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At least 163 records · Page 9Linked to original sources
PubMed2002

Step-by-step mark-up of medical guideline documents.

The quality of document-centric formalisation of medical guidelines can be improved using a decomposition of the whole process into several explicit steps. We present a methodology and a software tool supporting the step-by-step formalisation process. The knowledge elements can be marked up in the text with increasing level of detail, rearranged into an XML knowledge base and exported into the operational representation. Semi-automated transitions can be specified by means of rules. The approach has been tested in a hypertension application.

Czech Republic↗
PubMed2005

Conversion of one-step to two-step self-etch adhesives for improved efficacy and extended application.

PURPOSE: One-step self-etch adhesives have restricted use due to their acid-base incompatibility with autocured composites and their behavior as permeable membranes after polymerization. This study examined the feasibility of their conversion to two-step self-etch adhesives via the adjunctive use of a non-solvented, relatively hydrophobic resin coating. METHODS: iBond, Xeno III and Adper Prompt were used either in multiple coats, or in a single coat followed by the use of a layer of Scotchbond Multi-Purpose Plus bond resin for coupling to light- and auto-cured composites. Four types of experiments were performed. Bonded specimens were examined with TEM after immersion in an ammoniacal silver nitrate tracer. Fluid flow measurements of iBond were conducted using the two application protocols to compare the permeability of the bonded dentin with the original smear layer. Permeability of vital dentin bonded with both application protocols were compared for the transudation of dentin fluid across the bonded dentin. Microtensile bond strengths of dentin bonded with the two protocols were examined for their compatibility with an auto-cured composite. RESULTS: The results of the four experiments were complementary. iBond and Xeno III exhibited "apparent incompatibility" to auto-cured composites that resulted from their inherent permeability. This was confirmed by the presence of dentin fluid transudate on the adhesive surfaces when they were bonded to vital dentin. Conversely, Adper Prompt exhibited "true incompatibility" to auto-cured composites that was caused by adverse acid-base interaction, masking the inherent permeability of this adhesive. "True" and "apparent" incompatibility issues were eliminated upon their conversion to two-step self-etch adhesives.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1988

One-step chemiluminescent immunoassay of free thyroxin with acridinium-ester-labeled thyroxin evaluated and compared with a two-step radioimmunoassay.

This new one-step chemiluminescent immunoassay of free thyroxin (FT4) involving a thyroxin-immunoglobulin conjugate labeled with acridinium ester (Magic Lite System; Ciba Corning Diagnostics Corp., Medfield, MA) is rapid (one 1-h incubation), requires two calibrators per run, and takes 10 s per sample for the quantification step. Analytical performances were excellent: within- and between-run CVs of less than 10% in the working range, no significant effect of hemolysis, bilirubin, or lipemia, and no significant interaction between the conjugate and the thyroxin-binding proteins. Magic Lite results (y) correlated well with those obtained by the Sclavo (x) two-step radioimmunoassay (Sclavo, Siena, Italy): y = 1.35x + 1.32 (r = 0.94, n = 267, P less than 0.001, Sxy = 6.29). Clinical sensitivities (diagnostic efficiencies) for hypothyroidism and hyperthyroidism were 0.91 and 0.98 for normal interval limits of 12 and 21.5 pmol/L (95% confidence interval). Magic Lite results in situations where patient therapy, treatment, or unusual conditions can result in a lack of correlation between the clinical status and the FT4 values were qualitatively the same as those obtained by the Sclavo assay.

Adult↗
PubMed1981

Early steps of excision repair of cyclobutane pyrimidine dimers by the Micrococcus luteus endonuclease. A three-step incision model.

The early steps of excision repair of cyclobutane pyrimidine dimers are investigated. It is demonstrated that the apurinic/apyrimidinic endonuclease associated with the Micrococcus luteus uv-specific endonuclease cleaves the phosphodiester bond on the 3' side of the deoxyribose leaving a 3' hydroxy terminus and a 5' phosphoryl terminus. This nick is not a substrate for T4 polynucleotide ligase. The 3' base-free deoxyribose terminus is not a substrate for either the polymerase or the 3' to 5' exonuclease activities of Escherichia coli DNA polymerase I. However, the 3' terminus of the nick is converted to a substrate for DNA polymerization by the action of a 5' apurinic/apyrimidinic endonuclease. A three-step model for the incision step of excision repair of cyclobutane pyrimidine dimers is presented.

Alkaline Phosphatase↗
PubMed1996

[Company Wide Quality Control (total quality): methodological principles and intervention techniques for step-by-step improvement].

