Transcatheter aortic valve replacement: impact of pre-procedural FEops HEARTguide assessment on device size selection in borderline annulus size cases

ObjectivesThe aim of this study is to evaluate device size selection in patients within the borderline annulus size range undergoing transcatheter aortic valve replacement (TAVR) and to assess if pre-procedural patient-specific computer simulation will lead to the selection of a different device size than standard of care.BackgroundIn TAVR, appropriate device sizing is imperative. In borderline annulus size cases no standardised technique for tailored device size selection is currently available. Pre-procedural patient-specific computer simulation can be used, predicting the risk for paravalvular leakage (PVL) and need for permanent pacemaker implantation (PPI).MethodsIn this multicentre retrospective study, 140 patients in the borderline annulus size range were included. Hereafter, device size selection was left to the discretion of the operator. After TAVR, in 24 of the 140 patients, patient-specific computer simulation calculated the most appropriate device size expected to give the lowest risk for PVL and need for PPI. In these 24 patients, device size selection based on patient-specific computer simulation was compared with standard-of-care device size selection relying on a standardised matrix (Medtronic).ResultsIn a significant proportion of the 140 patients (26.4%) a different device size than recommended by the matrix was implanted. In 10 of the 24 patients (41.7%) in whom a computer simulation was performed, a different device size was recommended than by means of the matrix.ConclusionsDevice size selection in patients within the borderline annulus size range is still ambiguous. In these patients, patient-specific computer simulation is feasible and can contribute to a more tailored device size selection.     

Randomised trial of personalised computer based information for cancer patients

ObjectiveTo compare the use and effect of a computer based information system for cancer patients that is personalised using each patient''s medical record with a system providing only general information and with information provided in booklets.DesignRandomised trial with three groups. Data collected at start of radiotherapy, one week later (when information provided), three weeks later, and three months later.Participants525 patients started radical radiotherapy; 438 completed follow up.InterventionsTwo groups were offered information via computer (personalised or general information, or both) with open access to computer thereafter; the third group was offered a selection of information booklets.OutcomesPatients'' views and preferences, use of computer and information, and psychological status; doctors'' perceptions; cost of interventions.ResultsMore patients offered the personalised information said that they had learnt something new, thought the information was relevant, used the computer again, and showed their computer printouts to others. There were no major differences in doctors'' perceptions of patients. More of the general computer group were anxious at three months. With an electronic patient record system, in the long run the personalised information system would cost no more than the general system. Full access to booklets cost twice as much as the general system.ConclusionsPatients preferred computer systems that provided information from their medical records to systems that just provided general information. This has implications for the design and implementation of electronic patient record systems and reliance on general sources of patient information.     

Randomised trial of personalised computer based information for patients with schizophrenia

ObjectivesTo compare use, effect, and cost of personalised computer education with community psychiatric nurse education for patients with schizophrenia.DesignRandomised trial of three interventions. Modelling of costs of alternatives.Participants112 patients with schizophrenia in contact with community services; 67 completed the intervention.InterventionsThree interventions of five educational sessions: (a) computer intervention combining information from patient''s medical record with general information about schizophrenia; (b) sessions with a community psychiatric nurse; (c) “combination” (first and last sessions with nurse and remainder with computer).ResultsRates of completion of intervention did not differ significantly (71% for combination intervention, 61% for computer only, 46% for nurse only). Computer sessions were shorter than sessions with nurse (14 minutes v 60 minutes). More patients given nurse based education thought the information relevant. Of 20 patients in combination group, 13 preferred the sessions with the nurse and seven preferred the computer. There were no significant differences between groups in psychological outcomes. Because of the need to transport patients to the computer for their sessions, there was no difference between interventions in costs, but computer sessions combined with other patient contacts would be substantially cheaper.ConclusionsThe computer based patient education offered no advantage over sessions with a community psychiatric nurse. Investigation of computer use combined with other health service contacts would be worth while.

What is already known on this topic

Education of patients with schizophrenia has limited but positive outcomesComputer based approaches have not been thoroughly evaluated

What this study adds

A computer based method of education for patients with schizophrenia, which personalised the information with details from each patient''s medical record, was acceptable and as effective as educational sessions given by a community psychiatric nurseHowever, because of the need to provide transport for patients to attend their sessions, the computer based intervention was as costly as the nurse based oneInvestigating the addition of computer based education to other routine patient contacts would be worthwhile     

Progressive supranuclear palsy as differential diagnosis of Parkinson's disease in the elderly

IntroductionProgressive supranuclear palsy (PSP) is a syndrome characterized by progressive parkinsonism with early falls due to postural instability, typically vertical gaze supranuclear ophthalmoplegia, pseudobulbar dysfunction, neck dystonia and upper trunk rigidity as well as mild cognitive dysfunction. Progressive supranuclear palsy must be differentiated from Parkinson's disease taking into account several so-called red flags.Materials and methodsWe report a case series hallmarked by gait abnormalities, falls and bradykinesia in which Parkinson's disease was the initial diagnosis.ResultsDue to a torpid clinical course, magnetic resonance imaging (MRI) was performed demonstrating midbrain atrophy, highly suggestive of progressive supranuclear palsy.ConclusionThe neuroradiological exams (magnetic resonance imaging, single photon emission computer tomography, and positron emission tomography) can be useful for diagnosis of PSP. Treatment with levodopa should be considered, especially in patients with a more parkinsonian phenotype.     

