF SPECT with I-123-IMP and RNA with Tc-99m-RBC, and processed for subtraction of I-123 contamination fraction. CBF/CBV images was obtained as the count ratio of CBF to CBV image at the same slice-level. Parametric rCBV and rCBF/rCBV were estimated as the count ratio of the focus to the contralateral normal region of interest. Image findings were scored by visual judgement. Student's t-test was applied for statistical analysis with a significance level of p=0.01. The rCBV-ratio was inversely proportional to rCBF/rCBV-ratio, and was different between the two groups with high and low score on flip-flop perfusion in RNA and among three groups with different postictal neurological course. The ratio was the highest for the group of improved course. The rCBF/rCBV-ratio was possibly correlated to rCBF-ratio, and was different between the two groups with high and low score on low density area in XCT, early perfusion in RNA and arterial stenosis in CAG. In the group of improved course, the ratio was different between the second and the third postictal week's duraiton. These results, therefore, suggest that rCBV-ratio reflects collateral perfusion, and is valuable for assessing postictal prognosis in cerebrovascular disease, and that rCBF/rCBV-ratio may reflect regional oxygen extraction fraction, and is valuable for speculating cerebral perfusion reserve. (author)

  20. Clinical study of cerebral blood flow in bilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF) in 34 patients with bilateral chronic subdural hematoma was measured by 99mTc-HMPAO SPECT before operation. The regional CBF was measured in 26 regions of the 10 cortical regions, putamen, thalamus and cerebellar hemisphere on both sides. According to the thickness of subdural hematoma, the thicker hematoma side was measured and examined as the thick hematoma side, and the other side as the thin hematoma side. Thirty four cases with bilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms :13 cases with headache (headache group), 10 cases with hemiparesis (hemiparesis group), 5 cases with tetraparesis (tetraparesis group) and 6 cases with consciousness disturbance or dementia (consciousness disturbance group), and into two groups according to the degree of midline brain shift on MRI: 14 cases of non-shifted group and 20 cases of shifted group. The average CBF of 34 patients in each region indicated a regional CBF reduction in the frontal, parietal and occipital cortices on the thin hematoma side, and in the putamen on the thick hematoma side. In the headache group, the regional CBF reduction on the thin hematoma side was found in the frontal, parietal and occipital cortices compared with the corresponding regions on the thick hematoma side, and in thalamus on the thick hematoma side. In the hemiparesis and tetraparesis groups, there was no statistically significant CBF reduction between the thick and thin hematoma sides. In the consciousness disturbance group, the CBF reduction in whole brain was remarkably significant. By the degree of the midline brain shift, the CBF reductions between the thick and thin hematoma sides were observed. Namely, in the shifted group, the CBF reductions were noted in the frontal, parietal and occipital cortices in the thin hematoma side, and in the putamen in the thick hematoma side. We concluded that the CBF reduction of bilateral chronic subdural hematoma was

  1. Clinical significance of ovarian stromal blood flow in assessment of ovarian response in stimulated cycle for in vitro fertilization

    Directory of Open Access Journals (Sweden)

    Aashima Arora

    2015-10-01

    Conclusions: Ovarian blood flow predicts ovarian responsiveness and hence provides a non-invasive and cost effective prognostic factor of IVF outcome. [Int J Reprod Contracept Obstet Gynecol 2015; 4(5.000: 1380-1383

  2. Clinical significance of ovarian stromal blood flow in assessment of ovarian response in stimulated cycle for in vitro fertilization

    OpenAIRE

    Aashima Arora; Shalini Gainder; Lakhbir Dhaliwal; Vanita Suri

    2015-01-01

    Background: Several ultrasound parameters have been examined to predict the ovarian response to gonadotropins. The only parameter that has been conclusively proven to predict ovarian response is the antral follicle count. It has been suggested that ovarian blood flow may play a crucial role in the development of ovarian follicles. The present study was planned to prospectively analyse the effect of ovarian stromal blood flow on ovarian responsiveness in terms of number of oocytes retrieved in...

  3. Two-Dimensional Cutting (TDC Vitrectome: In Vitro Flow Assessment and Prospective Clinical Study Evaluating Core Vitrectomy Efficiency versus Standard Vitrectome

    Directory of Open Access Journals (Sweden)

    Mitrofanis Pavlidis

    2016-01-01

    Full Text Available Purpose. To evaluate comparative aspiration flow performance and also vitrectomy operating time efficiency using a double-cutting open port vitreous cutting system incorporated in a two-dimensional cutting (TDC, DORC International vitrectome design versus standard vitreous cutter. Methods. In vitro investigations compared aspiration flow rates in artificial vitreous humor at varying cutter speeds and vacuum levels using a TDC vitrectome and a standard vitrectome across different aspiration pump systems. A prospective single-centre clinical study evaluated duration of core vitrectomy in 80 patients with macular pucker undergoing 25-gauge or 27-gauge vitrectomy using either a TDC vitrectome at 16,000 cuts per minute (cpm or standard single-cut vitrectome, combined with a Valve Timing intelligence (VTi pump system (EVA, DORC International. Results. Aspiration flow rates remained constant independent of TDC vitrectome cut rate, while flow rates decreased linearly at higher cutter speeds using a classic single-blade vitrectome. Mean duration of core vitrectomy surgeries using a TDC vitreous cutter system was significantly (p<0.001 shorter than the mean duration of core vitrectomy procedures using a single-cut vitrectome of the same diameter (reduction range, 34%–50%. Conclusion. Vitrectomy surgery performed using a TDC vitrectome was faster than core vitrectomy utilizing a standard single-action vitrectome at similar cut speeds.

  4. Two-Dimensional Cutting (TDC) Vitrectome: In Vitro Flow Assessment and Prospective Clinical Study Evaluating Core Vitrectomy Efficiency versus Standard Vitrectome.

    Science.gov (United States)

    Pavlidis, Mitrofanis

    2016-01-01

    Purpose. To evaluate comparative aspiration flow performance and also vitrectomy operating time efficiency using a double-cutting open port vitreous cutting system incorporated in a two-dimensional cutting (TDC, DORC International) vitrectome design versus standard vitreous cutter. Methods. In vitro investigations compared aspiration flow rates in artificial vitreous humor at varying cutter speeds and vacuum levels using a TDC vitrectome and a standard vitrectome across different aspiration pump systems. A prospective single-centre clinical study evaluated duration of core vitrectomy in 80 patients with macular pucker undergoing 25-gauge or 27-gauge vitrectomy using either a TDC vitrectome at 16,000 cuts per minute (cpm) or standard single-cut vitrectome, combined with a Valve Timing intelligence (VTi) pump system (EVA, DORC International). Results. Aspiration flow rates remained constant independent of TDC vitrectome cut rate, while flow rates decreased linearly at higher cutter speeds using a classic single-blade vitrectome. Mean duration of core vitrectomy surgeries using a TDC vitreous cutter system was significantly (p vitrectomy procedures using a single-cut vitrectome of the same diameter (reduction range, 34%-50%). Conclusion. Vitrectomy surgery performed using a TDC vitrectome was faster than core vitrectomy utilizing a standard single-action vitrectome at similar cut speeds. PMID:27190635

  5. Stereologic, histopathologic, flow cytometric, and clinical parameters in the prognostic evaluation of 74 patients with intraoral squamous cell carcinomas

    DEFF Research Database (Denmark)

    Bundgaard, T; Sørensen, Flemming Brandt; Gaihede, M;

    1992-01-01

    BACKGROUND AND METHODS: A consecutive series of all 78 incident cases of intraoral squamous cell carcinoma occurring during a 2-year period in a population of 1.4 million inhabitants were evaluated by histologic score (the modified classification of Jacobsson et al.), flow cytometry, stereology, ...

  6. Comparison of the myocardial blood flow response to regadenoson and dipyridamole: a quantitative analysis in patients referred for clinical {sup 82}Rb myocardial perfusion PET

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Behnaz; Fukushima, Kenji; Bravo, Paco; Merrill, Jennifer [Johns Hopkins University, Division of Nuclear Medicine, Russell H Morgan Department of Radiology, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H Morgan Department of Radiology, Baltimore, MD (United States); Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany)

    2011-10-15

    Regadenoson is a novel selective A{sub 2A} adenosine receptor agonist, which is administered as an intravenous bolus at a fixed dose. It is currently not clear if the absolute flow increase in response to this fixed dose is a function of distribution volume in individual patients or if it is generally comparable to the previous standard agents dipyridamole or adenosine, which are dosed based on weight. We used quantitative analysis of clinical {sup 82}Rb PET/CT studies to obtain further insights. A total of 104 subjects with normal clinical rest/stress {sup 82}Rb perfusion PET/CT were included in a retrospective analysis. To rule out confounding factors, none had evidence of prior cardiac disease, ischaemia or infarction, cardiomyopathy, diabetes with insulin use, calcium score >400, renal disease or other significant systemic disease. A group of 52 patients stressed with regadenoson were compared with a group of 52 patients stressed with dipyridamole before regadenoson became available. The groups were matched for clinical characteristics, risk factors and baseline haemodynamics. Myocardial blood flow (MBF) and myocardial flow reserve (MFR) were quantified using a previously validated retention model, after resampling of dynamic studies from list-mode {sup 82}Rb datasets. At rest, heart rate, blood pressure and MBF were comparable between the groups. Regadenoson resulted in a significantly higher heart rate (34 {+-} 14 vs. 23 {+-} 10 beats per minute increase from baseline; p < 0.01) and rate-pressure product. Patients in the regadenoson group reported less severe symptoms and required less aminophylline. Stress MBF and MFR were not different between the groups (2.2 {+-} 0.6 vs. 2.1 {+-} 0.6 ml/min/g, p = 0.39, and 2.9 {+-} 0.8 vs. 2.8 {+-} 0.7, p = 0.31, respectively). In the regadenoson group, there was no correlation between stress flow or MFR and body weight or BMI. Despite its administration at a fixed dose, regadenoson results in an absolute increase in MBF

  7. Evaluation of quatitative scintigraphic method in diagnosis of esophagic involvement of Progressive Systemic Sclerosis

    International Nuclear Information System (INIS)

    Twenty patients with Progressive Systemic Sclerosis are studied by scintigraphic methodology. The esophageal transit method is used for liquid and solid meals. The results are compared with the ones of a control group, without or not gastrintestinal problems but without autoimmune diasese. 99 sup(m)Tc-sulfurcolloid is used as labelling compound. The studies were done in supine and orthostatical position. (M.A.C.)

  8. S.E. Mitchell Vascular Anomalies Flow Chart (SEMVAFC): A visual pathway combining clinical and imaging findings for classification of soft-tissue vascular anomalies

    International Nuclear Information System (INIS)

    Classification of vascular anomalies (VAs) is challenging due to overlapping clinical symptoms, confusing terminology in the literature and unfamiliarity with this complex entity. It is important to recognize that VAs include two distinct entities, vascular tumours (VTs) and vascular malformations (VaMs). In this article, we describe SE Mitchell Vascular Anomalies Flow Chart (SEMVAFC), which arises from a multidisciplinary approach that incorporates clinical symptoms, physical examination and magnetic resonance imaging (MRI) findings to establish International Society for the Study of Vascular Anomalies (ISSVA)-based classification of the VAs. SEMVAFC provides a clear visual pathway for physicians to accurately diagnose Vas, which is important as treatment, management, and prognosis differ between VTs and VaMs

  9. Observing the coupled behavior of geochemistry and flow path evolution during bioreduction using clinical nuclear imaging tomography

    Science.gov (United States)

    Druhan, J. L.; Vandehey, N. T.; Buchko, R.; O'Neil, J. P.; Moses, W. W.; Finsterle, S.; Steefel, C.; Nico, P. S.

    2011-12-01

    We present results from the first meso-scale column study of flow and bioreductive reactive transport in a porous media using Single-Photon Emission Computed Tomography (SPECT) to obtain time-resolved flow field structure. SPECT allows us to detect the 3D distribution of a radioactive tracer and how it evolves through time as flow proceeds through a packed sediment column. The column size for the experiment is 10 cm diameter by 30 cm length, and the approximate spatial resolution is 4.4 mm (86 mm3 by volume). Our experiments involve a biologically mediated reduction reaction that partially immobilizes a conservative 99mTc-DTPA tracer. The procedure results in a 3D tomographic movie of the tracer distribution and concentration during the course of the flow-through experiment. The derived data represent an unprecedentedly detailed representation of reactive flow and transport that can be modeled to deconvolve the effects of permeability and reaction rate heterogeneity in controlling the transport of the tracer. The column was packed with sediment recovered from the Rifle IFRC site in western Colorado and all physical and chemical parameters were matched to field values. The artificial groundwater influent was supplemented with 10 mM acetate for 42 consecutive days, resulting in a characteristic trend of Fe reduction followed by SO4 reduction observed during uranium bioremediation at the Rifle field site. By day 42 SO4 concentration dropped across the column from an influent value of 8.8 mM to 4 mM at the effluent, while Ca concentrations dropped from 4.8 to 3.4 mM, suggesting substantial FeS and CaCO3 precipitation. Following day 42, acetate was removed from the influent solution and a rapid return to pre-acetate conditions was observed. During the course of the experiment 9 SPECT imaging studies were conducted for the through-flowing column using 99mTc-DTPA as a conservative tracer. Images were acquired on days -11, 3, 8, 15, 23, 30, 43, 77 and 91 relative to the

  10. Direct observations of flow path evolution during reactive transport in porous media using clinical nuclear imaging tomography

    Science.gov (United States)

    Druhan, J. L.; Finsterle, S.; Vandehey, N. T.; Boutchko, R.; O'Neil, J.; Moses, W. W.; Nico, P. S.

    2012-12-01

    Changes in the physical structure of a porous medium associated with heterogeneous reactivity are extremely difficult to observe directly. We require the ability to monitor, quantify and predict these changes in order to optimize contaminant sequestration and remediation strategies, develop carbon storage methods and preserve groundwater resources. Field-scale detection of chemically induced permeability alteration is often accomplished by multiple hydrogeophysical observations and pumping tests, whereas direct analysis of the structural changes in a porous medium are limited to small sample sizes that do not capture the range of length scales describing heterogeneity. Here we present a novel application of medical imaging techniques to directly observe variations in flow field structure associated with mineral precipitation in real time. We use a Single Photon Emission Computed Tomography (SPECT) scanner to observe the movement of a conservative 99mTc-DTPA tracer introduced to a through-flowing column of packed sediment recovered from the Old Rifle aquifer in Western Colorado. Nine individual imaging studies were carried out over the course of 112 days of continuous flow in the 30 cm long, 10 cm diameter column. During this time, organic carbon was supplied to the influent, leading to microbially mediated reduction of Fe(III) (hyrdo)oxides and sulfate. Permeability reduction associated with this reactivity is known to occur as a result of biomass accumulation and precipitation of FeS and carbonate minerals. The nine imaging datasets each yielded intensity values over a 24 hour period at a resolution of 4.42 mm3. These images were corrected for decay and attenuation to produce 4D datasets directly proportional to Tc-DTPA concentration. These data provide a highly accurate observation of the flow field during each imaging study, and are used to assign property values to the elements of a geostatistical model using the iTOUGH2 code. Permeability distributions

  11. Clinical Effectiveness of Centrifugal Pump to Produce Pulsatile Flow During Cardiopulmonary Bypass in Patients Undergoing Cardiac Surgery

    NARCIS (Netherlands)

    Gu, Y. John; van Oeveren, Willem; Mungroop, Hubert E.; Epema, Anne H.; den Hamer, Inez J.; Keizer, Jorrit J.; Leuvenink, Ron P.; Mariani, Massimo A.; Rakhorst, Gerhard

    2011-01-01

    Although the centrifugal pump has been widely used as a nonpulsatile pump for cardiopulmonary bypass (CPB), little is known about its performance as a pulsatile pump for CPB, especially on its efficacy in producing hemodynamic energy and its clinical effectiveness. We performed a study to evaluate w

  12. Use of Caval Subtraction 2D Phase-Contrast MR Imaging to Measure Total Liver and Hepatic Arterial Blood Flow: Preclinical Validation and Initial Clinical Translation.

    Science.gov (United States)

    Chouhan, Manil D; Mookerjee, Rajeshwar P; Bainbridge, Alan; Walker-Samuel, Simon; Davies, Nathan; Halligan, Steve; Lythgoe, Mark F; Taylor, Stuart A

    2016-09-01

    Purpose To validate caval subtraction two-dimensional (2D) phase-contrast magnetic resonance (MR) imaging measurements of total liver blood flow (TLBF) and hepatic arterial fraction in an animal model and evaluate consistency and reproducibility in humans. Materials and Methods Approval from the institutional ethical committee for animal care and research ethics was obtained. Fifteen Sprague-Dawley rats underwent 2D phase-contrast MR imaging of the portal vein (PV) and infrahepatic and suprahepatic inferior vena cava (IVC). TLBF and hepatic arterial flow were estimated by subtracting infrahepatic from suprahepatic IVC flow and PV flow from estimated TLBF, respectively. Direct PV transit-time ultrasonography (US) and fluorescent microsphere measurements of hepatic arterial fraction were the standards of reference. Thereafter, consistency of caval subtraction phase-contrast MR imaging-derived TLBF and hepatic arterial flow was assessed in 13 volunteers (mean age, 28.3 years ± 1.4) against directly measured phase-contrast MR imaging PV and proper hepatic arterial inflow; reproducibility was measured after 7 days. Bland-Altman analysis of agreement and coefficient of variation comparisons were undertaken. Results There was good agreement between PV flow measured with phase-contrast MR imaging and that measured with transit-time US (mean difference, -3.5 mL/min/100 g; 95% limits of agreement [LOA], ±61.3 mL/min/100 g). Hepatic arterial fraction obtained with caval subtraction agreed well with those with fluorescent microspheres (mean difference, 4.2%; 95% LOA, ±20.5%). Good consistency was demonstrated between TLBF in humans measured with caval subtraction and direct inflow phase-contrast MR imaging (mean difference, -1.3 mL/min/100 g; 95% LOA, ±23.1 mL/min/100 g). TLBF reproducibility at 7 days was similar between the two methods (95% LOA, ±31.6 mL/min/100 g vs ±29.6 mL/min/100 g). Conclusion Caval subtraction phase-contrast MR imaging is a simple and clinically

  13. Effects of long-term administration of Cilostazol on chronic cerebral circulatory insufficiency. With special reference to cerebral blood flow and clinical symptoms

    International Nuclear Information System (INIS)

    This report deals with a study of the effectiveness, safety, and usefulness of long-term administration of Cilostazol for the improvement of cerebral blood flow and clinical symptoms in 24 patients with Chronic Cerebral Circulatory Insufficiency. Cerebral blood flow was investigated quantitatively using the Patlak plot method. Cilostazol was orally administered for 209 days on average. In the global improvement rating assessed on the basis of all subjective symptoms, the final improvement rate, comprising all cases showing moderate or better improvement, was 52.2%. Regarding individual symptoms, dizziness, orthostatic syncope, dull headache, and headache showed improvement rates of 30% or more. Regional cerebral blood flow (rCBF) was increased in both cerebral and cerebellar hemispheres. The global improvement rating for subjective symptoms and the Δ%rCBF for every region except the cerebral hemispheres were positively correlated. However, there was no positive correlation between the global improvement rating for psychiatric symptoms and the Δ%rCBF for any region. Regarding individual subjective symptoms, dizziness showed an especially high positive correlation of above 0.7 between the improvement rating and the Δ%rCBF in the left temporal lobe, basal ganglia, and cerebellum. Headache was observed as an adverse drug reaction in 8 of 24 patients, but it disappeared with reduction of the dose or discontinuation of administration. No other severe adverse drug reactions were noticed. In summary, it was concluded that Cilostazol was useful for treating chronic cerebral circulatory insufficiency. (author)

  14. A simplified method of xenon-enhanced CT for regional cerebral blood flow (rCBF) measurement with reference to clinical experiences

    International Nuclear Information System (INIS)

    We introduced a simplified method of xenon-enhanced CT (SXe-CT) for obtaining the topographic regional cerebral blood flow (rCBF) map. In the SXe-CT, we used the method of brief (three to four minutes) inhalation of 40 % xenon. To shorten the period of xenon inhalation, we substituted a predetermined brain-blood partition coefficient (L) in the entire brain for the directly estimated L to calculate the rCBF value. Because of its non-invasiveness and simplicity, the SXe-CT can be applied to the patients with diseases in the central nervous system (CNS) without any difficulties. During the past three years, we performed the SXe-CT on 150 occasions in 100 subjects, including those with moyamoya disease, other ischemic cerebrovascular diseases, arteriovenous malformations and normal pressure hydrocephalus. In this paper, the rCBF values of seven normal healthy adults with a mean age of 24 years are reported and the flow maps of some cases of CNS diseases are presented. The normal mean value of the hemispheres was 53, those of the gray matter were in the range of 38 to 72, those of the white matter were in the range of 26 to 35 and those of the basal ganglia and thalamus were 55 to 88 (values are given in ml/100 g/min). The SXe-CT has potential advantages in obtaining clinically useful rCBF measurements. (author)

  15. Evaluation of lumbar sympathectomy impact on the clinical course, blood flow parameters and muscle perfusion in a group of patients with peripheral arterial disease (PAD)

    International Nuclear Information System (INIS)

    Background: Occlusive arterial disease is a common disease. Frequently, at the time of diagnosis, disease severity prevents revascularization. The study evaluated lumbar sympathectomy influence on the clinical course, blood flow parameters and muscle perfusion. Material/Methods: Research group included 33 patients (13 women - 39.4 %, and 20 men - 60.6 %) aged from 47 to 81 (mean age 63.54 ± 8.63 years) treated for PAD and qualified to undergo lumbar sympathectomy. Physical examination, standard vascular tests (ankle-brachial, thigh-ankle and thigh-shin indices, maximum flow velocity, PI and RI in selected arteries), perfusion scintigraphy of lower limbs muscles at rest and on exertion were carried out before and 6 months after surgery. Results: Statistically significant increase of total walking distance (71.82 meters vs. 177.58 meters, p < 0.002) was detected. On the basis of participants feelings, the effect of treatment as a positive was declared by 30 of them, representing 90.9 % of the sample. Only 2 patients (6.1 %) identified treatment as not affecting their health condition, and 1 patient (3.0 %) reported worsening of symptoms after treatment. Standard vascular tests and perfusion scintigraphy did not reveal any significant changes. Conclusions: Lumbar sympathectomy in patients suffering from severe, atherosclerotic lower limb ischaemia brought positive effects such as increasing walking distance, decreasing rest pain or healing skin ulcers. This effect was not combined with improvement of muscle blood (ulcer healing). (authors)

  16. Flow cytometric enumeration of CD34+ hematopoietic stem and progenitor cells in leukapheresis product and bone marrow for clinical transplantation: a comparison of three methods.

    Directory of Open Access Journals (Sweden)

    E Kraszewska

    2006-04-01

    Full Text Available Flow cytometric enumeration of CD34+ hematopoietic stem and progenitor cells (HSCs is widely used for evaluation of graft adequacy of peripheral blood and bone marrow stem cell grafts. In the present study, we review and compare the major counting techniques of stem and progenitor cells. The methods are: the Milan/Mullhouse protocol, two-platform ISHAGE (International Society of Hematotherapy and Graft Engineering and single-platform ISHAGE analysis system. According to the Milan/Mulhouse protocol, HSCs are identified by CD34 antibody staining and easy gating strategy. The ISHAGE guidelines for detection of CD34+ cells are based on a four-parameter flow cytometry method (CD34PE/CD45PerCP staining, side and forward angle light scatter thus employing multiparameter gating strategy. With two-platform ISHAGE protocol, an absolute CD34+ count is generated by incorporating the leukocyte count from an automated hematology analyser. The single-platform ISHAGE method to determine the absolute CD34+ count directly from a flow cytometer includes the use of Trucount tubes (Becton Dickinson with a known number of fluorescent beads. CD34+ cells were quantified in mobilized peripheral blood, collected by leukapheresis, and bone marrow from 42 samples from patients with hematological malignancies. The differences against the means display low disagreement between the Milan/Mulhouse and ISHAGE protocols, with discrepancies of up to 2.5% (two-platform ISHAGE--2.6% (single-platform ISHAGE in enumeration of CD34+ cells in leukapheresis product and 4.8% (two-platform ISHAGE--4.9% (single-platform ISHAGE in bone marrow. Our results show high correlation among all three methods. Since the three protocols are compatible, choosing the most convenient in terms of costs, simplicity and compliance with clinical results appears to be a logical consequence.

  17. Cerebral blood flow measurement in patients with impaired consciousness: usefulness of 99mTc-HMPAO single-photon emission tomography in clinical practice

    International Nuclear Information System (INIS)

    The relationship between impairment of consciousness and quantitative cerebral blood flow (CBF) was investigated. The mean CBF of the whole brain was measured by the Patlak-plot method using technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (99mTc-HMPAO SPET) in patients with the following diseases: cerebral infarction, intraparenchymal haemorrhage, subarachnoid haemorrhage, brain tumour and cerebral contusion. The clinical symptoms were evaluated according to the severity of impaired consciousness, aphasia and dementia. Four hundred and eighty-five CBF measurements were performed. Patients with alert consciousness showed an age-related decline in mean CBF. Patients with aphasia showed a significant reduction in mean CBF compared with those without aphasia. Impaired consciousness was proportional to reduction in mean CBF regardless of types of pathology, and the size of lesion did not influence the mean CBF. Patients with dementia showed a significant reduction in mean CBF proportional to the severity of dementia. The quantitative measurement of CBF using 99mTc-HMPAO SPET is reliable in clinical evaluations. (orig.)

  18. A novel lateral flow assay based on GoldMag nanoparticles and its clinical applications for genotyping of MTHFR C677T polymorphisms

    Science.gov (United States)

    Hui, Wenli; Zhang, Sinong; Zhang, Chao; Wan, Yinsheng; Zhu, Juanli; Zhao, Gang; Wu, Songdi; Xi, Dujuan; Zhang, Qinlu; Li, Ningning; Cui, Yali

    2016-02-01

    Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes.

  19. Study Of Topical Anti-Inflammatory Potency And Clinical Efficacy Of Formulations Of Mometasone And Betamethasone By Cutaneous Blood Flow Measurements In Psoriatic Patients Using Laser Doppler Velocimetry

    Directory of Open Access Journals (Sweden)

    Mulekar S. V

    1997-01-01

    Full Text Available Laser Doppier Velocimetry (LDV was used to measure cutaneous blood flow (CBF in psoriatic skin lesions to assess the effect of once daily application of Mometasone furoate (MF in a base claimed to possess a “reservoir” effect, as against Betamethasone-17-valarate (BV in a conventional cream base, applied twice daily, for 4 weeks. Bilaterally symmetrical active lesions were studied in 10 psoriatics, at baseline and at the end of 2 and 4 weeks’ treatment. The formulations were also evaluated for topical anti-inflammatory potency in terms of their ability to inhibit the Post-Ischaemic-Reactive-Hyperaemic-Response (PIRHR induced on normal uninvolved skin treated under occlusion. The lesions were also assessed subjectively for clinical Psoriatic Hyperaemia Index (PHI = CBF on lesions/CBF on uninvolved skin: 8.42 + 1.74 & 10.13 + 1.70 correlating with high CPI (9 + 0.50 & 9.1 + 0.51. During treatment with MF or BV, the lesions resolved rapidly, with a concomitant decrease in PHI and CPI (Week 2 : PHI = 3.40 + 0.46 & 5.19 + 1.65, CPI = 4.15 + 0.86& 5.20 + 0.87 and Week 4 : PHI = 1.99 + 0.23 & 2.81 + 0.74 CPI = 2.00 + 0.50 & 2.88 + 0.72 respectively. The two formulations Inhibited PIRHR to same extent (auc/min: Control = 1871 + 399.22, MF = 536.11 + 153.34 & BV = 567.5 + 110.76, indicating equal potency. The results show that pharmaceutical factor such as vehicle can significantly influence the clinical efficacy of corticoids.

  20. Regional cerebral blood flow and its correlation with clinical assessment in senile dementia of Alzheimer type and multi-infarct dementia

    International Nuclear Information System (INIS)

    Twenty-one patients with senile dementia of Alzheimer type (SDAT), 11 patients with multi-infarct dementia (MID), and 6 healthy volunteers were examined by SPECT using Xe-inhalation method. These patients also underwent an intelligence test according to the Gottfries-Brane-Steen (GBS) scale. Patients with mild SDAT did not have a significantly decreased regional cerebral blood flow (rCBF). In moderate or severe cases, however, a significantly decreased rCBF was bilaterally observed in all regions, except for the basal ganglia. This was marked in the temporoparietal region. A group of moderate or severe MID patients had a significantly decreased rCBF especially in the basal ganglia. It was also observed in the temporoparietal region, but not in the frontal region. Among the SDAT patients, there was a good correlation between rCBF and GBS scale in all the regions, except for the basal ganglia. In the case of MID patients, correlations were observed both between rCBF in the left side of the brain and clinical findings according to the method of Hasegawa and between rCBF in the right side of the frontal region and the motor function on the GBS scale. These findings may have implications for the different pathophysiology between SDAT and MID. (N.K.)

  1. CLINICAL ANALYSIS AND OPTIMIZATION OF POST-REMISSION THERAPY FOR ACUTE MYELOID LEUKEMIA PATIENTS WITH MINIMAL RESIDUAL DISEASE AS DETERMINED BY FLOW CYTOMETRY

    Directory of Open Access Journals (Sweden)

    Hayato Maruoka

    2010-05-01

    Full Text Available

    Background: Although several prognostic indicators of de novo acute myeloid leukemia (AML patients have been identified, the clinical significance of minimal residual disease (MRD needs to be evaluated further in Japanese adult patients.

    Methods: Using three color flow cytometry, we identified leukemia-associated phenotypes (LAP in bone marrow specimens at diagnosis and assessed the relationship between clinical outcomes and the presence of marrow MRD in 33 patients who achieved a morphologic complete remission (CR and were followed after CR.

    Results: Of 33 consecutive patients, we detected MRD in 20 patients after achieving CR (Group A and did not in 13 patients (Group B, with 2-year overall survival (OS rates of 49.0% and 84.6%, respectively (P =.0317, and relapse-free survival (RFS rates of 13.7% and 91.7%, respectively (P=.0010. By multivariate analysis, MRD-positivity at post-induction was found to be associated with a shorter duration of RFS (P=.0042. Notably, we achieved MRD negativity in

  2. Flow: Statistics, visualization and informatics for flow cytometry

    Directory of Open Access Journals (Sweden)

    Kepler Thomas B

    2008-06-01

    Full Text Available Abstract Flow is an open source software application for clinical and experimental researchers to perform exploratory data analysis, clustering and annotation of flow cytometric data. Flow is an extensible system that offers the ease of use commonly found in commercial flow cytometry software packages and the statistical power of academic packages like the R BioConductor project.

  3. Flow: Statistics, visualization and informatics for flow cytometry

    OpenAIRE

    Kepler Thomas B; Frelinger Jacob; Chan Cliburn

    2008-01-01

    Abstract Flow is an open source software application for clinical and experimental researchers to perform exploratory data analysis, clustering and annotation of flow cytometric data. Flow is an extensible system that offers the ease of use commonly found in commercial flow cytometry software packages and the statistical power of academic packages like the R BioConductor project.

  4. Two-Dimensional Cutting (TDC) Vitrectome: In Vitro Flow Assessment and Prospective Clinical Study Evaluating Core Vitrectomy Efficiency versus Standard Vitrectome

    OpenAIRE

    Mitrofanis Pavlidis

    2016-01-01

    Purpose. To evaluate comparative aspiration flow performance and also vitrectomy operating time efficiency using a double-cutting open port vitreous cutting system incorporated in a two-dimensional cutting (TDC, DORC International) vitrectome design versus standard vitreous cutter. Methods. In vitro investigations compared aspiration flow rates in artificial vitreous humor at varying cutter speeds and vacuum levels using a TDC vitrectome and a standard vitrectome across different aspiration p...

  5. COMPARISON OF FLOW AND VOLUME ORIENTED INCENTIVE SPIROMETRY ON LUNG FUNCTION AND DIAPHRAGM MOVEMENT AFTER LAPAROSCOPIC ABDOMINAL SURGERY: A RANDOMIZED CLINICAL PILOT TRIAL

    OpenAIRE

    Gopala Krishna Alaparthi; Alfred Joseph Augustine *; Anand R; Ajith Mahale

    2013-01-01

    Objective:This study was designed to evaluate the efficacy of two types of incentive spirometer (flow andvolume) on pulmonary function and diaphragm excursion in patients who underwent laparoscopic surgery.Materials and Methods:Twenty sample sizes with eleven men and nine women who underwent laparoscopicsurgery were randomly divided as follows: 10 subjects performed flow oriented incentive spirometer group,and other 10 subjects performed volume oriented incentive spirometer group. (Other ther...

  6. An evaluation of the regional cerebral blood flow (rCBF) measurement by xenon-enhanced dynamic CT with helical scanning technique and the functional imaging by multiplanar reconstruction (MPR). Fundamental study and clinical application

    International Nuclear Information System (INIS)

    We evaluated the quantitative rCBF by xenon-enhanced dynamic CT with helical scanning technique on all brain regions, and also examined clinical usefulness of coronal and sagittal section images which are similar to SPECT images obtained by the functional multiplanar reconstitution (MPR) imaging of many successive flow maps. We used 14 clinical cases. The conventional xenon-enhanced CT was simple and ideal method to measure rCBF, however, it had disadvantages; it gives a few laminagraphical images or only the axial directional images, compared to SPECT or PET. There is a risk to overlook lesions out of the image or not to obtain the whole images of the lesion. Although the helical scanning technique has a methodological characteristics to use adjacent data for the image reconstitution, it is by no means inferior to the conventional method in the contrast resolution or the image resolution when the co-helical function and an appropriate reconstituted function were used. It has an advantage to scan all brain regions by only one cycle of scanning. Furthermore on making good use of the property that the helical scanning technique can give the successive data, we can observe rCBF by coronal and sagittal images when many flow maps were made up by reconstituted images of the narrow steps. This shows the clinical usefulness of this technique. One of the future problem to be solved is to decrease the exposure dose. (K.H.)

  7. Flow Rounding

    OpenAIRE

    Kang, Donggu; Payor, James

    2015-01-01

    We consider flow rounding: finding an integral flow from a fractional flow. Costed flow rounding asks that we find an integral flow with no worse cost. Randomized flow rounding requires we randomly find an integral flow such that the expected flow along each edge matches the fractional flow. Both problems are reduced to cycle canceling, for which we develop an $O(m \\log(n^2/m))$ algorithm.

  8. Myocardial bridging in a survivor of sudden cardiac near-death: role of intracoronary doppler flow measurements and angiography during dobutamine stress in the clinical evaluation.

    OpenAIRE

    Tio, R.A.; van Gelder, I.C.; Boonstra, P.W.; Crijns, H. J.

    1997-01-01

    Extensive myocardial bridging in the left anterior descending coronary artery was found in a 46 year old survivor of sudden cardiac near-death. Positron emission tomography and dobutamine stress echocardiography revealed ischaemia in the myocardium distal to the bridging. Spasm was excluded as cause of the ischaemia by intracoronary infusion of acetylcholine. Further evaluation of the haemodynamic importance of the bridging using intracoronary Doppler flow velocity measurements revealed an ab...

  9. Immunophenotypic Characterization and Quantification of Neoplastic Bone Marrow Plasma Cells by Multiparametric Flow Cytometry and Its Clinical Significance in Korean Myeloma Patients

    OpenAIRE

    Cho, Young-Uk; Park, Chan-Jeoung; Park, Seo-Jin; Chi, Hyun-Sook; Jang, Seongsoo; Park, Sang Hyuk; Seo, Eul-Ju; Yoon, Dok Hyun; Lee, Jung-Hee; Suh, Cheolwon

    2013-01-01

    Multiparametric flow cytometry (MFC) allows discrimination between normal and neoplastic plasma cells (NeoPCs) within the bone marrow plasma cell (BMPC) compartment. This study sought to characterize immunophenotypes and quantitate the proportion of NeoPCs in BMPCs to diagnose plasma cell myeoma (PCM) and evaluate the prognostic impact of this method. We analyzed the MFC data of the bone marrow aspirates of 76 patients with PCM and 33 patients with reactive plasmacytosis. MFC analysis was per...

  10. [Development of software for the verification of patient flow through a daily clinical environment by use of the radiology information system (RIS)].

    Science.gov (United States)

    Nose, Hideo; Shiraishi, Junji

    2012-01-01

    In order to manage relationship between patients' movements and operating efficiency, we developed a special software which can make patient flow visible on a display monitor by use of actual data obtained from the radiology information system (RIS). In this software, a simple floor map of the radiology department in our hospital was drawn on the monitor and each patient was indicated with a small figure. This software was developed with commercialized computer software [Excel 2007 visual basic applications (VBA) Microsoft]. Movements of the patient figures were simulated by use of actual time data such as registration of radiology department, and start and ending time of examinations. The patient figures were moved along with predetermined flow lines every second. The movements of the patient figures were controlled by several buttons (i.e., play and stop) and setting switches for determining reproduction date and time. In conclusion, by use of this software, the patient flows could be analyzed systematically by checking efficient operation such as average waiting time of the patients and/or standby time of radiological technologists. PMID:23089836

  11. Clinical Implications of Having Reduced Mid Forced Expiratory Flow Rates (FEF25-75), Independently of FEV1, in Adult Patients with Asthma

    OpenAIRE

    Riley, Craig M.; Sally E. Wenzel; Castro, Mario; Erzurum, Serpil C.; Chung, Kian Fan; Fitzpatrick, Anne M.; Gaston, Benjamin; Israel, Elliot; Moore, Wendy C.; Bleecker, Eugene R.; Calhoun, William J.; Jarjour, Nizar N.; Busse, William W.; Peters, Stephen P.; Teague, W. Gerald

    2015-01-01

    Introduction FEF25-75 is one of the standard results provided in spirometry reports; however, in adult asthmatics there is limited information on how this physiological measure relates to clinical or biological outcomes independently of the FEV1 or the FEV1/FVC ratio. Purpose To determine the association between Hankinson’s percent-predicted FEF25-75 (FEF25-75%) levels with changes in healthcare utilization, respiratory symptom frequency, and biomarkers of distal airway inflammation. Methods ...

  12. Clinical and Experimental Research into Treatment of Hysteromyoma with Promoting Qi Flow and Blood Circulation,Softening and Resolving Hard Lump

    Institute of Scientific and Technical Information of China (English)

    桑海莉; 吴葆卿

    2004-01-01

    One hundred and twenty cases of hysteromyoma were treated with Kangfu Xiaozheng Tablet (康妇消症treatment group had a shrinking hysteromyoma and the improvement of symptoms such as irregular menstruation, pain in the waist and abdomen and so on. The total effective rate of 95.83% obtained in the treatment group was obviously higher than 82.00% in the control group (P<0.01). With the effect of eliminating symptoms, anti-coagulation, anti-inflammation and stopping pain, Kangfu Xiaozheng Tablet has been found to be a safe drug without toxicity in acute toxicology and clinical observation.