The concept of Quality is particularly up to date and not a new one for the Journal. The need for better Quality is a must also in Medical care. Quality doesn't mean additional costs and excessive burden for the co-workers. On the contrary, initial costs can be compensated for through a more rational utilisation of the resources. The consequent better service for the patient results in an ameliorated working environment, with high profits. Fundamental requirements for reaching concrete results are: 1) the convinced involvement in the idea of all levels (division, service, laboratory) in order to have the different groups act in synergism towards common goals; 2) the knowledge of appropriate methods. The Authors examine this last point with a deep analysis of the techniques involved in Company Wide Quality Control (C.W.Q.C.) or Total Quality. The improving process has to the continuous and proceed in small steps, each time being constituted by 4 different phases, represented by the PDCA cycle, or Demining wheel, where: P = PLAN, which means plan before acting; D = DO, perform what has been planned; C = CHECK, verify the results; A = ACT, standardize if the results are positive, repeat the process if negative. Each process of improvement implies a prior precise definition of a project, i.e. a problem whose solution has been planned. The project must always presume: a specific subject--a goal--one or more people to reach it--a limited time to work it out. The most effective way to ameliorate Quality is performing projects. Step by Step amelioration is synonymous of performance of many projects. A brilliant way to produce many projects remains their "industrialization", which can be reached by means of 6 basic criteria: 1) full involvement of the Direction; 2) potential co-working in the projects of all employees; 3) employment of simple instruments; 4) respect of a few procedural formalities; 5) rewarding of personnel; 6) continuous promotion of the concepts of quality and ongoing improvement. The Authors describe for each of the previous criteria approaching methods and best operative techniques, according C.W.Q.C.

Humans↗
PubMed1996

Bond strength of multi-step and simplified-step systems.

PURPOSE: To measure and compare the in vitro shear bond strength (SBS) of the following three pairs of multi- and simplified-step dentin bonding systems: OptiBond vs. OptiBond FL, All-Bond 2 vs. One-Step, and Tenure vs. Tenure Quik. MATERIALS AND METHODS: 60 extracted human mandibular molars were sectioned perpendicular to the long axis 1 mm above the CEJ to expose the dentin bonding surface. After being wet-ground to 600 grit with SiC abrasive papers, rinsed and dried, the teeth were individually mounted in phenolic rings with epoxy resin, and randomly assigned into six equal groups of 10 each. The dentin surfaces were treated with the above mentioned dentin bonding systems, and a gelatin cylinder filled with resin composite (Pertac-Hybrid) was directly bonded to each pretreated surface. After 7-day storage in 37 degrees C water followed by thermocycling, the specimens were shear tested to failure on an Instron machine. Data were analyzed by independent t-tests, one-way ANOVA, and Duncan's Multiple Comparison tests at alpha = 0.05. RESULTS: Except for the pair Tenure/Tenure Quik, the differences between the pairs All-Bond 2/One-Step and OptiBond/OptiBond FL were statistically significant with All-Bond 2 and OptiBond FL yielding higher shear bond strength (P < 0.05). Findings of this study indicated that OptiBond FL was the only simplified-step system showing improved bond strength.

Analysis of Variance↗
PubMed1977

[Residue situation of milk products after the effective carrying out of the "step-by-step program for DDT-replacement" in the GDR].

A step-by-step program had been established to replace the persistent insecticide DDT with other active principles in the GDR by 1975. Monthly thin-layer chromatographic residue determinations in butter samples from all the districts demonstrate that the DDT-residues have decreased gradually since 1973 from an average value of 0.45 mg/kg to an average value of 0.18 mg/kg (in 1976). The DDT intake of adults via the milk products (butter, milk and cheese) was, in 1976, only 2% of the ADI value, which evidences a very positive development. Furthermore, findings concerning the contamination with lindane and HCB are presented.

Animals↗
PubMed1977

A comparison between the one-step and the two-step copper thiocholine procedure for the cytochemical localization of cholinesterases.

A comparison between the one-step and the two step copper thiocholine procedure for the subcellular localization of cholinesterases was undertaken. The results indicate that only under experimental conditions with short incubation times and precise control of the conversion into sulphide is the localization of the primary precipitate and that of the secondary precipitate identical. It was concluded that the conversion of the primary precipitate into Cu-sulphide is not necessary and can lead to artefacts.

Animals↗
PubMed1994

Recombinant human insulin. III. High-performance liquid chromatography and high-performance capillary electrophoresis control in the analysis of step-by-step production of recombinant human insulin.