Computer Simulation of the Film Growth Process on the Two-Dimensional Penrose Pattern

Abstract

We performed computer simulation of the film growth process on the two-dimensional (2D) Penrose pattern, which is considered a typical structural model of quasicrystal. The atomistic structure of the deposited atoms was obtained as a function of time under various conditions of atomic binding energy, temperature and deposition rate. The Monte Carlo method based upon the solid-on-solid model was utilized for the present calculation. We found a geometrical restriction on the growth front of grains in the 2D Penrose pattern, which is also expected for the growth of an actual quasicrystal.     

Computer support for determining drug dose: systematic review and meta-analysis

ObjectiveTo review the effectiveness of computer support for determining optimum drug dose.DesignSystematic review of comparative studies where computers gave advice to clinicians on the most appropriate drug dose. Search methods used were standard for the Cochrane Collaboration on Effective Professional Practice.SubjectsComparative studies conducted worldwide and published between 1966 and 1996.ResultsEighteen studies met the inclusion criteria. The drugs studied were theophylline, warfarin, heparin, aminoglycosides, nitroprusside, lignocaine, oxytocin, fentanyl, and midazolam. The computer programs used individualised pharmacokinetic models to calculate the most appropriate dose. Meta-analysis of data from 671 patients showed higher blood concentrations of drug with computer support (effect size 0.69, 95% confidence interval 0.36 to 1.02) and reduced time to achieve therapeutic control (0.44, 0.17 to 0.71). The total dose of drug used was unchanged, and there were fewer unwanted effects of treatment. Five of six studies measuring outcomes of care showed benefit from computer assistance.ConclusionsThis review suggests that using computers to determine the correct dose of certain drugs in acute hospital settings is beneficial. Computers may give doctors the confidence to use higher doses when necessary, adjusting the drug dose more accurately to individual patients. Further research is necessary to evaluate the benefits in general use.

Key messages

• This systematic review of studies examining computer support for determining optimum drug dose showed benefits from computer use
• Computer support led to patients having increased blood concentrations of drug, reduced time to achieve therapeutic benefits, and fewer unwanted effects of treatment
• Computer support helps doctors to tailor drug doses more closely to the needs of individual patients
• All the studies took place in hospitals, and further research is needed to determine the risks and benefits of widespread use of computer support, particularly in general practice, where most prescribing takes place

     

Numerical Calculation of the Bridge Function for Soft-Sphere Supercooled Fluids via Molecular Dynamics Simulations

Abstract

Isokinetic molecular dynamics simulations have been performed for 13,500 soft-spheres interacting through the inverse-power potential, ε([sgrave]/r)ⁿ , near and below the freezing temperature. The bridge function for the integral equation of the theory of liquids is extracted from the pair distribution function (PDF) obtained by the computer simulations for n = 6 and 12. The result is compared with that of approximate theories, i.e., the Rogers-Young (RY) approximation and a modified hypernetted-chain approximation for supercooled soft-sphere fluids (MHNCS approximation). Below the freezing temperature, the bridge function obtained by the computer simulation begins to oscillate around zero at intermediate distances where the second peak of the PDF appears. Such oscillatory behavior of the bridge function is well reproduced by the MHNCS approximation which includes correlations given by the leading elementary diagram, in remarkable contrast to that of the RY approximation. The present result suggests that the split second peak of the PDF for highly supercooled liquids is essentially dominated by the intermediate-distance-range correlation of the leading elementary diagram.     

Evaluation of computer based clinical decision support system and risk chart for management of hypertension in primary care: randomised controlled trial