  13. Clinical usefulness of positron emission tomography in the evaluation of regional cerebral blood flow and cerebral oxygen metabolism under glycerol and carbon dioxide loadings

    Energy Technology Data Exchange (ETDEWEB)

    Tanada, Shuji; Yonekura, Yoshiharu; Senda, Michio

    1987-02-01

    Cerebral blood flow (CBF) and oxygen metabolism (CMRO/sub 2/) were studied in normal cerebral cortices by positron emission tomography using continuous inhalation method of oxygen-15 labeled carbon dioxide and oxygen, and single inhalation method of oxygen-15 labeled carbon monoxide. The values of CBF, CMRO/sub 2/, and oxygen extraction fraction (OEF) in cerebral cortices of 18 healthy normal volunteers represented 40 +- 7 ml/100 ml/min, 3.2 +- 0.5 ml O/sub 2//100 ml/min, and 0.43 +- 0.07, respectively. In cases with glycerol loading, CBF increased in 10/14 cases. Studies of 6 cases with intracranial pressure indicated the presence of mechanism by which depressed CMRO/sub 2/ improved and was kept in normal values. The loading of 5% carbon dioxide showed an increase in CBF in cases with cerebral infarction, which implied the good cerebral vascular response to the elevated arterial carbon dioxide, but no particular changes were observed in CMRO/sub 2/ which seemed to be less responsive to the elevated arterial carbon dioxide level. In cases with moyamoya disease, 5% carbon dioxide loading showed no changes in CBF and CMRO/sub 2/. This suggested the poor cerebral vascular response to the elevation of arterial carbon dioxide, while X-ray CT failed to demonstrate any abnormalities in corresponding areas. Positron emission tomography proved to have a great potentiality regarding the evaluation of the changes in cerebral blood flow and cerebral oxygen metabolism under various loadings.

  14. Clinical evaluation of leukocyte differential count in peripheral blood by five-color flow cytometry%五色流式细胞术分类计数外周血白细胞的临床评价

    Institute of Scientific and Technical Information of China (English)

    邢莹; 王建中; 普程伟; 尚柯

    2013-01-01

    目的 评价五色流式细胞术分类计数外周血白细胞的临床应用价值.方法 选取2010年9至12月北京大学第一医院就诊的265例患者静脉全血标本,以显微镜检查为参考方法,同时用LH750全自动血细胞分析仪和FC500流式细胞仪分类计数白细胞,统计分析显微镜、血细胞分析仪和流式细胞术分类计数外周血白细胞的相关性.选取2010年8至11月北京大学第一医院、北京市道培医院和北京军区总医院的40例患者的静脉全血标本,以显微镜检查为参考方法,同时用LH750全自动血细胞分析仪和NAVIOS流式细胞仪分类计数白细胞,统计分析显微镜、血细胞分析仪和流式细胞术分类计数外周血白细胞的相关性和流式细胞术的临床诊断效率.结果 FC500流式细胞仪采用仪器自动分析软件进行分类,与显微镜分类计数5种白细胞均具有一定相关性(均P<0.01),其中以淋巴细胞、中性粒细胞和嗜酸粒细胞的相关性最佳(r=0.955、0.928、0.876).NAVIOS 流式细胞仪采用手工输入设门策略进行分类,与显微镜方法比较除嗜碱粒细胞外均具有良好的相关性(r >0.700,均P<0.01),其中对检出中性粒细胞、淋巴细胞和原始细胞的相关性较高(r=0.950、0.915、0.852).以显微镜法分类计数外周血不成熟粒细胞1%为临界值,流式细胞术检出不成熟粒细胞的敏感度为87%,特异度为76%.以显微镜法检查外周血原始细胞0.5%为临界值,流式细胞术检出的敏感度为100%,特异度为92%.结论 应用五色流式细胞术在不同流式细胞仪上分类计数外周血白细胞与显微镜法均具有良好的相关性,对检出原始细胞和不成熟粒细胞具有较高的敏感度.%Objective To explore the clinical application values of five-color flow cytometry for leukocyte differential count in peripheral blood.Methods Leukocyte differentiation in 265 peripheral blood samples collected at

  15. Clinical evaluation of sup 99m Tc ethyl cysteinate dimer SPECT in patients with spinocerebellar degeneration; Comparison with cerebral blood flow determined by PET

    Energy Technology Data Exchange (ETDEWEB)

    Oriuchi, Noboru; Tanaka, Makoto; Igarashi, Hitoshi (Gunma Univ., Maebashi (Japan). School of Medicine) (and others)

    1992-06-01

    Technetium-99m ethyl cysteinate dimer ({sup 99m}Tc-ECD) is regarded as a promising radiopharmaceutical for imaging regional cerebral blood flow (rCBF). We evaluated {sup 99m}Tc-ECD SPECT comparing with rCBF images obtained by PET in 12 patients with spinocerebellar degeneration (SCD). SPECT images of {sup 99m}Tc-ECD demonstrated characteristic findings of decreased rCBF in bilateral cerebellar hemisphere and almost identical with PET rCBF images in all patients based on the visual inspection. Semiquantitative analysis by drawing 14 intracranial regions of interest on SPECT and PET images revealed linear correlation between {sup 99m}Tc-ECD count and rCBF measured by PET even in relatively high rCBF regions. In summary, {sup 99m}Tc-ECD is a promising tracer for evaluating rCBF in patients with SCD and distribution of it correlates well with rCBF measured by PET. (author).

  16. Visualising patient flow.

    Science.gov (United States)

    Jensen, Andrew; Boyle, Justin; Khanna, Sankalp

    2012-01-01

    We describe the development of a method to distil routinely collected clinical data into patient flow information to aid hospital bed management. Using data from state-wide emergency department and inpatient clinical information systems, a user-friendly interface was developed to visualise patient flow conditions for a particular hospital. The historical snapshots employ a variable time scale, allowing flow to be visualised across a day, week, month or year. Flow information includes occupancy, arrival and departure rates, length-of-stay and access block observations, which can be filtered by age, departure status, diagnosis, elective status, triage category, and admission unit. The tool may be helpful in supporting hospital bed managers in their daily decision making. PMID:22797023

  17. Semi-quantitative assessment of cerebral blood flow with {sup 99m}Tc-HMPAO SPET in type I diabetic patients with no clinical history of cerebrovascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Quirce, R.; Carril, J.M.; Jimenez-Bonilla, J.F.; Amado, J.A.; Gutierrez-Mendiguchia, C.; Banzo, I.; Blanco, I.; Uriarte, I.; Montero, A. [Servicio de Medicina Nuclear, Hospital Universitario Marques de Valdecilla, Santander (Spain)

    1997-12-01

    In 65 type I diabetic patients we prospectively evaluated brain perfusion by means of single-photon emission tomography after the injection of 740- 1110 MBq of technetium-99m hexamethylpropylene amine oxime. Thirty-five of the patients presented complications secondary to their diabetes. None showed CNS symptoms. A semiquantitative analysis was performed drawing 50 symmetrical regions of interest (ROIs) per patient. The relative contribution of each ROI to the total blood flow in each slice was compared with the relative contribution of the same ROI in a control group of ten healthy volunteers. Relative values of any ROI in the study group higher or lower than the mean {+-}2 SD in respect of the same ROI in the control group were considered abnormal. The results revealed hypoperfusion in 207 ROIs in the 65 patients with diabetes mellitus: of these ROIs, 113 were frontal, 10 frontotemporal, 20 temporal, 18 parietal, 11 occipital and 35 cerebellar. A total of 137 ROIs showed hyperperfusion: 17 frontal, 3 frontotemporal, 19 temporal, 18 parietal, 19 parieto-occipital, 29 occipital and 32 cerebellar. Out of 65 type I diabetic patients, 61 showed at least one hypoperfused ROI (P = 0.0064 vs. controls) and 25 showed more than three hypoperfused ROIs. None of the control subjects showed more than three hypoperfused regions (P<0.001). The results obtained demonstrate the existence of subclinical abnormalities of brain blood perfusion in patients with type I diabetes mellitus and no history of cerebrovascular disease, thereby allowing the initiation of intensive preventive measures. (orig.) With 3 figs., 5 tabs., 33 refs.

  18. Semi-quantitative assessment of cerebral blood flow with 99mTc-HMPAO SPET in type I diabetic patients with no clinical history of cerebrovascular disease

    International Nuclear Information System (INIS)

    In 65 type I diabetic patients we prospectively evaluated brain perfusion by means of single-photon emission tomography after the injection of 740- 1110 MBq of technetium-99m hexamethylpropylene amine oxime. Thirty-five of the patients presented complications secondary to their diabetes. None showed CNS symptoms. A semiquantitative analysis was performed drawing 50 symmetrical regions of interest (ROIs) per patient. The relative contribution of each ROI to the total blood flow in each slice was compared with the relative contribution of the same ROI in a control group of ten healthy volunteers. Relative values of any ROI in the study group higher or lower than the mean ±2 SD in respect of the same ROI in the control group were considered abnormal. The results revealed hypoperfusion in 207 ROIs in the 65 patients with diabetes mellitus: of these ROIs, 113 were frontal, 10 frontotemporal, 20 temporal, 18 parietal, 11 occipital and 35 cerebellar. A total of 137 ROIs showed hyperperfusion: 17 frontal, 3 frontotemporal, 19 temporal, 18 parietal, 19 parieto-occipital, 29 occipital and 32 cerebellar. Out of 65 type I diabetic patients, 61 showed at least one hypoperfused ROI (P = 0.0064 vs. controls) and 25 showed more than three hypoperfused ROIs. None of the control subjects showed more than three hypoperfused regions (P<0.001). The results obtained demonstrate the existence of subclinical abnormalities of brain blood perfusion in patients with type I diabetes mellitus and no history of cerebrovascular disease, thereby allowing the initiation of intensive preventive measures. (orig.)

  19. Clinical Implications of Having Reduced Mid Forced Expiratory Flow Rates (FEF25-75, Independently of FEV1, in Adult Patients with Asthma.

    Directory of Open Access Journals (Sweden)

    Craig M Riley

    Full Text Available FEF25-75 is one of the standard results provided in spirometry reports; however, in adult asthmatics there is limited information on how this physiological measure relates to clinical or biological outcomes independently of the FEV1 or the FEV1/FVC ratio.To determine the association between Hankinson's percent-predicted FEF25-75 (FEF25-75% levels with changes in healthcare utilization, respiratory symptom frequency, and biomarkers of distal airway inflammation.In participants enrolled in the Severe Asthma Research Program 1-2, we compared outcomes across FEF25-75% quartiles. Multivariable analyses were done to avoid confounding by demographic characteristics, FEV1, and the FEV1/FVC ratio. In a sensitivity analysis, we also compared outcomes across participants with FEF25-75% below the lower limit of normal (LLN and FEV1/FVC above LLN.Subjects in the lowest FEF25-75% quartile had greater rates of healthcare utilization and higher exhaled nitric oxide and sputum eosinophils. In multivariable analysis, being in the lowest FEF25-75% quartile remained significantly associated with nocturnal symptoms (OR 3.0 [95%CI 1.3-6.9], persistent symptoms (OR 3.3 [95%CI 1-11], ICU admission for asthma (3.7 [1.3-10.8] and blood eosinophil % (0.18 [0.07, 0.29]. In the sensitivity analysis, those with FEF25-75%

  20. Evaluation of combined, conservative treatment impact on the clinical course, blood flow parameters and muscle perfusion in the group of patients with newly diagnosed, untreated peripheral arterial disease (PAD)

    International Nuclear Information System (INIS)

    Background: Epidemiological studies determined incidence of obliterative atherosclerosis as ranging between 2.45 -10 %. The course of disease is often asymptomatic and demonstration of symptoms occurs when vascular lesions are significantly advanced. This article discusses conservative treatment of patients with PAD whose key complaint was intermittent claudication. The Authors proposed multi-stage treatment regimen of this disease including lifestyle modification, treatment of comorbid disorders, and pharmacotherapy (aspirin, pentoxifylline, buflomedil, L-arginine). The study evaluated influence of 6-month treatment on clinical course, blood flow parameters as well as muscle perfusion. Material/Methods: The participants included 35 patients (14 women - 40.0 %, and 21 men - 60.0 %) aged from 49 to 80 (mean age 68.37 ± 10.25 years) first time in life diagnosed with PAD. Physical examination, standard vascular tests (ankle-brachial, thigh-ankle and thigh-shin indices, maximum flow velocity, PI and RI in selected arteries), perfusion scintigraphy of lower limbs muscles at rest and on exertion were carried out before and after 6 months of treatment. Results: Statistically significant increase of total walking distance (198.0 meters vs. 330.0 meters, p< 0.01) and improvement in average values of perfusion indices of all studied areas were detected at rest and after exercise. For shin perfusion index at rest (right and left) and for thigh perfusion index after exercise (right) the difference was statistically significant at p< 0.05. Conclusions: Combined medical treatment brought on positive effect on patients suffering from recently diagnosed, thus not yet treated atherosclerotic lower limb ischaemia of IIA and IIB stages according to Fontaines scale. (authors)

  1. Flow visualization

    CERN Document Server

    Merzkirch, Wolfgang

    1974-01-01

    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  2. CLINICAL BIOCHEMISTRY

    Science.gov (United States)

    Assessment of the health status of animals through measurement of cellular, biochemical, and macromolecular constituents in blood, secretions, and excretions has been variously referred to as clinical chemistry, clinical biochemistry, or clinical pathology. he genesis of this dis...

  3. Flow phenomena

    International Nuclear Information System (INIS)

    Few aspects of magnetic resonance (MR) imaging are as potentially confusing as the effect of motion on the MR image. While the MR image is anatomically similar to the image produced by CT, the MR appearance of flowing blood has no correlate in CT. Flowing blood can appear bright or dark, depending on the velocity and direction of flow. To a first approximation, rapidly flowing blood appears dark ('flow void') and slowly flowing blood appears bright. This phenomenon is illustrated. This appearance is markedly influenced by factors related to the imaging sequence and to the MR imager itself. The signal from flowing blood depends on the position of the slice relative to the rest of the multislice imaging volume. It depends on the repetition time TR, the echo-delay time TE, the echo number, and the slice thickness. In fast scanning techniques with short repetition times, gradient echoes, and flip angles less than 90 degrees, flow has a different appearance than on standard 90 degrees/180 degrees spin-echo images. The principles which affect the appearance of flowing blood also affect the appearance of flowing cerebrospinal fluid (CSF). Examples of CSF flow phenomena are given

  4. Clinical biophysics

    Energy Technology Data Exchange (ETDEWEB)

    Anbar, M.; Spangler, R.A.; Scott, P.

    1985-01-01

    Chapters are included on clinical decision making, principles of biomedical engineering, computers and their medical uses, clinical radiobiology, diagnostic x-ray radiology, clinical applications of ultrasonics, nuclear medicine, NMR imaging, diagnostic imaging, bioelectric techniques in diagnosis and therapy, biophysical aspects of the clinical laboratory, and biophysical aspects of modern surgery.

  5. Preliminary validation of direct detection of foot-and-mouth disease virus within clinical samples using reverse transcription loop-mediated isothermal amplification coupled with a simple lateral flow device for detection.

    Directory of Open Access Journals (Sweden)

    Ryan A Waters

    Full Text Available Rapid, field-based diagnostic assays are desirable tools for the control of foot-and-mouth disease (FMD. Current approaches involve either; 1 Detection of FMD virus (FMDV with immuochromatographic antigen lateral flow devices (LFD, which have relatively low analytical sensitivity, or 2 portable RT-qPCR that has high analytical sensitivity but is expensive. Loop-mediated isothermal amplification (LAMP may provide a platform upon which to develop field based assays without these drawbacks. The objective of this study was to modify an FMDV-specific reverse transcription-LAMP (RT-LAMP assay to enable detection of dual-labelled LAMP products with an LFD, and to evaluate simple sample processing protocols without nucleic acid extraction. The limit of detection of this assay was demonstrated to be equivalent to that of a laboratory based real-time RT-qPCR assay and to have a 10,000 fold higher analytical sensitivity than the FMDV-specific antigen LFD currently used in the field. Importantly, this study demonstrated that FMDV RNA could be detected from epithelial suspensions without the need for prior RNA extraction, utilising a rudimentary heat source for amplification. Once optimised, this RT-LAMP-LFD protocol was able to detect multiple serotypes from field epithelial samples, in addition to detecting FMDV in the air surrounding infected cattle, pigs and sheep, including pre-clinical detection. This study describes the development and evaluation of an assay format, which may be used as a future basis for rapid and low cost detection of FMDV. In addition it provides providing "proof of concept" for the future use of LAMP assays to tackle other challenging diagnostic scenarios encompassing veterinary and human health.

  6. 流式细胞术检测HLA-B27及其临床意义%Detection of HLA-B27 by flow cytometry and it's clinical evaluation

    Institute of Scientific and Technical Information of China (English)

    金明威; 陈哲; 陈颖

    2011-01-01

    Objective: To study the clinical evaluation of HLA -B27 detection by flow cytometry (FCM) for diagnosing ankylostomiasis.Methods: 41 patients with AS, 62 patients with lumbago and 112 normal people were analyzed by FCM.Results: HLA -B27 were positive in 38 (92.6% ); among 41 patients with AS, 6 (9.67% ) of 62 patients with lumbago and 2 ( 1.78% ) of 112 normal persons.Conclusions: The positive rate of HLA - B27 in patients with AS is obviously higher than that of other groups.The detection of HLA - B27 by FCM can play an important role in diagnosing AS.%目的 通过流式细胞术检测外周血白细胞HLA-B27的表达,并探讨其时强直性脊柱炎(AS)的诊断价值.方法 利用流式细胞仪(FCM)检测41例AS患者、62例背痛及腰腿痛患者及112例健康体检者的外周血HLA-B27表达.结果 41例AS患者中,HLA阳性38例(92.6%);62例背痛腰腿痛患者中,HLA-B27阳性6例(9.67%);112例健康人群中,HLA-B27阳性2例(1.78%).结论 AS患者HLA-B27阳性率明显增高,HLA-B27检测可视为临床支持AS诊断的重要依据.

  7. Geological flows

    CERN Document Server

    Bratkov, Yu N

    2008-01-01

    In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.

  8. Rotating flow

    CERN Document Server

    Childs, Peter R N

    2010-01-01

    Rotating flow is critically important across a wide range of scientific, engineering and product applications, providing design and modeling capability for diverse products such as jet engines, pumps and vacuum cleaners, as well as geophysical flows. Developed over the course of 20 years' research into rotating fluids and associated heat transfer at the University of Sussex Thermo-Fluid Mechanics Research Centre (TFMRC), Rotating Flow is an indispensable reference and resource for all those working within the gas turbine and rotating machinery industries. Traditional fluid and flow dynamics

  9. Clinical Doppler ultrasound

    International Nuclear Information System (INIS)

    The authors begin with the basics: how Doppler signals are formed, reflected, and refracted - and how those facts apply to clinical practice; anatomy (blood and blood flow), the Doppler equation (explained from a radiologic, rather than a mathematical, perspective); and approaches to Doppler signal production. The available methods of signal processing - including audio, multifilter analysis, zero-crossing detection, autocorrelation, and the Fast Fourier Transform, as well as more sophisticated techniques of duplex and color flow imaging - are covered with an eye to helping the ultrasonographer obtain the most reliable and artifact-free information from every Doppler reading

  10. Vortical flows

    CERN Document Server

    Wu, Jie-Zhi; Zhou, Ming-De

    2015-01-01

    This book is a comprehensive and intensive book for graduate students in fluid dynamics as well as scientists, engineers and applied mathematicians. Offering a systematic introduction to the physical theory of vortical flows at graduate level, it considers the theory of vortical flows as a branch of fluid dynamics focusing on shearing process in fluid motion, measured by vorticity. It studies vortical flows according to their natural evolution stages,from being generated to dissipated. As preparation, the first three chapters of the book provide background knowledge for entering vortical flows. The rest of the book deals with vortices and vortical flows, following their natural evolution stages. Of various vortices the primary form is layer-like vortices or shear layers, and secondary but stronger form is axial vortices mainly formed by the rolling up of shear layers.  Problems are given at the end of each chapter and Appendix, some for helping understanding the basic theories, and some involving specific ap...

  11. MR imaging, flow and motion

    Energy Technology Data Exchange (ETDEWEB)

    Staahlberg, F.; Ericsson, A.; Nordell, B.; Thomsen, C.; Henriksen, O.; Persson, B.R.R. (Lund Univ. Hospital (Sweden). Depts. of Diagnostic Radiology and Radiation Physics Hvidovre Hospital (Denmark). Danish Research Center of Magnetic Resonance Akademiska Sjukhuset, Uppsala (Sweden). Dept. of Diagnostic Radiology Karolinska Sjukhuset, Stockholm (Sweden). Dept. of Hospital Physics)

    1992-05-01

    The present work is intended as a nonmatheamtical review of the role of flow and motion in nuclear magnetic resonannce (MR) imaging. A historical review of MR flow measurement techniques is given, followed by a short overview of flow models in vitro and vivo. The theory behind the influence of motion on the modulus and phase MR signal information is discussed and effects such as washin/washout, flow-induced signal void, phase offset, and phase dispersion are defined. A simple approach to the concept of MR angiography is given, and methods for quantitative flow measurements such as the phase mapping technique, are surveyed. Aspects of the measurement of diffusion and microcirculation are given, and finally, an overview of the role of MR flow imaging in present and future clinical application is given. (orig.) With 143 refs.

  12. Endovascular blood flow measurement system

    Science.gov (United States)

    Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    In this paper an endovascular measurement system used for intraoperative cerebral blood flow monitoring is described. The system is based on a Volcano ComboMap Pressure and Flow System extended with analogue-to-digital converter and PC laptop. A series of measurements performed in patients with cerebrovascular pathologies allows us to introduce “velocity-pressure” and “flow rate-energy flow rate” diagrams as important characteristics of the blood flow. The measurement system presented here can be used as an additional instrument in neurosurgery for assessment and monitoring of the operation procedure. Clinical data obtained with the system are used for construction of mathematical models and patient-specific simulations. The monitoring of the blood flow parameters during endovascular interventions was approved by the Ethics Committee at the Meshalkin Novosibirsk Research Institute of Circulation Pathology and included in certain surgical protocols for pre-, intra- and postoperative examinations.

  13. Clinical Trials

    Science.gov (United States)

    Clinical trials are research studies that test how well new medical approaches work in people. Each study answers ... prevent, screen for, diagnose, or treat a disease. Clinical trials may also compare a new treatment to a ...

  14. Clinical Research and Clinical Trials

    Science.gov (United States)

    ... Meetings, Conferences & Events Partnering & Donating to the NICHD Staff Directory ... Clinical Research Skip sharing on social media links Share this: Page Content Clinical research is research that directly involves a ...

  15. Flow cytogenetics

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Kubaláková, Marie; Vrána, Jan; Bartoš, Jan

    New York : www.dekker.com, 2004 - (Goodman, R.), s. 460-463 ISBN 0-8247-4268-0 R&D Projects: GA ČR GA521/04/0607; GA ČR GA521/03/0595; GA ČR GA522/03/0354; GA ČR GA204/04/1207 Institutional research plan: CEZ:AV0Z5038910 Keywords : flow cytogenetics * flow cytometry * chromosome sorting Subject RIV: EB - Genetics ; Molecular Biology

  16. Retirement Flows

    OpenAIRE

    Alan L. Gustman; Thomas L. Steinmeier

    1983-01-01

    This paper considers labor market flows of older workers among the states of nonretirement, partial retirement and full retirement.Statistics are presented which describe entry, exit and continuation rates for each state by age, duration dependence, and "reverse flows."One important finding which has implications for the structure of utility functions embedded in life cycle retirement models is the relatively high incidence but short duration of partial retirement.These implications are discu...

  17. Flow assurance

    Energy Technology Data Exchange (ETDEWEB)

    Mullins, O.C.; Dong, C. [Schlumberger-Doll Research Center, Cambridge, MA (United States); Elshahawi, H. [Shell Exploration and Production Company, The Hague (Netherlands)

    2008-07-01

    This study emphasized the need for considering flow assurance for producing oil and gas, particularly in high cost areas such as deepwater. Phase behaviour studies, sticking propensities, and interfacial interactions have been investigated in many laboratory studies using asphaltenes, wax, hydrates, organic and inorganic scale, and even diamondoids. However, the spatial variation of reservoir fluids has received little attention, despite the fact that it is one of the most important factors affecting flow assurance. This issue was difficult to address in a systematic way in the past because of cost constraints. Today, reservoir fluid variation and flow assurance can be considered at the outset of a project given the technological advances in downhole fluid analysis. This study described the origins of reservoir fluid compositional variations and the controversies surrounding them. It also described the indispensable chemical analytical technology. The impact of these reservoir fluid compositional variations on flow assurance considerations was also discussed. A methodology that accounts for these variations at the outset in flow assurance evaluation was also presented.

  18. Vortical flows

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jie-Zhi [Peking Univ., Beijing (China). College of Engineering; Ma, Hui-Yang [Univ. of Chinese Academy of Sciences, Beijing (China). Dept. of Physics; Zhou, Ming-De [Arizona Univ., Tucson, AZ (United States). Dept. of Aerospace and Mechanical Engineering

    2015-11-01

    This book is a comprehensive and intensive book for graduate students in fluid dynamics as well as scientists, engineers and applied mathematicians. Offering a systematic introduction to the physical theory of vortical flows at graduate level, it considers the theory of vortical flows as a branch of fluid dynamics focusing on shearing process in fluid motion, measured by vorticity. It studies vortical flows according to their natural evolution stages,from being generated to dissipated. As preparation, the first three chapters of the book provide background knowledge for entering vortical flows. The rest of the book deals with vortices and vortical flows, following their natural evolution stages. Of various vortices the primary form is layer-like vortices or shear layers, and secondary but stronger form is axial vortices mainly formed by the rolling up of shear layers. Problems are given at the end of each chapter and Appendix, some for helping understanding the basic theories, and some involving specific applications; but the emphasis of both is always on physical thinking.

  19. Vortical flows

    International Nuclear Information System (INIS)

    This book is a comprehensive and intensive book for graduate students in fluid dynamics as well as scientists, engineers and applied mathematicians. Offering a systematic introduction to the physical theory of vortical flows at graduate level, it considers the theory of vortical flows as a branch of fluid dynamics focusing on shearing process in fluid motion, measured by vorticity. It studies vortical flows according to their natural evolution stages,from being generated to dissipated. As preparation, the first three chapters of the book provide background knowledge for entering vortical flows. The rest of the book deals with vortices and vortical flows, following their natural evolution stages. Of various vortices the primary form is layer-like vortices or shear layers, and secondary but stronger form is axial vortices mainly formed by the rolling up of shear layers. Problems are given at the end of each chapter and Appendix, some for helping understanding the basic theories, and some involving specific applications; but the emphasis of both is always on physical thinking.

  20. 咀嚼对脑血流动力学影响的临床实验研究%Clinical experimental study on the effects of mastication on the dynamics of cerebral blood flow

    Institute of Scientific and Technical Information of China (English)

    魏洁; 陈树国; 徐璟; 郭长军; 袁硕

    2011-01-01

    目的 观察正常(铪)受试者咀嚼运动前后脑血流的改变,探讨咀嚼对脑血流动力学的影响及意义.方法 应用经颅彩色多谱勒超声扫描仪(transcranial color doppler,TCCD),探测30名正常(胎)受试者在安静状态下和咀嚼无糖口香糖10分钟后脑血流速的改变,对大脑中动脉收缩期峰流速(systolic peak flow velocity,Vs)、舒张期末峰流速(enddiastolic peak flow velocity,Vd)、平均峰流速(mean peak flow velocity,Vm)进行统计分析.结果 ①30名受试者咀嚼前脑血流速值均数(单位:cm/s):收缩期峰流速(Vs)-91.785,舒张期末峰流速(Vd)-39.385,平均峰流速(Vm)-55.735;咀嚼后均数:收缩期峰流速(Vs)-103.030,舒张期末峰流速(Vd)-46.015,平均峰流速(Vm)-64.090;②经两样本均数f检验可知咀嚼前后的大脑中动脉的收缩期峰流速(Vs)、舒张期末峰流速(Vd)、平均峰流速(Vm)的结果在男性与女性之间均无显著性差异(P>0.05);③受试者咀嚼前后配对t检验结果显示,受试者咀嚼后大脑中动脉收缩期峰流速(Vs)、舒张期末峰流速(Vd)及平均峰流速(Vm)与咀嚼前相比均有显著性差异(P<o.05).结论 咀嚼可使大脑中动脉血管充盈度增加,血流速度显著加快.%Objective To observe the cerebral blood flow changes of normal occlusion subjects before and after the movement of chewing, and to investigate the effects and significance of chewing on cerebral blood flow dynamics. Methods Transcranial Color Doppler (TCCD) was used to detect the changes of cerebral blood flow in 30 normal occlusion subjects in a quiet state and 10 minutes after chewing sugarless gum, and the systolic peak flow velocity (Vs), enddiastolic peak flow velocity (Vd), mean peak flow velocity (Vm) were all statistically analyzed. Results (Dthe mean value of cerebral blood flow of 30 subjects before chewing (unit: cm/s): systolic peak flow velocity (Vs) -91.785, enddiastolic peak flow velocity (Vd) -39.385, and

  1. The Effect of Pentoxifylline on bcl-2 Gene Expression Changes in Hippocampus after Ischemia-Reperfusion in Wistar Rats by a Quatitative RT-PCR Method

    OpenAIRE

    Sari, Soyar; Hashemi, Mehrdad; Mahdian, Reza; Parivar, Kazem; Rezayat, Mehdi

    2013-01-01

    Ischemia-reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. Ischemia-reperfusion brain injury initiates an inflammatory response involving the expression of adhesion molecules and cytokines. Twenty–four male Wistar rats (250-300 g body wt) were used in this study. The animals were divided into four groups of 6 rats each: I: Control group that was subjected to ischemia-reperfusion, II: Ischemia-reperfusion group ...

  2. 流式细胞术检测急性髓细胞白血病微小残留病的临床价值%Clinical Value of Flow Cytometry for Minimal Residual Disease of Acute Myeloid Leukemia

    Institute of Scientific and Technical Information of China (English)

    何正梅; 陶善东; 邓媛; 于亮

    2014-01-01

    Objective To explore the clinical value of flow cytometry for minimal residual disease of acute myeloid leu -kemia.Methods 66 cases of patients with AML ’ s myeloid antigen positive expression were detected by FCM .Results The positive expression rate of myeloid antigen in patients with AML was (19.98 ±11.98)%,and the highest positive expression rate were M2 subtype and medullary system antigen MPO;At the end of the induction chemotherapy ,46 cases had remission ,and 20 cases had no remission.The positive expression rate of myeloid antigen in the remission group was (10.50 ±10.49)%,and the positive expression rate in the non-remission group was (16.80 ±17.39)%.The highest positive expression was MPO .The posi-tive expression rate of medullary system total antigen in the remission group and the non-remission group were higher than that of the control group(P<0.05);The positive expression rate of medullary system total antigen in the remission group were lower than that of the non-remission group(P<0.05).Conclusion Detection of 9 kinds of myeloid antibodies for the patients with AML has good effect ,and it can provide reliable basis for chemotherapy regimens and therapeutic effect .%目的:探讨流式细胞术检测急性髓细胞白血病微小残留病的临床价值。方法采用FCM检测66例初治AML患者诱导化疗前后各亚型髓系抗原阳性表达情况。结果初诊时66例AML患者髓系抗原阳性总表达率为(19.98±11.98)%,M2亚型和髓系抗原MPO阳性表达率最高;诱导化疗结束时46例缓解、20例未缓解。髓系抗原缓解组阳性总表达率为(10.50±10.49)%,未缓解组阳性总表达率为(16.80±17.39)%,2组MPO阳性表达率最高。缓解组与未缓解组患者髓系抗原总阳性表达率均显著高于对照组,差异具有统计学意义(P<0.05);缓解组患者髓系抗原总阳性表达率显著低于未缓解组,差异具有统计学意义(P<0.05

  3. Granular flow

    DEFF Research Database (Denmark)

    Mitarai, Namiko; Nakanishi, Hiizu

    2012-01-01

    Granular material is a collection of macroscopic particles that are visible with naked eyes. The non-equilibrium nature of the granular materials makes their rheology quite different from that of molecular systems. In this minireview, we present the unique features of granular materials focusing ...... the shear flow of dry granular materials and granule-liquid mixture....

  4. Atlas-based analysis of 4D flow CMR: Automated vessel segmentation and flow quantification

    OpenAIRE

    Bustamante, Mariana; Petersson, Sven; Eriksson, Jonatan; Alehagen, Urban; Dyverfeldt, Petter; Carlhäll, Carljohan; Ebbers, Tino

    2015-01-01

    Background Flow volume quantification in the great thoracic vessels is used in the assessment of several cardiovascular diseases. Clinically, it is often based on semi-automatic segmentation of a vessel throughout the cardiac cycle in 2D cine phase-contrast Cardiovascular Magnetic Resonance (CMR) images. Three-dimensional (3D), time-resolved phase-contrast CMR with three-directional velocity encoding (4D flow CMR) permits assessment of net flow volumes and flow patterns retrospectively at any...

  5. A Curvature Flow Unifying Symplectic Curvature Flow And Pluriclosed Flow

    OpenAIRE

    DAI, SONG

    2013-01-01

    Streets and Tian introduced pluriclosed flow and symplectic curvature flow in recent years. Here we construct a curvature flow to unify these two flows. We show the short time existence of our flow and exhibit an obstruction to long time existence.

  6. Prognostic value of fractional flow reserve

    DEFF Research Database (Denmark)

    Johnson, Nils P; Tóth, Gábor G; Lai, Dejian;

    2014-01-01

    BACKGROUND: Fractional flow reserve (FFR) has become an established tool for guiding treatment, but its graded relationship to clinical outcomes as modulated by medical therapy versus revascularization remains unclear. OBJECTIVES: The study hypothesized that FFR displays a continuous relationship...

  7. Clinical Research

    DEFF Research Database (Denmark)

    Christensen, Irene

    2016-01-01

    This paper is about the logic of problem solving and the production of scientific knowledge through the utilisation of clinical research perspective. Ramp-up effectiveness, productivity, efficiency and organizational excellence are topics that continue to engage research and will continue doing so...... for years to come. This paper seeks to provide insights into ramp-up management studies through providing an agenda for conducting collaborative clinical research and extend this area by proposing how clinical research could be designed and executed in the Ramp- up management setting....

  8. Hydrodynamics, flow, and flow fluctuations

    International Nuclear Information System (INIS)

    The matter formed in heavy-ion collisions has been shown to interact so strongly that it behaves like a relativistic fluid during its expansion. I show that initial-state fluctuations, due to the nucleonic structure of incoming nuclei, have a large effect of flow observables. I argue that these fluctuations do not reduce to eccentricity fluctuations. (author)

  9. CLINICAL OBSERVATION ABOUT THE EFFECT OF BLOOD-LETTING OF JING-POINTS ON CEREBRAL BLOOD FLOW IN STROKE PATIENTS AT THE EARLY STAGE AND EXPERIMENTAL STUDY ON ITS MECHANISMS IN THE RABBIT

    Institute of Scientific and Technical Information of China (English)

    WANG Xiuyun; REN Shusheng; GUO Yi; ZHOU Guoping; ZHOU Zhiliang; PAN Rongqing; XU Tangping; LI Qing; WANG Xin; REN Huanzhong

    2002-01-01

    In this paper,the authors sum their research resuits about the effect of blood-letting of Jing(Well)-point on cerebral blood flow both in stroke patients and in experimental cerebral ischemia,cerebral hematoma and hypertension rabbits.In 30cases of stroke (cerebral hemorrhage and cerebral infarction)patients,blood flow state of the anterior cerebral artery(ACA),middle cerebral artery(MCA)and the posterior cerebral artery (PCA), and the blood flow velocity of the bilateral vertebral artery (VA)and the basil artery(BA)are determined before and afterpricking blood of the Twelve Jing-points.In experimental cerebral ischernia (by occlusion of the common carotid ertery) rabbits ,cerebral hematoma model rabbits and intravenous injection of noradrenaline induced hypertension rabbits, rheoencephalogram(REC) is detected before and after blood letting of the twelve"Jing -points.In these 30stroke patients,ultrasound Doppler examination's results show that in 22 cases (73.33%) whose blood flow velocity decreases,after blood-letting of the 12 Jing-points, it ncreases significantly(P< 0.01); in the rest 8 cases (26.67%) whose blood flow velocity speeds up,after treatment,it decreases evidently(P<tly (P< 0.01), showing a good dual-directional regulative effect of blood -letting therapy.In experimental cerebral ischemia rabbits,cerebral hematoma rabbits and hypertension rabbits whose REG lowers in the amplitude apparently ( P < 0.01 ), after blood letting stimulation of the 12 Jing-points, it increases at different degrees.Three patterns of stimulation as blood letting stimulation, pain stimulation and Jing-point stimulation, also the 3factors of blood-letting,may contribute to their effect on improvement of the cerebral blood flow.Somatic affterent nerve,sympathetic nerve of the vasular wall,central cholinergic nerve(M receptors)and adrenergic nerve (α receptors) participate in the effect of blood letting on cerebral blood flow.

  10. Media Flow

    DEFF Research Database (Denmark)

    Kabel, Lars

    2015-01-01

    News and other kinds of journalistic stories, 16-17 hours a day, all year round, on all platforms, also the moderated social media. The key research thesis behind this article is that the continuous and speedy stream of news stories and media content now is becoming the centre of the production...... processes and the value creation in converged multimedia newsrooms. The article identify new methods and discuss editorial challenges in handling media flow....

  11. 多普勒超声探测胎儿肝静脉血流频谱及其临床意义%Duplex Doppler ultrasonography of fetal hepatic venous flow and its clinical significance

    Institute of Scientific and Technical Information of China (English)

    吴细香; 胡翔宇; 焦彤; 柴云生; 林永熙

    2000-01-01

    Objective To study the Doppler flow spectrum of fetal hepatic vein.Methods One hundred and twelve pregnant women of gestational age 27~42 weeks were examined by common ultrasonography,then the vein of fetal liver were investigated by two dimensional and duplex Doppler ultrasonography.Results The Doppler flow spectrum of normal fetal hepatic vein could be classified into 3 types:Type Ⅰ,68 cases,showed two negative waveforms.Type Ⅱ,23 cases showed 3-phase wavefoml,two negative and one transient positive waves,in accordance with those of adult.Type Ⅲ,21 cases,showed one negative waveform.Of all the spectra,two cases were abnormal,showing markedly increased positive flow,which Was proved to be due to congenital heart disease.Conclusions Investigaring the fetal hepatic venous flow by duplex Doppler ultrosongraphy was feasible.The Doppler flow spectrum showed that the increase in the frequence and amplitude of positive flow spectrum could be important to the diagnosis of the congenital heart disease.%目的 探讨胎儿肝静脉的多普勒血流频谱及其临床意义.方法 112例孕妇(孕龄27~42周)行常规超声检查后,对胎儿肝中静脉再行二维超声及多普勒超声检查.结果 正常胎儿肝静脉多普勒血流频谱分为三型.Ⅰ型68例,表现为二个负向波,占60.7%.Ⅱ型23例,表现为三相波即二个负向波一个短暂正向波,与正常成人一致,占21,6%.Ⅲ型21例,表现为一个负向波,占18.7%.2例胎儿肝静脉血流频谱出现异常,其正向血流明显增高,经尸检证实为先心病.结论 多普勒超声探测胎儿肝静脉血流频谱是完全可行的,其正向血流增高增多可为临床诊断胎儿某些先心病提供重要依据.