The production of recombinant human insulin consists of five main stages, accompanied by considerable transformation of molecules, concerning size, secondary structure and the presence of charged groups. The application of different methods, i.e., size-exclusion, ion-exchange and reversed-phase high-performance liquid chromatography (HPLC) and high-performance capillary electrophoresis (HPCE) (capillary zone electrophoresis and micellar electrokinetic capillary chromatography), to the analysis of insulin, insulin-related and non-insulin-related substances was studied. A combined HPLC-HPCE system for the step-by-step control of recombinant human insulin production technology is suggested. The advantages and shortcomings of these methods are discussed.

Amino Acid Sequence↗
PubMed2006

To step or not to step? How biochemistry and mechanics influence processivity in Kinesin and Eg5.

Conventional kinesin and Eg5 are essential nanoscale motor proteins. Single-molecule and presteady-state kinetic experiments indicate that both motors use similar strategies to generate movement along microtubules, despite having distinctly different in vivo functions. Single molecules of kinesin, a long-distance cargo transporter, are highly processive, binding the microtubule and taking 100 or more sequential steps at velocities of up to 700 nm/s before dissociating, whereas Eg5, a motor active in mitotic spindle assembly, is also processive, but takes fewer steps at a slower rate. By dissecting the structural, biochemical and mechanical features of these proteins, we hope to learn how kinesin and Eg5 are optimized for their specific biological tasks, while gaining insight into how biochemical energy is converted into mechanical work.

Animals↗
PubMed2004

Strain rate and strain: a step-by-step approach to image and data acquisition.

The advent of strain and strain rate imaging in clinical echocardiography prompted an examination of proper techniques for image acquisition and analysis. For this promising and relatively new method of assessing myocardial performance to be successful in diagnostic echocardiography, close adherence to a standardized method is imperative. This article provides the echocardiographer with a step-by-step approach.

Algorithms↗
PubMed2005

An overview to CERSSO's self evaluation of the cost-benefit on the investment in occupational safety and health in the textile factories: "a step by step methodology".

INTRODUCTION: The Pan American Health Organization (PAHO) and CERSSO collaborated to develop a new Tool Kit (TK), which became available in May 2002. PAHO already had a TK in place, and CERSSO requested that one be developed for their needs. CERSSO wanted to enable managers and line workers in garment factories to self-diagnose plant and workstation hazards and to estimate the costs and benefits of investing in occupational safety and health (OSH) as a way to improve productivity and competitiveness. METHODS: For consistency, the collaborating organizations agreed to construct the TK according to PAHO's methodology. The instrument was developed to be comprehensive enough that any user can collect the data easily. It integrates epidemiologic, risk assessment, clinic, engineering, and accountability issues, organized to include step-by-step training in: (a) performing risk assessments in the workplaces (risk factors); (b) making cause-effect relationships; (c) improving decision making on OSH interventions; (d) doing calculations of direct and indirect costs and savings; and (e) doing calculation of the overall cost-benefit of OSH interventions. RESULTS AND CONCLUSIONS: Since July 2002, about 2,400 employees and officials from 736 garment factories, Ministries of Labor, Health, Social Security Institutes, and Technical Training Institutions of Central America and the Dominican Republic have used this instrument. Systematically, they have calculated a positive relationship of the investment (3 to 33 times). Employers are now aware of the financial rewards of investing in OSH. The TK is available in Spanish, Korean, and English. In July 2003, a software program in Spanish and English was developed (180 persons have been trained in the region), which requires less time to execute with better reliability.

Central America↗
PubMed2003

Step by step removal of hyperforin and hypericin: activity profile of different Hypericum preparations in behavioral models.

Herbal extracts of Hypericum perforatum L. (St. John's wort, SJW) are now successfully competing for status as a standard antidepressant therapy. Because of this, great effort has been devoted to identifying the antidepressive active compounds. In the present study we used the following strategy to evaluate the relative pharmacological importance of various extract components: 1. preparation of an hydroalcoholic SJW extract containing both hyperforin (3.2%) and hypericin (0.15%) (extract A); 2. step by step removal of hyperforin and hypericin led to the following extracts: Extract B, devoid of hyperforin but still containing hypericin (0.14%) and Extract C, free of hypericin and hyperforin but enriched in flavonoids ( approximately 12%). We characterized the in vivo activity profile of all three preparations using the tail suspension test (TST) in mice and the forced swimming test (FST) in rats as screening models. We further investigated the activity of pure hyperforin. Extract B and C (500 mg/kg each) as well as pure hyperforin (8 mg/kg) significantly shortened immobility time in the TST after acute pre-treatment whereas extract A was inactive. In the FST all three extracts decreased immobility time in a dosage of 500 mg/kg after acute as well as after repeated treatment. The present results clearly show that an SJW extract free of hyperforin and hypericin exerts antidepressant activity in behavioral models, supporting our working hypothesis that flavonoids are part of the constituents responsible for the therapeutic efficacy of SJW extracts. We also could show that hyperforin contributes to the beneficial properties of SJW extract, confirming the hypothesis that the crude SJW extract contains several constituents with antidepressant activity.