ObjectivesTo investigate the effect of a computer based clinical decision support system and a risk chart on absolute cardiovascular risk, blood pressure, and prescribing of cardiovascular drugs in hypertensive patients.DesignCluster randomised controlled trial.Setting27 general practices in Avon.Participants614 patients aged between 60 and 79 years with high blood pressure.InterventionsPatients were randomised to computer based clinical decision support system plus cardiovascular risk chart; cardiovascular risk chart alone; or usual care.ResultsPatients in the computer based clinical decision support system and chart only groups were no more likely to have cardiovascular risk reduced to below 10% than patients receiving usual care. Patients in the computer based clinical decision support group were more likely to have a cardiovascular risk ⩾10% than chart only patients, odds ratio 2.3 (95% confidence interval 1.1 to 4.8). The chart only group had significantly lower systolic blood pressure compared with the usual care group (difference in means −4.6 mm Hg (95% confidence interval −8.4 to −0.8)). Reduction of diastolic blood pressure did not differ between the three groups. The chart only group were twice as likely to be prescribed two classes of cardiovascular drugs and over three times as likely to be prescribed three or more classes of drugs compared with the other groups.ConclusionsThe computer based clinical decision support system did not confer any benefit in absolute risk reduction or blood pressure control and requires further development and evaluation before use in clinical care can be recommended. Use of chart guidelines are associated with a potentially important reduction in systolic blood pressure.     

Aqueous Hydration of Nucleic Acid Constituents: Monte Carlo Computer Simulation Studies

Abstract

Monte Carlo computer simulations were performed on dilute aqueous solutions of thymine, cytosine, uracil, adenine, guanine, the dimethyl phosphate anion in the gauche-gauche conformation and a ribose and deoxyribose derivative. The aqueous hydration of each molecule was analysed in terms of quasi-component distribution functions based on the Proximity Criterion, and partitioned into hydrophobic, hydrophilic and ionic contributions. Color stereo views of selected hydration complexes are also presented. A preliminary discussion of the transferability of functional group coordination numbers is given. The results enable to comment on two current problems related to the hydration of nucleic acids: a) the theory of Dickerson and coworkers on the role of water in the relative stability of the A and B forms of DNA and b) the idea of water bridges and filaments emerging from the computer simulation results on the hydration of DNA fragments by Clementi.     

Machine Assisted Encoding Of Artifact Characteristics

Abstract

A computer encoding device known as a RAND Tablet can be applied in archeological researchto read off of an artifact, such as a flint projectile point, certain points of data that when used by a computer program to provide measurements from the artifact, can provide a basis for classification.     

Motor unit potentials with satellites in dystrophinopathies

IntroductionThe objective of this study was to analyze the motor unit potentials (MUPs) with satellite components i.e., delayed by at least 2 ms baseline from the main component, in the dystrophinopathies.MethodsThe parameters of the MUPs recorded from the biceps brachii muscle in the Duchenne and Becker Muscle Dystrophy (DMD, BMD) were analyzed. The origin of the MUP satellite components was studied using a computer simulation.ResultsAs compared with normal potentials, both the main and the satellite MUP components are smaller in size, while the main components are more irregular. The computer simulation allows the range of muscle fiber diameters to be determined, and suggests that the variability characterizing diameters within the motor unit is responsible for generating the delayed, satellite components, via the linear relationship between the fiber diameter and the conduction velocity of the action potential.DiscussionThe enhanced understanding of the origin of the MUP satellite components augments the knowledge about the relationship between muscle morphology and bioelectrical activity. The indirect evaluation of the range of muscle fiber diameters by means of a computer simulation may provide a new quantitative morphological data available from the EMG.     

Mutants and molecular dockings reveal that the primary L-thyroxine binding site in human serum albumin is not the one which can cause familial dysalbuminemic hyperthyroxinemia

BackgroundNatural mutations of R218 in human serum albumin (HSA) result in an increased affinity for L-thyroxine and lead to the autosomal dominant condition of familial dysalbuminemic hyperthyroxinemia.MethodsBinding was studied by equilibrium dialysis and computer modeling.ResultsTen of 32 other isoforms tested had modified high-affinity hormone binding. L-thyroxine has been reported to bind to four sites (Tr) in HSA; Tr1 and Tr4 are placed in the N-terminal and C-terminal part of the protein, respectively. Site-directed mutagenesis gave new information about all the sites.ConclusionsIt is widely assumed that Tr1 is the primary hormone site, and that this site, on a modified form, is responsible for the above syndrome, but the binding experiments with the genetic variants and displacement studies with marker ligands indicated that the primary site is Tr4. This new assignment of the high-affinity site was strongly supported by results of MM-PBSA analyses and by molecular docking performed on relaxed protein structure. However, dockings also revealed that mutating R218 for a smaller amino acid increases the affinity of Tr1 to such an extent that it can become the high-affinity site.General significancePlacing the high-affinity binding site (Tr4) and the one which can result in familial dysalbuminemic hyperthyroxinemia (Tr1) in two very different parts of HSA is not trivial, because in this way persons with and without the syndrome can have different types of interactions, and thereby complications, when given albumin-bound drugs. The molecular information is also useful when designing drugs based on L-thyroxine analogues.     