  12. Using a computerized patient record to reengineer an outpatient clinic.

    OpenAIRE

    Borowitz, S M

    1994-01-01

    By employing process flow analysis and work redesign techniques during the design and implementation of a computerized patient record in the pediatric outpatient clinics at the University of Virginia Health Sciences Center, we have developed a database of clinical observations while simultaneously shortening the time that patients spend waiting in the pediatric clinics and decreasing the number of support staff employed within the clinics.

  13. Xenon computed tomographic blood flow mapping

    International Nuclear Information System (INIS)

    Xenon CT flow information appears to be clinically useful in the diagnosis and management of a broad spectrum of clinical disorders. It also appears to be a useful tool for the experimental study of the cerebral circulation, with recent work also extending to application to the study of solid abdominal organs. The authors therefore found xenon CT CBF mapping to be a useful new blood flow methodology and are of the opinion that as CT technology improves, one will be able to obtain still better flow information with less accompanying radiation exposure and/or a reduction in the level of xenon inhalation required

  14. Continental Lower-crustal Flow: Channel Flow and Laminar Flow

    Science.gov (United States)

    LI, Dewei

    Numerous geological, geophysical and geochemical investigations and finite element modeling indicate that crustal flow layers exist in the continental crust. Both channel flow model and laminar flow model have been created to explain the flow laws and flow mechanisms. As revealed by the channel flow model, a low-viscosity channel in middle to lower crust in orogen or plateau with thick crust and high elevation would flow outward from mountain root in response to lateral pressure gradient resulted from topographic loading or to denudation. However, according to the laminar flow model proposed based on investigation of the Qinghai-Tibet plateau, circulative movement of crustal lithologies with different rheological properties between basin and orogen would occur, under the driving forces resulted from dehydration and melting of subduction plate on active continental margin and from thermal energy related to upwelling and diapiring of intercontinental mantle plume or its gravitational interactions. Similarly, when driven by gravity, the softened or melted substances of the lower crust in a basin would flow laterally toward adjacent mountain root, which would result in a thinned basin crust and a thickened orogenic crust. Partially melted magma within the thickened orogenic lower crust would cause vertical movement of metamorphic rocks of lower to middle crust due to density inversion, and the vertical main stress induced by thermal underplating of lower crust would in turn lead to formation of metamorphic core complexes and low-angle detachment fault systems. Lateral spreading of uplifting mountain due to gravitation potential would result in thrust fault systems on the border between mountain and basin. Meanwhile, detritus produced synchronously by intense erosion of uplifting mountain would be transported and deposited along the marginal deep depression in the foreland basin dragged by lower crust flow. Channel flow is similar to laminar flow in a variety of aspects

  15. Flow and Flow Decay of Refractory Castables

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhiqiang; Bjom Myhre; Bjorn Sandberg

    2003-01-01

    Installation of refractoty castables depend not only on flow, but also on how soon the flow is lost because of setting. The loss of flow (flow decay) has always been one of the main problems of refractory castable manufacturers,a problem that has not been too well described in literature. The flow decay has been studied for a castable system based on alumina, pointing out some general trends. The flow decay was found very temperature sensitive, being strongly accelerated by termperature increases. To compensate for excessive flow loss, a retarder like citric acid may be used. Thus flow decay was measured as a function of citric acid (retarder) addition at 35 ℃ .

  16. Liver angioscintigraphy: clinical applications.

    Science.gov (United States)

    Dragoteanu, Mircea; Cotul, Sabin O; Pîgleşan, Cecilia; Tamaş, Stefan

    2004-03-01

    Liver angioscintigraphy (LAS) is a radio-isotope method for the investigation of liver perfusion and its alteration in various hepatic diseases. It measures the arterial and portal venous fractions of total liver blood flow. The percentage of liver blood flow supplied by hepatic artery is estimated mathematically by the hepatic perfusion index (HPI), normally between 25 % and 40 %. The decrease of portal blood flow in liver cirrhosis is compensated ("buffer" mechanisms) by increased arterial supply, with higher HPI value. For a patient with chronic liver disease, HPI over 50% suggests arterialization of hepatic perfusion, guiding the diagnose to liver cirrhosis. Splenic curve is completing the diagnostic information of the hepatic curve. Corroborated with per rectal scintigraphy and liver SPECT, LAS offers a good hemodynamic staging of chronic inflammatory liver diseases. Malignant tumors (primitive or metastases) increase the arterial supply of the liver and decrease the portal flow, HPI being over 50% (currently 65 % - 90 %). Benign tumors do not change portal/arterial liver blood flow ratio. SPECT or non-scintigraphic morphological investigations increase the diagnostic value of LAS for primitive liver tumors. Liver cancer occurring on cirrhosis is a limitative factor for LAS. Hepatic metastases increase the arterial perfusion (and HPI value) very quickly, before their size allows morphologic imaging diagnosis. LAS is therefore an early method to diagnose liver metastases being especially used in colorectal cancer. Other clinical applications of LAS are: follow up of liver toxicity of drugs, evaluation of portal vein permeability, post surgery follow up of the liver tumor patients. PMID:15054528

  17. Clinical cases

    International Nuclear Information System (INIS)

    This presentation is about clinical cases and the contribution of the PET - CT Fag application in the diagnosis and treatment of different types of cancer. The cases presented were: neck diseases, epidermoid carcinoma, liver damage and metastasize, lymphoma, thrombosis, colonic cancer and lung disease

  18. Clinical practice

    OpenAIRE

    de Winter, J. Peter; de Vries, Machteld A. G.; Zimmermann, Luc J. I.

    2010-01-01

    The most important goal of introducing noninvasive ventilation (NIV) has been to decrease the need for intubation and, therefore, mechanical ventilation in newborns. As a result, this technique may reduce the incidence of bronchopulmonary dysplasia (BPD). In addition to nasal CPAP, improvements in sensors and flow delivery systems have resulted in the introduction of a variety of other types of NIV. For the optimal application of these novelties, a thorough physiological knowledge of mechanic...

  19. Environment Flow Assessment with Flow Regime Transition

    Science.gov (United States)

    Su, J.; Ho, C. C.; Chang, L. C.

    2015-12-01

    To avoid worsen river and estuarine ecosystems cause by overusing water resources, environmental flows conservation is applied to reduce the impact of river environment. Environmental flows refer to water provided within a river, wetland or coastal zone to sustain ecosystems and benefits to human wellbeing. Environment flow assessment is now widely accepted that a naturally variable flow regime, rather than just a minimum low flow. In this study, we propose four methods, experience method, Tenant method, hydraulic method and habitat method to assess the environmental flow of base flow, flush flow and overbank flow with different discharge, frequency and occurrence period. Dahan River has been chosen as a case to demonstrate the assessment mechanism. The alternatives impact analysis of environment and human water used provides a reference for stakeholders when holding an environmental flow consultative meeting.

  20. Clinical biochemistry

    Science.gov (United States)

    Alexander, W. C.; Leach, C. S.; Fischer, C. L.

    1975-01-01

    The objectives of the biochemical studies conducted for the Apollo program were (1) to provide routine laboratory data for assessment of preflight crew physical status and for postflight comparisons; (2) to detect clinical or pathological abnormalities which might have required remedial action preflight; (3) to discover as early as possible any infectious disease process during the postflight quarantine periods following certain missions; and (4) to obtain fundamental medical knowledge relative to man's adjustment to and return from the space flight environment. The accumulated data presented suggest that these requirements were met by the program described. All changes ascribed to the space flight environment were subtle, whereas clinically significant changes were consistent with infrequent illnesses unrelated to the space flight exposure.

  1. Flow distances on open flow networks

    Science.gov (United States)

    Guo, Liangzhu; Lou, Xiaodan; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

    2015-11-01

    An open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state mode of an open flow system. Energetic food webs, economic input-output networks, and international trade networks are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. An open flow network is different from a closed flow network because it considers the flows from or to the environment (the source and the sink). For instance, in energetic food webs, species obtain energy not only from other species but also from the environment (sunlight), and species also dissipate energy to the environment. Flow distances between any two nodes i and j are defined as the average number of transition steps of a random walker along the network from i to j. The conventional method for the calculation of the random walk distance on closed flow networks cannot be applied to open flow networks. Therefore, we derive novel explicit expressions for flow distances of open flow networks according to their underlying Markov matrix of the network in this paper. We apply flow distances to two types of empirical open flow networks, including energetic food webs and economic input-output networks. In energetic food webs, we visualize the trophic level of each species and compare flow distances with other distance metrics on the graph. In economic input-output networks, we rank sectors according to their average flow distances and cluster sectors into different industrial groups with strong connections. Other potential applications and mathematical properties are also discussed. To summarize, flow distance is a useful and powerful tool to study open flow systems.

  2. Phase Flow Rate Measurements of Annual Flows

    OpenAIRE

    Al-Yarubi, O.S.; Lucas, Gary

    2009-01-01

    The Annular flow regime makes measurement of the total liquid flow rate difficult. It is even more difficult to measure the individual flow rate of either the oil or the water. In a vertical Perspex tube (i.d. = 50 mm) using a newly-designed flow loop in the University of Huddersfield, annular flow was established and different measurements were carried out. One possible on-line measurement technique to achieve the oil volume fraction measurement is an automated bypass...

  3. Teaching Phagocytosis Using Flow Cytometry

    Directory of Open Access Journals (Sweden)

    John Boothby

    2009-12-01

    Full Text Available Investigative microbiology on protists in a basic teaching laboratory environment is limited by student skill level, ease of microbial culture and manipulation, instrumentation, and time. The flow cytometer is gaining use as a mainstream instrument in research and clinical laboratories, but has had minimal application in teaching laboratories. Although the cost of a flow cytometer is currently prohibitive for many microbiology teaching environments and the number of trained instructors and teaching materials is limited, in many ways the flow cytometer is an ideal instrument for teaching basic microbiology. We report here on a laboratory module to study phagocytosis in Tetrahymena sp. using flow cytometry in a basic microbiology teaching laboratory. Students and instructors found the flow cytometry data analysis program, Paint-A-GatePRO-TM, to be very intuitive and easy to learn within a short period of time. Assessment of student learning about Tetrahymena sp., phagocytosis, flow cytometry, and investigative microbiology using an inquiry-based format demonstrated an overall positive response from students.

  4. Clinical arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, R.; Horns, J.W.; Gold, R.H.; Blaschke, D.D.

    1985-01-01

    This book deals with the method and interpretation of arthrography of the shoulder, knee, ankle, elbow, hip, wrist, and metacarpophalangeal, interphalangeal, and temporomandibular joints. The emphasis is on orthopaedic disorders, usually of traumatic origin, which is in keeping with the application of arthrography in clinical practice. Other conditions, such as inflammatory and degenerative diseases, congenital disorders and, in the case of the hip, arthrography of reconstructive joint surgery, are included. Each chapter is devoted to one joint and provides a comprehensive discussion on the method of arthrography, including single and double contrast techniques where applicable, normal radiographic anatomy, and finally, the interpretation of the normal and the abnormal arthrogram.

  5. Effect of TIPS placement on portal and splanchnic arterial blood flow in 4-dimensional flow MRI

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, Zoran [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); University Medical Center Freiburg, Department of Diagnostic Radiology and Medical Physics, Freiburg (Germany); Roessle, Martin; Schultheiss, Michael [University Medical Center Freiburg, Department of Gastroenterology, Freiburg (Germany); Euringer, Wulf; Langer, Mathias [University Medical Center Freiburg, Department of Diagnostic Radiology and Medical Physics, Freiburg (Germany); Salem, Riad; Barker, Alex; Carr, James; Collins, Jeremy D. [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States)

    2015-09-15

    To assess changes in portal and splanchnic arterial haemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) using four-dimensional (4D) flow MRI, a non-invasive, non-contrast imaging technique. Eleven patients undergoing TIPS implantation were enrolled. K-t GRAPPA accelerated non-contrast 4D flow MRI of the liver vasculature was applied with acceleration factor R = 5 at 3Tesla. Flow analysis included three-dimensional (3D) blood flow visualization using time-resolved 3D particle traces and semi-quantitative flow pattern grading. Quantitative evaluation entailed peak velocities and net flows throughout the arterial and portal venous (PV) systems. MRI measurements were taken within 24 h before and 4 weeks after TIPS placement. Three-dimensional flow visualization with 4D flow MRI revealed good image quality with minor limitations in PV flow. Quantitative analysis revealed a significant increase in PV flow (562 ± 373 ml/min before vs. 1831 ± 965 ml/min after TIPS), in the hepatic artery (176 ± 132 ml/min vs. 354 ± 140 ml/min) and combined flow in splenic and superior mesenteric arteries (770 ml/min vs. 1064 ml/min). Shunt-flow assessment demonstrated stenoses in two patients confirmed and treated at TIPS revision. Four-dimensional flow MRI might have the potential to give new information about the effect of TIPS placement on hepatic perfusion. It may explain some unexpected findings in clinical observation studies. (orig.)

  6. Effect of TIPS placement on portal and splanchnic arterial blood flow in 4-dimensional flow MRI

    International Nuclear Information System (INIS)

    To assess changes in portal and splanchnic arterial haemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) using four-dimensional (4D) flow MRI, a non-invasive, non-contrast imaging technique. Eleven patients undergoing TIPS implantation were enrolled. K-t GRAPPA accelerated non-contrast 4D flow MRI of the liver vasculature was applied with acceleration factor R = 5 at 3Tesla. Flow analysis included three-dimensional (3D) blood flow visualization using time-resolved 3D particle traces and semi-quantitative flow pattern grading. Quantitative evaluation entailed peak velocities and net flows throughout the arterial and portal venous (PV) systems. MRI measurements were taken within 24 h before and 4 weeks after TIPS placement. Three-dimensional flow visualization with 4D flow MRI revealed good image quality with minor limitations in PV flow. Quantitative analysis revealed a significant increase in PV flow (562 ± 373 ml/min before vs. 1831 ± 965 ml/min after TIPS), in the hepatic artery (176 ± 132 ml/min vs. 354 ± 140 ml/min) and combined flow in splenic and superior mesenteric arteries (770 ml/min vs. 1064 ml/min). Shunt-flow assessment demonstrated stenoses in two patients confirmed and treated at TIPS revision. Four-dimensional flow MRI might have the potential to give new information about the effect of TIPS placement on hepatic perfusion. It may explain some unexpected findings in clinical observation studies. (orig.)

  7. 分析彩色多普勒超声对乳腺肿块的临床诊断价值%Analysis of Color Doppler Flow Imaging (CDFI) in the Value of Clinical Diagnosis of Breast Lumps

    Institute of Scientific and Technical Information of China (English)

    左桂枝

    2015-01-01

    目的:对在彩色多普勒超声下,对良恶性乳腺肿块的不同表现情况进行研究和分析。方法对我院此次所收治的103例乳腺良性病变和86例乳腺癌患者采用彩色多普勒超声进行检查。结果经过研究发现,对乳腺良性病变和乳腺癌患者采用彩色多普勒超声进行检查,其存在不同的特点。结论在临床上,对乳腺良性病变和乳腺癌患者采用彩色多普勒超声进行检查,能够为临床诊断提供一定的参考依据。%Objective To under the color doppler ultrasound, the benign and malignant breast tumors of research and analysis on the different situation. Methods In our hospital treated 103 cases of breast benign lesions and by the 86 breast cancer patients by color Doppler lfow imaging (CDFI) for inspection. Results Through the study found that patients with breast benign lesions and breast cancer using color Doppler ultrasound to check, the existence of different features. Conclusion Clinically, patients with breast benign lesions and breast cancer using color doppler ultrasound to check, can provide certain reference basis for clinical diagnosis.

  8. Group flow, complex flow, unit vector flow, and the (2+ϵ)-flow conjecture

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2014-01-01

    that every 14-edge-connected graph has a flow whose flow values are the five roots of unity in the complex plane. Any such flow is balanced modulo 5. So, if the edge-connectivity 14 can be reduced to 9, then the 5-flow conjecture follows, as observed by F. Jaeger. We use vector flow to prove that, for each...

  9. Phase flow rate measurements of annular flows

    OpenAIRE

    Al-Yarubi, Qahtan

    2010-01-01

    In the international oil and gas industry multiphase annular flow in pipelines and wells is extremely important, but not well understood. This thesis reports the development of an efficient and cheap method for measuring the phase flow rates in two phase annular and annular mist flow, in which the liquid phase is electrically conducting, using ultrasonic and conductance techniques. The method measures changes in the conductance of the liquid film formed during annular flow and uses these to c...

  10. Clinical guidelines.

    Science.gov (United States)

    Uppal, Elaine

    2016-01-01

    This article is part of the Advancing practice series which is aimed at exploring practice issues in more depth, considering topics that are frequently encountered and facilitating the development of new insights. Elaine Uppal focuses on the importance of all midwives developing guideline writing skills to ensure that local, national and international midwifery/maternity guidelines are up to date, relevant and reflect midwifery knowledge alongside 'gold' standard evidence. The article aims to consider the development, use and critical appraisal of clinical guidelines. It will define and explain guidelines; discuss their development and dissemination; and consider issues relating to their use in practice. Techniques to critique and develop guidelines using the AGREE tool will be outlined in the form of practice challenges to be undertaken by the individual or in a group. PMID:26975126

  11. MR evaluation of common femoral arterial flow

    International Nuclear Information System (INIS)

    Flow velocity measurements of the common femoral arteries in 60 lower extremities of 30 healthy subjects and 12 lower extremities of 7 patients with arteriosclerosis obliterans (ASO) were performed by means of magnetic resonance imaging with a use of presaturation bolus tracking (PBT) method. Our PBT method can provide both precise determination of flow velocity and evaluation of flow patterns within 30 minutes in the clinical setting. In phantom study, MR flow velocity had good correlation with actual flow velocity (r=0.997) 30 healthy volunteers were classified into three groups; group I (20-40 years), group II (41-60 years) and group III (61-80 years). Starting time of acceleration (STA) were shortened as the age progressed. Peak reverse velocity (PRV), maximum deceleration rate (MDR), peak forward velocity/mean velocity ratio (PFV/MV) and pulsatility index (PI) were significantly decreased in group III as compared to group I and group II. Although intraluminal flow profile showed almost uniform during acceleration time on MR images, flow profile became disproportioned and reverse flow was observed in the medial portion during deceleration time. These characteristic hemodynamics were recognized in all healthy subjects regardless of the different age group. In ASO, STA was prolonged and PFV, PRV, maximum acceleration rate, MDR, PFV/MV, PI, vascular sectional area, flow volume were significantly decreased (p<0.001) as compared to the control healthy group III. As a result, we obtained marked characteristics such as flattening of curves and disappearance of reverse flow in MR flow waveform. On MR images, disproportion of intraluminal flow profile, decreased flow velocities during acceleration time and disappearance of reverse flow (11 of 12 extremities) during deceleration time were observed. (author)

  12. The Physics of Coronary Blood Flow

    CERN Document Server

    Zamir, M

    2005-01-01

    Coronary blood flow is blood flow to the heart for its own metabolic needs. In the most common form of heart disease there is a disruption in this flow because of obstructive disease in the vessels that carry the flow. The subject of coronary blood flow is therefore associated mostly with the pathophysiology of this disease, rarely with dynamics or physics. Yet, the system responsible for coronary blood flow, namely the "coronary circulation," is a highly sophisticated dynamical system in which the dynamics and physics of the flow are as important as the integrity of the conducting vessels. While an obstruction in the conducting vessels is a fairly obvious and clearly visible cause of disruption in coronary blood flow, any discord in the complex dynamics of the system can cause an equally grave, though less conspicuous, disruption in the flow. This book is devoted specifically to the dynamics and physics of coronary blood flow. While relevance to the clinical and pathophysiological issues is clearly maintaine...

  13. Flow of Aqueous Humor

    Science.gov (United States)

    ... Facebook Twitter Google Plus Email Print this page Flow of Aqueous Humor Most, but not all, forms ... aqueous humor) produced by the eye's ciliary body flows out freely (follow blue arrow). Aqueous humor flows ...

  14. Retinal blood flow in diabetic retinopathy.

    OpenAIRE

    Patel, V.; Rassam, S; NEWSOM, R.; Wiek, J; Kohner, E.

    1992-01-01

    OBJECTIVES--(a) To report on the basic parameters of retinal blood flow in a population of diabetic patients with and without retinopathy and non-diabetic controls; (b) to formulate a haemodynamic model for the pathogenesis of diabetic retinopathy from this and other studies. DESIGN--Laser-Doppler velocimetry and computerised image analysis to determine retinal blood flow in a large cross sectional study. SETTING--Diabetic retinopathy outpatient clinic. SUBJECTS--24 non-diabetic controls and ...

  15. Advanced Analysis Techniques for Intra-cardiac Flow Evaluation from 4D Flow MRI

    OpenAIRE

    van der Geest, Rob J; Garg, Pankaj

    2016-01-01

    Purpose of the Review Time-resolved 3D velocity-encoded MR imaging with velocity encoding in three directions (4D Flow) has emerged as a novel MR acquisition technique providing detailed information on flow in the cardiovascular system. In contrast to other clinically available imaging techniques such as echo-Doppler, 4D Flow MRI provides the 3D Flow velocity field within a volumetric region of interest over the cardiac cycle. This work reviews the most recent advances in the development and ...

  16. Relaminarization of fluid flows

    International Nuclear Information System (INIS)

    The mechanisms of the relaminarization of turbulent flows are investigated with a view to establishing any general principles that might govern them. Three basic archetypes of reverting flows are considered: the dissipative type, the absorptive type, and the Richardson type exemplified by a turbulent boundary layer subjected to severe acceleration. A number of other different reverting flows are then considered in the light of the analysis of these archetypes, including radial Poiseuille flow, convex boundary layers, flows reverting by rotation, injection, and suction, as well as heated horizontal and vertical gas flows. Magnetohydrodynamic duct flows are also examined. Applications of flow reversion for turbulence control are discussed

  17. Relaminarization of fluid flows

    Science.gov (United States)

    Narasimha, R.; Sreenivasan, K. R.

    1979-01-01

    The mechanisms of the relaminarization of turbulent flows are investigated with a view to establishing any general principles that might govern them. Three basic archetypes of reverting flows are considered: the dissipative type, the absorptive type, and the Richardson type exemplified by a turbulent boundary layer subjected to severe acceleration. A number of other different reverting flows are then considered in the light of the analysis of these archetypes, including radial Poiseuille flow, convex boundary layers, flows reverting by rotation, injection, and suction, as well as heated horizontal and vertical gas flows. Magnetohydrodynamic duct flows are also examined. Applications of flow reversion for turbulence control are discussed.

  18. Flow Distances on Open Flow Networks

    CERN Document Server

    Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

    2015-01-01

    Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...

  19. Blood flow autoregulation in pedicled flaps

    DEFF Research Database (Denmark)

    Bonde, Christian T; Holstein-Rathlou, Niels-Henrik; Elberg, Jens J

    2009-01-01

    INTRODUCTION: Clinical work on the blood perfusion in skin and muscle flaps has suggested that some degree of blood flow autoregulation exists in such flaps. An autoregulatory mechanism would enable the flap to protect itself from changes in the perfusion pressure. The purpose of the present study...... was to evaluate if, and to what extent, a tissue flap could compensate a reduction in blood flow due to an acute constriction of the feed artery. Further, we wanted to examine the possible role of smooth muscle L-type calcium channels in the autoregulatory mechanism by pharmacological intervention...... with the L-type calcium channel blocker nimodipine and the vasodilator papaverine. MATERIAL AND METHODS: Pedicled flaps were raised in pigs. Flow in the pedicle was reduced by constriction of the feed artery (n=34). A transit time flow probe measured the effect on blood flow continuously. Following...

  20. Clinical Neuroimaging of cerebral ischemia

    International Nuclear Information System (INIS)

    Notice points in clinical imaging of cerebral ischemia are reviewed. When cerebral blood flow is determined in acute stage of cerebral embolism (cerebral blood flow SPECT), it is important to find area of ischemic core and ischemic penumbra. When large cortex area is assigned to ischemic penumbra, thrombolytic therapy is positively adapted, but cautious correspondence is necessary when ischemic core is recognized. DWI is superior in the detection of area equivalent to ischemic core of early stage, but, in imaging of area equivalent to ischemic penumbra, perfusion image or distribution image of cerebral blood volume (CBV) by MRI need to be combined. Luxury perfusion detected by cerebral blood flow SPECT in the cases of acute cerebral embolism suggests vascular recanalization, but a comparison with CT/MRI and continuous assessment of cerebral circulation dynamics were necessary in order to predict brain tissue disease (metabolic abnormality). In hemodynamic cerebral ischemia, it is important to find stage 2 equivalent to misery perfusion by quantification of cerebral blood flow SPECT. Degree of diaschisis can indicate seriousness of brain dysfunction for lacuna infarct. Because cerebral circulation reserve ability (perfusion pressure) is normal in all areas of the low cerebral blood flow by diaschisis mechanism, their areas are easily distinguished from those of hemodynamic cerebral ischemia. (K.H.)

  1. The Jacobi flow

    OpenAIRE

    Michor, Peter W.

    1996-01-01

    The geodesic flow on the tangent bundle is the flow of a certain vector field which is called the spray $S:TM\\to TTM$. The flow lines of the vector field $\\ka_{TM}\\o TS:TTM\\to TTTM$ project to the Jacobi fields on $TM$. This could be called the Jacobi flow.

  2. Flow Element Models

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    Air distribution in ventilated rooms is a flow process that can be divided into different elements such as supply air jets, exhaust flows, thermal plumes, boundary layer flows, infiltration and gravity currents. These flow elements are isolated volumes where the air movement is controlled by a re...... restricted number of parameters, and the air movement is fairly independent of the general flow in the enclosure. In many practical situations, the most convenient· method is to design the air distribution system using flow element theory.......Air distribution in ventilated rooms is a flow process that can be divided into different elements such as supply air jets, exhaust flows, thermal plumes, boundary layer flows, infiltration and gravity currents. These flow elements are isolated volumes where the air movement is controlled by a...

  3. Flow chemistry is starting to flow

    OpenAIRE

    Duisterwinkel, A.E.

    2012-01-01

    One good thing about this symposium on flow chemistry is that at least half of the papers was on actual applications: summarized one member of the audience of the IPIT symposium in Rotterdam, 25 May 2012. This remark can be viewed as a compliment to the organizer, TNO, a Dutch contract research organization. More importantly, it shows that flow chemistry is, slowly but steadily, being accepted in the production of fine chemicals and pharmaceutics. In order to get flow chemistry accepted in th...

  4. From Medical Records to Clinical Science

    OpenAIRE

    Aickin, Mikel; Elder, Charles

    2012-01-01

    Medical records contain an abundance of information, very little of which is extracted and put to clinical use. Increasing the flow of information from medical records to clinical practice requires methods of analysis that are appropriate for large nonintervention studies. The purpose of this article is to explain in nontechnical language what these methods are, how they differ from conventional statistical analyses, and why the latter are generally inappropriate. This is important because of...

  5. Clinically-based archive model for a picture archive and communication system

    International Nuclear Information System (INIS)

    This paper discusses the performance of the PACS. The authors present accumulated film image flow data to identify and quantify the clinical endpoint flows and volumes that would have to be supported by PACS. The authors conclusions are listed

  6. 人类疱疹病毒6型荧光定量PCR检测方法的建立和应用%Establishment and clinical application of TapMan real-time RT-PCR method for detection of HHV-6

    Institute of Scientific and Technical Information of China (English)

    陈倩倩; 张兵; 谢志萍; 李金松; 高寒春; 肖霓光; 谢乐云; 余阗; 曾赛珍

    2013-01-01

    目的 建立人类疱疹病毒6型(HHV-6)荧光定量PCR检测方法,并检测临床样本.方法 根据文献合成HHV-6 U65-66基因片段的特异性引物和TaqMan探针,构建质粒制备标准品,评估该方法的特异性、灵敏度和重复性;并用该方法检测93份临床诊断为病毒性脑炎的脑脊液标本.结果 本实验检测HHV-6的灵敏度为3×10(0)拷贝/μl;标准曲线间线性关系(R2)为0.999,扩增效率为97.9%;同一样本重复检测3次,组内Ct值的变异系数最大为0.61%,组间为3.13%;特异性检测中只有HHV-6阳性标本出现扩增曲线.93份临床标本中检出HHV-6阳性2例,检出率为2.15%.结论 本实验所建立的荧光定量PCR检测HHV-6的方法特异强、灵敏高、重复性好,具有应用于临床检测的潜在价值.%Objective To establish a rapid,sensitive and specific real-time PCR method for detection of Human Herpesvirus-6 (HHV-6).Methods According to thc rcfcrcncc,a pair of primcrs and a probe were designed located in U65-66 gene and to set up the standards.We established a real-time RT-PCR method for detection of HHV-6,and to verify the specificity,sensitivity,reproducibility.Results The correlation coefficient was 0.999,E =97.9%,the coefficient of variation values of Ct were 0.61% and 3.13% in real-time PCR assay for inter and intra assay,respectively.The results of all viruses were negative except of HHV-6 for the assay.The quantitative detection limit of the assay was 3 × 10(0) copies/μl.Conclusion The real-time PCR assay is highly specific,sensitive and reproducible,which can be used to quatitative detecting clinical samples.

  7. Noninvasive measurement of cerebrospinal fluid flow using an ultrasonic transit time flow sensor: a preliminary study.

    Science.gov (United States)

    Pennell, Thomas; Yi, Juneyoung L; Kaufman, Bruce A; Krishnamurthy, Satish

    2016-03-01

    OBJECT Mechanical failure-which is the primary cause of CSF shunt malfunction-is not readily diagnosed, and the specific reasons for mechanical failure are not easily discerned. Prior attempts to measure CSF flow noninvasively have lacked the ability to either quantitatively or qualitatively obtain data. To address these needs, this preliminary study evaluates an ultrasonic transit time flow sensor in pediatric and adult patients with external ventricular drains (EVDs). One goal was to confirm the stated accuracy of the sensor in a clinical setting. A second goal was to observe the sensor's capability to record real-time continuous CSF flow. The final goal was to observe recordings during instances of flow blockage or lack of flow in order to determine the sensor's ability to identify these changes. METHODS A total of 5 pediatric and 11 adult patients who had received EVDs for the treatment of hydrocephalus were studied in a hospital setting. The primary EVD was connected to a secondary study EVD that contained a fluid-filled pressure transducer and an in-line transit time flow sensor. Comparisons were made between the weight of the drainage bag and the flow measured via the sensor in order to confirm its accuracy. Data from the pressure transducer and the flow sensor were recorded continuously at 100 Hz for a period of 24 hours by a data acquisition system, while the hourly CSF flow into the drip chamber was recorded manually. Changes in the patient's neurological status and their time points were noted. RESULTS The flow sensor demonstrated a proven accuracy of ± 15% or ± 2 ml/hr. The flow sensor allowed real-time continuous flow waveform data recordings. Dynamic analysis of CSF flow waveforms allowed the calculation of the pressure-volume index. Lastly, the sensor was able to diagnose a blocked catheter and distinguish between the blockage and lack of flow. CONCLUSIONS The Transonic flow sensor accurately measures CSF output within ± 15% or ± 2 ml

  8. Introduction to compressible fluid flow

    CERN Document Server

    Oosthuizen, Patrick H

    2013-01-01

    IntroductionThe Equations of Steady One-Dimensional Compressible FlowSome Fundamental Aspects of Compressible FlowOne-Dimensional Isentropic FlowNormal Shock WavesOblique Shock WavesExpansion Waves - Prandtl-Meyer FlowVariable Area FlowsAdiabatic Flow with FrictionFlow with Heat TransferLinearized Analysis of Two-Dimensional Compressible FlowsHypersonic and High-Temperature FlowsHigh-Temperature Gas EffectsLow-Density FlowsBibliographyAppendices

  9. Writing clinical scenarios for clinical science questions.

    Science.gov (United States)

    Smith, Phil Em; Mucklow, John C

    2016-04-01

    Written knowledge assessments for physicians in training typically involve multiple-choice questions that use a clinical scenario in a single-best-answer format. The Royal College of Physicians Part 1 MRCP(UK) examination includes basic sciences themes that are challenging to assess through a clinical scenario. A realistic clinical setting based on everyday clinical practice and integral to the question is the clearest demonstration that the knowledge being assessed is clinically relevant. However, without special attention to detail, the scenario in a clinical science question can appear redundant or artificial. Reading unnecessary material frustrates candidates and threatens the reputation of the assessment. In this paper we discuss why a clinical scenario is important for basic science questions and offer advice on setting realistic and plausible clinical scenarios for such questions. PMID:27037383

  10. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... this page please turn Javascript on. Participating in Clinical Trials About Clinical Trials A Research Study With Human Subjects A clinical ... to treat or cure a disease. Phases of Clinical Trials Clinical trials of drugs are usually described based ...

  11. Research Advances: DRPS--Let The Blood Flow!

    Science.gov (United States)

    King, Angela G.

    2007-01-01

    A team from the University of Pittsburgh's McGowan Institute for Regenerative Medicine has shown the potential for clinical use of the drag-reducing polymer (DRP) poly(N-vinylformamide), or PNVF. The high molecular weight PNVF is shown to reduce resistance to turbulent flow in a pipe and to enhance blood flow in animal models and it also…

  12. An Active, Collaborative Approach to Learning Skills in Flow Cytometry

    Science.gov (United States)

    Fuller, Kathryn; Linden, Matthew D.; Lee-Pullen, Tracey; Fragall, Clayton; Erber, Wendy N.; Röhrig, Kimberley J.

    2016-01-01

    Advances in science education research have the potential to improve the way students learn to perform scientific interpretations and understand science concepts. We developed active, collaborative activities to teach skills in manipulating flow cytometry data using FlowJo software. Undergraduate students were given compensated clinical flow…

  13. Asymmetric flow field-flow fractionation of (bio) macromolecules (abstract)

    International Nuclear Information System (INIS)

    Field-Flow Fractionation (FFF) has developed into a promising separation technique with different variants in various applications fields of separation sciences. Asymmetric Flow FFF (FlFFF) is the most popular class of the FFF family; it is used for the separation and characterization of nano- to micro-sized particles of diverse origin. It is simple, gentle and soft separation principle is most feasible for fragile macromolecules present in biological samples. Although recently there has been a substantial involvement of asymmetric FlFFF for the characterization of proteins, viruses, DNA and cells, its application for body fluid analysis in clinical laboratories has yet to be explored. The purpose of the research study was to explore asymmetric FlFFF as an analytical tool for the analysis of (bio) macromolecules, especially in clinical perspective and to see how much the results based on its use are beneficent in diagnostic studies of various diseases. Different approaches involving asymmetric FlFFF prior to renowned separating techniques such as liquid and gas chromatography are exploited, to get additional insights in (bio) macromolecules based on their size. The research work was focused on human serum analysis, to characterize lipoproteins and their associated compounds, which could add more information in diagnosing coronary heart diseases. Furthermore, the size-based separation of blood circulating hyaluronan was studied, which could provide a vital clue in understanding the metabolic activity of endothelial glyco calyx under pathological conditions. (author)

  14. Review of zonal flows

    International Nuclear Information System (INIS)

    A comprehensive review of zonal flow phenomena in plasmas is presented. While the emphasis is on zonal flows in laboratory plasmas, zonal flows in nature are discussed as well. The review presents the status of theory, numerical simulation and experiments relevant to zonal flows. The emphasis is on developing an integrated understanding of the dynamics of drift wave - zonal flow turbulence by combining detailed studies of the generation of zonal flows by drift waves, the back-interaction of zonal flows on the drift waves, and the various feedback loops by which the system regulates and organizes itself. The implications of zonal flow phenomena for confinement in, and the phenomena of fusion devices are discussed. Special attention is given to the comparison of experiment with theory and to identifying direction for progress in future research. (author)

  15. Peak flow meter (image)

    Science.gov (United States)

    A peak flow meter is commonly used by a person with asthma to measure the amount of air that can be ... become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow ...

  16. Urination - difficulty with flow

    Science.gov (United States)

    ... gov/ency/article/003143.htm Urination - difficulty with flow To use the sharing features on this page, ... at night? Has the force of your urine flow decreased? Do you have dribbling or leaking urine? ...

  17. Urination - difficulty with flow

    Science.gov (United States)

    ... at night? Has the force of your urine flow decreased? Do you have dribbling or leaking urine? ... conditions or surgeries that could affect your urine flow? What medicines do you take? Tests that may ...

  18. On Contact Anosov Flows

    OpenAIRE

    Carlangelo, Liverani

    2003-01-01

    Exponential decay of correlations for $\\Co^{(4)}$ Contact Anosov flows is established. This implies, in particular, exponential decay of correlations for all smooth geodesic flows in strictly negative curvature.

  19. Flowing holographic anyonic superfluid

    OpenAIRE

    Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew

    2014-01-01

    We investigate the flow of a strongly coupled anyonic superfluid based on the holographic D3-D7' probe brane model. By analyzing the spectrum of fluctuations, we find the critical superfluid velocity, as a function of the temperature, at which the flow stops being dissipationless when flowing past a barrier. We find that at a larger velocity the flow becomes unstable even in the absence of a barrier.

  20. Flow for Meta Control

    OpenAIRE

    Bulitko, Vadim

    2014-01-01

    The psychological state of flow has been linked to optimizing human performance. A key condition of flow emergence is a match between the human abilities and complexity of the task. We propose a simple computational model of flow for Artificial Intelligence (AI) agents. The model factors the standard agent-environment state into a self-reflective set of the agent's abilities and a socially learned set of the environmental complexity. Maximizing the flow serves as a meta control for the agent....

  1. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... Participating in Clinical Trials: About Clinical Trials In This Topic About Clinical Trials Risks and Benefits Terms ... with Your Doctor Taking Medicines The information in this topic was provided by the National Library of ...

  2. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... Clinical Trials In This Topic About Clinical Trials Risks and Benefits Terms to Know Finding a Clinical ... researchers may gather information about experimental treatments, their risks, and how well they work compare existing therapies ...

  3. Participating in Clinical Trials

    Medline Plus

    Full Text Available Home > Health topics A-Z > Participating in Clinical Trials: About Clinical Trials In This Topic About Clinical Trials Risks ... centers across the country. The National Institutes of Health funds much of this basic research. Screening Trials ...

  4. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... Participating in Clinical Trials About Clinical Trials A Research Study With Human Subjects A clinical trial is a research study that involves human subjects. The purpose of ...

  5. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... on. Participating in Clinical Trials About Clinical Trials A Research Study With Human Subjects A clinical trial is a research study that involves human subjects. The purpose ...

  6. STOCHASTIC FLOWS OF MAPPINGS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the stochastic flow of mappings generated by a Feller convolution semigroup on a compact metric space is studied. This kind of flow is the generalization of superprocesses of stochastic flows and stochastic diffeomorphism induced by the strong solutions of stochastic differential equations.