Administration, Oral↗
PubMed2001

Kinetic model discrimination via step-by-step experimental and computational procedure in the enzymatic oxidation of D-glucose.

The enzymatic oxidation of D-glucose to 2-keto-D-glucose (D-arabino-hexos-2-ulose, D-glucosone) is of prospective industrial interest. Pyranose oxidase (POx) from Peniphora gigantea is deactivated during the reaction. To develop a kinetic model including the main reaction and the enzyme inactivation, possible side-reactions of the non-stabilised enzyme with D-glucosone, hydrogen peroxide, and peroxide radicals were considered. A developed step-by-step combined experimental and computational procedure allowed to discriminate among alternative inactivation mechanisms and provides an increased model reliability. The most probable scheme is the enzyme inactivation by hydroxyl radicals formed from produced H2O2 in the presence of Fe2+ ions. This .OH reaction is supported by matrix assisted laser desorption ionisation-mass spectrometry (MALDI-MS) measurement. The estimated kinetic parameter values for the main reaction are of the same order of magnitude as those reported in the literature. The identified model allows a satisfactory process simulation and highlights measures to prevent the enzyme activity loss.

Bioreactors↗
PubMed2001

A step-by-step guide to non-linear regression analysis of experimental data using a Microsoft Excel spreadsheet.

The objective of this present study was to introduce a simple, easily understood method for carrying out non-linear regression analysis based on user input functions. While it is relatively straightforward to fit data with simple functions such as linear or logarithmic functions, fitting data with more complicated non-linear functions is more difficult. Commercial specialist programmes are available that will carry out this analysis, but these programmes are expensive and are not intuitive to learn. An alternative method described here is to use the SOLVER function of the ubiquitous spreadsheet programme Microsoft Excel, which employs an iterative least squares fitting routine to produce the optimal goodness of fit between data and function. The intent of this paper is to lead the reader through an easily understood step-by-step guide to implementing this method, which can be applied to any function in the form y=f(x), and is well suited to fast, reliable analysis of data in all fields of biology.

Computational Biology↗
PubMed2003

Laparoscopic radical cystoprostatectomy: a technique illustrated step by step.

OBJECTIVES: Laparoscopic surgery is expanding among urologists as a minimally invasive treatment and may now be applied to treat neoplasms of the pelvic organs. Laparoscopic cystoprostatectomy has still not been well codified and illustrated. We describe a technique of laparoscopic radical cystoprostatectomy that we have developed in 10 patients after practicing in laparoscopic radical prostatectomy. METHODS: Between June 2001 and July 2002, 10 men with bladder cancer underwent laparoscopic cystoprostatectomy with urinary diversion. This report details step by step our 5-port transperitoneal technique with primary access to the seminal vesicles and Denonvillier's fascia, ureters detection after umbilical arteries incision, endopelvic fascia incision and dorsal vein complex control before division of the vesical and prostatic fibrovascular pedicles with a harmonic scalpel. RESULTS: We performed 6 orthotopic ileal neobladders, 2 sigmoid ureterostomies and 2 cutaneous ureterostomies. In all cases no conversion to open surgery was necessary. The mean time to perform the laparoscopic radical cystoprostatectomy, including the lymph node dissection, was 166 minutes (range 150-180). Mean estimated blood loss was 310 ml (range 220-440). Mean hospital stay was 8.1 days (range 7-9) for ileal orthotopic neobladder, 8 days (range 7-9) for sigmoid ureterostomy and 5 days for cutaneous ureterostomy. The mean follow up is 12.3 months (range 5-18). Two patients respectively with stage T2bN0 G2-3 and stage pT1N0 (plus carcinoma in situ) G3 transitional cell carcinoma and surgical margins tumor free had diffusive metastatic disease after 6 months. The other 8 patients are free from disease. CONCLUSIONS: Laparoscopic radical cystectomy is still an operation for pioneers but this procedure may be not strictly relegated to a few academic centers. In our opinion laparoscopic cystoprostatectomy is a feasible, fast, safe and easy procedure and urinary diversion may be performed with a laparoscopic, open or combined approach without reducing the advantages of laparoscopy.

Aged↗