Computer vision for LCA foreground modelling—an initial pipeline and proof of concept software,lcopt-cv

Purpose

The majority of LCA studies begin with the drawing of a process flow diagram, which then needs to be translated manually into an LCA model. This study presents an initial image processing pipeline, implemented in an open-source software package, called lcopt-cv, which can be used to identify the boxes and links in a photograph of a hand-drawn process flow diagram and automatically create an LCA foreground model.

Methods

The computer vision pipeline consists of a total of 15 steps, beginning with loading the image file and conversion to greyscale. The background is equalised, then the foreground of the image is extracted from the background using thresholding. The lines are then dilated and closed to account for drawing errors. Contours in the image are detected and simplified, and rectangles (contours with four corners) are identified from the simplified contours as ‘boxes’. Links between these boxes are identified using a flood-filling technique. Heuristic processing, based on knowledge of common practice in drawing of process flow diagrams, is then performed to more accurately identify the typology of the identified boxes and the direction of the links between them.

Results and discussion

The performance of the image processing pipeline was tested on four flow diagrams of increasing difficulty: one simple computer drawn diagram and three photographs of hand-drawn diagrams (a simple diagram, a complex diagram and a diagram with merged lines). A set of default values for the variables which define the pipeline was developed through trial and error. For the two simple flow charts, all boxes and links were identified using the default settings. The complex diagram required minor tweaks to the default values to detect all boxes and links. An ‘unstacking’ heuristic allowed the diagram with merged lines to be correctly processed. After some manual reclassification of link directions and process types, the diagrams were turned into LCA models and exported to open-source LCA software packages (lcopt and Brightway) to be verified and analysed.

Conclusions

This study demonstrates that it is possible to generate a fully functional LCA model from a picture of a flow chart. This has potentially important implications not only for LCA practitioners as a whole, but in particular for the teaching of LCA. Skipping the steep learning curve required by most LCA software packages allows teachers to focus on important LCA concepts, while participants maintain the benefits of experiential learning by doing a ‘real’ LCA.

     

Oligonucleotides Containing a 6-Substituted Pyrimidine Base: A Design for Myb Inhibitors

Abstract

An oligonucleotide having a 6-formylpyrimidine nucleoside in the Myb binding sequence was synthesized based on computer calculation to fit the DNA-protein binding structure.     

Atomistic Simulation of New Materials: Pitfalls and Promises

Abstract

In this paper, we discuss some of the pitfalls that may be encountered using atomistic computer simulations of complex inorganic materials. The examples discussed are intended to illustrate the promising role that computer simulations can play in solid state chemistry, providing the pitfalls are avoided.     

Use of computer terminals on wards to access emergency test results: a retrospective audit

ObjectiveTo assess delay in clinicians obtaining emergency biochemistry test results when the telephoning of results by laboratory staff is supplanted by installation of computer ward terminals.DesignRetrospective observational study.SettingAccident and emergency department and acute medical admissions ward of a teaching hospital.Sample3228 emergency requests for biochemistry tests sent from the accident and emergency department and 1836 from the medical admissions ward during August 1999 to January 2000 when there was no recorded telephone contact for results.ResultsThe results from 1443/3228 (45%) of urgent requests from accident and emergency and 529/1836 (29%) from the admissions ward were never accessed via the ward terminal. Results from 794/3228 (25%) of accident and emergency requests and 413/1836 (22%) of admissions ward requests were seen within 1 hour of becoming available while a further 491/3228 (15%) and 341/1836 (19%) respectively were accessed between 1 and 3 hours. In up to 43/1443 (3%) of the accident and emergency test results that were never looked at the findings might have led to an immediate change in patient management.ConclusionsWhen used as the sole substitute for telephoning results, the provision of terminal access to laboratory results on wards can hinder rather than promote the communication of emergency blood results to healthcare staff.

What is already known on this topic

Providing computer terminals on wards to access laboratory results is usually regarded as a service improvement for healthcare staffMany laboratories that transmit results to ward terminals dispense with telephoning emergency blood results

What this study adds

Many urgently requested results are not looked at if hospital staff need to access a computer terminal to obtain themIf ward terminals are used as a complete substitute for the telephone, results that would have led to an immediate change in patient management may pass unnoticed     

Computer Simulation by Molecular Dynamics as a Tool for Modelling of Molecular Systems

Abstract

A survey is given of methods for simulation of molecular systems on a computer. The various assumptions, approximations and limitations are discussed and the possibility of making comparisons with experimental quantities is assessed. Finally, a number of practical applications of molecular dynamics simulation techniques in chemistry are reviewed.     

Hexagonal-String Phases in Suspension Flow

Abstract

Investigations of the structure of flowing colloidal suspensions have seen structures of predominantly hexagonal strings moving in layered arrangements in the direction of the velocity gradient. A combination of computer simulation trajectories and computer graphics show that the predominant “hexagonal string phase” is the BCC lattice sheared along its (111) slip plane and, moreover, that all the common cubic lattice types contain “hexagonal strings”.