  7. Geodesic Renormalisation Group Flow

    OpenAIRE

    Dolan, Brian P

    1995-01-01

    It is shown that the renormalisation group flow in coupling constant space can be interpreted in terms of a dynamical equation for the couplings analogous to viscous fluid flow under the action of a potential. For free scalar field theory the flow is geodesic in two dimensions, while for $D \

  8. OpenFlow cookbook

    CERN Document Server

    Smiler S, Kingston

    2015-01-01

    This book is intended for network protocol developers, SDN controller application developers, and academics who would like to understand and develop their own OpenFlow switch or OpenFlow controller in any programming language. With basic understanding of OpenFlow and its components, you will be able to follow the recipes in this book.

  9. Exploring Clinical Overview

    DEFF Research Database (Denmark)

    Fleron, Benedicte

    Clinical overview is explored at four emergency departments (EDs) during the introduction of a new IT system to support hereof. Important aspects of clinical overview are described for the clinical practice and for the further development of the IT system.......Clinical overview is explored at four emergency departments (EDs) during the introduction of a new IT system to support hereof. Important aspects of clinical overview are described for the clinical practice and for the further development of the IT system....

  10. Future requirements. Clinical investigations

    DEFF Research Database (Denmark)

    Qvist, V.

    2002-01-01

    Biocompatability, Cariology, Clinical trials, Dental materials, Helath services research, Human, Pedodontics......Biocompatability, Cariology, Clinical trials, Dental materials, Helath services research, Human, Pedodontics...

  11. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

  12. Physics of zonal flows

    International Nuclear Information System (INIS)

    Zonal flows, which means azimuthally symmetric band-like shear flows, are ubiquitous phenomena in nature and the laboratory. It is now widely recognized that zonal flows are a key constituent in virtually all cases and regimes of drift wave turbulence, indeed, so much so that this classic problem is now frequently referred to as ''drift wave-zonal flow turbulence.'' In this review, new viewpoints and unifying concepts are presented, which facilitate understanding of zonal flow physics, via theory, computation and their confrontation with the results of laboratory experiment. Special emphasis is placed on identifying avenues for further progress. (author)

  13. Lateral flow strip assay

    Science.gov (United States)

    Miles, Robin R.; Benett, William J.; Coleman, Matthew A.; Pearson, Francesca S.; Nasarabadi, Shanavaz L.

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  14. Signal flow analysis

    CERN Document Server

    Abrahams, J R; Hiller, N

    1965-01-01

    Signal Flow Analysis provides information pertinent to the fundamental aspects of signal flow analysis. This book discusses the basic theory of signal flow graphs and shows their relation to the usual algebraic equations.Organized into seven chapters, this book begins with an overview of properties of a flow graph. This text then demonstrates how flow graphs can be applied to a wide range of electrical circuits that do not involve amplification. Other chapters deal with the parameters as well as circuit applications of transistors. This book discusses as well the variety of circuits using ther

  15. Granular media: flow & agitations

    OpenAIRE

    Dijksman, Joshua Albert

    2009-01-01

    This thesis is about weakly driven granular flows and suspensions. Chapter 1 is an overview of the current knowledge of slow granular flows in so-called split-bottom geometries, which in essence consist of a disk rotating at the bottom of a container. In chapter 2 we study dry granular flows in this split-bottom geometry, both in the frictional, slow, rate-independent regime, and in the liquid-like, rate dependent regime which is reached for faster flows. Chapters 3-5 deal with the flow of su...

  16. Annular Flow Distribution test

    International Nuclear Information System (INIS)

    This report documents the Babcock and Wilcox (B ampersand W) Annular Flow Distribution testing for the Savannah River Laboratory (SRL). The objective of the Annular Flow Distribution Test Program is to characterize the flow distribution between annular coolant channels for the Mark-22 fuel assembly with the bottom fitting insert (BFI) in place. Flow rate measurements for each annular channel were obtained by establishing ''hydraulic similarity'' between an instrumented fuel assembly with the BFI removed and a ''reference'' fuel assembly with the BFI installed. Empirical correlations of annular flow rates were generated for a range of boundary conditions

  17. [AGIKO (Clinical Research Fellow); a training model aimed at enhancement of clinical scientific research].

    Science.gov (United States)

    van Rees-Wortelboer, M M; Lamberts, S W; Klasen, E C

    1997-06-21

    The enhancement of clinical scientific research in the Netherlands is being stimulated to a substantial extent by the introduction and stimulation of a training model aimed at the combined training of physicians to both a general practitioner or specialist and a clinical researcher, the AGIKO (Clinical Research Fellow). The model has been recognized by the Central College for Recognition and Registration of Medical Specialists. Extra stimulation by the section Medical Sciences of the Netherlands Organization for Scientific Research (MW-NWO) makes it possible to appoint AGIKOs on second or third flows of funds but also within the first flow of funds. During the last two years, 25 AGIKO applications from ten medical specialisms have been approved. The AGIKO model may help to meet (expected) needs for future clinical-medical research workers in specific research areas. PMID:9380169

  18. Advanced flow MRI: emerging techniques and applications.

    Science.gov (United States)

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented. PMID:26944696

  19. In vitro validation of volumetric blood flow measurement using Doppler flow wire.

    Science.gov (United States)

    Jenni, R; Kaufmann, P A; Jiang, Z; Attenhofer, C; Linka, A; Mandinov, L

    2000-10-01

    Determination of any volumetric blood flow requires assessment of mean blood flow velocity and vessel cross-sectional area. For evaluation of coronary blood flow and flow reserve, however, assessment of average peak velocity alone is widely used, but changes in velocity profile and vessel area are not taken into account. We studied the feasibility of a new method for calculation of volumetric blood flow by Doppler power using a Doppler flow wire. An in vitro model with serially connected silicone tubes of known lumen diameters (1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mm) and pulsatile blood flow ranging from 10 to 200 mL/min was used. A Doppler flow wire was connected to a commercially available Doppler system (FloMap(R), Cardiometrics) for online calculation of the zeroth (M(0)) and the first (M(1)) Doppler moment, as well as mean flow velocity (V(m)). Two different groups of sample volumes (at different gate depths) were used: 1. two proximal sample volumes lying completely within the vessel were required to evaluate the effect of scattering and attenuation on Doppler power, and 2. distal sample volumes intersecting completely the vessel lumen to assess the vessel cross-sectional area. Area (using M(0)) and V(m) (using M(1)/M(0)) obtained from the distal gates were corrected for scattering and attenuation by the data obtained from the proximal gates, allowing calculation of absolute volumetric flow. These results were compared to the respective time collected flow. Correlation between time collected and Doppler-derived flow measurements was 0.98 (p measurements in each individual tube. The mean paired flow difference between the two techniques was 1.5 +/- 9.0 mL/min (ns). Direct volumetric blood flow measurement from received Doppler power using a Doppler flow wire system is feasible. This technique may potentially be of great clinical value because it allows an accurate assessment of coronary flow and flow reserve with a commercially available flow wire system. PMID

  20. Children and Clinical Studies: Why Clinical Studies Are Important

    Medline Plus

    Full Text Available ... Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & Clinical Studies NHLBI Trials Clinical Trial Websites ...

  1. Clinical Trials in Vision Research

    Science.gov (United States)

    ... Eye Health Information > Clinical Trials in Vision Research Clinical Trials in Vision Research Listen Clinical studies depend on ... vision research in the United States. Basics of Clinical Trials What is a clinical trial? Clinical trials are ...

  2. Good clinical practice in clinical interventional studies

    OpenAIRE

    Pieterse, Herman; Diamant, Zuzana

    2014-01-01

    Good clinical practice (GCP) guidelines should always be implemented and obeyed in clinical interventional studies. In this mini-review, we will address several burning questions relating to GCP in a concise ‘frequently asked questions’ format.While compliance to current rules and regulations is our mission, we also wish to play devil’s advocate attempting to translate the rules into sizeable chunks using a high dose of common sense.Keywords: clinical interventional studies; quality; safety; ...

  3. PIV Investigations on Secondary Flow Structures in Horizontal Slug Flows

    OpenAIRE

    Aguas Fernández, Pedro José

    2011-01-01

    Liquid and gas phases circulate horizontally through the same channel in many industrial processes. They can do it following different patterns of so-called two-phase flow. Depending on the superficial velocity of each one of the phases, the flow can vary. The different types of flows observed in horizontal pipes are bubbly flow, stratified flow,wavy flow, slug flowand annular flow. The first formal classification of flow patterns was carried out by Taitel and Dukler during the...

  4. Thread-annular flow in vertical pipes

    Science.gov (United States)

    Frei, Ch.; Lüscher, P.; Wintermantel, E.

    2000-05-01

    Thread injection is a promising method for different minimally invasive medical applications. This paper documents an experimental study dealing with an axially moving thread in annular pipe flow. Mass flow and axial force on the thread are measured for a 0.46 mm diameter thread in pipes with diameters between 0.55 and 1.35 mm. The experiments with thread velocities of up to 1.5 ms[minus sign]1 confirm the findings of theoretical studies that for clinical requirements the radius ratio between thread and pipe is crucial for the adjustments of mass ow and force on the thread.

  5. 46 CFR 154.546 - Excess flow valve: Closing flow.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Excess flow valve: Closing flow. 154.546 Section 154.546... and Process Piping Systems § 154.546 Excess flow valve: Closing flow. (a) The rated closing flow of vapor or liquid cargo for an excess flow valve must be specially approved by the Commandant (CG-522)....

  6. 体外反搏治疗对失眠患者脑血流变化情况的临床研究%The Clinical Research of Effect of External Counterpulsation Therapy on Cerebral Blood Flow of Patients with Insomnia

    Institute of Scientific and Technical Information of China (English)

    沈跃玲; 蔡亚梅; 邓耀波; 孙玉华

    2012-01-01

    can improve the sleep quality an clinical symptoms of patients with insomnia, but the formal treatment has better effect. The mechanism of external counterpulsation for the treatment of insomnia is related with improving the cerebral blood flow of patients.

  7. 益气活血解毒法对溃疡性结肠炎血浆血小板活化的临床及实验研究%Clinical study and animal experiment on benefiting vital Qi, activating blood flow and detoxication on plasma platelet activation during ulcerative colitis

    Institute of Scientific and Technical Information of China (English)

    安贺军; 王新月; 于玫; 沈静

    2011-01-01

    [目的]探讨益气活血解毒法对溃疡性结肠炎(UC)血浆血小板活化的影响.[方法]分临床研究及动物实验两部分;临床研究以90例溃疡性结肠炎复发患者按随机数字表法随机分为2组,中药治疗组45例,西药对照组45例.治疗3个月后对完全缓解及有效病例(其中治疗组39例,对照组32例)进行为期6个月的随访.治疗组给予益气活血解毒立法的中药汤剂.对照组给予柳氮磺胺吡啶治疗,并各与20例作正常对照.动物实验用三硝基苯磺酸(TNBS)复制实验性大鼠UC模型,将其随机分为模型组、西药对照组、中药治疗组,并设正常对照组.进行反映血小板活化程度的特异性标志物P-选择素的检测.[结果]临床研究中,治疗前UC患者血浆P-选择素水平明显高于正常健康人(P0.05);停药10d时,中药组明显低于西药组(P<0.05).[结论]以益气活血解毒立法的中药溃结复发方与西药比较,可有效降低血浆P-选择素水平,从而阻抑血小板活化,可能是抗溃结复发作用机制之一.%[Objective]To investigate the influence of benefiting vital QI activating blood flow and detoxication on plasma platelet activation during ulcerative colitis (UC).[Methods]The study included clinical study and animal experiment.In clinical study, 90 cases with recurrent UC were randomly divided into the treatment group (n=45) and the control group (n=45) according to the random table.Three months after treatment, the cases of complete remission and effective cases were followed-up for 6 months (39 cases in treatment group, 32 in control group).The patients of treatment group received medicinal decoction of TCM consisting of herbs with benefiting vital Qi, activating blood flow and detoxication; the control group was treated with salazosulfapyridine.In animal experiment, UC was induced with TNBS in rats and then randomly divided into model control group, western medicine group, the traditional Chinese medicine

  8. 导流杂交检测人乳头状瘤病毒感染与宫颈癌临床分期及病理分型关系%Flow-through hybridization detection of the relationship between HPV infection and cervical cancer clinical staging and pathology typing

    Institute of Scientific and Technical Information of China (English)

    陈文学; 张焜和; 邹学森; 黄秀珍; 陈岳青

    2014-01-01

    目的:分析导流杂交检测人乳头状瘤病毒(H PV )感染与宫颈癌临床分期及病理分型的关系,为其筛查和诊断提供依据。方法使用导流杂交技术对医院2009年3月-2012年7月收治的2176例门诊或住院女性患者,进行HPV检测,对 HPV阳性患者进行宫颈组织病理学诊断,分析导流杂交检测结果与病理学诊断结果的关系,所有数据采用SPSS13.0软件进行统计分析。结果2176例患者中共检出1283例 HPV 阳性,阳性率58.96%,其中1145例细胞学异常,异常率52.61%,细胞学正常患者H PV阳性率明显低于慢性炎症、宫颈上皮内瘤病变(CIN)及宫颈癌患者,差异有统计学意义(P<0.05);宫颈癌患者 HPV阳性率为100.0%,显著高于慢性炎症及CIN患者;1283例HPV阳性患者病理诊断高危率为40.45%,细胞学正常、慢性炎症及CINⅠ患者高危率明显低于CINⅡ、Ⅲ及宫颈癌患者,差异有统计学意义(P<0.05)。结论 HPV感染是导致宫颈癌发生发展的重要因素,HPV阳性率高、高危分型率高,提示患者宫颈癌风险越高,而宫颈癌导流杂交检测具有操作方便、结果直观、判断准确等优势,可有效提高宫颈癌癌前病变的检测效果。%OBJECTIVE To analyze the releationship between HPV infection and cervical cancer clinical staging and pathology typing by using flow-through hybridization detection ,so as to provide the basis for the screening and diagnosis of typing and staging and clinical pathology of cervical cancer . METHODS Using flow-through hybridization technique in our hospital in Mar .2009 to Jul .2012 ,a total of 2176 cases of female outpatients or hospitalization in female patients with HPV were detected in HPV positive patients ,cervical histopathological diagnosis ,analysis of the relationship between the detection results of flow-through hybridization and pathology diagnosis results .SPSS16 .0

  9. Flows of Reactive Fluids

    CERN Document Server

    Prud'homme, Roger

    2010-01-01

    The modeling of reactive flows has progressed mainly with advances in aerospace, which gave birth to a new science called aerothermochemistry, as well as through developments in chemical and process engineering. The methods employed, the phenomena investigated, and the aims of modeling differ for each field; however, in all cases, the results obtained have considerably enriched the working knowledge of reactive flows. This work examines basic concepts and methods necessary to study reactive flows and transfer phenomena in areas such as fluid mechanics, thermodynamics, and chemistry. Specific topics covered include: * Equations of state * Transfer phenomena and chemical kinetics * Balance equations of reactive flows * Dimensionless numbers and similarity * Chemical reactors * Coupled phenomena * Turbulent flow concepts * Boundary layers and fluid layers * Reactive and nonreactive waves * Interface phenomena * Multiphase flow concepts The book presents tools of interest to graduate students, researchers in math...

  10. Mitral and aortic valvular flow: quantification with MR phase mapping

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Thomsen, C; Ståhlberg, F;

    1992-01-01

    When magnetic resonance phase mapping is used to quantitate valvular blood flow, the presence of higher-order-motion terms may cause a loss of phase information. To overcome this problem, a sequence with reduced encoding for higher-order motion was used, achieved by decreasing the duration of the...... flow-encoding gradient to 2.2 msec. Tested on a flow phantom simulating a severe valvular stenosis, the sequence was found to be robust for higher-order motion within the clinical velocity range. In eight healthy volunteers, mitral and aortic volume flow rates and peak velocities were quantified by...

  11. Quantitative myocardial blood flow with Rubidium-82 PET

    DEFF Research Database (Denmark)

    Hagemann, Christoffer E; Ghotbi, Adam A; Kjær, Andreas; Hasbak, Philip

    2015-01-01

    Positron emission tomography (PET) allows assessment of myocardial blood flow in absolute terms (ml/min/g). Quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) extend the scope of conventional semi-quantitative myocardial perfusion imaging (MPI): e.g. in 1...... diagnose and risk stratify CAD patients, while assessing the potential of the modality in clinical practice.......) identification of the extent of a multivessel coronary artery disease (CAD) burden, 2) patients with balanced 3-vessel CAD, 3) patients with subclinical CAD, and 4) patients with regional flow variance, despite of a high global MFR. A more accurate assessment of the ischemic burden in patients with intermediate...

  12. Clinical Trial Results: A Clinical Trial Bazaar!

    OpenAIRE

    Fojo, Antonio Tito; Bates, Susan E.

    2014-01-01

    The Oncologist’s Clinical Trial Results section welcomes both positive and negative results in an effort to share information, speed discovery, and inform the field. Clinical Trial Results submissions have shown how succinctly the salient features of a submission can be presented, with more in-depth information to be found online.

  13. Optimizing Traffic Flow

    OpenAIRE

    Huberman, Bernardo A.; Helbing, Dirk

    1998-01-01

    We present an economics-based method for deciding the optimal rates at which vehicles are allowed to enter a highway. The method exploits the naturally occuring fluctuations of traffic flow and is flexible enough to adapt in real time to the transient flow characteristics of road traffic. Simulations based on realistic parameter values show that this strategy is feasible for naturally occuring traffic, and that even far from optimality, injection policies can improve traffic flow. Our results...

  14. TRANSIMS traffic flow characteristics

    OpenAIRE

    Nagel, Kai; Stretz, Paula; Pieck, Martin; Donnelly, Rick; Barrett, Christopher L.

    1997-01-01

    Knowledge of fundamental traffic flow characteristics of traffic simulation models is an essential requirement when using these models for the planning, design, and operation of transportation systems. In this paper we discuss the following: a description of how features relevant to traffic flow are currently under implementation in the TRANSIMS microsimulation, a proposition for standardized traffic flow tests for traffic simulation models, and the results of these tests for two different ve...

  15. Polyoxometalate flow battery

    Science.gov (United States)

    Anderson, Travis M.; Pratt, Harry D.

    2016-03-15

    Flow batteries including an electrolyte of a polyoxometalate material are disclosed herein. In a general embodiment, the flow battery includes an electrochemical cell including an anode portion, a cathode portion and a separator disposed between the anode portion and the cathode portion. Each of the anode portion and the cathode portion comprises a polyoxometalate material. The flow battery further includes an anode electrode disposed in the anode portion and a cathode electrode disposed in the cathode portion.

  16. Intelligent Multiphase Flow Measurement

    OpenAIRE

    Ibrahim, Abba A.

    2009-01-01

    The oil and gas industry’s goal of developing high performing multiphase flow metering systems capable of reducing costs in the exploitation of marginal oil and gas reserves, especially in remote environments, cannot be over emphasised. Development of a cost-effective multiphase flow meter to determine the individual phase flow rates of oil, water and gas was experimentally investigated by means of low cost, simple and non-intrusive commercially available sensors. Features from...

  17. Defining Quantum Control Flow

    OpenAIRE

    Ying, Mingsheng; Yu, Nengkun; Feng, Yuan

    2012-01-01

    A remarkable difference between quantum and classical programs is that the control flow of the former can be either classical or quantum. One of the key issues in the theory of quantum programming languages is defining and understanding quantum control flow. A functional language with quantum control flow was defined by Altenkirch and Grattage [\\textit{Proc. LICS'05}, pp. 249-258]. This paper extends their work, and we introduce a general quantum control structure by defining three new quantu...

  18. FLOW FORMING OF AEROENGINEMATERIALS

    OpenAIRE

    Kubilay, Ceylan

    2014-01-01

    Flow forming is a fairly new technique used for the production of dimensionallyaccurate near net shaped hollow components. The process has many advantagessuch as cost effectiveness and eliminating further operations like welding, machin-ing, etc. This study focuses on the characterization of flow formed componentsto understand the process. Flow formed components are composed of differentreductions and characterization techniques are applied to reveal the resulting mi-crostructural differences...

  19. Grammar flow analysis

    OpenAIRE

    Möncke, Ulrich R.

    1986-01-01

    This paper specifies the theoretical basis for the implementation of different generators of the OPTRAN system. Grammar Flow analysis transports the techniques of data flow analysis to the meta level of compiler construction. The analogon to the states in data flow analysis are the syntax trees together with some information, which is associated with trees by propagation functions. One example is the association of characteristic graphs, another example the association of sets of matching tre...

  20. Turbulent flow in graphene

    OpenAIRE

    Gupta, Kumar S.; Sen, Siddhartha

    2009-01-01

    We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

  1. Traffic Flow Management System

    Data.gov (United States)

    Department of Transportation — TFMS is a set NAS operational tools that predict demand, identify constraints, and facilitates collaboration among NAS users to support efficient traffic flow while...

  2. The other spectral flow

    CERN Document Server

    Gato-Rivera, Beatriz; Gato-Rivera, Beatriz; Rosado, Jose Ignacio

    1995-01-01

    Recently we showed that the spectral flow acting on the N=2 twisted topological theories gives rise to a topological algebra automorphism. Here we point out that the untwisting of that automorphism leads to a spectral flow on the untwisted N=2 superconformal algebra which is different from the usual one. This "other" spectral flow does not interpolate between the chiral ring and the antichiral ring. In particular, it maps the chiral ring into the chiral ring and the antichiral ring into the antichiral ring. We discuss the similarities and differences between both spectral flows. We also analyze their action on null states.

  3. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system is...... implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V with a...

  4. Children and Clinical Studies: Why Clinical Studies Are Important

    Medline Plus

    Full Text Available ... Children & Clinical Studies NHLBI Trials Clinical Trial Websites Children and Clinical Studies Learn more about Children and Clinical Studies Importance of Children in Clinical Studies Children have often had to ...

  5. Flow rate measuring devices for gas flows

    Science.gov (United States)

    Bonfig, K. W.

    1985-07-01

    Flowrate measuring devices are described: volume meter with fixed or mobile walls; turbine meter; throttling procedure; ultrasonic and Doppler methods; vortex method; rotary flowmeter; and swinging body flow measuring procedure. Flowrate can also be measured from the force exerted on bodies immersed in a fluid or based on thermodynamical principles. The characteristics and operating envelope of each device/method are given.

  6. [Clinical cytology: why and how?].

    Science.gov (United States)

    Znidarcić, Zeljka

    2013-12-01

    Clinical cytology is a morphological diagnostic profession, which has not been properly utilized in current medicine, primarily due to inadequate awareness among physicians of its diagnostic possibilities and advantages. The purpose of this historical review of clinical cytology and its diagnostic role is to contribute to higher awareness of the current possibilities offered by cytologic diagnosis and its future development in the era of technological progress and medical striking into profitability, with its negative connotations. The main features of cytologic diagnosis, i.e. non-aggressiveness, simplicity, promptness and accuracy, should be maintained while following new technological possibilities. Standard cytomorphology provides a basis for deciding on using additional technologies (cytochemistry, immunocytochemistry, flow cytometry, molecular analysis and cytogenetics) after thorough microscopic analysis, on cytologic samples or/and cytologic smears. The conditio sine qua non for that purpose is appropriate education of cytologists and cytotechnologists as well as appropriate organization of cytology in the healthcare system. As in the historical development of clinical cytology, enthusiasts are necessary to maintain and even improve all its possibilities to the benefit of our patients. PMID:24979879

  7. 3D vector flow imaging

    DEFF Research Database (Denmark)

    Pihl, Michael Johannes

    The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... on the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based on 5...

  8. flowCL: ontology-based cell population labelling in flow cytometry

    Science.gov (United States)

    Courtot, Mélanie; Meskas, Justin; Diehl, Alexander D.; Droumeva, Radina; Gottardo, Raphael; Jalali, Adrin; Taghiyar, Mohammad Jafar; Maecker, Holden T.; McCoy, J. Philip; Ruttenberg, Alan; Scheuermann, Richard H.; Brinkman, Ryan R.

    2015-01-01

    Motivation: Finding one or more cell populations of interest, such as those correlating to a specific disease, is critical when analysing flow cytometry data. However, labelling of cell populations is not well defined, making it difficult to integrate the output of algorithms to external knowledge sources. Results: We developed flowCL, a software package that performs semantic labelling of cell populations based on their surface markers and applied it to labelling of the Federation of Clinical Immunology Societies Human Immunology Project Consortium lyoplate populations as a use case. Conclusion: By providing automated labelling of cell populations based on their immunophenotype, flowCL allows for unambiguous and reproducible identification of standardized cell types. Availability and implementation: Code, R script and documentation are available under the Artistic 2.0 license through Bioconductor (http://www.bioconductor.org/packages/devel/bioc/html/flowCL.html). Contact: rbrinkman@bccrc.ca Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25481008

  9. RG Flows and Bifurcations

    CERN Document Server

    Gukov, Sergei

    2016-01-01

    Interpreting RG flows as dynamical systems in the space of couplings we produce a variety of constraints, global (topological) as well as local. These constraints, in turn, rule out some of the proposed RG flows and also predict new phases and fixed points, surprisingly, even in familiar theories such as O(N) model, QED-3, or QCD-4.

  10. Traffic Flow Estimates.

    Science.gov (United States)

    Hart, Vincent G.

    1981-01-01

    Two examples are given of ways traffic engineers estimate traffic flow. The first, Floating Car Method, involves some basic ideas and the notion of relative velocity. The second, Maximum Traffic Flow, is viewed to involve simple applications of calculus. The material provides insight into specialized applications of mathematics. (MP)

  11. Gauge invariant flow equation

    CERN Document Server

    Wetterich, C

    2016-01-01

    We propose a gauge invariant flow equation for Yang-Mills theories and quantum gravity that only involves one macroscopic gauge field or metric. It is based on a projection on physical and gauge fluctuations, corresponding to a particular gauge fixing. The freedom in the precise choice of the macroscopic field can be exploited in order to keep the flow equation simple.

  12. Organocatalysis in continuous flow

    NARCIS (Netherlands)

    Berg, van den S.A.

    2016-01-01

    Continuous flow chemistry is an enabling technique in organic chemistry. Advantages include extremely fast mixing and heat transfer capabilities as well as rapid screening of reaction conditions. Combining continuous flow chemistry with solid-supported organocatalysis presents challenges that have b

  13. Flow og anerkendelse

    DEFF Research Database (Denmark)

    Kristensen, René

    2006-01-01

    Artiklen handler om pædagogisk perspektivering af flow i forhold til anerkendelse og kreativitet. Procedural hukommelsesdannelse inddrages i forbindelse med flowforståelsen......Artiklen handler om pædagogisk perspektivering af flow i forhold til anerkendelse og kreativitet. Procedural hukommelsesdannelse inddrages i forbindelse med flowforståelsen...

  14. Flow i hverdagen

    DEFF Research Database (Denmark)

    Andersen, Frans Ørsted; Hanssen, Nina

    Bogen afspejler et eksplorativt dansk-norsk forskningsprojekt med fokus på hverdagslivets psykiske sider, herunder størrelser som stress og flow.......Bogen afspejler et eksplorativt dansk-norsk forskningsprojekt med fokus på hverdagslivets psykiske sider, herunder størrelser som stress og flow....

  15. Microelectromechanical flow control apparatus

    Science.gov (United States)

    Okandan, Murat

    2009-06-02

    A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.

  16. Braneworld flow equations

    OpenAIRE

    Ramirez, Erandy; Liddle, Andrew

    2004-01-01

    We generalize the flow equations approach to inflationary model building to the Randall–Sundrum Type II braneworld scenario. As the flow equations are quite insensitive to the expansion dynamics, we find results similar to, though not identical to, those found in the standard cosmology.

  17. Field-Flow Fractionation.

    Science.gov (United States)

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  18. Hanford basalt flow mineralogy

    International Nuclear Information System (INIS)

    Mineralogy of the core samples from five core wells was examined in some detail. The primary mineralogy study included an optical examination of polished mounts, photomicrographs, chemical analyses of feldspars, pyroxenes, metallic oxides and microcrystalline groundmasses and determination from the chemical analyses of the varieties of feldspars, pyroxenes and metallic oxides. From the primary mineralogy data, a firm understanding of the average Hanford basalt flow primary mineralogy emerged. The average primary feldspar was a laboradorite, the average pyroxene was an augite and the average metallic oxide was a solid solution of ilmenite and magnetite. Secondary mineralization consisted of vug filling and joint coating, chiefly with a nontronite-beidellite clay, several zeolites, quartz, calcite, and opal. Specific flow units also were examined to determine the possibility of using the mineralogy to trace flows between core wells. These included units of the Pomona, the Umatilla and a high chromium flow just below the Huntzinger. In the Umatilla, or high barium flow, the compositional variation of the feldspars was unique in range. The pyroxenes in the Pomona were relatively highly zoned and accumulated chromium. The high chromium flow contained chromium spinels that graded in chromium content into simple magnetites very low in chromium content. A study of the statistical relationships of flow unit chemical constituents showed that flow unit constituents could be roughly correlated between wells. The probable cause of the correlation was on-going physical-chemical changes in the source magma

  19. Quantitative phase-flow MR imaging in dogs by using standard sequences: comparison with in vivo flow-meter measurements.

    Science.gov (United States)

    Pettigrew, R I; Dannels, W; Galloway, J R; Pearson, T; Millikan, W; Henderson, J M; Peterson, J; Bernardino, M E

    1987-02-01

    For evaluation of the feasibility and clinical potential of using the phase data from standard MR imaging sequences to measure blood flow, 11 vessels with diameters of 4 to 7 mm were imaged in seven dogs. The flow in either the superior mesenteric vein or the inferior vena cava was measured first at laparotomy (in ml/min) with electromagnetic flow meters. Immediately thereafter, these vessels were imaged by MR in 25-mm thick sections by using a standard spin echo (SE) 750/30 sequence with a Philips 0.5-T imager. Previous phase-flow calibration of the imager and sequence allowed calculation of the blood flow rates from the phase images that were used to measure the vessels' cross-sectional areas and blood phase values. Comparison of the measurements obtained with each technique showed a significant correlation (r = .977, p less than .05) between MR-imaging values and flow-meter measurements when the blood velocity was less than approximately 40 cm/sec, the known upper limit of the flow dynamic range for the MR hardware and sequence used. There was no correlation for blood velocities greater than 40 cm/sec. However, the range of blood flow velocities in dogs and man extends to more than 100 cm/sec. Thus, these results suggest that this technique might yield valuable adjunctive flow data in routine clinical imaging provided that improvements in hardware and software permit a larger dynamic range. PMID:2948376

  20. Colour doppler flow imaging of focal hepatic lesions

    International Nuclear Information System (INIS)

    Fifty-four patients with focal liver lesions were evaluated with colour Doppler flow imaging (CDFI) and CT to assess whether CDFI could be used to differentiate various types of lesions based on the flow pattern in terms of peritumoral and intratumoral blood flow. Peritumoral flow was found to be of no significance in the differential diagnosis of various liver lesions. Intratumoral flow was graded into mild, moderate or marked depending on the relative number of blood vessels demonstrated within the lesion. Marked intratumoral flow on CDFI was seen in 12.5% of primary hepatic malignancies and in infantile haemangioendothelioma, while a moderate flow pattern was seen in 56.2% of primary hepatic malignancies and in 18.7% of metastases. Mild flow was seen in 33.3% of primary malignancies; 18.7% of metastases; and 16.7% of haemangiomas. No intratumoral flow was seen in 100% of inflammatory lesions; 83.3% of haemangiomas; 62.5% of metastases; and only one hepatocellular carcinoma (5.6%). It was therefore concluded that the presence or absence of flow on CDFI is not a reliable feature for differential diagnosis of focal liver lesions when it is used alone. The flow pattern as assessed on CDFI may point to the nature of the lesion and, when used along with other morphological imaging features, can assist in diagnosis or in narrowing the list of different diagnoses in a particular clinical situation. Copyright (2000) Blackwell Science Pty Ltd

  1. Vega flow assurance system

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Marit; Munaweera, Sampath

    2010-07-01

    Vega is a gas condensate field located at the west coast of Norway and developed as a tie-in to the Gjoea platform. Operator is Statoil, production startup is estimated to the end of 2010. Flow assurance challenges are high reservoir pressure and temperature, hydrate and wax control, liquid accumulation and monitoring the well/template production rates. The Vega Flow Assurance System (FAS) is a software that supports monitoring and operation of the field. The FAS is based FlowManagerTM designed for real time systems. This is a flexible tool with its own steady state multiphase- and flow assurance models. Due to the long flowlines lines and the dynamic behavior, the multiphase flow simulator OLGA is also integrated in the system. Vega FAS will be used as: - An online monitoring tool - An offline what-if simulation and validation tool - An advisory control system for well production allocation. (Author)

  2. Telescope enclosure flow visualization

    Science.gov (United States)

    Forbes, Fred F.; Wong, Woon-Yin; Baldwin, Jack; Siegmund, Walter A.; Limmongkol, Siriluk; Comfort, Charles H.

    1991-12-01

    Dome-induced thermal disturbances that degrade seeing can originate when temperature differences exist between the interior and exterior of a telescope enclosure. It is important to design enclosures which minimize the effect. One design aid is to model the enclosure and study the flow patterns in and around the model at various angles to the flow direction. We have used a water tunnel and models of spherical, octagonal, and rectangular enclosures to investigate the flow characteristics as a function of angle and venting configuration. In addition to a large video data-base, numerical results yield flushing times for all models and all venting arrangements. We have also investigated the comparative merits of passive venting as opposed to active forced flow circulation for the 4m telescope enclosure at the NOAO Cerro Tololo Interamerican Observatory at La Serena, Chile. Finally, the flow characteristics of a tracking half-shroud were studied as a possible shield for the enclosureless case.

  3. Turbulent multiphase flows

    Science.gov (United States)

    Faeth, G. M.

    1989-01-01

    Measurements and predictions of the structure of several multiphase flows are considered. The properties of dense sprays near the exits of pressure-atomizing injectors and of noncombusting and combusting dilute dispersed flows in round-jet configurations are addressed. It is found that the properties of dense sprays exhibit structure and mixing properties similar to variable-density single-phase flows at high Reynolds numbers within the atomization regime. The degree of development and turbulence levels at the injector exit have a surprisingly large effect on the structure and mixing properties of pressure-atomized sprays, particularly when the phase densities are large. Contemporary stochastic analysis of dilute multiphase flows provides encouraging predictions of turbulent dispersion for a wide variety of jetlike flows, particle-laden jets in gases and liquids, noncondensing and condensing bubbly jets, and nonevaporating, evaporating, and combusting sprays.

  4. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... Trials About Clinical Trials A Research Study With Human Subjects A clinical trial is a research study ... lifestyle changes, such as exercising more, getting more sleep, keeping mentally active, or eating nutritious foods, can ...

  5. Clinical Laboratory Fee Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — Outpatient clinical laboratory services are paid based on a fee schedule in accordance with Section 1833(h) of the Social Security Act. The clinical laboratory fee...

  6. NIH Clinical Centers

    Data.gov (United States)

    Federal Laboratory Consortium — The NIH Clinical Center consists of two main facilities: The Mark O. Hatfield Clinical Research Center, which opened in 2005, houses inpatient units, day hospitals,...

  7. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... trial is to find out if an experimental drug, therapy, medical device, lifestyle change, or test will ... disease. Phases of Clinical Trials Clinical trials of drugs are usually described based on their phase. The ...

  8. HISTIOCYTOSIS X: CLINICAL OBSERVATIONS

    Directory of Open Access Journals (Sweden)

    E. Y. Ponomareva

    2014-07-01

    Full Text Available Two clinical cases of pulmonary Langerhans cell histiocytosis X have been analyzed demonstrating lung and other inner organ pathology, common clinical and X-ray features but different life prognosis.

  9. HISTIOCYTOSIS X: CLINICAL OBSERVATIONS

    OpenAIRE

    E. Y. Ponomareva; A. P. Rebrov; E. E. Archangelskaja; A. A. Roshchina; R. N. Steshenko; A. S. Bukia; N. V. Dvornikova; N. N. Moskaleva

    2014-01-01

    Two clinical cases of pulmonary Langerhans cell histiocytosis X have been analyzed demonstrating lung and other inner organ pathology, common clinical and X-ray features but different life prognosis.

  10. Research Areas - Clinical Trials

    Science.gov (United States)

    Information about NCI programs and initiatives that sponsor, conduct, develop, or support clinical trials, including NCI’s Clinical Trial Network (NCTN) and NCI Community Oncology Research Program (NCORP) initiatives.

  11. Research Areas: Clinical Trials

    Science.gov (United States)

    Information about NCI programs and initiatives that sponsor, conduct, develop, or support clinical trials, including NCI’s Clinical Trial Network (NCTN) and NCI Community Oncology Research Program (NCORP) initiatives.

  12. Fertility Clinic Success Rates

    Science.gov (United States)

    ... and Autism 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook Tweet Share Compartir 2013 ART Fertility Clinic Success Rates Report [PDF - 1MB] Bookmarks and thumbnails are ...

  13. Inhalational anaesthesia with low fresh gas flow

    Directory of Open Access Journals (Sweden)

    Christian Hönemann

    2013-01-01

    Full Text Available During the inhalation of anaesthesia use of low fresh gas flow (0.35-1 L/min has some important advantages. There are three areas of benefit: pulmonary - anaesthesia with low fresh gas flow improves the dynamics of inhaled anaesthesia gas, increases mucociliary clearance, maintains body temperature and reduces water loss. Economic - reduction of anaesthesia gas consumption resulting in significant savings of > 75% and Ecological - reduction in nitrous oxide consumption, which is an important ozone-depleting and heat-trapping greenhouse gas that is emitted. Nevertheless, anaesthesia with high fresh gas flows of 2-6 L/min is still performed, a technique in which rebreathing is practically negligible. This special article describes the clinical use of conventional plenum vaporizers, connected to the fresh gas supply to easily perform low (1 L/min, minimal (0.5 L/min or metabolic flow anaesthesia (0.35 L/min with conventional Primus Draeger® anaesthesia machines in routine clinical practice.

  14. Use of the RACE technique for quantitative flow measurements

    International Nuclear Information System (INIS)

    A phantom has been designed for measuring flow velocities; using pipes of specified diameter and selectable pulse rates, flow rates varying from 0-250 cm/s can be determined. The measurements are made in a superconductive magnet with a field strength of 1.5 Tesla, employing a RACE technique. The reference technique was electromagnetic flow measurement. There was good linear correlation between the electromagnetic and the MRT results with a correlation coefficient of 0.98. It is necessary in the first place to estimate flow speed; if flow velocity is unknown initially, there is no correlation. Hence, in everyday use erroneous results may be obtained, particularly since one cannot always demonstrate vessels in all parts of the body without superimposition. Further clinical studies are required in various vascular territories to evaluate the usefulness of the RACE technique for flow measurements. (orig.)

  15. Vertical countercurrent flow limitation phenomena under oscillatory gas flow

    International Nuclear Information System (INIS)

    During the hypothetical loss of coolant accident in a nuclear power plant, the emergency core cooling water could not penetrate to the reactor core when the steam flow rate from the reactor core exceeds CCFL (Countercurrent flow limitation). The criteria of CCFL generated by earlier investigators were developed under steady gas flow. However, the flow instability in the reactor loop could generate oscillatory steam flow, hence their applicability under oscillating flow should be investigated. In this work, an experimental investigation of countercurrent flow in a vertical flow channel has been conducted under oscillatory gas flow condition. In the present flooding loop, flooding occurs from the annular flow regime, annular flooding, or the periodic slug/annular flow regime, slug flooding. The oscillatory gas flow changes the flooding map of the steady gas flow according to its magnitude and oscillating frequency. Further, when its minimum gas flow rate is less than a threshold value, no flooding was observed. When it was annular flow regime, the threshold of no flooding was the deflooding value under the steady gas flow. But when it was the slug or periodic slug/annular flow regime, the threshold of no flooding was in between the deflooding and flooding value under steady gas flow. Also, it was observed that this no flooding threshold is insensitive to the oscillating frequency except for high frequency over 0.3 Hz. Therefore, the flooding condition under oscillatory gas flow is less restrictive than that under steady gas flow

  16. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... was provided by the National Library of Medicine Topic last reviewed: December 2013 For an enhanced version of this page please turn Javascript on. Participating in Clinical Trials About Clinical Trials A Research Study With Human Subjects A clinical trial is ...

  17. Evolution of Clinical Enzymology

    OpenAIRE

    Büttner, J

    1981-01-01

    The evolution of clinical enzymology is discussed in relation to the history of general enzymology and clinical chemistry. The discussion is limited to the period from 1835 (definition of catalysis by Berzelius) to 1935 (description of the optical test by Warburg). In conclusion, a general account is given of the introduction of the concept of quantitative enzyme activity determination into clinical medicine.

  18. Clinical Process Intelligence

    DEFF Research Database (Denmark)

    Vilstrup Pedersen, Klaus

    2006-01-01

    Ideally, clinical guidelines are created from evidence based medicine. Translating the narrative semi-structured article for-mat of the clinical guidelines into a computable language makes it possible to utilize this information in IT-supported clinical reasoning, and thereby bring the relevant...

  19. Clinical document architecture.

    Science.gov (United States)

    Heitmann, Kai

    2003-01-01

    The Clinical Document Architecture (CDA), a standard developed by the Health Level Seven organisation (HL7), is an ANSI approved document architecture for exchange of clinical information using XML. A CDA document is comprised of a header with associated vocabularies and a body containing the structural clinical information. PMID:15061557

  20. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... topic was provided by the National Library of Medicine Topic last reviewed: December 2013 For an enhanced version of this page please turn Javascript on. Participating in Clinical Trials About Clinical Trials A Research Study With Human Subjects A clinical trial is a research study ...

  1. Spina Bifida Clinic Directory

    Science.gov (United States)

    ... 798,163.html Back to top Missouri Children’s Mercy Hospital & Clinics Spinal Defects Clinic (pediatric only-will ... 234-3790 or (816) 234 3005 www.childrens-mercy.org/ Cardinal Glennon Children’s Medical Center Myelomeningocele Clinic ( ...

  2. 4D flow mri post-processing strategies for neuropathologies

    Science.gov (United States)

    Schrauben, Eric Mathew

    4D flow MRI allows for the measurement of a dynamic 3D velocity vector field. Blood flow velocities in large vascular territories can be qualitatively visualized with the added benefit of quantitative probing. Within cranial pathologies theorized to have vascular-based contributions or effects, 4D flow MRI provides a unique platform for comprehensive assessment of hemodynamic parameters. Targeted blood flow derived measurements, such as flow rate, pulsatility, retrograde flow, or wall shear stress may provide insight into the onset or characterization of more complex neuropathologies. Therefore, the thorough assessment of each parameter within the context of a given disease has important medical implications. Not surprisingly, the last decade has seen rapid growth in the use of 4D flow MRI. Data acquisition sequences are available to researchers on all major scanner platforms. However, the use has been limited mostly to small research trials. One major reason that has hindered the more widespread use and application in larger clinical trials is the complexity of the post-processing tasks and the lack of adequate tools for these tasks. Post-processing of 4D flow MRI must be semi-automated, fast, user-independent, robust, and reliably consistent for use in a clinical setting, within large patient studies, or across a multicenter trial. Development of proper post-processing methods coupled with systematic investigation in normal and patient populations pushes 4D flow MRI closer to clinical realization while elucidating potential underlying neuropathological origins. Within this framework, the work in this thesis assesses venous flow reproducibility and internal consistency in a healthy population. A preliminary analysis of venous flow parameters in healthy controls and multiple sclerosis patients is performed in a large study employing 4D flow MRI. These studies are performed in the context of the chronic cerebrospinal venous insufficiency hypothesis. Additionally, a

  3. Relationship between clinical pathophysiology and pulmonary pathology in patients with congenital heart defects and decreased pulmonary artery blood flow%肺血少型先天性心脏病肺血管病理变化及临床病理生理关系

    Institute of Scientific and Technical Information of China (English)

    许耀强; 刘迎龙; 阮英茆; 吕小东; 于存涛; 李莉

    2008-01-01

    Objective To investigate the relationship between pulmonary pathological features and clinical physiology of congenital heart defects (CHD) with decreased pulmonary artery blood flow.Methods Between July 2001 and May 2006,18 patients with CHD with decreased pulmonary artery blood flow undergoing palliative or definitive repair and having lung biopsy intraoperatively were enrolled in this study.The patients'age was 0.4-8.0 years,and body weight was 6.0-20.0 kg.The method of semi-quantitative morphometric technique and an image analyzer were applied to measure the following indices of pulmonary microveszels:the percentage of media thickness (MT%),the percentage of media section area(MS%) and numbers of microvessels per square centimeter (VPSC).The diameters of left pulmonary artery (LPA) and right pulmonary artery (RPA)were measured with two-dimensional echocardiography.The percutaneous oxygen saturation (SpO2),hemoglobin concentration (HB) and hematocrit value (HCT) were examined and recorded preoperatively.Results There was a significant negative correlation between SpO2 and HCT or lib (R2=0.4914,P=0.001 and R2=0.5505,P <0.001),the variation trend of these three variables was linked.There was a negative correlation between SpO2 and the body weight (R2=0.2208,P=0.049),which is in accordance with clinical features of aggravated process of cyanosis and hypoxia.The morphological observation of lung biopsy specimens indicated that most of peripheral pulmonary arteries were distended,irregular and their walls were uneven,and "lake" type of pulmonary AV malformations were observed.There was a positive correlation between VPSC and the body weight or BSA (R2=0.5472,P <0.001 and R2=0.5233,P=0.001).There was a significant correlation between VPSC and LPA or RPA (R2=0.4312,P=0.003 and R2=0.2463,P=0.036).It was shown that the diameter of central pulmonary arteries could be a reflection of peripheral pulmonary artery growth.The diameter of LPA also correlated with the

  4. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

  5. Counting RG flows

    Science.gov (United States)

    Gukov, Sergei

    2016-01-01

    Interpreting renormalization group flows as solitons interpolating between different fixed points, we ask various questions that are normally asked in soliton physics but not in renormalization theory. Can one count RG flows? Are there different "topological sectors" for RG flows? What is the moduli space of an RG flow, and how does it compare to familiar moduli spaces of (supersymmetric) dowain walls? Analyzing these questions in a wide variety of contexts — from counting RG walls to AdS/CFT correspondence — will not only provide favorable answers, but will also lead us to a unified general framework that is powerful enough to account for peculiar RG flows and predict new physical phenomena. Namely, using Bott's version of Morse theory we relate the topology of conformal manifolds to certain properties of RG flows that can be used as precise diagnostics and "topological obstructions" for the strong form of the C-theorem in any dimension. Moreover, this framework suggests a precise mechanism for how the violation of the strong C-theorem happens and predicts "phase transitions" along the RG flow when the topological obstruction is non-trivial. Along the way, we also find new conformal manifolds in well-known 4d CFT's and point out connections with the superconformal index and classifying spaces of global symmetry groups.

  6. Reactivity to low‐flow as a potential determinant for brachial artery flow‐mediated vasodilatation

    OpenAIRE

    Aizawa, Kunihiko; Elyas, Salim; Adingupu, Damilola D.; Casanova, Francesco; Gooding, Kim M.; Strain, W. David; Shore, Angela C.; Gates, Phillip E.

    2016-01-01

    Abstract Previous studies have reported a vasoconstrictor response in the radial artery during a cuff‐induced low‐flow condition, but a similar low‐flow condition in the brachial artery results in nonuniform reactivity. This variable reactivity to low‐flow influences the subsequent flow‐mediated dilatation (FMD) response following cuff‐release. However, it is uncertain whether reactivity to low‐flow is important in data interpretation in clinical populations and older adults. This study aimed...

  7. Elliptic flow phenomenon at ATLAS

    OpenAIRE

    Spousta, Martin

    2014-01-01

    We summarize measurements of elliptic flow and higher order flow harmonics performed by the ATLAS experiment at the LHC. Results on event-averaged flow measurements and event-plane correlations in Pb+Pb collisions are discussed along with the event-by-event flow measurements. Further, we summarize results on flow in p+Pb collisions.

  8. Wealth-flow forecasting

    OpenAIRE

    Bradut BOLOS

    2008-01-01

    The Wealth Flow is part of an ABC type approach, and should suggest the wealth either generated (by income recognized in accounting, or not) or consumed (by recognized expenses or not). From the investor’s point of view this should be the next stage of analyze after the cash flow analyze, showing his net benefits generated by an investment. In a final stage the wealth flow should be a sum of shares value growth and dividends, however as the market is not always responding immediately and dire...

  9. Bypass Flow Study

    International Nuclear Information System (INIS)

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  10. Control of Unstable Flows

    Institute of Scientific and Technical Information of China (English)

    刘曾荣; 茅坚民

    2003-01-01

    Without introducing a discrete model, unstable continuous flows in a neighbourhood of an unstable stationary point can be stabilized. The linear part of the vector field of disturbing the flow can be managed to become the state variable multiplied by a negative constant. The nonlinear part of the vector field keeps to be unchanged,therefore flows far away from the stationary point are almost unaffected by the disturbance. The control method is easy to be used, even for practical problems for which a priori analytical knowledge of system dynamics is unavailable.

  11. Validated dynamic flow model

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2011-01-01

    The purpose with this deliverable 2.5 is to use fresh experimental data for validation and selection of a flow model to be used for control design in WP3-4. Initially the idea was to investigate the models developed in WP2. However, in the project it was agreed to include and focus on a additive...... model turns out not to be useful for prediction of the flow. Moreover, standard Box Jenkins model structures and multiple output auto regressive models proves to be superior as they can give useful predictions of the flow....

  12. Bypass Flow Study

    Energy Technology Data Exchange (ETDEWEB)

    Richard Schultz

    2011-09-01

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  13. Initiation of slug flow

    Energy Technology Data Exchange (ETDEWEB)

    Hanratty, T.J.; Woods, B.D. [Univ. of Illinois, Urbana, IL (United States)

    1995-12-31

    The initiation of slug flow in a horizontal pipe can be predicted either by considering the stability of a slug or by considering the stability of a stratified flow. Measurements of the shedding rate of slugs are used to define necessary conditions for the existence of a slug. Recent results show that slugs develop from an unstable stratified flow through the evolution of small wavelength waves into large wavelength waves that have the possibility of growing to form a slug. The mechanism appears to be quite different for fluids with viscosities close to water than for fluids with large viscosities (20 centipoise).

  14. Refrigeration. Two-Phase Flow. Flow Regimes and Pressure Drop

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard

    2002-01-01

    The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature....

  15. Analysis of liposomes using asymmetrical flow field-flow fractionation

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Decker, Christiane; Fahr, Alfred

    2012-01-01

    Liposomes composed of dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylglycerol were analyzed by asymmetrical flow field-flow fractionation coupled with multi-angle laser light scattering. In addition to evaluation of fractionation conditions (flow conditions, sample mass, carrier liquid...

  16. Flow Measuring Techniques in Steady and Pulsating Compressible Flows

    OpenAIRE

    Laurantzon, Fredrik

    2010-01-01

    This thesis deals with flow measuring techniques applied on steady and pulsatingflows. Specifically, it is focused on gas flows where density changes canbe significant, i.e. compressible flows. In such flows only the mass flow ratehas a significance and not the volume flow rate since the latter depends onthe pressure. The motivation for the present study is found in the use of flowmeters for various purposes in the gas exchange system for internal combustionengines. Applications can be found ...

  17. Clinical Management of Priapism: A Review.

    Science.gov (United States)

    Shigehara, Kazuyoshi; Namiki, Mikio

    2016-04-01

    Priapism is defined as a persistent and painful erection lasting longer than four hours without sexual stimulation. Based on episode history and pathophysiology, priapism is classified into three subtypes: ischemic (low-flow), non-ischemic (high-flow), and stuttering priapism. Ischemic priapism is characterized by a persistent, painful erection with remarkable rigidity of the corpora cavernosa caused by a disorder of venous blood outflow from this tissue mass, and is similar to penile compartment syndrome. Stuttering priapism is characterized by a self-limited, recurrent, and intermittent erection, frequently occurring in patients with sickle cell disease. Non-ischemic priapism is characterized by a painless, persistent nonsexual erection that is not fully rigid and is caused by excess arterial blood flow into the corpora cavernosa. Because ischemic and non-ischemic priapism differ based on emergency status and treatment options, appropriate discrimination of each type of priapism is required to initiate adequate clinical management. The goal of management of priapism is to achieve detumescence of the persistent penile erection and to preserve erectile function after resolution of the priapism. To achieve successful management, urologists should address this emergency clinical condition. In the present article, we review the diagnosis and clinical management of the three types of priapism. PMID:27169123

  18. Integrating clinical research into clinical decision making

    Directory of Open Access Journals (Sweden)

    Mark R Tonelli

    2011-01-01

    Full Text Available Evidence-based medicine has placed a general priority on knowledge gained from clinical research for clinical decision making. However, knowledge derived from empiric, population-based research, while valued for its ability to limit bias, is not directly applicable to the care of individual patients. The gap between clinical research and individual patient care centers on the fact that empiric research is not generally designed to answer questions of direct relevance to individual patients. Clinicians must utilize other forms of medical knowledge, including pathophysiologic rationale and clinical experience, in order to arrive at the best medical decision for a particular patient. In addition, clinicians must also elucidate and account for the goals and values of individual patients as well as barriers and facilitators of care inherent in the system in which they practice. Evidence-based guidelines and protocols, then, can never be prescriptive. Clinicians must continue to rely on clinical judgment, negotiating potentially conflicting warrants for action, in an effort to arrive at the best decision for a particular patient.

  19. Flow visualization in long neck Helmholtz resonators with grazing flow

    Science.gov (United States)

    Baumeister, K. J.; Rice, E. J.

    1976-01-01

    Both oscillating and steady flows were applied to a single plexiglass resonator cavity with colored dyes injected in both the orifice and grazing flow field to record the motion of the fluid. For oscillatory flow, the instantaneous dye streamlines were similar for both the short and long-neck orifices. The orifice flow blockage appears to be independent of orifice length for a fixed amplitude of flow oscillation and magnitude of the grazing flow. The steady flow dye studies showed that the acoustic and steady flow resistances do not necessarily correspond for long neck orifices.

  20. Multicomponent flow modeling

    Institute of Scientific and Technical Information of China (English)

    GIOVANGIGLI; Vincent

    2012-01-01

    We present multicomponent flow models derived from the kinetic theory of gases and investigate the symmetric hyperbolic-parabolic structure of the resulting system of partial differential equations.We address the Cauchy problem for smooth solutions as well as the existence of deflagration waves,also termed anchored waves.We further discuss related models which have a similar hyperbolic-parabolic structure,notably the SaintVenant system with a temperature equation as well as the equations governing chemical equilibrium flows.We next investigate multicomponent ionized and magnetized flow models with anisotropic transport fluxes which have a different mathematical structure.We finally discuss numerical algorithms specifically devoted to complex chemistry flows,in particular the evaluation of multicomponent transport properties,as well as the impact of multicomponent transport.

  1. Parallel flow diffusion battery

    Science.gov (United States)

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  2. Flow Cytometry Section

    Data.gov (United States)

    Federal Laboratory Consortium — The primary goal of the Flow Cytometry Section is to provide the services of state-of-the-art multi-parameter cellular analysis and cell sorting for researchers and...

  3. Hovering in Oscillatory Flows

    CERN Document Server

    Huang, Yangyang; Kanso, Eva

    2015-01-01

    We investigate the hovering dynamics of rigid bodies with up-down asymmetry placed in oscillating background flows. Recent experiments on inanimate pyramid-shaped objects in oscillating flows with zero mean component demonstrate that the resulting aerodynamic forces are sufficient to keep the object aloft. The mechanisms responsible for this lift production are fundamentally unsteady and depend on the shed vorticity. Here, we consider a model system of a two-dimensional flyer and compute the unsteady, two-way coupling between the flyer and the surrounding fluid in the context of the vortex sheet model. We examine in detail the flow properties (frequency and speed) required for hovering and their dependence on the flyer's characteristics (mass and geometry). We find that the aerodynamic effort required to hover is an intrinsic property of the flyer itself: a given flyer requires a constant amount of effort to hover, irrespective of the frequency and speed of the oscillating flow. This physical insight will pot...

  4. Reversed extension flow

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.

    2008-01-01

    Afilament stretching rheometer (FSR) was used for measuring the start-up of uni-axial elongational flow followed by reversed bi-axial flow, both with a constant elongational rate. A narrow molecular mass distribution linear polystyrene with a molecular weight of 145 kg / mole wis subjected to the...... start-up of elongation for three Hencky strain units and subsequently the reversed flow. The integral molecular stress function formulation within the 'interchain pressure' concept agrees with the experiments. In the experiments the Hencky strain at which the str~ss becomes zero (the recovery strain) in...... the reversed flow has been identified. The recovery strain is found to increase with elongational rate, and has a maximum value of approximately 1.45. The Doi Edwards model using any stretch evolution equation is not able to predict the correct level of the recovery strain....

  5. RG flows and instantons

    International Nuclear Information System (INIS)

    In these two lectures I discuss RG flow solutions in (1,0) six dimensional supergravity involving SU(2) Yang-Mills instantons. in the conformally flat part of the 6D metric. The solutions interpolate between two (4,0) supersymmetric AdS3×S3 backgrounds with different values of AdS3 and S3 radii and describe RG flows in the dual 2D SCFT. The flows described are of v.e.v. type, driven by a vacuum expectation value of a (not exactly) marginal operator of dimension 2 in the UV. We give an interpretation of the supergravity solution in terms of the D1/D5 system in type I string theory on K3, whose effective field theory is expected to flow to a (4,0) SCFT in the infrared.

  6. Complex Flow Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-05-01

    This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.

  7. Optimal Flow Control Design

    Science.gov (United States)

    Allan, Brian; Owens, Lewis

    2010-01-01

    In support of the Blended-Wing-Body aircraft concept, a new flow control hybrid vane/jet design has been developed for use in a boundary-layer-ingesting (BLI) offset inlet in transonic flows. This inlet flow control is designed to minimize the engine fan-face distortion levels and the first five Fourier harmonic half amplitudes while maximizing the inlet pressure recovery. This concept represents a potentially enabling technology for quieter and more environmentally friendly transport aircraft. An optimum vane design was found by minimizing the engine fan-face distortion, DC60, and the first five Fourier harmonic half amplitudes, while maximizing the total pressure recovery. The optimal vane design was then used in a BLI inlet wind tunnel experiment at NASA Langley's 0.3-meter transonic cryogenic tunnel. The experimental results demonstrated an 80-percent decrease in DPCPavg, the reduction in the circumferential distortion levels, at an inlet mass flow rate corresponding to the middle of the operational range at the cruise condition. Even though the vanes were designed at a single inlet mass flow rate, they performed very well over the entire inlet mass flow range tested in the wind tunnel experiment with the addition of a small amount of jet flow control. While the circumferential distortion was decreased, the radial distortion on the outer rings at the aerodynamic interface plane (AIP) increased. This was a result of the large boundary layer being distributed from the bottom of the AIP in the baseline case to the outer edges of the AIP when using the vortex generator (VG) vane flow control. Experimental results, as already mentioned, showed an 80-percent reduction of DPCPavg, the circumferential distortion level at the engine fan-face. The hybrid approach leverages strengths of vane and jet flow control devices, increasing inlet performance over a broader operational range with significant reduction in mass flow requirements. Minimal distortion level requirements

  8. Flow cytometry bioinformatics.

    Directory of Open Access Journals (Sweden)

    Kieran O'Neill

    Full Text Available Flow cytometry bioinformatics is the application of bioinformatics to flow cytometry data, which involves storing, retrieving, organizing, and analyzing flow cytometry data using extensive computational resources and tools. Flow cytometry bioinformatics requires extensive use of and contributes to the development of techniques from computational statistics and machine learning. Flow cytometry and related methods allow the quantification of multiple independent biomarkers on large numbers of single cells. The rapid growth in the multidimensionality and throughput of flow cytometry data, particularly in the 2000s, has led to the creation of a variety of computational analysis methods, data standards, and public databases for the sharing of results. Computational methods exist to assist in the preprocessing of flow cytometry data, identifying cell populations within it, matching those cell populations across samples, and performing diagnosis and discovery using the results of previous steps. For preprocessing, this includes compensating for spectral overlap, transforming data onto scales conducive to visualization and analysis, assessing data for quality, and normalizing data across samples and experiments. For population identification, tools are available to aid traditional manual identification of populations in two-dimensional scatter plots (gating, to use dimensionality reduction to aid gating, and to find populations automatically in higher dimensional space in a variety of ways. It is also possible to characterize data in more comprehensive ways, such as the density-guided binary space partitioning technique known as probability binning, or by combinatorial gating. Finally, diagnosis using flow cytometry data can be aided by supervised learning techniques, and discovery of new cell types of biological importance by high-throughput statistical methods, as part of pipelines incorporating all of the aforementioned methods. Open standards, data

  9. Traffic Flow Theory

    OpenAIRE

    Maerivoet, Sven; De Moor, Bart

    2005-01-01

    The scientific field of traffic engineering encompasses a rich set of mathematical techniques, as well as researchers with entirely different backgrounds. This paper provides an overview of what is currently the state-of-the-art with respect to traffic flow theory. Starting with a brief history, we introduce the microscopic and macroscopic characteristics of vehicular traffic flows. Moving on, we review some performance indicators that allow us to assess the quality of traffic operations. A f...

  10. Flow on sweeping networks

    OpenAIRE

    Degond, Pierre; Herty, Michael; Liu, Jian-guo

    2013-01-01

    We introduce a cellular automaton model coupled with a transport equation for flows on graphs. The direction of the flow is described by a switching process where the switching probability dynamically changes according to the value of the transported quantity in the neighboring cells. A motivation is pedestrian dynamics in a small corridor where the propagation of people in a part of the corridor can be either left or rightgoing. Under the assumptions of propagation of chaos and mean-field li...

  11. Stability of parallel flows

    CERN Document Server

    Betchov, R

    2012-01-01

    Stability of Parallel Flows provides information pertinent to hydrodynamical stability. This book explores the stability problems that occur in various fields, including electronics, mechanics, oceanography, administration, economics, as well as naval and aeronautical engineering. Organized into two parts encompassing 10 chapters, this book starts with an overview of the general equations of a two-dimensional incompressible flow. This text then explores the stability of a laminar boundary layer and presents the equation of the inviscid approximation. Other chapters present the general equation

  12. Traffic-flow simulation

    OpenAIRE

    OMAHEN, ANDRAŽ

    2015-01-01

    This diploma thesis presents the behavior of program, which uses the traffic light enhanced transport network to simulate the traffic flow of vehicles that behave according to the IDM model. We upgraded the program to allow, for the given network, to optimize the traffic flow. Because of the overwhelming problem of road closures or their rearrangement, we added a graphical user interface with which a user can create or modify the road network to observe changes in traffic. The objective of...

  13. Nonlinearity in groundwater flow

    OpenAIRE

    Barends, F.B.J.

    1980-01-01

    Since 1856 when Darcy laid the basis for the calculation of the flow of water through sands, researchers have been interested in groundwater flow. Groundwater is essential for agriculture and water supply, but it also plays an important role when soil is used as a construction element, such as for dykes, roads and foundations. The mechanical behaviour of saturated or dry, fine graded or coarse soils are quite different. The theory of groundwater mechanics must be based on the system: water-so...

  14. Retinal flow cytometer

    OpenAIRE

    Alt, C.; Veilleux, I.; Lee, H; Pitsillides, C. M.; D. Côté; Lin, C.P.

    2007-01-01

    The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery–vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerv...

  15. Ozone flow visualization techniques

    Science.gov (United States)

    Dickerson, R. R.; Stedman, D. H.

    1981-01-01

    Flow visualization techniques using ozone for tracing gas flows are proposed whereby ozone is detected through its strong absorption of ultraviolet light, which is easily made visible with fluorescent materials, or through its reaction with nitric oxide to form excited nitrogen dioxide, which in relaxing emits detectable light. It is shown that response speeds in the kHz range are possible with an ultraviolet detection system for initial ozone concentrations of about 1%.

  16. Ricci Flow Gravity

    OpenAIRE

    2006-01-01

    A theory of gravitation is proposed, modeled after the notion of a Ricci flow. In addition to the metric an independent volume enters as a fundamental geometric structure. Einstein gravity is included as a limiting case. Despite being a scalar-tensor theory the coupling to matter is different from Jordan-Brans-Dicke gravity. In particular there is no adjustable coupling constant. For the solar system the effects of Ricci flow gravity cannot be distinguished from Einstein gravity and therefore...

  17. Fundamentals of Multiphase Flow

    OpenAIRE

    Brennen, Christopher Earls

    2005-01-01

    The subject of multiphase flows encompasses a vast field, a host of different technological contexts, a wide spectrum of different scales, a broad range of engineering disciplines and a multitude of different analytical approaches. Not surprisingly, the number of books dealing with the subject is voluminous. For the student or researcher in the field of multiphase flow this broad spectrum presents a problem for the experimental or analytical methodologies that might be appro...

  18. Flow assurance study

    OpenAIRE

    Böser, W.; Belfroid, S.P.C.

    2013-01-01

    Generally large scale carbon capture projects require pipeline systems for the transporting of the CO2 from its point of capture to the storage site. The article will give information on the proposed operational management system. This has to work for all process situations, ranging from steady flow at varying injection conditions and flow rates, to start-up and shutdown procedures and also for emergency shutdown at the platform. In all these operational situations the phase behaviour of CO2 ...

  19. Information Flow Testing

    OpenAIRE

    Le Guernic, Gurvan

    2007-01-01

    Noninterference, which is an information flow property, is typically used as a baseline security policy to formalize confidentiality of secret information manipulated by a program. Noninterference verification mechanisms are usually based on static analyses and, to a lesser extent, on dynamic analyses. In contrast to those works, this paper proposes an information flow testing mechanism. This mechanism is sound from the point of view of noninterference. It is based on standard testing techniq...

  20. Gross loan flows

    OpenAIRE

    Craig, Ben R.; Joseph G. Haubrich

    2000-01-01

    We present a series of stylized facts about gross loan flows and how they vary over time, bank size, and region. We define loan creation as the sum of the change in bank loans at all banks that increased loans since last quarter. Loan destruction is similarly defined as the absolute value of the change in loans at all banks that decreased loans. The gross flow (akin to what the labor literature calls reallocation) is the sum of creation and destruction.

  1. Electrochemical flow capacitors

    Science.gov (United States)

    Gogotsi, Yury; Presser, Volker; Kumbur, Emin Caglan

    2015-10-27

    The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).

  2. Alkaline quinone flow battery

    OpenAIRE

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise Ann; Valle, Alvaro West; Hardee, D.; Gordon, Roy Gerald; Aziz, Michael J.; Marshak, M

    2015-01-01

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe f...

  3. Blood Flow Multiscale Phenomena

    OpenAIRE

    Agić, Ante; Mijović, Budimir; Nikolić, Tatjana

    2007-01-01

    The cardiovascular disease is one of most frequent cause deaths in modern society. The objective of this work is analyse the effect of dynamic vascular geometry (curvature, torsion,bifurcation) and pulsatile blood nature on secondary flow, wall shear stress and platelet deposition. The problem was examined as multi-scale physical phenomena using perturbation analysis and numerical modelling. The secondary flow determined as influence pulsatile pressure, vascular tube time-dependen...

  4. Simulation of blood flow in a small-diameter vascular graft model with a swirl (spiral) flow guider

    Institute of Scientific and Technical Information of China (English)

    Robert; GUIDOIN

    2008-01-01

    Small-diameter vascular grafts are in large demand for coronary and peripheral bypass procedures, but present products still fail in long-term clinical application. In the present communication, a new type of small-diameter graft with a swirl flow guider was proposed to improve graft patency rate. Flow pattern in the graft was simulated numerically and compared with that in a conventional graft. The numerical results revealed that the swirl flow guider could indeed make the blood flow rotate in the new graft. The swirling flow distal to the flow guider significantly altered the flow pattern in the new graft and the ve- locity profiles were re-distributed. Due to the swirling flow, the blood velocity near the vessel wall and wall shear rate were greatly enhanced. We believe that the increased blood velocity near the wall and the wall shear rate can impede the occurrence of acute thrombus formation and intimal hyperplasia, hence can improve the graft patency rate for long-term clinical use.

  5. Conjugate flow action functionals

    International Nuclear Information System (INIS)

    We present a new general framework to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gâteaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines

  6. Tank depletion flow instruments

    International Nuclear Information System (INIS)

    A new flowmetering system is developed to measure and control flow without the need for an inline flowmeter. Flowrate is determined from the rate of level change in reference vessel. This system is unique in its use of balance pots for zero suppression to enable range amplification. The result is an accuracy in flow measurement and control as good as $plus or minus$1%. The system uses state-of-the-art digital integrated circuits with a crystal time base in conjunction with the time-proven pneumatic bubbler probe low range transmitters. The benefits are (1) reduced radiation exposure to personnel during maintenance of flowmeters for radioactive streams since instruments are all located in an operating area isolated from the process by four feet of concrete, (2) reduced volume of solid nuclear wastes through processing efficiencies, (3) reduced cost of chemicals involved, (4) increased speed of flowrate determination, (5) reduced maintenance time and material cost to correct flow instrument component failures, (6) no obstruction to flow in the process stream, and (7) reduced cost of instrumentation to determine flowrate. A disadvantage is the requirement that flow must be related to tank level thus only one unknown flow into or out of a given vessel at a time may be metered and controlled. 1 ref

  7. Fanno Flow in Microchannels

    Directory of Open Access Journals (Sweden)

    M.A. Al-Nimr

    2012-12-01

    Full Text Available In this study, the Fanno flow problem has been theoretically investigated using both, first order and second order velocity-slip boundary conditions models and then compared to the no-slip boundary conditions solution. The objective is to study the behavior of the flow predicted by the two slip models. Then, an attempt will be made to establish criteria for using the no-slip and the two velocity-slip models. The Fanno flow is an ideal gas adiabatic flow in constant area duct with friction. It is found that the velocity profile for the two velocity-slip models has the same shape as the no-slip model velocity profile but with an amount of slip at the wall which increases as the Knudsen number, Kn, increases. Also the effect of the slip has on the compressible flow characteristics have been examined. It shows that as the Kn increases, the skin friction coefficient Cf and the Darcy friction coefficient f decrease. Overall, it is concluded that for an adiabatic compressible flow in circular microchannel, for Kn≤0.01 there is no need to apply any velocity-slip model as the no-slip model gives sufficiently accurate predictions. As for the range 0.01≤Kn≤0.1, the first order velocity slip model should be applied and so for this range, there is no necessity to use the second order velocity-slip model.

  8. Children and Clinical Studies: Why Clinical Studies Are Important

    Medline Plus

    Full Text Available ... NHLBI Trials Clinical Trial Websites Children and Clinical Studies Learn more about Children and Clinical Studies Importance of Children in Clinical Studies Children have often had to accept medicines and ...

  9. Which Way Is the Flow?

    Science.gov (United States)

    Kao, David

    1999-01-01

    The line integral convolution (LIC) technique has been known to be an effective tool for depicting flow patterns in a given vector field. There have been many extensions to make it run faster and reveal useful flow information such as velocity magnitude, motion, and direction. There are also extensions to unsteady flows and 3D vector fields. Surprisingly, none of these extensions automatically highlight flow features, which often represent the most important and interesting physical flow phenomena. In this sketch, a method for highlighting flow direction in LIC images is presented. The method gives an intuitive impression of flow direction in the given vector field and automatically reveals saddle points in the flow.

  10. A Cryogenic Flow Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Technologies Group, Inc. proposes the development of a Cryogenic Flow Sensor (CFS) for determining mass flow of cryogens in spacecraft propellant...

  11. Recommendations for quality assurance in multiparametric flow cytometry: first consensus of the Brazilian Group of Flow Cytometry (GBCFLUX)

    OpenAIRE

    Rodolfo P. Correia; Ana Carolina A. Bortolucci; Annelise C. W. Lopes; Alex F. Sandes; Ana Paula de Azambuja; Marta A. Viana; Maria M. Sales; Mihoko Yamamoto; Nydia S. Bacal

    2015-01-01

    ABSTRACT The Brazilian Group of Flow Cytometry (Grupo Brasileiro de Citometria de Fluxo [GBCFLUX]), founded on April 24, 2010, is composed of experts in flow cytometry (FC) area who have the common objective of contributing to technical and scientific advances in Brazilian clinical and research laboratories. Among GBCFLUX working groups, the Quality Control (QC) subcommittee is responsible for discussing data in the literature and contributes to the quality assurance of the pre-analytical, an...

  12. Hyperthermia: Clinical promise and current challenges

    International Nuclear Information System (INIS)

    Local-regional hyperthermia (HT) when used in conjunction with radiation therapy (XRT), has been shown in numerous clinical trials to result in considerable improvement in response rates and local tumor control rates when compared with treatment by XRT alone. Although considerable progress has been made in understanding the biological basis for hyperthermia induced cytotoxicity and radiosensitization, additional research remains in establishing the optimal treatment schedules for the clinical utilization of HT-XRT. The number of HT treatments; the sequencing of HT and XRT; the frequency of administration of HT; and the ideal temperature-time parameters all remain to be better defined for the clinical setting. The role of tumor blood flow on the thermal distributions also warrants further investigation. In addition, considerable effort is needed to improve hyperthermia equipment in order to provide more uniform therapeutic temperature distributions (temperatures ≥42.5%C). Better heating equipment is particularly needed for the treatment of deep seeted tumors. Pertinent clinical literature will be presented summarizing the clinical promise of hyperthermia and the above mentioned clinical challenges

  13. Everting (toposcopic) catheter for broad clinical application.

    Science.gov (United States)

    Shook, D R; Doppman, J L; Cattau, E L; Goldstein, S R

    1986-05-01

    The advanced development of the clinical everting (toposcopic) catheter is described. A detailed discussion of the design and outline of the fabrication techniques are followed by a thorough performance evaluation and summary of the first two clinical applications. The everting element is a low-durometer thermoplastic polyurethane elastomer. Surface treatments include the bonding of a hydrophilic polymeric coating, optimized for lubricity, to the sliding internal surfaces of the catheter. Eversion pressures and infusion/aspiration flow rates have been measured under various conditions and the infusate-in-blood mixing potential investigated. A preliminary assessment is given of the clinical performance of the catheter in the vascular delivery of chemotherapy and standard endoscopic retrograde cholangiopancreatography. PMID:3724105

  14. Clinical Genomic Database

    OpenAIRE

    Solomon, Benjamin D.; Nguyen, Anh-Dao; Bear, Kelly A.; Wolfsberg, Tyra G.

    2013-01-01

    Technological advances have greatly increased the availability of human genomic sequencing. However, the capacity to analyze genomic data in a clinically meaningful way lags behind the ability to generate such data. To help address this obstacle, we reviewed all conditions with genetic causes and constructed the Clinical Genomic Database (CGD) (http://research.nhgri.nih.gov/CGD/), a searchable, freely Web-accessible database of conditions based on the clinical utility of genetic diagnosis and...

  15. CME ON CLINICAL RESEARCH

    OpenAIRE

    Suneel. I. Majagi; S. S. Torgal; S. V. Hiremath

    2012-01-01

    Safety and efficacy are the two major concerns for any drug therapy. Globally clinical research plays an inevitable role in bringing a new molecule into the market after its synthesis by the pharmaceutical industries. Availability of large patient population, highly educated and skilled manpower, wide spectrum of diseases and favorable economic environment imply India’s potential as a global hub for clinical research. Pharmaceutical companies and Clinical Research Organization (CRO)s will req...

  16. Compliance in clinical trials.

    OpenAIRE

    Pullar, T; Kumar, S; Feely, M

    1989-01-01

    Compliance with treatment can be an important determinant of the outcome of clinical trials. To date there is no completely satisfactory method of measuring compliance and some of the most widely used methods are inadequate. The various methods of measuring compliance and how they have been applied to clinical trials are described, and improvements in the standard of the measurement and reporting of compliance in clinical trials are suggested.

  17. Physics of Zonal Flows

    Science.gov (United States)

    Itoh, Kimitaka

    2005-10-01

    This talk describes an overview of zonal flow physics, covering the theory, simulation and experiment. The zonal flows are excited nonlinearly by drift wave fluctuations, and suppress the turbulence and transport, so as to realize a self-regulating state for turbulence and mesoscale structure. This recognition is the central of recent paradigm shift in plasma physics, i.e., the preceding linear, local and deterministic pictures of instability and transport have been taken over by the new nonlinear, nonlocal (in real and wavenumber spaces) and statistical pictures of them. The zonal flow phenomenon, i.e., the global axial vector fields are generated by the release of global free energy in scalar fields through exciting turbulence, is a typical example of the fundamental issues in modern physics. In this review, the progresses made by theory and simulations, such as the linear damping rate, nonlinear mechanisms for growth and saturation, law of energy partition between turbulence and flow, life time of zonal flow, and so on, are explained. The transport by drift wave fluctuations, which are dressed by zonal flows, is discussed. Then experimental observations and verifications, which have been piled up rapidly in basic plasma experiments and confinement research, are explained, highlighting the integration with theory and simulation. Generalization to include magnetic field (zonal field) is addressed, in the light of the study of dynamo. Zonal flows in both laboratory and planetary-solar circumstances are discussed as well. This presentation illustrates the fast evolution of the physics of turbulence and structure formation of plasmas in the nature and laboratory. In collaboration with S.-I. Itoh, P. H. Diamond, T. S. Hahm, A. Fujisawa, G. R. Tynan and M. Yagi.

  18. Soil Heat Flow Model

    Science.gov (United States)

    Varas, E.; Nunez, C.; Meza, F. J.

    2008-12-01

    The Penman-Monteith method for estimating evapotranspiration (ET) has been recommended by FAO. This method requires measures of temperature, wind speed, relative humidity and heat flow in the soil. This last variable is rarely available. Soil heat flow is generally small compared to the net radiation, and many times is ignored in the energy balance. Nevertheless, the addition or subtraction of this amount in the energy balance equation should be considered for evapo-transpiration calculation. Penman-Monteith method suggests approximate estimates of soil heat flows as the difference between the maxima and minimum daily temperatures multiplied by a convenient coefficient. However, such approach ignores important variations in this parameter occurring during the day, and could influence the accuracy of the result. This work proposes to estimate soil heat flows by means of a mathematical model that includes the estimate of soil temperatures profiles and heat flows as a function of thermal properties of the soil, such as difussivity and conductivity coefficients. The model calculates soil heat flows in three stages. The first estimates hourly air temperature based on the average daily temperature and Fourier series coefficients. The obtained hourly air temperature constitutes an input variable for the second stage of the model. Surface soil temperature is assumed to be equal to air temperature. The second stage, applies heat transfer principles, using the thermal properties of the soil in order to obtain the soil temperature profile in a one meter depth soil stratum. Finally, the results of the second stage are used to calculate the hourly heat flow in the soil and compare this estimate with other methods and with measured values. Calculated hourly temperatures reproduced observed values closely. Correlation coefficients between observed and calculated values for the three summer months are 0.98, 0.96 and 0.97. Hourly soil heat fluxes are also closely estimated, showing

  19. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  20. Clinical research informatics

    CERN Document Server

    Richesson, Rachel L

    2012-01-01

    This book provides foundational coverage of key areas, concepts, constructs, and approaches of medical informatics as it applies to clinical research activities, in both current settings and in light of emerging policies. The field of clinical research is fully characterized (in terms of study design and overarching business processes), and there is emphasis on information management aspects and informatics implications (including needed activities) within various clinical research environments. The purpose of the book is to provide an overview of clinical research (types), activities, and are

  1. Computational simulations of flow dynamics and blood damage through a bileaflet mechanical heart valve scaled to pediatric size and flow.

    Science.gov (United States)

    Yun, B Min; McElhinney, Doff B; Arjunon, Shiva; Mirabella, Lucia; Aidun, Cyrus K; Yoganathan, Ajit P

    2014-09-22

    Despite pressing needs, there are currently no FDA approved prosthetic valves available for use in the pediatric population. This study is performed for predictive assessment of blood damage in bileaflet mechanical heart valves (BMHVs) with pediatric sizing and flow conditions. A model of an adult-sized 23 mm St. Jude Medical (SJM) Regent(™) valve is selected for use in simulations, which is scaled in size for a 5-year old child and 6-month old infant. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow with thousands of suspended platelets for cases of adult, child, and infant BMHV flows. Adult BMHV flows demonstrate more disorganized small-scale flow features, but pediatric flows are associated with higher fluid shear stresses. Platelet damage in the pediatric cases is higher than in adult flow, highlighting thrombus complication dangers of pediatric BMHV flows. This does not necessarily suggest clinically important differences in thromboembolic potential. Highly damaged platelets in pediatric flows are primarily found far downstream of the valve, as there is less flow recirculation in pediatric flows. In addition, damage levels are well below expected thresholds for platelet activation. The extent of differences here documented between the pediatric and adult cases is of concern, demanding particular attention when pediatric valves are designed and manufactured. However, the differences between the pediatric and adult cases are not such that development of pediatric sized valves is untenable. This study may push for eventual approval of prosthetic valves resized for the pediatric population. Further studies will be necessary to determine the validity and potential thrombotic and clinical implications of these findings. PMID:25011622

  2. Venous flow velocity, venous volume and arterial blood flow

    International Nuclear Information System (INIS)

    The relationship of arterial blood flow and venous volume to venous flow velocity was studied in normal subjects. The effects of current modes of treatment in venous thrombosis and of a vasodilator drug on venous flow velocity were also investigated. Total calf flow and venous volume were measured by venous occlusion plethysmography while venous flow axial velocity was determined by the transit time of 131I albumin from calf to inguinal region. Local intravenous epinephrine administration induced venoconstriction and increased venous flow velocity. Intra-arterial isoproterenol and angiotensin increased and decreased arterial flow, respectively, with no change in venous flow velocity or volume, but local heat increased arterial flow and venous flow velocity with no change in venous volume. Local cold, despite venoconstriction, decreased venous flow velocity accompanied by decreased arterial flow. Intravenous heparin did not affect venous flow velocity. Intravenous but not oral nylidrin increased venous flow velocity. Therefore venous flow velocity can be significantly increased by venoconstriction, by large increases in arterial flow (local heat), and by a parenteral vasodilator drug. These experiments indicate that there is a basis for applying heat but not cold in the prevention and treatment of venous thrombosis

  3. American Association for Clinical Chemistry

    Science.gov (United States)

    ... indispensable patient care tool. Learn more IN CLINICAL CHEMISTRY ddPCR Quantification of Lymphoma Mutations Researchers have developed ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  4. Piezoelectric axial flow microvalve

    Science.gov (United States)

    Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.

    2007-01-09

    This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.

  5. Upscaling of Forchheimer flows

    KAUST Repository

    Aulisa, Eugenio

    2014-08-01

    In this work we propose upscaling method for nonlinear Forchheimer flow in heterogeneous porous media. The generalized Forchheimer law is considered for incompressible and slightly-compressible single-phase flows. We use recently developed analytical results (Aulisa et al., 2009) [1] and formulate the resulting system in terms of a degenerate nonlinear flow equation for the pressure with the nonlinearity depending on the pressure gradient. The coarse scale parameters for the steady state problem are determined so that the volumetric average of velocity of the flow in the domain on fine scale and on coarse scale are close. A flow-based coarsening approach is used, where the equivalent permeability tensor is first evaluated following streamline methods for linear cases, and modified in order to take into account the nonlinear effects. Compared to previous works (Garibotti and Peszynska, 2009) [2], (Durlofsky and Karimi-Fard) [3], this approach can be combined with rigorous mathematical upscaling theory for monotone operators, (Efendiev et al., 2004) [4], using our recent theoretical results (Aulisa et al., 2009) [1]. The developed upscaling algorithm for nonlinear steady state problems is effectively used for variety of heterogeneities in the domain of computation. Direct numerical computations for average velocity and productivity index justify the usage of the coarse scale parameters obtained for the special steady state case in the fully transient problem. For nonlinear case analytical upscaling formulas in stratified domain are obtained. Numerical results were compared to these analytical formulas and proved to be highly accurate. © 2014.

  6. Micromodel foam flow study

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, K.T.; Radke, C.J.

    1990-10-01

    Foams are often utilized as part of enhanced oil recovery techniques. This report presents the results of a micromodel foam flow study. Micromodels are valuable tools in uncovering capillary phenomena responsible for lamellae generation and coalescence during foam flow in porous media. Among the mechanisms observed are snap-off, weeping-flow breakup, and lamella division and leave behind. Coalescence mechanisms include dynamic capillary-pressure-induced lamella drainage and gas diffusion. These phenomena are sensitive to the mode of injection, the local capillary environment, and the geometry of the pore structure. An important consideration in presenting a tractable model of foam flow behavior is the ability to identify the pore-level mechanisms having the greatest impact on foam texture. The predominant mechanisms will vary depending upon the application for foam as an enhanced oil recovery (EOR) fluid. Both simultaneous gas and surfactant injection and surfactant alternating with gas injection (SAG) have been used to create foam for mobility control in EOR projects. The model developed is based on simultaneous gas and surfactant injection during steady-state conditions into a Berea sandstone core. The lamellae generation and coalescence mechanisms included in this model are snap-off, lamella division, and dynamic capillary-pressure-induced lamella drainage. This simplified steady-state model serves as a foundation for developing more complete rate expressions and for extending the population balance to handle transient foam flow behavior. 70 refs., 30 figs.

  7. Marte Vallis Platy Flows

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-442, 4 August 2003The Marte Vallis system, located east of Cerberus and west of Amazonis Planitia, is known for its array of broken, platy flow features. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a close-up view of some of these plates; they appear to be like puzzle pieces that have been broken apart and moved away from each other. The Mars science community has been discussing these features for the past several years--either the flows in Marte Vallis are lava flows, or mud flows. In either case, the material was very fluid and had a thin crust on its surface. As the material continued to flow through the valley system, the crust broke up into smaller plates that were then rafted some distance down the valley. This picture is located near 6.9oN, 182.8oW. It is illuminated by sunlight from the left.

  8. Clinical decision modeling system

    Directory of Open Access Journals (Sweden)

    Lyons-Weiler James

    2007-08-01

    Full Text Available Abstract Background Decision analysis techniques can be applied in complex situations involving uncertainty and the consideration of multiple objectives. Classical decision modeling techniques require elicitation of too many parameter estimates and their conditional (joint probabilities, and have not therefore been applied to the problem of identifying high-performance, cost-effective combinations of clinical options for diagnosis or treatments where many of the objectives are unknown or even unspecified. Methods We designed a Java-based software resource, the Clinical Decision Modeling System (CDMS, to implement Naïve Decision Modeling, and provide a use case based on published performance evaluation measures of various strategies for breast and lung cancer detection. Because cost estimates for many of the newer methods are not yet available, we assume equal cost. Our use case reveals numerous potentially high-performance combinations of clinical options for the detection of breast and lung cancer. Results Naïve Decision Modeling is a highly practical applied strategy which guides investigators through the process of establishing evidence-based integrative translational clinical research priorities. CDMS is not designed for clinical decision support. Inputs include performance evaluation measures and costs of various clinical options. The software finds trees with expected emergent performance characteristics and average cost per patient that meet stated filtering criteria. Key to the utility of the software is sophisticated graphical elements, including a tree browser, a receiver-operator characteristic surface plot, and a histogram of expected average cost per patient. The analysis pinpoints the potentially most relevant pairs of clinical options ('critical pairs' for which empirical estimates of conditional dependence may be critical. The assumption of independence can be tested with retrospective studies prior to the initiation of

  9. 双胎反向动脉灌注序列征中两胎脐动脉血流阻力指数差值对评估泵血儿预后的临床意义%Clinical value of diffe rence in umbilical artery blood flow resistive index between pump and acardiac twins in pre-dicting outcome of pump twin by twin reversed-arterial perfusion sequence

    Institute of Scientific and Technical Information of China (English)

    陈昌宇; 解丽梅

    2016-01-01

    Objective To investigate the clinical value of umbilical artery blood flow resistance index (RI) difference between pump twins and acardiacus fetus by twin reversed-arterial perfusion (TRAP) sequence. Methods A total of 15 pregnant women with TRAP in China Medical University Affiliated Shengjing Hospital from 2009 to 2014 were enrolled, aged 19-36 years old with mean age of 26.53 years old. The gestational age was 13 - 27 weeks with mean of 21.73 weeks. Umbilical artery blood flow RI of pump twin and acardiacus were respectively measured by ultrasound, and the difference value of umbilical artery blood flow RI was calculated. Results Three pump twins were detected as heart failure, the difference value of their umbilical artery blood flow RI were small as 0.05, 0.07 and 0.13, respectively, and intrauterine death occurred after one week. Eight cases were given radio frequency ablation therapy, the difference value of umbilical artery blood flow RI of 7 pump twins were 0.16 - 0.30, and fetus were survived. The one pump twin showed difference value of umbilical artery blood flow RI of 0.17, and intrauterine death occurred after surgery. The difference value of umbilical artery blood flow RI of one pump twin was 0.34, and given conservative treatment due to the poor blood flow in acardiacus. The difference value of umbilical artery blood flow RI of one pump twin was 0.10, which terminated the pregnancy for maternal pregnancy-induced hypertension. The difference value of umbilical artery blood flow RI of one pump twin was 0.20, which showed chromosomal abnormalities, and one case performed abortion for low gestational age. Conclusion It is demonstrated that the difference value of umbilical artery blood flow RI between pump twin and acardiacus is significant on evaluation and treatment of TRAP, which means the bigger the RI difference value, the better prognosis.%目的:探讨双胎反向动脉灌注序列征(TRAP)中泵血儿与无心畸胎脐动脉血流阻力

  10. Mapping blood flow directionality in the human brain.

    Science.gov (United States)

    Park, Sung-Hong; Do, Won-Joon; Choi, Seung Hong; Zhao, Tiejun; Bae, Kyongtae Ty

    2016-07-01

    Diffusion properties of tissue are often expressed on the basis of directional variance, i.e., diffusion tensor imaging. In comparison, common perfusion-weighted imaging such as arterial spin labeling yields perfusion in a scalar quantity. The purpose of this study was to test the feasibility of mapping cerebral blood flow directionality using alternate ascending/descending directional navigation (ALADDIN), a recently-developed arterial spin labeling technique with sensitivity to blood flow directions. ALADDIN was applied along 3 orthogonal directions to assess directional blood flow in a vector form and also along 6 equally-spaced directions to extract blood flow tensor matrix (P) based on a blood flow ellipsoid model. Tensor elements (eigenvalues, eigenvectors, etc) were calculated to investigate characteristics of the blood flow tensor, in comparison with time-of-flight MR angiogram. While the directions of the main eigenvectors were heterogeneous throughout the brain, regional clusters of blood flow directionality were reproducible across subjects. The technique could show heterogeneous blood flow directionality within and around brain tumor, which was different from that of the contralateral normal side. The proposed method is deemed to provide information of blood flow directionality, which has not been demonstrated before. The results warrant further studies to assess changes in the directionality map as a function of scan parameters, to understand the signal sources, to investigate the possibility of mapping local blood perfusion directionality, and to evaluate its usefulness for clinical diagnosis. PMID:26968145

  11. Alkaline quinone flow battery.

    Science.gov (United States)

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy. PMID:26404834

  12. Choked flow through cracks

    International Nuclear Information System (INIS)

    The leaks through steam-generator cracks are the subject of a research carried out in cooperation between EDF and UCL. A software called ECREVISSE to predict the mass flow rate has been developed and has been successfully validated. The purpose of the paper is to present the mathematical model used in ECREVISSE as well as some comparison between the results and the presently available data. The model takes into account the persistence of some metastable liquid in the crack and the special flow pattern which appears in such particular geometry. Although the model involves the use of several correlations (friction, heat transfer), no adjustment of parameters against the data has been needed, neither in the single-phase part of the flow, or in the two-phase part. (authors). 8 figs., 1 tab., 20 refs

  13. Gaseous Flows in Galaxies

    CERN Document Server

    Combes, F

    2007-01-01

    The gas component plays a major role in the dynamics of spiral galaxies, because of its dissipative character, and its ability to exchange angular momentum with stars in the disk. Due to its small velocity dispersion, it triggers gravitational instabilities, and the corresponding non-axisymmetric patterns produce gravity torques, which mediate these angular momentum exchanges. When a srong bar pattern develops with the same pattern speed all over the disk, only gas inside corotation can flow towards the center. But strong bars are not long lived in presence of gas, and multiple-speed spiral patterns can develop between bar phases, and help the galaxy to accrete external gas flowing from cosmic filaments. The gas is then intermittently driven to the galaxy center, to form nuclear starbursts and fuel an active nucleus. The various time-scales of these gaseous flows are described.

  14. Minimum Probability Flow Learning

    CERN Document Server

    Sohl-Dickstein, Jascha; DeWeese, Michael R

    2009-01-01

    Learning in probabilistic models is often severely hampered by the general intractability of the normalization factor and its derivatives. Here we propose a new learning technique that obviates the need to compute an intractable normalization factor or sample from the equilibrium distribution of the model. This is achieved by establishing dynamics that would transform the observed data distribution into the model distribution, and then setting as the objective the minimization of the initial flow of probability away from the data distribution. Score matching, minimum velocity learning, and certain forms of contrastive divergence are shown to be special cases of this learning technique. We demonstrate the application of minimum probability flow learning to parameter estimation in Ising models, deep belief networks, multivariate Gaussian distributions and a continuous model with a highly general energy function defined as a power series. In the Ising model case, minimum probability flow learning outperforms cur...

  15. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... In This Topic About Clinical Trials Risks and Benefits Terms to Know Finding a Clinical Trial Informed ... for more information Scientists usually do years of experiments in the laboratory and in animals before they even consider testing an experimental treatment ...

  16. Clinical coding. Code breakers.

    Science.gov (United States)

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships. PMID:15768716

  17. Clinical Psychology in Pakistan

    OpenAIRE

    Riffat Moazam Zaman

    1991-01-01

    This article reviews the state of psychology in Pakistan, with special reference to clinical psychology. The issues of statutory recognition, credentials required for practice, public perception of psychology, the practice of indigenous "clinical psychology", sources of payment for psychological services, and relations between psychologists and psychiatrists are reviewed.

  18. Developing Clinical Competence

    NARCIS (Netherlands)

    P.F. Wimmers (Paul)

    2006-01-01

    textabstractThe development of clinical competence is the main purpose of medical education. The long road to become clinically competent starts on the first day of medical school, and every institution strives to select the best students. The responsibility of medical schools is to train th

  19. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... In This Topic About Clinical Trials Risks and Benefits Terms to Know Finding a Clinical Trial Informed ... years of experiments in the laboratory and in animals before they even ... this early research occurs at universities and medical centers across the ...

  20. CLINICAL TRIALS.GOV

    Science.gov (United States)

    ClinicalTrials.gov provides patients, family members, health care professionals, and members of the public easy access to information on clinical trials for a wide range of diseases and conditions. The U.S. National Institutes of Health (NIH), through its National Library of Medi...

  1. Mean curvature flow without singularities

    OpenAIRE

    Sáez, Mariel; Schnürer, Oliver Christian

    2012-01-01

    We study graphical mean curvature flow of complete solutions defined on subsets of Euclidean space.We obtain smooth long time existence. The projections of the evolving graphs also solve mean curvature flow. Hence this approach allows us to smoothly flow through singularities by studying graphical mean curvature flow in one additional dimension.

  2. Fluid Flow at Branching Junctions

    OpenAIRE

    Sochi, Taha

    2013-01-01

    The flow of fluids at branching junctions plays important kinematic and dynamic roles in most biological and industrial flow systems. The present paper highlights some key issues related to the flow of fluids at these junctions with special emphasis on the biological flow networks particularly blood transportation vasculature.

  3. Interactive Flow in Exercise Pedagogy

    Science.gov (United States)

    Lloyd, Rebecca; Smith, Stephen

    2006-01-01

    A phenomenology of the bodily experience of interactive flow adds to Csikszentmihalyi's flow theory. Whereas Csikszentmihalyi attended to teachers' and students' experiences of flow separately, this inquiry explores flow through three water-inspired layers of physical interaction between fitness professionals and their clients. Teaching fitness is…

  4. Clinical PET application

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang-Moo; Hong, S. W.; Choi, C. W.; Yang, S. D.; Choi, J. S.; Kweon, O. J. et al. [Korea Cancer Center Hospital, Seoul (Korea)

    2000-12-01

    PET gives various metabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 1,327 cases of PET images were obtained, which resulted total income of 829,770,000won. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18} in a day. Manpower should be added for the second PET operation and RI production. 10 figs., 4 tabs. (Author)

  5. Multiphase cooling flows

    OpenAIRE

    Thomas, Peter A.

    1996-01-01

    I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \\emph{not} consistent with all possible emissivity profiles which can therefore be used as a test of the theory. In combination, they provide ...

  6. Three-Dimensional Flows

    CERN Document Server

    Araujo, Vitor; Viana, Marcelo

    2010-01-01

    In this book, the authors present the elements of a general theory for flows on three-dimensional compact boundaryless manifolds, encompassing flows with equilibria accumulated by regular orbits. The book aims to provide a global perspective of this theory and make it easier for the reader to digest the growing literature on this subject. This is not the first book on the subject of dynamical systems, but there are distinct aspects which together make this book unique. Firstly, this book treats mostly continuous time dynamical systems, instead of its discrete counterpart, exhaustively treated

  7. Spiral Flow Separator

    Science.gov (United States)

    Robertson, Glen A.

    1993-01-01

    Proposed liquid-separating device relies on centrifugal force in liquid/liquid or liquid/solid mixture in spiral path. Operates in continuous flow at relatively high rates. Spiral tubes joined in sequence, with outlet tubes connected to joints. Cross-sectional areas of successive spiral tubes decreases by cross-sectional areas of outlet tubes. Centrifugal force pushes denser particles or liquids to outer edge of spiral, where removed from flow. Principle exploited to separate solids from wastewater, oil from fresh or salt water, or contaminants from salt water before evaporation. Also used to extract such valuable materials as precious metals from slurries.

  8. Mechanics of fluid flow

    CERN Document Server

    Basniev, Kaplan S; Chilingar, George V 0

    2012-01-01

    The mechanics of fluid flow is a fundamental engineering discipline explaining both natural phenomena and human-induced processes, and a thorough understanding of it is central to the operations of the oil and gas industry.  This book, written by some of the world's best-known and respected petroleum engineers, covers the concepts, theories, and applications of the mechanics of fluid flow for the veteran engineer working in the field and the student, alike.  It is a must-have for any engineer working in the oil and gas industry.

  9. International symposium on slurry flows

    International Nuclear Information System (INIS)

    This book presents the papers given at a conference on two-phase slurry flow. Topics considered at the conference included flow models, drag, flow rate, stresses in a fluid-solid mixture, kinetic models, the shear viscosity of dense-phase slurries at varying shear rates, the modeling of particulates based on the Markov process, fluid-particle flows in geothermal drilling applications, two-phase nozzle flow, laminar flow, centrifugal slurry pumps, slurry pipeline flow, and the beneficiation of coal by agglomeration during hydraulic transport

  10. Validation of an optical flow algorithm to measure blood flow waveforms in arteries using dynamic digital x-ray images

    Science.gov (United States)

    Rhode, Kawal; Lambrou, Tryphon; Hawkes, David J.; Hamilton, George; Seifalian, Alexander M.

    2000-06-01

    We have developed a weighted optical flow algorithm for the extraction of instantaneous blood velocity from dynamic digital x-ray images of blood vessels. We have carried out in- vitro validation of this technique. A pulsatile physiological blood flow circuit was constructed using sections of silicone tubing to simulate blood vessels with whole blood as the fluid. Instantaneous recording of flow from an electromagnetic flow meter (EMF) provided the gold standard measurement. Biplanar dynamic digital x-ray images of the blood vessel with injection of contrast medium were acquired at 25 fps using a PC frame capture card. Imaging of a Perspex calibration cube allowed 3D reconstruction of the vessel and determination of true dimensions. Blood flow waveforms were calculated off-line on a Sun workstation using the new algorithm. The correlation coefficient between instantaneous blood flow values obtained from the EMF and the x-ray method was r equals 0.871, n equals 1184, p less than 0.0001. The correlation coefficient for average blood flow was r equals 0.898, n equals 16, p less than 0.001. We have successfully demonstrated that our new algorithm can measure pulsatile blood flow in a vessel phantom. We aim to use this algorithm to measure blood flow clinically in patients undergoing vascular interventional procedures.

  11. The fluctuations of quadrangular flow

    CERN Document Server

    Giacalone, Giuliano; Noronha-Hostler, Jacquelyn; Ollitrault, Jean-Yves

    2016-01-01

    The ATLAS Collaboration has measured for the first time the fourth cumulant of quadrangular flow, $v_4\\{4\\}^4$. Unlike the fourth cumulants of elliptic and triangular flows, it presents a change of sign above 30\\% centrality. We show that this change of sign is predicted by event-by-event hydrodynamics. We argue that it results from the combined effects of a nonlinear hydrodynamic response, which couples quadrangular flow to elliptic flow, and elliptic flow fluctuations.

  12. Job flows and worker flows: a reappraisal - Job flows scaled down and only moderately linked to worker flows

    OpenAIRE

    Picart, C.

    2007-01-01

    Job flows (job creations and job destructions) and worker flows (hires and quits) are central to recent analysis of labor market. The scale of gross job flows (creations + destructions) compared to net job flows (creations - destructions) has a part in the renewal of Schumpeterian analysis. It is usually accepted that gross job flows are roughly of the same magnitude in such different countries as France and the USA. This study takes advantage of the possibility to follow employees for two ye...

  13. Lattice splitting under intermittent flows

    OpenAIRE

    Schläpfer, Markus; Trantopoulos, Konstantinos

    2010-01-01

    We study the splitting of regular square lattices subject to stochastic intermittent flows. Various flow patterns are produced by different groupings of the nodes, based on their random alternation between two possible states. The resulting flows on the lattices decrease with the number of groups according to a power law. By Monte Carlo simulations we reveal how the time span until the occurrence of a splitting depends on the flow patterns. Increasing the flow fluctuation frequency shortens t...

  14. Synthetic aperture tissue and flow ultrasound imaging

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav

    simultaneously at every emission, which makes it possible to average over a large number of lines. This makes stationary echo canceling easier and significantly improves the velocity estimates. Only 8 emissions per plane are necessary to create the color flow map. Scanning 12 cm in depth, up to 800 planes can be......This Ph.D. project was carried out at the Center for Fast Ultrasound Imaging, Technical University of Denmark. The goal was to improve existing imaging techniques in order to make them suitable for real-time three-dimensional ultrasound scanning. This dissertation focuses on the synthetic aperture...... and beamformation methods are adequate for the imaging modalities in clinical use - the B-mode imaging of tissue structures, and the color mapping of blood flow. The acquisition time, however, is too long, and these methods fail to perform real-time three-dimensional scans. The synthetic transmit...

  15. Nucleon flow and fragment flow in heavy ion reactions

    International Nuclear Information System (INIS)

    The collective flow of nucleons and that of fragments in the 12C+12C reaction below 150 MeV/nucleon are calculated with the antisymmetrized version of molecular dynamics combined with the statistical decay calculation. The density dependent Gogny force is used as the effective interaction. The calculated balance energy is about 100 MeV/nucleon, which is close to the observed value. Below the balance energy, the absolute value of the fragment flow is larger than that of nucleon flow, which is also in accordance with data. The dependence of the flow on the stochastic collision cross section and its origin are discussed. All the results are naturally understood by introducing the concept of two components of flow: the flow of dynamically emitted nucleons and the flow of the nuclear matter which contributes to both the flow of fragments and the flow of nucleons due to the statistical decay

  16. Up-flow and down-flow burnout

    International Nuclear Information System (INIS)

    The effects of buoyancy force on the burn-out phenomenon have been studied with Freon 12 at low mass flow-rates. The critical heat flow is higher in up-flow than in down-flow (up to 35%) and this difference depends on the flow patterns occurring along the tube. The main influence of the buoyancy force seems to be localized in subcooled and bubble flow regions. A correlation between crisis qualities in down-flow and in up-flow has been obtained for these parameter ranges: - specific mass flow-rate G, 100 + 1000 kg/m2s; pressure 0.25 < p/psub(cr) < 0.60; inlet quality -0.40 < Xsub(in) < + 0.20. (author)

  17. Is flow verification necessary

    International Nuclear Information System (INIS)

    Safeguards test statistics are used in an attempt to detect diversion of special nuclear material. Under assumptions concerning possible manipulation (falsification) of safeguards accounting data, the effects on the statistics due to diversion and data manipulation are described algebraically. A comprehensive set of statistics that is capable of detecting any diversion of material is defined in terms of the algebraic properties of the effects. When the assumptions exclude collusion between persons in two material balance areas, then three sets of accounting statistics are shown to be comprehensive. Two of the sets contain widely known accountancy statistics. One of them does not require physical flow verification - comparisons of operator and inspector data for receipts and shipments. The third set contains a single statistic which does not require physical flow verification. In addition to not requiring technically difficult and expensive flow verification, this single statistic has several advantages over other comprehensive sets of statistics. This algebraic approach as an alternative to flow verification for safeguards accountancy is discussed in this paper

  18. Quaternions and ideal flows

    International Nuclear Information System (INIS)

    After a review of some of the recent works by Holm and Gibbon on quaternions and their application to Lagrangian flows, particularly the incompressible Euler equations and the equations of ideal MHD, this paper investigates the compressible and relativistic Euler equations using these methods

  19. Let It Flow

    Institute of Scientific and Technical Information of China (English)

    Alphonce Shiundu

    2011-01-01

    @@ AFRICA'S Gold Coast, otherwise known as the Republic of Ghana, marked the first 100 days since its oil taps began running, on March 25, 2011.The oil in question flows from the country s offshore Iubilee oilfield, recognized by the stakeholders to be the largest oil discovery in West Africa in the last 10 to 15 years.

  20. US energy flow, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Borg, I.Y.; Briggs, C.K.

    1992-06-01

    Trends in energy consumption and assessment of energy sources are discussed. Specific topics discussed include: energy flow charts; comparison of energy use with 1990 and earlier years; supply and demand of fossil fuels (oils, natural gas, coal); electrical supply and demand; and nuclear power.

  1. Flow Injection Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1998-01-01

    Learning objectives:* To provide an introduction to automated assays* To describe the basic principles of FIA * To demonstrate the capabilities of FIA in relation to batch assays and conventional continuous flow systems* To show that FIA allows one to augment existing analytical techniques* To show...

  2. Probabilistic Load Flow

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Chen, Zhe; Bak-Jensen, Birgitte

    2008-01-01

    This paper reviews the development of the probabilistic load flow (PLF) techniques. Applications of the PLF techniques in different areas of power system steady-state analysis are also discussed. The purpose of the review is to identify different available PLF techniques and their corresponding...

  3. Freely flowing conversations

    DEFF Research Database (Denmark)

    Aakjær, Marie Kirstejn; Andrade, David; Dexters, Peter

    and in regards to rehabilitation efforts. In the context of prisons UDI is inspired by the complexity approach (Stacey 2005). We seek to facilitate freely flowing conversations between inmates, staff and managers – pushing the boundaries of existing norms, roles and beliefs. In the end however we rely...

  4. Flow on noisy terrains

    DEFF Research Database (Denmark)

    Tsirogiannis, Konstantinos; Haverkort, Herman

    2011-01-01

    Computing watersheds on triangulated terrain models in a robust manner is a difficult task as it is sensitive to noise that appears in the elevation values of the input. This is amplified by the existence of many very small watersheds (corresponding to spurious minima) that obscure the overall hy...... use a robust flow model together with exact arithmetic....

  5. Flow control using ferrofluids

    Science.gov (United States)

    Cornat, Francois; Beck, David; Jacobi, Ian; Stone, Howard

    2013-11-01

    A novel flow control technique is proposed which employs a ferrofluidic lubricant infused in a micro-patterned substrate as a ``morphing surface'' for control of wall-bounded flows. Traditionally, morphing surfaces produce dynamic changes in the curvature and roughness of solid substrates for active control of high Reynolds number flow features such as boundary layer separation and turbulent streaks. We show how these surface modifications can be achieved with a thin liquid layer in the presence of a normal magnetic field. By impregnating a chemically-treated, micro-patterned surface with a fluorinated ferrofluid, the fluid is maintained as a thin super-hydrophobic film and can be redistributed on the substrate by magnetic forces to dynamically reveal or conceal the underlying surface roughness. Moreover, the surface topography of the ferrofluid film itself can be modified to produce an enhanced roughness, beyond the scale of the underlying substrate pattern. Both types of ferrofluidic surface modifications are studied in micro- and macro- scale channels in order to assess the feasibility of flow modification at low to moderate Reynolds numbers.

  6. Flow of nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, H.G.; Doss, K.G.R.; Gustafsson, H.A.; Gutbrod, H.H.; Kampert, K.H.; Kolb, B.; Loehner, H.; Ludewigt, B.; Poskanzer, A.M.; Warwick, A.

    1985-08-01

    The systems Nb + Nb and Au + Au have been measured at different energies at the Bevalac with the Plastic Ball spectrometer. Distributions of the flow angles as a function of charged particle multiplicity are presented. Also shown is a transverse momentum analysis for 400 MeV per nucleon Nb + Nb. 25 refs., 5 figs., 1 tab.

  7. The Flow of Chemists

    Science.gov (United States)

    Education in Science, 1975

    1975-01-01

    Presents two notes regarding the article "The Flow of Chemists" published in the January issue of 'Education in Science' (61 page 21) related to declining numbers of chemistry students in higher education. Both writers suggest different syllabuses requiring less math and a better match of material to student ability and understanding. (EB)

  8. Sinuous flow in metals.

    Science.gov (United States)

    Yeung, Ho; Viswanathan, Koushik; Compton, Walter Dale; Chandrasekar, Srinivasan

    2015-08-11

    Annealed metals are surprisingly difficult to cut, involving high forces and an unusually thick "chip." This anomaly has long been explained, based on ex situ observations, using a model of smooth plastic flow with uniform shear to describe material removal by chip formation. Here we show that this phenomenon is actually the result of a fundamentally different collective deformation mode--sinuous flow. Using in situ imaging, we find that chip formation occurs via large-amplitude folding, triggered by surface undulations of a characteristic size. The resulting fold patterns resemble those observed in geophysics and complex fluids. Our observations establish sinuous flow as another mesoscopic deformation mode, alongside mechanisms such as kinking and shear banding. Additionally, by suppressing the triggering surface undulations, sinuous flow can be eliminated, resulting in a drastic reduction of cutting forces. We demonstrate this suppression quite simply by the application of common marking ink on the free surface of the workpiece material before the cutting. Alternatively, prehardening a thin surface layer of the workpiece material shows similar results. Besides obvious implications to industrial machining and surface generation processes, our results also help unify a number of disparate observations in the cutting of metals, including the so-called Rehbinder effect. PMID:26216980

  9. Clinical PET application

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Moo; Hong, Song W.; Choi, Chang W.; Yang, Seong Dae [Korea Cancer Center Hospital, Seoul (Korea)

    1997-12-01

    PET gives various methabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 250 cases of PET images were obtained, which resulted total income of 180,000,000 won. 50,000,000 won was deposited for the 1998 PET clinical research. Second year PET clinical research should be managed under unified project. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18}FDG in a day purchase of HPLC pump and {sup 68}Ga pin source which was delayed due to economic crisis, should be done early in 1998. (author). 2 figs., 3 tabs.

  10. Blood flow measurements during hemodialysis vascular access interventions - Catheter-based thermodilution or Doppler ultrasound?

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Hansen, Marc A; Schroeder, Torben V; Ladefoged, Søren D; Lönn, Lars

    2012-01-01

    Purpose: To test the clinical performance of catheter-based thermodilution and Doppler ultrasound of the feeding brachial artery for blood flow measurements during hemodialysis vascular access interventions.Methods: Thirty patients with arteriovenous fistulas who underwent 46 interventions had...

  11. Physics of Traffic Flow

    Science.gov (United States)

    Davis, L. C.

    2015-03-01

    The Texas A&M Transportation Institute estimated that traffic congestion cost the United States 121 billion in 2011 (the latest data available). The cost is due to wasted time and fuel. In addition to accidents and road construction, factors contributing to congestion include large demand, instability of high-density free flow and selfish behavior of drivers, which produces self-organized traffic bottlenecks. Extensive data collected on instrumented highways in various countries have led to a better understanding of traffic dynamics. From these measurements, Boris Kerner and colleagues developed a new theory called three-phase theory. They identified three major phases of flow observed in the data: free flow, synchronous flow and wide moving jams. The intermediate phase is called synchronous because vehicles in different lanes tend to have similar velocities. This congested phase, characterized by lower velocities yet modestly high throughput, frequently occurs near on-ramps and lane reductions. At present there are only two widely used methods of congestion mitigation: ramp metering and the display of current travel-time information to drivers. To find more effective methods to reduce congestion, researchers perform large-scale simulations using models based on the new theories. An algorithm has been proposed to realize Wardrop equilibria with real-time route information. Such equilibria have equal travel time on alternative routes between a given origin and destination. An active area of current research is the dynamics of connected vehicles, which communicate wirelessly with other vehicles and the surrounding infrastructure. These systems show great promise for improving traffic flow and safety.

  12. Ultrasensitive flow cytometric analyses

    Energy Technology Data Exchange (ETDEWEB)

    Jett, J.H.; Cram, L.S.; Keller, R.A.; Martin, J.C.; Saunders, G.C.; Sklar, L.A.; Steinkamp, J.A.

    1993-01-01

    New techniques and approaches to cellular analysis being developed at the Los Alamos National Flow Cytometry Resource can be divided into those that improve sensitivity and those that move the technology into new areas by refining existing approaches. An example of the first category is a flow cytometric system capable of measuring the phase shift of fluorescence emitted by fluorophors bound to cells is being assembled. This phase sensitive cytometer is be capable of quantifying fluorescence life time on a cell-by-cell basis as well as using the phase sensitive detection to separate fluorescence emissions that overlap spectrally but have different lifetimes. A Fourier transform flow cytometer capable of measuring the fluorescence emission spectrum of individual labeled cells at rates approaching several hundred per second is also in the new technology category. The current implementation is capable of resolving the visible region of the spectrum into 8 bands. With this instrument, it is possible to resolve the contributions of fluorophors with overlapping emission spectra and to determine the emission spectra of dyes such as calcium concentration indicators that are sensitive to the physiological environment. Flow cytometric techniques have been refined to the point that it is possible to detect individual fluorescent molecules in solution as they flow past a laser beam. This capability has lead to a rapid DNA sequencing project. The goal of the project is to develop a technique that is capable of sequencing long strands of DNA (40,000 kb) at a rate of between 100 and 1,000 bases per second.

  13. Reduced contralateral hemispheric flow measured by SPECT in cerebellar lesions

    DEFF Research Database (Denmark)

    Sönmezoğlu, K; Sperling, B; Henriksen, T; Tfelt-Hansen, P; Lassen, N A

    1993-01-01

    Four patients with clinical signs of cerebellar stroke were studied twice by SPECT using 99mTc-HMPAO as a tracer for cerebral blood flow (CBF). When first scanned 6 to 22 days after onset, all had a region of very low CBF in the symptomatic cerebellar hemisphere, and a mild to moderate CBF reduct...

  14. Cerebral blood flow measurements using electron beam computed tomography (EBT)

    International Nuclear Information System (INIS)

    In close collaboration with the participants of the TEMPUS-Project Nr. 11117 a new technical and theoretical approach was developed to estimate cerebral blood flow using i.v. applied contrast agent and evaluating the cerebral time density curves using EBT as imaging method. This new approach and first clinical results are described. (author)

  15. Marking out the clinical expert/clinical leader/clinical scholar: perspectives from nurses in the clinical arena

    OpenAIRE

    Mannix, Judy; Wilkes, Lesley; Jackson, Debra

    2013-01-01

    Background Clinical scholarship has been conceptualised and theorised in the nursing literature for over 30 years but no research has captured nurses’ clinicians’ views on how it differs or is the same as clinical expertise and clinical leadership. The aim of this study was to determine clinical nurses’ understanding of the differences and similarities between the clinical expert, clinical leader and clinical scholar. Methods A descriptive interpretative qualitative approach using semi-struct...

  16. A liquid crystal polymer membrane MEMS sensor for flow rate and flow direction sensing applications

    International Nuclear Information System (INIS)

    The paper reports the design, fabrication and experimental results of a liquid crystal polymer (LCP) membrane-based pressure sensor for flow rate and flow direction sensing applications. Elaborate experimental testing results demonstrating the sensors' performance as an airflow sensor have been illustrated and validated with theory. MEMS sensors using LCP as a membrane structural material show higher sensitivity and reliability over silicon counterparts. The developed device is highly robust for harsh environment applications such as atmospheric wind flow monitoring and underwater flow sensing. A simple, low-cost and repeatable fabrication scheme has been developed employing low temperatures. The main features of the sensor developed in this work are a LCP membrane with integrated thin film gold piezoresistors deposited on it. The sensor developed demonstrates a good sensitivity of 3.695 mV (ms−1)−1, large operating range (0.1 to >10 ms−1) and good accuracy in measuring airflow with an average error of only 3.6% full-scale in comparison with theory. Various feasible applications of the developed sensor have been demonstrated with experimental results. The sensor was tested for two other applications—in clinical diagnosis for breath rate, breath velocity monitoring, and in underwater applications for object detection by sensing near-field spatial flow pressure

  17. A multi-agent system for monitoring patient flow.

    Science.gov (United States)

    Rosati, Samanta; Tralli, Augusta; Balestra, Gabriella

    2013-01-01

    Patient flow within a healthcare facility may follow different and, sometimes, complicated paths. Each path phase is associated with the documentation of the activities carried out during it and may require the consultation of clinical guidelines, medical literature and the use of specific software and decision aid systems. In this study we present the design of a Patient Flow Management System (PFMS) based on Multi Agent Systems (MAS) methodology. System requirements were identified by means of process modeling tools and a MAS consisting of six agents was designed and is under construction. Its main goal is to support both the medical staff during the health care process and the hospital managers in assuring that all the required documentation is completed and available. Moreover, such a tool can be used for the assessment and comparison of different clinical pathways, in order to identify possible improvementsand the optimum patient flow. PMID:23920718

  18. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... experimental drug, therapy, medical device, lifestyle change, or test will help treat, find, or prevent a disease. A clinical trial may compare experimental products or tests to those already available or may compare existing ...

  19. Clinical specular microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hirst, L.W.; Laing, R.A.

    1987-01-01

    This book provides the general ophthalmologist with a guide to the clinical applications of specular microscopy. Important material is included on laser injury, cataract surgery, corneal transplants, glaucoma, uveitis, and trauma.

  20. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... that could identify a disease in its early stages. Usually, trial participants must show signs of the ... Trials Clinical trials of drugs are usually described based on their phase. The U.S. Food and Drug ...

  1. Leprosy neuropathy: clinical presentations.

    Science.gov (United States)

    Nascimento, Osvaldo J M

    2013-09-01

    Leprosy is a chronic infectious peripheral neuropathy caused by Mycobacterium leprae. The different clinical presentations of the disease are determined by the quality of the host immune response. Early detection of leprosy and treatment by multidrug therapy are the most important steps in preventing deformity and disability. Thus the early recognition of the clinical leprosy presentation is essential. Mononeuritis, mononeuritis multiplex (MM), polyneuritis (MM summation) are the most frequent. The frequent anesthetic skin lesions are absent in the pure neuritic leprosy presentation form. Isolated peripheral nerve involvement is common, including the cranial ones. Arthritic presentation is occasionally seen, usually misdiagnosed as rheumatoid arthritis. Attention should be given to autonomic dysfunctions in leprosy. There are clinical presentations with severe neuropathic pain - painful small-fiber neuropathy. Leprous late-onset neuropathy (LLON) clinical presentation should be considered facing a patient who develop an inflammatory neuropathy many years after a previous skin leprosy treatment. PMID:24141500

  2. Clinical Trial Basics

    Science.gov (United States)

    ... Human Services Search the NIH Website NIH Employee Intranet Staff Directory En Español Site Menu Home Health ... am thinking about participating? Xsandra/iStock Risks and benefits Clinical trials involve risks, just as routine medical ...

  3. Fidelity in clinical simulation

    DEFF Research Database (Denmark)

    Jensen, Sanne; Nøhr, Christian; Rasmussen, Stine Loft

    2013-01-01

    Clinical simulation may be used to identify user needs for context sensitive functionalities in e-Health. The objective with this paper is to describe how user requirements and use cases in a large EHR-platform procurement may be validated by clinical simulation using a very low-fidelity prototype...... without any existing test data. Instead of using test scenarios and use cases, the healthcare professionals who are participating in the clinical simulation are generating both scenario and patient data themselves. We found that this approach allows for an imaginative discussion, not restricted by known...... functionalities and limitations, of the ideal EHR-platform. Subsequently, we discuss benefits and challenges of using an extremely low fidelity environment and discuss the degree of fidelity necessary for conducting clinical simulation....

  4. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... was provided by the National Library of Medicine Topic last reviewed: December 2013 For an enhanced version of this page please turn Javascript on. Participating in Clinical Trials ...

  5. Clinical Case Registries (CCR)

    Data.gov (United States)

    Department of Veterans Affairs — The Clinical Case Registries (CCR) replaced the former Immunology Case Registry and the Hepatitis C Case Registry with local and national databases. The CCR:HIV and...

  6. ClinicalTrials.gov

    Data.gov (United States)

    U.S. Department of Health & Human Services — Provides patients, family members, health care professionals, and members of the public easy access to information on clinical trials for a wide range of diseases...

  7. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... Learn More Participating in Clinical Trials Videos quiz yourself MedlinePlus for More Information National Institute on Aging Related Topics Talking with Your Doctor Taking Medicines The information in ...

  8. Towards sustainable clinical trials

    OpenAIRE

    Group, Sustainable Trials Study

    2007-01-01

    Currently, few researchers think about the carbon footprint of their trial. The Sustainable Trials Study Group reports that clinical trials are carbon intensive and suggests ways to make them more efficient

  9. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... Clinical Trials Videos quiz yourself MedlinePlus for More Information National Institute on Aging Related Topics Talking with Your Doctor Taking Medicines The information in this topic was provided by the National ...

  10. Consolidated Clinical Microbiology Laboratories

    OpenAIRE

    Sautter, Robert L.; Thomson, Richard B.

    2014-01-01

    The manner in which medical care is reimbursed in the United States has resulted in significant consolidation in the U.S. health care system. One of the consequences of this has been the development of centralized clinical microbiology laboratories that provide services to patients receiving care in multiple off-site, often remote, locations. Microbiology specimens are unique among clinical specimens in that optimal analysis may require the maintenance of viable organisms. Centralized laborat...

  11. Urine in clinical proteomics.

    OpenAIRE

    Decramer, Stéphane; Gonzalez de Peredo, Anne; Breuil, Benjamin; Mischak, Harald; Monsarrat, Bernard; Bascands, Jean-Loup; Schanstra, Joost P

    2008-01-01

    Urine has become one of the most attractive biofluids in clinical proteomics as it can be obtained non-invasively in large quantities and is stable compared with other biofluids. The urinary proteome has been studied by almost any proteomics technology, but mass spectrometry-based urinary protein and peptide profiling has emerged as most suitable for clinical application. After a period of descriptive urinary proteomics the field is moving out of the discovery phase into an era of validation ...

  12. Statistics in clinical practice

    CERN Document Server

    Coggon, David

    2002-01-01

    These days a basic knowledge of statistics is essential for good clinical practice, which presents a daunting challenge to health professionals who are not mathematically inclined. This book is aimed at clinicians and students who view statistics as a necessary evil. It covers the summary and presentation of data as might be required for a clinical meeting, audit or the planning of services, and explains how to interpret the p-values and confidence intervals that are reported in medical and scientific journals.

  13. Clinical careers film.

    Science.gov (United States)

    2015-09-01

    Those interested in developing clinical academic careers might be interested in a short animated film by Health Education England (HEE) and the National Institute for Health Research. The three-minute film, a frame from which is shown below, describes the sort of opportunities that are on offer to all professionals as part of the HEE's clinical academic careers framework. You can view the film on YouTube at tinyurl.com/pelb95c. PMID:26309005

  14. The clinical nanomedicine handbook

    CERN Document Server

    Brenner, Sara

    2013-01-01

    Designed to foster a stronger awareness and exploration of the subject by practicing clinicians, medical researchers and scientists, The Clinical Nanomedicine Handbook discusses the integration of nanotechnology, biology, and medicine from a clinical point of view. The book highlights relevant research and applications by specialty; it examines nanotechnology in depth, and the potential to solve medical problems. It also increases literacy in nanotechnology, and allows for more effective communication and collaboration between disciplines. Details worldwide developments in nanomedicine Provide

  15. Pediatric Anthrax Clinical Management

    OpenAIRE

    Bradley, John S.; Peacock, Georgina; Krug, Steven E.; Bower, William A.; Cohn, Amanda C.; Meaney-Delman, Dana; Pavia, Andrew T.

    2014-01-01

    Anthrax is a zoonotic disease caused by Bacillus anthracis, which has multiple routes of infection in humans, manifesting in different initial presentations of disease. Because B anthracis has the potential to be used as a biological weapon and can rapidly progress to systemic anthrax with high mortality in those who are exposed and untreated, clinical guidance that can be quickly implemented must be in place before any intentional release of the agent. This document provides clinical guidanc...

  16. Blood Pump Development Using Rocket Engine Flow Simulation Technology

    Science.gov (United States)

    Kwak, Dochan; Kiris, Cetin

    2001-01-01

    This paper reports the progress made towards developing complete blood flow simulation capability in humans, especially in the presence of artificial devices such as valves and ventricular assist devices. Devices modeling poses unique challenges different from computing the blood flow in natural hearts and arteries. There are many elements needed to quantify the flow in these devices such as flow solvers, geometry modeling including flexible walls, moving boundary procedures and physiological characterization of blood. As a first step, computational technology developed for aerospace applications was extended to the analysis and development of a ventricular assist device (VAD), i.e., a blood pump. The blood flow in a VAD is practically incompressible and Newtonian, and thus an incompressible Navier-Stokes solution procedure can be applied. A primitive variable formulation is used in conjunction with the overset grid approach to handle complex moving geometry. The primary purpose of developing the incompressible flow analysis capability was to quantify the flow in advanced turbopump for space propulsion system. The same procedure has been extended to the development of NASA-DeBakey VAD that is based on an axial blood pump. Due to massive computing requirements, high-end computing is necessary for simulating three-dimensional flow in these pumps. Computational, experimental, and clinical results are presented.

  17. Clinical Studies with Epothilones

    Science.gov (United States)

    Altmann, Karl-Heinz

    As indicated in previous chapters, epothilone research so far has delivered seven new chemical entities that have been advanced to clinical trials in humans (Fig. 1). However, the amount of clinical data publicly available at this time strongly varies between individual compounds, depending on their development stage, but also on the general publication policy of the developing company. The compound that has been most comprehensively characterized in the clinical literature is ixabepilone (BMS-247550), for which trial results have been described in a number of articles in peer-reviewed journals and which has been granted FDA approval for two clinical indications on Oct. 16, 2007. For all other compounds, most of the information on clinical trials is available only in abstract form. In all these cases it remains uncertain, whether the content of these abstracts fully reflects the content of the subsequent (poster or oral) presentations at the corresponding meeting; in fact, it seems likely that additional data will have been included in the actual meeting presentations that may not have been available at the time of abstract submission. As this is unknown to the author, such additional information cannot be considered in this chapter, which is solely based on information documented in accessible abstracts or journal publications. It should also be kept in mind that the interpretation of data from ongoing clinical trials or forward looking statements based on data from completed trials are always preliminary in character.

  18. Clinical toxinology specialty training.

    Science.gov (United States)

    White, Julian

    2013-07-01

    Clinical toxinology is the medical discipline dealing with the diagnosis, treatment and prevention of toxin diseases caused by exposure to venomous animals and poisonous animals, plants and mushrooms. Currently there is no national or international organisation accrediting or training doctors in this discipline, but the role of the IST in this area is the subject of a recently approved revised Constitution. A few courses covering some aspects of clinical toxinology exist, either with limited curricula, or with only a minor clinical focus, or with a very regional, non-global focus. The only comprehensive clinical toxinology course is the one provided in Adelaide, Australia, running regularly since 1997. This course may form the nucleus from which IST can develop a global accredited training scheme in clinical toxinology. Such a scheme will require input from diverse global regions and will be far more comprehensive and over a much longer time than the current Short Course, though may incorporate the Short Course in some way, or a derivative of it. Accreditation of medical expertise in clinical toxinology will be required at the national level and this might be accomplished by the IST working with existing national medical specialty organisations and governments, with the IST supervising the training and accreditation requirements and the national organisations providing the framework for registration of medical expertise at the local level. PMID:23524067

  19. Fundamentals of clinical trials

    CERN Document Server

    Friedman, Lawrence M; DeMets, David L; Reboussin, David M; Granger, Christopher B

    2015-01-01

    This is the fifth edition of a very successful textbook on clinical trials methodology, written by recognized leaders who have long and extensive experience in all areas of clinical trials. The three authors of the first four editions have been joined by two others who add great expertise.  Most chapters have been revised considerably from the fourth edition.  A chapter on regulatory issues has been included and the chapter on data monitoring has been split into two and expanded.  Many contemporary clinical trial examples have been added.  There is much new material on adverse events, adherence, issues in analysis, electronic data, data sharing, and international trials.  This book is intended for the clinical researcher who is interested in designing a clinical trial and developing a protocol. It is also of value to researchers and practitioners who must critically evaluate the literature of published clinical trials and assess the merits of each trial and the implications for the care and treatment of ...

  20. Clinical dosimetry using mosfets

    International Nuclear Information System (INIS)

    Purpose: The use of metal oxide-silicon field effect transistors (MOSFETs) as clinical dosimeters is demonstrated for a number of patients with targets at different clinical sites. Methods and Materials: Commercially available MOSFETs were characterized for energy response, angular dependency of response, and effect of accumulated dose on sensitivity and some inherent properties of MOSFETs. The doses determined both by thermoluminescence dosimetry (TLD) and MOSFETs in clinical situation were evaluated and compared to expected doses determined by calculation. Results: It was observed that a standard calibration of 0.01 Gy/mV gave MOSFET determined doses which agreed with expected doses to within 5% at the 95% confidence limit for photon beams from 6 to 25 MV and electron beams from 5 to 14 MeV. An energy-dependent variation in response of up to 28% was observed between two orientations of a MOSFET. The MOSFET doses compared very well with the doses estimated by TLDs, and the patients tolerated MOSFETs very well. A standard deviation of 3.9% between expected dose and MOSFET determined dose was observed, while for TLDs the standard deviation was 5.1%. The advantages and disadvantages of using MOSFETs for clinical dosimetry are discussed in detail. Conclusion: It was concluded that MOSFETs can be used as clinical dosimeters and can be a good alternative to TLDs. However, they have limitations under certain clinical situations

  1. Directional synthetic aperture flow imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Nikolov, Svetoslav

    2004-01-01

    A method for flow estimation using synthetic aperture imaging and focusing along the flow direction is presented. The method can find the correct velocity magnitude for any flow angle and full color flow images can be measured using only 32 to 128 pulse emissions. The approach uses spherical wave...... emissions using a number of defocused elements and a linear frequency modulated pulse (chirp) to improve the signal-to-noise ratio. The received signals are dynamically focused along the flow direction and these signals are used in a cross-correlation estimator for finding the velocity magnitude. The flow...

  2. Flow networks analysis and optimization of repairable flow networks, networks with disturbed flows, static flow networks and reliability networks

    CERN Document Server

    Todinov, Michael T

    2013-01-01

    Repairable flow networks are a new area of research, which analyzes the repair and flow disruption caused by failures of components in static flow networks. This book addresses a gap in current network research by developing the theory, algorithms and applications related to repairable flow networks and networks with disturbed flows. The theoretical results presented in the book lay the foundations of a new generation of ultra-fast algorithms for optimizing the flow in networks after failures or congestion, and the high computational speed creates the powerful possibility of optimal control

  3. Intracranial flow of cerebrospinal fluid

    International Nuclear Information System (INIS)

    This paper reports cerebrospinal fluid (CSF) flow in the third ventricle, aqueduct, fourth ventricle, basal cisterns, and subarachnoid spaces at the cervical-medullary junction evaluated in 25 patients and 10 normal volunteers. Information was acquired on 1.5-T magnet with a cardiac-gated, single-section, gradient-echo technique and displayed via closed-loop cine imaging. Qualitative assessment of flow patterns via magnitude reconstruction was correlated with quantitative data generated via phase reconstruction. Normal patterns of CSF flow were established. Pathologic changes involving these pathways altered the flow patterns, either causing increased turbulence and flow of CSF or decreasing the expected flow

  4. Self-Organized Network Flows

    CERN Document Server

    Helbing, D; Lämmer, S; Helbing, Dirk; Siegmeier, Jan; L\\"{a}mmer, Stefan

    2007-01-01

    A model for traffic flow in street networks or material flows in supply networks is presented, that takes into account the conservation of cars or materials and other significant features of traffic flows such as jam formation, spillovers, and load-dependent transportation times. Furthermore, conflicts or coordination problems of intersecting or merging flows are considered as well. Making assumptions regarding the permeability of the intersection as a function of the conflicting flows and the queue lengths, we find self-organized oscillations in the flows similar to the operation of traffic lights.

  5. FLOW-Methode - Methodenbeschreibung zur Anwendung von FLOW

    CERN Document Server

    Stapel, Kai

    2012-01-01

    Information of many kinds is flowing in software projects and organizations. Requirements have to flow from the customer to the developers. Testers need to know the requirements as well. Boundary conditions and design decisions have to be at the right place at the right time. Information flow analysis with FLOW facilitates modeling of mode and route of the flow of information and experience independent of the development methodology. Experience often acts as a control factor, because experienced developers can process and route information more efficiently. Therefore, experience needs to be at the right place at the right time, too. However, most valuable experiences never get documented. Since information and experience is flowing in agile as well as in traditional environments, the FLOW method does not distinguish between agile and traditional, but only between how the flows are shaped. ---- In Softwareprojekten flie{\\ss}en vielerlei Informationen. Anforderungen m\\"ussen vom Kunden zu den Entwicklern gelang...

  6. Children and Clinical Studies: Why Clinical Studies Are Important

    Medline Plus

    Full Text Available ... Systematic Evidence Reviews & Clinical Practice Guidelines Resources Continuing Education Researchers Funding Training & Career Development Division of Intramural Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & ...

  7. An orographic flow diagramme

    Science.gov (United States)

    Opsanger Jonassen, Marius; Ólafsson, Haraldur; Ágústsson, Hálfdán

    2016-04-01

    Motivated by the need to relate some key features of atmospheric flow over mountains to the elevation of the inversion and wind speed, many numerical experiments are made in order to create a diagramme a la Vosper (2004). The simulations are carried out with the WRF model and stationary boundary-conditions. A neutral boundary-layer is capped by a 10K inversion, of which the height varies. The mountain is 1 km high and the incoming winds are 10,15 or 20 m/s. The surface has zo=0.1m. Vortices, vortex shedding, lee waves and hydraulic jump are detected and related to values of the height of the inversion and the Froude number. Cases of real flow are compared to the idealized results.

  8. Slow viscous flow

    CERN Document Server

    Langlois, William E

    2014-01-01

    Leonardo wrote, 'Mechanics is the paradise of the mathematical sciences, because by means of it one comes to the fruits of mathematics' ; replace 'Mechanics' by 'Fluid mechanics' and here we are." -    from the Preface to the Second Edition Although the exponential growth of computer power has advanced the importance of simulations and visualization tools for elaborating new models, designs and technologies, the discipline of fluid mechanics is still large, and turbulence in flows remains a challenging problem in classical physics. Like its predecessor, the revised and expanded Second Edition of this book addresses the basic principles of fluid mechanics and solves fluid flow problems where viscous effects are the dominant physical phenomena. Much progress has occurred in the nearly half a century that has passed since the edition of 1964. As predicted, aspects of hydrodynamics once considered offbeat have risen to importance. For example, the authors have worked on problems where variations in viscosity a...

  9. Fracture flow code

    International Nuclear Information System (INIS)

    The hydrology of the SCV site will be modelled utilizing discrete fracture flow models. These models are complex, and can not be fully cerified by comparison to analytical solutions. The best approach for verification of these codes is therefore cross-verification between different codes. This is complicated by the variation in assumptions and solution techniques utilized in different codes. Cross-verification procedures are defined which allow comparison of the codes developed by Harwell Laboratory, Lawrence Berkeley Laboratory, and Golder Associates Inc. Six cross-verification datasets are defined for deterministic and stochastic verification of geometric and flow features of the codes. Additional datasets for verification of transport features will be documented in a future report. (13 figs., 7 tabs., 10 refs.) (authors)

  10. Flows in Kasei

    Science.gov (United States)

    2005-01-01

    28 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows flow materials-on the east/right side of the image-that have come in among a suite of sharp ridges and grooves on the floor of the vast Kasei Valles system. The ridges and grooves are much older and are believed to be the result of a giant, catastrophic flood. The flows might have been mud or lava that ran part way down the ancient valley at a later date. Location near: 16.7oN, 76.5oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  11. Structural power flow measurement

    Energy Technology Data Exchange (ETDEWEB)

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  12. Hydrodynamics and Flow

    CERN Document Server

    Hirano, Tetsufumi; Bilandzic, Ante

    2008-01-01

    In this lecture note, we present several topics on relativistic hydrodynamics and its application to relativistic heavy ion collisions. In the first part we give a brief introduction to relativistic hydrodynamics in the context of heavy ion collisions. In the second part we present the formalism and some fundamental aspects of relativistic ideal and viscous hydrodynamics. In the third part, we start with some basic checks of the fundamental observables followed by discussion of collective flow, in particular elliptic flow, which is one of the most exciting phenomenon in heavy ion collisions at relativistic energies. Next we discuss how to formulate the hydrodynamic model to describe dynamics of heavy ion collisions. Finally, we conclude the third part of the lecture note by showing some results from ideal hydrodynamic calculations and by comparing them with the experimental data.

  13. Clinical evaluation of contemporary oxygenators.

    Science.gov (United States)

    Stanzel, Roger D P; Henderson, Mark

    2016-01-01

    Advances in cardiopulmonary bypass equipment have played a critical role in improving outcomes for cardiac surgery patients. Recent advancements include reduced priming volumes, biocompatible coatings and gaseous microemboli handling, as well as the incorporation of an arterial filter into the oxygenator.The purpose of this study was to conduct a comprehensive clinical evaluation of adult oxygenators on the market. Oxygenators assessed included the Sorin Synthesis(®) (n = 30), the Sorin Inspire 6F(®) (n = 10) and Inspire 8F(®) (n = 30), the Terumo FX15(®) (n = 13) and FX25(®) (n = 30), the Maquet Quadrox-i(®) (n = 30) and the Medtronic Fusion(®) (n = 30). Parameters assessed included functional prime volumes, gas exchange, pressure gradients and the effects on patient hematology.The Synthesis had the largest functional prime volume (1426 ml), the FX15 the lowest (956 ml). The Inspire 6F, 8F and Fusion had the greatest O2 transfer. The Sorin oxygenators required the lowest sweep gas flows to obtain a PaCO2 of 40 mmHg. The Sorin oxygenators had the largest pressure gradients. While no differences were observed for hemoglobin and platelet levels post cross-clamp removal, the Sorin Synthesis and Inspire 8F had the largest increases in white blood cell (WBC) counts (122% and 141% of baseline, respectively) and neutrophils (162% and 185% of baseline, respectively).The data demonstrate that no single product is superior in all aspects. The choice of ideal oxygenator depends on the aspect(s) of oxygenator performance the perfusion team believes most clinically acceptable based on available data. PMID:26407816

  14. Discrete Morse flow for Ricci flow and Porous Media equation

    CERN Document Server

    Ma, Li

    2012-01-01

    In this paper, we study the discrete Morse flow for the Ricci flow on football, which is the 2-sphere with removed north and south poles and with the metric $g_0$ of constant scalar curvature, and and for Porous media equation on a bounded regular domain in the plane. We show that with a suitable assumption about $g(0)$ we have a weak approximated discrete Morse flow for the approximated Ricci flow and Porous media equation on any time intervals.

  15. Gaseous Flows in Galaxies

    OpenAIRE

    Combes, F.

    2007-01-01

    The gas component plays a major role in the dynamics of spiral galaxies, because of its dissipative character, and its ability to exchange angular momentum with stars in the disk. Due to its small velocity dispersion, it triggers gravitational instabilities, and the corresponding non-axisymmetric patterns produce gravity torques, which mediate these angular momentum exchanges. When a srong bar pattern develops with the same pattern speed all over the disk, only gas inside corotation can flow ...

  16. Divergent flow isoelectric focusing

    Czech Academy of Sciences Publication Activity Database

    Šlais, Karel

    2008-01-01

    Roč. 29, č. 12 (2008), s. 2451-2457. ISSN 0173-0835 R&D Projects: GA AV ČR IAAX00310701; GA ČR GA203/06/1179 Institutional research plan: CEZ:AV0Z40310501 Keywords : isoelectric focusing * divergent flow * pI markers Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.509, year: 2008

  17. Divergent flow isoelectric focusing

    Czech Academy of Sciences Publication Activity Database

    Šlais, Karel

    Budapest: Hungarian Society for Separation Sciences, 2007. s. 45. ISBN 978-963-06-2925-6. [Balaton Symposium on High-Performance /7./. 05.09.2007-07.09.2007, Siofok] R&D Projects: GA AV ČR IAAX00310701; GA ČR GA203/06/1179 Institutional research plan: CEZ:AV0Z40310501 Keywords : isoelectric focusing * divergent flow * pI markers Subject RIV: CB - Analytical Chemistry, Separation

  18. Worker Flows in Russia

    OpenAIRE

    Grogan, Louise

    2000-01-01

    This paper investigates worker flows in Russia. Information onelapsed durationsof job tenure from the 1994-1996 Russian Longitudinal MonitoringSurvey (RLMS)and fromretrospective work history responses to the Institute for LaborRelationsResearch (ISITO) 1998 household survey is used. Competing risksmodels fordurations of job tenure with multiple destination states areestimated. Patternsof transitions between sectors and to non-employment are identifiedfordifferent demographic groups. Rates of ...

  19. TEP process flow diagram

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, R Scott [Los Alamos National Laboratory; Carlson, Bryan [Los Alamos National Laboratory; Coons, James [Los Alamos National Laboratory; Kubic, William [Los Alamos National Laboratory

    2008-01-01

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  20. Flow og fordybelse

    DEFF Research Database (Denmark)

    Andersen, Frans Ørsted

    2010-01-01

    Artiklen handler om flow og fordybelse i et nyt tværfagligt / naturfagligt undervisningskoncept, "Overvågningens dilemma", til brug i folkeskolens 7.-9.kl. og på gymnasiale uddannelser. Konceptet sætter fokus på den overvågning der foregår og er mulig i nutidens IT og hi-tec samfund og der arbejdes...

  1. Kerr black string flow

    Directory of Open Access Journals (Sweden)

    Meng Sun

    2015-08-01

    Full Text Available We give a general illumination of a rotating black string falling into a rotating horizon in dimension D=5. It is a configuration of one smooth intersection between these two objects when the spacetime is axisymmetric and in the limit that the thickness of the black hole is much larger than the thickness of the black string. Following this configuration, we further extend them to the rotating and charged flows.

  2. Cash-Flow Tax

    OpenAIRE

    Parthasarathi Shome; Christian Schutte

    1993-01-01

    The cash-flow tax has been proposed as an alternative to corporate income tax on grounds of clarity and simplicity in defining the tax base in the face of widespread departures from the comprehensive income tax in actual practice. Variants of the tax, with their advantages and disadvantages, demonstrate that it would require careful design. Simplicity is not an obvious property because of expectable administration problems related to tax avoidance and evasion through transfer pricing; to infl...

  3. Intelligent flow friction estimation

    OpenAIRE

    Dejan Brkić; Žarko Ćojbašić

    2016-01-01

    Nowadays, the Colebrook equation is used as a mostly accepted relation for the calculation of fluid flow friction factor. However, the Colebrook equation is implicit with respect to the friction factor (λ). In the present study, a noniterative approach using Artificial Neural Network (ANN) was developed to calculate the friction factor. To configure the ANN model, the input parameters of the Reynolds Number (Re) and the relative roughness of pipe (ε/D) were transformed to logarithmic scales. ...

  4. TEP process flow diagram

    International Nuclear Information System (INIS)

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  5. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    International Nuclear Information System (INIS)

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  6. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  7. Vortex shedding flow meter performance at high flow velocities

    Science.gov (United States)

    Siegwarth, J. D.

    1986-01-01

    In some of the ducts of the Space Shuttle Main Engine (SSME), the maximum liquid oxygen flow velocities approach 10 times those at which liquid flow measurements are normally made. The hydrogen gas flow velocities in other ducts exceed the maximum for gas flow measurement by more than a factor of 3. The results presented here show from water flow tests that vortex shedding flow meters of the appropriate design can measure water flow to velocities in excess of 55 m/s, which is a Reynolds number of about 2 million. Air flow tests have shown that the same meter can measure flow to a Reynolds number of at least 22 million. Vortex shedding meters were installed in two of the SSME ducts and tested with water flow. Narrow spectrum lines were obtained and the meter output frequencies were proportional to flow to + or - 0.5% or better over the test range with no flow conditioning, even though the ducts had multiple bends preceeding the meter location. Meters with the shedding elements only partially spanning the pipe and some meters with ring shaped shedding elements were also tested.

  8. Influence of the mean flow on zonal flow generation

    OpenAIRE

    Lashkin, V. M.

    2008-01-01

    Excitation of zonal flow by the modulational instability in the presence of mean shear flow is considered. It is shown that the small amplitude mean flow favours the modulational instability, increasing the growth rate, whereas sufficiently strong mean shear significantly reduces the instability growth rate.

  9. The weak 3-flow conjecture and the weak circular flow

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2012-01-01

    -connectivity 8 suffices. This implies the weak 3-flow conjecture proposed in 1988 by Jaeger (a natural weakening of Tutteʼs 3-flow conjecture which is still open) and also a weakened version of the more general circular flow conjecture proposed by Jaeger in 1982. It also implies the tree-decomposition conjecture...

  10. Computerised triage in a prostate assessment clinic.

    Science.gov (United States)

    Rajkumar, G N; Small, D R; Conn, I G

    2004-01-01

    An MS Office package has been developed to score IPSS, take a patient history, compare flows with nomograms and decide on interim management. This is based on these scores, residual volume and laboratory results. A clearly formatted GP letter is produced. The patient uses a touch screen to answer questions on the IPSS and other medical history. These questions and responses are stored in Excel spread sheets. Clinic staff then enter results of flow studies, urinalysis, U&E and PSA. Excel Visual Basic creates a detailed printout for the notes and the MS Office mail merge facility creates a summary printout, which also serves as a letter to the GP. Excel allows embedding of formulae and program code to implement the rules for management. Based on these rules, the program either generates a request for an urgent appointment in the clinic or recommends the use of either an alpha blocker (if not contraindicated by medical history) or 5 alpha reductase inhibitors in the interim period before they are reviewed in clinic. A total of 139 patients have been seen and the computer decisions compared with those of a consultant urologist. Agreement was found in 106, disagreement in 33. However, 21 of the 33 involved computer oversensitivity to flow results. We do not anticipate difficulty improving this and are investigating using an artificial neural network. Of the other 12 patients, the urologist departed from the fixed rules for IPSS, creatinine, PSA and residual urine when only one variable was slightly abnormal. To conclude, this novel user-friendly system shows great potential in the management of prostate outpatients. Some tuning is needed, with particular respect to uroflow results. PMID:15175663

  11. Clinical significance of microembolus detection by transcranial Doppler sonography in cardiovascular clinical conditions.

    Science.gov (United States)

    Hudorović, Narcis

    2006-01-01

    Transcranial Doppler can detect microembolic signals, which are characterized by unidirectional high intensity increase, short duration, and random occurrence, producing a "whistling" sound. Microembolic signals have been proven to represent solid or gaseous particles within the blood flow. Microemboli have been detected in a number of clinical cardiovascular settings: carotid artery stenosis, aortic arch plaques, atrial fibrillation, myocardial infarction, prosthetic heart valves, patent foramen ovale, valvular stenosis, during invasive procedures (angiography, percutaneous transluminal angioplasty) and surgery (carotid, cardiopulmonary bypass). Despite numerous studies performed so far, clinical significance of microembolic signals is still unclear. This article provides an overview of the development and current state of technical and clinical aspects of microembolus detection. PMID:17462357

  12. Low-cost laser speckle contrast imaging of blood flow using a webcam

    OpenAIRE

    Richards, Lisa M.; Kazmi, S. M. Shams; Davis, Janel L.; Olin, Katherine E.; Dunn, Andrew K.

    2013-01-01

    Laser speckle contrast imaging has become a widely used tool for dynamic imaging of blood flow, both in animal models and in the clinic. Typically, laser speckle contrast imaging is performed using scientific-grade instrumentation. However, due to recent advances in camera technology, these expensive components may not be necessary to produce accurate images. In this paper, we demonstrate that a consumer-grade webcam can be used to visualize changes in flow, both in a microfluidic flow phanto...

  13. Analysis of tidal expiratory flow pattern in the assessment of histamine-induced bronchoconstriction.

    OpenAIRE

    Morris, M. J.; Madgwick, R. G.; Lane, D. J.

    1995-01-01

    BACKGROUND--There are times in clinical practice when it would be useful to be able to assess the severity of airways obstruction from tidal breathing. Three indices of airways obstruction derived from analysis of resting tidal expiratory flow have previously been described: (1) Tme/TE = time to reach maximum expiratory flow/expiratory time; (2) Krs = decay constant of exponential fitted to tidal expiratory flow versus time curve; and (3) EV = extrapolated volume--that is, area under the curv...

  14. Virtual Flow Simulator

    Energy Technology Data Exchange (ETDEWEB)

    2015-10-05

    Virtual Flow Simulator (VFS) is a state-of-the-art computational fluid mechanics (CFD) package that is capable of simulating multi-physics/multi-phase flows with the most advanced turbulence models (RANS, LES) over complex terrains. The flow solver is based on the Curvilinear Immersed Boundary (CURVIB) method to handle geometrically complex and moving domains. Different modules of the VFS package can provide different simulation capabilities for specific applications ranging from the fluid-structure interaction (FSI) of solid and deformable bodies, the two-phase free surface flow solver based on the level set method for ocean waves, sediment transport models in rivers and the large-scale models of wind farms based on actuator lines and surfaces. All numerical features of VFS package have been validated with known analytical and experimental data as reported in the related journal articles. VFS package is suitable for a broad range of engineering applications within different industries. VFS has been used in different projects with applications in wind and hydrokinetic energy, offshore and near-shore ocean studies, cardiovascular and biological flows, and natural streams and river morphodynamics. Over the last decade, the development of VFS has been supported and assisted with the help of various United States companies and federal agencies that are listed in the sponsor lists. In this version, VFS-Wind contains all the necessary modeling tools for wind energy applications, including land-based and offshore wind farms. VFS is highly scalable to run on either desktop computers or high performance clusters (up to 16,000 CPUs). This released version comes with a detailed user’s manual and a set of case studies designed to facilitate the learning of the various aspects of the code in a comprehensive manner. The included documentation and support material has been elaborated in a collaboration effort with Sandia National Labs under the contract DE-EE0005482. The VFS

  15. A Cryogenic Flow Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on the success of the phase I effort, Advanced Technologies Group, Inc. proposes the development of a Cryogenic Flow Sensor (CFS) for determining mass flow of...

  16. Asymmetric reactions in continuous flow

    Directory of Open Access Journals (Sweden)

    Xiao Yin Mak

    2009-04-01

    Full Text Available An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed.

  17. Characteristics of Solar Meridional Flows

    Science.gov (United States)

    Basu, Sarbani; Antia, H. M.

    2011-01-01

    We have done a ring-diagram analysis of MDI full-disc data to determine the properties of solar meridional flow in the outer 2% of the Sun over the solar cycle 23. The meridional flows show a migrating pattern with higher-velocity flows migrating toward the equator as activity increases. Additionally, we find that the migrating pattern of the meridional flow matches those of the sunspot butterfly diagram and the zonal flows in the shallow layers. A Legendre polynomial decomposition of the meridional flows shows that the latitudinal pattern of the flow was also different during the maximum as compared to that during the two minima. We also find that the dominant component of the meridional flows during solar maxima was much lower than that during the minima of solar cycles 23 and 24.

  18. Towards Sustainable Flow Management - Introduction

    DEFF Research Database (Denmark)

    Moss, Timothy; Elle, Morten

    Outlines the conditions for the three Local Agenda 21 case-studies in the Sustainable Flow Management Project......Outlines the conditions for the three Local Agenda 21 case-studies in the Sustainable Flow Management Project...

  19. Towards Sustainable Flow Management - Introduction

    DEFF Research Database (Denmark)

    Moss, Timothy; Elle, Morten

    Outlines the conditions for the three Local Agenda 21 case-studies in the Sustainable Flow Management project......Outlines the conditions for the three Local Agenda 21 case-studies in the Sustainable Flow Management project...

  20. Radial flow pulse jet mixer

    Science.gov (United States)

    VanOsdol, John G.

    2013-06-25

    The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

  1. Make peak flow a habit!

    Science.gov (United States)

    Checking your peak flow is one of the best ways to control your asthma and to keep it from getting worse. Asthma attacks ... Most times, they build slowly. Checking your peak flow can tell you if an attack is coming, ...

  2. Optical diagnostics of intermittent flows

    DEFF Research Database (Denmark)

    Okulov, V.L.; Naumov, I.V.; Sørensen, Jens Nørkær

    2007-01-01

    image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach......The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle...... is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for...

  3. How Do Clinical Trials Work?

    Science.gov (United States)

    ... Trials Clinical Trial Websites How Do Clinical Trials Work? If you take part in a clinical trial, ... kol). This plan explains how the trial will work. The trial is led by a principal investigator ( ...

  4. Investigations on flow reversal in stratified horizontal flow

    International Nuclear Information System (INIS)

    The phenomena of flow reversal in stratified flows are investigated in a horizontal channel with application to the Emergency Core Cooling System (ECCS) in Pressurized Water Reactors (PWR). In case of a Loss-of-Coolant-Accident (LOCA), coolant can be injected through a secondary pipe within the feeding line of the primary circuit, the so called hot leg, counter-currently to the steam flow. It is essential that the coolant reaches the reactor core to prevent overheating. Due to high temperatures in such accident scenarios, steam is generated in the core, which escapes from the reactor vessel through the hot leg. In case of sufficiently high steam flow rates, only a reduced amount of coolant or even no coolant will be delivered to the reactor core. The WENKA test facility at the Institute for Nuclear and Energy Technologies (IKET) at Forschungszentrum Karlsruhe is capable to investigate the fluid dynamics of two-phase flows in such scenarios. Water and air flow counter-currently in a horizontal channel made of clear acrylic glass to allow full optical access. Flow rates of water and air can be varied independently within a wide range. Once flow reversal sets in, a strong hysteresis effect must be taken into account. This was quantified during the present investigations. Local experimental data are needed to expand appropriate models on flow reversal in horizontal two-phase flow and to include them into numerical codes. Investigations are carried out by means of Particle Image Velocimetry (PIV) to obtain local flow velocities without disturbing the flow. Due to the wavy character of the flow, strong reflections at the interfacial area must be taken into account. Using fluorescent particles and an optical filter allows eliminating the reflections and recording only the signals of the particles. The challenges in conducting local investigations in stratified wavy flows by applying optical measurement techniques are discussed. Results are presented and discussed allowing

  5. Developments in redox flow batteries

    OpenAIRE

    Tangirala, Ravichandra

    2011-01-01

    This thesis describes the investigation of the electrochemistry principles, technology, construction and composition of the electrode materials, electrolyte and additives used in redox flow batteries. The aim was to study a flow battery system with an appreciable working performance. The study explores and compares mainly three different redox flow battery technologies; all-vanadium, soluble lead-acid and a novel copper-lead dioxide flow batteries. The first system is based in sulfuric acid e...

  6. Traffic flow modeling: a Genealogy

    OpenAIRE

    Van Wageningen-Kessels, F.L.M.; Hoogendoorn, S.P.; Vuik, C.; Lint, van J. W. C.

    2014-01-01

    80 years ago, Bruce Greenshields presented the first traffic flow model at the Annual Meeting of the Highway Research Board. Since then, many models and simulation tools have been developed. We show a model tree with four families of traffic flow models, all descending from Greenshields' model. The tree shows the historical development of traffic flow modeling and the relations between models. Based on the tree we discuss the main trends and future developments in traffic flow modeling and si...

  7. Longitudinal Vortices in Granular Flows

    OpenAIRE

    Forterre, Yoel; Pouliquen, Olivier

    2001-01-01

    We present a new instability observed in rapid granular flows down rough inclined planes. For high inclinations and flow rates, the free surface of the flow experiences a regular deformation in the transverse direction. Measurements of the surface velocities imply that this instability is associated with the formation of longitudinal vortices in the granular flow. From the experimental observations, we propose a mechanism for the longitudinal vortex formation based on the concept of granular ...

  8. Spectral flow inside essential spectrum

    OpenAIRE

    Azamov, Nurulla

    2014-01-01

    The spectral flow is a classical notion of functional analysis and differential geometry which was given different interpretations as Fredholm index, Witten index, and Maslov index. The classical theory treats spectral flow outside the essential spectrum. Inside essential spectrum, the spectral shift function could be considered as a proper analogue of spectral flow, but unlike the spectral flow, the spectral shift function is not an integer-valued function. In this paper it is shown that the...

  9. Critical flow in the pipes

    International Nuclear Information System (INIS)

    On the basis of the homogeneous flow model and by using the basis constitutive equations describing the two-phase flow, the difference equation groups for calculating two-phase critical flow are derived. The influence of the changes of section, heat exchanges and so on the critical flow are considered. When the exit steam qualities are less than 0.1 or greater than 0.75 in the pipe line systems, this method is adapted to use

  10. Clinical Usefulness of Arbekacin.

    Science.gov (United States)

    Lee, Jae Hoon; Lee, Chang-Seop

    2016-03-01

    Arbekacin is a broad-spectrum aminoglycoside used to treat methicillin-resistant Staphylococcus aureus (MRSA). Arbekacin has antibacterial activities against high-level gentamicin-resistant Enterococci, multidrug-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii et al. Here, we reviewed in vitro data on arbekacin in Staphylococci and Gram-negative microorganisms. We also reviewed clinical studies for clinical efficacy and microbiologic efficacy data in patients with identified MRSA and suspected MRSA infections. The overall clinical efficacy ranged from 66.7% to 89.7%. The microbiologic efficacy rate ranged from 46.2% to 83%. In comparative studies between arbekacin and glycopeptides, arbekacin was similar to other glycopeptides with respect to clinical and microbiological efficacy rates. Combination trials with other antibiotics suggest that arbekacin will be a promising strategy to control Enterococcus spp. multi-drug resistant P. aeruginosa. The major adverse reaction was nephrotoxicity/hepatotoxicity, but patients recovered from most adverse reactions without any severe complications. Based on these results, arbekacin could be a good alternative to vancomycin/teicoplanin in MRSA treatment. Finally, therapeutic drug monitoring is recommended to maximize clinical efficacy and decrease nephrotoxicity. PMID:27104010

  11. Bulk flow scaling for turbulent channel and pipe flows

    CERN Document Server

    Chen, Xi; She, Zhen-Su

    2016-01-01

    We report a theory deriving bulk flow scaling for canonical wall-bounded flows. The theory accounts for the symmetries of boundary geometry (flat plate channel versus circular pipe) by a variational calculation for a large-scale energy length, which characterizes its bulk flow scaling by a simple exponent, i.e. $m=4$ for channel and 5 for pipe. The predicted mean velocity shows excellent agreement with several dozen sets of quality empirical data for a wide range of the Reynolds number (Re), with a universal bulk flow constant $\\kappa\\approx0.45$. Predictions for dissipation and turbulent transport in the bulk flow are also given, awaiting data verification.

  12. Skeletal Blood Flow in Bone Repair and Maintenance

    Institute of Scientific and Technical Information of China (English)

    Ryan E.Tomlinson; Matthew J.Silva

    2013-01-01

    Bone is a highly vascularized tissue, although this aspect of bone is often overlooked. In this article, the importance of blood flow in bone repair and regeneration will be reviewed. First, the skeletal vascular anato-my, with an emphasis on long bones, the distinct mechanisms for vascularizing bone tissue, and methods for remodeling existing vasculature are discussed. Next, techniques for quantifying bone blood flow are briefly summarized. Finally, the body of experimental work that demonstrates the role of bone blood flow in fracture healing, distraction osteogenesis, osteoporosis, disuse osteopenia, and bone grafting is examined. These results illustrate that adequate bone blood flow is an important clinical consideration, particularly during bone regeneration and in at-risk patient groups.

  13. In vitro and in vivo studies of pulmonary artery flow

    International Nuclear Information System (INIS)

    A variety of interesting intracardiac flow patterns have been recorded by pulsed and continuous wave Doppler technologies in humans with heart disease. Some of these patterns have, in fact, been difficult to explain and are now more easily understood using color Doppler flow mapping systems which show the spatial location of flow. The authors performed a number of studies in patients, as well as studies in in vitro systems to model some of the phenomenon that the authors observed in the pulmonary artery. Their studies with Doppler flow mapping in the clinical situation, in the in vitro model, and in the animal models of congenital heart disorders lend insights into the complex hydrodynamics present in the pulmonary artery

  14. Large amplitude oscillatory elongation flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Laillé, Philippe; Yu, Kaijia

    2008-01-01

    A filament stretching rheometer (FSR) was used for measuring the elongation flow with a large amplitude oscillative elongation imposed upon the flow. The large amplitude oscillation imposed upon the elongational flow as a function of the time t was defined as epsilon(t) =(epsilon) over dot(0)t...

  15. Prototype of calorimetric flow microsensor

    Science.gov (United States)

    Sazhin, Oleg

    2012-11-01

    An analytical model of calorimetric flow sensor has been developed. The results of the application of this model are utilized to develop a calorimetric flow microsensor with optimal functional characteristics. The technology to manufacture the microsensor is described. A prototype of the microsensor suitable to be used in the mass air flow meter has been designed. The basic characteristics of the microsensor are presented.

  16. Liquid/Gas Flow Mixers

    Science.gov (United States)

    Fabris, Gracio

    1994-01-01

    Improved devices mix gases and liquids into bubbly or foamy flows. Generates flowing, homogeneous foams or homogeneous dispersions of small, noncoalescing bubbles entrained in flowing liquids. Mixers useful in liquid-metal magnetohydrodynamic electric-power generator, froth flotation in mining industry, wastewater treatment, aerobic digestion, and stripping hydrocarbon contaminants from ground water.

  17. [Clinical investigation of striatocapsular infarction].

    Science.gov (United States)

    Tei, H; Uchiyama, S; Maruyama, S

    1993-03-01

    We investigated the clinical profile, etiological factors, neuropsychological features and radiological characteristics of 17 cases of striatocapsular infarction (SCI). SCI was defined as the following CT criteria: the area of infarction included the internal capsule and striatum, the maximum diameter of the lesion exceeded 2.0 cm without cortical involvement. There were 9 men and 8 women with mean age of 58 years. Five patients had lesions mainly involving the caudate head (anterior type) and the other 12 had lesions mainly involving the putamen (lateral type), 6 with left side lesion and 6 with right side lesion. Motor weakness was observed in all patients, and the upper extremities were preferentially involved, while in 9 patients face, upper and lower extremities were simultaneously involved. Etiological investigation revealed that 8 patients were cardioembolic stroke, 2 were artery-to-artery embolism and 2 were MCA stem occlusive disease, while the remaining 5 were undetermined. When compared with patients with lacunar infarction (LI), patients with SCI had significantly more frequent cardioembolic sources (47% vs 17%, p abulia, depression and agitation, while left lateral type patients had aphasia and right lateral type patients had hemispatial neglect or anosognosia. These symptoms gradually improved, although in most patients subtle abnormalities lasted over chronic phase. In 11 out of 13 patients who underwent SPECT using 99mTc-HMPAO, blood flow was decreased in overlying cerebral cortex besides the infarcted area.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8334792

  18. Online traffic flow model applying dynamic flow-density relation

    CERN Document Server

    Kim, Y

    2002-01-01

    This dissertation describes a new approach of the online traffic flow modelling based on the hydrodynamic traffic flow model and an online process to adapt the flow-density relation dynamically. The new modelling approach was tested based on the real traffic situations in various homogeneous motorway sections and a motorway section with ramps and gave encouraging simulation results. This work is composed of two parts: first the analysis of traffic flow characteristics and second the development of a new online traffic flow model applying these characteristics. For homogeneous motorway sections traffic flow is classified into six different traffic states with different characteristics. Delimitation criteria were developed to separate these states. The hysteresis phenomena were analysed during the transitions between these traffic states. The traffic states and the transitions are represented on a states diagram with the flow axis and the density axis. For motorway sections with ramps the complicated traffic fl...

  19. Flow choking over weir flow slit-type flip buckets

    Institute of Scientific and Technical Information of China (English)

    马飞; 徐准; 吴建华

    2015-01-01

    The flow choking may occur for weir flow slit-type flip buckets under common operation conditions. An estimation method is developed through introducing a comprehensive coefficient to determine the approach flow Froude number for the flow choking to occur in those flip buckets. The error of the present method relative to the experimental data is less than 5%. The results show that, the Froude number for the flow choking to occur is related to the contraction ratio and the contraction angle of the flip buckets. When the flow choking occurs, the upper jet trajectory decreases and the lower one is almost not affected, and the dynamic pressures on the bottom and the sidewalls increase due to the flow profile rising on the flip buckets.

  20. Gas flow meter and method for measuring gas flow rate

    Science.gov (United States)

    Robertson, Eric P.

    2006-08-01

    A gas flow rate meter includes an upstream line and two chambers having substantially equal, fixed volumes. An adjustable valve may direct the gas flow through the upstream line to either of the two chambers. A pressure monitoring device may be configured to prompt valve adjustments, directing the gas flow to an alternate chamber each time a pre-set pressure in the upstream line is reached. A method of measuring the gas flow rate measures the time required for the pressure in the upstream line to reach the pre-set pressure. The volume of the chamber and upstream line are known and fixed, thus the time required for the increase in pressure may be used to determine the flow rate of the gas. Another method of measuring the gas flow rate uses two pressure measurements of a fixed volume, taken at different times, to determine the flow rate of the gas.

  1. [Terminology in clinical bioethics].

    Science.gov (United States)

    Herreros, Benjamín; Moreno-Milán, Beatriz; Pacho-Jiménez, Eloy; Real de Asua, Diego; Roa-Castellanos, Ricardo Andrés; Valentia, Emanuele

    2015-01-01

    In this article some of the most relevant terms in clinical bioethics are defined. The terms were chosen based on three criteria: impact on the most important problems in clinical bioethics, difficulty in understanding, and need to clarify their meaning. For a better understanding, the terms were grouped into 5 areas: general concepts (conflict of values, deliberation, conflict of interest, conscientious objection); justice (justice, distributive justice, models of justice, triage); clinical matters (information, competency, capability, informed consent, mature minor, coercion, secrecy, privacy, confidentiality, professional secrecy); end of life (prior instructions, limitation of therapeutic efforts, professional obstinacy, futility, palliative care, palliative sedation, principle of double effect, euthanasia, assisted suicide, persistent vegetative state, minimally conscious state, locked-in syndrome, brain death), and beginning of life (assisted reproduction, genetic counseling, preimplantation genetic diagnosis). PMID:26506495

  2. Automated High-Dimensional Flow Cytometric Data Analysis

    Science.gov (United States)

    Pyne, Saumyadipta; Hu, Xinli; Wang, Kui; Rossin, Elizabeth; Lin, Tsung-I.; Maier, Lisa; Baecher-Allan, Clare; McLachlan, Geoffrey; Tamayo, Pablo; Hafler, David; de Jager, Philip; Mesirov, Jill

    Flow cytometry is widely used for single cell interrogation of surface and intracellular protein expression by measuring fluorescence intensity of fluorophore-conjugated reagents. We focus on the recently developed procedure of Pyne et al. (2009, Proceedings of the National Academy of Sciences USA 106, 8519-8524) for automated high- dimensional flow cytometric analysis called FLAME (FLow analysis with Automated Multivariate Estimation). It introduced novel finite mixture models of heavy-tailed and asymmetric distributions to identify and model cell populations in a flow cytometric sample. This approach robustly addresses the complexities of flow data without the need for transformation or projection to lower dimensions. It also addresses the critical task of matching cell populations across samples that enables downstream analysis. It thus facilitates application of flow cytometry to new biological and clinical problems. To facilitate pipelining with standard bioinformatic applications such as high-dimensional visualization, subject classification or outcome prediction, FLAME has been incorporated with the GenePattern package of the Broad Institute. Thereby analysis of flow data can be approached similarly as other genomic platforms. We also consider some new work that proposes a rigorous and robust solution to the registration problem by a multi-level approach that allows us to model and register cell populations simultaneously across a cohort of high-dimensional flow samples. This new approach is called JCM (Joint Clustering and Matching). It enables direct and rigorous comparisons across different time points or phenotypes in a complex biological study as well as for classification of new patient samples in a more clinical setting.

  3. Clinical pharmacology and malaria.

    Science.gov (United States)

    Breckenridge, A M; Winstanley, P A

    1997-10-01

    The role of clinical pharmacology in improving the prevention and treatment of malaria is reviewed. A series of general and specific issues is discussed, concentrating on risk-benefit and cost-effectiveness. The techniques of clinical pharmacokinetics play an important role in the optimal use of drugs and this is illustrated by studies on quinine and proguanil. In discussing amodiaquine toxicity, the role of the pharmacologist and the chemist in designing out drug toxicity lends hope for producing a new generation of antimalarial drugs. PMID:9625927

  4. Heart blood flow simulation: a perspective review.

    Science.gov (United States)

    Doost, Siamak N; Ghista, Dhanjoo; Su, Boyang; Zhong, Liang; Morsi, Yosry S

    2016-01-01

    Cardiovascular disease (CVD), the leading cause of death today, incorporates a wide range of cardiovascular system malfunctions that affect heart functionality. It is believed that the hemodynamic loads exerted on the cardiovascular system, the left ventricle (LV) in particular, are the leading cause of CVD initiation and propagation. Moreover, it is believed that the diagnosis and prognosis of CVD at an early stage could reduce its high mortality and morbidity rate. Therefore, a set of robust clinical cardiovascular assessment tools has been introduced to compute the cardiovascular hemodynamics in order to provide useful insights to physicians to recognize indicators leading to CVD and also to aid the diagnosis of CVD. Recently, a combination of computational fluid dynamics (CFD) and different medical imaging tools, image-based CFD (IB-CFD), has been widely employed for cardiovascular functional assessment by providing reliable hemodynamic parameters. Even though the capability of CFD to provide reliable flow dynamics in general fluid mechanics problems has been widely demonstrated for many years, up to now, the clinical implications of the IB-CFD patient-specific LVs have not been applicable due to its limitations and complications. In this paper, we review investigations conducted to numerically simulate patient-specific human LV over the past 15 years using IB-CFD methods. Firstly, we divide different studies according to the different LV types (physiological and different pathological conditions) that have been chosen to reconstruct the geometry, and then discuss their contributions, methodologies, limitations, and findings. In this regard, we have studied CFD simulations of intraventricular flows and related cardiology insights, for (i) Physiological patient-specific LV models, (ii) Pathological heart patient-specific models, including myocardial infarction, dilated cardiomyopathy, hypertrophic cardiomyopathy and hypoplastic left heart syndrome. Finally, we

  5. Let It Flow

    Institute of Scientific and Technical Information of China (English)

    Alphonce; Shiundu

    2011-01-01

    Ghana’s Jubilee oilfield output projected to more than double by year-end AFRICA’S Gold Coast,otherwise known as the Republic of Ghana,marked the first 100 days since its oil taps began running,on March 25,2011.The oil in question flows from the country’s offshore Jubilee oilfield, recognized by the stakeholders to be the largest oil discovery in West Africa in the last 10 to 15 years. This discovery has injected an air of optimism amongst Ghana-

  6. Providing Compassion through Flow

    Directory of Open Access Journals (Sweden)

    Lydia Royeen

    2015-07-01

    Full Text Available Meg Kral, MS, OTR/L, CLT, is the cover artist for the Summer 2015 issue of The Open Journal of Occupational Therapy. Her untitled piece of art is an oil painting and is a re-creation of a photograph taken while on vacation. Meg is currently supervisor of outpatient services at Rush University Medical Center. She is lymphedema certified and has a specific interest in breast cancer lymphedema. Art and occupational therapy serve similar purposes for Meg: both provide a sense of flow. She values the outcomes, whether it is a piece of art or improved functional status

  7. Sulphur flows on Io

    International Nuclear Information System (INIS)

    Voyager 1 close-encounter photomosaics have clarified both the coloration of Io and its surface variation. These colour patterns seem explicable in terms of liquid sulphur produced in ionian volcanoes and solfataras and quenched at Io ambient temperatures approximately equal to 135 K. The liquid sulphur flow fronts and frozen rivers which appear in the Voyager images are discussed. It is argued that the volcanic deposition rates and the vapour pressure over sulphur melts are both consistent with the notion that the surface of Io changes significantly in geologically very short periods of time. (UK)

  8. Flow in journalistic telework.

    Science.gov (United States)

    Manssour, Ana Beatriz Benites

    2003-02-01

    Since the 1980s, the strengthening and dissemination of telework has motivated studies to verify its advantages and disadvantages to enterprises and workers, specially focusing on economy, quality, and productivity performances. This paper developed from a master's thesis research which analyzed the subjective impact of telework concerning workers' personal satisfaction, their perception about suffering and pleasure when developing their work activities and social interrelationships, and, particularly, the influence it could have in their maximum experiences, the flow. Considering that the press media represents a historical telework, it was chosen as the research focus, selecting columnists from a large newspaper, located in the Brazilian south region. PMID:12650561

  9. Flow tracing based on current

    Institute of Scientific and Technical Information of China (English)

    蔡兴国; 曹海龙

    2001-01-01

    Analyses the flow tracing based on power flow, points out that the detachment of reactive power and active power is unrealiable and concludes that the current is the real basic of flow tracing,and proposes the new flow tracing model based on current, which devides the current into active current and reactive current, analyses the theory about the matrix to deal with the precision and realization of the flow tracing, and then proposes a new pricing model by fixed rate and marginal rate, which keeps not only economy information such as congestion cost in marginal cost based pricing, but also benefits to make both ends meet.

  10. Overview of zonal flow physics

    International Nuclear Information System (INIS)

    Zonal flows, by which we mean azimuthally symmetric band-like shear flows, are ubiquitous phenomena in nature and the laboratory. It is now widely recognized that zonal flows are a key constituent in virtually all cases and regimes of drift wave turbulence, indeed, so much so that this classic problem is now frequently referred to as 'drift wave-zonal flow turbulence'. In this theory overview, we present new viewpoints and unifying concepts which facilitate understanding of zonal flow physics, via theory, computation and their confrontation with the results of laboratory experiment. Special emphasis is placed on identifying avenues for further progress. (author)

  11. Heat exchanger with oscillating flow

    Science.gov (United States)

    Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)

    1993-01-01

    Various heat exchange apparatuses are described in which an oscillating flow of primary coolant is used to dissipate an incident heat flux. The oscillating flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic oscillators or electromagnetic pumps. The oscillating fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.

  12. Flow in air conditioned rooms

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    1974-01-01

    Flow in air conditioned r ooms is examined by means of model experiments . The different gearnetries giving unsteady, steady three- dimensional and steady twodimensional flow are determined . Velacity profiles and temperature profiles are measured in some of the geometries. A numerical solution...... of the flow equations is demonstrated and the flow in air conditioned rooms in case of steady two dimensional flow is predi cted. Compari son with measured results is shown i n the case of small Archimedes numbers, and predictions are shown at high Archimedes numbers. A numerical prediction of f low and heat...

  13. Industrial energy-flow management

    International Nuclear Information System (INIS)

    Deregulation of the energy market has created new opportunities for the development of new energy-management methods based on energy assets, risk management, energy efficiency and sustainable development. Industrial energy-flow management in pharmaceutical systems, with a responsible approach to sustainable development, is a complex task. For this reason, an energy-information centre, with over 14,000 online measured data/nodes, was implemented. This paper presents the energy-flow rate, exergy-flow rate and cost-flow rate diagrams, with emphasis on cost-flow rate per energy unit or exergy unit of complex pharmaceutical systems

  14. Minimal flows and their extensions

    CERN Document Server

    Auslander, J

    1988-01-01

    This monograph presents developments in the abstract theory of topological dynamics, concentrating on the internal structure of minimal flows (actions of groups on compact Hausdorff spaces for which every orbit is dense) and their homomorphisms (continuous equivariant maps). Various classes of minimal flows (equicontinuous, distal, point distal) are intensively studied, and a general structure theorem is obtained. Another theme is the ``universal'' approach - entire classes of minimal flows are studied, rather than flows in isolation. This leads to the consideration of disjointness of flows, w

  15. CME ON CLINICAL RESEARCH

    Directory of Open Access Journals (Sweden)

    Suneel. I. Majagi

    2012-06-01

    Full Text Available Safety and efficacy are the two major concerns for any drug therapy. Globally clinical research plays an inevitable role in bringing a new molecule into the market after its synthesis by the pharmaceutical industries. Availability of large patient population, highly educated and skilled manpower, wide spectrum of diseases and favorable economic environment imply India’s potential as a global hub for clinical research. Pharmaceutical companies and Clinical Research Organization (CROs will require many trained personnel to carry out the clinical research. Keeping in mind these facts a CME with the theme of “Clinical research” had been jointly organized by the Dept of pharmacology, K.L.E University’s J.N.M.C, Belgaum and Indian Pharmacological Society (I.P.S, Belgaum branch on 20th February 2010. In the first scientific session, Dr.P.A.Patil (JNMC spoke on “Preclinical studies”. In vitro and in vivo experiments of various doses of ‘study drug’ can obtain preliminary efficacy, toxicity and pharmacokinetic information suggesting the scientific merit for further development as an investigational new drug (IND. Local or systemic toxicity studies can be conducted (ex: urine analysis, blood biochemical assay, gross and microscopic pathology etc. Dr. B.J. Mahendra Kumar (KLE University’s College of pharmacy talked on “Role of Drug Controller General of India (DCGI in Clinical Trials”. He explained about Drug and cosmetic acts/rules, requirements/guidelines for permission to import and/or to manufacture new drugs or to undertake clinical trials i.e. Schedule Y and its appendices. Dr.N.M.Patil (JNMC elaborated about “Ethical issues in clinical trials”. Ethics is required to: avoid exploitation of the subjects (maintain safety and wellbeing, protect vulnerable groups, children, disabled, elderly etc. Independent Ethics Committees (IEC and Institutional Review Boards (IRB are concerned with medical ethics. IECs review, regulate

  16. Clinical reasoning of nursing students on clinical placement: Clinical educators' perceptions.

    Science.gov (United States)

    Hunter, Sharyn; Arthur, Carol

    2016-05-01

    Graduate nurses may have knowledge and adequate clinical psychomotor skills however they have been identified as lacking the clinical reasoning skills to deliver safe, effective care suggesting contemporary educational approaches do not always facilitate the development of nursing students' clinical reasoning. While nursing literature explicates the concept of clinical reasoning and develops models that demonstrate clinical reasoning, there is very little published about nursing students and clinical reasoning during clinical placements. Semi-structured interviews were conducted with ten clinical educators to gain an understanding of how they recognised, developed and appraised nursing students' clinical reasoning while on clinical placement. This study found variability in the clinical educators' conceptualisation, recognition, and facilitation of students' clinical reasoning. Although most of the clinical educators conceptualised clinical reasoning as a process those who did not demonstrated the greatest variability in the recognition and facilitation of students' clinical reasoning. The clinical educators in this study also described being unable to adequately appraise a student's clinical reasoning during clinical placement with the use of the current performance assessment tool. PMID:27235568

  17. Numerical simulation of steady flow fields in coiled flow inverter

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vimal; Nigam, K.D.P. [Department of Chemical Engineering, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110 016 (India)

    2005-11-01

    Flatter velocity profiles and more uniform thermal environments are extremely desirous factors for improved performance in flow reactors and heat exchangers. One means of achieving it in laminar flow systems is to use mixers and flow inverters. In the present study a new device is introduced based on the flow inversion by changing the direction of centrifugal force in helically coiled tubes. The objective of the present study is to characterize flow development and temperature fields in the proposed device made up from the configurations of bent coils. The main mechanism generating the flow is the production of spatially chaotic path by changing the direction of flow using a 90{sup o} bend in helical coils (alternating Dean flow). If the direction of centrifugal force is rotated by any angle, the plane of vortex formation also rotates with the same angle. Thus in helical flow a 90{sup o} shift in the direction of centrifugal force cause a complete flow inversion. Complete flow fields and thermal fields in helical coil and bent coil configuration were studied using computational fluid dynamics software (FLUENT 6.0). The three-dimensional governing equations for momentum and energy under the laminar flow conditions were solved with a control-volume finite difference method (CVFDM) with second-order accuracy. The flow pattern obtained for the helical coil was in good agreement to those observed by the previous investigators [S.W. Jones, O.M. Thomas, H. Aref, Chaotic advection by laminar flow in twisted pipe. J. Fluid Mech. 209 (1989) 335-357; Ch. Duchene, H. Peerhossaini, P.J. Michard, On the velocity field and tracer patterns in a twisted duct flow. Phys. Fluids 7 (1995) 1307-1317]. The comparison of the flow fields and temperature fields in the helical tube and bent coil configuration are discussed. The bent coil configuration shows a 20-30% enhancement in the heat transfer due to chaotic mixing while relative pressure drop is 5-6%. The results of the present study

  18. Experimental investigation of cavity flows

    Energy Technology Data Exchange (ETDEWEB)

    Loeland, Tore

    1998-12-31

    This thesis uses LDV (Laser Doppler Velocimetry), PIV (Particle Image Velocimetry) and Laser Sheet flow Visualisation to study flow inside three different cavity configurations. For sloping cavities, the vortex structure inside the cavities is found to depend upon the flow direction past the cavity. The shape of the downstream corner is a key factor in destroying the boundary layer flow entering the cavity. The experimental results agree well with numerical simulations of the same geometrical configurations. The results of the investigations are used to find the influence of the cavity flow on the accuracy of the ultrasonic flowmeter. A method to compensate for the cavity velocities is suggested. It is found that the relative deviation caused by the cavity velocities depend linearly on the pipe flow. It appears that the flow inside the cavities should not be neglected as done in the draft for the ISO technical report on ultrasonic flowmeters. 58 refs., 147 figs., 2 tabs.

  19. Experimental study of flow artifact in MRI venous flow model

    International Nuclear Information System (INIS)

    Venous flow models were constructed and experiments were done on the signal generation from blood flow. MRI apparatus used was 1.0T Shimadzu SMT100. Images were constructed by 2D Fourrier conversion. The magnetic intensity was 1.5 mT/m. Continuous 6 slices of 10, 7 and 5 mm thickness were imaged in T2-weighted condition at TR 2500 msec and TE 90 msec by the spin echo method, rephasing method, presaturation method, rephasing + presaturation method and rephasing + presaturation + low sampling cycle method for flow rate and pulsatile flow. The artificial blood vessels were made of polychlorinated vinyl tube with inner diameter 8 mm x 20 m length where 40 litre of water was circulated at a fixed flow rate of 5-30 cm/sec or pulsatile flow rate of 15 and 20 cm/sec. A tube filled with Gd-DTPA solution was used as a control. S/N ratio in every slice of the fixed and pulsatile flows, the difference by the direction of imaging, the presence or absence of rephasing and presaturation and sampling cycles were examined. A significant flow artifact was found yielded for the pulsatile flow relative to the fixed flow. (K.H.)

  20. Experimental research of the couette flow with cross flow

    Science.gov (United States)

    Nobis, Matthias; Stücke, Peter; Schmidt, Marcus

    2012-04-01

    When a solid cylinder is rotating inside a hollow cylinder, a characteristic fluid flow occurs inside the gap between the two cylinders, caused by the adhesion of the fluid at the walls. This flow problem is widely known as the Couette-flow. If an additional flow entrances through a radial located feedhole at the outer hollow cylinder, there is an interaction between the cross flow and the Couette-flow. In result there are complex three dimensional flow structures in the gap at the area around the feedhole. These arising flow structures are closely related with the technical important flow inside the gap of hydrodynamic lubricated journal bearings. When the flow conditions inside the bearing gap are well explored and appreciated, it will be possible to give suggestions for constructive details like the design, the location and the dimension of the feedhole for longer lifecycles or an even more efficiently running. In this paper the test rig of the bearing model will be presented. Moreover some representative results from researches with a Laser-Doppler-Velocimeter (LDV) in comparison with the output of three dimensional numerical simulations will be illustrated.

  1. ClinicalAccess: a clinical decision support tool.

    Science.gov (United States)

    Crowell, Karen; Vardell, Emily

    2015-01-01

    ClinicalAccess is a new clinical decision support tool that uses a question-and-answer format to mirror clinical decision-making strategies. The unique format of ClinicalAccess delivers concise, authoritative answers to more than 120,000 clinical questions. This column presents a review of the product, a sample search, and a comparison with other point-of-care search engines. PMID:25927513

  2. Prolactinomas : clinical studies

    NARCIS (Netherlands)

    Kars, Marleen

    2008-01-01

    Prolactinoma are treated with dopamine agonists, which are effective in reducing prolactin and tumor size. Studies reporting clinical and radiological outcome are scarce. The study described in chapter 2, assesses long-term outcome in patients treated with dopamine agonists for macroprolactinoma. An

  3. The Clinical Supervision Process.

    Science.gov (United States)

    Ramsey, MaryLou

    This document defines clinical supervision as an intensive, interpersonally-focused, one-to-one relationship in which one person is designated to facilitate the development of therapeutic competence in the other person. Ways in which supervision is similar to, and different from, therapy are explained. The following stages in the clinical…

  4. Participating in Clinical Trials

    Medline Plus

    Full Text Available ... to find out if an experimental drug, therapy, medical device, lifestyle change, or test will help treat, find, or prevent a disease. A clinical trial may compare experimental products or ... universities and medical centers across the country. The National Institutes of ...

  5. The Unstructured Clinical Interview

    Science.gov (United States)

    Jones, Karyn Dayle

    2010-01-01

    In mental health, family, and community counseling settings, master's-level counselors engage in unstructured clinical interviewing to develop diagnoses based on the "Diagnostic and Statistical Manual of Mental Disorders" (4th ed., text rev.; "DSM-IV-TR"; American Psychiatric Association, 2000). Although counselors receive education about…

  6. Clinically isolated laryngeal sarcoidosis

    DEFF Research Database (Denmark)

    Plaschke, Christina Caroline; Owen, Hanne Hoejris; Rasmussen, Niels

    2011-01-01

    combination of CO(2)-laser excision of supraglottic tissue and closure of the incision with sutures. All serological tests were negative or normal, including angiotensin 1 converting enzyme. The clinical expression was uniform with pale, smooth swellings of the supraglottic structures. Surgery proved...

  7. Clinical spectrum of onchodermatitis

    International Nuclear Information System (INIS)

    To describe the frequency and to see various dermatological presentations of onchocerciasis in black Africans of Sierra Leone. Local black patients of all age groups, attending dermatology outpatient department of Pak Field Hospital (established as a part of UN peacekeeping mission in Sierra Leone) with clinical diagnosis of onchodermatitis, based on symptomatology and morphological features of the disease, were included. UN troops were excluded. Laboratory investigations including blood complete picture and skin snips were carried out in all patients. Skin biopsy and nodule biopsy was performed in selected cases. Skin manifestations were recorded and categorized into various clinical patterns, i.e. acute, chronic, lichenified, onchocercoma, etc. Data was analyzed by using descriptive statistics in Instat. A total of 3011 patients, belonging to different local tribes, having a variety of skin disorders, were seen during the study period. One hundred and eighty-seven (6.2%) patients were found to have onchodermatitis. Patients were of all ages and both sexes, their ages ranging from 1 month to 73 years. Gender ratio was almost equal. A whole clinical spectrum of onchodermatitis was observed, chronic papular onchodermatitis being the most common pattern. Onchodermatitis with a large spectrum of clinical manifestations was seen in black Africans of the eastern part of Sierra Leone. (author)

  8. Hepatitis C: Clinical Trials

    Science.gov (United States)

    ... Reports Clinician Tools Clinician Tools Home Guidelines and Best Practices Topic Reviews Algorithms, Screens, Toolkits Provider Education Provider ... about federally and privately supported clinical research in human volunteers. Site gives information about a trial's purpose, who may participate, locations, and phone ... Forms State and Local Resources Strat Plan FY 2014-2020 VA Plans, Budget, & ...

  9. Radioimmunoimaging in clinical oncology

    International Nuclear Information System (INIS)

    In the thesis radiolabeled antibodies were tested for screening of cancer in patients without previous knowledge of tumour histopathology. They were tested as well targeting known cancer, sometimes in unknown clinical stage. Methods for detection enhancement utilizing double-tracer techniques and alternative routes of administration were also investigated. (385 refs., 11 tabs.)

  10. Clinical Positioning Space

    DEFF Research Database (Denmark)

    Williams, Lars Peter Hedegaard; Christensen, Mette Krogh; Rytter, Carsten;

    2014-01-01

    In this article, we present a case study of residents’ clinical experiences and communication in outpatient oncology consultations. We apply positioning theory, a dynamic alternative to role theory, to investigate how oncology residents and patients situate themselves as persons with rights and d...

  11. Clinical Mastery of Hypnosis.

    Science.gov (United States)

    Horevitz, Richard P.

    Hypnosis is an increasingly popular clinical intervention. The number of training courses in hypnosis is growing each year. Research on hypnosis training appears to show that limited exposure to training, as is typical in the common 3 to 5 day format of mass training, produces limited results. Only when training is extended over time do the…

  12. OARSI Clinical Trials Recommendations

    DEFF Research Database (Denmark)

    Kraus, V B; Blanco, F J; Englund, M;

    2015-01-01

    The objective of this work was to describe requirements for inclusion of soluble biomarkers in osteoarthritis (OA) clinical trials and progress toward OA-related biomarker qualification. The Guidelines for Biomarkers Working Group, representing experts in the field of OA biomarker research from b...

  13. [Clinical examination of vertigo].

    Science.gov (United States)

    Topka, Helge Roland

    2016-07-01

    Acute vertigo may originate from peripheral or central vestibular disorders. As central vestibular symptoms may indicate severe brainstem or cerebellar ischemia, rapid clinical differentiation is required. To this end, evaluation of spontaneous or gaze-evoked nystagm, head-impulse test as well identification of skew deviation are most helpful. PMID:27464281

  14. Magnesium in Clinical Practice

    OpenAIRE

    E.L. Trisvetova

    1989-01-01

    Magnesium is a macronutrient that is needed for normal body functions. Magnesium deficiency resulting from the influence of exogenous and endogenous factors, is diagnosed by clinical manifestations, resembling the known disease. Magnesium deficiency corrected with the magnesium therapy. Studies show the effectiveness of magnesium orotate for many cardiovascular diseases.

  15. Data flow computing

    International Nuclear Information System (INIS)

    In the design of supercomputer systems, anticipated needs and available technology play a crucial role. Most current approaches start from the same basic technology premise: advances in VLSI represent a significant improvement in hardware components than can produce valuable gains in the cost/performance ratios of new systems. The key to this cost/performance ratio is replication of relatively cheap components. Hence, almost all the current supercomputer designs are multiprocessors. The critical question becomes, how can a designer organize them for effective problem solving? Here, different user needs have led to research into several design strategies. Consider, for example, the needs of a ballistic missile defense system. This application requires real-time response and processing of large amounts of data that can be received at very uneven rates. For cost/effectiveness, the best computer system would automatically adjust to the current nature and demands of the computing load placed on it. Dynamically reconfigurable architectures address this type of application. As another example, consider the problem of monitoring and controlling a large nuclear reactor. In this case, real-time response is still important. However, reconfiguration may not be so crucial because monitoring sensors receive a relatively steady flow of data to process. A dedicated computer system may be more appropriate for this case. This chapter presents the data-flow computing strategy

  16. UZ Flow Models and Submodels

    International Nuclear Information System (INIS)

    The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11

  17. Integrated clinical information system.

    Science.gov (United States)

    Brousseau, G

    1995-01-01

    SIDOCI (Système Informatisé de DOnnées Cliniques Intégrées) is a Canadian joint venture introducing newly-operating paradigms into hospitals. The main goal of SIDOCI is to maintain the quality of care in todayUs tightening economy. SIDOCI is a fully integrated paperless patient-care system which automates and links all information about a patient. Data is available on-line and instantaneously to doctors, nurses, and support staff in the format that best suits their specific requirements. SIDOCI provides a factual and chronological summary of the patient's progress by drawing together clinical information provided by all professionals working with the patient, regardless of their discipline, level of experience, or physical location. It also allows for direct entry of the patient's information at the bedside. Laboratory results, progress notes, patient history and graphs are available instantaneously on screen, eliminating the need for physical file transfers. The system, incorporating a sophisticated clinical information database, an intuitive graphical user interface, and customized screens for each medical discipline, guides the user through standard procedures. Unlike most information systems created for the health care industry, SIDOCI is longitudinal, covering all aspects of the health care process through its link to various vertical systems already in place. A multidisciplinary team has created a clinical dictionary that provides the user with most of the information she would normally use: symptoms, signs, diagnoses, allergies, medications, interventions, etc. This information is structured and displayed in such a manner that health care professionals can document the clinical situation at the touch of a finger. The data is then encoded into the patient's file. Once encoded, the structured data is accessible for research, statistics, education, and quality assurance. This dictionary complies with national and international nomenclatures. It also

  18. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    Science.gov (United States)

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  19. Measurement of tumor blood flow following neutron irradiation

    International Nuclear Information System (INIS)

    Clinical oncologists and cancer researchers benefit from information on the vascularization or non-vascularization of solid tumors because of blood flow's influence on three popular treatment types: hyperthermia therapy, radiotherapy, and chemotherapy. The objective of this research is the development of a clinically useful tumor blood flow measurements technique. The designed technique is sensitive, has good spatial resolution, in non-invasive and presents no risk to the patient beyond his usual treatment. Tumor blood flow was determined by measuring the washout of positron emitting isotopes created through neutron therapy treatment. In order to do this, several technical and scientific questions were addressed first. These questions have been answered through both theoretical calculation and measurement. The first question was answered through the measurement of macroscopic cross sections for the predominant nuclear reactions in the body. These results correlate well with an independent mathematical prediction of tissue activation and measurements of mouse spleen neutron activation. The second question was addressed by performing cell suspension and protein precipitation techniques on neutron activated mouse spleens. The third and final question was answered by using first physical principles to develop a model mimicking the blood flow system and measurement technique. In a final set of experiments, the above were applied to flow models and animals. The ultimate aim of this project is to apply its methodology to neutron therapy patients

  20. Clinical Data Warehousing - A Survey

    DEFF Research Database (Denmark)

    Pedersen, Torben Bach; Jensen, Christian Søndergaard

    1998-01-01

    In this article we present the concept of data warehousing, and its use in the clinical area. Clinical data warehousing will become very important in the near future, as healthcare enterprises need to gain more information from their clinical, administrative, and financial data, in order to impro...... the area, and providing criteria for comparing clinical data warehouse systems....